Geography
Topographic Maps
• Definition: a map showing the relief of the land (hills and rivers) the eviction (forests,
cropland & parks) and many of the man made features (built up areas, roads, railways)
• Most countries have a medium scale map
• South Africa’s is 1:50 000
• 1cm on the map = 50 000cm in reality
• Country is too big so map is divided into 1913 maps each covering smaller areas
• These maps use symbols as well as colour coding to show natural & man-made features
• Natural features on topographic maps include:
o Relief features (Brown)
▪ Shape of land
▪ Hills
▪ Valleys
▪ Cliffs
o Drainage (Blue)
▪ Rivers
▪ Lakes
o Vegetation (Green)
▪ Forests
▪ Plantations
▪ Orchards
▪ Croplands
• Constructed features include: (Black)
o Roads
o Towns
o Buildings
o Farmland
o Railways
o Power lines
o Recreation grounds
• Other features include names of places, river, farms & boundaries (black)
• Different types of symbols on a map:
o Point (trig beacon)
o Line (road)
o Area (vlei)
,Contour Lines
• ASL = Above sea level (meters)
• Contour Line: a line drawn on a map joining places of the same height above sea level
• Relief: the shape of the Earth’s surface; the unevenness of the land surface including heights
and slopes
• Ridge: a long narrow steep-sided hilltop or mountain range
• Contour lines are an accurate way of showing all relief on maps as they show the size, shape
& steepness of all landscape features
• The numbers are added to show contour line’s height above sea level
• They join points the same height above sea level
• Contour lines with short, brown lines on one side indicates a depression on a map
• They point downslope
• Contour interval is the difference in altitude between contour lines – in SA usually 20m
interval
• Every 100m lines is bold
, • Trigonometrical beacons are built by land surveyors
• Measure significant point on the landscape (hilltops)
• An instrument called a theodolite is attached to the top of the pole
• Trigonometry is used to figure out height of beacon
• Definition: a small, white pillar holding a metal pole that has a vane on top are from 4 pieces
of metal at right angles
Steep and general slopes
• Cliff has a very steep slope
• Low hills usually have gentle slopes
• Anther word for slope is gradient
• Gradient can be measured and can be used to compare how height you climbed vs how far
you went
River valleys and spurs
• Rivers flow from highland to lake
• Each river is in a valley (river valley)
• The ridges of land separating the valley are the spurs
• Land slopes up in 3 directions for a valley
• Use V-Rule to find a valley or spur
• The O-Rule states that:
o Closed contour loops represent a hill if the land inside is higher
o If the higher land if on the outside, it is a depression
o When the lines are long and narrow, it is a ridge
, Different types of slopes
Area
Bearing
One way of describing laces on a map. It is a measurement of one place to another. Often direction
included in the description. A protractor is used to measure the angle from one place to another.
Bearing is always measured clockwise starting at north which is both 0 and 360.
Topographic Maps
• Definition: a map showing the relief of the land (hills and rivers) the eviction (forests,
cropland & parks) and many of the man made features (built up areas, roads, railways)
• Most countries have a medium scale map
• South Africa’s is 1:50 000
• 1cm on the map = 50 000cm in reality
• Country is too big so map is divided into 1913 maps each covering smaller areas
• These maps use symbols as well as colour coding to show natural & man-made features
• Natural features on topographic maps include:
o Relief features (Brown)
▪ Shape of land
▪ Hills
▪ Valleys
▪ Cliffs
o Drainage (Blue)
▪ Rivers
▪ Lakes
o Vegetation (Green)
▪ Forests
▪ Plantations
▪ Orchards
▪ Croplands
• Constructed features include: (Black)
o Roads
o Towns
o Buildings
o Farmland
o Railways
o Power lines
o Recreation grounds
• Other features include names of places, river, farms & boundaries (black)
• Different types of symbols on a map:
o Point (trig beacon)
o Line (road)
o Area (vlei)
,Contour Lines
• ASL = Above sea level (meters)
• Contour Line: a line drawn on a map joining places of the same height above sea level
• Relief: the shape of the Earth’s surface; the unevenness of the land surface including heights
and slopes
• Ridge: a long narrow steep-sided hilltop or mountain range
• Contour lines are an accurate way of showing all relief on maps as they show the size, shape
& steepness of all landscape features
• The numbers are added to show contour line’s height above sea level
• They join points the same height above sea level
• Contour lines with short, brown lines on one side indicates a depression on a map
• They point downslope
• Contour interval is the difference in altitude between contour lines – in SA usually 20m
interval
• Every 100m lines is bold
, • Trigonometrical beacons are built by land surveyors
• Measure significant point on the landscape (hilltops)
• An instrument called a theodolite is attached to the top of the pole
• Trigonometry is used to figure out height of beacon
• Definition: a small, white pillar holding a metal pole that has a vane on top are from 4 pieces
of metal at right angles
Steep and general slopes
• Cliff has a very steep slope
• Low hills usually have gentle slopes
• Anther word for slope is gradient
• Gradient can be measured and can be used to compare how height you climbed vs how far
you went
River valleys and spurs
• Rivers flow from highland to lake
• Each river is in a valley (river valley)
• The ridges of land separating the valley are the spurs
• Land slopes up in 3 directions for a valley
• Use V-Rule to find a valley or spur
• The O-Rule states that:
o Closed contour loops represent a hill if the land inside is higher
o If the higher land if on the outside, it is a depression
o When the lines are long and narrow, it is a ridge
, Different types of slopes
Area
Bearing
One way of describing laces on a map. It is a measurement of one place to another. Often direction
included in the description. A protractor is used to measure the angle from one place to another.
Bearing is always measured clockwise starting at north which is both 0 and 360.
