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791.
It is frequently argued that, at the parcel level, 1 stakeholders are capable of and well supported in managing their land‐related risks. Yet, evidence from the contemporary Australian context suggests otherwise: numerous large‐scale disaster events have revealed that citizens are ill‐prepared to respond and recover adequately. This paper begins with the premise that information, specifically land information, could better support parcel‐level risk preparation, mitigation, response, and recovery. State land administration organisations in Australia primarily maintain this information and make it accessible. Land information is used regularly across all levels of government to support risk management activities; however, such application has not always occurred at the parcel and citizen level. Via a case study approach, this paper initially explores the land information available in Australia to stakeholders interested in parcel‐level detail, and then goes on to propose how the utilisation of parcel‐level land information could serve to enhance risk management practices. 相似文献
792.
Aelion CM Davis HT Flora JR Kirtland BC Amidon MB 《Environmental pollution (Barking, Essex : 1987)》2009,157(1):186-193
Macrocapsules, composed of a pH-sensitive polymer and phosphate buffer, offer a novel remediation alternative for acidic ground waters. To test their potential effectiveness, laboratory experiments were carried out followed by a field trial within a coal pile runoff (CPR) acidic contaminant plume. Results of traditional limestone and macrocapsule treatments were compared in both laboratory and field experiments. Macrocapsules were more effective than limestone as a passive treatment for raising pH in well water from 2.5 to 6 in both laboratory and field experiments. The limestone treatments had limited impact on pH, only increasing pH as high as 3.3, and armoring by iron was evident in the field trial. Aluminum, iron and sulfate concentrations remained relatively constant throughout the experiments, but phosphate increased (0.15-32 mg/L), indicating macrocapsule release. This research confirmed that macrocapsules may be an effective alternative to limestone to treat highly acidic ground water. 相似文献
793.
Mark J. Benotti 《Environmental pollution (Barking, Essex : 1987)》2009,157(3):994-1002
Microbial degradation rates were measured for 19 pharmaceuticals in estuarine and coastal surface water samples. Antipyrine, carbamazepine, cotinine, sulfamethoxazole, and trimethoprim were the most refractory (half-lives, t1/2 = 35 to >100 days), making them excellent candidates for wastewater tracers. Nicotine, acetaminophen, and fluoxetine were labile across all treatments (t1/2 = 0.68-11 days). Caffeine, diltiazem, and nifedipine were also and relatively labile in all but one of the treatments (t1/2 = 3.5-13 days). Microbial degradation of caffeine was further confirmed by production 14CO2. The fastest decay of non-refractory compounds was always observed in more sewage-affected Jamaica Bay waters. Degradation rates for the majority of these pharmaceuticals are much slower than reported rates for small biomolecules, such as glucose and amino acids. Batch sorption experiments indicate that removal of these soluble pharmaceuticals from the water column to sediments is a relatively insignificant removal process in these receiving waters. 相似文献
794.
Loes M.J. Geelen Mark A.J. Huijbregts Henri den Hollander Ad M.J. Ragas Hans. A. van Jaarsveld Dick de Zwart 《Atmospheric environment (Oxford, England : 1994)》2009,43(9):1613-1621
This paper evaluates the ranking of 21 priority air pollutants with three indicator schemes: environmental pressure indicator (EPI), environmental quality indicator (EQI), and human health effect indicator (HEI). The EPI and EQI compare the emissions and concentrations with the target emissions and target concentrations, respectively. The HEI comprehends the steps from cause (i.e. national emissions) to effect (i.e. human health effects), and is the total human health burden, expressed in Disability Adjusted Life Years per year of exposure (DALYs year?1). We estimated a health burden in the Netherlands of 41 × 103 DALYs year?1 caused by Dutch air emissions of PM10 and its precursors in the year 2003. The burden due to 17 carcinogenic substances emitted to air, was much lower (140 DALYs year?1). In contrast, when the same substances were evaluated regarding environmental pressure and environmental quality, carbon tetrachloride (pressure) and benzo[a]pyrene (quality) were of highest importance, whereas the importance of PM10 was substantially lower. This result is remarkable, because for the majority of substances evaluated, the target concentrations and target emissions are based on preventing human health damage. The differences in relevance are explained by the different weighting of interests in the indicators. The HEI is based on concentration–response relations, whereas the EPI and EQI also depend on other, policy-based, principles and on technical feasibility. Therefore, to effectively prioritize emission reduction measures in policy-making, substances should not only be evaluated as to whether emission targets and environmental quality targets are reached, but they should be evaluated regarding their human health impact as well. In this context, the HEI is a suitable indicator to evaluate the human health impact. 相似文献
795.
