The transpiration (T) data component (dekadal, in mm/day) is the actual transpiration of the vegetation canopy. The value of each pixel represents the average daily actual transpiration for that specific dekad.
Data publication: 2020-01-01
Supplemental Information:
No data value: 255
Unit: mm
Conversion factor: the pixel value in the downloaded data must be multiplied by 0.1
New dekadal data layers are released approximately 5 days after the end of a dekad. A higher quality version of the same data layer is uploaded after 6 dekads have passed. This final version of the dekadal dataset has a higher quality because gap filling and interpolation processes, where needed, have been based on more data observations.
Citation:
FAO 2018. WaPOR Database Methodology: Level 3. Remote Sensing for Water Productivity Technical Report: Methodology Series. Rome, FAO. 72 pages. Licence: CC BY-NC-SA 3.0 IGO
Contact points:
Metadata Contact: WaPOR
Resource Contact: WaPOR
Data lineage:
The calculation of the transpiration is based on the ETLook model described in Bastiaanssen et al. (2012). It uses the Penman-Monteith equation, adapted to remote sensing input data. The Penman-Monteith equation predicts the rate of total evaporation and transpiration using commonly measured meteorological data (solar radiation, air temperature, vapour content and wind speed). It has become the FAO standard for calculating the actual and reference evapotranspiration (see FAO Irrigation and Drainage paper 56, Allen et al. 1998).
The following data is used for calculating transpiration:
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Daily: incoming solar radiation and weather data (temperature, humidity, wind speed and precipitation);
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Dekadal: NDVI, surface albedo and soil moisture stress;
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Seasonal: Land Cover;
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Static: Digital Elevation Model.
Data component developed through collaboration with the FRAME Consortium. More information can be found at: http://www.fao.org/in-action/remote-sensing-for-water-productivity/en/
Resource constraints:
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
Online resources:
Transpiration (Kairouan, Tunisia - Dekadal)
Download data from WaPOR Website
