Use the flood years (1998、2010) the data of the hydrologic information and disaster information, comparative analysis the impact on hydrologic information and disaster information in Dongting Lake area of the Three Gorges Reservoir flood prevention dispatching .The results show that: the inflow of lake into Jingjiang Sankou reduces about 242.61 × 108 m3,the flood level of Hukou Chenglingji lowers 0.82m, the daily average increasing rate of flood peak level slows 0.23m, the over-warning water level duration time reduces 62d; both have saved a great deal of flood control emergency rescue and disaster relief material consumption, manpower input, namely RMB 0.638 x 108yuan, and reduce the lake area flood damage 19.983 x 108yuan; in the process of 5 times flood prevention dispatching of the Three Gorges Reservoir, three times in July to alleviate flood control operation regime, disaster in Dongting Lake area the contribution of the largest, flood control operation effect is not very sensitive in June, and the impound floodwater sums to 80.7×108m3, not only of the lake area is no sense of flood control, but also because the flood retention of reservoir is more, the water of Sankou into the lake is greatly reduced, and Hunan sishui has begun to enter withered period, total amount into the lake gradually reduce, make the Dongting Lake water into withered period early; the ability of the Three Gorges Reservoir flood prevention dispatching operation to the flood prevention function is very limited, from the overall and long-term ways ,to enhance their ability of flood prevention and disaster alleviation of Dongting Lake area is still an important and comprehensive affairs.
Influence of Large Reservoir Operation on Water-Levels and Flows in Reaches below Dam: Case Study of the Three Gorges Reservoir
