Case studies geography GCSE

Why so dry?

• Because of the high air pressure there is very little water. Villages have to survive on only 15 litres a day per family.
• Some use survial techniques. These include dew traps, Catching the morinng dew, but does not give a sufficent water supply.
• Some recycle their urine, the heat causes the urine to evaporate and condense back down as water.
• Most precipitation they get comes from the fog. This regular occurance allows them to use the natural event as a way of getting water. Fog Catchers are put up. This consists of metal wirring in which the precipation condenses. It produces upto 170 litres a day for 200 days of the year. This is a sustainable solution to their problem as the fog is regular and produces a sufficent supply of precipitation.
• People choose to live in the Atachama desert because of the fertile fishing at the coast.
• Also 3,000,000,000 tonnes of copper is in reserve every year, this means alot more employment opportunities.
• Arica is a small city in the Atachama desert. Its extreme climate and sand has attracted NASA tests space probes in this region as it is the closest climate to mars on this planet

Affects on people

July-August 2003- High pressure- depression over the British Isles      

Good Effects- Tourist industry has a large increase in sales e.g. ice cream, barbe-ques, campsites, beaches.     

Bad Effects - Less water, Drought, hottest countries lose tourists and therefore lose business, many deaths.

February-March 2006- Low pressure           

 Good Effects  - Good Skiing weather, sales increase for hat, gloves, scarfs... Wood and coal sales increase  

 Bad Effects - Hundreds of accidents on the roads, planes unable to fly, blocked roads

Damage

Causes of death

Damage

• At least 1,836 people lost their lives.
• Around 80% of new orleans was flooded
• Tens of thousands of people were stuck without food, water or medical care.
• 180,000 homes were destroyed
• Levees were breeched                                                                            

Causes of Death

• Lack of communication between rescuing agencies- A state of emergency was declared 48 hours before the hurricane struck, the evacuation order came too late, supplies were held back for 3 days, the evacuation operation never happened and helicopters took 72 hours to arrive.  
• lack of supplies - a refuge superdome was built on stilts from previous Hurricances, this had enough supplies for 15,000 people but 26,000 people turned up and supplies ran out v. quickly

Causes and Impacts

• Much Bangladesh consists of the floodplians of the Gangees and Brahmaputra rivers.
• Over half of the country lies 6m below sea level. Once the rivers overflow their banks or levees, the water can spread over vast distances, imundating roads, railways, farmland and settlements.
• Bangladesh has a mosoon climate, with most places recieving between 1800 and 2600mm of rainfall a year, the average for london is 600mm, however 80% of that total is concentrated in just 4 or 5 months, June to September.
• The period of heavy rain coicides with the hottest temperatures. These temperatures melt ice and snow in the Himalayas where the Gangees and Brahmaputra and their tributaries have their headwaters, adding to the discharge of the rivers.
• Global warming is causing glaciers in the Himalayas to melt, increasing surface runoff, and sea levels in the Bay of Bengal start to rise.
• The monthly high spring tide and the effect of tropical storms,most frequent in the summer and autumn, can prevent flood water escaping into the sea.
• Silt is brought down by the rivers and deposited within their channels. This results in the heightening of the river beds and increases the risk of flooding.