Pitfalls of multiplied 3D landforms projection: mapping deep multilevel cave systems in the Alps (Gamssteig Cave System, Göll Massif)

Cave mapping represents one of the most complex challenges in geomorphological cartography, as it must convey the true three-dimensional geometry of subterranean spaces such as overlapping passages, irregular cross-sections, and variable ceiling and floor morphologies, within a two-dimensional framework. This study examines the methodological and interpretive challenges of cave mapping, utilizing the Gamssteighöhle cave in the Austrian Alps as a case study. During the 11 years of exploration, over 10 km of passages were surveyed using the DistoX vector survey method. Yet, the complex morphological forms necessitated deviations from the standard symbology recommended by the International Union of Speleology. Several key visualization challenges are analyzed, including subvertical pits, overlapping passages, and 3D maze-like networks. Solutions such as multiple projection planes, transparency effects, perpendicular cross-sections, and splitting maps into separate sheets are proposed to maintain readability and spatial context. We evaluate traditional vs. LiDAR-based mapping, concluding that while dense 3D point clouds offer exceptional precision, they do not inherently yield readable or informative maps. Cartographic generalization, with its interpretative input of the cartographer, remains indispensable for transforming spatial data into coherent and communicative cave maps. LiDAR and photogrammetry greatly enhance visualization and quantitative analysis but complement rather than replace traditional mapping.