Application Of Swmm Model Based On Arcgis In Sponge City Planning

In recent years,with the continuous development of city,the hardening area ofthe underlying surface of the city has increased,and the problems of frequent urban flooding,serious water pollution,water shortage,and insufficient utilization of rainwater resources have become more and more prominent.The natural hydrological cycle has been broken,leading to serious guilt and non-point source pollution problems.The drawbacks of traditional rainwater management measures become more and more obvious.In order to cope with the frequent urban flood disasters and the pollution of storm water runoff,the construction of “sponge city” rainwater management concept was proposed,with the low impact development as the connotation of the sponge city.This paper attempts to use the SWMM model to simulate the typical urban planning scheme in the northwest region and get the best planning solution.Through the hydraulic model software,the assessment of the drainage capacity of the Qinhan city,the risk assessment of the intrinsic risk,and the evaluation of the flood control planning system of each river basin were carried out.The model was verified from the direction of planning with reference to the core flow control rate.In addition,on the basis of this,the typical land parcels in the study area are selected,and the total runoff control target is decomposed and calculated,and the sponge type of each block is finally determined.What`s more,it is intended to provide reference for the planning of sponge cities in the arid and semi-arid regions of Northwest China.In recent years,with the continuous development of city,the hardening area ofthe underlying surface of the city has increased,and the problems of frequent urban flooding,serious water pollution,water shortage,and insufficient utilization of rainwater resources have become more and more prominent.The natural hydrological cycle has been broken,leading to serious guilt and non-point source pollution problems.The drawbacks of traditional rainwater management measures become more and more obvious.In order to cope with the frequent urban flood disasters and the pollution of storm water runoff,the construction of “sponge city” rainwater management concept was proposed,with the low impact development as the connotation of the sponge city.This paper attempts to use the SWMM model to simulate the typical urban planning scheme in the northwest region and get the best planning solution.Through the hydraulic model software,the assessment of the drainage capacity of the Qinhan city,the risk assessment of the intrinsic risk,and the evaluation of the flood control planning system of each river basin were carried out.The model was verified from the direction of planning with reference to the core flow control rate.In addition,on the basis of this,the typical land parcels in the study area are selected,and the total runoff control target is decomposed and calculated,and the sponge type of each block is finally determined.What`s more,it is intended to provide reference for the planning of sponge cities in the arid and semi-arid regions of Northwest China.The construction of sponge city involves many aspects such as water environment,water safety,water ecology,water resources and construction cost.The paper is based on the topographical topography,hydrological and climatic characteristics,soil conditions,rainwater system and land use type of typical areas based on Arc GIS platform.According to the guiding principles and the combination of the target requirements of the construction of the sponge city in the study area and the current situation of the construction of the Qinhan city,this paper proposes a standard value for the total amount of rainwater runoff suitable for the typical region,and builds a SWMM model based on the Arc GIS research area.The platform,selecting resources,runoff,geology,and ecological factors as sensitive indices and coupling analysis,determined the comprehensive water security pattern of the study area.Then,the current situation model of the study area was established by SWMM.On this basis,according to the requirements of the annual runoff total control rate,the scale of the sponge facility needs to be set.The model and field investigation are used to determine the location of the sponge facility,and several sets of combined sponge facilities that meet the conditions are proposed.The total runoff index is decomposed into each control unit of Qinhan city.According to the annual control of the total runoff control rate of each control unit,the annual total runoff control rate of Qinhan city is 80.1%,and 80% of annual runoff is achieved.Target requirements for volume control rate.The planning and design plan realizes the whole process of rainwater control through the source control,the mid-way delay,the end regulation and the combination of the rainwater pipe network and the engineering measures of the river channel,and realizes the drainage flood control standard requirements of the study area.The selected area in this paper is located in the collapsible area,and the collapsible less area is fully considered in the planning scheme due to its special soil geological conditions.The construction of sponge city in the area should fully consider the damage.Adopt a reasonable,effective and suitable LID facility in the region and establish a targeted scientific evaluation system.