Archive | 2019
Groundwater Evolutionary Processes and Quality Characterization: A Case of Olbanita Aquifer System, Lower Baringo Basin, Kenya Rift
Abstract
A hydro-geochemical relation has been hypothesized through the analyses of physico-chemical data of a fractured volcanic rock aquifer located in the Lower Baringo Basin, Kenyan Rift. Datasets included 15 individual metrics determined in forty-two dry and wet season water samples obtained from six boreholes in the area. Aquifer evolutionary theory was postulated using sequential Principal Component Analysis and Hierarchical Cluster Analysis. In order to eliminate effects of scale dimensionality, PCA decomposed the variable data into four factors namely electrical conductivity, salinity, alkalinity and carbonate equilibrium with external pH control for the dry season, and salinity, carbonate equilibrium with external pH control, alkalinity and electrical conductivity, for the wet season. The main result depicted a major shift in variability factor from electrolytic conductivity (34.8%) in the dry season to salinity (23.5%) in the wet season. Ward’s linkage cluster analysis partitioned the aquifer into two spatially discrete associations; the western and the eastern entities respectively, in spite of their shared recharge area. These agglomerative scheduling validated in an integrative approach (with groundwater flow predictions using a calibrated petro-physical groundwater model for the area), linked the four factors to aquifer processes and three pathways: Fault permeability, weathering processes, and water-rock interaction. Statistical approaches are, therefore, useful in conceptualization of pollutant sources and their attenuation for effective groundwater quality management.