SAGE PublicationsGielen, E.; Riutort-Mayol, G.; Palencia Jiménez, JS.; Cantarino-Martí, I. (2017) Analysis to obtain a single (unidimensional) measuring index of sprawl, which also allows us to obtain the uncertainty of the inferred index, in contrast to traditional approaches. All these techniques have been applied to study the phenomenon of urban sprawl at the municipality level in Valencia, Spain using a wide set of variables related to the characteristics and patterns of urban land use.
This paper describes a high resolution land cover data set for Spain and its application to dasymetric population mapping (at census tract level). Eventually this vector layer is transformed into a grid format. The work parallels the effort of the Joint Research Centre (JRC) of the European Commission, in collaboration with Eurostat and the European Environment Agency (EEA), in building a population density grid for the whole of Europe, combining CORINE Land Cover with population data per commune. We solve many of the problems due to the low resolution of CORINE Land Cover, which are especially visible with Spanish data. An accuracy assessment is carried out from a simple aggregation of georeferenced point population data for the region of Madrid. The bottom-up grid constructed in this way is compared to our top-down grid. We show a great improvement over what has been reported from commune data and CORINE Land Cover, but the improvements seem to come entirely from the higher resolution data sets and not from the statistical modelling in the downscaling exercise. This highlights the importance of providing the research community with more detailed land cover data sets, as well as more detailed population data. The dasymetric grid is available free of charge from the authors upon request.
RESUMEN.-El aparato estudiado constituye un sistema glaciar de derrubios en el que se diferencian tres sectores: superior, con núcleo de hielo, cobertura de clastos, y procesos periglaciares muy activos; medio, glaciar negro, con un sector de glaciar sucio o semicubierto; e inferior, en el frente del sistema, constituye una forma de glaciar rocoso estricto. Dada la frescura de las formas conservadas y la lenta respuesta de los sistemas de derrubios glaciares a ios cambios climáticos, así como la presencia de sendas morrenas atribuidas a la Pequeña Edad de Hielo que enmarcan el aparato, puede que el momento de detenimiento de la dinámica que generó el frente rocoso del Besiberri noroccidental no exceda de unas decenas de años. SUMMARY.-The studied complex is a glacial debris system with three different areas: The upper, vv/fh an ice core covered by glacial debris and very active periglaciai processes; the middle, a black glacier with a semi-covered part; and the lower, a rock glacier in the front of the complex. The end of the dynamics that generated the glacial system doesn't exceed the last few decades. This is deduced from the good preservation of the forms, the slow response of the glaciar sistem to the climatic changes and the presence of Little Ice Age moraines surrounding the complex. RESUME.-L'ensemble étudié constitue un système glaciaire de terrains affouillés où l'on distingue trois parties: la partie supérieure, avec noyau de glace, converture de roches clastiques et processus périglaciaires très actifs; la partie moyenne: glacier noir, avec zone glaciaire sale ou semi-recouverte; et la partie inférieure, sur le front du système, qui constitue une forme stricte de glacier rocheux. Etant donné la fraîcheur des formes conservées et la réponse lente des systèmes d'affouillement glaciaires face aux modifications climatiques, ainsi que la présence des moraines correspondantes, que l'on a datées au Petit Recibido en Diciembre de 1991.
The issue of reallocating population figures from a set of geographical units onto another set of units has received a great deal of attention in the literature. Every other day, a new algorithm is proposed, claiming that it outperforms competitor procedures. Unfortunately, when the new (usually more complex) methods are applied to a new data set, the improvements attained are sometimes just marginal. The relationship cost‐effectiveness of the solutions is case‐dependent. The majority of studies have focused on large areas with heterogeneous population density distributions. The general conclusion is that as a rule more sophisticated methods are worth the effort. It could be argued, however, that when we work with a variable that varies gradually in relatively homogeneous small units, simple areal weighting methods could be sufficient and that ancillary variables would produce marginal improvements. For the case of reallocating census data, our study shows that, even under the above conditions, the most sophisticated approaches clearly yield the better results. After testing fourteen methods in Barcelona (Spain), the best results are attained using as ancillary variable the total dwelling area in each residential building. Our study shows the 3‐D methods as generating the better outcomes followed by multiclass 2‐D procedures, binary 2‐D approaches and areal weighting and 1‐D algorithms. The point‐based interpolation procedures are by far the ones producing the worst estimates.
Abstract. This paper proposes a method of valuing the stock of residential buildings in Spain as the first step in assessing possible damage caused to them by natural hazards. For the purposes of the study we had access to the SIOSE (the Spanish Land Use and Cover Information System), a highresolution land-use model, as well as to a report on the financial valuations of this type of building throughout Spain. Using dasymetric disaggregation processes and GIS techniques we developed a geolocalized method of obtaining this information, which was the exposure variable in the general risk assessment formula. Then, with the application over a hazard map, the risk value can be easily obtained. An example of its application is given in a case study that assesses the risk of a landslide in the entire 23 200 km 2 of the Valencia Autonomous Community (NUT2), the results of which are analysed by municipal areas (LAU2) for the years 2005 and 2009.
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