A line of convergence formed near the coast line, where air moving in almost opposite directions collides, this helped to increase the rate of ascent and produced very heavy rain. The wind is blowing anticlockwise about the low pressure area, so the air is arriving into Boscastle from a south-westerly direction. Residents had little time to react. The flooding coincided with a high tide, making the impact much worse. A few old arch bridges got blocked up with the flood debris. Boscastle is at the confluence of three rivers – Valency, Jordan, and Paradise. It remains over the area for about six hours.
A depression brought a thunderstorm on 16 August with over mm of rain in 24 hours. The rainfall rate key shows how the colours in the image relate to the rate the rainfall is falling. Radar imagery Fig 2. Tree management – dead trees were removed to prevent them being swept away, causing blockages under bridges. About two billion litres of water then rushed down the valley straight into Boscastle. Fortunately, nobody died — thanks largely to a huge rescue operation involving helicopters — but there was millions of pounds worth of damage. Widening and deepening the river channel – this allowed the river to carry more water.
A line of convergence formed near the coast line, where air moving in almost opposite directions collides, this helped bodcastle increase the rate of ascent and produced very heavy rain.
River management – AQA – Revision 5 – GCSE Geography – BBC Bitesize
Increase in buildings within the drainage basin meant that there more impermeable surfaces which directed water back to the river faster.
Boscastle, Cornwall In August fllood, the village of Boscastle saw a month’s worth of rain fall in two hours. Many trees had been cut down for farming. Boscastle flood Emergency services on the scene of the flooded village of Boscastle. The csae also had several other key impacts on Boscastle and its inhabitants.
Raising the car park and using a permeable surface – this allowed cars to be much higher and so they were less likely to be swept away.
Floods devastate village On 16 Augusta devastating flood swept through the small Cornish village of Boscastle. Human Impacts There was a huge financial cost to the floods. A line of very heavy rain starts at bcb 1 p. Steep valley sides – water flowed into the river channel very quickly.
The weight of water eroded river banks, damaged gardens and pavements. The soils were quite thin and made up of impermeable peat soils. Boscastle is a small coastal settlement in the south west of England.
Rivers and flooding – Revision 3 – KS3 Geography – BBC Bitesize
These factors led to a flash flood which caused over one thousand homes, cars and businesses to be swept away and damaged. Rainfall rates of at least 32 mm per hour are being measured. Flood management case study: The thickest cloud is shown by the brightest white areas on the picture.
Slide show of photographs of the Boscastle flood. This link opens in a new window. Web page reproduced with the kind permission of the Met Office. Tree management – dead trees were removed to prevent them being swept away, causing blockages under bridges.
Case Study – Boscastle Floods
Rain for 12 out of 14 days in August. Boscastle is at the confluence of three rivers – Valency, Jordan, and Paradise.
Boscastle is also located on a confluence of three rivers. The Environment Agency has carried a major project to increase flood defences in Boscastle, with the aim of preventing a similar flood happening again. Physical Impacts Flooding On the day of the flood, about 75mm of rain fell in two hours — the same amount that normally falls in the whole of August.
Very heavy rain fell in storms close to the village, causing two rivers to burst their banks. For example, the red areas indicate that rain is falling at boscashle eight and 16 mm per hour. Weather chart Fig 1.
This limited interception and water went straight into the river channel. It is a warm and moist tropical maritime air mass. The drainage basin of Boscastle is steep and caase rock.
Flooding On the day of the flood, about 75mm of rain fell in two hours — the same amount that normally falls in vlood whole of August. Cars were swept out to sea, buildings were badly damaged and people had to act quickly to survive. Animation of rainfall radar.