Assessing The Impact Of Climate Change On Groundwater Resources For Sustainable Access To Potable Water In The Gambia

Sustainable Access to potable water remains a major challenge in the world due to the growing scarcity of freshwater resources.Groundwater is the main source of freshwater for drinking water in sub-Saharan Africa.Therefore,investigating factors that influence the availability of groundwater is highly relevant and can contribute to improved water resources management.The Gambia has experienced water shortage and extensive drop in the groundwater levels for many years,especially in Brikama city,yet the relationship between the groundwater level and factors explaining its drop has not been studied.In this study,we examined the effect of the variation of climate variables and the attenuation of groundwater levels in the Gambia,with particular focus on Brikama.Climate data of Yundum rainfall station and groundwater level data of 10observation wells in the West Coast Region were used for the study.Trend analysis was performed to study the pattern of variation of climate variables.Multiple Linear Regression(MLR)model was employed to establish the relationship between climate variables and the groundwater levels.Also,Autoregressive Integrated Moving Average(ARIMA)model was used to forecast the groundwater levels for three years ahead.The findings of the study show an increasing trend for rainfall and temperature,however,a decreasing trend for evaporation.The groundwater level in the study area was affected by climate variables,and rainfall is the main contributor to the water table fluctuation.The relationship between climate variables and the groundwater level is highly significant with P-Value of 1.68e-06(P<0.001)and a multiple R~2 of 48%representing the variation explained by climate variables.The groundwater level of the study site shows a decreasing trend for the projected three years(from 2019 to 2021).This study shows that climate change is a concern in the Gambia,and therefore,requires further research.It also provides evidence that there are many opportunities to intervene and improve water resources management at both environmental and governmental levels.Hence,this study could contribute to the understanding of climate change phenomena in the Gambia and have an impact on reducing climate change challenges on groundwater resources in Brikama.Moreover,the modeling results indicated that MLR and ARIMA model used in this study are able to predict groundwater levels with reasonable accuracy.