This paper investigates three techniques that are commonly used to generate estimates of base cation (BC) weathering rates, i.e. the profile mass balance (PEDON), the watershed input-output budget ...(WATERSHED) and the PROFILE model (MODEL). These methods were compared for their relative performance in estimating BC weathering rates for 21 watersheds located in southern Quebec that vary with respect to hydro-climatic conditions, soil properties and forest cover. Average total BC weathering rates for the 21 watersheds were 0.41±0.09 (±SE), 1.20±0.17 and 1.71±0.22kmolcha−1yr−1 for PEDON, WATERSHED and MODEL, respectively. Passing and Bablok regression analysis demonstrated good agreement between WATERSHED and MODEL {regression formula: WATERSHED=−0.08+0.74 MODEL, with 95% CI for intercept −1.13; 0.25 and for slope 0.40; 1.43}, while poorer agreements were observed between these two methods and PEDON. Contrary to the WATERSHED and the MODEL methods, BC weathering rates obtained with PEDON were not significantly associated with the spatial variation of the soil calcite content and of the size of the soil exchangeable BC pools. We hypothesized that in the calcite-containing watersheds, the performance of PEDON was negatively impacted by environmental conditions that favored the partial dissolution and leaching of the calcite contained in the initial parent material, including in the material situated at the base of the profile (C horizon).
Modelling of landslides in sensitive clays has long been recognised as a challenge. The strength reduction of sensitive clays when undergoing plastic deformation makes the failure proceed in a ...progressive manner such that a small slope failure may lead to a series of retrogressive failures and thus to an unexpected catastrophic landslide. The clay in the entire process may mimic both solid-like (when it is intact) and fluid-like (when fully remoulded, especially for quick clays) behaviours. Thereby, a successful numerical prediction of landslides in sensitive clays requires not only a robust numerical approach capable of handling extreme material deformation but also a sophisticated constitutive model to describe the complex clay behaviour. In this paper, the particle finite element method (PFEM) associated with an elastoviscoplastic model with strain softening is adopted for the reconstruction of the 2010 Saint-Jude landslide, Quebec, Canada, and detailed comparisons between the simulation results and available data are carried out. It is shown that the present computational framework is capable of quantitatively reproducing the multiple rotational retrogressive failure process, the final run-out distance and the retrogression distance of the Saint-Jude landslide. Furthermore, the failure mechanism and the kinematics of the Saint-Jude landslide and the influence of the clay viscosity are investigated numerically, and in addition, their implications to real landslides in sensitive clays are discussed.
Résumé
L'étude de l'histoire contemporaine de la géographie au prisme de la sociologie des professions permet de s'intéresser aux « trajectoires professionnelles », et ce, à titre d'objets. Par ...l'analyse de documents d'archives, trois périodes ont pu être établies, montrant ainsi les particularités contextuelles des débats entourant la présence des géographes dans le milieu professionnel. De 1945 à 1962, on observe la tripartition graduelle de la géographie dans trois catégories d'espaces sociaux distincts, soit les écoles, l'université et le milieu professionnel. De 1963 à 1978, on constate la naissance et le déclin d'un projet collectif équivoque, à savoir celui de la création d'une corporation des géographes du Québec. De 1979 à la fin du 20e siècle, on remarque une valorisation de l'Association des géographes du Québec (AGQ), devenue l'Association professionnelle des géographes du Québec (APGQ) en 1985, à titre de lieu de représentation démocratique et de défense des intérêts professionnels des géographes.
The study of the contemporary history of geography through the prism of the sociology of professions makes it possible to explore geographers' professional paths as objects of sociohistorical enquiry. Through the analysis of archival documents, three periods have been delineated, thus showing the contextual nature of the debates surrounding the presence of geographers in the workplace. From 1945 to 1962, we observe the gradual division of geography into three categories of distinct social realms: schools, university, and the professional environment. From 1963 to 1978, we witness the rise and fall of a controversial collective project, namely the foundation of a provincial accreditation board for Quebec's geographers. From 1979 to the end of the 20th century, we can notice the evolution of the “Association des géographes du Québec”, which became the “Association professionnelle des géographes du Québec” in 1985. Despite the failure of the accreditation body project, the association reveals itself as a place of democratic representation and defence of applied geography and geographer's expertise.
Messages clés
La sociologie des professions offre un cadre pertinent pour analyser les trajectoires professionnelles n'ayant pas abouti en une prise en charge légale de certains groupes œuvrant dans le milieu professionnel.
L'histoire des relations entre les géographes du Québec et la question professionnelle peut se structurer en trois temps, mettant au jour la tripartition de la discipline (écoles, université, milieu professionnel).
