Ice-wedge polygons distribution, morphometry and state in the Tombstone Territorial Park, Central Yukon, Canada

2020 ◽  
Author(s):  
Roxanne Frappier ◽  
Denis Lacelle
Keyword(s):  
Climate Changes ◽  
Side Surface ◽  
Surface Expression ◽  
Field Observations ◽  
Ice Wedge ◽  
Formation Of Cracks ◽  
Landscape Factors ◽  
Remote Sensing Techniques ◽  
The Relationship ◽  
Winter Cooling

<p>Ice wedge (IW) polygons form through thermal contraction induced by winter cooling of ice-rich permafrost which results in the formation of cracks. Hoar frost develops in the cracks in winter and meltwater infills the cracks during spring and freezes. As the cracking and infilling occurs repeatedly, IWs grow, leading to characteristic surface morphology with depressions or troughs aligned on the axis of the IW and raised rims or ridges on either side. Surface expression of IW is either characterized as low-centered polygons or high-centered polygons, the former being associated with the first stages of IW development, and the latter with IW degradation. Because IWs represent important excess ice close to the surface, considerable local subsidence and related effects on landscape parameters, such as vegetation and moisture, are likely to occur upon degradation.</p><p>IW polygons distribution, morphometry and state were characterized in the Tombstone Territorial Park (Central Yukon, Canada) using semi-automated remote sensing techniques, field observations and laboratory analyses. The data is used to define determining landscape factors for IW polygons occurrence, to characterise the stages of the IWs development and/or degradation and to estimate the volume of buried ice in the region. Results show that elevation, slope and material are important elements defining IW polygons distribution. The relationship between landscape factors and stages of development is not as clear, and, despite climate changes being homogenous in the area, IW development and degradation is very heterogenous, as shown by the differing moisture, greenness and brightness signals across the polygonal terrain.</p>

ANALYSIS OF THE INFLUENCE OF DIMENSIONS OF THE ROPE MIDWATER TRAWLS ON THEIR PERFORMANCE SUBJECT TO GEOMETRIC PROPERTIES OF CONE SHELLS

2017 ◽  
pp. 25-33
Author(s):  
Alexander Vasilievich Dvernik
Keyword(s):  
Surface Properties ◽  
Conical Shell ◽  
Side Surface ◽  
Theoretic Analysis ◽  
Good Convergence ◽  
Large Size ◽  
Quality Coefficient ◽  
Geometric Quality ◽  
The Relationship ◽  
Parameters Calculation

The article studies different shell constructions of mid-water trawls and their properties. The problem settled is suggested to be solved taking into account real geometric interrelations between spacious and surface properties of cone shells. The author suggests to accept a so-called geometric quality coefficient as a criterion of the properties of a conical shell, which represents the ratio of the shell to the area of its side surface and by analogy to use it to the shell of the trawl. The relationship between the trawl dimensions and geometric quality coefficient have been studied. Comparing these figures with the actual characteristics of trawls showed good convergence. According to the results of theoretic analysis and parameters calculation, trawl large-size shells will always have advantages in geometric characteristics over mid-size and, especially, small-size shells. The results of the analysis can be used for approximate calculations of the parameters of the trawl and justification of ways to improve the performance of existing mid-water trawls.

scholarly journals Climate bones of contention: How climate variability influences territorial, maritime, and river interstate conflicts

2021 ◽  
Vol 58 (1) ◽  
pp. 132-150
Author(s):  
Cody J Schmidt ◽  
Bomi K Lee ◽  
Sara McLaughlin Mitchell
Keyword(s):  
Climate Variability ◽  
Climate Changes ◽  
Heat Waves ◽  
World Politics ◽  
Western Hemisphere ◽  
Intrastate Conflict ◽  
Short Term ◽  
Climate Conditions ◽  
Interstate Conflicts ◽  
The Relationship

