Green Fence Research Articles

A Preliminary Study on the Level of Noise Attenuation by a Natural Green Hedge

Traffic noise can be considered a weightless pollutant, and it is far growing daily in urban areas all over the world. Few countries have started to introduce sound barriers to minimize a significant amount of traffic noise. This study investigates the sound reduction ability of a natural green hedge in applying as a noise barrier. The study result is based on a naturally grown green fence of Small Nuga (Ficus benjamina) having a high packing factor with thickness×height×length of 2.0×4.0×6.0 m3. The average weight of the fresh plant of a unit volume of the fence is 5.6 kg. Handheld sound analyzer (IEC 60651, B&K 2250L, class 1) and B&K omni-directional dodecahedron sound source (0.8-3.15 kHz) type 2734-A amplifier (50-5,000 Hz, 1/3 octave bands) are the primary equipment used for the study. The speaker was placed 1 m away from the fence and 1.2 m above the ground. The transmitted sound through the fence was monitored for three locations in a line of 1 m, 2 m, and 3 m with the same speaker level. All exterior sounds were avoided during the measurements. Sound propagation after the green fence was estimated and mapped using iNoise software (version 2021.1) and ArcMap software (version 10.7.1). The study reveals that the vegetation barrier could reduce 34.4% of the incident acoustic energy, and approximately 26 dB of noise drop was identified at a point 2 m away from the vegetation barrier. The adequately structured noise barrier will effectively increase noise reduction.
 Keywords: Traffic noise, Vegetation barriers, Sound absorption, Noise reduction

Green Fences for Buenos Aires: Implementing Green Infrastructure for (More than) Air Quality

Schoolyards in North America and Europe are increasingly using green fences as one measure to protect vulnerable populations from localised air pollution. This paper assesses the possibilities and limits for mobilising this format of site-specific green infrastructure in cities in low- and middle-income countries beset by air pollution and multiple other socio-environmental challenges, and particularly questions the definition of green fences as a green infrastructure for air quality (GI4AQ). We applied several qualitative and action research methods to the question of green fence implementation in Buenos Aires, Argentina—a Latin American city with weak air-quality policies, limited green infrastructure, and little experience with nature-based solutions. Firstly, we conducted a literature review of the role that urban vegetation and ecosystem services may play in AQ policy and the implementation barriers to such approaches globally and in the city. Secondly, we planned, designed, constructed, maintained, and evaluated a pilot green fence in a school playground. Thirdly, we carried out supplementary interviews with stakeholders and expert informants and compiled project members’ narratives to respectively characterise the barriers that the project encountered and delineate its attributes based on the associated actions that we took to overcome such barriers to implementation and complete the pilot. Our findings identify multiple barriers across seven known categories (institutional, engagement, political, socio-cultural, built environment and natural landscape, knowledge base and financial) and highlight examples not previously considered in the extant international literature. Furthermore, learning from this experience, the paper proposes an expanded model of green infrastructure for air quality plus multi-dimensional co-benefits (GI4AQ+) to increase implementation chances by attending to local needs and priorities.

Green infrastructure for air quality plus (GI4AQ+): Defining critical dimensions for implementation in schools and the meaning of ‘plus’ in a UK context

Mitigating poor quality air is vital for children's health, especially in urban areas. In recent years, attention has been paid on how to improve air quality around schools to reduce children's exposure to airborne pollutants. In this paper, we explore the use of green infrastructure for improving air quality in schools as a multifunctional nature-based solution (green infrastructure for air quality plus, ‘GI4AQ+’); a process that comprises additional (co-)benefits, trade-offs or disbenefits for the school community. We report on a collaborative, action-research project that implements a green fence in a school playground in Sheffield, UK with the specific aim of improving local air quality, but potentially provides other benefits as well as drawbacks. Our results suggest that GI4AQ+ provides multiple social, environmental, and economic co-benefits beyond air quality provisioning. Furthermore, four dimensions (place, physical and biological characteristics, and school-friendly considerations) were identified to facilitate the implementation of this type of project in other schools. Thus, GI4AQ+ appears to be a valuable strategy for school greening. These interventions may also encourage school communities to identify and procure the delivery of other co-benefits from green infrastructure.

