Bulletin of the Seismological Society of America; April 2003; v. 93; no. 2;
p. 557-569; DOI: 10.1785/0120020016
© 2003 Seismological Society of America
An Approach to Time-Probabilistic Evaluation of Seismically Induced Landslide Hazard
V. Del Gaudio,
P. Pierri and
J. Wasowski
Dipartimento di Geologia e Geofisica
Università di
BariCampus
via E. Orabona, 4
70125 Bari,
Italy
(V.D.)
Osservatorio Sismologico dell'Università di
Bari,
Campus, via E. Orabona, 4
70125 Bari, Italy
(P.P.)
Consiglio Nazionale delle RicercheCNR-IRPI, sezione di
Bari.
c/o Dipartimento di Ingegneria Civile e Ambientale
Politecnico di
BariCampus
via E. Orabona, 4
70125, Bari,
Italy
(J.W.)
The need for effective strategies for preventing and mitigating damage
caused by earthquake-induced landslides has stimulated recent developments of
techniques for the assessment of seismic-landslide exposure at a regional
scale. However, for a rational risk management, a crucial element is
represented by the time horizon of the hazardous events. A new way to
incorporate the time factor in seismic-landslide hazard assessment is proposed
here. It consists of evaluating the temporal recurrence of seismically induced
slope failure conditions inferred from the Newmark's model: First, by adopting
Arias Intensity to quantify seismic shaking, well-established methods of
seismic hazard assessment are employed to obtain the occurrence probabilities
for different levels of seismic shaking in a time interval of interest. Then,
some empirical relations, based on the Newmark's model, are employed to
evaluate the slope critical acceleration ac for which a
prefixed probability exists that seismic shaking would result in landslide
triggering. The obtained ac values represent the minimum
slope resistance required to keep the probability of seismic-landslide
triggering within the prefixed value. Therefore, the space distribution of the
calculated ac values can be promptly compared with the
actual in situ ac values of specific slopes to estimate
whether these slopes have a significant probability of failing under seismic
action in the future. An example of this approach, applied to an area in
southern Italy (Daunia region), shows that the introduction of the time factor
significantly modifies the representation of the spatial hazard and allows
evaluation of the relevance of seismicity as a landslide triggering agent.
Copyright © 2009 by Seismological Society of America