Mori Grant project Title: An investigation and comparative analysis of the impact of the 1923, 1960 and 2011 tsunamis on Kesennuma City, Miyagi Prefecture.
NB: The below paper was delivered at the 2011 Inter-University Seminar on Asian Megacities in Beijing, China. It is submitted here as a report on the work undertaken to date on the above Mori funded project.
Tsunami Impacts on Modern Cities: The Case of Kesennuma
On March 11th 2011 a 9.0 magnitude earthquake occurred 70km off the east coast of Japan. The tsunami it generated consisted of a number of large waves. The first wave reached Kesennuma in Miyagi prefecture 15-20 minutes after the earthquake. The height of the first wave was reported to be up to 10m high and easily breached the city’s 5m sea walls. The first and subsequent waves devastated areas of the city and have had a lasting impact on the lives of its inhabitants. This paper investigates the impact of the tsunami on the city of Kesennuma and the challenges modern cities face from tsunami disasters. In 2004 a similarly sized earthquake generated a devastating tsunami in the Indian Ocean. Areas affected were far less developed than Japan. Through comparison with the 2004 disaster Indian Ocean disaster, unique challenges faced by highly developed cities and universal impacts of tsunami disasters are discussed.
Keywords: 3.11 Tsunami, Kesennuma City, 2004 Indian Ocean Tsunami.
The coastline affected by the March 2011 tsunami is no stranger to devastating tsunamis. The flatlands along the Sanriku coast are particularly vulnerable. The historical record is a testament to this; in 869 a tsunami struck the Sanriku coast and killed 1000 people. The same area was hit in 1361 resulting in the destruction of 1700 houses. Again it was struck in 1896 with over 22,000 people losing their lives. In 1933 a further 3000 people were killed by tsunami waves in the region, with 9000 homes and 8000 boats also being destroyed. As of August 23rd 2011, the March 11th 2011 tsunami has taken the lives of 15,726 people with 4593 still missing.
The historical draw to the Sanriku coast of Japan comes from the opportunities it affords; namely food and commerce. Modern cities like Kesennuma are no different. It is located in Miyagi Prefecture, about fifty miles north of Sendai. Before the tsunami, it had a thriving economy based on its fishing industry. Its fish paste and shark’s fin were famed internationally and its notoriety was such that it brought in tourists. The impact of the tsunami has destroyed this economy and the modern way of life seems to have exacerbated rather than minimised some impacts of the disaster. This paper will investigate different ways in which the disaster affected the city of Kesennuma and, through comparison with the 2004 disaster, the challenges such disasters pose for modern cities.
Good communication infrastructure allowed Japan to implement a sophisticated early warning system. When the earthquake struck, tsunami warnings were quickly issued through a variety of different mediums. Television and radio broadcast the warning, the city’s twitter feed published updates on the incoming tsunami and 180 loud speakers in coastal areas broadcast the warning to all within earshot. The warning was a call to all to head inland to higher ground. The people of Kesennuma were familiar with such practices and knew where to assemble in the event of a disaster. Schools and community centres in areas of safety were where they headed. Undoubtedly the early warning system saved many lives. It was less than twenty minutes until the first wave hit Kesennuma. The death toll at Kesennuma currently stands at 1005 with 403 still missing (as of August 23rd 2011). This number would undoubtedly be higher without the early warning system that was in place. The fact that 19,900 people were evacuated from impacted areas in the days after the disaster hints at the warning systems effectiveness.
An additional point of note is that the tsunami damaged approximately 30% of the city’s 180 loud speakers. As a result emergency workers and those heading into areas that were affected by the tsunami are advised to carry radios with them at all times. This is in case a tsunami hits the coastline before the city is able to repair the damaged loud speakers. Locals have reported unease at the damage and a desire to have it repaired as soon as possible. Clearly the early warning system is not only an effective system to save lives; it is also a source of reassurance for residents. Fig. 1 shows the extent of the tsunamis encroachment inland. It is clear to see why such reassurance and a functioning early warning system is essential in a modern city like Kesennuma.
The benefit of a warning system like that at Kesennuma is clear to see when compared with the 2004 Indian Ocean tsunami. Areas affected by this disaster were not as heavily developed as the modern city of Kesennuma and, as a result, the devastation was absolute. For example, the tsunami wave took 100 minutes to reach Thailand, yet people were still on the shoreline when the wave struck, many took pictures or stood motionless as it approached. With such a large amount of time between the earthquake and the following tsunami, it is imagined thousands of lives could have been saved if an early warning system had been in place. The fact that, following the strong earthquake, the majority of people failed to realise the potential for a tsunami in 2004 points also to a lack of education about the potential for such a disaster.
