Simulation Study On Rainwater System In Alpine Region Based On S WMM

In recent years,the extreme weather in the world has caused heavy rains and heavy rains to occur frequently.Under the background of increasing urbanization level and expanding urban scale,the harm and impact caused by urban floods reveal the contradiction between municipal infrastructure construction and safety guarantee.Urban construction not only needs a perfect rainwater pipeline system,but also has the ability to store floods,flood discharges and ecological restoration.The effective management of urban flooding problems is urgent.This topic will change the traditional urban rainwater disposal concept,solve the hidden dangers of urban rainwater,and consider the landscape and functional requirements of urban planning,and develop a set of urban environmental optimization design scheme based on rainwater management.Therefore,it is urgent to integrate advanced rainwater management concepts into the design and management of urban stormwater systems to meet the rapid development needs of cities,based on the existing sponge city,look for a set of rainwater disposal measures suitable for cold areas in high latitudes.This topic selects a high-latitude cold region as the research area,and the meteorological and hydrological conditions are extremely important representative.Based on the advanced foreign stormwater management experience and concept,combined with the research progress of China's stormwater management,the study area rainwater The current status of the system proposes the goal of total runoff control,which is conducive to the construction and development of China's sponge city in high latitude cold regions.Based on the climatic characteristics of cold regions in high latitudes,this study selects the research areas with typical characteristics,collects relevant data,and analyzes the flood control and drainage situation of the current state of the rainwater system from the aspects of rainwater system status,precipitation characteristics and internal causes.According to the sponge city construction guidelines and related norms,the planning period and low impact development(LID)transformation plan were selected to achieve the goal of transforming the sponge city in the study area.Through the analysis of the underlying surface of the study area,from the perspective of the combination of infiltration and storage functions,a rainwater system retrofit scheme for cold regions at high latitudes was developed.The ground elevation map,rainwater system and land use data of the study area were collected.Through the spatial analysis technology of ArcGIS,the SWMM hydraulic model was constructed by generalizing the rainwater system,dividing the sub-catchment area and analyzing the slope.Based on the SWMM model,the flood model process of the target block was established,and the flooding process was carried out for the rainfall scenarios with different precipitation periods,duration of 120 min and rain peak coefficient of 0.395,which were synthesized by the storm intensity formula and the Chicago rainfall process line.Its risk assessment study.Three different rainfall scenarios were set,and P=5a,10a,and 20a were taken to compare the different effects of the same sponge city reconstruction scheme under different rainfall scenarios.The research results show that the LID measures play a big role.Compared with the reform,the rainwater system can fully meet the return period rainfall when P=5a.When the return period increases,although the storage retention capacity of the LID facilities is close.It is saturated,but the improvement of the rainwater system in high-latitude cold regions still has a significant effect.