Geography Grade 10 Notes
GEOGRAPHY NOTE FOR GRADE 10
UNIT 7: GEOGRAPHIC ISSUES AND PUBLIC CONCERNS IN AFRICA
7.1 Unplanned Urbanization
Urbanization: Population shift from rural to urban areas, decreasing the proportion of people in rural areas.
Growth of towns and cities as more people live and work in them.
Increased environmental and ecological footprints with city growth, leading to habitat clearing, degradation, and fragmentation.
Urban lifestyles: Consumptive, requiring significant natural resources and generating substantial waste, increasing air, water, and soil pollution. Unplanned urbanization is a major cause of environmental damage.
Urbanization benefits: Economic, cultural, and societal development.
Well-managed cities: efficient and effective, enabling economies of scale (advantages from increasing business size).
Threats to ideal concepts: Factors driving rapid urbanization, such as rural-urban migration due to the prospect of better employment opportunities and a better life.
Rapid population density increase: Can create severe problems, especially with insufficient planning, leading to widespread poverty.
Unplanned urban expansion: Creates large slums, exacerbates socio-economic disparities, and creates poor sanitary conditions that facilitate the spread of diseases.
Carefully considered urban planning and good governance with effective regulatory frameworks: Required for rapid urbanization to provide opportunities for all.
Key features of unplanned urbanization:
Urban sprawl and compactness
Unplanned urban growth
Land use change
Accelerated poverty
Poor air and water quality
Insufficient water availability
Waste-disposal problems
7.1.1 Causes of Unplanned Urbanization in Africa
Africa is rapidly urbanizing, expected to reach 2.5 billion urban dwellers by 2050, accounting for 21% of the world’s projected urban population.
Seven megacities in Africa: Cairo, Kinshasa, Lagos, Accra, Johannesburg–Pretoria, Khartoum, and Nairobi.
High degree of urban primacy: One city (usually the capital) has significantly greater population, economic activity, and political power than other cities.
Urban expansion in Africa: Characterized by unplanned and unregulated growth, exacerbated by the legacy of colonialism, structural adjustment programs, and neoliberalism.
Causes:
Unplanned and unregulated growth
The legacy of colonialism
Policy pressure of international institutions (e.g., IMF's structural adjustment program)
Pressure from developed countries (e.g., neoliberalism policies)
Weak urban planning institutions
7.1.2 Consequences of Unplanned Urbanization
High cost of living in urban areas.
Impacts on living conditions:
Development of Slums and Squatter Settlements
Random and unexpected growth leads to slums and squatters.
Exacerbated by fast-paced industrialization, lack of developed land for housing, rural immigrants seeking a better life, and high land prices.
Poor Infrastructure
Infrastructure quality is central to residents’ quality of life, social inclusion, and economic opportunities.
Determines city’s resilience to economic, environmental, social, and health-related risks.
African urban infrastructure is characterized by:
Insufficient infrastructure investments.
Weak transportation infrastructure (roads, railroads, airports, ports).
Inadequate electric power supply and distribution.
Serious shortage of water supply and sewage.
Weak communications infrastructure.
Economic Problems
High costs of housing, food, and transportation.
High unemployment rates.
Health Problems
Urbanization exacerbates health risks (e.g., obesity, respiratory diseases).
Lack of adequate sanitation exposes dwellers to high health risks.
Unplanned urbanization, high population density, poverty, and lack of infrastructure foster conditions for communicable diseases.
Social Instability
Rapid and unplanned urbanization can lead to urban violence and social unrest due to widening inequalities.
High population density fuels housing prices, contributing to disregard for urban poor residents and increasing social instability and crime.
Climate Change and Unplanned Urbanization in Africa
Climate change poses serious problems on urban centers in Africa. Rapid, inadequate and poorly planned expansion of cities in Africa leave urban populations highly exposed to the effects of climate change
Cities located near the sea or natural waterways are at more risk of flooding.
7.2 MIGRATION – FACTORS AND IMPACTS ON AFRICA
Human migration: Permanent change of residence by an individual or group of people.
Can occur within a country or across international boundaries.
Categories:
Internal and international migration.
Voluntary or forced.
Voluntary migration: Seeking better economic opportunities or a better life.
Forced migration: Due to war, drought, famine, natural disasters, or political conflicts.
Causes: Push and pull factors.
Push factors (economic): poor socio-economic conditions, low wages, high unemployment, and poverty.
Push factors (political and social): poor governance, corruption, political instability, conflict, and civil strife.
Pull factors: opportunity for a better life, favorable climate, fertile soil, good housing, good employment, high income, greater security, better quality of education and health care.
