The hydrogeochemical evaluation of groundwater resources and their suitability for agricultural and industrial uses in an arid area of Iran

Abstract

The hydrogeochemical and quality status of groundwater resources in Yazd province, the central plateau of Iran, has been investigated. The most common water type, followed by chemical facies in this study area, is Cl type (with 50.46%) and Na–Cl facies (47.71%), respectively. Besides, the most samples with industrial and agricultural uses show the Cl type and Na–Cl hydrochemical facies. The position of samples on the Gibbs and van Wirdum diagrams indicate that the water-rock interaction and dissolution of evaporites are the main controlling process of water chemistry. Distribution of samples based on Na/Cl vs. EC, Ca + Mg vs. SO4 + HCO3, and Na–Cl vs. Ca + Mg–SO4–HCO3 highlight the significant role of direct ion exchange in water chemistry change. The water quality for agricultural use is assessed based on some indices including EC, Na%, sodium absorption ratio (SAR), residual sodium carbonate (RSC), magnesium absorption ratio (MAR), permeability index (PI), Kelly's ratio (KR), and Wilcox diagram. In general, the water quality for irrigation purposes is mainly excellent to permissible. The water quality assessment for industrial purposes is performed using some indices including Langelier Saturation Index (LSI), Ryznar Stability Index (RSI), Larson-Skold Index (L-SI), Puckorious scaling index (PSI), and total hardness (TH). Based on these indices, most groundwater samples have mild to high potential to corrode the equipment and pipelines.