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Topic 6 – Cartographic Composition. A – Cartography B – Elements of Map Composition C – Cartographic Elements D – Symbolization. The Purpose of this Course. Understand how elements composing a map should be arranged. Know what elements should be placed on a map.
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Topic 6 – Cartographic Composition A – Cartography B – Elements of Map Composition C – Cartographic Elements D – Symbolization
The Purpose of this Course • Understand how elements composing a map should be arranged. • Know what elements should be placed on a map. • Use the appropriate symbolism to represent features correctly.
A Cartography • 1. Maps and their Uses • 2. Efficiency and Mapping • 3. Cartography and GIS
1 Maps and their Use • Mapping is a communication tool • Convey a message to a public through a medium. • Some forms of communication are better than others. • All maps are not equal, even if some are representing the same features. • Cartographic quality. • Maps are using visual communication tools. Information Message Map Cartography Map reading
1 Maps and their Use • Recording and Storing Information • Enterprises and institutions are using maps to store large amounts of information. • Location of resources. • Location of people. • Parcels. • Property. • Infrastructure. • Utilities. • Etc…
1 Maps and their Use • Analyzing Distributions and Patterns • Maps can be used to analyze spatial distributions. • Visualization helps conceptualization of patterns and processes.
1 Maps and their Use • Presenting andCommunicating • Express concepts and ideas that are verbally difficult and complex to portray. • Demonstrate. • Convince. • Persuade. • Inform/Misinform.
2 Efficiency and Mapping • Cartography • Science / art / technique of map production. • Uses a set of defined graphical elements to communicate a message. • Graphical elements specific to cartography • Coordinate systems. • Map projections. • Scale. • Symbolism. • Legend • Explaining the meaning of graphical symbols. • With the large diffusion of maps, some symbols do not require explanation anymore.
2 Efficiency and Mapping • Symbolic abstraction • Encoding real-world geographic features. • How much to simplify? • How to symbolize?
2 Efficiency and Mapping • Designing a Good Map • A good map conveys well its intended message. • What is the goal of the map? • What the reader should gain from the map or how the reader should respond. • Motives vary greatly. • Convey accurate information about spatial relationships. • Sway public debate. • The motive will have a great bearing on the content of the map (the information included) and its form (the cartographic strategies employed).
2 Efficiency and Mapping • Who is the reader? • Map design is not the same according to the intended public. • Identify the type of reader being addressed. • Important to have an idea about what the audience is likely to know about the subject matter of the map. • Map literacy: • How much background the readers have in using maps. • A map intended for specialists who have a background in cartography might be organized far differently than one intended for use in a public debate.
2 Efficiency and Mapping • Where it will be used? • Usage depend on the type of medium the map will be published in (book, magazine, news, web site, etc.). • Some maps are used only once and then discarded. • Others are intended to used for reference for decades or centuries. • What data is available? • Some maps use reliable sources while others have sketchy information. • Decisions about map design are tempered greatly by source materials themselves. • What resources and equipment are available? • Underline the time and the costs for map production.
3 Cartography and GIS • Explosion in the generation of maps over the last decades • More information is available from several sources. • Information is more accurate and in numerical format. • GIS enable to produce maps at a very low cost. • The population have more map-reading skills. • The Internet: • Massive distribution of graphical images such as maps. • Access to a wide array of public databases.
3 Cartography and GIS • Automated Cartography • Computing mapping is a revolution that could be compared to the word-processor for writing. • GIS automate several aspects of the cartographic process. • Assist cartographers for tasks that previously took a lot of training, time and manual expertise. • Map revision is enhanced as errors do not involve starting over again. • Can adjust the layout, the composition and symbolization. • One map can be duplicated “ad infiniti” to form new maps with the same base map. • “GIS don’t make good or bad maps, cartographers do”.
3 Cartography and GIS • Future of cartography • Virtual maps: • A truly “digitized world”. • Official base maps and datasets available for everyone to use. • 3-D maps. • Animated maps.
