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91.
92.
Keith G. Tidball 《Sustainability Science》2016,11(6):867-876
Social-ecological traps are theorized to be present when human actions affect feedbacks and drivers in social-ecological systems, which, in turn, lead to regime shifts that may alter ecosystem capacity to generate services on which human wellbeing depends, and this, in turn, triggers societal responses, where actors and institutions interact with ecological dynamics and unwittingly lock development into a vulnerable pathway. The key dynamic in this theorization seems to be that human action often predicates or initiates the series of cascading affects that determine the presence of, and, perhaps, the effectiveness of, social-ecological traps. However, what drives human action in this context? What logic, assumptions, decisions, world views, and other processes are implicated in this configuration? This paper first briefly reviews ecological identity and the problems of anthropocentricism, human exceptionalism, and human exemptionalism and introduces the term ecological disenfranchisement. Building upon this, the author invokes Horn’s logic and dialectical traps as a lens for understanding human roles and the prevalence of issues with ecological identities, within social ecological traps. Drilling further down, the paper illustrates these traps with short vignettes, in each case, attempting to link the human logical traps with larger system dynamics. Finally, the author proposes a chain of reasoning to serve as an example of how the presence of human logic traps (or entrapment) in a number of different spheres has an impact upon the larger system, and, perhaps, even predicts entrapment of the larger system. Future efforts to either understand social-ecological traps or navigate away or out of them must first take stock of the human logical traps that actors within the systems are influenced by, and that influence the large system(s).This paper argues that failing to account for human traps within will render most efforts to avoid or escape social-ecological traps futile. 相似文献
93.
M. Reza Ghanbarpour Keith William Hipel 《Environment, Development and Sustainability》2009,11(2):241-253
Environmental disputes arise due to opposing views of various groups about their environmental concerns and their economic
or developmental interests. Development and protection of the environment constitute two main contradictory objectives within
the sustainable development paradigm, which are often in conflict. The decision support system, GMCR II, which implements
the graph model for conflict resolution, is employed to model and analyze an environmental dispute arising over the construction
of a new freeway between the Iranian capital, Tehran, and the city of Chalous located in the north of the country. This study
demonstrates that the graph model for conflict resolution can be used as a methodology to promote a reasonable balance between
economic development and environmental protection from a strategic viewpoint. In addition to systematically modelling the
conflict by putting the existing information into proper perspective, it is shown how conflict analysis can be used for comparing
alternative scenarios and predicting possible future outcomes.
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
94.
Association of plutonium with sediments from the Ob and Yenisey Rivers and Estuaries 总被引:1,自引:0,他引:1
Lindis Skipperud Justin Brown L. Keith Fifield Deborah H. Oughton Brit Salbu 《Journal of environmental radioactivity》2009
The present study applied sequential extraction techniques to investigate the binding and mobility of plutonium (Pu) in sediments from the rivers and estuaries of the Ob and Yenisey. As a study site, the Ob and Yenisey are particularly interesting as both rivers have weapons-grade Pu sources in their catchment areas, including the Russian Pu production and reprocessing plants at Mayak, Tomsk-7 and Krashnoyarsk, and the Semipalantinsk nuclear weapons testing site in Kazakhstan. Plutonium activity and 240Pu/239Pu ratios were determined using accelerator mass spectrometry (AMS). Sequential extractions showed that between 47 and 80% of the Pu in Yenisey River sediments and 35–53% of the Pu in soils around the Techa River are mobilized with weak oxidising agents, which can indicate that Pu is bound to organic material. In contrast, Pu in Ob and Yenisey Estuarine sediments was more strongly bound, with 60–100% being found in the HNO3-extractable fraction. This change in speciation could reflect either that Pu bound to organic material in the Techa and Yenisey River sediments becomes more fixed to the sediments with time, or that organic-bound Pu is mobilized and released to the water when the sediments encounter the more saline water of the Ob and Yenisey estuaries. In general, 240Pu/239Pu ratios were relatively consistent between different extraction fractions, although, in whole sediments, an increase in ratio was observed with distance from the source. This reflects the increased influence of weapon fallout from catchment runoff within the river systems, as compared to the weapons-grade sources close to the production and reprocessing plants. Knowledge of Pu speciation in the Ob and Yenisey Rivers, and the processes controlling its behaviour in estuarine systems, can improve predictions of its transfer and subsequent environmental impact to Arctic Seas. 相似文献
95.
This paper reports the preparation and properties of a new low density granular absorbent material based on a zeolite/vermiculite composite. The composite prepared addresses a number of important issues relating to the use of zeolites in environmental and waste management applications. The material prepared has large particle size due to binderless adhesion of zeolite crystals within the protective lamellar matrix provided by the vermiculite granule. Additionally, the porous nature of new material ensures that it outperforms natural zeolite grains in ion-exchange tests. The material was shown to have a low bulk density (0.75 g cm(-3)) adding the benefit that the majority of grains float on water for over 15 h. The conclusion of the study is that the use of composite matrices enable the preparation of materials which show the physical properties of the host, (e.g., granular and low density), whilst maintaining the powder-like properties (e.g., high ion-exchange and small crystal size) of the active component. The resulting material can be easily handled and separated from aqueous waste streams using either flotation or exploiting its granular nature. 相似文献
96.
