Annual rainfall

Calculate yearly amount of rainfall in your country

Step 1: import the chirps data

Step 2: Set the date variables

```// set start and end year
var startyear = 2000;
var endyear = 2014;

// make a date object
var startdate = ee.Date.fromYMD(startyear, 1, 1);
var enddate = ee.Date.fromYMD(endyear + 1, 1, 1);

// make a list with years
var years = ee.List.sequence(startyear, endyear);
```

Step 3: Set the geographic location

```// Specify Country names
var country_names = ['Indonesia'];

// Get the country boundaries
var countries = ee.FeatureCollection('ft:1tdSwUL7MVpOauSgRzqVTOwdfy17KDbw-1d9omPw');

// Filter for country
var Indonesia = countries.filter(ee.Filter.inList('Country', country_names));

// Get the geometry
var Indonesia = Indonesia.geometry();
```

Step 4: Calculate the yearly precipitation

```var annualPrecip = ee.ImageCollection.fromImages(
years.map(function (year) {
var annual = chirps
.filter(ee.Filter.calendarRange(year, year, 'year'))
.sum();
return annual
.set('year', year)
.set('system:time_start', ee.Date.fromYMD(year, 1, 1));
}));
```

Step 5: Make a chart of the data

```var title = {
title: 'Annual precipitation',
hAxis: {title: 'Time'},
vAxis: {title: 'Precipitation (mm)'},
};

var chart = ui.Chart.image.seriesByRegion({
imageCollection: annualPrecip,
regions: Indonesia,
reducer: ee.Reducer.mean(),
band: 'precipitation',
scale: 2500,
xProperty: 'system:time_start',
seriesProperty: 'SITE'
}).setOptions(title)
.setChartType('ColumnChart');
```

Step 6: Calculate the mean of the period

```var annualMean = annualPrecip.mean().clip(Indonesia);
```

Step 7: Calculate the mean of the period

```var annualMean = annualPrecip.mean().clip(Indonesia);
```

Step 8: show the map

```var pViz = {
min: 2000,
max: 5500,
palette: '000000, 0000FF, FDFF92, FF2700, FF00E7'
};

Map.centerObject(Indonesia, 5);