'Assessing the Sensitivity of Two Source Energy Balance Model to Different Soil and Canopy Boundary Resistances Using High Resolution UAV Data under Complex Canopy Environments'
Poster |
Poster: |
Evapotranspiration (ET) is a key variable for irrigation water management. The advent of UAV technology with similar sensor technology as satellite’s allows nowadays for the estimation of high-resolution ET. Among the different models are used to estimate ET at high resolution the most commonly used is known as the Two Source Energy Balance Model (TSEB). TSEB is a physically-based model developed to describe the aerodynamic fluxes involved in complex interaction between soil, canopy and atmosphere. An array of key factors, including soil and canopy temperature, leaf area index, fractional cover, canopy width to height ratio, and canopy height are required as inputs for the model to parameterize the radiative and convective flux exchanges between soil and canopy. The TSEB model has implemented three different boundary resistance models including Kustas and Norman 1999, Choudhury 1988, and McNaughton 1995. However, according to literature, the sensitivity of ET to these resistance models is unknown. In this study, high resolution multispectral and thermal UAV at different times of day in multiple seasons are used to identify the sensitivity of ET to boundary resistance models. Data were collected during multiple years and times by the Utah State University AggieAir over vineyard located near Lodi, California. Landsat-harmonized optical along with atmospherically calibrated thermal imagery data from UAV at 10 cm and 60 cm is used. Comparison of boundary resistance estimates for different times of the day and seasons as well as their impact in the estimation of ET against ground measurements will be presented and discussed. |
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