Channel‐planform evolution in four rivers of Olympic National Park, Washington, USA: the roles of physical drivers and trophic cascades

A 74-year analysis of four rivers in Olympic National Park reveals that physical factors, such as flood history and sediment supply, dominate channel planform evolution over ecological drivers like elk impacts. Contrary to expectations, the study found no significant correspondence between channel morphology and elk abundance, which had been linked to trophic cascades following wolf extirpation. Instead, recent widening and increased braiding in rivers like the Hoh and Elwha correlate with flood activity and sediment supply changes, including glacial retreat and landslide responses. These findings contrast with similar studies in Yellowstone National Park, highlighting the influence of hydrologic regime and large-wood availability on fluvial dynamics.

East, A. E., Jenkins, K. J., Happe, P. J., Bountry, J. A., Beechie, T. J., Mastin, M. C., Sankey, J. B., & Randle, T. J. (2016). Channel‐planform evolution in four rivers of Olympic National Park, Washington, USA: the roles of physical drivers and trophic cascades. Earth Surface Processes and Landforms, 42(7), 1011–1032. Portico. https://doi.org/10.1002/esp.4048