A critical evaluation of coastal erosion in Rio Grande do Sul, Southern Brazil

Anais da Academia Brasileira de Ciências

Sérgio R. Dillenburg²  Luciana S. Esteves¹  Luiz J. Tomazelli² 

[1] ,Universidade Federal do Rio Grande do Sul Instituto de Geociências Centro de Estudos de Geologia Costeira e OceânicaPorto Alegre RS ,Brasil

关键词: coastal evolution;    Quaternary;    shoreline changes;    coastal barriers;    sediment budget;    evolução costeira;    Quaternário;    mudanças da linha de praia;    barreiras costeiras;    estoque de sedimentos;   

DOI  :  10.1590/S0001-37652004000300014

来源: SciELO

【 摘 要 】

Evidences of coastal erosion in Rio Grande do Sul have been obtained by three methods: (a) analysis of the long-term morphodynamics and stratigraphy of coastal barriers, (b) annual shoreline mapping using the Differential Global Positioning System (DGPS), and (c) local beach profile measurements. The first method reflects coastal erosion as continuity of the geological evolution in the last 5 ka, taking place mainly along the southern half of gentle coastal projections. The second method represents a shorter temporal scale and indicates that approximately 80% of the coast is eroding. Beach profiling has been measured in very few places that are distant from each other since the early 1990s; consequently, their results reflect local and very short time shoreline behavior. A critical evaluation of published data addressing coastal erosion in Rio Grande do Sul strongly suggests that short and long term negative balance on the sediment budget is the main cause of erosion along this coastline.

【 授权许可】

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