The Research On The Impact Of Urban Green Space System Planning On Sponge City Construction

"The Sponge City"is defined as a city that is like a piece of sponge,which holds favorable “elasticity”to permeate,purify and store up rainwater when it is confronted with environmental change and natural disaster.During the process of urbanization,due to those unreasonable city planning and constructions,the local natural hydrological cycle has been destroyed.This diminished the city's capacity to handle rainstorm water and then resulted in frequent occurrences of a huge variety of city water problems.Corresponding study on the definition of sponge city as well as the urban green space system planning under the sponge city background has been conducted in this paper through relevant literature reference and field survey.And Nanchong City is taken as an example to conduct on-site investigation and specific analysis for the sponge city to illustrate the importance of reasonable planning of urban green space system in responding to the sponge city,and in the meantime,provide materials and references for relevant researches in China.The results of this research are as follows:1.The research summarizes the existent research progress and practice of the sponge city at home and abroad.By comparing with those advanced foreign management concept,technical measures and criterion of rainstorm management,the concept of the sponge city in China has been sorted out and the response planning of urban green space system for sponge city has been further summed up.Besides,through conducting the classified investigation on the current situation of Nanchong as a sponge city and analyzing its present condition and causes,this research presents the sponge city construction oriented city planning strategy and proves its significance and instructiveness.2.The research defines related concepts about urban green space system and probes into the aim of urban green space system planning.Also,a thorough exploration of urban green space system planning for cities with sponge city background has been made in these four aspects,planning principle,planning strategy,control index and spatial arrangement to obtain the significance of reasonable urban green space system planning in city's construction.3.The paper took Nanchong as an example City to conduct investigation and research.The natural terrain,water resources,urban drainage,water pollution,urban water logging,green space conditions,changes in landscape pattern of the main city in Nanchong were investigated respectively,and the investigation and survey results showed that the water resources are lacking,and the spatial and temporal distribution ofwater resources is uneven;Drainage pumping stations are in a severe shortage,and the pipe network system,the layout and standards are not good enough;The surface water quality is organic contamination,and the water quality of Xihe River,which flows through Shunqing urban area,is severely polluted,and the water quality of the main stream of the Jialing River is basically stable;There are 18 places which suffer from serious waterlogging in the main urban area of ??Nanchong,with an accumulated water depth of 15 to 40 cm,and the main reason is that the terrain of Nanchong is relatively low and the drainage facilities are not enough;The total area of ??green land in Nanchong is 15,946,900 square meters,which occupies 13.29% of the whole area,the green coverage is 35%,and the green space per capita is 6 square meters,and the green land is not enough,the distribution is uneven and edge damage of the green land is serious;The data of the landscape pattern in the main urban area of??Nanchong indicates that all of the natural geography,climate,population,economy,policy,and plant planning have an impact on the change of urban landscape pattern.4.Against the problems and insufficiencies in the investigation,and based on the overall planning of Nanchong and under the background of sponge city building,this paper proposed the planning analysis aiming at improving the drainage conditions,water pollution,water logging,green space conditions,and landscape pattern change in the main urban area in Nanchong.5.With the investigation and analysis of the sponge city building situation in Nanchong,planning strategies for the sponge city building in the urban area are proposed in this paper.Firstly,carry out the construction plan of the city from the whole to the local through the source,middle and the end control of the rainwater flow.Meanwhile,planning conceptions upon urban green space systems are put forward in 3aspects: the planning and principles,planning layout and structure,and the introduction of low-impact development facilities.Secondly,the Wenfeng park in Wenfeng district is taken as a study object through the comparative analysis of those places where waterlogging has been successfully governed.The overall planning,plant allocation,material utilization,and LID facilities of Wenfeng Park were investigated,mapped on-site and described in detail.Then,the methods and feasibilities of carrying out urban green space systems planning through the control of rainwater runoff under the background of sponge city building were concluded through the analysis.