Second EARSeL Workshop on Imaging Spectroscopy, Enschede, 2000_____________ ASSESSING OF SOIL CRUSTING PROCESS IN A SEMIARID ENVIRONMENT, USING SOIL REFLECTANCE SPECTROSCOPY IN THE SWIR REGION

The structural crust, a thin layer that is formed on the soil surface after rainstorm events, has been spectrally studied across the SWIR region. The crust is the result of a physical segregation and rearrangement of soil particles in a form that affects some of the soil’s physical properties, such as infiltration, runoff and soil erosion. In this study, a controlled spectral investigation of the structural crust across the SWIR spectral region was carried out, using clayey soils from Israel (Grumusol, typic chromoxerets). A subset of soil samples were treated in such a way that each sample was subjected to an increased level of cumulative energy from a simulated rainstorm. The result was a set of soil samples with increased levels of crusting and, respectively, with reduced infiltration rates. The spectral parameter of this set was studied in the laboratory across the SWIR region, using a Quantum 1200 spectrometer. Empirical relationships were found between infiltration rates and reflectance spectra properties and the suggestion to use the relationship as a tool for rapid, nondestructive, in situ crust assessment was raised.