中文摘要：

利用汾河河津水文站1950年以来的水文资料。应用多种统计分析方法．系统分析了汾河水沙的季节及年际变化规律，并且对人类活动导致的年径流变化影响进行了估算。研究表明．汾河流域水沙年内分配极不均匀．年内不均匀系数有明显上升趋势．且越到近期稳定程度越低。水沙的年际变化剧烈．且在20世纪80年代之后年径流基本都是枯水时段。应用累积滤波器对汾河水沙变化趋势进行分析，结果显示，汾河流域水沙均呈减少趋势．且泥沙变化幅度大于径流变化。通过降水一径流双累积曲线及对天然径流的还原分析表明．径流变化趋势在1964年发生明显偏离，从多年平均值来看，人类活动导致的径流减少量占径流减少总量的75．912％．人类活动是汾河流域径流减少的主要因素．

英文摘要：

Based on the hydrologic data from the Hejin station of Fenhe River since the 1950s, the seasonal and annual change of runoff and sediment was analyzed,and the influence of human activities on the runoff was estimated. The results show that the seasonal distribution of runoff and sediment was quite uneven,while there was obvious increase in the Cry and the degree of stability became lower and lower. The annual distribution of runoff and sediment was different in great scope, annual runoff was rainless period since the 1980s. To analysis the trend of runoff and sedi- ment change using the cumulative filter method, the results show that there was obvious decline, and the variation of sediment change was greater runoff change. Analyses of double mass curve of annual runoff and precipitation showed that the decline in the runoff occurred in 1964. On average, 75.912% of total annual runoff reducition was induced by human activities.Human activities were main reasons of runoff reduction in Fenhe River basin.