WorldWideScience

Sample records for nonpoint source critical

  1. 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

  2. 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.

  3. 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.

  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. 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.

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. [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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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...

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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

    . Anticipating changes in sources and transformations will be critical for effectively managing nonpoint pollution and ecosystem services such as drinking water quality and coastal habitat.

  8. 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…

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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...

  2. 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...

  3. 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).

  4. 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).

  5. 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...

  6. 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.

  7. 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”.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.)

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. [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.

  8. 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.

  9. [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.

  10. 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.

  11. 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.)

  12. 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.

  13. [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

  14. 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-...

  15. [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.

  16. 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.

  17. 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..

  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. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

    Information on the actual input of pesticides into the environment is crucial for proper risk assessment and the design of risk reduction measures. The Crespo basin is found within the Balcarce County, located south-east of the Buenos Aires Province. The whole basin has an area of approximately 490 km2 and the river has a length of 65 km. This study focuses on the upper basin of the Crespo stream, covering an area of 226 km2 in which 94.7% of the land is under agricultural production representing a highly productive area, characteristic of the Austral Pampas region. In this study we evaluated the levels of glyphosate and its metabolite aminomethylphosphonic acid (AMPA) in soils; and the non-point source pollution of surface waters, stream sediments and groundwater, over a period of one year. Stream water samples were taken monthly using propylene bottles, from the center of the bridge. If present, sediment samples from the first 5 cm were collected using cylinder samplers. Groundwater samples were taken from windmills or electric pumps from different farms every two months. At the same time, composite soil samples (at 5 cm depth) were taken from an agricultural plot of each farm. Samples were analyzed for detection and quantification of glyphosate and AMPA using ultra-performance liquid chromatography coupled to a mass spectrometer (UPLC-MS/MS). The limit of detection (LD) in the soil samples was 0.5 μg Kg-1 and the limit of quantification (LQ) was 3 μg Kg-1, both for glyphosate and AMPA. In water samples the LD was 0.1 μg L-1 and the LQ was 0.5 μg L-1. The results showed that the herbicide dispersed into all the studied environmental compartments. Glyphosate and AMPA residues were detected in 34 and 54% of the stream water samples, respectively. Sediment samples had a higher detection frequency (>96%) than water samples, and there was no relationship between the presence in surface water with the detection in sediment samples. The presence in sediment samples

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. [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

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. [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.

  1. 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

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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。

  4. 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.

  5. 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

    Full Text Available The transport characteristics of phosphorus in soil and the assessment of its environmental risk have become hot topics in the environmental and agricultural fields. The Sanjiang Plain is an important grain production base in China, and it is characterised by serious land use change caused by large-scale agricultural exploitation. Agricultural inputs and tillage management have destroyed the soil nutrient balance formed over long-term conditions. There are few studies on non-point source phosphorus pollution in the Sanjiang Plain, which is the largest swampy low plain in a mid-high-latitude region in China. Most studies have focused on the water quality of rivers in marsh areas, or the export mechanism of phosphorus from specific land uses. They were conducted using experimental methods or empirical models, and need further development towards mechanism models and the macro-scale. The question is how to find a way to couple processes in phosphorus cycling and a distributed hydrological model considering local hydrological features. In this study, we report an attempt to use a distributed phosphorus transport model to analyse non-point source total phosphorus pollution from different land uses and soil types on the Sanjiang Plain. The total phosphorus concentration generally shows an annually increasing trend in the study area. The total phosphorus load intensity is heterogeneous in different land use types and different soil types. The average total phosphorus load intensity of different land use types can be ranked in descending order from paddy field, dry land, wetlands, grassland, and forestland. The average total phosphorus load intensity of different soil types can be ranked in descending order: paddy soil, bog soil, planosol, meadow soil, black soil, and dark brown earth. The dry land and paddy fields account for the majority of total phosphorus load in the study area. This is mainly caused by extensive use of phosphate fertilizer on the

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. [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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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。

  19. 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。

  20. 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.

  1. 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.

  2. {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.

  3. 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.

  4. 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).

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. 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.

  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. 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.

  16. 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

  17. 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).

  18. 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.

  19. 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

  20. 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.

  1. 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。

  2. 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.

  3. 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.

  4. 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

    平原灌区作为农业规模化生产的基地,在农业乃至经济社会发展中起到了重要作用,但是随着农业的发展,平原灌区农田非点源污染问题日益严重,研究平原灌区农田非点源污染具有重要意义。文章以平原灌区污染物随水文循环迁移过程为基础对平原灌区养分非点源污染研究进行综述。(1)平原灌区农田非点源污染的主要来源是过量的化肥施用,农药和农膜,秸秆等农作物的降解,牲畜粪便,污水灌溉,灌溉引起的盐渍化以及大气的干湿沉降等;产生及影响因素主要有土壤的理化性质,水分的输入方式和人为管理措施等。(2)降雨径流及灌溉排水条件下污染物在多级渠系中的迁移规律和灌区地表水与地下水的交互耦合作用决定了平原灌区农田非点源污染的输送途径与特征。(3)在监测资料比较缺乏时,采用输出系数法进行负荷估算;在监测资料充足情况下,采用针对灌区特殊的水文特征而改进的经典水文模型对平原灌区农田非点源污染的负荷进行估算。(4)新型肥料、配方施肥、合理的耕作措施及生态沟渠的设置有利于平原灌区农田非点源污染的控制,TMDL (Total Maximum Daily Loads)为平原灌区农田非点源污染控制提供可靠的依据。针对平原灌区非点源污染研究现状,提出了中国开展平原灌区农田非点源污染研究的重点,包括养分污染物在多级沟渠中的迁移,灌区地表与地下水水量水质耦合模型的建立,分级控制单元与TMDL的制定以及多模型结合模拟等,可望在控制农业非点源污染方面起到指导作用。%Plain irrigation areas as the basis of agricultural large-scale production played an important role in agricultural, economic and social development. However, the seriousness of non-point source pollution in plain irrigation areas is increasing with the

  5. 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

  6. 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

  7. 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...

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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...

  13. 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

  14. 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.

  15. 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,

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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。

  1. 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.

  2. 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.

  3. 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

  4. 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。

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. Mobile sources critical review: 1998 NARSTO assessment

    Science.gov (United States)

    Sawyer, R. F.; Harley, R. A.; Cadle, S. H.; Norbeck, J. M.; Slott, R.; Bravo, H. A.

    Mobile sources of air pollutants encompass a range of vehicle, engine, and fuel combinations. They emit both of the photochemical ozone precursors, hydrocarbons and oxides of nitrogen. The most important source of hydrocarbons and oxides of nitrogen are light- and heavy-duty on-road vehicles and heavy-duty off-road vehicles, utilizing spark and compression ignition engines burning gasoline and diesel respectively. Fuel consumption data provide a convenient starting point for assessing current and future emissions. Modern light-duty, gasoline vehicles when new have very low emissions. The in-use fleet, due largely to emissions from a small "high emitter" fraction, has significantly larger emissions. Hydrocarbons and carbon monoxide are higher than reported in current inventories. Other gasoline powered mobile sources (motorcycles, recreational vehicles, lawn, garden, and utility equipment, and light aircraft) have high emissions on a per quantity of fuel consumed basis, but their contribution to total emissions is small. Additional uncertainties in spatial and temporal distribution of emissions exist. Heavy-duty diesel vehicles are becoming the dominant mobile source of oxides of nitrogen. Oxides of nitrogen emissions may be greater than reported in current inventories, but the evidence for this is mixed. Oxides of nitrogen emissions on a fuel-consumed basis are much greater from diesel mobile sources than from gasoline mobile sources. This is largely the result of stringent control of gasoline vehicle emissions and a lesser (heavy-duty trucks) or no control (construction equipment, locomotives, ships) of heavy-duty mobile sources. The use of alternative fuels, natural gas, propane, alcohols, and oxygenates in motor vehicles is increasing but remains small. Vehicles utilizing these fuels can be but are not necessarily cleaner than their gasoline or diesel counterparts. Historical vehicle kilometers traveled growth rates of about 2% annually in both the United States

  11. 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

  12. 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

  13. 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...

  14. 61 SOURCE-CRITICAL STUDIES IN LUKE-ACTS: IMPLICATIONS ...

    African Journals Online (AJOL)

    HP

    Introduction. Since the nineteenth century, source-critical studies of the Gospels have ... To better appreciate Luke‟s Gospel, we need a literary theory that ...... 12 John Wenham, Redating Matthew, Mark, and Luke: A Fresh Assault on the.

  15. Romantic American Literature: Sources for Criticism. A Research Guide.

    Science.gov (United States)

    Van Noate, Judith, Comp.

    This handout is a guide to library resources in the J. Murrey Atkins Library at the University of North Carolina-Charlotte for the criticism of Romantic (19th century) American literature. The guide explains important reference sources in the Atkins library reference collection and how to find biographical and critical information in books and…

  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. 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.

  19. [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.

  20. 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.

  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. “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.

  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. 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 .

  5. 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.

  6. Critical Exponents for Fast Diffusion Equations with Nonlinear Boundary Sources

    Institute of Scientific and Technical Information of China (English)

    WANG LU-SHENG; WANG ZE-JIA

    2011-01-01

    In this paper, we study the large time behavior of solutions to a class of fast diffusion equations with nonlinear boundary sources on the exterior domain of the unit ball. We are interested in the critical global exponent q0 and the critical Fujita exponent qc for the problem considered, and show that q0 = qc for the multidimensional Non-Newtonian polytropic filtration equation with nonlinear boundary sources, which is quite different from the known results that q0 < qc for the onedimensional case; moreover, the value is different from the slow case.

  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. 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

  9. 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%.

  10. 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.

  11. 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

  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. Stationarity and source convergence in monte carlo criticality calculation.

    Energy Technology Data Exchange (ETDEWEB)

    Ueki, T. (Taro); Brown, F. B. (Forrest B.)

    2002-01-01

    In Monte Carlo (MC) criticality calculations, source error propagation through the stationary cycles and source convergcnce in the settling (inactive) cycles are both dominated by the dominance ratio (DR) of fission kernels, Le., the ratio of the second largest to largest eigenvalues. For symmetric two fissile component systems with DR close to unity, the extinction of fission source sites can occur in one of the components even when the initial source is symmetric and the number of histories per cycle is larger than one thousand. When such a system is made slightly asymmetric, the neutron effective multiplication factor (kern) at the inactive cycles does not reflect the convergence to stationary source distribution. To overcome this problem, relative entropy (Kullback Leibler distance) is applied to a slightly asymmetric two fissile component problem with a dominance ratio of 0.9925. Numerical results show that relative entropy is effective as a posterior diagnostic tool.

  14. 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.

  15. 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.

  16. Agile Methods for Open Source Safety-Critical Software.

    Science.gov (United States)

    Gary, Kevin; Enquobahrie, Andinet; Ibanez, Luis; Cheng, Patrick; Yaniv, Ziv; Cleary, Kevin; Kokoori, Shylaja; Muffih, Benjamin; Heidenreich, John

    2011-08-01

    The introduction of software technology in a life-dependent environment requires the development team to execute a process that ensures a high level of software reliability and correctness. Despite their popularity, agile methods are generally assumed to be inappropriate as a process family in these environments due to their lack of emphasis on documentation, traceability, and other formal techniques. Agile methods, notably Scrum, favor empirical process control, or small constant adjustments in a tight feedback loop. This paper challenges the assumption that agile methods are inappropriate for safety-critical software development. Agile methods are flexible enough to encourage the rightamount of ceremony; therefore if safety-critical systems require greater emphasis on activities like formal specification and requirements management, then an agile process will include these as necessary activities. Furthermore, agile methods focus more on continuous process management and code-level quality than classic software engineering process models. We present our experiences on the image-guided surgical toolkit (IGSTK) project as a backdrop. IGSTK is an open source software project employing agile practices since 2004. We started with the assumption that a lighter process is better, focused on evolving code, and only adding process elements as the need arose. IGSTK has been adopted by teaching hospitals and research labs, and used for clinical trials. Agile methods have matured since the academic community suggested they are not suitable for safety-critical systems almost a decade ago, we present our experiences as a case study for renewing the discussion.

  17. 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.

  18. Selenium speciation from food source to metabolites: a critical review

    Energy Technology Data Exchange (ETDEWEB)

    Dumont, Emmie; Vanhaecke, Frank; Cornelis, Rita [Ghent University, Department of Analytical Chemistry, Ghent (Belgium)

    2006-08-15

    Especially in the last decade, a vast number of papers on Se and its role in health issues have been published. This review gives a brief, critical overview of the main analytical findings reported in these papers. Of particular interest is the Se content in different food sources worldwide and the extent to which their consumption is reflected in the Se content of human tissues and body fluids. Several food sources, both natural (Brazil nuts, garlic, Brassica juncea) and Se-enriched (yeast-based supplements), are discussed as to origin, characteristics, Se metabolism and impact of their consumption on the human body. The continuous development of new and improvement of existing analytical techniques has provided different powerful tools to unravel the Se species and their function. An up-to-date literature study on Se speciation analysis is given, illustrating how analytical chemistry in its different facets aids in the identification of Se compounds and provides insight into the complete metabolic pathway of Se throughout the human body. This review includes a detailed image of the current state-of-the-art of Se speciation analysis in these food sources and in human tissues and body fluids. (orig.)

  19. 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

  20. 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

  1. 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...

  2. 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。

  3. 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.

  4. 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

  5. Arab Americans: A Comparative Critical Analysis of Leading Reference Sources.

    Science.gov (United States)

    Wertsman, Vladimir F.

    2001-01-01

    Examines eight reference sources on Arab Americans to investigate how complete the information is on various facets of Arab American presence, history, community life, heritage preservation, organizations, and the press, concluding that the reference sources complement each other, but taken together, they do not cover the entire multidimensional…

  6. 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

  7. Critical Analysis on Open Source LMSs Using FCA

    Science.gov (United States)

    Sumangali, K.; Kumar, Ch. Aswani

    2013-01-01

    The objective of this paper is to apply Formal Concept Analysis (FCA) to identify the best open source Learning Management System (LMS) for an E-learning environment. FCA is a mathematical framework that represents knowledge derived from a formal context. In constructing the formal context, LMSs are treated as objects and their features as…

  8. Critical Analysis on Open Source LMSs Using FCA

    Science.gov (United States)

    Sumangali, K.; Kumar, Ch. Aswani

    2013-01-01

    The objective of this paper is to apply Formal Concept Analysis (FCA) to identify the best open source Learning Management System (LMS) for an E-learning environment. FCA is a mathematical framework that represents knowledge derived from a formal context. In constructing the formal context, LMSs are treated as objects and their features as…

  9. T-S criticality of black holes with power Maxwell invariant source

    Science.gov (United States)

    Lin, Ze-Tao; Li, Gu-Qiang; Long, Kun; He, Fang; Mo, Jie-Xiong

    2017-09-01

    In this paper, we show that black holes with PMI source exhibit the T-S criticality and derive the relevant critical physical quantities analytically. The values of critical quantities for the case s≠1 vary from those for the case s=1, showing the effect of PMI field on the critical phenomena of black holes. When qPMI field does not affect the Maxwell equal area law.

  10. 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

  11. Asymptotically approaching the past: historiography and critical use of sources in art technological source research

    NARCIS (Netherlands)

    M. Clarke

    2006-01-01

    This paper proposes that historiographic methods should be applied during art technological source research. Sources cannot always be used uncritically as being simply reliable records of contemporary workshop practice. The accuracy, date and origin of the technical information embedded within sourc

  12. 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

  13. 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

  14. Qualitative Research and Narrative Sources in the Context of Critical and Renal Cares

    OpenAIRE

    Siles González, José; Solano Ruiz, María del Carmen

    2014-01-01

    The objective of this study is to clarify the relevance of qualitative research in the context of critical care and renal dialysis requires using narrative sources. Also specific objectives are to identify the phases or cultural moments that are distinguished in these processes. Research Question: How can the narrative materials contribute to the study of the processes of critical care and/or qualitative research in nephrology? Method and Sources: There have been studies focusing on the narra...

  15. Critical source times for nutrient loss in agricultural catchment streams

    Science.gov (United States)

    Melland, Alice; Shore, Mairead; Mellander, Per-Erik; McDonald, Noeleen; Shortle, Ger; Murphy, Paul; Jordan, Phil

    2014-05-01

    informed by farm practice and nutrient flow pathways analysis. Losses after the closed period, especially P, could include a significant contribution from eroded soil, which would not be prevented by extending the spreading closed period. Policy proposals to extend the mandatory closed period should consider the long term potential for nutrient runoff and plant growth conditions during the 'shoulder' periods, infrastructure costs of further storage requirements, production costs of restricting critical farm operations during the shoulders and unintended environmental costs such as shifting farm activities towards periods when water bodies are more susceptible to eutrophication.

  16. 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

  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. 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

  19. 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

  20. Critical Source-text Reading in English-Chinese News Translation

    Institute of Scientific and Technical Information of China (English)

    侯松

    2007-01-01

    Critical Discourse Analysis(CDA),a critical approach to discourse analytical research which combines textual analysis and social theories,has shown that English news texts are often ideologically invested.English-Chinese(E-C)new translators at work,therefore,should critically read the source text to reveal those ideologies by firstly occupy a reading position and then perform a somewhat less-systematic CDA on it.After a critical reading,three different types of translating strategies are available for the translator.They are:(1)uncritical translating;(2)neutral translating;(3)radical translating,among which neutral translating may be the more desirable.

  1. 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

  2. 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.

  3. Source criticism in the classroom: An empiricist straitjacket on pupils’ historical thinking?

    Directory of Open Access Journals (Sweden)

    David Rosenlund

    2015-05-01

    Full Text Available The concept of source criticism has long had a central role in Swedish history curricula. In this essay, the concept is analysed in three contexts. First, a growing epistemological discrepancy is identified over time with regard to the ways in which the aim of history teaching and the use of source criticism is set down in school curricula. The aim of teaching history has changed towards a more post-structuralist approach, while the concept of source criticism is still described from a more empiricist, epistemological stance. In a second context, Swedish history textbooks are found to use the concept of source criticism in an empiricist, epistemological way. In a third context, upper secondary pupils seem to be confused, navigating between two incompatible epistemological views of historical knowledge. The essay ends with a discussion on how to convert the use of source criticism - from the strait jacket it seems to put on pupils historical thinking, to the necessary and helpful tool it should be.

  4. Critical review of black carbon and elemental carbon source apportionment in Europe and the United States

    Science.gov (United States)

    Briggs, Nicole L.; Long, Christopher M.

    2016-11-01

    An increasing number of air pollution source apportionment studies in Europe and the United States have focused on the black carbon (BC) fraction of ambient particulate matter (PM) given its linkage with adverse public health and climate impacts. We conducted a critical review of European and US BC source apportionment studies published since 2003. Since elemental carbon (EC) has been used as a surrogate measure of BC, we also considered source apportionment studies of EC measurements. This review extends the knowledge presented in previous ambient PM source apportionment reviews because we focus on BC and EC and critically examine the differences between source apportionment results for different methods and source categories. We identified about 50 BC and EC source apportionment studies that have been conducted in either Europe or the US since 2003, finding a striking difference in the commonly used source apportionment methods between the two regions and variations in the assigned source categories. Using three dominant methodologies (radiocarbon, aethalometer, and macro-tracer methods) that only allow for BC to be broadly apportioned into either fossil fuel combustion or biomass burning source categories, European studies generally support fossil fuel combustion as the dominant ambient BC source, but also show significant biomass burning contributions, in particular in wintertime at non-urban locations. Among US studies where prevailing methods such as chemical mass balance (CMB) and positive matrix factorization (PMF) models have allowed for estimation of more refined source contributions, there are fewer findings showing the significance of biomass burning and variable findings on the relative proportion of BC attributed to diesel versus gasoline emissions. Overall, the available BC source apportionment studies provide useful information demonstrating the significance of both fossil fuel combustion and biomass burning BC emission sources in Europe and the US

  5. 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.

  6. 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

  7. 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...

  8. 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.

  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. 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

  11. The Use of LiDAR Elevation Data and Satellite Imagery to Locate Critical Source Areas to Diffuse Pollution in Agricultural Watersheds

    Science.gov (United States)

    Drouin, Ariane; Michaud, Aubert; Thériault, Georges; Beaudin, Isabelle; Rodrigue, Jean-François; Denault, Jean-Thomas; Desjardins, Jacques; Côté, Noémi

    2013-04-01

    In Quebec / Canada, water quality improvement in rural areas greatly depends on the reduction of diffuse pollution. Indeed, point source pollution has been reduced significantly in Canada in recent years by creating circumscribed pits for manure and removing animals from stream. Diffuse pollution differs from point source pollution because it is spread over large areas. In agricultural areas, sediment loss by soil and riverbank erosion along with loss of nutrients (phosphorus, nitrogen, etc.) and pesticides from fields represent the main source of non-point source pollution. The factor mainly responsible for diffuse pollution in agricultural areas is surface runoff occurring in poorly drained areas in fields. The presence of these poorly drained areas is also one of the most limiting factors in crop productivity. Thus, a reconciliation of objectives at the farm (financial concern for farmers) and off-farm concerns (environmental concern) is possible. In short, drainage, runoff, erosion, water quality and crop production are all interconnected issues that need to be tackled together. Two complementary data sources are mainly used in the diagnosis of drainage, surface runoff and erosion : elevation data and multispectral satellite images. In this study of two watersheds located in Québec (Canada), LiDAR elevation data and satellite imagery (QuickBird, Spot and Landsat) were acquired. The studied territories have been partitioned in hydrologic response units (HRUs) according to sub-basins, soils, elevation (topographic index) and land use. These HRUs are afterwards used in a P index software (P-Edit) that calculates the quantities of sediments and phosphorus exported from each HRUs. These exports of sediments and phosphorus are validated with hydrometric and water quality data obtain in two sub-basins and are also compared to soil brightness index derived from multispectral images. This index is sensitive to soil moisture and thus highlights areas where the soil is

  12. "Hearing" the Story: Critical Indigenous Curriculum Inquiry and Primary Source Representation in Social Studies Education

    Science.gov (United States)

    Stanton, Christine Rogers

    2012-01-01

    Although primary source accounts provide students with direct access to the experiences of historical participants, they can reinforce the dominant culture historical narrative if misrepresented by teachers, curriculum publishers, or scholars. The author demonstrates the importance of adhering to guidelines presented by critical Indigenous…

  13. Red mud as secondary source for critical raw materials - extraction study

    NARCIS (Netherlands)

    Ujaczki, Éva; Zimmermann, Yannick S.; Gasser, Christoph A.; Molnár, Mónika; Feigl, Viktória; Lenz, Markus

    2017-01-01

    BACKGROUND: Red mud is a by-product of alumina extraction from bauxite by the Bayer process produced in the billion tons scale worldwide. Red muds, or more generally bauxite residues, are regarded as waste, but may potentially be valuable sources of critical raw materials (CRM). In the present study

  14. China Experimental Fast Reactor(CEFR)——Criterion of Criticality for Reactor With External Neutron Source

    Institute of Scientific and Technical Information of China (English)

    ZHAOYu-sen

    2003-01-01

    There is a neutron source with 109 s-1 neutrons in core of CEFR during start up test and operation of CEFR. For judging the criticality of reactor with external neutron source and near criticality, it is important that the neutron level changes in core with time must be understood after introducing positive reactivity to core with external neutron source.

  15. Spectra of Random Hermitian Matrices with a Small-Rank External Source: The critical and near-critical regimes

    CERN Document Server

    Bertola, Marco; Lee, Seung-Yeop; Pierce, Virgil U

    2010-01-01

    Random Hermitian matrices are used to model complex systems without time-reversal invariance. Adding an external source to the model can have the effect of shifting some of the matrix eigenvalues, which corresponds to shifting some of the energy levels of the physical system. We consider the case when the $n\\times n$ external source matrix has two distinct real eigenvalues: $a$ with multiplicity $r$ and zero with multiplicity $n-r$. For a Gaussian potential, it was shown by P\\'ech\\'e \\cite{Peche:2006} that when $r$ is fixed or grows sufficiently slowly with $n$ (a small-rank source), $r$ eigenvalues are expected to exit the main bulk for $|a|$ large enough. Furthermore, at the critical value of $a$ when the outliers are at the edge of a band, the eigenvalues at the edge are described by the $r$-Airy kernel. We establish the universality of the $r$-Airy kernel for a general class of analytic potentials for $r=\\mathcal{O}(n^\\gamma)$ for $0\\leq\\gamma<1/12$.

