Analysis on recent evolvution of main stream of reach from Bengbu to Fushan of Huaihe River

The severe deformation of river course has recently occurred in the reach from Bengbu to Xiangmiao of the main stream of Huaihe River due to the influence of the sand mining;of which the changes of the main channel are more severe than those of the floodplain,i.e.the scouring enlargements occur on most of the main channel,while various changes present on the floodplain along the reach with part of it under the status of slight deposition or equilibrium between scouring and deposition and part of it under the condition of scouring.However,the changes of the reach from Xiangmiao to Fushan are more different from those of the upstream reach.It mainly appears as the natural evolution,the variations of the erosion and deposition of the main channel and the floodplain are less and the river channel is more stable.The measured data show that the natural evolution of river channel of the middle reaches of Huaihe River is slower and the human activities have significant impacts on the evolution of the river channel.