Planning And Design Of Rainwater Corridors In Hilly Areas Of South China Based On Surface Runoff Conservation

With the development of ecological civilization,ecological construction has become the main direction of urban development,and the harmonious relationship between nature and cities has attracted more and more attention.As a key element of natural water cycle,rainwater should be an important consideration in urban planning against the background of frequent flood disasters nowadays.However,in the construction of modern rainwater drainage system,the stress is laid on pipeline network engineering with the goal of draining rainwater from urban area,and little attention is paid to the rain naturalization process.Meanwhile,in the process of rapid urbanization,the extensive construction way of "blindly removing hills and filling water zones" which is commonly used in hilly areas has resulted in destroyed ecology of wetlands and water system,blocked paths in the rainwater cycle and severely interfered natural hydrologic process,which cause such urban problems as frequent waterlogging as well as pollution in water and soil.In view of the problems existing in the management of rain-triggered floods in hilly areas in South China,and through researching domestic and foreign ecological corridor theories as well as sorting and summarizing the practical experience of rainwater management and utilization technologies,this paper proposes that ecological corridors for rainwater which are combined with the rainwater utilization system should be constructed according to the natural geographical conditions in hilly areas.This is an effective method for avoiding floods in hilly areas and promoting the ecological development of hilly cities.First of all,based on the study of the natural characteristics of hilly areas in South China,the characteristics of the rainwater naturalization process in hilly areas and the influencing factors for them are summarized herein,and the basic concept and connotation of rainwater corridor are elaborated as follows:as an important part of ecological corridors on hills,rainwater corridor is a water-naturalization based green belt,which includes the natural rainwater runoff paths on hills and serves as the link among important wetland nodes and a series of ecological patches.Secondly,starting from the rain naturalization process in hilly areas of South China,the rainwater runoff process in hilly areas is simulated by using Grasshopper and Rino software,its characteristics are analyzed,rainwater runoff paths that need to be protected and constructed are identified,and accordingly a preliminary model of rainwater corridor is obtained,which lays a foundation for further rainwater corridor construction.Thirdly,the methods and strategies for the protective construction of rainwater corridors are proposed from the macro aspect,namely the construction of the corridor system,the intermediate aspect,namely the division of corridor levels,and the micro aspect,namely the construction of corridor components.Finally,from the perspective of both spatial planning and project planning in urban planning,a urban planning strategy which is in harmony with the rainwater corridor construction is presented,so as to fully harmonize urban construction with rainwater corridor protection,and to achieve the goal of building ecological cities urban with sustainable development.Finally,the above presented research ideas and results are applied to the practical case of the planning of the new town in southern Wanzai County,Jiangxi province,so as to further examine and deepen the theoretical framework,and verify the application value and practical significance of the research results.Furthermore,in this paper,the parametric technology dominated by Rino software and Grasshopper programming is applied to the simulation of rainwater runoff in hilly areas,in order to advance the application of parametric analysis in hydrological simulation.