Potential Sediment within a Reach in Tigris River

摘要

The length of the reach river for the study area is (19.5 Km) lies in Northern of Tigris river between Al- Muthana bridge and Sarai gauging station in Baghdad city in Iraq. HEC-RAS version (5.03) was employed by making use of recorded field measurements data for running, calibration and verification processes. A new equation for the rating curve was introduced to estimate the water surface elevation at the upstream and downstream of the river reach. This rating curve was created by using four flow rate scenarios (461, 890, 1815 and 2500 m~3/s) in which water surface elevation ranging between 26.67 and 33.45 (m.a.s.l). For sediment transport analysis Laursen (Copeland) formula showed a good agreement with the measured field data. Changes in the river bed have been studied for the period from 2012 to 2017. The depth of erosion and sedimentation were calculated at the upstream and downstream of the river reach which are equal to 0.51 and 0.39 m, respectively. The cumulative average depth of the erosion of the river bed for the future period from 2017 to 2040 was estimated to be about 1 m for discharge of (461 m~3/s).