At the water’s edge: photogrammetry in extreme shallow water environments

Coastal, riverine, and lacustrine environments have played a central role in the development of human societies. Locating and documenting this record of activity in shallow-water environments has, however, proven difficult. Terrestrial survey methods reach their limit at the water’s edge, and marine geophysical methods often struggle with shallow depths. This zone, dubbed the ‘white ribbon’ due to the absence of data, thus represents a longstanding methodological gap. Recent research on archaeological islands in Scotland, more commonly known as crannogs, has underscored these difficulties while also offering insights and practical solutions.<br/>This paper presents a high-resolution, repeatable photogrammetric workflow designed to integrate extreme shallow-water (&lt; 1 m) and aerial surveys. It employs stereoscopic photogrammetry to generate artificial scale bars and RTK-GPS control points to enable data integration. By adapting standard terrestrial and underwater survey methods we were able to develop a cost-effective, repeatable and accurate solution to recording sites that straddle the water’s edge. The results not only advance the study of crannogs but also establish a replicable framework for investigating other challenging littoral environments, particularly inland lakes and rivers where tidal exposure cannot be relied upon.<br/>