这里我们利用凉山州作为火灾边界,同样可以切换我们所需要的区域,可以切换省级代码来进行,需要手动修改。这里我们用到的swith 和case的案例条件判断分析,
- switch(n)
- {
- case 1:
- 执行代码块 1
- break;
- case 2:
- 执行代码块 2
- break;
- default:
- 与 case 1 和 case 2 不同时执行的代码
- }
显示今天的星期名称。请注意 Sunday=0, Monday=1, Tuesday=2, 等等:
- var d=new Date().getDay();
- switch (d)
- {
- case 0:x="今天是星期日";
- break;
- case 1:x="今天是星期一";
- break;
- case 2:x="今天是星期二";
- break;
- case 3:x="今天是星期三";
- break;
- case 4:x="今天是星期四";
- break;
- case 5:x="今天是星期五";
- break;
- case 6:x="今天是星期六";
- break;
- }
'运行
这里面所需的函数:
ui.DateSelect(type,placeholder,value,onChange,disabled,style)
时间选择。
方法参数:
- ui(ui)
调用者:ui对象。
- type(String)
日期选择类型,可选值为date|daterange|year|month|datetime|datetimerange。
- placeholder(String)
占位符内容。
- value(String|List)
选择具体的日期,格式为:yyyy-MM-dd|yyyy-MM-dd HH:mm:ss
- onChange(Function)
更新选择日期触发事件。
- disabled(Boolean)
是否禁用日期组件。
- style(Object)
组件样式。
返回值:ui.DateSelect
这里同样可以导出影像:
image(image,description,assetId,pyramidingPolicy,dimensions,region,scale,crs,crsTransform,maxPixels)
导出影像到个人存储空间。
方法参数:
- export(Export)
Export方法。
- image(Image)
要导出的影像。
- description(String, optional)
导出影像任务的描述。
- assetId(String, optional)
导出影像的存储路径。
- pyramidingPolicy(Object, optional)
金字塔规则。
- dimensions(Int, optional)
维度。
- region(Geometry, optional)
导出影像的范围。
- scale(Float, optional)
缩放比例,目前默认都是1。
- crs(Projection, optional)
投影的基准坐标参考系,暂指定为EPSG:4326或EPSG:3857参考系。
- crsTransform(List, optional)
投影坐标系变换值的列表。
- maxPixels(Long, optional)
要导出的最大像素数。
返回值:null
这个代码的还有提升的结果,如果要发布成为APP,那么就不太容易改变我们的研究区,因为在APP中没有code editor的界面,同样此APP的影像导出结果如果要下载,并没有出现在面板上。另外,对于chart图表的加载并没有加载到MAP上,如果转化为APP的化可能结果都无法显示,所以这个程序只能在code Editor界面中的控制台查看
代码:
- /**
- * @Name : 凉山州火灾高发地异常度分析系统
- * @Author : 西南大学天生一队
- * @Source : 航天宏图第四届 “航天宏图杯”PIE软件二次开发大赛云开发组三等奖获奖作品
- */
-
- //定义程序运行过程需要用到的变量
- var date = ["2018-03-20", "2018-04-20"]; //开始日期和结束日期
- var mapID = null; //当前图层ID
- var maplegend = null; //当前图层图例ID
- var roiID = null; //当前研究范围ID
- var selectTag = "LST"; //选择的计算项目
- var areaCode = "0"; //行政区划代码,默认为0
- var roi = null; //研究区,在程序运行时动态变化
- var default_roi = null; //默认研究区,凉山州
- var sec_year = 2018; //要显示TVDI变化图的年份
- var animationlayerID = []; //如果显示了动态图,则用此数组记录动态图的图层ID
- var currentImg = null; //当前图层所对应的影像,导出时使用
- var exportScale = 500; //导出分辨率
- //获得凉山州矢量
- roi = pie
- .FeatureCollection("NGCC/CHINA_CITY_BOUNDARY")
- .filter(pie.Filter.eq("name", "凉山彝族自治州"))
- .getAt(0)
- .geometry();
- default_roi = roi; //将默认研究区设置为凉山彝族自治州
- //设置渲染样式(默认拉伸渲染,参数为最小值为最大值)
- function setVis(minvalue, maxvalue) {
- var newVis = {
- min: minvalue,
- max: maxvalue,
- palette: [
- "217303",
- "268303",
- "2a9203",
- "2fa203",
- "33b203",
- "37c203",
- "3bd203",
- "40e203",
- "44f203",
- "4bfc09",
- "56fd18",
- "6dfe37",
- "79fe47",
- "8cff05",
- "98ff04",
- "a5fe04",
- "b1fe03",
- "befe02",
