Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.geomorph.2022.108368
Title (Primary) Hydrodynamics, sediment transport, and morphodynamics in the Vietnamese Mekong Delta: Field study and numerical modelling
Author Binh, D.V.; Kantoush, S.A.; Ata, R.; Tassi, P.; Nguyen, V.T. ORCID logo ; Lepesqueur, J.; Abderrezzak, K.E.K.; Bourban, S.E.; Nguyen, Q.H.; Phuong, D.N.L.; Trung, L.V.; Tran, D.A.; Letrung, T.; Sumi, T.
Source Titel Geomorphology
Year 2022
Department HDG
Volume 413
Page From art. 108368
Language englisch
Topic T5 Future Landscapes
Supplements https://ars.els-cdn.com/content/image/1-s2.0-S0169555X22002616-mmc1.docx
Keywords Morphological change; Diversion channel; Riverbed incision; Scour hole; Sediment reduction; 2D numerical modelling
Abstract Flow, suspended sediment transport and associated morphological changes in the Vietnamese Mekong Delta (VMD) are studied using field survey data and a two-dimensional (2D) depth-averaged hydromorphodynamic numerical model. The results show that approximately 61–81 % of the suspended sediment load in the Hau River during the flood seasons is diverted from the Tien River by a water and suspended sediment diversion channel. Tidal effects on flow and suspended sediment load are more pronounced in the Hau River than in the Tien River. The results show the formation of nine scour holes in the Tien River and seven scour holes in the Hau River from 2014 to 2017. Additional six scour holes are likely to form by the end of 2026 if the suspended sediment supply is reduced by 85 % due to damming. Notably, the scour holes are likely to form at locations of severe riverbank erosion. In the entire study area, the simulated total net incision volume in 2014–2017 is approximately 196 Mm3 (equivalent to 65.3 Mm3/yr). The predicted total net incision volumes from 2017 to 2026 are approximately 2472 and 3316 Mm3 under the 18 % and 85 % suspended sediment reduction scenarios, respectively, thereby likely threatening the delta sustainability. The methodology developed in this study is helpful in providing researchers and decision-makers with one way to predict numerically the scour hole formation and its association with riverbank stability in river deltas. Of equal importance, this research serves as a useful reference on the role of water and suspended sediment diversion channels in balancing landforms in river-delta systems, particularly where artificial diversion channels are planned.

Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=26329
Binh, D.V., Kantoush, S.A., Ata, R., Tassi, P., Nguyen, V.T., Lepesqueur, J., Abderrezzak, K.E.K., Bourban, S.E., Nguyen, Q.H., Phuong, D.N.L., Trung, L.V., Tran, D.A., Letrung, T., Sumi, T. (2022):
Hydrodynamics, sediment transport, and morphodynamics in the Vietnamese Mekong Delta: Field study and numerical modelling
Geomorphology 413 , art. 108368 10.1016/j.geomorph.2022.108368