Spatial analysis

Join, buffer, dissolve, clip, and intersect layers, and create travel-time areas, with the Analysis tool.

Task	Plans
Run an analysis, combine layers, and clip a layer	Team, Business, and Enterprise
Create travel-time areas	Business and Enterprise
Crop a raster layer	Business and Enterprise
Sample raster	Business and Enterprise

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Spatial analysis creates a new layer from one or two map layers, leaving the inputs unchanged. The Analysis tool runs operations such as join, buffer, clip, and travel time.

For an operation the Analysis tool doesn't have, such as finding the nearest feature or summing point values in each polygon, ask Felt AI. See Query map layers with SQL.

Create travel-time areas

A travel-time area, or isochrone, shows how far you can travel by car, bike, or on foot in up to 120 minutes. The Travel time operation creates a layer with one area for each point and travel time.

1. Click Analysis in the toolbar and select Travel time.

2. In Measure travel time from, select a point layer.

3. In Mode, select Drive, Walk, or Bike.

4. In Travel time, enter the minutes. To add another time, such as 10, 20, and 30 minutes, click Add travel time. You can add up to five.

5. Click Apply. The result appears in the legend as a new layer.

One run can create up to 10,000 areas, counting each point once for each travel time. For more, filter the layer, use fewer travel times, or select Features on screen in Apply to. To check one place, use the Travel time type in Measure. You can also ask Felt AI, such as "Show the area within a 15-minute walk of each school". For straight-line distance, use Buffer.

Run an analysis

1. Click Analysis in the toolbar.

2. Select an operation, such as Buffer. The Analysis panel opens.

3. Select the input layer. For an operation that compares two layers, select the second layer too.

4. In Settings, set the operation's options.

5. Optional: In Apply to, select Features on screen to analyze only the current map view. For layers larger than 500 MB, this is the default.

6. Click Apply. The result appears in the legend as a new layer.

Analysis uses only features that pass a layer's filters. See Filter layers.

Analysis results are created once and don't update when an input layer refreshes. For results that stay current, connect a data source, define a SQL query, and turn on live refresh. Results count toward processing. See Plan usage.

Combine layers

Use Join to combine attributes or Dissolve to merge polygons. To stack features from two layers into one, ask Felt AI; the Analysis tool can't append layers.

Join

Join adds one layer's attributes to another by matching values in each layer's join key column. For example, both layers might have a tract ID column. Join matches values, not locations; to combine by location, use Intersect or Count points.

1. In the toolbar, click Analysis > Join.

2. Under Join data and geometry from…, select the layer whose shapes you want in the result and its Join key column.

3. Under … with data from, select the second layer and its Join key column. This layer can be a table with no geometry.

4. Optional: Under … and keep unmatched rows from, clear a layer to drop its unmatched rows. Both layers are selected by default, so every row is kept.

5. Click Apply.

Join key values must match exactly, so check spelling and format first. To attach a spreadsheet to places such as counties or ZIP codes, see Spreadsheets and geocoding.

Dissolve

Dissolve merges polygons in one layer and removes the boundaries between them. For example, it can merge a property's parcels. In Combine, select All features (the default) to make one polygon, or Overlapping features to make one polygon per group of overlapping or touching features.

Dissolve doesn't group by an attribute, so first filter the layer to the polygons you want. To dissolve polygons from two layers, first combine the layers with Felt AI.

Clip a layer to a boundary

Clip trims a point, line, or polygon layer to the polygons of a second layer and keeps the input layer's attributes. For example, clip roads to a county boundary.

1. In the toolbar, click Analysis > Clip.

2. Under Cut out data from…, select the layer to trim.

3. Under … where it overlaps with, select the boundary layer. It must be a polygon layer.

4. Click Apply.

To clip a layer to an annotation, such as a polygon you drew, select the annotation, right-click, click Actions > Convert to layer, and use that layer as the boundary. The basemap can't be clipped; to mask land or water, use a land or water polygon layer.

Crop a raster layer

Clip doesn't support raster layers. To crop a raster, add the Spatial filter extension from Developer Platform in the toolbar. Draw a shape in view mode, then export the raster from the filter panel as a GeoTIFF clipped to that shape. On the map, the filter hides pixels outside the shape only for you. See Spatial filter.

Sample raster writes raster values into a vector layer; it doesn't produce a raster.

Sample raster

Sample raster adds raster values to a point, line, or polygon layer as new attributes. For example, it can calculate each parcel's average elevation, a type of zonal statistic.

1. In the toolbar, click Analysis > Sample raster.

2. Under Calculate statistics for each feature of…, select the vector layer.

3. In Raster layer, select the raster.

4. In Bands, select the bands to read.

5. Select the statistics, such as Average, or Most common for categories such as land cover.

6. Click Apply.

Analysis operations

Operation	What it does	Example use	Input	Second layer	Output
Buffer	Draws a polygon covering everything within a set distance of each feature, in ft, mi, m, or km	Find places within half a mile of a hospital	Points, lines, or polygons	None	Polygons
Bounds	Draws the smallest rectangle around each feature	Simplify detailed shapes to broad coverage areas	Lines or polygons	None	Polygons
Centroid	Places a point at the center of each feature, keeping its attributes	Turn metro area polygons into points	Lines or polygons	None	Points
Dissolve	Merges all polygons into one, or merges groups of overlapping or touching polygons	Merge overlapping buffers into one area	Polygons	None	Polygons
Clip	Keeps the parts of each feature inside the second layer's polygons, preserving the input layer's attributes	Cut a countrywide layer down to your area of interest	Points, lines, or polygons	Polygons	Same as input
Intersect	Creates one feature per overlap, with attributes from both layers	Find the roads inside national parks	Points, lines, or polygons	Polygons	Same as input
Subtract	Removes the parts of each feature inside the second layer's polygons	Remove flood zones from candidate development sites	Points, lines, or polygons	Polygons	Same as input
Count points	Adds the number of points inside each polygon	Count the airports in each US state	Polygons	Points	Polygons
Join	Adds a second layer's attributes by matching values in a column from each layer	Add GDP figures from a table to a countries layer	Any layer or table	Any layer or table	First layer's geometry
Sample raster	Adds raster values or statistics to each feature	Find the average elevation of each parcel	Points, lines, or polygons	A raster layer	Same as input
Travel time	Draws the area you can reach from each point in a set time by car, bike, or on foot	Find the area within a 15-minute walk of each school	Points	None	Polygons

Try the spatial analysis exercise

The spatial analysis exercise finds habitat for the Iberian lynx. Download the datasets, then follow the video.