- "cbfe02",
- "d7fd02",
- "e3fc02",
- "effb02",
- "faf802",
- "f9eb02",
- "f7dd03",
- "f6cf03",
- "f5c203",
- "f4b503",
- "f3a803",
- "f29b04",
- "f18e04",
- "f08104",
- "ef7404",
- "ee6804",
- "ed5b05",
- "ec4f05",
- "eb4305",
- "e93705",
- "e82b05",
- "e72006",
- "e61406",
- "e50906",
- ],
- };
- return newVis;
- }
-
- //按顺序输入影像集,起始时间、结束时间,要提取的波段名,研究区矢量【仅限单个波段提取】
- function loadCol(nameCol, start, end, bandname, roi) {
- var rCol = pie
- .ImageCollection(nameCol)
- .filterDate(start, end)
- .filterBounds(roi)
- .select(bandname)
- .mean()
- .clip(roi);
- return rCol;
- }
- //更改行政区划后调用的函数
- function getROI(code) {
- var new_roi = null;
- if (code !== 0) {
- var fCol = pie.FeatureCollection("NGCC/CHINA_PROVINCE_BOUNDARY");
- new_roi = fCol
- .filter(pie.Filter.eq("code", parseInt(code)))
- .first()
- .geometry();
- } else {
- new_roi = default_roi;
- }
- return new_roi;
- }
- //下载landsat8影像
- function l8Col_load(start, end) {
- var l8Col = pie
- .ImageCollection("LC08/01/T1")
- .filterDate(start, end)
- .select(["B2", "B3", "B4", "B5", "B6", "BQA"])
- .filterBounds(roi)
- .map(function (image) {
- var qa = image.select("BQA");
- var cloudMask = qa.bitwiseAnd(1 << 3).eq(0);
- return image.updateMask(cloudMask);
- });
- return l8Col;
- }
- //定义Landsat8不同指数计算方式
- var landsat8 = {
- //NDWI: (B03 - B05)/(B03 + B05)
- NDWI: function (image) {
- var b3 = image.select("B3");
- var b5 = image.select("B5");
- var ndvi = b3.subtract(b5).divide(b3.add(b5));
- return ndvi.rename("NDVI");
- },
- //MNDWI: (G - SWIR)/(G + SWIR)
- MNDWI: function (image) {
- var b3 = image.select("B3");
- var b6 = image.select("B6");
- var ndvi = b3.subtract(b6).divide(b3.add(b6));
- return ndvi.rename("MNDWI");
- },
- //NDVI: (B05 - B04)/(B05 + B04)
- NDVI: function (image) {
- var b5 = image.select("B5");
- var b4 = image.select("B4");
- var ndvi = b5.subtract(b4).divide(b5.add(b4));
- return ndvi.rename("NDVI");
- },
- //EVI: 2.5*(B05 - B04) / (B05 + 6*B04 - 7.5*B02 + 1)
- EVI: function (image) {
- var nir = image.select("B5").divide(10000);
- var red = image.select("B4").divide(10000);
- var blue = image.select("B2").divide(10000);
- var evi = nir
- .subtract(red)
- .multiply(2.5)
- .divide(nir.add(red.multiply(6)).subtract(blue.multiply(7.5)).add(1));
- return evi.rename("EVI");
- },
- };
- //点击“确定”按钮后调用的计算函数,用于计算选择的指标
- function calcuate(roi, startDate, endDate, tag) {
- //影像集合
- var l8Col = pie.ImageCollection("LC08/01/T1");
- //通过日期过滤影像集合,并计算
- l8Col = l8Col
- .filterDate(startDate, endDate)
- .select(["B2", "B3", "B4", "B5", "B6", "BQA"])
- .filterBounds(roi)
- .map(function (image) {
- var qa = image.select("BQA");
- var cloudMask = qa.bitwiseAnd(1 << 4).eq(0);
- return image.updateMask(cloudMask);
- });
- var image = null;
- var vis = null;
