shamkhi, M.S. and Attab, Z.S. 2018. Estimation of Manning’s Roughness Coefficient for Tigris River by Using HEC-RAS model. Wasit Journal of Engineering Sciences. 6, 3 (Dec. 2018), 90–97. DOI:https://doi.org/10.31185/ejuow.Vol6.Iss3.107.