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Sample records for distributed watershed pollution

  1. Temporal-spatial distribution of non-point source pollution in a drinking water source reservoir watershed based on SWAT

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    M. Wang

    2015-05-01

    Full Text Available The conservation of drinking water source reservoirs has a close relationship between regional economic development and people’s livelihood. Research on the non-point pollution characteristics in its watershed is crucial for reservoir security. Tang Pu Reservoir watershed was selected as the study area. The non-point pollution model of Tang Pu Reservoir was established based on the SWAT (Soil and Water Assessment Tool model. The model was adjusted to analyse the temporal-spatial distribution patterns of total nitrogen (TN and total phosphorus (TP. The results showed that the loss of TN and TP in the reservoir watershed were related to precipitation in flood season. And the annual changes showed an "M" shape. It was found that the contribution of loss of TN and TP accounted for 84.5% and 85.3% in high flow years, and for 70.3% and 69.7% in low flow years, respectively. The contributions in normal flow years were 62.9% and 63.3%, respectively. The TN and TP mainly arise from Wangtan town, Gulai town, and Wangyuan town, etc. In addition, it was found that the source of TN and TP showed consistency in space.

  2. Spatial distribution and source apportionment of water pollution in different administrative zones of Wen-Rui-Tang (WRT) river watershed, China.

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    Yang, Liping; Mei, Kun; Liu, Xingmei; Wu, Laosheng; Zhang, Minghua; Xu, Jianming; Wang, Fan

    2013-08-01

    Water quality degradation in river systems has caused great concerns all over the world. Identifying the spatial distribution and sources of water pollutants is the very first step for efficient water quality management. A set of water samples collected bimonthly at 12 monitoring sites in 2009 and 2010 were analyzed to determine the spatial distribution of critical parameters and to apportion the sources of pollutants in Wen-Rui-Tang (WRT) river watershed, near the East China Sea. The 12 monitoring sites were divided into three administrative zones of urban, suburban, and rural zones considering differences in land use and population density. Multivariate statistical methods [one-way analysis of variance, principal component analysis (PCA), and absolute principal component score-multiple linear regression (APCS-MLR) methods] were used to investigate the spatial distribution of water quality and to apportion the pollution sources. Results showed that most water quality parameters had no significant difference between the urban and suburban zones, whereas these two zones showed worse water quality than the rural zone. Based on PCA and APCS-MLR analysis, urban domestic sewage and commercial/service pollution, suburban domestic sewage along with fluorine point source pollution, and agricultural nonpoint source pollution with rural domestic sewage pollution were identified to the main pollution sources in urban, suburban, and rural zones, respectively. Understanding the water pollution characteristics of different administrative zones could put insights into effective water management policy-making especially in the area across various administrative zones.

  3. Multiagent distributed watershed management

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    Giuliani, M.; Castelletti, A.; Amigoni, F.; Cai, X.

    2012-04-01

    Deregulation and democratization of water along with increasing environmental awareness are challenging integrated water resources planning and management worldwide. The traditional centralized approach to water management, as described in much of water resources literature, is often unfeasible in most of the modern social and institutional contexts. Thus it should be reconsidered from a more realistic and distributed perspective, in order to account for the presence of multiple and often independent Decision Makers (DMs) and many conflicting stakeholders. Game theory based approaches are often used to study these situations of conflict (Madani, 2010), but they are limited to a descriptive perspective. Multiagent systems (see Wooldridge, 2009), instead, seem to be a more suitable paradigm because they naturally allow to represent a set of self-interested agents (DMs and/or stakeholders) acting in a distributed decision process at the agent level, resulting in a promising compromise alternative between the ideal centralized solution and the actual uncoordinated practices. Casting a water management problem in a multiagent framework allows to exploit the techniques and methods that are already available in this field for solving distributed optimization problems. In particular, in Distributed Constraint Satisfaction Problems (DCSP, see Yokoo et al., 2000), each agent controls some variables according to his own utility function but has to satisfy inter-agent constraints; while in Distributed Constraint Optimization Problems (DCOP, see Modi et al., 2005), the problem is generalized by introducing a global objective function to be optimized that requires a coordination mechanism between the agents. In this work, we apply a DCSP-DCOP based approach to model a steady state hypothetical watershed management problem (Yang et al., 2009), involving several active human agents (i.e. agents who make decisions) and reactive ecological agents (i.e. agents representing

  4. [Watershed water environment pollution models and their applications: a review].

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    Zhu, Yao; Liang, Zhi-Wei; Li, Wei; Yang, Yi; Yang, Mu-Yi; Mao, Wei; Xu, Han-Li; Wu, Wei-Xiang

    2013-10-01

    Watershed water environment pollution model is the important tool for studying watershed environmental problems. Through the quantitative description of the complicated pollution processes of whole watershed system and its parts, the model can identify the main sources and migration pathways of pollutants, estimate the pollutant loadings, and evaluate their impacts on water environment, providing a basis for watershed planning and management. This paper reviewed the watershed water environment models widely applied at home and abroad, with the focuses on the models of pollutants loading (GWLF and PLOAD), water quality of received water bodies (QUAL2E and WASP), and the watershed models integrated pollutant loadings and water quality (HSPF, SWAT, AGNPS, AnnAGNPS, and SWMM), and introduced the structures, principles, and main characteristics as well as the limitations in practical applications of these models. The other models of water quality (CE-QUAL-W2, EFDC, and AQUATOX) and watershed models (GLEAMS and MIKE SHE) were also briefly introduced. Through the case analysis on the applications of single model and integrated models, the development trend and application prospect of the watershed water environment pollution models were discussed.

  5. Pinpointing Watershed Pollution on a Virtual Globe

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    Saunders, Cheston; Taylor, Amy

    2014-01-01

    Pollution is not a problem we just read about anymore. It affects the air we breathe, the land we live on, and the water we consume. After noticing a lack of awareness in students, a lesson was developed that used Google Earth to pinpoint sources of pollution in the local area and in others across the country, and their effects on the surrounding…

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

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    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. Integrated Watershed Pollution Control at Wujingang Canal, China

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

    2012-04-01

    With a drainage area of 400 square kilometers, Wujingang Canal is located at the economically developed Yangtz Delta of eastern China. As a major tributary, the canal contributes a significant amount of pollutant load to the Lake Tai. Over the past many years, water quality of the canal and its tributaries could not meet the lowest Category V of Chinese surface water quality standard, indicating that its water is not suitable for the purposes of irrigation or scenic views. Major pollution sources in the watershed include industries, residential households, agriculture, fishery, and animal feedlot operations. A comprehensive plan with a budget of 2 billion RMB for the Wujingang watershed pollution control was developed in 2008 and has been implemented progressively ever since. Major components of the plan include: (1) advanced treatment of wastewater from industries and municipal sewage plants for further removal of nitrogen and phosphorous; (2) industrial wastewater reuse; (3) contiguous treatment of sewage from rural residential households with cost-effective technologies such as tower ecofilter system; (4) recycling of rural wastes to generate high-value added products using technologies such as multi-phase anaerobic co-digestion; and (5) making full use of the local landscape and configuring physical, chemical, and biological pollutant treatment structures to build the "clean river network" for treatment of mildly polluted agricultural discharge and surface runoff. Through the implementation of the above measures, water quality of the Wujingang Canal and its tributaries is expected to improve to meet Category IV of Chinese surface water quality standard by 2012, and Category III standard by 2020. Keywords watershed pollution control, non-point source pollution, rural sewage, rural waste, Lake Tai

  8. Rainfall Deduction Method for Estimating Non-Point Source Pollution Load for Watershed

    OpenAIRE

    Cai, Ming; Li, Huai-en; KAWAKAMI, Yoji

    2004-01-01

    The water pollution can be divided into point source pollution (PSP) and non-point source pollution (NSP). Since the point source pollution has been controlled, the non-point source pollution is becoming the main pollution source. The prediction of NSP load is being increasingly important in water pollution controlling and planning in watershed. Considering the monitoring data shortage of NPS in China, a practical estimation method of non-point source pollution load --- rainfall deduction met...

  9. Development of Load Duration Curve System in Data Scarce Watersheds Based on a Distributed Hydrological Model

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    WANG, J.

    2017-12-01

    In stream water quality control, the total maximum daily load (TMDL) program is very effective. However, the load duration curves (LDC) of TMDL are difficult to be established because no sufficient observed flow and pollutant data can be provided in data-scarce watersheds in which no hydrological stations or consecutively long-term hydrological data are available. Although the point sources or a non-point sources of pollutants can be clarified easily with the aid of LDC, where does the pollutant come from and to where it will be transported in the watershed cannot be traced by LDC. To seek out the best management practices (BMPs) of pollutants in a watershed, and to overcome the limitation of LDC, we proposed to develop LDC based on a distributed hydrological model of SWAT for the water quality management in data scarce river basins. In this study, firstly, the distributed hydrological model of SWAT was established with the scarce-hydrological data. Then, the long-term daily flows were generated with the established SWAT model and rainfall data from the adjacent weather station. Flow duration curves (FDC) was then developed with the aid of generated daily flows by SWAT model. Considering the goal of water quality management, LDC curves of different pollutants can be obtained based on the FDC. With the monitored water quality data and the LDC curves, the water quality problems caused by the point or non-point source pollutants in different seasons can be ascertained. Finally, the distributed hydrological model of SWAT was employed again to tracing the spatial distribution and the origination of the pollutants of coming from what kind of agricultural practices and/or other human activities. A case study was conducted in the Jian-jiang river, a tributary of Yangtze river, of Duyun city, Guizhou province. Results indicate that this kind of method can realize the water quality management based on TMDL and find out the suitable BMPs for reducing pollutant in a watershed.

