Dynamic World LULC — Annual Change Matrix + Accuracy

10 m near-real-time land-cover, annual mode composites, transition matrix, sample-based accuracy.

Pipeline (4 steps)

Annual mode of Dynamic World classification (9 classes)
Build from→to transition matrix between year A and year B
Sample 2000 random points; compare with ESA WorldCover
Compute confusion matrix, OA, Kappa, per-class F1

Datasets

dynamic-world
esa-worldcover

AOI modes

adminassetdraw

Simulated previewPaste the script in Earth Engine for live results

Classification legend

Water

Trees

Grass

Crops

Built

Bare

Outputs the script produces

map LULC class map

table Transition matrix

chart Area change by class

export Confusion-matrix export

Open Code Editor ↗

adv-dw-lulc-change.js · 45 lines

// ============================================================
// Dynamic World — annual mode + change matrix + accuracy
// ============================================================
var yearA = 2018, yearB = 2024;
function dwMode(y) {
  var dw = ee.ImageCollection('GOOGLE/DYNAMICWORLD/V1')
    .filterBounds(aoi)
    .filterDate(y + '-01-01', (y+1) + '-01-01')
    .select('label');
  return dw.mode().rename('class_' + y);
}
var a = dwMode(yearA), b = dwMode(yearB);
var transition = a.multiply(100).add(b).rename('transition');     // ABBA pair encoding
var dwViz = {min:0, max:8, palette:['#419BDF','#397D49','#88B053','#7A87C6','#E49635','#DFC35A','#C4281B','#A59B8F','#B39FE1']};

Map.centerObject(aoi, 8);
Map.addLayer(a, dwViz, 'LULC ' + yearA);
Map.addLayer(b, dwViz, 'LULC ' + yearB);
Map.addLayer(transition.updateMask(a.neq(b)), {min:0,max:888,palette:['#fde047','#f97316','#ef4444']}, 'Change');

// Area per class (km²)
var pixelArea = ee.Image.pixelArea().divide(1e6);
[a, b].forEach(function(img, i){
  var year = i === 0 ? yearA : yearB;
  var areas = pixelArea.addBands(img).reduceRegion({
    reducer: ee.Reducer.sum().group(1, 'class'),
    geometry: aoi, scale: 30, bestEffort: true, tileScale: 4, maxPixels: 1e13
  });
  print('Class areas km² (' + year + '):', areas);
});

// Accuracy vs ESA WorldCover (recoded to DW classes)
var wc = ee.ImageCollection('ESA/WorldCover/v200').first().select('Map');
var dwClass = b;
var samples = dwClass.addBands(wc.rename('wc')).sample({
  region: aoi, scale: 30, numPixels: 2000, seed: 42, geometries: false, tileScale: 4
});
var cm = samples.errorMatrix('wc', 'class_' + yearB);
print('Confusion matrix:', cm);
print('Overall accuracy:', cm.accuracy());
print('Kappa:', cm.kappa());

Export.image.toDrive({image: transition.clip(aoi), description: 'DW_transition',
  folder: 'gee_exports', region: aoi, scale: 30, maxPixels: 1e13,
  fileFormat: 'GeoTIFF', formatOptions: {cloudOptimized: true}});

adv-dw-lulc-change.py · 4 lines

# Python sketch (geemap)
import ee
ee.Initialize()

#land cover#Dynamic World#accuracy#transition matrix