Quantifying uncertainties of sandy shoreline change projections as sea level rises

Gonéri Le Cozannet*, Thomas Bulteau, Bruno Castelle, Roshanka Ranasinghe, Guy Wöppelmann, Jeremy Rohmer, Nicolas Bernon, Déborah Idier, Jessie Louisor, David Salas-y-mélia

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

80 Citations (Scopus)
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Sandy shorelines are constantly evolving, threatening frequently human assets such as buildings or transport infrastructure. In these environments, sea-level rise will exacerbate coastal erosion to an amount which remains uncertain. Sandy shoreline change projections inherit the uncertainties of future mean sea-level changes, of vertical ground motions, and of other natural and anthropogenic processes affecting shoreline change variability and trends. Furthermore, the erosive impact of sea-level rise itself can be quantified using two fundamentally different models. Here, we show that this latter source of uncertainty, which has been little quantified so far, can account for 20 to 40% of the variance of shoreline projections by 2100 and beyond. This is demonstrated for four contrasting sandy beaches that are relatively unaffected by human interventions in southwestern France, where a variance-based global sensitivity analysis of shoreline projection uncertainties can be performed owing to previous observations of beach profile and shoreline changes. This means that sustained coastal observations and efforts to develop sea-level rise impact models are needed to understand and eventually reduce uncertainties of shoreline change projections, in order to ultimately support coastal land-use planning and adaptation.

Original languageEnglish
Article number42
Number of pages11
JournalScientific reports
Issue number1
Early online date10 Jan 2019
Publication statusPublished - 2019

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