Welcome...

dr.ir. A. Bomers (Anouk)

Assistant Professor

About Me

My scientific interests revolve around improving the computational efficiency of complex hydraulic river models. This involves two aspects, namely: improving the accuracy of hydraulic model predictions and decreasing computational times of highly-detailed hydraulic models. In my career, I focus on novel calibration methods and developing surrogate model techniques to simplify and replace our complex hydraulic river models. 

 

During my PhD, I focussed on reconstructing historic flood events of the Rhine river using various surrogate modelling approaches. By reconstructing historic flood events, the data set of measured discharges starting in 1900 could be extended with almost 600 years. With this extended data set design discharges corresponding to large return periods can be predicted with less uncertainty. This is of high importance for desinging our flood defences.

 

In my role as an Assistant Professor, I aim to ultimately develop efficient data-driven surrogate models that can replace the highly detailed hydraulic models such that these type of models can be used as a real-time flood forecasting system. However, these data-driven models rely on the accuracy of the original hydraulic models. Therefore, I also aim to increase reliability of hydraulic models by improving current calibration methods. For more information, please also see: https://www.utwente.nl/en/et/research/sector-plan/sectorplan-stories/bomers/

Expertise

Earth & Environmental Sciences
Dike
Flood Frequency
Floodplain
Hydraulics
Medieval
Modeling
River
River System

Publications

Recent
Ngo, H. Q. , Bomers, A. , Augustijn, D. C. M. , Ranasinghe, R. , Filatova, T. , & Hulscher, S. J. M. H. (2022). The discharge magnitude of the 1374 millennium flood event in the Rhine river. In Anthropogenic rivers. Book of abstracts NCR Days 2022 (pp. 14-14). Netherlands Centre for River Studies.
Lokin, L. , Warmink, J. J. , Bomers, A. , & Hulscher, S. J. M. H. (2021). Lengthening of river dunes during low flow in a sandy bed river. Paper presented at 5th International Symposium of Shallow Flows, Nanjing, China.
Ngo, H. Q. , Bomers, A. , Augustijn, D. C. M. , Ranasinghe, R., Filatova, T. , & Hulscher, S. J. M. H. (2021). Improving historic flood reconstruction using a detailed 1D-2D coupled hydraulic model approach. 69. Abstract from 4th International Conference on the Status and Future of the World's Large Rivers, Moscow, Russian Federation.
Bomers, A. , & Hulscher, S. J. M. H. (2021). The use of narx neural networks to predict the timing and location of dike breaches during river floods. 49. Abstract from 8th International Conference on Flood Management 2021, Iowa City, Iowa, United States.
Ngo, H. Q. , Bomers, A. , Augustijn, D. C. M. , Ranasinghe, R., Filatova, T. , & Hulscher, S. J. M. H. (2021). Reconstruction of the 1374 Rhine river flood event using a 1D-2D hydraulic modelling approach. 39. Abstract from 8th International Conference on Flood Management 2021, Iowa City, Iowa, United States.
Other Contributions

Peer-reviewed journal papers

  • Van der Meulen, B., Bomers, A., Cohen, K. M., Middelkoop, H. (2021). Late Holocene flood dynamics and magnitudes in the Lower Rhine river valley and upper delta resolved by two-dimensional hydraulic modelling approach. Earth Surface Processes and Landforms. DOI: 10.1002/esp.5071 
  • Bomers, A., Van der Meulen, B., Schielen, R. M. J., Hulscher, S. J. M. H. (2019). Historic flood reconstruction with the use of an Artificial Neural Network. Water Resources Research, 55(11), 9673-9688. DOI:10.1029/2019WR025656
  • Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2019). Decreasing uncertainty in flood frequency analyses by including historic flood events in an efficient bootstrap approach. Natural Hazards and Earth System Sciences, 19, 1895-1908. DOI: 10.5194/nhess-19-1895-2019
  • Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2019). Consequences of dike breaches and dike overflow in a bifurcating river system. Natural Hazards, 97, 309-443. DOI: 10.1007/s11069-019-03643-y
  • Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2019). Application of a lower-fidelity surrogate  hydraulic model for historic flood reconstruction. Environmental Modelling and Software, 117, 223-236. DOI:10.1016/j.envsoft.2019.03.019                                                                 
  • Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2019). The influence of grid shape and grid size on hydraulic river modelling performance. Environmental Fluid Mechanics, 19, 1273-1294. DOI: 10.1007/s10652-019-09670-4
  • Aguilar-Lopez, J. P., Warmink, J. J., Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2018) Failure of grass covered flood defences with roads on top due to wave overtopping: A probabilistic assessment method. Journal of Marine Science and Engineering, 6(3), 74. DOI: 10.3390/jmse6030074    
  • Bomers, A., Aguilar-Lopez, J. P., Warmink, J. J., Hulscher, S. J. M. H. (2018) Modelling effects of an asphalt road at a dike crest on dike cover erosion onset during wave overtopping. Natural hazards, 93(1), 1-30. DOI: 10.1007/s11069-018-3287-y        

