Evaluation of MODIS for groundcover and biomass/feed availability estimates in tropical savanna systems

Summary

This project has developed a remote sensing index for monitoring bare ground  in all seasons over tropical savannah grasslands at a spatial resolution of 1 km. The MODIS bare ground index (ModBGI) was developed over the Charters Towers Landsat TM scene area. It uses data from combined AM and PM overpasses of the MODerate Resolution Imaging Spectroradiometers (MODIS) on board the Terra and Aqua satellites and was established using a Landsat TM ground cover product. The ModBGI model is sufficiently robust and stable to return meaningful results in all seasons. At 1 km the ModBGI index is useful at a catchment and regional planning scale but is of limited use at the paddock/property scale. A biomass model was developed using field data collected from 31 sites during April 2004/5/6 and October 2004/5 and sun angle corrected MODIS data. The biomass model requires more field validation to properly assess its accuracy and suitability to provide stand alone products. It is of interest from a research perspective and with further development could become a source of calibration for existing models such as AussieGRASS.