Segmentation¶
Summary¶
Disaggregate fluvial units (polygons or polylines) in DGO of chosen size.
Tags:dgo, polygon, polyline, segmentation, transect, vector, disaggregation, centerline
Usage¶
Prior to assess metrics to characterize a fluvial system, fluvial units have to be disaggregated. This step enables to discretize a continuum with a constant length in order to provide a higher resolution for characterizing fluvial units. The constant length must be set precisely to ensure spatial trends or relationships between several variables to be correctly detected either at a network scale or at a local scale. Spatial disaggregation can be run both for linear (e.g. hydrographic network, centerline) and polygon feature (valley bottom, active channel).
[@roux2014]
Algorithm:
if input type is polyline
run segmentize algorithm
elif input type is polygon
if a centerline is provided
calculate a AXIS FID field on centerline
run disaggregate polygon algorithm
Parameters¶
| Parameter | Description | Type |
|---|---|---|
Input features to segment
INPUT
|
The feature to be segmented | Polygon, MultiPolygon, LineString or MultiLineString |
Centerline of the polygon to segment
CENTERLINE
(Optional)
|
Useful in case of a polygon feature to segment and relates to the centerline of this input feature. | LineString or MultiLineString |
Segmentation step
STEP
|
User-defined constant length used to disaggregate
the input feature (in map unit).
Default value: 25.0
|
Number |
Segmented features
OUTPUT
|
The segmented output feature. | Polygon or LineString (depend of input type) |