Emergent heritage: the digital conservation of archaeological sites in reservoirs and the case of the Dolmen de Guadalperal (Spain)

The dolmen of Guadalperal (Spain) became well known in 2019 when the waters of the reservoir in which it had long been submerged became so depleted as to leave it above water and highly visible. This gave rise to great media and social polemic. In this study, we deal with the ‘recovery’ of the dolmen using digital techniques, including a strategy of geometrical documentation of long, medium and short-range through the use of terrestrial laser scanning (TLS) and photogrammetry. The result is a set of products that trace the changes that have taken place in the monument since its excavation in 1925, the identification of conditions affecting it and the acquisition of new information on the decorated supports that formed part of the megalithic architecture. To do so, the time during which it was accessible (i.e., not underwater) was used to acquire the only heritage information currently available on the monument. This new information offers a complete assessment of a megalithic monument using a protocol that is exportable to other sites submerged in lakes or reservoirs.