Response of carbonate aquifer to climate change in northern China: a case study at the Shentou karst springs

The response of carbonate aquifer to climate changes and ground water exploitation was studied at Shentou Springs. The springs consist of about 100 spring points. The long-term (1958–1999) annual average discharge of the springs is 6.86 m3/s. The discharge has diminished since the early 1960s. In 1993, the discharge (3.81 m3/s) was the smallest during the period of record. Data of restored spring discharge and precipitation during 1958–1999 were analyzed using a seasonal decomposition method. The result of analysis shows that the discharge of Shentou Springs responds remarkably to precipitation change. Lowering of ground water table and attenuation of spring discharge at Shentou in the last several decades are largely a response of the ground water system to the deficiency in regional precipitation in northern China. As compared with the effect of climate, human activities (mostly in the form of ground water abstraction) are secondary in affecting spring discharge. When the volume of exploited Quaternary ground waters that are partly recharged by karst waters exceeds 6400×104 m3/a, the impact on spring discharge becomes more intense.