APHUG- CHAPTER 1: Maps and Geographic Data

Essential Question: What information is presented in different types of maps, and how to those maps show spatial patterns, the power of geographic data, and relationships among places?

Most important tool used by geographers?

Maps

How are maps essential?

Maps are essential as they help geographers organize complex information and effectively communicates spatial information. They also highlight and analyze patterns.

Political maps

They show/label human-created boundaries and designations (countries, cities, states and capitals)

Physical maps

Show and label natural features (mountains, rivers, deserts, etc)

Road maps

Show/label highways, streets, and alleys

Plat maps

Show/label property lines and details of land ownership

Thematic maps

Maps that show spatial aspects of information or of a phenomenon

Choropleth maps

• Maps that use various colors, shades of one color, or patterns to show the location/distribution of spatial data

• Frequently show rates other quantitative data in defined areas

Dot distribution maps

• Used to show the specific location and distribution of something across a map

• Each dot represents a specified quantity

• Other shapes may be used

Graduated symbol maps/Proportional symbol maps

• Use symbols of different sizes to show different amounts of something

• Larger sizes= more of something, smaller sizes= less of something

• Compare symbols to each other to see the largest.smallest of some event

• Symbols may overlap

Isoline maps/Isometric maps

• Use lines that connect points of equal value to depict variations in the data across space

• Lines close= rapid change, lines farther= phenomenon relatively the same

• Most common types are topographic maps and weather maps

Cartograms

• In cartograms the sizes of countries (or states, counties, other areal units…) are shown according to some specific statistic

• Any variable with statistics can be substituted for the size of a country

• Useful for data comparison/ distance and distribution is visible

Scale

Scale is the ratio between the size of things in the real world and the size of those same things on the map

Three types of scale

Cartographic scale, Geographic scale, Scale of data represented on the map

Cartographic scale

A cartographic scale refers to the way the map communicates the ratio of its size to the size of what it represents

Small Scale Maps

Show a larger amount of area with less detail

Large Scale Maps

Show a smaller amount of area with a greater amount of detail

Spatial patterns

Refer to the general arrangement of phenomena on a map

Absolute location

• the precise spot where something is according to a system

• Absolute location does not change

TWO global grid lines used to pinpoint absolute location

Latitude and Longitude

Latitude

The distance north or south of the equator

Equator

Imaginary line that circles the globe exactly halfway between the North and South Poles

Longitude

The distance east or west of the prime meridian

Prime Meridian

• Imaginary line that runs from pole to pole through Greenwich, England

• Designated at 0 degrees

International Date Line

• Follows a line of 180 degrees longitude

• Sometimes deviates to accommodate international boundaries

Relative location

• a description of where something are in relation to each other

• Described in terms of connectivity/accessibility

• Relative location can change as accessibility changes

Direction

• used to describe where things are in relation to each other

• Described with cardinal directions (north, south, east, and west)

Distance

A measurement of how far or near things are to one another

Absolute distance

Usually measured in feet, miles, meters, or kilometers

Relative distance

Indicates the degree of nearness based on time or money; dependent on mode of travel

Elevation

• The distance of features above sea level, usually measured in feet/meters

• Can impact climate, weather, agriculture, etc.

• Higher elevation=cooler temps

Distribution

The way a phenomenon is spread out over an area

Pattern

Patterns are the general arrangement of things

Clustered/agglomerated

arranged in a group/concentrated area

Linear

arranged in a straight line

Dispersed

Spread out over a large area

Circular

equally spaced from a central point forming a circle

Geometric

regular arrangement

Random

appears to have no order in their position

Why are all maps distorted

The earth is a sphere and all maps are flat

Map Projection

Show a curved surface on a flat surface

Mercator projection

designed for navigation because lines of directions are straight/easy to followP

Strength: Peter’s projection

Depicts the sizes of land masses accurately

Distortion: Conic projection

Not constant/ longitude lines converge at only one point

Distortions: Robinson projection

Area, Shape, Size, Direction