ee.Geometry.Polygon.dissolve

  • The dissolve method returns the union of a geometry, leaving single geometries untouched and uniting multi geometries.

  • The dissolve method takes optional arguments maxError and proj to specify the maximum error tolerated and the projection for the union, respectively.

  • The output of the dissolve method is always a Geometry object.

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

UsageReturns
Polygon.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 Polygon object.
var polygon = ee.Geometry.Polygon(
    [[[-122.092, 37.424],
      [-122.086, 37.418],
      [-122.079, 37.425],
      [-122.085, 37.423]]]);

// Apply the dissolve method to the Polygon object.
var polygonDissolve = polygon.dissolve({'maxError': 1});

// Print the result to the console.
print('polygon.dissolve(...) =', polygonDissolve);

// Display relevant geometries on the map.
Map.setCenter(-122.085, 37.422, 15);
Map.addLayer(polygon,
             {'color': 'black'},
             'Geometry [black]: polygon');
Map.addLayer(polygonDissolve,
             {'color': 'red'},
             'Result [red]: polygon.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 Polygon object.
polygon = ee.Geometry.Polygon([[
    [-122.092, 37.424],
    [-122.086, 37.418],
    [-122.079, 37.425],
    [-122.085, 37.423],
]])

# Apply the dissolve method to the Polygon object.
polygon_dissolve = polygon.dissolve(maxError=1)

# Print the result.
display('polygon.dissolve(...) =', polygon_dissolve)

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