Saturday, November 9, 2019

Why California is considered a hazard hotspot and how it copes

A disaster hotspot is somewhere where there is a threat of two or more hazards to the area, ranging from geophysical to hydro-meteorological hazards. This is certainly the case in California, where there are an abundance of hazards which threaten the safety of the population. These hazards include earthquakes, bushfires, landslides, flooding, drought and fog. A major threat to the 40million strong population of California is earthquakes, which are caused by a network of active faults which run under the coastline of the state, including the San Andreas Fault and the Garlock Fault. The San Andreas Fault is a conservative boundary, which can give rise to powerful earthquakes. The 1906 San Francisco earthquake was caused by a rupture on the San Andreas Fault, which is a strike-slip fault meaning it is a crack between two plates sliding past each other. This 7. 7 magnitude earthquake caused a lot of destruction in the San Francisco area, killing an estimated 3000 people and leaving an expensive bill of damage ($9. 5 billion in 2009 dollars). Much of the damage and death toll came as a result of the devastating fires which followed the earthquake, which lasted for four days. The people of California are vulnerable to earthquakes as the faults directly underlie the area and the earthquake events cannot be predicted. As California is part of one of the largest economies in the world, it can afford preventive measures such as an annual earthquake drill and building earthquake proof buildings. Drought is another prevalent threat in California, which also gives rise to wildfires due to dry grounds and air. Droughts are caused by a lack of rainfall, heightened by the onset of La Nina. A particularly bad example of a drought in California was in 1976-77 where they only had half the rainfall compared to a normal year, causing a major crop fail, which in less economically developed countries often leads to a famine disaster. Droughts lead to health problems, particularly for the young and old who are at risk of malnutrition and heatstroke. 2007 was a bad year for wildfires. Prior to these fires the area was experiencing a drought, meaning the land was dry which created good conditions for fires to spread. Across the 19 days of burning, there were 9 deaths, over 500,000 acres of land burned, along with 1500 homes. There had been a build up in bushes in the previous decades of no fires which added to the reason the fires were so destructive as they had a lot of fuel to burn on. California is also at risk of flooding, both coastal and from rivers. These events are largely caused by excessive rainfall. In 1964 the Alaskan earthquake caused a tsunami which devastated parts of California, killing 14 residents. A more recent example of flooding was in December 2010 when hundreds of people were evacuated due to more than 12 inches of torrential rain falling, causing flooding and mudslides. This again caused a lot of economic damage. Other mudslides have occurred across the recent decades, often caused by earthquakes or flooding and erosion. In La Conchita there have been two major mudslides, one in 1995 the other in 2005. The more recent event was far more destructive, burying 15 homes and killing 10 people and was caused by excessive rainfall. In conclusion California is considered a disaster hotspot because its population is vulnerable to a variety of hazards which occur quite frequently and sometimes lead on from one another, for example if there is an earthquake landslides could occur as well as the initial destruction caused by the earthquake itself. As a developed state it has invested money and time to ensure the safety of its residents as much as is possible when the events are unpredictable.

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