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1.
Phosphorus (P) is a finite and non-substitutable resource that is essential to sustaining high levels of agricultural productivity but is also responsible for environmental problems, e.g., eutrophication. Based on the methodology of Material Flow Analysis, this study attempts to quantify all relevant flows and stocks of phosphorus (P) in Austria, with a special focus on waste and wastewater management. The system is modeled with the software STAN, which considers data uncertainty and applies data reconciliation and error propagation. The main novelty of this work lies in the high level of detail at which flows and stocks have been quantified to achieve a deeper understanding of the system and to provide a sound basis for the evaluation of various management options. The budget confirms on the one hand the dependence of mineral P fertilizer application (2 kg cap−1 yr−1), but it highlights on the other hand considerable unexploited potential for improvement. For example, municipal sewage sludge (0.75 kg cap−1 yr−1) and meat and bone meal (0.65 kg cap−1 yr−1) could potentially substitute 70% of the total applied mineral P fertilizers. However, recycling rates are low for several P flows (e.g., 27% of municipal sewage sludge; 3% of meat and bone meal). Therefore, Austria is building up a remarkable P stock (2.1 kg P cap−1 yr−1), mainly due to accumulation in landfills (1.1 kg P cap−1 yr−1) and agricultural soils (0.48 kg P cap−1 yr−1).  相似文献   

2.
Empirical critical loads for N deposition effects and maps showing areas projected to be in exceedance of the critical load (CL) are given for seven major vegetation types in California. Thirty-five percent of the land area for these vegetation types (99,639 km2) is estimated to be in excess of the N CL. Low CL values (3–8 kg N ha?1 yr?1) were determined for mixed conifer forests, chaparral and oak woodlands due to highly N-sensitive biota (lichens) and N-poor or low biomass vegetation in the case of coastal sage scrub (CSS), annual grassland, and desert scrub vegetation. At these N deposition critical loads the latter three ecosystem types are at risk of major vegetation type change because N enrichment favors invasion by exotic annual grasses. Fifty-four and forty-four percent of the area for CSS and grasslands are in exceedance of the CL for invasive grasses, while 53 and 41% of the chaparral and oak woodland areas are in exceedance of the CL for impacts on epiphytic lichen communities. Approximately 30% of the desert (based on invasive grasses and increased fire risk) and mixed conifer forest (based on lichen community changes) areas are in exceedance of the CL. These ecosystems are generally located further from emissions sources than many grasslands or CSS areas. By comparison, only 3–15% of the forested and chaparral land areas are estimated to be in exceedance of the NO3? leaching CL. The CL for incipient N saturation in mixed conifer forest catchments was 17 kg N ha?1 yr?1. In 10% of the CL exceedance areas for all seven vegetation types combined, the CL is exceeded by at least 10 kg N ha?1 yr?1, and in 27% of the exceedance areas the CL is exceeded by at least 5 kg N ha?1 yr?1. Management strategies for mitigating the effects of excess N are based on reducing N emissions and reducing site N capital through approaches such as biomass removal and prescribed fire or control of invasive grasses by mowing, selective herbicides, weeding or domestic animal grazing. Ultimately, decreases in N deposition are needed for long-term ecosystem protection and sustainability, and this is the only strategy that will protect epiphytic lichen communities.  相似文献   

3.
There is increasing awareness of the damage caused to valuable and often unique sensitive habitats by people pressure as degradation causes a loss of plant species, disturbance to wildlife, on-site and off-site impacts of soil movement and loss, and visual destruction of pristine environments. This research developed a new perspective on the problem of recreational induced environmental degradation by assessing the physical aspects of soil erosion using the fallout radionuclide caesium-137 (137Cs). Temporal sampling problems have not successfully been overcome by traditional research methods monitoring footpath erosion and, to date, the 137Cs technique has not been used to estimate longer-term soil erosion in regard to sensitive recreational habitats. The research was based on-sites within Dartmoor National Park (DNP) and the South West Coast Path (SWCP) in south-west England. 137Cs inventories were reduced on the paths relative to the reference inventory (control), indicating loss of soil from the path areas. The Profile Distribution Model estimated longer-term erosion rates (ca. 40 years) based on the 137Cs data and showed that the combined mean soil loss for all the sites on ‘paths’ was 1.41 kg m?2 yr?1 whereas the combined ‘off path’ soil loss was 0.79 kg m?2 yr?1, where natural (non-recreational) soil redistribution processes occur. Recreational pressure was shown to increase erosion in the long-term, as greater soil erosion occurred on the paths, especially where there was higher visitor pressure.  相似文献   

