, 蒙吉军, 彭建北京大学城市与环境学院 地表过程分析与模拟教育部重点实验室,北京 100871
Recent research progress at Peking University and contributions to integrated physical geography
LIShuangcheng, MENGJijun, PENGJian收稿日期:2017-10-17
修回日期:2017-11-2
网络出版日期:2017-11-20
版权声明:2017《地理学报》编辑部本文是开放获取期刊文献，在以下情况下可以自由使用：学术研究、学术交流、科研教学等，但不允许用于商业目的.
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1 引言
纵观自然地理学的发展历史,分支学科的专门化和综合集成过程交织进行。20世纪,随着研究手段、观测和实验技术的不断发展,在以分析思维为主的还原论思潮影响下,自然地理学内部各个分支如地貌学、气候学、水文地理学、土壤地理学、生物地理学等都形成了比较系统的独立理论和学科研究范式。这种趋势一方面促进了自然地理学研究的深入,另一方面又使其内部产生了深刻的学科分化,呈现出空心化现象[1]。这种空心化的倾向对包括自然地理学在内的地理学发展产生了负面影响,引起了国内外地理学家的广泛关注[2-4]。然而,随着自然地理学系统研究范式的逐步确立[5],在全球各个尺度资源环境问题和社会经济发展需求刺激下,在国际重大科学研究计划如“未来地球”推动下,自然地理学的综合研究重新成为学界关注的热点。综合自然地理学（Integrated physical geography）研究自然地理环境各组成要素间的物质能量关系,阐明自然地理环境的历史形成、现代过程、类型结构、地域分异和发展演变,是自然地理学的重要组成部分。从要素综合、过程综合逐渐提升到区域综合水平[6],综合自然地理学进入一个新的发展阶段。目前,综合自然地理学的前沿研究领域包括：① 全球环境变化的影响与人类响应。在已有要素和过程综合的基础上,探索地球系统各组成部分之间复杂的社会—环境相互作用的耦合机理,寻求在局地、区域和全球尺度上缓解人地紧张关系的解决方案和转型方式[7];② 陆地表层过程与格局的综合研究。重点研究陆地表层过程与格局变化的成因机理、幅度与速率、影响与适应,辨识变化的自然与人文驱动因素,模拟变化的动态趋势,评估变化趋势的可控、可缓及其程度[1, 6];③ 特殊区域的综合研究。重点关注一些更容易受到全球环境变化与人类活动影响的区域科学问题,如干旱半干旱区的水分循环和水资源形成、山地自然—人文环境和灾害相互作用、极地（包括青藏高原）冰冻圈环境变化及其对全球气候的影响、海岸带与岛屿灾害及其可持续发展等[7]。
北京大学作为近现代中国地理学开创和发展的学术大本营,半个多世纪以来对中国自然地理学尤其是综合自然地理学发展都起到了重要的引领和推动作用。回顾发展历程、梳理学术贡献、展望发展趋势,无疑对新时期中国乃至国际综合自然地理学的发展都大有裨益。
2 发展历程
北京大学自然地理学专业的渊源可追溯到1929年建立的清华大学地学系地理组,以及抗战期间的西南联大地质地理气象系地理组。1952年全国院系调整,清华大学地学系地理组和燕京大学部分教员联合成立北京大学地质地理系时首先设立了自然地理专业,从清华大学转入北京大学的林超和李孝芳是自然地理专业的主要奠基人。随着地貌、植物地理、环境地理的相继专门化,北京大学自然地理专业形成了以自然地理综合研究为鲜明特色的研究体系。林超、李孝芳、陈传康、范信平、李寿深、关伯仁、卢培元等老一辈****在自然地理综合研究和教学中发挥了重要作用。随着20世纪50年代末期苏联****A. R. 伊萨钦科来中国系统讲授地理壳、自然区划和景观学进展,该讲学研修班在林超领导下经集体讨论,确定了“综合自然地理学”的学科名称,并发展为自然地理学的一门独立分科[8]。1978年、1982年和1988年,林超陆续招收（综合）自然地理专业的硕士生、博士生和博士后,并于1978年开设了“土地类型和自然区划国内外研究动态”研究生课程,系统介绍英、澳、美、加、德、荷等国家或学派的土地系统、自然分区等理论研究和实践成果,对推动中国综合自然地理学理论发展和人才培养做出了重要贡献[9]。在综合自然区划方面,林超、冯绳武和关伯仁于1954年率先完成了《中国自然地理区划大纲》,是新中国第一个完备的全国综合自然地理区划方案,比之前的历次区划跨进了一大步,基本反映了全国的自然地理面貌[10]。依据区划学和类型学相结合的方法,陈传康建立了全球性分异、大陆大洋地域分异、区域性分异、中尺度分异和地方性分异的地球表层地域分异规律体系,对自然区划的原则和方法进行了开拓性研究[8],提出了以双列系统分析为基础的综合单列系统,成为以后开展自然区划研究的理论基础。在土地类型学研究中,陈传康提出了以地貌部位及其结构为基础的土地分级划分标准[11]。20世纪70年代后期,中国大、中比例尺土地类型制图中的土地分级遂趋向于采用景观学派和英澳学派相结合的三级分级系统,陈传康和蔡运龙等提出了一套汉语涵义较切合定义的名称——地块、地段、地方三级系统,更加方便推广应用[12]。
在科学研究的同时,还十分重视教材编写工作。1983年,陈传康和李昌文在多年教学和科研实践的基础上,汲取了英、澳学派的观点和区域实践成果,进一步完善了《综合自然地理学》讲义,同时还编纂了《综合自然地理学参考资料》（共6册）。1993年,由陈传康、伍光和、李昌文等编著的《综合自然地理学》教材在高等教育出版社正式出版[13],建立了以地域分异、自然区划、土地类型为基本理论的综合自然地理学内容体系。该教材对北京大学自然地理专业多年来的研究成果进行了总结,不仅从理论体系上对综合自然地理学进行了系统地、深层次梳理,而且从实践上进行可操作性论证,是理论、实践与方法融为一体的教科书（该教材于1995年获国家教委优秀教材二等奖）。伍光和、蔡运龙在此基础上进行了补充完善,于2004年由高等教育出版社再版了《综合自然地理学》（第二版）[14]。
3 学术贡献
全球及各个尺度的环境变化和资源生态问题的日益凸显,给综合自然地理学研究带来了巨大的机遇与挑战。北京大学综合自然地理研究紧跟国际前沿,注重实践应用,不断创新与拓展自然地理综合研究的领域。蔡运龙、王仰麟、许学工、陆雅海和李双成等****相继主持了一系列国家自然科学基金重点项目,如“西南喀斯特山区土地利用/土地覆被变化及其对土地资源利用可持续性的影响”（2004-2007）、“城市景观格局演变及其生态环境效应研究”（2007-2011）、“渤海西部海岸高强度开发的环境变化影响与多功能持续发展”（2009-2012）、“水稻土甲烷氧化的微生物机理与关键调控因子”（2012-2016）、“生态系统服务与区域社会福祉耦合机制研究：基于地理学综合分析的途径”（2012-2016）、“城市景观格局与自然灾害生态风险研究”（2014-2018）等。以重大科学研究项目为支撑,将综合自然地理研究从传统的自然地域系统研究向陆地表层过程及机理、土地利用变化及生态环境效应、景观生态风险与安全、生态系统服务等学科前沿领域延伸。3.1 陆地表层过程及机理
北京大学综合自然地理研究重点关注水、土、气、生等自然要素和过程的集成和交叉,并考虑人类活动的影响,在多尺度下对多要素进行了综合分析和模拟预测。在植物物候时空过程方面,陈效逑等从自然地理学格局与过程视角开展研究,取得了丰硕成果：① 揭示物候现象发生的顺序相关律、准年周期律和超年波动律,深化了对物候现象发生时间的基本规律及其环境机制的认识[15];② 提出物候—遥感法,实现了由点及面确定区域植被生长季节及其对气候变化的响应[16];③ 建立了一系列基于气温和降水的物候时间模型和空间模型,提高了草本和木本植物物候模拟精度并揭示了气候变化响应的区域差异及其成因[17-22]。
在气候过程研究方面,赵昕奕等长期关注下垫面气候变化及其环境效应,在气候要素时空特征、变化趋势以及人类活动影响等研究领域取得较大进展：① 分析了中国和区域气温和降水的时间变化特征[23-26];② 探讨了气候变化与土地利用类型的关系[27-29];③ 研究了人类活动对大气边界层尤其是城镇地区热环境的影响[30-32]。
在古环境和气候变化过程研究方面,王红亚等综合使用地磁学、地球化学、古生物学和测年技术等手段,利用湖泊沉积物和现代气候、水文数据,估算了华北平原的古年径流深[33],重建了内蒙古高原更新世末期和全新世[34-35]、非洲西部Sahel地区全新世[36]、中国中东部高海拔地区中、晚全新世的气候—环境变化[37-38],深化了对这些地区古气候—环境变化的认识。
在地球化学元素循环过程研究方面,周丰等阐明了水热条件对氮排放因子空间格局的影响及其地带性规律,解决了从站点到区域/全球氮排放过程的尺度转换问题[39-41];建立了“自下而上”和“自上而下”多模型集合方法[42],揭示了中国农田N2O排放增速变缓的人为驱动机制[43];开发了自适应移动网格的水生态模型[44-45]和快速源解析方法[46-47],发现了氮沉降对湖泊生态退化的“急性激发”效应和对生态恢复的“慢性推迟”效应[48]。围绕稻田土壤碳循环和甲烷排放过程,陆雅海等从事土壤微生物与生物地球化学机制研究,揭示了稻田土壤有机质厌氧分解的微生物机制[49],发现了稻田甲烷产生的关键微生物及其对土壤条件的适应机制[50],系统研究了稻田甲烷氧化过程及其调控因子,指出了稻田干湿交替和氮肥施用对甲烷氧化的促进作用[51]。
随着学术界对全球变化问题的日益关注,陆地表层过程与机理研究逐渐从区域尺度转向全球尺度,并强调不同空间尺度上多种自然过程的相互作用研究[52]。赵昕奕等研究发现近年来中国的气温变化与全球气候变化有一定程度的相关关系[53]。朴世龙等研究了温度变化对植被生长、生态系统碳源汇和农作物产量的影响及其机制,并预测了全球碳循环长期动态[54-56]。彭书时等综合评估了土地利用变化对气候的反馈作用,揭示了植被生长对气候的影响机制[57-58]。李双成等利用MODIS地表温度数据,基于卫星观测资料研究了森林生态系统对地表温度的影响,并揭示了其生物物理机制的作用[59]。
地球系统模式是研究地球表层过程和机理的重要途径,也是自然地理综合研究的必备手段。针对陆面模式薄弱或缺失诸如土地利用、植被动态、碳水耦合、湿地动态、喀斯特湖动态、甲烷排放和冻土消融等地表过程,彭书时等在陆面模式ORCHIDEE中开发和改进了相应模块,并应用于全球变化研究[60-63]。
3.2 土地利用变化及其生态环境效应
北京大学综合自然地理研究高度关注土地利用变化及其效应。蔡运龙等在梳理喀斯特地区土地利用研究现状的基础上[64],分析了贵州喀斯特地区的土地利用变化及其生态效应[65-66],提出一个土地系统变化空间尺度综合的研究方案[67],并建立了一个土地变化科学范式与生态脆弱区研究案例相结合、土地变化生态效应评价与土地利用优化配置相结合、微观过程与宏观格局相结合、退化土地修复的社会经济途径与工程技术途径相结合的土地变化综合研究体系[68]。王红亚等通过对贵州高原一些缺乏水文资料地区水库泥沙的137Cs比活度分析、粒度分析、TOC和TN分析、矿物磁性测试等,推衍20世纪60年以来降水、土地利用变化对土壤侵蚀过程的影响[69-70]。蒙吉军等在明晰河西走廊等地土地利用变化时空格局的基础上,重点研究了变化的驱动机制[71-72],提出了驱动类型对土地系统变化产生不同的影响[73],指出土地利用变化的驱动力存在明显的尺度依赖性[74]。彭建等重点关注滇西北地区土地利用演变格局[75],并在此基础上分析了退耕还林等生态工程的生态效应[76]。杨小柳等重点关注了土地利用/覆被变化对区域洪水的影响,构建“土地利用—水文—水动力耦合模型”[77-78],并在流域尺度上发展了“土地利用—水资源—生态联合调度优化模型”等一系列水资源综合管理方法[79-81]。许学工等多尺度研究黄河三角洲土地利用与土地覆被的质量变化[82];遥感监测37年渤海湾沿岸土地变化,计算了渤海湾填海造陆导致的生态损失,并提出有序填海的调控思路和方法[83-85]。这些研究厘清了不同生态脆弱区的土地演变机制,为生态脆弱区的生态保护和重建等提供借鉴。在关注过去和现状土地利用及其生态效应的同时,高度关注未来土地利用的模拟。蒙吉军等探索建立了土地系统变化情景模拟的不同方法[86],利用基于邻域相关构建空间权重的Auto-logistic模型构建CLUE-S模型,模拟了漓江流域2020年土地利用格局[87];李双成等应用基于径向基函数神经网络的CA模型,模拟了深圳市的土地利用变化情景[88]。总体而言,通过变化监测、驱动力识别、模型模拟、效应评估与预测分析等途径,重点关注土地利用时空格局变化、驱动机制、生态效应及其重要阈值,极大地推动了中国土地利用/覆被变化（LUCC）研究的发展。
随着城市化的快速发展,城市地区的土地利用变化及其生态环境效应受到高度关注。王仰麟等较早关注城市景观格局的形成机制,在关键景观格局指标析取的基础上[89],明晰了深圳市不透水表面指数等景观组分的多时相时空特征[90-91],揭示了植被变化规律及其对大城市人类活动的响应规律[92-93];同时,通过构建社会—生态系统脆弱性、恢复力、适应性等研究框架,评估景观生态风险及适应方式[94-95]。赵淑清等利用多源遥感数据完成了过去30年中国主要城市扩张时间序列图,解析了城市扩张过程的时空格局,评估了城市扩张的多种生态后果。她的研究小组发现,1978-2010年中国主要城市扩张速度和模式具有明显的时间和空间差异[96-97];城市化带来了明显的热岛效应,但强度具有季节和昼夜差异[98-99],并在方法论上探讨了使用数据的实时性对热岛效应正确评估的重要性,指出过期的边界会给热岛强度的正确评估带来误差[100];首次建立了用遥感数据评估城市化对植被生长的直接和间接影响的理论体系、定量方法,并发现城市环境对植被生长的普遍促进作用,城市化往往导致植被生长起始期提前、结束期推迟、生长季延长[101],这种间接促进作用大约可以抵消40%的城市化对于植被替代的直接负面影响[102]。彭建等梳理了城市发展的生态用地需求测算研究进展[103],基于偏相关分析明晰气候变化背景下植被对城市化进程响应机制[104],提出了城市化进程净初级生产力（NPP）响应的互不干扰、拮抗对立与协同共生三阶段概念模型[105];定量解析景观组分对地表温度的影响,明晰了区域绿地显著降温的规模阈值[106];遥感识别了中国PM2.5变化趋势,评价了其人群健康风险并划分控制区[107]。许学工等研究了北京市绿色空间的变化,强调发挥绿色空间的复合功能,进行首都圈绿色空间格局的构建[108-109]。这些研究对于科学理解城市地区土地利用变化与生态过程互馈机理、提升城市生态可持续性具有重要意义。
3.3 生态系统服务与人类福祉
生态系统服务的研究涉及不同时空尺度自然过程、自然—人文过程和人文过程及其递进关系[110],关注时空异质性、空间流动性和区域特征,能够拓展综合自然地理学的研究视角,也是综合自然地理学的最新综合途径[111]。北京大学综合自然地理****极力推动生态系统服务研究的“地理化”转向。李双成等倡议建立生态系统服务地理学范式,在系统梳理生态系统服务地理学学科框架的基础上,提出了基于地理学视角的生态系统服务分类体系、形成机制及其相互作用关系、供给与需求时空特征和区域差异、生态系统服务与人类社会福祉耦合关系等重要研究议题[112]。蒙吉军等在定量识别生态系统服务空间分异的基础上,关注土地利用对生态系统服务的影响,探讨基于生态系统服务的生态系统管理[113-114]。彭建等关注快速城市化过程对生态系统服务变化的影响,识别了人口城市化和经济城市化对生态系统服务的影响阈值[115]。李双成和彭建均对生态系统服务权衡的研究进展进行了系统梳理[110, 116],对水生态系统服务的空间流动进行了模拟[117]。同时,随着研究尺度从生态系统向景观演进,景观多功能性的研究逐渐受到关注。彭建等在对国内外多功能景观研究进行系统梳理的基础上[118],重点评估了都市区农业景观多功能性[119],并分析了耕地多功能景观的动态变化及其影响机制[120]。总体而言,生态系统服务研究极大地拓展了综合自然地理学的研究领域,成为一个新的学科增长点。
3.4 生态风险评价与安全格局构建
作为综合自然地理的重要应用出口,生态风险及其相关研究有利于更有效地应对生态风险、保障生态安全,从而促进区域可持续发展。2000年代初,许学工等最早开始探讨区域生态风险及其评价的特点,并梳理出“风险源分析—受体分析—暴露危害分析—风险表征”的区域生态风险评价概念模型[121]。蒙吉军等构建了区域生态风险评价的“3R模型”及区域生态风险防范的基本框架[122-123]。基于这些模型和框架,许学工、王仰麟、蒙吉军、彭建、赵昕奕等相继开展了城市、湿地、流域、山地、矿区、农牧交错带等不同类型区域/景观生态风险评价,进一步推动了国内的生态风险评价研究[123-128]。与此同时,彭建等在系统梳理景观生态风险研究进展的基础上[129],开始关注生态系统健康评价,寻求从风险的反面视角解析区域生态环境问题[130-131]。杨小柳等提出基于土地利用的流域水安全评估框架[132]。随着研究的不断深入,生态风险/安全的研究逐渐从关注风险/安全的空间格局认知到强调空间规避,即生态安全格局的构建。蒙吉军等基于最小累积阻力模型与多目标线性规划模型分别构建了鄂尔多斯土地利用生态安全格局,并利用景观指数对两者进行评价,从而有效指导鄂尔多斯市土地资源的可持续利用[133-134]。彭建等则系统整合提出“源地确定—廊道识别—战略点设置”的生态安全格局构建范 式[135],指出了源地识别的过程中需要考虑景观连通性、供给与需求[136],阻力面的设定应关注夜间灯光、地质灾害敏感性修正等方面的问题[137-138],提出了重要阈值设定、有效性评价、多尺度关联和生态过程耦合等四个生态安全格局构建研究的重点方向[135]。
3.5 自然地域系统划分
作为地理学的传统工作和重要研究内容,区划能够从区域角度观察和研究地域综合体,探讨区域单元的形成发展、分异组合、划分合并和相互联系,是对过程和类型综合研究的概括和总结[139]。基于前人丰富的研究成果,蔡运龙在《中国地理多样性与可持续发展》一书中阐述了三大地带和七大地区及其内部的地理多样性,可视为综合区划之集成[140]。许学工等综合考虑农业资源、农业发展、环境和生态、农村社会、科教和管理5大系统、95个指标,通过计算相对优势,进行中国农业可持续发展区划[141]。同时,李双成、蒙吉军、彭建等在综合自然区划、生态地理区划、生态功能区划、主体功能区划、生态系统服务分区等方面做了大量工作,并将快速发展的计算机技术和地理数学方法引入分区工作,有效提高了分区的客观性和科学性[142-147]。李双成等将SOFM神经网络应用于综合自然区划研究中,指出基于SOFM网络的分区具有划分层次明显、区域分割清晰、客观性强等优点,是对传统区划方法的有力补充和拓展[142];同时,将空间小波变换应用于生态地理界线识别与定位,解决了传统区划研究中分区界线难以多尺度、准确表达的问题[148]。彭建等将Kohonen神经网络应用于土地资源综合分区,采用自上而下演绎与自下而上归并相结合的途径将全国划分为41个土地资源亚区[149]。在强化技术方法的同时,分区方案的对比验证也逐渐受到关注,从而减少分区结果的不确定性。不同分区方案间的对比以及与区域自然地理特征的空间对比被普遍应用于分区结果的验证。李双成等用黄秉维综合自然区划方案中半湿润半干旱分界线作为检验标准,检验了小波分析结果的可靠性和有效性[148]。彭建等依循植被动态一致性准则,依据两步筛选法,实现了黄土高原生态地理分区多种方案间的优选[143]。此外,景观指数也被逐渐引入分区方案的验证。彭建等根据分区中的区域共轭性原则,提出基于景观聚集度指数的分区方案优选方法[150-151]。分区方法的创新和分区结果的验证,能够确保地域划分的客观性、科学性,从而有效指导区域的分区管治和可持续发展。
4 研究成果应用
北京大学综合自然地理学研究具有服务国家和社会需求的优良传统、延续至今。陈传康曾指出：综合地理学具有三重性,即要同时开展理论地理学、建设地理学和区域开发研究[152]。20世纪80年代-20世纪末,随着综合自然地理学理论体系的建立,结合区域人口、资源、环境和发展问题,北京大学综合自然地理学在实践应用方面进行了大量探索。除了参加传统的自然资源考察、应用性自然区划外,还广泛参与国土整治、区域开发与发展战略、旅游规划等应用性课题研究,为各级政府制定社会经济发展政策提供了强有力的科学支撑。进入21世纪以来,全球气候变化和资源环境问题更加凸显,北京大学综合自然地理学研究成果社会化应用指向更为突出。例如,彭书时使用改进和耦合开发新模块的ORCHIDEE为全球碳计划碳收支平衡年度报告等多个国际模型比较项目提供模拟和分析结果[153-155];他目前担任全球碳计划甲烷工作组成员,负责全球碳计划甲烷收支平衡研究中ORCHIDEE模型模拟工作,并参与完成了全球甲烷收支平衡的综合分析和全球湿地2000-2012年甲烷排放模型比较分析两个项目[156],同时完成了中国过去30年来甲烷人为排放清单,修正了EDGAR排放数据库对中国甲烷排放量的高估[157]。周丰等利用地面观测和调查资料数据,集成陆面模式、大气反演和数值模拟等多种方法,研究了氮素排放和驱动机制,研究成果被联合国发起的“全球气候智能型农业联盟”建议为精准施肥实施效果的度量工具[40],同时修正了国际社会关于“中国贡献”的认识;他目前担任全球碳计划氧化亚氮工作组成员,负责全球碳计划氧化亚氮收支平衡研究中1901-2014年农田排放模拟工作和多模型比较分析。
在服务国家需求方面,蔡运龙提出的“最小人均耕地面积”和“耕地压力指数”以及耕地价值重建理念在中国耕地资源保护方面起到了重要作用[158-159]。杨小柳等提出的三段九步法已应用于国家节水战略的编制,并将中国的流域综合管理经验介绍到国外[160];他曾任荷兰政府/全球水资源合作组织联合专家组组长,指导斯威士兰、喀麦隆、贝宁等国的国家水资源发展计划的编制,并兼任亚洲开发银行高级专家,参与亚洲—太平洋地区40余国家/地区的水安全评估。
5 重点发展方向
根据学科发展趋势和国际研究前沿,结合自身优势和特点,北京大学综合自然地理学在未来的研究中将注重以下五个方面的发展：（1）全球环境变化的区域响应及适应。通过地表过程和格局的动态模拟,探讨全球环境变化对自然生态系统和社会经济系统的影响及其交互作用,识别关键控制要素、重点响应地域,为中国气候变化适应策略的制定提供科学支撑。
（2）自然地理过程耦合及资源环境效应。持续关注水、土、气、生等自然地理过程,聚焦区域水文、土壤过程及其耦合机制,系统研究土壤微生物碳氮转化过程,理解人类活动与全球环境变化对主要自然地理过程的影响机理,评估过程耦合的区域资源环境效应及对社会经济的影响。
（3）观测数据—陆地表层系统模型融合系统。聚焦全球环境变化与陆地表层系统的相互作用和调控研究,重点理解主要陆地过程对外界扰动响应的敏感性和恢复机制,优化和完善观测数据—陆地表层系统融合的陆面模式,量化陆地表层系统的变化特征与调控途径。
（4）基于土地生态系统服务的自然地理综合研究。在自然地理要素与过程研究的基础上,以土地生态系统及其提供的服务为综合分析对象,重点突破土地系统变化及其生态效应、区域生态风险管理及生态安全格局优化,以及近远程视角下的生态系统服务流空间制图、驱动机理、效应评估、情景模拟和动态调控。
（5）面向景观可持续性提升的流域综合管理。结合“未来地球”等国际研究计划对可持续性议题的高度关注,基于流域自然生态过程的整体性,以水文过程链接土壤、植被、大气等自然地理要素,通过土地利用关联人类社会经济活动及发展战略,耦合关联流域土地利用与水文过程,模拟不同流域发展情景的景观可持续性响应,优化流域综合管理策略、提升全球变化适应能力。
The authors have declared that no competing interests exist.
