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


Recent growth of the construction industry has fuelled the 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 ± 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 ± 2 Mt yr−1), the total sand flux entering the Mekong delta (6.18 ± 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 and 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.

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Fig. 1: Sediment dynamics of the Mekong River.
Fig. 2: Bedload transport functions for the Mekong River.
Fig. 3: Morphological impacts of sand mining on river bathymetry.
Fig. 4: The impact of channel bed lowering on river bank stability.

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Data availability

The raw bedload transport data collected with the multibeam echo sounder, the discharge and suspended sediment data generated from the ADCP, and bank profiles collected with the terrestrial laser scanner that support the findings of this study are available from the corresponding author upon reasonable request. The water discharge data used to generate the bedload ratings curves are from the hydrological records archived in the Mekong River Commission data portal (; discharge records from Kratie (station identifier 014901; unique dataset accession 2811)).


  1. World Urbanization Prospects 2018—World’s Largest Cities (United Nations, 2018).

  2. Klee, H. The Cement Sustainability Initiative Recycling Concrete (WBSCD, 2009).

  3. Monteiro, P. J. M., Miller, S. A. & Horvath, A. Towards sustainable concrete. Nat. Mater. 16, 698–699 (2017).

    Article  CAS  Google Scholar 

  4. Peduzzi, P. Sand, rarer than one thinks. Environ. Dev. 11, 208–218 (2014).

    Article  Google Scholar 

  5. Mineral Commodities Summary 2015 (USGS, 2015).

  6. Torres, A., Brandt, J., Lear, K. & Liu, J. A looming tragedy of the sand commons. Science 357, 970–971 (2017).

    Article  CAS  Google Scholar 

  7. Nittrouer, J. A. & Viparelli, E. Sand as a stable and sustainable resource for nourishing the Mississippi River delta. Nat. Geosci. 7, 350–354 (2014).

    Article  CAS  Google Scholar 

  8. Best, J. Anthropogenic stresses on the world’s big rivers. Nat. Geosci. 12, 7–21 (2019).

    Article  CAS  Google Scholar 

  9. Bendixen, M., Best, J. L., Hackney, C. R. & Iversen, L. L. Time is running out for sand. Nature 571, 29–31 (2019).

    Article  CAS  Google Scholar 

  10. Milliman, J. D. & Farnsworth, K. L. River Discharge to the Coastal Ocean (Cambridge Univ. Press, 2011).

  11. The Flow of the Mekong (Mekong River Commission, 2009).

  12. Darby, S. E. et al. Fluvial sediment supply to a mega-delta reduced by shifting tropical-cyclone activity. Nature 539, 276–279 (2016).

    Article  Google Scholar 

  13. Walling, D. E. The changing sediment loads of the world’s rivers. SGGW L. Reclam. 39, 3–20 (2008).

    Google Scholar 

  14. Lu, X., Kummu, M. & Oeurng, C. Reappraisal of sediment dynamics in the lower Mekong River, Cambodia. Earth Surf. Process. Landf. 39, 1855–1865 (2014).

    Article  Google Scholar 

  15. Anthony, E. J. et al. Linking rapid erosion of the Mekong River delta to human activities. Nat. Commun. 5, 14745 (2015).

    CAS  Google Scholar 

  16. Kondolf, G. M., Rubin, Z. K. & Minear, J. T. Dams on the Mekong: cumulative sediment starvation. Water Resour. Res. 50, 5158–5169 (2014).

    Article  Google Scholar 

  17. Koehnken, L. IKMP Discharge and Sediment Monitoring Programme Review, Recommendations and Data Analysis. Part 1: Program Review & Recommendations (Mekong River Commission, 2012).

  18. Koehnken, L. IKMP Discharge and Sediment Monitoring Programme Review, Recommendations and Data Analysis. Part 2: Data Analysis of Preliminary Results (Mekong River Commission, 2012).

  19. Kondolf, G. M. et al. Changing sediment budget of the Mekong: cumulative threats and management strategies for a large river basin. Sci. Total Environ. 625, 114–134 (2018).

    Article  CAS  Google Scholar 

  20. Cochrane, T. A., Arias, M. E. & Piman, T. Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap system. Hydrol. Earth Syst. Sci. 18, 4529–4541 (2014).

