On Boxing Day 2004 the biggest tsunami in living memory ravaged the countries that surround the Indian Ocean. Sri Lanka was one of the countries hit hardest by the tragedy. Once a developing holiday paradise, it was ripped apart by the giant waves that took more than 31,000 lives and left half-a-million people homeless.

The harrowing TV coverage of the disaster at the beginning of this year can prepare you for what you see there, but the pictures don't give any indication of the scale of devastation.

The reality is that mile upon mile of wreckage and other visible reminders of the aftermath remain. The coastline is littered with houses reduced to rubble, and dotted by emergency camps filled with thousands of homeless people.

But it's not all despair in Sri Lanka. There is hope, and it's thanks to your help in contributing more than 330,000 to Unichef that the country has not suffered more. Despite the challenges that face them, I saw hope in the eyes of children who had lost brothers, sisters, mothers and fathers. As they sat in crowded classrooms with Unicef-branded schoolbooks, the smiles on their faces said it all - they were clearly grateful that their lives were returning to some sort of normality.

The immediate post-tsunami period saw an enormous relief effort, which was hugely successful: no more children died, and 85% of 200,000 displaced children were back at school by the end of January, within a month of the disaster. These successes were thanks to phenomenal efforts within the country by non-government organisations (NGOs) such as Unicef and huge numbers of Sri Lankan volunteers.

Unicef moved quickly to set up temporary schools for the 200,000 children who had attended the 184 schools that were destroyed. The temporary schools were also used as bases to track the large number of people who had been displaced.

Geoff Keele, communications officer for Unicef in Sri Lanka, explained to me how the aid agency provided clean water, set up temporary camps, cleaned wells, provided latrines and gave advice on health and nutrition during the emergency relief effort.

Much of the work since then has been devoted to schools and children, providing support and psychosocial counselling as well as exercise books, uniforms, desks, chairs and 200 temporary school shelters, so the kids can continue learning while their schools are being rebuilt.

"We changed our focus from back-to-school to back-to-learning, as you can learn under a tree - it doesn't need to be bricks and mortar," says Keele.

Thanks in part to your generosity and efforts through fundraising initiatives such as Unichef, most Sri Lankan children now have the support of a school and a place to learn. Scant consolation for those who have lost family, friends and all their possessions, but it is something.

Unicef, with its 30 years of experience in the country, was well placed to organise NGO activity in education, health protection and sanitation, but inevitably some mistakes were made. Ibra Hameed, head of Unicef's zonal office in the city of Galle, concedes that co-ordinating the huge number of aid agencies in post-tsunami Sri Lanka was a major challenge. He says: "There were things that were done that were culturally unacceptable, like some open-pit latrines were built - Sri Lankan people won't use these, so they were a waste of money."

According to Keele, the situation has become even tougher now. "Currently, we are in a difficult middle period," he says. "We haven't quite managed to bridge into long-term relief yet, and the political problems are starting to rear their heads again."

He goes on: "I don't think it is a permanent problem, just a bump in the road to recovery while the government agencies define their roles. It's going to take a good three years to rebuild these houses. In the meantime, we have to work out how organisations such as Unicef can fill in the gaps between the various government agencies in charge of the rebuilding effort."

There's no denying that there are causes for concern, the most worrying being the Sri Lankan government's ponderously slow progress in housing the half-a-million homeless. The most optimistic estimates predict that it will take three years to rehouse all the families who lost their homes; the worst forecasts say it will take a decade.

Part of the problem is that the Sri Lankan government has imposed a 100m-wide exclusion zone along the coast, within which it forbids the rebuilding of properties that are less than 40% intact. This has slowed progress so much that, when we visited, of the 80,000 permanent houses needed, only 200 had been built. A further 2,000 temporary shelters have been built to move people from tents into more comfortable buildings, but this is only a stopgap.

Keele says the government's policy has meant identifying new areas of land where houses and services can be provided - not an easy task in a densely populated country (19 million people are crammed into an island the size of Ireland).

Hameed agrees. "In places like Galle, there's not enough land for permanent housing, and the policy is confusing," he says. "Businesses and homes that were partially destroyed can be rebuilt within the 100m zone, but if [a building] was totally destroyed, then it can't be."

It's clear, when you visit the emergency camps, that having a livelihood and a home are the two main concerns of those living in the squalid and fearsomely hot tents. We visited a camp just outside Galle, consisting of 60 blue tents and 10 temporary wooden huts with tin roofs, housing 347 people. Aid workers have christened the tents "microwaves" because they're so hot inside. But a bigger threat is the imminent monsoon season that could turn the baked ground into a quagmire.

We were invited into 42-year-old Seetha's 10sq ft tent, which she shares with her husband and four teenage children. She breaks down in tears as she explains that she had been promised a transitional wooden hut nearby, but the village head had decided her family couldn't have one as they were living in rented accommodation before the disaster. This is a common story. Anyone renting accommodation will not get a new house.

Further down the line of tents, another woman is cooking a traditional Sri Lankan potato curry for her grandchildren on an improvised stove made of three bricks above a small fire. The children's mother is abroad, earning money to send to the family. While they're grateful for the aid that has helped them survive, they are visibly frustrated at the delay in getting a house and putting their lives back on track.

