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Establishing sustainable sediment budgets is critical for climate-resilient mega-deltas

Vasilopoulos, G.; Quan, Q. L.; Parsons, D. R.; Darby, S. E.; Tri, V P D; Hung, N. N.; Haigh, I. D.; Voepel, H. E.; Nicholas, A. P.; Aalto, R.


Q. L. Quan

D. R. Parsons

S. E. Darby

V P D Tri

N. N. Hung

I. D. Haigh

H. E. Voepel

A. P. Nicholas

R. Aalto


Many of the world's major river deltas face a sustainability crisis, as they come under threat of increases in salinity and the extent of tidal zones forced by combinations of sea-level rise, changes in river discharge and channel geometry. The relative contribution of these factors to future increases in tidal extent remains unconstrained, with most prior work emphasising the role of climate-driven sea-level rise. Here we use new field data from the Mekong delta to measure variations of river discharge and changes of channel geometry, and project them into the future. We combine these with projections of future sea-level rise into a 2D hydrodynamic numerical model and quantify the influence of the different driving factors on future tidal extension into the delta. We show that within the next two decades, tidal extension into the Mekong delta will increase by up to 56 km due to channel deepening (92%), dominantly driven by anthropogenic sediment starvation. Furthermore, even under strong mitigation scenarios, sediment starvation still drives a long-term commitment to future tidal extension. Specifically, by 2098 eustatically rising sea-levels are predicted to contribute only modestly to the projected extension. These findings demonstrate the urgent need for policy makers to adopt evidence-based measures to reverse negative sediment budgets that drive tidal extension into sediment starved deltas.


Vasilopoulos, G., Quan, Q. L., Parsons, D. R., Darby, S. E., Tri, V. P. D., Hung, N. N., …Aalto, R. (2021). Establishing sustainable sediment budgets is critical for climate-resilient mega-deltas. Environmental Research Letters, 16(6), Article 064089.

Journal Article Type Article
Acceptance Date Jun 1, 2021
Online Publication Date Jun 16, 2021
Publication Date 2021-06
Deposit Date Jun 16, 2021
Publicly Available Date Jun 17, 2021
Journal Environmental Research Letters
Print ISSN 1748-9326
Electronic ISSN 1748-9326
Publisher IOP Publishing
Peer Reviewed Peer Reviewed
Volume 16
Issue 6
Article Number 064089
Keywords River deltas; Tidal extension; Sediment starvation; Climate resilience
Public URL


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Copyright Statement
© 2021 The Author(s). Published by IOP Publishing Ltd.
Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

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