ee.Geometry.dissolve

  • dissolve() returns a Geometry object representing the union of the input geometry's components.

  • It simplifies MultiGeometries by merging overlapping or adjacent parts, while leaving single geometries unchanged.

  • Optional parameters maxError and proj control the reprojection tolerance and target projection for the union operation, respectively.

  • Useful for dissolving boundaries between features within a MultiGeometry or creating a single, unified geometry from multiple overlapping geometries.

 Returns the union of the geometry. This leaves single geometries untouched, and unions multi geometries.

UsageReturns
Geometry.dissolve(maxError, proj)Geometry
ArgumentTypeDetails
this: geometryGeometryThe geometry to union.
maxErrorErrorMargin, default: nullThe maximum amount of error tolerated when performing any necessary reprojection.
projProjection, default: nullIf specified, the union will be performed in this projection. Otherwise it will be 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 dissolve method to the Geometry object.
var geometryDissolve = geometry.dissolve({'maxError': 1});

// Print the result to the console.
print('geometry.dissolve(...) =', geometryDissolve);

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

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 dissolve method to the Geometry object.
geometry_dissolve = geometry.dissolve(maxError=1)

# Print the result.
display('geometry.dissolve(...) =', geometry_dissolve)

# 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_dissolve, {'color': 'red'}, 'Result [red]: geometry.dissolve'
)
m