The SAGA Raster calculator is useful because it allows to make some calculations that the regular QGIS Raster Calculator does not. Especially, it allows us to use the X and Y coordinates of the raster as inputs for our calculations. How do we start?
Short answer: your GIS software needs to fill the blanks in the area with NoData pixels. Long answer: I will demonstrate what happens by an example on QGIS 3.18, and show why the final raster tends to be larger than the other two summed.
One of the simplest yet most tricky ways of doing batch processing is by using Bash scripts. Bash is a type of Shell Script, which means it runs directly on a user interface that accesses the services of an operating system.
Today, the post is about how to generate the raster for Vertical Distance to Channel Network (VDCN) using QGIS Raster Calculator, and SAGA on QGIS or command line interface (CLI), step-by-step. Vertical Distance to Channel Network (VDCN) is the vertical distance to the interpolated Channel Network, or the river network of the location.
Last week, we talked a little about using SAGA on Command Line. Today, I am discussing solutions to the problem “Error: Catchment Area” on SAGA GIS. Or “Error: your input raster”, or “Input layers do not have the same grid extent”.
SAGA also has its own Graphical User Interface (GUI). And it also has its own Command Line version. One may ask, why would someone deliberately choose to use a Command Line version in detriment of a GUI? Well, a GUI uses its own share of memory, CPU, sometimes GPU, to run.