Study of Hydrogeochemical Properties of Surface Water (Case Study: Comparison of Two Adjacent Catchments, Cheshmeh Kileh and Shiroud, Northern Iran)

Cheshmeh Kileh and Shiroud in southern Caspian Sea have very important as habitats for the migration and reproduction of valuable fishery species. According to the agricultural industry in the north of Iran, products such as kiwi fruits, citrus fruits, rice and greenhouse products are the dominant products in this area. EC and pH are one of the important parameters in agricultural sciences. Therefore, conducting comprehensive studies to determine factors affecting the chemical composition of water and sediment along the rivers can help to identify pollutants and controlling factors of water chemistry and the sustainable development of the region. Sampling sites were determined based on the geogenic and anthropogenic effects, and samples were collected in September 2021. Hydrogeochemical diagrams, irrigation, industrial and HMs indices were drawn or calculated. The results showed that one sample in Sehazar sub-river is under the influence of gypsum lithology in the Karaj Formation located upstream of Maran heights. In Cheshmeh Kileh Catchment, one sample had a higher amount of bicarbonate, sodium, potassium and HMs ions than other samples due to the infiltration of landfill waste water. Diagrams for Shiroud Catchment showed that in the estuary, the phenomenon of saltwater intrusion has occurred due to excessive sand and gravel harvesting. Therefore, the corrosion rate in this station is high, and for the construction of metal and reinforced concrete structures, caution and further investigations should be used to prevent damages. It is also suggested that EC and pH values are always controlled in agricultural activities.Article Highlights: The Cheshmeh Kileh and Shiroud are the most important rivers in western Mazandaran Province and ending at the Caspian Sea. Both rivers are very important as habitats for the migration and reproduction of valuable fishery species. In this area, the agricultural industry is very popular and they generally use surface water for irrigation. Based on the studies conducted on water samples, the dominant type in both catchments is calcium bicarbonate. The Cheshmeh Kileh catchment is affected by gypsum lithology in Karaj Formation (upstream) and landfill leachate in some samples. The Shiroud Catchment is affected by basalt lithology and saltwater intrusion in the river (estuary). [ABSTRACT FROM AUTHOR]