MICROWAVE BACKSCATTER AND ATTENUATION DEPENDENCE ON LEAF-AREA INDEX FOR FLOODED RICE FIELDS

Wetlands are important for their role in global climate as a source of methane and other reduced trace gases. As part of an effort to determ ine whether radar is suitable for wetland vegetation monitoring, we ha ve studied the dependence of microwave backscatter and attenuation on leaf area index (LAI) for flooded rice fields. We find that the radar return from a flooded rice field does show dependence on LAI. In parti cular, the C-band VV cross section per unit area decreases with increa sing LAI. A simple model for scattering from rice fields is derived an d fit to the observed HH and VV data. The model fit provides insight i nto the relation of backscatter to LAI and is also used to calculate t he canopy path attenuation as a function of LAI.