Storm Hazards Flashcards
(27 cards)
What is a tropical storm?
A tropical storm is a low pressure, spinning storm with high winds and torrential rain.
What are the conditions needed for a tropical storm to develop?
Temperature: Ocean temperatures must be at least 26-27 degrees Celsius and to a depth of at least 70 metres. Warm water provides the storm with energy.
Air Pressure: Must be in areas of unstable air pressure, usually areas where high and low pressure meet (convergence) so warm air can rise more readily and clouds can form. Warm air rises because it is less dense than cold air
Wind shear: Winds must be present for the swirling motion to form, but not too strong or the storm system will be ripped apart in the early stages. Low wind shear.
Rotation: Most originate in the intertropical convergence zone at latitudes between 5 degrees and 25 degrees north and south of the equator. The Coriolis effect is the effect of the Earths rotation on weather events. The storm spins because the Earth is spinning, but there is no Coriolis effect in the Equator, hence why these storms will only form a certain distance away from it.
A trigger: a pre-existing thunderstorm, a spot of very high sea surface temperature, an area of low pressure and many other factors can act as a trigger for a storm to develop, which will only
further develop when the other conditions are present
.
What is the formation of tropical storms?
- Warm, moist air rises, leaving an area of low pressure below
- When the warm air rises, it cools, condensing into thunderstorm clouds.
3.The whole system is spinning due to the Coriolis effect storms spin anti-clockwise in the northern hemisphere and clockwise in the southern hemisphere.
4.The constant additions of energy, from the warm air causes the storm to spin faster and generate higher wind speeds
- The eye of the storm is in the centre. This is an area spanning around 30 miles wide of extremely low pressure
6.Surrounding the eye is the eyewall .Warm, moist air rapidly rises here with, the most intense and powerful area of the storm with extremely high winds and torrential rain.
7.When the tropical storm reaches a coast, the low pressure and high winds will cause a large amount of sea water to be taken into the system and then released as a high wave called a storm surge.
8.When the storm reaches land, it no longer has a supply of energy (warm, moist air from the sea) and the eye eventually collapses. Heavy rain can persist for days.
Primary hazard/ high winds
High Winds of over 300km/h and are therefore very strong. Hurricane winds are strong enough to blow a house down, and also blow heavy debris at high speeds, which can cause damage and injure anyone who comes into contact.
Primary hazard/ storm surges
Storm surges account for approximately 90% of tropical storm deaths. Waves over 5 metres high can devastate coastal communities by destroying buildings and roads and contaminating agricultural land with salt from the influx of sea water. Communities can be protected from surges by maintaining coastal wetlands or mudflats, which absorb the water and energy produced during a storm surge. These can act as a natural barrier, protecting homes and businesses from flooding and wind damage.
Primary hazard/coastal flooding
Heavy rain- coastal/river flooding from storm surges and heavy rain River flooding also sends more floodwater to other places, which can cause areas outside of the tropical storm’s path to flood also.
Flooding damages housing and standing water combined with warm temperatures can become breeding ground for mosquitoes and associated diseases such as Malaria.
Hazard/ Landslides
Landslides due to soil becoming heavy when wet with high levels of rain.
Spatial Distribution of tropical storms
-Originate in tropical latitudes, the region that experiences the most tropical storms is Eastern Asia, other regions include the East Pacific, West Australia and the Caribbean.
Tropical storms are known by different names which is dependent upon where they originate. Typhoons is the term used in Asia, while hurricane is used for storms in the Atlantic and Northeast Pacific. Cyclone is the term used in the South Pacific and Indian Ocean.
-Most originate in the intertropical convergence zone, at latitudes of between 5 and 25 degrees North and South of the equator.
Magnitude of tropical storms
Measured on the Saffir-Simpson Scale (A scale of 1-5) based on wind speed and thus power of the storm.
Category 1: 74-95 mph
Category2: 96-110 mph
Category 3: 111-129 mph
Category 4: 130-156 mph
Category 5: 157 plus mph
Frequency of tropical storms
Tropical storms form in the Northern Hemisphere from June November, and the Southern Hemisphere from November-April. The majority of tropical storms do not develop into strong storms and do not reach land. Tropical storms that are higher magnitude and reaching land are though to be increasing in frequency.
Regularity of tropical storms
Tropical storms are irregular because although they occur in the same areas thy do not follow a set route. The route dependent on the storm and the climatic conditions.
