Hazard Overviews
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Natural Hazards Hazard Overview PARTNERSHIP NHP June 2016 Air Pollution Impacts Overview When levels of air pollutants rise impacts may The air we breathe contains small amounts of include: pollution generated from sources such as road traffic, industrial processes, domestic heating Health impacts mainly affecting the respiratory and and cooking, and agriculture. Some pollution inflammatory systems. It is advised to consult the is also generated naturally, for example wind- Public Health England website about health blown dust and sea salt. impacts from air pollutants. Some pollution can travel long distances Environmental effects including damage to plants across countries and even continents. and crops. A haze may also occur, usually over cities, reducing visibility. Stone buildings may Pollution is normally dispersed effectively by show signs of erosion and become blackened. the wind, but when winds are very light it can build up to higher levels. Notable air quality events The amount of pollution in air is measured in micrograms per cubic metre (µg/m3). August 2003 - A heat wave across Europe in the first two weeks of August 2003 was accompanied Air pollution can make it harder to breathe, by high levels of the pollutant ozone. especially for people with existing respiratory problems. Even for healthy people it can have 5-9 December 1952 - A severe air-pollution event an impact on long-term health. occurred in London, resulting in a significant increase in the death rate. Air Pollution in the UK Pollution levels outdoors can build up at any time of year when the weather is very settled and winds are light. In urban locations the most significant pollutants are nitrogen oxides and particulates. Close to roads, levels can be much higher. During the summer a gas called ozone can build up across the whole country and can cause elevated, widespread pollution levels, including in rural locations. In general, air pollution in the UK does not rise to levels at which people need to make major changes to their behaviour or avoid going outdoors. More information can be found at: www.naturalhazardspartnership.org.uk/hazards/air-pollution Natural Hazards Hazard Overview PARTNERSHIP NHP July 2016 Impacts Fog Fog impacts are a result of reduced visibility and disorientation. They include disruption to: Overview Transport due to reduced visibility causing travel disruption. Motorists drive more slowly to prevent Fog can be defined as a type of low-lying cloud accidents, this causes delays. Airports experience resulting in visibility below 1000m. Mist is when delays and cancellations due to the reduced visibility is above 1000m. visibility. Trains breakdown when freezing fog There are 3 categories of fog: affects the overhead power lines. Aviation fog: visibility <1000m Infrastructure networks due to freezing fog on power Thick fog: visibility <200m lines which can lead to power failure in extreme Dense fog: visibility <50m situations. Fog is composed of water droplets and occurs Industry as shipping and oil platforms can be when air is at or near saturation. This occurs affected by the reduced visibility. when the air is cooled or when air moves over a moist surface. Health due to the increased likelihood of accidents on the roads. Reduced visibility in hazardous Classifications of fog depend on the physical environments such a mountainous areas can lead to process leading to saturation, the main types of accidents. fog are: radiation fog, valley fog, advection fog, upslope fog, evaporation fog. Notable fog events Freezing fog is composed of supercooled water November 2015 - Multiple airports affected including droplets that deposits rime (ice) onto surfaces 129 flights cancelled at Heathrow Airport (10% of e.g. walls, roads, pavements and cars. departures). Forecast fog related to visibility forecasts. It is December 2012 - Fog and ice across the UK. important to consider factors such as the Flights cancelled at London airports and a section of synoptic situation, time of year, stability, the A1M closed causing delays. temperature change expected, wind, dew-point temperature, movement of air of favourable underlying surfaces. Fog in the UK Fog is one of the most common weather conditions in the UK, particularly throughout Autumn and Winter and can be seen to affect inland areas of England and lowlands of Scotland in high-pressure conditions. Coastal fog (resulting from advection) regularly occurs along the East coast in Spring and Summer. More information can be found at: www.naturalhazardspartnership.org.uk/hazards/fog Natural Hazards Hazard Overview PARTNERSHIP NHP April 2016 Impacts Ice Ice impacts include: Disruption to transport from road accidents, Overview tailbacks and closed roads. Rail and bus services are delayed, cancelled or reduced with Ice forms when the temperature of water falls passengers left stranded. Airports close, with below freezing point. It can be describe glaze flights