A Preliminarily Study On The Regional Macro Change Of Vulnerability To Seismic Disasters

This thesis is based on the statistical data of economic and social development of the Beijing-Tianjin-Tangshan areas in 1985, 1995, 2000, and 2004. In terms of the methods such as main component analysis and factor analysis, this work discusses the implication of the regional macro vulnerability to seismic disasters and its indexes for description, and analyzes its variations in space and time for the study areas. The conclusions of this thesis are summarized below.1.Implications and description indexes of the regional macro vulnerability to seismic disastersThe vulnerability to seismic disasters is an inherent attribute of an area. It means that when this area is hit by a destructive earthquake, how much the possibility of destruction and losses will be, what the size of potential destruction and loss will be, and the resume ability after the destruction.Through analysis of factors influencing regional macro vulnerability to seismic disasters, an index system based on statistical information of social economic development is proposed. By correlative and consistent correction, an index system to evaluate vulnerability to seismic disasters is yielded. The indexes include those to describe the amount of exposed objects to disasters, sensitivity and elasticity of disaster bearers, and regional capability of relief, restoration, and reconstruction.2.Spatial change of vulnerability to seismic disasters in the study areaThe situation of the year 2000 is used as a case for analysis.1) Influence models of vulnerabilityThrough analysis of main components in the matrix describing vulnerability, six influence modles of vulnerability for 2000 are obtained. The model I is the primary one which influences the variations of the regional macro vulnerability to seismic disasters in the study areas. In this model, the change of positively correlative variables is in accord with the change direction of the macro vulnerability in the areas, while that of negatively correlative variables is opposite with the change direction of the macro vulnerability in the areas. This is roughly consistent with the qualitative conclusion that the vulnerability increases with growing GDP and declines with increasing financial income of every county in the study areas.Regional differences of vulnerabilityBased on analysis of the matrix describing vulnerability for 2000, the macro vulnerability to seismic disasters of every district and county in the study areas are evaluated. In this year the areas which are extremely vulnerable and very vulnerable to earthquakes are located in Beijing city, Tianjin city, Tangshan city, and Qinghuangdao city. The areas of fair vulnerability are distributed continuously in the middle and southwest portions of the study areas. The middle of the study areas, from Langfang, Pinggu county, and Jixian county to the three counties of western Tangshang, as well as the southwestern part except Wenan county, belong to the very vulnerable level. Such a...