UNIVERSITY OF GHANA READERSSelected Readings in Geography

ESSAYS IN COMMEMORATION OF THE 65TH ANNIVERSARY OF THE UNIVERSITY OF GHANAEdited by, GEORGE OWUSU, SAMUEL AGYEI-MENSAH, PAUL W. K. YANKSON, and EMMANUEL M. ATTUASocial Sciences Series Vol. 1, Woeli Publishing Services

CHAPTER 2The Map as a Tool For Explanations in GeographySOSTHENES K. KUFOGBE, ALEX B. OWUSU, GERALD A. B. YIRAN IntroductionGeography studies the locational and spatial variation and interelationships in both physical and human phenomena on earths surface. In undertaking this reality, one is not only concerned with what is where but also why things are there and probably whether they are there as a result of natural happenings or human interventions. Geography also studies the variations over time as well as consequences of the spatial and temporal variations. Thus explanations in geography comprise ways in which geographical understanding and knowledge can be acquired and the standards of rational argument and inferences that are necessary to ensure that this process is reasonable. The map image is a complete symbolic coded transformation of geographical reality. There is, therefore, the need for a comprehensive decoding mechanism comprising conventions in order to achieve the intended comprehension.

Despite the power of maps as explanatory tools, very few scholars outside of geography use maps; some people are intimidated by maps. Michael Peterson, a Professor of Geography and a Cartographer, suggests that maps are not used because people lack the basic skills to read them. He went further to state that even highly educated people have trouble using maps because they lack the basic map competency and concluded that most people are map illiterate. This statement is true particularly in Ghana where maps are only formally introduced to geography students at senior high school level. Others who do courses that use maps, particularly geomatics, geology, oceanography and planning formally learn about maps at the university level though the level of detail varies according to discipline. Thus, one can hazard a guess that more than 98 percent of the literate population in Ghana is really map illiterate.

It is important to note that maps are very useful in all aspects of human endeavour. For example, banks can visualize the location of their branches and re-strategize their operations. Similarly, insurance companies can use maps to determine premium for certain assets by examining their proximity to hazardous features. The police use maps to study crime hotspots. No matter the discipline, once it has to do with any aspect of the earth surface, maps will prove very useful as aid to explanation. Thus, it is imperative that interest in maps should be stimulated across all sections of society by exploring ways in which maps can be used to enhance geographic explanations. This will be achieved by looking at the concepts of maps, how they are created and also how we can make meaning out of them and use them to understand our environment better. Concept and Definition of the MapThe concept of the map has evolved as graphical or symbolic representation of parts or the whole of the earths surface through antiquity in sand, stone, reeds, parchment and silk. Currently, maps are produced in varied electronic or digital media, including the internet. Thrower defined map as a representation, usually on a plane surface, of all or part of the earth or some other body showing a group of features in terms of their relative size and position (Thrower, 1996: 245). This definition makes the map an image of reality because if a map is a representation of a part of the earth, then everything found at that part or location will be shown on the map. However, it does not represent everything found in that place but only a selection of features that suite the communicative objective of the map. This is because the map has to be readable and the medium on which it is produced is usually smaller than the portion of the earth it represents. Therefore, putting everything found at a specific location will make the map illegible. Because of this, every map has a purpose for which it is made and must be seen to communicate that objective by mirroring that image for us. Accordingly, the features mapped have to be selected, reduced and transformed and then encoded in symbols.

