GEOG 1114 1stEdition Lecture 4 Outline of Last Lecture Physical Geography An Introduction to Earth III A portrait of the Earth continued 1 Earth movements 1 Seasons Summer Solstice Winter Solstice Fall Equinox Spring Equinox 2 Time Tropical year Lunar month Solar day Time zones Outline of Current Lecture Introduction to Maps The tools of Geography Maps Purpose Types Limitations Characteristics Map Scale Map Generalization Map projections Current Lecture What is a map It is spatial representation of phenomena What is a maps purpose They are used to convey information they help people understand spatial distributions and identifying patterns and teach one about size distance directions and understanding the layout of our planet Three Types of Maps 1 General Reference understanding of areas and a general idea of where things are 2 Thematic You can have whatever theme you want Ex Soil Moisture across the U S restaurant locations weather maps etc These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute 3 3 dimensional maps Google Earth but the best example is the globe it shows the true shapes of different parts of the world Google Earth distorts the image Map Limitations It is hard for a sphere to be portrayed on a two dimensional surface It took a whole decade to figure out how to draw a curvy line on a computer It requires knowledge of how to use cartographic skills and scientific visualization to produce an ideal map both in terms of interface and cartographic design Map Characteristics Scale the mathematical relationship between objects shown on the map and the real world Expression of scale 1 Fractional Map scale Representative Fraction a k a RF expressed as a ratio or fraction Ex 1 24 000 1 24 000 It is dimensionless meaning you put the units in 2 Graphic Map Scale depicts scale with a bar graph 3 Verbal Map Scale Ex 1 inch is equal to 1 mile Large vs Small Scale Fractional Relationship Small Scale shows a large area with small detail Smaller Representative Fraction larger denominator Large Scale shows small area with large detail Large Representative Fraction smaller denominator Map Generalization All maps show only a selection of geographic phenomena Generalization is influenced by the purpose of the map Three major techniques 1 Simplification 2 Classification and 3 Symbolization 1 Omitting details not essential to the purpose that will clutter and confuse 2 Ordering and grouping of data that reduces information to manageable forms 3 Graphic coding using small size shape colors of symbols for identification Projections A Systematic representation of all or part of the 3D earth surface onto 2D flat surface The Transform Process involves projecting the earth onto a simple geometric shape and flattening those shapes into two dimensional cylinders cones or planes
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