Mapping irrigation-induced salinity with hyperspectral imagery

Hyperspectral imagery from the HyMap airborne scanner was used to recognize and map indicators of incipient salinization at a site in the Murray-Darling Basin, Victoria, Australia. Field-derived spectra and XRD analyses confirm the presence of halite, gypsum, bassanite and polyhalite in soils. Vegetation indicators of salinity include halophytes comprising of samphire, sea blite and several species of native grasses comprising sea barley grass, windmill grass and tall wheat grass. Image-derived and field-derived spectra are used to classify pixels and provide an accurate record of the groundcover conditions prevailing at the time of image acquisition. The spatial distribution of saline soil endmembers derived from the HyMap imagery shows a similar distribution to soil salinization mapped by ground geophysical surveys