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The coastal aquifer of the Essaouira syncline (Morocco) was studied to identify the main processes at the origin of the salinization of groundwater. In fact, a multicriteria analysis approach on hydrochemical data and physicochemical parameters of the Plio-Quaternary aquifer was used to understand their spatiotemporal variation and their origins. Currently, integrated water resources management has become paramount to both local, regional, national and international. This management is favored by extreme hydrological events (droughts or oods) which can have direct in uences on human, economic and political aspects. Appropriate management of a resource requires its evaluation. The statistical study by Kohonen's self-organized classi cation (SOM) of hydrochemical data for the years 1995 and 2009 is used to process 47 samples distributed over the entire study area; it showed an evolution of the values of the parameters. Physico-chemical as a function of time and space with an increase in the values of the parameters, from the center of the study area towards the southwest. aquifer, the stresses applied to the aquifer (pumping, etc.) and the ow of fresh water and salty exchanging with the surrounding environment (Karroum etal., 2017). This situation is all the more critical as the groundwater in this study area (Essaouira coastal area) constitutes the only water resources available to local populations (Ouzerbane et al. 2014 ;Bahir et al. 2019). This study will take place in the context of regional planning. It will make it possible to prepare, con rm or supplement the orientations and choices necessary for a harmonious development of the region taking into account, as far as possible, all the needs and the corresponding constraints. Geographical And Geological LocationThe Essaouira basin is a coastal area located in the center-west of Morocco. It belongs to the Moroccan Atlantic margin and covers approximately an area of 20,000 km² of the eastern Mesozoic passive margin of the central Atlantic Ocean. The basin is limited to the north by the Tensiftriver, to the south by the western High Atlas, to the east by the plains of Imi-N-Tanoute and Chichaoua and to the west by the Atlantic Ocean. It is a plateau, slightly raised to the South and to the North, gently sloping down towards the Atlantic Ocean then suddenly lowering to give rise to the coastal zone with dune relief.The study area known as the synclinal Essaouira is part of the coastal area of the basin. It is bounded to the north by Qsob river, to the south by Tidziriver, to the east by the reliefs of Haha North and by the diapir of Tidzi and to the west by the Atlantic Ocean. It is not very rugged and is characterized by a relief of low hills with altitudes between 0 and 800 meters, modeled by a low density hydrographic network which ows into the Atlantic Ocean (Fig. 1).Geologically, the formations outcropping in the synclinal zone of Essaouira are generally Quaternary and Plio-Quaternary in age (Fig. 2). Going from the South to the North of the study area, th...

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Ecological niche modelling provides a useful tool to measure niche properties such as niche breadth, niche overlap and niche conservatism among genetic lineages, with relevant implications for conservation. The Mediterranean pond turtle Mauremys leprosa occurs on both sides of the Strait of Gibraltar over most Iberia and the Maghreb Region of north-western Africa, where it shows a complex genetic structure as the result of Pleistocene climatic oscillations and the particular geographical features of this region. We analyzed the overlap of the climate niche of genetic lineages and sublineages of Mauremys leprosa, based on confirmed records across the known geographical range of the species. We also compared the accuracy of environmental niche models obtained by splitting the two lineages into subunits and lumping across lineages. Results revealed an overall niche overlap between the two main lineages and among most sublineages, indicating no relationship between genetic variation and niche divergence. Likewise, the environmental niche modelling revealed an extensive geographical overlap of climatic suitability between the two lineages. However, some ecological differentiation occurs for some sublineage pairs, in particular involving a sublineage whose occurrence corresponds to a particular morphotype – the Sahara blue-eyed pond turtle – which occupies very isolated habitats along the Draa basin in Morocco. These populations are currently threatened by fragmentation of habitats, drought and water salinization. This study will help assessing more effectively the impacts of ongoing climate change on Mauremys leprosa that along with local human activities are likely to increase in the southernmost limit of its distribution.