Research On Water Ecological Function Zoning For The River Basin On The South Slope Of Qilian Mountains Based On GIS

Water ecological function zoning is the basis of "zoning,classification,staging and classification" of water environment.GS+ software is used to research spatial autocorrelation distance of each indicator elements and the autocorrelation distance among each factor and determine the secondary water ecological function zoning index and dominant index of the southern slope of Qilian Mountains.And then the ArcGIS 10.0 software space superposition method is put into application for the multivariate space analysis on selected indicators grid figure overlay so as to fix the partition boundaries and determine basin water ecological function division level and secondary partition map of the southern slope of Qilian Mountains.The specific conclusions are as follows:(1)The DEM raster map and river system raster map of the study area are used as two factors,and the river system is taken as the leading index of the first-level division of water ecological function for each watershed on the south slope of Qilian Mountain.According to the naming principle of large geomorphic unit + water system name + water ecological function area,the south slope of Qilian Mountain is divided into 4 first-level water ecological function divisions.Namely: Datong River water ecological function area in the southern slope of Qilian Mountain;Shiyang River water ecological functional area on the south slope of Qilian Mountains;Water ecological function area of Heihe River system on the south slope of Qilian Mountain and Shule River system on the south slope of Qilian Mountain.(2)Grid map of land use type,soil types,average annual NDVI,slope-to-slope,average annual precipitation and average annual air temperature,as well as runoff depth and evaporation capacity data are used in the research area.On the basis of the first division of water ecology on the south slope of Qilian Mountain,the second division is carried out.Taking land use type as the leading indicator,the naming principle of large geomorphic unit + river system name + main land use type + water ecological function area is adopted.The secondary division of water ecological function on the south slope of Qilian Mountain is obtained as 10.Namely: the southern slope of Qilian Mountain datong river basin forest water ecological functiondivision,farmland water ecological function zoning in Datong River basin on the south slope of Qilian Mountains,grassland water ecological function zoning in Datong River basin on the south slope of Qilian Mountains,wetland water ecological function division in Datong River basin on the south slope of Qilian Mountains,glacier/bare rock water ecological function division in Shiyang River basin on the south slope of Qilian Mountains,shrubbery water ecological function zoning in Heihe River basin on the south slope of Qilian Mountains,ecological function division of meadow water in Heihe River basin on the south slope of Qilian Mountains,ecological function division of marsh water in Heihe River basin on the south slope of Qilian Mountains,ecological function division of meadow water in Shule River basin on the south slope of Qilian Mountain,shrubbery water ecological function division of Shule River basin on the south slope of Qilian Mountain.