Speaker
Description
The Lower Shire Valley floodplain in Malawi supports a protected wetland, wildlife reserves and a major sugarcane irrigation scheme. Its soils, water and vegetation are central to Sustainable Development Goals 1, 2, 6 and 13. Yet they are increasingly exposed to cyclone-driven floods, drought and anthropogenic pressure. Previous satellite sensors have been limited by cloud cover (optical sensors) and canopy attenuation (microwave sensors). The first spaceborne P-band SAR data from the ESA Biomass mission now offer a new view We present the first polarimetric characterisation of P-band scattering over this landscape. We use a quad-pol Level-1A acquisition from 24 November 2025, at the onset of the rainy season, partially processed in PyPolSARpro. We applied H/A/ᾱ decomposition with Cloude–Pottier classification, Van Zyl and Yamaguchi Y4R decompositions, and the quad-pol RVI. Surface scattering is the dominant mechanism across the study area. This reflects both the prevalence of bare soil in the landscape and the capacity of P-band to penetrate canopies and interact with the underlying surface. The dominant alpha angle remains in the surface regime even beneath closed woodland canopy, confirming penetration to the ground beneath forest, marsh and cropland. Volume scattering is the second contribution. It is associated with forest, shrubland, hectare-scale cropland and dense wetland vegetation, and separates these classes clearly from open terrain. Double-bounce returns are least prevalent and are confined principally to built-up areas. Of the parameters examined, ᾱ is the most diagnostic for discriminating bare land from vegetation. No single parameter fully resolves all vegetation cover types in isolation, though entropy shows potential. These results furnish a physical baseline for future Biomass acquisitions over the valley. The work serves as a primer for retrieval of key vegetation, water and soil parameters, including surface soil moisture, sub-canopy flood inundation and aboveground biomass.