delayed or cancelled, due to de-icing of (‘black ice’), hoar frost or rime. aircraft and aircraft overshooting runways. Glaze is clear ice that forms when Disruption to energy and telecommunications from supercooled rain or drizzle falls on a subzero ice accretion on power lines, masts and pylons, surface. On a road it can be extremely resulting in damage and power cuts. dangerous as it may appear wet rather than Other disruption includes damage to buildings, icy. schools closures and pedestrian injuries from slips and trips. Hoar frost is the sparkling white frost that forms on surfaces by condensation, typically Notable ice events during a clear and cold night 9 February 2012 - Freezing rain event in Northern Ice on roads can be prevented with treatment England of salt, as salt in solution has a lower freezing December 2010 - UKs coldest December since point than water. Effectiveness depends on Met Office records began salt staying on the road as rain and strong winds may remove it. 13 January 2010 - Freezing rain event in Yorkshire Winter 2009/2010 - UKs coldest winter since 1978/1979, numerous ice events Ice in the UK Ice typically occurs during the winter months when nights are at their longest and coldest. The most common form of ice is hoar frost with favoured conditions tending to occur under ridges of high pressure. Ice, which generally tends to occur less often, will form where surfaces are wet and then freeze. This may be caused by compacted or melting snow, or the conditions which follow the passage of a cold front. Glaze is formed by freezing rain, which although is very rare in the UK, can occur when a warm front approaches with a very cold undercut of air. More information can be found at: www.naturalhazardspartnership.org/hazards/ice Natural Hazards Hazard Overview PARTNERSHIP NHP April 2016 Near Earth Objects Impacts Overview Depending on where the NEO hits and its size the Near Earth Objects (NEOs) are asteroids or impacts can be minimal to severe. A NEO strike comets that pass close to the Earth. can result in impact and blast waves, heat and electromagnetic pulses and tsunami waves which Potentially hazardous NEOs are estimated to can all cause impacts including: be greater than 20m in diameter. Major disruption to all services including transport, energy and telecommunications. Asteroids reside in the asteroid belt within the inner solar system whereas comets originate Damage to buildings. from the Kuiper belt in the outer solar system. Health impacts. Their relatively stable orbits can be perturbed gravitationally so that their paths can intersect Longer term environmental/climate affects caused the trajectory of the Earth, possibly resulting in by material being re-suspended in the atmosphere. a collision. Notable near earth object events NEOs greater than 1km in diameter are 15 February 2013 - an object entered the termed planet killers as they would atmosphere over the Russian city of Chelyabinsk destroy/disrupt life. resulting in significant structural damage and numerous minor casualties. 1908 - an asteroid broke up over Siberia (at the Near Earth Objects in the UK same latitude as London), the resulting blast wave The UK’s land mass is a relatively small target laying waste to an area the size of Greater London from space but as NEO impacts are indiscriminate (within the M25). and likely to be regional in extent, the UK could be affected by a land impact in continental Europe or tsunami from ocean impacts bordering our coastline. The United States of America leads discovery and tracking survey programmes using optical telescopes. NASA and the European Space Agency determine the likelihood of an impact with the Earth. The UK Space Agency, as part of a UN led initiative called Space Mission Planning Advisory Group (SMPAG), is involved in activities to prepare for an intercept mission, should it be needed, to deflect or destroy an incoming NEO. More information can be found at: www.naturalhazardspartnership.org.uk/hazards/near-earth-objects Natural Hazards Hazard Overview PARTNERSHIP NHP April 2016 Space Object Re-Entry Impacts Overview Space object re-entry impacts include: Space objects are man-made objects which include satellites and space junk. Space junk Damage on the ground, including buildings and can be abandoned satellites, broken pieces or infrastructure caused by the object striking the parts of rockets, all vary in size. ground. All space objects launched into Earth orbit will Damage to aircrafts in flight caused by the object return although orbital lifetimes can vary from colliding with the aircraft. hours to hundreds of thousands of years. Health impacts directly from being hit by an object. Since the beginning of the space age, objects have returned to Earth on a daily basis. Many Notable space object re-entry events objects burn up completely as they pass 2008 - Missile intercept of USA 193 to prevent the through the upper atmosphere or fall into the intact satellite re-entering potentially contaminating sea unobserved.