GEOGRAPHY CAMBRIDGE IGCSE: RIVERS PROCESSES AND FEATURES
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The document explains the processes and features of rivers throughout their journey from source to mouth. It covers key concepts in the water cycle, river morphology, and erosion processes, detailing features such as waterfalls, meanders, and oxbow lakes. The text emphasizes the dynamics of river flow and sediment transport across different river courses.
GEOGRAPHY CAMBRIDGE IGCSE: RIVERS PROCESSES AND FEATURES
- 2. THE LIFE OF A RIVERTHE LIFE OF A RIVER JOURNEY FROMJOURNEY FROM SOURCE TOSOURCE TO MOUTHMOUTH AN EXPLANATIONAN EXPLANATION OF PROCESSESOF PROCESSES AND FEATURES
- 3. What happens when water reaches the ground?What happens when water reaches the ground? CONDENSATIONCONDENSATION EVAPORATIONEVAPORATION PRECIPITATIONPRECIPITATION SEA LAND A SIMPLIFIED WATER CYCLEA SIMPLIFIED WATER CYCLE
- 4. Key WordsKey Words EVAPORATIONEVAPORATION CONDENSATIONCONDENSATION PRECIPITATIONPRECIPITATION RUN-OFFRUN-OFF PERCOLATIONPERCOLATION GROUND WATERGROUND WATER WATER STORESWATER STORES When water vapour changes to liquid (cooling)When water vapour changes to liquid (cooling) Water in any form that falls to earth e.g. rainWater in any form that falls to earth e.g. rain When the ground water moves through the landWhen the ground water moves through the land When water vapour changes to liquid (warming)When water vapour changes to liquid (warming) The water that is stored within the groundThe water that is stored within the ground Water that is stored e.g. ground,clouds,air etc.Water that is stored e.g. ground,clouds,air etc. Water that moves directly along the groundWater that moves directly along the ground without penetrating.without penetrating. Put the correct definition to the given word~one has been done for youPut the correct definition to the given word~one has been done for you
- 5. Detailed Water CycleDetailed Water Cycle
- 6. Completed Water CycleCompleted Water Cycle
- 7. River BasinsRiver Basins • Where a river begins is called the source.source. • A small river meeting a larger river is called a tributarytributary. • Where the two rivers join is called the confluenceconfluence • Where the river flows into the sea is called the mouthmouth. • The area drained by a river is called the drainage basin.drainage basin. • The ‘line’ that separates two drainage basins is called the watershed.watershed. Key WordsKey Words
- 8. THE LONG PROFILE OF A RIVERTHE LONG PROFILE OF A RIVER Upper CourseUpper Course Middle CourseMiddle Course Lower courseLower course SOURCESOURCE MOUTHMOUTH
- 9. Key WordsKey Words Hydraulic PowerHydraulic Power CorrasionCorrasion CorrosionCorrosion AttritionAttrition Water/debris isWater/debris is forced into cracksforced into cracks Rocks /stonesRocks /stones erode bed and sideserode bed and sides of river bank.of river bank. Rocks getRocks get smaller bysmaller by chemical actionchemical action Rocks get smaller when knocked togetherRocks get smaller when knocked together Rocks such as chalkRocks such as chalk and Limestoneand Limestone
- 10. The Upper Course of a RiverThe Upper Course of a River • Hydraulic powerHydraulic power This is the force of the water on the bed and banks of the river, powerful when in flood, the force of the water removes material from the bed and banks of the river. • CorrasionCorrasion When the river is particularly full, pebbles and boulders are carried along by the water. These rub against the bed and banks of the river and wear them away. The process is called abrasion. Processes of erosionProcesses of erosion
- 11. Processes of ErosionProcesses of Erosion CorrosionCorrosion River water sometimes causes some rock to slowly dissolve. (e.g. limestone dissolves in slightly acid water and is carried away in solution (as a liquid) as calcium hydrogen carbonate). AttritionAttrition The pebbles and small rocks being carried by the river - the load - collide and rub against each other, breaking up into smaller and smaller pieces. The rough edges become smooth, forming smaller rounded material. Eventually the particles are reduced to sand and silt-sized particles
- 12. Features of the upper course of a riverFeatures of the upper course of a river The main features of a Waterfall are: •A steep drop in the river ~ called a higha high head of waterhead of water •A plunge poolplunge pool at the base •Hard, resistant rock at the top~ the cap rockthe cap rock •Softer rock below that are undercut.undercut. Waterfalls and gorges are formed over aWaterfalls and gorges are formed over a long period of time they are characterisedlong period of time they are characterised by the following: -by the following: - •Bands of hard and soft rock being erodederoded at different rates. (softer rock the quickest) •The river moves back as the erosion takes place, this is known as recession.recession. •A gorge and waterfall have steep sidessteep sides
- 13. Hard cap rockHard cap rock (resistant)(resistant) Softer rock isSofter rock is undercut byundercut by backwash frombackwash from falling waterfalling water Softer less resistant rock isSofter less resistant rock is easily erodedeasily eroded by fast flowingby fast flowing water.water.
- 14. Deep plungeDeep plunge pool at base ofpool at base of waterfallwaterfall Undercutting hasUndercutting has taken place wheretaken place where softer rock is foundsofter rock is found
- 15. Waterfall overWaterfall over 150 metres high150 metres high Deep plunge pool atDeep plunge pool at base of waterfallbase of waterfall
- 16. The middle course of a riverThe middle course of a river Key wordsKey words TractionTraction -large boulders-large boulders roll along theroll along the river bedriver bed SaltationSaltation -smaller pebbles are bounced along the river bed, picked up-smaller pebbles are bounced along the river bed, picked up and then dropped as the flow of the river changesand then dropped as the flow of the river changes
- 17. Key words continuedKey words continued SuspensionSuspension -the finer sand and silt-sized particles are carried along in the-the finer sand and silt-sized particles are carried along in the flow, giving the river a brown appearance.flow, giving the river a brown appearance. SolutionSolution -minerals, such as limestone and chalk, are dissolved in the-minerals, such as limestone and chalk, are dissolved in the water and carried along in the flow, it often cannot be seen.water and carried along in the flow, it often cannot be seen.
- 18. The middle course of a riverThe middle course of a river •MeandersMeanders Erosion onErosion on outside bendoutside bend DepositionDeposition on insideon inside bendbend
- 19. Feature of the middle courseFeature of the middle course A Meander (cross-section)A Meander (cross-section) Label the diagram with the following words and statements:-Label the diagram with the following words and statements:- Outside bend, inside bend, erosion, deposition, river cliff,Outside bend, inside bend, erosion, deposition, river cliff, deepest water and fastest current.deepest water and fastest current. BBAA BBAA
- 20. Feature of the middle courseFeature of the middle course A Meander (cross-section)A Meander (cross-section) Outside bend, inside bend, erosion, deposition, river cliff,Outside bend, inside bend, erosion, deposition, river cliff, deepest water and fastest current.deepest water and fastest current. BBAA BBAA
- 21. The lower course of a riverThe lower course of a river •Ox-bow lakesOx-bow lakes •Flood plainsFlood plains
- 22. Oxbow or ‘cut-off ’ lake New course of the river Steep undercut bankRiver straightens at this point and cuts off the ox-bow Part of the flood plain