The Risk Mapping of Coastal Flooding Areas Due to Tsunami Wave Run-Up Using DAS Model and its Impact on Nekor Bay (Morocco)

Abstract

The Al-Hoceima region is threatened by tsunami hazard because of its location in the coastal area of the Mediterranean Sea, besides the shallow seismically active region south of the Alboran Sea. Therefore, the current study presents a novel model to map coastal flooding potential zones due to tsunami wave run-up in Nekor bay using three natural parameters (distance from coastline, altitude and slope) in a geographic information system (GIS) environment. Furthermore, the coastal flooding simulation using 4 scénarios (1, 2, 3, 4m) based on the run-up elevation according to tsunami wave elevation (TWE) literature of the study area is used to confirm the DAS model result, and to estimate the potential impacts. The result of the DAS model revealed that 1 km from the coast to the Nekor plain is the most exposed to the impact of tsunamis generated south of the Alboran Sea. The coastal flooding simulation confirmed the DAS result, and the damage estimation of the urban area and the agriculture was respectively 2 and 98% for run-up 1 m, 3% and 97% for run-up 2m, 4% and 96% for run-up 3m, and for the worst case scenario of 4 m was 3% and 97%. Therefore, the results obtained show that the major potential impact of coastal flooding in Nekor plain is the salinization of agricultural land. Finally, we propose a sustainable solution utilizing a controlled forest along the coast to reduce future tsunami impacts on Nekor bay.