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991.
Assessment of the Water Quality and Ecosystem Health of the Great Barrier Reef (Australia): Conceptual Models 总被引:3,自引:0,他引:3
Haynes D Brodie J Waterhouse J Bainbridge Z Bass D Hart B 《Environmental management》2007,40(6):993-1003
Run-off containing increased concentrations of sediment, nutrients, and pesticides from land-based anthropogenic activities
is a significant influence on water quality and the ecologic conditions of nearshore areas of the Great Barrier Reef World
Heritage Area, Australia. The potential and actual impacts of increased pollutant concentrations range from bioaccumulation
of contaminants and decreased photosynthetic capacity to major shifts in community structure and health of mangrove, coral
reef, and seagrass ecosystems. A detailed conceptual model underpins and illustrates the links between the main anthropogenic
pressures or threats (dry-land cattle grazing and intensive sugar cane cropping) and the production of key contaminants or
stressors of Great Barrier Reef water quality. The conceptual model also includes longer-term threats to Great Barrier Reef
water quality and ecosystem health, such as global climate change, that will potentially confound direct model interrelationships.
The model recognises that system-specific attributes, such as monsoonal wind direction, rainfall intensity, and flood plume
residence times, will act as system filters to modify the effects of any water-quality system stressor. The model also summarises
key ecosystem responses in ecosystem health that can be monitored through indicators at catchment, riverine, and marine scales.
Selected indicators include riverine and marine water quality, inshore coral reef and seagrass status, and biota pollutant
burdens. These indicators have been adopted as components of a long-term monitoring program to enable assessment of the effectiveness
of change in catchment-management practices in improving Great Barrier Reef (and adjacent catchment) water quality under the
Queensland and Australian Governments’ Reef Water Quality Protection Plan. 相似文献
992.
Lavee D 《Environmental management》2007,40(6):926-943
It has traditionally been argued that recycling municipal solid waste (MSW) is usually not economically viable and that only
when externalities, long-term dynamic considerations, and/or the entire product life cycle are taken into account, recycling
becomes worthwhile from a social point of view. This article explores the results of a wide study conducted in Israel in the
years 2000–2004. Our results reveal that recycling is optimal more often than usually claimed, even when externality considerations
are ignored.
The study is unique in the tools it uses to explore the efficiency of recycling: a computer-based simulation applied to an
extensive database. We developed a simulation for assessing the costs of handling and treating MSW under different waste-management
systems and used this simulation to explore possible cost reductions obtained by designating some of the waste (otherwise
sent to landfill) to recycling. We ran the simulation on data from 79 municipalities in Israel that produce over 60% of MSW
in Israel. For each municipality, we were able to arrive at an optimal method of waste management and compare the costs associated
with 100% landfilling to the costs born by the municipality when some of the waste is recycled. Our results indicate that
for 51% of the municipalities, it would be efficient to adopt recycling, even without accounting for externality costs. We
found that by adopting recycling, municipalities would be able to reduce direct costs by an average of 11%.
Through interviews conducted with representatives of municipalities, we were also able to identify obstacles to the utilization
of recycling, answering in part the question of why actual recycling levels in Israel are lower than our model predicts they
should be. 相似文献
993.
Although the importance of understanding stakeholder beliefs regarding environmental policy has been noted by many authors,
research focusing on the heterogeneity of stakeholder views is still very scarce and concentrated on a product-oriented definition
of stakeholders. The aim of the present study is to address this gap by examining environmental policy beliefs of stakeholder
groups engaged in protected area management. Questionnaires containing 73 five-point Likert scale items were administered
to eight different stakeholder groups involved in the management of Greek protected areas. Items referred to core beliefs
on environmental policy, namely, the value framework and sustainable development, and secondary beliefs, that is, beliefs
on social consensus and ecotourism development. Our study used as a starting point respondent recruitment on the basis of
a traditional product-centered approach. We investigated whether environmental policy beliefs can be used to effectively segregate
stakeholders in well-defined segments, which override the product-oriented definition of stakeholders. Indeed, K-means clustering
revealed an innovation-introduction and an implementation-charged sample segment. The instrument utilized in this research
proved quite reliable and valid in measuring stakeholder environmental policy beliefs. Furthermore, the methodology implied
that stakeholder groups differ in a significant number of belief-system elements. On the other hand, stakeholder groups were
effectively distinguished on a small set of both core and secondary beliefs. Therefore, the instrument used can be an effective
tool for determining and monitoring environmental policy beliefs of stakeholders in protected area management. This is of
considerable importance in the Greek case, given the recent establishment of 27 administrative bodies of protected areas,
all of which are required to incorporate public consultation into management practices. 相似文献
994.
Many problems and challenges of ecosystem management currently are driven by the rapid pace and spatial extent of landscape
change. Parks and reserves within areas of high human population density are especially challenged to meet the recreational
needs of local populations and to preserve valued environmental resources. The complex problem of managing multiple objectives
and multiple resources requires an enormous quantity of information, and conceptual models have been proposed as tools for
organizing and interpreting this information. Academics generally prefer a bottom-up approach to model construction that emphasizes
ecologic theory and process, whereas managers often use a top-down approach that takes advantage of existing information to
address more pragmatic objectives. The authors propose a formal process for developing, applying, and testing conceptual models
to be used in landscape monitoring that reconciles these seemingly opposing perspectives. The four-step process embraces the
role of hypothesis testing in the development of models and evaluation of their utility. An example application of the process
to a network of national parks in and around Washington, DC illustrates the ability of the approach to systematically identify
monitoring data that would both advance ecologic theory and inform management decisions. 相似文献
995.
