在 GEE 中将栅格属性导出到表

Question

我有一个 Google Earth Engine 函数，它在一个特征（函数的几何形状）的边界内聚合

plantation

（ee.Image；函数的输入）的面积，并将其导出到一个 Table，列为 Hansen

lossyear

.

但是，我的数据种植园也有从 1 到 190 的多个子类。我如何修改下面的代码，以便它单独提取每个类的区域并通过添加子类将其导出到同一个Table专栏？

检查 GEE 快照链接：https://code.earthengine.google.com/8fa5d01312ab95d284954ed3eb67ce07

//###########################################################
// For plantation attribution
//###########################################################
function calculateForestLoss_var(input, geometry, savefilename) {
  // Adding evaluated/processed 'area' bands to the Hansen dataset and calculating area
  var variable = area_HansenLoss.updateMask(input.gt(0));
  var Hansen_data_area = Hansen_data.addBands(variable);

  // Calculate the sum of forest loss pixels for each feature in the geometry
  var area_geometrysum = variable.reduceRegions({
    collection: geometry,
    reducer: ee.Reducer.sum(),
    scale: Hansen_scale,
  });

  // Define the list of years to iterate over
  var startYear = 2001;
  var endYear = new Date().toISOString().slice(0,4)-2;
  var years = ee.List.sequence(startYear - 2000, endYear - 2000);

  // Function to add the forest loss data as properties to a feature
  var addVar = function(feature) {
    // Function to iterate over the sequence of years
    var addVarYear = function(year, feat) {
      // Cast var
      year = ee.Number(year).toInt();
      feat = ee.Feature(feat);

      // Actual year to write as property
      var actual_year = ee.Number(2000).add(year);

      // Filter the data by year
      var filtered = Hansen_data_area.select("lossyear").eq(year);

      // Apply the filter to the data
      filtered = Hansen_data_area.updateMask(filtered);

      // Reduce the forest loss data over the feature
      var reduc = filtered.reduceRegion({
        geometry: feature.geometry(),
        reducer: ee.Reducer.sum(),
        scale: Hansen_scale,
        maxPixels: 1e13
      });

      // Get the forest loss value
      var loss = ee.Number(reduc.get("arealoss"));

      // Set the name of the property for the current year
      var nameloss = ee.String("loss_").cat(actual_year);

      // Condition to handle cases where there is no forest loss data available
      var cond = loss.gt(0);

      // Set the property for the current year
      return ee.Algorithms.If(cond, 
                              feat.set(nameloss, loss),
                              feat);
    };

    // Iterate over the sequence of years and add the properties to the feature
    var newfeat = ee.Feature(years.iterate(addVarYear, feature));

    // Return the feature with the new properties
    return newfeat;
  };

  // Map the addVar function over the FeatureCollection
  var areas = area_geometrysum.map(addVar);
  print('FOREST LOSS TO '+savefilename, areas);

  // Generate the list of properties to export based on the start and end years
  var propertiesToExport = ['ADM0_CODE', 'ADM1_CODE', 'ADM2_CODE'];
  for (var i = startYear; i <= endYear; i++) {
    propertiesToExport.push('loss_' + i);
  }
  // Export the results to Google Drive
  Export.table.toDrive({
    collection: areas,
    description: 'Forest_loss_to_'+ savefilename +'_' + startID + '-' + endID + '_' + new Date().toISOString().slice(0,10),
    folder: 'Chalmers_Postdoc/LUC',
    fileFormat: 'CSV',
    selectors: propertiesToExport
  });
}

calculateForestLoss_var(FL_att_to_old_plantations, geometry, 'OLD-PLANTATION')