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| [1] | 地理学是一门以综合性和区域性见长的学科.地理学的综合性通过要素多样化来体现,区域性则表现为区域分异或区域差异.地理学综合研究是对地球表层各要素的相互作用以及人地关系的研究,帮助我们认识地球表层系统的过去、现状和未来的趋势,把握其变化的脉搏.格局是认识世界的表观,过程是理解事物变化的机理,基于长期的野外观测和综合调查以及模型模拟,对不同时空尺度下的地理格局与过程进行耦合研究,是从机理上理解与解决地理学综合研究的有效途径与方法.文章结合在黄土高原地区的相关研究案例,探讨了将格局与过程耦合研究的地理学综合研究的途径与方法. . 地理学是一门以综合性和区域性见长的学科.地理学的综合性通过要素多样化来体现,区域性则表现为区域分异或区域差异.地理学综合研究是对地球表层各要素的相互作用以及人地关系的研究,帮助我们认识地球表层系统的过去、现状和未来的趋势,把握其变化的脉搏.格局是认识世界的表观,过程是理解事物变化的机理,基于长期的野外观测和综合调查以及模型模拟,对不同时空尺度下的地理格局与过程进行耦合研究,是从机理上理解与解决地理学综合研究的有效途径与方法.文章结合在黄土高原地区的相关研究案例,探讨了将格局与过程耦合研究的地理学综合研究的途径与方法. |
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| [3] | . Reviews the book "Unifying Geography: Common Heritage, Shared Future," edited by J. A. Matthews and D. T. Herbert. |
| [4] | Geomorphology offers an effective entry point into wider debates across geography and the sciences, framing understandings of landscapes as manifestations of complex and emergent relationships that can be used as a platform to support conversations among multiple and diverse worldviews. Physical geographers have much to contribute in moving beyond monological (one only) views of landscapes. This paper draws upon concepts of emergence, connectivity and space-time relationality to develop an 0900ethnogeomorphic0964 outlook upon biophysical-and-cultural (0900living0964) landscapes. This perspective is grounded through ethnographic case studies with Indigenous1 communities in Australia and Canada that examine knowledge production and concerns for environmental negotiation and decision-making. Extending beyond a traditional approach to ethnosciences, ethnogeomorphology seeks to move beyond cross-disciplinary scientific disciplines (and their associated epistemologies) towards a shared (if contested) platform of knowledge transfer and communication that reflects multiple ways of connecting to landscapes. Convergent perspectives upon landscape understandings are highlighted from Indigenous knowledges and emerging, relational approaches to geomorphic analysis. Ethnogeomorphology presents a situated, non-relativist response to people09“landscape connections that reflects and advocates sentient relationships to place. Potential applications of ethnogeomorphology as an integrating theme of geographic inquiry are explored, highlighting important tensions in the knowledge production process. |
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| [6] | 未来地球计划是目前国际上关于全球环境变化前沿研究的综合科学计划,集国际科学理事会(ICSU)所领导的四大科学计划为一体,旨在将自然科学与社会科学结合在一起,并加强决策支持和研究交流,寻求地球系统可持续途径,全球环境变化研究与人类学、社会学合作构建综合集成平台,推进科学研究为社会经济可持续发展服务。本文剖析陆地表层格局特点,分析陆地表层格局的国内外关注焦点及其研究理念的转变与应用领域的拓展。分析表明:陆地表层是未来地球计划关注的重点之一,陆地表层要素与过程相互作用并在人类活动驱动下形成的格局,可作为未来地球计划进一步研究的区域基础框架。未来,陆地表层格局研究应力求方法论的突破,为自然地理学综合研究的发展提供支撑。 . 未来地球计划是目前国际上关于全球环境变化前沿研究的综合科学计划,集国际科学理事会(ICSU)所领导的四大科学计划为一体,旨在将自然科学与社会科学结合在一起,并加强决策支持和研究交流,寻求地球系统可持续途径,全球环境变化研究与人类学、社会学合作构建综合集成平台,推进科学研究为社会经济可持续发展服务。本文剖析陆地表层格局特点,分析陆地表层格局的国内外关注焦点及其研究理念的转变与应用领域的拓展。分析表明:陆地表层是未来地球计划关注的重点之一,陆地表层要素与过程相互作用并在人类活动驱动下形成的格局,可作为未来地球计划进一步研究的区域基础框架。未来,陆地表层格局研究应力求方法论的突破,为自然地理学综合研究的发展提供支撑。 |
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| [16] | Using phenological and normalized difference vegetation index (NDVI) data from 1982 to 1993 at seven sample stations in temperate eastern China, we calculated the cumulative frequency of leaf unfolding and leaf coloration dates for deciduous species every 5 days throughout the study period. Then, we determined the growing season beginning and end dates by computing times when 50% of the species had undergone leaf unfolding and leaf coloration for each station year. Next, we used these beginning and end dates of the growing season as time markers to determine corresponding threshold NDVI values on NDVI curves for the pixels overlaying phenological stations. Based on a cluster analysis, we determined extrapolation areas for each phenological station in every year, and then implemented the spatial extrapolation of growing season parameters from the seven sample stations to all possible meteorological stations in the study area.Results show that spatial patterns of growing season beginning and end dates correlate significantly with spatial patterns of mean air temperatures in spring and autumn, respectively. Contrasting with results from similar studies in Europe and North America, our study suggests that there is a significant delay in leaf coloration dates, along with a less pronounced advance of leaf unfolding dates in different latitudinal zones and the whole area from 1982 to 1993. The growing season has been extended by 1.4-3.6 days per year in the northern zones and by 1.4 days per year across the entire study area on average. The apparent delay in growing season end dates is associated with regional cooling from late spring to summer, while the insignificant advancement in beginning dates corresponds to inconsistent temperature trend changes from late winter to spring. On an interannual basis, growing season beginning and end dates correlate negatively with mean air temperatures from February to April and from May to June, respectively. |
| [17] | Rapid temperature increase and its impacts on alpine ecosystems in the Qinghai-Tibetan Plateau, the world's highest and largest plateau, are a matter of global concern. Satellite observations have revealed distinctly different trend changes and contradicting temperature responses of vegetation green-up dates, leading to broad debate about the Plateau's spring phenology and its climatic attribution. Large uncertainties in remote-sensing estimates of phenology significantly limit efforts to predict the impacts of climate change on vegetation growth and carbon balance in the Qinghai-Tibetan Plateau, which are further exacerbated by a lack of detailed ground observation calibration. Here, we revealed the spatiotemporal variations and climate drivers of ground-based herbaceous plant green-up dates using 72 green-up datasets for 22 herbaceous plant species at 23 phenological stations, and corresponding daily mean air temperature and daily precipitation data from 19 climate stations across eastern and southern parts of the Qinghai-Tibetan Plateau from 1981 to 2011. Results show that neither the continuously advancing trend from 1982 to 2011, nor a turning point in the mid to late 1990s as reported by remote-sensing studies can be verified by most of the green-up time series, and no robust evidence for a warmer winter-induced later green-up dates can be detected. Thus, chilling requirements may not be an important driver influencing green-up responses to spring warming. Moreover, temperature-only control of green-up dates appears mainly at stations with relatively scarce preseason snowfall and lower elevation, while coupled temperature and precipitation controls of green-up dates occur mostly at stations with relatively abundant preseason snowfall and higher elevation. The diversified interactions between snowfall and temperature during late winter to early spring likely determine the spatiotemporal variations of green-up dates. Therefore, prediction of vegetation growth and carbon balance responses to global climate change on the world's roof should integrate both temperature and snowfall variations. |
| [18] | This work was undertaken to examine the combined effect of air temperature and precipitation during late winter and early spring on modeling greenup date of grass species in the Inner Mongolian Grassland. We used the traditional thermal time model and developed two revised thermal time models coupling air temperature and precipitation to simulate greenup date of three dominant grass species at six stations from 1983 to 2009. Results show that climatic controls on greenup date of grass species were location-specific. The revised thermal time models coupling air temperature and precipitation show higher simulation parsimony and efficiency than the traditional thermal time model for five of 11 data sets at Bayartuhushuo, Xilinhot and Xianghuangqi, whereas the traditional thermal time model indicates higher simulation parsimony and efficiency than the revised thermal time models coupling air temperature and precipitation for the other six data sets at E rgunayouqi, Ewenkeqi and Chaharyouyihouqi. The mean root mean square error of the 11 models is 4.9 days. Moreover, the influence of late winter and early spring precipitation on greenup date seems to be stronger at stations with scarce precipitation than at stations with relatively abundant precipitation. From the mechanism perspectives, accumulated late winter and early spring precipitation may play a more important role as the precondition of forcing temperature than as the supplementary condition of forcing temperature in triggering greenup. Our findings suggest that predicting responses of grass phenology to global climate change should consider both thermal and moisture scenarios in some semiarid and arid areas. |
| [19] | Using Ulmus pumila (Siberian Elm) leaf unfolding and leaf fall phenological data from 46 stations in the temperate zone of China for the period 1986–2005, we detected linear trends in both start and end dates and length of the growing season. Moreover, we defined the optimum length period during which daily mean temperature affects the growing season start and end dates most markedly at each station in order to more precisely and rationally identify responses of the growing season to temperature. On average, the growing season start date advanced significantly at a rate of 614.002days per decade, whereas the growing season end date was delayed significantly at a rate of 2.202days per decade and the growing season length was prolonged significantly at a rate of 6.502days per decade across the temperate zone of China. Thus, the growing season extension was induced mainly by the advancement of the start date. At individual stations, linear trends of the start date correlate negatively with linear trends of spring temperature during the optimum length period, namely, the quicker the spring temperature increased at a station, the quicker the start date advanced. With respect to growing season response to interannual temperature variation, a 1°C increase in spring temperature during the optimum length period may induce an advancement of 2.802days in the start date of the growing season, whereas a 1°C increase in autumn temperature during the optimum length period may cause a delay of 2.102days in the end date of the growing season, and a 1°C increase in annual mean temperature may result in a lengthening of the growing season of 902days across the temperate zone of China. Therefore, the response of the start date to temperature is more sensitive than the response of the end date. At individual stations, the sensitivity of growing season response to temperature depends obviously on local thermal conditions, namely, either the negative response of the start date or the positive response of the end date and growing season length to temperature was stronger at warmer locations than at colder locations. Thus, future regional climate warming may enhance the sensitivity of plant phenological response to temperature, especially in colder regions. |
| [20] | . We used Ulmus pumila leaf unfolding and leaf fall data collected at 46 stations during the 1986–2005 period to construct and validate daily temperature-based spatial phenology models. These models allowed simulation of the 20-year mean and yearly spatial patterns of U. pumila growing season beginning and end dates. This work was undertaken to explore the ecological mechanisms driving tree phenology spatial patterns and examine tree phenology spatial responses to temperature across China's temperate zone. The results show that spatial patterns of daily temperatures within the optimum spring and autumn length periods control spatial patterns of growing season beginning and end dates, respectively. Regarding 20-year mean growing season modeling, mean growing season beginning date correlates negatively with mean daily temperature within the optimum spring length period at the 46 stations. The mean spring spatial phenology model explained 90% of beginning date variance ( P < 0.001) with a Root Mean Square Error (RMSE) of 4.6 days. In contrast, mean growing season end date correlates positively with mean daily temperature within the optimum autumn length period at the 46 stations. The mean autumn spatial phenology model explained 82% of end date variance ( P < 0.001) with a RMSE of 5.6 days. On average, a spatial shift in mean spring and autumn daily temperatures by 1 °C may induce a spatial shift in mean beginning and end dates by 613.1 days and 2.6 days, respectively. Similarly, a significant negative and positive correlation was detectable between beginning date and spring daily temperature and between end date and autumn daily temperature at the 46 stations for each year, respectively. In general, the explained variances for yearly spatial phenology models are less than those of mean spatial phenology models, whereas the RMSEs of yearly models are greater than those of mean models. On average, a spatial shift in spring and autumn daily temperatures by 1 °C in a year may induce a spatial shift in beginning and end dates between 614.28 days and 612.75 days and between 2.17 days and 3.16 days in the year, respectively. Moreover, both mean and yearly spatial phenology models perform satisfactorily in predicting beginning and end dates of the U. pumila growing season at external stations. Further analysis showed that the negative spatial response of yearly beginning date to spring daily temperature was stronger in warmer years than in colder years. This finding suggests that climate warming in late winter and spring may enhance sensitivity of the growing season's spatial response due to the relationship of beginning date to temperature. |
| [21] | . Climate drivers of plant phenology in the subtropics and tropics are still unclear, which significantly hinders accurate prediction of climate change impacts on vegetation growth and carbon balance in these unique ecoregions. The basic hypothesis of process-based phenology models is that spring tree phenology is regulated by temperature and triggered by chilling temperatures during the dormancy period, followed by forcing temperatures during the growth period. That is, trees require cool temperatures during a chilling period to break endodormancy, and then enter the phase of ecodormancy during which the rate of ontogenetic development increases with increasing air temperature. Therefore, insufficient chilling requirements may slow bud growth and consequently delay budburst. Many studies have shown that chilling requirement is at present sufficient to release bud dormancy fully in temperate regions, and thus forcing temperatures play a dominant role in triggering spring tree phenology. To identify differences in mechanisms of spring tree phenology responses to air temperature between the subtropics/tropics and the temperate zone, and their possible effects on future phenological trends under global warming, we used leaf unfolding and flowering data from a tree species of tropical origin,Melia azedarach, and output daily mean air temperature data from a regional climate model (HadGEM3-RA) for the period 1981鈥2005 at 42 stations in southeastern China to fit unified forcing and chilling phenology models. Then, we selected optimum models for each phenophase at each station. Moreover, we predicted leafing and flowering dates across the research region over 2021 2100 under global climate warming scenarios. The results show a previously unreported phenological phenomenon: chilling will often be insufficient to break bud dormancy in the northern tropical zone and may become a crucial factor limiting leafing and flowering responses to spring warming. However, chilling will still be sufficient to break bud dormancy in the warm temperate zone, and thus may not limit leafing and flowering responses to spring warming there. Consequently, predicted leafing and flowering dates both will be delayed in the northern tropical zone but will advance in the warm temperate zone from 2021 to 2100. In the subtropical zone, the effect of chilling temperature on spring phenology will be reduced gradually from earlier to later phenophases. Thus, predicted leafing and flowering dates show decreased delaying trends and increased advancing trends from earlier to later phenophases in the subtropical zone. Our findings suggest that insufficient chilling temperature accumulation during the dormancy period may counteract the forcing temperature accumulation during the growth period in the northern tropical zone and parts of the subtropical zone, resulting in delayed leafing and flowering dates. |
| [22] | Using first leaf unfolding data of Salix matsudana, Populus simonii, Ulmus pumila, and Prunus armeniaca, and daily mean temperature data during the 1981–2005 period at 136 stations in northern China, we fitted unified forcing and chilling phenology models and selected optimum models for each species at each station. Then, we examined performances of each optimum local species-specific model in predicting leaf unfolding dates at all external stations within the corresponding climate region and selected 16 local species-specific models with maximum effective predictions as the regional unified models in different climate regions. Furthermore, we validated the regional unified models using leaf unfolding and daily mean temperature data beyond the time period of model fitting. Finally, we substituted gridded daily mean temperature data into the regional unified models, and reconstructed spatial patterns of leaf unfolding dates of the four tree species across northern China during 1960–2009. At local scales, the unified forcing model shows higher simulation efficiency at 83% of data sets, whereas the unified chilling model indicates higher simulation efficiency at 17% of data sets. Thus, winter temperature increase so far has not yet significantly influenced dormancy and consequent leaf development of deciduous trees in most parts of northern China. Spatial and temporal validation confirmed capability and reliability of regional unified species-specific models in predicting leaf unfolding dates in northern China. Reconstructed leaf unfolding dates of the four tree species show significant advancements by 1.4–1.6 days per decade during 1960–2009 across northern China, which are stronger for the earlier than the later leaf unfolding species. Our findings suggest that the principal characteristics of plant phenology and phenological responses to climate change at regional scales can be captured by phenological and climatic data sets at a few representative locations. |
| [23] | A gridded data set of daily precipitation records together with percentile-based precipitation indices was utilized to analyze changes in spatiotemporal pattern of precipitation across China in the last 33 years (1980 2012). Identifiable changes in precipitation structure and distinctive spatial variations in precipitation trends were detected at both annual and seasonal timescales. Generally, a slight but discernable increasing trend was observed in annual precipitation, and precipitation increased during summer and winter but decreased in spring and autumn. In addition, great differences were distinguished in the aspects of precipitation day, precipitation amount and precipitation duration among light, moderate and heavy precipitation. Additional analyses of extreme events including wet day, very wet day, daily maximum precipitation, short dry period and long dry period, were also performed, which indicated an upward trend in days with more precipitation. Study of contributions to the precipitation day and amount showed that light and moderate precipitation contributed greatly to the precipitation day while moderate and heavy precipitation contributed greatly to the precipitation amount. Finally, it could be concluded that it was getting drier in southeast China but wetter in southwest China, with severe droughts in northwest China being relieved during the last 33 years. |
| [24] | 在中国干旱半干旱地区日气象数据分析的基础上,依据彭曼公式计算出潜在蒸散量,以及生长季内的年平均降水量与潜在蒸散量二者的差值,利用空间分异分析,气候倾向率检测,以及时间序列MK突变检验等方法分析了降水量与潜在蒸散量的时空变化特征。结果表明:总体来看,我国干旱半干旱区50年来东、西部的气候变化有明显的差异,西北地区降水量增加,潜在蒸散量减少,干旱化程度在减轻,且变化十分显著。而东部干旱半干旱区降水量减少,潜在蒸散量增加,干旱化严重。 . 在中国干旱半干旱地区日气象数据分析的基础上,依据彭曼公式计算出潜在蒸散量,以及生长季内的年平均降水量与潜在蒸散量二者的差值,利用空间分异分析,气候倾向率检测,以及时间序列MK突变检验等方法分析了降水量与潜在蒸散量的时空变化特征。结果表明:总体来看,我国干旱半干旱区50年来东、西部的气候变化有明显的差异,西北地区降水量增加,潜在蒸散量减少,干旱化程度在减轻,且变化十分显著。而东部干旱半干旱区降水量减少,潜在蒸散量增加,干旱化严重。 |
| [25] | . |
| [26] | 在全球大幅度变暖的背景下,西北地区的气候变化及其响应受到越来越多的关注。为了进一步探讨其气候变化过程与机理在时间与空间上变化的差异性,选取中国西北地区(80°E～115°E,32°N～50°N)1961-2004年140个气象台站逐日降水、日照、风速、水汽压、温度等资料,根据Penman公式计算了潜在蒸散量,并根据其与降水的关系建立了干燥度指数。采用自组织特征映射神经网络的方法,根据上述多种物理量进行西北地区内部的气候区划,寻找不同的区域异常中心。在此基础上,采用正交小波分解的方法,对各异常区域中心的干燥度序列进行分析。最后对北大西洋涛动指数对我国西北地区的区域气候变化的影响进行多时间尺度的相关分析,并从大气环流异常的角度解释其影响机制。 . 在全球大幅度变暖的背景下,西北地区的气候变化及其响应受到越来越多的关注。为了进一步探讨其气候变化过程与机理在时间与空间上变化的差异性,选取中国西北地区(80°E～115°E,32°N～50°N)1961-2004年140个气象台站逐日降水、日照、风速、水汽压、温度等资料,根据Penman公式计算了潜在蒸散量,并根据其与降水的关系建立了干燥度指数。采用自组织特征映射神经网络的方法,根据上述多种物理量进行西北地区内部的气候区划,寻找不同的区域异常中心。在此基础上,采用正交小波分解的方法,对各异常区域中心的干燥度序列进行分析。最后对北大西洋涛动指数对我国西北地区的区域气候变化的影响进行多时间尺度的相关分析,并从大气环流异常的角度解释其影响机制。 |
