F47c Checkpoint

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")

#  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#  Chapter:      F4.7 Interpreting Time Series with CCDC
#  Checkpoint:   F47c
#  Authors:      Paulo Arévalo, Pontus Olofsson
#  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

palettes = require('users/gena/packages:palettes')

resultsPath =
    'projects/gee-book/assets/F4-7/Rondonia_example_small'
ccdResults = ee.Image(resultsPath)
Map.centerObject(ccdResults, 10)
print(ccdResults)

# Select time of break and change probability array images.
change = ccdResults.select('tBreak')
changeProb = ccdResults.select('changeProb')

# Set the time range we want to use and get as mask of
# places that meet the condition.
start = 2000
end = 2021
mask = change.gt(start).And(change.lte(end)).And(changeProb.eq(
1))
Map.addLayer(changeProb, {}, 'change prob')

# Obtain the number of breaks for the time range.
numBreaks = mask.arrayReduce(ee.Reducer.sum(), [0])
Map.addLayer(numBreaks, {
    'min': 0,
    'max': 5
}, 'Number of breaks')

# Obtain the first change in that time period.
dates = change.arrayMask(mask).arrayPad([1])
firstChange = dates \
    .arraySlice(0, 0, 1) \
    .arrayFlatten([
        ['firstChange']
    ]) \
    .selfMask()

timeVisParams = {
    'palette': palettes.colorbrewer.YlOrRd[9],
    'min': start,
    'max': end
}
Map.addLayer(firstChange, timeVisParams, 'First change')

# Obtain the last change in that time period.
lastChange = dates \
    .arraySlice(0, -1) \
    .arrayFlatten([
        ['lastChange']
    ]) \
    .selfMask()
Map.addLayer(lastChange, timeVisParams, 'Last change')

# Get masked magnitudes.
magnitudes = ccdResults \
    .select('SWIR1_magnitude') \
    .arrayMask(mask) \
    .arrayPad([1])

# Get index of max abs magnitude of change.
maxIndex = magnitudes \
    .abs() \
    .arrayArgmax() \
    .arrayFlatten([
        ['index']
    ])

# Select max magnitude and its timing
selectedMag = magnitudes.arrayGet(maxIndex)
selectedTbreak = dates.arrayGet(maxIndex).selfMask()

magVisParams = {
    'palette': palettes.matplotlib.viridis[7],
    'min': -0.15,
    'max': 0.15
}
Map.addLayer(selectedMag, magVisParams, 'Max mag')
Map.addLayer(selectedTbreak, timeVisParams, 'Time of max mag')

#  -----------------------------------------------------------------------
#  CHECKPOINT
#  -----------------------------------------------------------------------

# Add Earth Engine dataset image = ee.Image("USGS/SRTMGL1_003") # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # Chapter: F4.7 Interpreting Time Series with CCDC # Checkpoint: F47c # Authors: Paulo Arévalo, Pontus Olofsson # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ palettes = require('users/gena/packages:palettes') resultsPath = 'projects/gee-book/assets/F4-7/Rondonia_example_small' ccdResults = ee.Image(resultsPath) Map.centerObject(ccdResults, 10) print(ccdResults) # Select time of break and change probability array images. change = ccdResults.select('tBreak') changeProb = ccdResults.select('changeProb') # Set the time range we want to use and get as mask of # places that meet the condition. start = 2000 end = 2021 mask = change.gt(start).And(change.lte(end)).And(changeProb.eq( 1)) Map.addLayer(changeProb, {}, 'change prob') # Obtain the number of breaks for the time range. numBreaks = mask.arrayReduce(ee.Reducer.sum(), [0]) Map.addLayer(numBreaks, { 'min': 0, 'max': 5 }, 'Number of breaks') # Obtain the first change in that time period. dates = change.arrayMask(mask).arrayPad([1]) firstChange = dates \ .arraySlice(0, 0, 1) \ .arrayFlatten([ ['firstChange'] ]) \ .selfMask() timeVisParams = { 'palette': palettes.colorbrewer.YlOrRd[9], 'min': start, 'max': end } Map.addLayer(firstChange, timeVisParams, 'First change') # Obtain the last change in that time period. lastChange = dates \ .arraySlice(0, -1) \ .arrayFlatten([ ['lastChange'] ]) \ .selfMask() Map.addLayer(lastChange, timeVisParams, 'Last change') # Get masked magnitudes. magnitudes = ccdResults \ .select('SWIR1_magnitude') \ .arrayMask(mask) \ .arrayPad([1]) # Get index of max abs magnitude of change. maxIndex = magnitudes \ .abs() \ .arrayArgmax() \ .arrayFlatten([ ['index'] ]) # Select max magnitude and its timing selectedMag = magnitudes.arrayGet(maxIndex) selectedTbreak = dates.arrayGet(maxIndex).selfMask() magVisParams = { 'palette': palettes.matplotlib.viridis[7], 'min': -0.15, 'max': 0.15 } Map.addLayer(selectedMag, magVisParams, 'Max mag') Map.addLayer(selectedTbreak, timeVisParams, 'Time of max mag') # ----------------------------------------------------------------------- # CHECKPOINT # -----------------------------------------------------------------------

Display the interactive map¶

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Map

Map