Details

Autor(en) / Beteiligte

• El Moussaoui, Said
• Omira, Rachid
• Zaghloul, Mohamed Najib
• El Talibi, Hajar
• Aboumaria, Khadija

Titel

Tsunami hazard and buildings vulnerability along the Northern Atlantic coast of Morocco –the 1755-like tsunami in Asilah test-site

Ist Teil von

• Geoenvironmental disasters, 2017-12, Vol.4 (1), p.1-14, Article 25

Ort / Verlag

Cham: Springer International Publishing

Erscheinungsjahr

2017

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Background The Atlantic Coast of Morocco is prone to tsunami inundation. Therefore, in this region, earthquake-induced tsunami hazard has been intensively investigated leading to the development of a number of coastal inundation models. However, tsunami vulnerability remains not well understood to the same extent as the hazard. In this study, we use high-resolution numerical modeling, detailed field survey and GIS-based multi-criteria analysis to assess the building tsunami vulnerability and its sensitivity to the tide variations. Asilah located in the northwestern Atlantic coast of Morocco, where the impact from the 1755 tsunami is well documented, constitutes the area of this study. Results To model the source-to-coast tsunami processes we used the COMCOT (Cornell Multi-grid Coupled Tsunami Model) numerical code on a set of bathymetric/topographic grid layers (640 m, 160 m, 40 m and 10 m resolutions) with an initial sea-surface perturbation generated using Okada’s formulae and assuming an instantaneous seabed displacement. The tsunami source models in this study correspond to four 1755-like earthquake scenarios. Results show that Asilah’s built environment is highly vulnerable to the tsunami impact that can range from 1.99 to 2.46 km 2 of inundation area, depending on the source and the tidal level considered. The level of building vulnerability decreases considerably when moving away from Asilah’s coastline. Moreover, the variation in the tidal level introduces large change in the modeled tsunami impact and, therefore, affects the level of building vulnerability. Conclusion Thus, we suggest considering the effect of the tide when simulating tsunami hazard and vulnerability, particularly, in coasts where tidal variations are significant. This study provides hazard and vulnerability maps that can be useful to develop the tsunami awareness of the Moroccan coastal population.