Introduction :
Many coasts around the world are under threat of erosion due to storms and slow but progressive retreat by sea level rise. Predictions of future climate change impacts and the effective implementation of coastal structures are essential to help coastal communities deal with this challenge. However, the existing coastal models are either too slow for the evaluation of climate change scenarios (only to be used for years at km scale regions) or they are not capable of dealing with complex coastal structures (e.g. groynes and offshore breakwaters) and dune interactions. The gap has to be bridged in order to be able to provide a good quantitative estimate of the coastal maintenance effort that will be needed in the coming decades. The ‘ShorelineS’ TKI programme is aimed at creating a validated and easy to apply model which deals efficiently with the upcoming societal questions.
The ShorelineS model is currently used as a research tool aimed at finding the driving mechanisms for complex coastal areas. It has, for example, been used to evaluate 1) the complex coastline development at the Sand Motor, 2) salient development at an offshore breakwater, 3) the evaluation of the coastline of St. Louis (Senegal) and 4) the growth of a spit in Angola. The ShorelineS model is already capable of performing many tasks but a next step is needed to bring it to the level of a verified engineering software tool, similar to the Xbeach model. Thorough testing, version control and application to field cases are needed to obtain a robust engineering model. It is our aim to develop the model further keeping with the aim of achieving the following within the TKI ShorelineS:
- A quick and easy to apply model (saves time to setup and run)
- Computationally efficient
- Handles complex coastlines (even with spit features), which enhances applicability
- Has the ability to deal with the effects of nourishments and coastal structures at decadal time-scales
- will provide sufficiently accurate coastline predictions to make a judgment between design alternatives (of coastal measures)
Other models, such as Xbeach, will still be useful, but are used for shorter term predictions (hours to years) for smaller areas (i.e. up to km-scale). The ShorelineS model overcomes the difficulties (e.g. too long run-time) that Xbeach (and similar ‘field’ models) face when making long-term evaluations and impact assessments of coastal structures.
The ShorelineS model is going to be very relevant for coastal engineering in the near future, and essential assessment tool next to the complex models.
Consortium :
The community building with the consortium is considered an essential aspect which will inspire new developments and may form a start for further knowledge exchange. The consortium consists of:
- Initiators : Stichting Deltares, IHE-Delft
- Consultancy firms : Ingenieursbureau Svašek, CDR-international, Arcadis, Royal Haskoning-DHV, IMDC, EGIS water & Maritime, Sweco Sverige, JBA Pacific, Tonkin & Taylor
- Dredgers : Baggermaatschappij Boskalis, Van Oord, Dredging International, Jan de Nul
- International research institutes : Flanders Hydraulics Research, Kuwait Institute for Scientific Research
Scope :
This project aims at developing knowledge for efficient modelling of (measures on) sandy coasts on yearly to decadal time scales. Accounting also for complex coastal structures and cross-shore interactions with the middle shoreface and dunes. This knowledge is necessary to be able to evaluate future sediment requirements and management strategies for sandy coasts. The following scope was defined on the basis of the priorities of the partners:
- Task 1 Efficient wave, current and climate conditions
Wave data, tide conditions and sea level rise conditions are implemented in such a way that the number of complex modelling decisions is reduced. - Task 2 Coastal structures and sand nourishments
Complex coastal features, such as groynes, offshore breakwaters, rocky headlands and nourishments are researched and implemented, which is essential for assessments in densely populated metropolitan coastal areas. - Task 3 Cross-shore transport to dunes and middle shoreface & sediment availability
The dunes and middle shoreface act as buffers of sediment. The exchange is essential for the assessment of long-term decadal coastal response. - Task 4 Efficient code & mathematical techniques
Improved efficiency of the code through optimization of the structure and language. - Task 5 Automatic verification methodology
Creation of robust code through a testbed and version control. - Task 6 Pilot model applications
Case studies showcasing the potential use of the ShorelineS model. Case studies are used as a basis for the testbed. Pre- and postprocessing routines are made.
Planning :
The project starts in H1 2022 with a kick-off meeting. And then the program will run for 2 years. Half-yearly meetings will be planned to discuss the scope for the next period. Sub-groups are organized to discuss and cooperate on the the development of the tasks 1 to 6 and their sub-tasks. The planning is as follows:
- 2022-may Kick-off meeting : first period is used for setting up demonstration case, detailing of scope with participants, capactity building and code improvements
- 2022-oct Half-yearly progress meeting #1 : this phase is the start of the developments and participants make first case studies
- 2023-may Half-yearly progress meeting #2 : developments are tested and case studies finalized
- 2023-oct Half-yearly progress meeting #3 : research reports are written and evaluations are made of the developments and code
- 2024-may End meeting : Delivery of the final products
Products :
The official products of this TKI programme are:
- Knowledge on the tasks T1 to T3 which will be dissimenated in research reports
- Software code development of the ShorelineS model
- A testbed which can be used for version control
- Capacity building for participants
The research reports and software code developments are shared under an open license after the project has ended (in 2024).
