Study On The Risk Change Of Earthquake Disaster In Sichuan Yunnan Region Based On Remote Sensing And GIS

Earthquake is one of the most serious natural disasters that human beings encounter,and its abruptness and harmfulness rank first among other natural disasters.Due to the expansion of urban scale and the improvement of modernization level,the exposure of human society to earthquake disasters is increasing rapidly,and the earthquake risk faced by human society is gradually increasing.Therefore,timely and effective assessment of earthquake disaster risk changes caused by urban change is of great significance for the continuous development of urbanization and earthquake prevention and disaster reduction in China.The risk of earthquake disaster is mainly determined by the interaction of hazard,exposure and vulnerability.At present,the research on earthquake disaster risk mainly focuses on the disaster causing factors and the vulnerability of the disaster bearing body,but the research on the exposure of the disaster bearing body is not enough.However,with the rapid expansion of China's cities,the rapid increase of urban population and socio-economic activities has led to the rapid growth of disaster bearing body exposure.Therefore,the quantitative assessment of disaster bearing body exposure is a very important research direction which needs to be further explored.Taking Sichuan Yunnan region as an example,this paper obtains the ten-year scale urban land use change in Sichuan Yunnan region from 2000 to 2020 by using globeland30 land cover data,and introduces the landscape ecological index analysis method to analyze the characteristics of urban spatial distribution change in Sichuan Yunnan region from the changes of urban patch area and quantity,and then quantitatively evaluate the exposure of disaster bearing bodies in the study area Sexual change.At the same time,based on the socio-economic statistical data and social vulnerability index method,this paper analyzes the changes of social vulnerability in Sichuan Province from 2000 to 2020,and analyzes its correlation with the changes of earthquake risk.The main contents of this paper are as follows:(1)using remote sensing(RS)and geographic information system(GIS)methods to analyze the change pattern of urban spatial distribution in Sichuan Yunnan region,and quantitatively evaluate the exposure change of urban disaster bearing bodies in Sichuan Yunnan region.(2)Based on the exposure change of urban disaster bearing bodies,the change of earthquake risk in Sichuan Yunnan region from 2000 to 2020 is analyzed,and the correlation between the geomorphic characteristics that may lead to the change of urban spatial distribution and earthquake risk is analyzed.The experimental results show that there is a positive correlation between earthquake risk change rate and urban discrete change.Compared with other terrains,mountainous areas have a greater impact on the seismic risk change index.For districts and counties with the same topographic conditions,the seismic risk change index is mainly affected by the change of urban spatial distribution.(3)Based on the method of social vulnerability index,a comprehensive vulnerability analysis of Sichuan Province is carried out.The social vulnerability index of each county in Sichuan Province from 2000 to 2020 is constructed by using the socio-economic statistical data,and the correlation between the change characteristics of urban spatial distribution and the changes of social vulnerability and earthquake risk is analyzed.The results of experiment show that there is a positive correlation between the change rate of earthquake risk and the change of social vulnerability.At the same time,the agglomeration development of cities has a great impact on the changes of social vulnerability and earthquake risk.The above research results prove the effectiveness and practicability of the analysis method based on remote sensing and GIS in the analysis of large-scale earthquake risk change.