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311.
David G. Angeler Craig R. Allen Ahjond S. Garmestani Lance H. Gunderson Igor Linkov 《The Environmentalist》2016,36(3):225-228
Environmental sciences have an important role in informing sustainable management of built environments by providing insights about the drivers and potentially negative impacts of global environmental change. Here, we discuss panarchy theory, a multi-scale hierarchical concept that accounts for the dynamism of complex socio-ecological systems, especially for those systems with strong cross-scale feedbacks. The idea of panarchy underlies much of system resilience, focusing on how systems respond to known and unknown threats. Panarchy theory can provide a framework for qualitative and quantitative research and application in the environmental sciences, which can in turn inform the ongoing efforts in socio-technical resilience thinking and adaptive and transformative approaches to management. 相似文献
312.
Aaron Kempf Craig E. Divine Gastón Leone Stacy Holland John Mikac 《补救:环境净化治理成本、技术与工艺杂志》2013,23(1):37-61
Conventional methods to estimate groundwater velocity that rely on Darcy's Law and average hydrogeologic parameter values are insensitive to local‐scale heterogeneities and anisotropy that control advective flow velocity and direction. Furthermore, at sites that are tidally influenced or have extraction wells with variable pumping schedules, infrequent water‐level measurements may not adequately characterize the range and significance of transient hydraulic conditions. The point velocity probe (PVP) is a recently developed instrument capable of directly measuring local‐scale groundwater flow velocity and direction. In particular, PVPs may offer distinct advantages for sites with complex groundwater–surface water interactions and/or with spatially and temporally variable groundwater flow conditions. The PVP utilizes a small volume of saline tracer and inexpensive sensors to directly measure groundwater flow direction and velocity in situ at the centimeter‐scale and discrete times. The probes are installed in conventional direct‐push borings, rather than in wells, thus minimizing the changes and biases in the local flow field caused by well installation and construction. Six PVPs were installed at a tidally influenced site in North Carolina to evaluate their implementability, performance, and potential value as a new site characterization tool. For this study, a new PVP prototype was developed using a rapid prototyping machine (i.e., a “three‐dimensional printer'') and included both horizontally and vertically oriented tracer detectors. A site‐specific testing protocol was developed to account for the spatially and temporally variable hydraulic conditions and groundwater salinity. The PVPs were tested multiple times, and the results were compared to the results of several different groundwater flux and velocity estimation tools and methods, including a heat‐pulse flowmeter, passive flux meters, single‐well tracer tests, and high‐resolution hydraulic gradient analysis. Overall, the results confirmed that the PVP concept is valid and demonstrated that reliable estimates of groundwater velocity and direction can be obtained in simple settings. Also, PVPs can be successfully installed by conventional methods at sites where the formation consists primarily of noncohesive soils and the water table is relatively shallow. Although some PVP tests yielded consistent and reliable results, several tests did not. This is likely due to the highly transient flow conditions and limitations associated with the PVP design and testing procedures. PVPs offer particular advantages over, and can effectively complement, other groundwater flow characterization techniques for certain conditions, and objectives may be useful for characterizing complex flow patterns under steady conditions; however, this study suggests that PVPs are best suited for conditions where the flow hydraulics are not highly transient. For sites where the hydraulic conditions are highly transient, the most reliable approach for understanding groundwater flow behavior and groundwater–surface water interactions would generally involve both a high‐resolution hydraulic gradient analysis and another local‐scale method, such as tracer testing. This study also highlighted some aspects of the current PVP design and testing protocol that can be improved upon, including a more robust connection between the PVP and injection line and further assessment of tracer solution density effects on vertical flow. © 2013 Wiley Periodicals, Inc. 相似文献
313.
Work-contingent self-esteem (WCSE; the degree to which workers' self-esteem is based on workplace performance) has positive consequences for performance, yet less is known about its consequences for well-being. In this paper, we contribute to the literature on WCSE by examining the mechanisms through which it impacts well-being at work and outside of work. We challenge contingent self-esteem (CSE) theory (Crocker & Park, 2004), which argues that CSE negatively impacts well-being by fostering internally controlled (introjected) motivation and diminishing autonomous motivation, by suggesting that WCSE fosters autonomous and internally controlled motivation and thus has both beneficial and harmful effects on well-being. We also expand CSE theory by suggesting that WCSE can negatively impact well-being outcomes by causing work–nonwork conflict. Results from a time-separated design in a sample of full-time employees supported our arguments, revealing that WCSE impacted well-being at work through both autonomous and internally controlled work motivations. WCSE also had negative effects on well-being at and outside of work through work–nonwork conflict. The beneficial effects of WCSE outweighed its harmful effects on job satisfaction and neutralized its harmful effects for all other outcomes. We discuss theoretical implications for CSE theory, self-determination theory, and work–nonwork issues and note important practical implications. 相似文献
314.
