基于GEE的2019-2024年研究区大气污染物浓度月度变化趋势（CO、NO₂、SO₂、O₃、HCHO）

目录

1 完整代码

2 运行结果

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本文使用Copernicus Sentinel-5P卫星的NRTI L3数据集，监测研究区2019-2024年的CO、NO₂、SO₂、O₃和HCHO的月度变化，单位均为mol/m^2。

1 完整代码 var roi = table; var time_start = '2019-01-01'; var time_end = '2024-12-31'; var co = ee.ImageCollection('COPERNICUS/S5P/NRTI/L3_CO') .select('CO_column_number_density') .filterDate(time_start, time_end) .filterBounds(roi); var no2 = ee.ImageCollection('COPERNICUS/S5P/NRTI/L3_NO2') .select('NO2_column_number_density') .filterDate(time_start, time_end) .filterBounds(roi); var so2 = ee.ImageCollection('COPERNICUS/S5P/NRTI/L3_SO2') .select('SO2_column_number_density') .filterDate(time_start, time_end) .filterBounds(roi); var o3 = ee.ImageCollection('COPERNICUS/S5P/NRTI/L3_O3') .select('O3_column_number_density') .filterDate(time_start, time_end) .filterBounds(roi); var hcho = ee.ImageCollection('COPERNICUS/S5P/NRTI/L3_HCHO') .select('tropospheric_HCHO_column_number_density') .filterDate(time_start, time_end) .filterBounds(roi); var months = ee.List.sequence(1, 12); var years = ee.List.sequence(2019, 2024); function monthlyAverage(imgCol, bandName) { var monthlyMeans = years.map(function(year) { return months.map(function(month) { var start = ee.Date.fromYMD(year, month, 1); var end = start.advance(1, 'month'); var monthlyCol = imgCol.filterDate(start, end); var meanImg = monthlyCol.mean().set({ 'year': year, 'month': month, 'system:time_start': start.millis() }); return meanImg; }); }).flatten(); return ee.ImageCollection(monthlyMeans); } var coMonthly = monthlyAverage(co, 'CO_column_number_density'); var no2Monthly = monthlyAverage(no2, 'NO2_column_number_density'); var so2Monthly = monthlyAverage(so2, 'SO2_column_number_density'); var o3Monthly = monthlyAverage(o3, 'O3_column_number_density'); var hchoMonthly = monthlyAverage(hcho, 'tropospheric_HCHO_column_number_density'); function chartTimeSeries(imageCollection, bandName, title, yLabel) { var chart = ui.Chart.image.series({ imageCollection: imageCollection.select(bandName), region: roi, reducer: ee.Reducer.mean(), scale: 10000 }) .setOptions({ title: title, hAxis: { title: 'Time', format: 'YYYY-MM' }, vAxis: { title: yLabel }, lineWidth: 2, pointSize: 3, series: { 0: { color: 'red' } } }); return chart; } var coChart = chartTimeSeries(coMonthly, 'CO_column_number_density', 'CO Monthly Variation (2019-2024)', 'CO Density'); var no2Chart = chartTimeSeries(no2Monthly, 'NO2_column_number_density', 'NO₂ Monthly Variation (2019-2024)', 'NO₂ Density'); var so2Chart = chartTimeSeries(so2Monthly, 'SO2_column_number_density', 'SO₂ Monthly Variation (2019-2024)', 'SO₂ Density'); var o3Chart = chartTimeSeries(o3Monthly, 'O3_column_number_density', 'O₃ Monthly Variation (2019-2024)', 'O₃ Density'); var hchoChart = chartTimeSeries(hchoMonthly, 'tropospheric_HCHO_column_number_density', 'HCHO Monthly Variation (2019-2024)', 'HCHO Density'); print(coChart); print(no2Chart); print(so2Chart); print(o3Chart); print(hchoChart); 2 运行结果 CO Monthly Variation (2019-2024) NO₂ Monthly Variation (2019-2024) SO₂ Monthly Variation (2019-2024) O₃ Monthly Variation (2019-2024) HCHO Monthly Variation (2019-2024)