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Published by the Federal Democratic Republic of Ethiopia, Ministry of Education
Authors, Editors and Reviewers
Menur Hassen (M.Sc.)
Jember Tigabu (B.Ed.)
Hari Shankar Sharma (Ph.D., Professor)
Yirgalem Mahiteme (Ph.D.)
Nell Angelo (M.A.)
Evaluators
Haftu Araya
Tamrat Fitie
Yitagesu Demsie
Published by the Federal Democratic Republic of Ethiopia, Ministry of Education under GEQIP.
Copyrighted 2011 by the Federal Democratic Republic of Ethiopia, Ministry of Education.
All rights reserved.
Developed and Printed by STAR EDUCATIONAL BOOKS DISTRIBUTORS Pvt. Ltd. and ASTER NEGA PUBLISHING ENTERPRISE
Contents
Unit 1: THE CONCEPT OF GEOGRAPHY AND MAP-READING ………… 1
1.1 INTRODUCTION TO THE CONCEPT OF GEOGRAPHY ……………………………… 3
1.2 INTRODUCTION TO THE CONCEPT OF MAP READING ………………………….. 8
Unit Summary ……………………. 38
Review Exercise ………………… 39
Unit 2: PHYSICAL ENVIRONMENT OF THE WORLD AND ETHIOPIA ………….. 41
2.1 FORCES THAT CHANGE THE SURFACE OF THE EARTH ………………….. 42
2.2 WEATHER AND CLIMATE ………………… 65
2.3 NATURAL REGIONS OF THE EARTH……………………………………….. 91
2.4 ECOSYSTEM …………………………………….. 119
2.5 VILLAGIZATION OF THE WORLD THROUGH DISTANCE TIME DECAY… 123
Unit Summary ………………….. 126
Review Exercise …………………. 128
Unit 3: HUMAN POPULATION AND ECONOMIC ACTIVITIES .. 131
3.1 CONCEPT AND FACTS ABOUT HUMAN POPULATION …………………….. 132
3.2 ECONOMIC ACTIVITIES …………………. 148
3.3 NATURAL RESOURCES …………………….. 166
Unit Summary ………………….. 174
Review Exercise ………………… 176
Unit 4: PUBLIC AND POLICY RELATED ISSUES IN ETHIOPIA …………177
4.1 HIV/AIDS ………………………………………….. 178
4.2 ENVIRONMENTAL POLICY ……………… 184
4.3 ECONOMIC POLICY OF ETHIOPIA ………………………………………….. 191
Unit Summary …………………… 196
Review Exercise ………………… 197
Glossary ………………………………… 199
Unit Outcomes
After completing this unit, you will be able to:
recognize the concept, scope and branches of geography
express the meaning, historical development, uses and types of maps
compute field distance and areas of irregular shaped figures, construct and interpret statistical diagrams.
Main Contents
1.1 INTRODUCTION TO THE CONCEPT OF GEOGRAPHY
1.2 INTRODUCTION TO THE CONCEPT OF MAP-READING
Unit Summary
Review Exercise
Unit1 THE CONCEPT OF GEOGRAPHY AND MAP-READING
Introduction
In this unit, you will learn about the concept of geography and map reading.
The major topics to be covered include:
the meaning of geography,
scope of geography,
branches of geography,
what makes geography a science,
meaning of map,
historical development of maps,
uses of maps,
classification of maps,
magnetic declination,
linear and areal scales,
how to find the scale of a map,
measurement of regular and irregular shaped areas and statistical diagrams.
Geography, as a branch of knowledge, has been defined by different people.
The ancient Greeks and Romans defined it as the description of the earth.
The Germans in the 18th century defined it as a science that deals with the relationship between people and their environment.
In the mid 20th century, it became a spatial science dealing with the arrangement and distribution of things and phenomena over the surface of the earth.
The differences in these definitions reflect the fact that geography had various scopes during its historical development.
Initially it was considered as a general earth science;
geography has now become a science that examines “place and space” on the Earth’s surface in relation to location, distribution, arrangement, interaction, causes and effects of (things and) phenomena.
Modern geography is a spatial temporal-areal science.
Nowadays, geography has two main branches of study - physical and human.
