Application of isotope technology to protecting karstic water in the Gudui Spring Area

Abstract

Objective Karstic spring water is an important source of water supply for the karst areas of northern China. To rationally evaluate and scientifically exploit karstic water resources, it is important to identify the recharge, runoff and discharge conditions of spring water and to clearly depict the boundary of the spring area. Methods Targeting the issues of ambiguous border and unknown replenishment situations of the Gudui-Nanliang spring groups, this paper investigated and analysed the karst hydrogeological conditions of the spring area and the distribution characteristics of δD, δ18O and 87Sr/86Sr isotopes in the karstic water. The water-rock interactions and the hydraulic connection along the recharge-runoff path of karstic water were systematically examined by using isotope technique. Results The results show relatively large range of δ18O values in the karstic water. This is mainly attributed to the impacts of altitude effect, isotopic shift of oxygen in hot water, evaporation-induced enrichment and mixing of ancient sealed water. The distribution characteristics of δD, δ18O and 87Sr/86Sr in the karstic water provide strong evidence for the identification of the hydraulic connection of karstic groundwater. The formation of the Fenyangling geothermal field may be related to the water-rock interactions of the Mesozoic magmatic rocks that invaded the carbonate rocks. Also, the exploitation of karstic water in the north of the spring area will seize the karstic water resources in the spring area. Conclusion Overall, the investigation outcomes of karstic water isotopes in the Gudui-Nanliang spring area can provide a scientific basis for the management and protection of regional karstic water resources.

Keywords

• gudui spring
• karst water system
• isotope
• karst water protection