Remote sensing of vegetation and flooding on Magela Creek Floodplain (Northern Territory, Australia) with the SIR-C synthetic aperture radar

Abstract

The potential of using synthetic aperture radar (SAR) imagery to study seasonal variations in floodplain inundation and accompanying changes in herbaceous plant communities was assessed for aquatic environments in the Kakadu region of northern Australia. Dual wavelength (C- and L-band), co- and cross-polarized (HH and HV) SAR imagery of the floodplain of Magela Creek, a tributary of the East Alligator River, was acquired in April and October 1994 during the Spaceborne Imaging Radar-C (SIR-C) missions of the Space Shuttle. The results indicate the effectiveness of multifrequency, polarimetric SAR as follows: woody and herbaceous vegetation in flooded and nonflooded states can be mapped. Aquatic, herbaceous macrophyte communities, such as Nelumbo nucifera, Pseudoraphis grassland and Hymenachne-Eleocharis swamp, can be distinguished. Phenologic changes in macrophyte communities between April and October are apparent. The similarity of the Magela floodplain to the extensive floodplains in northern Australia suggests that these results can be extended regionally.