Modeling Site Amplification in Eastern Canada on a Regional Scale

2016 ◽  
Vol 87 (4) ◽  
pp. 1008-1021 ◽  
Author(s):  
Sebastian Braganza ◽  
Gail M. Atkinson ◽  
Hadi Ghofrani ◽  
Behzad Hassani ◽  
Luc Chouinard ◽  
...  
Keyword(s):  
Regional Scale ◽  
Site Amplification ◽  
Eastern Canada

A regional analysis of the impact of dams on water temperature in medium-size rivers in eastern Canada

2016 ◽  
Vol 73 (12) ◽  
pp. 1885-1897 ◽  
Author(s):  
Audrey Maheu ◽  
André St-Hilaire ◽  
Daniel Caissie ◽  
Nassir El-Jabi ◽  
Guillaume Bourque ◽  
...  
Keyword(s):  
Water Temperature ◽  
Thermal Regime ◽  
Regional Scale ◽  
Regional Analysis ◽  
Annual Runoff ◽  
Rate Of Change ◽  
Medium Size ◽  
Regulated Rivers ◽  
Eastern Canada ◽  
The Impact

Various studies have helped gain a better understanding of the thermal impacts of dams on a site-specific basis, but very few studies have compared the thermal impacts of varying types of dams within the same region. In this study, we conducted a regional-scale assessment of the impacts of dams on the thermal regime of 13 medium-size rivers in eastern Canada. The objectives of this study were to identify features of the thermal regime of rivers that are predominantly impacted by dams and to compare the impacts associated with different types of regulation (run-of-river, storage, peaking). The thermal regime of regulated and unregulated rivers was characterized using 15 metrics that described the magnitude, frequency, duration, timing, and rate of change of water temperature. Results indicate that storage and peaking dams impounding at least 10% of the median annual runoff generally (i) reduced the magnitude of water temperature variation at seasonal, daily, and subdaily timescales and (ii) increased the monthly mean water temperature in September. This regional assessment offers important insight regarding a generalized pattern of thermal alteration by dams, and this information could be used to guide biological monitoring efforts in regulated rivers.

scholarly journals Development of A Methodology For Predicting Landslide Hazards At A Regional Scale

2021 ◽  
Author(s):  
Blanche Richer ◽  
Ali Saeidi ◽  
Maxime Boivin ◽  
Alain Rouleau
Keyword(s):  
Stability Analysis ◽  
3D Model ◽  
Regional Scale ◽  
Back Analysis ◽  
Initial Step ◽  
Landslide Risk ◽  
Target Area ◽  
Eastern Canada ◽  
Study Region ◽  
Electric Induction

Abstract Landslide risk analysis is a common geotechnical evaluation and aims to protect life and infrastructure. In the case of sensitive clay zones, landslides can affect large areas and are difficult to predict. Here we propose a methodology to determine the landslide hazard across a large territory, and we apply our approach to the Saint-Jean-Vianney area, Quebec, Canada. The initial step consists of creating a 3D model of the surficial deposits of the target area. After creating a chart of the material electrical resistivity adapted for eastern Canada, we applied electric induction to interpret the regional soil. We collected samples from the main lithologies and estimated selected soil geotechnical parameters in laboratory tests. We transposed parameter values obtained from the samples to a larger scale that of a slope using the results of a back analysis undertaken on an earlier, smaller slide within the same area. The regional 3D model of deposits is then used to develop a zonation map of at-risk slopes and their respective constraint areas with the study region. This approach allowed us to target specific areas where a more precise stability analysis would be required. Our methodology offers an effective tool for stability analysis in territories characterized by the presence of sensitive clays.

scholarly journals Regional Climate, Edaphic Conditions and Establishment Substrates Interact to Influence Initial Growth of Black Spruce and Jack Pine Planted in the Boreal Forest

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 139 ◽  
Author(s):  
Mohammed Henneb ◽  
Nelson Thiffault ◽  
Osvaldo Valeria
Keyword(s):  
Black Spruce ◽  
Wood Fiber ◽  
Regional Scale ◽  
Jack Pine ◽  
Growth Monitoring ◽  
Initial Growth ◽  
Eastern Canada ◽  
Growth Variability ◽  
Pinus Spp ◽  
Precipitation And Temperature

