Study On The Problem Of Evaluating The Flood-Control Influence Of Engineering Project Of Enclosing Sea Area To Make Land In The River Mouth Of New Yongding River

These days in our country more and more construction projects are built inside the river channel, which could bring more and more great influence for the flood management of the river channel. Therefore, the suggestions of building a effective way to evaluate the flood control influence of the river channel construction projects are put forward in this paper, some contends and methods and approach of the flood control evaluation are discussed. Based on introducing theories of the flood simulation, complete hydrological and hydraulic method of the river flood routing is particularly expounded. And the mathematic model of the river flood routing is built up. Otherwise this paper introduced various flood simulating software of wildly applying in the world in detail, and gave emphasis to researching HEC-RAS.Based on academic researching, taking the engineering project of enclosing sea area to make land in the river mouth of new Yongding River as an example, this paper analyzed physical geography and flood-control capability of the valley of new Yongding River .After that, the most important problem of the influence on flood control, which is to figure out the raised water level in the river way by the constructions, was analyzed by the hydraulic mathematic model. Making use of designing water level and runoff, the model was validated. The results show that the raised water level is too little by the constructions of this engineering project, it almost has no effect on the flood control of the new Yongding River and neighborhood.