Africa has experienced important migratory movements, both voluntary and forced, contributing to its present-day demographic landscape.
7.3 COASTAL POLLUTION IN AFRICA
Major pollutants in the ocean caused by human activities along coastlines and inland.
Sources of coastal water pollution:
Discharge of sewage and industrial waste from coastal channels.
Dumping of wastes at sea.
Discharge of sewage and rubbish from ships.
Handling of cargo.
Accidental pollution by oil spills.
Pollutants from land via air and other routes.
Most frequent cause: Discharge of municipal sewage and industrial wastes into coastal waters or estuaries through low-quality disposal facilities.
Wastes containing persistent pollutants, discharged into rivers upstream, can reach the sea.
Factors affecting self-purification of the sea: dilution, temperature, adsorption, sedimentation, and nutrient deficiencies.
Marine environment: Generally unfavorable to the survival of most pathogenic organisms.
People in coastal zones and inland: Generate large quantities of wastes and polluting substances that enter the seas.
Coastal pollution: Rising rapidly due to population growth, urbanization, and industrial development.
Coastlines and marine protected areas of Africa: Under high threat from industrial wastes.
Coastal marine environment: Affected by habitat modification and destruction, over-fishing, and pollution.
Many coastal waters: Carry excessive sediment and are contaminated by microbes and organic nutrients.
Nitrogen pollution: From sewage discharges, agricultural and urban run-off, and atmospheric precipitation.
Destruction of wetlands and mangroves: Accelerates nutrient buildup.
Additional pollution sources: Oil leaks and spills from shipping, discharge of bilge water, oil drilling and mineral extraction.
Some persistent pollutants: Reaching deep ocean waters.
The Impacts Plastic Pollution in Seas and Oceans: A Case from Coastal Africa
Plastic pollution: one of the greatest threats to lives in oceans and seas worldwide.
Plastic pollution contributes to impacts on human health, loss of livelihoods, greenhouse gases emission, loss of biodiversity and compromises ecosystem functioning in all Africa’s land and seascapes.
Total global plastic production in 2020: over 400 million tons (UNEP estimates).
Major plastic producers: China (28%), North America (19%), and Western Europe (19%).
Major plastic consumers: China (20%), North America (21%), and Western Europe (18%).
Africa’s plastic consumption: 16 kg per person in 2015, compared to the global average of 45 kg and 136 kg in Western Europe.
South Africa: Ranked 11th in plastic pollution offenders in the Ocean in 2010 (WWF).
80% of marine pollution in South Africa: Originates from land-based sources.
Plastic recycling in South Africa is 16%. The rest of the 8 million metric tons discarded plastic ends up in rivers ending up in the ocean.
UNIT 8 GEOSPATAIL INFORMATION AND DATA PROCCESSING
8.1 Basic Concepts of Geospatial Information
8.1.1 The Similarity and Difference between Information and Data
I. Data
Data: Observations collected and stored as numbers, characters, images, facts, and symbols.
Describe a feature, idea, status, or situation.
Sets of values of qualitative or quantitative variables about one or more persons or objects.
Data is meaningful when further processed by human interpretations or input into a computer and the results disseminated.
Data lifecycle:
Data collection: New data (primary data) or existing secondary data.
Data processing: Checking for data quality, merging duplicate variables, and appending new information.
Data analysis.
II. Information
Information: Result of processing, manipulating, and organizing data in a way that adds to the knowledge of a receiver.
The context in which data is taken.
Some Differences between Data and Information
Data | Information |
|---|---|
Data is used as input for computer system | Information is an output |
Data is unprocessed facts or figures | Information is processed data |
Data doesn’t depend on information | Information depends on data |
8.1.2 Basic Concepts of Geospatial Data
Geospatial data: Data about objects, events, or phenomena with location information on the earth's surface.
Combines location information (coordinates), attribute information (characteristics), and temporal information (time).
Geographical data links place, time, and attributes.
Essential for map making.
A. Place
Location is essential in the collection of geographical data.
Locations are the basis for mapping an area of our interest.
Based on the location we can link different kinds of information to it, and measure distances and areas.
Without locations, data are said to be “aspatial” and have no value at all.
B. Time
Time is an optional element.
Many aspects of the earth’s surface are slow to change and can be thought of as unchanging. For example, height above sea level changes slowly because of erosion and movements of the earth’s crust, but these processes operate on scales of hundreds or thousands of years and for most applications (except
C. Attributes
Attributes: Descriptive information about objects, events, or phenomena.
Can be physical/environmental (e.g., temperature, elevation) or social/economic (e.g., population, income).
8.1.3 Visualizing Geographic Data
Two fundamental ways of visualizing geographic data:
Discrete objects
Continuous data.
