Print Email Facebook Twitter Sediment Nourishments to Mitigate Channel Bed Incision in Engineered Rivers Title Sediment Nourishments to Mitigate Channel Bed Incision in Engineered Rivers Author Czapiga, Matthew J. (TU Delft Rivers, Ports, Waterways and Dredging Engineering) Blom, A. (TU Delft Rivers, Ports, Waterways and Dredging Engineering) Viparelli, Enrica (University of South Carolina) Date 2022 Abstract Engineering modifications of rivers, e.g., dams or groynes, often induce long-term riverbed erosion, which can be mitigated with sediment nourishments. Here, we consider nourishments to mitigate channel bed erosion induced by channel narrowing, as opposed to the more common application downstream of dams. Our objective is to assess and quantify how dumping location, grainsize, and volume are important for mitigation efficacy. Our results show that erosion can be mitigated if nourishments change the sediment flux such that the corresponding equilibrium channel slope is increased. This is achieved by coarsening the sediment flux throughout the reach, increasing magnitude of the sediment flux, or both. Flux is coarsened via additions of sediment at or coarser than the bed surface and nourished sediment should be distributed throughout the incising reach. The second option is nourishing a large volume of relatively fine sediment to increase the equilibrium channel slope. Additions of fine sediment in small volumes decrease the equilibrium channel slope and enhance erosion, because the fine sediment flux makes the gravel more mobile. To reference this document use: http://resolver.tudelft.nl/uuid:93616d94-2f15-4480-9ee9-88c1abff53e9 DOI https://doi.org/10.1061/(ASCE)HY.1943-7900.0001977 Embargo date 2023-07-01 ISSN 0733-9429 Source Journal of Hydraulic Engineering (Reston), 148 (6) Bibliographical note Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2022 Matthew J. Czapiga, A. Blom, Enrica Viparelli Files PDF _ASCE_HY.1943_7900.0001977.pdf 1.97 MB Close viewer /islandora/object/uuid:93616d94-2f15-4480-9ee9-88c1abff53e9/datastream/OBJ/view