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Transformation of Census Cartography from a conventional paper map system to an integrated Geographical Information Technology based system in African Countries – A private sector perspective with specific reference to Namibia Hennie Loots Director GeoSpace International (Pty) Ltd 1. Introduction Although the use of Geographical Information Technology (GIT) is common in census cartography in more developed countries, it has only emerged in recent years as a viable alternative in a number of African countries. South Africa and Namibia are probably the most advanced in this respect, at least in Sub-Saharan Africa. The aim of this paper is firstly to touch on the role that GIT can play in census cartography in developing countries, specifically Africa. The paper furthermore gives a broad overview of how GIT was used in the pre-enumeration cartographic project for the 2001 census of population and housing in Namibia. Lastly, the paper provides perspectives and highlights issues that need to be taken into account when GIT is being utilised in census and related projects in developing countries, with specific reference to the role of the private sector. 2. Basic concepts related to census practise A population and housing census can be defined as the total process of collecting, compiling and publishing socio-demographic and housing data pertaining, at a specific time, to all the inhabitants of a country or delimited geographical area broken down to the smallest geographical area. A census consists of three distinct phases, namely the pre-enumeration phase, the enumeration phase and the post-enumeration phase. During the pre-enumeration phase the planning and systems required for a census are being developed, tested and implemented. The cartographic sub-project forms part of the pre-enumeration phase. During the enumeration phase the actual data collection takes place. Data from each household and individual within a country or delimited geographical area is collected. This can either be done through door-tot-door visits or by mail. In developing countries this is usually done through door-to-door visits. During the post-enumeration phase of a census the completed questionnaires are being coded, captured, analysed, reports and other data products are being prepared, and the data is disseminated. 3. Conventional approach to census cartography The purpose of the cartographic (sub-) project of a census is to provide the geographical framework for the enumeration phase. Census cartography therefore deals with the systematic subdivision of a country or study area into a contiguous mosaic of small pieces of land, each big enough in terms of population and area, to be manageable by one enumerator during the enumeration phase. These pieces of land are usually referred to as enumeration areas (EAs) and the process is known as (EA) demarcation. The lowest level of reporting of census results determines the geographical framework of a census. Census demarcation therefore usually adheres to the political and administrative boundaries in a country. The most important deliverable of a cartographic project is a set of detailed enumeration area and supervisor area maps. A supervisor area usually consists of three to five adjacent EAs and is mainly used for management purposes during the enumeration. In order to produce the required maps, a census office would first of all obtain all available base maps from the official mapping authority of its country. The maps include 1:250 000 and 1:50 000 topographical maps; town maps and cadastral maps for the country, as well as any other maps that might be useful for the project. In most African countries the acquisition of maps immediately reveals the single biggest problem facing a census cartographic team: the lack of current maps. Since the size and geographical spread of the population of a country is critical for census preparation work, the lack of detailed current base maps poses an immense challenge to census mapping experts. In Africa, in general, most of the topographical maps are 20 years and older. A significant portion of topographical maps was last updated before 1970, which makes them older than 30 years. The population size of most countries on the continent more than doubled over the last thirty years. This fact, together with massive internal and international migration makes the use of the available topographical maps extremely difficult and undesirable. The same problems also apply to town maps. It can therefore be argued that currency and, to a lesser extent, lack of detail are the biggest problems associated with the maps available for census purposes. The solution has been to make use of sketch maps in cases where no maps are available or in cases where the available maps do not meet the mapping requirements for a census. Census demarcation fieldworkers are trained to sketch enumeration area (EA) boundaries, as well as certain prominent features within an EA. In recent censuses the sketch map methodology had been combined with Global Positioning Systems (GPS) technology where GPS receivers were used to geo-reference the sketch maps. In some instances, depending on the settlement pattern and population density, the 1:50 000 or even 1:250 000 topographical maps remained the only useable maps for census demarcation and therefore had to be used. In urban areas available maps were also enhanced / complemented by sketch maps. The mentioned approach was, until recently, the only viable option available to census projects and was hence considered to be the best solution under the circumstances. There is, however, numerous so-called errors