B Elements of Map Composition • 1. Format of Final Production • 2. Generalization, Simplification and Abstraction • 3. Common Elements • 4. Balancing Elements • 5. Map Layouts
1 Format and Final Production 3” • Final format • Size and the media will determine the map-making process. • Size influence the level of detail and the quantity of information. • Media determines the availability of colors, patterns and lettering. B&W Insert in an article 5” 24” 24” Poster
2 Generalization, Simplification and Abstraction • Cartography is a process of abstraction • Features are generalized and simplified. • Not all elements are relevant to the message a map convey. • The reader must have his/her attention of the message portrayed by the map. • Detail • Too much details undermine the message of the map. • The amount of detail is related to the scale of the map. • A small scale map must be generalized. • A large scale map can contain more details at the expense of generalization.
2 Generalization, Simplification and Abstraction
2 Generalization, Simplification and Abstraction
3 Common Elements • Basic set of elements • Title. • Scale. • Legend. • Body of map. • North arrow. • Production Date. • Projection Used. • Sources. • Most elements are found on all maps, but some are more context sensitive.
3 Map Elements Title Neat line The United States of America Legend Scale Background Washington,D.C. National Capital Alaska 0 1 2 3 4 Hawaii hundreds of kilometers 4 Lambert Conformal Conic Projection 0 4 0 Source: U.S. Dept. of State Inset Place name Credits
4 Balancing Elements • Concept • Each map element has its own importance. • The cartographer must organize them according to priority. • Important elements should be in prominent positions within the map. • Important elements should have an according size; a larger area. • A general rule: • The most important elements should be on the top left. • The least important elements should be on the bottom right.
4 Balancing the Importance of Elements Most important information Visual Center Least important information
4 Balancing Elements • Placement • Importance should also be given to the placement of elements within the map frame. • Distribute evenly to avoid crowding and blank areas.
5 Map Layout • Rules • Only experimentation tells which layout is the best. • It used to be a costly and long experience. • Today, GIS packages enable to do this easily.
5 Map Layout • Relevance of the elements on the map • Each one should be justified. • Those of less importance should be simplified. • Those of importance should be explained. • Simple design are more readable. • Too much detail and complexity will confuse the reader. • The rules are generally vague, so it is to the cartographer to develop his/her “style”.
C Cartographic Elements • 1. Distance and Scale • 2. Direction • 3. Legend • 4. Sources • 5. Context Sensitive Elements • 6. Effective Communication Elements
1 Distance and Scale • Distance or scale • Must always be indicated or implied. • Except in the case where the audience is very familiar with the map and the distance portrayed. • Verbal, numeric and graphic scale. • Graphic form is often preferred: • Map are drafted at a different scale than they are printed. • If verbal and numeric scales are used, the cartographer must make sure that the map is printed at the precise scale indicated. Verbal 1 inch equals 10 miles Numeric 1:50,000 Graphic
2 Direction • Conventional North • The top of the map is the True North, that is the direction of the North Pole. • If the top of the map is not the true north, an arrow indicating the direction of the true north should be placed on the map. • Magnetic North • Changing according to the geophysical conditions of the earth’s crust and core. • Navigation maps both contain the magnetic north and the true north. • Compass readings show the magnetic north and adjustments are made to find the true north. Adjustment to be made (declination)
2 Direction - Some Examples Where is north on this map? Where is north on this map?
3 Legend • Nature and placement • List of symbols used on the map and their significance. • Symbols on the map should look exactly the same on the legend. • The choice of symbols is open, but they should portray a good abstraction. • Some conventions are difficult to escape from. • Often, legends are not necessary if textual annotations are put directly on the map. • Legend should be placed on an empty part of a map to create some balance.
3 Legend
4 Sources • Sources • Since a map is an information medium, it must be referenced. • Source for the base map. • Source for the information portrayed on the map (mostly for thematic maps). • Possibility to verify information and the way it was interpreted. • Age, accuracy and reliability of data is important. • Also relevant to indicate how the data was processed, grouped, generalized and categorized. • Only consider cities of more than 20,000. • Classes are equidistant.
