Groundwater quality assessment using the Groundwater Quality Index and GIS in Joghatay plain, NE Iran

Water quality assessment and identification of contaminants and contaminated area where groundwater is used for drinking is very important. The present study aimed at evaluation of the groundwater quality of Joghatay plain using GQI as an indicator of groundwater quality. GQI is a suitable tool to synthesize different available quality data into easily understood format. For this reason the concentration of anions and cations in water including Na, K, Mg, Ca, SO4 -2, Cl- and TDS were analyzed. Based on the measured parameters the groundwater quality distribution map of Joghatay was provided and the groundwater quality index (GQI) was determined by GIS. GQI index value in the study area changes between 81.3 to 88.1 and it is in the acceptable range. GQI index assessment reveals that according to the distance and passing through the different formations the water quality in the northern parts of Joghaty plain is lower.