Eye in the sky for wildfire risks

Researchers hope the space data will highlight areas at risk from fires

Satellites can be used to help predict where wildfires are likely to occur, a study reports.

By studying shrublands in California, US researchers found that Nasa orbiters can accurately detect factors which contribute to fires developing.

The authors said Earth observation satellites could monitor plant moisture and the ratio of dead to live material, and provide data on potential hotspots.

The findings appeared in the journal Geophysical Research (Biogeoscience).

"This represents an advance in our ability to predict wildfires using data from recently launched instruments," said lead author Dar Roberts, from the University of California at Santa Barbara.

"We have come a long way in just the past five to 10 years and continue to gather much better data on the variables critical in wildfire development and spread."

Early warning

While data from Nasa satellites is already being used to locate wildfires, the researchers hope the technology will be able to predict areas at risk.

Traditional field sampling is limited by high costs, and the number and frequency of sites you can sample Dar Roberts

To assess how effectively the orbiters' instruments measure surface conditions, members of the Los Angeles County Fire Department, over a five-year period, gathered moisture samples from a number of different plant species in southern California.

The ground-gathered data was then compared to measurements recorded by Nasa's Moderate Resolution Imaging Spectrometer (MODIS) on board the agency's Aqua satellite and the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) on the ER-2 spacecraft.

The study, funded by Nasa and the US Joint Fire Science Program, found there was a good correlation between the two sets of data, suggesting that the satellites could be used to identify areas with favourable conditions for wildfires.

However, it worked more effectively in regions where one plant type dominated. The extent of vegetation cover also affected the reliability of the data.

Red dots indicate fires in Russia's Far East, captured by MODIS

"Improving the role of satellite data... is critical," said Professor Roberts, "since traditional field sampling is limited by high costs, and the number and frequency of sites you can sample [is also limited]."

He added that the instruments could be used to monitor any region of the world prone to wildfires.

"While my study focused on southern California, the results are relevant for any shrubland ecosystem, including those in Australia and southern Europe," Professor Roberts told BBC News.

"The exact form of the relationship we use might differ, but the general approach is valid."

Researchers are using the data to develop fire spread computer models, which also draw on meteorological data to predict where flames will travel.

In the future, they hope to be able to map the severity of fires in order to improve understanding of the environmental impact, and how much carbon dioxide is released into the atmosphere.