<< Chapter < Page Chapter >> Page >

Social sciences


Grade 8


Module 15

Conventional signs used on 1:50000 maps

Conventional signs used on 1:50 000 maps

These signs form part of the “language” of topographic maps. They are provided in the key / reference below the map and are used the world over. You should get to know and understand them thoroughly.

Map symbols for cultural phenomena (phenomena created by people)

The signs used on maps are selected to be immediately recognisable for what they represent. Cultural phenomena that are shown are buildings, towns, power lines (in black) dams, canals (in blue) trees, plantations and fields (in green). These symbols are exaggerated on the map, because they would be too small to be represented if their actual sizes were represented.

Map symbols for natural phenomena

The most important natural phenomena are mountains, hills, valleys and plains. These phenomena, however, have to be deduced from contour lines and are not represented by specific symbols. We’ll be studying contour lines shortly.

Another important natural phenomenon shown on topographic maps is the drainage of any particular area. This is observed by examining the rivers and their tributaries, which are indicated in blue on a topographic map.

On topographic maps, perennial rivers are indicated by means of continuous blue lines, while the (seasonal) rivers of areas with low or seasonal rains are indicated with dotted lines).

The direction of the flow of a river also provides important information about the higher and lower parts of an area:

Water ALWAYS flows from high to lower places.

Tributaries flow into the main stream in the direction of the flow.


Observe the way in which dam walls are constructed across a river bed. The dam wall is always downstream.


Height prediction on a topographical map

Height can be indicated on a map in several ways.

The trigonometric beacon is shown by means of a triangle with the beacon’s number to the right of the triangle, as well as its exact height above sea level, in metres, below the triangle. On a map, these beacons are usually shown to be on the highest parts.


SPOT HEIGHTS on a map are shown by means of black dots and the height value is printed alongside it.

● 1419


The vertical difference in height between two high points is obtained by subtracting the lower measurement from the higher one,e.g.: A = 800 m; B = 200 m; Difference in height = 600 m.

Contour lines are unbroken brown lines marked in number values.

Contour lines connect all places that have the same height above sea level. The figure printed on the line indicates the actual height in metres.

The difference in height between two consecutive contour lines is known as the contour interval or vertical interval and is always 20 m. Each 100 m is indicated with a thicker contour line.

The further apart the contour lines are, the more level (flat) the landscape.

The closer to one another the contour lines are, the steeper and more mountainous the landscape.

Where there are perpendicular cliffs, contour lines touch. Remember, however, that contour lines never cross one another.

By examining the contours, you will be able to determine the direction in which a river is flowing and to identify certain forms of the landscape.


[LO 1.4]

1. Explain what is represented by the following map symbols:






2. Carefully study the area between the N1 and the R81 (SE corner of the map). Name at least six map symbols that occur in this area.

3. Are there any indications that the railway is electrified?

4. What type of communication lines join Beaufort West with the outside world?

5. What map symbols will you find at the following coordinates?

a) 32º17’06”S ; 22 37’15”E

b) 32º19’11”S ; 22 34’04”E

c) 32º20’49”S ; 22 34’09”E

d) 32º19’26”S ; 22 37’28”E

6. What is the average height above sea level in the vicinity of the rifle range(32º19’06”S ; 22º35’37”E)?

7. What is the height of the highest trig. beacon on the topographic map?

8. What is the contour interval on this map?

9. Determine the vertical difference in length between Lammertjiesleegte (32º20’52”S; 22º33’37”E) and trig. beacon 148.

10. Is there any relation between the route of the railway and the relief of the area?

11. What is the name of the perennial river in this area?

12. In which direction does this river in no. 11 flow?

13. Do you think there is a flood danger in this area? Explain.

14. What indications are there on this map that stock farming occurs in this area?

15. What do you think is the purpose of the furrows indicated on the map?

16. What can you derive from the rainfall in this area?


Learning Outcomes(LOs)
LO 1
Geographical EnquiryThe learner will be able to use enquiry skills to investigate geographical and environmental concepts and processes.
Assessment Standards(ASs)
We know this when the learner:
  • identifies and selects a variety of
geographical and environmental sourcesthat are relevant to the research;
  • interprets information from maps and
atlases, as well as graphic and statisticalsources;
  • calculates distance from maps and
compares it to real distance;
  • identifies physical features and features
created by people and aerial photographsand maps.



  1. Graves.
  1. Excavations.
  2. Provincial border.
  3. Power lines.
  4. Trigonometrical beacon
  1. Faint roads, rivers, buildings, railway lines, power lines, dams, windmill, forested area, cultivated lands, trigonometrical beacons, spot height, rows of trees.
  2. None.
  3. Roads, railway line.
  1. Railway line.
  1. Faint footpaths.
  1. Cultivated lands.

Built-up area. (Mgquba).

  • ±550 – 600 m.
  • ρ 318 (32°45'50"S, 26°52'0"E) is 653,6 m high.
  • 20 metres.
  • Hillcrest = 540 m.

ρ 84 = 624,2.

624,2 – 540 = 84,2 metres.

  • In general the railway lines follow the contour lines more than roads do.
  • Tyume.
  • Comes from the north and leaves the map in the south-west.
  • Yes, when it rains a lot the areas where the 2 main streams converge, can be flooded.
  • Irrigation dams and cultivated lands close to rivers.
  • Trees and bushes.
  • Moderate to reasonably high rainfall.

Questions & Answers

find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
okay, so you have 6 raised to the power of 2. what is that part of your answer
I don't understand what the A with approx sign and the boxed x mean
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
I'm not sure why it wrote it the other way
I got X =-6
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
oops. ignore that.
so you not have an equal sign anywhere in the original equation?
is it a question of log
Commplementary angles
Idrissa Reply
im all ears I need to learn
right! what he said ⤴⤴⤴
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Got questions? Join the online conversation and get instant answers!
QuizOver.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Geography grade 8. OpenStax CNX. Sep 11, 2009 Download for free at http://cnx.org/content/col11036/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Geography grade 8' conversation and receive update notifications?