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1.
Danz NP Niemi GJ Regal RR Hollenhorst T Johnson LB Hanowski JM Axler RP Ciborowski JJ Hrabik T Brady VJ Kelly JR Morrice JA Brazner JC Howe RW Johnston CA Host GE 《Environmental management》2007,39(5):631-647
Integrated, quantitative expressions of anthropogenic stress over large geographic regions can be valuable tools in environmental research and management. Despite the fundamental appeal of a regional approach, development of regional stress measures remains one of the most important current challenges in environmental science. Using publicly available, pre-existing spatial datasets, we developed a geographic information system database of 86 variables related to five classes of anthropogenic stress in the U.S. Great Lakes basin: agriculture, atmospheric deposition, human population, land cover, and point source pollution. The original variables were quantified by a variety of data types over a broad range of spatial and classification resolutions. We summarized the original data for 762 watershed-based units that comprise the U.S. portion of the basin and then used principal components analysis to develop overall stress measures within each stress category. We developed a cumulative stress index by combining the first principal component from each of the five stress categories. Maps of the stress measures illustrate strong spatial patterns across the basin, with the greatest amount of stress occurring on the western shore of Lake Michigan, southwest Lake Erie, and southeastern Lake Ontario. We found strong relationships between the stress measures and characteristics of bird communities, fish communities, and water chemistry measurements from the coastal region. The stress measures are taken to represent the major threats to coastal ecosystems in the U.S. Great Lakes. Such regional-scale efforts are critical for understanding relationships between human disturbance and ecosystem response, and can be used to guide environmental decision-making at both regional and local scales. 相似文献
2.
Assessing Risk in Operational Decisions Using Great Lakes Probabilistic Water Level Forecasts 总被引:1,自引:0,他引:1
/ A method adapted from the National Weather Service's Extended Streamflow Prediction technique is applied retrospectively to three Great Lakes case studies to show how risk assessment using probabilistic monthly water level forecasts could have contributed to the decision-mak-ing process. The first case study examines the 1985 International Joint Commission (IJC) decision to store water in Lake Superior to reduce high levels on the downstream lakes. Probabilistic forecasts are generated for Lake Superior and Lakes Michigan-Huron and used with riparian inundation value functions to assess the relative impacts of the IJC's decision on riparian interests for both lakes. The second case study evaluates the risk of flooding at Milwaukee, Wisconsin, and the need to implement flood-control projects if Lake Michigan levels were to continue to rise above the October 1986 record. The third case study quantifies the risks of impaired municipal water works operation during the 1964-1965 period of extreme low water levels on Lakes Huron, St. Clair, Erie, and Ontario. Further refinements and other potential applications of the probabilistic forecast technique are discussed.KEY WORDS: Great Lakes; Water levels; Forecasting; Risk; Decision making 相似文献
3.
As complex social phenomena, public involvement processes are influenced by contextual factors. This study examined agency
goals for public involvement and assessed the importance of local context in remedial action planning, a community-based water
resources program aimed at the cleanup of the 42 most polluted locations in the Great Lakes Basin. Agency goals for public
involvement in remedial action plans (RAPs) were agency-oriented and focused on public acceptance of the plan, support for
implementation, and positive agency-public relations. Corresponding to these goals, citizen advisory committees were created
in 75% of the RAP sites as a primary means for public input into the planning process. Factors that influenced the implementation
of public involvement programs in remedial action planning included public orientation toward the remediation issue, local
economic conditions, the interaction of diverse interests in the process, agency and process credibility, experience of local
leadership, and jurisdictional complexity. A formative assessment of “community readiness” appeared critical to appropriate
public involvement program design. Careful program design may also include citizen education and training components, thoughtful
management of ongoing agency-public relations and conflict among disparate interests in the process, overcoming logistical
difficulties that threaten program continuity, using local expertise and communication channels, and circumventing interjurisdictional
complexities. 相似文献
4.
