Un SIG corporativo en el IGN para la gestión integrada, publicación y análisis de datos geográficos

El Instituto Geográfico Nacional inició en el año 2003 los estudios previos necesarios para un proyecto ambicioso y a la vez esencial para el cumplimiento de sus responsabilidades básicas, la implantación de un Sistema de Información Geográfica (SIG) corporativo que atendiera a tres finalidades fundamentales: a) la gestión integrada de los datos geográficos y cartográficos que produce, en forma de Bases Cartográficas Numéricas (BCN) y en forma de mapas, respectivamente, incluyendo su actualización coordinada; b) la publicación de tales datos en papel, en soporte digital y de manera electrónica (Infraestructura de Datos Espaciales (IDE)); c) el análisis y consulta desde clientes ligeros y pesados para todo tipo de aplicaciones. Por lo tanto, el sistema constituye a la vez el soporte básico para la publicación de cartografía y para la consulta de los datos geográficos desde clientes a través de la Web,mediante el desarrollo de servicios de análisis

On the monitoring of surface displacement in connection with volcano reactivation in Tenerife, Canary Islands, using space techniques

Geodetic volcano monitoring in Tenerife has mainly focused on the Las Cañadas Caldera, where a geodetic micronetwork and a levelling profile are located. A sensitivity test of this geodetic network showed that it should be extended to cover the whole island for volcano monitoring purposes. Furthermore, InSAR allowed detecting two unexpected movements that were beyond the scope of the traditional geodetic network. These two facts prompted us to design and observe a GPS network covering the whole of Tenerife that was monitored in August 2000. The results obtained were accurate to one centimetre, and confirm one of the deformations, although they were not definitive enough to confirm the second one. Furthermore, new cases of possible subsidence have been detected in areas where InSAR could not be used to measure deformation due to low coherence. A first modelling attempt has been made using a very simple model and its results seem to indicate that the deformation observed and the groundwater level variation in the island may be related. Future observations will be necessary for further validation and to study the time evolution of the displacements, carry out interpretation work using different types of data (gravity, gases, etc) and develop models that represent the island more closely. The results obtained are important because they might affect the geodetic volcano monitoring on the island, which will only be really useful if it is capable of distinguishing between displacements that might be linked to volcanic activity and those produced by other causes. One important result in this work is that a new geodetic monitoring system based on two complementary techniques, InSAR and GPS, has been set up on Tenerife island. This the first time that the whole surface of any of the volcanic Canary Islands has been covered with a single network for this purpose. This research has displayed the need for further similar studies in the Canary Islands, at least on the islands which pose a greater risk of volcanic reactivation, such as Lanzarote and La Palma, where InSAR techniques have been used already