  16. Understanding Bulk Power Reliability: The Importance of Good Data and A Critical Review of Existing Sources

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Emily; Eto, Joseph H.; LaCommare, Kristina Hamachi

    2011-10-19

    Bulk power system reliability is of critical importance to the electricity sector. Complete and accurate information on events affecting the bulk power system is essential for assessing trends and efforts to maintain or improve reliability. Yet, current sources of this information were not designed with these uses in mind. They were designed, instead, to support real-time emergency notification to industry and government first-responders. This paper reviews information currently collected by both industry and government sources for this purpose and assesses factors that might affect their usefulness in supporting the academic literature that has relied upon them to draw conclusions about the reliability of the US electric power system.

  17. Evolving Relationship Structures in Multi-sourcing Arrangements: The Case of Mission Critical Outsourcing

    Science.gov (United States)

    Heitlager, Ilja; Helms, Remko; Brinkkemper, Sjaak

    Information Technology Outsourcing practice and research mainly considers the outsourcing phenomenon as a generic fulfilment of the IT function by external parties. Inspired by the logic of commodity, core competencies and economies of scale; assets, existing departments and IT functions are transferred to external parties. Although the generic approach might work for desktop outsourcing, where standardisation is the dominant factor, it does not work for the management of mission critical applications. Managing mission critical applications requires a different approach where building relationships is critical. The relationships involve inter and intra organisational parties in a multi-sourcing arrangement, called an IT service chain, consisting of multiple (specialist) parties that have to collaborate closely to deliver high quality services.

  18. 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。

  19. 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

  20. Who says we are bad people? The impact of criticism source and attributional content on responses to group-based criticism.

    Science.gov (United States)

    Rabinovich, Anna; Morton, Thomas A

    2010-04-01

    We investigated the interplay between the source of criticism and the attributional content of their message on behavioral responses to group-based criticism. Studies 1 and 2 revealed that outgroup critics were more effective when their criticism included internal attributions (to the ingroup's character) rather than external attributions (the ingroup's circumstances), whereas there was no effect of attributional content for ingroup critics (a significant Source x Content interaction). Study 3 explored the role of audiences in responses to outgroup criticism. The results indicated that the positive effects of internal versus external attributions were only evident when an outgroup audience was witness to participants' responses. Furthermore, these effects were mediated through concerns about the ingroup's image. Together, these patterns suggest that responses to criticism depend not just on the identity of the critic but also on what the critic says and who is watching. People may be surprisingly responsive to outgroup criticism-particularly when inaction might lead others to perceive them as "bad people."

  1. Oscillating line source in a shear flow with a free surface: critical layer-like contributions

    CERN Document Server

    Ellingsen, Simen Å

    2016-01-01

    The linearized water-wave radiation problem for an oscillating submerged line source in an inviscid shear flow with a free surface is investigated analytically at finite, constant depth in the presence of a shear flow varying linearly with depth. The surface velocity is taken to be zero relative to the oscillating source, so that Doppler effects are absent. The radiated wave out from the source is calculated based on Euler's equation of motion with the appropriate boundary and radiation conditions, and differs substantially from the solution obtained by assuming potential flow. To wit, an additional wave is found in the downstream direction in addition to the previously known dispersive wave solutions; this wave is non-dispersive and we show how it is the surface manifestation of a critical layer-like flow generated by the combination of shear and mass flux at the source, passively advected with the flow. As seen from a system moving at the fluid velocity at the source's depth, streamlines form closed curves ...

  2. [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.

  3. An Open-Source Implementation of the Critical-Line Algorithm for Portfolio Optimization

    Directory of Open Access Journals (Sweden)

    David H. Bailey

    2013-03-01

    Full Text Available Portfolio optimization is one of the problems most frequently encountered by financial practitioners. The main goal of this paper is to fill a gap in the literature by providing a well-documented, step-by-step open-source implementation of Critical Line Algorithm (CLA in scientific language. The code is implemented as a Python class object, which allows it to be imported like any other Python module, and integrated seamlessly with pre-existing code. We discuss the logic behind CLA following the algorithm’s decision flow. In addition, we developed several utilities that support finding answers to recurrent practical problems. We believe this publication will offer a better alternative to financial practitioners, many of whom are currently relying on generic-purpose optimizers which often deliver suboptimal solutions. The source code discussed in this paper can be downloaded at the authors’ websites (see Appendix.

  4. A critical evaluation of semianalytic methods in the study of centrally heated, unresolved, infrared sources

    Science.gov (United States)

    Doty, Steven D.; Leung, Chun Ming

    1994-01-01

    We critically evaluate current methods of analysis in infrared (IR) astronomy and investigate the conditions under which these semianalytic methods are reliable. Specifically we examine the usual assumptions of homogeneities in dust density and temperature, and neglect of opacity effects when applied to internally heated, unresolved IR sources. To accomplish this, a series of radiation transport models for these sources have been constructed. The model results are treated as observed quantities and analyzed to derive the source parameters, using simple semianalytic methods. The discrepancies between the derived and actual model parameters can then be attributed to the limitations of the analysis methods and provide a measure of their reliability. Applying this approach to centrally heated, unresolved IR sources, we have studied in detail the following diagnostic problems: (1) determination of dust mass from monochromatic and integrated luminosities; (2) estimation of dust temperature distribution from color temperatures derived from the flux spectrum; and (3) determination of the empirical grain emissivity law (opacity function) for both continuum and spectral features.

  5. Determinants of the accuracy of nursing diagnoses: influence of ready knowledge, knowledge sources, disposition toward critical thinking, and reasoning skills.

    Science.gov (United States)

    Paans, Wolter; Sermeus, Walter; Nieweg, Roos; van der Schans, Cees

    2010-01-01

    The purpose of this study was to determine how knowledge sources, ready knowledge, and disposition toward critical thinking and reasoning skills influence the accuracy of student nurses' diagnoses. A randomized controlled trial was conducted to determine the influence of knowledge sources. We used the following questionnaires: (a) knowledge inventory, (b) California Critical Thinking Disposition Inventory, and (c) Health Science Reasoning Test (HSRT). The use of knowledge sources had very little influence on the accuracy of nursing diagnoses. Accuracy was significantly related to the analysis domain of the HSRT. Students were unable to operationalize knowledge sources to derive accurate diagnoses and did not effectively use reasoning skills. Copyright 2010 Elsevier Inc. All rights reserved.

  6. Physics-Based Hazard Assessment for Critical Structures Near Large Earthquake Sources

    Science.gov (United States)

    Hutchings, L.; Mert, A.; Fahjan, Y.; Novikova, T.; Golara, A.; Miah, M.; Fergany, E.; Foxall, W.

    2017-06-01

    We argue that for critical structures near large earthquake sources: (1) the ergodic assumption, recent history, and simplified descriptions of the hazard are not appropriate to rely on for earthquake ground motion prediction and can lead to a mis-estimation of the hazard and risk to structures; (2) a physics-based approach can address these issues; (3) a physics-based source model must be provided to generate realistic phasing effects from finite rupture and model near-source ground motion correctly; (4) wave propagations and site response should be site specific; (5) a much wider search of possible sources of ground motion can be achieved computationally with a physics-based approach; (6) unless one utilizes a physics-based approach, the hazard and risk to structures has unknown uncertainties; (7) uncertainties can be reduced with a physics-based approach, but not with an ergodic approach; (8) computational power and computer codes have advanced to the point that risk to structures can be calculated directly from source and site-specific ground motions. Spanning the variability of potential ground motion in a predictive situation is especially difficult for near-source areas, but that is the distance at which the hazard is the greatest. The basis of a "physical-based" approach is ground-motion syntheses derived from physics and an understanding of the earthquake process. This is an overview paper and results from previous studies are used to make the case for these conclusions. Our premise is that 50 years of strong motion records is insufficient to capture all possible ranges of site and propagation path conditions, rupture processes, and spatial geometric relationships between source and site. Predicting future earthquake scenarios is necessary; models that have little or no physical basis but have been tested and adjusted to fit available observations can only "predict" what happened in the past, which should be considered description as opposed to prediction

  7. Critical analysis of documentary sources for Historical Climatology of Northern Portugal (17th-19th centuries)

    Science.gov (United States)

    Amorim, Inês; Sousa Silva, Luís; Garcia, João Carlos

    2017-04-01

    Critical analysis of documentary sources for Historical Climatology of Northern Portugal (17th-19th centuries) Inês Amorim CITCEM, Department of History, Political and International Studies, U. of Porto, Portugal. Luís Sousa Silva CITCEM, PhD Fellowship - FCT. João Carlos Garcia CIUHCT, Geography Department, U. of Porto, Portugal. The first major national project on Historical Climatology in Portugal, called "KLIMHIST: Reconstruction and model simulations of past climate in Portugal using documentary and early instrumental sources (17th-19th centuries)", ended in September 2015, coordinated by Maria João Alcoforado. This project began in March 2012 and counted on an interdisciplinary team of researchers from four Portuguese institutions (Centre of Geographical Studies, University of Trás-os-Montes and Alto Douro, University of Porto, and University of Évora), from different fields of knowledge (Geography, History, Biology, Climatology and Meteorology). The team networked and collaborated with other international research groups on Climate Change and Historical Climatology, resulting in several publications. This project aimed to reconstruct thermal and rainfall patterns in Portugal between the 17th and 19th centuries, as well as identify the main hydrometeorological extremes that occurred over that period. The basic methodology consisted in combining information from different types of anthropogenic sources (descriptive and instrumental) and natural sources (tree rings and geothermal holes), so as to develop climate change models of the past. The data collected were stored in a digital database, which can be searched by source, date, location and type of event. This database, which will be made publically available soon, contains about 3500 weather/climate-related records, which have begun to be studied, processed and published. Following this seminal project, other initiatives have taken place in Portugal in the area of Historical Climatology, namely a Ph

  8. A Critical Review of Naphthalene Sources and Exposures Relevant to Indoor and Outdoor Air

    Directory of Open Access Journals (Sweden)

    Chunrong Jia

    2010-07-01

    Full Text Available Both the recent classification of naphthalene as a possible human carcinogen and its ubiquitous presence motivate this critical review of naphthalene’s sources and exposures. We evaluate the environmental literature on naphthalene published since 1990, drawing on nearly 150 studies that report emissions and concentrations in indoor, outdoor and personal air. While naphthalene is both a volatile organic compound and a polycyclic aromatic hydrocarbon, concentrations and exposures are poorly characterized relative to many other pollutants. Most airborne emissions result from combustion, and key sources include industry, open burning, tailpipe emissions, and cigarettes. The second largest source is off-gassing, specifically from naphthalene’s use as a deodorizer, repellent and fumigant. In the U.S., naphthalene’s use as a moth repellant has been reduced in favor of para-dichlorobenzene, but extensive use continues in mothballs, which appears responsible for some of the highest indoor exposures, along with off-label uses. Among the studies judged to be representative, average concentrations ranged from 0.18 to 1.7 μg m-3 in non-smoker’s homes, and from 0.02 to 0.31 μg m-3 outdoors in urban areas. Personal exposures have been reported in only three European studies. Indoor sources are the major contributor to (non-occupational exposure. While its central tendencies fall well below guideline levels relevant to acute health impacts, several studies have reported maximum concentrations exceeding 100 μg m-3, far above guideline levels. Using current but draft estimates of cancer risks, naphthalene is a major environmental risk driver, with typical individual risk levels in the 10-4 range, which is high and notable given that millions of individuals are exposed. Several factors influence indoor and outdoor concentrations, but the literature is inconsistent on their effects. Further investigation is needed to better characterize naphthalene

  9. Source Code Prioritization Using Forward Slicing for Exposing Critical Elements in a Program

    Institute of Scientific and Technical Information of China (English)

    Mitrabinda Ray; Kanhaiya lal Kumawat; Durga Prasad Mohapatra

    2011-01-01

    Even after thorough testing, a few bugs still remain in a program with moderate complexity. These residual bugs are randomly distributed throughout the code. We have noticed that bugs in some parts of a program cause frequent and severe failures compared to those in other parts. Then, it is necessary to take a decision about what to test more and what to test less within the testing budget. It is possible to prioritize the methods and classes of an object-oriented program according to their potential to cause failures. For this, we propose a program metric called influence metric to find the influence of a program element on the source code. First, we represent the source code into an intermediate graph called extended system dependence graph. Then, forward slicing is applied on a node of the graph to get the influence of that node. The influence metric for a method m in a program shows the number of statements of the program which directly or indirectly use the result produced by method m. We compute the influence metric for a class c based on the influence metric of all its methods. As influence metric is computed statically, it does not show the expected behavior of a class at run time. It is already known that faults in highly executed parts tend to more failures. Therefore, we have considered operational profile to find the average execution time of a class in a system. Then, classes are prioritized in the source code based on influence metric and average execution time. The priority of an element indicates the potential of the element to cause failures. Once all program elements have been prioritized, the testing effort can be apportioned so that the elements causing frequent failures will be tested thoroughly. We have conducted experiments for two well-known case studies -- Library Management System and Trading Automation System -- and successfully identified critical elements in the source code of each case study. We have also conducted experiments to

  10. Adiabatic heating and convection caused by a fixed-heat-flux source in a near-critical fluid.

    Science.gov (United States)

    Soboleva, E B

    2003-10-01

    Dynamics and heat transfer in a near-critical fluid in a square cavity with a finite heat source located at the bottom are studied numerically. A thermally insulated enclosure and a fixed-heat-flux source are considered. The two-dimensional simulation is based on the full Navier-Stokes equations with two-scale splitting of the pressure and the van der Waals equation of state. It is shown that the piston effect is independent of convection. Near the critical point, this effect becomes independent of criticality and convective motions are damped.

  11. Geochemical characterization of critical dust source regions in the American West

    Science.gov (United States)

    Aarons, Sarah M.; Blakowski, Molly A.; Aciego, Sarah M.; Stevenson, Emily I.; Sims, Kenneth W. W.; Scott, Sean R.; Aarons, Charles

    2017-10-01

    The generation, transport, and deposition of mineral dust are detectable in paleoclimate records from land, ocean, and ice, providing valuable insight into earth surface conditions and cycles on a range of timescales. Dust deposited in marine and terrestrial ecosystems can provide critical nutrients to nutrient-limited ecosystems, and variations in dust provenance can indicate changes in dust production, sources and transport pathways as a function of climate variability and land use change. Thus, temporal changes in locations of dust source areas and transport pathways have implications for understanding interactions between mineral dust, global climate, and biogeochemical cycles. This work characterizes dust from areas in the American West known for dust events and/or affected by increasing human settlement and livestock grazing during the last 150 years. Dust generation and uplift from these dust source areas depends on climate and land use practices, and the relative contribution of dust has likely changed since the expansion of industrialization and agriculture into the western United States. We present elemental and isotopic analysis of 28 potential dust source area samples analyzed using Thermal Ionization Mass Spectrometry (TIMS) for 87Sr/86Sr and 143Nd/144Nd composition and Multi-Collector Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS) for 176Hf/177Hf composition, and ICPMS for major and trace element concentrations. We find significant variability in the Sr, Nd, and Hf isotope compositions of potential source areas of dust throughout western North America, ranging from 87Sr/86Sr = 0.703699 to 0.740236, εNd = -26.6 to 2.4, and εHf = -21.7 to -0.1. We also report differences in the trace metal and phosphorus concentrations in the geologic provinces sampled. This research provides an important resource for the geochemical tracing of dust sources and sinks in western North America, and will aid in modeling the biogeochemical impacts of increased

  12. DETERMINANTS OF THE ACCURACY OF NURSING DIAGNOSES : INFLUENCE OF READY KNOWLEDGE, KNOWLEDGE SOURCES, DISPOSITION TOWARD CRITICAL THINKING, AND REASONING SKILLS

    NARCIS (Netherlands)

    Paans, Wolter; Sermeus, Walter; Nieweg, Roos; Van der Schans, Cees

    2010-01-01

    The purpose of this study was to determine how knowledge sources, ready knowledge, and disposition toward critical thinking and reasoning skills influence the accuracy of student nurses' diagnoses. A randomized controlled trial was conducted to determine the influence of knowledge sources. We used t

  13. Using Internet Primary Sources To Teach Critical Thinking Skills in History. Greenwood Professional Guides in School Librarianship.

    Science.gov (United States)

    Craver, Kathleen W.

    The purpose of this book is to discuss and demonstrate how primary sources found on the Internet can be used to teach critical thinking skills for U.S. history and world history students in grades 7-12. The volume also provides guidelines and sample suggestions and questions for using primary sources in a variety of formats to stimulate critical…

  14. DETERMINANTS OF THE ACCURACY OF NURSING DIAGNOSES : INFLUENCE OF READY KNOWLEDGE, KNOWLEDGE SOURCES, DISPOSITION TOWARD CRITICAL THINKING, AND REASONING SKILLS

    NARCIS (Netherlands)

    Paans, Wolter; Sermeus, Walter; Nieweg, Roos; Van der Schans, Cees

    2010-01-01

    The purpose of this study was to determine how knowledge sources, ready knowledge, and disposition toward critical thinking and reasoning skills influence the accuracy of student nurses' diagnoses. A randomized controlled trial was conducted to determine the influence of knowledge sources. We used

  15. Causality, criticality, and reading words: distinct sources of fractal scaling in behavioral sequences.

    Science.gov (United States)

    Moscoso del Prado Martín, Fermín

    2011-07-01

    The finding of fractal scaling (FS) in behavioral sequences has raised a debate on whether FS is a pervasive property of the cognitive system or is the result of specific processes. Inferences about the origins of properties in time sequences are causal. That is, as opposed to correlational inferences reflecting instantaneous symmetrical relations, causal inferences concern asymmetric relations lagged in time. Here, I integrate Granger-causality with inferences about FS. Four simulations illustrate that causal analyses can isolate distinct FS sources, whereas correlational techniques cannot. I then analyze three simultaneous sequences of responses from a database of word-naming trials. I find that two, or perhaps three, distinct sources account for the presence of FS in these sequences, but FS is not a general property of the system. This suggests that FS arises due to the properties of a limited number of identifiable psychological and/or neural processes. Finally, I reanalyze a previously published dataset of acoustic frequency spectra using the new tools. The causality/criticality combination introduced here offers a new important perspective in the study of cognition. Copyright © 2011 Cognitive Science Society, Inc.

  16. [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.

  17. Phosphorus content of ditch sediments as indicator of critical source areas (Research Note

    Directory of Open Access Journals (Sweden)

    H. JANSSON

    2008-12-01

    Full Text Available An inexpensive method for identifying high phosphorus (P loads on ditches carrying water from critical source areas ("hot spots", i.e. manure-affected areas was tested. Water flowing from the hot-spot areas is rich in dissolved nutrients (e.g. P and nutrient-rich eroded material. In this study the water from hot spots contained an average of 2.2 mg/l dissolved reactive P but field ditch water 0.14 mg/l. We selected 62 ditches with varying P-load levels for sediment analysis. Five ponds and 16 lakes were also studied. The sediment samples were analysed by the AAAc-extraction (0.5 M ammonium acetate, 0.5 M acetic acid, pH 4.65 method used for routine soil testing in Finland. The analysis of sediment AAAc-P proved to be a useful method for identifying ditches carrying high P waters from hot spots. Half of the ditch sediments in the hot spot ditches showed high or excessive P concentrations. AAAc extraction of the sediment is less expensive than water analysis and the sampling can be extended to periods when no water flows in the ditches.;

  18. Fission reactor neutron sources for neutron capture therapy--a critical review.

    Science.gov (United States)

    Harling, Otto K; Riley, Kent J

    2003-01-01

    The status of fission reactor-based neutron beams for neutron capture therapy (NCT) is reviewed critically. Epithermal neutron beams, which are favored for treatment of deep-seated tumors, have been constructed or are under construction at a number of reactors worldwide. Some of the most recently constructed epithermal neutron beams approach the theoretical optimum for beam purity. Of these higher quality beams, at least one is suitable for use in high through-put routine therapy. It is concluded that reactor-based epithermal neutron beams with near optimum characteristics are currently available and more can be constructed at existing reactors. Suitable reactors include relatively low power reactors using the core directly as a source of neutrons or a fission converter if core neutrons are difficult to access. Thermal neutron beams for NCT studies with small animals or for shallow tumor treatments, with near optimum properties have been available at reactors for many years. Additional high quality thermal beams can also be constructed at existing reactors or at new, small reactors. Furthermore, it should be possible to design and construct new low power reactors specifically for NCT, which meet all requirements for routine therapy and which are based on proven and highly safe reactor technology.

  19. Hypothesis of self-organized criticality and non double couple seismic sources

    Science.gov (United States)

    Yunga, S.; Lutikov, A.

    2009-04-01

    The analysis of deformation process in earthquakes foci makes it possible to get a better insight into various aspects of faulting and earthquakes in real media. Seismic process depends on distribution of stresses in a volume of rocks. Qualitative analysis of the redistribution of stresses in an elastic medium with scaling organization of faults demonstrate that the inhomogenity of stresses near tips of such fault zones is altered drastically. It has been shown that of great importance are regional variations in the stress state caused by the processes of redistribution of crustal stresses during seismic activity in the region as well as by more distant seismogeodynamic processes on interplate boundaries. The hypothesis that seismicity may be considered as self-organized critical process (SOC) take into consideration multi-scale hierarchical structure of real geological medium and its heterogeneity. In result the SOC approach leads to rather well description of earthquakes statistics (first of all the Gutenberg - Richter law) but up to now it was not so helpful for understanding of individual EQ-triggering process at local scale level. On the other hand, current seismological observations suggest that the pattern of seismic waves from some earthquakes cannot be produced by slip along a planar fault surface. Other physical mechanism is required to explain the observed varieties of these non-double-couple earthquakes (NDC). The specific mechanisms underlying NDC are not always clear. The most common explanation currently is that these earthquakes are complex, with stress released on several non-parallel fault surfaces. Thus NDC sources are considered as a result of complicated fault geometry and its segmentation during the process of seismic rupture. As concerned the interaction mechanisms, the SOC approach also implies a possibility of collective (ensemble) interaction. The system in a state of SOC oscillates about a state of marginal stability with a series of slip

  20. 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.

  1. 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.

  2. 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

  3. Probing the critical zone using passive- and active-source estimates of subsurface shear-wave velocities

    Science.gov (United States)

    Callahan, R. P.; Taylor, N. J.; Pasquet, S.; Dueker, K. G.; Riebe, C. S.; Holbrook, W. S.

    2016-12-01

    Geophysical imaging is rapidly becoming popular for quantifying subsurface critical zone (CZ) architecture. However, a diverse array of measurements and measurement techniques are available, raising the question of which are appropriate for specific study goals. Here we compare two techniques for measuring S-wave velocities (Vs) in the near surface. The first approach quantifies Vs in three dimensions using a passive source and an iterative residual least-squares tomographic inversion. The second approach uses a more traditional active-source seismic survey to quantify Vs in two dimensions via a Monte Carlo surface-wave dispersion inversion. Our analysis focuses on three 0.01 km2 study plots on weathered granitic bedrock in the Southern Sierra Critical Zone Observatory. Preliminary results indicate that depth-averaged velocities from the two methods agree over the scales of resolution of the techniques. While the passive- and active-source techniques both quantify Vs, each method has distinct advantages and disadvantages during data acquisition and analysis. The passive-source method has the advantage of generating a three dimensional distribution of subsurface Vs structure across a broad area. Because this method relies on the ambient seismic field as a source, which varies unpredictably across space and time, data quality and depth of investigation are outside the control of the user. Meanwhile, traditional active-source surveys can be designed around a desired depth of investigation. However, they only generate a two dimensional image of Vs structure. Whereas traditional active-source surveys can be inverted quickly on a personal computer in the field, passive source surveys require significantly more computations, and are best conducted in a high-performance computing environment. We use data from our study sites to compare these methods across different scales and to explore how these methods can be used to better understand subsurface CZ architecture.

  4. 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.

  5. Source criticism and cultural models: constructing life histories of women missionaries

    Directory of Open Access Journals (Sweden)

    Eila Helander

    1999-01-01

    Full Text Available Research work is an interpretive enterprise. The variety of sources poses some central methodological questions for constructing religious life histories. There is an apparent discrepancy between the source categories concerning the content of the information. Private diaries and letters provide information on women's work and life which is not available in official reports and letters. They reveal dates, events and individuals which are not mentioned elsewhere. In histography the question of discrepancy is normally solved by comparing the sources with an aim to arrive at the "true picture" of how things have been. Such a picture is believed to portray not only the true life situation of the individual or group in question but, depending on the nature of the data, also the epoch and time situation itself. From the viewpoint of social sciences and comparative religion one will ask: could the variety of sources be approached and utilized in some other way? The second question posed by the data concerns the content of each source category. The information can be located on the continuum "highly subjective — stereotyped". Subjective information, including reflections on personal experiences may not be the best source e.g. for constructing the flow of historical events, but it is of uttermost importance if we want to show how individuals respond to social constraints and actively assemble social worlds.

