Leaving Certificate Geography

  • Home
  • Physical Geography
    • Skills (Maps, Photos, Graphs) >
      • Ordnance Survey Map skills
      • Aerial photographs
      • Graph skills
    • Horizons Second Edition >
      • Chapter 1 Plate Tectonics
      • Chapter 2 Folding and Faulting
      • Chapter 3 Earthquakes
      • Chapter 4 Volcanoes
      • Chapter 5 The rock cycle
      • Chapter 6 Weathering
      • Chapter 7 The Karst Landscape
      • Chapter 8 Mass Movement
      • Chapter 9 Rivers
      • Chapter 10 Coastal Studies
    • Planet and People physical chapters >
      • Plate tectonics >
        • Plate Tectonics 2
        • Plate Tectonics 3
      • Rock Formation and Cycle >
        • Rocks
        • Rock types and their formation
        • Rock Cycle
        • Rock Cycle 2
        • The Rock Cycle 3
        • Rock Landscapes: Limestone
        • Intrusive and Extrusive volcanic landforms
        • Human interaction with the rock cycle
        • Tara Mines case study
      • Folding and Faulting
      • Weathering and Erosion
      • River processes and features
      • Glaciation
      • Coastal Studies >
        • Coastal Studies Ms. Carr
  • Regional Geography
    • Horizons Regional Chapters >
      • Chapter 22 Concept of a region
      • Chapter 23 The Western Region
      • Chapter 24 The Greater Dublin Area
      • Chapter 25 The Paris Basin
      • Mezzogiorno: Peripheral European region
      • Subcontinental India
    • Planet and People Regional Chapters >
      • Regional Geography Outline
      • Definition of Regions
      • Ireland: The Greater Dublin Region - Core
      • West of Ireland - Ms. Carr
      • The West of Ireland : Peripheral Region
      • Core region: Paris Basin
      • European Regions (Core Periphery) >
        • Paris Basin: Ms. Carr
        • Mezzogiorno - peripheral region
        • Mezzogiorno: European Peripheral Region
      • Subcontinental Region: India >
        • Introduction
        • India: Powerpoint
        • India: Secondary Activities
        • India: Tertiary Activities
        • India: Ms. Carr
      • EU enlargement
  • Elective: Human Environment
    • Folens: Human Elective >
      • Chapter One: Populations
      • Chapter 2 Human development and overpopulation
      • Chapter 3 The dynamics of settlement
      • Chapter 4 Migration
      • Chapter 5 Urban problems
      • Chapter 6 Urban settlement and planning issues
    • Planet and People: Human Elective >
      • Chapter 1: Population Studies >
        • Population test
      • Chapter 2 Overpopulation in Sudan >
        • Overpopulation question
        • Overpopulation and Resources
      • Chapter 3: Migration >
        • Migration Test
        • Student presentations
        • Student Presentations 2
      • Chapter 4 Settlement >
        • Settlement Patterns
        • Student work
        • Student work 2
      • Urban Sprawl-Introduction
      • Chaper 5 Three urban land use models >
        • Chapter 5: Land use change
      • Chapter 6 Urban problems in developed world cities
      • Chapter 7 Heritage Issues & Environmental Issues
      • Chapter 8 Urban planning strategies in Ireland >
        • Chapter 9 Developing world cities / counter-urbanisation
  • Culture and Identity (Hons)
    • Physical indicators of population
    • Cultural indicators of population
    • Nationality and Nation states
    • Case study: Switzerland
  • Geoecology (Hons)
    • Soils
    • Aridisoils
    • Brown earth soils
    • Latosols - Tropical rainforest soil
    • Soil Formation
    • Soil erosion - human activities
    • Soil erosion - preventative methods
    • Biome: Tropical rainforest
  • Field Investigation
    • 2013 field study
  • Exam and Papers
    • Leaving Cert Exam
    • Honours Paper
    • Ordinary Paper
    • What do I study?
  • Revision Centre
    • Physical Revision >
      • Physical Powerpoints
      • Plate tectonic questions
      • Volcano & Earthquake questions
      • Rock revision
      • River Revision
      • Glaciation Revision
    • Regional Revision >
      • Regional Powerpoints
      • EU expansion revision
      • European Regional Revision
    • Elective Revision >
