Environmental release of dioxins from reservoir sources during beach nourishment programs

In late 1990s, USEPA/FDA made an important connection regarding the presence of elevated levels of dioxins (e.g., 1500 ng kg⁻¹ TEQ) in ball clays mined in Mississippi (USA) from a geological deposit dated to ∼40 million years (Mississippi Embayment) that stretches over several states (northern part of Mississippi to Kentucky) and levels of dioxins in selected animal food sources. Following a recent beach nourishment program along the mid-Atlantic coast of the US, a number of dark gray, blue tinted nuggets of varying sizes were found on beach strands and near the shoreline. Using the presence of these balls of clay (shape, color, and knowledge regarding their use in pottery) on the beach, together with our direct experience analyzing ball clays for dioxins, we made a possible association between these clays and elevated dioxins. Concerns regarding the potential of nourishment programs to cause severe damage to our beaches drove us to test the dioxin content of nourishment exposed clays. A number of the nuggets, along with freshly dredged and deposited sand (collected the morning after nourishment) with the same coloration, and others (sun-bleached), collected approximately 2 weeks after the completion of the nourishment efforts, were analyzed for the presence of PCDD/Fs, PCBs, and selected semi-volatile chlorinated organics. The clay PCDD/F WHO2005-TEQs (dry weight; ND = DL; EMPC = EMPC) ranged from 0.41 to 5.78 ng kg⁻¹ with an average of 2.64 ng kg⁻¹, whereas the sand sample’s TEQs ranged from 0.18 to 0.31 ng kg⁻¹ PCDD/F WHO-2005, with an average of 0.22 ng kg⁻¹. The average total tetra- through octachlorinated dibenzo-p-dioxin concentration was 2700 ng kg⁻¹ (with a maximum of 5800 ng kg⁻¹) for the clays and 8.5 ng kg⁻¹ (with a maximum of 16.8 ng kg⁻¹) for the sand samples. The congener 2,3,7,8-TCDD (TEF = 1) was detected in half of the clay samples (0.11-0.77 ng kg⁻¹). All of the clay and sand samples displayed an unambiguous and dominating 1,4,6,9-chlorination pattern across homolog groups. No other chlorinated aromatics were detected above background levels. The observations, along with the absence or an extremely low level of polychlorinated dibenzofurans, together with the mineralogical analysis, supports the conclusion that off-shore dredging activities are reaching reservoir sources containing dioxin-tainted, smectic/kaolinite clay minerals. Subsequent beach erosion provides additional environmental releases over time, as buried balls of clay from previous nourishment efforts become exposed.     

浅谈西安市临潼区生态农业发展模式

本文通过对临潼区自然生态环境和资源利用现状进行评价,提出该区生态农业的发展模式及生态农业建设主要任务,以达到持续、高效、合理地利用区内各种资源。     

Refining the ecological footprint

Ecological footprint measures how much of the biosphere’s annual regenerative capacity is required to renew the natural resources used by a defined population in a given year. Ecological footprint analysis (EFA) compares the footprint with biocapacity. When a population’s footprint is greater than biocapacity it is reported to be engaging in ecological overshoot. Recent estimates show that humanity’s footprint exceeds Earth’s biocapacity by 23%. Despite increasing popularity of EFA, definitional, theoretical, and methodological issues hinder more widespread scientific acceptance and use in policy settings. Of particular concern is how EFA is defined and what it actually measures, exclusion of open oceans and less productive lands from biocapacity accounts, failure to allocate space for other species, use of agricultural productivity potential as the basis for equivalence factors (EQF), how the global carbon budget is allocated, and failure to capture unsustainable use of aquatic or terrestrial ecosystems. This article clarifies the definition of EFA and proposes several methodological and theoretical refinements. Our new approach includes the entire surface of the Earth in biocapacity, allocates space for other species, changes the basis of EQF to net primary productivity (NPP), reallocates the carbon budget, and reports carbon sequestration biocapacity. We apply the new approach to footprint accounts for 138 countries and compare our results with output from the standard model. We find humanity’s global footprint and ecological overshoot to be substantially greater, and suggest the new approach is an important step toward making EFA a more accurate and meaningful sustainability assessment tool.

The future of water in Australia: The potential effects of climate change and ozone depletion on Australian water quality,quantity and treatability

Water is a resource that is essential for all life on Earth. An exponentially growing human population, in addition to unprecedented industrial and technological development, threaten the availability and quality of this resource. Climate change and ozone depletion are two major environmental problems facing mankind today. These problems have the potential to further strain currently available freshwater resources. Recent research has shown that climate change and ozone depletion are linked phenomena and their interaction exacerbates their impact. Changes in precipitation, surface runoff, solar UV radiation, temperatures, and evaporation are some of the predicted outcomes of climate change and ozone depletion. They influence the biogeochemical cycles and aquatic ecosystems in lakes and rivers, and alter the character of natural organic matter (NOM) and, consequently, they have the potential to affect the quality, quantity and treatability of our water resources. Given these uncertainties, and the need to mitigate the consequences of climate change and ozone depletion, the issues of changing water quality, quantity and treatability cannot be ignored by Australian governments and water utilities.     

