Assessment of irrigation water quality in Urmia plain (Iran) using different quality indices

The aim of this study is to evaluate suitability of groundwater for irrigation purposes in Urmia plain, West Azerbaijan, Iran; where agriculture activities are dependent on groundwater because of increasing drought trend in Lake Urmia. Fifty-nine water samples from groundwater were selected during dry season in ۲۰۱۸ and analyzed for water quality parameters. The present study was carried out to investigate the spatial variability of water quality indices (PI, MAR, SAR, RSC, LSI, KR, %Na) by geo-statistical methods to determine suitable areas for irrigation. Electrical conductivity (EC), pH, calcium, sodium, chloride, sulfate, potassium and TDS concentrations were in permissible limit, while %۸.۵ and %۱۷ of groundwater wells; in bicarbonate and magnesium, respectively; were higher than acceptable limit within prescribed limits as FAO (۱۹۹۴) for irrigation purpose. The calculated SAR and RSC values suggested excellent quality for irrigation. The values of PI and %Na suggest that the groundwater of study area is suitable for irrigation purpose. It shows that concentrations of MAR are lower than the permissible limits in %۱۸.۶ of wells; Whereas computed values of LSI indicate unsuitable groundwater of study area. The spatial distribution maps of groundwater quality indicated that the central of Urmia plain is the most suitable zone for irrigation purposes.

Keywords:

component: Groundwater , Water salinity , Urmia lake , Spatial distribution