  6. 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.

  7. 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.

  8. Isotope ratio mass spectrometry as a tool for source inference in forensic science: A critical review.

    Science.gov (United States)

    Gentile, Natacha; Siegwolf, Rolf T W; Esseiva, Pierre; Doyle, Sean; Zollinger, Kurt; Delémont, Olivier

    2015-06-01

    Isotope ratio mass spectrometry (IRMS) has been used in numerous fields of forensic science in a source inference perspective. This review compiles the studies published on the application of isotope ratio mass spectrometry (IRMS) to the traditional fields of forensic science so far. It completes the review of Benson et al. [1] and synthesises the extent of knowledge already gathered in the following fields: illicit drugs, flammable liquids, human provenancing, microtraces, explosives and other specific materials (packaging tapes, safety matches, plastics, etc.). For each field, a discussion assesses the state of science and highlights the relevance of the information in a forensic context. Through the different discussions which mark out the review, the potential and limitations of IRMS, as well as the needs and challenges of future studies are emphasized. The paper elicits the various dimensions of the source which can be obtained from the isotope information and demonstrates the transversal nature of IRMS as a tool for source inference.

  9. Critical Aspects of Modern Open Source SoftwareTechnology to Support Emerging Demands

    CERN Document Server

    Farooq, Umer; Shabbir, Usman; Nazir, Sohail; 10.5120/3330-4580

    2011-01-01

    Software has gained immense importance in our everyday lifeand is handling each and every aspect of today's technologicalworld. The idea of software at initial phase was implemented bya very precise minority of individual and now it's everywherewhether one's personal life or an organization .Financiallystrong organization and people who can purchase this bounty oftechnological era can fulfill their desires efficiently. For sure it's not a generalized case that one is financially strong and caneasily afford the desired software. There are numerous userswho cannot do so. Open source software has a way out for theseusers it provides them the same facilities and functionalities asin their equivalent software irrespective of any financialpressure. So the financially constrained personals ororganization can make use of open source software forachievement of their desired tasks. In this research paper ananalysis of open source software has been presented byproviding a brief comparison of Ubuntu as an emerging highqu...

  10. Implementing an Open Source Learning Management System: A Critical Analysis of Change Strategies

    Science.gov (United States)

    Uys, Philip M.

    2010-01-01

    This paper analyses the change and innovation strategies that Charles Sturt University (CSU) used from 2007 to 2009 during the implementation and mainstreaming of an open source learning management system (LMS), Sakai, named locally as "CSU Interact". CSU was in January 2008 the first Australian University to implement an open source…

  11. Implementing an Open Source Learning Management System: A Critical Analysis of Change Strategies

    Science.gov (United States)

    Uys, Philip M.

    2010-01-01

    This paper analyses the change and innovation strategies that Charles Sturt University (CSU) used from 2007 to 2009 during the implementation and mainstreaming of an open source learning management system (LMS), Sakai, named locally as "CSU Interact". CSU was in January 2008 the first Australian University to implement an open source…

  12. Chemiluminescence and Bioluminescence as an Excitation Source in the Photodynamic Therapy of Cancer: A Critical Review.

    Science.gov (United States)

    Magalhães, Carla M; Esteves da Silva, Joaquim C G; Pinto da Silva, Luís

    2016-08-04

    Photodynamic therapy (PDT) of cancer is known for its limited number of side effects, and requires light, oxygen and photosensitizer. However, PDT is limited by poor penetration of light into deeply localized tissues, and the use of external light sources is required. Thus, researchers have been studying ways to improve the effectiveness of this phototherapy and expand it for the treatment of the deepest cancers, by using chemiluminescent or bioluminescent formulations to excite the photosensitizer by intracellular generation of light. The aim of this Minireview is to give a précis of the most important general chemi-/bioluminescence mechanisms and to analyze several studies that apply them for PDT. These studies have demonstrated the potential of utilizing chemi-/bioluminescence as excitation source in the PDT of cancer, besides combining new approaches to overcome the limitations of this mode of treatment.

  13. The determination of the kinetic parameters of electrochemical reaction in chemical power sources: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yanhui; Wu, Jun; Li, Decheng; Zheng, Junwei [The Institute of Chemical Power Sources, Soochow (Suzhou) University, Suzhou 215006 (China); Chen, Ying [Max-Planck-Institut fuer Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Duesseldorf (Germany); Ju, Hua [School of Urban Rail Transportation, Soochow (Suzhou) University, Ganjiang East Road 178, Suzhou 215021 (China)

    2010-06-15

    The derivation and proposal of major electrochemical techniques used to determine and calculate the electrochemical kinetic parameters is basically based on the electrochemical reaction taking place at liquid/solid or liquid/liquid interface in which all the reactants and products are soluble in liquid aqueous solution or liquid mercury electrode, or are volatile gas. Such electrochemical reaction system is classical and traditional (ERS1). Recently, the electrochemical behavior of some materials used as the active electrode materials in chemical power sources has attracted much attention. In chemical power source systems, either reactant or product, or both are insoluble. This kind of electrochemical reaction system (ERS2) is slightly different from ERS1. The application of these electrochemical techniques/equations to chemical power sources' system requires carefulness. The misuse of these electrochemical techniques can be easily found in the literatures and some of them even lead to a wrong conclusion. In this review, almost all the electrochemical techniques to measure the exchange current and diffusion coefficient were compiled for reference to the readers, including pulse step, electrochemical impedance, alternating cyclic voltammetry, etc. The necessary requirements/conditions to apply these techniques have been briefly discussed and some simple examples were also discussed for a better understanding. (author)

  14. Critical Quality Source Diagnosis for Dam Concrete Construction Based on Quality Gain-loss Function

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2014-06-01

    Full Text Available In dam concrete construction process, it not only has quality loss arising from quality fluctuation, but also gains quality compensation effect due to the mutual cooperation and adaptation coupling between working procedures (WPs. The calculation and transmission complexity of the quality loss and quality compensation affect the quality management of dam concrete construction. As the quality compensation effect existing in the production practice cannot be described by Taguchi quality loss function, the concept of quality gain-loss function was presented in this paper, which was based on endowing the constant term in the expansion of Taylor series with physical meaning—quality compensation. Based on quality gain-loss function theory, a new quality gain-loss transmission model of dam concrete construction based on GERT network was constructed and its effective algorithm was designed. WP quality gain-loss and its impact on the final product were reasonably measured, and the critical quality routes and critical quality WPs were detected and diagnosed in dam concrete construction network. Summer temperature-controlled concrete construction in the third phase of Three Gorges Project (TGP was taken as an example to carry out the study, and the calculation results showed the validity and practicability of the presented model and algorithm.

  15. 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.

  16. 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.

  17. A Fusion Neutron Source Driven Sub-Critical Nuclear Energy System: A Way for Early Application of Fusion Technology

    Institute of Scientific and Technical Information of China (English)

    吴宜灿

    2001-01-01

    This paper proposes a sub-critical nuclear energy system driven by fusion neutron source, FDS, which can be used to transmute long-lived radioactive wastes and to produce fissile nuclear fuel as a way for early application of fusion technology. The necessity and feasibility to develop that system in China are illustrated on the basis of prediction of the demand of energy source in the first half of the 21th century, the status of current fission energy supply and the progress in fusion technology in the vorld. The characteristics of fusion neutron driver and the potential for transmutation of long-lived nuclear wastes and breeding of fissile nuclear fuel in a blanket are analyzed. A scenario of development steps is proposed.``

  18. 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

  19. Free living amoebae in water sources of critical units in a tertiary care hospital in India

    Directory of Open Access Journals (Sweden)

    S Khurana

    2015-01-01

    Full Text Available Background: Isolation of free-living amoebae (FLA is reported sparsely from water taps, ventilators, air conditioners, haemodialysis units and dental irrigation systems of hospitals worldwide. Their prevalence in hospital environment especially in wards having immunocompromised patients may pose a risk to this group of susceptible population as they may cause disease themselves or may carry pathogens inside them. No study from India has performed such surveillance. Objective: To evaluate extent of FLA contamination in water sources of bone marrow transplant (BMT intensive care unit (ICU, transplant ICU, haemodialysis unit and high dependency unit in a tertiary care hospital in India. Materials and Methods: A total of hundred samples including fifty each of tap water samples and swabs from mouth of taps used for drinking, bathing and hand washing purposes in these units were collected according to standard procedure. Samples were inoculated onto non-nutrient agar plates at room temperature followed by morphological confirmation. Molecular identification including polymerase chain reaction (PCR and sequencing was performed in culture positive samples. Results: Four tap water samples and ten swab samples showed growth of trophozoites and cyst formation. Morphologically, four amoebae resembled Acanthamoeba spp. which was further confirmed by PCR and sequencing showed them to be of T3 and T4 genotypes. Conclusion: The presence of these FLA in hospital water sources emphasises the urgent need of implementing effective preventive measures. Further studies are required to estimate the true prevalence of FLA in Indian hospitals by taking larger number of samples.

  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. Critical issues with cryogenic water extraction for tracing plant's source water

    Science.gov (United States)

    Orlowski, Natalie; Winkler, Anna; McDonnell, Jeffrey J.; Breuer, Lutz

    2016-04-01

    Numerous scientists and disciplines around the world are applying stable water isotope techniques-, especially in the ecohydrological context. For more than two decades, cryogenic vacuum extraction has been the most widely used method for obtaining water from soils and plant tissues for isotope analysis. Recent findings suggested that cryogenic extraction conditions (extraction time, temperature, vacuum threshold) and physicochemical soil properties considerably affected the extracted soil water isotope results. The key question therefore is: Which soil water pool/s are we actually extracting cryogenically under certain extraction conditions and is this soil water pool the source of plant water uptake? We conducted a greenhouse trial with two different plant species grown on two physicochemically different soils (sandy soil and clayey loam) to test the effects of varying cryogenic extraction conditions and physicochemical soil properties on extracted soil water isotope results. We further aimed to identify the unique soil water isotopic signature which mirrors plant's water source. We sampled root crowns and an aliquot of the first and second soil layer for cryogenic water extraction. To determine the plant water available soil water pool/s, we varied water extraction parameters (time and temperature). Our dual-isotope study showed that physicochemical soil properties (i.e. clay content, pore size) along with extraction parameters lead to isotope fractionation effects of soil water. Extraction temperature and time significantly impacted isotope results of clayey loam samples but no effect could be observed for the sandy soil. In general, for water extracts of both soil types, longer extraction times and higher temperatures resulted in enriched isotopic signatures, although this influence was more pronounced for the clayey loam. Determining ideal soil water extraction parameters to identify plant available soil water pools revealed that extraction settings of 200

  2. 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.

  3. A critical experimental test of synchrotron radiation theory with 3rd generation light source

    Energy Technology Data Exchange (ETDEWEB)

    Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-05-15

    A recent ''beam splitting'' experiment at LCLS apparently demonstrated that after a microbunched electron beam is kicked on a large angle compared to the divergence of the FEL radiation, the microbunching wave front is readjusted along the new direction of motion of the kicked beam. Therefore, coherent radiation from an undulator placed after the kicker is emitted along the kicked direction without suppression. This strong emission of coherent undulator radiation in the kicked direction cannot be explained in the framework of conventional synchrotron radiation theory. In a previous paper we explained this puzzle. We demonstrated that, in accelerator physics, the coupling of fields and particles is based, on the one hand, on the use of results from particle dynamics treated according to the absolute time convention and, on the other hand, on the use of Maxwell equations treated according to the standard (Einstein) synchronization convention. Here lies the misconception which led to the strong qualitative disagreement between theory and experiment. After the ''beam splitting'' experiment at LCLS, it became clear that the conventional theory of synchrotron radiation cannot ensure the correct description of coherent and spontaneous emission from a kicked electron beam, nor the emission from a beam with finite angular divergence, in an undulator or a bending magnet. However, this result requires further experimental confirmation. In this publication we propose an uncomplicated and inexpensive experiment to test synchrotron radiation theory at 3rd generation light sources.

  4. Solid residues from Italian municipal solid waste incinerators: A source for "critical" raw materials.

    Science.gov (United States)

    Funari, Valerio; Braga, Roberto; Bokhari, Syed Nadeem Hussain; Dinelli, Enrico; Meisel, Thomas

    2015-11-01

    The incineration of municipal solid wastes is an important part of the waste management system along with recycling and waste disposal, and the solid residues produced after the thermal process have received attention for environmental concerns and the recovery of valuable metals. This study focuses on the Critical Raw Materials (CRM) content in solid residues from two Italian municipal waste incinerator (MSWI) plants. We sampled untreated bottom ash and fly ash residues, i.e. the two main outputs of common grate-furnace incinerators, and determined their total elemental composition with sensitive analytical techniques such as XRF and ICP-MS. After the removal of a few coarse metallic objects from bottom ashes, the corresponding ICP solutions were obtained using strong digestion methods, to ensure the dissolution of the most refractory components that could host significant amounts of precious metals and CRM. The integration of accurate chemical data with a substance flow analysis, which takes into account the mass balance and uncertainties assessment, indicates that bottom and fly ashes can be considered as a low concentration stream of precious and high-tech metals. The magnesium, copper, antimony and zinc contents are close to the corresponding values of a low-grade ore. The distribution of the elements flow between bottom and fly ash, and within different grain size fractions of bottom ash, is appraised. Most elements are enriched in the bottom ash flow, especially in the fine grained fractions. However, the calculated transfer coefficients indicate that Sb and Zn strongly partition into the fly ashes. The comparison with available studies indicates that the CRM concentrations in the untreated solid residues are comparable with those residues that undergo post-treatment beneficiations, e.g. separation between ferrous and non-ferrous fractions. The suggested separate collection of "fresh" bottom ash, which could be processed for further mineral upgrading, can

  5. Family sources of educational gender inequality in rural china: A critical assessment

    Science.gov (United States)

    Hannum, Emily; Kong, Peggy; Zhang, Yuping

    2009-01-01

    more dedication-an attribute parents perceived as being critical for educational success. Findings suggest that at least in Gansu, rural parental educational attitudes and practices toward boys and girls are more complicated and less uniformly negative for girls than commonly portrayed. PMID:20161037

  6. 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....

  7. 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

  8. 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....

  9. Validation of multigroup neutron cross sections and calculational methods for the advanced neutron source against the FOEHN critical experiments measurements

    Energy Technology Data Exchange (ETDEWEB)

    Smith, L.A.; Gallmeier, F.X. [Oak Ridge Institute for Science and Energy, TN (United States); Gehin, J.C. [Oak Ridge National Lab., TN (United States)] [and others

    1995-05-01

    The FOEHN critical experiment was analyzed to validate the use of multigroup cross sections and Oak Ridge National Laboratory neutronics computer codes in the design of the Advanced Neutron Source. The ANSL-V 99-group master cross section library was used for all the calculations. Three different critical configurations were evaluated using the multigroup KENO Monte Carlo transport code, the multigroup DORT discrete ordinates transport code, and the multigroup diffusion theory code VENTURE. The simple configuration consists of only the fuel and control elements with the heavy water reflector. The intermediate configuration includes boron endplates at the upper and lower edges of the fuel element. The complex configuration includes both the boron endplates and components in the reflector. Cross sections were processed using modules from the AMPX system. Both 99-group and 20-group cross sections were created and used in two-dimensional models of the FOEHN experiment. KENO calculations were performed using both 99-group and 20-group cross sections. The DORT and VENTURE calculations were performed using 20-group cross sections. Because the simple and intermediate configurations are azimuthally symmetric, these configurations can be explicitly modeled in R-Z geometry. Since the reflector components cannot be modeled explicitly using the current versions of these codes, three reflector component homogenization schemes were developed and evaluated for the complex configuration. Power density distributions were calculated with KENO using 99-group cross sections and with DORT and VENTURE using 20-group cross sections. The average differences between the measured values and the values calculated with the different computer codes range from 2.45 to 5.74%. The maximum differences between the measured and calculated thermal flux values for the simple and intermediate configurations are {approx} 13%, while the average differences are < 8%.

  10. Critical sources of bacterial contamination and adoption of standard sanitary protocol during semen collection and processing in Semen Station

    Directory of Open Access Journals (Sweden)

    Chandrahas Sannat

    2015-05-01

    Full Text Available Aim: The present investigation was conducted to locate the critical sources of bacterial contamination and to evaluate the standard sanitation protocol so as to improve the hygienic conditions during collection, evaluation, and processing of bull semen in the Semen Station. Materials and Methods: The study compared two different hygienic procedures during the collection, evaluation and processing of semen in Central Semen Station, Anjora, Durg. Routinely used materials including artificial vagina (AV inner liner, cone, semen collection tube, buffer, extender/diluter, straws; and the laboratory environment like processing lab, pass box and laminar air flow (LAF cabinet of extender preparation lab, processing lab, sealing filling machine, and bacteriological lab were subjected to bacteriological examination in two phases of study using two different sanitary protocols. Bacterial load in above items/environment was measured using standard plate count method and expressed as colony forming unit (CFU. Results: Bacterial load in a laboratory environment and AV equipments during two different sanitary protocol in present investigation differed highly significantly (p<0.001. Potential sources of bacterial contamination during semen collection and processing included laboratory environment like processing lab, pass box, and LAF cabinets; AV equipments, including AV Liner and cone. Bacterial load was reduced highly significantly (p<0.001 in AV liner (from 2.33±0.67 to 0.50±0.52, cone (from 4.16±1.20 to 1.91±0.55, and extender (from 1.33±0.38 to 0 after application of improved practices of packaging, handling, and sterilization in Phase II of study. Glasswares, buffers, and straws showed nil bacterial contamination in both the phases of study. With slight modification in fumigation protocol (formalin @600 ml/1000 ft3, bacterial load was significantly decreased (p<0.001 up to 0-6 CFU in processing lab (from 6.43±1.34 to 2.86±0.59, pass box (from 12

  11. 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.

  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. 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...

  14. 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...

  15. 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 ...

  16. 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.

  17. Identifying hydrologically sensitive areas using LiDAR DEMs to mitigate critical source areas of diffuse pollution: development and application

    Science.gov (United States)

    Thomas, Ian; Jordan, Phil; Mellander, Per-Erik; Fenton, Owen; Shine, Oliver; hUallacháin, Daire Ó.; Creamer, Rachel; McDonald, Noeleen; Dunlop, Paul; Murphy, Paul

    2016-04-01

    Identifying critical source areas (CSAs) of diffuse pollution in agricultural catchments requires the accurate identification of hydrologically sensitive areas (HSAs) at highest propensity for generating surface runoff and transporting pollutants such as phosphorus (P). A new GIS-based HSA Index is presented that identifies HSAs at the sub-field scale. It uses a soil topographic index (STI) and accounts for the hydrological disconnection of overland flow via topographic impediment from flow sinks such as hedgerows and depressions. High resolution (0.25-2 m) LiDAR Digital Elevation Models (DEMs) are utilised to capture these microtopographic controls on flow pathways and hydrological connectivity. The HSA Index was applied to four agricultural catchments (~7.5-12 km2) with contrasting topography and soil types. Catchment HSA sizes were estimated using high resolution rainfall-quickflow measurements during saturated winter storm events in 2009-2014, and mapped using the HSA Index. HSA sizes ranged from 1.6-3.4% of the catchment area during median storm events and 2.9-8.5% during upper quartile events depending on whether well or poorly drained soils dominated, which validated HSA Index value distributions. Total flow sink volume capacities ranged from 8,298-59,584 m3 and caused 8.5-24.2% of overland-flow-generating-areas and 16.8-33.4% of catchment areas to become hydrologically disconnected from the open drainage channel network. HSA maps identified 'delivery points' along surface runoff pathways where transported pollutants such as P are delivered to the open drainage network. Using these as proposed locations for targeting mitigation measures such as riparian buffer strips (RBS) reduced costs compared to blanket implementation within an example agri-environment scheme by 66% and 91% over 1 and 5 years respectively, which included LiDAR DEM acquisition costs. Considering that HSAs are often the dominant P CSA factor in agricultural catchments and can override

  18. A critical source area phosphorus index with topographic transport factors using high resolution LiDAR digital elevation models

    Science.gov (United States)

    Thomas, Ian; Murphy, Paul; Fenton, Owen; Shine, Oliver; Mellander, Per-Erik; Dunlop, Paul; Jordan, Phil

    2015-04-01

    A new phosphorus index (PI) tool is presented which aims to improve the identification of critical source areas (CSAs) of phosphorus (P) losses from agricultural land to surface waters. In a novel approach, the PI incorporates topographic indices rather than watercourse proximity as proxies for runoff risk, to account for the dominant control of topography on runoff-generating areas and P transport pathways. Runoff propensity and hydrological connectivity are modelled using the Topographic Wetness Index (TWI) and Network Index (NI) respectively, utilising high resolution digital elevation models (DEMs) derived from Light Detection and Ranging (LiDAR) to capture the influence of micro-topographic features on runoff pathways. Additionally, the PI attempts to improve risk estimates of particulate P losses by incorporating an erosion factor that accounts for fine-scale topographic variability within fields. Erosion risk is modelled using the Unit Stream Power Erosion Deposition (USPED) model, which integrates DEM-derived upslope contributing area and Universal Soil Loss Equation (USLE) factors. The PI was developed using field, sub-field and sub-catchment scale datasets of P source, mobilisation and transport factors, for four intensive agricultural catchments in Ireland representing different agri-environmental conditions. Datasets included soil test P concentrations, degree of P saturation, soil attributes, land use, artificial subsurface drainage locations, and 2 m resolution LiDAR DEMs resampled from 0.25 m resolution data. All factor datasets were integrated within a Geographical Information System (GIS) and rasterised to 2 m resolution. For each factor, values were categorised and assigned relative risk scores which ranked P loss potential. Total risk scores were calculated for each grid cell using a component formulation, which summed the products of weighted factor risk scores for runoff and erosion pathways. Results showed that the new PI was able to predict

  19. 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.

  20. Critical flow-storm approach to total maximum daily load(TMDL) development: an analytical conceptual model

    Institute of Scientific and Technical Information of China (English)

    Harry X.ZHANG; Shaw L.YU

    2008-01-01

    One of the key challenges in the total max-imum daily load (TMDL) development process is how to define the critical condition for a receiving water-body. The main concern in using a continuous simu-lation approach is the absence of any guarantee that the most critical condition will be captured during the selected representative hydrologic period, given the scar-city of long-term continuous data. The objectives of this paper are to clearly address the critical condition in the TMDL development process and to compare continu-ous and evEnt-based approaches in defining critical con-dition during TMDL development for a waterbody impacted by both point and nonpoint source pollution. A practical, event-based critical flow-storm (CFS) approach was developed to explicitly addresses the crit-ical condition as a combination of a low stream flow and a storm event of a selected magnitude, both having cer-tain frequencies of occurrence. This paper illustrated the CFS concept and provided its theoretical basis using a derived analytical conceptual model. The CFS approach clearly defined a critical condition, obtained reasonable results and could be considered as an alternative method in TMDL development.

  1. An exploratory study for rapid estimation of critical source parameters of great subduction-zone earthquakes in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S. K; Perez-Campos, X, Iglesias, A; Pacheco, J. F [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico D.F. (Mexico)

    2008-10-15

    The rapid and reliable estimation of moment magnitude M{sub w}, location, and size of rupture area, and radiated energy E{sub s} of great Mexican subduction zone earthquakes is critical for a quick assessment of tsunami and/or damage potential of the event and for issuing an early tsunami alert. To accomplish this goal, the Mexican broadband seismic network needs to be supplemented by permanent GPS stations along the Pacific coast, spaced about 65 km apart or less. The data from the GPS network must be transmitted to a central location and processed in near-real time to track the position of the stations. Assuming that this can be implemented, we develop a procedure for near-real time estimation of the critical source parameters. We demonstrate the viability of the procedure by processing near-source GPS data and regional seismograms for the earthquakes of Colima-Jalisco in 1995 (M{sub w}=8.0) and Sumatra-Andaman in 2004 (M{sub w}=9.0-9.3). The procedure yields estimates of M{sub w} and E{sub s} in excellent agreement with those reported from earlier solutions. In the case of the Colima-Jalisco earthquake, the estimated location and size of rupture area agree with that mapped from aftershock locations. Presently, there are 13 permanent GPS stations along the Pacific coast of Mexico with an average spacing of {approx}200 km which operate in an autonomous mode. It is urgent to increase the number of stations to {>=}28 thus decreasing the spacing of stations to {<=}65 km. Data must be transmitted in near-real time to a central station to track the position of the stations, preferably every second. [Spanish] Para una estimacion oportuna del potencial de dano y tsunami asociado a los grandes temblores de subduccion en Mexico, resulta critica la determinacion rapida y confiable de parametros sismologicos como lo son la magnitud de momento (M{sub w}), la energia sismica radiada (E{sub s}) y la localizacion y el tamano de la ruptura. Para alcanzar este objetivo, la red

  2. 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....

