Analysis on runoff variation characteristics and its influence factors in the upper reaches of Hutuo River Basin

WANG Sheng;LI Wen-jing;WANG Jin-feng;College of Geographical Sciences,Shanxi Normal University;

river runoff;;climate change;;human activity;;Hydrological Sensitivity Analysis Method;;Hutuo River Basin

【Objective】 In order to provide theoretical basis for the optimal management,planning and decision-making of regional water resources,the variation characteristics in the hydro-meteorological factors were analyzed in the upper reaches of Hutuo River Basin,and the influence factors for runoff change were also quantitatively discussed from two aspects: climate change and human activities.【Method】 Mann-Kendall Trend and Mutation Test,Flow Duration Curve(FDC) and Hydrological Sensitivity Analysis Method were used for analysis.【Result】 From 1957 to 2013,the annual runoff series showed a significantly decreasing trend with an obvious abrupt change point at 1979,with a rate of 0.15×10~8 m~3/a.The inter-annual variations of runoff were both decreased before and after the abrupt change year.Compared with the trend during 1957～1979,the decreasing trend slowed down during 1980～2013,which was only 38% of that in the previous period.The decrease of average annual runoff had exceeded 50%.Meanwhile,the FDC has obviously moved down.Runoff distribution tended to be more uniform during the year.Based on the Hydrological Sensitivity Analysis Method,the recent contribution rates of climate change and human activities on the reduction of runoff were 26.7% and 73.3%,respectively.【Conclusion】 The decrease in precipitation might be the main reason for the rapid reduction of runoff in the upper reaches of the Hutuo River from 1957 to 1979,while the reason changed into the impact of human activities,which were embodied in the rapid increase in the agricultural and industrial water consumption and the urban domestic water use.