The most important tools that geographers use are maps.
Like the science of geography itself, maps have evolved over the centuries.
They have changed from simple sketches to complex representations such as spatial data compilations, which you will study in later grades.
Start-up Activity Examine carefully Figure 1.1 and try to understand their linkage with the subject Geography.
Introduction To The Concept Of Geography
At the end of this section, you will be able to:
define the term geography;
describe the development of geography as a discipline;
determine the scope of geography;
identify the branches of geography; and
identify the characteristics that make the subject of geography a science.
Key Terms
Spatial
Geography
Scope
Development
Science
Meaning of Geography
What is geography?
Do you think that geography has a single universally accepted definition?
Why?
From the ancient Greeks to modern-day geographers, geography has been defined differently.
However, the various definitions share some common ideas.
Here are some of the most important definitions that geographers have proposed:
Eratosthenes (276-196 BC) – Geography is the description of the earth.
Concise Oxford Dictionary (1964) – Geography is the science of the earth’s surfaces.
Hartshorne, R. (1899-1992) – Geography is a branch of knowledge that is concerned with the provision of an accurate, orderly and rational description of distributions on the surface of the earth.
Yeates, M. (1968) – Geography is a science that is concerned with the rational development and testing of theories that explain and predict the spatial distribution and locations of (things and) phenomena on the surface of the earth.
As you can see, each of these definitions includes the idea that geography studies the earth.
Most of them specify the surface of the earth.
At this level, we will define geography as a branch of science that studies the earth’s surface and the distribution, arrangement and interaction of natural and human features and their causes and effects.
The Scope of Geography
What is scope?
How wide is geography’s scope?
Scope means the range and variety of contents which are included in a subject or field of study.
Geography’s scope is very wide.
As the scope is dynamic, it changes often as new discoveries and ideas enter the field.
Geography studies a great many physical and human features of the world.
Its focus includes their causes, effects, and interactions.
As indicated above, the subjects that geography examines include features in the hydrosphere, atmosphere, lithosphere and biosphere.
Geography has undergone profound changes in its scope and focus:
In ancient times, geography was considered to be the mother of many other sciences, including philosophy and the earth sciences.
In the 16th century, geography began to emphasize location, focusing on questions of where, why and what.
In the mid 18th century, European geographers, especially Germans, considered the relationship between geography with philosophy. This approach caused geography to focus on the relationship between human and the natural environment. Alexander Von Humboldt and Carl Ritter were among the major contributors to this approach.
In the 19th century, geographical societies and research groups formed. They enhanced the role of geography as a discipline.
In the late 20th century, geography became a spatial science.
Note
The earth’s surface consists of:
hydrosphere – It includes all the bodies of water, i.e., oceans, rivers, lakes and others.
biosphere – This refers to all living organisms in and on the earth’s surface.
atmosphere – It includes all aspects of air composition surrounding our planet.
lithosphere – It is the solid layer of rocks which covers the entire surface of the planet.
Branches of Geography
What are the two branches of geography?
Can you list some of the fields of geography that fall into each of the two branches?
You have studied the definition of geography, and you have considered its scope.
Next you will learn about the main parts of geography – its branches.
They are:
Physical geography
Human geography
i Physical Geography: This branch of geography studies the distribution of the natural features of the world, such as climate, landforms, soil, vegetation, and drainage systems.
Physical geography also considers causes, effects and interactions of these features.
Physical geography includes the following specialized fields of study:
Climatology:
studies factors that create climate and examines the variation and distribution of climate and related causes and effects.
Geomorphology:
studies the distribution of landforms (such as mountains and plains) and the forces that change them.
Soil geography:
studies the distribution of soils and their characteristics.
ii Human Geography: This branch of geography studies the distribution and influence of human aspects of our world, including cultures, population settlement, economic activities and political systems.
Human geography includes these specialized fields of study:
Cultural geography:
studies the distribution and interactions of cultures, including peoples’ beliefs and customs. It also examines the movement, expansion and interaction of cultures on the surface of the earth.
Population geography:
studies the distribution, growth and structure of population.
Economic geography:
studies production, consumption and exchange and the spatial distribution of goods and services and factors affecting them.