Du point de vue sociohistorique, des géographes du Québec ont tenté de s'organiser suivant le modèle de la corporation professionnelle (entre 1963 et 1978) avant d'opter pour une valorisation du milieu associatif comme lieu de défense des intérêts professionnels.
•Model based on rainfall thresholds was developed to forecast CSO occurrence.•CSO records for 4285 overflow structures (OS) in Quebec were analyzed.•Probability of days with CSO were used to estimate ...the rainfall threshold value.•Threshold model has demonstrated significant forecast skill for 91.3% of the OS.
Combined Sewer Overflow (CSO) has been recognized as a major environmental issue in many countries. In Canada, the proposed reinforcement of the CSO frequency regulations will result in new constraints on municipal development. Municipalities will have to demonstrate that new developments do not increase CSO frequency above a reference level based on historical CSO records. Governmental agencies will also have to define a framework to assess the impact of new developments on CSO frequency and the efficiency of the various proposed measures to maintain CSO frequency at its historic level. In such a context, it is important to correctly assess the average number of days with CSO and to define relationships between CSO frequency and rainfall characteristics. This paper investigates such relationships using available CSO and rainfall datasets for Quebec. CSO records for 4285 overflow structures (OS) were analyzed. A simple model based on rainfall thresholds was developed to forecast the occurrence of CSO on a given day based on daily rainfall values. The estimated probability of days with CSO have been used to estimate the rainfall threshold value at each OS by imposing that the probability of exceeding this rainfall value for a given day be equal to the estimated probability of days with CSO. The forecast skill of this model was assessed for 3437 OS using contingency tables. The statistical significance of the forecast skill could be assessed for 64.2% of these OS. The threshold model has demonstrated significant forecast skill for 91.3% of these OS confirming that for most OS a simple threshold model can be used to assess the occurrence of CSO.
This book is being published to mark the 250th anniversary of the siege of Quebec. But unlike other books on this celebrated event, this account is set against a much wider canvas. The book is ...divided into three parts: each telling the story of one of the three eighteenth-century sieges of Quebec. There will be illustrations and maps included. By chronicling the events of three very different sieges, across two separate eighteenth-century conflicts, Dr Manning offers an exciting new perspective on events. He does not just concern himself with the celebrated siege by Wolfe in 1759.The importance of Quebec and the role it played during both the Seven Years War and the American War of Independence is fundamental. The geographical position of the city is emphasised to show how the city played such a vital part in eighteenth-century conflicts. The power of the city to draw historical figures such as Benedict Arnold and George Washington is described. The British attached enormous importance to its capture of North America from the French, all this being explained in the fuller context of The Seven Years War. But at all times the author concentrates on the detail of military strategy. The final battle on The Plains of Abraham is chronicled by a detailed analysis of Wolfe's genius and the reasons for his military success. The conflict was however far from over. At the battle of St Foy in 1760, the French beat the British and laid siege to Quebec once again. They failed however and the intervention of The Royal Navy in May then proved decisive as the British were finally able to force the French Army back to Montreal and capture the city. But Britain's relations with her new North American colonial subjects quickly turned sour, leading directly to the outbreak of war between Britain and her American subjects. The final siege of Quebec was by the Americans in 1776. It failed and the future of Canada as a separate political entity was assured. This is a thrilling tale told with consummate skill and real narrative pace.
Icing occurs each winter along the floodplain of the Kuuguluk River in the continuous permafrost zone at Salluit in Nunavik (Quebec), Canada. The source of successive water overflows which thicken ...and enlarge this ice cover over time is suprapermafrost groundwater discharging from a talik below the riverbed. Electrical resistivity tomography was used to delineate the talik, while water level and temperature dataloggers were used to assess the thermo‐hydraulic conditions of the riverbed. The mean annual riverbed temperature was 1.8°C in 2016 while the mean annual air temperature was −6.0°C. Hydraulic heads below the ice cover as high as 2.8 m and events of abrupt decreases in hydraulic head due to suprapermafrost groundwater overflow through cracks in the ice cover were monitored. An analytical solution based on beam mechanics theory was used to assess the water pressure‐induced stresses which are sufficient to fracture the ice cover. A detailed conceptual model of the talik and icing dynamics is proposed to explain the cryo‐hydrogeological processes taking place in this complex groundwater–river system. The groundwater pressure buildup in the talik during the winter is due to constricted flow of suprapermafrost groundwater in the talik. These results have implications for understanding the dynamics of river taliks and their use as potential water supplies in northern communities.
Display omitted
•Four events of deformation are recorded along the Cadillac Fault Zone.•The Cadillac Fault Zone is segmented according to varying structural style.•Segmentation of the fault possibly ...reflects influence of inherited structures.•A regional-scale model for evolution of the Cadillac Fault Zone is proposed.•Segmentation correlates with distribution of orogenic gold mineralization types.
