Case Study Examples: Climate, the Environment and People

A weather event caused by low pressure

(i) Name and locate a weather event that has been caused by a low pressure weather system.Hurricane Mitch, which struck Honduras, Guatemala and Nicaragua in Central America in October 1998.

(ii) Describe the weather event.Hurricane Mitch formed over the Caribbean Sea around an area of very low pressure, where the sea surface temperature was above 26°C. It started as a tropical depression on the 21st October, before increasing to a tropical storm with winds speeds of 70mph on the 23rd October. By the 26th October it had rapidly grown to a category 5 hurricane with wind speeds of up to 180 mph. There was heavy rain during the hurricane, which caused widespread and catastrophic landslides and flooding in Honduras and Nicaragua. Between 300 and 1800 mm of rain fell in total.

(iii) Explain how the weather event affected different groups of people or organisations. The hurricane killed over 11,000 people because many parts of Central America are remote and little warning of the hurricane was given. Approximately 1.5 million people were made homeless by the hurricane in Honduras and a further 500,000 in Nicaragua. There was also a lack of food, medicine and shelter for those who had been made homeless. People were forced to live in makeshift homes made of wood, cloth and other materials they could find. There was an increase in diseases such as cholera because people were forced to drink dirty water. People living in a shanty town alongside a river in Nicaragua were swept away by a storm surge and the flooding as their poorly constructed housing could not withstand the floodwaters.

70% of the banana crops in Honduras were destroyed because of the high winds and flooding in the hurricane. Therefore they were either battered and trees blown down by the winds or the trees were flooded and could not survive standing in stagnant water. The banana plantations are the main export crop of Honduras and this caused major economy damage for the country as well as unemployment for some of the plantation workers. Crop losses were estimated at over $900 million in Honduras. Over 30% of the coffee crop was lost in Nicaragua as well, causing losses to agriculture, the economy and jobs there.

In order to help the countries in Central America affected by the hurricane, aid was provided by the USA, Spain, Sweden and the UK. Over $280 million in aid was given to help Honduras, Nicaragua and Guatemala to rebuild houses, provide food, shelter and medicines.

A type of climate

(i) Name and locate a type of climate you have studied.

Maritime Climate in Britain.

(ii) Describe the main features of this type of climate (refer to the whole year).

Britain has a temperate maritime climate – it is affected by the prevailing wind coming from the Atlantic Ocean. As a result, Britain’s climate is mainly mild and wet, however, this changes according to the time of year. In summer, temperatures are warmer, with averages of 17°C, whereas in Winter, average temperatures are 5°C. Rainfall is lower in the south-east of Britain, with average rainfall of 50cm per year, whereas the north of Britain, in particular the highlands of Scotland, can receive up to 250cm per year. As a result, Britain can have heat wave conditions in summer and winter depressions, causing storms, as a result of the differing air masses affecting the British climate.

(iii) Explain how plants and wildlife or different groups of people are affected by this type of climate.

In Summer, due to warmer temperatures and occasional heat waves, elderly people can suffer from dehydration as a result of a lack of water. Children may also suffer from dehydration or heat stroke as a result of staying out in the warmer temperatures for too long. There may be higher incidences of sunstroke and sunburn as people, particularly children, stay out in the sun too long without adequate sun lotion or hats. Employers may suffer economic losses because their workers may call in “sick” at work so that they can sunbathe. Shops may benefit from the warmer temperatures in summer because more people may buy summer clothing, barbeques and food and drink for outdoor parties and picnics. The tourist industry also benefits more from warmer summers because more people are likely to take day trips or holidays in Britain.

In winter however, elderly people may again suffer from the colder temperatures and rainfall. Many elderly people cannot afford to run their central heating when temperatures get too low, and therefore there may be more cases of pneumonia and

hypothermia as a result of elderly people being affected by the cold temperatures. There may be more traffic accidents due to heavy rainfall or snow in the winter. Roads may become blocked by snow and therefore people will not be able to get to work, and businesses may lose money as deliveries cannot take place. There may be more damage to homes and businesses as a result of flooding in winter due to the wetter climate at this time of the year. Therefore, homes and peoples’ possessions may be lost or damaged, and businesses and shops may lose money as people cannot get to work or to shops to buy goods. Insurance may also increase due to flooding.