of coverage associated with the use of an inferior base map, making census practice in African countries both difficult and inaccurate. Errors of coverage deals with all errors associated with the missing of certain individuals or households, as well as the double counting (or more than double counting) of persons or households in a census. Although most of the errors usually occur during the actual counting process (enumeration phase) a number of significant errors can be directly ascribed to deficiencies in the cartographic base of a census. Since there is often little or no available information on the size and spread of the population prior to the cartographic fieldwork, it is extremely difficult to plan the work properly. It is also very difficult – if not impossible – to check the work done by field teams without physically revisiting the areas in the field. A census cartographic team thus has to rely on the output from the field without really having any control over the quality and coverage of the work. It is often also very difficult to locate the exact position of administrative political boundaries on the ground. The reason for this being the fact that many of the boundaries were defined by using maps that were already dated at the time the boundaries were changed / proclaimed. The result is that the position of an administrative boundary is often expressed in terms of coordinates and hence they often do not follow features on the ground. This makes it very difficult to locate these boundaries on the ground and hence often leads to demarcation and enumeration coverage errors. Most of the mentioned issues are a direct result of the inherent deficiencies of the conventional methods used for census cartography. It can therefore be argued that, if applied properly, GIT should improve the quality of censuses through, amongst others, better quality maps. 4. GIT approach to census cartography The unique spatial data needs for censuses make a census an ideal candidate for GIT solutions. The key is not to use technology merely for the sake of technology, but to use relevant technology that provides workable solutions. 4.1 The use of GIT in the creation of base map data As already mentioned, most available base map data (hard and soft copy) relevant to censuses in developing countries are dated. A huge demand for base map data thus exists and could be addressed on two distinct levels of detail, namely satellite imagery and high-resolution digital aerial photography. The progress in the field of digital base map data collection and image processing over the last few years has been nothing short of spectacular. Due to the availability of sophisticated image processing software combined with powerful and large capacity computers, both these data sources nowadays provide a sound and viable base map data solution for the building of a GIS. Satellite image analysts can, with modern image processing techniques, determine the size and relative density of all populated areas within a selected country or area of study from satellite data obtained from satellites such as SPOT or Landsat. This data can then be used to determine the exact areas for which high resolution detailed digital aerial photography is required. Detailed base map data generation through the use of modern digital aerial photography systems can then be focussed on the exact areas where required. Modern digital aerial photography systems, such as the Finnish system being utilised by GeoSpace International, provide high-resolution digital colour imagery at a fraction of the cost of conventional aerial photography. It also has the added advantage of an extremely short image processing time compared to conventional aerial photography. 4.2 The use of GIT in census EA demarcation fieldwork The main aim of census demarcation fieldwork is to define EA boundaries. This is normally done after the necessary base map data has been obtained from the relevant sources or created through the most relevant method for a given area. Although there is currently no real substitute for census demarcation fieldwork in the African context, GIT can make the task far more efficient through better control and better management. By having access to more detailed and current base map data, the fieldwork exercise can be better planned and managed. Maps at the required size, level of detail and scale can be generated to optimise fieldwork. The data collected in the field can also be captured in the spatial data base. To minimise coverage errors, fieldwork outputs can furthermore be checked against the external sources of data, such as satellite imagery. Once the data collection at all levels is completed, maps that meet the exact requirements of the different levels of census management, can be generated. 4.3 The use of GIT in map production GIT enables one to produce maps at various sizes, scales and levels of detail for each unique requirement. Over and above the fact that one has the flexibility to produce a map for every situation, you furthermore has the ability to develop map printing applications that enables the production of literally thousands of similar maps using standard map layouts and criteria over a relatively short period of time. 5. Case study: 2001 Census Cartographic Project in Namibia 5.1 Background The Republic of Namibia is one of the youngest democracies in the world. After about thirty years of civil war, the country gained independence from South Africa in 1989. Namibia is situated in south-western Africa and is bordered by South Africa in the south, Botswana and Zimbabwe in the east, Zambia and Angola in the north and the Atlantic Ocean in the west. The country has a population