1.1. Installing QGIS

There are different ways to install QGIS, depending on whether you need any external processing toolboxes tuch as SAGA, GDAL or GRASS. We need SAGA and it is nice to be able to have a look at GRASS plugins, so we will use the OSGeo4W installation method for win. For other systems, such as osx OSX or nix , install normally as outlined on the QGIS downloads page <https://qgis.org/en/site/forusers/download.html>

  1. Go to the QGIS download page and click the OSGeo4W Network installer.

  2. Run the installer as administrator

    To run as administrator, press the windows key, search for osgeo4w-setup.exe, click the arrow and press run as administrator

  3. Select Express install

  4. now select

    1. unchecked QGIS

    2. checkbox QGIS LTR

    3. checkbox GDAL

    4. checkbox GRASS GIS

  5. finish the installation normally. This should install QGIS 3.22.

1.1.1. Installing QRichDem

QRichDem is a plugin that makes RichDEM available to QGIS. I wrote it myself and will be testing it this class. Especially osx OSX has not been tested yet. It will install the package using pip, which may not be available if you first installed QGIS. If you encounter any errors, see Manually installing pip

  1. open up QGIS

  2. Install the QRichDem plugin following the installation instructions

    It will take some time to install RichDEM, so do not close QGIS while installing.

  3. If everything worked out, you should have the RichDEM toolbox

    Richdem toolbox with depression breaching, filling, flow accumulation and terrain attributes algorithms.

1.1.2. Manually installing pip

pip is a tool that installs Python packages. RichDEM is a python package that is not included in QGIS, so in order to install RichDEM, we need pip. However,

1.1.2.1. nix osx

Make sure you have not activated any environment. If you do not know what virtual environments or conda means, that probably means you do not have them installed. QGIS installs all its requirements in the system environment, so that is also where we want pip installed.

in a terminal, type:

python3 -m ensurepip --upgrade
python3 -m pip install richdem

This also install richdem itself.

1.1.2.2. win

  1. Open the osgeo4w setup, again, as administrator. This time choose radioButtonOn advanced install. Follow the instructions until the Select Packages screen. There, search for “pip”, click the + icon and click the turning arrows symbol to select the highest available version.

    the Select Packages screen, with "pip" highlighted in the search bar, as well as the turning arrows symbol

  2. continue the rest of the installation and continue Installing QRichDem

  3. If it still does not work, open the OsGEO4W shell and type in there:

    python3 -m pip install richdem