| Landslide is a serious geological hazard which distributed widely with high frequency and strong destructiveness.There are many landslides in our country,which cause great losses to people’s lives and property every year.Landslide susceptibility assessment is a method to predict and estimate the spatial distribution and the possibility of landslide hazards,the results can provide a target area for fieldwork and a basis for landslide risk management,land use planning and disaster warning.Landslide susceptibility assessment based on GIS and RS is a hot topic in the research of disaster prevention and mitigation.In recent years,PSInSAR has also been introduced into landslide susceptibility assessment.Landslide susceptibility assessment combining with PSI can provide a large number of landslide sample data and find slow moving landslides.However,there are still exist the following deficiencies:(1)some research only according the deformation to dividing the prone area,ignoring the basic factors and the result are easily affected by the error of PSI deformation;(2)deformation is not included in landslide susceptibility assessment as a factor,only refining the result by the deformation after susceptibility assessment,and the selection of the deformation threshold and the classification of the prone area are subjective.In view of the above problems existing in the landslide susceptibility assessment combining with PSI,this paper takes the G318 Lhasa section as the study area,combining the PSI deformation data with the conventional landslide susceptibility assessment,selecting the PS point of high variable as the sample and verification point,taking the deformation as one of the influence factors and combining with other factors to establish the susceptibility model,verifying and analyzing the results.In order to further prove the validity of the method and the reliability of the results,the assessment without PSI deformation is carried out.Through comparison and analysis,it is shown that the landslide susceptibility assessment combining with PSI deformation is more consistent with the actual landslide distribution in the study area.It further proves the validity and reliability of the method proposed in this study.The specific research work mainly includes the following contents:(1)Aiming at the problem of dividing landslide prone areas and refining the results based on PSI deformation only,proposing the method that taking PSI deformation as one of the factors,and combining with other factors incorporated into the landslide susceptibility assessment together.(2)Extracting the digital elevation model with the spatial resolution of 10 m in the G318 Lhasa section from the 7 resources ZY-3 images.Based on the DEM data,extracting the slope,aspect,curvature and relative elevation difference factor of landslide susceptibility assessment index system(3)Extracting the deformation of the study area in the period from October 2014 to February 2017 from the 13 sentinel-1 satellite data by PSInSAR,taking the PSI deformation as one of the factors,combining with other influence factors incorporated into the landslide susceptibility assessment together.In addition,selecting the 2421 and 1616 PS points of high variable as the sample points and verification points.(4)Using the 2421 sample points to quantify the influence factors,and assessing the landslide susceptibility of study area by Analytic Hierarchy Process.Finally,the study area is divided into five categories: extremely low sensitive region,low sensitive region,medium sensitive region,high sensitive region and extremely high sensitive region.(5)Carrying out the landslide susceptibility assessment without deformation.Through comparing the two results of combining and without PSI deformation,it is shown that the landslide susceptibility assessment combining with PSI deformation is more consistent with the actual landslide distribution in the study area.It further proves the validity and reliability of the method proposed in this study. |
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