Andrea De Montis

The structure of interurban traffic: a weighted network analysis

We study the structure of the network representing the interurban commuting traffic of the Sardinia region, Italy, which amounts to 375 municipalities and 1600 000 inhabitants. We use a weighted network representation in which vertices correspond to towns and the edges correspond to the actual commuting flows among those towns. We characterize quantitatively both the topological and weighted properties of the resulting network. Interestingly, the statistical properties of the commuting traffic exhibit complex features and nontrivial relations with the underlying topology. We characterize quantitatively the traffic backbone among large cities and we give evidence for a very high heterogeneity of the commuter flows around large cities. We also discuss the interplay between the topological and dynamical properties of the network as well as their relation with sociodemographic variables such as population and monthly income. This analysis may be useful at various stages in environmental planning and provides analytical tools for a wide spectrum of applications ranging from impact evaluation to decision making and planning support.

Recent advances and applications in accessibility modelling

Accessibility is a concept that has become central to physical planning and spatial modelling for more than fifty years. As measure of the relative nearness or proximity of one place and persons to all other places or persons, conceptually linked to Newtons law of gravity, its origins can be traced back to the 1920s when it was used in location theory and regional economic planning (Batty, 2009) and retail planning (Stewart, 1948). In his classic paper, Hansen (1959) was the first to define accessibility as a potential of opportunities for interaction and applied the concept to forecast employment developments in Washington D.C. Hansens gravity-based measure of accessibility was a generalization of the concept of population potential, which was based on the notion of potential in physics systems by Stewart (1948). Since then, accessibility analyses have addressed the issue of spatial interaction. Spatial Interaction Models (SIMs) provide an explicit link between accessibility modelling, and economic, demographic and transport flows. SIMs have a long history and have been used in a wide variety of contexts. Wilson (1970) gave SIMs theoretical strength by deriving them using the entropy maximization approach, and the doubly-constrained form formed the bases for transport flow modelling. The formal equivalence between SIMs and logit models/micro-economic theory was shown by Anas (1983). The accessibility function can be directly derived from SIMs and it therefore contains SIM behavioural cost components ( Reggiani, 2014). Moreover, the relevance of topological/connectivity structures in the accessibility analyses has, in some way, been anticipated by Weibull (1980), who considered accessibility as a property of configuration of opportunities for spatial interaction. Accessibility models have in the past decades been applied in several academic fields such as urban geography, rural geography, health geography, time geography, spatial economics and transport engineering. Many different applications have been developed in these fields and can be categorized in several ways. Here, we use the categorization of accessibility measures from the well-cited review paper from Geurs and Van Wee (2004). They provide an overview of components of accessibility and perspectives on accessibility, which we will use as a categorization of accessibility measures. Geurs and Van Wee distinguish four basic perspectives on accessibility: (i) infrastructure-based measures, analyzing the performance or service level of transport infrastructure, (ii) location-based measures, analyzing accessibility of spatially distributed activities, typically on an aggregate level, (iii) person-based measures, founded in the space-time geography, analyzing accessibility at the level of the individual level, and (iv) utility-based measures, analyzing the welfare benefits that people derive from levels of access to the spatially distributed activities. These perspectives focus on one or several of the four components of accessibility distinguished by Geurs and Van Wee: (i) the land-use component reflecting the amount, quality and spatial distribution of opportunities, (ii) the transportation component describing the disutility of travel in terms of time, cost and effort, (iii) the temporal component reflecting the temporal constraints and variability, and (iv) the individual component reflecting the needs, and abilities of individuals. Here, we describe the directions which academic literature in the recent years took to improve the treatment of the four components in accessibility modelling.... Language: en

Accessibility and rurality indicators for regional development

Abstract The development of a region is affected, inter alia, by concepts linked to the ability to displace and reach other locations (accessibility) efficiently and to lagging economic conditions connected to contemporary countryside activities (rurality). These topics and their relationships have attracted the interest of scholars who have scrutinized the implications of accessibility and rurality for policy making and planning. The aim of this paper is to contribute to the theoretical modeling of accessibility and rurality and to develop an empirical study of their spatial patterns, with reference to the municipalities of the region of Sardinia, Italy. We study accessibility through an indicator constructed using a doubly constrained spatial interaction model and propose the Composite Index of Rurality that aims to evaluate rurality in a regional setting employing multivariate analysis. We investigate the spatial dependence of these indicators through general and local spatial autocorrelation analysis to verify the hypothesis that scarcely accessible spatial units are classifiable as rural areas. The results show that, for the case study of Sardinia, this hypothesis is not always true, as some urban areas are not always highly accessible.

Time Evolution of Complex Networks: Commuting Systems in Insular Italy

The aim of this paper is to study the dynamics of the commuting system of two insular regions of Italy, Sardinia and Sicily, inspected as complex networks. The authors refer to a 20-year time period and take into account three census data sets about the work and study-driven inter-municipal origin-destination movements of residential inhabitants in 1981, 1991 and 2001. Since it is likely that the number of municipalities (in this case, the vertices of the system) does not display sharp variations, the authors direct the study to the variation of the properties emerging through both a topological and a weighted network representation of commuting in the time periods indicated.

