// GEE 下载 ESRI 10 米土地覆盖：类别频数、面积表与可视化截图完整流程// 数据集：projects/sat-io/open-datasets/landcover/ESRI_Global-LULC_10m_TS// 公开使用时请保留 Impact Observatory、Esri、Microsoft、产品年份与 CC BY 4.0。var year = 2024;var fallbackRoi = ee.Geometry.Rectangle([116.24, 39.76, 116.58, 40.02], null, false);// 如果已经在 Imports 中导入自己的研究区并命名为 roi，可把下一行改为：// var region = roi;var region = fallbackRoi;var start = ee.Date.fromYMD(year, 1, 1);var end = start.advance(1, 'year');var collection = ee.ImageCollection(  'projects/sat-io/open-datasets/landcover/ESRI_Global-LULC_10m_TS');var documentedYears = ee.List.sequence(2017, 2024);var selected = collection  .filterBounds(region)  .filterDate(start, end);var lulc = selected  .mosaic()  .select([0], ['lulc'])  .clip(region)  .toUint8();var rawCodes = [1, 2, 4, 5, 7, 8, 9, 10, 11];var displayCodes = [1, 2, 3, 4, 5, 6, 7, 8, 9];var classNames = [  'Water', 'Trees', 'Flooded vegetation', 'Crops', 'Built area',  'Bare ground', 'Snow / ice', 'Clouds', 'Rangeland'];var palette = [  '1A5BAB', '358221', '87D19E', 'FFDB5C', 'ED022A',  'EDE9E4', 'F2FAFF', 'C8C8C8', 'C6AD8D'];var display = lulc.remap(rawCodes, displayCodes).rename('display_class');var classInfo = ee.List.sequence(0, rawCodes.length - 1).map(function(i) {  i = ee.Number(i);  return ee.Dictionary({    class_value: ee.List(rawCodes).get(i),    display_value: ee.List(displayCodes).get(i),    class_name: ee.List(classNames).get(i),    color: ee.List(palette).get(i)  });});var histogram = ee.Dictionary(lulc.reduceRegion({  reducer: ee.Reducer.frequencyHistogram(),  geometry: region,  scale: 10,  maxPixels: 1e13,  tileScale: 4}).get('lulc'));var groupedArea = ee.Image.pixelArea()  .divide(1e6)  .rename('area_km2')  .addBands(lulc)  .reduceRegion({    reducer: ee.Reducer.sum().group({      groupField: 1,      groupName: 'class_value'    }),    geometry: region,    scale: 10,    maxPixels: 1e13,    tileScale: 4  });functiongroupsToAreaDict(groups) {  groups = ee.List(groups);  return ee.Dictionary(groups.iterate(function(item, acc) {    item = ee.Dictionary(item);    return ee.Dictionary(acc).set(ee.Number(item.get('class_value')).format(), item.get('sum'));  }, ee.Dictionary({})));}var areaDict = groupsToAreaDict(groupedArea.get('groups'));var summaryTable = ee.FeatureCollection(classInfo.map(function(item) {  item = ee.Dictionary(item);  var key = ee.Number(item.get('class_value')).format();  return ee.Feature(null, {    class_value: item.get('class_value'),    class_name: item.get('class_name'),    pixel_count: ee.Number(histogram.get(key, 0)),    area_km2: ee.Number(areaDict.get(key, 0))  });}));var totalArea = ee.Number(summaryTable.aggregate_sum('area_km2'));summaryTable = summaryTable.map(function(feature) {  return feature.set('area_percent', ee.Number(feature.get('area_km2')).divide(totalArea).multiply(100));});Map.setOptions('ROADMAP');Map.centerObject(region, 11);Map.addLayer(display, {min: 1, max: 9, palette: palette}, 'ESRI LULC ' + year, true, 0.92);var boundary = ee.Image().byte().paint({  featureCollection: ee.FeatureCollection([ee.Feature(region)]),  color: 1,  width: 3});Map.addLayer(boundary, {palette: ['ffffff']}, '研究区边界');var legend = ui.Panel({style: {position: 'bottom-left', padding: '8px 12px'}});legend.add(ui.Label({value: 'ESRI 10 m LULC ' + year, style: {fontWeight: 'bold'}}));for(var i = 0; i < classNames.length; i++) {  legend.add(ui.Panel({    widgets: [      ui.Label({style: {backgroundColor: '#' + palette[i], padding: '8px', margin: '0 6px 4px 0'}}),      ui.Label({value: rawCodes[i] + '  ' + classNames[i], style: {margin: '0 0 4px 0'}})    ],    layout: ui.Panel.Layout.Flow('horizontal')  }));}Map.add(legend);print('数据来源', 'ESRI Global LULC 10m Time Series');print('数据集路径', 'projects/sat-io/open-datasets/landcover/ESRI_Global-LULC_10m_TS');print('本文脚本固定年份', year);print('常用年度范围提示', documentedYears);print(year + ' 年与研究区相交的影像分块数', selected.size());print('类型说明', classInfo);print('类别频数', histogram);print('类别面积概况_km2', summaryTable);print('输出投影', lulc.projection());print('导出说明', 'Tasks 面板中会生成 GeoTIFF 导出任务；导出保留 1、2、4、5、7、8、9、10、11 原始类别值。');summaryTable.size().evaluate(function(rowCount) {  selected.size().evaluate(function(tileCount) {    totalArea.evaluate(function(areaValue) {      print('WC_GEE002_DONE', {        year: year,        row_count: rowCount,        intersecting_tiles: tileCount,        total_area_km2: areaValue,        server_evaluation_finished: true      });    });  });});Export.image.toDrive({  image: lulc.unmask(0),  description: 'WC_GEE002_ESRI_LULC_' + year,  folder: 'wenchuan_gee_exports',  fileNamePrefix: 'esri_lulc_' + year + '_roi_10m',  region: region,  scale: 10,  maxPixels: 1e13,  fileFormat: 'GeoTIFF',  formatOptions: {    noData: 0,    cloudOptimized: true  }});Export.table.toDrive({  collection: summaryTable,  description: 'WC_GEE002_ESRI_LULC_' + year + '_area_table',  folder: 'wenchuan_gee_exports',  fileNamePrefix: 'esri_lulc_' + year + '_area_table',  fileFormat: 'CSV'});