2024 Cyclone Chido
| General Information | ||||||||||||||
Context of the Activation Intense Tropical Cyclone Chido was a small but very powerful and destructive tropical cyclone which impacted Southeast Africa in December 2024. Chido made landfall at Agaléga in Mauritius on 11 December, peaking in intensity the following day. After passing through northern Madagascar, Chido briefly weakened but quickly regained intensity, before making its second landfall near Bandraboua, Mayotte on 14 December, before slightly weakening again later that day and making a third landfall near Pemba, Mozambique the following day; Chido made all three of its landfalls as a Category 4-equivalent intense tropical cyclone. Chido killed at least 89 people; 45 in Mozambique, 31 in Mayotte and 13 in Malawi, along with over 2,200 injuries. Mayotte in particular experienced catastrophic damage from Chido, with thousands of residents unaccounted for, most shanty towns completely destroyed and 85% of the island being left without power by 16 December. In Mozambique, 36,300 homes were badly affected and entire communities were destroyed, and nearly all structures in Agaléga were decimated by the cyclone. Relatively minor damage also occurred in the Comoros and Madagascar. (Source: Cyclone Chido Wiki) While initial mapping activities were focused on Madagascar, they later shifted to Mozambique and Mayotte (officially the Department of Mayotte, French territory) once it became clear that Chido particularly impacted the latter two. | ||||||||||||||
2024 Cyclone Chido
Contacts
- Coordination: Wilson Munyaradzi - Wilson.Munyaradzi@hotosm.org
- Support: Sam Colchester - sam.colchester@hotosm.org
- Support: Geoffrey Kateregga - geoffrey.kateregga@hotosm.org
Hashtag
All contributions are tracked with a unique change set comment tag: #chido
ohsomeNow Stats page for tracking overall contributions
Timeline
- Start: 12 Dec 2024
- End: Likely mid/end January 2025
Map and Data Services
Exporting OpenStreetMap data
- Search for country name and filter by HOT here: HDX
About This Disaster Activation
About HOT
To learn more about the Humanitarian OpenStreetMap Team (HOT), explore more of our wiki-pages (root: HOT) or our website hotosm.org. HOT is a global community, mostly of volunteers, and it is a US registered nonprofit able to contract with organizations (email info at hotosm.org to contact our staff), we are also a 501(c)(3) charitable organization.
History of this Activation
- 12 Dec 2024: Size up completed by Wilson Munyaradzi
- 12 Dec 2024: MapSwipe project for northern tip of Madagascar created in close collaboration with OSM Madagascar to detect built-up areas for rapid building digitization in anticipation of Cyclone affecting north
- 13 Dec 2024: Madagascar MapSwipe project completed in under 20 hours, but outputs not used for this response because fortuntely the Cyclone passed further to north than anticipated and only minor damage, mild flooding and power outages were reported
- 15 Dec 2024: 57 hour outage on OSM server started, during which no contributions could be made to OSM
- 17 Dec 2024: Outage on OSM server ended at 13:30 UTC
- 18 Dec 2024: HOT made contact with OSM France community
- 19 Dec 2024: After OSM France community member shared priorities in Mayotte, first HOT Tasking Manager project published and wider OSM community notified
Data Quality
Validation
Validation permissions for Tasking Manager projects are restricted to particular Tasking Manager Teams / users to ensure high quality validation:
- HOT Global Validators
- Validator Trainees
- MSF Validators
- Data Quality Interns
- Data Quality Interns 2022
OSMCha
A OSMCha can be used to detect data quality issues across a wider area.
For Mappers
How You Can Contribute
MapSwipe
Go to https://web.mapswipe.org/#/en and look for a Chido project. This is a very easy way to contribute, but please follow the tutorial if you have not used MapSwipe before.
Learn to Map
- Most of our volunteer needs are for remote OSM contributors, visit LearnOSM.org to get started.
Mapping Priority
- Please choose from highest priority first.
- We call for local mappers to prioritize local knowledge on the area.
HOT Tasking Manager
All HOT Tasking Manager projects and their progress can be seen here. For any projects that are marked 'Published', select the link in the Project ID column and it will launch the project and you will be able to contribute.
Mapping Instructions
For Mayotte
Imagery
Please use Custom imagery for this project, it is high resolution imagery (20cm) 'BDOrtho IGN' captured in 2023. It is provided by IGN, the national mapping institute for France.
Please align the imagery with existing features. See iD Editor Imagery Adjustment for this. Don't hesitate to subdivide cells if there are too many buildings.
Instructions for mapping buildings
The imagery needs to be aligned with existing features before starting mapping!
Mayotte is very well mapped in OpenStreetMap. But there are gaps because the imagery is new and there are fast developing urban areas in Mayotte.
After aligning the imagery to the existing features, please start mapping first any unmapped buildings. In order to identify already mapped buildings please zoom into your task and carefully examine the existing content. Try not to re-draw already existing buildings!
Many buildings in Mayotte are in informal settlements / slums and these have been particularly badly affected by the cyclone, they are also the most likely areas to need mapping because these slums change and develop quickly. Please pay extra close attention to those areas.
After drawing the outline, use the 'q' key in the iD editor / JOSM to "square" the corners.
For circular buildings (if any) there is the 'o' key in the iD editor / JOSM to create a circular structures.
Many buildings are very close but do not actually touch each other. Try to map them as close to each other as possible without letting them connect or share nodes with each other or with roads. In the iD web editor, holding down the "alt" key will keep nodes from "snapping" to each other and accidentally connecting.
In the iD web editor, the first time you map a building you will use the "Building Features" category and then at the top of the list select "Building" again. This is the most generic building tag we can use as we almost never can tell the more specific use of any building from imagery alone.
For Mozambique
TBC