You will be one of the researchers in the OR ELSE project: Operational Recommendations for Ecosystem-based Large-scale Sand Extraction. Recently funded by the Dutch Research Council within the National Science Agenda (NWA-ORC), OR ELSE aims to design solutions that minimize the adverse ecological and societal impacts of large-scale marine sand extraction in the Dutch North Sea and elsewhere. As a whole, OR ELSE consists of ten interlinked work packages involving a total of six PhD students and four postdocs working at various universities and research institutes in the Netherlands. The work package of this vacancy aims to determine the short-term sedimentological adjustment (several years) as well as the long-term (decadal) biogeomorphological evolution in response to large-scale extraction. It is divided into four stages:

1. Investigate the influence of sand-silt mixtures on the instability behind the formation of tidal sand waves. Adopting an idealized process-based modelling approach, we will set-up of a new 2DV sand wave model in which cohesive sediment transport processes (such as flocculation) are parametrically included. A linear stability analysis then reveals (i) possible shifts in the border between stability and instability, (ii) changes in the preferred sand wave mode (wavelength, migration rate, formation time scale of the fastest growing mode), and (iii) the underlying physical mechanisms.
2. Extend from sand wave patterns to large-scale sand extraction pits (on the spatial scale of an individual sand wave or longer). Here we aim to make the step from infinitesimally small yet spatially unconfined sand wave patterns (see step 1 above) to spatially confined sand extraction pits. This will be done in two ways: (i) analyzing the superposition of various modes in step 1 (still using an idealized model) and (ii) setting up a Delft3D model that accounts for cohesive transport processes in and around sand pits. Specific focus on the way silt dynamics affects the morphological evolution of the pit.
3. Include benthos in the above analysis. We will extend the Delft3D model from step 2 in order to include ecosystem engineering species. Therefore we will link their activity to physical properties of the seabed and study the biogeomorphological evolution of the pit. We will select a maximum of three ecosystem engineering species on the basis of (i) their abundance in and around sandpits, (ii) their strong modification of the environment, and (iii) their contrasting type of feeding and burrowing, and thereby contrasting influence on the sediment dynamics and hydrodynamics.
4. As a final step, we aim to actually apply the above models to aid the spatiotemporal design of large-scale sand extraction activities, i.e. on the spatial scale of tidal sand waves. Specific focus on the interaction with benthos.

Being part of our OR ELSE consortium implies close interaction with your direct supervisors at UT and your fellow researchers of the other work packages. The link to practice is warranted by recurring user group meetings with professionals from the Netherlands, as well as a group of international experts. Furthermore, you will present your work at national and international conferences and write your findings in journal papers and a PhD thesis to be defended at the end of your project.

• MSc in Civil Engineering, Physics, Applied Mathematics or related discipline.
• You have sound skills in (or are highly motivated to quickly learn these):
• Numerics and programming (e.g. Python, Matlab)
• Physical processes of marine morphology
• Theoretical aspects of mathematical modelling (PDEs, asymptotic solutions)
• Data-analysis and hydraulic modelling software (e.g. Delft3D).
• Your organizational skills are good. You are enthusiastic, independent and have a problem-solving attitude.
• You are willing to contribute to the Civil Engineering BSc and Msc programs by assisting in the teaching of courses and by supervising graduate students.
• Your writing skills are good - you have experience in writing technical and/or scientific reports.
• You are fluent in English, both spoken and written (IELTS 6.5 or equivalent).

What we offer is a highly challenging position in an inspiring multidisciplinary environment with enthusiastic colleagues.

• Four-year fulltime PhD position, with a qualifier exam after 6-9 months.
• Full status as an employee at the UT, including pension and health care benefits
• A stimulating, modern research environment with world-class research facilities.
• Tailor-made educational/development program of at least 6 months (30EC), including visits to conferences.
• Excellent mentorship and a stimulating research environment to accelerate your further professional and personal growth.
• A starting salary of € 2541,- gross per month in the first year and increasing to € 3247,- gross per month in the fourth year.
• An annual holiday allowance of 8% of the gross annual salary, and an annual year-end bonus of 8.3%.
• The University of Twente is situated on a green and lively campus with lots of facilities for sports and other activities.
• From you, we expect willingness to move to (the vicinity of) Enschede. A relocation allowance or temporary housing allowance may be part of the offer.

While your first responsibility is to carry out the research, you will also acquire teaching experience (about 10% of your time). We support you to broaden your knowledge by joining international exchange programs, by participating in national and international conferences and workshops and by visiting industrial companies, research institutes, and universities worldwide.