Assessment of groundwater quality using statistical techniques in high Basin of Guir (Eastern High Atlas, Morocco)

Abstract This paper reports results of a physico-chimical study of groundwater in in high Basin of Guir (Eastern High Atlas, Morocco). The water quality data was monitored at ten different wells and springs using 12 water quality parameters (Biochemical oxygen demand (DBO 5 ), chemical oxygen demand (DCO), Sulfate (SO4 2 - ), Ammonium (NH 4 + ), Nitrate (NO 3 - ), Nitrogen dioxide (NO 2 - ), chloride (Cl - ), Sodium (Na + ), Electrical conductivity(EC), pH, Turbidity, suspended matter(MES)). The Principal Component Analysis (PCA) was used to examine the data with the objective of determining the spatial variability of groundwater and to identify the sources of pollution. Results show that two factors account for almost 59% of the variance: factor 1 is that of the nitrogenous salts (NH4 + , NO 3 - and NO 2 - ) while the factor 2 is related to mineral salts (Cl - and SO42-). The typological structure of the plan analysis F1 x F2 shows four areas depending on the nature of salt pollutants. The contamination observed for the majority of stations could be related to domestic, fertilizers and geological sources of pollution.