Study On The Rain Water System Revamp And Optimization In Pu Town Shaanxi Province

The urbanization progress faster and faster, with frequent extreme heavy rain events in recent years has caused many serious urban waterlogging phenomenon.It reflects that the urban pipe network system design is not reasonable.Now the layout of pipe network is difficult to deal with sudden heavy rain events and it has brought a serious threaten to people’s life and financial loss. Therefore, it is necessary to take measures and technical means of more advanced design to conducted to the treats of urban rainfall,and the measures must be reasonable and correct.And it may provides scientific basis for reasonable planning to prevent the urban disaster. Now, the development of computer technology is more and more mature, the establishment of the mathematical model has been proven to reliably solve various problems of rainwater pipe network in urban planning.In this artical,I introduced the rain flood control system model,which includs the model of the basic theory, structure and application situation. I also analyzed the SWMM non-spot applicability of the model and compared the rain flood model which are common used on the international. This text discusses the theory of SWMM simulation software methods and simulation steps, including generalized sub basin, LID selection and operation steps of control. The parameters of the model are calibrated for many times and the model meet the actual situation of the region.Questions such as the urban water accumulation that caused by the urban waterlogging have influenced the people’s normal life. Taken a town in Hanzhong city Shananxi Province as an example, the designed rainfall process is defined on the basis of analysis of typical rainfall process by Chicago Rainfall Line. SWMM modelsystem is adopted to devide subcatchment area, generalize pipeline network and streamline parameters to establish the rainfall flood model. A LID control scheme is designed to simulate rainfall floods when the rainstorm return periods are one year,three years,five years and ten years. The result show that adopting water permeable bricks and sunken green space to revamp underlying layers will effectively reduce the rainfall peak flow, on the other hand the same area green space which deployed at downstream or upstream hasthe same reduction rate for peak rainfall flow, however deploying at downstream will delay the arrival of rainfall peak.Through the establishment of SWMM model in this region,the drainage pipe network visualization becomes possible, it becomes accurately and timely to find the "bottleneck" of drainage pipe network. Specific feasible retrofit scheme was proposed,which includes changing the node height and diameter.The simulation results show that the scheme is feasible.The drainage pipeline should be fully considered when designed and must be considered reasonably to set to reduce the pressure of the main drainage pipeline.The branches of the pipeline should not have overflow occur and should more share the task of rainwater collection, and then discharge through multiple channels.The main pipeline should decorate a more,but But when it cannot achieve we can Appropriately enlarge the diameter to deal with a sudden heavy rain.