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1.
/ A watershed-based approach for screening-level assessment of nonpoint source pollution from inactive and abandoned metal mines was developed and illustrated. The methodology was designed to use limited stream discharge and chemical data from synoptic surveys to derive key information required for targeting impaired waterbodies and critical source areas for detailed investigation and remediation. The approach was formulated based on the required attributes of an assessment methodology, information goals for targeting, attributes of data that are typical of basins with inactive mines, and data analysis methods that were useful for the case study. The methodology is presented as steps in a framework including evaluation of existing data/information and identification of data gaps; definition of assessment information goals for targeting and monitoring design; data collection, management, and analysis; and information reporting and use for targeting. Information generated includes the type and extent of and critical conditions for water-quality impairment, concentrations in and loadings to streams, differences between concentrations in and loadings to streams, and risks of exceeding target concentrations and loadings. Data from the Cement Creek Basin, located in the San Juan Mountains of southwestern Colorado, USA, were used to help develop and illustrate application of the methodology. The required information was derived for Cement Creek and used for preliminary targeting of locations for detailed investigation and remediation. Application of the approach to Cement Creek was successful in terms of cost-effective generation of information and use for targeting.KEY WORDS: Water quality assessment; Nonpoint source pollution; Inactive mines; Watershed 相似文献
2.
Relationships Between Landscape Characteristics and Nonpoint Source Pollution Inputs to Coastal Estuaries 总被引:24,自引:0,他引:24
The model can help in examining the relative sensitivity of water-quality variables to alterations in land use made at varying
distances from the stream channel. The model also shows the importance of streamside management zones, which are key to maintenance
of stream water quality. The linkage model can be considered a first step in the integration of GIS and ecological models.
The model can then be used by local and regional land managers in the formulation of plans for watershed-level management. 相似文献
3.
Setting Priorities for Research on Pollution Reduction Functions of Agricultural Buffers 总被引:4,自引:0,他引:4
Dosskey MG 《Environmental management》2002,30(5):0641-0650
The success of buffer installation initiatives and programs to reduce nonpoint source pollution of streams on agricultural
lands will depend the ability of local planners to locate and design buffers for specific circumstances with substantial and
predictable results. Current predictive capabilities are inadequate, and major sources of uncertainty remain. An assessment
of these uncertainties cautions that there is greater risk of overestimating buffer impact than underestimating it.
Priorities for future research are proposed that will lead more quickly to major advances in predictive capabilities. Highest
priority is given for work on the surface runoff filtration function, which is almost universally important to the amount
of pollution reduction expected from buffer installation and for which there remain major sources of uncertainty for predicting
level of impact. Foremost uncertainties surround the extent and consequences of runoff flow concentration and pollutant accumulation.
Other buffer functions, including filtration of groundwater nitrate and stabilization of channel erosion sources of sediments,
may be important in some regions. However, uncertainty surrounds our ability to identify and quantify the extent of site conditions
where buffer installation can substantially reduce stream pollution in these ways.
Deficiencies in predictive models reflect gaps in experimental information as well as technology to account for spatial heterogeneity
of pollutant sources, pathways, and buffer capabilities across watersheds. Since completion of a comprehensive watershed-scale
buffer model is probably far off, immediate needs call for simpler techniques to gage the probable impacts of buffer installation
at local scales. 相似文献
4.
Landscape Planning for Agricultural Nonpoint Source Pollution Reduction I: A Geographical Allocation Framework 总被引:1,自引:1,他引:0
Agricultural nonpoint source pollution remains a persistent environmental problem, despite the large amount of money that
has been spent on its abatement. At local scales, agricultural best management practices (BMPs) have been shown to be effective
at reducing nutrient and sediment inputs to surface waters. However, these effects have rarely been found to act in concert
to produce measurable, broad-scale improvements in water quality. We investigated potential causes for this failure through
an effort to develop recommendations for the use of riparian buffers in addressing nonpoint source pollution in Wisconsin.
