What is scale?
A map represents a given area on the Earth’s surface. Maps are produced at various scales. This relationship between the map and the ground is shown in different ways. Word scale — The map distance and the ground distance it represents are written in words such as 1 cm represents 500 m.
Representative fraction or ratio scale — The unit of the map distance is the numerator and the equivalent ground distance is the denominator. A representative fraction of 1:50 000 means that one unit on the map such as a centimetre represents 50 000 of the same units on the ground.
Line scale
Large and small scale maps
Large scale maps show a lot of detail over a small area and small scale maps show little detail over a large area. A 1:10 000 orthophoto map has a larger scale than a 1:50 000 topographic map. A map of the world at a scale of 1:10 000 000 is a very small scale map.
How do you calculate distance and area?
- 1 cm represents 50 000 cm
- 1 cm represents 500 m
- 1 cm represents 0,5 km
- or 1 mm represents 50 m
- 1 cm represents 1o ooo cm
- 1 cm represents 1oo m
- 1 cm represents 0,1 km
Calculating distance
Remember to distinguish between measuring straight line and curved-line distances.
1:50 000 (topographic maps)
1:10 000 (orthophoto maps)
Estimating area of a rectangle
When calculating a regular area apply the formula: length x breadth.
Use ground distances when calculating
First convert the map distances to ground distances before doing the calculation.
You must be able to convert both your km2 or m2 area to hectares (ha).
One hectare (1 ha) = 100 m x 100 m = 10 000m2
1 km2 = 10 ha x 10 ha = 100 ha
To convert km2 to hectares multiply your answer by 100
To convert m2 to hectare divide your answer by 10 000
What is the relationship between contours and cross-sections?
- A contour is a line joining places of the same height above sea level.
- The vertical distance between two consecutive contours is always the same. It is the contour interval.
Bearing is a much more accurate measured clockwise from ma way of indicating direction. Bearing is an angle gnetic north (magnetic bearing) or true north (true bearing). The starting point to determine bearing is the north-south line. North will then always be 0°. Bearing is always measured clockwise from north at 0° through a full circle to 360°. Bearings are measured using a protractor and given in degrees.
What is true north?
True north is also known as geographical north. It is the actual point on the Earth’s surface that coincides with the north pole.
What is magnetic north?
Magnetic north is the northern magnetic pole of the Earth. Presently it lies approximately north west of Canada and about 1 ooo km from the true north pole. Magnetic north is the north that a compass will point to and it shifts slowly east or west of true north.
What is magnetic declination and how is it calculated?
- Determine the difference in years. Current year minus first date in brackets
- Multiply these years with the mean annual change
- Add or subtract this total annual change from the magnetic declination.
- If the average change is westwards ADD!
- If the average change is eastwards- SUBTRACT!
- 2010 - 2002 = 7years
- Annual change 12'west
- 7 x 12' = 84'
- 84' = 1o 24'
- Annual change is west ADD to magnetic declination
- 23o22'+1o24'=24o46'
Example
How to calculate magnetic delination
What is grid referencing?
The absolute position of any place can be located by determing the latitude and longitude of the place. This consists of latitude north or south of the equator.
- All latitude in South Africa are south of the equator
- All longitudes in South Africa are east of Greenwich, or the Prime Meridian
How to determine location accurately
- Draw a very light pencil line in the minute frame (that surrounds the map on the outside) opposite the relevant feature. Do this for both the latitude (left or right) and the longitude (top or bottom).
- Start by counting the latitude minutes from the
top ofthe map to the minute section directly opposite ”
the geographic object in question marked with the pencil
line.
Subdivide the minute section as follows:
- Divide it halhway-this will be the 30" value
- Divide each half (30") into two (quarters). These will be the 15" and 45" values respectively.
- Divide the relevant quarter (where the b m pencil line has been drawn) now into three equal parts that will each represent 5".
- The correctnumberofseconds can now be easily and accurately determined as 18". The latitude value will then be 34° 16'18" S.
- To determinethe longitude value, repeatthese steps by counting the minutes from left to right.
Map and photo interpretation
Questions on map interpretation can be set from anywhere in the Grade 12 syllabus. You should use the topographic maps, aerial photographs and orthophoto maps in Via Afrika Geography Grade 12 to work through :
How to systematically read and analyse a map or aerial photograph possible.
- Tourist attractions, holiday resorts and monuments
- Recreation facilities such as sport stadiums, golfcourses, racetracks, shooting ranges
- Airports and aerodromes are determined by flat surfaces, far from build-up areas (safety and noise)
- Uses of large dams: drinking water; water purification plants; irrigation: canals and furrows, cultivated fields and orchards; recreation: camping sites, sail and ski (slipways), and angling
- Infrastructure: type and number of roads, railway lines, power lines, harbours as well as how infrastructure relates to the topography and drainage
limate and weather
Position latitude (climate of place) and longitude; proximity of mountains and oceans; distance from the sea (maritime or continental)
Rainfall year round: perennial rivers; seasonal (summer or winter): farm dams, irrigation, non-perennial rivers, agronomy; dry to arid: wind pumps, large farms, stock farming; sufficient rain: forests (>750 mm)
Temperature latitude position determines how cold/cool/hot a place is; height above sea- level (cold or warm) and slope front (shadows or sunlight); temperature inversions at night
Wind rows oftrees or windbreaks; landing strips and aerodromes; valley winds: catabatic (night) and anabatic (day)
Relief and topography
Regions mountains and plains, high and lowlands, highest and lowest points
Terrain forms size, average height above sea-level, extent (direction)
Slope steepness, convex, concave, straight, uniform, slope type (crest, cliff, talus slope, knickpoint, pediment)
Type of landform valley, spur, gorge (ravine), cliff, waterfall, terrace, saddle (neck), pass
Landscape mountainous, undulating, hills, plains, floodplains
andforms associated with structural landscapes
Horizontal strata plateaux, table mountains (mesas), buttes, conical hills
Inclined strata cuestas, homoclinal ridges, hogsbacks, dip slopes and scarp slopes
Massive igneous rock dome shaped landforms (batholiths, laccoliths, lopoliths), tors, dykes
Fluvial process
Drainage basins watersheds, trunk (main) and tributary rivers
Stream pattern dendritic, trellis, radial, rectangular, centripetal, deranged
Stream orders lengths, number, gradient, basin area
Stage and shape length-profile (upper, middle lower course) cross-profile (\/-shaped, broad/wide)
Features waterfalls, rapids, braided streams, undercut river bank, slip-off river bank
Stream direction always to the sea; from high to low areas; contours bend upstream; dam wall on the downstream side; tributaries join trunk with an acute angle
Stream piracy watershed, capturing river, misfit stream, elbow of capture, wind gap
Features ofthe fluvial cycle stages
Upper course high watersheds, V-shaped valleys, steep gradient, short, small and many tributaries, waterfalls and rapids, fast flow, erosion vertical
Middle course gentle slopes, watershed on lower levels, open valleys, longer and less tributaries, gentle river bends, erosion and transport start to be sideways
Lower course broad valleys, gentle gradients, flood plains, meanders and oxbow lakes, deposition, slow flow, braided streams
Settlements
Site physical nature ofthe exact piece of land on which a settlement is located
Situation relationship of a settlement with its immediate and wider environment (geographic placement with reference to relief, drainage, transport routes, and utilisation of soil)
Function unifunctional (rural with primary activities); multifunctional (urban with secondary, tertiary and quaternary functions)
Rural settlement
Patterns dispersed/isolated (buildings farfrom each other), farmsteads; nucleated/clustered (buildings close to each other), farm villages
Factors determining site drinking water, plough land, grazing land, building material, fuel
Factors determining shape linear (road, river, mountains, sea); circular (central point—town square, market, church); crossroad (junction/intersection of roads)
Urban settlements
Factors determining site water supply, nature of soil, relief(flat surface), roads, rivers, railway lines, sea, defensibility, function
Type central place, commerce, transport, specialised
Morphological structure shape (circular, linear, star shaped); street plan (grid, radial, irregular); physical expansion (commercial ribbon development, multiple cores, exclusive residential and work areas, residential differentiation)
Land use zones central business district, retail area, residential, light and heavy industries, rural-urban fringe
Economic activities
Primary activities commercial —good infrastructure, irrigation, large farms, winery, saw mill, sugar mill, abattoir, mines, fishing harbours, and so on; subsistence —few roads, no power lines, footpaths, small areas of cultivated fields
Secondary activities light industries- close to CBD, road transport, raw materials agriculture; heavy lndustries- far from CBD, rail transport, raw materials, mainly mining; factors influencing site — level area, raw materials, transport, electricity, water, market
Tertiary activities provision of services such as education (schools, colleges, universities), tourism, holiday resorts, commerce, medical and health care, airports, electricity supply
Also take note of the following
What are the conventional map signs and symbols?
Every 1:50 000 topographic map has a key or reference at the bottom of the map (Figure 6). The reference explains the symbols used on the map and helps you to understand the map information.
What are contours and landforms?
Maps are two dimensional representations on a flat sheet of paper but height can be shown by spot heights, bench marks, trigonometrical beacons and contours.
How are landforms recognised on a topographic map?
How do you construct cross-sections from 1:50 000 maps?
Cross-sections are constructed in four steps, illustrated in Figure 8 on the next page.
- Prepare the profile framework.
- Gather the data.
- Transfer the data.
- Complete the profile.
- Two points of the same height are intervisible if there is no higher terrain between them.
- Where contours show a convex slope, the summit of the hill is not visible from the foot of the hill.
- Where contours show a concave slope the summit and foot of the hill are intervisible.
Step 1.
Prepare the profile framework Base line represents exact map distance. Mark vertical lines with scale ranging between one division beyond the lowest and highest points.
Step 2.
Gather the data On the edge ot a strip oi paper mark otf the position and height of each contour line.
Step 3.
Transfer the data Hold the strip oi paper between the vertical lines. At each height transfer the points where the contours cross onto the profile.
Step 4
Complete the protile Join the points to represent the natural rise and tall oi the landscape and shade the prolile. Add title, end heights, feature labels, venical and horizontal scales and venical exaggeration.
What is vertical exaggeration?
Vertical exaggeration is the deliberate vertical expansion of the cross-section's vertical scale in order to see height variations more clearly. Vertical exaggeration is calculated by dividing the vertical scale by the horizontal scale, where both scales are expressed as representative fractions.
Calculating vertical exaggeration
Vertical scale / horizontal scale = 1/2000 / 1/5000 = 50000/2000 =25 times
What is intervisibility?
Intervisibility is when you can see one point from another and it can be determined by examining the contours.
What is gradient?
