人类活动对地表水的影响

人类活动对地表水的影响可分为显性影响和隐性影响，以伊河流域为例分别分析了显性因素和隐性因素对地表水的影响，并对显性影响因素进行了还原，使地表水恢复到天然径流状态；对于隐性影响因素则通过径流系数的变化来进行定性分析。结果表明：①人类活动是导致天然年径流量减小的主要原因；②显性影响因素不但可以进行定量分析，而且可以还原；③隐性影响因素的分析比较复杂，原因主要在于不同地区的影响因素不同，因此目前只能对其进行定性分析。

Influence of Human Activities on Surface Water

The influence of human activities on surface water can be divided into dominant effect and recessive effect. The paper analyzes the influence of dominant effect and recessive effect on surface water respectively by taking the Yihe River basin as an example and reduces the affecting factors of dominant effect, rehabilitating the surface water to the natural runoff conditions; as to the affecting factors of recessive effect, it conducts qualitative analysis through the variations of runoff coefficients. The results show that a) the human activities are the main reason for the reduction of natural annual runoff; b) the affecting factors of dominant effect not only can do qualitative analysis, but also can be reduced; c) the analysis of influence of recessive effect is fairly complicated due to different affecting factors in different regions, therefore, it can only do qualitative analysis for the moment.