refactor(Weather_download): 重构天气数据下载脚本并添加导出函数.

GEE_Scripts/Weather_download.js

@@ -10,14 +10,15 @@
  */
 
 // 加载研究区域和影像
-var region_name = "应城市";
+// var region_name = "应城市";
-var region_name_en = "Yingcheng";
+// var region_name_en = "Yingcheng";
-var region = Yingcheng;
+// var region = Yingcheng;
-var crs = "EPSG:4526";
+// var target_crs = "EPSG:4526";
-// var region_name = "保康县";
+var region_name = "保康县";
-// var region_name_en = "Baokang";
+var region_name_en = "Baokang";
-// var region = Baokang;
+var region = Baokang;
-// var crs = "EPSG:4525";
+var target_crs = "EPSG:4525";
+var target_res = 30;
 var start_year = 2021;
 var end_year = 2025;
 var start_date = start_year + "-01-01";
@@ -46,7 +47,7 @@ function kelvinToCelsius(image) {
 // 加载 ERA5-Land 数据
 var ERA5dataset = ee.ImageCollection("ECMWF/ERA5_LAND/MONTHLY_AGGR")
   .filter(common_filter)
-  .select(ERA5Bands, commonBands)
+  .select(ERA5Bands, commonBands);
 print(start_date + " - " + end_date + " ERA5-Land dataset", ERA5dataset);
 var ERA5Tempdataset = ERA5dataset.select("temperature").map(kelvinToCelsius);
 var ERA5Raindataset = ERA5dataset.select("total_precipitation_sum");
@@ -72,24 +73,24 @@ if (start_year == end_year) {
 } else {
   var year_str = start_year + "-" + end_year;
 }
-print(year_str + " Annual Mean ERA5-Land temperature dataset", yearlyTemp);
+print(year_str + " Annual Mean ERA5-Land Temperature dataset", yearlyTemp);
-print(year_str + " Annual Mean ERA5-Land rainfall dataset", yearlyRain);
+print(year_str + " Annual Mean ERA5-Land Precipitation dataset", yearlyRain);
 
 // 合成处理后会丢失投影信息, 需要重新设置投影
 var proj = ERA5dataset.first().select(1).projection();
 var annual_mean_temperature = ee.Image(yearlyTemp.mean()).setDefaultProjection(proj);
-print(year_str + " Annual Mean ERA5-Land temperature Histogram", ui.Chart.image.histogram(annual_mean_temperature, region, 10000, 258));
+print(year_str + " Annual Mean ERA5-Land Temperature Histogram", ui.Chart.image.histogram(annual_mean_temperature, region, 10000, 258));
 
-var annual_mean_rainfall = ee.Image(yearlyRain.mean()).setDefaultProjection(proj);
+var annual_mean_precipitation = ee.Image(yearlyRain.mean()).setDefaultProjection(proj);
-print(year_str + " Annual Mean ERA5-Land rainfall Histogram", ui.Chart.image.histogram(annual_mean_rainfall, region, 10000, 258));
+print(year_str + " Annual Mean ERA5-Land Precipitation Histogram", ui.Chart.image.histogram(annual_mean_precipitation, region, 10000, 258));
 
 var annual_mean_temp_1km = annual_mean_temperature.clip(bounds).resample("bicubic").reproject({
-  crs: proj,
+  crs: "EPSG:4526",
-  scale: 1000,
+  scale: 30,
 });
-var annual_mean_rainfall_1km = annual_mean_rainfall.clip(bounds).resample("bicubic").reproject({
+var annual_mean_precipitation_1km = annual_mean_precipitation.clip(bounds).resample("bicubic").reproject({
-  crs: proj,
+  crs: "EPSG:4526",
-  scale: 1000,
+  scale: 30,
 });
 
 var temperature_vis = {
@@ -119,23 +120,25 @@ var styling = {
 };
 
 Map.centerObject(region, 7);
-Map.addLayer(annual_mean_temperature, temperature_vis, year_str + " ERA5-Land Annual Mean temperature 0.1 degree");
+Map.addLayer(annual_mean_temperature, temperature_vis, year_str + " Annual Mean Temperature 0.1 degree");
-Map.addLayer(annual_mean_rainfall, precipitation_vis, year_str + " ERA5-Land Annual Mean precipitation 0.1 degree");
+Map.addLayer(annual_mean_precipitation, precipitation_vis, year_str + " Annual Mean Precipitation 0.1 degree");
-Map.addLayer(annual_mean_temp_1km, temperature_vis, year_str + " ERA5-Land Annual Mean temperature 1km");
+Map.addLayer(annual_mean_temp_1km, temperature_vis, year_str + " Annual Mean Temperature " + target_res + "m");
-Map.addLayer(annual_mean_rainfall_1km, precipitation_vis, year_str + " ERA5-Land Annual Mean precipitation 1km");
+Map.addLayer(annual_mean_precipitation_1km, precipitation_vis, year_str + " Annual Mean Precipitation " + target_res + "m");
 Map.addLayer(region.style(styling), {}, region_name);
 
 // 导出合并后的影像
 // 明确设置数据类型为Float32, 否则默认类型为Float64, 会占用更多内存
 // 并对缺失值进行填充, 否则默认为nan不便于后续本地处理
-var processed_temp_img = annual_mean_temperature.toFloat().unmask(-9999.0);
+function exportCOG(image, description, folder, region, scale, crs) {
-print("Start exporting " + year_str + "Yearly Mean ERA5-Land temperature image (" + crs + ")", processed_temp_img);
+  image = image.toFloat().unmask(-9999.0);
-Export.image.toDrive({
+  // 默认为 EPSG:4526 投影
-  image: processed_temp_img,
+  crs = crs || "EPSG:4526";
-  description: region_name_en + "_ERA5_Temperature_" + year_str + "_1km",
+  Export.image.toDrive({
-  folder: "Weather",
+    image: image,
+    description: description,
+    folder: folder,
     region: region, // 添加后会自动裁剪
-  scale: 1000,
+    scale: scale,
     crs: crs,
     maxPixels: 1e13, // GEE 最多支持 1e8 像素, 当超过时会自动分块
     fileFormat: "GeoTIFF",
@@ -144,20 +147,24 @@ Export.image.toDrive({
       cloudOptimized: true,
       noData: -9999.0,
     },
-});
+  });
+}
 
-var processed_rain_img = annual_mean_rainfall.toFloat().unmask(-9999.0);
+print("Start exporting " + year_str + " Yearly Mean ERA5-Land Temperature (" + target_crs + " " + target_res + "m)", annual_mean_temperature);
-Export.image.toDrive({
+exportCOG(
-  image: processed_rain_img,
+  annual_mean_temperature,
-  description: region_name_en + "_ERA5_Precipitation_" + year_str + "_1km",
+  region_name_en + "_ERA5_Temperature_" + year_str + "_" + target_res + "m",
-  folder: "Weather",
+  "Temperature",
-  region: region,
+  region,
-  scale: 1000,
+  target_res,
-  crs: crs,
+  target_crs
-  maxPixels: 1e13,
+);
-  fileFormat: "GeoTIFF",
+print("Start exporting " + year_str + " Yearly Mean ERA5-Land Precipitation (" + target_crs + " " + target_res + "m)", annual_mean_precipitation);
-  formatOptions: {
+exportCOG(
-    cloudOptimized: true,
+  annual_mean_precipitation,
-    noData: -9999.0,
+  region_name_en + "_ERA5_Precipitation_" + year_str + "_" + target_res + "m",
-  },
+  "Precipitation",
-});
+  region,
+  target_res,
+  target_crs
+);