Private Exploitation of the North-Western Sahara Aquifer System

Abstract

We formulate a hydro-economic model of the North-Western Sahara Aquifer System (NWSAS) to assess the effects of intensive pumping on the groundwater stock and examine the subsequent consequences of aquifer depletion. This large system comprises multi-layer reservoirs with vertical exchanges, all exploited under open access properties. We first develop a theoretical model to account for relevant features of the NWSAS by introducing, in the standard Gisser-Sanchez model, a non-stationary demand and quadratic stock-dependent cost functions. In the second step, we calibrate parameters values using data from the NWSAS over 1955-2000. We finally simulate the time evolution of the aquifer system with exploitation under an open-access regime. We specifically examine time trajectories of the piezometric levels in the two reservoirs, the natural outlets, and the modification of water balances. We find that natural outlets of the two reservoirs might be totally dried before 2050.

Agriculture in the North Western Sahara Aquifer System: A miracle in the making?

“…On the contrary, however, there are also some critical reports stating the adverse impacts of intensive agriculture on depletion of the aquifer and degradation of fragile ecosystems because the brackish water and limited recharge. Chekirab et al (2022) developed a hydroeconomic model of the NWSAS using data from 1955 to 2000. They observed that the NWSAS aquifer comprises of multilayer reservoir with vertical exchanges.…”