Cliffs, boulders, knolls - JiriVales/automatic-creation-orienteering-map GitHub Wiki

Create cliffs

Model Create cliffs Picture: Model Create cliffs

Algorithm description

Finding cliffs using slope.
Used tools: Slope (GDAL), Raster calculator (GDAL), Polygonize (raster to vector), Extract by attribute, Field calculator, Fill holes, Polygons to lines, v.generalize, Lines to polygons

Input parameters

Digital elevation model (raster)
Raster representing the height of the terrain.
Formula for extract cliffs from Slope
Formula for extract cliffs from slope raster.
1*(A>X), where X is number (degrees) of minimum slope of cliffs. For example: 1*(A>25), cliffs have got slope greater than 25 degrees. Decimal number must be with dot (f.e. 29.5). A = slope raster.
Default value: 1*(A>25)
Minimum area of cliff (meters)
Number of the minimum area of individual cliffs.
Format: number
Units: meters
Default value: 18
Maximum area of cliff (meters)
Number of the maximum area of individual cliffs.
Format: number
Units: meters
Default value: 500
Maximum distance (meters) between the original and the simplified curve (Douglas–Peucker algorithm)
Parameter for curve simplification using the Douglas-Peucker algorithm. The number specifies the maximum distance of the simplified curve from the original.
Format: number, integer (1-50)
Units: meters
Default value: 3
Distance (meters) between the created points (Hermite Spline Interpolation)
Curve smoothing parameter using Hermite Spline interpolation. Distance between the created points.
Format: number, integer (1-50)
Units: meters
Default value: 3
Minimum angle between two consecutive segments in Hermite Spline Interpolation
Curve smoothing parameter using Hermite Spline interpolation. Minimum angle.
Format: number, integer (1-10)
Units: angle
Default value: 3

Outputs

Cliffs
Cliffs, impassable cliffs, earth banks
Format: vector, polygons Created cliffs (red) Picture: Created cliffs (red)

Create large boulders

Model Create large boulders Picture: Model Create large boulders

Algorithm description

Finding large or gigantic boulders.
Used tools: Slope (GDAL), Raster calculator (GDAL), Polygonize (raster to vector), Extract by attribute, Field calculator, Fill holes, Polygon centroids, Fixed distance buffer, Extract by location, Polygons to lines, Lines to polygons, Dissolve, Difference

Input parameters

Digital elevation model (raster)
Raster representing the height of the terrain.
Formula for extract boulders from Slope
Formula for extract boulders from slope raster.
1*(A>X), where X is number (degrees) of minimum slope of bouders. For example: 1*(A>20), boulders have got slope greater than 20 degrees. Decimal number must be with dot (f.e. 29.5). A = slope raster.
Default value: 1*(A>20)
Minimum area of boulder (meters)
Number of the minimum area of individual boulders.
Format: number
Units: meters
Default value: 5
Maximum area of boulder (meters) Number of the maximum area of individual large boulders.
Format: number
Units: meters
Default value: 144
Half distance between the centers of two boulders (meters)
Half distance between the centers of two large or gigantic boulders.
Format: number (2.0 - 50.0, can be decimal)
Units: meters
Default value: 6
The maximum distance between the center and the edge of the boulder (meters)
The maximum distance between the center and the edge of the large or gigantic boulder.
Format: number (1.0 - 50.0, can be decimal)
Units: meters
Default value: 6

Outputs

Large_boulders
Large or Gigantic boulders
Format: vector, points Identification of large boulder Picture: Identification of large boulder (from slope to boulder) Created large boulders Picture: Created large boulders

Create small knolls and form lines of knolls

Model Create small knolls and form lines of knolls Picture: Model Create small knolls and form lines of knolls

Algorithm description

Finding small knolls, small elongated knolls, boulders and bigger knolls which will be represented as form lines (auxiliary contour lines).
Used tool: Invert grid, Find depression area, Lines to polygon, Field calculator, Extract by location, Dissolve, Extract by attribute, Polygon centroids, Polygons to lines

Input parameters

Digital elevation model (raster)
Raster representing the height of the terrain.
Format: raster
Formula to distinguish knolls and auxiliary contours
Formula to distinguish knolls/boulders (points) and auxiliary contours (lines).
if((Round("area"))<=X,1,2), where X is maximum area of knoll/boulders (meters) represented as point. X can be integer (f.e. 22) or decimal number (f.e. 25.5).
Default value: if((Round("area"))<=22,1,2)
(Maximul area of knoll as point is 22 meters.)
Half distance between the centers of two knolls (meters)
Half distance between the centers of knolls or boulders.
Format: number (2.0 - 50.0, can be decimal)
Units: meters
Default value: 3.0
Maximum radius of knoll (meters)
The maximum distance between the center and the edge of the knoll.
Format: number (1.0 - 50.0, can be decimal)
Units: meters
Default value: 13.5

Outputs

Form_lines_knolls
Form lines of knolls (auxiliary contour lines).
Format: vector, polyline
Knolls
Small knolls, small elongated knolls, boulders.
Format: vector, point Created knolls/boulders (red points), form lines of knolls (red lines) Picture: Created knolls/boulders (red points), form lines of knolls (red lines)

Removal of collisions of knolls with cliffs

Model Removal of collisions of knolls with cliffs
Picture: Model Removal of collisions of knolls with cliffs

Algorithm description

Removal of collisions of small knolls/boulders with cliffs.
Used tools: Fixed distance buffer, Extract by location, Polygon centroids, Difference

Input parameters

Layer of cliffs (polygons)
Layer of cliffs.
Format: vector, polygon
Layer of small knolls (points)
Layer of small knolls or bouders
Format: vector, points
Radius of knoll (meters)
Maximum radius of knoll or minimum distance between center of knoll and cliffs.
Format: number (0.5 - 50.0, can be decimal)
Units: meters
Default value: 3.0

Outputs

Knolls
Knolls without collisions with cliffs.
Format: vector, points

Removal of collisions of knolls with large boulders

Model Removal collisions of knolls with large boulders Picture: Model Removal collisions of knolls with large boulders

Algorithm description

Removal of collisions of small knolls/boulders with large/gigantic boulders.
Used tools: Fixed distance buffer, Extract by location, Polygon centroids, Difference

Input parameters

Layer of large boulders (polygons)
Layer of large or gigantic boulders.
Format: vector, polygon
Layer of small knolls (points)
Layer of small knolls or bouders
Format: vector, points
Radius of knoll (meters)
Maximum radius of knoll.
Format: number (0.5 - 50.0, can be decimal)
Units: meters
Default value: 3.0
Radius of large boulder (meters)
Maximum radius of large boulders.
Format: number (0.5 - 50.0, can be decimal)
Units: meters
Default value: 4.5

Outputs

Knolls
Knolls without collisions with large boulders.
Format: vector, points