中文摘要：

灞河径流决定其下游泸灞生态区的用水安全，开展其变化情势研究对有效管理区域水资源具有重要意义。基于灞河上游罗李村和中游马渡王水文站1959-2010年实测径流及流域降水、蒸发资料，采用肯德尔秩次相关法检验径流序列变化趋势、Mann-Kendall非参数检验法和累积距平法辨识各水文气象要素的突变点，并将累积量斜率变化率比较法用于定量计算气候变化和人类活动对灞河径流的影响程度。结果表明：①1959--2010年间上游径流量相对稳定，但中游径流量有减少趋势，且在1988年发生突变后呈现出显著的减小趋势。②气候变化和人类活动对灞河上游径流变化的贡献率分别约为97％和3％，对中游径流变化的贡献率分别约为37％和63％。未来只有合理开发、开源节流并举，才能保障区域可持续发展。

英文摘要：

River runoff is related to water security in the downstream region, and it is vital to water resources management to conduct reliable assessment to the impacts of climate changes and human activities. This paper presents an analysis on the impacts of these two factors on mean annual changes in the runoff of the Bahe River in Shaanxi, using the Kendall rank correlation method for temporal trends and based on the records of precipitation, evaporation and runoff at the Luolicun and Maduwang hydrological stations in the period of 1959-2010. The Mann-Kendall test and accumulative anomaly method were used in this study to detect the statistically significant change points in hydrometeorological series, and ratios of slope changes in cumulative quantities were compared to quantify the relative effects of climate and human factors on runoff variation. Results show that in this period, no change point was detected in the runoff of upper Bahe, while in the midstream runoff of 1988 a significant steep drop in the streamflow occurred, thus showing an evident change point. This rapid change indicates that, on the upper stream runoff, human activities had a relatively small effect but climate change was the main factor; on the midstream runoff after 1988, both climate and human factors played major roles in causing the significant runoff drop. Decomposition results reveal that, to the variations in the upper stream annual runoff, the two factors contributed 97% and 3% respectively, while in the midstream case thecorresponding contributions were 37% and 63%. Overall, human impact was dominant in the runoff decline of the Bahe River basin.