AGGREGATION ERROR EFFECTS ON THE DISCRETE-SPACE p-MEDIAN MODEL: THE CASE OF EDMONTON, CANADA

The spatial analysis literature recognizes three sources of aggregation error, termed Source A, Source B, and Source C, which affect models relying on distance measurements between populations and facilities. We consider these effects with respect to aggregating from census enumeration areas to census tracts, on a popular location model. We identify a further source of aggregation error, which we dub Source D error, arising from the representation of facility sites by discrete points. Source D effects are of the same magnitude as Source A and B combined, much greater than Source C effects. Source D error is further significant, because, unlike Source A and B error, it can be eliminated only by disaggregating .
La littérature sur Vanalyse spatiale reconnaît trois sources d'erreur d'agrégation appelées erreurs de source A, B, et C. Ces erreurs influencent les modèles qui reposent sur des mesures de distance entre des populations et des installations. On considère les effets d'agrégation des secteurs de dénombrement en secteurs de recensement sur un modèle de localisation courant. On identifie une quatrième source d'erreur d'agrégation appelée erreur de source D. Cette erreur découle de la représentation des sites des installations par des points discrets. Ses effets sont du même ordre de grandeur que ceux des sources A et B combinées et beaucoup plus grands que les effets de source G. L'erreur de source D est d'autant plus significative à cause du fait que, contrairement aux erreurs de source A et B, elle ne peut être éliminée que par la désagrégation .     

Boats and Boatbuilding in Tanzania (Dar‐es‐Salaam and Zanzibar)

A wide variety of traditional wooden boats and small ships can still be seen in use and being built on the mainland of Tanzania and the island of Zanzibar. This paper compares different accounts in the literature with observations made in 2012, and documents in detail the various stages of building wooden dhows on the beaches of Zanzibar.     

RECENT ENVIRONMENTAL CHANGE IN THE SOUTHWESTERN CANADIAN PLAINS

This paper examines 20th-century environmental change in the subhumid southwestern Canadian Plains, specifically in relation to the dominant agricultural landscape and to the climate of the past millennium as reconstructed from proxy data. Anthropogenic landscape change in the last century has been dominated by the conversion of grasslands to ranchland and cropland. This has heightened landscape vulnerability to climatic fluctuations, especially drought. Instrumental climate records, extending back to the 1880s, highlight the variability of precipitation in this region. Proxy environmental records, derived from lake cores and tree-ring analysis, extend this picture into the last millennium and show that drought has been a recurring theme of the Prairie climate. Tree-ring records suggest that some droughts in the last millennium may have exceeded in severity any in the instrumental record. The sustainability of Prairie agriculture depends on adaptation to the amplitudes of climatic change and variability evident in these proxy records. Dans cet article nous examinons les changements environnementaux qui sont survenus pendant le 20^ème siècle dans les plaines canadiennes sèches du sud-ouest, spécifiquement par rapport au paysage agricole dominant et au climat du dernier millénaire qui a été déterminéà partir de données de procuration. La transformation des prairies en ranchland et cropland est le changement du paysage le plus important dont l'homme est responsable, pour le dernier siècle. À cause de ce changement, le paysage est plus vulnérable aux fluctuations climatiques - à la sécheresse en particulier. Les enregistrements instrumentaux de climat, qui reculent jusqu'aux années 1880, mettent en évidence la variabilité des précipitations dans cette région. Les enregistrements environnementaux de procuration, dérivés d'échantillons pris dans les lacs et de la dendroanalyse, étendent cette image dans le dernier millénaire et prouvent que le thème de la sécheresse est apparu souvent dans les analyses du climat du prairie. Les enregistrements de boucles d'arbre suggèrent que, dans le dernier millénaire il y avait des sécheresses qui étaient peut-être si sévères que les instruments n'ont pas pu les enregistrer. Si l'agriculture veut survivre comme entreprise dans les prairies, il faudra qu'elle s'adapte aux amplitudes de changement et de variabilité du climat qui ont été constatées dans les données de procuration.     

Revamping community‐based conservation through participatory research

Community‐based conservation is experiencing a crisis of identity and purpose as a result of a disappointing track record and unresolved deficiencies. The latter include over‐simplified assumptions and misconceptions of “community,” the imposition of externally designed and driven projects at the community level, a focus on conservation outcomes at the expense of community empowerment and social justice, and limited attention to participatory processes. New approaches are urgently needed to address these weaknesses and to counter a rising trend towards environmental protectionism and a preference for conservation approaches at an eco‐regional scale that threaten the interests of local and Indigenous communities. We propose that three core principles of community‐based participatory research (CBPR)—(1) community‐defined research agenda; (2) collaborative research process; and (3) meaningful research outcomes—hold much promise. Drawing on the experience of a research partnership involving the James Bay Cree community of Wemindji, northern Quebec, and academic researchers from four Canadian universities, we document the process of applying these principles to a community‐based conservation project that uses protected areas as a political strategy to redefine relations with governments in terms of a shared responsibility to care for land and sea. We suggest that basic assumptions of CBPR, including collaborative, equitable partnerships in all phases of the research, promotion of co‐learning and capacity building among all partners, emphasis on local relevance, and commitment to long‐term engagement, can provide the basis for a revamped phase of community‐based conservation that supports environmental protection while strengthening local institutions, building capacity, and contributing to cultural survival.     

