Natural barriers

Natural factors such as shoreline tree cover can mitigate tsunami effects. Some locations in the path of the 2004 Indian Ocean tsunami escaped almost unscathed because trees such as coconut palms and mangrove

Mangrove

Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...

s absorbed the tsunami's energy. In one striking example, the village of Naluvedapathy

Naluvedapathy

Naluvedapathy is a coastal village in the Indian state of Tamil Nadu. It is located in the Vedaranyam taluk of the Nagapattinam district. It sits on the mouth of the Addapar River...

 in India's Tamil Nadu

Tamil Nadu

Tamil Nadu is one of the 28 states of India. Its capital and largest city is Chennai. Tamil Nadu lies in the southernmost part of the Indian Peninsula and is bordered by the union territory of Pondicherry, and the states of Kerala, Karnataka, and Andhra Pradesh...

 region suffered only minimal damage and few deaths because the wave broke against a forest of 80,244 trees planted along the shoreline in 2002 in a bid to enter the Guinness Book of Records. Environmentalists have suggested tree planting along tsunami-prone seacoasts. Trees require years to grow to a useful size, but such plantations could offer a much cheaper and longer-lasting means of tsunami mitigation than artificial barriers.

A report published by the United Nations Environment Programme (UNEP) suggests that the tsunami of 26 December 2004 caused less damage in the areas where natural barriers were present, such as mangroves, coral reefs or coastal vegetation. A Japanese study of this tsunami in Sri Lanka used satellite imagery modelling to establish the parameters of coastal resistance as a function of different types of trees.
Natural barriers, such as coral reefs and mangrove forests, prevent the spread of tsunamis and the flow of coastal waters and mitigated the flood and surge of water.

Man-made barriers

Different designs of man-made tsunami barriers include building reefs and forests to above ground and submerged sea walls. In 2005, India began planting casurina and coconut

Coconut

The coconut palm, Cocos nucifera, is a member of the family Arecaceae . It is the only accepted species in the genus Cocos. The term coconut can refer to the entire coconut palm, the seed, or the fruit, which is not a botanical nut. The spelling cocoanut is an old-fashioned form of the word...

 saplings

Saplings

Although Saplings is generally regarded as one of Noel Streatfeild's novels for adults, published under her pseudonym Susan Scarlett, it is at least partially told from the perspective of four children - Laurel, Tony, Tuesday, and Kim, as well as from the perspective of their mother, Lena...

 on its coast as a natural barrier against future tsunami's like the 2004 Indian Ocean earthquake

2004 Indian Ocean earthquake

The 2004 Indian Ocean earthquake was an undersea megathrust earthquake that occurred at 00:58:53 UTC on Sunday, December 26, 2004, with an epicentre off the west coast of Sumatra, Indonesia. The quake itself is known by the scientific community as the Sumatra-Andaman earthquake...

. Studies have found that an offshore tsunami wall could reduce tsunami wave heights by up to 83%. Recent proposals of Tsunami walls have included dual barriers. The first barrier prevents a negative tsunami wave and the second barrier prevents a positive tsunami wave.