of 1,83 million and a land area of about 1million square kilometres. Namibia relies heavily on the economy of South Africa. The biggest industries are diamonds, fisheries, cattle and tourism. The biggest tourist attractions include the Namib desert and the Etosha national park where the big five can be seen in a well maintained natural environment. The far northern part of the country, where more than 50% of the population of the country resides, provides the tourist with a very interesting view on the traditional way of life in Namibia. The first population and housing census after the country came into being, was conducted in 1991. The second census was conducted last year (2001). During 1999, the Central Bureau of Statistics (CBS) at the National Planning Commission (NPC) – the government institution ultimately responsible for the census in Namibia – started with the cartographic work for the 2001 census. It was decided that the 2001 census should be planned and published with the aid of GIT. 5.2 Project overview The main aim of the 2001 Census Cartographic Project in Namibia was to systematically sub-divide the entire country into EAs and to produce a set of maps to be used during the enumeration phase of the project. The traditional approach for this task was to use a combination of available hard copy maps and sketch maps. The entire system was, as a result of this approach, manual. In 1999 the NPC decided to depart from the traditional approach to census cartographic work and to utilise a GIT-based approach for this important task. Due to limited in-house capacity, Devinso (one of the companies in the GeoSpace International group of companies) was awarded a contract to develop a GIT driven census demarcation methodology and to assist with the implementation and management of the project as a whole. The initial contract was awarded in November 1999 and project duration was just under two years. The project was divided into the following distinct phases or activities:
At the time when the project started (November 1999) no GIS infrastructure existed and very little GIS capacity was available at the NPC. A study was consequently done to determine the existence and availability of spatial data for Namibia. Furthermore, a functional specification based on the unique requirements of the census, was drawn up. Based on the specification, the system (hardware, software and network) was installed in January 2000. 5.2.2. Establishment of a data warehouse Once the system was in place, all the relevant data from the official suppliers of spatial data in Namibia was obtained, converted where required, and incorporated in a spatial data warehouse. 5.2.3. Evaluation of base map data A set of criteria was determined for the census maps in each broad settlement type in Namibia. The data in the system was evaluated against the agreed criteria. The result of this exercise revealed areas in the country where the available base map data did not meet the agreed specifications. 5.2.4. Collection of additional base map data Where the available mapping data did not meet the agreed requirements, additional base map data was collected, mainly through three methods: a mapping program; digital aerial photography and enhancement of available maps. Mapping Roughly 50% of the total population of Namibia resides in the north of the country in two predominantly rural areas with a total of 4,5 million hectares, representing only 4,5% of the total land area of the country. The settlement pattern in those areas is of such a nature that 1:50 000 topographical maps are best suited for census purposes. The available 1:50 000 maps for this part of the country are, however, 30 years and older. This made them virtually useless given the significant changes in size and distribution of the population over the last 30 years. Due to the fact that up to date small-scale (1:80 000) aerial photography was available, it was decided to map the most relevant features such as roads, hydrology, homestead boundaries and housing units. The vector data from the mapping program was superimposed over the raster image 1:50 000 topographical data to provide what is in essence an updated 1:50 000 map with enough detail for census cartographic purposes. Digital aerial photography As a result of the evaluation of existing data, roughly 100 urban areas or larger rural settlements were identified for the digital aerial survey program. GeoSpace International’s sophisticated digital aerial photography system was used for this purpose. The photography mainly covered relatively dense urban or urban type settlements for which no vector data (town maps) existed. Ortho photomaps at a scale of between 1:10 000 and 1:2 500 – depending on the requirements – were generated from the images. Enhancement of available maps Evaluation of existing base map data furthermore revealed that for some urban areas maps would exist but, for example, without any street names or suburb boundaries. A dedicated team of fieldworkers visited these urban areas and either acquired additional data from the relevant local authority or collected the outstanding data in the field. 