three places were picked out along the river in three regions at the top, in the center, and at the rear end of the river, according to the texture of the riverside and difference in biological, chemical, and physical agents.. ST1 (Garmabdareh) was selected as a reference site was primarily vegetated with relatively mature native forest, short or no residential development, and no permitted discharges (coal mining, petroleum/gas extraction, or sewage treatment plants). ST2 (Meygoon) and ST3 (Roodak) were Non-reference sites, or test sites with span a range of observed human impacts to the watershed, stream, or individual reach (Fig.1).
Figure