Relief of the UK Highland Processes How a river’s cross profile changes downstream. (upland) areas, The relief (height of often over 600 Transportation - The movement of sediment along the coast Erosion - The breakdown of sediment into smaller fragments Deposition - When waves loose energy they leave behind the The long profile of a river shows the change in height of the river’s the land) of the UK metres above smaller pieces. bed from its source to its mouth. It is typically concave, decreasing in gradient downstream. can be divided into sea level; e.g. • Managing Distinctive Landscapes: The cross profile shows the shape of the river valley. uplands and the Scottish Traction - large material is rolled along the sea floor. Hydraulic Action – The force of water into cracks helps to break Highlands it up. lowlands; each have Brecon Beacons: (glaciated Middle course their own • Saltation - beach material is bounced along the sea Abrasion – Waves fling sand and pebbles against the rock. • Establish fixed point photography of key viewpoints mountains). characteristics. floor. These wear away like sandpaper. and animals Upper course • Improve sinage by renewing or replacing finger posts Lower course • Suspension - beach material is suspended and carried Attrition - Chunks of rock get knocked together and worn into to encourage people to stick to the routes. Key Lowland areas, by the waves. smaller bits • Designated footpaths and Monitoring of footpath under 200 erosion metres above • Solution - material is dissolved and carried by the Solution – Water dissolves the soluble material from the rock. • Work with local planning and housing authorities to Lowlands sea level, water. promote affordable housing schemes using local rock largely flat or • Strict control over visitors Upper Course of a River low hills; e.g. the Fens in Near the source, the river flows over a steep gradient but has limited Uplands eastern energy. England. The river erodes vertically, producing V-shaped valleys, interlocking spurs, and waterfalls. The landscape will be affected by four main factors; geology/ vegetation/ land use and Waterfall formation: culture. Many of these areas in the UK can be considered an Area of Outstanding Natural Beauty Hydrographs 1. River flows over layers of more resistant and less resistant such as the Lake District and Dartmoor. Flood management schemes rock Hydrographs show how the discharge of a river (the volume of water that is flowing in it, measured in cumecs – cubic metres 2. Hydraulic action and abrasion causes a plunge pool in the less Soft Engineering (enhancing Hard Engineering (building control Rock Type per second) changes over time. resistant rock natural processes) structures) A ‘flashy’ hydrograph has a short lag time and a high peak discharge, caused by lots of surface runoff. 3. The more resistant rock is undercut, leaving the rock unsupported IGNEOUS: This is formed from molten rock SEDIMENTARY: Most of these types of rocks are Afforestation – plant trees in the Artificial Levees – increase the 4. The overhanging rock collapses and the waterfall retreats often linked to volcanoes. The molten rock may formed under the sea. On the sea bed they were • Peak discharge is the highest discharge. upper course to increase height of the river banks to upstream, forming a gorge. cool slowly, allowing time for minerals to form buried by newer sediment, squeezed and interception to lengthen lag time, increase channel capacity. • Lag time is the delay between peak rainfall and peak large crystals, which lock together. Granite and cemented together over thousands of years to and increase evapotranspiration discharge. basalt are types of igneous rock. Igneous rocks form new rock. These rocks also include the to reduce discharge. Deepening/widening the river are very hard and durable. In the UK they form fossilised remains of sea creatures. Chalk and channel – increase the channel • mountainous areas. limestone are examples of sedimentary rocks. River restoration and managed capacity. Rising limb is the increase in discharge. flooding – restoring a river and • METAMORPHIC: Existing rocks that are transformed by great heat or pressure. These changes lead to wetlands to their natural state Dam - reduces discharge by Falling limb is the decrease in discharge the existing minerals melting and forming new minerals. Marble and slate are examples of allows a river to flood there to storing water in a reservoir. metamorphic rocks. decrease discharge downstream. • Baseflow is the discharge of the river fed by Middle Course of a River Flood diversion/relief channel – groundwater flow. Physical and Human Causes of Flooding. Floodplain zoning – allow land reduces discharge by diverting a The river now flows over a more gentle gradient, but has more uses such as parks in areas that proportion of discharge away energy (more water flowing, more quickly). The river erodes Physical: Prolonged/heavy rainfall Physical: Geology are regularly flooded and restrict from a city via a flow control laterally, creating a u-shaped valley, meanders, and