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Plugin Analisi geomorfologica

dem_analysis The Raster Terrain Analysis Plugin can be used to calculate the slope, aspect, hillshade, ruggedness index and relief for digital elevation models (DEM). It is very simple to handle and provides an intuitive graphical user interface for creating new raster layers (see Figure_raster_terrain_1).

Descrizione delle analisi:

  • Slope: Calculates the slope angle for each cell in degrees (based on first- order derivative estimation).

  • Esposizione: 0 gradi per nord e continuando in senso orario.

  • Hillshade: Creates a shaded map using light and shadow to provide a more three-dimensional appearance for a shaded relief map. The output map is a Single band gray reflecting the gray value of the pixels.
  • Ruggedness Index: A quantitative measurement of terrain heterogeneity as described by Riley et al. (1999). It is calculated for every location by summarizing the change in elevation within the 3x3 pixel grid.
  • Relief: Creates a shaded relief map from digital elevation data. Implemented is a method to choose the elevation colors by analysing the frequency distribution. The output map is a multiband color with three bands reflecting the RGB values of the shaded relief.

Figure Raster Terrain 1:

../../../_images/raster_terrain_dialog.png

Plugin Analisi geomorfologica (calcolo pendenza)

Usare il plugin

  1. Start QGIS and load the gtopo30 raster layer from the GRASS sample location.
  2. Load the Raster Terrain Analysis plugin in the Plugin Manager (see La finestra di dialogo Plugins).
  3. Select an analysis method from the menu (e.g., Raster ‣ Terrain Analysis ‣ Slope). The Slope dialog appears as shown in Figure_raster_terrain_1.

  4. Specificare nome, percorso e formato del file di output.

  5. Cliccare su [OK].