In eastern Canada, spruces (Picea spp.) and pines (Pinus spp.) are among the main commercial species being logged for their lumber or wood fiber. Annually, about 175 million seedlings are planted in areas totaling ~100,000 ha. Appropriate microsite selection is essential during reforestation operations, given that it can improve the chances of survival and initial growth of the seedlings. In fir (Abies spp.) and spruce forests of eastern Canada, the optimal characteristics of establishment microsites have yet to be identified; these would be determined by different physical and climatic variables operating at several scales. Our study determined the influence of climatic (regional-scale), edaphic (stand-scale), local (microsite-scale) and planting conditions on the establishment substrate and initial growth of black spruce (Picea mariana Britton, Sterns and Poggenb.) and jack pine (Pinus banksiana Lamb.). Substrate characterization and growth monitoring (three growing seasons) for the two species were conducted on 29 planted cutblocks that were distributed over an east–west climatic gradient (precipitation and temperature) in the balsam fir and black spruce–feather moss forests of Quebec (Canada). Linear mixed models and multivariate analyses (PCAs) determined the effects of climatic, edaphic and micro-environmental variables and their interactions on the establishment substrate and seedling initial growth. The predictive models explained, respectively, 61% and 75% of the growth variability of black spruce and jack pine. Successful establishment of black spruce and jack pine depended upon regional conditions of precipitations and temperature, as well as on their interactions with stand-scale edaphic variables (surface deposit, drainage and slope) and local variables (micro-environmental) at the microsite-scale (establishment substrate types and substrate temperature). Mineral, organo-mineral and organic establishment substrates exerted mixed effects on seedling growth according to regional precipitation and temperature conditions, as well as their interactions with edaphic and local variables at the stand and microsite-scales, respectively.

scholarly journals Occupancy of the American Three-toed Woodpecker in a Heavily Managed Boreal Forest of Eastern Canada

2020 ◽  
Author(s):  
Vincent Lamarre ◽  
Junior A. Tremblay
Keyword(s):  
Boreal Forest ◽  
Protected Areas ◽  
High Probability ◽  
Black Spruce ◽  
Regional Scale ◽  
Forest Harvesting ◽  
Probability Of Detection ◽  
Habitat Characteristics ◽  
Eastern Canada ◽  
Old Growth Forest

The southern extent of the boreal forest in North America has experienced intensive human disturbance in the past decades. Among these, forest harvesting leads to the substantial loss of late-successional stands that include key habitat attributes for several avian species. The American Three-toed Woodpecker, Picoides dorsalis, is associated with continuous old spruce forests in the eastern part of its range. In this study, we assess the influence of habitat characteristics at different scales on the occupancy of American Three-toed Woodpecker in a heavily managed boreal landscape of northeastern Canada, and we inferred species occupancy at the regional scale. We conducted 185 playback stations over two breeding seasons and modelled the occupancy of the species while taking into account the probability of detection. American Three-toed Woodpecker occupancy was lower in stands with large areas recently clear-cut, and higher in landscapes with large extents of old-growth forest dominated by black spruce. At the regional scale, areas with high probability of occupancy were scarce and mostly within protected areas. Habitat requirements of the American Three-toed Woodpecker during the breeding season, coupled with over-all low occupancy rate in our study area, challenge its long-term sustainability in such heavily managed landscapes. Additionally, the scarcity of areas of high probability of occupancy in the region suggest that the ecological role of old forest outside protected areas could be compromised.

Observing Maturing Source Rocks on Seismic Reflection Data

Geophysics ◽  
2020 ◽  
pp. 1-56
Author(s):  
T. Matava ◽  
R. G. Keys ◽  
S. E. Ohm ◽  
S. Volterrrani
Keyword(s):  
Source Rock ◽  
Seismic Data ◽  
Pore Space ◽  
Regional Scale ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
Maturity Model ◽  
Eastern Canada ◽  
Amplitude Response ◽  
Seismic Reflection Data

