scholarly journals Combination of Tree Configuration with Street Configuration for Thermal Comfort Optimization under Extreme Summer Conditions in the Urban Center of Shantou City, China

2018 ◽  
Vol 10 (11) ◽  
pp. 4192 ◽  
Author(s):  
Bohong Zheng ◽  
Komi Bernard BEDRA ◽  
Jian Zheng ◽  
Guoguang Wang
Keyword(s):  
Aspect Ratio ◽  
Thermal Comfort ◽  
Tree Species ◽  
Global Climate ◽  
Mangifera Indica ◽  
Analytical Framework ◽  
Tree Planting ◽  
Urban Streets ◽  
Crown Width ◽  
Street Tree

Along with global climate change and the worldwide heat island phenomenon, developing climatic methods and planning practices for the benefit of thermal comfort is of increasing interest. Studies have focused on urban streets, studying the aspect ratio, the orientation, street vegetation patterns, etc. and how they affect thermal comfort. While the role of vegetation is undeniable, this paper asks the question whether the effects of a tree configuration does not vary under different street configurations, and if yes, how to select tree species and determine their appropriate layout. Here, an analytical framework is proposed to test the different tree configurations (changing one variable at a time) with the least favorable street configuration. It is confirmed that the east–west oriented streets are the least favorable cases and denser tree canopies are better for cooling. The interval between the trees are observed to have an optimal effect when it is equal to the crown width at maturity. Furthermore, the results show that the heat mitigation rate of a tree configuration is not linearly improved by the Aspect Ratio (AR). In the case of Shantou city, the improvement of thermal comfort slows down when the AR reaches 1.5 while Mangifera indica planted with 10 m intervals is recommended among the common street-tree species. Other species could be used also, but should meet the requirements of the canopy density and the interval of layout. The paper does not consider other configuration options such as asymmetrical cases of street geometry and one-side or axial tree planting, etc., but the framework allows for adding such options and simulating thermal comfort for a greater number of scenarios.

Effect of tree planting design and tree species on human thermal comfort in the tropics

2015 ◽  
Vol 138 ◽  
pp. 99-109 ◽  
Author(s):  
Loyde Vieira de Abreu-Harbich ◽  
Lucila Chebel Labaki ◽  
Andreas Matzarakis
Keyword(s):  
Thermal Comfort ◽  
Tree Species ◽  
Tree Planting ◽  
Planting Design ◽  
Human Thermal Comfort ◽  
The Tropics

scholarly journals Effect of Competition and Climatic Conditions on the Growth of Beech in the Mixed Pine Beech Stand: Lithuanian Case Study

2020 ◽  
Vol 3 (1) ◽  
pp. 49
Author(s):  
Edgaras Linkevičius ◽  
Gerda Junevičiūtė
Keyword(s):  
Intraspecific Competition ◽  
Tree Species ◽  
Forest Growth ◽  
Competition Effect ◽  
Diameter Increment ◽  
Cart Analysis ◽  
Crown Width ◽  
Beech Stand ◽  
Negative Effect ◽  
The Impact

Climate change and warming will potentially have profound effects on forest growth and yield, especially for pure stands in the near future. Thus, increased attention has been paid to mixed stands, e.g., pine and beech mixtures. However, the interaction of tree species growing in mixtures still remains unknown. Thus, the aim of this study was to investigate the impact of the interspecific and intraspecific competition to diameter, height, and crown width of pine and beech trees growing in mixtures, as well as to evaluate the impact of climatic indicators to the beech radial diameter increment. The data was collected in 2017 at the mixed mature pine beech double layer stand, located in the western part of Lithuania. The sample plot of 1.2 hectare was established and tree species, diameter at the breast height, tree height, height-to-crown base, height-to-crown width, and position were measured for all 836 trees. Additionally, a representative sample of radial diameter increments were estimated only for the beech trees by taking out core discs at the height of 1 m when the stand was partially cut. Competition analysis was based on the distance-dependent competition index, which was further based on crown parameters. Climatic effect was evaluated using classification and regression tree (CART) analysis. We found almost no interspecific competition effect to diameter, height, or crown width for both tree species growing in the first layer. However, it had an effect on beeches growing in the second layer. The intraspecific competition effect was important for pine and beech trees, showing a negative effect for both of them. Our results show the possible coexistence of these tree species due to niche differentiation. An analysis of climatic indicators from 1991–2005 revealed that precipitation from February–May of the current vegetation year and mean temperatures from July to September expressed radial diameter increment effects for beech trees. Low temperatures during March and April, as well as high precipitation during January, had a negative effect on beech radial increments. From 2006–2016, the highest effect on radial diameter increments was the mean temperatures from July to September, as well as the precipitation in January of the current year. From 1991–2016, the highest effect on radial diameter increments was the temperature from July to September 1991–2016 and the precipitation in June 1991–2016. Generally, cool temperatures and higher precipitation in June had a positive effect on beech radial increments. Therefore, our results show a sensitivity to high temperatures and droughts during summer amid Lithuanian’s growth conditions.

