Quantifying Groundwater Sustainable Yield and Abstraction Cost in Africa

Groundwater sustainable yield (availability) and abstraction cost (accessibility) are two suitable indicators for assessing groundwater sustainability, but have not yet been quantified across Africa. In this study, we quantified the long-term average (LTA) spatial distribution of groundwater sustainable yield (for the period 1984 – 2013), the abstraction gross power, and energy demand. The groundwater sustainable yield is calculated as a function of groundwater recharge, environmental flow, and sectoral water use. The two formers are simulated by the Community Land Model version 5 (CLM5) [1], while the latter is obtained from the literature [2]. Moreover, the groundwater abstraction power and energy demand are calculated based on available groundwater table depth [3] and aquifer productivity [4] maps. We found that the African continent has the potential of 43.27 and 209.71 [km3 year-1] annual sustainable yield under conservative and optimum scenarios, respectively. Moreover, on average 2.086 kW gross power and 0.146 kWh/m3 energy demand are required for groundwater abstraction across the whole continent. This study provides a first model-based estimation of groundwater availability and accessibility across Africa that can inspire further moving toward more sustainable pathways of groundwater use in Africa.