Ecological Risk Assessment Of Collapse And Landslide Hazard In Manas River Basin Based On GIS

The Manas River basin is located in the central part of Xinjiang,in the middle section of the northern foothills of the Tianshan Mountains.The ecological environment in the region is fragile,and frequent landslides and landslides have increased the pace of ecological degradation,causing major impacts on the production and life of local people.Ecological risk assessment of collapse and landslide disasters can be used to quantitatively assess the ecological impact of collapse and landslide disasters.This paper takes the Manas River basin as the research area,and builds an ecological risk assessment system for collapse and landslide disasters in the Manas River basin based on the three-dimensional framework of ecological risk assessment of "danger ecological vulnerability potential ecological loss".It is hoped that the study will serve as a reference for local governments to prevent ecological risks and protect the ecological environment.In this paper,nine influencing factors,such as topographic relief,elevation,slope,and topographic humidity index,are selected to construct an evaluation index system for the vulnerability to landslides and collapses in the Manassas River watershed.Information content models,information content logistic regression coupled models,and artificial neural network models were used to assess the vulnerability to landslides and collapses in the Manas River basin.The ROC curve is used to compare the accuracy of the evaluation results of the three models.The ROC comparison results show that the information quantity logistic regression coupled model has the highest accuracy of the susceptibility evaluation results:.Then,three evaluation factors,namely precipitation,human activity,and historical disaster activity intensity,are selected for temporal probability evaluation.The evaluation results are combined with the evaluation results of the information volume logistic regression model to obtain the risk assessment results for landslides and collapses.The results show that the extremely high-risk and high-risk areas are mainly located in the meander zone between low and hilly areas and in the valley zone between middle and high mountain areas.The ecosystem types in the Manas River basin are classified into six types based on the national first-class classification criteria for land use: unused land,urban and rural industrial and mining land,residential land,water area,grassland,arable land and forest land.The ecological vulnerability of the Manassas River watershed was assessed based on the landscape pattern index method in landscape ecology.The results show that the ecosystem vulnerability of unused land is 0.260,the ecosystem vulnerability of urban and rural industrial and mining residential land is 0.811,the ecosystem vulnerability of water area is 0.438,the ecosystem vulnerability of grassland is 0.420,the ecosystem vulnerability of cultivated land is 0.225,and the ecosystem vulnerability of forest land is 0.969,which means that the ecosystem vulnerability of cultivated land is the lowest,and the ecosystem vulnerability of forest land,urban and rural industrial and mining residential land is higher,The areas with high ecological vulnerability in the study area are mainly distributed at the junction of low mountains and hills.The net primary productivity of vegetation,soil conservation,biodiversity,climate regulation,water resources supply and food production among ecosystem service functions were selected to construct an index system for evaluating potential ecological loss in the Manas River basin.The potential ecological loss evaluation results of Manas River Basin were obtained by normalizing the raster graphs of each index and adding them with equal weights by Arc GIS.The results showed that the area with high potential ecological loss was concentrated in the junction of low mountains and hills,and was densely distributed in the alluvial-diluvial plain.The net primary productivity of vegetation,soil conservation,biodiversity,climate Based on the three-dimensional framework for ecological risk assessment of landslides and collapses based on "danger——vulnerability——potential loss",the grid layers of hazards,ecological vulnerabilities,and potential ecological losses of landslides and collapses are multiplied by equal weights through the Arc GIS platform to obtain the ecological risk assessment results of landslides and collapses in the Manas River Basin.The results show that the ecological risk areas of extremely high collapse and landslide hazard are concentrated in the transition region from mountainous to hilly areas,and the risk structure of the extremely high ecological risk areas is mainly high-risk,highvulnerability and high-loss risk structures.