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UID:pretalx-foss4g-2026-CZP37F@talks.osgeo.org
DTSTART;TZID=JST:20260902T153000
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DESCRIPTION:1-Introduction and Background\nThe geography of ancient Egypt a
 nd its mythology are closely connected\, with the annual flooding of the N
 ile shaping both the physical landscape and the cultural worldview. In anc
 ient Egyptian cosmology\, the world emerged from a primordial watery void 
 (Nun) as the first land\, or "primeval mound". This study focuses on Esna\
 , Upper Egypt\, home to the Temple of Khnum and several other unexcavated 
 or demolished temple sites. Inscriptions from the temple\, such as the Fes
 tival of Seizing the Staff\, metaphorically describe the local terrain as 
 marshlands and document processional routes. While traditional Egyptologic
 al methods have correlated some text-based place names with physical locat
 ions\, they often lack quantitative spatial analysis\, leaving the precise
  geomorphological context of these narratives largely undefined. Macro-top
 ography remains stable for a long time\, barring massive modern anthropoge
 nic intervention. This research adopts a landscape-first approach. By leve
 raging open-source geographic information systems (GIS) and remote sensing
 \, we mathematically translate qualitative ancient texts into a DEM-driven
  topographic model to reconstruct the historical landscape that inspired t
 he legends.\n\n2-Study Area and Open Data Sources\nThe study area is Esna\
 , with five documented temple sites surrounding it: Temple of Khnum\, Hous
 e of God\, the Temple of Isis\, and Kom Mir. The construction of the Aswan
  High Dam has masked historical paleochannels and floodplains\; insufficie
 nt data are available for hydrological reconstruction. Consequently\, this
  study heavily prioritizes Digital Elevation Models (DEMs). We lean on dec
 lassified 1960s CORONA panoramic stereo pairs to extract a pristine bare-e
 arth microtopography\, capturing the landscape long before recent agricult
 ural expansion and infrastructure projects leveled it. We then complement 
 this historical topographic baseline with decades of multispectral data fr
 om Sentinel-2 and the Landsat program (Landsat 1–9) to monitor remaining
  vegetation patterns and water indices. Aligning with the core philosophy 
 of FOSS4G\, our primary computational platform (QGIS) and all incorporated
  remote sensing datasets are entirely open-access.\n\n3-Methodology\nTo br
 idge the gap between mythological narratives and spatial reality\, we deve
 loped a reproducible\, DEM-centric workflow using QGIS and Python spatial 
 libraries. The best method we can use is layer analysis\, which can turn q
 ualitative contents into different GIS layers. The layers can be easily li
 nked and operated with different calculations. The methodology includes th
 ree parts:\nFirst\, textual descriptions are converted into topologically 
 validated GIS layers. Layer 1 represents the "Primeval Mound" (elevated\, 
 unflooded zones)\, Layer 2 represents "Marshes & Lakes" (low-lying retenti
 on basins)\, and Layer 3 delineates the "Western Mountains" (the absolute 
 safety boundary).\nSecond\, we execute rigorous Topographic Surface Modeli
 ng. Based on terrain stability\, we use QGIS terrain analysis algorithms t
 o compute critical geomorphological variables from the historical DEM. By 
 calculating slope\, aspect\, Topographic Position Index (TPI)\, and the To
 pographic Wetness Index (TWI)\, we quantitatively define the physical land
 scape characteristics\, isolating potential ancient mounds from natural de
 pressions.\nThird\, we perform Hydro-conditioning and Simulated Routing. S
 ince modern hydrology is severely disrupted\, we reverse-engineer the anci
 ent floodpaths through the terrain. We apply open-source algorithms to hyd
 ro-condition the DEM—executing pit-filling\, flow-direction\, and flow-a
 ccumulation routing—to establish a hydrologically correct surface. A ter
 rain-based inundation algorithm\, such as the Height Above Nearest Drainag
 e (HAND) model\, is then deployed. By routing simulated water levels acros
 s this stable topography\, the inundation results are meticulously calibra
 ted to match the spatial descriptions in the ancient texts.\n\n4-Prelimina
 ry Results and Archaeological Implications\nCurrently\, the DEM-driven spa
 tial analysis successfully bridges the text-to-terrain gap. Our analysis o
 f Layer 3 (the "Western Mountains") exposes a significant divergence betwe
 en mythological narratives and physical geography. While the inscriptions 
 describe this western margin as an impassable\, absolute safety zone\, the
  DEM analysis reveals it to be a modest ridge with an average elevation of
  only 200 to 300 meters. Furthermore\, extracting elevation profiles from 
 our decadal remote-sensing time series confirms that this topography has r
 emained geomorphologically static\, ruling out historical degradation. Thi
 s discrepancy suggests that the ancient characterization was a phenomenolo
 gical exaggeration\, likely stemming from limited mobility and the imposin
 g visual perspective of looking westward from the low-lying Esna basin. Id
 entifying this spatial hyperbole is archaeologically significant\; it demo
 nstrates a broader tendency for cognitive exaggeration within the temple t
 exts\, providing a critical\, data-driven foundation for reinterpreting ot
 her geographic claims in the inscriptions.\nOur geomorphological computati
 ons explicitly identified elevated landforms and topographical depressions
  that align flawlessly with the text-derived topological layers. The hydro
 -conditioned HAND model effectively simulates the historical flood recessi
 on zones\, demonstrating how rising waters would inundate the natural basi
 ns (Layer 2) and expose the structurally sound primeval mounds for temple 
 construction (Layer 1). \n\n5-Conclusion and Future Work\nThis study estab
 lishes a robust methodological blueprint for landscape archaeology. By piv
 oting from a purely hydrological focus to a terrain-driven analysis\, we d
 emonstrate how open-source GIS tools can bypass modern infrastructural dis
 ruptions to reconstruct ancient environments. The calibrated\, DEM-based i
 nundation model not only contextualizes the past but also serves as a pred
 ictive tool.\nFuture work will focus on:\nFirst\, we will broaden the temp
 oral depth of our spatial database by incorporating and georeferencing ear
 ly historical cartography (e.g.\, 18th- and 19th-century expedition maps).
  This process will cross-validate our findings and further corroborate the
  millennial topographic stability of the Esna geomorphology.\nSecond\, we 
 will expand our textual dataset—currently focused on the Festival of Sei
 zing the Staff—to include inscriptions from other major local events\, s
 uch as the Festival of Raising the Sky. Cross-referencing these distinct m
 ythological narratives will allow us to generate additional topological la
 yers and conduct rigorous statistical evaluations to assess their spatial 
 validity and accuracy.\n\nReferences:\n[1] Sauneron\, S. (1962). Le temple
  d'Esna. Tome V: Les fêtes religieuses d'Esna aux derniers siècles du pa
 ganisme. Le Caire: IFAO.\n[2] Abdel-Raham\, A. M. (2009). The Lost Temples
  of Esna. BIFAO\, 109\, 1-8.\n[3] Assmann\, J. (1996). The Mind of Egypt: 
 History and Meaning in the Time of the Pharaohs. Metropolitan Books.
DTSTAMP:20260717T234910Z
LOCATION:Cosmos2
SUMMARY:From Ancient Legends to Pixels: Reconstructing Ancient Esna Landsca
 pe with GIS and Remote Sensing - TonyLiu
URL:https://talks.osgeo.org/foss4g-2026/talk/CZP37F/
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