Research On Dynamic Evolution Characteristics And Modeling For Urban System On Earthquake Resistance And Hazardous Prevention

In recent years,strong earthquake occurs repeatedly at home and abroad. Due to excessive concentration of urban population, high degree of intensive economy, weak infrastructure and poor geological, geographical environment of the urban expansion, a series of factors, the phenomenon that earthquake disaster loss of modern urban is more and more serious.At present, most studies on urban earthquake disaster prevention is based on static index system, there are still many problems in the process of dynamic development for urban system of earthquake resistance and hazardous prevention. urban earthquake resistance and hazardous prevention is a dynamic development process, the research object of urban system of earthquake resistance and hazardous prevention is the urban system which is developing continuously. The associated complexity and dynamic feedback of urban system of earthquake resistance and hazardous prevention determine which must use theories and methods of complex analysis to study.Based on above, considering the characteristics including dynamic evolution, associated complexity, multi-levels in macro and micro fields of urban system of earthquake resistance and hazardous prevention. taking people, things, and environment as starting point, from the dynamic point of view, combining microcosmic and macroscopic, preliminary studies of dynamic evolution model of urban system of earthquake resistance and hazardous prevention has been carried out by applying system dynamics on basis of statistical data and historical research. In this paper, the main studies in the following are:(1) Disaster prevention use for urban construction landConsidering characteristics of disaster prevention,structure dynamic optimization model for urban construction land is established based on system dynamics and multi-objective optimization model. The influence of potential earthquake risk on urban construction land was the research object. The disaster prevention benefit target function was set and optimized, and solved with genetic algorithm in the paper. According the SD-MOP integration model constructed in the paper, taking Wuxi as an example, the urban construction land use structure, industrial construction land scale and complex behavior of system were simulated dynamically.(2) Evaluation on personnel emergency evacuationRoad’s emergency evacuation SD model is established based on system dynamics. the dynamic feedback of earthquake evacuation was analyzed from three aspects that disaster environment, road space, and personnel characteristics,then the road evacuation causal model and flow model based on system dynamics were established. Complied with the standard for urban planning on earthquake resistance and hazardous prevention for emergency shelter, evacuation roads and evacuation time,dynamic simulation on the road evacuation capabilities of crowded emergency evacuation area during the earthquake was conducted, related recommendations was gave for key personnel-intensive area planning from the simulation results.(3) Seismic potential secondary disaster preventionRisk assessment model of urban earthquake potential secondary fire was constructed based on attribute interval recognition theory. the evaluation index system for the urban post-earthquake fire was presented in terms of urban disaster hazard, exposure and vulnerability of disaster bearing body and disaster-carrying capability. Meanwhile, the grading standards of evaluation index were also given. Comprehensive weight method was adopted to determine weight to eliminate all kinds of uncertainty to maximize. Finally, potential risk analysis for a city’s post-earthquake fire was provided to validate and prove its efficiency and feasibility.(4) Buried personnel loss evaluationDynamic assessment model for buried personnel loss of collapsed buildings in urban earthquake was conducted based on system dynamics. Dynamic feedback of system was analyzed from four subsystems that earthquake damage subsystem, casualties subsystem, emergency rescue subsystem and earthquake resistance and hazardous prevention subsystem, then the causal model and flow model based on system dynamics were established. Complied with the standard for urban planning on earthquake resistance and hazardous prevention for emergency shelter, evacuation roads and others, dynamic simulation on the buried casualties and emergency rescue of different earthquake moments after the earthquake was conducted, related recommendations was given for the disaster prevention and emergency rescue of densely populated areas.(5) Emergency suppliesEvaluation model for emergency supply ability of food supplies in city was proposed based on city’s usual material circulation situation. Through the analysis for urban historical statistics, dynamic indices were select to calculate the days that city’s circulation supplies at ordinary times can supply after earthquake for people’s lives. Function distribution was assumed and tested according to the results. On this basis, the reference curves reaching a certain emergency supplies level after earthquake were get, were includes probability curve of government subsidy under a certain security days for an earthquake and probability curve of government subsidy under a security probability for an earthquake.