Political geography:
studies the distribution of political systems and the ways people use them to exercise power and make decisions.
Urban geography:
studies the development and characteristics of towns, cities and other urban centers.
Historical geography:
is the study of the geography of the past and how places or regions change over time.
Geography as a Science
What is science?
What makes geography a science?
Science is a system of acquiring knowledge through scientific methods.
These methods involve observation, identification, description, experimental investigation, and theoretical explanation of phenomena.
Geography investigates facts and relationships related to physical and social phenomena, and examines their distribution across the world and changes over time.
The main tools geography uses to gather and analyze information are observation, systematic description, systematic recording and mapping.
As you can see from its subject matter and methodologies, geography is a subject that bridges the natural and social sciences.
Introduction To The Concept Of Map-Reading
At the end of this section, you will be able to:
explain the meaning of a map;
appreciate the historical development of maps;
state the basic uses of maps;
categorise maps based on scales and purposes;
distinguish the conventional signs and symbols used to represent different features on maps;
identify some of the marginal information given on maps;
convert linear scale to areal scale;
calculate the scale of a map;
calculate the areas of regular and irregular shaped figures by referring to the scale of a map;
construct statistical diagrams using simple line graphs, bar graphs and pie charts based on the provided data.
Key Terms
Latitude
International Grid Reference (IGR)
National Grid Reference (NGR)
Magnetic declination
Remote sensing
Global Positioning System (GPS)
Geographical Information System (GIS)
Longitude
Meaning of Map
What is a map?
Do you remember what you have learned in previous grades about map?
Here is a simple definition:
A map is a simplified, diminished, plain representation of all or part of the earth’s surface as viewed from vertically above.
Here are the main features of maps:
A map represents all or part of the earth’s surface. For example, a map might show a city such as Addis Ababa, the entire world, or a section of a garden.
A map is a two-dimensional (plane) representation. For example, a map might be printed on a piece of paper.
Maps show the earth’s surface as if it were seen from directly above. This view is called a bird’s-eye view.
All maps are smaller than the area they represent.
Maps are drawn to scale. In other words, the features shown on a map have the same relative proportions as they do in reality. For example, if one mountain’s diameter is twice as large as that of another mountain, the first mountain would be shown on a map as twice as large as the second.
Maps are simplified representations.
Most maps use generally accepted symbols to represent natural, artificial or cultural features of the area they represent. They also use conventional notations to provide background information such as the map’s title, date and scale.
Historical Development of Maps
Describe the historical development of maps.
How do traditional and modern map-making differ from each other?
Maps are among our oldest tools.
People created maps even in primitive times.
For instance, men and women sketched their routes to hunting, fishing and gathering grounds.
Today, we also prepare maps, for many purposes.
However, map-making has passed through many stages of development since its beginning.
The two main stages of the historical development of map-making are:
Traditional map-making
Modern map-making
A Traditional map-making
What are the major features of traditional map-making?
How did people represent the environment on maps in the past?
The art of traditional map-making is as old as the human race.
Traditional maps have been made in many ways.
For example, early map materials included sticks, shells, clay tablets, parchment, paper and solid plates of silver.
Many traditional maps were locational.
For example, they have shown the locations of water holes and hunting grounds and have included paths that led to these places.
Another main difference between traditional and modern maps is that a traditional map might include drawings of three-dimensional objects.
As a result, a traditional map might be somewhat pictographic (or physiographic) rather than strictly diagrammatic.
Most traditional maps are sketch maps.
B Modern map-making
When did modern map-making start?
What features characterize modern map-making?
What is the role of GIS in modern map-making?
The modern science of map-making has its basis in the 17th century.
The various developments that took place during the Renaissance gave way to accurate map- making (cartography).
Furthermore, advancements in science and technology resulted in the invention of better cameras and airplanes specially designed to take aerial photographs.
Today, map-makers have diverse opportunities to acquire spatial information.
In addition to aerial photography, satellite imagery provides a wealth of information.
Nowadays, computers have come to be “close friends” of map-makers.
This is because they have become invaluable in making maps.
In the last three decades of the 20th century computers have been seen as integral part at almost every stage of the cartographic process.
