Etude hydrogeologique et geographique des sources de ribaa - bittit (maroc)
Institution:
Toulouse 2Disciplines:
Directors:
Abstract EN:
Our research is about the hydrogeological study of the region of the ribaa-bittit sources. These sources are situated between the karstic plateaus of moyen atlas and the sais plain. They are fed by these plateaus. To understand the hydrogeological behaviour of these sources we are going to study in the first part of our worck the stable data of this hydrogeological unit of el hajeb-ifrane, that is its lithostratigraphy, its geomorphology, its hydrographical net work. This unit is constituated by carbonated rocks with argillaceous and marly layers. The consequence of which is superposition of underg round aquifers. In the second part, we underline the essential caracteristics of the climate of the unit of el hajeb-ifrane with a special interest for the analysis of the precipitations given that the latter represent in this area the cause of the through-flowing. It appears that the number of rainy days is important but also that the rains is weak. In the third part we study the hydrogeological structure of the ribaa-bittit based on the analysis of the hydrograms of the most important sources. Even if sources are probably fed by the same area differences of hydrogeological behaviour are noticed between the various ribaa-bittit sources under consideration. Folloing these three essential parts quite necessary for the understanding of the hydrogeological behaviour of the ribaa-bittit sources a last chapitre will give more details about both uses of these waters of this unit which are the rupplying in drinking water of the meknes city and the irrigation of sais plain.
Abstract FR:
Notre recherche est consacree a l'etude hydrogeologique du perimetre des sources de ribaa-bittit. Ces sources se situent dans le piedmont des causses du moyen atlas. Ces sources sont alimentees par ces derniers. Pour comprendre le comportement hydrogeologique de ces sources nous etudions, dans la premiere partie de ce travail, les donnees stables de l'unite hydrogeologique d'el hajeb-ifrane; c'est a dire sa lithostatigraphie; sa geomorphologie; son reseau hydrographique. . . Cette unite est constituee de roches carbonatees comportant des lits argileux et argilo-marneux, ce qui implique un compartimentage des reservoirs souterrains. Dans la deuxieme partie, nous degageons les caracteristiques essentielles du climat de l'unite d'el hajeb-ifrane en portant un interet tout particulier a l'analyse des precipitations - etant donne que ces dernieres constituent dans cette region le moteur de l'ecou- lement souterrain. Il apparait que le nombre de jours pluvieux est important mais aussi que l'intensite des precipitations est genera lement faible. Dans la troisieme partie, nous etudions la structure hydrogeologique du perimetre de ribaa-bittit, a partir de l'analyse des hydrogrammes des sources les plus importantes. Malgre une origine d'alimentation probablement commune, il existe des differences de comportement hydrogeologique entre les diverse sources de ribaa-bittit conside- rees. Faisant suite a ces trois essentielles parties, un chapitre detaille les deux utilisations des eaux de ce perimetre: l'alimen- tation en eau potable de la ville de meknes et l'irrigation d'une partie de la plaine de sais.