This article will briefly outline the origins, structure and functions of United Nations Environment Program and the Commission on Sustainable Development in the context of the goals of ecologically sustainable development (ESD). Economic development, social development and environmental protection form the three interconnected parts of ESD. The achievements of the key UN environmental institutions and programs in opening up the global system to civil society, the private sector and a diversity of actors and interests, promoting the role of poverty alleviation as part of ESD through the Millennium Development Goals, and facilitating important Multilateral Environmental Agreements should be recognized. However, with these notable exceptions, organizations such as United Nations Environment Program and the Commission on Sustainable Development have become weak in scientific and technical leadership, global policy, co-ordination (inside and outside the UN) and has few achievements in the inter- national and national implementation of obligations and standards in Global Environmental Governance - including enforcement, compliance and effectiveness. This article will outline the key reasons for this inadequacy. Attention will also be focused on the way forward through of a new United Nations Environment Organization. This will require a clarification of purpose and function (within the UN system and as part of global governance structures) as well as consideration of whether it depends on system-wide UN reform. It is recommended that medium and long term strategies for reform are necessary. 相似文献
315.
Enforced institutional settings such as penitentiaries provide environments to raise awareness, carry out research, and implement
and assess practices for sustainable living. Institutions where residence is enforced due to health, recreational, military,
or legal reasons (e.g., assisted living centers, summer camps, army bases, prisons) house people who may lack scientific training
but have time and need for intellectual stimulation that can be filled by supervised research. These institutions have stable
populations, structured social organization, and measurable inputs and outputs of materials and energy to carry out sustainable
practices in tasks that affect regional resources such as groundwater quality and landfill use. We report on three examples
at a corrections center resulting from partnerships among visiting academic ecology researchers, sustainability practitioners,
corrections administrators, and prisoners: (1) research on how to sustainably “farm” moss for the horticulture trade to reduce
harvesting pressure on wild moss populations; (2) a vermiculture and thermophilic composting system to reduce the kitchen
waste; and (3) a monthly seminar series at the prison. Over 26 months: (1) participants developed methods to optimize moss
growth; (2) landfill-bound waste and particulate flow rate destined for wastewater treatment decreased by 50%, to less than
50% of permit limits; (3) resulting compost (ca. 5000 kg) fertilized institutional vegetable gardens; (4) water quality improved
so that the prison could return funds allocated to upgrade the prison’s water quality. The lectures encouraged intellectual
exchange among researchers, convicts, and guards. Researchers derived new perspectives and broader impacts for their work.
This can be a model for other correctional facilities and other enforced residential institutions (ERIs).
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
316.
Cheng-Yuan Xu Kevin L. Griffin Elizabeth C. Craig Sanpisa Sritrairat Marco J. Castaldi 《Environmental pollution (Barking, Essex : 1987)》2009,157(7):2118-2125
Although post-combustion emissions from power plants are a major source of air pollution, they contain excess CO2 that could be used to fertilize commercial greenhouses and stimulate plant growth. We addressed the combined effects of ultrahigh [CO2] and acidic pollutants in flue gas on the growth of Alternanthera philoxeroides. When acidic pollutants were excluded, the biomass yield of A. philoxeroides saturated near 2000 μmol mol−1 [CO2] with doubled biomass accumulation relative to the ambient control. The growth enhancement was maintained at 5000 μmol mol−1 [CO2], but declined when [CO2] rose above 1%, in association with a strong photosynthetic inhibition. Although acidic components (SO2 and NO2) significantly offset the CO2 enhancement, the aboveground yield increased considerably when the concentration of pollutants was moderate (200 times dilution). Our results indicate that using excess CO2 from the power plant emissions to optimize growth in commercial green house could be viable. 相似文献
317.
