Submitted to: Remote Sensing in Hydrology Symposium
Publication Type: Proceedings
Publication Acceptance Date: April 7, 2000
Publication Date: N/A
The evaporation rates and energy balance for Tamarisk vegetation along the Rio Grande in New Mexico are examined. The main objective is to generate knowledge of the key biophysical factors that control the water use by this vegetation community. Current results indicate that when foliage cover becomes large, the evaporation is often energy limited and follows near the equilibrium rate. This reflects the fairly large extent of the vegetation corridor, and low canopy conductance values. However, there are times when the evaporation is largely controlled by saturation deficit, reflected in small values of the omega or coupling factor. This is most commonly observed during the afternoons. The increase in saturation deficit during these times can result from horizontal advection of warm, dry air when winds blow across the corridor. Or it can result from the imposition of drier air from the mixed layer during the afternoon hours, when the ABL is strongly coupled to the surface. The findings will provide the direction for development of appropriate models for water use of this important ecosystem.