HR: 16:45h
AN: H42M-04    [PDF]
TI: Scaling Evapotranspiration Depletion Rates in Native and Non-native Vegetation Along the Middle Rio Grande Riparian Corridor
AU: * McDonnell, D E
EM: mcdonnel@sevilleta.unm.edu
AF: University of New Mexico Department of Biology, 167 Castetter Hall, Albuquerque, NM 87131
AU: Dahm, C N
EM: cdahm@sevilleta.unm.edu
AF: University of New Mexico Department of Biology, 167 Castetter Hall, Albuquerque, NM 87131
AU: Coonrod, J E
EM: jcoonrod@unm.edu
AF: University of New Mexico Department of Civil Engineering, Tapy Hall, Albuquerque, NM 87131
AU: Cleverly, J R
EM: cleverly@sevilleta.unm.edu
AF: University of New Mexico Department of Biology, 167 Castetter Hall, Albuquerque, NM 87131
AU: Thibault, J R
EM: jrtebo@sevilleta.unm.edu
AF: University of New Mexico Department of Biology, 167 Castetter Hall, Albuquerque, NM 87131
AB: This research uses ground-based measurements and remote sensing techniques to scale evapotranspiration (ET) estimates along the middle Rio Grande riparian corridor in central New Mexico. Previous estimates of riparian evapotranspiration (ET) along the corridor range from between 20 to 50 percent of the total water depletions. These depletions are believed to be increasing due to the invasion of non-native species. The University of New Mexico (UNM) Departments of Civil Engineering and Biology have been working to better define ET depletion values in native and non-native field plots within the riparian forest. Currently, half hourly ground based micrometeorological data are being collected using four instrumentation towers installed in native cottonwood and non-native saltcedar sites. The tower data form the basis for calculating ET at the four tower sites using the 3-D eddy covariance method. These ET values are arguably the most accurate estimates of ET available within the middle Rio Grande; however, they are limited to only four points along the 320-kilometer riverine corridor. In order to scale ET calculations to the entire corridor, we first scale ET to eight additional study sites using the relationship between Leaf Area Index and ET. This provides an adequate number of points for groundtruthing remote sensing imagery. Next we compare the Landsat 7 ETM+ imagery with the groundtruthing points and develop relational equations. These equations are applied to a vegetation classification map also derived from Landsat 7 imagery. The resulting maps allow us to quantify ET depletions for both saltcedar and cottonwood canopies.
DE: 1640 Remote sensing
DE: 1812 Drought
DE: 1818 Evapotranspiration
DE: 1836 Hydrologic budget (1655)
DE: 1851 Plant ecology
SC: Hydrology [H]
MN: 2003 Fall Meeting