Potentialites hydrogeologiques du synclinal de kourimat (Bassin D'essaouira, Maroc)

The synclinal basin of Kourimat, situated in the oriental part of Essaouira basin, shelters an aquiferous carbonate. This aquiferous represents the unique resource in water for the region. The study undertaken on this aquiferous has allowed us the characterize it viewpoint hydrodynamically, hydrogeologically and hydrogeochimically. The piezometric map of the system shows a senses of water flow underground of the southeast to the northwest. The hydraulic gradient varies from the upstream to the downstream. The evolution of the piezometry at one time watch of annual and seasonal fluctuations in connection with variations of precipitations. The results of chemical analyses have allowed to distinguish two aquiferious: the first is Cenomanian, the second is Turonian. Theses aquiferious were diffrenciated by there chemical facies and the origine of chemicals elements.La cuvette synclinale de Kourimat, située dans la partie orientale du bassin d'Essaouira, abrite un aquifere carbonaté constituant l'unique ressource en eau de la région. L'étude entreprise sur cet aquifere a permis de le caractériser de point de vue hydrodynamique, hydrogéologique et hydrogéochimique. La carte piézométrique du systeme montre un sens d'écoulement global du sud-est vers le nord-ouest. Le gradient hydraulique varie de l'amont vers l'aval. Les fluctuations piézométriques montrent une bonne corrélation avec les aléas climatiques. Les résultas de l'étude hydrochimique ont permis de mettre en évidence l'existence de deux nappes: la premiere dans le Cénomanien et l'autre dans le Turonien. Ces deux nappes se différencient par leurs facies chimiques et par l'origine des éléments en solution

Hydrochemical and Isotopic Study of Water Downstream of the City of Marrakech after the Installation of the Sewage Treatment Plant

The objective of this work is to gauge the impact of the installation of the treatment plant on the water quality of El Azzouzia aquifer. The aquifer of El Azzouzia is located downstream of the Haouz aquifer. The water of this area was threatened by the pollution resulting from the mushrooming houses that proliferated in the region, which culminated in the degradation of the environment. According to hydrochemical analyses, electric conductivity is high in that it varies between 400 and 3200µs/cm. There is also a decrease in the majority of chemical elements in which the rates are inferior or equal to the quality standards, except for chlorides and sodium which can reach a maximum of 2300 mg/l and 1000 mg/l respectively. Another type of study that has been conducted is the isotopic study. This kind of study aims to determine the source of the elements that still mark the waters of this area. The results show that the 18O contents range from -7.89 to -5.21‰ while the 2H contents range from -52.49 to -37.05‰ indicating that the recharge area is located on an altitude that varies between 840 and 1900m, which corresponds to the Permo-Triassic evaporite formations. The degradation of the water quality sources is either from natural pollution (i.e. from the geological contributions of the aquifer recharge basin) or is anthropogenic (i.e. from the seepage of wastewater)

Caractérisation des modes de variabilité interannuelle des pluies dans les grands bassins du Maroc (Moulouya, Sebou et Tensift) et liens avec les signaux climatiques

National audienc

Relation entre Variabilité hydrologique et fluctuations climatiques (NAO, SOI) de 3 hydrosystèmes au Maghreb (Bassins de la Soummam et du Tensift, Nappe du Haouz)

International audienc

Relation entre la variabilité climatique et les fluctuations du climat à l’échelle des grands bassins versant du Maroc (bassins Moulouya, Sebou et Tensift).

International audienceLes bassins versants, intègrent les hétérogénéités de nombreux paramètres, notamment hydrologiques, sédimentaires et climatiques. De plus, ils sont affectés par les activités anthropiques. Ce travail a pour objectif de déterminer et de caractériser la variabilité hydrologique des bassins versants sur le long terme et d’étudier les facteurs de contrôle climatique et physiographique, déterminer les liens existants entre variabilité et fluctuations climatiques. Trois régions du Maroc feront l’objectif de notre étude : le bassin de la Moulouya méditerranéen, situé au Nord Est du Maroc, le bassin du Sebou étendu au Nord-Ouest, sur l’océan Atlantique et de la mer Méditerranée et le bassin du Tensift, de contexte continental situé au centre Ouest du Maroc. Il sera proposé d’étudier la variabilité temporelle de la réponse hydrologique (changements à long terme, oscillations et fluctuations des variables hydrologiques) par l’analyse de séries de pluie SIEREM et de pluie des stations, ensuite déterminer leurs relation avec les fluctuations climatiques (représentées par des indices climatiques comme le SOI, la NAO, WMOI…) par la méthode des ondelettes continues

Evaluation of groundwater quality and agricultural use under a semi-arid environment : case of Agafay, Western Haouz, Morocco

Water resources are a priority for economic development, aiming at meeting the increasing needs of agriculture and all socio-economic sectors. Agriculture is one of the essential pillars of this development in the Haouz Plain. Under a semi-arid climate, irrigation, consuming more than 85% of available water, is inevitable for most crops. Hence, groundwater is becoming increasingly under pressure. Salinization due to poor irrigation management is one of the main causes of soil degradation. In this context, assessment of groundwater quality and risks of soil salinization was carried out in irrigated citrus orchards located in the western part of Haouz and aimed at understanding the connection between natural context, irrigation practices, and water and soil salinization. The spatial distribution of aquifer potential lines is affected by groundwater over-exploitation. Moreover, geologically, the Palaeozoic substratum rise constitutes an obstacle for underground flow, which explains the low values recorded and measured around the studied area. The groundwater quality in the study area is characterized by strong mineralization, consequently affecting the soil by secondary salinization due to the intensive use of moderate saline waters from groundwater. Using a mixture of different water origins is a practical measure to reduce the risks of degradation of the soil

Assessment of subsidence and collapse hazards using electrical resistivity tomography: case study of Ida Ouazza salt mine, Essaouira province - Morocco

info:eu-repo/semantics/publishedVersio

Carte Geologique du Maroc au 1/50 000, feuille Boumalne - Notice explicative

The Boumalne sheet cover the northern margin of the Anti-Atlas, which is made up of precambrian Saghro massif and its paleozoic cover, the western part of the Ouarzazate Basin and the southern margin of the central High Atlas. The oldest Saghro basement outcrops in the Boumalne window and is characterized by two units referable to the middle Neoproterozoic and Cryogenian (NP2-PII):i) arenaceous-pelitic metasediments with few flows and dikes of tholeitic basalts, metamorphosed and folded at a regional scale during the panafrican orogeny; ii) some intrusive calc-alkaline bodies, slightly metamorphosed (Imider: 675 Ma; Tiboulkhirine:645 Ma). This middle proterozoic is discordantly covered by thiks volcano and volcano-clastic sequences (Group of Ouarzazate) and truncated by sub-volcanic and intrusive bodies (Tiounouine and Aguensou) which can be referred to the upper Neoproterozoic or Ediacaran (NP3-PIII). The Paleozoic correspond to a reduced cambro-ordovician sequence outcropping only in the eastern part of the sheet. It indicates a bathynetry varying between intertidal and open marine. Its base is unconformable on the proterozoic basement and the Ordovician is separated from the middle Cambrian by the clastic upper cambrian/termadocian hiatus. Towards the top, the Ordovician and the upper Paleozoic are cut by the unconformity following the hercynian orogeny. The Paleozoic rapidly disappear towards the west at the so called "Imider Threshold" where the mesozoic-cenozoic sequence directly lie on the precambrian rocks of the Saghro basement. The mesozoic-cenozoic sequence is made of marine and continental sediments covering about three quarters of the map. The lower part of the sequence, Jurassic in age, is carbonatic and represents the filling of basins formed in the "Atlasic" rifting phase, while the upper part, Cretaceous to Pliocene in age, represents both the cover of the High Atlas and the filling of the Ouarzazate basin. A hiatus separates the jurassic from the cretaceous deposition , which starts in the Cemnomanian with a continental sequence. In the upper Cretaceous the sequence indicates syntectonic characters and corresponds to an alternation of continental and marine platform formations. The upper paleocene to middle eocene sediments, which unconformably lie on the middle-upper cretaceous sequence, are characterized by coastal sediments. In the upper Eocene the sediments become predominantly continental. At Present the northern sector of the Ouarzazate basin is partly overthrusted by the front of the High Atlas belt