TS-CRC Student project - Spectral, spatial and temporal analysis of the noxious weed mimosa pigra on the coastal floodplains of the Northern Territory

Northern Territory University, Darwin


Greg Lyons


Summary | Aims | Research Methods |


Mimosa pigra is a noxious woody weed invading the coastal floodplains of Northern Australia. A prolific producer of floating seeds, it forms dense strands that render large areas of floodplain inaccessible to people, cattle and native fauna. Mimosa invades grassland communities on open floodplains and forms dense areas on inaccessible, monospecific shrubland up to 6m in height. By 1997 it had a range of spread from the Fitzmaurice River near the Western Australia border, to the Roper River area on the Gulf of Carpentaria. Investigation of the spectral signal characteristics of Mimosa with a spectral radiometer will assist in discrimination of the weed in satellite remote sensing images.

Analysis of spatial distribution in combination with vegetation and soil data will determine if Mimosa preferentially invades particular habitats. This would assist in identifying areas at risk of invasion from Mimosa pigra.

Temporal analysis of the spread of mimosa will assist in forecasting infestation size in the absence of control programs.


  • Using a Spectral Radiometer, investigate the electromagnetic spectral characteristics of Mimosa pigra.
  • Use the spectral signal to discriminate Mimosa pigra in remotely sensed images.
  • Using Remote Sensing, GIS and historical data, produce a temporal analysis of the spread of Mimosa pigra on the floodplains of the Northern Territory.

Research methods

Methodology will be devised after discussion with Dr Waqar Ahmad and Dr Garry Cook and will be dependant on the equipment and data resources identified in the first stage of the project. A spectral radiometer will investigate the spectral characterisitics of Mimosa in an area of dense, monospecific mimosa. These results will then be applied to Satellite imagery using the ERDAS IMAGINE Remote Sensing package.

Historical data will be entered into a GIS software package to determine the rate and location of the spread of Mimosa pigra. This data will be added to available soil and vegetation data in an attempt to define the preferred habitat for rapid spread.