The moroccan experience in the census cartography and the gis
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THE MOROCCAN EXPERIENCE IN THE CENSUS CARTOGRAPHY AND THE GIS. Introduction Cartography Objectives Methodology Urban Rural Difficulties GIS Objectives Setting up Achievements Difficulties Conclusion. Introduction.

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The moroccan experience in the census cartography and the gis l.jpg

  • Introduction

  • Cartography

    • Objectives

    • Methodology

      • Urban

      • Rural

    • Difficulties

  • GIS

    • Objectives

    • Setting up

    • Achievements

    • Difficulties

  • Conclusion


Introduction l.jpg

  • The Population and Housing General Census (PHGC) involves extensive financial, human, material, and technical resources.

  • It requires, among others, a previous cartographic work that consists mainly in:

    • collecting adequate cartographic mediums permitting to assure the exhaustiveness of the census;

    • constituting the different geographical entities of the census (districts, zones of control, zones of supervision);

    • gathering the necessary statistical information to plan and execute all the censusphases;

    • setting a coding system facilitating the processing of the data collected through the census.

  • For the censuses previous to 2004, this statistical cartography was essentially a tool to produce plans permitting to appropriately achieve the works of data collection.


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  • The last decades technological progress in geographical information digitalization revolutionized the cartography and allowed it to serve the works of data collection, processing, analysis and the dissemination of the results.

  • In this presentation, we attempt to relate the Moroccan experience concerning:

    • The objectives, the methodology, and the problems and difficulties met during the census cartographic process phases.

    • The setting up of the Geographical Information System: Objectives, implementation, achievements and difficulties.


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  • The cartography has always been associated with the operations aiming at the country population counts. It consists indeed in providing the staff with necessary elements to carry out the data collection works.

  • It is thus of fundamental importance for the censuses since it assures one of the latter’s universal basic principles: exhaustiveness.

  • In Morocco, the methodology adopted in the setting of the statistical cartography takes in consideration the differences that exist between the two residence surroundings.


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  • In urban area, this methodology didn't witness major modifications across the censuses. Based essentially on the actualization of the restitution plans of the cities, this approach has always been considered efficient to appropriately fulfill the census needs in reliable cartographic documentation.

  • On the other hand, the natural specificities of the rural area, as well as the lack of recent and reliable cartographic materials, generally influenced the recommended approach for the statistical cartography in the rural area.


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  • Provide coverage of the national territory with recent, reliable and exhaustive maps for the cities, as well as for the farming areas.

  • Conduct the partition of the entire national territory in geographical zones (census districts) permitting to ensure the exhaustiveness of the census.

  • Endow data collection teams (supervisors, controllers and surveyors) with cartographic documents assuring easy localization of the different observation units at the time of census execution (households, constructions, lodgings, professional use locals, etc.).

  • Collect geographical information required to put in place the adequate organizational device and to assess the human and material means in order to succeed all the census stages.

  • Build a ground sampling basis permitting to set up the inter-census program of households and population surveys on reliable data.


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Urban area cartography

  • The cartography conceived for the cities and urban centers kept a large constancy in the methodological content recommended for all censuses achieved since the country independence.

  • It is based on the method of islets, and consists in achieving the main following tasks, prior to each census operation :


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Urban area cartography

  • Update the available cartographic funds of the urban communes for the whole territory.

    This is based on the previous census maps, completed by plans collected from different departments that are producing maps (restitution plans, physical planning, housing plans, etc.), notably for the peripheries and the extension zones of the cities. The scale of these cartographic mediums generally varies between 1 over 2000 and 1 over 5000.


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Urban area cartography

This activity consists in:

  • Noticing and reporting on these funds the shapes and the geographical positions of the islets and their components: constructions, lodgings, professional premises, etc.

  • Transcribing, on these maps, useful elements for addresses system to facilitate the localization of observation units, at the time of the census and the sampling surveys. This concerns the names of streets, avenues, facilities (schools, colleges, high schools, clinics, hospitals, hotels, etc.).


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Urban area cartography

  • Partition the territory of cities and urban centers into census districts, on the updated map funds. A district is a well delimited geographical zone including a number of households to be counted by a census taker during legally fixed census data collection time. The sectors of control and the zones of supervision are then defined from the districts, as basic geographical units.


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Approaches proposed for the farming areas underwent important innovations aiming to improve the quality of the cartographic documents.

For the earlier censuses (after the independence: 1960, 1971 and 1982), the approach combined the topographic maps, permitting to materialize and to set up the communes boundaries, and the lists of the farming localities: douars (villages) and sub-douars.

The census districts are constituted in this case by a set of douars according to size criteria, in terms of households and especially of minimum distances to browse.


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Rural area cartography

  • For the census of 1994, a great effort has been carried out by conducting the area partition of all the national farming territory, in the same way as in the cities and urban centers.