5.2.5. EA demarcation and NAMPLAN data collection After the establishment of a fairly detailed base map for the entire country, the actual sub-dividing of the country into EAs could begin. This was done through a combination of office- and fieldwork. The outer boundary of each populated area, referred to as a locality, was determined and annotated on the GIS generated fieldwork maps. GPS coordinates were taken to check that the data collected for a given locality was eventually linked to the right polygon (locality) in the spatial data base. During the fieldwork phase, the position of every institution in the country was also recorded. This was necessary since institutions require special enumeration procedures. At the same time a core set of attribute data on the services available to each locality and institution was also captured. Institutions included were medical, educational, police, prisons, government buildings, accommodation and community centres. Data on the following services was captured: water, sanitation, telecommunication, electricity and accessibility. The data on services available to localities and institutions in Namibia, is known as the NAMPLAN data base. Localities were then, depending on the settlement type, grouped together or sub-divided to form Census Enumeration Areas (EAs). In general an EA consisted of 80-120 households. The data collected during demarcation fieldwork was captured in the system through a combination of methods. The spatial data was digitised (heads-up) from the field maps. The attribute data and NAMPLAN data was captured through manual entry as well as through a process where data from data loggers was downloaded directly into the data base. All the data recorded with GPS receivers was downloaded directly into the data base and thereby virtually eliminating data entry errors. Once all the data for a given region was captured, the data was evaluated and upgraded through an iterative process by means of the production of series of maps that were scrutinised and corrected (where necessary) by the census cartographic team. The end product was a detailed data base that was thoroughly verified and eventually signed off by the cartographic team at the Central Bureau of Statistics. 5.2.6. Map production Once the data base was populated and signed off, the base map data together with the census specific data were used to create a set of about 5 150 unique maps for the enumeration phase of the census. These maps were generated from the data base using a specially developed map plotting application. The map creation and the printing of 4 copies of each map were done over a period of roughly four weeks at the end of the pre-enumeration cartographic project. The project was a resounding success. It consequently provided what is arguable the most detailed and accurate mapping data ever available for a population census project in Africa. The map and map related queries received from the field during the enumeration phase of the census were negligible compared to what is usually experienced in countries where the traditional approach to census cartography is followed. Analysis of the Post Enumeration Survey (PES) conducted shortly after the main census in August last year, revealed an estimated undercount of 2,2% for the census. This is, as far as could be established, the lowest undercount rate ever achieved in a census in an African country. Since a census undertaking consists of many interrelated sub-projects, it can be stated that high quality maps alone cannot guarantee a successful census. However, a successful census is impossible in the absence of high quality maps. It can therefore be argued that the superior maps produced for the 2001 census in Namibia by using GIT driven solutions, established the platform for the overall success of the census as a whole. 5.2.7. Project closure The entire project was documented and officially handed over to the National Planning Commission. The final deliverable of the project was the Project Closure Report. 6. Considerations for the usage of GIT in African countries Growth in the GIT industry in developing countries, especially in Africa, has not been nearly as fast as in the more developed countries of the world. There are many reasons for this. The development in the entire IT industry had been led by the first world. In a sense it can be argued that less developed countries first have to cross the technology bridge before GIT will become more widely available and used. The lack of GIT capacity in public as well as the private sector is a huge constraint. Experience has revealed that a number of important considerations should be taken into account in the initiation, implementation and ultimate successful delivery of GIT driven projects in developing countries. Some are discussed below. 6.1 Data Digital spatial data, or rather the lack thereof, is arguably the biggest constraint in the establishment of effective GIS solutions in developing countries. A GIS solution that assumes spatial data is readily available is likely to be doomed, since any GIS is only as good as the data in the system. A key component of most GIT solutions in developing countries, especially with regard to demography, is in actual fact the ability to generate input data (base map data) that would elsewhere in the world be considered simply as “being available”. 6.2 Expectations Client ignorance in the field of GIT is a huge risk for a private sector company trying to promote the use of GIT in public sector driven projects. It often leads to misconceptions of the role GIT can play and hence leads to unrealistic expectations. It is therefore of the utmost importance that private sector companies promoting the use of GIT should spend a considerable amount of effort and time to educate decision makers. This should enable them to know the pros and cons associated with a given solution. 