Assessing the impact of Nile water level fluctuations on the structural stability of the Philae temples in Aswan, Egypt

The ancient Egyptian temples at the Philae UNESCO World Heritage Site in Aswan face conservation challenges due to fluctuating water levels, which threaten their building material resistance. Following a summary review of the hydrological changes to the natural responses of the Nile caused by the construction of the Aswan dam, our research employs a novel approach, combining remote sensing data analysis, literature review, fieldwork, and multiple high-specification materials analyses, to assess the impact of these changes on the temples in Philae. The new data permit the identification of the most at-risk areas and inform the long-term monitoring and conservation of Philae. Our approach enhances understanding of the causes and effects of building material decay and underscores the urgent need for conservation strategies to mitigate ongoing water-induced deterioration. The research highlights the impact of human-induced hydrological changes, offering a case study that informs future climate change effects. It is clear that tough decisions will be required for the long term heritage conservation of the Philae temples in the face of modern infrastructural developments and climate change, and that cultural heritage management guidelines before and after dam construction is urgently required. The issues identified, are not unique to the Philae Temples so the results and recommendations are relevant to other World Heritage sites that are currently facing similar environmental and conservation challenges. • Nile water level changes, intensified by dams, hasten decay in sandstone structures. • Osiris Temple on Bigeh Island, submerged, suffers instability from prolonged water exposure. • Water saturation weakens sandstone, reducing strength and altering its surface. • Study urges water management, barriers, and monitoring to protect UNESCO monuments.