Effects of Groundwater Withdrawal on the Interaction of Ex-Mining Pond, River, and Aquifer

Abstract

The paper aims at evaluating the effects of groundwater abstraction on the interaction of an ex-mining pond, river, and aquifer system of the Langat Basin in Malaysia through a 3D numerical modeling. Many mining sites have been left behind from the massive mining exploitation in Malaysia. In the current study, an artificial recharge from an ex-mining pond in the Langat Basin was proposed due to its capacity to store >30 million m3 of water. The 3D numerical model was developed using the Visual MODFLOW to simulate the effects of these activities. The calibrated model was utilized to simulate two cases. The ex-mining pond was without and with pumping in Case 1 and 2, respectively. Both results showed that the pond and aquifer were in influent condition. In Case 1, the total inflow to the aquifer system were approximately 15,819 m3/d of water from the constant heads, 1,202 m3/d from the Langat River, and 66,951 m3/d from the direct recharge of precipitation. In Case 2, due to the abstraction of groundwater, it caused a steep depression around the pumping well, river, and pond. The result of the water budget showed an increase rate of the inflow to the pumping zone from the pond and river around 6,945 m3/d compared to Case 1. The outcome of the current study provides the useful information of the interactions between the river, pond, and aquifer system as regards the groundwater abstraction in the Langat Basin.