According to Wisner et al 2004, "disasters occur when hazards meet vulnerability,” implying that in unpopulated areas hazards can not become disasters as there is no vulnerability (Quarantelli E.L. 1998). Without humans being involved, tsunamis are nothing but giant waves; they may modify areas of uninhabited land and destroy some reefs but that does not make them disasters. Tsunamis become disasters when humans are involved; when their lives are at risk, their homes are destroyed, their livelihoods are lost etc. In addition, the economic loss caused by tsunamis could also largely effect the country as a whole. This essay will address the factors that affect the quality of human life in the 2011 Japan and 2004 South Asia tsunamis, and what made them become two of the word's biggest disasters.
Tsunamis become disasters when they result in loss of lives, injuries, and displacement of human population. In the case of South Asia and Tohoku tsunamis the coastline was densely populated leading to thousands of lives being lost as well as extensive damage to infrastructure - these were two of the greatest disasters the modern world had ever seen. The 2004 South Asia tsunami caused more than 270,000 deaths in fourteen countries across two continents (The Bolton Council of Mosques 2007-2012), whereas the Tohoku tsunami had caused approximately 20,000 deaths. This latter death toll was surprisingly high as Japan has the world's largest seismometer network, tsunami barriers and earthquake early-warning system (Cyranoski, 2011). In comparison, the Indian Ocean had no underwater warning system and therefore, the high count of human deaths in South Asia was expected. The number of casualties would have been less had Japan's early-warning system not failed, when seismologists underestimated the magnitude of the earthquake (Cyranoski, 2011). Due to the false calculation, people were only expecting a tsunami of 4-5 metres and did not feel the need to flee to higher ground, as they relied on the 20-metre thick barriers to protect them. However, there was no way the barrier could have stopped such a large wave, rising an estimated 15-20 metres at sea and 50 metres at some points after hitting the shore.
The number of casualties due to tsunamis are magnified as a result of high population densities living on coastlines. Nearly 3 billion people, or almost half the world population, live in coastal zones (Arun 2006) for a variety of reasons including fishing for income and survival, proximity to ports, tourist resorts and a simple fact that most cities were historically built on the coastlines. Without an adequate warning system coastline populations are at the most risk as they would have little or no warning of the tsunami approaching. Coastlines are usually completely washed away, boats are destroyed and people may not have enough time to find higher ground. In Thailand, the sudden withdrawal of the sea was the only indication that a tsunami was coming whereas in Sri Lanka, the huge wave would have been the first thing they saw (Cummins and Leonard, 2005).
Tsunamis become disasters when they result in destruction of infrastructure and property in built-up areas, affecting the lives of the human population. Despite having a substantially lower number of casualties, the Tohoku disaster caused extensive damage. Large areas of coastline were completely washed away, villages were erased (Conder et al., 2012) and those homes that survived will face many issues, such as flooding and structural damage. Reconstruction estimates have been as much as $310 billion (BBC News, 2011). Likewise, the South Asia tsunami caused damage to roads, bridges, water and electricity supplies, destroying health centres and schools. For...