Gradient is the relationship between height and distance. It is written as a ratio. The gradient tells us how steep a straight line is. We calculate gradient to find out how steep or gentle a slope is. An easy way to remember the ratio for gradient is RISE:RUN. Learn this formula and write it down when doing gradient calculations. You might be given a mark even if you get the calculation completely wrong.
Orthophotos are aerial photographs with the distortions caused by camera angle removed so they are true to scale. An orthophoto map has added details such as contour lines, place names, spot heights and trigonometrical stations added. They are drawn to a scale of 1:10 000.
GIS is a computerised system consisting of hardware, software and methods designed to capture, manage, manipulate, analyse, model and display spatial and non-spatial data to solve planning and management problems.
Key terms in GIS
Spatial data This is all data that are shown with symbols on a map. The spatial data for a school could be its exact latitude and longitude.
Attribute or non-spatial data This is that information which describes the spatial characteristics of the spatial features. The attribute data for a school could that it is a high school for 345 boys and 360 girls.
Vector data This is data of geographic features shown in point (a node such as a school), line (an arc such as a river) and area (a polygon such as a dam) format.
Raster data This is data of geographic features shown with grid cells.
Spatial resolution This determines how clear and easy the detail is to see.
Buffering This is the creation ofa zone ofequal width around a point, line or area feature in GIS. An example of buffering is where it is not allowed to plant any trees in a plantation closerthan 5o metres from any river.
Remote sensing This is the gathering of information about the Earth from weather balloons, aeroplanes and satellites.
Data or thematic layering This is when different types of information are placed one on top ofthe other in layers to see the overall picture. Such layers on a topographic map could be: vegetation, contour lines, roads, rivers or built up areas.
Work through the activities on GIS in the Learner’s Book on pages 51, 247 and 253 to revise this topic. There will always be questions on GIS in Exam Paper 2 and they could also appear in Exam Paper 1
General characteristics
- Mid-latitude cyclones are also known as frontal depressions, depressions and extra- tropical cyclones. They are low pressure systems (lows) associated with the meeting of warm and cold air masses.
- As the two air masses have different densities, they do not mix readily but will be ‘separated’ by a front.
- In the Southern Hemisphere winds rotate clockwise into the centre of the low. In the Northern Hemisphere winds rotate anti-clockwise into a low.
- The diameter of mid-latitude cyclones ranges from 1 ooo to 4 ooo km.
- They occur all year round, but in South Africa their influence is strongest in winter, bringing the familiar cold fronts often accompanied by rain. In summer they move further south of the country.
- These travelling cyclones range in strength from a mild disturbance to a powerful storm.
Definitions
Cyclone: A cyclone is an area of low pressure usually associated with wet and windy weather.
Front: A front is a boundary separating two air masses with different temperature and moisture characteristics.
Warm front: A warm front is found where warm air replaces cold air.
Cold front: A cold front is found where cold air replaces warm air.
Where do mid-latitude cyclones form?
These weather systems occur between approximately 30° and 60° north and south of the Equator. In both hemispheres they move from west to east within the westerly wind belts :
ometimes a series of fronts will develop, in which three or four fronts follow one after the other in a ‘family’ of fronts. In the Southern Hemisphere the oldest frontal system (which arrives first) will be furthest towards the south-east. Each younger member is slightly further north and west than its predecessor.
What are the conditions necessary for the formation of mid-latitude cyclones?
A mid-latitude cyclone is a large spiral of air that forms and breaks up, along the polar front. The conditions favourable to the formation of a mid-latitude cyclone are:
- Two large high pressure systems (anti-cyclones) are in contact on the polar front.
- The warm, subtropical high pressure contains a warm, moist maritime air mass.
- The polar high pressure contains a cold, dry air mass.
- The air flow converges from opposite directions on the two sides of the polar front.
- Disturbances on the polar front cause a local low pressure into which air will flow and around.
What are the stages of development and related weather conditions of mid-latitude cyclones?
The diagrams below show the four stages in the development of a mid-latitude cyclone.
The initial stage
- Warm, moist subtropical air meets cold, drier air along a stationary polar front.
- There is no movement across the polar front (Figure 12).
- The air masses do not mix, but move parallel to each other in opposite directions on both sides of the front.
Development or wave stage
A disturbance occurs on the polar front and it now has a wave-like appearance :
Mature stage
- Cold air moves in a northerly direction, west of the low pressure centre. A cold front develops.
- Warm air is pushed in a southerly direction, east of the low pressure centre. A warm front develops.
- Winds blow clockwise around and into the low pressure, in the Southern Hemisphere :
Occluded stage
- Cold air wedges in under the warm air, lifts it up and isolates the warm air from the Earth’s surface. This process is called occlusion. The front that is formed is called an occluded front (Figure 15).
- Diagram below shows what happens three-dimensionally as the system develops to the occlusion stage.
Dissipating stage
In the dissipating stage, cold air completely isolates warm air from the ground as all the warm air has been lifted high above the ground.
What is the weather associated with mid-latitude cyclones?
Questions on the weather associated with mid-latitude cyclones and the reasons are often set in exams and you should make sure you know and understand Tables 3 and 4.
Reasons for weather changes at the cold front
Changes | Reasons |
---|---|
Temperature falls | The cold air behind the cold front has arrived. |
Wind backs | Air blows in a clockwise direction around a Southern Hemisphere low pressure system |
Cloud cover increase | The warm rises over air, is cooled and condenses |
Pressure drops | Pressure is at its lowest just ahead of the cold front |
Rain falls | If the rising air is sufficiently moist and unstable heavy rain falls |
What are the general characteristics of tropical cyclones?
Tropical cyclones cause considerable loss of life and damage to property, vegetation and economic activities, mostly along the east coasts of continents.
- Tropical cyclones are intense low pressure systems.
- They originate in late summer or autumn over warm tropical oceans (at least 26 °C), except in the southern Atlantic Ocean.
- They need Coriolis force to form, which is zero within 5° of the Equator, so they develop within latitudes 5° and 20° N and S.
- They move westwards at a rate of 4o—2oo krn a day. Near 2o—3o° N and S, they tend to curve back eastwards at a rate of 500-700 km/ day.
- As low pressure areas, their rotation is clockwise in the Southern Hemisphere and anti-clockwise in the Northern Hemisphere.
- The source of energy in tropical cyclones is the large amount of latent heat released as rising warm, moist tropical air condenses.
- They are accompanied by heavy rain, storm surges and high winds.
Where do tropical cyclones form?
What are the factors necessary for tropical cyclones to form?
Exam questions are often set on the requirements and reasons for the formation of tropical cyclones and you should make sure you know and understand the Table below
Table Requirements and reasons for the formation of a tropical cyclonr
Requirements | Reasons |
---|---|
Ocean temperatures over 27oC |
|
Unstable air | Atmospheric instability makes convection possible. |
Very low pressure and steep pressure gradient |
|
An undisturbed period of several days | Time is needed for the slow convergence of warm moist air towards the low pressure center. |
Some upper-air triggering action | A strong horizontal divergence of air at upper levels stimulates the circulation and formation of vortex. |
Winds must be light and variable before the formative period | Strong winds or winds from a constant direction:
|
What are the stages of development of tropical cyclones?
The life cycle of a tropical cyclone, which may last a number of days, can be divided in four stages :tabel below. Nevertheless, unfavourable conditions may stop the development at any stage.
Formative stage
- The pressure is still above 1 000 hPa but dropping quickly.
- Winds are already at gale force in the front left-hand ® quadrant.
Developing stage
- Pressure is now below 1 000 hPa and continuingto fall.
- Winds are now hurricane strength in the front left-hand quadrant near the eye, with gales further away
Mature stage
- Pressure is now very low, as low as 900-940 hPa in the /v eye but has stopped falling.
- Weather and winds (hurricane strength) are at their an worst especiallyin the worst weather quadrant
Degenerating or dissipating stage
What are the associated weather patterns?
Weather conditions at the passage of a tropical cyclone :
As the cyclone approaches | As the eye is overhead | As the cyclone moves away |
---|---|---|
|
|
|
A cross-section through a mature tropical cyclone
How do you recognise tropical cyclones on synoptic maps?
Characteristics of a tropical cyclone on synoptic maps are:
- a low pressure cell with closed isobars between 5° and 30° N and S of the Equator
- symbol for tropical cyclone in the eye (centre of low pressure)
- name of the tropical cyclone written next to system
- the date of the map in late summer or early autumn.
What are the impacts of tropical cyclones on human activities and the environment?
Tropical cyclones are the most destructive natural hazards in terms of frequency and number of deaths. Not only people, but also the natural and constructed environments are affected. The main causes of the destruction are heavy rain, strong winds and, in coastal areas, the storm surge. The storm surge often causes the most damage. In more developed regions, such as the USA, the damage is mainly monetary while in the less developed areas, such as Mozambique, there is more loss of life and less monetary damage.
In more developed regions, such as the USA, the damage is mainly monetary while in the less developed areas, such as Mozambique, there is more loss of life and less monetary damage.
What are the strategies to help prepare for and manage the effects of tropical cyclones?
Warnings about impending tropical cyclones are normally given by the local weather office. You should listen regularly to the radio and/or watch TV and pay attention to advice and instructions.
The difference between tropical cyclones and mid-latitude cyclones Tropical cyclones
Tropical cyclones | Mid-latitudes | |
---|---|---|
Names | Typhoons (China,]apan) Hurricanes (America) | Extra-tropical cyclones, mid-latitude cyclones, depressions |
Origin | Tropical oceans 5-30“ N and S | At polar front 4o—6o° N and S |
Pressure | Very low | low |
Pressure gradient | Very fast | Not as fast |
Movement | East to west carried by tropical easterlies | West to east carried by the westerlies |
Wind speed | Very fast | Not as fast |
Size | 250-500km diameter | 1000-3500 km diameter |
Weather | Hot, destructive winds, heavy rain | Cool, cloudy and rainy |
Subtropical anticyclones and associated weather
South Africa's climate and weather are determined by three controlling factors
- The influence of the surrounding ocean. The oceans moderate the temperatures of coastal areas. The warm Agulhas current promotes rainfall on the east while the cold Benguela current makes for a dry west coast.
- The plateau of the interior (altitude). Most of the interior of South Africa lies at an altitude of 1 500 metres above sea level. This lowers the temperature of the interior.
- The subtropical anticyclones. This means that South Africa generally has a dry climate with high temperatures.
What are the characteristics of the high pressure cells?
The high-pressure cells are weather systems characterised by:
- descending air
- air that comes from the drier upper atmosphere
- descending air warming at around 1 °C / 100 m
- clear, sunny and dry weather conditions
- moving northwards in winter and southwards in summer.
