Analysis on Runoff Trend and Influence Factors in Weihe River Basin
WEI Hong-yi1, LI Jing2, WANG Jiang1, TIAN Peng1(1.College of Resources and Environment, Northwest A & F University, Yangling, Shaanxi 712100, China; 2.College of Water Resources and Architectural Engineering, Northwest A & F University, Yangling, Shaanxi 712100, China)
Aimed at the stream flow cut-off of Weihe river basin at Huaxian station, it is important that the runoff trend and influence factors are analyzed in this area. According to the data of runoff in Weihe river basin from 1956 to 2000, the changing trend of runoff at Huaxian station is analyzed by using the R/S analysis (Rescale Range Analysis). At the same time, the influence factors of runoff are analyzed. Results show that the Hurst coefficient is 0.778 4, showing that the runoff trend is on the persistent decline. The annual average runoff had been reduced by 3.79 ×109 m3 from 1970 to 2000, compared to the runoff from 1956 to 1969. Among the influence factors, the reduction influenced by climate is 1.96 ×109 m3 and the reduction influenced by human activities is 1.83 ×109 m3, amounting for 51.7% and 48.3% of the total reduction, respectively.