the geographer’s tools - tecs...

T H E G E O G R A P H E R ’ S T O O L S

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The Geographer’s Tools

HUMAN PERSPECTIVE. At noon on a sunny midsummer day, sometime, around 255

B.C., Eratosthenes drove a stake into the ground at the mouth of the Nile River in

Alexandria, Egypt. He then noted the angle of the shadow cast by the stake. Meanwhile

at Syene (modern-day Aswan, Egypt), another person drove a stake into the ground—

but it cast no shadow. Using the angle of the first shadow and the distance between Syene and

Alexandria, Eratosthenes calculated the circumference of the earth. By today’s measurements,

he was off by about 15 percent, but he was remarkably accurate considering the simple tools he

used. Eratosthenes was one of the earliest geographers to use tools and critical thinking to

measure and describe the earth. (Arreola, Deal, Petersen, & Sanders, 2003)

Geographers, in their quest to fully comprehend the dynamics of the earth’s surface,

answer the basic question for each of the five themes of geography (see previous chapter). To do

this, first, geographers collect information or data, perhaps, by conducting a census about a

target population, or use data collected by computers and satellites to come up with images

(aerial photographs and computer-generated graphics) of sections of the earth’s surface. Second,

geographers analyze the information they gathered by looking for spatial patterns and the

possible causes and consequences of such patterns. And third, they display information for other

Chapter

3

A [Source: Creationist.blogspot.com, 2008]

LESSON OBJECTIVES 1. Explain the advantages, functions, and types of maps. 2. Read maps appropriately by using the parts of a map. 3. Identify the time of selected locations using a time zone map. 4. Explain how GIS and GPS help geographers do their work. 5. Explain how models are used in the study of geographic places. 6. Discuss how geographers gather data through fieldwork.


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people to see and learn from in the form of maps, globes, diagrams, tables and graphs

(Williams, 2000).

GLOBES & MAPS (Williams, 2000). Globes are three-dimensional models of the earth.

When using the globe, consider the following pluses and minuses.

Advantages: “(1) most accurately represents the shape of the earth—shaped like a sphere; (2)

most accurately represents shapes of landmasses and bodies of water; (3) most accurately

represents parallels and meridians; (4) most accurately represents direction; and, (5) most

accurately represents distance—best tool to show the shortest distance between two places”.

Disadvantages: “(1) often not practical to use because it is expensive, big and bulky, and you

can view only one-half of a globe at a time; and (2) cannot show detailed features of an area”

\

Maps are flat representations of the earth. They are the product of cartography (the art

and science of making maps). These maps are collected in books that are called atlases, which

present details of places, countries, and continents. Just like the globe, the map has its

advantages and disadvantages:

Advantages. “(1) easier to use because it is easy to carry around—can be rolled or folded up,

provide an easy to use reference when collected into an atlas—collection of maps and related

material; (2) can show the earth’s entire surface or just a small part; (3) can show more detail;

and, (4) can present info about a wide range of topics—physical and cultural features”.

Disadvantage. “All maps have distortions (inaccuracies) because it is impossible to represent a

three-dimensional object like the earth accurately on flat maps. They do not all show areas of

the world in exactly the same way. This occurs because of the difficulty of showing the earth's

spherical (curved) surface on a flat map. Cartographers can take the information from a globe

and flatten the surface of the earth. They use different map projections—ways of showing the

round earth on a flat surface. However size, shape, and distance are distorted when curves

become straight lines.

The Globe’s latitudes (parallels) and longitudes (meridians)


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Uses of map. Professor Ulrich Freitag (1993) as quoted by Carter (undated) noted the four

variant functions of maps:

1. The cognitive function encompasses all processes and operations and all models, which

generate and enhance spatial knowledge. All processes of map analysis, transformations,

generalization, simulations, animations, etc. should be listed here, if possible in a sequence

of operations leading from near-reality models to very abstract models of space.

2. The communication function, which includes demonstration, encompasses all processes

and operations of spatial knowledge transfer from a mapmaker to a user. It may be divided

into several sub-functions according to the extent of transferred knowledge, the level of pre-

knowledge, the form and means of knowledge transfer. Educational communication, mass

media communication, academic communication, administrative communication represents

the dimensions of this function.

