| The Xiaojinchuan Basin is located in the upper reaches of the Dadu River,and is affected by factors such as special climate and landforms.Both sides of low-altitude rivers have high temperatures and less precipitation,which belongs to the arid valley area.The ground surface in the area is severely broken.Due to the close proximity to Wenchuan County on the east side,after the "5.12" Wenchuan earthquake,geological disasters in the basin increased sharply and the slope was more unstable.Based on the research topic of "Research on Ecological and Geological Environment Evaluation Models of Typical Hydropower Reservoir Areas in the Dadu River Basin",this paper conducts field surveys and remote sensing interpretations of geological disasters in the Xiaojinchuan Basin.Establish a geological disaster susceptibility assessment model,partition the susceptibility of the basin and propose prevention and control measures.The main research contents and results are as follows:(1)Using unmanned aerial vehicles to conduct field investigations and remotely interpret geological hazards by constructing an interpretive identification database,a total of 559 geological hazards were counted in the area,including 134 landslides,65 landslides,and 360 debris flows.It is mainly concentrated on both sides of Wori River,Fubian River and Xiaojin River,and it occurs mostly from May to September with heavy rainfall.(2)By discussing the relationship between geological disasters and geological environmental factors,it is concluded that regional geological disasters are mainly controlled by special formation lithology and geological structure.From the perspective of natural environment and human activities,geological disasters mainly occur in river valley landforms,and the slope is convex,The slope direction is southwest,south,southeast and east,the slope is between 20-45°,the undulation is 20-40 m,the soft rock group is within 200 m from the water system,the soil type is semi-leaching soil,rainfall Less,where the vegetation coverage is within 0.6-0.8 and within 200 m of the road.(3)Taking the slope as the evaluation unit,the slope,aspect,slope shape,undulation,soil type,vegetation coverage,distance to the water system,precipitation and distance to the road are selected as the evaluation factors,and a comprehensive evaluation model is constructed using logistic regression and information method,The susceptibility zoning of the Xiaojinchuan River Basin.The results show that: extremely high-prone areas,high-prone areas,medium-prone areas,low-prone areas and extremely low-prone areas in the watershed account for 14.59%,19.95%,31.73%,21.92% and 11.80%,respectively.The evaluation model passed the receiver operating characteristic curve(ROC)area under the line(AUC)test,the accuracy was 0.827,and the evaluation model had good accuracy.(4)According to the susceptibility zoning of geological disasters and the economic and social development planning in the basin,the geological disaster prevention and control zones are divided.It is proposed that in key prevention and control areas,geological disasters should be treated in a timely manner,centralized limited funds should be scientifically and rationally rectified,and strict geological hazard risk assessment should be carried out for newly built or rebuilt projects.Mainly to avoid concessions,appropriate measures for slope transformation and soil conservation tillage can be configured in the medium and long term to reduce soil erosion and improve the natural ecology and geological environment.The general prevention and control areas are mainly plateaus with sparsely populated populations and strengthen geological disaster monitoring. |
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