气候变化和人类活动对水资源影响的初探——以陕西省为例

A Preliminary Study on Impact of Climatic Change and Human Activity on Water Resources: Taking Shaanxi Province as An Example

针对陕西省14个小流域1961～2009牟的径流、降雨及潜在蒸散情况，运用Mann-Kendall非参数检验法、累积距平法分析了其变化趋势及径流突变点，使用敏感系数法分离了人类活动和气候变化对径流的影响，并基于Budyko假设，采用张氏曲线研究了各流域ω、β以及y的变化。结果表明：（1）研究区径流呈现显著下降的趋势，降雨量呈现不显著下降的趋势，潜在蒸散发的变化各区域不一致并且不同流域径流突变点出现的时间不一致，主要集中在1980年和1990年前后。（2）ω在陕北关中从北到南逐渐增大，在陕南比较小；卢陕南普遍较高，y陕南普遍较高。（3）陕北由于实施水土保持、退耕还林、黄土治理等措施，人类活动对径流变化的贡献率高于气候变化；关中地区由于工农业用水以及生活用水，人类活动的贡献率有所下降；在陕南由于下垫面性质，人类活动的贡献率亦占有很大比重。

According to the status of runoff, rainfall and potential evaporation in 14 small watersheds of Shaanxi province during 1961 ~ 2009, the author analyzed the variation trend and abrupt-change points of the runoff by using the methods of Mann- Kendall nonparametric test and cumulative departure, separated the impacts of human activity and climatic change on the runoff by using the sensitive coefficient method, and studied the changes in omega, beta, and gamma values of various watersheds based on the Budyko assumption and by adopting Zhang＇ s curve. In the studied area, the runoff showed a significant reduction tendency, rainfall revealed an un-significant reduction trend; the changes in potential evaporation in different regions were inconsistent. The abrupt-change points of runoff in different watersheds were different, and mainly concentrated in 1980 and 1990 or so. In North- ern Shaanxi and Guanzhong areas, the omega value increased gradually from the north to the south. The omega value was lower in Southern Shaanxi. Both the beta value and the gamma value were generally higher in Southern Shaanxi. In Northern Shaanxi, due to the implementation of such measures as water conservation, returning farmland to forestry, and loess management, human ac- tivity had a higher contribution rate to the runoff changes than climatic change. In Guanzhong area, due to the water use for indus- trial and agricultural sectors, and the domestic water, the contribution rate of human activity to the runoff changes was lower. In Southern Shaanxi, the contribution rate of human activity to the runoff changes also occupied a large proportion due to the nature of the underlying surface.