They play roles in the collection, storage, analysis, and presentation of data, and even in the mapping and reproduction of maps.
This makes the Geographic Information System (GIS) indispensable to modern map-making.
A GIS needs a geographic database of, for example, a digital record of geographic information.
The first step in developing a GIS is to create the geographic database from such sources as maps, field surveys, aerial photographs, satellite imagery, and so forth.
Generally, modern map-making is fast and uses modern ways and means of collecting information, such as specially designed airplanes, remote sensors and the Global Positioning System (GPS).
Uses of Maps
Why are maps very important in geography?
What are the major uses of maps?
As you know, the map is geography’s most important tool.
It is also one of the most flexible tools in terms of the information it presents and the uses we can make of it.
For example, it can present very simple information or highly detailed results from a complicated geographical investigation.
Maps are basically used for identifying locations, distance, area and direction.
Location: With the help of a map it is possible to locate a place in reference to another place. For example, Ethiopia’s location can be expressed in terms of its neighboring countries, external land masses and water bodies.
It is also possible to locate a place using astronomical grid references – parallels and meridians. For example, the absolute location of Ethiopia is 3^oN-15^oN latitude and 33^oE-48^oE longitude.
Distance: It is possible to calculate the distance between two or more places on a map. This is done by using the scale of the map. For example, the air distance between Bahir Dar and Addis Ababa can be calculated by using a map of Ethiopia.
Area: The area of a place, a country, a region, a continent, a sub-continent or the whole world can be calculated from a map. This is done by measuring the length and the width of the given place on the map and by converting them to ground distances with the help of the scale of the map.
Direction: A map can enable us to identify the direction and bearing of any place on the map. This is accomplished by referring to another place. For example, a map of Ethiopia can help us to find the direction and bearing of Mekele by referring to Addis Ababa.
In addition to these, maps can be used to:
Show the distribution of physical and human phenomena on the earth’s surface: distribution maps show the locations of phenomena on the earth’s surface. For example, we use distribution maps for Ethiopia to show the presence of human and animal populations, minerals, and vegetation. Similarly, we use distribution maps to show patterns of settlement, temperature, and health conditions.
Show surface configuration: topographic maps give information about variations in height on the earth’s surface. For example, they show heights and depths of valleys, plains and mountains.
Offer visual comparisons: because the earth’s surface is vast, it is difficult to compare places by direct observation. For example, it would be difficult to compare the distribution of landforms in Ethiopia and Kenya, even from an airplane. However, by offering us relatively small but accurate representations of the two countries, maps solve this problem completely.
Support development planning: Maps can provide planners with vital information to plan for the future. For example, maps can show current conditions and ongoing trends, and they can help us predict a nation’s socioeconomic conditions. Such information is invaluable to the country’s planners as they analyze possibilities and livelihoods and then prepare for the future.
Classification of Maps
How many types of maps do you know?
Do you think that all maps are one and the same?
Why?
Although most maps have similar characteristics, they can differ from one another in many ways.
This topic teaches you how to classify maps in terms of the following features:
Focus and level of detail (purpose) – the amount of information they present about their subjects, especially their ability to show small details.
Scale – the size of the area for which they give information and, therefore, the scope of the information that they give about these areas.
Classification Based on Purpose:
Maps can be classified as general-purpose or specific-purpose.
General-Purpose Maps
What are general-purpose maps?
What are they used for?
List uses of topographic maps.
A general-purpose map is a map that shows the features of a place in a relatively general way.
It provides a wide range of information about the place it represents.
General-purpose maps are not topical.
Instead, they tend to contain a little of many kinds of information at a relatively low level of detail.
Topographic information of each kind in lesser detail. A topographic map is a good example of this. It can illustrate both physical and human-made features of the earth.
Specific−Purpose Maps
What kind of map is a specific-purpose map?
How does it differ from a general- purpose map?
Specific-purpose maps are often called thematic maps or topical maps.
We use these terms because specific-purpose maps emphasize on a single topic.
These maps show detailed information about their subjects.
Thematic maps can show almost any kind of information that varies from place to place, such as population distribution, rainfall and temperature patterns, and the distribution of types of soil or vegetation.
