What is the hydrological cycle? Key Theme: Rivers Number 1-7 in your book and define the terms 1.Precipitation 2. Condensation 3. Infiltration 4. Evaporation 5.Groundwater Flow 6. Surface Runoff 7. Throughflow Number 1-7 in your book and define the terms 1.Precipitation 2. Condensation 3. Infiltration 4. Evaporation 5.Groundwater Flow 6. Surface Runoff 7. Throughflow

What is the river system? Key Theme: Rivers Are these inputs, stores, transfers or outputs? Precipitation Transpiration Sea Interception Evaporation Lake Surface Runoff Infiltration Throughflow Groundwater storage Soil moisture storage

What is a drainage basin? Watershed: Watershed: The higher outer boundary between two drainage basin Mouth: Mouth: where the river enters the sea Tributary: Tributary: a smaller stream or river that flows into a larger stream or river Confluence: Confluence: where two or more steams or rivers meet Floodplain: Floodplain: a flat area either side of the river that floods Source: Source: the point where a river begins Estuary: Estuary: an area of tidal water just before the mouth Key Theme: Rivers

How might the conditions in these pictures affect the amount of water in a river?

FACTOREXPLANATION RELIEFTHE STEEPNESS OF THE LAND AFFECTS HOW QUICKLY WATER CAN REACH THE RIVER CHANNEL. (FASTER FLOW– STEEPER LAND) TEMPERATUREAFFECTS THE LOSS OF WATER FROM THE DRAINAGE BASIN AND THEREFORE THE LEVEL OF DISCHARGE. WHEN TEMPERATURES ARE HIGHER THERE IS GREATER LOSS VIA EVAPORATION. IMPERMEABLE ROCK IMPERMEABLE SURFACES DO NOT ALLOW WATER TO INFILTRATE THEREFORE THERE IS GREATER SURFACE RUN- OFF DEFORESTATIONIF TREES ARE REMOVED, WATER REACHES THE SURFACE FASTER AND THE TREES ARE NOT INTERCEPTING OR TAKING WATER FROM THE GROUND. URBANISATIONEXPANDING TOWNS CREATE AN IMPERMEABLE SURFACE. THIS IS MADE EVEN WORSE BY BUILDING DRAINS TO TAKE THE WATER AWAY FROM BUILDINGS QUICKLY– AND QUICKLY INTO THE RIVERS! FACTORS AFFECTING RIVER DISCHARGE

Hydrograph: Labels & Definitions

Which three processes shape a river? Erosion Abrasion Attrition Hydraulic Action Solution Key Theme: Rivers Sheer force of the water forcing cracks in the banks open Chemical reactions cause the rocks to break down Fragments of rock hit the bed and banks and cause it to wear away Pebbles and rocks collide with each other causing them to reduce in size Match the definition and terms

Which three processes shape a river? Transportation Traction Suspension Solution Saltation Key Theme: Rivers Minerals dissolved in the water Big boulders and stones rolled along the river bed Small stones and pebbles bounced along the river bed Very small particles are carried along suspended in the river

What fluvial landforms have we studied? Key Theme: Rivers

Look at the next 3 photos a.Which part of the river is it? b.Use evidence from the picture

Many waterfalls form when rivers meet a band of softer less resistant rock after flowing over a relatively hard resistant rock. The softer rock is worn away more quickly, and the harder rock undercut. The overhead hard rock forms an overhang, which will eventually collapse, to form a deep plunge pool. This process is repeated causing the waterfall to retreat upstream creating a gorge in its wake. Title: What is the upper course like?What is the upper course like? Title: What is the upper course like?What is the upper course like? LO: To understand the formation of a waterfall. (C)

Outline the differences between the inside and outside of a meander. (4) Explain why river cliffs form on the outside of a meander. (6) The fastest current is found on the outside of the meander. (1)There is less friction due to the depth of the water being deeper. (1) Erosion (Hydraulic Action and Abrasion) (1)happens on the outside bends and deposition occurs on the inside bends. (1) The outside bend has a river cliff whereas the inside bend has a river beach. (1) On a bend water swings outwards due to centrifugal force. (1) The fastest current is found on the outside of the meander. (1) There is less friction due to the depth of the water being deeper which leads to erosion processes such as Hydraulic Action (1) and Abrasion. (1) This erosion undercuts the sides of the bank (Lateral erosion). (1) The bank collapses over time creating a river cliff. (1)

Explain the formation of Oxbow lakes (6 marks) Due to erosion on the outside of a bend and deposition on the inside, the shape of a meander will change over a period of time Erosion narrows the neck of the land within the meander In time and usually during a flood, the river will take a new shorter route The new route will be fastest down the middle and therefore deposit material across the old meander In time this will cut off the bend creating an OXBOW LAKE Title: Features of the middle course of a river. LQ:What processes occur on the middle course of a river?

SourceMiddleMouth Large / Angular Bedrock Narrow / Shallow channel Flow slowed by friction Eroded bedrock – smoother and smaller Channel wider and deeper Less friction so faster flow Eroded bedrock – smoother and smaller Deep and wide channel Little friction resulting in a fast flow Bedrock eroded into fine silt and sand RIVER CROSS PROFILE SOURCE MOUTH

CourseGradientValley ShapeChannel Shape UpperSteep V-Shaped valley with steep sides Narrow and Shallow MiddleMediumGently sloping valley sidesWider and Deeper LowerGentleVery wide and almost flat valley Very Wide and Very Deep RIVER LONG PROFILE Long Profile- shows how the gradient of a river changes along its length. Cross Profile- shows what a cross section of a river looks like at a specific point.

Review and reflect Rivers and CoastsRiver Processes Which of these is not a form of erosion? a)Hydraulic action b)Traction c)Attrition

Review and reflect Rivers and CoastsRiver Processes What is the process called where small pebbles and stones are bounced along the river bed? a)Saltation b)Suspension c)Traction

Review and reflect Rivers and CoastsRiver Processes What happens when a river loses energy? a)No material is transported b)Transported material is deposited c) Transported material is broken up

Plenary – Quick quiz! 1.What is the start of the river called? 2.What is the term for where the river meets the sea? 3.What is the land drained by river called? 4.What is the term for when two streams meet? 5.What is the term for water travelling through soil? 6.What is the term for water travelling over the land? 7.What is the term for water lost from the leaves of tress? 8.What is the term for water travelling through rocks? 9.What is the term for water being changed from a liquid to a gas? 10.What is the term for rainfall being caught by the leaves of trees?