Evaluation of the Seasonal Variation Trend of water Quality of Qezel-Ozan River by Sub Branches Effects Using Agriculturalindices

Hydrochemistry studies play an important role in the management and efficient and correct using of water
resources. Mainobjectives ofthese studiesare identifythe limitations ofusingwater resources,situations
of crisis and Suitable andunsuitablelocations with different consumptions,such asAgriculture. In this
regardchanges in Qezel-Ozanwater quality an indicator in terms of agricultural were monitoredinthis
study. 64 sites along the main Qezel-Ozan River and 22 sites of the major sub-branches were chosen that
leading to this river.Samplingwas conducted on the days without rain in the springandsummer season,
in May and September. The results showed that thegreatestchanges have been in theKhodabande, Ijrod,
Mahneshan, andZanjan. Talwar and Bezinerod have most corrupting influence on the quality of the Qezel-
Ozan River.These rivers are poured of Khodabande and Ijrod lands. But other rivers in downstream have
a positive impact on Qezel-OzanRiver’s quality because of their good quality. So when move to the end
of the river route, water quality improve thata major factor in this part is perfect quality of sub branches
in downstream. The results in comparison of Qezel-Ozan river’s quality in spring (May) andsummer
(August) showed significant differences between measured chemical properties. Concentration of the
most parameters increased in the summer and thus water quality in thespring is lower than summer.