We used frequency distributions of phosphorus pollution at two spatial scales (watershed and field), along with typical stream
phosphorus (P) concentration variability, to simulate benefit/cost curves for four approaches to geographically allocating
conservation effort. The approaches differ in two ways: (1) whether effort is aggregated within certain watersheds or distributed
without regard to watershed boundaries (dispersed), and (2) whether effort is targeted toward the most highly P-polluting
fields or is distributed randomly with regard to field-scale P pollution levels. In realistic implementation scenarios, the
aggregated and targeted approach most efficiently improves water quality. For example, with effort on only 10% of a model
landscape, 26% of the total P load is retained and 25% of watersheds significantly improve. Our results indicate that agricultural
conservation can be more efficient if it accounts for the uneven spatial distribution of potential pollution sources and the
cumulative aspects of environmental benefits. 相似文献
5.
Landscape Planning for Agricultural Nonpoint Source Pollution Reduction III: Assessing Phosphorus and Sediment Reduction Potential 总被引:2,自引:0,他引:2
Riparian buffers have the potential to improve stream water quality in agricultural landscapes. This potential may vary in
response to landscape characteristics such as soils, topography, land use, and human activities, including legacies of historical
land management. We built a predictive model to estimate the sediment and phosphorus load reduction that should be achievable
following the implementation of riparian buffers; then we estimated load reduction potential for a set of 1598 watersheds
(average 54 km2) in Wisconsin. Our results indicate that land cover is generally the most important driver of constituent loads in Wisconsin
streams, but its influence varies among pollutants and according to the scale at which it is measured. Physiographic (drainage
density) variation also influenced sediment and phosphorus loads. The effect of historical land use on present-day channel
erosion and variation in soil texture are the most important sources of phosphorus and sediment that riparian buffers cannot
attenuate. However, in most watersheds, a large proportion (approximately 70%) of these pollutants can be eliminated from
streams with buffers. Cumulative frequency distributions of load reduction potential indicate that targeting pollution reduction
in the highest 10% of Wisconsin watersheds would reduce total phosphorus and sediment loads in the entire state by approximately
20%. These results support our approach of geographically targeting nonpoint source pollution reduction at multiple scales,
including the watershed scale. 相似文献
6.
In recent years, improvements in point-source depuration technologies have highlighted the problems regarding agricultural
nonpoint (diffuse) sources, and this issue has become highly relevant from the environmental point of view. The considerable
extension of the areas responsible for this kind of pollution, together with the scarcity of funds available to local managers,
make minimizing the impacts of nonpoint sources on a whole basin a virtually impossible task. This article presents the results
of a study intended to pinpoint those agricultural areas, within a basin, that contribute most to water pollution, so that
operations aimed at preventing and/or reducing this kind of pollution can be focused on them. With this aim, an innovative
approach is presented that integrates a field-scale management model, a simple regression model, and a geographic information
system (GIS). The Lake Vico basin, where recent studies highlighted a considerable increase in the trophic state, mainly caused
by phosphorus (P) compounds deriving principally from the intensive cultivation of hazelnut trees in the lake basin, was chosen
as the study site. Using the management model Groundwater Loading Effects of Agricultural Management Systems (GLEAMS), the
consequences, in terms of sediment yield and phosphorus export, of hazelnut tree cultivation were estimated on different areas
of the basin with and without the application of a best management practice (BMP) that consists of growing meadow under the
trees. The GLEAMS results were successively extended to basin scale thanks to the application of a purposely designed regression
model and of a GIS.
The main conclusions can be summarized as follows: The effectiveness of the above-mentioned BMP is always greater for erosion
reduction than for particulate P reduction, whatever the slope value considered; moreover, the effectiveness with reference
to both particulate P and sediment yield production decreases as the slope increases. The proposed approach, being completely
distributed, represents a considerable step ahead compared to the semidistributed or lumped approaches, which are traditionally
employed in research into tools to support the decision-making process for land-use planning aimed at water pollution control. 相似文献
7.