The state of climate change adaptation in Canada's protected areas sector

L’adaptation aux changements climatiques dans les réseaux d’aires protégées du Canada : état des lieux La Commission mondiale des aires protégées a récemment laissé entendre que les actions en faveur de la conservation sont vouées à l’échec, à moins que ces dernières tiennent compte des changements climatiques. Pour ce faire, les organismes chargés des aires protégées doivent dès maintenant s’assurer de l’intégration des changements climatiques dans les politiques, les cadres de planification et les modes de gestion. Le présent article rend compte des résultats d’une enquête réalisée conjointement par l’Université de Waterloo et le Conseil canadien des aires écologiques. Celle‐ci vise à dresser un état des lieux sur l’adaptation aux changements climatiques dans tout le réseau d’aires protégées du Canada qui relève du palier fédéral, provincial ou territorial. Il se dégage de l’analyse plusieurs constats importants. Tout d’abord, sur l’ensemble des organismes chargés des aires protégées que nous avons interrogés, les trois quarts ont déclaré que les changements climatiques ont déjà des effets visibles sur leur réseau d’aires protégées. Ensuite, 94 pour cent des participants à l’enquête estiment qu’au cours des vingt‐cinq prochaines années, l’enjeu des changements climatiques sera au c?ur de la politique et de la planification des aires protégées. Finalement, malgré la perception voulant que les changements climatiques exercent une pression croissante, la portée des mesures politiques, de planification, de gestion ou de recherche mises de l’avant par la plupart des organismes jusqu’à maintenant demeure limitée. Si 91 pour cent des organismes indiquent ne pas disposer des capacités nécessaires en ce moment pour réagir de façon optimale aux changements climatiques, l’enquête a permis de mettre en évidence un écart significatif entre la perception de la gravité des changements climatiques et la capacité des organismes chargés des aires protégées de s’adapter. La faiblesse du financement, une capacité d’action limitée, et un manque de compréhension des changements climatiques et de leurs répercussions réelles ou potentielles comptent parmi les difficultés auxquelles sont confrontés les organismes canadiens chargés des aires protégées. Il est impératif de les surmonter afin que ces organismes puissent exercer leurs mandats et être en mesure d’assumer leurs responsabilités concernant la protection et la biodiversité des aires, par exemple, la protection de l’intégrité du patrimoine naturel au Canada dans un contexte de changements climatiques accélérés.     

Detrended fluctuation analysis of daily atmospheric surface temperature records in Atlantic Canada

The presence and properties of long‐range correlations in temperature data reflect interactions among climate components; therefore, the quantitative characterization of scaling aspects of temperature patterns is important to climate research and can serve as an effective constituent of tests for climate models. The article presents the results of a study using multiscale characterization of daily atmospheric surface temperature patterns in Atlantic Canada. Important influences in this region are exerted from the west (the Pacific Ocean), the south (the Gulf of Mexico) and the north (the Arctic), while a significant easterly impact is due to the Atlantic Ocean; the corresponding processes involve a wide range of spatial and temporal scales. The objective of the present study of long‐term temperature recordings was to evaluate the scaling properties produced in this geographical context. The data consist of homogenized daily atmospheric temperature time series recorded in stations from Atlantic Canada over a time interval of more than 100 years. Detrended fluctuation analysis (DFA) was applied both to maximum and minimum temperature records. The atmospheric temperature pattern produced by the interplay of factors of different strengths and dominating various time‐space scales was found to be characterized by consistent scaling properties, expressed over time intervals ranging from months to decades. Higher values of DFA scaling exponents were obtained for minimum temperature compared to maximum temperature records. Site‐specific properties include stronger pattern persistence—higher DFA exponents—for oceanic than for coastal locations; persistence tends to decrease with increasing distance from the coast for distances up to 10 kilometres. Scaling exponents tend to increase with decreasing difference between average minimum and maximum temperature, which may be relevant for the assessment of future changes in pattern variability if climate change involves modified contrasts between minimum and maximum temperature values.     

Mental maps,segregation, and everyday life in Dar es Salaam,Tanzania

Dar es Salaam, Tanzania, has a long history as a segregated city. Starting in 1891 the German and then later the British colonial government enacted a series of building ordinances that outlined the styles of construction allowed within different areas of the city. Although these policies applied only to the structures themselves, ultimately they served to divide the city into European/Expatriate, Asian, and African areas. In spite of official attempts to integrate the city, postcolonial Dar es Salaam remains a racially segregated place. This segregation extends beyond residence location and affects all aspects of everyday life such as shopping and recreation. This article uses mental maps drawn by some of Dar es Salaam's residents to illustrate the lingering effects of colonial segregation on the knowledge, perception, and experiences residents have in and of today's city. Expatriate, Asian, and African maps include vastly different locations within the city. Those places considered important enough to map demonstrate that colonialism has continued impacts on the spaces and realities of everyday life in contemporary Dar es Salaam.     

The Secret History of TANU: Rumor,Historiography and Muslim Unrest in Contemporary Dar Es Salaam

This article explores historical rumors and narratives told by Muslims of Dar es Salaam, contending that Julius Nyerere, TANU founder and first president of independent Tanzania, was an inexperienced schoolteacher thrust into the role of political activist through sponsorship of the Muslim community. This history was allegedly hidden by the current government to cover up not only Nyerere’s meteoric rise to a position of leadership, but also subsequent actions that wrested the movement from Muslims and other early TANU leaders to monopolize power for himself and upcountry elites. Just as academic historians critique the teleological trajectory of many nationalist histories, these rumors critique Tanzanian nationalist history through appropriating its historiographic form to forefront postcolonial grievances. The discursive nature of such rumors articulates the discontent permeating the postcolonial Muslim community of Dar es Salaam. And as political speech in action, rumors are instrumental in mobilizing new postcolonial political configurations.