Using Statistical Analysis to Assess Shallow Groundwater Quality in Squatter Settlement of Dar es Salaam and Pwani Regions in Tanzania

Abstract

In Dar es Salaam and the Coastal regions, groundwater is the primary source of freshwater. Urbanization, industrialization, and agricultural activities have all contributed to the overuse of this resource, resulting in a decline in quality. In this study, we employ statistical analysis as a means to improve our understanding on groundwater quality. Seventy-one groundwater samples in squatter areas of Dar es Salaam and Coastal regions were used with 10 chemical parameters. Based on their dominant chemical compositions, hierarchical cluster analysis (HCA) classified samples into three main clusters. The clusters were then characterized with the help of the results from principal component analysis (PCA), Pearson's correlation coefficient of the chemical variables and piper diagrams. Cluster one was characterized by high salinity as a result of seawater intrusion. Cluster two was characterized by an intermediate salinity and high contamination. This was a result of sewage contamination and a moderate effect of seawater intrusion. With a low level of salinity and contamination, cluster three was found to be suitable for human consumption. The information obtained from this study demonstrates that the quality of the water has declined in some areas within the chosen regions. Therefore, prompt action is required to prevent further deterioration to the aquifers in the region.