Contents
How to identify ridgelines from a Dem-Esri?
This workflow uses Map Algebra and the Hydrology Toolset to derive ridgeline features from a DEM. Fill the DEM using the Fill tool in the Hydrology Toolset. For more information on the Fill tool read Creating a depressionless DEM.
How to convert contour lines to Dem in grass?
GRASS GIS’ r.surf.contour module is specifically built for converting contour lines into DEMs, and in general it does a rather nice job at it. Important: be sure to restrict the computational region to the area of interest, otherwise computations will be slow.
How to calculate the flow direction of a Dem?
Run the Flow Direction tool using the output raster from step 2 as the ‘Input surface raster’ and checking ‘Force all edge cells to flow outward’. For more information on this tool read Flow Direction (Spatial Analyst). Run the Flow Accumulation tool using the output raster from step 3 as the ‘Input flow direction raster’.
How to rasterize contour lines in r.surf?
A number of the r.surf.* modules want the input data to be in raster form already, so we rasterize the contour lines, using the level column for the height values.
How do you create a stream network raster?
Set the Flow Accumulation threshold and create the stream network raster using the Raster Calculator. Create a Stream Order raster using the stream network raster (step 5) for the ‘Input steam raster’ and the Flow Direction raster (step 3) for the ‘Input flow direction raster’. For more information on this tool read Stream Order (Spatial Analyst).
What happens when you rasterize a glyph?
To rasterize the glyph essentially means to turn on all pixels inside the scaled outline. Doing so naïvely results in the above raster tragedy: disjoined arches, unequal stems, missing serifs, etc. What went wrong? Control point coordinates are integers. There are no decimal places or fractional numbers.