Floods

Overview

According to the International Federation of Red Cross and Red Crescent Societies World Disasters Report, floods are the most common natural disaster in the world. During the decade of 2005-2014, floods accounted for roughly 45% of all natural disasters (and people affected by them) and caused an average of 6,000 reported deaths per year and $34 billion in annual damages worldwide. Satellites offer the ability to map floods from space, enabling disaster responders to know what is happening in regions where they may not have information from people in the ground. This flood mapping, when combined with computer simulations of historic floods, can also be used to assess the risk of flooding and the changes in that risk over time as climate changes, oceans rise, and the land subsides. The CEOS WGDisasters has worked for several years t move forward the state-of-the-art for satellite based flood risk reduction, designing new approaches and facilitating user uptake so that flood risk management can better benefit from satellite data.

NamibiaFloodDashboard

Figure 1 The Namibia Flood Dashboard

The CEOS Working Group on Disasters recently completed a three-year Flood Pilot to make flood-related information from satellites more readily available and to demonstrate its value to disaster managers and others. The Flood Pilot had three main objectives:

  1. Create a Global Flood Dashboard to serve as a “one-stop shop” for information from a number of existing systems for monitoring and predicting floods in real-time.
  2. Create three regional Flood Pilots that are focused on delivering satellite products with a greater amount of spatial detail for smaller areas, specifically:
    • The Caribbean, with a particular focus on Haiti);
    • Southern Africa, including Namibia, South Africa, Zambia, Zimbabwe, Mozambique and Malawi;
    • Southeast Asia, with a particular focus on the lower Mekong River Basin and the island of Java, Indonesia.
  3. Encourage each participating country to develop at least a basic capacity to access these data, understand them, and make them a part of their decision-making process.

The Flood Pilot developed the concept for the Global Dashboard but was unable to identify a suitable host for the platform; however, regional Dashboards (Fig. 1) were created for the three Regional Pilots and significant amounts of EO data and derived products were provided in near-real time when floods occurred in these Pilot areas, as well as to other users when floods occurred elsewhere. The Namibia Department of Water Affairs, Hydrology Division noted the benefits of, among other things, “The use of optical and radar images for flood mapping including access to the International Disaster Charter data…the tremendous access to satellite images and the actual use of these images by our staff…and last but not least the capacity building and access to new techniques for our young professionals.” The Pilot also adapted more efficient means of transmitting flood-related information that were well-received; for instance, C. Vaughan of the Federal Emergency Management Agency stated “This flood products for Louisiana in May 2016 converted to GIS layers and submitted via an ojo-streamer client] is absolutely the direction we want to head [API based].”

As a result of this work, a number of participating countries have developed or improved their capacity to not only use flood maps derived from EO imagery but also to develop their own products (Fig. 2).

Figure 2. Maps of flood damage in Belize produced by the Caribbean Institute of Meteorology and Hydrology using RADARSAT-2 images.

Figure 2. Maps of flood damage in Belize produced by the Caribbean Institute of Meteorology and Hydrology using RADARSAT-2 images.

Demonstrator

The next step forward is embodied in a proposed Flood Demonstrator effort that is currently under development. The goals of the Flood Demonstrator would be:

  1. Transition from hazard identification to risk assessment, because identifying areas of flood risk before the event is the next critical step for improving Disaster Risk Reduction. This would be done by using archival EO data and flood models to quantify risk based on historic flooding;
  2. Provide spatial scaling for users between regional and global: This would build upon the foundational concepts established in the Flood Pilot to build upon the existing portals to create an integrated flood data portal that serves both global and regional users with both archive and real-time EO data products
  3. Map flooded areas where it matters the most, particularly urban areas with dense populations and significant flood risks. Improvements in sensor spatial resolution and in data analysis techniques are now making it possible to accurately map flood risk in urban areas.

Contact

The membership and leadership of the Flood Demonstrator is still being finalized; for further information please contact bob.kuligowski@noaa.gov.