scholarly journals Legitimating power: Solar energy rollout, sustainability metrics and transition politics

2021 ◽  
pp. 251484862110249
Author(s):  
Siddharth Sareen
Keyword(s):  
Solar Energy ◽  
Political Ecology ◽  
Global Climate ◽  
Renewable Energy Sources ◽  
Energy Transition ◽  
Analytical Framework ◽  
Solar Irradiation ◽  
Low Carbon ◽  
Sustainability Metrics ◽  
Energy Transitions

Increasing recognition of the irrefutable urgency to address the global climate challenge is driving mitigation efforts to decarbonise. Countries are setting targets, technological innovation is making renewable energy sources competitive and fossil fuel actors are leveraging their incumbent privilege and political reach to modulate energy transitions. As techno-economic competitiveness is rapidly reconfigured in favour of sources such as solar energy, governance puzzles dominate the research frontier. Who makes key decisions about decarbonisation based on what metrics, and how are consequent benefits and burdens allocated? This article takes its point of departure in ambitious sustainability metrics for solar rollout that Portugal embraced in the late 2010s. This southwestern European country leads on hydro and wind power, and recently emerged from austerity politics after the 2008–2015 recession. Despite Europe’s best solar irradiation, its big solar push only kicked off in late 2018. In explaining how this arose and unfolded until mid-2020 and why, the article investigates what key issues ambitious rapid decarbonisation plans must address to enhance social equity. It combines attention to accountability and legitimacy to offer an analytical framework geared at generating actionable knowledge to advance an accountable energy transition. Drawing on empirical study of the contingencies that determine the implementation of sustainability metrics, the article traces how discrete acts legitimate specific trajectories of territorialisation by solar photovoltaics through discursive, bureaucratic, technocratic and financial practices. Combining empirics and perspectives from political ecology and energy geographies, it probes the politics of just energy transitions to more low-carbon and equitable societal futures.

scholarly journals Effects of road traffic on photosynthetic pigments and heavy metal accumulation in tree species of Kumasi Metropolis, Ghana

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Ufere N. Uka ◽  
Ebenezer J. D. Belford ◽  
Florence A. Elebe
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Photosynthetic Pigments ◽  
Tree Species ◽  
Metal Accumulation ◽  
Mangifera Indica ◽  
Polluted Site ◽  
Vehicular Pollution ◽  
Terminalia Catappa ◽  
Polyalthia Longifolia

AbstractThis study was undertaken to examine changes in the content of pigments and accumulation of metals from vehicular pollution in selected species of roadside trees under vehicular pollution. A major arterial road with heavy vehicle emissions in the Kumasi Metropolis was designated as the polluted site, while Kwame Nkrumah University of Science and Technology Campus was designated as the control site. Four tree species (Terminalia catappa, Mangifera indica, Ficus platyphylla and Polyalthia longifolia) selected for the study were well distributed and abundant in the polluted and control sites. Photosynthetic pigments and levels of heavy metals (Pb, Cu, Cd and zinc) were assessed in their leaves. Chlorophyll and carotenoid contents were determined by absorption spectrometry, while the metal accumulation index (MAI) was used to determine the total metal accumulation capacity of the tree species. We observed a reduction in photosynthetic pigments in the leaf samples from the polluted site. Ficus platyphylla had the maximum reduction in total chlorophyll (49.34%), whereas Terminalia catappa recorded the lowest reduction (33.88%). Similarly, the largest decrease (31.58%) of carotenoid content was found in Terminalia catappa trees and the lowest in Polyalthia longifolia (16.67%). The Polyalthia longifolia, Ficus platyphylla and Terminalia catappa leaf samples collected at the polluted site recorded a higher ratio of chlorophyll a/b. Heavy metal (Cu, Pb, Zn and Cd) accumulation in leaf samples was higher in the polluted site than in the control, as expected. The highest metal MAI value was recorded in Mangifera indica (5.35) followed by Polyalthia longifolia with 4.30. The findings from this study specifically demonstrate that air contamination induced by vehicles decreases the level of photosynthetic pigments in trees subjected to roadside emissions. It is clear that both chlorophyll a/b and chlorophyll/carotenoid ratios will act as very useful stress-level markers. Elevated heavy metal levels in the tree species along arterial roadsides indicate that they serve as heavy metals sink. The change in MAI resulting from different pollution burden is an indication that the removal capabilities of the tree species differ from each other. We therefore suggest M. indica and P. longifolia as potential species to be used in air pollution reduction plans in the city.

scholarly journals Europe without Borders: Environmental and Global History in a World after Continents

2021 ◽  
pp. 1-13
Author(s):  
Alison Frank Johnson
Keyword(s):  
Environmental History ◽  
White Supremacy ◽  
Global Climate ◽  
Historical Review ◽  
Analytical Framework ◽  
Blind Spot ◽  
Global History ◽  
Racial Capitalism ◽  
Global Pandemic ◽  
Boundary Making

