Impact: Indonesia sustained the worst human losses and physical damage in the tsunami and earthquake of 26 December, 2004. The western tip of the island of Sumatra - the closest inhabited area to the earthquake's epicentre - was devastated. Some coastal villages are thought to have lost more than 70% of inhabitants. Much of the fishing and agricultural sectors in Aceh province was heavily damaged and 44% of people lost their livelihoods, according to the Asian Development Bank.
Toll: More than 130,000 people died, while at least 37,000 others remain missing. The exact number of victims will probably never be known. About 500,000 people were made homeless.
Aid: After the tsunami more than 160 aid organisations and UN agencies began operations in Indonesia to provide food, shelter and schooling. Foreign troops were also involved in initial emergency relief efforts. Agencies estimate a humanitarian response may be needed for up to two years.
One year on, Aceh's provincial capital, Banda Aceh, has been completely rebuilt, but there are still areas not far away which remain deserted wasteland. More than 60,000 survivors are still living in tents.
The UNDP says construction spending will soon reach approximately $2bn (£1.7bn) a year from current levels of $50m (£42m).
Impact: After Indonesia, Sri Lanka suffered more from the tsunami than anywhere else. Its southern and eastern coastlines were ravaged. More than 100,000 homes were damaged or destroyed, along with crops and fishing boats. The International Labour Organization estimates more than 400,000 people lost their jobs as a result - mostly in the fishing, hotel and tourism sectors.
Toll: More than 31,000 people died and more than 4,000 have been reported missing. More than half a million people were made homeless. In one of the worst incidents, more than 800 people died when a train was struck by the tsunami at Telwatta, in the south-west.
Aid: Nearly $3bn was pledged by international donors. But much of the aid has not been delivered because the government and Tamil Tiger rebels spent months wrangling over how to distribute it. When a deal was finally signed, it was promptly suspended by the Supreme Court which questioned some of its provisions. In the recent presidential election, voters frequently complained of delays in getting help. The problems are worse in Tamil Tiger-controlled areas.
INDIA'S SOUTH-EAST COAST
Impact: India's south-east coast was the worst affected part of the mainland when the tsunami struck and penetrated up to 3km inland. More than 150,000 homes were damaged or destroyed in Tamil Nadu, Andhra Pradesh and Kerala states, and in Pondicherry. (See below for more details on the Andaman and Nicobar islands.) More than 600km of roads and 14 bridges were damaged, according to the Asian Development Bank.
Toll: On the mainland, 8,850 people are confirmed dead - 7,983 of them in Tamil Nadu. (See below for data on the Andaman and Nicobar islands). It is estimated that almost 70,000 people are in relief camps or centres on the mainland.
Aid: Repairing the damage was expected to cost about $1.2bn. India has provided aid to other countries hit by the tsunami. Initially it refused outside help itself. Donations of fibreglass boats to some fishing communities have helped revive their livelihoods. Also, with the high demands for boats and catamarans, many fishermen have taken up boat-making as a part-time occupation. Aid agencies say the rehabilitation efforts in the state are generally positive. But thousands are still living in uncomfortable pre-fabricated tin shelters and do not have permanent homes. Government rules that new homes must be built at least 500 metres away from the sea have made fishing communities unhappy. Another major concern is the agricultural community which lost 5,000 hectares of farming land to the tsunami.
INDIA'S ANDAMAN AND NICOBAR ISLANDS
Impact: The remote islands, lying about 1,400 km from the mainland but only 100km or so from the epicentre, suffered extensive destruction. Salt water contaminated many sources of fresh water and destroyed large tracts of arable land. Many jetties - vital for getting supplies into the islands - were destroyed.
Toll: Almost 1,900 islanders were confirmed dead from a population of some 400,000. More than 5,550 are still missing - the bulk of them from Katchall island.
Aid: India refused international assistance to the strategically important Andamans where it has sensitivities over its military base. There have also been concerns that poorly planned reconstruction work would damage the lives of various tribal groups there. Local people and NGOs say money has not been spent well, and there have been accusations of contractors profiteering. More than 10,000 people are still living in pre-fabricated tin shelters ill-suited to the climate and their requests for tools and wood to build their own shelters has been ignored by the government. Some people were given 10,000 rupees ($232) to replace their fishing boats, but complain that the boats cost 10 times more than that.
Impact: The west coast of Thailand was severely hit, including outlying islands and tourist resorts near Phuket.
Toll: Some 5,395 people have been confirmed dead. They include about 2,400 foreigners from 36 countries. The number of people still missing exceeds 2,800. Some bodies may still lie in the rubble of wrecked hotels and their environs.
Aid: Thailand did not ask for disaster relief aid, but it has requested technical help to identify the dead - a vast task that is still continuing.
However, more than 3,500 volunteers from more than 50 countries have volunteered their services to help Thailand recover over the last year.
Rebuilding has been rapid along Thailand's west coast, which is heavily dependent on tourism.
The UN has praised the Thai government's response, but notes that rampant tourism development is once again in evidence, and that other issues such as land disputes still need to be resolved.
Its report, a year on from the tsunami, finds that the fishing industry suffered far heavier losses than the tourism industry - about $267.8m (£226.3m).
The Thai government has provided more than $1bn in aid, while international aid has totalled $69m (£58.3m).
Impact: The extremely low-lying Maldives consist of 199 inhabited islands, 20 of which were described as "totally destroyed" by the tsunami. Well over 4,000 homes were destroyed or damaged. Schools, boats, infrastructure and tourist resorts also suffered.
Toll: At least 81 people died. The impact on the country's economy was huge.
Aid: The Maldives government puts rebuilding costs for homes and infrastructure at about $375m - but so far sums pledged fall well short of this.
Impact: Shielded by Sumatra, Malaysia's coastline was spared widespread devastation despite being close to the epicentre. Fewer than 10,000 people are believed to have been affected, although scores were swept from beaches near the northern island of Penang.
Toll: At least 68 people confirmed dead.
Impact: The worst affected area was the Irrawaddy Delta, inhabited by poor subsistence farmers and fishing families.
Toll: Burma's military junta puts the death toll at 61, but the World Food Programme (WFP) says this may be an underestimate. One WFP employee found 200 households where at least one person was missing. Hundreds of Burmese migrants workers living in Thailand are also thought to have died.
Toll: Two people were reported dead in Bangladesh.
Impact: Somalia was the worst-hit African state. Damage was concentrated in the Puntland region, on the tip of the Horn of Africa. Water destroyed 1,180 homes, smashed 2,400 boats and rendered freshwater wells and reservoirs unusable, the UN said in a report early in January.
Toll: Between 150 and 200 Somalis are thought to have died, with thousands more homeless and many fishermen unaccounted for. As many as 30,000 people may have been displaced.
Aid: The UN has called for $13m to help tsunami victims. Aid agencies with small ground operations in Puntland delivered food and relief supplies, as did a German Navy helicopter.
Toll: One person drowned in Kenya.
Toll: Ten people were killed in Tanzania.
Toll: One person was killed in the Seychelles.