4.
This study examines the effects of acidifying sulphur emissions on freshwater ecosystems in the traditional territory of Treaty 8 First Nations in British Columbia (BC). Due to the absence of detailed water chemistry data for most lakes in the region, revised empirical methods for estimating freshwater sensitivity to acidification are formulated using linear regression relationships between individual chemical measurements, and critical loads of acidity calculated using the Steady State Water Chemistry (SSWC) model. Lake alkalinity is the most effective chemical indicator of acidification sensitivity in northeast BC. Critical loads of acidity (CL(A)) estimated using alkalinity range from 0.0827 to 9.48 keq ha?1 yr?1. Sulphur deposition estimates range from 0.0113 to 0.303 keq ha?1 yr?1 and do not exceed the estimated CL(A) at any of the study lakes. The spatial situation of both the lakes and the emission sources is responsible for the lack of exceedances, and expanded/continued monitoring is recommended to account for geological variability and source proliferation. Measurements of lake conductivity and alkalinity provide a means of community monitoring for freshwater acidification sensitivity as part of cumulative effects management strategies.  相似文献   

5.
Emergy Evaluation of the Natural Value of Water Resources in Chinese Rivers   总被引:1,自引:0,他引:1  
Emergy theory and method were used to evaluate the economy of China and the contributions of water resources in Chinese rivers to the real wealth of the Chinese economy. The water cycle and energy conversion were reviewed, and an emergy method for evaluating the natural value of water resources in a river watershed was developed. The indices for China calculated from the emergy evaluation were close to those of developing countries. Despite a small surplus in its balance of payments, China had a net emergy loss from its trade in 2002. The efficiency of Chinese natural resource use was still not high and did not match its economic growth rate. Furthermore, the Chinese economy placed a stress on its ecological environment and natural resources. Several indices of Chinese rivers from the emergy evaluation were close to those of average global river water. The main average indices of Chinese rivers were transformity (4.17 × 104 sej/J), emergy per volume (2.05 × 1011 sej/m3), and emdollar per volume (0.06 $/m3). The total value of all the rivers’ water made up 13.0% of the GDP of China in 2002, and that of water consumption accounted for 2.1%. The value of the water resources in the Haihe-luanhe River (11.39 × 104 sej/J) was the highest, followed by the Yellow River (10.27 × 104 sej/J), while the rivers in Southwest China had the lowest values (2.92 × 104 sej/J).  相似文献   

6.
ABSTRACT: Recent studies suggest that waste generation from the freshwater phase of Atlantic salmon (Salmo salar L.) production varies considerably on an annual basis. A fish farm on the West Coast of Scotland was visited regularly during a two-year period to determine inflow and outflow water quality. Waste output budgets of suspended solids (SS), biochemical oxygen demand (BOD), total nitrogen (TN), total phosphorus (TP), total ammonia nitrogen (TAN = NH3+NH4+), dissolved reactive phosphorus (DRP) and total phosphorus (TP) were produced. The annual waste loadings obtained were 71 kg TN t fish?1 yr?1 (one year of data only), 10.9–11.1 kg TP t fish?1 yr?1, 1.2–2.1 kg DRP t fish?1 yr?1, 422–485 kg BOD5 t fish?1 yr?1, 327–337 kg SS t fish?1 yr?1, and 30–35 kg TAN-N t fish?1 yr?1. Simple linear regression models relating waste parameter production to water temperature and feeding regime were developed. When compared to existing data for other salmonid production systems, greater ranges of daily waste loadings were observed. Wide variations in concentrations of these parameters during a daily cycle were also observed, suggesting that mass balance estimates of waste production will provide more robust estimates of waste output than frequent monitoring of outflow water quality.  相似文献   

