Dew point temperature
Wind direction
Wind speed
Cloud cover
Precipitation
Compare the weather for the two cities and give a basic weather forecast for each.
What is the wind direction and wind speed at Gough Island in the southwestern corner of the map?
Wind direction at Gough Island is_______________________________
Wind speed at Gough Island is_________________________________
How do you know that a cold front is coming?
In what direction do cold fronts move in South Africa?
What type of weather will this cause across the country?
Assessment
Table 3.2.
Learning Outcomes(LOs)
LO 1
GEOGRAPHICAL ENQUIRYThe learner will be able to use enquiry skills to investigate
geographical and environmental concepts and processes.
Assessment standards(ASe)
We know this when the learner:
identifies sources of information, including simple statistics, to help answer the question about a social or environmental issue or problem;selects and records relevant information from sources for specific purposes (including recording and observing in the field);reports on enquiries, through discussion, debate, structured writing, graphs, tables, maps and diagrams.
LO 2
GEOGRAPHICAL KNOWLEDGE AND UNDERSTANDINGThe learner will be able to
demonstrate an environmental knowledge and understanding.
We know this when the learner:
explains why more people live in some places than others;identifies how access to different kinds of resources influences development in different places;describes some ways in which society has changed the environment.
LO 3
EXPLORING ISSUESThe learner will be able to make informed decisions about social and
environmental issues and problems.
We know this when the learner:
identifies inequalities within and between societies;analyses some of the factors that lead toward social and environmental inequality at different geographical scales and in different
places;evaluates actions that lead to the sharing of resources and reducing poverty in a particular context.
Memorandum
Activity 2:
Table 3.3.
Bloemfontein Weather properties
Port Elizabeth
21
Air temperature
17
2
Dew point temperature 13
NE
Wind direction
NE
5
Wind speed
10
none
Cloud cover
100% Overcast
none
Precipitation
Good chance
3.2. Climate and vegetation regions of the world*
SOCIAL SCIENCES: Geography
Grade 6
CLIMATE AND VEGETATION REGIONS OF THE WORLD
Module 8
The climate and vegetation regions of the world
You have learnt that prevailing weather conditions form the climate of a particular place over a period of time (20 – 35 years). As the weather is unpredictable, we are not able to say for sure that it will rain in Cape Town on New Year’s Day, but we do know that Cape Town will normally be drier at this time of the year than in June. Climatic conditions over a long period of time have shown that Cape Town receives most of its rain during the winter.
When we study the features of the types of climate that prevail in places, it is clear that large areas experience the same average conditions and that a type of climatic region is therefore formed.
Through the ages people have often been influenced by the climate when they must to decide where they want to settle. Large parts of the earth are either too cold, or dry or hot for people to live. The availability of sources also influences peoples’ choice of a place to live. That is why approximately six milliard people on earth occupy only 15% of the earth’s surface.
1. Factors that influence climate
You have learnt in grade 5 that there are many factors that influence the climate of a region.
We are now going to take a look at the factors that influence the worlds climate.
Latitude of a place
The hottest climates are usually in places closest to the Equator. The further we move from the Equator, the colder it becomes. At 12:00 the sun is directly overhead on the Equator. The rays of the sun are more concentrated and the temperatures rise higher. Further north and south the rays of the sun fall at an angle and are spread over a larger area by the earth’s rounded shape. That is why the sun’s rays are less concentrated and as a result the temperatures are cooler.
Figure 3.8.
At the equator the sun’s rays are almost directly overhead.
At the poles the sun islower on the horizon.
At the Equator high temperatures cause high evaporation, which causes a higher downpour.
Altitude above sea level
The earth absorbs the sun’s rays, converts them to heat and radiates them again. The closer we are to the source of radiation, the hotter it is, and the further we are from the source (e.g. on top of a mountain), the colder it becomes. We can experience the principle of radiation by holding our hands close to a fire (or heater) and then move them away gradually. It becomes colder the further we move away from the source.
