Print Email Facebook Twitter Modeling Multi-Fraction Coastal Aeolian Sediment Transport With Horizontal and Vertical Grain-Size Variability Title Modeling Multi-Fraction Coastal Aeolian Sediment Transport With Horizontal and Vertical Grain-Size Variability Author van IJzendoorn, Christa (TU Delft Coastal Engineering) Hallin, E.C. (TU Delft Coastal Engineering; Lund University) Reniers, A.J.H.M. (TU Delft Environmental Fluid Mechanics) de Vries, S. (TU Delft Coastal Engineering) Date 2023 Abstract Grain size affects the rates of aeolian sediment transport on beaches. Sediment in coastal environments typically consists of multiple grain-size fractions and exhibits spatiotemporal variations. Still, conceptual and numerical aeolian transport models are simplified and often only include a single fraction that is constant over the model domain. It is unclear to what extent this simplification is valid and if the inclusion of multi-fraction transport and spatial grain-size variations affects aeolian sediment transport simulations and predictions of coastal dune development. This study applies the numerical aeolian sediment transport model AeoLiS to compare single-fraction to multi-fraction approaches for a range of grain-size distributions and spatial grain-size scenarios. The results show that on timescales of days to years, single-fraction simulations with the median grain size, D50, often give similar results to multi-fraction simulations, provided the wind is able to mobilize all fractions within that time frame. On these timescales, vertical variability in grain size has a limited effect on total transport rates, but it does influence the simulation results on minute timescales. Horizontal grain-size variability influences both the total transport rates and the downwind bed grain-size composition. The results provide new insights into the influence of beach sediment composition and spatial variability on total transport rates toward the dunes. The findings of this study can guide the implementation of grain-size variability in numerical aeolian sediment transport models. Subject aeolian processesAeoLiSbeachescoastal processesgrain sizemodelingnearshore processessediment transport To reference this document use: http://resolver.tudelft.nl/uuid:76b83523-5b61-4f2a-ba13-b2625a1f1058 DOI https://doi.org/10.1029/2023JF007155 ISSN 2169-9003 Source Journal of Geophysical Research: Earth Surface, 128 (7) Part of collection Institutional Repository Document type journal article Rights © 2023 Christa van IJzendoorn, E.C. Hallin, A.J.H.M. Reniers, S. de Vries Files PDF JGR_Earth_Surface_2023_IJ ... al_and.pdf 3.94 MB Close viewer /islandora/object/uuid:76b83523-5b61-4f2a-ba13-b2625a1f1058/datastream/OBJ/view