Mechanism Research Of Water & Sediment Load Variation Impact On Transversal Profile In Jianli River Reach

Changjiang river,the longest river in our country,played an importmant role strategically in social and economic sustainable development. Since the founding of new China,to develop and utilize the abundant water resources in Changjiang river,many large-scale water conservancy projects were built in the mainstream and tributaries.These projects are so beneficial,and in the same time,changed the hydrological conditions for the downstream river reaches.The river bed configuration's response to the variation of water and sediment conditions,has been an focus for many researchers.In this paper,on the basis of summing up the previous research works,typical river reach-Jianli river reach was selected to analyze the transversal profile's response to the water and sediment load variation,and mainly include:(1) The changes in law of water and sediment conditions in Jianli river reach were analyzed systematically,including the annual changes and annual distribution,the correlations of water and sediment,affecting factors and the variation trends.In addition,the water and sediment characteristics of upper hydrological stations,such as Yichang,Zhicheng stations,and of three branches of Jingjiang river reach were also analyzed briefly.(2) The river bed evolution,especially the transversal profile of Jianli river reach was analyzed since 1980s.(3) The water and sediment affecting factors on river bed configuration were selected,and through analyzing correlation between water and sediment condition in the previous term and transversal profile index,the optimized affecting factors were determined.(4) As an example,Jianli fork river section was used to analyze response mechanism of transversal profile to water and sediment load variation. Standardized multiple linear regression equations were established to determine the relative contribution of each optimized affecting factors.(5) In the end,the variation trend of transversal profile in Jianli river reach was predicted,and also,the regulation measures of Jianli river reach were advised.