Spatial Zoning And Application Of Geological Hazards In Mountainous Areas Based On GIS

Compared with other regions,mountainous areas have more complicated geological environment and severe fragile geological conditions.In the process of economic development in mountainous areas,some human engineering activities such as road engineering construction that interacts with the local geological environment will be involved,thus leading to the occurrence of mountain geological environmental problems.More frequent human activities cause greater pressure on the mountain geological environment,frequent mountain geological disasters,and significant threats to road safety.Therefore,the zoning and application research on geological hazards based on GIS in a mountainous case will be conductive to the improvement of the level of geological hazard prevention and control in this mountainous area to a certain extent.National Highway 318 is famous for the most difficult road conditions and the most terrible traffic in the country.Tianquan County,Ya'an City,Sichuan Province is crossed by National Highway 318,and its geographical location is located in western Sichuan and the terrain is mountainous.Therefore,this article chooses Tianquan,Ya'an City,Sichuan Province as an example.The county is used as a case in mountainous areas to carry out research on the risk of geological disasters in mountainous areas.The data required for the research are obtained through field survey data,elevation digital model data,remote sensing image data,various statistical data and related data first on the basis of Arc GIS,ENVI,etc.The technology platform establishes a spatial and attribute database,so as to provide data support for subsequent analysis and research.Then,according to the survey of Tianquan County,there are several types of geological hazards,including unstable slopes,landslides,collapses,and mudslides.It has established a regional geological disaster risk zoning index system from four aspects,namely topography and geomorphology,meteorology and hydrology,geological structure,and human engineering.It adopts the combination of subjective and objective combination weighting method and comprehensive analysis method to conduct the entire study.The level of geological hazard risk is visualized and a workflow model is built to release the GP service,so that related researchers can directly call this model through Web GIS,thus shortening the time for risk identification,and making timely response decisions.Finally,the geological hazard risk zone is divided.The analysis process and results are applied in the monitoring and early warning of highway slope geological disasters:First,the basic situation of the study area was investigated from four aspects: topography and geomorphology,meteorology and hydrology,geological structure,and human engineering.The occurrence mechanism of several major types of geological hazards in the study area and the occurrence mechanism of the study area were analyzed,with temporal and spatial distribution characteristics.Second,based on the basic situation of the study area,the study area's topography and geomorphology,meteorology and hydrology,geological structure,human engineering,etc.are collected,and the spatial data of these four areas are directly or indirectly obtained.Arc GIS spatial analysis methods and ENVI,EXCEL,SPSS and other auxiliary technical means are used to mine and organize spatial data to establish a geological environment spatial and attribute database of Tianquan County,Ya'an City,Sichuan Province.Third,according to the occurrence mechanism of geological disasters in the study area,the surface slope,undulation,cutting depth,topographic humidity index,distance to the river,vegetation coverage index,rainfall,soil type,distance to the fault zone,and earthquake impact area are extracted.A total of 15 index factors such as distance from roads,etc.,established a geological hazard risk zoning index system in the study area with the combination of subjective and objective weighting method to calculate the weight of each index factor,and the comprehensive analysis method combined with Arc GIS is adopted to carry out the geological disaster risk zoning of the entire study area,and the visual zoning result of the geological disaster risk grade in Tianquan County is obtained finally.Fourth,the work process of regional geological disaster risk zoning was made into a workflow model that was released through Arc GIS for Sever GP service.Afterwards,the macro-regional risk zoning was combined with the micro-hazard point monitoring and early warning.Visualized regional disasters and linear road safety are combined together to study the application of regional geological disaster risk zoning analysis in the highway slope geological disaster monitoring and early warning system.The paper proposes a set of geological hazard risk zoning index system that is suitable for mountainous areas.The results of the geological hazard risk level zoning within the study area are analyzed in the spatial area.Meanwhile,it is used as the basis for the judgment of key dangerous slopes,and a set of visualization is established.The zoning system will make the entire zoning process into a workflow model and be published as a GP service,so as to provide work process reference for related researchers,and provide theoretical and technical support for the monitoring and early warning of geological disasters on mountain highway slopes.