Study On Hydraulic Optimization Of Xuecheng Xiaoshahe Constructed Wetland

Nansi Lake is one of the largest lake in north of our nation, and it is also the certain way for the great project that diverts the water from south to north. So the water quality of Nansi Lake is the most crucial factor which leads the project to success or failure. Xuecheng Xiaosha River, as an inflow river of Nansi Lake, its water quality is one of the keys to divert water successfully in the eastern route of the south-to-north water diversion project. The experimental research on the constructed wetland at the entrance of Xuecheng Xiaosha River based on the pollution control planning of EPR was implemented. Xuecheng Xiaoshahe constructed wetland covers an area of 886.545 acres. Aimed at the hydraulic flow regime of Xuecheng Xiaoshahe constructed wetland, the study begins.At home and abroad, there are so many water environment mathematic models, after carefully selected, two-dimensional flow-pollutant coupled model is selected to use in this thesis. With Surface water Modeling System, the research simulates flow field and concentration field of Xuecheng Xiaoshahe constructed wetland by finite element method. Through the research on simulation of different outlets, conclusions are listed as follows:1, Flow regime and hydraulic property is a principal element to maintain the normal operation of constructed wetland system and play an important part in decontaminating. The flow regime of constructed wetland system is between plug flow and completely mixed flow.2, Constructed wetland system has detention area and the short-stream phenomenon, there are some untapped areas in the wetland. The choice of outlet location has greater influence on hydraulic flow regime, the rational design of outlet location is favorable to make the most of wetland area, it can avoid"short circuit".3, By simulating and analysis the six options, we can draw a conclusion that option 2 is relatively good in three separate water outlet options and option 4 is relatively good in three joint water outlet options.The study on simulation of hydraulic flow regime of Xuecheng Xiaoshahe constructed wetland could provide a theoretical basis for the rational design and running of constructed wetland. The data and conclusions of this study, has instructional significance to the operation and management of the practical constructed wetland project.