- switch (tag) {
- case "LST":
- image = loadCol("USGS/MOD11A1/006", date[0], date[1], "LST_Day_1km", roi)
- .multiply(0.02)
- .subtract(273.15);
- vis = setVis(0, 40);
- addLegend("地表温度(°C)", [10, 20, 30, 40]);
- break;
- case "NDVI":
- image = l8Col.map(landsat8.NDVI).mean().clip(roi);
- vis = setVis(-0.2, 0.8);
- addLegend("NDVI Value", ["0", "0.6"]);
- break;
- case "NDWI":
- image = l8Col.map(landsat8.NDWI).mean().clip(roi);
- vis = setVis(-1, 0.3);
- addLegend("NDWI Value", ["-0.8", "0.1"]);
- break;
- case "MNDWI":
- image = l8Col.map(landsat8.MNDWI).mean().clip(roi);
- vis = setVis(-1, 0.3);
- addLegend("MNDWI Value", ["-0.8", "0.1"]);
- break;
- case "EVI":
- image = l8Col.map(landsat8.EVI).mean().clip(roi);
- vis = setVis(-0.2, 0.8);
- addLegend("EVI Value", ["0", "0.6"]);
- break;
- case "TVDI": //调用TVDI数据产品
- image = loadCol("BNU/GLOBAL_1KM_TVDI", date[0], date[1], "B1", roi);
- image = image.divide(10000);
- vis = setVis(0, 1);
- addLegend("TVDI Value(0~1)", ["0.25", "0.75"]);
- break;
- case "火点": //调用MODIS数据产品
- image = loadCol("USGS/MOD14A2/006", date[0], date[1], "FireMask", roi);
- vis = setVis(3, 8);
- addLegend("置信等级", ["<3", 4, 5, 6, 7, 8]);
- break;
- }
- if (mapID !== null) {
- Map.removeLayer(mapID); //如果有图层ID则将其移除,保证只有1个图层显示
- }
- mapID = Map.addLayer(image, vis, tag);
- currentImg = image;
- }
- //添加图例样式的函数,作用在于计算的项目发生改变时动态调整图例,参数:1)titile:string;2)labels:object[]
- function addLegend(title, labels) {
- var data = {
- title: title,
- colors: [
- "#217303",
- "#268303",
- "#2a9203",
- "#2fa203",
- "#33b203",
- "#37c203",
- "#3bd203",
- "#40e203",
- "#44f203",
- "#4bfc09",
- "#56fd18",
- "#6dfe37",
- "#79fe47",
- "#8cff05",
- "#98ff04",
- "#a5fe04",
- "#b1fe03",
- "#befe02",
- "#cbfe02",
- "#d7fd02",
- "#e3fc02",
- "#effb02",
- "#faf802",
- "#f9eb02",
- "#f7dd03",
- "#f6cf03",
- "#f5c203",
- "#f4b503",
- "#f3a803",
- "#f29b04",
- "#f18e04",
- "#f08104",
- "#ef7404",
- "#ee6804",
- "#ed5b05",
- "#ec4f05",
- "#eb4305",
- "#e93705",
- "#e82b05",
- "#e72006",
- "#e61406",
- "#e50906",
- ],
- labels: labels,
- step: 30,
- };
- var style = {
- right: "150px",
- bottom: "10px",
- height: "70px",
- width: "350px",
- };
- if (maplegend !== null) {
- Map.removeUI(maplegend); //如果存在图例则将其移除,保证只有一个图例
- }
- maplegend = ui.Legend(data, style);
- Map.addUI(maplegend);
- }
- //导出当前图层所对应的影像
- function exportCurrentMap(img, description, roi, scale) {
- if (currentImg !== null && animationlayerID.length == 0) {
- Export.image({
- image: img,
- description: description,
- region: roi,
- scale: scale,
- });
- print("导出成功!");
- } else {
- print("当前图层为空或图层不唯一!");
- }
- }
- //根据年份计算每个月的TVDI,并显示折线图。TVDI值越大,土壤湿度越低,反之土壤湿度越高
- function calculateTVDI(start, end) {
- var img = pie
- .ImageCollection("BNU/GLOBAL_1KM_TVDI")