Soil maps
Vegetation maps
Climate maps
Classification by Scale
Scale is a ratio that shows the degree to which the area that is mapped has been reduced.
Based on scale differences, maps can be classified into:
Large-scale maps
Medium-scale maps
Small-scale maps
Let us now consider each of these types of map in more detail.
Large-Scale Maps ≥ 1:50,000
What are large scale maps?
Large-scale maps present small areas in detail with great accuracy.
Large-scales are greater than or equal to 1:50,000.
A large-scale map, such as the map of Addis Ababa, shows the city in considerable detail.
Large scale maps present a relatively small area and show its features in considerable detail.
For example, at a scale of 1:5,000, a map of a city can include many features – such as buildings.
The map can also include many details, such as the bends in highways.
Medium-Scale Maps 1:50,000 - 1:250,000
What are medium-scale maps?
These are maps that are prepared with scales that range between 1:50,000 and 1:250,000.
Medium-scale maps cover wider areas than large scale maps, but cover smaller areas than small-scale maps.
They are also able to present more detailed information than small-scale maps but are less detailed than large-scale ones.
Small-Scale Maps ≤ 1:250,000
What are small-scale maps?
Small-scale maps are those which are prepared with scales less than or equal to 1:250,000.
These small–scale maps cover wider areas than large and medium scale maps.
Marginal Information of Maps
What is a map’s margin?
What are the most common types of information that are found in the margin of a map?
Maps are used to convey information.
To read maps effectively, map users need information about the map.
Such information is presented in the map’s margins and is known as marginal information.
Marginal information includes:
Title of the map: Gives the map’s name. For example, “Soil Map” explains that the map presents information about soil.
Year of publication: identifies the year in which the map was published. Because this information tells you how old the map is, you might be able to judge whether the map’s contents are current or might be out of date.
Author: identifies the copyright owner of the map and indicates who (or what organization) has prepared the map.
Place of publication and publisher: tells where the map was published and identifies the organization that published the map.
Scale: This information indicates the extent to which the area that is represented in the map has been reduced.
Legend/Key: explains the meaning of the signs and symbols used in the map.
Type of projection: tells the kind of projection used in making the map.
Direction or orientation (North) arrow: Shows the north direction on the map.
The magnetic declination (variation): is the difference between Magnetic North and True North. This will be explained later in this unit.
Conventional Signs and Symbols
How do maps show different features of the earth?
What do map-makers use to represent the different physical and human features on maps?
Geographers have developed a standard set of symbols and other graphic conventional signs to represent features shown on maps.
Conventional signs and symbols are those signs and symbols that are used on maps through the agreement of all map-makers of the world.
They are used to represent the same detail on a map in all the countries of the world.
Signs and symbols help the map reader to understand maps.
Therefore, the map reader has to look first at the key or legend of the map. When you create a map, the symbols you select should satisfy the following requirements.
They should be uniform throughout the map.
They should be easy to read and understand.
The space occupation, orientation and size of the symbols should be constant.
Here are some of the symbols and conventional signs that are widely used and understood worldwide:
cities and towns are indicated by dots or patches of shading;
streams and bodies of water are often printed in blue; and
political boundaries are shown by dot lines/solid lines.
Map Scale
What is map scale?
Why do we need map scales?
The scale of a map is the ratio between the measurement of distance on the map and the corresponding measurement on the earth’s surface.
For instance, the ratio of the map distance between two cities on a map and the actual distance between the two corresponding cities on the earth is the scale to which that map is drawn.
Grid References
What is a grid reference?
Why is it important?
What is the difference between a geographic grid and a national grid reference?
A map grid is a set of imaginary lines that divides the earth’s surface into regular grids.
There are two major map grid systems:
International (Geographic) Grid System
National Grid System
The International (Geographic) Grid System shows the absolute locations of places on the surface of the earth. Its references are made up of:
* parallels or lines of latitude – define locations north and south of the equator. They are horizontal lines of the grid.
* meridians or lines of longitude – define locations east and west of an imaginary north-south map line called the Prime Meridian. They are vertical lines of the grid.
Latitude: When looking at a map, latitude lines run horizontally. Lines of latitude are also known as parallels since they are parallel and are an equal distant from each other.