| [27] | ABSTRACT In order to detect daily temperature trend in eastern China, observed daily temperature data spanning over 32 years (1979 2010) including daily maximum temperature ( T max), minimum temperature ( T min) and mean temperature ( T avg) were analysed. Besides, land cover conversions in grassland/cropland around 102 meteorological stations were also investigated to explore the sensitivity of temperature to grassland/cropland. Increasing trends were detected in observed T max and T min, with distinct connection to the distribution of grassland/cropland. T max changed greatly in grassland and T min in cropland. Besides, unique seasonal and spatial variability was discovered in T max and T min, respectively. Finally, percentile-based temperature indices derived from observed daily temperature data were further involved to demonstrate the sensitivity of temperature extremes to grassland/cropland, which showed that the annual occurrences of warm day, summer heat wave and winter warm night events were increasing, while those of cold night were decreasing. Analysis of thresholds that distinguished summer heat wave and winter warm night events suggested higher temperature in grassland. |
| [28] | 利用气象观测减再分析资料方法(OMR)研究了中国不同土地覆被的地表气温变化。使用1979?2007年的地面观测气温和NCEP/NCAR R1再分析地表气温月数据, 计算了OMR趋势, 得到中国OMR气温趋势为+0.18℃/10a。采用AVHRR全球土地覆被分类数据统计中国不同土地覆被的OMR气温趋势。结果表明地表气温变化对不同土地覆被的敏感性存在差异。大部分土地覆被类型OMR趋势为正, 森林覆被型为负。不同土地网格阈值下的OMR结果相差不大, 说明这种方法的可靠性。 . 利用气象观测减再分析资料方法(OMR)研究了中国不同土地覆被的地表气温变化。使用1979?2007年的地面观测气温和NCEP/NCAR R1再分析地表气温月数据, 计算了OMR趋势, 得到中国OMR气温趋势为+0.18℃/10a。采用AVHRR全球土地覆被分类数据统计中国不同土地覆被的OMR气温趋势。结果表明地表气温变化对不同土地覆被的敏感性存在差异。大部分土地覆被类型OMR趋势为正, 森林覆被型为负。不同土地网格阈值下的OMR结果相差不大, 说明这种方法的可靠性。 |
| [29] | 随着城市化进程的加快，城市气候与环境问题日益显现，尤以城市热岛效应最为突出。通过监督分类方法对TM遥感影像进行了土地利用分类，并运用TM热红外波段线性拟合模型进行近地表气温反演，分析城市热岛的空间分布及地域性差异，以及与土地利用类型的关系。结果表明：珠三角地区近地表气温与土地利用类型紧密相关，城市建设区形成高温中心，是热岛的主要贡献因子，植被和水体则有明显的冷岛效应；研究区热岛具有区域性集中与分散分布的特点，且以区域性热岛为中心向周边扩展；分析热岛强度剖面线发现，由于地形、植被覆盖度等因素影响，研究区热岛强度的南北差异较大，而东西差异较小；热岛分布与土地利用类型分布格局较为一致，但也有分布不一致性的区域，表现为城市热岛向非城市建设用地扩展。 . 随着城市化进程的加快，城市气候与环境问题日益显现，尤以城市热岛效应最为突出。通过监督分类方法对TM遥感影像进行了土地利用分类，并运用TM热红外波段线性拟合模型进行近地表气温反演，分析城市热岛的空间分布及地域性差异，以及与土地利用类型的关系。结果表明：珠三角地区近地表气温与土地利用类型紧密相关，城市建设区形成高温中心，是热岛的主要贡献因子，植被和水体则有明显的冷岛效应；研究区热岛具有区域性集中与分散分布的特点，且以区域性热岛为中心向周边扩展；分析热岛强度剖面线发现，由于地形、植被覆盖度等因素影响，研究区热岛强度的南北差异较大，而东西差异较小；热岛分布与土地利用类型分布格局较为一致，但也有分布不一致性的区域，表现为城市热岛向非城市建设用地扩展。 |
| [30] | Human activity is an important contributor to local temperature change, especially in urban areas. Energy consumption is treated here as an index of the intensity of human induced local thermal forcing. The relationship between energy consumption and temperature change is analyzed in China by Observation Minus Reanalysis (OMR) method. Temperature trends for observation, reanalysis and OMR are estimated from meteorological records and 2 m-temperature from NCEP/NCAR Reanalysis 1 for the period 1979-2007. A spatial mapping scheme based on the spatial and temporal relationship between energy consumption and Gross Domestic Production (GDP) is developed to derive the spatial distribution of energy consumption of China in 2003. A positive relationship between energy consumption and OMR trends is found in high and mid energy consumption region. OMR trends decline with the decreasing intensity of human activity from 0.20 C/decade in high energy consumption region to 0.13 C/decade in mid energy consumption region. Forty-four stations in high energy consumption region that are exposed to the largest human impact are selected to investigate the impact of energy consumption spatial pattern on temperature change. Results show human impact on temperature trends is highly dependent on spatial pattern of energy consumption. OMR trends decline from energy consumption center to surrounding areas (0.26 to 0.04 C/decade) and get strengthened as the spatial extent of high energy consumption area expands (0.14 to 0.25 C/decade). |
| [31] | The impact of urbanization on temperature trends in China was investigated with emphasis on two aspects of urbanization, land cover change, and human activity. A new station classification scheme was developed to incorporate these two aspects by utilizing land cover and energy consumption data. Observation temperature data of 274 stations and National Centers for Environmental Prediction (NCEP)-National Center for Atmospheric Research (NCAR) reanalysis temperature from 1979 to 2010 were used in conducting the observation minus reanalysis (OMR) method to detect urban influence. Results indicated that nearly half of the stations in the study area have been converted from nonurban to urban stations as a result of land cover change associated with urban expansion. It was determined that both land cover change and human activity play important roles in temperature change and contribute to the observed warming, particularly in urbanized stations, where the highest amount of warming was detected. Urbanized stations showed higher OMR temperature trends than those of unchanged stations. In addition, a statistically significant positive relationship was detected between human activity and temperature trends, which suggests that the observed warming is closely related to the intensity and spatial extent of human activity. In fact, the urbanization effect is strongly affected by specific characteristics of urbanization in local and regional scales. |
| [32] | 进入21世纪,我国珠江三角洲地区城市化规模越来越大,研究该地 区的热岛效应具有重要的现实意义.研究区21世纪初自动气象站点运行趋于稳定,数据质量好,为城市气候研究提供了数据基础.利用2000-2003年的珠 江三角洲城市群自动气象站温度数据进行空间分析,统计热岛和冷岛出现的频率,总结空间分布规律,并对照土地利用类型图分析热岛区域与地表覆被的对应关系. 计算每月热岛强度值,通过热岛的月际变化曲线,总结热岛的年变化规律以及昼夜差异.研究结果表明,研究区城市热岛呈现"六区两带"的空间分布格局;全年中 夏季白天的热岛强度最大,并且夏季的热岛强度出现昼强夜弱的现象. . 进入21世纪,我国珠江三角洲地区城市化规模越来越大,研究该地 区的热岛效应具有重要的现实意义.研究区21世纪初自动气象站点运行趋于稳定,数据质量好,为城市气候研究提供了数据基础.利用2000-2003年的珠 江三角洲城市群自动气象站温度数据进行空间分析,统计热岛和冷岛出现的频率,总结空间分布规律,并对照土地利用类型图分析热岛区域与地表覆被的对应关系. 计算每月热岛强度值,通过热岛的月际变化曲线,总结热岛的年变化规律以及昼夜差异.研究结果表明,研究区城市热岛呈现"六区两带"的空间分布格局;全年中 夏季白天的热岛强度最大,并且夏季的热岛强度出现昼强夜弱的现象. |
| [33] | |
| [34] | Mineral magnetic properties (SIRM, ARM, HIRM and S-ratios) are presented for two AMS 14C-dated pit-sequences of lake sediments recovered from Haoluku and Liuzhouwan (6543°N, 117°E). The two sites fall in the semi-humid to semi-arid climate transition zone, Dali Nor area of the southeast Inner Mongolia Plateau, China. Complemented by data for loss-on-ignition (LOI), total organic carbon (TOC), carbon/nitrogen (C/N), grain-size, and pollen, these mineral-magnetic measurements provide additional insights into environmental changes occurring at this area over the last 1364500 years. Conditions were extremely dry and windy as shown by the low SIRM, ARM and HIRM and high S-ratios before 1364500 yr bp. The environment began to ameliorate gradually since then, and a further humidification occurred at 651064300 yr bp in Haoluku, the northern site, and at 659400 yr bp in Liuzhouwan, the southern one, as implied by the increased but only moderately high SIRM, ARM and HIRM and decreased S-ratios. As indicated by the remarkably increased SIRM, ARM, HIRM and S-ratios, a deterioration commenced at 655600 yr bp in Haoluku and at 654700 yr bp in Liuzhouwan. In Haoluku, conditions have been generally dry and windy since 655600 yr bp despite a minor amelioration at 4500–3000 yr bp. A short but marked amelioration occurred at 1200–700 yr bp in Liuzhouwan. S-ratios seem to be a reliable indicator of environmental aridity for this area. |
| [35] | Two cores, one 1141-cm long (An-S) and the other 885-cm long (An-A), were retrieved from Anguli-nuur Lake (41 degrees 18'-24'N, 114 degrees 20'-27'E, similar to 1315 masl), one of the largest lakes in the transition zone between a semi-humid and semi-arid climate parallel to the present limit of the southeast monsoon along the southeastern Inner Mongolia Plateau in north China. Mineral-magnetic parameters (chi(If), ARM, IRM300mT, SIRM and IRM-300mT) were measured on An-S and two additional parameters (chi(ARM) and HIRM) and four inter-parametric ratios (chi(ARM)/SIRM, IRM300mT/SIRM, IRM-300mT/SIRM and SIRM/chi(If)) were calculated. Potential sources of these lake sediments (catchment soils and dune materials close to the lake and in a distant sand plain) were sampled, and the magnetic properties of the surface-material specimens were measured. A chronological model was developed for An-S by comparing and combining AMS(14)C dates of An-S with Cs-137, Pb-210 and AMS(14)C dates of An-A. With the help of surface-material magnetism, the magnetic data of An-S in combination with particle size, TOC and C/N and pollen analyses indicate the environmental changes during the last similar to 10,000 years around this lake. Conditions began to ameliorate at 10,900 cal.yr BP (9600 C-14 yrBP) and thus relatively wet and warm environments prevailed during 10,900-8900 cal. yr BP (9600-8000 C-14 yr BP). The Holocene optimum or the wettest and warmest conditions, was during 8900-7400 cal. yr BP (8000-6500 C-14 yr BP). The environment began to deteriorate from 7400 cal. yr BP (6500 C-14 yr BP) and the driest and coolest conditions occurred during 2200-480 cal. yr BP. There may have been a minor amelioration after 480 cal. yr BP. The inferred changes in palaeoenvironmental conditions around Anguli-nuur Lake are broadly in agreement with those around most other sites on the Inner Mongolia Plateau. |
| [36] | Previous studies have demonstrated long-term changes in effective moisture in sub-Saharan Africa. Here, we reconstruct Holocene environments using a 7 m lake-sediment sequence recovered from the northeastern Nigerian Sahel and attempt to distinguish basin-specific changes from regional climatic variations. The sequence was analysed for sedimentological properties, mineral magnetism and pollen, and dated by 137Cs, 210Pb excess and 14C. Extremely arid conditions of the terminal Pleistocene ended ca. 11 500 cal. BP (calendar years) when climate ameliorated and a lake developed until the occurrence of an arid event leading to lake desiccation at 11 200 cal. BP. Following this, climate ameliorated and a water body re-emerged. Very wet conditions predominated 11 200-5600 cal. BP, followed by drought between 5600 and 5500 cal. BP and a return to moderate humidity from 5500 to 4000 cal. BP. After 4000 cal. BP, a marked deterioration occurred, culminating in lake desiccation at ca. 800 cal. BP. After this time the climate remained generally dry and the re-emerging lake was shallow. Comparison of these results with other well-dated sequences in the region demonstrates the importance of basin-specific influences on the palaeolimnological records in addition to regional climatic controls. Disentangling these different controls, as well as the reconstruction of Holocene climate, therefore requires a multiple-basin approach. Copyright 2008 John Wiley & Sons, Ltd. |
| [37] | The Qinling Mountain Range (33°–34°30′N, 107°–111°E; 3,767m a.s.l.) lies south of the Chinese Loess Plateau and functions as the boundary between ‘north’ and ‘south’ China. Taibai Mountain (33°41′–34°10′N, 107°19′–107°58′E; 3,767m a.s.l.) is the central massif and highest part of the range and is the highest mountain in eastern and central China, east of 105°E. It is also one of two mountains higher than the modern climatic timberline and the only one where high alpine lakes (>2,500m a.s.l.) exist in eastern and central China. Sediments were recovered from Foye Chi (33°57′N, 107°44′E; 3,410m a.s.l.), a small lake on the southern slope of the mountain, and measured for magnetic properties. Chronological control was achieved with AMS 14 C dating. Combined with analyses of particle-size, TOC, C/N, δ 13 C org and pollen in these sediments, and magnetic properties of catchment soils, the mineral-magnetic data reveal late Holocene palaeoenvironmental changes on the high-altitude southern slope of Taibai Mountain. Climate gradually ameliorated about 2,300calyrBP and warm and wet conditions occurred afterwards, culminating from 1,700 to 1,510calyrBP. The climate began to deteriorate at 1,510calyrBP, but was still warmer and wetter than present until ~663calyrBP. Cool, arid conditions peaked and were cooler and drier than the present at 663–290calyrBP, coincident with the Little Ice Age. Climate became warmer and more humid again after 290calyrBP. Data from these less anthropologically-disturbed alpine-lake sediments provide a record of late Holocene palaeoenvironmental change that supplements information from historical documents and literature for eastern and central China. |
| [38] | |
| [39] | 61LN-Nraterelationship is convex and varies by local hydro-climates and SOC.61Variability of temperature explains a half of spatial variation of N leaching rate.61LNin 2008 were 0.8802±020.2302Tg, lower than the linear or uniform models.61Reducing LNshould consider background rather than decreasing Nratesolely. |
| [40] | Accumulating evidence indicates that N2O emission factors (EFs) vary with nitrogen additions and environmental variations. Yet the impact of the latter was often ignored by previous EF determinations. We developed piecewise statistical models (PMs) to explain how the N2O EFs in agricultural soils depend upon various predictors such as climate, soil attributes, and agricultural management. The PMs are derived from a new Bayesian Recursive Regression Tree algorithm. The PMs were applied to the case of EFs from agricultural soils in China, a country where large EF spatial gradients prevail. The results indicate substantial improvements of the PMs compared with other EF determinations. First, PMs are able to reproduce a larger fraction of the variability of observed EFs for upland grain crops (86%, n=381) and paddy rice (91%, n=161) as well as the ratio of EFs to N application rates (73%, n=96). The superior predictive accuracy of PMs is further confirmed by evaluating their predictions against independent EF measurements (n=285) from outside China. Results show that the PMs calibrated using Chinese data can explain between 73%~83% of the variance. Hence the PMs could be reliable for upscaling of N2O EFs and fluxes for regions that have a phase-space of predictors similar to China. Results from the validated models also suggest that climatic factors regulate the heterogeneity of EFs in China, explaining 69% and 85% of their variations for upland grain crops and paddy rice, respectively. The corresponding N2O EFs in 2008 are 0.84卤0.16% (as N2O-N emissions divided by the total N input) for upland grain crops and 0.65卤0.14% for paddy rice, the latter being twice as large as the IPCC Tier 1 defaults. Based upon these new estimates of EFs, we infer that only 20% of current arable land could achieve a potential reduction of N2O emission of 50%. |
| [41] | |
| [42] | Abstract In the recent Intergovernmental Panel on Climate Change assessment, multimodel ensembles (arithmetic model averaging, AMA) were constructed with equal weights given to Earth system models, without considering the performance of each model at reproducing current conditions. Here we use Bayesian model averaging (BMA) to construct a weighted model ensemble for runoff projections. Higher weights are given to models with better performance in estimating historical decadal mean runoff. Using the BMA method, we find that by the end of this century, the increase of global runoff (9.8 1.5%) under Representative Concentration Pathway 8.5 is significantly lower than estimated from AMA (12.2 1.3%). BMA presents a less severe runoff increase than AMA at northern high latitudes and a more severe decrease in Amazonia. Runoff decrease in Amazonia is stronger than the intermodel difference. The intermodel difference in runoff changes is mainly caused not only by precipitation differences among models, but also by evapotranspiration differences at the high northern latitudes. |
| [43] | The amount and geographic distribution of N2O emissions over China remain largely uncertain. In this study, county-level and 0.1 0.1 gridded anthropogenic N2O emission inventories for China (PKU-N2O) in 2008 are developed based on high-resolution activity data and regional emission factors (EFs) and parameters. These new estimates are compared with previous inventories, and with two sensitivity tests: one that uses high-resolution activity data but the default IPCC methodology (S1) and the other that uses regional EFs and parameters but starts from coarser-resolution activity data. The total N2O emissions are 2150 GgN2O/yr (interquartile range from 1174 to 2787 GgN2O/yr). Agriculture contributes 64% of the total, followed by energy (17%), indirect emissions (12%), wastes (5%), industry (2.8%), and wildfires (0.2%). Our national emission total is 17% greater than that of the EDGAR v4.2 global product sampled over China and is also greater than the GAINS-China, NDRC, and S1 estimates by 10%, 50%, and 17%, respectively. We also found that using uniform EFs and parameters or starting from national/provincial data causes systematic spatial biases compared to PKU-N2O. Spatial analysis shows nonlinear relationships between N2O emission intensities and urbanization. Per-capita and per-GDP N2O emissions increase gradually with an increase in the urban population fraction from 0.3 to 0.9 among 2884 counties, and N2O emission density increases with urban expansion. |
| [44] | We propose a well-balanced stable generalized Riemann problem (GRP) scheme for the shallow water equations with irregular bottom topography based on moving, adaptive, unstructured, triangular meshes. In order to stabilize the computations near equilibria, we use the Rankine-Hugoniot condition to remove a singularity from the GRP solver. Moreover, we develop a remapping onto the new mesh (after grid movement) based on equilibrium variables. This, together with the already established techniques, guarantees the well-balancing. Numerical tests show the accuracy, efficiency, and robustness of the GRP moving mesh method: lake at rest solutions are preserved even when the underlying mesh is moving (e.g., mesh points are moved to regions of steep gradients), and various comparisons with fixed coarse and fine meshes demonstrate high resolution at relatively low cost. Copyright (c) 2013 John Wiley & Sons, Ltd. |
| [45] | A new geometrical conservative interpolation on unstructured meshes is developed for preserving still water equilibrium and positivity of water depth at each iteration of mesh movement, leading to an adaptive moving finite volume (AMFV) scheme for modeling flood inundation over dry and complex topography. Unlike traditional schemes involving position‐fixed meshes, the iteration process of the AFMV scheme moves a fewer number of the meshes adaptively in response to flow variables calculated in prior solutions and then simulates their posterior values on the new meshes. At each time step of the simulation, the AMFV scheme consists of three parts: an adaptive mesh movement to shift the vertices position, a geometrical conservative interpolation to remap the flow variables by summing the total mass over old meshes to avoid the generation of spurious waves, and a partial differential equations(PDEs) discretization to update the flow variables for a new time step. Five different test cases are presented to verify the computational advantages of the proposed scheme over nonadaptive methods. The results reveal three attractive features: (i) the AMFV scheme could preserve still water equilibrium and positivity of water depth within both mesh movement and PDE discretization steps; (ii) it improved the shock‐capturing capability for handling topographic source terms and wet‐dry interfaces by moving triangular meshes to approximate the spatial distribution of time‐variant flood processes; (iii) it was able to solve the shallow water equations with a relatively higher accuracy and spatial‐resolution with a lower computational cost. |
| [46] | Various chemometric methods were used to analyze data sets of marine water quality for 19 parameters measured at 16 different sites of southern Hong Kong from 2000 to 2004 (18,240 observations), to determine temporal and spatial variations in marine water quality and identify pollution sources. Hierarchical cluster analysis (CA) grouped the 12 months into three periods (January-April, May-August and September-December) and the 16 sampling sites into two groups (A and B) based on similarities in marine water-quality characteristics. Discriminant analysis (DA) was important in data reduction because it used only eight parameters (TEMP, TURB, Si, NO(3)(-)-N, NH(4)(+)-N, NO(2)(-)-N, DO, and Chl-a) to correctly assign about 86% of the cases, and five parameters (SD, NH(4)(+)-N, TP, NO(2)(-)-N, and BOD(5)) to correctly assign >81.15% of the cases. In addition, principal component analysis (PCA) identified four latent pollution sources for groups A and B: organic/eutrophication pollution, natural pollution, mineral pollution, and nutrient/fecal pollution. Furthermore, during the second and third periods, all sites received more organic/eutrophication pollution and natural pollution than in the first period. SM5, SM6, SM17, SM10, SM11, SM12, and SM13 (second period) were affected by organic and eutrophication pollution, whereas SM3 (third period) and SM9 (second period) were influenced by natural pollution. However, differences between mineral pollution and nutrient/fecal pollution were not significant among the three periods. SM17 and SM10 were affected by mineral pollution, whereas SM4 and SM9 were highly polluted by nitrogenous nutrient/fecal pollution. |
| [47] | The comprehensive application of different multivariate methods and geographic information systems (GIS) was used to evaluate the spatio-temporal patterns and source apportionment of coastal water pollution in eastern Hong Kong. Fourteen variables were surveyed at 27 sites monthly from 2000 to 2004. After data pretreatment, cluster analysis grouped the 12 months into two groups, June-September and the remaining months, and divided the entire area into two parts, representing different pollution levels. Discriminant analysis determined that NO3- -N, DO, and temperature and TN, SD, PO4(3-)-P, and VSS were significant variables affecting temporal and spatial variations with 84% and 90% correct assignments, respectively. Five potential pollution sources were identified for each part by rotated principal component analysis, explaining 71% and 68% of the total variances, respectively. Receptor-based source apportionment revealed that most of the variables were primarily influenced by soil weathering and organic pollution, nutrient pollution (or agricultural runoff), and mineral pollution. Furthermore, GIS further facilitated and supported multivariate analysis results. |