The 2004 disaster was a wakeup call for countries like Thailand and Indonesia that in the wake of the disaster, stressed the need to install an early warning system and to educate or relocate those in vulnerable areas. Japan’s early warning system was a good model and the Thai government took note and installed loud speakers that would broadcast warnings in the event of a tsunami. Indeed this was essential to both protect its citizens and restore confidence in the tourism industry; with many foreign tourists refusing to go to areas affected by the 2004 tsunami until an early warning system was in place.
An early warning system is only as good as the level of education of the people it warns. Kesennuma is a good example of this; following the first wave, local people reported that some went back to vulnerable areas. As a result, they were in harm’s way when the second wave struck. The obliviousness to the possibility of further waves shows that further work needs to be done to educate people not just on what to do in the case of a tsunami but the basic science behind the tsunami itself. Furthermore, it was reported that, due to previous false alarms, some individuals ignored the warning completely.
As has been mentioned, Kesennuma is famed worldwide for the quality of its fish paste and shark’s fin. The tsunami had a devastating impact on this industry for a number of reasons. Firstly, the tsunami destroyed boats and processing equipment (fig. 2) related to this industry. Retreating waves also took with them a large amount of debris that contaminated coastal waters and also made navigation through these waters by boat difficult for several months following the disaster.
A unique factor in the 2011 tsunami was the Fukushima nuclear plant disaster. Modern cities require vast amounts of energy and, given Japan’s lack of fossil fuel resources; it has a reliance on nuclear power for almost 30% of its energy. The March 2011 tsunami badly damaged the Fukushima plant and, as a result, led to the contamination of coastal waters and areas surrounding the plant with radioactive material. Both the reality of coastal waters and marine life being contaminated and the stigma attached to the disaster have had a dramatic impact on the Kesennuma brand. Domestic and foreign buyers are rightly concerned about the health impacts of eating contaminated products and, given the Japanese government’s confused message on the fallout from the disaster, people are finding it difficult to trust these products and the word of the government.
In 2004, fishing communities were also devastated. For example, in areas affected in Sri Lanka 80% of fishing vessels were destroyed and the government noted that the disaster had pushed the fishing industry back to 1950 levels. However, without the added burden of serious contamination, recovery of the industry was likely far easier than it will be for Kesennuma and surrounding cities and towns. As has been noted, Kesennuma drew visitors from Japan and around the world due to its famed fish-based products. The loss of this industry is likely given the impact of the disaster. Tourism was key to areas struck by the 2004 tsunami and recovery was often contingent on developing mitigating strategies. The 2011 tsunami recovery seems contingent on the re-addressing of nuclear policy and safety. Local people of Kesennuma have come out as fiercely anti-nuclear following the disaster. This is hardly surprising given the impact it had on their industry. It has also led to local people starting to this seriously about renewable energy, with solar and wind power being cited as possible future energy sources for the city.
Roads and railways suffered considerable damage as a result of the tsunami. Indeed the JR station platform at Kesennuma station was completely swept away. Utilities were also affected following the tsunami with electricity and water supplies being temporarily suspended to areas of the city.
Areas closest to the coast in Kesennuma experienced the greatest damage. The force of the wave destroyed almost all buildings in its path; all that remained were concrete foundations. In many cases, buildings were swept off their foundations intact. Suggesting, though structurally sound, the sheer force of the wave was too much for their foundations. Building standards were much lower in areas impacted by the 2004 disaster. Coastal towns in Thailand and Indonesia both had a large number of low-rise timber framed buildings that were subject to significant damage and destruction. This type of building is extremely vulnerable and whole residential districts made up of such structures in Banda Aceh, Indonesia were wiped out. Non-engineered concrete, framed buildings were also prone to collapse. Engineered reinforced concrete framed buildings were able to withstand the tsunami forces; such buildings included hotels. This too was the case with a number of industrial and other reinforced concrete frames buildings in Kesennuma. Furthermore, some residential areas of Kesennuma experienced lower levels of flooding than at the coast, with the buildings were able to withstand this without severe structural damage. Without high building standards, something essential in modern cities, it is likely damage to these residential areas would have been greater.
The environmental impacts of a tsunami are often similar and the 2011 and 2004 disasters are no exception. These impacts included contamination of groundwater, damage to coastal forests, soil contamination, beach erosion and contamination of coastal waters with debris. Further contamination by chemicals and sewage was also reported in Kesennuma with the long term impact of such spillages uncertain. For example a local sewage treatment plant was destroyed. As a result, surrounding areas were contaminated and this continues to have an impact on air quality.
