LAUSR

ABSTRACT Paniagua-Arroyave, J.F.; Correa, I.D.; Anfuso, G., and Adams, P.N., 2018. Soft-cliff retreat in a tropical coast: The Minuto de Dios sector, Caribbean coast of Colombia. In: Almar, R.; Almeida, L.P.; Trung Viet, N., and Sall, M. (eds.), Tropical Coastal and Estuarine Dynamics. Journal of Coastal Research, Special Issue No. 81, pp 40–49. Coconut Creek (Florida), ISSN 0749-0208 Projections for the year 2100 predict a global mean sea level ~1 m above pre-industrial levels that will likely exacerbate coastal impacts worldwide and especially along vulnerable coastlines of developing countries. Recent studies have predicted a future shoreline retreat linked to the expected acceleration in global sea level rise along the soft-cliffs of Minuto de Dios on the Caribbean coast of Colombia. This study discusses previous results by arguing that an accurate quantification of relative sea level rise was not implemented and cliff retreat predictions are therefore not feasible. Future cliff-top positions and future sediment release were instead calculated by assuming that the historical retreat rate will remain unchanged. Mean end-point retreat between 1938 and 2010 was 1.7±0.4 m/year, which would produce between 2010 and 2060 a shoreline recession of 85 m with a cumulative release of ~530,000 m3 of sediment (for a ~ 1 km of ~ 6 m cliffs). The projected coastal retreat is expected to produce significant impacts to local infrastructure, including the loss of approximately 100 urban constructions. In addition, the 2060 coastline would be located ca. 50 m from the main road that connects Arboletes with the city of Montería. As discussed in this study, climate change-driven sea level rise will likely augment coastal hazards, but with limited data in the region, predictive modeling of future impacts remains speculative. This issue highlights the need for local stakeholders to dedicate resources to further observations. Such efforts will improve predictions, helping inform policy makers to implement successful local coastal management solutions.