Boscastle Flashflood Flashcards
(22 cards)
When was BFF?
16th August 2004
What is a flashflood?
When lots of water suddenly flow into a river, ,causing it to overflow its banks.
often caused by a short period of heavy rainfall
What are the physical causes of the flashflood?
- 75mm of rain ( the amount that would normally fall in a month) fell in just 2 hours. This was due toa low pressure system that brought warm, moist air fom the Atlantic Ocean. The air mass cooled as it rose above the land,, causing thunderstorms with intense rainfall.
- rlots of rain weeks before the flood meant that the ground was already saturated with water and could not abrorb anymore rainfall. so the raingall siomply ran off the land surface.
- Bostcastle is ina steep-sided vakkley close to the confluence of 3 rivers; Jordan, Valency and Pradaice. This means that surface wter ran into the river channels very quickly, and the confluences meant that about two billion litred of water funnelled down the river ralleys into Boscastle.
What are the human causes of the flashflood?
- there is an old bridge in the village which had a low arch over a very narrow river channel. (like a dam)
- village had a lot of concrete and tarmac surfaces, which are impermeable so water couldnt soak into the ground. This increased surface runoff, sending more water straight into the river.
- poor drainage systems ( not equiped to handle such a large volume of rainwater iin a short time, leading to fast and seevre wwater accumluations.
- it was built on the floodplain; properties and roads were built close to or within the natural floodplain, putting them directly in the path of floodwater
How many properties damaged?
58
how many businesses damaged?
4
What did destructuion of roads and bridges lead to?
cutting off access and isolatinf the village temporarily
how many people were rescued (some by helicopter)
100
HOw many people died?
miraculously, no one
How much of the local economy relied on tourism?
90%
How many cars washed out to see?
50
How many people were injured?
one was seriously injured,
rest suffered mental health problems after the flood due to stress relating to the floods and insurance claims
What did the flood defense scheme invlude?
- widening the river channel
- raising bridges
-installing a better drainage system
Give an economic long term consequence.
- total damages were estimated at 15 million pounds
-many residents faced lengthy insurance battles and rebuilding delays
Give a long term environmental impact.
environmental recovery:
- local ecosystems tok time to recover from riverbank erosion, vegeation loss and water pollution caused by debris and fuel spillages.
How much did the new flood defence scheme that opened in 2008 cost?
10 million pounds
What happened to residents and tourists that were flooded out of their accomodation?
looked after in lovcal accommodation and the village hall
What happened to the bridge?
-rebuilt with a higher arch, so that debris is less likely to dam the river
how many helicopters saved 100 people?
7
Who sorted the immediate clean up?
- firefighters and volunteers helped w clearing debris, securing buildings and restoring basic services.
What did the Environment Agency do?
worked to improve upstream land management to slow runoff.
What did the new flood warning system introduce?
- river level sensors, weather monitoring and community education about flood safety.
