Hydrographs
Describe and explain hydrograph characteristics (lag time, peak discharge, base flow) and explain how natural influences affect hydrographs, including geology and seasonality
Hydrographs
Describe and explain hydrograph characteristics (lag time, peak discharge, base flow) and explain how natural influences affect hydrographs, including geology and seasonality
How physical and human factors exacerbate and mitigate flood risk for different places
KEY CONCEPT
task
Complete the task below from geographyalltheway.com
Read and make notes on pp 16-18
Compare and contrast the hydrographs for a rural and urban area
plenary
How would the following factors affect the shape of a flood hydrograph? (Source)
Write the factor > effect on drainage basin process > effect on shape of hydrograph
Human Impacts on Flood Risk
How urbanisation, deforestation and channel modifications affect flood risk within a drainage basin, including its distribution, frequency and magnitude
Human Impacts on Flood Risk
How urbanisation, deforestation and channel modifications affect flood risk within a drainage basin, including its distribution, frequency and magnitude
TASK 1: Discuss and list reasons why Switzerland has a high risk of flooding.
The “Wasserschloss” (the confluence of the rivers Aare, Reuss and Limmat in the Canton of Aargau) during the flood of August 2007.
CAUSES OF FLOODING IN MOUNTAIN AREAS
HUMAN
Deforestation in ski areas
Soil compaction on ski slopes
Lack of coordination between environmental agencies
Insufficient forecasting and warning
Urbanisation of rural areas
Bridge construction collecting debris blocking river
PHYSICAL
Heavy rainfall
Long periods of rain
Saturated ground > less infiltration > more surface runoff
High snow line > precipitation doesn't store as snow
Snowmelt
Steep slopes
Impermeable rock
CASE STUDY: the river aare, SWITZERLAND
The Aare River Basin, northern Switzerland.
Draw a simple sketch map of the Aare river basin.
Describe the Aare's course, naming major cities.
TASK 1
CAUSES AND CONSEQUENCES OF THE 2005 FLOOD IN SWITZERLAND
TASK
Read the document.
Highlight causes and effects using two different colours.
Transfer these to a grid in your book, separating natural and human causes and consequences.
Use this information to write an answer to the exam question below.
how engineering can prevent future flooding
DISTRIBUTION, FREQUENCY & MAGNITUDE OF FLOODS IN SWITZERLAND
Describe the trends in frequency and magnitude of flood events in Switzerland between 1972 and 2007
EXAM QUESTION
Flood Prediction
Attempts at flood prediction, including changes in weather forecasting and uncertainty in climate modelling
Flood Prediction
Attempts at flood prediction, including changes in weather forecasting and uncertainty in climate modelling
The “Wasserschloss” (the confluence of the rivers Aare, Reuss and Limmat in the Canton of Aargau) during the flood of August 2007.
river cross section
web quest: stream management strategies in switzerland
1 - THUn
Management strategies:
Flood relief tunnel (Thun)
Channel enlargement (Bern)
2 - stans, nidwalden
Management strategies:
Catchment basin
Flood relief channel
Flood proofing
3 - RIver thur
management strategies:
Channelisation (original management strategy)
River restoration
Groynes/concrete piers
River bank excavation
River bank conservation
Mobile flood embankments
4 - altstatten in st. gallen, burgdorf in bern and wasen in emmental
Management strategies:
Debris removal in Altstatten, St. Gallen
Bridge raising in Burgdorf, Bern
Flood embankments in Burgdorf, Bern
Channel enlargement in Burgdorf, Bern
Catchment basin dam in Altstatten, St. Gallen
Channelisation in Wasen, Emmental
resources
task 1
Make four groups.
Each person in the same group watches the same video.
Work together to complete the grid, using the video and the second sheet to help you.
Agree on the most important information to share.
Task 2
Make four new groups with mixed members
Share your management strategies with the group
Listen to the other students and complete the grid
practice exam question
Flood Mitigation
Flood mitigation, including structural measures (dams, afforestation, channel modification and levee strengthening) and planning (personal insurance and flood preparation, and flood warning technology).
Two contrasting detailed examples of flood mitigation of drainage basins.
Flood Mitigation
Flood mitigation, including structural measures (dams, afforestation, channel modification and levee strengthening) and planning (personal insurance and flood preparation, and flood warning technology).
Two contrasting detailed examples of flood mitigation of drainage basins.
Identify two transfers and two stores shown in the diagram.
Explain three ways in which human activity can reduce the time taken for water to pass through the system.
CASE STUDY: FLOOD PLAIN MANAGEMENT AND FLOODING IN DONCASTER, UK
Create a mind map showing the modifications to the drainage basin and flood plain which led to flooding in Doncaster, UK
EFFECTS ON SIZE AND PROBABILITY OF FLOODS
Describe what the two graphs below illustrate about human intervention on flood plains and the frequency and severity of flood events.
