2008 Research Highlights
Multiple Methods Quantify Forest Water Loss
Evapotranspiration (ET) must be quantified accurately so that scientists can evaluate the effects of land management and global change on water availability, stream flow, nutrient and sediment loading, and ecosystem productivity in watersheds. Scientists working with the Eastern Forest Environmental Threat Assessment Center are studying to improve estimates of forest evapotranspiration in the southern U.S. using multiple methods: direct field measurements at tree, stand, and watershed scales; and indirect modeling with computer simulation models.
A new ET model was developed that describes evapotranspiration as a function of water availability for evaporation and transpiration, potential ET demand, air humidity, and land surface characteristics. Field measurements were used for validation of several ET models at multiple scales. Studies revealed that existing formulas used to estimate the seasonal variation of water loss from forests are inadequate and offered ways to improve existing methods.
Research results are useful to land and water resources managers to better estimate water availability. Results are also useful to hydrologists for modeling the full hydrologic cycles of forested watersheds and examining hydrologic responses to land cover and climate changes at multiple spatiotemporal scales.
Contact: Ge Sun, research hydrologist, (919) 515-9498, gesun@fs.fed.us
Partners: University of Toledo, North Carolina State University, Chinese Academy of Sciences
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