Research On Self-balance Pattern Of Waterlogging And Spatial Matching System Of Small Towns In Guanzhong Plain

Guanzhong plain(GZP)is the largest flat area of loess plateau and the largest urban area in western China.GZP has a semi-arid climate where limited precipitation is concentrated in summer but relative dry in winter which induced runoff accumulation in rain season and drought in dry season in this region.In order to adapt to the typical climate,the local people living in the traditional villages and towns of GZP adopt a harmonious stratagem to store and drain runoff by using the spatial arrangement of building and settlement space.However,this stratagem has been gradually eroded by rapid urbanization and expansion of small towns which applied modern urban planning to control the waterlogging problem,such as using underground pipe to drain city runoff.The relative modern drainage system seems to be inadequacy for traditional small towns in GZP which caused frequent waterlogging problem in these small town during rainy season.Meanwhile,as the different level of social-economic condition of these small town in GZP comparing with major city,the waterlogging problem has been aggregated by directly copying modern drainage system,which is usually applied to major cities,with relative lower quality.Therefore,the spatial development of small towns in flat area and the ecological digestion of waterlogging have become an urgent proposition of in China.In this paper,the underlying causes and spatial solutions of waterlogging problem of small cities were analyzed and discussed in the perspective of human settlement environment based on the knowledge of architecture,urban planning and water supply and drainage engineer.Based on relative research methods,such as comprehensive field investigation,statistical analysis,qualitative analysis,scientific abstraction and so on,this paper explores the traditional ecological construction experience of "self-balance" of drought and flood in traditional villages and towns in GZP,and analyzes the derivative mechanism of waterlogging in contemporary small towns.Meanwhile,the ecological balancing model for waterlogging and its spatially matching design for small town in flat areas were proposed in this paper under the system and green infrastructure theories combined with the ecological planning.Finally,the suitable model of town administrative boundaries,built up area,neighborhood area and residential courtyard were experimentally discussed in macro,mid and micro levels.Firstly,this paper conducts qualitative and quantitative research on the settlement distribution pattern of traditional villages and towns in GZP,the composition of underlying surface of villages,the type of courtyard building system,the facilities of drought and flood self-balancing system.Then,we summarize this traditional modes and methods of the villages and towns in GZP to combat with drought and flood problem.A special experiences and pattern in adapting to variation of climate,matching function and energy saving ecology system is summarized and concluded from this series of interrelated but relatively independent spatial coping model system.Secondly,based on the comprehensive analysis of historical evolution and dynamics of natural environment characteristics,residential building type system,architectural group organization and rainwater management facilities,this paper analyzes the derivative mechanism of waterlogging disasters in small towns in GZP,identifies the key factors inducing waterlogging problem and proposes specific stratagem relating to selfbalance system of these small town in GZP to solve this problem..Thirdly,the paper clarifies the mathematical relationship between rainfall,runoff,water and drainage in small towns,determines parameters and control indicators and spatial design indicators related to urban waterlogging,and constructs the four unit of self-balance of waterlogging system,including courtyard house,neighborhood area,town built up area and administrative boundaries.We also propose the self-balancing model of the small towns in GZP which would be a supplement to the theories and methods of small town planning,and would be constructive model which is suitable for the GZP or other small towns in the flat area.Finally,the paper studies the spatial organization of small towns based on the self-balancing model and proposes the target of rainwater utilization and the target of reduction of waterlogging in small towns in GZP.We also design the structure of unit function,control of size,indicator system,spatial organization and facility configuration of each self-balance system units which included the grassroots residential unit of courtyard house,the basic living unit of the neighborhood area,the rainfall-balancing unit of the township and the ecological coordination unit of the town administrative boundaries.Finally,we try to explore the systematic solution for waterlogging and the sustainable development of small towns in GZP.