It is always cold on top of high mountains. The highest mountain peaks on the earth are always covered with snow.
Activity 1:
To find information in an atlas
[LO 1.2, 1.3]
Use your atlas to find out:
the name and altitude of the highest mountain peak in South Africa;
the latitude and longitude co-ordinates for Mount Kilimanjaro.
Influence of ocean currents/oceans
The temperatures of the oceans influence the land temperatures. Winds blow the hot or cold air above the hot or cold ocean towards the land and increase or reduce the land temperatures. There are also winds that blow north and southwards from the Polar Regions bringing cold air onto the land.
Water has a larger heat retention capacity than the land has. The water, however, takes longer to heat during the day. Therefore the land reaches higher day temperatures than the water. The sea then has a “cool” influence from the sea to the land. During the night the land cools down much faster than the water, which then causes a “warm” influence from the sea to the land.
The result is that places along the coast or large water masses, experience a moderate temperature.
The margin between maximum and minimum is not very big.
Hot water evaporates faster and better than cold water. There is more evaporation above a warm sea current. This results in a higher precipitation in areas that border on warm sea currents.
Relief
In grade 5 we learnt that the escarpment diverts the rain bearing winds and clouds away from the interior. Mountains also have a sunny side and a shady side. The sunny sides have higher average temperatures, and the shady sides have lower average temperatures.
2. Climate and vegetation
As climate exerts an effect on vegetation, we find that both vegetation and human activities are relatively similar over large areas. Where one region changes into another, we find that a gradual change occurs over a large area. Such an area is referred to as a
transitional/intermediate zone. Forests do not suddenly change to grasslands, but the occurrence of trees gradually decreases and grasslands increase. The map on page 16 shows the different rainfall and vegetation regions of the world. Remember, there are no specific
boundaries. Maps will therefore differ slightly from one another.
The interaction between plants, animals, soil and climate within a demarcated area develops an ecological system, which we simply call an ecosystem. (Ecosystem = a selection of plants and animals in their own environment.)
The largest ecosystems that have developed on the earth are known as biomes. (Biome = a large area that houses similar plants and animals and relates to the distribution of climatic regions).
Activity 2:
To study climatic information
[LO 1.2, 1.3, 1.5]
Study the climatic information in the table on page 15 and answer the following questions: Determine the longitudinal and latitudinal position of each of these two cities. Which city is closest to the Equator?
In which countries are the cities situated?
Select a suitable scale and represent the climatological information graphically. Use a line graph to illustrate the temperature and a bar graph to illustrate the rainfall.
Which city experiences the greatest temperature fluctuations? How does this compare with
where you live?
Explain why the temperatures are so high and the temperature variations so little for these two cities.
During which months do these cities experience the highest temperatures and have the highest rainfall? How does this compare with where you live?
Table 1: Climatic information for Belèm and Singapore
Table 3.4.
Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sept Oct. Nov. Dec.
BelèmTemperature (oC) 25,6 25
25,6 25,6 26,1 26,1 25,6 21,1 21,1 21,1 26,7 26,1
Rainfall(mm)
318 359 359
320 259 170 149 115
89
86
66
155
SingaporeTemperature 26,7 26,7 27,2 27,8 27,2 27,2 27,2 27,2 27,2 27,2 27,2 26,7
(oC)
Rainfall(mm)
252 168 188
193 170 172 172 201
172 206 252
269
Assessment:
Table 3.5.
Learning Outcomes(LOs)
LO 1
GEOGRAPHICAL ENQUIRYThe learner will be able to use enquiry skills to investigate
geographical and environmental concepts and processes.
Assessment standards(ASe)
We know this when the learner:
identifies sources of information, including simple statistics, to help answer the question about a social or environmental issue or problem;
selects and records relevant information from sources for specific purposes (including
recording and observing in the field);
reports on enquiries, through discussion, debate, structured writing, graphs, tables, maps and diagrams.
