Quantifying the Impact of Cascade Reservoirs on Streamflow, Drought, and Flood in the Jinsha River Basin

The Jinsha River Basin (JRB) is the largest hydropower base in China, serving as main source of Western Route China’s South-to-North Water Diversion Project. Under influence reservoirs operation and climate change, general hydrological regime JRB has been altered. Although change process can be determined through a runoff time-series analysis simulation, individual impacts have not quantified. This study aimed to clarify impact on runoff, flood, drought processes using framework coupling long short-term memory (LSTM) flood assessment techniques. results are follows: (1) From 1998 2020, changed average daily at Pingshan Station by −5.64%, +10.95%, −10.93% annual seasonal (dry rainy) scales, respectively. (2) dams reduces risk disasters effectively. Compared with natural river flow, frequency decreased 7.69%, total flow over threshold was reduced 37.86%. (3) duration severity drought, reducing extreme increasing moderate severe drought. In conclusion, positive effects water resource regulation, their mitigation floods provides security for middle lower reaches Yangtze River. reference LSTM modeling reservoir basins, quantifying JRB.