- .filterDate(start, end)
- .select("B1")
- .filterBounds(roi)
- .mean()
- .clip(roi)
- .divide(10000);
- return img;
- }
- function showTVDI(year) {
- var month = [
- "-01",
- "-02",
- "-03",
- "-04",
- "-05",
- "-06",
- "-07",
- "-08",
- "-09",
- "-10",
- "-11",
- "-12",
- ];
- var day = [
- "-31",
- "-28",
- "-31",
- "-30",
- "-31",
- "-30",
- "-31",
- "-31",
- "-30",
- "-31",
- "-30",
- "-31",
- ];
- var data = [];
- for (var i = 0; i < 12; i++) {
- var t1 = calculateTVDI(year + month[i] + "-01", year + month[i] + day[i]);
- var t2 = t1.reduceRegion(pie.Reducer.mean(), roi, 1000);
- data.push(t2);
- }
- var line_a = {
- title: year + "年TVDI变化",
- legend: ["TVDI"],
- xAxisName: "月份",
- yAxisName: "TVDI值",
- chartType: "line",
- yMin: 0,
- yMax: 1,
- smooth: true,
- };
-
- // 显示折线图
- var mark = [
- "01",
- "02",
- "03",
- "04",
- "05",
- "06",
- "07",
- "08",
- "09",
- "10",
- "11",
- "12",
- ];
- ChartImage(data, mark, line_a);
- }
- //显示某年动态图的函数
- function showAnimation(year) {
- var month = [
- "-01",
- "-02",
- "-03",
- "-04",
- "-05",
- "-06",
- "-07",
- "-08",
- "-09",
- "-10",
- "-11",
- "-12",
- ];
- var day = [
- "-31",
- "-28",
- "-31",
- "-30",
- "-31",
- "-30",
- "-31",
- "-31",
- "-30",
- "-31",
- "-30",
- "-31",
- ];
- var data = [];
- if (mapID !== null) {
- Map.removeLayer(mapID);
- }
- if (animationlayerID.length > 0) {
- for (var i = 0; i < animationlayerID.length; i++) {
- Map.removeLayer(animationlayerID[i]);
- }
- animationlayerID = [];
- }
- switch (selectTag) {
- case "TVDI":
- for (var i = 0; i < 12; i++) {
- var img = null;
- var start = year + month[i] + "-01";
- var end = year + month[i] + day[i];
- img = calculateTVDI(start, end);
- var map = Map.addLayer(
- img,
- setVis(0, 1),
- year + month[i] + "TVDI",
- false
- );
- animationlayerID.push(map);
- data.push(year + month[i] + "TVDI");
- }
- addLegend("TVDI Value(0~1)", ["0.25", "0.75"]);
- break;
- case "LST":
- for (var i = 0; i < 12; i++) {
- var img = null;
- var start = year + month[i] + "-01";
- var end = year + month[i] + day[i];
- img = loadCol("USGS/MOD11A1/006", start, end, "LST_Day_1km", roi)
- .multiply(0.02)
- .subtract(273.15);
- var map = Map.addLayer(
- img,
- setVis(0, 40),
- year + month[i] + "LST",
- false
- );
- animationlayerID.push(map);
- data.push(year + month[i] + "LST");
- }
- addLegend("地表温度(°C)", [10, 20, 30, 40]);
- break;
- case "火点":
- for (var i = 0; i < 12; i++) {
- var img = null;
- var start = year + month[i] + "-01";
- var end = year + month[i] + day[i];
- img = loadCol("USGS/MOD14A2/006", start, end, "FireMask", roi);
- var map = Map.addLayer(
- img,
- setVis(3, 8),
- year + month[i] + "火点",
- false
- );
- animationlayerID.push(map);
- data.push(year + month[i] + "火点");
- }
- addLegend("置信等级", ["<3", 4, 5, 6, 7, 8]);
