Meandering Rivers WHAT IS A MEANDER?

Formation of Meanders

Point bar deposits

Point Bar Deposits Point bar deposits grows laterally through time

Meander, R. Lavant, Chichester

Floodplain Point bar deposits on the inner meander bend where there is low energy River Cliff Slip-Off Slope WHAT DO THE ARROWS POINT TO? WHICH WAY IS THIS MEANDER MOVING?

Cut bank erosion (River Cliff) Point bar deposits } Meander loop WHERE IS EROSION TAKING PLACE? WHERE IS DEPOSTION TAKING PLACE? A B C D E F

Meander on the R. Colorado WHY IS DEPOSITION OCCURING HERE?

How did these meanders form?

REVISION: What River features do you get here?

Ox Bow Lake Formation LOOK AT THE DIAGRAM & EXPLAIN THERE FORMATION

Formation of an Oxbow

Ox Bow lake on Mississippi

Levee formation

Levees WHAT DO YOU THING HUMANS MIGHT HAVE DONE TO THIS LEVEE?

Delta Formation WHAT IS A DELTA? DEPOSITON OF MATERIAL BY THE RIVER WHEN IT ENTERS THE SEA DEPOSITON OF MATERIAL BY THE RIVER WHEN IT ENTERS THE SEA WHY DOES IT DROP ITS SEDIMENT

Mississippi Delta from Space MISSISSIPPI

The Nile Delta from space River Nile

Estuary Formation The Lower Course of a river valley has been DROWNED by a rise in sea level or a fall in the land level. HOW DOES THIS DIFFER FROM A DELTA? RAISED VALLEY SIDES USING YOUR ATLAS FIND AN ESTUARY (LOOK AT THE RIVER THAMES) USING YOUR ATLAS FIND AN ESTUARY (LOOK AT THE RIVER THAMES)

USING YOU ATLAS LOCATE THE RHONE DELTA USING YOU ATLAS LOCATE THE RHONE DELTA The Rhone Delta

The Rhone Delta S. France Look at p39 and identify the KEY FEATURES CAN YOU SEE IN THE SATELLITE PHOTO? Look at p39 and identify the KEY FEATURES CAN YOU SEE IN THE SATELLITE PHOTO?

The Rhone Delta WHY HAS A DELTA FORMED HERE? LOOK AT P 39 WHY HAS A DELTA FORMED HERE? LOOK AT P 39

Summary of valley characteristics

The River Tees TRY AND FIND THE RIVER TEES IN YOUR ATLAS HINT LOOK AT THE MAP TRY AND FIND THE RIVER TEES IN YOUR ATLAS HINT LOOK AT THE MAP

Land Use in Drainage Basin of River Tees WHAT IS THE AREA IN EACH BOX?

Upper Tees WHAT HUMAN INFLUENCES EXIST IN THE MAPS? COW GREEN RESERVOIR

The Upper Tees Cronkley Scar WHAT LAND USES CAN YOU SEE IN THE PHOTO? WHAT ARE THE KEY GEOGRAPHCIAL FEATURES YOU CAN SEE IN THE PHOTOGRAPH WHAT ARE THE KEY GEOGRAPHCIAL FEATURES YOU CAN SEE IN THE PHOTOGRAPH MOORLAND STEEP VALLEY SLOPE DEBRIS TURBULENT RIVER CHANNEL TURBULENT RIVER CHANNEL

Upper Tees WHAT IS THE NAME OF THE WATERFALL?

The Lower Course Tees HOW HAS THE RIVER AND LAND USE CHANGED? HOW HAS THE RIVER AND LAND USE CHANGED? FLAT VALLEY FLOOR WIDE MEANDERS URBAN SETTLEMENT URBAN SETTLEMENT

WHAT LAND USE CAN YOU SEE IN THE PHOTOGRAPH? The Lower Tees TEESMOUTH ESTUARY

The River meets the Sea

LOOK AT P42 WHAT DO YOU THINK THE PHOTOS SHOW? LOOK AT P42 WHAT DO YOU THINK THE PHOTOS SHOW? WHAT IS THE FUNCTIONOF THE BARRAGE? River Management

Formation of the Mississippi River Delta Early delta More recent delta sediments Modern delta

Causes of Floods  A Flood can occur when a river exceeds its bank full stage and water will subsequently inundate the adjacent surrounding area.  Heavy rainfall - long periods of heavy rainfall will lead to an increase in surface runoff and increase in river level.  Snow melt and heavy rainfall - water in storage may be freed by Spring melts increasing surface runoff.  Deforestation - cutting down of trees leads to a reduction in interception rates and an increase in surface runoff. This may also lead to rapid erosion rates due to a lack of stability in the soil subsurface.  Urbanisation - tarmac and concrete surfaces are impermeable and lead to an increase in surface runoff.

Flood Control and Management  There are a number of ways managing floods:  1. Afforestation - planting trees increases interception rates and reduces surface runoff.  2. Dams and Reservoirs - these hold back and regulate the flow of river water. Can be used as fresh water supply and generation of HEP.  3. Diversion Channels - overflow channels which take surplus water out of a river in times of flood.  4. Channel Straitening and Dredging - smoothens the channel to increase the speed (velocity) of the river and get water out of the drainage basin as quickly as possible.  5. Artificial Levees - makes river banks higher therefore holding more water.  6. Culverts - semi circular, smooth channels increase velocity and gets water away from urban areas as quickly as possible.  7. Revetments and Channel Walls - strengthen river banks from erosion.