6.3 Identification and formulation of needs and requirements Due to the relatively low awareness and knowledge levels of many public service officials in the field of GIT in many African countries, a private contractor cannot only rely on the requests or specifications of the client in order to develop solutions. The private sector must have enough in-house understanding of the needs and requirements of the client in order to be able to educate the client on the role and benefits of GIT in the client’s unique environment. It is extremely important to understand the core business and hence the needs of the client in order to initiate appropriate projects and develop solutions that will really make life easier for the client. 6.4 Inability to distinguish between in-house services and private sector services There are certain products and services that are better rendered by a private sector company than by Government. An extreme example is the development of computer hardware and software. It is assumed by most users that software and hardware are acquired from a reputable developer through an authorised supplier, rather than being developed in-house. Aerial photography is also an example of a GIT product that is better delivered by a specialist private sector company. It is unfortunately often the case that this distinction between what is best to be done in-house and what is best to be contracted out in the GIT environment, is not always that clearly defined. As a result, government institutions sometimes embark on initiatives that could be done far better and more cost effectively by specialist private sector companies. This often leads to the industry suffering due to the inability of certain government institutions to deliver on what was really never meant to be their core business. Base map data creation, such as aerial photography and mapping applicable to census cartographic applications, is an example of a product / service that could be better rendered by a specialist private sector company. A need therefore exists to educate the user community on in-house and contractor functions. 6.5 Pace of transformation Once a GIT driven solution for a given project had been adopted, it often implies an extremely swift transition from the old (conventional) way of doing things to the new (GIT driven) approach. This is especially true in projects with non-negotiable deadlines such as census cartographic projects. If managed properly, and if the right level and amount of expertise from a private sector partner is being utilised, successful delivery of a project can be achieved. It is, however, often the case that the momentum gained during the project is being lost shortly after the project. This can partly be ascribed to the fact that, from an organisational perspective, the client was not really prepared for the transition. Hence, the required organisational structure with the aim to serve the organisation during and after the project, was not properly conceived before the project. The result is often insufficient internal capacity to optimally utilise and properly maintain the system. 6.6 Need to opt for a total solution The ability of a private sector company to deliver a total solution is important in the relationship between private and public sector. This is extremely important in most developing countries, since the capacity in most government institutions is often so low that the service provider / contractor must be able to provide an integrated solution. Where inputs or processes from the client are key inputs on the critical path of the contractor, the contractor must ensure that the client’s staff are sufficiently equipped (trained) and managed to deliver their part of the work. The company must also have the necessary expertise and capacity to provide additional “down stream” services, since it is often required. 6.7 Sustainability Another critical issue that requires careful consideration is sustainability. In many cases the establishment of a GIS is the consequence of a methodology adopted for a specific project. Without proper data utilisation as well as data and system maintenance, such a GIS that might be state of the art today might become obsolete in a few year’s time. It is therefore important to develop a GIS strategy that will ensure proper maintenance of the system and utilisation after completion of a given project. If this is not done, momentum will be lost and the relatively high initial investment in infrastructure and data collection could eventually be regarded as fruitless. Where the establishment of a GIS is the consequence of a change in methodology adopted for a specific project, it might be inevitable that the client will have a capacity gap due to the newly adopted technology. It is therefore important for the client to recognise that the relationship with an external GIT partner needs to continue after the project deadline. This should ensure that capacity building can be achieved while the momentum gained during the project is being maintained. 6.8 Budget constraints The lack of adequate financial and other resources is a constraint that makes the field less popular amongst the business community. GIT initiatives are often project driven with little or no resources available afterwards to properly maintain or optimally utilise the system. 6.9 Ignorance Ignorance amongst many senior managers in public service and related institutions on the need for GIT often leads to a situation where the technology is not used simply because the decision makers are not aware of it. 6.10 Priorities It is often argued that detailed accurate and timely data (spatial and otherwise) is not really required in Africa due to the need for development being so big that any development initiative is likely to address a need in an area (geographical and sector). It is therefore argued that investments in GIT information solutions can be better used in actual projects than in the optimal planning thereof. 