LO 2
GEOGRAPHICAL KNOWLEDGE AND UNDERSTANDINGThe learner will be able to
demonstrate an environmental knowledge and understanding.
We know this when the learner:
explains why more people live in some places than others;
identifies how access to different kinds of resources influences development in different places;
describes some ways in which society has changed the environment.
LO 3
EXPLORING ISSUESThe learner will be able to make informed decisions about social and
environmental issues and problems.
We know this when the learner:
identifies inequalities within and between societies;
analyses some of the factors that lead toward social and environmental inequality at different geographical scales and in different places;
evaluates actions that lead to the sharing of resources and reducing poverty in a particular context.
Memorandum
Activity 1:
Thabana Ntlenjana – 3 482 m
S 27.20 E
Activity 2:
Belèm : 1.27 S 48.29 W
Singapore : 1.17 N 103.51 E
Belèm : Brasil
Singapore : Malaysia
Belèm
Intense isolation of the sun throughout the year. Every day is approximately 12 hours long.
Angle of incidence of the rays of the sun is vertical or close to it throughout the year.
Belèm : Temperature – November : Rain – February
Singapore : Temperature – April : Rain – December
3.3. The main biomes*
SOCIAL SCIENCES: Geography
Grade 6
CLIMATE AND VEGETATION REGIONS OF THE WORLD
Module 9
The main biomes (Vegetation regions)
1. The 5 main biomes
Vegetation across the world is divided into five large biomes:
1. The Forest Biome
Tropical forests
Temperate forests
Deciduous forests
Needle leaf forests
Mediterranean forests (Sclerophyll bush)
Savannah Biome
Grasslands Biome
Desert Biome
Tundra and ice fields Biome
Remember this!
Human beings have altered or destroyed the original environment of many parts of the world.
2. Area division of the different biomes
Table 3.6.
Main biomes of the world
Biome
Area(million km 2 ) Percentage
Forests
52,3
40,1
Savannah
21,8
16,7
Grasslands 8,8
6,8
Deserts
33,8
25,9
Tundra
13,7
10,5
THE FOREST BIOME
This biome is dominated by various tree species. In some forests the dense canopy of treetops grows so closely that sunlight cannot penetrate to the ground. In other areas the trees are further apart and sunlight can partially penetrate the tree canopy.
The most important of these forests is the tropical rainforest. These forests are close to the Equator (in the tropics) where it is hot all year round with a very high rainfall. Most of the trees in tropical rainforests are broadleaf, evergreen trees. Palms and tree ferns are also found here.
Relatively few people live in tropical rainforests because of the dense vegetation, which makes it difficult to move about.
In the deciduous forests,oak, walnut, willow and poplar trees are found. They shed their leaves during the winter season while the temperate evergreen forests are found in regions with rain throughout the year. Pine trees with their pine-cones, called coniferous trees, are found in these forests. Many different kinds of insects, reptiles, spiders and birds live in these forests. The deciduous and temperate forests are found mostly in the regions that are densely populated ((North America, Europe and Asia). Through the ages people have been dependent on these
forests for shelter, food, wood for their houses, weapons and energy.
Activity 1:
To discuss the effect of dense populations on natural forests
[LO 1.1]
Discuss in your groups the effect of densely populated areas on natural forests and how nature can be protected. Write a brief report on the findings of your group.
Needle leaf forests occur between 50 °N and 70 °S and are adapted to long, cold winters and short summers.
The downward sloping leaves of these trees make provision for snow to slide off the leaves.
The branches are supple; therefore the weight of the snow does not break them easily.
Very thick bark protects the trunk against the low temperatures.
The needle-like leaves also allow the snow to slide off easily and their small surfaces reduce the trees’ level of exposure to the cold winter winds.
The needles are covered with a waxy layer that reduces evaporation.
Unfortunately uncontrolled mining methods such as opencast mining, drilling for oil and the establishment of infrastructures that include roads and towns or cities, have damaged this natural biome to a large extent.
