Next Article in Journal
Effects of Swell on Wave Height Distribution of Energy-Conserved Bimodal Seas
Previous Article in Journal
Understanding Hurricane Storm Surge Generation and Propagation Using a Forecasting Model, Forecast Advisories and Best Track in a Wind Model, and Observed Data—Case Study Hurricane Rita
Previous Article in Special Issue
Mesoscale Morphological Changes of Nearshore Sand Banks since the Early 19th Century, and Their Influence on Coastal Dynamics, Northern France
Open AccessArticle

Morphodynamic Acceleration Techniques for Multi-Timescale Predictions of Complex Sandy Interventions

1
Faculty of Civil Engineering and Geosciences, Department of Hydraulic Engineering, Delft University of Technology, P.O. Box 5048, 2600 GA Delft, The Netherlands
2
Deltares, Unit Hydraulic Engineering, PO Box 177, 2600 MH Delft, The Netherlands
3
IHE Delft, Institute for Water Education, Department of Water Science and Engineering, P.O. Box 3015, 2601 DA Delft, The Netherlands
4
Water Engineering and Management, Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
*
Author to whom correspondence should be addressed.
J. Mar. Sci. Eng. 2019, 7(3), 78; https://doi.org/10.3390/jmse7030078
Received: 14 February 2019 / Revised: 12 March 2019 / Accepted: 16 March 2019 / Published: 21 March 2019
(This article belongs to the Special Issue Large-scale Coastal Behavior)
  |  
PDF [15421 KB, uploaded 28 March 2019]
  |  

Abstract

Thirty one percent (31%) of the world’s coastline consists of sandy beaches and dunes that form a natural defense protecting the hinterland from flooding. A common measure to mitigate erosion along sandy beaches is the implementation of sand nourishments. The design and acceptance of such a mitigating measure require information on the expected evolution at time scales from storms to decades. Process-based morphodynamic models are increasingly applied, together with morphodynamic acceleration techniques, to obtain detailed information on this wide scale of ranges. This study shows that techniques for the acceleration of the morphological evolution can have a significant impact on the simulated evolution and dispersion of sandy interventions. A calibrated Delft3D model of the Sand Engine mega-nourishment is applied to compare different acceleration techniques, focusing on accuracy and computational times. Results show that acceleration techniques using representative (schematized) wave conditions are not capable of accurately reproducing the morphological response in the first two years. The best reproduction of the morphological behavior of the first five years is obtained by the brute force simulations. Applying input filtering and a compression factor provides similar accuracy yet with a factor five gain in computational cost. An attractive method for the medium to long time scales, which further reduces computational costs, is a method that uses representative wave conditions based on gross longshore transports, while showing similar results as the benchmark simulation. Erosional behavior is captured well in all considered techniques with variations in volumes of about 1 million m 3 after three decades. The spatio-temporal variability of the predicted alongshore and cross-shore distribution of the morphological evolution however have a strong dependency on the selected acceleration technique. A new technique, called ’brute force merged’, which incorporates the full variability of the wave climate, provides the optimal combination of phenomenological accuracy and computational efficiency (a factor of 20 faster than the benchmark brute force technique) at both the short and medium to long time scales. This approach, which combines realistic time series and the mormerge technique, provides an attractive and flexible method to efficiently predict the evolution of complex sandy interventions at time scales from hours to decades. View Full-Text
Keywords: morphodynamic modelling; nourishments; acceleration techniques; long-term evolution; Delft3D; coastal behavior morphodynamic modelling; nourishments; acceleration techniques; long-term evolution; Delft3D; coastal behavior
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Luijendijk, A.P.; de Schipper, M.A.; Ranasinghe, R. Morphodynamic Acceleration Techniques for Multi-Timescale Predictions of Complex Sandy Interventions. J. Mar. Sci. Eng. 2019, 7, 78.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
J. Mar. Sci. Eng. EISSN 2077-1312 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top