 

Dissertation

  • Bomers, A. (2020) Hydraulic modelling approaches to decrease uncertainty in flood frequency relations. PhD thesis, University of Twente, the Netherlands. ISBN 978-90-365-4928-8. DOI:10.3990/1.9789036549288 (to receive a hardcopy, please contact me)


Conference papers

  • Bomers. A., Balmes, J. P., Fernandez, T., Schnauder, I. (2020) Numerical and experimental programme on flow around horizontal cylinders as large wood prototypes. Abstract for the 6th‑ IAHR Europe Congress, Warsaw, Poland (accepted)
  • Bomers, A., Booij, D.G.R., Paarlberg, A., Huthoff, F., Borsje, B. W. (2020) The effect of a constant hydraulic roughness on the migration of mid-channel bars. Abstract from NCR days 2020, Nijmegen, The Netherlands.
  • Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2019). The severe 1374 Rhine river flood event in present times. Water – connecting the world: Proceedings of the 38th IAHR World Congress, Panama city, Panama. DOI:10.3850/38WC092019-0501
  • Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2019). The effect of dike breaches on downstream discharge partitioning. 28. Abstract from NCR Days 2019: Land of Rivers, Utrecht, The Netherlands.
  • Bomers, A., Hulscher, S. J. M. H., Lammersen, R., Schielen, R. M. J. (2018). The effect of dike breaches on downstream discharge partitioning near a river bifurcation. In A. Armanini, E. Nucci (Eds.), New Challenges in Hydraulic Research and Engineering: Proceedings of the 5th IAHR Europe Congress (pp.  805-806). Research Publishing. DOI: 10.3850/978-981-11-2731-1070-cd
  • Warmink, J. J., van Bergeijk, V. M., Chen, W., Aguilar-Lopez, J. P., Bomers, A., Hulscher, S. J. M. H. (2018) Modelling wave overtopping for flood defense reliability. 3rd international Conference on Protection against Overtopping, 6-8 June 2018, UK.
  • Van der Meulen, B., Deggeller, T. S., Bomers,  A., Cohen, K. M., Middelkoop, H. (2018). The historical river: morphology of the Rhine before river normalization. 44-45. Abstract from NCR Days 2018, Delft, The Netherlands.
  • Bomers,  A.,  Schielen,  R.  M.  J.,  Hulscher,  S.  J.  M.  H.  (2018).   Flood  patterns in the Old IJssel Valley.  126-127.  Abstract from NCR Days 2018, Delft, The Netherlands.
  • Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2017). Benchmark  study of numerical model grids to study historic floods of the river Rhine. 1-3. Abstract from 4th International  Symposium on Shallow Flows, ISSF 2017, Eindhoven, The Netherlands.
  • Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2017). Modelling historic floods to validate present and future design discharges:  the 1926 case.  68-69. Abstract from NCR Days 2017, Wageningen, The Netherlands.
  • Bomers, A., Aguilar-Lopez, J. P., Warmink, J. J., Hulscher, S. J. M. H. (2016) Erosion development during wave overtopping of an asphalt road covered dike. In M. Lang, F. Klijn & P. Samuels (Eds.), FLOODrisk 2016: 3rd European Conference on Flood Risk Management 17-21 October 2016, Lyon, France (pp. 1-8; Vol. 7), E3S Web of Conferences. DOI: 10.1051/e3sconf/20160703003
  • Cohen,  K.M.,  Schielen,  R., van der Meulen, B., Bomers,  A.,  Hulscher, S. J. M. H., Middelkoop, H. (2016).  Floods of the Past, Design of Tomorrow - Project Introduction.  In:  Fontana, A., Rossata, S. (Eds.), Abstract Volume Ex-Aqua 2016 Palaeohydrological Extreme Events:  Evidence and Archives.  Università degli Studi di Padova, Padova, Italy
  • Schielen, R. M. J., Bomers, A., Kroekenstoel, D. (2014) Unraveling the contributions of wind, sea level and discharge to design water levels in the Dutch delta. Proc. 7th River Flow Congress, Lausanne, Switzerland, pp. 1729-1736.


