The impact of river meandering on water level fluctuation and suspended sediment concentration-Arvanrood case study

Sadrinasab, Masoud; Fayaz Mohammadi, Mohammad; Chegini, Vahid; Ashtari Larki, Amir

doi:10.22113/jmst.2017.45982

The impact of river meandering on water level fluctuation and suspended sediment concentration-Arvanrood case study

Document Type : Original Manuscript

Authors

masoud sadrinasab ¹

mohammad fayaz mohammadi ²

Vahid Chegini ³

amir ashtari larki ²

¹ Faculty of Environment, University of Tehran, Iran

² physical oceanography, Marine and Oceanic Science Faculty, University of Marine Science & Technology, Khorramshahr, Iran.

³ Iranian national institute for oceanography and atmosphere science

10.22113/jmst.2017.45982

Abstract

Arvandrood is the most important shipping river at the border of Iran and Iraq at the north of the Persian Gulf. As the border is determined by the talweg of the river, the changes of the talweg, as a result of erosion and deposition, is always considering. As a reason of inertia, current of the river tends to keep his direction forward. In meanders which the current has to change his direction, the sidewalls of the river experience severe shear stress that leads to sharp decrease of current energy and water level fluctuation, and increase of suspended sediment concentration. To simulate this in Arvandrood river, a 3D hydrodynamic model, DHI MIKE 21/3, has been employed. This model is based on a flexible mesh and the numerical solution of the two/three dimensional incompressible Reynolds averaged Navier-Stokes equations invoking the assumptions of Boussinesq and of hydrostatic pressure. In the first step, the model results were verified by the measured data in 4 stations. Comparing the water level in Faw position was shown that the Root Mean Square Error is 0.16 which is a good figure. Then, the model outputs were analyzed which show that in a straight direction of 18 kilometer from Abadan to Khosroabad, water level fluctuation and suspended sediment concentration have increased 18% and 3.8% respectively; while it is 22% and 15% in a way of 17 kilometer with two meander.

Keywords

Arvandrood

river meandering

Suspended Sediment

Numerical modelling

Mike 21/3