TY - GEN
T1 - Formation of repeating bedforms (bars-flats) in ephemeral channels
T2 - 11th International Conference on Fluvial Hydraulics, River Flow 2022
AU - Massera, G.
AU - Siviglia, A.
AU - Tubino, M.
AU - Cohen, T.
AU - Laronne, J. B.
AU - Dorman, M.
AU - Reid, I.
AU - Powell, D. M.
N1 - Publisher Copyright:
© 2024 The Author(s).
PY - 2024/1/1
Y1 - 2024/1/1
N2 - Gravel bed channels of single-thread ephemeral streams in drylands are typified by alternations of steep, coarse-grained bars and less steep, fine-grained ‘flats’. The origin of both macroforms has been discussed but not fully explained. We studied the generation of this macroform sequence under field conditions. Relevantly, we provide a possible explanation regarding their formation, using a simple mathematical model fed by data obtained from field experiments carried out on the Yatir channel in the northern Negev, Israel. The mathematical model is developed considering the one-dimensional model of flow over an erodible bed composed of a bimodal mixture of sediments. The solution is obtained via the application of linear stability analysis. Results suggest that the bar-flat pattern occurs when the standard deviation of the sediment mixture is relatively large, as in the case of the Yatir channel, and the flow approaches critical conditions for bedload transport.
AB - Gravel bed channels of single-thread ephemeral streams in drylands are typified by alternations of steep, coarse-grained bars and less steep, fine-grained ‘flats’. The origin of both macroforms has been discussed but not fully explained. We studied the generation of this macroform sequence under field conditions. Relevantly, we provide a possible explanation regarding their formation, using a simple mathematical model fed by data obtained from field experiments carried out on the Yatir channel in the northern Negev, Israel. The mathematical model is developed considering the one-dimensional model of flow over an erodible bed composed of a bimodal mixture of sediments. The solution is obtained via the application of linear stability analysis. Results suggest that the bar-flat pattern occurs when the standard deviation of the sediment mixture is relatively large, as in the case of the Yatir channel, and the flow approaches critical conditions for bedload transport.
UR - http://www.scopus.com/inward/record.url?scp=85202440837&partnerID=8YFLogxK
U2 - 10.1201/9781003323037-38
DO - 10.1201/9781003323037-38
M3 - Conference contribution
AN - SCOPUS:85202440837
SN - 9781032346137
T3 - River Flow - Proceedings of the 11th Conference on Fluvial Hydraulics, 2022
SP - 277
EP - 281
BT - River Flow - Proceedings of the 11th Conference on Fluvial Hydraulics, 2022
A2 - da Silva, Ana Maria Ferreira
A2 - Rennie, Colin
A2 - Gaskin, Susan
A2 - Lacey, Jay
A2 - MacVicar, Bruce
PB - CRC Press/Balkema
Y2 - 8 November 2022 through 10 November 2022
ER -