梅江区建设局网站,东莞网站建设制作,网站建设数据库实训体会,专业网站设计制作优化排名GEE开发之降雨CHIRPS数据获取和分析1.数据介绍2.初识CHIRPS2.1 代码一2.2 代码二3.逐日数据分析和获取4.逐月数据分析和获取4.1 代码一4.2 代码二(简洁)5.逐年数据分析和获取5.1 代码一5.2 代码二(简洁)前言#xff1a;主要获取和分析UCSB-CHG/CHIRPS/DAILY的日数据、月数据和…
GEE开发之降雨CHIRPS数据获取和分析1.数据介绍2.初识CHIRPS2.1 代码一2.2 代码二3.逐日数据分析和获取4.逐月数据分析和获取4.1 代码一4.2 代码二(简洁)5.逐年数据分析和获取5.1 代码一5.2 代码二(简洁)前言主要获取和分析UCSB-CHG/CHIRPS/DAILY的日数据、月数据和年数据。 1.数据介绍
数据集 CHIRPS Daily: Climate Hazards Group InfraRed Precipitation With Station Data (Version 2.0 Final)数据说明 Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) 是一个记录了1981年到当前全球降雨量的数据集。CHIRPS将0.05°分辨率的卫星图像与in-situ站点数据结合创建网格化的降雨时间序列用于趋势分析和季节性干旱监测。
2.初识CHIRPS
2.1 代码一
var geometry ee.FeatureCollection(users/www1573979951/luyixian);
var dataset ee.ImageCollection(UCSB-CHG/CHIRPS/DAILY)
.filterDate(2020-01-01, 2020-12-31)
.filterBounds(geometry)
.select(precipitation);
print(dataset)2.2 代码二
var geometry ee.FeatureCollection(users/www1573979951/luyixian);
Map.centerObject(geometry,7);
var dataset ee.ImageCollection(UCSB-CHG/CHIRPS/DAILY)
.filterDate(2020-01-01, 2020-12-31)
.filterBounds(geometry)
.select(precipitation);
var precipitationVis {min: 1.0,max: 17.0,palette: [001137, 0aab1e, e7eb05, ff4a2d, e90000],
};
Map.addLayer(dataset.mean().clip(geometry), precipitationVis, pre);3.逐日数据分析和获取
var geometry ee.FeatureCollection(users/www1573979951/luyixian);
Map.centerObject(geometry,7);
var dataset ee.ImageCollection(UCSB-CHG/CHIRPS/DAILY)
.filterDate(2020-05-01, 2020-05-31)
.filterBounds(geometry)
.select(precipitation);
print(ui.Chart.image.series(dataset, geometry, ee.Reducer.mean(), 1000));
function exportImageCollection(imgCol) {var indexList imgCol.reduceColumns(ee.Reducer.toList(), [system:index]).get(list);indexList.evaluate(function(indexs) {for (var i0; iindexs.length; i) {var image imgCol.filter(ee.Filter.eq(system:index, indexs[i])).first();image image.clip(geometry);//tif数据下载Export.image.toDrive({image: image,description: pre_indexs[i],fileNamePrefix: pre_indexs[i],folder: pre,region: geometry,scale: 1000,crs: EPSG:4326,maxPixels: 1e13});}});
}
exportImageCollection(dataset); 4.逐月数据分析和获取
4.1 代码一
var geometry ee.FeatureCollection(users/www1573979951/luyixian);
var dataset ee.ImageCollection(UCSB-CHG/CHIRPS/DAILY).filterBounds(geometry).select(precipitation);
//时间范围
var years ee.List.sequence(2020, 2020);
var months ee.List.sequence(1, 12);//将逐日数据生成月平均数据
var monthlysum ee.ImageCollection.fromImages(years.map(function (y) {return months.map(function(m) {return dataset.filter(ee.Filter.calendarRange(y,y, year)).filter(ee.Filter.calendarRange(m, m, month)).sum().set(year, y).set(month, m).set(system:time_start, ee.Date.fromYMD(y, m, 1));});}).flatten());print(monthlysum);