6.11 Duplication of efforts Even though there is a huge need for data, there is ironically often at the same time a huge duplication of effort. One company would gather data and a short while later another company would be commissioned to gather the same data. There are many reasons for this. Some is linked to ignorance and other to the needs of the respective clients. If the specifications of one data collection exercise does not meet the requirements of another project or application, duplication might be the only solution. It could, however, instil negative perceptions if not managed properly. 6.12 Data policy and data standards The lack of properly defined data policies and standards is an area where the private sector together with government and academic institutions should strive to seek solutions as a matter of priority. Very few developing countries have properly defined data standards. The result is huge variations in standards, methods of data collection, meta data etc. making the integration of different data sets a nightmare and sometimes impossible. Data policies covering issues such as copyright and data pricing also need attention. 7. The role of the private sector The private sector has a huge role to play in Africa in the promotion of GIT that will lead to good governance and more informed and transparent decision-making. Some of the actions required are discussed below. 7.1 Educating decision makers in the use and role of GIT as a decision-making tool An informed person can take informed decisions. Although not in general the case, decision makers in a number of African countries have access to a wealth of spatial data that can be used to improve the quality and impact of decisions significantly. It is, however, often the case that these decision makers are not aware of the existence of the data and / or how it can be used as a decision-making tool. The consequence is that GIT still does not play the role it can and should in decision making. It is therefore crucial that decision makers be exposed to this technology in order to sensitise and educate them. More educated decision makers will realise the role of GIT and hence support / stimulate the expansion of the technology in order to meet their needs and requirements. 7.2 Educating senior public service officials on the role of GIT in projects such as census cartography Private sector companies such as GeoSpace International spend a lot of research and development resources on the continuous development of better and more cost-effective solutions to the problems associated with census cartography. Census authorities will never benefit from these solutions if the senior managers in statistical agencies are not properly informed on the applications and benefits associated with GIT driven solutions. Once senior management understands the basic principles of the technology and are convinced of the short and long term advantages of the proposed solutions, more consideration will be given to adopt these modern solutions. 7.3 Training and capacity building of GIT operational staff in government, semi government and private sector institutions Formal and project driven training is an important area where the private sector in collaboration with educational institutions must play an important role. The lack of GIT capacity in all spheres of the society is a serious factor inhibiting the growth of the industry. 7.4 Research and development Developing countries have unique problems requiring unique solutions. Even within certain regions in the world huge discrepancies exist between the needs and requirements and hence require unique solutions. The Southern African Development Community (SADC) is an example of this. There are 15 countries in the SADC region varying from very little GIT capacity to the highest capacity on the continent. Although resource intensive, it is the responsibility of private sector companies to invest in research and development in order to provide relevant, cost-effective and sustainable solutions to the public sector. 7.5 Initiating GIT driven projects and solutions In order to remain competitive, successful companies are continuously developing better services and products at more affordable prices. This is especially true in many African countries where huge amounts of money are being spent on methodologies that are completely outdated and often far more expensive than modern cost-effective technology driven methodologies. A challenge facing such companies in Africa is to effectively market and promote the use of such products and solutions. This is not an easy task, since it implies change resulting in uncertainty that could, in turn, lead to resistance. 7.6 Sharing of expertise / experience Due to the huge need for education and training in GIT in Africa, it is important that mechanisms should be in place to facilitate the sharing of expertise and experience. Although this should be done through formal academic studies it should also be done through mechanisms such as GIS user groups. 8. In conclusion The author and GeoSpace International are committed to continue with the development and provision of tailor made GIT solutions to clients in the field of census cartography. We have an established track record in many African countries. In the business area of census cartography the company has in recent times provided cutting edge GIT solutions in Namibia, South Africa and Tanzania. A thorough understanding of the needs of the client, experience gained over the last decade as well as continuing growth in hardware and software solutions open up new horizons in what must be one of the most stimulating and rewarding industries at present. |
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