Numerical study of air pollution exposure in idealized urban street canyons: Porous and solid barriers

In this paper, it was considered the numerical modeling of concentration propagation using solid barriers and porous barriers of different heights in an idealized urban canyon to protect nearby houses. To solve this problem, a modification of the Reynolds-averaged Navier-Stokes equations was used to take into account the properties of the porous medium. To validate the mathematical model, a test problem was solved without taking into account various barriers. After validation, the main problem was solved, describing the process of pollutants emission between houses when using different types of vegetation barriers (solid and porous). All the obtained numerical results were compared with each other using different types of vegetation barriers. And the optimal porosity properties and permeability coefficient for vegetation barriers have been determined. So, from the obtained results, it can be noted that when using a solid green fence with a height of 0.1H, it was found that the concentration indicator significantly decreased compared to the results without barriers. But when comparing the indicators of the spread of the concentration with porous barriers after a height of 0.1H, a tendency to decrease in the maximum concentration is noticeable, but the average value of the concentration almost does not change.

Impact of China’s National Sword Policy on the U.S. Landfill and Plastics Recycling Industry

This paper analyzes the impacts of China’s Green Fence and National Sword Programs, under which strict contamination limits were imposed on recyclable materials, besides prohibiting imports of low quality recyclables. Specifically, this study investigates the impacts of this policy on landfills, and the risks to the U.S. plastics secondary materials market and material recovery facilities (MRFs). A hierarchical regression analysis reveals the significant impacts of China’s Green Fence and National Sword polices on the amount landfilled plastic. Controlling for oil prices, producer price index (PPI), and amount of plastic scrap exported, our findings show that the Green Fence had no statistically significant impact on the amount of plastic landfilled in the U.S. However, the quantity of plastic landfilled in the U.S. increased by 23.2% following the implementation of National Sword. Furthermore, analysis of the annual reports submitted by registered MRFs in New York (NY) state reveals that the total amount of plastic recovered by them has decreased. We suggest that demand creation and investments that improve the quality of bales are needed to help solve this economic dilemma.

Decontamination of Mixed Paper and Plastic Municipal Solid Waste Increases Low and High Temperature Conversion Yields

With the implementation of China’s Green Fence Policy and the following National Sword Policy, there is a need to divert previously accepted waste materials away from the landfill. Mixed plastic and paper wastes that are too contaminated to be economically recycled can be used for conversion into fuels and products. The effect of common contaminants present in waste streams must be determined to make municipal solid waste (MSW) a viable alternative to agricultural feedstocks for conversion. In this study, MSW was sourced from a dual stream materials recovery facility (MRF) in Emmet County, Michigan and characterized via mass balance. The most common contaminants in mixed paper and plastic were quantified and targeted for decontamination when mixed paper was explored for low temperature conversion pathways and plastics for high temperature conversion pathways. Ink, stickies, and plastic contamination were sorted out of the mixed paper stream and did not have an impact on sugar yields during enzymatic hydrolysis (EH). Although no improvement in yield was found, it was noted that copy paper within the mixed paper stream had an elevated pH and higher concentration of fermentation inhibitors, suggesting that intrinsic properties of some paper types may not be ideal for EH and fermentation conversion. Dilute alkaline pretreatment and mechanical refining of mixed paper increased the EH yield of mixed paper, suggesting this previously established process could be used as a decontamination method. “Dirt” and particulates were washed from mixed plastic using either an aqueous detergent or a non-aqueous chemical washing method. Liquid oil yields were increased during microwave assisted fast pyrolysis. All decontamination techniques met the cost target of less than $30/dry ton with plastic decontamination ranging from $18.16 to $24.81/dry ton. Because dilute alkaline pre-treatment and mechanical refining is considered part of the conversion process, the decontamination cost during feedstock preprocessing was considered $0/dry ton.

