Whenever we heard the name of earthquakes and tsunamis
we remind Japan since it is well know that Japan
is very much expose to earthquakes and tsunamis.
However Japan has taken many successful mitigation measures where they have reduced the impact of earthquakes and specially the impact of tsunamis. Sri Lanka was exposed to a giant tsunami in 2004 and it is considered as the biggest natural disaster Sri Lanka faced in the recent history and Japan would be an ideal country for Sri Lanka to study what measures they have taken to prevent or reduce the impact of tsunamis.
Since Sri Lanka is surrounded by sea, Sri Lanka is exposed fully to tsunamis but the frequency is less compared to Japan. However the severity of the tsunamis that reaches to Sri Lankan may be high since many of the tsunamis are distance tsunamis. One important fact that has to be considered when adopting Japan Tsunami Mitigation measures is that Japan is located in a tsunami prone area but Sri Lanka is not. Another fact is that Japan is mostly affected by local tsunamis where Sri Lanka is affected by distance tsunamis.
Japan has taken Integrated Tsunami Mitigation Strategies where they are consisting of Structural and Non-Structural measures.
In Japan it is easy to find tsunami walls in many beaches built in the purpose of reducing the tsunami risk. These walls are many meters wide and also in some areas they are few kilometers in length. Tsunami walls are good for the areas in Sri Lanka which have identified as high level of vulnerability due to tsunami. But this has not necessary to be built in concrete like in Japan since Sri Lanka is not frequently exposed to tsunamis. Rock walls or soil walls are the ideal for Sri Lankan scenario.
River gates are built in most or the rivers in Japan to reduce the impact of tsunami since rivers and other water bodies connected to sea acts as a channel for the tsunami to migrate in land. But considering the cost of building river gates, maintenance, impact for the appearance to the natural environment around, the location of Sri Lanka(not in a tsunami prone area) it is not necessary to build river gates in Sri Lanka.
Tsunami forests also acts as a barrier to tsunamis and it can be practiced in Sri Lanka also since it is a natural way of making a barrier. Depending on the vulnerable of an area it can be decided the width of the forest and also the length.
Tsunami break waters
Break waters protect the harbors specially reducing the impact of tsunamis to harbors. This method is advisable to adapt to Sri Lanka also. Not only for harbors, but also for other areas which are identified as high vulnerable areas can implement this strategy.
At any emergency situation early warnings are important. Sri Lanka also should practice this and in coastal areas people are well educated on how to behave at a time given of tsunami alerts.
Displaying tsunami water level height
Japan displays tsunami water level heights of previous tsunamis in many locations so people around can get an idea in case of tsunami how vulnerable they are. Even in Sri Lanka this can be practiced since the cost of implementing this is not much greater and at a time that tsunami alerts are given people are aware of the possible areas that tsunami can strike. In this manner the water level of 2004 tsunami is the only indicator that Sri Lanka has.
Evacuation centers can be built in vulnerable areas. These places are used not only as evacuation centers. The main purpose is to make an evacuation center and it is facilitated with all the necessary things to face a tsunami situation. But it can be used for any other purpose in day to day life. This method should adapt to Sri Lanka also. On the other way these centers reminds people that tsunamis can strike Sri Lanka as well.
Signs to display the maps and paths of evacuation centers
Even in Sri Lanka, it has take actions to display signs on the evacuation centers. Moreover the paths of evacuating are also very much important. Otherwise at a situation of tsunami those who does not have any idea of evacuation centers or the direction they are moving may lead them towards the tsunami.
In Japan there are many boards displayed mentioning “Ground shaking slow Tsunami can be generated”, “With earthquake comes tsunami”. But these are not necessary for Sri Lanka since Sri Lanka is not in a tsunami prone area like Japan and every earthquake that felt by Sri Lanka does not create a tsunami. Even though a tsunami is generated, as of the location of Sri Lanka in the Indian Ocean it can raise a timely early warning. However, another important sign board can be found in Japan which says “Life is more important than money”. Displaying boards with this meaning is advised to Sri Lanka since people may try to gather their belongings at a tsunami alert since they don’t have any idea of the severity as Sri Lanka does not frequently face tsunamis.
In Japan many areas have memorial plaques in order to remember people that the frequency of tsunamis is high. But in Sri Lanka since the frequency of tsunamis is not that much high like in Japan this method is not advisable.
Hazard mapping is done in Japan so everybody can identify the areas that are possible to flood due to tsunamis. This is important to Sri Lanka also not only in short term manners but also in long term manner. Vulnerable areas can be identified and it can include tsunami mitigation measures in the development programs undertaken in the vulnerable areas.
Educating school children
Japan always tries to educate school children since the education is very much important to face tsunami hazards. This method should take in to action in Sri Lanka as well specially in coastal areas. School children can teach how to behave in tsunami situation and they can help to guide their parents and other family members. It’s a very good method to spread the knowledge.
Mentioning the height of the floor in building
In the buildings in the coastal area it can be displayed the height on the floor so people know at what height they are standing. This is not a costly method and also at a tsunami alert it gives the clear idea to people whether they should move to an evacuating center or whether they are safe on where they are.
Reserving one floor of tall buildings as an gathering floor
In Japan one floor of taller building are reserves as a gathering floor so at a time of tsunami people can evacuate to that. This measure is not necessary to Sri Lanka due to two main reasons. One is that Sri Lanka is not in a tsunami prone area like Japan. The other thing is most of the tsunamis strike Sri Lanka are distance tsunamis so it can raise timely early warnings.
What ever the frequency that tsunamis can happen, preparedness is important. Tsunami drills promote the impact that tsunamis can impose and also it teach people on how to behave at tsunami situations. This is important and should practice in Sri Lanka at least once a year in coastal areas.