Hydrocarbon generation in a source rock is a complex, irreversible phase change that occurs when a source rock is heated during burial to change phase to a fluid. The fluid density is less than the kerogen density so in a closed or partially closed system the volume of the pore space occupied by fluids increases. Burial also increases the effective stress which leads to compaction and a significant reduction in porosity. The challenge of identifying source rocks on seismic data then becomes differentiating the smaller porosity increase due to hydrocarbon formation from the larger porosity decrease associated with burial. We use a calibrated rock physics model to show that Vshale and porosity data can be used to predict the compressional and shear wave velocities and the density in wells over large sedimentary sections, including a source rock of variable maturity. These well data and models show that the difference between an immature and mature source rock is an increase porosity (lower density) relative to compacting, non-source rock sediments. We use these results to identify a potential source interval in the Orphan Basin in Eastern Canada on 2D regional seismic data. We show that the full stack amplitude response of a maturing source rock is significant during the main phase of generation (0.2<transformation ratio<0.8) relative to surrounding sediments. Regional scale consistency of the amplitude response with the kerogen maturity model from an integrated basin simulator reduces exploration risk because the independence of the thermal model from the seismic amplitude response. Finally, combining the seismic response with the source rock maturity model provides insight into the likely kerogen kinetics. Most applications require regional data sets to capture the maturity window, however, applications are also possible around allochthonous salt where geometries can lead to local changes in heat flow.

Re-thinking site amplification in regional seismic risk assessment

2020 ◽  
Vol 36 (1_suppl) ◽  
pp. 274-297 ◽  
Author(s):  
Graeme Weatherill ◽  
Sreeram Reddy Kotha ◽  
Fabrice Cotton
Keyword(s):  
Risk Assessment ◽  
Seismic Hazard ◽  
Ground Motion ◽  
Regional Scale ◽  
Site Amplification ◽  
Direct Function ◽  
Motion Models ◽  
Topographic Slope ◽  
Ground Motion Model ◽  
Hazard And Risk

Probabilistic assessment of seismic hazard and risk over a geographical region presents the modeler with challenges in the characterization of the site amplification that are not present in site-specific assessment. Using site-to-site residuals from a ground motion model fit to observations from the Japanese KiK-net database, correlations between measured local amplifications and mappable proxies such as topographic slope and geology are explored. These are used subsequently to develop empirical models describing amplification as a direct function of slope, conditional upon geological period. These correlations also demonstrate the limitations of inferring 30-m shearwave velocity from slope and applying them directly into ground motion models. Instead, they illustrate the feasibility of deriving spectral acceleration amplification factors directly from sets of observed records, which are calibrated to parameters that can be mapped uniformly on a regional scale. The result is a geologically calibrated amplification model that can be incorporated into national and regional seismic hazard and risk assessment, ensuring that the corresponding total aleatory variability reflects the predictive capability of the mapped site proxy.

Assessing the Potential Extent of Damage to Inland Lakes in Eastern Canada due to Acidic Deposition. I. Development and Evaluation of a Simple "Site" Model

1990 ◽  
Vol 47 (1) ◽  
pp. 55-66 ◽  
Author(s):  
David R. Marmorek ◽  
Michael L. Jones ◽  
Charles K. Minns ◽  
Floyd C. Elder
Keyword(s):  
Large Scale ◽  
Acidic Deposition ◽  
Regional Scale ◽  
Future Research ◽  
Eastern Canada ◽  
Lake Chemistry ◽  
Site Model ◽  
Sulphate Deposition ◽  
Aquatic Effects ◽  
Extent Of Damage

Large scale aquatic effects of acidic deposition have become a prominent environmental issue in North America and Europe. Models are required to assess the potential future impacts of current levels of acidic deposition, and the potential benefits of emission controls. This paper presents a model that uses measurements of current lake chemistry and assumptions about the processes governing acidification, to first estimate original (i.e. preacidification) lake chemistry and then predict the eventual chemistry expected given a specified level of acidic sulphate deposition. The model is deliberately kept simple, so that its input requirements are modest and thus can be met on a regional scale. When applied on a regional scale the model predicts the expected eventual distributions of alkalinity and pH. Application of the model is illustrated for a watershed in north-central Ontario, which includes the area immediately to the south and west of Sudbury. Model-based estimates of current alkalinity are very similar to observed alkalinities. The predicted eventual alkalinity distributions, given current levels of deposition, indicate a trend towards recovery, consistent with other observations in the Sudbury region. A sensitivity analysis of the model indicates that its outputs are highly sensitive to estimates of preacidification lake sulphate levels, and less so to assumptions about the catchment's ability to neutralize incoming acidity. Simple, regional models such as the one presented in this paper should play a more central role than they presently do both in assessment and in the definition of future research and monitoring needs.

scholarly journals The Impact of a Hemispheric Circulation Regime on Fall Precipitation over North America

2010 ◽  
Vol 11 (5) ◽  
pp. 1182-1189 ◽  
Author(s):  
David Small ◽  
Shafiqul Islam ◽  
Mathew Barlow
Keyword(s):  
North America ◽  
Regional Scale ◽  
Circulation Pattern ◽  
Precipitation Variability ◽  
Eastern Canada ◽  
The North ◽  
Quarter Wavelength ◽  
Leading Mode ◽  
Precipitation Anomalies ◽  
The Impact

