Response of Wetlands Rise and Fall in the Changjiang River Source Region to Climatic Change
长江源头湿地消长对气候变化的响应

The Changjiang River Source Region is located in the hinterland of Qinghai-Tibet Plateau and in the north of Tanggula Mountain. Because the direct impact of human activities is limited, critical information can be found from the inter-related climate change and wetlands rise and fall. The impacts of climate change on the wetlands of the Changjiang River can be reflected. According to Gray correlation analysis, it can be found that evaporation plays an dominant role in the rise and fall of the total area of wetlands compared to other climatic factors, followed by the impact of precipitation. Climate in summer affects the rise and fall of wetlands more prominently than that in other seasons. The Changjiang River has a tendency of temperature rise, precipitation increase, and evaporation decrease, and it has a warm and humid trend since 1990. Its annual precipitation has been declining and its annual evaporation has an increasing trend in the 21st century. These are the significant driving forces for the rise and fall of wetlands. According to the remote sensing analysis, the total area of wetlands in the Changjiang River Source Region was increased by 353.22 km2, and the annual average increasing rate was 35.32 km2/a during 1990-2000, while it was reduced by 20.57 km2 during 2000-2004. These two periods showed the close relations between wetlands rise and fall and corresponding climate change.