Özet:

This study investigated the influence of geology and anthropogenic activities on water chemistry and quality in Agenebode and environs, southwestern Nigeria. Agenebode and environs is underlain by the Ajali and Mamu Formations of the Anambra Basin and is drained by the River Niger. 10 groundwater and surface water samples were collected and analyzed in the laboratory. The results revealed ranges of values for the parameters such as pH 5.8 - 6.7, EC 11.4- 228.1 µmhos/cm, Ca 0.48 - 2.73 mg/l, Mg 0.32 - 1.8 mg/l, Na 0.15 - 0.97 mg/l, K 0.28 - 2.73 mg/l, SO4 0.014 - 0.181 mg/l, Cl 10.4 - 124.1 mg/l, HCO3 30.3 - 85.4 mg/l, NO3 0.354 - 1.843 mg/l, Fe 0.081 - 0.304 mg/l, Mn 0.019 - 0.081 mg/l, Cu 0.011 - 0.063mg/l and hardness 2.512 - 14.205mg/l. The values of pH, Fe and Pb are above the limits in some of the samples (NIS, 2015; WHO, 2017). When plotted on a piper plot, the samples ranged from Magnesium Bicarbonate water type to Calcium Chloride water type, but the dominant type was the Mixed type and the distribution of ions was as follows Mg2+> Na++ K+>Ca2+> and Cl->> HCO3-> NO3-> SO42-. Correlation and regression analyses showed that the pH of the groundwater in Agenebode is influenced negatively by the TDS, EC, Salinity, COD, DO and the Major and Minor constituents. Hierarchical cluster analysis showed that the samples taken on and close to the River Niger shared similar characteristics, while samples taken further inland shared similar characteristics but all these samples differed in characteristics from the sample taken from the Mamu Formation. It is recommended that biological parameters should be measured in the study area in order to gain a clearer picture of the water quality especially from the anthropogenic point of view.

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