HR: 0800h
AN: H31D-0638    [Abstracts]
TI: Development of a Remotely-sensed Soil Heat Flux Parameterization for Natural Landscapes in Semi-arid Regions
AU: * Kim, J
EM: jykim@seas.ucla.edu
AF: UCLA, Civil and Environmental Engineering 5731F Boelter Hall, los angeles, CA 90095, United States
AU: Scott, R
EM: rscott@tucson.ars.ag.gov
AF: USDA, 2000 E. Allen road, tucson, AZ 85719, United States
AU: Hogue, T
EM: thogue@seas.ucla.edu
AF: UCLA, Civil and Environmental Engineering 5731F Boelter Hall, los angeles, CA 90095, United States
AB: Due to the difficulties in directly measuring soil heat flux (G), research on empirical estimation has moved toward use of a strong association between soil heat flux and net radiation (Rnet). The majority of these studies are concentrated on the estimation of soil heat flux from mature agricultural areas in semi-arid regions due to the high demand for irrigation water. However, natural land surfaces, the largest fraction of semi-arid and arid regions, have not been well studied with regards to soil heat flux estimation. Therefore, application of the previously developed empirical equations to natural land surfaces results in large uncertainty in soil heat flux estimates. This study explores development of an empirical relationship that is well-suited for natural landscapes within semi-arid areas in order to provide a more thorough assessment of regional evaporation (i.e. water consumption) in water-limited regions. Particularly, we seek to develop an empirical relationship between soil heat flux and net radiation when observations from the mid-day polar orbiting satellites (i.e. Terra/Aqua) are available. MODIS-derived components such as vegetation indices, albedo and surface temperature are being used to characterize this relationship over a set of flux tower sites in southern Arizona. Evaluation of existing soil heat flux schemes as well as results from validation of a new formulation suitable for use in natural landscapes within semi-arid regions will be presented.
DE: 1818 Evapotranspiration
DE: 1855 Remote sensing (1640)
DE: 1866 Soil moisture
DE: 1878 Water/energy interactions (0495)
SC: Hydrology [H]
MN: 2007 Fall Meeting