The Dawu water source is a rare, large-scale groundwater source located in northern China. The water supply function from this water source has, however, been lost due to anthropogenic pollution. In order to fully utilize valuable groundwater resources, a new water source of urban domestic water in Liu Zheng is planned. In this study, a tracer test and a numerical simulation method are used to examine the hydraulic connection between the Liuzheng water source and the Wangzhai industrial park; to optimize the exploitation layout of the Liuzheng water source and Dawu water source; and to propose the extent of the Liuzheng water source protection area. Results indicate that: (1) Karst development in the study area is uneven, and the Wangzhai area is a recharge area of the Liuzheng water source; (2) it is predicted that the groundwater flow field will not be significantly changed when a groundwater volume of 150,000 m³/day is exploited from the Liuzheng water source; (3) it is predicted that the proposed chemical park in Wangzhai will gradually pollute to the groundwater in the northern area of Liuzheng; and (4) results using the empirical formula method and the numerical simulation method indicate that the area of the primary protection area of the Liuzheng water source is about 0.59 km², and the area of the secondary protection area is about 14.98 km². Results from this study provide a certain technical basis for the exploitation and protection of groundwater in the Liuzheng water source.

Karst water supplies freshwater to approximately a quarter of the global population and plays a crucial role in supporting the socioeconomic development of karst regions. As a key indicator for assessing and managing karst water resources, karstic water storage variation is influenced not only by the complex structure of karst aquifer media but also by the variability in natural precipitation infiltration. Based on the hydrogeological conditions of a typical karst aquifer system in northern China, this study developed a three-dimensional physical experimental setup and established a corresponding groundwater flow numerical model coupled with equivalent porous media and conduits. The factors affecting spring flow recession were investigated from a source–sink perspective. Precipitation events were categorized into two types: those with the same duration but different intensities and those with the same total volume but different intensities. The influence of varying precipitation events on the estimation of karstic water storage variation was quantitatively evaluated using the exponential fitting method, based on the analysis of spring flow recession curves. These findings could provide scientific guidance for the development, utilization, and protection of karst water resources.