Table of Contents
What is Cartography?
Cartography is a technique that is primary concerned with the reduction of the spatial characteristic of a large area- a portion or all of the earth or another celestial body and putting it in a form that makes it observable. Just the way spoken and written language allows people to communicate beyond the restriction of having to point to everything, a map also allows us to extend the normal range of vision , so to speak and makes it possible for us to see the larger spatial relations that exist over large areas. A drawn geography map is more than a mere reduction if it is well made, it is a carefully designed instrument for reducing, calculating, displaying, analysing and in general understanding the interaction of things in their spatial relationship. Nevertheless, its most fundamental function is to bring things into view.
Cartography is defined as the art and science of making maps, which illustrate data in a spatial form and are invaluable in understanding what is going on at a given place at a given time. According to multilingual dictionary, cartography is defined as the art, science and technology of making maps, together with their study as scientific documents and works of art. In this context, maps may be regarded as including all types of maps, plans, charts, and sections, three-dimensional models and globes representing the Earth or any other celestial body at any scale.
Maps range in size from the tiny portrayals that appear on some postage stamps to the enormous wall maps used by civilian and military security groups to keep track of events and forces. They all have one thing in common which is: to add to the geographical understanding of the viewer. It is important to realize, however, that all maps have the same basic objective of serving as an interpretation of the geography setting, however, dissimilar the map may seem, the cartographic methods involved are fundamentally alike.
Making maps and verifying a location have become more exact with the development of the global positioning system (GPS). A GPS unit can collect signals from orbiting satellites and calculate an exact location usinglatitude andlongitude, which is helpful for showing where one is located on the earth or for verifying a point on a map.
The traditional close association between geography and maps is appropriate given the disciplines concern with space and place. The symbiotic link between geographers and maps has assured the persistence of cartography as a sub-discipline of geography within most academic settings.
The field cartography has changed enormously during the past four decades, primarily because of the widespread availability of computers. Computers have made for new symbolization, such as dynamic (that is, animated) maps, customized maps for individual users and interactive maps. They have also made possible new methods for scientific visualization and spatial data analysis.
According to McMaster and Shea, 1992, geographic cartographers have made especially valuable contributions to the development of automated mapping systems. Their research on map reading processes, map production techniques, cartographic generalization, and cartographic design has facilitated the automation and formalization of what had been an intuitive manual procedure. With generalization, for example, a conceptual model has been devised that separates the objective an holistic approaches of traditional cartography into discrete subcomponents that have been successfully incorporated into digital mapping software.
Cartography is seen as a communication system- In order to transmit and record useful information, humans have developed several methods and the skills necessary to employ them. One method is the use of written language and the ability to deal with what we call literacy. Another is the employment of spoken language and the ability which is called articulacy. Still another has to do with the use of numbers and he corresponding skill has been called numeracy. Equally important is communication through graphic devices; the skill of doing this is called graphicacy.
Graphicacy consists of variety of techniques ranging from photographs to drawn picture, graphs and diagrams. All graphics have one thing in common that distinguishes graphicacy from the other communication skills: the employments of the two dimensions of space to represent concepts and ideas. Spatial relations can be symbolized with words or numbers but that is quite inefficient as recognized by the maxim. A picture is worth a thousand words the map employs the two dimensions of geographical space in a systemic fashion and this puts the skill of mapmaking and map reading in the graphical category. In cartographic communication system, the real world is the source, the encoding is the symbolism of the map, and the signal is the two-dimensional graphic pattern created by the symbols; the signal consist of the light rays transmitted through the channel space to the decoder which is the eye-mind.
History of Cartography
The history of map making is often considered to be older than history itself, that is, if we take history as beginning with written records. The drawing of maps on skins, woods, stones surely antedates the art of writing. The ancient people living as hunters and warriors had to move about a great deal. They needed the knowledge of directions and distances and they therefore developed some system of map making and the production of charts. For example, the Marshall Islander produced very interesting primitive charts. The charts consisted of shells attached to a framework made of the midribs of palm leaves. The straight network represented the open sea: the curved lines were to represent the waves as their fronts approached the islands were shown by shells.
