ABOUT 4,500 years ago, Asia's first great civilization flourished on the banks of the Indus River. A contemporary of ancient Egypt and Mesopotamia, the Indus civilization dominated an area greater than these two Western cultures put together. Its ruins hold the roots of modern society in the Indian subcontinent.
But the excavated remains of the civilization's capital, one of the world's great archaeological treasures, are crumbling with alarming speed.
Preserved for millennia in the sands of Sind, buildings dug up and rebuilt less than 30 years ago have turned to tumbledown heaps of brick. And the bricks are quickly turning to powder. Salty ground water is seeping up into the bricks, where the salt crystalizes and literally explodes, explains UNESCO conservator Richard Hughes.
Though salty brick clay troubled Moenjodaro's ancient inhabitants, the problem of crumbling bricks has recently grown acute. A century of irrigating land without proper drainage is turning the Indus basin into a salty wasteland. Vast tracts of Sind virtually float on a sea of brine.
Observed New York University archaeologist Rita Wright upon seeing the salt damage at Moenjodaro: "I can't think of any other site of baked brick that has this salinity problem."
The Pakistan government held its second international symposium on Moenjodaro in February. At the first one, in 1973, participants helped hammer out the site's master plan, including a five-year conservation program.
Since then UNESCO, which lists Moenjodaro as a World Heritage Site, has contributed $7 million to preserve the ancient city. In addition, the Pakistan government has spent $5 million (at current exchange rates). Pressured by donors, the government archaeology department and the Authority for the Preservation of Moenjodaro convened the recent symposium primarily to review the plan. Members loudly criticized the two agencies.
The authority has built elaborate ground water and flood-control systems but has not done enough to conserve excavated ruins, observed UNESCO representative Hideo Noguchi. After 11 years, the archaeology department, which actually carries out the site's conservation, has completed work on only 30 percent of excavated remains, according to department reports. And much completed work is of questionable value. Neither the authority nor the department has seriously studied its effects, says Mr. Hughes.
When asked about conservative efforts at Moenjodaro, Ahmed Nabi Khan, the archaeology department's director general, refused to comment. authority director general Ghulam Khichi dismissed similar questions. "You cannot make us accountable," he said. "We are not accountable."
To protect underground ruins from salty water, the authority has ringed Moenjodaro with tube wells. The agency claims this system is holding groundwater at 10 meters (33 feet) below the surface. During the symposium, about 100 archaeologists and other guests toured the works. They were shown drainage pipes gushing water into already brimming canals. But archaeologists who frequently visit the site complain that this was all for show. The pumps are run only during official monitoring periods and for displ ay to visiting dignitaries, they say.
Experts estimate that each well must pump at least 80 percent of the time for the drainage system to work. But the pumps run on electricity, and monthly bills reach about $30,000. Archaeologists accuse the authority of cutting costs by running the pumps only intermittently.
"Every time I've visited unofficially, the pumps have been turned off," says a Western archaeologist who goes to Moenjodaro several times a year.
Swelling with Himalayan snowmelt, the Indus River rises about 16 meters (52 1/2 feet) in winter and threatens Moenjodaro with floods. To deflect water from the ruins, the authority has built dikes along the banks and spurs (artificial sandbars) in the river.
Upon seeing the dirt dikes, F. R. Allchin, professor emeritus at Cambridge University in England, gasped, "What a shame! It's absolutely tragic what they've done!"
The dikes have been covered with loose limestone trucked from the nearby Rohri Hills, Mr. Allchin explains. Run through with thick veins of flint, the hills hold the remains of tool factories that supplied the entire Indus civilization. The limestone quarries had been archaeological troves full of information about Indus tools and technology.
BUT the authority destroyed the factory remains before they could be excavated and documented.
"In 1975, we could find the very seats of workers - where they had actually sat - with waste piles next to them," lamented Allchin. "Now they're gone."
The Rohri Hills, 160 kilometers (99 miles) from Moenjodaro, are technically beyond the authority's concern. "Why should I reject the limestone?" asked authority chairman Abdul Kadir Shaikh with a shrug. "It is not my responsibility."
The Indus culture flourished from about 2500 to 1800 BC. Also called the Harappan culture, it was discovered in 1921 at the Punjab town of Harappa. A year later remains were found at Moenjodaro. Finding no grand temples or monuments to rival the pyramids, archaeologists dismissed Asia's first civilization as second-rate, a cultural stepchild of its Western contemporaries. Newer analysis rejects such notions, however. Today, the Indus culture is recognized as equal, and in some ways superior, to its Bronz e Age contemporaries.
At its height, the culture covered much of modern Pakistan, extending from the Arabian Sea to northern Afghanistan and into Indian Punjab and Gujarat. With an area of more than 1 million square kilometers (385,600 million square miles), the civilization was a quarter bigger than Pakistan. And its individual cities were also large. Moenjodaro's estimated population is 450,000 - more than twice that of any contemporary city in the region.
Less than 10 percent of Moenjodaro's surface has been uncovered, and the lowest depths have yet to be reached.
"It's a rich source of third millennium [BC] life, says Dr. Michael Jansen, who has supervised research at the site since 1979, "and we are just beginning to learn about it.'