The Research On Multi-scale Urban Flood Control And Storm Drainage Based On Economical Security Of River Basin

During rapid urbanization,the balance between humankind and nature,especially in the mountainous watershed,where the land-use conditions are broken and the ecological environment is fragile.Hence,its terrain,landform,runoff producing and convergence of rivers,and the water quality of river basins undergo significant changes,thus leading to the frequent occurrence of flood disasters in the cities along the river basins.The losses are heavy.Currently,towards the flood disasters in the cities of mountainous watershed,the flood control system engineering is set store by,but little emphasis is laid on the macro factors in the entire water basin during the formation of flood disasters.Due to the lack of systematic flood control and relief regulation method,the research on the nature,features and inherent laws of urban flood disasters is not deep enough.In the paper,the author starts from the overall angle of the comprehensive flood disaster in the river basin and integrates the ecological security pattern theory,urban hydrology and BP neural network analysis method,to analyze the intervention of land hardening and artificial water courses on the landscape structure and morphological characteristics of the water basin,thus resulting in the complex landscape ecological mechanism,water system morphological characteristics,landscape terrain and spatial structure leading to the occurrence of urban flood disasters.On this basis,the author puts forward the quantized regulation and management mode for the flood control in the river basin,that is,to realize rational development and utilization by scientific regulation and management,to reduce disasters and create multi-functional river basin system integrating flood control,ecological aesthetics and landscape aesthetics.In the paper,the analysis is conducted towards the specific flood control and storm drainage planning cases in the macro,medium and micro scales in Jialing River Basin,each river within the river basin and urban area are abstracted into one sub-system(small river basin)in the entire river basin system in the periphery.These small river basins interlinks with other peripheral river basins within Jialing River Basin,thus forming an entire river basin system.By the analysis on the changes in the overall water-cycling system in Jialing River Basin and the occurrence mechanism in urban flood disasters,to discuss the three-level flood control and storm drainage strategy to protect the stability of the ecological system in the river basin,maintain water natural cycling in the city and utilize the rainstorm to make the landscape design on site,thus presenting corresponding planning and construction measures to improve the flood control and storm drainage capacity in the cities within Jialing River Basin.The research contents are mainly shown as follows,Chapter One is about the question presentation and literature review.Firstly,presented with the frequent and easy happening of flood and rainstorm disasters in China,the research background and origin of the paper are narrated,thus leading to the research object and its features,research objectives,and research significance.In addition,towards the traditional rainwater disposal ways as well as the outstanding problems in water resource,water-cycling system and ecological environment and so on during the urban development in China,some typical rainstorm and flood management idea and relevant systems under continuous improvement and development in developed countries in the recent years are briefly arranged.In addition,the features of these systems are compared in the aspects of research scale,control objectives,core connotations and technological measures and so on.Besides,the new rainwater and flood management idea,management experience and scientific research result formed during the urban development in China and developed countries are summarized,on the basis of which,the research contents and framework of the paper are determined and the corresponding research methods and technological routes are formulated.Chapter Two is about the concept establishment and method system.The understanding towards the flood control and storm drainage in urban areas of mountainous river basin is narrated.In addition,the key contents of the work are determined,and the diversified connotations of the three concepts,i.e.,mountainous cities,ecological pattern and river basin,are explained in a more profound manner.Besides,the research methodological system on urban flood control and storm drainage based on the ecological security pattern in mountainous river basin is presented,and the three scales,i.e.,river basin in the macro scale,city in the medium scale and the site in the micro scale,to research urban flood control and storm drainage is demarcated.Combined with the the relevant theories and methods of hydrology regarding convergence analysis in the river basin and convergence unit analysis in urban areas based on GIS,it has been presented that the large-scale river basin ecological security pattern construction shall be taken as the systematic guidance,the medium-scale urban water system optimization and ecological restoration shall be taken as the control guidance,and the small-scale site ecological construction shall be taken as the practical route,to establish the complete urban flood control and storm drainage planning system based on ecological security idea in mountainous river basin.Chapter Three is about the mechanism research and investigation & survey analysis.Based on the statistical research on the historical flood disasters and recent flood disasters in Jialing River Basin,the basic conditions of the urban flood disasters in Jialing River Basin are researched.Besides,combined with the relevant theories of disaster science,meteorology and hydrology,the causes and features of urban flood disasters in Jialing River Basin are analyzed in the perspectives of rainstorm and hydrological characteristics,disaster-inducing factors and hazard inducing environment and so on in Jialing River Basin.Finally,combined with the site investigation & survey and statistical data analysis in Jialing River Basin,the problems in ecological security pattern,urban internal water system and site rainstorm system design are analyzed respectively;besides,the shortcomings in the current water control engineering measures and ideas are analyzed.Chapter Four is about the strategic research and planning intervention.Based on the ecological security idea in the river basin,the urban flood control and storm drainage strategy in Jialing River Basin are researched on the three levels,i.e.,river basin in the macro scale,city in the medium scale and the site in the micro scale.In addition,the three-level flood control and storm drainage strategy of rainstorm micro-cycling design to protect the stability of ecological system in macro-scale river basin,maintain urban water natural cycling in medium-scale city and utilize micro-scale site is presented,which can effective prevent and solve urban flood disasters and multi-scale flood control and storm drainage specific planning measures are presented on this basis.Chapter Five is about the empirical study.The three scales,i.e.,river basin in the macro scale,city in the medium scale and the site in the micro scale,are selected.Combined with the terrain and landform features,hydrological and climate characteristics and regional urban construction features in Jialing River Basin,it has been specifically analyzed how to optimize the ecological security pattern in the entire river basin from multiple scales,thus formulating the flood control and storm drainage planning and management measures suitable to the local conditions,so as to finally prevent and relieve urban flood disasters.Chapter Six is about the research conclusion and prospect.The research result of the entire paper is summarized,the research conclusion and innovative points are summarized,and the research prospect are explored by combining with the latest technological results.