Participants and non-participants of place-based groups: an assessment of attitudes and implications for public participation in water resource management

Policy-makers and public participation analysts face the question of who should be involved in environmental decision-making. Participants are often representatives of organized groups who share similar demographic and other characteristics. This raises concerns about the degree to which the interests and opinions of others are represented. The research presented here investigates the nature and degree of differences in environmental attitudes, specifically those toward water resource management efforts, among people who do and do not participate in place-based groups in metropolitan Portland, Oregon. Neighborhood associations and a watershed council were the focus of this research due to their involvement in land-use planning and resource activities. Thirty-four individual attitudinal judgments were evaluated, along with four indices representing attitudes toward resource protection goals, government, regulations, and economic measures. Survey findings revealed watershed council participants were more supportive of resource protection compared to others on all attitudinal dimensions except anthropocentric goals. In contrast, neighborhood association participants are relatively representative of non-participants except for heightened support for economic strategies. Participants in both groups exhibited higher socioeconomic status than non-participants. Written survey comments highlighted the perceived value of on-the-ground projects incorporating local input and feedback while interviews provided insights on how to expand participation in place-based groups and resource protection efforts.     

Marine Parks for protection and tourism in Turkey

Protected Turkish areas in the Mediterranean region are compared with those of other Mediterranean countries. Policies followed in Turkey for conservation protection of the natural and cultural environment and the use of coastal resources for tourism are discussed. The purpose and application of Turkish law is examined with respect to the interaction between the protection of coastal areas and tourism. Modifications on the administrative and management regulations in Turkey enabling a better use of coastal areas is suggested by combining coastal tourism and protection. The necessity and importance of estabilishing and managing Marine Parks in short-and long-term plans are acknowledged.     

Source term estimation of natural gas leakage in utility tunnel by combining CFD and Bayesian inference method

As an effective way to construct and maintain various life pipelines in urban areas and industrial parks, the underground utility tunnel has been developed rapidly in China in recent years. However, the natural gas pipeline leakage in a utility tunnel may cause fire, explosion or other coupling disastrous accidents that could result in fatal consequences. The effective source term estimation (STE) of natural gas leakage can provide technical supports for emergency response during natural gas leakage accidents in utility tunnels. In this paper, a STE model with the combination of gas transport model, Bayesian inference and slice sampling method is proposed to estimate the source parameters of natural gas leakage in underground utility tunnels. The observed data can be integrated into the gas transport model and realize the inversion of natural gas leakage location and release rates. The parameter sensitivity analysis is presented to evaluate the robustness of the proposed model with good practicability, and the gas sensor layouts in the utility tunnel are analyzed and optimized. The spatio-temporal distribution of the leaked gas could be well predicted based on the estimation source parameters by the proposed STE model. The results show that the proposed model is an alternative and effective tool to provide technical supports for loss prevention and mitigation for natural gas leakage accidents in urban utility tunnels.     

Safety assessment of natural gas storage tank using similarity aggregation method based fuzzy fault tree analysis (SAM-FFTA) approach

Fault tree analysis (FTA) is an important method to analyze the failure causes of engineering systems and evaluate their safety and reliability. In practical application, the probabilities of bottom events in FTA are usually estimated according to the opinions of experts or engineers because it is difficult to obtain sufficient probability data of bottom events in fault tree. However, in many cases, there are many experts with different opinions or different forms of opinions. How to reasonably aggregate expert opinions is a challenge for the engineering application of fault tree method. In this study, a fuzzy fault tree analysis approach based on similarity aggregation method (SAM-FFTA) has been proposed. This method combines SAM with fuzzy set theory and can handled comprehensively diverse forms of opinions of different experts to obtain the probabilities of bottom events in fault tree. Finally, for verifying the applicability and flexibility of the proposed method, a natural gas spherical storage tank with a volume of 10,000 m³ was analyzed, and the importance of each bottom event was determined. The results show that flame, lightning spark, electrostatic spark, impact spark, mechanical breakdown and deformation/breakage have the most significant influence on the explosion of the natural gas spherical storage tank.     

探究林业生态保护与天然林保护的具体措施

在我国长期的发展与建设过程中,林业生态保护与天然林保护在很长的一段时期内被忽视,部分地区的环保设施与政策严重影响了当地甚至是全国的林业生态环境状况。     

The desirability of views of city skylines after dark

Three studies used digital color photographs to compare responses to natural scenes, skylines after dark, and skylines during the day (seven of each). Study 1 had 59 respondents rate the pleasantness of each scene. They gave similar ratings to Night Skylines and Natural Scenes, and rated each as more pleasant than the Day Skylines. Study 2 had 56 other participants choose from each of seven sets of each kind of scene the one they would most like to have as a framed print in their home or office, and to report the reasons. Participants chose Night Skylines most often, followed by Natural Scenes and then Day Skylines. While participants most often picked attractive as a reason for their choice, those who chose Night Skylines also picked exciting as the reason, and those who picked Natural Scenes also picked relaxing or peaceful as a reason. Study 3 obtained ratings of selected formal features of each scene. The 23 judges rated the Natural scenes as more natural, orderly, open, and curvilinear, less complex, and as having smoother transitions than either Day or Night Skylines; and they judged the Night Skylines as higher in complexity but lower in order than Day Skylines. The results suggest that preferences in relation to the scene categories may well depend on a mix of their formal characteristics and their content.