Comprehensive Analysis of Groundwater Suitability for Irrigation in Rural Hyderabad, Sindh, Pakistan

Abstract

An irrigation quality assessment for rural Hyderabad was made by determining the pH, EC, TDS and TH beside major cations and anions. This study employed various parameters to determine the suitability of groundwater for irrigation and its hydrochemistry. Permissible limits of major cations and anions revealed that approximately 26% of samples exceeded acceptable levels for Electrical Conductivity (EC), 87% for Ca2+, 89% for Mg2+, and 60% for Na+, while none exceeded the limits for K+. Conversely, 47% of samples for HCO3−, 91% for Cl−, and 100% for SO42−, NO3−, and CO32− proved suitability for irrigation. Notably, irrigation indices highlighted favorable results, with 100% conformity for SAR, SSP, RSP, and PI values, and substantial percentages of 78% and 85% for MH and KR values, respectively, affirming their suitability for irrigation practices. Employing the USSL diagram, 22%, 65%, and 11% of samples fall into the C2S1, C3S1, and C4S1 categories. According to the Wilcox diagram, 25%, 43%, 30%, and 2% are classified under C1, C2, C3, and C4 categories, respectively. The Gibbs ratio shows a concentration within the evaporation dominance, and CAI values showed positive ion exchange. Overall, Hyderabad’s rural areas are generally suitable for irrigation, apart from certain areas where water quality may not be acceptable for plants lacking high salt tolerance.

Keywords

• irrigation quality
• groundwater quality assessment
• USSL diagram
• chloralkaline index
• permeability index
• Kelley’s ratio