WorldWideScience

Sample records for nonpoint source controls

  1. ECONOMIC APPROACH FOR CONTROL AGRICULTURAL NONPOINT SOURCE POLLUTION IN CHINA

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-yan; CAO Li-ping

    2005-01-01

    This paper mainly discusses the feasibility to establish economic policy systems for control and management of agricultural nonpoint source pollution in China. The current situation of serious agricultural nonpoint source pollution in China is described firstly. Based on the environmental policy and economics theories, the system of economic policies for control and management of agricultural nonpoint source pollution is designed in this paper. This system includes the policy objective, the designing principle and the methods. The key issues include pollution charge,inputs tax for restriction, subsides for induction and incentive, effluent trading for least cost reduction. The emphases are optimized on inputs tax and agricultural chemical tax permit under complete information, as well as sub-optimized inputs tax under incomplete information, subsides for farm due to positive and negative externality. The functions and suitability of the policies are also analyzed in the paper. According to the field experiment results and other relating economic data in watershed of the Chaohe River, Beijing, some economic approaches to reducing agricultural nonpoint source pollution are proposed. The main idea is to encourage and support the farmers to improve their farming way,and to implement the policy of castigating charge simultaneously. The feasibility of the policies are analyzed with consideration of economy, technology and institution. It is concluded that the economic policies are necessary and feasible.

  2. The Roles of Countrywomen in Controlling Non-point Source Pollution

    Institute of Scientific and Technical Information of China (English)

    Jiang Dongmei; Zhou Yuanfang; Lu Genfa

    2006-01-01

    The main causes of non-point source pollution in Taihu Lake are the improper ways of crop production, animal husbandry, and daily runoff. The paper discusses the relationship between countrywomen and non-point source pollution control by 731 questionnaires in Weidu village and 466 questionnaires in Dapu Town. The roles of countrywomen have changed in families and they have close relationship with non-point source pollution. Furthermore, we discuss the possibility and methods of organizing countrywomen in non-point source pollution control.

  3. [A landscape ecological approach for urban non-point source pollution control].

    Science.gov (United States)

    Guo, Qinghai; Ma, Keming; Zhao, Jingzhu; Yang, Liu; Yin, Chengqing

    2005-05-01

    Urban non-point source pollution is a new problem appeared with the speeding development of urbanization. The particularity of urban land use and the increase of impervious surface area make urban non-point source pollution differ from agricultural non-point source pollution, and more difficult to control. Best Management Practices (BMPs) are the effective practices commonly applied in controlling urban non-point source pollution, mainly adopting local repairing practices to control the pollutants in surface runoff. Because of the close relationship between urban land use patterns and non-point source pollution, it would be rational to combine the landscape ecological planning with local BMPs to control the urban non-point source pollution, which needs, firstly, analyzing and evaluating the influence of landscape structure on water-bodies, pollution sources and pollutant removal processes to define the relationships between landscape spatial pattern and non-point source pollution and to decide the key polluted fields, and secondly, adjusting inherent landscape structures or/and joining new landscape factors to form new landscape pattern, and combining landscape planning and management through applying BMPs into planning to improve urban landscape heterogeneity and to control urban non-point source pollution.

  4. Emerging policies to control nonpoint source pollution of groundwater

    Science.gov (United States)

    Harter, T.

    2014-12-01

    Water quality impairment is among the highest ranking public issues of concern in the developed world. While, in Europe and North America, many water quality programs have been put in place over the past half century, regulators difficulties tackling the geographically most widespread water quality degradation in these regions: pollution of groundwater (as opposed to surface water) from diffuse sources (as opposed to point sources), including contamination with nitrate (affecting drinking water supplies in rural areas and at the rural-urban interface) and salinity (affecting irrigation water quality). Other diffuse pollution contaminants include pesticides and emerging contaminants (e.g., antibiotics and pathogens from animal farming). The geographic and hydrologic characteristics of nonpoint source pollution of groundwater are distinctly different from other types of water pollution: individually liable sources are contiguous across the landscape, and internally heterogeneous in space and time. On annually aggregated time scales (most relevant to groundwater), sources are continuously emitting pollution, while pollution levels typically do not exceed MCLs by less than a factor 2. An analysis of key elements of existing water pollution policies to control groundwater pollution from diffuse sources demonstrates the lack of both, science and institutional capacity, while existing point-source approaches cannot be applied toward the control of diffuse pollution to groundwater. For the latter, a key to a successful policy is a tiered, three-way monitoring program based on proxy compliance metrics instead of direct measurement of pollutant discharge, research linking actual pollutant discharges to proxy metrics, and long-term regional groundwater monitoring to establish large scale, long-term trends. Several examples of emerging regulations from California and the EU are given to demonstrate these principles.

  5. Game Analysis and Strategy Research of Farmers Involving in the Agricultural Non-Point Source Pollution Prevention and Control

    OpenAIRE

    Zhou Zaohong

    2013-01-01

    This thesis applies game theory to make a quantitative analysis of the outward problem of the agricultural non-point source pollution and discusses the basic starting point to study the agricultural non-point source pollution prevention and control and furthermore researches the measures and recommendations of agricultural non-point source pollution prevention and control.

  6. Game Analysis and Strategy Research of Farmers Involving in the Agricultural Non-Point Source Pollution Prevention and Control

    Directory of Open Access Journals (Sweden)

    Zhou Zaohong

    2013-06-01

    Full Text Available This thesis applies game theory to make a quantitative analysis of the outward problem of the agricultural non-point source pollution and discusses the basic starting point to study the agricultural non-point source pollution prevention and control and furthermore researches the measures and recommendations of agricultural non-point source pollution prevention and control.

  7. Controlling Non-Point Source Pollution in Australian Agricultural Systems

    Institute of Scientific and Technical Information of China (English)

    C. GOURLEY; A. RIDLEY

    2005-01-01

    The Australian farming sector is continuing to intensify, particularly within 300 km of the east and southern coastlines.In the future there will be fewer and larger farms, which will use more fertilizer, support more stock, grow more monoculture crops, and utilise more marginal soils. This is likely to increase the major environmental impacts of soil degradation, salt,nutrient and sediment contamination of waterways, and greenhouse gas emissions. Australian national water policy continues to focus on land, stream and groundwater salinity issues, although there is now a greater recognition of the importance of nitrogen and phosphorus losses from agriculture. The general philosophy of policy for dealing with nonpoint source pollution has been towards a voluntary rather than regulatory approach, with state and national governments supporting a range of programs to encourage sustainable agricultural practices. A catchment (watershed) based approach,through the use of integrated catchment management plans, is the primary way that non-point source pollution is addressed at the farm and local level. At an industry level, cotton, grains, meat, sugarcane and dairy amongst others, as well as the Australian fertilizer industry, have responded to non-point source issues by investing in research and development, and developing codes of practice aimed at abating these environmental impacts. Understanding the economic, social, political and cultural contexts of farming as well as the environmental impacts of agriculture are very important in determining the appropriateness of policy responses for Australian farming systems.

  8. Techniques for Tracking, Evaluating, and Reporting the Implementation of Nonpoint Source Control Measures - Forestry

    Science.gov (United States)

    This guidance is intended to assist state, regional, and local environmental professionals in tracking the implementation of best management practices (BMPs) used to control nonpoint source pollution generated by forestry practices.

  9. Nonpoint Source: Agriculture

    Science.gov (United States)

    Agricultural runoff as a nonpoint source category of pollution. Resouces to learn more a bout conservation practices to reduce water quality impacts from storm water run off and ground water infiltration

  10. Nonpoint Source Pollution.

    Science.gov (United States)

    Mccoy, Nicholas; Chao, Bing; Gang, Daniel Dianchen

    2015-10-01

    The article presents a comprehensive review of research advancing in 2014 on nonpoint source pollution (NPS). The topics presented relate to nonpoint source pollution (NPS) within agricultural and urban areas. NPS pollution from agricultural areas is the main focus in this review. Management of NPS in agricultural, urban and rural areas is presented. Modeling of NPS pollution in different watersheds with various modeling tools is reviewed.

  11. Optimization strategy integrity for watershed agricultural non-point source pollution control based on Monte Carlo simulation

    Science.gov (United States)

    Gong, Y.; Yu, Y. J.; Zhang, W. Y.

    2016-08-01

    This study has established a set of methodological systems by simulating loads and analyzing optimization strategy integrity for the optimization of watershed non-point source pollution control. First, the source of watershed agricultural non-point source pollution is divided into four aspects, including agricultural land, natural land, livestock breeding, and rural residential land. Secondly, different pollution control measures at the source, midway and ending stages are chosen. Thirdly, the optimization effect of pollution load control in three stages are simulated, based on the Monte Carlo simulation. The method described above is applied to the Ashi River watershed in Heilongjiang Province of China. Case study results indicate that the combined three types of control measures can be implemented only if the government promotes the optimized plan and gradually improves implementation efficiency. This method for the optimization strategy integrity for watershed non-point source pollution control has significant reference value.

  12. Nonpoint Source Pollution Control Projects Grants (Section 319) - 2008 active projects

    Data.gov (United States)

    U.S. Environmental Protection Agency — The California Nonpoint Source (NPS) Program allocates about $4.5 million of CWA Section 319 funding from the U.S. Environmental Protection Agency annually to...

  13. Integrating water quality modeling with ecological risk assessment for nonpoint source pollution control: A conceptual framework

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.D.; McCutcheon, S.C.; Rasmussen, T.C.; Nutter, W.L.; Carsel, R.F.

    1993-01-01

    The historical development of water quality protection goals and strategies in the United States is reviewed. The review leads to the identification and discussion of three components (i.e., management mechanism, environmental investigation approaches, and environmental assessment and criteria) for establishing a management framework for nonpoint source pollution control. Water quality modeling and ecological risk assessment are the two most important and promising approaches to the operation of the proposed management framework. A conceptual framework that shows the general integrative relationships between water quality modeling and ecological risk assessment is presented. (Copyright (c) 1993 IAWQ.)

  14. Uncertainty Analysis of non-point source pollution control facilities design techniques in Korea

    Science.gov (United States)

    Lee, J.; Okjeong, L.; Gyeong, C. B.; Park, M. W.; Kim, S.

    2015-12-01

    The design of non-point sources control facilities in Korea is divided largely by the stormwater capture ratio, the stormwater load capture ratio, and the pollutant reduction efficiency of the facility. The stormwater capture ratio is given by a design formula as a function of the water quality treatment capacity, the greater the capacity, the more the amount of stormwater intercepted by the facility. The stormwater load capture ratio is defined as the ratio of the load entering the facility of the total pollutant load generated in the target catchment, and is given as a design formula represented by a function of the stormwater capture ratio. In order to estimate the stormwater capture ratio and load capture ratio, a lot of quantitative analysis of hydrologic processes acted in pollutant emission is required, but these formulas have been applied without any verification. Since systematic monitoring programs were insufficient, verification of these formulas was fundamentally impossible. However, recently the Korean ministry of Environment has conducted an long-term systematic monitoring project, and thus the verification of the formulas became possible. In this presentation, the stormwater capture ratio and load capture ratio are re-estimated using actual TP data obtained from long-term monitoring program at Noksan industrial complex located in Busan, Korea. Through the re-estimated process, the uncertainty included in the design process that has been applied until now will be shown in a quantitative extent. In addition, each uncertainty included in the stormwater capture ratio estimation and in the stormwater load capture ratio estimation will be expressed to quantify the relative impact on the overall non-point pollutant control facilities design process. Finally, the SWMM-Matlab interlocking module for model parameters estimation will be introduced. Acknowledgement This subject is supported by Korea Ministry of Environment as "The Eco Innovation Project : Non-point

  15. Nanomaterials for environmental burden reduction, waste treatment, and nonpoint source pollution control: a review

    Institute of Scientific and Technical Information of China (English)

    Guobin SHAN; Rao Y. SURAMPALLI; Rajeshwar D. TYAGI; Tian C. ZHANG

    2009-01-01

    Nanomaterials are applicable in the areas of reduction of environmental burden, reduction/treatment of industrial and agricultural wastes, and nonpoint source (NPS) pollution control. First, environmental burden reduction involves green process and engineering, emis-sions control, desulfurization/denitrification of nonrenew-able energy sources, and improvement of agriculture and food systems. Second, reduction/treatment of industrial and agricultural wastes involves converting wastes into products, groundwater remediation, adsorption, delaying photocatalysis, and nanomembranes. Third, NPS pollution control involves controlling water pollution. Nanomater-ials alter physical properties on a nanoscale due to their high specific surface area to volume ratio. They are used as catalysts, adsorbents, membranes, and additives to increase activity and capability due to their high specific surface areas and nano-sized effects. Thus, nanomaterials are more effective at treating environmental wastes because they reduce the amount of material needed.

  16. [Zoning planning in non-point source pollution control in Hanyang district].

    Science.gov (United States)

    Yang, Liu; Ma, Ke-Ming; Guo, Qing-Hai; Zhao, Jing-Zhu; Luo, Yong-Feng

    2006-01-01

    It is most important for managing urban non-point source (NPS) pollution, actualizing the urban sustainable development as well, that zoning planning of urban NPS pollution control is studied. A case study on principles and methods of zoning planning in urban NPS pollution is carried out. Principles of urban sustainable development, priority of urban NPS pollution sensitivity, similarity of urban NPS control direction and region conjugate are put forward. Besides, it is for the first time that a more quantitive method is presented, in the case of Hanyang district, Wuhan city, which is based on L-THIA model and spatial analysis technique in GIS. Assessment of NPS pollution status quo, as well as analysis of NPS sensitivity, is the kernel component of the quantitive method. Hanyang might be divided into four NPS pollution control zones. It is helpful for decision-making of regional NPS pollution control.

  17. Mitigation of nonpoint source pollution in rural areas: From control to synergies of multi ecosystem services.

    Science.gov (United States)

    Wu, Yonghong; Liu, Junzhuo; Shen, Renfang; Fu, Bojie

    2017-12-31

    Nonpoint source (NPS) pollution produced by human activities in rural areas has induced excessive nutrient input into surface waters and the decline of water quality. The essence of NPS pollution is the transport of nutrients between soil and water. Traditional NPS pollution control strategies, however, are mainly based on the solid and liquid phases, with little focus on the bio-phase between water and soil. The pollutants produced from NPS can be regarded as a resource if recycled or reused in an appropriate way in the agricultural ecosystem. This mini review proposes novel strategies for NPS pollution control based on three phases (liquid, solid and bio-phase) and highlights the regulating services of an agricultural ecosystem by optimizing land use/cover types. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. [L-THIA-based management design for controlling urban non-point source pollution].

    Science.gov (United States)

    Guo, Qing-Hai; Yang, Liu; Ke-Ming, Ma

    2007-11-01

    L-THIA Model was used to simulate the amounts of NPS pollutants in 2 catchments of Sanjiao watershed (Sj1, Sj2) in Hanyang district, and the total simulated amount of NPS loads in Sj1 and Sj2 were 1.82 x 10(4) kg, 1.38 x 10(5) kg, respectively. Based on the theory of resource-sink" and interaction of pattern with process, a series of BMPs, including green roof, grassland, porous pavement, infiltration trench, vegetative filter strip and wet pond, were optimized, and effects of BMPs were simulated along the surface runoff pathway. The results show that total pollutants outputs entering Sj1 and Sj2 account for 14.65% and 6.57%, respectively. Combining L-THIA model and BMPs in series is a proper measure for non-point source pollution control and urban development planning at watershed or region scale.

  19. Study on Management and Control of Nonpoint Source Pollution from Urban Surface Runoff

    Institute of Scientific and Technical Information of China (English)

    Chen Keliang; Zhu Xiaodong; Wang Xianghua; Ma Yan

    2007-01-01

    Urbanization is the dominant form of land-use change in terms of impacts on water quality, hydrology, physical properties of watersheds and their nonpoint source (NPS) pollution potential at present. Urbanization has changed the source, process and sink of urban NPS pollution, especially raised the pollution load of urban runoff NPS in receiving water. Urban runoff pollution is a hot spot of research on NPS. This paper analyzed type,source and harm of the NPS pollutants of urban runoff and its influence on the receiving water. Through estimating NPS pollution load of urban runoff and summarizing the law and characteristics of urban runoff NPS systemically, study on management and control of urban runoff NPS pollution was focused on the application of BMPs (best management practices). It is a fresh methodology that management and control on NPS pollution from urban surface runoff was analyzed by methods of landscape ecology,environmental economics and environmental management. The paper provided a scientific reference for mitigating urban water environment pressure and an effective method for management and control of NPS pollution from urban surface runoff..

  20. [Spatial discharge characteristics and total load control of non-point source pollutants based on the catchment scale].

    Science.gov (United States)

    Wang, Xia-Hui; Lu, Jun; Zhang, Qing-Zhong; Wang, Bo; Yao, Rui-Hua; Zhang, Hui-Yuan; Huang, Feng

    2011-09-01

    Agricultural non-point source pollution is one of the major causes of water quality deterioration. Based on the analysis of the spatial discharge characteristics and intensity of major pollutants from the agricultural pollution source, the establishment of spatial management subzones for controlling agricultural non-point pollution and a design of a plan for total load control of pollutants from each subzone is an important way to improve the efficiency of control measures. In this paper the Four Lake basin in Hubei Province is adopted as the research case region and a systematic research of the control countermeasures of agricultural non-point pollution based on the catchment scale is carried out. The results shows that in the Four Lake basin, the COD, total nitrogen, total phosphorus and ammonia nitrogen load of the water environment are mainly caused by agricultural non-point pollution. These four kinds of non-point source pollutants respectively account for 67.6%, 82.2%, 84.7% and 50.9% of the total pollutant discharge amount in the basin. The analysis of the spatial discharge characteristics of non-point source pollutants in the Four Lake basin shows that the major contributor source regions of non-point source pollutant in the basin are the four counties, including Honghu, Jianli, Qianjiang and Shayang where the aquatic and livestock production are relatively developed. According to the spatial discharge characteristics of the pollutants and the evaluation of the discharge intensity of pollutants, the Four Lake basin is divided into three agricultural non-point pollution management subzones, which including Changhu upstream aquatic and livestock production pollution control subzone, Four-lake trunk canal rural non-point source pollution control subzone and Honghu aquatic production pollution control subzone. Specific pollution control measures are put forward for each subzone. With a comprehensive consideration of the water quality amelioration and the

  1. Study on the Control Model of Rural Non-point Source Pollution——Taking Ninghe County in Tianjin as an Example

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the control model of rural non-point source pollution.[Method] Taking Ninghe County(a typical agricultural county in Tianjin) as an example,the current development of local economy and society and characteristics of rural non-point source pollution were studied firstly,then the control model of rural non-point source pollution suitable for Ninghe County was constructed,and its environmental and economic benefits were analyzed finally.[Result] According to the sources of non-...

  2. Denitrification controls in urban riparian soils: implications for reducing urban nonpoint source nitrogen pollution.

    Science.gov (United States)

    Li, Yangjie; Chen, Zhenlou; Lou, Huanjie; Wang, Dongqi; Deng, Huanguang; Wang, Chu

    2014-09-01

    The purpose of this research was to thoroughly analyze the influences of environmental factors on denitrification processes in urban riparian soils. Besides, the study was also carried out to identify whether the denitrification processes in urban riparian soils could control nonpoint source nitrogen pollution in urban areas. The denitrification rates (DR) over 1 year were measured using an acetylene inhibition technique during the incubation of intact soil cores from six urban riparian sites, which could be divided into three types according to their vegetation. The soil samples were analyzed to determine the soil organic carbon (SOC), soil total nitrogen (STN), C/N ratio, extractable NO3 (-)-N and NH4 (+)-N, pH value, soil water content (SWC), and the soil nitrification potential to evaluate which of these factors determined the final outcome of denitrification. A nitrate amendment experiment further indicated that the riparian DR was responsive to added nitrate. Although the DRs were very low (0.099 ~ 33.23 ng N2O-N g(-1) h(-1)) due to the small amount of nitrogen moving into the urban riparian zone, the spatial and temporal patterns of denitrification differed significantly. The extractable NO3 (-)-N proved to be the dominant factor influencing the spatial distribution of denitrification, whereas the soil temperature was a determinant of the seasonal DR variation. The six riparian sites could also be divided into two types (a nitrate-abundant and a nitrate-stressed riparian system) according to the soil NO3 (-)-N concentration. The DR in nitrate-abundant riparian systems was significantly higher than that in the nitrate-stressed riparian systems. The DR in riparian zones that were covered with bushes and had adjacent cropland was higher than in grass-covered riparian sites. Furthermore, the riparian DR decreased with soil depth, which was mainly attributed to the concentrated nitrate in surface soils. The DR was not associated with the SOC, STN, C/N ratio, and

  3. Application of a constructed wetland for non-point source pollution control.

    Science.gov (United States)

    Kao, C M; Wang, J Y; Lee, H Y; Wen, C K

    2001-01-01

    In Taiwan, non-point source (NPS) pollution is one of the major causes of impairment of surface waters. The main objective of this study was to evaluate the efficacy of using constructed wetlands on NPS pollutant removal and water quality improvements. A field-scale constructed wetland system was built inside the campus of National Sun Yat-Sen University (located in southern Taiwan) to remove (1) NPS pollutants due to the stormwater runoff, and (2) part of the untreated wastewater from school drains. The constructed wetland was 40 m (L) x 30 m (W) x 1 m (D), which received approximately 85 m3 per day of untreated wastewater from school drainage pipes. The plants grown on the wetland included floating (Pistia stratiotes L.) and emergent (Phragmites communis L.) species. One major storm event and baseline water quality samples were analyzed during the monitoring period. Analytical results indicate that the constructed wetland removed a significant amount of NPS pollutants and wastewater constituents. More than 88% of nitrogen, 81% of chemical oxygen demand (COD), 85% of heavy metals, and 60% of the total suspended solids (TSS) caused by the storm runoff were removed by the wetland system before discharging. Results from this study may be applied to the design of constructed wetlands for NPS pollution control and water quality improvement.

  4. [Review of urban nonpoint source pollution models].

    Science.gov (United States)

    Wang, Long; Huang, Yue-Fei; Wang, Guang-Qian

    2010-10-01

    The development history of urban nonpoint source pollution models is reviewed. Features, applicability and limitations of seven popular urban nonpoint source pollution models (SWMM, STORM, SLAMM, HSPF, DR3M-QUAL, MOUSE, and HydroWorks) are discussed. The methodology and research findings of uncertainty in urban nonpoint source pollution modeling are presented. Analytical probabilistic models for estimation of urban nonpoint sources are also presented. The research achievements of urban nonpoint source pollution models in China are summarized. The shortcomings and gaps of approaches on urban nonpoint source pollution models are pointed out. Improvements in modeling of pollutants buildup and washoff, sediments and pollutants transport, and pollutants biochemical reactions are desired for those seven popular models. Most of the models developed by researchers in China are empirical models, so that they can only applied for specific small areas and have inadequate accuracy. Future approaches include improving capability in fate and transport simulation of sediments and pollutants, exploring methodologies of modeling urban nonpoint source pollution in regions with little data or incomplete information, developing stochastic models for urban nonpoint source pollution simulation, and applying GIS to facilitate urban nonpoint source pollution simulation.

  5. Role of rural solid waste management in non-point source pollution control of Dianchi Lake catchments, China

    Institute of Scientific and Technical Information of China (English)

    Wenjing LU; Hongtao WANG

    2008-01-01

    In recent years, with control of the main municipal and industrial point pollution sources and implementation of cleaning for some inner pollution sources in the water body, the discharge of point source pollution decreased gradually, while non-point source pollution has become increasingly distressing in Dianchi Lake catchments. As one of the major targets in non-point source pollution control, an integrated solid waste controlling strategy combined with a technological solution and management system was proposed and implemented based on the waste disposal situation and characteristics of rural solid waste in the demonstration area. As the key technoogy in rural solid waste treatment, both centralized plantscale composting and a dispersed farmer-operated waste treating system showed promise in rendering timely benefits in efficiency, large handling capacity, high quality of the end product, as well as good economic return. Problems encountered during multi-substrates co-com-posting such as pathogens, high moisture content, asyn-chronism in the decomposition of different substrates, and low quality of the end product can all be tackled. 92.5% of solid waste was collected in the demonstration area, while the treating and recycling ratio reached 87.9%, which pre-vented 32.2 t nitrogen and 3.9 t phosphorus per year from entering the water body of Dianchi Lake after imple-mentation of the project.

  6. Impacts of DEM uncertainties on critical source areas identification for non-point source pollution control based on SWAT model

    Science.gov (United States)

    Xu, Fei; Dong, Guangxia; Wang, Qingrui; Liu, Lumeng; Yu, Wenwen; Men, Cong; Liu, Ruimin

    2016-09-01

    The impacts of different digital elevation model (DEM) resolutions, sources and resampling techniques on nutrient simulations using the Soil and Water Assessment Tool (SWAT) model have not been well studied. The objective of this study was to evaluate the sensitivities of DEM resolutions (from 30 m to 1000 m), sources (ASTER GDEM2, SRTM and Topo-DEM) and resampling techniques (nearest neighbor, bilinear interpolation, cubic convolution and majority) to identification of non-point source (NPS) critical source area (CSA) based on nutrient loads using the SWAT model. The Xiangxi River, one of the main tributaries of Three Gorges Reservoir in China, was selected as the study area. The following findings were obtained: (1) Elevation and slope extracted from the DEMs were more sensitive to DEM resolution changes. Compared with the results of the 30 m DEM, 1000 m DEM underestimated the elevation and slope by 104 m and 41.57°, respectively; (2) The numbers of subwatersheds and hydrologic response units (HRUs) were considerably influenced by DEM resolutions, but the total nitrogen (TN) and total phosphorus (TP) loads of each subwatershed showed higher correlations with different DEM sources; (3) DEM resolutions and sources had larger effects on CSAs identifications, while TN and TP CSAs showed different response to DEM uncertainties. TN CSAs were more sensitive to resolution changes, exhibiting six distribution patterns at all DEM resolutions. TP CSAs were sensitive to source and resampling technique changes, exhibiting three distribution patterns for DEM sources and two distribution patterns for DEM resampling techniques. DEM resolutions and sources are the two most sensitive SWAT model DEM parameters that must be considered when nutrient CSAs are identified.

  7. Study on Control Countermeasures of Agricultural Non-point Source Pollution in Lakeside Belt of Poyang Lake——Taking Duchang Section in the Lower Reaches of Poyang Lake as Example

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the control countermeasures of agricultural non-point source pollution in lakeside belt of Poyang Lake.[Method] The current situation of water quality of Poyang Lake was analyzed firstly,then the causes of agricultural non-point source pollution in Duchang section of Poyang Lake were studied,finally corresponding control countermeasures were put forward.[Result] Agricultural non-point source pollution in Duchang section of Poyang Lake was mainly related to the rapid developm...

  8. Nationwide assessment of nonpoint source threats to water quality

    Science.gov (United States)

    Thomas C. Brown; Pamela Froemke

    2012-01-01

    Water quality is a continuing national concern, in part because the containment of pollution from nonpoint (diffuse) sources remains a challenge. We examine the spatial distribution of nonpoint-source threats to water quality. On the basis of comprehensive data sets for a series of watershed stressors, the relative risk of water-quality impairment was estimated for the...

  9. 植草沟技术在面源污染控制中的研究进展%Advance on Grassed Swales Technology in Non-point Source Pollution Control

    Institute of Scientific and Technical Information of China (English)

    王健; 尹炜; 叶闽; 雷阿林; 李思敏

    2011-01-01

    Current research advances of non-point source pollution, especially urban non-point source pollution were introduced. Research advances and applications of grassed swales technology in non-point source pollution control were expounded. Main problems and application prospects of grassed swales technology in actual engineering were discussed as well. Coupling of grassed swales technology and other non-point source pollution control technology are proposed to be considered as a development direction in urban non-point source pollution control.%文章介绍了面源污染,尤其是城市面源污染的现状及其控制技术研究进展,并论述了植草沟技术的国内外研究进展及应用现状,讨论了其在工程中需解决的问题及应用前景,提出了植草沟技术与其他面源污染控制单项技术有机耦合是城市面源污染控制的一个发展方向.

  10. Comparative Assessment of Stormwater and Nonpoint Source Pollution Best Management Practices in Suburban Watershed Management

    OpenAIRE

    Qiu, Zeyuan

    2013-01-01

    Nonpoint source pollution control and stormwater management are two objectives in managing mixed land use watersheds like those in New Jersey. Various best management practices (BMPs) have been developed and implemented to achieve both objectives. This study assesses the cost-effectiveness of selected BMPs for agricultural nonpoint source pollution control and stormwater management in the Neshanic River watershed, a typical mixed land use watershed in central New Jersey, USA. The selected BMP...

  11. Assessment of Economic Loss Caused by Agricultural Non-point Source Nutrient Loss

    Institute of Scientific and Technical Information of China (English)

    FAN Liang-qian; CHEN Feng-hui

    2012-01-01

    Taking Zhejiang Province as an example, we use the JOHNES export coefficient model to estimate the total nitrogen (TN) and total phosphorus (TP) load of agricultural planting, livestock and poultry breeding and rural living non-point source in 2009. Based on the protection cost method in environmental economics, we quantitatively assess the economic loss caused by these three types of non-point source nutrient loss. The results show that in TN non-point source load, the load of land for planting accounts for 57.48%, the load of rural living accounts for 30.22%, and the load of livestock and poultry breeding accounts for 12.30%; in TP non-point source load, the load of rural living accounts for 46.18%, the load of livestock and poultry breeding accounts for 29.00%, and the load of land for planting accounts for 24.82%. The economic loss arising from the agricultural non-point source nutrient loss is equivalent to 2.329 424 7 billion yuan per year (the loss from land for planting accounts for 55.46%; the loss from rural living accounts for 31.21%; the loss from livestock and poultry breeding accounts for 13.33%). It indicates that in order to reduce the loss arising from agricultural non-point source nutrient loss, we should pay attention to controlling the land for planting and rural living source.

  12. Reducing non-point source pollution with enhancing infiltration

    Institute of Scientific and Technical Information of China (English)

    MU Huan-zhen; ZHENG Tao; HUANG Yan-chu; ZHANG Chun-ping; LIU Chen

    2006-01-01

    The rainfall system was set up on a slope land, which was used with some materials to enhance soil infiltration. The results showed that it was effective to enhance the infiltration of rainwater in soil and reduce the pollutants of surface runoff. After the soil meliorated by the lignin polymer and zeolite, runoff was delayed about 10 min and reduced by 44.40%-50.00%, synchronously, the pollutant loads, such as total suspended solids (TSS), chemical oxygen demand by ditromate (CODCr), total nitroger (TN) and total phosphorus (TP), were reduced on averages by 44.58%, 37.80%, 51.62% and 44.11%, respectively. It is an available technique to control the pollution of non-point source from sources.

  13. mpacts of Agricultural Non-point Pollution on Water-source Area in Songhua Dam

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    [Objective] The aim was to research impacts of agricultural non-point pol- lution on water-source region in Songhua Dam, laying foundation for control of water pollution and scientific protection of water-source region. [Method] Water in Muyang River, lengshui River and Zizania aquatica region were sampled to measure content of pollutants in water and conclude relation between water contamination and agri- cultural non-point pollution to find the major cause of pollution. [Result] Organic pollu- tant in Muyang River was higher; N and P contents in Lengshui River were higher; the measured indices in Zizania aquatica region excessively exceeded related stan- dard. [Conclusion] The chemical fertilizers and pesticides are the toxic materials lead- ing to water contamination and constitute a major cause of pollution in Songhua Dam water-source region. Agricultural non-point pollution should be controlled in a scientific way.

  14. Contingent Valuation of Residents' Attitudes and Willingness-to-Pay for Non-point Source Pollution Control: A Case Study in AL-Prespa, Southeastern Albania

    Science.gov (United States)

    Grazhdani, Dorina

    2015-07-01

    Recently, local governments in Albania have begun paying attention to management of small watershed, because there are specific boundaries and people living within a watershed basin tend to be more concerned about the basin's environmental, economic, and social development. But this natural resource management and non-point source (NPS) pollution control is still facing challenges. Albanian part of Prespa Park (AL-Prespa) is a good case study, as it is a protected wetland area of high biodiversity and long human history. In this framework, this study was undertaken, the main objectives of which were to explore: (1) the attitudes of the residents toward NPS pollution control, (2) their willingness-to-pay for improving water quality, and (3) factors affecting the residents' willingness-to-pay. Descriptive statistics, one-way ANOVA (analysis of variance), Chi-square analysis, and multivariate data analysis techniques were used. Findings strongly suggested that the residents' attitudes toward NPS pollution control in this area were positive. With the combination of two major contingent valuation methods—dichotomous choice and open-ended formats, the survey results indicated that the average yearly respondents' WTP was €6.4. The survey revealed that residents' yearly income and education level were the main factors affecting residents' willingness-to-pay for NPS pollution control in this area, and there was no significant correlation between residents' yearly income and their education level. The current study would lay a solid foundation on decision-making in further NPS pollution control and public participation through community-based watershed management policies in AL-Prespa watershed and similar areas.

  15. Comparative Assessment of Stormwater and Nonpoint Source Pollution Best Management Practices in Suburban Watershed Management

    Directory of Open Access Journals (Sweden)

    Zeyuan Qiu

    2013-03-01

    Full Text Available Nonpoint source pollution control and stormwater management are two objectives in managing mixed land use watersheds like those in New Jersey. Various best management practices (BMPs have been developed and implemented to achieve both objectives. This study assesses the cost-effectiveness of selected BMPs for agricultural nonpoint source pollution control and stormwater management in the Neshanic River watershed, a typical mixed land use watershed in central New Jersey, USA. The selected BMPs for nonpoint source pollution control include cover crops, prescribed grazing, livestock access control, contour farming, nutrient management, and conservation buffers. The selected BMPs for stormwater management are rain gardens, roadside ditch retrofitting, and detention basin retrofitting. Cost-effectiveness is measured by the reduction in pollutant loads in total suspended solids and total phosphorus relative to the total costs of implementing the selected BMPs. The pollution load reductions for these BMPs are based on the total pollutant loads in the watershed simulated by the Soil and Water Assessment Tool and achievable pollutant reduction rates. The total implementation cost includes BMP installation and maintenance costs. The assessment results indicate that the BMPs for the nonpoint source pollution control are generally much more cost-effective in improving water quality than the BMPs for stormwater management.

  16. 缓冲带在农业面源污染防治上的应用%Study on pollution control of agricultural nonpoint source by means of buffer strips

    Institute of Scientific and Technical Information of China (English)

    杨帆; 刘赢男; 焉志远; 黎叩晨; 倪红伟

    2015-01-01

    Agricultural nonpoint source pollution has become one of the m ost important threats to water environment safety. To ensure security of water environment, it is necessary to prevent and control agricultural non-point source pollution. Riparian buffer zone, which could effectively prevent and control agricultural non-point source pollution, has been widely recognized, and it also has a certain application on the source of water prevention. Based on the introduction of definition of buffer zone, structure of macro and microscopic, mechanism of nitrogen and phosphorus losing and research of different countries and regions of agricultural non-point pollution, the protection of riparian buffer strips in the water environment was proposed.%农业面源污染已经成为威胁水环境安全的一个重要因素,为了保证水质安全,对进入水体的农业面源污染进行防治是十分必要的。缓冲带在防治农业面源污染上的功效已经得到了广泛的认可,并在水污染治理上有一定的应用前景。通过对缓冲带的定义、宏观和微观结构、氮磷元素流失机理以及不同国家和地区应用缓冲带去除农业面源污染方面的研究,提出了我国缓冲带在水环境保护中的应用前景。

  17. 基于农业面源污染控制的三峡库区种植业结构优化%Planting structure optimization based on agricultural non-point source pollution control in Three Gorges Reservoir Region

    Institute of Scientific and Technical Information of China (English)

    肖新成; 谢德体; 何丙辉; 魏朝富; 倪九派

    2014-01-01

    Agricultural non-point source pollution has gradually become a major pollution source of lake eutrophication and deterioration of water quality in recent years. The Three Gorges Reservoir Region is both an important sensitive eco-economy area and a typical poverty-stricken mountain area. However, its unique geographical location, its irrational agricultural structure and its increasing serious agricultural non-point source pollution problems challenge the environment in this region. Hence, it is a necessity to take controlling agricultural non-point source pollution from the source as one of the most effective approaches. In current research, agricultural non-point source pollution control excessively depends on engineering and technology. Anyhow, the roles of agricultural planting structure adjustment and agricultural cleaner production which can reduce non-point source pollution should not be ignored. Promoting the adjustment of planting structure, reducing the use of chemical fertilizers and pesticides, and adopting agricultural cleaner production technologies not only help improve the land production capacity and agricultural products quality, but also effectively reduce the agricultural non-point source pollution. By these important measures for energy saving and emission reduction can be realized in Three Gorges Reservoir Region. Based on the dual goals of the optimal agricultural economic benefits and non-point source pollution emission reduction, the linear programming model was used to optimize the planting structure and clean agricultural production in the Three Gorges Reservoir Region. The optimization results showed that the optimal paths to maximize the crop net income were as follows: The land area for grain production should cover 119.16×104hm2but cleaner production area of rice-wheat, corn, soybean and tuber crops needs 31.91×104, 18.69×104, 6.79×104and 19.55×104 hm2; the land area for vegetables planting should be 33.25×104hm2 and its cleaner

  18. Nonpoint source pollution loading from an undistributed tropic forest area.

    Science.gov (United States)

    Chang, Chih-Hua; Wen, Ching-Gung; Huang, Chia-Hui; Chang, Shui-Ping; Lee, Chih-Sheng

    2008-11-01

    Water quality and unit nonpoint sources (NPS) pollution load from a forest area were studied in a mountainous watershed in Taiwan. The flow rates were measured with rectangular weirs and samples taken for water quality analysis in both non-rainy and rainy days for 2 years. The subroutine of the Hydrological Simulation Program--FORTRAN was used to simulate runoff for additional 3 years. Total annual loads of various water quality parameters were then estimated by a regression model. Most of the parameter concentrations are higher during the rainy days; their values are typically higher as compared to data from other undisturbed forest areas. Nevertheless, the concentration ratio of dissolved inorganic nitrogen to TN or PO4(3-) -P to TP shows TN or TP no correlations with the flow rates, whereas the concentrations of SS and TP are positively correlated with the flow rate. The fluctuation of annual load from this watershed is significant. For example, six major events of the entire year, for which the total duration is merely 6.4 days, contribute 42% of the annual precipitation and at least 40% of the annual NPS loads. The management for controlling the NPS pollution from this forest watershed is discussed.

  19. Nonpoint source water pollution abatement and the feasibility of voluntary programs

    Science.gov (United States)

    Sawicki, David S.; Judd, Lynne B.

    1983-09-01

    This article details a case study of a voluntary, decentralized institutional arrangement for nonpint source water pollution control used in the Root River watershed in southeastern Wisconsin. This watershed was chosen because of its mix of urban, agricultural, and urbanizing land uses. The project objectives were to monitor and draw conclusions about the effectiveness of a voluntary, decentralized institutional system, to specify deficiencies of the approach and suggest means to correct them, and to use the conclusions to speculate about the need for regulations regarding nonpoint source pollution control or the appropriateness of financial incentives for nonpoint source control. Institutional factors considered include diversity of land uses in the watershed, educational needs, economic conditions, personality, water quality, number of agencies involved, definition of authority, and bureaucratic requirements

  20. Discussion on the Green Tax Stimulation Measure of Nitrogen Fertilizer Non-Point Source Pollution Control - Taking the Dongting Lake Area in China as a Case

    Institute of Scientific and Technical Information of China (English)

    XIANG Ping-an; ZHOU Yan; HUANG Huang; ZHENG Hua

    2007-01-01

    A study on designing the tax of nitrogen fertilizer can provide a new method for controlling nitrogen fertilizer non-point source pollution. The tax design of nitrogen fertilizer was discussed by utilizing the external theory and the demand elasticity theory. The results indicated that the coefficient of price elasticity of nitrogen fertilizer demand is -0.21, which instructed that the market demand is in lack of elasticity in the short period and the impact of nitrogen fertilizer manufacturers is subtle. The 11 counties (cities and boroughs) in the Dongting Lake area in China, where the farmland nitrogen application surpassed the average ecological fertilization dosage, is listed to the taxation scope of nitrogen fertilizer tax. The environment loss will reduce 0.07 hundred million RMB yuan and the revenue will increase 0.89 hundred million RMB yuan in the country after levying on nitrogen fertilizer. The loss, which was brought by the decreasing food supplies production, will be 0.58 hundred million RMB yuan and the net social benefit will be 0.38 hundred million RMB yuan following revenue collection. The variation scope of the increasing expenditure of farmers will range from 0.95 to 1.49%. The variation scope of the income of farmers will range from -8.41 to 6.44%. The 5 areas, Yunxi Borough, Junshan Borough, Hanshou County, Jinshi City, and Ziyang Borough, had an increase in food supplies production after the revenue collection. The environment loss will reduce 0.01 hundred million RMB yuan and the revenue will increase 0.16 hundred million RMB yuan in the country after levying on nitrogen fertilizer. The economic benefits, which was brought by the increasing cereals production, will be 0.67 hundred million RMB yuan and the net social benefit will be 0.84 hundred million RMB yuan after revenue collection. The variation scope of the increasing expenditure of farmers will range from 0.95 to 1.06%. The variation scope of the increasing income of farmers will

  1. Agroforestry buffers for nonpoint source pollution reductions from agricultural watersheds.

    Science.gov (United States)

    Udawatta, Ranjith P; Garrett, Harold E; Kallenbach, Robert

    2011-01-01

    Despite increased attention and demand for the adoption of agroforestry practices throughout the world, rigorous long-term scientific studies confirming environmental benefits from the use of agroforestry practices are limited. The objective was to examine nonpoint-source pollution (NPSP) reduction as influenced by agroforestry buffers in watersheds under grazing and row crop management. The grazing study consists of six watersheds in the Central Mississippi Valley wooded slopes and the row crop study site consists of three watersheds in a paired watershed design in Central Claypan areas. Runoff water samples were analyzed for sediment, total nitrogen (TN), and total phosphorus (TP) for the 2004 to 2008 period. Results indicate that agroforestry and grass buffers on grazed and row crop management sites significantly reduce runoff, sediment, TN, and TP losses to streams. Buffers in association with grazing and row crop management reduced runoff by 49 and 19%, respectively, during the study period as compared with respective control treatments. Average sediment loss for grazing and row crop management systems was 13.8 and 17.9 kg ha yr, respectively. On average, grass and agroforestry buffers reduced sediment, TN, and TP losses by 32, 42, and 46% compared with the control treatments. Buffers were more effective in the grazing management practice than row crop management practice. These differences could in part be attributed to the differences in soils, management, and landscape features. Results from this study strongly indicate that agroforestry and grass buffers can be designed to improve water quality while minimizing the amount of land taken out of production.

  2. 基于博弈论的非点源污染控制模型探讨%Modeling Nonpoint Source Pollution Control from the View of Game Theory

    Institute of Scientific and Technical Information of China (English)

    张蔚文; 刘飞; 王新艳

    2011-01-01

    With the increasing ability to deal with point source pollution, such as industrial and urban life sewage, the impact of agricultural non-point source pollution on water quality environment has become more and more apparent. Compared with point source pollution, non-point source pollution occurs at an uncertain time, in an uncertain way and with uncertain quantity, which brings much more difficulties to the making of some relevant control policies. Beginning with the famous phenomenon of the Tragedy of Commons, this paper analyzes the game situation among the non-point pollution makers based on the marketing game model and the government supervision game model, and then proposes a way to manage and control non-point pollution in the form of "collective performance". Premising with the target of decreasing pollutant discharge, marketing game model proves that it is feasible and efficient to do the trade on point-nonpoint source pollution on the basis of the principle of Optimal Cost, while the results of the government supervision game model show that; a reasonable environment subsidy and punishment mechanism, and government's attaching importance to the self-reputation and public image will play a positive role in promoting non-point source pollution control.%随着对工业和城市生活污水等点源污染治理能力的不断增强,农业非点源污染对水质环境的影响日益凸现.相对于点源污染,非点源污染发生的不确定时间、不确定途径、不确定量等特点给治理政策的制定带来很大难度.本文从著名的公地悲剧现象出发,着力从市场博弈及政府监督博弈两个模型分析非点源污染制造者之间的博弈格局,并提出以“集体表现”的形式对非点源污染进行管理和控制.市场博弈模型中以一定的排污削减目标为前提,确定以成本最优的原则进行点源-非点源排污权交易是可行且有效率的;而政府监督博弈模型的结果显示:合理的

  3. Assessment and Strategies for Watershed Agricultural Non-point Source Pollution Control%集水区农业非点源污染之评估及控制对策

    Institute of Scientific and Technical Information of China (English)

    林昭远; 陈键鑫; 颜正平

    2001-01-01

    Improper agricultural activities accelerate soil loss and water pollution. An assessment system for agricultural non-point source pollution estimation was developed in this study. Digital Elevation Model (DEM), Remote Sensing (RS) and Geographic Information Systems (GIS) couples with non-point source pollution models were applied in the system to discuss the efficiency of non-point pollution control in a watershed. Concepts of sediment delivery ratio (SDR) and placement of riparian buffer strips couples with the analysis of topography and hydrology for the watersheds of interest to classify the sensitive zone could effectively monitor and control watershed agricultural non-point-source pollution.%集水区内不当之农业活动,加速集水区土壤流失及水库水质恶化。本研究利用数值地形模型(Digital Elevation Model, DEM)、配合遥感探测 (Remote Sensing, RS)与地理信息系统(Geographic Information Systems, GIS)等技术,撰写程序建立集水区农业非点源污染评估系统,探讨集水区农业非点源污染控制之成效。利用泥砂递移率与植生缓冲带区位检视集水区内之农业非点源污染源,划定集水区环境敏感区位,针对敏感区回收造林,可有效控制集水区农业非点源污染。

  4. Modeling nonpoint source nitrate contamination and associated uncertainty in groundwater of U.S. regional aquifers

    Science.gov (United States)

    Gurdak, J. J.; Lujan, C.

    2009-12-01

    Nonpoint source nitrate contamination in groundwater is spatially variable and can result in elevated nitrate concentrations that threaten drinking-water quality in many aquifers of the United States. Improved modeling approaches are needed to quantify the spatial controls on nonpoint source nitrate contamination and the associated uncertainty of predictive models. As part of the U.S. Geological Survey National Water Quality Assessment Program, logistic regression models were developed to predict nitrate concentrations greater than background in recently recharged (less than 50 years) groundwater in selected regional aquifer systems of the United States; including the Central Valley, California Coastal Basins, Basin and Range, Floridan, Glacial, Coastal Lowlands, Denver Basin, High Plains, North Atlantic Coastal Plain, and Piedmont aquifer systems. The models were used to evaluate the spatial controls of climate, soils, land use, hydrogeology, geochemistry, and water-quality conditions on nitrate contamination. The novel model Raster Error Propagation Tool (REPTool) was used to estimate error propagation and prediction uncertainty in the predictive nitrate models and to determine an approach to reduce uncertainty in future model development. REPTool consists of public-domain, Python-based packages that implement Latin Hypercube sampling within a probabilistic framework to track error propagation in geospatial models and quantitatively estimate the prediction uncertainty of the model output. The presented nitrate models, maps, and uncertainty analysis provide important tools for water-resource managers of regional groundwater systems to identify likely areas and the spatial controls on nonpoint source nitrate contamination in groundwater.

  5. Spatial and Temporal Distribution Characteristics of Agricultural Non-point Source Pollution in Xixi Watershed of Jinjiang Basin

    Institute of Scientific and Technical Information of China (English)

    Kun RONG; Jiqiang ZHANG; Yang SHI

    2016-01-01

    The SWAT model was applied to analyze the temporal-spatial distribution patterns of non-point source pollution loads and the difference of pollution loads of different land use types in Xixi Watershed of Jinjiang Basin. The results showed that both yearly nitrogen and phosphorus pollution loads were evenly distributed during 1973 to 1979,the annual TN pollution from non-point source was 1530 t,or 6. 3 kg / ha,and the annual TP pollution from non-point source was 270 t,or 1. 1 kg / ha during 1973 to 1979 in the watershed. Considerable differences were identified on both monthly nitrogen and phosphorus pollution loads. The TN and TP pollution loads during the flood season( from April to September) accounted for 76. 2% and 75. 8% of the annual load respectively. There were great differences in both TN and TP pollution loads of different land use types in the study area,and the pollution load of both farmland and orchard was higher than that of the other land use types. TN and TP pollution loads of farmland accounted for 66% and 83% of total watershed. There was a great spatial difference in the nonpoint source pollution load of the study area. The critical source areas of non-point source pollution are mainly located at Guanqiao Town,Longmen Town,Changkeng Town,Shangqing Town and Dapu Town,where the efforts of controlling pollution should be made.

  6. Using a constructed wetland for non-point source pollution control and river water quality purification: a case study in Taiwan.

    Science.gov (United States)

    Wu, C Y; Kao, C M; Lin, C E; Chen, C W; Lai, Y C

    2010-01-01

    The Kaoping River Rail Bridge Constructed Wetland, which was commissioned in 2004, is one of the largest constructed wetlands in Taiwan. This multi-function wetland has been designed for the purposes of non-point source (NPS) pollutant removal, wastewater treatment, wildlife habitat, recreation, and education. The major influents of this wetland came from the local drainage trench containing domestic, agricultural, and industrial wastewaters, and effluents from the wastewater treatment plant of a paper mill. Based on the quarterly investigation results from 2007 to 2009, more than 96% of total coliforms (TC), 48% of biochemical oxygen demand (BOD), and 40% of nutrients (e.g. total nitrogen, total phosphorus) were removed via the constructed wetland system. Thus, the wetland system has a significant effect on water quality improvement and is capable of removing most of the pollutants from the local drainage system before they are discharged into the downgradient water body. Other accomplishments of this constructed wetland system include the following: providing more green areas along the riversides, offering more water assessable eco-ponds and eco-gardens for the public, and rehabilitating the natural ecosystem. The Kaoping River Rail Bridge Constructed Wetland has become one of the most successful multi-function constructed wetlands in Taiwan. The experience obtained from this study will be helpful in designing similar natural treatment systems for river water quality improvement and wastewater treatment.

  7. Incorporation of Complex Hydrological and Socio-economic Factors for Non-point Source Pollution Control: A Case Study at the Yincungang Canal, the Lake Tai Basin of China

    Science.gov (United States)

    Yang, X.; Luo, X.; Zheng, Z.

    2012-04-01

    It is increasingly realized that non-point pollution sources contribute significantly to water environment deterioration in China. Compared to developed countries, non-point source pollution in China has the unique characteristics of strong intensity and composition complexity due to its special socioeconomic conditions. First, more than 50% of its 1.3 billion people are rural. Sewage from the majority of the rural households is discharged either without or only with minimal treatment. The large amount of erratic rural sewage discharge is a significant source of water pollution. Second, China is plagued with serious agricultural pollution due to widespread improper application of fertilizers and pesticides. Finally, there lack sufficient disposal and recycling of rural wastes such as livestock manure and crop straws. Pollutant loads from various sources have far exceeded environmental assimilation capacity in many parts of China. The Lake Tai basin is one typical example. Lake Tai is the third largest freshwater lake in China. The basin is located in the highly developed and densely populated Yangtze River Delta. While accounting for 0.4% of its land area and 2.9% of its population, the Lake Tai basin generates more than 14% of China's Gross Domestic Production (GDP), and the basin's GDP per capita is 3.5 times as much as the state average. Lake Tai is vital to the basin's socio-economic development, providing multiple services including water supply for municipal, industrial, and agricultural needs, navigation, flood control, fishery, and tourism. Unfortunately, accompanied with the fast economic development is serious water environment deterioration in the Lake Tai basin. The lake is becoming increasingly eutrophied and has frequently suffered from cyanobacterial blooms in recent decades. Chinese government has made tremendous investment in order to mitigate water pollution conditions in the basin. Nevertheless, the trend of deteriorating water quality has yet to

  8. A method to analyze "source-sink" structure of non-point source pollution based on remote sensing technology.

    Science.gov (United States)

    Jiang, Mengzhen; Chen, Haiying; Chen, Qinghui

    2013-11-01

    With the purpose of providing scientific basis for environmental planning about non-point source pollution prevention and control, and improving the pollution regulating efficiency, this paper established the Grid Landscape Contrast Index based on Location-weighted Landscape Contrast Index according to the "source-sink" theory. The spatial distribution of non-point source pollution caused by Jiulongjiang Estuary could be worked out by utilizing high resolution remote sensing images. The results showed that, the area of "source" of nitrogen and phosphorus in Jiulongjiang Estuary was 534.42 km(2) in 2008, and the "sink" was 172.06 km(2). The "source" of non-point source pollution was distributed mainly over Xiamen island, most of Haicang, east of Jiaomei and river bank of Gangwei and Shima; and the "sink" was distributed over southwest of Xiamen island and west of Shima. Generally speaking, the intensity of "source" gets weaker along with the distance from the seas boundary increase, while "sink" gets stronger.

  9. Zonation for nonpoint source pollution control in Hongfenghu reservoir watershed%红枫湖流域非点源污染控制区划

    Institute of Scientific and Technical Information of China (English)

    耿润哲; 殷培红; 原庆丹

    2016-01-01

    Eutrophication caused by the enrichment of nitrogen and phosphorus is degrading surface water quality throughout the world. Sources of nutrients include over-fertilized agriculture lands, urban areas with excessive usage of herbicides and insecticides, and eroded soils. Due to the variation of nutrient export over the area and time, it is difficult to identify, assess and control nonpoint source (NPS) pollution. The prevention and mitigation of NPS pollution have become priority tasks in water monitoring and restoration programs in many countries. The interaction of human activities with the inherent variations in soil type, climate, topography and hydrology gives rise to large spatial and temporal variation in nutrient concentrations in surface runoff. Many research efforts are made to explore the processes and spatial characteristics of NPS pollution for prevention and mitigation measures. Major pollutants, particularly from agricultural activities, which include nitrogen, phosphorus nutrients and sediment that have been released into aquatic environments, have caused problems in the Hongfenghu Reservoir watershed, Guiyang. It is necessary to identify the spatial and temporal distributions of NPS pollutants and the highly polluted areas for the purpose of watershed management.In this paper, GIS technology, ArcSWAT model, ANOVA (Analysis of Variance) and CA (Cluster analysis) were used to identify the zonation of NPS sources and control in Yangchanghe river watershed which is one of the main tributaries in northwest of Hongfenghu Reservoir watershed, with relative strong intensive agricultural activities. The results showed that the spatial distribution of NPS pollution load in Yangchanghe river watershed was of great heterogeneity, the agricultural land at higher elevation had the highest NPS pollution loads, and the Liu Guang, Huang La, Jiu Zhou and Bai Yun towns were identified as the critical towns for NPS pollution control. In addition, the most important

  10. 重庆市四面山4种森林群落面源污染控制功能分析%The non-point source pollution control function of four forest communities in Simian Mountains, Chongqing

    Institute of Scientific and Technical Information of China (English)

    荣文卓; 张洪江; 杜仕才; 程金花; 王伟; 李根平; 古德洪

    2009-01-01

    Selecting canopy interception rate, capillary porosity,non-capillary porosity and soil anti-erosion coefficient as analysis indices, the function of non-point source pollution control of four forest communities in Simian Mountains of Chongqing were ana-lyzed by Grey Relational Grade Analiysis. The results show that the grey correlation degree of natural Phyllostachys pubescens for-est is 0.887 7, hgher than other three communities, which means that the function of non-point source pollution control of Phyl-lostachys pubescens forest is the best. In the planatations types, the grey correlation degree of broadleaf forest is the highest, 0.779 4, followed by mixed broadleaf-conifer forest (0.699 2). The grey correlation degree of coniferous forest is the lowest, 0.636 1. Which means it has the lowest function for non-point source pollution control.%以重庆市四面山4种森林群落为研究对象,选取林冠截留率、林地土壤毛管孔隙度、林地土壤非毛管孔隙度和林地0~20 cm土壤抗冲刷系数为分析指标,运用灰色关联度法对4种森林群落的面源污染控制功能进行研究.结果表明:在4种森林群落中作为天然林的楠竹林灰关联度值最大为0.887 7,面源污染控制功能最好,其次是人工阔叶林(0.7794)和人工混交林(0.6992),人工针叶林(0.636 1)面源污染防控能力相对较弱.在人工林方面,阔叶林灰关联度值最大为0.7794,面源污染防控能力最好,其次是针阔混交林(0.699 2),针叶林灰关联度值最低为0.636 1,其面源污染防控能力较弱.

  11. 英国农业面源污染防控对我国的启示%Prevention and control of agricultural non-point source pollutions in UK and suggestions to China

    Institute of Scientific and Technical Information of China (English)

    刘坤; 任天志; 吴文良; 孟凡乔; Jessica Bellarby; Laurence Smith

    2016-01-01

    Currently, the world is facing challenges of maintaining food production growth while improving agricultural ecological environ-mental quality. The prevention and control of agricultural non-point source pollution, a key component of these challenges, is a systematic program which integrates many factors such as technology and its extension, relevant regulation and policies. In the project of UK-China Sustainable Agriculture Innovation Network, we undertook a comprehensive analysis of the prevention and control technology, technology extension systems and related policy measures of agricultural non-point source pollution in UK. We then proposed the promotion of preven-tion and control of agricultural non-point source pollution in China. Considering the current agricultural resources and environment counter-measures of“one control”(control over the total quantity of the agricultural water and agricultural water environment pollution),“two re-duction”(reduction in quantities of fertilizers and pesticides), and “three basic countermeasures”(resource utilization, recycling, and disharm treatment of livestock and poultry wastes, agricultural plastic films and crop straws), we suggested that in the near future source control and process prevention should be technical priorities. Optimzation and reduction of chemical fertilizer, combined use of chemical and organic fertilizers, land utilization management, agricultural sector adjustment and integration of crop production with animal husbandry should be the key technologies. The role of non-governmental technical service should be promoted. Government subsidies, ecological com-pensations and other forms of economic means could be used to encourage famers actively participate in the prevention and control of nitro-gen and phosphorus losses and pollution in soil and water systems. Related technical documents and regulations should be more specific, clear, and practical. Collection, transmission and analysis of

  12. A Review of the Research on Eco-Technologies for Control of Urban Nonpoint Source Pollution%城市面源污染生态控制技术研究进展

    Institute of Scientific and Technical Information of China (English)

    王书敏; 于慧; 张彬

    2011-01-01

    快速城市化导致了土地利用类型的迅速变化,由此引起的城市面源污染已成为威胁城市水体健康的主要因素。根据国内外最近几年的研究情况,从净化机理、运行效能、影响因素及评价方法等方面详细介绍了缓冲带、绿色屋顶、植草沟等面源生态控制技术的应用研究情况。各类研究指出,在确保适宜的宽度和坡度、连续植被覆盖的植被缓冲带对消减径流和清除沉积物是极其有效的;绿色屋顶对径流污染消减能力受屋面介质厚度、屋顶坡度、降雨强度、植物类型、土壤层湿度等因素的影响明显;植草沟对于沉积物和重金属去除效率高,而对于易引起水体富营养化的溶解性营养盐的去除效能有待改善,构建介质优化是关键。指出充分发挥各种生态技术的优势、构建城市面源污染生态控制网络是消除城市面源污染毒性、维护健康城市水环境的重要途径。%Land use type has been changed rapidly because of the speeding urbanization,and urban nonpoint source pollution has become the prominent reason of urban waters' deterioration.According to researches in recent years,studies about nonpoint source eco-control technologies such as buffer zones,green roofs and bioswales were introduced in detail in purification mechanism,operating performance,affecting factors,evaluation methods,and other aspects.Buffer zones were very effective in reducing runoff and removing sediment as long as appropriate width and slope,and continuous vegetation covering were ensured.Ability of green roofs in controlling runoff pollution was correlated greatly with medium thickness,roof slope,rainfall intensity,plant type,soil moisture levels and other factors. The efficiencies for removal of TSS and heavy metals by bioswales were very high,however,the ability to control soluble nutrition was still needed to be improved whilst the construction media were the key factor

  13. EPA Office of Water (OW): Nonpoint Source Projects NHDPlus Indexed Dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — GRTS locational data for nonpoint source projects. GRTS locations are coded onto NHDPlus v2.1 flowline features to create point and line events or coded onto NHDPlus...

  14. Evaluation of the Agricultural Non-point Source Pollution in Chongqing Based on PSR Model

    Institute of Scientific and Technical Information of China (English)

    Hanwen; ZHANG; Xinli; MOU; Hui; XIE; Hong; LU; Xingyun; YAN

    2014-01-01

    Through a series of exploration based on PSR framework model,for the purpose of building a suitable Chongqing agricultural nonpoint source pollution evaluation index system model framework,combined with the presence of Chongqing specific agro-environmental issues,we build a agricultural non-point source pollution assessment index system,and then study the agricultural system pressure,agro-environmental status and human response in total 3 major categories,develope an agricultural non-point source pollution evaluation index consisting of 3 criteria indicators and 19 indicators. As can be seen from the analysis,pressures and responses tend to increase and decrease linearly,state and complex have large fluctuations,and their fluctuations are similar mainly due to the elimination of pressures and impact,increasing the impact for agricultural non-point source pollution.

  15. Predicting precipitation on nonpoint source pollutant exports in the source area of the Liao River, China.

    Science.gov (United States)

    Wang, Y; Bian, J M; Wang, S N; Nie, S Y

    The source area of the Liao River is an important grain growing area in China which experiences serious problems with agricultural nonpoint source pollution (NPS) which is impacting the regional economy and society. In order to address the water quality issues it is necessary to understand the spatial distribution of NPS in the Liao River source area. This issue has been investigated by coupling a wavelet artificial neural network (WA-ANN) precipitation model with a soil and water assessment tool (SWAT) model to assess the export of nonpoint source pollutants from the Liao River source area. The calibration and validation of these models are outlined. The WA-ANN models and the SWAT model were run to generate the spatial distribution of nonpoint source nutrient (nitrogen and phosphorus) exports in the source area of the Liao River. It was found that the SWAT model identified the sub-catchments which not only receive high rainfall but are also densely populated with high agricultural production from dry fields and paddy fields, which are large users of pesticides and chemical fertilizer, as the primary source areas for nutrient exports. It is also concluded that the coupled WA-ANN models and the SWAT model provide a tool which will inform the identification of NPS issues and will facilitate the identification of management practices to improve the water environments in the source area of the Liao River.

  16. Roofing as a source of nonpoint water pollution.

    Science.gov (United States)

    Chang, Mingteh; McBroom, Matthew W; Scott Beasley, R

    2004-12-01

    new wood-shingle roofs were significantly higher than those from aged roofs of a previous study. The study demonstrated that roofs could be a serious source of nonpoint water pollution. Since Zn is the most serious water pollutant and wood shingle is the worst of the four roof types, using less compounds and materials associated with Zn along with good care and maintenance of roofs are critical in reducing Zn pollution in roof runoff.

  17. Review of green roof in controlling unban non-point source pollution%绿色屋顶技术控制城市面源污染应用研究进展

    Institute of Scientific and Technical Information of China (English)

    王书敏; 于慧; 张彬; 邵磊

    2011-01-01

    It has been widely adopted abroad that green roof is an effective mode in controlling Urban Non-point Source Pollution(UNSP),which still belongs to new research fields in China.Based on studies in recent years home and abroad,highlight is given about green roof in controlling unban non-point source pollution from three aspects(i.e.,the reduction and retention of runoff volume,water quality from green roof and the installation method of green roof).Results show that further study is needed for a long time in order to establish the function between stormwater runoff reduction volume and influencing factors;the physical and chemical properties of plants growth media is the key problem affecting runoff water quality.It should follow a wide rang of purposes to install green roofs at home,and the design guidance for green roofs should also be made according to domestic environmental background.The plants growth substrate and the choice of plants are primary problems to be ascertained.%应用绿色屋顶技术控制城市面源污染在欧美国家已得到广泛认同和应用,但在国内尚处于起步阶段.根据国内外最近几年的研究情况,从绿色屋顶消减暴雨径流、绿色屋顶径流水质、绿色屋顶构建方法等方面详细介绍了绿色屋顶技术在控制城市面源污染中的应用研究情况.研究结果表明,建立绿色屋顶暴雨径流消减量与影响因子的映射关系仍需要大量的、长期的研究;植物生长介质的理化性质是影响绿色屋顶径流水质的关键.在国内构建绿色屋顶,应遵循构建目的多元化的原则,逐步建立起适合国内国情的新的绿色屋顶构建导则,其中,植物生长基质搭配方式和植物选取是需要重点明确的问题.

  18. [Three patterns of interaction between soil and non-point source P-pollutants in agricultural watershed].

    Science.gov (United States)

    Wang, Xia-hui; Yin, Cheng-qing; Yan, Xiao; Shan, Bao-qing; Wang, Wei-dong

    2004-07-01

    Typical agricultural watershed was selected to study the interactions between soil matrix and non-point source P-pollutants in surface runoff under simulative conditions. The soil samples were taken in different spatial locations in this watershed and were under different degree of human disturbance. The results showed that the interactions between different soil matrix and phosphorus could be divided into three patterns:retention, release and combination of retention and release. Soil of retention pattern has strong adsorption capacity of phosphate and will retain phosphorus from polluted runoff. Soil of release pattern has significant desorption capacity of phosphate and will release phosphorus to the runoff. Soil of retention and release combination pattern will retain or release phosphorus according to the phosphate concentration in the polluted runoff. These results showed that soil matrix in different spatial locations in the agricultural watershed have different ecological functions and environmental values under the processing of natural conditions and human disturbance. From the view of occurrence of non-point source pollution, these soils could become the sink of pollutants as well as the source of pollutants. Under some conditions, there has a conversion between sink and source of them. These results are valuable for control of non-point source pollution on watershed level, identification of key source area of pollutants and improvement of efficiency of control measures.

  19. Research Progress on Guangdong Agricultural Non-point Source Pollution Control-Conservation Agriculture Project%广东农业面源污染治理保护性耕作项目研究进展

    Institute of Scientific and Technical Information of China (English)

    任小平; 区颖刚; 杨丹彤; 唐湘如; 胡建广

    2015-01-01

    广东省属于农业大省,近年来随着人口增加和农村经济快速发展,农业面源污染形势十分严峻.广东省承担的世界银行农业面源污染治理保护性耕作项目,通过在省内的项目示范区域进行水稻和甜玉米的示范试验,探索保护性耕作减少农业面源污染源的作用和方法.项目组设计了免耕和少耕插秧、免耕和少耕直播4种主要模式,投入了50多台套农业机械,经过4个试验点1年的试验,初步结果表明,南方高温潮湿地区水稻和甜玉米生产采用保护性耕作技术是有效果的,所选的农机具大多数是适用的,部分北方旱地机械还需要改进.讨论了广东保护性耕作存在的问题和改进的意见.%Guangdong province is an important agricultural province. The agricultural non-point source pollution situation is very grim in recent years as the population increases and the rural economy grows rapidly. Explo-ration, supported by the world bank agriculture non-point source pollution control-conservation tillage project, has been undertaken in Guangdong province to discover the roles and methods for reducing agricultural non-point source pollution by conservation tillage. The project is conducted in four paddy rice and sweet corn demonstration and experimental sites in the province. Four main models, the no-till and less-till transplanting, no-till and less-till direct seeding, have been designed by the project team. More than 50 sets of agricultural machines have been put into the experiments. After one year's experiments conducted in four sites, prelimi-nary results show that the conservation tillage technology is effective in the paddy rice and sweet corn produc-tion in southern area with high temperature and wet conditions. Most of the selected farm machines are appli-cable. Some of the northern dryland machines need to be improved. The paper discussed the problems and im-provement opinions existing in the Guangdong conservation

  20. SPATIAL ANALYSIS OF SOIL EROSION AND NON-POINT SOURCE POLLUTION BASED ON GIS IN ERLONG LAKE WATERSHED, JILIN PROVINCE

    Institute of Scientific and Technical Information of China (English)

    WANG Ning; ZHANG Hong-yan; WANG Hui-lian; ZHANG Zheng-xiang

    2004-01-01

    Data collection, factor composition, nappe analysis and integrative simulation of natural geographical factors in Erlong Lake watershed have been carried out based on GIS. The risk areas where non-point source pollution may occur were compartmentalized and assessed, and the total soil erosion and the runoffs of N and P with rainfall in this valley were worked out by experiment and GIS mapping. The study indicated that the main type of soil in dry land with variable slope east of the lake and the middle-south parts of steep slope mountainous region (erosion source pollution (NSP) of nitrogen and phosphorus loss was corresponded with the soil erosion. Spatial distribution and the reasons of the distribution difference have been presented and it was emphasized that the human activities among the influence factors was the most important. It surely offers a scientific basis to control and prevent non-point source pollution in the watershed.

