River bank instability from unsustainable sand mining in the lower Mekong River

Hackney, Christopher R.; Darby, Stephen; Parsons, Daniel R.; Leyland, Julian; Best, James; Aalto, Rolf; Nicholas, Andrew; Houseago, Robert

Abstract

Recent growth of the construction industry has fuelled demand for sand, with considerable volumes being extracted from the world’s large rivers. Sediment transport from upstream naturally replenishes sediment stored in river beds, but the absence of sand flux data from large rivers inhibits assessment of the sustainability of ongoing sand mining. Here, we demonstrate that bedload (0.18 Mt yr-1 ± 0.07 Mt yr-1) is a small (1%) fraction of the total annual sediment load of the lower Mekong River. Even when considering suspended sand (6 Mt yr-1 ± 2 Mt), the total sand flux entering the Mekong delta (6.18 Mt yr-1 ± 2.01 Mt yr-1) is far less than current sand extraction rates (50 Mt yr-1). We show that at these current rates, river bed levels can be lowered sufficiently to induce river bank instability, potentially damaging housing, infrastructure and threatening lives. Our research suggests that, on the Mekong and other large rivers subject to excessive sand mining, it is imperative to establish regulatory frameworks that limit extraction rates to levels that permit the establishment of a sustainable balance between the natural supply/storage of sand and the rate at which sand is removed.

Citation

Hackney, C. R., Darby, S., Parsons, D. R., Leyland, J., Best, J., Aalto, R., Nicholas, A., & Houseago, R. (2020). River bank instability from unsustainable sand mining in the lower Mekong River. Nature Sustainability, 3(3), 217-225. https://doi.org/10.1038/s41893-019-0455-3

• Journal Article Type: Article
• Acceptance Date: Nov 18, 2019
• Online Publication Date: Jan 13, 2020
• Publication Date: 2020-03
• Deposit Date: Jan 13, 2020
• Publicly Available Date: Jul 14, 2020
• Journal: Nature Sustainability
• Electronic ISSN: 2398-9629
• Publisher: Nature Research (part of Springer Nature)
• Peer Reviewed: Peer Reviewed
• Volume: 3
• Issue: 3
• Pages: 217-225
• DOI: https://doi.org/10.1038/s41893-019-0455-3
• Public URL: https://hull-repository.worktribe.com/output/3199599
• Publisher URL: https://www.nature.com/natsustain/?gclid=EAIaIQobChMI4rzjkMT25QIVia3tCh01BQ6kEAAYASAAEgIf3fD_BwE
• Additional Information: Received: 1 July 2019; Accepted: 18 November 2019; First Online: 13 January 2020; : The authors declare no competing interests.
• Contract Date: Jan 13, 2020