ORIGINAL ARTICLE Hydrogeochemical assessment of the Upper Cheliff groundwater (North West Algeria) Fadilha Touhari • Mohamed Meddi • Madjid Mehaiguene • Moumtaz Razack Received: 24 August 2013 / Accepted: 10 August 2014 Ó Springer-Verlag Berlin Heidelberg 2014 Abstract The quality of the Upper Cheliff groundwater, located in North West Algeria, has in recent years under- gone serious deterioration due to uncontrolled discharge of urban wastewaters, intensive use of chemical fertilizers in agriculture as well as to overexploitation. This study aims at analyzing the flow pattern of the Upper Cheliff groundwater, determining its current hydrochemical status and understanding the mineralization processes involved in its chemical quality. Two piezometric and sampling cam- paigns were carried out in 2008 in high water (April) and low water (October) periods. The major chemical ions (Ca 2? , Mg 2? , Na ? ,K ? , Cl - , HCO 3 - , NO 3 - , SO 4 2- ) were analyzed in all samples. The piezometric data were mapped and allowed to analyze the groundwater flow conditions, in particular at the boundaries of the aquifer. The interpreta- tion of hydrochemical data was made using various methods (Piper diagram, Stabler classification, base exchanges index, bi-elements scatter diagrams, saturation indices, mapping and multivariate principal component analysis). The results provide a better understanding of this aquifer hydrogeology and hydrochemistry. Several hydro- chemical types (chloride-calcium, chloride-sodium and bicarbonate-calcium) characterize the groundwater. Min- eralization processes and the origin of salinity are deter- mined by the lithology of the aquifer (dissolution, base exchanges), and by climatic (evaporation) and anthropo- genic factors (agricultural and urban wastes). The groundwater in the Upper Cheliff is currently of poor quality. This status is worrying, as this groundwater is an important natural resource for the socio-economic devel- opment of this region. Urgent measures must be taken to preserve this resource. Keywords Upper Cheliff  Groundwater flow  Hydrochemistry  Mineralization  Principal components analysis  Algeria Introduction Groundwater is a significant and crucial resource in many countries, and it commonly plays a key role as a water supply both for drinking and irrigation. In the last decades, water demand has dramatically increased, especially in developing countries, driven by population growth, improvements in living standards, development of industry, agriculture and urbanization (World Water Assessment Programme 2009; Llamas and Martı ´nez-Santos 2005). This has led to increasing pressures on groundwater resources. Excessive abstractions of groundwater over the past dec- ades to meet these demands have resulted in serious trou- bles: water table decline, groundwater quality degradation and damage to ecosystems. It is evident that groundwater quality issue is as important as groundwater quantity for satisfying water needs (Karanth 1997; World Water Assessment Programme 2012; United Nations Environ- ment Programme 2010). Poor groundwater quality may have a number of economic and social impacts (ecosystems degradation, health problems, treatment costs, impacts on agriculture, industry, tourism). This issue is thus becoming a global concern of increasing significance. Groundwater quality degradation risks are many and diverse. Untreated F. Touhari  M. Meddi  M. Mehaiguene Ecole Nationale Supe ´rieure d’Hydraulique, Blida, Alge ´rie F. Touhari  M. Razack (&) Department of Hydrogeology UMR 7285, University of Poitiers, 5 Rue Albert Turpain, B8 TSA 51106, 86073 Poitiers Cedex 9, France e-mail: moumtaz.razack@univ-poitiers.fr 123 Environ Earth Sci DOI 10.1007/s12665-014-3598-6