A. Discrete objects
Represent an area as objects with well-defined boundaries in open space.
Has known and definable boundaries.
Example: A lake within the surrounding landscape.
B. Continuous data
Represents areas or phenomena that progressively vary across a surface or a location.
Values of a measure of variables may vary from point to point.
Also referred to as field, non-discrete, or surface data.
8.2 SOURCES AND TOOLS OF GEOGRAPHIC DATA
8.2.1 Sources of Geographic Data
Geographic data are collected from a variety of sources and in different formats.
Collected using instruments (e.g., temperature, rainfall, humidity) and advanced satellites (e.g., remote sensing).
Sources:
Directly Collected
Directly collected data are generated at the source of the phenomena being measured. Examples of directly collected data include measurements such as temperature readings at specific weather stations and elevations recorded by visiting the location of interest. Data can also be obtained through surveys (e.g., the census and sample surveys) or observation (e.g., counting the number of trees in a farmland).
Remotely Sensed
Remotely sensed data are measured from remote distances without any direct contact with the phenomena or a need to visit the locations of interest. Satellite images are examples of remotely sensed data.
Common general sources:
Hard copy maps (analogue maps)
Aerial photographs
Remotely-sensed imagery
Point data samples from surveys
Existing digital data files
8.2.2 Tools for Geographic Data Collection
Data collection: Gathering and measuring information on variables of interest.
Carried out systematically to map the area.
First step: Field survey.
Surveyors observe, measure, and record what they see
Geographic data is collected, to create a base map of an area. Then other information about the layers which are going to overlap on the map will be collected.
Data category
primary sources because these spatial and location data are received for direct use in making the map.
secondary sources refers to data of general interest gathered for many reasons which can further be used by end users, based on their interest.
Hard copy maps (analogue maps) can be used as a secondary source. The information on these sources can be used by enlargement of a map of the area of our interest on paper or by digitizing on a computer in a digital format. However, whenever we use data from secondary sources, we should be very careful and check if the data are right and up-to-date. Otherwise, our final result will be wrong and outdated.
Today, most mapping is done by remote sensing: gathering geographic information from a distance.
Data gathered includes elevation, land cover differences, and temperature variations.
Converted to a digital format.
Cartographers use data and computer software to make maps.
Tools:
Global Positioning System (GPS)
Digitizers
Global Positioning System (GPS)
A global positioning system is a satellite network that is used to determine the exact location of a place. It communicates with GPS receivers accessed by individual users on the surface of the Earth.
The GPS receiver needs to connect with four or more satellites orbiting the Earth, as a reference to calculate the precise location of the user within a few meters.
Digitizers
A digitizer is a tool used to change images on an analogue form or paper into a digital form on a computer.
Therefore, digitization is the process of converting information into a digital (i.e. computer-readable) format. The result is the representation of an object or image in a
Digitizers instruments: table digitizer, scanner and smart phones.
Data generated by digitizer provides geo-referenced.
Geographic data representation: Graphical visualization of the data or producing map of an area.
Maps are used in order to gain better insight and understanding of the area of our interest.
Two main forms of geographic data representations:
Hardcopy or analogue format
Digital format.
The digital format is becoming increasingly important in the world today.
Digital advantages over paper maps:
Can be used in digital devices.
Easy to copy and transmit at high speeds.
Stored at high density in small spaces.
Less subject to physical deterioration.
Easy to transform process and analyze.
A map is composed of different geographic features represented either as points, lines, and/or areas. Each feature is defined both by its location in space (with reference to a coordinate system), and by its characteristics (typically referred to as attributes).
Therefore, map is a model of the real world where all geographic features on the earth’s surface can be characterized and defined as one of the three basic features –point, line or area.
Point
Data exists when a feature is associated with a single location in space.
Examples of point features include a telephone network tower, water well and a weather station.
Line
Data exists when a feature’s location is described by a string of spatial coordinates.
Examples of linear data include rivers, roads, pipelines, etc.
Area
Data exists when a feature is described by a closed string of spatial coordinates.
An area feature is commonly referred to as a polygon. Examples of polygonal data include forest stands, soil classification areas, administrative boundaries, and climate zones.
Most polygon data are considered to be homogeneous, and thus they are consistent. Meanwhile, in the digital format, the same geographic features outlined above are stored and displayed in three basic types of spatial data models.
Vector
Raster
Image
The following diagram reflects the two primary spatial data storage techniques in the computer. These are vector and raster. Whereas, images reflect pictures or photographs of the landscape.
Vector Data Models
Vector storage implies the use of vectors (directional lines) to represent a geographic feature.
