The change of landscape pattern in arid mountain of the upper reaches of Shule River basin in Northwest China

Landscape changes are among the most important socio-economic forces of global as well as local environmental change. Mountain is a source of water in the arid regions, playing an important role in keeping ecological balance. This study focuses on the changes of mountain landscape in Shule River basin located in arid Northwest China. Based on the Landsat TM remote sensing satellite data of the study areas taken in 1986 and 2000, DEM (1:100000), using ArcGIS software, the landscape changes had been analyzed in the different elevation zones. The results show that: (1) Area of the sparse grassland is the largest in all the landscape types, the followed is rock. The vegetation of the study is 50%, and the dense grassland accounted for only 4.5%. (2) During the 15 years, the area of the dense grassland decreased 299.45 km² because of degradation, the mid-density grassland decreased 91.5 km². On the other hand, the area of the swamp meadow increased 168.92 km², the freezing-throwing rock increased 101.28 km², and the sparse grassland increased 95.3 km². (3) The grassland in lower elevation with 3500 m-3800 m were undergoing degeneration because of the global warming and over-grazing, and the altitude of 3500 m-3800 m was just the lower limit of permafrost distribution.