University of Tehran Press Journal of Ecohydrology 2423-6098 4 1 2017 03 21 Evaluation of Nitrate Pollution in Groundwater Resources of Ardabil Aquifer using Geographical Information System Evaluation of Nitrate Pollution in Groundwater Resources of Ardabil Aquifer using Geographical Information System 215 224 60904 10.22059/ije.2017.60904 FA Shahab Moradi Msc Student, Department of Geology, Urmia University, Urmia, Iran Hossein Pirkarrati Department of Geology, Urmia University, Urmia, Iran Farrokh Asadzadeh Department of Soil Science, Urmia University, Urmia, Iran Ali Aryanfar Zharf Azaran Sadr Consulting And Engineering Company, Urmia, Iran Journal Article 2016 11 18 Groundwater is one of the most important resources of water supply for various uses in many regions all over the globe including Iran. Different contaminants severely affect these resources and might render groundwater unsuitable for consumption. Groundwater contamination by nitrate is a well known globally growing problem due to the population growth and increase of demand for food supplies. This study was conducted to evaluate the nitrate concentration in water resources of Ardabil aquifer using Geographical Information System. Water samples were collected from 63 wells in Ardabil aquifer during the September 2014 and analyzed for nitrate concentration. The average nitrate concentration from the wells was 39.18 mgl^-1. Based on the variography analysis, nitrate concentration showed a good spatial structure which may lead to the high performance of the ordinary kriging (R²=0.508) in predicting the groundwater nitrate spatial pattern. Nitrate concentration was very high at the western parts of the aquifer where the Ardabil city and its agricultural lands is located. These results clearly indicates that the anthropogenic sources from human activities and agricultural development are the main reasons of the nitrate pollution in this part of the aquifer.   <strong> </strong>           Groundwater is one of the most important resources of water supply for various uses in many regions all over the globe including Iran. Different contaminants severely affect these resources and might render groundwater unsuitable for consumption. Groundwater contamination by nitrate is a well known globally growing problem due to the population growth and increase of demand for food supplies. This study was conducted to evaluate the nitrate concentration in water resources of Ardabil aquifer using Geographical Information System. Water samples were collected from 63 wells in Ardabil aquifer during the September 2014 and analyzed for nitrate concentration. The average nitrate concentration from the wells was 39.18 mgl^-1. Based on the variography analysis, nitrate concentration showed a good spatial structure which may lead to the high performance of the ordinary kriging (R²=0.508) in predicting the groundwater nitrate spatial pattern. Nitrate concentration was very high at the western parts of the aquifer where the Ardabil city and its agricultural lands is located. These results clearly indicates that the anthropogenic sources from human activities and agricultural development are the main reasons of the nitrate pollution in this part of the aquifer.   <strong> </strong>           https://ije.ut.ac.ir/article_60904_f4c3187cd46c346f22b4d0aaa1e74c18.pdf