32 Map Designing

Prof. Masood Ahsan Siddiqui

The term design normally refers to the planning of a map particularly to the choice and arrangement of its graphic elements. For GIS, graphic output must show the features appropriately symbolized or labeled and the relationships are discernible. The map design process includes making decisions about the selection of geographic features and attributes to be represented on the map, selection of an appropriate map projection given the purpose of the map and the geographic region of interest, choice of an appropriate scale, selection of appropriate symbolization, and design of the overall layout of the map.

The quality of map to a large extent depends on the quality of hard copy maps. Therefore, design of graphic output is critical if accurate information is to be conveyed effectively to the user. The map design process is especially important because maps are a synoptic form of communication. The aim of cartographic design is to present the geographical data in such a fashion that the map as a whole appears as an integrated unit and each item is clear and legible. Graphic output from GIS is often poorly designed. For example, there rarely exists any appropriate scaling of colours or patterns. The principles of cartographic design are not considered at all. The map is what distinguishes GIS as a different approach to the management of information, so extra care should be taken to improve the final maps that a GIS generates. The issues of graphic design in GIS has become more important because of the fact that screen display introduces a new set of issues as it has greater capabilities compared with paper maps. The concepts of designing is about the following three aspects which are as follows;

The purpose of design is to capture the attention of the user

The Principles of Cartographic Design are Timeless, the Results are not

The Rules of Cartographic Design can be taught and learnt, principles and concepts have to be acquired

There are five basic principles of map designing. These are ;

1. Concept

2. Hierarchy

3. Simplicity

4. Maximum Information

5. Understanding

Concept here means that the developer should have a clear idea about the purpose of the map and the nature of its user. While designing, the entire objective be incorporated and it must be complete in itself. Design comes in two stages, concept and parameters, and detail in execution.

 Hierarchy

Important things must look important, and the most important thing should look the most important. Lesser things have their place and should serve to complement the more important aspects.

Simplicity

The beauty of designing that is simple and straight forward. Maps are developed for others so the important aspect of it is not what you put in that makes a great map but what is inferred from it. This is the designer’s skill. Content may determine scale or scale may determine content, and each determines the level of generalization.

Maximum Information

How much information can be gained from this map, at a glance? Functionality not utility is the key. Design makes utility functional. All designs are a compromise. The spark which makes a map special often only comes when the map is complete.

Understanding

Good designers use Cartographic fictions, Cartographic impressions, and Cartographic illusions to make a map. The image is the message. Good design is a result of the tension between the environment and the designer. Design uses aesthetics but the principles of aesthetics are not those of design.

Elements of map design

The features, symbols, and text, their relative placement and, the process of choosing the information to be conveyed and the audience for which it is intended, balance, contrast etc. are the key elements of map designing. The proper design for other types of geographic information (charts, graphs, etc.) can be considered as a sub-set of proper map design.

Some elements are found on almost all maps no matter what the theme, others depend heavily on the context in which the map will be read. The best GIS database may be a failure, if the information it contains is not displayed effectively. The basic elements are;

Figure1: Elements of map design

Contrast

No element of cartographic technique is as important as contrast. Sharpness of a map is determined by the contrast. Contrast may be achieved by varying the appearance of lines, shapes, size, patterns, colour, value (intensity) and direction. A map has number of linear features such as coastlines, rivers, railway lines, roads, and various political boundaries. In order to distinguish them; it is necessary to vary their character, size, shape and pattern. Visual contrast can be based on any of the graphic variables. Though visual contrast is necessary and can enhance the interpretability of the map, but too much of it can detract from the clarity and order of the map.

Pattern

Patterns are composed of dots, lines or combination.  It has the following characteristics:

(1)Texture: It relates to the spacing of the marks and usually specified by the number of lines / dots per inch. The greater the number, the finer is the texture.

(2) Arrangement: It refers to the relationship of the positioning of the marks, such as parallel lines, crosshatched, arrangement of dots. It must be noted that while placing dots, don’t follow any defined pattern.

    (3)  Orientation: It refers to positioning of the arrangement relative to the viewer as vertical, horizontal or diagonal.

(4)  Value refers to the relative darkness.

Use of Colour

The use of colour on maps serves more purposes than to just construct a legend. Colour conveys visual meaning. It directs attention and it can emphasize or obscure features. Thus, colour selection is an important element of map design. The human eye can distinguish tens of 1000s of different colors, but only 20-30 gray tones. The eye is also able to identify patterns and boundaries (edges) and detect movement.

