Sandstone Chamber Humidity and Tourism in Petra, Jordan: Fid-Bau Portal

Sandstone Chamber Humidity and Tourism in Petra, Jordan

Paradise, Thomas R.

Comprehensive interior and exterior humidity measurements were made in Petra's most celebrated structures, al-Khazneh and Urn Tombs, in tandem with data on visitor number and frequency. Small tourist groups entering the chambers caused interior relative humidity increases of between 5 and 15%. Statistical correlations of determination (r²) also revealed that the most significant relationships between visitor number contributions and chamber humidity occurred fifteen minutes after the visit. Correlations increased dramatically when the tourist numbers and relative humidity were viewed simultaneously (r²=0.007, 0.136), and then compared to measurements taken with a fifteen minutes lag time (r²=0.707, 0.895). These relationships indicate that it takes ten to twenty minutes for human respiration and transpiration to contribute to relative humidity in chambers of this volume (2,000–3,600 m³). Wall measurements found interior surfaces to have receded from visitor-induced abrasion (such as touching and leaning) by up to 40 mm during the 50–100-year era of increased tourism in the region. It is also indicated that a 4 × 3 m wall section has lost 500,000 cm3 of sandstone over these past 100 years, between 0.5 to 2 m above the floor, indicating surface recession from human contact where visitors commonly lean, touch or rest.