The oldest known map is the clay (2500BC), which was discovered in the ruined city of Ga-Sur, about 300km north of Babylon. It is now on exhibition in the Semitic Museum of Harvard university. The map comprises of a baked clay tablet showing a river, probably the Euphrates, mountains, shown in fish scale on either side. The river was shown flowing through a three-lobed delta into a large body of water (a lake or seas). The direction of north, east and west were shown with inscribed circles. This indicates that maps were aligned in the cardinal directions at that time as we now do.
Land surveying which leads to the production of maps known to have undoubtedly began in the great organized empire of the Nile Valley and Delta. The surveying and mapping of the land were principally for the purposes of taxation. The land was carefully measured and boundaries marked. It was Ramses11 (13333-1300BC) who initiated the systematic land survey of the whole Egyptians empire. The results were often recorded on maps. Eratosthenes, the Greek scientist later made use of these early Egyptian maps.
Our present day maps are better and much more sophisticated than at any time in history. This is because over the countries, there has been mapping and re-mapping thereby improving on their standards. We now know our earth so well that we confidently expect maps of any part of the earth to give us the same picture no matter what agency produced it. This was not so in the past, for example, the 16th century maps of the world differed significantly one from another, and even before the 16th century when it was philosophy rather than empirical facts that had to fill the enormous gaps in the world knowledge, an even greater diversity was found. At that time, Christians, Chinese, Greeks, Romans and Arabian each envisaged the whole world in their own particular way.
Scope of Cartography
In the past, the term cartography referred only to the art of map making. Even so the terms were quite inclusive, often encompassing the survey operations preparing the map. Since the mid-twentieth century, the scope of the field has been greatly enlarged to include the study of maps as documents. In the broad sense, cartography now includes any activity in which the preparation and use of maps is a matter of basic interest. These includes teaching the skill of map use, studying the history of cartography, maintain map collections and the associated plans and often requires particular training, they deal with maps and it is the special character of the map as the central unique intellectual object that unites those who work for them. All maps are reduced (scale) representations of the earth or other celestial body, prepared according to a geometric plan with generalized symbolic representations of reality. Although two maps may be very different, they will have more in common with each other than with any other form of monographic communication.
Cartography has developed a distinct body of theory and practice that includes a series of processes that are peculiarly cartographic and common to the making of all maps. To separate the field of cartography into divisions is as difficult as trying to classify the various kinds of maps.
Cartography is usually thought to consist of two classes of operations. One is concerned with the preparation of a variety of general maps for basic reference and operational purposes. This category includes, for examples, large-scale topographic maps of the land, hydrographic chart, and aeronautical chart. The other division has to do with the preparation of an even large variety of maps to accompany the written text in books and planning maps. Within each category, there is also considerable specialization such as may occur among the survey, design, drafting and reproduction phases of a topographic map. All such divisions and activities blend one another, however, and sharp compartmentalization rarely occurs. The first mention category works primarily from data obtained by field or hydrographic survey or by satellite and photogrammetric methods. For instance, the shape of the earth, height of sea level, land elevation, precise distances, and photogrammetric instruments and remote sensing are an integral part of this sort of cartography. Generally, this group includes the great national survey organisations, the oceanographic and aeronautical charting agencies.
Other category which includes thematic cartography draws on the work of the first group but is mostly concerned with the communication of general information and with the effective graphic delineation of relationships, generalizations and geographical concepts. The specific subject matter may be drawn from history, economic, urban planning, rural sociology, engineering and many other areas of the physical and social sciences, hence, there is no limit.
