Study On Sponge City Planning In Qujiang New District Based On The Experience Of Stormwater Management In Xi’an Ancient City

With the acceleration of urbanization,the urban water problem has attracted more and more attention.The solution proposed in China is to build "sponge city",but the current system has been implemented for a short time,and is derived from foreign research and practice,so there is still room for improvement in localization.On the contrary,the ancient Chinese city construction,adhering to the concept of respecting nature and making the best of the situation,found out a set of effective stormwater management methods in the process of fighting against flood disasters.Starting from the construction of sponge city planning system tailored to local conditions,this paper selects the stormwater management system construction in the Western Zhou,Qin,Han,Sui and Tang dynasties of ancient Xi’an as a typical case for study.With the help of historical materials and related studies,The function of stormwater management system in ancient Xi’an is studied from the aspects of city site selection,city layout and vertical design,water system pattern,landscaping and water culture.It is concluded that ancient Xi’an has constructed a complete,comprehensive,ecological and three-dimensional stormwater management system.At the same time,according to historical records,the application of this system is not completely secure,and the urban waterlogging problem still exists.This paper innovatively uses the hydrological analysis software SWMM to conduct quantitative research on the causes of waterlogging in Tang Chang ’an,and finds out the reasons why the scale of flood control facilities is not in place.Learning from each other’s strong points,combining the ancient system studied above with the modern sponge city study,the ancient system can provide experience for modern construction in terms of terrain treatment,stormwater pattern shaping,multi-functional construction and local conditions,and modern means can enhance the scientific design.Inherit and innovate,explore the construction of contemporary sponge city planning system based on the experience of ancient stormwater management.Based on the basic situation and current urban construction situation of Xi’an,the paper sorts out the key and difficult points of sponge city construction.Based on the previous research,the paper puts forward the solution ideas and planning principles,establishes the technical route,and puts forward the design strategy of macroscopic-meso-micro.From a macro perspective,through tracing the historical sponge pattern and ecological conditions,the adverse factors for urban construction are avoided.Analyze the ecological background conditions,protect,maintain and restore the ecological elements that have a significant impact on the regional water environment,and construct the sponge ecological pattern suitable for the regional natural environment;At the middle level,the sponge pattern proposed by the upper level is implemented through the two main natural systems in the sponge city construction,namely the urban water system and the greening system.The micro-design focuses on the prominent collapsible loess problem and the protection of historical sites in this area.Based on the existing practical experience and research in similar areas,the design method of low-impact development measures and the inheritance strategy of water culture are proposed.Finally,this system is put into practice in the sponge city design of Qujiang New Area,focusing on sorting out the historical sponge pattern of the area,and using multi-factor analysis method,assisted by Arc GIS software analysis,the sponge pattern at the macro level is obtained to guide the construction.In addition,the paper puts forward the idea of restoring the historical scene of the Yellow Canal and Qujiang Pitch,and the restoration of the Yellow Canal can effectively improve the rainwater regulation ability of the region.Due to the current situation of urban construction and the extinction of historical sites,the hydrological function of the Yellow Canal can be replaced by artificial facilities assisted by natural system.At the micro level,the design method of sponge-type park and road is proposed through examples.At the end of the paper,some suggestions on the future direction of improving the sponge city theory and developing the sponge city technology are given.