volcanoes/ earthquakes/ rivers and coasts case studies

Earthquake: Haiti, 2010

12th of January 2010 a 7.0 magnitude earthquake struck Haiti

• Stress building up along the conservative margin between the North American Plate and the Carribean plate was released. The major earthquake was followed by several aftershocks up to a magnitude of 5.0 on the Richter scale.

resulted:

• approximately 230,000 deaths, destruction of 180,000 homes and around 5,000 schools, many services were badly disrupted or destroyed. A major secondary effect was widespread chlora due to polluted drinking water.

• widespread poverty that left more than 80% of the population in poorly constructed, high density concrete buildings.

• Lack of stable goverment and medical infrastructure limited search and rescue efforts.

Responses:

• Short-term responses to the earthquake included search and rescue efforts, as well as the the import of food, water and shelter from the USA and Dominican Republic.

• Longterm responses included reparation of the damaged buildings. Besides, migration was common as people moved away to stay with their families. Also, people received cash or food in exchange for public reconstruction work and the World Bank pledged $US100m to support the reconstruction and recovery.

Volcano: Iceland, 2010

a stratovolcano in Iceland, located approximately 125 km SE of the capital

when:

• Lava eruptions in March 2010 were followed by an explosive eruption on April 14th 2010.

what happened:

• lava damaged many homes and roads and services were disrupted due to evacuation measures.

• Flooding was caused as glacial ice melted and torrents of water were flowing down the slopes of the land. Also, ash covered large plots of agricultural land, damaging the crops.

• The massive ash cloud blocked air traffic in large parts of Europe for several days, leaving tourists and business people stranded at their destinations.

Responses:

• included an emergency evacuation of more than 800 people. Longterm responses are the reconstruction of damages houses and roads and research on the effect of ash on air planes.

Coastal opportunities and hazards: Wadden Sea Islands

Opportunities:

• provides a large diversity of fish species and other seafood animals, making fishery an important industry for the local communities. Besides, tourism is well established in the area, with around 800,000 visitors annually.

hazards:

• the area is threatened by storm tides, which may cause floods that damage the unique ecosystem. Furthermore, the continuous eastward shift of the islands has eroded endangering settlements such as which may submerge in future.

Management:

• Coastal management strategies to protect the islands include dune grass planting and dune fencing. The newly planted grass traps and hold sand thereby reducing coastal erosion and encouraging the formation of new dunes. This makes the islands less vulnerable against erosion from storm surges.

Opportunities and hazards of a river: River Ganges, Bangladesh.

• Opportunities at the River Ganges:

  • Fertile land – agriculture of rice and jute that is the 4^th largest products in Bangladesh as an economy.

  • Water supply – enough for a population of 1101 per km²

  • Fish supply – Food can feed the dense population and provide jobs for the locals

  • Flatland – that can be suitable for builds.

• Hazards (flooding):

  • Human causes:

    • The dense population of the area causing some people to live on floodplains

    • Deforestation caused by the dense population.

  • Physical causes:

    • The river is located next to high winds from monsoons from the Indian ocean (a major flood every 5 years)

    • Tropical cyclones cause torrential rain, high winds and flooding

  • Management of the River Ganges:

    • Dhaka Integrated Flood Protection Project that protects helps with flood protection works, drainage system improvements, urban environment improvement and capacity building. With a total cost of $115.9 million. $15 million got funded by OPEC.

    • Rescue boats located at flood points and new flood shelters.

China: Three Gorges Dam

located on the Yangtse River in China. It is approximately 180 m high and 2.3 km wide and has taken almost 17 years to construct.

• dam has protected 10 million people from flooding

• 32 generators provide energy for 60 million people (each generagtor produces as much energy as a small nuclear powerplant), enabling China to reduce its dependency on coal.

• dam has created many jobs.

consequences:

• dam meant that 1 million people had to be moved to accomodate the reservoir and power stations.

• interferes with aquatic life, being a major threat to the White Flag Dolphin, which is already at risk from extinction.

• large masses of silt transported by the Yangtse deposit behind the dam, which reduces the storage capacity of the reservoir.

• dam lies on a fault line and could be badly affected by an earthquake.