Paleotopographical virtual reconstruction of the historic city of Cartagena (Spain)

Abstract

[EN] The city of Cartagena and its immediate surroundings have experienced significant topographical changes throughout its history. Originally built on five hills which border south and west with the Mediterranean Sea, the city has expanded to the north over the last five decades, occupying a lacustrine system which has now dried up due to the diversion of riverbeds which, from time to time, used to flood the place. These changes have been documented and studied from the lithology present in over 400 geotechnical drillings carried out in the urban renewal of the city for the last two decades. In addition, another 20 new continuous drillings have been conducted within the Project “Surveying and planning a privileged Mediterranean city, Arqueotopos I and II” which is still ongoing. The information obtained is completed with the study of all existing historical maps on it. Digital Terrain Models (DTMs) have been generated with this drilling data, then several lithological layers have been selected for its interest: anthropic fill, mud and underlying bedrock. The thickness of each of the layers has been studied in different areas and viewed through various longitudinal profiles that have been plotted. Finally, a three-dimensional (3D) virtual reconstruction has been undertaken to see graphically the documented changes that have occurred in each of these layers, to serve both research and divulgation knowledge.

[ES] LaciudaddeCartagenaysu entornoinmediato haexperimentadosignificativos cambiostopográficos alo largo desu historia. La ciudad, levantada originariamente sobre cinco cerros que limitan al sur y al oeste con el mar Mediterráneo, se ha extendido en las últimas décadas hacia el norte, ocupando un sector lacustre subsidente, ahora desecado por el desvio de los cauces que recurrentemente lo encharcaban. Estos cambios han sido documentados y estudiados a partir de la litología presente en cerca de 400 sondeos geotécnicos realizados en la renovación urbana de la ciudad durante las dos últimasdécadas,asícomoenotros20nuevossondeosdeperforacióncontínuarealizadosdentrodelosProyectos “Topografía y urbanismo de una urbe mediterránea privilegiada, Arqueotopos I y II” actualmente en curso. La información obtenida se ha completado con el estudio de toda la cartografía histórica existente sobre la misma. Desde esta información se han elaborado modelos digitales del terreno (MDTs) de distintas capas litológicas seleccionadas por su interés: relleno antrópico, fangos y roca subyacente. Se ha podido estudiar así la potencia de cada una de las capas en diferentes zonas yvisualizarlasatravésdelosdistintosperfileslongitudinalesquesehantrazado.Finalmente,seharealizadouna reconstrucciónvirtual tridimensional(3D) quepermite apreciar gráficamente lasvariaciones documentadasque sehan producido en cada una de dichas capas, con fines tanto investigadores como de divulgación.