Method And Model Research Of Quantitative Seismic Intensity Evaluation Based On Remote Sensing

Seismic intensity is one of the most common ways of expressing the damage in an earthquake area.The traditional method of on-site investigation and evaluation of intensity can not meet the requirements of emergency rescue.In recent years,with the development of remote sensing technology,it is possible to obtain high resolution remote sensing images with fast aging and wide coverage.After many years of research by experts and scholars,the method of extracting earthquake damage by remote sensing and realizing rapid evaluation of earthquake intensity by establishing the transformation model of remote sensing earthquake damage index has been formed and tested by many earthquake cases.However,in view of the different data sources and sensor resolutions of images obtained by different earthquakes,and the differences in building characteristics and seismic capacity in different countries and regions,non-local models cannot accurately reflect the disaster situation,and it is necessary to establish a model that conforms to the local area.In addition,in recent years,with the improvement of earthquake monitoring and early warning network,station recorded parameters are gradually included into the seismic intensity assessment.At present,there are few studies on the complementarity and combination of station data and remote sensing data in seismic intensity assessment.Aiming at the regional limitation of remote sensing quantitative transformation model of earthquake damage and the limitation of evaluating earthquake intensity with a single index,this paper mainly carried out the following researches,and obtained the corresponding results as follows:1.Establishment of remote sensing single index intensity evaluation modelBased on the remote sensing interpretation of building earthquake damage,the conversion relationship between remote sensing damage index and actual earthquake damage index is constructed on the basis of the field earthquake damage survey data and Gaofen satellite remote sensing images in Nepal in 2015,and the earthquake damage index and earthquake intensity of all interpretation points are estimated.The results show that the estimated intensity is in good agreement with the field survey results,and the model can be used as a reference for emergency remote sensing and intensity assessment in future destructive earthquakes in Nepal and other South Asian countries and regions.2.Exploratory research on multi-index comprehensive intensity evaluation methodBased on the remote sensing interpretation of earthquake damage and the records of earthquake monitoring and early warning network,the probability density function of remote sensing earthquake damage index,peak acceleration and peak velocity under different intensity is established based on the remote sensing images and ground motion data obtained after the 2022 Lding M6.8 earthquake in Sichuan Province,and the seismic intensity weighted assessment is completed for 10 typical residential areas.The results show that 90% of the error between the estimated intensity and the published intensity is within 1 degree.This method can be used when the quality of remote sensing image data is poor after the earthquake.3.Research on uncertainty evaluation methodsThe constructed models generally have uncertainty.In this paper,the established remote sensing quantitative transformation model of Nepal earthquake damage was evaluated and analyzed by using the "crossvalidation" method,and the method of constructing multiple models and adding error of calculation results was used.The results showed that the intensity calculation results of each model could be controlled within 1 degree,and the uncertainty of the model was small.The model is stable and reliable in general.