Advanced search
Start date
Betweenand

Stochastic calibration of the SEBAL algorithm for variable rate irrigation prescription in subtropical climate

Grant number: 17/19398-5
Support type:Research Grants - Research Partnership for Technological Innovation - PITE
Duration: April 01, 2019 - March 31, 2021
Field of knowledge:Agronomical Sciences - Agricultural Engineering
Cooperation agreement: IBM Brasil
Principal Investigator:Marcos Vinícius Folegatti
Grantee:Marcos Vinícius Folegatti
Home Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
Company: IBM Brasil - Indústria, Máquinas e Serviços Ltda
City: Piracicaba
Assoc. researchers:Danilton Luiz Flumignan ; Fabio Ricardo Marin ; Jéfferson de Oliveira Costa ; João Paulo Francisco ; Wagner Wolff

Abstract

The spatio-temporal variation of evapotranspiration (ET) is the key to improve the water management over irrigated agricultural areas. Many remote sensing methods have been developed for mapping ET, among them, the most widely used is the Surface Energy Balance Algorithm for Land (SEBAL). However, SEBAL was developed for particular satellite sensors and images resolutions, in which functions and empirical parameters within its algorithm are corresponding to these. Therefore, the aim of this study is going to be the stochastic calibration of the SEBAL algorithm for images from unmanned aircraft vehicle (UAV) under subtropical climate. The study will be carried out in the city of Piracicaba in São Paulo state. UAV's images, meteorological data (eddy covariance, Bowen ration, and weather station), and lysimetric data will match for the UAV's campaigns, being measured in real-time. Utilizing the SEBAL algorithm is going to be estimated all the components of the energy balance and consequently the ET. Thus, the calibration is going to be done using the least squares method for residuals between the ET, observed (lysimeters, eddy covariance, and Bowen ratio) and ET, estimated by the SEBAL algorithm. The stochastic optimization method Particle Swarm Optimization (PSO) is going to be used to minimize the sum of squared deviations. The new parameters empirical of the SEBAL algorithm are going to be obtained in uncertainty levels and may be used to compose the variable rate irrigation (VRI) prescription and to understand the spatial variability of water stress, helping the farmers on decision-making and yield increase. (AU)