Many scholars examine the relationship between climate variability and intrastate conflict onset. While empirical findings in this literature are mixed, we know less about how climate changes increase the risks for conflicts between countries. This article studies climate variability using the issue approach to world politics. We examine whether climate variability influences the onset and militarization of interstate diplomatic conflicts and whether these effects are similar across issues that involve sovereignty claims for land (territory) or water (maritime, river). We focus on two theoretical mechanisms: scarcity ( abundance) and uncertainty. We measure these concepts empirically through climate deviation (e.g. droughts/floods, heat waves/cold spells) and climate volatility (greater short-term variance in precipitation/temperature). Analyses of issue claims in the Western Hemisphere and Europe (1901–2001) show that greater deviations and volatility in climate conditions increase risks for new diplomatic conflicts and militarization of ongoing issues and that climate change acts as a trigger for revisionist states.

scholarly journals The Effects of Landscape Elements on the Breeding Sites of Bloodsucking Midge

2021 ◽  
Vol 13 (5) ◽  
pp. 2863
Author(s):  
Kaowen Grace Chang ◽  
Hungju Chien
Keyword(s):  
Ground Surface ◽  
Preventive Strategies ◽  
Careful Selection ◽  
Public Concern ◽  
Breeding Sites ◽  
Algae Growth ◽  
Potential Habitats ◽  
Landscape Factors ◽  
The Relationship ◽  
Selection Of

Forcipomyia taiwana, a bloodsucking midge that is one of the most irritating biting pests in Taiwan, has raised widespread public concern. However, we have little information about the extent to which landscape factors affect their potential habitats. As a result, landscape professionals do not have enough information to implement preventive strategies to control midges. The purpose of this study is to investigate the relationship between landscaping and algae growth for larval breeding sites of Forcipomyia taiwana. The intent is to determine the environmental strategies that make the planned landscape unsuitable for midges to breed. GIS based on data collected from 16 constructed landscape sites (317,187 m2 in total) was utilized to spatially examine the relationship between the occurrence of the algae for midge breeding sites and the ground surface types and planting characteristics in each landscape. The results revealed that the potential midge habitats can be controlled through careful selection of the ground surface, the improvement of the site drainage, and choosing plants with the appropriate characteristics. Apart from choosing the appropriate type of paving surface, the integrity of the paving installation and the coverage of the ecological surface also influence prevention efficacy.

scholarly journals Sustainable overall social transformation as a way of progress.

2020 ◽  
Vol 16 ◽  
pp. 126-139
Author(s):  
Arkady Martynov
Keyword(s):  
Social System ◽  
Social Transformation ◽  
Climate Changes ◽  
Social Progress ◽  
System Transformation ◽  
Organizational Changes ◽  
Exogenous Factors ◽  
Exhaustive Study ◽  
System Sustainability ◽  
The Relationship

The paper concerns the fundamental issues of the sustainable social progress. As follows from the argumentation, a realistic design of institutional changes in connection with resource and organizational changes needed for sustainable progress is called for to realize in the line of overall social system transformation. This approach presupposes an exhaustive study of interconnected transformations in the main societal fields as system processes considering the influence of relatively exogenous factors (technological, demographic and climate changes). In turn, it is advisable, taking in view current world challenges, to expose an idea of ​​universal sustainability, the property of which is inherent in all social practices, and not just mediating the relationship between society and its environment. The first result of study concludes in revealing the fundamentals of overall social system sustainability. The second result: the transition to sustainable transformation of society supposes the synergetic implementation of structure-forming system and policy-driven shifts.

scholarly journals Sustainable Progress – The Achievable Result of Overall Social System Transformation

2020 ◽  
Vol 1 (2) ◽  
pp. p89
Author(s):  
Arkady Martynov
Keyword(s):  
Social System ◽  
Climate Changes ◽  
Social Practices ◽  
Social Progress ◽  
System Transformation ◽  
Organizational Changes ◽  
Exogenous Factors ◽  
Exhaustive Study ◽  
System Sustainability ◽  
The Relationship

