Stima del contenuto d'acqua della vegetazione tramite osservazioni iperspettrali

This study examines the role of leaf reflectance and the airborne Multispectral Infrared and Visible Imaging Spectrometer (MIVIS) reflectance data for mapping canopy water content in a poplar plantation sited in the Ticino Natural Park (Italy). A series of water spectral indices have been investigated by using two different regression models (Ordinary Least Square and Reduced Major Axis) in order to determine the equivalent water thickness (EWT) and the fuel moisture content (FMC) at leaf and canopy level. Significant correlations were found between FMC and selected vegetation indices, but statistically stronger relationships were found with EWT using the Reduced Major Axis technique rather than the Ordinary Least Squares. The canopy structure (Leaf Area Index) was identified as the main source of signal variation in the MIVIS reflectance indices studied. However, spectral indices sensing canopy water content appear to respond not only to canopy structure but also to the canopy water, providing a useful method for mapping the vegetation water content at the experimental site.