A weather event caused by high pressure

(i) Name and locate a weather event caused by high pressure.

Heat wave caused by an anticyclone across Europe in August 2003, including the UK, France, Italy, Switzerland and Germany.

(ii) Describe the weather event.

An area of high pressure over most of Western Europe brought hot, dry tropical air from continental Europe. This brought very little cloud and warm conditions to Britain and western Europe, including France, Germany, Portugal and Holland. As a result of the high pressure system, temperatures were above average, with the highest temperature recorded in Kent at 39°C. Rainfall over Europe was below average for the summer months and heat wave conditions occurred because the high pressure system lasted several weeks.

(iii) Explain how the weather event affected people and the environment.

The anticyclone caused heat wave conditions over much of Western Europe. As a result, over 20,000 people due to heat related illness - 15,000 people died in France alone, with 2,000 people dying in the UK. This was because the high temperatures caused heat stroke and as the temperatures were so high for so long, elderly people were particularly at risk, as they also suffered from dehydration. The number of cases of severe sunburn increased, and because of the hot weather, more people took time off work to sunbathe, leading to economic losses for businesses. It is estimated that 1/3 of the deaths caused by the heat wave were due to air pollution because during warmer days, air quality is poorer and this can trigger severe asthma attacks. The heat wave also caused problems for farmers as animals died due to the heat and crops failed due to a lack of water, therefore leading to higher food prices. Whereas, tourism in the UK benefitted because the higher temperatures and less rainfall encouraged people to take holidays in the UK, rather than going abroad.

The environment suffered in the heat because a lack of rainfall led to rivers drying up and river levels falling. This caused problems for river ecosystems because there was too little water in some rivers for fish and therefore fish died. The lack of rainfall led to very dry conditions across Europe and as a result of this and the intense heat, forest fires broke out. This led to a loss of forest ecosystems on a large scale across Europe.

Consequences of changes in ecosystems

(i) Name and locate an ecosystem that has been changed.

Amazon Rainforest, Brazil

(ii) Describe the main features of this ecosystem.

The Amazon rainforest has four distinct layers. The shrub layer receives very little light and therefore there are few plants living in this part of the rainforest. Those plants that do live here are shade loving plants that have adapted to living in dark conditions. There are decomposers such as fungi living on the forest floor that break down dead plants to provide nutrients. Various animals live on the forest flood and in the shrub layer including termites, frogs and snakes. The under canopy is made of younger trees that are growing quickly to reach the light. Here live animals such as monkeys and insects. The canopy layer is approximately 30 metres high and is a continuous layer of tree tops that have grown tall enough to reach the light and catch the rainfall. There are also plants that have grown in the tree tops such as bromeliads. There are many species of birds that live in the canopy layer including parrots and bats. Some animals such as orang-utans and clouded leopards have adapted to living in the canopy layer. The emergent layer consists of trees over 40m high, which have broken through the canopy layer.

(iii) Explain how this ecosystem affects the lives of different groups of people.

The rainforest ecosystem provides a home for native Indian tribes living in the rainforest. These tribes live off the rainforest ecosystem, providing them with building materials such as wood for their homes, wood for fuel and food and medicines from animals and plants. These native tribes cut down small areas of the rainforest for subsistence farming, and then move on after a few years to allow the rainforest to regrow. The rainforest has provided a living for people in Brazil. There are many natural resources in the Amazon rainforest including rubber from rubber trees and minerals such as iron ore. Therefore, the rainforest has been cut down to allow these minerals to be extracted providing jobs. The rainforest ecosystem is vast and therefore areas have been cut through the Amazon rainforest to construct the Trans-Amazonian highway. This has affected the government in Brazil as well as areas to the west of Brazil because it has opened trade routes across the country, therefore improving the economy.