Deposition

Deposition is when the sediment that a river is transporting is dropped. This happens in the middle and lower course of the river and in lower energy conditions. The reasons why rivers lose velocity and drop material are:

Reduced volume of water in the channel

Increased amount of sediment in the channel

Water becomes shallower

The river's mouth is reached

River Landforms Caused by Erosion

Waterfalls

When a river flows over hard rock that overlays softer rock, a waterfall can form.
The less resistant rock begins to erode by abrasion and hydraulic action.
A step or notch forms in the softer rock, creating a river rapid.
Over time, the softer rock is eroded more and more, whereas the harder rock is left sticking out.
The height of the drop increases as the water pounds the less resistant rock at the base. Eventually a waterfall forms.

Waterfalls and gorges

The less resistant rock starts to be eroded underneath the hard rock. This process is called undercutting.
The overhanging harder rock collapses because it's unsupported.
The waterfall now has harder rock to swirl around its base. The resulting abrasion creates a plunge pool.
Hydraulic action keeps undercutting behind the waterfall.
If the process repeats over a long time, a gorge may form.

Interlocking spurs

In the upper courses of rivers, valleys are steep and V-shaped because most of the erosion that happens is in a vertical direction.
Because the rivers don't have enough energy to erode sideways, they are restricted to winding around the hills on the valley sides.
These interlocking hillsides are the interlocking spurs.

V-shaped valleys

Vertical erosion makes the river valley deep and V-shaped.
Vertical erosion dominates in the upper course.
This is because high turbulence causes the angular particles to drag along the river bed causing erosion by the process of abrasion.
Initial abrasion causes the valley sides to be more exposed to weathering. This results in more material entering into the channel, which causes more abrasion.

1Physical Geography

1.1River Environments

1.1.1Weathering

1.1.2Mass Movement

1.1.3Erosion

1.1.4Transportation

1.1.5Deposition

1.1.6River Landforms: Waterfalls & Gorges

1.1.7River Landforms: Interlocking Spurs

1.1.8River Landforms: Flood Plains

1.1.9River Landforms: Point Bars

1.1.10River Landforms: Levees

1.1.11River Landforms: Meanders

1.1.12River Landforms: Oxbow Lakes

1.1.13River Landscape Changes: Long Profile

1.1.14River Landscape Changes: Cross Profile

1.1.15Vertical & Lateral Erosion

1.1.16Flood Risk Factors

1.1.17Human Activities on Rivers

1.1.18River Management: Hard Engineering

1.1.19River Management: Soft Engineering

1.1.20Case Study: The River Eden - Landforms

1.1.21Case Study: The River Eden - Climate

1.1.22Case Study: The River Eden - Geology

1.1.23Case Study: The River Eden - Management

1.1.24Case Study: The River Eden - Human Activity

1.1.25End of Topic Test - River Environments

1.2Coastal Environments

1.3Hazardous Environments - Tropical Cyclones

1.3.1Characteristics of a Tropical Cyclone

1.3.2Structure of a Tropical Cyclone

1.3.3Physical Hazards of Tropical Cyclones

1.3.4The Impacts of Tropical Cyclones

1.3.5Responses to Tropical Cyclones

1.3.6Vulnerability to Tropical Cyclones

1.3.7Preparing for Tropical Cyclones

1.3.8Case Study: Katrina

1.3.9Case Study: Nargis

1.4Hazardous Environments - Earthquakes & Volcanoes

1.4.1Earthquakes

1.4.2Features of an Earthquake

1.4.3Types of Earthquake

1.4.4Case Study: L'Aquila

1.4.5Case Study: Chile

1.4.6Case Study: Japan & Pakistan - Planning

1.4.7Volcanoes

1.4.8Types of Volcanoes

1.4.9Volcanic Eruptions

2Human Geography

2.1Economic Activity & Energy

2.1.1Increasing Energy Consumption

2.1.2Non-Renewable Energy - Nuclear

2.1.3Non-Renewable Energy - Fossil Fuels

2.1.4Renewable Energy - Solar

2.1.5Renewable Energy - Water & Bio

2.1.6Renewable Energy - Hydro

2.1.7Energy - Statistical Skills

2.2Rural Environments

2.2.1Rainforests

2.2.2Temperate Forests

2.2.3Characteristics of a Temperate Forest

2.2.4Goods & Services in Temperate Forests

2.2.5Deserts

2.2.6Tundra

2.3Urban Environments

2.3.1Urbanisation in Different Countries

2.3.2Causes of Urbanisation

2.3.3Consequences of Urbanisation

2.3.4Sustainable Urbanisation

2.3.5Case Study: Rapid Urbanisation in Mexico City

2.3.6End of Topic Test - Urbanisation

3Global Issues

3.1Fragile Environments & Climate Change

3.1.1Natural Causes of Climate Change

3.1.2Effects of Climate Change on the Environment

3.1.3Effects of Climate Change on People

3.1.4Impacts of Deforestation

3.1.5End of Topic Test - Climate Change

3.1.6Increasing Water Supply

3.1.7Sustainable Rainforest Management

3.2Globalisation & Migration

3.2.1Globalisation - Transport

3.2.2Globalisation - Communication Networks & Banking

3.2.3Push & Pull Factors

3.2.4TNCs & Globalisation

3.2.5Tourism Landscapes

3.2.6The Growth of Tourism

3.2.7The Economic Benefits of Tourism

3.2.8The Social & Cultural Benefits of Tourism

3.2.9The Economic Costs of Tourism

3.2.10The Social & Cultural Costs of Tourism

3.2.11Managing Tourism - Sustainability

3.2.12Managing Tourism - Quotas & Tourism Hubs

3.3Development & Human Welfare

3.3.1Ways of Defining Development

3.3.2Different Ways of Measuring Development

3.3.3Environmental Factors Causing Uneven Development

3.3.4Historical Factors Causing Uneven Development

3.3.5Economic Factors Causing Uneven Development

3.3.6Patterns of Development

3.3.7How Can we Reduce the Global Development Gap?

3.3.8Top-Down & Bottom-Up Development

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