Bruit aérien et équité environnementale dans les quatre plus grandes métropoles canadiennes

Previous environmental equity studies have examined the spatial distribution of aircraft noise across cities. Their findings show that, in several cities, visible minorities and low-income populations are most affected by aircraft noise. In contrast, one study concludes that well-off populations are the most affected. These contradictory findings support the use of a comparative approach for several cities. The aim of this study is twofold. First, we want to identify if there are groups in the population that are in a situation of inequity to aircraft noise exposure in Toronto, Montréal, Vancouver, and Calgary. Then, we want to check if the exposure to the aircraft noise of the different groups varies significantly from one metropolis to another. We use the recommended noise exposure contour maps in Canada: the Noise Exposure Forecasts. Next, four variables are extracted from the 2016 Statistics Canada census at a fine-scale level (dissemination areas): that is, the percentages of low-income, visible minorities, 0- to 15-year-old, and 65-year-old and over populations. The results of a mixed effects logistic regression model show that environmental inequities in terms of exposure to aircraft noise for the four population groups are not consistent from city to city.     

Legacy databases and GIS: a discussion of the issues illustrated by a case study of archaeological site data from southeast Alberta,Canada

Many institutions and agencies are currently faced with the issue of geographic information systems‐enabling legacy databases. The problems can be acute for data sets that have been compiled through many years, using different standards and levels of recording. To explore these issues further, we report on a data quality assessment undertaken in 2002 for a subset of the archaeological site database of the province of Alberta, Canada. Our work shows that positional ambiguities in the data set can be highlighted and corrected by relatively straightforward procedures. This case study also provides an indication of the amount of work effort that will be involved in validating or ‘cleaning up’ data sets so model results and analyses undertaken with them are more reliable.     

La mobilité quotidienne de banlieusards vieillissants et âgés: Déplacements, aspirations et significations de la mobilité

Les premières banlieues pavillonnaires nord-américaines sont problématiques pour le vieillissement à domicile. Malgré la dépendance à l'automobile, les banlieusards âgés aspirent à y vieillir. Plutôt que de déménager, ils adaptent leur quotidien et leurs déplacements. L'accès à la mobilité est un enjeu majeur au maintien d'une expérience résidentielle positive, notamment pour les individus en perte d'autonomie. Or, parce qu'elle est étudiée avec le concept de déplacement, la mobilité des aînés demeure mal comprise en tant qu'expérience individuelle et collective. C'est dans cette optique que les pratiques et les significations de la mobilité quotidienne de 87 banlieusards âgés de 55 à 82 ans de l'agglomération de Québec au Canada sont ici étudiées. En croisant des méthodes quantitative et qualitative ainsi que des techniques d'analyses spatiales, l'article développe une typologie de mobilité pour explorer les stratégies d'adaptation des aînés à leur environnement socio-spatial. Les résultats montrent que, sans véritablement entrer dans un processus de décision, les banlieusards choisissent implicitement de vieillir en banlieue en adaptant de manière continue leurs modes de vie. La conservation de l'indépendance et l'attachement au «mode de vie banlieusard>> sont à la source des aspirations résidentielles. Cette mobilité quotidienne en transformation risque aussi d'influencer les trajectoires résidentielles, alimentant les réflexions sur la requalification de ces milieux vieillissants.     

Functional specialization across space: a case study of the Canadian Electricity Industry, 1971–2001

This article examines the location of functions within the electricity sector in Canada from 1971 to 2001, using a centre‐periphery model. Power generation, distribution and retailing are generally carried out by multiestablishment crown corporations. Location patterns of different functions—management, scientific, production, etc.—are analyzed via the use of occupational groups. The spatial distribution of functions is found to be generally consistent with centre‐periphery relationships, with evidence of a growing functional specialization between large metropolitan and nonmetropolitan locations. However, differences emerge depending on power generation sources: fossil fuels, hydro, nuclear, solar or biomass. The choice of a power generation source has consequences for local economies.     

