Carlos Ramiro Marmolejo Duarte

Urban Structure and Polycentrism: Towards a Redefinition of the Sub-centre Concept

This paper seeks to extend the definition of a sub-centre beyond the usual definition as a place with significantly larger employment density that has an effect on the overall employment density of the nearby locations. Together with the previous conditions, it is suggested that it is necessary to include another which represents a structural element of an urban sub-system within the metropolitan configuration—that is, a place with intense spatial interaction with its hinterland. Therefore, a metropolitan area can be seen as one comprising urban sub-systems characterised by greater or lesser polycentrism. In this paper, a ‘bottom—up’ methodology based on commuter flows is proposed in order to detect metropolitan sub-centres. Using empirical data from the Metropolitan Region of Barcelona, the proposed methodology is tested, comparing its results with those of other commonly used methodologies (cut-offs, parametric and non-parametric models). The results suggest that the proposed methodology permits optimising the sub-centre delimitation process.

Using GIS and Teledetection data to assess mobility and land consumption in polynucleated landscapes

Polycentrism has become the keystone in a major number of regional and urban policies, since it has been seen as a sustainable and equilibrated urban model. In this paper, the problem has been focused in case study the biggest metropolitan areas in Spain and pretends test whether polycentric urban growth does effectively reduce land consumption and travel-to-work journeys, protecting in this way agricultural and forest areas around cities and at the same time reducing energy and air emissions produced by cars. The methodology used has been departed from land-use, transport and census data, and using ArcGIS and TransCAD a group of spatial indicators is calculated and introduced in a family of regression models, where explained variables are per capita land consumption and excess commuting respectively. The results suggest that polynucleation has little effect both in the reduction of land consumption and excess commuting. On the contrary, other variables associated to urban form do highly influence land and mobility patterns, such as fragmentation of urban fabrics, job ratio balance, and the diversity of economic activities and housing offer. Such conclusions may shed light in the design of urban policies, and focus the attention on the definition of small-scale urban variables instead of structural ones at metropolitan scale.

El valor de las ciudades como espacios de concentración de la nueva economía basada en el conocimiento: un análisis para la región metropolitana de Barcelona

Las ciudades ademas de ser centros de interaccion social y economica, tienen unos atributos urbanos y arquitectonicos inherentes que las hacen atractivas para la concentracion de personas y actividades economicas diversas. En este articulo se estudia para la Region Metropolitana de Barcelona como la proximidad fisica a los centros urbanos de mayor jerarquia constituye un elemento determinante para el crecimiento del empleo en los sectores economicos intensivos en conocimiento. Se estudian por ello los factores que estan explicando la densidad y los cambios en la concentracion del empleo en el periodo 1991-2001 en las areas de funcionalidad economica de la Region. Los resultados muestran que es fundamentalmente la distancia al centro metropolitano el factor determinante del crecimiento de estos sectores economicos por los beneficios que la aglomeracion y la proximidad geografica tienen para su desempeno.

Revisión de la densidad de empleo como medio para detectar sub-centros metropolitanos: un análisis para Barcelona y Madrid

Polycentrism is seen as a desirable model of metropolitan structure. The starting point in its study rests upon the conceptualisation and identification of subcentres. The hegemonic family of subcentre identification is based on the analysis of density. Huge efforts have been devoted to achieving statistically robust models, but little attention has been paid to the conceptualisation of density itself. This paper presents a different approach to calculating density through the introduction of basic elements of mobility and placing priority on subcentres as those municipalities that are closer to the urban paradigm of central cities in southern Europe they are attractive both for living and working. The analysis in Barcelona and Madrid suggests that compound density allows for selecting what local experts would define as a subcentre, discarding most dormitory, djacent to CBDs and small municipalities, found by classical density. Furthermore compound density sub centres are denser, they contain more central activities and are strongly linked to other municipalities.

Editorial sobre la Sección Especial monográfica "Modelo de evaluación de la eficiencia energética y ambiental, de la movilidad y la estructura de usos del suelo, para la Región Metropolitana de Barcelona"

Portada, indice y editorial de la Seccion Especial “Modelo de evaluacion de la eficiencia energetica y ambiental, de la movilidad y la estructura de usos del suelo, para la Region Metropolitana de Barcelona”, proyecto financiado por el Ministerio de Fomento, Convocatoria 2008 de ayudas y proyectos de I+D+I de la Accion Estrategica y Cambio Climatico, Subprograma para la movilidad sostenible y el cambio modal en el transporte E 8/08

Revisiting employment density as a way to detect metropolitan subcentres: an analysis for Barcelona & Madrid.

Polycentrism is seen as a desirable model of metropolitan structure. The starting point in its study rests upon the conceptualisation and identification of subcentres. The hegemonic family of subcentre identification is based on the analysis of density. Huge efforts have been devoted to achieving statistically robust models, but little attention has been paid to the conceptualisation of density itself. This paper presents a different approach to calculating density through the introduction of basic elements of mobility and placing priority on subcentres as those municipalities that are closer to the urban paradigm of central cities in southern Europe they are attractive both for living and working. The analysis in Barcelona and Madrid suggests that compound density allows for selecting what local experts would define as a subcentre, discarding most dormitory, djacent to CBDs and small municipalities, found by classical density. Furthermore compound density sub centres are denser, they contain more central activities and are strongly linked to other municipalities.

DO HIGH-RISE APARTMENT CONDOS EQUALLY REVALUE THE NEIGHBORING HOUSING? AN ANALYSIS OF —U—OA, SANTIAGO DE CHILE

Many studies have analyzed the market premium enjoyed by houses located within gated communities; nevertheless little or no attention has been paid on the impact that such a sort of development produces on the surrounding housing market. This question becomes very important in the cities in which gated communities or other common interest communities, aimed to medium and high socioeconomic groups, are traditionally confined to low incomes enclaves. Salcedo & Torres (2004) and Caceres & Sabatini (2004), from a qualitative perspective, have suggested that this social proximity produces various benefits like improvement of value expectations of land from the original settlers, among others.