hazards (storm hazards and wildfires) Flashcards
describe the formation of a tropical storm
-tropical storms form in the tropics between 5 degrees and 30 degrees latitude north and south of the equator and initially move westwards owing to easterly trade winds
-the tropical storms form when ocean waters are heated to above 27 degrees celsius
-air above the sea is heated which cause moist, warm air to rise upwards and condense forming clouds
-the rising air creates an area of low atmospheric pressure so air rushes i from surrounding areas of high pressure to fill the resultant gap, creating high wind speeds
-the cyclical tropical depression grows, encompassing smaller storms and more water vapour
-due to the earth’s rotation, the coriolis force causes the storm to spin around a central region of calm called the eye
-all storms diminish as they enter land as the warm water which energises the weather system is no longer available
how are tropical storms measured
tropical storms can be classified according to the Saffir Simpson Scale which is a 1 to 5 rating based upon a hurricane sustained speed. for example, a category 1 topical storm has wind speeds of less than 74 mph whereas a category 5 tropical storm has wind speeds of over 156 mph
how is climate change impacting the frequency and intensity of tropical storms
-according to the international governmental Panel on climate change global surface temperatures were 1.1 degrees celsius higher than before 1900 and ocean temperatures have experienced warming by 0.69 degrees celsius higher than the 1901 to 2000 average.
-as hotter temperatures evaporate more water into the atmosphere it generates more fuel to energise the tropical storms. with a higher humidity atmosphere the hurricanes produce more intense rainfall
describe hurricane Ian
-Hurricane Ian made landfall in Southwest Florida as a category 4 hurricane in september 2022. the hurricane’s rainfall ranked third highest on record since 2005 with North East of Orlando receiving over 21 inches of precipitation in 36 hours - a four times larger amount than average rainfall.
-upon landfall, a storm surge measuring 10 to 15 feet in height swept inland from the sea causing the inundation of transport routes, vehicles and infrastructure and rendering residents isolated with an absence of accessibility to electricity and water supplies. this further contributed to the death of 100 people in florida alone
-the economical ramifications of hurricane Ian were significant as Florida’s economy, dependent on agriculture industry, was hard hit with 50 to 90 percent of citrus fruit plantations destroyed due to inundation
describe the responses to hurricane Ian
-before the hurricane hit, 2.5 million evacuation orders for roughly 7 million people were ordered and an extreme wind warning was issued by the US national weather service
-there were more than 1800 personnel from 26 states that were deployed to Florida to assist in response and recovery efforts
-the american red cross sent more than 1000 disaster workers to provide food and accomodation to the homeless
describe typhoon Nanmadol
-japan is frequently exposed to natural hazards due to the country’s position on the pacific ring of fire and is exposed to western pacific typhoons, of which typhoon Nanmadol was the latest to make landfall on September 18th 2022.
-upon landfall, the typhoon nanmadol presented gusts of up to 150 mph and heavy precipitation, particularly concentrated in parts of Kyushu where up to 500 mm of precipitation fell in less than 24hrs
-in Mikyazaki prefecture, the 24 hour rainfall exceeded the september monthly average; subsequently the river bursts its banks and flooded residential streets. as a result, two fatalities were recorded alongside an excess of 100 people injured
describe the responses to typhoon Nanmadol
-early warning systems predicted waves to reach heights of 14 metres, with storm surges expected across Northern and Western Japan.
-japan airline cancelled at least 335 flights that were scheduled
describe how climate change is increasing the frequency and intensity of wildfires and the Australian bushfires
-the regions of the world most vulnerable to wildfire risk tend to have a distinct seasonality to their climate regime: a wetter season which promotes vegetation growth and a prolonged dry season which is characterised by high temperatures and drought due to higher rate of evaporation drawing moisture up from the soils and leaving dry leaf litter and vegetation susceptible to ignition.
-research shows that climate change contributes to higher global temperatures and more arid environments which exacerbate the risk of wildfires. in particular, in Australia, classified as the most fire prone country globally, has experienced a month long increase in their fire season since the 1970s.
in particular, in 2019, australia experienced 40 percent below average precipitation levels alongside an annual mean temperature which was 1.52 degrees celsius above average subsequently contributing to an increased frequency of fire days. this resulted in the 2019 to 2020 australian black summer bushfires.
describe the impacts of the australian black summer bushfires
-due to the direct effect of the fire 33 people were killed whilst three quarters of the population were exposed to prolonged levels of smoke, contributing to the death of 450 people due to smoke-related illnesses
-the environmental ramifications were severe with burning of 17 hectares of land and a subsequent death toll of 1 billion animals
- Losses experienced by the agricultural community were significant, with thousands of farms affected by significant losses of livestock, placing further strain on a sector already suffering wide-spread effects of drought.
describe the responses to the australian black summer bushfires
-the australian navy evacuated 4000 residents from the town of Mallacoota as the town became cut off via road rendering the residents isolated
-due to the severity and scale of the fire over 1000 firefighting personnel were deployed from 70 countries, including Canada and New Zealand.
describe methods of managing wildfires
-raising public awareness involves educating residents on wildfires in particular with the safe use of campfires and barbeques with 90 percent of wildfires in California attributed to human agency. for example, since 1944 the Think Smokey Bear programme in California has been installed in order to urge responsible behaviour surrounding fires.
-black burning involves the removal of fuel by deliberately burning back vegetation ahead of the fire front. Despite this, spotting may occur due to embers being carries from the active fires and igniting new fire outbreaks
-defensible space can be create around properties to protect them from fire outbreaks. this may involve storing firewood away from house and pruning branches to 10 feet about ground level
