Application And Dynamic Assessment System Of Urban Safety And Security Based On Risk And Emergency Capacity

By the end of 2021,the urbanization rate in China has reached 64.72%,urban development has ushered in unprecedented opportunities and driving forces.However,urban safety and security is also facing new risks and challenges.At the same time,considering the impact of urban risk and emergency capacity on urban safety and security,building a dynamic assessment model of urban safety and security based on them and developing a dynamic assessment system are of great significance to improve the dynamic risk control capacity and emergency capacity of urban area.The main research contents of this paper include:(1)Research on dynamic assessment model of urban safety and security based on risk and emergency capacity.From the perspective of combining risk and emergency capacity,clarify the assessment objects and elements of urban safety and security.Considering the influence of time and space factors,establish the idea of dynamic assessment of urban safety and security,and build the dynamic assessment process and model of urban safety and security based on risk and emergency capacity.Determine the specific assessment indicators and quantitative grading standards for the assessment elements,and put forward a set of grade evaluation criteria for risk,emergency capacity and urban safety and security.The above provide a theoretical research basis for the development of urban safety and security dynamic assessment system.(2)System analysis and design.Analyze the user demand and content demand of urban public security dynamic assessment system.Put forward the principles of system design and select the development technology from the aspects of development architecture,platform,software and technology.Design the system framework in detail from three aspects: logic structure,programming structure and technical support.Design the four functional modules of user management,map management,source data management and visualization management and the whole implementation process of the system.Design the data table framework of the system in a separate-tabular and hierarchical manner to improve the flexibility and response efficiency of data interaction.(3)System development and realization.Preprocess the point,line,surface and grid layers of risk concentration unit and emergency organization place to form local layer resources.Apply Node JS front and background transmission interface,Arc GIS API for Java Script development interface,Echarts visual chart library and other core development technologies to realize user login and registration functions,map basic controls and layer superposition functions,source data acquisition,editing and processing functions,as well as statistical visualization,static visualization,and dynamic visualization of assessment results.These functions realize efficient and accurate data processing for urban safety and security dynamic assessment,and show the results of statistical law,static spatial distribution rendering,dynamic spatio-temporal evolution,and dynamic data update.(4)Case application.Select an urban area in China and determine the evaluation objects for pretreatment of point,line,surface,and grid layers.Apply G1 Method and Entropy Weight Method to determine the weight value of the assessment indicators combining subjective and objective weight.Demonstrate the visualization effect of statistical results,static spatial distribution,dynamic spatio-temporal evolution,and dynamic data update.Then obtain the ownership,spatial distribution,spatio-temporal evolution law of assessment results,and promotion effect of urban safety and security after simulated decision-making.These analyses can help to determine the key periods and regions which need prevention and control emphatically,and assist in fine adjustment of decision-making scheme.The case application results show that the dynamic assessment algorithm is efficient and accurate,and the visualization results are reliable and effective.The system has good operability and expansibility.