How does the anticyclonic air circulation around South Africa influence the weather and climate?
Winter: Subsiding air in the Kalahari cell heats lower layers causing a dry interior. Because of the cold plateau with no rising air, an inversion layer is formed. This is often lower than the escarpment and prevents moist air moving in from the Indian Ocean.
Summer: The sinking air of the Kalahari high pressure cell is weaker. The plateau is hot and air rises, causing thermal lows. The inversion layer is now higher, above the escarpment. Warm, moist air can flow in from the ocean, causing extensive rainfall in the eastern part of the country.
What are the travelling disturbances associated with anticyclonic air circulation in South Africa?
Line thunderstorms and moisture fronts
Most thunderstorms over the interior are associated with a moisture front extending from the north-west to the south-east.
How the moisture front develops
Moist, warm, unstable air from the South Indian high comes in from the north-east. Drier, cooler, more stable air comes in from the South Atlantic high from the south- west. The contact zone between these different air masses is known as the moisture front.
The dry, cooler air from the south-west is denser and heavier and it ridges in under the north-east air mass, forcing it to rise and causing cooling and cloud formation in the moist, north-east air mass. Thunderstorms develop in a wide strip north-east of the moisture front or trough axis. Line thunderstorms only develop in summer because of the lifting of the inversion layer in summer.
The coastal low
A coastal low-pressure system is a weak low pressure cell, about 100 km wide, in the lower layers of the atmosphere. Coastal lows occur when the wind blows from the land to the sea. This results in warm, often strong, offshore berg winds in front of the low and cool onshore flow behind it.
The clockwise circulation causes an off-shore air flow on the leading side. As this air is heated adiabatically it reaches the coast as a dry, warm (berg) wind. On the non-leading side of the coastal low the air is on-shore and brings cool, cloudy weather.
Berg winds
Berg winds are warm, dry offshore winds, descending from the high-lying areas and blowing towards the sea. Berg winds occur mainly in winter, but they can also cause very dry and hot days during other seasons. Berg winds can be recognised on synoptic charts by:
- temperatures much higher than the normal for winter especially along the coast
- low humidity
- a large depression to the dew point
- winds blow from the interior to the sea.
Synoptic weather maps linked to subtropical anticyclonic conditions
Summer conditions
- The westerly wind belt and its depressions move south of the continent (Figure 27)
- Temperatures generally are high.
- The South Indian high is situated eastwards and anticlockwise circulation transports moisture on its way to the continent.
- Uplift along the escarpment can cause clouds and precipitation.
- The South Atlantic high is closer to the west coast and brings in dry air.
- A moisture front forms where the different air masses from the Indian and Atlantic Oceans meet (west of the low pressure trough).
- Thunderstorms develop along the moisture front.
- Note the position of tropical cyclone Dando on :
Winter conditions
The synoptic weather map in Figure 28 illustrates weather patterns typical of winter conditions.
- The pressure systems shift northwards.
- The cold fronts are closer to the continent.
- Temperatures are generally lower than summer conditions
- The Kalahari anticyclone is over the interior. This results in dry conditions with little cloud cover.
Reading and interpreting synoptic maps
- Isobars close together show a steep pressure gradient and strong winds. When isobars are far apart there is a gentle pressure gradient with weak winds.
- In the Southern Hemisphere air circulates clockwise round low pressure and anti- clockwise round high pressure.
- Low pressure cells show that air is converging and rising and there is a possibility of rain. High pressure cells show diverging subsiding air and the skies will be clear.
- Onshore winds bring moist air onto the land. Offshore winds are dry.
- The sub-tropical high pressure belt is split into three: the South Atlantic high, the Continental or Kalahari high and the South Indian high.
- These pressure cells are further south in summer and further north in winter. The Kalahari high is usually only seen in winter.
- A trough of low pressure can usually be found over the land in summer. It extends from the north-west (Namibia) to the south east (Eastern Cape).
- Mid-latitude cyclones usually blow over the land in winter but are usually further south in summer and miss the land.
- Sometimes there is a coastal low pressure cell on the coast. It usually moves around the coast from west to east.
- Tropical cyclones are sometimes seen in the Indian Ocean in summer.
- The Western Cape receives its rain in winter while the plateau receives its rain in summer.
- 0 Temperatures over the land in summer will be higher than they are in winter. Most exams have questions on a synoptic map. You must be able to tell the difference between winter and summer maps.
Summer | Winter |
---|---|
|
|
How is the micro-climate in valleys influenced by the slope?
Micro-climatology deals with the climates of small areas. Aspect refers to the direction a slope faces, and thus to the exposure of the slope to the Sun.
The direction of the valley sides influence the angle at which the Sun's rays strike the Earth's surface. Although an equal amount of sunlight strikes each place, the sunlight striking the north-facing slope is distributed over a small area. On this slope the Sun's rays will be most effective and this slope will be warmer. The effects of aspect are more noticeable in winter when the Sun’s rays are at more of an angle. In the Southern Hemisphere the north facing slopes are warmest.
The effects of aspect on human activities.
Because in the Southern Hemisphere south-facing slopes are cooler there is less evapotranspiration. In the Natal Midlands the south-facing slopes are often wooded while the warmer north-facing ones consist of grass. In South Africa traditional communities prefer the warmer north-facing slopes of the escarpment rather than the valley floors and the south-facing slopes. In cities north-facing slopes are more popular for residential areas. In Europe agricultural activities are usually confined to the warmer south-facing slopes.
What weather phenomena are associated with the micro- climate in valleys?
- In the morning, air above the valley slopes heats up more than air on the valley floor. Warm air rises towards crests, causing up-slope winds.
- Later in the day, with more heating, air from the valley floor becomes less dense and rises, causing an up-valley anabatic wind.
Anabatic and katabatic winds
Valleys produce their own winds due to unequal heating of the valley slopes during the day
During the day
During the night
- As a result of terrestrial radiation, air on the high slope sides cools, becomes denser and flows down the valley sides to form a down-slope wind.
- Later in the night, the air in the upper part of the valley cools, become denser and starts to flow down the valley. This causes a down-valley katabatic wind.
- If the dovim-valley flow is not fast, frost and fog may develop, particularly in hollows.
These winds, although usually gentle, affect the microclimates and human activities. For example, along the slopes in the Fra_nschhoek valley rows of dense hedges are planted to obstruct the dovimward flow of cold air and keep it away from the vineyards below. During the dry season both anabatic and katabatic winds may become dangerous in the spread of bush and forest fires.
lnversions and frost pockets
- On calm, clear, winter nights the air on the high ground on the sides of the valley is cooled by terrestrial radiation (night time cooling).
- The cold, more dense air sinks down the valley sides and collects on the floor of the valley, sometimes causing a frost pocket.
- The warm air that was on the valley floor rises onto the middle slopes of the valley, causing a thermal belt of warmer air.
Radiation fog
- Radiation fog, typically found in valleys is formed when nights are cold, clear and cloudless.
- Under such conditions the Earth’s surface and the layer of the atmosphere in contact with it cool rapidly.
- If the dew point temperature is reached, condensation occurs and many minute droplets are formed and are suspended in the air.
- Fog on the valley floor disappears rapidly during the course of the morning after isolation starts, when the Earth radiates heat into the atmosphere.
Utilisation of valley floors
- Valley floors are often popular sites, because of their level topography, agricultural land and the availability of water. Frost hardy plants are grown on valley floors while sensitive plants are grown on the valley sides. Settlements develop in the thermal belt, which is the warmest part of the valley and its sides.
- Nocturnal inversions and katabatic airflow in valleys tend to create pollution in cities as the pollution cannot escape.
What are the differences and the reasons for the differences between rural and urban climates?
What is an urban heat island?
- A heat island is the hotter area of a city surrounded by the cooler urban fringe and rural areas.
- The higher urban temperatures cause an urban heat island to develop over the city. This heat island reaches its greatest intensity above the city centre and diminishes towards the suburbs. Within this heat island the air is less dense and begins to rise. Cooler air from the suburbs moves in to replace this.
- Urban heat islands exist throughout the year, but their effect is more pronounced at night and in winter when temperatures are lower. This is also the situation when there is an anticyclonic subsidence of air, which often happens in southern Africa in winter.
What effects do urban heat islands have?
- Increase human discomfort especially in summer.
- Cause heat stress and deaths during heat waves.
- Increase conditions suitable for the spread of disease caused by insects such as mosquitoes and fleas.
- Reduce visibility due to smog, particularly in winter.
- Increase smog.
- Increase air conditioner use leadingto release of more heat and greenhouse gases, which degrade local air quality
- Increase biological activity, for example, growing season length, which is positive.
- Reduced ice and snow in winter, which is positive
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What is a pollution dome?
A pollution dome is a mass of polluted air in and above a city or industrial area. This air is prevented from rising by the presence of an inversion above it. If there is a wind, the pollution will be carried downwind to form a pollution plume.
What are the effect ofa pollution dome on people and the environment?
Urban pollution has both seasonal and long-term effects on humans and the environment.
- Lead poisoning may result from petrol fumes and old paint peeling off buildings.
- Respiratory discomfort and asthmatic attacks may increase due to smoke emissions.
- The pollutants tend to increase cloud cover and precipitation.
- Insolation is reduced by pollution, especially in the morning when the Sun’s oblique rays have to penetrate an even thicker layer of pollution.
- The pollutants cause smog, which contributes to higher temperatures, reduces visibility and is harmful to humans and plant life.
- The release of oil and coal combustion emissions in the air forms acid rain. This pollutes rivers and lakes, causes damage to buildings and kills plants and fish.
- Increased use of fossil fuel powered plants also increases emissions of greenhouse gases, such as carbon dioxide (CO2), which contribute to global climate change.
How can the heat island effect be reduced?
The reduction of the urban heat island effect depends on a number of factors. Some of them are within and some outside of a community’s control. Climatic conditions and the relief cannot be changed. Decision makers can select energy-saving strategies that will create a healthier and more sustainable environment. Creating urban green spaces like parks and roof gardens, appropriate building design and public transport, can all contribute to reducing urban heat islands.
Running water on the surface of the Earth is the most dominant agent of change in the physical landscape. The study of the relief features shaped by running water, for instance mountains, hills, floodplains, valleys and waterfalls is known as fluvial geomorphology. A fluvial geomorphologist studies everything in connection with rivers, from the pebbles in the river bed to the velocity of the water flow, to determine the condition of the river.
What are the characteristics of drainage basins?
