RESUMO
An important geological risk to which many towns in Puglia are exposed is sinking cavities in urban areas. For urban centers, studying, mapping, providing geological and speleological descriptions, classifying, and cataloging the forms and types of cavities is essential because cavities are linked to past local anthropic and natural processes at different sites. These circumstances could lead to the enhancement of existing underground cavities in urban areas through conservation and continuous monitoring. Unfortunately, in many cases, these underground cavities have been used as landfills and subsequently abandoned. In late March 2007, one of these cavities collapsed inside Gallipoli's inhabited center, causing damage to the structures but fortunately not human lives. In the area surrounding the collapsed cavity, a series of geophysical investigations were undertaken using ground penetrating radar in an attempt to delimit the area of collapse and develop possible interventions for restoration. In the same area, these measures were repeated 16 years later in December 2022 due to another collapse. The comparison between data acquired in these two periods shows that there were no strong changes apart from an increased presence of subsoil moisture in 2022.
RESUMO
The church of Santa Maria della Lizza is one of the most important examples of medieval architecture in the Salento Peninsula in south Italy. In order to understand the extension and layout of the crypts, integrated ground-penetrating radar (GPR) prospections and laser scanner surveys were undertaken in the church and in the surrounding areas. The analysis of the GPR measurements revealed many anomalies that could be ascribed to unknown structures (crypts), as well as other anomalies related to the old church. The GPR data were supported by the laser scanner data establishing the spatial relationship between the surface and the level below the church.