ee.Geometry.buffer

  • buffer() returns a modified Geometry that is expanded or contracted by a specified distance.

  • Positive distances expand the geometry outwards, while negative distances contract it inwards.

  • The buffering can be performed using meters or a projected coordinate system by specifying the proj parameter.

  • An optional maxError parameter controls the accuracy of the buffer approximation.

 Returns the input buffered by a given distance. If the distance is positive, the geometry is expanded, and if the distance is negative, the geometry is contracted.

UsageReturns
Geometry.buffer(distance, maxError, proj)Geometry
ArgumentTypeDetails
this: geometryGeometryThe geometry being buffered.
distanceFloatThe distance of the buffering, which may be negative. If no projection is specified, the unit is meters. Otherwise the unit is in the coordinate system of the projection.
maxErrorErrorMargin, default: nullThe maximum amount of error tolerated when approximating the buffering circle and performing any necessary reprojection. If unspecified, defaults to 1% of the distance.
projProjection, default: nullIf specified, the buffering will be performed in this projection and the distance will be interpreted as units of the coordinate system of this projection. Otherwise the distance is interpereted as meters and the buffering is performed in a spherical coordinate system.

Examples

Code Editor (JavaScript)

// Define a Geometry object.
var geometry = ee.Geometry({
  'type': 'Polygon',
  'coordinates':
    [[[-122.081, 37.417],
      [-122.086, 37.421],
      [-122.084, 37.418],
      [-122.089, 37.416]]]
});

// Apply the buffer method to the Geometry object.
var geometryBuffer = geometry.buffer({'distance': 100});

// Print the result to the console.
print('geometry.buffer(...) =', geometryBuffer);

// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(geometry,
             {'color': 'black'},
             'Geometry [black]: geometry');
Map.addLayer(geometryBuffer,
             {'color': 'red'},
             'Result [red]: geometry.buffer');

Python setup

See the Python Environment page for information on the Python API and using geemap for interactive development.

import ee
import geemap.core as geemap

Colab (Python)

# Define a Geometry object.
geometry = ee.Geometry({
    'type': 'Polygon',
    'coordinates': [[
        [-122.081, 37.417],
        [-122.086, 37.421],
        [-122.084, 37.418],
        [-122.089, 37.416],
    ]],
})

# Apply the buffer method to the Geometry object.
geometry_buffer = geometry.buffer(distance=100)

# Print the result.
display('geometry.buffer(...) =', geometry_buffer)

# Display relevant geometries on the map.
m = geemap.Map()
m.set_center(-122.085, 37.422, 15)
m.add_layer(geometry, {'color': 'black'}, 'Geometry [black]: geometry')
m.add_layer(
    geometry_buffer, {'color': 'red'}, 'Result [red]: geometry.buffer'
)
m