As a primary communicative device, a map may have the following uses ((Agno & Juanico,

1987):

a. To show the location of something on the earth either in a relative or absolute sense.

b. To show sizes and shapes of the earth features.

c. To reveal distances and directions between places or points on the earth’s surface.

d. To indicate elevation or slope.

e. To show distribution of physical and cultural features.

f. To visualize differences in places or areas and the patterns they create.

g. To allow inferences from data presented.

h. To show change—migration of people, exchange of goods and services, spread of

factories, etc.

3. The decision support function encompasses all processes and operations which -based on

the evaluation of spatial phenomena - result in spatial decisions and spatial actions.

Examples of these types of functions include navigation, planning, and persuasion.

4. The social function encompasses all processes which result not in spatial, but in social

behavior and actions. One form of this involves the professional mapmaker in relation to

other persons in the mapping process, including the users. Maps can also be seen as tools of

social power, exercised through the access or the denial of access to spatial information,

through copyrights or the monopoly on mapping equipment. Then there is the ability to

consider mapping as a cultural activity.

Map Types and Projections (Ludwig, n.d.)

A. Map Types. Maps can be divided into three main classes, or types. They are:

1. General Reference Maps. General reference maps are multi-purpose maps. Their

objective is to portray the spatial association of diverse geographical phenomena.

Basically, general reference maps show a great deal of information. They are extremely

useful in a variety of situations and they are the most common map type.


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Reference maps pay great attention to accuracy. Positional relationships of the

mapped features are extremely important on this type of map. The location of

roads, rivers, cities and other features are carefully plotted. In order to do this,

they may often show and label rivers and lakes, state and local boundaries. These

maps may also show roads, towns and cities, because we often use this

information as basic ways of orienting ourselves about where specific locations

are on the map. Examples are: Road Maps, Topographic Maps, Country Maps

2. Thematic Maps. Thematic maps are different from general reference maps in that they

focus on one topic or theme. The purpose of a thematic map is to show how this topic

changes or differs from place to place.

A thematic map is a special-purpose map, primarily portraying information on a

single topic or a set of topics. It may feature cultural information, such as

population, or physical information, such as annual rainfall. Examples are:

Census Map, Population Map, Weather Map, Agricultural Product Map

Positional accuracy, which is of the highest importance in reference maps, is less

important for a thematic map. It is more important for the map user to pay a great

deal of attention to what type of data was used to create the map and how the

data was mapped on a thematic map. Questions such as, "What is the source of

the data?", "What is the date the data was collected?", and "How was the data

divided into mappable units?" must be asked by the map user in order to insure

that the message the map is telling is accurate.

3. Charts. Maps designed for navigators are called charts. Simply put, maps are to be

looked at and charts are to be worked on. Routes are plotted, positions are determined,

bearings are marked on charts. Examples of a chart are: Nautical Chart, Aeronautical

Chart

Note: It needs to be emphasized that you can probably identify "pure" general reference

maps, thematic maps and charts, but in many cases maps combine functions. For example

the green printing on a topographic map shows the distribution of forested areas. Therefore

topographic maps, deemed a general reference map, can also be a thematic map showing the

distribution of forest areas in a region. Similarly, a thematic map can show political

boundaries, cities, or rivers so that the map user can easily fix locations of the subject

distribution.

B. Map Projections (EPA, 2017). Mapmakers have tried many ways to compensate for the

distortions that happen when drawing the surface of the earth. They have found many

mathematical techniques to convert and portray features from a spherical surface onto a flat

surface. Such a technique is called a map's projection. Map projections can be of three basic

types, or classes. These are:


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1. Conical projection is one in which the grid of hemisphere is transferred onto a tangent

cone and subsequently laid out flat as a map. The meridians of longitude appear as

straight lines and the parallels of latitude appear as parallel arcs.

2. Cylindrical Projection is one in which the geographical grid of the globe is transferred

onto a cylinder which encircles it. The cylinder is then cut and laid out as flat as a map,

assuming a rectangular outline of parallels and meridians, which are at right angles to

each other.

3. Planar/Azimuthal or Zenithal Projection indicates the correct direction of an area from a

designation point on the map. A portion or all of the globe is projected onto a map plane,

tangent to the globe at some point.

Cylindrical Projection of the World

Conical Projection of North America


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Reading a Map: Parts of a Map (Agno & Juanico, 1987) The parts of a map, which one

should usually look for in reading modern maps are:

1. TITLE. The title of the map tells briefly what the map is all about, i.e., its subject

matter, which could be the distribution of landforms all over the world or a map of

population densities of the 16 regions of the Philippines. The title aids in cataloging,

documentation and use in subsequent research.

