GIS BASED ASSESSMENT AND DELINEATION OF GROUNDWATER QUALITY ZONES AND ITS IMPACT ON AGRICULTURAL PRODUCTIVITY

摘要

The utilization of groundwater for irrigation is rapidly increasing due to constrained canal water supplies. The spatial fluctuation of groundwater quality widely varies, so mapping has become necessary for better management of this precious resource. Therefore, to delineate groundwater quality zones in the Central East of Punjab-Pakistan, geographic information system (GIS) was used. A hydro-economic model was also developed to observe the impact of groundwater quality on agricultural economics. Three groundwater quality zones such as good (zone-1), marginal (zone-2) and hazardous (zone-3) were classified according to the available criteria. The final maps of pre and post-monsoon season showed that area of good, marginal and hazardous quality groundwater was ranged between 35.81 to 41.19%, 36.63 to 31.53% and 27.55 to 27.27% of the total area, respectively. It was found that the benefit cost ratio in zone-1 was 2.53, which was much higher than zone-2 (2.24) and zone-3 (1.88). The results also showed that with the 1% increase in the value of electric conductivity (EC), the gross value product (GVP) was decreased significantly by 0.080 and 0.526 % in zone-2 and 3, respectively.