Shallow geophysical techniques to investigate the groundwater table at the Great Pyramids of Giza, Egypt

• Main Authors: S. M. Sharafeldin, K. S. Essa, M. A. S. Youssef, H. Karsli, Z. E. Diab, N. Sayil
• Format: Article
• Language: English
• Published: Copernicus Publications 2019-02-01
• Series: Geoscientific Instrumentation, Methods and Data Systems
• Online Access: https://www.geosci-instrum-method-data-syst.net/8/29/2019/gi-8-29-2019.pdf
• ISSN: 2193-0856; 2193-0864

<p>The near-surface groundwater aquifer that threatened the Great Pyramids of Giza, Egypt, was investigated using integrated geophysical surveys. A total of 10 electrical resistivity imaging, 26 shallow seismic refraction, and 19 ground-penetrating radar surveys were conducted in the Giza Plateau. Collected data for each method were evaluated by state-of-the art processing and modeling techniques. A three-layer model depicts the subsurface layers and better delineates the groundwater aquifer and water table elevation. The resistivity of the aquifer layer and seismic velocity vary between 40 and 80&thinsp;<span class="inline-formula">Ω</span>m and between 1500 and 2500&thinsp;m&thinsp;s<span class="inline-formula">⁻¹</span>, respectively. The average water table elevation is about <span class="inline-formula">+</span>15&thinsp;m, which is safe for the Great Sphinx, but it is still subjected to potential hazards from the Nazlet El-Samman suburb where the water table elevation reaches 17&thinsp;m. A shallower water table at the Valley Temple and the tomb of Queen Khentkawes, with a low topographic relief, represents severe hazards. It can be concluded that a perched groundwater table is detected in the elevated topography to the west and southwest that might be due to runoff and capillary seepage.</p>