2. LEGEND. The legend or key refers to the explanation of the symbols used in a map for

the physical and cultural features that are indicated.

3. SCALE. The scale is the relationship or ratio between a linear measurement on a map

and its corresponding true distance and compute area. There are three types of scales:

word/verbal scale (“one cm. equals one km.”); fractional (“1: 250, 000”); and

graphic/bar or linear (scale is indicated by means of graduated line)

4. LATITUDES & LONGITUDES. The latitudes and longitudes are the lines drawn by

convention over the earth’s surface in order to indicate direction and the location of an

area. They are parallels and meridians that intersect each other and are together referred

to as MAP GRID.

5. DIRECTION. Direction is indicated by some maps with a north arrow even if these do

not have lines. The north arrow can refer to either to the true (geographic) north or the

magnetic north. The true north is one, which is in complete alignment with the meridian

and points to the geographic North Pole through which the earth’s axis passes. The

magnetic north is one that is aligned with the flows of the magnetic force around a bar

magnet. This is the north indicated by the magnetic compass needle. The north magnetic

pole is located near Viscount Melville Sound north of Canada’s Prince of Wales Island.

Compass Rose. The compass rose shows you the north (N), south (S), east (E),

and west (W) directions on the map (Arreola, Deal, Petersen, & Sanders, 2003).

6. LABELS, SYMBOLS, COLORS. Labels are words or phrases that explain features on

the map. Symbols represent such items as capital cities, economic activities, or natural

resources. Colors represent a variety of information on a map (Arreola, Deal, Petersen,

& Sanders, 2003). Other maps may include the date of publication, publisher and the

cartographer.

Planar/Azimuthal Projection of the world [viewed from the North Pole]


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Maps and time zones. Before the late nineteenth century, time keeping was essentially a

local phenomenon. Each town would set their clocks according to the motions of the sun. Noon

was defined as the time when the sun would reach its maximum altitude above the horizon.

Cities and towns would assign a clockmaker to calibrate a town clock to these solar motions.

This town clock would then represent "official" time and the citizens would set their watches

and clocks accordingly.

In 1878, Canadian Sir Sanford Fleming suggested a system of worldwide time zones that

would simplify the keeping of time across the Earth. Fleming proposed that the globe be divided

into 24 time zones, each 15 degrees of longitude in width. Since the world rotates once every 24

hours on its axis and there are 360 degrees of longitude, each hour of Earth rotation represents

15 degrees of longitude.

In 1884, an International Prime Meridian Conference was held in Washington D.C. to adopt

the standardized method of time keeping and it determined the location of the Prime Meridian.

Conference members agreed that the longitude of Greenwich, England would become zero

degrees longitude and they established the 24 time zones relative to the Prime Meridian. It was

also proposed that the measurement of time on the Earth would be made relative to the

astronomical measurements at the Royal Observatory at Greenwich. This time standard was

called Greenwich Mean Time (GMT- former standard world time as measured at Greenwich,

England (location of the Prime Meridian), which was replaced in 1928 with Universal Time

(UT). Universal Time is commonly used to denote solar time.).

NOTE: International Date Line (IDL)—opposite the Prime Meridian, is used in marking

the passage of time or of one day as the earth rotates on its axis.

On the map in the left, how

many of the parts of a map can

you identify?

Source: San Diego North

Chamber of Commerce

[http://www.sdncc.com/communit

ies/] With modifications

http://www.geog.ouc.bc.ca/physgeog/physgeoglos/p.html#anchor882311

http://www.geog.ouc.bc.ca/physgeog/physgeoglos/u.html#anchor1977749


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Modern standard times zones as measured relative to Coordinated Universal Time. The numbers located at

the bottom indicate how many hours each zone is ahead (negative sign) or behind (positive sign) Coordinated

Universal Time. Some nations (for example, Australia and India) have offset their time zones by half an hour.

This situation is not shown on the illustration.

