ARS | Publication request: Combining a two-sourcepatch model with satellite data to monitor daily evapotranspiration at a regional scale

Submitted to: International Geoscience and Remote Sensing Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 5, 2008
Publication Date: November 20, 2008
Citation: Sanchez, J.M., Caselles, V., Kustas, W.P., Scavone, G., Valor, E., Coll, C., Mira, M. 2008. Combining a two-source patch model with satellite data to monitor daily evapotranspiration at a regional scale. In: Proceedings of the International Geoscience and Remote Sensing Symposium, July 7-8, 2009, Boston, Massachussetts. III:887-890.

Technical Abstract: In this work, we present a micro-meteorological approach for estimating surface energy fluxes that can be operationally used together with satellite images to monitor surface energy fluxes at a regional scale. In particular we will focus on the retrieval of daily evapotranspiration. The feasibility of the model is explored at a local scale using data collected over a maize crop in Beltsville, Maryland, USA, and a boreal forest in Finland. Comparison of the results with ground measurements shows errors between ±15 and ±50 W m-2 for the retrieval of net radiation, soil heat flux, and sensible and latent heat fluxes in both sites. A methodology to apply the model to Landsat imagery is presented. Finally, we show its application to three different Landsat scenes covering the whole Basilicata region (Southern Italy). Maps of daily evapotranspiration are generated. Results are compared with some ground measurements. Accuracy close to ±1 mm/day is obtained.