Contaminated sediments are receiving increasing recognition around the world, leading to the development of various sediment quality indicators for assessment, management, remediation, and restoration efforts. Sediment chemistry represents an important indicator of ecosystem health, with the concentrations of contaminants of potential concern (COPCs) providing measurable characteristics for this indicator. The St. Louis River Area of Concern (AOC), located in the western arm of Lake Superior, provides a case study for how numerical sediment quality targets (SQTs) for the protection of sediment-dwelling organisms can be used to support the interpretation of sediment chemistry data. Two types of SQTs have been established for 33 COPCs in the St. Louis River AOC. The Level I SQTs define the concentrations of contaminants below which sediment toxicity is unlikely to occur, whereas the Level II SQTs represent the concentrations that, if exceeded, are likely to be associated with sediment toxicity. The numerical SQTs provide useful tools for making sediment management decisions, especially when considered as part of a weight-of-evidence approach that includes other sediment quality indicators, such as sediment contaminant chemistry and geochemical characteristics, sediment toxicity, and benthic macroinvertebrate community structure. The recommended applications of using the numerical SQTs in the St. Louis River AOC include: designing monitoring programs, interpreting sediment chemistry data, conducting ecological risk assessments, and developing site-specific sediment quality remediation targets for small, simple sites where adverse biological effects are likely. Other jurisdictions may benefit from using these recommended applications in their own sediment quality programs. 相似文献
5.
We used a GIS-based approach to examine the influence of road density and physical watershed features (watershed size, wetland
cover, and bedrock type) on water quality in coastal marshes of Georgian Bay, Ontario. We created a GIS that included landscape
information and water-quality data from a 9-year synoptic survey of 105 coastal marshes covering 28 quaternary watersheds.
Multiple regressions and partial correlations were used to discern confounding effects of human-induced (road density) versus
natural physical watershed determinants of water quality. Road density was the dominant factor influencing many water quality
variables, showing positive correlations with specific conductivity (COND), total suspended solids (TSS), and inorganic suspended
solids (ISS) and a negative correlation with overall Water Quality Index scores. Road density also showed positive correlations
with total nitrate nitrogen (TNN) and total phosphorus (TP). By comparison, larger watershed area was the main factor leading
to elevated TP concentrations. The proportion of the watershed occupied by wetlands explained the largest amount of variation
in TNN concentrations (negative correlation) and was also negatively correlated with COND and positively correlated with TSS
and ISS when we controlled for road density. Bedrock type did not have a significant effect in any of the models. Our findings
suggest that road density is currently the overriding factor governing water quality of coastal marshes in Georgian Bay during
the summer low-flow period. We recommend that natural variation in physical watershed characteristics be considered when developing
water quality standards and management practices for freshwater coastal areas. 相似文献
6.
Methodological Development of an Index of Coastal Water Quality: Application in a Tourist Area 总被引:2,自引:0,他引:2
With the aim of obtaining an index of coastal water quality, a methodological procedure based on numerical classification and discriminant analysis is presented. The procedure was applied to nutrient data (ammonia, nitrite, nitrate, and phosphate) analyzed along the coastal waters of a Spanish tourist area. Using numerical classification, three levels of nutrient loading were revealed, characterizing oligotrophic, mesotrophic, and potentially eutrophic waters. Discriminant analysis was shown to be an effective methodological tool in the discrimination between trophic groups. For every group, the discriminant procedure generated the centroids. The centroids representing oligotrophic and potentially eutrophic conditions were used to establish the two extremes of the continuum of mesotrophic conditions in these coastal waters: Standardizing values from -1 to 1, the centroids for oligotrophic and potentially eutrophic waters yielded an interval that defined the range of mesotrophic conditions. This interval is proposed as a water quality index. The ability of the coastal water quality index to successfully predict mesotrophic conditions was proved with random samples. 相似文献
7.
