GCSE Geography - Natural Hazards Case Studies

CAUSES Lies south of the Sahara 12° N and 17° N. Cause of drought: Moist, rainy air prevented from moving north from the Equator. 1984 – 1985 and 2006 DESERTIFICATION from non-appropriate farming method.

IMPACTS 1984 – 1985 over a million people died in Ethiopia. Animals die, crops fail, people migrate to find food, disease. Absolute poverty.

RESPONSES 1984 – 1985 “Live Aid” – 1st global media aid request – leads to expansion and awareness of aid agencies work 2006 – Migration of people leads to armed clashes and fighting. Increase in use of fuelwood and growing population means greater risk of further drought. Oxfam etc provide appropriate, sustainable technology.

CAUSES Strato volcano - dormant Series of minor earthquakes and steam explosions.  Pumice fragments and ash from side of vent. Lava erupted from summit crater accompanied by heavy rainfall. Hot ash and rocks transported by pyroclastic flows of clouds of gas and  ash. Rapid snow melting causing floods to sweep loose debris and soil to  create hot lahars down the mountain

IMPACTS 40m deep mud deposited in valleys in path of lahars 5000 homes destroyed by floodwaters or buried by ash and mud. 23,000 people killed, mainly buried in their homes by mud. 5,000 people injured. Temperature from lahars created breeding ground for fungi and  bacteria. Many people killed by infections which could not be treated  by known antibiotics. Roads blocked impeding rescue attempts.

RESPONSES 7.00pm 13.11.1985 - Red Cross ordered evacuation of Armero at foot  of volcano following initial ash and pumice fragments. 7.30pm 13.11.1985 – Evacuation called off after ash stopped falling. Presidential election cancelled. Guerrilla fighters stopped fighting. Eruption happened at same time as Mexico earthquake so aid reduced. Rescue workers, doctors, nurses and engineers from around the world  sent to help. Eruption cost Columbia US $7.7 billion – 20% of the country’s GDP at  the time

CAUSES Deeply buried blind fault – where the fault does not reach the surface. Transform fault boundary. Key facts: 6.7 on Richter Scale. 4.30am local time. 30km north-west of Los Angeles. Depth of 18km. 

IMPACTS 57 people killed, 9000 injured. 15,000 aftershocks. Most damage in multi-storey wood frame buildings. Extensive damage to parking structures and freeways. Landslides in mountainous areas. Blocked roads, damaged water lines, broken gas pipes led to fires. Sports stadiums damaged. Liquefaction occurred.

RESPONSES Area declared a federal disaster by President Clinton. Federal Emergency Management Agency (FEMA) sent rescue and aid workers. More than 600,000 people applied for disaster assistance. Millions spent on disaster recovery. PPP – Prediction, planning and prevention. Buildings reinforced, new buildings must meet earthquake proof standards. Monitoring equipment installed to measure before, during and after earthquake.

CAUSES 25.8.2005 Sea Temperatures in the Gulf of Mexico = 32° C. Highest recorded wind speed = 175mph. Highest rainfall = 250mm. Highest storm surge = 8.5m. States affected = Louisiana, Mississippi, Alabama. New Orleans = 6 feet below sea level.

IMPACTS Levees and flood walls breached. Flooding up to 3m high. 1836 dead, over 10,000 homeless. 3 million without electricity. Roads and bridges damaged. People stranded in record temperatures of 85°F. Shortage of food and clean water. Bodies contaminated water supply.

RESPONSES 27.8.1005 – US Coast Guard relocated equipment inland. 27.8.2005 – President Bush declares state of emergency but NOT in coastal areas like New Orleans. 28.8.2005 – 1.2 million people ordered to evacuate AFTER Hurricane Katrina had hit. Motorways jammed, no public transport. Very few people had insurance and remained in poor, derelict home.