Evaluation of groundwater sustainability for agricultural irrigation in the Tolon District, Northern Region of Ghana

Abstract

Groundwater quality assessment is vital for ensuring water security, sustainable agriculture, and the well- being of the local communities in arid and semi-arid regions. This research aims to evaluate the suitability of groundwater quality for irrigation in the Tolon District, Northern Region of Ghana, using various irrigation water quality indices (IWQIs), including sodium adsorption ratio (SAR), potential salinity (PS), permeability index (PI), magnesium hazard (MH), total hardness (TH), residual sodium carbonate (RSC), and specific ion toxicity integrated with the inverse distance weighting (IDW) interpolation method. The IDW interpolation method in ArcGIS was used to plot spatial distribution maps of IWQIs. Twelve physicochemical parameters taken from 97 wells, including pH, electrical conductivity (EC), total dissolved solids (TDS), Ca2+, Na2+, K+, Mg2+, Cl−, NO3−, SO42−, CO32−, and HCO3−, were analysed. The study revealed that several parameters, such as EC, TDS, SAR, PS, PI, RSC, Na, K, and Cl, indicate that 82, 89, 98, 83.6, 44, 87.7, 80, 57, and 85% of samples, respectively, range from good to excellent quality during the rainy season. In addition, the MH index indicates that 82% of the samples are suitable for irrigation use. The IWQIs can help decision-makers and farmers identify sustainable groundwater-based irrigation regions.