دشت خوی در شمال غرب کشور و در شمال استان آذربایجان غربی گسترده شده است .شهر خوی مهم ترین شهر در این دشت محسوب میگردد .این منطقه جزء مناطق سرد و خشک محسوب شده و متوسط بارندگی آن ۳۴۴ میلی متر میصباشد .منابع آب سطحی منطقه عمدتأ شامل دو رودخانهصی قطور و الند می باشد .هدف از این پژوهش بررسی کمی و کیفی منابع آب زیرزمینی دشت خوی و تعیین آلودگی فلزات سنگین در مناطق مختلف دشت میصباشد .سفره های تحت فشار و نیمه تحت فشار به صورت ناپیوسته و موضعی در بخش-های غربی و مرکزی دشت و سفرهصهای آزاد را در همه نقاط مشخص شدند .جهت جریان آبصزیرزمینی با توجه به خطوط همصپتانسیل از جنوبصغرب به شمالصشرقی دشت میصباشد .به منظور بررسی کیفیت آبصزیرزمینی دشت خوی، علاوه بر جمعصآوری اطلاعات صورت گرفته، ۳۶ نمونه آبی از چاهصهای موجود در دشت نمونهصبرداری شد .پارامترهای هدایت الکتریکی و pH در محل نمونهبرداری و نیز با یونصهای اصلی) کلسیم، منیزیم، سدیم، پتاسیم، کلر، سولفات، کربنات و بیکربنات(، یونصهای فرعی) نیترات و فلوراید (و عناصز جزئی) آرسنیک، آهن و مس (در آزمایشگاه آبشناسی گروه زمینشناسی دانشگاه تبریز مورد آنالیز قرار گرفتند .ترکیب آبزیرزمینی در منطقه بیشتر از دو تیپ بیکربناته و کلروره تشکیل یافته است .به طور کلی تیپ منابع موجود در بخشهای جنوبی و شرقی کلروره است و تیپ آب در بخشصهای غرب و شمالصغربی دشت از نوع بیکربناته میصباشد .
Khoy plain is situated in the north of West Azarbaijan province, northwest on Iran. Khoy is the main city of this area. The study area has a cold and arid climate with the annual mean precipitation about 344 mm. Qhotur and Aland rivers are the main surface water resources of the area. Aim of this research is investigating the quality and quantity of groundwater resources in the Khoy plain and determination of heavy metals contamination in different places of the area. Confined and semi-confined aquifers are recognized in western and central part of the plain discontinuously and locally but unconfined aquifer is extended in the whole plain. Potential contour shows that groundwater flow direction is from southwest to northeast of plain. In order to investigate quality of groundwater resources in the study area, beside the former hydrochemical data, 36 water samples were collected from water resources. Unstable hydrochemical parameters including pH and EC were measured during sampling on site and also with major ions (Calcium, Magnesium, Sodium, Potassium, Chloride, Sulfate, Carbonate and bicarbonate), minor ions (nitrate and fluoride) and trace elements (As, Fe and Cu) were analyzed in hydrogeological laboratory of Tabriz University. Groundwater samples have two types, Ca-HCO3 water type and Na-Cl. Generally, groundwater type is Na-Cl in the south and east area and Ca-HCO3 in west and north. EC investigation in area shows that electrical conductivity increase from southwest to northeast and nast which coincided is in the direction of groundwater flow. In the EC values in east and northeast (output of groundwater) are more than the other parts of the plain, due to the discharge, evaporation of groundwater, evaporative formations and pumping water from the wells. EC values increase in the central area of plain , as a result of fine-grained and low permeability alluvium. Based on hydrochemical studies, the concentrations of sodium, chloride, arsenic and iron in groundwater of this area exceed World Health Organization (WHO) drinking water standards. The main factor of these anomalies can be related to the geological formations. According to the cluster analysis, analyzed samples were in three clusters, the first cluster includes most of samples with low to moderate EC values. The second cluster has a high electrical conductivity value and the third cluster of samples with very high EC value. Each of the clusters containing heavy metals and other parameters are divided into different subtypes. Based on factor analysis method, three main effective factors were found on hydrochemistry of the study area. First and second factors show the effect of geological formations and general groundwater trend on hydrochemistry of the area. The third factor is influence of human activities. In the first factor, chloride, sodium, potassium, arsenic, copper, iron and electrical conductivity, and in the second factor magnesium, bicarbonate, fluoride and pH are effective, while in the third factor calcium and nitrate were related together. In fact, the first and the second factors are geogenic, and the third one is anthropogenic