Earth Observation Satellites and the 2010/2011 Australian Floods

Back in Mid 2010, the Ocean Surface Topography Mission (OSTM) / Jason 2 satellite, a combined U.S. / French satellite, detected minute changes in the Pacific ocean. Subtle as they were, taken across the Pacific ocean, they added up to a major meteorological change. A new episode of La Niña, where the sea surface temperature across the equatorial Eastern Central Pacific Ocean is lower than normal by 3-5 °C was developing, leading to an increased likelihood of above average rains in Australia.

An Ocean Surface Topography Mission (OSTM)/Jason-2 satellite image of the Pacific Ocean, based on the average of 10 days of data centred on Dec. 26, 2010. (Image Source: NASA)

As 2010 progressed, this meteorological feature made true to the early predictions, and from the U.S. GOES-10, U.S. GOES-12, Japanese MTSAT-1R and Chinese Feng Yun-2 Geostationary Satellites, together with the U.S. NOAA (12 to 18) and Chinese Feng Yun-1 polar orbiting weather satellites, accurate and up to date satellite weather forecast information was provided to the Australian Bureau of Meteorology about how much rain might be ahead.

In the days in late December 2010 and early January, things started to become critical, as an already soaked Australian land, was forecast to have more major rainfall, with predicted flooding. Digital terrain models, which are heavily derived from EO Satellite data, was overlayed by the predicted rainfall, showing very quickly the extent of the impending disaster.

January 10, 2011 Multi-Satellite Precipitation Analysis (MPA) based on data from the NASA / JAXA Tropical Rainfall Measuring Mission (TRMM) (Image Source: NASA)

On the 3rd of January 2011, Emergency Management Australia requested that the U.S. Geological Survey activate the “International Charter Space and Major Disasters” formally requesting that all nations who have signed the treaty provide as much imagery as possible to help with the crisis at hand. The Charter is contributed to by 15 space agencies with 20 satellites available, however as Australia is not a member, and has no satellites, it must rely on the United States for assistance. Over the next few weeks, imagery from a vast array of nations was provided to Australia, particularly from the United States, Europe and Canada.

Flooding around Rockhampton on the 7th of January, 2011 – captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite. The image includes both infrared and visible light to increase the contrast between muddy floodwater and brown earth. (Image Source: NASA)

Before and After imagery from the Italian Space Agency. Image processed by the Geodesy and Earth Observing Systems Group (GEOS), UNSW. Supported by UNSW, LPMA and CRCSI. (Image Source: BBC)

Envisat SAR image of flooding near Rockhampton in Queensland , Jan 2011 (Image Source: ESA)

A RADARSAT-2 Flooding “Change Detection” image, showing the flooding on the 7th of January – highlighting the flooding in Yellow. (Image Source: Canadian Space Agency)

Post flooding, EO Satellites have been used to map the damage, map the changes in the terrain, map soil moisture as well as assess things like potential for damage to the Great Barrier Reef from the run-off.

Soil Moisture across Australia as measured by the ESA Soil Moisture and Ocean Salinity (SMOS) Satellite Mission (Image Source: BBC)

Floodwaters pouring out of Queensland’s swollen rivers threating the Great Barrier Reef (Image Source: NASA)

It has been estimated that the flooding has covered over 75% of the state of Queensland, in an area roughly the size of France and Germany combined, leading to one of Australia’s biggest environmental disasters in living memory.

Earth Observation data has played a key role in helping predict and monitor the recent floods in Australia. In crisis, Earth Observation satellites can, and do save lives and damage, offering advanced warning and prediction of disasters before the arrive, impact when they arrive, and assistance to recovery when they have passed.

Australia is critically reliant on Earth Observation satellites and the data they provide, and yet Australia is also totally reliant on other nations to provide this data at all times, and is not a contributor or member of the International Charter Space and Major Disasters, despite it helping us in our time of need. In the wake of the recent flooding, Australia needs to review the crucial role that Earth Observation Satellite data played, and decide what future role it will play in Australia, and whether we should be the next Country to join the International Charter Space and Major Disasters.