Research On Spatial Analysis Methods Of Urban Earthquake Disaster Simulation

The fast developing SIT (Spatial Information Technologies) has provided new tools for the research on urban earthquake disasters in recent years. As a prospect one among these tools, SIA (Spatial Information Analyst) can be integrated into the models of urban earthquake disaster assessment. Such models can be used to simulate the urban earthquake disaster scenario which can provide important information for enhancing anti-seismic capabilities of a city and improving the efficiency of seismic count-emergency.This paper mainly focuses on how to integrate SIA into the urban earthquake disaster simulation. Herein, the spatial analysis methods for urban earthquake disasters are concretely discussed from the angel of spatial information expression, analysis and explanation.In terms of seismic hazard simulations of some wildly spreading urban systems, such as lifeline systems and building groups, the difference of inputting seismic action in spatial distribution should be considered. But how to input earthquake motion parameters discriminatively based on the spatial attenuation of seismic action is still unsolved by now. Therefore, a new model, called seismic action spatial analysis (SASA) model, is proposed to quantitatively determine the inputs of seismic action. In SASA model, the effect and incidence of assumed earthquake is simulated by using spatial analysis techniques and the effect of site conditions is also taken into account. In general SASA model involves two parts: raster analysis for assumed earthquake and raster analysis for site condition. The former is to simulate the even spatial distribution of earthquake motion on the basis of the hypocenter characteristics and the attenuation relations. The latter is to acquire and analyze the spatial information about site conditions for the adjustment of seismic action inputs.Wildly-spread Buildings in the city are the most important objects in urban earthquake disaster simulation. It is customary to use electronic maps, which store related information about urban buildings, as the basic data sources of seismic hazard simulation. but some problems existing in urban building electronic maps, such as the inconvenience of data updating, the deficiency of data precision etc., seriously depress the reliability of simulation results. As a better solution, the latest TM/ETM+ images and the technique of creating spatial raster are firstly introduced into the urban seismic disaster evaluation. Comparing with traditional electronic maps, using RS images as data sources completely overcomes all the problems mentioned above and cuts down the cost especially for large-scale maps. On this condition, this paper describes the way of creating building information raster based on TM images, and discusses the spatial analysis methods for urban buildings earthquake disaster simulation based on raster-type building data. It is effective to get the latest data about spatial distributions of urban buildings by using RS images and convenient to consider all the factors that affect earthquake disasters of building groups.