Why is it important?

With increasing pressure on fresh water resources, and up to 70% of those resources used in crop irrigation, it is important to monitor and improve crop water use efficiency from field to national scales.

Project highlights:

Evaporanspiration maps covering Lebanon and Tunisia were produced and are available from et4fao.dhigroup.com

Covering a wide range of metocean parameters with expert assessment of quality and only including sufficiently reliable data.

Robust scientific analysis of the new evapotranspiration products and maps available from WaPOR portal is conducted.

In more detail..

The Food and Agriculture Organization (FAO), the custodian agency of SDG indicators 6.4.1 and 6.4.2, is running a portal called Water Productivity Open-access portal (WaPOR) to encourage the use of satellite data in crop water use efficiency monitoring. The WaPOR portal currently relies on Terra and Aqua, PROBA-V and Landsat satellite data, many of which are at the end of their expected lifetime. In this project we perform robust, scientific analysis of the possibility to use Copernicus data (especially observations from the Sentinel-2 and Sentinel-3 satellites) in place of the legacy satellites, to produce national maps of evapotranspiration able to capture field-scale crop water use.

The project builds upon methodologies developed during the ESA-funded Sen-ET project. During that project, a robust method was developed to estimate land-surface energy fluxes, including evapotranspiration, at field-scale using Sentinel-2 and Sentinel-3 data, despite the absence of a high-resolution thermal sensor in the Sentinel constellation. The method consisted of a machine-learning data fusion algorithm for sharpening land surface temperature measured by Sentinel-3 at 1 km to the 20 m spatial resolution of Sentinel-2, followed by a physically based modelling of land-surface energy fluxes. In ET4FAO we apply this technique to produce evapotranspiration maps covering the whole of Lebanon and Tunisia at 20 m, 100 m and 300 m spatial resolutions. Those maps are then compared against products available from the FAO WaPOR portal and validated against independent field measurements.

European Space Agency:

The project in funded by ESA as part of the EO Science for Society Open Call. It is a partnership between scientists from DHI GRAS and COMPLUTIG (Spain) with FAO acting as the main stakeholder.


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