Vegetation change analysis on Boggy Plain, South Alligator River, using remote sensing: Report on preliminary analyses

Department of the Environment and Heritage, 2003

Internal Report 430
Boyden JM, Bayliss P, Kennett R, Christophersen P, Lawson V, McGregor S & Begg G
Supervising Scientist Division

About the report

This report outlines preliminary findings of vegetation change analyses for Boggy Plain using remote sensing. Results are presented and discussed in two parts: (1) an assessment of contemporary changes based on remotely sensed imagery collected in 2002 and 2003; and (2) an assessment of longer-term change based on interpretation of aerial photography from 1950 and 1991.

Ground surveys showed substantial changes in vegetation-habitat cover as a result of traditional dry season burning of dense Hymenachne grassland in late 2002. QuickBird™ satellite imagery provided a high-resolution product suitable for detailed vegetation cover mapping and monitoring to assess the extent and form of these vegetation changes at the scale of the whole floodplain. Image analysis indicated that fire not only reduced the extent and density of Hymenachne, thus creating an environment more desirable for hunting, but also produced a more diverse range of vegetation habitats. In contrast to Hymenachne, which was reduced by some 40%, Eleocharis sphacelata appeared to be resilient to fire, showing no discernible change in its distribution in areas that were burnt.

Longer-term vegetation cover patterns interpreted from aerial photography exhibited a number changes. Of particular note was the increase in number and long-term persistence of Buffalo swim channels.