Comparison of ET from two remote sensing-based surface energy models in south central Nebraska

O. Z. Akasheh, A. Irmak, S. Irmak, I. Ratcliffe, R. Singh, P. Ranade, P. H. Gowda

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Quantification of crop water use through evapotranspiration (ET) is very important for water resources management and irrigation scheduling. Two energy balance approaches were applied to estimate ET in south central Nebraska: (1) Mapping EvapoTranspiration at high Resolution with Internal Calibration (METRIC), and (2) Simplified Surface Energy Balance (SSEB) model. While both use remotely sensed thermal data for estimating ET, the METRIC is much more complex than the SSEB and widely used in the USA. Both ET models use the hot and cold pixel approach for scaling ET between driest and wettest pixels within an agricultural setting. Four Landsat 5 and four Landsat 7 images acquired for the 2007 growing season over path 29/row 32 were used to produce instantaneous ET. Images were selected with the least cloud cover and distributed temporally to cover different crop growth stages. ET data measured with a Bowen ratio energy balance system was used to assess the estimated ET accuracy. Statistical comparison of estimated daily ET against observed data gave an r2 of 0.73 and 0.66 for METRIC and SSEB, respectively. Both models produced the same root mean square error of 1.5 mm/d or 35% of the observed average daily ET. However, statistical comparison between METRIC and SSEB-based ET gave an r 2 of 0.96, indicating that SSEB performance is comparable to METRIC. Considering the minimal amount of ancillary data required for implementation and excellent performance in predicting daily ET, the SSEB approach is a promising tool for mapping ET.

Original languageEnglish (US)
Title of host publicationRemote Sensing and Hydrology
Pages106-110
Number of pages5
StatePublished - 2012
EventRemote Sensing and Hydrology Symposium - Jackson Hole, WY, United States
Duration: Sep 27 2010Sep 30 2010

Publication series

NameIAHS-AISH Publication
Volume352
ISSN (Print)0144-7815

Conference

ConferenceRemote Sensing and Hydrology Symposium
Country/TerritoryUnited States
CityJackson Hole, WY
Period9/27/109/30/10

All Science Journal Classification (ASJC) codes

  • Earth and Planetary Sciences(all)

Cite this