For various applications in soil science, hydrology and climatology it is important to estimate soil hydraulic properties over large areas. The methods to quantify them have been of limited success so far. One of the main difficulties is the influence of soil structure on infiltration and drainage of soils. The classical soil physical methods cannot be applied because they yield local measurements of properties, which are spatially averaged over sampling volumes of soil columns but not over plots or entire fields. One way out of this dilemma may be the use of microwave radiometry to quantify the dynamics of surface water contents and use this information as a proxy variable to estimate the hydraulic properties of the underlying soil. This study reports on a field experiment conducted from April to July 2001. Beside measuring the dynamics of the water content in the topsoil by a ground-based 11.4 GHz microwave radiometer, we carried out in-situ measurements of water content, temperature and matric potential. The infiltration pattern, visualized with a blue dye tracer added to the infiltrating solution, showed that both soils were strongly susceptible to preferential flow. The changes in topsoil water content seemed to be well comparable to the changes in the measured reflectivities.

Date Published: 28 January 2002
PDF: 8 pages
Proc. SPIE 4542, Remote Sensing for Agriculture, Ecosystems, and Hydrology III, (28 January 2002); doi: 10.1117/12.454204

Published in SPIE Proceedings Vol. 4542:
Remote Sensing for Agriculture, Ecosystems, and Hydrology III
Manfred Owe; Guido D'Urso, Editor(s)