Spatial-Temporal Dynamic Evolution Characteristics of Land Use/Cover in the Middle and Lower Reaches of Yarkant River Basin in Recent 35 Years

Based on remote sensing image data the middle and lower reaches of Yarkant River Basin in 1982, 1990, 2000, 2010 and 2017, GIS technology was employed to analyze the land use/cover change of the area within the 35 a. The results show that:from 1982 to 2017, the proportion of cultivated land and construction land in the study area was continuously increased, the increasing extent is from 4.92% and 0.33% to 13.06% and 0.67%, respectively; The areas of forest land, grassland and unused land decreased by 8.43×10⁴, 4.48×10⁴ and 2.81×10⁵ hm², respectively. The change of wetland and water area is relatively minor, meanwhile, they generally showed a decreasing trend. The reduced area accounts for 0.08% and 0.14% of the total area of the River basin, respectively. Among all land use types, the change rate of cultivated land was the highest, up to 4.73%, which followed by construction land. The reduction of forest land, grassland, wetland and water area was mainly affected by natural factors such as annual average temperature rise, relative humidity decline and evaporation increase; The increase of cultivated land and construction land areas and the decrease of unused land area were mainly influenced by human factors such as population, gross domestic product of primary industry and sharp growth of GDP. In addition, the adjustment of policy factors also had a significant impact on land use/cover change in the study area.