Multivariate Statistical Analysis for the Assessment of Hydrogeochemistry of Groundwater in Agbabu Area, S.W. Nigeria.

Abstract

Investigation into the hydrogeochemistry of groundwater in Agbabu Area in S.W Nigeria using physical and chemical parameters has been carried out. Samples were collected from eighty water points, comprising fifty two samples in the dry season and twenty eight water samples in the rainy season. The physical parameters measured in the field were pH, temperature, electrical conductivity and total dissolved solids. Chemical constituents analyzed for includes, bicarbonate, chloride, sulphate, nitrate, phosphate, calcium, magnesium, sodium, potassium, iron, zinc, copper, chromium, cadmium, lead, arsenic, nickel, total hardness, calcium hardness, manganese, turbidity, alkalinity, oil and grease for groundwater and were determined using established standard method. Descriptive statistics, correlation matrices, factor analysis, together with cluster analysis were used to gain an understanding of the hydrogeochemical processes in the study area. Factor analysis identify six main processes influencing groundwater chemistry which are sea water intrusion, mineral precipitation and dissolution, seasonal changes, cation exchange processes, human activity and decay organic matter. These six factors accounted for 74.6% of total variance of the groundwater.