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

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    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. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

  11. GIS Based Distributed Runoff Predictions in Variable Source Area Watersheds Employing the SCS-Curve Number

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    Steenhuis, T. S.; Mendoza, G.; Lyon, S. W.; Gerard Marchant, P.; Walter, M. T.; Schneiderman, E.

    2003-04-01

    Because the traditional Soil Conservation Service Curve Number (SCS-CN) approach continues to be ubiquitously used in GIS-BASED water quality models, new application methods are needed that are consistent with variable source area (VSA) hydrological processes in the landscape. We developed within an integrated GIS modeling environment a distributed approach for applying the traditional SCS-CN equation to watersheds where VSA hydrology is a dominant process. Spatial representation of hydrologic processes is important for watershed planning because restricting potentially polluting activities from runoff source areas is fundamental to controlling non-point source pollution. The methodology presented here uses the traditional SCS-CN method to predict runoff volume and spatial extent of saturated areas and uses a topographic index to distribute runoff source areas through watersheds. The resulting distributed CN-VSA method was incorporated in an existing GWLF water quality model and applied to sub-watersheds of the Delaware basin in the Catskill Mountains region of New York State. We found that the distributed CN-VSA approach provided a physically-based method that gives realistic results for watersheds with VSA hydrology.

  12. A systematic assessment of watershed-scale nonpoint source pollution during rainfall-runoff events in the Miyun Reservoir watershed.

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    Qiu, Jiali; Shen, Zhenyao; Wei, Guoyuan; Wang, Guobo; Xie, Hui; Lv, Guanping

    2018-03-01

    The assessment of peak flow rate, total runoff volume, and pollutant loads during rainfall process are very important for the watershed management and the ecological restoration of aquatic environment. Real-time measurements of rainfall-runoff and pollutant loads are always the most reliable approach but are difficult to carry out at all desired location in the watersheds considering the large consumption of material and financial resources. An integrated environmental modeling approach for the estimation of flash streamflow that combines the various hydrological and quality processes during rainstorms within the agricultural watersheds is essential to develop targeted management strategies for the endangered drinking water. This study applied the Hydrological Simulation Program-Fortran (HSPF) to simulate the spatial and temporal variation in hydrological processes and pollutant transport processes during rainstorm events in the Miyun Reservoir watershed, a drinking water resource area in Beijing. The model performance indicators ensured the acceptable applicability of the HSPF model to simulate flow and pollutant loads in the studied watershed and to establish a relationship between land use and the parameter values. The proportion of soil and land use was then identified as the influencing factors of the pollution intensities. The results indicated that the flush concentrations were much higher than those observed during normal flow periods and considerably exceeded the limits of Class III Environmental Quality Standards for Surface Water (GB3838-2002) for the secondary protection zones of the drinking water resource in China. Agricultural land and leached cinnamon soils were identified as the key sources of sediment, nutrients, and fecal coliforms. Precipitation volume was identified as a driving factor that determined the amount of runoff and pollutant loads during rainfall processes. These results are useful to improve the streamflow predictions, provide

  13. Non point source pollution modelling in the watershed managed by Integrated Conctructed Wetlands: A GIS approach.

    OpenAIRE

    Vyavahare, Nilesh

    2008-01-01

    The non-point source pollution has been recognised as main cause of eutrophication in Ireland (EPA Ireland, 2001). Integrated Constructed Wetland (ICW) is a management practice adopted in Annestown stream watershed, located in the south county of Waterford in Ireland, used to cleanse farmyard runoff. Present study forms the annual pollution budget for the Annestown stream watershed. The amount of pollution from non-point sources flowing into the stream was simulated by using GIS techniques; u...

  14. Spatially-Distributed Cost-Effectiveness Analysis Framework to Control Phosphorus from Agricultural Diffuse Pollution.

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    Runzhe Geng

    Full Text Available Best management practices (BMPs for agricultural diffuse pollution control are implemented at the field or small-watershed scale. However, the benefits of BMP implementation on receiving water quality at multiple spatial is an ongoing challenge. In this paper, we introduce an integrated approach that combines risk assessment (i.e., Phosphorus (P index, model simulation techniques (Hydrological Simulation Program-FORTRAN, and a BMP placement tool at various scales to identify the optimal location for implementing multiple BMPs and estimate BMP effectiveness after implementation. A statistically significant decrease in nutrient discharge from watersheds is proposed to evaluate the effectiveness of BMPs, strategically targeted within watersheds. Specifically, we estimate two types of cost-effectiveness curves (total pollution reduction and proportion of watersheds improved for four allocation approaches. Selection of a ''best approach" depends on the relative importance of the two types of effectiveness, which involves a value judgment based on the random/aggregated degree of BMP distribution among and within sub-watersheds. A statistical optimization framework is developed and evaluated in Chaohe River Watershed located in the northern mountain area of Beijing. Results show that BMP implementation significantly (p >0.001 decrease P loss from the watershed. Remedial strategies where BMPs were targeted to areas of high risk of P loss, deceased P loads compared with strategies where BMPs were randomly located across watersheds. Sensitivity analysis indicated that aggregated BMP placement in particular watershed is the most cost-effective scenario to decrease P loss. The optimization approach outlined in this paper is a spatially hierarchical method for targeting nonpoint source controls across a range of scales from field to farm, to watersheds, to regions. Further, model estimates showed targeting at multiple scales is necessary to optimize program

  15. Applying Spatially Distributed Rainfall to a Hydrological Model in a Tropical Watershed, Manoa Watershed, in Hawaii

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    Huang, Y. F.; Tsang, Y. P.

    2017-12-01

    Rainfall in Hawaii is characterized with high spatial and temporal variability. In the south side of Oahu, the Manoa watershed, with an area of 11 km2, has the annual maximum rainfall of 3900mm and the minimum rainfall of 1000 mm. Despite this high spatial heterogeneity, the rain gage network seems insufficiently capture this pattern. When simulating stream flow and predicting floods with hydrological models in Hawaii, the model performance is often unsatisfactory because of inadequate representation of rainfall data. Longman et al. (in prep.) have developed the spatially distributed daily rainfall across the Hawaiian Islands by applying ordinary kriging, yet these data have not been applied to hydrological models. In this study, we used the Soil and Water Assessment Tool (SWAT) model to assess the streamflow simulation by applying spatially-distributed rainfall in the Manoa watershed. We first used point daily-rainfall at Lyon Arboretum from National Center of Environmental Information (NCEI) as the uniform rainfall input. Secondly, we summarized sub-watershed mean rainfall from the daily spatial-statistical rainfall. Both rainfall data are available from 1999 to 2014. The SWAT was set up for five-year warm-up, nine-year calibration, and two-year validation. The model parameters were calibrated and validated with four U.S. Geological Survey stream gages. We compared the calibrated watershed parameters, characteristics, and assess the streamflow hydrographs from these two rainfall inputs. The differences and improvement of using spatially distributed rainfall input in SWAT were discussed. In addition to improving the model by the representation of rainfall, this study helped us having a better understanding of the watershed hydrological response in Hawaii.

  16. Watershed Controls on the Proper Scale of Economic Markets for Pollution Reduction

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    Rigby, J.; Doyle, M. W.; Yates, A.

    2010-12-01

    Markets for tradable discharge permits (TDPs) are an increasingly popular policy instrument for obtaining cost-effective nutrient reduction targets across watersheds. Such markets are also an emerging, dynamic coupling between economic institutions and stream hydrology/biogeochemistry as trading markets become explicit determinants for the spatial distribution of stream nutrient loads. A central problem in any environmental market program is setting the size of the market, as there are distinct trade-offs for large versus small markets. While the overall cost-effectiveness of permit trading increases with the size of the market, the potential for localized and highly damaging nutrient concentrations, or “hotspots”, also increases. Smaller market size reduces the potential for hot spots by dispersing the location of trades, but this may increase the net costs of water quality compliance significantly through both the restriction of possible trading partners and price manipulation by market participants. This project couples a microeconomic model for TDPs (based on possible configurations of mutually exclusive trading zones within the basin) with a semi-distributed water quality model to examine watershed controls on the configuration and scale of such markets. Our results show a wide variation in total annual cost of pollution abatement based on choice of market design -- often with large differences in cost between very similar configurations. This framework is also applied to a 10-member trading program among wastewater treatment plants in the Neuse River, NC, in order to assess (1) the optimum market design for the Upper Neuse basin and (2) how these costs compare with expected costs under alternative market structures (e.g., trading ratio system) and (3) the cost improvements over traditional command-and-control regulatory frameworks. We find that the optimal zone configuration is almost always a lower cost option when compared to a trading ratio scheme and

  17. Characterisation of diffuse pollutions from forested watersheds in Japan during storm events - its association with rainfall and watershed features.

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    Zhang, Zhao; Fukushima, Takehiko; Onda, Yuichi; Mizugaki, Shigeru; Gomi, Takashi; Kosugi, Ken'ichirou; Hiramatsu, Shinya; Kitahara, Hikaru; Kuraji, Koichiro; Terajima, Tomomi; Matsushige, Kazuo; Tao, Fulu

    2008-02-01

    Forest areas have been identified as important sources of nonpoint pollution in Japan. The managers must estimate stormwater quality and quantities from forested watersheds to develop effective management strategies. Therefore, stormwater runoff loads and concentrations of 10 constituents (total suspended solids, dissolved organic carbon, PO(4)-P, dissolved total phosphorus, total phosphorus, NH(4)-N, NO(2)-N, NO(3)-N, dissolved total nitrogen, and total nitrogen) for 72 events across five regions (Aichi, Kochi, Mie, Nagano, and Tokyo) were characterised. Most loads were significantly and positively correlated with stormwater variables (total event rainfall, event duration, and rainfall intensity), but most discharge-weighted event concentrations (DWECs) showed negative correlations with rainfall intensity. Mean water quality concentration during baseflow was correlated significantly with storm concentrations (r=0.41-0.77). Although all pollutant load equations showed high coefficients of determination (R(2)=0.55-0.80), no models predicted well pollutant concentrations, except those for the three N constituents (R(2)=0.59-0.67). Linear regressions to estimate stormwater concentrations and loads were greatly improved by regional grouping. The lower prediction capability of the concentration models for Mie, compared with the other four regions, indicated that other watershed or storm characteristics should be included in the prediction models. Significant differences among regions were found more frequently in concentrations than in loads for all constituents. Since baseflow conditions implied available pollutant sources for stormwater, the similar spatial characteristics of pollutant concentrations between baseflow and stormflow conditions were an important control for stormwater quality.

