Discuss the impacts of storm events in the British Isles and evaluate the responses to them (40 marks)
The British Isles has a Cool Temperate Western Maritime Climate which is owing to its location at the edge of a continent, between two seas and subject to the influences of five major air masses; north-westerly, south-westerly, northerly, easterly and southerly. British climate is classified as temperate as it rarely features the extremes of heat or cold, rain, drought or wind that are common in other climates. Basic characteristics of this climate include temperature, precipitation, wind and air masses.
The mean summer temperatures in the UK are lower than the average for its latitude which is due to the cooling influence from the Atlantic Ocean with its daily maximum being about 30 degrees. The average monthly values rarely exceed 16 degrees. In the winter, the average temperatures are above freezing (2-7 degrees) in coastal areas and relatively high winter values are owed to the warming influence of the sea. Oceans have an ameliorating effect on the temperature in the British Isles ad so it isn’t too hot or too cold. Also within the British Isles, precipitation occurs throughout the year yet varies in relief in upland areas, for example, western coast rainfall totals can exceed 2,500mm whereas a short distance further east in low land areas in the shadow of mountains, annual totals can be as little as 500mm. Most of the rainfall is brought by frontal systems moving from west to east, releasing moisture as they cross the land. Wind also influences our climate massively. The prevailing wind direction for the British Isles is South Westerly and this is governed by the general atmospheric circulation system. Easterly winds do occur which usually bring spells of dry weather and westerly winds also occur which can be strong and gales are associated with these, particularly during the autumn. Air masses also influence the climate – these are largely uniform bodied of air that remain over an area for a period of several days and have assumed the temperatures and characteristics of these places. These are classified by their latitude and the surface they pass over.
A depression affection the British Isles originates in the North Atlantic where two different air masses meet along the polar front. This involves two air masses; the polar maritime air which is dense, moist and cold as well as the tropical maritime air which is light, moist and warm. As the two bodies move towards each other, the warmer, less dense air from the south (the tropical maritime) rises above the colder, dense air from the north. The rising air is removed by strong upper atmosphere winds (jet stream) but as it rises, the Earth’s rotational spin causes it to twist. This twisting vortex then produces a wave at ground level in the polar front, which increases in size to become a depression. Two separate parts of the original front have now developed; the warm front, at the leading edge of the depression where warm, less dense air rises over the colder air ahead and the cold front at the rear of the depression where colder, dense air pushes against the warmer air ahead. In between these lies the warm sector – an area of warm, moist air. As the depression moves eastwards, the cold front gradually overtakes the warm front to form an occlusion in which the colder air undercuts the warmer air so that it no longer touches the ground.
Several significant storm events in the British Isles have occurred in the past decades, including the 1987 Southern England on the 15th and 16th of October. In this event, warm air from Africa met cold air from the Atlantic Ocean, causing an intense depression. The depression developed over the Bay of Biscay on 15th October and moved northwards. Weather forecasters thought it wouldn’t reach England, but by midnight it had changed course and moved towards the south coast and so most people went to bed whilst being unaware that there would be extremely severe winds overnight. The impacts of this were massive, with 19 people in England dead. 15 million trees were knocked down and trees blocked roads and railways. Power lines were taken down and 5 million homes were left without electricity. Insurance claims were up to £2 billon and so premiums increased for everyone the following year. The Met Office were criticised in the immediate aftermath of this event as it failed to forecast the storm correctly which arguably led to the death of many more people than necessary due to them sleeping through gale force 11 winds. In the aftermath, however, a great deal of money and effort was put into a post-storm ‘clean up’, yet some thought that nature would’ve been better left to re-assert itself. For example, there was unnecessary destruction of trees which, thought fallen, were still living and so could have been recovered through nature. The Met Office learnt from their mistakes in this event and so a number of recommendations were made. Observational coverage of the atmosphere over the ocean to the south and the west of the UK were improved by increasing the quantity and quality of observations from ships, aircrafts, buoys and satellites. Continued refinements were made to the computer models used in forecasting and the training given to forecasters was improved. Substantially more warnings will be put out in future in the event of a storm in an attempt to mitigate the effects for humans and therefore the response to the 1987 depression resulted in some positive aspects for the future, yet the negative impact of this storm could’ve been significantly reduced through the delivery of an accurate warning. Evidence of these improvements can be seen in the Burns’ Day Storm which occurred three years later. This suggests that the issue of the 1987 storm was of importance to the government and so received sufficient funding to create a better system as quickly as possible, yet arguably this may be due to the catastrophic effects of this event and the funding was given more as due to political reasons rather than the needs of the people.
The Burns’ Day storm which presented the improvements made since the 1987 storm occurred on the 25th January 1990. This event struck during daylight hours across Southern Scotland bringing severe gales and storm force winds to much of England and Wales, evoking memories of the storm of 1987. Wind speeds during this storm were higher in some areas than in the October storm of ’87 yet they covered a wider area and so the death toll of 47 across such a wide area was comparably lower than the storm three years previously. The disruptions to power supplies occurred as in the 1987 storm, yet the loss of trees was lower, due to the fact that during the Burns’ Day storm, the strongest winds were in less wooded areas. The response to this storm was organised and successful. An emergency meeting was set up for senior ministers and they reviewed the storm, announcing that special funds would be granted to councils in the worst affected parts of the country. Also, insurance companies estimate damages worth £750 million – in the 1987 storm, this figure was much higher (£1.2 billion) suggesting that the improvements made in the aftermath of the 1987 storm were successful in reducing the impacts of future storms. Weather forecasters that had been retrained claimed to have foreseen this 1990 storm days in advance.
The most recent of storm events in the British Isles was the Winter storms of 2013 that ran into early 2014. Overall, the UK saw at least 12 major winter storms and it was the stormiest period the UK has experienced in the past 20 years. Somerset Levels was particularly badly affected and were continually inundated with flood waters from the New Year period and severe flooding also occurred along long sections of the River Thames. At least 6,000 properties were reported as flooded in this period with transport infrastructure also being affected with many roads underwater and several villages on the Somerset Levels only accessible by boat. Large areas of crops were underwater and farmers had to evacuate livestock from flooded land.
During these winter storms, the preparation was successful. The RSPCA took people’s livestock and kept their animals somewhere safe whilst waiting for the area. The shear amount of water that there was meant that soils had already reached their full capacity and therefore there was ground water flooding in which bed rock beneath soils and above soils are completely saturated (its aquifers are full) and therefore it rises up through the ground. The full extent of this storm was unprecedented with 12 storm events over three months that left no time for the ground to dry out. The ground water flooding that resulted from this had a major impact on people whose homes were flooded after the rain due to water rising above ground levels and causing the ground to bulge. In these circumstances it would be difficult to prevent such effects even with sufficient flood defences and river management and therefore this suggests that no amount of preparation could’ve prevented the impacts in this event.
Overall, responses to storm events can only be successful to a certain extent as when the volumes of water are as large as in the 2013 storm events, there was little more flood management that could have prevented its impacts. People argued that the use of dredging wouldn’t have prevented what occurred as the amount of rainfall was too high for this flood defence to prevent flooding of houses due to many storms following each other in a short period of time. However, it is clear that in the 1987 storm, more precautions could’ve been taken to prevent the death of 19 people as the weather forecasting was very poor and therefore people were unprepared for such an event. In the aftermath of this storm, however, improvements were made to prevent such an event reoccurring and this proved highly successful in the 1990 storm. The 2013 storms show that despite these improvements in technology and training, there is little that can be done to prevent such impacts when the amount of rainfall is so high and the aquifers reach full capacity.