      • Human Elective Powerpoints
      • Economic short questions (H&O)
    • Geoecology Option >
      • Geoecology Powerpoints
      • Geoecology questions
    • Sample Answers >
      • Sample Answers Outline
      • Physical: Sample Answers >
        • Waterfall: River Landform
        • Delta: River Landform
        • Cirques: Glacial landform
        • Drumlin: Glacial landform
        • Cave,Arch,Stack,Stump: Coastal landform
        • Beaches: Coastal landform
        • Isostatic and Eustatic Processes
        • Human control of natural processes
        • Impact of Flood Control
        • Impact of Coastal Management
        • Landform in a Karst landscape
        • Weathering and Erosion
      • Regional: Sample Answers >
        • Regions are areas defined by one or more criteria (two discussed)
        • Agriculture in Irish region influenced by factors
        • Development of agriculture in Mezzo influenced by factors
        • Development of agriculture in Paris Basin influenced by factors
        • Development of secondary activities in a Core Region
        • Industry in The Greater Dublin Area
        • The Gaeltacht
        • Climatic Region: The Cool Temperate Oceanic Climate
        • Tertiary activities in the Paris Basin
        • Two EU policies and their impact
        • EU expansion and the impact on a member state
        • The defining role of Culture (India)
        • Urban Growth : Kolkata, India
        • Growth of an urban area Paris
        • Culture defining a region - India -outline
      • Elective: Sample Answers >
        • Migration
        • Overpopulation
        • Three Urban Models
        • Geoecology: Sample Essays >
          • Soil Formation
          • Characteristics of soil
          • How human activities can accelerate soil erosion
          • Natural processes and soil
          • Tropical rainforest biome
          • Human interaction with a biome
        • Urban problems and solutions
        • Map work: Location of a Town
      • Swapped powerpoints
  • General Information
    • Geography at Leaving Cert level
  • Home
  • Physical Geography
    • Skills (Maps, Photos, Graphs) >
      • Ordnance Survey Map skills
      • Aerial photographs
      • Graph skills
    • Horizons Second Edition >
      • Chapter 1 Plate Tectonics
      • Chapter 2 Folding and Faulting
      • Chapter 3 Earthquakes
      • Chapter 4 Volcanoes
      • Chapter 5 The rock cycle
      • Chapter 6 Weathering
      • Chapter 7 The Karst Landscape
      • Chapter 8 Mass Movement
      • Chapter 9 Rivers
      • Chapter 10 Coastal Studies
    • Planet and People physical chapters >
      • Plate tectonics >
        • Plate Tectonics 2
        • Plate Tectonics 3
      • Rock Formation and Cycle >
        • Rocks
        • Rock types and their formation
        • Rock Cycle
        • Rock Cycle 2
        • The Rock Cycle 3
        • Rock Landscapes: Limestone
        • Intrusive and Extrusive volcanic landforms
        • Human interaction with the rock cycle
        • Tara Mines case study
      • Folding and Faulting
      • Weathering and Erosion
      • River processes and features
      • Glaciation
      • Coastal Studies >
        • Coastal Studies Ms. Carr
  • Regional Geography
    • Horizons Regional Chapters >
      • Chapter 22 Concept of a region
      • Chapter 23 The Western Region
      • Chapter 24 The Greater Dublin Area
      • Chapter 25 The Paris Basin
      • Mezzogiorno: Peripheral European region
      • Subcontinental India
    • Planet and People Regional Chapters >
      • Regional Geography Outline
      • Definition of Regions
      • Ireland: The Greater Dublin Region - Core
      • West of Ireland - Ms. Carr
      • The West of Ireland : Peripheral Region
      • Core region: Paris Basin
      • European Regions (Core Periphery) >
        • Paris Basin: Ms. Carr
        • Mezzogiorno - peripheral region
        • Mezzogiorno: European Peripheral Region
      • Subcontinental Region: India >
        • Introduction
        • India: Powerpoint
        • India: Secondary Activities
        • India: Tertiary Activities
        • India: Ms. Carr
      • EU enlargement
