Risk Analysis On The Embankment Of The Yellow River And The Flood Impact Assessment In NingXia

Embankment section of the Yellow River in Ningxia is floods and ice floods Disaster-prone area,it has different degrees of floods and ice disasters almost every year,especially the embankments of river regulation projects area.Although after a lot of governance,it still exist many risks because of the embankment factors and external factors.Therefore,it is necessary to adopt scientific methods to make risk comprehensive evaluation for these embankments near main renovation projects,then choose some of the highest risk embankment segments to conduct risk analysis of dike burst flood.In this paper,the main research results were as follows:(1)Based on the characteristics of Yellow River Embankment in Ningxia,this paper establishes the risk evaluation index system of the embankment project of the Yellow river in Ningxia from these perspectives of embankment itself and flood risk.(2)This paper takes the embankment risk evaluation index as the multitiered construction system based on the characteristic of stractification and dynamics of the embankment project of the Yellow river in Ningxia.On the basis of field investigation and expert evaluation,it uses the analytic hierarchy process proceeding risk comprehensive evaluation for typical embankment projects on the left bank of Weining,right bank of Weight,left bank Qingshi and right bank of Qingshi.(3)According to the results of comprehensive evaluation,we select the highest risk embankment project on the left bank of Weining as the breach area and set up the one-dimensional(from the channel of the Yellow River)and the two-dimensional(from the flood protection zone in the north of the Yellow River in zhongwei)coupling hydrodynamic model.What's more,the model was improved by using dry depth and wet depth judgment theory,setting roughness by region and controlling breach change gradually.(4)The optimized model is used to simulate the scene that flood protection zone in the north of the Yellow River in Zhongwei encounters one hundred year flood of Yellow River.According to the simulation result,we carry out the flood risk analysis.(5)After a deep analysis of statistics of the affected social and economic data and evaluation methods of losses caused by the flood,the flood impact assessment upon the flood protection zone in the north of the Yellow River in Zhongwei is conducted.