In areas with a winter rainfall where the rain develops out of cyclones that come from over the seas, we find Mediterranean forests. These regions experience long, dry summers. The vegetation consists of small knotty trees with leathery leaves. Shrubs cover most of the landscape.
The plants have adapted in various ways to the summer drought conditions.
Some have tough, leathery or waxy leaves to protect them against the summer heat, and to
minimize evaporation (protea).
Some have fine hairs on their leaves to reflect the sunlight (silver tree).
A thick bark layer around the trunk also reduces evaporation.
Activity 2:
To depict a forest biome by means of collage
[LO 1.5]
Choose any one of the afore-mentioned forest biomes and make a collage to depict it.
THE SAVANNAH BIOME (tropical grasslands)
This is a transitional region between the wet tropical rainforests and the dry desert and semi-desert regions. It occurs over large areas of Africa and South America, and is also found in Australia, Central America and South-East Asia.
The savannah grasslands have an annual rainfall of 750 to 1 500 mm, which falls during the summer months. This means that evaporation is high. The rainfall is not as dependable as it is in the tropical rainforests, and droughts occur regularly. The winters are dry and cloudless, with warm days and cold nights.
The landscape has a park-like appearance with characteristic trees and tall-growing grasses.
More trees grow where there is more water and along the rivers, and grass predominates in the drier parts. During winter the grass dries up and trees shed their leaves, but the landscape turns into a paradise again as soon as the first rains begin to fall in spring. The baobab, mopani, acacia and umbrella-shaped camel thorn trees of Africa are well-known trees of this biome. In Australia, eucalyptus trees are the dominant trees of the biome.
Fires often rage in savannah regions and prevent trees from gaining the upper hand. The heat of the fires does not affect the grass roots, only the weaker trees. The eradication of the weaker trees ensures that the veld remains clear for grasses to revive again after rain.
Large herds of grazing animals like zebras, various antelopes, giraffes, wildebeest, etc. occur here.
Activity 3:
To design a poster of a savannah landscape
[LO 1.5]
Table 3.7.
The class divides into two groups.Group 1: Collect photographs, pictures and newspaper or magazine clippings that show the landscape and the various animals of the savannah and use these to make a large poster for the classroom.Group 2: Collect information on the various well-known nature reserves that have been established in the savannah regions and use it to make a poster.
THE GRASSLANDS BIOME (temperate grasslands)
The temperate grasslands are found in the regions that form a transition between the warm and cold areas of the earth. They are normally found in the interiors of continents and the climate is referred to as a continental climate. This means that it is cool and temperate, with cool to cold winters and warm summers. The precipitation varies between 300 and 500 mm per year.
Temperate grasslands cover large areas of the earth and have been given different names in different parts of the world:
North America – the Prairies
Asia and Europe – the Steppes
South America – the Pampas
Australia – the Downlands
South Africa – the Veld
In the RSA, the Transvaal Highveld is typical of the grassland biome.
The trees are sensitive to frost and are therefore mainly restricted to riverbeds. Exotic trees like eucalyptus and pine trees, which were introduced by people, do well in the region. The main type of vegetation of this biome in South Africa is the local perennial red grass.
Large parts of the biome have been altered through the intervention of people. Areas have been ploughed to grow mealies and wheat, or are used for grazing. Overgrazing results in the
deterioration of the soil and erosion follows. The original animal life has also largely vanished.
In South Africa, these parts have been destroyed by mining and the resultant urban
development.
DESERT BIOME
Semi-deserts and deserts, in particular, are those areas of the world where there is an extreme shortage of water because of very low rainfall. The average annual precipitation usually is below 250 mm and there may be years in which no rain is recorded. Daytime temperatures in summer are very high, although they may be more bearable than the high temperatures of the Tropical rainforests because of the low moisture content of the atmosphere. The nights are cold because of very fast cooling when the sun sets.
