Antecedent snowmelt and orographic precipitation contributions to water supply of Pakistan disastrous floods,2022  

作　　者：Yan WANG Peng CUI Chen-Di ZHANG Guo-Tao ZHANG Jian-Sheng HAO Xu YUAN Yao-Zhi JIANG Lu WANG 

机构地区：[1]Key Laboratory of Land Surface Pattern and Simulation,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China [2]Key Laboratory of Mountain Hazards and Earth Surface Process,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610299,China [3]Polar and Marine Research Institute,College of Harbor and Coastal Engineering,Jimei University,Xiamen 361021,China [4]School of Resources and Environment,University of Electronic Science and Technology of China,Chengdu 610054,China [5]Hebei Province Tangshan Caofeidian Meteorological Bureau,Tangshan 063000,China

出　　处：《Advances in Climate Change Research》2024年第3期419-430,共12页气候变化研究进展（英文版）

基　　金：the Second Tibet Plateau Scientific Expedition and Research Program(STEP)(2019QZKK0903-02 and 2019QZKK0906);the National Science Foundation of China(42371085).

摘　　要：In 2022,the Pakistan witnessed the hottest spring and wettest summer in history.And devastating floods inundated a large portion of Pakistan and caused enormous damages.However,the primary water source and its contributions to these unprecedented floods remain unclear.Based on the reservoir inflow measurements,Multi-Source Weighted-Ensemble Precipitation(MSWEP),the fifth generation ECMWF atmospheric reanalysis(ERA5)products,this study quantified the contributions of monsoon precipitation,antecedent snow-melts,and orographic precipitation enhancement to floods in Pakistan.We found that the Indus experienced at least four inflow up-rushes,which was mainly supplied by precipitation and snowmelt;In upper Indus,abnormally high temperature continued to influence the whole summer and lead to large amounts of snowmelts which not only was a key water supply to the flood but also provided favorable soil moisture conditions for the latter precipitation.Before July,the snowmelt has higher contributions than the precipitation to the streamflow of Indus River,with contribution value of more than 60%.Moreover,the snowmelt could still supply 20%-40%water to the lower Indus in July and August;The leading driver of 2022 mega-floods over the southern Pakistan in July and August was dominated by the precipitation,where terrain disturbance induced precipitation account to approximately 33%over the southern Pakistan.The results help to understand the mechanisms of flood formation,and to better predict future flood risks over complex terrain regions.

关 键 词：Extreme heavy rainfall SNOWMELT Orographic precipitation Floods Pakistan 

分 类 号：P33[天文地球—水文科学]