Reassessing flood frequency for the Sussex Ouse, Lewes: the inclusion of historical flood information since AD 1650

Macdonald, N.; Kjeldsen, T.R.; Prosdocimi, I.; Sangster, H.. 2014 Reassessing flood frequency for the Sussex Ouse, Lewes: the inclusion of historical flood information since AD 1650. Natural Hazards and Earth System Sciences, 14 (10). 2817-2828. https://doi.org/10.5194/nhess-14-2817-2014

Before downloading, please read NORA policies.

Preview

Text N508959JA.pdf - Published Version Available under License Creative Commons Attribution. Download (1MB) | Preview

Abstract/Summary

The application of historical flood information as a tool for augmenting instrumental flood data is increasingly recognised as a valuable tool; most previous studies have focused on large catchments with historic settlements, this paper applies the approach to the smaller lowland system of the Sussex Ouse in Southeast England. The reassessment of flood risk on the Sussex Ouse is pertinent in light of severe flooding in October 2000 and heightened concerns of a perceived increase in flooding nationally. Systematic flood level readings from 1960 and accounts detailing past flood events within the catchment are compiled back to c.1750. This extended flood record provides an opportunity to reassess estimates of flood frequency over a timescale not normally possible within flood frequency analysis. This paper re-evaluates flood frequency at Lewes on the Sussex Ouse downstream of the confluence of the Sussex Ouse and River Uck. The paper considers the strengths and weaknesses in estimates resulting from contrasting methods of analysis and their corresponding data: (i) single site analysis of gauged annual maxima; (ii) combined analysis of systematic annual maxima augmented with historical peaks of estimated magnitude; (iii) combined analysis of systematic annual maxima augmented with historical peaks of estimated magnitude exceeding a known threshold, and (iv) sensitivity analysis including only the very largest historical flood events. Use of the historical information was found to yield much tighter confidence intervals of risk estimates, with uncertainty reduced by up to 40% for the 100 yr return frequency event when historical information was added to the gauged data.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.5194/nhess-14-2817-2014
UKCEH and CEH Sections/Science Areas:	Reynard
ISSN:	1561-8633
Additional Information. Not used in RCUK Gateway to Research.:	Open Access paper - Official URL link provides full text
NORA Subject Terms:	Hydrology
Related URLs:	Discussion paper
Date made live:	02 Dec 2014 10:47 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/508959

Actions (login required)

View Item

Document Downloads

More statistics for this item...