Since the mid-1970s, U.S. satellite observation gathered an exceptionally valuable but still largely un-harvested record of flood inundation world-wide. Commencing in late 1999, the two NASA MODIS sensors also obtained daily surveillance, year after year, of all of the Earth’s flood waters; this archival record is now supplemented by frequent repeat, wide-swath ground-imaging sensors aboard near-polar orbiting (NPO) Suomi. Such combined EO data can be compared to the record of earthquake seismicity provided by seismographic stations; they provide the only objective characterization of many extreme, damaging flood events. This globally consistent information of past events should be deployed to its maximum utility in defining areas of flood risk, and be used as well during new floods to assist with their characterization. In the developing nations, the remote sensing archive provides the immediate opportunity, even without hydrological data infrastructure, to directly identify hazardous land areas. When coupled with U.S. satellite data-driven global hydrological models, there is also the opportunity for early prediction and characterization of flood inundation in near real time.
Activities for the period
Develop, test and apply methods to utilize satellite remote sensing and other Earth observations with models and maps to estimate location, intensity and duration of floods globally in real-time and a durable monitoring system of flood risk with climate change. An initial operational capability could be established with the appropriate community and global framework within a few years. Further achievements and milestones will align with data sharing and integration of models, tools and new Earth observing networks. This would involve observation of flood inundation (e.g., via MODIS, VIIRS, and other sensors) and use of satellite precipitation information (e.g. via GPM) and hydrological models.
As climate changes, flood statistics change and achieving results in this effort over the next several years will be critical. While hazard evaluation has for many decades proceeded using assumed stationarity of flood frequency distributions, new floods-of-record at any location thereby present a well-known dilemma to policy makers and to hydrologists: immediately include the new extreme flood in the flow series and thus increase the size of the regulatory floodplain, or use the pre-flood flow records to label the exceptional new event as, for example, “the 1000 year flood” (e.g., Colorado Front Range, 2013).
We can use the powerful observations (of actual floods) as well as increasingly accurate satellite data-driven global hydrological models to accommodate floods in their changing climate and changing environment context, and address flood hazard and exceedance risk probabilities quite directly: by putting into routine operational use the observed record of inundation from actual floods, that have been obtained and are being obtained by orbital Earth observation systems.
Mainly in-kind contributions.
Members: EC (JRC), USA.
Participating Organizations: CEOS, UNEP, UNESCO, WB, WMO.
Others: Development Bank of Latin America (CAF); Global Flood Partnership (GFP); International Committee of the Red Cross/Red Crescent (ICRC); United Nations Development Programme (UNDP); World Food Programme (WFP); private sector partners (e.g. Google, Coca Cola, and the insurance sector).
Leadership & Contributors (this list is being populated)