|AGAM, NURIT - BEN GURION UNIVERSITY OF NEGEV|
|Evett, Steven - Steve|
|Kustas, William - Bill|
Submitted to: International Irrigation Show
Publication Type: Abstract Only
Publication Acceptance Date: 8/28/2015
Publication Date: 11/10/2015
Citation: Colaizzi, P.D., Agam, N., Tolk, J.A., Evett, S.R., Oshaughnessy, S.A., Gowda, P., Kustas, W.P., Anderson, M.C. 2015. Advances in the two-source energy balance model:Partioning of evaporation and transpiration for row crops [abstract]. International Irrigation Show.
Technical Abstract: Accurate partitioning of the evaporation (E) and transpiration (T) components of evapotranspiration (ET) in remote sensing models is important for evaluating strategies aimed at increasing crop water productivity. The two-source energy balance (TSEB) model solves the energy balance of the soil-plant canopy-atmosphere continuum using surface brightness temperature. By solving the energy balance of the soil and canopy separately, the TSEB model can calculate E and T, which cannot be done with single-source models. However, few studies have tested the TSEB model where E or T measurements were available, which until recently has impeded its advance. This paper reviews recent TSEB model advances designed for row crops, where models were tested using measurements of E, T, and ET by microlysimeters, sap flow gauges, and weighing lysimeters, respectively, at Bushland, Texas, USA. Recent advances include (1) development of geometric algorithms to account for sunlit and shaded soil and canopy, which improved the accuracy of temperature partitioning, radiation partitioning, and soil heat flux calculation; (2) replacing the Priestley-Taylor with the Penman-Monteith equation to initialize and constrain the model; and (3) introduction of more suitable iterative algorithms to increase computational speed and ensure convergence to physically valid energy balance solutions. Ongoing research includes testing the TSEB with these recent advances using different remote sensing platforms, from ground-based (sub-meter) to satellite (several hundred meters) scales.