Sjoukje I de Lange,Roeland C van de Vijsel,Paul J J F Torfs,Nick P Wallerstein,Antonius J F Hoitink
{"title":"Bimodality in subaqueous dune height suggests flickering behavior at high flow.","authors":"Sjoukje I de Lange,Roeland C van de Vijsel,Paul J J F Torfs,Nick P Wallerstein,Antonius J F Hoitink","doi":"10.1038/s41467-025-61248-5","DOIUrl":null,"url":null,"abstract":"River bedforms influence fluvial hydraulics by altering bed roughness. With increasing flow velocity, the sand-bedded river transitions from a flat bed to ripples, dunes, and an upper stage plane bed. Although prior research notes increased bedform height variation with flow strength and rapid shifts between bed configurations, the latter remains understudied. Here, we reveal flickering between low and high dune heights for transport stages exceeding 18, based on data from earlier experiments and a complementary experiment. Above this transport stage, the second mode in the dune height distributions becomes increasingly distinctive, suggesting a critical transition. The emergence of the second mode is potentially triggered by temporal changes in suspended sediment concentration impacting turbulence, or might result from dune kinematics enabling larger dunes to grow and persist longer. This flickering behavior challenges the adequacy of a single snapshot to capture the system's bed geometry, impacting field measurements and experimental designs, and questions a classical equilibrium equation in geomorphology. Our study calls for further research to understand and quantify flickering behavior in sediment beds at high transport stages.","PeriodicalId":19066,"journal":{"name":"Nature Communications","volume":"3 1","pages":"6317"},"PeriodicalIF":14.7000,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nature Communications","FirstCategoryId":"103","ListUrlMain":"https://doi.org/10.1038/s41467-025-61248-5","RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MULTIDISCIPLINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
River bedforms influence fluvial hydraulics by altering bed roughness. With increasing flow velocity, the sand-bedded river transitions from a flat bed to ripples, dunes, and an upper stage plane bed. Although prior research notes increased bedform height variation with flow strength and rapid shifts between bed configurations, the latter remains understudied. Here, we reveal flickering between low and high dune heights for transport stages exceeding 18, based on data from earlier experiments and a complementary experiment. Above this transport stage, the second mode in the dune height distributions becomes increasingly distinctive, suggesting a critical transition. The emergence of the second mode is potentially triggered by temporal changes in suspended sediment concentration impacting turbulence, or might result from dune kinematics enabling larger dunes to grow and persist longer. This flickering behavior challenges the adequacy of a single snapshot to capture the system's bed geometry, impacting field measurements and experimental designs, and questions a classical equilibrium equation in geomorphology. Our study calls for further research to understand and quantify flickering behavior in sediment beds at high transport stages.
期刊介绍:
Nature Communications, an open-access journal, publishes high-quality research spanning all areas of the natural sciences. Papers featured in the journal showcase significant advances relevant to specialists in each respective field. With a 2-year impact factor of 16.6 (2022) and a median time of 8 days from submission to the first editorial decision, Nature Communications is committed to rapid dissemination of research findings. As a multidisciplinary journal, it welcomes contributions from biological, health, physical, chemical, Earth, social, mathematical, applied, and engineering sciences, aiming to highlight important breakthroughs within each domain.