Modelling groundwater recharge in an alluvial aquifer of Somaliland with the groundwater flow model YAGmod

Abstract

Since the 1970’s the Ged Deeble (GD) basin is exploited to supply water to the town of Hargeisa (Somaliland, East Africa, 350,000 inhabitants). The goal of this work is to improve the comprehension of the recharge mechanisms, by the simulation of groundwater flow, in order to assess the sustainability of present-day and future exploitation schemes that aim to satisfy the water demand of the city. For this goal, the exploration activities performed in the past were used to reconstruct the geological framework, the basin shape and the mechanisms of recharge and to define the conceptual model. The mathematical model YAGMod, that simulates groundwater steady flow in presence of head-dependent sources and boundary conditions, was applied to quantify the terms of the groundwater balance. Different management scenarios, accompanied by a sensitivity analysis, have been examined to verify if the future water demand of the city could be satisfied and to provide some indications about the land use planning and the management of water resources.

Keywords

• water resources, groundwater, arid regions, aquifer recharge, mathematical modelling