Differences between a map of thermal data type and a 3D SIG based map o the same element (Estela de Cenicientos, Madrid)
A research carried out at Universidad Politécnica de Madrid suggests a new mapping method based on non-destructive testing on historic buildings using SIG techniques. A female researcher from the School of Architecture at Universidad Politécnica de Madrid has mapped data of heritage constructions that was not possible before with conventional methods. Thanks to the new method, the researcher was able to map diverse factors such as humidity, evaporation, salinity and material degradation. Thus, this powerful tool can interpret the dynamic processes of deterioration on historic buildings by providing a right and rigorous interpretation of data in order to restore such buildings.
Digital image processing combined with geographic information systems give as a result a new usage of mapping heritage asset. For example, this method can generate a new map from another existing one and can be used and extended by the diverse agents that work on such asset throughout its process of restoration, conservation, dissemination and management. The complex process of studying an architectonic element is better understood when we generate maps from a combination of different data maps in which we observe variations over time. However, although test instruments provide accurate timely information they do not provide the necessary overview for its right interpretation, thus we need to use SIG systems in order to achieve this objective.
In this way, a research in this subject has been carried out within the Geomaterial Program, funded by the Community of Madrid and the European social fund. This study, which was carried out by Laura López-González from the School of Architecture at Universidad Politécnica de Madrid, proposes a new a method based on non-destructive testing on historic buildings using SIG techniques. Thanks to this method, we can produce and convert a 3D map, based on cloud points from an architectural element obtained by photogrammetry, into raster and vector cartography, legible by SIG mapping systems using a particular coordinate system that will refer each cloud point obtained by photogrammetry. This initial mapping will be named base planimetry. The method by which the points where the non-destructive testing is performed are referenced to the coordinate system of the base plane , which allows the generation of maps of the referenced tests and the possibility of obtaining different data from multiple tests on the same base plane. These new maps are named mapping data and allowed to map unpublished data so far.
The mapping of various factors (humidity, evaporation, salinity, degradation of the material, etc) comparable over time has been achieved for the first time through map algebra. This cartography and data are finally a unique file, a 2D and 3D planimetry database in which we can dump data from the different agents involved. In this way, different databases can be linked to the digital cartography, meaning a dynamic cartography. This system will provide a better vision of all data obtained in the study of historical buildings, and will ease the proper and rigorous data interpretation for its subsequent restoration. Laura López-González says, “this new mapping will enable the interdisciplinary work in the elaboration of the diagnosis and will be useful for both deterioration and moisture study which are frequent damages in heritage restoration”.