Characteristics of climate change in Hoh Xil and its impact on landscape pattern during 1970--2013.

Climate change has strongly affected landscape pattern of Qinghai-Tibet Plateau. Remote sensing data of 1990, 2000 and 2013 that contain six typical landscape types were chosen and analyzed by applying ArcGIS(10.0) and ERDAS(9.2) to illustrate the changes of landscape pattern in Hoh Xil National Nature Reserve. Climate data from 1970 to 2013 and its contribution to the landscape pattern change have been analyzed. The results showed that precipitation increased significantly at a rate of 20.3 mm/10 years, and annual average temperature increased at a rate of 0.38 ℃/10 years in Hoh Xil. Annual average temperature, precipitation, potential evapotranspiration and relative humidity were the key driving factors of glaciers and permanent snow, water body, alpine meadow and grassland area expansion, respectively. Glaciers and permanent snow, water body, and marsh wetland responded to 11-year cumulative climate effects, which is coincident with the weather cycle of the region; whereas alpine meadow and grassland were affected by 2-5 years short climate change, which indicated the fragility of the Hoh Xil region. In a word, climate change has an important influence in landscape change of Hoh Xil National Nature Reserve.