The fabulous Temple of Luxor has stood near the banks of the Nile River for more than 3,000 years, but it is in danger of crumbling from below as a rising water table eats away at the foundations of some of ancient Egypt's most important artifacts.
Increased irrigation throughout the region has caused the groundwater to rise at an alarming rate in recent years, and the water is quite literally dissolving the soft sandstones upon which many monuments, including the Avenue of the Sphinxes, have stood for thousands of years.
If nothing is done, "you'll get accelerated decay of the monuments and the loss of very significant Egyptian heritage," says Graham Fogg, a hydrology professor at the University of California, Davis, and one of many scientists who are trying to figure out how to save these treasures from destruction.
The modern city of Luxor grew up around the site of Thebes, the ancient capital of Egypt at a time when humans were first beginning to understand that great things could be done if they could just figure out how to work together. Those ancient Egyptians figured it out, at least to some degree, and what emerged from that astonishing epic in human history are some of the most treasured monuments on the planet.
The centerpiece of their achievement is the famed Temple of Luxor, with its towering columns. It dates back to the 14th century, B.C. Also at risk is the Avenue of the Sphinxes, a row of smaller versions of the famed Great Sphinx that, fortunately, is some distance from the Luxor area and thus not as threatened.
Like most of the ancient monuments, the Temple of Luxor has been buried repeatedly beneath the drifting sands of the Sahara Desert, only to be resurrected later by humans who recognized that it was worth almost any cost to save them. But the current threat may prove too costly, because controlling groundwater is not a simple process, and time may be running out.
Scientists from the University of Missouri, Rolla, working with the National Research Institute of Astronomy and Geophysics in Egypt, collected samples of soil, sandstones and water from six archaeological sites in Luxor last year. After analyzing the samples back in their lab, the researchers concluded that the rising water table — most likely caused by increased irrigation — posed a real threat to the monuments.
Unfortunately, the sandstone used in the structures is porous and weak, and that makes it very vulnerable to water damage. It soaks up the groundwater like a paper towel, eroding the rocks and leaving salt deposits that increase the rate of degradation.
That rate has soared dramatically in recent years, according to civil engineer Adam Sevi of the University of Missouri, a member of the research team.
There have been several efforts to curb the problem, including one attempt to pump the water from the ground back into the Nile, thus lowering the water table. But to make much of an impact, millions of gallons would have to be removed, and it's not clear at this point that that's economically feasible.
No attempt to address the problem is likely to be cheap.
Piping It Out
Fogg, the Davis hydrologist who was brought into the project by a graduate student from Egypt, believes it may be possible to lay drainage pipes throughout the monument area and simply drain water away, probably back into the Nile.