7.
ABSTRACT: Nitrogen and P fluxes, transformations and water quality functions of Lake Verret (a coastal Louisiana freshwater lake), were quantified. Ortho-P, total-P, NH4+-N NO3 -N and TKN in surface water collected from streams feeding Lake Verret averaged 104, 340, 59, 185, and 1,060 mg 1?1, respectively. Lake Verret surface water concentrations of ortho-P, total-P, NH+-N, NO3?-N and TKN averaged 66, 191, 36, 66, and 1,292 μg 1?1. The higher N and P concentrations were located in areas of the lake receiving drainage. Nitrification and denitrification processes were significant in removing appreciable inorganic N from the system. In situ denitrification rates determined from acetylene inhibition techniques show the lake removes 560 mg N m?2 yr?1. Laboratory investigations using sediment receiving 450 μg NH+4-N (N-15 labeled) showed that the lake has the potential to remove up to 12.8 g N m?2 yr?1. Equilibrium studies of P exchanges between the sediment and water column established the potential or adsorption capacity of bottom sediment in removing P from the overlying water. Lake Verret sediment was found to adsorb P from the water column at concentrations above 50 μg P 1?1 and the adsorption rates were as great as 300 μg P cm?2 day?1 Using the 137C s dating techniques, approximately 18 g N m?2 yr?1 and 1.2 g P m?2 yr?1 were removed from the system via sedimentation. Presently elevated nutrient levels are found only in the upper reaches of the lake receiving nutrient input from runoff from streams draining adjacent agricultural areas. Nitrification, denitrification, and adsorption processes at the sediment water interface over a relatively short distance reduces the N and P levels in the water column. However, if the lake receives additional nutrient loading, elevated levels will likely cover a larger portion of the lake, further reducing water quality in the lake.  相似文献   

8.
Sustainable water use is seriously compromised in the North China Plain (NCP) due to the huge water requirements of agriculture, the largest use of water resources. An integrated approach which combines the ecosystem model with emergy analysis is presented to determine the optimum quantity of irrigation for sustainable development in irrigated cropping systems. Since the traditional emergy method pays little attention to the dynamic interaction among components of the ecological system and dynamic emergy accounting is in its infancy, it is hard to evaluate the cropping system in hypothetical situations or in response to specific changes. In order to solve this problem, an ecosystem model (Vegetation Interface Processes (VIP) model) is introduced for emergy analysis to describe the production processes. Some raw data, collected by investigating or observing in conventional emergy analysis, may be calculated by the VIP model in the new approach. To demonstrate the advantage of this new approach, we use it to assess the wheat-maize rotation cropping system at different irrigation levels and derive the optimum quantity of irrigation according to the index of ecosystem sustainable development in NCP. The results show, the optimum quantity of irrigation in this region should be 240–330 mm per year in the wheat system and no irrigation in the maize system, because with this quantity of irrigation the rotation crop system reveals: best efficiency in energy transformation (transformity = 6.05E + 4 sej/J); highest sustainability (renewability = 25%); lowest environmental impact (environmental loading ratio = 3.5) and the greatest sustainability index (Emergy Sustainability Index = 0.47) compared with the system in other irrigation amounts. This study demonstrates that application of the new approach is broader than the conventional emergy analysis and the new approach is helpful in optimizing resources allocation, resource-savings and maintaining agricultural sustainability.  相似文献   

9.
Mathematical tools are needed to screen out sites where Joule–Thomson cooling is a prohibitive factor for CO2 geo-sequestration and to design approaches to mitigate the effect. In this paper, a simple analytical solution is developed by invoking steady-state flow and constant thermophysical properties. The analytical solution allows fast evaluation of spatiotemporal temperature fields, resulting from constant-rate CO2 injection. The applicability of the analytical solution is demonstrated by comparison with non-isothermal simulation results from the reservoir simulator TOUGH2. Analysis confirms that for an injection rate of 3 kg s?1 (0.1 MT yr?1) into moderately warm (>40 °C) and permeable formations (>10?14 m2 (10 mD)), JTC is unlikely to be a problem for initial reservoir pressures as low as 2 MPa (290 psi).  相似文献   

