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Identifying the deleterious ecological effects of developments, such as roads, mining, and urban expansion, is essential for informing development decisions and identifying appropriate mitigation actions. However, there are many t...
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Identifying the deleterious ecological effects of developments, such as roads, mining, and urban expansion, is essential for informing development decisions and identifying appropriate mitigation actions. However, there are many types of ecological impacts that slip 'under the radar' of conventional impact evaluations and undermine the potential for successful impact mitigation (including offsets). These 'enigmatic' impacts include those that are small but act cumulatively; those outside of the area directly considered in the evaluation; those not detectable with the methods, paradigms, or spatiotemporal scales used to detect them; those facili-tated, but not directly caused, by development; and synergistic impact interactions. Here, we propose a framework for conceptualising enigmatic impacts and discuss ways to address them.
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The theoretical connections between off-site construction (OSC) and lean have only been marginally addressed in existing literature. This study analyses how distinct OSC strategies (1) affect flow and completion times, and (2) sup...
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The theoretical connections between off-site construction (OSC) and lean have only been marginally addressed in existing literature. This study analyses how distinct OSC strategies (1) affect flow and completion times, and (2) support simplification in construction (by reducing the number of parts and/or steps). Flow, which entails the smooth and reliable transfer of work across trades, is at the heart of lean whereas simplification is one principle of this management philosophy. Industry data based on three residential projects built in Australia using traditional construction or OSC strategies (panels/cassettes, and/or bathroom pods), and 15 hypothetical scenarios were used to develop a simulation exercise. The results show that OSC can substantially reduce schedule durations, particularly when different prefab elements are jointly used, but flow variability [measured by coefficient of variation (COV)] remains unchanged when compared to traditional construction. OSC was found to minimize the number of parts on-site by having building materials and components aggregated off-site and delivered as subassemblies. Yet, the number of steps did not reduce substantially, and the reductions only occurred when panels/cassettes were used. Alternative perspectives explaining the numerical results obtained are also discussed. The main contribution of this paper lies in measuring the impact of distinct OSC strategies from a flow viewpoint as well as in empirically examining their benefits from a simplification viewpoint. The study extends existing knowledge by leveraging industry data to quantify such impacts utilizing a tailored simulation approach. This provides an important addition to the still limited number of investigations measuring and comparing flow under different conditions.
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Although the mining industry provides minerals and metals to the global market and represents important economic opportunities, it also constitutes a major anthropogenic disturbance in the ecosystems where it takes place. However,...
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Although the mining industry provides minerals and metals to the global market and represents important economic opportunities, it also constitutes a major anthropogenic disturbance in the ecosystems where it takes place. However, little is known about its offsite impacts on plant communities. We assessed the frequency and the abundance of five common boreal understorey plant species (Coptis trifolia (L.) Salisb., Cornus canadensis L., Linnaea borealis L., Lysimachia borealis (Raf.) U.Manns & Anderb., and Maianthemum canadense Desf.) at different distances around six mines in Abitibi-Temiscamingue and Nord-du-Quebec (Quebec). Frequency and (or) abundance of Coptis trifolia and M. canadense decreased near mines, suggesting that they might be sensitive to the loss of forest cover, particle deposition, and soil contamination induced by mining. Conversely, the frequency and abundance of Cornus canadensis increased near active mines, which indicates its resilience to the stress caused by mines and its ability to exploit the niche space left by more sensitive species. No effects on Linnaea borealis and Lysimachia borealis were observed. Our study suggests the possible presence of offsite impacts of mines on plant communities. Further studies considering enigmatic impacts should be conducted in order to develop our understanding of the broader environmental footprint of mining activity.
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This study examined the comparability of onsite and offsite methods for measuring norms for trail impacts using photo/survey techniques. A total of 449 subjects participated in a study of Mudeung-Mountain Provincial Park, Gwa...
