LAUSR

Jinci Spring is a popular karst spring in northern China and has important historical and cultural value. The spring stopped flowing since it first dried up on April 30, 1994, which has resulted in further water deficit in the area. This study aimed to further the sustainable utilization of Jinci Spring and used long-term karst groundwater monitoring data to investigate the causes of the drying up of Jinci Spring using the capture principle. The sustainable yield and the sustainability threshold of karst groundwater were quantified, and the ecological water level restrictions for early warning and water supply were determined. A simple two-dimensional (2D) numerical model of karst groundwater was used to design three restoration and protection scenarios under which the dynamics of karst groundwater level were simulated and the restoration and protection scheme was optimized. The results showed that (1) climate change and the long-term consumption of karst aquifer storage are the key factors contributing to the drying up of Jinci Spring; (2) the range of sustainable yield of karst groundwater is 0.622–2.35 m3/s; (3) the sustainability threshold of karst groundwater is (12.35 × 108 m3, 13.91 × 108 m3); (4) the ecological water level restriction for early warning and the ecological water level restriction for water supply are 803.35 meter above sea level (m asl) and 803.21 m asl, respectively; (5) Scenario 1 is the optimal restoration and protection scheme that meets the ecological criteria for Jinci Spring. The results of this study can provide an important basis for the implementation of the ecological restoration program for Jinci Spring.