HR: 1340h
AN: H33E-0508    [Abstracts]
TI: EFFECT OF SCALING TRANSFER BETWEEN EVAPOTRANPIRATION MAPS DERIVED FROM LANDSAT7 AND MODIS IMAGES
AU: * Hong, S
EM: hong@nmt.edu
AF: New Mexico Tech, 801 Leroy place, Socorro, NM 87801 United States
AU: Hendrickx, J M
EM: hendrick@nmt.edu
AF: New Mexico Tech, 801 Leroy place, Socorro, NM 87801 United States
AU: Borchers, B
AF: New Mexico Tech, 801 Leroy place, Socorro, NM 87801 United States
AB: Remotely sensed images of the Earth's surface provide information about the spatial distribution of evapotranspiration. Since, the spatial resolution of evapotranspiration predictions depends on the sensor type; scaling transfer between images of different scales needs to be investigated. In this study, the Surface Energy Balance Algorithm for Land (SEBAL) was used to derive evapotranspiration maps from Landsat7 Thematic Mapper (TM) and Moderate Resolution Imaging Spectroradiometer (MODIS) images. LandSat7 has a spatial resolution of 60 m, MODIS of 1000 m. Two up-scaling procedures are evaluated. The first consists of averaging 60 by 60 m LandSat pixels of spectral radiances or of intermediate SEBAL input surface parameters (albedo, NDVI, surface temperature) to obtain 1000 by 1000 m pixels at the MODIS scale before SEBAL is applied. The second consists of first applying SEBAL and then to average from 60 m to 1000 m spatial resolution. The averaging process (aggregation) will include calculating arithmetic and geometric means. In the downscaling process (MODIS to LandSat), an earlier LandSat image will be used to characterize the fine scale variability within the large MODIS pixels. Two down-scaling procedures are evaluated. The first consists of downscaling the original MODIS spectral data; the second of downscaling the evapotranspiration maps at MODIS scale. The objective of this study is to investigate the effect of the scaling transfer processes on the spatial distribution of evapotranspiration in arid riparian areas.
DE: 1800 HYDROLOGY
DE: 1818 Evapotranspiration
DE: 1836 Hydrologic budget (1655)
DE: 1866 Soil moisture
DE: 1878 Water/energy interactions
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting