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| Titel |
Tsunami hazard assessment in El Salvador, Central America, from seismic sources through flooding numerical models. |
| VerfasserIn |
J. A. Álvarez-Gómez, I. Aniel-Quiroga, O. Q. Gutiérrez-Gutiérrez, J. Larreynaga, M. González, M. Castro, F. Gavidia, I. Aguirre-Ayerbe, P. González-Riancho, E. Carreño |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1561-8633
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| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 13, no. 11 ; Nr. 13, no. 11 (2013-11-19), S.2927-2939 |
| Datensatznummer |
250085560
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| Publikation (Nr.) |
 copernicus.org/nhess-13-2927-2013.pdf |
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| Zusammenfassung |
| El Salvador is the smallest and most densely populated country in Central
America; its coast has an approximate length of 320 km, 29
municipalities and more than 700 000 inhabitants. In El Salvador there were 15 recorded tsunamis between 1859 and 2012, 3 of them causing damages
and resulting in hundreds of victims. Hazard assessment is commonly based on
propagation numerical models for earthquake-generated tsunamis and can be
approached through both probabilistic and deterministic methods. A deterministic
approximation has been applied in this study as it provides essential
information for coastal planning and management. The objective of the
research was twofold: on the one hand the characterization of the threat over
the entire coast of El Salvador, and on the other the computation of flooding
maps for the three main localities of the Salvadorian coast. For the latter
we developed high-resolution flooding models. For the former, due to the
extension of the coastal area, we computed maximum elevation maps, and from
the elevation in the near shore we computed an estimation of the run-up and
the flooded area using empirical relations. We have considered local sources
located in the Middle America Trench, characterized seismotectonically, and
distant sources in the rest of Pacific Basin, using historical and recent
earthquakes and tsunamis. We used a hybrid finite differences–finite
volumes numerical model in this work, based on the linear and non-linear
shallow water equations, to simulate a total of 24 earthquake-generated
tsunami scenarios. Our results show that at the western Salvadorian coast,
run-up values higher than 5 m are common, while in the eastern area,
approximately from La Libertad to the Gulf of Fonseca, the run-up values are
lower. The more exposed areas to flooding are the lowlands in the Lempa River
delta and the Barra de Santiago Western Plains. The results of the empirical
approximation used for the whole country are similar to the results obtained
with the high-resolution numerical modelling, being a good and fast
approximation to obtain preliminary tsunami hazard estimations. In Acajutla
and La Libertad, both important tourism centres being actively developed,
flooding depths between 2 and 4 m are frequent, accompanied with high
and very high person instability hazard. Inside the Gulf of Fonseca the
impact of the waves is almost negligible. |
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