Research On The Construction And Optimization Strategy Of The Suitability Evaluation System Of Urban Green Space Sponge

According to statistics,since 1978-2018,China's urbanization process has accelerated,the area of urban construction land has been expanding,natural underwater surface has been encroached,and the city's impervious surface has increased,blocking the natural rainwater cycle and causing urban water.A series of urban problems such as shortage of resources,serious water pollution,declining water ecological functions,and frequent urban floods.In order to alleviate the water environment problems such as floods in the city,China has vigorously promoted the construction of sponge cities.Based on the research on the development history,practice of the sponge city concept,and the research on the urban green space optimization.This paper takes the Yingxiong Mountain-Qili Mountain Area of Jinan City as an example to research the suitability evaluation and optimization strategy of urban green space sponge.According to the classification of green space in urban construction land in the ?Urban Green Space Classification Standard?(CJJ/T85-2017),the Delphi method and the analytic hierarchy process are used to construct the sponge suitability evaluation index system for urban park green space,urban protective green space,urban square land and urban affiliated green space.The sponge suitability of four types of urban green space in the Yingxiong Mountain-Qili Mountain Area of Jinan City was evaluated.Based on the results of sponge suitability evaluation of four types of urban green space,the design guidance strategy of urban green space sponge construction on regional scale and site scale is proposed.The main conclusions of this research are as follows:(1)During the construction of urban green space sponge suitability evaluation system,it is found that the internal and external factors of urban green space have different effects on the suitability of four types of urban green space sponges.The suitability evaluation of urban park green space sponge is greatly affected by the internal factors of green space,and the external factors of urban protective green space have greater influence on the suitability evaluation of urban protective green space sponge.Therefore,the coincidence degree of index factors in the evaluation index system of four types of urban green space sponges is reduced.(2)During the evaluation of the suitability of urban green space sponges,it was found that the four types of urban green space rainwater management capacity from high to low are: urban park green space > urban affiliated green space > urban square land > urban protective green space.In the comprehensive evaluation results of urban green space sponge suitability,the suitable sponge construction areas are concentrated in the urban park green space type,and the suitable sponge construction areas are concentrated in the urban affiliated green space type.The space distribution that is less suitable for sponge construction area and unsuitable sponge construction area is more dispersed.(3)On the regional scale,the planning guidance strategy of urban green space sponge optimization and the optimization design transformation strategy of urban green space sponge on the site scale are proposed.The sponge optimization planning guidance strategy proposed on the regional scale has been verified that the suitable sponge construction area and the suitable sponge construction area optimization strategy have the effect of rain and flood regulation,and the rainwater runoff and peak flow are optimized after the optimization and suitable sponge construction area is completed.The reduction effect is more significant.