Sellanes, L.; Alonso, R., and Solari, S., 2024. Performance analysis of groyne fields on the Uruguayan coast. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 814-818. Charlotte (North Carolina), ISSN 0749-0208.

Groyne fields are one of the most common coastal structures on the Uruguayan coast of the Rio de la Plata estuary. However, the performance of these structures has not been systematically evaluated since the late 1970s. Knowing and understanding the past performance of these structures is key to predict their future performance, and to plan the adaptation of these beaches to climate change. A background review of the performance of the groynes prior to the 1980s was carried out, as well as the analysis of aerial photos and historical plans prior to 1985. Then, satellite images from 1985-present, processed with CoastSat, were analysed to quantify the evolution of the coastline, with particular attention to the areas where new groynes were built, or existing ones were enlarged in the early 1980s. At the same time, the hydrodynamics of the groyne fields were analysed using XBeach to relate the observed behaviour to different geometric variables (e.g. spacing and length of the groynes). The results indicate that the groyne fields located on the Uruguayan coast have been successful in terms of their functional performance, managing to advance and maintain the position of the coastline, and that in general their hydrodynamic behaviour is that of short groynes. However, several groynes have presented poor structural performance, in some cases of such importance that their functional performance has been compromised. In addition, the rate of sediment accumulation in some groyne fields has allowed gaining insight into the sediment budget in the littoral cells in which they are installed.