The drainage basin acts as a system with inputs, flow, storage and outputs. Water and sediment move through the system. A drainage basin is the total area of land surface drained by a stream network
Features of a drainage basin
The main features of drainage basins are illustrated in Figure 35 and defined in the Table below
catchment area | The area over which rain falls that is caught by a drainage basin |
river system | A main river with all its tributaries |
watershed | An area of high ground separate two drainage basins |
tributary | A river that joins another leger river |
river mouth | Sea or lake where the river ends |
source | Where the river ends |
confluence | The place where two rivers join |
water table | upper level of underground saturated rock |
surface run-off | The surface flow of water |
groundwater | Water found under the ground |
interfluve | High lying area or spurs between two river valleys |
infiltration | Movement of water through soil into the ground |
What are the different types of rivers?
Permanent rivers flow all year round and are always in contact with the water table. The Tugela River is an example.
Periodic rivers only flow during the rainy season. They are in contact with the water table only in the rainy season. The Limpopo River is a South African example.
Episodic rivers only flow after heavy rain. These rivers are found in regions where there is low rainfall, which evaporates quickly. The Auob and N ossob Rivers of the Kalahari in Northern Cape are examples.
Exotic rivers span two types of climatic regions. These rivers usually rise in high rainfall areas and flow into dry regions The Orange River (or Gariep) rises on the eastern side of South Africa, and flows through the drier western side before it reaches the Atlantic Ocean.
What are drainage patterns?
Stream channels create a variety of drainage patterns on the surface of the Earth. By studying the stream patterns of an area, one can learn much about underlying structures and rock types
Parallel drainage pattern
Reguirements
- Recently uplifted sloping plain
- Rock type uniformly resistant to erosion
Characteristics
- The main streams flow parallel (or nearly) to each other.
- The tributaries enterthe main streams at very small angles.
Example
- Tributaries of the Steelport River in Limpopo
Dendritic drainage pattern
Reguirements
- Rock is uniformly resistant to erosion.
- Pattern is not dependent on geology.
Characteristics
- The pattern is tree- shaped.
- The tributaries join the main stream at acute angles.
Example
- Most rivers in South Africa, for example Tugela, Mooi, Umgeni
Trellis drainage pattern
Reguirements
- Parallel ranges of fold mountains or alternate layers of hard and soft rock.
- A strong main stream
- The pattern is dependent on the reliefand the geology ofthe area.
Characteristics
- Tributaries meet the main streams at right angles. The main streams cut gaps through the mountains.
Example
- Buffels River at laingsburg
Radial drainage pattern
Reguirements
- Dome-shaped hill, conical hill, mesa, butte
Characteristics
- Streams radiate outwards from a central high point.
Example
- Koffiebus,Teebus
Rectangular drainage pattern
Reguirements
- Well jointed rock with joints exposed at the surface
Characteristics
- Rivers flow in exposed joints.
- Rivers and tributaries have right angled bends.
Example
- Rivers in the Waterberg (Limpopo)
Reguirements
- A central basin or a low lying area such as a lake or a marsh
Characteristics
- Streams radiate inwards from a surrounding higher area.
- The opposite ofa radial drainage pattern
Example
- Common in the flatter parts of Namaqualand
Deranged drainage pattern
Reguirements
- Geologically young areas
Characteristics
- Haphazard pattern
- Numerous lakes and swamps
- Streams enter and leave swamps and lakes randomly.
Example
- Recently glaciated areas such as the Canadian Shield
What is drainage density?
Drainage density refers to the average length of the streams in the area of a drainage basin. Drainage density can be calculated by making use of the following formula:
Drainage density = total length of streams in the basin (km) / area of the drainage basin (kml)
Drainage density can be described as high and low :
- More infiltration will cause fewer rivers to occur, causing a low drainage density.
- More runoff will cause more rivers to occur, causing a high drainage density.
How do you identify stream order?
Drainage basins can be described and compared by means of a ranking system known as stream order. Streams without tributaries are first order streams. When two first order streams join they result in a second order stream and when two second order streams they form a third order stream and so on. When a stream of a lower order joins a stream of a higher order the higher one remains unchanged. This arithmetic process is known as geo-adding.
The following laws of stream orders show the relationship between stream order and factors such as gradient, number of streams, stream length and the size of the drainage basin
- There are more streams of a lower order than of higher order.
- The lower the stream order, the steeper the gradient.
- The lower the stream order, the shorter the length of the stream.
- The lower the stream order, the smaller the drainage basin.
What is the nature of river discharge?
River discharge is the volume of water that flows down a river. The stream flow can be either laminar or turbulent.
- Laminar flow is found where water flows over a level and even river bed. The water moves as parallel sheets (Figure 38).
- Turbulent flow occurs where the river bed is uneven and steep. The water moves in a bubbling, turbulent manner, continually changing levels (Figure 39).
What are river profiles?
A river uses energy to do its ‘work’ of erosion, transportation and deposition of sediment, and to move a body of water in its channel from its origin to its mouth. In this way, the river valley is continually deepened and widened. River profiles are described as either transverse (cross) profiles or longitudinal profiles.
What is a transverse river profile?
The transverse profile shows the shape of the river valley from one bank of the river to the opposite bank. The shape is dependent on whether vertical erosion or lateral (sideways) erosion is the dominant force. The cross profile of a river looks like a V- shape. The shape of the cross profile changes throughout the course of the river (Figure 40). It can help you to see if erosion (vertical or lateral) or deposition is taking place.
What is the longitudinal profile?
The longitudinal profile shows the changes in the altitude of a river’s course from source, along its channel to sea level. Usually the longitudinal profile has a concave shape. It will have a steep gradient at the source and a gentle gradient at the mouth.
Temporary and permanent base levels in the longitudinal profile of a river
The lowest level at which a river can erode is called the permanent base level. Sea level is called the permanent base level because the river cannot erode downwards any further. Temporary base levels such as a dam, rapids or a waterfall could be found along the course of a river. All base levels are temporary, except the sea, which is the ultimate base level.
The stages ofa river seen on topographic maps
The picture belows shows the features of the three stages of the Berg River in the Western Cape on topographic maps. In the upper course the contours are closer to each other, indicating steep slopes and short tributaries. In the middle course, the contours are further apart. The gradient becomes more gradual and tributaries are longer. The slope in the lower course is very gradual. Therefore deposition of sand, meanders and braided streams are found in this course. The river becomes wider as it flows from its source to the mouth.What are fluvial landforms?
The greater the velocity of a river, the greater the amount of energy will be available to transport material and cause erosion. Deposition of sediment takes place when the speed of the river reduces and the energy of a stream decreases. As a result, different landforms are formed, along the course of a river.
Floodplains
Floodplains are natural features of many rivers. They are flat and are on the sides of the river. Floodplains are usually found in the lower course of a river where the valley is widened by means of lateral erosion but smaller flood plains can also be seen in the middle course. When the river bursts its banks in a flood sediment is deposited on either side of the river (Figure 43). This builds up after each flood. Typical landforms of a floodplain are natural levees, meanders, oxbow lakes, braided streams and deltas.
Natural levées
During periods of overbank flooding, the coarsest material will be deposited first and this can form a natural embankment, called a natural levee, next to the river. Levées can be strengthened artificially to act as flood barriers.
Meanders
Meanders are curves or bends found along the course of a river (Figures 44 and 45). They are usually found in the middle course or lower course of a river, and constantly change their shape and position. Meanders move across the floodplain by eroding the curved outside banks.
Oxbow lakes
As erosion continues on the outside bends (undercut slopes) of the meander, the neck of the meander gets narrower. During a flood, the river breaks through the neck and shortens its course. The cut ends of the meander are sealed by deposition and a oxbow lake is formed (Figure 46). The oxbow lake may eventually dry up due to evaporation, and be filled with sediment.
Braided streams
Braided streams are streams that have many channels and islands of sediment between those channels (Figure 47). When a river does not have the energy to carry its load the load is deposited in the river bed.
Waterfalls and rapids
Waterfalls and rapids are usually found in the steeper upper course of a river. A waterfall forms when a river, after flowing over hard, resistant rock, meets a band of softer, less resistant rock. The river erodes the softer rock faster than the harder rock ' maller scale versions of waterfalls.
Deltas
When a river reaches the sea or a lake it slows down, loses energy and deposits its load. If the load of sediment cannot be carried away by tides and ocean currents a delta is formed. Layer upon layer is deposited until the sand and mud may build upwards and outwards to form a roughly triangular delta. No South African river forms a visible delta as the tides and currents remove the sediment before it can settle.
What is river grading?
A graded river is in a state of equilibrium and neither erodes nor deposits. A graded river has a gently sloping, concave profile. The river illustrated in Figure 49A has an ungraded profile, because it contains a waterfall and a lake. These are temporary bases of erosion. Erosion will exceed deposition at the waterfall, and deposition will exceed erosion at the lake.
What is river rejuvenation?
River rejuvenation takes place when there is an increase of a river’s speed and erosive power. The rejuvenated river erodes a new valley in the old one (Figure 50).
Causes of rejuvenation
River rejuvenation may develop as a result of:
- a worldwide lowering of sea level
- raising of the land through forces in the Earth’s crust
- a significant increase in rainfall
- a rapidly flowing tributary that joins the main stream
- river capture where the increased volume of water enlarges the erosion capacity of the stream.
Landforms associated with rejuvenation
Knickpoint
A knickpoint is a break in the slope of a river profile caused by a rejuvenated river. There is often a waterfall, called the knickpoint waterfall, at this point. Augrabies Falls on the Orange River (Gariep) is a knickpoint waterfall.
Terraces
When rejuvenation of a river flowing on a wide valley floor occurs, a new valley is carved into its own floodplain. This produces steps on either side of the valley. These are terraces, and they often occur in pairs on either side of the valley (Figure 51).
Incised meanders
An incised meander is a deep, steep-sided meander (bend) formed by the severe downwards erosion of an existing meander. Such erosion is usually brought about by the rejuvenation of a river. Incised meanders form when rejuvenation occurs in a stream which is already meandering.
What is river capture or stream piracy?
River capture (stream piracy) occurs when a powerful river cuts back at its source by headward erosion and captures the headwaters of a neighbouring river. This often occurs through a process of abstraction.
Abstraction
Abstraction occurs when the stream on one side of the watershed is a more energetic stream than the stream on the other side, because it runs down a steeper slope. More rapid erosion of the steeper slope causes the watershed to move (Figure 52).
In South Africa abstraction occurs mainly in the Drakensberg, where the rivers of KwaZulu-Natal flow eastwards down a steep gradient over a distance of 200 km to the Indian Ocean. The westward flowing Orange River flows along a more gentle gradient over approximately 2 000 km to the Atlantic Ocean.