10.
In the Mediterranean region the intensities and amounts of soil loss and runoff on sloping land are governed by rainfall pattern and vegetation cover. Over a two-year period (1998–1999), six wild species of aromatic and mellipherous plants (Thymus serpylloides subsp. Gadorensis, Thymus baeticus Boiss, Salvia lavandulifolia Vahl., Santolina rosmarinifolia L., Lavandula stoechas L. and Genista umbellata Poiret) were selected for erosion plots to determine their effectiveness in reducing water erosion on hillslopes of the Sierra Nevada Mountain (SE Spain). The erosion plots (including a bare-soil plot as control), located at 1,345 m in altitude, were 2 m2 (2 m × 1 m) in area and had 13% incline. The lowest runoff and soil erosion rates, ranging from 9 to 26 mm yr−1 and from 0.01 to 0.31 Mg ha−1 yr−1, respectively, over the entire study period, were measured under the Thymus serpylloides. Lavandula stoechas L. registered the highest rates among the plant covers tested, runoff ranging from 77 to 127 mm yr−1 and erosion from 1.67 to 3.50 Mg ha−1 yr−1. In the bare-soil plot, runoff ranged from 154 to 210 mm yr−1 and erosion from 4.45 to 7.82 Mg ha−1 yr−1. According to the results, the lowest-growing plant covers (Thymus serpylloides and Salvia lavandulifolia Vahl.) discouraged the soil erosion and runoff more effectively than did the taller and open medium-sized shrubs (Santolina rosmarinifolia L., Genista umbellata Poiret, Thymus baeticus Boiss and Lavandula stoechas L.). Monitoring allowed more direct linkage to be made between plant covers and the prevention of erosion, with implications for sustainable mountain agriculture and environmental protection.  相似文献   

11.
The aim of this paper is to evaluate two agroindustrial productive processes in their entirety (one organic and one semi-industrial), focusing on the comparison of impacts derived from the inputs and outputs of the system (life cycle assessment, LCA), integrated with a physical evaluation of the resources and natural services, on a common basis (emergy). Methods based on the joint use of LCA and emergy evaluation are useful, as they measure the contribution of environmental services and products to the productive process thus focusing primarily on the environmental impact of emissions and non-renewable energy inputs. The complementarity of the methods used in this paper contributes important elements and information useful for the comprehension of the organization of agriculture within Siena's territory. The results show important elements and useful information: (1) for the comprehension of the two agroecosystems' organization; (2) for the use of the energy flows that determine their development. Moreover, the combined use of emergy and LCA gives a comparative thermodynamic performance evaluation between organic and semi-industrial farming.  相似文献   

12.
This article discusses the potential of Geographic Information Systems (GIS) to become an information technology enabling groups of people to participate in decisions shaping their communities and promoting sustainable use of natural resources. It explains the concept of participation in the context of planning and decision making. In this context Participatory GIS (PGIS) offers tools that can be used to help the public become meaningfully involved in decision making processes affecting their communities. Following an overview of research on PGIS and its current status the article presents two recent studies of PGIS in water resource planning; one involving the use of computer generated maps representing simple information structures and the other involving the use of more sophisticated information tools. The synthesis of both studies provides the bases for discussing the prospects of PGIS to empower citizens in making decisions about their communities and resources.  相似文献   

13.
Environmental justice addresses inequitable distributions of health risks from exposure to pollution and other hazards. Appalachian residents of southeastern Ohio who live along the Ohio River are disproportionately subject to industrial pollution. Of particular concern is the DuPont Washington Works plant where perfluorooctanoic acid, or C8, was used to make consumer products. Although company officials became aware in 1984 that the water supply of Little Hocking, Ohio, was tainted with C8 coming from its plant, residents were not notified until 2002. Subsequent studies determined a number of health problems, including cancer, are linked to residents’ exposure. This qualitative study asked Little Hocking residents and environmental regulators if they consider C8 contamination in Little Hocking an injustice. Results indicate a lack of consensus – even among affected residents – concerning DuPont's® actions as constituting an injustice. This finding, among others, is used to argue that many residents in Little Hocking, through their association with DuPont®, benefit from class-based forms of privilege and seek to maintain them in the context of immobility and economic uncertainty. This explains why some communities may be considered an environmental justice community from an academic standpoint, but not self-identify as such. However, maintaining privilege at the local scale in the context of weak regulation enhances exploitation in Little Hocking while contributing to power at extra-local scales. Thus, environmental justice activists in white, working-class communities must overcome the challenge posed by privilege that defends the contaminated status quo.  相似文献   