Other contributions

  • Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2020) Reply to "Consequences of dike breaches and dike over flow in a bifurcating river system". Natural Hazards. DOI:10.1007/s11069-020-04162-x
  • Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2019). Verkleinen van de onzekerheid in huidig waterbeleid met historische overstromingen. H20-online
  • Bomers, A., Van der Meulen, B. (2019). Reconstructed data on the 1809 historic flood event of the Rhine river. 4TU.Centre for Research Data, 5 Nov 2019. DOI:10.4121/uuid:2068ddc3-1726-4d9d-bbe7-37477767b330.
  • Bomers, A., Schielen, R. M. J., Hulscher, S. J. M. H. (2019). Decreasing uncertainty in flood  frequency  analyses by including historic flood events in an efficient bootstrap approach. Natural Hazards and  Earth System Sciences Discussion. DOI:10.5194/nhess-2019-83
  • Bomers, A., Aguilar-Lopez, J. P., Warmink, J. J., Hulscher, S. J. M. H. (2017) Invloed van een weg op dijkerosie tijdens golfoverslag. H20, 1-8
  • Bomers, A. (2016). Historische overstromingen - ontwerp voor de toekomst. ConcepTueel, 25(2), 1-4

 

 

UT Research Information System

Google Scholar Link

Education

Courses Bachelor Civil Engineering:

  • Design project Civil Engineering, Bsc level, 2016-now
    Tutor and mentor

Courses Master Civil Engineering and Management:

  • Hydraulic modelling, Msc level, 5 EC.
    Set up of course: coordination, arranging guest lectures, designing exercises, assignments, examination and grading.
  • River Dynamics, Msc level, 7.5 EC, 2017-2019
    Supervising the tutorials
  • Design Project Water, MSc level, 7.5 EC, 2015-2019
    Responsible for modelling part of the course

Supervision of Bsc graduation  project:

  • R. den Hertog, 2021: De Chaamse Beken in Tygron
  • J. Bod, 2021: Spreading of the runoff times in the Dutch Rhine delta
  • S.A. de Vreeze, 2018: Hoogwaterverwachtingen op de Overijsselse Vecht
  • J. Willink, 2017: Process change analysis at waterboard Rijn & IJssel
  • R. de Boer, 2016: The effect of retaining water extremes in nature areas on water policy

Supervision of Msc graduation  project:

  • L. Leummens, 2021: Sensitivity of channel-size estimations on flood inundations
  • M. Flohr, 2021: Improvement of rainfall-runoff simulations on urban unpaved surfaces
  • S.E. Overmeen, 2021: Determining the wind drag coefficient in hydrodynamic modelling of a shallow, fetch-limited water system
  • R.A.H. Kilsdonk, 2021: Predicting flooding due to extreme precipitation in an urban environment using machine learning algorithms
  • E. Bilgili, 2020: The influence of a grid structure on hydraulic river modelling outcomes of river meanders
  • R. Dierx, 2020: Modelling breach erosion of cover sand ridges in the IJssel floodplain induced by water overflow in early medieval times
  • D. Booij, 2020: Morphodynamic modelling of migrating mid-channel bars in rivers using dynamic vegetation. A case study of the Ayeyarwady River
  • J.J.M. Thissen, 2019: Automating surface water detection for rivers
  • Y. Fredrix, 2018: Exploring the use of surrogate models to reconstruct historic discharges


 

Affiliated Study Programmes

Bachelor

Master

Courses Academic Year  2021/2022

Courses in the current academic year are added at the moment they are finalised in the Osiris system. Therefore it is possible that the list is not yet complete for the whole academic year.
 