| [48] | Elevated atmospheric nitrogen (N) deposition has significantly influenced aquatic ecosystems, especially with regard to their N budgets and phytoplankton growth potentials. Compared to a considerable number of studies on oligotrophic lakes and oceanic waters, little evidence for the importance of N deposition has been generated for eutrophic lakes, even though emphasis has been placed on reducing external N inputs to control eutrophication in these lakes. Our high-resolution observations of atmospheric depositions and riverine inputs of biologically reactive N species into eutrophic Lake Dianchi (the sixth largest freshwater lake in China) shed new light onto the contribution of N deposition to total N loads. Annual N deposition accounted for 15.7% to 16.6% of total N loads under variable precipitation conditions, 2-fold higher than previous estimates (7.6%) for the Lake Dianchi. The proportion of N deposition to total N loads further increased to 27 48% in May and June when toxic blooms of the ubiquitous... |
| [49] | 陆地生态系统存在许多常年性或季节性缺氧环境,如:湿地、水稻土、湖泊沉积物、动物瘤胃、垃圾填埋场和厌氧生物反应器等。每年有大量有机物质进入这些环境,在缺氧条件下发生厌氧分解。甲烷是有机质厌氧分解的最终产物。产生的甲烷气体可通过缺氧-有氧界面释放到大气,产生温室效应,是重要的温室气体。产甲烷过程是缺氧环境中有机质分解的核心环节,而甲烷氧化是缺氧-有氧界面的重要微生物过程。甲烷的产生和氧化过程共同调控大气甲烷浓度,是全球碳循环不可分割的组成部分。对陆地生态系统甲烷产生和氧化过程的微生物机理研究进展进行了概要回顾和综述。主要内容包括:新型产甲烷古菌即第六和第七目产甲烷古菌和嗜冷嗜酸产甲烷古菌的发现;短链脂肪酸中间产物互营氧化过程与直接种间电子传递机制;新型甲烷氧化菌包括厌氧甲烷氧化菌和疣微菌属好氧甲烷氧化菌的发现;甲烷氧化菌生理生态与环境适应的新机制。这些研究进展显著拓展了人们对陆地生态系统甲烷产生和氧化机理的认识和理解。随着新一代土壤微生物研究技术的发展与应用,甲烷产生和氧化微生物研究领域将面临更多机遇和挑战,对未来发展趋势做了展望。 . 陆地生态系统存在许多常年性或季节性缺氧环境,如:湿地、水稻土、湖泊沉积物、动物瘤胃、垃圾填埋场和厌氧生物反应器等。每年有大量有机物质进入这些环境,在缺氧条件下发生厌氧分解。甲烷是有机质厌氧分解的最终产物。产生的甲烷气体可通过缺氧-有氧界面释放到大气,产生温室效应,是重要的温室气体。产甲烷过程是缺氧环境中有机质分解的核心环节,而甲烷氧化是缺氧-有氧界面的重要微生物过程。甲烷的产生和氧化过程共同调控大气甲烷浓度,是全球碳循环不可分割的组成部分。对陆地生态系统甲烷产生和氧化过程的微生物机理研究进展进行了概要回顾和综述。主要内容包括:新型产甲烷古菌即第六和第七目产甲烷古菌和嗜冷嗜酸产甲烷古菌的发现;短链脂肪酸中间产物互营氧化过程与直接种间电子传递机制;新型甲烷氧化菌包括厌氧甲烷氧化菌和疣微菌属好氧甲烷氧化菌的发现;甲烷氧化菌生理生态与环境适应的新机制。这些研究进展显著拓展了人们对陆地生态系统甲烷产生和氧化机理的认识和理解。随着新一代土壤微生物研究技术的发展与应用,甲烷产生和氧化微生物研究领域将面临更多机遇和挑战,对未来发展趋势做了展望。 |
| [50] | . It is tempting to develop green energy biotechnology to supplement the depletion of fossil fuel resources and to reduce the greenhouse gas emissions. It has been recently demonstrated that paddy soil can be used to construct the sediment-type microbial fuel cells (MFCs). The mechanisms involved in electricity generation and its effects on methanogenesis, however, remain poorly understood. In the present experiment, we constructed paddy soil MFCs to evaluate the effect of MFC on CH 4 emission and to determine the bacterial and archaeal populations associated with MFC anodes. We found that electrical current in MFCs increased rapidly in three weeks, while only minor current was detected in MFCs without rice plants. Methane emission decreased in closed circuit MFCs compared with open circuit MFCs that did not have electricity output. Molecular approaches revealed that the upstream fermentation bacterial community was not significantly affected by MFCs. However, the relative abundances of Geobacteraceae increased markedly in MFCs; and concurrently the classical syntrophs including Syntrophaceae , Syntrophorhabdaceae , Syntrophobacteraceae and Syntrophomonadaceae increased. Among methanogenic archaea, the relative abundance of Methanosaetaceae increased significantly in closed circuit MFCs compared with open-circuit MFCs. Collectively, our study suggests that the activities of electron-transferring bacteria and archaea are significantly promoted in paddy soil MFCs. |
| [51] | . 耕地地力影响了化肥养分的利用效率,是调控养分利用率的基础途径。本文概述了耕地土壤障碍对养分利用的制约机制、耕地地力培育对养分利用的促进机制、提高养分资源利用效率的耕地培肥模式3个方面的研究进展。针对我国主要的耕地土壤–作物系统,提高化肥养分利用率需要解决4个地力调控方面的关键问题:地力与养分利用率关系及其时空变化规律、土壤障碍制约养分高效蓄积转化机制与消减原理、地力培肥促进根系–土壤–微生物互作提高养分耦合利用机制及调控途径、肥沃耕层构建与生物功能提升对养分蓄纳供应的协同驱动增效机制与调控理论。本文提出基于多时空尺度综合研究,建立稳定提升土壤功能–加速养分循环利用的"双核驱动"地力综合管理理论,在不同区域构建并应用化肥减施增效的耕地地力综合管理模式,实现耕地大面积均衡减施化肥的目标。 . 耕地地力影响了化肥养分的利用效率,是调控养分利用率的基础途径。本文概述了耕地土壤障碍对养分利用的制约机制、耕地地力培育对养分利用的促进机制、提高养分资源利用效率的耕地培肥模式3个方面的研究进展。针对我国主要的耕地土壤–作物系统,提高化肥养分利用率需要解决4个地力调控方面的关键问题:地力与养分利用率关系及其时空变化规律、土壤障碍制约养分高效蓄积转化机制与消减原理、地力培肥促进根系–土壤–微生物互作提高养分耦合利用机制及调控途径、肥沃耕层构建与生物功能提升对养分蓄纳供应的协同驱动增效机制与调控理论。本文提出基于多时空尺度综合研究,建立稳定提升土壤功能–加速养分循环利用的"双核驱动"地力综合管理理论,在不同区域构建并应用化肥减施增效的耕地地力综合管理模式,实现耕地大面积均衡减施化肥的目标。 |
| [52] | 综合自然地理学及相关的景观生态学是自然地理学的重要分支学科。本文综述了近年来综合自然地理学在学术和应用方面取得的重要进展,由3部分组成:(1)学科发展回顾;(2)近今主要进展,包括在基础研究理论与方法技术方面的学科进展和研究成果应用方面的贡献;(3)学科未来展望,包括机遇与挑战分析和重点研究领域。综合自然地理学的未来发展应注意以下方面:进一步促进更高层次的综合与集成,加强多学科间的交叉融合,共同探究地表系统复杂性问题及机制;进一步提高观测技术和模型模拟的水平,以解决空间与时间上更为复杂的生物地理过程和格局问题;进一步拓展应用领域,为国家资源、环境和社会经济的可持续发展提供科技支持。 . 综合自然地理学及相关的景观生态学是自然地理学的重要分支学科。本文综述了近年来综合自然地理学在学术和应用方面取得的重要进展,由3部分组成:(1)学科发展回顾;(2)近今主要进展,包括在基础研究理论与方法技术方面的学科进展和研究成果应用方面的贡献;(3)学科未来展望,包括机遇与挑战分析和重点研究领域。综合自然地理学的未来发展应注意以下方面:进一步促进更高层次的综合与集成,加强多学科间的交叉融合,共同探究地表系统复杂性问题及机制;进一步提高观测技术和模型模拟的水平,以解决空间与时间上更为复杂的生物地理过程和格局问题;进一步拓展应用领域,为国家资源、环境和社会经济的可持续发展提供科技支持。 |
| [53] | . |
| [54] | The carbon balance of terrestrial ecosystems is particularly sensitive to climatic changes in autumn and spring, with spring and autumn temperatures over northern latitudes having risen by about 1.1 degrees C and 0.8 degrees C, respectively, over the past two decades. A simultaneous greening trend has also been observed, characterized by a longer growing season and greater photosynthetic activity. These observations have led to speculation that spring and autumn warming could enhance carbon sequestration and extend the period of net carbon uptake in the future. Here we analyse interannual variations in atmospheric carbon dioxide concentration data and ecosystem carbon dioxide fluxes. We find that atmospheric records from the past 20 years show a trend towards an earlier autumn-to-winter carbon dioxide build-up, suggesting a shorter net carbon uptake period. This trend cannot be explained by changes in atmospheric transport alone and, together with the ecosystem flux data, suggest increasing carbon losses in autumn. We use a process-based terrestrial biosphere model and satellite vegetation greenness index observations to investigate further the observed seasonal response of northern ecosystems to autumnal warming. We find that both photosynthesis and respiration increase during autumn warming, but the increase in respiration is greater. In contrast, warming increases photosynthesis more than respiration in spring. Our simulations and observations indicate that northern terrestrial ecosystems may currently lose carbon dioxide in response to autumn warming, with a sensitivity of about 0.2 PgC degrees C(-1), offsetting 90% of the increased carbon dioxide uptake during spring. If future autumn warming occurs at a faster rate than in spring, the ability of northern ecosystems to sequester carbon may be diminished earlier than previously suggested. |
| [55] | |
| [56] | Monitoring changes in vegetation growth has been the subject of considerable research during the past several decades, because of the important role of vegetation in regulating the terrestrial carbon cycle and the climate system. In this study, we combined datasets of satellite-derived Normalized Difference Vegetation Index (NDVI) and climatic factors to analyze spatio-temporal patterns of changes in vegetation growth and their linkage with changes in temperature and precipitation in temperate and boreal regions of Eurasia (> 23.5°N) from 1982 to 2006. At the continental scale, although a statistically significant positive trend of average growing season NDVI is observed (0.5 × 10613 year611, P = 0.03) during the entire study period, there are two distinct periods with opposite trends in growing season NDVI. Growing season NDVI has first significantly increased from 1982 to 1997 (1.8 × 10613 year611, P < 0.001), and then decreased from 1997 to 2006 (611.3 × 10613 year611, P = 0.055). This reversal in the growing season NDVI trends over Eurasia are largely contributed by spring and summer NDVI changes. Both spring and summer NDVI significantly increased from 1982 to 1997 (2.1 × 10613 year611, P = 0.01; 1.6 × 10613 year611P < 0.001, respectively), but then decreased from 1997 to 2006, particularly summer NDVI which may be related to the remarkable decrease in summer precipitation (612.7 mm yr611, P = 0.009). Further spatial analyses supports the idea that the vegetation greening trend in spring and summer that occurred during the earlier study period 1982–1997 was either stalled or reversed during the following study period 1997–2006. But the turning point of vegetation NDVI is found to vary across different regions. |
| [57] | Urban heat island is among the most evident aspects of human impacts on the earth system. Here we assess the diurnal and seasonal variation of surface urban heat island intensity (SUHII) defined as the surface temperature difference between urban area and suburban area measured from the MODIS. Differences in SUHII are analyzed across 419 global big cities, and we assess several potential biophysical and socio-economic driving factors. Across the big cities, we show that the average annual daytime SUHII (1.5 1.2 C) is higher than the annual nighttime SUHII (1.1 0.5 C) (P < 0.001). But no correlation is found between daytime and nighttime SUHII across big cities (P = 0.84), suggesting different driving mechanisms between day and night. The distribution of nighttime SUHII correlates positively with the difference in albedo and nighttime light between urban area and suburban area, while the distribution of daytime SUHII correlates negatively across cities with the difference of vegetation cover and activity between urban and suburban areas. Our results emphasize the key role of vegetation feedbacks in attenuating SUHII of big cities during the day, in particular during the growing season, further highlighting that increasing urban vegetation cover could be one effective way to mitigate the urban heat island effect. |
| [58] | Abstract China has the largest afforested area in the world (6562 million hectares in 2008), and these forests are carbon sinks. The climatic effect of these new forests depends on how radiant and turbulent energy fluxes over these plantations modify surface temperature. For instance, a lower albedo may cause warming, which negates the climatic benefits of carbon sequestration. Here, we used satellite measurements of land surface temperature (LST) from planted forests and adjacent grasslands or croplands in China to understand how afforestation affects LST. Afforestation is found to decrease daytime LST by about 1.1 ± 0.5 °C (mean ± 1 SD) and to increase nighttime LST by about 0.2 ± 0.5 °C, on average. The observed daytime cooling is a result of increased evapotranspiration. The nighttime warming is found to increase with latitude and decrease with average rainfall. Afforestation in dry regions therefore leads to net warming, as daytime cooling is offset by nighttime warming. Thus, it is necessary to carefully consider where to plant trees to realize potential climatic benefits in future afforestation projects. |
| [59] | The biophysical effects of forests on climate have been extensively studied with climate models. However, models cannot accurately reproduce local climate effects due to their coarse spatial resolution and uncertainties, and field observations are valuable but often insufficient due to their limited coverage. Here we present new evidence acquired from global satellite data to analyse the biophysical effects of forests on local climate. Results show that tropical forests have a strong cooling effect throughout the year; temperate forests show moderate cooling in summer and moderate warming in winter with net cooling annually; and boreal forests have strong warming in winter and moderate cooling in summer with net warming annually. The spatiotemporal cooling or warming effects are mainly driven by the two competing biophysical effects, evapotranspiration and albedo, which in turn are strongly influenced by rainfall and snow. Implications of our satellite-based study could be useful for informing local forestry policies. |
| [60] | Soil temperature (Ts) change is a key indicator of the dynamics of permafrost. On seasonal and interannual timescales, the variability of Ts determines the active-layer depth, which regulates hydrological soil properties and biogeochemical processes. On the multi-decadal scale, increasing Ts not only drives permafrost thaw/retreat but can also trigger and accelerate the decomposition of soil organic carbon. The magnitude of permafrost carbon feedbacks is thus closely linked to the rate of change of soil thermal regimes. In this study, we used nine process-based ecosystem models with permafrost processes, all forced by different observation-based climate forcing during the period 1960–2000, to characterize the warming rate of Ts in permafrost regions. There is a large spread of Ts trends at 2062cm depth across the models, with trend values ranging from 0.01062±620.003 to 0.03162±620.00562°C62yr611. Most models show smaller increase in Ts with increasing depth. Air temperature (Tsub>a) and longwave downward radiation (LWDR) are the main drivers of Ts trends, but their relative contributions differ amongst the models. Different trends of LWDR used in the forcing of models can explain 6162% of their differences in Ts trends, while trends of Ta only explain 562% of the differences in Ts trends. Uncertain climate forcing contributes a larger uncertainty in Ts trends (0.02162±620.00862°C62yr611, mean62±62standard deviation) than the uncertainty of model structure (0.01262±620.00162°C62yr611), diagnosed from the range of response between different models, normalized to the same forcing. In addition, the loss rate of near-surface permafrost area, defined as total area where the maximum seasonal active-layer thickness (ALT) is less than 362m loss rate, is found to be significantly correlated with the magnitude of the trends of Ts at 162m depth across the models (R65=65610.85, P65=650.003), but not with the initial total near-surface permafrost area (R65=65610.30, P65=650.438). The sensitivity of the total boreal near-surface permafrost area to Ts at 162m is estimated to be of 612.8062±620.6762million62km262°C611. Finally, by using two long-term LWDR data sets and relationships between trends of LWDR and Ts across models, we infer an observation-constrained total boreal near-surface permafrost area decrease comprising between 3962±62146265×6562103 and 7562±62146265×656210362km262yr611 from 1960 to 2000. This corresponds to 9–1862% degradation of the current permafrost area. |
| [61] | Abstract The carbon emissions from land-use and land-cover change (ELUC) are an important anthropogenic component of the global carbon budget. Yet, these emissions have a large uncertainty. Uncertainty in historical land-use and land-cover change (LULCC) maps and their implementation in global vegetation models is one of the key sources of the spread of ELUC calculated by global vegetation models. In this study, we used the ORCHIDEE terrestrial biosphere model to investigate how the different transition rules to define the priority of conversion from natural vegetation to agricultural land affect the historical reconstruction of plant functional types (PFTs) and ELUC. First, we reconstructed ten sets of historical PFT maps using different transition rules and two methods. Then, we calculated ELUC from these ten different historical PFT maps and an additional published PFT reconstruction, using the difference between two sets of simulations (with and without LULCC). The total area of forest loss is highly correlated with the total simulated ELUC (R2 = 0.83, P < 0.001) across the reconstructed PFT maps, which indicates that the choice of transition rules is a critical (and often overlooked) decision affecting the simulated ELUC. In addition to the choice of a transition rule, the initial land-cover map and the reconstruction method for the reconstruction of historical PFT maps have an important impact on the resultant estimates of ELUC. |
| [62] | Processes that describe the distribution of vegetation and ecosystem succession after disturbance are an important component of dynamic global vegetation models (DGVMs). The vegetation dynamics module (ORC-VD) within the process-based ecosystem model ORCHIDEE (Organizing Carbon and Hydrology in Dynamic Ecosystems) has not been updated and evaluated since many years and does not match the progress in modeling the rest of the physical and biogeochemical processes. Therefore, ORC-VD is known to produce unrealistic results. This study presents a new parameterization of ORC-VD for mid-to-high latitude regions in the Northern Hemisphere, including processes that influence the existence, mortality and competition between tree functional types. A new set of metrics is also proposed to quantify the performance of ORC-VD, using up to five different datasets of satellite land cover, forest biomass from remote sensing and inventories, a data-driven estimate of gross primary productivity (GPP) and two gridded datasets of soil organic carbon content. The scoring of ORC-VD derived from these metrics integrates uncertainties in the observational datasets. This multi-dataset evaluation framework is a generic method that could be applied to the evaluation of other DGVM models. The results of the original ORC-VD published in 2005 for mid-to-high latitudes and of the new parameterization are evaluated against the above-described datasets. Significant improvements were found in the modeling of the distribution of tree functional types north of 40掳 N. Three additional sensitivity runs were carried out to separate the impact of different processes or drivers on simulated vegetation distribution, including soil freezing which limits net primary production through soil moisture availability in the root zone, elevated COsub2/sub concentration since 1850, and the return frequency of cold climate extremes causing tree mortality during the spin-up phase of the model. |
| [63] | Substantial quantities of organic carbon (OC) are stored in the thick, ice-rich, and organic-rich sediments called yedoma deposits, distributed in eastern Siberia and Alaska today. Quantifying yedoma carbon stocks during the glacial period is important for understanding how much carbon could have been decomposed during the last deglaciation. Yet processes that yield the formation of thick frozen OC in yedoma deposits are missing in global carbon cycle models. Here we incorporate sedimentation parameterizations into the Organizing Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE-MICT) land surface model, which leads to reasonable results in OC vertical distribution and regional budgets, compared with site-specific observations and inventories for today's nondegraded yedoma region. Simulated total soil OC stock for the northern permafrost region during the Last Glacial Maximum (LGM) is 1536–159265Pg65C, of which 390–44665Pg65C is within today's yedoma region. This result is an underestimation since we did not account for the potentially much larger yedoma area during the LGM than the present day. |
| [64] | 研究目的：综述喀斯特地区在土地利用／覆被变化研究的进展和不足，展望未来研究方向。研究方法：文献综述法。研究结论：（1）中国西南喀斯特地区土地利用，覆被动态变化研究较少，是LUCC研究的薄弱区域。（2）喀斯特地区土地利用／覆被格局和过程变化的研究刚起步，需要深入研究以解释其变化过程和空间差异。（3）在驱动力方面，对城市化、政策、制度以及全球化等因素及它们间如何共同作用于LUCC涉及较少。（4）如何建立具有良好空间表达能力并能反演LUCC历史过程和预测未来变化的模型。有待深入研究。（5）LUCC对区域生态服务功能和人类福利的影响以及人类社会对此如何响应的研究将是喀斯特地区LUCC研究的一个新的方向。 . 研究目的：综述喀斯特地区在土地利用／覆被变化研究的进展和不足，展望未来研究方向。研究方法：文献综述法。研究结论：（1）中国西南喀斯特地区土地利用，覆被动态变化研究较少，是LUCC研究的薄弱区域。（2）喀斯特地区土地利用／覆被格局和过程变化的研究刚起步，需要深入研究以解释其变化过程和空间差异。（3）在驱动力方面，对城市化、政策、制度以及全球化等因素及它们间如何共同作用于LUCC涉及较少。（4）如何建立具有良好空间表达能力并能反演LUCC历史过程和预测未来变化的模型。有待深入研究。（5）LUCC对区域生态服务功能和人类福利的影响以及人类社会对此如何响应的研究将是喀斯特地区LUCC研究的一个新的方向。 |
| [65] | LUCC是当前国际全球变化研究的前沿和热点领域,喀斯特生态脆弱区的土地利用/覆被变化是国际LUCC研究中的薄弱环节.以贵州中部的典型喀斯特流域--猫跳河流域为例,通过详实的地面调查,以1973年的Landsat-MSS影像、1990年和2002年的Landsat-TM影像为数据源,在RS、GIS、GPS为核心的"三S"集成技术支撑下,应用单一土地利用动态度、单一土地利用转入率和转出率、综合土地利用动态度、土地利用度以及土地覆被变化空间指数等指标,定量研究了该流域在过去30 a间的土地利用/覆被的变化特征.研究表明:(1)研究区的土地覆被类型主要以耕地、灌草地、灌木林以及有林地为主;(2)1970年代以来,土地利用/覆被变化剧烈,各地类之间的变化幅度存在较大差别,水田、灌木林、其他林地、灌草地等地类先减后增,旱地和裸岩地先增后减,有林地、水域、城镇建设用地、农村居民点、交通工矿用地等持续增加;(3)1973～1990年的土地利用动态度和土地利用度均比1990～2002年大,前一时期的裸岩地明显增加,土地利用具有明显的不可持续性,进入1990年后,裸岩地缩减,流域生态环境质量趋于好转;(4)伴随着分布面积在平面空间上的张缩,各地类的平均分布高程和坡度在垂直方向上也出现了相应的变化. . LUCC是当前国际全球变化研究的前沿和热点领域,喀斯特生态脆弱区的土地利用/覆被变化是国际LUCC研究中的薄弱环节.以贵州中部的典型喀斯特流域--猫跳河流域为例,通过详实的地面调查,以1973年的Landsat-MSS影像、1990年和2002年的Landsat-TM影像为数据源,在RS、GIS、GPS为核心的"三S"集成技术支撑下,应用单一土地利用动态度、单一土地利用转入率和转出率、综合土地利用动态度、土地利用度以及土地覆被变化空间指数等指标,定量研究了该流域在过去30 a间的土地利用/覆被的变化特征.研究表明:(1)研究区的土地覆被类型主要以耕地、灌草地、灌木林以及有林地为主;(2)1970年代以来,土地利用/覆被变化剧烈,各地类之间的变化幅度存在较大差别,水田、灌木林、其他林地、灌草地等地类先减后增,旱地和裸岩地先增后减,有林地、水域、城镇建设用地、农村居民点、交通工矿用地等持续增加;(3)1973～1990年的土地利用动态度和土地利用度均比1990～2002年大,前一时期的裸岩地明显增加,土地利用具有明显的不可持续性,进入1990年后,裸岩地缩减,流域生态环境质量趋于好转;(4)伴随着分布面积在平面空间上的张缩,各地类的平均分布高程和坡度在垂直方向上也出现了相应的变化. |
| [66] | 土壤侵蚀与土地利用关系密切,但在不同地区表现不一.喀斯特山区由于土壤侵蚀的特殊性,不能直接沿用其它地区已有的相关成果.选取贵州省西南地区喀斯特发育典型的一个小流域为案例,从土地利用的类型、坡度格局和高度格局三方面与土壤侵蚀的关系进行了探讨,研究发现喀斯特山区土地利用/覆被与土壤侵蚀之间的关系与其它地区不尽相同,表现在:喀斯特山区各土地利用类型土壤侵蚀发生率依次为:草地>林地>旱地>难利用地>建筑用地>水田.除水田外,植被覆盖度对土壤侵蚀的控制存在临界值:20%～60%.土壤侵蚀强度与植被覆盖度近似呈正比.土地利用在坡度和海拔上的分布格局对土壤侵蚀的控制同样存在临界值,其中临界坡度在15～25°之间,临界海拔在1 485～1 505 m之间. . 土壤侵蚀与土地利用关系密切,但在不同地区表现不一.喀斯特山区由于土壤侵蚀的特殊性,不能直接沿用其它地区已有的相关成果.选取贵州省西南地区喀斯特发育典型的一个小流域为案例,从土地利用的类型、坡度格局和高度格局三方面与土壤侵蚀的关系进行了探讨,研究发现喀斯特山区土地利用/覆被与土壤侵蚀之间的关系与其它地区不尽相同,表现在:喀斯特山区各土地利用类型土壤侵蚀发生率依次为:草地>林地>旱地>难利用地>建筑用地>水田.除水田外,植被覆盖度对土壤侵蚀的控制存在临界值:20%～60%.土壤侵蚀强度与植被覆盖度近似呈正比.土地利用在坡度和海拔上的分布格局对土壤侵蚀的控制同样存在临界值,其中临界坡度在15～25°之间,临界海拔在1 485～1 505 m之间. |
