Dynamic Changes of Plateau Wetlands in the Damqu River Basin, Yangtze River Source Region, China, 1988–2015

Abstract

The assessment of wetland changes on the Tibetan Plateau (TP) is an important component of global change research. The Damqu River Basin (DRB) lies within the southern source of the Yangtze River and is part of the core wetlands area of the Three Rivers Source Region (TRSR). We examined the distribution of wetlands across this region based on remote sensing image interpretations. The results revealed clear evidence of changes over the period between 1988 and 2015, with the ​​wetland area in 2015 being 8964.51 km2 (53.52% of the total basin). Wetlands at this time were concentrated between 4700 and 5000 m (upper limit: 5600 m), with land slopes between 0 and 6°, and a northward aspect. The data also showed that the wetland area decreased by 71.16 km2 between 1988 and 2015, equivalent to 0.79% of the 1988 total. The annual value of the normalized difference vegetation index (NDVI) decreased over 63.36% of the region within the DRB during 1988–2015. The area of three major lakes in the DRB declined from 2009 to 2015. The results of this analysis demonstrated that precipitation variation was the underlying cause of the observed vegetation index and lake area changes within the DRB between 1988 and 2015.