Universal relation with regime transition for sediment transport in fine-grained rivers

Hongbo Ma, Jeffrey A. Nittrouer, Baosheng Wu, Michael P. Lamb, Yuanfeng Zhang, David Mohrig, Xudong Fu, Kensuke Naito, Yuanjian Wang, Andrew J. Moodie, Guangqian Wang, Chunhong Hu, Gary Parker

Research output: Contribution to journalArticle

Abstract

Fine-grained sediment (grain size under 2,000 μm) builds floodplains and deltas, and shapes the coastlines where much of humanity lives. However, a universal, physically based predictor of sediment flux for fine-grained rivers remains to be developed. Herein, a comprehensive sediment load database for fine-grained channels, ranging from small experimental flumes to megarivers, is used to find a predictive algorithm. Two distinct transport regimes emerge, separated by a discontinuous transition for median bed grain size within the very fine sand range (81 to 154 μm), whereby sediment flux decreases by up to 100-fold for coarser sand-bedded rivers compared to river with silt and very fine sand beds. Evidence suggests that the discontinuous change in sediment load originates from a transition of transport mode between mixed suspended bed load transport and suspension-dominated transport. Events that alter bed sediment size near the transition may significantly affect fluviocoastal morphology by drastically changing sediment flux, as shown by data from the Yellow River, China, which, over time, transitioned back and forth 3 times between states of high and low transport efficiency in response to anthropic activities.

Original languageEnglish (US)
Pages (from-to)171-176
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume117
Issue number1
DOIs
StatePublished - Jan 7 2020

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Keywords

  • Critical suspension number
  • Fine-grained environments
  • Regime transition
  • Sediment transport
  • Universality

ASJC Scopus subject areas

  • General

Cite this

Ma, H., Nittrouer, J. A., Wu, B., Lamb, M. P., Zhang, Y., Mohrig, D., Fu, X., Naito, K., Wang, Y., Moodie, A. J., Wang, G., Hu, C., & Parker, G. (2020). Universal relation with regime transition for sediment transport in fine-grained rivers. Proceedings of the National Academy of Sciences of the United States of America, 117(1), 171-176. https://doi.org/10.1073/pnas.1911225116