Ecological Vulnerability Assessment Based On Soil And Water Conservation Functional Zoning

As a typical representative of ecologically fragile areas,the southwestern karst area has prominent contradictions between human and land,and the harsh natural environment restricts the local social and economic development.With the continuous advancement of social and economic development,people's social activities have also had a greater impact on ecological vulnerability.Based on the research on the ecological vulnerability assessment of the study area based on the functional division of soil and water conservation,this paper selects Zunyi City of Guizhou Province as the research object,and uses the software platforms to use remote sensing surveysuch as ARCGIS10.2 and ENVI5.1,statistical analysis of digital drama and spatial superposition analysis.The method is to evaluate the ecological vulnerability of the study area and combine the soil and water conservation function zoning to discuss the different fragility areas and put forward the policy recommendations for comprehensive prevention and control of soil erosion.This paper combines the functional division of soil and water conservation with the evaluation of regional ecological vulnerability,which is conducive to the scientific and comprehensive prevention and control of regional soil erosion.The two participate in the government management,specify the comprehensive prevention and control measures of soil erosion,and clarify the key points of comprehensive prevention and control of soil erosion,and play an important role in ecological security construction.This study selects water source conservation location,urbanization rate,agricultural production direction,total water resources,biological abundance,multi-year average temperature,and multi-year average from four aspects: soil and water conservation functional elements,natural factors,socio-economic factors,and soil erosion factors.Precipitation,average elevation,soil type,slope,vegetation coverage,area ratio of soil and water loss,area ratio of sloping farmland,population density,per capital GDP,natural population growth rate,16 evaluation index factors,and construction of Zunyi City ecological vulnerability evaluation index system Conduct ecological vulnerability assessment in Zunyi City,and use AHP to determine the weight of each subsystem and each evaluation index.Finally,based on the scores and weights of each indicator,the research area ecological vulnerability assessment model EVI(Ecological Environment Vulnerability Index)was established to evaluate the ecological vulnerability of Zunyi City.The main conclusions are as follows:(1)In the ecological vulnerability assessment system of the study area,the weights of the four subsystems from top to bottom are soil and water loss factors(0.3359)> soil and water conservation function factors(0.3126)> natural factors(0.1997)> socioeconomic system(0.1518).(2)The value of the ecological vulnerability index in Zunyi is between 0.236535-0.804503 with an average of 0.686255.According to the grading standards,the ecological vulnerability of the study area is divided into five levels.EVI below 0.40 is a potential vulnerable zone,EVI value is slightly fragile between 0.40-0.56,EVI value is moderately fragile between 0.56-0.65,and EVI value is higher than 0.65 is severely vulnerable.It is calculated that in the ecological environment of Zunyi City,the moderately vulnerable area is the largest,which is 11448.92km2,accounting for 37.19% of the total area of Zunyi;the area of severely vulnerable and slightly vulnerable areas is 10441.33km2 and 6815.83km2 respectively.It accounts for 33.91% and 22.14% of the total area;the area of potentially vulnerable area is 2080.79km2,accounting for 6.76% of the total area.(3)In terms of ecological fragility of the soil and water conservation functional area in the study area,the southern low mountain and middle mountain lightly drained the human habitat environment water conservation area,followed by the ecological fragility index from high to low,the water quality maintenance and ecology in the central and western regions.Maintenance area,soil conservation area in the northeast,soil retention area in the east,soil conservation and ecological maintenance area in the southeast,the ecological vulnerability index is: 0.635219,0.614056,0.575226,0.489576,and the functional area with the lowest ecological vulnerability is the ecological maintenance of the northwest.District,the region's vulnerability index is 0.346762.