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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Hydrology and Remote Sensing Laboratory » Research » Publications at this Location » Publication #312276
Title: Utility of an automated thermal-based approach for monitoring evapotranspiration

Author
item TIMMERMANS, W.J. - Collaborator
item Kustas, William - Bill
item ANDREU, A. - Collaborator

Submitted to: Acta Geophysica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2015
Publication Date: 9/23/2015
Citation: Timmermans, W., Kustas, W.P., Andreu, A. 2015. Utility of an automated thermal-based approach for monitoring evapotranspiration. Acta Geophysica. doi:10.1515/acgeo-2015-0016.

Interpretive Summary: Estimating evapotranspiration (ET) from field to watershed scale is critical for monitoring water use and plant stress of agricultural and natural vegetation and the resulting impacts on water resources and crop yield. Satellite remote sensing offers the potential for mapping ET and vegetation stress over large areas. A very simple fully automated remote sensing-based ET model that uses land surface temperature is developed and tested with ground truth data from field experiments in agricultural and natural ecosystems. Model output of ET is found to be in satisfactory agreement with tower-based ET observations and a more physically-based remote sensing model, except under dry and partial canopy cover conditions. This suggests that the simple model has utility in identifying relative water use and as an operational tool can provide initial estimates of ET anomalies in data-poor regions that would be confirmed using more robust modeling techniques. This information is very useful to Foreign Agriculture Service and other national and international agencies monitoring crop conditions and water resources, particularly in third world countries where often water and food are limited.

Technical Abstract: A very simple remote sensing-based model for water use monitoring is presented. The model acronym DATTUTDUT, (Deriving Atmosphere Turbulent Transport Useful To Dummies Using Temperature) is a Dutch word which loosely translates as “It’s unbelievable that it works”. DATTUTDUT is fully automated and only requires a surface temperature map, making it simple to use and providing a rapid estimate of spatially-distributed fluxes. The algorithm is first tested over a range of environmental and land-cover conditions using data from four short-term field experiments and then evaluated over a growing season in an agricultural region. Flux model output is in satisfactory agreement with observations and established remote sensing-based models, except under dry and partial canopy cover conditions. This suggests that DATTUTDUT has utility in identifying relative water use and as an operational tool providing initial estimates of ET anomalies in data-poor regions that would be confirmed using more robust modeling techniques.