Exploiting sediment- and morpho-dynamics in coastal adaptation strategies to sea-level rise: a case study of the Vietnamese Mekong Delta
Nguyen, T.V.; Shannon, K.; De Meulder, B. (2021). Exploiting sediment- and morpho-dynamics in coastal adaptation strategies to sea-level rise: a case study of the Vietnamese Mekong Delta, in: Baumeister, J. et al. SeaCities. pp. 107-132. https://dx.doi.org/10.1007/978-981-15-8748-1_5 In: Baumeister, J.; Bertone, E.; Burton, P. (Ed.) (2021). SeaCities: Urban tactics for sea-level rise. Cities Research Series. Springer Nature: Singapore. ISBN 978-981-15-8747-4; e-ISBN 978-981-15-8748-1. XVII, 304 pp. https://dx.doi.org/10.1007/978-981-15-8748-1, more In: Cities Research Series. Springer Nature: Singapore. ISSN 2662-4842; e-ISSN 2662-4850, more |
| Authors | | Top | - Nguyen, T.V.
- Shannon, K., more
- De Meulder, B., more
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| Abstract | This chapter explores potential strategies to engage with sediment dynamics and coastal geomorphology in response to sea-level rise through a case study of the Vietnamese Mekong Delta. The delta has been formed by deposition of sediments during the last several thousand years. With a low elevation and significant land subsidence, it is among the most vulnerable deltas in the world under the impacts of climate change, sea-level rise and particularly flooding. Its entire coastline is characterized by a dynamic process of accretion and erosion. The chapter firstly provides an overview of geomorphology—concentrating on sedimentation and erosion—along the coast of the Mekong Delta, where most of the massive sediment discharge of the Mekong River is trapped on the subaqueous delta area and two-thirds of the sediment is transported southeastwards to the southernmost Ca Mau Cape. Then, the chapter draws lessons from an implemented local scale project on Vietnam’s East Sea (also referred to as the South China Sea), where bamboo fences are used to reduce coastal erosion and stimulate sedimentation. Permeable T-fences trap sediment and create calm water conditions for further deposition along the muddy coast. In turn, restoration of the eroded coastal floodplain creates pre-conditions for rehabilitation of the mangrove forest. Finally, the last section examines a coastal strategy, proposed in the Mekong Delta regional plan, to enhance controlled and increased sedimentation along the East Sea coast in order to drastically up-scale the natural land-gaining process, which can be further consolidated by the systematic planting of mangroves. By engaging with the complex circulation system of sediments along the coast, this strategy can initiate a new protective/productive landscape amidst a constructed ecology that will not only strengthen the ecological structure of the Mekong Delta, but also increase its resilience in the context of sea-level rise. However, it must be noted that sedimentation in the Mekong Delta is increasingly threatened by sediment supply deficit. |
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