Boscastle - the most frightening flood of the decade? 09 June 2018 Learning Outcomes: You will recap knowledge on Storm Hydrographs You will investigate the Boscastle flood event, 2004.

All will recap knowledge on Storm Hydrographs Which hydrograph line shows a small drainage basin and which one a large? Notice how the large drainage basin has a much bigger peak discharge though and the flood lasts longer! A B C All will recap knowledge on Storm Hydrographs

Which hydrograph line show a drainage basin with forest and which one has bare ground?

Which hydrograph line show a steep slope in the drainage basin and which shows a gentle one?

Which line shows an impermeable surface and which shows a permeable? Remember! Water flows fastest by surface runoff. A B

This map shows the areas of the UK most at risk of flooding.

Watch this short video clip about the Boscastle floods and note down anything you think is important. http://www.youtube.com/watch?v=SxweiRNlHbo 16th Aug, 2004 Flash Flood Clip is a bit jumpy where the adverts had been cut out – you tube 4:30 Boscastle Flash FLood 1 in 400 years 'Thames' Helicopters Heavy rain - 8" 8 hours Cars

CAUSES Rain A hot day in August (16th 2004) - convectional processes Torrential thunderstorm 60 mms in two hours Tall convectional clouds The remnants of Hurricane Alex Geology Impermeable rocks (slates and granite) and clay soils Human Built beside the sea at the end of the narrow river valleys CAUSES Valley shape Steep sided deep valleys of the R. Valency and the R. Jordan The valleys funnel the water down towards Boscastle Small ‘flashy’ catchments that funnel water into rivers quickly - 23 sq. km Rivers run off the high ground of Bodmin Moor (relief rainfall)

What were the impacts of the Boscastle flood? 09 June 2018 What were the impacts of the Boscastle flood? Learning Objectives: 1 – To recall the causes of the Boscastle flood. 2 – To understand the effects of the flood on local people.

Boscastle, Cornwall

Floodwater gushed into houses, shops and pubs destroying them

Cars, walls and even bridges were washed away

The church was filled with 6 feet of mud and water

Trees were uprooted and swept into people’s gardens

The shear weight of the water eroded river banks, damaged gardens and pavements

Rescue operations included helicopters, lifeboats and the fire service

Over 50 cars were destroyed

Tourism in the area was badly affected.

Local wildlife and the environment was damaged Coastal pollution was caused as debris from cars (eg fuel) flowed into the sea

The major re-build caused continued disruption

Many people were traumatised and suffered long-term stress and anxiety

How did people respond to the Boscastle flood of 2004? 09 June 2018 Learning Objectives: 1 – To recall the key facts of both floods 2 – To compare and contrast the Boscastle and Bangladesh flood responses

Boscastle main car park. A £4.5m scheme to improve flood defences. Boscastle main car park.

The scheme stretches along the whole valley Boscastle main car park.

The river bed is being deepened by six feet to accommodate more water volume in times of flood.

Boscastle car park is being raised in height Boscastle car park is being raised in height. This will stop the river from bursting it’s banks so easily.

This drain allows water to run into the lower section of the river quickly.

A concrete culvert running behind a row of eight cottages A concrete culvert running behind a row of eight cottages. This diverts the river water away from the cottages and takes it to a lower part of the river.

The river channel is being made deeper and wider so that it can accommodate more water. The lower section of the village.

New sewer systems are being put in place The lower section of the village.

Notice attempts to draw in much needed custom. Bridges that hindered the drainage of the floodwater are being replaced by stronger bridges that are less likely to get blocked. Notice attempts to draw in much needed custom. The lower section of the village.

The new lower bridge is an important part of the £4 The new lower bridge is an important part of the £4.6 million flood defence scheme, as it spans a channel specially widened to help reduce flood risk to local residents, homes and businesses near the harbour.  It will carry traffic as well as pedestrians and will replace the existing bridge

Many buildings have indicators to show the height of the flood water. The core of the village.