2.6 Rainfall  (Page 2/2)

Graphic representation of rainfall for Pretoria

1. Rain throughout the year

The area from the Breede River to Port Elizabeth gets the same amount of rain throughout the year. This varies between 500 and 1 000 mm per year. The region runs further up the coast up to the KwaZulu-Natal region, but here most of the rain falls in summer, although it rains in winter too.

The moisture-laden winds from the warm Mozambique and Agulhas currents are blocked by the escarpment and forced upwards. Condensation occurs and clouds on the seaward side of the escarpment cause the so-called relief rain.

Very thick natural forests occur in the southeast (Knysna). Indeciduous broad-leaved trees like yellowwood, stinkwood and blackwood trees are found here. Creepers like wild vines and many ferns and moss grow here in the dense shade of the gigantic trees. In the northeast the forests change to subtropical, with palm trees and mixed grasslands.

Activity 2:

To record the rainfall figures of mossel bay graphically by means of a bar graph

[lo 1.4; 1.7]

Record the rainfall information of Mossel Bay graphically in a bar graph below.

Graphic representation of rainfall for Mossel Bay

1. The dry regions

The major part of our country is dry. Convection rain in the form of isolated thunderstorms does bring rain. Because it is so dry, there is little vegetation, and erosion in these areas is therefore a big problem.

In the half-dry regions like the Karoo the vegetation consists of low, grey karoo shrubs like guarri and rhenoster bush and hardy grasses. In the drier areas along the west coast sparsely distributed succulents occur. These succulents have thick, fleshy leaves to store water. Some of them can survive for years without water.

Activity 3:

To complete the following table so that you may have a summary of the most important facts you have learnt until now

[lo 1.1; 1.3]

Answer the questions that follow:

Use the rainfall map on page 1 and your atlas to say which of the following towns/cities receive the most rain:

Durban or Bloemfontein

Port Nolloth or Port Elizabeth

Cape Town or De Aar

Mossel Bay or Pretoria

Read the following statement:

• The average rainfall per year for the following places will give you an idea of this situation. Find the places in your atlas.

Durban 1 065 mm per year

Ficksburg: 680 mm per year

Kimberley: 402 mm per year

Pofadder: 142 mm per year

Port Nolloth: 50 mm per year

What can you deduce from this data?

The graphs below show the annual rainfall for two places in South Africa.

Bar Graph 1

Bar Graph 2

- In what season does the most rain fall at each of the two places as depicted in the graphs?

Graph 1

Graph 2

- Would either of these places be suitable for successful maize farming? Maize requires summer rainfall of more than 400 mm per year.

- Do the graphs show any month with a rainfall of less than 30 mm?

Assessment

LO 1

GEOGRAPHICAL ENQUIRY

The learner will be able to use enquiry skills to investigate geographical and environmental concepts and processes.

We know this when the learner:

1.1 with guidance, selects and uses sources of useful geographical information (including graphs, maps and fieldwork outside the classroom) [finds sources];

• distinguishes between facts and opinions [works with sources];
• categorises information [works with sources];
• draws sketch maps and/or plans from field observation and measurements [works with sources];

1.7 demonstrates knowledge and under-standing of the issue through projects, discussion, debate and charts [communicates the answer].

Memoradum

ACTIVITY 3

• Durban
• Port Elizabeth
• Cape Town
• Mossel Bay

• Drier towards the west

• S
• W
• Yes