EU-CBM-HAT

The forest carbon model eu_cbm_hat is a python package that enables the assessment of forest CO2 emissions and removals under scenarios of forest management, natural disturbances, forest-related land use changes.

EU-CBM-HAT depends on the libcbm model developed by Forest Carbon Accounting team of the Canadian Forest Service. Both python modules use pandas data frames to transform and load data.

Documentation

The model was described in a 2022 JRC Technical Report called The JRC Forest Carbon Model: description of EU-CBM-HAT

See also

• Installation instructions below

• Software documentation at https://bioeconomy.gitlab.io/eu_cbm/eu_cbm_hat/eu_cbm_hat.html

Licence

This program is free software: you can redistribute it and/or modify it under the terms of the European Union Public Licence, either version 1.2 of the License, or (at your option) any later version. See LICENCE.txt and NOTICE.txt for more information on the licence of components.

Dependencies

• libcbm is a C++ library with python binding developed by the Canadian Forest Service. It is bundled into the libcbm_py python package available at https://github.com/cat-cfs/libcbm_py

• eu_cbm_data contains the model's input and output data located at https://gitlab.com/bioeconomy/eu_cbm/eu_cbm_data . In 2022, this is a private repository subject to ongoing research.

• eu_cbm_aidb contains the "Archive Index Databases" in a separate repository located at https://gitlab.com/bioeconomy/eu_cbm/eu_cbm_aidb

Installation

If you have never used python before and if you are on Windows, you might want to install Anaconda on your system, it will help you with managing packages dependencies. You also need to install git in order to install python packages from git repositories.

Install eu_cbm_hat using pip, the package installer for python in the shell on Linux or Mac or in the Anaconda prompt on windows.

pip install eu_cbm_hat
# or
python -m pip install eu_cbm_hat

Install libcbm using pip. Note: currently only version 1 is supported. Update to version 2 is under discussion in issue 53:

python -m pip install https://github.com/cat-cfs/libcbm_py/archive/refs/heads/1.x.tar.gz

By default, the data is located in your home folder. You can display the default location where the data should be with these commands in python:

>>> import eu_cbm_hat
>>> print(eu_cbm_hat.eu_cbm_data_dir)
>>> print(eu_cbm_hat.eu_cbm_aidb_dir)

	On Unix	On windows
Data	~/eu_cbm/eu_cbm_data/	C:\Users\user_name\eu_cbm\eu_cbm_data
Archive Index Database	~/eu_cbm/eu_cbm_aidb/	C:\Users\user_name\eu_cbm\eu_cbm_aidb

Please create the eu_cbm directory at the desired location on your system. The model will work once these folders exist on your system. If you don't want to use the default location, you can also define the environment variables EU_CBM_DATA and EU_CBM_AIDB to tell the model where the data and AIDB are located.

At a python prompt, copy test data to your local eu_cbm_data folder (location defined above in python in eu_cbm_hat.eu_cbm_data_dir):

>>> from eu_cbm_hat.tests.copy_data import copy_test_data
>>> copy_test_data()

Load AIDBs and link them to eu_cbm_data

The Archive Index Databases (AIDBs) are stored in a separate git repository that needs to be linked with the eu_cbm_data repository. Clone the repository containing the AIDBs inside your home folder in the parent directory of the path given by eu_cbm_hat.eu_cbm_aidb_dir. Back to the shell (or conda console):

cd eu_cbm
git clone https://gitlab.com/bioeconomy/eu_cbm/eu_cbm_aidb.git

Before running the model, you need to create AIDB symlinks at a python prompt:

>>> from eu_cbm_hat.core.continent import continent
>>> for country in continent: country.aidb.symlink_all_aidb()

Upgrade

Over time it's important to regularly upgrade the 2 packages with:

python -m pip install --upgrade eu_cbm_hat
python -m pip install --upgrade https://github.com/cat-cfs/libcbm_py/archive/refs/heads/1.x.tar.gz

You should also update the DATA and AIDB git repositories by pulling latest changes from those repositories.

In case you need to install the latest development version of eu_cbm_hat, use the --upgrade parameter and install from the main branch of the gitlab repository. That the --no-dependencies argument avoids reinstalling all dependencies as well:

python -m pip install --upgrade --force-reinstall --no-dependencies https://gitlab.com/bioeconomy/eu_cbm/eu_cbm_hat/-/archive/main/eu_cbm_hat-main.tar.gz

Installation for development purposes

Skip this section if you do not intend to change the code of the model. For development purposes, these instruction leave the capability to modify the code of the model and submit changes to the git repositories composing the model. Extensive installation instructions are available for two different platforms:

• Installation on Linux
• Installation on Windows

Running the model

Run the test country ZZ at a python prompt:

from eu_cbm_hat.core.continent import continent
runner = continent.combos['reference'].runners['ZZ'][-1]
runner.num_timesteps = 30
runner.run(keep_in_ram=True, verbose=True, interrupt_on_error=True)

See example of how to run the model for different countries in the scripts/running directory.