  1. 我国农业面源污染现状及其对策研究%Review of the current situation and control countermeasures in agricultural non-point source pollution control in China

    Institute of Scientific and Technical Information of China (English)

    李自林

    2013-01-01

    随着我国经济的快速发展,农业面源污染已成为我国环境污染的主要原因之一。农业面源污染制约农业可持续发展,已成为亟待解决的环境问题。目前,造成农业面源污染的原因主要是化肥农药的过量施用和流失,畜禽和水产养殖业污染,水土流失,作物秸秆大量废弃以及农膜污染。农业面源污染具有分散性、广泛性、随机性等特征,对土壤、水体、大气造成负面影响。本文针对农业面源污染问题,从生物、物理、化学以及农业管理等角度提出了相应的防治对策及措施,以期有效治理农业面源污染,保护环境,促进农业可持续发展。%Agricultural non-point source pollution is the main factor to the environmental pollution in rural China now with the development of economy in China .It has gained the attention of the government and scientist in the country , and also is the main factor to restrain the agricultural sustainable development .At present ,the reasons are list as follow :chemical fertilizer and pesticide and excessive application ;Livestock and aquatic products pollution ;soil erosion ;a ma-jority of strews abandoned ;agricultural plastic film pollution .It has the characteristics of dispensability ,universality and randomness ,which have negative effects on soil ,water and air .In terms of biological chemistry and physics and agricul-tural management ,this paper proposes countermeasures to control agricultural non -point source pollution ,protect the environment ,and promote the sustainable development of agriculture .

  2. 苏州市农业面源污染现状与控制研究%Current situation and control recommendations of agricultural non-point source pollution in Suzhou City

    Institute of Scientific and Technical Information of China (English)

    张贵龙; 秦伟; 管永祥; 邱丹; 杨殿林; 赵建宁

    2011-01-01

    Based on the results of national survey of pollution sources, the production and emission characteristics of pollutants from agricultural activities and the major control measures of agricultural non-point source pollution in Suzhou along the Yangtze River, Taihu Lake and Yangchenghu Lake were analyzed and demonstrated. The results showed that among the non-point source pollutants, the totalamount of nitrogen and phosphorus emitted were 11 878.9 and 1 343.8 t respectively, pesticides loss was 28.0 t, plastic membrane residual was 203.9 t, the volume of straw burned was 214 000 t, total amount of COD emitted by livestock breeding, aquaculture and rural community was 92 360.3 t; The emission amount of nitrogen and phosphorus along the Yangtze River was the largest followed by Taihu Lake, along the Yangcbenghu Lake the lowest. According to the analysis of the total amount of N and P emitted, the ranking of pollutant resource was as below: rural community > livestock breeding >aquaculture > planting; The pollution intensity caused by the four sources were different. The three watershed, the pollution intensity of farming, animal husbandry and rural communities was greater in the Yangtze River, but the pollution intensity of aquaculture was greater in Taihu Lake Therefore,in guiding concept for the prevention and control of no point source pollution, the government should pay close attention to the Yangtze River, give more weight to domestic pollution sources. In view of the above -mentioned facts,to control agricultural non-point source pollution. Some proposals were offered as follows, concentrating superior resources to dispose rural sewage, optimizing the agricultural industry structure, strengthening the ecological construction, comprehensively treating livestock pollution, promoting the utilization of crop straw resources,and reasonably planning aquaculture etc.%利用提供的区城产排污系数,对苏州市沿长江、太湖和阳澄湖流域农业面

  3. Farmers’ Willingness to Pay( WTP ) for Reducing Agricultural Non-point Source Pollution: Based on the Empirical Analysis of 453 Farmers

    Institute of Scientific and Technical Information of China (English)

    Qian; BI; Huaiye; WANG; Yongyan; ZUO

    2014-01-01

    With the rapid development of modern agriculture,agricultural non-point source pollution becomes increasingly serious in China,improving farmers’ environmental protection consciousness plays a very important role in the reduction of agricultural non-point source pollution,and the WTP of Farmers for controlling agricultural non-point source pollution strongly reflects the strength of their environmental protection consciousness. Therefore,this investigation and study choose rural areas of five counties from Chongqing city and Zhejiang province as our sample,respectively make interview survey with the WTP(money or voluntary work) of farmers for improving local water and soil quality. Based on the statistical analysis of survey data,this study also takes empirical test and analysis with the influence factors on the WTP of farmers for reducing agricultural non-point source pollution. The analysis and conclusions of this research provides the supports in theory and practice for optimizing farmers’ behavior,promoting the management of agricultural non-point source pollution and implementing new rural construction goal.

  4. Nonpoint-Source Pollution Issues. January 1990-November 1994. QB 95-01. Quick Bibliography Series.

    Science.gov (United States)

    Makuch, Joe

    Citations in this bibliography are intended to be a substantial resource for recent investigations (January 1990-November 1994) on nonpoint source pollution and were obtained from a search of the National Agriculture Library's AGRICOLA database. The 196 citations are indexed by author and subject. A representation of the search strategy is…

  5. Estimation of Non-point Source Pollution Loads Under Uncertain Information

    Institute of Scientific and Technical Information of China (English)

    LI Ruzhong

    2008-01-01

    Many kinds of uncertainties are involved, such as random, fuzzy, grey, unascertained property and so on, in soil erosion process. To exactly predict the non-point source pollution loads, some uncertainties should be taken into consideration. Aiming at the deficiency of present blind number theory being helpless for fuzziness, a novel blind number, i.e. extended-blind number, was introduced by substituting a set of triangular fuzzy numbers (TFNs), ex-pressed as α-cuts, for interval values in present blind number, and the expected value of extended-blind number was also brought forward by referring to the current blind number theory. On the basis of denoting the parameters of Uni-versal Soil Loss Equation (USLE) as extended-blind parameters, a novel USLE model was established for quantita-tively evaluating soil erosion loss and non-point source pollution loads. As a case, the uncertain USLE was employed for predicting the soil erosion loss and non-point source pollution loads of absorbed nitrogen and phosphorus in a dis-trict in the Hangbu-Fengle River basin, in the upstream of Chaohu Lake watershed. The results show that it is feasible in theory to extend blind number into fuzzy environment and reliable on conclusion to apply extended-blind number theory for predicting non-point source pollution loads.

  6. Introducing nonpoint source transferable quotas in nitrogen trading: The effects of transaction costs and uncertainty.

    Science.gov (United States)

    Zhou, Xiuru; Ye, Weili; Zhang, Bing

    2016-03-01

    Transaction costs and uncertainty are considered to be significant obstacles in the emissions trading market, especially for including nonpoint source in water quality trading. This study develops a nonlinear programming model to simulate how uncertainty and transaction costs affect the performance of point/nonpoint source (PS/NPS) water quality trading in the Lake Tai watershed, China. The results demonstrate that PS/NPS water quality trading is a highly cost-effective instrument for emissions abatement in the Lake Tai watershed, which can save 89.33% on pollution abatement costs compared to trading only between nonpoint sources. However, uncertainty can significantly reduce the cost-effectiveness by reducing trading volume. In addition, transaction costs from bargaining and decision making raise total pollution abatement costs directly and cause the offset system to deviate from the optimal state. While proper investment in monitoring and measuring of nonpoint emissions can decrease uncertainty and save on the total abatement costs. Finally, we show that the dispersed ownership of China's farmland will bring high uncertainty and transaction costs into the PS/NPS offset system, even if the pollution abatement cost is lower than for point sources.

  7. Another Look at the Income Elasticity of Non-point Source Air Pollutants: A Semiparametric Approach

    NARCIS (Netherlands)

    Roy, N.; Kooten, van G.C.

    2004-01-01

    In this paper, a semiparametric model is used to examine the relationship between pollution and income for three non-point source pollutants. Statistical tests reject the quadratic specification in favor of the semiparametric model in all cases. However, the results do not support the inverted-U hyp

  8. The Degree of Farmers’ Cognition on Non-point Source Pollution:Based on the Statistical Analysis of 453 Farmers

    Institute of Scientific and Technical Information of China (English)

    Qian; BI; Huaiye; WANG; Jue; PENG

    2014-01-01

    With the rapid development of modern agriculture,agricultural non-point source pollution becomes increasingly serious in China,improving farmers’ environmental protection consciousness plays a very important role in the reduction of agricultural non-point source pollution.Therefore,this investigation and study chooses rural areas of five counties from Chongqing city and Zhejiang province as our samples,our investigation and statistical analysis includes the following four aspects:farmers’ cognition on non-point source pollution concept,farmers’ cognition to rural environment satisfaction,farmers’ cognition on non-point source pollution in agricultural production and farmers’ cognition on the consequences of agricultural non-point source pollution and the effects on ecological environment.The analysis and conclusions of farmers’ consciousness cognition on agricultural non-point source pollution,provides the supports in theory and practice for optimizing the behavior of farmers,promoting the management of agricultural non-point source pollution and implementing new rural construction goal.

  9. Synthesis of lignin-based copolymer LSAA and the application on controlling non-point source pollution (NPS) resulted from surface runoff

    Institute of Scientific and Technical Information of China (English)

    LIU Chen; WU Guangxia; MU Huanzhen; YUAN Zonghuan; TANG Lianyi; LIN Xiangwei

    2008-01-01

    In this article, alkali lignin separated from paper pulp waste was grafted into a novel copolymer LSAA (a copolymer of lignin, starch, acrylamide and acrylic acid). Its practical application effect and environmental safety were studied. The results of field simulation experiment indicated that the application of LSAA significantly affected the output of the runoff and pollutants. The runoff quantity was decreased by 16.67%-47.00% and the loads of total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) were reduced by 17.78%-62.14%, 26.32%-59.91%, 26.67%-42.86%, and 22.18%-52.78%, respectively. Tests on its environmental safety showed that LSAA did no harm the soil. Compared with polyacrylamide (PAM), a dominant product in this field, LSAA exhibited similar effects and cheap cost. Thus, this study not only created a new product for controlling runoff water quality but also offered a beneficial application for industrial paper waste.

  10. Assessment of nonpoint-source runoff in a stream using in situ and laboratory approaches

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, K.A.; Burton, G.A. Jr.

    1999-12-01

    Anthropogenic activities that change a watershed can cause adverse impacts to receiving water. Agricultural and urban runoff are the two leading causes of surface-water impairment in the US. When assessing pollutant sources and their effects on aquatic ecosystems, and prior to implementing source controls, it is necessary to define the systems stressors and receptors of exposure. Toxicity assays are a key component to integrative assessments that include habitat (physical), chemical, and indigenous community characterization. Traditional toxicity assay methods and the use of water-quality criteria are often inappropriate because of exposure design and effect assumptions. Hyalella azteca and Chironomus tentans were exposed in situ for varying time periods during both low- and high-flow conditions to determine the effect of urban and agricultural runoff. Short-term chronic and acute toxicity of urban and agricultural runoff was then measured in the laboratory and related to in situ test results. Nonpoint-source (NPS) runoff from urban areas was often more acutely toxic to organisms in the laboratory as compared to in situ results. Conversely, toxicity to the organisms was greater at the agricultural site during in situ exposures when compared to laboratory. In situ assays were an essential and integral component of NPS runoff assessments. They provided unique information that complemented laboratory toxicity, habitat, benthic community, and physicochemical characterizations.

  11. Review on super absorbent polymer application for improving fertilizer efficiency and controlling agricultural non-point source pollutions%高吸水树脂保水剂提高肥效及减少农业面源污染

    Institute of Scientific and Technical Information of China (English)

    廖人宽; 杨培岭; 任树梅

    2012-01-01

    Super absorbent polymer (SAP) is a new type of multifunctional material in drought resistant and pollution control. SAP can quickly absorb water and fertilizer for increasing soil crumb structure and porosity, restraining soil evaporation, promoting crop physiological function and reducing fertilizer loss, so as to result in significant improvement of water and fertilizer use efficiency and marked reduction in fertilizer pollution. In recent years, SAP has been widely used in agricultural nonpoint source pollution control as a chemical product of absorbing and storing water and fertilizer. The paper expounds its acting mechanism and efficiency in controlling pollution, introduces the researches on its main antifouling function, and emphatically summarizes the researches of SAP application in agricultural production and the development of agricultural antifouling absorbent agent. In the end, the problems existing in the field are discussed and the future research fields are proposed.%高吸水树脂(保水剂)是一种新型多功能抗旱、防污材料,能够快速吸持水肥,增加土壤团粒结构和孔隙度,抑制土面蒸发,提升作物生理机能,减少养分淋失,从而达到提高水肥利用效率和减少肥料污染的作用.近年来,保水剂在农业面源污染防治方面得到了越来越广泛的应用.该文阐述了保水剂的防污作用机理及效能,介绍了保水剂主要防污作用方面的研究,重点对保水剂在农业生产上的防污应用及农用防污型保水剂的研制进行了综述,最后分析了保水剂在农业防污应用和研究过程中存在的问题,提出了保水剂未来进行防污应用的研究方向.

  12. Agriculture Non-Point Source Pollution Control

    OpenAIRE

    2003-01-01

    The Chesapeake Bay is the largest and historically most productive estuary in the United States. It is approximately 200 miles long and 35 mile wide at it broadest point. The Bay's watershed includes parts of six states (Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia, and the entire District of Columbia. This area encompasses 64,000 square-miles, 150 major rivers and s...

  13. Can We Manage Nonpoint-Source Pollution Using Nutrient Concentrations during Seasonal Baseflow?

    Directory of Open Access Journals (Sweden)

    James A. McCarty

    2016-05-01

    Full Text Available Nationwide, a substantial amount of resources has been targeted toward improving water quality, particularly focused on nonpoint-source pollution. This study was conducted to evaluate the relationship between nutrient concentrations observed during baseflow and runoff conditions from 56 sites across five watersheds in Arkansas. Baseflow and stormflow concentrations for each site were summarized using geometric mean and then evaluated for directional association. A significant, positive correlation was found for NO–N, total N, soluble reactive P, and total P, indicating that sites with high baseflow concentrations also had elevated runoff concentrations. Those landscape factors that influence nutrient concentrations in streams also likely result in increased runoff, suggesting that high baseflow concentrations may reflect elevated loads from the watershed. The results highlight that it may be possible to collect water-quality data during baseflow to help define where to target nonpoint-source pollution best management practices within a watershed.

  14. Percentage of probability of nonpoint-source nitrate contamination of recently recharged ground water in the High Plains aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents the percentage of probability of nonpoint-source nitrate contamination (greater than the proposed background concentration of 4...

  15. FY1995 contaminant study proposal : CO-nonpoint source pollution on the Rocky Mountain Arsenal National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Proposal to determine the extent of nonpoint source pollution to water bodies on the Rocky Mountain Arsenal National Wildlife Refuge (Arsenal). The Service will...

  16. Relationship Between Non-Point Source Pollution and Korean Green Factor

    OpenAIRE

    Seung Chul Lee; In-Hyeok Park; Byung Sik Kim; and Sung Ryong Ha

    2015-01-01

    In determining the relationship between the rational event mean concentration (REMC) which is a volume-weighted mean of event mean concentrations (EMCs) as a non-point source (NPS) pollution indicator and the green factor (GF) as a low impact development (LID) land use planning indicator, we constructed at runoff database containing 1483 rainfall events collected from 107 different experimental catchments from 19 references in Korea. The collected data showed that EMCs were not correlated wit...

  17. An interdisciplinary assessment of regional-scale nonpoint source ground-water vulnerability; theory and application

    Science.gov (United States)

    Bernknopf, Richard L.; Dinitz, Laura B.; Loague, Keith

    2001-01-01

    An integrated earth science-economics model, developed within a geographic information system (GIS), combines a regional-scale nonpoint source vulnerability assessment with a specific remediation measure to avoid unnecessary agricultural production costs associated with the use of agrochemicals in the Pearl Harbor basin on the island of Oahu, Hawaii. This approach forms the core of a risk-based regulation for the application of agrochemicals and estimates the benefits of an information-based approach to decisionmaking.

  18. THE METHOD OF CAR HEADLIGHTS LUMINOUS INTENSITY MEASURING FOR NON-POINT SOURCES OF LIGHT

    Directory of Open Access Journals (Sweden)

    A. Kupko

    2015-12-01

    Full Text Available It is shown that the measurements of luminous intensity of car headlights luminous intensity for non-point sources have pecularities. A simplified method for correction the luminous intensity at various distances is developed. The applicability of the given method with possible measurement errors is studied. The results were obtained, using a stand of the National Scientific Center “Institute of Metroligy”.

  19. Managing Nonpoint Source Pollution in Western Washington: Landowner Learning Methods and Motivations

    Science.gov (United States)

    Ryan, Clare M.

    2009-06-01

    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.

  20. [Nonpoint pollution control for rural areas of China with ecological engineering technologies].

    Science.gov (United States)

    Yin, Chengqing; Mao, Zhanpo

    2002-02-01

    Nonpoint pollution from rural areas is the results of the ecosystem degradation, and ecological engineering technologies are good ways for the restoration of watershed and enhancing material cycling. There are two types of treatment strategies: to control the polluted runoff and to reduce the pollutants from the sources. Six control technologies are introduced and they are multipond systems, grassed filter trips, wetland systems, eco-agriculture, slope ecological engineering, ecological treatment of wastewater and solid waste. These technologies need to be combined systematically in order to form a watershed ecological engineering. In the control program, it is important to use countermeasure suitable to the local conditions. In addition, the input of sufficient investment, management and education is necessary.

  1. Parameter uncertainty analysis of non-point source pollution from different land use types.

    Science.gov (United States)

    Shen, Zhen-yao; Hong, Qian; Yu, Hong; Niu, Jun-feng

    2010-03-15

    Land use type is one of the most important factors that affect the uncertainty in non-point source (NPS) pollution simulation. In this study, seventeen sensitive parameters were screened from the Soil and Water Assessment Tool (SWAT) model for parameter uncertainty analysis for different land use types in the Daning River Watershed of the Three Gorges Reservoir area, China. First-Order Error Analysis (FOEA) method was adopted to analyze the effect of parameter uncertainty on model outputs under three types of land use, namely, plantation, forest and grassland. The model outputs selected in this study consisted of runoff, sediment yield, organic nitrogen (N), and total phosphorus (TP). The results indicated that the uncertainty conferred by the parameters differed among the three land use types. In forest and grassland, the parameter uncertainty in NPS pollution was primarily associated with runoff processes, but in plantation, the main uncertain parameters were related to runoff process and soil properties. Taken together, the study suggested that adjusting the structure of land use and controlling fertilizer use are helpful methods to control the NPS pollution in the Daning River Watershed.

  2. Event-based nonpoint source pollution prediction in a scarce data catchment

    Science.gov (United States)

    Chen, Lei; Sun, Cheng; Wang, Guobo; Xie, Hui; Shen, Zhenyao

    2017-09-01

    Quantifying the rainfall-runoff-pollutant (R-R-P) process is key to regulating non-point source (NPS) pollution; however, the impacts of scarce measured data on R-R-P simulations have not yet been reported. In this study, we conducted a comprehensive study of scarce data that addressed both rainfall-runoff and runoff-pollutant processes, whereby the impacts of data scarcity on two commonly used methods, including Unit Hydrograph (UH) and Loads Estimator (LOADEST), were quantified. A case study was performed in a typical small catchment of the Three Gorges Reservoir Region (TGRR) of China. Based on our results, the classification of rainfall patterns should be carried out first when analyzing modeling results. Compared to data based on a missing rate and a missing location, key information generates more impacts on the simulated flow and NPS loads. When the scarcity rate exceeds a certain threshold (20% in this study), measured data scarcity level has clear impacts on the model's accuracy. As the model of total nitrogen (TN) always performs better under different data scarcity conditions, researchers are encouraged to pay more attention to continuous the monitoring of total phosphorus (TP) for better NPS-TP predictions. The results of this study serve as baseline information for hydrologic forecasting and for the further control of NPS pollutants.

  3. Management of unregulated agricultural nonpoint sources through water quality trading market.

    Science.gov (United States)

    Mahjoobi, Emad; Sarang, Amin; Ardestani, Mojtaba

    2016-11-01

    Water quality trading (WQT) could be an innovative policy to incentivize farmers to implement best management practices (BMPs) for their activities. This study focused on assessment of involving unregulated agricultural nonpoint sources (NPS) into the WQT market in Gharesoo watershed in the west of Iran. It also proposes a methodology to determine location-based trading ratios as well as environmental penalty cost to achieve a more well-designed market structure. Trading activities in different scenarios were described by trading volume (TV), participation rate (PR), total exchanged value (TEV), and other market parameters in order to achieve a better comparison of market performance. Results showed that, by applying NPS to the Gharesoo watershed, total phosphorous (TP) trading market could increase TV, PR, and TEV up to 11, 1.7 and 7.5 times, respectively, depending on which level of BMPs are implemented by them. Additionally, it could save 29% of the total cost of implementing a TP total maximum daily load in this watershed compared to the 'command and control' approach. Furthermore, the agricultural sector could profit by $5.49 million (or $75/ha) by choosing solutions such as terrace systems and filter strips to register into the market. This profit can be allocated to the development of new agricultural technologies.

  4. Multi-Scale Monitoring and Assessment of Nonpoint Source Pollution in Groundwater

    Science.gov (United States)

    Harter, T.; Vanderschans, M.; Leijnse, A.; Mathews, M. C.; Meyer, R. D.

    2003-04-01

    The California dairy industry produces 20% of US milk and is the largest animal industry in the state. Many of the dairy facilities are located in low-relief valleys and basins with vulnerable groundwater resources. The continued influx of dairies into California's Central Valley has raised critical questions regarding their environmental performance, in particular with respect to groundwater quality impacts. While animal farming systems are considered among the leading sources of groundwater nitrate,little is known about the actual impact of dairy farming practices on groundwater quality in the extensive alluvial aquifers underlying the Central Valley. With our work we attempt to characterize and assess shallow groundwater underneath dairies in a relatively vulnerable hydrogeologic region and to discern the impact from various individual sources and management practices within dairies. An extensive shallow groundwater monitoring network was installed on five representative dairy operations in the northeastern San Joaquin Valley, California. The monitoring network spans all dairy management units: manure water lagoons, corrals, storage areas, and manure treated forage fields under various management practices. We recently also surveyed production well water quality. Water quality is found to be highly variable, both in time and space. We propose that a meaningful interpretation of these (nonpoint source pollution) data is only possible by explicitly considering the various scales affiliated with groundwater measurement, pollution source management, regulatory control, and beneficial use. Using statistical analysis and innovative modeling tools, we provide an interpretation of the observed data that is meaningful at the field scale (the scale unit of management decisions), the farm scale (considered to be a regulatory and planning unit), and the regional scale (considered to be a planning unit).

  5. Got Milk? Got Water? Innovative Approach to Evaluating Groundwater Nitrate Nonpoint Source Pollution from Animal Farming

    Science.gov (United States)

    Harter, T.; Vanderschans, M.; Leijnse, A.; Meyer, R. D.; Mathews, M. C.

    2002-12-01

    The California dairy industry produces 20% of US milk and is the largest animal industry in the state. Many of the dairy facilities are located in low-relief valleys and basins with vulnerable groundwater resources. The continued influx of dairies into California's Central Valley has raised critical questions regarding their environmental performance, in particular with respect to groundwater quality impacts. While animal farming systems are considered among the leading sources of groundwater nitrate,little is known about the actual impact of dairy farming practices on groundwater quality in the extensive alluvial aquifers underlying the Central Valley. With our work we attempt to characterize and assess shallow groundwater underneath dairies in a relatively vulnerable hydrogeologic region and to discern the impact from various individual sources and management practices within dairies. An extensive shallow groundwater monitoring network was installed on five representative dairy operations in the northeastern San Joaquin Valley, California. The monitoring network spans all dairy management units: manure water lagoons, corrals, storage areas, and manure treated forage fields under various management practices. We recently also surveyed production well water quality. Water quality is found to be highly variable, both in time and space. We propose that a meaningful interpretation of these (nonpoint source pollution) data is only possible by explicitly considering the various scales affiliated with groundwater measurement, pollution source management, regulatory control, and beneficial use. Using statistical analysis and innovative modeling tools, we provide an interpretation of the observed data that is meaningful at the field scale (the scale unit of management decisions), the farm scale (considered to be a regulatory and planning unit), and the regional scale (considered to be a planning unit).

  6. 林带对太湖地区农业非点源的控制效应研究%Controlling effects of forest belts on non-point source pollution of agricultural lands in Taihu Lake area, China

    Institute of Scientific and Technical Information of China (English)

    陈金林; 侍璐璐; 张爱国

    2002-01-01

    in water, crops and underground of forest, the transfer and loss of N and P (main water pollutants) in faming ecosystem were studied, and the effects of forest belts on non-point source pollution of agricultural lands was analyzed. The results indicated that the transfer and loss of N and P vary with means of rotation, types of crops and the amount of fertilizer application. Buffering forest belts betweens farmlands and ditches can effectively stop and purify such elements as N and P in soil runoffs, thus controlling non-point source pollution of agricultural lands. When the width ratio of farmland to forest belt is 100 to 40, 50.05% losing N, 29.37% losing P can be absorbed by forest under rape-rice rotation and 30.98% N, 86.73% P can be absorbed by forest under wheat-rice rotation. When the width ratio of farmland to forest belt is 150 to 40, 33.37% losing N, 19.58% losing P can be absorbed by the forest under rape-rice rotation, and under wheat-rice rotation 20.65% lost N and 57.82% lost P can be absorbed. There is only some purification effect when the width ration of farmland to forest belt is 200 to 40. Based on model of buffering forest belts, the width ratio of farmland to forest is determined between 100 to 40 and 150 to 40, because it not only can purify water, but also occupy less farmland. It is suggested that Poplars, with the characteristics of fast-growing and high value, are suitable to be planted as shelter-forest in Taihu Lake Watershed.

  7. Optimization of Policy and Management Service System on Control of Rural Non-Point Source Pollution-A Case Study of the Rural Area of Shanghai%农村面源污染治理的政策与管理服务体系优化——以上海郊区农村为例

    Institute of Scientific and Technical Information of China (English)

    黄文芳; 沈哲

    2012-01-01

    It is a common view that control of rural non-point source pollution is not only a technology issue, but also a management system issue. So hard currently it has become a hot spot and a hard nut as well to probe and consummate the policy, management and service system for control of rural non-point source pollution. Selecting the rural suburbs of Shanghai for case study, the status quo of the rural non-point source pollution and its management have been analyzed and summarized. While affirming the effect of the current work on pollution management, the limitations of the work are discerned and it was pointed out that inharmony between the agriculture development policy and the environmental protection policy and the lag of the management mechanism and service system behind the change in the rural development model are the basic causes. To counter the major contributors of the rural non-point source pollution, i. e. chemical fertilizers, pesticides , livestock excretes and rural domestic sewage, countermeasures and suggestions are presented for management of the pollution from the aspects of modification of the agricultural subsidization system, reconfiguration and implementation of the rural multi-value system and consummation of agricultural production service system.%农村面源污染控制不仅是技术问题,也是管理体制与机制问题,探讨并完善农村面源污染治理的政策、管理与服务体系已成为当前研究的热点与难点.以上海郊区农村为例,梳理总结农村面源污染及其控制现状;在肯定当前治理效果的同时,识别其局限性,指出农业政策与环境保护政策的不协调、农村发展模式转变下制度与服务体系的相对滞后是根本原因;针对当前农村面源污染重要的贡献者——化肥、农药、畜禽粪便以及农村生活污水,分别从改革农业补贴制度、重构实现农村多重价值的制度以及完善农业生产服务体系等方面给出了治理的对策与建议.

  8. 苏州市东山镇池塘养蟹面源污染现状及控制%Current status and control strategies of non-point source pollution from pond aquaculture in Dongshan town of Suzhou

    Institute of Scientific and Technical Information of China (English)

    宋学宏; 郭培红; 孙丽萍; 朱江

    2011-01-01

    结合全国污染源普查活动,以苏州市养殖老区东山镇养殖池塘为典型,调查其现行养殖模式、经济效益、养殖污染状况.调查结果显示,东山镇现有养殖面积为2253.33hm2,主养品种为河蟹.1个养殖周期中,养殖池塘通过沟渠排入外界的TN、TP含量分别平均为21.25kg/hm2、2.34kg/hm2;密度为9000只/hm2的低密度养殖池外排的TN含量为16.79kg/hm2,而无TP排出.分析苏州地区池塘养殖产生水环境污染的主要原因,从池塘管理体制改革、科学生态养殖技术及养殖尾水处理等方面探讨池塘养殖污水零排放技术,为苏州市养殖业面源污染的控制提供对策和措施.%Combining with national census of pollution sources and using large-scale pond aquaculture in Dongshan town in Suzhou as a case study, the current cultural modes, economic benefits, and aquaculture pollution were surveyed. The results showed that there were 2 253.33 hm2 of aquaculture in Dongshan town, and the Chinese mitten crab was the main specie. In a single aquaculture period, the discharged total nitrogen (TN) and total phosphorus (TP) from pounds to outside through canals and ditches were on average 21.25 kg/hm2 and 2.34 kg/hm2 respectively. However, in a lowdensity crab raising pond of 9000 ind/hm2, the discharged TN was 16.79 kg/hm2, and no TP was found to be discharged.Based on the case study, the main reasons for the water environment pollution by pond aquaculture were analyzed, and the zero discharge technologies for the waste water of pond aquaculture were discussed from aspects of the management system reform for pond, the scientific and ecological raising technique, and the aquaculture wastewater treatment. The possible strategies and countermeasures for controlling the aquacultural non-point source pollution in Suzhou were also provided.

  9. MODELING OF SEDIMENT AND NONPOINT SOURCE POLLUTANT YIELD

    Institute of Scientific and Technical Information of China (English)

    Huai'en LI; Xiaokang Hong; Bing SHEN

    2001-01-01

    For water and soil conservation and water pollution control, it is very important to simulate and predict the load of sediment and pollutant during storm-runoff. On the basis of analyzing the simultaneous measurements of flow, sediment and pollutants observed at watershed outlet, a practical sediment yield model is developed by standardizing the load rate. The results show that the standardized pollutant yield equals effective rainfall and the process of effective load yield is the same as effective rainfall hyetograph. Comparison with measured data show that this model is applicable to various pollutants.

  10. Investigation and Analysis of Guangzhou Nansha Coast Park Point Source Pollution and Non-point Source Pollution

    Institute of Scientific and Technical Information of China (English)

    Ruijie; YANG; Huanghuang; ZENG; Budan; CHEN; Fang; CHEN; Shikai; WU

    2014-01-01

    [Objective]To find out the situation of Nansha Coast Park point and non-point source pollution.[Method]By investigating the park water environment,analysis of point and non-point source pollutants contribution rate,setting up water quality monitoring sites for basic data related indicators and then using national water quality standards to evaluate water quality.[Result]The Coast Park point source pollution mainly comes from the campus greeting fertilizer spraying.The COD of lakes and river outside the park and ammonia mean concentration belong to grade III.The total nitrogen of lake belongs to grade III.The total phosphorus belongs to grade IV.The total nitrogen of river is the worst.The total phosphorus is grade V.[Conclusion] The lake water quality is highly affected by the point and non-point source pollution,the quality of the river is worse than that of the lake in the park,and it needs powerful governance.

  11. Global Pollution of Surface Waters from Point and Nonpoint Sources of Nitrogen

    Directory of Open Access Journals (Sweden)

    G. van Drecht

    2001-01-01

    Full Text Available Global 0.5- by 0.5-degree resolution estimates are presented on the fate of nitrogen (N stemming from point and nonpoint sources, including plant uptake, denitrification, leaching from the rooting zone, rapid flow through shallow groundwater, and slow flow through deep groundwater to riverine systems. Historical N inputs are used to describe the N flows in groundwater. For nonpoint N sources (agricultural and natural ecosystems, calculations are based on local hydrology, climate, geology, soils, climate and land use combined with data for 1995 on crop production, N inputs from N fertilizers and animal manure, and estimates for ammonia emissions, biological N fixation, and N deposition. For point sources, our estimates are based on population densities and human N emissions, sanitation, and treatment. The results provide a first insight into the magnitude of the N losses from soil-plant systems and point sources in various parts of the world, and the fate of N during transport in atmosphere, groundwater, and surface water. The contribution to the river N load by anthropogenic N pollution is dominant in many river basins in Europe, Asia, and North Africa. Our model results explain much of the variation in measured N export from different world river basins.

  12. Response of non-point source pollutant loads to climate change in the Shitoukoumen reservoir catchment.

    Science.gov (United States)

    Zhang, Lei; Lu, Wenxi; An, Yonglei; Li, Di; Gong, Lei

    2012-01-01

    The impacts of climate change on streamflow and non-point source pollutant loads in the Shitoukoumen reservoir catchment are predicted by combining a general circulation model (HadCM3) with the Soil and Water Assessment Tool (SWAT) hydrological model. A statistical downscaling model was used to generate future local scenarios of meteorological variables such as temperature and precipitation. Then, the downscaled meteorological variables were used as input to the SWAT hydrological model calibrated and validated with observations, and the corresponding changes of future streamflow and non-point source pollutant loads in Shitoukoumen reservoir catchment were simulated and analyzed. Results show that daily temperature increases in three future periods (2010-2039, 2040-2069, and 2070-2099) relative to a baseline of 1961-1990, and the rate of increase is 0.63°C per decade. Annual precipitation also shows an apparent increase of 11 mm per decade. The calibration and validation results showed that the SWAT model was able to simulate well the streamflow and non-point source pollutant loads, with a coefficient of determination of 0.7 and a Nash-Sutcliffe efficiency of about 0.7 for both the calibration and validation periods. The future climate change has a significant impact on streamflow and non-point source pollutant loads. The annual streamflow shows a fluctuating upward trend from 2010 to 2099, with an increase rate of 1.1 m(3) s(-1) per decade, and a significant upward trend in summer, with an increase rate of 1.32 m(3) s(-1) per decade. The increase in summer contributes the most to the increase of annual load compared with other seasons. The annual NH (4) (+) -N load into Shitoukoumen reservoir shows a significant downward trend with a decrease rate of 40.6 t per decade. The annual TP load shows an insignificant increasing trend, and its change rate is 3.77 t per decade. The results of this analysis provide a scientific basis for effective support of decision

  13. Reducing future non-point source sediment and phosphorus loading under intensifying agricultural production in the Ethiopian highlands

    Science.gov (United States)

    Mogus, Mamaru; Schmitter, Petra; Tilahun, Seifu; Steenhuise, Tammo

    2016-04-01

    Intensification of agriculture will bring along non-point source pollution in the Ethiopian highlands resulting in eutrophication of lakes. The first signs of eutrophication have been observed already in Lake Tana. The lake it supports the lives of millions in the surrounding through fishing, tourism, transportation and hydropower.Presently, information on non-point source pollution is lacking in the Ethiopian highlands. There are few studies carried out in the highlands on the extent and the source areas of pollution, and models are not available for predicting sediment and phosphorus loading other than those developed for temperate climates. The objective of this chapter is to review existing non-point source studies, report on our findings of sediment and phosphorus sources that are related the non-point source pollution of Lake Tana and to present a non-point source model for the Ethiopian highland based on the Parameter Efficient Semi-distributed Watershed Hydrology Model (PED-WHM).In our research we have found that the saturation excess runoff from valley bottoms and from degraded lands are prevalent in the Ethiopia highlands. The periodically runoff source areas are also the sources for the non-point source pollution and by concentrating best management practices in these source areas we expect that we can reduce pollution without affecting the profitability of the existing farms. The water balance component of the non-point source model has been performing well in predicting both the discharge and the location of the runoff source areas. Sediment and phosphorus prediction models have been developed and are currently being tested for the 7km2Awramba watershed and the 1350 km2Gumara basin. Initial results indicate that 11.2 ton/ha/year sediment load and an accumulation rate of 17.3 mg/kg/year of dissolved phosphorus from Gumara watershed joining the lake. By developing best management practices at this time before non-point source pollution is rampant and

  14. Landscape planning for agricultural nonpoint source pollution reduction I: a geographical allocation framework.

    Science.gov (United States)

    Diebel, Matthew W; Maxted, Jeffrey T; Nowak, Peter J; Vander Zanden, M Jake

    2008-11-01

    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.

  15. Agricultural non-point source pollution of glyphosate and AMPA at a catchment scale

    Science.gov (United States)

    Okada, Elena; Perez, Debora; De Geronimo, Eduardo; Aparicio, Virginia; Costa, Jose Luis

    2017-04-01

    can be attributed to deposition of soil particles that are washed from the field. On the other hand, more than 90 % of the soil samples had glyphosate and AMPA. The highest concentrations were found in the month of June, corresponding to the fallow period were glyphosate is applied as a chemical weed controller in no-till systems. Glyphosate and AMPA detection in groundwater samples was 24% and 35%, respectively. The highest glyphosate levels in groundwater also corresponded to the month of June. Glyphosate occurrence in groundwater was transient, that is, in most of the cases glyphosate was not detected in the subsequent sampling months. The contamination of shallow groundwater (agricultural non-point source pollution in the months of herbicide application, that may contribute to groundwater contamination. This is of extreme relevance in the southeast of the Buenos Aires Province, since the main source of drinking water and irrigation is from groundwater resources

  16. Contribution of base flow to nonpoint source pollution loads in an agricultural watershed

    Science.gov (United States)

    Schilling, K.E.; Wolter, C.F.

    2001-01-01

    Nonpoint source pollution of surface water from overland flow, drainage tiles, and ground water discharge is a major cause of water quality impairment in Iowa. Nonpoint source pollution from base flow ground water was estimated in the Walnut Creek watershed by measuring chemical loads of atrazine, nitrate, chloride, and sulfate at 18 tributary creeks and 19 tiles. Loads were measured during a stable base flow period at creeks and files that discharged into Walnut Creek between two stream gauges. Chemical concentrations of atrazine (restored prairie areas. Three methods were used to estimate base flow discharge in the watershed: (1) Darcy flux; (2) watershed discharge budget; and (3) discharge-drainage area; each yielded similar results (31.2 L/s to 62.3 L/s). Base flow loads to the main channel were estimated by subtracting the loads from the upstream gauge; creeks and tiles, from the total load measured at the downstream gauge station. Base flow concentration for atrazine ranged from 0.15 to 0.29 ??g/L and sulfate concentration ranged from 32 to 64 mg/L, whereas concentrations for nitrate and chloride were negative (-1 to -4 mg/L). Calculated base flow concentrations of atrazine and sulfate appeared to be reasonable estimates, but negative concentrations of nitrate and chloride imply either loss of chemical mass in the stream from upstream to downstream sampling points or measurement error. Load data suggest little contribution from base flow pollutants to Walnut Creek water quality, with most of the pollutant load derived from major tributary creeks. Results from this study have implications for determining total maximum daily loads in agricultural watersheds where contributions from point sources (creeks and tiles) can he used to estimate loads from nonpoint source ground water inputs.Nonpoint source pollution of surface water from overland flow, drainage tiles, and ground water discharge is a major cause of water quality impairment in Iowa. Nonpoint source

  17. The removal of nutrients from non-point source wastewater by a hybrid bioreactor.

    Science.gov (United States)

    Wu, Yonghong; Hu, Zhengyi; Yang, Linzhang; Graham, Bruce; Kerr, Philip G

    2011-02-01

    The aim of this project was to establish an economical and environmentally benign biotechnology for removing nutrients from non-point source wastewater. The proposal involves a hybrid bioreactor comprised of sequential anaerobic, anoxic and aerobic (A(2)/O) processes and an eco-ditch being constructed and applied in a suburban area, Kunming, south-western China, where wastewater was discharged from an industrial park and suburban communities. The results show that the hybrid bioreactor fosters heterotrophic and autotrophic microorganisms. When the hydraulic load is 200 m(3) per day with the running mode in 12h cycles, the removal efficiencies of the nutrients were 81% for TP, 74% for TDP, 82% for TN, 79% for NO(3)-N and 86% for NH(4)-N. The improved bacterial community structure and bacterial habitats further implied enhanced water quality and indicates that the easily-deployed, affordable and environmentally-friendly hybrid bioreactor is a promising bio-measure for removing high loadings of nutrients from non-point source wastewater.

  18. 农业非点源污染研究进展和趋势%The Progress and Trends of Agricultural Non-point Source Pollution Research

    Institute of Scientific and Technical Information of China (English)

    李丽华; 李强坤

    2014-01-01

    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。%According to the current research on agricultural non-point source pollution at home and abroad, the connotation and feature of a-gricultural non-point source pollution were explored in this paper, and then the estimating model of pollution load was concluded briefly. Meanwhile, the paper also listed the means and methods of risk assessment of regional agricultural non-point source pollution and summed up the control technologies from different angles. Finally, the recent much-needed research hotspots and trends were put forward in order to provide reference for further management and control of agricultural non-point source pollution.

  19. The Treatment Train approach to reducing non-point source pollution from agriculture

    Science.gov (United States)

    Barber, N.; Reaney, S. M.; Barker, P. A.; Benskin, C.; Burke, S.; Cleasby, W.; Haygarth, P.; Jonczyk, J. C.; Owen, G. J.; Snell, M. A.; Surridge, B.; Quinn, P. F.

    2016-12-01

    An experimental approach has been applied to an agricultural catchment in NW England, where non-point pollution adversely affects freshwater ecology. The aim of the work (as part of the River Eden Demonstration Test Catchment project) is to develop techniques to manage agricultural runoff whilst maintaining food production. The approach used is the Treatment Train (TT), which applies multiple connected mitigation options that control nutrient and fine sediment pollution at source, and address polluted runoff pathways at increasing spatial scale. The principal agricultural practices in the study sub-catchment (1.5 km2) are dairy and stock production. Farm yards can act as significant pollution sources by housing large numbers of animals; these areas are addressed initially with infrastructure improvements e.g. clean/dirty water separation and upgraded waste storage. In-stream high resolution monitoring of hydrology and water quality parameters showed high-discharge events to account for the majority of pollutant exports ( 80% total phosphorus; 95% fine sediment), and primary transfer routes to be surface and shallow sub-surface flow pathways, including drains. To manage these pathways and reduce hydrological connectivity, a series of mitigation features were constructed to intercept and temporarily store runoff. Farm tracks, field drains, first order ditches and overland flow pathways were all targeted. The efficacy of the mitigation features has been monitored at event and annual scale, using inflow-outflow sampling and sediment/nutrient accumulation measurements, respectively. Data presented here show varied but positive results in terms of reducing acute and chronic sediment and nutrient losses. An aerial fly-through of the catchment is used to demonstrate how the TT has been applied to a fully-functioning agricultural landscape. The elevated perspective provides a better understanding of the spatial arrangement of mitigation features, and how they can be

  20. Long-term vegetation landscape pattern with non-point source nutrient pollution in upper stream of Yellow River basin

    NARCIS (Netherlands)

    Ouyang, W.; Skidmore, A.K.; Toxopeus, A.G.; Hao, F.

    2010-01-01

    Grassland, forest, and farmland are the dominant land covers in upper catchments of the Yellow River and their landscape status has direct connection with dynamics of non-point source (NPS) pollution. Understanding the correlations between landscape variables and different formats of NPS nutrients p

  1. Long-term vegetation landscape pattern with non-point source nutrient pollution in upper stream of Yellow River basin

    NARCIS (Netherlands)

    Ouyang, W.; Skidmore, A.K.; Toxopeus, A.G.; Hao, F.

    2010-01-01

    Grassland, forest, and farmland are the dominant land covers in upper catchments of the Yellow River and their landscape status has direct connection with dynamics of non-point source (NPS) pollution. Understanding the correlations between landscape variables and different formats of NPS nutrients p

  2. Modified Weighting for Calculating the Average Concentration of Non-Point Source Pollutant

    Institute of Scientific and Technical Information of China (English)

    牟瑞芳

    2004-01-01

    The concentration of runoff depends upon that of soil loss and the latter is assumed to be linear to the value of EI that equals the product of total storm energy E times the maximum 30-min intensity I30 for a given rainstorm. Usually, the maximum accumulative amount of rain for a rainstorm might bring on the maximum amount of runoff, but it does not equal the maximum erosion and not always lead the maximum concentration. Thus, the average concentration weighted by amount of runoff is somewhat unreasonable. An improvement for the calculation method of non-point source pollution load put forward by professor Li Huaien is proposed. In replacement of the weight of runoff, EI value of a single rainstorm is introduced as a new weight. An example of Fujing River watershed shows that its application is effective.

  3. Isotopic Tracers for Delineating Non-Point Source Pollutants in Surface Water

    Energy Technology Data Exchange (ETDEWEB)

    Davisson, M L

    2001-03-01

    This study tested whether isotope measurements of surface water and dissolved constituents in surface water could be used as tracers of non-point source pollution. Oxygen-18 was used as a water tracer, while carbon-14, carbon-13, and deuterium were tested as tracers of DOC. Carbon-14 and carbon-13 were also used as tracers of dissolved inorganic carbon, and chlorine-36 and uranium isotopes were tested as tracers of other dissolved salts. In addition, large databases of water quality measurements were assembled for the Missouri River at St. Louis and the Sacramento-San Joaquin Delta in California to enhance interpretive results of the isotope measurements. Much of the water quality data has been under-interpreted and provides a valuable resource to investigative research, for which this report exploits and integrates with the isotope measurements.

  4. User's Guide for the Agricultural Non-Point Source (AGNPS) Pollution Model Data Generator

    Science.gov (United States)

    Finn, Michael P.; Scheidt, Douglas J.; Jaromack, Gregory M.

    2003-01-01

    BACKGROUND Throughout this user guide, we refer to datasets that we used in conjunction with developing of this software for supporting cartographic research and producing the datasets to conduct research. However, this software can be used with these datasets or with more 'generic' versions of data of the appropriate type. For example, throughout the guide, we refer to national land cover data (NLCD) and digital elevation model (DEM) data from the U.S. Geological Survey (USGS) at a 30-m resolution, but any digital terrain model or land cover data at any appropriate resolution will produce results. Another key point to keep in mind is to use a consistent data resolution for all the datasets per model run. The U.S. Department of Agriculture (USDA) developed the Agricultural Nonpoint Source (AGNPS) pollution model of watershed hydrology in response to the complex problem of managing nonpoint sources of pollution. AGNPS simulates the behavior of runoff, sediment, and nutrient transport from watersheds that have agriculture as their prime use. The model operates on a cell basis and is a distributed parameter, event-based model. The model requires 22 input parameters. Output parameters are grouped primarily by hydrology, sediment, and chemical output (Young and others, 1995.) Elevation, land cover, and soil are the base data from which to extract the 22 input parameters required by the AGNPS. For automatic parameter extraction, follow the general process described in this guide of extraction from the geospatial data through the AGNPS Data Generator to generate input parameters required by the pollution model (Finn and others, 2002.)

  5. 拉萨河流域非点源污染输出风险评估%Risk assessment of non-point source pollution export in Lasahe basin

    Institute of Scientific and Technical Information of China (English)

    方广玲; 香宝; 杜加强; 王宝良; 张立坤; 胡钰; 徐杰

    2015-01-01

    Identification of the high risk area of non-point source pollution has important practical significance to control non-point source pollution and improve the water environment quality. Lasahe River basin located in the Tibet Autonomous Region of China is important drinking-water source for Lhasa City, Linzhou County and Dangxiong County. Because the underdevelopment of industry and the less discharge of industrial pollutants in this area, non-point source pollution is the most important contributing factor for water pollution. Lhasa River basin is the region of agricultural production base with the densest population in the Tibet Autonomous Region. This study built the output risk model that includes rainfall, topography, and fertilization influence factor, identification the output risk region unit from basin non-point source pollution at all levels object. The risk probability of non-point source pollution was classed into five levels: lowest, lower, moderate, higher and highest. Data used in this study were mainly from remote sensing image, statistical yearbook, and the parameters in output risk model were collected from the literatures. The results showed that risk probability of non-point source pollution output in 1996 and 2010 was 50%and 46.3%respectively. 17.5%in 1996 and 12.6%in 2010 of the study area showed that risk probability of non-point source pollution was more than 70%. The risk probability of non-point source pollution was spatially heterogeneous, corresponding with the attributes of land use types. The areas with highest risk of non-point source pollution were concentrated in farmland, where agricultural activities strengthened, and concentrated in unused land with great ecological vulnerability and sensitivity to external interference. Areas with lowest and lower risk of non-point source pollution mainly distributed in grassland, which has relative stability and robustness. Our study also found that risk probability of non-point source pollution

  6. Tracking Nonpoint Source Nitrogen and Carbon in Watersheds of Chesapeake Bay

    Science.gov (United States)

    Kaushal, S.; Pennino, M. J.; Duan, S.; Blomquist, J.

    2012-12-01

    Humans have altered nitrogen and carbon cycles in rivers regionally with important impacts on coastal ecosystems. Nonpoint source nitrogen pollution is a leading contributor to coastal eutrophication and hypoxia. Shifts in sources of carbon impact downstream ecosystem metabolism and fate and transport of contaminants in coastal zones. We used a combination of stable isotopes and optical tracers to investigate fate and transport of nitrogen and carbon sources in tributaries of the largest estuary in the U.S., the Chesapeake Bay. We analyzed isotopic composition of water samples from major tributaries including the Potomac River, Susquehanna River, Patuxent River, and Choptank River during routine and storm event sampling over multiple years. A positive correlation between δ15N-NO3- and δ18O-NO3- in the Potomac River above Washington D.C. suggested denitrification or biological uptake in the watershed was removing agriculturally-derived N during summer months. In contrast, the Patuxent River in Maryland showed elevated δ15N-NO3- (5 - 12 per mil) with no relationship to δ18O-NO3- suggesting the importance of wastewater sources. From the perspective of carbon sources, there were distinct isotopic values of the δ13C-POM of particulate organic matter and fluorescence excitation emission matrices (EEMS) for rivers influenced by their dominant watershed land use. EEMS showed that there were increases in the humic and fulvic fractions of dissolved organic matter during spring floods, particularly in the Potomac River. Stable isotopic values of δ13C-POM also showed rapid depletion suggesting terrestrial carbon "pulses" in the Potomac River each spring. The δ15N-POM peaked to 10 - 15 per mil each spring suggested a potential manure source or result of biological processing within the watershed. Overall, there were considerable changes in sources and transformations of nitrogen and carbon that varied across rivers and that contribute to nitrogen and carbon loads

  7. [Impacts of the urbanization on waters non-point source pollution].

    Science.gov (United States)

    Yang, Liu; Ma, Ke-Ming; Guo, Qing-hai; Zhao, Jing-zhu

    2004-11-01

    Non-point source (NPS) pollution is the prominent source of water pollution in many countries, included America and China, of the world. Urban NPS pollution was attached little importance for long, compared with agriculture NPS pollution. While urbanization is the dominant form of land-use change in terms of impacts on water quality, the hydrology, other physical properties of watersheds as well as their NPS pollution potential at present. The formation of urban NPS pollution of water could be described by "source-process-sink". Urbanization has changed the source, process and sink of urban NPS pollution. A review was conducted on the international researches of urbanization impacts on NPS pollution in urban water environment from the point of view of "describe-predict and evaluation-application". The studies of urbanization impacts on urban NPS pollution were focused on modeling the process of urban NPS pollution by hydrologic model, predicting the pollutants load of NPS pollution. It is a fresh methodology that the relationship between urbanization and urban NPS pollution of water was analyzed by the method of landscape change and ecological process. The research on temporal-spatial comprehensive impacts of landscape pattern changes, led by urbanization, on the urban NPS pollution will be one of the hotspots.

  8. Landscape planning for agricultural nonpoint source pollution reduction III: Assessing phosphorus and sediment reduction potential

    Science.gov (United States)

    Diebel, M.W.; Maxted, J.T.; Robertson, D.M.; Han, S.; Vander Zanden, M. J.

    2009-01-01

    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. ?? 2008 Springer Science+Business Media, LLC.

  9. Modeling of land use and reservoir effects on nonpoint source pollution in a highly agricultural basin

    Science.gov (United States)

    Wu, Yiping; Liu, Shu-Guang

    2012-01-01

    Nonpoint source (NPS) pollution is tightly linked to land use activities that determine the sources and magnitudes of pollutant loadings to stream water. The pollutant loads may also be alleviated within reservoirs because of the physical interception resulting from changed hydrological regimes and other biochemical processes. It is important but challenging to assess the NPS pollution processes with human effects due to the measurement limitations. The objective of this study is to evaluate the effects of human activities such as land uses and reservoir operation on the hydrological and NPS pollution processes in a highly agricultural area-the Iowa River Basin-using the Soil and Water Assessment Tool (SWAT). The evaluation of model performance at multiple sites reveals that SWAT can consistently simulate the daily streamflow, and monthly/annual sediment and nutrient loads (nitrate nitrogen and mineral phosphorus) in the basin. We also used the calibrated model to estimate the trap efficiencies of sediment (~78%) and nutrients (~30%) in the Coralville Reservoir within the basin. These non-negligible effects emphasize the significance of incorporating the sediment and nutrient removal mechanisms into watershed system studies. The spatial quantification of the critical NPS pollution loads can help identify hot-spot areas that are likely locations for the best management practices.

  10. Loss coefficient of nitrogenous non-point source pollution under various precipitation conditions

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this study,calibrations of non-point source (NPS) pollution models are performed based on Black River basin historical real-time runoff data,sedimentation record data,and NPS sources survey information.The concept of NPS loss coefficient for the watershed or the loss coefficients (LC) for simplicity is brought up by examining NPS build-up and migration processes along riverbanks in natural river systems.The historical data is used for determining the nitrogenous NPS loss coefficient for five land use types including farmland,urban land,grassland,shrub land,and forest under different precipitation conditions.The comparison of outputs from Soil and Water Assessment Tool (SWAT) model and coefficient export method showed that both methods could obtain reasonable LC.The high Pearson correlation coefficient (0.94722) between those two sets of calculation results justified the consistency of those two models.Another result in the study is that different combinations of precipitation condition and land use types could significantly affect the calculated loss coefficient.As for the adsorptive nitrogen,the order of impact on LC for different land use types can be sorted as:farm land > urban land > grassland > shrub land > forest while the order was farmland > grass land > shrub land > forest > urban land for soluble nitrogen.

  11. Modeling of land use and reservoir effects on nonpoint source pollution in a highly agricultural basin.

    Science.gov (United States)

    Wu, Yiping; Liu, Shuguang

    2012-09-01

    Nonpoint source (NPS) pollution is tightly linked to land use activities that determine the sources and magnitudes of pollutant loadings to stream water. The pollutant loads may also be alleviated within reservoirs because of the physical interception resulting from changed hydrological regimes and other biochemical processes. It is important but challenging to assess the NPS pollution processes with human effects due to the measurement limitations. The objective of this study is to evaluate the effects of human activities such as land uses and reservoir operation on the hydrological and NPS pollution processes in a highly agricultural area-the Iowa River Basin-using the Soil and Water Assessment Tool (SWAT). The evaluation of model performance at multiple sites reveals that SWAT can consistently simulate the daily streamflow, and monthly/annual sediment and nutrient loads (nitrate nitrogen and mineral phosphorus) in the basin. We also used the calibrated model to estimate the trap efficiencies of sediment (∼78%) and nutrients (∼30%) in the Coralville Reservoir within the basin. These non-negligible effects emphasize the significance of incorporating the sediment and nutrient removal mechanisms into watershed system studies. The spatial quantification of the critical NPS pollution loads can help identify hot-spot areas that are likely locations for the best management practices.

  12. Uncertainty analysis for an effluent trading system in a typical nonpoint-sources-polluted watershed

    Science.gov (United States)

    Chen, Lei; Han, Zhaoxing; Wang, Guobo; Shen, Zhenyao

    2016-07-01

    Conventional effluent trading systems (ETSs) between point sources (PSs) and nonpoint sources (NPSs) are often unreliable because of the uncertain characteristics of NPSs. In this study, a new framework was established for PS-NPS ETSs, and a comprehensive analysis was conducted by quantifying the impacts of the uncertainties associated with the water assimilative capacity (WAC), NPS emissions, and measurement effectiveness. On the basis of these results, the uncertain characteristics of NPSs would result in a less cost-effective PS-NPS ETS during most hydrological periods, and there exists a clear transition occurs from the WAC constraint to the water quality constraint if these stochastic factors are considered. Specifically, the emission uncertainty had a greater impact on PSs, but an increase in the emission or abatement uncertainty caused the abatement efforts to shift from NPSs toward PSs. Moreover, the error transitivity from the WAC to conventional ETS approaches is more obvious than that to the WEFZ-based ETS. When NPSs emissions are relatively high, structural BMPs should be considered for trading, and vice versa. These results are critical to understand the impacts of uncertainty on the functionality of PS-NPS ETSs and to provide a trade-off between the confidence level and abatement efforts.

  13. Landscape planning for agricultural nonpoint source pollution reduction III: assessing phosphorus and sediment reduction potential.

    Science.gov (United States)

    Diebel, Matthew W; Maxted, Jeffrey T; Robertson, Dale M; Han, Seungbong; Vander Zanden, M Jake

    2009-01-01

    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 km(2)) 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.

  14. Uncertainty analysis for an effluent trading system in a typical nonpoint-sources-polluted watershed.

    Science.gov (United States)

    Chen, Lei; Han, Zhaoxing; Wang, Guobo; Shen, Zhenyao

    2016-07-11

    Conventional effluent trading systems (ETSs) between point sources (PSs) and nonpoint sources (NPSs) are often unreliable because of the uncertain characteristics of NPSs. In this study, a new framework was established for PS-NPS ETSs, and a comprehensive analysis was conducted by quantifying the impacts of the uncertainties associated with the water assimilative capacity (WAC), NPS emissions, and measurement effectiveness. On the basis of these results, the uncertain characteristics of NPSs would result in a less cost-effective PS-NPS ETS during most hydrological periods, and there exists a clear transition occurs from the WAC constraint to the water quality constraint if these stochastic factors are considered. Specifically, the emission uncertainty had a greater impact on PSs, but an increase in the emission or abatement uncertainty caused the abatement efforts to shift from NPSs toward PSs. Moreover, the error transitivity from the WAC to conventional ETS approaches is more obvious than that to the WEFZ-based ETS. When NPSs emissions are relatively high, structural BMPs should be considered for trading, and vice versa. These results are critical to understand the impacts of uncertainty on the functionality of PS-NPS ETSs and to provide a trade-off between the confidence level and abatement efforts.

  15. Mapping the scientific research on non-point source pollution: a bibliometric analysis.

    Science.gov (United States)

    Yang, Beibei; Huang, Kai; Sun, Dezhi; Zhang, Yue

    2017-02-01

    A bibliometric analysis was conducted to examine the progress and future research trends of non-point source (NPS) pollution during the years 1991-2015 based on the Science Citation Index Expanded (SCI-Expanded) of Web of Science (WoS). The publications referencing NPS pollution were analyzed including the following aspects: document type, publication language, publication output and characteristics, subject category, source journal, distribution of country and institution, author keywords, etc. The results indicate that the study of NPS pollution demonstrated a sharply increasing trend since 1991. Article and English were the most commonly used document type and language. Environmental sciences and ecology, water resources, and engineering were the top three subject categories. Water science and technology ranked first in distribution of journal, followed by Science of the total environment and Environmental Monitoring and Assessment. The USA took a leading position in both quantity and quality, playing an important role in the research field of NPS pollution, followed by the UK and China. The most productive institution was the Chinese Academy of Sciences (Chinese Acad Sci), followed by Beijing Normal University and US Department of Agriculture's Agricultural Research Service (USDA ARS). The analysis of author keywords indicates that the major hotspots of NPS pollution from 1991 to 2015 contained "water," "model," "agriculture," "nitrogen," "phosphorus," etc. The results provide a comprehensive understanding of NPS pollution research and help readers to establish the future research directions.

  16. 东江源山地果畜结合区面源污染生态化控制模式与效果分析%Study on ecological control mode of non-point source pollution from the system of orchard linked with animal husbandry in the valley of Dongjiang River Headwater

    Institute of Scientific and Technical Information of China (English)

    席运官; 刘明庆; 王磊; 汪贞; 李德波; 王宏燕

    2013-01-01

    The paper studied the structure and functions of pig-biogas-fruit-fish eco-agricultural mode in the headwater of Dongjiang River based on the Xinglin farm in Dingnan County, analyzed the controlling effect in quality and quantity to the water pollution nutrition through source controlling, drainage reducing and cleaning, and tested the draining water of Xinglin farm showing that draining water quality was better than the Ⅳ level standard of surface water. It proved that this model had the features of opearational, extentional and low input, and could be the important mode for controlling the non-point source pollution in the headwater of Dongjiang River.%  分析东江源山地果畜结合区“猪-沼-果-鱼”生态农业模式的结构与功能,定性和定量分析农庄采用生态化技术对水体污染物控源、减排、净化的效果,跟踪采样分析农庄排水水质,结果表明,农庄排水全年优于地表水Ⅳ类水标准,该模式兼具可操作、可推广、低投入特性,是东江源控制农业面源污染的重要模式。

  17. Search for the northwest passage: the assignation of NSP (non-point source pollution) rights in nutrient trading programs.

    Science.gov (United States)

    Collentine, D

    2002-01-01

    The search for solutions to the problem of non-point source pollution (NSP) includes alternatives based on theories associated with the use of tradable pollution permits. Tradable permit programs have received significant support as a promising policy for the reduction of effluent discharges but programs in practice have not been regarded as successful. The lack of success is ascribed to the design of the programs. However, this may be a design problem which is insurmountable due to the nature of the NSP problem. Tradable permit solutions are based on an assumption that the assignation of quantifiable rights to both point and nonpoint sources, based on some predetermined ambient water quality measure, is possible. The conclusion here is that there are significant features particular to NSP that hinder the introduction of rights and significantly decrease the utility of tradable permit solutions.

  18. Multi-angle Indicators System of Non-point Pollution Source Assessment in Rural Areas: A Case Study Near Taihu Lake

    Science.gov (United States)

    Huang, Lei; Ban, Jie; Han, Yu Ting; Yang, Jie; Bi, Jun

    2013-04-01

    This study aims to identify key environmental risk sources contributing to water eutrophication and to suggest certain risk management strategies for rural areas. The multi-angle indicators included in the risk source assessment system were non-point source pollution, deficient waste treatment, and public awareness of environmental risk, which combined psychometric paradigm methods, the contingent valuation method, and personal interviews to describe the environmental sensitivity of local residents. Total risk values of different villages near Taihu Lake were calculated in the case study, which resulted in a geographic risk map showing which village was the critical risk source of Taihu eutrophication. The increased application of phosphorus (P) and nitrogen (N), loss vulnerability of pollutant, and a lack of environmental risk awareness led to more serious non-point pollution, especially in rural China. Interesting results revealed by the quotient between the scores of objective risk sources and subjective risk sources showed what should be improved for each study village. More environmental investments, control of agricultural activities, and promotion of environmental education are critical considerations for rural environmental management. These findings are helpful for developing targeted and effective risk management strategies in rural areas.

  19. The non-point source (NPS) information system based on remote sensing and GIS and its preliminary application

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A non-point source information system (NPSIS) has been constructed by use of remote sensing and GIS technology, and a construction method of NPSlS introduced with Shenzhen as an example. With the remote sensing land-using images as an environment unit, the analysis modules based on NPSIS are built through combining the NPS model with NPSIS, and the preliminary NPS calculation and analysis performed.

  20. Landscape planning for agricultural non-point source pollution reduction. II. Balancing watershed size, number of watersheds, and implementation effort.

    Science.gov (United States)

    Maxted, Jeffrey T; Diebel, Matthew W; Vander Zanden, M Jake

    2009-01-01

    Agricultural non-point source (NPS) pollution poses a severe threat to water quality and aquatic ecosystems. In response, tremendous efforts have been directed toward reducing these pollution inputs by implementing agricultural conservation practices. Although conservation practices reduce pollution inputs from individual fields, scaling pollution control benefits up to the watershed level (i.e., improvements in stream water quality) has been a difficult challenge. This difficulty highlights the need for NPS reduction programs that focus efforts within target watersheds and at specific locations within target watersheds, with the ultimate goal of improving stream water quality. Fundamental program design features for NPS control programs--i.e., number of watersheds in the program, total watershed area, and level of effort expended within watersheds--have not been considered in any sort of formal analysis. Here, we present an optimization model that explores the programmatic and environmental trade-offs between these design choices. Across a series of annual program budgets ranging from $2 to $200 million, the optimal number of watersheds ranged from 3 to 27; optimal watershed area ranged from 29 to 214 km(2); and optimal expenditure ranged from $21,000 to $35,000/km(2). The optimal program configuration was highly dependent on total program budget. Based on our general findings, we delineated hydrologically complete and spatially independent watersheds ranging in area from 20 to 100 km(2). These watersheds are designed to serve as implementation units for a targeted NPS pollution control program currently being developed in Wisconsin.

  1. Regional-scale assessment of non-point source groundwater contamination

    Science.gov (United States)

    Loague, Keith; Corwin, Dennis L.

    1998-05-01

    Predictive assessments of non-point source (NPS) pollution can have great utility for environmentally focused land use decisions related to both the remediation of existing groundwater contamination and the regulation of current (and future) agrochemical use. At the regional scales associated with NPS agrochemical applications there are staggering data management problems in assessing potential groundwater vulnerability. Geographical information system (GIS) technology is a timely tool that greatly facilitates the organized characterization of regional-scale variability. In this paper we review the recently reported (Loague et al., 1998a,b) simulations of NPS groundwater vulnerability, resulting from historical applications of the agrochemical DBCP (1,2-dibromo-3-chloropropane), for east-central Fresno County (California). The Fresno case study helps to illustrate the data requirements associated with process-based three-dimensional simulations of coupled fluid flow and solute transport in the unsaturated/saturated subsurface at a regional scale. The strengths and weaknesses of using GIS in regional-scale vulnerability assessments, such as the Fresno case study, and the critical problem of estimating the uncertainties in these assessments (owing to both data and model errors) are discussed. A regional GIS-driven integrated assessment approach is proposed, which is based upon cost-benefit analysis, and incorporates both physical and economic factors that can be used in a regulatory decision process.

  2. Landscape Based Modeling of Nonpoint Source Nitrogen Loading in the Neuse River Basin, North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Garten, C.T.

    2001-01-11

    The objective of this research was to arrive at a quantitative and qualitative assessment of nonpoint sources of potential excess N under different land use/land cover (LULC) categories in the Neuse River Basin on a seasonal time scale. This assessment is being supplied to EPA's Landscape Characterization Branch, National Exposure Research Laboratory, in Research Triangle Park, NC, for inclusion in a hydrologic model to predict seasonal fluxes of N from the terrestrial landscape to surface receiving waters and groundwater in the Neuse River Basin. The analysis was performed in the following five steps: (1) development of a conceptual model to predict potential excess N on land, (2) a literature review to parameterize N fluxes under LULC categories found in the Neuse River Basin, (3) acquisition of high resolution (15-m pixel) LULC data from EPA's Landscape Characterization Branch, National Exposure Research Laboratory, in Research Triangle Park, NC, (4) acquisition of a soil N inventory map for the Neuse River Basin, (5) calculations of potential excess N on a seasonal basis for the entire Neuse River Basin.