The major conceptual-operational divisions of the field outlined above do not take into account some other fundamental areas of cartographic activity that , in the United State, tend to cut across the large-scale, compilation-oriented groups. There are several of such areas: private mapmaking companies, commercial survey and mapping companies, planning agencies, and cartographic information departments. Commercial cartography is made up of a large number of companies from small, local organizations to large, complex organizations with national and international markets in the United States, there are more than 100 of such firms and they employ over 100 cartographers: the majority of them are technicians, and the rest of them are compliers, editors, and researchers the products of such companies are very diverse, ranging from street and planned maps to specialize at least and road maps. The maps are either prepared by the consumers, such as a street plan for a town or they are compiled research staff in major map making companies or in cartographic department of publishing companies or encyclopaedia publishers. Cartographers employed by planning agencies often work with air photography.
Because cartographers have much in common with geographers, surveys and photogrammetrists, some societies include these interests. For example in the United State, the American Congress on Surveying and Mapping (ACSM) encompasses surveyor as well as cartographers.
Importance of Cartography
- Cartography allows people to work with styles and symbols to represent objects on a piece of paper, The most important thing about the use of symbols is the provision of appropriate interpretations key at the margin of the map for the map user to know what each symbol represent on the map.
- Maps and other cartographic features are generally attractive to man, a lot of people like to use maps; to locate things and important place on the surface of the earth, while some just love to view for the beauty of it. Recently, there is an high increase in the number of users and use of maps around the world.
- Cartography makes it possible for true representation of the region in a short scale, that is, it makes it easy for users to represent a particular area on a very small piece of paper.
- Cartography has made it easier to maintain maps and update them much faster especially when it comes to digital maps.
- From the earliest time till now, map making has been an on-going exercise. Map is a useful tool that allows man to interact and understand his environment. Maps have been, and are still produced for use in decision making in several areas, the major ones being socio-economic, security defense and environmental management.
- Cartography has made it is easy to symbolize data on a piece of paper to make sense in a real world environment. This makes it easier to represent any data or information within limited space and time.
The Functions of Cartographers
- All maps are reductions- this means that the first decision of the cartographer must have to do with the dimensional relationship between reality and the map; this is called scale. The choice of scale is of primary importance because it sets a limit on the information that can be included in the map and on degree of reality with which information can be included or delineated.
- Another of the cartographers distinctive task is to employ a transformation of the spherical surface that changes into a plane. Such a radical transformation introduces some unavoidable changes in directions, distances, areas, and shapes from the way they are on the spherical surface. A system of the transformation from the spherical to the plane surface is called map projection, and the choice of a projection must be made for every map.
- The third task of cartographers is to generalize; they must simplify where necessary and plan to make either more or less graphically prominent ( according to purpose) the categories of data that they intend to include. Generalization is one of the most difficult task for cartographers. If cartographers are to represent a coastline at a s reduced scale, they must know the characteristics of that coastline or at least of its type similarly, if they are to generalize a river, they must know whether it is a dry land or a humid-land stream, something of its meanderings, volume and other important factors that might make it distinctive form or in character with others to be shown.
- The fourth major task of the cartographer is to design the graphic characteristics of the map. The map must be legible, the symbolic or notation must be suited to the objective of the map and the whole must be fitted together to make an efficient graphic display. The preparation of the graphic communication must be planned carefully so that the receiver will be able to obtain efficiently the information being conveyed. This face of the cartographic method involves a variety of operations: deciding on the methods of portrayals, choosing lettering sizes and styles, specifying widths of lines, selecting colours and shadings or patterning, arranging various elements within the map and creating a legend (key).
- The fifth major aspect of cartographic method is the actual construction or drawing of the map and is reproduction. Formally, one simply drew a map with pen and ink and then sent it out for duplication by printer. During the past several decades, a major revolution has occurred in this phase of cartography. The development of scribing, peel coat materials, film manipulation methods and other processes such as computer simulations have made the two aspects of mapping: map construction and reproduction that it is impossible to think of them separately anymore.