王萍,,
胡钢,
葛玉魁
中国地震局地质研究所, 地震动力学国家重点实验室, 北京 100029
基金项目: 国家自然科学基金项目(批准号:41772199)和中央级公益性科研院所基本科研业务专项重点项目(批准号:IGCEA1713)共同资助
详细信息
作者简介: 王慧颖, 女, 28岁, 博士研究生, 构造地质学专业, E-mail:wanghyone@163.com
通讯作者: 王萍, E-mail:wangping@ies.ac.cn
中图分类号: P694;P931收稿日期:2020-02-26
修回日期:2020-05-20
刊出日期:2020-09-30
Landform, sedimentary features and hydraulic models of high-magnitude outburst flood
Wang Huiying,Wang Ping,,
Hu Gang,
Ge Yukui
State Key Laboratory of Earthquakes Dynamics, Institute of Geology, China Earthquakes Administration, Beijing 100029
More Information
Corresponding author: Wang Ping,E-mail:wangping@ies.ac.cn
MSC: P694;P931--> Received Date: 26 February 2020
Revised Date: 20 May 2020
Publish Date: 30 September 2020
摘要
摘要:溃决大洪水作为短时间内水量与沉积物峰值远超正常数量级的非频发洪水，可对流域地貌、地理环境以及人类生存产生巨大影响。国内外****已利用古洪水水文学等方法对全球一系列溃决大洪水事件进行了研究，如北半球冰盖附近和我国西南地区的溃决大洪水等，但针对像青藏高原周缘这类地势高差极大的山区溃决大洪水的研究相对较少，这极大制约了我们深入开展川藏铁路建设、雅鲁藏布江流域水电开发等重大项目的古灾害风险评估。本文对溃决大洪水的研究历史与现状进行了回顾，简述了全球典型溃决大洪水实例中有关侵蚀、沉积地貌与沉积学特征以及水力学模型分析的研究进展，重点介绍了溃决大洪水的典型地貌类型和沉积组合，以及基于二维浅水方程实现的水力学重建，最后简述藏东南地区堰塞-溃决洪水研究现状和意义，以期有助于理解溃决大洪水的发生机制与发展过程，为开展该地区的灾害研究提供参考。
关键词: 溃决大洪水/
洪水地貌/
洪水沉积学特征/
水力学重建/
青藏高原东南部
Abstract:The high-magnitude outburst flood, as an extreme land surface process, is a non-frequent flood with water and sediment discharge peaks exceeding normal one within a short period of time. It has a great impact on river evolution, climate changes, and history of humankind civilization. A lot of researches have focused on geomorphology, sedimentology, and hydraulic model reconstruction of high-magnitude outburst floods near the ice caps in the northern hemisphere, including North America, Siberia and Iceland, using paleohydrology combined with geological, hydrological and other methods.
When high-magnitude outburst flood passes through the river valley, the river channel will be cut severely, and also it will carry a large amount of sediment at the same time, forming a unique flood landform. One succession of a single cycle flood flow formed in a tributary bar can be summarized into a 6-sequence typical vertical sedimentation model by comparing with the Baumar sequence of turbidity sedimentation. Another scientific research approach to study the sedimentary of outburst deposits called "Trinity" is also become an important guide for outburst flood study. However, the analysis of overall sedimentary facies and spatial distribution from dammed-lakes, blocking dam and flood sediments, and the flood sedimentary sequence in the entire river basin has not yet been established. In terms of dating of flood sediments, although the method of absolute age for flood sediments is still insufficient, many reports have recorded14C, OSL, TCN, and K/Ar chronology to reconstruct the time of flood events. On the basis of hydraulic models, numerical simulation using two-dimensional Shallow-water equations for large-scale flood and small-scale floods in plain areas has become mature. However, due to insufficient research on the high-magnitude flood events in the mountain area, the accuracy of hydraulic model needs for high-magnitude outburst flood in mountain need to be improved. Most of domestic flood researches focus on the study of normal scale outburst floods in Western China, and there is insufficient understanding of high-magnitude outburst floods that occur in mountains with high terrain differences, especially in Tibetan Plateau.
Tectonic activity and climatic fluctuations have been strong in the southeastern Tibetan Plateau since the Late Quaternary. River damming events occurred in Tibet are frequent. In recent years, landslides and glacial dammed outburst flood events in the Tibetan Plateau have received increasing attention. A large number of lacustrine sediments and flood deposits have been found in Yigong River, Parlung River, Yarlung River, Jinsha River, Dadu River and Minjiang River. Those events may have start from the Late Pleistocene to the present. Many flood events since the Holocene may have an impact on the rise and fall of ancient civilizations in China and India. Reconstruction of high-magnitude outburst floods in the Yarlung River in Tibetan Plateau can improve the framework flood sedimentology and chronology. It can also establish event chains of catastrophic floods in mountain area and improve the accuracy of hydraulic models. It is of great significance for analyzing the response of extreme landform processes and disaster assessment.
Key words:high-magnitude outburst flood/
flood landform/
flood sedimentary feature/
hydraulic model/
southeastern Tibetan Plateau
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