Shahid Beheshti University Researches in Earth Sciences 2008-8299 7 4 2016 10 22 Determining Bankfull Discharge and Stream Power of Lighvan River based on Morphometric Characteristics of the Channel Determining Bankfull Discharge and Stream Power of Lighvan River based on Morphometric Characteristics of the Channel 139 152 96111 FA Journal Article 2016 02 20 Assessment of bankfull discharge and stream power is very important for the restoration and river management. Due to the high level of correlation with acceptable accuracy between morphometric characteristics of the channel and bankfull discharge so in this study, first, the morphometric parameters of the channel was measured through surveying of the 12 cross-section of the Lighvan River and then bankfull discharge, flow velocity, bed roughness coefficient were calculated by Manning equations and stream power and stream power per river width unit were estimated and finally peak discharge with different return periods was obtained to determine the return periods of bankfull discharge. The results showed that bankfull discharge was varied from 0.92 to 35.83 cubic meters per second and also stream power in the 12 cross-sections was varied ranged from 216.65 to 7374.27. The most bankfull discharge and stream power were related to cross section 9 and 2 that has been due to the connection of two branches of the river in the place of these cross sections and located of these two sections in residential area. Lighvan River energy to make changes was ranging from high (A) and medium (B). Also return periods of bankfull discharge was very varied due to changes in cross sections dimensions and its amount was not increasing trend from upstream to the downstream that shows effect of unnatural factors such as changes in vegetation and human interventions in the channel morphology of Lighvan River. Assessment of bankfull discharge and stream power is very important for the restoration and river management. Due to the high level of correlation with acceptable accuracy between morphometric characteristics of the channel and bankfull discharge so in this study, first, the morphometric parameters of the channel was measured through surveying of the 12 cross-section of the Lighvan River and then bankfull discharge, flow velocity, bed roughness coefficient were calculated by Manning equations and stream power and stream power per river width unit were estimated and finally peak discharge with different return periods was obtained to determine the return periods of bankfull discharge. The results showed that bankfull discharge was varied from 0.92 to 35.83 cubic meters per second and also stream power in the 12 cross-sections was varied ranged from 216.65 to 7374.27. The most bankfull discharge and stream power were related to cross section 9 and 2 that has been due to the connection of two branches of the river in the place of these cross sections and located of these two sections in residential area. Lighvan River energy to make changes was ranging from high (A) and medium (B). Also return periods of bankfull discharge was very varied due to changes in cross sections dimensions and its amount was not increasing trend from upstream to the downstream that shows effect of unnatural factors such as changes in vegetation and human interventions in the channel morphology of Lighvan River. https://esrj.sbu.ac.ir/article_96111_8620cea9a5055d5f3de1591d286b1b74.pdf