[This is the third post in my series on hillshades: previous ones were on the functionality of QGIS Terrain Shading module and some ramblings on the combination of multiple hillshades.] [Read More]
Hillshade in QGIS: how does it work ?
As implemented in Terrain Shading module
Figure 1. Hillshade model of Požega valley (Croatia). [Read More]
Visibility index (total viewshed) for QGIS : finally there!
Welcome visibility index algorithm, a.k.a. total viewshed, now available in QGIS Visibility analysis plugin. This metric informs us on the size of the visual field for any location across a given terrain, normally each pixel in a gridded digital elevation model (DEM). At first, visibility index resembles other terrain indices... [Read More]
Name the enemy: geographic projections in GIS
Projecting rasters in QGIS
So, you have your data, you’ve installed a GIS program … and there we go: slope gradient – check, solar exposition – check, water drainage – check, visibility range – check … [Read More]
Distance and direction filters for QGIS Viewshed analysis
Viewshed analysis produces a model of visible areas from a chosen point, given a 2.5 or 3D elevation model. Most often, we model full range visibility, in all directions from an observer point, but such models may not satisfy all uses. For instance, we are sometimes interested in a scene... [Read More]