Hydraulic and urban management during Roman times based on GIS and remote sensing analysis (Clunia, Spain)

Rosa Cuesta, Ignacio Fiz, Eva Subias, Francesc Tuset, Miguel Ángel de la Iglesia

The Roman city of Clunia (nowadays at the Spanish province of Burgos) became the capital of the Tarraconensis conventus with the Augustan provincial reform, which provided a major boost for its urban development. The suitability of the city’s location is evident by the fact it was built on a plateau concealing an underground karst cave that provided direct access to water without requiring major engineering works. The waters in this cave were used and administered by the people, and some of its galleries acted as a shrine for worshipping.

This study provides an overview of the modern drainage systems in order to study more profoundly the forms of urban organization, on which we have only partial knowledge currently, given the breadth of the field. We believe that some of these drains are actually tracks of ancient streets that have been fossilized in orography. To reach these conclusions, we analysed several IR photographs, and applied hydrological GIS functions to observe the path of these tracks and their relationship to what is currently known of the city’s urban layout. This analysis of the surface was completed by relating it to the karst topography by conducting geophysical surveys in areas where wells giving access to the cave were detected using radiolocation. Finally, we applied a range of hydrological GIS functions and indexes on a high-resolution DEM, obtained from LIDAR technology (5 m/pixel), to confirm how the drainage worked.

The results have highlighted landforms on the plateau, providing new hypotheses about Clunia’s urban development. Repetitive modulations were also observed in the distances between some of the drains, thus making for a better understanding of the characteristics of an entire sector of the ancient city. We therefore believe that the drainage calculation method may be a useful tool for the study of urban structures that have not been excavated yet.
Keywords: Remote Sensing; Drainage System; GIS; Hydrological Index; Roman Archaeology.