Reducing Nonpoint Source Pollution Through Collaboration: Policies and Programs Across the U.S. States 总被引:1,自引:1,他引:1
Nonpoint source (NPS) pollution has emerged as the largest threat to water quality in the United States, influencing policy
makers and resource managers to direct more attention toward NPS prevention and remediation. In response, the United States
Environmental Protection Agency (USEPA) spent more than $204 million in fiscal year (FY) 2006 on the Clean Water Act’s Section
319 program to combat NPS pollution, much of it on the development and implementation of watershed-based plans. State governments
have also increasingly allocated financial and technical resources to collaborative watershed efforts within their own borders
to fight NPS pollution. With increased collaboration among the federal government, states, and citizens to combat NPS pollution,
more information is needed to understand how public resources are being used, by whom, and for what, and what policy changes
might improve effectiveness. Analysis from a 50-state study suggests that, in addition to the average 35% of all Section 319
funds per state that are passed on to collaborative watershed groups, 35 states have provided financial assistance beyond
Section 319 funding to support collaborative watershed initiatives. State programs frequently provide technical assistance
and training, in addition to financial resources, to encourage collaborative partnerships. Such assistance is typically granted
in exchange for requirements to generate a watershed action plan and/or follow a mutually agreed upon work plan to address
NPS pollution. Program managers indicated a need for greater fiscal resources and flexibility to achieve water quality goals. 相似文献
8.
Managing Nonpoint Source Pollution in Western Washington: Landowner Learning Methods and Motivations 总被引:1,自引:1,他引:0
Clare M. Ryan 《Environmental management》2009,43(6):1122-1130
States, territories, and tribes identify nonpoint source pollution as responsible for more than half of the Nation’s existing
and threatened water quality impairments, making it the principal remaining cause of water quality problems across the United
States. Combinations of education, technical and financial assistance, and regulatory measures are used to inform landowners
about nonpoint source pollution issues, and to stimulate the use of best management practices. A mail survey of non-commercial
riparian landowners investigated how they learn about best management practices, the efficacy of different educational techniques,
and what motivates them to implement land management activities. Landowners experience a variety of educational techniques,
and rank those that include direct personal contact as more effective than brochures, advertisements, radio, internet, or
television. The most important motivations for implementing best management practices were linked with elements of a personal
stewardship ethic, accountability, personal commitment, and feasibility. Nonpoint source education and social marketing campaigns
should include direct interpersonal contacts, and appeal to landowner motivations of caring, responsibility, and personal
commitment. 相似文献
9.
The Southeastern United States is a global center of freshwater biotic diversity, but much of the regions aquatic biodiversity is at risk from stream degradation. Nonpoint pollution sources are responsible for 70% of that degradation, and controlling nonpoint pollution from agriculture, urbanization, and silviculture is considered critical to maintaining water quality and aquatic biodiversity in the Southeast. We used an ecological risk assessment framework to develop vulnerability models that can help policymakers and natural resource managers understand the impact of land cover changes on water quality in North Carolina. Additionally, we determined which landscape characteristics are most closely associated with macroinvertebrate community tolerance of stream degradation, and therefore with lower-quality water. The results will allow managers and policymakers to weigh the risks of management and policy decisions to a given watershed or set of watersheds, including whether streamside buffer protection zones are ecologically effective in achieving water quality standards. Regression analyses revealed that landscape variables explained up to 56.3% of the variability in benthic macroinvertebrate index scores. The resulting vulnerability models indicate that North Carolina watersheds with less forest cover are at most risk for degraded water quality and steam habitat conditions. The importance of forest cover, at both the watershed and riparian zone scale, in predicting macrobenthic invertebrate community assemblage varies by geographic region of the state. 相似文献
10.