| [67] | <p>“尺度”是认识世界和管理世界的一个重要视角，多尺度之间的相互关联是当前重要的学术前沿论题。尺度关联研究面临的主要问题是：①对scaling的理解不能局限于“尺度转换”或“尺度耦合”，而需要对不同尺度的多种复杂关系（“连通性”）有综合的认识；②要正确认识尺度综合的目标，据此明确综合什么，如何综合；③解决尺度综合的方法不能仅从数学模型着手。本文以贵州喀斯特高原土地系统变化为研究案例，设计一个对贵州省域、乌江流域、猫跳河流域和若干小流域等多空间尺度土地变化进行综合的研究方案，力图为解决上述问题作出贡献。该案例研究针对土地管理可持续性决策多尺度协调的实际需求，以不同尺度之间“连通性”的判定为基础，重新厘定尺度综合在土地变化科学中的意义和内涵；以定性和定量相结合的途径，建立尺度综合的方法体系，包括基于尺度综合目标的土地变化及其驱动力和效应多尺度表征与数据协调方法，各尺度土地变化及其驱动力和效应之间“连通性”的发现与论证，土地变化及其驱动力和效应的多尺度综合集成；提供喀斯特地区土地变化格局、过程及其驱动力和效应的尺度综合研究案例，提供省域、省内大流域、中流域、小流域土地管理可持续性决策多尺度协调的依据和参数标准。</p> . <p>“尺度”是认识世界和管理世界的一个重要视角，多尺度之间的相互关联是当前重要的学术前沿论题。尺度关联研究面临的主要问题是：①对scaling的理解不能局限于“尺度转换”或“尺度耦合”，而需要对不同尺度的多种复杂关系（“连通性”）有综合的认识；②要正确认识尺度综合的目标，据此明确综合什么，如何综合；③解决尺度综合的方法不能仅从数学模型着手。本文以贵州喀斯特高原土地系统变化为研究案例，设计一个对贵州省域、乌江流域、猫跳河流域和若干小流域等多空间尺度土地变化进行综合的研究方案，力图为解决上述问题作出贡献。该案例研究针对土地管理可持续性决策多尺度协调的实际需求，以不同尺度之间“连通性”的判定为基础，重新厘定尺度综合在土地变化科学中的意义和内涵；以定性和定量相结合的途径，建立尺度综合的方法体系，包括基于尺度综合目标的土地变化及其驱动力和效应多尺度表征与数据协调方法，各尺度土地变化及其驱动力和效应之间“连通性”的发现与论证，土地变化及其驱动力和效应的多尺度综合集成；提供喀斯特地区土地变化格局、过程及其驱动力和效应的尺度综合研究案例，提供省域、省内大流域、中流域、小流域土地管理可持续性决策多尺度协调的依据和参数标准。</p> |
| [68] | |
| [69] | Shibanqiao Reservoir (25°56′56.5′′02N, 105°26′44.5′′02E and 65140002m02a.s.l.), southwest Guizhou Plateau, SW China, was built in 1958. It lies in an area of sub-tropical monsoon humid climate in a carbonate-rock-dominated catchment of 602km 2 . Two sediment cores (24 and 2302cm long) were retrieved from the reservoir, and four soil profiles were sampled in the catchment. Mineral magnetism was measured on all sediment and soil samples. Soil and sediment magnetic measurements together with analyses of sediment 137 Cs activity, particle-size, TOC, and C/N revealed changes in soil erosion between 1960 and 2002. During some phases, erosion (probably as splashing and/or sheeting) was relatively low and tended to take place only in the topsoil as indicated by high ARM/SIRM of the sediments. During other phases, erosion (probably as rilling and/or initial gullying) was relatively intense and thus disturbed the deeper soils, as expressed by high IRM 61100mT /SIRM. Most of the changes in relative intensity of erosion can be ascribed to fluctuations in precipitation. Changes in land use/land cover or human activities may account, in part, for changes in soil erosion inferred for four more roughly identified periods. |
| [70] | |
| [71] | 1IntroductionHumanactivities,especiallylanduse,havechangedphysicalgeographicalenvironmentgreatly,thedirectresultofwhichisthechangesoflandcover(TurnerIIetal.,1990).Atpresent,manyproblemsfacingpeoplearerelatedwithlanduse/landcoverchanges(LUCC).StudyonLUCCe |
| [72] | 利用1995和2000年 Landsat 5、4、3、2(RGB)波段合成影像解译结果,采用中国科学院资源环境数据库中的中国1:10万土地资源利用分类系统,对河西走廊中段的张掖绿洲的土地 利用/覆被变化(LUCC)进行了研究。并运用典型相关分析方法对张掖绿洲LUCC及其影响因子进行了统计分析。诊断出各影响因子对该区LUCC的贡献作 用大小,同时运用典型相关系数和冗余度分析,检验了分析结果。 . 利用1995和2000年 Landsat 5、4、3、2(RGB)波段合成影像解译结果,采用中国科学院资源环境数据库中的中国1:10万土地资源利用分类系统,对河西走廊中段的张掖绿洲的土地 利用/覆被变化(LUCC)进行了研究。并运用典型相关分析方法对张掖绿洲LUCC及其影响因子进行了统计分析。诊断出各影响因子对该区LUCC的贡献作 用大小,同时运用典型相关系数和冗余度分析,检验了分析结果。 |
| [73] | 利用1995和2000年两个时期的Landsat5的4、3、2(RGB)波段合成影像解译结果, 采用中国科学院资源环境数据库中的全国1∶10万土地资源利用分类系统, 对河西走廊近5年来景观动态变化的驱动力进行了研究。为判断出区域景观类型变化趋势, 研究从区域背景变化格局分析入手, 对区域内部变化斑块的几何特征、变化数目及与GDP的对应关系进行统计分析, 得出河西走廊景观变化和社会经济发展具有较高的时空相关性, 进而用典型相关分析方法来推导了斑块变化的内在社会经济驱动力。结果表明: ①引起耕地斑块转出的因子是农牧投入-产出的增加, 水域斑块转出直接与渔业产值有关, 未利用地斑块转出与农业机械的使用和播种面积增加相关, 林地斑块转出的因子是农业产量和工业产值的变化, 城建斑块转出与农民收入低、城市化水平有关; 城镇用地斑块转入是工业产值增加的结果, 草地、林地斑块转入的因子是农业投入的增加, 耕地斑块转入与农民收入增加有关, 水域斑块转入直接因子是渔业产值增加。②结合驱动力类型分析, 耕地面积变化主要是最优经济福利及粮食安全驱动作用下的结果; 草地、林地被开垦, 耕地增加主要是生存型经济福利驱动的结果, 最优经济福利驱动有时也起到一定的作用; 城镇用地增加主要是最优经济福利驱动的结果; 在生态环境脆弱及其 . 利用1995和2000年两个时期的Landsat5的4、3、2(RGB)波段合成影像解译结果, 采用中国科学院资源环境数据库中的全国1∶10万土地资源利用分类系统, 对河西走廊近5年来景观动态变化的驱动力进行了研究。为判断出区域景观类型变化趋势, 研究从区域背景变化格局分析入手, 对区域内部变化斑块的几何特征、变化数目及与GDP的对应关系进行统计分析, 得出河西走廊景观变化和社会经济发展具有较高的时空相关性, 进而用典型相关分析方法来推导了斑块变化的内在社会经济驱动力。结果表明: ①引起耕地斑块转出的因子是农牧投入-产出的增加, 水域斑块转出直接与渔业产值有关, 未利用地斑块转出与农业机械的使用和播种面积增加相关, 林地斑块转出的因子是农业产量和工业产值的变化, 城建斑块转出与农民收入低、城市化水平有关; 城镇用地斑块转入是工业产值增加的结果, 草地、林地斑块转入的因子是农业投入的增加, 耕地斑块转入与农民收入增加有关, 水域斑块转入直接因子是渔业产值增加。②结合驱动力类型分析, 耕地面积变化主要是最优经济福利及粮食安全驱动作用下的结果; 草地、林地被开垦, 耕地增加主要是生存型经济福利驱动的结果, 最优经济福利驱动有时也起到一定的作用; 城镇用地增加主要是最优经济福利驱动的结果; 在生态环境脆弱及其 |
| [74] | 土地利用变化的驱动力受多时空尺度影响,存在明显的尺度依赖性.本文选择地处毛乌素沙地腹地的乌审旗,基于1978、1988、2000、2008年土地利用数据、社会经济数据及农牧户调查数据,采用Logistic回归模型和参与式农村评估方法进行县域尺度的土地利用变化驱动力的多尺度研究.结果表明:在宏观尺度上土地利用变化受到地形、水文、交通、居民点等地理环境因素和人口、经济发展和政策制度等社会经济因素的驱动;在微观尺度上,农牧户个体生计策略则发挥了较为显著的作用,且不同类型农牧户特性决定了土地利用模式的选择既受到资源条件的限制,又要受到社会文化、市场环境和政府政策的影响.研究结果可为区域土地持续利用提供借鉴. . 土地利用变化的驱动力受多时空尺度影响,存在明显的尺度依赖性.本文选择地处毛乌素沙地腹地的乌审旗,基于1978、1988、2000、2008年土地利用数据、社会经济数据及农牧户调查数据,采用Logistic回归模型和参与式农村评估方法进行县域尺度的土地利用变化驱动力的多尺度研究.结果表明:在宏观尺度上土地利用变化受到地形、水文、交通、居民点等地理环境因素和人口、经济发展和政策制度等社会经济因素的驱动;在微观尺度上,农牧户个体生计策略则发挥了较为显著的作用,且不同类型农牧户特性决定了土地利用模式的选择既受到资源条件的限制,又要受到社会文化、市场环境和政府政策的影响.研究结果可为区域土地持续利用提供借鉴. |
| [75] | <p>人类的开发活动是造成土地覆盖和景观格局变化的主要原因.村域尺度上高强度的人类开发活动对土地覆盖及景观格局演变的影响规律研究尚不多见.本研究采用2009年的GeoEye-1数据和2014年的WorldView3数据,利用ArcGIS和ENVI,基于面向对象和人机交互的方法解译影像,应用土地利用转移矩阵和景观指数定量研究大理市海东镇低丘缓坡山区改造过程中的土地覆盖变化和景观格局演变.结果表明: 2009年主要土地覆盖类型是林地、水田和旱地,占总面积的82.8%,2014年林地、推平未建地和水田占总面积的70.9%;研究期间,土地利用变化主要由林地、水田和旱地向推平未建地、建设用地转移,尤其是2014年推平未建地面积达531.57 hm<sup>2</sup>,其中,来自林地、旱地和水田的面积分别占42.8%、21.7%和14.2%.景观空间格局演变表现为斑块数量和密度增加,平均斑块面积变小;边缘指数和形状指数增加,斑块形状更加复杂;斑块破碎化,整体构成更加多样化.</p> . <p>人类的开发活动是造成土地覆盖和景观格局变化的主要原因.村域尺度上高强度的人类开发活动对土地覆盖及景观格局演变的影响规律研究尚不多见.本研究采用2009年的GeoEye-1数据和2014年的WorldView3数据,利用ArcGIS和ENVI,基于面向对象和人机交互的方法解译影像,应用土地利用转移矩阵和景观指数定量研究大理市海东镇低丘缓坡山区改造过程中的土地覆盖变化和景观格局演变.结果表明: 2009年主要土地覆盖类型是林地、水田和旱地,占总面积的82.8%,2014年林地、推平未建地和水田占总面积的70.9%;研究期间,土地利用变化主要由林地、水田和旱地向推平未建地、建设用地转移,尤其是2014年推平未建地面积达531.57 hm<sup>2</sup>,其中,来自林地、旱地和水田的面积分别占42.8%、21.7%和14.2%.景观空间格局演变表现为斑块数量和密度增加,平均斑块面积变小;边缘指数和形状指数增加,斑块形状更加复杂;斑块破碎化,整体构成更加多样化.</p> |
| [76] | Abstract Ecological restoration can mitigate human disturbance to the natural environment and restore ecosystem functions. China's Grain-for-Green Programme (GFGP) has been widely adopted in the last 15years and exerted significant impact on land-use and ecosystem services. North-western Yunnan is one of the key areas of GFGP implementation in the upper Yangtze River. Promotion of ecosystem services in this region is of great importance to the ecological sustainability of Yangtze River watershed. In this study, remote sensing and modelling techniques are applied to analyse the impact of GFGP on ecosystem services. Results show that the transformation from non-irrigated farmland to forestland could potentially improve soil conservation by 24.89%. Soil conservation of restored forest was 78.17% of retained forest while net primary production (NPP) already reached 88.65%, which suggested different recovery rates of NPP and soil conservation. Increasing extent of GFGP implementation improved soil conservation but decreased NPP and water yield at sub-watershed scale, which revealed trade-offs between ecosystem services under ecological restoration. Future ecosystem management and GFGP policy-making should consider trade-offs of ecosystem services in order to achieve sustainable provision of ecosystem services. Copyright 2016 Elsevier B.V. All rights reserved. |
| [77] | |
| [78] | The impact of land-use change on flood is examined based on an approach composed of three parts: (1) reproduction of spatially explicit land use/cover change (LUCC); (2) application of a 2D hydraulic modelling for flood simulation; (3) demonstration of results for Beijing, a predominantly urbanized and deforestation catchment during last decades.The approach is applied to a flood prone area in Beijing. The results show that 8% and 21% of the study area experienced LUCC during 1991-2001 and 2001-2011 respectively and the change greatly influenced flood characteristics, i.e. (1) the flood zone is doubled during 1991-2001 and about fourfold during 2001-2011; (2) the water depth is increased for most of the study area and; (3) the flow velocity becomes faster. It points out that flooding still exists within Beijing and is even more dangerous than 40 years ago. The results suggest that actual land use pattern and existing flood protection works should be re-evaluated regarding the change in flood characteristics due to LUCC and their trade-offs should be also identified and, if possible, predicted while planning for urban development and flood protection. This is especially true for most cities in China and other developing countries under rapid urban development. |
| [79] | |
| [80] | In this study, a mix inexact-quadratic fuzzy water resources management model of floodplain (IQT-WMMF) has developed, through incorporating techniques of credibility-constrained programming (CP), two-stage programming (TP), interval-parameter programming (IPP) and quadratic programming (QP) within a general framework for limited data availability. The IQT-WMMF can provide an effective linkage between system benefit and the associated economic penalty attributed to the violation of the pre-regulated water target under limited data availabilities expressed probabilistic distributions and interval values; meanwhile, imprecise and no-linear economic data would be resolved. The developed method is applied to a real case of planning water resources in the Dahuangbaowa floodplain, China, with the aim to develop a sustainable water resources management in the study region. A number of scenarios with wet land expansion strategies under various credibility levels are analyzed, implying that different policies can lead to varied water-allocation patterns, system benefits, and system-failure risks. The results discover that water deficits and flood damages have brought negative effects on economic development synchronously, which need to effective plans to reduce losses of shortages and floods for achieving higher system benefits. Tradeoffs between economic benefit and system-failure risk can support generating an increased robustness in risk control for water resources allocation under uncertainties, which is beneficial to adjust the current water-allocation sustainably. |
| [81] | In this study, a developed fuzzy approximation mixed stochastic approach (DFAS) is proposed for a regional wetland ecosystem (RWE) management under uncertainty. DFAS can handle traditional objective non-determinacy (caused by natural element) and anthropogenic uncertainty (caused by artificial factor) expressed as probability distribution and fuzzy set in objective function or constraint; it also extend to reflect compromise of risk attitude/preference of the decision maker in decision-making process through introducing rough set theory (RST) and measure Me. The proposed approach can be applied to a practical RWE management of Yongnianwa wetland, located in north of China, where the natural ecosystem has been suffered severe degradation induced by disharmonious developing speeds between human activities and environment. Results of ecological effects of wetland ecosystem, water allocation patterns, pollution-mitigation schemes, and system benefit analysis can be acquired. The results indicate that wetland ecosystem can produce a numbers of positive effects to the pollution control and environmental protection, where the total excess pollution discharges (concluding TN, TP and BOD) would reduce 202 and 242 tone (LAV and UAV) at highest. Meanwhile, it finds that wetland system method deemed as an effective/appropriate technology can remove 67%, 72% and 88% TN, TP and BOD from wastewater, where water quality standard of effluent would be II, II and III for TN, TP and BOD at best. However, competitive relationships between water consumption from human activity and wetland protection can facilitate decision makers adjusting current water-environment policies with a more efficient/sustainable manner. Meanwhile, tradeoffs between economic benefit and system-failure risk under optimistic/pessimistic option can support generating a robust plan associated with risk control for RWE under uncertainties. All of these detections can avail local decision makers to generate a plan integrating socio-economic development and eco-environmental protection sustainably. |
| [82] | This paper presents a case study of the Yellow River Delta in China, to trace land use and land cover changes during the past 20 years, with an emphasis on land quality changes. Three sets of data are used in this case study: remote sensing data derived from satellite images; crop yield data from statistics; and soil data collected by the researchers in the field. Our study reveals that at the regional scale, LUCC has taken place in a positive direction: vegetation cover has been expanding and crop yields per hectare have been on rise. However, while the overall eco-environment has improved, the improvement is uneven across the Delta region. At local levels, some areas show signs of increased salinization and declining organic content. Both natural forces and human activities are responsible for the LUCC, but human activities play a more important role. While some impacts of human activities are positive, the damages are often long-lasting and irreversible. We also conclude that it is necessary to use both macro data (such as remote sensing data) and micro data (data collected in the field) to study land quality change. The former are efficient in examining land quality changes at the regional scale, the latter can serve to verify ground patterns revealed from macro data and help to identify local variations, so as to get a comprehensive understanding of LUCC and promote sustainable land use and land management. |
| [83] | Research on land-use dynamics in coastal zones is important to environmental protection and regional sustainable development. The area involved in this study is the coastal zone of Bohai Bay, a new pole of economic growth in China. Landsat images from 1979, 1989, 1999, and 2008 are used to create land-use maps with seven first-class and 18 second-class types. A comprehensive approach, including a multidimensional transition matrix, land-use dynamic degree, and dynamic zoning based on an artificial neural network, is applied to investigate the evolution and spatial differentiation of land-use dynamics. Widespread changes in land use have occurred in the study area and accelerated between 1979 and 2008. Settlement and transportation land (i.e., land use for transportation) increased rapidly, while cultivated land and unused land suffered a noteworthy loss. These results reveal two key socioeconomic processes: urbanization and land reclamation from the sea. In this study, 20 primary land-use dynamics are calculated, and the study area is divided into 12 zones. According to the zoning map, there are three noteworthy transitions: unused land to saltwater body (primarily near the shore); unused land to transportation land (centered in the Tianjin New Port and Caofeidian Port); and cultivated land to settlement (mainly occurring in the northern and western parts of the study area). Urbanization, industrialization, land reclamation from the sea, port development, policies, and the structural adjustment of the primary industry all play a vital role in the land-use changes. Such changes should receive more attention from local authorities, who are expected to take immediate action to mitigate the impacts on the environment and implement land-use planning to achieve regionally sustainable development. |
| [84] | |
| [85] | . |
| [86] | To a large extent, tourism development triggers an economic boost in certain regions. However, given its complex and dynamic forms of land use, tourism development also causes changes to land-use demands and patterns in tourist regions, which directly and indirectly interfere with local environments. The development of tourist regions must achieve a series of trade-offs to meet sustainability goals. This paper discusses the effects of tourism on land-use change and how land regulation policies integrate tourism development with land use. We employed a system dynamic-cellular automata hybrid model using the Lijiang River Basin as an example to translate tourism-affected land dynamics into spatial distributions and project their likely future changes under various development scenarios. We determined three major outcomes. (1) Tourism development causes a quantitatively increasing demand for construction land. With effective spatial regulations, the expansion of construction land does not necessarily suggest the loss of eco-land; rather, land-use pressures accordingly shift to cropland. Under these circumstances, land regulation policies help to balance land demand and optimize land-use patterns. (2) Tourism development causes a continuous spatial interference with landscapes. Land regulation policies have the positive and active effect of ignoring this interference rather than counteracting it. (3) The strict implementation of land regulation policies does not necessarily improve land-use patterns. Flexible policies achieve a better balanced land-use pattern than a combination of individual strict policies. However, the former cannot reduce as much vulnerability as the latter. Hence, policy assembly represents a trade-off with regards to balancing land demands, and it should vary based on regional land-use patterns and targets. |
| [87] | 建模和情景分析是土地利用变化研究的核心内容。选择旅游业高速发展的漓江流域为研究区,利用基于邻域相关构建空间权重的Auto-logistic模型代替传统的Logistic回归,构建CLUE-S模型,对研究区2020年土地利用格局进行多情景模拟,并通过景观格局指数对比分析不同发展情景下的景观格局特征。结果表明:①利用邻域相关构建空间权重的Auto-logistic模型在预测土地空间分布概率方面较传统的Logistic模型具有更好的预测能力;②建设用地和草地高度破碎化、水域面积不稳定是漓江流域景观脆弱性的主要来源;③旅游地发展需要稳定、多样的景观格局。一方面要合理控制人为活动主导的用地类型对景观格局的冲击,另一方面应兼顾景观多样性,实现用地在社会经济和生态环境之间的协调。 . 建模和情景分析是土地利用变化研究的核心内容。选择旅游业高速发展的漓江流域为研究区,利用基于邻域相关构建空间权重的Auto-logistic模型代替传统的Logistic回归,构建CLUE-S模型,对研究区2020年土地利用格局进行多情景模拟,并通过景观格局指数对比分析不同发展情景下的景观格局特征。结果表明:①利用邻域相关构建空间权重的Auto-logistic模型在预测土地空间分布概率方面较传统的Logistic模型具有更好的预测能力;②建设用地和草地高度破碎化、水域面积不稳定是漓江流域景观脆弱性的主要来源;③旅游地发展需要稳定、多样的景观格局。一方面要合理控制人为活动主导的用地类型对景观格局的冲击,另一方面应兼顾景观多样性,实现用地在社会经济和生态环境之间的协调。 |
| [88] | Land use systems are complex adaptive systems, and they are characterized by emergence, nonlinearity, feedbacks, self organization, path dependence, adaptation, and multiple-scale characteristics. Land use/cover change has been recognized as one of the major drivers of global environmental change. This paper presents a coupled Cellular Automata (CA) and Radial Basis Function Neural (RBFN) Network model, which combines Geographic Information Systems (GIS) to contribute to the understanding of the complex land use/cover change process. In this model, GIS analysis is used to generate spatial drivers of land use/cover changes, and RBFN is trained to extract model parameters. Through the RBFN-CA model, the conversion probabilities of each cell from its initial land use state to the target type can be generated automatically. Future land use/cover scenarios are projected by using generated parameters in the model training process. This RBFN-CA model is tested based on the comparison of model output and the real data. A BPN-CA model is also built and compared with the RBFN-CA model by using a variety of calibration metrics, including confusion matrix, figure of merit, and landscape metrics. Both the location and landscape metrics based assessment for model simulation indicate that the RBFN-CA model performs better than the BPN-CA model for simulating land use changes in the study area. Therefore the RBFN-CA model is capable of simulating multiple classes of land use/cover changes and can be used as a useful communication environment for stakeholders involved in land use decision-making. |
| [89] | The effectiveness of landscape metrics in quantifying spatial patterns is fundamental to metrics assessment. Setting 36 simulated landscapes as sample space and focusing on 23 widely used landscape metrics, their effectiveness in quantifying the complexity of such spatial pattern components as number of patch types, area ratio of patch types and patch aggregation level, were analyzed with the application of the multivariate linear regression analysis method. The results showed that all the metrics were effective in quantifying a certain component of spatial patterns, and proved that what the metrics quantified were not a single component but the complexity of several components of spatial patterns. The study also showed a distinct inconsistency between the performances of landscape metrics in simulated landscapes and the real urban landscape of Shenzhen, China. It was suggested that the inconsistency resulted from the difference of the correlation among spatial pattern components between simulated and real landscapes. After considering the very difference, the changes of all 23 landscape metrics against changing of number of patch types in simulated landscapes were consistent with those in the real landscape. The phenomenon was deduced as the sign effect of spatial pattern components on landscape metrics, which was of great significance to the proper use of landscape metrics. |
| [90] | . |
| [91] | 城市扩张具有典型的阶段性特征,城市化初期的不透水面快速蔓延和中后期的生态环境约束往往呈现非线性关系。基于多时相数据对典型城市发展中关键指标的变化拐点进行识别,将有助于认识城市景观演变的时间节点,理解城市化的生态响应过程。本文选用深圳市西部1987-2015年长时序Landsat影像共27期,逐年提取新构建的归一化裸露指数（MNDBI＊）与归一化植被指数（NDVI＊）,从而在时间上寻找城市增长的转折点,在空间上识别不同空间位置的景观演变特征。研究结果表明,1987-2015年深圳市城市增长十分明显,并以2003年为拐点经历了＂快速增长＂至＂平稳约束＂的变化;与此对应,植被指数的关键拐点与城市化拐点基本重合,印证了城市建设用地扩张和生态系统响应的时空关联特征。此外,从空间分异来看,深圳市南部各区的城市化约束期出现相对更早,拐点一般在1995-1998年间;而北部各区的快速城市化时期持续更长,一般在2003-2006年后趋于平稳。在空间上,以市图书馆为中心刻画西、北、西北、东北剖面线方向的指标动态,发现采样中心附近的景观类型变化较小,而更远辐射半径经历了更大幅度的城市化;这说明深圳市南部城市发展较早达到饱和,且近30年的城市扩张以由南向北的放射式蔓延为主。面临城市化带来的生态威胁,相关环保措施的有力实施仅能延缓城市化导致的生境退化步伐,城市扩张所带来的生态破坏依然不容小觑,合理而有力的政策颁布、实施与监管在未来的城市发展中极为必要。 . 城市扩张具有典型的阶段性特征,城市化初期的不透水面快速蔓延和中后期的生态环境约束往往呈现非线性关系。基于多时相数据对典型城市发展中关键指标的变化拐点进行识别,将有助于认识城市景观演变的时间节点,理解城市化的生态响应过程。本文选用深圳市西部1987-2015年长时序Landsat影像共27期,逐年提取新构建的归一化裸露指数（MNDBI＊）与归一化植被指数（NDVI＊）,从而在时间上寻找城市增长的转折点,在空间上识别不同空间位置的景观演变特征。研究结果表明,1987-2015年深圳市城市增长十分明显,并以2003年为拐点经历了＂快速增长＂至＂平稳约束＂的变化;与此对应,植被指数的关键拐点与城市化拐点基本重合,印证了城市建设用地扩张和生态系统响应的时空关联特征。此外,从空间分异来看,深圳市南部各区的城市化约束期出现相对更早,拐点一般在1995-1998年间;而北部各区的快速城市化时期持续更长,一般在2003-2006年后趋于平稳。在空间上,以市图书馆为中心刻画西、北、西北、东北剖面线方向的指标动态,发现采样中心附近的景观类型变化较小,而更远辐射半径经历了更大幅度的城市化;这说明深圳市南部城市发展较早达到饱和,且近30年的城市扩张以由南向北的放射式蔓延为主。面临城市化带来的生态威胁,相关环保措施的有力实施仅能延缓城市化导致的生境退化步伐,城市扩张所带来的生态破坏依然不容小觑,合理而有力的政策颁布、实施与监管在未来的城市发展中极为必要。 |