  3. 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.

  4. Modified control strategies for critical source area of nitrogen (CSAN) in a typical freeze-thaw watershed

    Science.gov (United States)

    Wei, Peng; Ouyang, Wei; Gao, Xiang; Hao, Fanghua; Hao, Zengchao; Liu, Hongbin

    2017-08-01

    The management of critical source areas of diffuse nitrogen (CSANs) remains challenging in freeze-thaw areas due to the different N loss characteristics in different hydrological conditions and seasons. To address these challenges, a modified strategy was proposed in this study using the Soil and Water Assessment Tool (SWAT) to simulate diffuse N loads in the study catchments. Specifically, the spatial and temporal variations of CSANs caused by differences in precipitation and seasons were considered. In addition, the selection of best management practices (BMPs) was selected according to BMP performance and their seasonal characteristics in diffuse N control. The diffuse N load formed during freeze-thaw seasons accounts for approximately 50% of the annual diffuse N load. The diffuse N load discharged to rivers was higher in wet conditions than dry conditions by 127.4% and 181.5% during freeze-thaw seasons and growing seasons, respectively. The spatial distribution of CSANs was more sensitive to differences between freeze-thaw and growing seasons. Among BMPs, buffer strips (BS), no tillage (NT) and reducing N fertilizer applications (RNFA) all showed differences in their diffuse N removal efficiency under different hydrological conditions and seasons, while reforestation operations were not affected by these factors. The benefit of reforestation operations was lower in flatter areas. When areas with slopes greater than 2 degrees were reforested, the average N removal efficiency of the 1st CSAN could be as high as 82.4%. In the 2nd CSAN, the average N removal efficiency of BS was relatively constant across freeze-thaw seasons. Across growing seasons, the N removal efficiency of BS in wet years was 8%-10% higher than in dry conditions due to the lower percentage of lateral flow. The average N removal efficiency of NT was higher during freeze-thaw seasons and lower during growing seasons with average values of 9.3% and 6.1%, respectively. The N control efficiency of

  5. Georgia Tech Studies of Sub-Critical Advanced Burner Reactors with a D-T Fusion Tokamak Neutron Source for the Transmutation of Spent Nuclear Fuel

    Science.gov (United States)

    Stacey, W. M.

    2009-09-01

    The possibility that a tokamak D-T fusion neutron source, based on ITER physics and technology, could be used to drive sub-critical, fast-spectrum nuclear reactors fueled with the transuranics (TRU) in spent nuclear fuel discharged from conventional nuclear reactors has been investigated at Georgia Tech in a series of studies which are summarized in this paper. It is found that sub-critical operation of such fast transmutation reactors is advantageous in allowing longer fuel residence time, hence greater TRU burnup between fuel reprocessing stages, and in allowing higher TRU loading without compromising safety, relative to what could be achieved in a similar critical transmutation reactor. The required plasma and fusion technology operating parameter range of the fusion neutron source is generally within the anticipated operational range of ITER. The implications of these results for fusion development policy, if they hold up under more extensive and detailed analysis, is that a D-T fusion tokamak neutron source for a sub-critical transmutation reactor, built on the basis of the ITER operating experience, could possibly be a logical next step after ITER on the path to fusion electrical power reactors. At the same time, such an application would allow fusion to contribute to meeting the nation's energy needs at an earlier stage by helping to close the fission reactor nuclear fuel cycle.

  6. A Method for Source-load Allocation of Nutrients in Agricultural Watersheds

    Science.gov (United States)

    Burkart, M. R.; James, D. E.

    2001-12-01

    Identification of pollutant sources is critical to solving water resource contamination problems. Non-point sources of agricultural pollution provide substantial challenges to quantifying and allocating the sources of contaminants to streams. A method is presented for identifying the spatial variability of nitrogen and phosphorus sources and allocating proportional responsibility for source-reduction. The method is applied to data at scales ranging from hydrologic regions (2-digit hydrologic accounting units) of the Mississippi drainage basin to the public land survey grid in two small (14-digit) watersheds. A mass balance of nutrient sources and losses is estimated using georeferenced data derived from national to local digital data bases. Nitrogen excess is estimated by balancing sources associated with inorganic fertilizer, manure, crop fixation, mineralization of organic matter, and atmospheric redeposition of ammonia with losses from crop harvest, plant senescence, denitrification, and volatilization of manure and inorganic fertilizer. Phosphorus sources from inorganic fertilizer and manure are balanced with losses due to crop harvest. Allocation in regional units allows targeting of major pollutant source areas while smaller aggregation areas define greater ranges of source-loads useful for specific allocation. Manure sources control the distribution of excess nutrients at many scales, particularly in watersheds with uniform cropping systems. Absolute values of excess N sources provide substantially different allocation patterns than proportional values of total source-loads. Selection of aggregation scale is critical to source-load allocation needed to define TMDLs, monitor loads, and establish water-quality remediation strategies. >http://www.nstl.gov/pubs/burkart/trends/index.html

  7. Critical review and meta-analysis of ambient particulate matter source apportionment using receptor models in Europe

    Science.gov (United States)

    Belis, C. A.; Karagulian, F.; Larsen, B. R.; Hopke, P. K.

    2013-04-01

    A review was conducted of the published literature on source apportionment of ambient particulate matter (PM) in Europe using receptor models (RMs). Consistent records were identified for source contribution estimates of PM mass concentrations for 272 records and of organic carbon (OC) in PM for 60 records. Over the period 2000-2012, a shift was observed in the use of RMs from principal component analysis, enrichment factors, and classical factor analysis to Positive Matrix Factorization while Chemical Mass Balance is still topical. Following a meta-analysis of the published results, six major source categories for PM were defined that comprise almost all individual sources apportioned in Europe: atmospheric formation of secondary inorganic aerosol (SIA), traffic, re-suspension of crustal/mineral dust, biomass burning, (industrial) point sources, and sea/road salt. For the OC fraction, the three main source categories were: atmospheric formation of secondary organic aerosol, biomass burning, and fossil fuel combustion. The geographical and seasonal variations of these sources are mapped and discussed. A special analysis of PM concentrations that exceed the current European air quality limits indicated SIA and traffic as the most important source categories to target for abatement throughout the year together with biomass burning during the cold season.

  8. Development of a multimedia tutorial to educate how to assess the critical view of safety in laparoscopic cholecystectomy using expert review and crowd-sourcing.

    Science.gov (United States)

    Deal, Shanley B; Stefanidis, Dimitrios; Brunt, L Michael; Alseidi, Adnan

    2017-05-01

    We sought to determine the feasibility of developing a multimedia educational tutorial to teach learners to assess the critical view of safety using input from expert surgeons, non-surgeons and crowd-sourcing. We intended to develop a tutorial that would teach learners how to identify the basic anatomy and physiology of the gallbladder, identify the components of the critical view of safety criteria, and understand its significance for performing a safe gallbladder removal. Using rounds of assessment with experts, laypersons and crowd-workers we developed an educational video with improving comprehension after each round of revision. We demonstrate that the development of a multimedia educational tool to educate learners of various backgrounds is feasible using an iterative review process that incorporates the input of experts and crowd sourcing. When planning the development of an educational tutorial, a step-wise approach as described herein should be considered. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. 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 ...

  10. Does the idea of the Old Testament as a Hellenistic Book prevent source criticism of the Pentateuch?

    DEFF Research Database (Denmark)

    Lemche, Niels Peter

    2011-01-01

    It is sometimes maintained that the dating of the Old Testament to the Hellenistic Period precludes any serious critical analysis of, in this case, the Pentateuchal narrative. It is my intent in this paper to state that this is not the case. On the contrary, the idea of the “Endprodukt” coming from...

  11. Reliable Real-time Calculation of Heart-rate Complexity in Critically Ill Patients Using Multiple Noisy Waveform Sources

    Science.gov (United States)

    2014-01-01

    related metrics for detecting sepsis and multior- gan failure, improvement of HRC calculations may help detect significant changes from baseline values...calculations. Equiva- lence tests between mean HRC values derived from man- ually verified sequences and those derived from automatically detected peaks...assessment of HRC in critically ill patients. Keywords Signal detection analysis Electrocardiography Heart rate Clinical decision support

  12. Using Internet Primary Sources To Teach Critical Thinking Skills in Mathematics. Greenwood Professional Guides in School Librarianship.

    Science.gov (United States)

    Glazer, Evan

    This resource book, written for mathematics teachers and school library media specialists, provides Web resources that promote critical thinking in the high school mathematics classroom. It consists of 153 activities that address topics in prealgebra, algebra, geometry, precalculus, calculus, probability, and statistics. Each activity has a…

  13. Biotechnologies for critical raw material recovery from primary and secondary sources: R&D priorities and future perspectives

    NARCIS (Netherlands)

    Hennebel, T.; Boon, N.; Maes, S.; Lenz, M.

    2015-01-01

    Europe is confronted with an increasing supply risk of critical raw materials. These can be defined as materials of which the risks of supply shortage and their impacts on the economy are higher compared to most of other raw materials. Within the framework of the EU Innovation Partnership on raw mat

  14. Biotechnologies for critical raw material recovery from primary and secondary sources: R&D priorities and future perspectives

    NARCIS (Netherlands)

    Hennebel, T.; Boon, N.; Maes, S.; Lenz, M.

    2015-01-01

    Europe is confronted with an increasing supply risk of critical raw materials. These can be defined as materials of which the risks of supply shortage and their impacts on the economy are higher compared to most of other raw materials. Within the framework of the EU Innovation Partnership on raw

  15. Red mud as secondary source for critical raw materials - purification of rare earth elements by liquid/liquid extraction

    NARCIS (Netherlands)

    Ujaczki, Éva; Zimmermann, Yannick; Gasser, Christoph; Molnár, Mónika; Feigl, Viktória; Lenz, Markus

    2017-01-01

    BACKGROUND: Critical raw materials (CRM) are crucial to Europe's economy and essential to maintaining and improving our quality of life due to their usage for production of many devices. Red mud is generated from alumina production where bauxite is digested in hot sodium hydroxide solution during

  16. The generation of gravity-capillary solitary waves by a pressure source moving at a trans-critical speed

    Science.gov (United States)

    Masnadi, Naeem; Duncan, James H.

    2017-01-01

    The unsteady response of a water free surface to a localized pressure source moving at constant speed $U$ in the range $0.95c_\\mathrm{min} \\lesssim U \\leq 1.02 c_\\mathrm{min}$, where $c_\\mathrm{min}$ is the minimum phase speed of linear gravity-capillary waves in deep water, is investigated through experiments and numerical simulations. This unsteady response state, which consists of a V-shaped pattern behind the source and features periodic shedding of pairs of depressions from the tips of the V, was first observed qualitatively by Diorio et al. (Phys. Rev. Let., 103, 214502, 2009) and called state III. In the present investigation, cinematic shadowgraph and refraction-based techniques are utilized to measure the temporal evolution of the free surface deformation pattern downstream of the source as it moves along a towing tank, while numerical simulations of the model equation described by Cho et al. (J. Fluid Mech., 672, 288-306, 2011) are used to extend the experimental results over longer times than are possible in the experiments. From the experiments, it is found that the speed-amplitude characteristics and the shape of the depressions are nearly the same as those of the freely propagating gravity-capillary lumps of inviscid potential theory. The decay rate of the depressions is measured from their height-time characteristics, which are well fitted by an exponential decay law with an order 1 decay constant. It is found that the shedding period of the depression pairs decreases with increasing source strength and speed. As the source speed approaches $c_\\mathrm{min}$, this period tends to about 1~s for all source magnitudes. At the low-speed boundary of state III, a new response with unsteady asymmetric shedding of depressions is found. This response is also predicted by the model equation.

  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. Sources, Methods and Triangulation in Needs Analysis: A Critical Perspective in a Case Study of Waikiki Hotel Maids.

    Science.gov (United States)

    Jasso-Aguilar, Rebeca

    1999-01-01

    This study used qualitative methods, including observation, unstructured interviews, and questionnaires, for analyzing the vocational English-language-instruction needs of hotel maids. Methods and sources (maids, supervisor, executive housekeeper, human resources staff) were triangulated to determine reliability. An unbalanced distribution of…

  19. Critical Jostling

    Directory of Open Access Journals (Sweden)

    Pippin Barr

    2016-11-01

    Full Text Available Games can serve a critical function in many different ways, from serious games about real world subjects to self-reflexive commentaries on the nature of games themselves. In this essay we discuss critical possibilities stemming from the area of critical design, and more specifically Carl DiSalvo’s adversarial design and its concept of reconfiguring the remainder. To illustrate such an approach, we present the design and outcomes of two games, Jostle Bastard and Jostle Parent. We show how the games specifically engage with two previous games, Hotline Miami and Octodad: Dadliest Catch, reconfiguring elements of those games to create interactive critical experiences and extensions of the source material. Through the presentation of specific design concerns and decisions, we provide a grounded illustration of a particular critical function of videogames and hope to highlight this form as another valuable approach in the larger area of videogame criticism.

  20. Design study of a fast spectrum zero-power reactor dedicated to source driven sub-critical experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mercatali, L.; Serikov, A. [Forschungszentrum Karlsruhe, Institute for Neutron Physics and Reactor Technology, P.O. Box 3640, 76021 Karlsruhe (Germany); Baeten, P.; Uyttenhove, W. [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium); Lafuente, A. [Univerisdad Politecnica de Madrid, 28006 Madrid (Spain); Teles, P. [Instituto Tecnologico e Nuclear, EN 10, 2680-953 Sacavem (Portugal)

    2010-09-15

    In the framework of the European P and T program (IFP6-EUROTRANS), the Generation of Uninterrupted Intense NEutrons pulses at the lead VEnus REactor (GUINEVERE) project consists of an Accelerator Driven System (ADS) that is composed by a fast lead simulated-cooled reactor operated in sub-critical conditions, coupled with an updated version of the GENEPI neutron generator previously used for the MUSE experiments. The GUINEVERE facility aims at developing and improving different techniques for the reactivity monitoring of sub-critical ADS's. As such, the GUINEVERE project will comprise a series of major experiments that will be performed in the near future. The GUINEVERE facility will be located at the VENUS light water moderated research reactor at the SCK-CEN site of Mol (Belgium), which needs to be modified in order to accommodate a completely different and new type of core. A series of constraints were taken into account in the technical design of the GUINEVERE core, in order to properly conjugate the technical feasibility of this facility and the necessity to comply with the envisioned experimental program and its associated scientific outcome. The complete design study of the GUINEVERE core is the subject of this paper. The final design of the fuel assemblies, safety and control rods is provided. Also, the critical core configuration, to be used as reference for absolute reactivity measurements, is presented along with its associated reactor physics parameters, calculated by means of Monte Carlo methodologies. Finally, for licensing purposes, the GUINEVERE facility must satisfy the required nuclear safety criteria of the Belgian safety authorities, and in this paper, an overview of the safety analysis that has been performed with regard to the core physics, thermal assessment and shielding issues is also provided. (author)

  1. The Generation of Gravity-Capillary Solitary Waves by a Pressure Source Moving at a Trans-critical Speed

    CERN Document Server

    Masnadi, Naeem

    2016-01-01

    The unsteady response of a water free surface to a localized pressure source moving at constant speed $U$ in the range $0.95c_\\mathrm{min} \\lesssim U \\leq 1.02 c_\\mathrm{min}$, where $c_\\mathrm{min}$ is the minimum phase speed of linear gravity-capillary waves in deep water, is investigated through experiments and numerical simulations. This unsteady response state, which consists of a V-shaped pattern behind the source and features periodic shedding of pairs of depressions from the tips of the V, was first observed qualitatively by Diorio et al. (Phys. Rev. Let., 103, 214502, 2009) and called state III. In the present investigation, cinematic shadowgraph and refraction-based techniques are utilized to measure the temporal evolution of the free surface deformation pattern downstream of the source as it moves along a towing tank, while numerical simulations using the model equation proposed by Cho et al. (J. Fluid Mech., 672, 288-306, 2011) are used to extend the experimental results over longer times than are...

  2. Safety in Serbian animal source food industry and the impact of hazard analysis and critical control points: A review

    Science.gov (United States)

    Tomašević, I.; Đekić, I.

    2017-09-01

    There is a significant lack of HACCP-educated and/or HACCP-highly trained personnel within the Serbian animal source food workforces and veterinary inspectors, and this can present problems, particularly in hazard identification and assessment activities. However, despite obvious difficulties, HACCP benefits to the Serbian dairy industry are widespread and significant. Improving prerequisite programmes on the farms, mainly through infrastructural investments in milk collectors and transportation vehicles on one hand, and increasing hygiene awareness of farmers through training on the other hand has improved the safety of milk. The decline in bacterial numbers on meat contact surfaces, meat handlers’ hands and cooling facilities presents strong evidence of improved process hygiene and justifies the adoption of HACCP in Serbian meat establishments. Apart from the absence of national food poisoning statistics or national foodborne disease databases, the main obstacle to fully recognising the impact of HACCP on the safety of animal source food in Serbia is the lack of research regarding the occurrence of chemical and/or physical hazards interrelated with its production.

  3. 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.

  4. CSER-98-002: Criticality analysis for the storage of special nuclear material sources and standards in the WRAP facility

    Energy Technology Data Exchange (ETDEWEB)

    GOLDBERG, H.J.

    1999-05-18

    The Waste Receiving and Processing (WRAP) Facility will store uranium and transuranic (TRU) sources and standards for certification that WRAP meets the requirements of the Quality Assurance Program Plan (QAPP) for the Waste Isolation Pilot Plant (WIPP). In addition, WRAP must meet internal requirements for testing and validation of measuring instruments for nondestructive assay (NDA). In order to be certified for WIPP, WRAP will participate in the NDA Performance Demonstration Program (PDP). This program is a blind test of the NDA capabilities for TRU waste. It is intended to ensure that the NDA capabilities of this facility satisfy the requirements of the quality assurance program plan for the WIPP. The PDP standards have been provided by the Los Alamos National Laboratory (LANL) for this program. These standards will be used in the WRAP facility.

  5. Critical behaviour of irreversible reaction systems[98.70.Sa Cosmic rays (including sources, origin, acceleration, and interactions);

    Energy Technology Data Exchange (ETDEWEB)

    Loscar, Ernesto; Albano, Ezequiel V [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Sucursal 4, Casilla de Correo 16. (1900) La Plata (Argentina)

    2003-08-01

    An introductory review on the critical behaviour of some irreversible reaction systems is presented. The study of these systems has attracted great attention during the last decades due to, on the one hand, the rich and complex underlying physics, and, on the other, their relevance to numerous technological applications in heterogeneous catalysis, corrosion and coating, development of microelectronic devices, etc. The review focuses on recent advances in the understanding of irreversible phase transitions (IPTs), providing a survey of the theoretical development in the field during the last decade, as well as a detailed discussion of relevant numerical simulations. The Langevin formulation for the treatment of second-order IPTs is discussed. Different Monte Carlo (MC) approaches are also presented in detail and the finite-size-scaling analysis of second-order IPT's is described. Special attention is devoted to the description of the recent progress in the study of first-order IPTs observed upon catalytic oxidation of carbon monoxide and the reduction of nitrogen monoxide, using lattice gas reaction models. Only brief comments are given on other reactions such as the oxidation of hydrogen, ammonia synthesis. Also, a discussion of relevant experiments is presented and measurements are compared with the numerical results. Furthermore, promising areas for further research and open questions are also addressed.

  6. Critical Data Source; Tool or Even Infrastructure? Challenges of Geographic Information Systems and Remote Sensing for Disaster Risk Governance

    Directory of Open Access Journals (Sweden)

    Alexander Fekete

    2015-09-01

    Full Text Available Disaster risk information is spatial in nature and Geographic Information Systems (GIS and Remote Sensing (RS play an important key role by the services they provide to society. In this context, to risk management and governance, in general, and to civil protection, specifically (termed differently in many countries, and includes, for instance: civil contingencies in the UK, homeland security in the USA, disaster risk reduction at the UN level. The main impetus of this article is to summarize key contributions and challenges in utilizing and accepting GIS and RS methods and data for disaster risk governance, which includes public bodies, but also risk managers in industry and practitioners in search and rescue organizations. The article analyzes certain method developments, such as vulnerability indicators, crowdsourcing, and emerging concepts, such as Volunteered Geographic Information, but also investigates the potential of the topic Critical Infrastructure as it could be applied on spatial assets and GIS and RS itself. Intended to stimulate research on new and emerging fields, this article’s main contribution is to move spatial research toward a more reflective stance where opportunities and challenges are equally and transparently addressed in order to gain more scientific quality. As a conclusion, GIS and RS can play a pivotal role not just in delivering data but also in connecting and analyzing data in a more integrative, holistic way.

  7. Characterizing multiple sources and interaction in the critical zone through Sr-isotope tracing of surface and groundwater

    Science.gov (United States)

    Negrel, Philippe; Pauwels, Hélène

    2017-04-01

    The Critical Zone (CZ) is the lithosphere-atmosphere boundary where complex physical, chemical and biological processes occurs and control the transfer and storage of water and chemical elements. This is the place where life-sustaining resources are, where nutrients are being released from the rocks. Because it is the place where we are living, this is a fragile zone, a critical zone as a perturbed natural ecosystem. Water resources in hard-rocks commonly involve different hydrogeological compartments such as overlying sediments, weathered rock, the weathered-fissured zone, and fractured bedrock. Streams, lakes and wetlands that drain such environments can drain groundwater, recharge groundwater, or do both. Groundwater resources in many countries are increasingly threatened by growing demand, wasteful use, and contamination. Surface water and shallow groundwater are particularly vulnerable to pollution, while deeper resources are more protected from contamination. Here, we first report on Sr isotope data as well as major ions, from shallow and deep groundwater in several granite and schist areas over France with intensive agriculture covering large parts of these catchments. In three granite and Brioverian 'schist' areas of the Armorican Massif, the range in Sr contents in groundwater from different catchments agrees with previous work on groundwater sampled from granites in France. The Sr content is well correlated with Mg and both are partly related to agricultural practices and water rock interaction. The relationship between Sr- isotope and Mg/Sr ratios allow defining the different end-members, mainly rain, agricultural practice and water-rock interaction. The data from the Armorican Massif and other surface and groundwater for catchment draining silicate bedrocks (300-450Ma) like the Hérault, Seine, Moselle, Garonne, Morvan, Margeride, Cantal, Pyrénées and Vosges are scattered between at least three geochemical signatures. These include fertilizer and

  8. Bedside functional brain imaging in critically-ill children using high-density EEG source modeling and multi-modal sensory stimulation

    Directory of Open Access Journals (Sweden)

    Danny Eytan

    2016-01-01

    Full Text Available Acute brain injury is a common cause of death and critical illness in children and young adults. Fundamental management focuses on early characterization of the extent of injury and optimizing recovery by preventing secondary damage during the days following the primary injury. Currently, bedside technology for measuring neurological function is mainly limited to using electroencephalography (EEG for detection of seizures and encephalopathic features, and evoked potentials. We present a proof of concept study in patients with acute brain injury in the intensive care setting, featuring a bedside functional imaging set-up designed to map cortical brain activation patterns by combining high density EEG recordings, multi-modal sensory stimulation (auditory, visual, and somatosensory, and EEG source modeling. Use of source-modeling allows for examination of spatiotemporal activation patterns at the cortical region level as opposed to the traditional scalp potential maps. The application of this system in both healthy and brain-injured participants is demonstrated with modality-specific source-reconstructed cortical activation patterns. By combining stimulation obtained with different modalities, most of the cortical surface can be monitored for changes in functional activation without having to physically transport the subject to an imaging suite. The results in patients in an intensive care setting with anatomically well-defined brain lesions suggest a topographic association between their injuries and activation patterns. Moreover, we report the reproducible application of a protocol examining a higher-level cortical processing with an auditory oddball paradigm involving presentation of the patient's own name. This study reports the first successful application of a bedside functional brain mapping tool in the intensive care setting. This application has the potential to provide clinicians with an additional dimension of information to manage

  9. 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...