  3. Pollution of surface waters by metalaxyl and nitrate from non-point sources.

    Science.gov (United States)

    Bermúdez-Couso, Alipio; Fernández-Calviño, David; Álvarez-Enjo, Manuel Ali; Simal-Gándara, Jesús; Nóvoa-Muñoz, Juan Carlos; Arias-Estévez, Manuel

    2013-09-01

    The mobility of contaminants in soil is highly dependent upon the characteristics of the contaminant chemical and the properties of the soil. In order to explore these relationships, the district of A Limia (Galicia, NW Spain) was selected as the study area--a cropland devoted to growing potatoes, where the soil had been managed intensively over the last 50 years. The soil was characterised by low slopes with the water table located very close to the soil surface. Our aim was to study the influence of high and intensive crop production on the water bodies and non-point source contamination, with a particular focus on metalaxyl and nitrate. The highest concentrations of metalaxyl occurred when rainfalls were low and in zones of the study area where natural hydrology was significantly altered by numerous drainage canals. The spatial and temporal distributions of the nitrate also showed a high variability, with the interaction between seasons and sampling area being the most significant factor in explaining the levels found. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Introduction: Assessing non-point source pollution in the vadose zone with advanced information technologies

    Science.gov (United States)

    Corwin, Dennis L.; Loague, Keith; Ellsworth, Timothy R.

    The information age has ushered in a global awareness of complex environmental problems that do not respect political or physical boundaries: climatic change, ozone layer depletion, deforestation, desertification, and non-point source (NPS) pollution. Among these global environmental problems, NPS pollutants represent a perfect example of a complex multidisciplinary problem that exists over multiple scales with tremendous spatial and temporal complexity. To address the NPS problem, specific to the vadose zone, advanced information technologies must be applied in a spatial context. An integrated system of advanced information technologies (i.e., global positioning, geographic information system, geostatistics, remote sensing, solute transport modeling, neural networks, transfer functions, fuzzy logic, hierarchical theory, and uncertainty analysis) provides a framework from which real-time and/or simulated assessments of NPS pollution can be made. The ability to accurately assess present and future NPS-pollution impacts on ecosystems ranging from local to global scales provides a powerful tool for environmental stewardship and guiding future human activities.

  5. Using site-specific soil samples as a substitution for improved hydrological and nonpoint source predictions.

    Science.gov (United States)

    Chen, Lei; Wang, Guobo; Zhong, Yucen; Zhao, Xin; Shen, Zhenyao

    2016-08-01

    Soil databases are one of the most important inputs for watershed models, and the quality of soil properties affects how well a model performs. The objectives of this study were to (1) quantify the sensitivity of model outputs to soil properties and to (2) use site-specific soil properties as a substitution for more accurate hydrological and nonpoint source (H/NPS) predictions. Soil samples were collected from a typical mountainous watershed in China, and the impacts of soil sample parameters on H/NPS predictions were quantified using the Soil and Water Assessment Tool (SWAT). The most sensitive parameters related to predicting flow, sediment, and total phosphorus (TP) mainly were the soil hydrological, the channel erosion processes, and the initial soil chemical environment, respectively. When the site-specific soil properties were used, the uncertainties (coefficient of variation) related to predicting the hydrology, sediment and TP decreased by 75∼80 %, 75∼84 %, and 46∼61 %, respectively. Based on changes in the Nash-Sutcliff coefficient, the model performance improved by 4.9 and 19.45 % for the hydrological and sediment model, accordingly. However, site-specific soil properties did not contribute to better TP predictions because of the high spatial variability of the soil P concentrations across the large watershed. Thus, although site-specific soil samples can be used to obtain more accurate H/NPS predictions, more sampling sites are required to apply this method in large watersheds.

  6. Evaluating the impacts of soil data on hydrological and nonpoint source pollution prediction.

    Science.gov (United States)

    Chen, Lei; Wang, Guobo; Zhong, Yucen; Shen, Zhenyao

    2016-09-01

    Soil data are one key input for most hydrological and nonpoint source (H/NPS) models, and quantifying the error transmission from soil data to H/NPS predictions is of great importance. In this study, two typical soil datasets were compared using the Soil and Water Assessment Tool (SWAT) in a typical mountainous watershed, the Three Gorges Reservoir Region, China. Besides, the effects of soil data resolution were evaluated, and the error transmission from soil data to watershed management strategy was assessed. The results indicate that model outputs are not sensitive to changes of soil data resolution but the choice of soil data greatly impacts the application of watershed models, in terms of the goodness-of-fit indicator, predicted data and related uncertainty. This soil data-induced error would be inevitably magnified from the flow simulation to the NPS prediction stage. This study could indicate that the choice of soil data will lead to significant differences in management schemes for specific pollution periods. These results provide information on the impacts of soil data on the functionality of watershed models and valuable information for the appropriateness of each soil database.

  7. Development of type transfer functions for regional-scale nonpoint source groundwater vulnerability assessments

    Science.gov (United States)

    Stewart, Iris T.; Loague, Keith

    2003-12-01

    Groundwater vulnerability assessments of nonpoint source agrochemical contamination at regional scales are either qualitative in nature or require prohibitively costly computational efforts. By contrast, the type transfer function (TTF) modeling approach for vadose zone pesticide leaching presented here estimates solute concentrations at a depth of interest, only uses available soil survey, climatic, and irrigation information, and requires minimal computational cost for application. TTFs are soil texture based travel time probability density functions that describe a characteristic leaching behavior for soil profiles with similar soil hydraulic properties. Seven sets of TTFs, representing different levels of upscaling, were developed for six loam soil textural classes with the aid of simulated breakthrough curves from synthetic data sets. For each TTF set, TTFs were determined from a group or subgroup of breakthrough curves for each soil texture by identifying the effective parameters of the function that described the average leaching behavior of the group. The grouping of the breakthrough curves was based on the TTF index, a measure of the magnitude of the peak concentration, the peak arrival time, and the concentration spread. Comparison to process-based simulations show that the TTFs perform well with respect to mass balance, concentration magnitude, and the timing of concentration peaks. Sets of TTFs based on individual soil textures perform better for all the evaluation criteria than sets that span all textures. As prediction accuracy and computational cost increase with the number of TTFs in a set, the selection of a TTF set is determined by a given application.

  8. A distributed non-point source pollution model: calibration and validation in the Yellow River Basin.

    Science.gov (United States)

    Hao, Fang-hua; Zhang, Xue-song; Yang, Zhi-feng

    2004-01-01

    The applicability of a non-point source pollution model--SWAT(soil and water assessment tools) in a large river basin with high sediment runoff modulus(770 t/km2 in the Yellow River) was examined. The basic database, which includes DEM, soil and landuse map, weather data, and land management data, was established for the study area using GIS. A two-stage "Brute Force" optimization method was used to calibrate the parameters with the observed monthly flow and sediment data from 1992 to 1997. In the process of calibration automated digital filter technique was used to separate direct runoff and base flow. The direct runoff was firstly calibrated, and the base flow, then the total runoff was matched. The sediment yield was calibrated to match well. Keeping input parameters set during the calibration process unchanged, the model was validated with 1998--1999's observed monthly flow and sediment. The evaluation coefficients for simulated and observed flow and sediment showed that SWAT was successfully applied in the study area: relative error was within 20%, coefficient of determination and Nash-Suttcliffe simulation efficiency were all equal to or above 0.70 during calibration and validation period.

  9. Reducing Nonpoint Source Pollution Through Collaboration: Policies and Programs Across the U.S. States

    Science.gov (United States)

    Hardy, Scott D.; Koontz, Tomas M.

    2008-03-01

    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.

  10. Model AVSWAT apropos of simulating non-point source pollution in Taihu lake basin.

    Science.gov (United States)

    Zhang, Qiu-Ling; Chen, Ying-Xu; Jilani, Ghulam; Shamsi, Imran Haider; Yu, Qiao-Gang

    2010-02-15

    Accelerated eutrophication and nutrient loads in the lakes are of major concern for human health and environment. This study was undertaken for modeling the non-point source pollution of Taihu lake basin in eastern China. The SWAT model having an interface in ArcView GIS was employed. Model sensitive parameters related to hydrology and water quality were obtained by sensitivity analysis, and then calibrated and validated by comparing model predictions with field data. The GIS showed good potential for parameterization of hill-slopes, channels, and representative slope profiles for SWAT model simulations. In a monthly and daily time step, the model's Nash-Sutcliffe coefficient (E) and the coefficient of determination (R(2)) indicated that values of simulated runoff, NH(4)(+)-N and total phosphorus were acceptably closer to the measured data. Surface water parameters especially CN, Soil-AWC and ESCO were the most sensitive and had more recognition in the model. It is concluded that runoff carrying N and P nutrients from chemical fertilizer inputs in agricultural areas is the major contributor to NPSP in the lake basin. So, decrease in excessive use of N and P fertilizers and their synergism with organic manures is recommended that would significantly reduce nutrient pollution in the lake ecosystem.

  11. Governing change: land-use change and the prevention of nonpoint source pollution in the north coastal basin of California.

    Science.gov (United States)

    Short, Anne G

    2013-01-01

    Many rural areas in the United States and throughout much of the postindustrial world are undergoing significant ecological, socioeconomic, and political transformations. The migration of urban and suburban dwellers into rural areas has led to the subdivision of large tracts of land into smaller parcels, which can complicate efforts to govern human-environmental problems. Non-point source (NPS) pollution from private rural lands is a particularly pressing human-environmental challenge that may be aggravated by changing land tenure. In this article, I report on a study of the governance and management of sediment (a common NPS pollutant) in the North Coastal basin of California, a region undergoing a transition from traditional extractive and agricultural land uses to rural residential and other alternative land uses. I focus on the differences in the governance and management across private timber, ranch, residential, vacation, and other lands in the region. I find that (1) the stringency and strength of sediment regulations differ by land use, (2) nonregulatory programs tend to target working landscapes, and (3) rural residential landowners have less knowledge of sediment control and report using fewer sediment-control techniques than landowners using their land for timber production or ranching. I conclude with an exploration of the consequences of these differences on an evolving rural landscape.

  12. 农业面源污染治理的政策效用评估以江苏省海安县的测土配方施肥推广为例%Agricultural Non-point Source Pollution Controlling Policy's Utility Evaluation Based on Environmental Cost:A Case Study of Soil Testing and Fertilizer Recommendation Technology in Hai'an County

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    为衡量农业面源污染治理政策的作用效果,文章基于环境成本的视角,探索了农业面源污染治理政策效用评估的一般方法与步骤。首先,结合农业化肥的环境污染特点,利用输出系数模型以实现对区域内农业化肥造成的总氮TN、总磷TP排放量的合理测算。然后,建立了基于能值分析法的环境成本估计模型,并结合经济成本和经济收益,构建了基于成本-收益分析的农业面源污染治理政策效用评估的一般模型。最后,以江苏省海安县的测土配方施肥技术的推广为例,对海安县测土配方施肥节本增收效果进行综合评价,并探索了江苏省实现测土配方施肥全覆盖时的总体效果,为面源污染治理政策的评估提供思路。%In order to assess the policy effect of controlling agricultural non-point source pollution ,this paper ,based on the perspec‐tive of environmental cost ,explores the general methods and steps for utility evaluation of agricultural non-point source pollution's treatment measures .First of all ,combined with the characteristics of environmental pollution caused by agricultural fertilizer ,this paper chooses a rational export coefficient model to calculate total nitrogen (TN) ,total phosphorus (TP) emissions caused by agri‐cultural fertilizer in the region .Then ,targeted at soil testing and fertilizer recommendation technology ,this paper constructs envi‐ronmental cost estimation model based on energy analysis and general utility evaluation model based on cost-benefit analysis .Finally , this paper takes Hai'an County's promotion of soil testing and fertilizer recommendation in Jiangsu Province for example ,the synthe‐sized evaluation of the technology is achieved in saving costs and increasing income .Further ,this paper explores the beneficial se‐quence when the technology is spread to the whole Jiangsu Province ,which will provide ways to better choose

  13. Severe situation of rural nonpoint source pollution and efficient utilization of agricultural wastes in the Three Gorges Reservoir Area.

    Science.gov (United States)

    Zhang, Tong; Ni, Jiupai; Xie, Deti

    2015-11-01

    Rural nonpoint source (NPS) pollution caused by agricultural wastes has become increasingly serious in the Three Gorges Reservoir Area (TGRA), significantly affecting the reservoir water quality. The grim situation of rural NPS pollution in the TGRA indicated that agrochemicals (chemical fertilizer and pesticide) were currently the highest contributor of rural NPS pollution (50.38%). The harmless disposal rates of livestock excrement, crop straws, rural domestic refuse, and sewage also cause severe water pollution. More importantly, the backward agricultural economy and the poor environmental awareness of farmers in the hinterland of the TGRA contribute to high levels of rural NPS pollution. Over the past decade, researchers and the local people have carried out various successful studies and practices to realize the effective control of rural NPS pollution by efficiently utilizing agricultural wastes in the TGRA, including agricultural waste biogas-oriented utilization, crop straw gasification, decentralized land treatment of livestock excrement technology, and crop straw modification. These technologies have greatly increased the renewable resource utilization of agricultural wastes and improved water quality and ecological environment in the TGRA.

  14. ASSESSMENT AND CONTROL OF NITROGEN EMISSION FROM AGRICULTURAL NON-POINT SOURCE IN THE URBAN AGGLOMERATION IN THE MIDDLE-LOWER YANGTZE RIVER BELT%长江中下游城市群农业面源污染氮排放评价及调控

    Institute of Scientific and Technical Information of China (English)

    赖敏; 王伟力; 郭灵辉

    2016-01-01

    Nitrogen is an important component of protein and essential element for the growth of aquatic biomass. Excessive nitrogen input to natural water bodies leads to huge ecological pressure and environmental pollutions such as eutrophication. As point source pollution got effective control in the socio-economic system, agricultural non-point source pollution has become the main cause of eutrophication. Quantifying and regulating the agricultural non-point source pollution emissions throughout the entire socio-economic system is crucial to mitigate or avoid pro-ducing water pollution. Based on the inventory analysis method and emission coefficient method, this paper calcu-lated the nitrogen emission from the agricultural non-point source for the Urban Agglomeration in the Middle-Lower Yangtze River Belt. The results showed that the total nitrogen emission from the agricultural non -point source in the whole area was 128. 27 × 104 t in 2011, of which agricultural emission accounted for 58. 92%, and e-mission from livestock and poultry was 33 . 53%. The sensitivity analysis method and scenario analysis method were then applied to simulate the emission situation during 2011 to 2020 and 2020 to 2030 . Some conclusions were drawn as follows:Under scenario 1, if more stringent pollution control efforts were not implemented, the nitrogen e-mission from the agricultural non-point source would increase 16 . 29% during 2011 to 2020 , and 18 . 78% during 2020 to 2030. Under scenario 2 and scenario 3, by contrast, the total nitrogen emission of the four urban agglomer-ations would be 15% fewer in 2020 than in 2011 , and 25% fewer in 2030 than in 2011 . The nitrogen emission re-duction effect in scenario 2 was better than that in scenario 3;Scenario 3 was considered to be more conducive to couple the relationship between regional economic growth and environmental protection. Finally, some recommen-dations were put forward to regional emission reduction, including reducing

  15. Relationship Between Non-Point Source Pollution and Korean Green Factor

    Directory of Open Access Journals (Sweden)

    Seung Chul Lee

    2015-01-01

    Full Text Available In determining the relationship between the rational event mean concentration (REMC which is a volume-weighted mean of event mean concentrations (EMCs as a non-point source (NPS pollution indicator and the green factor (GF as a low impact development (LID land use planning indicator, we constructed at runoff database containing 1483 rainfall events collected from 107 different experimental catchments from 19 references in Korea. The collected data showed that EMCs were not correlated with storm factors whereas they showed significant differences according to the land use types. The calculated REMCs for BOD, COD, TSS, TN, and TP showed negative correlations with the GFs. However, even though the GFs of the agricultural area were concentrated in values of 80 like the green areas, the REMCs for TSS, TN, and TP were especially high. There were few differences in REMC runoff characteristics according to the GFs such as recreational facilities areas in suburbs and highways and trunk roads that connect to major roads between major cities. Except for those areas, the REMCs for BOD and COD were significantly related to the GFs. The REMCs for BOD and COD decreased when the rate of natural green area increased. On the other hand, some of the REMCs for TSS, TN, and TP were still high where the catchments encountered mixed land use patterns, especially public facility areas with bare ground and artificial grassland areas. The GF could therefore be used as a major planning indicator when establishing land use planning aimed at sustainable development with NPS management in urban areas if the weighted GF values will be improved.

  16. Assessing the effects of non-point source pollution on American Samoa's coral reef communities.

    Science.gov (United States)

    Houk, Peter; Didonato, Guy; Iguel, John; Van Woesik, Robert

    2005-08-01

    Surveys were completed on Tutuila Island, American Samoa, to characterize reef development and assess the impacts of non-point source pollution on adjacent coral reefs at six sites. Multivariate analyses of benthic and coral community data found similar modern reef development at three locations; Aoa, Alofau, and Leone. These sites are situated in isolated bays with gentle sloping foundations. Aoa reefs had the highest estimates of crustose coralline algae cover and coral species richness, while Leone and Alofau showed high abundances of macroalgae and Porites corals. Aoa has the largest reef flat between watershed discharge and the reef slope, and the lowest human population density. Masefau and Fagaalu have a different geomorphology consisting of cemented staghorn coral fragments and steep slopes, however, benthic and coral communities were not similar. Benthic data suggest Fagaalu is heavily impacted compared with all other sites. Reef communities were assessed as bio-criteria indicators for waterbody health, using the EPA aquatic life use support designations of (1) fully supportive, (2) partially supportive, and (3) non-supportive for aquatic life. All sites resulted in a partially supportive ranking except Fagaalu, which was non-supportive. The results of this rapid assessment based upon relative benthic community measures are less desirable than long-term dataset analyses from monitoring programs, however it fills an important role for regulatory agencies required to report annual waterbody assessments. Future monitoring sites should be established to increase the number of replicates within each geological and physical setting to allow for meaningful comparisons along a gradient of hypothesized pollution levels.

  17. Estimating the susceptibility of surface water in Texas to nonpoint-source contamination by use of logistic regression modeling

    Science.gov (United States)

    Battaglin, William A.; Ulery, Randy L.; Winterstein, Thomas; Welborn, Toby

    2003-01-01

    In the State of Texas, surface water (streams, canals, and reservoirs) and ground water are used as sources of public water supply. Surface-water sources of public water supply are susceptible to contamination from point and nonpoint sources. To help protect sources of drinking water and to aid water managers in designing protective yet cost-effective and risk-mitigated monitoring strategies, the Texas Commission on Environmental Quality and the U.S. Geological Survey developed procedures to assess the susceptibility of public water-supply source waters in Texas to the occurrence of 227 contaminants. One component of the assessments is the determination of susceptibility of surface-water sources to nonpoint-source contamination. To accomplish this, water-quality data at 323 monitoring sites were matched with geographic information system-derived watershed- characteristic data for the watersheds upstream from the sites. Logistic regression models then were developed to estimate the probability that a particular contaminant will exceed a threshold concentration specified by the Texas Commission on Environmental Quality. Logistic regression models were developed for 63 of the 227 contaminants. Of the remaining contaminants, 106 were not modeled because monitoring data were available at less than 10 percent of the monitoring sites; 29 were not modeled because there were less than 15 percent detections of the contaminant in the monitoring data; 27 were not modeled because of the lack of any monitoring data; and 2 were not modeled because threshold values were not specified.

  18. Controlled-release fertilizer(CRF):A green fertilizer for controlling non-point contamination in agriculture

    Institute of Scientific and Technical Information of China (English)

    MAO Xiao-yun; SUN Ke-jun; WANG De-han; LIAO Zong-wen

    2005-01-01

    Fertilizers contribute greatly to high yields but also result in environmental non-point contamination, including the emission of greenhouse gas(N2O) and eutrophication of water bodies. How to solve this problem has become a serious challenge, especially for China as its high ecological pressure. Controlled-release fertilizer(CRF) has been developed to minimize the contamination while keeping high yield and has become a green fertilizer for agriculture. Several CRFs made with special coating technology were used for testing the fertilizer effects in yield and environment through pot experiment and field trial. The result indicated that the CRFs had higher N use efficiency, thus reducing N loss through leaching and volatilization while keeping higher yields. Comparing with imported standard CRFs,the test on CRFs showed similar fertilizer effect but with much lower cost. CRFs application is becoming a new approach for minimizing non-point contamination in agriculture.

  19. [Bivariate statistical model for calculating phosphorus input loads to the river from point and nonpoint sources].

    Science.gov (United States)

    Chen, Ding-Jiang; Sun, Si-Yang; Jia, Ying-Na; Chen, Jia-Bo; Lü, Jun

    2013-01-01

    Based on the hydrological difference between the point source (PS) and nonpoint source (NPS) pollution processes and the major influencing mechanism of in-stream retention processes, a bivariate statistical model was developed for relating river phosphorus load to river water flow rate and temperature. Using the calibrated and validated four model coefficients from in-stream monitoring data, monthly phosphorus input loads to the river from PS and NPS can be easily determined by the model. Compared to current hydrologica methods, this model takes the in-stream retention process and the upstream inflow term into consideration; thus it improves the knowledge on phosphorus pollution processes and can meet the requirements of both the district-based and watershed-based wate quality management patterns. Using this model, total phosphorus (TP) input load to the Changle River in Zhejiang Province was calculated. Results indicated that annual total TP input load was (54.6 +/- 11.9) t x a(-1) in 2004-2009, with upstream water inflow, PS and NPS contributing to 5% +/- 1%, 12% +/- 3% and 83% +/- 3%, respectively. The cumulative NPS TP input load during the high flow periods (i. e. , June, July, August and September) in summer accounted for 50% +/- 9% of the annual amount, increasing the alga blooming risk in downstream water bodies. Annual in-stream TP retention load was (4.5 +/- 0.1) t x a(-1) and occupied 9% +/- 2% of the total input load. The cumulative in-stream TP retention load during the summer periods (i. e. , June-September) accounted for 55% +/- 2% of the annual amount, indicating that in-stream retention function plays an important role in seasonal TP transport and transformation processes. This bivariate statistical model only requires commonly available in-stream monitoring data (i. e. , river phosphorus load, water flow rate and temperature) with no requirement of special software knowledge; thus it offers researchers an managers with a cost-effective tool for

  20. Advances on agricultural non-point source pollution and the control in regions around Hung-tse Lake%环洪泽湖区域农业面源污染特征及控制对策

    Institute of Scientific and Technical Information of China (English)

    徐勇峰; 陈子鹏; 吴翼; 朱咏莉; 李萍萍

    2016-01-01

    Hung⁃tse Lake, located in the northwest of Jiangsu Province, is the fourth largest freshwater lake in China. It is also one of the key hinge lakes in the east route of the south⁃to⁃north water transfer project. However, the water quality for the lake was worse than grade Ⅴ according to the Environmental Quality Standard of Surface Water of the People�s Republic of China. Non⁃point source pollution around the lake was considered one of the main reasons. In the present study, the feature, sources, inducement, control and management of agricultural non⁃point pollution around the lake were reviewed. We held that the unreasonable application of chemical fertilizer was the largest source of the pollution. Aquaculture pollution was substantially increasing due to the facts of the ineffective management to enclosure culture and the abuse of exogenous diets. In addition, the emissions of livestock and poultry breeding, rural sewage and unordered waste management were the main contributors of the pollution. Therefore, the control strategies for the agricultural non⁃point source pollution in the regions should focused on ① developing ecological agriculture with reasonable applications of fertilizer and pesticides,②integrating and optimizing the aquaculture,③improving the treatment of rural sewage and recycling of agricultural wastes,④ reducing pollution by enhancing the land use among farmlands, woodlands and wet⁃lands.%洪泽湖是位于江苏省西北部的我国第四大淡水湖泊,同时是南水北调东线工程的重要节点湖泊。然而,目前洪泽湖水质总体状况仍呈下降趋势,其中面源污染是重要原因之一。笔者对环洪泽湖地区农业面源污染的特点、来源与诱因以及控制技术等进行系统评述,分析认为:不合理的化肥施用是该区域第一大面源污染来源;围网养殖区无序规划及大量外源性饵料的投加,使得水产养殖的污染排放呈现增加趋

  1. Modelling of point and non-point source pollution of nitrate with SWAT in the river Dill, Germany

    OpenAIRE

    T. Pohlert; J. A. Huisman; L. Breuer; Frede, H.-G.

    2005-01-01

    International audience; We used the Soil and Water Assessment Tool (SWAT) to simulate point and non-point source pollution of nitrate in a mesoscale mountainous catchment. The results show that the model efficiency for daily discharge is 0.81 for the calibration period (November 1990 to December 1993) and 0.56 for the validation period (April 2000 to January 2003). The model efficiency for monthly nitrate load is 0.66 and 0.77 for the calibration period (April 2000 to March 2002) and validati...

  2. Evaluation of nonpoint-source contamination, Wisconsin: Land-use and Best-Management-Practices inventory, selected streamwater-quality data, urban-watershed quality assurance and quality control, constituent loads in rural streams, and snowmelt-runoff analysis, water year 1994

    Science.gov (United States)

    Walker, J.F.; Graczyk, D.J.; Corsi, S.R.; Owens, D.W.; Wierl, J.A.

    1995-01-01

    The objective of the watershed-management evaluation monitoring program in Wisconsin is to evaluate the effectiveness of best-management practices (BMP) for controlling nonpoint-source contamination in rural and urban watersheds. This report is an annual summary of the data collected for the program by the U.S Geological Survey and a report of the results of several different detailed analyses of the data. A land-use and BMP inventory is ongoing for 12 evaluation monitoring projects to track the sources of nonpoint-source pollution in each watershed and to document implementation of BMP's that may cause changes in the water quality of streams. Updated information is gathered each year, mapped, and stored in a geographic-information-system data base. Summaries of data collected during water years 1989-94 are presented. A water year is the period beginning October 1 and ending September 30; the water year is designated by the calendar year in which it ends. Suspended-sediment and total-phosphorus data (storm loads and annual loads) are summarized for eight rural sites. For all sites, the annual suspended-sediment or suspended-solids load for water year 1993 exceeded the average for the period of data collection; the minimum annual loads were transported in water year 1991 or 1992. Continuous dissolved-oxygen data were collected at seven rural sites during water year 1994. Data for water years 1990-93 are summarized and plotted in terms of percentage of time that a particular concentration is equaled or exceeded. Dissolved-oxygen concentrations in four streams were less than 9 mg/L at least 50 percent of the time, a condition that fails to meet suggested criterion for coldwater streams. The dissolved-oxygen probability curve for one of the coldwater streams is markedly different than the curves for the other streams, perhaps because of differences in aquatic biomass. Blank quality-assurance samples were collected at two of the urban evaluation monitoring sites to

  3. Agricultural Non-point Source Pollution and Countermeasures in Yunnan%云南省农业面源污染及防治对策

    Institute of Scientific and Technical Information of China (English)

    邱成

    2014-01-01

    云南省主要农业环境污染问题包括:化肥使用量不断增加;地膜使用量及其覆盖面积不断增加;农药使用量不断增加;畜禽粪便污染日益加重。分析了问题产生的原因,提出了防治农业污染的建议。%Environmental problems are emerging due to agricultural non -point source pollution in Yunnan.The most serious problems are as follows:an increasing usage of chemical fertilizers and plastics in farm field,a rising release of pesticide,and a growing amount of waste from livestock and poultry.Agricultural non-point sources in Yunnan were identified.Suggestions were put forward to control agricultural pollution.

  4. 非点源污染负荷模型的研究进展%Research Progress of Non-point Source Pollution Models in Water Environment

    Institute of Scientific and Technical Information of China (English)

    姚瑞华; 王东; 赵越; 张晶

    2012-01-01

    Based on non-point source load model research at home and abroad, in accordance of the agriculture, urban and mixed non-point source models, the main conditions for the application model were summarized, and the development of non-point source model was prospected.%基于国内外非点源负荷污染模型的研究现状,针对农业、城市和混合三种类型非点源模型,总结并梳理了主要模型的适用条件,并对非点源模型的发展趋势进行了展望.

  5. The Non-point Source Pollution Effects of Pesticides Based on the Survey of 340 Farmers in Chongqing City

    Institute of Scientific and Technical Information of China (English)

    Lianchao; YU; Limeng; GU; Qian; BI

    2015-01-01

    Using the survey data on 340 farmers in Chongqing City,this paper performs an empirical analysis of the factors influencing the non-point source pollution of pesticides. The results show that the older householders will apply more pesticides,which may be due to the weak physical strength and weak ability to accept the concept of advanced cultivation; the householders with high level of education will choose to use less pesticides; the pesticide application rate is negatively correlated with whether farmers have participated in agricultural technology training,that is,the farmers having participated in agricultural technology training have stronger ability to scientifically apply pesticides,and in-depth understanding of advanced agricultural production technology and positive and negative effects of pesticides,so they often choose to reduce the application rate of pesticide; the cognitive factor on the role of pesticides in better promoting the growth of crops is significant,which requires the government and relevant departments to carry out concrete publicity of effectiveness and negative impact of different pesticides during the popularization of agricultural science knowledge,to prompt farmers to have a systematic and in-depth understanding of the agricultural nonpoint source pollution caused by pesticides.

  6. Analysis of Nonpoint Source Pollution and Water Environmental Quality Variation Trends in the Nansi Lake Basin from 2002 to 2012

    Directory of Open Access Journals (Sweden)

    Weiliang Wang

    2015-01-01

    Full Text Available Based on the data analysis of economic development and the water environmental quality from 2002 to 2012 in the Nansi Lake Basin in China, the correlation between economic development and the water environmental quality was researched. Analysis shows that the GDP of the Nansi Lake Basin had an average annual growth of 7.3% in 2012, and the COD and CODMn had the average annual decrease of 7.69% and 6.79%, respectively, compared to 2002. Basin water environmental quality overall improved, reaching Class III of the “Environmental quality standards for surface water (GB3838-2002.” The pollution of the water environment was analyzed from three aspects: agricultural fertilizers and pesticides, livestock, and aquaculture. Results indicated that the water pollution of the Nansi Lake Basin mainly came from nonpoint source pollution, accounting for more than 80% of the overall pollution. The contributions of both agricultural fertilizers and pesticides account for more than 85% of the overall nonpoint source, followed by livestock and aquaculture. According to the water pollution characteristics of the Nansi Lake Basin, the basin pollution treatment strategy and prevention and treatment system were dissected, to solve the pollution problem of the Nansi Lake Basin.

  7. Spatial Distribution Pattern of Agricultural Non-point Source Pollution in Jiangxi Province%江西省农业面源污染空间分布格局

    Institute of Scientific and Technical Information of China (English)

    张文东; 许仕; 庐俊

    2012-01-01

    The agricultural non-point source pollution is becoming an increasingly important eco-envjonrmental problem, il is difficult lo control due lo its dispersive and extensive characteristics. Jiangxi Province is still at ihe initial stage ai agricultural modernization, bul its agricultural non-point source pollution is exacerbating. According to the investigation on the pollution sources of planting, animal husbandry and aq-uaculture in Jiangs i Province, the ArcGIS software was adopted to analyze the spatial and digital features of agricultural non-point source pollution. As indicated by the results, the principal pollution source is animal husbandry, then followed by planting, ihe pollution from aquarulture is becoming more and more serious. The study provided scientific basis for the evaluation of agricultural non-point source pollution in Jiangxi Province.%农业面源污染正成为生态环境的主要问题,但其分散性、广泛性等特点又决定了其治理难度较大.江西目前仍处于农业现代化的起点阶段,农业面源污染日益严重:该研究通过对江西省农业的种植业、畜禽业和水产养殖业的污染源进行调查,利用ArcGIS软件,对江西省农业面源污染进行了空间化和数字化处理.结果表明,江西省农业污染源主要是畜禽养殖业,其次是种植业,水产养殖业污染日趋严重.该研究为江西省农业面源污染评估提供了科学依据.

  8. Modelling of point and non-point source pollution of nitrate with SWAT in the river Dill, Germany

    Directory of Open Access Journals (Sweden)

    T. Pohlert

    2005-01-01

    Full Text Available We used the Soil and Water Assessment Tool (SWAT to simulate point and non-point source pollution of nitrate in a mesoscale mountainous catchment. The results show that the model efficiency for daily discharge is 0.81 for the calibration period (November 1990 to December 1993 and 0.56 for the validation period (April 2000 to January 2003. The model efficiency for monthly nitrate load is 0.66 and 0.77 for the calibration period (April 2000 to March 2002 and validation period (April 2002 to January 2003, respectively. However, the model efficiency for daily loads is low (0.15, which cannot only be attributed to the quality of input data of point source effluents. An analysis of the internal fluxes and cycles of nitrogen pointed out considerable weaknesses in the models conceptualisation of the nitrogen modules which will be improved in future research.

  9. Assessment of Non-Point Source Total Phosphorus Pollution from Different Land Use and Soil Types in a Mid-High Latitude Region of China

    Directory of Open Access Journals (Sweden)

    Zhiwei Wang

    2016-11-01

    cultivated land. This has important implications for future agricultural management and non-point source control in this agricultural area of the mid-high latitude region.

  10. A West Virginia case study: does erosion differ between streambanks clustered by the bank assessment of nonpoint source consequences of sediment (BANCS) model parameters?

    Science.gov (United States)

    Abby L. McQueen; Nicolas P. Zegre; Danny L. Welsch

    2013-01-01

    The integration of factors and processes responsible for streambank erosion is complex. To explore the influence of physical variables on streambank erosion, parameters for the bank assessment of nonpoint source consequences of sediment (BANCS) model were collected on a 1-km reach of Horseshoe Run in Tucker County, West Virginia. Cluster analysis was used to establish...

  11. The impact of information on behavior under an ambient-based policy for regulating nonpoint source pollution

    Science.gov (United States)

    Miao, Haoran; Fooks, Jacob R.; Guilfoos, Todd; Messer, Kent D.; Pradhanang, Soni M.; Suter, Jordan F.; Trandafir, Simona; Uchida, Emi

    2016-05-01

    Stemming from Segerson [1988], literature on nonpoint source pollution shows that ambient-based regulatory policies can induce polluters in a common watershed to comply with an exogenously determined pollution standard. This study uses laboratory economic experiments in a spatially heterogeneous setting to test the effectiveness of an ambient tax/subsidy policy in a setting with realistic in-stream nutrient transport dynamics when varying levels of sensor information on ambient pollution are available to the agents and the regulator. We find that increasing the frequency of ambient monitoring improves the spatial allocation of emissions reductions. In particular, with more frequent monitoring, the ambient-based policy induces firms further from the monitoring point to reduce emissions significantly more than downstream firms. Overall, the results suggest that enhanced temporal resolution of monitoring leads to efficiency gains.

  12. NASA-Modified Precipitation Products to Improve EPA Nonpoint Source Water Quality Modeling for the Chesapeake Bay

    Science.gov (United States)

    Nigro, Joseph; Toll, David; Partington, Ed; Ni-Meister, Wenge; Lee, Shihyan; Gutierrez-Magness, Angelica; Engman, Ted; Arsenault, Kristi

    2010-01-01

    The Environmental Protection Agency (EPA) has estimated that over 20,000 water bodies within the United States do not meet water quality standards. Ninety percent of the impairments are typically caused by nonpoint sources. One of the regulations in the Clean Water Act of 1972 requires States to monitor the Total Maximum Daily Load (TMDL), or the amount of pollution that can be carried by a water body before it is determined to be "polluted", for any watershed in the U.S.. In response to this mandate, the EPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a Decision Support Tool (DST) for assessing pollution and to guide the decision making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program -- Fortran (HSPF), computes daily stream flow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA modified/NOAA precipitation data. Using these data within HSPF, stream flow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better stream flow statistics and, ultimately, in improved water quality assessment.

  13. Estimation of contribution from non-point sources to perfluorinated surfactants in a river by using boron as a wastewater tracer.

    Science.gov (United States)

    Nishikoori, Hiroshi; Murakami, Michio; Sakai, Hiroshi; Oguma, Kumiko; Takada, Hideshige; Takizawa, Satoshi

    2011-08-01

    The contribution of non-point sources to perfluorinated surfactants (PFSs) in a river was evaluated by estimating their fluxes and by using boron (B) as a tracer. The utility of PFSs/B as an indicator for evaluating the impact of non-point sources was demonstrated. River water samples were collected from the Iruma River, upstream of the intake of drinking water treatment plants in Tokyo, during dry weather and wet weather, and 13 PFSs, dissolved organic carbon (DOC), total nitrogen (TN), and B were analyzed. Perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluoroheptanoate (PFHpA), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA), perfluoroundecanoate (PFUA), and perfluorododecanoate (PFDoDA) were detected on all sampling dates. The concentrations and fluxes of perfluorocarboxylates (PFCAs, e.g. PFOA and PFNA) were higher during wet weather, but those of perfluoroalkyl sulfonates (PFASs, e.g. PFHxS and PFOS) were not. The wet/dry ratios of PFSs/B (ratios of PFSs/B during wet weather to those during dry weather) agreed well with those of PFS fluxes (ratios of PFS fluxes during wet weather to those during dry weather), indicating that PFSs/B is useful for evaluating the contribution from non-point sources to PFSs in rivers. The wet/dry ratios of PFOA and PFNA were higher than those of other PFSs, DOC, and TN, showing that non-point sources contributed greatly to PFOA and PFNA in the water. This is the first study to use B as a wastewater tracer to estimate the contribution of non-point sources to PFSs in a river.

  14. Effects of Forest Ecosystems on Non-point Pollution Control%森林生态系统对非点源污染的控制机理与效果及其影响因素

    Institute of Scientific and Technical Information of China (English)

    张灿强; 张彪; 李文华; 杨艳刚; 王斌

    2011-01-01

    Non-point source pollution, particularly agricultural non-point source pollution, has become a major contributor of water pollution in many countries during recent years. Major lakes and rivers in China have suffered from serious eutrophication problems, e.g., five lakes (Poyang Lake, Dongting Lake, Taihu Lake, Hongze Lake, and Chaohu Lake), the Three Gorges Reservoir,Baiyangdian Lake, Nansi Lake, and Yilong Lake. The contribution rate of non-point pollution to eutrophication has been found to be much higher than point source pollution. Although tremendous efforts have been made to control non-point pollution, they seem to be far from effective due to uncertain emissions of the non-point pollutants. As such, people are resorting to purifying natural ecosystems, e.g., forest riparian buffer has been recommended as one of the Best Management Practices (BMP) for non-point source pollutant control in the United States. The authors comprehensively summarized studies associated with the effects of forest ecosystems on non-point source pollution control. Forest ecosystems have been shown to be of the capacity to adsorb and purify non-point source pollutants mainly through plants, canopy, ground litter, and soil layers.Plant uptake is one of important mechanisms of nutrients control. Part of pollutions carried by rainfall can be intercepted by canopy, while the nutrient content will increase because of eluviations. However, the non-point pollution can be greatly reduced after runoff flow through ground cover and soil layer. Numerous studies show that forests could reduce about 60~90% of the total nitrogen and phosphorus from upper farming areas. Non-point source pollution control is generally affected by many factors. The forest belt width has an impact on the effect of non-point source pollution reduction, and therefore the width needs to be adjusted appropriately. Different tree species show varying absorption capacities of non-point source pollutants; therefore the

  15. 兰州农村面源污染现状及防治对策分析%The Analysis of the Rural Non-point Source Pollution Situation and Countermeasures in Lan Zhou City

    Institute of Scientific and Technical Information of China (English)

    桂洪杰; 赵军平; 杜海霞; 张君弟; 刘佳

    2011-01-01

    文中在兰州统计年鉴的基础上,根据面源污染来源,分析了农业、畜牧业、生产和生活活动的危害,初步估算了主要面源污染物的流失量。并根据兰州市农村具体情况提出了相应的保护和控制措施,旨在为解决农村面源污染问题和保护农村生态环境提供借鉴。%In this paper,on the basis of Lan Zhou statistical yearbook,We analyzed the dangers of agriculture,animal husbandry,production activities and life activities according to the sources of rural non-point pollution,and then,we preliminary estimate the loss of the main non-point pollutant.In order to Provide reference for solving the problem of non-point pollution and the rural ecological environment protection,we put forward the corresponding protection and control measures,according to the specific situation of Lan Zhou countryside.

  16. [Nonpoint source pollution model, AnnAGNPS, assessment for a mixed forested watershed in Three Gorges Reservoir area].

    Science.gov (United States)

    Huang, Zhi-lin; Tian, Yao-wu; Xiao, Wen-fa; Zeng, Li-xiong; Ma, De-ju

    2009-10-15

    Watershed models provide a cost-effective and efficient means of estimating the pollutant loadings entering surface waters, especially when combined with traditional water quality sampling and analyses. But there have often been questions about the accuracy or certainty of models and their predictions. The main goal of this study was to evaluate the performance of AnnAGNPS (Annualized AGricultural NonPoint Source)Pollution Model, in simulating runoff, sediment loading and nutrient loadings under Three Gorges Reservoir area. Most of model input parameters were sourced from Zigui Forest Ecology Station in Three Gorges Reservoir area, State Forestry Administration. Data year 2003 was used for calibration while data year 2004 was used for validation of the model. The whole evaluation consisted of determining the coefficient of determination (R2), Nash-Sutcliffe coefficient of efficiency (E), and the percentage volume error (VE). Results showed that the model predicted the daily runoff volume within the range of acceptable accuracy. The runoff on a daily basis was underpredicted by 5.0% with R2 of 0.93 (p mixed types of land uses and steep slopes.

  17. Assessment of nonpoint-source contamination of the High Plains Aquifer in south-central Kansas, 1987

    Science.gov (United States)

    Helgesen, John O.; Stullken, Lloyd E.; Rutledge, A.T.

    1994-01-01

    Ground-water quality was assessed in a 5,000-square-mile area of the High Plains aquifer in south-central Kansas that is susceptible to nonpoint-source contamination from agricultural and petroleum-production activities. Of particular interest was the presence of agricultural chemicals and petroleum-derived hydrocarbons that might have been associated with brines that formerly were disposed into unlined ponds. Random sampling of ground water was done within a framework of discrete land-use areas (irrigated cropland, petroleum-production land containing former brine-disposal ponds, and undeveloped rangeland) of 3-10 square miles. Although true baseline water-quality conditions probably are rare, in this region they are represented most closely by ground water in areas of undeveloped rangeland. The sampling design enabled statistical hypothesis testing, using nonparametric procedures, of the effects of land use, unsaturated-zone lithology, and type of well sampled. Results indicate that regional ground-water quality has been affected by prevailing land-use activities, as shown by increased concentrations of several inorganic constituents. Ground water beneath irrigated cropland was characterized by significantly larger concentrations of hardness, alkalinity, calcium, magnesium, potassium, fluofide, and nitrite plus nitrate than was water beneath undeveloped rangeland. Few nondegraded pesticides were detected in the aquifer, probably because of degradation and sorption. Atrazine was the most common, but only in small concentrations. round water beneath petroleum-production land was characterized by significantly larger concentrations of hardness, alkalinity, dissolved solids, sodium, and chloride than was water beneath undeveloped rangeland. Nonpoint-source contamination by oil-derived hydrocarbons was not discernible. The occurrences of trace organic compounds were similar between petroleum-production land and undeveloped rangeland, which indicates a natural origin

  18. Assessment of the impacts of land use changes on nonpoint source pollution inputs upstream of the Three Gorges Reservoir.

    Science.gov (United States)

    Yang, Huicai; Wang, Guoqiang; Yang, Yan; Xue, Baolin; Wu, Binbin

    2014-01-01

    In recent years, land use upstream of the Three Gorges Reservoir (TGR) has changed significantly because of the TGR project. In this study, the Soil and Water Assessment Tool (SWAT) model was examined for its ability to assess relationships between land use changes and nonpoint pollutant indexes upstream of the TGR. Results indicated that the SWAT model, calibrated with the adjusted parameters, could successfully reproduce the nonpoint indexes at the water quality monitoring sites in the two rivers. The different land use change types were shown to be sensitive to nonpoint pollutants in the study area. The land use change type from upland to water was the strongest influence on changes in total nitrogen and total phosphorus. An empirical regression equation between nonpoint indexes and different land use change types was developed for the study area by partial least squares regression (PLSR) as follows: Y = b 0 + ∑ i=1 (m) b i X i. This regression equation was useful for evaluating the influence of land use change types on changes in nonpoint pollutants over a long time period. The results from this study may be useful for the TGR management and may help to reduce nonpoint pollutant loads into downstream water bodies.

  19. Impact of Point and Non-point Source Pollution on Coral Reef Ecosystems In Mamala Bay, Oahu, Hawaii based on Water Quality Measurements and Benthic Surveys in 1993-1994 (NODC Accession 0001172)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The effects of both point and non-point sources of pollution on coral reef ecosystems in Mamala Bay were studied at three levels of biological organization; the...

  20. Non-point Source Pollution Modeling Using Geographic Information System (GIS for Representing Best Management Practices (BMP in the Gorganrood Watershed

    Directory of Open Access Journals (Sweden)

    Z. Pasandidehfard

    2014-09-01

    Full Text Available The most important pollutants that cause water pollution are nitrogen and phosphorus from agricultural runoff called Non-Point Source Pollution (NPS. To solve this problem, management practices known as BMPs or Best Management Practices are applied. One of the common methods for Non-Point Source Pollution prediction is modeling. By modeling, efficiency of many practices can be tested before application. In this study, land use changes were studied from the years 1984 till 2010 that showed an increase in agricultural lands from 516908.52 to 630737.19 ha and expansion of cities from 5237.87 to 15487.59 ha and roads from 9666.07 to 11430.24 ha. Using L-THIA model (from nonpoint source pollution models for both land use categories, the amount of pollutant and the volume of runoff were calculated that showed high growth. Then, the seventh sub-basin was recognized as a critical zone in terms of pollution among the sub-basins. In the end, land use change was considered as a BMP using Multi-Criteria Evaluation (MCE based on which a more suitable land use map was produced. After producing the new land use map, L-THIA model was run again and the result of the model was compared to the actual land use to show the effect of this BMP. Runoff volume decreased from 367.5 to 308.6 M3/ha and nitrogen in runoff was reduced from 3.26 to 1.58 mg/L and water BOD from 3.61 to 2.13 mg/L. Other pollutants also showed high reduction. In the end, land use change is confirmed as an effective BMP for Non-Point Source Pollution reduction.

  1. Estimating the benefits of land imagery in environmental applications: a case study in nonpoint source pollution of groundwater

    Science.gov (United States)

    Bernknopf, Richard L.; Forney, William M.; Raunikar, Ronald P.; Mishra, Shruti K.; Laxminarayan, Ramanan; Maccauley, Molly K.

    2012-01-01

    Moderate-resolution land imagery (MRLI) is crucial to a more complete assessment of the cumulative, landscape-level effect of agricultural land use and land cover on environmental quality. If this improved assessment yields a net social benefit, then that benefit reflects the value of information (VOI) from MRLI. Environmental quality and the capacity to provide ecosystem services evolve because of human actions, changing natural conditions, and their interaction with natural physical processes. The human actions, in turn, are constrained and redirected by many institutions and regulations such as agricultural, energy, and environmental policies. We present a general framework for bringing together sociologic, biologic, physical, hydrologic, and geologic processes at meaningful scales to interpret environmental implications of MRLI applications. We set out a specific application using MRLI observations to identify crop planting patterns and thus estimate surface management activities that influence groundwater resources over a regional landscape. We tailor the application to the characteristics of nonpoint source groundwater pollution hazards in Iowa to illustrate a general framework in a land use-hydrologic-economic system. In the example, MRLI VOI derives from reducing the risk of both losses to agricultural production and damage to human health and other consequences of contaminated groundwater.

  2. NASA-modified precipitation products to improve USEPA nonpoint source water quality modeling for the Chesapeake Bay.

    Science.gov (United States)

    Nigro, Joseph; Toll, David; Partington, Ed; Ni-Meister, Wenge; Lee, Shihyan; Gutierrez-Magness, Angelica; Engman, Ted; Arsenault, Kristi

    2010-01-01

    The USEPA has estimated that over 20,000 water bodies within the United States do not meet water quality standards. One of the regulations in the Clean Water Act of 1972 requires states to monitor the total maximum daily load, or the amount of pollution that can be carried by a water body before it is determined to be "polluted," for any watershed in the United States (Copeland, 2005). In response to this mandate, the USEPA developed Better Assessment Science Integrating Nonpoint Sources (BASINS) as a decision support tool for assessing pollution and to guide the decision-making process for improving water quality. One of the models in BASINS, the Hydrological Simulation Program-Fortran (HSPF), computes continuous streamflow rates and pollutant concentration at each basin outlet. By design, precipitation and other meteorological data from weather stations serve as standard model input. In practice, these stations may be unable to capture the spatial heterogeneity of precipitation events, especially if they are few and far between. An attempt was made to resolve this issue by substituting station data with NASA-modified/NOAA precipitation data. Using these data within HSPF, streamflow was calculated for seven watersheds in the Chesapeake Bay Basin during low flow periods, convective storm periods, and annual flows. In almost every case, the modeling performance of HSPF increased when using the NASA-modified precipitation data, resulting in better streamflow statistics and, potentially, in improved water quality assessment.

  3. A distributed non-point source pollution model:calibration and validation in the Yellow River Basin

    Institute of Scientific and Technical Information of China (English)

    HAO Fang-bua; ZHANG Xue-song; YANG Zhi-feng

    2004-01-01

    The applicability of a non-point source pollution model-SWAT(soil and water assessment tools) in a large river basin with high sediment runoff modulus(770 t/km2 in the Yellow River) was examined. The basic database,which includes DEM, soil and landuse map, weather data, and land management data, was established for the study area using GIS. A two-stage "Brute Force" optimization method was used to calibrate the parameters with the observed monthly flow and sediment data from 1992 to 1997. In the process of calibration automated digital filter technique was used to separate direct runoff and base flow. The direct runoff was firstly calibrated, and the base flow, then the total runoff was matched. The sediment yield was calibrated to match well. Keeping input parameters set during the calibration process unchanged, the model was validated with 1998-1999's observed monthly flow and sediment. The evaluation coefficients for simulated and observed flow and sediment showed that SWAT was successfully applied in the study area: relative error was within 20%, coefficient of determination and Nash-Suttcliffe simulation efficiency were all equal to or above 0.70 during calibration and validation period.

  4. Assessment of the relationship between rural non-point source pollution and economic development in the Three Gorges Reservoir Area.

    Science.gov (United States)

    Zhang, Tong; Ni, Jiupai; Xie, Deti

    2016-04-01

    This study investigates the relationship between rural non-point source (NPS) pollution and economic development in the Three Gorges Reservoir Area (TGRA) by using the Environmental Kuznets Curve (EKC) hypothesis for the first time. Five types of pollution indicators, namely, fertilizer input density (FD), pesticide input density (PD), agricultural film input density (AD), grain residues impact (GI), and livestock manure impact (MI), were selected as rural NPS pollutant variables. Rural net income per capita was used as the indicator of economic development. Pollution load was generated by agricultural inputs (consumption of fertilizer, pesticide, and agricultural film) and economic growth with invert U-shaped features. The predicted turning points for FD, PD, and AD were at rural net income per capita levels of 6167.64, 6205.02, and 4955.29 CNY, respectively, which were all surpassed. However, the features between agricultural waste outputs (grain residues and livestock manure) and economic growth were inconsistent with the EKC hypothesis, which reflected the current trends of agricultural economic structure in the TGRA. Given that several other factors aside from economic development level could influence the pollutant generation in rural NPS, a further examination with long-run data support should be performed to understand the relationship between rural NPS pollution and income level.

  5. Long-term agricultural non-point source pollution loading dynamics and correlation with outlet sediment geochemistry

    Science.gov (United States)

    Ouyang, Wei; Jiao, Wei; Li, Xiaoming; Giubilato, Elisa; Critto, Andrea

    2016-09-01

    Some agricultural non-point source (NPS) pollutants accumulate in sediments in the outlet sections of watersheds. It is crucial to evaluate the historical interactions between sediment properties and watershed NPS loading. Therefore, a sediment core from the outlet of an agricultural watershed was collected. The core age was dated using the 210Pb method, and sedimentation rates were determined using the constant rate of supply (CRS) model. The total nitrogen (TN), total phosphorus (TP), Cd, Pb, Cu, Ni and Cr accumulations in the sediment generally showed fluctuating increases, with the highest sedimentation fluxes all occurring in approximately 1998. The measurement of specific mass sedimentation rates reflected a record of watershed soil erosion dynamics. Using SWAT (Soil and Water Assessment Tool) to simulate long-term watershed agricultural NPS pollution loadings, the historical interactions between sediment properties and NPS loadings were further evaluated. The N leaching process weakened these interactions, but the historical accumulations of TP and heavy metals in sediments generally correlated well with watershed NPS TP loading. The regression analysis suggested that Pb and Cr were the most suitable indexes for assessing long-term NPS TN and TP pollution, respectively. Assessing the NPS loading dynamics using the vertical characteristics of sediment geochemistry is a new method.

  6. Non-point source analysis of a railway bridge area using statistical method: case study of a concrete road-bed.

    Science.gov (United States)

    Gil, Kyungik; Im, Jiyeol

    2014-06-01

    In an effort to protect the quality of the water system, interest in non-point source pollution is increasing. Recently, studies of non-point sources pollution are continuing in relation to various land-use areas, but such studies have not been fully conducted in railway facility sites. Using monitoring data of railway bridge area with concrete road-bed, the runoff characteristics, pollutant unit loads, and first flush criteria were assessed. Railway bridge area with concrete road-bed typically show the first flush effect, and the pollutant unit load was determined to be higher than other public facilities areas. Further, the first flush criteria show an effective rainfall amount of 7 mm. In other words, from the runoff of railway facilities, considerable amounts of non-point source pollutants are occurred, indicating the need to create best management practices which are adequate for railway facility sites. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  7. Demonstration and Effects of Best Management Practices Applied to Control of Rural Non-point Source Pollution in Poyang Lake Area%鄱阳湖区农村面源污染控制中最佳管理措施示范研究

    Institute of Scientific and Technical Information of China (English)

    万金保; 孙蕾; 刘峰; 汤爱萍

    2012-01-01

    Water environment security in rural areas around Poyang Lake has been threatened by increasingly severe non-point source pollution(NPS pollution).Combined with the features of NPS pollution in the areas,the structural best management practices(BMPs) are established in the demonstration area of Xingzi County to control the rural NPS pollution.Monitoring results show that in the monitoring period,the removal amounts of COD,TP and TN by the BMPs are 568.25,3.06 and 26.90 kg,respectively.Constructed wetland maintains the better and more stable pollutant removal capability and the removal amounts of COD,TP and TN per unit area are about 40,0.4 and 3.0 g/m2,respectively.The removal amounts of the pollutants per unit area by ecological ditch vary greatly.Ecological ditch has better removal ability per unit area than constructed wetland,but has poor stability.In consideration of the advantages of ecological ditch and tri-class surface flow constructed wetland(3-SFW),the plants suitable to ecological ditch are recommended to improve its stability in pollutant removal.%鄱阳湖区农村面源污染问题日益严峻,已威胁到湖泊的水环境安全。结合该区域农村面源污染自身的变化特征,在星子县示范区内构建结构性最佳管理措施BMPs(best management practices)系统对区域内农村面源污染进行控制。结果表明,在监测期间该BMPs系统对COD,TP和TN的削减量分别为568.25,3.06和26.90kg。其中人工湿地对COD,TP和TN的单位面积削减量约达40,0.4和3.0g/m2,有较稳定的污染物去除能力;生态沟渠对各污染物单位面积削减量变化较大,与人工湿地相比虽有更强的污染物削减能力,但稳定性较弱。结合生态沟渠和三级表面流人工湿地的特点,建议通过引入适宜的植物至生态沟渠提高其处理污染物的稳定性。

  8. The simulation research of dissolved nitrogen and phosphorus non-point source pollution in Xiao-Jiang watershed of Three Gorges Reservoir area.

    Science.gov (United States)

    Wu, Lei; Long, Tian-Yu; Li, Chong-Ming

    2010-01-01

    Xiao-jiang, with a basin area of almost 5,276 km(2) and a length of 182.4 km, is located in the center of the Three Gorges Reservoir Area, and is the largest tributary of the central section in Three Gorges Reservoir Area, farmland accounts for a large proportion of Xiao-jiang watershed, and the hilly cropland of purple soil is much of the farmland of the watershed. After the second phase of water storage in the Three Gorges Reservoir, the majority of sub-rivers in the reservoir area experienced eutrophication phenomenon frequently, and non-point source (NPS) pollution has become an important source of pollution in Xiao-jiang Watershed. Because dissolved nitrogen and phosphorus non-point source pollution are related to surface runoff and interflow, using climatic, topographic and land cover data from the internet and research institutes, the Semi-Distributed Land-use Runoff Process (SLURP) hydrological model was introduced to simulate the complete hydrological cycle of the Xiao-jiang Watershed. Based on the SLURP distributed hydrological model, non-point source pollution annual output load models of land use and rural residents were respectively established. Therefore, using GIS technology, considering the losses of dissolved nitrogen and phosphorus in the course of transport, a dissolved non-point source pollution load dynamic model was established by the organic coupling of the SLURP hydrological model and land-use output model. Through the above dynamic model, the annual dissolved non-point source nitrogen and phosphorus pollution output as well as the load in different types were simulated and quantitatively estimated from 2001 to 2008, furthermore, the loads of Xiao-jiang Watershed were calculated and expressed by temporal and spatial distribution in the Three Gorges Reservoir Area. The simulation results show that: the temporal changes of dissolved nitrogen and phosphorus load in the watershed are close to the inter-annual changes of rainfall runoff, and the

  9. EXPERIMENTAL STUDY ON NONPOINT SOURCE NUTRIENT OUTPUT FROM XIANGXI BASIN IN THREE GORGES RESERVOIR%三峡库区香溪河流域非点源营养盐输出变化的试验研究

    Institute of Scientific and Technical Information of China (English)

    宋林旭; 刘德富; 肖尚斌

    2011-01-01

    综合三峡库区香溪河流域土地利用结构和水系特点,在三大支流出口处设置常规水质监测断面,于干流响滩处设置水文控制断面,通过断面水质水量监测,利用数字滤波法解析径流多源和污染多源,研究上游来流点源和非点源营养盐输出负荷变化。结果表明:受农业非点源污染影响,TN是高岚河(0.788mg/L)〉古夫河(0.712mg/L)〉南阳河(0.567mg/L);南阳河受磷矿企业点源输入的影响,TP是南阳河(0.323mg/L)〉高岚河(0.074mg/L)〉古夫河(0.053mg/L);断面流量与降雨量的相关系数R2=0.%In order to study non-point source nutrient from Xiangxi River,considering the characteristics of the land use and the basin network,establishing the regular quality monitoring and hydrographic control section respectively in 3 major branches and upstream main channel.According to the water quality and quantity monitoring data,studying the spatial and temporal variation of the water quality from the upstream and the flux output process during raining,distinguishing the contribution of nonpoint and point source pollution load by digital filtering technology.The results demonstrate:controlled by agriculture nonpoint source pollution,TN is in GLGFNY,because of the point source pollution from P enterprise,TP is in NYGLGF;the correlation coefficient of flow and rainfall is 0.720 2;annual load ratio of TN and TP is 61% and 40%,during raining,the TN and TP contribution from nonpoint source pollution is 75.2% and 70.9%;the pollution load is decided by the runoff,the correlation of TN/TP load and runoff is that TN is 0.963 6,and TP is 0.978 9.

  10. A review on Non-point Source Nutrient Pollution of Irrigation Plain Areas%平原灌区农田养分非点源污染研究进展

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    development of agriculture, and the research of this problem has important significance. This paper reviews the research of the plain irrigation non-point source pollution based on the process of pollution transport with water cycling: (1) The main sources of non-point source pollution are fertilizer, pesticide and agricultural films, waste material dropped by farm animals, soil salinization and atmospheric deposition (dry and wet); the occurrence of plain irrigated farmland non-point sources pollution was affected by the physical and chemical properties of soil, water input pattern and artificial management measures. (2) The rainfall-runoff, pollution migration in multi-level irrigation and drainage system and the coupling interaction between ground water and surface water were the main characteristics of plain irrigated farmland non-point source pollution transport mechanism. (3) In order to estimate the load of plain irrigated farmland non-point source pollution, export coefficient model was used when there is a data shortage, whereas improved classical hydrological model was used when the data is adequate. And (4) the usage of preferred fertilizer compositions for special plant, reasonable soil and water conservation farming measures and ecology ditches were beneficial to the control of non-point source pollution in plain irrigated area. TMDL (Total Maximum Daily Load) plan can provide reliable basis for non-point source control in plain irrigated area. This paper has analyzed the problems that exist in the plain irrigated farmland non-point pollution at present, put forward suggestions for research priorities on this basis, including nutrient pollutants migration in the multi-stage ditches, irrigation water quantity and quality of surface and groundwater coupled model, hierarchical control unit and TMDL plan development and so on, which will be helpful for making a decision on sustainable agricultural development.

  11. Assessing the effects of rural livelihood transition on non-point source pollution: a coupled ABM-IECM model.

    Science.gov (United States)

    Yuan, Chengcheng; Liu, Liming; Ye, Jinwei; Ren, Guoping; Zhuo, Dong; Qi, Xiaoxing

    2017-04-02

    Water pollution caused by anthropogenic activities and driven by changes in rural livelihood strategies in an agricultural system has received increasing attention in recent decades. To simulate the effects of rural household livelihood transition on non-point source (NPS) pollution, a model combining an agent-based model (ABM) and an improved export coefficient model (IECM) was developed. The ABM was adopted to simulate the dynamic process of household livelihood transition, and the IECM was employed to estimate the effects of household livelihood transition on NPS pollution. The coupled model was tested in a small catchment in the Dongting Lake region, China. The simulated results reveal that the transition of household livelihood strategies occurred with the changes in the prices of rice, pig, and labor. Thus, the cropping system, land-use intensity, resident population, and number of pigs changed in the small catchment from 2000 to 2014. As a result of these changes, the total nitrogen load discharged into the river initially increased from 6841.0 kg in 2000 to 8446.3 kg in 2004 and then decreased to 6063.9 kg in 2014. Results also suggest that rural living, livestock, paddy field, and precipitation alternately became the main causes of NPS pollution in the small catchment, and the midstream region of the small catchment was the primary area for NPS pollution from 2000 to 2014. Despite some limitations, the coupled model provides an innovative way to simulate the effects of rural household livelihood transition on NPS pollution with the change of socioeconomic factors, and thereby identify the key factors influencing water pollution to provide valuable suggestions on how agricultural environmental risks can be reduced through the regulation of the behaviors of farming households in the future.

  12. Water and nonpoint source pollution estimation in the watershed with limited data availability based on hydrological simulation and regression model.

    Science.gov (United States)

    Huiliang, Wang; Zening, Wu; Caihong, Hu; Xinzhong, Du

    2015-09-01

    Nonpoint source (NPS) pollution is considered as the main reason for water quality deterioration; thus, to quantify the NPS loads reliably is the key to implement watershed management practices. In this study, water quality and NPS loads from a watershed with limited data availability were studied in a mountainous area in China. Instantaneous water discharge was measured through the velocity-area method, and samples were taken for water quality analysis in both flood and nonflood days in 2010. The streamflow simulated by Hydrological Simulation Program-Fortran (HSPF) from 1995 to 2013 and a regression model were used to estimate total annual loads of various water quality parameters. The concentrations of total phosphorus (TP) and total nitrogen (TN) were much higher during the flood seasons, but the concentrations of ammonia nitrogen (NH3-N) and nitrate nitrogen (NO3-N) were lower during the flood seasons. Nevertheless, only TP concentration was positively correlated with the flow rate. The fluctuation of annual load from this watershed was significant. Statistical results indicated the significant contribution of pollutant fluxes during flood seasons to annual fluxes. The loads of TP, TN, NH3-N, and NO3-N in the flood seasons were accounted for 58-85, 60-82, 63-88, 64-81% of the total annual loads, respectively. This study presented a new method for estimation of the water and NPS loads in the watershed with limited data availability, which simplified data collection to watershed model and overcame the scale problem of field experiment method.

  13. Enabling and Enacting `Practical Action' in Catchments: Responding to the `Wicked Problem' of Nonpoint Source Pollution in Coastal Subtropical Australia

    Science.gov (United States)

    Patterson, James J.; Smith, Carl; Bellamy, Jennifer

    2015-02-01

    Enabling and enacting `practical action' (i.e., purposeful and concerted collective action) in catchments is a key challenge in responding to a wide range of pressing catchment and natural resource management (NRM) issues. It is particularly a challenge in responding to `wicked problems,' where generating action is not straightforward and cannot be brought about solely by any single actor, policy or intervention. This paper responds to the critical need to better understand how practical action can be generated in catchments, by conducting an in-depth empirical case study of efforts to manage nonpoint source (NPS) pollution in South East Queensland (SEQ), Australia. SEQ has seen substantial concerted efforts to manage waterway and catchment issues over two decades, yet NPS pollution remains a major problem for waterway health. A novel framework was applied to empirically analyze practical action in three local catchment cases embedded within the broader SEQ region. The analysis focuses on `enabling capacities' underpinning practical action in catchments. Findings reveal that capacities manifested in different ways in different cases, yet many commonalities also occurred across cases. Interplay between capacities was critical to the emergence of adaptive and contextual forms of practical action in all cases. These findings imply that in order to enable and enact practical action in catchments, it is vital to recognize and support a diversity of enabling capacities across both local and regional levels of decision making and action. This is likely to have relevance for other `wicked' catchment and NRM problems requiring local responses within broader multiscalar regional problem situations.

  14. Enabling and enacting 'practical action' in catchments: responding to the 'wicked problem' of nonpoint source pollution in coastal subtropical Australia.

    Science.gov (United States)

    Patterson, James J; Smith, Carl; Bellamy, Jennifer

    2015-02-01

    Enabling and enacting 'practical action' (i.e., purposeful and concerted collective action) in catchments is a key challenge in responding to a wide range of pressing catchment and natural resource management (NRM) issues. It is particularly a challenge in responding to 'wicked problems,' where generating action is not straightforward and cannot be brought about solely by any single actor, policy or intervention. This paper responds to the critical need to better understand how practical action can be generated in catchments, by conducting an in-depth empirical case study of efforts to manage nonpoint source (NPS) pollution in South East Queensland (SEQ), Australia. SEQ has seen substantial concerted efforts to manage waterway and catchment issues over two decades, yet NPS pollution remains a major problem for waterway health. A novel framework was applied to empirically analyze practical action in three local catchment cases embedded within the broader SEQ region. The analysis focuses on 'enabling capacities' underpinning practical action in catchments. Findings reveal that capacities manifested in different ways in different cases, yet many commonalities also occurred across cases. Interplay between capacities was critical to the emergence of adaptive and contextual forms of practical action in all cases. These findings imply that in order to enable and enact practical action in catchments, it is vital to recognize and support a diversity of enabling capacities across both local and regional levels of decision making and action. This is likely to have relevance for other 'wicked' catchment and NRM problems requiring local responses within broader multiscalar regional problem situations.

