GROUNDWATER QUALITY MODELLING IN UPPER DENKYIRA EAST MUNICIPALITY OF THE CENTRAL REGION IN GHANA

Abstract

The aim of this study was to identify some common factors and develop a model for predicting Water Quality Index (WQI) in Upper Denkyira East Municipality of the Central region in Ghana. Factor Analysis with principal component method of extraction was used to identify the common factors and their factor scores were used as independent variables with WQI computed from the data as dependent variable to perform Multiple Linear Regression (MLR). Factor Analysis extracted hardness (Mn, Cd, Ca2+ and HCO3 - ), heavy metals (Pb, Cu, and As), salinity (Na+, Cl- and K+), organic pollutant (NO3 - , PO 4 3- , Zn and SO4 2- ) and chromium factor (Cr) as the common factors explaining almost 80% of the total variation in the data set. The results of the diagnostic check performed on the MLR model indicated that the model’s accuracy was good for predicting WQI yielding an adjusted R2 of 0.877. It was revealed that only the first three common factors (hardness, heavy metals, and salinity) were significant for predicting WQI. The results further showed that only salinity appeared to decrease WQI in the municipality. It is recommended that activities or factors contributing to higher concentration of hardness and heavy metals far above their recommended standard values in drinking water should be regulated in the municipality.