Figure 52 Abstraction due to more rapid erosion ofa steep slope. Rivers A and B flow on opposite sides ofthe watershed. Because river B flows down a steeper slope than riverA, river B will be more energetic, and therefore causes erosion to be faster. The watershed moves from position 1 to position 2. As a result, the drainage basin ofthe more energetic stream (B) grows.
River capture
River capture occurs where a river cuts through a watershed and intercepts a river flowing on a higher level. An example of this is the kunene River in Namibia. The Kunene used to flow to the Etosha pan, but was intercepted in its middle course by an eastward eroding river from the coastal plain to the picture below :
What are the features associated with river capture?
The following features are associated with river capture (Figure 54).
- The captor stream is the river which captured the waters of the other river.
- The river whose waters were captured is called the captured stream.
- The stream that has lost its water now flows in a valley that is too big for the stream. This stream is called the misfit stream.
- The elbow of capture is the place where the stream piracy has taken place.
- The wind gap is the dry river valley with river gravel between the elbow of capture and the misfit stream.
What are superimposed and antecedent drainage patterns?
You have already learnt that drainage patterns are influenced by the hardness or softness of the underlying rock and the patterns of faults or fractures in these rocks. Sometimes the drainage pattern does not relate to the rock structures or landscape over which it flows. When this occurs, it is due to superimposed drainage or antecedent drainage. The difference between superimposed and antecedent drainage is that the superimposed stream is younger than the structure through which it flows while the antecedent is stream is older.
Superimposed drainage patterns
Superimposed drainage exists where a river established its course in rock layers which have been removed by erosion (Figure 55). The stream which subsequently imposed its course on underlying rocks of a completely different nature is called a superimposed stream. Superimposed streams are younger than the structures through which they cut.
Antecedent drainage patterns
An antecedent stream existed on an earlier landscape that was subsequently raised. The stream was able to maintain its original course, in spite of uplift or the formation of a mountain or ridge from below. The stream cut through the obstruction as it was formed. The uplift may be due to folding, faulting or warping. The term antecedent refers to the fact that the course of the river developed before the uplift occurred (Figure 56).
Management of catchment areas (the area over which rain falls that is caught by a drainage basin) and rivers occurs when people try to control or alter the natural flow of water.
Why is managing drainage basins and catchment areas important?
- Drainage basins are managed for irrigation purposes.
- It is important to manage river flow by building dams to ensure a permanent source of water.
- Rivers need to be managed to provide flood control. This can be done by preventing settlement below the flood line, by building dams, or by diverting water away from settlements.
- Catchment management is necessary to protect water resources and make water use sustainable.
- Rivers can be used for recreation, like water sports. caravan parks and holiday resorts are also sometimes found along rivers and next to dams.
- Management is needed to control pollution.
What are the impacts of people on drainage basins and catchment areas?
- River water is polluted by industrial effluent, agricultural run-off and untreated sewage.
- The nature of run-off can be changed by building dams.
- Removal of vegetation can lead to flooding.
- Cities and other structures built on the floodplain of the river decrease infiltration. This can lead to flooding in urban settlements.
- Swamps, which serve as sponges during flooding, are drained.
- The ecology of rivers and their catchment areas is disturbed by the removal of water for irrigation, industry, mines and domestic use.
- Meanders can be eliminated by means of channels.
- Inter-basin transfer of water involves the transfer of water from areas with a water surplus to those with a water shortage.
What is the concept of settlement?
A settlement is a group of people who live, work and interact together in a cluster of building structures, interlinked by communication.
Nature of settlements
A settlement may be as small as a single house in a remote area or as large as a huge city. A settlement may be permanent or temporary. An example of a temporary settlement is a refugee camp. However, a temporary settlement may become permanent over time.
Site
Site is the land on which a settlement is built. Early settlers were looking for water supply, fuel, farming land, shelter and defence (Figure 57). Ideal sites tended to be:
- I flat or gently sloping
- well drained (not marshy) and free from any risk of flooding
- close to a permanent water supply
- sheltered from strong wind
- steep-sided hills.
Situation
Situation is the location of a settlement in relation to the surrounding area (Figure 58). A settlement with good access to natural resources and to other settlements will grow in size. At a larger scale, towns grow and prosper from a favourable situation.
What are the differences between rural and urban settlements?
A rural settlement is a single function settlement where most of the people are engaged in a primary economic activity, usually farming. This may range from large commercial farms to small subsistence farms and is described as unifunctional.
>An urban settlement is a multifunction settlement and consists mainly of people engaged in secondary and tertiary activities. Urban settlements are characterised by more numerous, larger and more densely position buildings and more complicated infrastructure. They are multifunctional.
Settlement classification according to size, complexity, pattern and function
How do site and situation affect the location of rural settlements?
What factors influence the choice of site?
Originally settlements had to be at good defensive sites and satisfy the basic needs of its inhabitants. These basic needs are:
- The availability of drinking water. This could be from rivers or springs.
- The availability of building materials. This would mainly be trees but includes rocks and thatching grass.
- Closeness to arable land. The inhabitants need to have fertile soils to grow their crops.
- The availability of transport routes.
- Pasturage for livestock. Their cattle, goats or sheep have be able to graze.
- Fuel for warmth and cooking. This would usually be from trees but in many treeless areas cow dung is used as a fuel.
Classification of rural settlements according to pattern and function
Pattern
Rural settlements can be either nucleated or dispersed.
Dispersed or isolated rural settlements
These occur where isolated farmsteads are located each on its own land and sometimes kilometres from its nearest neighbour.
Nucleated (clustered) rural settlements
A nucleated (or clustered) rural settlement pattern comprises a denser group of dwellings and other buildings. In farming villages the farmers usually live as a group in a central village and work in the surrounding fields by day. The buildings are usually clustered around a central point such as a water point.
Function
All settlements except the very smallest have a variety of functions. In rural areas the main functions of settlements have been:
- to provide agricultural services, including a market for produce, and so they become transport centres
- to provide a place for defence in times of war.
Round and square villages
Square or round settlements have houses clustered around a focal point, which is the centre of importance for that community. This may be a well, kraal, church, market square, or village green.
Linear villages
Linear settlements are a combination of dispersed and nucleated patterns. The farmsteads are arranged close to one another on both sides of thoroughfares such as roads, rivers, valleys and railway lines The properties in linear villages are long and narrow and have a narrow front along the central thoroughfare.
T-shaped and cross-road villages
Cross-road settlements can be T-shaped settlements or star-shaped. They are found at road junctions.
Land use in rural settlements
- the purpose for which land is used.
Land use in rural areas has different features from that in urban areas. Some of these
are:
- residences for country workers, commuters and seasonal workers
- farming and forestry
- natural resources development of minerals, water supply.
What are the characteristics of rural land use?
Land use refers to the function of an area of land
What is rural—urban migration?
The percentage of people living in cities increases steadily through rural—urban migration. Poor harvests, lack of money and inadequate services are ‘push’ factors that encourage people to move away from rural areas. The possibility of paid employment, better education and healthcare ‘pull’ people to cities.
The cycle of poverty illustrated in Figure 61 explains the situation which traps many rural populations with declining economic prospects.
What are the causes and consequences of rural depopulation on people and the economy?
The period of rapid urbanisation is caused mainly by the attraction of industrial jobs, which causes rural depopulation. Movement to the city is partly due to ‘rural push’ (repelling action) and partly due to ‘urban pull’ (attraction). These are summarised in Table 16.
What are the effects of rural depopulation and the strategies to address them?
Central place towns that are accessible to rural areas depend on the buying power of the farming population. Reduced spending in towns means that many shops and businesses in these towns cannot survive, and they close. Employment opportunities decrease and more people migrate to cities. The rural landscape gradually becomes depopulated. The downward cycle of rural poverty starts. Stopping, preventing and reversing this trend involve a highly organised system of planned, co-ordinated action on the part of the government, local authorities, and business.
What are the social justice issues in rural areas?
Access to resources
Poverty and lack of access to resources hinder access to social justice in rural areas worldwide. In order to alleviate rural poverty, the present government aims to develop viable co-operative businesses for small-scale farmers. Linking small-scale farmers with commercial farmers enables them to participate in both the domestic market and the lucrative global markets.
Land reform
In South Africa, land is a highly contested resource. On the one hand, private ownership of productive land favours a racial minority, while on the other hand there is a need to strike a balance between ownership and the benefits from use of land. The current South African government aims to alleviate poverty, especially in rural areas, by transferring land ownership to the millions of South Africans who have been denied access to this economic resource. It intends to achieve this objective through land reform programmes.
What are the origin and development of urban settlements?
- Urbanisation of the world’s population On a global scale towns and cities are expanding rapidly. By 1995 over 45% of the world’s population lived in urban areas. In most MEDCs over 70% of the population lives in towns and cities. By contrast, in many African and Asia LEDCs, only 33% of people are urban dwellers.
- The growth of towns and cities Urbanisation in MEDCs began as a result of the Industrial Revolution during the nineteenth century. People migrated from the countryside to the towns looking for work in factories. Over time, towns expanded to become cities. Urban growth is the physical expansion of tovims and cities.
How do site and situation affect the location of urban settlements?
A combination of physical factors making up the site and human factors determine where urban settlements are located.
Physical factors
The physical factors affecting the development of a site for urban settlement include:
- availability of fresh water
- underlying rock and soil structure
- relief
- too steep slopes make building difficult, therefore flat land is preferred
- drainage — flooding is avoided
- aspect of slope — slopes facing the Sun are warmer (north facing slopes in the Southern Hemisphere and south facing slopes in the Northern Hemisphere)
- resources — minerals will encourage industrial development.
How can urban settlements be classified according to function?
Examples of settlement functions
Central places — A central place is an urban settlement that provides urban services for the surrounding rural community. For example, Upington provides services to people living in the sparsely populated Northern Cape. Ermelo and Cradock serve as centrally located markets and service centres for the surrounding farming areas.
Trade and transport settlements
Break of bulk points — Locations where one type of transport is replaced by another. For example, Durban harbour, where goods which have been transported by road or rail are loaded on board ships, and the other way around.
Specialised cities — Centres with one dominant function and the location of the centre is decided by the occurrence of natural resources such as fish, minerals, timber, agriculture or tourism, for example, Plettenberg Bay.
Iunctions towns — Urban settlements that developed at important transport junctions such as river crossings, railway and road junctions. Iunction points occur at junctions of rivers, rail routes and roads. For example, De Aar (Northern Cape) is a road-rail junction.
Gateway towns or gap towns — Gateways are natural gaps or passes through physical obstacles such as mountains. Roads converge at a point to make use of the gap. For example, Worcester (Western Cape) is situated near the Hex River Mountains Pass leading to the Karoo.