  10. Small Atomic Orbital Basis Set First-Principles Quantum Chemical Methods for Large Molecular and Periodic Systems: A Critical Analysis of Error Sources.

    Science.gov (United States)

    Sure, Rebecca; Brandenburg, Jan Gerit; Grimme, Stefan

    2016-04-01

    In quantum chemical computations the combination of Hartree-Fock or a density functional theory (DFT) approximation with relatively small atomic orbital basis sets of double-zeta quality is still widely used, for example, in the popular B3LYP/6-31G* approach. In this Review, we critically analyze the two main sources of error in such computations, that is, the basis set superposition error on the one hand and the missing London dispersion interactions on the other. We review various strategies to correct those errors and present exemplary calculations on mainly noncovalently bound systems of widely varying size. Energies and geometries of small dimers, large supramolecular complexes, and molecular crystals are covered. We conclude that it is not justified to rely on fortunate error compensation, as the main inconsistencies can be cured by modern correction schemes which clearly outperform the plain mean-field methods.

  11. Anthropogenic point-source and non-point-source 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.

    2015-07-01

    This study provides a new approach to estimate both anthropogenic non-point-source and point-source 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 water-shed 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-source 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 may influence the extent of export of riverine AN flux from N sources. Our findings highlight the importance of anthropogenic N inputs from both point sources and non-point sources in heavily polluted watersheds, and provide some implications for AN prediction and management.

  12. Continuous 'Passive' Registration of Non-Point Contaminant Loads Via Agricultural Subsurface Drain Tubes

    Science.gov (United States)

    Rozemeijer, J.; Jansen, S.; de Jonge, H.; Lindblad Vendelboe, A.

    2014-12-01

    Considering their crucial role in water and solute transport, enhanced monitoring and modeling of agricultural subsurface tube drain systems is important for adequate water quality management. For example, previous work in lowland agricultural catchments has shown that subsurface tube drain effluent contributed up to 80% of the annual discharge and 90-92% of the annual NO3 loads from agricultural fields towards the surface water. However, existing monitoring techniques for flow and contaminant loads from tube drains are expensive and labor-intensive. Therefore, despite the unambiguous relevance of this transport route, tube drain monitoring data are scarce. The presented study aimed developing a cheap, simple, and robust method to monitor loads from tube drains. We are now ready to introduce the Flowcap that can be attached to the outlet of tube drains and is capable of registering total flow, contaminant loads, and flow-averaged concentrations. The Flowcap builds on the existing SorbiCells, a modern passive sampling technique that measures average concentrations over longer periods of time (days to months) for various substances. By mounting SorbiCells in our Flowcap, a flow-proportional part of the drain effluent is sampled from the main stream. Laboratory testing yielded good linear relations (R-squared of 0.98) between drainage flow rates and sampling rates. The Flowcap was tested in practice for measuring NO3 loads from two agricultural fields and one glasshouse in the Netherlands. The Flowcap registers contaminant loads from tube drains without any need for housing, electricity, or maintenance. This enables large-scale monitoring of non-point contaminant loads via tube drains, which would facilitate the improvement of contaminant transport models and would yield valuable information for the selection and evaluation of mitigation options to improve water quality.

  13. Stream restoration and sewers impact sources and fluxes of water, carbon, and nutrients in urban watersheds

    Science.gov (United States)

    Pennino, Michael J.; Kaushal, Sujay S.; Mayer, Paul M.; Utz, Ryan M.; Cooper, Curtis A.

    2016-08-01

    An improved understanding of sources and timing of water, carbon, and nutrient fluxes associated with urban infrastructure and stream restoration is critical for guiding effective watershed management globally. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P) shift in response to differences in urban stream restoration and sewer infrastructure. We compared an urban restored stream with two urban degraded streams draining varying levels of urban development and one stream with upland stormwater management systems over a 3-year period. We found that there was significantly decreased peak discharge in response to precipitation events following stream restoration. Similarly, we found that the restored stream showed significantly lower (p exported most carbon, nitrogen, and phosphorus at relatively lower streamflow than the two more urban catchments, which exported most carbon and nutrients at higher streamflow. Annual exports of total carbon (6.6 ± 0.5 kg ha-1 yr-1), total nitrogen (4.5 ± 0.3 kg ha-1 yr-1), and total phosphorus (161 ± 15 kg ha-1 yr-1) were significantly lower in the restored stream compared to both urban degraded streams (p exports. However, nitrate isotope data suggested that 55 ± 1 % of the nitrate in the urban restored stream was derived from leaky sanitary sewers (during baseflow), statistically similar to the urban degraded streams. These isotopic results as well as additional tracers, including fluoride (added to drinking water) and iodide (contained in dietary salt), suggested that groundwater contamination was a major source of urban nutrient fluxes, which has been less considered compared to upland sources. Overall, leaking sewer pipes are a problem globally and our results suggest that combining stream restoration with restoration of aging sewer pipes can be critical to more effectively minimizing urban nonpoint nutrient sources. The sources, fluxes, and flowpaths of groundwater

  14. The Hegel's Vorlesungen über die Philosophie der Religion (1821-1831 sources and critical editions from Marheineke to Jaeschke

    Directory of Open Access Journals (Sweden)

    Diego Giordano

    2011-06-01

    Full Text Available In this paper I provide a concise plan about Hegel's Lectures on the Philosophy of Religion critical editions, laying stress on the method followed by editors in order to build a coherent text with the sources at their disposal. The Marheineke's edition (1832 is analysed with special attention since it was the edition that caused the division between a Right and a Left, opening the discussion on speculative theism as a consequence of the difficulty to distinguish the systematic part from the historical one in the reasoning carried out by Hegel.Neste artigo eu ofereço um plano conciso acerca das edições críticas das Preleções sobre a Filosofia da Religião de Hegel enfatizando o método seguido pelos editores com o intuito de construir um texto coerente com as fontes disponíveis para eles. A edição de Marheineke (1832 é analisada com especial atenção dado que ela foi a edição que produziu a divisão entre uma Direita e uma Esquerda, bem como inaugurou a discussão sobre o teísmo especulativo como consequência da dificuldade de se distinguir a parte sistemática da histórica na argumentação desenvolvida por Hegel.

  15. 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.

  16. Use of LANDSAT for Managing Nonpoint Source Pollution in Coastal Ecosystems of the U. S. Virgin Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data results show for the first time Landsat-based land use maps of both the terrestrial and benthic habitats of the U. S. Virgin Islands, spanning a period of...

  17. A combined microscopic and macroscopic approach to modeling the transport of pathogenic microorganisms from nonpoint sources of pollution

    DEFF Research Database (Denmark)

    Yeghiazarian, L.L.; Walker, M.J.; Binning, Philip John

    2006-01-01

    is important for accurate risk assessment and prediction of water contamination events. This paper presents a stochastic Markov model of microorganism transport, with distinct states of microorganism behavior capturing the microbial partitioning between solid and aqueous phases in runoff and soil surface......, including the partitioning among soil particles of various sizes. A connection between the soil sediment and microbial transport is established through the incorporation of an erosion model (WEPP) into the microorganism transport model. Probability distribution functions of microorganism occurrence in time...... results show that areas with clay soils are more likely than sandy soils to contribute to contamination events and that the most influential transport parameters are the saturated hydraulic conductivity, rainfall intensity, and topographic slope....

  18. A repeated-measures study of recreational water exposure, non-point source pollution, and risk of illness

    Science.gov (United States)

    Discharge of stormwater runoff onto beaches is a major cause of beach closings and advisories in the United States. Prospective studies of recreational water quality and health have often been limited to two time points (baseline and follow-up). Little is known about the risk of ...

  19. HYPOXIA IN THE GULF OF MEXICO: ASSESSING AND MANAGING RISKS FROM NONPOINT SOURCE POLLUTANTS IN THE MISSISSIPPI RIVER BASIN

    Science.gov (United States)

    . Hypoxia is the condition in which dissolved oxygen levels are below that necessary to sustain most animal life. The largest zone of oxygen depletion in U.S. coastal waters is found in the northern Gulf of Mexico (NGOM) on the Louisiana/Texas continental shelf. In response to...

  20. HYPOXIA IN THE GULF OF MEXICO: ASSESSING AND MANAGING RISKS FROM NONPOINT SOURCE POLLUTANTS IN THE MISSISSIPPI RIVER BASIN

    Science.gov (United States)

    . Hypoxia is the condition in which dissolved oxygen levels are below that necessary to sustain most animal life. The largest zone of oxygen depletion in U.S. coastal waters is found in the northern Gulf of Mexico (NGOM) on the Louisiana/Texas continental shelf. In response to...

  1. 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.

  2. WA - Impacts of non-point source pollution on the health of salmonids in urban and urbanizing watersheds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — By the Services conducting this off-refuge EC investigation and jointly publishing the results in the two aforementioned manuscripts [see notes section of ProCite...

  3. Modeling hydrology, groundwater recharge and non-point nitrate loadings in the Himalayan Upper Yamuna basin.

    Science.gov (United States)

    Narula, Kapil K; Gosain, A K

    2013-12-01

    The mountainous Himalayan watersheds are important hydrologic systems responsible for much of the water supply in the Indian sub-continent. These watersheds are increasingly facing anthropogenic and climate-related pressures that impact spatial and temporal distribution of water availability. This study evaluates temporal and spatial distribution of water availability including groundwater recharge and quality (non-point nitrate loadings) for a Himalayan watershed, namely, the Upper Yamuna watershed (part of the Ganga River basin). The watershed has an area of 11,600 km(2) with elevation ranging from 6300 to 600 m above mean sea level. Soil and Water Assessment Tool (SWAT), a physically-based, time-continuous model, has been used to simulate the land phase of the hydrological cycle, to obtain streamflows, groundwater recharge, and nitrate (NO3) load distributions in various components of runoff. The hydrological SWAT model is integrated with the MODular finite difference groundwater FLOW model (MODFLOW), and Modular 3-Dimensional Multi-Species Transport model (MT3DMS), to obtain groundwater flow and NO3 transport. Validation of various modules of this integrated model has been done for sub-basins of the Upper Yamuna watershed. Results on surface runoff and groundwater levels obtained as outputs from simulation show a good comparison with the observed streamflows and groundwater levels (Nash-Sutcliffe and R(2) correlations greater than +0.7). Nitrate loading obtained after nitrification, denitrification, and NO3 removal from unsaturated and shallow aquifer zones is combined with groundwater recharge. Results for nitrate modeling in groundwater aquifers are compared with observed NO3 concentration and are found to be in good agreement. The study further evaluates the sensitivity of water availability to climate change. Simulations have been made with the weather inputs of climate change scenarios of A2, B2, and A1B for end of the century. Water yield estimates under

  4. Sources of endocrine-disrupting compounds in North Carolina waterways: a geographic information systems approach.

    Science.gov (United States)

    Sackett, Dana K; Pow, Crystal Lee; Rubino, Matthew J; Aday, D Derek; Cope, W Gregory; Kullman, Seth; Rice, James A; Kwak, Thomas J; Law, Mac

    2015-02-01

    The presence of endocrine-disrupting compounds (EDCs), particularly estrogenic compounds, in the environment has drawn public attention across the globe, yet a clear understanding of the extent and distribution of estrogenic EDCs in surface waters and their relationship to potential sources is lacking. The objective of the present study was to identify and examine the potential input of estrogenic EDC sources in North Carolina water bodies using a geographic information system (GIS) mapping and analysis approach. Existing data from state and federal agencies were used to create point and nonpoint source maps depicting the cumulative contribution of potential sources of estrogenic EDCs to North Carolina surface waters. Water was collected from 33 sites (12 associated with potential point sources, 12 associated with potential nonpoint sources, and 9 reference), to validate the predictive results of the GIS analysis. Estrogenicity (measured as 17β-estradiol equivalence) ranged from 0.06 ng/L to 56.9 ng/L. However, the majority of sites (88%) had water 17β-estradiol concentrations below 1 ng/L. Sites associated with point and nonpoint sources had significantly higher 17β-estradiol levels than reference sites. The results suggested that water 17β-estradiol was reflective of GIS predictions, confirming the relevance of landscape-level influences on water quality and validating the GIS approach to characterize such relationships. © 2014 SETAC.

  5. Sources of endocrine-disrupting compounds in North Carolina waterways: a geographic information systems approach

    Science.gov (United States)

    Sackett, Dana K.; Pow, Crystal Lee; Rubino, Matthew; Aday, D.D.; Cope, W. Gregory; Kullman, Seth W.; Rice, J.A.; Kwak, Thomas J.; Law, L.M.

    2015-01-01

    The presence of endocrine-disrupting compounds (EDCs), particularly estrogenic compounds, in the environment has drawn public attention across the globe, yet a clear understanding of the extent and distribution of estrogenic EDCs in surface waters and their relationship to potential sources is lacking. The objective of the present study was to identify and examine the potential input of estrogenic EDC sources in North Carolina water bodies using a geographic information system (GIS) mapping and analysis approach. Existing data from state and federal agencies were used to create point and nonpoint source maps depicting the cumulative contribution of potential sources of estrogenic EDCs to North Carolina surface waters. Water was collected from 33 sites (12 associated with potential point sources, 12 associated with potential nonpoint sources, and 9 reference), to validate the predictive results of the GIS analysis. Estrogenicity (measured as 17β-estradiol equivalence) ranged from 0.06 ng/L to 56.9 ng/L. However, the majority of sites (88%) had water 17β-estradiol concentrations below 1 ng/L. Sites associated with point and nonpoint sources had significantly higher 17β-estradiol levels than reference sites. The results suggested that water 17β-estradiol was reflective of GIS predictions, confirming the relevance of landscape-level influences on water quality and validating the GIS approach to characterize such relationships.

  6. Spatial Regression and Prediction of Water Quality in a Watershed with Complex Pollution Sources.

    Science.gov (United States)

    Yang, Xiaoying; Liu, Qun; Luo, Xingzhang; Zheng, Zheng

    2017-08-16

    Fast economic development, burgeoning population growth, and rapid urbanization have led to complex pollution sources contributing to water quality deterioration simultaneously in many developing countries including China. This paper explored the use of spatial regression to evaluate the impacts of watershed characteristics on ambient total nitrogen (TN) concentration in a heavily polluted watershed and make predictions across the region. Regression results have confirmed the substantial impact on TN concentration by a variety of point and non-point pollution sources. In addition, spatial regression has yielded better performance than ordinary regression in predicting TN concentrations. Due to its best performance in cross-validation, the river distance based spatial regression model was used to predict TN concentrations across the watershed. The prediction results have revealed a distinct pattern in the spatial distribution of TN concentrations and identified three critical sub-regions in priority for reducing TN loads. Our study results have indicated that spatial regression could potentially serve as an effective tool to facilitate water pollution control in watersheds under diverse physical and socio-economical conditions.

  7. Improving the identification of hydrologically sensitive areas using LiDAR DEMs for the delineation and mitigation of critical source areas of diffuse pollution.

    Science.gov (United States)

    Thomas, I A; Jordan, P; Mellander, P-E; Fenton, O; Shine, O; Ó hUallacháin, D; Creamer, R; McDonald, N T; Dunlop, P; Murphy, P N C

    2016-06-15

    Identifying critical source areas (CSAs) of diffuse pollution in agricultural catchments requires the accurate identification of hydrologically sensitive areas (HSAs) at highest propensity for generating surface runoff and transporting pollutants. A new GIS-based HSA Index is presented that improves the identification of HSAs at the sub-field scale by accounting for microtopographic controls. The Index is based on high resolution LiDAR data and a soil topographic index (STI) and also considers the hydrological disconnection of overland flow via topographic impediment from flow sinks. The HSA Index was applied to four intensive agricultural catchments (~7.5-12km(2)) with contrasting topography and soil types, and validated using rainfall-quickflow measurements during saturated winter storm events in 2009-2014. Total flow sink volume capacities ranged from 8298 to 59,584m(3) and caused 8.5-24.2% of overland-flow-generating-areas and 16.8-33.4% of catchment areas to become hydrologically disconnected from the open drainage channel network. HSA maps identified 'breakthrough points' and 'delivery points' along surface runoff pathways as vulnerable points where diffuse pollutants could be transported between fields or delivered to the open drainage network, respectively. Using these as proposed locations for targeting mitigation measures such as riparian buffer strips reduced potential costs compared to blanket implementation within an example agri-environment scheme by 66% and 91% over 1 and 5years respectively, which included LiDAR DEM acquisition costs. The HSA Index can be used as a hydrologically realistic transport component within a fully evolved sub-field scale CSA model, and can also be used to guide the implementation of 'treatment-train' mitigation strategies concurrent with sustainable agricultural intensification.

  8. Critical review of soil contamination by polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFRs); concentrations, sources and congener profiles.

    Science.gov (United States)

    McGrath, Thomas J; Ball, Andrew S; Clarke, Bradley O

    2017-11-01

    Polybrominated diphenyl ethers (PBDEs) have been used in a broad array of polymeric materials such as plastics, foams, resins and adhesives to inhibit the spread of fires since the 1970s. The widespread environmental contamination and well documented toxic effects of PBDEs have led to bans and voluntary withdrawals in many jurisdictions. Replacement novel brominated flame retardants (NBFRs) have, however, exhibited many of the same toxic characteristics as PBDEs and appear to share similar environmental fate. This paper presents a critical review of the scientific literature regarding PBDE and NBFR contamination of surface soils internationally, with the secondary objective of identifying probable pollution sources. An evaluation of NBFR distribution in soil was also conducted to assess the suitability of the newer compounds as replacements for PBDEs, with respect to their land contamination potential. Principle production of PBDEs and NBFRs and their consequent use in secondary polymer manufacture appear to be processes with strong potential to contaminate surrounding soils. Evidence suggests that PBDEs and NBFRs are also released from flame retarded products during disposal via landfill, dumping, incineration and recycling. While the land application of sewage sludge represents another major pathway of soil contamination it is not considered in this review as it is extensively covered elsewhere. Both PBDEs and NBFRs were commonly detected at background locations including Antarctica and northern polar regions. PBDE congener profiles in soil were broadly representative of the major constituents in Penta-, Octa- and Deca-BDE commercial mixtures and related to predicted market place demand. BDE-209 dominated soil profiles, followed by BDE-99 and BDE-47. Although further research is required to gain baseline data on NBFRs in soil, the current state of scientific literature suggests that NBFRs pose a similar risk to land contamination as PBDEs. Copyright © 2017

  9. Modeling hydrology, groundwater recharge and non-point nitrate loadings in the Himalayan Upper Yamuna basin

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Kapil K., E-mail: kkn2104@columbia.edu [Columbia Water Center (India Office), Columbia University, New Delhi 110 016 (India); Gosain, A.K. [Department of Civil Engineering, Indian Institute of Technology (IIT) Delhi, Hauz Khas, New Delhi 110 016 (India)

    2013-12-01

    The mountainous Himalayan watersheds are important hydrologic systems responsible for much of the water supply in the Indian sub-continent. These watersheds are increasingly facing anthropogenic and climate-related pressures that impact spatial and temporal distribution of water availability. This study evaluates temporal and spatial distribution of water availability including groundwater recharge and quality (non-point nitrate loadings) for a Himalayan watershed, namely, the Upper Yamuna watershed (part of the Ganga River basin). The watershed has an area of 11 600 km{sup 2} with elevation ranging from 6300 to 600 m above mean sea level. Soil and Water Assessment Tool (SWAT), a physically-based, time-continuous model, has been used to simulate the land phase of the hydrological cycle, to obtain streamflows, groundwater recharge, and nitrate (NO{sub 3}) load distributions in various components of runoff. The hydrological SWAT model is integrated with the MODular finite difference groundwater FLOW model (MODFLOW), and Modular 3-Dimensional Multi-Species Transport model (MT3DMS), to obtain groundwater flow and NO{sub 3} transport. Validation of various modules of this integrated model has been done for sub-basins of the Upper Yamuna watershed. Results on surface runoff and groundwater levels obtained as outputs from simulation show a good comparison with the observed streamflows and groundwater levels (Nash–Sutcliffe and R{sup 2} correlations greater than + 0.7). Nitrate loading obtained after nitrification, denitrification, and NO{sub 3} removal from unsaturated and shallow aquifer zones is combined with groundwater recharge. Results for nitrate modeling in groundwater aquifers are compared with observed NO{sub 3} concentration and are found to be in good agreement. The study further evaluates the sensitivity of water availability to climate change. Simulations have been made with the weather inputs of climate change scenarios of A2, B2, and A1B for end of the

  10. 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.

  11. 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.

  12. CriticalEd

    DEFF Research Database (Denmark)

    Kjellberg, Caspar Mølholt; Meredith, David

    2014-01-01

    The best text method is commonly applied among music scholars engaged in producing critical editions. In this method, a comment list is compiled, consisting of variant readings and editorial emendations. This list is maintained by inserting the comments into a document as the changes are made....... Since the comments are not input sequentially, with regard to position, but in arbitrary order, this list must be sorted by copy/pasting the rows into place—an error-prone and time-consuming process. Scholars who produce critical editions typically use off-the-shelf music notation software...... such as Sibelius or Finale. It was hypothesized that it would be possible to develop a Sibelius plug-in, written in Manuscript 6, that would improve the critical editing work flow, but it was found that the capabilities of this scripting language were insufficient. Instead, a 3-part system was designed and built...

  13. When Do Students “Learn-to-Comprehend” Scientific Sources?: Evaluation of a Critical Skill in Undergraduates Progressing through a Science Major

    National Research Council Canada - National Science Library

    Marsh, Tamara L; Guenther, Merrilee F; Raimondi, Stacey L

    2015-01-01

    ... writing assignments in every course. One commonality among all of the assignments is the ability to comprehend and critically evaluate scientific literature to determine relevancy and possible future research...

  14. When Do Students "Learn-to-Comprehend" Scientific Sources?: Evaluation of a Critical Skill in Undergraduates Progressing through a Science Major

    National Research Council Canada - National Science Library

    Marsh, Tamara L; Guenther, Merrilee F; Raimondi, Stacey L

    2015-01-01

    ... writing assignments in every course. One commonality among all of the assignments is the ability to comprehend and critically evaluate scientific literature to determine relevancy and possible future research...

  15. Distribution and Sources of Nitrate-Nitrogen in Kansas Groundwater

    Directory of Open Access Journals (Sweden)

    Margaret A. Townsend

    2001-01-01

    Full Text Available Kansas is primarily an agricultural state. Irrigation water and fertilizer use data show long- term increasing trends. Similarly, nitrate-N concentrations in groundwater show long-term increases and exceed the drinking-water standard of 10 mg/l in many areas. A statistical analysis of nitrate-N data collected for local and regional studies in Kansas from 1990 to 1998 (747 samples found significant relationships between nitrate-N concentration with depth, age, and geographic location of wells. Sources of nitrate-N have been identified for 297 water samples by using nitrogen stable isotopes. Of these samples, 48% showed fertilizer sources (+2 to +8 and 34% showed either animal waste sources (+10 to +15 with nitrate-N greater than 10 mg/l or indication that enrichment processes had occurred (+10 or above with variable nitrate-N or both. Ultimate sources for nitrate include nonpoint sources associated with past farming and fertilization practices, and point sources such as animal feed lots, septic systems, and commercial fertilizer storage units. Detection of nitrate from various sources in aquifers of different depths in geographically varied areas of the state indicates that nonpoint and point sources currently impact and will continue to impact groundwater under current land uses.

  16. Enthusiastic, realistic and critical: discourses of Internet use in the context of everyday life information seeking Internet, Everyday life, Information seeking, Discourse analysis, Interpretative repertoires, Information sources, Value, Use

    Directory of Open Access Journals (Sweden)

    Reijo Savolainen

    2004-01-01

    Full Text Available Based on the interviews of 18 participants, the ways in which people talk about their source preferences with regard to the Internet in everyday life information seeking were investigated by using discourse analysis. Three major interpretative repertoires were identified: Enthusiastic, Realistic and Critical. The Enthusiastic repertoire emphasizes the strengths of the Internet, conceiving it as a 'great enabler' or as a 'technology of freedom'. In this repertoire, positive expressions such as fast, easy and interactive are favoured. In the Realistic repertoire, the source preferences are constructed as situation-bound choices. The Internet is given no absolute priority but its value is seen to depend on the relative advantages in specific situations. No sources or channels are superior by themselves but their value is contingent on the use situation and its specific requirements. Finally, the Critical repertoire is characterized by a reserved standpoint to the advantages brought by the Internet. Central to this repertoire is the critical view on the low amount of relevant informationavailable in the Internet and the poor organization of networked information, rendering effective information seeking difficult. Due to their ideal-typical nature, the above repertoires are rather independent. However, in the everyday discursive practices, the repertoires are used alternately, and the same speaker may shift from one repertoire to another within the same account.