Typical climatic features of semi-desert and desert environments are:
1. Low annual rainfall (less than 250 mm per year)
2. Unreliable precipitation (varies from year to year)
3. Low moisture content of the atmosphere
4. High evaporation
5. Extreme daily fluctuation in temperature
The true deserts are on the five continents:
Namib Southern Africa / Namibia
Sahara North Africa
Thar Pakistan / India
Ar Rub’ al Khali Saudi Arabia
Taklimakan China
Alacama South America (Chile / Peru)
Mojave North America
Vegetation here is either very sparse or non-existent.
Most of the plants that are found here are annual plants that complete their life cycle –
germination, growth, flowering, seeding and wilting – in a few months. In this regard, you might picture Namaqualand after rain!
The vegetation in semi-desert regions is suitable for grazing. The plants are xerophytes –
plants that are well adapted to the dry conditions. Some have leaves that are covered with fine hairs or with a waxy layer to restrict evaporation. Others like vygies (mesems) are able to store water in the plant tissue. They are called succulents.
Semi-deserts occur over large areas of the world. They form the border areas of true deserts, and together with deserts they cover approximately one-third of the earth’s surface. In South Africa the Karoo and the Kalahari are examples of semi-deserts.
Activity 4:
To do research on desert expansion and write a report about it
[LO 1.4, 2.3]
People are responsible for the desert regions becoming bigger and bigger. Do research on this topic and write a report of approximately one page. Make suggestions on how the problem can be addressed.
The Tundra Biome and the ICE FIELDS
The Tundra biome occurs north of 65 °N as a broad zone extending around the Northern Arctic Ocean in Alaska, Canada, Greenland, Iceland and as far as the Bering Sea to the east of Asia. In the Southern Hemisphere it is represented in a small area on Terra del Fuego at the southern tip of South America.
Climatic conditions in the Tundra biome are characterised by extreme cold. During the long winter months, the temperature falls to far below freezing point. Snowstorms with icy winds occur continuously. Nothing grows and plants remain dormant for many months while the
ground is frozen.
During the summer, the temperature may rise to ± 10 °C, but the summer only lasts for three to four months. Only the surface layer of the soil actually thaws and water from ice that melts cannot drain away, so that many areas become flooded and marshes are formed. Rainfall in
these regions is low – 250 mm per year – and the rate of evaporation is low, which adds to the impossibility of water draining away.
Tundra vegetation is therefore adapted to low temperatures and superfluous water. Plants grow quickly. The plants, which come to life in the summer and develop as if overnight, are mosses, lichens, ferns, low shrubs, grass and flowering plants. Animal life is also adapted to the natural conditions. The most common animals of this biome are reindeer, wolves and bears.
The area is sparsely populated. The Eskimos of Greenland are one of the nomadic groups of people that inhabit the Tundra.
The Ice deserts / Polar deserts are the uninhabitable areas that comprise Antarctica (6th continent), large parts of Greenland, the Northern Arctic Sea and mountain tops with a
perennial cover of snow. These ice deserts do not form part of the Tundra biome.
These areas are too cold for vegetation. Land animals are also absent, however sea animals such as polar bears, whales, seals and sea elephants are plentiful. A variety of birds have their breeding colonies in these areas.
Activity 5:
To do research on Antarctica and describe the climatic conditions
of the ice deserts
[LO 1.5]
Describe the climatic conditions that prevail in the ice deserts after having done research on Antarctica.
Assessment
Table 3.8.
Learning Outcomes(LOs)
LO 1
GEOGRAPHICAL ENQUIRYThe learner will be able to use enquiry skills to investigate
geographical and environmental concepts and processes.
Assessment standards(ASe)
We know this when the learner:
identifies sources of information, including simple statistics, to help answer the question about a social or environmental issue or problem;
selects and records relevant information from sources for specific purposes (including
recording and observing in the field);
reports on enquiries, through discussion, debate, structured writing, graphs, tables, maps and diagrams.
LO 2
GEOGRAPHICAL KNOWLEDGE AND UNDERSTANDINGThe learner will be able to
demonstrate an environmental knowledge and understanding.
We know this when the learner: