https://www.youtube.com/watch?v=MudknS9d-y0
Spatial analysis is a powerful set of techniques that allow users to manipulate and analyze geographic data, making it easier to combine and extract meaningful information from different datasets on a map.
To apply a transformation from the Spatial Analysis toolset to a layer, simply click on the layer in the legend top open the style editor, then click on the Transform icon (two overlapping circles) under the layer name.
The transformations menu is also available via the Felt menu in top-left corner and via feature menu using the Command/Control + K shortcut (simply type Transform or the name of any specific transformation, like Buffer).
<aside> 💡 Processing large layers will take a long time. Consider clipping large layers to your area of interest before running other operations.
If you don’t have a layer to clip to, you can create an area of interest as an element by using the circle or polygon tools and then applying the Convert to layer action on it.
</aside>
The following transformations are currently available:
| Name | Description | Example use case | Input | Output |
|---|---|---|---|---|
| Buffer | For each feature, generate a polygon covering an area within a distance | To identify specific locations that are within a certain radius of features like roads, hospitals, etc. | Any | Polygons |
| Bounding Box | For each feature, generate a rectangular polygon completely covering the feature | To simplify features to broad coverage areas | Any | Polygons |
| Centroid | For each feature, generate a point at the center of it | To simplify a polygon layer to a point layer, like metro areas to just cities | Lines or polygons | Polygons |
| Clip | Keep only the parts of each feature inside polygons from another layer | To reduce a global or countrywide layer to just an area of interest | Any and polygons | Any (same as input) |
| Count Points in Polygons | Add the total number of points covered by each polygon to each feature | Count the number of airports in each US state | Points and polygon layers | Polygon layer with number of points as an attribute |
| Dissolve | Create a single new polygon covering all features | To simplify overlapping or contiguous polygons, like buffers | Polygons | Polygons |
| Intersect | Keep only the features in layer A that intersect layer B | To identify features that overlap another layer, like roads inside national parks | Any and polygons | Any (same as input) |
| Subtract | Keep only the parts of each feature outside the polygons from another layer | Remove flood zones from candidate areas for development projects | Any and polygons | Any (same as input) |
| Join | For each feature, generate a new one that includes the columns from both input layers | To add non-geographic data to a geographic layer, like GDP per year to a countries layer | Any and any | Any (same as input) |
<aside> 💡 Try out Felt’s spatial analysis tools for yourself in this step-by-step tutorial to find suitable habitat for the Iberian Lynx!
Download the datasets: https://drive.google.com/drive/folders/1eKmVEg1hZk8TlVnQPu150oaTQNu07YkX
</aside>