Update installation instructions

README.rst

@@ -37,6 +37,9 @@ The ``geefcc`` package depends on the `xee <https://github.com/google/Xee>`_ Pyt
 Prerequisites
 =============
 
+Access to Google Earth Engine
+-----------------------------
+
 To use the ``geefcc`` Python package, you need a Google account and an `access to Earth Engine <https://developers.google.com/earth-engine/guides/access#a-role-in-a-cloud-project>`_ either via a Google Cloud project that's registered to use Earth Engine or via an individually signed-up account. Please follow this link `to register for Earth Engine <https://code.earthengine.google.com/register>`_.
 
 You must always initialize GEE before using ``geefcc`` functions specifying a Google Cloud project name and `Earth Engine high-volume endpoint <https://developers.google.com/earth-engine/cloud/highvolume>`_:
@@ -49,33 +52,76 @@ You must always initialize GEE before using ``geefcc`` functions specifying a Go
       opt_url="https://earthengine-highvolume.googleapis.com"
     )
 
+GDAL
+----
+
+GDAL must be installed on your system.
+
+To install GDAL on Windows, use the `OSGeo4W <https://trac.osgeo.org/osgeo4w/>`_ network installer. OSGeo4W is a binary distribution of a broad set of open source geospatial software for Windows environments (Windows 11 down to 7). Select *Express Install* and install GDAL. Several Gb of space will be needed on disk to install this programs. This will also install *OSGeo4W Shell* to execute command lines.
+
+To install GDAL on other systems, use your package manager, for example ``apt`` for Debian/Ubuntu Linux distributions.
+
+.. code:: shell
+
+    sudo apt update
+    sudo apt install gdal-bin libgdal-dev
+
+After installing GDAL, you can test the installation by running ``gdalinfo --version`` in the command prompt or terminal, which should display the installed GDAL version.
+
+GADM website
+------------
+
 The ``geefcc`` package downloads country administrative borders from the `GADM <https://gadm.org/data.html>`_ website. From time to time, their server is not responding. In case of problem with downloading country borders, check directly on the GADM website that data can be downloaded manually to be sure that the problem is coming from ``geefcc``.
 
 Installation
 ============
 
-The easiest way to install the ``geefcc`` Python package is via `pip <https://pip.pypa.io/en/stable/>`_:
+The easiest way to install the ``geefcc`` Python package is via `pip <https://pip.pypa.io/en/stable/>`_ in the *OSGeo4W Shell* for Windows or in a virtual environment for Linux.
+
+For Linux, create and activate a virtual environment before install ``geefcc`` with ``pip``:
+
+.. code-block:: shell
 
-.. code-block:: bash
+   cd ~
+   # Create a directory for virtual environments
+   mkdir venvs
+   # Create the virtual environment with venv
+   python3 -m venv ~/venvs/venv-geefcc
+   # Activate (start) the virtual environment
+   source ~/venvs/venv-geefcc/bin/activate
 
-   $ # For last stable version on PyPI
-   $ python -m pip install geefcc
+Install Python dependencies and ``geefcc`` in the *OSGeo4W Shell* or in the newly created virtual environment:
+
+.. code-block:: shell
+   
+   # Upgrade pip, setuptools, and wheel
+   python3 -m pip install --upgrade pip setuptools wheel
+   # Install numpy
+   python3 -m numpy
+   # Install gdal Python bindings (the correct version)
+   python3 -m pip install gdal==$(gdal-config --version)
+   # Install geefcc. This will install all other dependencies
+   python3 -m pip install geefcc
 
-or 
+If you want to install the development version of ``geefcc``, replace the last line with:
 
-.. code-block:: bash
+.. code-block:: shell
 
-   $ # For development version on GitHub
-   $ python -m pip install https://github.com/ghislainv/geefcc/archive/master.zip
+   python3 -m pip install https://github.com/ghislainv/geefcc/archive/master.zip
 
-but you can also install ``geefcc`` executing the ``setup.py`` file:
+To deactivate and delete the virtual environment:
 
-.. code-block:: bash
+.. code-block:: shell
+		
+   deactivate
+   rm -R ~/venvs/venv-geefcc # Just remove the repository
 
-   $ git clone https://github.com/ghislainv/geefcc
-   $ cd geefcc
-   $ python setup.py install
+In case of problem while installing GDAL Python bindings, try the following command:
 
+.. code-block:: shell
+		
+   python3 -m pip install  --no-cache-dir --force-reinstall gdal==$(gdal-config --version)
+   
 Contributing
 ============