Assessment of the debris-flow susceptibility in tropical mountains using clast distribution patterns.
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Date
2016
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Abstract
Channel morphometric parameters and clast distribution patterns in selected basins of the Ferriferous Quadrangle
tropicalmountains, Brazil, were analyzed in order to assess susceptibility to debris flows. Median bed surface
clast size (D50) in the main streamchannel of these basins shows a coarsening downstream trend with drainage
areas of up to 6 km2, which is attributed to debris flow dominated-channels by some authors. The composition
and roundness of the bed load, clast sand, and the presence of allochthonous large boulders throughout the channels
also suggest the occurrence of past debris flow in the region. Luminescence Optically Stimulated (LOE) dating
points out that debris flow could have occurred as a consequence of climate changes in the Late Pleistocene
and Holocene and it can nowbe triggered by deforestation or extreme rainfall events. There has not been any record
of past debris flow in the study area, or in other mountainous regions of Brazil where debris flows have recently
occurred. Thus, the adopted approach can be useful to assess debris flow susceptibility in this and other
similar areas.
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Median bed surface clast size
Citation
LOPES, L. de O. F. L.; BACELLAR, L. de A. P.; CASTRO, P. de T. A. Assessment of the debris-flow susceptibility in tropical mountains using clast distribution patterns. Geomorphology (Amsterdam), v. 1, p. S0169-555X(16)3, 2016. DisponĆvel em: <https://www.sciencedirect.com/science/article/pii/S0169555X16301957>. Acesso em: 08 fev. 2019.