Research On Urban Waterlogging Emergency Management Platform Based On PPRR Theory

In recent years,global warming has affected the local climate characteristics of cities.The rapid development of urbanization has increased the impervious area.The impervious area has hindered the infiltration process of heavy rainfall.Under the joint action of different factors,urban waterlogging appears frequently in different cities,causing serious economic losses and human casualties,and endangering the healthy and orderly development of economy and society.In view of the research status of urban waterlogging emergency management,this paper takes into account that the process of urban waterlogging emergency management is composed of many factors.Based on the micro-perspective of system dynamics,the system dynamics model of urban waterlogging emergency management was established to analyze the causal feedback relationship among variables at different levels.The case-based reasoning method was used to calculate and select similar cases.Based on the PPRR theoretical framework of four stages of prevention,preparation,response and recovery,the urban waterlogging emergency management system was formed,and the urban waterlogging emergency management platform was designed.It provides decision support for urban flood control and disaster reduction.The main research achievements are as follows:(1)The model of urban waterlogging emergency management was established.Based on the theory of system dynamics,the key components of three sub-systems,namely,preparation,handling and post-handling,were selected.Analytic hierarchy process(AHP)and entropy weight method were used to determine the influence weights of emergency response.Based on the weight,the model equation was established to form the causal loop diagram and stock flow diagram.The simulation and sensitivity analysis of the model were carried out.The results showed that the degree of impact on urban waterlogging emergency management was followed by management factors,technical factors,natural factors and social factors.Ten factors,such as maximum rainfall intensity,rescue response time and emergency plan level,were selected as the main variables of CBR through sensitivity analysis.(2)A method of scheme optimization based on CBR was proposed.According to the event characteristics and evolution process,the index system of "pressure-state-response" stage of urban waterlogging event was established.The CBR method was used to calculate the similarity between target cases and historical cases.The results showed that P4 had the highest similarity with the target case in the historical case base.Using this case as the basis for reuse is convenient for relevant departments to quickly formulate response plans.(3)An emergency management platform for urban waterlogging was developed.Based on the whole process emergency management system of prevention,preparation,response and recovery under the framework of PPRR theory,the urban waterlogging emergency management platform was designed and developed.Taking Xi ’an City as an example,the platform was applied to realize the emergency management of the whole process of "prevention,preparation,response and recovery" of waterlogging disaster.Based on the established emergency plans base and case-based reasoning method,the historical source cases were obtained by retrieving and matching the new cases and the similar knowledge elements in the emergency plans of the historical case.The solution of new cases can be obtained by revising and adjusting historical cases through emergency consultation,It quickly starts emergency response and provides decision support for urban waterlogging emergency management in a visual environment.