Groundwater Assessment and its Implication for Irrigation in Selected Coastal Areas of South-Western Nigeria

Physicochemical and ionic characteristics of groundwater aquifers have been tremendous importance in water applications. Groundwater selected coastal communities (Badagry, Epe, Ikorodu, Ilaje/ese-odo) south-western Nigeria was assessed for domestic irrigation suitability. One hundred ninety-two (192) samples were obtained analyzed chemical composition major ratio over a period four seasons using standard methods. Results indicated abundance ions the order HCO3– > Cl–> SO42– anions, K+ Na+ Ca2+> Mg2+ cations. Piper's diagram revealed calcium (Ca2+) magnesium (Mg2+) as dominant cations, while sulphate chloride anions with mixture two types: Ca–Cl mixed Ca–Mg–Cl. The presence facies type suggests potential ion exchange (Na2+ Ca2+) reaction these aquifers. Cation exchangeable values (CEV), molar ratios Mg/Ca, HCO3/Cl, Na/Cl, showed high (>1) across all locations indicating occurrence saline ingression samples, especially during dry spell. increasing K+, Na+, Cl– calculated indices influence seawater intrusion. However, total hardness that very soft nature. Irrigation quality suitability, by sodium adsorption (SAR), permeability index (PI), percentage (PS) varied location, showing will cause soil deterioration poor crop performance if intensively used without proper precautions.