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DRAFT Geographer’s Toolbox class notes/study guide, Scott Phillips
GEOGRAPHER’S TOOLBOX EXAM 1 (MIDTERM) STUDY GUIDE
NOTE: Not everything on exam is covered on study guide. Additional material is covered in assigned readings:
http://sanjoaquinvalley.org/geography/comment/65#comment-65
The Science of Geography
Geography as a discipline and profession
Geography is a science concerned with space and spatial relationships
 The extent of where features exist
 Arrangement of features in space
 Often called the spatial science for this reason
This is true not just for physical geography but other types of geography as well (human geography,
economic geography, political geography, biogeography, etc…)
Uses spatial analysis as its method
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Maps
o The science of map-making is called cartography
Geographic information systems (GIS)
o Combines cartography (maps) and databases.
Remote sensing
o The ability to “see” the earth using sensors on airplanes or satellites
 Provide rapid, worldwide view of the environment
 Can view places that are difficult to travel to in person
 Can measure and locate natural resources
Models – models are a useful simplification of reality and include parts of the above items
o Maps and globes
o Remote sensing images
o Conceptual models – how we picture “systems” in action
 Rivers, weather, climates, vegetation, etc…
o Mental maps – conceptual models that are ideas in our heads
 How you get to school, how you get around your house
The Spatial Science Perspective
Location
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Absolute location – precise mathematical location (latitude and longitude)
o 36.5 degrees north, 120.25 degrees west
Relative location – where something is in relation to another place
o 10 miles north of downtown Merced
Place
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Places are more than their mathematical, or absolute location
o Have names, like children and pets
Region
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An area on the earth that shares some characteristics
o Climate region, language region, vegetation region
Spatial distribution and spatial patterns
 Distribution – extent of area where a feature exists
 Pattern – arrangement of features in space
Spatial interactions
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A condition or occurrence in one place has impacts on other places
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DRAFT Geographer’s Toolbox class notes/study guide, Scott Phillips
Location and Time on Earth
Latitude and Longitude
Latitude – measurement of (angular) distance north or south of the equator (to the poles)
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Latitude increases from the equator to the north pole or south pole
o These are the two fixed reference points for the Earth
 Is strongly related to yearly patterns, like sunlight and seasons
 Lines are called parallels
Longitude – measure of (angular) distance east or west of a point on the Earth’s surface
 Longitude is measured as east and west from Greenwich, England for historical reasons
 Is strongly related to 24-hour cycles like the time in any given location
 Lines are called meridians
Latitude and longitude are measured and subdivided, like time:
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Degrees, minutes, and seconds (each degree is about 69 miles)
o Latitude goes from 90 degrees north to 90 degrees south
o Longitude goes from 0 degrees to 180 degrees (east or west)
Minutes – There are 60 minutes in each degree (like the minutes of an hour)
Seconds – There are 60 seconds in each minute (like time also)
Lines on Earth (Latitudes) Delimiting Solar Energy (from north to south)
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Arctic Circle (66.5 degrees north
Tropic of Cancer (23.5 degrees north)
Equator (0 degrees)
Tropic of Capricorn (23.5 degrees south)
Anarchic Circle (66.5 degrees south)
Public Land Survey System (PLSS)
Reference system used to divide property in the western US
Land is divided into 36 square mile (6x6) townships
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Referenced by their township (north-south) and
range (east-west)
Each township has 36 one-mile square sections
Sections (640 acres) can be subdivided into smaller
parts
Maps and Digital Mapping
Map Projections
Because latitude and longitude are angular distances (think circles on a globe!),
are not ideal for looking at the earth as a flat surface.
they
So why do we want to look at the Earth as a flat surface?
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So we can use geometry to measure areas of regions, distance
between locations, etc…
Notes about Map Projections:
All map projections distort one or more properties of a map including: Distance, Direction, Which properties are
distorted depends on the map projection.
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DRAFT Geographer’s Toolbox class notes/study guide, Scott Phillips
There are many types of map projections and I don’t expect you to remember all
of these in detail, but for the sake of understanding the concept, remember this
one:
Universal Transverse Mercator (UTM)
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The earth is divided into zones that run north and south
Each zone acts as a flat grid with geometric coordinates
o X coordinate (east-west) is measured from the edge of the
zone (or just beyond it actually)
o Y coordinate (north-south) is measured from the equator to
the north pole, or from the equator to the south pole
o
Map Scales
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How much area is covered by a map at one time
There is a trade-off between scales
o The amount of area that is covered
o The amount of detail that is shown
 Think of the zoom feature on a camera
Is described by a representative fraction
o 1:24,000
 Or, one inch equals 24,000 inches
o 1:100,000
 Or, one cm equals 100,000 cm
o Think about this like if you were building a scale model of a house or model car
 A ¼ scale model would have a representative fraction of 1:4
In geography, a large-scale map is “zoomed in”
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Remember that the representative fraction is relatively large (like 1:5,000 =
o
And the fraction
o Covers a small amount of area
o Has greater detail
A small scale map is “zoomed out”
o
Remember that the representative fraction is relatively small (like 1:5,000,000 =
o
And the fraction
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Covers more area, but in less detail
Types of Maps:
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General maps – tell you where you are
o Think Google Maps or a road atlas
Thematic maps – convey information
o Like a climate map, or a soil map
 Discrete data – is in categories
 State boundaries show discrete location
 Continuous data – is varying amounts of something
 Weather maps show continuous information
Contour maps (topographic maps) – show lines of equal elevation
o Topographic maps have lines that connect points of equal elevation
o Tells you how flat or hilly an area is (the “lay of the land”)
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DRAFT Geographer’s Toolbox class notes/study guide, Scott Phillips
Remote Sensing and Air Photo Interpretation
Remote Sensing
Science and art of obtaining information about an object without being in contact with it.
