Demarcation of Groundwater System of Big Karst Spring: A Case Study of Eastern and Western Mountain Areas, Taiyuan Basin

This paper takes the eastern and western mountain areas of Taiyuan basin, Shanxi Province as a case study. On the basis of groundwater system theory and geographic information system (GIS) technique, some quantitative or semiquantitative structural information was first extracted from lithofacies paleogeography, geology, tectonics and hydrogeology in the study area, including the isolines of the base of regional karst-water aquifers, the projective section of both the planes of a fault and the mapping of karst-water system. The distribution of karst aquifers, the stratum permeability, the boundary characteristics and the relationship between the internal and external system all serve the classification of the karst-water system as local zone of saturation, regional zone of saturation and zone of passage. The research results show that in the western mountain area, the subsystem of Lancun spring and that of Jinci spring belong to the same regional karst-water system, and the subsystem of Xiye spring is an independent karst-water system. The majority of eastern mountain area belongs to the subsystem of Niangziguan spring. The subsystem of the eastern mountain area closely related to the groundwater system in the Taiyuan basin has no direct relation with the subsytem of Lancun and Jinci springs. These scientific evidences can effectively be employed to simulate the groundwater system and to evaluate the karst-water resources in the Taiyuan basin. Meanwhile, some new viewpoints about the boundary and the internal structure of the karst-water system have been presented with the demarcation method in this study area.