  18. Calculation and analysis of the non-point source pollution in the upstream watershed of the Panjiakou Reservoir, People's Republic of China

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    Zhang, S.; Tang, L.

    2007-05-01

    Panjiakou Reservoir is an important drinking water resource in Haihe River Basin, Hebei Province, People's Republic of China. The upstream watershed area is about 35,000 square kilometers. Recently, the water pollution in the reservoir is becoming more serious owing to the non-point pollution as well as point source pollution on the upstream watershed. To effectively manage the reservoir and watershed and develop a plan to reduce pollutant loads, the loading of non-point and point pollution and their distribution on the upstream watershed must be understood fully. The SWAT model is used to simulate the production and transportation of the non-point source pollutants in the upstream watershed of the Panjiakou Reservoir. The loadings of non-point source pollutants are calculated for different hydrologic years and the spatial and temporal characteristics of non-point source pollution are studied. The stream network and topographic characteristics of the stream network and sub-basins are all derived from the DEM by ArcGIS software. The soil and land use data are reclassified and the soil physical properties database file is created for the model. The SWAT model was calibrated with observed data of several hydrologic monitoring stations in the study area. The results of the calibration show that the model performs fairly well. Then the calibrated model was used to calculate the loadings of non-point source pollutants for a wet year, a normal year and a dry year respectively. The time and space distribution of flow, sediment and non-point source pollution were analyzed depending on the simulated results. The comparison of different hydrologic years on calculation results is dramatic. The loading of non-point source pollution in the wet year is relatively larger but smaller in the dry year since the non-point source pollutants are mainly transported through the runoff. The pollution loading within a year is mainly produced in the flood season. Because SWAT is a

  19. GIS-based evaluation and spatial distribution characteristics of land degradation in Bijiang watershed.

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    Zhao, Xiaoqing; Dai, Jinhua; Wang, Jianping

    2013-01-01

    Land degradation is one of the significant issues the human beings are confronted with, which has become a bottleneck of restricting the sustainable development of the regional society and economy. In order to ascertain the root causes contributed to the land degradation and characteristics of land degradation, Bijiang watershed, the most important Lead-Zinc mine area of Lanping county of Yunnan Province, was selected as the study area. One evaluation index system for land degradation that consists of 5 single factors(water-soil erosion intensity, geological disaster risk, cultivation intensity of arable land, pollution of heavy metals in soil and biodiversity deterioration) was established and 13 indicators were chosen, and the entropy method was adopted to assign weights to each single factor. By using the tools of Geographic Information System (GIS), the land degradation degree was evaluated and one spatial distribution map for land degradation was accomplished. In this study, the land of the whole watershed was divided into 4 types, including extremely-severe degradation area, severely-degraded area, moderately-degraded area and slightly-degraded area, and some solutions for ecological restoration and rehabilitation were also put forward in this study. The study results indicated that: (1) Water-soil erosion intension and pollution of heavy metals in soil have made greater contribution to the comprehensive land degradation in Bijiang watershed; (2) There is an apparent difference regarding land degradation degree in Bijiang watershed. The moderately-degraded area accounts for the most part in the region, which covers 79.66% of the whole watershed. The severely-degraded area accounts for 15.98% and the slightly-degraded regions and extremely severe degradation area accounts for 1.08% and 3.28% respectively; (3) There is an evident regularity of spatial distribution in land degradation in Bijiang watershed. The moderately-degraded areas mainly distribute in the

  20. Continuous atmosperic pollutant distribution monitor

    International Nuclear Information System (INIS)

    Burger, L.W.

    1984-06-01

    The feasibility of an on-line continuous pollutant distribution monitor has been established. The device employs a small microprocessor to simulate atmospheric dispersion using the segmented Gaussian plume model, an anemometer-bivane to measure the wind conditions, and a control 'box' with which certain model parameters can be specified and changed without interrupting the execution of the computer program. The output of the device is in the form of contours of equal ground-level concentrations on a colour monitor, or a printer dump of the associated graphic screen. The device is only suitable for short range predictions due to the memory limitations of the microprocessor. Predictions are updated approximately once every minute. Various case studies were performed to investigate the behaviour of the model when subjected to controlled input data. A series of short-range experimental runs were conducted in which predicted SO 2 concentrations were compared with measured values. The performance of the model in the case studies was acceptable, and comparisons with the measured SO 2 concentration values proved the model to overpredict by about 30%, which is considered satisfactory. This study can be applied to radioactive effluents transport in the atmosphere

  1. Distribution of heavy metals in sediments of the Ciujung watersheds Banten

    International Nuclear Information System (INIS)

    Th Rina Mulyaningsih; Alfian; Sutisna

    2012-01-01

    Decrease of Ciujung river quality due to industry and community activities. leading to decreased quality of the river. As a result, river designation for raw drinking water, irrigation and fisheries are not suitable. Monitoring the quality of the river is one of the strategies for the environmental protection; therefore a suitable data should be required by government in a regional planning. A study of heavy metal distribution in the watershed Ciujung was carried out to determine its quality. Number of sediment samples was taken from several sampling points in the watershed, based on its pollutant sources identification. Sampling should be limited on main river (not including tributaries) from upstream to downstream river, there are 3] sampling points. Metal was analyzed using neutron activation analysis technique and AAS. The results showed that the distribution of metals Co, As, Sb, Cr, Fe, Mn, Zn, Pb, Cu, Ni and Cd fluctuate depending on the location. The highest concentrations of metals were found in downstream and industries-] area. Evaluation based on the enrichment factor, contamination factor and index of geo accumulation, ware concluded that the quality of upstream is still good has not contaminated / polluted. Industrial-], industrial-2 area and the downstream ware contaminated by Cd metal source from human activity (anthropogenic). Evaluation based on pollution load index indicates that the river has not been contaminated, but the downstream, industry-] and 2 areas has a value almost close IBT baseline level, therefore water quality monitoring in the future remains to be carried out. (author)

  2. 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

  3. Soil Erodibility for Water Pollution Management of Melaka Watershed in Peninsular Malaysia

    Directory of Open Access Journals (Sweden)

    Md. Ibrahim Adham

    2015-07-01

    Full Text Available The relationships between surface runoffand soil erodibility are significant in water pollution and watershed management practices. Land use pattern, soil series and slope percentage are also major factors to develop the relationships. Daily rainfall data were collected and analyzed for variations in precipitation for calculating the surface runoff of these watersheds and surface runoff map was produced by GIS tools. Tew equation was utilized to predict soil erodibility of watershed soils.Results indicated that the weighted curve number varies from 82 to 85 and monthly runoff 23% to 30% among the five watersheds. Soil erodibility varies from 0.038 to 0.06 ton/ha (MJ.mm/ha/h. Linau-Telok-Local Alluvium, Malacca-Munchong, Munchong-Malacca-Serdang and Malacca-Munchong-Tavy are the dominant soil series of this region having the average soil erodibility of about 0.042 ton/ha (MJ.mm/ha/h. The main focus of this study is to provide the information of soil erodibility to reduce the water pollution of a watershed.

  4. An improved risk-explicit interval linear programming model for pollution load allocation for watershed management.

    Science.gov (United States)

    Xia, Bisheng; Qian, Xin; Yao, Hong

    2017-11-01

    Although the risk-explicit interval linear programming (REILP) model has solved the problem of having interval solutions, it has an equity problem, which can lead to unbalanced allocation between different decision variables. Therefore, an improved REILP model is proposed. This model adds an equity objective function and three constraint conditions to overcome this equity problem. In this case, pollution reduction is in proportion to pollutant load, which supports balanced development between different regional economies. The model is used to solve the problem of pollution load allocation in a small transboundary watershed. Compared with the REILP original model result, our model achieves equity between the upstream and downstream pollutant loads; it also overcomes the problem of greatest pollution reduction, where sources are nearest to the control section. The model provides a better solution to the problem of pollution load allocation than previous versions.

  5. An Analysis of Microbial Pollution in the Sinclair-Dyes Inlet Watershed

    Energy Technology Data Exchange (ETDEWEB)

    May, Christopher W.; Cullinan, Valerie I.

    2005-09-21

    This assessment of fecal coliform sources and pathways in Sinclair and Dyes Inlets is part of the Project ENVironmental InVESTment (ENVVEST) being conducted by the Navy's Puget Sound Naval Shipyard and Intermediate Maintenance Facility in cooperation with the US Environmental Protection Agency, Washington State Department of Ecology, the Suquamish Tribe, Kitsap County, the City of Bremerton, the City of Port Orchard, and other local stakeholders. The goal of this study was to identify microbial pollution problems within the Sinclair-Dyes Inlet watershed and to provide a comprehensive assessment of fecal coliform (FC) contamination from all identifiable sources in the watershed. This study quantifies levels of contamination and estimated loadings from known sources within the watersheds and describes pollutant transport mechanisms found in the study area. In addition, the effectiveness of pollution prevention and mitigation measures currently in place within the Sinclair-Dyes Inlet watershed are discussed. This comprehensive study relies on historical data collected by several cooperating agencies, in addition to data collected during the study period from spring 2001 through summer 2005. This report is intended to provide the technical information needed to continue current water quality cleanup efforts and to help implement future efforts.