  17. When Do Students "Learn-to-Comprehend" Scientific Sources?: Evaluation of a Critical Skill in Undergraduates Progressing through a Science Major.

    Science.gov (United States)

    Marsh, Tamara L; Guenther, Merrilee F; Raimondi, Stacey L

    2015-05-01

    In response to the publication of Vision and Change, the biology department at Elmhurst College revised our curriculum to better prepare students for a career in science with the addition of various writing assignments in every course. One commonality among all of the assignments is the ability to comprehend and critically evaluate scientific literature to determine relevancy and possible future research. Several previous reports have analyzed specific methodologies to improve student comprehension of scientific writing and critical thinking skills, yet none of these examined student growth over an undergraduate career. In this study, we hypothesized upper-level students would be better able to comprehend and critically analyze scientific literature than introductory biology majors. Biology students enrolled in an introductory (200-level), mid- (300-level), or late-career (400-level) course were tasked with reading and responding to questions regarding a common scientific article and rating their comfort and confidence in reading published literature. As predicted, upper-level (mid- and late-career) students showed increases in comprehension and critical analysis relative to their first-year peers. Interestingly, we observed that upper-level students read articles differently than introductory students, leading to significant gains in understanding and confidence. However, the observed gains were modest overall, indicating that further pedagogical change is necessary to improve student skills and confidence in reading scientific articles while fulfilling the Vision and Change recommendations.

  18. When Do Students “Learn-to-Comprehend” Scientific Sources?: Evaluation of a Critical Skill in Undergraduates Progressing through a Science Major

    Directory of Open Access Journals (Sweden)

    Tamara L. Marsh

    2015-02-01

    Full Text Available In response to the publication of Vision and Change, the biology department at Elmhurst College revised our curriculum to better prepare students for a career in science with the addition of various writing assignments in every course. One commonality among all of the assignments is the ability to comprehend and critically evaluate scientific literature to determine relevancy and possible future research. Several previous reports have analyzed specific methodologies to improve student comprehension of scientific writing and critical thinking skills, yet none of these examined student growth over an undergraduate career. In this study, we hypothesized upper-level students would be better able to comprehend and critically analyze scientific literature than introductory biology majors. Biology students enrolled in an introductory (200-level, mid- (300-level, or late-career (400-level course were tasked with reading and responding to questions regarding a common scientific article and rating their comfort and confidence in reading published literature. As predicted, upper-level (mid- and late-career students showed increases in comprehension and critical analysis relative to their first-year peers. Interestingly, we observed that upper-level students read articles differently than introductory students, leading to significant gains in understanding and confidence. However, the observed gains were modest overall, indicating that further pedagogical change is necessary to improve student skills and confidence in reading scientific articles while fulfilling the Vision and Change recommendations.

  19. 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。

  20. Examining trends in general fecal indicator bacteria and microbial source tracking genetic markers at non-point source impacted Chicago beaches

    Science.gov (United States)

    In the Chicago area, treated wastewater and storm water flow through the engineered Chicago River system to the Mississippi River, with the goal to protect Lake Michigan from urban discharges. Therefore, under dry weather conditions, nearby Lake Michigan recreational beaches shou...

  1. Regulation og non-point phosphorus emissions from the agricultural sector by use of economic incentives

    DEFF Research Database (Denmark)

    Hansen, Line Block

    . Once a soil is highly enriched it will become a significant source of P losses for a long time. In Denmark, application of manure is primarily determined by nitrogen (N) crop nutrition, implying that livestock farmers are not motivated to further reduce their surplus P applications. The high costs...

  2. On the response of a water surface to a surface pressure source moving at trans-critical gravity-capillary wave speeds

    Science.gov (United States)

    Masnadi, Naeem; Cho, Yeunwoo; Duncan, James H.; Akylas, Triantaphyllos

    2015-11-01

    The non-linear response of a water free surface to a pressure source moving at speeds near the minimum speed of linear gravity-capillary waves (Cmin ~ 23 cm/s) is investigated with experiments and theory. In the experiments, waves are generated by a vertically oriented air-jet that moves at a constant speed over the water surface in a long tank. The 3-D surface shape behind the air-jet is measured using a cinematic refraction-based technique combined with an LIF technique. At towing speeds just below Cmin, an unsteady pattern is formed where localized depressions periodically appear in pairs and move away from the source along the arms of a downstream V-shaped pattern. This behavior is analogous to the periodic shedding of solitary waves upstream of a source moving at the maximum wave speed in shallow water. The gravity-capillary depressions are rapidly damped by viscosity and their speed-amplitude characteristics closely match those from inviscid calculations of gravity-capillary lumps. The shedding frequency of the lumps in the present experiments increases with both increasing towing speed and air-flow rate. Predictions of this behavior using a model equation that incorporates damping and a quadratic nonlinearity are in good agreement with the experiments. The partial support of the National Science Foundation under grant OCE0751853 is gratefully acknowledged.

  3. The use of sub-critical water hydrolysis for the recovery of peptides and free amino acids from food processing wastes. Review of sources and main parameters.

    Science.gov (United States)

    Marcet, Ismael; Álvarez, Carlos; Paredes, Benjamín; Díaz, Mario

    2016-03-01

    Food industry processing wastes are produced in enormous amounts every year, such wastes are usually disposed with the corresponding economical cost it implies, in the best scenario they can be used for pet food or composting. However new promising technologies and tools have been developed in the last years aimed at recovering valuable compounds from this type of materials. In particular, sub-critical water hydrolysis (SWH) has been revealed as an interesting way for recovering high added-value molecules, and its applications have been broadly referred in the bibliography. Special interest has been focused on recovering protein hydrolysates in form of peptides or amino acids, from both animal and vegetable wastes, by means of SWH. These recovered biomolecules have a capital importance in fields such as biotechnology research, nutraceuticals, and above all in food industry, where such products can be applied with very different objectives. Present work reviews the current state of art of using sub-critical water hydrolysis for protein recovering from food industry wastes. Key parameters as reaction time, temperature, amino acid degradation and kinetic constants have been discussed. Besides, the characteristics of the raw material and the type of products that can be obtained depending on the substrate have been reviewed. Finally, the application of these hydrolysates based on their functional properties and antioxidant activity is described.

  4. [Source apportionment of dioxin-like polychlorinated biphenyls in soil of the modern Yellow River Delta].

    Science.gov (United States)

    Liu, Jing; Cui, Zhao-jie; Fan, Guo-lan; Xu, Hong-yu

    2007-12-01

    The concentrations of 12 dioxin-like polychlorinated biphenyls (PCBs) in twenty two soil samples collected from modern Yellow River Delta were determined by dual capillary GC-ECD associated with GC-MS. Principle component analysis (PCA) was applied in analysing the dioxin-like PCBs data to obtain types, sources, percentages of source contribution and the congener composition of PCBs in the Delta on the congener level. The results indicated that four types of PCBs contamination sources affecting the PCBs distribution pattern were apportioned in the Delta. The first source was water runoff (non-point source), which was from the industrial production and use by the enterprises along the Yellow River, and it contributed 49.6% of the total contamination burden in the Delta, its dioxin-like PCBs profile was similar to native PCBs and Aroclorl221; the second and third types of PCBs sources were point sources, whose percentages of contribution were 15.0% and 10.1% respectively, the composition of the second source was similar to that of Aroclor1221 and Aroclor1242, the composition of the third source was similar to that of Aroclor1260; the fourth source is believed to be non-point source which was from the atmospheric dry and wet precipitation, it contributed 8.4%, its profile have similarity composition of the integration of Aroclor1242, Aroclor1248 and Aroclor1260.

  5. Thinking Critically about Critical Thinking

    Science.gov (United States)

    Mulnix, Jennifer Wilson

    2012-01-01

    As a philosophy professor, one of my central goals is to teach students to think critically. However, one difficulty with determining whether critical thinking can be taught, or even measured, is that there is widespread disagreement over what critical thinking actually is. Here, I reflect on several conceptions of critical thinking, subjecting…

  6. 论文学空间批评的美学源流%On the aesthetic sources of literary spatial criticism

    Institute of Scientific and Technical Information of China (English)

    王影君

    2014-01-01

    文学空间批评的美学源流历史久远,从希腊古典主义的柏拉图到文艺复兴后的莱辛,到俄国形式主义的巴赫金,再到德国法兰克福学派的本雅明,他们都在不同历史时期为文学空间批评做出了独特的美学贡献。正是借助于诸多的美学源流,并在马克思基本理论基础上,马克思主义都市空间美学才能最终兴起,其代表人物列斐伏尔、福柯和哈维等人引领了空间转向,继而文学中的空间叙事和都市研究引起公众注意,出现所谓的空间批评“新”象。因此,文学的空间批评是空间美学长期发展的历史性成果。%The literary spatial criticism has a quite long history of aesthetics. From Greek Plato, to Lessing who lived after the Renaissance, to Bakhtin, a famous Russian formalist, to Benjamin an early Frankfurt Scholar, all of them devoted their particular achievements to the basic aesthetic theory of literary spatial criticism. Deriving from so many persons’ thoughts of the aesthetic theory and based on Marx’s basic spatial idea, the Marxist urban aesthetics made its great building. Then under the leadership of Lefebvre, Foucault and Harvey, the spatial turning happened. Following the spatial turning, the literary spatial narration and the urban study attracted the public notice as a “new” tide. Thus, the literary spatial criticism is a result of the long development in the history of spatial aesthetics.

  7. Critical stenosis of a right ventricle to coronary artery fistula seen at dual-source CT in a newborn with pulmonary atresia and intact ventricular septum.

    Science.gov (United States)

    Séguéla, Pierre-Emmanuel; Houyel, Lucile; Loget, Philippe; Piot, Jean-Dominique; Paul, Jean-François

    2011-08-01

    We report the case of a newborn with pulmonary atresia with intact ventricular septum and right ventricle-dependent coronary circulation. He died several weeks after a Blalock-Taussig procedure because of a progressive stenosis of the main coronary artery. We present echocardiographic and dual-source CT images of the stenosis, with autopsy correlation. To our knowledge, CT images of this quality have never been reported in a newborn. This case illustrates the extreme difficulty in prognosticating the outcome for these patients and underlines the need for a detailed neonatal coronary mapping to assess right ventricle-dependent coronary circulation.

  8. Regulation og non-point phosphorus emissions from the agricultural sector by use of economic incentives

    DEFF Research Database (Denmark)

    Hansen, Line Block

    in the effort to reduce agricultural P runoff. Continued application of P in excess of crop requirements causes P stocks to build up in fields and, over time, this increases the risk of losing P to the aquatic environment through surface runoff and erosion and through leaching via the soil matrix or macropores...... of transporting and applying manure to fields means that increasing mineral-fertilizer prices does not generate a sufficient incentive for farmers to reallocate all P surpluses generated by livestock between farms and fields. The aim of the thesis is to increase the understanding of the long-term impacts....... Once a soil is highly enriched it will become a significant source of P losses for a long time. In Denmark, application of manure is primarily determined by nitrogen (N) crop nutrition, implying that livestock farmers are not motivated to further reduce their surplus P applications. The high costs...

  9. Critical Care

    Science.gov (United States)

    Critical care helps people with life-threatening injuries and illnesses. It might treat problems such as complications ... a team of specially-trained health care providers. Critical care usually takes place in an intensive care ...

  10. The non-point output of different agriculture landuse types in Zhexi hydraulic region of Taihu Basin

    Institute of Scientific and Technical Information of China (English)

    LIHengpeng; LIUXiaomei; HUANGWenyu

    2004-01-01

    This paper takes Zhexi hydraulic region in Taihu Basin as a study area. On the basis of hydraulic analysis function of Arcgis8.3, the drainages were delineated by selecting the monitoring points and discharge stations as outlets. The landuse map were finished by denoting the TM/ETM image. The precipitation map was finished by spatial interpolation according to the rainfall monitoring records. Overlaying the drainage boundary, landuse map and precipitation map, the rainfall, different landuse type area, and runoff pollution concentration and runoff were calculated. Based on these data in different sub-watersheds, by Origin7.0 regression tool, an equation is established to predict runoff using the relationships between runoff, precipitation depth and land use patterns in each of the sub-watersheds. Selecting the sub-watershed which is mainly composed of forest landuse type, the mean runoff concentration (MRC) from sub-watershed has been estimated. The mean runoff concentration of farmland has been estimated by the same methods after the contribution of forestlanduse type was removed. The results are" for the forest landuse type, the mean runoff concentrationsof COD, BOD, Total N and Total P are 2.95 mg/l, 1.080 mg/l, 0.715 mg/l, and 0.039 mg/l,respectively; for the farmland, the mean runoff concentrations of COD, BOD, Total N and Total P are 5.721 rag/l, 3.097 rag/l, 2.092 rag/l, and 0.166 rag/l, respectively. By using these results, the agriculture non-point pollution loads have been assessed. The loads of COD, BOD, Total N and Total P in Zhexi region are 14,631.69 t/a, 6401.93 t/a, 4281.753 t/a and 287.67 t/a, respectively.

  11. Archetypal Criticism.

    Science.gov (United States)

    Chesebro, James W.; And Others

    1990-01-01

    Argues that archetypal criticism is a useful way of examining universal, historical, and cross-cultural symbols in classrooms. Identifies essential features of an archetype; outlines operational and critical procedures; illustrates archetypal criticism as applied to the cross as a symbol; and provides a synoptic placement for archetypal criticism…

  12. How Critical Is Critical Thinking?

    Science.gov (United States)

    Shaw, Ryan D.

    2014-01-01

    Recent educational discourse is full of references to the value of critical thinking as a 21st-century skill. In music education, critical thinking has been discussed in relation to problem solving and music listening, and some researchers suggest that training in critical thinking can improve students' responses to music. But what exactly is…

  13. Optimization by simulation of the coupling between a sub-critical reactor and its spallation source. Towards a pilot reactor; Optimisation par simulation du couplage entre un reacteur sous-critique et sa source de spallation. Application a un demonstrateur

    Energy Technology Data Exchange (ETDEWEB)

    Kerdraon, D

    2001-10-01

    Accelerator Driven Systems (ADS), based on a proton accelerator and a sub-critical core coupled with a spallation target, offer advantages in order to reduce the nuclear waste radiotoxicity before repository closure. Many studies carried out on the ADS should lead to the definition of an experimental plan which would federate the different works in progress. This thesis deals with the neutronic Monte Carlo simulations with the MCNPX code to optimize such a system in view of a pilot reactor building. First, we have recalled the main neutronic properties of an hybrid reactor. The concept of gas-cooled eXperimental Accelerator Driven System (XADS) chosen for our investigations comes from the preliminary studies done by the Framatome company. In order to transmute minor actinides, we have considered the time evolution of the main fuels which could be reasonably used for the demonstration phases. The neutronic parameters of the reactor, concerning minor actinide transmutation, are reported. Also, we have calculated the characteristic times and the transmutation rates in the case of {sup 99}Tc and {sup 129}I isotopes. We have identified some neutronic differences between an experimental and a power ADS according to the infinite multiplication coefficient, the shape factor and the level of flux to extend the demonstrator concept. We have proposed geometric solutions to keep the radial shape factor of a power ADS acceptable. In the last part, beyond the experimental XADS scope, we have examined the possible transition towards an uranium/thorium cycle based on Molten Salt Reactors using a power ADS in order to generate the required {sup 233}U proportion. (author)

  14. Criticality Model

    Energy Technology Data Exchange (ETDEWEB)

    A. Alsaed

    2004-09-14

    The ''Disposal Criticality Analysis Methodology Topical Report'' (YMP 2003) presents the methodology for evaluating potential criticality situations in the monitored geologic repository. As stated in the referenced Topical Report, the detailed methodology for performing the disposal criticality analyses will be documented in model reports. Many of the models developed in support of the Topical Report differ from the definition of models as given in the Office of Civilian Radioactive Waste Management procedure AP-SIII.10Q, ''Models'', in that they are procedural, rather than mathematical. These model reports document the detailed methodology necessary to implement the approach presented in the Disposal Criticality Analysis Methodology Topical Report and provide calculations utilizing the methodology. Thus, the governing procedure for this type of report is AP-3.12Q, ''Design Calculations and Analyses''. The ''Criticality Model'' is of this latter type, providing a process evaluating the criticality potential of in-package and external configurations. The purpose of this analysis is to layout the process for calculating the criticality potential for various in-package and external configurations and to calculate lower-bound tolerance limit (LBTL) values and determine range of applicability (ROA) parameters. The LBTL calculations and the ROA determinations are performed using selected benchmark experiments that are applicable to various waste forms and various in-package and external configurations. The waste forms considered in this calculation are pressurized water reactor (PWR), boiling water reactor (BWR), Fast Flux Test Facility (FFTF), Training Research Isotope General Atomic (TRIGA), Enrico Fermi, Shippingport pressurized water reactor, Shippingport light water breeder reactor (LWBR), N-Reactor, Melt and Dilute, and Fort Saint Vrain Reactor spent nuclear fuel (SNF). The scope of

  15. Critical Muralism

    Science.gov (United States)

    Rosette, Arturo

    2009-01-01

    This study focuses on the development and practices of Critical Muralists--community-educator-artist-leader-activists--and situates these specifically in relation to the Mexican mural tradition of los Tres Grandes and in relation to the history of public art more generally. The study examines how Critical Muralists address artistic and…

  16. Spatio-Temporal Patterns and Source Identification of Water Pollution in Lake Taihu (China

    Directory of Open Access Journals (Sweden)

    Yan Chen

    2016-03-01

    Full Text Available Various multivariate methods were used to analyze datasets of river water quality for 11 variables measured at 20 different sites surrounding Lake Taihu from 2006 to 2010 (13,200 observations, to determine temporal and spatial variations in river water quality and to identify potential pollution sources. Hierarchical cluster analysis (CA grouped the 12 months into two periods (May to November, December to the next April and the 20 sampling sites into two groups (A and B based on similarities in river water quality characteristics. Discriminant analysis (DA was important in data reduction because it used only three variables (water temperature, dissolved oxygen (DO and five-day biochemical oxygen demand (BOD5 to correctly assign about 94% of the cases and five variables (petroleum, volatile phenol, dissolved oxygen, ammonium nitrogen and total phosphorus to correctly assign >88.6% of the cases. In addition, principal component analysis (PCA identified four potential pollution sources for Clusters A and B: industrial source (chemical-related, petroleum-related or N-related, domestic source, combination of point and non-point sources and natural source. The Cluster A area received more industrial and domestic pollution-related agricultural runoff, whereas Cluster B was mainly influenced by the combination of point and non-point sources. The results imply that comprehensive analysis by using multiple methods could be more effective for facilitating effective management for the Lake Taihu Watershed in the future.

  17. ADS次临界堆脉冲中子源实验动态特性数值模拟研究%Numerical Simulation of Dynamic Characteristic in Accelerator Driven System Sub-critical Reactor Pulse Neutron Source Experiments

    Institute of Scientific and Technical Information of China (English)

    谢芹; 谢金森; 曾文杰; 何丽华; 刘紫静; 于涛

    2015-01-01

    Drive by intense external neutron sources and the deep subcritical levels make Ac-celerator Driven Subcritical reactor have a great difference between traditional critical reactors in neutronics parameters. It makes the deterministic neutronic calculation method could not be used in ADS subcritical reactor calculating directly. In this paper,the pulse neutron source ex-periments in the fast/thermal-combined ADS system facility ( YLINA-Booster expermental facilty) are simulated by Monte Carlo N-Particle eXtended (MCNPX) code. The simulation re-sults are compared with the results of detectors in the experiments. The results clearly indicate that in different reactor core layouts and different neutron source characteristics,the simulation results are in excellent agreement with the experiment,and the MCNPX code could be used to study ADS Subcritical reactor neutronics dynamic parameters.%强外源驱动与深次临界度使得ADS次临界反应堆在中子学特性上与传统临界堆有较大差异,确定论中子学计算方法难以直接应用于ADS次临界堆。本文采用MCNPX程序对“快热”耦合ADS装置YALINA-Booster的PNS实验进行了模拟,并将模拟与实验结果进行比较。结果表明:在不同的堆芯布置方案和不同脉冲中子源特性下,模拟结果与实验结果具有良好的一致性,验证采用MCNPX程序研究ADS次临界堆中子学动态特性的可行性。

  18. Critical proximity

    Directory of Open Access Journals (Sweden)

    Simon, Jane

    2010-01-01

    Full Text Available This essay considers how written language frames visual objects. Drawing on Michel Foucault’s response to Raymond Roussel’s obsessive description, the essay proposes a model of criticism where description might press up against its objects. This critical closeness is then mapped across the conceptual art practice and art criticism of Ian Burn. Burn attends to the differences between seeing and reading, and considers the conditions which frame how we look at images, including how we look at, and through words. The essay goes on to consider Meaghan Morris’s writing on Lynn Silverman’s photographs. Both Morris and Burn offer an alternative to a parasitic model of criticism and enact a patient way of looking across and through visual landscapes.

  19. Critical Proximity

    Directory of Open Access Journals (Sweden)

    Jane Simon

    2010-09-01

    Full Text Available This essay considers how written language frames visual objects. Drawing on Michel Foucault’s response to Raymond Roussel’s obsessive description, the essay proposes a model of criticism where description might press up against its objects. This critical closeness is then mapped across the conceptual art practice and art criticism of Ian Burn. Burn attends to the differences between seeing and reading, and considers the conditions which frame how we look at images, including how we look at, and through words. The essay goes on to consider Meaghan Morris’s writing on Lynn Silverman’s photographs. Both Morris and Burn offer an alternative to a parasitic model of criticism and enact a patient way of looking across and through visual landscapes.

  20. The Critical Bricolage

    Directory of Open Access Journals (Sweden)

    Kim McMillan

    2015-10-01

    Full Text Available Change in health care has become rapid and continuous. Much decision-making processes guiding change management are derived from organizational literature which is heavily reflective of managerial perspectives. These perspectives represent and aim to serve only a small subgroup of organizational members. However, change is complex, fragile, and has higher rates of success and sustainability when change management strategies reflect a multitude of organizational voices. There is a dearth of literature exploring the intersect between organizational and nursing discourses on the subject of rapid and continuous change in health care. Multitheoretical, multimethodological, and multidisciplinary informed approaches to methodological decision making are needed to link organizational and nursing discourses in ways that will offer alternative perspectives on the subject of change. Furthermore, critically guided multitheoretical, multimethodological, and multidisciplinary methodologies are timely and important in organizational research. Critically guided research seeks to analyze taken-for-granted assumptions and institutionalized practices seeking alternative perspectives and alternative sources of organizational knowledge. Exploring alternative perspectives from a critical lens recognizes the impact predominant discursive influences have on change management and the subsequent impact on organizational members’ working lives. This article will explore how Kincheloe’s discussions of the critical bricolage serve to support combining critical organizational methodologies (guided by Alvesson and Deetz with a voice-centered relational method of data analysis (guided by Brown and Gilligan to create a critical interpretive methodology that explores the voices of nurses as they experience rapid and continuous change in health care.

  1. Nuclear criticality safety: 2-day training course

    Energy Technology Data Exchange (ETDEWEB)

    Schlesser, J.A. [ed.] [comp.

    1997-02-01

    This compilation of notes is presented as a source reference for the criticality safety course. At the completion of this training course, the attendee will: be able to define terms commonly used in nuclear criticality safety; be able to appreciate the fundamentals of nuclear criticality safety; be able to identify factors which affect nuclear criticality safety; be able to identify examples of criticality controls as used as Los Alamos; be able to identify examples of circumstances present during criticality accidents; have participated in conducting two critical experiments; be asked to complete a critique of the nuclear criticality safety training course.

  2. Critical Vidders

    DEFF Research Database (Denmark)

    Svegaard, Robin Sebastian Kaszmarczyk

    2015-01-01

    This article will introduce and take a look at a specific subset of the fan created remix videos known as vids, namely those that deal with feminist based critique of media. Through examples, it will show how fans construct and present their critique, and finally broach the topic of the critical ...

