Measuring and modelling over wash hydrodynamics on a barrier island

Ana Matias, Ana Rita Carrasco, Carlos Loureiro, Umberto Andriolo, Gerd Masselink, Martha Guerreiro, Andre Pacheco, Robert McCall, Oscar Ferreira, Theocharis Plomaritis

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

Overwash hydrodynamics datasets are mixed in quality and scope, being hard to obtain due to fieldwork experimental difficulties. Aiming to overcome such limitations, this work presents accurate fieldwork data on overwash hydrodynamics, further exploring it to model overwash on a low-lying barrier island. Fieldwork was performed on Barreta Island (Portugal), in December 2013, during neap to spring-tides, when significant wave height reached 2.64 m. During approximately 4 hours, more than 120 shallow overwash events were measured with a video-camera (at 10 Hz), a pressure transducer (at 4 Hz) and a current-meter (at 4 Hz). This high-frequency fieldwork dataset includes runup, overwash number, depth and velocity. Fieldwork data along with information from literature were used to setup XBeach model in non-hydrostatic mode. The baseline model had variable skills over the duration of the overwash episode, performing better during the rising tide than during the falling tide. Model average number of events RMSE (root-mean-square-error) was 7 events each 30 minutes. The baseline model was forced to simulate overwash with different nearshore morphology, grain-size and lagoon water level. An average decrease of about 30% overwash was obtained due to changes in the nearshore morphology, mostly a small vertical growth of the submerged bar. The coarser and finer grain-sizes tests produced an 11% change in overwash, with less overwash on the coarser barrier. Changing lagoon water levels had a reduced effect on overwash hydraulics.
LanguageEnglish
Title of host publicationProceedings of Coastal Dynamics 2017
EditorsTroels Aagaard, Rolf Deigaard, David Fuhrman
Place of PublicationHelsingor
Pages1616-1627
Volume1
Publication statusPublished - 12 Jun 2017

Fingerprint

barrier island
fieldwork
hydrodynamics
tide
modeling
lagoon
water level
grain size
significant wave height
transducer
measuring
hydraulics

Keywords

  • storm impacts
  • hydrodynamics
  • XBeach
  • runup
  • nearshore topography
  • video data

Cite this

Matias, A., Carrasco, A. R., Loureiro, C., Andriolo, U., Masselink, G., Guerreiro, M., ... Plomaritis, T. (2017). Measuring and modelling over wash hydrodynamics on a barrier island. In T. Aagaard, R. Deigaard, & D. Fuhrman (Eds.), Proceedings of Coastal Dynamics 2017 (Vol. 1, pp. 1616-1627). Helsingor.
Matias, Ana ; Carrasco, Ana Rita ; Loureiro, Carlos ; Andriolo, Umberto ; Masselink, Gerd ; Guerreiro, Martha ; Pacheco, Andre ; McCall, Robert ; Ferreira, Oscar ; Plomaritis, Theocharis. / Measuring and modelling over wash hydrodynamics on a barrier island. Proceedings of Coastal Dynamics 2017. editor / Troels Aagaard ; Rolf Deigaard ; David Fuhrman. Vol. 1 Helsingor, 2017. pp. 1616-1627
@inbook{15306bb9e7b84a3db659835c2ef5b1db,
title = "Measuring and modelling over wash hydrodynamics on a barrier island",
abstract = "Overwash hydrodynamics datasets are mixed in quality and scope, being hard to obtain due to fieldwork experimental difficulties. Aiming to overcome such limitations, this work presents accurate fieldwork data on overwash hydrodynamics, further exploring it to model overwash on a low-lying barrier island. Fieldwork was performed on Barreta Island (Portugal), in December 2013, during neap to spring-tides, when significant wave height reached 2.64 m. During approximately 4 hours, more than 120 shallow overwash events were measured with a video-camera (at 10 Hz), a pressure transducer (at 4 Hz) and a current-meter (at 4 Hz). This high-frequency fieldwork dataset includes runup, overwash number, depth and velocity. Fieldwork data along with information from literature were used to setup XBeach model in non-hydrostatic mode. The baseline model had variable skills over the duration of the overwash episode, performing better during the rising tide than during the falling tide. Model average number of events RMSE (root-mean-square-error) was 7 events each 30 minutes. The baseline model was forced to simulate overwash with different nearshore morphology, grain-size and lagoon water level. An average decrease of about 30{\%} overwash was obtained due to changes in the nearshore morphology, mostly a small vertical growth of the submerged bar. The coarser and finer grain-sizes tests produced an 11{\%} change in overwash, with less overwash on the coarser barrier. Changing lagoon water levels had a reduced effect on overwash hydraulics.",
keywords = "storm impacts, hydrodynamics, XBeach, runup, nearshore topography, video data",
author = "Ana Matias and Carrasco, {Ana Rita} and Carlos Loureiro and Umberto Andriolo and Gerd Masselink and Martha Guerreiro and Andre Pacheco and Robert McCall and Oscar Ferreira and Theocharis Plomaritis",
year = "2017",
month = "6",
day = "12",
language = "English",
isbn = "n/a",
volume = "1",
pages = "1616--1627",
editor = "Troels Aagaard and Rolf Deigaard and David Fuhrman",
booktitle = "Proceedings of Coastal Dynamics 2017",

}

Matias, A, Carrasco, AR, Loureiro, C, Andriolo, U, Masselink, G, Guerreiro, M, Pacheco, A, McCall, R, Ferreira, O & Plomaritis, T 2017, Measuring and modelling over wash hydrodynamics on a barrier island. in T Aagaard, R Deigaard & D Fuhrman (eds), Proceedings of Coastal Dynamics 2017. vol. 1, Helsingor, pp. 1616-1627.

