Climate teleconnections and indicators of coastal systems response. (March 2016)

• Record Type: Journal Article
• Authors: Gutiérrez, Ofelia; Panario, Daniel; Nagy, Gustavo J.; Bidegain, Mario; Montes, Carlos
• Is Part Of: Ocean & coastal management. Volume 122(2016)
• Page Start: 64
• Page End: 76
• Publication Date: 2016-03
• Subjects: Sandy beach -- Creek mouths -- Erosion–accretion -- El Niño – La Niña events -- Río de la Plata estuary; AMO Atlantic Multidecadal Oscillation -- AMSL above mean sea level -- ENSO El Niño Southern Oscillation -- MSL mean sea level -- NCEP/NCAR National Center for Environmental Prediction/National Center for Atmospheric Research -- PDO Pacific Decadal Oscillation -- PHTH-WL high tide high – water level -- RdlP Río de la Plata -- SLR sea level rise -- SSTA Sea Surface Temperature Anomalies -- WDL-RM wet/dry line or run-up maxima -- WSA wind speed anomalies; Marine resources -- Management -- Periodicals; Coastal zone management -- Periodicals; Coastal ecology -- Periodicals; Ressources marines -- Périodiques; Littoral -- Aménagement -- Périodiques; Écologie littorale -- Périodiques; Coastal ecology; Coastal zone management; Marine resources -- Management; Periodicals; Electronic journals; 551.46
• DOI: 10.1016/j.ocecoaman.2016.01.009
• Languages: English
• ISSNs: 0964-5691

Abstract

Abstract: This article surveys secular urban sandy beaches erosion – accretion and its relationship with climate teleconnections, e.g., El Niño Southern Oscillation (ENSO), Atlantic Multidecadal Oscillation (AMO), and extreme events, e.g., storm surges, great rivers' floods, and heavy rains in adjacent basins. The paper aims to discuss these issues and the expected coastal retreat as a consequence of manmade climate changes, e.g., sea level rise (SLR) and increased storminess in the coming decades. Several beaches (Buceo, Malvín, Pocitos, Ramírez) and two tidal creek sandy mouths (Carrasco and Pando), with different characteristics but all constrained by coastal linear infrastructure were studied. These sites are located along the urbanised coast of the middle region of Río de la Plata microtidal river estuary. All of them show a more or less strong retreat trend with alternated fluctuations, e.g., weak retreat likely due to sea level rise, significant erosion very likely due to storm surges, and processes of loss of sediment stock, as well as episodes of sand recovery. Therefore, these beaches require interventions to preserve their beach prism and dry sand surface. In search for answers to better understand why and under what conditions the process of advance and retreat of the coastline occur, we have analysed different teleconnections and carried out reanalyses for wind anomalies during ENSO events from 1951 to 2010. Both weak and moderate erosion–accretion periods are likely related to atmospheric anomalies, e.g., wind direction changes and the consequent swell and littoral drift changes, related to El Niño and La Niña events. The former associated with accretion and the latter with erosion. In the past most interventions have been reactive. Increased knowledge of climate and weather relationship with the sedimentary balance provides an approach that would allow developing beach risk-management, pro-active strategies and climate adaption measures focused on the generation and recovery planning based on the analysis of the occurrence and prediction of El Niño/La Niña events. Graphical abstract: Highlights: Urban beaches are suffering alternated processes of erosion–accretion. Analysis of remote sensing series allows highlighting both trends and attribution. Links between erosion–accretion, teleconnections and extreme events are explored. Erosion–accretion processes match quite well with ENSO events and storm surges. ENSO looks like a good predictor of short-term trends useful for beach management.