Ecological Environment Quality Assessment In Qinling Mountains Of Shaanxi Based On Fuzzy Evaluation Method

Qinling Mountains are an important ecological security barrier in China,which are geographic and climate line between the southern and northern China,and have a high value to protection.However,environmental problems such as soil erosion are also serious.To solve the environmental problems and coordinate relationships between humans and land,ecological environment quality assessment system of the Qinling Mountains in Shaanxi was established based on remote sensing,climate,soil and other data.The grid as the evaluation unit was used to construct the ecological environment quality evaluation index.The Analytic Hierarchy Process(AHP)and the Coefficient of Variation(CPA)were considered to calculate the weight of each evaluation index.The fuzzy evaluation method was necessarily used to evaluate ecological environment quality,including years of 2000,2010,and 2018.The spatial environment quality changes from the whole the region,different counties,and different slope directions were objectively described.Finally,the impact of the population density and economic density on ecological environment quality was discussed.The results we get are following:(1)The ecological environment quality in the study area was at a good level,and it was getting worse from the middle to sides.The areas with good quality,general quality,poor and extremely poor quality were 61.10%,29.87%,8.93%,and 0.10%,separately.Good quality areas mainly located in the middle of the study area where the altitude and woodland coverage were higher;general areas mainly distributed around the good areas,with slightly lower elevation and poor ecological environment;while the poor and extremely poor areas had low vegetation coverage and were heavily influenced by humans.(2)From 2000 to 2018,the ecological environment quality of the study area developed well,good quality areas expanded,and the rate from 2000 to 2010 was significantly higher.In addition,the poor quality and extremely poor areas accounted for 13.30%,7.30%,and 6.50%in the years of 2000,2010,2018,respectively,showing a law of decreasing.(3)The overall environmental quality level was above “general”(> 5).However,different counties in the study area had obvious spatial differences of ecological environment quality.On the southern slope of Qinling Mountains,the ecological environment quality was significantly better.Good ecological environmental quality in the southern slope was 62.51%,while the northern slope was 54.00%.(4)The Moran’s Ⅰ of the ecological environment quality in the years of 2000,2010,2018 were 0.78,0.69,and 0.73,respectively,and the Moran’s Ⅰ of population density and economic density were 0.55 and 0.81.These indexes all passed the significance test and had strong spatial autocorrelations.Negative correlation between population density and ecological environment quality was obvious,the correlation coefficient was-0.57.Besides,the correlation coefficient between economic density and ecological environment quality was-0.41.(5)Population density and economic density had obvious spatial heterogeneity to the ecological environment quality.The higher impact areas of population density on the ecological environment quality were mainly in the southwestern Qinling Mountains,such as Ningqiang County,Nanzheng County.These areas where economic density had a serious impact on the ecological environment quality were in the southeast of the Qinling Mountains,which closed to the regional boundary,including Shangnan County,Hanbin District,Xunyang County and other places.