Étude de la qualité bactériologique et physico-chimique des eaux de certains puits et sources par l’utilisation d’une analyse en composantes principales (ACP): Une étude de cas de la région de Meknès (MAROC)

The present study aims to investigate the impact of anthropogenic factors on the quality of groundwater in some wells and springs in the region of Meknes, used for the various purpose by the local population. This work was conducted for a duration of 6 months by monthly withdrawal from February to July 2013. The main physico-chemical and biological components of water quality have been measured and a principal component analysis (PCA) was performed based on the average values ​​of each parameter, it was able to reveal the existence of a relatively strong spatial variation of these descriptors, making it appear four groups of very well differentiated and unequal stations: the first two groups together five wells and two springs provide a good quality water or slightly polluted and the last two which contain the other wells where the water is very polluted.La présente étude a pour objectif d’étudier l’impact des facteurs anthropiques sur la qualité des eaux souterraines de certains puits et sources de la région de Meknès, utilisées à différents usage par la population locale. Ce travail a été réalisé pendant une durée de 6 mois, par des prélèvements mensuels de Février à juillet 2013. Les principales composantes physico-chimiques et bactériologiques de la qualité de l’eau ont donc été mesurées puis une analyse en composantes principales (ACP) a été réalisée à partir des valeurs moyennes de chaque paramètre ; on a pu révéler ainsi l’existence d’une variation spatiale relativement marquée de ces descripteurs, faisant apparaître quatre groupes de stations très inégaux et bien différenciés : les deux premiers groupes rassemblent 5 puits et les deux sources fournissent une eau de bonne qualité ou légèrement polluée et les deux derniers qui contiennent les autres puits dont l’eau est très polluée

Impacts of Anthropogenic Factors on the Groundwater Ecosystem of Fezouata in South-East of Morocco

The depletion of aquifer systems in arid and semiarid regions worldwide is causing acute water scarcity and quality degradation, and leading to extensive ecosystem damages. Groundwater is exposed to a variety of anthropogenic water pollution, such as raw wastewater disposal in the Draa Wadi and the use of septic tanks. In this respect, a study performed in some wells of Fezouata (South-east of Morocco) aimed at both discovering the main components of the aquatic subterranean fauna unknown up to now in this area, and the potential relationships between this fauna and the water quality The principal physico-chemical characteristics of water were measured between November 2019 to March 2021 for 15 wells, which were selected considering their position with respect to the pollution sources known in surface. The Fezouata groundwater is distinguished by its high salinity with an increasing gradient from upstream to downstream. The aquatic fauna in the 15 wells showed 12 stygofauna species. In the protected wells which are situated far from the pollution sources, the fauna is dominated by Cirolanidae, Hydrobiidae, Metacrangonctydae, Stenasellidae, and Thermosbaenacea. On the other hand, in the less protected well, close to the pollution sources, the fauna is made of epigean species, such as insect’s larva, mainly Culicidae and Chironomidae. The analysis of the water quality and the subterranean biodiversity shows that the latter decreases with increasing groundwater pollution. It seems that the impact of the acute pollution affected the stygocenose even by reducing drastically the biodiversity