Response of Karst Spring Discharge to Precipitation in Semiarid Region of China

In karst regions of semiarid area, water moves from the recharge area to the discharge area, traveling long distance through the groundwater system in a period of years. Transit times through aquifers are a function of conduit geometry and connectedness, intensity and duration of the recharge event, and antecedent soil moisture. Often these factors are unknown or difficult to quantify. Therefore, the karst systems are inherent grey system. In this paper, we study the response of karst spring discharge to precipitation in semiarid area, China by using grey system model. As a representative of karst springs the Niangziguan Springs were selected as a case point. Consequently, the time-lag of 7 years between discharge and precipitation was identified. The key recharge areas of Xiyang County, Yuxian County, Heshun County, and Shouyang County in the Niangziguan Spring Basin were determined