Subsidence activity maps derived from DInSAR data: Orihuela case study

A new methodology is proposed to produce subsidence activity maps based on the geostatistical analysis of persistent scatterer interferometry (PSI) data. PSI displacement measurements are interpolated based on conditional Sequential Gaussian Simulation (SGS) to calculate multiple equiprobable realizations of subsidence. The result from this process is a series of interpolated subsidence values, with an estimation of the spatial variability and a confidence level on the interpolation. These maps complement the PSI displacement map, improving the identification of wide subsiding areas at a regional scale. At a local scale, they can be used to identify buildings susceptible to suffer subsidence related damages. In order to do so, it is necessary to calculate the maximum differential settlement and the maximum angular distortion for each building of the study area. Based on PSI-derived parameters those buildings in which the serviceability limit state has been exceeded, and where in situ forensic analysis should be made, can be automatically identified. This methodology has been tested in the city of Orihuela (SE Spain) for the study of historical buildings damaged during the last two decades by subsidence due to aquifer overexploitation. The qualitative evaluation of the results from the methodology carried out in buildings where damages have been reported shows a success rate of 100%.

Elogio del cuadrado: cuadrícula, cuadro, cuatro, cubo

Un recorrido por la producción de Le Corbusier evidencia la insistente presencia del cuadrado como base de las composiciones en diversos campos (urbanismo, arquitectura, pintura, mobiliario...) y en diferentes formatos (en planta, alzado y sección, o como marco, módulo y cuadrícula). La presente comunicación realiza un análisis formal (gráfico y simbólico) de sus proyectos y obras, rastreando los modos en que se utiliza el cuadrado permaneciendo en el tiempo como una constante recurrente. Para ello se recorren cuatro áreas temáticas que descienden en escala y en dimensiones: 1) capitolios, 2) museos, 3) pabellones y 4) casas, estudiando una serie de ejemplos en cada área a partir de los planos de la Fundación Le Corbusier, generando discursos que reconstruyen un hilo del tiempo en la evolución de los procesos compositivos. De este modo, se desgrana el empleo del cuadrado, en correspondencia con las áreas de estudio, como: 1º) perímetro de la plaza pública donde insertar las arquitecturas representativas, 2º) marco o caja-fuerte donde encerrar los tesoros artísticos (o sagrados), 3º) volumen cúbico abierto y desmontable y 4º) caja definida por la retícula de la estructura. El cuadrado es siempre un medio y no un fin. Persiste un intento de sugerir algunos de los orígenes en su formación clasicista, sus viajes y sus pinturas.

Topological SLAM using a graph-matching based method on omnidirectional images

Comunicación presentada en el XI Workshop of Physical Agents, Valencia, 9-10 septiembre 2010.

A GIS-based methodology to quantitatively define an Adjacent Protected Area in a shallow karst cavity: The case of Altamira cave

Different types of land use are usually present in the areas adjacent to many shallow karst cavities. Over time, the increasing amount of potentially harmful matter and energy, of mainly anthropic origin or influence, that reaches the interior of a shallow karst cavity can modify the hypogeal ecosystem and increase the risk of damage to the Palaeolithic rock art often preserved within the cavity. This study proposes a new Protected Area status based on the geological processes that control these matter and energy fluxes into the Altamira cave karst system. Analysis of the geological characteristics of the shallow karst system shows that direct and lateral infiltration, internal water circulation, ventilation, gas exchange and transmission of vibrations are the processes that control these matter and energy fluxes into the cave. This study applies a comprehensive methodological approach based on Geographic Information Systems (GIS) to establish the area of influence of each transfer process. The stratigraphic and structural characteristics of the interior of the cave were determined using 3D Laser Scanning topography combined with classical field work, data gathering, cartography and a porosity–permeability analysis of host rock samples. As a result, it was possible to determine the hydrogeological behavior of the cave. In addition, by mapping and modeling the surface parameters it was possible to identify the main features restricting hydrological behavior and hence direct and lateral infiltration into the cave. These surface parameters included the shape of the drainage network and a geomorphological and structural characterization via digital terrain models. Geological and geomorphological maps and models integrated into the GIS environment defined the areas involved in gas exchange and ventilation processes. Likewise, areas that could potentially transmit vibrations directly into the cave were identified. This study shows that it is possible to define a Protected Area by quantifying the area of influence related to each transfer process. The combined maximum area of influence of all the processes will result in the new Protected Area. This area will thus encompass all the processes that account for most of the matter and energy carried into the cave and will fulfill the criteria used to define the Protected Area. This methodology is based on the spatial quantification of processes and entities of geological origin and can therefore be applied to any shallow karst system that requires protection.