Investigation of Nitrate Concentration Anomaly Source and Vulnerability of Groundwater Resources of Tabriz Plain Using AVI and GOD Methods

The great plain of Tabriz is an active practical farming, olericultural and industrial area due to the centralization of East Azerbaijan population in this area. Entrance of industrial and urban sewages as well as recycled water from the agricultural activities into the groundwater of the plain contaminates the water and soil resources of the area and makes an environmental disaster. In this study the contamination of groundwater resources of the plain with nitrate and its distribution in different parts of the plain and the effects of different sources of nitrate such as industrial and urban sewages as well as recycled water from the agricultural activities on these resources were investigated. For this purpose, 30 samples were collected from evenly distributed deep and shallow wells in October 2013 and chemically were analyzed in hydrologic lab of the University of Tabriz. Maximum and minimum nitrate concentrations in the study area were 243.7 mg/L and 0.4 mg/L which belonged to the samples collected from the west end of Tabriz city (Gharamalek region) and west end of the plain (Satloo region), respectively. Finally, groundwater vulnerability of the plain was evaluated using the AVI and GOD methods for coincidence of vulnerable places of the aquifer with high nitrate concentrations.