Headwater Influences on Downstream Water Quality 总被引:2,自引:0,他引:2
We investigated the influence of riparian and whole watershed land use as a function of stream size on surface water chemistry
and assessed regional variation in these relationships. Sixty-eight watersheds in four level III U.S. EPA ecoregions in eastern
Kansas were selected as study sites. Riparian land cover and watershed land use were quantified for the entire watershed,
and by Strahler order. Multiple regression analyses using riparian land cover classifications as independent variables explained
among-site variation in water chemistry parameters, particularly total nitrogen (41%), nitrate (61%), and total phosphorus
(63%) concentrations. Whole watershed land use explained slightly less variance, but riparian and whole watershed land use
were so tightly correlated that it was difficult to separate their effects. Water chemistry parameters sampled in downstream
reaches were most closely correlated with riparian land cover adjacent to the smallest (first-order) streams of watersheds
or land use in the entire watershed, with riparian zones immediately upstream of sampling sites offering less explanatory
power as stream size increased. Interestingly, headwater effects were evident even at times when these small streams were
unlikely to be flowing. Relationships were similar among ecoregions, indicating that land use characteristics were most responsible
for water quality variation among watersheds. These findings suggest that nonpoint pollution control strategies should consider
the influence of small upland streams and protection of downstream riparian zones alone is not sufficient to protect water
quality. 相似文献
8.
William S. Breffle Daya Muralidharan Richard P. Donovan Fangming Liu Amlan Mukherjee Yongliang Jin 《Resources Policy》2013
The Great Lakes watershed is home to over 40 million people (Canadian and U.S.) who depend on a healthy Great Lakes ecosystem for economic, societal, and personal vitality. The challenge to policymakers and the public is to balance economic benefits with the need to conserve and replenish regional natural resources in a manner that ensures long term prosperity. Nine critical broad-spectrum stressors of ecological services are identified, which include pollution and contamination, agricultural erosion, non-native species, degraded recreational resources, loss of wetlands habitat, climate change, risk of clean water shortage, vanishing sand dunes, and population overcrowding. Many of these stressors overlap. For example, mining activities alone can create stress in at least five of these categories. The focus groups were conducted to examine the public’s awareness of, concern with, and willingness to expend resources on these stressors. This helped generate a grouping of stressors that the public is especially concerned about, those they care little about, and everything else in between. Stressors that the respondents have direct contact with tend to be the most important to them. This approach of using focus groups is a critical first step in helping natural resource managers such as Trustees and NGOs understand what subsequent steps to take and develop policy measures that are of most interest and value to the public. Skipping or glossing over this key first task could lead to difficulties with respect to survey design and model development in a non-market valuation study. The focus group results show that concern related to pollution and contamination is much higher than for any of the others. It is thus clear that outreach programs may be necessary to educate the public about the severity of some low-ranked stressors including climate change. 相似文献
9.
Landsat ETM+ Images in the Estimation of Seasonal Lake Water Quality in Boreal River Basins 总被引:2,自引:0,他引:2
Kallio K Attila J Härmä P Koponen S Pulliainen J Hyytiäinen UM Pyhälahti T 《Environmental management》2008,42(3):511-522
We investigated the use of Landsat ETM+ images in the monitoring of turbidity, colored dissolved organic matter (CDOM), and Secchi disk transparency (Z(SD)) in lakes of two river basins located in southern Finland. The ETM+ images were acquired in May, June, and September 2002 and were corrected for atmospheric disturbance using the simplified method of atmospheric correction (SMAC) model. The in situ measurements consisted of water sampling in the largest lake of the region, routine monitoring results for the whole study area, and Z(SD) observations made by volunteers. The ranges of the water quality variables in the dataset were as follows: turbidity, 0.6-25 FNU; absorption coefficient of CDOM at 400 nm, 1.0-12.2 m(-1); Z(SD), 0.5-5.5 m; and chlorophyll a concentration, 2.4-80 mug L(-1). The estimation accuracies of the image-specific empirical algorithms expressed as relative errors were 23.0% for turbidity, 17.4% for CDOM, and 21.1% for Z(SD). If concurrent in situ measurements had not been used for algorithm training, the average error would have been about 37%. The atmospheric correction improved the estimation accuracy only slightly compared with the use of top-of-atmospheric reflectances. The accuracy of the water quality estimates without concurrent in situ measurements could have been improved if in-image atmospheric parameters had been available. The underwater reflectance simulations of the ETM+ channel wavelengths using water quality typical for Finnish lakes (data from 1113 lakes) indicated that region-specific algorithms may be needed in other parts of the country, particularly in the case of Z(SD). Despite the limitations in the spectral and radiometric resolutions, ETM+ imagery can be an effective aid, particularly in the monitoring and management of small lakes (<1 km(2)), which are often not included in routine monitoring programs. 相似文献
10.