Courses Academic Year  2020/2021

Projects

Floods of the past - Design for the future

Design standards for flood protection in deltas require magnitude estimates of extreme (millennial) floods. The Dutch Delta Programme considers a design discharge of 18,000 m3/s an appropriate upper value the Rhine River at the German-Dutch border. Absence of a sufficiently long observational record of river discharge introduces considerable uncertainty in estimates of magnitude-frequency relations, which can only partly be solved by using statistical methods.  To solve this problem, this project focusses on the extension of the data set of observed discharges by reconstructing historic flood events using novel hydraulic modelling approaches.

  • 2020-now: Daily supervisor of Hieu Ngo (PostDoc project). This project focusses on the reconstruction of the 1374 flood event of the Rhine river representing the largest flood of the last 1,000 years. Furthermore, this project evaluates the social impacts of such a large flood event in present times based on sophisticated Agent-Based modelling. The project is a collaboration between the MFS and BMS groups of the University of Twente, Utrecht University and IHE Delft.
  • 2015-2020: PhD candidate. I established efficient modelling approaches to be able to reconstruct historic flood events. Both the suitability of lower-fidelity physically based surrogate models as data driven surrogate models have been evaluated. This project was finalised by extending the data set of measured discharges starting in 1900 with approximately 600 years. This project is a collaboration between the University of Twente and Utrecht University.

 

 

Large Wood Hydraulic (LaWoHy)

  • 2019-now: Researcher. This project focusses on the effect of large wood in rivers on the flow patterns and turbulence characteristics. The project is a collaboration between Vienna Technical University (TU Wien) and the University of Twente. TU Wien performs flume experiments delivering valuable measurements regarding changes in flow velocities and turbulent kinetic energies caused by the obstacles in the flow. It is my task to model these flume experiments using the opensource numerical software OpenFoam. Various turbulence models are compared to help practitioners waith making appropriate modelling choices.

 

 

Adaptive calibration approaches for hydraulic river models to link high flow and low flow conditions

  • 2021-now: Much research has been done on the calibration of maximum water levels during flood events to design flood mitigation measures. However, up till now, low flow conditions did not have much research interest while it may have serious economic consequences if water levels in a river are below the navigable depth. The development of river dunes are one of the main drivers of the river water levels during low flow. Therefore, this study tries to set up a novel calibration method such that both high and low flow conditions can be simulated accurately by improving, among others, the description of the main channel bed roughness based on the physical properties of river dunes.

 

River dune dynamics under high and low flows

  • 2020-now: Co-supervisor of Lieke R. Lokin (PhD project). River dunes are dynamic periodic bedforms at the riverbed, which are formed by flow over a movable riverbed. These river dunes are present in all alluvial rivers, such as the Rhine, the Mississippi and the Amazon river. During flood waves these river dunes grow in length and height and during low water levels they decay. Currently we do not know how the growth and decay processes of river dunes work exactly and therefore we are unable to predict their development. Understanding the processes that play a role in the evolution of these river dunes and being able to model them, helps river managers to predict bed form dynamics. It helps them to plan dredging measures before dunes become obstacles during low water levels. As during low water, the highest dune determines the navigable depth. This research aims to better understand and model the dynamics of river dunes under variable flow conditions, to predict river dune dynamics several days to weeks ahead. 

 

Others

  • Organizer of the NCR-days 2021 conference, Enschede
  • Reviewer for e.g. the following journals: Nature, Computers & Geosciences (CAGEO), Water, journal of Hydrology, Ecohydrology, Journal of Flood Risk Management

Contact Details

Visiting Address

University of Twente
Faculty of Engineering Technology
Horst Complex (building no. 20), room W219
De Horst 2
7522LW  Enschede
The Netherlands

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Mailing Address

University of Twente
Faculty of Engineering Technology
Horst Complex  W219
P.O. Box 217
7500 AE Enschede
The Netherlands