What are the origin and development of urban settlements?
What is urban hierarchy?
Urban hierarchy
The term ‘hierarchy’ refers to the arrangement of a settlement in a sequence or order of importance. At the bottom of a settlement hierarchy there are many low-order rural settlements, like villages, which offer few services. At the top of the hierarchy there is likely to be one high-order urban settlement, like a city, which will provide many specialised services.
Central place
Most urban settlements are central places supplying urban services to their surrounding rural communities
Threshold population
The minimum number of people required to support a shop or a service so that it remains profitable is called the threshold population. Large shops selling luxury items require a large threshold population while small shops selling convenience goods such as bread and milk have a low threshold population. A primary school has a lower threshold population than a high school.
Sphere of influence
The area that people travel from to use a shop (or service) is its sphere of influence, sometimes called the catchment area. Shops with a large sphere of influence depend on good transport links to bring shoppers to them. A primary school has a smaller sphere of influence than a high school.
Range of goods
The range of goods is the maximum distance people are prepared to travel to use a shop or service. People will travel further to buy a luxury motor car than they will to buy bread and milk. Low-order services will have small threshold populations and small range. A primary school has a smaller range of goods than a high school.
What are lower and higher order functions and services?
Functions and services are activities provided to meet people’s needs. Examples include shops, schools, banks and sports centres. These shops and their services can be hierarchically organised and ranked from lower order functions to higher order functions (Figure 63). There is a direct correlation between population size and the range of services offered by settlements. Larger settlements offer a wider variety of services within a broader range than smaller settlements.
What are lower and higher order centres?
There are more numerous lower order centres (smaller towns) and fewer higher order centres (large cities). Smaller towns have smaller populations, fewer services, more low order businesses and smaller ranges. Large cities have large populations and larger numbers of services, including many high order businesses with large ranges. A settlement’s position on the hierarchy is determined by the number of functions and not only by the size of the population.
What are the origin and development of urban settlements?
Land use zones
Urban areas are not random developments, but have internal structure. If you walk through a town or city you will often find distinct land use zones. Each area (or zone) of a city has a distinct function, for example housing or industry. A study of land use maps shows that the different land use types are not distributed in an urban area in an arbitrary manner or in a disorderly way but in patterns, as Figures 64 and 65 show.
Urban profile
The urban profile shows a cross-section of the city from the CBD to the periphery (Figure 66). Most urban profiles show a concentration of high buildings surrounded by low buildings as you move towards less built-up areas. Together these form the morphological structure of a city.
What are the factors influencing the morphological structure of a city
The major factors influencing the morphological structure of a city are various physical factors, planning and transport.
Physical factors
- Relief — Cape Town developed between Table Mountain and the harbour. The steep slopes of Table Mountain and the coastline determined the structure of the city. Pretoria lies between Magaliesberg and Daspoort mountains and has a linear shape.
- Microclimate — Local climate also influences the form of an urban area; warmer north-facing slopes are preferred.
- Soil conditions
- Fertile soils attract settlement.
Planning
- Planned cities — These cities are planned and are built as one unit and have an ordered structure and a modern street plan, for example Sasolburg.
- No planning
- An urban area developed quickly, like in the case of Kimberly, or sometimes it is an ancient city. The cities have no specific city centre or street pattern.
- Piecemeal planning — Settlements in which each new suburb may have a different appearance, but there is evidence of urban planning. Most South African cities are examples of piecemeal planning.
Transport
Transport plays a vital role in the development of a city’s structure. As transport systems improved and more people were able to buy cars, the towns became less compact. People could live away from the city centre and commute to their work places. As a result of this, urban sprawl is evident along the transport routes in many cities.
Models of urban structure
Urban land use is often explained by models. A model is a simplified theory that attempts to explain how things work. No model works perfectly but they do help to explain some of the features of urban structures. There are a number of these models: the concentric zone model, the sector model, the multiple nuclei model, the modern American-western city, the Third World city and the South African city.
The concentric zone, sector and multiple nuclei models
The modern American—western city
The modern American—western city is a type of city that developed as a result of rural- urban migration and the development of the motor car. Most of its population now move from the CBD to the suburbs. This causes commercial decentralisation. Unlike the Third world city, most of the economy generated in the modern American city is in the formal sector.
The Third World city
Cities in developing countries tend to develop their own distinctive pattern described by the Third World city model (Figure 68). This differs in several ways from the land use model in developed countries. There is rapid growth due to large scale rural-urban migration and high rates of natural population increase.
The South African city
The South African city model is unique and has a different set of characteristics from those of other countries in the world. Apartheid policies and laws like the Group Areas Act produced an unnatural system of urban land use in cities. The Group Areas Act divided South African cities into racial areas (Figure 69). It was illegal for designated groups to live or own land in certain areas. Black people were forcibly removed from their homes into outlying townships. With the democratic elections of 1994 the landscape of the South African cities started to change. Now all people can reside in any area irrespective of their racial identity.
Changing urban patterns and land use in South African cities
Changes in the CBD
As a city’s size increases, the CBD grows and becomes progressively differentiated into land use subzones (for instance, retailing, finance, administration, entertainment). Dynamic change in the CBD is constant, through extension, replacement and regeneration. The CBD expands into the surrounding area of old homes and service industries occupying these old homes — the zone of transition. This is known as the principle of invasion and succession.
Urban retailing
The CBD used to be the most important retail area and most employers favoured this land use zone. In time, the CBD and the suburbs became more divided, resulting in commercial decentralisation. Neighbourhood shopping centres were established in the suburbs. The major forces causing this change were the following:
- increase in urban populations
- the centrifugal expansion of suburbs
- changes in shopping habits and greater mobility.
Residential changes in South Africa
When buildings in a city are unsuitable for use in the present time, often they are not demolished completely. Instead, the front structure of the building is retained and new structures are built behind the original facade. This allows the old city structure to exist while the building is improved. The process is known as facadism. Sometimes old houses that are close to the city are improved and modernised. This is called gentrification.
Recent urbanisation patterns in South Africa
There is a change in the demographic profile of South African cities. Cities attract skilled workers and increasing numbers of the youth who make up most of those who are unskilled, economically inactive and in search of employment. A corresponding change is taking place in rural areas. These areas are mostly former homelands, with limited economic activity. They are characterised by outward migration and a decline in the young population.
The CBDs in South Africa have also seen changes with new shopping centres and altered transport projects, for example the Gautrain and Bus Rapid Transport in big cities. The CBDs have changed because of the decline in the number of people visiting the city centre. Many shops have moved to suburban shopping centres that are further away. People avoid traffic congestion and air pollution.
There also has been competition to use the land on the rural-urban fringe. The main reasons for this are that at the rural-urban fringe land is less expensive, there is less traffic congestion and air pollution, and the environment is relatively unspoilt. In South Africa we have seen a number of office developments and high technology business parks developing on the rural-urban fringe.
What are the issues related to rapid urbanisation?
It is very important to plan for the future of urban growth. In South Africa about 60% of the population is urbanised. With rapid ongoing urbanisation and expansion of cities urban areas are experiencing a greater demand for employment, basic services and infrastructure. These problems get worse as the city grows and are often worse in the CBD.
Lack of planning
Lack of planning can lead to unhindered growth of cities, or urban sprawl. Urban sprawl can occurs when there are no laws to control what and where people can build, such as in South Africa’s informal settlements.
Housing shortages
One of the major challenges that urban municipalities face is providing housing for existing and growing urban populations. The constitution of South Africa says that everyone has the right to have access to adequate housing. Despite having delivered about 220 ooo houses a year, South Africa continues to face a major challenge in providing affordable accommodation in sustainable settlements. A shortage of housing means many people have no alternative but to live in informal settlements.
Overcrowding
Overcrowding is one of the major problems for most urban areas. Urban areas are not ready to accommodate all the people migrating from the rural areas and some from neighbouring countries. Some of the migrants into the cities are not skilled enough to be employed in the formal sector and find it difficult to get employment.
Traffic congestion
Large cities invariably suffer from congestion on roads. All kinds of conveyances
Problems with senlice provision
South African cities face a problem of service provision. The greatest demand for services and infrastructure is mainly at the former low-income residential areas and informal settlements that lack clean drinking water, electricity, healthcare facilities, sanitation, solid waste disposal, housing and safe, reliable and affordable transport systems.
Growth of informal settlements and associated issues
A major problem in African cities is the inability of the governments to provide adequate and affordable housing. The majority of residents do not have access to formal housing and related amenities, and generally live in informal settlements without service provision. Informal settlements are not planned therefore lack services.
How are urban areas in South Africa managing urban challenges?
Urban settlements in South Africa are not static, they change over time. As South African cities have a history of apartheid, there now is rapid urbanisation and some urban settlements have been planned on new sites. Such cities are called ‘new towns’. New towns are urban settlements planned and built to ease the housing shortage in existing towns and cities. New towns include garden cities, edge cities and green belt cities. In these settlements all aspects of development are determined before construction begins. The ultimate aim is to provide not only access to services and amenities, but also to achieve environmental, economic and social justice and individuals and communities.
What are economic sectors?
The primary sector
The economy of the country is made up of a number of economic sectors. The primary sector extracts or harvests products from the Earth or the sea. This includes farming, forestry, fishing, mining and quarrying.
The secondary sector
The secondary sector manufactures finished goods from products produced in the primary sector. All manufacturing, processing and construction lie within the secondary sector. Activities associated with the secondary sector include metal working, engineering, food processing, textile production and the chemical industries.
The tertiary sector
The tertiary sector of the economy is the service industry sector, providing services to the general population and businesses. Activities associated with this sector include retail and wholesale sales, transportation and distribution, entertainment, restaurants, tourism, insurance, banking, healthcare, and law.
The quaternary sector
Quaternary sector activities provide information and expertise with an emphasis on information and computer technology. It includes data processing, use of geographical information systems (GIS), consulting and research. It is a very small sector and is often included in the tertiary sector.
An example of how the sectors are linked
- A farmer produces wool from sheep
- primary activity.
- The factory makes the wool into a jersey
- secondary activity.
- The factory uses the railways to transport the jerseys to the shop and the shop sells the jersey to a consumer. The shop uses a bank and its premises and stocks are insured. These are all tertiary activities.
- The shop employs a computer company to use a geographic information system (GIS) to determine the range of goods and location of competitors. This is a quaternary activity.
What are the economic sectors’ contributions to the South African economy?
The gross domestic product (GDP)
The gross domestic product (GDP) is one of the main indicators used to measure the size of a country’s economy. It represents the total value of all goods and services produced over a specific period.
