TSUNAMI EVACUATION PLAN FOR THE CITY OF TANGIER-MOROCCO BASED ON GIS TOOLS

Morocco is located in convergence zone between two major plates, the Eurasian and the African plates. Moroccan coastal regions are prone to tsunami hazard caused by major earthquakes located along this boundary. The rapid growth of population and expansion in infrastructures and economic settlements in Moroccan coastal areas make them more vulnerable to tsunami threat. Tsunami evacuation plan is an important tool to mitigate the tsunami impact, it's the most efficient way to save human lives before the waves reach the hazard zone areas. In this study, we propose a tsunami evacuation plan for the city of Tangier-Morocco for horizontal evacuation. This plan is designed considering the tsunami threat from tsunamigenic source located in the SW Iberian margin and using the inundation maps of the worst case scenario to define the flooding area. The evacuation plan is elaborated through modeling evacuation routes using Closet Facility tool implemented in ESRIS's ArcMap 10.2 geographic information system (GIS) software. The proposed evacuation plan give valuable information to local government authorities and emergency managers in order to implement an official evacuation plan for Tangier city. It also provides practical support to increase community resilience

NEAMTHM18

European-Union Civil Protection Mechanism, DG-ECHO, Agreement Number: ECHO/SUB/2015/718568/PREV26Published6T. Studi di pericolosità sismica e da maremoto1SR TERREMOTI - Sorveglianza Sismica e Allerta Tsunami2SR TERREMOTI - Gestione delle emergenze sismiche e da maremoto4IT. Banche dat

The making of the NEAM Tsunami Hazard Model 2018 (NEAMTHM18)

The NEAM Tsunami Hazard Model 2018 (NEAMTHM18) is a probabilistic hazard model for tsunamis generated by earthquakes. It covers the coastlines of the North-eastern Atlantic, the Mediterranean, and connected seas (NEAM). NEAMTHM18 was designed as a three-phase project. The first two phases were dedicated to the model development and hazard calculations, following a formalized decision-making process based on a multiple-expert protocol. The third phase was dedicated to documentation and dissemination. The hazard assessment workflow was structured in Steps and Levels. There are four Steps: Step-1) probabilistic earthquake model; Step-2) tsunami generation and modeling in deep water; Step-3) shoaling and inundation; Step-4) hazard aggregation and uncertainty quantification. Each Step includes a different number of Levels. Level-0 always describes the input data; the other Levels describe the intermediate results needed to proceed from one Step to another. Alternative datasets and models were considered in the implementation. The epistemic hazard uncertainty was quantified through an ensemble modeling technique accounting for alternative models' weights and yielding a distribution of hazard curves represented by the mean and various percentiles. Hazard curves were calculated at 2,343 Points of Interest (POI) distributed at an average spacing of ∼20 km. Precalculated probability maps for five maximum inundation heights (MIH) and hazard intensity maps for five average return periods (ARP) were produced from hazard curves. In the entire NEAM Region, MIHs of several meters are rare but not impossible. Considering a 2% probability of exceedance in 50 years (ARP≈2,475 years), the POIs with MIH >5 m are fewer than 1% and are all in the Mediterranean on Libya, Egypt, Cyprus, and Greece coasts. In the North-East Atlantic, POIs with MIH >3 m are on the coasts of Mauritania and Gulf of Cadiz. Overall, 30% of the POIs have MIH >1 m. NEAMTHM18 results and documentation are available through the TSUMAPS-NEAM project website (http://www.tsumaps-neam.eu/), featuring an interactive web mapper. Although the NEAMTHM18 cannot substitute in-depth analyses at local scales, it represents the first action to start local and more detailed hazard and risk assessments and contributes to designing evacuation maps for tsunami early warning

The Making of the NEAM Tsunami Hazard Model 2018 (NEAMTHM18)

ABSTRACT: The NEAM Tsunami Hazard Model 2018 (NEAMTHM18) is a probabilistic hazard model for tsunamis generated by earthquakes. It covers the coastlines of the North-eastern Atlantic, the Mediterranean, and connected seas (NEAM). NEAMTHM18 was designed as a three-phase project. The first two phases were dedicated to the model development and hazard calculations, following a formalized decision-making process based on a multiple-expert protocol. The third phase was dedicated to documentation and dissemination. The hazard assessment workflow was structured in Steps and Levels. There are four Steps: Step-1) probabilistic earthquake model; Step-2) tsunami generation and modeling in deep water; Step-3) shoaling and inundation; Step-4) hazard aggregation and uncertainty quantification. Each Step includes a different number of Levels. Level-0 always describes the input data; the other Levels describe the intermediate results needed to proceed from one Step to another. Alternative datasets and models were considered in the implementation. The epistemic hazard uncertainty was quantified through an ensemble modeling technique accounting for alternative models' weights and yielding a distribution of hazard curves represented by the mean and various percentiles. Hazard curves were calculated at 2,343 Points of Interest (POI) distributed at an average spacing of ∼20 km. Precalculated probability maps for five maximum inundation heights (MIH) and hazard intensity maps for five average return periods (ARP) were produced from hazard curves. In the entire NEAM Region, MIHs of several meters are rare but not impossible. Considering a 2% probability of exceedance in 50 years (ARP≈2,475 years), the POIs with MIH >5 m are fewer than 1% and are all in the Mediterranean on Libya, Egypt, Cyprus, and Greece coasts. In the North-East Atlantic, POIs with MIH >3 m are on the coasts of Mauritania and Gulf of Cadiz. Overall, 30% of the POIs have MIH >1 m. NEAMTHM18 results and documentation are available through the TSUMAPS-NEAM project website (http://www.tsumaps-neam.eu/), featuring an interactive web mapper. Although the NEAMTHM18 cannot substitute in-depth analyses at local scales, it represents the first action to start local and more detailed hazard and risk assessments and contributes to designing evacuation maps for tsunami early warning

Tsunami impact and vulnerability in the harbour area of Tangier, Morocco

In this study, we assess tsunami impact and building vulnerability in the harbour area of Tangier – Morocco. Tsunami impact is evaluated through performing high-resolution inundation modelling. To assess buildings tsunami vulnerability, we use a geographic information system (GIS) multi-criteria approach based upon weight and classification factors. The methodology includes various steps: (i) identification of the most hazardous earthquake tsunamigenic sources, (ii) computation of high-resolution digital elevation model, (iii) simulation of inundation, (iv) field survey to classify buildings and defence structures and (v) application of the GIS-based model to produce final vulnerability map. Results show the potential tsunami impact and vulnerability that Tangier coast might face due to the occurrence of a large tsunami event in the region. Inundation map indicates that a coastal area of over 4.5 km2 is prone to tsunami flood with flow depths ranging from 0.5 to more than 6 m. Vulnerability map highlights different levels of expected buildings vulnerability to tsunami impact, which vary from “very high” for single-storey structures, located in the city harbour and along the sandy beach, to “low” for multi-storeys RC structures. Both inundation and vulnerability maps have important implications for decision makers and land use planning aiming to mitigate tsunami hazard in the North East Atlantic region