This paper addresses the fluctuations in real metal prices: are they simply random variations or do they display some degree of cyclicality? This study identifies peaks and troughs in the inflation adjusted prices for 14 metals, using monthly average data from January 1947 through December 2007. Duration dependence testing, which is performed on the expansions, contractions, and full cycles, finds many cases in which the duration of these phases are not purely random and have some degree of cyclicality. Additional characterization show that contractions generally persist longer than expansions (in contrast to macroeconomic cycles) that long-term real prices have been trendless, and that the amplitude of price changes over the phases has little regularity. For those performing this type of analysis, the appendices explain the procedures for dating turning points and assessing duration dependence. 相似文献
796.
Modeling watershed-scale effectiveness of agricultural best management practices to reduce phosphorus loading 总被引:1,自引:0,他引:1
Nalini S. Rao Zachary M. Easton Elliot M. Schneiderman Mark S. Zion David R. Lee Tammo S. Steenhuis 《Journal of environmental management》2009
Planners advocate best management practices (BMPs) to reduce loss of sediment and nutrients in agricultural areas. However, the scientific community lacks tools that use readily available data to investigate the relationships between BMPs and their spatial locations and water quality. In rural, humid regions where runoff is associated with saturation-excess processes from variable source areas (VSAs), BMPs are potentially most effective when they are located in areas that produce the majority of the runoff. Thus, two critical elements necessary to predict the water quality impact of BMPs include correct identification of VSAs and accurate predictions of nutrient reduction due to particular BMPs. The objective of this research was to determine the effectiveness of BMPs using the Variable Source Loading Function (VSLF) model, which captures the spatial and temporal evolutions of VSAs in the landscape. Data from a long-term monitoring campaign on a 164-ha farm in the New York City source watersheds in the Catskills Mountains of New York state were used to evaluate the effectiveness of a range of BMPs. The data spanned an 11-year period over which a suite of BMPs, including a nutrient management plan, riparian buffers, filter strips and fencing, was installed to reduce phosphorus (P) loading. Despite its simplicity, VSLF predicted the spatial distribution of runoff producing areas well. Dissolved P reductions were simulated well by using calibrated reduction factors for various BMPs in the VSLF model. Total P losses decreased only after cattle crossings were installed in the creek. The results demonstrated that BMPs, when sited with respect to VSAs, reduce P loss from agricultural watersheds, providing useful information for targeted water quality management. 相似文献
797.
Cross-Boundary Coordination on Forested Landscapes: Investigating Alternatives for Implementation 总被引:2,自引:0,他引:2
Cross-boundary coordination is a tool for ecosystem management whereby landowners voluntarily coordinate management practices
toward economic and/or ecological landscape-scale outcomes (e.g., fiber, invasive species control, habitat). Past research
indicates that it may be particularly applicable on landscapes that include small forest landholdings. To explore alternatives
by which coordination might occur, we conducted seven focus groups with landowners (n = 51) who actively manage their forests in southwest Wisconsin and northeast Iowa. Focus group participants were presented
with three hypothetical alternatives to coordinate with their neighbors; landowners could self-organize, work with a natural
resource professional (i.e., forester), or work with an organization to complete a cross-boundary practice. In this article,
we focus on the latter two alternatives and the role of two social theories—principal-agent and cooperation—in explaining
landowners’ evaluations of these alternatives. Key findings are that (1) cross-boundary coordination has the potential to
alleviate problems between landowners and resource professionals inherent to their typical working relationship, and (2) social
relationships are a major factor contributing to landowners’ willingness to participate. We posit that cross-boundary coordination
offers a non-economic incentive for landowners to work together as it may reduce the uncertainty associated with hiring a
resource professional. At the same time, professionals can provide a bridging function among landowners who are unacquainted.
