www.guardian.co.uk American scientists are preparing a makeover for the world's most famous graveyard. A plan to control tourism, limit traffic, deflect flash floods, reduce theft and vandalism and even alter farming on the banks of the Nile could soon begin to change the face of the Valley of the Kings.

Egypt's Supreme Council of Antiquities has asked the archaeologists, architects and engineers of the Theban Mapping Project - launched 25 years ago simply to make a detailed map of the 62 tombs and temples of the pharaohs and nobles buried more than 3,000 years ago - to complete a plan for the conservation of the valley by the end of 2005.

Kent Weeks, professor of Egyptology at the American University in Cairo, and one of the leading researchers in the region, told a London conference organised by the Bloomsbury Academy on Saturday that visits by 9,000 tourists every day were beginning to destroy the paintings and fabric of tombs that once housed Ramses II, Seti I and Tutankhamun.

"The results are an uncomfortable, claustrophobic experience for tourists, who go away sweating, unhappy, feeling that they have been robbed in a way, which they have, and we find the tomb is suffering badly," he said.

The tombs must be lit by hundreds of 40 watt bulbs, steadily raising the temperature in what were once sacred subterranean corridors dark for 30 centuries. Four hundred or more tourists a day each leave behind an ounce of moisture - about a third of a teacup - from their breath in any one tomb.

"The rapid, dramatic fluctuation in temperature and humidity are the two things that will do the greatest damage in the shortest time," said Professor Weeks. "It's

partly because the plaster itself, when it comes in contact with moisture, begins to soften, gradually weakens and can no longer support itself on a vertical wall, and falls of its own weight to the floor, dragging with it the pigments that were applied. Eventually you wind up with bare stone and a puddle of pigments and mud on the floor, and that's it."

Prof Weeks began the Theban mapping project in 1979. A project originally expected to take only a few seasons took 21 years.

During the research, he made one of the most dramatic discoveries of the last century. He began examining an old, seemingly unimportant tomb, a "hole in the ground" about to be threatened by a tourist coach park, and identified KV5, the tomb of the sons of Ramses II, the pharaoh linked to the biblical story of Moses. Prof Weeks has so far identified 130 corridors and chambers, and expects to eventually find perhaps 200. KV5 is the biggest tomb in the valley, and one of the biggest in the world.

But the Valley of the Kings is now one of the world's greatest tourist sites, and Egypt expects visitor numbers overall to rise in the next decade to 14 million a year. Many of these will visit Thebes and Luxor, on the Nile several hundred miles south of Cairo. Prof Weeks and his Egyptian colleagues plan to test new technology based on "cold" light-emitting diodes to light up the huge tombs, and to introduce "timed" tickets to limit the number of visitors in any tomb.

The Japanese government is to finance a more discreetly designed visitor centre, and engineers could move parking lots, tear up the valley's Tarmac roads and instead spray polymer on the sand, gravel and limestone bedrock, to provide a long-lasting surface that would mimic the look of ancient desert roads. The scientists have also been asked to begin a plan to protect the 40 or so mortuary temples beyond the valley, at the edge of the cultivated region of Thebes.

"Of those 40 odd temples, only four can be said to be in relatively good condition. The other 36 are on the verge of annihilation; extinction from the incursions of buildings, roads, agricultural land, rising groundwater, theft and vandalism and from the fact that in some cases so little of them remains - they have been used as quarries for the last several centuries - that people don't realise they are there," he said.

Ancient Egyptian builders often raised huge monuments on puzzlingly flimsy foundations. Vast statues and temples that for thousands of year survived the annual Nile floods are now being sapped by year-round irrigation of sugar cane fields. Prof Weeks is working with agriculture officials to look at new crops or new irrigation techniques to lower groundwater levels.

The researchers are also working with hydrological engineers to deflect catastrophic flash floods that happen perhaps just once a century.

"You will get several inches of rain dropped in a matter of minutes, the ground cannot absorb the water and so it washes down the hillside, hundreds of thousands of gallons of water bringing with it tons of sand and stone and rubble and debris. By the time it has been swept over the cliff into the valley proper, it is moving at 20mph an hour, perhaps 50cm deep, down the valley floor and of course washing into any low-lying tombs in its path," he said.

"This is the way that, over the past 3,000 years, most of the tombs in the valley have been damaged - by these kinds of floods. We can prevent that. We cannot prevent the rainfall but by the judicious angling and sloping of footpaths we can direct those floods away from the tomb entrances and out of the valley before they do any damage."

It was supposed to be the ultimate in secure burial plots. Hidden in a lonely valley, the Valley of the Kings was designed by the pharoahs to preserve their mummies and riches for eternity. It is no small irony that more than 3,000 years later the tombs, deep in the heart of the mountains, have become one of the most popular tourist attractions in the world.

The Valley of the Kings, part of the ancient city of Thebes, was the burial site of almost all the kings of the 18th, 19th, and 20th dynasties, who ruled from 1539-1075 BC. Most of the burial chambers were robbed in antiquity, many by the successors of the owners, as well as the workmen who built the tombs.

Exploration of the valley began in earnest at the start of the last century when more than 30 tombs and pits were cleared. But it really attracted world attention with the discovery in 1922 of the tomb of the boy king, Tutankhamun by British archaeologist Howard Carter.

It also led to the birth of the myth of the curse of the tomb. At the moment of discovery Carter's pet canary was swallowed whole by a cobra. To local guides, the implication was clear. The boy king, whose golden death mask was modelled on the snake, was determined to wreak revenge for the disturbance of his final resting place.