14.
Based on the method of material flow analysis (MFA), a static model of Austrian aluminum (Al) flows in 2010 was developed. Extensive data research on Al production, consumption, trade and waste management was conducted and resulted in a detailed model of national Al resources. Data uncertainty was considered in the model based on the application of a rigorous concept for data quality assessment. The model results indicated that the growth of the Austrian “in-use” Al stock amounts to 11 ± 3.1 kg yr−1 cap−1. The total “in-use” Al stock was determined using a bottom-up approach, which produced an estimate of 260 kg Al cap−1. Approximately 7 ± 1 kg of Al yr−1 cap−1 of old scrap was generated in 2010, of which 20% was not recovered because of losses in waste management processes. Quantitatively, approximately 40% of the total scrap input to secondary Al production originated from net imports, highlighting the import dependency of Austrian Al refiners and remelters. Uncertainties in the calculation of recycling indicators for the Austrian Al system with high shares of foreign scrap trade were exemplarily illustrated for the old scrap ratio (OSR) in secondary Al production, resulting in a possible range of OSRs between 0 and 66%. Overall, the detailed MFA in this study provides a basis to identify resource potentials as well as resource losses in the national Al system, and it will serve as a starting point for a dynamic Al model to be developed in the future.  相似文献   

15.
ABSTRACT: Environmental background levels of Pb were measured in ponds, river waters, sediments, suspended sediments, rocks, and air particulates within the Kankakee watershed during the period of 1995 to 1999. Stable isotopic Pb distinguished airborne Pb and its incorporation into riverine wetland sediments from geogenic Pb measured in river sediments. The provenance of the naturally‐occurring Pb is from carbonate bedrock and contributes comparable concentrations in riverbank sediments (25.9–30.4 mg kg?1) as Pb found in wetland sediments (18.6–24.8 mg kg?1). Estimates of anthropogenic Pb contributions from airfall into the Kankakee wetlands were found to be near 0.43–0.71 Bq cm?2 yr?1 during 1995 to 1999. While leachable Pb data suggests the uppermost layers of pond sediments were disturbed, 210Pb analyses from undisturbed sedimentation suggests Pb‐bearing sediments accumulate approximately 0.46–0.51 cm yr?1 in the ponds within the riparian zones. Transboundary Pb pollution from aerosols of industrial Pb across the Great Lakes occurs, but Pb isotopy indicates that the Pb concentrations are comparable to natural concentrations of Pb in both waters and sediments within the Kankakee watershed.  相似文献   

16.
ABSTRACT: The quantity, seasonality, and sources of flow were analyzed for two segments of Four Mile Branch, a small stream on the Coastal Plain of South Carolina using data obtained from USGS gauging stations. Flows in the “upstream segment,” a 12.6-km2 watershed comprising the head waters of Four Mile Branch, averaged 0.129 m3 s?1 and showed a distinctly seasonal pattern, with maximum flows in February and March and minimum flows in September and October. Inflow to the “downstream segment,” a 2.2-km2 watershed associated with the main channel, averaged 0.059 m3 s?1 and showed no seasonal patterns. Discharges per unit area of watershed were greater for the downstream segment, 0.83 m3 per year per m2 of land surface, than for the upstream segment, 0.32 m3 per year per m2. The differences in discharge rates and seasonalities between the two segments reflect differences in aquifers supplying the different segments. Analyses of Streamflow by hydrograph separation and Streamflow partitioning methods indicated that greater than 90 percent of the flows in the upstream and downstream segments were due to ground water-driven base flows.  相似文献   

