人类活动对黄河河川径流的影响

人类引水、耗水构成了流域水循环系统中的一个子系统,即侧支循环系统。与此对应,主干循环则是大气降水形成径流、通过各级沟道和河道汇入干流、最后流入海洋的循环过程。以黄河流域实测资料为基础,对侧支循环与主干循环进行了研究。研究表明,从20世纪60年代末、70年代初以来,侧支循环相对强度指标和侧支循环绝对强度与主干循环绝对强度之比呈明显的增大趋势,而主干循环相对强度指标则表现出减小的趋势。以年系列资料为基础,建立了一系列多元回归方程,以表达侧支循环强度指标、主干循环强度指标和侧支循环绝对强度与主干循环绝对强度之比与影响因子之间的多元回归方程。结果表明,灌溉面积、年降水量、年均气温变化对黄河侧支循环相对强度指标变化的贡献率分别为86.55%,2.18%,11.25%;灌溉面积、年降水量、年均气温变化和水土保持面积变化对黄河主干循环相对强度指标变化的贡献率分别为57.61%,20.78%,11.03%,10.57%。

Impact of human activities on the stream flow of Yellow River

The man-induced water diversion and consumption constitute a sub-system of the drainage basin water cycle system,namely,sub-system of side-branch water cycle.In this context,the main-stem water cycle is referred to as the water cycling processes including the runoff generation and movement from hill slopes and the diverse channels to the sea. Based on the data from the Yellow River,the man-induced side-branch water cycle and the main-stem water cycle are studied.The results show that since the late 1960s,the intensity of the side-branch water cycle and the ratio of the side-branch to the main-stem water cycles increase markedly,and the intensity of the main-stem water cycle decreases.Using the annual data,a number of multiple regression equations are established to express the relationship between the side-branch and main-stem water cycles and the influencing factors.The equations indicate that the contribution of variations in the irrigated land area,the annual precipitation and the annual temperature to the variation in the relative intensity of the side-branch water cycle are 86.55%,2.18%,11.25%,respectively,and that the contribution of variations in the irrigated land area,the annual precipitation and the annual temperature and the area of soil-water conservation to the variation in the relative intensity of the main-stem water cycle are 57.61%,20.78%,11.03%,10.57%,respectively.