  6. Integrative Application of Life Cycle Assessment and Risk Assessment to Environmental Impacts of Anthropogenic Pollutants at a Watershed Scale.

    Science.gov (United States)

    Lin, Xiaodan; Yu, Shen; Ma, Hwongwen

    2018-01-01

    Intense human activities have led to increasing deterioration of the watershed environment via pollutant discharge, which threatens human health and ecosystem function. To meet a need of comprehensive environmental impact/risk assessment for sustainable watershed development, a biogeochemical process-based life cycle assessment and risk assessment (RA) integration for pollutants aided by geographic information system is proposed in this study. The integration is to frame a conceptual protocol of "watershed life cycle assessment (WLCA) for pollutants". The proposed WLCA protocol consists of (1) geographic and environmental characterization mapping; (2) life cycle inventory analysis; (3) integration of life-cycle impact assessment (LCIA) with RA via characterization factor of pollutant of interest; and (4) result analysis and interpretation. The WLCA protocol can visualize results of LCIA and RA spatially for the pollutants of interest, which might be useful for decision or policy makers for mitigating impacts of watershed development.

  7. The impact of Land use Change on Water Pollution Index of Kali Madiun Sub-watershed

    Directory of Open Access Journals (Sweden)

    Pranatasari Dyah Susanti

    2017-07-01

    Full Text Available Land use change is one of the effects of population growth and increased human activities. Land use change that overlooked the rule of ecosystem sustainability has a propensity to adversely affect the environment, including the decline of water quality. Kali Madiun is a sub-watershed of Bengawan Solo Watershed that allegedly endured the impacts of land use change. This study aimed to investigate the impacts of land use change on the water quality index of Kali Madiun Sub-watershed. Land use change analysis was done by overlay analysis of spatial data including the maps of land use in 2010 and 2015. Samples were the surface water in the upper, middle and lower part of Kali Madiun Sub-Watershed. Water quality analysis was carried out by comparing the results of water quality parameter assessment based on Government Regulation No. 82 of 2001, while water quality index was figured out by an assessment based on the Decree of the Minister of Environment No. 115 of 2003. The results indicated that during the five years observation, there were land use changes in the upper, middle and lower part of Kali Madiun Sub-watershed. Several parameters increased in 2010 to 2015, namely: TDS, BOD, COD, nitrate, detergents, oils and greases. Pollution index shifted from slightly polluted in 2010 into moderately polluted in 2015. We propose a strategy to solve these problems by the involvement of stakeholders and the participation of local community in managing both domestic and industrial wastes. Also, it should be supported by palpable regulations related to land conversion. Furthermore, it is expected that the effort will reduce the potential of pollution and improve the water quality.

  8. Distribution and contamination of metals in the soil of Guandu Watershed

    Directory of Open Access Journals (Sweden)

    Aldo Pacheco Ferreira

    2015-11-01

    Full Text Available Coastal areas provide important benefits to humans in terms of food resources and ecosystem services. At the same time, human activities can have significant negative impacts on ecosystem health. Thus, control of watershed pollution is both necessary and essential in order to reduce and systematically eliminate the detrimental consequences that are evident in marine and estuarine ecosystems. The present study investigated the distribution of metals at the Guandu Watershed. Five sampling sites were selected for the soil analysis. Samples were collected from February 2013 to December 2014 and analysed for concentrations of As, Cd, Zn, Cu, Pb, Cr, Ni, and Co, using ICP. For control, some samples were used in uncontaminated areas outside the direct effect of chemical industries. The data indicate the presence of metals at the research sites. While the levels of contamination are still slightly below the peak concentrations established by Brazilian legislation, they are approaching levels of concern, particularly with regard to As, Cd, Pb and Cr. The results indicate that the use of water from the Guandu Watershed for recreational purposes and fishing is harmful to both human health and the environment.

  9. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China.

    Science.gov (United States)

    Liu, Renzhi; Liu, Jing; Zhang, Zhijiao; Borthwick, Alistair; Zhang, Ke

    2015-12-02

    Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA), designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the "source-pathway-target" in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing) in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River). Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method.

  10. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China

    Science.gov (United States)

    Liu, Renzhi; Liu, Jing; Zhang, Zhijiao; Borthwick, Alistair; Zhang, Ke

    2015-01-01

    Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA), designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the “source-pathway-target” in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing) in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River). Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method. PMID:26633450

  11. Accidental Water Pollution Risk Analysis of Mine Tailings Ponds in Guanting Reservoir Watershed, Zhangjiakou City, China

    Directory of Open Access Journals (Sweden)

    Renzhi Liu

    2015-12-01

    Full Text Available Over the past half century, a surprising number of major pollution incidents occurred due to tailings dam failures. Most previous studies of such incidents comprised forensic analyses of environmental impacts after a tailings dam failure, with few considering the combined pollution risk before incidents occur at a watershed-scale. We therefore propose Watershed-scale Tailings-pond Pollution Risk Analysis (WTPRA, designed for multiple mine tailings ponds, stemming from previous watershed-scale accidental pollution risk assessments. Transferred and combined risk is embedded using risk rankings of multiple routes of the “source-pathway-target” in the WTPRA. The previous approach is modified using multi-criteria analysis, dam failure models, and instantaneous water quality models, which are modified for application to multiple tailings ponds. The study area covers the basin of Gutanting Reservoir (the largest backup drinking water source for Beijing in Zhangjiakou City, where many mine tailings ponds are located. The resultant map shows that risk is higher downstream of Gutanting Reservoir and in its two tributary basins (i.e., Qingshui River and Longyang River. Conversely, risk is lower in the midstream and upstream reaches. The analysis also indicates that the most hazardous mine tailings ponds are located in Chongli and Xuanhua, and that Guanting Reservoir is the most vulnerable receptor. Sensitivity and uncertainty analyses are performed to validate the robustness of the WTPRA method.

  12. Air Pollution and Watershed Research in the Central Sierra Nevada of California: Nitrogen and Ozone

    Directory of Open Access Journals (Sweden)

    Carolyn Hunsaker

    2007-01-01

    Full Text Available Maintaining healthy forests is the major objective for the Forest Service scientists and managers working for the U.S. Department of Agriculture. Air pollution, specifically ozone (O3 and nitrogenous (N air pollutants, may severely affect the health of forest ecosystems in the western U.S. Thus, the monitoring of air pollution concentration and deposition levels, as well as studies focused on understanding effects mechanisms, are essential for evaluation of risks associated with their presence. Such information is essential for development of proper management strategies for maintaining clean air, clean water, and healthy ecosystems on land managed by the Forest Service. We report on two years of research in the central Sierra Nevada of California, a semi-arid forest at elevations of 1100–2700 m. Information on O3 and N air pollutants is obtained from a network of 18 passive samplers. We relate the atmospheric N concentration to N concentrations in streams, shallow soil water, and bulk deposition collectors within the Kings River Experimental Watershed. This watershed also contains an intensive site that is part of a recent Forest Service effort to calculate critical loads for N, sulfur, and acidity to forest ecosystems. The passive sampler design allows for extensive spatial measurements while the watershed experiment provides intensive spatial data for future analysis of ecosystem processes.

  13. Economic total maximum daily load for watershed-based pollutant trading.

    Science.gov (United States)

    Zaidi, A Z; deMonsabert, S M

    2015-04-01

    Water quality trading (WQT) is supported by the US Environmental Protection Agency (USEPA) under the framework of its total maximum daily load (TMDL) program. An innovative approach is presented in this paper that proposes post-TMDL trade by calculating pollutant rights for each pollutant source within a watershed. Several water quality trading programs are currently operating in the USA with an objective to achieve overall pollutant reduction impacts that are equivalent or better than TMDL scenarios. These programs use trading ratios for establishing water quality equivalence among pollutant reductions. The inbuilt uncertainty in modeling the effects of pollutants in a watershed from both the point and nonpoint sources on receiving waterbodies makes WQT very difficult. A higher trading ratio carries with it increased mitigation costs, but cannot ensure the attainment of the required water quality with certainty. The selection of an applicable trading ratio, therefore, is not a simple process. The proposed approach uses an Economic TMDL optimization model that determines an economic pollutant reduction scenario that can be compared with actual TMDL allocations to calculate selling/purchasing rights for each contributing source. The methodology is presented using the established TMDLs for the bacteria (fecal coliform) impaired Muddy Creek subwatershed WAR1 in Rockingham County, Virginia, USA. Case study results show that an environmentally and economically superior trading scenario can be realized by using Economic TMDL model or any similar model that considers the cost of TMDL allocations.

  14. Stream nitrogen sources apportionment and pollution control scheme development in an agricultural watershed in eastern China.

    Science.gov (United States)

    Chen, Dingjiang; Lu, Jun; Huang, Hong; Liu, Mei; Gong, Dongqin; Chen, Jiabo

    2013-08-01

    A modeling system that couples a land-usebased export coefficient model, a stream nutrient transport equation, and Bayesian statistics was developed for stream nitrogen source apportionment. It divides a watershed into several sub-catchments, and then considers the major landuse categories as stream nitrogen sources in each subcatchment. The runoff depth and stream water depth are considered as the major factors influencing delivery of nitrogen from land to downstream stream node within each sub-catchment. The nitrogen sources and delivery processes are lumped into several constant parameters that were calibrated using Bayesian statistics from commonly available stream monitoring and land-use datasets. This modeling system was successfully applied to total nitrogen (TN) pollution control scheme development for the ChangLe River watershed containing six sub-catchments and four land-use categories. The temporal (across months and years) and spatial (across sub-catchments and land-use categories) variability of nonpoint source (NPS) TN export to stream channels and delivery to the watershed outlet were assessed. After adjustment for in-stream TNretention, the time periods and watershed areas with disproportionately high-TN contributions to the stream were identified. Aimed at a target stream TN level of 2 mg L-1, a quantitative TN pollution control scheme was further developed to determine which sub-catchments, which land-use categories in a sub-catchment, which time periods, and how large of NPS TN export reduction were required. This modeling system provides a powerful tool for stream nitrogen source apportionment and pollution control scheme development at the watershed scale and has only limited data requirements.