  • The farming districts are defined thus as being the parts of the communes, having clear boundaries and an average number of households likely to be counted by one census taker during the census execution time.


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Rural area cartography

  • The methodology recommended for the cartographic partition in farming area takes notably into account the specificities relating to relief difficulties and the typology of the douars.

  • The latter are characterized either by their “explosion” or by the scattering of their lodgings through generally large and uneasily accessible territories.

  • The douars constituted in grouped agglomerations represent only the third of the total douars at the national level.


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Rural area cartography

  • For each commune, the partition in census districts is made on the basis of topographic maps on the scale of 1 over 50.000. These mediums give a detailed and accurate representation of the reported natural elements of the territory (roads, buildings, railroad tracks, transportation and electric energy lines, lakes, rivers, relief, etc.).

  • However, we do not have thorough cartographic mediums for the farming localities (douars). In these cases, the cartographers are called on to prepare maps giving roughly the structures of habitat, construction and road network for the high seized douars.


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Main difficulties met

  • Insufficient cartographic coverage:

    On the occasion of each passage of the cartographers (before every census operation), the cartographic teams seek cartographic funds permitting to appropriately update the statistical cartography.

    To this end, the main departments and organisms from which we seek maps are: the Land-registry National Agency “Agence Nationale du Cadastre, de la Cartographie et de la Conservation Foncière”, the Urban Agencies, the Provinces and Prefectures technical services, the Urbanism and Regional Development Department.


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Main difficulties met

The outcome is not always conclusive, either because the collected maps were old or because of lack of coverage, notably in the cities peripheries. In these cases, the cartographic staff is constrained to set up maps by using the steps method.

  • Frequent changes in the borders of the communes

    The limits between the communes are among the difficulties that hinder the cartographic work good progress. These are not defined by any cadastral plan and are subject to frequent changes because of new administrative partitions.


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Main difficulties met

  • Incomplete system of addresses

    Inexistent in farming areas, the system of addresses adopted in the cities and urban centers show important gaps, especially in the peripheral districts. To make up for this difficulty, we try to gather, during the cartographic work, a maximum of information to help better localizing the observation units (names of households heads, names of the basis facilities, etc.). In farming areas, the contribution of local authority representatives provide important support to surveys interviewers and census takers at the data collection time.


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Main difficulties met

  • The programming of the censuses

    The programming of the field cartographic works is set up according to the date planned for the population census execution. Any postpone of this date is likely to influence the quality of the maps prepared for the census. Updating tasks, caused by such rescheduling, often require important time and means mobilization.

  • incompatibility of the douars “villages” with land partitioning

    The “douar” is more an ethnic than a geographical concept. It is not always compatible with the principles of the adopted partition approach.


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Main difficulties met

  • Appeal to insufficiently skilled staff for the cartography

    The important mass of activities, generally required by the statistical cartography, and the buffer delays to respect for a guaranteed quality of the cartographic documents, require the mobilization of human means exceeding the potential of the department in charge of the census.

    This makes it necessary to resort to less than suitably skilled staff (in cartography training and qualifications).


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The Geographical Information System

The geographical information occupies a growing place in the national statistical information systems. It includes two main components:

  • The map: conventional space representation;

  • The territory indexed statistical data.

    The technological progress permitted to bind these two components through the setting up of geographical information systems (GIS).

  • GIS include software and computer procedures conceived to enter, process, analyze and present data with spatial reference in link with their geographical localization.

  • They allow enriching the analysis and diffusion of statistical data and the publication of thematic maps.


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The Geographical Information System

Aware of its contribution, and having all necessary elements for its development (maps, statistical databases), the Moroccan Statistics Directory undertook, since 1997, the process of setting up the geographical information system.


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The objectives of the GIS of the Statistics Directory are mainly:

  • to produce, for the censuses and the surveys, the maps and up-to-date geographical data, of good quality in terms of reliability and precision, and with savings in terms of costs and delays;

  • to integrate the spatialized data of the different statistical databases, facilitating the follow-up of the demographic, socioeconomic and environmental evolution of the different territorial entities;


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  • to provide a modern analysis tool for the presentation and dissemination of the statistical information, illustrating the phenomena that it describes on the corresponding cartographic medium;

  • to provide new solutions for the development and management of the sampling bases and the drawing of the samples for the surveys purpose;

  • to present a conceptual framework of management, organization and follow-up of the fieldworks of different statistical operations.


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Setting up

  • Throughout its activities (censuses, surveys, collection of administrative statistics), the Statistics Directory generates some databases relating to several themes: demography, economy, social, environment, etc.

    These data can be processed and analyzed on cartographic mediums allowing the visualization of the information for each geographical entity (region, province, circle, township, district, etc.).

  • The digitalization of the cartographic mediums was the first work undertook in the process of setting up the GIS, and consisted in recording the maps of the different division levels as digital cartographic files including the real geographical coordinates.