We present a framework of a scenario-based model that simulates the development of the municipality of Davos (Swiss Alps).
We illustrate our method with the calculation of the scenario for 2050 “Decrease in subsidies for mountain agriculture and liberalization of markets.” The main objective was to link submodels of land-use allocation (regression-based approach), material and energy flows submodels
(Material and Energy Flux Analysis), and economic submodels (Input–Output Analysis). Letting qualitative and quantitative
information flow from one submodel to the next, following the storyline describing a scenario, has proven to be suitable for
linking submodels. The succession of the submodels is then strongly dependent on the scenario. Qualitative information flows
are simulated with microsimulations of actor choices. Links between the submodels show different degrees of robustness: although
the links involving microsimulations are the weakest, the uncertainty introduced by the land-use allocation model is actually
advantageous because it allows one possible change in the landscape in the future to be simulated. The modeling results for
the scenario here presented show that the disappearance of agriculture only marginally affects the region’s factor income,
but that the consequences for the self-sufficiency rate, for various landscape-related indicators and ecosystem services,
and for the economy in the long term may be considerable. These benefits compensate for agriculture’s modest direct economic
value. The framework presented can potentially be applied to any region and scenario. This framework provides a basis for
a learning package that allows potential detrimental consequences of regional development to be anticipated at an early stage. 相似文献
996.
Historical and recent remote sensing data can be used to address temporal and spatial relationships between upland land cover and downstream vegetation response at the watershed scale. This is demonstrated for sub-watersheds draining into Elkhorn Slough, California, where salt marsh habitat has diminished because of the formation of sediment fans that support woody riparian vegetation. Multiple regression models were used to examine which land cover variables and physical properties of the watershed most influenced sediment fan size within 23 sub-watersheds (1.4 ha to 200 ha). Model explanatory power increased (adjusted R(2) = 0.94 vs. 0.75) among large sub-watersheds (>10 ha) and historical watershed variables, such as average farmland slope, flowpath slope, and flowpath distance between farmland and marsh, were significant. It was also possible to explain the increase in riparian vegetation by historical watershed variables for the larger sub-watersheds. Sub-watershed area is the overriding physical characteristic influencing the extent of sedimentation in a salt marsh, while percent cover of agricultural land use is the most influential land cover variable. The results also reveal that salt marsh recovery depends on relative cover of different land use classes in the watershed, with greater chances of recovery associated with less intensive agriculture. This research reveals a potential delay between watershed impacts and wetland response that can be best revealed when conducting multi-temporal analyses on larger watersheds. 相似文献
997.
Preliminary surveys are used to prioritize between contaminated sites to select those to be investigated more thoroughly. The data-gathering steps are almost identical between countries; however, the assessment procedures differ significantly. In this study, we have investigated 21 contaminated sites assessed as belonging to the high-risk or the very high-risk class using the Swedish Methods for Inventories of Contaminated Sites (MICS). We then applied the US Preliminary Assessment (PA) method to the same sites and compared the results and conclusions from the two screening procedures. In both cases, all sites were recommended for further investigation and the two approaches seem to corroborate one another; however, the PA assessment scores and the preliminary MICS classifications did not correlate. The results obtained with the PA method were easier to explain than the final MICS classification. The PA method also seems more transparent and easier to standardize, although objections could be made regarding the weighting scheme, because the outcome in this study was entirely dependent on the surface exposure pathway. However, to examine this in greater detail, it is necessary to include sites with less contamination: The importance of preliminary surveys in the overall risk management process gives a strong motivation for such an evaluation. Generally, the lack of research and scientific support for the various assessment procedures in use suggests that there is a need for method development, standardization, and validation. 相似文献
998.
Increasingly, performance measurement is being used to hold federal agencies accountable, represent environmental progress, and evaluate the effectiveness of environmental programs. The need to track measurable outputs has created a tendency to present programmatic progress solely by quantifiable data, despite the inherent complexity of natural resource management. Wetlands and fire management programs are two specific environmental arenas that have come to overemphasize the tracking of acreage numbers to validate existing policy direction. In both of these arenas, we find the definition and categorization of "countable" acres to be inconsistent and unreliable. We explore this systemic flaw for both wetlands and fire programs and describe its implications for environmental policy and natural resource management more broadly. We conclude with recommendations for improved performance measurement in these arenas. 相似文献
999.
Using GIS to Generate Spatially Balanced Random Survey Designs for Natural Resource Applications 总被引:2,自引:0,他引:2
Theobald DM Stevens DL White D Urquhart NS Olsen AR Norman JB 《Environmental management》2007,40(1):134-146
Sampling of a population is frequently required to understand trends and patterns in natural resource management because financial
and time constraints preclude a complete census. A rigorous probability-based survey design specifies where to sample so that
inferences from the sample apply to the entire population. Probability survey designs should be used in natural resource and
environmental management situations because they provide the mathematical foundation for statistical inference. Development
of long-term monitoring designs demand survey designs that achieve statistical rigor and are efficient but remain flexible
to inevitable logistical or practical constraints during field data collection. Here we describe an approach to probability-based
survey design, called the Reversed Randomized Quadrant-Recursive Raster, based on the concept of spatially balanced sampling
and implemented in a geographic information system. This provides environmental managers a practical tool to generate flexible
and efficient survey designs for natural resource applications. Factors commonly used to modify sampling intensity, such as
categories, gradients, or accessibility, can be readily incorporated into the spatially balanced sample design. 相似文献
1000.