Ecosystem changes revealed by land cover in the three-river headwaters region of Qinghai,China(1990–2015)

查看全文 作　　者：XuWei [1]Sun;Sen [2]Li;XiaoHui [2]Zhai;XiaoXu [3]Wei;ChangZhen [2]Yan 机构地区：[1]Gansu Academy of Eco-environmental Sciences,Lanzhou,Gansu 730020,China;[2]Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China;[3]College of Social Development and Public Administration,Northwest Normal University,Lanzhou,Gansu 730070,China 出　　处：《Research in Cold and Arid Regions》索引2023年第15卷第2期,共7页 基　　金：supported by the Second Tibetan Plateau Scientific Expedition and Research Program (Grant No.2019QZKK0608);the National Nature Science Foundation of China (Grant No.41730752 and No.41971277). 摘　　要：The Three-River Headwaters Region(TRHR) of Qinghai Province, in the Tibetan Plateau of China, is the main source of the Yangtze, Yellow, and Lancang rivers, and is very significant to the security of freshwater resources for China and southeastern Asia. It is a critical ecological region of China for its ecological functions, and has been changed or even degraded in recent decades owing to climate change and human pressure. To effectively protect and restore the degraded ecosystems, the Chinese government initiated a series of ecological conservation projects in TRHR. It is essential to quantitatively assess ecosystem changes and their relationship to driving factors for indepth understanding of long-term changes of ecosystems and effects of ecological restoration policies and offer practical insights for ecological restoration. Here, land cover data has been interpreted with the series data of Landsat during 1990–2015. The patterns of different ecosystems and their developing process have been derived from land cover change. The results show that ecosystem types in TRHR include forest, grassland, cropland,wetland, artificial surface and barren land, accounting for 4.51%, 70.80%, 0.15%, 9.47%, 0.16% and 14.90%,respectively. Barren land converted to wetland was the significant ecosystem change from 1990 to 2015. Increases in temperature and precipitation and implementation of ecological rehabilitation helped maintain relatively stable ecosystem patterns. It is necessary to continue ecological projects to improve and/or maintain the ecosystems in TRHR because there is still a risk of land degradation under increasing climate change and human activity. 关 键 词：Three-river headwaters region Ecosystem change Land cover Affecting factor