Grade 9 Geography Past Paper 2024 PDF

TERM 3 GRADE 9 GEOGRAPHY PLATINUM PAGE 54  Weathering Wearing away of rocks and soil due to water, wind, temperature and Animal factors.  Types of weathering Physical weathering Weathering due to frost and change in temperatures...

TERM 3 GRADE 9 GEOGRAPHY PLATINUM PAGE 54  Weathering Wearing away of rocks and soil due to water, wind, temperature and Animal factors.  Types of weathering Physical weathering Weathering due to frost and change in temperatures Chemical weathering Weathering due to chemical changes that weakens rock Biological weathering Weathering due to action of plant and animals  Types of physical weathering ▪Freeze and Thaw ▪Exfoliation Freeze and Thaw [figure 2] PAGE 57  Exfoliation Removal of the outer layer of rocks due to changes in temperatures. (expansion and contraction without water under extreme hot and cold temperatures)  Types of chemical weathering Carbonation Oxidation Hydrolysis  Carbonation Carbon dioxide in cold environments dissolved in water to from carbonic acid which then contacts rocks with calcium/magnesium to form carbonate (Mg/CaCO3) rocks (Limestone or dolomite) The Rocks then dissolve in water and gets washed away. Oxidation Rocks with iron(Fe) mixes with oxygen in water. Rust  Hydrolysis Hard rocks(granite) absorbs water and changes into clays then easily weathers  Biological weathering Plant growth, worms and moles burrow( digs and weakens) rock therefore exposes the rock to weathering.  Biological weathering Lichens-plants that grows on rocks release chemical acid that weakens the rock [PAGE 60]  Erosion Removal of weathered material (load) by water, wind or animals.  Deposition Depositing of weathered material(load) DATE: Exercise 1:Definitions Define the following Terms 1.1 Physical weathering 1.7 Deposition 1.2 Chemical weathering 1.8 Meander 1.3 Biological weathering 1.9 Weathering 1.4 Freeze and Thaw 1.10 Carbonation 1.5 Exfoliation 1.11Oxidation 1.6Lichens 1.12 Hydrolysis DATE: Exercise 2 2.1 What condition are required for exfoliation to happen 2.2 How can carbonation be a danger to be people? 2.3 Why is carbonation greater in cold areas? River system 19 Rivers 20  Source Where a river starts(origin) 21  Tributaries Smaller rivers/streams that joins a larger rivers. 22  Confluence Point where tributaries join 23 River Mouth River End 24  Interfluve High region in-between rivers and tributaries. 25 Load Material carried by the river/wind/animals from high point of potential energy (boulders) to an area of low potential energy.(finer material)  Types of Fluvial landforms Landforms formed Erosion and deposition by water flow Rapid /Cascades Waterfalls Meanders Oxbow lakes Braided streams Flood plains Natural levees 27 Rapid /Cascades Small Steps like falls created when water flows over uneven ground 28  Waterfalls Sudden fall of flowing water over a cliff (sudden edge of high a land) 29 Waterfall cliff 30 Gorge from the continues retreat of a waterfall Canyon from the continues retreat of a waterfall(s) Meanders bending of a river due to erosion and deposition. 33  Meander formation Rivers flows faster on some sections of the river forming the outside of the bend due to erosion. River cliff Figure 3.17/3.18 page 127 River flows slower on some areas and deposits sediments which form the inside of the bend Figure page 65] 34  Oxbow lakes Meander loop that has been cut off from the rest of the river 35 Formation of Oxbow lakes 36 Figure 5 page 65] DATE:[Exercise 3 ] 2.1 How is a Gorge formed? 2.2 Using diagrams and sketches illustrate the Formation of an Ox bow lake. 2.3 Name the feature that appears on the opening page 54 figure 1 Desert Erosion and Deposition Abrasion: The process of scraping material away. In an area with little vegetation wind abrasion is great. Desert Formations Wind erosion Mushroom rocks Yardang Wind deposits Barchans sand dunes Sief dunes Transvers dunes  Mushroom rocks Horizontal alternating soft and hard rocks after abrasion in the desert. Figure 20 page 74  Yardang Abrasion of vertical alternating soft and hard desert rocks Figure 20 page 74 Transvers dunes Barchans sand dunes Sief dunes DATE:[Exercise 5] 5.1 Give three erosional features of wind deposits in a desert 5.2 Why do you think wind erosion is common in areas with little vegetation? 5.3Name two types of Desert rock formations and how they are formed. 5.4How can you tell that the river in figure 2 page 55 in a dry area? Activity 2 page 79 (1 and3 only) Impact of human on soil Deforestation Agriculture Construction Desertification Mining  Soil erosion-Removal of soil from land Deforestation-Removal of natural vegetation Agriculture Cultivation –ploughing weakens soil and leads to erosion. Overgrazing -animals eating roots destabilizes the soil. Monoculture Vs crop rotation-farming one type of crop reduces a certain type of mineral such as nitrogen when farming maize. Construction- destabilizing the soil. Mining-removes vegetation,dust and chemicals damage soils  DATE:[Exercise 6] 6.1 Differentiate between Crop rotation Vs Monoculture. 6.2 How does mining activities impact soil erosion? 6.3 Study figure 5 page 61 How does 6 lead to carbonation? How does 2,5 and 7 impact soil ?  Braided streams A stream with shallow small channels disconnecting and re-joining. 54 Flood plains Level (flat area) on the side of the river due to sediment deposit after flooding 55  Natural levees Raised river bank(New river beds) formed by deposition after repeated flooding 56 figure 6 page 66  Delta Depositional formation when a river enters a sea/ocean or a large lake or a level inland area. River breaks into small channels (distributaries) 57  Types of Delta Arcuate delta Bird’s foot delta Estuarine delta (Estuary) Cuspate delta 58 Arcuate delta Curved Arc shaped distributaries forming new land in-between them. Botswana-Okavango inland delta. Niger delta –Nigeria 59 Bird’s foot delta Birds claws shaped distributaries 60 Estuarine delta (Estuary) Very shallow wide open river mouth. 61  Cuspate delta Concave triangular shaped with little or no distributaries 62  Headlands and Bays Hard rocks form headlands The softer rocks will forms bays Coast (ocean continent boundary) [Figure 8 page 67]  Erosion of Headlands Wave action can erode the base of the headland to form a Cave A cave erodes form an Arch An Arch erode to a stack and stacks form stumps [Figure 10 page 68]  Longshore drift The movement of high and low tides (waves action) parallel to the shore Rocks and sand get carried along forming a beach. Bar and lagoon Enclosed inland mixture of river and sea water joining the headlands forms a bar Salt marsh mixture of plant and mud.  Spit River sand that was initially deposited into the ocean and then spitted back into The river mouth or headland/bay DATE:[Exercise 4] 3.1Name and explain the formation of the feature on page 68 figure 11. 3.2 How are lagoons formed? 3.3 What is the difference between a lagoon and a salt marsh? 3.4 What are deltas ? 3.5 Name four types of deltas 3.6 Where is the location of the Niger delta and Okavango delta? 3.7What type of delta is the Niger delta and Okavango delta?  Glaciation The movement of ice/snow downhill due to gravity Glaciation features ice hollow  moraines Lateral moraines = rocks deposits on the sides of a valley due to glaciation Terminal moraines= rocks deposits at the end of a valley due to glaciation Eskers Meandering ridges in the middle of a channel due to glaciation.  Drumlins Round hills in the middle of the channel due to glaciation  DATE:[Exercise 4] 4.1Where do you expect to find the following features after glaciation? ▪ Lateral moraines ▪ Terminal moraines ▪ Eskers ▪ Horn