  15. Effects of snowmelt on watershed transit time distributions

    Science.gov (United States)

    Fang, Z.; Carroll, R. W. H.; Harman, C. J.; Wilusz, D. C.; Schumer, R.

    2017-12-01

    Snowmelt is the principal control of the timing and magnitude of water flow through alpine watersheds, but the streamflow generated may be displaced groundwater. To quantify this effect, we use a rank StorAge Selection (rSAS) model to estimate time-dependent travel time distributions (TTDs) for the East River Catchment (ERC, 84 km2) - a headwater basin of the Colorado River, and newly designated as the Lawrence Berkeley National Laboratory's Watershed Function Science Focus Area (SFA). Through the SFA, observational networks related to precipitation and stream fluxes have been established with a focus on environmental tracers and stable isotopes. The United Stated Geological Survey Precipitation Runoff Modeling System (PRMS) was used to estimate spatially- and temporally-variable boundary fluxes of effective precipitation (snowmelt & rain), evapotranspiration, and subsurface storage. The DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm was used to calibrate the rSAS model to observed stream isotopic concentration data and quantify uncertainty. The sensitivity of the simulated TTDs to systematic changes in the boundary fluxes was explored. Different PRMS and rSAS model parameters setup were tested to explore how they affect the relationship between input precipitation, especially snowmelt, and the estimated TTDs. Wavelet Coherence Analysis (WCA) was applied to investigate the seasonality of TTD simulations. Our ultimate goal is insight into how the Colorado River headwater catchments store and route water, and how sensitive flow paths and transit times are to climatic changes.

  16. Hydrological modeling of a watershed affected by acid mine drainage (Odiel River, SW Spain). Assessment of the pollutant contributing areas

    Science.gov (United States)

    Galván, L.; Olías, M.; Cánovas, C. R.; Sarmiento, A. M.; Nieto, J. M.

    2016-09-01

    The Odiel watershed drains materials belonging to the Iberian Pyrite Belt, where significant massive sulfide deposits have been mined historically. As a result, a huge amount of sulfide-rich wastes are deposited in the watershed, which suffer from oxidation, releasing acidic lixiviates with high sulfate and metal concentrations. In order to reliably estimate the metal loadings along the watershed a complete series of discharge and hydrochemical data are essential. A hydrological model was performed with SWAT (Soil and Water Assessment Tool) to solve the scarcity of gauge stations along the watershed. The model was calibrated and validated from daily discharge data (from 1980 to 2010) at the outlet of the watershed, river inputs into an existent reservoir, and a flow gauge station close to the northern area of the watershed. Discharge data obtained from the hydrological model, together with analytical data, allowed the estimation of the dissolved pollutant load delivered annually by the Odiel River (e.g. 9140 t of Al, 2760 t of Zn). The pollutant load is influenced strongly by the rainfall regime, and can even double during extremely rainy years. Around 50% of total pollution comes from the Riotinto Mining District, so the treatment of Riotinto lixiviates reaching the Odiel watershed would reduce the AMD (Acid Mine Drainages) in a remarkable way, improving the water quality downstream, especially in the reservoir of Alcolea, currently under construction. The information obtained in this study will allow the optimization of remediation efforts in the watershed, in order to improve its water quality.

  17. Effects of Climate Change on Diffuse Pollution in Lake Mogan Watershed

    Science.gov (United States)

    Alp, E.; Özcan, Z.

    2017-12-01

    Climate change is putting increasing pressure on water bodies. It can affect the behavior of pollutants in the environment and their interaction with the hydrological cycle. For instance, changing precipitation patterns may result in higher volumes of runoff containing numerous contaminants to water bodies and eventually loss of life-supporting function of them. The purpose of this study is to evaluate the impacts of climate change on diffuse pollution in Lake Mogan watershed located in a climate change vulnerable region and where agricultural diffuse pollution is one of the significant concerns. Lake Mogan watershed has an area of 970 km2 and it is dominated by dry agricultural practices and characterized by intermittent creeks. The lake was declared as a special environmental protection region in 1990. In this study, the impacts of climate change on diffuse pollution in the Lake Mogan watershed was evaluated using with a water quality model, SWAT (Soil and Water Assessment Tool). SWAT is a conceptual, continuous time model that operates on a daily time step. The model has been used in many studies to estimate the impacts of climate change, to calculate pollutant loads and to evaluate the best management practices all over the world. The required inputs for SWAT model can be categorized under the following basic categories: topography, land use/land cover, soil properties, land management practices occurring in the watershed, and meteorological inputs. According to Turkish Ministry of Forestry and Water Affairs (2016), it is estimated that the annual average temperature values will increase up to 3.3°C during the 85 year projection period as compared to reference period in the RCP4.5 scenario in the study area. This increase is predicted as up to 5.7°C based on the RCP8.5 scenario. The calibrated SWAT model for the Lake Mogan Watershed is used for the climate change scenarios for a period of 2010 and 2100. It is aimed that the outcomes of this study will help

  18. Multi isotopic characterization (Li-Cu-Zn-Pb) of waste waters pollution in a small watershed (Loire River basin, France)

    Science.gov (United States)

    Millot, R.; Desaulty, A. M.; Perret, S.; Bourrain, X.

    2016-12-01

    The goal of this study is to use multi-isotopic signature to track the pollution in surface waters, and to understand the complex processes causing the metals mobilization and transport in the environment. In the present study, we investigate waste water releases from a hospital water treatment plant and its potential impact in a small river basin near Orléans in France (Egoutier watershed: 15 km²and 5 km long). We decided to monitor this small watershed which is poorly urbanized in the Loire river basin. Its spring is located in a pristine area (forested area), while it is only impacted some kilometers further by the releases rich in metals coming from a hospital water treatment plant. A sampling of these liquid effluents as well as dissolved load and sediment from upstream to downstream was realized and their concentrations and isotopic data were determined. Isotopic ratios were measured using a MC-ICP-MS at BRGM, after a specific protocol of purification for each isotopic systematics. Lithium isotopic compositions are rather homogeneous in river waters along the main course of the stream. The waste water signal is very different from the natural background with significant heavy lithium contribution (high δ7Li). Lead isotopic compositions are rather homogenous in river waters and sediments with values close to geologic background. For Zn, the sediments with high concentrations and depleted isotopic compositions (low δ66Zn), typical of an anthropic pollution, are strongly impacted. The analyses of Cu isotopes in sediments show the impact of waster waters, but also isotopic fractionations due to redox processes in the watershed. To better understand these processes controlling the release of metals in water, sequential extractions on sediments are in progress under laboratory conditions and will provide important constraints for metal distribution in this river basin.

  19. Assessment of Water Quality and Identification of Polluted Risky Regions Based on Field Observations & GIS in the Honghe River Watershed, China

    Science.gov (United States)

    Yan, Chang-An; Zhang, Wanchang; Zhang, Zhijie; Liu, Yuanmin; Deng, Cai; Nie, Ning

    2015-01-01

    Water quality assessment at the watershed scale requires not only an investigation of water pollution and the recognition of main pollution factors, but also the identification of polluted risky regions resulted in polluted surrounding river sections. To realize this objective, we collected water samplings from 67 sampling sites in the Honghe River watershed of China with Grid GIS method to analyze six parameters including dissolved oxygen (DO), ammonia nitrogen (NH3-N), nitrate nitrogen (NO3-N), nitrite nitrogen (NO2-N), total nitrogen (TN) and total phosphorus (TP). Single factor pollution index and comprehensive pollution index were adopted to explore main water pollutants and evaluate water quality pollution level. Based on two evaluate methods, Geo-statistical analysis and Geographical Information System (GIS) were used to visualize the spatial pollution characteristics and identifying potential polluted risky regions. The results indicated that the general water quality in the watershed has been exposed to various pollutants, in which TP, NO2-N and TN were the main pollutants and seriously exceeded the standard of Category III. The zones of TP, TN, DO, NO2-N and NH3-N pollution covered 99.07%, 62.22%, 59.72%, 37.34% and 13.82% of the watershed respectively, and they were from medium to serious polluted. 83.27% of the watershed in total was polluted by comprehensive pollutants. These conclusions may provide useful and effective information for watershed water pollution control and management. PMID:25768942

  20. United States‐Mexican border watershed assessment: Modeling nonpoint source pollution in Ambos Nogales

    Science.gov (United States)

    Norman, Laura M.

    2007-01-01

    Ecological considerations need to be interwoven with economic policy and planning along the United States‐Mexican border. Non‐point source pollution can have significant implications for the availability of potable water and the continued health of borderland ecosystems in arid lands. However, environmental assessments in this region present a host of unique issues and problems. A common obstacle to the solution of these problems is the integration of data with different resolutions, naming conventions, and quality to create a consistent database across the binational study area. This report presents a simple modeling approach to predict nonpoint source pollution that can be used for border watersheds. The modeling approach links a hillslopescale erosion‐prediction model and a spatially derived sediment‐delivery model within a geographic information system to estimate erosion, sediment yield, and sediment deposition across the Ambos Nogales watershed in Sonora, Mexico, and Arizona. This paper discusses the procedures used for creating a watershed database to apply the models and presents an example of the modeling approach applied to a conservation‐planning problem.

