Irrigation Water Quality Assessment and Hydrochemical Facie of Oguta Lake, Southeastern Nigeria

Abstract

The quality of water for irrigation is important for maintaining soil properties and improving yields. This study assessed the quality of Oguta Lake for irrigation using irrigation indices of SAR, %Na, PI, KI, and MH. Twenty (20) water samples were collected in the study area over two seasons and analyzed using standard methods. The results indicate that the water is excellent for irrigation with values of SAR, %Na, PI, KI, and MH ranging between 0-0.007, 0-0.18, 213-329, 0.0006-0.0022, and 0.06-13 in the dry season and 0.001-0.154, 0-3.57, 212-328, 0.008-0.0477 and 4.46-13.21 in the rainy season respectively. Piper and Durov diagrams were used to determine the hydrochemical facie of the water and both plots indicate that the water type is dominantly Ca2+ - Mg2+ - HCO3- and this water type is typical of fresh water. The piper plot also shows that weak acid exceeds strong acids and alkaline earth (dominant metal ions) exceeds alkalis. The concentration of major cations and anions follows the trend, Ca2+ > K+ > Mg2+ > Na+ and HCO3 > SO42- > CO3- > Cl-, respectively.