Resources Distribution and Efficiency
NING Yi-nan, YANG Xiao-nan, SUN Wen-yi, MU Xing-min, GAO Peng, ZHAO Guang-ju, SONG Xiao-yan
Changes in the water and sediments of the Yellow River are associated with ecosystem security and quality development throughout the basin. It is of great significance to quantify the contribution of climate change and human activities to the reduction of runoff in order to analyze the causes of water and sediment changes in the Yellow River. Due to different research scales and research methods, the factors and influence degree of runoff variation vary greatly. Therefore, based on the same time scale, this paper uses MK trend test and Double Mass Curve method to systematically analyze the changing trend of hydrological elements in four typical basins (Huangfuchuan, Kuye River, Wuding River and Yanhe River) in the middle reaches of the Yellow River from 1960 to 2015. The Budyko water heat balance equation is used to clarify the role of climate change and human activities in the water and sediment change of the basin. The results showed that the runoffs in Huangfuchuan, Kuye River, Wuding River and Yanhe River basins all decreased significantly from 1960 to 2015 (P<0.01), and the runoffs in 1979 and 1999 experienced sudden changes without significant variations in precipitation. Compared with the base period (1960-1979), the contribution rate of climate change to runoff reduction in the P2 period (1980-1999) reached 64%-76%; with the large-scale implementation of the project of returning farmland to forestland and grassland, human activities in the P3 period (2000-2015) have become the main influencing factor leading to runoff reduction, with a contribution rate of 71%-88%.