Origin of Dissolve Ions in Groundwaters in the Northern Densu River Basin of Ghana Using Stable Isotopes of 18O and 2H

Abstract

Stable isotopes of oxygen-18 and deuterium content in groundwater, surface water and rainfall in the northern part of the Densu river basin were studied with the main aim of identifying the origin and sources of ions in the groundwater in the area. The conversion of stable isotopes to d-excess was also exploited as a complementary tool to understand the processes of recharge. A comparison of the isotopic data with the rainfall, Local Meteoric Water Line (LMWL) and Global Meteoric Water Line (GMWL) indicates that the groundwater in the study area is mainly meteoric with few groundwater and all the surface water showing an evidence of evaporation. The study has also shown that, mineral dissolution from the geology is the main factor controlling the chemistry of the groundwater with evaporation having a minimal effect. The d-excess values show that the groundwater has undergone dilution with the rainfall and this is observed from the decrease of the d-excess of the groundwater with increase in Oxygen-18. This observation also suggests a modern day recharge to the groundwater

Geographic Distribution of Registered Packaged Water Production in Ghana: Implications for Piped Supplies, Groundwater Management and Product Transportation

“…Aquifer vulnerability within basement rocks which underlie the Basin is high, since the shallow weathered regolith in the granite-gneiss complex, which dominates the Basin, is particularly vulnerable to pollution and over-abstraction due to low storage and variable yields. High nitrate and chloride levels, above World Health Organisation guideline values, are reported for many boreholes and wells within the central and lower Basin, which has extensive agricultural land use and urbanization [44]. There is little published data on microbiological contamination in groundwater in the Basin, though high borehole turbidity has been widely observed across the Basin (e.g., [45]), which strongly suggests that faecal contamination of water could affect any sachet producers reliant on shallow wells and poorly constructed boreholes.…”

Application of Water Quality Index (WQI) and Multivariate Analysis for Groundwater Quality Assessment of the Birimian and Cape Coast Granitoid Complex: Densu River Basin of Ghana

“…The granites in the basin are less fractured and weathered, hence groundwater occurrence is moderately low. The granitic aquifers thus formed are usually phreatic to semi-confined in character, structurally dependent and often discontinuous in occurrence (Gibrilla et al 2010b;Buckley 1986). However, in the northern portion of the granitic formation relatively high productive wells exist.…”

“…The Birimian formations to the northwestern portion of the basin are generally well folded and deeply weathered, hence groundwater occurrence in this formation is Gibrilla et al 2010b) very high. The granites in the basin are less fractured and weathered, hence groundwater occurrence is moderately low.…”

“…Borehole yields within the fractured zone are determined by the extent and degree of fracturing (Gibrilla et al 2010b;Buckley 1986). Transmissivity varies between 1 and 72 m 2 /day.…”

“…All these authors generally appear to attribute the groundwater hydrochemistry to rock-water interaction. Later studies by (Gibrilla et al 2010b;Adomako et al 2010) using stable isotopes of 18 O and 2 H showed an evidence of evaporated waters recharging the groundwater system in some areas; this implied that anthropogenic activities on the surface and the unsaturated zone (Bam et al 2011) may pose a serious challenge to the groundwater quality in the near future.…”