Digital engineering for heritage conservation: standards-aligned UAV-TLS workflow and immersive dissemination for climate-exposed heritage landscapes

The Old Great North Road (OGNR)—a component of the Australian Convict Sites World Heritage property—is increasingly exposed to pluvial runoff and bushfire hazards. This paper reports a standards-aligned digital documentation and communication workflow that combines UAV photogrammetry with terrestrial laser scanning to produce georeferenced 3D baselines for selected road-fabric attributes (culverts, retaining walls, rock surfaces and adjacent terrain). We couple capture-quality reporting with an attribute–hazard screening matrix that links Bureau of Meteorology IFD design rainfalls and Forest Fire Danger Index (FFDI) categories to inspection and maintenance triggers consistent with the OGNR Conservation Management Plan. An immersive VR/real-time visualisation layer (with documented mesh decimation and level-of-detail settings) is provided as a stakeholder communication aid while maintaining metric traceability through metadata and provenance logs. The workflow is positioned as a proof-of-concept baseline suitable for longitudinal re-survey; limitations regarding site-specific thresholds, formal VR evaluation, and broader scalability are explicitly discussed.