The 24 time zones relative to the prime meridian

http://www.geog.ouc.bc.ca/physgeog/physgeoglos/c.html#anchor107824

G E O G R A P H E R ’ S T O O L S

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GEOGRAPHIC INFORMATION SYSTEM (GIS) (Arreola, et.al, 2003)

GIS is the newest tool in the geographer’s toolbox. This system stores information

about the world in a digital database and it has the ability to combine information from a

variety of sources and display it in ways that allow the user to visualize the use of space in

different ways. The information gathered by GIS could include maps, aerial photographs, and

satellite images. The USGS (2007) defines the GIS as a computer system capable of capturing,

storing, analyzing, and displaying geographically referenced information; that is, data

identified according to location. Practitioners also define a GIS as including the procedures,

operating personnel, and spatial data that go into the system.

How does the Geographic Information System work?

Step 1: A question or problem is posed. Example: “In what general area near this town might

an airport be located?” A section of land is identified for problem solving.

Step 2: Computer databases hold geographic information about the location. Such information

is ready for use.

Step 3: The user selects layers of information that answer the question “What geographic

characteristics are important for a good airport site?”

Step 4: A terrain map is selected to identify all areas flat enough for landing airplanes.

A diagram showing how GIS works [Source: USGS. (2007). Geographic Information Systems.

http://erg.usgs.gov/isb/pubs/gis_poster/#how: ]

A diagram showing how GIS works [Source: USGS. (2007). Geographic Information Systems.

http://erg.usgs.gov/isb/pubs/gis_poster/#how]


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Step 5: A land use map shows areas that have few homes.

Step 6: The base map shows where roads are located so that the airport can be reached and

safety concerns are handled.

A terrain map showing the

physical features of a land

surface

Source: Hoffman, M. (2006).

Lost man maps.

http://www.3dnworld.com/user

s/83/images/buckhorn-b.jpg

A land use map showing

residential areas and areas

free of human settlements

Source: McClellan. (2004).

Interactive land use map.

http://www.mcclellan-

jpa.com/images/land_use_ma

p/mcclellan_land_use_map-

sm.jpg

A base map showing the road system

Source: Breckenridge.

(2007). Village base map.

http://breckenridge.snow.c

om/BreckBase/images/map

.basevillage.gif


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Step 7: The layers of information are combined to create a composite map showing possible

sites for the airport.

GPS-GLOBAL POSITIONING SYSTEM (GARMIN, 2017)

The Global Positioning System (GPS) is a satellite-based navigation system made up

of a network of 24 satellites. It was placed into orbit by the U.S. Department of Defense

(USDOD) originally intended for military use, but in the 1980s, the system was made

available for civilian use. GPS works in any weather conditions, anywhere in the world, 24

hours a day. There are no subscription fees or setup charges to use GPS.

How does the Global Positioning System work?

GPS satellites circle the earth twice a day in a very precise orbit and transmit signal

information to earth. GPS receivers take this information and use triangulation to calculate the

user's exact location. Essentially, the GPS receiver compares the time a signal was transmitted

by a satellite with the time it was received. The time difference tells the GPS receiver how far

A composite map showing

the possible sites

[darkened areas of the

map] for the project

Source: The Acaeum Library.

(no date). Module WGRX

Composite Map.

http://www.acaeum.com/librar

y/ivid_composite_map.gif

The 31 satellites that currently make up the GPS space

segment are orbiting the earth about 12,000 miles above

us. They are constantly moving, making two complete

orbits in less than 24 hours. These satellites are traveling

at speeds of roughly 7,000 miles an hour.


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away the satellite is. Now, with distance measurements from a few more satellites, the receiver

can determine the user's position and display it on the unit's electronic map.

MODELS IN GEOGRAPHY. A model is simply a representation of a real thing.

Geographers construct models to analyze geographic processes because the real object of

study may be too large to examine, the processes which created it operate over too long of a

time frame, or experimentation might actually harm or destroy it. For instance, physical

geographers use stream tables to investigate the impact of hydrological processes on the earth.

A stream table is more or less like a shallow sink filled with earth material similar to the land

surface of interest. Water is applied to the material to see what affect varying amounts of water

have on the erosion of the surface. Climate scientists use computer models, which are

elaborate mathematical models (Ritter, 2006)

THE VON THUNEN MODEL (Rosenberg, M., 2017)

Von Thunen model [From center

towards the outermost ring)

Center: City

1st ring: Intensive farming/dairying

2nd

ring: Forest

3rd

ring: Extensive field crops

4th

ring: Ranching/animal products

Soil Scientists examine model

of plots to investigate soil

erosion (Source: Ben Nichols,

U.S.D.A. Natural Resources

Conservation Service)

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The Von Thunen model of agricultural land use was created by farmer and amateur

economist J.H. Von Thunen (1783-1850) in 1826. The model was created before

industrialization.

