GROUNDWATER FLOW PATTERNS AND DISTRIBUTION OF GEOCHEMICAL FACIES IN GOMBE AND ENVIRONS, NORTH EAST NIGERIA
Groundwater is the major sources of water supply for drinking, domestic, household, agricultural, industrial, recreational, and environmental activities in Gombe and environs. The research is aimed at delineating the groundwater flow patterns and distribution of geochemical facies in Gombe area and environs, northeastern Nigeria. Analytical results of 50 groundwater samples from the study area revealed that the order of abundance of the cations concentrations are Ca2+>Mg2+>K+>Na+ while those of the anions are HCO3->SO42->Cl->CO3-. The plotting of groundwater samples on piper trilinear and Schoeller diagrams delineate three groundwater facies as Ca-SO4, Mg-HCO3, and Ca-HCO3. Ca-SO4 accounts for 6% of the chemical facies, Mg-HCO3 accounts for 12%, and Ca-HCO3 Constitute 82% of the chemical facies. Ca-HCO3 facie is the dominant water type and is regarded as young water of meteoric origin that resulted from the dissolution of carbonates as a result of induced chemical weathering. From the recharge area groundwater flow South-West and also towards extreme North-East where it encountered groundwater of saline characteristics, and this leads to the evolution of Ca-SO4 facie. Also Ca-HCO3 facie in the recharge zone interacted with Na2SO4 where the Ca-SO4 water type evolved through reverse cation exchange. Another recharge area is around the central portion of the study area where groundwater flows southwest and north respectively and encountered rocks with plagioclase and clay composition within the aquifer. This lead to the evolution of Mg-HCO3. the Ca-SO4 water type is regarded as water of intermediate composition. Principal Component Analysis on the data indicates three factors which explain about 64.93% of the total variance, and suggests temporary hardness of water, salinity of the groundwater, diffused contamination and dissolution of bedrock materials as the dominant processes responsible for the modification of groundwater chemistry.
Authors : I. A. Kwami, B. A. Ankidawa, J. M. Ishaku and A. I. Haruna
Category : Open Access Volume (Issue) : 5(2) Date Uploaded : 24th June 2020