Another definition worth considering is simply that A map is text (Stephens, 2002). Maps have the character of being textual in that, they have words associated with them; they employ a system of symbols within their own syntax, they function as a form of inscription, and that they are discursively embedded within broader contexts of social action and power (Pickles, 1992:193). This suggests that, maps are a form of symbolization, governed by a set of principles with the objective of communicating a sense of a place (Stephens, 2002). Maps have messages embedded in the symbols that they communicate to us. Therefore, in order to make proper use of a map, we need to know how to decode its message and place it within its proper spatial, chronological, and cultural contexts. These definitions of the map suggest that maps give the viewer a great opportunity to have a deeper understanding of the nature of places and offer explanations. It is this aspect of maps that make them powerful for geographical investigations.Types and Classes of MapsMaps can be classified into two main categories based on the purpose or communicative objective for which they are designed. These are Reference (or general purpose) maps and Thematic (or specific purpose). Maps can also be categorized according to scale such as large scale maps, medium scale maps and small scale maps. While it is difficult to give specific scale ranges for these categories, generally maps with scales 1:50,000 or larger are large scale maps; maps with scales between 1:50,000 and 1:500,000 are medium scale maps and those with scales 1:500,000 and smaller are small scale maps. Reference (or General Purpose) Maps Reference or general purpose maps show selected features (both physical and human-made) on or beneath the earth surface as accurately as possible. The communicative objective of such maps is to portray the spatial association of a selection of diverse geographical phenomena (Robinson et al., 1995). Much emphasis is placed on accuracy in terms of positional relationships of the items being mapped. All features shown on these types of maps are treated equally and no special preference is given to any feature, though within a particular feature, some level of importance can be shown. For example, settlements can be classified according to population size and roads can be classified according to surface type, but settlement is more important than roads on general purpose maps. Examples of general purpose or reference maps include the more commonly known and used topographical map. Others include political maps and satellite image maps. With technological advancement, general purpose maps have also gone digital and internet-based. In addition, they have become more user-friendly and interactive such that ordinary people on the street can use them. The commonly used ones include the google earth (http://www.google.com/earth/index.html), google map (https://maps.google.com/), and bing map (http://www.bing.com/maps/).Thematic (Special Purpose) Maps The communication objective of thematic, also called special purpose maps is to portray the structure and organization of a distribution, that is, the character of the whole as consisting of the interrelation of the parts. Thus, thematic maps emphasize some particular feature or set of data using variations or gradations of colour, shading, or symbols to represent classed-differences. For example, census maps focus on population distribution as well as data on variables such as age, ethnicity, and income. Similarly mapquest (http://www.mapquest.com/) and smart phone navigator systems are other thematic maps used for finding directions based on street names and situ addressing systems. Thus, thematic maps can be in the form of choropleth maps, dots (dot-density) maps, graduated symbol maps, value symbol maps, isopleth (isoline), or cartogram, and can be in print, soft or internet-based.

Choropleth maps use colour shading or hatches to represent different quantities or values. Areas with greater values or quantities are usually shaded with darker colours while those with smaller quantities or values are usually shaded in lighter colours. Graduated symbol maps use symbols of different sizes placed within an area to show the value or quantity associated with it. The symbol is often a circle, but it may be one that relates to the maps theme (such as figures of people to represent population data). Isoline or isopleth maps use lines to connect points of equal value, such as temperature, rainfall, or elevation. Lines of equal temperature are called isotherms, lines of equal rainfall are called isohyets, and lines of equal elevation are called contours. Contours are often used on topographic maps.

Functions of MapsBy reference to the communication objectives of the map the functions of the map may be seen as performing a number of roles or functions. As a document, in analogue or digital form, the map is seen as medium for recording of spatial information through the use of cartographic symbols. According to Robinson et al. (1995) if the map is carefully made, it becomes an instrument for recording or documenting, retrieving, analyzing, and displaying a wide variety of spatial phenomena. By ultimately reducing the size and complexity of the world to our normal range of vision and understanding, it makes it possible for us to see the totality of many more and most significant locations, attributes and relationships that exist over large areas. In this respect, Muerchke (1978) alludes to the map as a medium which allows us to carry the world around us in our pocket. Cartographic Abstraction Processes In designing a map, the cartographer needs to know answers to some fundamental questions such as: What is being mapped? Who is/are the audience? How is this map being presented, on its own or as part of a report? What medium will be used to display this map? Answers to these questions will inform the choice of size and structure of the map. These in turn determine the amount of information or data and how it should be represented on the map. The context, content of reality for mapping is so complex that it presents enormous challenges for map construction. A summary of the key transformation routines or procedures for transforming geographical features into the final map is shown in Fig. 2.1. This complexity of the earth must be intentionally reduced in size and content before it is mapped. However, the reduction must be made in such a way that the map does not lose its communicative purpose. The reduction involves processes that are collectively described as cartographic abstraction or generalization (Fig. 2.1). By these processes, the mapmaker represents only the essence of an environmental situation which is defined by the purpose governed by the questions raised above. These processes comprise selection, classification, simplification/exaggeration, and symbolization (Fig. 2.1) Fundamental Information Transmissions in Cartography

