Revista Recursos Hdricos

DOI:10.5894/rh41n1-cti3
Este artigo parte integrante da Revista Recursos Hdricos, Vol. 41, N 1, 29-40, maro de 2020.

Ensaios de agitao no porto de Leixes em cenrio de alterao climtica

Wave disturbance tests in the port of Leixes on a climate scenario

Miguel Silva¹, Conceio J.E.M. Fortes^{2 *}, Rute Lemos³, Maria da Graa Neves⁴, Carlos Caeiro⁵

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^* Autor correspondente. Email : jfortes@lnec.pt
¹ Aluno da Escola Profissional de Cincias Geogrficas, Lisboa, Portugal, 96masilva@gmail.com
² Investigadora Principal do Laboratrio Nacional de Engenharia Civil
³ Tcnica Superior do Laboratrio Nacional de Engenharia Civil 4 Investigadora Auxiliar com Agregao do Laboratrio Nacional de Engenharia Civill
⁵ Tcnico Superior na Escola Profissional de Cincias Geogrficas

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RESUMO

Para caracterizar a agitao martima no Porto de Leixes aps o prolongamento do quebra-mar exterior, sob condies de alteraes climticas foi realizado um extenso grupo de ensaios em modelo fsico tridimensional de agitao, num tanque do LNEC, escala 1:80, representando-se toda a bacia porturia e o prolongamento do quebra-mar exterior do Porto de Leixes. Foram realizados ensaios com diferentes condies de agitao incidente para o rumo W e com dois nveis de mar, que correspondem ao nvel mdio e a preia-mar com uma sobrelevao representativa dos efeitos das alteraes climticas e da sua influncia na agitao martima. Foi medida a agitao em 30 pontos localizados na entrada do porto e no interior da bacia porturia e analisou-se o abrigo da bacia porturia com a ampliao do quebra-mar norte e as diferenas entre o abrigo para os dois nveis de mar ensaiados. As principais concluses dos ensaios realizados foram que os maiores valores de alturas de onda ocorreram na zona exterior e de entrada do porto, diminuindo para o seu interior. Ao longo do canal de navegao, as alturas de onda vo diminuindo e no interior do porto obtiveram-se valores da altura de onda pequenos. A subida do nvel do mar, para as condies ensaiadas, no afeta significativamente a agitao no interior da bacia porturia. No entanto, no exterior e zona de entrada do porto contribui para alteraes da agitao que diferem consoante o perodo de pico e a altura de onda significativa incidente.

Palavras-chave: Agitao, Porto de Leixes, alterao climtica.

ABSTRACT

In order to characterize the sea wave characteristics in the Port of Leixes after the extension of the outer breakwater under conditions of climatic changes, an extensive group of tests was carried out in a three-dimensional physical model of agitation in a 1:80 scale. The tests were made at a LNEC's tank, reproducing the entire port basin and the extension of the outer breakwater of the Port of Leixes. Tests were carried out with different incident wave conditions coming from W and with two tide levels, corresponding to the average tide level and to the high tide level with elevation, as a climatic changes effect and its influence on the wave parameters. The wave characteristics were measured in 30 points located from the entrance of the port to the interior of the port basin. The shelter of the port basin with the expansion of the north breakwater was analyzed as well as the differences between the results for the two tide levels tested. The main conclusions of the tests were that the highest values of wave heights occurred in the outer zone and at the entrance of the port, decreasing towards the interior. Along the navigation channel, the wave heights are decreasing and inside the port small values of the wave height were obtained. Rising sea levels for the conditions tested do not significantly affect waves inside the port basin. However, outside the port and at port entry zone, such increase on the sea level contributes to differences on wave characteristics that depend on the peak period and the significant incident wave height.

Keywords: Wave agitation, Leixes Harbour, Climate change.