Run a scenario combination

Run a scenario combination for all EU countries at once (see the documentation on combos for how to specify them):

cd $HOME/eu_cbm/eu_cbm_hat/scripts/running/
ipython -i run_scenario_combo.py -- --combo_name reference --last_year 2050
ipython -i run_scenario_combo.py -- --combo_name pikssp2 --last_year 2070
ipython -i run_scenario_combo.py -- --combo_name pikfair --last_year 2070

Process the output data for a list of scenario combinations provided as an argument. Compute the harvest expected and provided as well as the sink in an aggregated way:

cd $HOME/eu_cbm/eu_cbm_hat/scripts/post_processing
ipython -i process_scenario_combo.py -- --combo_names reference pikssp2 pikfair

Read the model output

Inspect the output of the model

# Input events sent to libcbm
events_input = runner.input_data["events"]
# Events stored in the output including the ones related to the harvest
# allocation tool HAT
events_output = runner.output["events"]
# Available volumes used by the Harvest Allocation Tool
output_extras = runner.output.extras

# Load tables without classifiers
area = runner.output.load('area', with_clfrs=False)
params = runner.output.load('parameters', with_clfrs=False)
flux = runner.output.load('flux', with_clfrs=False)
state = runner.output.load('state', with_clfrs=False)

# Load classifiers with their actual values
classifiers = runner.output.classif_df
classifiers["year"] =  runner.country.timestep_to_year(classifiers["timestep"])

# Merge tables
index = ['identifier', 'year']
flux_dist = (params
             .merge(area, 'left', on = index) # Join the area information
             .merge(flux, 'left', on = index)
             .merge(state, 'left', on = index) # Join the age information
             .merge(classifiers, 'left', on = index) # Join the classifiers
             )

Further process the output

Instantiate a runner object. Note: this can be done after a model run, once the model has been run, no need to re-run the model at this point, since the output has been saved to the eu_cbm_data/output directory. The runner.post_processor method will read data from that directory.

from eu_cbm_hat.core.continent import continent
runner = continent.combos['reference'].runners['LU'][-1]

Compute the Net Annual Increment (NAI)

nai_lu = runner.post_processor.nai.df_agg(["status"])

Compute harvest expected and provided,

runner.post_processor.harvest.expected_provided("year")

Compute the sink.

runner.post_processor.sink.df_agg("year")

The above post processing methods can be computed for one country individually. They can also be computed for all countries together and saved in a parquet file for further analysis and comparison between different scenario combinations. For a given scenario such as "reference", save all post processing output for all countries to parquet files. This function implements all post processing steps.

>>> from eu_cbm_hat.post_processor.agg_combos import save_agg_combo_output
>>> save_agg_combo_output("reference")

Further checks for information:

• Check wood density and bark fraction in all countries:

    from eu_cbm_hat.post_processor.agg_combos import get_df_all_countries
    wood_density_bark_all = get_df_all_countries(
        combo_name="reference",
        runner_method_name="post_processor.wood_density_bark_frac"
    )
  

Testing

All dependencies are clearly stated in .gitlab-ci.yml and the setup.py files at the root of the repository. In fact those 2 files are used to automatically install and test the install each time we make a change to the model. The test consist in unit tests as well as running a mock country called "ZZ". You can see the output of these runs (successful or not) in the CI-CD jobs page on gitlab.

Model runs used in publications

• The model run used in the technical report

  • European Commission, Joint Research Centre, Rougieux, P., Pilli, R., Blujdea, V., Mansuy, N. and Mubareka, S.B., Simulating future wood consumption and the impacts on Europe's forest sink to 2070, Publications Office of the European Union, Luxembourg, 2024, https://data.europa.eu/doi/10.2760/17191, JRC136526.

  • Corresponds to the data at commit d7ddf2963666bc57360c6576e050e022d3b75e3f in branch run-ssp2-fair-v2023

Input data

Growth period

For the purpose of initializing the soil carbon pool, we use a different growth curve called the "Init" growth curve. That growth curve takes into account previous harvest and natural disturbances within the growth curve.

• Looking at the input inventory you will see a classifier called "growth period" which has the value "init" everywhere.

• See figure 3 of Pilli 2013 "Application of the CBM-CFS3 model to estimate Italy’s forest carbon budget, 1995–2020" for an explanation of the need to switch from an init growth period to a current growth period. The Simulation.switch_period() method changes the growth period from "Init" to "Cur". As a result all stands will have the value "Cur" for the groth_period classifier from inventory start year onwards. Note the inventory start year is specified in runner.country.inventory_start_year.

Definitions and specification

• A specification for an Harvest Allocation Tool (HAT) is available at docs/harvest_allocation_specification.md

• Input files (disturbances, yield, inventory) defined in eu_cbm_data contain scenarios for the activities (afforestation, deforestation, reforestation, disturbances in forest remaining forest, wood use specified in the silviculture and product_types.csv tables)

Extra documentation

More documentation is available at: https://bioeconomy.gitlab.io/eu_cbm/eu_cbm_hat/eu_cbm_hat.html

This documentation is simply generated in .gitlab-ci.yml with:

$ pdoc -o public ./eu_cbm_hat