Southern
Africa Mapping and Assessment of Biomass Burning
David Roy
Stolen from the Gods or harnessed from
nature, fire has played a central role in human history. Humans have been using
fire since at least 100,000 years ago and archeological remains in Kenya
suggest human exploitation of fire may be ancient, going back 1.6 million
years. The savannas of Africa experience the most extensive biomass burning in
the world.
The use of
fire is integral to many African agricultural practices. Fire has local to
regional impacts on land use, productivity, carrying capacity, and
biodiversity, and regional to global impacts on biogeochemical and atmospheric
processes. These impacts are both positive and negative but are not well
understood and are complicated by rapid and substantial social, economic, and
environmental changes. The frequency,
intensity, season, and type of fire that prevails are referred to as the fire
regime. How fire regimes will change as human populations, their land use
practices, and the climate changes is unclear. These changes are likely to
affect fire regimes directly, through changes in the ways fire is used, and
indirectly, by modifying the environmental conditions and the amount of fuel
available for fire.
Currently,
there are no adequate data on the size distributions, occurrence, or trends in
fire numbers or areas burned annually in southern Africa. Local fire
information exists for some national parks, forests, and conservation areas,
but is not representative of the region as a whole.
Spaceborne sensors provide a unique
perspective with which to study and understand the distribution and
characteristics of fire. In this project a change detection algorithm has been
developed to make spatially explicit maps of burned areas. The accuracy of
these dramatic new satellite maps is being evaluated by members of SAFNet.
These maps are an important step in creating a long-term fire record and are
being used to understand the timing and extent of fire in southern Africa with
the goal of predicting if and how fire regimes are changing.
->
Figure: Burned areas mapped June – October 2002 using daily Moderate Resolution Imaging
Spectroradiometer
satellite
data over 250 * 800km (Angola, Zambia, Namibia and Botswana borders are shown
in black).
The
rainbow colors show the day of burning (blue at the beginning, red at the end
of the 5 month period).
For more information contact David Roy at droy@kratmos.gsfc.nasa.gov.