RADD_alerts_GEE

/**** Start of imports. If edited, may not auto-convert in the playground. ****/
var cafi = ee.FeatureCollection("projects/cafi_fao_congo/aoi/aoi_cafi"),
    FNF2015 = ee.Image("projects/cafi_fao_congo/classification/FNF_2015"),
    lsib = ee.FeatureCollection("projects/cafi_fao_congo/aoi/congo_basin_lsib");
/***** End of imports. If edited, may not auto-convert in the playground. *****/

//Accessing RADD forest disturbance alert (Reiche et al.,2021)
//Website: http://radd-alert.wur.nl
//Citation: Reiche et al. (2021): Forest disturbance alerts for the Congo Basin using Sentinel-1, ERL.

//add study area
Map.addLayer(lsib)
//---------------------------
//Access RADD image collection
//---------------------------
var radd = ee.ImageCollection('projects/radar-wur/raddalert/v1');
var geography = 'africa' // 'africa' (africa), 'asia' (asia & pacific)
var area = lsib.filter(ee.Filter.eq('CODE','COG'))
//print('RADD image collection:', radd);
//----------------------------------------
//Forest baseline 

//----------------------------------------
var forest_baseline = FNF2015
Map.addLayer(forest_baseline, {palette:['black'], opacity: 0.3},'Forest baseline')
//-----------------
//Latest RADD alert
//-----------------
var latest_radd_alert =  ee.Image(radd.filterMetadata('layer','contains','alert')
                            .filterMetadata('geography','contains',geography)
                            .sort('system:time_end', false).first());
print('Latest RADD alert '+ geography+':',latest_radd_alert)
//RADD alert: 2 = unconfirmed (low confidence) alert; 3 = confirmed (high confidence) alert
Map.addLayer(latest_radd_alert.select('Alert'), {min:2,max:3,palette:['blue','coral']}, 'RADD alert')
//RADD alert date: YYDOY (Year-Year-Day-Of-Year)
Map.addLayer(latest_radd_alert.select('Date'), {min:19000,max:24000, palette: ['ffffcc','800026']}, 'RADD alert date')
Map.setOptions('Satellite');
if (geography =='africa') {Map.setCenter(16,4,12)}
if (geography =='asia') {Map.setCenter(133.1,-3.2,12)}
var confirmed = latest_radd_alert.select('Alert').eq(3).clip(cafi).updateMask(FNF2015)
//chart annual changes in aoi
var raddyear = latest_radd_alert.select('Date').divide(1000).add(2000).updateMask(confirmed).toInt()
Map.addLayer(raddyear,{}, 'radd year')
print(raddyear,{min:2019, max:2023},'raddyear')
var raddarea = raddyear.multiply(ee.Image.pixelArea().divide(10000))
var raddcalc = raddarea.addBands(raddyear).reduceRegion({
  reducer: ee.Reducer.sum().group({
    groupField: 1
    }),
  geometry: area,
  scale: 100,
  maxPixels: 1e13
});
print(raddcalc)
var raddstatsFormatted = ee.List(raddcalc.get('groups'))
  .map(function(el) {
    var d = ee.Dictionary(el);
    return [ee.Number(d.get('group')).format("%02d"), d.get('sum')];
  });
  
 var raddstatsDictionary = ee.Dictionary(raddstatsFormatted.flatten());
 
 var raddchart = ui.Chart.array.values({
  array: raddstatsDictionary.values(),
  axis: 0,
  xLabels: raddstatsDictionary.keys()
}).setChartType('ColumnChart')
  .setOptions({
    title: 'Yearly Disturbance ',
    hAxis: {title: 'Year', format: '####'},
    vAxis: {title: 'Area (m2)'},
    legend: { position: "none" },
    lineWidth: 1,
    pointSize: 3
  });
  
 print(raddchart)