Evaluation of wave runup predictions from numerical and parametric models

Wave runup during storms is a primary driver of coastal evolution, including shoreline and dune erosion and barrier island overwash. Runup and its components, setup and swash, can be predicted from a parameterized model that was developed by comparing runup observations to offshore wave height, wave...

Full description

Saved in:

Bibliographic Details
Published in:	Coastal engineering (Amsterdam) Vol. 92; pp. 1 - 11
Main Authors:	Stockdon, H.F., Thompson, D.M., Plant, N.G., Long, J.W.
Format:	Journal Article
Language:	English
Published:	Kidlington Elsevier B.V 01-10-2014 Elsevier
Subjects:	Accuracy Coastal oceanography, estuaries. Regional oceanography Computer simulation Earth, ocean, space Errors Exact sciences and technology External geophysics Extreme values Mathematical models Observations Parametrization Physics of the oceans Runup Setup Slopes Storms Swash XBeach North Carolina United States XBeach Storms Swash Runup Setup Observations Performance evaluation Littoral zone shorelines digital simulation Forecast model North America Wave breaking parametrization hurricanes Severe weather Tropical cyclone Observation data Storm surge Risk management Breaking zone Infragravity wave
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Wave runup during storms is a primary driver of coastal evolution, including shoreline and dune erosion and barrier island overwash. Runup and its components, setup and swash, can be predicted from a parameterized model that was developed by comparing runup observations to offshore wave height, wave period, and local beach slope. Because observations during extreme storms are often unavailable, a numerical model is used to simulate the storm-driven runup to compare to the parameterized model and then develop an approach to improve the accuracy of the parameterization. Numerically simulated and parameterized runup were compared to observations to evaluate model accuracies. The analysis demonstrated that setup was accurately predicted by both the parameterized model and numerical simulations. Infragravity swash heights were most accurately predicted by the parameterized model. The numerical model suffered from bias and gain errors that depended on whether a one-dimensional or two-dimensional spatial domain was used. Nonetheless, all of the predictions were significantly correlated to the observations, implying that the systematic errors can be corrected. The numerical simulations did not resolve the incident-band swash motions, as expected, and the parameterized model performed best at predicting incident-band swash heights. An assimilated prediction using a weighted average of the parameterized model and the numerical simulations resulted in a reduction in prediction error variance. Finally, the numerical simulations were extended to include storm conditions that have not been previously observed. These results indicated that the parameterized predictions of setup may need modification for extreme conditions; numerical simulations can be used to extend the validity of the parameterized predictions of infragravity swash; and numerical simulations systematically underpredict incident swash, which is relatively unimportant under extreme conditions. •XBeach simulated wave setup and infragravity swash compared well to observations.•One-dimensional XBeach runs were more accurate than those in two dimensions.•Incident swash was most accurately predicted using the parametric model.•Assimilation of the numerical and parametric models improved overall accuracy.•XBeach infragravity swash during hurricanes compared well with parameterized values.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0378-3839 1872-7379
DOI:	10.1016/j.coastaleng.2014.06.004