• Hydrogeochemical characteristics and water quality of Aji-Chay river, eastern catchment of Lake Urmia, Iran

• # Fulltext

https://www.ias.ac.in/article/fulltext/jess/129/0199

• # Keywords

Hydrogeochemical processes; water–rock interactions; surface water; K-means clustering; Lake Urmia; Aji-Chay river.

• # Abstract

The Aji-Chay river is the most important river discharging into endangered Lake Urmia in NW of Iran. The present study investigates the hydrogeochemical characteristics and origin of dissolved ions in the Aji-Chay river and some of its tributaries passing through Tabriz plain which is located at the east side of Lake Urmia. For this purpose, 317 water samples were collected during 9 years (2005–2014) from four stations and clustered to nine groups using K-means algorithm. Major cations and anions were considered to distinguish the hydrogeochemical evolution of water. The Piper, Langelier–Ludwig and Stiff diagrams classified water samples into predominant Na–Cl endmember and Ca–HCO$_{3}$ only in the upstream zone. With respect to Gibbs diagrams, mineral saturation indices and geology of the area, water chemistry of the Aji-Chay river reflects that water–rock chemical interactions including dissolution/precipitation of carbonate and sulfate minerals known as dedolomitization and dissolution of evaporitic salts along the flow path are the dominant factors controlling the water chemistry; furthermore, evaporation, silicate weathering, and ion exchange reactions change the chemistry of water to some extent. Overall, water quality is evaluated as poor. Furthermore, intense halite dissolution increases Na concentration in water which in turn reduces its suitability for irrigation purposes.

$\bf{Highlights}$

$\bullet$Hydrogeochemical characteristics of main branches of Aji-Chay river are examined through a long-term (9 years) sampling program; then, K-means algorithm is used to cluster the data into 9 groups

$\bullet$Mineral saturation indices based on the concentration of ionic components in the water were calculated using PHREEQC software at the same thermodynamic conditions of gathered samples

$\bullet$Several Indices and standard diagrams are utilized to delineate hydrochemical processes that dominate surface water and assess the influence of possible water-rock interactions on water chemistry

$\bullet$Dissolution/precipitation of carbonate and NaCl-bearing lithological units substantially influence the quality of water

$\bullet$The suitability of water is characterized as “poor” for irrigation purposes because of high Na concentration and salinity except in the upstream where lithology has not reduced the water quality

• # Author Affiliations

1. Department of Mining and Metallurgical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran.

• # Journal of Earth System Science

Volume 130, 2021
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019