In 2012 the historian Julia Adeney Thomas restrained her temper but unleashed a warning. The occasion was a forum in the American Historical Review on ‘historiographic “turns” in critical perspective’. The perspectives offered were critical enough, Thomas wrote in praise of the other authors, but the forum had a blind spot: ‘alongside the turns analyzed here, a world-altering force has been emerging, one larger, more devastating, and more definitive even than “contemporary flexible forms of capitalism”: I speak of climate change – or climate collapse – and all of its related global transformations’. Since then, some intersectional scholars have gone beyond that to argue that climate collapse and racial capitalism are not separate topics at all, but are bound together by white supremacy and lingering forms of European imperialism. Over the past decade some environmental historians have grappled with these connections and deployed new frameworks for thinking about scale, the interdependence of the local and the global, the implications of a Euro-centric analytical framework for our understanding of the world and the relationship between economic systems and environmental change. Although they have developed separately, both environmental history and global history have called upon historians of Europe to rethink boundary making in their methodologies and in their categories of analysis. In an era of global climate catastrophe, global pandemic and global economic crisis, where does the ‘European’ environment end?

Mangifera indica (mango).

2021 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez
Keyword(s):  
Tree Species ◽  
Green Manure ◽  
Mangifera Indica ◽  
Forest Tree ◽  
Multipurpose Tree ◽  
Traditional Medicines ◽  
Mango Tree ◽  
Multipurpose Tree Species ◽  
The Tropics

Abstract M. indica is not important as a forest tree as it is seldom found in abundance in forests, but wherever the tree is available it is exploited. It is a multipurpose tree species providing shelterbelts, firewood, timber, fruits, cattle fodder, green manure and medicine. It is primarily used for its edible fruits and extensive plantations have been established throughout the tropics and sub-tropics, under numerous cultivars providing good income for mango growers. Various parts of the mango tree are used in traditional medicines. It also has great significance in Hindu religious ceremonies (Kostermans and Bompard, 1993).

scholarly journals Microclimate Analysis as a Design Driver of Architecture

Climate ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 72 ◽  
Author(s):  
Jonathan Graham ◽  
Umberto Berardi ◽  
Geoffrey Turnbull ◽  
Robert McKaye
Keyword(s):  
Thermal Comfort ◽  
Architectural Design ◽  
Global Climate ◽  
Outdoor Thermal Comfort ◽  
Climate Index ◽  
Design Office ◽  
Scope Project ◽  
Thermal Climate ◽  
Design Options ◽  
Indoor And Outdoor

In the context of global climate change, it is increasingly important for architects to understand the effects of their interventions on indoor and outdoor thermal comfort. New microclimate analysis tools which are gaining appreciation among architects enable the assessment of different design options in terms of biometeorological parameters, such as the Universal Thermal Climate Index (UTCI) and the Outdoor Thermal Comfort Autonomy. This paper reflects on some recent experiences of an architectural design office attempting to incorporate local climatic considerations as a design driver in projects. The investigation shows that most of the available tools for advanced climatic modelling have been developed for research purposes and are not optimized for architectural and urban design; consequently, they require adaptations and modifications to extend their functionality or to achieve interoperability with software commonly used by architects. For this scope, project-specific Python scripts used to extract design-consequential information from simulation results, as well as to construct meteorological boundary conditions for microclimate simulations, are presented. This study describes the obstacles encountered while implementing microclimate analysis in an architectural office and the measures taken to overcome them. Finally, the benefits of this form of analysis are discussed.

scholarly journals Near-axis expansion of stellarator equilibrium at arbitrary order in the distance to the axis

2020 ◽  
Vol 86 (1) ◽  
Author(s):  
R. Jorge ◽  
W. Sengupta ◽  
M. Landreman
Keyword(s):  
Magnetic Field ◽  
Aspect Ratio ◽  
Magnetic Flux ◽  
Arbitrary Order ◽  
Analytical Framework ◽  
Field Vector ◽  
Magnetic Axis ◽  
Direct Construction ◽  
Geometrical Properties ◽  
Rotational Transform

A direct construction of equilibrium magnetic fields with toroidal topology at arbitrary order in the distance from the magnetic axis is carried out, yielding an analytical framework able to explore the landscape of possible magnetic flux surfaces in the vicinity of the axis. This framework can provide meaningful analytical insight into the character of high-aspect-ratio stellarator shapes, such as the dependence of the rotational transform and the plasma beta limit on geometrical properties of the resulting flux surfaces. The approach developed here is based on an asymptotic expansion on the inverse aspect ratio of the ideal magnetohydrodynamics equation. The analysis is simplified by using an orthogonal coordinate system relative to the Frenet–Serret frame at the magnetic axis. The magnetic field vector, the toroidal magnetic flux, the current density, the field line label and the rotational transform are derived at arbitrary order in the expansion parameter. Moreover, a comparison with a near-axis expansion formalism employing an inverse coordinate method based on Boozer coordinates (the so-called Garren–Boozer construction) is made, where both methods are shown to agree at lowest order. Finally, as a practical example, a numerical solution using a W7-X equilibrium is presented, and a comparison between the lowest-order solution and the W7-X magnetic field is performed.

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