Research on the development of rivers and coasts and their natural systems, and the various services these systems can provide. Hereby, my particular interest is improving our understanding of these systems, so that they can be applied for the benefit of both the natural system and humans.

I received my BSc and MSc at the University of Twente, focussing on water engineering and management. By doing my graduation assignment on “Modelling Consequences of Artificial Structures on Salt Marsh Dynamics in the Wadden Sea” at HKV, I graduated in 2019. After, I started my PhD at the University of Twente,  where I am currently doing research on long-term, large-scale estuarine development subjected to nature-based solutions, for estuarine salt intrusion. These nature-based solutions can be either in the estuarine channel (e.g. artificial sand waves) or at its sides (e.g. wetlands or oyster beds). To overcome the various timescales involved in this research, process-based numerical modeling tools will be developed and combined into an efficient framework.

A brief pitch and an article on my MSc thesis project are available below.

https://www.youtube.com/watch?v=HGFz2e8Nbfg&feature=youtu.be

https://www.mdpi.com/2077-1312/8/5/326

Expertise

  • Earth and Planetary Sciences

    • Estuaries
    • Morphology
    • Climate Change
    • Nature-Based Solutions
    • Fine Sediment
    • Managed Realignment
    • Salt Marsh
    • Sea Level Rise

Organisations

Publications

2026

Salinity-induced stratification impacts tides in estuaries (2026)Advances in water resources, 215. Article 105388 (E-pub ahead of print/First online). Siemes, R. W. A. & Hulscher, S. J. M. H.https://doi.org/10.1016/j.advwatres.2026.105388How Managed Realignment Modifies Salt Intrusion in Short Estuaries (2026)Journal of geophysical research: Oceans, 131(5). Article e2025JC023485. Bootsma, J., Borsje, B. W., Siemes, R. W. A., Geerts, S. J., van der Wal, D. & Hulscher, S. J. M. H.https://doi.org/10.1029/2025JC023485Fine Sediment Dynamics Affected by Large-Scale Interventions: A 3D Modelling Study of An Engineered Estuary (2026)Estuaries and coasts, 49(1). Article 11. Siemes, R. W. A., Duong, T. M., Borsje, B. W. A. & Hulscher, S. J. M. H.https://doi.org/10.1007/s12237-025-01631-zCorrection: Fine Sediment Dynamics Affected by Large-Scale Interventions; A 3D Modelling Study of An Engineered Estuary (Estuaries and Coasts, (2026), 49, 1, (11), 10.1007/s12237-025-01631-z) (2026)Estuaries and coasts, 49(1). Article 20. Siemes, R. W. A., Duong, T. M., Borsje, B. W. & Hulscher, S. J. M. H.https://doi.org/10.1007/s12237-025-01641-xTidal propagation into rivers influenced by salt intrusion (2026)[Contribution to conference › Abstract] NCR Days 2026. Siemes, R. W. A. & Hulscher, S. J. M. H.https://cdn.bullit.digital/kbase/20260330140553/NCR_DAYS_proceedings_2026.pdf

2025

Managed Realignment and its Influence on Estuarine Salt Intrusion (2025)[Contribution to conference › Abstract] AGU Annual Meeting 2025. Bootsma, J., Borsje, B. W., Siemes, R. W. A., Geerts, S. J., van der Wal, D. & Hulscher, S. J. M. H.https://agu.confex.com/agu/agu25/meetingapp.cgi/Paper/1908062Salt Intrusion Affected by Large‐Scale Human Interventions and Sea Level Rise: A 3D Modeling Study of an Engineered Estuary (2025)Journal of geophysical research: Oceans, 130(6). Article e2025JC022504. Siemes, R. W. A., Duong, T. M., Borsje, B. W. & Hulscher, S. J. M. H.https://doi.org/10.1029/2025JC022504Impact of restored intertidal area on salt intrusion in estuaries (2025)[Contribution to conference › Abstract] NCK Days 2025. Bootsma, J., Borsje, B. W., Siemes, R. W. A., van der Wal, D. & Hulscher, S. J. M. H.https://www.nck-web.org/boa-2025/983-managed-realignment-salt-intrusion

Research profiles

Address

University of Twente

Horst Complex (building no. 20), room W216
De Horst 2
7522 LW Enschede
Netherlands

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Organisations

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