Modeling for Sustainable Use of Groundwater in Chaj Doab, Indus Basin, Pakistan

Tuesday, April 13, 2010: 11:25 a.m.
Continental B (Westin Tabor Center, Denver)
Naveed Alam , Department of Water Management, Delft University of Technology, Delft, Netherlands
Theo N. Olsthoorn , Department of Water Management, Delft University of Technology, Delft, Netherlands
Chaj doab is an aquifer enclosed between rivers Jhelum and Chenab in the Indus basin, Pakistan. It spans about 1.4 million hectares between longitude 72°00′ - 74°15′E and latitude 31°00′ - 33°00′N. The rapid increase in agricultural demand and risk of irregular supply of irrigation water force the farmer’s trend towards groundwater use for guaranteed supply. This trend is leading towards declined water table, increased pumping cost and deteriorated quality of groundwater. Therefore groundwater numerical model of Chaj doab has been developed, calibrated and used to estimate the consequences of this existing trend and proposed sustainable groundwater use. The USGS-based MODFLOW-2000 and PEST have been used in this study. The digital elevation model (DEM), developed from SRTM and refined with the cartographic maps, has been used to create surface grid. The GIS techniques are utilized for the integration and development of spatial and temporal database, which is used in the present study for model development and calibration. CTD divers have been employed to monitor the water table fluctuations and determine aquifer properties at the selected locations.

Groundwater budgets and time series analyses of the study area depict the trend of seasonal variations in groundwater storage. Water balance studies for the period 1985-2008 indicate that the average annual discharge is more than the recharge.  This is the main cause of water table depletion in the model area. Different scenarios for the consequences of the existing pumping and proposed pumping are developed and evaluated to obtain a control on local and regional depletion of groundwater reserves. Various suggestions for sustainable groundwater use have been proposed in this paper. These options would provide a cost-effective water management system with on-demand availability of good quality groundwater for irrigation; as well as maintain the water table levels within the permissible limits.