[1]. Iran Water Resources Management Co. Study of state of water resources of the country. 2016. [Persian].
[2]. Adepelumi A, Ako B, Ajayi T, Afolabi O, Omotoso E. Zelineation of saltwater intrusion into the freshwater aquiger of Lekki Peninsula, Lagos, Nigeria. Environmental Geology. 2009; 56 (5):927-933.
[3]. Anayah FM, Almasri M.N. Trends and occurrences of nitrate in the groundwater of the West Bank, Palestine. Applied Geography. 2009; 29 (4):588-601.
[4]. Camargo J.A, Alonso A. Ecological and toxicological effects of inorganic nitrogen pollution in aquatic ecosystems: a global assessment. Environ. Int. 2006; 32:831–849.
[5]. De Paz JM, Ramos C. Simulation of nitrate leaching for different nitrogen fertilization rates in a region of Valencia (Spain) using a GIS-GLEAMS system. Agr Ecosyst Environ. 2004; 103:1.59–73.
[6]. González Vázquez JC, Grande JA, Barragan FJ, Ocaña JA, De La Torre ML. Nitrate accumulation and other components of the groundwater in relation to cropping system in an aquifer in southwestern Spain. Water Resour Manag. 2005; 19 (1):1–22.
[7]. Li JS, Li B, Rao MJ. Spatial and temporal distributions of nitrogen and crop yield as affected by nonuniformity of sprinkler fertigation. Agr Water Manag. 2005; 76(3):160–180.
[8]. Goulding K. Nitrate leaching from arable and horticultural land. Soil Use and Management. 2000; 16: 145-151.
[9]. Wakida F, Lerner DN. Non-agricultural sources of groundwater nitrate: a review and case study. Water Research. 2005; 39:3–16.
[10]. Wassenaar L. Evaluation of the origin and fate of nitrate in the Abbotsford Aquifer using the isotopes of N and O in NO3. Appl Geochem. 1995; 10:391–405.
[11]. EPA. Hydrogeological assessment (groundwater quality) guideline. EPA Victoria, Publication 888, ISBN 0730676587, Australia; 2006.
[12]. Moratalla A, Gómez-Alday J. J, De las Heras J, Sanz, D, Castaño S. Nitrate in the Water-Supply Wells in the Mancha Oriental Hydrogeological System (SE Spain). Water Resources Management. 2009; 23:1621–1640.
[13]. WHO. World Health Organization, Guidelines for drinking-water quality. second addendum. Vol. 1, Recommendations. 3th edition. ISBN 978 92 4 154760; 2008.
[14]. Freeze R.A, Cherry J.A. Ground Water. Prentice Hall, Englewood Cliffs, NJ; 1979.
[15]. Kenney D. R. The origin of groundwater nitrate; 1989.
[16]. Clawges RM, Vowinkel EF. Variables indicating nitrate contamination in bedrock aquifers, Newark Basin, New Jersey. Water Resour Bull. 1996; 32 (5):1055–1066.
[17]. Kehew AE, Straw WT, Steinmann WK, Barrese PG, Passarella G, Peng W. Ground-water quality and flow in a shallow glaciofluvial aquifer impacted by agricultural contamination. Ground Water. 1996; 34 (3):491–500.
[18]. Pawar N. J, Shaikh I,j. Nitrate pollution of groundwater from shallow basaltic aquifer. Deccan Trap Hydrologic Province. India; 1995.
[19]. Nadiri A, Asgharimoghadam A, Tsai FTC, Fijani E. Hydrogeochemical analysis for Tasuj plain aquifer, Iran. Journal of earth system science. 2013; 122(4): 1091-1105.
[20]. Nadiri A, Ruzrakh J, Asgharimoghadam A. Hydrogeochemical and hydrogeological study of Harzandat plain aquifer using multivariate statistical methods and graphical methods. Journal of Iran Water Research. 2016; 23(10):111-122. [Persian].
[21]. Mahmudi M, Nadiri A, Asgharimoghadam A, Pourakbar M, Moradiyan A. Investigation of Shiramin water resources Using Multivariate Statistical Methods. 2016; 23(3): 289-302. [Persian].
[22]. Qian J, Wang L, Liu Y, Wu B, Wang X. Distribution of nitrate and its implication for the contaminant source in groundwater of Huaibei Plain, Anhui Province. 2014; Geosciences Journal. DOI 10.1007/s12303-014-0051-5
[23]. Durov S. Natural waters and graphic representation of their composition. Dokl Akad Nauk SSSR; 1948.
[24]. Oudouris K, Panagopoulos A, Koumantakis J. Multivariate statistical analysis in the assessment of hydrochemistry of the Northern Korinthia prefecture alluvial aquifer system (Peloponnese, Greece). Natural Resources Research. 2000; 9 (2)135-146.
[25]. Chen K, Jiao J.J, Huang J, Huang R. Multivariate statistical evaluation of trace elements in groundwater in a coastal area in Shenzhen, China. Environmental Pollution. 2007; 147: 771-780.
[26]. Zhang C. Using multivariate analyses and GIS to identify pollutants and their spatial patterns in urben soils in Galway, Ireland. Environmental Pollution. 2006; 142:501-511.
[27]. Mudge S, Duce C. Identifying the source, transport path and sinks of sewage derived organic matter. Environmental Pollution.2005; 136:209-220.
[28]. Mahab Ghodss Consulting Engineers Co. Tehran-Karaj Water Resources Report; 2010. [Persian]
[29]. RayAb Consulting Engineers Co. Karaj Water Supply Project (Groundwater Quality Report, Geological Report); 2015. [Persian]
[30]. Guler C, Thyne G.D, McCray J.E,Turner K.A. Evaluation of graphical and multivariate statistical methods for classification of water chemistry data. Hydogeol. J. 2002; 10 (4)455-474.
[31]. Farshadfar A. Multivariate statistical principles and methods. Razi university of Kermanshah. 2005. [Persian]
[32]. Davis J.C. Statistics and Data Analysis in Geology. John Wiley and Sons (WIE); 2002.
[33]. Tabachnick B.G, Fidell L.S. Using multivariate statistics; 2001.
[34]. Love D, Hallbauer D, Amos A, Hranova R. Factor analysis as a tool in groundwater quality management: two southern Africa case studies. Physics and Chemistry of the Earth. Parts A/B/C. 2004; 29(15):1135-1143.
[35]. Vega M, Pardo R, Barrado E, Deban L. Assessment of seasonal and polluting effects on the quality of river water by exploratory data analysis. Water research. 1998;32 (12):3581-3592.
[36]. Davis J.C. Statistical and data analysis in geology. J. Wiley; 1986.
[37]. Eekhout I, R. M. de Boer, et al. Missing data: a systematic review of how they are reported and handled. Epidemiology. 2012; 23(5)729-732.
[38]. Kaiser H.F. The varimax criterion for analytic rotation in factor analysis. Psychometrika. 1958; 23(3):187-200.
[39]. McNeil V.H, Cox M.E, Preda, M. Assessement of chemical water types and their spatial variation using multi- stage cluster analysis, Queensland, Australia. J. Hydrol. 2005; 310 (1):181-200.
)