V2I9P13

Ground Water Examination Using Aquifer Model in Selected Geographical Zones in Southern Nigeria

Osuagwu  J. C.^1*, Nwakwasi N. L.¹, Ikpa P. N.¹, Onosakponome R.O.¹, Uzoukwu C. S.¹

Abstract

The analysis of the spatio-temporal differences of groundwater quality from different hydrological formations was done using Aquifer model. The southeast part considered was Imo State, Nigeria. Many iterations were carried out using this model, and based on the values derived from the processes, the discussions below were carried out. Four an interval of 4 weeks, many water samples were collected for an estimated period of 12 months. The collection was done in several hydrological formations of Imo State and were analyzed for different physiochemical parameters. These include Calcium (Ca),Magnesium (Mg), Magnesium hardness,  pH, electrical conductivity, total dissolved solid, total suspended solid, total solid, dissolved Oxygen, Biochemical Oxygen Demand, (BOD), Chemical Oxygen Demand, Nitrate, Bicarbonate, (HCO3)Potassium (K),Phosphate, (PO4-3), Iron, (Fe), total alkalinity, (CaCO3) total Chloride, (Cl-), Calcium hardness, total hardness, Sodium (Na) and Sulphate (SO4-2). Some formations were considered in Southern geological zones of Nigeria. In the list include considered the Alluvium Formation (AF), Benin Formation (BF), Ogwashi, Asaba Formation (OAF), Nsukka Formation (NF), Imo Clay Shale Formation (ICSF), and False Bedded Sandstones Formation (FBSF). From the results obtained, it was observed that during dry season, the average concentrations of total dissolved solids, chloride, nitrate, sulphate, total hardness and electric conductivity were higher were cross checked with the rainy season. The findings also show that the average concentrations potassium and bicarbonate were higher in rainy season when compared to dry season. Adopting a scale of 0 to 100, in accordance with World Health Organization permissible standards for safe drinking water, the water Quality Index was evaluated. The values for the case of dry season were derived and those for the season of rainy season were recorded. The values show that during dry season, groundwater samples from OAF and NF have excellent water quality, samples from BF, NF, and AF have good quality water and samples from ICSF have very poor water quality. The water Quality Index obtained during the rainy season indicate that water samples from BF, NF and AF have good water quality for drinking and agricultural applications based on national and international indices and standards while the water samples from OAF were of poor water quality. The water quality from ICSF is very poor and the water quality from FBSF unsuitable for drinking purposes. This suggests that there is need for continuous monitoring and treatment for acidic and high nitrate water to mitigate future pollution and ensure sustainable use of the groundwater resource. Aquiver Model was used to model and that gave an average correlation of 92.2% with the experiment data and a Root Mean Square Error of Estimate (RMSE) of 0.11

Keywords:

Hydrological formations Aquiver Model, Physiochemical parameters, Water Quality Index, Spatio-Temporal variability.