Modern cities require large amounts of space and facilities associated with industry. As a result, the natural environment is often altered to allow for such provision. In Kesennuma, this can be seen in the removal of areas of coastal forest. Buildings behind coastal forests in Kesennuma suffered significantly less damage than those not afforded such protection. Broken windows and collapsed walls were witnessed by buildings fronted by areas of forest, whereas buildings without such fronting were completely destroyed. Indeed broken trees along the coastline are noted to be facing the sea, presumably due to debris being pulled out to sea with the retreating waves. This suggests it may not have been the force of the wave that broke them. A similar protective quality of coastal forests was witnessed in 2004 with mangrove trees offering protection for buildings and communities behind them.
Fish processing facilities at Kesennuma are located on a peninsula, part of which was reclaimed from the sea for the purpose. The location of this land meant that the area was heavily impacted by the disaster. Such alteration of the natural coastline and the utilisation of such vulnerable land clearly exacerbated the destructiveness of the tsunami. Alteration of the coastline also added to the level of destruction in 2004. In this case it was the removal or alteration of sand dunes that exacerbated the tsunami’s impact. In order to improve scenic views and to allow further tourism related development, sand dunes were often removed or altered. In Sri Lanka a hotel that had a dune removed to improve scenic views was completely destroyed by the tsunami. A nearby hotel that was fronted by an unaltered dune received relatively little damage by comparison.
It is clear that the alteration of natural systems can exacerbate the impact of a tsunami event. The demands of modern cities often require such alterations. However, care should be taken to evaluate the potential negative impacts of such decisions.
Rivers exacerbated the impact of the tsunami in Kesennuma, as is clear from studying the tsunami extents (fig. 1). The rivers effectively channeled the tsunami and it reached further inland where it was afforded a river route. This was also the case when the 2004 tsunami struck.
The most obvious way to protect against large waves is the building of a sea wall. At Kesennuma, the sea wall was less than five metres high. With locals reporting wave heights approaching ten metres, it is clear such measures were inadequate. Indeed, the national government of Japan has conceded that preventing a tsunami disaster of this scale is impossible. The focus, therefore, should be on mitigation. Such initial proposals include the raising of transport infrastructure such as roads and railway lines and the installation of walls along river banks. Additional planned future measures include further education and the creation of a country-wide hazard map.
Town planning is important, especially in areas susceptible to natural disasters such as tsunamis. In Kesennuma, schools and other key buildings are already located on higher ground and act as refuges when disasters strike. Such planning was taken up by Thailand and other affected countries following the 2004 disaster. The damage witnessed to areas of Kesennuma was also a wake-up call. There is a fear that a future disaster could be even more devastating, particularly to residential areas. This fear is not unfounded; fig. 5 shows the degree of devastation caused to areas of Kesennuma. As a result there are proposals to move vulnerable residential areas further inland to higher ground, with the local and prefectural authorities yet to make a final decision. The reason for their current location is proximity to the port and coastline as many residents are involved in the fishing industry. However, consulted residents are willing to accept such relocation in the interests of safety. Furthermore, such disaster events are extremely costly and taking preventative action now may save such cities considerable funds in the long term.
Following the 2004 disaster, the Thai government offered relocation packages to those living in areas impacted by the tsunami. It was reported that many people were reluctant to take these packages and built temporary structures in their old communities as opposed to relocating. There is a similar community spirit in Kesennuma. There is a strong sense of resilience and desire to rebuild rather than relocate. Due to frustration with the inaction of the national government, local people started the reconstruction process themselves. This reconstruction included the opening of a small fish market and the marketing of the Kesennuma port as open for business soon after the disaster. None of the locals talked to by students of Keio University expressed a desire to leave Kesennuma.
It is clear to see that a natural disaster of the scale witnessed by Japan in March 2011 has devastating consequences. It is impossible for a modern city to completely protect itself against such a disaster. Kesennuma is a good example of how a tsunami can affect a modern city. It shows the importance of good communication and an effective early warning system. The city of Kesennuma and Japan as a whole are far more developed than those areas impacted by the 2004 tsunami. Japan’s geography, environment and vegetation are again very different. However, many similarities can be drawn between these two tsunami events and the impact they had on local communities.
The differences between Japan and other nations highlight the danger posed by such extreme natural disasters to other developed nations. Japan had protective sea walls in place, the best early warning system in the world and a well-educated public. However, the scale of the disaster showed all these measures to be, to differing degrees, inadequate. Indeed the Fukushima disaster and swamping of protective sea walls shows the frailty of such protective measures. Furthermore casualties and deaths show that further work needs to be done in preparation for any future disaster.
What is also clear is that had countries such as Thailand been afforded the same warning systems as Kesennuma many lives could have been saved. With less than 20 minutes until the first wave, people were able to get to safety. People on the southern coast of Thailand had 100 minutes to get to safety but were not afforded the same sophisticated early warning system and sadly most perished.
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