The earthquake has hit local tourism operators hard but with global media focused on the devastation there is concern the tragic reality of one city centre could become the perception of an entire country.

And the economic stakes are high.

International tourists spent $9.5 billion here during the year ended last March - equivalent to 18.2 per cent of all export earnings.

Politicians, industry bodies and celebrities have been urging tourists to keep coming, with a message that New Zealand is open for business.

But inevitably cancellations are coming.

The Ministry of Economic Development has started work on calculating an economic impact already being felt by tourism operators close to the epicentre.

Michael Esposito is managing director of The Wood Scenic Line, which owns the Christchurch Tramway, Gondola and Punting on the Avon attractions - all of which face long closures.

The tram will be out of action for six to 18 months, the gondola for three to 12 months and the punting probably three months, Esposito says.

"Some of the tracks have snapped, others have raised up a bit, the overhead power cables and poles have come down in some places," he says.

Esposito has had a quick look at the base and top stations of the gondola.

"The top station, one of the water pipes burst so there's water seeping between the floors. Structurally it's not too bad.

"Similarly with the base station but we are still waiting on a structural engineer to have a look at it all. But of course they're all pretty busy with more important things at the moment."

Esposito has heard 40 or 50 per cent of accommodation in town has gone.

"That's half your tourist numbers already so I would expect tourist numbers over the next 12 months to be, on a good day, quarter of what they were."

Everyone has different thoughts on how long the impact will last.

"I thought maybe five years to get up to where we are today. Some other people are more optimistic, maybe three to four years."

Tourism operators were helping each other but the mood was sombre, with the prospect of scaled back operations and redundancies.

"If the reduction in visitor numbers is as severe as everyone expects it'll be very hard for some to survive," Esposito says.

Christchurch and Canterbury Tourism chief executive Tim Hunter says a survey of commercial accommodation shows 6343 beds are in use out of 13,653 before the earthquake - equivalent to 46 per cent.

"It's going to rise gradually every day, but it just will depend on how far in they take the cordon," Hunter says.

"We're just going to have to be patient, they will become available ... but these numbers are very large in terms of what they've taken away so they're going to have quite a sizeable impact on our tourism flows in the next 12 months particularly."

Kiwi expatriate Phil Keoghan, presenter of television's The Amazing Race, was back in his hometown, Christchurch, after the earthquake.

In an interview with CBS's The Early Show, Keoghan made an impassioned plea for United States tourists to keep coming.

"To be honest with you, the best thing that people can do is come to New Zealand," Keoghan said.

"Now that sounds crazy but this damage is isolated to a very, very small part of New Zealand - an area the size of lower Manhattan," he said.

Tourism was crucial to the country.

"We just can't afford a second hit if people stop coming to this country."

The rest of the country was open for business, Keoghan told the programme.

"So if people want to help out - don't cancel your trip to New Zealand."

Inbound Tour Operators Council president Brian Henderson says some images of Christchurch would have to be taken out of the branding.

"Some care has to be taken over it but, by the same token, Canterbury in general still has a lot of activities and we still want people going out to Akaroa and Hanmer and these places too still really need tourism."

The key thing was making sure the Government supported Tourism New Zealand in marketing the country in Australia and the rest of the world, Henderson says.

"If we pull back from that messaging now, well, it won't be good, I don't think."

Tourism New Zealand chief executive Kevin Bowler says marketing efforts internationally were adjusted immediately after the earthquake.

"We are already working with our tourism partners to begin to consider what the next phase of the tourism response will to be, but to do that we need a [fuller] stocktake of the reality of the local impact on our tourism offer as well.

"Some short-term fall-off in total visitor numbers is inevitable, and we do know that Christchurch city needs to take the time to rebuild and repair before encouraging people to visit, but the word is out there that New Zealand's doors are open."

Air New Zealand deputy chief executive Norm Thompson says the only market at this stage to show some signs of cancellation is Japan.

"The good news is the changes that we're seeing coming out of Japan are only within the next four to six weeks," Thompson says.

The UK market has good knowledge of New Zealand, while in the US most of the business came from about 12 wholesalers, he says.

"We are not even contemplating at this stage adjusting schedules or capacity as a result of the quake."

Christchurch Airport - the entry point for about 90 per cent of overseas visitors to the South Island - is fully operational.

"We're working very closely with the industry ... Kevin Bowler and myself are talking along the lines of what further marketing activity we can jointly put into the market to keep the overseas market stimulated to still come to New Zealand - we've still got to keep promoting the country," Thompson says.

"I'm sure by us all working together we can continue to see good tourism numbers coming in, particularly from our key markets."

James Bickford, managing director of New Zealand for global branding agency Interbrand, says there is a danger that when the television cameras move on people are left with a tragedy in their minds.

"We don't have the money to go and do a big ad campaign to say New Zealand's open ... we need to use this opportunity through the media and the story to get that brand message out."

A million Kiwis lived overseas and "in this case it's the people of our nation who are around the world who have to reinforce their brand, their country ... that those people back home are just going to rebuild this better, bigger and more inspirational than ever before, which is going to make New Zealand an even better place to be visiting in the future."

It is an opportunity to regalvanise expat Kiwis, who will be looking at their homeland and might feel detached and lonely.

"Maybe you feel you can't contribute outside of financially, but actually you can contribute in a huge way right now and that's to spread this word."

Other issues were developing in the world, such as the revolution in Libya.

"My concern is that when those people switch TV channels the last image they have of New Zealand is rubble and tragedy and it may be a window that will close quite quickly."

San Francisco suffered its own tragic earthquake in 1989 and probably came through stronger as a destination, Bickford says.

"I think that one of the great things we can learn from the Americans is that there's always an upside and they're not afraid to talk about it," he says.

Professor Rod Brodie, head of the department of marketing at the University of Auckland Business School, says a lot of communication now is through social media.

"Quite often with that it is not the commercially posted information, it is the stories that get the attention in social media," Brodie says.

"People probably in the short term won't want to go to Christchurch as much but that could change because there are still a lot of very positive things about Christchurch."

Some colleagues overseas had commented to Brodie on the resilience of the community as well as the tragedy.

"There is a positive side to it as well as a negative side," he says.

While Christchurch's important tourism industry would suffer in the short term, the stories of the city's determination to recover from the trauma of the past six months could one day be woven into its heritage to make tourism even stronger, Brodie says.

"Human drama is a very powerful and rich way to tell stories, and we have seen earthquake-stricken cities like San Francisco and Kobe recover and flourish after terrible tragedies."

The Rugby World Cup was a golden opportunity.

"Wouldn't it be wonderful if Christchurch was resilient enough and there were enough initiatives so the whole world cup programme wasn't disrupted.

"Even though things have been absolutely disastrous, people are resilient in coming back and the rebirth will take place."