Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Sensitivity analysis of the methodology for quantifying cliff erosion using airborne LiDAR - examples from Cornwall, UK.

Earlie, Claire, Masselink, Gerd, Russell, Paul and Shail, Robin 2013. Sensitivity analysis of the methodology for quantifying cliff erosion using airborne LiDAR - examples from Cornwall, UK. Journal of Coastal Research 65 , pp. 470-475. 10.2112/SI65-080.1

Full text not available from this repository.

Abstract

The widespread problem of coastal cliff erosion and the management of the risk to infrastructure and property calls for robust quantification of cliff erosion rates. Quantification of sea-cliff rates of retreat on an annual to decadal time scale has typically been limited to rapidly eroding soft rock coastlines. This study uses airborne LiDAR technology to estimate cliff volume changes in hard rock environments to determine linear retreat rates. One epoch of LiDAR data was analysed (2007/2008–2010/2011) for ten sites around the coast of the southwest of England (Cornwall), selected due to the spatial variability in regional morphological processes, lithology and wave climate. Quantifying cliff recession rates using two LiDAR-derived Digital Elevation Models (DEM) requires selection of an elevation change threshold, below which the morphology is assumed to have undergone no significant change, referred to as the ‘vertical change threshold'. The errors inherent in using LiDAR and the various thresholds at which the data could be evaluated were tested. Linear rates of retreat were found to vary according to the threshold of error chosen, providing decreasing rates with an increase in threshold above 0.2–0.3 m. The rates of retreat observed at some low energy sites was of the same magnitude and in some cases lower (0.01–0.03 m yr−1) than the threshold of error inherent in the LiDAR data (0.03–0.1 m). The results were compared with the rates of retreat obtained from analysis of historic maps in Shoreline Management Plans which are non-statutory strategic assessments of the risks associated with coastal erosion that ultimately inform local and regional policy. Analysis of coastal erosion using LiDAR data tended to highlight the localised failures that occur episodically and which are averaged out in the rates derived from longer term analysis of historic maps.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Earth and Ocean Sciences
Subjects: G Geography. Anthropology. Recreation > GC Oceanography
Q Science > QE Geology
Uncontrolled Keywords: Root mean squared error, Shoreline management plan, hard-rock coastline, Digital elevation model
Publisher: Coastal Education and Research Foundation
ISSN: 0749-0208
Date of First Compliant Deposit: 16 January 2017
Date of Acceptance: 6 March 2013
Last Modified: 04 Jun 2017 09:36
URI: http://orca-mwe.cf.ac.uk/id/eprint/97477

Actions (repository staff only)

Edit Item Edit Item