  15. Investigating the effects of point source and nonpoint source pollution on the water quality of the East River (Dongjiang) in South China

    Science.gov (United States)

    Wu, Yiping; Chen, Ji

    2013-01-01

    Understanding the physical processes of point source (PS) and nonpoint source (NPS) pollution is critical to evaluate river water quality and identify major pollutant sources in a watershed. In this study, we used the physically-based hydrological/water quality model, Soil and Water Assessment Tool, to investigate the influence of PS and NPS pollution on the water quality of the East River (Dongjiang in Chinese) in southern China. Our results indicate that NPS pollution was the dominant contribution (>94%) to nutrient loads except for mineral phosphorus (50%). A comprehensive Water Quality Index (WQI) computed using eight key water quality variables demonstrates that water quality is better upstream than downstream despite the higher level of ammonium nitrogen found in upstream waters. Also, the temporal (seasonal) and spatial distributions of nutrient loads clearly indicate the critical time period (from late dry season to early wet season) and pollution source areas within the basin (middle and downstream agricultural lands), which resource managers can use to accomplish substantial reduction of NPS pollutant loadings. Overall, this study helps our understanding of the relationship between human activities and pollutant loads and further contributes to decision support for local watershed managers to protect water quality in this region. In particular, the methods presented such as integrating WQI with watershed modeling and identifying the critical time period and pollutions source areas can be valuable for other researchers worldwide.

  16. Present Situation and Countermeasures of Agricultural Non-point Source Pollution in Wuhan City%武汉市农业面源污染现状及治理对策

    Institute of Scientific and Technical Information of China (English)

    汪坤乾; 张凯; 苏斌; 夏杏明; 汤少云

    2014-01-01

    从化肥施用、农药使用、农膜使用现状3个方面阐述了武汉市农业面源污染现状和为害性,分析了武汉市农业面源污染产生的原因,提出了建立政府主导的农业面源污染治理机制、应用化肥减量化技术、应用农药减量化和残留控制技术、推广可降解地膜等治理面源污染的对策。%We pointed out the status and harmfulness of agricultural non-point source pollution in Wuhan from the three aspects, including the application of chemical fertilizer, pesticide and agricultural film, and analyzed the factors that caused the problem, in addition, we put forward related countermeasures, including establishing the government leading mechanism to control agricultural non-point source pollution, using chemical fertilizer reduction technology, applying pesticide reduction and residue control technology, and using biodegradable plastic film.

  17. Distributed Simulation of Non-Point Source Pollution in Ashi River Basin

    Institute of Scientific and Technical Information of China (English)

    Fang Ma; Xiaofeng Jiang; Li Wang; Zhe Li; Xiongwei Liang

    2015-01-01

    In order to get a thorough understanding of non⁃point source pollution, it is essential to examine its temporal and spatial distribution. A physically⁃based distributed model, Soil and Water Assessment Tool ( SWAT) , was used in this research, to quantitatively estimate the NPS load and analyze the temporal and spatial distributions of NPS pollution in Ashi River Basin. The results indicated that SWAT was suitable to simulate stream⁃flow and water quality in Ashi River Basin. Total Nitrogen which was contributed by NPS (NPS⁃TN) accounted for 32�47%-62�61%, and Total Phosphorus which was contributed by NPS (NPS⁃TP) accounted for 22�30%-57�85% of the total load respectively. In inter⁃annual timescale, both NPS⁃TN and NPS⁃TP were influenced by stream⁃flow and fertilizer. However, when compared with fertilizer, NPS pollution was more directly affected by stream⁃flow. In annual timescale, NPS⁃TN and NPS⁃TP mainly occurred in flood season (from May to September). In the aspect of space, spatial differences of NPS⁃TN and NPS⁃TP were extremely significant. The spatial variations of NPS pollution were mainly influenced by land use, precipitation, soil and slope.

  18. A coupled model approach to reduce nonpoint-source pollution resulting from predicted urban growth: A case study in the Ambos Nogales watershed

    Science.gov (United States)

    Norman, L.M.; Guertin, D.P.; Feller, M.

    2008-01-01

    The development of new approaches for understanding processes of urban development and their environmental effects, as well as strategies for sustainable management, is essential in expanding metropolitan areas. This study illustrates the potential of linking urban growth and watershed models to identify problem areas and support long-term watershed planning. Sediment is a primary source of nonpoint-source pollution in surface waters. In urban areas, sediment is intermingled with other surface debris in transport. In an effort to forecast the effects of development on surface-water quality, changes predicted in urban areas by the SLEUTH urban growth model were applied in the context of erosion-sedimentation models (Universal Soil Loss Equation and Spatially Explicit Delivery Models). The models are used to simulate the effect of excluding hot-spot areas of erosion and sedimentation from future urban growth and to predict the impacts of alternative erosion-control scenarios. Ambos Nogales, meaning 'both Nogaleses,' is a name commonly used for the twin border cities of Nogales, Arizona and Nogales, Sonora, Mexico. The Ambos Nogales watershed has experienced a decrease in water quality as a result of urban development in the twin-city area. Population growth rates in Ambos Nogales are high and the resources set in place to accommodate the rapid population influx will soon become overburdened. Because of its remote location and binational governance, monitoring and planning across the border is compromised. One scenario described in this research portrays an improvement in water quality through the identification of high-risk areas using models that simulate their protection from development and replanting with native grasses, while permitting the predicted and inevitable growth elsewhere. This is meant to add to the body of knowledge about forecasting the impact potential of urbanization on sediment delivery to streams for sustainable development, which can be

  19. Export of non-point source suspended sediment, nitrogen, and phosphorus from sloping highland agricultural fields in the East Asian monsoon region.

    Science.gov (United States)

    Reza, Arif; Eum, Jaesung; Jung, Sungmin; Choi, Youngsoon; Owen, Jeffrey S; Kim, Bomchul

    2016-12-01

    Excess sediment and nutrient export from agricultural fields with steep slopes is a major concern linked to surface water quality in Korea. In this study, the export of suspended sediment (SS), total nitrogen (TN), and total phosphorus (TP) and their event mean concentrations (EMCs) in surface runoff from a highland mixed land use (61% forested, 30% cropped, 9% other) watershed were quantified. In 2007, the Korean Ministry of Environment (MoE) declared the study area as a priority region for non-point source (NPS) pollution management and initiated various best management practices (BMPs) in the study watershed. SS, TN, and TP concentrations in Mandae Stream were monitored for 5 years (2009-2013) to evaluate the effectiveness of BMPs. Average EMCs for SS, TN, and TP were as high as 986, 3.4 and 0.8 mg/L, respectively. The agricultural export coefficients of agricultural land in the study watershed for SS, TN, and TP were 5611, 171, and 6.83 kg/ha/year, respectively. A comparison with results from other studies shows that both EMCs and agricultural export coefficients in the study watershed were much higher than most of the results reported for watersheds in other regions. The results show that sediment and nutrient export from intensive agriculture areas with steep slopes continue to be a major concern for the downstream reservoir, Lake Soyang. Remedial strategies should be directed towards controlling sources of SS, TN, and TP to improve downstream water quality in sloping highland agricultural areas in Korea.

  20. Detection of spatial fluctuations of non-point source fecal pollution in coral reef surrounding waters in southwestern Puerto Rico using PCR-based assays.

    Science.gov (United States)

    Bonkosky, M; Hernández-Delgado, E A; Sandoz, B; Robledo, I E; Norat-Ramírez, J; Mattei, H

    2009-01-01

    Human fecal contamination of coral reefs is a major cause of concern. Conventional methods used to monitor microbial water quality cannot be used to discriminate between different fecal pollution sources. Fecal coliforms, enterococci, and human-specific Bacteroides (HF183, HF134), general Bacteroides-Prevotella (GB32), and Clostridium coccoides group (CP) 16S rDNA PCR assays were used to test for the presence of non-point source fecal contamination across the southwestern Puerto Rico shelf. Inshore waters were highly turbid, consistently receiving fecal pollution from variable sources, and showing the highest frequency of positive molecular marker signals. Signals were also detected at offshore waters in compliance with existing microbiological quality regulations. Phylogenetic analysis showed that most isolates were of human fecal origin. The geographic extent of non-point source fecal pollution was large and impacted extensive coral reef systems. This could have deleterious long-term impacts on public health, local fisheries and in tourism potential if not adequately addressed.

  1. 宁夏黄河灌区农业非点源污染损失估算%Economic loss caused by non-point source pollution ——A case study of Ningxia Yellow River Water Irrigation District

    Institute of Scientific and Technical Information of China (English)

    杨引禄; 冯永忠; 杨世琦; 曹艳春; 刘强; 杨改河

    2011-01-01

    Non-point source pollution have become more and more serious and brought enormous danger to water environment in Ningxia Yellow River Water Irrigation District, so it has important significance for ecological security to esti-mate the economic value of losses of pollution load in this area. In this paper, according to the JOHNES export coefficient method, calculation is made of non-point source pollution load in'Ningxia Yellow River Water Irrigation District, and the methoddology of enxironmental economics is used to reckon quantitatively economic loss caused by agricultural non-point source pollution. The results showed that the livestock breeding pollution contributed 41.27% to the pollution load of the area, and 37.25 % to the TN and 4.03 % to the TP pollution load of the area. The planting was the second and the rural domestic waste was the lowest proportion in non-point source pollution load, which was 34.54% and 24.2% to the pollution load of the area. The economic loss caused by the regional non-point source pollution was calculated at about 548.741 million RMB in total, of which about 40.97% was coutributed by livestock breeding pollution, while the planting and the rural areaa domestic waste respectively 35.6% and 23.4% to the all economic loss. This results illuminate that only the control of livestock breeding pollution can reduce economic loss caused by agricultural ono-point source pollution in Ningxia Yellow River Water Irrigation District.%以宁夏黄河灌区为研究区,在充分利用JOHNES输出系数法计算灌区非点源污染负荷的基础上,应用环境经济学中的恢复防护费用法对灌区农业非点源污染产生的负荷转化为经济损失进行估算.结果表明:宁夏黄河灌区禽畜养殖产生的污染负荷最高,占灌区污染负荷的41.27%,其中全氮排放占整个区域污染负荷的37.25%,全磷排放占整个区域污染负荷的4.03%,种植业产生的氮磷污染负荷次之,居民生活

  2. Agricultural non-point nitrogen pollution control function of different vegetation types in riparian wetlands: a case study in the Yellow River wetland in China.

    Science.gov (United States)

    Zhao, Tongqian; Xu, Huashan; He, Yuxiao; Tai, Chao; Meng, Hongqi; Zeng, Fanfu; Xing, Menglin

    2009-01-01

    Riparian wetland is the major transition zone of matter, energy and information transfer between aquatic and terrestrial ecosystems and has important functions of water purification and non-point pollution control. Using the field experiment method and an isotope tracing technique, the agricultural non-point nitrogen pollution control function of different vegetation types in riparian wetland was studied in the Kouma Section of the Yellow River. The results showed that the retention of agricultural non-point nitrogen pollution by riparian wetland soil occurs mainly in top 0-10 cm layer. The amount of nitrogen retained by surface soils associated with three types of vegetation are 0.045 mg/g for Phragmites communis Trin Linn, 0.036 mg/g for Scirpus triqueter Linn, and 0.032 mg/g for Typha angustifolia Linn, which account for 59.21%, 56.25%, and 56.14% of the total nitrogen interception, respectively. Exogenous nitrogen in 0-10 cm soil layer changes more quickly than in other layers. One month after adding K(15)NO3 to the tested vegetation, nitrogen content was 77.78% for P. communis Trin, 68.75% for T. angustifolia, and 8.33% for S. triqueter in the surface soil. After three months, nitrogen content was 93.33% for P. communis Trin, 72.22% for S. triqueter, and 37.50% for T. Angustifolia. There are large differences among vegetation communities respecting to purification of agricultural non-point nitrogen pollution. The nitrogen uptake amount decreases in the sequence: new shoots of P. communis Trin (9.731 mg/g) > old P. communis Trin (4.939 mg/g) > S. triqueter (0.620 mg/g) > T. angustifolia (0.186 mg/g). Observations indicated that the presence of riparian wetlands as buffers on and adjacent to stream banks could be recommended to control agricultural non-point pollution.

  3. Agricultural non-point nitrogen pollution control function of different vegetation types in riparian wetlands: A case study in the Yellow River wetland in China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Tongqian; XU Huashan; HE Yuxiao; TAI Chao; MENG Hongqi; ZENG Fanfu; XING Menglin

    2009-01-01

    Riparian wetland is the major transition zone of matter, energy and information transfer between aquatic and terrestrial ecosystems and has important functions of water purification and non-point pollution control. Using the field experiment method and an isotope tracing technique, the agricultural non-point nitrogen pollution control function of different vegetation types in riparian wetland was studied in the Kouma Section of the Yellow River. The results showed that the retention of agricultural non-point nitrogen pollution by riparian wetland soil occurs mainly in top 0-10 cm layer. The amount of nitrogen retained by surface soils associated with three types of vegetation are 0.045 mg/g for Phragmites communis Trin Lima, 0.036 mg/g for Scirpus triqueter Liun, and 0.032 mg/g for Typha angustifolia Linn, which account for 59.21%, 56.25%, and 56.14% of the total nitrogen interception, respectively. Exogenous nitrogen in 0-10 cm soil layer changes more quickly than in other layers. One month after adding K15NO3 to the tested vegetation, nitrogen content was 77.78% for P. Communis Trin, 68.75% for T. Angustifolia, and 8.33% for S. Triqueter in the surface soil. After three months, nitrogen content was 93.33% for P. Communis Trin, 72.22% for S. Triqueter, and 37.50% for T. Angustifolia. There are large differences among vegetation communities respecting to purification of agricultural non-point nitrogen pollution. The nitrogen uptake amount decreases in the sequence: new shoots of P. Communis Trin (9.731 mg/g)>old P. Communis Trin (4.939 mg/g)>S. Triqueter (0.620 mg/g)>T. Angustifolia (0.186 mg/g). Observations indicated that the presence of riparian wetlands as buffers on and adjacent to stream banks could be recommended to control agricultural non-point pollution.

  4. Application of modified export coefficient method on the load estimation of non-point source nitrogen and phosphorus pollution of soil and water loss in semiarid regions.

    Science.gov (United States)

    Wu, Lei; Gao, Jian-en; Ma, Xiao-yi; Li, Dan

    2015-07-01

    Chinese Loess Plateau is considered as one of the most serious soil loss regions in the world, its annual sediment output accounts for 90 % of the total sediment loads of the Yellow River, and most of the Loess Plateau has a very typical characteristic of "soil and water flow together", and water flow in this area performs with a high sand content. Serious soil loss results in nitrogen and phosphorus loss of soil. Special processes of water and soil in the Loess Plateau lead to the loss mechanisms of water, sediment, nitrogen, and phosphorus are different from each other, which are greatly different from other areas of China. In this study, the modified export coefficient method considering the rainfall erosivity factor was proposed to simulate and evaluate non-point source (NPS) nitrogen and phosphorus loss load caused by soil and water loss in the Yanhe River basin of the hilly and gully area, Loess Plateau. The results indicate that (1) compared with the traditional export coefficient method, annual differences of NPS total nitrogen (TN) and total phosphorus (TP) load after considering the rainfall erosivity factor are obvious; it is more in line with the general law of NPS pollution formation in a watershed, and it can reflect the annual variability of NPS pollution more accurately. (2) Under the traditional and modified conditions, annual changes of NPS TN and TP load in four counties (districts) took on the similar trends from 1999 to 2008; the load emission intensity not only is closely related to rainfall intensity but also to the regional distribution of land use and other pollution sources. (3) The output structure, source composition, and contribution rate of NPS pollution load under the modified method are basically the same with the traditional method. The average output structure of TN from land use and rural life is about 66.5 and 17.1 %, the TP is about 53.8 and 32.7 %; the maximum source composition of TN (59 %) is farmland; the maximum source

  5. Spatio-temporal variation of erosion-type non-point source pollution in a small watershed of hilly and gully region, Chinese Loess Plateau.

    Science.gov (United States)

    Wu, Lei; Liu, Xia; Ma, Xiao-Yi

    2016-06-01

    Loss of nitrogen and phosphorus in the hilly and gully region of Chinese Loess Plateau not only decreases the utilization rate of fertilizer but also is a potential threat to aquatic environments. In order to explore the process of erosion-type non-point source (NPS) pollution in Majiagou watershed of Loess Plateau, a distributed, dynamic, and integrated NPS pollution model was established to investigate impacts of returning farmland on erosion-type NPS pollution load from 1995 to 2012. Results indicate that (1) the integrated model proposed in this study was verified to be reasonable; the general methodology is universal and can be applicable to the hilly and gully region, Loess Plateau; (2) the erosion-type NPS total nitrogen (TN) and total phosphorus (TP) load showed an overall decreasing trend; the average nitrogen and phosphorus load modulus in the last four years (2009-2012) were 1.23 and 1.63 t/km(2) · a, respectively, which were both decreased by about 35.4 % compared with the initial treatment period (1995-1998); and (3) The spatial variations of NPS pollution are closely related to spatial characteristics of rainfall, topography, and soil and land use types; the peak regions of TN and TP loss mainly occurred along the main river banks of the Yanhe River watershed from northeast to southeast, and gradually decreased with the increase of distance to the left and right river banks, respectively. Results may provide scientific basis for the watershed-scale NPS pollution control of the Loess Plateau.

  6. Research progress in erosion-type nonpoint source poLLution process simuLationof the Loess PLateau%黄土高原水土流失型非点源污染过程模拟研究进展

    Institute of Scientific and Technical Information of China (English)

    吴磊; 马孝义

    2015-01-01

    Loss of nitrogen and phosphorus in soil and water loss area of the Loess Plateau not only reduces the utilization rate of fertilizer,but also is a potential threat to aquatic environments.This study takes the typicality of soil and nutrient loss in the Lo-ess Plateau Region as a starting point to deeply analyse and systematically summarize the basic status of the Loss Plateau,the re-search progress of hydrological process,soil erosion,erosion-type nonpoint source pollution and its control strategies of the Loess Plateau.Aiming at the few existing studies on the Loess Plateau,the key research directions of nonpoint source pollution in the Loess Plateau for the future were proposed,such as the loss mechanism of nonpoint source pollution,the load estimation method of nonpoint source pollution in the Loess Plateau,the coupled model of water,sediment and pollution in the Loess Plateau,the combined application of 3S technology and control strategies of erosion-type nonpoint source pollution in the Loess Plateau etc.This re-sult may provide reference for studying the modeling process of erosion-type nonpoint source pollution in the Loess Plateau.%黄土高原严重的水土流失造成了土壤氮磷流失,不仅降低了化肥的利用率,而且对水环境造成了潜在威胁。从黄土高原区水土与养分流失的典型性入手,剖析和总结了黄土高原区基本概况、水文过程、土壤侵蚀、水土流失型非点源污染过程模拟及防控策略等的研究进展。针对目前黄土高原区尤其是黄土丘陵沟壑区非点源污染研究较少,提出了未来黄土高原地区非点源污染的研究方向与建议:黄土区非点源污染物流失机理,非点源污染负荷估算方法,流域水、沙、污染物耦合模型以及3S 技术与流域非点源污染防控决策耦合应用等。

  7. A dual-inexact fuzzy stochastic model for water resources management and non-point source pollution mitigation under multiple uncertainties

    Science.gov (United States)

    Dong, C.; Tan, Q.; Huang, G.-H.; Cai, Y.-P.

    2014-05-01

    In this research, a dual-inexact fuzzy stochastic programming (DIFSP) method was developed for supporting the planning of water and farmland use management system considering the non-point source pollution mitigation under uncertainty. The random boundary interval (RBI) was incorporated into DIFSP through integrating fuzzy linear programming (FLP) and chance-constrained programming (CCP) approaches within an interval linear programming (ILP) framework. This developed method could effectively tackle the uncertainties expressed as intervals and fuzzy sets. Moreover, the lower and upper bounds of RBI are continuous random variables, and the correlation existing between the lower and upper bounds can be tackled in RBI through the joint probability distribution function. And thus the subjectivity of decision making is greatly reduced, enhancing the stability and robustness of obtained solutions. The proposed method was then applied to solve a water and farmland use planning model (WFUPM) with non-point source pollution mitigation. The generated results could provide decision makers with detailed water supply-demand schemes involving diversified water-related activities under preferred satisfaction degrees. These useful solutions could allow more in-depth analyses of the trade-offs between humans and environment, as well as those between system optimality and reliability. In addition, comparative analyses on the solutions obtained from ICCP (Interval chance-constraints programming) and DIFSP demonstrated the higher application of this developed approach for supporting the water and farmland use system planning.

  8. 河流污染的点源和非点源负荷分割研究%The Segmentation of the Point Source and Non-point Source Pollution Load of Rivers

    Institute of Scientific and Technical Information of China (English)

    乔继平; 代俊峰

    2015-01-01

    Non-point source pollution has become the major source of pollution of water environment .Point source pollution and non-point source pollution of river water environmental monitoring to distinguish sections is very necessary .This paper mainly intro‐duces the research progress at home and abroad about non point source pollution .This paper focuses on the pollution load partition of Nanliu River Basin in Guangxi Beibu Gulf Economic Zone .The segmentation of point source pollution and non-point source pollution of potassium permanganate index ,total phosphorus and ammonia nitrogen are made based on the hydrological estimation method and the digital filtering method .The hydrological estimation method results show that three indexes of non-point source pollution the to‐tal pollution load ratio is 0 .77 ,0 .74 and 0 .76 .And the digital filtering method results show that they are 0 .59 ,0 .64 and 0 .66 .Di‐viding two methods of non-point source is close to the result ,Nanliu River Basin is more serious .%非点源污染已经成为水环境的主要污染源,区分河流水环境监测断面的点源污染与非点源污染显得十分必要。以广西入海河流南流江为研究背景,采用数字滤波法和水文估算法进行点源与非点源污染负荷的分割。分析结果显示,基于水文估算法计算的2003-2011年多年平均高锰酸盐指数、总磷、氨氮的非点源污染负荷占总负荷的比例分别为0.77、0.74、0.76;采用数字滤波法计算的2003-2011年多年平均高锰酸盐指数、总磷、氨氮的非点源污染负荷占总负荷的比例分别为0.59、0.64、0.66。结果表明,两种方法分割的非点源结果的变幅趋势相同,南流江的非点源污染在总污染负荷中的比例较高。

  9. Controlling Agricultural Nonpoint Pollution through Developing Organic Agriculture%发展有机农业 控制农业面源污染

    Institute of Scientific and Technical Information of China (English)

    张纪兵; 席运官; 肖兴基

    2011-01-01

    Aiming at the current status of agricultural nonpoint pollution in China, the feasibility of controlling agricultural nonpoint pollution through developing organic agriculture was evaluated. Several countermeasures were suggested to promote the environmental strategy of developing organic agriculture to control agricultural nonpoint pollution, including making up national action plan of development of organic agriculture, enacting economic policies to extend organic agriculture, reinforcing scientific research on organic agriculture to control agricultural nonpoint pollution, creating key organic agricultural production technology relying on innovation of science and technology, boosting organic agriculture development through rural environment protection projects, and strengthening domestic market of organic food.%文章针对我国农业面源污染的现状,分析了发展有机农业,控制农业面源污染的可行性,并提出了推动有机农业控制农业面源污染的环境战略,包括制订有机农业发展的国家行动计划;建立激励有机农业发展的经济机制;加大对有机农业控制农业面源污染的科学研究;依靠科技创新建立有机农业生产关键技术;以农村环境保护工作为突破口,推动有机农业的发展;加大对国内有机食品市场的培育等。

  10. Combination system of full-scale constructed wetlands and wetland paddy fields to remove nitrogen and phosphorus from rural unregulated non-point sources.

    Science.gov (United States)

    Sun, Haijun; Zhang, Hailin; Yu, Zhimin; Wu, Jiasen; Jiang, Peikun; Yuan, Xiaoyan; Shi, Weiming

    2013-12-01

    Constructed wetlands (CWs) have been used effectively to remove nitrogen (N) and phosphorus (P) from non-point sources. Effluents of some CWs were, however, still with high N and P concentrations and remained to be pollution sources. Widely distributed paddy fields can be exploited to alleviate this concern. We were the first to investigate a combination system of three-level CWs with wetland paddy fields in a full scale to remove N and P from rural unregulated non-point sources. The removal efficiencies (REs) of CWs reached 57.3 % (37.4-75.1 %) for N and 76.3 % (62.0-98.4 %) for P. The CWs retained about 1,278 kg N ha(-1) year(-1) and 121 kg P ha(-1) year(-1). There was a notable seasonal change in REs of N and P, and the REs were different in different processing components of CWs. The removal rates of wetland paddy fields adopt "zero-drainage" water management according to local rainfall forecast and physiological water demand of crop growth reached 93.2 kg N ha(-1) year(-1) and 5.4 kg P ha(-1) year(-1). The rice season had higher potential in removing N and P than that in the wheat season. The whole combined system (0.56 ha CWs and 5.5 ha wetland paddy fields) removed 1,790 kg N year(-1) and 151 kg P year(-1), which were higher than those from CWs functioned alone. However, another 4.7-ha paddy fields were needed to fully remove the N and P in the effluents of CWs. The combination of CWs and paddy fields proved to be a more efficient nutrient removal system.

  11. Environmental Kuznets Curve Analysis of the Economic Development and Nonpoint Source Pollution in the Ningxia Yellow River Irrigation Districts in China

    Directory of Open Access Journals (Sweden)

    Chunlan Mao

    2013-01-01

    Full Text Available This study applies the environmental Kuznets curve to test the relationship between the regional economic growth and the different types of agricultural nonpoint source pollution loads in the Ningxia Yellow River irrigation area by using the Johnes export coefficient method. Results show that the pollution load generated by crop cultivation and livestock-breeding industries in the Ningxia Yellow River irrigation area shows an inverted U-shaped feature; however, this feature is absent in living-sewage pollution load. Crop pollution has shown a decreasing trend since 1997 because of the increased per capita income of farmers. Livestock-breeding pollution load reached its turning point when the per capita income of farmers reached 8386.74 RMB. Therefore, an increase in the per capita income of farmers corresponds to an increase in the livestock-breeding pollution load in the Ningxia Yellow River irrigation area.

  12. Environmental Kuznets curve analysis of the economic development and nonpoint source pollution in the Ningxia Yellow River irrigation districts in China.

    Science.gov (United States)

    Mao, Chunlan; Zhai, Ningning; Yang, Jingchao; Feng, Yongzhong; Cao, Yanchun; Han, Xinhui; Ren, Guangxin; Yang, Gaihe; Meng, Qing-xiang

    2013-01-01

    This study applies the environmental Kuznets curve to test the relationship between the regional economic growth and the different types of agricultural nonpoint source pollution loads in the Ningxia Yellow River irrigation area by using the Johnes export coefficient method. Results show that the pollution load generated by crop cultivation and livestock-breeding industries in the Ningxia Yellow River irrigation area shows an inverted U-shaped feature; however, this feature is absent in living-sewage pollution load. Crop pollution has shown a decreasing trend since 1997 because of the increased per capita income of farmers. Livestock-breeding pollution load reached its turning point when the per capita income of farmers reached 8386.74 RMB. Therefore, an increase in the per capita income of farmers corresponds to an increase in the livestock-breeding pollution load in the Ningxia Yellow River irrigation area.

  13. Linking monitoring and modelling for river basin management:Danish experience with combating nutrient loadings to the aquatic environment from point and non-point sources

    Institute of Scientific and Technical Information of China (English)

    KRONVANG; Brian; WINDOLF; JФrgen; GRANT; Ruth; ANDERSEN; Hans; E; THODSEN; Hans; OVESEN; Niels; B; LARSEN; SФren; E

    2009-01-01

    Nationwide monitoring of the aquatic environment was initiated in 1988 in Denmark as a means to follow the outcome of the Action Plans for nutrient pollution of the aquatic environment. Five Action Plans have been adopted by the Danish Parliament since 1985 and the nationwide monitoring programme can be used to quantify the outcome as shown by reductions in nutrient discharges from both point and non-point sources. Moreover, the empirical experience gathered from nearly 20 years of monitoring is assisting the development and calibration of models for simulation of nitrogen leaching, nitrogen removal in groundwater and surface waters and the establishment of a P-index all covering the entire land area of Denmark.

  14. Linking monitoring and modelling for river basin man-agement: Danish experience with combating nutrient loadings to the aquatic environment from point and non-point sources

    Institute of Scientific and Technical Information of China (English)

    KRONVANG Brian; WINDOLF J(φ)rgen; GRANT Ruth; ANDERSEN Hans E; THODSEN Hans; OVESEN Niels B; LARSEN S(φ)ren E

    2009-01-01

    Nationwide monitoring of the aquatic environment was initiated in 1988 in Denmark as a means to fol-low the outcome of the Action Plans for nutrient pollution of the aquatic environment.Five Action Plans have been adopted by the Danish Parliament since 1985 and the nationwide monitoring programme can be used to quantify the outcome as shown by reductions in nutrient discharges from both point and non-point sources.Moreover, the empirical experience gathered from nearly 20 years of monitoring is assisting the development and calibration of models for simulation of nitrogen leaching, nitrogen re-moval in groundwater and surface waters and the establishment of a P-index all covering the entire land area of Denmark.

  15. Environmental Kuznets Curve Analysis of the Economic Development and Nonpoint Source Pollution in the Ningxia Yellow River Irrigation Districts in China

    Science.gov (United States)

    Mao, Chunlan; Zhai, Ningning; Yang, Jingchao; Feng, Yongzhong; Cao, Yanchun; Han, Xinhui; Ren, Guangxin; Yang, Gaihe; Meng, Qing-xiang

    2013-01-01

    This study applies the environmental Kuznets curve to test the relationship between the regional economic growth and the different types of agricultural nonpoint source pollution loads in the Ningxia Yellow River irrigation area by using the Johnes export coefficient method. Results show that the pollution load generated by crop cultivation and livestock-breeding industries in the Ningxia Yellow River irrigation area shows an inverted U-shaped feature; however, this feature is absent in living-sewage pollution load. Crop pollution has shown a decreasing trend since 1997 because of the increased per capita income of farmers. Livestock-breeding pollution load reached its turning point when the per capita income of farmers reached 8386.74 RMB. Therefore, an increase in the per capita income of farmers corresponds to an increase in the livestock-breeding pollution load in the Ningxia Yellow River irrigation area. PMID:24171160

  16. Investigation on Present Xingtai Agricultural Non-point Source Pollution and Preventive Countermeasures%邢台市农业面源污染现状及防治对策

    Institute of Scientific and Technical Information of China (English)

    陈计兵

    2014-01-01

    Xingtai has a large population, with a serious contradiction between demand for food and land supply. The development of agriculture has brought about some pollution, and agricultural non-point source pollution prevention and control is the basic guarantee to realize agricultural sustainable development. Xingtai agricultural non-point source pollution is serious. The pollutants mainly include chemical fertilizer, chemical pesticide, agricultural plastic films, livestock and poultry breeding wastes and life wastes. The pollution has caused the decrease of the farmland quality, the degradation of the quality of agricultural products and water, the damage of the ecological balance. The countermeasures include technical measures, management measures, publicity and education measures, etc.%邢台市人口数量大、粮食需求、土地供给矛盾突出,在农业发展中,产生了一些不可忽视的污染现象,而农业面源污染的防治是实现农业可持续发展的基本保障。邢台市农业面源污染比较严重,污染源主要包括化学肥料污染、化学农药污染、农膜污染、畜禽养殖业污染和生活废弃物污染;污染带来耕地质量下降、农产品和水质质量变差、破坏生态平衡等危害;防治对策包括技术措施、管理措施及宣传教育措施等。

  17. [Analysis on nitrogen and phosphorus loading of non-point sources in Shiqiao river watershed based on L-THIA model].

    Science.gov (United States)

    Li, Kai; Zeng, Fan-Tang; Fang, Huai-Yang; Lin, Shu

    2013-11-01

    Based on the Long-term Hydrological Impact Assessment (L-THIA) model, the effect of land use and rainfall change on nitrogen and phosphorus loading of non-point sources in Shiqiao river watershed was analyzed. The parameters in L-THIA model were revised according to the data recorded in the scene of runoff plots, which were set up in the watershed. The results showed that the distribution of areas with high pollution load was mainly concentrated in agricultural land and urban land. Agricultural land was the biggest contributor to nitrogen and phosphorus load. From 1995 to 2010, the load of major pollutants, namely TN and TP, showed an obviously increasing trend with increase rates of 17.91% and 25.30%, respectively. With the urbanization in the watershed, urban land increased rapidly and its area proportion reached 43.94%. The contribution of urban land to nitrogen and phosphorus load was over 40% in 2010. This was the main reason why pollution load still increased obviously while the agricultural land decreased greatly in the past 15 years. The rainfall occurred in the watershed was mainly concentrated in the flood season, so the nitrogen and phosphorus load of the flood season was far higher than that of the non-flood season and the proportion accounting for the whole year was over 85%. Pearson regression analysis between pollution load and the frequency of different patterns of rainfall demonstrated that rainfall exceeding 20 mm in a day was the main rainfall type causing non-point source pollution.

  18. Assessing the Hydrologic Performance of the EPA's Nonpoint Source Water Quality Assessment Decision Support Tool Using North American Land Data Assimilation System (Products)

    Science.gov (United States)

    Lee, S.; Ni-Meister, W.; Toll, D.; Nigro, J.; Guiterrez-Magness, A.; Engman, T.

    2010-01-01

    The accuracy of streamflow predictions in the EPA's BASINS (Better Assessment Science Integrating Point and Nonpoint Sources) decision support tool is affected by the sparse meteorological data contained in BASINS. The North American Land Data Assimilation System (NLDAS) data with high spatial and temporal resolutions provide an alternative to the NOAA National Climatic Data Center (NCDC)'s station data. This study assessed the improvement of streamflow prediction of the Hydrological Simulation Program-FORTRAN (HSPF) model contained within BASINS using the NLDAS 118 degree hourly precipitation and evapotranspiration estimates in seven watersheds of the Chesapeake Bay region. Our results demonstrated consistent improvements of daily streamflow predictions in five of the seven watersheds when NLDAS precipitation and evapotranspiration data was incorporated into BASINS. The improvement of using the NLDAS data is significant when watershed's meteorological station is either far away or not in a similar climatic region. When the station is nearby, using the NLDAS data produces similar results. The correlation coefficients of the analyses using the NLDAS data were greater than 0.8, the Nash-Sutcliffe (NS) model fit efficiency greater than 0.6, and the error in the water balance was less than 5%. Our analyses also showed that the streamflow improvements were mainly contributed by the NLDAS's precipitation data and that the improvement from using NLDAS's evapotranspiration data was not significant; partially due to the constraints of current BASINS-HSPF settings. However, NLDAS's evapotranspiration data did improve the baseflow prediction. This study demonstrates the NLDAS data has the potential to improve stream flow predictions, thus aid the water quality assessment in the EPA nonpoint water quality assessment decision tool.

  19. SWAT模型在洱海流域面源污染评价中的应用%Application of SWAT Model in Agricultural Non-Point Source Pollution Investigation in Lake Erhai Watershed

    Institute of Scientific and Technical Information of China (English)

    翟玥; 尚晓; 沈剑; 王欣泽

    2012-01-01

    重点污染区域和污染因子的识别是面源污染控制的基础.通过将物理过程模拟及排污系数法计算进行整合,建立了SWAT模型,以描述农业生产活动与污染入湖量之间的关联关系,并以云南洱海流域总氮污染为例,使用验证后的SWAT模型模拟计算不同空间单元和不同农业生产活动对入湖TN的污染贡献系数,定量分析流域内各区域的农业面源污染源结构,识别洱海流域重点农业污染源和农业污染村镇.结果表明,奶牛养殖、生猪养殖和大蒜种植是目前洱海流域内入湖TN污染的最重要农业污染源,占流域总污染负荷的66.12%.对入湖TN污染贡献最大的6个村镇为江尾、右所、三营、玉湖、凤仪和喜洲,占流域总污染负荷的63.41%.%The identification of key polluted areas and factors is the basis of non-point source pollution control. Based on physical processes simulation and the discharge coefficient method, the SWAT model was established to describe the relationship between agricultural production activities and pollution load into a lake. Lake Erhai watershed in Yunnan province was selected as the research area, and TN variation in the lake was calculated. The contribution coefficients of TN nonpoint source pollution to the lake by different spatial areas and different agricultural production activities were calculated with the verified SWAT model, and the pollution source composition in each spatial unit was calculated quantitatively. The key pollution sources and Bpatial units ( administrative village in this study) were identified. The results showed that dairy cattle breeding, pig farming and garlic planting were the major agricultural pollution sources, contributing 66.12% of TN load to the lake. Six villages - Jiangwei, Yousuo, Sanying, Yuhu, Fengyi and Xizhou - contributed most to TN pollution in the lake, accounting for 63.41% of the watershed total pollution load.

  20. Past leaded gasoline emissions as a nonpoint source tracer in riparian systems: A study of river inputs to San Francisco Bay

    Science.gov (United States)

    Dunlap, C.E.; Bouse, R.; Flegal, A.R.

    2000-01-01

    Variations in the isotopic composition of lead in 1995-1998 river waters flowing into San Francisco Bay trace the washout of lead deposited in the drainage basin from leaded gasoline combustion. At the confluence of the Sacramento and San Joaquin rivers where they enter the Bay, the isotopic compositions of lead in the waters define a linear trend away from the measured historical compositions of leaded gas in California. The river waters are shifted away from leaded gasoline values and toward an isotopic composition similar to Sierra Nevadan inputs which became the predominant source of sedimentation in San Francisco Bay following the onset of hydraulic gold mining in 1853. Using lead isotopic compositions of hydraulic mine sediments and average leaded gasoline as mixing end members, we calculate that more than 50% of the lead in the present river water originated from leaded gasoline combustion. The strong adsorption of lead (log K(d) > 7.4) to particulates appears to limit the flushing of gasoline lead from the drainage basin, and the removal of that lead from the system may have reached an asymptotic limit. Consequently, gasoline lead isotopes should prove to be a useful nonpoint source tracer of the environmental distribution of particle- reactive anthropogenic metals in freshwater systems.

  1. Spatial-temporal characteristics of phosphorus in non-point source pollution with grid-based export coefficient model and geographical information system.

    Science.gov (United States)

    Liu, Ruimin; Dong, Guangxia; Xu, Fei; Wang, Xiujuan; He, Mengchang

    2015-01-01

    In this paper, the spatial changes and trends in non-point source (NPS) total phosphorus (TP) pollution were analyzed by land and non-land uses in the Songliao River Basin from 1986 to 2000 (14 years). A grid-based export coefficient model was used in the process of analysis based on to a geographic information system. The Songliao Basin is divided in four regions: Liaoning province, Jilin province (JL), Heilongjiang province and the eastern part of the Inner Mongolia (IM) Autonomous Region. Results indicated that the NPS phosphorus load caused by land use and non-land use increased steadily from 3.11×10(4) tons in 1986 to 3.49×10(4) tons in 2000. The southeastern region of the Songliao Plain was the most important NPS pollution contributor of all the districts. Although the TP load caused by land use decreased during the studied period in the Songliao River Basin, the contribution of land use to the TP load was dominant compared to non-land uses. The NPS pollution caused by non-land use steadily increased over the studied period. The IM Autonomous Region and JL province had the largest mean annual rate of change among all districts (more than 30%). In this area, livestock and poultry breeding had become one of the most important NPS pollution sources. These areas will need close attention in the future.

  2. Status of Agricultural Non-point Source Pollu-tion in China and Com-prehensive Treatment%我国农业面源污染现状及综合治理

    Institute of Scientific and Technical Information of China (English)

    李晓俐

    2015-01-01

    Agricultural non-point source pollution is worsening in China, mainly due to excessive and irrational use of pesticides, excessive use of fertil-izers, plastic sheeting pollution, straw pollution, intensive breeding farms pol-lution,etc. Agricultural non-point source pollution is harmful to water, atmosphere and soil,so the comprehensive treatment measures were put forward.%我国农业面源污染日益严重,主要原因是过量且不合理地使用农药,过量使用化肥,农膜污染、秸秆污染、集约化养殖场污染等。农业面源污染对水体、大气、土壤等造成严重危害,故提出综合治理措施。

  3. Relations of nonpoint-source nitrate and atrazine concentrations in the High Plains aquifer to selected explanatory variables in six Nebraska study areas

    Science.gov (United States)

    Druliner, A.D.; Chen, H.H.; McGrath, T.S.

    1996-01-01

    Statistical techniques were used to relate nonpoint-source ground-water contamination by nitrate and atrazine to a variety of explanatory variables for six study areas in Nebraska. Water samples were collected from 268 wells in 12 counties from 1984 through 1987 and were analyzed for nitrate concentrations; water samples from 210 of the wells were analyzed for atrazine. A number of hydrochemical, climatic, hydrologic, soil, and land-use explanatory variables, which were believed to affect the contamination of ground water by agricultural chemicals, were identified and quantified for each of the 268 wells. Multiple regression methods were used to determine which explanatory variables were statistically related to ground-water concentrations of nitrate and atrazine. Regression models predicting nitrate and atrazine concentrations were produced that explained from about 50 to 68 percent of the variation in the dependent variables. Geographic- information-system methods were used to produce maps predicting nitrate and atrazine concentrations in ground water for one study area using selected regression and logistic models. The results of this study indicate that multiple regression techniques coupled with geographic information systems can be an effective means of identifying areas of potential ground-water contamination by nitrate and atrazine.

  4. Using SWAT to Assess the Critical Areas and Nonpoint Source Pollution Reduction Best Management Practices in Lam Takong River Basin, Thailand

    Directory of Open Access Journals (Sweden)

    Netnapa Pongpetch

    2015-01-01

    Full Text Available Hydrological models are essential tools for water resource and nonpoint source pollution management. This study aimed to evaluate critical areas and best management practices (BMPs of sediment and nutrient loads in Lam Takong River basin, Northeastern Thailand, using SWAT (Soil and Water Assessment Tool model. The model was calibrated and validated using daily data of streamflow, sediment, NO3-N and TP in Lam Takong River from 2007-2008 and 2009, respectively. In general, the simulated streamflow and sediment were in reasonable agreement with the measured values with coefficient of determination (R2 and Nash-Sutcliffe model efficiency coefficient (NSE greater than 0.50 and the percent bias (PBIAS less than 25%. Additionally, nutrient loads showed a fair relationship between observation and simulation with R2 values more than 0.6 and PBIAS values less than 25%. From simulation, September was the month with the highest sediment, NO3-N and TP yields while January and December were the lowest months. From the model, SWAT identified 1 severe and 1 high soil erosion subbasins. Two subbasins were classified into medium loading for NO3-N. However, 9 subbasins were classified into high loading rate of TP. For BMPs, the 30-mwide filter strip was the best scenario reducing 100% of both sediment and TP, and 97.27% of NO3-N. These results could be a useful tool for water resources managements and soil conservation planning in Lam Takong River basin.

  5. Evaluating the Effects of Land Use Planning for Non-Point Source Pollution Based on a System Dynamics Approach in China.

    Science.gov (United States)

    Kuai, Peng; Li, Wei; Liu, Nianfeng

    2015-01-01

    Urbanization is proceeding rapidly in several developing countries such as China. This accelerating urbanization alters the existing land use types in a way that results in more Non-Point Source (NPS) pollution to local surface waters. Reasonable land use planning is necessary. This paper compares seven planning scenarios of a case study area, namely Wulijie, China, from the perspective of NPS pollution. A System Dynamics (SD) model was built for the comparison to adequately capture the planning complexity. These planning scenarios, which were developed by combining different land use intensities (LUIs) and construction speeds (CSs), were then simulated. The results show that compared to scenario S1 (business as usual) all other scenarios will introduce more NPS pollution (with an incremental rate of 22%-70%) to Wulijie. Scenario S6 was selected as the best because it induced relatively less NPS pollution while simultaneously maintaining a considerable development rate. Although LUIs represent a more critical factor compared to CSs, we conclude that both LUIs and CSs need to be taken into account to make the planning more environmentally friendly. Considering the power of SD in decision support, it is recommended that land use planning should take into consideration findings acquired from SD simulations.

  6. {sup 37}Cl, {sup 15}N, {sup 13}C isotopic analysis of common agro-chemicals for identifying non-point source agricultural contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Annable, W.K. [Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)]. E-mail: wkannabl@uwaterloo.ca; Frape, S.K. [Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Shouakar-Stash, O. [Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Shanoff, T. [Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Drimmie, R.J. [Department of Earth Sciences, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada); Harvey, F.E. [School of Natural Resources, University of Nebraska, Lincoln, NE 68588-0517 (United States)

    2007-07-15

    The isotopic compositions of commercially available herbicides were analyzed to determine their respective {sup 15}N, {sup 13}C and {sup 37}Cl signatures for the purposes of developing a discrete tool for tracing and identifying non-point source contaminants in agricultural watersheds. Findings demonstrate that of the agrochemicals evaluated, chlorine stable isotopes signatures range between {delta}{sup 37}Cl = -4.55 per mille and +3.40 per mille , whereas most naturally occurring chlorine stable isotopes signatures, including those of road salt, sewage sludge and fertilizers, vary in a narrow range about the Standard Mean Ocean Chloride (SMOC) between -2.00 per mille and +1.00 per mille . Nitrogen stable isotope values varied widely from {delta}{sup 15}N = -10.86 per mille to +1.44 per mille and carbon stable isotope analysis gave an observed range between {delta}{sup 13}C = -37.13 per mille and -21.35 per mille for the entire suite of agro-chemicals analyzed. When nitrogen, carbon and chlorine stable isotope analyses were compared in a cross-correlation analysis, statistically independent isotopic signatures exist suggesting a new potential tracer tool for identifying herbicides in the environment.

  7. Comparative study on nutrient removal of agricultural non-point source pollution for three filter media filling schemes in eco-soil reactors.

    Science.gov (United States)

    Du, Fuyi; Xie, Qingjie; Fang, Longxiang; Su, Hang

    2016-08-01

    Nutrients (nitrogen and phosphorus) from agricultural non-point source (NPS) pollution have been increasingly recognized as a major contributor to the deterioration of water quality in recent years. The purpose of this article is to investigate the discrepancies in interception of nutrients in agricultural NPS pollution for eco-soil reactors using different filling schemes. Parallel eco-soil reactors of laboratory scale were created and filled with filter media, such as grit, zeolite, limestone, and gravel. Three filling schemes were adopted: increasing-sized filling (I-filling), decreasing-sized filling (D-filling), and blend-sized filling (B-filling). The systems were intermittent operations via simulated rainstorm runoff. The nutrient removal efficiency, biomass accumulation and vertical dissolved oxygen (DO) distribution were defined to assess the performance of eco-soil. The results showed that B-filling reactor presented an ideal DO for partial nitrification-denitrification across the eco-soil, and B-filling was the most stable in the change of bio-film accumulation trends with depth in the three fillings. Simultaneous and highest removals of NH4(+)-N (57.74-70.52%), total nitrogen (43.69-54.50%), and total phosphorus (42.50-55.00%) were obtained in the B-filling, demonstrating the efficiency of the blend filling schemes of eco-soil for oxygen transfer and biomass accumulation to cope with agricultural NPS pollution.

  8. Sensitivity analysis of non-point sources in a water quality model applied to a dammed low-flow-reach river.

    Science.gov (United States)

    Silva, Nayana G M; von Sperling, Marcos

    2008-01-01

    Downstream of Capim Branco I hydroelectric dam (Minas Gerais state, Brazil), there is the need of keeping a minimum flow of 7 m3/s. This low flow reach (LFR) has a length of 9 km. In order to raise the water level in the low flow reach, the construction of intermediate dikes along the river bed was decided. The LFR has a tributary that receives the discharge of treated wastewater. As part of this study, water quality of the low-flow reach was modelled, in order to gain insight into its possible behaviour under different scenarios (without and with intermediate dikes). QUAL2E equations were implemented in FORTRAN code. The model takes into account point-source pollution and diffuse pollution. Uncertainty analysis was performed, presenting probabilistic results and allowing identification of the more important coefficients in the LFR water-quality model. The simulated results indicate, in general, very good conditions for most of the water quality parameters The variables of more influence found in the sensitivity analysis were the conversion coefficients (without and with dikes), the initial conditions in the reach (without dikes), the non-point incremental contributions (without dikes) and the hydraulic characteristics of the reach (with dikes).

  9. Non-Point Source Pollutant Load Variation in Rapid Urbanization Areas by Remote Sensing, Gis and the L-THIA Model: A Case in Bao'an District, Shenzhen, China

    Science.gov (United States)

    Li, Tianhong; Bai, Fengjiao; Han, Peng; Zhang, Yuanyan

    2016-11-01

    Urban sprawl is a major driving force that alters local and regional hydrology and increases non-point source pollution. Using the Bao'an District in Shenzhen, China, a typical rapid urbanization area, as the study area and land-use change maps from 1988 to 2014 that were obtained by remote sensing, the contributions of different land-use types to NPS pollutant production were assessed with a localized long-term hydrologic impact assessment (L-THIA) model. The results show that the non-point source pollution load changed significantly both in terms of magnitude and spatial distribution. The loads of chemical oxygen demand, total suspended substances, total nitrogen and total phosphorus were affected by the interactions between event mean concentration and the magnitude of changes in land-use acreages and the spatial distribution. From 1988 to 2014, the loads of chemical oxygen demand, suspended substances and total phosphorus showed clearly increasing trends with rates of 132.48 %, 32.52 % and 38.76 %, respectively, while the load of total nitrogen decreased by 71.52 %. The immigrant population ratio was selected as an indicator to represent the level of rapid urbanization and industrialization in the study area, and a comparison analysis of the indicator with the four non-point source loads demonstrated that the chemical oxygen demand, total phosphorus and total nitrogen loads are linearly related to the immigrant population ratio. The results provide useful information for environmental improvement and city management in the study area.

  10. Research on Nonpoint Source Pollution Assessment Method in Data Sparse Regions: A Case Study of Xichong River Basin, China

    Directory of Open Access Journals (Sweden)

    Xing Liu

    2015-01-01

    Full Text Available The NPS pollution is difficult to manage and control due to its complicated generation and formation mechanism, especially in the data sparse area. Thus the ECM and BTOPMC were, respectively, adopted to develop an easy and practical assessment method, and a comparison between the outputs of them is then conducted in this paper. The literature survey and field data were acquired to confirm the export coefficients of the ECM, and the loads of TN and TP were statistically analyzed in the study area. Based on hydrological similarity, runoff data from nearby gauged sites were pooled to compensate for the lack of at-site data and the water quality submodel of BTOPMC was then applied to simulate the monthly pollutant fluxes in the two sections from 2010 to 2012. The results showed agricultural fertilizer, rural sewage, and livestock and poultry sewage were the main pollution sources, and under the consideration of self-purification capacity of river, the outputs of the two models were almost identical. The proposed method with a main thought of combining and comparing an empirical model and a mechanistic model can assess the water quality conditions in the study area scientifically, which indicated it has a good potential for popularization in other regions.

  11. 模拟排水沟渠非点源溶质氮迁移实验研究%Transformation of Non-point Source Soluble Nitrogen in Simulated Drainage Ditch

    Institute of Scientific and Technical Information of China (English)

    李强坤; 宋常吉; 胡亚伟; 彭聪; 马强; 姜正曦; 琚艺萌

    2016-01-01

    The drainage ditch has a compound ecosystem structure consisting of water, sediment and plants. Migration and transformation of the non-point source solute is important to study interception, control and management of agricultural non-point source pollution in the drainage ditch. Based on the experiment on static simulation of drainage ditches, the article used typical non-point source soluble nitrogen as an example to analyze the changing process of nitrogen content in water, sediment and reeds, and to study the effects of the sediment adsorption and desorption, reeds growth and death in different periods on nitrogen concentration in water. The article discussed nitrogen migration in water-sediment- reeds compound ecosystem and its influence on nitrogen concentration in water. The results showed that both adsorption and desorption in sediment and absorption and assimilation of reeds growth had effect on nitrogen concentration in water. The effect before October was reducing the nitrogen concentration in water, which was the process of nitrogen purification in water. After October, the nitrogen concentration in water increased and made it easy to form secondary nitrogen pollution. Meanwhile, the migration in the water-sediment-seeds ecosystem in simulated drainage ditch had close ties, any migration and transformation of nitrogen in a single medium or between different mediums would cause adjustment of nitrogen concentration in water.%农田排水沟渠是由水-底泥-植物组成的复合生态结构,其间非点源溶质的迁移转化对研究沟渠拦截、控制和管理农业非点源污染具有重要意义。本研究以模拟排水沟渠静态实验为基础,以典型非点源溶质氮素为例,分析了实验期内水体、底泥及芦苇不同介质内氮含量变化过程,分析了底泥吸附与解析、芦苇生长与衰败等年内不同时期对水体中氮素浓度的影响,探讨了水-底泥-芦苇复合生态体内氮迁移及对水体中氮

  12. “双重失灵”视角下我国农业面源污染的法律规制%Legal Regulation of the Agricultural Non-point Source Pollution in the Perspective of “Double Failure”

    Institute of Scientific and Technical Information of China (English)

    祝创杰

    2016-01-01

    来自化肥、农药、农膜、畜禽养殖等污染源的农业面源污染已经成为我国水污染的最大污染源。现行立法对农业面源污染的规制在指导思想、具体内容和立法技术等方面仍存在一些不足,而这些不足又是忽略或缺乏经济法的思维方式所致。我国农业面源污染恶化是市场失灵和政府失灵共同作用的结果。克服“双重失灵”,有效规制面源污染,可以通过完善环境税收体系,增设生态税、建立排污权交易制度等经济法的调整手段实现。%The Agricultural Non-point Source Pollution (ANPSP),which is caused by pollution source like chemical fertilizers,pesticides,agricultural film and livestock breeding,has already be-come the largest source of pollution of our country's water pollution.The regulation of The Agricultural Non-point Source Pollution given by current legislation still has some deficiencies in guiding ideology, concrete content and legislative technique.This is caused by neglecting or lacking the thinking mode of economic law.The root cause of the deterioration of The Agricultural Non-point Source Pollution in China is the combined action of market failure and government failure.The task of overcoming “double failure”and controlling The Agricultural Non-point Source Pollution can be finished by using adjust-ment methods of economic law.The methods may include improving the environmental tax system, adding ecological taxation and establishing emission trading system.

  13. Effects of nonpoint and selected point contaminant sources on stream-water quality and relation to land use in Johnson County, northeastern Kansas, October 2002 through June 2004

    Science.gov (United States)

    Lee, Casey J.; Mau, D.P.; Rasmussen, T.J.

    2005-01-01

    Water and sediment samples were collected by the U.S. Geological Survey in 12 watersheds in Johnson County, northeastern Kansas, to determine the effects of nonpoint and selected point contaminant sources on stream-water quality and their relation to varying land use. The streams studied were located in urban areas of the county (Brush, Dykes Branch, Indian, Tomahawk, and Turkey Creeks), developing areas of the county (Blue River and Mill Creek), and in more rural areas of the county (Big Bull, Captain, Cedar, Kill, and Little Bull Creeks). Two base-flow synoptic surveys (73 total samples) were conducted in 11 watersheds, a minimum of three stormflow samples were collected in each of six watersheds, and 15 streambed-sediment sites were sampled in nine watersheds from October 2002 through June 2004. Discharge from seven wastewater treatment facilities (WWTFs) were sampled during base-flow synoptic surveys. Discharge from these facilities comprised greater than 50 percent of streamflow at the farthest downstream sampling site in six of the seven watersheds during base-flow conditions. Nutrients, organic wastewater-indicator compounds, and prescription and nonprescription pharmaceutical compounds generally were found in the largest concentrations during base-flow conditions at sites at, or immediately downstream from, point-source discharges from WWTFs. Downstream from WWTF discharges streamflow conditions were generally stable, whereas nutrient and wastewater-indicator compound concentrations decreased in samples from sites farther downstream. During base-flow conditions, sites upstream from WWTF discharges had significantly larger fecal coliform and Escherichia coli densities than downstream sites. Stormflow samples had the largest suspended-sediment concentrations and indicator bacteria densities. Other than in samples from sites in proximity to WWTF discharges, stormflow samples generally had the largest nutrient concentrations in Johnson County streams. Discharge

  14. Non-pointSource Pollution Control Policy under the Perspective of Experimental Economics:A Review%实验经济学视角下的非点源污染控制政策研究:一个文献综述

    Institute of Scientific and Technical Information of China (English)

    Wu Dan; Zhang weiwen

    2015-01-01

    Non-point source pollution has become an important source of water pollution for many countries including China. Used for the design and evaluation of non-point pollution control policy recently,experimental economics has made remarkable achievements in this field. In contrast,related research has not been published in China so far. This paper tries to anatomize and conclude the experimental economics on non-point source control policy by summarizing it as two categories,that is,individual -performance -based and collective -performance -based, from which some enlightenment are obtained and some preliminary research ideas are put forward.

  15. Study on agricultural structure and non-point source pollution: a case in Dapu Town of Yixing City

    Institute of Scientific and Technical Information of China (English)

    Jiang Dongmei; Wang Xiyuan; Liu Minghui; Lu Genfa

    2006-01-01

    The water body of Taihu Lake has been eutrophicated because of area-source pollution. 83% of the total nitrogen and 84% of the total phosphorus of the pollutant that have washed into Taihu Lake originated from the fertilizer of crop land, rural animal husbandry and living sewage and rubbish in rural area. The goal of adjusting agricultural structure is to improve agricultural development, and to increase the peasants income by planting non-grain crop,centralizing animal husbandry, and intensifying aquaculture, etc, It is necessary to research on the influences of agriculture industrial structure on area-source pollution, This paper studies a case of Dapu Town in Yixing City, which is a typical drainage place beside Taihu Lake. On the basis of the analysis on the status quo of area-source pollution and agriculture industrial structure in Dapu Town, the conflicts between them are discussed. Non-grain crop production with a great deal of fertilizer and developing aquaculture with a great deal of organic pollutant, which are directly discharged,make area-source pollution more serious and accelerate the eutrophication in Taihu Lake. This paper suggests taking corresponding technological measures and policies, which have been tested in Dapu Town and demonstrated in Taihu Lake area.

  16. 潮河流域非点源污染关键区识别及其管理措施研究%IDENTIFICATION OF NON-POINT SOURCE POLLUTION AND ASSESSMENT OF MANAGEMENT MEASURES IN THE CHAO RIVER BASIN

    Institute of Scientific and Technical Information of China (English)

    唐芳芳; 徐宗学; 徐华山

    2012-01-01

    选取SWAT模型,对潮河流域径流、泥沙及非点源污染过程进行模拟.在对模型进行率定和验证的基础上,参照土壤侵蚀模数与国家地表水环境质量标准对土壤侵蚀及总氮污染关键区进行识别.最后分别在土壤侵蚀和总氮污染关键区设置污染控制情景,对控制措施成效进行模拟和评价.结果表明,SWAT模型可以较好地模拟潮河流域水文过程和污染物迁移转化过程;流域20.9%的区域为轻度土壤侵蚀区,39.8%的区域为总氮风险区;梯田、等高耕作、退耕还林还草和减少化肥施用量等措施都不同程度地对非点源污染负荷起到一定的削减效果.%Chao River basin is one of the most important surface water sources for drinking water in Beijing.In recent years,the Chao River basin is facing water scarcity and water quality problem due to the impact of human activities,development of local economy and climate change.The Chao River basin was selected as the study area in this investigation.SWAT model was applied to simulate hydrological cycle and process of nutrient movements and transformation in the Chao River basin.Then critical source areas of soil erosion were identified according to soil erosion modulus,and critical source areas of TN concentration were identified based on the National Environmental Quality Standards for Surface Water.Finally,several scenarios to control non-point source pollution on critical source areas of soil erosion and TN concentration were proposed.Data showed that the performance of calibration and validation for runoff,sediments and nutrients were satisfactory.Mild soil erosion area was 1260.657 km2,accounting for 20.9% of the total basin area,while critical source area of TN was 2405.1 km2,accounting for 39.8% of the total area.Data also showed that the measures including terraces,contour farming,turning farm into forest and grasslands and fertilizer reduction played different reduction role on controlling

  17. Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps associated with uranium exploration and mining, Browns Hole, Utah

    Science.gov (United States)

    Marston, Thomas M.; Beisner, Kimberly R.; Naftz, David L.; Snyder, Terry

    2012-01-01

    During August of 2008, 35 solid-phase samples were collected from abandoned uranium waste dumps, undisturbed geologic background sites, and adjacent streambeds in Browns Hole in southeastern Utah. The objectives of this sampling program were (1) to assess impacts on human health due to exposure to radium, uranium, and thorium during recreational activities on and around uranium waste dumps on Bureau of Land Management lands; (2) to compare concentrations of trace elements associated with mine waste dumps to natural background concentrations; (3) to assess the nonpoint source chemical loading potential to ephemeral and perennial watersheds from uranium waste dumps; and (4) to assess contamination from waste dumps to the local perennial stream water in Muleshoe Creek. Uranium waste dump samples were collected using solid-phase sampling protocols. Solid samples were digested and analyzed for major and trace elements. Analytical values for radium and uranium in digested samples were compared to multiple soil screening levels developed from annual dosage calculations in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act's minimum cleanup guidelines for uranium waste sites. Three occupancy durations for sites were considered: 4.6 days per year, 7.0 days per year, and 14.0 days per year. None of the sites exceeded the radium soil screening level of 96 picocuries per gram, corresponding to a 4.6 days per year exposure. Two sites exceeded the radium soil screening level of 66 picocuries per gram, corresponding to a 7.0 days per year exposure. Seven sites exceeded the radium soil screening level of 33 picocuries per gram, corresponding to a 14.0 days per year exposure. A perennial stream that flows next to the toe of a uranium waste dump was sampled, analyzed for major and trace elements, and compared with existing aquatic-life and drinking-water-quality standards. None of the water-quality standards were exceeded in the stream samples.

  18. Trends of nitrogen and phosphorus input into Lake Neusiedl from wastewater treatment plants and non-point sources

    Science.gov (United States)

    Kinner, Paul; Heiss, Gerhard; Soja, Gerhard

    2013-04-01

    nitrogen load amounted to 304 tons in 2010, compared to 47 tons in 2001. In the period 1992-2010 the nitrogen load caused by diffuse sources was 4.3 times higher than the point source nitrogen load (2 wastewater treatment plants). The proportion of total discharge, of inorganic nitrogen load and of phosphorus load caused by the two wastewater treatment plants depended on the discharge rate of the river Wulka (monitoring station Schützen). In 2001 (low precipitation year: 578 mm annual sum) point sources contributed about 47% of the discharge, 51% of the nitrogen load and 65% of the phosphorus load of the river Wulka. In 2010 (high precipitation year: 945 mm annual sum) point sources contributed 25% of the discharge, 11% of the nitrogen load and 31% of the total phosphorus load. In the period 1992 to 2010 the inorganic nitrogen load caused by surface water (Wulka, WWTP, creeks and channels) varied from 65 t/a to 675 t/a (mean:233 t/a).

  19. Seasonal change of non-point source pollution-induced bioavailable phosphorus loss: A case study of Southwestern China

    Science.gov (United States)

    Gao, Yang; Zhu, Bo; Wang, Tao; Wang, Yafeng

    2012-02-01

    SummaryBioavailable phosphorus (P) losses due to agriculture activity in a purple soil watershed in the Sichuan Basin of Southwestern China were monitored to define the hydrological controls of P transport. Our results indicate that the proportion of P that was transported in particulate form increased in the rainy season, and that the mass of total bioavailable P (BAP) loads exhibited seasonal fluctuations, wherein the majority (over 90%) was observed to have been exported between June and September. The proportion of bioavailable dissolved P (BDP) in the BAP discharge budget in the watershed varied between 11% and 15% during the monitoring period. The bioavailable particulate P (BPP) and BDP concentrations of stream water under rainstorm events increased by over 40% in comparison to their annual mean concentrations, and the annual BAP load was primarily dominated by the loads that occurred during rainstorm events in the study year. BAP concentration in groundwater significantly fluctuated with the seasons, and the ratio of total BAP in groundwater to that in surface water gradually increased during the rainy season. Thus, the impact of agriculture on the water quality of this watershed becomes clearly evident.

  20. Non-Point Source Pollutant Load Variation in Rapid Urbanization Areas by Remote Sensing, Gis and the L-THIA Model: A Case in Bao'an District, Shenzhen, China.

    Science.gov (United States)

    Li, Tianhong; Bai, Fengjiao; Han, Peng; Zhang, Yuanyan

    2016-11-01

    Urban sprawl is a major driving force that alters local and regional hydrology and increases non-point source pollution. Using the Bao'an District in Shenzhen, China, a typical rapid urbanization area, as the study area and land-use change maps from 1988 to 2014 that were obtained by remote sensing, the contributions of different land-use types to NPS pollutant production were assessed with a localized long-term hydrologic impact assessment (L-THIA) model. The results show that the non-point source pollution load changed significantly both in terms of magnitude and spatial distribution. The loads of chemical oxygen demand, total suspended substances, total nitrogen and total phosphorus were affected by the interactions between event mean concentration and the magnitude of changes in land-use acreages and the spatial distribution. From 1988 to 2014, the loads of chemical oxygen demand, suspended substances and total phosphorus showed clearly increasing trends with rates of 132.48 %, 32.52 % and 38.76 %, respectively, while the load of total nitrogen decreased by 71.52 %. The immigrant population ratio was selected as an indicator to represent the level of rapid urbanization and industrialization in the study area, and a comparison analysis of the indicator with the four non-point source loads demonstrated that the chemical oxygen demand, total phosphorus and total nitrogen loads are linearly related to the immigrant population ratio. The results provide useful information for environmental improvement and city management in the study area.

  1. SWAT模型在大洋河流域非点源污染模拟中的运用研究%The application of the SWAT model in a non-point source pollution in the Dayang River basin

    Institute of Scientific and Technical Information of China (English)

    刘晓哲

    2015-01-01

    Based on the SWAT model to Ocean River watershed for the study, quantitative modeling of the ocean River 2000 - -2010 Pollution, the results show that non-point source: SWAT model is appropriate for non-point source pollu-tion ocean river basin model parameters of periodic and verification simulation of total nitrogen and total phosphorus relative er-ror is less than 30%, the simulation uncertainty factor of 0. 5 or more, to meet the non-point source pollution simulation ac-curacy; total nitrogen and total phosphorus peak ocean River mainly 7 - September. Research for Ocean River water environ-mental protection and governance provide a reference value.%基于SWAT模型,以大洋河流域为研究流域,定量模拟了大洋河流域2000 -2010 年非点源污染,研究结果表明:SWAT模型适合于大洋河流域的非点源污染模拟,模型在参数率定期和验证模拟总氮和总磷相对误差均小于30%,模拟确定性系数达到0. 5 以上,满足流域非点源污染模拟精度要求;大洋河流域总氮和总磷峰值主要集中在7 -9 月份. 研究成果对于大洋河流域水环境保护和治理提供参考价值.

