Collective Response of the Regional Groundwater Flow System Underlying Major Doabs of Indus Basin Using Numerical Groundwater Flow Model and Satellite Data

Abstract

The current study investigates the behaviour of the aquifer underlying three major doabs of Punjab province, Pakistan. For this purpose a three dimensional groundwater flow model is developed then satellite data is used to further study the effect of monsoonal flooding on groundwater. A three-dimensional groundwater model was developed for the three Doabs including Chaj Doab, Rechna Doab, and Bari Doab. A steady-state model was calibrated against the heads of 1987 when it was in equilibrium conditions. 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, upon which millions of people depend for their sustenance. Under the prevailing scenario, a three-dimensional numerical groundwater flow model (Visual MODFLOW) has been used to evaluate the regional groundwater flow from the steady-state period of 1987 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 of 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 the 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 the 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 environmental DRSML QAU ii changes on the underlying aquifer could be minimized through long-term monitoring of the groundwater system and the adoption of integrated water resource management approaches ach in the future e. , In addition Groundwater Depletion and Extreme Flood Impacts on the Indus Basin Aquifer in Punjab Province are also studied in the present study. The Time-scale and mean annual area weighted temperature and precipitation based on climate research unit (CRU) data were acquired from variable periods between 1970-2015, from Pakistan Meteorological Department (PMD). The rainfall data of selected stations were segregated on a winter and summer basis, and trend analysis was performed on an annual and seasonal basis. The remote sensing dataset used for the present evaluation was based upon MODIS (on board Terra platform) 16-day composite product (MOD13Q1; tile h24v05) having 250 m resolution for the 2009-2014 period