HOTOSM disaster alerts

Python scripts and GitHub Actions workflows that post new disasters and disease outbreaks to the HOTOSM Slack #disaster-alerts channel.

• montandon-slack.py uses the IFRC Montandon STAC API to combine disaster alerts from GDACS, USGS, IBTrACS, Copernicus EMS, IFRC GO, GLIDE, EM-DAT and IDMC. It replaces the earlier standalone GDACS script.
• who-don-slack.py posts WHO Disease Outbreak News.

Montandon alerts

An alert requires at least one of:

• a GDACS Red alert
• a GDACS Orange alert (earthquake, cyclone, flood, volcano, drought, wildfire or tsunami)
• an earthquake of M7+, or M6.5+ in a named country where GDACS has not assessed it
• cyclone winds of 96 kt+ over a named country where GDACS has not assessed it
• at least 50 reported deaths or missing, 50,000 displaced or homeless, or 500,000 affected
• a Copernicus EMS rapid mapping activation

Modelled impacts, technological incidents and precautionary evacuations do not trigger alerts. An IFRC operation is noted but does not trigger an alert.

Records are grouped by hazard type, country, time (within 3 days), distance (within 500 km) and cyclone name. Separate GDACS Orange or Red events are never merged. Each group is anchored to one triggering record; other records must match that anchor directly. Modelled exposure is shown only as context.

Every qualifying alert is posted: GDACS Red, then Orange, then the rest, newest first within each. If more than 10 new alerts and updates qualify in one run, nothing is posted and the run fails, as this usually means bad data or thresholds. Updates are sent only for a higher GDACS level or a new reported death-toll order of magnitude (10, 100, 1,000).

State is stored in posted_montandon.json, one alert per line. Alerts no run has seen for 90 days are dropped. Live runs stop if state is missing or invalid, or if a Montandon search fails. Delivery is at-least-once: an alert may be reposted if Slack accepts it but the updated state is not pushed.

Going live

1. Add the MONTANDON_API_TOKEN secret (an IFRC GO API token).
2. Run the workflow once with seed_state enabled to record the current alerts.
3. Scheduled runs post live (every 6 hours). Set the MONTANDON_DRY_RUN repository variable to true to pause posting.

pip install requests
python -m unittest test_montandon.py
MONTANDON_API_TOKEN='...' DRY_RUN=true python montandon-slack.py