Research On Residential Runoff Scheme Controlled By Drainage System Based On Low Impact Development

Urbanization has changed the conditions of underlying surface and hydrological mechanisms of natural field, which results in deterioration of water environment, waterlogging risks, runoff pollution and loss of rainwater resources. Traditional drainage system cannot meet current requirement of urban sustainable development. An environment-friendly drainage system based on Low Impact Development(LID) shows its advantage. Given the disadvantage of traditional design in drainage system in our country, we need to learn advanced storm water management concept and engineering experience from developed countries. Combined with the actual situation of domestic construction in our country, we have to improve and refine the design of drainage system systematically and study in practical cases. Drainage system based on LID is to restore natural circulation mechanism of water, effectively control urban runoff and protect ecological environment. It has important theoretical significance and practical value to research on drainage system scheme based on LID and simulate its effectiveness, as it can solve problems of urban flood disaster and ecological environment, maintain and promote hydrology cycle as it were.In this paper, a new drainage system based on LID technology was studied and its simulation model originated in SWMM was established. This model was used to assess this drainage system of somewhere in Nanchang.First of all, the problem existing in current residential drainage system was analyzed according to the climate characteristics of Nanchang. The research status of LID and excellent engineering case home and abroad were introduced and analyzed as well.Secondly, the target and principle of this new drainage system were analyzed, and land plan based on LID as well as green infrastructure was studied. The integral design of green land was introduced from 4 aspects, such as size, shape, layout and structure. And then, this study specifically introduced typical designal elements of concave greenbelt, rain garden, filtering belt, vegetation shallow groove, green roofs and penetration pavement. And put forward some suggestions to extend rainwater retention time and ensure water in stranded facilities empty within prescribed time.Finally, SWMM was used to establish an assessment model based on rainfall and soil features of Nanchang. Then this study took a real project in Nanchang as the research object, made a design in it and analyzed different LID schemes to reduce emissions and key factors of it. The cost of these schemes was calculated in order to make LID drainage design system perfect.This study has obtained certain research results. In learning and absorbing advanced storm water management, this paper made a further study of residential drainage system based on LID and improved it in aspects of site planning, connective arrangement and so on. Moreover, it established a new residential runoff simulation model of Nanchang which can provide a source model for similar local project. And life cycle analysis was carried on the pilot project which can provide certain reference value for local similar projects in economic analysis.