The paper concerns the fundamental issues of the sustainable social progress. As follows from the argumentation, a realistic design of institutional changes in connection with resource and organizational changes needed for sustainable progress is called for to realize in the line of overall social system transformation. This approach presupposes an exhaustive study of interconnected transformations in the main societal fields as system processes considering the influence of relatively exogenous factors (technological, demographic and climate changes). In turn, it is advisable, taking in view current world challenges, to expose an idea of universal sustainability, the property of which is inherent in all social practices, and not just mediating the relationship between society and its environment.The first result of study concludes in revealing the fundamentals of overall social system sustainability. The second result: the transition to sustainable transformation of society supposes the synergetic implementation of structure-forming system and policy-driven shifts.

scholarly journals Water stress coefficient determined by orbital remote sensing techniques

2020 ◽  
Vol 24 (12) ◽  
pp. 847-853
Author(s):  
Élvis da S. Alves ◽  
Roberto Filgueiras ◽  
Lineu N. Rodrigues ◽  
Fernando F. da Cunha ◽  
Catariny C. Aleman
Keyword(s):  
Remote Sensing ◽  
Water Stress ◽  
Irrigation Management ◽  
Simple Algorithm ◽  
Landsat 8 ◽  
Stress Coefficient ◽  
Use Efficiency ◽  
Remote Sensing Techniques ◽  
Water Stress Coefficient ◽  
The Relationship

ABSTRACT In regions where the irrigated area is increasing and water availability is reduced, such as the West of the Bahia state, Brazil, the use of techniques that contribute to improving water use efficiency is paramount. One of the ways to improve irrigation is by improving the calculation of actual evapotranspiration (ETa), which among other factors is influenced by soil drying, so it is important to understand this relationship, which is usually accounted for in irrigation management models through the water stress coefficient (Ks). This study aimed to estimate the water stress coefficient (Ks) through information obtained via remote sensing, combined with field data. For this, a study was carried out in the municipality of São Desidério, an area located in western Bahia, using images of the Landsat-8 satellite. Ks was calculated by the relationship between crop evapotranspiration and ETa, calculated by the Simple Algorithm for Evapotranspiration Retrieving (SAFER). The Ks estimated by remote sensing showed, for the development and medium stages, average errors on the order of 5.50%. In the final stage of maize development, the errors obtained were of 23.2%.

Seston supply to sea scallops (Placopecten magellanicus) in suspended culture

2001 ◽  
Vol 58 (2) ◽  
pp. 241-253 ◽  
Author(s):  
C A Pilditch ◽  
J Grant ◽  
K R Bryan
Keyword(s):  
Carrying Capacity ◽  
Field Data ◽  
Field Observations ◽  
Placopecten Magellanicus ◽  
Factors Affecting ◽  
Advection Diffusion ◽  
Tidally Driven ◽  
Sea Scallops ◽  
Minimal Reduction ◽  
The Relationship

The filtration activity of dense aggregations of bivalves can locally reduce the concentration of seston, potentially limiting production. Under these conditions, the currents that supply seston cannot offset ingestion by the bivalves and the carrying capacity is exceeded. We conducted a field and modelling study to examine factors affecting seston supply to a culture of suspended sea scallops (Placopecten magellanicus) in Whitehaven Harbour, Nova Scotia. Even though seston flux to the scallops was reduced by 40% due to the attenuation of flow by culture gear, a reduction in seston concentration was not observed. The field data were then used to parameterize a quasi two-dimensional advection-diffusion model that quantified the relationship between the tidally driven seston supply and consumption by scallops. The model predicted a minimal reduction in seston concentration (<5%) within the lease (80 × 50 m), consistent with field observations. However, expanding the lease to occupy the area available for cultivation (1000 × 250 m) reduced the seston concentration in the centre of the lease by 20-50%, potentially limiting growth. Modelling results emphasized that by altering the lease geometry (lease width to length ratio), the supply of seston can be optimized.

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