Vulnerability assessment of Tubular Middle Atlas water aquifer, Causse of El Hajeb/Morocco
Creators: name: Muzirafuti, Anselme
name: Boualoul, Mustapha
name: Randazzo, Giovanni
name: Allaoui, Abdelhamid
name: Lanza, Stefania
name: El-Ouardi, Hmidou
name: Habibi, Mohamed
name: Ouhaddach, Hafida
Publisher: name: Zenodo
Year: 2018
Subjects: Vulnerabulity
Causse of El Hajeb
Karst aquifer
Remote sensing
Applied geophysics

description: Tabular Middle Atlas of El Hajeb holds the most important water aquifer which provides water for the people living in the Cities of El Hajeb, Meknes and Fez. This aquifer is located in Liassic dolomite and limestone. These carbonate rocks constitute a karst environment which is facing more problems - such water pollution, water table level fluctuation, sinkholes collapse, surface erosion, increase water turbidity and water spring drying up - due the ongoing climate change and increasing population growth, and hence become more vulnerable environment. In order to identify the level of vulnerability across this region, we used PaPRIKA method, [1] as a tools to estimate the origin of this vulnerability. Adopting a multidisciplinary methodology approach integrating remote sensing, applied geophysics and on-ground-based lithology and structural measurements, we analyzed four criteria (Protection, reservoir, Infiltration and karstification) which involved in the application of PaPRIKA method. Satellite images and geophysical data were processed and analyzed in the aim of getting information on soil parent materials, on characteristics (lithology, fractures, and layer thickness) and on the functioning of epikarst zone. We also introduced geochemical and water table analysis of karst reservoir. Landcover mapping revealed that in the Causse of El Hajeb 53 % carbonate rocks, 15 % soil in basalts and clays, 30 % vegetative cover ( forest, farming areas and other vegetation), 0.9 % artificial construction and water surface for the rest. On these carbonate rocks fractures mapping on satellite images using automatic and manual extraction revealed two main faults systems in NE-SW and NW-SE involved in surface water infiltration and groundwater drainage respectively, this has been validated by on ground fracture measurements in different location of karst aquifers. The location of different karst landforms (sinkholes, avens, water spring, poljes and lakes) were also identified and some of them are believed to the origin of chemical and turbidity revealed geochemical analysis, [2] on water springs (Ain Ribaa, Ain Bittit, Ain Maarouf,..). Electrical resistivity tomography conducted along some sinkholes and boreholes data provided geological information on the reservoir (in Liassic dolomite and limestone) and its protection (Quaternary clays and basalts), the substratum is composed by schists and quartzites of Palezoic. Hydrogeological model of this region showed aquifer recharge area in high altitude with precipitation and snow fall as input, on the hand the aquifer discharge area is located at the contact of TMA and the Saiss basin with numerous water springs providing drink water to the population living in this region. All the results were introduced in geographic information system to produce maps of vulnerability on which agriculture and non-protected areas were identified as more vulnerable regions.