Addressing climate extremes in Coastal Management: the case of the Uruguayan coast of the Rio de la Plata System

• Autor(a) principal: Verocai,José E.
• Data de Publicação: 2015
• Outros Autores: Gómez-Erache,Monica, Nagy,Gustavo J., Bidegain,Mario
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://scielo.pt/scielo.php?script=sci_arttext&pid=S1646-88722015000100008
• topic: water level; storm surges; river flow; climate adaptation; ENSO; Montevideo

This paper deals with current storm surges (extremes) in the Uruguayan coast of the Rio de la Plata system (Argentina-Uruguay), a large (38,000 km2) microtidal (<0.5 m) river estuary. Extremes are associated with two synoptic situations able to increase water level above mean sea level (MSL) at Montevideo (=102 cm): the passage of cold fronts and extra-tropical cyclones over Atlantic coast. The assessment of coastal hazards and the reduction of the associated risks can be embedded within Coastal Management (ICZM). Infrastructure frequently does not comply with the legal 250 m setback. Thus, possible impacts due to inundation and flooding related to sea-level rise (SLR) and extremes respectively are high. Also, rapid-onset high river inflow often associated with El Niño events, are relevant due to the positive water level anomaly (&gt; 10 cm) related to them. The existence of differences in the monthly distribution of both MSL and extremes occurrence suggest that both wind climate and river inflow (QRP) explain them. The most severe extremes (= 350 cm) at Montevideo have occurred before 1935. The frequency of events =200, 250 and 280 cm has slightly increased over 2003-2012, which is not attributed neither to SLR nor to increased inflow, but to wind regime changes. Two extreme events (March 1998 and August 2005) are presented which serve to enhance our understanding of the causality and timing of extremes and as analogues to developing scenarios under a changing climate. Some impacts are as follows: coastal stormwater and sewage systems become useless affecting beach quality, artisanal fisheries income is reduced, and sandy beaches and bars are eroded. Among the several obstacles to achieving a comprehensive ICZM in regards to extreme events is the lack of an effective monitoring network. This paper aims to increase awareness, research and application of the knowledge of extreme events on ICZM and risk-management in the face of SLR and flooding.