  1. Pre- and post-fire pollutant loads in an urban fringe watershed in Southern California.

    Science.gov (United States)

    Burke, M P; Hogue, T S; Kinoshita, A M; Barco, J; Wessel, C; Stein, E D

    2013-12-01

    Post-fire runoff has the potential to be a large source of contaminants to downstream areas. However, the magnitude of this effect in urban fringe watersheds adjacent to large sources of airborne contaminants is not well documented. The current study investigates the impacts of wildfire on stormwater contaminant loading from the upper Arroyo Seco watershed, burned in 2009. This watershed is adjacent to the Greater Los Angeles, CA, USA area and has not burned in over 60 years. Consequently, it acts as a sink for regional urban pollutants and presents an opportunity to study the impacts of wildfire. Pre- and post-fire storm samples were collected and analyzed for basic cations, trace metals, and total suspended solids. The loss of vegetation and changes in soil properties from the fire greatly increased the magnitude of storm runoff, resulting in sediment-laden floods carrying high concentrations of particulate-bound constituents. Post-fire concentrations and loads were up to three orders of magnitude greater than pre-fire values for many trace metals, including lead and cadmium. A shift was also observed in the timing of chemical delivery, where maximum suspended sediment, trace metal, and cation concentrations coincided with, rather than preceded, peak discharge in the post-fire runoff, amplifying the fire's impacts on mass loading. The results emphasize the importance of sediment delivery as a primary mechanism for post-fire contaminant transport and suggest that traditional management practices that focus on treating only the early portion of storm runoff may be less effective following wildfire. We also advocate that watersheds impacted by regional urban pollutants have the potential to pose significant risk for downstream communities and ecosystems after fire.

  2. Sediment-water distribution of contaminants of emerging concern in a mixed use watershed

    Science.gov (United States)

    This study evaluated the occurrence and distribution of 15 contaminants of emerging concern (CEC) in stream water and sediments in the Zumbro River watershed in Minnesota and compared these with sub-watershed land uses. Sixty pairs of sediment and water samples were collected across all seasons from...

  3. Occurrence of THM and NDMA precursors in a watershed: Effect of seasons and anthropogenic pollution.

    Science.gov (United States)

    Aydin, Egemen; Yaman, Fatma Busra; Ates Genceli, Esra; Topuz, Emel; Erdim, Esra; Gurel, Melike; Ipek, Murat; Pehlivanoglu-Mantas, Elif

    2012-06-30

    In pristine watersheds, natural organic matter is the main source of disinfection by-product (DBP) precursors. However, the presence of point or non-point pollution sources in watersheds may lead to increased levels of DBP precursors which in turn form DBPs in the drinking water treatment plant upon chlorination or chloramination. In this study, water samples were collected from a lake used to obtain drinking water for Istanbul as well as its tributaries to investigate the presence of the precursors of two disinfection by-products, trihalomethanes (THM) and N-nitrosodimethylamine (NDMA). In addition, the effect of seasons and the possible relationships between these precursors and water quality parameters were evaluated. The concentrations of THM and NDMA precursors measured as total THM formation potential (TTHMFP) and NDMA formation potential (NDMAFP) ranged between 126 and 1523μg/L THM and NDMA, respectively. Such wide ranges imply that some of the tributaries are affected by anthropogenic pollution sources, which is also supported by high DOC, Cl(-) and NH(3) concentrations. No significant correlation was found between the water quality parameters and DBP formation potential, except for a weak correlation between NDMAFP and DOC concentrations. The effect of the sampling location was more pronounced than the seasonal variation due to anthropogenic pollution in some tributaries and no significant correlation was obtained between the seasons and water quality parameters. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Thermal pollution impacts on rivers and power supply in the Mississippi River watershed

    Science.gov (United States)

    Miara, Ariel; Vörösmarty, Charles J.; Macknick, Jordan E.; Tidwell, Vincent C.; Fekete, Balazs; Corsi, Fabio; Newmark, Robin

    2018-03-01

    Thermal pollution from power plants degrades riverine ecosystems with ramifications beyond the natural environment as it affects power supply. The transport of thermal effluents along river reaches may lead to plant-to-plant interferences by elevating condenser inlet temperatures at downstream locations, which lower thermal efficiencies and trigger regulatory-forced power curtailments. We evaluate thermal pollution impacts on rivers and power supply across 128 plants with once-through cooling technologies in the Mississippi River watershed. By leveraging river network topologies with higher resolutions (0.05°) than previous studies, we reveal the need to address the issue in a more spatially resolved manner, capable of uncovering diverse impacts across individual plants, river reaches and sub-basins. Results show that the use of coarse river network resolutions may lead to substantial overestimations in magnitude and length of impaired river reaches. Overall, there is a modest limitation on power production due to thermal pollution, given existing infrastructure, regulatory and climate conditions. However, tradeoffs between thermal pollution and electricity generation show important implications for the role of alternative cooling technologies and environmental regulation under current and future climates. Recirculating cooling technologies may nearly eliminate thermal pollution and improve power system reliability under stressed climate-water conditions. Regulatory limits also reduce thermal pollution, but at the expense of significant reductions in electricity generation capacity. However, results show several instances when power production capacity rises at individual plants when regulatory limits reduce upstream thermal pollution. These dynamics across energy-water systems highlight the need for high-resolution simulations and the value of coherent planning and optimization across infrastructure with mutual dependencies on natural resources to overcome

  5. Comparison of sediment and nutrient export and runoff characteristics from watersheds with centralized versus distributed stormwater management.

    Science.gov (United States)

    Hopkins, Kristina G; Loperfido, J V; Craig, Laura S; Noe, Gregory B; Hogan, Dianna M

    2017-12-01

    Stormwater control measures (SCMs) are used to retain stormwater and pollutants. SCMs have traditionally been installed in a centralized manner using detention to mitigate peak flows. Recently, distributed SCM networks that treat runoff near the source have been increasingly utilized. The aim of this study was to evaluate differences among watersheds that vary in SCM arrangement by assessing differences in baseflow nutrient (NO x -N and PO 4 - ) concentrations and fluxes, stormflow export of suspended sediments and particulate phosphorus (PP), and runoff characteristics. A paired watershed approach was used to compare export between 2004 and 2016 from one forested watershed (For-MD), one suburban watershed with centralized SCMs (Cent-MD), and one suburban watershed with distributed SCMs (Dist-MD). Results indicated baseflow nitrate (NO x -N) concentrations typically exceeded 1 mg-N/L in all watersheds and were highest in Dist-MD. Over the last 10 years in Dist-MD, nitrate concentrations in both stream baseflow and in a groundwater well declined as land use shifted from agriculture to suburban. Baseflow nitrate export temporarily increased during the construction phase of SCM development in Dist-MD. This temporary pulse of nitrate may be attributed to the conversion of sediment control facilities to SCMs and increased subsurface flushing as infiltration SCMs came on line. During storm flow, Dist-MD tended to have less runoff and lower maximum specific discharge than Cent-MD for small events (runoff responses became increasingly similar to Cent-MD with increasing precipitation (>1.3 cm). Mass export estimated during paired storm events indicated Dist-MD exported 30% less sediment and 31% more PP than Cent-MD. For large precipitation events, export of sediment and PP was similar among all three watersheds. Results suggest that distributed SCMs can reduce runoff and sediment loads during small rain events compared to centralized SCMs, but these differences become

  6. Watershed Modeling Applications with the Open-Access Modular Distributed Watershed Educational Toolbox (MOD-WET) and Introductory Hydrology Textbook

    Science.gov (United States)

    Huning, L. S.; Margulis, S. A.

    2014-12-01

    Traditionally, introductory hydrology courses focus on hydrologic processes as independent or semi-independent concepts that are ultimately integrated into a watershed model near the end of the term. When an "off-the-shelf" watershed model is introduced in the curriculum, this approach can result in a potential disconnect between process-based hydrology and the inherent interconnectivity of processes within the water cycle. In order to curb this and reduce the learning curve associated with applying hydrologic concepts to complex real-world problems, we developed the open-access Modular Distributed Watershed Educational Toolbox (MOD-WET). The user-friendly, MATLAB-based toolbox contains the same physical equations for hydrological processes (i.e. precipitation, snow, radiation, evaporation, unsaturated flow, infiltration, groundwater, and runoff) that are presented in the companion e-textbook (http://aqua.seas.ucla.edu/margulis_intro_to_hydro_textbook.html) and taught in the classroom. The modular toolbox functions can be used by students to study individual hydrologic processes. These functions are integrated together to form a simple spatially-distributed watershed model, which reinforces a holistic understanding of how hydrologic processes are interconnected and modeled. Therefore when watershed modeling is introduced, students are already familiar with the fundamental building blocks that have been unified in the MOD-WET model. Extensive effort has been placed on the development of a highly modular and well-documented code that can be run on a personal computer within the commonly-used MATLAB environment. MOD-WET was designed to: 1) increase the qualitative and quantitative understanding of hydrological processes at the basin-scale and demonstrate how they vary with watershed properties, 2) emphasize applications of hydrologic concepts rather than computer programming, 3) elucidate the underlying physical processes that can often be obscured with a complicated

  7. Effect of forest harvesting best management practices on coarse woody debris distribution in stream and riparian zones in three Appalachian watersheds

    Science.gov (United States)

    J. M. McClure; R. K. Kolka; A. White

    2004-01-01

    The distribution of coarse woody debris (CWD) was analyzed in three Appalachian watersheds in eastern Kentucky, eighteen years after harvest. The three watersheds included an unharvested control (Control), a second watershed with best management practices (BMPs) applied that included a 15.2 m unharvested zone near the stream (BMP watershed), and a third watershed that...