On a static map, however, the eye cannot reliably match more than 16-20 simple colours from the legend of the map. This limited ability can be expanded by the addition of pattern elements (symbols) to the basic colours. Still, there is a practical limit to how many colours should be displayed on a map. Maps are easiest to interpret when the number of colours does not exceed 10 to 12. Too many colours (>20) create a map that is visually cluttered.

The nature of colour and human perception of colour are one of the most important elements in cartography. Blue, green and red are the primary colours, also known as additive colours because they can be added together to create all visible colours of the spectrum. Colours may also be created by subtracting an additive colour from white. For example, white-red=cayon= (blue+ green).

Colour printing (newspapers, books) is based on subtractive colors (plus black), whereas color video display (television, monitors) is based on additive colours. In printing a colour document from a computer display, the printer must translate additive colours into corresponding combinations of subtractive colours. The Munsell colour code is the internationally accepted standard for describing colour quantitatively.

Figure 2: Munsell colour scheme

Colour has three major aspects namely, (1) hue (2) value, percent reflectance, lightness or brightness and (3)Chroma also termed as saturation or intensity. These three have been employed in the Munsell system.

When we speak red, green or blue, in fact we are describing the hue. Value of the colour is sensitivity of the colour. The tones of the scale value range from black to white and referred as gray scale. Chroma refers to the reactions of the eye to the colour. It also refers to saturation, which is the amount of hue in a colour.

The colours on monitor are additive colours. When all the three basic colours are added, this will lead to a white sensation. The standard VGA colour monitor can display 16 colours from a total colour selection of 262,144 (64³). Super VGA monitors can display up to 256 simultaneous colours from a total of several million possibilities. More advanced monitors can display still more colours.

Colour may carry standardized meanings in certain specific applications. For example, blue for water bodies, green for vegetation, brown for desert/mountains (contours), white for ice or snow, etc. A standard colour scheme is often used on geological maps: green for Cretaceous, yellow for quaternary, blue-green for areas below sea level, green and yellow for lowland and hills, brown for mountains, red for forest areas over 5000 meters etc. The effect was meant to be that areas appeared to be nearest to the viewer were in fact farthest from the sea level.

The sequence of colours in a legend serves an important function in showing the visual relationship of map features. A smooth sequence of colours best shows data that are continuously variable. It is recommended that instead of varying colours we should vary the tones. Dissimilar colours create visual barriers between features that are not related to each other.

Balance

Balance here means, distributionof the elements as evenly as possible within the map frame to avoid unnecessary crowding and conversely, large blank areas. In other words, the relationships between the visual components should appear logical and the map should be legible. The most important elements in a given design should be featured in more prominent positions and occupy a larger area within the frame. It is advised that the most important information should be placed near the top or to the left of the map. Less important and ancillary map elements can be positioned toward the bottom and right. In this way, the importance of the various map elements can be matched to the visual hierarchy of the map itself. Visual balance is affected by:

the “weight” of the symbols

the visual hierarchy of the symbols and elements

Figure 3

Title:

The title should be written in a larger, bold font than any other supporting map text or annotation for greater emphasis. The title has to be placed at the top of the map. It is often useful to include the location of the map elements in the title. use of abbreviations or unspecified acronyms in the title should be avoided.

Legend:

The map legend explains the meaning of the point, line, and area symbols used to represent features on the map. Every symbol that appears on the map should necessarily appear in the legend, and it must appear exactly as it does in the body of the map. Legends are generally used for depicting qualitative data whereas for quantitative data the term index is preferred.

Visual Hierarchy:

Perhaps the most important design decision is to ensure that the relative importance of information shown on the map is reflected in the choice of symbolization. Unnecessary information should be eliminated and relevant information be symbolized in a way that makes more important information visually more prominent. This requires careful consideration of the map purpose as maps with different purposes may display the same geographic features but with different emphasis.

The visual hierarchy of a map can be enhanced by manipulating figure-ground relationships. The human eye-brain system automatically separates visual images into background and foreground. In the context of maps, the background is typically base map information, which shows the spatial context for the thematic content of the map. Figure-ground relationships can be manipulated to distinguish land from water, or the thematic content of the map from the base map.

Figure 4 : Map Elements

Location:

It is imperative to include some description of the location of the features on the map. The location of the map features may be given in the form of geographical or some other well-accepted coordinate system. Besides, the inset map may also be given along with the map for displaying the location of the map within a larger area on small scale.

