Geospatial Solutions Development

Implementation of a priority geospatial database and Web access services for the Government of Senegal

To make geospatial data accessible in order to support decision-making in a sound and sustainable socio-economic development context.

Project Start:
January 2014
Length:
15 months

This project was carried out in partnership with Fujitsu Canada and funded by Natural Resources Canada. It caps off the efforts of the Canadian government, which, since 2009, has been involved in developing and implementing the National Geomatics Plan in Senegal. Thus, Effigis has been mandated to set up a standardized geospatial data distribution and management system to make these data more accessible to the Senegalese population.

Context

For a long time now, mapping data for a country were compiled with a predominant concern for their visual representation (to print maps on paper) rather than on its spatial integrity. Integrating these data, as those for Senegal, in the geographical information system and making them easily accessible was a task that took several steps, based on the characteristics of various data sets. First of all, vector data collections included three scales: 1/1,000 000, 1/200,000 and 1/50,000, and their formats were variable. At times, the data were not georeferenced or were on separate layers using simple vector drawings. Regarding the raster collections, part of the country was covered by a set of images that have already been orthorectified (5 m resolution), and, on the other hand, by raw images. Moreover, the digital elevation models (DEMs) produced for certain cities in the country were denser than the DEMs that covered the entire country (from SRTM) with a resolution of 30 m: we wanted to bring both into a single DEM without losing any details characterizing these cities. The purpose of the project was thus to bring together and reconcile all these data into a coherent database in accordance with the international standards.

Challenges

Standardizing three existing vector data collections and the two raster collections was the first step in this project. To do this, we had to first redefine and adapt the national standards to be in line with the international standards. This required the creation of geographic entity catalogues for each vector collection. Not only did it have to anticipate all geographic entities observed in Senegal for these catalogues, but they must also be made uniform to ensure consistency between scales. We subsequently standardized and then structured the data sets so that they complied with the catalogues. During a second step, a spatial database had to be designed that could store all standardized vector data, ortho-images and digital elevation models. After all this work was completed, it was possible to set up Web services (WFS and WMS) to provide access to all these data. The system was deployed in two different government agencies (ANAT—National Agency of Spatial Planning, and ADIE—State Computer Agency). At the end of the project, the personnel received training so that they can run the Senegalese part of the system.

Solutions

Effigis brought together a team of specialists in international mapping standards, vectorial geomatics editing, image processing, relational databases and Web mapping servers to accomplish the colossal task of standardizing all geospatial data in the country. In more concrete terms, we have prioritized:
  • the use of international standards that are recognized and adapted to the reality of Senegal to harmonize the different data collections and facilitate their use by the largest number of users
  • state-of-the-art technologies, such as ArcGIS from ESRI, Geomatica image processing software from PCI, the PostGIS spatial database management system, Python programming language and ETL (Extract-Transform-Load) FME software from Safe Software
  • the development of automated quality control and validation methods
Once the data have been structured and standardized, they were loaded on the servers to make them available for download and accessible online via Web services.

Results

The results of the project were presented during the National Geomatics Days Conference in Dakar, in March 2015. The priority geospatial database in Senegal containing the standardized data collections was given to the Senegalese agency in charge. In order to promote their accessibility, the Web map produced by Effigis enables anyone to consult geospatial data without having to integrate them into a geographical information system (GIS). The servers were deployed in the ANAT and ADIE government agencies. Several training sessions took place to transfer technology and ensure project sustainability. Click here to see BaseGeo Geospatial Database.

Key takeaways

  • Canadian support project for the National Geomatics Plan in Senegal
  • Standardization of mapping data using international standards
  • Production of the priority geospatial database
  • Web broadcast to have public access to the data
  • Training of Senegalese specialists and technological transfer
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Mathieu Benoit

Senior Director – Earth Observation