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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
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A water quality index expressed as a single number is developed to describe overall water quality conditions using multiple water quality variables. The index consists of water quality variables: dissolved oxygen, specific conductivity, turbidity, total phosphorus, and fecal coliform. The objectives of this study were to describe the preexisting indices and to define a new water quality index that has advantages over these indices. The new index was applied to the Big Lost River Watershed in Idaho, and the results gave a quantitative picture for the water quality situation. If the new water quality index for the impaired water is less than a certain number, remediation—likely in the form of total maximum daily loads or changing the management practices—may be needed. The index can be used to assess water quality for general beneficial uses. Nevertheless, the index cannot be used in making regulatory decisions, indicate water quality for specific beneficial uses, or indicate contamination from trace metals, organic contaminants, and toxic substances. 相似文献
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How to Quantify Sustainable Development: A Risk-Based Approach to Water Quality Management 总被引:1,自引:0,他引:1
Since the term was coined in the Brundtland report in 1987, the issue of sustainable development has been challenged in terms
of quantification. Different policy options may lend themselves more or less to the underlying principles of sustainability,
but no analytical tools are available for a more in-depth assessment of the degree of sustainability. Overall, there are two
major schools of thought employing the sustainability concept in managerial decisions: those of measuring and those of monitoring.
Measurement of relative sustainability is the key issue in bridging the gap between theory and practice of sustainability
of water resources systems. The objective of this study is to develop a practical tool for quantifying and assessing the degree
of relative sustainability of water quality systems based on risk-based indicators, including reliability, resilience, and
vulnerability.
Current work on the Karoun River, the largest river in Iran, has included the development of an integrated model consisting
of two main parts: a water quality simulation subroutine to evaluate Dissolved Oxygen Biological Oxygen Demand (DO-BOD) response,
and an estimation of risk-based indicators subroutine via the First Order Reliability Method (FORM) and Monte Carlo Simulation
(MCS). We also developed a simple waste load allocation model via Least Cost and Uniform Treatment approaches in order to
consider the optimal point of pollutants control costs given a desired reliability value which addresses DO in two different
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The Risk-based approach developed herein, particularly via the FORM technique, appears to be an appropriately efficient tool
for estimating the relative sustainability. Moreover, our results in the Karoun system indicate that significant changes in
sustainability values are possible through dedicating money for treatment and strict pollution controls while simultaneously
requiring a technical advance along change in current attitudes for environment protection. 相似文献
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Water is scarce in many regions of the world, clean water is difficult to find in most developing countries, there are conflicts
between irrigation needs and urban demands, and there is wide debate over appropriate means of resolving these problems. Similarly,
in China, there is limited understanding of the ways in which people, groups, and institutions contribute to, are affected
by, and respond to changes in water quantity and quality. We use the example of the Yellow River basin to argue that these
social, managerial, and policy dimensions of the present water problems are significant and overshadow the physical ones.
