SESSION 9: CLIMATE AND WEATHER, FLUVIAL PROCESSES...

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SESSION 9: CLIMATE AND WEATHER, FLUVIAL PROCESSES AND MAPWORK

KEY CONCEPTS:

In this session we will:

Integrate theory and mapwork.

Look specifically at how climate and weather and fluvial processes can be

tested in mapwork.

Learner Notes:

Climate and weather and fluvial processes can be tested in mapwork. When studying theory learners need to incorporate the relevant map work sections at the

same time and not study them separately. A proper knowledge of theory is needed when answering these sections in mapwork. This is the reason why both papers are written on one day.

X-PLANATION: CLIMATE AND WEATHER AND MAPWORK

Learner Notes:

The climate and weather sections indicated below are generally tested in mapwork.

VALLEY CLIMATES:

Mountain and Valley Winds

Anabatic Winds:

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Katabatic Winds:

ASPECT OF SLOPE:

OCEAN CURRENTS:

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LAND AND SEA BREEZES:

Land Breeze:

Sea Breeze:

HEAT ISLANDS:

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FLUVIAL PROCESSES AND LANDFORMS AND MAPWORK

PROFILES

Longitudinal profile – graded and ungraded.

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Cross Profile:

- Matching cross profiles with the different stages of a river - Different temporary base levels

- Rejuvenation

STREAM PATTERNS:

- Meander

- Ox Bow Lake - Braided Streams

- Delta

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DRAINAGE DENSITY:

Diagrams showing density:

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Calculation of Drainage Density of a Drainage Basin:

It is the total length of streams per unit area of a drainage basin

Formula:

Total length of the streams in the basin [km] Total area of the drainage basin [km²]

PERENNIAL AND NON PERENNIAL STREAMS

Perennial streams flow throughout the year. When looking at the map you won’t find many dams and more vegetation. It is represented by solid blue lines

Non perennial streams flow during the rainy season. They are generally associated

with seasonal rainfall. You will see more dams, reservoirs and windmills. It is represented by broken blue lines

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DIRECTION OF RIVER FLOW

When working out the direction of river flow we look at the direction in which the gradient is decreasing. We consider the following:

1. Contour lines 2. Spot heights

3. Trigonometrical beacons 4. The direction in which the river is entering a dam or leaving the dam wall 5. The V shape created by the tributaries and main stream point to the direction

to which the river is flowing

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DRAINAGE PATTERNS:

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CONTOUR LINES AND ASSOCIATED FEATURES/LANDFORMS

GENTLE SLOPE STEEP SLOPE

UNIFORM SLOPE TERRACED SLOPE

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CONCAVE SLOPE CONVEX SLOPE

Contour Sketch and Profiles:

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UNDULATING LANDSCAPE

BUTTE

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MESA / TAFELBERG

VALLEY / SPUR

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POORT / GAP

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ESCARPMENT:

SCARP AND DIP SLOPE:

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CLIFF:

Waterfall:

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GORGE:

WATERSHED:

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X-AMPLE QUESTIONS: Question 1:

Map of Rustenburg West:

1.1 Is area Z a valley or a spur? Give a reason for your answer. 1.2 With the aid of a diagram state and explain the type of wind that this area will

experience at night.

1.3 With the aid of a diagram state and explain the type of wind that this area will experience during the day.

Question 2:

Map of Rustenburg West:

2.1 Explain the concept aspect of slope.

Z

G

F

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Question 3:

3.1 Explain the concept heat island. Question 4:

Map of Humansdorp:

4.1 Name the ocean current found in this area. 4.2 State the effect that this ocean current will have on the temperature and

precipitation of area M.

4.3 State the type of breezes area M will experience during the day and night.

K

J

M

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Question 5:

Refer to the map extracts.

Map of Rustenburg West:

5.1 At what stage of a river is the river P in D2?

5.2 Draw and describe the cross profile that would be associated with this stage. 5.3 State the stream patterns/temporary base levels that are associated with this

stage. Question 6:

Map of Rustenburg West:

6.1. Explain the concept rejuvenation of a river.

6.2. Is rejuvenation occurring in J10? Give evidence from the map. 6.3. Is the longitudinal profile of the river graded or ungraded? Give a reason for

your answer.

P

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Question 7:

Map of Humansdorp:

7.1 At what stage is the river? 7.2 Draw and describe the cross profile that would be associated with this stage. 7,3 Name and explain stream pattern Q in I4

7.4 State two other stream patterns that are associated with this stage. Question 8:

Calculate the drainage density, using the following information

Total length of the streams in the basin = 200km

Area of basin

Scale 1cm: 50000cm

Q

10cm

20cm

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Question 9:

9.1 Differentiate between the Selons River (K1) and the river in Block K4 9.2. State the water table/s that the Selons River and the river in Block K4 intersect.

River

Selons River

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Question 10:

10.1 State the direction of the river running through Doornlaagte and give a reason for your answer.

Question 11:

11.1 Identify the Drainage pattern in Blocks C7/8. Give a reason for your answer

River

River

Pattern

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Question 12:

12.1 Identify the feature marked E on the topographical map.

12.2. Is Block D3 associated with inclined or horizontal rock strata 12.3 Identify and describe P and Q (D3)

12.4 Locate the Rustenburg Hiking Trail in blocks J 7/8:

P

Q

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12.4.1 You are a novice hiker, who is very unfit. You are given a choice between

doing hiking trail C or D starting at F in J8. Which hiking trail would you

choose? Give ONE reason for your answer. 12.4.2 Identify the landform at F from where you will start your hike.

12.5 Draw a rough cross-section from .1533 to D. Show all slope elements

(6)

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X-ERCISE QUESTIONS Question 1:

Map of Rustenburg West:

Using aspect of slope explain why there is farming taking place at G and not at F Question 2:

2.1 Which area J or K will experience Higher temperatures? Give four reasons for your answer.

G

F

K

J

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SOLUTIONS TO X-ERCISE QUESTIONS Question 1:

G is on the north facing slope and in the southern hemisphere the north facing slope

receives more sunlight. Question 2:

K

K is an urban area It has more artificial surfaces, such as concrete, steel and tar.

It has artificial sources of heat e.g. industrial heating It has far more polluted air which trap the heat. It has far less vegetation.

(Accept other)