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Setting up

Plotting of the coordinates

  • The cartographic medium used to constitute the GIS digital cartographic basis, which is the one of the 1994 census, does not include any geographical coordinates; hence causing georeferencing difficulties. That is why the first task to achieve was to endow this medium with geographical coordinates.

  • In urban areas, the superposition of the 1994 census cartographic mediums, and the plans of restitution or cities plans, permitted to put the geographical coordinates (X,Y) of at least three distinct points, by board, and that correspond to real reference marks.

  • In farming areas, this operation consisted in reporting the limits of the different geographical entities on topographic papers.


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Setting up

The geographical data entry: The geographical data entry was realized by the following processes:

  • Scanning : transforming the analogical cartographic mediums in raster files, using AO format scanners.

  • Digitalization : transforming the analogical cartographic mediums in vector files, using digitizing tables.

  • Keyboard Data entry, notably with regard to the toponymy and the symbols of the geographical reference marks.

    Georeferencing of the raster data

    It consists in transforming raster data, entered notably by scanner into data of vector type in the Lambert cartographic projection system.


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Setting up

Conception of the geographical database

The previous stages have been achieved in an environment that includes a software of automated drawing engineering (Computer Aided Design) combined with a computer application that assures the link with the databases.

For the ambitions of the Statistics Directory in spatial analysis, it has been judged appropriate to conceive a system that includes, in a same basis, the geometry as well as inherent data. The conception of such a geographical basis is structured as layers of information (points, lines or polygons).


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Setting up

Each of these layers corresponds to an administrative entity (region, province, and township) or statistical (districts, sectors of control, segments, douars, etc).

This operation requires the transfer of data from the CAD files and their structuring according to the layers composing the geographical database.

Data transfer

  • Data transfer process, started after the realization of the 2004 census, adopts a methodological approach which respects the geographical database structure and retrace a priority order in the migration of information layers.


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Setting up

Some layers are already transferred, controlled and cleaned:

  • Layer of the regions representing the administrative limits of the 16 regions;

  • Layer of the provinces :62 provinces and Prefectures;

  • Layer of the communes: 1.532 urban and rural communes;

  • Layer of the urban centers: 157 centers;

  • Layer of the census districts; 37.000 districts;

  • Layer of the sectors of control: geographical zones composed from 3 to 4 census districts;


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Setting up

Other data layers arenow under transfer and integration in the database:

  • Layer of the segments which are parts of farming districts (infra district);

  • Layer of the douars represented as points illustrating the positioning of the farming localities.


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Since its setting up, the GIS has enabled the Statistics Directory to:

  • Elaborate the requested digital maps to realize the Economic Census of 2001 and its cartography;

  • Produce and disseminate the population main features in the shape of a socio-demographic Atlas for the censuses of 1994 and 2004;

  • Produce the maps of the districts, sectors and supervision zones, required for the realization of the Population and Housing General Census of 2004;

  • Constitute the ground sampling units for the purpose of the Master Sample;

  • Contribute to update the poverty maps 2004.


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  • Lack of recent and reliable geo-referenced maps, sometimes causing the recourse to incompatible cartographic mediums. This affects data quality, especially the precision of the geographical coordinates and the positioning of the limits of administrative and statistical entities;

  • Difficult access to the digital cartographic files belonging to the specialized departments in cartography and geographical information;

  • Lack of coordination between the different departments that are producing the geographical information;

  • Shortage in skilled human resources for geographical information processing.


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  • Despite the difficulties, and what GIS implementation costs, our Department has benefited from the new maps.

  • They provide an essential control device that guarantees consistency and accuracy of the census.

  • They support data collection and help monitor census execution. Census takers and surveyors can more easily identify their assigned set of households.


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Maps make it easier to present, analyze and disseminate census results. The Statistics Directory has published:

  • Census results, and Socio-demographic atlas,

  • Poverty maps (regional, provincial, communal,…)


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Thematic map : Socio-demographic atlas 2004Population density by province


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Poverty maps

A poverty rate for each commune

(urban and rural)

An estimated “Human Development Index” for each commune;

An estimated “Social Development

Index” for each commune.

These Communal Poverty Rates have been used to select the most needy Communes for the “National Human Development Initiative” initiated in May 2005.


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  • Decentralization through the GIS at the level of the 16 Regional Directories of the HCP. This activity, placed in the forthcoming census preparation, includes:

    • Providing of hardware and software material;

    • Transfer of regional files and databases to Regional Directories (RD);

    • Training of the staff of the RD;

    • Technical assistance for the staff of the RD.


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  • Data conversion for the new environment: Up to now, some layers are transferred: regions, provinces, communes, districts and douars. Other layers transfer is ongoing.

  • Reinforcement of technical and professional capability of the GIS staff through continuous technical knowledge update.

  • Realization of a website permitting to provide users with GIS geographical information online.


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Thank you very much


High Commission of Planning, Morocco.