17.
Abstract

Participatory GIS (geographic information systems) is designed to use community mapping exercises to produce spatial representations of local knowledge. The ideals of Participatory GIS revolve around the concept of public participation in the use of spatial data leading to increased community involvement in policy-setting and decision-making (Weiner et al., Community participation and geographic information systems, in: Craig et al., Community participation and geographic information systems, London: Taylor & Francis, 2002). This paper reports on findings from two case studies, one relating to assessments of air quality and how Participatory GIS has been used in the UK to improve local government policy, and the second on assessments of noise pollution. It concludes by discussing a caveat on the use of Participatory GIS for environmental governance, which is that, ideally, only issues on which participants are likely to have direct experiential knowledge should be targeted.  相似文献   

18.
Wastewater treatment practices should pay more attention to their environmental performances due to their resources consumption and emissions’ impact. While reclaimed water reuse seems to have become a promising practice, is it always feasible in any condition? To address this issue, this study carried out an extended emergy evaluation of a holistic wastewater treatment system. On one hand, this method was extended to include the emissions’ impact. On the other hand, this study integrated a wastewater treatment plant, its excess sludge disposal system and treated water disposal system into an integrated wastewater treatment system (IWTS), so as to evaluate its performances more completely. And then several indicators, including cost per unit pollutant eliminated (CUPE), ratio of positive output (RPO), environmental load ratio (ELR), and sustainability index (SI), were proposed for evaluating the performances of an IWTS. Two scenarios (scenario A: wastewater treatment + sludge landfilling + treated water discharges; scenario B: wastewater treatment + sludge landfilling + reclaimed water reuse) for a livestock wastewater treatment plant in Sichuan Agricultural University located in Ya’an City in Southwest China, as cases, were researched. The results show that scenario B has lower positive output efficiency and greater environmental load than scenario A. Meanwhile, the reclaimed water reuse raises cost per unit pollutant eliminated compared with the treated water being discharged directly; emissions’ impact enhances the environmental load of the two scenarios to different degree; emissions’ impact has decisive effect on the sustainability of the two scenarios. These results mean that the reclaimed water reuse should not be advocated in this case. This study provides some policy implications: (1) wastewater treatment process should be comprehensively evaluated from its resources consumption and impact of emissions; (2) reclaimed water reuse should be carefully evaluated from its pros and cons simultaneously; (3) the local conditions should be considered when implementing reclaimed water reuse, such as local water body conditions, market demands, the related laws and regulations, corporations’ economic conditions, etc.  相似文献   

19.
基于能值理论,结合生态足迹方法,构建能值生态赤字/盈余、渔业足迹强度(D)、社会发展压力指数(I)和经济协调指数(Q)参数评价海岛可持续性,选取典型海岛城市浙江省舟山市作为案例研究。结果显示:2003—2017年舟山能值足迹、能值承载力均呈上升趋势;人均能值生态足迹共增加15.78 hm2,增幅为63.26%;人均能值承载力增加5.20×102 hm2,增幅为82.86%;其中,化石能源用地能值足迹增加最多,社会经济承载力增加最多,而自然承载力却有所下降。能值生态赤字/盈余和经济协调指数不能完全反映区域可持续性,区域渔业足迹强度的不断增加表明当前的渔业经济模式不满足可持续发展要求,社会发展压力指数增大也进一步表明舟山的发展状况偏离了可持续性的轨道。  相似文献   

20.
ABSTRACT

The exploration and potential extraction of shale gas – better known as fracking – has emerged as one of the most contentious dimensions to local environmental politics in the UK. Local residents and environmental activists have raised concerns about health, noise, ground water contamination, seismicity, environmental amenity, and other impacts of the industry on communities. Despite the complexities of shale gas extraction, an emphasis on the local has shaped key dimensions of the debate around the appropriate location for well pads to the relative exclusion of other issues. This paper draws on fieldwork in Lancashire, UK, to reflect on the political construction of scale in order to explore how an emphasis on “the local” can restrict political debate over shale gas to narrow concerns with land-use planning thereby obviating a fuller engagement with wider questions concerning risk, energy policy, and climate change. It is concluded that a more nuanced conception of scale is necessary for understanding how concerns with shale gas are diminished rather than strengthened through the current planning policy and regulatory regime operating in the UK.  相似文献   

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