Open Cities

Antananarivo

Madagascar

Antananarivo, Madagascar

Antananarivo is located in the heart of the highlands of Madagascar; situated on twelve laterite hills and alluvial plains drained by three rivers (Ikopa, Sisoany and Mamba). The region receives an average annual rainfall of 1300mm, of which 90 percent is concentrated in the rainy season. Antananarivo faces challenges with urban and riverine flooding, which are further complicated by ongoing issues of rapid urbanization; lack of land-use planning; informal housing; drainage and waste management; and degradation and loss of green space.
The Open Cities Africa Antananarivo project will focus on low-income formal and informal areas are the center of the city. These areas are prone to significant flood risk and face extremely high levels of poverty. The World Bank is currently preparing a series of projects in this area, which includes activities on drainage, flood protection and urban upgrading. The proposed activities will support the implementation of this investment project, and the development of follow-up projects. The products that are needed in the short term include spatial open-access datasets on housing, infrastructure and green space, to inform engagement and investment on the ground. This open data will be used to explore changes over time to better understand the urbanization process. In the longer term it could be beneficial to develop a web platform (e.g. GeoNode) to share and use geospatial information.

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