The Map2Mitigate project aims to generate basic open mapping data and strengthen community capacities to monitor and address risks associated with the El Niño phenomenon in vulnerable areas of the Metropolitan Region of Salvador (Bahia, Brazil). Through mapathons, technical training, and drone use, the project enables communities to obtain up-to-date data about their territories, facilitating disaster prevention and evidence-based public action.

Context

Northeast Brazil faces serious challenges from intense rainfall and unplanned urbanization, especially in informal settlements located on hillsides and in valleys. Salvador, one of the most populous cities in the country, has over 1.8 million people living in areas with slopes greater than 30%, and around 194,000 in flood-prone zones.

Neighborhoods like Jardim Santo Inácio, Pau da Lima, Engomadeira, and occupations such as Marielle Franco in Simões Filho are examples of territories with high socio-environmental vulnerability. These areas suffer from landslides, waterborne diseases, and a lack of reliable data, which hinders both governmental and community disaster mitigation and response efforts.

Approach

Map2Mitigate applies a collaborative mapathon methodology using tools from the OSM ecosystem to map risk zones based on vulnerability criteria and community mobilization. The areas of Jardim Santo Inácio, Engomadeira, and Pau da Lima were prioritized, with Simões Filho as a backup area.

The project includes:

• Training local volunteers in open mapping and drone usage;

• Collecting imagery on Mapillary and OpenAerialMap;

• Mapping buildings, water bodies, and critical infrastructure using Tasking Manager and StreetComplete;

• Data validation by partner university experts;

• Integration with previous public health and epidemiological surveillance projects such as VIGEDESASTRES.

Outcome and impact

• Detailed mapping of 3 vulnerable areas in the RMS affected by floods and landslides;

• Production of 1 technical report identifying critical urban and natural elements;

• Direct involvement of at least 1 local Civil Defense team;

• Participation of 15 residents per community in data collection;

• Public availability of the data on OpenStreetMap and OpenAerialMap;

• Strengthening of the YouthMappers network in Bahia and alignment with the Periferia Viva Program

Leassons learned

• Collaboration between universities, government, and communities is essential for sustainability;

• Community mapping strengthens disaster response and evidence-based public policy;

• The model will be replicated in other communities in Bahia’s interior with support from the YouthMappers network and VIGEDESASTRES;

• Technical and scientific publications are planned to disseminate results and broaden the project’s impact.