To achieve these outcomes and expand the adoption of cross-boundary coordination, we suggest four guidelines. First, foster
dialogue among landowners toward shared cognition and oversight. Second, match landowners’ practices and objectives such that
there are clear benefits to all. Third, develop relationships through low risk activities where possible. Fourth, do not expect
on-going commitments.
相似文献
Mark RickenbachEmail: |
798.
Making Consistent IUCN Classifications under Uncertainty 总被引:5,自引:0,他引:5
H. Reit Akçakaya†† Scott Ferson Mark A. Burgman† David A. Keith‡ Georgina M. Mace§ Charles R. Todd 《Conservation biology》2000,14(4):1001-1013
Abstract: The World Conservation Union (IUCN) defined a set of categories for conservation status supported by decision rules based on thresholds of parameters such as distributional range, population size, population history, and risk of extinction. These rules have received international acceptance and have become one of the most important decision tools in conservation biology because of their wide applicability, objectivity, and simplicity of use. The input data for these rules are often estimated with considerable uncertainty due to measurement error, natural variation, and vagueness in definitions of parameters used in the rules. Currently, no specific guidelines exist for dealing with uncertainty. Interpretation of uncertain data by different assessors may lead to inconsistent classifications because attitudes toward uncertainty and risk may have an important influence on the classification of threatened species. We propose a method of dealing with uncertainty that can be applied to the current IUCN criteria without altering the rules, thresholds, or intent of these criteria. Our method propagates the uncertainty in the input parameters and assigns the evaluated species either to a single category (as the current criteria do) or to a range of plausible categories, depending on the nature and extent of uncertainties. 相似文献
799.
Summary. A recent investigation showed that the brown seaweed Dictyota menstrualis was unfouled relative to co-occurring seaweeds, and that larvae of fouling invertebrates avoided settling on D. menstrualis due to chemicals on its surface. The secondary metabolites dictyol E and pachydictyol A are among the compounds found on
this alga's surface. In the present study, we tested the effects of specific diterpenes from Dictyota on the survivorship, growth, and development of invertebrate larvae and developing juveniles that could foul seaweeds. Exposure
to dictyol E, dictyol B acetate, pachydictyol A, and dictyodial from Dictyota menstrualis and D. ciliolata caused significant larval mortality, abnormal development, and reduce growth rates for three species of co-occurring invertebrates
when their larvae were forced into contact with these metabolites. Larvae were damaged at metabolite concentrations as low
as 5% of maximum possible surface concentrations of these compounds for the populations of Dictyota we studied. The negative effects of these secondary metabolites on potential foulers, in conjunction with data demonstrating
larval avoidance of dictyol-covered surfaces, suggest that these compounds could function as chemical defenses against fouling,
and could select for larvae that avoid hosts producing these metabolites.
Received 25 May 1998; accepted 22 June 1998. 相似文献
800.
/ Investigation of a delta marsh restoration project proposed forthe Don River in Toronto, Ontario, underlines several concerns aboutconstructed wetland projects designed for water quality improvement andaquatic habitat enhancement. The Don is a highly urbanized river that hasundergone significant physiographic modifications and continually receives acomplex mixture of conventional, metallic, and organic contaminants frommultiple point and nonpoint sources. Rather than providing permanent removalof urban contaminants, wetland processes offer a limited capacity fortemporary storage of contaminant inputs, and potential reactions may actuallyproduce more toxic and/or bioavailable forms of some chemicals. Theseprocesses tend to result in the concentration of watershed contaminants inwetland vegetation and sediments. As the restored marsh would be availablefor spawning and feeding by aquatic fauna, the potential exists for chemicalbioconcentration and biomagnification through the aquatic community.Accordingly, wetland systems are not suited to the dual purposes of waterquality improvement and aquatic habitat enhancement. Upstream controls,including source reduction of contaminant inputs, are recommended asessential components of all constructed wetland projects.KEY WORDS: Constructed wetlands; Water quality; Ecological restoration;Don River 相似文献