print(ui.Chart.image.series(monthlysum, geometry, ee.Reducer.mean(), 1000));function exportImageCollection(imgCol) {var indexList imgCol.reduceColumns(ee.Reducer.toList(), [system:index]).get(list);indexList.evaluate(function(indexs) {for (var i0; iindexs.length; i) {var image imgCol.filter(ee.Filter.eq(system:index, indexs[i])).first();image image.clip(geometry);//tif数据下载Export.image.toDrive({image: image,description: pre_2020_indexs[i],fileNamePrefix: pre_2020_indexs[i],folder: pre,region: geometry,scale: 1000,crs: EPSG:4326,maxPixels: 1e13});}});
}
exportImageCollection(monthlysum); 4.2 代码二(简洁)
var geometry ee.FeatureCollection(users/www1573979951/luyixian);
Map.centerObject(geometry,6);
var dataset ee.ImageCollection(UCSB-CHG/CHIRPS/DAILY);
for(var i2018;i2020;i){for(var j1;j12;j){var data_collection null;switch(j){case 1:case 3:case 5:case 7:case 8:case 10:case 12:data_collection dataset.filterDate(i-j-01,i-j-31).select(precipitation);break;case 4:case 6:case 9:case 11:data_collection dataset.filterDate(i-j-01,i-j-30).select(precipitation);break;case 2:data_collection dataset.filterDate(i-j-01,i-j-28).select(precipitation);break;}var YR_collection data_collection.sum().clip(geometry);Export.image.toDrive({image: YR_collection,description: i-j,fileNamePrefix: i-j,scale: 1000,region: geometry,maxPixels: 1e13,folder: pre})}
} 5.逐年数据分析和获取
5.1 代码一
var geometry ee.FeatureCollection(users/www1573979951/luyixian);
// 选择数据集并进行波段比例换算
var collection ee.ImageCollection(UCSB-CHG/CHIRPS/DAILY).filterDate(2000-01-01, 2020-12-31).select(precipitation);//进行年平均值的计算
var years ee.List.sequence(2000, 2020);
var collectYear ee.ImageCollection(years.map(function(y) {var start ee.Date.fromYMD(y, 1, 1);var end start.advance(12, month);return collection.filterDate(start, end).reduce(ee.Reducer.sum()).float().set(system:time_start,y).set(year,y);
}));
print(collectYear);
//年均值的时间序列展示
var Yearly_chart ui.Chart.image.series({imageCollection: collectYear.select(precipitation_sum),region: geometry,reducer: ee.Reducer.mean(),scale: 500,xProperty: year,}).setOptions({interpolateNulls: true,lineWidth: 2,title: pre Yearly Seires,vAxis: {title: pre},hAxis: {title: Date},});
print(Yearly_chart);function exportImageCollection(imgCol) {var indexList imgCol.reduceColumns(ee.Reducer.toList(), [system:index]).get(list);indexList.evaluate(function(indexs) {for (var i0; iindexs.length; i) {var image imgCol.filter(ee.Filter.eq(system:index, indexs[i])).first();image image.clip(geometry);//tif数据下载Export.image.toDrive({image: image,description: pre_indexs[i],fileNamePrefix: pre_indexs[i],folder: pre,region: geometry,scale: 1000,crs: EPSG:4326,maxPixels: 1e13});}});
}
exportImageCollection(collectYear);5.2 代码二(简洁)
var geometry ee.FeatureCollection(users/www1573979951/luyixian);
Map.centerObject(geometry,6);
var dataset ee.ImageCollection(UCSB-CHG/CHIRPS/DAILY);for(var i2018;i2020;i){var data_collection dataset.filterDate(i-01-01,i-12-31).select(precipitation);print(data_collection)var YR_collection data_collection.sum().clip(geometry);Export.image.toDrive({image: YR_collection,description: i,fileNamePrefix: i,scale: 1000,region: geometry,maxPixels: 1e13,folder: pre});
}
