Submitted to: Remote Sensing in Hydrology Symposium
Publication Type: Proceedings
Publication Acceptance Date: April 7, 2000
Publication Date: N/A
Quantification of evapotranspiration (ET) continues to be challenging especially when attempting to evaluate at basin scales. Field or local-scale estimates over relatively uniform surfaces have become routine using standard micrometerorolgical techniques. However, extending these approaches to whole basins or larger regions is difficult due to landscape heterogeneity and scale. Reliable areal estimates of ET are essential for accurate modeling of the hydrologic cycle and for assessing water-use of different ecosystems. This is particularly critical in water-limited areas in arid and semiarid climates. A riparian corridor along the Rio Grande river dominated by the Eurasian tamarisk or salt cedar (Tamarix spp.) is being studied to determine daily and total seasonal water-use. Local estimates of ET in the Tamarix were made using eddy covariance instrumentation mounted on a 12 m tower. Radiometric temperatures at the top of the canopy and of the soil surface below the canopy were also measured using fixed-head infrared thermometers. The combination of these data will be used to validate evapotranspiration estimates along the corridor using remotely sensed data from an aircraft platform that have been acquired periodically for a large extent of the riparian zone.