# Evapotranspiration

Earth Observation-based regional Evapotranspiration estimation

Obtaining accurate and frequent estimates of the evapotranspiration of the land surface is complicated. Many factors such as land cover, vegetation type,  humidity, and wind speed determine the evaporative power of the atmosphere and at which magnitude vegetation can transpire water from its’ leaves. In the well-known Penman-Monteith equation the actual evapotranspiration is estimated using both climatic as well as vegetation factors. Nowadays with regular satellite observations available in combination with down-scaled climatically data, the potential and actual evapotranspiration can be estimated at a fine resolution. In the five presentations, the method and the procedure to come to evapotranspiration estimates is explained.

Description

Type

1

Lesson 1: Reference, potential and actual evapo-transpiration

Gives the principles of water demand and use by vegetation.

presentation

2

Lesson 2: The energy balance and the Penman-Monteith equation

Explains the details of the energy balance equation - governing the evapotranspiration and links it with the widely used Penman-Monteith equation for computing water evaporation from vegetated surfaces.

presentation

3

Lesson 3: The calculation of the FEWS-NET ETp product

Explains the method and data source the Famine Early Warning System uses to calculate the reference ET.

presentation

4

Lesson 4: The calculation of the LANDSAF ETA product

Explains how MSG-based product of the actual transpiration is calculated on the basis of land cover, radiation and meteo data.

presentation

5

Lesson 5: Downscaling of satellite ET-actual and ET-potential products

For the ETa app a downscale procedure is applied which is described here.

presentation

6

The EUMETSAT Satellite Application Facility on Land Surface Analysis (LSA SAF) Product User Manual on Evapotranspiration

manual

7

Guidelines for the Remote Sensing of Evapotranspiration

A book chapter that discusses the energy balance method for remote sensing of evapotranspiration.

book chapter

8

Technical report on ET and SWI app available in HYDRONET

Evapotranspiration and Soil Water Index derived using the GEONETCast and ISOD toolboxes.

report