Predictability of Tropical storms
-Track forecast cones plot the tropical storms predicted path.
-Supercomputers five day warnings and predict a location within 400 kilometres
-In the USA, the National Hurricane Centre and Joint Typhoon warning System provide courage of the Atlantic and Pacific oceans respectively.
-From past storms and climatic trends, the probability of a storm hitting an area can also be predicted. Scientists have predicted how many years it will take for a tropical storm to hit certain areas.
Monitoring of Tropical Storms
-Satellites monitor cloud patterns associated with tropical storms
-The Global Precipitation measurement Satellite monitors high- altitude rainclouds every three hours, which indicates whether a tropical storm will intensify within 24 hours.
-NASA monitors weather patterns across the Atlantic using drones called Global Hawk drones.
Primary impacts - SOCIAL
- Drowning, caused by wide spread flooding
- Debris carried by high winds can injure or kill
- Buildings destroyed
-widespread displacement and homelessness
- disruptions to essential services: Storms can disrupt power, water supply, sanitation, and communication networks, leading to a range of problems.
- damage to infrastructure and livelihoods
Primary Impacts- ECONOMIC
-Businesses destroyed: Homes and businesses are damaged or destroyed, impacting insurance claims and recovery efforts
- Agricultural land damaged: Crops are lost due to flooding, wind damage, and soil degradation, leading to reduced yields and income for farmers.
-Fishing boats and equipment are damaged or destroyed, affecting the fishing industry and livelihoods.
Secondary impacts- SOCIAL
-increased risk of waterborne diseases: Flooding can contaminate water sources, increasing the risk of waterborne diseases
Looting of both domestic and commercial properties, which can lead to the loss of possessions and people may lose their jobs if the area in which they work has been particularly badly affected.
-If insurance premiums rise, some people may not be able to afford them and will therefore not be fully protected against future storms.
Secondary impacts- ECONOMIC
-Rebuilding and insurance pay-out costs
-Economic decline from sources of income being lost
-Business Disruptions: Evacuations, closures, and damage to businesses can lead to losses in revenue and employment
-Damage to ports, roads, and other infrastructure can disrupt the flow of goods and services.
-Repairs, recovery efforts, and increased insurance premiums can all add to the overall economic burden
-Exports lost/ oil prices may increase because of difficulties with oil extraction and transportation.
Primary impacts- ENVIROMENTAL
-As many affected areas are coastal, storms can result in sensitive ecosystems being damaged and plant and animal habitats lost. Example freshwater fish may be killed during a storm surge
-flooding and mudslides can lead to communication and infrastructure being destroyed which can hamper the rescue effort
-Beaches eroded
-Sand displaced
- Coastal habitats such as coral reefs are destroyed
Landslides and Soil Erosion: Heavy rainfall can weaken slopes, causing landslides that bury houses and block roads.
Secondary impacts- ENVIRONMENTAL
- Animals displaced from flooding e.g. alligators
-Water sources changing course from blockages
-River flooding/ salt water contamination
Primary impacts- POLITICAL
-Government buildings destroyed
Secondary impacts - POLITICAL
-Issues may arise paying back international aid
-Pressure on the government to do more about global warming
-Tropical storms can highlight vulnerabilities in infrastructure, disaster preparedness, and environmental policies. This can lead to changes in government policy and regulations to improve resilience, strengthen emergency response
Short term responses
Evacuation-When a storm is predicted, authorities evacuate residents from high-risk areas.
Rescue and Recovery: Emergency services respond to rescues, search for survivors, and recover bodies.
Temporary shelters are set up, and aid agencies provide food, water, medical care, and other essentials
Digital maps and satellite imagery are used to monitor storm damage and support rescue efforts, while social media platforms like Facebook are used for reporting and gathering information.
Efforts are made to prevent the spread of disease, particularly waterborne diseases, by providing clean water and sanitation
Long term responses
-repair and rebuild properties
-rehouse people
-repair the transport infrastructure
rebuilding and preparing for future events, involving repairs to infrastructure, strengthening flood defences, and enhancing forecasting and monitoring systems.
-provide grants and aid to people to help rebuild their homes
-improve building regulations so that properties are constructed to withstand the impacts of tropical storms better
-Offer incentives such as tax breaks to encourage economic recovery
Prevention strategies/ tropical storms
-In current climates and weather conditions, tropical storms can not be avoided
-Strategies to mitigate climate change could prevent higher category storms.
