BULLETIN

BULLETIN (Boîte à oUtils opérationneLLe pour la prÉvision des impacTs des rIsques Naturels) is a Python toolbox for operational impact-based forecasting of natural hazards. The current repository supports meteorological hazards, river flooding, and pluvial flooding by combining forecast data, hazard thresholds, exposure information, and precomputed impact or flood-map datasets.

Workflow overview

Workflow	Purpose
workflows/bulletin_meteo_ibf.py	Processes one or more meteorological models, classifies forecast hazards, calculates impacts, and optionally merges the model results.
workflows/bulletin_flood_ibf.py	Runs the FloodPROOFS/HMC workflow: calculates discharge return periods, merges river flood maps, and estimates MUL-based impacts.
workflows/bulletin_glofas_ibf.py	Processes gridded discharge forecasts such as GLOFAS, compares them with return-period thresholds, and optionally produces administrative hazard and impact outputs.
workflows/bulletin_fanfar_ibf.py	Processes FANFAR river-section hydrographs, calculates section return periods, merges flood maps, and estimates MUL-based impacts.
workflows/bulletin_pluvial_hazard.py	Converts forecast rainfall accumulations into precomputed pluvial flood scenarios and administrative impact classes.
workflows/bulletin_hazard_to_impact.py	Recomputes impacts from an existing hazard product without rerunning the complete hazard workflow. It supports weighted flood overlays and classified meteorological hazards.

Supporting and legacy utilities

Script	Purpose
workflows/historical_flood_mapping.py	Historical or diagnostic FloodPROOFS mapping. It calculates return periods and flood maps but does not run the complete impact workflow.
workflows/bulletin_flood_make_river_network.py	Static-data utility for creating a river-network shapefile. Its paths and domains are currently hardcoded and must be adapted before use.

Repository structure

• common/: shared settings, logging, I/O, classification, grid, and time utilities.
• hydro/: river-flood return-period, hazard-mapping, and impact modules.
• meteo/: meteorological hazard, impact, and multimodel-merging modules.
• pluvial/: rainfall input, pluvial hazard, and administrative impact modules.
• static/: utilities used to prepare static flood datasets.
• workflows/: executable workflow entry points and example settings.

Installation

The reference environment is defined in environment.yml:

conda env create -f environment.yml
conda activate env_amhewas

The same core Python dependencies are also listed in requirements.txt.

Basic execution

Run workflows from the repository root so that the internal modules can be imported correctly.

python workflows/bulletin_flood_ibf.py \
    -settings_file workflows/bulletin_flood_ibf_settings.json \
    -time "2026-08-06 00:00" \
    -domain DOMAIN_NAME

Most workflows use the same -settings_file, -time, and optional -domain arguments. bulletin_meteo_ibf.py also supports model-specific execution and final multimodel merging. Use --help on each script for its complete command-line options.

Configuration files

Example configuration files are currently included for:

• FloodPROOFS/MUL: workflows/bulletin_flood_ibf_settings.json
• FANFAR: workflows/bulletin_fanfar_ibf_settings.json
• Meteorological IBF: workflows/bulletin_meteo_ibf_settings.json
• Pluvial hazard: workflows/bulletin_pluvial.json
• Historical FloodPROOFS mapping: workflows/historical_igad_d2.json

The GLOFAS and hazard-to-impact workflows require domain-specific settings files, which are not currently included as generic examples.

Outputs

Depending on the selected workflow and settings, BULLETIN can produce:

• gridded hazard or return-period rasters;
• merged flood maps;
• administrative hazard layers;
• exposed-element and impact shapefiles;
• classified impact levels;
• multimodel meteorological impact products.

All paths, thresholds, variables, exposed elements, return periods, and processing flags are controlled through the workflow settings files.