Designing Maps GTECH 201 Lecture 19 Yet Another

Designing Maps GTECH 201 Lecture 19

Yet Another Definition n “A graphic depiction of all or part of a geographic realm in which the real-world features have been replaced by symbols in their correct spatial location at a reduced scale. ”

Cartographic Design Principles n Audience and purpose n Size, scale, and media n Visual balance

Audience and Purpose

Size, Scale and Media

Visual Balance

Elements of a Map n Map body n Legend n Title n Scale n North arrow n (inset map)

Other Elements of a Map n n n Source of data Map projection Author Date Neatline Graphs, tables, images, informative text n . . leading towards a poster

Who Made It? UTM? ? What is its name? Coordinates in DD Legend Where is it located (inset)? Border Where is north Neatline? What is the scale/ How accurate is it and where can you get it? • Credits. • How was it made. • Projection and Datum. • Other metadata

Map Templates

Layer Transparency

Labels and Annotation n . . more later today

Reference System n n n Graticule ºN/S, ºE/W Measured grid X, Y Reference grid 12 B or 14 G

Map Layout n Templates again

Map Scale n n The ratio of the distance between two points on the map and the distance between the same two points in the real world Describes distances and area sizes

Why Do We Care About Scale n n To compare or edge-match maps, they must be in the same GCS Remember, a GCS consists of: n n A metric An origin A projection A datum

Types of Scale n Graphical n Phrase (word(y) statement) n Representative fraction n Special cases n Variable scale

Graphical Scale n n Changes in map size(copy machine) preserve scale relationships Unit independent

Verbal Scale n n Does not preserve scale with size change Unit-dependant One inch equals one mile One to a a mile

Representative Fraction n n Does not preserve scale in size change Unit independent Ratio is true regardless of units Expressed as a ratio 1: 100, 000 Expressed as a fraction 1/100, 000

Variable Scale n n Projections that do not preserve distance City maps (Falk)

Large vs. Small Scale n Small scale shows large areas n n n Large denominator 1/500, 000 Think of it as small in detail Large scale shows small areas n n Small denominator 1/500 Think of it as large in detail

Area and Scale n n Retains the same relationship as linear scale The linear scale is squared 2 n 1: 1, 000 equals 1: 1, 000 n One square inch to one square mile

Examples of Scale

You Have to Decide n What is the intended use n How will it be used n How much detail n What are the units

Linear Units n Metric n n SAE n n Miles, yards, feet, inches Other n n Kilo-, centi-, milli-meters Degrees, chains, furlongs, rods, light-years Unit-less

Areal Units n Metric n n U. S. Public Land Survey n n Township, section, acre Other n n Hectare, decare, are City block, ZIP code, police district, parsec Unit-less

Convenient Fractions n Metric n n SAE n n 1 / 100, 000 or 1 cm equals 1 km 1 / 63, 360 or 1 inch equals 1 mile U. S. topographic maps n 1 / 24, 000 or 1 inch equals 2, 000 feet

Metric / SAE Conversion League Mile Furlong Chain 1 3 24 240 Rod Yard Foot Link Hand Inch Line 960 5280 15, 840 24, 000 47, 520 190, 100 2, 281, 000 Kilometer 4. 828 Meter 4, 828 Centimeter 482, 800 Millimeter 4, 828, 000

Beware of n 1 / 100, 000 does NOT mean n 1 mm equals 1 km, or 1 inch equals 100, 000 feet Mixed units n n Not allowed in representative fractions Permitted in verbal usage

Resolution n What is it that you wish to represent n n n Countries States Counties Towns Property ownership

Detail n n How much information needs to be conveyed? How precisely have objects to be mapped? n n Generalization Cartographic license

Cartographic License n Alteration of real-world spatial relations to better present pertinent information n Distortion n Combination n Shift n Exaggeration

How Much Detail?

Road Displacement

Generalization n 1: 5, 000 n 1: 10, 000