Assessment Of Groundwater Quality Index For Agriculture And Domestic Purpose Of Taluka Sehwan, District Jamshoro

Introduction/Importance of Study:Groundwater has become a crucial source of freshwater globally, serving various purposes including domestic use, agricultural irrigation, and industrial applications. In regions like Taluka Sehwan, Sindh, Pakistan, where surface water sources are often compromised, groundwater plays a particularly vital role in sustaining local populations and economies. However, the quality of groundwater is increasingly threatened by contamination, necessitating comprehensive assessments to ensure its safety and sustainability.Novelty Statement:This study introduces a novel approach by combining the Water Quality Index (WQI) with GIS-based Kriging analysis to provide a thorough assessment and spatial visualization of groundwater quality in Taluka Sehwan. This method directly addresses the critical issue of contamination stemming from Manchar Lake, offering new insights and potential solutions for managing groundwater resources in the region.Materials and Methods:Thirty groundwater samples were collected from various locations within Taluka Sehwan. Sixteen key parameters, including pH, electrical conductivity (EC), and total dissolved salts (TDS), were analyzed in the laboratory. The Water Quality Index (WQI) and irrigation indices—Sodium Adsorption Ratio (SAR), Soluble Sodium Percentage (SSP), Magnesium Hazard (MH), and Permeability Index (PI)—were calculated to evaluate the suitability of the water for drinking and irrigation purposes. The results were then spatially analyzed using GIS-based Kriging, a geostatistical method that enables the visualization of the spatial distribution of groundwater quality across the study area.Results and Discussion:The WQI values in the study area ranged from 34.53 to 213.36. Only 13% of the groundwater was classified as "good," while 23% was deemed "poor," 7% "very poor," 30% "unsuitable," and 27% "unfit" for consumption. The overall WQI suggests that the groundwater in Taluka Sehwan is largely unsafe and non-potable, with only a few localized pockets in the northern region showing acceptable water quality. The Soluble Sodium Percentage (SSP) indicated that 83.33% of the water was categorized as "unsure" and 13.33% as "poor" for irrigation purposes. The Sodium Adsorption Ratio (SAR) results showed that 10% of the water was "excellent," 46.67% "good," 33% "allowable," and 10% "unsuitable" for agricultural use. The Magnesium Hazard (MH) and Permeability Index (PI) analyses revealed that 70% of the groundwater was "excellent" and 30% "safe" for irrigation. Despite the poor water quality for drinking, the irrigation indices suggested that 70-75% of the area could still be suitable for agricultural use. Spatial analyses highlighted significant heterogeneity across the study area, with lower concentrations of contaminants in the north and higher concentrations in the south.Concluding Remarks:The findings of this study underscore the urgent need for policies that prioritize the monitoring of groundwater pollution, research into the sources of contamination, and the development of mitigation strategies. Without proactive measures, the local ecosystem and communities face the risk of irreversible damage due to the deteriorating quality of groundwater resources.