Evaluation Of Eco-environmental Sensitivity In Shiyang River Basin

The ecological environment refers to the synthesis of environmental factors that affect the growth,development,reproduction,be havior,and distribution of organisms as the main body;the integration of natural factors that affect the existence and development of human beings as the main body of human beings.Eco-environmental problems refer to the various negative feedback effects that humans have on their own survival and development,and that in the course of using and transforming nature,they endanger the survival of human beings caused by the destruction and pollution of the natural environment.Eco-environmental assessment is the method of comprehensive evaluation,and refers to the relevant evaluation criteria to assess and predict the quality of the eco-environment in a region.The ecological environment has now become the basis for the survival and development of humankind,and it has also become a necessary condition for social and economic development.Research on the ecological environment is one of the most popular researches today.In this study,Shiyang River Basin,a typical inland river basin in northwestern China,was selected as the research object,and the evaluation indicators were selected based on topography,climate characteristics,and population distribution of the Shiyang River Basin.The selected evaluation indicators were soil erosion,land desertification and land salinization.Then select the criteria for evaluating indicators from the selection criteria of the evaluation indicators,i ce,soil erosion,selected precipitation,soil texture,topographic gradient,surface coverage;Land desertification selection Humidity index,soil texture,vegetation coverage;Land salinization Select evaporation/precipitation,surface coverage,terrain slope.Basing on the Landsat image downloaded on the USGS,combine statistical data,measured data,text data,statistical yearbook data,etc.After GIS technology processing data,obtain the required evaluation index factor ecological environmental sensitivity level distribution map.Using the weighted overlay,the three evaluation index factors were comprehensively evaluated using the spatial analysis module in Arc GIS according to their respective weight distribution maps of the Shiyang River Basin ecological environment sensitivity level.Research indicates:(1)With the support of GIS technology,the study of the ecological environmental sensitivity of a river basin has the operability of the process and the accuracy of the conclusions.established and studied a sensitivity assessment system for the eco-environment in the Shiyang River Basin in order to evaluation and analysis(2)Single factor ecological sensitivity assessment.Sensitivity of soil erosion and land desertification sensitivity are highly sensitive and moderately sensitive.Land salinization sensitivity is highly sensitive and extremely sensitive.(3)Comprehensive assessment of ecological sensitivity.The sensitivity of the eco-environment in Shiyang River Basin is divided into five categories: extremely sensitive,highly sensitive,moderately sensitive,slightly sensitive,and insensitive.The sensitivity of the ecological environment is highly sensitive and extremely sensitive,and the severe ecology of the Shiyang River Basin has been achieved.The environment is very urgent for the management and protection of the ecological environment in the Shiyang River Basin.(4)According to the conclusions reached in this paper,93.0% of the Shiyang River Basin has been sensitive to varying degrees of sensitivity.Sensitivity levels in the southern Qilian Mountains have reached extreme sensitivity,and the sensitive level in the central plains has dropped first and then increased,that is,from extreme sensitivity to height.Sensitive to the human settlements in the central plains,it has become extremely sensitive.The northern hills and desert areas are mainly highly sensitive and moderately sensitive,and appear insensitive in parts of the southeast.