  • Elective: Human Environment
    • Folens: Human Elective >
      • Chapter One: Populations
      • Chapter 2 Human development and overpopulation
      • Chapter 3 The dynamics of settlement
      • Chapter 4 Migration
      • Chapter 5 Urban problems
      • Chapter 6 Urban settlement and planning issues
    • Planet and People: Human Elective >
      • Chapter 1: Population Studies >
        • Population test
      • Chapter 2 Overpopulation in Sudan >
        • Overpopulation question
        • Overpopulation and Resources
      • Chapter 3: Migration >
        • Migration Test
        • Student presentations
        • Student Presentations 2
      • Chapter 4 Settlement >
        • Settlement Patterns
        • Student work
        • Student work 2
      • Urban Sprawl-Introduction
      • Chaper 5 Three urban land use models >
        • Chapter 5: Land use change
      • Chapter 6 Urban problems in developed world cities
      • Chapter 7 Heritage Issues & Environmental Issues
      • Chapter 8 Urban planning strategies in Ireland >
        • Chapter 9 Developing world cities / counter-urbanisation
  • Culture and Identity (Hons)
    • Physical indicators of population
    • Cultural indicators of population
    • Nationality and Nation states
    • Case study: Switzerland
  • Geoecology (Hons)
    • Soils
    • Aridisoils
    • Brown earth soils
    • Latosols - Tropical rainforest soil
    • Soil Formation
    • Soil erosion - human activities
    • Soil erosion - preventative methods
    • Biome: Tropical rainforest
  • Field Investigation
    • 2013 field study
  • Exam and Papers
    • Leaving Cert Exam
    • Honours Paper
    • Ordinary Paper
    • What do I study?
  • Revision Centre
    • Physical Revision >
      • Physical Powerpoints
      • Plate tectonic questions
      • Volcano & Earthquake questions
      • Rock revision
      • River Revision
      • Glaciation Revision
    • Regional Revision >
      • Regional Powerpoints
      • EU expansion revision
      • European Regional Revision
    • Elective Revision >
      • Human Elective Powerpoints
      • Economic short questions (H&O)
    • Geoecology Option >
      • Geoecology Powerpoints
      • Geoecology questions
    • Sample Answers >
      • Sample Answers Outline
      • Physical: Sample Answers >
        • Waterfall: River Landform
        • Delta: River Landform
        • Cirques: Glacial landform
        • Drumlin: Glacial landform
        • Cave,Arch,Stack,Stump: Coastal landform
        • Beaches: Coastal landform
        • Isostatic and Eustatic Processes
        • Human control of natural processes
        • Impact of Flood Control
        • Impact of Coastal Management
        • Landform in a Karst landscape
        • Weathering and Erosion
      • Regional: Sample Answers >
        • Regions are areas defined by one or more criteria (two discussed)
        • Agriculture in Irish region influenced by factors
        • Development of agriculture in Mezzo influenced by factors
        • Development of agriculture in Paris Basin influenced by factors
        • Development of secondary activities in a Core Region
        • Industry in The Greater Dublin Area
        • The Gaeltacht
        • Climatic Region: The Cool Temperate Oceanic Climate
        • Tertiary activities in the Paris Basin
        • Two EU policies and their impact
        • EU expansion and the impact on a member state
        • The defining role of Culture (India)
        • Urban Growth : Kolkata, India
        • Growth of an urban area Paris
        • Culture defining a region - India -outline
      • Elective: Sample Answers >
        • Migration
        • Overpopulation
        • Three Urban Models
        • Geoecology: Sample Essays >
          • Soil Formation
          • Characteristics of soil
          • How human activities can accelerate soil erosion
          • Natural processes and soil
          • Tropical rainforest biome
          • Human interaction with a biome
        • Urban problems and solutions
        • Map work: Location of a Town
      • Swapped powerpoints
  • General Information
    • Geography at Leaving Cert level