GDP and development
If a country is highly developed, only a small proportion of the population is employed in the primary sector, considerably more people are active in the secondary sector, while the majority are involved in the tertiary sector. In developing countries the economically active population is engaged mainly in primary activities, while a smaller percentage of the workforce is employed in tertiary and quaternary activities.
The changing nature of South Africa s economy
The below image shows how South Africa’s economy has changed in the last 100 years, from a less economically developed country to one that is now more highly developed. A greater proportion of the economically active population is employed in the tertiary sector, and proportionally fewer people are employed in the primary sector.
How can we use graphical and statistical information about the economy?
Graphs of employment in various sectors through time (like Figures below) can be used to study comparative levels of development and economic growth.
Agriculture
What is the contribution of agriculture to the South African economy?
Agriculture contributes a small and declining share to South Africa’s GDP. Agriculture is an important economic sector because it provides income and food for the population. Agriculture is a significant provider of jobs, especially in the rural areas, and a major earner of foreign exchange. South Africa exports more food than it imports.
The contribution of agriculture to the economy consists mainly of four factors:
- direct contributions to gross domestic product (GDP)
- supply of food to the population
- contributions to the country’s balance of trade
- employment of workers.
Figure 70 shows the steady decline of agriculture’s contribution to the South Africa’s GDP, from 15% in 1955 to 2,4‘)/0 in 2010. This does not mean that agriculture is decreasing in importance. It means that the other sectors, especially the tertiary sector, are growing faster than the agricultural sector.
1.1 Direct contribution of agriculture to the gross domestic product
In 2011 the contribution of agriculture to the GDP was approximately R64 billion. The agricultural sector has grown by an average of 12% per year since 1970, while the total economy has grown by 15% per year over the same period. This resulted in agriculture’s share of the GDP dropping from 8% in 1970 to 2,40/0 in 2010.
1.2 Supply of food to the population
South Africa is one of the few countries in which agriculture is able to supply enough food for the population, although food prices are rising quickly. South Africa produces more than is needed for domestic consumption.
1.3 Contribution to the country's balance of trade
Normally about 25% of South Africa’s field crop production and 34% of horticultural (fruit and vegetables) production is exported. Almost the whole wool clip is exported. About half the exports are in processed form and agricultural exports are about 10% of South Africa’s total exports.
1.4 Employment
Employment in agriculture reached its peak in 1971, when 1 639 ooo people worked on commercial farms. Since then, like most agricultural countries, in South Africa machines have replaced human labour in many processes. The agricultural employment figure in 2011 dropped to 406 ooo — a loss of over 1,2 million workers. The development of more and better machines and larger farms to use them on contributed to this.
What are the roles of small-scale and large-scale farmers?
2.1 Large-scale commercial farming
Large-scale farming is the production of crops for sale in retail outlets such as shops. In commercial farming crops such as wheat, maize, sugar cane, fruit, vegetables and meat are sold all over South Africa and on world markets. The main objective of commercial farming is to make a profit.
2.2 Small-scale subsistence farming
Subsistence farming is a form of small-scale farming, usually intensive, in which nearly all of the crops or livestock raised are used to maintain the farmer and the farmer’s family, leaving little, if any, surplus for sale. The work is usually done by family members, often women, children and the elderly.
What are the main products produced for home and export markets?
Maize
Maize is the country’s most important crop. It is the basic food for many people, it is used as a livestock feed, and is an important crop for both the home market and the export market. Maize is grown commercially on many farms, mainly in North-West, Mpumalanga, Free State and KwaZulu-Natal, where there is summer rainfall of at least 500 mm per annum.
3.1.1 The importance of maize to South Africa
- Maize is an important part of the South African diet.
- Maize is also eaten indirectly through its use as an animal feed in chicken, cattle and pig farming.
- It is used in the production of food products such as beer, cheese spreads, instant coffee and many others.
- It provides direct employment to about 20 000 people and their families.
- It consumes products from other industries, such as fertiliser, irrigation equipment, herbicides, fuel and farm implements.
- It earns valuable foreign exchange.
- It provides the staple starch for millions of people depending on subsistence farming.
3.1.2 Trade balance
The quantity of maize produced varies from year to year. In good years maize is exported. It is imported in years when the rainfall is low.
Wheat
South Africa’s annual wheat production has remained more or less steady since the 1970s, ranging from about 1,5 to 2 million tons. The winter rainfall areas of the Western Cape and the eastern Free State with late summer and early summer rainfall produce nearly all of South Africa’s wheat. Most of the wheat is grown on highly mechanised, large-scale, commercial farms.
3.2.1 The importance of wheat to South Africa.
As urbanisation increases bread consumption rises. Migrants to the city cannot grow maize as they can in the rural areas and bread takes the place of maize in the city. All our bread and pasta is made from wheat, so it is a very important crop. Wheat farmers employ about 25 000 workers and buy fuel, fertiliser, machinery and seed. Recently South Africa has been importing wheat.
3.3 Sugar cane
Sugar cane is grown by 35 300 large-scale and small-scale farmers in the wetter areas of KwaZulu-Natal and southern Mpumalanga lowveld. More than 33 000 are small scale growers producing nearly 10% of the total crop. With the growth of economic development and empowerment of pre\n'ously disadvantaged people, the participation of black farmers in sugar cane production is increasing constantly.
3.3.1 Exports
Sugar is a major export crop. No sugar is imported and the value of exports is about R1—2 billion annually.
3.4 Fruit
Fruit is grown all over South Africa where there is enough rainfall or irrigation water is available. South Africa is the third largest exporter of oranges after Spain and the USA.
- Sub-tropical fruit such as bananas, mangoes and avocado pears are grown in the warmer regions of KwaZulu-Natal, Mpumalanga and Limpopo.
- Citrus fruit such as oranges and grapefruit are important in the Western Cape, Eastern Cape and Limpopo.
- Deciduous fruits such as apples, peaches and grapes are grown all over the country but mainly in the Western Cape.
3.5 Animal products
Poultry, mainly chickens, is our largest single agricultural product. They are reared near all the main towns. Sheep, for wool and mutton, are kept in the drier, western half of the country. Beef cattle are ranched in the better-watered eastern parts of South Africa. Dairy cattle are reared near the main urban centres.
3.6 Import and export of agricultural products
Table 17 shows our main agricultural imports and exports.
What are the factors that favour and hinder agriculture in South Africa?
4.1 Favourable factors
- Climate: South Africa has a range of climates making it possible for many different crops to be grovim.
- Trade: Trade with other countries has benefited our farmers.
- Tradition: There has been a long tradition of agriculture in South Africa and some of our farmers are amongst the best in the world.
- Land ownership: Most of our commercial farmers own their land, which makes it easy for them to get agricultural development.
4.2 Hindering factors
- Climate: Three-quarters of South Africa has below 500 mm of rainfall annually. This is the minimum for successful crop growing.
- Soils: Many of South Africa’s soils are infertile and large parts of the country are too steep for crop growing. South Africa has one of the worst soil erosion problems in the world.
- Trade: Many countries including USA, China and European Union countries subsidise production of their farm products making it too expensive to sell food to these countries.
- Land ownership: Apartheid laws meant that black people were not allowed to own farms in most of the productive areas. This is only slowly being reversed.
The importance of food security in South Africa
Food security exists when all people at all times have access to sufficient, safe, nutritious food to maintain a healthy and active life. Access to food is vital since it is essential to well-being and human development.
5.1 Factors influencing food security
- Droughts and floods: Adverse weather raises the price of food in the shops for all consumers, but the poor, at or below the poverty line, are the most affected.
- Economic problems: South Africa has struggled to create job opportunities to allow people to live above the poverty line.
- Mismanagement and poor governance: Money that should go towards job creation and agricultural development often has been stolen by corrupt people.
- HIV and Aids: This is of concern because of the negative effects on the people involved in agricultural production.
- Poverty: People without money cannot buy food. Population growth: More people means less land to grow food on and existing land is over-utilised.
Mining
1 What is the contribution of mining to the South African economy?
South Africa is the world’s biggest producer of platinum, and one of the leading producers of gold, diamonds, base metals and coal. South Africa holds the world’s largest natural reserves of gold, platinum-group metals (or pgms), chrome and manganese, and the second-largest reserves of zirconium, vanadium and titanium.
Even though the relative contribution of mining to South Africa’s gross domestic product has declined over the past 20 years mining remains a cornerstone of the economy. This can be seen in Figure 74.
What is the significance of mining to the development of South Africa?
The Important Of Mining To South Africa
- Exports- 2011 value of mining exports was over R224 billion, over half of South Africa's total exports.
- Cities- Cities have developed in the mining regions, especially in Gauteng and Free State.
- Eskom and Sasol- Coal generates over 90% of South Africa’s electricity. Sasol produces 30% of our liquid fuels such as petrol. Much of our plastic is made from coal.
- Technology- Deep mining is a difficult and dangerous job. Advanced technology has been developed in South Africa to minimise these risks.
- Taxes- The mines pay large amounts of tax, which helps the development of the country.
- Infrastructure- The income from mining has funded the development of South Africa's infrastructure such as roads, railways and harbours. Ports at Richards Bay(coal) and Saldanha Bay(iron ore) were built especially to handle mineral exports.
- Manufacturing- Our minerals provide the raw materials for the important manufacturingindustry. Many factories provide equipment forthe mines.
- Labour- 500 000 people work on the mines. With 8 or 10 dependants each, about 4 or 5 million people depend on their R75 billion wages in 2011.
What are the factors that favour and hinder mining in South Africa?
Factors favouring mining
- Power: The discovery of coal in Mpumalanga near the gold fields made cheap electricity available for the nearby mines.
- Labour: There are many unskillecl and semi-skilled workers in South Africa.
- Technology: South African mines are some of the most technologically advanced in the world.
- Raw materials: South Africa has a wide range of minerals and is the world’s leading producer of platinum, chrome and manganese.
- Infrastructure: An advanced network of roads, railways and harbours services the mines.
- Government: The government has always encouraged mining and is now assisting small-scale independent and previously disadvantaged miners.
- Markets: There are ready markets for our minerals both in South Africa and overseas.
Factors hindering mining
- Distances: Many of our minerals are found far from the coast.
- Dependence on foreign markets: 85% of our minerals are exported and thus we are dependent on foreign governments and companies for sales.
- Water: Water is a problem in a number of ways. Underground water is expensive to remove. The mines use a lot of water in the mining operation and in processing.
- Acid mine drainage: This is the flow of polluted water from old mining areas.
- Pollution: Apart from the pollution of water, mines often pollute the environment with dust and visually in the form of mine dumps.
