Comment structurer le problème de l'étalement urbain? : une approche concertée pour représenter la complexité territoriale

Enjeu majeur de la planification métropolitaine, la gestion de l’étalement urbain soulève le défi de saisir un phénomène complexe dans son ensemble. Cette complexité renvoie à la difficulté de proposer une représentation d’un problème toujours spécifique à un territoire, et perçu différemment par un ensemble varié d’acteurs. Les approches méthodologiques d’aide au diagnostic comme la méthode de cartographie cognitive de groupe semble adéquate pour faire émerger une représentation partagée des mécanismes explicatifs d’un phénomène, mais son utilisation invite à s’interroger sur la crédibilité scientifique des résultats obtenus. Une expérience de cartographie de groupe a d’abord été testée in situ puis évaluée de façon réflexive entre 2006 et 2007. Les recommandations proposées pour manipuler la complexité territoriale et accompagner le débat ont joué un rôle décisif sur un processus de concertation des acteurs de l’étalement urbain dans la région de Québec. Celui-ci a débuté par une analyse de la presse écrite publiée entre 2006 et 2009 afin d’explorer les représentations des acteurs ainsi que leur interaction potentielle. Un forum de discussion a ensuite été organisé sur une journée en 2009. Une trentaine d’acteurs ont ainsi négocié une représentation partagée des enjeux de l’étalement, de ses principaux mécanismes et des interventions qui devraient être priorisées. Les résultats de ce forum, soit un ensemble de cartes cognitives et leur négociation, sont enfin analysés en appliquant notamment la théorie des graphes. On observe ainsi que l’étalement urbain émerge de mécanismes territoriaux complexes et tortueux. Les représentations produites révèlent des contradictions entre les effets recherchés et subis de l’étalement, mais aussi les enjeux individuels et collectifs difficiles à concilier. Toutefois, les acteurs de Québec ont des représentations plus complémentaires que contradictoires et un modèle consensuel est mis en évidence. Ce modèle, rigoureusement comparé à la littérature scientifique récente et la plus citée sur l’étalement urbain en Amérique du nord, renforce à la fois sa crédibilité et sa spécificité. L’importance d’évaluer les représentations partagées construites lors de processus de concertation est ainsi démontrée, ce qui conduit finalement à proposer une approche générale pour manipuler la complexité territoriale, utile aux outils d’aide au diagnostic.Managing urban sprawl at a metropolitan scale challenges planners to comprehend a complex phenomenon holistically. The complexity comes from the difficulty of building a shared understanding of a problem that is always specific to a particular territory, but which is subject to a range of perceptions among a varied set of stakeholders. Current decision-support tools such as group cognitive mapping are increasingly used to diagnose complex and fuzzy problems, and promise to help develop a shared appreciation of concepts and explanatory mechanisms. However the results obtained often remain questionable in terms of scientific credibility. A preliminary trial of group cognitive mapping was implemented in situ and assessed reflexively between 2006 and 2007. Recommendations for improving the handling of territorial complexity, and for supporting the debate among stakeholders, led to further investigation into how best to consult those with an interest in urban sprawl. An analysis of written press coverage, published between 2006 and 2009, was used to explore stakeholders’ representations, and the potential for networking and interaction between stakeholders. Then, a one-day forum, held in 2009, was organized around twelve discussion groups. This allowed about thirty stakeholders with very diverse roles in the Quebec City metropolitan area to negotiate a shared understanding of sprawl, including the main issues, the explanatory mechanisms, and the priority interventions that should be considered. The result of the forum, expressed as a series of group cognitive maps, and summaries of the negotiation processes that led to them, was then analysed using methods based to a large extent on graph theory. From this we can observe that urban sprawl seems to emerge from complex and tortuous mechanisms, underlying contradictions between desired effects and their counterparts, as well as between individual and collective interests that are hard to reconcile. However, once surfaced, the stakeholders’ representations were more complementary than contradictory, and as a result it was possible to reach a consensus on a shared conceptual model. In the final stage of this research, the group model was rigorously compared to recent and most-cited scientific literature in North America, confirming both its scientific credibility and its applicability. The results thus reveal the relevance of assessing group models built interactively during the consultation process, and this leads to a proposed general approach for handling territorial complexity as a cornerstone of decision-support tools for the diagnosis of urban problems

Understanding the role of contrasting urban contexts in healthy aging: an international cohort study using wearable sensor devices (the CURHA study protocol).

BACKGROUND: Given the challenges of aging populations, calls have been issued for more sustainable urban re-development and implementation of local solutions to address global environmental and healthy aging issues. However, few studies have considered older adults' daily mobility to better understand how local built and social environments may contribute to healthy aging. Meanwhile, wearable sensors and interactive map-based applications offer novel means for gathering information on people's mobility, levels of physical activity, or social network structure. Combining such data with classical questionnaires on well-being, physical activity, perceived environments and qualitative assessment of experience of places opens new opportunities to assess the complex interplay between individuals and environments. In line with current gaps and novel analytical capabilities, this research proposes an international research agenda to collect and analyse detailed data on daily mobility, social networks and health outcomes among older adults using interactive web-based questionnaires and wearable sensors. METHODS/DESIGN: Our study resorts to a battery of innovative data collection methods including use of a novel multisensor device for collection of location and physical activity, interactive map-based questionnaires on regular destinations and social networks, and qualitative assessment of experience of places. This rich data will allow advanced quantitative and qualitative analyses in the aim to disentangle the complex people-environment interactions linking urban local contexts to healthy aging, with a focus on active living, social networks and participation, and well-being. DISCUSSION: This project will generate evidence about what characteristics of urban environments relate to active mobility, social participation, and well-being, three important dimensions of healthy aging. It also sets the basis for an international research agenda on built environment and healthy aging based on a shared and comprehensive data collection protocol