| In recent years,extreme climate is common.Almost every summer in China,there will be flood or urban waterlogging,which has a great impact on social and economic development and the life and safety of citizens.In order to solve the problems of urban flood and urban waterlogging,China has been continuously promoting the planning and construction of "sponge city" since 2013.In a few years,many sponge projects have been built.However,in the face of heavy rain,the resilience of sponge city is insufficient,and waterlogging still cannot be avoided.Although a large number of studies show that urban green space has a strong capacity of rain and flood regulation and storage,but in the face of the general facts of iron,it still can not escape the doubts of the public on green space and sponge city.According to this,this paper will take the urban green space as the quantitative research object,analyze the storage capacity of the green space,analyze the reasons of its storage efficiency combined with the actual rainfall situation,and propose how to make the green space play its role fully.The research summarizes the relevant research progress at home and abroad from the aspects of rain flood management,rain flood model and green space storage,puts forward the quantitative evaluation idea of the storage efficiency of urban green space,and finally obtains the classification of the comprehensive storage efficiency of urban green space.The results show that the storage efficiency of urban green space in Shenyang is mostly determined by its own storage capacity,but also affected by external factors such as surrounding development intensity and hardening coverage.Further analysis shows that if the surface soil is dry in summer and there is less rainfall in the five days before the rainstorm,the green space can retain an additional 28% of the external runoff under the rainfall;however,with the extension of rainfall duration,the vegetation interception and surface soil water storage will not increase any more,and the role of deeper soil is needed,so it is very important to increase the spatial connection of green space and improve the surface permeability of green space.Finally,the paper puts forward different optimization strategies and suggestions from three aspects of urban area-catchment area-land classification,forming a green space optimization system consisting of urban green space system-catchment area classification management and control-land use unit technical measures.It provides the basis for urban green space system planning and sponge city construction. |