- break;
- case "NDVI":
- for (var i = 0; i < 12; i++) {
- var img = null;
- var start = year + month[i] + "-01";
- var end = year + month[i] + day[i];
- img = l8Col_load(start, end).map(landsat8.NDVI).mean().clip(roi);
- var map = Map.addLayer(
- img,
- setVis(-0.2, 0.8),
- year + month[i] + "NDVI",
- false
- );
- animationlayerID.push(map);
- data.push(year + month[i] + "NDVI");
- }
- addLegend("NDVI Value", ["0", "0.6"]);
- break;
- case "NDWI":
- for (var i = 0; i < 12; i++) {
- var img = null;
- var start = year + month[i] + "-01";
- var end = year + month[i] + day[i];
- img = l8Col_load(start, end).map(landsat8.NDWI).mean().clip(roi);
- var map = Map.addLayer(
- img,
- setVis(-1, 0.3),
- year + month[i] + "NDWI",
- false
- );
- animationlayerID.push(map);
- data.push(year + month[i] + "NDWI");
- }
- addLegend("NDWI Value", ["-0.8", "0.1"]);
- break;
- case "MNDWI":
- for (var i = 0; i < 12; i++) {
- var img = null;
- var start = year + month[i] + "-01";
- var end = year + month[i] + day[i];
- img = l8Col_load(start, end).map(landsat8.MNDWI).mean().clip(roi);
- var map = Map.addLayer(
- img,
- setVis(-1, 0.3),
- year + month[i] + "MNDWI",
- false
- );
- animationlayerID.push(map);
- data.push(year + month[i] + "MNDWI");
- }
- addLegend("MNDWI Value", ["-0.8", "0.1"]);
- break;
- case "EVI":
- for (var i = 0; i < 12; i++) {
- var img = null;
- var start = year + month[i] + "-01";
- var end = year + month[i] + day[i];
- img = l8Col_load(start, end).map(landsat8.EVI).mean().clip(roi);
- var map = Map.addLayer(
- img,
- setVis(-0.2, 0.8),
- year + month[i] + "EVI",
- false
- );
- animationlayerID.push(map);
- data.push(year + month[i] + "EVI");
- }
- addLegend("EVI Value", ["0", "0.6"]);
- break;
- }
- Map.playLayersAnimation(data, 1, -1); //动图间隔时间1秒,无限次循环。
- }
-
- Map.centerObject(roi, 5); //将地图中心转到研究范围
- /* -------------------------以下代码是控件的布局以及事件的绑定等参数设置----------------------------- */
- function funDateSelect(value) {
- date[0] = value[0];
- date[1] = value[1];
- }
- var dateSelect = ui.DateSelect({
- type: "daterange",
- placeholder: "请输入数值",
- value: ["2018-03-20", "2018-04-20"],
- onChange: funDateSelect,
- disabled: false,
- });
- function changeSelect(value) {
- selectTag = value;
- }
- var select1 = ui.Select({
- items: ["LST", "TVDI", "火点", "NDVI", "NDWI", "MNDWI", "EVI"],
- placeholder: "请选择",
- value: selectTag,
- multiple: false,
- onChange: changeSelect,
- });
- var selectIndex = ui.Label("选择项目:");
- var selectPanel = ui.Panel({
- widgets: [selectIndex, select1],
- layout: ui.Layout.flow("horizontal"),
- });
- function inputArea(value) {
- areaCode = value;
- roi = getROI(areaCode);
- }
- var textBox3 = ui.TextBox({
- placeholder: "请输入行政区划编码",
- value: areaCode,
- onChange: inputArea,
- disabled: false,