Measuring and modelling over wash hydrodynamics on a barrier island. / Matias, Ana; Carrasco, Ana Rita; Loureiro, Carlos; Andriolo, Umberto; Masselink, Gerd; Guerreiro, Martha; Pacheco, Andre; McCall, Robert; Ferreira, Oscar; Plomaritis, Theocharis.

Proceedings of Coastal Dynamics 2017. ed. / Troels Aagaard; Rolf Deigaard; David Fuhrman. Vol. 1 Helsingor, 2017. p. 1616-1627.

Research output: Chapter in Book/Report/Conference proceedingChapter

TY - CHAP

T1 - Measuring and modelling over wash hydrodynamics on a barrier island

AU - Matias, Ana

AU - Carrasco, Ana Rita

AU - Loureiro, Carlos

AU - Andriolo, Umberto

AU - Masselink, Gerd

AU - Guerreiro, Martha

AU - Pacheco, Andre

AU - McCall, Robert

AU - Ferreira, Oscar

AU - Plomaritis, Theocharis

PY - 2017/6/12

Y1 - 2017/6/12

N2 - Overwash hydrodynamics datasets are mixed in quality and scope, being hard to obtain due to fieldwork experimental difficulties. Aiming to overcome such limitations, this work presents accurate fieldwork data on overwash hydrodynamics, further exploring it to model overwash on a low-lying barrier island. Fieldwork was performed on Barreta Island (Portugal), in December 2013, during neap to spring-tides, when significant wave height reached 2.64 m. During approximately 4 hours, more than 120 shallow overwash events were measured with a video-camera (at 10 Hz), a pressure transducer (at 4 Hz) and a current-meter (at 4 Hz). This high-frequency fieldwork dataset includes runup, overwash number, depth and velocity. Fieldwork data along with information from literature were used to setup XBeach model in non-hydrostatic mode. The baseline model had variable skills over the duration of the overwash episode, performing better during the rising tide than during the falling tide. Model average number of events RMSE (root-mean-square-error) was 7 events each 30 minutes. The baseline model was forced to simulate overwash with different nearshore morphology, grain-size and lagoon water level. An average decrease of about 30% overwash was obtained due to changes in the nearshore morphology, mostly a small vertical growth of the submerged bar. The coarser and finer grain-sizes tests produced an 11% change in overwash, with less overwash on the coarser barrier. Changing lagoon water levels had a reduced effect on overwash hydraulics.

AB - Overwash hydrodynamics datasets are mixed in quality and scope, being hard to obtain due to fieldwork experimental difficulties. Aiming to overcome such limitations, this work presents accurate fieldwork data on overwash hydrodynamics, further exploring it to model overwash on a low-lying barrier island. Fieldwork was performed on Barreta Island (Portugal), in December 2013, during neap to spring-tides, when significant wave height reached 2.64 m. During approximately 4 hours, more than 120 shallow overwash events were measured with a video-camera (at 10 Hz), a pressure transducer (at 4 Hz) and a current-meter (at 4 Hz). This high-frequency fieldwork dataset includes runup, overwash number, depth and velocity. Fieldwork data along with information from literature were used to setup XBeach model in non-hydrostatic mode. The baseline model had variable skills over the duration of the overwash episode, performing better during the rising tide than during the falling tide. Model average number of events RMSE (root-mean-square-error) was 7 events each 30 minutes. The baseline model was forced to simulate overwash with different nearshore morphology, grain-size and lagoon water level. An average decrease of about 30% overwash was obtained due to changes in the nearshore morphology, mostly a small vertical growth of the submerged bar. The coarser and finer grain-sizes tests produced an 11% change in overwash, with less overwash on the coarser barrier. Changing lagoon water levels had a reduced effect on overwash hydraulics.

KW - storm impacts

KW - hydrodynamics

KW - XBeach

KW - runup

KW - nearshore topography

KW - video data

M3 - Chapter

SN - n/a

VL - 1

SP - 1616

EP - 1627

BT - Proceedings of Coastal Dynamics 2017

A2 - Aagaard, Troels

A2 - Deigaard, Rolf

A2 - Fuhrman, David

CY - Helsingor

ER -

Matias A, Carrasco AR, Loureiro C, Andriolo U, Masselink G, Guerreiro M et al. Measuring and modelling over wash hydrodynamics on a barrier island. In Aagaard T, Deigaard R, Fuhrman D, editors, Proceedings of Coastal Dynamics 2017. Vol. 1. Helsingor. 2017. p. 1616-1627