compute FVC

Import libraries¶

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import ee
import geemap

import ee import geemap

Create an interactive map¶

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Map = geemap.Map(center=[40, -100], zoom=4)

Map = geemap.Map(center=[40, -100], zoom=4)

Add Earth Engine Python script¶

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# Add Earth Engine dataset
image = ee.Image("USGS/SRTMGL1_003")

#
'Author': Sofia Ermida (sofia.ermida@ipma.pt; @ermida_sofia)

This code is free and open.
By using this code and any data derived with it,
you agree to cite the following reference
'in any publications derived from them':
Ermida, S.L., Soares, P., Mantas, V., Göttsche, F.-M., Trigo, I.F., 2020.
    Google Earth Engine open-source code for Land Surface Temperature estimation from the Landsat series.
    'Remote Sensing, 12 (9), 1471; https':#doi.Org/10.3390/rs12091471

this function computes the Fraction of Vegetation Cover from NDVI
the compute_NDVI.js function must be called before this one

'to call this function use':

FVCfun = require('users/sofiaermida/landsat_smw_lst:modules/compute_FVC.js')
ImagewithFVC = FVCfun.addBand(landsat)(image)
or
collectionwithFVC = ImageCollection.map(FVCfun.addBand(landsat))

'USES':
    - SMW_coefficients.js

'INPUTS':
        '- landsat': <string>
                  the Landsat satellite id
                  'valid inputs': 'L4', 'L5', 'L7' and 'L8'
        '- image': <ee.Image>
                image for which to calculate the FVC
'OUTPUTS':
        - <ee.Image>
          'the input image with 1 new band':
          'FVC': fraction of vegetation cover
#
def exports.addBand(landsat):
  def wrap(image):

    ndvi = image.select('NDVI')

    # Compute FVC
    fvc = image.expression('((ndvi-ndvi_bg)/(ndvi_vg - ndvi_bg))**2',
      {'ndvi':ndvi,'ndvi_bg':0.2,'ndvi_vg':0.86})
    fvc = fvc.where(fvc.lt(0.0),0.0)
    fvc = fvc.where(fvc.gt(1.0),1.0)

    return image.addBands(fvc.rename('FVC'))

  return wrap

# Add Earth Engine dataset image = ee.Image("USGS/SRTMGL1_003") # 'Author': Sofia Ermida (sofia.ermida@ipma.pt; @ermida_sofia) This code is free and open. By using this code and any data derived with it, you agree to cite the following reference 'in any publications derived from them': Ermida, S.L., Soares, P., Mantas, V., Göttsche, F.-M., Trigo, I.F., 2020. Google Earth Engine open-source code for Land Surface Temperature estimation from the Landsat series. 'Remote Sensing, 12 (9), 1471; https':#doi.Org/10.3390/rs12091471 this function computes the Fraction of Vegetation Cover from NDVI the compute_NDVI.js function must be called before this one 'to call this function use': FVCfun = require('users/sofiaermida/landsat_smw_lst:modules/compute_FVC.js') ImagewithFVC = FVCfun.addBand(landsat)(image) or collectionwithFVC = ImageCollection.map(FVCfun.addBand(landsat)) 'USES': - SMW_coefficients.js 'INPUTS': '- landsat': the Landsat satellite id 'valid inputs': 'L4', 'L5', 'L7' and 'L8' '- image': image for which to calculate the FVC 'OUTPUTS': - 'the input image with 1 new band': 'FVC': fraction of vegetation cover # def exports.addBand(landsat): def wrap(image): ndvi = image.select('NDVI') # Compute FVC fvc = image.expression('((ndvi-ndvi_bg)/(ndvi_vg - ndvi_bg))**2', {'ndvi':ndvi,'ndvi_bg':0.2,'ndvi_vg':0.86}) fvc = fvc.where(fvc.lt(0.0),0.0) fvc = fvc.where(fvc.gt(1.0),1.0) return image.addBands(fvc.rename('FVC')) return wrap

Display the interactive map¶

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Map

Map