- Climate: Some mining areas, such as those in the Northern Cape have very hot climates, making life uncomfortable.
- Fluctuating market prices: With recent low prices some mines have had to close.
1 What is the contribution of the secondary and tertiary sectors to the South African economy?
Since the early 1990s the country’s economic growth has been driven mainly by the tertiary sector. In this period the tertiary sector’s share of the GDP rose from 55% to its present 77% While that of manufacturing dropped from 28% to the present 14%.
2.1 Heavy industry
Heavy industry is the large-scale production of goods sold to other industrial customers rather than to the end consumer. Examples of heavy industry include chemicals, steel manufacture, oil refining.
2.2 Light industry
Light industry needs less capital than heavy industry. It is produced for the end user rather than for other industries. Examples of light industries include the manufacture of clothes and furniture.
2.3 Raw material oriented industries
Raw materials are the materials used to make a finished product. Where the raw materials are bulky or difficult to transport the raw material orientated industries must be located near the source of the raw material.
2.4 Market oriented industries
Market orientated industries produce goods that must be produced near the consumer.
2.5 Footloose industries
Footloose industries have a free choice of location.
2.6 Ubiquitous industries
Ubiquitous industries are not tied to specific sources of raw materials or specific markets. They are located everywhere.
2.7 Bridge industries or break of bulk point industries
Bridge industries, also called break of bulk point industries, transfer cargo to smaller units of transport. A bridge industry also occurs when imported raw material can be unloaded directly into the processing plant without further transport costs.
What are the factors influencing industrial development in South Africa
3.1 Energy
Factories need electricity and some factories have an agreement with ESKOM to buy electricity cheaply. Examples are the aluminium refineries in Richards Bay, each of which uses as much electricity as a large city.
3.2 Raw materials
South Africa has large quantities of primary industrial raw materials (like iron, coal, chrome, manganese, copper) while agriculture, forestry and fishing provide other important raw materials.
3.3 Labour supply
Labour supply is necessary for industry. Industries producing specialised goods tend to be located where skilled labour is concentrated.
3.4 Transport infrastructure
An efficient transport infrastructure is necessary for bringing in raw materials and distributing manufactured products. South Africa has a good network of roads, harbours and railways to support industry.
3.5 Political intervention
Political intervention in the form of government decisions has a major impact on factory location. The introduction of Industrial Development Zones (IDZs) and Spatial Development Initiatives (SD15) has encouraged industries to develop in certain areas.
3.6 Competition and trade
Compared with the large markets of Europe and Asia, South African markets are small. The competition from firms in these areas, especially China means items such shoes and clothing can be sold at a lower price than they cost to make in South Africa.
South Africa’s industrial regions
4.1 Manufacturing in Gauteng
The area extending from Pretoria to Sasolburg and from Brakpan to Randfontein, also known as the PWV, is Africa’s most important industrial region.
4.1.1 The factors influencing the location of industry
- Raw materials: Gold provided the initial stimulus for development of industry and industries arose to provide the mines with mining equipment. Other minerals and agricultural products all stimulate industrial growth.
- Labour supply: With jobs available in the manufacturing sector people from all over the world came to the area.
- Markets: Gauteng has the highest per capita GDP in South Africa and provides a large market for industrial products.
- Power: The huge power stations of Mpumalanga are close by.
- Transport: Gauteng is very well-served with road, rail and air links. The big disadvantage is that it has no port.
- Political intervention: The Gauteng Economic Development Agency (GEDA) has been developed by the Gauteng government to promote economic growth and development.
Factors limiting industrial expansion
4.1.3 Main industrial activities
Gauteng is the main centre of South Africa’s industrial activity. The region produces a wide range of products such as iron and steel, metal products, food, machinery, electrical appliances, vehicle parts and accessories and chemicals.
4.2 Manufacturing in the Durban—Pinetown area
This area is the second most important industrial area in South Africa.
4.2.1 The factors influencing the location of industry
Durban's harbour is the busiest in the country. The population of greater Durban is over 3,5 million which supplies labour and markets. With its high rainfall the area has many agricultural raw materials, especially sugar and timber. Apart from the port, the area is well-served by road, rail and air.
4.2.2 Main industrial activities
Durban has a wide range of industries. Because of its harbour location many are break of bulk. Food processing is one of the oldest industries. Sugar refining and timber processing are also important. The Toyota motor assembly plant employs 8 ooo people and produces over 200 ooo vehicles per year.
4.3 Manufacturing in the South-western Cape
The southern part of Western Cape is South Africa’s oldest industrial area and produces a wide variety of goods, especially food products and textiles.
4.3.1 The factors influencing the location of industry
Cape Town was the first European-style city in South Africa and industry grew to meet the demands of its inhabitants. These industries have remained there even though other factors suggest that for some of them a new location would be beneficial. This reluctance to move is due to industrial inertia. The region has over 3, 5 million inhabitants and their skill levels are among the highest in South Africa
4.3.2 Main industrial activities
- Fruit is processed into canned fruit, fruit juices and wines in Cape Town and the surrounding small towns.
- The largest manufacturing industry in the province is the clothing and textile industry. This is presently declining in importance, due to competition from cheaper Eastern producers, such as China and Vietnam.
- The cold waters of the Benguela current provide food for the abundance of fish in the sea around the Western Cape. The fish are canned and packed in Cape Town and in the many small towns along the Western Cape coast.
- High-tech industries are growing in importance and are taking the place of the declining textile and clothing industry.
- Iron and steel are important products. Saldanha Bay, 100 km north of Cape Town, is the terminus of the railway line that carries iron and manganese from Sishen in Northern Cape. A steel manufacturing plant has been built at Saldanha Bay.
4.4 Manufacturing in the Port Elizabeth-Uitenhage area
This is the smallest of South Africa’s main industrial regions, with 8% of South Africa’s industrial output. It is known for the production of motor vehicles and the associated industries.
4.4.1 The factors influencing the location of industry
The port location has been the main attraction for industries in this area. The new deep water port at Coega, 20 km north of Port Elizabeth, will encourage further development in the area. The area has many agricultural raw materials.
4.4.2 Factors limiting industrial expansion
The supply of water is a problem and additional water is obtained from the Orange River via the Orange
4.4.3 Main industrial activities
Textiles and leather goods: These are made using leather from the cattle and wool from the sheep in the hinterland.
Motor vehicles: General Motors and Ford started assembling motor cars at Port Elizabeth nearly 90 years ago. Volkswagen built an assembly plant at Uitenhage in 1947. The area was chosen for its centrally located port so the finished vehicles made from imported parts could be sent easily to the rest of the country. Most other industries in the area provide accessories such as tyres, batteries and windscreens.
Strategies for industrial development
1 Apartheid and post-apartheid industrial development strategies
1.1 Apartheid strategy — border industries
The policy of apartheid meant that South Africa was to be a ‘white’ republic in which black people did not feature as citizens. This ‘bantustan’ policy sought to place all black Africans in a ‘homeland’ according to their ethnic identity. Ten homelands were created (Figure 79).
Figure 79 The former ‘homelands’ in South Africa. Note the different provinces.
These homelands had very few job opportunities and the concept of border industries was introduced. Incentives were offered in order to encourage industrialists to invest in growth points which bordered the homelands. These incentives included tax concessions, labour concessions, transport subsidies and tariff protection. The aim of all these measures was clear: to halt, or even reverse the flow of black Africans to the ‘white’ areas.
1.2 Post-apartheid industrial development strategies
There have been a number of strategies aimed at economic, political and social development through post-apartheid industrial development. The aim is to develop less developed areas. The main industrial initiatives are the Spatial Development Initiatives (SDls) and Industrial Development Zones (IDZs).
1.2.1 Growth, Employment and Redistribution (GEAR)
GEAR was a large scale strategy aimed at creating a fast-growing economy and sufficient jobs.
1.2.2 Black Economic Empowerment (BEE)
In the years before democracy in 1994, the apartheid government excluded black people from meaningful participation in the economy. BEE was introduced to rectify the wrongs of the past while helping to bring the black majority into the economy.
1.2.3 Accelerated and Shared Growth in South Africa (Asgi-SA)
Asgi-SA was introduced to achieve economic growth and to halve poverty and unemployment by 2014.
2 What are Industrial Development Zones (lDZs)?
An Industrial Development Zone (or IDZ) is an industrial estate linked to an international sea or air port that encourages export oriented manufacturing industries. They aim to promote the manufacturing sector and to encourage beneficiation of local resources.
3 What are Spatial Development Initiatives (SDIs)?
A Spatial Development Initiative (or SDI) aims to promote growth in those parts of South Africa that are underdeveloped but have potential for growth. The most successful SDI has been the Maputo Corridor. This is a major trade corridor connecting Gauteng and Mpumalanga with Maputo in Mozambique. One hundred and thirty investment opportunities have been identified in the infrastructure, agriculture, mining, energy, chemicals, tourism and manufacturing sectors.
4 What are the issues associated with industrial centralisation and decentralisation
4.1 Centralisation
If an industry is successful in an area its success will attract other forms of economic development and create jobs, services and wealth leading to the centralisation of industry in a few areas.
The advantages of centralisation are that factories use the same physical infrastructure such as power, water and transport. Skilled labour, markets and financial services are all in the same area. This can lead to problems, as shown in Figure 80.
1 The concept and characteristics of informal sector employment
1.1 What is the concept of the informal sector?
The informal sector refers to that part of an economy that is not taxed and is out of official government records. Workers have no employment contracts and do not belong to trade unions.
1.2 What are the characteristics of the informal sector?
The characteristics of the informal sector are summarised in Figure 81.
2 What are the reasons for high informal sector employment in South Africa?
The number of people involved in the informal sector is estimated to be about 3 million out of a labour force of about 13 million and growing at about 8% per year. This is large in a country like South Africa with a well-established economy.
- Under apartheid black people were denied entry to much of the economy except as unskilled or semi-skilled labourers. Many were unable to obtain a decent education.
- With high unemployment more people have to obtain work in the informal sector in order to sur\nve. As unemployment increases so does the informal sector.
- Many of South Africa’s informal sector jobs are carried by non-South Africans, especially Zimbabweans, as they are often denied access to formal employment.
3 What are the challenges facing South Africa’s informal sector?
- Traders do not have access to proper trading facilities.
- Traders and their goods are exposed to the weather.
- Traders are frequently harassed by local authorities.
- Banks do not like to give loans to informal traders.
- The sector is unpredictable and the income unreliable.
- There is little time or incentive to improve their education or training.
- Many have HIV/Aids and as the illness gets worse work becomes increasingly difficult.