Ecological Suitability Evaluation Of Sponge City Based On RS/GIS

With the research and development of sponge city planning and construction in China,the evaluation method of urban ecological status represented by environmental impact assessment is widely used in sponge city construction.Based on the theory of ecological suitability evaluation and sponge city construction,this paper analyzes the land use status and urban waterlogging risk in the study area based on RS/GIS.The ecological suitability evaluation of sponge city construction in the Shiwuli River basin is carried out by using the combination of AHP and entropy weight method by using the indicators of NDVI,distance from water body and current situation of annual runoff control rate.According to the evaluation results,this paper puts forward the optimization direction of sponge city construction from five aspects of planning,construction,acceptance,project supervision and emergency mechanism establishment.The following conclusions are obtained.(1)Sponge city construction is an important engineering measure to control the urban environment.The sponge city construction planning of the Shiwuli River Basin conforms to the ecological suitability evaluation of the region.Among them,the upper reaches of the Shiwuli River is not suitable for engineering construction,so the reconstruction of storage tank and small-scale permeable pavement are the main measures.The middle reaches have a certain ecological basis to dredge the river.The construction of ecological wetland park is the most suitable area for sponge city construction.The lower reaches have a good ecological foundation,which is also the most suitable area for ecological governance.Improve the standard of environmental governance under the original ecological conditions.Among them,the most suitable area for sponge city construction is 17.75km~2,accounting for 15.96%;the area suitable for sponge city construction is 77.68km~2,accounting for 69.83%;the critical suitable area for sponge city construction is 12.76km~2,accounting for 11.47%;the area not suitable for sponge city construction accounts for only 2.74%.(2)Aiming at the planning and construction of sponge City,this paper puts forward optimization measures from five aspects of planning,construction,acceptance,supervision and management,and emergency mechanism.The importance of public participation and supervision in sponge city planning and construction is emphasized.The ecological suitability evaluation of sponge city shows that each ecological environment factor does not exist alone.Urban ecological environment is a systematic whole,and there are internal relations among different ecological factors.The construction of sponge city should focus on the whole process control mechanism of planning facilities to deal with rain and flood.The whole process of rainwater drainage,storage and purification is planned in a unified way,and the regional environmental management work is carried out in a systematic principle.