Physical landscapes River landscapes in the UK

Transcription

1 Physical landscapes River landscapes in the UK

2 The shape of river valleys change s as rivers flow downstream - PROCESSES Erosion Abrasion or corrasion Attrition Hydraulic Action Solution or corrosion Deposition Why does deposition occur? T S S S Describe reasons why a river s energy decreases. Challenge: What is the Hjulstrom Curve?

3 Which processes are operating where? EROSION TRANSPORTATION DEPOSITION UPPER COURSE MIDDLE COURSE

4 Where does most of the vertical erosion take place? Why? Where does most the Lateral erosion take place? Why? LOWER COURSE Explain what happens to the discharge and velocity as you more downstream.

5 What are the features of a river? Upper / Middle / Lower? Feature Floodplain Description UPPER Upper, middle and lower - Draw, label and describe the formation of the features located along the Plunge pool Ox-bow lake Waterfall Meander V-shape valley How is a V-Shape Valley formed?

6 MIDDLE As water travels from the upper rive r section to the river section. There is less pull from, therefore there is less erosion and more erosion. The sideways movement of water causes it to flow on the outside bend, as such the water has more and erosion Takes place forming a, the water slows down on the which means the water has energy, and so occurs forming a. Missing words: Gravity, Middle, lateral, vertical, energy, faster, inside bend, River Cliff, deposition, less, slip-off slope.

7 Lower Floodplains and L evées ( where land is worn away) and ( where sediment is laid down by the river) processes. floodplain) has the effect of the floodplain over hundreds of years. Deposition is also important. When the river, it spreads out over the floodplain. Next, this slows the river down as the river is in contact with more. This causes deposition of, the rocks and most of Words to use: widening, deposition, floods, Lateral, levees, friction, largest, erosion, further, sediment, layered Firstly, floodplains are formed by a combination of both

8 erosion (where the river erodes from side to side across the the sediment is dropped closest to the river channel, the finer material is dropped away. Finally, this creates a floodplain and levées.

9 Casestudy River Tees, an example of a river valley To know an example of a river valley in the UK to identify its major landforms of erosion and deposition. To know named Erosional and depositional features along the River Tees To be able to explain how these landforms were formed Using your notes and research online - Add detailed notes about all of the landforms and processes and human interferences with the river occurring whilst the video plays along the Tees from source to mouth.

10 Causes of flooding Human Causes p Physical Causes p

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12 The shaded area is known as the Different factors can affect the shape of a storm hydrograph and affect its lag time: Vegetation Geology Rainfall What is a storm hydrograph? Graph definitions Base flow Rising limb Peak discharge - Falling limb Lag time Land use Relief Why are storm hydrographs important? Title:

13 Hard and soft engineering of river environments Definition Scheme How it works Diagrams or examples Costs (negatives) Benefits (positives) Dams and reservoirs Straightening meanders Embankments Flood relief channels Flood Warnings and preparation Flood plain zoning Land uses increase in value as distance from river increases

14 HUMAN PHYSICAL - Flood defences schemes failed because the discharge was larger than the channel could contain. If flowed over the walls.

15 Causes of the 2008 flood Effects Social impacts Economic impacts Evaluation of the management: The cost for Insurance for houses and business went up. 400 residents were evacuated. Farming losses were estimated at over 1million. More than 1,000 houses were affected. Damages could be over 10 million. Morpeth High Street was under 60cm of water. The library suffered severe structural damage due to the heavy debris transported by the river. Emergency services involved in rescue and recovery operations Previous floods protection failed: Walls built after the floods in the 1960s but failed and in 2008 the town flooded causing 10 million of damage. New scheme was expensive and they ran out of money: New scheme put in place included new walls and dam cost 26.5 million. Considered expensive half funded by the council and other Environment agency. They ran out of money and were short 1.5 mill. Environmental concern: The new scheme put in place threaten habitats such as the cray fish. (Evaluation did lead to them being protected).

16 Coasts and Waves The coast is a narrow zone where the land, sea and atmosphere meet. It is constantly changing. Some coastlines are being rapidly eroded (broken down) while others are being slowly constructed (built up). Waves are made by the transfer of energy from the wind blowing over the surface of the sea. The stronger the wind blows, the larger the waves are that are formed. The larger the wave, the more energy it contains. Why are some waves bigger and stronger than others? (4 marks) Destructive wave: Constructive wave:

17 Erosion processes #1 Hydraulic action Physical Chemical #2 Abrasion Weathering #3 Attrition Biological #4 Solution

18 Transport Why does deposition occur? Draw a labelled diagram of longshore drift explaining how it transports sediment along the coast.

19 Discordant coastline

20 Concordant coastline Draw a labelled diagram of a spit and explain how it is formed: Cliff retreat and wave-cut platform formation Sand dune formation:

21 HARD ENGINEERING SOFT ENGINEERING Coastal management Types and their pros and cons

22 Coastal management Has it been a success or can conflicts be caused? Holderness coastline How are they protecting the coast? Lyme Regis coastline How are they protecting the coast? Success or failure? OR Success or failure?