Study On The Trafifc Emergency Evacuation Model Of Chengdu Based On The Spatial Diffusion Of Rainstorm-waterlogging

Chengdu is a core growth pole in western China, and the urbanization hasaccelerated noticeably. Under the impact of global climate changes, there is an increase inextreme weather recent years and rainstorm-waterlogging disasters occur frequently, bringinga big loss to people’s lives and property safety. So it is strongly necessary to simulate thedistribution of waterlogging areas and create a traffic emergency evacuation model.This thesis took the main city zone of Chengdu as a case study. After literature, datacollection etc., and based on the full use of the geospatial information technology and thepurpose of evacuating people as soon as possible to reduce disaster losses, the author built thespatial diffusion model of waterlogging and the traffic emergency evacuation model ofChengdu which are suitable for the cities in plain areas. The main contents and achievementsare as follows:1) The author built the spatial diffusion of model waterlogging by stacking the30mDEM and the extreme rainfall data on the assumption that the rainfall in the studydistrict was homogeneous. And this was realized in the model generator platformbased on the hydrological analysis. Its precision was up to85.75, which basically metthe requirements of the submerged simulation of Chengdu rainstorm-waterlogging.Subsequently the author did an analysis of the spatial distribution characteristics ofChengdu rainstorm-waterlogging.2) Under the consideration of the formation of waterlogging and the emergencyevacuation, the author created the traffic emergency evacuation model combiningwith the optimal path method and the most typical Dijkstra algorithm. And the modelwas programmed in the Matlab platform during which the batch processing of all thespatial data and attribute data was realized in Arcpy and Matlab programming platforms. And then the results analysis interface of the traffic evacuation model wasbuilt in which the optimal route was given a highlight color to offer a static visualdisplay of the evacuation routes. Moreover，an analysis of the comparison betweenthe simulation and the practical results was provided. More specifically, Yulin, atypical waterlogging area in Wuhou district in northwestern Chengdu was taken as acase study and the simulation error was allowable.3) The author did a comprehensive analysis of the spatial distribution characteristics andcauses of Chengdu rainstorm-waterlogging, and also proposed preventive measuresand coping strategies once the traffic jams occurred caused by waterlogging.4) The traffic emergency evacuation model in this thesis confirms that the geographicinformation space algorithm has universal value so that traffic mitigation responseoptions can be proposed in other possible waterlogging areas.Three innovation lie in this thesis:1) the author avoided the demanding conditions of thehydrological and meteorological data and focused on the latter emergency evacuation;2)based on GIS spatial analysis capabilities, the simple spatial diffusion model ofrainstorm-waterlogging was built with a proper precision, which was not only closer to reality,but also reduced the computation time-consuming and made a fast emergency simulation;3)spatial diffusion of rainstorm-waterlogging and traffic emergency evacuation model hasa good promotional in nature.