Quantifying the Effects of Climate Variability and Direct Human Activities on the Change in Mean Annual Runoff for the Bahe River (Northwest China)

ABSTRACT Mo, S.; Li, Z.; Gou, K.; Qin, L., and Shen, B., 2018. Quantifying the effects of climate variability and direct human activities on the change in mean annual runoff for the Bahe River (Northwest China). Evaluating the impacts of climate change and human interference on runoff is critically important for regional water security. This study investigated the effects of climate variability and direct human activities on the change in mean annual runoff for the Bahe River in Northwest China. Precipitation, evaporation, and runoff data from 1959 to 2010 were analyzed at the Luolicun and Maduwang hydrologic gauge stations, and their temporal trends were explored using the Mann-Kendall test. A Mann-Kendall-Sneyers test and the double mass curve were applied to detect the statistically significant transition points in the hydrometeorological records. Results indicated no change point in upstream runoff in the Bahe River from 1959 to 2010; however, a clear transition point existed in midstream runoff in 19...