Light Quality Environment and Photomorphological Responses of Young Olive Trees

Tree densities have increased greatly in olive orchards over the last few decades. In many annual crop species, increased density reduces the horizontal red/far-red (R/FR) and blue/green (B/G) ratios during canopy development even before direct shading occurs, and such changes are known to alter plant morphology. This study with olive trees evaluated: (1) whether the leaf area index (LAI) of neighboring trees modifies the light quality environment prior to a tree being directly shaded and (2) the potential morphological responses of three olive cultivars to changes in light quality. Increasing LAI using different spatial arrangements of potted, three-year-old trees reduced the horizontal R/FR ratio more than that of the B/G ratio. Cultivar-specific responses to low R/FR ratio were observed for individual leaf area and aboveground/belowground biomass ratio using laterally positioned FR mirrors or green fences. No statistically significant responses were detected in response to green vegetation fences that reduced both horizontal R/FR and B/G ratios, but a cluster analysis grouped together the overall morphological responses to both FR mirrors and green fences. These results in olive trees suggest that cultivar differences in response to light quality may be relevant for understanding adaptation to dense orchards and identifying cultivars best suited to them.

Analysis of landscape areas on the territory of secondary school #19 of the city of Yoshkar-Ola

The research object is the territory of the secondary school #19 of the city of Yoshkar-Ola. The topicality of the research is determined by the necessity to reconstruct the existing landscape areas on this territory. For the project “The reconstruction of landscaped areas and improvements on the territory of the secondary school #19”, the authors have reviewed the landscaped areas. The analysis uses complete enumeration based on mensurational description. During the analysis, the authors defined species, taxonomic characteristics, sanitary and hygienic and esthetic values of each taxon. 290 woody plants were examined. Based on the acquired data, the authors analyzed the current landscaped areas on the territory and formulated the following conclusions: the density of plantations is much lower than the recommended values; the authors noticed only the traces of a green fence. However, the average values of the sanitary condition are 2 and 1, which means that the landscaped areas are in a good condition, and the species composition is in line with recommendations. Due to the fact that the school territory radius is 2 km, the condition of landscaped areas requires special attention. The scientific novelty of the research is determined by the fact that the landscaped areas on territory in question need to be reconstructed.   

The Impact of China’s Tightening Environmental Regulations on International Waste Trade and Logistics

In recent years, China’s influence as the dominant importer of waste products has reshaped global waste trade through restrictive programs such as Operation Green Fence in 2013 and National Sword in 2017. These restrictions have greatly affected not only China’s import of waste products but also the international trade and global logistics of these products. China’s import restrictions in 2017 decreased the country’s import of waste plastic by 92% and used paper by 56%. It also increased the unit value of these two categories of waste by 27% and 13%, respectively, showing an improvement in the quality of imported waste. Most of these impacts originate from intensive margins. The restrictions diverted the flow of waste mostly to the low- and middle-income countries of the East Asian and Pacific regions along with Europe and Central Asia, as their imports increased by 161% and 266% for waste plastic and 101% and 77% for used paper, respectively. Compared with Operation Green Fence, the impact of the 2017 National Sword has been much higher, with shipping companies faced with a lack of products on backhaul routes and forced to change their longstanding practices.

Implementasi Konvensi International Basel Terhadap Impor Sampah di Tiongkok

As a member of the Basel convention, China is committed to strictly limiting the import of plastic waste in order to maintain the quality of the country's environment. This study aims to determine and analyze the implementation of the Basel International Convention on handling waste imports in China. The research method used was a qualitative method with a descriptive approach. Data collection was carried out through literature review. The results show that the implementation of the Basel International Convention in handling waste imports in China has been successful, in terms of indicators of successful policy implementation, namely; content of policy and context of implementation. The implementation results show that China's policy of closing waste imports through the Green Fence Operation Policy and the National Sword Policy has a positive impact on reducing the amount of waste imports entering China. This decline has also affected changes in China's environment, be it water quality, air and those polluted by garbage. Although the changes still require a lot of improvement efforts, the success of implementation is also influenced by the Xi Jinping government regime which supports environmental reforms towards development progress with attention to ecological protection.