ox bow lakes. This causes the soil to become saturated, Impermeable rocks prevent infiltration, housing to areas that are structure on the river e.g. the stopping infiltration and causing surface runoff causing surface runoff which decrease lag time. infrequently flooded. Jubilee River (Thames). Formation of a meander and ox-bow lake: which LANDSCAPE AND PHYSICAL PROCESSES 1. The fastest flowing water 2. Further erosion causes the increase peak discharge. Paper 1 erodes the outer bank forming a two outside bends to move river cliff; slower water causes towards each other, Human: Deforestation Human: Urbanisation deposition on the inner bank, narrowing the neck of the Clearing trees reduces interception and Tarmac and concrete are impermeable, forming a slip off slope. meander. evapotranspiration, increasing peak discharge. preventing infiltration and causing surface Drainage Basin runoff. 3.Erosion eventually cuts 4. Deposition separates the 2015 Cumbria Flood Drainage Basin The area of land that is drained by the river and its tributaries. through the neck of the old meander loop from the meander, and the fastest flow is new main channel, forming Causes of the flood: Effects: Watershed The area of high land forming the edge of the river basin redirected. an ox-bow lake. • The storm Desmond brought record high rainfall – • In Cumbria and Lancashire more than 43,000 348mm fell in a 24hr period (this still continues in homes are suffering from power cuts. some parts). • 40 schools closed Precipitation Moisture falling from clouds as rain, snow or hail. • Steep hill slopes meant that it flowed into rivers • 2 deaths quickly. • Shops shut before Christmas Interception Vegetation prevents water from reaching the ground. • Cockermouth is a small town that lies on the • Insurance company increased staff confluence of 2 rivers (the Cocker and the Derwent) • Sewage leaked into surrounding fields Infiltration Water absorbed into the soil . • Bridges collapsed Surface runoff Water flowing quickly over the surface of the land into rivers. Lower Course of a River Responses: • More than 100 flood warnings Throughflow Water flowing more slowly through the soil to the river. Near the river’s mouth, the river flows over a very gentle gradient. • The Government mobilised a full national emergency response. This included 200 military personnel. The river is transporting a large load of sediment which it deposits. • The government’s announced the 5,000 households and businesses affected would be given council tax and Groundwater flow Water flowing very slowly through rocks deep underground. There is a wide floodplain with levees, and ox-bow lakes. An estuary business rate relief. with mudflats is formed where the river meets the sea (e.g. at • Evacuation of local residents to higher/ safer ground. Transpiration Water lost through the leaves of plants. Middlesbrough on the River Tees). • Improved flood defences, The Environment Agency Mass Movement Wave cut platform - Erosional Landform Sand dunes – Depositional Landform Weathering Weathering is when rocks are broken down. There are 3 types of weathering; Waves through hydraulic action cause erosion at the foot of the cliff. This erosion of a cliff at Sand dunes are mounds of sand that are found behind sandy beaches. To form they require a large flat beach, a good supply the base forms a wave cut notch. As the notch grows the rock above it becomes unstable and of sand, strong wind and obstacles. Mechanical (physical) – When rocks break up due to water entering the cracks eventually collapses. The collapsed material is washed away and a new notch starts to form. and freezing and thawing, making the rock weak. Repeated collapsing causes the cliff to retreat. A wave cut platform is left behind as the cliff Eg: Ynyslas sand dunes are located on the west coast of Wales. Erosion of the cliffs in retreat Aberystwyth, longshore drift then transports material along the coast. Onshore 1. Rainwater seeps into joints and fractures in the rock Wind then deposits the sand into sand dunes. 2. When the water freezes its volume expands by 9% exerting pressure on the surrounding rock Longshore drift 3. With repeated freeze-thaw and angular block of the rock breaks away A form of transportation that moves sediment from one end of the coast to the other. (scree) 1. Waves approach the beach in the direction of the prevailing wind. 2. When waves break, swash pushes sediment diagonally up the beach. Waves 3. Gravity pulls the water and sediment straight down the beach as backwash. A wave is a movement of energy through water, not a movement of water. The size of the waves depend 4. Over time, sediment is moved along the coast. Chemical – Caused by chemical changes. Slightly acidic rainwater slowly dissolves on 3 factors; certain rock types • The FETCH (the distance the wind blows over the water) – The greater the fetch, the more Biological – Plant roots grow causing cracks in the rocks and animals burrow into Mass movement happens when the force of gravity acting on a slope powerful the waves will be.