Predicting behaviour of the Indus basin aquifer susceptible to degraded environment in the Punjab province, Pakistan

Rapid changes in the irrigated system due to climate change and drastic growth in urbanization and industrialization have raised serious concerns related to available groundwater resources of the Indus basin on which millions of people depend upon for their sustenance. Under the prevailing scenario, three-dimensional numerical groundwater flow model Visual MODFLOW has been used to evaluate the regional groundwater flow from the steady-state period of 1987 (used as a base to run the model for several simulation periods) up to the predictive period of 2030 for sustainable water resource management in the Indus plain of Pakistan. The steady-state calibration of the model indicated a close agreement between the simulated and the observed heads as indicative from the residual mean value of 0.10 m and an absolute residual mean of 0.47 m. The velocity vectors of the groundwater flow indicate that in most parts of the study area groundwater is discharged into the Jhelum and Chenab rivers. In the transient-state condition, groundwater levels indicated a rising trend till 1989, but as the irrigated area tends to increase continuously, the heads started to drop from year 1991 onward at an average rate of 0.45 m/year. The Bari Doab in the south appears to be more under stress than the Rechna and the Lower Chaj Doabs because of the overexploitation of groundwater, low flows in the Ravi River and less recharge from rainfall. The negative impacts of environment changes on the underlying aquifer could be minimized through long-term monitoring of the groundwater system and adoption of integrated water resource management approach in future.