by Eduardo Reynolds - EFAS Dissemination Centre,
On 15 June 2021, the EFAS Dissemination Centre (DISS) hosted a webinar focused on the link between EFAS and Rapid Mapping for pre-tasking of satellites for flood-impact mapping. More than 100 participants were involved in flood-risk management activities as EFAS partners, national authorities, and personal within ERCC and the EFAS Dissemination Centre attended the webinar. The webinar was led by Eduardo Reynolds from DISS and Milan Kalas from the European Commission (EC) supported for questions.
The webinar aimed to:
- Provide information about how EFAS pre-tasking of satellites works theoretically and in practice.
- Show how standard rapid mapping activations for floods have performed against those activations preceded by an EFAS pre-tasking request.
- Prove the relevance of EFAS in terms of location and predictability of flood peaks to support the use of it for starting the rapid mapping workflow.
First, the webinar started by doing an overview of the different components of the Copernicus Emergency Management Service (CEMS) and products offered by them. Then the webinar continued by going through some of the features of satellite-based emergency mapping and introduces the pre-tasking procedure.
From previous experience, we know that the most time-consuming phase of rapid mapping of disasters takes place during the acquisition of satellite data. One way to improve the satellite-based emergency mapping workflow for faster delivery of crisis information is by implementing forecast-based pre-tasking.
Pre-tasking triggers satellites to proactively capture readings of natural hazard events at the time predicted by an Early Warning System (EWS) rather than waiting for a tasking request from an authorised user. For riverine floods in Europe, this approach utilizes the existing EFAS flood EWS to start data collection. Pre-tasking has several benefits:
- It reduces the time between a catastrophic event and satellite data acquisition.
- It increases the chances of acquiring images at a critical moment.
- It helps to deliver crisis information shortly after the event started, and earlier than with the standard rapid mapping workflow
To illustrate how the EFAS pre-tasking procedure works in practice, the webinar provided details about a flood event that occurred in April 2018 along the Ebro river in Spain for which a rapid mapping service preceded by an EFAS pre-tasking request was activated.
Moreover, the webinar presented rapid mapping performance statistics available from June 2016 and 2020. Compared to standard rapid mapping activations, pre-tasking reduced the delivery time of the first flood map by half a day. This reduction was because images were acquired on average 7 and half hours earlier in the rapid mapping activations related to pre-tasking.
Finally, the webinar proved the relevance of using EFAS to start data collection in the pre-tasking procedure. Thanks to the forecast capability of EFAS in predicting the timing of the flood peaks, the probability of capturing the maximum extent of floods was shown to be high. In addition, the performance statistics showed that users keep on average one-third of the EFAS AOIs demonstrating the relevance of the EFAS forecast in terms of location. Before the webinar was concluded, the benefits of implementing EFAS pre-tasking were summarized and links with more information on the procedure were provided.