摘要:快速城市化背景下，不同景观降温效率的差异是深入理解景观格局对城市热岛效应影响机理的基础。现有城市热岛研究多以土地利用或土地覆被替代热岛效应的源与汇，往往忽略景观的热特征与相邻景观的热关系，造成信息偏差。需要从景观热特征的视角，探讨面向城市热岛效应的景观分类方法，并分析不同特征景观的降温效率差异。基于"源-汇"景观理论，以深圳市西部为研究区，构建面向城市热岛的景观分类方法，通过2010年TM遥感影像提取NDVI、NDMI及ISA等地表特征及地表温度特性，叠加划分16类城市景观，分析不同地表特征的景观等距离梯度下的温度变化关系，识别城市热岛的"源-汇"景观。在此基础上，分析"源-汇"景观的结构特征，构建以面积和温度为影响因素的景观降温效率指数，结合景观格局指数，分析不同面积与形状的"汇"景观降温效率。结果表明，在16类景观中，5类景观被识别为城市热岛汇景观，面积约533 km²，占研究区总面积的45.5%。降温效率结果表明，"汇"景观的降温效率为1.54，其中绿色空间及阴影景观的降温效率贡献率较高。通过面积与形状的景观格局分析发现，降温效果随两个指数的增加，均呈先升后降的趋势。研究结果为城市规划与城市绿色基础设施建设决策中降温景观的形状和面积设定提供依据，增加景观水平的缓解热岛效应的效率。



Abstract:In the context of rapid urbanization, the difference in cooling efficiency of different landscapes is the basis of understanding the influence mechanism underpinning landscape pattern on urban heat island effect. Existing studies on the heat island effect primarily use land use or land cover as the proxy for the source and sink landscape. This creates an information bias by ignoring the thermal characteristics of the landscape and the thermal relationship with adjacent landscapes. It is deemed necessary to explore the landscape classification method for the urban heat island effect and analyze differences in the cooling efficiency of landscapes with different characteristics. Based on "source-sink" landscape theory, this study constructs a landscape classification method for urban heat island using the western part of Shenzhen City as the study area. Sixteen urban landscape types were divided based on the extraction of surface features such as Normalized Difference Vegetation Index, Normalized Difference Moisture Index, and Impervious Surface Area and land surface temperature from Thematic Mapper remote sensing imagery in 2010. With the analysis of the temperature relationship under the equal distance gradient for landscapes with different surface features, the "source-sink" landscape of urban heat island was identified. On this basis, the composed landscape characteristics of the "source-sink" landscape were analyzed, and the cooling efficiency of landscape with area and temperature as influencing factors was calculated. Combined with the landscape pattern index, the cooling efficiency of separate areas and shapes of the sink landscape was analyzed. Five landscape types were identified as the urban heat island sink landscape. The area is approximately 533 km², accounting for 45.5% of the total study area. Results of cooling efficiency showed that the cooling efficiency of the "sink" landscape is 1.54, among which the contribution rate of green space and shadow landscape was higher. Based on the analysis of landscape patterns, it was found that the cooling efficiency both first increases and then decreases with the increase of the index value. The results can provide support for the shape and area setting of a cooling landscape in urban planning and urban green infrastructure design decision-making, mitigate urban heat island effect and increase the cooling efficiency at the landscape level.





PDF全文下载地址:

https://www.ecologica.cn/stxb/article/pdf/stxb201904140747