  2. Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps associated with uranium exploration and mining, San Rafael Swell, Utah

    Science.gov (United States)

    Freeman, Michael L.; Naftz, David L.; Snyder, Terry; Johnson, Greg

    2008-01-01

    During July and August of 2006, 117 solid-phase samples were collected from abandoned uranium waste dumps, geologic background sites, and adjacent streambeds in the San Rafael Swell, in southeastern Utah. The objective of this sampling program was to assess the nonpoint source chemical loading potential to ephemeral and perennial watersheds from uranium waste dumps on Bureau of Land Management property. Uranium waste dump samples were collected using solid-phase sampling protocols. After collection, solid-phase samples were homogenized and extracted in the laboratory using a field leaching procedure. Filtered (0.45 micron) water samples were obtained from the field leaching procedure and were analyzed for Ag, As, Ba, Be, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, U, V, and Zn at the Inductively Coupled Plasma-Mass Spectrometry Metals Analysis Laboratory at the University of Utah, Salt Lake City, Utah and for Hg at the U.S. Geological Survey National Water Quality Laboratory, Denver, Colorado. For the initial ranking of chemical loading potential of suspect uranium waste dumps, leachate analyses were compared with existing aquatic life and drinking-water-quality standards and the ratio of samples that exceeded standards to the total number of samples was determined for each element having a water-quality standard for aquatic life and drinking-water. Approximately 56 percent (48/85) of the leachate samples extracted from uranium waste dumps had one or more chemical constituents that exceeded aquatic life and drinking-water-quality standards. Most of the uranium waste dump sites with elevated trace-element concentrations in leachates were along Reds Canyon Road between Tomsich Butte and Family Butte. Twelve of the uranium waste dump sites with elevated trace-element concentrations in leachates contained three or more constituents that exceeded drinking-water-quality standards. Eighteen of the uranium waste dump sites had three or more constituents that exceeded trace

  3. Spatial and temporal variability of heavy metals in streams of the Flint Creek and Flint River Watersheds from non-point sources

    OpenAIRE

    I. Abdi; T. Tsegaye; Silitonga, M.; Tadesse, W

    2009-01-01

    Throughout the United States, non-point pollution is responsible for large quantities of heavy metals entering bodies of water. Pollution as a result of heavy metals can impact drinking water supplies, recreation, fisheries, and aquatic species. Presence of heavy metals such as lead (Pb), cadmium (Cd), and chromium (Cr), in surface water may pose great risks to human health as well as to aquatic animals. In order to understand water quality changes due to heavy metal element...

  4. The urban atmosphere as a non-point source for the transport of MTBE and other volatile organic compounds (VOCS) to shallow groundwater

    Science.gov (United States)

    Pankow, J.F.; Thomson, N.R.; Johnson, R.L.; Baehr, A.L.; Zogorski, J.S.

    1997-01-01

    all no- net recharge cases. The mechanism responsible for this effect was the dispersion acting on each downward infiltration event, and also on the ET-induced flow. The ability of MTBE to reach groundwater in cases 2-5 is taken as evidence of the potential importance of urban air as a non-point source for VOCs in shallow urban groundwater. Two subcases were run for both case 4 and case 5: subcase a (water and VOCs move with ET) and subcase b (water only moves with ET).Numerical simulations were conducted using a 1-D model domain set in medium sand to provide a test of whether methyl-tert-butyl ether (MTBE) and other atmospheric volatile organic compounds could move to shallow groundwater within the 10-15 y time frame over which MTBE was used in large amounts. The gasoline additive MTBE is of special interest because of its: current levels in some urban air; strong partitioning from air into water; resistance to degradation; use as an octane-booster since the 1970s; rapidly increasing use in the 1990s to reduce CO and O3 in urban air; and its frequent detection at low microgram per liter levels in shallow urban groundwater.

  5. Calculation and discussion of non-point source pollution loads in Danjiangkou Reservoir Area%丹江口水库入库非点源污染负荷的计算与讨论

    Institute of Scientific and Technical Information of China (English)

    郑艳霞; 程超; 辛小康

    2015-01-01

    正确估算丹江口水库入库非点源污染负荷对于水源区水环境保护具有重要意义. 根据丹江口库区6条主要入库河流汉江、天河、堵河、丹江、老灌河、淇河控制水文站2013年逐日流量数据,采用数字滤波法对基流进行了分割. 以逐日流量、河川基流量和代表污染物(CODMn和TP)2013年逐月浓度监测值为基础,采用通量法计算了背景污染负荷和点源污染负荷、非点源污染负荷. 结果表明:(1) 6条河流入库流量占总入库流量的95. 9%,非点源污染已成为丹江口水库水质变化的主导因素. (2) 汉江是入库污染负荷的最大来源,其次是堵河. (3) 由于非点源污染伴随降雨汇入河道,水库污染负荷主要集中于丰水期,2013年度丰水期CODMn和TP的比例分别达到了80. 8%和90. 9%.%Correctly estimating the non-point source pollution loads in Danjiangkou Reservoir Area is important to the envi-ronmental protection of the water source area. The Digital Filter method is used to separate the base flows of Hanjiang River, Tianhe River, Duhe River, Danjiang River, Laoguan River and Qihe River in the reservoir basin according to the daily discharge data. Based on the daily flow, the base flow and monthly typical pollutant concentration in 2013, a flux model is set up to calcu-late the background pollution loads, point-source pollution loads and non-point source pollution loads respectively. The calcu-lation results show that in 2013, the inflow discharge of the 6 rivers accounted for 95. 9% of the total inflow, and the total pollu-tion loads of CODMn and TP from the 6 rivers are 58. 2 thousand t and 1. 86 thousand t, while the non-point source pollution loads are 39. 82 thousand t and 1. 544 thousand t, so the non-point source pollution is the decisive factor;Hanjiang River is the largest pollutants contributor to Danjiangkou Reservoir and followed by Duhe River; the non-point source pollution enters into the river channel

  6. Watershed Management Tool for Selection and Spacial Allocation of Non-Point Source Pollution Control Practices

    Science.gov (United States)

    Distributed-parameter watershed models are often utilized for evaluating the effectiveness of sediment and nutrient abatement strategies through the traditional {calibrate→ validate→ predict} approach. The applicability of the method is limited due to modeling approximations. In ...

  7. Spatial and temporal variability of heavy metals in streams of the Flint Creek and Flint River Watersheds from non-point sources

    OpenAIRE

    Tadesse, W; Silitonga, M.; I. Abdi; T. Tsegaye

    2009-01-01

    Throughout the United States, non-point pollution is responsible for large quantities of heavy metals entering bodies of water. Pollution as a result of heavy metals can impact drinking water supplies, recreation, fisheries, and aquatic species. Presence of heavy metals such as lead (Pb), cadmium (Cd), and chromium (Cr), in surface water may pose great risks to human health as well as to aquatic animals. In order to understand water quality changes due to heavy metal elements and pH as a resu...

  8. Hydrogeology and Water Quality of the Pepacton Reservoir Watershed in Southeastern New York. Part 3. Responses of Stream Base-Flow Chemistry to Hydrogeologic Factors and Nonpoint-Sources of Contamination

    Science.gov (United States)

    Heisig, Paul M.; Phillips, Patrick J.

    2004-01-01

    Base-flow samples were collected seasonally from 20 small streams in the 372-square-mile Pepacton Reservoir watershed to evaluate the effects of hydrogeologic factors and nonpoint sources of contamination on the chemical composition of ground-water discharge. The reservoir provides part of New York City?s water supply. The subbasins represented one of three general types of land use, each with at least 45 percent forested area (mostly on the hillsides): farmed (dairy) land, formerly farmed land with low-density residential development, or forested land with little or no development. The subbasin areas ranged from 0.38 to 10.23 square miles. All streams were sampled in December 2000 and in May, July, and October 2001. Three of the sites were designated as landuse- index sites and were sampled as many as five additional times during the study. No samples exceeded state or federal drinking-water standards for chloride, sodium, nitrate, orthophosphate, herbicides, or herbicide degradates. The chemical composition of base-flow samples was classified into major-ion water types, which were broadly defined as naturally occurring and road-salt-affected water types. About one-third of the base-flow samples were roadsalt- affected types. Natural water types were differentiated as dilute or evolved. Dilute waters have bicarbonate and sulfate as dominant anions and evolved waters have only bicarbonate as a dominant anion. Dilute water types indicate relatively short ground-water residence times or contact with unreactive aquifer material. Evolved waters have either longer ground-water residence time or contact with more reactive aquifer material than dilute ground waters. The larger subbasins with wider valley-bottom areas were more likely to have evolved water types than small subbasins with little floodplain development. Positive correlations between selected constituents and the intensity of nonpoint sources emphasize the connection between land use, shallow ground

  9. 国内外遥感技术在非点源污染模拟中的应用%Application of Remote Sensing Technology in Non-point Source Pollution Monitoring

    Institute of Scientific and Technical Information of China (English)

    王天培

    2011-01-01

    综述了遥感技术在土壤类型和性质、植被类型和性质、水文气象以及土地利用等直接影响非点源污染产生的因素中的应用,以期为模型模拟与遥感技术联合研究非点源污染提供借鉴.%The application of remote sensing technology on the main factors, including soil types and properties, characteristics of vegetation,hydrological process, meteorological information, land use and so on were discussed in this paper so as to provide references for using modelsimulation and remote sensing technology to study the non-point source pollution.

  10. Source Apportionment of Non-point Source Nitrogen Pollution in Ashi River Basin Usingδ15N Technique%阿什河流域非点源氮污染的δ15N源解析研究

    Institute of Scientific and Technical Information of China (English)

    胡钰; 王业耀; 滕彦国; 香宝; 马广文; 方广玲

    2015-01-01

    crop farming on water nitro-gen pollution were dependent on river water seasonal periods and farming cycles. During the normal water period, non-point nitrogen pollu-tion by crop farming occurred mainly in the midstream and downstream sections, with δ15N value ranging from 0.46%to 0.77%. The pollu-tion sources were primarily artificial chemical fertilizers and farmland water recession. During the high water period, the pollution from non-point nitrogen extended to the upstream area, withδ15N range of 0.19%~0.4%. The main pollution source was artificial chemical fertilizers in the upstream area, while it was soil organic nitrogen via soil erosion caused by rainfall and irrigation in the midstream and downstream. Dur-ing the low water period, however, artificial chemical fertilizers were still the main contributor of non-point nitrogen pollution, with δ15N val-ues of 0.11%to 0.39%. This was resulted from the feedback of the nitrite-nitrogen from artificial chemical fertilizers that were applied and infiltrated in the ground during the monsoon.

  11. Nitrogen Non-Point Source Pollution Identification Based on ArcSWAT in Changle River%基于ArcSWAT模型的长乐江流域非点源氮素污染源识别和分析

    Institute of Scientific and Technical Information of China (English)

    邓欧平; 孙嗣旸; 吕军

    2013-01-01

    The ArcSWAT (Soil and Water Assessment Tool) model was adopted for Non-point source ( NPS) nitrogen pollution modeling and nitrogen source apportionment for the Changle River watershed, a typical agricultural watershed in Southeast China. Water quality and hydrological parameters were monitored, and the watershed natural conditions (including soil, climate, land use, etc) and pollution sources information were also investigated and collected for SWAT database. The ArcSWAT model was established in the Changle River after the calibrating and validating procedures of the model parameters. Based on the validated SWAT model, the contributions of different nitrogen sources to river TN loading were quantified, and spatial-temporal distributions of NPS nitrogen export to rivers were addressed. The results showed that in the Changle River watershed, Nitrogen fertilizer, nitrogen air deposition and nitrogen soil pool were the prominent pollution sources, which contributed 35% , 32% and 25% to the river TN loading, respectively. There were spatial-temporal variations in the critical sources for NPS TN export to the river. Natural sources, such as soil nitrogen pool and atmospheric nitrogen deposition, should be targeted as the critical sources for river TN pollution during the rainy seasons. Chemical nitrogen fertilizer application should be targeted as the critical sources for river TN pollution during the crop growing season. Chemical nitrogen fertilizer application, soil nitrogen pool and atmospheric nitrogen deposition were the main sources for TN exported from the garden plot, forest and residential land, respectively. However, they were the main sources for TN exported both from the upland and paddy field. These results revealed that NPS pollution controlling rules should focus on the spatio-temporal distribution of NPS pollution sources.%本研究以我国东南沿海地区的典型农业流域——长乐江流域为对象,通过实地调查、数据收集和分析,

  12. Application of SWMM in the Simulation of Non-Point Source Pollution Load in Urban Residential Area%SWMM模型应用于城市住宅区非点源污染负荷模拟计算

    Institute of Scientific and Technical Information of China (English)

    马晓宇; 朱元励; 梅琨; 张艳军; 张明华

    2012-01-01

    This study was focused on the non-point source pollution loading in a typical urban residential area in Wenzhou City, Zhejiang Province. Based on the SWMM principle, parameters from the literature and field experiments were integrated, and a non-point source pollution calibration model was constructed. Four different rainfall scenarios were designed to analyze the pollution loads and the accumulation process of total suspended solids (TSS) , chemical oxygen demand (CODCr) , total nitrogen (TN) and total phosphorus ( TP). The results showed that the simulated data matched the field-monitored data satisfactorily. The relative errors between the simulated and the true values of all the four parameters were less than 10%. Under' the four rainfall conditions: 1) the highest concentrations of the pollutants were observed within 30-40 minutes; the heavier the rain, the earlier their highest concentrations appeared; 2) higher-intensity rainfall caused more serious pollution to the receiving water bodies than the low-intensity rainfall did.%以温州市典型住宅区非点源污染为对象,基于SWMM(storm water management model)模型的模拟机理,借鉴国内外相关研究的模型参数,结合降雨径流实测数据率定模型参数,将模型“本地化”,构建了基于SWMM模型的研究区非点源污染负荷计算模型,并设计了4种不同降雨情景,分析在不同降雨条件下研究区非点源污染固体悬浮物(TSS)、CODCr、TN和TP的污染负荷量及其累积变化过程.结果表明,构建的SWMM模型的模拟值可以较好地与实测值相吻合,4种污染物模拟的相对误差均小于10%.在设计的4种降雨情景下:①污染物浓度峰值出现在降雨30~40 min内,降雨强度越大,出现浓度峰值的时间越早;②高强度降雨较低强度降雨可对受纳水体造成更大的污染.

  13. 流域非点源污染景观源汇格局遥感解析%Remote sensing parsing on non-point pollution landscape source and assembly pattern in river basin

    Institute of Scientific and Technical Information of China (English)

    张新; 程熙; 李万庆; 罗雷

    2014-01-01

    流域非点源污染景观源汇格局解析是流域水质污染物产生、输运机理认知与有效防治措施制定的重要科学理论基础。该文以充分挖掘流域遥感数据多时空尺度的特征与优势为目标,制定了流域非点源污染景观源汇类型界定方案,提出了像元级、亚像元级以及时序更新的流域非点源污染景观源汇格局遥感解析方法。在此基础上,以福建省九龙江流域为例,对不透水面这一典型流域非点源污染“源”景观2010年空间格局进行了信息提取,并对2000、2005年对应信息进行了时序更新与空间特征分析,结果显示2000-2010年间九龙江流域内不透水面覆盖面积增长了33.38%。该研究可为中国流域非点源污染研究、生态管理与建设提供参考。%The non-point pollution landscape source and assembly pattern of a river basin and its spatio-temporal process analysis are the scientific theoretical bases for studying the pollution, production, transport, prevention, and policy of river water. In this paper, to mine the spatio-temporal character and advantages of remote sensing data, the definition schedule of the landscape of the river basin non-point pollution source and assembly was introduced. The first types of landscape in the river basin included the impervious surface area (ISA) and the pervious surface area. The second types of landscapes in the river basin consisted of 14 different types, including woodland, orchard, road, rural area, town, and paddy field, etc. The river basin non-point pollution landscape source and assembly pattern remote sensing parsing method was subsequently presented at the pixel, sub-pixel, and time-renewing levels. (1) A “globe-local” coupling information extraction model for ISA at the pixel level was established. Through the mining and integration of the spatial information in a local image area, the spectral instability of the whole scale was optimized. The

  14. SIMULATION OF NON-POINT POLLUTANTS EVOLUTION IN COASTAL PLAIN ISLAND-A CASE STUDY OF CHONGMING ISLAND

    Institute of Scientific and Technical Information of China (English)

    YIN Hai-long; JIANG Wen-yan; LI Jian-hua

    2008-01-01

    The coastal plain region usually shows the agricultural dominated industry mode, so more and more attention is paid to non-point pollutants discharge. In this study, the method for assessing the influence of non-point pollutants discharge on river water quality is probed which is concluded as follows: (1) Considering the costal plain island is characterized as nearly even elevation, the conventional gravitational runoff confluence method based on eight-point gravitational flowing directions (D8) is unable to compute the runoff confluence received by the surrounding rivers, so a new method of triangular confluence based on three-points of grid center and the river segments is presented. Further the equations of non-point pollutants loads estimation and non-point pollutants confluence on rivers are presented. (2) The integration mode of non-point pollutants model and river water quality model is presented so as to further assess the non-point pollutants contribution to river water quality. (3) With the Chongming Island, the third largest island in China, as an example, the above-mentioned equations are specified. For this island, the non-point pollutants loads are estimated and linked to the developed water quality model of the river network in the island, and further the non-point pollution evolution in river network is simulated. In this scenario, the non-point pollution contribution to river water quality over the whole island is clearly displayed, and the area where the river water quality is seriously influenced by non-point pollutants discharge is distinctly depicted. This scenario also shows the water quality contribution ratio of non-point pollution to point pollution can be in the range of 55.5% to 44.5% which proves the importance of non-point pollution control in costal plain islands.

  15. Yield calculation of agricultural non-point source pollutants in Huntai River Basin based on SWAT model%基于SWAT模型的浑太河流域农业面源污染物产生量估算

    Institute of Scientific and Technical Information of China (English)

    付意成; 臧文斌; 董飞; 付敏; 张剑

    2016-01-01

    The establishment of non-point source pollutants output load model under the mode of rainfall-runoff and land use, the analog calculation of agricultural non-point source pollutants in the process of migration and transformation, and the systematic analysis of non-point source pollutants discharge quantity, distribution and composition characteristics are based on actual monitoring data, calibration and validation model, in consideration of underlying surface, hydrology and meteorology, and physical features of Huntai River basin. The areas 1 km away from each side of master stream Huntai River, Taizihe River and Daliaohe River and 5 km away from reservoir were defined as buffer zone, where the mode of land use was transformed so as to restore the natural ecosystem. The process of pollutant migration and conversion was simulated based on the calibration of key hydrological parameters, and the causes as well as the migratory features of non-point source pollution were investigated. The primary area of water environment pollution was mainly distributed along both sides of the water channel of the mainstreams of Huntai River. The point-source pollutant was mainly related to the distribution of industry and the amount of discharged wastewater. The risk of non-point pollution was mainly related to the pattern of agricultural plantation and farmland utilization. The secondary area of water environment pollution was mainly distributed along both sides of the water channel of tributaries. Therefore, the situation of pollutant production corresponding to the intra-regional regulation of industrial structure, land utilization pattern surrounding the water channel should be highlighted. The non-point pollution in Huntai watershed was dominated by farmland pollution, and the main indices of pollutants were total nitrogen (N) and total phosphorus (P). The contribution rate of pollutants was farmland runoff > livestock and poultry breeding > urban runoff > water and soil erosion

  16. Screening and identification of early warning algal species for metal contamination in fresh water bodies polluted from point and non-point sources.

    Science.gov (United States)

    Rai, U N; Dubey, Smita; Shukla, O P; Dwivedi, S; Tripathi, R D

    2008-09-01

    The water bodies of Lucknow, Unnao and Kanpur (U.P.), India polluted through various point and non point sources were found to be either eutrophic or oligotrophic in nature. These water bodies supported a great number of algal diversity, which varied seasonally depending upon the physico-chemical properties of water. Further, the water bodies polluted through non point sources supports diverse algal species, while the water bodies polluted through point sources supports growth of tolerant blue green algae. High biomass producing algal species growing in these water bodies have accumulated significant amount of metals in their tissues. Maximum amount of Fe was found accumulated by species of Oedogonium sp. II (20,523.00 microg g(-1) dw) and Spirogyra sp. I (4,520.00 microg g(-1) dw), while maximum Chromium (Cr) was found accumulated in Phormedium bohneri (2,109.00 microg g(-1) dw) followed by Oscillatoria nigra (1,957.88 microg g(-1) dw) and Oedogonium sp. I (156.00 microg g(-1) dw) and Ni in Ulothrix sp. (495.00 microg g(-1) dw). Results showed that some of these forms growing in polluted environment and accumulating high amounts of toxic metals may be used as bioindicator species, however, their performance in metal contaminated water under different ecological niche is to be ascertained.

  17. Spatial Quantification of Non-Point Source Pollution in a Meso-Scale Catchment for an Assessment of Buffer Zones Efficiency

    Directory of Open Access Journals (Sweden)

    Mikołaj Piniewski

    2015-04-01

    Full Text Available The objective of this paper was to spatially quantify diffuse pollution sources and estimate the potential efficiency of applying riparian buffer zones as a conservation practice for mitigating chemical pollutant losses. This study was conducted using a semi-distributed Soil and Water Assessment Tool (SWAT model that underwent extensive calibration and validation in the Sulejów Reservoir catchment (SRC, which occupies 4900 km2 in central Poland. The model was calibrated and validated against daily discharges (10 gauges, NO3-N and TP loads (7 gauges. Overall, the model generally performed well during the calibration period but not during the validation period for simulating discharge and loading of NO3-N and TP. Diffuse agricultural sources appeared to be the main contributors to the elevated NO3-N and TP loads in the streams. The existing, default representation of buffer zones in SWAT uses a VFS sub-model that only affects the contaminants present in surface runoff. The results of an extensive monitoring program carried out in 2011–2013 in the SRC suggest that buffer zones are highly efficient for reducing NO3-N and TP concentrations in shallow groundwater. On average, reductions of 56% and 76% were observed, respectively. An improved simulation of buffer zones in SWAT was achieved through empirical upscaling of the measurement results. The mean values of the sub-basin level reductions are 0.16 kg NO3/ha (5.9% and 0.03 kg TP/ha (19.4%. The buffer zones simulated using this approach contributed 24% for NO3-N and 54% for TP to the total achieved mean reduction at the sub-basin level. This result suggests that additional measures are needed to achieve acceptable water quality status in all water bodies of the SRC, despite the fact that the buffer zones have a high potential for reducing contaminant emissions.

  18. Spatial-temporal Variation of Agricultural Non-point Source Pollution Based on GIS Technology in Guangdong Province, China%基于GIS的广东省农业面源污染的时空分异研究

    Institute of Scientific and Technical Information of China (English)

    叶延琼; 章家恩; 李逸勉; 李韵; 吴睿珊

    2013-01-01

    近年来,广东省化肥、农药等农用化学品的投入量大增,农业面源污染问题日趋严重.采用历年统计数据以及GIS技术,对广东省农业面源污染的时空分异性进行了分析.结果表明,全省化肥、农药使用量均呈逐年增加态势,化肥使用量由1990年的162.41万t增加到2010年的237.29万t,农药由1990年的7.95万t增加到2010年的10.44万t.畜禽粪尿排放量则由2000年的339.34亿t减少到2010年的222.08亿t;在空间分布上,全省化肥投入强度超过400 kg· hm-2的县(市)由1995年的35个增加到2010年的61个,粤西、粤东全部,珠三角大部以及粤北部分地区均属化肥严重污染区,其原因主要在于对农作物产量增加的追求.农药投入强度超过30 kg· hm-2的县(市)由1995年的10个增加到2010年的27个,这主要是由于广东的气候条件及种植结构改变造成的.畜禽粪尿排放污染情况相对较好,但因粤西的雷州半岛地区以水稻生产为主,大牲畜牛的养殖规模较大,因此畜禽粪尿重度污染主要集中在这一地区.GIS空间分析的运用,能直观地反映各地区农业面源污染的时空动态变化情况,为有针对性地开展污染治理提供依据.%Agriculture non-point source pollution (ANSP) is becoming a serious environmental concern in Guangdong Province due to the increased applications of agricultural chemicals such as fertilizers and pesticides in recent years. This study investigated the spatial-temporal variation of ANSP using the historical statistical data and GIS technology. Results showed that the fertilizer, pesticide and other agrochemical applications in Guangdong Province were increased and reached quite a high level in order to secure food supply. The total amount of chemical fertilizer application increased from 1.62x1061 in 1990 to 2.73x1061 in 2010 and the total amount of pesticide application elevated from 7.95X1041 to 10.04X1041, while the total amount of animal manure

  19. A novel modelling framework to prioritize estimation of non-point source pollution parameters for quantifying pollutant origin and discharge in urban catchments.

    Science.gov (United States)

    Fraga, I; Charters, F J; O'Sullivan, A D; Cochrane, T A

    2016-02-01

    Stormwater runoff in urban catchments contains heavy metals (zinc, copper, lead) and suspended solids (TSS) which can substantially degrade urban waterways. To identify these pollutant sources and quantify their loads the MEDUSA (Modelled Estimates of Discharges for Urban Stormwater Assessments) modelling framework was developed. The model quantifies pollutant build-up and wash-off from individual impervious roof, road and car park surfaces for individual rain events, incorporating differences in pollutant dynamics between surface types and rainfall characteristics. This requires delineating all impervious surfaces and their material types, the drainage network, rainfall characteristics and coefficients for the pollutant dynamics equations. An example application of the model to a small urban catchment demonstrates how the model can be used to identify the magnitude of pollutant loads, their spatial origin and the response of the catchment to changes in specific rainfall characteristics. A sensitivity analysis then identifies the key parameters influencing each pollutant load within the stormwater given the catchment characteristics, which allows development of a targeted calibration process that will enhance the certainty of the model outputs, while minimizing the data collection required for effective calibration. A detailed explanation of the modelling framework and pre-calibration sensitivity analysis is presented.

  20. [Ecosystem service and economic valuation in the upper reaches of Xin' an River, Anhui, China for mitigating phosphorus nonpoint source pollution].

    Science.gov (United States)

    He, Fang; Wu, Nan; Fang, Xiang-long; Gao, Ji-xi; Zhou, Xiao-tie; Feng, Chao-yang

    2015-04-01

    A model of phosphorus purification in a watershed was established based on the export coefficient and purification index of phosphorus in different types of land cover. The model was employed to simulate the economic value of the ecosystem service with the expected water quality standard and marginal cost of pollutant purification of the upper reaches of Xin' an River of Anhui, China. The results revealed that from 2000 to 2010, some farmland outside the Tunxi, Jixi, Shexian, Yixian and Xiuning was converted to built-up land. The total amount of phosphorus exported to the upper Xin' an River decreased a little, and the main source of phosphorus pollution was farmland and built-up land. More than half of the exported phosphorus was efficiently purified by different types of land cover via flow accumulation. The pattern of purification and export of highly concentrated phosphorus showed the same trend which occurred in the northern part of the watershed including the Yangzhi River, Fengle River and Hengjiang River. Forestland and grassland did not efficiently purify phosphorus in the watershed owing to the irrational distribution of existing land cover. The total service value was 3.80 and 3.31 million Yuan in 2000 and 2010, respectively.

  1. Evaluation of Land Use, Land Management and Soil Conservation Strategies to Reduce Non-Point Source Pollution Loads in the Three Gorges Region, China.

    Science.gov (United States)

    Strehmel, Alexander; Schmalz, Britta; Fohrer, Nicola

    2016-11-01

    The construction of the Three Gorges Dam in China and the subsequent impoundment of the Yangtze River have induced a major land use change in the Three Gorges Reservoir Region, which fosters increased inputs of sediment and nutrients from diffuse sources into the water bodies. Several government programs have been implemented to mitigate high sediment and nutrient loads to the reservoir. However, institutional weaknesses and a focus on economic development have so far widely counteracted the effectiveness of these programs. In this study, the eco-hydrological model soil and water assessment tool is used to assess the effects of changes in fertilizer amounts and the conditions of bench terraces in the Xiangxi catchment in the Three Gorges Reservoir Region on diffuse matter releases. With this, the study aims at identifying efficient management measures, which should have priority. The results show that a reduction of fertilizer amounts cannot reduce phosphorus loads considerably without inhibiting crop productivity. The condition of terraces in the catchment has a strong impact on soil erosion and phosphorus releases from agricultural areas. Hence, if economically feasible, programmes focusing on the construction and maintenance of terraces in the region should be implemented. Additionally, intercropping on corn fields as well as more efficient fertilization schemes for agricultural land were identified as potential instruments to reduce diffuse matter loads further. While the study was carried out in the Three Gorges Region, its findings may also beneficial for the reduction of water pollution in other mountainous areas with strong agricultural use.

  2. Evaluation of Land Use, Land Management and Soil Conservation Strategies to Reduce Non-Point Source Pollution Loads in the Three Gorges Region, China

    Science.gov (United States)

    Strehmel, Alexander; Schmalz, Britta; Fohrer, Nicola

    2016-11-01

    The construction of the Three Gorges Dam in China and the subsequent impoundment of the Yangtze River have induced a major land use change in the Three Gorges Reservoir Region, which fosters increased inputs of sediment and nutrients from diffuse sources into the water bodies. Several government programs have been implemented to mitigate high sediment and nutrient loads to the reservoir. However, institutional weaknesses and a focus on economic development have so far widely counteracted the effectiveness of these programs. In this study, the eco-hydrological model soil and water assessment tool is used to assess the effects of changes in fertilizer amounts and the conditions of bench terraces in the Xiangxi catchment in the Three Gorges Reservoir Region on diffuse matter releases. With this, the study aims at identifying efficient management measures, which should have priority. The results show that a reduction of fertilizer amounts cannot reduce phosphorus loads considerably without inhibiting crop productivity. The condition of terraces in the catchment has a strong impact on soil erosion and phosphorus releases from agricultural areas. Hence, if economically feasible, programmes focusing on the construction and maintenance of terraces in the region should be implemented. Additionally, intercropping on corn fields as well as more efficient fertilization schemes for agricultural land were identified as potential instruments to reduce diffuse matter loads further. While the study was carried out in the Three Gorges Region, its findings may also beneficial for the reduction of water pollution in other mountainous areas with strong agricultural use.

  3. Agricultural nonpoint source pollution: prevention and estimate methods; L'inquinamento di origine agricola: quali strumenti di prevenzione e stima?

    Energy Technology Data Exchange (ETDEWEB)

    Caffarelli, V.; Rapagnani, M.R.; Triolo, L. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Innovazione

    1999-07-01

    Non point source pollutants, such as pesticides and fertilizers derived from agricultural activities, are recognized as an important threat to environment and human health. To prevent the adverse effects of these agrochemicals it is necessary to provide growers and decision makers with easy-to-use information. Attempts have been made to put information on pesticides environmental and health effects into a formula that could summarize, in a single number, these effects. However a single number could be misleading because of the lack of information on chemical-physical parameters and the difficulty to evaluate the relative importance of various environmental and health effects. As an alternative it is here proposed an approach based on schedule containing information, for each pesticides, such as short and long term effects on human health, environmental fate and degradation time, capacity to bio accumulate, toxicity of degradation products. Using information in the schedule, decision makers could make more circumstantiate choices and could program the best agricultural actions under particular environmental circumstances with less impact on man and environment. [Italian] L'inquinamento diffuso derivante dall'uso dei fertilizzanti e dei pesticidi in agricoltura, rappresenta un rischio rilevante per l'ambiente e la salute umana. Al fine di prevenire tale rischio e' necessario fornire a coloro che gestiscono e pianificano le attivita' agricole informazioni facilmente comprensibili, mirate a ridurre o eliminare gli effetti indesiderati derivanti dai prodotti agrochimici. Tentativi sono stati fatti per sviluppare metodologie che sintetizzino queste informazioni in un indice numerico in modo da stilare una graduatoria di pericolosita' dei singoli prodotti. Si propone, in questo lavoro, un approccio basato sulla elaborazione di schede, per ogni principio attivo, che contengono una serie di informazioni quali gli effetti a breve e lungo termine

  4. 宁夏农村面源污染现状调查分析结果初报%Preliminary Report on Investigation and Analysis Result of Current Situation of Rural Non-point Source Pol ution in Ningxia

    Institute of Scientific and Technical Information of China (English)

    杨晓娟; 靳军良; 王金保

    2014-01-01

    通过调查监测,宁夏农村面源污染的主要来源集中体现在化肥污染、农药污染、畜禽粪便污染、农膜污染及农村生活污染5个方面,但其影响和污染主要表现在对水环境和土壤环境的污染上。其中,对水环境的污染形式则是通过地表径流和地下淋溶把过剩的氮、磷、有机农药、无机盐等带到地表水和地下水中,致使地表水富营养化,破环水生态环境,鱼虾难以生存。对土壤环境的污染形式是通过农业投入品超量施入,在改变土壤物理性状、破环土壤通透性、造成土壤板结、粘结的同时,造成重金属离子和病原菌的积累,给农产品质量安全带来危害。%Based on an investigation and monitoring,the main sources of Ningxia rural non-point source pollution includes the five aspects of chemical fertilizer pollution, pesticide pollution, livestock and poultry manure pollution, agricultural plastic film pollution and rural domestic pollution. But the impact and pollution were mainly manifested in the pollution of water envi-ronment and soil environment. The form of pollution of the water environment was bringing excess nitrogen, phosphorus, or-ganic pesticides and inorganic salt to the surface water and underground water by the surface runoff and underground leach-ing,it caused the surface water eutrophication,the destruction of the aquatic ecological environment and made the fish and shrimp hard to survive. The form of pollution of the soil environment was changing the soil physical characteristic, destroying the soil permeability, causing soil compaction and bond,and causing the accumulation of heavy metal ions and pathogenic bacteria by excessive application of agricultural inputs, and it brought harms to the quality and safety of agricultural products.

  5. Calculation of Intercepted Volume of Sewer Overflows: a Model for Control of Nonpoint Pollution Sources in Urban Areas

    Institute of Scientific and Technical Information of China (English)

    S. C. Choi; D. I. Jung; C. H. Won; J. M. Rim

    2006-01-01

    The authors discovered large differences in the characteristics of overflows by the calculation of 1) intercepting volume of overflows for sewer systems using SWMM model which takes into consideration the runoff and pollutants from rainfalls and 2) the intercepted volume in the total flow at an investigation site. The intercepting rate at the investigation point of CSOs showed higher values than the SSDs. Based on the modeling of the receiving water quality after calculating the intercepting amount of overflows by considering the characteristics of outflows for a proper management of the overflow of sewer systems with rainfalls, it is clear that the BOD decreased by 82.9%-94.0% for the discharge after intercepting a specific amount of flows compared to the discharge from unprocessed overflows.

  6. Testing and modeling the influence of reclamation and control methods for reducing nonpoint mercury emissions associated with industrial open pit gold mines.

    Science.gov (United States)

    Miller, Matthieu B; Gustin, Mae S

    2013-06-01

    Industrial gold mining is a significant source of mercury (Hg) emission to the atmosphere. To investigate ways to reduce these emissions, reclamation and dust and mercury control methods used at open pit gold mining operations in Nevada were studied in a laboratory setting. Using this information along with field data, and building off previous work, total annual Hg emissions were estimated for two active gold mines in northern Nevada. Results showed that capping mining waste materials with a low-Hg substrate can reduce Hg emissions from 50 to nearly 100%. The spraying of typical dust control solutions often results in higher Hg emissions, especially as materials dry after application. The concentrated application of a dithiocarbamate Hg control reagent appears to reduce Hg emissions, but further testing mimicking the actual distribution of this chemical within an active leach solution is needed to make a more definitive assessment.

  7. Assessing the influence of different plant species in drainage ditches on mitigation of non-point source pollutants (N, P, and sediments) in the Purple Sichuan Basin.

    Science.gov (United States)

    Kumwimba, Mathieu Nsenga; Zhu, Bo; Muyembe, Diana Kavidia

    2017-06-01

    Three different types of ditches, each 300 m in length, were employed in this study. One vegetated constructed ditch (VCD), three natural vegetated soil ditches (NVSD), and three constructed ditches left unvegetated (UCD) as controls were investigated using simple in/out mass balances and uptake by plant species with a potential for phytoremediation and their mechanisms. Significant differences in the ditches were observed, suggesting the importance of plant species in nutrient mitigation. The removal rates of TN (total nitrogen) and TP (total phosphorus) were 64.28 and 58.02, 31.16 and 27.49, and 3.91 and 2.97%, respectively, in the VCD, NVSD, and UCD. Canna indica (45.12 g m(-2)) and Oenanthe javanica (21.48 g m(-2)) had the highest total N and P storage in the VCD and NVSD. Furthermore, species C. indica possessed the highest annual N and P uptake in the VCD (216.59 kg N/ha/yr and 30.73 kg P/ha/yr). In the NVSD, species O. javanica had the greatest annual N and P uptake (96.66 kg N/ha/yr and 7.94 kg P/ha/yr). Both VCD and NVSD were found to have a reasonably good outcome compared to UCD. Retention of nutrients by ditch sediments was probably the major attenuation mechanism, with subsequent plant uptake and microbial nitrification-denitrification of the nutrients as secondary removal mechanisms. Results of this study highlight the importance of taking actions for establishment of appropriate plant species inside the ditches in order to enhance its direct and indirect roles and maximize purification rate in aquatic environments.

  8. Nonpoint source pollution by swine farming wastewater in bean crop Poluição difusa da água residuária de suinocultura do feijoeiro

    Directory of Open Access Journals (Sweden)

    André F. Doblinski

    2010-01-01

    Full Text Available In order to verify the environmental impact of the application of swine farming wastewater in bean crop, an experiment was set up in the Experimental Farm of PUCPR - Toledo, PR, Brazil. Runoff and soil samples were collected at the end of the experiment. Four wastewater treatments were utilized during the experiment (50, 100, 150 and 200 m³ ha-1 and the without wastewater as the control. The results demonstrate that (i the amounts of potassium, phosphorus, and nitrogen in runoff are exponential, (ii that phosphorus has a seven-fold polluting potential compared to potassium and three-fold compared to nitrogen, and (iii that the mobility of potassium in the soil profile is the largest, followed by those of nitrogen and phosphorus.Visando verificar o impacto ambiental da aplicação de água residuária de suinocultura na cultura do feijoeiro, instalou-se um experimento na Fazenda Experimental da PUCPR - Toledo, PR, Brasil; para isto, amostras do solo e do escoamento superficial foram coletadas ao final do experimento e se utilizaram quatro taxas de aplicação de água residuária durante o experimento, 50, 100, 150 e 200 m³ ha-1, sem aplicação de água residuária como testemunha. Os resultados demonstraram que: (i as perdas de potássio, fósforo e nitrogênio no escoamento superficial são exponenciais; (ii o fósforo apresenta potencial poluidor sete vezes maior que o potássio e três vezes maior que o nitrogênio; (iii a mobilidade do potássio no perfil do solo é maior, seguida do nitrogênio e do fósforo.

  9. Advanced Light Source control system

    Energy Technology Data Exchange (ETDEWEB)

    Magyary, S.; Chin, M.; Cork, C.; Fahmie, M.; Lancaster, H.; Molinari, P.; Ritchie, A.; Robb, A.; Timossi, C.

    1989-03-01

    The Advanced Light Source (ALS) is a third generation 1--2 GeV synchrotron radiation source designed to provide ports for 60 beamlines. It uses a 50 MeV electron linac and 1.5 GeV, 1 Hz, booster synchrotron for injection into a 1--2 GeV storage ring. Interesting control problems are created because of the need for dynamic closed beam orbit control to eliminate interaction between the ring tuning requirements and to minimize orbit shifts due to ground vibrations. The extremely signal sensitive nature of the experiments requires special attention to the sources of electrical noise. These requirements have led to a control system design which emphasizes connectivity at the accelerator equipment end and a large I/O bandwidth for closed loop system response. Not overlooked are user friendliness, operator response time, modeling, and expert system provisions. Portable consoles are used for local operation of machine equipment. Our solution is a massively parallel system with >120 Mbits/sec I/O bandwidth and >1500 Mips computing power. At the equipment level connections are made using over 600 powerful Intelligent Local Controllers (ILC-s) mounted in 3U size Eurocard slots using fiber-optic cables between rack locations. In the control room, personal computers control and display all machine variables at a 10 Hz rate including the scope signals which are collected though the control system. Commercially available software and industry standards are used extensively. Particular attention is paid to reliability, maintainability and upgradeability. 10 refs., 11 figs.

  10. Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps and human health hazards associated with uranium exploration and mining, Red, White, and Fry Canyons, southeastern Utah, 2007

    Science.gov (United States)

    Beisner, Kimberly R.; Marston, Thomas M.; Naftz, David L.; Snyder, Terry; Freeman, Michael L.

    2010-01-01

    During May, June, and July 2007, 58 solid-phase samples were collected from abandoned uranium mine waste dumps, background sites, and adjacent streambeds in Red, White, and Fry Canyons in southeastern Utah. The objectives of this sampling program were to (1) assess the nonpoint-source chemical loading potential to ephemeral and perennial drainage basins from uranium waste dumps and (2) assess potential effects on human health due to recreational activities on and around uranium waste dumps on Bureau of Land Management property. Uranium waste-dump samples were collected using solid-phase sampling protocols. After collection, solid-phase samples were homogenized and extracted in the laboratory using a leaching procedure. Filtered (0.45 micron) water samples were obtained from the field leaching procedure and were analyzed for major and trace elements at the Inductively Coupled Plasma-Mass Spectrometry Metals Analysis Laboratory at the University of Utah. A subset of the solid-phase samples also were digested with strong acids and analyzed for major ions and trace elements at the U.S. Geological Survey Geologic Division Laboratory in Denver, Colorado. For the initial ranking of chemical loading potential for uranium waste dumps, results of leachate analyses were compared with existing aquatic-life and drinking-water-quality standards. To assess potential effects on human health, solid-phase digestion values for uranium were compared to soil screening levels (SSL) computed using the computer model RESRAD 6.5 for a probable concentration of radium. One or more chemical constituents exceeded aquatic life and drinking-water-quality standards in approximately 64 percent (29/45) of the leachate samples extracted from uranium waste dumps. Most of the uranium waste dump sites with elevated trace-element concentrations in leachates were located in Red Canyon. Approximately 69 percent (31/45) of the strong acid digestible soil concentration values were greater than a calculated

  11. Reduction rate of nitrogen and phosphorus non-point source pollution under different riparian buffer restoring strategies%不同河岸带修复策略对氮磷非点源污染的净化作用

    Institute of Scientific and Technical Information of China (English)

    赵鹏; 胡艳芳; 林峻宇

    2015-01-01

    This study was conducted along Liuxi River watershed, a main branch of Beijiang River, in Guangdong Province. Based on the non-point source (NPS) pollution and riparian buffer’s reduction in current situations of the Liuxi River Basin, the differences of NPS pollution reduction improvement of different restoration strategies were investigated by scenario simulations. In order to compare the efficiency of different restoration strategies, the relationships between the improvement of NPS reduction rate and the increase of buffer area were interpreted by benefit-cost index. The results showed the NPS reduction rate performed remarkable spatial variation. Each scenario had improved the NPS reduction rates to varying degrees (TN: 23.36%~30.72%; TP: 27.19%~39.86%). The relationships between buffer areas and NPS reduction rate of each scenario were fitted well by the logarithmic function (P<0.05). The strategy with restoring the sub-basins of prior riparian buffer restoration, which integrated NPS loading and riparian buffers conditions, could reach the best benefit-cost index (1.19%).%选择北江的重要支流流溪河流域为研究对象,基于现有河岸带对非点源污染削减作用的模拟结果,采用情景分析法,预测不同河岸带修复策略对非点源污染的削减作用,使用效益-成本指数表征 TN 和 TP 削减率提高幅度与增加河岸带面积的关系,比较不同河岸带修复策略的效率.结果表明:河岸带对TN和TP的削减能力具有较大的空间差异性.各修复情景都在不同程度上提高了河岸带对TN和TP的削减率(TN:23.36%~30.72%;TP:27.19%~39.86%),河岸带增加总面积与削减率呈现对数增长关系(P<0.05).选择综合考虑了流域非点源负荷量以及河岸带状况的优先修复子流域进行河岸带修复时,效益-成本指数达最高为1.19%.

  12. Estimation of nonpoint-source loads of total nitrogen, total phosphorous, and total suspended solids in the Black, Belle, and Pine River basins, Michigan, by use of the PLOAD model

    Science.gov (United States)

    Syed, Atiq U.; Jodoin, Richard S.

    2006-01-01

    The Lake St. Clair Regional Monitoring Project partners planned a 3-year assessment study of the surface water in the Lake St. Clair drainage basins in Michigan. This study included water-quality monitoring and analysis, collection of discrete (grab) and automatic water-quality samples, monitoring of bacteria, and the creation of a database to store all relevant data collected from past and future field-data-collection programs. In cooperation with the Lake St. Clair Monitoring Project, the U.S. Geological Survey assessed nonpoint-source loads of nutrients and total suspended solids in the Black, Belle, and Pine River basins. The principal tool for the assessment study was the USEPA’s PLOAD model, a simplified GIS-based numerical program that generates gross estimates of pollutant loads. In this study, annual loads were computed for each watershed using the USEPA’s Simple Method, which is based on scientific studies showing a correlation between different land-use types and loading rates. The two land-use data sets used in the study (representing 1992 and 2001) show a maximum of 0.02-percent change in any of the 15 land use categories between the two timeframes. This small change in land use is reflected in the PLOAD results of the study area between the two time periods. PLOAD model results for the 2001 land-use data include total-nitrogen loads from the Black, Belle, and Pine River basins of approximately 495,599 lb/yr, 156,561 lb/yr, and 121,212 lb/yr, respectively; total-phosphorus loads of 80,777 lb/yr, 25,493 lb/yr, and 19,655 lb/yr, respectively; and total-suspended-solids loads of 5,613,282 lb/yr, 1,831,045 lb/yr, and 1,480,352 lb/yr, respectively. The subbasins in the Black, Belle, and Pine River basin with comparatively high loads are characterized by comparatively high percentages of industrial, commercial, transportation, or residential land use. The results from the PLOAD model provide useful information about the approximate average annual loading

  13. A simple laboratory project for introducing nonpoint source pollution concept to students of environmental and agricultural related courses Uma experiência laboratorial simples para introduzir o conceito de poluição disseminada a estudantes das áreas do ambiente e agricultura

    Directory of Open Access Journals (Sweden)

    M.M. Vidal

    2009-01-01

    Full Text Available This paper reports a simple laboratory project to introduce students to the nonpoint source pollution, which may be an issue of great interest to both undergraduate and graduate students of environmental or agricultural chemistry courses. The aim of this work is introduce to the students the concepts and techniques such as the polymericbased controlled release system of an agrochemical, theory of diffusion (first Fick law and spectrophotometric analysis. Thus, this laboratory project includes three experimental modules to be conducted during three weeks. Programmatic contents are described in this proceeding. Students must be aware that dissemination of nutrients and pesticides is prone to occur by both surface runoff and groundwater leaching, causing damages on all neighboring land. To demonstrate dissemination of such pollutants, we have chosen inorganic phosphorus as example of a common agrochemical. Students are invited to follow the eventual movement of the inorganic P into the groundwater. With this purpose, gelatin gels containing inorganic P were prepared to obtain a continuous release of inorganic P at a controlled rate. The slow release of P allows fewer applications and less active ingredient needed, helping to prevent leaching, with consequent reduction of groundwater contamination. At this point, students are able to compare the advantages of slow release inorganic P vs. its application by conventional methods.Este trabalho descreve uma experiência laboratorial simples para introduzir o conceito de poluição disseminada (nonpoint source pollution a estudantes do Ensino Secundário e Universitário das áreas de Ambiente e de Agricultura. O objectivo deste trabalho é introduzir aos estudantes conceitos e técnicas, tais como os sistemas de libertação controlada, a teoria da difusão (1ª lei de Fick e a análise espectrofotomética. Este projecto laboratorial inclui três módulos experimentais a serem efectuados durante 3

  14. 基于排水过程分析的水稻灌区农田面源污染模拟%Simulation of agricultural non-point source pollution from paddy rice irrigation district based on analyses of drainage processes

    Institute of Scientific and Technical Information of China (English)

    陈会; 王康; 周祖昊

    2012-01-01

    对前郭灌区主要面源污染物迁移、转化及汇集过程开展了2a的系统试验与监测,模拟了灌区面源污染水质水量过程,分析了灌区农田面源污染形成机制.水均衡测定结果表明,灌区排水主要由灌溉退水、稻田地表弃水和稻田渗流排水3部分组成,采用马斯京根法和连续分段马斯京根法能够有效地模拟各级排水沟道的排水过程.主要面源污染物随水体发生迁移及掺混,采用一级动力学方法描述污染物转化过程,模拟的灌区水质水量过程与实际过程符合较好,稻田地表退水主要影响水稻抽穗前的面源污染入河过程,而渗流排水则在抽穗后灌区排水水质中起主要作用.结果表明水稻灌区中地表排水和稻田渗漏排水对于面源污染过程起主要作用.%The transport and transformation processes of non-point source pollutions form paddy rice field to the main drainage canal through lateral and branch drainage canals were monitored in the Qianguo irrigation district during the rice growing seasons in 2009 and 2010. Water balance were measured in lateral canal in the controlled irrigation region. Results showed that the drainage water were composed of the rice field surface returned water, the irrigation returned water and the seepage from rice field to the drainage canals. Drainage processes in branch and main canal were simulated using the Muskingum method and the Muskingum segmentation flow routing method, respectively. The transport processes of chemical concentrations were determined by the mix and convection of water flow and the transformation processes were described using the first order kinetic equation. Drainage processes and contaminant concentration simulated showed good agreements with the measured values. The returned water and seepage from rice field played key roles in the process of agricultural non point pollution into the river. This research suggested the surface drainage and seepage

  15. 考虑面源污染的中国苹果全要素生产率及其空间集聚特征分析%Total factor productivity of apple industry in China considering non-point source pollution and its spatial concentration analysis

    Institute of Scientific and Technical Information of China (English)

    冯晓龙; 霍学喜

    2015-01-01

    Apple industry has become a major industry of rural economy in most of the north region in China, which plays an important role on the adjustment of agricultural structure, the increase of farmer’s income and the export. But overall, the development of apple industry still has belonged to the traditional production style depending on fertilizer and pesticide; on one side it has brought high economic benefits for farmers, and on the other side it has been the main reason to agricultural non-point source pollution. There is no doubt that this production style has exacerbated the contradiction between the development of apple industry and the ecological environment in China. Therefore, in order to achieve the sustainable development of apple industry, the transformation of the development mode of apple industry, the improvement of resource use efficiency and the effective control of non-point source pollution in apple production should be taken into account urgently. And to achieve these goals are closely dependent on the contribution of apple total factor productivity to industry development, the reasonable estimation of apple total factor productivity, and thus the guide of the correct policy. Using the unit investigation and evaluation model, this paper calculates the non-point source pollution from apple industry, which is taken as non-ideal output and integrated into the model of total factor productivity, then analyzes the total factor productivity of apple industry under the constraint of environment of 21 provinces in China from 1994 to 2013 by applying the Malmquist-Luenberger productivity index, and finally tests the spatial autocorrelation of total factor productivity of apple industry by using Moran’s index. The results show as follows: 1) Apple total factor productivity index under the constraint of environment is lower than that without this constraint, implying that environment pollution has obvious negative effects on apple productivity in China

  16. Control System of the H~- Ion Source

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The control system is of primary importance to the accelerator operation. This paper presents a brief introduction to the new ion source control system. The research is to build a new H- ion source based on

  17. On the applicability of SWAT model to the nonpoint source pollution in the watershed of the three-gorge reservoir%SWAT模型在三峡库区流域非点源污染模拟的适用性研究

    Institute of Scientific and Technical Information of China (English)

    陈媛; 郭秀锐; 程水源; 王征; 秦翠红; 陆瑾; 高继军

    2012-01-01

    This paper intends to study the applicability of SWAT model to the non-point Source pollution in the watershed of the Three-Gorge Reservoir. The so-called SWAT (Soil and Water Assessment Tool) model is a model we have developed in hoping to be applied and adapted to the macro-scale watershed, in the TGR area as a case study. The said model has been established under the support of the Geographic Information System (ArcGIS) as well as the spatial dataset such as DEM(digital elevation model), land-use map and so on. In our research, we have studied the data of hydrolngical and water quality in the TGR area from 2002 to 2008 for simulated calibration and validation. On the whole, our simulation proves to be successful, for the indicator ENS ( Nash-Suttclife efficiency) for stream flow in most cases was above 0.9, whereas the Ens for sediment was from 0.46 to 0.9 though the ENS for nutrient in some individual cases was less than 0.36. We have also studied the correlation between the precipitation and the surface runoff, sediment load, nutrient load in the TGR area, too. The results of our simulated investigation have shown that the surface runoff and sediment load were both closely related with the precipitation, except that the peak of sediment load took place earlier than that of surface runoff in April or May occasionally. The reason for the sediment situation is perhaps that it is because of the large amounts of the soil loss caused by the tillage and precipitation activities during the season. As to the nutrient load, especially, the TP, the consequence seems also relevant to the sediment load in comparison with the surface runoff. And, finally, we have also analyzed the pollution loads generated by the different landuse types in the area. When we worked out the order of the average pollution load for different landuse situations, we have found that the most serious non-point sources of pollution are the crop fileds in the TGR area. So it is urgent to improve the

  18. Bio-Economic Strategy to Combat Non-Point Pollution in China

    Institute of Scientific and Technical Information of China (English)

    WEI Yong-Ping; CHEN De-Li; B.DAVIDSON; R.E.WHITE

    2005-01-01

    While non-point pollution from agriculture has become an increasingly serious problem in China, some progress has been made in studying the causal biophysical processes. However, few studies have assessed the economic consequences of non-point pollution in China or the policy options that could be employed to combat it. In this work a sustainable strategy to control non-point pollution from crop production, which involved taxing excessive inputs of irrigation water and fertilizer, was proposed. The approach taken to assess these measures combined biophysical and economic models,having a trade-off between economic returns and an improved environment. A proven and practical spatially referenced water and nutrient management model was used to determine the quantities of excessive irrigation water and fertilizer for specific soil and land use. Also, a set of indicators were proposed for evaluating the effects of agricultural economic output and agricultural practices on the environment.

  19. 基于改进USLE模型的北运河流域非点源污染潜在敏感区分析%Potential Sensitive Areas Analysis of Non-Point Source Pollution in North Canal Basin based on Improved USLE Model

    Institute of Scientific and Technical Information of China (English)

    靳美珠; 张晓惠; 袁雪竹

    2012-01-01

    Based on the universal soil loss equation (USLE), the model of demarcation of sensitive areas of the non-point pollution in North Canal basin is developed. With the database of TM remote sensing images, digital elevation model (DEM), and the map of soil use type in research area in 2009, distribution map of sensitive areas of non-point source in North Canal basin is produced by the model. Base on the simulation, the three risk areas (high, medium and low) and safe areas are identified. Results show that improved model can be effectively used in the analysis of sensitive areas of non-point source pollution.%基于通用土壤流失方程(USLE)建立北运河流域非点源污染敏感区的划分模型,以2009年研究区域TM遥感影像、数字高程模型(DEM)、研究区土壤利用类型图等为数据基础,在GIS9.3和ERDAS9.2平台上通过对各模型因子进行栅格运算生成北运河流域非点源污染潜在敏感区分布图,在此基础上划分了高、中、低三个风险区以及安全区.鉴于我国与美国不同的自然条件,以及土壤流失与固体垃圾的扩散之间所存在的差异,在引进和应用该模型时,对方程中各因子的算法和参数做了一定的调整和改进,结果表明改进后的模型可以有效的运用于非点源污染敏感区的分析.

  20. Effects of Climate Change on Non-Point Pollution in Huaibei Region and Comprehensive Regulation Strategies%气候变化对淮北地区面源污染的影响及综合调控

    Institute of Scientific and Technical Information of China (English)

    王刚; 严登华; 尹军; 翁白莎

    2011-01-01

    分析了安徽省淮北地区面源污染的现状与压力,从污染物的产生、迁移、转化与汇聚的机理讨论气候变化对面源污染的影响机制,最后从源头控制、途径控制、末端治理、调控机制建设4个层面提出综合调控措施.%In this study, the situation and pressure of non-point pollution in Huaibei region of Anhui province were analyzed. The influence mechanism of climate change on non-point pollution was discussed from mechanism of generation, migration, conversion, and aggregation of contaminants. In the end, comprehensive coping strategies were put forward from four levels: source control, process control, end treatment and construction of regulation mechanism.

  1. Synthetic aperture controlled source electromagnetics

    NARCIS (Netherlands)

    Fan, Y.; Snieder, R.; Slob, E.; Hunziker, J.W.; Singer, J.; Sheiman, J.; Rosenquist, M.

    2010-01-01

    Controlled‐source electromagnetics (CSEM) has been used as a de‐risking tool in the hydrocarbon exploration industry. Although there have been successful applications of CSEM, this technique is still not widely used in the industry because the limited types of hydrocarbon reservoirs CSEM can detect.

  2. Advanced controls for light sources

    Science.gov (United States)

    Biedron, S. G.; Edelen, A. L.; Milton, S. V.

    2016-09-01

    We present a summary of our team's recent efforts in developing adaptive, artificial intelligence-inspired techniques specifically to address several control challenges that arise in machines/systems including those in particle accelerator systems. These techniques can readily be adapted to other systems such as lasers, beamline optics, etc… We are not at all suggesting that we create an autonomous system, but create a system with an intelligent control system, that can continually use operational data to improve itself and combines both traditional and advanced techniques. We believe that the system performance and reliability can be increased based on our findings. Another related point is that the controls sub-system of an overall system is usually not the heart of the system architecture or design process. More bluntly, often times all of the peripheral systems are considered as secondary to the main system components in the architecture design process because it is assumed that the controls system will be able to "fix" challenges found later with the sub-systems for overall system operation. We will show that this is not always the case and that it took an intelligent control application to overcome a sub-system's challenges. We will provide a recent example of such a "fix" with a standard controller and with an artificial intelligence-inspired controller. A final related point to be covered is that of system adaptation for requirements not original to a system's original design.

  3. Control system for Siam photon source

    CERN Document Server

    Apiwatwaja, R; Isoyama, G; Ishii, T; Pairsuwan, W

    2003-01-01

    A new computer control system has been developed for Siam photon source, which is the first synchrotron light source in Thailand, personal computers and PLC's have been employed which are connected together through Ethernet. Man Machine Interface Stations (MMIS) at the front end act as a graphical user interface within Windows environment. The monitoring and controlling of individual devices is handled through several pairs of digital control station and the device interface located in each part of the synchrotron complex. The installation of the control system has been completed. The commissioning test of the control system is underway and the reliability of the system is on the positive side. Details of commissioning tests as well as characteristics of this newly built control system for the Siam photon source are described in this report.

  4. Marine Controlled-Source Electromagnetic Interferometry

    NARCIS (Netherlands)

    Hunziker, J.W.

    2012-01-01

    In marine Controlled-Source Electromagnetics, a boat tows an electric source, whose signal is travelling on various paths to the receiver stations at the ocean bottom. Unfortunately, the signal does not only travel via the subsurface to the receivers, but also directly through the water and via the

  5. Simple Signal Source based Micro Controller

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Using micro controller, DAC and Multi-periods syn-thesis, we can buildup a very simple signal source with precisefrequency, amplitude and waveform. Wave parameters can beprogrammed in advance. The circuit can satisfy some special re-quirements.

  6. 2011 NATA - Emissions Sources

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes all emissions sources that were modeled in the 2011 National Air Toxics Assessment (NATA), inlcluding point, nonpoint, and mobile sources, and...

  7. Evaluating Urbanization Impacts from Non-Point Stormwater Runoff using Geospatial Analysis

    Science.gov (United States)

    Zivkovich, B. R.; Mays, D. C.

    2015-12-01

    Sediments, nutrients and other chemical impairments caused by urbanization continue to deteriorate natural ecosystem processes, resulting in the current degraded state of urban surface waters. Understanding non-point source impacts on these natural ecosystems has become a prevalent topic in sustainable urban infrastructure design as efforts to restore the urban hydrologic regime continue to drive engineers, planners, and environmentalists to develop optimal design practices for rapidly expanding built environments. To best understand how and where these impairments are received, the U.S. Environmental Protection Agency and other organizations have adopted urban runoff programs to identify contributions from non-point sources. This presentation provides a geospatial analysis method for identifying non-point source watersheds, and associated sub-basins, that contribute the highest loads of pollutants to receiving urban streams and lakes. This method, using a form of linear matrix inversion, is an area-averaged weighting method for non-point pollutants that corresponds to a geospatial land cover analysis. This two-phase analysis can be used to aid all parties in understanding how different land use types affect urban stream systems and processes. Optimal locations for water quality features (i.e., best management practices) can be evaluated in order to reduce, capture, and treat stormwater runoff as close to the source as possible. These best management practices have the ability to operate most effectively when located properly, because their ability to act as a minor treatment and prevention system is of great important for the restoration of the urban hydrologic regime.

  8. Open source software to control Bioflo bioreactors.

    Directory of Open Access Journals (Sweden)

    David A Burdge

    Full Text Available Bioreactors are designed to support highly controlled environments for growth of tissues, cell cultures or microbial cultures. A variety of bioreactors are commercially available, often including sophisticated software to enhance the functionality of the bioreactor. However, experiments that the bioreactor hardware can support, but that were not envisioned during the software design cannot be performed without developing custom software. In addition, support for third party or custom designed auxiliary hardware is often sparse or absent. This work presents flexible open source freeware for the control of bioreactors of the Bioflo product family. The functionality of the software includes setpoint control, data logging, and protocol execution. Auxiliary hardware can be easily integrated and controlled through an integrated plugin interface without altering existing software. Simple experimental protocols can be entered as a CSV scripting file, and a Python-based protocol execution model is included for more demanding conditional experimental control. The software was designed to be a more flexible and free open source alternative to the commercially available solution. The source code and various auxiliary hardware plugins are publicly available for download from https://github.com/LibourelLab/BiofloSoftware. In addition to the source code, the software was compiled and packaged as a self-installing file for 32 and 64 bit windows operating systems. The compiled software will be able to control a Bioflo system, and will not require the installation of LabVIEW.

  9. Open source software to control Bioflo bioreactors.

    Science.gov (United States)

    Burdge, David A; Libourel, Igor G L

    2014-01-01

    Bioreactors are designed to support highly controlled environments for growth of tissues, cell cultures or microbial cultures. A variety of bioreactors are commercially available, often including sophisticated software to enhance the functionality of the bioreactor. However, experiments that the bioreactor hardware can support, but that were not envisioned during the software design cannot be performed without developing custom software. In addition, support for third party or custom designed auxiliary hardware is often sparse or absent. This work presents flexible open source freeware for the control of bioreactors of the Bioflo product family. The functionality of the software includes setpoint control, data logging, and protocol execution. Auxiliary hardware can be easily integrated and controlled through an integrated plugin interface without altering existing software. Simple experimental protocols can be entered as a CSV scripting file, and a Python-based protocol execution model is included for more demanding conditional experimental control. The software was designed to be a more flexible and free open source alternative to the commercially available solution. The source code and various auxiliary hardware plugins are publicly available for download from https://github.com/LibourelLab/BiofloSoftware. In addition to the source code, the software was compiled and packaged as a self-installing file for 32 and 64 bit windows operating systems. The compiled software will be able to control a Bioflo system, and will not require the installation of LabVIEW.

  10. Effects of Grass Hedges and No-tillage Practice Oil the Removing of Typical Agricultural Non-point Source Pollutants from Runoff%免耕和草篱措施对径流中典型农业面源污染物的去除效果

    Institute of Scientific and Technical Information of China (English)

    李霞; 陶梅; 肖波; 王庆海; 陈建平

    2011-01-01

    Chemical fertilizer and herbicide are widely used in agricultural production. These chemical substances not only significantly increase crop yields but also result in serious water pollution. This study was conducted to evaluate the effects of three practices (no-tillage, grass hedges, no-tillage and grass hedges) on the loss of nitrogen, phosphorus and atrazine with runoff. The results showed that no-tillage and grass hedges significantly reduced agricultural non-point source pollution. As compared to the control, the total nitrogen, total phosphorus and atrazine loss in the plots with no-tillage were decreased by 53%, 51% and 56%, respectively; reductions by the grass hedges were 68%, 61% and 90%, respectively; the decreases due to no-tillage and grass hedges were 77%, 76% and 92%, respectively. Moreover, the regression results showed that the losses of nitrogen, phosphorus and atrazine with runoff were positively correlated to the surface runoff. From these results could be concluded that both of no-tillage and grass hedges could significantly reduce nitrogen, phosphorus and atrazine loss with runoff, and the integration of these two practices was proved to be much more effective than their individual effects.%大量施用农业化学物质在提高作物产量的同时,也导致了严重的水体污染.在北京地区不同坡度的径流小区上,通过人工模拟降雨试验,研究免耕、草篱、以及免耕与草篱复合3种措施对农田径流中氮、磷、阿特拉津3种典型农业面源污染物的去除效果.结果表明:免耕措施可减少53%的总氮、51%的总磷和56%的阿特拉津流失;草篱措施可减少68%的总氮、61%的总磷和90%的阿特拉津流失;而免耕与草篱复合措施可减少77%的总氮、76%的总磷和92%的阿特拉津流失.另外,总氯、总磷和阿特拉津流失量均与径流量呈显著的线性正相关关系.本研究证实,免耕和草篱措施均能有效防止氮、磷以及阿特拉津随农

  11. Source apportionment and spatial heterogeneity of agricultural non-point source pollution based on water environmental function zoning%基于水环境功能区划的农业面源污染源解析及其空间异质性

    Institute of Scientific and Technical Information of China (English)

    钱晓雍; 沈根祥; 郭春霞; 顾海蓉; 朱英; 王振旗

    2011-01-01

    Taking township as basic unit, the inventory analysis method and equivalent standard method were conducted to determine the discharge amount of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) from different types of agricultural non-point sources, including chemical fertilizer application, animal manure application, crop straws, animal husbandry, aquaculture and rural sewage. The impact of agricultural non-point source pollution (ANPSP) on water environment and its spatial heterogeneity were analyzed based on water environmental function zoning at the scales of county and town. The results indicated that, the absolute discharge amount of COD, TN and TP from ANPSP were 4.42× 104,1.13× 104, 0.44× 104 t/a respectively, and the discharge amount in equivalent standard were 0.16× 104, 0.93 × 104, 1.65× 104 m3/a respectively. The primary pollution source was animal husbandry, which load ratio in equivalent standard reached 66.31%, and the primary pollutant was TP, which load ratio in equivalent standard reached 60.32%. Discharge concentration of COD, TN and TP caused by ANPSP in different districts were in the range of 4.16-40.91, 1.30-8.71, 0.23-4.94 mg/L respectively, while the average water quality index ranged from 0.67 to 5.91. From the point view of town-based pollution stress, the pollution extent of the towns in South Shanghai and Chongming Island was much higher, which had greater agriculture productive value and located near the water conservation area with stricter water quality standards.%通过清单分析方法和等标污染负荷法,以乡镇为单元研究了上海市化肥施用、有机肥施用、农作物秸秆、畜禽养殖、水产养殖、农村生活污水等农业面源污染来源化学需氧量(COD)、总氮(TN)、总磷(TP)等污染物的排放量及其贡献率,并根据各区域水环境功能区划分别在区县尺度和乡镇尺度分析了农业面源污染程度及其区域分布.结果表明,上

  12. The Empirical Analysis of EKC on Agricultural Non-Point Source Pollution in Chongqing%重庆市农业面源污染源的 EKC实证分析

    Institute of Scientific and Technical Information of China (English)

    刘志欣; 邵景安; 李阳兵

    2015-01-01

    Based on the Environmental Kuznets Curve theory and the data from 2000-2012 of Chongqing , five indexes ,w hich are related to the agricultural non‐point source pollution ,are selected as variances and the Environmental Kuznets Curve model are established to analyze the relationship between agricultural non‐point source pollution and the agricultural economic growth .Meanwhile ,use the software of Eviews 7 .0 and SPSS 17 .0 to estimate the parameters .The conclusions can be drawn as follows :1) The chemical fertilizer application level ,the pesticide application level and the emission density of crop residues exhibited typical inverted‐U shaped curve relations with the per capita agricultural net income of farmers .And the chemical fertilizer application level ,pesticide application level and the emission density of crop residues have reduced with the agricultural economic grow th .2) During the study period ,the agricultural films ap‐plication level exhibited liner relations with the per capita agriculture net income of farmers .With the grow th of agricultural economy ,the environmental pressure caused by agricultural films will be further in‐creased .3) The pig droppings equivalent emission density of livestock and poultry manure with the per ca‐pita agricultural net income of farmers exhibited “N”shaped curve characteristics ,the curve exists two in‐flection points .Currently it’s on the right side of the second inflection point and it indicates that the envi‐ronmental pressure caused by livestock and poultry manure pollution will deteriorate again with the devel‐opment of agricultural economy .The government should take effective measures to strengthen the agricul‐tural non‐point source pollution control .%基于环境库兹涅茨曲线理论,根据重庆市2000-2012年的时序数据,选取5个与农业面源污染有关的指标作为污染变量,分析农业面源污染与农业经济增长的关系,并利用EVIEWS7.0

  13. A regionalized assessment of the influence of rural nonpoint source pollution on the ecological integrity of stream ecosystems and an evaluation of associated pollution control management : Proposal addendum

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is an addendum to a proposal to assess the influence of land form and land use practices in the generation of NPSP in Kansas, Nebraska, and Iowa. The addendum...

