QGIS Plugin Installation

Install QGIS

Windows

We recommend installing Python, GDAL and QGIS from OSGeo4W. If you have OSGeo4W and GDAL/QGIS installed but just need the extra Python tools you can re-run the following method to obtain the extras.

Run osgeo4w-setup.exe, located by default in C:\OSGeo4W\bin.

• Run the Installer application
• Select Advanced Setup and continue.
• Select Install from Internet and continue.
• Select your existing Root Directory and preferences until you reach a screen showing lots of packages that can be installed.
• Search for gdal, toggle to Full View. The first column will show you your installed version – note down the number – it should look like e.g. "gdal 3.11.3" (Note the version number on your system is likely to be different). We will need the version number of your GDAL installation in a later step.
• (If you have GDAL already installed the version number can be checked with the command gdalinfo --version from the OSGEO4W shell)
• Enter the Advanced section.
• Choose python3-gdal and python3-gdal-dev from the advanced section and swap from "skip" to "keep".
• Likewise from the packages section choose qgis from "skip" to "keep".
• Check whether pip is installed; if not, mark it for installation.
• Complete the installation.

(See here or Install/QGIS_Avaframe_MoT.docx for additional info and images if the above is not clear.)

Linux

To check which version of gdal is on the system (and that the development tools are in place) use

sudo apt install gdal-bin libgdal-dev python3-gdal qgis

we can check the version of gdal with

gdal-config --version

macOS

GDAL is available via homebrew.

To install homebrew, open Terminal and use the following command

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

We then install GDAL and QGIS with

brew install gdal qgis

Check the version with

gdal-config --version

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Install Dependencies

For Avaframe to work we need to open QGIS with additional packages installed so the python inside QGIS can use them.

requirements.txt

Firstly we need to tell python which version of GDAL is installed on your system. To do this edit the line in requirements.txt so it matches the version of GDAL installed i.e. if your GDAL is 3.11.3 then change the line

gdal==3.8.4 ; python_version >= "3.11" and python_version < "3.13"

to

gdal==3.11.3 ; python_version >= "3.11" and python_version < "3.13"

Windows

Open the OSGEO4W shell. Run the following line

python -m pip install -r <path to project directory>\requirements.txt

This will install the dependencies for both Avaframe and the preprocessing tools. Now the python used by QGIS can access the installed packages.

Next we can now open QGIS with the command

qgis

Linux and Mac

QGIS uses different python versions depending on whether you have opened it via the desktop or from an environment (e.g. from the terminal). To get around this and ensure that the packages are available for whichever python QGIS wants to use we need to expose the packages to our PATH variable.

If you know for sure which version of python QGIS is using on your system (you can check this through the python terminal within QGIS: import sys; print(sys.executable)). We can then install requirements directly to this python e.g. /usr/bin/python3 -m pip install --force -r requirements.txt. However, this is not recommended as it can break your system python and other packages may break due to the requirements for this package.

The workaround for this is to create an isolated virtual environment for the project so that all required dependencies are installed locally and don’t interfere with your system Python. This happens in the OSGEO4W shell already in the Windows installation as the python QGIS uses is isolated there. For those on Linux and Mac we need to expose the packages to whichever python QGIS wants to use.

poetry

To install poetry we do (either using apt or brew)

sudo apt install pipx
pipx install poetry

Once poetry is installed you can simply type

poetry install --no-root

and all dependencies will be fetched into an environment for you.

Python std venv

If poetry is not available for you then we can do the following. Create a new virtual environment (named .venv)

python -m venv .venv

Activate the environment:

source .venv/bin/activate

Once activated, install all dependencies listed in requirements.txt into the new environment:

python -m pip install --upgrade pip
python -m pip install -r requirements.txt

Finally, confirm that the installation worked by listing the installed packages:

python -m pip list

Open QGIS with environment

Now we can run the script qgis-poetry.sh which will expose the site-packages in the virtual environment so any python QGIS is using can see them.

chmod +x qgis-poetry.sh
./qgis-poetry.sh

This will open QGIS with the specific dependencies for Avaframe and the preprocessing tools exposed so the plugin can use them.

For ease of future use you can make an alias to this script which will make a global command to open QGIS from the terminal. Edit the following line to where you have installed the project. If using zsh on mac swap to .zshrc as appropriate.

echo "alias avaframeQGIS='<path to script>/qgis-poetry.sh'" >> ~/.bashrc

The command avaframeQGIS will then open QGIS with the avaframe requirements whenever you need it.

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Installing the Avaframe and RasterOps Plugins

Open QGIS using the method described above that works for you. Install the plugin via

QGIS top menu -> Plugins -> Manage and Install Plugins -> Install from ZIP

Drag and drop the ZIP file Install/RasterOpsPlugin.zip into the path and click install.

For Avaframe search for Avaframe from the install from Web tab. Click install.

Now both plugin will be installed and able to run.

Using the Plugins

Avaframe

Load any layers you wish to manipulate into QGIS (drag and drop files into the staging area).

Open the processing toolbox. Select the MoT Voellmy tool

Avaframe - NGI_Experimental - MoTVoellmy (Com9)

In the popup menu select the options you wish and add relevant rasters then click run. Results will appear in the staging area.

RasterOps

Load any layers you wish to manipulate into QGIS (drag and drop files into the staging area).

Click the RasterOps button in the top menu.

• Select an operation.
• Select relevant layers
• Hit Run

Your processed raster results will appear in the staging area.

Recipes

The tool is designed such that general operations are available at top level but specific "recipes" (combinations of operations that are likely more frequently used or more complex operations than simple raster combinations e.g. calculating variable friction parameters for the terrain or combining forest data files into the correct format and scale) are stored under the recipes subheading. This allows us to write specific more complex routines which can take in, process and return rasters.