D. Chandrasasi, S. Wahyuni, R. Asmaranto, P. Rubianto
For limestone formations, it is essential to understand the flow of shallow groundwater because karst systems are both complex and highly vulnerable to contamination. A Modflow groundwater flow model is required to achieve this objective. Using Modflow, a numerical groundwater flow modelling software, this paper constructs a conceptual model for understanding the movement of shallow groundwater within karst limestone formations. The model is applicable to steady-state conditions and considers geological, hydrogeological, and topographical data. Field data and water table readings are used to calibrate boundary conditions, recharge rates and hydraulic conductivities. Simulated results indicate that karst elements and the surrounding geological formations primarily influence flow paths. Recharge zones in the local area can be traced, and possible outlets of contamination from these water-bearing strata identifed. This research found that shallow groundwater flow in limestone tends to occur along abstraction potential lines and preferential flow zones, with a significant effect from seasonal recharge. This Modflow-based conceptual model for assessing groundwater dynamics, supporting water resources planning and contamination risk evaluation in karst regions. © 2026 Published under licence by IOP Publishing Ltd.
Water Resources Engineering Department, Faculty of Engineering, Universitas Brawijaya, Malang, Indonesia
