TY - JOUR
T1 - Sediment heterogeneity and mobility in the morphodynamic modelling of gravel-bed braided rivers
AU - Singh, Umesh
AU - Crosato, Alessandra
AU - Giri, Sanjay
AU - Hicks, Murray
PY - 2017/6/1
Y1 - 2017/6/1
N2 - The effects of sediment heterogeneity and sediment mobility on the morphology of braided rivers are still poorly studied, especially when the partial sediment mobility occurs. Nevertheless, increasing the bed sediment heterogeneity by coarse sediment supply is becoming a common practice in river restoration projects and habitat improvement all over the world. This research provides a step forward in the identification of the effects of sediment sorting on the evolution of sediment bars and braiding geometry of gravel-bed rivers. A two-dimensional morphodynamic model was used to simulate the long-term developments of a hypothetical braided system with discharge regime and morphodynamic parameters derived from the Waimakariri River, New Zealand. Several scenarios, differing in bed sediment heterogeneity and sediment mobility, were considered. The results agree with the tendencies already identified in linear analyses and experimental studies, showing that a larger sediment heterogeneity increases the braiding indes and reduces the bars length and height. The analyses allowed identifying the applicability limits of uniform sediment and variable discharge modelling approaches.
AB - The effects of sediment heterogeneity and sediment mobility on the morphology of braided rivers are still poorly studied, especially when the partial sediment mobility occurs. Nevertheless, increasing the bed sediment heterogeneity by coarse sediment supply is becoming a common practice in river restoration projects and habitat improvement all over the world. This research provides a step forward in the identification of the effects of sediment sorting on the evolution of sediment bars and braiding geometry of gravel-bed rivers. A two-dimensional morphodynamic model was used to simulate the long-term developments of a hypothetical braided system with discharge regime and morphodynamic parameters derived from the Waimakariri River, New Zealand. Several scenarios, differing in bed sediment heterogeneity and sediment mobility, were considered. The results agree with the tendencies already identified in linear analyses and experimental studies, showing that a larger sediment heterogeneity increases the braiding indes and reduces the bars length and height. The analyses allowed identifying the applicability limits of uniform sediment and variable discharge modelling approaches.
KW - Delft3D
KW - Graded sediment
KW - Gravel-bed braided rivers
KW - Meyer Peter and Müller formula
KW - Morphodynamic modelling
KW - Variable discharge
UR - http://www.scopus.com/inward/record.url?scp=85016482282&partnerID=8YFLogxK
U2 - 10.1016/j.advwatres.2017.02.005
DO - 10.1016/j.advwatres.2017.02.005
M3 - Article
AN - SCOPUS:85016482282
SN - 0309-1708
VL - 104
SP - 127
EP - 144
JO - Advances in Water Resources
JF - Advances in Water Resources
ER -