丙烯酸非水分散体等几种土遗址防风化加固剂的效果比较

对丙烯酸树脂非水分散体等几种土遗址防风化加固剂进行了加固效果对比检验,包括加固前后土样各种性能的变化,如：重量、颜色、孔隙率变化,抗压强度的提高,耐水、耐冻融、耐盐能力的增加等。通过检验发现,在所试材料中丙烯酸树脂非水分散体加固刑在浓度非常低的情况下对土体就有加固作用,使土体具有很好的耐水性、耐冻触能力,耐盐破坏能力也有提高,并且不影响土体的外观和透气性。而其它材料如正硅酸乙酯、丙烯酸树脂、聚氨酯、聚酯等虽在一些性能上能满足需要,但还有一些方面不能满足要求。对比表明,丙烯酸非水分散体是一类优良的土遗址防风化加固剂。     

有机硅改性丙烯酸树脂非水分散体的制备及在土遗址保护中的试用

为找到耐候性良好并对土遗址有良好保护效果的材料,以工业品的有机硅改性丙烯酸树脂乳液为原料,采用转化法制备了有机硅改性丙烯酸树脂非水分散体材料。对形成的非水分散体进行了外观检验和老化性能检验。通过对土样的加固试验和实地应用发现,浓度为0.8％的加固剂251M具有良好的固结效果,表面颜色基本不变,证明这种材料是一种有应用前景的土遗址防风化加固保护材料。     

一体化条件下的空间经济集聚

空间经济集聚是经济地理学研究重点,并且渐渐被经济学所重视。本文以经济地理学的理论为基础,借鉴主流经济学的有关理论,探讨了区域经济一体化导致的空间经济集聚的机理,即经济集聚与经济扩散同时并存,空间上以经济集聚为主导,以扩散为辅;提出了经济集聚的本质是规模经济、范围经济和外部经济共同作用的过程。规模经济导致经济集聚产业点,再加上范围经济产生集聚产业区,规模经济、范围经济和外部经济共同作用产生经济集聚产业核心区。指出经济扩散的原因是纯粹的集聚不经济、区域分工共同作用的结果。     

Le Conte de deux cités1 : Analyse comparative des conflits urbains de Montréal et Valence, 1995–2010

A tale of two cities: 9 Comparative analysis of urban conflicts of Montreal and Valencia, 1995–2010 Metropolization processes at work in contemporary societies produce social and spatial change, which can raise strong opposition from a variety of urban actors, leading to acts of dissent. While such urban conflict has been examined in the past, geographical analysis of urban conflicts as sociospatial processes is more recent. Systematic quantitative research on urban conflict is virtually nonexistent in terms of comparative analysis conducted with an international perspective. Systematic comparative analysis sheds light on the existing relationship between urban conflicts and the socio‐territorial contexts in which conflicts emerge and evolve. This article presents a comparative analysis of urban conflict that occurred in a selection of boroughs in two cities characterized by different geographical realities, Valencia (Spain) and Montreal (Canada), between 1995 and 2010. Spatial autocorrelation techniques applied to a conflict database show a significant relationship between the emergence of urban conflict and the spatial distribution of some contextual variables. Indeed, for Montreal as for Valencia, the concentration of urban conflict is the greatest in the most deprived neighbourhoods. Also, regarding the management and regulation of urban conflict, results shed light on important differences between Montreal and Valencia. These differences include the outcome of urban conflicts, repertoire of action of actors involved in conflict activity, and the type of contestation faced by actors who promote the challenged urban projects.     

ARTIFICIAL ACCELEROGRAMS REPRESENTATIVE OF THE DAMAGE DISTRIBUTION ON A LOW-RISE SHEAR WALL

This study attempts to reproduce in an artificial way, at a given magnitude-distance couple, the statistical characteristics of damage caused by real accelerograms. The structure adopted is a low-rise shear wall, modelled as a nonlinear, one degree of freedom system with a degrading frequency as a function of a non-cumulative damage variable. Strong-motion records, contained in a large database, are characterised in terms of seismological and seismic parameters. Artificial accelerograms are generated from response spectra representative of real accelerograms belonging to different magnitude-distance zones. Although the mean damage is consistent, the low dispersion of damage caused by the artificial accelerograms with respect to that caused by the real accelerograms is highlighted. In order to reproduce the damage dispersion in addition to the mean damage, a generation method of representative artificial accelerograms is proposed. This method introduces the standard deviation drawn from attenuation relationships into a dispersion pre-process with respect to the regressed spectrum at a given magnitude-distance point. The method turns out to be capable of reproducing the statistical features of damage produced by real strong-motion records.