The synergy of optical data with microwave backscattering model for the retrieval of soil and vegetation conditions in heterogeneous Mediterranean environment

Estimation of soil moisture and vegetation biomass over wide regions is needed for a better understanding of ecological conditions and for monitoring desertification processes in fragile environments such as the Mediterranean region. Satellite remote sensing, with appropriate processing, could be very well suited for this task. In this work, we provide a multi-temporal analysis of backscatter characteristics of four major vegetation formations in Mediterranean regions. This analysis together with a description of the relationship between volumetric soil moisture and ERS-2 SAR data from Mediterranean soils enabled us to adapt the water-cloud model of Attema and Ulaby (1978) to Mediterranean vegetation canopies. The application of the adapted model in heterogeneous plots was possible by the use of vegetation formation pixel fractions from Landsat TM data. The results have shown considerably good agreement between predicted and measured green biomass in both homogenous and heterogeneous plots.