GUO Shenglian, XIONG Feng, WANG Jun, ZHONG Yixuan, TIAN Jing and YIN Jiabo
Abstract: Considering the impact of joint operation of reservoir group in the upper Yangtze River basin on Three Gorges Reservoir (TGR), the most likely regional composition and typical-year methods were adopted to derive the flood regional composition for each control hydrological station. The multi-inputs single-output (MISO) model was used to simulate the flood process between Xiangjiaba and TGR uncontrolled inter-basin. The design floods as well as the flood control water level of TGR during operation period are derived and analyzed. It is shown that:(1) the design floods of downstream reservoirs are significantly influenced by the operation of upstream reservoirs, particularly the cascade reservoirs in Jinsha River;(2) The 1000-year design peak discharge, 3d, 7d, 15d and 30d flood volumes of TGR are 81136 m3/s, 18.8, 38.6,72.7,132.1 billion m3,decreasing by 18.2%,23.8%,20.6%,20.2% and 16.9%,respectively;(3) the flood control (limited) water levels of TGR are 155m (145m) without reducing the original flood prevention standards. The high flood control water level during TGR operation period can not only benefit navigation in the reservoir, sustain reservoir bank stability, and protect eco-environment of reservoir riparian zone, but also can increase hydropower generation, reduce the impact on downstream Dongting and Poyang Lakes during reservoir refill operation period,which has great social-economic and eco-environment benefits.
Keywords: three gorges reservoir; operation period; design flood; most likely regional composition; flood limited water level; flood control water level