Center of Von Thunen model is a city. There are four rings of agricultural activity

surrounding the city. Dairying and intensive farming occur in the ring closest to the city. Since

vegetables, fruit, milk and other dairy products must get to market quickly; they would be

produced close to the city.

Timber and firewood would be produced for fuel and building materials in the second

zone. Before industrialization (and coal power), wood was a very important fuel for heating

and cooking. Wood is very heavy and difficult to transport so it is located as close to the city

as possible.

The third zone consists of extensive fields crops such as grains for bread. Since grains

last longer than dairy products and are much lighter than fuel, reducing transport costs, they

can be located further from the city.

Ranching is located in the final ring surrounding the central city. Animals can be raised

far from the city because they are self-transporting. Animals can walk to the central city for

sale or for butchering. Beyond the fourth ring lies the unoccupied wilderness, which is too

great a distance from the central city for any type of agricultural product.

Even though the Von Thunen model was created in a time before factories, highways,

and even railroads, it is still an important model in geography. Of course, in the real world,

things don't happen as they would in a model.

Source:

http://mama.indstate.

edu/users/geboen/ch

7_thuneneur.jpg

With your

knowledge of the

physical and human

geography of Europe

today, what effects

would these

geographic elements

have on von

Thunen’s

hypothetical model

of agricultural land

use?

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FIELDWORK: SURVEYS AND OBSERVATIONS. Geographers also use questionnaires

as an indirect way of gathering information about spatial phenomena or they can also directly

involve themselves in participant observation as they investigate a particular area.

The different types of fieldwork activity in geography teaching are (Kent, et al., 1997):

Observational Fieldwork. The simplest and most traditional form of

observational fieldwork is the `Cook’s Tour’ or `look-see’ field visit. Students

often describe this type of activity as boring, since they are not deeply engaged

in the fieldwork process, but it can be useful at the start of a field course, to

give a first overview of an unfamiliar landscape. Carefully directed observation

can be a useful learning method, especially if reinforced by on-site tutorial-

style discussion.

Students become more engaged, typically, if the tour is on foot and they have

the opportunity to converse with staff, rather than being lectured. This format

allows students to make some observations independently and to follow up in

an informal way, issues they find interesting with staff.

Participatory Fieldwork. Participatory fieldwork has the reputation for

engaging student attention and deepening the learning experience. However,

this is not always true. Students are most dependent in staff-led project work. In

a typical staff-led project, the staff member decides on a project design and

allocates activities to the student participants. The methodology and mode of

analysis will usually be closely controlled. This can be a useful introduction to

participatory fieldwork, and is a fairly common format in the first year. The

format is also typical for a field day to support a laboratory-based course,

where students take samples in the field which will then be analyzed later

during practical/laboratory work.

Role-playing project work is an important variant of this approach. Competition

between groups may be a useful spur to achievement and may foster enterprise

skills. There can be high educational value in coming to terms with the

diversity of viewpoints arrived at by participants in a well-structured role-

playing exercise. In student-led group work, the student group will usually

formulate the research design and choose the methodology. The role of staff is

to encourage and to advise on health and safety.

Learner-practitioner and Participant Observation. In human geography and

the social sciences, participant observation is an alternative fieldwork format.

This can also have its place in physical geography. In human geography,

individual students join social groups and participate in their lifestyle. In

physical geography, students can, for example, take on the role of

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environmental manager or consultant, where it becomes known as learner

practitioner activity.

A variant of participant observation and learner practitioner activity—work

placement—is becoming increasingly common. Students are placed with

organizations—commercial companies, charities, government, local and

national environmental agencies and planning departments—and work as an

employee of the organization for a period of as little as one week up to a whole

year. This can be seen as a new and important format for fieldwork in

geography. Most students return from work placements as more mature and

responsible individuals. However, certain ethical issues may arise: it is vital

that the students are properly supervised and that they are not exploited as

cheap labor. Cooperative departmental research projects involving both

students and staff working together in teams to solve active research problems

are another development in this area and provide an analogue for the

apprenticeship situation.

Missouri State students use a total station during the Geospatial Sciences summer field

methods class. [Source: Missouri State University, http://geosciences.missouristate.edu/

40115.htm]

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