Assessment of physico-chemical quality of groundwaterof the Jurassic aquifers inhigh basin of Ziz (Central High Atlas,Morocco) [Evaluation de la qualité physico-chimique des eaux souterraines des nappes du Jurassique du haut assine Ziz (Haut Atlas central,Maroc)]

The aim of this study is to evaluate the physical and chemical quality of groundwater in the high basin of zizand identify the sources of pollution in order to map the quality of the jurassic groundwater. twenty water points were sampled during march 2014. seven chemical elements were analyzed by ion chromatography: chloride,nitrate,sulphate,sodium,potassium,calcium and magnesium. thematic maps were developped using geographic information system (sig) for studying andcomparing the spatial distribution of the results. the groundwater flow direction is from north to south in the eastern and from west to east in the western part of the basin. the water temperature varied between 15.1°c and 49 °c. the ph is close to neutrality,it varies between 6.65 and 7.86. analysis of the overall quality of water reveals that 35% of checked points are showing good quality,60% are the medium quality,and 5% are very bad quality. these waters belong to three chemical facies:chlorinated- sulfated,calcic and magnesiumfacies,a calcium andmagnesium and bicarbonate facies and a chlorinated sodic and potassium facies.the degradation of water quality in the jurassique aquifer of the high basin of ziz could have geological and anthropogenic origins.