Research On The Ecological Environment Quality Change And Influencing Factors Of Chishui River Basin In Guizhou Based On Remote Sensing Ecological Index

As an ecological barrier in the upper reaches of the Yangtze River,the Chishui River Basin plays an important role in maintaining the biodiversity of the Yangtze River Basin and safeguarding its ecological security by virtue of its unique natural geographical environment.The Guizhou section of the Chishui River Basin occupies 55.53% of the total area of the basin.For a long time,the basin has been affected by the karst landscape,with high mountains and steep slopes,infertile land,and a very fragile ecological environment,and with the increase of population and the rapid progress of urbanization and industrialization,the ecological environment of the basin is under greater pressure.At present,there are not many studies on spatial and temporal dynamic monitoring of ecological environment quality in karst watersheds,and there is a lack of studies on the Guizhou section of the Chishui River Basin.It is of great practical significance to timely and accurately grasp the evolution of ecological environment quality and impact mechanisms in this watershed to maintain the stability of the ecosystem in the study area and promote sustainable regional socio-economic development.The Guizhou section of the Chishui River Basin was selected as the research object,based on the three phases of Landsat remote sensing images in 2000,2010,and 2020,combined with RS and GIS technology,using the principal component analysis method to construct the remote sensing ecological index（RSEI）,and supplemented with DEM,meteorological data and socio-economic data,to reveal the spatial and temporal evolution of ecological environment quality in the Guizhou section of the Chishui River Basin from the perspective of visualization The main findings are as follows The main conclusions are as follows.（1）The mean values of RSEI in the study area were 0.614,0.555,and 0.611 in 2000,2010,and 2020,respectively,and the overall ecological environmental quality showed a trend of the first decline and then rebound;the ecological environmental quality grades in the study area were mainly average and better,while the areas with poor,poor and excellent ecological environmental quality grades increased from 2000 to2020,respectively,The increase in the area of excellent grade is greater than the sum of the increase in the area of poor and poor grade,which indicates that the overall ecological environment quality of the study area has improved.It indicates that the ecological environment quality of the Chishui River Basin in Guizhou will continue to become better in the future.（2）From 2000 to 2010,the deterioration of ecological environment quality in the study area was mainly concentrated in the valley areas where human activities were more frequent.This indicates that the environmental protection and restoration in the study area are effective and the ecological environment has improved significantly under the influence of policy-driven and ecological restoration projects.（3）Analyzing the ecological environment quality of the counties in the study area,the ecological environment quality of Chishui City,Tongzi County,Bozhou District,Huichuan District,Jinsha County,and Xishui County showed a trend of first decreasing and then increasing,the ecological environment quality of Qixingguan District showed a decreasing trend,the RSEI of Renhuai City decreased by 0.067 from2000 to 2020,and the area of Dafang County with excellent ecological environment quality class in 2020 accounted for 38.27% of the county area,and the RSEI increased by a total of 0.082 during 20 years.（4）In terms of the factors affecting the ecological environment quality in the study area,the highest correlation between meteorological factors and ecological environment quality is relative humidity and annual precipitation,which are 0.848 and 0.824,respectively;the ecological environment quality is better when the elevation is 951～1195m and 1195～1474m,and the ecological environment quality shows an increasing trend with the increase of slope;the correlation between socioeconomic factors,year-end resident Among the socio-economic factors,the correlation between the total year-end resident population and the ecological environment quality is the highest,with a correlation of0.946;the ecological environment quality is better when the land use type is forest land and grassland,while the ecological environment quality of arable land,construction land,and unused land are worse;the ecological environment quality of the study area is more obviously influenced by policies.