Source: Robinson et al. (1995 p. 18).Fig. 2.1. Symbols give meaning to the map and have to be carefully chosen, designed and located or represented in order to convey to the map user adequate and accurate information regarding earths reality. Some symbols intuitively suggest general kinds of data while others use resemblance or look like particular data or concepts. For example, a map showing population of settlements in a country or region may use dots of varying sizes to signify variation in population sizes. A city map may also use dots, triangles, squares, etc., to show the different kinds of data such as restaurants, residential houses, stores, electric poles, boreholes, etc. In the case of resemblance or look like symbols, a map may use a picture or semblance of a monkey to show a monkey sanctuary or a crocodile to show a crocodile pond. Map symbolization can rarely stand alone. On the map face, explanatory aids such as titles, legends, inserts, projection, scales and direction indicators are indicated as standard components of map

Map of Ecological Zones of Ghana Map of Ecological Zones of Ghana Source: Authors.Fig. 2.2.24 Geography composition called the map layout. These, including the map itself, publication or compilation notes such as data source, date and author-ship, give context to the mapped area as indicated in Fig 2.2 and 2.3. The illustrations give indication of different possibilities for the arrangement of map elements or components. This is a form of graphic art and there-fore cartographers have to consider that the layout of all map elements create a final product that is informative, accurate, and aesthetically pleasing. Visual balance is always an important consideration for design of the map layout. A properly designed map layout is very essential for explaining geographic content and context.Explanatory Power of MapsExplanation in geography is concerned with either understanding the spatial distribution of objects on the earth surface or to explain the processes that lead to a particular spatial distribution, spatial variation or spatial differentiation. Maps perfectly aid this process as you may not need to commit extra resources to visit the area before offering an explanation. Maps perform this task by calling into play their traditional functions for which they have been created. These functions are first to store information and secondly, to provide a picture to relay spatial information to a user. Explanation starts with gathering information about the objects or identifying the objects and then piecing the information together in a meaningful text. The information stored on the map depends on the communication objective. Descriptive information about objects can be found in the legend while the locational information is obtained from the map itself or map face with the aid of the grids and orientation (north arrow). Location information usually involves measurements such as coordinates, distances, elevation and bearings (or directions) but it is advised that the reader should refer to any cartographic book (see suggested reading) to learn more about the measurements. All these kinds of information, location or descriptive (quantitative or qualitative) that are found on maps) are used to explain the spatial distribution and/or perform spatial analysis which is at the core of geographic explanation.A Topographical Map of Wiawso, Western Region, Ghana

Source: Authors. Fig. 2.3Explaining Spatial DistributionSpatial distribution refers to the geographical arrangement of the individual objects or phenomena found in a place. It considers such arrangement in terms of pattern, density and dispersion. Pattern is the geometric arrangement of phenomena. The objects can be arranged in order or out of order (i.e. regular or irregular), thus, pattern can be regular or irregular. For example, an area that is well planned will have regular road network with the houses laid out in a regular pattern. Density is the number of objects/phenomena per unit area. An example here could be the population density (i.e. the number of people per square kilometre) or housing density (i.e. the number of houses per square kilometre). In determining density, the number of objects in a place is divided by the area of that place. Lastly, dispersion is how spread out from each other the objects/phenomena are or how far apart they are. The question for the map user is, how do maps help us to achieve the explanation of spatial distribution?

