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: Brought to you by Page 1
Katabatic Winds: ASPECT OF SLOPE: OCEAN CURRENTS: Brought to you by Page 2
LAND AND SEA BREEZES: Land Breeze: Sea Breeze: HEAT ISLANDS: Brought to you by Page 3
FLUVIAL PROCESSES AND LANDFORMS AND MAPWORK PROFILES Longitudinal profile graded and ungraded. Brought to you by Page 4
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 Brought to you by Page 5
DRAINAGE DENSITY: Diagrams showing density: Brought to you by Page 6
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 Brought to you by Page 7
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 Brought to you by Page 8
DRAINAGE PATTERNS: Brought to you by Page 9
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CONTOUR LINES AND ASSOCIATED FEATURES/LANDFORMS GENTLE SLOPE STEEP SLOPE UNIFORM SLOPE TERRACED SLOPE Brought to you by Page 11
CONCAVE SLOPE CONVEX SLOPE Contour Sketch and Profiles: Brought to you by Page 12
UNDULATING LANDSCAPE BUTTE Brought to you by Page 13
MESA / TAFELBERG VALLEY / SPUR Brought to you by Page 14
POORT / GAP Brought to you by Page 15
ESCARPMENT: SCARP AND DIP SLOPE: Brought to you by Page 16
CLIFF: Waterfall: Brought to you by Page 17
GORGE: WATERSHED: Brought to you by Page 18
X-AMPLE QUESTIONS: Question 1: Map of Rustenburg West: Z 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: G F 2.1 Explain the concept aspect of slope. Brought to you by Page 19
Question 3: J K 3.1 Explain the concept heat island. Question 4: Map of Humansdorp: M 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. Brought to you by Page 20
Question 5: Refer to the map extracts. Map of Rustenburg West: P 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. Brought to you by Page 21
Question 7: Map of Humansdorp: Q 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 20cm 10cm Scale 1cm: 50000cm Brought to you by Page 22
Question 9: Selons River River 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. Brought to you by Page 23
Question 10: River 10.1 State the direction of the river running through Doornlaagte and give a reason for your answer. Question 11: River Pattern 11.1 Identify the Drainage pattern in Blocks C7/8. Give a reason for your answer Brought to you by Page 24
Question 12: 12.1 Identify the feature marked E on the topographical map. P Q 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: Brought to you by Page 25
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) Brought to you by Page 26
X-ERCISE QUESTIONS Question 1: Map of Rustenburg West: G F Using aspect of slope explain why there is farming taking place at G and not at F Question 2: J K 2.1 Which area J or K will experience Higher temperatures? Give four reasons for your answer. Brought to you by Page 27
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) Brought to you by Page 28