High levels of mobility have given rise to land-use patterns that are difficult to navigate for nonmotorised transport users. Fragmentation in a transport system can be considered as a lack of connectivity (or permeability), as infrastructures reduce the connectivity between places. Fragmentation has been extensively studied in landscape ecology, and can be understood as a loss of connectivity. Connectivity is defined as the degree of permissiveness offered by the landscape for the displacement of organisms, energy flows and dispersive movements. This article presents a map of urban fragmentation for pedestrians using a habitat fragmentation indicator. It represents difficulty for pedestrian mobility as a function the of the accumulative cost distance over a cost surface under the current motor traffic-oriented street/mobility layout. The map is developed for the Chamberí district in Madrid (Spain). The process consists of first developing the resistance matrix of the territory database. The resistance value is the time taken to travel through the streets. The street axis network is converted into pavements, as this is the part of the street used by pedestrians, including pedestrian crossings and traffic lights. The resistance value -travel time -is calculated, including waiting time. Once the resistance matrix has been created, GIS functions are used to calculate the least accumulative cost distance for each origin to a set of attractive locations/destinations for pedestrians.

RESUMENHoy en día es necesario reconciliar el desarrollo urbano con el equilibrio ecológico y adoptar un urbanismo con base territorial amplia, para controlar la localización y regulación de los usos y actividades. Dentro de este contexto, el trabajo que se expone en el presente artículo, se planteó como objetivo último la localización de nuevas áreas urbanas de baja densidad en el entorno del Corredor del Henares de Guadalajara (España). Los modelos de capacidad e impacto diseñados al efecto consideran como uno de sus componentes más importantes la calidad visual del paisaje, que se basa, a su vez, en un estudio exhaustivo de la visibilidad del territorio. El objeto de los análisis de visibilidad es determinar las áreas visibles desde cada punto o conjunto de puntos, bien simultáneamente o en secuencia, con vistas a la posterior evaluación de la medida en que cada área contribuye a la percepción del paisaje y a la obtención de ciertos parámetros globales que permitan caracterizar un territorio en términos visuales. Siguiendo la línea enunciada, el trabajo trata de realizar una aportación en el campo de los estudios de visibilidad, mediante el diseño de un modelo de visibilidad, posteriormente programado e implementado en SIG (Sistemas de Información Geográfica); se describe el proceso seguido para realizar esta tarea, centrándose en las dificultadas que se presentaron y su resolución. El análisis de visibilidad desarrollado constituyó un punto importante tanto en el modelo de capacidad de acogida de la actividad como en el modelo del impacto que ésta puede producir en el medio. La construcción de un modelo de visibilidad permite valorar de forma objetiva la visibilidad del territorio desde todos los puntos de interés.(*) Universidad Politécnica de Madrid (Madrid, España) Persona de contacto/Corresponding author: isabel.otero@upm.es (I. Otero) SUMMARY Nowadays there is a need to take account of the ecological balance in urban development, and to adopt a type of urban planning which is spread over a broad territorial base in order to control the localisation and regulation of uses and activities. In view of this requirement, the objective of the work described in the present article is to propose locations for nine low-density urban areas in the surroundings of the Corredor del Henares in Guadalajara (Spain

Recent increases in incidents make it unlikely for emergency systems to be able to meet incident requirements. In this paper, we formulate a new territorial measurement approach for the reliability of fire departments, the collapse index, to help decision makers determine their response capability. This new index expresses the maximum simultaneous workload in a pixel over one year, measured over time. Based on this index, we propose a new fire station (FS) optimum location model by applying the simulated annealing method in conjunction with a geographic information system. The formulation of the cost function as the minimum standard deviation of the FS workload, combined with the constraint that the maximum collapse index in any pixel must be less than a certain threshold, are two contributions of this work. Five optimisation processes are developed to locate between up to five FS and create collapse index maps in the Madrid Region. The maximum collapse index in a pixel with a new FS decreases from its initial value of 10,485 min to 2500 min when five new FS are built. The conclusion is that the proposed optimisation model meets the need for reliability in the emergency services and that the collapse index is a good measure to prevent overlapping in the system.

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