Author(s): Hongling Shi; Chunhong Hu; Yangui Wang; Qingqi Tian
Keywords: The Yellow River; Runoff and sediment load; Variations and trends; Reasons analysis
Abstract: The variation of runoff and sediment load of the Yellow River has suffered drama tic change under the impacts of the climate change and human activities. Based on the Mann–Kendal trend test, the sharp downward trends both proved in annual runoff process and annual sediment load process in the Yellow River, and their abrupt changes confirmed in 1986 and in 1980 respectively, according to the rank sum test. The factors of impacting on the changes of the runoff and sediment load are absolutely complicated. Through analysis on climate change, especially the precipitation, combined with the human activities, such as water diversion, reservoir constructions, water and soil conservation, etc., it is found that the increasing water consumption is the one of main contributions of the runoff decline after 1980, and the completion of Longyangxia Reservoir and its combined operation with Liujiaxia Reservoir have exerted a direct bearing on the abrupt change of annual runoff; In addition to the reduction of annual runoff, which will inevitably lead to the annual sediment load decrease, the combined effect of the water-soil erosion control and the reservoir construction have played a leading role in the trend and abrupt change of sediment load decline.