  14. AnnAGNPS – A United States Department of Agriculture Watershed Conservation Management Planning Tool for Non-Point Source Pollution Control

    Science.gov (United States)

    A watershed scale assessment of the effect of conservation practices on the environment is critical when recommending best management practices to agricultural producers. The environmental benefits of these practices have not been widely quantified at the watershed scale, which would require extens...

  15. A regionalized assessment of the influence of rural nonpoint source pollution on the ecological integrity of stream ecosystems and an evaluation of associated pollution control management

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The University of Kansas, Kansas Biological Survey (KBS) proposes a joint investigation with the University of Nebraska (Lincoln), and Iowa State University to...

  16. Controlled source electromagnetic methods in geothermal exploration

    Energy Technology Data Exchange (ETDEWEB)

    Ward, S.H.

    1983-04-01

    The objective of this manuscript is to sketch the problems inherent in application of controlled source electromagnetic methods (CSEM) to geothermal exploration. Measurements have been made in both the time and frequency domains with time domain measurements currently enjoying an advantage over frequency domain measurements for shallow applications. Application of CSEM methods is impeded by natural field, electrification, geological, cultural, and topographic noise. Lateral resolution of parameters of adjacent steeply dipping bodies and vertical resolution of parameters of adjacent beds in a flatly dipping sequence are concerns with any CSEM method. Current channeling into a localized good conductor form a surrounding, overlying, or underlying conductor poses problems for the interpreter. In selecting a transmitter-receiver configuration for CSEM in a particular application, a compromise is usually achieved between such factors as domain of data acquisition, rejection of noise, resolution, current channeling, and depth of exploration. Not surprisingly there is only marginal agreement on the optimum selection of each of these variables. However, one of the more promising techniques for application in geothermal exploration is the controlled source audiomagnetotelluric method (CSAMT).

  17. 基于“压力-响应”机制的江苏省农业面源污染源解析及其空间特征%Spatial Distribution Characteristics and Source Origin of Agricultural Non-point Source Pollution in Jiangsu Province Based on Pressure-response System

    Institute of Scientific and Technical Information of China (English)

    陆尤尤; 胡清宇; 段华平; 卞新民

    2012-01-01

    运用清单分析、等标负荷和聚类分析等方法,对江苏省农业面源污染源、影响因子、空间分布特征等进行了分析与评价.结果表明:江苏省农业面源污染化学需氧量(COD)、全氮(TN)、全磷(TP)绝对实物排放量分别为155.23×104 t/a、62.34×104 t/a、9.05×104t/a,相应的绝对等标排放量分别为7.76×104 t/a、62.34×104 t/a、45.23×104t/a.农业面源污染造成的COD、TN、TP的平均排放浓度分别为6.25 mg/L、2.53mg/L、0.36 mg/L,排放浓度地区差异显示苏北>苏中>苏南.农业面源污染综合水质指数显示,江苏省均值为2.10,达到中度污染水平.其中徐州、连云港、宿迁处于严重污染状态;淮安、盐城、泰州处于中度污染状态;南通、扬州处于轻度污染状态;南京处于警戒状态;无锡、常州、苏州、镇江处于安全状态.主要污染物依次是TN、TP,其贡献率分别为54.71%和38.86%;主要污染源依次是化肥施用、畜禽养殖、人粪尿、水产养殖,其贡献率分别为30.75%、24.94%、16.85%、15.28%;在国土面积、农业产值和农村人口几大因子中,农业产值是与污染物排放量相关性程度最高的因子.通过对”压力-响应”的表征量进行聚类分析得出江苏省农业面源污染的空间分布特征,其压力和响应基本一致.%The primary source, influence factors, and spatial distribution characteristics of agricultural non-point source pollution (NPSP) in Jiangsu Province were analyzed by inventory analysis, equivalent standard load, and cluster analysis methods. Results showed that the absolute real emissions of COD, TN and TP from NPSP were 155.23× 104t/a, 62.34×l04t/a and 9.05×l04t/a respectively. And the related standard emissions were 7.76×104 t/a, 62.34×104t/a and 45.23×104 t/a. The average concentrations of COD, TN and TP emitted from NPSP were 6.25 mg/L, 2.53 mg/L, 0.36 mg/L, respectively. The concentrations of these

  18. Non-Point Pollution from Crop Production: Global,Regional and National Issues

    Institute of Scientific and Technical Information of China (English)

    D.NORSE

    2005-01-01

    China is now the world's largest producer and user of industrial fertilizers and manures. Consequently China plays a substantial role in global N cycle dynamics and in man's disruption of the nitrogen cycle though there are still significant uncertainties about the size and importance of emission and leaching rates. A major cause of 1China's global role is the overuse of nitrogen fertilizers, which is most serious with intensive vegetable production where application rates can be up to 50% greater than crop needs, but is also a problem with wheat, rice and maize.China's overuse of nitrogen fertiliser over the past 10-20 years has resulted in non-point source (NPS) pollution from crop production becoming a major cause of water pollution, and the situation is projected to get worse. In contrast, water pollution from point sources such as intensive livestock production and urban or industrial development is being brought more under control. The consequences for air pollution are equally serious. Emissions of nitrous oxide from fertilizers and manures may be so large that China could be responsible for 25-30% of global emissions of this damaging greenhouse gas and of the global warming resulting from it.The main national and local issues relate particularly to low fertilizer use efficiency and the losses of ammonia and NOx that lead to acid precipitation, and leaching and run-off losses that result in high nitrate levels in groundwater and eutrophication of rivers and lakes. The reasons why farmers overuse nitrogen fertilizer are complex and not fully understood. They involve agro-climate differences between provinces and counties, farming systems and farm income structures. Although there is a wide range of institutional and technological improvements that can greatly reduce this overuse rapid progress in reducing NPS is unlikely.

  19. Controlled Source Electromagnetic Monitoring of Hydraulic Fracturing

    Science.gov (United States)

    Couchman, M. J.; Everett, M. E.

    2016-12-01

    Controlled Source Electromagnetics (CSEM) have been used as a direct hydrocarbon indicator since the 1960s, with a resurgence in marine conventional settings in the new millennium, with many studies revolving around detecting a thin resistive layer such as a reservoir at 1m-3km depth. The presence of the resistive layer is characterized by a jump in electric field amplitude recorded at the boundary between the layer and the host sediments. Here the lessons learned from these studies are applied to terrestrial unconventional settings. However, unlike in marine settings where resistive hydrocarbon-charged fluids comprise a conventional reservoir, on land we are interested in electrically conductive injected fluids. The work shown here is a means to develop further methods to enable more reliable terrestrial CSEM monitoring of the flow of injected fluids associated with hydraulic fracturing of unconventional reservoirs and to detect subsurface fluids based on their CSEM signature and in turn, to infer the subsurface flow of electrically conductive injected fluids. Overall this project attempts to create more efficient fracturing, by determining fluid pathways, hence making projects more cost effective by reducing the cost of extraction. The predictive model developed focuses on the mapping of fluid flow in from a horizontal pipe in a uniform halfspace using a long in-line Horizontal Electric Dipole (HED) with electric field amplitude recorded by an array of electric field sensors. The code provided has been edited to include a long-dipole source in addition to the half dipole source originally in place in order to align with current CSEM field practices. The well casing has also been included due to its large effect on CSEM response.

  20. Laser controlled atom source for optical clocks

    Science.gov (United States)

    Kock, Ole; He, Wei; Świerad, Dariusz; Smith, Lyndsie; Hughes, Joshua; Bongs, Kai; Singh, Yeshpal

    2016-11-01

    Precision timekeeping has been a driving force in innovation, from defining agricultural seasons to atomic clocks enabling satellite navigation, broadband communication and high-speed trading. We are on the verge of a revolution in atomic timekeeping, where optical clocks promise an over thousand-fold improvement in stability and accuracy. However, complex setups and sensitivity to thermal radiation pose limitations to progress. Here we report on an atom source for a strontium optical lattice clock which circumvents these limitations. We demonstrate fast (sub 100 ms), cold and controlled emission of strontium atomic vapours from bulk strontium oxide irradiated by a simple low power diode laser. Our results demonstrate that millions of strontium atoms from the vapour can be captured in a magneto-optical trap (MOT). Our method enables over an order of magnitude reduction in scale of the apparatus. Future applications range from satellite clocks testing general relativity to portable clocks for inertial navigation systems and relativistic geodesy.

  1. Anthropogenic point and non-point nitrogen inputs into Huai River Basin and their impacts on riverine ammonia-nitrogen flux

    Science.gov (United States)

    Zhang, W. S.; Swaney, D. P.; Li, X. Y.; Hong, B.; Howarth, R. W.; Ding, S. H.

    2015-02-01

    This study provides a new approach to estimate both anthropogenic non-point and point nitrogen (N) inputs to the landscape, and determines their impacts on riverine ammonia-nitrogen (AN) flux, providing a foundation for further exploration of anthropogenic effects on N pollution. Our study site is Huai River Basin of China, a watershed with one of the highest levels of N input in the world. Multi-year average (2003-2010) inputs of N to the watershed are 27 200 ± 1100 kg N km-2 yr-1. Non-point sources comprised about 98% of total N input and only 2% of inputs are directly added to the aquatic ecosystem as point sources. Fertilizer application was the largest non-point source of new N to the Huai River Basin (69% of net anthropogenic N inputs), followed by atmospheric deposition (20%), N fixation in croplands (7%), and N content of imported food and feed (2%). High N inputs showed impacts on riverine AN flux: fertilizer application, point N input and atmospheric N deposition were proved as more direct sources to riverine AN flux. Modes of N delivery and losses associated with biological denitrification in rivers, water consumption, interception by dams influenced the extent of export of riverine AN flux from N sources. Our findings highlight the importance of anthropogenic N inputs from point and non-point sources in heavily polluted watersheds, and provide some implications for AN prediction and management.

  2. Including non-point sfources in a water quality trading permit program.

    Science.gov (United States)

    Collentine, D

    2005-01-01

    There has been overwhelming interest in addressing water quality issues through the use of economic instruments. Much of this attention has focused on the cost efficiencies offered by Transferable Discharge Permit (TDP) systems. Unfortunately, the attempts to start up permit markets which are able to exploit abatement cost differences between sources have not met with the success expected. Two of the reasons for the lack of success that have been taken up in analysis of these programs have been the problem of transaction costs and in the case of non-point sources (NPS), undefined property rights. The composite market design is a proposal for a TDP system which specifically includes agricultural non-point source (NPS) dischargers and addresses both property rights and transaction cost problems. The composite market consists of three interrelated markets each serving a particular function. When the composite market is mature, the total number of permits issued represents the cap on discharges allowed in the catchment. The structure of the composite market allows this system to be phased in over time with existing institutions and limited demands on financing.

  3. A Summary of Best Management Practices for Nonpoint Source Pollution

    Science.gov (United States)

    1992-08-01

    with a. temporary seeding. b. permanent seeding. c. mulching. d. sod, trees, shrubs, vines , and ground cover. 35. Dikes and bermns or level spreaders...tree pruning . Maintenance inspe~ctionts should be used to aiXentify any routine maintenance requirements. Nonroutine maintenance practices involve the...sediments from the inlets could be done manually or hy a vacuum pump. Tree Pruning . The trees adjacent to any infiltration trench may need to be

  4. Reconnaissance survey of nonpoint source pesticides in Maryland surface waters

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — As part of the Chesapeake Bay Agreement, the "Maryland Toxics Reduction Strategy for the Chesapeake Bay and its Tributaries" committed the State to identify the most...

  5. Nonpoint Source Pollution Taxes and Excessive Tax Burden

    Energy Technology Data Exchange (ETDEWEB)

    Karp, L. [Department of Agricultural and Resource Economics, University of California, 207 Giannini Hall, Berkeley, CA 94720 (United States)

    2005-06-01

    If a regulator is unable to measure firms individual emissions, an ambient tax can be used to achieve the socially desired level of pollution. With this tax, each firm pays a unit tax on aggregate emissions. In order for the tax to be effective, firms must recognize that their decisions affect aggregate emissions. When firms behave strategically with respect to the tax-setting regulator, under plausible circumstances their tax burden is lower under an ambient tax, relative to the tax which charges firms on the basis of individual emissions. Firms may prefer the case where the regulator is unable to observe individual firm emissions, even if this asymmetric information causes the regulator to tax each firm on the basis of aggregate emissions.

  6. Literature Review: Computer Aided Assessment Techniques for Nonpoint Source Discharges

    Science.gov (United States)

    1991-04-01

    Equilibrium Metals Speciation Model ( MINTEQ ) is a highly specialized model for metals only. It produces highly precise results, but requires a high level of...dynamic model that can be used for evaluating the behavior of syn- thetic organic chemicals in lakes, rivers and estuaries. 5. MINTEQ : The...conventional pollutants in surface and ground waters," Part I and Part 2, EPA-600/685/002a,b, Washington, DC, 1985. (1987a). " MINTEQAl : An equilibrium

  7. Mosquito larval source management for controlling malaria.

    Science.gov (United States)

    Tusting, Lucy S; Thwing, Julie; Sinclair, David; Fillinger, Ulrike; Gimnig, John; Bonner, Kimberly E; Bottomley, Christian; Lindsay, Steven W

    2013-08-29

    Malaria is an important cause of illness and death in people living in many parts of the world, especially sub-Saharan Africa. Long-lasting insecticide treated bed nets (LLINs) and indoor residual spraying (IRS) reduce malaria transmission by targeting the adult mosquito vector and are key components of malaria control programmes. However, mosquito numbers may also be reduced by larval source management (LSM), which targets mosquito larvae as they mature in aquatic habitats. This is conducted by permanently or temporarily reducing the availability of larval habitats (habitat modification and habitat manipulation), or by adding substances to standing water that either kill or inhibit the development of larvae (larviciding). To evaluate the effectiveness of mosquito LSM for preventing malaria. We searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; CABS Abstracts; and LILACS up to 24 October 2012. We handsearched the Tropical Diseases Bulletin from 1900 to 2010, the archives of the World Health Organization (up to 11 February 2011), and the literature database of the Armed Forces Pest Management Board (up to 2 March 2011). We also contacted colleagues in the field for relevant articles. We included cluster randomized controlled trials (cluster-RCTs), controlled before-and-after trials with at least one year of baseline data, and randomized cross-over trials that compared LSM with no LSM for malaria control. We excluded trials that evaluated biological control of anopheline mosquitoes with larvivorous fish. At least two authors assessed each trial for eligibility. We extracted data and at least two authors independently determined the risk of bias in the included studies. We resolved all disagreements through discussion with a third author. We analyzed the data using Review Manager 5 software. We included 13 studies; four cluster-RCTs, eight controlled before

  8. Mosquito larval source management for controlling malaria

    Science.gov (United States)

    Tusting, Lucy S; Thwing, Julie; Sinclair, David; Fillinger, Ulrike; Gimnig, John; Bonner, Kimberly E; Bottomley, Christian; Lindsay, Steven W

    2015-01-01

    Background Malaria is an important cause of illness and death in people living in many parts of the world, especially sub-Saharan Africa. Long-lasting insecticide treated bed nets (LLINs) and indoor residual spraying (IRS) reduce malaria transmission by targeting the adult mosquito vector and are key components of malaria control programmes. However, mosquito numbers may also be reduced by larval source management (LSM), which targets mosquito larvae as they mature in aquatic habitats. This is conducted by permanently or temporarily reducing the availability of larval habitats (habitat modification and habitat manipulation), or by adding substances to standing water that either kill or inhibit the development of larvae (larviciding). Objectives To evaluate the effectiveness of mosquito LSM for preventing malaria. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; CABS Abstracts; and LILACS up to 24 October 2012. We handsearched the Tropical Diseases Bulletin from 1900 to 2010, the archives of the World Health Organization (up to 11 February 2011), and the literature database of the Armed Forces Pest Management Board (up to 2 March 2011). We also contacted colleagues in the field for relevant articles. Selection criteria We included cluster randomized controlled trials (cluster-RCTs), controlled before-and-after trials with at least one year of baseline data, and randomized cross-over trials that compared LSM with no LSM for malaria control. We excluded trials that evaluated biological control of anopheline mosquitoes with larvivorous fish. Data collection and analysis At least two authors assessed each trial for eligibility. We extracted data and at least two authors independently determined the risk of bias in the included studies. We resolved all disagreements through discussion with a third author. We analyzed the data using Review Manager 5 software

  9. A Control Source Structure of Single Loudspeaker and Rear Sound Interference for Inexpensive Active Noise Control

    Directory of Open Access Journals (Sweden)

    Yasuhide Kobayashi

    2010-01-01

    phase-lag is imposed by the Swinbanks' source and the rear sound interference. Thirdly, effects on control performances of control source structures are examined by control experiments with robust controllers.

  10. Imaging with power controlled source pairs

    CERN Document Server

    Bardsley, Patrick

    2015-01-01

    Scatterers in a homogeneous medium are imaged by probing the medium with two point sources of waves modulated by correlated signals and by measuring only intensities at one single receiver. For appropriately chosen source pairs, we show that full waveform array measurements can be recovered from such intensity measurements by solving a linear least squares problem. The least squares solution can be used to image with Kirchhoff migration, even if the solution is determined only up to a known one-dimensional nullspace. The same imaging strategy can be used when the medium is probed with point sources driven by correlated Gaussian processes and autocorrelations are measured at a single location. Since autocorrelations are robust to noise, this can be used for imaging when the probing wave is drowned in background noise.

  11. Model predictive control for Z-source power converter

    DEFF Research Database (Denmark)

    Mo, W.; Loh, P.C.; Blaabjerg, Frede

    2011-01-01

    This paper presents Model Predictive Control (MPC) of impedance-source (commonly known as Z-source) power converter. Output voltage control and current control for Z-source inverter are analyzed and simulated. With MPC's ability of multi- system variables regulation, load current and voltage...... of variable switching frequency as well as robustness of transient response can be obtained at the same time with a formulated Z-source network model. Operating steady state and transient state simulation of MPC are going to be presented, which shows good reference tracking ability of this control method....

  12. Relative local control and the block source algebras

    Institute of Scientific and Technical Information of China (English)

    樊恽

    1997-01-01

    The local control of pointed groups is generalized to the concept of relative local control,and it is proved that there exists a lifting for a covering of a block source algebra if the relative local control holds.As an application,a result is proved on the source algebras of blocks,whose defect groups are direct products of a normal subgroup and a subgroup that gives a relative local control.

  13. 西充河流域(西充县境内)面源污染现状与防治措施%Non-point Source Pollution and Control Measures of Xichong River Basin (Xi-chong Territory)

    Institute of Scientific and Technical Information of China (English)

    王小霞; 黎小东; 张洪波; 刘星; 吴碧琼

    2015-01-01

    Taking for example the 23 towns ,in Xichong River Basin (Xi-chong territory) ,the output coefficient method is used to e‐valuate the rural non-point source pollution comprehensively from the perspective of the various sources and different towns and put forward some corresponding control measures .The results show that the main pollution in the research area is the rural non-point source pollution :①83 .3% of the pollution load comes from chemical fertilizer pollution ,rural residents living sewage and backyard poultry ;②The pollution in Hong-xi River is more serious than Longtan River;③The most polluted village is Jin-cheng Town .Ac‐cording to the results of this evaluation ,this paper puts forward the corresponding comprehensive control of non-point source pollu‐tion in engineering and non-engineering measures and suggestions .%以西充河流域(西充县境内)的23个乡镇为例,采用输出系数法,从各个污染源和不同乡镇的角度出发,对西充县境内的农村面源污染进行了综合评价,并提出相应的防治措施。结果表明:研究区内的主要污染为农村面源污染:①83.3%的污染负荷来源于为化肥污染、农村居民生活污水和散养畜禽;②虹溪河支流与龙滩河相比,污染较严重;③污染最严重的乡镇为晋城镇。根据评估结果,本文提出了相应的面源污染综合治理的工程及非工程措施和建议。

  14. High voltage source control on FODS

    Science.gov (United States)

    Patalakha, D. I.; Kalinin, A. Yu; Kulagin, N. V.

    2017-01-01

    The implementation of the high voltage power supply control system (HVPSCS) for experimental setup FODS (FOcusing Doublearmed Spectrometer) at accelerator U-70 of the Federal State Budgetary Institution State Research Center Of Russia Institute for High Energy Physics of the National Research Centre “Kurchatov Institute” (hereinafter referred to as IHEP) or for the test bench of the detector components is considered. The required set of hardware is defined and the appropriate software to operate HVPSCS is written in C/C++ codes. The date acquisition (DAQ) system [1] makes automatic control on HVPSCS for data taking run. It allows to get the dependence of appropriate detector parameters on the high voltage supply values and choose its optimal values for FODS detectors. The test run results of HVPSCS are presented.

  15. Model predictive control for Z-source power converter

    DEFF Research Database (Denmark)

    Mo, W.; Loh, P.C.; Blaabjerg, Frede

    2011-01-01

    This paper presents Model Predictive Control (MPC) of impedance-source (commonly known as Z-source) power converter. Output voltage control and current control for Z-source inverter are analyzed and simulated. With MPC's ability of multi- system variables regulation, load current and voltage...... regulations, impedance network inductor current, capacitor voltage as well as switching frequency fixation, transient reservation and null state penalization are all regulated as subjecting to constraints of this control method. The quality of output waveform, stability of impedance-network, level constraint...... of variable switching frequency as well as robustness of transient response can be obtained at the same time with a formulated Z-source network model. Operating steady state and transient state simulation of MPC are going to be presented, which shows good reference tracking ability of this control method....

  16. ACCELERATORS Control system for the CSNS ion source test stand

    Science.gov (United States)

    Lu, Yan-Hua; Li, Gang; Ouyang, Hua-Fu

    2010-12-01

    A penning plasma surface H- ion source test stand for the CSNS has just been constructed at the IHEP. In order to achieve a safe and reliable system, nearly all devices of the ion source are designed to have the capability of both local and remote operation function. The control system consists of PLCs and EPICS real-time software tools separately serving device control and monitoring, PLC integration and OPI support. This paper summarizes the hardware and software implementation satisfying the requirements of the ion source control system.

  17. Renewable source controls for grid stability.

    Energy Technology Data Exchange (ETDEWEB)

    Byrne, Raymond Harry; Elliott, Ryan Thomas; Neely, Jason C.; Silva Monroy, Cesar Augusto; Schoenwald, David Alan; Grant, Lisa

    2012-12-01

    The goal of this study was to evaluate the small signal and transient stability of the Western Electric- ity Coordinating Council (WECC) under high penetrations of renewable energy, and to identify control technologies that would improve the system performance. The WECC is the regional entity responsible for coordinating and promoting bulk electric system reliability in the Western Interconnection. Transient stability is the ability of the power system to maintain synchronism after a large disturbance while small signal stability is the ability of the power system to maintain synchronism after a small disturbance. Tran- sient stability analysis usually focuses on the relative rotor angle between synchronous machines compared to some stability margin. For this study we employed generator speed relative to system speed as a metric for assessing transient stability. In addition, we evaluated the system transient response using the system frequency nadir, which provides an assessment of the adequacy of the primary frequency control reserves. Small signal stability analysis typically identi es the eigenvalues or modes of the system in response to a disturbance. For this study we developed mode shape maps for the di erent scenarios. Prony analysis was applied to generator speed after a 1.4 GW, 0.5 second, brake insertion at various locations. Six di erent WECC base cases were analyzed, including the 2022 light spring case which meets the renewable portfolio standards. Because of the di culty in identifying the cause and e ect relationship in large power system models with di erent scenarios, several simulations were run on a 7-bus, 5-generator system to isolate the e ects of di erent con gurations. Based on the results of the study, for a large power system like the WECC, incorporating frequency droop into wind/solar systems provides a larger bene t to system transient response than replacing the lost inertia with synthetic inertia. From a small signal stability

  18. An estimation on budget and control of phosphorus in the Changjiang River catchment.

    Science.gov (United States)

    Shen, Zhi-Liang; Li, Zheng; Miao, Hui

    2012-11-01

    Based on field investigations in the Changjiang River mouth, rain sampling from the river's upper reaches to the mouth, historical data, and relevant literatures, the budget and major control factors of total phosphorus (TP) and dissolved inorganic phosphorus (DIP) in the river catchment were estimated and discussed from the catchment scale. It will supply a base for effective controlling P concentration in the Changjiang River and its mouth. Results show that the export fluxes of TP and DIP were mainly controlled by the river runoff. The TP and DIP in the Changjiang River came mainly from agricultural nonpoint source P losses from fertilizer and soil and point sources of industrial waste and residential sewage discharges. The export fluxes of TP and DIP in the river mouth were only 27.0% and 28.3% of the imports from the river catchment, respectively, suggesting that most of P were removed in transportation. A mass of freshwater marshes in the river catchment were the main areas to remove P. Significant increasing in utilization of fertilizer P and incessant increasing in water and soil loss areas were the primary reasons of agricultural nonpoint source P losses. How to decrease the agricultural nonpoint source P loss from the catchment scale is a key controlling P concentration in the Changjiang River and its mouth. The point source industrial waste P discharge has been primarily treated in the river catchment, but the residential sewage P discharge needs further control.

  19. RCT: Module 2.08, Radiological Source Control, Course 8774

    Energy Technology Data Exchange (ETDEWEB)

    Hillmer, Kurt T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-10

    radioactive source is material used for its emitted radiation. Sources are sealed or unsealed and are classified as accountable or exempt. Radioactive sources are used for response checks, functional checks, and the calibration of instruments and monitors to traceable standards. To ensure the safety and welfare of all personnel, it is important to maintain control of radioactive sources to minimize the potential for the spread of contamination, unnecessary exposure to personnel, loss or theft, and improper disposal. This course will prepare the student with the skills necessary for RCT qualification by passing quizzes, tests, and the RCT Comprehensive Phase 1, Unit 2 Examination (TEST 27566) and will provide in-the-field skills.

  20. Control of heat source in a heat conduction problem

    Science.gov (United States)

    Lyashenko, V.; Kobilskaya, E.

    2014-11-01

    The mathematical model of thermal processes during the heat treatment of a moving axisymmetric environment, for example wire. is considered. The wire is heated by internal constantly or periodically operating heat source. It is presented in the form of initial-boundary value problem for the unsteady heat equation with internal constantly or periodically operating heat source. The purpose of the work is the definition of control parameter of temperature field of a moving area, which is heated by internal heat source. The control parameters are determined by solving a nonlocal problem for the heat equation. The problem of getting an adequate temperature distribution throughout the heating area is considered. Therefore, a problem of heat source control is solved, in particular, control by electric current. Control of the heat source allows to maintain the necessary, from a technological point of view, temperature in the heating area. In this paper, to find additional information about the source of heat. The integral condition is used in the control problem. Integral condition, which is considered in the work, determines the energy balance of the heating zone and connects the desired temperature distribution in the internal points of area with temperatures at the boundaries. Control quality in an extremum formulation of the problem is assessed using the quadratic functional. In function space, from a physical point of view, proposed functional is the absolute difference between the actual emission of energy and absorbed energy in the heating zone. The absorbed energy is calculated by solving of the boundary value problem. Methods of determining the control parameters of temperature field are proposed. The resulting problem is solved by iterative methods. At different physical conditions, numerical calculations are carried out, control parameters of the heat treatment process are obtained.

  1. Management control of support services : The case of IT sourcing

    NARCIS (Netherlands)

    Lau, La E.; Laan, van der M.; Speklé, R.F.; Kruis, A.

    2009-01-01

    This paper provides evidence on the factors that influence the design of the control arrangements that govern support services. Based on TCE, we hypothesize that control structure choices depend on asset specificity, uncertainty, and frequency. Using survey data on IT sourcing decisions from 89 firm

  2. Two Sources of Control over the Generation of Software Instructions

    CERN Document Server

    Hartley, A; Hartley, Anthony; Paris, Cecile

    1996-01-01

    This paper presents an analysis conducted on a corpus of software instructions in French in order to establish whether task structure elements (the procedural representation of the users' tasks) are alone sufficient to control the grammatical resources of a text generator. We show that the construct of genre provides a useful additional source of control enabling us to resolve undetermined cases.

  3. Virtual-Impedance-Based Control for Voltage-Source and Current-Source Converters

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Li, YunWei; Blaabjerg, Frede;

    2015-01-01

    The virtual impedance concept is increasingly used for the control of power electronic systems. Generally, the virtual impedance loop can either be embedded as an additional degree of freedom for active stabilization and disturbance rejection, or be employed as a command reference generator...... for the converters to provide ancillary services. This paper presents an overview of the virtual-impedance-based control strategies for voltage-source and current-source converters. The control output impedance shaping attained by the virtual impedances is generalized first using the impedance-based models...

  4. Assessment of control technology for stationary sources. Volume II: control technology data tables. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Minicucci, D.; Herther, M.; Babb, L.; Kuby, W.

    1980-02-01

    This report, the Control Technology Data Tables, is the second volume of the three-volume final report for the contract. It presents in tabular format, qualitative descriptions of control options for the various sources and quantitative information on control technology cost, efficiency, reliability, energy consumption, other environmental impacts and application status. Also included is a code list which classifies the stationary sources examined by industry, process, and emission source.

  5. Controlling the Emission of Electromagnetic Sources by Coordinate transformation

    CERN Document Server

    Luo, Yu; Ran, Lixin; Chen, Hongsheng; Kong, Jin Au

    2007-01-01

    The coordinate transformation on the space that contains electromagnetic sources is studied. We find that, not only the permittivity and permeability tensors of the media, but also the sources inside the media will take another form in order to behave equivalently as the original case. It is demonstrated that, a source of arbitrary shape and position in the free space can be replaced by an appropriately designed metamaterial coating with current distributed on the inner surface and would not be detected by outer observers, because the emission of the source can be controlled at will in this way. As examples, we show how to design conformal antennas by covering the sources with transformation media. The method proposed in this letter provides a completely new approach to develop novel active EM devices.

  6. Spraying food sources with pyrethroid to control peridomestic triatomines

    Directory of Open Access Journals (Sweden)

    Maria Hismenia Maximo Garcia

    2013-09-01

    Full Text Available Introduction We attempted to supplement traditional insecticide spraying by treating peridomiciliar food sources with a powder formulation. Methods Two groups of houses were treated with deltamethrin suspension concentrate (SC, one of which had its primary peridomestic food sources treated with deltamethrin 2P. Results Triatoma brasiliensis was the most commonly captured triatomine. Birds, dogs and rodents were the major food sources identified by the precipitin reaction; 554 domestic animals received powder treatment. A sharp reduction in infestation rates was observed in the two groups up to 360 days after spraying. Conclusion The combination SC + 2P did not improve the control of triatomines.

  7. Design and development of the CSNS ion source control system

    CERN Document Server

    Yan-Hua, Lu; Hua-Fu, Ouyang

    2013-01-01

    After the CSNS ion source test stand has been stably working for years, an online control system for CSNS ion source aiming to be more stable and reliable is now under development. F3RP61-2L, a new PLC CPU module under Linux system, is introduced to the system as an IOC, to function together with the I/O modules of FA-M3 PLC on the PLC-bus. The adoption of the new IOC not only simplifies the architecture of the control system, but also improves the data transmission speed. In this paper, the design and development of the supervisory and control system for CSNS ion source are described.

  8. Design and development of the CSNS ion source control system

    Institute of Scientific and Technical Information of China (English)

    LU Yan-Hua; LI Gang; OUYANG Hua-Fu

    2013-01-01

    Now that the CSNS ion source test stand has been stably working for years,an online control system for the CSNS ion source which aims to be more stable and reliable is now under development.F3RP61-2L,a new PLC CPU module running an embedded Linux system,is introduced to the system as an IOC,to function together with the I/O modules of FA-M3 PLC on the PLC-bus.The adoption of the new IOC not only simplifies the architecture of the control system,but also improves the data transmission speed.In this paper,the design and development of the supervisory and control system for the CSNS ion source are described.

  9. Generating polarization controllable FELs at Dalian coherent light source

    CERN Document Server

    Zhang, T; Wang, D; Zhao, Z T; Zhang, W Q; Wu, G R; Dai, D X; Yang, X M

    2013-01-01

    The property of the FEL polarization is of great importance to the user community. FEL pulses with ultra-high intensity and flexible polarization control ability will absolutely open up new scientific realms. In this paper, several polarization control approaches are presented to investigate the great potential on Dalian coherent light source, which is a government-approved novel FEL user facility with the capability of wavelength continuously tunable in the EUV regime of 50-150 nm. The numerical simulations show that both circularly polarized FELs with highly modulating frequency and 100 microjoule level pulse energy could be generated at Dalian coherent light source.

  10. Generalized space vector control for current source inverters and rectifiers

    Directory of Open Access Journals (Sweden)

    Roseline J. Anitha

    2016-06-01

    Full Text Available Current source inverters (CSI is one of the widely used converter topology in medium voltage drive applications due to its simplicity, motor friendly waveforms and reliable short circuit protection. The current source inverters are usually fed by controlled current source rectifiers (CSR with a large inductor to provide a constant supply current. A generalized control applicable for both CSI and CSR and their extension namely current source multilevel inverters (CSMLI are dealt in this paper. As space vector pulse width modulation (SVPWM features the advantages of flexible control, faster dynamic response, better DC utilization and easy digital implementation it is considered for this work. This paper generalizes SVPWM that could be applied for CSI, CSR and CSMLI. The intense computation involved in framing a generalized space vector control are discussed in detail. The algorithm includes determination of band, region, subregions and vectors. The algorithm is validated by simulation using MATLAB /SIMULINK for CSR 5, 7, 13 level CSMLI and for CSR fed CSI.

  11. The Sources of Air Pollution and Their Control.

    Science.gov (United States)

    National Air Pollution Control Administration (DHEW), Arlington, VA.

    The problems of air pollution and its control are discussed. Major consideration is given the sources of pollution - motor vehicles, industry, power plants, space heating, and refuse disposal. Annual emission levels of five principle pollutants - carbon monoxide, sulfur dioxide, nitrogen oxides, hydrocarbons, and particulate matter - are listed…

  12. Independent Source Coding for Control over Noiseless Channels

    DEFF Research Database (Denmark)

    da Silva, Eduardo; Derpich, Milan; Østergaard, Jan

    2010-01-01

    By focusing on a class of source coding schemes built around entropy coded dithered quantizers, we develop a framework to deal with average data-rate constraints in a tractable manner that combines ideas from both information and control theories. We focus on a situation where a noisy linear system...

  13. [Non-point loads of soluble cadmium by in situ field experiment with different landuses, in central Hunan province mining area].

    Science.gov (United States)

    Liu, Xiao-li; Zeng, Zhao-xia; Chen, Zhe; Tie, Bai-qing; Chen, Qiu-wen; Ye, Chang-cheng

    2013-09-01

    Non-point source loads of heavy metals from contaminated soil has increasingly become the major cause of heavy metal concentrations of rivers and lakes surpassed the limitation value, while only few studies had focused on quantitative monitoring of soil heavy metal transportation to water, in situ field conditions. As reported, agricultural farmland heavy metal contamination was the major contamination problem, especially for cadmium (Cd) pollution in middle and downstream of Xiangjiang River. This study selected the typical Cd polluted agricultural watershed for a case study, three typical landuse types of rice, dry farmland and unused grassland with three replicate quadrates were carried out for natural rainfall runoff hydrology processes monitoring, from 2011-2012. Results showed that, precipitation pH value increased from spring to summer, soluble Cd concentration of spring runoff was significantly higher than that of summer rainfall runoff, which presented an obviously seasonal heterogeneity and had a negative correlation with rainfall pH value, and rainfall pH value can obviously impact soil soluble Cd transportation into surface runoff charge. In the same rainfall event, soluble Cd concentration and non-point load of rice were significantly lower than those of dry land and unused grassland, while no obviously seasonal trend was found for non-point load of Cd from three typical landuse types because of the rainfall depth variance, which needs more researches and concerns in the future. These results can provide valuable data and scientific supports for watershed scale's heavy metal non-point source load quantitative estimation and water environment management and water quality diagnosis and early warning.

  14. Stability analysis of direct current control in current source rectifier

    DEFF Research Database (Denmark)

    Lu, Dapeng; Wang, Xiongfei; Blaabjerg, Frede

    2017-01-01

    Current source rectifier with high switching frequency has a great potential for improving the power efficiency and power density in ac-dc power conversion. This paper analyzes the stability of direct current control based on the time delay effect. Small signal model including dynamic behaviors...... of dc link is developed to identify the control plants of grid ac current control and dc current control. Analysis on the poles and zeros under dq frame is carried out. Base on this model, it turns out that the phase lag caused by the time delay can stabilized the grid ac current control while reduces...... the stable region for dc current control. Simulation and experimental results are presented to validate the theoretical analysis....

  15. On an Analog Controlled Precision Heat Power Source

    Science.gov (United States)

    Seilmayer, M.; Katepally, V. K.

    2017-07-01

    The analog controlled precision heat power source is the main part of a sensor development to estimate real time properties of the primary coolant in a 300 kW process cooling system. The measurement of physical properties like thermal conductivity or thermal diffusion requires a precise and accurate heater. The constant heat flux is then applied to the liquid under test to acquire its different properties. Here, commonly established control methods of heating with constant current or constant voltage may fail because the heating resistor changes its resistance with temperature. The idea is to utilize a power monitor circuit like the LT2940, which contains an analog multiplier with a control loop around it. The initial design and its assumed uncertainties will be discussed. The first version of the power controller shows an outstanding performance in terms of precision in a steady state. Compared to conventional switching mode power sources the approach with an analog controlled heater avoids EMI issues as well. The main goal of the present design is a precise source of heat power with less than 0.5% of error.

  16. The Advanced Photon Source Injector Test Stand Control System

    CERN Document Server

    MacLean, J F

    2001-01-01

    The Advanced Photon Source (APS) primary and backup injectors consist of two thermionic-cathode rf guns. These guns are being upgraded to provide improved performance, to improve ease of maintenance, and to reduce downtime required for repair or replacement of a failed injector. As part of the process, an injector test stand is being prepared. This stand is effectively independent of the APS linac and will allow for complete characterization and validation of an injector prior to its installation into the APS linac. A modular control system for the test stand has been developed using standard APS control solutions with EPICS to deliver a flexible and comprehensive control system. The modularity of the system will allow both the future expansion of test stand functionality and the evaluation of new control techniques and solutions.

  17. A source-controlled data center network model.

    Science.gov (United States)

    Yu, Yang; Liang, Mangui; Wang, Zhe

    2017-01-01

    The construction of data center network by applying SDN technology has become a hot research topic. The SDN architecture has innovatively separated the control plane from the data plane which makes the network more software-oriented and agile. Moreover, it provides virtual multi-tenancy, effective scheduling resources and centralized control strategies to meet the demand for cloud computing data center. However, the explosion of network information is facing severe challenges for SDN controller. The flow storage and lookup mechanisms based on TCAM device have led to the restriction of scalability, high cost and energy consumption. In view of this, a source-controlled data center network (SCDCN) model is proposed herein. The SCDCN model applies a new type of source routing address named the vector address (VA) as the packet-switching label. The VA completely defines the communication path and the data forwarding process can be finished solely relying on VA. There are four advantages in the SCDCN architecture. 1) The model adopts hierarchical multi-controllers and abstracts large-scale data center network into some small network domains that has solved the restriction for the processing ability of single controller and reduced the computational complexity. 2) Vector switches (VS) developed in the core network no longer apply TCAM for table storage and lookup that has significantly cut down the cost and complexity for switches. Meanwhile, the problem of scalability can be solved effectively. 3) The SCDCN model simplifies the establishment process for new flows and there is no need to download flow tables to VS. The amount of control signaling consumed when establishing new flows can be significantly decreased. 4) We design the VS on the NetFPGA platform. The statistical results show that the hardware resource consumption in a VS is about 27% of that in an OFS.

  18. A source-controlled data center network model

    Science.gov (United States)

    Yu, Yang; Liang, Mangui; Wang, Zhe

    2017-01-01

    The construction of data center network by applying SDN technology has become a hot research topic. The SDN architecture has innovatively separated the control plane from the data plane which makes the network more software-oriented and agile. Moreover, it provides virtual multi-tenancy, effective scheduling resources and centralized control strategies to meet the demand for cloud computing data center. However, the explosion of network information is facing severe challenges for SDN controller. The flow storage and lookup mechanisms based on TCAM device have led to the restriction of scalability, high cost and energy consumption. In view of this, a source-controlled data center network (SCDCN) model is proposed herein. The SCDCN model applies a new type of source routing address named the vector address (VA) as the packet-switching label. The VA completely defines the communication path and the data forwarding process can be finished solely relying on VA. There are four advantages in the SCDCN architecture. 1) The model adopts hierarchical multi-controllers and abstracts large-scale data center network into some small network domains that has solved the restriction for the processing ability of single controller and reduced the computational complexity. 2) Vector switches (VS) developed in the core network no longer apply TCAM for table storage and lookup that has significantly cut down the cost and complexity for switches. Meanwhile, the problem of scalability can be solved effectively. 3) The SCDCN model simplifies the establishment process for new flows and there is no need to download flow tables to VS. The amount of control signaling consumed when establishing new flows can be significantly decreased. 4) We design the VS on the NetFPGA platform. The statistical results show that the hardware resource consumption in a VS is about 27% of that in an OFS. PMID:28328925

  19. Z Source Inverter for Photovoltaic System with Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    Vijayabalan R

    2012-10-01

    Full Text Available In this paper, the photovoltaic system is used to extract the maximum power from sun to get the dc voltage. The output dc voltage is boost up into maximum voltage level by using the SEPIC converter. This converter voltage is fed to Z source inverter to get the AC voltage. The Z source inverter system can boost the given input voltage by controlling the boost factor, to obtain the maximum voltage. PWM technique which is used as to given the gating pulse to the inverter switches. Modified system is very promising for residential solar energy system. In stand-alone systems the solar energy yield is matched to the energy demand. Wherever it was not possible to install an electricity supply from the mains utility grid, or desirable, stand-alone photovoltaic systems could be installed. This proposed system is cost-effective for photovoltaic stand-alone applications. This paper describes the design of a rule based Fuzzy Logic Controller (FLC for Z Source inverter. The obtained AC Voltage contains harmonics of both odd and even harmonics of lower and higher order. Higher order harmonics are eliminated with the help of Filters. Here the impedance network act as a filter to reduce the lower order harmonics obtained in the system. So with the help of FFT analysis this value is obtained to be 15.82%.

  20. A Study on the Mechanism of Emission Trading between Industrial Point Pollution and Agriculture Non-Point Pollution%工业点源-农业面源排污权交易的机制创新研究

    Institute of Scientific and Technical Information of China (English)

    王奇; 王会; 陈海丹; 詹贤达

    2011-01-01

    Agriculture non-point pollution has been one of the most important sources of the water pollution in China.Compared with industrial point pollution, the emission reduction cost of agriculture non-point pollution is lower, which make the emission trade feasible. First, the characteristics of agriculture non-point pollution were recognized as that agriculture non-point pollution had many sources, uncertainty in occurring, difficulty to supervise. Then, two emission trade mechanisms had been built, one of which was that farmers changed production behavior uniformly and the other was that industrial point pollution built public pollution eliminating infrastructures. Finally, some key problem in the emission trading between industrial point pollution and agriculture non-point pollution were discussed.%当前,农业面源污染已经成为我国水环境污染的主要来源.相比较于大型工业点源,农业面源污染减排成本较低的状况为二者进行排污权交易提供了有利条件.在分析面源污染具有涉及个体多、发生不确定性强、减排结果监测困难等特征的基础上,提出了工业点源与农业面源排污权交易的两种机制:基于污染产生的"农户统一行动交易机制"和基于污染治理的"农业公共治理设施建设交易机制".最后,针对工业点源-农业面源排污权交易中存在的一些问题进行了初步探讨.

  1. A New Model for the Genesis of Natural Gases--Multi-source Overlap, Multi-stage Continuity, Type Controlled by Main Source and Nomenclature by Main Stage (Ⅰ)--Multi-source Overlap and Type Controlled by Main Source

    Institute of Scientific and Technical Information of China (English)

    徐永昌; 沈平

    1994-01-01

    Based on the geochemical studies of natural gases in the past ten years in China, the authors have proposed a new model for their genesis--multi-source overlap, multi-stage continuity, main source-controlling type and nomenclature by the main stage.Multi-source refers to a diversity of material sources involved in the formation of natural gases, including abiogenic and biogenic material sources. In regard to biogenic sources, either oil-generating or coal-generating organic matter would produce gaseous hydrocarbon reservoirs of commercial importance. Generally, natural gases originating from these sources can overlap to form gas reservoirs. Under specific circumstances mantle-source abiogenic gases could overlap biogenic gases to form gas reservoirs. In nature, natural gases predominated by gaseous hydrocarbons may be formed from a single end-member source. However, multi-source overlap is more typical of the genesis of natural gases.

  2. Assessment of point and non-point pollution associated with the power generation sector in South Africa.

    Science.gov (United States)

    van Zyl, H D; Heath, R G

    2007-01-01

    Access to water and water availability remains a key factor in ensuring the sustainability of development in Southern Africa. The need for guidelines to improve management of this valuable resource, and to regulate pollutant discharge, is therefore of national interest. A new and growing threat to our natural water resources is non-point source (NPS) pollution. The important distinction between point pollution and NPS pollution is that the latter is difficult to identify and the entry point of contamination to resources is diffuse and not limited to a single location. NPS pollution associated with power generation includes, but is not limited to, atmospheric deposition resulting from emissions (air and water), leachate from coal storage piles and runoff from impervious areas which are covered with dust fallout from coal and ash handling operations. Emissions of primary concern are sulfur, nitrogen and mercury.

  3. Amine control for DUV lithography: identifying hidden sources

    Science.gov (United States)

    Kishkovich, Oleg P.; Larson, Carl E.

    2000-06-01

    The impact of airborne basic molecular contamination (MB) on the performance of chemically amplified (CA) resist systems has been a long standing problem. Low ppb levels of MB may be sufficient for robust 0.25 micrometer lithography with today's advanced CA resist systems combined with adequate chemical air filtration. However, with minimum CD targets heading below 150 nm, the introduction of new resist chemistries for Next Generation Lithography, and the trend towards thinner resists, the impact of MB at low and sub-ppb levels again becomes a critical manufacturing issue. Maximizing process control at aggressive feature sizes requires that the level of MB be maintained below a certain limit, which depends on such parameters as the sensitivity of the CA resist, the type of production tools, product mix, and process characteristics. Three approaches have been identified to reduce the susceptibility of CA resists to MB: effective chemical air filtration, modifications to resist chemistry/processing and cleanroom protocols involving MB monitoring and removal of MB sources from the fab. The final MB concentration depends on the effectiveness of filtration resources and on the total pollution originating from different sources in and out of the cleanroom. There are many well-documented sources of MB. Among these are: ambient air; polluted exhaust from other manufacturing areas re-entering the cleanroom through make-up air handlers; manufacturing process chemicals containing volatile molecular bases; certain cleanroom construction materials, such as paint and ceiling tiles; and volatile, humidifier system boiler additives (corrosion inhibitors), such as morpholine, cyclohexylamine, and dimethylaminoethanol. However, there is also an indeterminate number of other 'hidden' pollution sources, which are neither obvious nor well-documented. None of these sources are new, but they had little impact on earlier semiconductor manufacturing processes because the contamination

  4. Marine Controlled Source EM Methods: Equipment, Methodology, and Results

    Science.gov (United States)

    Constable, S.; Behrens, J.; Key, K.

    2005-12-01

    The marine CSEM method has become an important tool for academia and the petroleum industry. Commercially viable seafloor receivers were developed for marine MT exploration over the last decade, but progress in CSEM transmitter design is still at an early stage. We have developed 200~A and 500~A transmitters (Scripps Undersea Electromagnetic Source Instrument, or SUESI-200/500) which operate within the 30~kVA power limitations of academic tow cables. This is done by careful control of antenna impedance (resistance and inductance) and power efficiency. Electrode impedance is largely a function of length, rather than surface area or diameter. The antenna can be made neutrally buoyant by balancing the weight of an aluminum conductor with a thick plastic jacket. Telemetry for control, navigation, and monitoring is overlaid on high voltage power transmission down coaxial tow cables, as an alternative to fiber optic telemetry, allowing use with winches and cables of opportunity. The CSEM noise floor determines the source--receiver ranges, and thus the investigation depths, that can be achieved, and depends on frequency, dipole moment, receiver noise, magnetotelluric interference, and stack time. For typical values, this is 10-15~VA-1m-2. We present examples of data from a sub-salt hydrocarbon prospect in the Gulf of Mexico, and an academic project over the magma chambers of the East Pacific Rise.

  5. Tin LPP plasma control in the argon cusp source

    Science.gov (United States)

    McGeoch, Malcolm W.

    2016-03-01

    The argon cusp plasma has been introduced [1,2] for 500W class tin LPP exhaust control in view of its high power handling, predicted low tin back-scatter from a beam dump, and avoidance of hydrogen usage. The physics of tin ion control by a plasma is first discussed. Experimentally, cusp stability and exhaust disc geometry have previously been proved at full scale [2], the equivalent of 300W-500W usable EUV. Here we verify operation of the plasma barrier that maintains a high argon density next to the collector, for its protection, and a low density in the long path toward the intermediate focus, for efficiency. A pressure differential of 2Pa has been demonstrated in initial work. Other aspects of tin LPP plasma control by the cusp have now been demonstrated using tin ions from a low Hz 130mJ CO2 laser pulse onto a solid tin surface at the cusp center. Plasma is rejected at the design to match a specified exhaust power is discussed. In view of this work, argon cusp exhaust control appears to be very promising for 500W class tin LPP sources.

  6. 生物滞留技术控制城市面源污染的作用与机理%EFFECT AND MECHANISM OF BIORETENTION TECHNOLOGY FOR URBAN NON-POINT SOURCE POLLUTIONS CONTROL

    Institute of Scientific and Technical Information of China (English)

    李平; 王晟

    2014-01-01

    生物滞留设施可以有效削减降雨径流,并通过过滤、吸附和生物降解去除雨水径流水中的氮、磷、多环芳烃、油脂、重金属、细菌和病毒等,其主要设计参数是:暴雨重现期、面积、稳定下渗率、下凹深度和淹水时间.建议改造城市附属绿地为生物滞留,加快该技术在我国的推广应用.

  7. IRIS Controlled Source Seismic Experiments: Continental Structure, Instrumentation, and Education

    Science.gov (United States)

    Mooney, W. D.; Keller, G. R.

    2004-12-01

    The controlled-source seismology program of IRIS/PASSCAL has made major contributions to the study of continental structure and evolution. It has also undergone major developments in seismic instrumentation. The first PASSCAL experiments (1984/85) targeted the Basin and Range Province and the Ouachita orogenic belt. The Basin and Range study provided remarkably clear images of this thin, highly-extended crust, while the Ouachita experiment tested competing hypotheses for the deep structure of this Paleozoic orogen. However, both of these projects were limited by a lack of seismic instruments. The situation improved in the late 1980's with the benefit of a mixed array of 600 seismic recorders from the USGS, Stanford, and the Geological Survey of Canada. The resolution achieved with these instruments was revolutionary. Results include the imaging of such remarkable features as crustal-scale duplexes in the Brooks Range compressional orogen of northern Alaska, and of crustal "core complexes" in the extended crust of southwest Arizona. The 3-channel PASSCAL Jr. instrument was developed, leading to experiments in which ˜1000 instruments were deployed, including three-component recording. This complex mix of instruments served the community well for several years, but required large, complex instrument centers and lots of technical support. With input from PASSCAL and the international community, a newly designed, compact instrument (the Texan) was finalized in the spring of 1998, and the first 200 instruments was delivered to the Univ. of Texas-El Paso in late 1998. The present instrument pool of Texans exceeds 1,400 and these have been used on such projects as the high-resolution imaging of the Los Angeles and San Fernando basins (LARSE I and II experiments), where active thrust faults have been imaged. Controlled-source seismic experiments are now very numerous. During calendar year 2004 alone, portable Texan instruments have traveled from Venezuela to Denmark

  8. Plasma shape control by pulsed solenoid on laser ion source

    Science.gov (United States)

    Sekine, M.; Ikeda, S.; Romanelli, M.; Kumaki, M.; Fuwa, Y.; Kanesue, T.; Hayashizaki, N.; Lambiase, R.; Okamura, M.

    2015-09-01

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS.

  9. Plasma shape control by pulsed solenoid on laser ion source

    Energy Technology Data Exchange (ETDEWEB)

    Sekine, M. [Tokyo Institute of Technology, Meguro-ku, Tokyo 2-12-1 (Japan); RIKEN, Wako, Saitama 351-0198 (Japan); Ikeda, S. [Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502 (Japan); RIKEN, Wako, Saitama 351-0198 (Japan); Romanelli, M. [Cornell University, Ithaca, NY 14850 (United States); Kumaki, M. [RIKEN, Wako, Saitama 351-0198 (Japan); Waseda University, Shinjuku, Tokyo 169-0072 (Japan); Fuwa, Y. [RIKEN, Wako, Saitama 351-0198 (Japan); Kyoto University, Uji, Kyoto 611-0011 (Japan); Kanesue, T. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Hayashizaki, N. [Tokyo Institute of Technology, Meguro-ku, Tokyo 2-12-1 (Japan); Lambiase, R. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Okamura, M. [RIKEN, Wako, Saitama 351-0198 (Japan); Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2015-09-21

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS.

  10. PADF electromagnetic source localization using extremum seeking control

    Science.gov (United States)

    Al Issa, Huthaifa A.; Ordóñez, Raúl

    2014-10-01

    Wireless Sensor Networks (WSNs) are a significant technology attracting considerable research interest. Recent advances in wireless communications and electronics have enabled the development of low-cost, low-power and multi-functional sensors that are small in size and communicate over short distances. Most WSN applications require knowing or measuring locations of thousands of sensors accurately. For example, sensing data without knowing the sensor location is often meaningless. Locations of sensor nodes are fundamental to providing location stamps, locating and tracking objects, forming clusters, and facilitating routing. This research focused on the modeling and implementation of distributed, mobile radar sensor networks. In particular, we worked on the problem of Position-Adaptive Direction Finding (PADF), to determine the location of a non- collaborative transmitter, possibly hidden within a structure, by using a team of cooperative intelligent sensor networks. Position-Adaptive radar concepts have been formulated and investigated at the Air Force Research Laboratory (AFRL) within the past few years. In this paper, we present the simulation performance analysis on the application aspect. We apply Extremum Seeking Control (ESC) schemes by using the swarm seeking problem, where the goal is to design a control law for each individual sensor that can minimize the error metric by adapting the sensor positions in real-time, thereby minimizing the unknown estimation error. As a result we achieved source seeking and collision avoidance of the entire group of the sensor positions.

  11. Reliability Estimations of Control Systems Effected by Several Interference Sources

    Institute of Scientific and Technical Information of China (English)

    DengBei-xing; JiangMing-hu; LiXing

    2003-01-01

    In order to establish the sufficient and necessary condition that arbitrarily reliable systems can not be constructed with function elements under interference sources, it is very important to expand set of interference sources with the above property. In this paper, the models of two types of interference sources are raised respectively: interference source possessing real input vectors and constant reliable interferen cesource. We study the reliability of the systems effected by the interference sources, and the lower bound of the reliability is presented. The results show that it is impossible that arbitrarily reliable systems can not be constructed with the elements effected by above interference sources.

  12. Thermal Management Controller for Heat Source Temperature Control and Thermal Management

    Institute of Scientific and Technical Information of China (English)

    HUANGFU Yi; WU Jing-yi; WANG Ru-zhu; LI Sheng

    2009-01-01

    In many heat recovery processes, temperature control of heat source is often required to ensure safety and high efficiency of the heat source equipment. In addition, the management of recovered heat is important for the proper use of waste heat. To this aim, the concept of thermal management controller (TMC), which can vary heat transfer rate via the volume variation of non-condensable gas, was presented. Theoretical model and experimental prototype were established. Investigation shows that the prototype is effective in temperature control. With water as the working fluid, the vapor temperature variation is only 1.3 ℃ when the heating power varies from 2.5 to 10.0 kW. In variable working conditions, this TMC can automatically adjust thermal allocation to the heat consumer.

  13. 10 CFR 36.31 - Control of source movement.

    Science.gov (United States)

    2010-01-01

    ... audible signal to indicate that the sources are leaving the shielded position. Only one key may be in use... indicator that indicates when the sources are in the fully shielded position, when they are in transit, and...

  14. Application of Potential Non-Point Pollution Index For An Urban Watershed: Istanbul, Kucukcekmece Lagoon

    Science.gov (United States)

    Musaoglu, N.; Dikerler, T.; Seker, D. Z.; Ustun, B.

    2011-12-01

    Istanbul is a major city with more than 15 million population and limited water resources. Besides, its urbanized area has been rapidly expanding for more than 30 years. Küçükçekmece Lagoon, as a potential RAMSAR site with its rich natural diversity and housing asset for birds, has been suffering from urbanization and industrial stress. With Sazlidere Dam constructed on the Lagoon's most important creek which supplies fresh water, Küçükçekmece Basin has almost 600 km2 wide area. Due to dam operation which cuts fresh water input down, water quality of the Küçükçekmece Lagoon has been deteriorating, as well as other antropogenic impacts. Potential non-point pollution index (or PNPI) is based on land use, soil and topographic data and aims to highlight the potentially polluting areas in a watershed. Denoting those areas, PNPI puts an assessment of the pressure exerted on the water bodies by different land uses. This index calculates different layers in order to represent run-off, land cover effect, and the distance of each polluting source (or pixels) in the study area. By the multiplication of those layers under GIS, a new data layer is produced showing the polluting potential of each pixel on the study area. For by Küçükçekmece Basin, Landsat ETM satellite images have been taken and its land use produced by unsupervised classification. Using this updated data, land use - land cover indicator has been calculated for the basin. Topography is another fact that is needed to produce both run-off indicator and distance indicator and it is generated by elevation data with 5m resolution. By integrating these indicator layers, PNPI analysis layer has been produced for Küçükçekmece Lagoon watershed.

  15. Polluted dust derived from long-range transport as a major end member of urban aerosols and its implication of non-point pollution in northern China.

    Science.gov (United States)

    Yan, Y; Sun, Y B; Weiss, D; Liang, L J; Chen, H Y

    2015-02-15

    The contribution of polluted dust transported from local and distal sources remains poorly constrained due to their similar geophysical and geochemical properties. We sampled aerosols in three cities in northern China (Xi'an, Beijing, Xifeng) during the spring of 2009 to determine dust flux, magnetic susceptibility and elemental concentrations. Combining dust fluxes with wind speed and regional visibility records enabled to differentiate between dust transported from long range and derived from local sources, while the combination of magnetic susceptibility and enrichment factors (EF) of heavy metals (Pb, Zn) allowed to distinguish natural aerosols from polluted ones. Our results indicate that polluted dust from long-range transport became a major end member of urban dust aerosols. Human settlements as its potential sources were confirmed by a pollutant enriched regional dust event originating from populated areas to the south as inferred by back trajectory modeling, implying their non-point source nature of dust pollution.

  16. Reliability Estimations of Control Systems Effected by Several Interference Sources

    Institute of Scientific and Technical Information of China (English)

    Deng Bei-xing; Jiang Ming-hu; Li Xing

    2003-01-01

    In order to estab lish the sufficient and necessary condition that arbitrarily reliable systems can not be construc-ted with function elements under interference sources, it is very important to expand set of interference sources with the above property. In this paper, the models of two types of in-terference sources are raised respectively: interference source possessing real input vectors and constant reliable interference source. We study the reliability of the systems effected by the interference sources, and the lower bound of the reliability is presented. The results show that it is impossible that arbi-trarily reliable systems can not be constructed with the ele-ments effected by above interference sources.

  17. Thermodynamic inspection of concrete using a controlled heat source

    Science.gov (United States)

    Milne, James M.

    1990-10-01

    Concrete is not quite such a non-destructable material as many are led to believe. It can deteriorate with time due to changes in the chemistry, the effect of moisture penetration and the corrosion of reinforcing steel bars. Much of this damage occurs relatively close to the surface, sometimes revealed by discolourations or the presence of cracks and sometimes as spallation when the corrosion products of steel cause delamination of the near surface concrete. These effects may occur in good quality concrete but their severity and rapidity of onset may be enhanced by fabrication defects when aggregates may not be to specification or the packing conditions cause porosity. It may thus be months or even years afterwards that these defects come to light. As a consequence a new industry has been formed to inspect concrete structures which may include X-ray equipment, linac accelerators, gamma isotope sources, ultrasonics, radar and of course thermography. Each of these nethods will have their own particular attractive features and merits. But most of these activities tend to be used more as a "fire fighting" service than as one ensuring regular maintenance of critical structures or even as quality control of structures during building. Quite often it seems that Non-destructive Testing is turned into a litigation service for dissatisfied customers and thermography is no stranger to this topic. It is heartening to see that the ASTM organisation in the USA and British Standards are encouraging and developing suitable standards for the inspection of concrete by thermographic techniques.

  18. Sole-Source Lighting for Controlled-Environment Agriculture

    Science.gov (United States)

    Mitchell.Cary; Stutte, Gary W.

    2015-01-01

    Since plants on Earth evolved under broad-spectrum solar radiation, anytime they are grown exclusively under electric lighting that does not contain all wavelengths in similar proportion to those in sunlight, plant appearance and size could be uniquely different. Nevertheless, plants have been grown for decades under fluorescent (FL) (1) + incandescent (IN) (2) lamps as a sole source of lighting (SSL), and researchers have become comfortable that, in certain proportions of FL + IN for a given species, plants can appear "normal" relative to their growth outdoors. The problem with using such traditional SSLs for commercial production typically is short lamp lifespans and not obtaining enough photosynthetically active radiation (PAR, 400-700 nm) when desired. These limitations led to supplementation of FL + IN lamp outputs with longer-lived, high-intensity discharge (HID) lamps in growth chambers (3). As researchers became comfortable that mixes of orange-biased high-pressure sodium (HPS) and blue-biased metal halide (MH) HIDs together also could give normal plant growth at higher intensities, growth chambers and phytotrons subsequently were equipped mainly with HID lamps, with their intense thermal output filtered out by ventilated light caps or thermal-controlled water barriers. For the most part, IN and HID lamps have found a home in commercial protected horticulture, usually for night-break photoperiod lighting (IN) or for seasonal supplemental lighting (mostly HPS) in greenhouses. However, lack of economically viable options for SSL have held back aspects of year-round indoor agriculture from taking off commercially.

  19. Source and Control of Nitrogen for X70 Pipeline Steel

    Institute of Scientific and Technical Information of China (English)

    Min WANG; Yan-ping BAO

    2016-01-01

    The effects of some key factors on nitrogen absorption during the smelting process of X70 pipeline steel were studied,and the source of nitrogen pick-up was analyzed to find the bottleneck for nitrogen control.A series of measures were put forward to decrease the nitrogen pick-up.The results indicated that an exponential relationship existed between the nitrogen absorption index and the free oxygen in molten steel.Nitrogen absorption index could decrease below 0·3 when free oxygen in molten steel was above 100×10-6 after tapping.For low sulfur killed steel, the nitrogen absorption ratio and sulfur content satisfied a linear relationship with a slope of -0·007.Low free-oxy-gen and sulfur were beneficial to the deep desulfurization during vacuum treatment.The contradiction of high desul-furization ratio and low nitrogen pick-up during LF process could be resolved by skimming oxidizing slag after tap-ping and making new high basicity top slag.After optimization,the average content of nitrogen in final product de-creased from 46×10-6 to 35×10-6 .

  20. Can non-point pollutions emissions from agriculture be regulated efficiently using input-output taxes?

    DEFF Research Database (Denmark)

    Hansen, Line Block; Hansen, Lars Gårn

    2012-01-01

    In many parts of Europe and North America, phosphorus loss from cultivated fields is threatening natural ecosystems. Though there are similarities to other non-point agricultural emissions like nitrogen that have been studied extensively, phosphorus is often characterized by the presence of large...

  1. Two 24-hour Studies of Water Quality in the Ala Wai Canal during March and July, 1994 for the Mamala Bay Study, Pollutant Source Identification Project MB-3 (NODC Accession 0001188)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Pollutant Source Identification Project (MB-3) sought to provide a summary and analysis of pollutant loads to Mamala Bay from both point and nonpoint sources....

  2. Overview of marine controlled-source electromagnetic interferometry by multidimensional deconvolution

    NARCIS (Netherlands)

    Hunziker, J.W.; Slob, E.C.; Wapenaar, C.P.A.

    2014-01-01

    Interferometry by multidimensional deconvolution for marine Controlled-Source Electromagnetics can suppress the direct field and the airwave in order to increase the detectability of the reservoir. For monitoring, interferometry by multidimensional deconvolution can increase the source repeatability

  3. Preliminary Seafloor Controlled Source EM Results From APPLE

    Science.gov (United States)

    Behrens, J. P.; MacGregor, L.; Constable, S.; Everett, M.

