Abstract:
The reduction of water resources in the river basin has significant impact on the utilization of regional water resources, human living environment and economic and social development. The change characteristics and the abrupt point of runoff in the mainstream of the Weihe River Basin (WRB) were investigated to provide scientific support for water dispatching and water resources management in the WRB. The Mann-Kendall non-parametric test, cumulative anomaly, ordered clustering, moving t-test and R/S method were used to analyze the historical variation trend, abrupt point and future trend of runoff between 1956 and 2015 for six typical hydrological stations in the mainstream of WRB. Results indicate that: the annual and seasonal runoff at each station in the mainstream of WRB showed decreasing trends. The decreasing change magnitudes of runoff in the spring and summer seasons were greater than those in autumn and winter seasons at each station. From upstream to downstream, the magnitudes of decreasing trend got smaller and smaller. The upstream sites exhibited a process of increase-stationary-decrease, and there were 2 abrupt points in 1970 and 1993. The midstream and downstream stations exhibited a process of increase-stationary-decrease, and there were 2 abrupt points in 1968 and 1993. The annual and seasonal runoff Hurst index was more than 0.5 at each station in the mainstream of WRB, indicating that the future change characteristics of runoff were positively correlated with the historical change characteristics. The study shows that the runoff of each station in the mainstream of the WRB has a continuous decline trend. The administrative department of WRB should pay more attention to this issue and establish reasonable water resources management strategies for the WEB.