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This paper aims at proposing a new delimitation of the morphological agglomeration of Valencia (Spain) using a method based on fractal geometry (MorphoLim) and comparing the obtained results with standard delineations. The urban agglomeration of Valencia is located on the Mediterranean coast and is experiencing a strong urban growth by spatial dispersion and by multiplication of building floors. The originality of this paper lies in the application of a method capable of taking into account the diffusion for several heights of buildings, which allows to take into account the specificities of Valencia. The introduction of the third dimension offers a new perspective in the morphological analysis of urban spaces.

As part of a broader multidisciplinary research project dealing with the association between health and green/blue environments, this paper aims at exploring the spatial variation of medication reimbursements within Belgium. These data were potentially and a priori considered as a proxy for health. This paper is purely exploratory: statistical maps, correlations, PCAs and cluster analyses corroborate the results. Five groups of medications prescribed for health disorders associated with the environment have been selected. We show that – at the level of the municipalities – the spatial distributions of the five medication groups are positively correlated to each other (medication consumption co-vary positively in space, whatever their type), but are independent of the environmental and socio-economic conditions measured. Against our expectation, they prove to be negatively correlated to air pollution and green spaces. Strikingly, the spatial distribution of medication prescriptions follows the linguistic border between Flanders and Wallonia. This implies that the observed differences are mainly due to administrative/political regional differences in terms of health policies, medical schools, pharmaceutical commercial activities, etc. that are hard to quantify (no data, diversity of actors) but should be taken into account in any further explanatory model. Medication reimbursements data correspond to a new type of data, and despite their potential attractiveness for health analyses, extreme care has to be taken when interpreting their spatial variation and their link to health.

This paper aims to compare the spatial distributions of road accidents involving a cyclist that are officially reported to the police with those not reported (user-sourced dataset). We show that reported and unreported cycling accidents have similar spatial patterns and exhibit similar locational tendencies with respect to specific infrastructures and facilities. We illustrate the importance of defining a study area in the interpretation of the (cross) K-function results and show that cycling accidents are more likely to be unreported in areas where a small speed difference between slow and fast modes is imposed (traffic-calming areas). Because safety measures influence both accident rate and reporting rate, evaluation of their effect on cycling accidents requires careful spatial analysis.

This paper assesses the usability of land prices as an indicator of the efficiency by which different delineations of a given city capture the influence area of that city. The case study used is Brussels (Belgium). A hedonic model of land prices (log-linear and semi-parametric specifications) is estimated for 12 different delineations of the city and on automatically constructed delineations. The assumption, grounded in the Alonso-Muth model, is that when local amenities have been controlled for, accessibility to the CBD parameter estimate will reflect the city influence on its delineation. Results show that both the size and composition of the delineations of Brussels influence the land price determinants. The size changes the spatial structure of land prices, which is best described by Hoyt’s sector model for narrow definitions of Brussels, and by Alonso-Muth type model for larger definitions. Composition induces variations in the magnitude of the influence of accessibility to the CBD on land prices, due to the presence of secondary centers or rural areas. The lack of detailed data on land prices limits the robustness of the results. Nevertheless, our findings show the potential of land prices as a tool for comparing delineations of a city, or to draw delineations of that city. Finally, they also suggest that delineations based on fluxes (e.g. commuting), and on endogenous thresholds, are more adequate to capture the influence area of a city than those based on transport infrastructure or administrative delineations.

Numerous cities are pursuing large urban projects in order to consolidate both their international reputation and their position in an increasing context of competition between cities. These complex projects involve a multitude of stakeholders; that is, groups or individuals that can affect or be affected by the objectives of the project, including public officers, investors, the civil society, professionals, etc. The comparative analysis of the organizational structure (the set of stakeholders and the relationships between them) and management mechanisms (strategic tools, tactical urban planning methods, tools for citizen participation) in two large urban projects – the Quartier des spectacles in Montreal (Canada) and Lyon Confluence (France) – shows how this structure and these mechanisms determine the level of influence of the different stakeholders on the project. Despite the fact that participation has contributed to informing citizens, building trust, and making decision, the study shows that in both cases, strategic decisions were taken by « urban elites » (Pinson, 2009). Although these « urban elites » are composed by a multiplicity of actors, public authorities in Lyon largely dominate the urban project, whereas in Montreal the project is dominated by both public and private urban elites. Finally, the study highlights the advantages and disadvantages of participation models proposed by S. Arnstein (1969) and UN-Habitat (2009).