  8. Monitoring Phytophthora ramorum distribution in streams within California watersheds

    Science.gov (United States)

    S.K. Murphy; C. Lee; Y. Valachovic; J. Bienapfl; W. Mark; A. Jirka; D.R. Owen; T.F. Smith; D.M. Rizzo

    2008-01-01

    One hundred-thirteen sites were established in perennial watercourses and sampled for 1 to 3 years between 2004 and 2006 to monitor for presence of Phytophthora ramorum throughout coastal central and northern California watersheds as well as portions of the Sierra Nevada mountain range (Murphy and others 2006). The majority of the monitored...

  9. [Output characteristics of rainfall runoff phosphorus pollution from a typical small watershed in Yimeng mountainous area].

    Science.gov (United States)

    Yu, Xing-xiu; Li, Zhen-wei; Liu, Qian-jin; Jing, Guang-hua

    2012-08-01

    Relationships between phosphorus pollutant concentrations and precipitation-runoff were analyzed by monitoring pollutant losses at outlets of the Menglianggu watershed in 2010. A typical small watershed was selected to examine the runoff and quality parameters such as total phosphorus (TP), particle phosphorus (PP), dissolve phosphorus (DP) and dissolve inorganic phosphorus (DIP) in rainfall-runoff of 10 rainfall events. Precipitation was above 2 mm for all the 10 rainfall events. The results showed that the peak of phosphorus concentrations occurred before the peak of water flows, whereas change processes of the phosphorus fluxes were consistent with that of the water flows and the phosphorus flux also have a strong linear relationship with the water flows. The minimums of the phosphorus concentrations in every 10 natural rainfall events have small differences with each other, but the maximum and EMCs of the phosphorus concentrations have significant differences with each rainfall event. This was mainly influenced by the precipitation, maximum rainfall intensity and mean rainfall intensity (EMCs) and was less influenced by rainfall duration. DP and TP were mainly composed of DIP and PP, respectively. There were no significant correlations between DIP/DP dynamic changes and rainfall characteristics, whereas significant correlations between PP/TP dynamic changes and maximum rainfall intensity were detected. The production of DIP, DP, AND TP were mainly influenced by the direct runoff (DR) and base flow (BF). The EMCs of DIP, DP, TP and the variations of DIP/DP were all found to have significant polynomial relationships with DR/TR., but the dynamic changes of PP/ TP and the EMCS of PP were less influenced by the DR/TR.

  10. Distribution and Ecological Risk Assessment of Heavy Metals in Arable Soils in Bijiang Watershed, China

    Directory of Open Access Journals (Sweden)

    HUANG Wei-heng

    2017-08-01

    Full Text Available It has been paid much attention to soil heavy metal pollution in the Bijiang watershed caused by the Lanping lead-zinc mine. We collected 35 arable soil samples along Bijiang, then sampled and tested the contents of As, Cu, Zn, Cd, Pb, Hg. And then with Nemerow Multi-Factor Index and the Potential Ecological Risk Index method, we evaluated the heavy metal pollution risk. The results showed:(1The accumulation of Pb, Zn, Cd was in a relatively high level, the average was 1 146.97, 579.15, 4.85 mg·kg-1 respectively, which was seriously polluted; the average accumulation of As was 26.85 mg·kg-1; but Cu, Hg was slightly polluted. (2Statistical analysis showed that Lanping area was a main point source pollution of As, Zn, Pb, Cd, while Cu, Hg was pollution caused by different non-point source pollution.(3Within this basin, the Nemerow index was 17.69, which was serious heavy metal pollution, while the comprehensive potential ecological risk index was 773.38, which was a strong potential ecological risk. The contribution of pollutants was Cd > Pb > Zn> As> Hg > Cu. (4As a whole, the soil heavy metal pollution of paddy field was higher than of the dry land.

  11. Can the watershed non-point phosphorus pollution be interpreted by critical soil properties? A new insight of different soil P states.

    Science.gov (United States)

    Lin, Chen; Ma, Ronghua; Xiong, Junfeng

    2018-07-01

    The physicochemical properties of surface soil play a key role in the fate of watershed non-point source pollution. Special emphasis is needed to identify soil properties that are sensitive to both particulate P (PP) pollution and dissolved P (DP) pollution, which is essential for watershed environmental management. The Chaohu Lake basin, a typical eutrophic lake in China, was selected as the study site. The spatial features of the Non-point Source (NPS) PP loads and DP loads were calculated simultaneously based on the integration of sediment delivery distributed model (SEDD) and pollution loads (PLOAD) model. Then several critical physicochemical soil properties, especially various soil P compositions, were innovatively introduced to determine the response of the critical soil properties to NPS P pollution. The findings can be summarized: i) the mean PP load value of the different sub-basins was 5.87 kg, and PP pollution is regarded to be the primary NPS P pollution state, while the DP loads increased rapidly under the rapid urbanization process. ii) iron-bound phosphorus (Fe-P) and aluminum-bound phosphorus (Al-P) are the main components of available P and showed the most sensitive responses to NPS PP pollution, and the correlation coefficients were approximately 0.9. Otherwise, the residual phosphorus (Res-P) was selected as a sensitive soil P state that was significantly negatively correlated with the DP loads. iii) The DP and PP concentrations were represented differently when they were correlated with various soil properties, and the clay proportion was strongly negatively related to the PP loads. Meanwhile, there is a non-linear relationship between the DP loads and the critical soil properties, such as Fe and Total Nitrogen (TN) concentrations. Specifically, a strong inhibitory effect of TN concentration on the DP load was apparent in the Nanfei river (NF) and Paihe (PH) river basins where the R 2 reached 0.67, which contrasts with the relatively poor

  12. Topographic effects on solar radiation distribution in mountainous watersheds and their influence on reference evapotranspiration estimates at watershed scale

    Directory of Open Access Journals (Sweden)

    C. Aguilar

    2010-12-01

    Full Text Available Distributed energy and water balance models require time-series surfaces of the climatological variables involved in hydrological processes. Among them, solar radiation constitutes a key variable to the circulation of water in the atmosphere. Most of the hydrological GIS-based models apply simple interpolation techniques to data measured at few weather stations disregarding topographic effects. Here, a topographic solar radiation algorithm has been included for the generation of detailed time-series solar radiation surfaces using limited data and simple methods in a mountainous watershed in southern Spain. The results show the major role of topography in local values and differences between the topographic approximation and the direct interpolation to measured data (IDW of up to +42% and −1800% in the estimated daily values. Also, the comparison of the predicted values with experimental data proves the usefulness of the algorithm for the estimation of spatially-distributed radiation values in a complex terrain, with a good fit for daily values (R2 = 0.93 and the best fits under cloudless skies at hourly time steps. Finally, evapotranspiration fields estimated through the ASCE-Penman-Monteith equation using both corrected and non-corrected radiation values address the hydrologic importance of using topographically-corrected solar radiation fields as inputs to the equation over uniform values with mean differences in the watershed of 61 mm/year and 142 mm/year of standard deviation. High speed computations in a 1300 km2 watershed in the south of Spain with up to a one-hour time scale in 30 × 30 m2 cells can be easily carried out on a desktop PC.

  13. Distributed models of radionuclide transport on watersheds: development and implementation for the Chernobyl and Fukushima catchments

    Energy Technology Data Exchange (ETDEWEB)

    Kivva, S.; Zheleznyak, M. [Institute of Environmental Radioactivity, Fukushima University (Japan)

    2014-07-01

    The distributed hydrological 'rainfall- runoff' models provide possibilities of the physically based simulation of surface and subsurface flow on watersheds based on the GIS processed data. The success of such modeling approaches for the predictions of the runoff and soil erosion provides a basis for the implementation of the distributed radionuclide transport watershed models. Two distributed watershed models of radionuclide transport - RUNTOX and DHSVM-R have been used to simulate the radionuclide transport in the basin of the Dnieper River, Ukraine and watersheds of Prefecture Fukushima. RUNTOX is used for the simulation of radionuclide wash off from the experimental plots and small watersheds, and DHSVM-R is used for medium and large watersheds RUNTOX is two dimensional distributed hydrological model based on the finite-difference solution of the coupled equations the surface flow, subsurface flow, groundwater flow and advection- dispersion equations of the sediments (eroded soil) and radionuclide transport in liquid and solid phases, taking into parameterize the radionuclide exchanges between liquid and solid phases.. This model has been applied to the experimental plots in Ukraine after the Chernobyl accident and experimental plots in the Fukushima Prefecture. The experience of RUNTOX development and application has been used for the extension of the distributed hydrological model DHSVM by the including of the module of the watershed radionuclide transport. The updated model was named by DHSMV-R. The original DHSVM (Distributed Hydrology Soil Vegetation Model) was developed in the University of Washington and Pacific Northwest National Laboratories. DHSVM is a physical distributed hydrology-vegetation model for complex terrain based on the numerical solution of the network of one dimensional equations. The model accounts explicitly for the spatial distribution of land-surface processes, and can be applied over a range of scales, from plot to large

  14. Hydrographic structure and variability of the Kara Sea: Implications for pollutant distribution

    Science.gov (United States)

    Pavlov, V. K.; Pfirman, S. L.

    Nuclear activity on land and dumping of waste in the Siberian shelf seas mean that the Kara Sea is most likely to experience inputs of radioactivity. Industrial and other anthropogenic activities in the expansive Ob' and Yenisey watersheds also contribute organochlorines, heavy metals and oil to this region. Contaminant fate is influenced by the distribution of the river discharge and processes associated with ice formation and ocean currents. Although average conditions are important in the transport of pollutants, events such as storms and iceberg gouging may be critical in deciding the ultimate fate of dumped and released contaminants.

