{"id":94,"date":"2026-02-25T12:28:35","date_gmt":"2026-02-25T11:28:35","guid":{"rendered":"https:\/\/traceclimate.cerege.fr\/?page_id=94"},"modified":"2026-03-03T14:09:20","modified_gmt":"2026-03-03T13:09:20","slug":"sea-level-rise-and-shoreline-position","status":"publish","type":"page","link":"https:\/\/traceclimate.cerege.fr\/?page_id=94","title":{"rendered":"Sea level rise and shoreline position"},"content":{"rendered":"\n

A common approach in coastal geomorphology for assessing the future evolution of littoral systems is to analyse their historical dynamics in order to understand their functioning and infer possible future trajectories (Paskoff, 1998). Within this framework, the evolution of lagoons and shoreline positions between 1857 and 1998 was examined (Fig 1). Over this period, sea level rose by at least 190 mm, based on measurements for 1905\u20131993 (Suanez, Prosper-Laget, and Provansal, 1997). Assuming a linear rate of rise, the total sea-level increase between 1857 and 1998 can be estimated at approximately 296 mm. If shoreline displacement is assumed to depend solely on sea-level rise, such an increase should have produced significant submergence of the Rhone delta plain. However, the 141-year comparison reveals contrasting shoreline responses: east\u2013west oriented beaches retreated by up to 900 m, whereas the Beauduc spit advanced, the Rhone mouth prograded markedly, and the Gracieuse spit developed (Figure 1). These observations show that a sea-level-rise-only framework is insufficient to explain long-term shoreline evolution. In particular, sediment inputs associated with overwash deposits must be considered, as they contribute to vertical and lateral accretion and can offset the effects of rising sea level.<\/p>\n\n\n