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Ação antrópica e erosão da vertente.: Estudo de caso da bacia hidrográfica do rio Tâmega (1981)

1994; Coimbra University Press; Issue: 1 Linguagem: Inglês

1647-7723

António de Sousa Pedrosa, Bernardo de Serpa Marques,

Karst Systems and Hydrogeology

portuguesNo mes de Dezembro de 1981 ocorreu em Cavez, na margem esquerda do vale do Tâmega um movimento de terras que provocou uma grande perda de vidas humanas. Depois de formular algumas hipoteses, os autores observaram atentamente o local da ocorrencia de modo a determinar as causas que originaram este tipo de fenomeno. As caracteristicas topograficas e litologicas e as condicoes climaticas por si so nao justificam a ocorrencia deste tipo de fenomeno. De facto, os autores demonstram que, para alem das condicoes naturais favoraveis, a actuacao antropica acentuou o impacto do fenomeno. A falta de uma correcta compreensao da dinâmica geomorfologica e, muitas vezes, responsavel pelo aumento da frequencia deste tipo de fenomenos. EnglishWhen a catastrophic landslide occurred in a small river basin on the left bank of the Tamega valley, in the Northeast of Portugal, which involved the sudden sliding of several tons of arable land and rocks and caused the destruction of a house and the death of fifteen people, the authors decided to carry out a careful investigation of this geomorphological phenomenon. After having formulated a number of hypotheses, they did a lot of field workin the area and carried out measurements to determine, as accurately as possible, both the real extension and the causes of the occurrence of such a phenomenon in that particular place and at that particular time of the year. A series of studies enabled the authors to come the conclusion that the natural and human-induced causes had been responsible for the disaster. Disasters like this don't unfortunately constitute isolated incidents. Therefore, the authors think it is very important to study the local geomorphology carefully before any houses or the setting up of any human activity within the territory it is responsible for.