沮河流域径流变化特征及归因分析

径流变化的特征及归因分析对区域水资源规划和合理开发利用具有重要意义。本文以沮河流域为研究区域，利用线性回归法、五年滑动平均法及重标极差（R/S）分析法阐述水文要素的变化规律，通过Mann-Kendall突变检验和有序聚类法确定沮河黄陵站径流序列突变年份，利用基于Budyko假设的互补关系法及累积量斜率变化率比较法（SCRAQ法）对径流变化进行归因分析。结果表明，1967—2019年期间沮河流域年降水量呈上升趋势，年潜在蒸发量和年径流深呈下降趋势，且径流序列在1985年发生突变；两种方法计算得到的气候变化对径流减小贡献率分别为24.04%和11.71%，人类活动的贡献率分别为75.96%和88.29%，水利水保措施及煤矿开采等剧烈的人类活动是沮河流域径流减小的主要驱动因子。

Characteristics of runoff changes in Ju River basin and attribution analysis

Understanding the influencing factors of runoff changes and quantifying their contributions are important for regional planning and rational utilization of water resources. In this paper, a linear regression method, a five-year moving average method, and rescaled range (R/S) analysis method were used to illustrate the variation patterns of hydrological elements in the Ju River basin. The Mann-Kendall mutation test and an ordered clustering method were used to determine the years when sudden changes occurred in the runoff series at the Huangling Station. Then, the runoff series is analysed by using a complementary relationship method based on Budyko's hypothesis, combined with the Slope Change Ratio of Accumulative Quantity (SCRAQ) method. The results show that over the period of 1967-2019, the mean annual precipitation in this basin was on the rise, the annual potential evapotranspiration and annual runoff depth were on the decline, and the annual amount runoff changed abruptly in 1985. The contribution of climate change to runoff change in the Ju River basin was 24.04% and 11.71% by the two methods, respectively, and the contribution of human activities was 75.96% and 88.29%, respectively. Intense human activities such as water conservation measures and coal mining were the main drive of runoff reduction in the basin.