Scenarios for anthropogenic copper demand and supply in China: implications of a scrap import ban and a circular economy transition

Copper is widely used in buildings, transportation and home appliances, resulting in steadily increasing demand in China. From 2013 on, China has implemented the “Green Fence” policy to restrict copper scrap imports, which have affected and will continue to affect its future copper supply. To explore how China's copper demand can be met in the future, including the effects of the “Green Fence” policy change, in this paper a stock-driven approach is combined with a scenario analysis. We compare two scenarios (Continuity Policy, Circular Economy) and assess the influence of the “Green Fence” policy on each. We conclude that effective measures to prolong product lifetime could lead to a significant reduction in copper demand. Given the limited scope for domestic mining, China will still have to depend largely on imports of primary material in the form of concentrates and refined copper or, otherwise, put major emphasis on its recycling industry and continue to import high-quality copper scrap. In combination with the establishment of a state-of-the-art, efficient and environmentally friendly recycling industry, secondary copper could satisfy the bulk of Chinese copper demand and this could be an opportunity for China to transition to a more circular economy with regard to copper.

Evolution of the global polyethylene waste trade system

ABSTRACT Introduction China’s import bans on solid wastes starting from 2017 have challenged the global trade system of plastic wastes, which remains poorly characterized. This study chooses polyethylene (PE) as a case and aims to map out the global trade networks of PE waste (GPETN) from 1976 to 2017. Outcomes We find that the size and complexity of the GPETN had been growing until 2016. After the mid-1990s, PE waste basically flowed from developed economies, mainly the EU and the US, to developing economies such as China. Since 2001 when admitted into the WTO, China’s PE waste import surged until 2014 when it absorbed over 60% of global export. Regulations on solid waste import following the Green Fence campaign in 2013 resulted in substantial reductions in China’s import as well as the global export of PE waste after 2014. Several other developing economies, such as Malaysia, Turkey, and Vietnam, had transitioned to net importers, but their imports were insufficient to replace China as new recycling bases for PE waste. Conclusion The results highlight the urgent need of a joint effort for developed and developing countries to build a stronger global circular economy system with sufficient capacity to treat PE waste locally.

Fending off waste from the west: The impact of China's Operation Green Fence on the international waste trade

AbstractChina launched the first Operation Green Fence (OGF) on 1 February 2013 to fend off inflows of illegal waste. The main objective of OGF was to enforce waste trade policies already adopted by China and thereby restrict illegal waste imports. We use a gravity model of international trade with annual bilateral waste trade data at the 6‐digit HS code level to assess the impact of OGF on the international waste trade. First, we study the direct impact of OGF and find that the intervention resulted in a 26% drop in low‐quality waste exports to China from developed countries. Second, we assess the impact of OGF on exports from developed countries to developing countries, excluding China. We do not find a statistically significant effect of OGF on low‐quality waste exports from developed countries to developing countries (excluding China). We also test the waste haven hypothesis and do not find evidence that waste exports were disproportionately diverted to countries with lax environmental regulation.

Application of Hybrid Green Fences for Security in Public Building Designs in Nigeria: Lessons from Kigali, Rwanda and Abuja, Nigeria

Application of Hybrid Green Fences for Security in Public Building Designs in Nigeria: Lessons from Kigali, Rwanda and Abuja, Nigeria

The effect of border controls on waste imports: Evidence from China's Green Fence campaign

The international trade of waste has been an important and growing part of the global economy during the last two decades, which imposes regulatory challenges to governments in the South to protect the environment. This paper investigates the effect of border controls with a difference-in-difference design by exploiting a unique natural experiment, China's Operation Green Fence (OGF) implemented in 2013. We find that the OGF exerted a significant deterrent effect on the waste imported into China. Specifically, we find that the import weight of waste grew by 9.48 percentage less and the import price declined by 7.6 percentage more compared to those of the non-waste. The results are robust to a series of robustness checks, and there is no similar reaction in other regions, where the OGF was not initiated.