Jill S. Baron Lance Gunderson Craig D. Allen Erica Fleishman Donald McKenzie Laura A. Meyerson Jill Oropeza Nate Stephenson 《Environmental management》2009,44(6):1033-1042
Past and present climate has shaped the valued ecosystems currently protected in parks and reserves, but future climate change
will redefine these conditions. Continued conservation as climate changes will require thinking differently about resource
management than we have in the past; we present some logical steps and tools for doing so. Three critical tenets underpin
future management plans and activities: (1) climate patterns of the past will not be the climate patterns of the future; (2)
climate defines the environment and influences future trajectories of the distributions of species and their habitats; (3)
specific management actions may help increase the resilience of some natural resources, but fundamental changes in species
and their environment may be inevitable. Science-based management will be necessary because past experience may not serve
as a guide for novel future conditions. Identifying resources and processes at risk, defining thresholds and reference conditions,
and establishing monitoring and assessment programs are among the types of scientific practices needed to support a broadened
portfolio of management activities. In addition to the control and hedging management strategies commonly in use today, we
recommend adaptive management wherever possible. Adaptive management increases our ability to address the multiple scales
at which species and processes function, and increases the speed of knowledge transfer among scientists and managers. Scenario
planning provides a broad forward-thinking framework from which the most appropriate management tools can be chosen. The scope
of climate change effects will require a shared vision among regional partners. Preparing for and adapting to climate change
is as much a cultural and intellectual challenge as an ecological challenge. 相似文献
318.
Su T Shu S Shi H Wang J Adams C Witt EC 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):944-950
This study provided a comprehensive assessment of seven toxic trace elements (As, Pb, V, Cr, Cd, Cu, and Hg) in the soil/sediment of Katrina affected greater New Orleans region 1 month after the recession of flood water. Results indicated significant contamination of As and V and non-significant contamination of Cd, Cr, Cu, Hg and Pb at most sampling sites. Compared to the reported EPA Region 6 soil background inorganic levels, except As, the concentrations of other six elements had greatly increased throughout the studied area; St. Bernard Parish and Plaquemines Parish showed greater contamination than other regions. Comparison between pre- and post-Katrina data in similar areas, and data for surface, shallow, and deep samples indicated that the trace element distribution in post-Katrina New Orleans was not obviously attributed to the flooding. This study suggests that more detailed study of As and V contamination at identified locations is needed. 相似文献
319.
Effects of ionic strength, temperature, and pH on degradation of selected antibiotics 总被引:9,自引:0,他引:9
Aqueous degradation rates, which include hydrolysis and epimerization, for chlortetracycline (CTC), oxytetracycline (OTC), tetracycline (TET), lincomycin (LNC), sulfachlorpyridazine (SCP), sulfadimethoxine (SDM), sulfathiazole (STZ), trimethoprim (TRM), and tylosin A (TYL) were studied as a function of ionic strength (0.0015, 0.050, or 0.084 mg/L as Na(2)HPO(4)), temperature (7, 22, and 35 degrees C), and pH (2, 5, 7, 9, and 11). Multiple linear regression revealed that ionic strength did not significantly affect (alpha = 0.05) degradation rates for all compounds, but temperature and pH affected rates for CTC, OTC, and TET significantly (alpha = 0.05). Degradation also was observed for TYL at pH 2 and 11. No significant degradation was observed for LNC, SCP, SDM, STZ, TRM, and TYL (pH 5, 7, and 9) under study conditions. Pseudo first-order rate constants, half-lives, and Arrhenius coefficients were calculated where appropriate. In general, hydrolysis rates for CTC, OTC, and TET increased as pH and temperature increased following Arrhenius relationships. Known degradation products were used to confirm that degradation had occurred, but these products were not quantified. Half-lives ranged from less than 6 h up to 9.7 wk for the tetracyclines and for TYL (pH 2 and 11), but no degradation of LIN, the sulfonamides, or TRM was observed during the study period. These results indicate that tetracyclines and TYL at pH 2 and 11 are prone to pH-mediated transformation and hydrolysis in some cases, but not the sulfonamides, LIN nor TRM are inclined to degrade under study conditions. This indicates that with the exception of CTC, OTC, and TET, pH-mediated reactions such as hydrolysis and epimerization are not likely removal mechanisms in surface water, anaerobic swine lagoons, wastewater, and ground water. 相似文献
320.
Craig A. Stow Leland J. Jackson S. R. Carpenter 《Environmental monitoring and assessment》1999,55(3):435-444
We introduce a generalized form of the common first-order (exponential) decay model, that has potential utility for describing contaminant declines in environmental applications, particularly when declines are a mixture of many underlying processes. The exponent on contaminant concentration is left as a free parameter allowing the order of the reaction to be determined by the data. The mixed-order model is more flexible than models with the exponent determined a priori, facilitating an improved fit to observed behavior. We demonstrate the utility of this model, and compare it to two other models, by estimating PCB concentration declines in Lake Michigan fishes. 相似文献