In major cities in the southern hemisphere risks are often poorly evaluated and underestimated. Their effects are rarely mitigated by government intervention. The coast of Mauritania, along which Nouakchott is built, is one of these vulnerable areas dependent on human initiative for its preservation. To avoid being wiped from the face of the earth, this young city was rapidly compelled to adapt to its hostile and inhospitable environment. Fifty years later, encroaching sand, flooding and pollution are still pressing problems. While much has been written about Nouakchott and the surrounding area, little trace of these writings seems to have been retained by the collective memory. However, the possibility to stay informed of problems and act accordingly is dependent on the capacity to interface analyses of different origins. Two conceptual models were elaborated drawing on personal accounts and geographical data. Their purpose is to favor awareness and allow informed decision-making. They describe the regional environment and permit the evaluation of the possible dangers in a given territory taking into account the region's vulnerability to many unknown hazards. This approach of accumulating and cross-referencing data in various formats and from different dates, most of which was produced with other uses in mind, led to the creation of an operational GIS to facilitate development projects.