  3. Critical Vidders

    DEFF Research Database (Denmark)

    Svegaard, Robin Sebastian Kaszmarczyk

    2015-01-01

    This article will introduce and take a look at a specific subset of the fan created remix videos known as vids, namely those that deal with feminist based critique of media. Through examples, it will show how fans construct and present their critique, and finally broach the topic of the critical...

  4. Quantum Criticality

    OpenAIRE

    Keimer, Bernhard; Sachdev, Subir

    2011-01-01

    This is a review of the basic theoretical ideas of quantum criticality, and of their connection to numerous experiments on correlated electron compounds. A shortened, modified, and edited version appeared in Physics Today. This arxiv version has additional citations to the literature.

  5. 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...

  6. 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.

  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. Development and application of a coupled bio-geochmical and hydrological model for point and non-point source river water pollution

    Science.gov (United States)

    Pohlert, T.

    2007-12-01

    The aim of this paper is to present recent developments of an integrated water- and N-balance model for the assessment of land use changes on water and N-fluxes for meso-scale river catchments. The semi-distributed water-balance model SWAT was coupled with algorithms of the bio-geochemical model DNDC as well as the model CropSyst. The new model that is further denoted as SWAT-N was tested with leaching data from a long- term lysimeter experiment as well as results from a 5-years sampling campaign that was conducted at the outlet of the meso-scale catchment of the River Dill (Germany). The model efficiency for N-load as well as the spatial representation of N-load along the river channel that was tested with results taken from longitudinal profiles show that the accuracy of the model has improved due to the integration of the aforementioned process-oriented models. After model development and model testing, SWAT-N was then used for the assessment of the EU agricultural policy (CAP reform) on land use change and consequent changes on N-fluxes within the Dill Catchment. giessen.de/geb/volltexte/2007/4531/

  9. 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.

  10. Bibliometric analysis on literatures of Non-Point Source Pollution at A Watershed Scale%流域非点源污染文献计量分析

    Institute of Scientific and Technical Information of China (English)

    马鑫; 闫铁柱; 曹洪涛; 陈少波

    2014-01-01

    非点源污染成为制约中国社会经济和环境可持续发展的重要因素.为了准确掌握流域非点源污染研究的全球状况和前沿动态,客观反映相关国家或地区在该领域的科学能力和科学影响,采用ISI Web of Knowlere的Web of Science引文数据库,选用基本检索方式,以流域非点源的相关术语作为主题检索词,对1900年-2012年之间该库收录的此领域的相关文献进行计量分析.结果表明:从发文量、研究机构和研究人员、高被引文献分析可以看出,美国在此领域成绩卓越,领先于其他国家;在典型机理模型运用方面,SWAT的发文量最多,占模型运用相关文献发文量的52%;国际上该领域最主要的期刊有Journal of The American Water Resources Association、Science of The Total Environment、Journal of Hydrology和Journal of Environmental Quality;中国科学院、北京师范大学和浙江大学的流域非点源污染领域发文量在中国位居前3位.

  11. 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...

  12. Critical reading and critical thinking Critical reading and critical thinking

    Directory of Open Access Journals (Sweden)

    Loni Kreis Taglieber

    2008-04-01

    Full Text Available The purpose of this paper is to provide, for L1 and L2 reading and writing teachers, a brief overview of the literature about critical reading and higher level thinking skills. The teaching of these skills is still neglected in some language classes in Brazil, be it in L1 or in L2 classes. Thus, this paper may also serve as a resource guide for L1 and/or L2 reading and writing teachers who want to incorporate critical reading and thinking into their classes. In modern society, even in everyday life people frequently need to deal with complicated public and political issues, make decisions, and solve problems. In order to do this efficiently and effectively, citizens must be able to evaluate critically what they see, hear, and read. Also, with the huge amount of printed material available in all areas in this age of “information explosion” it is easy to feel overwhelmed. But often the information piled up on people’s desks and in their minds is of no use due to the enormous amount of it. The purpose of this paper is to provide, for L1 and L2 reading and writing teachers, a brief overview of the literature about critical reading and higher level thinking skills. The teaching of these skills is still neglected in some language classes in Brazil, be it in L1 or in L2 classes. Thus, this paper may also serve as a resource guide for L1 and/or L2 reading and writing teachers who want to incorporate critical reading and thinking into their classes. In modern society, even in everyday life people frequently need to deal with complicated public and political issues, make decisions, and solve problems. In order to do this efficiently and effectively, citizens must be able to evaluate critically what they see, hear, and read. Also, with the huge amount of printed material available in all areas in this age of “information explosion” it is easy to feel overwhelmed. But often the information piled up on people’s desks and in their minds is of

  13. Critical scattering

    Energy Technology Data Exchange (ETDEWEB)

    Stirling, W.G. [Liverpool Univ., Dep. of Physics, Liverpool (United Kingdom); Perry, S.C. [Keele Univ. (United Kingdom). Dept. of Physics

    1996-12-31

    We outline the theoretical and experimental background to neutron scattering studies of critical phenomena at magnetic and structural phase transitions. The displacive phase transition of SrTiO{sub 3} is discussed, along with examples from recent work on magnetic materials from the rare-earth (Ho, Dy) and actinide (NpAs, NpSb, USb) classes. The impact of synchrotron X-ray scattering is discussed in conclusion. (author) 13 figs., 18 refs.

  14. How Critical Is Critical Infrastructure?

    Science.gov (United States)

    2015-09-01

    to Examine Critical Issues Underlying the Planned Rebuilding at the World Trade Center Site. 178 HVS Global Hospitality Services, 2012 Manhattan...Hotel Market Overview (Mineola, NY: HVS Global Hospitality Services, 2012, http://www.hvs.com/Content/3268.pdf. 179 “Key Office Properties,” accessed...premier real estate, luxury shopping, world class hotels, destination dining, and tourism , into an area that produces cumulative consumer spending of

  15. [Critical incidents].

    Science.gov (United States)

    Scheidegger, D

    2005-03-01

    In medicine real severe mishaps are rare. On the other hand critical incidents are frequent. Anonymous critical incident reporting systems allow us to learn from these mishaps. This learning process will make our daily clinical work safer Unfortunately, before these systems can be used efficiently our professional culture has to be changed. Everyone in medicine has to admit that errors do occur to see the need for an open discussion. If we really want to learn from errors, we cannot punish the individual, who reported his or her mistake. The interest is primarily in what has happened and why it has happened and not who has committed this mistake. The cause for critical incidents in medicine is in over 80% the human factor Poor communication, work under enormous stress, conflicts and hierarchies are the main cause. This has been known for many years, therefore have already 15 years ago high-tech industries, like e.g. aviation, started to invest in special courses on team training. Medicine is a typical profession were until now only the individual performance decided about the professional career Communication, conflict management, stress management, decision making, risk management, team and team resource management were subjects that have never been taught during our preor postgraduate education. These points are the most important ones for an optimal teamwork. A multimodular course designed together with Swissair (Human Aspect Development medical, HADmedical) helps to cover, as in aviation, the soft factor and behavioural education in medicine and to prepare professionals in health care to work as a real team.

  16. Nitrogen Source Inventory and Loading Tool: An integrated approach toward restoration of water-quality impaired karst springs.

    Science.gov (United States)

    Eller, Kirstin T; Katz, Brian G

    2017-07-01

    Nitrogen (N) from anthropogenic sources has contaminated groundwater used as drinking water in addition to impairing water quality and ecosystem health of karst springs. The Nitrogen Source Inventory and Loading Tool (NSILT) was developed as an ArcGIS and spreadsheet-based approach that provides spatial estimates of current nitrogen (N) inputs to the land surface and loads to groundwater from nonpoint and point sources within the groundwater contributing area. The NSILT involves a three-step approach where local and regional land use practices and N sources are evaluated to: (1) estimate N input to the land surface, (2) quantify subsurface environmental attenuation, and (3) assess regional recharge to the aquifer. NSILT was used to assess nitrogen loading to groundwater in two karst spring areas in west-central Florida: Rainbow Springs (RS) and Kings Bay (KB). The karstic Upper Floridan aquifer (UFA) is the source of water discharging to the springs in both areas. In the KB study area (predominantly urban land use), septic systems and urban fertilizers contribute 48% and 22%, respectively, of the estimated total annual N load to groundwater 294,400 kg-N/yr. In contrast for the RS study area (predominantly agricultural land use), livestock operations and crop fertilizers contribute 50% and 13%, respectively, of the estimated N load to groundwater. Using overall groundwater N loading rates for the KB and RS study areas, 4.4 and 3.3 kg N/ha, respectively, and spatial recharge rates, the calculated groundwater nitrate-N concentration (2.1 mg/L) agreed closely with the median nitrate-N concentration (1.7 mg/L) from groundwater samples in agricultural land use areas in the RS study area for the period 2010-2014. NSILT results provide critical information for prioritizing and designing restoration efforts for water-quality impaired springs and spring runs affected by multiple sources of nitrogen loading to groundwater. The calculated groundwater N concentration for

  17. Critical reading and critical thinking

    Directory of Open Access Journals (Sweden)

    Loni Kreis Taglieber

    2003-01-01

    Full Text Available The purpose of this paper is to provide, for L1 and L2 reading and writing teachers, a brief overview of the literature about critical reading and higher level thinking skills. The teaching of these skills is still neglected in some language classes in Brazil, be it in L1 or in L2 classes. Thus, this paper may also serve as a resource guide for L1 and/or L2 reading and writing teachers who want to incorporate critical reading and thinking into their classes. In modern society, even in everyday life people frequently need to deal with complicated public and political issues, make decisions, and solve problems. In order to do this efficiently and effectively, citizens must be able to evaluate critically what they see, hear, and read. Also, with the huge amount of printed material available in all areas in this age of “information explosion” it is easy to feel overwhelmed. But often the information piled up on people’s desks and in their minds is of no use due to the enormous amount of it.

  18. Critical Mass

    CERN Multimedia

    AUTHOR|(CDS)2070299

    2017-01-01

    Critical Mass is a cycling event typically held on the last Friday of every month; its purpose is not usually formalized beyond the direct action of meeting at a set location and time and traveling as a group through city or town streets on bikes. The event originated in 1992 in San Francisco; by the end of 2003, the event was being held in over 300 cities around the world. At CERN it is held once a year in conjunction with the national Swiss campaing "Bike to work".

  19. An Analysis of the Non-point Pollution Load on the Urban Roof in Xinxiang City%新乡市城区屋面非点源污染负荷分析

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The purpose of this study is probing into the pollutants variation characteristics of urban roof runoff ,the quantification of the pollution load ,as well as analyzing the effect on the receiving water .The aim is to provide a basis for using urban rainfall effec‐tively ,controlling non-point source pollution ,improving water environment ,and so on .Taking urban roof as the catchments area in Xinxiang City ,we do research on the hydrology and water quality process of each rainfall event with natural rain condition .The sam‐ples were chosen to analyze the contents of SS ,COD and TN .The results show that the volume of urban roof runoff is 14 .786 4 mil‐lion m3 in 2012 .Meanwhile ,based on the event mean concentration as the main parameter ,the pollution load of SS ,COD and TN are 982 .96 t ,2 871 .62 t and 225 .71 t respectively ,and the proportions which discharges into the receiving water are 31 .7% , 15 .4% and 8 .5% of the total pollution load .%对城区屋面径流污染变化特征以及污染负荷的定量化研究,并分析其对受纳水体的影响,可为城市利用雨水、非点源污染控制、水环境改善等提供依据。以屋面作为汇水区域,开展天然降雨情况下场次降雨径流水文水质过程试验监测,水质指标包括SS、COD、T N。研究结果表明:2012年新乡市城区屋面径流量为1478.64万m3;以场次平均浓度作为主要参数,计算SS、COD、T N污染负荷量分别为982.96 t、2871.62 t、225.71 t ,分别占排入受纳水体总污染负荷的31.7%、15.4%、8.5%。

  20. Control factors and critical conditions between carbon sinking and sourcing of wetland ecosystem%湿地生态系统碳汇与碳源过程的控制因子和临界条件

    Institute of Scientific and Technical Information of China (English)

    孟伟庆; 吴绽蕾; 王中良

    2011-01-01

    Wetlands is the most important carbon sink as its special structure and characteristics. However the carbon sink functional of wetland has been weakened because of climate change and utilization, thus the trend that carbon sink conversion into carbon source is obvious. The control factors and critical conditions between carbon sinking and sourcing of wetland ecosystem were summarized from water content, plant types, soil thickness and microorganism which include substrate, Ph, temperature and redox conditions. The wetland oxygen condition is determined by the water level of wetland. There is a positive correlation between wetland water level and methane production, meanwhile it has negative correlation with carbon dioxide. The absorption and emission of carbon in wetland is affected by aerenchyma and root exudates of plant, but also the height and coverage of plant are important influence factors. The difference of microbial activity in different depths of soil layer, which result into the difference of absorption and emission carbon. The influence factors of active degree of methanogens include substrate, Ph, temperature and redox conditions. The production rate of CO2 and CH4 in shallow soil layer is higher than deep soil. Generally the increase of the substrate concentration will improve the methane generated rate and neutral or weak alkaline environment is the most suitable conditions for methanogens. Of course temperature also is the influence of methane generate and carbon dioxide. It has a negative correlation relationship between redox potential and methane generating. To summarize, because of the complexity of ecosystem struceture and the process of carbon emission and absorption, it can not give a clear conclusion that wetland is carbon sink or sourse in a word. But it is clear that control factors and critical conditions will transfer in certain environment conditions, and so some measures can be taken to improve the carbon sink functional of wetland

  1. Tracing seasonal nitrate sources and loads in the San Joaquin River using nitrogen and oxygen stable isotopes

    Science.gov (United States)

    Young, M. B.; Kendall, C.; Silva, S.; Stringfellow, W. T.; Dahlgren, R. A.

    2007-12-01

    The San Joaquin River (SJR) is a heavily impacted river draining a major agricultural basin in central California. This river receives nitrate inputs from multiple point and non-point sources including agriculture, livestock, waste water treatment plants, septic systems, urban run-off, and natural soil leaching. Nitrate inputs to the SJR may play a significant role in driving algal blooms and reducing overall water quality. The San Joaquin River discharges into the San Francisco Bay-Delta ecosystem, and reduced water quality and large algal blooms in the SJR may play a significant role in driving critically low oxygen levels in the Stockton Deep Water Shipping Channel. Correct identification of the major nitrate sources to the SJR is important for coordinating mitigation efforts throughout the SJR-Delta-San Francisco Bay region. Measurements of the nitrogen and oxygen isotopic composition of nitrate were made monthly to bimonthly from 2005 through 2007 within the Lower SJR, major tributaries, and various other water input sources in order to assess spatial and temporal variations in nitrate inputs and cycling in this heavily impacted watershed. The oxygen and hydrogen isotopic composition of water was also measured to better distinguish water sources and identify changes in water inputs. A very wide range of δ15N-NO3 and δ18O-NO3 values were observed in the main stem SJR and tributaries. The δ15N values ranged from +2 to +17 ‰, and the δ18O values ranged from -1 to +18 ‰. Except for a major agricultural drain site (San Luis Drain), all the sites showed temporal changes in both δ15N-NO3 and δ18O-NO3 much greater than the differences seen between individual sites. In general, the δ15N values of nitrate in the larger tributary rivers (Merced, Tuolumne and Stanislaus) were much lower than those of the main stem SJR from April to May; however, after June the tributary values began to rise toward the values in the main stem river. Some of the highest δ15N-NO3

  2. A study of physics of sub-critical multiplicative systems driven by sources and the utilization of deterministic codes in calculation of this systems; Um estudo da fisica de sistemas multiplicativos subcriticos acionados por fontes e a utilizacao de codigos deterministicos no calculo destes sistemas

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Alberi

    2008-07-01

    This work presents the Physics of Source Driven Systems (ADS). It shows some statics and K{sub i}netics parameters of the reactor Physics and when it is sub critical, that are important in evaluation and definition of these systems. The objective is to demonstrate that there are differences in parameters when the reactor is critical. Moreover, the work shows the differences observed in the parameters for different calculation models. Two calculation methodologies are shown In this dissertation: Gandini and Salvatores and Dulla, and some parameters are calculated. The ANISN deterministic transport code is used in calculation in order to compare these parameters. In a subcritical configuration of IPEN-MB-01 Reactor driven by an external source some parameters are calculated. The conclusions about calculation realized are presented in end of work. (author)

  3. Critical Pedagogy for Critical Mathematics Education

    Science.gov (United States)

    Tutak, Fatma Aslan; Bondy, Elizabeth; Adams, Thomasenia L.

    2011-01-01

    This article provides a brief introduction to critical pedagogy and further discussion on critical mathematics education. Critical mathematics education enables students to read the world with mathematics. Three emerging domains of mathematics education related to critical mathematics education are discussed in this manuscript: ethnomathematics,…

  4. Critical Pedagogy for Critical Mathematics Education

    Science.gov (United States)

    Tutak, Fatma Aslan; Bondy, Elizabeth; Adams, Thomasenia L.

    2011-01-01

    This article provides a brief introduction to critical pedagogy and further discussion on critical mathematics education. Critical mathematics education enables students to read the world with mathematics. Three emerging domains of mathematics education related to critical mathematics education are discussed in this manuscript: ethnomathematics,…

  5. Environmental Modeling, The goal of the Nonpoint Source Management Program is to minimize nonpoint source pollution ("Pointless Personal Pollution") from new land use activities and to reduce pollution from existing activities., Published in 2011, 1:24000 (1in=2000ft) scale, Florida Department of Environmental Protection.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Environmental Modeling dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Other information as of 2011. It is described as 'The...

  6. Putting the Critical Back in Critical Infrastructure

    Science.gov (United States)

    2015-12-01

    CRITICAL BACK IN CRITICAL INFRASTRUCTURE by Bradford C. Mason December 2015 Thesis Advisor: Rudolph P. Darken Second Reader: Thomas Mackin...COVERED Master’s thesis 4. TITLE AND SUBTITLE PUTTING THE CRITICAL BACK IN CRITICAL INFRASTRUCTURE 5. FUNDING NUMBERS 6. AUTHOR(S) Bradford C. Mason...12b. DISTRIBUTION CODE A 13. ABSTRACT (maximum 200 words) In the context of national critical infrastructure security and resilience doctrine

  7. Critical Evaluation of the Implementation of Mitigation Options for Phosphorus from Field to Catchment Scales

    DEFF Research Database (Denmark)

    O. Maguire, Rory; Rubæk, Gitte Holton; E. Haggard, Brian;

    2009-01-01

    Received for publication December 19, 2007. Nutrient regulations have been developed over the past decades to limit anthropogenic inputs of phosphorus (P) to surface waters. All of the regulations were promulgated in response to decreased water quality, which was at least partially associated wit....... This paper discusses the different regulations that have developed in these four regions, evaluates the strategies used to prevent non-point source pollution of P, reports impacts on water quality, and looks for lessons that can be learned as we move forward......Received for publication December 19, 2007. Nutrient regulations have been developed over the past decades to limit anthropogenic inputs of phosphorus (P) to surface waters. All of the regulations were promulgated in response to decreased water quality, which was at least partially associated...

  8. Critical Gerontology and Education for Older Adults.

    Science.gov (United States)

    Weiland, Steven

    1995-01-01

    Traces sources of critical gerontology to the movement toward interpretive social science and to the interdisciplinary nature of gerontology. Examples of uses of critical gerontology are offered in accounts of the history of the social construction of aging and of wisdom and religion in postmodern life. (SK)

  9. Augustine and Education in Critical Thinking

    Science.gov (United States)

    Puolimatka, Tapio

    2005-01-01

    Augustine's concept of the deep self provides a basis for a complex and many-faceted account of critical thinking. He uncovers the moral sources of thinking in the inner depths of the self and shows that critical thinking presupposes radical self-reflection ready to face the truth about oneself. Self-knowledge assumes transparency, consciousness…

  10. Fostering Critical Thinking in Physical Education Students

    Science.gov (United States)

    Lodewyk, Ken R.

    2009-01-01

    Critical thinking is essentially "better thinking." When students think critically they consider complex information from numerous sources and perspectives in order to make a reasonable judgment that they can justify. It has been associated with academic qualities such as decision-making, creativity, reasoning, problem-solving, debating,…

  11. Nuclear Criticality Safety Data Book

    Energy Technology Data Exchange (ETDEWEB)

    Hollenbach, D. F. [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2016-11-14

    The objective of this document is to support the revision of criticality safety process studies (CSPSs) for the Uranium Processing Facility (UPF) at the Y-12 National Security Complex (Y-12). This design analysis and calculation (DAC) document contains development and justification for generic inputs typically used in Nuclear Criticality Safety (NCS) DACs to model both normal and abnormal conditions of processes at UPF to support CSPSs. This will provide consistency between NCS DACs and efficiency in preparation and review of DACs, as frequently used data are provided in one reference source.

  12. AS A SOURCE OF NEW TURKISH LITERATURE HISTORY AND HISTORICAL CRITICISM / “YENİ TÜRK EDEBİYATI” KAYNAĞI OLARAK TARİH ve TARİHÎ ELESTİRİ

    Directory of Open Access Journals (Sweden)

    Dr. Muharrem DAYANÇ

    2009-01-01

    Full Text Available Interdisciplinary connections in social siciencescontribute to the scientific qualificaitons of the thestudies. Therefore, “history” and “method of historicalstudies” are the initial fields for every literatureresearchers. In this article, we tried to bring up history asa supply and source of inspiration for literature.Moreover, we wanted to expose the literary works asimportant documents for history discipline.

  13. Nuclear criticality safety guide

    Energy Technology Data Exchange (ETDEWEB)

    Pruvost, N.L.; Paxton, H.C. [eds.

    1996-09-01

    This technical reference document cites information related to nuclear criticality safety principles, experience, and practice. The document also provides general guidance for criticality safety personnel and regulators.

  14. 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.

  15. Legacy source of mercury in an urban stream-wetland ecosystem in central North Carolina, USA.

    Science.gov (United States)

    Deonarine, Amrika; Hsu-Kim, Heileen; Zhang, Tong; Cai, Yong; Richardson, Curtis J

    2015-11-01

    In the United States, aquatic mercury contamination originates from point and non-point sources to watersheds. Here, we studied the contribution of mercury in urban runoff derived from historically contaminated soils and the subsequent production of methylmercury in a stream-wetland complex (Durham, North Carolina), the receiving water of this runoff. Our results demonstrated that the mercury originated from the leachate of grass-covered athletic fields. A fraction of mercury in this soil existed as phenylmercury, suggesting that mercurial anti-fungal compounds were historically applied to this soil. Further downstream in the anaerobic sediments of the stream-wetland complex, a fraction (up to 9%) of mercury was converted to methylmercury, the bioaccumulative form of the metal. Importantly, the concentrations of total mercury and methylmercury were reduced to background levels within the stream-wetland complex. Overall, this work provides an example of a legacy source of mercury that should be considered in urban watershed models and watershed management.

  16. Multiple sources of boron in urban surface waters and groundwaters

    Energy Technology Data Exchange (ETDEWEB)

    Hasenmueller, Elizabeth A., E-mail: eahasenm@wustl.edu; Criss, Robert E.

    2013-03-01

    Previous studies attribute abnormal boron (B) levels in streams and groundwaters to wastewater and fertilizer inputs. This study shows that municipal drinking water used for lawn irrigation contributes substantial non-point loads of B and other chemicals (S-species, Li, and Cu) to surface waters and shallow groundwaters in the St. Louis, Missouri, area. Background levels and potential B sources were characterized by analysis of lawn and street runoff, streams, rivers, springs, local rainfall, wastewater influent and effluent, and fertilizers. Urban surface waters and groundwaters are highly enriched in B (to 250 μg/L) compared to background levels found in rain and pristine, carbonate-hosted streams and springs (< 25 μg/L), but have similar concentrations (150 to 259 μg/L) compared to municipal drinking waters derived from the Missouri River. Other data including B/SO{sub 4}{sup 2-}−S and B/Li ratios confirm major contributions from this source. Moreover, sequential samples of runoff collected during storms show that B concentrations decrease with increased discharge, proving that elevated B levels are not primarily derived from combined sewer overflows (CSOs) during flooding. Instead, non-point source B exhibits complex behavior depending on land use. In urban settings B is rapidly mobilized from lawns during “first flush” events, likely representing surficial salt residues from drinking water used to irrigate lawns, and is also associated with the baseflow fraction, likely derived from the shallow groundwater reservoir that over time accumulates B from drinking water that percolates into the subsurface. The opposite occurs in small rural watersheds, where B is leached from soils by recent rainfall and covaries with the event water fraction. Highlights: ► Boron sources and loads differ between urban and rural watersheds. ► Wastewaters are not the major boron source in small St. Louis, MO watersheds. ► Municipal drinking water used for lawn

  17. A Critical Humanist Curriculum

    Science.gov (United States)

    Magill, Kevin; Rodriguez, Arturo

    2015-01-01

    This essay is a critical humanist discussion of curriculum; a departure from the technicist view of education [education meant to support a global capitalist economy] and an analysis of curriculum considering critical humanism, political economy and critical race theory among other modes of critical analysis and inquiry. Our discussion supports a…

  18. Criticality Analysis of GTPPS

    Directory of Open Access Journals (Sweden)

    Asis Sarkar

    2011-10-01

    Full Text Available The paper is concerned with the study of criticality analysis of components of Gas Turbine Power Plant Systems (GTPPS and the failures occurring in the plant. Failure mode and effect and criticality analysis (FMECA is carried out to estimate the criticality number for different components and failure modes. In addition the failure effects, higher effects and end effectsare incorporated in the final FMECA sheet. The criticality resultscompensating provision will highlight possible ways to tackle thefailures economically. The findings in this Paper are (1 criticality index of the components (2 Critical failures (3 compensating provision of critical failure.

