In this exercise, we're going to learn how to map functions to an ImageCollection using WaPOR Actual Evapotranspiration and Interception data.

The actual evapotranspiration and interception (ETIa) (dekadal, in mm/day) is the sum of the soil evaporation (E), canopy transpiration (T), and evaporation from rainfall intercepted by leaves (I). The value of each pixel represents the average daily ETIa in a given dekad.

We're going to do the following steps:

  • Upload study area polygon shapefile to the Assets
  • Import the WaPOR Actual Evapotranspiration and Interception ImageCollection
  • Filter on date to get all dekades in a month
  • Create a function for the scaling factor
  • Apply the scaling function to the ImageCollection
  • Calculate the average ETIa in month
  • Calculate the total ETIa in a month
  • Clip the result to the study area feature
  • Visualise the result using a palette

Watch this video:

The code is available in this repository under Module3/Exercise3

Your task after the exercise

Modify the script of Exercise 3.3 in such a way that:

  • it uses the location of your own area of interest
  • it computes the monthly AETI for November 2020

Last modified: Monday, 19 July 2021, 3:41 PM