Guiding Groundwater Policy in the Indus Basin of Pakistan Using a Physically Based Groundwater Model

AbstractThe exponential increase in groundwater usage over the past few decades in the Punjab province in Pakistan is responsible for the significant groundwater table decline in many parts of the province, leading to an urgent need for policy measures to better manage groundwater use. A better understanding of the underground water balance is necessary for drafting informed groundwater management plans. With limited data, this study develops the first physically-based groundwater model for the entire Punjab province. Using the calibrated provincewide model, simulations are performed to evaluate groundwater dynamics in the future under different scenarios. These scenarios comprise controls on groundwater pumping, canal infrastructure improvements, and precipitation changes. The impacts of these scenarios are highlighted with the mapping of changes in water table, pumping cost, and waterlogged area. The results show that changes in both groundwater abstraction and seepage from the canal system into the aquifer significantly impact groundwater heads, whereas the effect of changing precipitation is negligible. Under status quo conditions, the average provincewide pumping cost is projected to increase by 270% in 23 years. The findings emphasize the heterogeneity in groundwater conditions across Punjab and highlight the need for region-specific management of groundwater resources.