GEOMORPHOLOGY QUESTIONS AND ANSWERS GRADE 12

GEOMORPHOLOGY QUESTIONS AND ANSWERS GRADE 12, Geomorphology is the study of landforms and landform evolution. The topic traditionally has been studied both qualitatively, which is the description of landforms, and quantitatively, which is process-based and describes forces acting on Earth’s surface to produce landforms and landform change.

Activity 2.1

1. List three important things that should be present for water to infiltrate into the soil. (3 × 2 = 6)
2. Describe how groundwater supplies are replenished (filled up). (1 × 2 = 2)
3. Why is it important to manage (look after) groundwater? (1 × 2 = 2)
   [10]

In the exam, you may be given a diagram and asked to identify which aspect or factor has affected the runoff or infiltration.

Activity 2.2
Refer to drainage basins A and B in Figure 2.2.2C and the flow hydrograph showing line graphs D and E after a period of rainfall, to answer the following questions.

1. The rivers in drainage basin A flow all year round. What type of river would this be classified as? (1 × 2 = 2)
2. Graph D in the flow hydrograph shows the runoff of drainage basin A after a period of rain.
   1. Define the term ‘lag time’. (1 × 2 = 2)
   2. How would the lag time change if massive deforestation were to occur in drainage basin A where D was recorded? (1 × 2 = 2)
   3. Justify your answer in question b). (2 × 2 = 4)
   4. Name another factor which could occur and have the same impact on the lag time as mentioned in question b). (1 × 2 = 2)
3. 1. State the drainage density of drainage basin B. (1 × 2 = 2)
   2. Describe THREE possible causes for the drainage density found in drainage basin B. (3 × 2 = 6)
      [20]

Complete activity 2.2 to practise the concepts you have learnt so far in this chapter.

Activity 2.3
Identify and briefly describe the drainage patterns in Figure 2.2.3G below.
(3 × 4 = 12)
[12]

Activity 2.4

1. Draw a longitudinal profile of a river (from source to mouth) and show the upper, middle and lower courses. (1 × 4 = 4)
2. List two features of the upper course of a river. (2 × 2 = 4)
3. Describe a river in its lower course. (2 × 2 = 4)
4. Describe one difference between the river channel in the upper course and the lower course. (2 × 2 = 4)
   [16]

Activity 2.5
Figure 2.2.5K (right) shows a plan view of an area before river capture has occurred. Redraw the rivers after river capture has occurred.
On the diagram you have drawn, label the resultant features of river capture.

[6]

South Africa is not a water rich country.

Activity 2.6
Use the topographical map of Nelspruit 2530BD at the back of this study guide to answer the following questions.

1. The contour interval of this topographical map is…
   1. 1000 metres
   2. 50 000 metres
   3. 25 metres
   4. 20 metres
2. The Crocodile River is a/an…
   1. Periodic river
   2. Exotic river
   3. Permanent river
   4. Seasonal river
      (2 × 2 = 4) [4]