As the map is an image or picture of the earth surface, the spatial distribution of the objects are shown in their relative positions and sizes as illustrated in Fig. 2.4 which is a satellite image view of part of Accra, covering parts of Nima 441, Maamobi, 37 Military Barracks and Kanda. This is an urban area and most of the objects in there are buildings and other structures put up for human habitation and commercial purposes. The entire area is used up for development. At the west of the Kanda Highway, the structures are more closely packed than on the eastern side, giving a relatively clear indication of dispersion. There are also more trees at the right of the highway than the left. It is also clear that the structures and the road network are better planned to the east of the highway than to the west. All these clearly show the spatial distribution of human activities in the area and these will be clearly shown on a map, however, reduced through the cartographic generalization processes and may be represented by abstract symbols or a combination of abstract and pictorial symbols.

The spatial distribution on the map can then be described in terms of its specific pattern (i.e. whether the objects are regularly or irregularly arranged); density and dispersion. For example, using a 1km2 buffer on both sides of the highway in Fig. 2.4, the Nima-Maamobi side will have a higher number of structures than the Kanda-37 side. Satellite Image Map from Google Earth Showing a Section of Accra

Source: Google.earth, 2012.Fig. 2.4.

This image shows a clear indication that the Nima-Maamobi side has higher density than the Kanda-37 side. The eastern corridor has a regular pattern of road layout and houses than on the opposite side to the west. Spatial distribution helps to explain spatial/areal differentiation. The Kanda-37 military side of map has more trees than the Nima-Maamobi side. This aspect is synonymous to descriptive explanation. The map also permits associations and relationships to be established among the varied features over the surface of the earth. For example, a map shows how the road network relates to the location and distribution of settlements and how these arrangements have been influenced by the topography of the land. The road network in a town will obviously be denser than the road network in a village. Spatial Analysis Spatial analysis is also an important component of explanation. This seeks to provide an understanding of the relationships and interactions between the observed locational pattern of objects in 2-dimension space and other attributes. So one may ask the question, why are there more trees at the Kanda-37 barracks side than the Nima-Maamobi side in Fig. 2.4? This is a question that elicits information about the processes that lead to the differences in the area or spatial differentiation resulting from human-environment interaction. In putting up buildings, for example, trees have to be felled. Since the buildings at the Nima-Maamobi side are compact, nearly all the trees have been felled to give way for the construction of buildings.

We can also use maps to explain the relative proximity of objects to certain occurrences. For example, if there is flooding in the area shown in Fig. 2.4, the houses that are closer to Nima gutter (a choked stream) will bear the impact more than those farther away. Also, the Nima 441 side has no access route. In the event of a fire outbreak in this area, it will virtually be impossible for the Fire Service to get access to the fire point and a hydrant in the area. Additionally, it can also be inferred from the image that the quality of life in Nima-Maamobi is poor. This inference is made from observations such as the density of the buildings, the lack of open spaces or play grounds, health and educational facilities, lack of access routes among others. With reference to a map showing the housing density and the road network, one can tell how risky a place is in relation to fire or any other hazard. This type of map analysis may be of particular interest to the insurance companies in determining premium for properties to be insured against hazards.