This paper aims at showing how the estimations of individual shopping travel behavior depends upon the city. To this end, we use nested multinomial logit models with random coefficients, and apply them to shopping trips in four different Belgian cities (Aalst, Antwerpen, Mechelen and Gent). Results highly depend upon the studied city: spatial behavior is influenced by the size and morphology of the city. These results are quite important when starting a data collection step, which is often expensive and time consuming. Large samples are necessary, and one needs to be careful when generalizing from only one case study. Space matters.

Fractal dimension is used to measure the spatial arrangement (morphology) of built-up areas within a Nuts1 region (Wallonia, Belgium) and, more particularly, to test to what extent fractal dimension is related to some variables commonly used in urban economics/urban geography to characterise built environment, housings and residential choice (such as land price, housing rentals, history of urbanisation, type of housing). Special attention is put on the link with the perception of the built environment by households. A multivariate analysis concludes the paper. It is shown that fractal indices differ from other indicators and are very useful for characterizing and understanding built landscapes, as well as for modelling and planning urban realities.

This paper aims to show the usefulness of the optimal location-allocation models for planning health care facilities in a developing country. Several simulations are performed for one province of Rwanda (Kibungo) leading to quite interesting conclusions in terms of planning as well as operationality of the model. The outcomes of two planning hypotheses are evaluated: (i) massive changes in the location of population, and (ii) changes in the transportation conditions by an enhancement of the road network.

It has already widely been shown that the extension of the urban space takes a polycentric shape: suburban employment sub-centres emerge. The objective in this study is to measure employment concentrations inside and around urban agglomerations and to determine operational tools (methods and data) that lead to the highlighting of these sub-centers. Advantages and limits of the methods are discussed. Our cases studies are Antwerp and Brussels. The results obtained by several methodologies are compared (shift and share analysis, cluster analysis, kernel interpolation and local autocorrelation) for three different types of employment data (social security, population census and regional development statistics) and at three different scales of analysis (individual postal address, neighbourhood and commune). The main difficulties encountered are: (1) the spatial and temporal heterogeneity of the data, and (2) the non-uniqueness of the methodology for discriminating sub-centers. Our conclusion is that there is an emerging polycentric structure in Brussels and Antwerp, but sub-centers are still difficult to put forward. The combination of several different methods and databases is necessary to get insight in the polycentric structure.

The starting point for this article is the fact that each spatial object i is characterized by three coordinates: x (latitude), y (longitude) and z (by tradition elevation). The discussion is organized around three axes. First, the author reviews some of main problems encountered when representing a volume (ellipsoid) on a plane (map). Second, some elementary principles of cartography are discussed in order to demonstrate the importance of the nature of z in thematic mapping. Third and last, the author shows how the realistic representation of the third dimension can be improved by use of visualization techniques, a modern discipline that is close to but different from cartography.Keywords: mapping, visualization/visualisation, dimension

We start from the fact that each spatial object i is characterized by three coordinates: x (latitude), y (longitude) and z (by tradition elevation). The discussion proposed here turns around three axes: first, we remind some of the main problems when representing a volume (ellipsoid) on a plane (map). Second, we discuss some elementary principles of cartography in order to show the importance of the nature of z in thematic mapping. Third and last, we show how far the realistic representation of the third dimension can be improved by visualization techniques, a modern discipline close but different from cartography.

L'objectif du présent article est de poser succinctement les problèmes que soulèvent la caractérisation de la forme d'un réseau par un - ou plusieurs - paramètre(s). Une brève revue de la littérature est proposée; elle conduit à la conclusion qu'il n'existe pas aujourd'hui de critère unique et dépourvu d'ambiguïté permettant de distinguer deux graphes topologiquement distincts. Des perspectives sont discutées quant à la mesure de l'effet de la forme du réseau de communication sur les résultats d'un modèle de localisation optimale.