Study on the Variation of Annual Runoff and Influencing Factors in Kuye River during the Past 60 Years

Abstract

In this study, observed runoff series from a hydro-station respectively named Wenjiachuan station in the Kuye river was manipulated for monthly annual variation analysis assisted by using nonuniformity coefficient and concentration degree(period).the cumulative filter methods was employed to detect the trend of inner-annual runoff. Based on meteorological and hydrological data of the Wenjiachuan hydrologic station from 1955 to 2015, the paper studied the variation tendency, the abrupt and periodic changes of annual runoff using the Mann-Kendall non-parametric test and accumulation anomaly curve. Double mass curve was used to estimate the impact of human activities and climate change on the runoff variation. The curve of seasonal runoff distribution for Wenjiachuan station appeared two peak patterns. The annual runoff declined markedly, the effect of climate on runoff decreased, the influence of human activities on runoff gradually increased the human activities are the primary factors leading to the reduction of annual runoff. In human activities, large-scale water and soil conservation measures and high-strength coal mining have produced significant effects on the annual runoff reduction in Kuye River.