- });
- var textboxName3 = ui.Label("更改行政区划(省级):");
- var txtPanel1 = ui.Panel({
- widgets: [textboxName3, textBox3],
- layout: ui.Layout.flow("horizontal"),
- });
- var selecDateLabel = ui.Label("选择日期范围:");
- var txtPanel2 = ui.Panel({
- widgets: [selecDateLabel, dateSelect],
- layout: ui.Layout.flow("horizontal"),
- });
- //点击“确定”按钮调用的函数
- function click_BtnOK() {
- print("当前计算项目:", selectTag + "," + date[0] + "~" + date[1]);
- //调用计算函数计算选择的指标添加到地图
- calcuate(roi, date[0], date[1], selectTag);
- if (animationlayerID.length > 0) {
- for (var i = 0; i < animationlayerID.length; i++) {
- Map.removeLayer(animationlayerID[i]);
- }
- animationlayerID = [];
- }
- }
- var btnOK = ui.Button({
- label: "确定",
- type: "success",
- onClick: click_BtnOK,
- style: { left: "50px" },
- });
- function click_btnExport() {
- exportCurrentMap(
- currentImg,
- date[0] + "-" + date[1] + selectTag,
- roi,
- exportScale
- );
- }
- var btnExport = ui.Button({
- label: "导出当前图层",
- type: "success",
- onClick: click_btnExport,
- style: { left: "50px" },
- });
- function changeScale(value) {
- exportScale = value;
- }
- var select2 = ui.Select({
- items: [30, 50, 100, 200, 500, 1000, 2000],
- placeholder: "请选择",
- value: exportScale,
- multiple: false,
- onChange: changeScale,
- });
- var selectPanel2 = ui.Panel({
- widgets: [ui.Label("选择导出分辨率(米):"), select2],
- layout: ui.Layout.flow("horizontal"),
- });
- function click_btnMonthly() {
- showAnimation(sec_year);
- }
- var btnMonthly = ui.Button({
- label: "显示当前指标每月动态图",
- type: "success",
- onClick: click_btnMonthly,
- style: { left: "10px" },
- });
- function click_showBtn() {
- //画出选择的年份TVDI变化图
- showTVDI(sec_year);
- }
- var btnShow = ui.Button({
- label: "显示TVDI变化折线图",
- type: "success",
- onClick: click_showBtn,
- style: { left: "10px" },
- });
- var btnPanel1 = ui.Panel({
- widgets: [btnOK, btnExport],
- layout: ui.Layout.flow("horizontal"),
- });
- function inputYear(value) {
- sec_year = value;
- }
- var txtBoxyear = ui.TextBox({
- placeholder: "请输入年份",
- value: sec_year,
- onChange: inputYear,
- disabled: false,
- });
- var labelyear = ui.Label("输入年份:");
- var txtPanel3 = ui.Panel({
- widgets: [labelyear, txtBoxyear],
- layout: ui.Layout.flow("horizontal"),
- });
- var btnPanel2 = ui.Panel({
- widgets: [btnShow, btnMonthly],
- layout: ui.Layout.flow("horizontal"),
- });
- var panel = ui.Panel({
- widgets: [
- ui.Label("凉山彝族自治州火灾异常监测", { "font-size": "18px" }),
- ui.Label(
- "默认区域为凉山彝族自治州,若想更换区域请输入行政区代码(省级),若输入0则为默认区域",
- { "font-size": "18px" }
- ),
- selectPanel,
- txtPanel1,
- txtPanel2,
- btnPanel1,
- selectPanel2,
- txtPanel3,
- btnPanel2,
- ],
- style: {
- width: "400px",
- height: "500px",
- backgroundColor: "#fff",
- },
- });
- ui.root.add(panel);
- /* 以上是网页上的整体框架布局*/
结果:

