Google Earth Engine Quiz

How can you filter and display the India boundary in Google Earth Engine from a global boundary dataset?

• Using regions.filter(ee.Filter.eq('country_na', 'India'))

• Using regions.select('India')

• Using regions.clip('India')

• Using regions.map('India')

what does this code snippet do?

Export.table.toDrive({

  collection: lakecoll,

  description: 'Varthur lake',

  folder: 'Lakes',

  fileFormat: 'SHP'

});

• Export a raster image of the lake to Google Drive as a shapefile (SHP).

• Export a feature collection representing the lake to Google Drive as a shapefile (SHP).

• Export a satellite image of the lake to Google Earth as a KML file.

• Export a topographic map of the lake to Google Drive as a CSV file.

What does the following code do in Google Earth Engine?

var bufferValue = 5000;

var buff = aoi.buffer(bufferValue, 1);

Map.addLayer(buff);

• Creates a 5000km buffer around aoi and adds it to the map

• Creates a 5000-meter buffer around aoi and adds it to the map

• Clips the area of interest to a 5000-meter radius

• Creates a boundary within 5000 meters of the AOI and removes it from the map

What does the .union() function do when applied to bufferedPoints in this code?

• Merges multiple point buffers into one dissolved layer

• Creates a buffer around each point

• Filters the points to include only those within the buffer

• Removes overlapping areas between buffered points

What is the purpose of the map() function in Google Earth Engine when applied to a FeatureCollection?

• It filters the FeatureCollection based on specific criteria.

• It applies a function to each feature in the FeatureCollection and returns a new FeatureCollection.

• It merges two FeatureCollections into one.

• It removes features from the FeatureCollection based on a condition.

Which of the following statements about const is true?

• Variables declared with const can be reassigned.

• const is block-scoped.

• Variables declared with const are not block-scoped.

• Variables declared with const can be hoisted like var.

What will be the output of the following code?

const y = 10;

y = 15;

console.log(y);

• 15

• 10

• undefined

• TypeError

Which of the following correctly describes the behavior of variables declared with let?

• They are function-scoped.

• They are globally scoped.

• They are block-scoped and can be reassigned.

• They cannot be reassigned after being initialized.

what is the purpose of the given function?

var ImageColl = L8.map(function(image)

{ var ndvi = image.normalizedDifference(['B5','B4']).rename('NDVI');

 return image.addBands(ndvi); })

• To filter images with a cloud cover greater than 5%

• To calculate and add the NDVI band to each image in the ImageCollection

• To visualize the NDVI time series chart

• To set the title and axis options for the chart

What is the purpose of the reduceRegion function?

• To display the DEM layer on the map

• To calculate a summary statistic for pixel values within the region

• To clip the DEM to the region of interest (aoi)

• To calculate the slope from the DEM