| [92] | Changes in biodiversity owing to vegetation degradation resulting from widespread urbanization demands serious attention. However, the connection between vegetation degradation and urbanization appears to be complex and nonlinear, and deserves a series of long-term observations. On the basis of the Normalized Difference Vegetation Index (NDVI) and the image digital number (DN) in nighttime stable light data (NTL), we delineated the spatiotemporal relations between urbanization and vegetation degradation of different metropolises by using a simplified NTL calibration method and Theil-Sen regression. The results showed clear and noticeable spatiotemporal differences. On spatial relations, rapidly urbanized cities were found to have a high probability of vegetation degradation, but in reality, not all of them experience sharp vegetation degradation. On temporal characteristics, the degradation degree was found to vary during different periods, which may depend on different stages of urbanization and climate history. These results verify that under the scenario of a vegetation restoration effort combined with increasing demand for a high-quality urban environment, the urbanization process will not necessarily result in vegetation degradation on a large scale. The positive effects of urban vegetation restoration should be emphasized since there has been an increase in demand for improved urban environmental quality. However, slight vegetation degradation is still observed when NDVI in an urbanized area is compared with NDVI in the outside buffer. It is worthwhile to pay attention to landscape sustainability and reduce the negative urbanization effects by urban landscape planning. |
| [93] | Use of the normalized difference vegetation index (NDVI) to build long-term vegetation trends is one of the most effective techniques for identifying global environmental change. Trend identification can be achieved by ordinary least squares (OLS) analysis or the Theil en (TS) procedure with a Mann endall (MK) significance test, and these linear regression approaches have been widely used. However, vegetation changes are not linear, and thus the response of vegetation to global climate change may follow non-linear trends. In this article, a polynomial trend-fitting method, which uses stepwise regression and expands on previous research, is presented. With an improved fitting ability, this procedure may reveal trends that were concealed by linear fitting methods. Globally, the traditional TS-MK method reveals significant greening trends for 37.27% of vegetated land, and significant browning trends for 7.98%. Using the polynomial analysis, 34.62% of pixels were fitted by high-order trends. The significant greening trends covered up to 30% of cultivated land, thus indicating that cultivated vegetation may be increasing faster than natural vegetation. Significant vegetation browning mostly occurred in sparse vegetation areas, which suggests that vegetation growth may be more sensitive to climate change in arid regions. Our results show that use of polynomial analysis can help further elucidate global NDVI trends. |
| [94] | Identifying historical trends in the integrated frequencies of various climate extremes is meaningful in climatic hazard research. However, the variation trends in regional climate extremes still need |
| [95] | Unprecedented rapid urbanization in China during the past several decades has been accompanied by extensive urban landscape renewal, which has increased the urban thermal environmental risk. However, landscape change is a sufficient but not necessary condition for land surface temperature (LST) variation. Many studies have merely highlighted the correlation between landscape pattern and LST, while neglecting to comprehensively present the spatiotemporal diversification of LST change under urban landscape renewal. Taking the main city of Shenzhen as a case study area, this study tracked the landscape renewal and LST variation for the period 1987–2015 using 49 Landsat images. A decision tree algorithm suitable for fast landscape type interpretation was developed to map the landscape renewal. Analytical tools that identified hot-cold spots, the gravity center, and transect of LST movement were adopted to identify LST changes. The results showed that the spatial variation of LST was not completely consistent with landscape change. The transformation from Green landscape to Grey landscape usually increased the LST within a median of 0.2 °C, while the reverse transformation did not obviously decrease the LST (the median was nearly 0 °C). The median of LST change from Blue landscape to Grey landscape was 1.0 °C, corresponding to 0.5 °C in the reverse transformation. The imbalance of LST change between the loss and gain of Green or Blue landscape indicates the importance of protecting natural space, where the benefits in terms of temperature mitigation cannot be completely substituted by reverse transformation. |
| [96] | Rates, patterns, and consequences of urban expansion are drawing increasing attention globally because of their profound impacts on socioeconomics, human life, and the environment. Horizontal comparat |
| [97] | Abstract The scale of urbanization in China during the past three decades is unprecedented in human history, and the processes are poorly understood. Here we present an effort to map the urban land expansion processes of 32 major cities in China from 1978 to 2010 using Landsat satellite data to understand the temporal and spatial characteristics. Results showed that the urban extent of the 32 cities expanded exponentially with very high annual rates varying from 3.2% to 12.8%. Temporal fluctuation in urban expansion rates in these 32 cities was obvious, with unexpected and alarming expansion rates from 2005 to 2010 that drastically exceeded their expectation, which was calculated from the long-term trend between 1978 and 2005, by 45%. Overall, we found that the growth rates of cities during the entire study period were inversely related to city size, contradicting the theory or Gibrat's law, which states that the growth rate is independent of city size. More detailed analysis indicated that city growth in China has transitioned from contradicting to conforming to Gibrat's law since 1995. Our study suggests that the urban expansion theory (i.e., Gibrat's law) does not fit Chinese expansion consistently over time, and the exact causes are unknown. Exploring the causes in future research will improve our understanding of the theory and, more importantly, understand the feasibility of the theoretical relationship between city size and expansion rate in guiding contemporary urban expansion planning. |
| [98] | Urban heat island (UHI) is a major anthropogenic alteration on Earth environments and its geospatial pattern remains poorly understood over large areas. Using MODIS data from 2003 to 2011, we quantified the diurnal and seasonal surface UHI intensity (SUHII, urban uburban temperature difference) in China's 32 major cities, and analyzed their spatial variations and possible underlying mechanisms. Results show that the annual mean SUHII varied markedly from 0.01 to 1.87 C in the day and 0.35 to 1.95 C at night, with a great deal of spatial heterogeneities. Higher SUHIIs for the day and night were observed in the southeastern and northern regions, respectively. Moreover, the SUHII differed greatly by season, characterized by a higher intensity in summer than in winter during the day, and the opposite during the night for most cities. Consequently, whether the daytime SUHII was higher or lower than the nighttime SUHII for a city depends strongly on the geographic location and research period. The SUHII's distribution in the day related closely to vegetation activity and anthropogenic heat releases in summer, and to climate (temperature and precipitation) in winter, while that at night linked tightly to albedo, anthropogenic heat releases, built-up intensity, and climate in both seasons. Overall, we found the overwhelming control of climate on the SUHII's spatial variability, yet the factors included in this study explained a much smaller fraction of the SUHII variations in the day compared to night and in summer relative to winter (day vs. night: 57% vs. 72% in summer, and 61% vs. 90% in winter, respectively), indicating more complicated mechanisms underlying the distribution of daytime SUHII, particularly in summer. Our results highlight the different diurnal (day and night) and seasonal (summer and winter) SUHII's spatial patterns and driving forces, suggesting various strategies are needed for an effective UHI effect mitigation. |
| [99] | Urban heat island (UHI) is one major anthropogenic modification to the Earth system that transcends its physical boundary. Using MODIS data from 2003 to 2012, we showed that the UHI effect decayed exponentially toward rural areas for majority of the 32 Chinese cities. We found an obvious urban/ rural temperature “cliff”, and estimated that the footprint of UHI effect (FP, including urban area) was 2.3 and 3.9 times of urban size for the day and night, respectively, with large spatiotemporal heterogeneities. We further revealed that ignoring the FP may underestimate the UHI intensity in most cases and even alter the direction of UHI estimates for few cities. Our results provide new insights to the characteristics of UHI effect and emphasize the necessity of considering city- and time-specific FP when assessing the urbanization effects on local climate. |
| [100] | 61It is essential to map land surface conditions accurately and timely.61It is critical to use concurrent urban extent and LST maps to estimate UHI.61Definition of urban and surrounding areas matters for the estimate of UHI effect. |
| [101] | Urbanization-induced phenological shifts may provide evidence on how vegetation will respond to global warming. However, the effects of urbanization on vegetation phenology are poorly understood in urban environments. Using MODIS data between 2007 and 2013, we investigated the trends of the phenological metrics (i.e., start, end, and length of growing season: SOS, EOS and GSL) of individual cities and across cities relative to rural areas for China's 32 major cities. We found that the effects of urbanization on phenology decayed exponentially toward rural areas, and were closely related to the land surface temperature (LST) for more than half of the cities. The phenological sensitivity to temperature were 9–1102days SOS advance and 6–1002days EOS delay per 102°C increase of LST. On average across all cities, the growing season started 11.902days earlier and ended 5.402days later in urban zones compared to rural counterparts. The urbanization effects increased with increasing latitudes, following the pattern of urban heat island effects in general. Our study suggests the value of urban environments in studying the phenological responses to future global change. However, the urbanization impacts are complex and need more direct observations, experimental manipulations, and cross-boundary inter-comparison studies. |
| [102] | Urbanization, a dominant global demographic trend, leads to various changes in environments (e.g., atmospheric COincrease, urban heat island). Cities experience global change decades ahead of other systems so that they are natural laboratories for studying responses of other nonurban biological ecosystems to future global change. However, the impacts of urbanization on vegetation growth are not well understood. Here, we developed a general conceptual framework for quantifying the impacts of urbanization on vegetation growth and applied it in 32 Chinese cities. Results indicated that vegetation growth, as surrogated by satellite-observed vegetation index, decreased along urban intensity across all cities. At the same time, vegetation growth was enhanced at 85% of the places along the intensity gradient, and the relative enhancement increased with urban intensity. This growth enhancement offset about 40% of direct loss of vegetation productivity caused by replacing productive vegetated surfaces with nonproductive impervious surfaces. In light of current and previous field studies, we conclude that vegetation growth enhancement is prevalent in urban settings. Urban environments do provide ideal natural laboratories to observe biological responses to environmental changes that are difficult to mimic in manipulative experiments. However, one should be careful in extrapolating the finding to nonurban environments because urban vegetation is usually intensively managed, and attribution of the responses to diverse driving forces will be challenging but must be pursued. |
| [103] | 作为城市地域自然生态系统服务供给的基本载体,生态用地基于土地利用/土地覆被的内在关联将人类社会发展与自然生态演替耦合关联在一起,已成为统筹解决城市建设扩展与自然生态保护矛盾的重要综合途径;城市生态用地的需求测算直接决定供需均衡分析结果,是城乡统筹生态用地规划与管理的关键环节。本文在系统梳理生态用地概念内涵的基础上,对比分析了生态需求与生态用地需求的概念异同;提出基于空间与功能的城市生态用地需求测算概念框架,并据此将已有测算方法归并为经验判定法、生态系统服务法、空间格局法3大类,从综合性、代表性、阈值与规模、位置等方面对比分析了法定定额法、历史趋势预判法、生态足迹法、碳氧平衡法、生态安全格局法等具体方法的基本特征及其优缺点;最后将下一步研究的重点趋向概括为基于土地生态功能的城市生态用地分类、基于土地生态格局的城市生态用地效益综合测算、基于多目标情景的城市生态用地功能综合权衡、基于生态用地供需平衡分析的城市生态腹地识别4个方面。 . 作为城市地域自然生态系统服务供给的基本载体,生态用地基于土地利用/土地覆被的内在关联将人类社会发展与自然生态演替耦合关联在一起,已成为统筹解决城市建设扩展与自然生态保护矛盾的重要综合途径;城市生态用地的需求测算直接决定供需均衡分析结果,是城乡统筹生态用地规划与管理的关键环节。本文在系统梳理生态用地概念内涵的基础上,对比分析了生态需求与生态用地需求的概念异同;提出基于空间与功能的城市生态用地需求测算概念框架,并据此将已有测算方法归并为经验判定法、生态系统服务法、空间格局法3大类,从综合性、代表性、阈值与规模、位置等方面对比分析了法定定额法、历史趋势预判法、生态足迹法、碳氧平衡法、生态安全格局法等具体方法的基本特征及其优缺点;最后将下一步研究的重点趋向概括为基于土地生态功能的城市生态用地分类、基于土地生态格局的城市生态用地效益综合测算、基于多目标情景的城市生态用地功能综合权衡、基于生态用地供需平衡分析的城市生态腹地识别4个方面。 |
| [104] | Vegetation is one of the most important components of the terrestrial ecosystem and, thus, monitoring the spatial and temporal dynamics of vegetation has become the key to exploring the basic process of the terrestrial ecosystem. Vegetation change studies have focused on the relationship between climatic factors and vegetation dynamics. However, correlations among the climatic factors always disturb the results. In addition, the impact of anthropogenic activities on vegetation dynamics was indeterminate. Here, vegetation dynamics in 14 provinces in Eastern China over a 10-year period was quantified to determine the driving mechanisms relating to climate and anthropogenic factors using partial correlation analysis. The results showed that from 1999 to 2008, the vegetation density increased in the whole, with spatial variations. The vegetation improvement was concentrated in the Yangtze River Delta, with the vegetation degradation concentrated in the other developed areas, such as Beijing-Tianjin-Hebei Region and the Pearl River Delta. The annual NDVI changes were mainly driven by temperature in Northeast China and the Pearl River Delta, and by precipitation in the Bohai Rim; while in the Yangtze River Delta, the driving forces of temperature and precipitation almost equaled each other. Furthermore, the impact of anthropogenic activities on vegetation dynamics had accumulative effects in the time series, and had a phase effect on the vegetation change trend. |
| [105] | CONTEXT: Eco-environmental effects of urbanization are a focus in landscape ecology. OBJECTIVE: The influences of population, economic and spatial development during the urbanization process in Beijing City, China on net primary productivity (NPP) were analyzed. The responding mechanism of NPP in different urbanization stages was also examined to develop advice about eco-environmental sustainability of urban development. METHODS: Using the Carnegie Ames Stanford Approach model, we estimated NPP. Using linear regression and polynomial regression analysis, we analyzed NPP responses to stages of urbanization. RESULTS: High NPP areas were located in northeast Yanqing, northwest Miyun, northern Huairou and Pinggu. The distribution of NPP generally occurred in the following order from high NPP to low NPP: outer suburbs, inner suburbs, encircled city center, and inner city. Because of the heat island effect in winter, the estimated NPP in the encircled city center and inner city was higher in 2009 than in 2001. There was a negative correlation between NPP and both economic and spatial urbanization, but an increase in population did not necessarily lead to an immediate decrease in NPP. An analysis of NPP dynamics in five kinds of urban development zones showed that urbanization resulted in a lasting and observable loss of NPP over time and space, although there was some promotion of NPP in highly urbanized zones. CONCLUSION: There are three stages in the response of NPP to urbanization: damage stage, antagonistic stage, and coordination stage. The stage threshold depends on local eco-environmental management and urban planning interventions. |
| [106] | 61LST dynamic was examined in Beijing during 2001–2009.61LST increased averagely in the whole metropolitan area but decreased in city center.61Built-up areas and barren land contribute most to UHI.61Cooling effects of ecological land is obvious with the proportion above 70%.61LST is determined more by landscape composition than spatial configuration. |
| [107] | 61PM2.5increased significantly in central and eastern China during 1999–2011.61National center of average PM2.5shifted to the southeast in China.61A spatial zoning with two standard contours was proposed for PM2.5control.61Health risk was the highest in central and eastern China, with fast growth rate.61Spatial patterns of PM2.5are quantified using standard deviation ellipse analysis. |
| [108] | Green space plays an important role in complex urban ecosystems and provides significant ecosystem services with environmental, aesthetic, recreational and economic benefits. Beijing is the capital city of China and has a large population of about 15.81 million. Construction of green spaces is an important part of sustainable development in Beijing. To attain the sustainable development of Beijing as a capital city, an international city, a historical cultural city, and a living amenity city, this article attempts to develop a comprehensive plan of green space development both at the municipal and regional levels. At the municipal level of Beijing, based on the study of green space changes, and taking physical geographic conditions and historical context into account, we propose to establish green barriers in the mountainous area, and plan a comprehensive green space pattern composed of one city, two rings, three networks, eight water areas, nine fields, and several patches in the plain area. At the regional level of the Capital Circle Region, integrating the characteristics and causes of main environmental issues, we design a macroscopic pattern—“barriers by mountains in the northwest,” “seaward open spaces in the southeast,” “grassland-forest-field-coast zones,” and “green-blue symphony”—for ecological restoration and green space construction. Finally, we discuss the principles necessary to implement green space planning considering adaptation to local conditions, composite function exploitation, interregional equity and integrated planning. |
| [109] | <p>本文从“绿色空间”这一城市发展中人与自然统筹的切入点入手, 通过对北京市域绿色空 间格局和演化过程的追踪, 从土地利用类型的角度, 对1992 年、1996 年、2000- 2004 年土地变更 数据进行分类汇总, 通过计算绿色空间的信息熵, 分区域揭示绿色空间的面积和结构变化, 探索 了北京市绿色空间的格局演变特征及影响因素, 为北京市域的生态建设提供科学依据。</p> . <p>本文从“绿色空间”这一城市发展中人与自然统筹的切入点入手, 通过对北京市域绿色空 间格局和演化过程的追踪, 从土地利用类型的角度, 对1992 年、1996 年、2000- 2004 年土地变更 数据进行分类汇总, 通过计算绿色空间的信息熵, 分区域揭示绿色空间的面积和结构变化, 探索 了北京市绿色空间的格局演变特征及影响因素, 为北京市域的生态建设提供科学依据。</p> |
| [110] | 由于生态系统服务的多样性、空间分布的不均衡性以及人类使用的选择性,在人为活动和自然因素作用下,服务之间的关系出现了此消彼长的权衡、相互增益的协同等变化。理解服务权衡与协同的表现类型、形成机理、尺度依存和区域差异,对于制定区域发展与生态保护"双赢"的政策措施具有重要意义。从相互作用与联系、类型与形成机制、研究方法与工具、尺度效应以及不确定性等方面评述了生态系统服务权衡与协同的国内外研究进展和局限性,并对研究趋势进行了展望。在此基础上,提出从地理学视角研究生态系统服务权衡与协同的主要议题,包括服务供需的时空异质性、权衡与协同的形成机制、尺度依存和区域差异等。可为拓展生态系统服务权衡与协同研究的深度和广度,提升地理学综合研究水平提供借鉴与参考。 . 由于生态系统服务的多样性、空间分布的不均衡性以及人类使用的选择性,在人为活动和自然因素作用下,服务之间的关系出现了此消彼长的权衡、相互增益的协同等变化。理解服务权衡与协同的表现类型、形成机理、尺度依存和区域差异,对于制定区域发展与生态保护"双赢"的政策措施具有重要意义。从相互作用与联系、类型与形成机制、研究方法与工具、尺度效应以及不确定性等方面评述了生态系统服务权衡与协同的国内外研究进展和局限性,并对研究趋势进行了展望。在此基础上,提出从地理学视角研究生态系统服务权衡与协同的主要议题,包括服务供需的时空异质性、权衡与协同的形成机制、尺度依存和区域差异等。可为拓展生态系统服务权衡与协同研究的深度和广度,提升地理学综合研究水平提供借鉴与参考。 |
| [111] | Modern physical geography in China grew from Chinese traditional geography and has been profoundly influenced by the geographical disciplines of Euro-America and Russia. Since the 1950s, integrated studies of physical geography in China have made remarkable progress in the fields of comprehensive physical geographical regionalization, land studies, landscape ecology, and land surface geographical processes. During the past few decades, under the background of global change and rapid socio-economic transformation, a series of environmental and resources problems have boomed in China. To solve these problems and promote the development of integrated studies of physical geography, the following issues were proposed as research priorities: (1) coupling of land surface patterns and processes; (2) integrated research on regional responses and adaptation to global change; (3) analysis of human dimensions of the earth system; (4) ecosystem service research from a geographical perspective; (5) integration of multi-source data and model development; (6) integrated studies on unique geographical units; and (7) important global issues and relevant international programs. |
