Final Report - Executive Summary: This final project report is prepared to summarize the research project titled “Assessing evapotranspiration rate changes for proposed restoration of the forested uplands of the Desert Landscape Conservation Cooperatives (LCC)” for the Desert LCC of the Bureau of Reclamation as a requirement for closing out the project. This report includes the scope of work, summary of research project, results, and conclusions.
Among all of the components of the terrestrial water cycle, evapotranspiration (ET) consumes the largest amount of water. Accurate estimation of ET is very important to understand the influence of ET to the hydrologic response of recharge and runoff processes in the water cycle. Better estimations of ET will allow land and resource managers to more effectively conserve water for forest management in semi-arid regions such as Arizona. To better estimate ET, eddy covariance (EC) techniques were applied to eddy covariance derived ET data collected continuously between 2007 and 2010 Measurements of ET by EC has been known to be accurate for water flux measurement in forests.
Five meteorological models and one remote sensing-based model were used to test EC-derived data. The six selected models have been widely used for forest ET estimation. Results show that some micrometeorological models can predict ET within 30% of EC-derived ET in forests and shrub lands of the southwestern U.S. with accurate parameterization, and that remote sensing-based ET estimates need to be improved through use of higher-resolution products. The results of this study were summarized in a manuscript which is in review with the journal of Ecohydrology. We are working on analyses for the second manuscript and they will be available when we submit the manuscript for review. We are willing to share the result with the Bureau of Reclamation when it is ready.