TY - JOUR
T1 - Long-term morphological developments of river channels separated by a longitudinal training wall
AU - Le, Binh
AU - Crosato, Alessandra
AU - Uijttewaal, Wim
PY - 2018
Y1 - 2018
N2 - Rivers have been trained for centuries by channel narrowing and straightening. This caused important damages to their ecosystems, particularly around the bank areas. We analyse here the possibility to train rivers in a new way by subdividing their channel in main and ecological channel with a longitudinal training wall. The effectiveness of longitudinal training walls in achieving this goal and their long-term effects on the river morphology have not been thoroughly investigated yet. In particular, studies that assess the stability of the two parallel channels separated by the training wall are still lacking. This work studies the long-term morphological developments of river channels subdivided by a longitudinal training wall in the presence of steady alternate bars. This type of bars, common in alluvial rivers, alters the flow field and the sediment transport direction and might affect the stability of the bifurcating system. The work comprises both laboratory experiments and numerical simulations (Delft3D). The results show that a system of parallel channels divided by a longitudinal training wall has the tendency to become unstable. An important factor is found to be the location of the upstream termination of the longitudinal wall with respect to a neighboring steady bar. The relative widths of the two parallel channels separated by the wall and variable discharge do not substantially change the final evolution of the system.
AB - Rivers have been trained for centuries by channel narrowing and straightening. This caused important damages to their ecosystems, particularly around the bank areas. We analyse here the possibility to train rivers in a new way by subdividing their channel in main and ecological channel with a longitudinal training wall. The effectiveness of longitudinal training walls in achieving this goal and their long-term effects on the river morphology have not been thoroughly investigated yet. In particular, studies that assess the stability of the two parallel channels separated by the training wall are still lacking. This work studies the long-term morphological developments of river channels subdivided by a longitudinal training wall in the presence of steady alternate bars. This type of bars, common in alluvial rivers, alters the flow field and the sediment transport direction and might affect the stability of the bifurcating system. The work comprises both laboratory experiments and numerical simulations (Delft3D). The results show that a system of parallel channels divided by a longitudinal training wall has the tendency to become unstable. An important factor is found to be the location of the upstream termination of the longitudinal wall with respect to a neighboring steady bar. The relative widths of the two parallel channels separated by the wall and variable discharge do not substantially change the final evolution of the system.
KW - Longitudinal training wall
KW - River morphology
KW - River bars
KW - Channel stability
KW - Delft3D
KW - Laboratory experiments
UR - http://resolver.tudelft.nl/uuid:c7c7911e-4016-4cbf-8683-704ade849f01
U2 - 10.1016/j.advwatres.2018.01.007
DO - 10.1016/j.advwatres.2018.01.007
M3 - Article
SN - 0309-1708
VL - 113
SP - 73
EP - 85
JO - Advances in Water Resources
JF - Advances in Water Resources
ER -