Overview of groundwater modeling technology and its application in karst areas with multiple-void media

Abstract

Due to the extremely heterogeneous distribution of karst and the multi-media nature of karst aquifer medium, the groundwater flow in karst water system presents complex and changeable characteristics. It follows Darcy flow law in the pores or fissures, and non-Darcy flow law in the karst pipelines, which brings great challenges to groundwater modeling in karst areas. This paper systematically worked through the main methods of karst water flow and solute transport simulation, summarized the current situation of groundwater simulation technology in complex karst multimedia systems, and pointed out the key issues that should be considered in the practical application of karst water modeling according to the characteristics of karst in south and north China. The main findings include: it is necessary to strengthen field investigations and observations to improve the accuracy of the characterization of the heterogeneity of karst aquifer media in the model. Furthermore, the research on the mechanism of karst water movement should be deepened to depict the flow characteristics and the water exchange mechanism in the karst multimedia. For the simulation of karst water systems in North China, the equivalent continuous porous media model can be selected, focusing on the coupling model of slow seepage in the karst pore fissure media with the rapid flow in the strong runoff zone. For the karst area in South China, it is suggested to consider the establishment of a coupling model between the distributed watershed hydrological model and the multimedia karst groundwater model that can describe the changes in various flow regimes in complex multiple-void media.

Keywords

• karst multiple-void media
• heterogeneity
• groundwater model
• watershed hydrological model
• conduit flow