Development and Adoption of a Simple Nonpoint Source Pollution Model for Port Phillip Bay,Australia 总被引:1,自引:0,他引:1
New computing tools and approaches allow tailored development of software to meet the needs of environmental managers. The processes required for such tailoring fit well with adaptive management concepts where, as knowledge and system understanding develop among managers, the software can be developed or replaced to match. This paper reports on development and adoption of a simple nonpoint source pollution modeling tool, including technical aspects of data support for modeling and social aspects of software design. The software, named FILTER, used a unit load model to generate expected pollutant loads from subcatchments of Port Phillip Bay, Australia. Monitoring data were used for calibration to modify the delivery of generated pollutants to receiving waters. Spatial, tabular, and charting software components were used to provide alternative forms of output visualization. FILTER was developed using a process that resulted in manager-stakeholders taking responsibility for setting of model parameter values and operation of the user interface, thereby encouraging uptake. The inclusive development process, tailoring of the software to manager needs and styles of usage, and matching of model complexity to data and knowledge, resulted in a successful application that has become the current agreed system representation among disparate stakeholder organizations. 相似文献
11.
Nonpoint Source Pollution Responses Simulation for Conversion Cropland to Forest in Mountains by SWAT in China 总被引:1,自引:0,他引:1
Several environmental protection policies have been implemented to prevent soil erosion and nonpoint source (NPS) pollutions
in China. After severe Yangtze River floods, the “conversion cropland to forest policy” (CCFP) was carried out throughout
China, especially in the middle and upper reaches of Yangtze River. The research area of the current study is located in Bazhong
City, Sichuan Province in Yangtze River watershed, where soil erosion and NPS pollution are serious concerns. Major NPS pollutants
include nitrogen (N) and phosphorus (P). The objective of this study is to evaluate the long-term impact of implementation
of the CCFP on stream flow, sediment yields, and the main NPS pollutant loading at watershed level. The Soil and Water Assessment
Tool (SWAT) is a watershed environmental model and is applied here to simulate and quantify the impacts. Four scenarios are
constructed representing different patterns of conversion from cropland to forest under various conditions set by the CCFP.
Scenario A represented the baseline, i.e., the cropland and forest area conditions before the implementation of CCFP. Scenario
B represents the condition under which all hillside cropland with slope larger than 25° was converted into forest. In scenario
C and D, hillside cropland with slope larger than 15° and 7.5° was substituted by forest, respectively. Under the various
scenarios, the NPS pollution reduction due to CCFP implementation from 1996–2005 is estimated by SWAT. The results are presented
as percentage change of water flow, sediment, organic N, and organic P at watershed level. Furthermore, a regression analysis
is conducted between forest area ratio and ten years’ average NPS load estimations, which confirmed the benefits of implementing
CCFP in reducing nonpoint source pollution by increasing forest area in mountainous areas. The reduction of organic N and
organic P is significant (decrease 42.1% and 62.7%, respectively) at watershed level. In addition, this study also proves
that SWAT modeling approach can be used to estimate NPS pollutants’ impacts of land use conversions in large watershed. 相似文献
12.
13.
California’s population increased 25% between 1980 and 1990, resulting in rapid and extensive urbanization. Of a total 123,000
ha urbanized in 42 of the state’s 58 counties between 1984 and 1990, an estimated 13% occurred on irrigated prime farmland,
and 48% on wildlands or fallow marginal farmlands. Sixty-six percent of all new irrigated farmland put into production between
1984 and 1990 was of lesser quality than the prime farmland taken out of production by urbanization. Factors dictating the
agricultural development of marginal farmlands include the availability and price of water and land, agricultural commodity
prices, and technical innovations such as drip irrigation systems that impact the feasibility and costs of production. The
increasing amount of marginal farmland being put into production could have significant water quality consequences because
marginal lands are generally steeper, have more erodible soils, poorer drainage, and require more fertilizer than prime farmlands.
