Change of the three outlets in Jingjiang River and the regulation scheme

The branches from the three outlets to Dongting Lake are not only threatened by the flood of Jingjiang River,but also influenced by the backwater of Dongting Lake.To alleviate the flood pressure of Jingjiang River,the flood of Jingjiang River is diverted to Dongting Lake by the three outlets.In the past fifty years,with the cutoffs of Zhongzhouzi,Shangchewan,Shatanzi and Shishou as well as the impoundment of Gezhouba Project and Three Gorges Project,the riverbed in Jingjiang reach has degraded and the water level of middle and low discharge has obviously lowered.Meanwhile,the branches of the three outlets aggrades gradually due to the decrease of flow and sediment diversion.By analyzing the situation of the three outlets,a scheme about channel regulation for the three outlets and five rivers is presented.