Monitoring near real-time evapotranspiration using SEBAL®: an operation tool for water agencies/growers
Date
2010-03
Authors
Lal, Deepak, author
Clark, Byron, author
Thoreson, Bryan, author
Davids, Grant, author
Bastiaanssen, Wim, author
U.S. Committee on Irrigation and Drainage, publisher
Journal Title
Journal ISSN
Volume Title
Abstract
The Surface Energy Balance Algorithm for Land (SEBAL®) is used worldwide to estimate actual evpotranspiration (ET) at different spatial scales (individual fields to entire basins) and temporal scales (water year, growing season, individual day, etc.). SEBAL has been successfully applied on various surface types including crops, riparian, natural vegetation, playas, and wetlands. Comparisons of SEBAL actual ET results with reliable ground based measurements (Eddy covariance, Bowen ratio, lysimeter, water balance and scintillometer) have shown close agreement with differences ranging from 1 to 5% when compared to reliable ground-based estimates over a growing season when the model is applied by experienced operators. This paper describes near real-time application of SEBAL® (Version 2009) to produce weekly maps of actual ET, crop coefficients, and biomass production for California's Central Valley. Each week, the maps for the prior week are produced and posted to the Internet. The maps are developed using MODIS multispectral satellite imagery with an end resolution of 250 meters. This paper discusses potential application of near real time actual ET maps by water managers, water supply agencies and irrigators.
Description
Presented at Upgrading technology and infrastructure in a finance-challenged economy: a USCID water management conference held on March 23-26, 2010 in Sacramento, California.