Hydrogeologic assessment of escalating groundwater exploitation in the Indus Basin, Pakistan

Groundwater development has contributed significantly to food security and reduction in poverty in Pakistan. Due to rapid population growth there has been a dramatic increase in the intensity of groundwater exploitation leading to declining groundwater tables and deteriorating groundwater quality. In such prevailing conditions, the hydrogeological appraisal of escalating groundwater exploitation have become of paramount importance. Keeping this in view a surface-ground water quantity and quality model was developed to assess future groundwater trends in the Rechna Doab (RD) a sub-catchment of the Indus River Basin, Pakistan. Scenario analysis shows if dry conditions persist there will be an overall decline in groundwater levels of around 10 m for whole of RD during the next 25 years. The lower parts of RD with limited surface water supplies will undergo the highest decline in groundwater levels (10 to 20 m), which will make groundwater pumping very expensive for farmers. There is also a high risk of groundwater salinisation due to vertical upconing and lateral movement of highly saline groundwater into the fresh shallow aquifers. If groundwater pumping is allowed to increase at the current rate there will be an overall decline in groundwater salinity for the lower and middle part of RD because of enhanced river leakage.