全球变化知识资源中心

Wetlands, as the transition zones between land and aquatic systems, are one of nature's most biologically diverse ecosystem types and are important environments for humans. In arid deserts, the roles of wetlands are particularly important. The Hongjian Nur region (HJN), which has the largest desert freshwater lake in China, is not only a national reserve but also the largest breeding ground for Larus relictus in the world. However, due to climate change and human activities, extensive wetland changes have occurred in the HJN region in recent decades. To investigate the changes of wetlands in the HJN region, the dynamics of wetlands and surrounding land cover types in this region over the past three decades were studied using remote sensing. In addition, how these dynamics have been affected by climatic and human factors was analyzed. The results suggested that the area of wetlands presented a decreasing trend over the studied time period from 62.54 km(2) to 35.89 km(2), with an average rate of change of -0.66 km(2)/year. The reduction in wetland area was mainly caused by climatic and human factors. The contribution of temperature and precipitation to vegetation growth were small, and the impacts of human activities on the wetland areas of the HJN region were mainly caused by agricultural irrigation, artificial surface expansion and ecological water use. The results also suggested that human activities in arid regions may have negative impacts on fragile wetland ecosystems.