Analysis of runoff characteristics and contribution rate in Xiying River Basin in the Eastern Qilian Mountains

The impact of climate change on the basin is extensive and long-lasting, which will have a profound impact on the natural ecosystems, water resources, agriculture, and human production and life throughout the basin. An in-depth understanding of the impacts of climate change on watersheds and quantitative assessments will help to scientifically plan and manage water resources and protect the integrity of natural ecosystems. In this paper, temperature, precipitation and potential evapotranspiration data were used to analyze the response of Xiying River runoff to climatic factors in the Qilian Mountains by sliding correlation and wavelet analysis. M-K test and cumulative anomaly (CA) were used to analyze the climatic factors and runoff in the basin and use the pettitt method to test. Finally, the cumulative rate slope change rate comparison method was used to analyze the change of precipitation, potential evapotranspiration and snow-melt water contribution to runoff in this area. The results showed that temperature, precipitation and potential evapotranspiration had obvious mutations from 1961 to 2012 in this region. Compared with temperature and potential evapotranspiration, the precipitation showed greater impact on runoff. In addition, the contribution rate of ice and snow melt water to runoff was relatively larger in 1990 - 2002 compared to 1961-1989, followed by precipitation and evapotranspiration; the increase of the precipitation contribution rate became the main factor to runoff, followed by ice and snow melting and evapotranspiration compared to 1990-2002 in 2003-2017.