Nasrin fatolahzadeh attar - Urmia university Author Urmia, Iran
Keivan khalili - Assistant professor urmia university Urmia, Iran

Determination of water quality is important because of it helps to protect,restore the quality of the ground-waters,and management of groundwater that consistent with the requirements of the clean water. The most important stage of groundwater quality zoning in this method is investigation of the best interpolation method.In these regards,Geographic Information System (GIS) provides an effective tool to generate,manipulate, and organize the spatially disparate data for modeling and groundwater quality zoning.Urmia is a city in north west of Iran. A large proportion of water requirements for this city are supplied from ground water.In this research, groundwater quality assessed through sampling 104 wells in Urmia and its rural areas from years 2000-2009.The data obtained for the parameters of the SAR,PH,TH,TDS and EC in Excel software for preparing the database was stored in dbf format .The main Purpose of this study is estimating qualitative zoning of underground water resources In terms of water quality parameters in the city of urmia by using geostatistical method. This area is geographic range of 37°,6' to 38° east longitude, and 44° 20' to 45° 20' north latitude. The method of IDW(inverse distance weighting) was used in this study. The final map classified the ground quality in the study area. The results of this research show that the development of the management strategies for the aquifer system is vitally necessary.

GIS ; Interpolation ; Groundwater quality ;IDW