Use of algal indices for determining of water quality in the Sirvan River tributaries (Kurdistan-Iran)

Zhaveh Dam was built on the Sirvan River (Sanandaj-Iran), after the cross of the two main branches namely Gaveh-rood and Gheshlagh, with the aim of being used in agriculture and industry. Due to the importance and mutual relation between algae and water quality, this paper is going to study water quality based on algal indicators (phytoplankton and algal periphyton) in this basin for the first time. Seasonal sampling was conducted in ۵ stations, from the upstream to the reservoir of the dam from the fall of ۲۰۲۰ to the summer of ۲۰۲۱. The saprobic index value classified the water in the "medium organic polution" group in all samples. Most of the of Palmer's index values (especially in algal periphyton) indicated to” moderate to heavy” pollution of organic matter. Also, based on the “diatom species resistant to organic pollution” about ۶۸% (phytoplankton) and ۸۳% (algal periphyton) samples clssified in “organic pollution likely to contribute significantly to eutrophication” and “heavily contamination with organic pollution” groups. Most of the Diatom Trophic Index (TDI) values in water and periphyton were mor than ۳.۵ and in they were in” hypertrophic condition, with very high nutrient load”. As a conclusion, the high nutrients load and organic pollution in the river show the need to optimize wastewater treatment plants, control the entries of wastewaters into the river, and improve and rehabilitation the river, as prerequisites for any planning and water use.

Keywords:

Algal indicators , Water quality , Pollution , Trophic level , Sirvan River , Kurdistan