Impact of dams and climate change on suspended sediment flux to the Mekong delta
Impact of dams and climate change on suspended sediment flux to the Mekong delta
The livelihoods of millions of people living in the world's deltas are deeply interconnected with the sediment dynamics of these deltas. In particular a sustainable supply of fluvial sediments from upstream is critical for ensuring the fertility of delta soils and for promoting sediment deposition that can offset rising sea levels. Yet, in many large river catchments this supply of sediment is being threatened by the planned construction of large dams. In this study, we apply the INCA hydrological and sediment model to the Mekong River catchment in South East Asia. The aim is to assess the impact of several large dams (both existing and planned) on the suspended sediment fluxes of the river. We force the INCA model with a climate model to assess the interplay of changing climate and sediment trapping caused by dam construction. The results show that historical sediment flux declines are mostly caused by dams built in PR China and that sediment trapping will increase in the future due to the construction of new dams in PDR Lao and Cambodia. If all dams that are currently planned for the next two decades are built, they will induce a decline of suspended sediment flux of 50% (47–53% 90% confidence interval (90%CI)) compared to current levels (99 Mt/year at the delta apex), with potentially damaging consequences for local livelihoods and ecosystems.
Climate change, INCA model, Large dams, Mekong River, Sediment transport
Bussi, Gianbattista
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Darby, Stephen E.
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Whitehead, Paul G.
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Jin, Li
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Dadson, Simon J.
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Voepel, Hal E.
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Vasilopoulos, Grigorios
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Hackney, Christopher R.
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Hutton, Craig
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Berchoux, Tristan
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Parsons, Daniel R.
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Nicholas, Andrew
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10 February 2021
Bussi, Gianbattista
cfb5a011-8549-496c-91ea-02f733d8d4d1
Darby, Stephen E.
4c3e1c76-d404-4ff3-86f8-84e42fbb7970
Whitehead, Paul G.
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Jin, Li
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Dadson, Simon J.
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Voepel, Hal E.
7330972a-c61c-4058-b52c-3669fadfcf70
Vasilopoulos, Grigorios
300d6991-00cb-409a-9412-021eeb96fa49
Hackney, Christopher R.
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Hutton, Craig
9102617b-caf7-4538-9414-c29e72f5fe2e
Berchoux, Tristan
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Parsons, Daniel R.
59f2673a-9c73-437a-8865-52d52830a3aa
Nicholas, Andrew
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Bussi, Gianbattista, Darby, Stephen E., Whitehead, Paul G., Jin, Li, Dadson, Simon J., Voepel, Hal E., Vasilopoulos, Grigorios, Hackney, Christopher R., Hutton, Craig, Berchoux, Tristan, Parsons, Daniel R. and Nicholas, Andrew
(2021)
Impact of dams and climate change on suspended sediment flux to the Mekong delta.
Science of the Total Environment, 755 (Part 1), [142468].
(doi:10.1016/j.scitotenv.2020.142468).
Abstract
The livelihoods of millions of people living in the world's deltas are deeply interconnected with the sediment dynamics of these deltas. In particular a sustainable supply of fluvial sediments from upstream is critical for ensuring the fertility of delta soils and for promoting sediment deposition that can offset rising sea levels. Yet, in many large river catchments this supply of sediment is being threatened by the planned construction of large dams. In this study, we apply the INCA hydrological and sediment model to the Mekong River catchment in South East Asia. The aim is to assess the impact of several large dams (both existing and planned) on the suspended sediment fluxes of the river. We force the INCA model with a climate model to assess the interplay of changing climate and sediment trapping caused by dam construction. The results show that historical sediment flux declines are mostly caused by dams built in PR China and that sediment trapping will increase in the future due to the construction of new dams in PDR Lao and Cambodia. If all dams that are currently planned for the next two decades are built, they will induce a decline of suspended sediment flux of 50% (47–53% 90% confidence interval (90%CI)) compared to current levels (99 Mt/year at the delta apex), with potentially damaging consequences for local livelihoods and ecosystems.
Text
manuscript_sediment_Mekong_GBussi_notrackchanges
- Accepted Manuscript
More information
Accepted/In Press date: 15 September 2020
e-pub ahead of print date: 28 September 2020
Published date: 10 February 2021
Keywords:
Climate change, INCA model, Large dams, Mekong River, Sediment transport
Identifiers
Local EPrints ID: 444632
URI: http://eprints.soton.ac.uk/id/eprint/444632
ISSN: 0048-9697
PURE UUID: 6fd90d2e-0743-4729-bc8e-cd60cde8ac83
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Date deposited: 28 Oct 2020 17:30
Last modified: 17 Mar 2024 06:01
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Contributors
Author:
Gianbattista Bussi
Author:
Paul G. Whitehead
Author:
Li Jin
Author:
Simon J. Dadson
Author:
Hal E. Voepel
Author:
Grigorios Vasilopoulos
Author:
Tristan Berchoux
Author:
Daniel R. Parsons
Author:
Andrew Nicholas
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