利用树轮揭示人类活动对柴达木盆地巴音河径流量的影响

评估人类活动对径流的影响,对区域水资源开发管理有借鉴和指导意义。利用柴达木盆地北部山区7个祁连圆柏树轮宽度数据,建立区域平均树轮宽度年表。通过对区域平均树轮宽度年表与巴音河水文站径流量进行相关、滑动相关和回归分析,模拟了巴音河1956—2002年6月天然径流量变化,进而分析出人类活动对径流量的影响。结果表明: 树轮平均年表与6月径流量的相关性最强(r=0.63,P<0.01),两者相关系数在1986年后下降;基于1956—1986年树轮平均年表与6月径流量建立的转换方程,方差解释量为50.8%;基于转换方程模拟的1987—2002年径流量均值与实际观测径流量存在显著差异,模拟均值比观测均值大3.01 m³·s^-1。上游人类活动已经对巴音河径流量的变化带来了明显的影响。因此,在巴音河流域未来水资源开发利用规划中,有必要将人类活动作为重要的影响因素加以考虑,以保障可持续的水资源利用。

Impacts of human activity on Bayin River runoff as revealed by tree rings in Qaidam Basin,China

Evaluating the impacts of human activity on river runoff has important implications for regional water resource management. Here, we used seven tree-ring width chronologies to establish a regional mean tree-ring width chronology from the northern mountain of Delingha, Qaidam Basin. We conducted the correlation, moving correlation and regression analysis of regional mean tree-ring width chronology with runoff data from Bayin River gauge station. Then, we stimulated the June runoff of Bayin River from 1956 to 2002. The results showed that the highest correlation coefficient was found for June runoff (r=0.63, P<0.01), and their moving correlation coefficient decreased after 1986. Based on the stable relationship between tree-ring width chronology and the June runoff during 1956-1986, we built the reconstruction function, which was explained 50.8% of observed runoff. The stimulated runoff during 1987 to 2002 was significantly higher than the observed runoff (3.01 m³·s^-1, P<0.001). These results indicated that human activity from the upper river had significant impacts on Bayin River runoff. Human activity should be considered as an important factor to protect security of sustainable water resource utilization for future water resource development and utilization in Bayin River region.