Evaluating groundwater suitability for irrigating crops using GIS technique in tehsil Noorpur, district Khushab

The quality of tube well irrigation water in Punjab, Pakistan, especially at shallow depths is changing gradually as a result of human activities and environmental changes. Many water soluble and insoluble minerals, salts and other constituents are present in groundwater, in various concentrations, which is used by the farmers as irrigation water for crop production. The most common mineral substances found in groundwater are compounds of calcium, magnesium, carbonates, bicarbonates, sodium and chlorides. A study was planned for quality testing, status, categorization and classification of groundwater in Tehsil Noorpur, District Khushab, with the use of global positioning system (GPS) for proper/judicious use, future research planning and advisory prospects. Total 275 water samples from each and every running tube well operating in the selected Tehsil were collected along with the global positioning (Longitude and Latitude) by using Magellan (Explorist-210, model of GPS) and analyzed in the laboratory to get attribute facts on groundwater quality indicators such as Electrical Conductivity (EC), Sodium Adsorption Ratio (SAR) and Residual Sodium Carbonate (RSC). The results indicated that considering EC, 20.7% samples fell under fit category while 6.9% marginally fit and 72.4% unfit. On the other hand, 39.3% samples were found fit in SAR parameter, 25.6% were marginally fit and 35.3% declared unfit. While on the basis of RSC, 73.5% were fit, 8.4% were marginally fit and 18.2% found in unfit criteria. On overall basis, 13.8% samples were fit, 0.1% was marginally fit and 80.3% were unfit for irrigation. From the study, it was concluded that the use of GIS technique helped to identify the areas having better quality and to provide a better guidance to researchers and farmers to adopt proper irrigation water application/management practices that could reduce the negative impacts of applied tube well water to agricultural lands and crop plants.