Groundwater resources management using Hydrodynamic modelling in southeastern Moroccan oases: case of Ferkla Oasis

Abstract

The Ferkla Oasis is situated in the Rheris watershed in the southeast of Morocco, between the eastern Anti-Atlas in the south (Ougnat inlier) and the Central High Atlas in the north. This oasis is characterized by a semi-desert climate with strong continental influence, marked by low and irregular rainfall as well as high temperatures. This oasis has experienced several agricultural extensions outside the traditional oasis, resulting in overpressure on the groundwater as evidenced by the dramatic decline of its piezometric level, which has engendered an ecological and socio-economic crisis. In these critical conditions, a groundwater flow model was developed to evaluate the impact of climate change and anthropogenic activities on the hydrodynamic behavior of the aquifer. The results obtained confirmed that the region is increasingly threatened by groundwater resource scarcity. Indeed, simulations of the watershed in both a permanent and transient state were generated for the years of 1993 through 2021. These simulations have shown a piezometric level decline, as well as a deficit in the water balance, as well as a deficit in the water balance. This situation is caused by climate effects, particularly frequent droughts, and the overexploitation of the groundwater resources, especially in the agricultural extension areas outside the traditional oasis. The study demonstrates that the oasis faces a serious crisis and may further deteriorate until it disappears within a few years. Therefore, integrated, collective and participatory measures are recommended. The model provides important results that will aid in groundwater resource management in this region.

Mapping Favorable Groundwater Potential Recharge Areas Using a GIS-Based Analytical Hierarchical Process: A Case Study of Ferkla Oasis, Morocco

“…Generally, a high permeability (K = 1 to 3•10 -3 m/s) is found in sandy-gravelly alluviums, a medium permeability (10 -5 m/s < k < 5•10 -4 m/s) characterize conglomerates and fractured lacustrine limestone, and low permeability (10 -6 m/s < k< 10 -5 m/s) for lacustrine marls, compact limestone, and clays. The transmissivity of the Quaternary overburden varies between 2.5•10 -4 and 3•10 -2 m/s, whereas the thickness is known to be between 1 and 40 m (Margat et al, 1962;Messaoudi et al, 2023;Ait Said et al, 2023). From a structural and geological point of view, the Ferkla Oasis is bounded to the south by the Anti-Atlas Atlas Domain, to the east by the Rheris Plain, to the north by the Central High Atlas (Ifgh-Aghbalou N'Kerdous), and to the west by the Ghalil plain (Figure 2).…”