Map interpretation may also reveal notions of distance decay. This denotes the decreasing occurrence of events, activities, and effects with increasing distance from the location from which these things originate or from which they exert influence (Amedeo and Golledge, 1975) and can be explained more effectively with the aid of a map. Distance decay can be related to Waldo Toblers First Law of Geography which states that Everything is related to everything else, but near things are more related than distant things. It can be applied to a range of different geographical concepts/subjects. For example, the effect of an earthquake decreases as you move away from the center of the quake and this can be vividly mapped. Thus, in a map of earthquake zones, the risk of objects (more especially human activities) can be explained based on distance from the epicenter of the quake. Another distance decay application of map is the study of spread of contagious diseases. This can be neatly depicted on a map for visualization. Spatial analysis also considers space-time processes which focus on modification of spatial patterns by movements of phenomena or human-environment interactions. An example of this type of analysis can be seen in urban studies. In this case, maps of different time periods of the same place are compared and the changes that have taken place explained in spatial terms. The maps may also contain information on other processes such as population, economic activities and so on that will help explain the processes that have led to the expansion or shrinkage of the town. The mapped information from satellite imagery in Fig. 2.5 shows that the settlement of Tamale has expanded between 1989 and 2005.

The patches shown in red represent built-up areas and these have increased significantly between 1989 and 2005. The expansion of Tamale Township can be attributed to rapid population growth, leading to conversion of more land to build houses to accommodate the growing population. From the figure, it can be seen that some of the villages that were located far away from the city are now part of it. These localities are losing their economic base of land and are becoming poorer. A utility company can look at this and plan on expanding service to the newly developed area. An agriculturist can also use the information to determine the impact (positive and negative) on agriculture as the growing population not only provides a market for agricultural produce but also consumes the land used to produce food.

To the environmentalist, the expansion of the city has a negative toll on the environment. For instance, the expansion leads to the conversion of land for residential and industrial facilities and destroys vegetation and habits, resulting in biodiversity loss. It also forces people to settle in areas that were not originally suitable for settlement, making them prone to floods and other hazards as well as sealing the land surface and causing more runoff. To the economist or economic geographer, he/she will consider expansion in two ways with the economic lens: the opportunities the expansion offers in terms of trade, transportation, services, etc., and the loss of jobs due to loss of land for agriculture. Maps of different time periods can also be used to explain changes in cultures as they capture and store information on different cultural practices or human behaviour at a point in time. These types of maps are also useful in explaining changes in the environment and whether those changes are deleterious or not. For example, if a place that once had a vibrant forest is seen on another map with the size of the forest shrinking or even the forest disappeared, then it means that there is deforestation going on in that area.

The Growth of Tamale

Source: www.glcf.org (classified satellite images).Fig. 2.5. In order to explain the processes that led to the deforestation, proximity to human activities and the underlain geological formation will provide useful information. For example, if the area has precious minerals, then surface mining could be the cause of the deforestation. If on the other hand, the area is close to settlement that was not there previously or has expanded, then the deforestation could be due to clearing the land for settlement and farming to feed the growing population. These type of maps used for environmental change studies are often called land use land cover maps.Dynamic Character of MapsMapped information is increasingly being stored and manipulated digitally to produce maps to serve different purposes. In this regard, geographical data can be added or subtracted within the digital mapping algorithm to generate the desired maps. This additional functionality given to maps by technology makes it possible to visualize changes on the same map and even estimate the quantity of such changes. As such, maps are no longer only static but also dynamic. The human-environment interactions result in daily changes and these changes need to be captured and mapped. This means that maps will continue to change in nature, content and character. It is now possible to capture change and update the information regularly for mapping in real time thanks to technology. This is possible through the use of modern interactive technology, including Remote Sensing (RS), Geographical Information Systems (GIS) and Global Positioning System (GPS) techniques. Map making is also becoming less technical and therefore everybody can create a map with little tutorials. The internet has also become a warehouse of maps and data and thus at the click of a button, one can download a number of maps. However, digital maps must be used with caution since such maps could have their associated errors.Beware of Errors in MapsAs Monmonier (1991) cautions, we need to understand that no map is a totally truthful representation of the world. All maps lie but some lie more than others. Maps are not accurate because they are projections of spherical earth onto a flat medium. For example, the choice of projection could make the size of Greenland appear as big as Africa, or a country like Togo look larger than Ghana. This is an exaggeration by using a projection that exaggerates size but preserves shape. As stated earlier, no projection is perfect. All projections are pregnant with distortions but the distortions are minimized if the area to be projected is small. Besides projection, maps are also scale representations and therefore cannot perfectly contain all information on the surface of the earth.