Different then in situ, or field-based measurements.
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Information collected from a distance
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Satellites
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Airplanes
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Other (balloons, kites, sticks with sensors)
Visible light
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The kind of light we see
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Goes from blues to reds
Infrared light
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“farther than red” light we can’t see
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But we can use sensors to measure it
Airphoto Interpretation
Uses film photography – a type of remote sensing.
Film has limitations – cannot be beamed back from space and can’t capture as much of the electromagnetic
spectrum (see below) as digital images can.
Types of airphotos
Vertical - Straight down
Oblique - Taken at angle
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High oblique – Can see horizon
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Low oblique – No horizon
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Elements of airphoto interpretation
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Recognition elements: Shape, Size, Shadow, Pattern, Tone or Color, Texture, Height/Depth,
Association or Context
Photo-interpretation keys
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Selective keys: Illustrations, descriptions of objects, Analyst picks the closest one
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Elimination keys: Step by step from general to specific, Dichotomous elimination
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Analyst must pick between two choices at each step
Remote sensing and Electro-Magnetic Radiation (EMR)
Shortwave radiation (from the sun)
Higher-powered energy from the sun is called shortwave radiation.
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The shorter the wavelength, the more powerful the energy
o X-rays have very short wavelengths and are very powerful and potentially harmful
The visible wavelengths are that part of the spectrum that we see with our eyes
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Ranges from violet/blue to red (like a rainbow)
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DRAFT Geographer’s Toolbox class notes/study guide, Scott Phillips
Infrared (or “less than red”) are the part of the spectrum with longer wavelengths than the color red
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Near infrared is part of the shortwave radiation from the sun
o We don’t see it with our eyes but plants reflect near infrared very strongly
o In remote sensing, satellites measure near-infrared to map where plants are
 We usually display it using the color red (which we can see)
 Called a “false-color” image
Longwave radiation (or heat, from the Earth)
Middle or far infrared is less powerful energy that is basically heat energy. It is reflected back to space from the
Earth. It also includes some very long wavelengths we use like:
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Microwaves, TV and radio signals, mobile phone signals, radar
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GIS systems combine spatial and attribute data
o Combine Cartography and Databases
Maps can contain multiple data layers of features:
o Physical features
o Cultural features
Layers can be added to create composite overlay
GIS
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Types of GIS data
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Vector (geometry)
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Points
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Lines (polylines)
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Polygons
Raster (grid), Basic component is a “Cell” or “Pixel”.
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Array, or grid of “pixels” or cells like a digital photo
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Have number values associated with each cell
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Data is stored in a database – each geographic feature goes along with one attribute (tabular) record
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You can query (ask questions) different ways:
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Attribute query – Selecting by attribute (tabular or database) values
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Location query – Selecting by map features – where things are located
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Must specify location relationship: Is something near, adjacent to, intersecting, or inside?
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Overlay operation – Combining layers to create a new layer
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Buffer operation – Creating a new layer that is within a certain distance of an existing one.
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DRAFT Geographer’s Toolbox class notes/study guide, Scott Phillips
SOLVING INTERNATIONAL TIME PROBLEMS
There will be some additional problems where you need to solve problems related to time and longitude.
There are a few things you should
remember:
How many degrees (longitude) is
it all the way around the Earth?
(180 degrees west + 180 degrees
east = 360 degrees total)
How many hours are in a day?
(24)
So that means that the Earth turns
15 degrees each hour.
Another way of putting this is the
location on the earth where the sun
is directly overhead moves about 15
degrees of longitude each hour.
That is why time zones are about 15
minutes of longitude away from
each other.
Another thing to remember is:
It is later in the day s you go East
(to the right on a map)
It is earlier in the day as you go
West (to the lef on a map)
This is because the earth is turning so that things are always moving towards the east
(think of sunrise and sunset). If you forget, remember that East coast channels show
TV shows earlier because it is later on the East coast.
So in other words:
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It is going to be one hour later for every 15 degrees of longitude east.
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It is going to be one hour earlier for every 15 degrees of longitude west.
So if it is 12:00PM at 0 degrees longitude:
What time is it at 15 degrees east longitude? (01:00 PM)
What time is it at 45 degrees east longitude? (03:00 PM)
What time is it at 15 degrees west longitude? (11:00 AM)
What time is it at 45 degrees west longitude? (09:00 AM)
Before sailors had modern technology like GPS, they developed a system of telling
longitude comparing the time on a clock set back home with the time where they were (by looking at the sun).
For example, if you sailed from the prime meridian (0 degrees longitude) at 12:00 PM (and set your clock to 12:00
PM.), you could look at that clock later when it was high noon (at your location) and see what time it is back home:
What is your longitude if your clock read 01:00 PM (15 degrees west longitude)
What is your longitude if your clock read 03:00 PM (45 degrees west longitude)
What is your longitude if your clock read 11:00 AM (15 degrees east longitude)
What is your longitude if your clock read 09:00 AM (45 degrees east longitude)
This can be confusing because the clock is telling you the time back home, not where you are.
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