Urban Rainwater Characteristic Response To Low-impact Development Techniques

With the acceleration of urbanization process in China, flood control which caused by precipitation is increasing prominent in urban interior, more over,drainage waterlogging and urban non-point source pollution control has become an important part which is faced by the construction of many cities. Underlying reconstruction and drainage system optimization is the fundamental way to solve the urban waterlogging, but also an important means of pollution control surface sources. Comprehensive features many types of underlying surface runoff, pollutant transport characteristics and hydraulic characteristics of the model analysis, technology has become an important means to solve the problem of urban stormwater management. Based on Low Impact Development(Low impact development, LID) technology concepts, the study build a model of stormwater pollutant load model coupled Beaulieu District of Baoji City which computing with the Storm and Flood Management Model(Storm Water Management Model, SWMM),Study transformation on the pad surface rainwater and point source pollution, and aims to provide an effective technical means for the planning and construction of urban development in the Northwest, the specific results are as follows:1、Build the model through the model parameters were determined suitable with Panlong District of Baoji City area terrain and the control of runoff contaminate, and by numerical simulation flow and pollution load discharge port and other testing the model utility in the study area, its simulation accuracy error of less than 11% can be achieved.2、Analysing the result of the city’s old programming and poor drainage pipe section water main points,pipe network design standard bring up to two years,its flow capacity can’t meet the demand of the existing rainfall.Adding LID facility in the original drainage system with the model calibration,the study observes that only added small drainage network control facility can spread,abatement section rain and improve the existing urban waterlogging problem without changing the original drainage network also reproduce the original design of the drainage system from 1 year to 2 years,more over it can effectively reduces the pollutant load which is carried by runoff.3、When the drainage network suffered five years of a rainstorm, part of the tube segment is still unable to meet the flow requirements, so we propose to provide stormwater storage tank to collect rainwater for urban road spray, greening and landscape irrigation water after the initial treatment,in order to prevent flood disaster occur.