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This study examined the comparability of onsite and offsite methods for measuring norms for trail impacts using photo/survey techniques. A total of 449 subjects participated in a study of Mudeung-Mountain Provincial Park, Gwang-Ju, Korea. For the overall photo evaluation method (OPEM), respondents rated the accept-
ability of bare soil area for each of a series of photographs. For the specific photo evaluation method (SPEM), respondents selected a photograph that illustrated the largest acceptable proportion of bare soil area from a series of 10 photographs. Overall, there were no substantial differences in maximum acceptable impacts between onsite (onsite-l visitor group surveyed at the actual trail points and onsite-l I departing visitor group surveyed at the exit area) and offsite (students surveyed in a laboratory setting) groups for the two norm measurement alternatives (OPEM and SPEM). Subjects' difficulty ratings were low for both methods, and there were no substantial differences in norms between individuals with high and low levels of experience at the park. The offsite method appears to be substitutable for onsite methods in this particular study area, which is a frontcountry setting with a relatively simple range of recreation opportunities. Implications and further studies are discussed.
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Offsite construction has been identified as an effective approach for enhancing the sustainability of the construction industry. However, due to the fragmented production processes of offsite construction, quality defect control h...
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Offsite construction has been identified as an effective approach for enhancing the sustainability of the construction industry. However, due to the fragmented production processes of offsite construction, quality defect control has become a significant challenge in the promotion of offsite construction projects. Offsite construction projects involve multiple interdependent stakeholders in close collaboration. These stakeholders play various roles in quality management and have different degrees of impact on the occurrence of quality defects. To enhance quality defect management in offsite construction projects, it is important to evaluate the different stakeholder impacts on the occurrence of quality defect. Through impact evaluations, critical stakeholders can be identified and their responsibilities clarified with respect to project quality, thereby motivating these key stakeholders to improve their quality defect control. In this study, we developed an evaluation model using the Bayesian network approach to measure stakeholder impacts on defect occurrence in offsite construction projects. Quality defects and stakeholder-related factors that might incur defects were modeled as a Bayesian network and the dependencies among network nodes examined. Then, the stakeholder impacts on the occurrence of quality defects were evaluated using Bayesian analysis. Finally, this Bayesian-network-based evaluation model was applied to a real project in Shenzhen, China. The results indicate that use of precast components with quality defects, misoperations by construction workers, and ineffective quality inspection and testing during onsite assembly and construction were the major factors affecting quality defect control. Additionally, in this case study, we found the contractor to have the highest level of impact on the occurrence of quality defects. This study contributes to the fields of stakeholder impact evaluation and quality defect analysis, and links defect management with key project stakeholders. (C) 2019 Elsevier Ltd. All rights reserved.
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Context The acceleration of infrastructure development presents many challenges for the mitigation of ecological impacts. The type, extent, and cumulative effects of multiple developments must be quantified to enable mitigation.
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Landfill leachate is commonly treated offsite with municipal wastewater. This offsite leachate treatment may be limited or no longer applicable due to the increasingly stringent regulations and concerns related to per- and polyflu...
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Landfill leachate is commonly treated offsite with municipal wastewater. This offsite leachate treatment may be limited or no longer applicable due to the increasingly stringent regulations and concerns related to per- and polyfluoroalkyl substance (PFAS) discharge into the environment, resulting in development of full-scale, onsite leachate treatment facilities. To help landfills prepare for the potential shift from offsite to onsite leachate treatment for PFAS compliance, this study analyzed and compared the environmental, human health, and economic performances of a typical onsite and a typical offsite leachate treatment alternative through life cycle assessment (LCA) and life cycle cost assessment (LCCA) using a landfill site located in Zhuzhou, China as a testbed. Two distinct functional units (FUs) were investigated: 1 m3 of leachate treated and 1 g of PFAS removed. Our results show that the onsite scenario offered benefits from human health and economic perspectives, while the offsite scenario generally performed better from the environmental perspective when a leachate PFAS concentration of 150,704 ng/L was assumed. The extent of this tradeoff varied when different functional units were adopted. The onsite scenario will not be competitive from all three perspectives when PFAS concentration in the raw leachate is less than 1666 ng/L.
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