Weather Hazards in the UK

Weather Hazards in the UK:

● Weather = description of day-to-day conditions of the atmosphere
○ Climate = average weather over a long period of time
● UK experiences many kinds of extreme weather → damage done to societies makes them hazardous
○ Extreme weather = weather event that is significantly different from usual weather → takes place over
a period of time
■ eg/ snow blizzard, heatwave
○ Main cause of extreme weather → UK is the meeting point for several types of weather from different
directions
● Hydro-meteorological hazards = natural hazard caused by atmospheric processes
○ Examples:
■ Storms
■ Flooding
■ Drought
■ Extreme cold weather
Storm events:
● UK is regularly hit by depressions (areas of low pressure)
○ Bring heavy rain
○ Trigger river floods
○ Cause storm damage to west coast of UK
■ eg/ St Jude storm (28th October 2013)
● Caused by a cluster of
strong depressions
● 160 km/h winds
○ Killed 5 people
○ Felled trees
○ Toppled lorries
● Subsequent storms brought more deaths
and disruption
○ Loss of electricity
○ Gatwick airport stalled → travellers

 

UK also experiences tornadoes
○ Tornado = rotating column of spiralling air → formation is triggered by strong heating of the ground
■ eg/ tornado in Birmingham (2005)
● Injured 19 people
● Cost £40 million to recover
Flooding:
● Flooding is caused by heavy, prolonged rainfall/strong waves brought by a depression
○ May trigger landslides as a secondary hazard → causes disruption for transport
● Different types of flooding:
○ Coastal flooding
■ Deep depression brings storm surge to a major river estuary
■ Strong winds funnel coastal water into mouth of river
● eg/ 1953 → 300 deaths because of storm surge at Thames Estuary
○ River flash flooding
■ Caused by high-intensity rainfall (mainly on steep slopes)
● eg/ 2004 → village of Boscastle, experienced 185 mm of rain in 5 hours
○ Slow-onset river flooding
■ Caused by a long period of steady rainfall → gradually saturates the soil
■ Soil becomes waterlogged → water runs into river
● eg/ 2014 → River Thames burst its banks at Henley

Surface water flooding
■ Intense rainfall collects in hollows/depressions where homes are located
● eg/ 2007 → 1000s of UK homes sufferent £3 billion damage

Drought events:
● Drought = an extended period of low/absent rainfall (relative to expected average for a region)
○ In UK → 15 consecutive days with less than 0.2 mm of rainfall = drought
● Leads to insufficient moisture for crop production
○ eg/ 1975-76 → 18-month drought in Cheltenham
■ Temperature exceeded 32° for 7 successive days
○ eg/ 2003 → drought affected large parts of Europe
■ Linked with 20, 000 deaths
Extremes of cold weather:
● Caused when depressions do not pass over the UK (as usual)
○ eg/ winters of 1946-47, 1962-63 and 1978-79 were exceptionally cold
● Weather risks:
○ Frost → crops/cattle may not survive extremes of -10°
○ Freezing conditions → over 17, 000 trains cancelled in January 2014
○ Blizzard conditions → transport stops and costly airline delays