    Article  Google Scholar 

  21. Räsänen, T. A. et al. Observed river discharge changes due to hydropower operations in the Upper Mekong Basin. J. Hydrol. 545, 28–41 (2017).

    Article  Google Scholar 

  22. Bravard, J.-P. & Goichot, M. Geography of sand and gravel mining in the lower Mekong River: first survey and impact assessment. EchoGéo (2013).

  23. Brunier, G., Anthony, E. J., Goichot, M., Provansal, M. & Dussouillez, P. Recent morphological changes in the Mekong and Bassac river channels, Mekong delta: the marked impact of river-bed mining and implications for delta destabilisation. Geomorphology 224, 177–191 (2014).

    Article  Google Scholar 

  24. Barman, B., Kumar, B. & Sarma, A. K. Turbulent flow structures and geomorphic characteristics of a mining affected alluvial channel. Earth Surf. Process. Landf. 43, 1811–1824 (2018).

    Article  Google Scholar 

  25. Kondolf, G. M. Hungry water: effects of dams and gravel mining on river channels. Environ. Manag. 21, 533–551 (1997).

    Article  CAS  Google Scholar 

  26. Ashraf, M. A., Maah, M. J., Yusoff, I., Wajid, A. & Mahmood, K. Sand mining effects, causes and concerns: a case study from Bestari Jaya, Selangor, Peninsular Malaysia. Sci. Res. Essays 6, 1216–1231 (2011).

    Google Scholar 

  27. Nittrouer, J. A., Allison, M. A. & Campanella, R. Bedform transport rates for the lowermost Mississippi River. J. Geophys. Res. Earth Surf. 113, F03004 (2008).

    Article  Google Scholar 

  28. Turowski, J. M., Rickenmann, D. & Dadson, S. J. The partitioning of the total sediment load of a river into suspended load and bedload: a review of empirical data. Sedimentology 57, 1126–1146 (2010).

    Article  Google Scholar 

  29. Koehnken, L. The ISH 0306 Study Development of Guidelines for Hydropower Environmental Impact Mitigation and Risk Management in the Lower Mekong Mainstream and Tributaries: Hydropower Risks and Impact Mitigation Guidelines and Recommendations (Mekong River Commission, 2014).

  30. Bagnold, R. A. An empirical correlation of bedload transport rates in flumes and natural rivers. Proc. R. Soc. A Math. Phys. Eng. Sci. 372, 453–473 (1980).

    Google Scholar 

  31. Schmitt, R. J. P., Rubin, Z. & Kondolf, G. M. Losing ground—scenarios of land loss as consequence of shifting sediment budgets in the Mekong Delta. Geomorphology 294, 58–69 (2017).

    Article  Google Scholar 

  32. Hackney, C. R. et al. The influence of flow discharge variations on the morphodynamics of a diffluence–confluence unit on a large river. Earth Surf. Process. Landf. 43, 349–362 (2018).

    Article  Google Scholar 

  33. Bravard, J.-P., Goichot, M. & Tronchère, H. An assessment of sediment-transport processes in the lower Mekong River based on deposit grain sizes, the CM technique and flow-energy data. Geomorphology 207, 174–189 (2014).

    Article  Google Scholar 

  34. Kazuaki, H., Shigeko, H. & Sieng, S. Sedimentary facies of borehole cores from the Mekong River floodplain in Cambodia. Geogr. Rev. Jpn 80, 681–692 (2007).

    Article  Google Scholar 

  35. Tamura, T. et al. Depositional facies and radiocarbon ages of a drill core from the Mekong River lowland near Phnom Penh, Cambodia: evidence for tidal sedimentation at the time of Holocene maximum flooding. J. Asian Earth Sci. 29, 585–592 (2007).

    Article  Google Scholar 

  36. Kubo, S. Geomorphological features and subsurface geology of the Lower Mekong Plain around Phnom Penh City, Cambodia (South East Asia). Rev. Geogr. Acad. 2, 20–32 (2008).

    Google Scholar 

  37. Tamura, T. et al. Initiation of the Mekong River delta at 8 ka: evidence from the sedimentary succession in the Cambodian lowland. Quat. Sci. Rev. 28, 327–344 (2009).