Kramer DB Polasky S Starfield A Palik B Westphal L Snyder S Jakes P Hudson R Gustafson E 《Environmental management》2006,38(3):411-425
Roughly 45% of the assessed lakes in the United States are impaired for one or more reasons. Eutrophication due to excess
phosphorus loading is common in many impaired lakes. Various strategies are available to lake residents for addressing declining
lake water quality, including septic system upgrades and establishing riparian buffers. This study examines 25 lakes to determine
whether septic upgrades or riparian buffers are a more cost-effective strategy to meet a phosphorus reduction target. We find
that riparian buffers are the more cost-effective strategy in every case but one. Large transaction costs associated with
the negotiation and monitoring of riparian buffers, however, may be prohibiting lake residents from implementing the most
cost-effective strategy.
An erratum to this article is available at . 相似文献
11.
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
12.
We analyzed the effects of changes in land cover on the water balance in Spain’s Marina Baixa County, on the Mediterranean
coast. To reveal how different land management strategies have affected the area’s environment, four municipalities within
the same catchment were studied: Benidorm, Callosa d’en Sarrià, Beniardà, and Guadalest. In the municipalities of Callosa
and Benidorm, the proportion of the area covered by woodland declined by 4.2% and 30.2%, respectively, and woodland was replaced
by agriculture and urban development. The abandonment of farmland produced a 17% increase in the proportion of the area covered
by vegetation in Guadalest and Beniardá, where frequent forest fires have exacerbated a decrease in the area of pine woodland.
Tourism development in Benidorm has been accompanied by an increase in the transportation infrastructure and by an expansion
of areas with an impermeable surface, with the lowest level of infiltration into the aquifer system. These changes have generated
a net water deficit in Callosa and Benidorm of more than 6 Mm3/year, creating a high demand for water imported from other municipalities (Guadalest and Beniardá) or from outside of the
county to maintain the sustainability of the current water management strategies. The Marina Baixa case study is representative
of many of the world’s coastal areas that are undergoing rapid urban development based on an inappropriate understanding of
human progress based mainly on economic development and thus provides insights into water management in other areas. 相似文献
13.
Lisa M. Smith John M. Macauley Linda C. Harwell Cynthia A. Chancy 《Environmental management》2009,44(1):149-162
Water quality was assessed following Hurricane Katrina in the affected waters of Alabama, Mississippi, and Louisiana. Post-landfall
water quality was compared to pre-hurricane conditions using indicators assessed by EPA’s National Coastal Assessment program
and additional indicators of contaminants in water and pathogens. Water quality data collected after Hurricane Katrina suggest
that the coastal waters affected by the storm exhibited higher salinity and concentrations of chlorophyll a, dissolved inorganic phosphorus, and total suspended solids following the storm compared to the previous 5-year averages.
Higher bottom dissolved oxygen concentrations and light attenuation were also observed. Contaminant concentrations measured
in the water column were very low or undetectable, as were the presence of pathogens. Overall water quality did not significantly
differ from water quality assessed in the five years preceding the storm. Statistical analyses indicate that use of a probabilistic
survey design is appropriate for making pre-storm and post storm comparisons for water quality condition on an areal basis.