Measuring the performance of planning: the conformance of Italian landscape planning practices with the European Landscape Convention

ABSTRACT The assessment of the performance of planning is debated. The evaluation of the conformance of a given national planning system with a set of principles is similarly received with critical and favourable remarks. A relevant case study consists of the conformance of European landscape planning practice with the principles of the European Landscape Convention (ELC). Italy incorporated in 2004 the principles of the ELC with the Code on Cultural Assets and Landscape (CL), which opened the way for new laws, tools, observatories and atlases. The aim of this article is to demonstrate the usefulness of an assessment exercise concerning the conformance with the ELC of planning practice in Italy. We scrutinize planning systems and tools established by peripheral administrations, according to a qualitative and comparative framework. We refine our analysis by focusing on 10 most recent cases and identifying critical issues in current landscape planning practice. The results are promising and show that landscape planning in Italy is increasingly in line with the ELC.ABSTRACTThe assessment of the performance of planning is debated. The evaluation of the conformance of a given national planning system with a set of principles is similarly received with critical and favourable remarks. A relevant case study consists of the conformance of European landscape planning practice with the principles of the European Landscape Convention (ELC). Italy incorporated in 2004 the principles of the ELC with the Code on Cultural Assets and Landscape (CL), which opened the way for new laws, tools, observatories and atlases. The aim of this article is to demonstrate the usefulness of an assessment exercise concerning the conformance with the ELC of planning practice in Italy. We scrutinize planning systems and tools established by peripheral administrations, according to a qualitative and comparative framework. We refine our analysis by focusing on 10 most recent cases and identifying critical issues in current landscape planning practice. The results are promising and show that landsca...

PSS design: a general framework perspective

The paper presents a tentative framework for Planning Support System (PSS) design. The aim is to aid planners to fully exploit the potential offered by the introduction of Spatial Information Technology into planning practice. The framework proposed is based on a taxonomy of PSSs, which offers different conceptual models useful to adapt a general PSS model to different planning processes. The taxonomy is intended to set the application domain on which planners and developers may enhance the dialogue in system requirements analysis. A case study is proposed to illustrate the framework application and a perspective for further research development is given.

Multicriteria Evaluation and Local Environmental Planning for Sustainable Tourism

Within the framework of the certification for the environmental management system (EMS) and its total quality (i.e. ISO 14001 and VISION 2000), methodologies and research focus on innovative models for sustainable and environmentally-sound tourism. The complexity of these concepts requires the assessment of analytical schemes able to tackle conflicting situations and the subjectivity of political decisions. Thus, this paper provides insights into decision-making for a hypothetical institutional body interested in developing an objective standardized procedure for evaluating the spatial dimension of sustainable tourist development. The methodology assessed belongs to the family of multicriteria tools and is developed by the integration of the Regime method (Hinloopen and Nijkamp, 1990) with the AHP method (Saaty, 1988). The high volatility of the results is studied by means of sensitivity analysis and this leads to further reflections on the requirements of an Internet-based evaluation and learning process, grounded in a remote access debate among the stakeholders.

Complex Networks Analysis of Commuting

The emerging new science of networks is providing an elegant paradigm for the characterization of the broad area of complex systems. New research perspectives have been opened in the study of many real phenomena and processes, and recently fields like urban, regional, and environmental sciences have gained new insights from the tools provided by network science. The complex networks analysis (CNA) becomes a useful framework in these fields to disentangle problems of a complex and unpredictable nature.

Contingent Valuation of renewable energy innovations: vegetal biomass in Italy

Warming-up of the planet and scarcity of conventional energy resources has led to aim of reducing the consumption of fossil fuels and the development of innovative renewable technologies for energy production. However, innovations and investments in renewable energy can encounter resistance of local communities. This makes planning for the development of Renewable Energy Source-based power plants often very difficult. Against this background, we investigate the level of social consensus on and support of the development of an energy plant based on the use of vegetal biomass in Central Sardinia, Italy. The method adopted is Contingent Valuation. Estimates of ex-ante household Willingness To Pay are implemented, as they are important indicators of the social endorsement for the project development. Implications concerning consensus/disagreement on innovative technologies for sustainable energy production are discussed as perspectives of future research.

Recent Developments of Complex Network Analysis in Spatial Planning

In the last years, we acknowledge a great scientific interest on complex network analysis, a method able to characterise systems with very large numbers of entities (the nodes or vertices) interlaced by a series of connections/relationships (the links or edges). The objects of analyses as such are biological (predator-pray); information (internet); social (actor-in the same movie); transportation (railway and road networks) systems. While in general a network is an abstract (topo) logical object, spatial networks belong to an important class of systems that includes nodes and edges with a clear reference to space. Recently the interest of scientists has focused on methods able to define and investigate on communities emerging from the structure of a network. In this respect the spatial factor can emerge both as the result of the topological community structure that maps back onto geography in the form of sensible spatial regions, or just as spatial clusterisation of nodes in principle embedded in space. In this essay, the authors aim at presenting a state of the art summary of the last advances in the field of network community detection methodologies with a detailed view to the case of spatial networks. Secondly, the paper will report on a case study concerning a major issue for policy makers and planners: the delimitation of sub-regional domains showing a sufficient level of homogeneity with respect to some specific territorial features. We compare some intermediate body partitions of the island of Sardinia (Italy) with the patterns of the communities of workers and students, by applying grouping methodologies based on the characterisation of the Sardinian commuters’ system as a complex weighted network.