5 Context Sensitive Elements • Title • One of the most essential feature. • Its design should be related to the audience. • Captions usually take the place of titles in maps for books and journals. • Should be comprehensive: • Avoid things such as “Map of…”. • Avoid long descriptions. • “A map of the population growth in Canada between 1980 and 1990 displayed by province” with “Canada population growth by province, 1980-1990”. • “Colonies controlled or ruled by Spain on the eve of the Spanish-American War” with “The Spanish empire in 1898”
5 Context Sensitive Elements • Projection • Influences the representation of area, distance and direction. • An experienced cartographer can identify the projection simply by looking at the map. • Choose the appropriate projection for the mapping context. • Some projections are incompatible with some representations. • The projection used should be indicated on the map if precision is important. • For several thematic maps, projection is factual. • Projection is mandatory for maps to be used in the digitizing process. • Projection is indicated on all topographic maps.
5 Context Sensitive Elements • Cartographer • Name (initials) of the person(s) responsible for the map production. • Could also be a corporate identity. • Seal of approval since the cartographer is linked to his(her) output. • Production date • Several map are time sensitive. • The reader must thus know when the map was produced to understand its context. • Illustrates how old is the information, and thus its accuracy. • For some maps, the year is all what is needed. • For maps, such as weather maps, the time precision can go up to the minute.
6 Effective Communication Elements • Neatlines • Used to frame a map and to clearly indicate where it begins and ends. • Also used to clip some area out of a locator, inset or index map. • Some maps do not need neatlines, notably when they are well-known maps. Northeastern United States
6 Effective Communication Elements • Locator • Some maps show a location unfamiliar to the reader. • It is useful to put a locator map portraying where is location in relation to a wider area. • Inset • Information on a specific part of a map may be too dense. • Useful in this context to put an inset map to zoom in. • Index map • Limit to the amount of information that can be put on a map. • Useful to place labels and other information on an index map.
6 Effective Communication Elements- Locator, Inset and Index Maps
6 Effective Communication Elements- Locator, Inset and Index Maps
D Symbolization • 1. Visual Resources • 2. Symbolization Strategies • 3. Typography • 4. Foreground and Background • 5. Category Ranges
1 Visual Resources • Visual resources • Used to draw attention on map features. • Wide range of resources. • Varies according to the nature of the information being mapped. • Modification of visual elements • Can be modified by color and geometry. • Color modifications • Hue. • Texture. • Intensity. • Geometric modifications • Shape. • Size. • Orientation. COLOR Hue Texture Intensity GEOMETRY Shape Size Orientation
1 Visual Resources • Visual resources and geographical features • Different geographical attributes can be represented. Location Direction N Distance 10 km Movement Function Process Correlation
Cartographer's Conception Point representation Line representation Area representation Volumetric representation Tel. poles Animal range Phone line Tree Point objects Housing density Animals Airport Q Highway X Line objects Road density Stream Watershed Real World Phenomena Chemical spill Right of way Area objects ¥ Forest cover Administrative division Volumetric objects R Proportional symbol Open-pit mine Mountain range Valley 1 Visual Resources
Swamp Town Road Boundary Desert Q Airport River Forrest 2 Symbolization Strategies • Three levels of measurement • Nominal (qualitative) data. • Ordinal data. • Ratio (quantitative) data. • Nominal Data • Information is grouped in categories on the basis of qualitative considerations. Points Lines Polygons
Large Highway Affected area Medium Road Street Risk area Small 2 Symbolization Strategies • Ordinal Data • Grouped by rank on the basis of some quantitative measure. Points Lines Polygons
30 40 50 Each dot represents 500 persons 100 Contour 15 10 20 5 Flow Population density Proportional symbols 2 Symbolization Strategies • Ratio Data • Information that can be arranged along a quantitative scale. Points Lines Polygons