1956-2005年窟野河径流变化及人类活动对径流的影响分析

为明确水土保持综合治理和矿产资源开发引起的水文情势演变,以黄土高原水蚀风蚀交错区的窟野河流域为研究区域,选择近50 a的径流、降雨资料,运用非参数检验、R/S、小波分析、历时曲线方法,探讨径流的变化趋势、突变和周期,并利用降雨-径流多元线性模型估算气候变化和人类活动对径流的影响。结果表明:径流量表现出显著减少趋势,变率为-0.11×10⁸ m³/a,跃变时间发生在1979、1996年。与基准期(1956-1979年)相比,煤炭开发期(1997-2005年)的日径流量在5%、50%和95%的频率上减少程度均较水土保持效应期(1980-1996年)大。年径流的演变在9、18、32 a存在显著的周期。水土保持效应期气候变化与人类活动对径流变化的贡献率分别为58.62%、41.38%,煤炭开发期气候变化占21.75%,人类活动占78.25%,其中采煤活动占52.27%。煤炭开采是导致窟野河径流减少的主要因素,但是气候变化的影响也不可忽视,在进行水土保持综合治理和水资源合理规划时应充分考虑。

Variation of Annual Streamflow and the Effect of Human Activity in the Kuye River during 1956 to 2005

Based on meteorological and hydrological data of the Kuye River on the Loess Plateau from 1956 to 2005, the paper studied the variation tendency, the abrupt and periodic changes of annual streamflow using the nonparametric test, R/S analysis, wavelet analysis and frequency analysis. The empirical equation which shows the relationship between rainfall and runoff was established to estimate the impact of human activities on the runoff variation. The results showed that the annual streamflow in the river basin declined markedly with 0.11×10⁸ m³/a. The change points occurred in 1979 and 1996. The frequency analysis showed that, compared to period 1 from 1959 to 1979, the runoff reducing extent at 5%, 50% and 95% in period 3 from 1997 to 2005 was greater than that in period 2 from 1980 to 1996. The main periods are 9 a, 18 a and 32 a. Compared to period 1, the contribution rates of climate change and human activities were 58.62% and 41.38%, respectively in period 2. In period 3, the contribution rate of human impact increased to 78.25% of streamflow change, in which the impact of coal mining being 52.27%. The human activities were the main driving force for the decrease of runoff; however, the influence of climate change cannot be ignored. Their impacts should be taken into consideration when carrying out comprehensive improvement of soil and water conservation and rational use of water resource.