Flood Hazard Assessment for a Hyper-Tidal Estuary as a Function of Tide-Surge-Morphology Interaction

Lyddon, Charlotte ORCID: 0000-0003-4254-3049, Brown, Jennifer M, Leonardi, Nicoletta and Plater, Andrew J ORCID: 0000-0001-7043-227X (2018) Flood Hazard Assessment for a Hyper-Tidal Estuary as a Function of Tide-Surge-Morphology Interaction. ESTUARIES AND COASTS, 41 (6). pp. 1565-1586.

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Abstract

Astronomical high tides and meteorological storm surges present a combined flood hazard to communities and infrastructure. There is a need to incorporate the impact of tide-surge interaction and the spatial and temporal variability of the combined flood hazard in flood risk assessments, especially in hyper-tidal estuaries where the consequences of tide and storm surge concurrence can be catastrophic. Delft3D-FLOW is used to assess up-estuary variability in extreme water levels for a range of historical events of different severity within the Severn Estuary, southwest England as an example. The influence of the following on flood hazard is investigated: (i) event severity, (ii) timing of the peak of a storm surge relative to tidal high water and (iii) the temporal distribution of the storm surge component (here in termed the surge skewness). Results show when modelling a local area event severity is most important control on flood hazard. Tide-surge concurrence increases flood hazard throughout the estuary. Positive surge skewness can result in a greater variability of extreme water levels and residual surge component, the effects of which are magnified up-estuary by estuarine geometry to exacerbate flood hazard. The concepts and methodology shown here can be applied to other estuaries worldwide.

Item Type:	Article
Uncontrolled Keywords:	Flood hazard, Hyper-tidal, Severn estuary, Storm surge, Extreme water level, Delft3D
Depositing User:	Symplectic Admin
Date Deposited:	23 Mar 2018 10:17
Last Modified:	19 Jan 2023 06:38
DOI:	10.1007/s12237-018-0384-9
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3019371