001 - Flood Risk

Geographic Knowledge and Understanding

How urbanization, deforestation and channel modifications affect flood risk within a drainage basin, including its distribution, frequency and magnitude.


Physical and human factors exacerbate and mitigate flood risk. Understanding the processes involved and relative power of the human and physical factors facilitates how the risks can be managed.


Key Terminology

Define the terms above using the useful links below and your 'Freshwater' textbook by Codrington.

Useful Links

Activity One - Why?

The causes of flooding have been debated for some time but why is it an important type of disaster to focus on? North Western Europe is relatively lucky and does not tend to suffer from hurricanes or volcanic eruptions. What we do have to worry about is the increasing frequency of our flood events. Watch the youtube clip below and make notes on the causes and consequences of flooding in Europe in 2021 and England in 2024 due to Storm Henk.

Useful Resource

Flooding in Europe 2021

BBC News

Flooding in England 2024 January 5th

Activity Two - Magnitude and Frequency

As you are now aware hydrographs are critical in aiding Flood Agencies to predict when and where the next major flood event may occur. Generally the stronger the magnitude the lesser the frequency which is why severe floods are often referred to as a 25 or 50 year flood event. This can be illustrated in the graph below.

Flooding in Nottingham over the years

Photograph Taken by Ellena Mart

Path next to the flood record

Activity Three - Urbanisation

When we looked at flood hydrographs we began to explore the impact that urban areas had on the increased risk of flooding. Now is the time to formalise that discussion by looking at the flow chart below.

Image Three - Impact of Urbanisation on Flooding - Taken from www.geographyalltheway.com

Activity Four - Deforestation

Whenever something is built it is inevitable that trees will be chopped down to make way for the new building or road. Unfortunately as soon as you deforest an area the interception rates will be reduced, the infiltration rates may decline and this can cause an increased amount of overland flow. To assess the impact that deforestation has on flooding answer the following questions.

Activity Five - Flood Management

Many believe that flood management is a way to try and stop the issue of flooding but in some instances it can actually make things worse. If schemes are not maintained then there is a chance that dams can be breached and levees can burst. So what can actually be done to try and prevent flooding and how successful are those schemes? 

Hard Engineering

Text Book

Our Planet's Freshwater - Codrington

Exam Style Question

Explain how deforestation impacts the magnitude of flood risk within a drainage basin [3 marks].

This lesson was development in collaboration with Richard Allaway from geographyalltheway. For more resources please visit www.geographyalltheway.com