Combining Remote Sensing and Water-Balance Evapotranspiration Estimates for the Conterminous United States

Evapotranspiration (ET) is a key component of the hydrologic cycle, accounting for ~70% of precipitation in the conterminous U.S. (CONUS), but it has been a challenge to predict accurately across different spatio-temporal scales. The increasing availability of remotely sensed data has led to signifi...

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Main Authors: Meredith Reitz, Gabriel B. Senay, Ward E. Sanford
Format: Article
Language:English
Published: MDPI AG 2017-11-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/9/12/1181
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author Meredith Reitz
Gabriel B. Senay
Ward E. Sanford
author_facet Meredith Reitz
Gabriel B. Senay
Ward E. Sanford
author_sort Meredith Reitz
collection DOAJ
description Evapotranspiration (ET) is a key component of the hydrologic cycle, accounting for ~70% of precipitation in the conterminous U.S. (CONUS), but it has been a challenge to predict accurately across different spatio-temporal scales. The increasing availability of remotely sensed data has led to significant advances in the frequency and spatial resolution of ET estimates, derived from energy balance principles with variables such as temperature used to estimate surface latent heat flux. Although remote sensing methods excel at depicting spatial and temporal variability, estimation of ET independently of other water budget components can lead to inconsistency with other budget terms. Methods that rely on ground-based data better constrain long-term ET, but are unable to provide the same temporal resolution. Here we combine long-term ET estimates from a water-balance approach with the SSEBop (operational Simplified Surface Energy Balance) remote sensing-based ET product for 2000–2015. We test the new combined method, the original SSEBop product, and another remote sensing ET product (MOD16) against monthly measurements from 119 flux towers. The new product showed advantages especially in non-irrigated areas where the new method showed a coefficient of determination R2 of 0.44, compared to 0.41 for SSEBop or 0.35 for MOD16. The resulting monthly data set will be a useful, unique contribution to ET estimation, due to its combination of remote sensing-based variability and ground-based long-term water balance constraints.
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spelling doaj.art-e04a18ef7abc48308eb82304bb9acc342022-12-21T19:41:49ZengMDPI AGRemote Sensing2072-42922017-11-01912118110.3390/rs9121181rs9121181Combining Remote Sensing and Water-Balance Evapotranspiration Estimates for the Conterminous United StatesMeredith Reitz0Gabriel B. Senay1Ward E. Sanford2Hydrologic Remote Sensing Branch, U.S. Geological Survey, Reston, VA 20192, USAEarth Resources Observation and Science (EROS) Center, North Central Climate Science Center, U.S. Geological Survey, Fort Collins, CO 80523, USAEarth Systems Modeling Branch, U.S. Geological Survey, Reston, VA 20192, USAEvapotranspiration (ET) is a key component of the hydrologic cycle, accounting for ~70% of precipitation in the conterminous U.S. (CONUS), but it has been a challenge to predict accurately across different spatio-temporal scales. The increasing availability of remotely sensed data has led to significant advances in the frequency and spatial resolution of ET estimates, derived from energy balance principles with variables such as temperature used to estimate surface latent heat flux. Although remote sensing methods excel at depicting spatial and temporal variability, estimation of ET independently of other water budget components can lead to inconsistency with other budget terms. Methods that rely on ground-based data better constrain long-term ET, but are unable to provide the same temporal resolution. Here we combine long-term ET estimates from a water-balance approach with the SSEBop (operational Simplified Surface Energy Balance) remote sensing-based ET product for 2000–2015. We test the new combined method, the original SSEBop product, and another remote sensing ET product (MOD16) against monthly measurements from 119 flux towers. The new product showed advantages especially in non-irrigated areas where the new method showed a coefficient of determination R2 of 0.44, compared to 0.41 for SSEBop or 0.35 for MOD16. The resulting monthly data set will be a useful, unique contribution to ET estimation, due to its combination of remote sensing-based variability and ground-based long-term water balance constraints.https://www.mdpi.com/2072-4292/9/12/1181evapotranspirationwater resourcesremote sensingwater balanceevaporationtranspiration
spellingShingle Meredith Reitz
Gabriel B. Senay
Ward E. Sanford
Combining Remote Sensing and Water-Balance Evapotranspiration Estimates for the Conterminous United States
Remote Sensing
evapotranspiration
water resources
remote sensing
water balance
evaporation
transpiration
title Combining Remote Sensing and Water-Balance Evapotranspiration Estimates for the Conterminous United States
title_full Combining Remote Sensing and Water-Balance Evapotranspiration Estimates for the Conterminous United States
title_fullStr Combining Remote Sensing and Water-Balance Evapotranspiration Estimates for the Conterminous United States
title_full_unstemmed Combining Remote Sensing and Water-Balance Evapotranspiration Estimates for the Conterminous United States
title_short Combining Remote Sensing and Water-Balance Evapotranspiration Estimates for the Conterminous United States
title_sort combining remote sensing and water balance evapotranspiration estimates for the conterminous united states
topic evapotranspiration
water resources
remote sensing
water balance
evaporation
transpiration
url https://www.mdpi.com/2072-4292/9/12/1181
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AT wardesanford combiningremotesensingandwaterbalanceevapotranspirationestimatesfortheconterminousunitedstates