Mapped information, therefore, necessarily undergoes cartographic generalization or abstraction procedures and finally represented by symbols. As a result, in placing the information, priority is given to some features within the general context of data to be mapped. For example, if a river, road and railway pass through the same area, the river being a natural feature of the environment will be placed first, followed by the road and then the railway. This procedure will certainly displace the road and the railway from their true positions. Thus, to ferret out the truth, you need to know how to decode the messages of maps and place maps into their correct spatial historical context (Stephens, 2002). However, there is no cause for alarm because precautions are always taken to ensure accuracy. Every map has an allowable error to make, which is so small that measurements made on the map are accurate. A projection that distorts area cannot be used to compare area of places or for statistical analysis. Projections are, therefore, stated especially on small scale maps to inform the user about the accuracy of the map and what use to put the mapped information.ConclusionExplanation using the map is concerned with understanding inter-relationships among location, character, and arrangement of natural and cultural features and their interactions on the surface of the earth over time. Different types of thematic maps are used by geographers alongside diagrams, tables and written accounts. The map can yield significant amount of information in the hands of the skilled user. It is for this reason that it has been described as the geographers most useful resource. It is the belief of the authors that this chapter will stimulate the interest of the reader to take a second look at maps and seek to understand the messages encoded on them. Despite the power of maps as explanatory tools, very few scholars outside of geography use maps and some people are intimidated by them. As is evident in the examples provided, professionals outside geography can no longer use maps as decorative pieces, but more usefully in interpreting and understanding earth reality. References Amadeo, D. and Golledge, R. G. (1975). An Introduction to Scientific Reasoning in Geography. New York: Wiley.Brown and Hatton (1982) Explanations and Explaining: A Teaching Skills Workbook. Macmillan Education, 63 pp.Kimerling A. J., Buckley A.R., Muehrke P. C., and Muehrke J. O., (2011). Map Use: Reading Analysis Interpretation 7th ed. ESRI Press.Monmonier, M. (1991). How to Lie With Maps. Chicago: University of Chicago Press.Peterson, M. l P. (1995) Interactive and Animated Cartography. New Jersey: Prentice Hall, EnglewoodCliffs.Pickles, J. (1992) Text, Hermeneutics and Propaganda Maps, in Barns and James S. Duncan, eds., Writing Worlds: Discourse and Metaphor in the Representation of Landscape. London: Routledge, 1992, 193.Robinson, A. H., Morrison, J. L., Muehrcke, P. C., Kimerling, A. J. and Guptill, S. C. (1995) Elements of Cartography. New York: John Wiley & Sons. Stephens, D. T. 2002 Making Sense of Maps, History Matters: The US Survey Course on the Web, http://historymatters.gmu.edu/mse/maps. Thrower, N. J. (1996). Maps and Civilization: Cartography in Culture and Society. Chicago: University of Chicago Press.Suggested Further ReadingsCampbwll, J. (2001). Map Use and Analysis (4th ed.). New York: McGraw Hill.Erbynn, G. K. (1996). Comprehensive Map Work for West African Schools. Scotland: Heinemann.Harvey, D. (1969) Explanation in Geography. London: Edward Arnold. p. 521.Keates J. (1989) Map Design, Construction and Cartographic Symbolization, 2nd ed. Keates J. S. (1972) Symbols and Meaning in Topographic Maps, In. International Year Book of Cartography, No. 12 1972, pp. 158-181.Kime P. (2009). Maps and the Basis of Symbolization. The Journal of Jungian Theory and Practice. C. G. Jung Institute of New York. Vol. 11, No. 1, 119.Nimako, D. A. (1982) Map Reading for West Africa. London: Longman Group Ltd, UK.Pritchard, J. M. (1984). Practical Geography for Africa. London: Longman Group Ltd, UK.

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