Context and objectives
The Moroccan government is planning the extension of the harbour of Mohammedia (1993). Conscious of the possible problems this industrial development might create for the neighbouring inhabitants, the government decided to call for an environmental impact assessment to be executed by a foreign consultancy firm, in order to analyse the economic activities and environmental aspects of the area.
Various applications demand a knowledge of the population number as well as an analysis of the population distribution. Data on population distribution do not exist because the results of demographic surveys are aggregated by sector. It is also important to have access to recent data since the area is characterised by a rapid population growth.
Expected scientific results
A quite accurate land use map of Mohammedia and surroundings was produced, and the number of inhabitants and the population distribution (population densities by residential zone) were estimated. The resulting estimated population numbers differ substantially from the official population data (underestimation by the official authorities and development of recent residential areas on the one hand, empty houses and second residences in the seaside resort on the other hand). The estimation result should be interpreted as a ‘potential population capacity’.
For urban applications, the use of SPOT XS imagery is best complemented by data from other information sources, because much urban information is lost due to the ‘relatively’ low level of detail of the images. The proposed methodology provides up-to-date, objective and reliable information in a short period of time (within 2 months), and is independent of permission from local administrations.
Possible problems characterising this type of study : administrative delays, resulting in a restricted or non-existing logistic support in the field, delay in receiving the authorisation for the aerial survey, lack of a recent SPOT XS scene of good quality, …