On the morning the tsunami struck, the village children in nearby Dissanayake were playing in the surf that overlooks the stunning bay of Weligama. Suddenly the sea was sucked out of the bay and the children followed it, with no idea of the tragedy about to unfold.
One boy, 16-year-old Chathura Weerathunga, tells me of his experience. "I was watching Sri Lanka play New Zealand in a cricket test match on TV when I heard a loud noise from the sea," he says. "Me and my mother rushed outside, only to see several people running away from the sea. Before we knew it, the tide was crossing the road and we were floating in the sea."

Chathura and his mother managed to grab a steel post about 15ft above the ground and hold on. Minutes later, a little girl floated past them. His mother grabbed her and, five minutes later, once the tide began to subside, Chathura clambered on to a roof and rescued the little girl from his mother's arms.

"I pulled the little girl up, but my mum was too heavy," he says. "Thankfully, someone else was there to help me haul her on to the roof."
His father, a local hotelier and businessman, was washed away. His hotel was destroyed, along with the family's home and possessions. There was no insurance to cover a natural disaster, so the family are left fatherless and penniless. What he wants most now, he says, is a home for him and his mother, and the chance to attend a Buddhist school in Galle to learn better English.

These are just a few of the countless distressing stories you hear as you travel around the devastated southern and eastern coastline of Sri Lanka. But, while many are disconsolate, there is also evidence that some people's lives are getting back on track. Chathura, for instance, is determined that the tsunami is not going to ruin the rest of his life, even though his mother's house was within 100m of the sea and cannot be rebuilt. At the moment they are living in a former Dissanayake medical hostel along with other survivors from the village's 56 houses that were washed away.

As we arrive, the camp's adults are making colourful paper lanterns and bright streamers for the Buddhist holiday of Vasek. Unicef support workers have been encouraging the adults and children to celebrate the two-day festival in the traditional way, to try to get their shattered lives back to normal.

Chathura welcomes us. "We thank you for coming to see us today and we hope you enjoy the show," he says. "We lost 36 children to the tsunami. We were very happy before, but now we feel helpless." Another boy, 15-year-old Dinesh, performs traditional Kandian dances as his father watches. Dinesh lost his mother in the tsunami, and later tried to commit suicide with an overdose of paracetamol.

Janaka Wickramasinghe - one of 150 newly qualified Sri Lankan doctors who have become Unicef support workers - tells me that Dinesh's health is still fragile but, with help and support, he has come out of depression. He now leads the camp's Little Children Society and teaches the other kids in the camp to dance. "I want to make my mother proud," says Dinesh.

Wickramasinghe says teenage children were hard to assess following the tsunami. "They're old enough to express their emotions, but too often they would just say they're OK," he says. "We had to get them to express their feelings to know how they are coping." The younger kids, however, often cannot express themselves, so it was equally hard to gauge their suffering.

"When I started working in a nearby camp, many of the children were mute and not taking part in any activities, so we asked them to draw pictures," says Wickramasinghe. "For the first few weeks, all they drew were dark, sad pictures of the tsunami, but gradually, after a few months, they were drawing kites and flowers and happier pictures."

Support such as this has been vital in helping the children to cope with the dreadful trauma. And it's thanks to fundraising efforts such as Unichef's that work like this has helped many Sri Lankan children cope with the horror they witnessed.

What the money was spent on - the initial response

In the immediate aftermath of the tsunami, Philip Howard, chef-proprietor of London's two-Michelli-starred retaurant the Square, dreamed up a frundraising initiative.

He teamed up with Caterer , restaurant guide and website Square Meal, and Unicef, the United Nations charity for children, to hatch a fundraising effort that became known as Unichef.

Howard's plan was for restaurants, including those in pubs and hotels, to sign up to the campaign and donate a percentage of their takings on 7 February to Unicef. More than 200 restaurants, group restaurants, hotels, pubs, contract caterers ane even a tearoom on the Isle of Arran signed up, raising more than £330,000.

Within 10 weeks of the tsunami, Unichef had received $442m (£253m) globally and had spent $70m (£40m) of this within three months. Of the total Unicef tsunami effort, 32% of the money will support work in Sri Lanka.

Within 72 hours of the disaster, the charity had begun to dispatch emergency health kits for 150,000 people. Since then it has distributed:

• 16 water trucks, 285 water tanks, 100,000 bottles of water, 50 tonnes of water treatment chemicals and 25,000 water purification tablets.
• 100,000 bars of soap and 5,000 buckets.
• Six gully emptiers and 60 pumps to help clean sanitiation and water supplies.
• 500 tents and 9,500 tarpaulins for temporary shelters.
• 1,000 temporary toilets have been built in camps, schools and home communities.
• About 16,000 kits with hygiene products, including basics such as soap and towels, and sanitary napkins, along with 200,000 leaflets on personal hygiene.
• 75,000 mosquito nets, 90 infant scales, 30 delivery beds, 150,000 sachets of oral rehydration salts, antibiotics and antiseptics.

Getting children back to school

Unicef wa sthe Sri Lankan governmant's principal partner in a nationwide campaign to get children back to school within a month. It distributed:

• 3,100 emergency "school in a box" kits, containing notebooks, pens and pencils for was many as 200,000 children.
• 107,000 school uniforms, 45,000 desks and tables, 45,000 chairs, 114,000 school bags, thousands of text books
• 1,350 recreational kits, including team sports and play equipment for as many as 81,000 children
• More supplies are still being distributed to fill any gaps

Next week we look at how fishermen are keen to get back to the sea, and how the Sri Lankan tourism industry is trying to get itself back on the map.