    Article  Google Scholar 

  38. Nguyen, V. L., Ta, T. K. O. & Saito, Y. Early Holocene initiation of the Mekong River delta, Vietnam, and the response to Holocene sea-level changes detected from DT1 core analyses. Sediment. Geol. 230, 146–155 (2010).

    Article  Google Scholar 

  39. Liu, P. et al. Stratigraphic formation of the Mekong River delta and its recent shoreline changes. Oceanography 30, 72–83 (2017).

    Article  Google Scholar 

  40. Uhlemann, S., Kuras, O., Richards, L. A., Naden, E. & Polya, D. A. Electrical resistivity tomography determines the spatial distribution of clay layer thickness and aquifer vulnerability, Kandal Province, Cambodia. J. Asian Earth Sci. 147, 402–414 (2017).

    Article  Google Scholar 

  41. Szupiany, R. N., Amsler, M. L., Best, J. L. & Parsons, D. R. Comparison of fixed- and moving-vessel flow measurements with an aDp in a large river. J. Hydrol. Eng. 133, 1299–1309 (2007).

    Article  Google Scholar 

  42. Parsons, D. R. R. et al. Velocity Mapping Toolbox (VMT): a processing and visualization suite for moving-vessel ADCP measurements. Earth Surf. Process. Landf. 38, 1244–1260 (2013).

    Article  Google Scholar 

  43. Lane, S. N., Bradbrook, K. F., Richards, K. S., Biron, P. M. & Roy, A. G. Secondary circulation cells in river channel confluences: measurement artefacts or coherent flow structures? Hydrol. Process. 14, 2047–2071 (2000).

    Article  Google Scholar 

  44. Kostaschuk, R., Best, J., Villard, P., Peakall, J. & Franklin, M. Measuring flow velocity and sediment transport with an acoustic Doppler current profiler. Geomorphology 68, 25–37 (2005).

    Article  Google Scholar 

  45. Szupiany, R. N., Amsler, M. L., Parsons, D. R. & Best, J. L. Morphology, flow structure, and suspended bed sediment transport at two large braid-bar confluences. Water Resour. Res. 45, W05415 (2009).

    Article  Google Scholar 

  46. Shugar, D. H. et al. On the relationship between flow and suspended sediment transport over the crest of a sand dune, Río Paraná, Argentina. Sedimentology 57, 252–272 (2010).

    Article  Google Scholar 

  47. Carson, M. A. & Kirkby, M. J. Hillslope Form and Process (Cambridge Univ. Press, 1972).

  48. Thorne, C. R., Murphey, J. B. & Little, W. C. Stream Channel Stability. Appendix D, Bank Stability and Bank Material Properties in the Bluffline Streams of Northwest Mississippi (USDA National Sedimentation Laboratory, 1981).

  49. Simon, A. & Hupp, C. R. Geomorphic and Vegetative Recovery Processes Along Modified Stream Channels of West Tennessee. US Geological Survey Open-File Report 91-502 (USGS, 1992).

  50. Handy, R. L. & Fox, J. S. A soil borehole direct-shear test device. Highway Res. News 27, 42–51 (1967).

    Google Scholar 

  51. Lohnes, R. A. & Handy, R. L. Slope angles in friable loess. J. Geol. 76, 247–258 (1968).

    Article  Google Scholar 

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This study was supported by awards NE/JO21970/1, NE/JO21571/1 and NE/JO21881/1 from the UK Natural Environment Research Council (NERC). We thank the Mekong River Commission for access to hydrological and suspended sediment data, and the Department of Hydrology and River Works in Cambodia for logistical support and help in the field. J.L.B. was in receipt of a University of Southampton Diamond Jubilee International Visiting Fellowship that aided the completion of this work.

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Authors and Affiliations



C.R.H., S.E.D., D.R.P., J.L., J.L.B., A.P.N. and R.A. jointly conceived the study. C.R.H., S.E.D., J.L., J.L.B., D.R.P., R.A. and R.C.H. collected and processed the field data. C.R.H. constructed the bedload transport functions and undertook the data analysis. C.R.H and S.E.D. undertook the bank stability analysis. C.R.H. drafted the paper, which was then edited by all co-authors.

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Correspondence to Christopher R. Hackney.

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Hackney, C.R., Darby, S.E., Parsons, D.R. et al. River bank instability from unsustainable sand mining in the lower Mekong River. Nat Sustain 3, 217–225 (2020).

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