Estimation of Manning’s Roughness Coefficient for Tigris River by Using HEC-RAS model

Abstract

Tigris River (downstream of the kut barrage reach) there is no study conducted on it to estimate its Manning n value. HEC-RAS was used to analysis study reach and calibrate n value of the study reach .filed data were collected during 2016-2017 (duration of study), eights data sets were observed included stage and discharge measurements. The discharge is controlled by Kut Barrage Operation. The range of water surface elevation is (+10.300 to +12.511) and flow discharge range is (202.7 - 355.280) m3/sec. The range of n value for study reach is (0.021-0.034). The calibration results provided suitable Manning n of 0.026 for downstream of Kut Barrage reach which represent mean value of results.