Each degree of latitude is approximately 111 km apart. Degrees of latitude are numbered from 0° to 90° north and south. Zero degree is the equator, the imaginary line which divides our planet into the northern and southern hemispheres. 90° north is the North Pole and 90° south is the South Pole.
Longitude: The vertical lines of longitude are also known as meridians. They converge at the poles and are widest at the equator (about 111 km apart).
Zero degrees longitude is located at Greenwich (0°). The degrees continue 180° east and 180° west where they meet and form the International Date Line in the Pacific Ocean.
Parallels and meridians are imaginary lines.
Latitudes are angular distances measured to the north and south of the equator in degrees, minutes and seconds. Longitudes are also angular distances, but they are measured to the east and west of the Greenwich meridian.
The National Grid Systems: is used on maps of individual countries and regions within them. Its references differ from those of the International (Geographic) Grid System.
The National Grid System uses eastings and northings. Eastings are lines that are drawn from north to south. Northings are lines that are drawn from east to west.
Eastings and northings in the National Grid System originate from the “False Grid Origin” that lies at the southwestern corner of the place they cover. While the values of eastings increase eastwards, the values of northings increase northwards. Eastings and northings are measured in kilometers.
In Ethiopia, there are two ways of giving national grid reference. They are four- digit and six-digit grid reference.
Eastings are always given before northings. For example, the six-digit grid reference of letter A is 490970.
Magnetic Declination
What is magnetic declination?
What is magnetic north?
What about true north?
The earth has north and south geographic poles at the northern and southern convergence points of the meridians.
It also has north and south magnetic poles.
Magnetic compasses that are used in navigation point towards the north magnetic pole, rather than the geographic North Pole.
Magnetic declination is the difference between magnetic north and true north.
It is the angle between magnetic north and true north from a particular point on the earth’s surface.
The position of the north magnetic pole moves over time.
Therefore, the declination factor must be updated from time to time.
However, a relatively new navigation device, the gyrocompass, is adjusted so that it points to the geographic North Pole directly that it does not need this compensating factor.
The amount, direction, and annual change of the variation for most localities on the surface of the earth has been determined, and this data is recorded.
The Relationship Between Linear and Areal Scale
What is linear scale?
What about areal scale?
Is it possible to convert one into the other?
How?
Map scale can be linear or areal.
Linear scale expresses the ratio of map distance to ground distance.
It is the most common scale type.
Areal scale shows the relationship between map area and ground area.
Areal scale is the square of linear scale.
For example, if a map has a linear scale of 1 cm to 6 km, then the areal scale of the map is (1 cm)^2 to (6 km)^2, which means 1 cm^2 to 36 km^2 .
To calculate linear scale from areal scale, you put the areal scale into a square root.
For instance, if the areal scale of a map is 1 cm^2 to 36 km^2, then the linear scale of the map is the square root of the given areal scale, as shown below.
Areal Scale = (Linear Scale)^2 = (\frac{Distance on the map}{Distance on the Ground})^2
Linear Scale = \sqrt{Areal scale}= \sqrt{\frac{Map Area}{Ground Area}} = \sqrt{\frac{1 cm^2}{36 km^2}}= 1 cm to 6 km
How to Find the Scale of a Map
Is it possible to calculate the scale of a map when it is not given?
How?
In principle, every map should show the scale to which it has been drawn.
If the scale is not shown, we can calculate it.
There are two ways of finding a map scale, if it is not given:
By using the known distance between two points on the map
By using latitudes
A By using the known distance between two points on the map
This method is used if the ground distance between two points or places shown on the map is given.
Then use the following procedure to obtain the scale:
Measure the distance between the two points on the map in centimeters.
Divide the obtained distance on the map by the ground distance to obtain the ratio between the two. This gives you the scale of the map.
Scale = Ground distance \div Distance measured on the map
B By using latitudes
In this method, the scale of the map can be obtained by using the values of latitudes.
Scale =\frac{Distance on the Map}{Ground Distance}
1° latitude is about 111 km
This relationship is derived from the circumference of the earth – 40,000 km
If 360° = 40,000 km
1° = ?
= 111 km $$
The Measurement of Regular and Irregular Shaped Areas