The information in this article has been funded wholly (or in part) by the U.S. Environmental Protection Agency. It has been
subjected to review by the National Health and Environmental Effects Research Laboratory and approved for publication. Approval
does not signify that the contents reflect the views of the Agency, nor does mention of trade names or commercial products
constitute endorsement or recommendation for use. This is contribution number 1280 from the Gulf Ecology Division. 相似文献
14.
Many lakes have experienced a transition from a clear into a turbid state without macrophyte growth due to eutrophication.
There are several measures by which nitrogen (N) and phosphorus (P) concentrations in the surface water can be reduced. We
used the shallow lake model PCLake to evaluate the effects of three measures (reducing external nutrient loading, increasing
relative marsh area, and increasing exchange rate between open water and marsh) on water quality improvement. Furthermore,
the contribution of different retention processes was calculated. Settling and burial contributed more to nutrient retention
than denitrification. The model runs for a typical shallow lake in The Netherlands showed that after increasing relative marsh
area to 50%, total phosphorous (TP) concentration in the surface water was lower than the Maximum Admissible Risk (MAR, a
Dutch government water quality standard) level, in contrast to total nitrogen (TN) concentration. The MAR levels could also
be achieved by reducing N and P load. However, reduction of nutrient concentrations to MAR levels did not result in a clear
lake state with submerged vegetation. Only a combination of a more drastic reduction of the present nutrient loading, in combination
with a relatively large marsh cover (approximately 50%) would lead to such a clear state. We therefore concluded that littoral
marsh areas can make a small but significant contribution to lake recovery. 相似文献
15.
Since intensive farming practices are essential to produce enough food for the increasing population, farmers have been using
more inorganic fertilizers, pesticides, and herbicides. Agricultural lands are currently one of the major sources of non-point
source pollution. However, by changing farming practices in terms of tillage and crop rotation, the levels of contamination
can be reduced and the quality of soil and water resources can be improved. Thus, there is a need to investigate the amalgamated
hydrologic effects when various tillage and crop rotation practices are operated in tandem. In this study, the Soil Water
Assessment Tool (SWAT) was utilized to evaluate the individual and combined impacts of various farming practices on flow,
sediment, ammonia, and total phosphorus loads in the Little Miami River basin. The model was calibrated and validated using
the 1990–1994 and 1980–1984 data sets, respectively. The simulated results revealed that the SWAT model provided a good simulation
performance. For those tested farming scenarios, no-tillage (NT) offered more environmental benefits than moldboard plowing
(MP). Flow, sediment, ammonia, and total phosphorus under NT were lower than those under MP. In terms of crop rotation, continuous
soybean and corn–soybean rotation were able to reduce sediment, ammonia, and total phosphorus loads. When the combined effects
of tillage and crop rotation were examined, it was found that NT with continuous soybean or corn–soybean rotation could greatly
restrain the loss of sediments and nutrients to receiving waters. Since corn–soybean rotation provides higher economic revenue,
a combination of NT and corn–soybean rotation can be a viable system for successful farming. 相似文献
16.
A study of water quality, land use, and population variations over the past three decades was conducted in eastern Massachusetts
to examine the impact of urban sprawl on water quality using geographic information system and statistical analyses. Since
1970, eastern Massachusetts has experienced pronounced urban sprawl, which has a substantial impact on water quality. High
spatial correlations are found between water quality indicators (especially specific conductance, dissolved ions, including
Ca, Mg, Na, and Cl, and dissolved solid) and urban sprawl indicators. Urbanized watersheds with high population density, high
percentage of developed land use, and low per capita developed land use tended to have high concentrations of water pollutants.
The impact of urban sprawl also shows clear spatial difference between suburban areas and central cities: The central cities
experienced lower increases over time in specific conductance concentration, compared to suburban and rural areas. The impact
of urban sprawl on water quality is attributed to the combined effects of population and land-use change. Per capita developed
land use is a very important indicator for studying the impact of urban sprawl and improving land use and watershed management,
because inclusion of this indicator can better explain the temporal and spatial variations of more water quality parameters
than using individual land use or/and population density. 相似文献