Feasibility study of a coupled numerical model for longshore sediment transport and beach response

Feasibility study of a coupled numerical model for longshore sediment transport and beach response

Zhou, Z.

Stive, M.J.F. (mentor)
Nicholls, R.J. (mentor)
Blanco, B. (mentor)

Civil Engineering and Geosciences

Section Hydraulic Engineering

CoMEM - Coastal and Marine Engineering and Management

2011-06-23

As a good rule of thumb, one-line models have been in use for a wide range of coastal projects for the past 30 years to predict the beach morphological change and make the appropriate shoreline management plans. Though applied to many coastal sites with certain success, these models are still under further development so as to achieve better predictions. Hence, this research aims to extend a state-of-the-art one-line model (BEACHPLAN) in terms of longshore sediment transport rate by linking with a cross-shore profile model (COSMOS) through the OpenMI-based Pipistrelle platform. To couple these two existing models, three additional modules (i.e. Drift Interpolation module, Vector-To-Scalar module and Orientation Updating module) are developed. The existing two models and the three new modules work together as a whole composition (i.e. the coupled model) which aims to improve the one-line model in terms of longshore sediment transport and morphological response predictability. This coupled model calculates the longshore sediment transport rate based on both the modified CERC-formula and the Energetics approach. It is tested at an idealized straight coast and at Poole Bay, UK. This demonstrates that the model is numerically stable, effective in computing and able to give reasonable predictions of the shoreline morphological change. Hence, this dissertation shows that linking the existing models rather than developing completely new models is a potentially interesting research direction that is both economical and feasible to achieve. Some further developments of the model are also suggested. However, it is currently too early to reach the conclusion that the coupled model is better than the original one-line model since few validations have been made due to the limitations of field data and research time. Meanwhile, the working principle behind the coupled model needs further exploration and re-examination before a sound conclusion can be made. Therefore, the outcome of this research at this stage can be more precisely recognized as a proof of concept which demonstrates that it is theoretically reasonable and technically feasible to couple the one-line model and cross-shore profile model so as to realize practitioners’ certain requirements.

Longshore sediment transport
One-line model
Cross-shore profile model
OpenMI standard
Numerical model

http://resolver.tudelft.nl/uuid:8afd36fd-5e6c-4140-a14e-ab23c7aa5646

Student theses

master thesis

(c) 2011 Zhou, Z.