Managing Marine Plastic Pollution: Policy Initiatives to Address Wayward Waste

A few times a year, volunteers fan out along the causeway that links the South Carolina mainland with the seashore community of Folly Beach to clean up plastic bottles, straws, bags, and other debris from along the road and the salt marsh. Some of this debris has come from cities miles away. On windy days, litter is often blown off city streets into waterways. During rainstorms, debris floats into drains that empty into rivers. Other trash probably came from places closer to home. “I see bags and other plastic flying off the beds of pickup trucks going down the causeway,” says Marty Morganello, who organizes the cleanups for the Charleston-area chapter of the nonprofit Surfrider Foundation. “I see them coming out the open windows of cars and out the backs of garbage trucks and even recycling trucks. This material is lightweight, and if you don’t secure it, it will fly away.” By one estimate, the volume of plastic debris going into the world’s oceans could more than double by 2025, assuming current trends in coastal development and plastics use. Some countries have begun identifying ways to improve management of plastic ... Beach cleanups yield enormous amounts of trash, with plastic items a major constituent.1 Although the human health impacts of this marine plastic pollution remain poorly characterized, it is widely seen as an emerging problem that deserves much more research attention.2 Likewise, there is a growing urgency among industry, government, nongovernmental organizations, and environmental groups to develop tools and policies to track, capture, and recycle plastic waste before it reaches the ocean.

Correlation between dichromatic colour vision and jumping performance in horses

There is general agreement that horses have dichromatic colour vision with similar capabilities to human beings with red–green colour deficiencies. However, whether colour perception has an impact on equine jumping performance and how pronounced the colour stimulus might be for a horse is unknown. The present study investigated the relationship between the colour of the fences (blue or green) and the show jumping performance of 20 horses ridden by two riders using an indoor and outdoor set of green and blue fences.In the indoor arena, significantly more touches and faults were made on blue fences in comparison to green fences (median difference of 2.5 bars). When only touched bars were included, a significant median difference of one bar was found. Mares (n = 4) demonstrated more faults and had a significantly greater difference in touches and faults between the two colours than male horses (n = 16). Repeating the same experiment with eight horses in an outdoor grass arena revealed no significant differences between the two colours. In order to draw any definite conclusions, more research concerning the colour perception, influence of contrast with the arena surface and sex of horse is required.

The Green Fence of Chinese Hibiscus (Hibiscus rosa-sinensis L.) Prevents Pollen Dispersal of Transgenic Rice (Oryza sativa)

Transgene escape mediated by pollen dispersal is one of the preeminent concerns about genetically modified crops, including rice. In this study, the rice pollen donor of non-glutinous Oryza sativa ssp. japonica cv. ‘Tainung 67’ [TNG 67] had a greater potential of pollen flow, which was shown by the greater quantity, germination rate, and viability of pollen, than the other rice pollen donor of transgenic AAN. The pollen-mediated gene flow was detected by the frequency of outcrossed seeds in a “checker-board pattern” and alternating row arrangement of rice pollen donor (TNG 67 or AAN) and pollen recipient (glutinous rice ‘TNG 73’) in the fields. We conducted field experiments to assess rice pollen dispersal with or without a “green” fence of Chinese hibiscus, Hibiscus rosa-sinensis L., of approximately 2 m in height and 0.6 m in thickness. Without a green fence, the outcrossing rate of TNG 73 seeds decreased with increasing distance from the pollen donor, from 1.68% at 1 m to 0.01% at 35 m, with no outcrossing beyond 40 m. The outcrossing rate varied with the direction of pollen donor, from 0.05% in the northeastern direction to 0.78% in the southern direction, which was caused by prevailing wind direction. With the green fence, no seeds of TNG 73 were outcrossed. Since a buffer zone of at least 40 m is needed to prevent outcrossing of rice by pollen dispersal in an open field, planting of Chinese hibiscus around the rice field as a green fence would be an effective measure for preventing transgene escape mediated by pollen flow.

