Image of the week - Monumental modeling
Despite the monumental nature of the world's heritage sites, they are quite vulnerable to the vicissitudes of their environment. Wind and water erosion wear them down, destroying historic features we may never be able to recapture.
To understand how the winds are changing the shape of the monuments on the Giza Plateau in Egypt, Ashraf Hussein and Hisham El-Shishiny created a three dimensional model of the region. Then they simulated the flow of the wind across the Giza Plateau to see where the wind pressure and friction is greatest.
This simulation was unusual because it had to handle large differences in scale among the various monuments on the Giza Plateau. To complicate matters, within the lower atmosphere the wind field must be resolved on very fine scales to achieve a high level of accuracy, said El-Shishiny.
To complicate matters, the problem size was much greater than the available computational resources. Ultimately, they ran the simulations on a cluster of 3 GHz Pentium IV processor workstations, each with 2 GB ram.
A model is only as good as its ability to make accurate predictions. That's why the last slide is perhaps the most important: it shows pictures of the actual erosion of the Great Sphinx side by side with pictures that illustrate the model's predictions for those same areas.
"The present work may give more insight on the effect of wind around the Giza Plateau when developing a global plan for conserving and protecting the site," said El-Shishiny.
What next? Similar simulations that look at the wind-driven sand (which has completely buried the Sphinx several times throughout its history) are in the works, as well as research into the possibility of building a wall to reduce the wind's influence on the Great Sphinx.
|The images in this slideshow were taken from a paper published by Ashraf S. Hussein and Hisham El-Shishiny in the March 2009 issue of Environmental Modelling and Software. Images courtesy of Ashraf S. Hussein and Hisham El-Shishiny, IBM Center for Advanced Studies in Cairo, IBM Cairo Technology Development Center, IBM WTC, Egypt Branch.|