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- Thewissen, A. (author), Hrachowitz, M. (author), Blom, A. (author) conference paper 2022
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- Ahrendt, S.M. (author), Blom, A. (author), van Denderen, R. Pepijn (author), Schielen, R.M.J. (author), Horner-Devine, Alexander (author) conference paper 2022
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- Chowdhury, M.K. (author), Blom, A. (author), Ylla Arbos, C. (author), Verbeek, Merel C. (author), Schropp, M.H.I. (author), Schielen, R.M.J. (author) conference paper 2022
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- Ylla Arbos, C. (author), Blom, A. (author), Schielen, R.M.J. (author) conference paper 2022
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- Czapiga, Matthew (author), Blom, A. (author), Viparelli, Enrica (author) conference paper 2022
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- Dercksen, J.A. (author), Stancanelli, L.M. (author), Blom, A. (author) conference paper 2022
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Czapiga, Matthew J. (author), Blom, A. (author), Viparelli, Enrica (author)The Waal Branch of the Rhine River has eroded over the last 150 years following channel straightening and narrowing. In 2014–2015 a pilot project replaced existing groynes over an 11 km long reach with three longitudinal training walls (LTWs) to mitigate channel bed erosion, among other purposes. Walls are lower than the river bank and split the...journal article 2022
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Czapiga, Matthew J. (author), Blom, A. (author), Viparelli, Enrica (author)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...journal article 2022
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Arkesteijn, L. (author), Blom, A. (author), Labeur, R.J. (author)Recent analysis of equilibrium and quasi-equilibrium channel geometry in engineered (fixed-width) rivers has successfully shown that two temporal scales can be distinguished, with quasi-static (long-term) and dynamic (short-term) components. This distinction is based on the fact that channel slope cannot keep pace with short-term fluctuations...journal article 2021
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Zeng, X. (author), Blom, A. (author), Czapiga, Matthew J. (author), An, Chenge (author), Parker, Gary (author), Fu, Xudong (author)For upland ephemeral gullies, gully erosion is strongly related to the formation and migration of cyclic steps. It is necessary to provide insight into the process of cyclic step development to accurately predict the pace of landscape evolution and soil loss. Information on the geometry of cyclic steps in subaerial environments is limited,...journal article 2021
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Andrikopoulou, T. (author), Schielen, R.M.J. (author), Spray, Chris J. (author), Schipper, Cor A. (author), Blom, A. (author)Nature-based solutions (NBSs) are measures reflecting the ‘cooperation with nature’ approach: mitigating fluvial flood risk while being cost-effective, resource-efficient, and providing numerous environmental, social, and economic benefits. Since 2015, the United Nations (UN) 2030 Agenda has provided UN member states with goals, targets, and...journal article 2021
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Ylla Arbos, C. (author), Blom, A. (author), Viparelli, E. (author), Reneerkens, M. (author), Frings, R. M. (author), Schielen, R.M.J. (author)While most of the world's large rivers are heavily engineered, channel response to engineering measures on decadal to century and several 100 km scales is scarcely documented. We investigate the response of the Lower Rhine River (Germany-Netherlands) to engineering measures, in terms of channel slope and bed surface grain size. Field data...journal article 2021
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Ylla Arbos, C. (author), Blom, A. (author), Acevedo Goldaracena, F. (author), van Vuren, S (author), Schielen, R.M.J. (author)The Rhine reach comprising the Niederrhein and the Upper Rhine Delta is characterized by a long history of engineering interventions. The area is densely populated and the Rhine, the main inland waterway in Europe, justifying the need for such measures. Interventions have had a strong impact on morphodynamic channel characteristics. We use bed...conference paper 2020
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Arkesteijn, L. (author), Blom, A. (author), Czapiga, Matthew J. (author), Chavarrias Borras, V. (author), Labeur, R.J. (author)An engineered alluvial river (i.e., a fixed-width channel) has constrained planform but is free to adjust channel slope and bed surface texture. These features are subject to controls: the hydrograph, sediment flux, and downstream base level. If the controls are sustained (or change slowly relative to the timescale of channel response), the...journal article 2019
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Chavarrias Borras, V. (author), Arkesteijn, L. (author), Blom, A. (author)The active layer model (Hirano, 1971) is frequently used for modeling mixed-size sediment river morphodynamic processes. It assumes that all the dynamics of the bed surface are captured by a homogeneous top layer that interacts with the flow. Although successful in reproducing a wide range of phenomena, it has two problems: (1) It may become...journal article 2019
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Chavarrias Borras, V. (author), Schielen, R.M.J. (author), Ottevanger, Willem (author), Blom, A. (author)A two-dimensional model describing river morphodynamic processes under mixed-size sediment conditions is analysed with respect to its well posedness. Well posedness guarantees the existence of a unique solution continuously depending on the problem data. When a model becomes ill posed, infinitesimal perturbations to a solution grow infinitely...journal article 2019
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Chavarrias Borras, V. (author), Stecca, Guglielmo (author), Siviglia, Annunziato (author), Blom, A. (author)A notable drawback in mixed-size sediment morphodynamic modeling is the fact that the most commonly used mathematical model in this field (i.e., the active layer model Hirano, 1971) can be ill-posed under certain circumstances. Under these conditions the model loses its predictive capabilities, as negligible perturbations in the initial or...journal article 2019
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Schielen, R.M.J. (author), Blom, A. (author)We derive an idealized model of a gravel-sand river bifurcation and analyze its stability properties. The model requires nodal point relations that describe the ratio of the supply of gravel and sand to the two downstream branches. The model predicts changes in bed elevation and bed surface gravel content in the two bifurcates under...journal article 2018
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Chavarrias Borras, V. (author), Stecca, Guglielmo (author), Labeur, R.J. (author), Blom, A. (author)The mixed-size character of sediment is a necessary property to ex- plain physical phenomena such as downstream fining or the presence of armor layers. The active layer model was developed to model mixed-size sediment in river morphodynamics. This model assumes that the topmost part of the bed, the active layer, has no vertical stratification...journal article 2018
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Siele, Meles (author), Blom, A. (author), Viparelli, Enrica (author)In response to changes in the upstream controls (i.e., the water discharge, the sediment supply rate, and the calibre of the load), engineered alluvial channels adjust their bed slope and bed surface texture to establish a new equilibrium state. Here we present and discuss various causes of degradational response of engineered channels to...journal article 2018