Introduction 
The river is often divided into three parts or stages. The table below will remind you of some of the main features of each stage.

Upper course (steep gradient)
Vertical (downward) erosion Source; Tributaries; V-Shaped valley; Interlocking spurs; Waterfalls; Rapids; Gorges

Middle course (gentle gradient) Lateral (sideways) erosion  starts; Transportation, River beaches (slip off slopes); Meanders; River cliffs

Lower course (very low gradient) Deposition Flood plain; Ox-bow lakes;  Levées; Delta; Estuary

Erosion
The main ways in which erosion  happens are:
Corrasion - Wearing away of  the river bed and banks by the load hitting against them.
Attrition - Wearing down of  the load as the rocks and pebbles hit the river bed and each other. 
Hydraulic Action - Breaking  away of river bed and banks by the sheer force of the water getting into small  cracks.
Chemical Action (Corrosion) - Water dissolves minerals from the rocks and washes them away.
Cavitation - air bubbles rise  to the top of the river, burst and send ripples outwards causing erosion of the  river banks.

Feature of  river erosion: Waterfalls
Feature of  river erosion and depostion: Meanders and Oxbow Lakes 
 
River  deposition: Levees

A levee is a feature of river deposition.  It is a wide, low ridge of sediment deposited on the river banks.  Levees are generally found in the mature and old age stages of a river.

As rivers enter the middle and lower course they have a lower velocity due to the gentle slope of these stages.  The slower movement of the river reduces the ability to carry its load (competence).  After heavy rain the river may overflow its banks and flood the surrounding land.  The flooded land either side of the river is known as the flood plain.  The floodwaters deposit a fertile layer of fine sands and silts called alluvium.  The heaviest material is dropped first (closest to the river side) due to weight and friction (between the water and land) and the lighter material is carried further by the floodwaters.  Eventually ridges of material may build up on both banks.  These ridges are known as levees.

Humans often build artificial levees or strengthen existing ones to prevent further flooding of towns and farmlands.

Examples of levees include: 
  1. The Mississippi River, (Louisiana,) USA
  2. River Po, Italy
  3. River Nore, Kilkenny.

Human  activities and Rivers

Human activity affects river channels through engineering works including channelization, dam construction, diversion and culverting (building a sewer or pipe under a road or railway line for river water to pass through). The less obvious indirect effects of point and reach changes occurring downstream and throughout the basin, however, are much more recently appreciated. These are complemented by effects of alterations of land use, such as deforestation, intensive agriculture and incidence of fire, with the most extreme effects produced by building activity and urbanisation.

Changing river channels
are  most evident in the channel cross-section where changes of size, shape and composition are now well-established, with up to tenfold increases or decreases illustrated by results from more than 200 world studies. In addition the overall  channel planform, the network and the ecology have changed. Specific terms have  become associated with changing river channels including enlargement, shrinkage  and metamorphosis. Although the scope of adjustment has been established, it has  not always been possible to predict what will happen in a particular location,  because of complex response and contingency. The ways in which changes in  cross-section relate to reach and network changes are less clear, despite  investigations showing the distribution of changes along segmented  channels.


When considering the human role in relation to changing river channels, at least five challenges persist. First, because prediction of the nature and amount of likely change at a particular location is not certain, and because the contrasting responses of humid and arid systems needs to be considered, modelling is required to reduce uncertainty. Second, feedback effects incorporated within the relationship between changes at channel, reach and network scales can have considerable implications, especially because changes now evident may have occurred, or have been initiated, under different environmental conditions. Third, consideration of global climate change is imperative when considering channel sensitivity and responses to threshold conditions. Fourth, channel design involving geomorphology should now be an integral part of restoration procedures. This requires, fifthly, greater awareness of different cultures as a basis for understanding constraints imposed by legislative frameworks. Better understanding of the ways in which the perception of the human role in changing river channels varies with culture as well as varying over time should enhance application of design for river channel landscapes.

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