By Jeremy Russell-Smith, Bushfires Council of the
Northern Territory & Tropical Savannas CRC
Fire research in the VRD
The Natural Heritage Trust (NHT) and the Tropical Savannas CRC
have funded a regional study on fire management in the VRD that has
already led to changes in the way fire is managed in the District.
This has only been possible through cooperation from a wide range
of people and organisations, and more importantly, through the
active encouragement and participation of the Bushfires Regional
Council and land managers in the VRD.
The study first ignited interest in the district when historical
photos of the area taken back in the early 1900s were compared with
current scenes showing an apparent increase in woody vegetation.
Interviews with landholders and further comparison of aerial
photography confirmed initial impressions and indicated that in
some areas a 30% increase in vegetation cover had occurred. Such a
thickening of vegetation obviously has a range of implications for
natural resource management, some of which are being explored by
other Tropical Savannas CRC projects.
Use of remote sensing technology
Much more recent technology is being used, however, to develop a
picture of how past fire management practices have impacted on
savanna ecology. Satellite information dating back to 1983 is being
used to develop a fire history map over most of the VRD. This
mapping has shown that pastoral country in the district has been
subject to very little burning, while rugged sandstone country has
in some cases been burnt up to eight times in 15 years.
Unfortunately, much sandstone vegetation (especially where it
comprises healthy shrubs) is sensitive to too frequent burning.
Work undertaken so far indicates that different management
practices will need to be adopted in the future to conserve these
Fire frequency for Bradshaw Field Training Area (formerly Bradshaw
Detailed fire mapping has been undertaken for the Department of
Defence on the Bradshaw Field Training Area. Both this and more
general regional mapping have been undertaken mainly using LANDSAT
Multi-Spectral Scanner (MSS) satellite data that is fairly detailed
in nature but which only passes over the Earth every nine days.
Information from the LANDSAT Thematic Mapper and NOAA AVHRR
(National Oceanic and Atmospheric Administration—Advanced
Very High Resolution Radiometer) devices has also been used. The
latter has a more coarse resolution, but gathers information on a
daily basis. It is particularly useful for finding thermal
'hot-spots' (active fires) and therefore has potential for locating
fires before they spread large distances or become
Another element of the VRD regional study is an investigation
into curing rates and how field-based indications of available fuel
loads, curing rates and fire risk can be related to estimations
derived from NOAA satellite data. So far, the correlations look
very promising and may enable the development of a satellite-based
assessment of regional fire risk.
Broader land management applications
A range of projects is nearing completion within the district
focusing on different aspects of fire management. This includes
field-based studies that explore the relationship between fire and
pasture development and the impacts of fire on vertebrate and
invertebrate fauna. In total, there are about 200 fire monitoring
plots within the VRD that are being used for a variety of related
projects. In addition, a modelling approach is being used to
simulate the trade-off between fire and grazing and to develop a
better regional understanding of long-term vegetation dynamics.
While the findings of each of these projects will have
implications for smaller scale fire management, they will also
contribute to a regional assessment of the costs and benefits
associated with various fire regimes. This will in turn contribute
to the development of strategic guidelines for improved fire
management in the district that completed by the end of 2001.
To view and make your own fire history maps of the VRD, click
on the link to our Savanna Map Maker on this page.
Fire management in the VRD The TS–CRC and the Bushfires Council of the NT have released a CD–ROM on fire management in the VRD and Sturt Plateau region It features satellite maps grassy fuel load management impacts… [read more...
Managing for Healthy Country in the VRD
THIS TS–CRC book brings together a range of research findings relevant to the Victoria River District—which covers an area of more than 125,000 km 2 about 500 km south of Darwin—and gives recommendations for on-ground land management.