An Estimate of Groundwater Recharge in the Nabogo River Basin, Ghana Using Water Table Fluctuation Method and Chloride Mass Balance

摘要

The Cambrian-Precambrian fractured sandstone aquifer in the Nabogo River Basin in the Sahelian Northern Region in Ghana is one of the most important sources for fresh water supply for the local rural communities there. Recent population growth and commercial agricultural interests in this region could have an impact on this critical water resource. Groundwater recharge estimates are determined in this study using the Water Table Fluctuation Method and Chloride Mass Balance and can be applied to future sustainability studies of the regionu27s water resources. Recharge estimates of the Water Table Fluctuation Method are in a range of 10-143 mm/yr or 1-13% of annual rainfall. Chloride Mass Balance groundwater recharge estimates show an annual recharge of 37.06 mm/yr. or 4% of annual precipitation. Recharge source is determined to be from local meteoric waters using stable isotopic analysis of Oxygen (δ18O) and Deuterium (δD). The limitations, advantages and disadvantages of these methods are discussed in this study as well as the possibilities for future research.