Suitability Analysis of Groundwater for Irrigation in District Naseerabad, Baluchistan

Abstract

In Baluchistan, the dependency on groundwater for agriculture is even more significant due to its arid and semi-arid climate. District Naseerabad of Baluchistan, Pakistan, is characterized by its unique geographical and climatic features. Baluchistan receives scant and erratic rainfall, averaging less than 200 millimeters annually, which is insufficient to sustain agricultural activities. In these regions, the scarcity of rainfall and high evapotranspiration rates limit the availability of surface water, making groundwater the primary and sometimes the sole source of water for irrigation. The present study was conducted in District Naseerabad, Baluchistan, during the year 2023-24. There are 4 tahsils and 32 union councils (UCs) in the district of Naseerabad. There are no tubewells installed in the union councils without the union councils of Chhatter, Karor, Phuleji, Shahpur, and Bundi. So the water samples were collected from these 5 union councils. The water samples were analyzed for EC, pH, Chloride, Calcium, Carbonate, Bicarbonate, Calcium, Magnesium, Nitrate, Sodium, Sulfate, and Potassium. TDS, SAR. SSP, PI, MAR, and KR indicators were determined for water suitability. The EC of water was under permissible limits in UC Bundi. The pH was within permissible limits in all UCs. TDS were within permissible limits in UC Chhatter and Bundi. Bicarbonate, Chloride, Sulfate, Calcium, Magnesium, Sodium, Potassium, and Nitrate were within permissible limits in all UCs. Assessing the suitability of groundwater for irrigation involves evaluating several key indices that provide insight into the potential long-term impacts of using groundwater on soil health and crop productivity. The variations in SSP could be attributed to differences in geological formations, human activities, and agricultural practices across the union councils. For suitability analysis, SAR and SSP were within permissible limits in UC Chhatter and Bundi.  High PI values indicate that the water is likely to enhance soil permeability, while low PI values suggest a risk of reduced permeability due to sodium-induced soil dispersion. PIs were within permissible limits in UC Karor, Phuleji, Shahpur, and Bundi. MAR was over the permissible limits in UC Bundi. High KR values signify an elevated sodium hazard, which can lead to soil sodicity and degradation. KR were within permissible limits in UC Chhatter and Bundi. High MAR values indicate a disproportionate amount of magnesium, which can lead to soil compaction and reduced aeration, hampering root development and nutrient uptake.