Remote sensing of evapotranspiration for water management in Brazil

 

Our goal

Provide consistent estimates of evapotranspiration using multi-models, multi-source and multi-scale based on remote sensing data for water management in Brazil, through an open and user-friendly platform named ET Brasil.

Our motivation

Evapotranspiration, defined as the sum of evaporation and vegetation transpiration leaving the surface and entering the atmosphere as water vapor, is a key process in the terrestrial water, carbon, and energy cycles. In the current scenarios of land cover changes associated with deforestation, fire occurrences and increasing agricultural areas in the tropics, monitoring surface energy fluxes and evapotranspiration using novel remote sensing technologies is a fundamental requirement to assess changes in the water cycle and the effects of large-scale surface– atmospheric interactions. Evapotranspiration is also an essential information for water resources management, supporting decision-making to improve water security and for better allocation of water use in agricultural lands.

Our project

New technologies and high-performance computing have significantly improved water resources applications based on remote sensing data and models. Our research group
is able to generate evapotranspiration estimates at multiple scales (from field to large scale), using multiple data sources (from Landsat to MODIS images) and multiple models driven by surface temperature, using the Google Earth Engine cloud computing platform. We also use measured data across the country for model calibration and validation, allowing us to adjust widelyused global models to tropical and subtropical climates.
Before public release, our evapotranspiration estimates are submitted to peer-reviewed and high-impact journals, given scientific status and reliability to the datasets.

User-friendly Earth Engine application (geeSEBAL) 

Available at  https://etbrasil.org/geesebal

 

Research applications and case studies

Based on evapotranspiration estimates from multi-source and multi-scale remote sensing data, we focused in several research applications in Brazil, including the assessment of the impacts of deforestation in the Amazon on surface-atmosphere water fluxes and agricultural water use for irrigation in Brazil, using current and historical Landsat images since 1984 to present.

Impacts of deforestation on surface energy balance in the Amazon Arc of Deforestation

 

 

 

 

 

 

 

 

Mapping cropland expansion and agricultural water use in Brazil

 

 

 

 

 

 

 

 

 

Our research team and partners

Our research team is formed by researchers in Hydrology, Remote Sensing and Water Resources Engineering. Our team is part of the Large-Scale Hydrology (HGE) research group, hosted at the Institute of Hydraulic Research (IPH), as part of the Federal University of Rio Grande do Sul (UFRGS), Brazil.

The HGE team:

Our main funding agencies include the Brazilian Water Agency (ANA), the National Council for Scientific and Technological Development (CNPq) and the Coordination for the Improvement of Higher Education Personnel (CAPES), with in-kind support from the Google Earth Engine team and many other national and international institutions.