ABSTRACT
The variation in runoff and sediment load of the Yellow River has suffered dramatic change under the impacts of the globe climate change and human activities. According to analysis nearly 65 years from 1950 to 2014 observed data of the main hydrologic-stations on the Yellow River, the sharp downward trends proved both in the annual runoff process and annual sediment load process according to the Mann–Kendal trend test, expect the head region of Tangnaihai station, and their abrupt changes confirmed in 1986 and in 1980 respectively for the respective station of the whole basin, according to the rank sum test. The factors of impacting on the changes of the runoff and sediment load are absolutely complicated. It is manifested that the reducing precipitation and the increasing water consumption are main contributions of the runoff decline, and the completion of the Longyangxia Reservoir and its combined operation with the Liujiaxia Reservoir have exerted a direct bearing on the abrupt change of the annual runoff; In addition to the reduction of runoff leading to the sediment load decrease, the effects from the reduced storm intensity, the combined soil erosion control and the dams construction have played a leading role in the trend and abrupt change of sediment load decline.