Despite this, they receive relatively little attention in the research agenda, particularly of the lead agencies in the management
of the Yellow River basin. To this end, we ask ten research questions needed to address the policy needs of water management
in the basin, split into two groups of five. The first five relate to the importance of water in this basin and the changes
that have affected water problems and will continue to do so. The second five questions represent an attempt to explore possible
solutions to these problems. 相似文献
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基于模糊综合评价法与单因子指数评价法的水质评价 总被引:6,自引:0,他引:6
通过2012年5月至10月对凡河榛子岭水库上游河段的水质监测,采用模糊综合评价法对凡河榛子岭水库上游河段水体的水质状况进行了综合评价,同时与单因子指数评价法评价结果进行对比分析。结果表明,2种评价方法的评价结果存在较大差异,采用模糊综合评价法评价得到的水质评价结果相对较好;采用模糊综合评价法评价,仅6月的杨坟沟、岱海寨断面及9月的杨坟沟断面的水质为Ⅴ类,其他月份各监测断面的水质均符合Ⅲ类水质标准要求;而采用单因子指数评价法的评价结果仅9月份的杨坟沟断面的水质达到Ⅱ类水质,其余各月三个断面监测的水质均超出Ⅴ类水质标准。在水质评价中,应根据评价目的合理选择水质评价方法,使水质评价结果更为准确。 相似文献
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青竹江水环境耗氧污染物含量分布特征及质量评价 总被引:1,自引:0,他引:1
本文对青竹江水环境中耗氧污染物(CODCr、BOD5和NH3-N)含量分布特征进行了探讨,并对青竹江的水质质量进行评价。结果表明,青竹江从上游到下游水体中污染物含量为增加趋势,在时间上也存在一定的变化,枯水期水体中污染物含量高于平水期和丰水期,目前青竹江综合水质可满足Ⅱ类水质标准要求。 相似文献
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The European Water framework directive (WFD) is probably the most important environmental management directive that has been enacted over the last decade in the European Union. The directive aims at achieving an overall good ecological status in all European water bodies. In this article, we discuss the implementation steps of the WFD and their implications for environmental engineering practice while focusing on rivers as the main receiving waters. Arising challenges for engineers and scientists are seen in the quantitative assessment of water quality, where standardized systems are needed to estimate the biological status. This is equally of concern in engineering planning, where the prediction of ecological impacts is required. Studies dealing with both classification and prediction of the ecological water quality are reviewed. Further, the combined emission–water quality approach is discussed. Common understanding of this combined approach is to apply the most stringent of either water quality or emission standard to a certain case. In contrast, for example, the Austrian water act enables the application of only the water quality based approach - at least on a temporary basis. 相似文献
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MFAM模型在河流水质污染模拟及预测中的应用 总被引:2,自引:0,他引:2
文中以时间序列分析为基础,介绍了均值生成函数这一崭新概念,并且经成份因子提取分析推导建立了模拟序列的数字模型(简记为MFAM),经对黄河下游花园口断面的1988-1989年实测水质污染指标溶解氧(DO),氨氧,化学耗氧量(COD),五日生化需氧量(BOD5)等序列模拟,结果表明MFAM模型能较好地模拟河流水质污染指标的变化趋势,拟合平均误差只有5.2-6.4%,MFAM模型应用于预测1990-1991年水质污染指标变化,结果表明预测精度达85%以上,文中最后得出结论:MFAM模型应用于河流污染模拟和预测,是完全可行且十分方便。 相似文献
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河道治理工程重在改善河道的水质,以恢复河流生态系统。本文以北京市大兴区天堂河河道治理工程为例,介绍了河道治理工程环境影响评价中的水质改善预测分析,首先分析生态需水量和供氧量是否满足河流生态需水要求,后又利用地面水环评助手软件预测了河流水质,预测分析了天堂河水质目标的可达性,旨在为以后的河道治理类工程环境影响评价提供参考。 相似文献
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Cochran, Bobby and Charles Logue, 2011. A Watershed Approach to Improve Water Quality: Case Study of Clean Water Services’ Tualatin River Program. Journal of the American Water Resources Association (JAWRA) 47(1):29‐38. DOI: 10.1111/j.1752‐1688.2010.00491.x Abstract: Over the last five years, Clean Water Services developed and implemented a program to offset thermal load discharged from its wastewater facilities to the Tualatin River by planting trees to shade streams and augmenting summertime instream flows. The program has overcome challenges facing many of the nation’s water quality trading programs to not only gain consensus on the frameworks needed to authorize trading, but also provide a broad range of ecosystem services. This paper compares the Tualatin case study with some of the commonly cited factors of successful trading programs. 相似文献
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黄山市新安江流域水环境质量评价与管理措施 总被引:1,自引:0,他引:1
新安江是我国江南跨省级行政区的一条重要河流,其水质和水量对下游浙江省的生态安全和资源支持具有重要作用。针对安徽省黄山市境内新安江流域内存在的主要水环境问题,采用尼梅罗水质指数和超标加权法对新安江流域水环境质量进行了评价和分析。结果表明,新安江流域水环境质量整体较好,达到Ⅱ、Ⅲ类标准,大部分河段均能满足地表水环境功能要求;下游河段水质略差,但符合地表水Ⅲ类标准。在此基础上,提出了新安江流域水环境管理措施。 相似文献