  19. High-efficiency high-energy Ka source for the critically-required maximum illumination of x-ray optics on Z using Z-petawatt-driven laser-breakout-afterburner accelerated ultrarelativistic electrons LDRD .

    Energy Technology Data Exchange (ETDEWEB)

    Sefkow, Adam B.; Bennett, Guy R.

    2010-09-01

    Under the auspices of the Science of Extreme Environments LDRD program, a <2 year theoretical- and computational-physics study was performed (LDRD Project 130805) by Guy R Bennett (formally in Center-01600) and Adam B. Sefkow (Center-01600): To investigate novel target designs by which a short-pulse, PW-class beam could create a brighter K{alpha} x-ray source than by simple, direct-laser-irradiation of a flat foil; Direct-Foil-Irradiation (DFI). The computational studies - which are still ongoing at this writing - were performed primarily on the RedStorm supercomputer at Sandia National Laboratories Albuquerque site. The motivation for a higher efficiency K{alpha} emitter was very clear: as the backlighter flux for any x-ray imaging technique on the Z accelerator increases, the signal-to-noise and signal-to-background ratios improve. This ultimately allows the imaging system to reach its full quantitative potential as a diagnostic. Depending on the particular application/experiment this would imply, for example, that the system would have reached its full design spatial resolution and thus the capability to see features that might otherwise be indiscernible with a traditional DFI-like x-ray source. This LDRD began FY09 and ended FY10.

  20. A Critical Look into Critical Pedagogy

    Science.gov (United States)

    Pishghadam, Reza; Meidani, Elham Naji

    2012-01-01

    In line with postmodern philosophy, critical pedagogy has gained considerable importance and has become a valuable educational goal. The purpose of this study is to dig into the effects of critical pedagogy in a modernist educational system. To this aim, 15 Iranian university students were asked to write down their feelings at the end of a course…

  1. A Critical Look into Critical Pedagogy

    Science.gov (United States)

    Pishghadam, Reza; Meidani, Elham Naji

    2012-01-01

    In line with postmodern philosophy, critical pedagogy has gained considerable importance and has become a valuable educational goal. The purpose of this study is to dig into the effects of critical pedagogy in a modernist educational system. To this aim, 15 Iranian university students were asked to write down their feelings at the end of a course…

  2. Critical Approaches to Critical Pedagogy in Greece

    Science.gov (United States)

    Grollios, George; Liambas, Anastassios

    2015-01-01

    This paper is an initial review of the presentations and uses of critical pedagogy in Greek educational literature since the mid-1980s. These have appeared in the form of three books and an edited volume (translated in Greek), all written by American critical educators, as well as in texts produced by Greek educators who have either written the…

  3. Advanced Neutron Source (ANS) Project

    Science.gov (United States)

    Campbell, J. H.

    1992-01-01

    This report discusses the following about the Advanced Neutron Source: Project Management; Research and Development; Fuel Development; Corrosion Loop Tests and Analyses; Thermal-Hydraulic Loop Tests; Reactor Control and Shutdown Concepts; Critical and Subcritical Experiments; Material Data, Structural Tests, and Analysis; Cold-Source Development; Beam Tube, Guide, and Instrument Development; Hot-Source Development; Neutron Transport and Shielding; I & C Research and Development; Design; and Safety.

  4. Source Water Protection Contaminant Sources

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Simplified aggregation of potential contaminant sources used for Source Water Assessment and Protection. The data is derived from IDNR, IDALS, and US EPA program...

  5. Characterization of sources and loadings of fecal pollutants using microbial source tracking assays in urban and rural areas of the Grand River Watershed, Southwestern Ontario.

    Science.gov (United States)

    Lee, Dae-Young; Lee, Hung; Trevors, Jack T; Weir, Susan C; Thomas, Janis L; Habash, Marc

    2014-04-15

    Sources of fecal water pollution were assessed in the Grand River and two of its tributaries (Ontario, Canada) using total and host-specific (human and bovine) Bacteroidales genetic markers in conjunction with reference information, such as land use and weather. In-stream levels of the markers and culturable Escherichia coli were also monitored during multiple rain events to gain information on fecal loadings to catchment from diffuse sources. Elevated human-specific marker levels were accurately identified in river water impacted by a municipal wastewater treatment plant (WWTP) effluent and at a downstream site in the Grand River. In contrast, the bovine-specific marker showed high levels of cattle fecal pollution in two tributaries, both of which are characterized as intensely farmed areas. The bovine-specific Bacteroidales marker increased with rainfall in the agricultural tributaries, indicating enhanced loading of cattle-derived fecal pollutants to river from non-point sources following rain events. However, rain-triggered fecal loading was not substantiated in urban settings, indicating continuous inputs of human-originated fecal pollutants from point sources, such as WWTP effluent. This study demonstrated that the Bacteroidales source tracking assays, in combination with land use information and hydrological data, may provide additional insight into the spatial and temporal distribution of source-specific fecal contamination in streams impacted by varying land uses. Using the approach described in this study may help to characterize impacted water sources and to design targeted land use management plans in other watersheds in the future.

  6. Advanced positron sources

    Energy Technology Data Exchange (ETDEWEB)

    Variola, A., E-mail: variola@lal.in2p3.fr

    2014-03-11

    Positron sources are a critical system for the future lepton colliders projects. Due to the large beam emittance at the production and the limitation given by the target heating and mechanical stress, the main collider parameters fixing the luminosity are constrained by the e{sup +} sources. In this context also the damping ring design boundary conditions and the final performance are given by the injected positron beam. At present different schemes are being taken into account in order to increase the production and the capture yield of the positron sources, to reduce the impact of the deposited energy in the converter target and to increase the injection efficiency in the damping ring. The final results have a strong impact not only on the collider performance but also on its cost optimization. After a short introduction illustrating their fundamental role, the basic positron source scheme and the performance of the existing sources will be illustrated. The main innovative designs for the future colliders advanced sources will be reviewed and the different developed technologies presented. Finally the positrons-plasma R and D experiments and the futuristic proposals for positron sources will reviewed.

  7. An integrated approach to assess heavy metal source apportionment in peri-urban agricultural soils

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ying; Li, Tingqiang; Wu, Chengxian [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); He, Zhenli [University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States); Japenga, Jan; Deng, Meihua [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Xiaoe, E-mail: xeyang@zju.edu.cn [Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China)

    2015-12-15

    Highlights: • Heavy metal source apportionment was conducted in peri-urban agricultural areas. • Precise and quantified results were obtained by using isotope ratio analysis. • The integration of IRA, GIS, PCA, and CA was proved to be more reliable. • Hg pollution was from the use of organic fertilizers in this area. - Abstract: Three techniques (Isotope Ratio Analysis, GIS mapping, and Multivariate Statistical Analysis) were integrated to assess heavy metal pollution and source apportionment in peri-urban agricultural soils. The soils in the study area were moderately polluted with cadmium (Cd) and mercury (Hg), lightly polluted with lead (Pb), and chromium (Cr). GIS Mapping suggested Cd pollution originates from point sources, whereas Hg, Pb, Cr could be traced back to both point and non-point sources. Principal component analysis (PCA) indicated aluminum (Al), manganese (Mn), nickel (Ni) were mainly inherited from natural sources, while Hg, Pb, and Cd were associated with two different kinds of anthropogenic sources. Cluster analysis (CA) further identified fertilizers, waste water, industrial solid wastes, road dust, and atmospheric deposition as potential sources. Based on isotope ratio analysis (IRA) organic fertilizers and road dusts accounted for 74–100% and 0–24% of the total Hg input, while road dusts and solid wastes contributed for 0–80% and 19–100% of the Pb input. This study provides a reliable approach for heavy metal source apportionment in this particular peri-urban area, with a clear potential for future application in other regions.

  8. From Critical Theory to Critical Hermeneutics

    National Research Council Canada - National Science Library

    Øjvind Larsen

    2014-01-01

    From their beginning in the 1930s, critical theory and the Frankfurt school had their focus on a critique of disturbed social relations in western society dominated by totalitarian political regimes...

  9. From Critical Theory to Critical Hermeneutics

    OpenAIRE

    Øjvind Larsen

    2014-01-01

    From their beginning in the 1930s, critical theory and the Frankfurt school had their focus on a critique of disturbed social relations in western society dominated by totalitarian political regimes like Stalinism, Fascism, Nazism, and by capitalism as an oppressive and destructive economic system and culture. Now, 80 years later, this has all become history and thus it is time to leave the concept of critical theory behind us, and instead bring the concept of critique to a broader theoretica...

  10. Surgical Critical Care Initiative

    Data.gov (United States)

    Federal Laboratory Consortium — The Surgical Critical Care Initiative (SC2i) is a USU research program established in October 2013 to develop, translate, and validate biology-driven critical care....

  11. Interface localization near criticality

    CERN Document Server

    Delfino, Gesualdo

    2016-01-01

    The theory of interface localization in near-critical planar systems at phase coexistence is formulated from first principles. We show that mutual delocalization of two interfaces, amounting to interfacial wetting, occurs when the bulk correlation length critical exponent $\

  12. California Condor Critical Habitat

    Data.gov (United States)

    California Department of Resources — These Data identify (in general) the areas where critical habitat for the California Condor occur. Critical habitat for the species consists of the following 10...

  13. Critical dynamics near QCD critical point

    CERN Document Server

    Minami, Yuki

    2012-01-01

    In this thesis, we study the critical dynamics near the QCD critical point. Near the critical point, the relevant modes for the critical dynamics are identified as the hydrodynamic modes. Thus, we first study the linear dynamics of them by the relativistic hydrodynamics. We show that the thermal diffusion mode is the most relevant mode, whereas the sound mode is suppressed around the critical point. We also find that the Landau equation, which is believed to be an acausal hydrodynamic equation, has no problem to describe slowly varying fluctuations. Moreover, we find that the Israel-Stewart equation, which is a causal one, gives the same result as the Landau equation gives in the long-wavelength region. Next, we study the nonlinear dynamics of the hydrodynamic modes by the nonlinear Langevin equation and the dynamic renormalization group (RG). In the vicinity of the critical point, the usual hydrodynamics breaks down by large fluctuations. Thus, we must consider the nonlinear Langevin equation. We construct t...

  14. Toward critical bioethics.

    Science.gov (United States)

    Árnason, Vilhjálmur

    2015-04-01

    This article deals with the question as to what makes bioethics a critical discipline. It considers different senses of criticism and evaluates their strengths and weaknesses. A primary method in bioethics as a philosophical discipline is critical thinking, which implies critical evaluation of concepts, positions, and arguments. It is argued that the type of analytical criticism that restricts its critical role to critical thinking of this type often suffers from other intellectual flaws. Three examples are taken to demonstrate this: premature criticism, uncritical self-understanding of theoretical assumptions, and narrow framing of bioethical issues. Such flaws can lead both to unfair treatment of authors and to uncritical discussion of topics. In this context, the article makes use of Häyry's analysis of different rationalities in bioethical approaches and argues for the need to recognize the importance of communicative rationality for critical bioethics. A radically different critical approach in bioethics, rooted in social theory, focuses on analyses of power relations neglected in mainstream critical thinking. It is argued that, although this kind of criticism provides an important alternative in bioethics, it suffers from other shortcomings that are rooted in a lack of normative dimensions. In order to complement these approaches and counter their shortcomings, there is a need for a bioethics enlightened by critical hermeneutics. Such hermeneutic bioethics is aware of its own assumptions, places the issues in a wide context, and reflects critically on the power relations that stand in the way of understanding them. Moreover, such an approach is dialogical, which provides both a critical exercise of speech and a normative dimension implied in the free exchange of reasons and arguments. This discussion is framed by Hedgecoe's argument that critical bioethics needs four elements: to be empirically rooted, theory challenging, reflexive, and politely skeptical.

  15. Criticality accident detector coverage analysis using the Monte Carlo Method

    Energy Technology Data Exchange (ETDEWEB)

    Zino, J.F.; Okafor, K.C.

    1993-12-31

    As a result of the need for a more accurate computational methodology, the Los Alamos developed Monte Carlo code MCNP is used to show the implementation of a more advanced and accurate methodology in criticality accident detector analysis. This paper will detail the application of MCNP for the analysis of the areas of coverage of a criticality accident alarm detector located inside a concrete storage vault at the Savannah River Site. The paper will discuss; (1) the generation of fixed-source representations of various criticality fission sources (for spherical geometries); (2) the normalization of these sources to the ``minimum criticality of concern`` as defined by ANS 8.3; (3) the optimization process used to determine which source produces the lowest total detector response for a given set of conditions; and (4) the use of this minimum source for the analysis of the areas of coverage of the criticality accident alarm detector.

  16. Reimagining Critical Theory

    Science.gov (United States)

    Rexhepi, Jevdet; Torres, Carlos Alberto

    2011-01-01

    This paper discusses Critical Theory, a model of theorizing in the field of the political sociology of education. We argue for a "reimagined" Critical Theory to herald an empowering, liberatory education that fosters curiosity and critical thinking, and a means for successful bottom-up, top-down political engagement. We present arguments at a…

  17. Reimagining Critical Theory

    Science.gov (United States)

    Rexhepi, Jevdet; Torres, Carlos Alberto

    2011-01-01

    This paper discusses Critical Theory, a model of theorizing in the field of the political sociology of education. We argue for a "reimagined" Critical Theory to herald an empowering, liberatory education that fosters curiosity and critical thinking, and a means for successful bottom-up, top-down political engagement. We present arguments…

  18. Foundations for Critical Thinking

    Science.gov (United States)

    Bers, Trudy; Chun, Marc; Daly, William T.; Harrington, Christine; Tobolowsky, Barbara F.

    2015-01-01

    "Foundations for Critical Thinking" explores the landscape of critical-thinking skill development and pedagogy through foundational chapters and institutional case studies involving a range of students in diverse settings. By establishing a link between active learning and improved critical thinking, this resource encourages all higher…

  19. Reimagining Critical Theory

    Science.gov (United States)

    Rexhepi, Jevdet; Torres, Carlos Alberto

    2011-01-01

    This paper discusses Critical Theory, a model of theorizing in the field of the political sociology of education. We argue for a "reimagined" Critical Theory to herald an empowering, liberatory education that fosters curiosity and critical thinking, and a means for successful bottom-up, top-down political engagement. We present arguments…

  20. International critical perspectives

    NARCIS (Netherlands)

    Sambrook, S.A.; Poell, R.F.

    2014-01-01

    The Problem Critical perspectives on human resource development (HRD) have emerged, across Europe and America, hailed as the future of the field. However, we note the paucity of critical perspectives globally, the problematic dominance of critical HRD activities in Western sites of theory and

  1. Criticism, Visible and Invisible.

    Science.gov (United States)

    Frye, Northrop

    1964-01-01

    The central activity of literary criticism, the understanding of literature, is related to the process of establishing a context for the works of literature being studied. Choosing not to discuss the factual elements of literary criticism, the author clarifies and concentrates on the "lower" and "upper" limits of criticism. While the "lower" limit…

  2. Creating a Critical Thinker

    Science.gov (United States)

    Piergiovanni, Polly R.

    2014-01-01

    A college education is expected to improve students' critical thinking skills. Keeping students active in class--through writing activities and class discussion--has been shown to help students think critically. In this article, creative hands-on activities, which are common in engineering courses, are shown to improve students' critical thinking…

  3. Reconceptualising Critical Digital Literacy

    Science.gov (United States)

    Pangrazio, Luciana

    2016-01-01

    While it has proved a useful concept during the past 20 years, the notion of "critical digital literacy" requires rethinking in light of the fast-changing nature of young people's digital practices. This paper contrasts long-established notions of "critical digital literacy" (based primarily around the critical consumption of…

  4. Reconceptualising Critical Digital Literacy

    Science.gov (United States)

    Pangrazio, Luciana

    2016-01-01

    While it has proved a useful concept during the past 20 years, the notion of "critical digital literacy" requires rethinking in light of the fast-changing nature of young people's digital practices. This paper contrasts long-established notions of "critical digital literacy" (based primarily around the critical consumption of…

  5. Creating a Critical Thinker

    Science.gov (United States)

    Piergiovanni, Polly R.

    2014-01-01

    A college education is expected to improve students' critical thinking skills. Keeping students active in class--through writing activities and class discussion--has been shown to help students think critically. In this article, creative hands-on activities, which are common in engineering courses, are shown to improve students' critical thinking…

  6. Sourcing Excellence

    DEFF Research Database (Denmark)

    Adeyemi, Oluseyi

    2011-01-01

    Sourcing Excellence is one of the key performance indicators (KPIs) in this world of ever changing sourcing strategies. Manufacturing companies need to access and diagnose the reliability and competencies of existing suppliers in order to coordinate and develop them. This would help in managing...

  7. Sourcing Excellence

    DEFF Research Database (Denmark)

    Adeyemi, Oluseyi

    2011-01-01

    Sourcing Excellence is one of the key performance indicators (KPIs) in this world of ever changing sourcing strategies. Manufacturing companies need to access and diagnose the reliability and competencies of existing suppliers in order to coordinate and develop them. This would help in managing...... in manufacturing companies. In addition, an advanced approach to sourcing involves integrating and coordinating suppliers, common materials, processes, designs and technologies across worldwide buying, design and operating locations. However, since most manufacturing companies do not have well-developed suppliers...... for global sourcing strategies in place, improvement opportunities in this area are attractive and as yet largely unrealized. Shifting from a narrow, cost-reduction emphasis with suppliers to an emphasis on globally integrated and coordinated sourcing strategies with well-developed suppliers would improve...

  8. A predictive model for microbial counts on beaches where intertidal sand is the primary source.

    Science.gov (United States)

    Feng, Zhixuan; Reniers, Ad; Haus, Brian K; Solo-Gabriele, Helena M; Wang, John D; Fleming, Lora E

    2015-05-15

    Human health protection at recreational beaches requires accurate and timely information on microbiological conditions to issue advisories. The objective of this study was to develop a new numerical mass balance model for enterococci levels on nonpoint source beaches. The significant advantage of this model is its easy implementation, and it provides a detailed description of the cross-shore distribution of enterococci that is useful for beach management purposes. The performance of the balance model was evaluated by comparing predicted exceedances of a beach advisory threshold value to field data, and to a traditional regression model. Both the balance model and regression equation predicted approximately 70% the advisories correctly at the knee depth and over 90% at the waist depth. The balance model has the advantage over the regression equation in its ability to simulate spatiotemporal variations of microbial levels, and it is recommended for making more informed management decisions.

  9. Improving Agent Based Modeling of Critical Incidents

    Directory of Open Access Journals (Sweden)

    Robert Till

    2010-04-01

    Full Text Available Agent Based Modeling (ABM is a powerful method that has been used to simulate potential critical incidents in the infrastructure and built environments. This paper will discuss the modeling of some critical incidents currently simulated using ABM and how they may be expanded and improved by using better physiological modeling, psychological modeling, modeling the actions of interveners, introducing Geographic Information Systems (GIS and open source models.

  10. 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.

  11. From Critical Theory to Critical Hermeneutics

    Directory of Open Access Journals (Sweden)

    Øjvind Larsen

    2014-06-01

    Full Text Available From their beginning in the 1930s, critical theory and the Frankfurt school had their focus on a critique of disturbed social relations in western society dominated by totalitarian political regimes like Stalinism, Fascism, Nazism, and by capitalism as an oppressive and destructive economic system and culture. Now, 80 years later, this has all become history and thus it is time to leave the concept of critical theory behind us, and instead bring the concept of critique to a broader theoretical framework like hermeneutics. This allows the possibility of retaining the theoretical intentions of the old Frankfurt school and at the same time there will be no boundaries by specific dominant theoretical perspectives. In this paper, such a framework for a critical hermeneutics is discussed on the basis of Weber’s, Gadamer’s, and Habermas’ theories on hermeneutics within the social sciences.

  12. 2011 Annual Criticality Safety Program Performance Summary

    Energy Technology Data Exchange (ETDEWEB)

    Andrea Hoffman

    2011-12-01

    TSR limits fuel plate bundles to 1085 grams U-235, which is the maximum loading of an ATR fuel element. The overloaded fuel plate bundle contained 1097 grams U-235 and was assembled under an 1100 gram U-235 limit in 1982. In 2003, the limit was reduced to 1085 grams citing a new criticality safety evaluation for ATR fuel elements. The fuel plate bundle inventories were not checked for compliance prior to implementing the reduced limit. A subsequent review of the NMIS inventory did not identify further violations. Requirements Management - The INL Criticality Safety program is organized and well documented. The source requirements for the INL Criticality Safety Program are from 10 CFR 830.204, DOE Order 420.1B, Chapter III, 'Nuclear Criticality Safety,' ANSI/ANS 8-series Industry Standards, and DOE Standards. These source requirements are documented in LRD-18001, 'INL Criticality Safety Program Requirements Manual.' The majority of the criticality safety source requirements are contained in DOE Order 420.1B because it invokes all of the ANSI/ANS 8-Series Standards. DOE Order 420.1B also invokes several DOE Standards, including DOE-STD-3007, 'Guidelines for Preparing Criticality Safety Evaluations at Department of Energy Non-Reactor Nuclear Facilities.' DOE Order 420.1B contains requirements for DOE 'Heads of Field Elements' to approve the criticality safety program and specific elements of the program, namely, the qualification of criticality staff and the method for preparing criticality safety evaluations. This was accomplished by the approval of SAR-400, 'INL Standardized Nuclear Safety Basis Manual,' Chapter 6, 'Prevention of Inadvertent Criticality.' Chapter 6 of SAR-400 contains sufficient detail and/or reference to the specific DOE and contractor documents that adequately describe the INL Criticality Safety Program per the elements specified in DOE Order 420.1B. The Safety Evaluation Report for SAR-400

  13. Critical Psychologies for Critical Health Literacies

    Science.gov (United States)

    Corcoran, Tim

    2014-01-01

    Health education is largely informed by psychological theories and practices that pursue reductionist views of people learning. However, critical attention is moving to understand health in ways that reconsider relationships to context and the forms of life within which everyday living takes place. This shift is apparent in theoretical…

  14. Critical Psychologies for Critical Health Literacies

    Science.gov (United States)

    Corcoran, Tim

    2014-01-01

    Health education is largely informed by psychological theories and practices that pursue reductionist views of people learning. However, critical attention is moving to understand health in ways that reconsider relationships to context and the forms of life within which everyday living takes place. This shift is apparent in theoretical…

  15. Critical incident reporting systems.

    Science.gov (United States)

    Ahluwalia, Jag; Marriott, Lin

    2005-02-01

    Approximately 10% of all hospital admissions are complicated by critical incidents in which harm is caused to the patient - this amounts to more than 850,000 incidents annually. Critical incident reporting (CIR) systems refer to the structured reporting, collation and analysis of such incidents. This article describes the attributes required for an effective CIR system. Example neonatal trigger events and a management pathway for handling a critical incident report are described. The benefits and limitations of CIR systems, reactive and prospective approaches to the analysis of actual or potential critical incidents and the assessment of risk are also reviewed. Individual human error is but one contributor in the majority of critical incidents. Recognition of this and the fostering of an organisational culture that views critical incident reports as an opportunity to learn and to improve future patient care is vital if CIR systems are to be effective.

  16. Vulnerability of critical infrastructures : identifying critical nodes.

    <