| Our country has vast land,complex geological conditions,active tectonic movements,and frequent geological disasters have caused huge loss of life and property to the local people,severely restricting regional economic development and people’s happiness.Among many geological disasters,landslide disasters occur most frequently and cause the most losses.The traditional landslide monitoring method is difficult to cover the area where the human power cannot reach.At present,the commonly used remote sensing monitoring technology also has the problem that the spectral information is not fully utilized.Therefore,the advantages of fast acquisition of multispectral remote sensing data,large coverage area,and strong periodicity to monitor the growth trend of landslide bodies are an effective means to understand the evolution process of landslides,improve the remote sensing monitoring system of landslides,and improve the energy efficiency of disaster prevention and mitigation.It has very important scientific and practical significance.The thesis takes the "2018.10.10" Baige landslide as the research object,and on the basis of the existing research results,summarizes the causes and evolution of the landslide.Extract spectral characteristics based on multispectral remote sensing data,use wavelet analysis method and spectral change intensity analysis method to mine information,extract regional deformation history and spatial distribution characteristics of deformation within 20 years of landslide evolution,analyze the spatial and temporal characteristics of deformation movement of Baige landslide,And establish a landslide body monitoring process,build a remote sensing landslide dynamic monitoring system.The main results and conclusions achieved are as follows:(1)Spectral change relative intensity method is proposed to monitor the chronological dynamic change of landslide body length.This method sets up a control group for the monitoring area,and monitors the dynamic change of the landslide body by calculating the relative spectral change intensity between the monitoring area and the control group.(2)The wavelet low-frequency analysis method is proposed to monitor the timeseries dynamic changes of landslide body.This method uses the rich spectral information of remote sensing data,based on the targeted indicators,and uses wavelet analysis to monitor the dynamic changes of the landslide body.(3)Compared with related data,the relative intensity method of spectral change and the wavelet low frequency analysis method can effectively extract the main period and spatial position of the Baige landslide change,and also have a higher time resolution than conventional remote sensing monitoring methods.The wavelet low frequency analysis method has higher stability.(4)Use this technology to monitor the deformation of the Baige landslide area and obtain the history of regional deformation before the occurrence of the landslide.The results show that the Baige landslide has three main changes in the 20 a period from 1998 to 2018,which are 2002-2004,2008-2010 and 2014-2018.In terms of the spatial distribution of the change zone,part of the avalanche zone shows a more clear and severe change history,and shows the stage characteristics and accumulation characteristics of the landslide displacement deformation.Part of the landslide area is similar to the overall deformation trend of the landslide body,with long-term continuous changes.Among them,the "August 12" Changdu M6.1 earthquake in 2013 caused a clear impact on the development of landslides.(5)Based on the Landsat series of remote sensing data,establish a long-term remote sensing monitoring process for the Baige large-scale rock landslide body to provide a reference for the long-term remote sensing monitoring of other types of landslide bodies.(6)According to the advantages and disadvantages of different monitoring methods,based on remote sensing technology,combined with on-site instrument monitoring technology,build a three-inspection monitoring system for "examination,detailed investigation,and verification" of landslide disasters to provide support for the prevention and treatment of landslide disasters. |
