# Tsunami Modeling and Satellite-Based Emergency Mapping: Workflow Integration Opportunities  
[PERSON]  
1 ITHACA - Information Technology for Humanitarian Assistance, Cooperation and Action, 10138 Torino, Italy European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy Interuniversity Department of Regional and Urban Studies and Planning, Politecnico di Torino, 10125 Torino, Italy Department of Architecture and Design, Politecnico di Torino, 10125 Torino, Italy Correspondence: [EMAIL_ADDRESS]; Tel.: +39-011-1975-185211141  
estimate of the impact all along the coast was not immediately available and, therefore, an assessment of the potential damage was necessary.  
In the immediate aftermath of the event, both the Copernicus Emergency Management Service-Rapid Mapping (CEMS-RM) and the International Charter Space and Major Disasters (Charter), two of the major Satellite-based Emergency Mapping (SEM) mechanisms [1], were activated. CEMS-RM assessed the damages caused by both the earthquake and the induced tsunami, using visual interpretation of very high resolution (VHR) satellite imagery acquired after the event (and compared to pre-event data). The analysis resulted in the identification of damage (and their grade) to buildings and the main infrastructures, together with impact proxies such as the presence of debris floating on the ocean waters near to the coast or the coastline erosion.  
For the effectiveness of rapid mapping the availability of a post-event image is crucial: for damage assessment after a tsunami typically very high resolution optical imagery is used. Satellite sensors need to be programmed and, as optical sensors depend on sunlight, there is only one potential tasking opportunity per day for each sensor (at about 10 am local time). As highlighted in the conclusions of [1], \"a major challenge for EO disaster response is still the satellite tasking, reprogramming, and image collection; these require ~2 days on average to complete, as compared with the ~6 to 8 h required for mapping after the availability of satellite imagery.\"  
The purpose of this contribution is, therefore, to explore, evaluate and discuss the integration of a tsunami alerting system within an operational SEM workflow, with a specific focus on providing relevant information for an early-tasking of satellite post-event imagery to reduce the time delay between the event itself and the availability of the first SEM-based damage assessment. Tsunami model-derived affected areas, combined with exposure data (such as the presence of urbanized areas along the coast), provide useful information to plan and prioritize the satellite data tasking effectively.  
The combination of early tasking using tsunami modelling results and SEM may support the decision making process during emergency response operations as this can indicate which areas should be served first by humanitarian assistance. This is especially relevant when very large areas are hit by the wave. Nevertheless, the intrinsic impact of the estimated earthquake parameters on the spatial and thematic accuracy of the tsunami model outputs should be taken into account, carefully evaluating the best threshold between the timeliness of satellite pre-tasking and level of uncertainty of the target areas.  
Section 2 is aimed at providing a general overview on the methods discussed in this contribution, namely the tsunami modeling and the satellite-based emergency mapping. Section 3 is focused on the evaluation of the aforementioned methods applied to the tsunami case study (Chile, 2015), assessing a possible integration of both methods in an operational SEM workflow. Lastly, a critical discussion on the results and an outlook on possible future developments are provided in Section 4.