Groundwater Response to Precipitation Variations and Increased Abstraction Rates in the Nasia Sub-catchment, Ghana

Abstract:

There is growing concern about the sustainable use of groundwater owing to changing climatic patterns and human activities. In this study, a calibrated transient groundwater flow model for the semiarid Nasia sub-catchment of the White Volta basin in Northern Ghana is used to assess the impacts of precipitation variations and increased abstraction rates on groundwater for the period 2012-2050. The climate forcing for the future projections is derived from bias-corrected output from multiple Coupled Model Intercomparison Project phase 5 (CMIP5) climate models. The spatial and temporal variations in groundwater recharge over the calibration period are presented in this study. Details of the hydraulic properties of the aquifer system, the transient recharge and the responses of the system to the scenarios of changing recharge and increasing abstraction rates are also presented. The model provides initial basis for assessing the impacts of climate change/variability on groundwater resources fortunes in parts of the White Volta basin.