Sources:

Every map is a collection of information. All sources of map information must be referenced. The source should include the date, title, author, publisher, and any other known and other pertinent information.

Projection:

Almost all printed output of geographic data is projected onto a flat surface. Since this transformation results in some kind of distortion, it is mandatory that the projection system be mentioned so as the type and distortion can be assessed.

It should include; name of the projection, central meridian, zone, the datum and spheroid. In the case of a large-scale map, which covers a small area, the map projection may be omitted from the map.

Text Characteristics:

There are several text characteristics that can be manipulated by the map designer. Text style is commonly used to distinguish between different types of features. For example, upright characters are generally used to represent land features, while italics are often used to label water bodies. The form of text characters can be used to indicate the relative importance of features. Form refers to the text font. Although there are many fonts available, they can be grouped into two broad classes: serif or sans serif.

Serifs are semi-structural details on the ends of some of the strokes that make up letters and symbols (also known as Roman).

Figure 5: Serif letter

Sans serif fonts are the simplest. Arial is the typical example of Sans serif font. These fonts are often used on maps to label relatively minor features.

A typeface without serifs is called sans-serif, from the French sans, meaning “without” (also known as Gothic). In traditional print, sans-serif fonts are more typically used for headlines than for body text. Sans-serif fonts have become the de facto standard for body text on-screen, especially online.

Figure 6: sans-serif letter

Serif fonts such as Times New Roman may be used to identify features of greater significance. For example, cities might be labeled using a sans serif font but capital cities might be labeled with a serif font. The size of the letters can also be used to indicate importance. Size refers to both the height of the letters (point size) and their weight (normal, bold). The spacingof lettering can be used to indicate feature extent. Point and line features are generally labeled using closely spaced lettering, while areal features are labeled with widely spaced lettering to show the extent and orientation of the feature. Placement and orientation of the text is used to indicate the location and extent of features.

Placement of the text:

Placement of lettering on maps is more important on reference maps that typically label many geographic features than on thematic maps. On thematic maps, text is often limited to the title, legend and other peripheral information. Labeling of features on the map involves trade-offs between locational precision and legibility. Placing of label points on maps is an important aspect of map design as they provide the greatest flexibility to attach descriptions to point, line and area features. If properly placed, it identifies the phenomenon to which it refers. In contrast, poorly placed label may carry some other meaning. For making a map user friendly and meaningful, standardized format for label placement has been developed. Some general rules for text placement are; names should be legible and easily associated with the features they describe

Do not break names

Do not extend names along rivers or other line features

If possible, place river names in downstream direction

Closely associate name with feature

Do not bend names excessively

Place so as to show the extent of the feature

Reflect the hierarchy of features by the use of different font sizes

Not be densely clustered nor evenly dispersed

Figure 7

Names should be either entirely on the land or on the water

Lettering should generally be oriented to match the map orientation. That is, it must be parallel to the upper and lower edge of the map for the large scale and parallel with the parallels for the small-scale maps.

In case of conflict between lettering and data, the data should be interrupted not the names.

Care must be taken that there is no over posting (overlap). Though labels must be positioned to avoid over posting, but without destroying the eye’s ability to associate labels with appropriate features.

Figure 8: Line labeling

Source: The Geography craft

Point Labeling:

Optimum position for a label is above and to the right of the point. Below and to the right is less acceptable. The least acceptable position is to the left and below of the point. Label can be turned (non-horizontal) if necessary, but only by a small amount (Figure 12.13).

Figure: 9: Point Labeling

Source: The Geography craft

Polygon Labeling:

Labeling of polygons within automated mapping is difficult and challenging programming problem. The label should be central to the feature, may be reoriented or curved to fit the feature. In some cases the label may be connected with the feature by an arrow.

Diagram Labeling:

Labeling of diagram is generally a matter of trial and error. Search for feasible positions for a rectangle wholly enclosed within the polygon. The ratio of width to height should be as high as possible. If the nature of the data suggests the shape of the graphic, follow that suggestion – otherwise, move toward horizontal graphics about 50% wider than tall.

While mapping, always follow the traditional cartographic symbols and colours. For example, water in blue colour, forest as green, contours in brown, grid lines in purple, cropped areas as yellow etc. By straying from these traditional methods of symbolization the map may be misinterpreted.