Analysis Of Flooding Mechanism And Resilience Enhancement Strategy Of Urban Waterfront Space

In recent years,there has been a growing trend of extreme urban floods occurring one after another,often breaking through urban flood protection projects and flooding waterfront areas.The established urban flood protection system cannot completely avoid the invasion of cities by extreme floods,causing great hazards to urban waterfront areas and affecting tens of thousands of lives everywhere every year.Previous research usually stand on flood perspective,flood simulation,prediction and early warning,etc.Few studies have examined how to improve the spatial resilience of urban waterfront from the spatial perspective of urban construction to cope with the impact of flood disasters.In this paper,we conduct a study on the mechanism of flood adaptation and flood resilience enhancement strategy of urban waterfront space from the perspective of spatial disaster adaptation.First of all,by combing the development of resilient city theory,urban storm water prevention and management,and urban waterfront space flood prevention and management at home and abroad,we propose the entry point of this paper based on the shortcomings of existing research results,i.e.,to explore the strategy of urban waterfront space flood prevention and resilience enhancement from the perspective of urban built-up space;then,we clarify the three core research objectives of this paper: to explore the influencing factors of urban waterfront space flooding,to clarify the The paper then clarifies three core research objectives: to investigate the factors influencing urban waterfront space flooding,to elucidate the flooding mechanism of waterfront space,to construct the theory and method of waterfront space optimization,to enhance the scientificity and rationality of urban flooding prevention and control measures,and to provide scientific guidelines for urban waterfront space planning and control.Further,the research direction of this paper is clarified: starting from the urban waterfront space,we construct the urban waterfront space flood risk assessment system,make the first judgment of the urban waterfront space flood risk distribution characteristics,and explore the urban waterfront space flood suitability mechanism with the help of two-dimensional hydrodynamic model,so as to provide scientific guidance for the improvement of urban waterfront space flood prevention and resilience.Secondly,the paper analyzes the natural environment endowment of the central city of Chongqing through three aspects: natural geographic environment,socio-economic environment and hydrological resource environment,and cognizes the natural environment profile from the overall level;then the paper analyzes the differences of rainfall and flood control between mountain cities and plain cities,which are reflected in four aspects:differences in land dissipation,differences in path guidance,differences in storage nodes and differences in distribution of disaster points,and proposes the characteristics of waterfront space in mountain cities.Further,on the basis of the research framework,this paper conducts an all-round in-depth research on the waterfront space in the central city of Chongqing from four aspects:architectural design,road traffic,green landscape and water embankment,and points out the current problems in the above four aspects;in the process of construction design research and analysis,the architectural groups of the waterfront space in the central city of Chongqing are summarized in terms of plane type and height difference treatment.Based on the current problems,we reflect on the lack of depth of thinking about planning and construction,the lack of depth of thinking about the recycling of water bodies,and the lack of thinking about reducing the impact of rainfall and flooding from the built-up space itself,which lay down the idea of thinking about the resilience of urban waterfront space from the perspective of built-up space to improve the risk of rainfall and flooding.Third,based on the review of natural disaster risk theories,it was determined that the three elements of risk theory was used as the basis for constructing the flood risk evaluation system in this paper;then,by sorting out the indicators and their frequency of occurrence in the flood risk evaluation system in existing studies,the screening and initial determination of evaluation indicators were carried out;further,combining the connotations of the causative factors(hazard),vulnerability,and exposure in the three elements of risk theory,and the The final indicators for the construction of the flood risk evaluation system were determined by combining the connotation of disaster-causing factors(hazard,vulnerability,and exposure)in the three elements of risk theory and the actual situation of the waterfront space in the central urban area of Chongqing,and then the weights of the indicators in the evaluation body were determined by using hierarchical analysis.Furthermore,the waterfront space in the central city of Chongqing is used as an empirical case to analyze and evaluate the flood risk distribution when it is hit by a 100-year flood,and visualize it with the help of GIS.Finally,under the guidance of the idea of spatial disaster adaptation,the typical spatial pattern distribution and flood hazard risk distribution are integrated and overlaid,thus linking space and flood hazard risk,and the flood hazard risk characteristics of urban waterfront space are initially judged.Fourth,under the guidance of quantitative research ideas,a two-dimensional hydrodynamic model is constructed to analyze in depth the flooding suitability mechanism of five typical spatial patterns,namely,the solitary plan form,the mixed plan form,the row plan form,the perimeter plan form and the free plan form,under different height difference treatments on slopes and terraces from four aspects: flow velocity distribution,water depth distribution,flow field distribution and human and vehicle instability,and to corroborate It also confirms the flood risk characteristics of urban waterfront space and lays the theoretical foundation for improving the flood resilience of urban waterfront space from the spatial level.Fifth,on the basis of the disaster-adapted mechanism of urban waterfront space,and under the guidance of the idea of disaster-resilient city,we propose a strategy to improve the disaster-adapted resilience of urban waterfront space from two aspects: the built-up area and the unbuilt-up area in the central city,combining field research.For the built-up area,it is divided into higher risk area,medium risk area and lower risk area according to the results of flood risk assessment,and the improvement strategies are proposed based on the principles of comprehensive improvement,shortcomings and aesthetics and practicality by combining two examples respectively.For the unbuilt areas,the corresponding enhancement strategies are given from before,during and after the construction according to the disaster-adapted mechanism of urban waterfront space explored in this paper.It is an exploratory study in the context of resilient city construction in China to consider the improvement of flood resilience of urban waterfront space based on built-up space.In terms of research methodology,this paper proposes an analysis framework of flood resilience mechanism of urban waterfront space from the perspective of built-up space,linking built-up space,flood risk and resilience mechanism,and constructing a research paradigm of spatial resilience;in terms of research content,this paper constructs a comprehensive model of flood risk evaluation for research objects with small research scale and difficult data acquisition,and constructs a two-dimensional hydrodynamic model.In terms of research results,this paper proposes a practical strategy for flood resilience enhancement based on the current situation of waterfront space and flood resilience mechanism of urban waterfront space in the central city of Chongqing,which is a positive attempt for subsequent research in related fields.