Climate change will affect the water resources system, on global and regional levels. Over the past thirty years, the High Atlas Mountains in Morocco have experienced severe droughts, which causes a decrease in water supply that affects both agriculture and the urban water system. In this paper, we assess the impact of climate change and socio-economic activities on water supply and demand in the Ourika watershed (High Atlas of Morocco), then we evaluate the efficiency and sustainability of regional adaptation strategies for water supply management. For this, we simulate and analyze the future water situation using the statistical downscaling model (SDSM) and the water assessment and planning tool (WEAP). After the model’s calibration and validation, the precipitation, minimum (Tmin) and maximum (Tmax) temperatures, water demand and unmet water demand were projected for 2100 horizon, using different climate change scenarios. The results revealed that the model’s performance, calibration and validation were found to be satisfactory. The analysis shows that the mean precipitation will decrease by 49.25% and 34.61% by 2100, under A2 and B2 emission scenarios of the Intergovernmental Panel on Climate Change (IPCC). The projected mean Tmax and Tmin will be warmer than the baseline period, with Tmax increasing by 4.2 °C (A2) and 3.6 °C (B2), and Tmin by 3.5 °C (A2) and 2.9 °C (B2) by 2100. The results also show that water demand and the unmet water demand will increase in all scenarios, the pressure on water resources will increase, leading to water scarcity. The results reveal that, under the influence of climate change, future unmet water demand is expected to reach 64 million cubic meters (MCM) by 2100. The results demonstrate that the assessments of the proposed adaptation strategies are effective, but not sufficient to ensure water sustainability for the Ourika watershed.

Morocco is one of the regions of the world where many interesting discoveries have recently been made in the field of stygobiology, particularly concerning the cirolanid isopod fauna. One of the most interesting, variable and wide spread of these taxa is the perimediterranean stygobitic genus Typhlocirolana Racovitza, 1905, which has colonized the continental groundwater of Israel, Sicily, Spain, the Balearic Islands, Algeria and Morocco with several species. More populations have recently been found in Morocco, in some southern regions around Agadir, in High Atlas valleys near Marrakech and in the northeastern part of the country close to Oujda. The populations of these zones are not yet described and are the subject of this molecular analysis, together with other already designated species. To investigate the phylogenetic relationships and evolutionary history of the Typhlocirolana populations inhabiting the western Mediterranean basin, we analysed DNA sequences from the mitochondrial 12S and 16S rDNA genes. The molecular data were also used to infer the mechanisms driving the evolution of this thalassoid limnostygobitic cirolanid taxon, considered a good paleogeographic indicator because of its poor dispersion abilities. Vicariance because of paleogeographic events in the western Mediterranean basin played a prime evolutionary role in the Cirolanidae, as already suggested by morphological and ecological studies. Application of a molecular clock provided a time framework of the microevolutionary events occurring in Typhlocirolana populations over the last 40 myr.

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The biodiversity and the quality of subterranean waters have been comparatively studied in the Haouz plain near Marrakesh and in the Tafilalet, in south-eastern Morocco. For this purpose, physicochemical and faunistic analyses were carried out on the water of ten wells and springs located in the area of Marrakesh, and in Errachidia area respectively. In the wells of Marrakesh, the average stygobiologic diversity is relatively high in the wells located upstream the dumping from the city where the ground water presents low contents of nitrates and orthophosphates. In contrast, the wells located in the spreading zone of Marrakesh wastewaters are characterized by the scarcity or the absence of stygobitic species; in these latter wells, the water is highly polluted. It is rich in nitrates, nitrites, ammonium, and the conductivity is rather high. In the area of Errachidia the faunistic inventory gathers some ten species, some of which are living in hot springs. The subterranean water is highly mineralised. In the two studied areas, the biodiversity decreases when well water is locally polluted, and the subterranean fauna completely disappears if the degree of contamination is important. This relation between the biodiversity and water quality which had already appeared in surface water, is confirmed within the wells of Marrakech. The groundwater fauna of both two areas presents similarities in relation to their geological history, mainly the various marine cycles of marine transgressions-regressions, which were at the origin of the settlement of the ancestors of the extant species, and the Atlasic orogenesis which separated the common ancestral populations into two separated stocks, involving a different evolution of the ancestors and a resulting speciation by vicariance.

Metal sulphide tailings represent a potential risk basically for the environment and particularly for water resources, because of their natural oxidisability which leads to the production of acid/neutral mine drainage. The prospected site close to Marrakech includes zinc, lead and copper sulphide deposits. This site is located in an agricultural area where ground water is used both for irrigation and drinking. Eco-toxicological investigations have been undertaken in order to asses the tailings impact on water quality in nearby wells. These investigations include physico-chemical characterization of the groundwaters as well as faunistic population determination. As compared to standard wells, waters from the wells located downstream of the mining site, have high electrical conductivities and high major ions contents, which can reach: 755 mg l(-1) in SO4(2-), 1670 mg l(-1) in Ca2+, 528 mg l(-1) in Mg2+, 2289 mg I(-1) in Na+ and 14981 mg l(-1) in Cl-. The fauna distribution analysis carried out around the studied wells shows qualitative and quantitative differences according to the flow gradient of the groundwaters. Areas located upstream of the mine tailings site are richer in stygobite species (Type and quantity) than those located downstream or close to it. It is likely that these biological differences are due to water quality alteration induced by the mining activity.