PROBLEM: Unsafe driving and passenger behaviors place teens at increased risk for fatal and nonfatal crashes. This study evaluated the short-and long-term efficacy of the You Hold the Key (YHTK) Teen Driving Countermeasure. METHOD: A two-page survey was completed by high school students at pretest, posttest, and long-term (6-month) posttest. RESULTS: YHTK was associated with significant immediate and long-term improvements in teen seatbelt use, safe driving, and perceived confidence in preventing drunk driving. Compared to pretests, students at immediate and long-term posttest more frequently wore seatbelts when driving or riding, required passengers to wear seatbelts, and limited the number of passengers to the number of seatbelts in the vehicle. Students were more likely at both posttests to avoid drinking and driving and to say no to riding with a friend who had been drinking. SUMMARY: YHTK was associated with increases in safe teen driving and passenger behaviors. IMPACT ON INDUSTRY: Success of YHTK is most notably due to its comprehensive nature. Future programs should consider comprehensive strategies when attempting to modify teen behaviors. 相似文献
97.
Thomas Minning Darren A. Lytle Maily Pham Keith Kelty 《Environmental monitoring and assessment》2015,187(6):383
Distinguishing between soluble and particulate lead in drinking water is useful in understanding the mechanism of lead release and identifying remedial action. Typically, particulate lead is defined as the amount of lead removed by a 0.45-μm filter. Unfortunately, there is little guidance regarding selection of filter membrane material and little consideration to the possibility of the sorption of dissolved lead to the filter. The objective of this work was to examine the tendency of 0.45-μm syringe filter materials to adsorb lead. Tests were performed with water containing 40 and 24 μg/L soluble lead at pH 7 buffered with 50 mg C/L dissolved inorganic concentration (DIC). The amounts of lead sorbed greatly varied by filter, and only two filter types, polypropylene and mixed cellulose esters, performed well and are recommended. Great care must be taken in choosing a filter when filtering soluble lead and interpreting filter results. 相似文献
98.
Assessments of risk to biodiversity often rely on spatial distributions of species and ecosystems. Range‐size metrics used extensively in these assessments, such as area of occupancy (AOO), are sensitive to measurement scale, prompting proposals to measure them at finer scales or at different scales based on the shape of the distribution or ecological characteristics of the biota. Despite its dominant role in red‐list assessments for decades, appropriate spatial scales of AOO for predicting risks of species’ extinction or ecosystem collapse remain untested and contentious. There are no quantitative evaluations of the scale‐sensitivity of AOO as a predictor of risks, the relationship between optimal AOO scale and threat scale, or the effect of grid uncertainty. We used stochastic simulation models to explore risks to ecosystems and species with clustered, dispersed, and linear distribution patterns subject to regimes of threat events with different frequency and spatial extent. Area of occupancy was an accurate predictor of risk (0.81<|r|<0.98) and performed optimally when measured with grid cells 0.1–1.0 times the largest plausible area threatened by an event. Contrary to previous assertions, estimates of AOO at these relatively coarse scales were better predictors of risk than finer‐scale estimates of AOO (e.g., when measurement cells are <1% of the area of the largest threat). The optimal scale depended on the spatial scales of threats more than the shape or size of biotic distributions. Although we found appreciable potential for grid‐measurement errors, current IUCN guidelines for estimating AOO neutralize geometric uncertainty and incorporate effective scaling procedures for assessing risks posed by landscape‐scale threats to species and ecosystems. 相似文献
99.
Sophie Pierce Keith E. Schilling 《Journal of the American Water Resources Association》2023,59(5):913-928
Nutrient export from the agricultural Midwest threatens the Gulf of Mexico and new conservation practices are needed to reduce the loss of nutrient from subsurface tile drainage systems. Oxbows are natural waterbodies formed when a river cuts off a meander loop and water quality benefits of reconstructed oxbows are being increasingly recognized. In this study, we monitored four reconstructed oxbow sites (two tile-fed, two non-tile) over a 2-year period in north-central Iowa and assessed their capacity for NO3-N and dissolved reactive phosphorus (DRP) reductions. Water flow and quality monitoring of tiles, shallow groundwater, oxbow and receiving streams documented that the oxbows were dominated by tile drainage inputs. NO3-N concentrations were highest in the drainage tiles flowing into the tile-fed oxbows (mean 8–10 mg/L) and much lower in floodplain groundwater (<1–2 mg/L). Annual NO3-N loads into the tile-fed oxbows were substantially larger than input loads into the non-tiled oxbows. For the two tile-fed oxbows, the 2-year NO3-N retention efficiencies were very similar (0.76–0.77) and on a monthly basis, greater retention efficiencies were measured in summer and fall. DRP concentrations and loads into the tile-fed oxbows were too low to allow for meaningful estimates of retention. Reconstructing oxbows to receive tile drainage water should be considered a sustainable conservation practice for tile drainage treatment in agricultural areas. 相似文献
100.
Recent years have seen advancements in the development and use of life-cycle assessment (LCA) analytic techniques. Although these techniques have highlighted the power of LCA to identify the environmental consequences of a product system through its entire life cycle, they have also highlighted a major shortcoming of LCA—the lack of cost information. Because companies make daily decisions that involve trade-offs between economics and the environment, including cost information in LCA is critical for advancing its use as an overall environmental decision-making tool. This article outlines the current state of LCA methodology development, defines key life-cycle cost assessment terms and concepts, and evaluates existing cost assessment techniques with the objective of building an integrated life-cycle cost assessment tool. 相似文献