    2001-12-01

    Certain events in the life cycle of oceanic lithosphere are dominantly two-dimensional. These include formation of crust at axial spreading centers and deformation at the lithosphere - asthenosphere boundary. These processes may result in an electrically anisotropic oceanic lithosphere by creating conductive pathways in preferred orientations. Controlled Source Electromagnetic (CSEM) soundings and Magnetotelluric (MT) soundings were made during the Anisotropy and Physics of the Pacific Lithosphere Experiment (APPLE), carried out in February/March 2001 approximately 600 km west of San Diego, California. Twenty seafloor electromagnetic field sensors were deployed: 4 long-wire CSEM recorders with 200 m electrode offsets, 6 high-frequency MT/CSEM recorders with two orthogonal 10 m offset electrodes and two orthogonal induction coil magnetometers, and 10 low-frequency MT recorders with a three-component fluxgate magnetometer and two orthogonal 10 m electric dipoles, 5 of which also recorded CSEM data. Every instrument was recovered, with data, during this primary cruise and a follow-up recovery cruise for the long-period instruments in August 2001. The deep-towed EM transmitter (DASI) was a 100 m horizontal electric dipole, which was towed in a 30 km radius circle around a central core of recorders. A radial tow was also performed. DASI transmitted a 4 Hz square wave throughout the CSEM phase of the experiment. Initial processing of the CSEM data reveals evidence of crustal anisotropy. In particular, transmitted electromagnetic energy is attenuated more strongly when propagating from west to east than from north to south. The difference in attenuation is about a factor of two, at a range of 30 km and a frequency of 4Hz. This confirms earlier results from the PEGASUS experiment, which proposed that oceanic lower crust and upper mantle with east-west trending lineaments of increased conductivity will exhibit greater attenuation of electric fields in the east

  4. ERIC-PCR Fingerprinting of Fecal Escherichia Coli and Microbial Source Tracking in Non-point Pollution of the Shellfish Culture Area of East China Sea%大肠埃希氏菌ERIC-PCR指纹图谱构建及贝类污染微生物源示踪

    Institute of Scientific and Technical Information of China (English)

    何力; 傅玲琳; 冯立芳; 励建荣

    2012-01-01

    Objective: to establish a host-orign fecal E. Coli DNA fingerprint library by rep-PCR method using ERIC primers from livestock and poultry farms in the shellfish culture area of East China Sea. Moreover, the efficacy of microbial source tracking (MST) based on ERIC-PCR for differentiating host sources of E. Coli from shellfish and their growing waters is also evaluated. Methods: fecal samples of poultry and livestock were obtained as cloacal swabs from different farm sites in Xiangshan Bay. E. Coli isolates were purified from the fecal samples by selective cultivation and API 20E tests. The genomic DNA of E. Coli isolates was extracted by bacterial genomic DNA purification kit and fingerprinted by ERIC-PCR. InfoQuestFPTM software was used to analyze the similarities, rate of correct classification(RCC) and the stability of library. Finally, host sources of E. Coli obtained from shellfish and shellfish growing waters were predicted using MST method by Multi-Dimensional Scaling (MDS). Results: cluster analysis of ERIC-PCR DNA fingerprints of 216 E. Coli isolates revealed 37 clusters. Jack-knife analysis revealed high rate of correct classification(RCC) with 91.7%, 76.9%, 100% and 94.4% of swine, chicken, duck and goose E. Coli isolates classified into the correct host source, respectively. In addition, based on the above host-origin library by discriminant analysis, 12 unknown source strains from shellfish and growing waters were successfully discriminanted with RCC value of 78.8%. Conclusion: this work suggests that ERIC-PCR fingerprinting can be a promising genotypic tool applied in the shellfish growing water management on East Chi na Sea for source identification of fecal pollution.%目的:采用rep-PCR的ERIC引物(ERIC-PCR)构建象山港周边粪污染指示因子大肠埃希氏菌(E.coli)的DNA指纹图谱库,并根据所建DNA指纹图谱库对贝类产品污染进行微生物源示踪(Microbial Source Tracking,MST).方法:在选定的贝类养殖区域周

  5. FNAL Proton Source High Intensity Operations and Beam Loss Control

    CERN Document Server

    Garcia, F G

    2014-01-01

    The 40-year-old Fermilab Proton Source machines, constituted by the Pre-Injector, Linac and the synchrotron Booster, have been the workhorse of the Fermi National Accelerator Laboratory (Fermilab). During this time, the High Energy Physics Program has demanded an increase in proton throughput, especially during the past decade with the beginning of the neutrino program at Fermilab. In order to achieve a successful program, major upgrades and changes were made in Booster. Once again, the Proton Source has been charged to double their beam throughput, while maintain the present residual activation levels, to meet the laboratory Intensity Frontier program goals until new machines are built and operational to replace the Proton Source machines. This paper discusses the present performance of Booster and the plans involved in reaching even higher intensities.

  6. Respiratory source control using a surgical mask: An in vitro study.

    Science.gov (United States)

    Patel, Rajeev B; Skaria, Shaji D; Mansour, Mohamed M; Smaldone, Gerald C

    2016-07-01

    Cough etiquette and respiratory hygiene are forms of source control encouraged to prevent the spread of respiratory infection. The use of surgical masks as a means of source control has not been quantified in terms of reducing exposure to others. We designed an in vitro model using various facepieces to assess their contribution to exposure reduction when worn at the infectious source (Source) relative to facepieces worn for primary (Receiver) protection, and the factors that contribute to each. In a chamber with various airflows, radiolabeled aerosols were exhaled via a ventilated soft-face manikin head using tidal breathing and cough (Source). Another manikin, containing a filter, quantified recipient exposure (Receiver). The natural fit surgical mask, fitted (SecureFit) surgical mask and an N95-class filtering facepiece respirator (commonly known as an "N95 respirator") with and without a Vaseline-seal were tested. With cough, source control (mask or respirator on Source) was statistically superior to mask or unsealed respirator protection on the Receiver (Receiver protection) in all environments. To equal source control during coughing, the N95 respirator must be Vaseline-sealed. During tidal breathing, source control was comparable or superior to mask or respirator protection on the Receiver. Source control via surgical masks may be an important adjunct defense against the spread of respiratory infections. The fit of the mask or respirator, in combination with the airflow patterns in a given setting, are significant contributors to source control efficacy. Future clinical trials should include a surgical mask source control arm to assess the contribution of source control in overall protection against airborne infection.

  7. Review of multilevel voltage source inverter topologies and control schemes

    Energy Technology Data Exchange (ETDEWEB)

    Colak, Ilhami [Department of Electrical Education, Faculty of Technical Education, Gazi University, Besevler, Ankara 06500 (Turkey); Kabalci, Ersan, E-mail: kabalci@nevsehir.edu.t [Department of Technical Programs, Vocational Collage of Haci Bektas, Nevsehir University, Hacibektas, Nevsehir 50800 (Turkey); Bayindir, Ramazan [Department of Electrical Education, Faculty of Technical Education, Gazi University, Besevler, Ankara 06500 (Turkey)

    2011-02-15

    In this study, the most common multilevel inverter topologies and control schemes have been reviewed. Multilevel inverter topologies (MLIs) are increasingly being used in medium and high power applications due to their many advantages such as low power dissipation on power switches, low harmonic contents and low electromagnetic interference (EMI) outputs. The selected switching technique to control the inverter will also have an effective role on harmonic elimination while generating the ideal output voltage. Intensive studies have been performed on carrier-based, sinusoidal, space vector and sigma delta PWM methods in open loop control of inverters. The selection of topology and control techniques may vary according to power demands of inverter. This paper and review results constitute a useful basis for matching of inverter topology and the best control scheme according to various application areas.

  8. Control and Driving Methods for LED Based Intelligent Light Sources

    DEFF Research Database (Denmark)

    Beczkowski, Szymon

    High power light-emitting diodes allow the creation of luminaires capable of generating saturated colour light at very high efficacies. Contrary to traditional light sources like incandescent and high-intensity discharge lamps, where colour is generated using filters, LEDs use additive light mixing......, where the intensity of each primary colour diode has to be adjusted to the needed intensity to generate specified colour. The function of LED driver is to supply the diode with power needed to achieve the desired intensity. Typically, the drivers operate as a current source and the intensity...... current. The model can also be used to create highly accurate luminaire model. Finally, a dual interleaved buck converter has been proposed for driving high power light-emitting diodes. Interleaving two converters lowers the output ripple current thus lowering the requirement on the output capacitor...

  9. Electron dynamics in RF sources with a laser controlled emission

    CERN Document Server

    Khodak, I V; Metrochenko, V V

    2001-01-01

    Photoemission radiofrequency (RF) electron sources are sources of electron beams with extremely high brightness. Beam bunching processes in such devices are well studied in case when laser pulse duration is much lower of rf oscillation period.At the same time photoemission RF guns have some merits when operating in 'long-pulse' mode. In this case the laser pulse duration is much higher of rf oscillation period but much lower of rise time of oscillations in a gun cavity. Beam parameters at the gun output are compared for photoemission and thermoemission cathode applications. The paper presents results of a beam dynamics simulation in such guns with different resonance structures. Questions connected with defining of the current pulse peak value that can be obtained in such guns are discussed.

  10. Effects of the airwave in time-domain marine controlled-source electromagnetics

    NARCIS (Netherlands)

    Hunziker, J.W.; Slob, E.C.; Mulder, W.

    2011-01-01

    In marine time-domain controlled-source electromagnetics (CSEM), there are two different acquisition methods: with horizontal sources for fast and simple data acquisition or with vertical sources for minimizing the effects of the airwave. Illustrations of the electric field as a function of space an

  11. Effects and Control of the Correlation Properties of Light Sources

    Science.gov (United States)

    1990-05-01

    frequency of interest. The mutual coherence function is related by a linear transform to the cross- spectral density function which describes the...Another important note here is that although there exists a simple relationship between the mutual coherence function and the cross- spectral density function , the...homogeneous, planar, secondary source can be characterized by a cross- spectral density function given by16 W(r,r 2 ;o) = G(r1 - r2 ;o) , (1.2.1) where

  12. BEAMLINE-CONTROLLED STEERING OF SOURCE-POINT ANGLE AT THE ADVANCED PHOTON SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Emery, L.; Fystro, G.; Shang, H.; Smith, M.

    2017-06-25

    An EPICS-based steering software system has been implemented for beamline personnel to directly steer the angle of the synchrotron radiation sources at the Advanced Photon Source. A script running on a workstation monitors "start steering" beamline EPICS records, and effects a steering given by the value of the "angle request" EPICS record. The new system makes the steering process much faster than before, although the older steering protocols can still be used. The robustness features of the original steering remain. Feedback messages are provided to the beamlines and the accelerator operators. Underpinning this new steering protocol is the recent refinement of the global orbit feedback process whereby feedforward of dipole corrector set points and orbit set points are used to create a local steering bump in a rapid and seamless way.

  13. Can non-point pollutions emissions from agriculture be regulated efficiently using input-output taxes?

    DEFF Research Database (Denmark)

    Hansen, Line Block; Gårn Hansen, Lars

    2014-01-01

    In many parts of Europe and North America, phosphorus loss from cultivated fields is threatening natural ecosystems. Though there are similarities to other non-point agricultural emissions like nitrogen that have been studied extensively, phosphorus is often characterized by the presence of large...... systems. Depending on the proportions of different types of farms in the agricultural sector, we find that an input-output tax system can be the core element of a close to efficient regulatory policy....

  14. The Source of Enhanced Cognitive Control in Bilinguals

    Science.gov (United States)

    Emmorey, Karen; Luk, Gigi; Pyers, Jennie E.; Bialystok, Ellen

    2009-01-01

    Bilinguals often outperform monolinguals on nonverbal tasks that require resolving conflict from competing alternatives. The regular need to select a target language is argued to enhance executive control. We investigated whether this enhancement stems from a general effect of bilingualism (the representation of two languages) or from a modality constraint that forces language selection. Bimodal bilinguals can, but do not always, sign and speak at the same time. Their two languages involve distinct motor and perceptual systems, leading to weaker demands on language control. We compared the performance of 15 monolinguals, 15 bimodal bilinguals, and 15 unimodal bilinguals on a set of flanker tasks. There were no group differences in accuracy, but unimodal bilinguals were faster than the other groups; bimodal bilinguals did not differ from monolinguals. These results trace the bilingual advantage in cognitive control to the unimodal bilingual’s experience controlling two languages in the same modality. PMID:19121123

  15. A case study on non-point source pollution and environmental carrying capacity of animal raising industry in subtropical watershed%亚热带流域氮磷排放与养殖业环境承载力实例研究

    Institute of Scientific and Technical Information of China (English)

    孟岑; 李裕元; 许晓光; 高茹; 王毅; 张满意; 吴金水

    2013-01-01

    畜禽养殖业粪便排放已经成为我国农村地区主要的农业面源污染源之一,也是制约养殖业良性发展的主要瓶颈.本文以湖南省长沙县典型亚热带流域为研究单元,基于流域水环境定位观测、耕地氮(N)磷(P)消纳能力以及养殖业调查和土壤分析资料,初步分析了亚热带丘陵区的面源污染现状及畜禽养殖业的环境承载力.结果表明,研究区金井河流域134.4 km2范围内N、P年负荷分别为N 2.72 t·km-2和P0.11t·km-2,其中养殖粪便对水体总氮(TN)、总磷(TP)负荷的贡献率分别约为42.2%和62.0%.区内平均畜禽养殖密度为3.46 AU·hm-2(相当于流域内年出栏生猪24.39万头),显著高于现有化肥用量条件下流域的实际承载力1.13 AU·hm-2(相当于流域内年出栏生猪6.35万头),因此养殖密度过高是导致研究区水体NP负荷较高的主要原因.区内N、P盈余量分别为N 35.8 kg·hm-2、P 18.61 kg·hm-2.研究区基本不施用化肥条件下畜禽养殖业的最大环境承载力为7.26 AU·hm-2,在有机肥占合理施肥量30%条件下,当地畜禽养殖业的环境承载力为2.74AU·hm-2(相当于流域内年出栏生猪19.50万头).降低养殖密度、调整养殖业空间布局以及提高养殖废弃物的资源化利用率是防治当前面源污染的有效途径.%The discharge of faeces from animal production is a major source of nitrogen ( N) and phosphorus (P) pollutants in the subtropical region of China. To quantify the N and F load from animal production to hydro-systems in the region, surveys on pig density and N,P inputs to farmlands, soil N and P contents, and annual observations of the N and P flows in the streams and the terminal river were carried out in a hilly watershed (134.4 km2 ) in Changsha County, Hunan Province. It was showed that the total NP loads from the watershed to the terminal river was 2.72 t and 0. 11 t·km-2·a-1, respectively ; within which 42. 2% of the N and 62. 0% of

  16. Multicapillary cathode controlled by a ferroelectric plasma source

    Science.gov (United States)

    Gleizer, J. Z.; Hadas, Y.; Krasik, Ya. E.

    2008-06-01

    We present results of high-current microsecond and sub-microsecond duration electron beam generation in a ~200 kV diode with a multicapillary dielectric cathode (MCDC) assisted by a ferroelectric plasma source (FPS). Electron beam current densities are achieved up to 40 A/cm2. It was shown that the operation of the MCDC is determined by the parameters of the plasma flow generated by the FPS. Also, it was found that the high resistivity of the plasma produced inside the capillaries allows effective de-coupling of individual capillary plasma discharges which results in uniform electron beam generation.

  17. Analysis and Optimal Condition of the Rear-Sound-Aided Control Source in Active Noise Control

    Directory of Open Access Journals (Sweden)

    Karel Kreuter

    2011-01-01

    Full Text Available An active noise control scenario of simple ducts is considered. The previously suggested technique of using an single loudspeaker and its rear sound to cancel the upstream sound is further examined and compared to the bidirectional solution in order to give theoretical proof of its advantage. Firstly, a model with a new approach for taking damping effects into account is derived based on the electrical transmission line theory. By comparison with the old model, the new approach is validated, and occurring differences are discussed. Moreover, a numerical application with the consideration of damping is implemented for confirmation. The influence of the rear sound strength on the feedback-path system is investigated, and the optimal condition is determined. Finally, it is proven that the proposed source has an advantage of an extended phase lag and a time delay in the feedback-path system by both frequency-response analysis and numerical calculation of the time response.

  18. Fast pulsed operation of a small non-radioactive electron source with continuous emission current control.

    Science.gov (United States)

    Cochems, P; Kirk, A T; Bunert, E; Runge, M; Goncalves, P; Zimmermann, S

    2015-06-01

    Non-radioactive electron sources are of great interest in any application requiring the emission of electrons at atmospheric pressure, as they offer better control over emission parameters than radioactive electron sources and are not subject to legal restrictions. Recently, we published a simple electron source consisting only of a vacuum housing, a filament, and a single control grid. In this paper, we present improved control electronics that utilize this control grid in order to focus and defocus the electron beam, thus pulsing the electron emission at atmospheric pressure. This allows short emission pulses and excellent stability of the emitted electron current due to continuous control, both during pulsed and continuous operations. As an application example, this electron source is coupled to an ion mobility spectrometer. Here, the pulsed electron source allows experiments on gas phase ion chemistry (e.g., ion generation and recombination kinetics) and can even remove the need for a traditional ion shutter.

  19. How phosphorus limitation can control climatic gas sources and sinks

    Science.gov (United States)

    Gypens, Nathalie; Borges, Alberto V.; Ghyoot, Caroline

    2017-04-01

    Since the 1950's, anthropogenic activities severely increased river nutrient loads in European coastal areas. Subsequent implementation of nutrient reduction policies have considerably reduced phosphorus (P) loads from mid-1980's, while nitrogen (N) loads were maintained, inducing a P limitation of phytoplankton growth in many eutrophied coastal areas such as the Southern Bight of the North Sea (SBNS). When dissolved inorganic phosphorous (DIP) is limiting, most phytoplankton organisms are able to indirectly acquire P from dissolved organic P (DOP). We investigate the impact of DOP use on the importance of phytoplankton production and atmospheric fluxes of CO2 and dimethylsulfide (DMS) in the SBNS from 1951 to 2007 using an extended version of the R-MIRO-BIOGAS model. This model includes a description of the ability of phytoplankton organisms to use DOP as a source of P. Results show that primary production can increase up to 70% due to DOP uptake in limiting DIP conditions. Consequently, simulated DMS emissions double while CO2 emissions to the atmosphere decrease, relative to the reference simulation without DOP uptake. At the end of the simulated period (late 2000's), the net direction of air-sea CO2 annual flux, changed from a source to a sink for atmospheric CO2 in response to use of DOP and increase of primary production.

  20. Research on Passivity Based Controller of Three Phase Voltage Source PWM Rectifier

    Directory of Open Access Journals (Sweden)

    Yin Hongren

    2012-09-01

    Full Text Available Euler-Lagrange (EL model of voltage source PWM rectifier is set up based on its model in synchronous dq coordinates. Passivity based controller is designed on the basis of passivity and EL model of voltage source PWM rectifier. Three switching function are educed by passivity based controller. A switching function is only realized in engineering consequently. Voltage source PWM rectifier using passivity based controller has many advantages, such as simpler structure, low total harmonic distortion, and good disturbance rejection performance. Passivity based control law is proved feasible by simulink simulation.  

  1. Descriptive Social Norms as Underappreciated Sources of Social Control

    Science.gov (United States)

    Cialdini, Robert B.

    2007-01-01

    Bockenholt and van der Heijden's results regarding compliance with insurance regulations--that the enforcement activities of a regulatory agency were relatively unpredictive of compliance--are consistent with findings from other domains (e.g., tax adherence), where personal factors and informal social controls have been shown to play a more…

  2. Outbreaks: Sources of Epidemiological Knowledge in Communicable Disease Control

    NARCIS (Netherlands)

    P.L.J.M. Mertens (Paulus Leonardus Johannes Marie)

    2008-01-01

    textabstractPublic health has been defined as the science and art of disease prevention, prolonging life, and promoting health and well-being through organized community effort for the sanitation of the environment, the control of communicable infections, the organization of medical and nursing serv

  3. Outbreaks: Sources of Epidemiological Knowledge in Communicable Disease Control

    NARCIS (Netherlands)

    P.L.J.M. Mertens (Paulus Leonardus Johannes Marie)

    2008-01-01

    textabstractPublic health has been defined as the science and art of disease prevention, prolonging life, and promoting health and well-being through organized community effort for the sanitation of the environment, the control of communicable infections, the organization of medical and nursing

  4. Equivalent Circuit for Cavity Discharges Including Controlled Current Source and Controlled Switch

    Institute of Scientific and Technical Information of China (English)

    CHEN Weigen; CHEN Xi; XIE Bo; LIU Jun

    2013-01-01

    Numerous equivalent circuits for cavity discharges have been developed,yet most of these models cannot provide simulated signals that precisely reveal the variability of the discharge's characteristic parameters,such as repetition rate,magnitude and phase of discharges,which makes them not suitable for intensive studies of discharge process.Therefore,using Simulink code,we theoretically analyzed and studied the classical equivalent circuits of cavity discharges,as well as the influence of circuit components on simulation results,and then proposed a novel equivalent circuit,the key parameters of which were determined according to the physical behavior of cavity discharges.In the novel equivalent circuit,the repetition rate can be changed by discharge resistance,inception and residual voltages;meanwhile the phase of discharge can be controlled by adjusting the parameters of shunt resistance.Furthermore,a controlled current source as a function of space charge is introduced in the equivalent circuit.Compared with the former ones,the simulated signals obtained by this novel model are better approximation of real signals.This work could be referred by latter studies of the characteristics and the mechanisms of cavity discharge in oil-paper insulation.

  5. Assessment of control technology for stationary sources. Volume I: technical discussion. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Minicucci, D.; Herther, M.; Babb, L.; Kuby, W.

    1980-02-01

    The purpose of this project was to develop a reference document for use by the Air Resources Board, local air pollution control districts, and the U.S. Environmental Protection Agency that describes technological options available for the control of emissions from stationary sources located in California. Control technologies were examined for 10 industry groups and six air pollutants. Volume I, Technical Discussion, includes an overall introduction to the project, descriptions of its major elements, background information for each industry group addressed, and the project bibliography. In Volume II, Control Technology Data Tables, qualitative descriptions of control options for the various sources and quantitative information on control technology cost, efficiency, reliability, energy consumption, other environmental impacts, and application status are presented in tabular format. Also included is a code list that classifies the stationary sources examined by industry, process and emission source.

  6. Straight to the Source: Detecting Aggregate Objects in Astronomical Images with Proper Error Control.

    Science.gov (United States)

    Friedenberg, David A; Genovese, Christopher R

    2013-07-01

    The next generation of telescopes, coming on-line in the next decade, will acquire terabytes of image data each night. Collectively, these large images will contain billions of interesting objects, which astronomers call sources. One critical task for astronomers is to construct from the image data a detailed source catalog that gives the sky coordinates and other properties of all detected sources. The source catalog is the primary data product produced by most telescopes and serves as an important input for studies that build and test new astrophysical theories. To construct an accurate catalog, the sources must first be detected in the image. A variety of effective source detection algorithms exist in the astronomical literature, but few if any provide rigorous statistical control of error rates. A variety of multiple testing procedures exist in the statistical literature that can provide rigorous error control over pixelwise errors, but these do not provide control over errors at the level of sources, which is what astronomers need. In this paper, we propose a technique that is effective at source detection while providing rigorous control on source-wise error rates. We demonstrate our approach with data from the Chandra X-ray Observatory Satellite. Our method is competitive with existing astronomical methods, even finding two new sources that were missed by previous studies, while providing stronger performance guarantees and without requiring costly follow up studies that are commonly required with current techniques.

  7. Iron and manganese contamination: sources, adverse effects and control methods.

    Science.gov (United States)

    Satyanarayana, Y V V; Saraf, Renu

    2007-10-01

    This article discusses the problem of iron and manganese contamination, the adverse effects and available control methods. The presence of iron and manganese in water causes serious commercial and health problems. Various treatment methods are available to treat water contaminated with these elements. However, catalytic media is an excellent choice particularly increasing given the preference for non-chemical water treatment. INDION ISR and BIRM are the most popularly used synthetically manufactured catalytic media.

  8. Operating Standby Redundant Controller to Improve Voltage Source Inverter Reliability

    Science.gov (United States)

    2007-12-01

    was built with two FPGAs programmed using XILINX System Generator and ISE foundation with a discrete algorithm representing the controller...Xilinx’s System Generator after parsing % H:\\Docs\\work_files\\faculty forms\\lab development\\buck_converter\\black_box_buck.vhd 121...this_block.setTopLevelLanguage(’VHDL’); this_block.setEntityName(’code’); % System Generator has to assume that your entity has a

  9. Evaluation of nonpoint-source contamination, Wisconsin: Selected data for 1992 water year

    Science.gov (United States)

    Graczyk, D.J.; Walker, J.F.; Greb, S.R.; Corsi, Steven R.; Owens, D.W.

    1993-01-01

    This report presents the annual results of the U.S. Geological Survey's (USGS) watershed-management evaluation monitoring program in Wisconsin. The overall objective of each individual project in the program is to determine if the water chemistry in the receiving stream has changed as a result of the implementation of land-management practices in the watershed. This is accomplished through monitoring of water chemistry and ancillary variables before best-management practices (BMP's) are installed ('pre-BMP'), during installation ('transitional'), and after ('post-BMP') watershed- management plans have been completely implemented. Fecal-coliform (FC) counts ranged between 10 and 310,00/100 mL. A large range of values occurred within duplicate and triplicate samples as well as over time. The median percentage difference between duplicate and triplicate samples was 17 percent although 4 out of the total 60 duplicate and triplicate samples had differences greater than 100 percent. A decrease in FC counts generally occurred over the duration of the 4-day analyses. Linear regression models of the log-concentration values (dependent variable) with respect to time (independent variable) were calculated for all samples. Negative slopes were found for 14 of the 15 samples. Slopes varied from +0.5 to -38.4 percent gain/loss/day, with a median slope of -8.5 percent/day. A t-test was applied to the data to examine whether or not significant differences in FC counts exist with respect to holding times. Because the T-test only compares two treatments, the test was conducted 3 times (0 versus 24-hr holding time, 0 versus 48-hr holding time, and 0 versus 72-hr holding time). Setting the level of significance at p less than 0.05 and assuming equal variances, 27 percent (all from Bower and Otter Creeks) of the samples demonstrated a significant difference in colony count over the first 24 hr, 40 percent over 48 hr, and 47 percent over 72 hr. All samples that exhibited a significant change in colony count were because of a decrease in colony count of the sample.

  10. MARKET INCENTIVES AND NONPOINT SOURCES: AN APPLICATION OF TRADABLE CREDITS TO URBAN STORMWATER MANAGEMENT

    Science.gov (United States)

    Excess stormwater runoff can cause serious pollution, habitat degradation and flooding in cities where growth in impervious surface area (such as pavement, buildings, etc.) has created a situation where stormwater runoff routinely exceeds the normal capacity of natural and constr...

  11. SWAT: Agricultural water and nonpoint source pollution management at a watershed scale

    Science.gov (United States)

    Global change and demographic changes increasingly cause water, food, and health problems in many areas of the world. In addition, the growth in bioenergy production leads to land-use change and associated environmental impacts. The lack of integration in resource assessments and policy-making leads...

  12. MARKET INCENTIVES AND NONPOINT SOURCES: AN APPLICATION OF TRADABLE CREDITS TO URBAN STORMWATER MANAGEMENT

    Science.gov (United States)

    Excess stormwater runoff can cause serious pollution, habitat degradation and flooding in cities where growth in impervious surface area (such as pavement, buildings, etc.) has created a situation where stormwater runoff routinely exceeds the normal capacity of natural and constr...

  13. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  14. Optimization Tool For Allocation Of Watershed Management Practices For Sediment And Nutrient Control

    Science.gov (United States)

    Implementation of conservation programs are perceived as being crucial for restoring and protecting waters and watersheds from nonpoint source pollution. Success of these programs depends to a great extent on planning tools that can assist the watershed management process. Herein...

  15. Tracing and control of raw materials sourcing for vaccine manufacturers.

    Science.gov (United States)

    Faretra Peysson, Laurence

    2010-05-01

    The control of the raw materials used to manufacture vaccines is mandatory; therefore, a very clear process must be in place to guarantee that raw materials are traced. Those who make products or supplies used in vaccine manufacture (suppliers of culture media, diagnostic tests, etc.) must apply quality systems proving that they adhere to certain standards. ISO certification, Good Manufacturing Practices for production sites and the registration of culture media with a 'Certificate of Suitability' from the European Directorate for the Quality of Medicines and Healthcare are reliable quality systems pertaining to vaccine production. Suppliers must assure that each lot of raw materials used in a product that will be used in vaccine manufacture adheres to the level of safety and traceability required. Incoming materials must be controlled in a single 'Enterprise Resource Planning' system which is used to document important information, such as the assignment of lot number, expiration date, etc. Ingredients for culture media in particular must conform to certain specifications. The specifications that need to be checked vary according to the ingredient, based on the level of risk. The way a raw material is produced is also important, and any aspect relative to cross-contamination, such as the sanitary measures used in producing and storing the raw material must be checked as well. In addition, suppliers can reduce the risk of viral contamination of raw materials by avoiding purchases in countries where a relevant outbreak is currently declared. 2010 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

  16. Current understanding in source control management in septic shock patients: a review

    Science.gov (United States)

    Encina, Belen; Ramirez-Estrada, Sergio

    2016-01-01

    Sepsis and septic shock is one of the leading causes of death worldwide. Antibiotics, fluid resuscitation support of vital organ function and source control are the cornerstones for the treatment of these patients. Source control measures include all those actions taken in the process of care to control the foci of infection and to restore optimal function of the site of infection. Source control represents the multidisciplinary team required in order to optimize critical care for septic shock patients. In the last decade an increase interest on fluids, vasopressors, antibiotics, and organ support techniques in all aspects whether time, dose and type of any of those have been described. However information of source control measures involving minimal invasion and new techniques, time of action and outcome without it, is scarce. In this review the authors resumes new information, recommendations and future directions on this matter when facing the more common types of infections. PMID:27713888

  17. Predictive ion source control using artificial neural network for RFT-30 cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Young Bae, E-mail: ybkong@kaeri.re.kr; Hur, Min Goo; Lee, Eun Je; Park, Jeong Hoon; Park, Yong Dae; Yang, Seung Dae

    2016-01-11

    An RFT-30 cyclotron is a 30 MeV proton accelerator for radioisotope production and fundamental research. The ion source of the RFT-30 cyclotron creates plasma from hydrogen gas and transports an ion beam into the center region of the cyclotron. Ion source control is used to search source parameters for best quality of the ion beam. Ion source control in a real system is a difficult and time consuming task, and the operator should search the source parameters by manipulating the cyclotron directly. In this paper, we propose an artificial neural network based predictive control approach for the RFT-30 ion source. The proposed approach constructs the ion source model by using an artificial neural network and finds the optimized parameters with the simulated annealing algorithm. To analyze the performance of the proposed approach, we evaluated the simulations with the experimental data of the ion source. The performance results show that the proposed approach can provide an efficient way to analyze and control the ion source of the RFT-30 cyclotron.

  18. Eutrophication assessment and management methodology of multiple pollution sources of a landscape lake in North China.

    Science.gov (United States)

    Chen, Yanxi; Niu, Zhiguang; Zhang, Hongwei

    2013-06-01

    Landscape lakes in the city suffer high eutrophication risk because of their special characters and functions in the water circulation system. Using a landscape lake HMLA located in Tianjin City, North China, with a mixture of point source (PS) pollution and non-point source (NPS) pollution, we explored the methodology of Fluent and AQUATOX to simulate and predict the state of HMLA, and trophic index was used to assess the eutrophication state. Then, we use water compensation optimization and three scenarios to determine the optimal management methodology. Three scenarios include ecological restoration scenario, best management practices (BMPs) scenario, and a scenario combining both. Our results suggest that the maintenance of a healthy ecosystem with ecoremediation is necessary and the BMPs have a far-reaching effect on water reusing and NPS pollution control. This study has implications for eutrophication control and management under development for urbanization in China.

  19. Open Source Patient-Controlled Analgesic Pump Requirements Documentation.

    Science.gov (United States)

    Larson, Brian R; Hatcliff, John; Chalin, Patrice

    2013-01-01

    The dynamic nature of the medical domain is driving a need for continuous innovation and improvement in techniques for developing and assuring medical devices. Unfortunately, research in academia and communication between academics, industrial engineers, and regulatory authorities is hampered by the lack of realistic non-proprietary development artifacts for medical devices. In this paper, we give an overview of a detailed requirements document for a Patient-Controlled Analgesic (PCA) pump developed under the US NSF's Food and Drug Administration (FDA) Scholar-in-Residence (SIR) program. This 60+ page document follows the methodology outlined in the US Federal Aviation Administrations (FAA) Requirements Engineering Management Handbook (REMH) and includes a domain overview, use cases, statements of safety & security requirements, and formal top-level system architectural description. Based on previous experience with release of a requirements document for a cardiac pacemaker that spawned a number of research and pedagogical activities, we believe that the described PCA requirements document can be an important research enabler within the formal methods and software engineering communities.

  20. Mobile source emission control cost-effectiveness: Issues, uncertainties, and results

    Energy Technology Data Exchange (ETDEWEB)

    Wang, M.Q. [Argonne National Lab., IL (United States). Center for Transportation Research

    1994-12-01

    Emissions from mobile sources undoubtedly contribute to US urban air pollution problems. Consequently, mobile source control measures, ranging from vehicle emission standards to reducing vehicle travel, have been adopted or proposed to help attain air quality standards. To rank various mobile source control measures, various government agencies and private organizations calculate cost-effectiveness in dollars per ton of emissions reduced. Arguments for or against certain control measures are often made on the basis of the calculated cost-effectiveness. Yet, different studies may yield significantly different cost-effectiveness results, because of the various methodologies used and assumptions regarding the values of costs and emission reductions. Because of the methodological differences, the cost-effectiveness results may not be comparable between studies. Use of incomparable cost-effectiveness results may result in adoption of ineffective control measures. This paper first discusses some important methodological issues involved in cost-effectiveness calculation for mobile sources and proposes appropriate, systematic methods for dealing with these issues. Various studies have been completed recently to evaluate the cost-effectiveness of mobile source emission control measures. These studies resulted in wide variations in the cost-effectiveness for same control measures. Methodological assumptions used in each study are presented and, based on the proposed methods for cost-effectiveness calculation, adjustments are applied to the original estimates in each study to correct inappropriate methodological assumptions and to make the studies comparable. Finally, mobile source control measures are ranked on the basis of the adjusted cost-effectiveness estimates.

  1. Optimized Second-Order Dynamical Systems and Their RLC Circuit Models with PWL Controlled Sources

    Directory of Open Access Journals (Sweden)

    J. Brzobohaty

    2004-09-01

    Full Text Available Complementary active RLC circuit models with a voltage-controlledvoltage source (VCVS and a current-controlled current source (CCCSfor the second-order autonomous dynamical system realization areproposed. The main advantage of these equivalent circuits is the simplerelation between the state model parameters and their correspondingcircuit parameters, which leads also to simple design formulas.

  2. 40 CFR 63.1316 - PET and polystyrene affected sources-emissions control provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true PET and polystyrene affected sources... and Resins § 63.1316 PET and polystyrene affected sources—emissions control provisions. (a) The owner... paragraph (b) of this section. The owner or operator of an affected source producing polystyrene using...

  3. Mixed Waste Management Facility (MWMF) Old Burial Ground (OBG) source control technology and inventory study

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G.P.; Rehder, T.E.; Kanzleiter, J.P.

    1996-10-02

    This report has been developed to support information needs for wastes buried in the Burial Ground Complex. Information discussed is presented in a total of four individual attachments. The general focus of this report is to collect information on estimated source inventories, leaching studies, source control technologies, and to provide information on modeling parameters and associated data deficiencies.

  4. Increasing the sensitivity of controlled-source electromagnetics with synthetic aperture

    NARCIS (Netherlands)

    Fan, Y.; Snieder, R.; Slob, E.C.; Hunziker, J.W.; Singer, J.; Sheiman, J.; Rosenquist, M.

    2012-01-01

    Controlled-source electromagnetics (CSEM) has been used as a derisking tool in the hydrocarbon exploration industry. We apply the concept of synthetic aperture to the lowfrequency electromagnetic field in CSEM. Synthetic aperture sources have been used in radar imaging for many years. Using the synt

  5. Controlled-source interferometric redatuming by crosscorrelation and multidimensional deconvolution in elastic media

    NARCIS (Netherlands)

    Van der Neut, J.R.; Thorbecke, J.W.; Mehta, K.; Slob, E.C.; Wapenaar, C.P.A.

    2011-01-01

    Various researchers have shown that accurate redatuming of controlled seismic sources to downhole receiver locations can be achieved without requiring a velocity model. By placing receivers in a horizontal or deviated well and turning them into virtual sources, accurate images can be obtained even b

  6. Temperature and Humidity Independent Control Research on Ground Source Heat Pump Air Conditioning System

    Science.gov (United States)

    Chen, G.; Wang, L. L.

    Taking green demonstration center building air conditioning system as an example, this paper presents the temperature and humidity independent control system combined with ground source heat pump system, emphasis on the design of dry terminal device system, fresh air system and ground source heat pump system.

  7. Model Predictive Control of Z-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    2011-01-01

    This paper presents Model Predictive Control (MPC) of Z-source Neutral Point Clamped (NPC) inverter. For illustration, current control of Z-source NPC grid-connected inverter is analyzed and simulated. With MPC’s advantage of easily including system constraints, load current, impedance network...... inductor current, capacitor voltage as well as switching frequency, transient response are all regulated as subjecting to constraints of this control method. The quality of output waveform, stability of impedance-network, level constraint of variable switching frequency as well as robustness of transient...... response are obtained at the same time with a formulated Z-source NPC inverter network model. Operation steady state and transient state simulation results of MPC are going to be presented, which shows good reference tracking ability of this method. It provides new control method for Z-source NPC inverter...

  8. Monitoring and design of stormwater control basins

    Science.gov (United States)

    Veenhuis, J.E.; Parrish, J.H.; Jennings, M.E.

    1989-01-01

    The City of Austin, Texas, has played a pioneering role in the control of urban nonpoint source pollution by enacting watershed and stormwater ordinances, overseeing detailed monitoring programs, and improving design criteria for stormwater control methods. The effectiveness of the methods used in Austin, and perhaps in other areas of the United States, to protect urban water resources has not yet been fully established. Therefore, detailed monitoring programs capable of quantitatively determining the effectiveness of control methods and of stormwater ordinances, are required. The purpose of this report is to present an overview of the City of Austin's stormwater monitoring program, including previous monitoring programs with the U.S. Environmental Protection Agency and the U.S. Geological Survey, and to describe the relation of monitoring to design of stormwater control basins.

  9. Can non-point pollutions emissions from agriculture be regulated efficiently using input-output taxes?

    DEFF Research Database (Denmark)

    Hansen, Line Block; Hansen, Lars Gårn

    2012-01-01

    In many parts of Europe and North America, phosphorus loss from cultivated fields is threatening natural ecosystems. Though there are similarities to other non-point agricultural emissions like nitrogen that have been studied extensively, phosphorus is often characterized by the presence of large...... systems. Depending on the proportions of different types of farms in the agricultural sector, we find that an input-output tax system may be close to efficient, or in other cases must be supplemented with subsidy and manure reallocation schemes....

  10. Nonpoint Symmetry and Reduction of Nonlinear Evolution and Wave Type Equations

    Directory of Open Access Journals (Sweden)

    Ivan Tsyfra

    2015-01-01

    Full Text Available We study the symmetry reduction of nonlinear partial differential equations with two independent variables. We propose new ansätze reducing nonlinear evolution equations to system of ordinary differential equations. The ansätze are constructed by using operators of nonpoint classical and conditional symmetry. Then we find solution to nonlinear heat equation which cannot be obtained in the framework of the classical Lie approach. By using operators of Lie-Bäcklund symmetries we construct the solutions of nonlinear hyperbolic equations depending on arbitrary smooth function of one variable too.

  11. Note: Tormenta: An open source Python-powered control software for camera based optical microscopy

    Science.gov (United States)

    Barabas, Federico M.; Masullo, Luciano A.; Stefani, Fernando D.

    2016-12-01

    Until recently, PC control and synchronization of scientific instruments was only possible through closed-source expensive frameworks like National Instruments' LabVIEW. Nowadays, efficient cost-free alternatives are available in the context of a continuously growing community of open-source software developers. Here, we report on Tormenta, a modular open-source software for the control of camera-based optical microscopes. Tormenta is built on Python, works on multiple operating systems, and includes some key features for fluorescence nanoscopy based on single molecule localization.

  12. Procedures for identifying reasonably available control technology for stationary sources of PM-10. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, M.J.; Ellefson, R.

    1992-09-01

    The guidance document sets forth procedures and identifies sources of information that will assist State and local air pollution control agencies in determining Reasonably Available Control Technology (RACT) for PM-10 (particulate matter having a nominal aerometric diameter of 10 microns or less) emission from existing stationary sources on a case-by-case basis. It provides an annotated bibliography of documents to aid in identifying the activities that cause PM-10 emissions as well as applicable air pollution control measures and their effectiveness in reducing emissions. The most stringent state total particulate matter (PM) emission limits are identified for several categories of PM-10 sources and compared to available emission test data. Finally, guidance is provided on procedures for estimating total capital investment and total annual cost of the control measures which are generally used to control PM-10 emissions.

  13. WATER QUALITY MODELING AND POLLUTION CONTROL FOR THE EASTERN ROUTE OF SOUTH TO NORTH WATER TRANSFER PROJECT IN CHINA

    Institute of Scientific and Technical Information of China (English)

    WANG Chao; WANG Yan-ying; WANG Pei-fang

    2006-01-01

    South to North Water Transfer Project in China is the largest project over centuries to solve the water shortage problem in vast areas of northern China. It comprises of three routes: the eastern, central and western route and this study mainly focused on the eastern route. As water quality is the key factor for the eastern route, this paper examined the main factors influencing water quality of the main route south of the Yellow River, by investigating the point source, non-point source (diffusive source) and internal source pollutions along the main eastern route and in its drainage basins, and assessing the current water quality in the waterways. According to the complicated and combined systems of rivers and lakes in this route, one-dimensional water quantity and quality model for rivers and two-dimensional model for lakes were developed to simulate the hydrodynamic and pollutant transport processes. The numerical method and model algorithm were described. The values of model parameters were estimated by using field-monitoring data along the main route and the inverse modeling technique. Established models were employed to predict the degradations of CODMn and NH4+-N in the main stream, under the conditions of current pollution loads and different hydrologic conditions. Schemes were present for controlling total quantities of pollutants from point source and non-point source along the main route to secure water quality for the eastern route.

  14. Congestion control for ATM multiplexers using neural networks:multiple sources/single buffer scenario

    Institute of Scientific and Technical Information of China (English)

    杜树新; 袁石勇

    2004-01-01

    A new neural network based method for solving the problem of congestion control arising at the user network interface (UNI) of ATM networks is proposed in this paper. Unlike the previous methods where the coding rate for all traffic sources as controller output signals is tuned in a body, the proposed method adjusts the coding rate for only a part of the traffic sources while the remainder sources send the cells in the previous coding rate in case of occurrence of congestion. The controller output signals include the source coding rate and the percentage of the sources that send cells at the corresponding coding rate. The control methods not only minimize the cell loss rate but also guarantee the quality of information (such as voice sources) fed into the multiplexer buffer. Simulations with 150 ADPCM voice sources fed into the multiplexer buffer showed that the proposed methods have advantage over the previous methods in the aspect of the performance indices such as cell loss rate (CLR) and voice quality.

  15. Temporal dynamics and potential neural sources of goal conduciveness, control, and power appraisal.

    Science.gov (United States)

    Gentsch, Kornelia; Grandjean, Didier; Scherer, Klaus R

    2015-12-01

    A major emotion theory, the Component Process Model, predicts that emotion-antecedent appraisal proceeds sequentially (e.g., goal conduciveness>control>power appraisal). In a gambling task, feedback manipulated information about goal conduciveness (outcome: win, loss), control (perceived high and low control), and power appraisals (choice options to change the outcome). Using mean amplitudes of event-related potentials, we examine the sequential prediction of these appraisal criteria. Additionally, we apply source localization analysis to estimate the neural sources of the evoked components of interest. Early ERPs (230-300 ms) show main effects of goal conduciveness and power but no interaction effects suggesting goal obstructiveness assessment of task-relevant feedback information. Late ERPs (350-600 ms) reveal main effects of all appraisals and interaction effects representing the integration of all appraisal information. Source localization analysis suggests distinct neural sources for these appraisal criteria. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Two Model-Based Methods for Policy Analyses of Fine Particulate Matter Control in China: Source Apportionment and Source Sensitivity

    Science.gov (United States)

    Li, X.; Zhang, Y.; Zheng, B.; Zhang, Q.; He, K.

    2013-12-01

    Anthropogenic emissions have been controlled in recent years in China to mitigate fine particulate matter (PM2.5) pollution. Recent studies show that sulfate dioxide (SO2)-only control cannot reduce total PM2.5 levels efficiently. Other species such as nitrogen oxide, ammonia, black carbon, and organic carbon may be equally important during particular seasons. Furthermore, each species is emitted from several anthropogenic sectors (e.g., industry, power plant, transportation, residential and agriculture). On the other hand, contribution of one emission sector to PM2.5 represents contributions of all species in this sector. In this work, two model-based methods are used to identify the most influential emission sectors and areas to PM2.5. The first method is the source apportionment (SA) based on the Particulate Source Apportionment Technology (PSAT) available in the Comprehensive Air Quality Model with extensions (CAMx) driven by meteorological predictions of the Weather Research and Forecast (WRF) model. The second method is the source sensitivity (SS) based on an adjoint integration technique (AIT) available in the GEOS-Chem model. The SA method attributes simulated PM2.5 concentrations to each emission group, while the SS method calculates their sensitivity to each emission group, accounting for the non-linear relationship between PM2.5 and its precursors. Despite their differences, the complementary nature of the two methods enables a complete analysis of source-receptor relationships to support emission control policies. Our objectives are to quantify the contributions of each emission group/area to PM2.5 in the receptor areas and to intercompare results from the two methods to gain a comprehensive understanding of the role of emission sources in PM2.5 formation. The results will be compared in terms of the magnitudes and rankings of SS or SA of emitted species and emission groups/areas. GEOS-Chem with AIT is applied over East Asia at a horizontal grid

  17. Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

    Science.gov (United States)

    Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

    1996-01-01

    An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

  18. Improvement of efficiency and temperature control of induction heating vapor source on electron cyclotron resonance ion source.

    Science.gov (United States)

    Takenaka, T; Kiriyama, R; Muramatsu, M; Kitagawa, A; Uchida, T; Kurisu, Y; Nozaki, D; Yano, K; Yoshida, Y; Sato, F; Kato, Y; Iida, T

    2012-02-01

    An electron cyclotron resonance ion source (ECRIS) is used to generate multicharged ions for many kinds of the fields. We have developed an evaporator by using induction heating method that can generate pure vapor from solid state materials in ECRIS. We develop the new matching and protecting circuit by which we can precisely control the temperature of the induction heating evaporator. We can control the temperature within ±15 °C around 1400 °C under the operation pressure about 10(-4) Pa. We are able to use this evaporator for experiment of synthesizing process to need pure vapor under enough low pressure, e.g., experiment of generation of endohedral Fe-fullerene at the ECRIS.

  19. Active and reactive power control of a current-source PWM-rectifier using space vectors

    Energy Technology Data Exchange (ETDEWEB)

    Salo, M.; Tuusa, H. [Tampere University of Technology (Finland). Department of Electrical Engineering, Power Electronics

    1997-12-31

    In this paper the current-source PWM-rectifier with active and reactive power control is presented. The control system is realized using space vector methods. Also, compensation of the reactive power drawn by the line filter is discussed. Some simulation results are shown. (orig.) 8 refs.

  20. Expedience of using reactive power sources installed in an MV grid for V and Q control

    Directory of Open Access Journals (Sweden)

    Robert Małkowski

    2012-09-01

    Full Text Available The paper contains comments on the expedience, feasibility, and potential manner of using reactive power sources for V and Q control in an MV grid. Also indicated is the expedience of quality control verifi cation of 110 kV / MV transformers supplying the grid.

  1. Six-Phase Vehicular Drive with Renewable DC Sources and Hybrid PWM Control of Four Inverters

    DEFF Research Database (Denmark)

    Oleschuk, Valentin; Ermuratskii, Vladimir; Blaabjerg, Frede

    2015-01-01

    The paper presents results of research of quad-inverter-based automotive system with combined scheme of PWM control of inverters, supplied by two renewable dc sources (by fuel cells and by battery). It has been shown, that hybrid switching techniques can be used successfully for control of vehicle...

  2. Sources and mitigation of interharmonics in back-to-back controllable drives

    DEFF Research Database (Denmark)

    Soltani, Hamid; Loh, Poh Chiang; Blaabjerg, Frede

    2014-01-01

    The theme here is to identify the sources of interharmonics that can affect back-to-back controllable drives and make non-characteristic interharmonic components in the grid side currents when the motor currents are unbalanced. A new control methodology then is formulated and proposed to compensate...... for the sources, leading to undistorted grid currents, which are growingly important as more drives are tied to the grid. It is shown that in the case of back-to-back controllable drives it is possible to reduce the input current interharmonic distortion caused by motor current imbalance....

  3. A low noise modular current source for stable magnetic field control

    Science.gov (United States)

    Biancalana, Valerio; Bevilacqua, Giuseppe; Chessa, Piero; Dancheva, Yordanka; Cecchi, Roberto; Stiaccini, Leonardo

    2017-03-01

    A low cost, stable, programmable, unipolar current source is described. The circuit is designed in view of a modular arrangement, suitable for applications where several DC sources must be controlled at once. A hybrid switching/linear design helps in improving the stability and in reducing the power dissipation and cross-talking. Multiple units can be supplied by a single DC power supply, while allowing for a variety of maximal current values and compliance voltages at the outputs. The circuit is analogically controlled by a unipolar voltage, enabling current programmability and control through commercial digital-to-analogue conversion cards.

  4. A Comparative Study of Control Methods for Induction Motor and High Performance Z-source Inverter

    Directory of Open Access Journals (Sweden)

    Pham Cong Thanh

    2013-06-01

    Full Text Available Design studies of the most suitable controller for the speed of induction motor (SIM and peak DC-link voltage (PDV of high performance z-source inverter (HP-ZSI greatly affects performance of hybrid electric vehicles. This paper is to give comprehensive analyses comparison and evaluations of the different control techniques as PI controller, self-tuning fuzzy PI controller (SFP and genetic algorithms optimal tuning gains of the PI controller for controlling the SIM based on criteria of the integral of the absolute value of speed error. With control PDV, this paper also presents comparisons of the different techniques as PI controller, fuzzy logic controller, SFP based on observation of its response and total harmonic distortion of current. All methods are applied to the closed loop of the SIM which relies on direct torque control combined with modified space vector modulation and closed loop of PDV in HP-ZSI. These methods are verified by Matlab software.

  5. Design of Programmable LED Controller with a Variable Current Source for 3D Image Display

    Directory of Open Access Journals (Sweden)

    Kyung-Ryang Lee

    2014-12-01

    Full Text Available Conventional fluorescent light sources, as well as incandescent light sources are gradually being replaced by Light Emitting Diodes (LEDs for reducing power consumption in the image display area for multimedia application. An LED light source requires a controller with a low-power operation. In this paper, a low-power technique using adiabatic operation is applied for the implementation of LED controller with a stable constant-current, a low-power and low-heat function. From the simulation result, the power consumption of the proposed LED controller using adiabatic operation was reduced to about 87% in comparison with conventional operation with a constant VDD. The proposed circuit is expected to be an alternative LED controller which is sensitive to external conditions such as heat.

  6. Sources

    OpenAIRE

    2015-01-01

    SOURCES MANUSCRITES Archives nationales Rôles de taille 1768/71 Z1G-344/18 Aulnay Z1G-343a/02 Gennevilliers Z1G-340/01 Ivry Z1G-340/05 Orly Z1G-334c/09 Saint-Remy-lès-Chevreuse Z1G-344/18 Sevran Z1G-340/05 Thiais 1779/80 Z1G-391a/18 Aulnay Z1G-380/02 Gennevilliers Z1G-385/01 Ivry Z1G-387b/05 Orly Z1G-388a/09 Saint-Remy-lès-Chevreuse Z1G-391a/18 Sevran Z1G-387b/05 Thiais 1788/89 Z1G-451/18 Aulnay Z1G-452/21 Chennevières Z1G-443b/02 Gennevilliers Z1G-440a/01 Ivry Z1G-452/17 Noiseau Z1G-445b/05 ...

  7. Co-control of source and heat: the generation and distribution of hydrocarbons controlled by source rocks and heat%源热共控论

    Institute of Scientific and Technical Information of China (English)

    张功成

    2012-01-01

    Hydrocarbon generation is co-controlled by source rocks and heat, which are internal and external controlling factors, respectively. The combination of these two factors controls the generation, scale, phase (oil or gas) behavior and regional distribution pattern of hydrocarbons. The controlling factors of potential hydrocarbon source rocks include the type, abundance and scale of source rocks. Their heat field consists of hot, warm and cold models and there are 3 types of thermal evolution, I. E. Temperature-increasing, temperature-decreasing and complex multi-episode types. In potential hydrocarbon-generating sags, there are 4 kinds of combination between source rocks and heat, namely sufficient source and heat, sufficient source but deficient heat, deficient source but sufficient heat, and deficient source and heat. The sufficient source and heat combination can form hydrocarbon-generating sags including hydrocarbon-prolific or hydrocarbon-bearing sags, and the sufficient source but deficient heat combination or the deficient source but sufficient heat combination can also form hydrocarbon-generating or hydrocarbon-prolific sags on condition that source and heat can complement each other, while the deficient source and heat combination can not form hydrocarbon-bearing sags. In a hydrocarbon province co-controlled by source and heat, oil, gas or oil-gas layers generally have a spatially ordered distribution, which is characterized vertically by a lower oil and upper gas pattern or a lower gas and upper oil pattern, and laterally hy an inner and outer belt pattern, an inner and outer circle pattern, or a zoning pattern. The scale of hydrocarbon reserves in this hydrocarbon province depends mainly on the development of the sufficient source and heat sag, and hydrocarbon-bearing basins in China can be roughly classified into extra-prolific, prolific, medium, small and poor hydrocarbon-bearing basins.%源热共控油气形成,潜在烃源岩是油气形成的内因,

  8. Solute source depletion control of forward and back diffusion through low-permeability zones

    Science.gov (United States)

    Yang, Minjune; Annable, Michael D.; Jawitz, James W.

    2016-10-01

    Solute diffusive exchange between low-permeability aquitards and high-permeability aquifers acts as a significant mediator of long-term contaminant fate. Aquifer contaminants diffuse into aquitards, but as contaminant sources are depleted, aquifer concentrations decline, triggering back diffusion from aquitards. The dynamics of the contaminant source depletion, or the source strength function, controls the timing of the transition of aquitards from sinks to sources. Here, we experimentally evaluate three archetypical transient source depletion models (step-change, linear, and exponential), and we use novel analytical solutions to accurately account for dynamic aquitard-aquifer diffusive transfer. Laboratory diffusion experiments were conducted using a well-controlled flow chamber to assess solute exchange between sand aquifer and kaolinite aquitard layers. Solute concentration profiles in the aquitard were measured in situ using electrical conductivity. Back diffusion was shown to begin earlier and produce larger mass flux for rapidly depleting sources. The analytical models showed very good correspondence with measured aquifer breakthrough curves and aquitard concentration profiles. The modeling approach links source dissolution and back diffusion, enabling assessment of human exposure risk and calculation of the back diffusion initiation time, as well as the resulting plume persistence.

  9. Power Controllability of Three-phase Converter with Unbalanced AC Source

    DEFF Research Database (Denmark)

    Ma, Ke; Liserre, Marco; Blaabjerg, Frede

    2013-01-01

    Three-phase DC-AC power converters suffer from power oscillation and overcurrentt problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence...... converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC sources....... currents. In this work a new series of control strategies which utilize the zero-sequence components are proposed to enhance the power control ability under this adverse conditions. It is concluded that by introducing proper zero sequence current controls and corresponding circuit configurations, the power...

  10. External Carbon Source Addition as a Means to Control an Activated Sludge Nutrient Removal Process

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard; Henze, Mogens; Søeberg, Henrik

    1994-01-01

    In alternating type activated sludge nutrient removal processes, the denitrification rate can be limited by the availability of readily-degradable carbon substrate. A control strategy is proposed by which an easily metabolizable COD source is added directly to that point in the process at which...... denitrification momentarily occurs. This approach serves to increase the denitrification rate on demand, thereby allowing the accumulation of nitrate and nitrite during periods of peak nitrogen loading to be reduced or avoided. A pilot plant demonstration of the control strategy using acetate as COD source...

  11. Parsing pyrogenic polycyclic aromatic hydrocarbons: forensic chemistry, receptor models, and source control policy.

    Science.gov (United States)

    O'Reilly, Kirk T; Pietari, Jaana; Boehm, Paul D

    2014-04-01

    A realistic understanding of contaminant sources is required to set appropriate control policy. Forensic chemical methods can be powerful tools in source characterization and identification, but they require a multiple-lines-of-evidence approach. Atmospheric receptor models, such as the US Environmental Protection Agency (USEPA)'s chemical mass balance (CMB), are increasingly being used to evaluate sources of pyrogenic polycyclic aromatic hydrocarbons (PAHs) in sediments. This paper describes the assumptions underlying receptor models and discusses challenges in complying with these assumptions in practice. Given the variability within, and the similarity among, pyrogenic PAH source types, model outputs are sensitive to specific inputs, and parsing among some source types may not be possible. Although still useful for identifying potential sources, the technical specialist applying these methods must describe both the results and their inherent uncertainties in a way that is understandable to nontechnical policy makers. The authors present an example case study concerning an investigation of a class of parking-lot sealers as a significant source of PAHs in urban sediment. Principal component analysis is used to evaluate published CMB model inputs and outputs. Targeted analyses of 2 areas where bans have been implemented are included. The results do not support the claim that parking-lot sealers are a significant source of PAHs in urban sediments. © 2013 SETAC.

  12. Power system monitoring and source control of the Space Station Freedom DC power system testbed

    Science.gov (United States)

    Kimnach, Greg L.; Baez, Anastacio N.

    1992-01-01

    Unlike a terrestrial electric utility which can purchase power from a neighboring utility, the Space Station Freedom (SSF) has strictly limited energy resources; as a result, source control, system monitoring, system protection, and load management are essential to the safe and efficient operation of the SSF Electric Power System (EPS). These functions are being evaluated in the DC Power Management and Distribution (PMAD) Testbed which NASA LeRC has developed at the Power System Facility (PSF) located in Cleveland, Ohio. The testbed is an ideal platform to develop, integrate, and verify power system monitoring and control algorithms. State Estimation (SE) is a monitoring tool used extensively in terrestrial electric utilities to ensure safe power system operation. It uses redundant system information to calculate the actual state of the EPS, to isolate faulty sensors, to determine source operating points, to verify faults detected by subsidiary controllers, and to identify high impedance faults. Source control and monitoring safeguard the power generation and storage subsystems and ensure that the power system operates within safe limits while satisfying user demands with minimal interruptions. System monitoring functions, in coordination with hardware implemented schemes, provide for a complete fault protection system. The objective of this paper is to overview the development and integration of the state estimator and the source control algorithms.

  13. Control Strategy for Three Phase Voltage Source PWM Rectifier Based on the Space Vector Modulation

    Directory of Open Access Journals (Sweden)

    MILOUD, Y.

    2010-08-01

    Full Text Available This paper proposes the space vector pulse width modulation (SVPWM control scheme for three-phase voltage source PWM rectifier. The control system based on SVPWM includes two PI controllers which are used to regulate the AC currents and DC-link voltage. The proposed control can stabilize the minimum of the systems storage function at the desired equilibrium point determined by unity power factor and sinusoidal current on the AC side, and constant output voltage on the DC side. So the stable state performance and robustness against the load�s disturbance of PWM rectifiers are both improved. The simulation result shows feasibility of this strategy.

  14. An Approach to Develop Embedded System For Web Based Monitoring & Controlling of Renewable Energy Sources

    Directory of Open Access Journals (Sweden)

    Akansha S. Fating

    2013-06-01

    Full Text Available The widespread application of Renewable Energy Sources (RESrequires centralized monitoring and controlling System. To makethese operations control room independent, there is need todevelop smart servers and web based applications. Cost is anessential factor of any embedded system design. This paperdiscusses a novel concept of designing of cost effective server/client embedded system Renewable Energy sources. Hereembedded server is developed with ARM9 controller loaded withwindows CE operating system. Low cost client are designedusing Atmega32 microcontroller with LAN connection. Server/client are connected in LAN system and server basedapplications has been developed to monitor/ controlling the clientoperation. The server has web based applications that can beaccessed via internet. Author has presented developed systemand results.

  15. Control system renewal for efficient operation in RIKEN 18 GHz electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, A., E-mail: a-uchi@riken.jp; Ozeki, K.; Higurashi, Y.; Kidera, M.; Komiyama, M.; Nakagawa, T. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2016-02-15

    A RIKEN 18 GHz electron cyclotron resonance ion source (18 GHz ECRIS) is used as an external ion source at the Radioactive Ion Beam Factory (RIBF) accelerator complex to produce an intense beam of medium-mass heavy ions (e.g., Ca and Ar). In most components that comprise the RIBF, the control systems (CSs) are integrated by the Experimental Physics and Industrial Control System (EPICS). On the other hand, a non-EPICS-based system has hardwired controllers, and it is used in the 18 GHz ECRIS CS as an independent system. In terms of efficient and effective operation, the 18 GHz ECRIS CS as well as the RIBF CS should be renewed using EPICS. Therefore, we constructed an 18 GHz ECRIS CS by using programmable logic controllers with embedded EPICS technology. In the renewed system, an operational log system was developed as a new feature, for supporting of the 18 GHz ECRIS operation.

  16. A source-based congestion control strategy for real-time video transport on IP network

    Science.gov (United States)

    Chen, Xia; Cai, Canhui

    2005-07-01

    The goal of this paper is to design a TCP friendly real-time video transport protocol that will not only utilize network resource efficiently, but also prevent network congestion from the real-time video transmitting effectively. To this end, we proposed a source based congestion control scheme to adapt video coding rate to the channel capacity of the IP network, including three stages: rate control, rate-adaptive video encoding, and rate shaping.

  17. Can non-point phosphorus emissions from agriculture be regulated efficiently using input-output taxes?

    DEFF Research Database (Denmark)

    Hansen, Line Bloch; Hansen, Lars Gårn

    In many parts of Europe and North America, phosphorus loss from cultivated fields is threatening natural ecosystems. Though there are similarities to other non-point agricultural emissions like nitrogen that have been studied extensively, phosphorus is often characterised by the presence of large...... stocking capacities for phosphorus in farm soils and long time-lags between applications and emission. This makes it important to understand the dynamics of the phosphorus emission problem when designing regulatory systems. Using a model that reflects these dynamics, we evaluate alternative regulatory...... systems. Depending on the proportions of different types of farms in the agricultural sector, we find that an input-output tax system may be close to efficient, or in other cases must be supplemented with subsidy and manure reallocation schemes....

  18. Control strategy of fuel cell/supercapacitors hybrid power sources for electric vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Thounthong, Phatiphat; Raeel, Stephane; Davat, Bernard [Institut National Polytechnique de Lorraine (INPL), GREEN, CNRS (UMR 7037) 2, Avenue de la Foret de Haye, 54516 Vandoeuvre-les-Nancy (France)

    2006-07-14

    This paper presents a control principle for utilizing PEM fuel cell as main power source and supercapacitors as auxiliary power source for electric vehicle applications. The strategy is based on dc link voltage regulation, and fuel cell is simply operating in almost steady state conditions in order to minimize the mechanical stresses of fuel cell and to ensure a good synchronization between fuel flow and fuel cell current. Supercapacitors are functioning during transient energy delivery or transient energy recovery. To authenticate control algorithms, the system structure is realized by analogical current loops and digital voltage loops (dSPACE). The experimental results with a 500W PEM fuel cell point out the fuel cell starvation problem when operating with dynamic load, and also confirm that the supercapacitor can improve system performance for hybrid power sources. (author)

  19. Computer simulation of short-circuiting transfer welding under waveform control on inverter power source

    Institute of Scientific and Technical Information of China (English)

    Yang Lijun; Feng Shengqiang; Dong Tianshun; Li Huan

    2007-01-01

    A simulation model is introduced about the non-linearity process of short-circuiting transfer in CO2 arc welding for displaying the interaction between the inverter power source and welding arc under waveform control. In the simulation model, the feedback signals of current and voltage are taken respectively at the different phase in a short circuit periodic time and applied to the PWM(pulse width modulation) module in a model of inverter power source to control the output of power source. The simulation operation about the dynamic process of CO2 short-circuiting transfer welding is implemented on the founded simulation model with a peak arc current of 400 A and a peak voltage of 35 V, producing the dynamic arc waveforms which can embody the effect of inverter harmonic wave. The simulating waveforms are close to that of welding experiments.

  20. Variable speed wind turbine generator system with current controlled voltage source inverter

    Energy Technology Data Exchange (ETDEWEB)

    Muyeen, S.M., E-mail: muyeen0809@yahoo.co [Dept. of Electrical Engineering, Petroleum Institute, P.O. Box 2533, Abu Dhabi (United Arab Emirates); Al-Durra, Ahmed [Dept. of Electrical Engineering, The Petroleum Institute, P.O. Box 2533, Abu Dhabi (United Arab Emirates); Tamura, J. [Dept. of EEE, Kitami Institute of Technology, 165 Koen-cho, Kitami 090-8507 (Japan)

    2011-07-15

    highlights: {yields} Current controlled voltage source inverter scheme for wind power application. {yields} Low voltage ride through of wind farm. {yields} Variable speed wind turbine driven permanent magnet synchronous generator-operation and control. -- Abstract: The present popular trend of wind power generation is to use variable speed wind turbine (VSWT) driving a doubly fed induction generator (DFIG), wound field synchronous generator (WFSG) or permanent magnet synchronous generator (PMSG). Among them, stability analyses of DFIG type of VSWT have already been reported in many literatures. However, transient stability and low voltage ride through (LVRT) characteristics analyses for synchronous generator type of VSWT is not sufficient enough. This paper focuses on detailed LVRT characteristic analysis of variable speed wind turbine driving a PMSG (VSWT-PMSG) with current controlled voltage source inverter (CC-VSI). Modeling and suitable control strategies for overall system are developed to augment the low voltage ride through capability of variable speed wind generator, considering recent wind farm grid code. Both symmetrical and unsymmetrical faults are analyzed as network disturbances in this paper. The permanent fault due to unsuccessful reclosing of circuit breakers is taken into consideration, which is a salient feature of this study. Moreover, the dynamic characteristic is analyzed using real wind speed data measured in Hokkaido Island, Japan. The proposed control scheme is simulated by using the standard power system simulation package PSCAD/EMTDC and results are verified by comparing that of voltage controlled voltage source inverter scheme available in power system literature.

  1. Flat acoustic sources with frequency response correction based on feedback and feed-forward distributed control.

    Science.gov (United States)

    Ho, Jen-Hsuan; Berkhoff, Arthur P

    2015-04-01

    This paper presents an acoustic source with a small thickness and high bending stiffness. The high bending stiffness is obtained with a sandwich structure in which the face of the sandwich structure internal to the source is perforated to increase the acoustic compliance, thereby leading to increased electroacoustic conversion efficiency. Multiple actuators are used to drive the moving component of the acoustic source. Control of the acoustic resonances and structural resonances is required to obtain an even frequency response. The use of collocated decentralized feedback control based on velocity sensing was found to be ineffective for controlling these resonances due to the destabilizing asymmetric modes caused by the coupling of the internal acoustic cavity and the rigid body vibration of the moving component. Resonances can be controlled by a set of independent combinations of symmetric driving patterns with corresponding velocity feedback controllers such that the fundamental mass-air resonance is effectively controlled, as is the lowest bending mode of the moving component. Finally, a compensation scheme for low frequencies is used which enables a flat frequency response in the range of 30 Hz to 1 kHz with deviations smaller than 3 dB.

  2. National Conference on Mining-Influenced Waters: Approaches for Characterization, Source Control and Treatment

    Science.gov (United States)

    The conference goal was to provide a forum for the exchange of scientific information on current and emerging approaches to assessing characterization, monitoring, source control, treatment and/or remediation on mining-influenced waters. The conference was aimed at mining remedi...

  3. Air pollutants contribution and control strategies of energy-use related sources in Beijing

    Institute of Scientific and Technical Information of China (English)

    HAO; Jiming; WANG; Litao; LI; Lin; HU; Jingnan; YU; Xuechun

    2005-01-01

    Based on the statistical analysis of emission inventory and ISCST3 model simulation, the emission and ambient concentration contributions of energy-use related sources to the major pollutants of SO2, NOx and PM10 in urban areas of Beijing were analyzed. The SO2 emission contributions of coal burning in power plants, industrial and heating sectors were 49%, 26% and 24% respectively. The vehicle exhaust contributed 74% of the NOx concentration. As to PM10, the industrial sector was the largest emission (28%) and concentration (21%) contributor despite of the fugitive sources. The source emission contributions of VOC and NH3, which greatly influence the generation of secondary pollutants, were discussed as well. This paper also analyzed the control strategies of energy consumption and vehicle sources, based on which the control scenario in 2008 was established and the change of emission and concentration contribution were estimated. The results show that the cleaner energy use, industrial structure improvement, transportation mode modification and single vehicle emission control will greatly improve air quality. The industrial sector will change to the largest contributor of SO2 and as to NOx, vehicle emission control is still important.

