Improvement of Flood Control over Dongting Lake & Jingjiang Stretch by Clean Water from TGP

With impoundment of the Three Gorges reservoir and subsequent construction of major hydro projects on the Jinsha River, the Three Gorges reservoir will discharge clean water with less sediment over a long period of time, which implies the middle reach of the Yangtze River will become essentially a new alluvial stream. Heavily scouring of the Jingjiang stretch resulting from the clean water could have significant impact on the levees, river morphology, navigation course and flood defense along the Jingjiang stretch. By proper usage, however, this clean water having powerful scouring force could also improve the flood control situation of the middle and downstream reaches of the Yangtze River. A recommendation is made in this paper, i. e. , increase in clean water diverted from the Yangtze River to the Dongting Lake, which could avoid excessively sourcing the Jingjiang stretch and on the other hand, could scour such key locations along the Lake that flood control conditions in the lake area can be improved and enhance scouring of the Yangtze River downstream of Chenglingji.