Assessment of groundwater quality in Yaounde area, Cameroon, using geostatistical and statistical approaches

This paper presents the results of a survey carried out in 2010 and 2012 aimed at evaluating the quality of the groundwater resources as part of emergency program in drinking water of the Yaounde area, Cameroon. The groundwater quality parameters were analyzed from the 42 bore wells of the region, and the thematic maps were generated using geostatistical and statistical concepts. Ordinary Kriging were used as geostatistical approach for preparation of thematic maps of the groundwater quality parameters such as electrical conductivity (EC), total dissolved solid (TDS), bicarbonate, chloride, calcium, magnesium, iron, sodium, and potassium. Experimental semivariogram values were fitted well in spherical model for the water quality parameters, such as TDS, EC, bicarbonate, chloride, magnesium, sodium, and iron, and in exponential model for PH. Three factors were extracted by principal component analysis, which explains 91.82 % of the total variation. The first factor captures variables of EC, TDS, Cl-, Ca2+, Mg2+, Fe2+, Na+, K+, and TH. The second factor is significantly related to EC, TDS, and HCO3-, while PH accounted for the greatest loading for factor 3. Water Quality Index showed that 74.58 % of the samples were good for drinking, and the remaining were moderate and poor for drinking purpose. In fact, risk assessment of groundwater quality is useful for proper management of groundwater resources for minimizing the pollution threat.