HR: 11:20h
AN: H21H-05 [PDF]
TI: Defining Parameters from NOAAA AVHRR Imagery to Map Regional ET
AU: * Doraiswamy, P C
EM: pdoraisw@hydrolab.arsusda.gov
AF: U.S. Department of Agriculture, 10300 Baltimore Ave
Hydrology and Remote Sensing Lab., Beltsville, MD 20705 United States
AU: Pruger, J
EM: prueger@nstl.gov
AF: U.S. Department of Agriculture, 2150 Pammel Drive Ames
National Soil Tilth Laboratory, Ames, IA 50011 United States
AU: Kustas, W
EM: bkustas@hydrolab.arsusda.gov
AF: U.S. Department of Agriculture, 10300 Baltimore Ave
Hydrology and Remote Sensing Lab., Beltsville, MD 20705 United States
AU: Akhmedov, B
EM: akhmedov@hydrolab.arsusda.gov
AF: U.S. Department of Agriculture, 10300 Baltimore Ave
Hydrology and Remote Sensing Lab., Beltsville, MD 20705 United States
AB:
An Agrometeorological model (MAGRET) was developed to solve the energy balance over vegetated surfaces. The magnitude of
surface temperature for grass and crops is the result of the energy balance and infers to the state of its water stress. The
sensible (H) and latent heat fluxes (ET) are computed using the classical equations of turbulent transfer. Soil heat flux
and temperature profiles in the soil computed using the Fourier equation. Solving the energy balance equation at hourly time
step, net radiation, sensible, soil, Latent heat fluxes and surface temperature were derived. Model inputs are hourly and
daily climatic data and parameters that describe the properties of soil and vegetation. The objective of this research is to
combine the combine the model with parameters derived from NOAA AVHRR satellite for determining the evapotranspiration in
regional scale. The surface temperature obtained from satellite is used to define the model parameters at meteorological
stations by comparing surface temperature obtained from model and temperature obtained from the satellite. Comparing the
model predicted surface temperature with satellite surface temperature, energy balance parameters are adjusted. The model
was evaluated as part of the Southern Great Plains hydrology experiment (SGP97) during July in central Oklahoma over the
predominantly grassland areas. The model was calibrated with data from four ET flux station and the results scaled up to the
surround region. Results from the study show a good potential use of the MAGRET model for assessment of regional ET in
agricultural areas.
DE: 1812 Drought
DE: 1818 Evapotranspiration
SC: Hydrology [H]
MN: 2003 Fall Meeting