Deltas Capture 28% of Global River Sediment, Leaving the Rest to Flow into the Ocean

Deltas: Vital Land Accumulation Revealed by New Research

Editors’ Highlights from AGU’s Journal Insights

Source: AGU Advances

Deltas serve as critical regions that span across expansive areas, many of which are inhabited by human populations. While deltas are traditionally defined by the deposition of riverine sediments along coastlines, the extent to which these materials accumulate on deltas versus their eventual journey into the ocean remains ambiguous. The diverse formations and shapes of these deltas further complicate this question.

A recent study conducted by Nienhuis et al. (2026) employs a sophisticated model to analyze over 1,700 deltas globally. Their findings reveal that approximately 30% of all river-sourced sand and mud contributes to the formation of delta plains. Surprisingly, this accumulation is significant enough to replicate the volume of sediment that could fill the Empire State Building every two hours. This metric underscores the crucial role deltas play in land formation and highlights their potential in countering the impacts of sea level rise and land subsidence.

Citation: Nienhuis, J. H., Paniagua-Arroyave, J. F., Dunn, F. E., Cohen, S., & Törnqvist, T. E. (2026). Global river sediment retention on delta plains. AGU Advances, 7, e2026AV002503. https://doi.org/10.1029/2026AV002503

—M. Bayani Cardenas, Editor, AGU Advances

Text © 2026. The authors. CC BY-NC-ND 3.0
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