  4. Control of mercury emissions from stationary coal combustion sources in China: Current status and recommendations.

    Science.gov (United States)

    Hu, Yuanan; Cheng, Hefa

    2016-11-01

    Coal burning in power plants and industrial boilers is the largest combustion source of mercury emissions in China. Together, power plants and industrial boilers emit around 250 tonnes of mercury each year, or around half of atmospheric mercury emissions from anthropogenic sources in the country. Power plants in China are generally equipped with multi-pollutant control technologies, which offer the co-benefit of mercury removal, while mercury-specific control technologies have been installed in some facilities. In contrast, most industrial boilers have only basic or no flue gas cleaning. A combination of measures, including energy conservation, coal switching and blending, reducing the mercury contents of coals through washing, combustion controls, and flue gas cleaning, can be used to reduce mercury emissions from these stationary combustion sources. More stringent emission standards for the major air pollutants from coal-fired power plants and industrial boiler, along with standards for the previously unregulated mercury, were implemented recently, which is expected to bring significant reduction in their mercury emissions through the necessary upgrades of multi-pollutant and mercury-specific control technologies. Meanwhile, strong monitoring capacity and strict enforcement are necessary to ensure that the combustion sources operate in compliance with the new emission standards and achieve significant reduction in the emissions of mercury and other air pollutants.

  5. 1D inversion and analysis of marine controlled-source EM data

    DEFF Research Database (Denmark)

    Christensen, N.B.; Dodds, Kevin; Bulley, Ian

    2006-01-01

    Marine Controlled-source electromagnetic data are now routinely collected over promising oil and gas prospects identified by seismic investigations. They allow an identification of resistive layers at depth, thereby pointing to possible oil and gas bearing sediments, where conductive salt water h...

  6. 75 FR 15655 - Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air...

    Science.gov (United States)

    2010-03-30

    ... AGENCY 40 CFR Part 63 RIN 2060-AP91 Requirements for Control Technology Determinations for Major Sources... Division, Office of Air Quality Planning and Standards (D205- 02), Environmental Protection Agency... facilities. Brick and Structural Clay Products; Clay 327122 Ceramic wall and floor tile manufacturing...

  7. Redatuming controlled-source electromagnetic data using Stratton–Chu type integral transformations

    DEFF Research Database (Denmark)

    Zhdanov, Michael; Cai, Hongzhu

    2016-01-01

    We present a new method of analyzing controlled-source electromagnetic (CSEM) data based on redatuming of the observed data from the actual receivers into the virtual receivers. We use the Stratton–Chu type integral transform to calculate the EM field in the virtual receivers. The virtual receivers...

  8. Microfocus x-ray imaging of traceable pointlike {sup 22}Na sources for quality control

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, T.; Oda, K.; Sato, Y.; Ito, H.; Masuda, S.; Yamada, T.; Matsumoto, M.; Murayama, H.; Takei, H. [Allied Health Sciences, Kitasato University Kitasato 1-15-1, Minami-ku, Sagamihara-shi, Kanagawa 252-0373 (Japan); Positron Medical Center, Tokyo Metropolitan Institute of Gerontology Sakaecho 35-2, Itabashi-ku, Tokyo 173-0015 (Japan); Advanced Industrial Science and Technology (AIST) Central 2, Umezono 1-1-1, Tsukuba-shi, Ibaraki 305-8568 (Japan); Kanagawa Industrial Technology Center (KITC) Shimoimazumi 705-1, Ebina-shi, Kanagawa 243-0435 (Japan); Japan Radioisotope Association (JRIA) Komagome 2-28-45, Bunkyo-ku, Tokyo 113-8941 (Japan); Molecular Imaging Center, National Institute of Radiological Sciences Anagawa 4-9-1, Inage, Chiba 263-8555 (Japan); Graduate School of Medical Sciences, Kitasato University Kitasato 1-15-1, Minami-ku, Sagamihara-shi, Kanagawa 252-0373 (Japan)

    2012-07-15

    Purpose: The purpose of this study is to propose a microfocus x-ray imaging technique for observing the internal structure of small radioactive sources and evaluating geometrical errors quantitatively, and to apply this technique to traceable pointlike {sup 22}Na sources, which were designed for positron emission tomography calibration, for the purpose of quality control of the pointlike sources. Methods: A microfocus x-ray imaging system with a focus size of 0.001 mm was used to obtain projection x-ray images and x-ray CT images of five pointlike source samples, which were manufactured during 2009-2012. The obtained projection and tomographic images were used to observe the internal structure and evaluate geometrical errors quantitatively. Monte Carlo simulation was used to evaluate the effect of possible geometrical errors on the intensity and uniformity of 0.511 MeV annihilation photon pairs emitted from the sources. Results: Geometrical errors were evaluated with sufficient precision using projection x-ray images. CT images were used for observing the internal structure intuitively. As a result, four of the five examined samples were within the tolerance to maintain the total uncertainty below {+-}0.5%, given the source radioactivity; however, one sample was found to be defective. Conclusions: This quality control procedure is crucial and offers an important basis for using the pointlike {sup 22}Na source as a basic calibration tool. The microfocus x-ray imaging approach is a promising technique for visual and quantitative evaluation of the internal geometry of small radioactive sources.

  9. Design, Control, and Modeling of a New Voltage Source Converter for HVDC System

    Science.gov (United States)

    Mohan, Madhan; Singh, Bhim; Ketan Panigrahi, Bijaya

    2013-05-01

    Abstract: A New Voltage Source Converter (VSC) based on neutral clamped three-level circuit is proposed for High Voltage DC (HVDC) system. The proposed VSC is designed in a multipulse configuration. The converter is operated by Fundamental Frequency Switching (FFS). A new control method is developed for achieving all the necessary control aspects of HVDC system such as independent real and reactive power control, bidirectional real and reactive power control. The basic of the control method is varying the pulse width and by keeping the dc link voltage constant. The steady state and dynamic performances of HVDC system interconnecting two different frequencies network are demonstrated for active and reactive power control. Total number of transformers used in this system are reduced to half in comparison with the two-level VSCs for both active and reactive power control. The performance of the HVDC system is improved in terms of reduced harmonics level even at fundamental frequency switching. The harmonic performance of the designed converter is also studied for different value of the dead angle (β), and the optimized range of the dead angle is achieved for varying reactive power requirement. Simulation results are presented for the designed three level multipulse voltage source converters with the proposed control algorithm.

  10. Status of the advanced photon source and its accelerator control system

    Science.gov (United States)

    McDowell, W.; Knott, M.; Kraimer, M.

    1994-12-01

    This paper presents the current status of the Advanced Photon Source (APS), its control system and the Experimental Physics and Industrial Control System (EPICS) tools being used to implement this control system. The status of the physical plant and each of the accelerators as well as detailed descriptions of the software tools used to build the accelerator control system are presented. The control system uses high-performance graphic workstations and the X-Windows graphical user interface (GUI) at the operator interface level. It connects to VME/VXI-based microprocessors at the field level, using TCP/IP protocols over high-performance networks. This strategy assures the flexibility and expansibility of the control system. A defined interface between the system components will allow the system to evolve with the direct addition of future, improved equipment and new capabilities.

  11. Integrated watershed- and farm-scale modeling framework for targeting critical source areas while maintaining farm economic viability.

    Science.gov (United States)

    Ghebremichael, Lula T; Veith, Tamie L; Hamlett, James M

    2013-01-15

    Quantitative risk assessments of pollution and data related to the effectiveness of mitigating best management practices (BMPs) are important aspects of nonpoint source pollution control efforts, particularly those driven by specific water quality objectives and by measurable improvement goals, such as the total maximum daily load (TMDL) requirements. Targeting critical source areas (CSAs) that generate disproportionately high pollutant loads within a watershed is a crucial step in successfully controlling nonpoint source pollution. The importance of watershed simulation models in assisting with the quantitative assessments of CSAs of pollution (relative to their magnitudes and extents) and of the effectiveness of associated BMPs has been well recognized. However, due to the distinct disconnect between the hydrological scale in which these models conduct their evaluation and the farm scale at which feasible BMPs are actually selected and implemented, and due to the difficulty and uncertainty involved in transferring watershed model data to farm fields, there are limited practical applications of these tools in the current nonpoint source pollution control efforts by conservation specialists for delineating CSAs and planning targeting measures. There are also limited approaches developed that can assess impacts of CSA-targeted BMPs on farm productivity and profitability together with the assessment of water quality improvements expected from applying these measures. This study developed a modeling framework that integrates farm economics and environmental aspects (such as identification and mitigation of CSAs) through joint use of watershed- and farm-scale models in a closed feedback loop. The integration of models in a closed feedback loop provides a way for environmental changes to be evaluated with regard to the impact on the practical aspects of farm management and economics, adjusted or reformulated as necessary, and revaluated with respect to effectiveness of

  12. Optimal source rate control for adapting VBR video over CBR channels

    Institute of Scientific and Technical Information of China (English)

    Chunwen LI; Peng ZHU

    2006-01-01

    In this paper we discuss the source rate control problem of adapting variable bit-rate (VBR) compressed video over constant bit-rate (CBR) channels. Firstly we formulate it as an optimal control problem of a discrete linear system with state and control constraints. Then we apply the discrete maximum principle to get the optimal solution.Experimental results are given in the end. Compared with traditional algorithms, the proposed algorithm is suitable for the coder with continuous output rates, and can achieve the better solution. Our algorithm can be used in both off-line and on-line coding.

  13. A Survey on Open-Source Flight Control Platforms of Unmanned Aerial Vehicle

    DEFF Research Database (Denmark)

    Ebeid, Emad Samuel Malki; Skriver, Martin; Jin, Jie

    2017-01-01

    Recently, Unmanned Aerial Vehicle (UAV), so-called drones, have gotten a lot of attention in academic research and commercial applications due to their simple structure, ease of operations and low-cost hardware components. Flight controller, embedded electronics component, represents the core part...... of the drone. It aims at performing the main operations of the drone (e.g., autonomous control and navigation). There are various types of flight controllers and each of them has its own characteristics and features. This paper presents an extensive survey on the publicly available open-source flight...

  14. A Survey of Congestion Control in Proactive Source Routing Protocol in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Bhagyashree S kayarkar

    2014-12-01

    Full Text Available In mobile ad hoc networks (MANET congestion can take place between the two intermediate nodes, when the packet is transferred from the source to the destination. The congestion in MANET is mainly due to frequent change to topology and high mobility of nodes, which lead to high loss of packet. In ad hoc network the congestion control techniques with TCP becomes difficult to handle since in ad hoc network there is high density of nodes in the network and there is frequent change to topology in the network. In this paper to control the congestion in proactive source routing protocol an error message is generated by the receiver to reduce the packet sending rate. We are using a new control message i.e., Packet Error Announcing Message called (PEAM messages.

  15. Boundary control of bidomain equations with state-dependent switching source functions in the ionic model

    Science.gov (United States)

    Chamakuri, Nagaiah; Engwer, Christian; Kunisch, Karl

    2014-09-01

    Optimal control for cardiac electrophysiology based on the bidomain equations in conjunction with the Fenton-Karma ionic model is considered. This generic ventricular model approximates well the restitution properties and spiral wave behavior of more complex ionic models of cardiac action potentials. However, it is challenging due to the appearance of state-dependent discontinuities in the source terms. A computational framework for the numerical realization of optimal control problems is presented. Essential ingredients are a shape calculus based treatment of the sensitivities of the discontinuous source terms and a marching cubes algorithm to track iso-surface of excitation wavefronts. Numerical results exhibit successful defibrillation by applying an optimally controlled extracellular stimulus.

  16. A SURVEY OF CONGESTION CONTROL IN PROACTIVE SOURCE ROUTING PROTOCOL IN MOBILE AD HOC NETWORKS

    Directory of Open Access Journals (Sweden)

    Bhagyashree S kayarkar

    2015-10-01

    Full Text Available In mobile ad hoc networks (MANET congestion can take place between the two intermediate nodes, when the packet is transferred from the source to the destination. The congestion in MANET is mainly due to frequent change to topology and high mobility of nodes, which lead to high loss of packet. In ad hoc network the congestion control techniques with TCP becomes difficult to handle since in ad hoc network there is high density of nodes in the network and there is frequent change to topology in the network. In this paper to control the congestion in proactive source routing protocol an error message is generated by the receiver to reduce the packet sending rate. We are using a new control message i.e., Packet Error Announcing Message called (PEAM messages.

  17. Variable Voltage Source Inverter with controlled frequency spectrum based on Random Pulse Width Modulation

    Directory of Open Access Journals (Sweden)

    Muhammad Farrukh Yaqub

    2012-01-01

    Full Text Available This paper presents a new method for single phase variable voltage inverter based on Random Pulse Width Modulation. In Random Pulse Width Modulation based inverter, the frequency spectrum of the output current and voltage waveforms becomes continuous because of the randomization of the switching function of the devices controlling the output voltages. This paper establishes a theory that if the distributions of the random numbers generated by the random source are kept within certain limit with respect to the peak value of reference sinusoidal waveform, the frequency spectrum can be controlled. On the basis of the results, a novel drive using variable tap changing transformer (optional and adaptive random number generator, to control the ratio between the numbers generated by the random source and the reference waveform has been suggested that will guarantee a better power quality profile for a broad range of output voltages.

  18. Voltage Source Inverter/Converter for the Improvement of Power Quality Using Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    T Jagan Mohan Rao

    2014-05-01

    Full Text Available In recent years, the applications of power electronics have grown tremendously. These power electronic systems offer highly nonlinear characteristics. To overcome those non linearities active power filters are preferred. This paper presents and compares the performance of two controllers namely Fuzzy Logic and Proportional Integral (PI applied to a voltage source inverter / converter which operates as an active power filter. The active power filter is operated to compensate harmonics generated by the non-linear load . This work is done to make an accurate comparison of the performance of fuzzy logic controller and classical control technique such as PI controller in compensating harmonics in the ac mains current. Fuzzy control rule design is based on the general dynamic behavior of the process. A novel control method is implemented for suppressing the harmonics. The compensation process is instantaneous, which is achieved without employing any complicated control logic. The control scheme is based on sensing line currents only; an approach different from convention ones, which are based on sensing harmonics of the nonlinear load. In the control scheme a hysteresis controller based on current control is employed to generate switching signals to the PWM converter.

  19. Simple voltage-controlled current source for wideband electrical bioimpedance spectroscopy: circuit dependences and limitations

    Science.gov (United States)

    Seoane, F.; Macías, R.; Bragós, R.; Lindecrantz, K.

    2011-11-01

    In this work, the single Op-Amp with load-in-the-loop topology as a current source is revisited. This circuit topology was already used as a voltage-controlled current source (VCCS) in the 1960s but was left unused when the requirements for higher frequency arose among the applications of electrical bioimpedance (EBI). The aim of the authors is not only limited to show that with the currently available electronic devices it is perfectly viable to use this simple VCCS topology as a working current source for wideband spectroscopy applications of EBI, but also to identify the limitations and the role of each of the circuit components in the most important parameter of a current for wideband applications: the output impedance. The study includes the eventual presence of a stray capacitance and also an original enhancement, driving with current the VCCS. Based on the theoretical analysis and experimental measurements, an accurate model of the output impedance is provided, explaining the role of the main constitutive elements of the circuit in the source's output impedance. Using the topologies presented in this work and the proposed model, any electronic designer can easily implement a simple and efficient current source for wideband EBI spectroscopy applications, e.g. in this study, values above 150 kΩ at 1 MHz have been obtained, which to the knowledge of the authors are the largest values experimentally measured and reported for a current source in EBI at this frequency.

  20. Power Controllability of Three-phase Converter with Unbalanced AC Source

    DEFF Research Database (Denmark)

    Ma, Ke; Chen, Wenjie; Liserre, Marco

    2015-01-01

    Three-phase DC-AC power converters suffer from power oscillation and overcurrent problems in case of unbalanced AC source voltage that can be caused by grid/generator faults. Existing solutions to handle these problems are properly selecting and controlling the positive and negative sequence...... currents. In this work a new series of control strategies which utilize the zerosequence components are proposed to enhance the power control ability under this adverse condition. It is concluded that by introducing proper zero sequence current controls and corresponding circuit configurations, the power...... converter can enable more flexible control targets, achieving better performances in the delivered power and load current when suffering from unbalanced AC voltage....

  1. The Design Performance of the Integrated Spallation Neutron Source Vacuum Control System

    CERN Document Server

    Tang, Johnny Y; Ladd, Peter; Williams, Derrick

    2005-01-01

    The Spallation Neutron Source vacuum control systems have been developed within a collaboration of Lawrence Berkeley National Laboratory(LBNL), Los Alamos National Laboratory(LANL), Thomas Jefferson National Accelerator Facility(TJNAF), and Brookhaven National Laboratory(BNL). Each participating lab is responsible for a different section of the machine. Although a great deal of effort has been made to standardize vacuum instrumentation components and the global control system interfaces, the varied requirements of the different sections of the machine made horizontal integration of the individual vacuum control systems both interesting and challenging. To support commissioning, the SNS control system team and the vacuum group developed a set of test strategies and the interlock schemes that allowed horizontal vacuum system integration to be effectively achieved. The design of the vacuum control interlock scheme developed will be presented together with the results of performance measurements made on these sch...

  2. Optimal and Adaptive Virtual Unidirectional Sound Source in Active Noise Control

    Directory of Open Access Journals (Sweden)

    Dariusz Bismor

    2008-01-01

    Full Text Available One of the problems concerned with active noise control is the existence of acoustical feedback between the control value (“active” loudspeaker output and the reference signal. Various experiments show that such feedback can seriously decrease effects of attenuation or even make the whole ANC system unstable. This paper presents a detailed analysis of one of possible approaches allowing to deal with acoustical feedback, namely, virtual unidirectional sound source. With this method, two loudspeakers are used together with control algorithm assuring that the combined behaviour of the pair makes virtual propagation of sound only in one direction. Two different designs are presented for the application of active noise control in an acoustic duct: analytical (leading to fixed controller and adaptive. The algorithm effectiveness in simulations and real experiments for both solutions is showed, discussed, and compared.

  3. Simulation of neutron multiplicity measurements using Geant4. Open source software for nuclear arms control

    Energy Technology Data Exchange (ETDEWEB)

    Kuett, Moritz

    2016-07-07

    Nuclear arms control, including nuclear safeguards and verification technologies for nuclear disarmament typically use software as part of many different technological applications. This thesis proposes to use three open source criteria for such software, allowing users and developers to have free access to a program, have access to the full source code and be able to publish modifications for the program. This proposition is presented and analyzed in detail, together with the description of the development of ''Open Neutron Multiplicity Simulation'', an open source software tool to simulate neutron multiplicity measurements. The description includes physical background of the method, details of the developed program and a comprehensive set of validation calculations.

  4. Control and design of full-bridge three-level converter for renewable energy sources

    DEFF Research Database (Denmark)

    Yao, Zhilei; Xu, Jing; Guerrero, Josep M.

    2015-01-01

    Output voltage of renewable energy sources, such as fuel cell and PV cell, is often low and varies widely with load and environmental conditions. Therefore, the high step-up DC-DC converter is needed between renewable energy sources and the grid-connected inverter. However, voltage stress...... of rectifier diodes is high and filter is large in traditional voltage-source converters in a wide input-voltage range. In order to solve the aforementioned problems, a full-bridge (FB) three-level (TL) converter is proposed. It can operate at both two-level and three-level modes, so it is suitable for wide...... input-voltage range application. Compared with FB converter, voltage stress of rectifier diodes and the filter can be reduced. Operating principle and control strategy of the proposed converter are illustrated. Design guidelines and example are given. Simulation results of a 1-kW FB TL converter verify...

  5. Tungsten transport and sources control in JET ITER-like wall H-mode plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Fedorczak, N., E-mail: nicolas.fedorczak@cea.fr [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Monier-Garbet, P. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Pütterich, T. [MPI für Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, 85748 Garching (Germany); Brezinsek, S. [Institute of Energy and Climate Research, Forschungszentrum Jlich, Assoc EURATOM-FZJ, Jlich (Germany); Devynck, P.; Dumont, R.; Goniche, M.; Joffrin, E. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Lerche, E. [Association EURATOM-Belgian State, LPP-ERM-KMS, TEC partner, Brussels (Belgium); Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Lipschultz, B. [York Plasma Institute, University of York, Heslington, York YO10 5DD (United Kingdom); Luna, E. de la [Laboratorio Nacional de Fusin, Asociacin EURATOM/CIEMAT, 28040 Madrid (Spain); Maddison, G. [Culham Centre for Fusion Energy, EURATOM-CCFE Association, Abingdon (United Kingdom); Maggi, C. [MPI für Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, 85748 Garching (Germany); Matthews, G. [Culham Centre for Fusion Energy, EURATOM-CCFE Association, Abingdon (United Kingdom); Nunes, I. [Istituto de plasmas e fusao nuclear, Lisboa (Portugal); Rimini, F. [Culham Centre for Fusion Energy, EURATOM-CCFE Association, Abingdon (United Kingdom); Solano, E.R. [Laboratorio Nacional de Fusin, Asociacin EURATOM/CIEMAT, 28040 Madrid (Spain); Tamain, P. [CEA, IRFM, F-13108 Saint-Paul-Lez-Durance (France); Tsalas, M. [Association EURATOM-Hellenic Republic, NCSR Demokritos 153 10, Attica (Greece); Vries, P. de [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)

    2015-08-15

    A set of discharges performed with the JET ITER-like wall is investigated with respect to control capabilities on tungsten sources and transport. In attached divertor regimes, increasing fueling by gas puff results in higher divertor recycling ion flux, lower divertor tungsten source, higher ELM frequency and lower core plasma radiation, dominated by tungsten ions. Both pedestal flushing by ELMs and divertor screening (including redeposition) are possibly responsible. For specific scenarios, kicks in plasma vertical position can be employed to increase the ELM frequency, which results in slightly lower core radiation. The application of ion cyclotron radio frequency heating at the very center of the plasma is efficient to increase the core electron temperature gradient and flatten electron density profile, resulting in a significantly lower central tungsten peaking. Beryllium evaporation in the main chamber did not reduce the local divertor tungsten source whereas core radiation was reduced by approximately 50%.

  6. Power angle control of grid-connected voltage source converter in a wind energy application

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Jan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Electric Power Engineering

    1995-12-31

    In this thesis, the connection of a voltage source converter to the grid in a wind energy application is examined. The possibility of using a cheap control system without grid current measurements, is investigated. The control method is based on controlling the voltage angle of the inverter, which governs the active power flow. The highest frequency of the power variation, coming from wind turbine, is approx. 5 Hz. Since the proposed control method easily can handle such power variations it is very well suited for wind turbine applications. The characteristics of the system depend on the DC-link capacitor, the grid filter inductance and resistance. Large values of the resistance damp the system well but increase the energy losses. A high inductance leads to a reduced harmonic level on the grid but makes the system slower. By using feed-forward of the generator/rectifier current signal, the performance is increased compared to an ordinary PI-control. Combining the Linear Quadratic (LQ) control method with Kalman filtered input signals, a robust control method with a good performance is obtained. The LQ controller controls both the phase displacement angle and the modulation index, resulting in higher bandwidth, and the typical power angle resonance at the grid frequency disappears. 22 refs, 109 figs, 14 tabs

  7. Modeling the effects of integrating larval habitat source reduction and insecticide treated nets for malaria control.

    Directory of Open Access Journals (Sweden)

    Laith Yakob

    Full Text Available Integrated vector management for malaria control has received a lot of recent interest. Attacking multiple points in the transmission cycle is hoped to act synergistically and improve upon current single-tool interventions based on the use of insecticide-treated bed nets (ITNs. In the present study, we theoretically examined the application of larval habitat source reduction with ITNs in reducing malaria transmission. We selected this type of environmental management to complement ITNs because of a potential secondary mode of action that both control strategies share. In addition to increasing vector mortality, ITNs reduce the rate at which female mosquitoes locate human hosts for blood feeding, thereby extending their gonotrophic cycle. Similarly, while reducing adult vector emergence and abundance, source reduction of larval habitats may prolong the cycle duration by extending delays in locating oviposition sites. We found, however, that source reduction of larval habitats only operates through this secondary mode of action when habitat density is below a critical threshold. Hence, we illustrate how this strategy becomes increasingly effective when larval habitats are limited. We also demonstrate that habitat source reduction is better suited to human populations of higher density and in the presence of insecticide resistance or when the insecticidal properties of ITNs are depleted.

  8. The accuracy of webcams in 2D motion analysis: sources of error and their control

    Energy Technology Data Exchange (ETDEWEB)

    Page, A; Candelas, P; Belmar, F [Departamento de Fisica Aplicada, Universidad Politecnica de Valencia, Valencia (Spain); Moreno, R [Instituto de Biomecanica de Valencia, Valencia (Spain)], E-mail: alvaro.page@ibv.upv.es

    2008-07-15

    In this paper, we show the potential of webcams as precision measuring instruments in a physics laboratory. Various sources of error appearing in 2D coordinate measurements using low-cost commercial webcams are discussed, quantifying their impact on accuracy and precision, and simple procedures to control these sources of error are presented. Finally, an experiment with controlled movement is performed to experimentally measure the errors described above and to assess the effectiveness of the proposed corrective measures. It will be shown that when these aspects are considered, it is possible to obtain errors lower than 0.1%. This level of accuracy demonstrates that webcams should be considered as very precise and accurate measuring instruments at a remarkably low cost.

  9. Exploring the Earth's crust: history and results of controlled-source seismology

    Science.gov (United States)

    Prodehl, Claus; Mooney, Walter D.

    2012-01-01

    This volume contains a comprehensive, worldwide history of seismological studies of the Earth’s crust using controlled sources from 1850 to 2005. Essentially all major seismic projects on land and the most important oceanic projects are covered. The time period 1850 to 1939 is presented as a general synthesis, and from 1940 onward the history and results are presented in separate chapters for each decade, with the material organized by geographical region. Each chapter highlights the major advances achieved during that decade in terms of data acquisition, processing technology, and interpretation methods. For all major seismic projects, the authors provide specific details on field observations, interpreted crustal cross sections, and key references. They conclude with global and continental-scale maps of all field measurements and interpreted Moho contours. An accompanying DVD contains important out-of-print publications and an extensive collection of controlled-source data, location maps, and crustal cross sections.

  10. Quantitative evaluation of emission control of primary and secondary organic aerosol sources during Beijing 2008 Olympics

    Science.gov (United States)

    Guo, S.; Hu, M.; Guo, Q.; Zhang, X.; Schauer, J. J.; Zhang, R.

    2012-12-01

    To explore the primary and secondary sources of fine organic particles after the aggressive implementation of air pollution controls during 2008 Beijing Olympic Games, 12-h PM2.5 concentrations were measured at one urban and one upwind rural site during the CAREBeijing-2008 (Campaigns of Air quality REsearch in Beijing and surrounding region) summer field campaign. The PM2.5 concentrations were 72.5±43.6μg m3 and 64.3±36.2μg m-3 at the urban site and rural site, respectively, which were the lowest in recent years due to the implementation of drastic control measures and favorable weather conditions. Five primary and four secondary fine organic particle sources were quantified using a CMB (chemical mass balance) model and tracer-yield method. Compared with previous studies in Beijing, the contribution of vehicle emission increased, with diesel engines contributing 16.2±5.9% and 14.5±4.1% to the total organic carbon (OC) concentrations and gasoline vehicles accounting for 10.3±8.7% and 7.9±6.2% of the OC concentrations at two sites. Due to the implementation of emission control measures, the OC concentrations from important primary sources have been reduced, and secondary formation has become an important contributor to fine organic aerosols. Compared with the non-controlled period, primary vehicle contributions were reduced by 30% and 24% in the urban and regional area, and reductions in the contribution from coal combustion were 57% and 7%, respectively. These results demonstrate the emission control measures significantly alleviated the primary organic particle pollution in and around Beijing. However, the control effectiveness of secondary organic particles was not significant.

  11. TOC changes in the process of thermal evolution of source rock and its controls

    Institute of Scientific and Technical Information of China (English)

    ZHONG; Ningning; LU; Shuangfang; HUANG; Zhilong; ZHANG; Y

    2004-01-01

    Through geological observation, simulation in laboratory and numerical modeling, the factors that control the changes in total organic content (TOC) of source rock have been studied. When the formula DTOC=(TOC0-TOC)/TOC0 (original organic carbon content in the rock) is used to measure the TOC (total organic carbon content) changes in the source rock through geological time, the degrees and directions of such changes are determined by losses and relative amounts both of organic and inorganic matter in the source rock. The DTOC equation, which is used to calculate the loss rate in the process of maturation for the source rock, is therefore obtained by analyzing the mass balance relations. For a certain type of source rock with a certain maturation history, the changes of its TOC respond only to the rates of hydrocarbon generation and expulsion. In actual cases of geological entities, DTOC generally ranges from -0.05 to 0.2, while the calculated reconversion coefficient (k) for organic carbon content remains between 0.90 and 1.25. Only in an ideal situation where there are extremely high rates of hydrocarbon generation and expulsion can the DTOC value experience significant changes, with k reaching up to 2.5. It is concluded, therefore, that the criterion for carbonates source rock assessment, based on reconverting the TOC to the value of its original state, may have overestimated the course of the "carbon-reduction", which is likely in many cases to make a poor source rock sound better.

  12. Modelling and control of cholera on networks with a common water source.

    Science.gov (United States)

    Shuai, Zhisheng; van den Driessche, P

    2015-01-01

    A mathematical model is formulated for the transmission and spread of cholera in a heterogeneous host population that consists of several patches of homogeneous host populations sharing a common water source. The basic reproduction number ℛ0 is derived and shown to determine whether or not cholera dies out. Explicit formulas are derived for target/type reproduction numbers that measure the control strategies required to eradicate cholera from all patches.

  13. The development of control processes supporting source memory discrimination as revealed by event-related potentials.

    Science.gov (United States)

    de Chastelaine, Marianne; Friedman, David; Cycowicz, Yael M

    2007-08-01

    Improvement in source memory performance throughout childhood is thought to be mediated by the development of executive control. As postretrieval control processes may be better time-locked to the recognition response rather than the retrieval cue, the development of processes underlying source memory was investigated with both stimulus- and response-locked event-related potentials (ERPs). These were recorded in children, adolescents, and adults during a recognition memory exclusion task. Green- and red-outlined pictures were studied, but were tested in black outline. The test requirement was to endorse old items shown in one study color ("targets") and to reject new items along with old items shown in the alternative study color ("nontargets"). Source memory improved with age. All age groups retrieved target and nontarget memories as reflected by reliable parietal episodic memory (EM) effects, a stimulus-locked ERP correlate of recollection. Response-locked ERPs to targets and nontargets diverged in all groups prior to the response, although this occurred at an increasingly earlier time point with age. We suggest these findings reflect the implementation of attentional control mechanisms to enhance target memories and facilitate response selection with the greatest and least success, respectively, in adults and children. In adults only, response-locked ERPs revealed an early-onsetting parietal negativity for nontargets, but not for targets. This was suggested to reflect adults' ability to consistently inhibit prepotent target responses for nontargets. The findings support the notion that the development of source memory relies on the maturation of control processes that serve to enhance accurate selection of task-relevant memories.

  14. Modified Motivation System as the Information Source for Personal Controlling. Case of the Hotel

    OpenAIRE

    Małgorzata Sztorc

    2008-01-01

    The purpose of the article is to analysis of employee system incentive hotel there be source of information for personal controlling. New incentive system fitted look to suggest for notes entered by employee. It pay attention in article, that there is sole form of motivating of forceful employee proprietary form financial motivator. Proper system of motivation effects boost of efficiency of staff aiming at achievement in firm purposes indicated appointee. Besides, it shows revolt of working g...

  15. Mount St. Helens: Controlled-source audio-frequency magnetotelluric (CSAMT) data and inversions

    Science.gov (United States)

    Wynn, Jeff; Pierce, Herbert A.

    2015-01-01

    This report describes a series of geoelectrical soundings carried out on and near Mount St. Helens volcano, Washington, in 2010–2011. These soundings used a controlled-source audio-frequency magnetotelluric (CSAMT) approach (Zonge and Hughes, 1991; Simpson and Bahr, 2005). We chose CSAMT for logistical reasons: It can be deployed by helicopter, has an effective depth of penetration of as much as 1 kilometer, and requires less wire than a Schlumberger sounding.

  16. Power factor controller used as DC-DC converter for photovoltaic sources

    Energy Technology Data Exchange (ETDEWEB)

    Mukerjee, A.K.; Dasgupta, Nivedita [Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016 (India)

    2008-06-15

    An active power factor controller (PFC) integrated circuit, normally used in AC circuits, has been used for DC-to-DC boost conversion with a stable output voltage for a variable DC input voltage as obtained from photovoltaic (PV) sources. The circuit described here uses a power factor controller MC 34262 to give approximately 400 V{sub DC} output for an input variation from 90 to 280 V{sub DC}. The maximum efficiency achieved was 98% at 450 W. Comparisons between AC and DC operations have been made. (author)

  17. Single Phase Current-Source Active Rectifier for Traction: Control System Design and Practical Problems

    Directory of Open Access Journals (Sweden)

    Jan Michalik

    2006-01-01

    Full Text Available This research has been motivated by industrial demand for single phase current-source active rectifier dedicated for reconstruction of older types of dc machine locomotives. This paper presents converters control structure design and simulations. The proposed converter control is based on the mathematical model and due to possible interaction with railway signaling and required low switching frequency employs synchronous PWM. The simulation results are verified by experimental tests performed on designed laboratory prototype of power of 7kVA

  18. Stability analysis and design of the improved droop controller on a voltage source inverter

    DEFF Research Database (Denmark)

    Calabria, Mauro; Schumacher, Walter; Guerrero, Josep M.;

    2015-01-01

    This paper studies the dynamics of a droop-controlled voltage source inverter connected to a stiff grid and addresses the use of the improved droop controller in order to enhance the dynamic behavior of the system. The small-signal stability of the inverter is studied in depth considering...... variations on its droop parameters, providing a general understanding on the functioning of such system. Finally, three methods to tune the dynamic droop gain are introduced and compared, providing analytical, simulation, and experimental results....

  19. Precision control of inverter welding power sources by using T-S fuzzy systems

    Institute of Scientific and Technical Information of China (English)

    Zhou Yiqing; Huang Shisheng; Zhang Hongbing; Wang Zhenmin; Xie Shengmian

    2007-01-01

    The functional relationship of approximation accuracy and number of fuzzy sets is used to find the rational balance point between the control accuracy and the control cost of fuzzy systems. This approach efficiently eliminates the drawback of rapid control cost increase caused by blind increase of fuzzy set number in practical engineering. The sufficient conditions for T-S fuzzy systems as universal approximators are derived. A special T-S fuzzy system that satisfied these conditions is analyzed, and the simulation results show that when the number of fuzzy sets is increased moderately, the model parameters' training epochs can be effectually decreased while the model accuracy improved significantly. A practical welding power source controlled by a T-S fuzzy system is developed with satisfactory experimental results.

  20. Optimized Controller Design for a 12-Pulse Voltage Source Converter Based HVDC System

    Science.gov (United States)

    Agarwal, Ruchi; Singh, Sanjeev

    2017-08-01

    The paper proposes an optimized controller design scheme for power quality improvement in 12-pulse voltage source converter based high voltage direct current system. The proposed scheme is hybrid combination of golden section search and successive linear search method. The paper aims at reduction of current sensor and optimization of controller. The voltage and current controller parameters are selected for optimization due to its impact on power quality. The proposed algorithm for controller optimizes the objective function which is composed of current harmonic distortion, power factor, and DC voltage ripples. The detailed designs and modeling of the complete system are discussed and its simulation is carried out in MATLAB-Simulink environment. The obtained results are presented to demonstrate the effectiveness of the proposed scheme under different transient conditions such as load perturbation, non-linear load condition, voltage sag condition, and tapped load fault under one phase open condition at both points-of-common coupling.

  1. The adequacy of current import and export controls on sealed radioactive sources.

    Energy Technology Data Exchange (ETDEWEB)

    Longley, Susan W.; Cochran, John Russell; Price, Laura L. (Beta Corporation, Glendale, AZ); Lipinski, Kendra J.

    2003-10-01

    Millions of sealed radioactive sources (SRSs) are being used for a wide variety of beneficial purposes throughout the world. Security experts are now concerned that these beneficial SRSs could be used in a radiological dispersion device to terrorize and disrupt society. The greatest safety and security threat is from those highly radioactive Category 1 and 2 SRSs. Without adequate controls, it may be relatively easy to legally purchase a Category 1 or 2 SRS on the international market under false pretenses. Additionally, during transfer, SRSs are particularly susceptible to theft since the sources are in a shielded and mobile configuration, transportation routes are predictable, and shipments may not be adequately guarded. To determine if government controls on SRS are adequate, this study was commissioned to review the current SRS import and export controls of six countries. Canada, the Russian Federation, and South Africa were selected as the exporting countries, and Egypt, the Philippines, and the United States were selected as importing countries. A detailed review of the controls in each country is presented. The authors found that Canada and Russia are major exporters, and are exporting highly radioactive SRSs without first determining if the recipient is authorized by the receiving country to own and use the SRSs. Available evidence was used to estimate that on average there are tens to possibly hundreds of intercountry transfers of highly radioactive SRSs each day. Based on these and other findings, this reports recommends stronger controls on the export and import of highly radioactive SRSs.

  2. Controlling Nonpoint Pollution in Virginia’s Urbanizing Areas: An Institutional Perspective.

    Science.gov (United States)

    1986-01-20

    channel, tunnel , conduit, from which pollutants are or may be discharged." The point is that pollution from 33 U.S. C.A, § 1251 (a) (1978). 9 Id at...concrete formwork ). Likewise, a required permanent on-site BMP would be considered part of the overall site development plan. Such costs are absorbed by

  3. Multi-rate control over AWGN channels via analog joint source-channel coding

    KAUST Repository

    Khina, Anatoly

    2017-01-05

    We consider the problem of controlling an unstable plant over an additive white Gaussian noise (AWGN) channel with a transmit power constraint, where the signaling rate of communication is larger than the sampling rate (for generating observations and applying control inputs) of the underlying plant. Such a situation is quite common since sampling is done at a rate that captures the dynamics of the plant and which is often much lower than the rate that can be communicated. This setting offers the opportunity of improving the system performance by employing multiple channel uses to convey a single message (output plant observation or control input). Common ways of doing so are through either repeating the message, or by quantizing it to a number of bits and then transmitting a channel coded version of the bits whose length is commensurate with the number of channel uses per sampled message. We argue that such “separated source and channel coding” can be suboptimal and propose to perform joint source-channel coding. Since the block length is short we obviate the need to go to the digital domain altogether and instead consider analog joint source-channel coding. For the case where the communication signaling rate is twice the sampling rate, we employ the Archimedean bi-spiral-based Shannon-Kotel\\'nikov analog maps to show significant improvement in stability margins and linear-quadratic Gaussian (LQG) costs over simple schemes that employ repetition.

  4. RIO EPICS device support application case study on an ion source control system (ISHP)

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Diego [UPM – Universidad Politécnica de Madrid, Madrid (Spain); Ruiz, Mariano, E-mail: mariano.ruiz@upm.es [UPM – Universidad Politécnica de Madrid, Madrid (Spain); Eguiraun, Mikel [Department of Electricity and Electronic, Faculty of Science and Technology, University of Basque Country, Bilbao (Spain); Arredondo, Iñigo [ESS Bilbao Consortium, Zamudio (Spain); Badillo, Inari; Jugo, Josu [Department of Electricity and Electronic, Faculty of Science and Technology, University of Basque Country, Bilbao (Spain); Vega, Jesús; Castro, Rodrigo [Asociación EURATOM/CIEMAT, Madrid (Spain)

    2015-10-15

    Highlights: • A use case example of RIO/FlexRIO design methodology is described. • Ion source device is controlled and monitored by means EPICS IOCs. • NIRIO EPICS device support demonstrates that is able to manage RIO devices. • Easy and fast deployment is possible using RIO/FlexRIO design methodology using NIRIO-EDS. • RIO/FlexRIO technology and EPICS are a good combination for support large scale experiments in fusion environments. - Abstract: Experimental Physics and Industrial Control System (EPICS) is a software tool that during last years has become relevant as a main framework to deploy distributed control systems in large scientific environments. At the moment, ESS Bilbao uses this middleware to perform the control of their Ion Source Hydrogen Positive (ISHP) project. The implementation of the control system was based on: PXI Real Time controllers using the LabVIEW-RT and LabVIEW-EPICS tools; and RIO devices based on Field-Programmable Gate Array (FPGA) technology. Intended to provide a full compliant EPICS IOCs for RIO devices and to avoid additional efforts on the system maintainability, a migration of the current system to a derivative Red Hat Linux (CentOS) environment has been conducted. This paper presents a real application case study for using the NIRIO EPICS device support (NIRIO-EDS) to give support to the ISHP. Although RIO FPGA configurations are particular solutions for ISHP performance, the NIRIO-EDS has permitted the control and monitoring of devices by applying a well-defined design methodology into the previous FPGA configuration for RIO/FlexRIO devices. This methodology has permitted a fast and easy deployment for the new robust, scalable and maintainable software to support RIO devices into the ISHP control architecture.

  5. New energy ramping control system in the Pohang Light Source Storage Ring

    CERN Document Server

    Kim, E S; Seo, J H; Nam, S H

    2003-01-01

    A new energy ramping control system is developed to increase electron beam energy from 2.0 GeV to 2.5 GeV in the Pohang Light Source storage ring. The control system shows faster energy ramping and more stable beam characteristics than the previous energy ramping control system that consists of an operator interface workstation, subsystem control computer and machine interface units. The previous system controls current settings of the magnet power supplies in multiple steps with different energy increment rate during the energy ramping. In order to improve synchronization of the magnet power supply systems and beam stabilities during the energy ramping, we developed the energy ramping controller hardware that is controlled using a network of optical fibers. Thus, the new ramping system is able to control more synchronously the magnet power supplies with a constant energy increment rate during the energy ramping. With this reliable synchronization, it is also possible to perform the energy de-ramping step fro...

  6. Top-Down Control of Visual Alpha Oscillations: Sources of Control Signals and Their Mechanisms of Action.

    Science.gov (United States)

    Wang, Chao; Rajagovindan, Rajasimhan; Han, Sahng-Min; Ding, Mingzhou

    2016-01-01

    Alpha oscillations (8-12 Hz) are thought to inversely correlate with cortical excitability. Goal-oriented modulation of alpha has been studied extensively. In visual spatial attention, alpha over the region of visual cortex corresponding to the attended location decreases, signifying increased excitability to facilitate the processing of impending stimuli. In contrast, in retention of verbal working memory, alpha over visual cortex increases, signifying decreased excitability to gate out stimulus input to protect the information held online from sensory interference. According to the prevailing model, this goal-oriented biasing of sensory cortex is effected by top-down control signals from frontal and parietal cortices. The present study tests and substantiates this hypothesis by (a) identifying the signals that mediate the top-down biasing influence, (b) examining whether the cortical areas issuing these signals are task-specific or task-independent, and (c) establishing the possible mechanism of the biasing action. High-density human EEG data were recorded in two experimental paradigms: a trial-by-trial cued visual spatial attention task and a modified Sternberg working memory task. Applying Granger causality to both sensor-level and source-level data we report the following findings. In covert visual spatial attention, the regions exerting top-down control over visual activity are lateralized to the right hemisphere, with the dipoles located at the right frontal eye field (FEF) and the right inferior frontal gyrus (IFG) being the main sources of top-down influences. During retention of verbal working memory, the regions exerting top-down control over visual activity are lateralized to the left hemisphere, with the dipoles located at the left middle frontal gyrus (MFG) being the main source of top-down influences. In both experiments, top-down influences are mediated by alpha oscillations, and the biasing effect is likely achieved via an inhibition

  7. Diquat associated with copper sources for algae control: Efficacy and ecotoxicology.

    Science.gov (United States)

    Garlich, Nathalia; Da Cruz, Claudinei; Da Silva, Adilson F; Carraschi, Silvia P; Malaspina, Igor C; Pitelli, Robinson A; Bianco, Silvano

    2016-01-01

    The aims of this research were to evaluate the efficacy of copper oxychloride (CuCl2.3Cu(OH)2), copper hydroxide (Cu(OH)2) and diquat (1.1'-ethylene-2.2'-bipyridyldiylium dibromide), isolated and in association with 0.1% of both copper sources, in the control of the unicellular algae Ankistrodesmus gracilis and the filamentous algae Pithophora kewesis, and to determine the acute toxicity of the tested chemicals in Hyphressobrycon eques, Pomacea canaliculata, Lemna minor and Azolla caroliniana. The efficacy was estimated by the methods of chlorophyll a and pheophytin a readings, changed into growth inhibition percentage. Both algae were exposed to the following concentrations: 0.2; 0.4; 0.8; 1.2 mg L(-1) of diquat and its association with the copper sources; and 0.1; 0.3; 0.5; 0.7; 1.0 and 1.5 mg L(-1) in the isolated applications of copper hydroxide and copper oxychloride. An untreated control was kept. The acute toxicity was estimatedby 50% lethal concentration (LC50). The copper sources were effective for A. gracilis control, at rates as high as 0.1 mg L(-1) (>95% efficacy). Isolated diquat and its association with copper hydroxide were both effective at rates as high as 0.4 mg L(-1), with 95 and 88% control efficacy, respectively. The copper oxychloride was effective at 0.2 mg L(-1), with 93% efficacy. None of the tested chemicals and associations was effective on P. kewesis control. The most sensitive non target organism to the tested chemicals was L. minor; the less sensitive was H. eques.

  8. Quantitative evaluation of emission controls on primary and secondary organic aerosol sources during Beijing 2008 Olympics

    Directory of Open Access Journals (Sweden)

    S. Guo

    2013-08-01

    Full Text Available To assess the primary and secondary sources of fine organic aerosols after the aggressive implementation of air pollution controls during the 2008 Beijing Olympic Games, 12 h PM2.5 values were measured at an urban site at Peking University (PKU and an upwind rural site at Yufa during the CAREBEIJING-2008 (Campaigns of Air quality REsearch in BEIJING and surrounding region summer field campaign. The average PM2.5 concentrations were 72.5 ± 43.6 μg m−3 and 64.3 ± 36.2 μg m−3 (average ± standard deviation, below as the same at PKU and Yufa, respectively, showing the lowest concentrations in recent years. Combining the results from a CMB (chemical mass balance model and secondary organic aerosol (SOA tracer-yield model, five primary and four secondary fine organic aerosol sources were compared with the results from previous studies in Beijing. The relative contribution of mobile sources to PM2.5 concentrations was increased in 2008, with diesel engines contributing 16.2 ± 5.9% and 14.5 ± 4.1% and gasoline vehicles contributing 10.3 ± 8.7% and 7.9 ± 6.2% to organic carbon (OC at PKU and Yufa, respectively. Due to the implementation of emission controls, the absolute OC concentrations from primary sources were reduced during the Olympics, and the contributions from secondary formation of OC represented a larger relative source of fine organic aerosols. Compared with the non-controlled period prior to the Olympics, primary vehicle contributions were reduced by 30% at the urban site and 24% at the rural site. The reductions in coal combustion contributions were 57% at PKU and 7% at Yufa. Our results demonstrate that the emission control measures implemented in 2008 significantly alleviated the primary organic particle pollution in and around Beijing. However, additional studies are needed to provide a more comprehensive assessment of the emission control effectiveness on SOA formation.

  9. Quantitative evaluation of emission controls on primary and secondary organic aerosol sources during Beijing 2008 Olympics

    Science.gov (United States)

    Guo, S.; Hu, M.; Guo, Q.; Zhang, X.; Schauer, J. J.; Zhang, R.

    2013-08-01

    To assess the primary and secondary sources of fine organic aerosols after the aggressive implementation of air pollution controls during the 2008 Beijing Olympic Games, 12 h PM2.5 values were measured at an urban site at Peking University (PKU) and an upwind rural site at Yufa during the CAREBEIJING-2008 (Campaigns of Air quality REsearch in BEIJING and surrounding region) summer field campaign. The average PM2.5 concentrations were 72.5 ± 43.6 μg m-3 and 64.3 ± 36.2 μg m-3 (average ± standard deviation, below as the same) at PKU and Yufa, respectively, showing the lowest concentrations in recent years. Combining the results from a CMB (chemical mass balance) model and secondary organic aerosol (SOA) tracer-yield model, five primary and four secondary fine organic aerosol sources were compared with the results from previous studies in Beijing. The relative contribution of mobile sources to PM2.5 concentrations was increased in 2008, with diesel engines contributing 16.2 ± 5.9% and 14.5 ± 4.1% and gasoline vehicles contributing 10.3 ± 8.7% and 7.9 ± 6.2% to organic carbon (OC) at PKU and Yufa, respectively. Due to the implementation of emission controls, the absolute OC concentrations from primary sources were reduced during the Olympics, and the contributions from secondary formation of OC represented a larger relative source of fine organic aerosols. Compared with the non-controlled period prior to the Olympics, primary vehicle contributions were reduced by 30% at the urban site and 24% at the rural site. The reductions in coal combustion contributions were 57% at PKU and 7% at Yufa. Our results demonstrate that the emission control measures implemented in 2008 significantly alleviated the primary organic particle pollution in and around Beijing. However, additional studies are needed to provide a more comprehensive assessment of the emission control effectiveness on SOA formation.

  10. Satellite-based Dust Source Identification over North Africa: Diurnal Cycle, Meteorological Controls, and Interannual Variability

    Science.gov (United States)

    Schepanski, Kerstin; Tegen, Ina; Macke, Andreas

    2010-05-01

    frequencies of local dust source activations (DSAF). Dust emission is mainly controlled by the occurrence of strong surface wind speeds and surface conditions like vegetation cover which may differ for individual years depending on the climatic conditions. The role of interannualy changing wind and precipitation pattern for DSAF variability is investigated.

  11. Nonlinear control of voltage source converters in AC-DC power system.

    Science.gov (United States)

    Dash, P K; Nayak, N

    2014-07-01

    This paper presents the design of a robust nonlinear controller for a parallel AC-DC power system using a Lyapunov function-based sliding mode control (LYPSMC) strategy. The inputs for the proposed control scheme are the DC voltage and reactive power errors at the converter station and the active and reactive power errors at the inverter station of the voltage-source converter-based high voltage direct current transmission (VSC-HVDC) link. The stability and robust tracking of the system parameters are ensured by applying the Lyapunov direct method. Also the gains of the sliding mode control (SMC) are made adaptive using the stability conditions of the Lyapunov function. The proposed control strategy offers invariant stability to a class of systems having modeling uncertainties due to parameter changes and exogenous inputs. Comprehensive computer simulations are carried out to verify the proposed control scheme under several system disturbances like changes in short-circuit ratio, converter parametric changes, and faults on the converter and inverter buses for single generating system connected to the power grid in a single machine infinite-bus AC-DC network and also for a 3-machine two-area power system. Furthermore, a second order super twisting sliding mode control scheme has been presented in this paper that provides a higher degree of nonlinearity than the LYPSMC and damps faster the converter and inverter voltage and power oscillations.

  12. Spatial variation and source apportionment of water pollution in Qiantang River (China) using statistical techniques.

    Science.gov (United States)

    Huang, Fang; Wang, Xiaoquan; Lou, Liping; Zhou, Zhiqing; Wu, Jiaping

    2010-03-01

    Understanding the spatial distribution and apportioning the sources of water pollution are important in the study and efficient management of water resources. In this work, we considered data for 13 water quality variables collected during the year 2004 at 46 monitoring sites along the Qiantang River (China). Fuzzy comprehensive analysis categorized the data into three major pollution zones (low, moderate, and high) based on national quality standards for surface waters, China. Most sites classified as "low pollution zones" (LP) occurred in the main river channel, whereas those classified as "moderate and high pollution zones" (MP and HP, respectively) occurred in the tributaries. Factor analysis identified two potential pollution sources that explained 67% of the total variance in LP, two potential pollution sources that explained 73% of the total variance in MP, and three potential pollution sources that explained 80% of the total variance in HP. UNMIX was used to estimate contributions from identified pollution sources to each water quality variable and each monitoring site. Most water quality variables were influenced primarily by pollution due to industrial wastewater, agricultural activities and urban runoff. In LP, non-point source pollution such as agricultural runoff and urban runoff dominated; in MP and HP, mixed source pollution dominated. The pollution in the small tributaries was more serious than that in the main channel. These results provide information for developing better pollution control strategies for the Qiantang River.

  13. A Distributed Monitoring and Control System for the Laser Ion Source RILIS at CERN-ISOLDE

    CERN Document Server

    AUTHOR|(SzGeCERN)715185; Richter, Detlef; Wendt, Klaus

    In this work, the implementation of the LabVIEW-based RILIS Equipment Acquisition and Control Toolset (REACT) software framework is documented, revised, and further developed to accomplish remotely operated in-source laser spectroscopy experiments at CERN-ISOLDE. The Resonance Ionization Laser Ion Source (RILIS) is an integral part of the radioactive ion beam user facility ISOLDE at CERN. Its task as an ion source is to ensure high isobaric purity and production efficiency of the ion beams that are generated for the various experimental setups of the facility. Reliable operation requires directing 3 pulsed laser beams, precisely wavelength-tuned and overlapped in time to a precision of 5 nanoseconds, to converge into a 3mm diameter ion source cavity located 25m away in an inaccessible radioactive environment. These stable conditions have to be maintained for up to 7 days at a time per experiment setup. Within recent years, the array of RILIS equipment and its need to interface with other experimental apparatu...

  14. Application of Oligonucleotide Microarrays for Bacterial Source Tracking of Environmental Enterococcus sp. Isolates

    OpenAIRE

    Furey, John S.; Kelley Betts; Indest, Karl J.

    2005-01-01

    In an effort towards adapting new and defensible methods for assessing and managing the risk posed by microbial pollution, we evaluated the utility of oligonucleotide microarrays for bacterial source tracking (BST) of environmental Enterococcus sp. isolates derived from various host sources. Current bacterial source tracking approaches rely on various phenotypic and genotypic methods to identify sources of bacterial contamination resulting from point or non-point pollution. For this study Ent...

  15. Risk of gastric cancer by water source: evidence from the Golestan case-control study.

    Directory of Open Access Journals (Sweden)

    Laura Eichelberger

    Full Text Available Gastric cancer (GC is the world's fifth most common cancer, and the third leading cause of cancer-related death. Over 70% of incident cases and deaths occur in developing countries. We explored whether disparities in access to improved drinking water sources were associated with GC risk in the Golestan Gastric Cancer Case Control Study.306 cases and 605 controls were matched on age, gender, and place of residence. We conducted unconditional logistic regression to calculate odds ratios (ORs and 95% confidence intervals (CI, adjusted for age, gender, ethnicity, marital status, education, head of household education, place of birth and residence, homeownership, home size, wealth score, vegetable consumption, and H. pylori seropositivity. Fully-adjusted ORs were 0.23 (95% CI: 0.05-1.04 for chlorinated well water, 4.58 (95% CI: 2.07-10.16 for unchlorinated well water, 4.26 (95% CI: 1.81-10.04 for surface water, 1.11 (95% CI: 0.61-2.03 for water from cisterns, and 1.79 (95% CI: 1.20-2.69 for all unpiped sources, compared to in-home piped water. Comparing unchlorinated water to chlorinated water, we found over a two-fold increased GC risk (OR 2.37, 95% CI: 1.56-3.61.Unpiped and unchlorinated drinking water sources, particularly wells and surface water, were significantly associated with the risk of GC.

  16. Integrated fuzzy-PI controlled current source converter based D-STATCOM

    Directory of Open Access Journals (Sweden)

    M. Deben Singh

    2016-12-01

    Full Text Available The distribution static synchronous compensator (D-STATCOM is a shunt-connected current injection custom power (CP device that can be used for improving quality and reliability of the power supplied to electric consumers under dynamic conditions of the distribution system. The CP devices such as dynamic voltage restorer and unified power quality conditioner including D-STATCOM are mostly designed and implemented using voltage source converter topology. The performance of D-STATCOM can be improved, if it is realized by using a current source converter topology which can generate a controllable current directly at its output terminals. Although the current source converter (CSC topology offers many promising advantageous features, not much research publications with CSC-based approach in the field of CP devices has been reported over the last one decade. This paper presents a novel method of realizing a D-STATCOM using CSC topology with an integrated fuzzy-PI controller for not only mitigating voltage sag but also capable of maintaining improved DC-link voltage profile. The model has been simulated in the MATLAB/SIMULINK environment. The simulation results under steady state and dynamic load perturbation provide excellent output characteristics that support the validity of the proposed model.

  17. Standards and the design of the Advanced Photon Source control system

    Science.gov (United States)

    McDowell, W. P.; Knott, M. J.; Lenkszus, F. R.; Kraimer, M. R.; Daly, R. T.; Arnold, N. D.; Anderson, M. D.; Anderson, J. B.; Zieman, R. C.; Cha, Ben-Chin K.

    The Advanced Photon Source (APS), now under construction at Argonne National Laboratory is a 7 GeV positron storage ring dedicated to research facilities using synchrotron radiation. This ring, along with its injection accelerators is to be controlled and monitored with a single, flexible, and expandable control system. In the conceptual stage the control system design group faced the challenges that face all control system designers: to force the machine designers to quantify and codify the system requirements, to protect the investment in hardware and software from rapid obsolescence, and to find methods of quickly incorporating new generations of equipment and replace of obsolete equipment without disrupting the exiting system. To solve these and related problems, the APS control system group made an early resolution to use standards in the design of the system. This paper will cover the present status of the APS control system as well as discuss the design decisions which led us to use industrial standards and collaborations with other laboratories whenever possible to develop a control system. It will explain the APS control system and illustrate how the use of standards has allowed APS to design a control system whose implementation addresses these issues. The system will use high performance graphic workstations using an X-Windows Graphical User Interface at the operator interface level. It connects to VME-based microprocessors at the field level using TCP/IP protocols over high performance networks. This strategy assures the flexibility and expansibility of the control system. A defined interface between the system components will allow the system to evolve with the direct addition of future, improved equipment and new capabilities.

  18. Quantifying estimation of "static-shift" distortions with the use of natural and controlled sources.

    Science.gov (United States)

    Zhamaletdinov, Abdulkhai

    2017-04-01

    Static distortions exert the frequency-independent influence on results of electromagnetic soundings as with natural so with controlled sources. They originate from subsurface heterogeneities having sizes smaller than the wavelength of electromagnetic field in the ground. There are several ways to avoid the static distortions. The first one based on the use of measuring lines with lengths exceeding transversal dimensions of subsurface heterogeneities [Berdichevsky, 1968; Zhamaletdinov, 1990]. The second method based on the use of the global magnetovariational sounding (MVS) curve for the parallel displacement of magnetotelluric sounding (MTS) curves [Rokityansky 1971]. The third way is the OCCAM inversion [Constable et al., 1987]. It is based on the use of MVS results for correction of amplitude curves MTS with the use of phase measurements. The fourth, statistical approach is based on the joint analysis of amplitude and phase MTS curves on a sufficiently large array observations [Jones, 1988]. The fifth approach is based on separation of local and regional effects (decomposition methods) [Bahr, 1988, Groom & Bailey, 1989]. All these methods have qualitative character. In this paper we propose a quantitative method, based on the use of soundings with natural and controlled sources made at one point. Below, for example, three expressions are presented for longitudinal electric (1) transversal magnetic (2) and impedance (3) for the grounded electric dipole on the homogeneous half-space in a quasi-stationary (plane-wave) band [Vanyan 1965]. The resistivity of undersurface half-space in the field of controlled source can be defined by electric (1) and magnetic (2) components separately and by their relation (3). But in MTS technique only impedance (3) can be used for that, because the source parameters are unknown. This property of electromagnetic field has been used in the experiment "Kovdor-2015" [Zhamaletdinov et al., 2016]. Frequency soundings were performed at

  19. Low-Level RF Control of Spallation Neutron Source: System and Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Hengjie [ORNL

    2005-01-01

    The low-level RF control system currently commissioned throughout the Spallation Neutron Source (SNS) LINAC evolved from three design iterations over one year intensive research and development. Its digital hardware implementation is efficient, and has succeeded in achieving a minimum latency of less than 150 ns which is the key for accomplishing an all digital feedback control for the full bandwidth. The control bandwidth is analyzed in frequency domain and characterized by testing its transient response. The hardware implementation also includes the provision of a time-shared input channel for a superior phase differential measurement between the cavity field and the reference. A companion co-simulation system for the digital hardware was developed to ensure a reliable long-term supportability. A large effort has also been made in the operation software development for the practical issues such as the process automations, cavity filling, beam loading compensation, and the cavity mechanical resonance suppression.

  20. Improved direct power control of a grid-connected voltage source converter during network unbalance

    Institute of Scientific and Technical Information of China (English)

    Peng ZHOU; Wei ZHANG; Yi-kang HE; Rong ZENG

    2010-01-01

    This paper deals with an improved direct power control(DPC)strategy for the pulse width modulation(PWM)voltage source converter(VSC)under unbalanced grid voltage conditions.In order to provide enhanced control performance for the VSC,the resonant controllers tuned at the double grid frequency are applied in the DPC design to eliminate the power pulsations and dc link voltage ripples produced by the transient unbalanced grid faults.In this way,the output power and dc link voltage of the VSC can be directly regulated without positive and negative sequential decomposition.As a result,and as has been verified by experiment,the proposed method can provide fast dynamic response with easy implementation.

  1. Formaldehyde and acetaldehyde exposure mitigation in US residences: In-home measurements of ventilation control and source control

    Energy Technology Data Exchange (ETDEWEB)

    Hult, Erin L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Willem, Henry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Phillip N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hotchi, Toshifumi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Russell, Marion L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-10-01

    Measurements were taken in new US residences to assess the extent to which ventilation and source control can mitigate formaldehyde exposure. Increasing ventilation consistently lowered indoor formaldehyde concentrations. However, at a reference air exchange rate of 0.35 h-1, increasing ventilation was up to 60% less effective than would be predicted if the emission rate were constant. This is consistent with formaldehyde emission rates decreasing as air concentrations increase, as observed in chamber studies. In contrast, measurements suggest acetaldehyde emission was independent of ventilation rate. To evaluate the effectiveness of source control, formaldehyde concentrations were measured in Leadership in Energy and Environmental Design (LEED) certified/Indoor airPLUS homes constructed with materials certified to have low emission rates of volatile organic compounds (VOC). At a reference air exchange rate of 0.35 h-1, and adjusting for home age, temperature and relative humidity, formaldehyde concentrations in homes built with low-VOC materials were 42% lower on average than in reference new homes with conventional building materials. Without adjustment, concentrations were 27% lower in the low-VOC homes. The mean and standard deviation of formaldehyde concentration were 33 μg m-3 and 22 μg m-3 for low-VOC homes and 45 μg m-3 and 30 μg m-3 for conventional.

  2. Spatial control of processing plasmas in a multicusp plasma source equipped with a movable magnetic filter

    Energy Technology Data Exchange (ETDEWEB)

    Fukumasa, O.; Naitou, H.; Sakiyama, S. (Yamaguchi Univ., Yamaguchi (Japan))

    1991-12-20

    The plasma chemical vapor deposition (p-CVD) method has been used in the preparation of various sorts of thin films such as hydrogenated amorphous silicon films and hydrogenated amorphous carbon films, etc. and the application feasibility of a magnetically filtered multicusp plasma source has been studied. In this paper, it is confirmed that plasma parameters (H {sub 2} - ch {sub 4} or Ar-CH {sub 4} plasmas) are spatially well controlled by using both a movable magnetic filter and a plasma grid. Plasma parameters change sharply across the magnetic filter at any filter position and the whole plasma is divided clearly into the region of source plasma with high-energy electrons and the region of diffused plasma without high-energy electrons. Concerning the role of the magnetic filter which reflects preferentially high-energy electrons, a study is made through computer simulation. 7 refs., 9 figs.

  3. A parallel finite-element method for three-dimensional controlled-source electromagnetic forward modelling

    Science.gov (United States)

    Puzyrev, Vladimir; Koldan, Jelena; de la Puente, Josep; Houzeaux, Guillaume; Vázquez, Mariano; Cela, José María

    2013-05-01

    We present a nodal finite-element method that can be used to compute in parallel highly accurate solutions for 3-D controlled-source electromagnetic forward-modelling problems in anisotropic media. Secondary coupled-potential formulation of Maxwell's equations allows to avoid the singularities introduced by the sources, while completely unstructured tetrahedral meshes and mesh refinement support an accurate representation of geological and bathymetric complexity and improve the solution accuracy. Different complex iterative solvers and an efficient pre-conditioner based on the sparse approximate inverse are used for solving the resulting large sparse linear system of equations. Results are compared with the ones of other researchers to check the accuracy of the method. We demonstrate the performance of the code in large problems with tens and even hundreds of millions of degrees of freedom. Scalability tests on massively parallel computers show that our code is highly scalable.

  4. Theoretical study on active control of sound radiation based on planar sound source

    Institute of Scientific and Technical Information of China (English)

    CHENKe'an; GaryH.Koopmann

    2003-01-01

    Active control of low frequency sound radiation using planar secondary sources is theoretically investigated. The primary sound field originates from a vibrating panel and the planar secondary sources are modeled as simply supported rectangular panels in an infinite baffle. The sound power of the primary and secondary panels is calculated, and then a series of formulae are derived to obtain the optimum reduction in sound power. Finally, active reduction for a number of secondary panel arrangements is examined, it is concluded that when the modal distribution of the secondary panel does coincide with that of the primary panel, one secondary panel is sufficient. Otherwise four secondary panels can guarantee considerable reduction in sound power over entire frequency range of interest.

  5. A source classification framework supporting pollutant source mapping, pollutant release prediction, transport and load forecasting, and source control planning for urban environments

    DEFF Research Database (Denmark)

    Lützhøft, Hans-Christian Holten; Donner, Erica; Wickman, Tonie

    2012-01-01

    Purpose Implementation of current European environmental legislation such as the Water Framework Directive requires access to comprehensive, well-structured pollutant source and release inventories. The aim of this work was to develop a Source Classification Framework (SCF) ideally suited...... in the form of a relational database and incorporates both qualitative and quantitative source classification and release data. The system supports a wide range of pollution monitoring and management applications. The SCF functioned well in the performance test, which also revealed important gaps in priority...

  6. Heavy Metal Control in Domestic Rubbish by Source Screening and Suitability of Nutrient Elements as Turfgrass Medium

    Institute of Scientific and Technical Information of China (English)

    DUO Li-an; ZHAO Shu-lan; GAO Yu-bao

    2005-01-01

    This paper, probing into heavy metal control in domestic rubbish by source screening and nutrient element analysis, revealed the feasibility of source control of heavy metals and the suitability of rubbish as turfgrass medium. Heavy metals in domestic rubbish were controlled by source screening before composting. The study consisted of a control with garden soil. The contents of main mineral elements and heavy metals in rubbish compost and control were determined by the method of ICP-AES. The results showed that heavy metal concentrations in rubbish were lower than those in garden soil, and little difference occurred between rubbish and garden soil in main mineral element concentrations. Based on this, it was concluded that rubbish compost was favorable for using as turfgrass medium and heavy metal control in rubbish by source screening was effective.

  7. Using Adaptive Discrete-Time Gas Supply Control for Long Pulse Arc Discharge of Ion Source on NBI

    Institute of Scientific and Technical Information of China (English)

    SHENG Peng; HU Chundong; SONG Shihua; LIU Sheng; LIU Zhimin

    2008-01-01

    A control model of gas supply system is introduced for ion source and an adaptive discrete-time control algorithm to regulate the hydrogen injection.A real-time feedback control system (RFCS) is designed to control the gas supply for ion source based on the control model and the discrete-time control algorithm.The experimental results have proved that RFCS could regulate the gas supply smoothly,suppress the arc's abrupt over-current at the end of the ion