Dipole spatiotemporal variations of river runoff in Eastern Tibetan Plateau
摘要
As a typical cold mountainous region, the Tibetan Plateau (TP) is characterized by complex water cycle processes, including snow and glacier melting, soil freezing and thawing, and rainfall runoff.Driven by global climate change over the past several decades, discharges of the major rivers on the TP have changed significantly, influencing the water resource utilization and ecosystem in the downstream regions.This study analyzed the discharge variations at 12 hydrological stations in six major exoreic TP rivers from 1980 to 2015, including Heihe River, Yellow River, Yangtze River, Lancang River, Nu River, and Yarlung-Tsangpo River.The precipitation variations in six basins were also analyzed based on five datasets.Results show that the runoff of stations located north of Changdu-Jiayuqiao decreased before 1999, and turned into an increasing trend after 1999.The stations located in the South TP had reversed runoff variations.Such variation can be described as a dipole spatiotemporal variation pattern.The precipitation variations over the TP were similar to that of runoff, showing a dipole pattern with reversed variations bounded by 32°N.These findings are helpful for runoff change mechanism understanding and projection under climate change, providing a scientific foundation for water resource management.