The Japanese house: material culture in the modern home

Acknowledgments Chapter 1 INTRODUCTION SPREAD 1: Map with locations and images of exteriors of the homes studied Chapter 2 HOMES INSIDE OUT Gates, fences and walls 'We would rather have nice English garden' 'Everyone needs garage' Between the window and the hallway Red buckets and neighbourhood cooperation Local communities of limited liability Conclusion: The inside out SPREAD 2: Street gardens green fences and terracotta walls SPREAD 3: Wifely duties and neighbourhood surveillance Chapter 3 FEELING AT HOME 'The pleasures of happy home' From tatami to chair-based living The postwar 'LDK home': 1. The sofa and dining table 2. Double beds 'Bathing is my way to relax' Tatami mats 'A space to relax' Conclusion: Affectionate ties SPREAD 4: The choreography of domestic slippers Chapter 4 TATAMI TASTES Male domestic taste and sophistication Full-time and part-time housewives A national domestic taste? Eclectic alcoves 'New is better': traditional and modern aesthetics Male minimal design The exception: modern aesthetic scheme 'We have a son in box ' Male domestic stereotypes: 'Japanese fathers have no holidays' Do-it-Yourself Conclusion: Gender stereotypes SPREAD 5: Alcoves half full or half empty? Chapter 5 STUFF AND STORAGE The ideology of tidiness Storehouse living: circulation and accumulation Storage strategies: 1. Expanding the home 2. 'Living among one's furniture' Furniture walls Dowries and provisioning The contemporary starter home Life cycle rupture points: 'if I had house like castle, I would take everything' Conclusion: Conduits and containers SPREAD 6: Women and their kimono SPREAD 7: Destroying and rebuilding the family home Chapter 6 TROUBLESOME THINGS Domestic disarray? Souvenir Cabinets: objects frozen in time and space Troublesome Things Commemorative gifts and unique relationships Ephemeral gifts and the renewal of relationships Surplus, divestment and informal sociality Conclusion: pressures and constraints of gift culture SPREAD 8: The Dolls Festival SPREAD 9: Bazaars and flea markets Chapter 7 THE LOCUS OF SPIRITUAL IN THE DOMESTIC The house-building ceremony The domestic cycle of 'annual events' God shelves and auspiciousness The temporality of luck Affective and material bonds with the ancestors A son's duty of care? Inter-generational tensions New family models Conclusion: Causality and self-determination SPREAD 10: Religion as action Chapter 8 CONCLUSION Notes Bibliography Index

RESEARCH REGARDING THE PROPAGATION OF SOME DECIDUOUS SHRUBS USED FOR GREEN FANCES

,The research where carried out in the greenhouse experimental plots afferent to the Flower and Arboriculture Department, Faculty of Horticulture, University of Agricultural Science and Veterinary Medicine Cluj-Napoca The biological material taken into study was represented by cuttings provided by species Buxus sempervirens, Ligustrum vulgare and Ligustrum ovalifolium var. aureo-variegata. The cuttings have been collected after the green fence cuts made in the USAMV Park Cluj-Napoca. The experimental factors where: root substrate (Perlit 100%, Perlit 50% + Peat 50%), used species (Buxus sempervirens, Ligustrum vulgare, Ligustrum ovalifolium var. aureo-variegata), rooting regulator: Radistim 2. The tree factors where divided in tree repetitions. During the experiment the following observations where made: length of cuttings (cm), no. of leafs, diameter at the cutting base (mm), no. of nodes, no. of cuttings with root system, no. of roots/cutting, the length of the root (cm), the length of the root system (cm). Before root beginning at each species where made the following determinations: origin of the cuttings, length (cm), and no. of leafs, diameter at the base of cutting, no. of nodes. The main characteristics of the cuttings taken into study are in concordance with each species studied.