Lepore, C. Kamal, S. A., Shanahan, P. Bras, R. L., Rainfall-induced landslide susceptibility zonation of Puerto Rico. Environmental Earth Science, 2011. DOI 10.1007/s12665-011-0976-1
Abstract:
Landslides are a major geologic hazard with
estimated tens of deaths and $1–2 billion in economic
losses per year in the US alone. The island of Puerto Rico
experiences one or two large events per year, often triggered
in steeply sloped areas by prolonged and heavy
rainfall. Identifying areas susceptible to landslides thus has
great potential value for Puerto Rico and would allow
better management of its territory. Landslide susceptibility
zonation (LSZ) procedures identify areas prone to failure
based on the characteristics of past events. LSZs are here
developed based on two widely applied methodologies:
bivariate frequency ratio (FR method) and logistic regression
(LR method). With these methodologies, the correlations
among eight possible landslide-inducing factors over
the island have been investigated in detail. Both methodologies
indicate aspect, slope, elevation, geological discontinuities,
and geology as highly significant landslide-inducing
factors, together with land-cover for the FR method and
distance from road for the LR method. The LR method is
grounded in rigorous statistical testing and model building
but did not improve results over the simpler FR method.
Accordingly, the FR method has been selected to generate a
landslide susceptibility map for Puerto Rico. The landslide
susceptibility predictions were tested against previous
landslide analyses and other landslide inventories. This
independent evaluation demonstrated that the two methods
are consistent with landslide susceptibility zonation from
those earlier studies and showed this analysis to have resulted
in a robust and verifiable landslide susceptibility zonation
map for the whole island of Puerto Rico.