Abstract While there is growing evidence that the main contribution to trends in U.S. precipitation occurs during fall, most studies of seasonal precipitation have focused on winter or summer. Here, the leading mode of fall precipitation variability over North America is isolated from multiple data sources and connected to a hemispheric-scale circulation pattern. Over North America, the leading mode of fall precipitation variability in both station-based and satellite-blended data is a tripole that links fall precipitation anomalies in southern Alaska, the central United States, and eastern Canada. This mode is part of a larger pattern of alternating wet and dry anomalies stretching from the western Pacific to the North Atlantic. Dynamically, the precipitation anomalies are closely associated with changes to regional-scale moisture transport that are, in turn, linked to two independently identified hemispheric-scale wave patterns that are one-quarter wavelength out of phase (i.e., in quadrature) and resemble the circumglobal teleconnection.

scholarly journals Occupancy of the American Three-Toed Woodpecker in a Heavily-Managed Boreal Forest of Eastern Canada

Diversity ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 35
Author(s):  
Vincent Lamarre ◽  
Junior A. Tremblay
Keyword(s):  
Boreal Forest ◽  
Protected Areas ◽  
High Probability ◽  
Black Spruce ◽  
Regional Scale ◽  
Forest Harvesting ◽  
Probability Of Detection ◽  
Habitat Characteristics ◽  
Eastern Canada ◽  
Old Growth Forest

The southern extent of the boreal forest in North America has experienced intensive human disturbance in recent decades. Among these, forest harvesting leads to the substantial loss of late-successional stands that include key habitat attributes for several avian species. The American Three-toed Woodpecker, Picoides dorsalis, is associated with continuous old spruce forests in the eastern part of its range. In this study, we assessed the influence of habitat characteristics at different scales on the occupancy of American Three-toed Woodpecker in a heavily-managed boreal landscape of northeastern Canada, and we inferred species occupancy at the regional scale. We conducted 185 playback stations over two breeding seasons and modelled the occupancy of the species while taking into account the probability of detection. American Three-toed Woodpecker occupancy was lower in stands with large areas recently clear-cut, and higher in landscapes with large extents of old-growth forest dominated by black spruce. At the regional scale, areas with high probability of occupancy were scarce and mostly within protected areas. Habitat requirements of the American Three-toed Woodpecker during the breeding season, coupled with overall low occupancy rate in our study area, challenge its long-term sustainability in such heavily managed landscapes. Additionally, the scarcity of areas of high probability of occupancy in the region suggests that the ecological role of old forest outside protected areas could be compromised.

Climate change effects on native fauna of northeastern forestsThis article is one of a selection of papers from NE Forests 2100: A Synthesis of Climate Change Impacts on Forests of the Northeastern US and Eastern Canada.

2009 ◽  
Vol 39 (2) ◽  
pp. 249-263 ◽  
Author(s):  
Nicholas L. Rodenhouse ◽  
Lynn M. Christenson ◽  
Dylan Parry ◽  
Linda E. Green
Keyword(s):  
Climate Change ◽  
Regional Scale ◽  
Climate Change Impacts ◽  
Active Species ◽  
Climate Projections ◽  
Eastern Canada ◽  
Climate Change Effects ◽  
Precipitation Regimes ◽  
Emissions Scenarios ◽  
Insect Populations

We review the observed and potential effects of climate change on native fauna of forests in northeastern North America by focusing on mammals, birds, amphibians, and insects. Our assessment is placed in the context of recent regional-scale climate projections. Climate change, particularly in recent decades, has affected the distribution and abundance of numerous wildlife species. Warming temperatures, alterations to precipitation regimes, seasonality, and climatic extremes are projected to affect species directly or indirectly in each of the focal taxa. Greatest climate change will occur during winter, and the survival of winter-active species as well as the survival, distribution, and abundance of hibernating mammals, amphibians, resident birds, and diapausing insects may be altered. Even under low emissions scenarios, effects on native fauna may be profound, affecting iconic species, endangered species, and species that provide economically valuable services, such as pollination and regulation of insect populations. However, much research that is essential to assessing the effects of climate change on the native fauna of northeastern forests remains to be done. Research that reveals causal mechanisms and relates these findings to population and community level processes will be most valuable.

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