00081_lc8_tree_cover

 
 
/*
Tutorial Code by Amirhossein Ahrari
YouTube: https://www.youtube.com/@amirhosseinahrarigee

This code is part of a tutorial series on Earth Engine programming techniques
presented on the Amirhossein Ahrari YouTube channel. You are free to use and modify
this code for academic and non-academic purposes. Don't forget to subscribe to
the Amirhossein Ahrari channel and follow the videos to support the instructor!
*/

var cor = [49.46607928539905,37.23498585398302]

var geometry = ee.Geometry.Point(cor)
 
 
var roi = ee.FeatureCollection("FAO/GAUL_SIMPLIFIED_500m/2015/level1")
.filterBounds(geometry)

Map.centerObject(roi)
Map.addLayer(roi)

var mod = ee.ImageCollection("MODIS/006/MOD44B")
.select('Percent_Tree_Cover')
.filterDate('2020','2021').first()

Map.addLayer(mod.clip(roi),[],'mod_tree_cover',false)

var lc8 = ee.ImageCollection("LANDSAT/LC08/C02/T1_L2")
.select('SR_B.*')
.filterDate('2020', '2021')
.filterBounds(roi)
.filter(ee.Filter.lt('CLOUD_COVER_LAND',10))
.median()

var lc8_sr = lc8.multiply(0.0000275).add(-0.2)

var lc8_ndvi = lc8_sr.normalizedDifference(['SR_B5','SR_B4']).rename('ndvi')

Map.addLayer(lc8_ndvi.clip(roi),[],'ndvi',false)

var training_data = lc8_ndvi.addBands(mod)

var linear_fit = training_data.reduceRegion({
  reducer: ee.Reducer.linearFit(), geometry: roi, scale: 100
  })

print(linear_fit)

var scale = ee.Number(linear_fit.values().get(1))
var offset = ee.Number(linear_fit.values().get(0))

print('scale', scale)
print('offset', offset)

var lc8_tree = lc8_ndvi.multiply(scale).add(offset).round().rename('lc8_tree_cover')

var thr = lc8_tree.lt(0).not()

Map.addLayer(thr.clip(roi),[],'thr',false)

var lc8_tree_cover = lc8_tree.updateMask(thr)

Map.addLayer(lc8_tree_cover.clip(roi),[],'lc8_tree_cover',false)


var dif = mod.subtract(lc8_tree_cover)
var dif_pow = dif.pow(2)
var dif_mean = ee.Number(dif_pow.reduceRegion({
  reducer: ee.Reducer.mean(), scale: 100, geometry: roi
  }).values().get(0)).sqrt()
  
print(dif_mean)

Export.image.toDrive({
  image: lc8_tree_cover.clip(roi), 
  description: 'lc8_tree', 
  scale: 30, 
  region: roi, 
  maxPixels: 1e13, 
  folder: 'test', 
  crs: 'EPSG:4326'
  })