4.3 Calculating area oo a map  (Page 2/3)

ACTIVITY 4: [LO 1.3]

Study the accompanying extract from the 1 : 50 000 topographic map of South Africa, sheet 2926 AA Bloemfontein, and orthophoto 2926 AA 9 Spitskop and answer the following questions:

1. Identify the features of the landscape that occur at the following coordinates:

a) 29º05'40" S, 26º09'20" E.

b) 29º06' S, 26º10'35" E.

2. Indicate the position of the 2926 AA Bloemfontein map sheet by means of a simple sketch:

Indicate which map sheet lies directly to the:

a) North

b) West

c) South ______ of 2926 AA.

1. Indicate the position of the 2926 AA 9 Spitskop orthophoto by means of a simple sketch:

1. How does the scale of a topographic map and of an orthophoto differ?

Which scale is larger?

• What can you identify with regard to recreation facilities available to the inhabitants of Bloemfontein by careful investigation of the topographic map and the orthophoto?
• Why do we observe a considerable number of wind pumps in the environment?
• Study the precipitation figures for Bloemfontein that are provided below:

1. Draw a column graph to represent the rainfall data. Use a vertical scale of 1 cm to 10 mm.

1. Which season has the highest rainfall?

1. Which month receives the highest rainfall?

ACTIVITY 5: [LO 1.4]

1. A cellular telephone service provider wants to erect a communications tower for the cellular phone service. It has to be situated on the highest point in the area. Provide the height in metres of the highest point indicated on the map. Also provide the coordinates for the specific point.

2. Provide a reason why the observatory (Observatory Theatre) was built on Naval Hill (29°05’45” S, 26°14’20” E) and not in a more central part of the city.

3. Calculate magnetic north from trigonometry beacon Δ 50 (29°03’45” S, 26°10’50” E). Show all calculations.

4. How long will it take a traveller to go from the one N1 intersection (29°07’45” S, 26°10’ E) to the other N1 intersection (29°05’30” S, 26°10’20” E) if an average speed of 120 km/h is maintained?

5. Calculate the area of the terminal building of the railway line (square black building) at 29°06’50” S, 26°14’50” E. Show all calculations.

6. What is true north from Δ 174 (29°05’25” S, 26°11’30” E) to the peak of Spitskop (29°05’40” S, 26°9’20” E.)

ACTIVITY 6: [LO 1.2]

Use the orthophoto only and answer the following questions:

1. Is this orthophoto a vertical or an oblique aerial photograph?
2. Which part of Bloemfontein is shown on the orthophoto? Indicate the exact position with faint pencil lines on the 1 : 50 000 or topograpic map sheet.
3. What is the real distance in km from the N1 road junction near Tempe (at Dam van Trane) to the road junction near Rayton in the northeast?
4. In which direction do you travel from the Tempe road junction to the road junction near Rayton?
5. Which kind of activity will take place at Tempe? Look at the long buildings arranged in rows that are there, in particular. What is the direction in which the shadows of these buildings fall?

1. At what time of day, therefore, was the photograph taken?