Changes in flooding in the alpine catchments of the Tarim River Basin, Central Asia

Abstract

Floods are one of the most affective climate-related disasters, and climate change has altered their intensity and frequency worldwide. This study examined long-term changes in flood characteristics (including magnitude, frequency, and timing) in 30 alpine headwaters of the large endorheic Tarim River Basin, Central Asia. The contributions of climatic factors to flood (magnitude and timing) changes were investigated using numerical experiments in combination with the random forest approach. The following results were obtained: (1) Annual maximum flood peaks increased at most stations (89% stations) during 1961–2015 with increased flood frequency. Earlier flood peaks were observed in spring with a rate of 1.38 day per decade; for other seasons, changes in the occurrence time of flood peaks showed strong spatial variability. (2) Precipitation was the dominant factor for the increased flood magnitude in most catchments of the southern slope of the Tianshan Mountains, and temperature played a greater role in the northern Kunlun Mountains. (3) For flood timing changes, melt level height and precipitation were the most influential factors in the alpine catchments in the Tarim River Basin. The results provide information on the spatiotemporal variations of floods and their driving factors in this alpine basin under climate change.