Although no data exist to test our hypothesis, and numerous variables preclude definitive predictions, the evidence suggests
that new irrigated marginal lands can increase nonpoint source (NPS) pollution for a given size area by an order of magnitude
in some cases. 相似文献
14.
秦皇岛市农业面源污染特征分析 总被引:1,自引:0,他引:1
代伟 《中国环境管理干部学院学报》2013,(5):43-45,62
对2011年秦皇岛市农业污染源进行分析并测算各污染物排放量,结果表明,农业面源COD排放量为38768.27t,NH3-N为7593.71t,TN为15684.63t,TP为7821.18t;昌黎县是秦皇岛市农业面源污染最重的污染区域;农村生活源对COD排放量的贡献率最大,种植业对NH3-N、TN和TP排放量的贡献率最大。 相似文献
15.
农业面源污染的政策成因分析 总被引:1,自引:0,他引:1
从农业发展政策的角度出发,分析了农业发展政策从制定、执行到监督的环节中影响农业面源污染防治效果的因素;指出面源污染日益严重的政策成因是现有农业发展政策与农村环境保护体系的双轨制脱钩运行;建议构建一套把农业发展与农村环境保护有效地协调在可持续发展框架内的生态农业政策体系。 相似文献
16.
立足天津市滨海新区大港农业背景情况,采用适宜的方法,分别从种植业、畜禽养殖和水产养殖业三方面分析非点源污染物排放量。结果表明:2010年大港地区农业非点源主要污染物COD排放量为377.67 t,氨氮排放量为72.33 t,畜禽养殖排放的污染已占农业非点源污染的一半以上。在此基础上,分别从优化畜禽养殖的养殖模式、种植业科学施用化学品、水产养殖合理投放饲料等方面提出了大港地区农业非点源污染控制的对策。 相似文献
17.
农业非点源污染目前已成为全球水污染的主要来源。对我国农业非点源污染成因的分析表明:农药、化肥的大量使用,不同灌溉方式、生产生活废弃物和规模化畜禽养殖等与农业非点源污染的形成之间均有密切的关系,应从农田径流控制、小流域综合治理、发展生态农业等方面开展农业非点源污染防治。实施农田养分最佳管理技术、开发农业非点源污染管理应用软件、完善农业生态补偿机制将成为我国农业非点源污染研究的发展趋势。 相似文献
18.
农田面源污染是洱海富营养化的重要原因之一。本文利用在洱海北部地区收集的实地调研数据,从化肥施用与流失和秸秆利用情况,分析了该地区的农田面源污染现状。结果表明:该地区的农田面源污染主要来源于大蒜田与玉米田的氮磷流失,以及大蒜秸秆与玉米秸秆的焚烧或丢弃。从补偿对象与主体、补偿标准、补偿环节与方式、配套政策四个方面,探讨了农田面源污染控制的补偿政策,并结合在洱海北部地区的实地调研资料,分析了测土配方施肥和秸秆还田两种农田面源污染控制技术采纳的补偿政策案例;提出政府应在基础设施建设、技术指导、教育培训、"无公害"农产品市场建设等方面给予政策支持。 相似文献
19.
阐述了农业面源污染的主要来源及危害,指出农业面源污染是当前农业可持续发展的主要障碍之一。由于我国农村过量和不合理地使用农药、化肥、地膜等,造成了农业面源不同程度的污染,给农业生产和农民生活带来了隐患,直接关系到农业可持续发展,应该采取有效措施加以解决。 相似文献
20.
根据国内外农业非点源污染研究现状,本文在探讨农业非点源污染内涵及其特征的基础上,简要总结了农业非点源污染负荷的估算模型,列举区域农业非点源污染风险评估的手段和方法,从不同角度归纳了农业非点源污染的控制技术,并提出了近期农业非点源污染急需研究的热点和趋势,以期为进一步的农业非点源污染管理和控制提供参考。 相似文献