openet-ndvi 0.0.6

Earth Engine based NDVI ET Model

This repository provides an Earth Engine Python API based implementation of a simple model for computing evapotranspiration (ET) as a linear function of NDVI.

Model Structure

Examples

Computing an ET fraction image using the Landsat C1 TOA helper method

import openet.ndvi as ndvi_et

landat_img = ee.Image('LANDSAT/LC08/C01/T1_RT_TOA/LC08_044033_20170716')
etf_img = ndvi_et.Image().from_landsat_c1_toa(landat_img).etf

The Image class can also be initialized directly from an NDVI image (the band must be called “ndvi”).

import openet.ndvi as ndvi_et

ndvi_img = ee.Image('LANDSAT/LC08/C01/T1_RT_TOA/LC08_044033_20170716')\
    .normalizedDifference(['B4', 'B5'])
etf_img = ndvi_et.Image(input_img).etf

Notebooks

Detailed Jupyter notebook examples can be found in the examples folder.

Installation

The OpenET NDVI based ET python module can be installed via pip:

pip install openet-ndvi

Dependencies

Modules needed to run the model:

• earthengine-api

• openet

OpenET Namespace Package

Each OpenET model should be stored in the “openet” folder (namespace). The benefit of the namespace package is that each ET model can be tracked in separate repositories but called as a “dot” submodule of the main openet module,

import openet.ndvi as ndvi