The Cadillac Fault Zone (CFZ) is a 250km-long east-trending crustal discontinuity associated with numerous world-class gold deposits in the Archean Abitibi Subprovince. In Quebec, the fault follows the boundary between the Abitibi and the Pontiac Subprovinces and can be divided into four segments: 1) Rouyn, 2) Joannes, 3) Malartic, and 4) Val-d’Or. Each displays different attitudes and structural styles. The Malartic segment strikes SE, whereas the other segments are E-trending. Abrupt changes in strike or smaller-scale faults represent limits between the segments.
Structural styles include four generations of foliation with numerous shear sense indicators and folding specifically related to each foliation. Structural features can be correlated from one segment to another, but display clear variations in attitude or expression. A stretching lineation signature is definitely associated with each segment. In the Malartic segment, the predominant E-trending schistosity displays an angular relationship with the contact between groups and bedding, suggesting that the SE-trending architecture of this segment was already emplaced prior to ductile deformation.
The evidence suggests a model where the CFZ originates from several independent structures inherited from volcanism prior to Timiskaming deformation and Abitibi-Pontiac accretion. The proto-CFZ was then linked up during the Timiskaming deposition, forming high-strain zones. Inherited structures form the frame on which each deformation event was overprinted with different responses depending on segmentation.
The structural styles of each segment can be integrated in a structural evolution model for the CFZ. The N-S shortening led to the development of a dominantly E-striking penetrative foliation and folding. During the subsequent extensional stage, the CFZ was reactivated with normal kinematics during the Pontiac uplift. A third deformation event is represented by the local development of NW-trending cleavage axial planar to the “S”-shaped minor folds. Finally, a late NW-SE shortening event produced a dextral strike-slip movement, with NE-striking vertical foliation and development of “Z”-shaped folds on bedding surfaces and anterior fabrics.
Linkage of the CFZ had a major impact on hydrothermal activity in the southern Abitibi as it channeled fluids along large-scale pathways. Distribution of gold-bearing intrusions can also be related to segmentation and inherited structures of the CFZ. This association is expressed by gold mineralization styles present in several longitudinal fields reflecting fault segmentation.
Peu documenté, le drainage souterrain fait partie de l’histoire du Québec depuis son tout début en 1850, et depuis son achat de la première draineuse mécanisée au Canada en 1902. Le but du présent ...article est donc de documenter cette historie de 1850 à 1967. L’église catholique a activement participé à l’éducation des communautés rurales francophones du Québec en fondant plusieurs écoles d’agriculture. Du côté anglophone, le Collège Macdonald (Campus Macdonald de l’Université McGill University) jouait un rôle important surtout pour la préparation de plans, en plus de sa vulgarisation. Le Ministère de l’Agriculture encourageait le drainage souterrain à compter de 1912 mais lui adressait peu d’importance pour défricher et excaver les cours d’eaux, afin de trouver des emplois à la suite des deux grandes guerres mondiales, et de la grande dépression de 1930. Une fois les travaux de creusage de cours d’eau pratiquement réalisés vers le début des années 1960, le Ministère lançait un important programme de drainage souterrain pour ensuite laisser la relève aux entrepreneurs privés peu après 1967. En dépit de ses nombreux changements de nom même après 1967, le présent article utilise simplement le nom de ‘Ministère de l’Agriculture’. Pour comparer le taux d’installation de drainage souterrain, un écartement moyen de 15m sera présumé. Le présent article vise a souligner les éléments importants de l’histoire du drainage souterrain au Québec, ne pouvant mentionner tous ceux-ci ni toutes les personnes impliquées.
Despite its beginning in the 1850’s and being first in Canada to purchase a tile drainage trencher, subsurface drainage of agricultural lands in Quebec is poorly documented, which the present paper ...will try to document from 1850 to 1970. In Quebec, Catholic priests and monks played an important role in educating rural communities by establishing French agricultural schools throughout the province. For the English rural communities, Macdonald College (Macdonald Campus of McGill University) played a major role especially in preparing plans, besides promoting the technology. The Quebec Ministry of Agriculture encouraged subsurface drainage early in 1912 but would prefer investing in land clearing and watercourse deepening to establish more farms, from the employment needs created by WWI, the great 1930 depression and WWII. This work mostly completed in the early 1960’s, the Quebec Government would then initiate a major subsurface drainage program, allowing private enterprises to take over shortly after 1967. Although the Ministry changed names several times even after 1967, the term ‘Ministry of Agriculture’ will be used throughout this article. To compare trencher performance, a 15 m average spacing is presumed. This paper is limited to the main events and persons involved, without being able to cover them all.
PDF