| [112] | 生态系统服务研究现已成为国内外的研究热点。回顾生态系统服务研究的历程可以发现,研究范式正在从自然科学研究范式向自然科学与社会科学综合研究范式转向。生态系统服务研究更加重视时空异质性、更加关注流动性与区域效应,更加强调生态系统服务对人类福祉的作用。在生态系统结构、过程与功能─服务─人类收益与福祉级联框架中,地理学的主要分支都可以找到自身的研究议题。在此过程中,逐渐建构起来的生态系统服务地理学,不仅可以为生态系统服务研究提供学科支撑,同时可以丰富和拓展地理学的研究内容。本文在评述生态系统服务研究历程和发展趋势的基础上,分析了地理学参与生态系统服务研究的逻辑必然性以及面临的机遇与挑战。为了推进生态系统服务研究的"地理化"转向,我们提议发展生态系统服务地理学,并初步描绘了生态系统服务地理学的学科框架,包括定义、研究范畴、研究内容及主要研究议题等。 . 生态系统服务研究现已成为国内外的研究热点。回顾生态系统服务研究的历程可以发现,研究范式正在从自然科学研究范式向自然科学与社会科学综合研究范式转向。生态系统服务研究更加重视时空异质性、更加关注流动性与区域效应,更加强调生态系统服务对人类福祉的作用。在生态系统结构、过程与功能─服务─人类收益与福祉级联框架中,地理学的主要分支都可以找到自身的研究议题。在此过程中,逐渐建构起来的生态系统服务地理学,不仅可以为生态系统服务研究提供学科支撑,同时可以丰富和拓展地理学的研究内容。本文在评述生态系统服务研究历程和发展趋势的基础上,分析了地理学参与生态系统服务研究的逻辑必然性以及面临的机遇与挑战。为了推进生态系统服务研究的"地理化"转向,我们提议发展生态系统服务地理学,并初步描绘了生态系统服务地理学的学科框架,包括定义、研究范畴、研究内容及主要研究议题等。 |
| [113] | <div >生态系统管理是生态系统过程和社会经济目标的权衡，而生态系统服务是联系生态系统与人类福祉的纽带，因此，从生态系统服务的角度进行生态系统管理成为必然。近年来，InVSET模型已发展成为生态系统服务研究的重要工具，为生态系统管理提供了有力的技术支持。本文从生态系统服务定量评估、权衡与决策分析等各方面评述了InVEST模型在生态系统管理中的运用，认为基于InVEST模型的生态系统管理具有科学性高、直观性好和操作性强等优点。但是，目前仍然存在InVEST模型模拟精度较低、服务权衡机理不清晰、文化服务考虑缺失等不足之处有待发展和完善，以期最终为区域生态系统管理决策、实现区域可持续发展提供科学依据。</div><div > </div> . <div >生态系统管理是生态系统过程和社会经济目标的权衡，而生态系统服务是联系生态系统与人类福祉的纽带，因此，从生态系统服务的角度进行生态系统管理成为必然。近年来，InVSET模型已发展成为生态系统服务研究的重要工具，为生态系统管理提供了有力的技术支持。本文从生态系统服务定量评估、权衡与决策分析等各方面评述了InVEST模型在生态系统管理中的运用，认为基于InVEST模型的生态系统管理具有科学性高、直观性好和操作性强等优点。但是，目前仍然存在InVEST模型模拟精度较低、服务权衡机理不清晰、文化服务考虑缺失等不足之处有待发展和完善，以期最终为区域生态系统管理决策、实现区域可持续发展提供科学依据。</div><div > </div> |
| [114] | 土地利用变化直接改变生态系统结构、功能和过程,是生态系统服务变化的重要驱动力之一.基于黑河中游2000年和2014年土地利用／覆被数据和相关地理信息数据,利用InVEST模型模拟了黑河中游2000年和2014年生境质量、土壤保持量、水源涵养和气体调节4种生态系统服务的价值及空间分布特征,并通过划分5 km×5 km的格网计算其与土地利用强度的Pearson相关系数,定量分析土地利用变化对生态系统服务的影响.结果表明:①2014年,黑河中游生境质量一般,土壤保持总量6.92×108 t,产水量3.93 × 10s m3,固碳4.55×107 t;②从2000-2014年,生境质量、水源涵养和气体调节能力大幅下降,东南部表现最为显著,土壤保持功能基本稳定;③土地利用强度与土壤保持不存在显著相关性,与生境质量、水源涵养和气体调节服务均呈正相关关系,表明土地利用强度的增加在一定程度上有利于生态系统服务价值的提高.研究结果可为黑河中游生态系统管理提供借鉴. . 土地利用变化直接改变生态系统结构、功能和过程,是生态系统服务变化的重要驱动力之一.基于黑河中游2000年和2014年土地利用／覆被数据和相关地理信息数据,利用InVEST模型模拟了黑河中游2000年和2014年生境质量、土壤保持量、水源涵养和气体调节4种生态系统服务的价值及空间分布特征,并通过划分5 km×5 km的格网计算其与土地利用强度的Pearson相关系数,定量分析土地利用变化对生态系统服务的影响.结果表明:①2014年,黑河中游生境质量一般,土壤保持总量6.92×108 t,产水量3.93 × 10s m3,固碳4.55×107 t;②从2000-2014年,生境质量、水源涵养和气体调节能力大幅下降,东南部表现最为显著,土壤保持功能基本稳定;③土地利用强度与土壤保持不存在显著相关性,与生境质量、水源涵养和气体调节服务均呈正相关关系,表明土地利用强度的增加在一定程度上有利于生态系统服务价值的提高.研究结果可为黑河中游生态系统管理提供借鉴. |
| [115] | . Ecosystem service is the key comprehensive indicator for measuring the ecological effects of urbanization. Although various studies have found a causal relationship between urbanization and ecosystem services degradation, the linear or non-linear characteristics are still unclear, especially identifying the impact thresholds in this relationship. This study quantified four ecosystem services (i.e. soil conservation, carbon sequestration and oxygen production, water yield, and food production) and total ecosystem services (TES), and then identified multiple advantageous area of ecosystem services in the peri-urban area of Beijing City. Using piecewise linear regression, the response of TES to urbanization (i.e., population density, GDP density, and construction land proportion) and its thresholds were detected. The results showed that, the TES was high in the north and west and low in the southeast, and there were seven multiple advantageous areas (distributed in the new urban development zone and ecological conservation zone), one single advantageous area (distributed in the ecological conservation zone), and six disadvantageous areas (mainly distributed in the urban function extended zone). TES response to population and economic urbanization each had a threshold (22902person02km 61022 and 107.1502million02yuan02km 61022 , respectively), above which TES decreased rapidly with intensifying urbanization. However, there was a negative linear relationship between land urbanization and TES, which indicated that the impact of land urbanization on ecosystem services was more direct and effective than that of population and economic urbanization. It was also found that the negative impact of urbanization on TES was highest in the urban function extended zone, followed in descending order by that in the new urban development zone and ecological conservation zone. According to the detected relationships between urbanization and TES, the economic and population urbanization should be strengthened accompanied by slowing or even reducing land urbanization, so as to achieve urban ecological sustainability with less ecosystem services degradation. |
| [116] | 作为沟通自然生态系统与人类社会的重要桥梁,生态系统服务一直以来都是地理学、生态学等学科的研究前沿和热点。正确认知生态系统服务之间的关系,是开展多种生态系统服务可持续管理决策的前提,有助于人类福祉的全面提升。本文通过厘定生态系统服务权衡的概念内涵,梳理了生态系统服务权衡的空间、时间和可逆性特征,将多层次人类福祉的满足作为权衡的最终目标,视生态补偿为权衡决策的基本保障途径。生态系统服务权衡关系的识别依托于定量指标法和综合模型法,且权衡关系可能随时空尺度的推移发生改变;情景分析与多目标分析是生态系统服务权衡决策的有效手段。生态系统服务权衡多尺度关联、生态系统服务流与远程耦合、生态系统服务消费与生态补偿,成为当前生态系统服务权衡研究的重点方向。 . 作为沟通自然生态系统与人类社会的重要桥梁,生态系统服务一直以来都是地理学、生态学等学科的研究前沿和热点。正确认知生态系统服务之间的关系,是开展多种生态系统服务可持续管理决策的前提,有助于人类福祉的全面提升。本文通过厘定生态系统服务权衡的概念内涵,梳理了生态系统服务权衡的空间、时间和可逆性特征,将多层次人类福祉的满足作为权衡的最终目标,视生态补偿为权衡决策的基本保障途径。生态系统服务权衡关系的识别依托于定量指标法和综合模型法,且权衡关系可能随时空尺度的推移发生改变;情景分析与多目标分析是生态系统服务权衡决策的有效手段。生态系统服务权衡多尺度关联、生态系统服务流与远程耦合、生态系统服务消费与生态补偿,成为当前生态系统服务权衡研究的重点方向。 |
| [117] | Abstract Freshwater ecosystem service is essential to human’s survival and development. Many studies have documented the spatial differences in the supply and demand of ecosystem services and proposed the concept of ecosystem services flows. However, few studies characterize freshwater ecosystem service flow quantitatively. Therefore, our paper aims to quantify the effects of freshwater ecosystem service flow on downstream areas. We developed a freshwater ecosystem service flow model and applied it in the Beijing–Tianjin–Hebei (BTH) region, China, for the year of 2000, 2005, and 2010. We assessed the regional water security with an improved freshwater security index by integrating freshwater service provision, consumption and flow; and found that most areas of the BTH region (69.2%) were affected by upstream freshwater flows. The areas achieving water security in the region also expanded to 66.9%, 66.1%, and 71.3%, which were 6.4%, 6.8% and 5.7% increments compared to no-flow situation, in 2000, 2005 and 2010, respectively. Setting quota for human water consumption is suggested to further improve water security. These results highlight the need to fully understand the connections between distant freshwater ecosystem service provision and local freshwater ecosystem service consumption. This approach may also help managers to choose more sustainable strategies for critical freshwater resource management across different regions. |
| [118] | <p>作为沟通自然景观与人类社会的重要桥梁,景观功能一直以来都是景观生态学的重要研究内容;多功能景观通过对自然景观功能赋予人类价值评判,与土地利用决策紧密相关,已成为当前景观功能研究的重要发展方向、多学科景观综合研究的重点领域和景观生态学新的学科生长点。在系统梳理多功能景观概念内涵的基础上,对比分析了其与景观多功能性、生态系统服务及多功能农业的概念异同;并从景观多功能性评价、多功能景观空间识别、多功能景观规划与管理等3个方面,重点探讨了近年来国内外多功能景观研究的进展及其主要不足;最后,展望了当前国内外多功能景观研究的重点发展方向,即多功能景观权衡机理解析、多功能景观区域类型识别、多功能景观尺度与划区效应评估、多功能景观动态预测及情景模拟。</p> . <p>作为沟通自然景观与人类社会的重要桥梁,景观功能一直以来都是景观生态学的重要研究内容;多功能景观通过对自然景观功能赋予人类价值评判,与土地利用决策紧密相关,已成为当前景观功能研究的重要发展方向、多学科景观综合研究的重点领域和景观生态学新的学科生长点。在系统梳理多功能景观概念内涵的基础上,对比分析了其与景观多功能性、生态系统服务及多功能农业的概念异同;并从景观多功能性评价、多功能景观空间识别、多功能景观规划与管理等3个方面,重点探讨了近年来国内外多功能景观研究的进展及其主要不足;最后,展望了当前国内外多功能景观研究的重点发展方向,即多功能景观权衡机理解析、多功能景观区域类型识别、多功能景观尺度与划区效应评估、多功能景观动态预测及情景模拟。</p> |
| [119] | As an important approach to the realization of agricultural sustainable development, multifunctionality has become a hot spot in the field of urban agriculture. Taking 13 agricultural counties of Beijing City as the assessing units, this study selects 10 assessing index from ecological, economic and social aspects, determines the index weight using Analytic Hierarchy Process (AHP) method, and establishes an index system for the integrated agricultural function. Based on standardized data from agricultural census and remote sensing, the integrated function and multifunctionality of urban agriculture in Beijing City are assessed through the index grade mapping. The results show that agricultural counties with the highest score in ecological, economic, and social function are Yanqing, Changping, and Miyun, respectively; and the greatest disparity among those counties is economic function, followed by social and ecological function. Topography and human disturbance may be the factors that affect integrated agricultural function. The integrated agricultural function of Beijing rises at the beginning then drops later with the increase of mean slope, average altitude, and distance from the city. The whole city behaves balance among ecological, economic, and social functions at the macro level, with 8 out of the 13 counties belonging to ecology–society–economy balanced areas, while no county is dominant in only one of the three functions. On the micro scale, however, different counties have their own functional inclination: Miyun, Yanqing, Mentougou, and Fengtai are ecology–society dominant, and Tongzhou is ecology–economy dominant. The agricultural multifunctionality in Beijing City declines from the north to the south, with Pinggu having the most significant agricultural multifunctionality. The results match up well with the objective condition of Beijing's urban agriculture planning, which has proved the methodological rationality of the assessment to a certain extent. |
| [120] | Abstract Landscape services can be understood as the spatial explicit and human action produced ecosystem services at the landscape scale. Mapping multiple landscape services of agricultural land at various spatiotemporal scales can reveal the distribution and evolution of landscape services. However, further investigation into the spatiotemporal evolution and driving force of agricultural landscape multifunctionality is still needed. In this study, six landscape services (food supply, habitat maintenance, habitat connectivity, soil retention, landscape aesthetics, and population carrier) were quantified in the Beijing–Tianjin–Hebei region, China. Then, Spearman's rank correlation, partial correlation, principal component analysis and geographically weighted regression were used to identify the driving forces of agricultural landscape multifunctionality. The results showed that agricultural landscape multifunctionality generally increased during 2000–2010. The vegetation factor of NDVI was the most important natural indicator influencing landscape multifunctionality, while the gross domestic product was the most related social indicator. In a spatial non-stationary background, the vegetation component positively influenced multifunctionality; the impacts of the social component were negative in the center of the study area, but positive in the north and east. Because multifunctional landscapes are regarded as one spatial approach to achieving landscape sustainability, far more attentions should be paid to spatial non-stationarity of driving forces associated with agriculture landscape multifunctionality. |
| [121] | <p>生态风险评价是伴随着环境管理目标和环境观念的转变而逐渐兴起并得到发展的一个新的研究领域,它区别于生态影响评价的重要特征在于其强调不确定性因素的作用,区域生态风险评价所涉及的风险源以及评价受体等都在区域内具有空间异质性,因而比一般生态风险评价更复杂。通过讨论区域生态风险评价的特点和方法论基础,对有关概念和评价的方法步骤进行了理论探讨。</p> . <p>生态风险评价是伴随着环境管理目标和环境观念的转变而逐渐兴起并得到发展的一个新的研究领域,它区别于生态影响评价的重要特征在于其强调不确定性因素的作用,区域生态风险评价所涉及的风险源以及评价受体等都在区域内具有空间异质性,因而比一般生态风险评价更复杂。通过讨论区域生态风险评价的特点和方法论基础,对有关概念和评价的方法步骤进行了理论探讨。</p> |
| [122] | 近20a来，随着生态风险评价研究的不断深化，区域生态风险评价的理论和方法日臻完善，与此紧密相关的生态风险管理日益受到了广泛关注。生态风险管理具有基于监控的反馈机制、风险受害者参与、程序灵活非线性化、关注成本效益等共同点。总结了国内外生态风险管理的研究进展，发现近年来生态风险管理的研究多是基于生态风险评价的结果，针对不同的风险类型和等级采取不同的管理措施。国内现有的研究对灾害风险管理的体系、机制建设较为成熟，但区域生态风险管理的机制研究尤其是预警和防范方面研究尚不成熟。基于此，构建了基于风险来临前、风险到来时和风险过后的区域生态风险管理的基本框架，研究结果对生态风险管理理论的构建和实践应用具有重要的意义。 . 近20a来，随着生态风险评价研究的不断深化，区域生态风险评价的理论和方法日臻完善，与此紧密相关的生态风险管理日益受到了广泛关注。生态风险管理具有基于监控的反馈机制、风险受害者参与、程序灵活非线性化、关注成本效益等共同点。总结了国内外生态风险管理的研究进展，发现近年来生态风险管理的研究多是基于生态风险评价的结果，针对不同的风险类型和等级采取不同的管理措施。国内现有的研究对灾害风险管理的体系、机制建设较为成熟，但区域生态风险管理的机制研究尤其是预警和防范方面研究尚不成熟。基于此，构建了基于风险来临前、风险到来时和风险过后的区域生态风险管理的基本框架，研究结果对生态风险管理理论的构建和实践应用具有重要的意义。 |
| [123] | Ecological disasters have been occurring more frequently in recent years. As a result, ecological risk management has become an area of research focus as governments emphasize risk management and preparedness rather than disaster response. Ordos, China, is a transitional semiarid to arid area characterized by high ecological risk. Using remote sensing and geographic information system technology, we developed a framework for ecological risk assessment and management for this ecologically vulnerable region. Eight sources of ecological risk in six types of ecosystems in Ordos were identified, including soil erosion, desertification, gales, sand storms, floods, droughts, pests, and pollution. Quantitative and qualitative research was conducted to develop spatial distributions of the cumulative degree of ecological risk. The majority of the area is characterized by medium or low risk, while areas northwest and southwest of Dalad Banner have very high risk. The main risk factors for each ecosystem were identified based on the degrees of risks of the different regions. Corresponding countermeasures were developed by taking risk intensity, ecosystem features, and risk distribution into consideration. Moreover, the management of desertification risk was discussed in detail. Such risk assessment and management approach are helpful for providing guidance for local ecological risk management for similar areas. |
| [124] | 以黄河三角洲为例进行了区域生态风险评价理论和方法的探讨。针对黄河三角洲主要生态风险源洪涝、干旱、风暴潮灾害、油田污染事故以及黄河断流的概率进行了分级评价；并提出度量生态损失与生态风险的指标和公式，分析了风险源的危害作用；运用遥感资料、历史记录、调查数据和地理信息系统(GIS)技术，完成了区域生态风险综合评价；在此基础上提出黄河三角洲的区域生态风险管理对策。 . 以黄河三角洲为例进行了区域生态风险评价理论和方法的探讨。针对黄河三角洲主要生态风险源洪涝、干旱、风暴潮灾害、油田污染事故以及黄河断流的概率进行了分级评价；并提出度量生态损失与生态风险的指标和公式，分析了风险源的危害作用；运用遥感资料、历史记录、调查数据和地理信息系统(GIS)技术，完成了区域生态风险综合评价；在此基础上提出黄河三角洲的区域生态风险管理对策。 |
| [125] | . |
| [126] | Land use profoundly changes the terrestrial ecosystem and landscape patterns, and these changes reveal the extent and scope of the ecological influence of land use on the terrestrial ecosystem. The study area selected for this research was the middle reaches of the Heihe River. Based on land use data (1986, 2000, and 2014), we proposed an ecological risk index of land use by combining a landscape disturbance index with a landscape fragility index. An exponential model was selected to perform kriging interpolation, as well as spatial autocorrelations and semivariance analyses which could reveal the spatial aggregation patterns. The results indicated that the ecological risk of the middle reaches of the Heihe River was generally high, and higher in the northwest. The high values of the ecological risk index (ERI) tended to decrease, and the low ERI values tended to increase. Positive spatial autocorrelations and a prominent scale-dependence were observed among the ERI values. The main hot areas with High-High local autocorrelations were located in the north, and the cold areas with low-low local autocorrelations were primarily located in the middle corridor plain and Qilian Mountains. From 1986 to 2014, low and relatively low ecological risk areas decreased while relatively high risk areas expanded. A middle level of ecological risk was observed in Ganzhou and Minle counties. Shandan County presented a serious polarization, with high ecological risk areas observed in the north and low ecological risk areas observed in the southern Shandan horse farm. In order to lower the eco-risk and achieve the sustainability of land use, these results suggest policies to strictly control the oasis expansion and the occupation of farmland for urbanization. Some inefficient farmland should transform into grassland in appropriate cases. |
| [127] | 本研究以城市社会—生态系统为风险评价对象,引入生态适应性循环三维框架,将景观生态风险评价指标从单一的景观指数层面扩展至＂潜力—连通度—恢复力＂三维准则,并以深圳市为研究区,基于有序加权平均（OWA）算法对评价结果进行情景设置。研究结果显示,评价中干扰指标主要影响风险评价结果属性值域,而风险空间格局则受暴露指标制约;深圳全市景观生态风险整体呈现＂西高东低＂的分布格局,城市新建成区风险最高,大鹏半岛风险最低,羊台山与笔架山公园则是城区内部的相对风险低值区;基于OWA方法设置情景偏好,绘制＂忽视＂、＂正常＂及＂重视＂三种风险情景下的城市景观生态风险图。本研究基于生态适应性循环理念集成社会—生态系统时空动态干扰与暴露指标表征城市景观生态风险,并通过OWA方法变换主观偏好、降低评价不确定性,可以满足不同发展思路下的城市开发布局需求,从而为城市景观发展空间权衡提供决策支持。 . 本研究以城市社会—生态系统为风险评价对象,引入生态适应性循环三维框架,将景观生态风险评价指标从单一的景观指数层面扩展至＂潜力—连通度—恢复力＂三维准则,并以深圳市为研究区,基于有序加权平均（OWA）算法对评价结果进行情景设置。研究结果显示,评价中干扰指标主要影响风险评价结果属性值域,而风险空间格局则受暴露指标制约;深圳全市景观生态风险整体呈现＂西高东低＂的分布格局,城市新建成区风险最高,大鹏半岛风险最低,羊台山与笔架山公园则是城区内部的相对风险低值区;基于OWA方法设置情景偏好,绘制＂忽视＂、＂正常＂及＂重视＂三种风险情景下的城市景观生态风险图。本研究基于生态适应性循环理念集成社会—生态系统时空动态干扰与暴露指标表征城市景观生态风险,并通过OWA方法变换主观偏好、降低评价不确定性,可以满足不同发展思路下的城市开发布局需求,从而为城市景观发展空间权衡提供决策支持。 |
| [128] | 计算了我国北方农牧交错带中段(冀、蒙、辽交界地带)1961?2007年的气候风险指数，将其与土地易损性系数综合得到生态风险指数，划定生态风险级别，分析气候风险和生态风险的时间序列变化和空间分异规律。得出的结论主要为: 1) 1961 ?2007年，气候风险呈现增加趋势。空间上由东南向西北方向气候风险指数逐渐变大，风险增强；阿巴嘎旗风险极高，浑善达克沙地和科尔沁沙地周围旗县也处在高风险中或者有向高风险变化的趋势。2) 研究区域内，越向北方、向西方的区域生态风险级别越高，风险越大；4级高风险和5级极高风险区域主要集中在阿巴嘎旗南部浑善达克沙地地区和翁牛特旗中北部科尔沁沙地地区。3)生态风险级别较高的地区对草原覆盖度变化、气候变化都表现得更加敏感。 . 计算了我国北方农牧交错带中段(冀、蒙、辽交界地带)1961?2007年的气候风险指数，将其与土地易损性系数综合得到生态风险指数，划定生态风险级别，分析气候风险和生态风险的时间序列变化和空间分异规律。得出的结论主要为: 1) 1961 ?2007年，气候风险呈现增加趋势。空间上由东南向西北方向气候风险指数逐渐变大，风险增强；阿巴嘎旗风险极高，浑善达克沙地和科尔沁沙地周围旗县也处在高风险中或者有向高风险变化的趋势。2) 研究区域内，越向北方、向西方的区域生态风险级别越高，风险越大；4级高风险和5级极高风险区域主要集中在阿巴嘎旗南部浑善达克沙地地区和翁牛特旗中北部科尔沁沙地地区。3)生态风险级别较高的地区对草原覆盖度变化、气候变化都表现得更加敏感。 |
| [129] | . 面向全球城市化进程的快速推进与生物圈环境变化的不断增强，生态风险评价能够明晰制约区域生态持续性的主要生态要素与过程，成为当前自然地理学与宏观生态学应对社会—生态系统综合管理的热点研究领域之一。景观生态学高度关注空间异质性及景观格局—过程互馈，景观生态风险评价则为这一领域提供了新的研究视角。本文明确界定了景观生态风险评价的概念内涵，系统梳理了景观生态风险评价与生态风险评价、区域生态风险评价的异同；从评价对象的类型选择、评价单元的景观意义表征、评价方法的范式统一、评价模型的指数化途径和评价指标权重设定等方面，探讨了国内外景观生态风险评价的近今进展；同时，研究还展望了景观生态风险评价的重点发展方向，即基于景观过程的生态内涵明晰、尺度推绎在风险评价中的应用、评价结果的不确定性分析、耦合非线性生态模型的风险阈值判定、生态系统服务及其价值的整合、源汇景观过程识别与模型综合集成。 . 面向全球城市化进程的快速推进与生物圈环境变化的不断增强，生态风险评价能够明晰制约区域生态持续性的主要生态要素与过程，成为当前自然地理学与宏观生态学应对社会—生态系统综合管理的热点研究领域之一。景观生态学高度关注空间异质性及景观格局—过程互馈，景观生态风险评价则为这一领域提供了新的研究视角。本文明确界定了景观生态风险评价的概念内涵，系统梳理了景观生态风险评价与生态风险评价、区域生态风险评价的异同；从评价对象的类型选择、评价单元的景观意义表征、评价方法的范式统一、评价模型的指数化途径和评价指标权重设定等方面，探讨了国内外景观生态风险评价的近今进展；同时，研究还展望了景观生态风险评价的重点发展方向，即基于景观过程的生态内涵明晰、尺度推绎在风险评价中的应用、评价结果的不确定性分析、耦合非线性生态模型的风险阈值判定、生态系统服务及其价值的整合、源汇景观过程识别与模型综合集成。 |
| [130] | Ecosystem health assessment is always one of the key topics of ecosystem management. However, few studies has focused on assessing ecosystem health of landscapes, which are geo-spatial units composed of different kinds of ecosystem mosaics. Healthy ecosystems should sustainably provide a range of ecosystem services to meet human needs, and such a concept often cannot be expressed using the traditional ecosystem health assessment. Using Shenzhen City in China as a case study area, this research aims to assess the ecosystem health of urban landscapes based on ecosystem services. Results showed a distinct deterioration of urban ecosystem health for all of the 30 units assessed in Shenzhen City during 1978–2005. Five levels were classified with respect to health using fixed thresholds. There were 12 towns appearing with the worst level and 4 towns disappearing with the best level in 2005 compared with the status in 1978. Although there was no significant decrease in the level of health during 1978–2000, by 2005 more than 70% of towns belonged to the top two levels, classifying them as unhealthy. Among all the assessing indicators, the indicators of ecosystem organization contributed least to ecosystem health, except in 1986, and ecosystem services were found to be the most contributive indicator during 1978–2005. It was also suggested that land use patterns provided an integrating bridge among regional ecosystem health, economic development, and environmental performances. |
| [131] | Quantitative analysis of the response of ecosystem health to rural land use change is required to comprehend the human-nature coupling mechanism and to explore the process of global environmental change, which can interpret the ecological effects of regional land use and land cover change comprehensively. However, the existing regional ecosystem health assessment largely ignored either the internal connection of ecosystem health to land use patterns or the internal representation of ecosystem services to ecosystem health. Using Lijiang City of China as a study area, the average normalized difference vegetation index (NDVI), landscape metrics, and ecosystem elasticity coefficient based on different land use types were used as quantitative indicators. Then the coefficient of spatial neighboring effect was introduced to characterize the adjacency effect on ecosystem services, and to generate the index of integrated ecosystem health. The results showed the change of land use was close to 30% at county level from 1986 to 2006, and forest land was the primary land use type. With respect to the declining physical health of ecosystems in all the four counties, the integrated health experienced a slight increase in Lijiang County. The vast majority of towns ecosystem physical health and integrated health declined, while more than 70% of towns did not change distinctly. Ecosystem physical health had distinct influence on the integrated ecosystem health, and ecosystem vitality was the main factor affecting the condition of physical health. Emphasized in the interconnection of pattern and process, this study provided an ecosystem health approach to assessing the integrated ecological effects of regional land use change. |
| [132] | 采用熵权法确定亚洲—太平洋地区水安全评价指标体系中各指标的权重,评估亚洲—太平洋47个国家的水安全状况。国家综合水安全包括生活水安全、经济水安全、城市水安全、环境水安全和水灾害抗御力五个方面,权重比值约为34:19:14:22:11。其中,生活水安全的国家间差异最大,水灾害抗御力的国家间差异最小;经济水安全的区域整体状况最好,而水灾害抗御力的整体水平较不理想。综合水安全的评估结果显示,在国家层面,澳大利亚、新西兰、马来西亚和新加坡的水安全状况最佳,基里巴斯的水安全状况最令人担忧;在区域层面,东亚及太平洋地区的水安全状况较之南亚、东南亚和中西亚为佳;整体而言,亚洲—太平洋地区的整体水安全状况亟待改善。 . 采用熵权法确定亚洲—太平洋地区水安全评价指标体系中各指标的权重,评估亚洲—太平洋47个国家的水安全状况。国家综合水安全包括生活水安全、经济水安全、城市水安全、环境水安全和水灾害抗御力五个方面,权重比值约为34:19:14:22:11。其中,生活水安全的国家间差异最大,水灾害抗御力的国家间差异最小;经济水安全的区域整体状况最好,而水灾害抗御力的整体水平较不理想。综合水安全的评估结果显示,在国家层面,澳大利亚、新西兰、马来西亚和新加坡的水安全状况最佳,基里巴斯的水安全状况最令人担忧;在区域层面,东亚及太平洋地区的水安全状况较之南亚、东南亚和中西亚为佳;整体而言,亚洲—太平洋地区的整体水安全状况亟待改善。 |
