黑河流域走廊平原地下水补给源组成及其变化

Characteristic and variation of groundwater recharge resources in the middle reaches of Heihe River basin

通过环境同位素、水文分割法和相关分析研究表明,祁连山区降水、冰川雪融水和基岩裂隙水通过出山口地表径流补给构成黑河流域走廊平原地下水主要补给源,具有年际和年内丰枯动态变化规律,与祁连山区降水量和气温的关联度分别为0.97和0.79,与平原张掖站降水量和气温的关联度分别为0.43和0.60。在自然径流条件下,祁连山区降水量变化是改变走廊平原地下水补给的主导因素,约占91%权重;气温变化是重要影响因素,约占9%权重。20世纪80年代以来祁连山区各补给源处于偏丰期。因此,近年来走廊平原地下水补给量相对50年代减少27.1%,人类活动是重要影响因素,急需加强科学调控。

Through the investigation and study with the environmental isotopic way and the hydrograph separation method, it is expounded that the rain, the groundwater and the snowmeh from the Qilian mountain area are the main resource to recharge groundwater in the middle reaches of Heihe River basin in the Northwest internal region. The recharge varyies dynamically during a year and has its yearly dynamic law. Its relation rate is 0.97 with rainfall, and 0.79 with air temperature at the Qilian station; the relation rate is 0.43 with rainfall; and 0.60 with air temperature at the Zhangye station. The rainfall variation in Qilian mountain area is the main factor to the variation of groundwater recharge in the middle reaches, whese in fluence rate is 91% in total rate, air temperature influence rate is 9%. The rainfall and runoff are all in abundant state since 1980, so that the decrease of groundwater recharge in the middle reaches of Heihe River basin is closely related with the human aetivites. Therefore to adjust to the human activity with scientific rules is the key hand to make the groundwater resources sustainable utilization in conformity with the principle of water cycle in Heihe River basin.