Publicação
Oblique rainfall and contemporary geomorphological dynamics (Serra da Estrela, Portugal)
| Resumo: | Coarse sand accumulations are polygenic microforms that attain a width of several metres, a height up to 30 – 40 cm,a gradient of 8–12°and a slope length up to 1 m. These accumulations are frequent in the gruss-covered plateausof the granite mountains of central and northern Portugal,but they have been described in other mountain areas (i.e.Cairngorms, Scotland). Though these microforms are frequent features, studies on them are rare. They have beenattributed to complex genesis controlled primarily byaeolian processes, but also by wash and cryogenic dynamics.Results presented here add new insights into the origin of the sand accumulations and emphasize the importance ofrainsplash-saltation induced by oblique rainfall as the main transportation mechanism. The study was conducted inthe Serra da Estrela, a granite mountain in central Portugal (1993 m above sea level) and is supported by a detailedmapping of the orientation of the accumulations, monitoring of the surface material and analysis of meteorologicaldata. The results are particularly significant since they indicate that the coarse sand accumulations are very activefeatures that show a clear climatic and ecological signal. |
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| Autores principais: | Vieira, Goncalo |
| Outros Autores: | Mora, Carla; Gouveia, Maria Manuel |
| Assunto: | Coarse sand accumulations Rainsplash-saltation Mediterranean mountains |
| Ano: | 2004 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Coarse sand accumulations are polygenic microforms that attain a width of several metres, a height up to 30 – 40 cm,a gradient of 8–12°and a slope length up to 1 m. These accumulations are frequent in the gruss-covered plateausof the granite mountains of central and northern Portugal,but they have been described in other mountain areas (i.e.Cairngorms, Scotland). Though these microforms are frequent features, studies on them are rare. They have beenattributed to complex genesis controlled primarily byaeolian processes, but also by wash and cryogenic dynamics.Results presented here add new insights into the origin of the sand accumulations and emphasize the importance ofrainsplash-saltation induced by oblique rainfall as the main transportation mechanism. The study was conducted inthe Serra da Estrela, a granite mountain in central Portugal (1993 m above sea level) and is supported by a detailedmapping of the orientation of the accumulations, monitoring of the surface material and analysis of meteorologicaldata. The results are particularly significant since they indicate that the coarse sand accumulations are very activefeatures that show a clear climatic and ecological signal. |
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