Adressing Emergency Flood Mapping and Monitoring of Inland Water Bodies with Sentinel 1-2. Expectative and Perspectives
Yesou, Herve1; Sarti, Francesco2; Tholey, Nadine3; Mouratidis, Antonios2; Clanndillon, Stephen3; Fraipont de, Paul3

The importance of water resources and the escalating frequency and intensity of flood events around the world during the last decades, emphasize the necessity of their timely and cost-effective monitoring by Remote Sensing techniques, with no risk for human lives. The purpose of this paper is to present the current capacity of Earth Observation in detecting and monitoring flooded areas and inland water bodies, by means of different sensors (SAR, optical/IR). This is achieved by using results and experience gained within the International Charter and the Services and Applications For Emergency Response (SAFER), as well as from other relevant case studies such as Dragonproject during the last decade. Based on this experience, the desirable (optimum) and minimum requirements are described, with respect to the capabilities of near-future satellites for water-flood monitoring. Subsequently, the foreseen improvements that the Sentinel-1 and -2 missions will bring are presented, in the direction of meeting this new set of refined requirements, but also in the context of COPERNICUS, the former GMES (Global Monitoring for Environment and Security) initiative. The user requirements for water resources and especially for flood monitoring are very high, with flash-floods being the most demanding case in terms of timely acquisitions of EO data. Sentinels will be able to meet much of these requirements or introduce improvements in this direction; larger swath, regular and shorter revisit time, systematic acquisition strategy over high-risk zones, fast data dissemination, along with the potential of synergistic use of Sentinel-1 and Sentinel-2 data. In the context of the COPERNICUS, the Sentinels will be a milestone of the spatial and temporal improvements in Earth observation dedicated to risk management. While Sentinels will insure an efficient routine surveillance mission, VHR satellites like Pleiades will be tasked on demand over smaller high-risk areas.