Flood Risk Factors

Factors Affecting Flood Risk

When the amount of water in a river is greater than the river's capacity, flooding will happen. Increasing river level is caused by increasing river discharge. There are human and physical factors that can increase discharge, and therefore cause flooding:

Precipitation

Heavy rainfall causes high runoff because the water arrives so quickly that there isn't enough time for it to infiltrate the soil.
Prolonged rainfall makes the soil become saturated, and so any more rainfall will run off instead of infiltrating.

Geology

Runoff is higher in areas that are mainly made up of impermeable soil (e.g. clay) or impermeable rock (e.g. granite).

Relief

Rainfall will reach the river channel quicker in a steep-sided valley.

Land use

Buildings and roads are usually made of impermeable materials. More impermeable surfaces mean more runoff and more discharge.
Trees intercept water and store water that they take up from the ground. Removing trees will, therefore, increase flooding risk as more water will be finding its way into the river channel.

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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