Vector data is characterized by the use of sequential points or vertices to define a linear segment. Each vertex consists of an X coordinate and Y coordinate or latitudinal and longitudinal values. Hence, point feature is defined by one coordinate pair of X and Y. Vector lines are also referred to as arcs and consist of a string of vertices terminated by a node. A node is defined as a vertex that starts or ends an arc segment. Polygonal (area) features are defined by a set of closed coordinate pairs.
Raster data models
Raster data models incorporate the use of a grid-cell data structure where the geographic area is divided into cells identified by row and column. This data structure is commonly called a raster.
The size of cells in a tessellated data structure is selected based on the data accuracy and the resolution needed by the user. Since geographic data is rarely distinguished regularly spaced shapes, cells are classified based on the most common attribute of the cell.
Therefore, raster data represent points by a single cell, lines by sequences of neighboring cells, and areas by collections of contiguous cells.
8.4 ADVANCES IN MAPMAKING AND THE BIRTH OF GEOGRAPHIC INFORMATION SYSTEM
8.4.1 Historical Development of Mapmaking
Mapmaking has been an integral part of human history for thousands of years.
The human activity of graphically representing one’s perception of the world is a universally acquired skill and one that pre-dates virtually all other forms of written communication. From cave paintings to ancient maps of Babylon, Greece, and Asia, right into the 21st century, people have created and used maps as an essential tool to help them define, explain and navigate their way through the world.
Mapping represented a significant step forward in the intellectual development of human beings and it serves as a record of the advancement of knowledge of the human race, which could be passed from members of one generation to those that follow in the development of culture.
Early maps were a garbled or distorted mass of land that bears no resemblance to the actual world. As the centuries passed, maps became larger, more detailed and more accurate.
8.4.2 Geographic Information System (GIS)
During the last few decades more sophisticated mapping systems appeared. It was mainly due to the advancement of geographic information system (GIS).
The geographic information system is a computer-based system that enables us to store, visualize, analyze, and interpret geographic data.
A geographical Information System (GIS) is a computer-based system for capturing, preparing, storing, checking, retrieving, manipulating, analyzing, and displaying geographically referenced data or geospatial data.
8.4.3 The Components of GIS
Working with GIS involves integration of five (5) key components, including hardware, software, data, people, and methods.
Hardware
The hardware is the computer and other devices (printers, plotters, scanners, etc.) Attached with it. The hardware helps the GIS to operate.
Methods
Methods are well-designed plans and application specific procedures and rules describing how the technology is applied.
guidelines, specifications, standards, and Procedures.
Software
GIS software provides the functions and tools users need to store, analyze and display geographical information.
GIS software; database software; operating system (OS) software; and network software.
Data
Geographic data (also called spatial, or geospatial data) identifies the geographic location of features. One of the most important components of GIS is the data. It is very important that data must be accurate.
Types of data include: vector data; raster data; image data; and attribute data.
Some basic GIS data can be obtained from the following web sites.
(https://africaopendata.org/dataset/ethiopia-shapefiles)
https://maps.google.com/
https://earth.google.com
https://www.diva-gis.org/gdata
People
GIS technology is clearly of limited value without people to manage the system and to develop plans for applying it. Users of GIS range from highly qualified technical specialists to planners, foresters, etc. to help with everyday work.
Administrators, Managers, GIS technicians, Application experts, End users, Consumers
8.5 MAKING AND INTERPRETATION OF GRAPHS, CHARTS AND DIAGRAMS
Many studies, researches and textbooks use data and numbers. Hence, presentations using charts, graphs, and diagrams can help the presenter draw and keep the attention of the listeners.
They are very important in describing trends, making a comparison, or showing relationships between two or more items.
Computer programs such as Microsoft Excel, Microsoft Word and other spreadsheets like SPSS (statistical package for social sciences) are widely used for making graphs, charts and diagrams.
There are so many types of graphs, charts and diagrams that can be produced on a computer.
Here are some common types out of which the user can make his or her choice.
Bar graph, line graph and pie chart can be prepared in Microsoft Excel.
Bar Graph
Bar graph is used to show relationships between different data series that are independent of each other. In this case, the height or length of the bar indicates the measured value or frequency.
Line Graph
Line graph represents how data has changed over time. This type of charts is especially useful when we want to demonstrate trends or numbers that are connected. For example, how temperature varies within one year.
Pie Chart
Pie chart is designed to visualize how a whole is divided into various parts. Each segment of the pie is a particular category within the total data set. In this way, it represents a percentage distribution of the variables under study.
Diagram
Diagram is a plan, drawing or outline created to illustrate how separate parts work and overlap at the connecting points. For example here is how we can draw the components of sustainable development in Microsoft Word.