Présentations Colloques

Oral Presentation
7.06
Session 7.06: Groundwater protection and governance: examples of groundwater protection models, and the role of the private sector
Mohamed Sinan
Characterization of vulnerability to pollution and protection of drinking water abstraction of karst aquifers.
Karst aquifers are known to be very vulnerable to pollution, as well as wells whose water originates their. There protection against pollution requires at first to characterize the degree of vulnerability to pollution of the aquifer that supplies them.**Several methods of characterizing the vulnerability to pollution of karst aquifers are mentioned in international literature.**The objective of this research is to characterize the vulnerability to pollution of the northwest part of the Middle Atlas, in Morocco (zone El Hajeb). Its area is about 500 km2.**Because of the hydrogeological context and available data, the RISKE 2 method was chosen and applied to characterize the spatial variation of the vulnerability to pollution of the El Hajeb aquifer.**The results indicate that the aquifer has a generally medium to high vulnerability to pollution. The areas of very high vulnerability are located in the recharge zones and at the outcrops of limestone formations to the NE of the study area. **Indeed, high concentrations of nitrate (exceeding the norms acceptable for drinking water) have been identified in the northern part of the groundwater which is used for agriculture purposes. Concerning the south part, the groundwater is considered to be good quality.**Protection perimeters of two wells have been delimited, referring to the vulnerability of the pollution map and the piezometric map. Within these areas, appropriate constraints will be imposed on potentially polluting activities.**Finally, we have characterized the quality of groundwater in the study area, based on studies and analysises of various wells undertaken by the ABH Sebou and ONEE Water Branch. This part highlights the development of agricultural pollution in the region.**
Morocco