| [133] | 合理构建区域土地利用生态安全格局来实施管理对策和改善区域生态安全水平,已经成为区域生态环境保护的新需求。以位于中国北方农牧交错区的鄂尔多斯市为研究区,基于自然地理数据、社会经济统计数据、土地利用/覆被数据等,借助多目标优化模型和GIS空间分析技术,构建了鄂尔多斯市土地利用生态安全格局,结果表明:(1)不适宜性耕地所占比重较大,林地和草地分布比较合理,适宜的未利用地面积所占比重较大,后备土地资源丰富;(2)多目标优化结果显示,耕地、林地、水域和建设用地面积呈现增加的趋势;草地面积基本保持不变;未利用地面积大幅度下降;(3)土地利用生态安全格局显示,耕地面积增加,主要分布在水分条件较好的河流、湖泊和水库等的周边地区以及城镇和乡村居民点周围;林地面积大幅度增加,主要分布在达拉特旗北部和准格尔旗东部;草地略有增加,广泛分布于库布齐沙漠和毛乌素沙地以外的地区;建设用地增加面积主要来自于重点发展城镇的扩展和规划的重点矿产资源开采区;未利用地大幅度减少,主要集中在杭锦旗境内的库布齐沙漠以及乌审旗和鄂托克旗境内的毛乌素沙地。研究结果对鄂尔多斯市土地资源管理和生态安全建设具有重要指导意义。 . 合理构建区域土地利用生态安全格局来实施管理对策和改善区域生态安全水平,已经成为区域生态环境保护的新需求。以位于中国北方农牧交错区的鄂尔多斯市为研究区,基于自然地理数据、社会经济统计数据、土地利用/覆被数据等,借助多目标优化模型和GIS空间分析技术,构建了鄂尔多斯市土地利用生态安全格局,结果表明:(1)不适宜性耕地所占比重较大,林地和草地分布比较合理,适宜的未利用地面积所占比重较大,后备土地资源丰富;(2)多目标优化结果显示,耕地、林地、水域和建设用地面积呈现增加的趋势;草地面积基本保持不变;未利用地面积大幅度下降;(3)土地利用生态安全格局显示,耕地面积增加,主要分布在水分条件较好的河流、湖泊和水库等的周边地区以及城镇和乡村居民点周围;林地面积大幅度增加,主要分布在达拉特旗北部和准格尔旗东部;草地略有增加,广泛分布于库布齐沙漠和毛乌素沙地以外的地区;建设用地增加面积主要来自于重点发展城镇的扩展和规划的重点矿产资源开采区;未利用地大幅度减少,主要集中在杭锦旗境内的库布齐沙漠以及乌审旗和鄂托克旗境内的毛乌素沙地。研究结果对鄂尔多斯市土地资源管理和生态安全建设具有重要指导意义。 |
| [134] | 根据不同情景选择符合区域生态环境与社会经济特点的模型方法，已经成为区域土地利用生态安全格局构建的关键。本文以位于中国北方农牧交错带的鄂尔多斯市为研究区，基于自然地理数据、社会经济统计数据、土地利用/覆被数据，将最小累积阻力模型（MCR）引入土地利用生态安全格局的构建过程，并通过景观格局指数分析了基于MCR模型构建的安全格局与基于土地生态适宜性和多目标优化的安全格局的适用条件。结果显示：前者适宜于维持生态安全的情景，有利于降低土地系统中人类活动的生态风险；后者则适宜于维持生态适宜性的情景，有利于降低土地系统中自然因素的生态风险。研究结果对鄂尔多斯市土地资源的可持续利用具有重要的指导意义。 . 根据不同情景选择符合区域生态环境与社会经济特点的模型方法，已经成为区域土地利用生态安全格局构建的关键。本文以位于中国北方农牧交错带的鄂尔多斯市为研究区，基于自然地理数据、社会经济统计数据、土地利用/覆被数据，将最小累积阻力模型（MCR）引入土地利用生态安全格局的构建过程，并通过景观格局指数分析了基于MCR模型构建的安全格局与基于土地生态适宜性和多目标优化的安全格局的适用条件。结果显示：前者适宜于维持生态安全的情景，有利于降低土地系统中人类活动的生态风险；后者则适宜于维持生态适宜性的情景，有利于降低土地系统中自然因素的生态风险。研究结果对鄂尔多斯市土地资源的可持续利用具有重要的指导意义。 |
| [135] | 近年来,城市化的不断推进使得生态系统面临巨大压力甚至诱发生态灾难,而另一方面人类对于生态系统服务福祉的提升提出了新要求,因此经济发展和生态保护两者之间的矛盾不断激化.生态安全格局作为沟通生态系统服务和人类社会发展的桥梁,目前被视为区域生态安全保障和人类福祉提升的关键环节.在系统梳理生态安全格局与城市增长边界、生态网络、绿色基础设施和生态控制线等概念内涵异同的基础上,从热点区域、生态源地指标筛选、生态阻力面设置与修正、相关研究成果应用等方面阐释区域生态安全格局构建的近今研究进展,并指出当前研究的主要不足;同时提出了区域生态安全格局构建的重点方向,即生态安全格局构建的重要阈值设定、有效性评价、多尺度关联和生态过程耦合等四个方面. . 近年来,城市化的不断推进使得生态系统面临巨大压力甚至诱发生态灾难,而另一方面人类对于生态系统服务福祉的提升提出了新要求,因此经济发展和生态保护两者之间的矛盾不断激化.生态安全格局作为沟通生态系统服务和人类社会发展的桥梁,目前被视为区域生态安全保障和人类福祉提升的关键环节.在系统梳理生态安全格局与城市增长边界、生态网络、绿色基础设施和生态控制线等概念内涵异同的基础上,从热点区域、生态源地指标筛选、生态阻力面设置与修正、相关研究成果应用等方面阐释区域生态安全格局构建的近今研究进展,并指出当前研究的主要不足;同时提出了区域生态安全格局构建的重点方向,即生态安全格局构建的重要阈值设定、有效性评价、多尺度关联和生态过程耦合等四个方面. |
| [136] | Landscape ecological security pattern (LESP) can effectively safeguard urban ecological security, which is vital for urban sustainable development. Previous studies have not adequately considered the |
| [137] | . |
| [138] | 区域生态安全格局构建作为景观生态学的研究热点之一,为区域可持续发展和国土生态屏障建设提供了重要途径,尤其对于灾害频发、生态脆弱的滇中地区,其能够有效规避自然灾害、促进区域生态系统和社会经济系统协调发展.本文以玉溪市为例,针对区域生态环境基底特征,选取水源涵养、固碳释氧、土壤保持和生物多样性等生态系统服务评估自然生境重要性,综合考虑单一类型生态系统服务质量和多功能性识别生态源地;并采用地质灾害敏感性修正基于地类赋值的基本阻力面,运用最小累积阻力模型识别生态廊道,从而构建玉溪市生态安全格局.结果表明:玉溪市生态源地斑块数量为81个,占玉溪市土地总面积的38.4％,与各级自然保护区重合率达75.2％,主要分布在市域西部的山林地和东部的湖泊湿地区域;玉溪市生态廊道总长度1642.04 km,呈“一横三纵”的空间分布格局,沿河谷、断陷盆地等植被覆盖较好的区域延伸.本文针对滇中山地生态脆弱区地质灾害频发特征,构建山地生态安全格局,对于区域山地开发与生态保护能够提供决策指引. . 区域生态安全格局构建作为景观生态学的研究热点之一,为区域可持续发展和国土生态屏障建设提供了重要途径,尤其对于灾害频发、生态脆弱的滇中地区,其能够有效规避自然灾害、促进区域生态系统和社会经济系统协调发展.本文以玉溪市为例,针对区域生态环境基底特征,选取水源涵养、固碳释氧、土壤保持和生物多样性等生态系统服务评估自然生境重要性,综合考虑单一类型生态系统服务质量和多功能性识别生态源地;并采用地质灾害敏感性修正基于地类赋值的基本阻力面,运用最小累积阻力模型识别生态廊道,从而构建玉溪市生态安全格局.结果表明:玉溪市生态源地斑块数量为81个,占玉溪市土地总面积的38.4％,与各级自然保护区重合率达75.2％,主要分布在市域西部的山林地和东部的湖泊湿地区域;玉溪市生态廊道总长度1642.04 km,呈“一横三纵”的空间分布格局,沿河谷、断陷盆地等植被覆盖较好的区域延伸.本文针对滇中山地生态脆弱区地质灾害频发特征,构建山地生态安全格局,对于区域山地开发与生态保护能够提供决策指引. |
| [139] | . |
| [140] | |
| [141] | Based on relative advantage assessment, the zoning of sustainable agricultural development in China is exammed. An index system of sustainable development is constructed, consisting of five supporting systems: (1) agricultural resources, (2) agricultural development, (3) environment and ecosystem, (4) rural society, and (5) science, education and management. Included in the five supporting systems are 95 factors that are selected at the provincial level as basic indices. A method of assessing relative assets/debts is then used to calculate the net assets (i.e. relative advantage) for each provincial unit. This is done for both the five supporting systems and their total capability. The assessment results are then ranked, and the geographical patterns mapped. Based on the above assessment results, the whole country is divided into nine agricultural development regions (first-level), and 22 sub-regions (second-level). The first-level zones reflect each region direction for future sustainable agricultural development and management. The second-level zones reflect their level of development, and whether or not each sub-region has reached the basic criteria of sustainable agricultural development. A zoning at provincial level for sustainable agricultural development in China is, thereby, established. |
| [142] | 综合自然区划一直是中国地理学界的研究核心和热点之一,已有大量的区划方案应用于指导社会生产实践或教学活动中。已有的区划工作主要是基于传统地域划分研究范式,大多采用专家经验集成方法和技术。专家经验与知识的主观性和个体差异性会对区划方案的科学性和客观性产生影响。为了弥补传统区划范式的不足,丰富区划的方法与途径,本文探讨了自组织映射网络(SOFM)在综合自然区划研究中的应用。在GIS技术支持下,秉承传统区划的研究成果,采用温度带、干湿地区和自然区的三级单位系统,分别选取相应的温度指标、水分指标和地形、植被指标,构建和运行不同层次的SOFM网络,将中国陆地区域划分为8个温度带,17个干湿地区和43个自然区,并将区划方案与传统区划方案进行了对比和检验。结果表明,使用基于GIS平台的SOFM网络进行综合自然区划具有划分层次明显、区域分割清晰、客观性强等优点,是对传统区划方法的有力补充和拓展。 . 综合自然区划一直是中国地理学界的研究核心和热点之一,已有大量的区划方案应用于指导社会生产实践或教学活动中。已有的区划工作主要是基于传统地域划分研究范式,大多采用专家经验集成方法和技术。专家经验与知识的主观性和个体差异性会对区划方案的科学性和客观性产生影响。为了弥补传统区划范式的不足,丰富区划的方法与途径,本文探讨了自组织映射网络(SOFM)在综合自然区划研究中的应用。在GIS技术支持下,秉承传统区划的研究成果,采用温度带、干湿地区和自然区的三级单位系统,分别选取相应的温度指标、水分指标和地形、植被指标,构建和运行不同层次的SOFM网络,将中国陆地区域划分为8个温度带,17个干湿地区和43个自然区,并将区划方案与传统区划方案进行了对比和检验。结果表明,使用基于GIS平台的SOFM网络进行综合自然区划具有划分层次明显、区域分割清晰、客观性强等优点,是对传统区划方法的有力补充和拓展。 |
| [143] | 生态地理区划作为自然区划的新分支,近年来受到国内外地理****的广泛关注,其在认识地理分异规律及区域规划活动中发挥着重要作用.传统生态地理分区多依据自上而下的三级演绎途径,且对于多分区方案的对比与优选缺乏定量化准则.黄土高原作为中国典型的生态脆弱区,植被生长与恢复对缓解当地生态困境十分重要,因此以植被多年动态一致性特征作为分区合理性的评价指标,有助于准确揭示当地生境特点及分异规律.为此,选取热量类、水分类、地形类及地表覆被类共9个指标,采用自组织映射网络(SOFM)与GIS空间分析技术,基于黄土高原近30年来自然本底与覆被状况进行生态地理分区;并依循植被动态一致性准则,依据两步筛选法对多种方案进行优选,最终将黄土高原分为六大生态地理区.研究表明:黄土高原修正6分区方案在12个备选分区方案中效果最好;同时,修正6分区方案多年平均NPP离散系数最低,表明该分区内部离散程度最小.分区方案与既有分区方案相比具有较好的一致性,但由于区划尺度存在一定的差异,整体区域划分更为清晰.对生态地理分区方案优选定量方法的探索,有助于提升自下而上生态地理区划的客观性. . 生态地理区划作为自然区划的新分支,近年来受到国内外地理****的广泛关注,其在认识地理分异规律及区域规划活动中发挥着重要作用.传统生态地理分区多依据自上而下的三级演绎途径,且对于多分区方案的对比与优选缺乏定量化准则.黄土高原作为中国典型的生态脆弱区,植被生长与恢复对缓解当地生态困境十分重要,因此以植被多年动态一致性特征作为分区合理性的评价指标,有助于准确揭示当地生境特点及分异规律.为此,选取热量类、水分类、地形类及地表覆被类共9个指标,采用自组织映射网络(SOFM)与GIS空间分析技术,基于黄土高原近30年来自然本底与覆被状况进行生态地理分区;并依循植被动态一致性准则,依据两步筛选法对多种方案进行优选,最终将黄土高原分为六大生态地理区.研究表明:黄土高原修正6分区方案在12个备选分区方案中效果最好;同时,修正6分区方案多年平均NPP离散系数最低,表明该分区内部离散程度最小.分区方案与既有分区方案相比具有较好的一致性,但由于区划尺度存在一定的差异,整体区域划分更为清晰.对生态地理分区方案优选定量方法的探索,有助于提升自下而上生态地理区划的客观性. |
| [144] | 主体功能区划分和土地可持续利用模式设计，对解决我国经济快速发展过程中社会经济和生态环境之间出现的矛盾具有重要的意义。选取位于我国北方农牧交错带的鄂尔多斯市为研究区，以全市52个乡(镇、苏木)作为基本研究单元，采用研究区2008年数据，基于资源环境承载力、现有开发密度和区域发展潜力，从土地资源、水资源、矿产资源、生态安全度、土地利用强度、水资源开发强度、矿产资源开发强度、区位优势、科技潜力和经济活力等构建了主体功能区划分的指标体系，并运用变异系数法确定各指标权重，最终采用聚类分析与三维魔方图相结合的方法，将鄂尔多斯主体功能区划分为优化开发区、I级重点开发区、Ⅱ级重点开发区、限制开发区和禁止开发区，提出了五类主体功能区的协调发展机制和各功能区未来发展定位。分别选择各主体功能区内部的典型乡镇，优化开发区的达拉特旗树林召镇、I级重点开发区的伊金霍洛旗乌兰木伦镇、Ⅱ级重点开发区的乌审旗苏力德苏木和限制开发区的鄂托克旗阿尔巴斯苏木，基于1978年、1988年、2000年和2008年土地覆被数据，通过近30年来的土地利用变化和景观格局的分析，结合主体功能区的总体定位提出了土地可持续利用模式。结果对推进当地生态重建和促进土地可持续利用提供科学的支撑。 . 主体功能区划分和土地可持续利用模式设计，对解决我国经济快速发展过程中社会经济和生态环境之间出现的矛盾具有重要的意义。选取位于我国北方农牧交错带的鄂尔多斯市为研究区，以全市52个乡(镇、苏木)作为基本研究单元，采用研究区2008年数据，基于资源环境承载力、现有开发密度和区域发展潜力，从土地资源、水资源、矿产资源、生态安全度、土地利用强度、水资源开发强度、矿产资源开发强度、区位优势、科技潜力和经济活力等构建了主体功能区划分的指标体系，并运用变异系数法确定各指标权重，最终采用聚类分析与三维魔方图相结合的方法，将鄂尔多斯主体功能区划分为优化开发区、I级重点开发区、Ⅱ级重点开发区、限制开发区和禁止开发区，提出了五类主体功能区的协调发展机制和各功能区未来发展定位。分别选择各主体功能区内部的典型乡镇，优化开发区的达拉特旗树林召镇、I级重点开发区的伊金霍洛旗乌兰木伦镇、Ⅱ级重点开发区的乌审旗苏力德苏木和限制开发区的鄂托克旗阿尔巴斯苏木，基于1978年、1988年、2000年和2008年土地覆被数据，通过近30年来的土地利用变化和景观格局的分析，结合主体功能区的总体定位提出了土地可持续利用模式。结果对推进当地生态重建和促进土地可持续利用提供科学的支撑。 |
| [145] | Given the complexity of land use activities, land ecological suitability analysis can reflect the advantages of regional natural resources and the potential of socioeconomic development. Thus, it could provide scientific evidence for environmentally land use planning in agricultural oasis cities. This research analyzes the principal conflicts and restrictive conditions of regional land use in the main agricultural oasis of the middle reaches of the Heihe River, and identified two kinds of antagonistic forces, i.e., agricultural oasis expansion and ecological conservation land expansion. Then, the minimum accumulative resistance theory and ecology assessment method are introduced to construct a comprehensive land use security model that meets ecological suitability. Furthermore, the strategic patches and radiation corridors for agricultural oasis expansion in the region are recognized through the model calculation. The main conclusions of the model are as follows. First, land use in the region can be clearly divided into four categories: key protected zone, buffer protected zone, moderate developed zone and optimized developed zone. Second, agricultural oasis expansion shows significant strategic patches and radiation corridors information. The strategic point locations are characterized by high-quality soil, rich water resources and outstanding location advantages; while the radiation corridors of each county indicates the direction for ecological suitability, which is significantly affected by the spatial distribution of traffic arteries and ecologically sensitive areas. Third, rural residents can be divided into five categories by the unit of town. Only after effectively identifying the potential and limiting factors of each type could the objective of sustainable management in the arid oasis be achieved. |
| [146] | <p>生态功能分区综合反映了区域自然生态功能的特征差异，是自然资源开发和生态环境保护空间差异化管治的重要依据。针对以往生态功能分区分析框架复杂多样、权重设定人为主观等问题，本文以云南省大理白族自治州为例，基于要素-结构-功能系统分析框架，从基底要素-干扰结构-主导服务三方面构建指标体系，运用自组织特征映射（SOFM）神经网络依次进行流域主导生态系统服务分区、基底要素分区、干扰结构分区和生态功能综合分区，最终将大理州划分为4个生态功能区和10个生态功能亚区。不同要素分区对比结果表明，大理州生态功能综合分区主要受主导生态系统服务制约，二者重叠率达79.98%。本研究基于要素结构功能分析框架，系统刻画了区域生态系统结构与功能特征及其空间差异，为生态功能分区提供了新的方法指引。</p> . <p>生态功能分区综合反映了区域自然生态功能的特征差异，是自然资源开发和生态环境保护空间差异化管治的重要依据。针对以往生态功能分区分析框架复杂多样、权重设定人为主观等问题，本文以云南省大理白族自治州为例，基于要素-结构-功能系统分析框架，从基底要素-干扰结构-主导服务三方面构建指标体系，运用自组织特征映射（SOFM）神经网络依次进行流域主导生态系统服务分区、基底要素分区、干扰结构分区和生态功能综合分区，最终将大理州划分为4个生态功能区和10个生态功能亚区。不同要素分区对比结果表明，大理州生态功能综合分区主要受主导生态系统服务制约，二者重叠率达79.98%。本研究基于要素结构功能分析框架，系统刻画了区域生态系统结构与功能特征及其空间差异，为生态功能分区提供了新的方法指引。</p> |
| [147] | 生态系统服务与土地利用之间有密切关联,生态系统服务分区对区域生态系统服务的管理和土地利用政策的制定有重要意义。本文以京津冀地区为研究区,依据IGBP2001-2009年间的土地利用数据,在对谢高地等制定的中国陆地生态系统单位面积服务价值系数进行校正的基础上,核算了区域内各县(市)级行政单元单位面积生态系统服务的价值量,构建自组织特征映射网络(SOFM)对京津冀的生态系统服务进行分区,并用ArcGIS识别了不同服务类型的热点区,归纳和总结了每个分区的主导服务类型,并结合全国功能主体区划对该区域未来的发展重点和土地利用政策提出建议。依据分类结果,可将京津冀地区分为4 个区域:Ⅰ. 坝上高原和冀西北山区;Ⅱ. 燕山和太行山地;Ⅲ. 冀中南平原区;Ⅳ. 环渤海滨海区。2001-2009年间,除Ⅳ区的生态系统服务价值呈现增加趋势外,其他区域均有不同程度的减少,减少程度依次为Ⅱ>Ⅰ>Ⅲ。Ⅰ区域发展重点为防风固沙和水源涵养;Ⅱ区域为生物多样性重点保护区域;Ⅲ区域应重点调整城镇用地的比例,适当增加其他生态系统服务;Ⅳ区域应增加水源涵养价值,治理土壤盐渍化。 . 生态系统服务与土地利用之间有密切关联,生态系统服务分区对区域生态系统服务的管理和土地利用政策的制定有重要意义。本文以京津冀地区为研究区,依据IGBP2001-2009年间的土地利用数据,在对谢高地等制定的中国陆地生态系统单位面积服务价值系数进行校正的基础上,核算了区域内各县(市)级行政单元单位面积生态系统服务的价值量,构建自组织特征映射网络(SOFM)对京津冀的生态系统服务进行分区,并用ArcGIS识别了不同服务类型的热点区,归纳和总结了每个分区的主导服务类型,并结合全国功能主体区划对该区域未来的发展重点和土地利用政策提出建议。依据分类结果,可将京津冀地区分为4 个区域:Ⅰ. 坝上高原和冀西北山区;Ⅱ. 燕山和太行山地;Ⅲ. 冀中南平原区;Ⅳ. 环渤海滨海区。2001-2009年间,除Ⅳ区的生态系统服务价值呈现增加趋势外,其他区域均有不同程度的减少,减少程度依次为Ⅱ>Ⅰ>Ⅲ。Ⅰ区域发展重点为防风固沙和水源涵养;Ⅱ区域为生物多样性重点保护区域;Ⅲ区域应重点调整城镇用地的比例,适当增加其他生态系统服务;Ⅳ区域应增加水源涵养价值,治理土壤盐渍化。 |
| [148] | 为了提高生态地理分界线识别和定位的客观性，探讨了通过空间小波变换获取多尺度模极大值定位过渡带的方法。以NDVI和降水作为小波多尺度分解的对象，应用db3小波核函数分别对49条样带的模极大值进行了多尺度检测，并在GIS中确定其地理坐标。研究结果表明：识别半干旱半湿润生态地理分界线的最佳空间尺度为20～40 km，小于这一尺度定位过程容易受到局部地表覆被因素如城市区域或地形的影响，大于这一尺度由于要素被过度平滑，造成定位不准；从定位点的聚集度分析，NDVI的定位效果好于降水，特别是在较大空间尺度上。而与综合自然地理区划方案中的半干旱半湿润分界线比较，从定位点的方向性、平均最短距离以及均衡度三项指标综合判断，小波变换对于降水过渡带的定位优于对NDVI的定位。研究证实，空间小变换与GIS结合是提高生态地理分界线识别与定位科学性的重要途径，是对专家系统划分界线方法的有力补充和完善。 . 为了提高生态地理分界线识别和定位的客观性，探讨了通过空间小波变换获取多尺度模极大值定位过渡带的方法。以NDVI和降水作为小波多尺度分解的对象，应用db3小波核函数分别对49条样带的模极大值进行了多尺度检测，并在GIS中确定其地理坐标。研究结果表明：识别半干旱半湿润生态地理分界线的最佳空间尺度为20～40 km，小于这一尺度定位过程容易受到局部地表覆被因素如城市区域或地形的影响，大于这一尺度由于要素被过度平滑，造成定位不准；从定位点的聚集度分析，NDVI的定位效果好于降水，特别是在较大空间尺度上。而与综合自然地理区划方案中的半干旱半湿润分界线比较，从定位点的方向性、平均最短距离以及均衡度三项指标综合判断，小波变换对于降水过渡带的定位优于对NDVI的定位。研究证实，空间小变换与GIS结合是提高生态地理分界线识别与定位科学性的重要途径，是对专家系统划分界线方法的有力补充和完善。 |
| [149] | 本文在综述我国土地资源综合分区研究进展的基础上，建立了土地资源综合分区的原则、依据和等级体系。在前人相关工作的基础上，采用自上而下的演绎途径，根据水热气候指标与地势差异划分出我国的11个土地资源区，即东北山地平原农林用地区、华北平原旱作农业与工矿建设用地区、黄土高原旱作农业与林牧用地区、四川盆地及秦岭山地农林用地区、长江中下游平原农渔与工矿建设用地区、江南丘陵山地农林用地区、云贵高原农林用地区、华南、滇南热带亚热带农林渔果与工矿建设用地区、内蒙古高原及长城沿线旱作农业与牧业用地区、西北内陆干旱荒漠与绿洲农牧用地区、青藏高原高寒荒漠与林牧用地区；在各土地资源区内部，采用自下而上归并的途径，依据区域土地资源利用结构与社会经济属性指标，以县为基本单元，应用Kohonen网络进行非监督分类，在全国续分出41个土地资源亚区。 . 本文在综述我国土地资源综合分区研究进展的基础上，建立了土地资源综合分区的原则、依据和等级体系。在前人相关工作的基础上，采用自上而下的演绎途径，根据水热气候指标与地势差异划分出我国的11个土地资源区，即东北山地平原农林用地区、华北平原旱作农业与工矿建设用地区、黄土高原旱作农业与林牧用地区、四川盆地及秦岭山地农林用地区、长江中下游平原农渔与工矿建设用地区、江南丘陵山地农林用地区、云贵高原农林用地区、华南、滇南热带亚热带农林渔果与工矿建设用地区、内蒙古高原及长城沿线旱作农业与牧业用地区、西北内陆干旱荒漠与绿洲农牧用地区、青藏高原高寒荒漠与林牧用地区；在各土地资源区内部，采用自下而上归并的途径，依据区域土地资源利用结构与社会经济属性指标，以县为基本单元，应用Kohonen网络进行非监督分类，在全国续分出41个土地资源亚区。 |
| [150] | . |
| [151] | 生态功能分区是生态系统管理的重要环节,有助于维持生态可持续性.目前生态功能分区的框架复杂多样,但对多重生态系统服务之间关系的理解还不够深刻.生态系统服务簇可以识别多重生态系统服务间的交互作用,并依据簇的特征对区域进行生态功能分区,从而更好地进行社会-生态系统管理.本文以内蒙古自治区为例,定量评估了供给服务、调节服务和支持服务,以旗县(区)为基本空间单元,运用自组织特征映射网络(SOFM)得到生态系统服务簇、划分生态功能区.结果表明:研究区各项生态系统服务分布整体上呈现从东北向西南递减的格局;供给服务和调节服务存在权衡关系,支持服务和调节服务存在协同关系;依据聚类结果将内蒙古自治区划分为4个生态功能区,分别为西部荒漠生态脆弱区、中部草原水土保持区、东部草原牧业盈余区、东部森林生态均衡区.本研究基于生态系统服务簇的概念,分析了内蒙古自治区多重生态系统服务的权衡与协同关系,为生态功能分区提供了新的视角和方法. . 生态功能分区是生态系统管理的重要环节,有助于维持生态可持续性.目前生态功能分区的框架复杂多样,但对多重生态系统服务之间关系的理解还不够深刻.生态系统服务簇可以识别多重生态系统服务间的交互作用,并依据簇的特征对区域进行生态功能分区,从而更好地进行社会-生态系统管理.本文以内蒙古自治区为例,定量评估了供给服务、调节服务和支持服务,以旗县(区)为基本空间单元,运用自组织特征映射网络(SOFM)得到生态系统服务簇、划分生态功能区.结果表明:研究区各项生态系统服务分布整体上呈现从东北向西南递减的格局;供给服务和调节服务存在权衡关系,支持服务和调节服务存在协同关系;依据聚类结果将内蒙古自治区划分为4个生态功能区,分别为西部荒漠生态脆弱区、中部草原水土保持区、东部草原牧业盈余区、东部森林生态均衡区.本研究基于生态系统服务簇的概念,分析了内蒙古自治区多重生态系统服务的权衡与协同关系,为生态功能分区提供了新的视角和方法. |
| [152] | 综合与区域开发始终是地理学研究的两个重要方面。根据笔者的研究实践,90年代的地理学仍应以“综合地理学与地理建设”作为主要方向。现即以此为题略陈管见。 . 综合与区域开发始终是地理学研究的两个重要方面。根据笔者的研究实践,90年代的地理学仍应以“综合地理学与地理建设”作为主要方向。现即以此为题略陈管见。 |
| [153] | Terrestrial biosphere models (TBMs) have become an integral tool for extrapolating local observations and understanding of land-atmosphere carbon exchange to larger regions. The North American Carbon Program (NACP) Multi-scale synthesis and Terrestrial Model Intercomparison Project (MsTMIP) is a formal model intercomparison and evaluation effort focused on improving the diagnosis and attribution of carbon exchange at regional and global scales. MsTMIP builds upon current and past synthesis activities, and has a unique framework designed to isolate, interpret, and inform understanding of how model structural differences impact estimates of carbon uptake and release. Here we provide an overview of the MsTMIP effort and describe how the MsTMIP experimental design enables the assessment and quantification of TBM structural uncertainty. Model structure refers to the types of processes considered (e.g., nutrient cycling, disturbance, lateral transport of carbon), and how these processes are represented (e.g., photosynthetic formulation, temperature sensitivity, respiration) in the models. By prescribing a common experimental protocol with standard spin-up procedures and driver data sets, we isolate any biases and variability in TBM estimates of regional and global carbon budgets resulting from differences in the models themselves (i.e., model structure) and model-specific parameter values. An initial intercomparison of model structural differences is represented using hierarchical cluster diagrams (a.k.a. dendrograms), which highlight similarities and differences in how models account for carbon cycle, vegetation, energy, and nitrogen cycle dynamics. We show that, despite the standardized protocol used to derive initial conditions, models show a high degree of variation for GPP, total living biomass, and total soil carbon, underscoring the influence of differences in model structure and parameterization on model estimates. |
| [154] | |
| [155] | |
| [156] | Following the recent Global Carbon Project (GCP) synthesis of the decadal methane (CH4) budget over 2000–2012 (Saunois et al., 2016), we analyse here the same dataset with a focus on quasi-decadal and inter-annual variability in CH4 emissions. The GCP dataset integrates results from top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models (including process-based models for estimating land surface emissions and atmospheric chemistry), inventories of anthropogenic emissions, and data-driven approaches. The annual global methane emissions from top-down studies, which by construction match the observed methane growth rate within their uncertainties, all show an increase in total methane emissions over the period 2000–2012, but this increase is not linear over the 13 years. Despite differences between individual studies, the mean emission anomaly of the top-down ensemble shows no significant trend in total methane emissions over the period 2000–2006, during the plateau of atmospheric methane mole fractions, and also over the period 2008–2012, during the renewed atmospheric methane increase. However, the top-down ensemble mean produces an emission shift between 2006 and 2008, leading to 2202[16–32]62Tg CH462yr611 higher methane emissions over the period 2008–2012 compared to 2002–2006. This emission increase mostly originated from the tropics, with a smaller contribution from mid-latitudes and no significant change from boreal regions. The regional contributions remain uncertain in top-down studies. Tropical South America and South and East Asia seem to contribute the most to the emission increase in the tropics. However, these two regions have only limited atmospheric measurements and remain therefore poorly constrained. The sectorial partitioning of this emission increase between the periods 2002–2006 and 2008–2012 differs from one atmospheric inversion study to another. However, all top-down studies suggest smaller changes in fossil fuel emissions (from oil, gas, and coal industries) compared to the mean of the bottom-up inventories included in this study. This difference is partly driven by a smaller emission change in China from the top-down studies compared to the estimate in the Emission Database for Global Atmospheric Research (EDGARv4.2) inventory, which should be revised to smaller values in a near future. We apply isotopic signatures to the emission changes estimated for individual studies based on five emission sectors and find that for six individual top-down studies (out of eight) the average isotopic signature of the emission changes is not consistent with the observed change in atmospheric 13CH4. However, the partitioning in emission change derived from the ensemble mean is consistent with this isotopic constraint. At the global scale, the top-down ensemble mean suggests that the dominant contribution to the resumed atmospheric CH4 growth after 2006 comes from microbial sources (more from agriculture and waste sectors than from natural wetlands), with an uncertain but smaller contribution from fossil CH4 emissions. In addition, a decrease in biomass burning emissions (in agreement with the biomass burning emission databases) makes the balance of sources consistent with atmospheric 13CH4 observations. In most of the top-down studies included here, OH concentrations are considered constant over the years (seasonal variations but without any inter-annual variability). As a result, the methane loss (in particular through OH oxidation) varies mainly through the change in methane concentrations and not its oxidants. For these reasons, changes in the methane loss could not be properly investigated in this study, although it may play a significant role in the recent atmospheric methane changes as briefly discussed at the end of the paper. |
| [157] | ABSTRACT Methane (CH4) has a 28-fold greater global warming potential than CO2 over one hundred years. Atmospheric CH4 concentration has tripled since 1750. Anthropogenic CH4 emissions from China has been growing rapidly in the past decades, and contributes more than 10 % of global anthropogenic CH4 emissions with large uncertainties in existing global inventories, generally limited to country-scale statistics. To date, a long-term CH4 emissions inventory including the major sources sectors and based on province-level emission factors is still lacking. In this study, we produced a detailed bottom-up inventory of anthropogenic CH4 emissions from the eight major source sectors in China for the period 1980–2010. In the past three decades, the total CH4 emissions increased from 22.2 [16.6–28.2] Tg CH4 yr611 (mean [minimum-maximum of 95 % confidence interval]) to 45.0 [36.4–58.3] Tg CH4 yr611, and most of this increase took place in the 2000s. This fast increase of the total CH4 emissions after 2000 is mainly driven by CH4 emissions from coal exploitation. The largest contribution to total CH4 emissions also shifted from rice cultivation in 1980 to coal exploitation in 2010. The total emissions inferred in this work compare well with the EPA inventory but appear to be 38 % lower than EDGAR4.2 inventory. The uncertainty of our inventory is investigated using emissions factors collected from published literatures. We also distributed province-scale emissions into 0.502 × 0.502 maps using social-economic activity data. This new inventory could help understanding CH4 budgets at regional scale and guiding CH4 mitigation policies in China. |
| [158] | . |
| [159] | 耕地不断流失的根本原因在于耕地农业利用的比较收益低下,所以建立耕地保护机制的主要途径在于:一方面提高耕地利用的比较收益,另一方面通过提高耕地征用的价值补偿来抑制乱占耕地行为.这两条途径归结于重建耕地资源的价值.本文提出耕地资源具有经济产出价值、生态服务价值和社会保障价值,并尝试用市场价格分别加以评估.耕地资源的经济产出价值为耕地年收益与贴现率之商,生态服务价值为耕地生态服务年价值与贴现率之商,社会保障价值是耕地提供的养老保险和就业保障价值之和.分别选择广东省潮安县、河南省淮阳县和甘肃省会宁县三个县作为案例的评价,以显示我国东、中、西部之间的区域差异.结果表明:耕地资源价值量在各地区之间呈现东高西低的差异;在耕地资源价值构成中,社会保障价值在三个案例区都占60%以上,但所占比重从东到西渐增,说明农民对耕地资源的依赖程度与社会经济发展水平呈反相关.耕地资源的经济产出价值在总价值中所占比重则从东到西递减,主要源于自然和经济生产率的差异.生态服务价值所占比重也表现出东低西高的特点,反映出生态系统从复杂到简单的变化使得农田生态系统对于西部地区生态环境显得更加重要.农业用地为社会提供了大量外部效益,这可成为实行农业补贴的一大理由,也是计算补贴量的一种依据;更可作为提高征地补偿标准的依据.在我国现阶段,耕地是大多数农民赖以生存的主要资源,在农村社会保障体系不完善甚至不存在的情况下,耕地的社会保障功能不可忽视. . 耕地不断流失的根本原因在于耕地农业利用的比较收益低下,所以建立耕地保护机制的主要途径在于:一方面提高耕地利用的比较收益,另一方面通过提高耕地征用的价值补偿来抑制乱占耕地行为.这两条途径归结于重建耕地资源的价值.本文提出耕地资源具有经济产出价值、生态服务价值和社会保障价值,并尝试用市场价格分别加以评估.耕地资源的经济产出价值为耕地年收益与贴现率之商,生态服务价值为耕地生态服务年价值与贴现率之商,社会保障价值是耕地提供的养老保险和就业保障价值之和.分别选择广东省潮安县、河南省淮阳县和甘肃省会宁县三个县作为案例的评价,以显示我国东、中、西部之间的区域差异.结果表明:耕地资源价值量在各地区之间呈现东高西低的差异;在耕地资源价值构成中,社会保障价值在三个案例区都占60%以上,但所占比重从东到西渐增,说明农民对耕地资源的依赖程度与社会经济发展水平呈反相关.耕地资源的经济产出价值在总价值中所占比重则从东到西递减,主要源于自然和经济生产率的差异.生态服务价值所占比重也表现出东低西高的特点,反映出生态系统从复杂到简单的变化使得农田生态系统对于西部地区生态环境显得更加重要.农业用地为社会提供了大量外部效益,这可成为实行农业补贴的一大理由,也是计算补贴量的一种依据;更可作为提高征地补偿标准的依据.在我国现阶段,耕地是大多数农民赖以生存的主要资源,在农村社会保障体系不完善甚至不存在的情况下,耕地的社会保障功能不可忽视. |
| [160] |
