AN ANALYSIS OF TEMPORAL-SPATIAL FEATURES OF LAND USE AND LANDSCAPE PATTERN IN THE LOWER REACHES OF THE HEIHE RIVER

Using remote sensing techniques,GIS,and landscape pattern analysis software FRAGSTATS,the authors studied temporal-spatial change characteristics of the land use and landscape patterns of Ejina basin in the lower reaches of the Heihe river on the basis of LandSat TM data obtained in 1986 and LandSat ETM+ data obtained in 2003.The driving factors for the changes were also analyzed.The results show that the areas of grasslands,forestlands,water areas and cultivated lands were decreased during the 17 years,while the areas of the lands used for construction and the unused lands were remarkably increased.The extent of landscape fragmentation was decreased and its heterogeneity was obviously reduced.Moreover,the landscape diversity was also reduced and the landscape stability was lowered.The climatic warming-drying trend and the reduction of inflow to the lower reaches of the Heihe River constituted the main driving forces for land use and landscape pattern changes,and the unreasonable human activity accelerated this process.