长江中下游流域极端洪水事件影响机制研究

Research on the Dominant Mechanism of Extreme Flow Events in the Middle and Lower Reaches of the Yangtze River

以洪水为例的极端事件给社会带来了严重的生态影响和巨大的经济损失,但是这些极端事件的影响机制并未完全掌握,以长江流域为研究区域,选取了长江流域224个水文站的流量数据,以及247个气象站所测的气象数据和蒸发数据。以降水和土壤蓄水量作为洪水驱动力进行分析洪水发生的主导机制。结果表明:极端降雨事件和极端洪水事件主要发生在5月到8月,并且不同流域的极端事件发生时间与纬度有关。对于极端洪水的影响机制,不同区域存在不同的主导因子,并且主导因子与流域面积之间有一定的相关性。

Extreme events such as floods have brought serious ecological impacts and huge economic losses to our society,but the mechanism of these extreme events has not been fully understood.This paper takes the Yangtze River basin as the research area,and selects discharge data from 224 hydrological stations,and meteorological data measured at 247 meteorological stations in the Yangtze River Basin.Extreme precipitation and soil water storage are taken as flood driving forces.Our results show that both extreme rainfall events and floods occur from May to August,and the occurrence time of extreme events in different watersheds is related to latitude.For the dominant mechanism of floods,there are different dominant drivers in different regions,and there is a certain correlation between the dominant factors and the basin area.