Open Cities



Saint-Louis, Senegal

Saint-Louis city is located in the coastal zone at the mouth of the Senegal River. The historic city, registered as a World Heritage Site by UNESCO in 2000, is exposed to multiple natural hazards, including floods (inundation from both the sea and Senegal River), coastal erosion, and saltwater intrusion. Climate change impacts such as sea level rise (SLR) and increased frequency and intensity of storm surges and gale force winds are exacerbating vulnerability to these hazards. Home to just under 300,000 inhabitants, the city is separated into three geographical areas linked together by the Faidherbe Bridge: the thin Langue de Barbarie peninsula on the western coast; the old town on N’Dar Island on the Senegal River; and the mainland, Sor, on the river’s eastern bank. Informal settlements are spread throughout the greater city, making up 30 percent of the urban space. Human induced impacts are also acting to increase the city’s vulnerability, including, i) high population growth; ii) ecosystem degradation; iii) insufficient urban stormwater management; iv) deficiencies in urban waste management and sanitation infrastructure and services; and v) poor planning and management resulting in increasing informal settlements and encroachment into fragile and flood-prone areas.
The Open Cities Saint-Louis project complements ongoing World Bank project activities in the city, such as: the Climate Change Adaptation Project (PROGEP), the Saint-Louis Emergency Recovery Project (SERP) and the West African Coastal Areas (WACA) project. It is also directly supported by City Coastal Resilience in Africa (CityCORE Africa), a World Bank technical assistance project enabling coastal resilience policies and investments in selected coastal cities of sub-Saharan Africa. Exposure data for Saint-Louis are outdated and incomplete, therefore the Open Cities Saint-Louis project will collect attributes related to buildings, drainage and roads in all neighborhoods of the city. The City Planning and Development Office (ADC) and Senegal’s urban departments (DUA and DRUH) will serve as the Open Cities project’s primary government counterpart for the city. Improving these databases will be a critical element to support effective data-driven urban planning and increase urban resilience.

Mapping Progress to Date

This section provides an overview of mapping activities in the selected city geographic extent. The Before/After widget below allows comparing current density and distribution of map features with snapshots from previous years. The time chart of OSM editing activity over time offers insights on how many features have been contributed to the map over a specified period.

Data Quality

While OSM coverage keeps increasing, it's important to also understand quality of the data created. The tools available in this section allow for comparing OSM data with other "reference" datasets. These could be, for example, official datasets from government agencies showing distribution of features with those available OSM. The "Gap Detection" widget provides a visual representation of potential gaps in data, by comparing the latest OSM buildings with built-up areas automatically detected from satellite imagery.

OSM Community Dynamics

Understanding mapping progress and data quality also requires looking at the local OSM community and how mappers have contributed over time. Embedded widgets in this sections allow e.g. exploring the list of top mappers who contributed to features within the city extent, with links to their OSM user profile page. A time chart of number of user contributions over pre-defined time periods (daily, weekly, monthly), also provides a picture of how consistent the mapping activity in the area is.

Date Range

users made contributions