HR: 0800h
AN: H41A-0404 [Abstracts]
TI: MODIS-derived Potential Evapotranspiration Estimates for Operational Hydrologic Modeling
AU: * Kim, J
EM: jykim@seas.ucla.edu
AF: UCLA, Civil and Environmental Engineering, Los Angeles, CA 90095
AU: Hogue, T
EM: thogue@seas.ucla.edu
AF: UCLA, Civil and Environmental Engineering, Los Angeles, CA 90095
AB:
The current SACramento Soil Moisture Accounting Model (SAC-SMA), used by the National Weather Service, is the primarily model
for hydrologic forecasting across the United States. Potential evapotranspiration (PET), one of the required inputs,
remains rather simplistic. The model traditionally uses a regional pan evaporation estimate due to the difficulty in
acquiring more sophisticated measurements. This study explores an alternative methodology using only remote sensing
information to capture the monthly mean distribution of potential evapotranspiration (PET) for the SAC-SMA model. We apply a
simple scheme proposed by Jiang and Islam (2005) to estimate the net radiation and estimate PET within the context of the
Priestley-Taylor equation using data gathered from the MODIS Terra platform. PET estimates from the MODIS data are compared
with those derived from Oklahoma Mesonet ground-based measurements and traditional pan evaporation estimates. Preliminary
results will be presented for the Illinois River basin at Watts (OK) identified as part of the National Weather Service's
Distributed Modeling Intercomparison Project (DMIP). The resultant streamflow simulations will illustrate the sensitivity of
the SAC-SMA model to potential evaporation inputs from different sources and the possibility of the application of a
stand-alone PET method for un-gauged basins.
DE: 1818 Evapotranspiration
SC: Hydrology [H]
MN: Fall Meeting 2005