  15. Construction of a Distributed-network Digital Watershed Management System with B/S Techniques

    Science.gov (United States)

    Zhang, W. C.; Liu, Y. M.; Fang, J.

    2017-07-01

    Integrated watershed assessment tools for supporting land management and hydrologic research are becoming established tools in both basic and applied research. The core of these tools are mainly spatially distributed hydrologic models as they can provide a mechanism for investigating interactions among climate, topography, vegetation, and soil. However, the extensive data requirements and the difficult task of building input parameter files for driving these distributed models, have long been an obstacle to the timely and cost-effective use of such complex models by watershed managers and policy-makers. Recently, a web based geographic information system (GIS) tool to facilitate this process has been developed for a large watersheds of Jinghe and Weihe catchments located in the loess plateau of the Huanghe River basin in north-western China. A web-based GIS provides the framework within which spatially distributed data are collected and used to prepare model input files of these two watersheds and evaluate model results as well as to provide the various clients for watershed information inquiring, visualizing and assessment analysis. This Web-based Automated Geospatial Watershed Assessment GIS (WAGWA-GIS) tool uses widely available standardized spatial datasets that can be obtained via the internet oracle databank designed with association of Map Guide platform to develop input parameter files for online simulation at different spatial and temporal scales with Xing’anjiang and TOPMODEL that integrated with web-based digital watershed. WAGWA-GIS automates the process of transforming both digital data including remote sensing data, DEM, Land use/cover, soil digital maps and meteorological and hydrological station geo-location digital maps and text files containing meteorological and hydrological data obtained from stations of the watershed into hydrological models for online simulation and geo-spatial analysis and provides a visualization tool to help the user

  16. Spatiotemporal patterns and source attribution of nitrogen pollution in a typical headwater agricultural watershed in Southeastern China.

    Science.gov (United States)

    Chen, Wenjun; He, Bin; Nover, Daniel; Duan, Weili; Luo, Chuan; Zhao, Kaiyan; Chen, Wen

    2018-01-01

    Excessive nitrogen (N) discharge from agriculture causes widespread problems in aquatic ecosystems. Knowledge of spatiotemporal patterns and source attribution of N pollution is critical for nutrient management programs but is poorly studied in headwaters with various small water bodies and mini-point pollution sources. Taking a typical small watershed in the low mountains of Southeastern China as an example, N pollution and source attribution were studied for a multipond system around a village using the Hydrological Simulation Program-Fortran (HSPF) model. The results exhibited distinctive spatio-seasonal variations with an overall seriousness rank for the three indicators: total nitrogen (TN) > nitrate/nitrite nitrogen (NO x - -N) > ammonia nitrogen (NH 3 -N), according to the Chinese Surface Water Quality Standard. TN pollution was severe for the entire watershed, while NO x - -N pollution was significant for ponds and ditches far from the village, and the NH 3 -N concentrations were acceptable except for the ponds near the village in summer. Although food and cash crop production accounted for the largest source of N loads, we discovered that mini-point pollution sources, including animal feeding operations, rural residential sewage, and waste, together contributed as high as 47% of the TN and NH 3 -N loads in ponds and ditches. So, apart from eco-fertilizer programs and concentrated animal feeding operations, the importance of environmental awareness building for resource management is highlighted for small farmers in headwater agricultural watersheds. As a first attempt to incorporate multipond systems into the process-based modeling of nonpoint source (NPS) pollution, this work can inform other hydro-environmental studies on scattered and small water bodies. The results are also useful to water quality improvement for entire river basins.

  17. Research and information needs related to nonpoint source pollution and wetlands in the watershed: An EPA perspective

    International Nuclear Information System (INIS)

    Ethridge, B.J.; Olson, R.K.

    1992-01-01

    Two related Environmental Protection Agency (EPA) efforts, wetlands protection and nonpoint source pollution control, fail to fully consider landscape factors when making site-specific decisions. The paper discusses the relationship of the two programs and the use of created and natural wetlands to treat nonpoint source (NPS) pollution. Recommendations to improve the programs include increased technical transfer of existing information, and more research on construction methods and siting of created wetlands to effectively manage NPS pollution. Additional research is also needed to determine (1) the maximum pollutant loading rates to assure the biological integrity of wetlands, (2) the effectiveness of current land-use practices in protecting habitat and water quality functions, (3) wetland functions as pollutant sinks, (4) NPS pollution threats to wildlife, (5) practical watershed models, and (6) indicators and reference sites for monitoring wetland condition. Model watershed demonstrations, jointly implemented by the research and conservation communities, are recommended as a means of integrating research results. (Copyright (c) 1992 - Elsevier Science Publishers B.V.)

  18. Distribution of antibiotic resistance in urban watershed in Japan

    International Nuclear Information System (INIS)

    Ham, Young-Sik; Kobori, Hiromi; Kang, Joo-Hyon; Matsuzaki, Takayuki; Iino, Michiyo; Nomura, Hayashi

    2012-01-01

    Antibiotic-resistant E. coli concentrations showed large spatial and temporal variations, with greater concentrations observed in tributaries and downstream than in the upstream and midstream. Twenty percent of the geometric mean concentrations of antibiotic-resistant E. coli in the Tama River basin (Japan) exceeded the maximum acceptable concentration of indicator E. coli established by the USEPA. The indicator E. coli concentrations were positively correlated with those of antibiotic-resistant E. coli and multiple-antibiotic-resistant E. coli (resistance to more than two kinds of antibiotics), respectively, but not the detection rate of antibiotic-resistant E. coli, implying that use of antibiotic-resistant E. coli concentration rather than the detection rate can be a better approach for water quality assessment. Multiple-antibiotic-resistant E. coli is a useful indicator for estimating the resistance diffusion, water quality degradation and public health risk potential. This assessment provides beneficial information for setting national regulatory or environmental standards and managing integrated watershed areas. - Highlights: ► We extensively observed antibiotic-resistant E. coli (AREc) in Tama River (Japan). ► AREc count rather than the detection rate is better approach for water quality test. ► Multiple-AREc is resistant to the antibiotic to which single-AREc has no resistance. ► Multiple-AREc increase will accelerate the diffusion of antibiotic resistance. - Multiple-antibiotic-resistant E. coli in the watershed can cause the diffusion of conventionally rare antibiotic resistance.

  19. Multi-source water pollution in the Upper Citarum watershed, Indonesia, with special reference to its spatiotemporal variation.

    Science.gov (United States)

    Parikesit; Salim, H; Triharyanto, E; Gunawan, B; Sunardi; Abdoellah, O S; Ohtsuka, R

    2005-01-01

    The Citarum River in West Java is the largest water supplier to the Saguling Dam, which plays a major role in electric power generation for the entire Java Island and is used for the aquaculture of marketed fish. To elucidate the extent of degradation in water quality and its causes in the Upper Citarum watershed, physical, chemical and biological parameters for water samples collected from various sites were analyzed. The results demonstrate large site-to-site variations in water qualities and pollutant loads derived from various human activities such as agriculture, cattle raising and the textile industry. To halt worsening conditions of the Citarum watershed, integrated mitigation efforts should be made, taking biophysical pollution mechanisms and local socioeconomic conditions into account.

  20. Multisite-multivariable sensitivity analysis of distributed watershed models: enhancing the perceptions from computationally frugal methods

    Science.gov (United States)

    This paper assesses the impact of different likelihood functions in identifying sensitive parameters of the highly parameterized, spatially distributed Soil and Water Assessment Tool (SWAT) watershed model for multiple variables at multiple sites. The global one-factor-at-a-time (OAT) method of Morr...

  1. Distributed modeling of radiocesium washoff from the experimental watershed plots of the Fukushima fallout zone

    Science.gov (United States)

    Kivva, Sergei; Zheleznyak, Mark; Konoplev, Alexei; Nanba, Kenji; Onda, Yuichi; Wakiyama Yoshifumi Wakiyama, Yoshifumi

    2015-04-01

    The distributed hydrological "rainfall- runoff" models provide possibilities of the physically based simulation of surface and subsurface flow on watersheds based on the GIS processed data. The success of such modeling approaches for the predictions of the runoff and soil erosion provides a basis for the implementation of the distributed models of the radionuclide washoff from the watersheds. The field studies provided on the Chernobyl and Fukushima catchments provides a unique data sets for the comparative testing and improvements of the modeling tools for the watersheds located in the areas of the very different geographical and hydro-meteorological condition The set of USLE experimental plots has been established by CRIED, University of Tsukuba after the Fukushima accident to study soil erosion and 137Cs wash off from the watersheds (Onda et al, 2014). The distributed watershed models of surface and subsurface flow, sediment and radionuclide transport has been used to simulate the radionuclide transport in the basin Dnieper River, Ukraine and the watersheds of Prefecture Fuksuhima. DHSVM-R is extension of the distributed hydrological model DHSVM (Lettenmayer, Wigmosta et al, 1996-2014) by the including into it the module of the watershed radionuclide transport. DHSVM is a physically based, distributed hydrology-vegetation model for complex terrain based on the numerical solution of the network of one-dimensional equations. The surface flow submodel of DHSMV has been modified: four-directions schematization for the model's cells has been replaced by the eight-directions scheme, more numerically efficient finite -differences scheme was implemented. The new module of radionuclide wash-off from catchment and transport via stream network in soluble phase and on suspended sediments including bottom-water exchange processes was developed for DHSMV-R. DHSVM-R was implemented recently within Swedish- Ukrainian ENSURE project for the modeling of 234U wash-off from the

  2. Development and Application of Watershed Regressions for Pesticides (WARP) for Estimating Atrazine Concentration Distributions in Streams

    Science.gov (United States)

    Larson, Steven J.; Crawford, Charles G.; Gilliom, Robert J.

    2004-01-01

    Regression models were developed for predicting atrazine concentration distributions in rivers and streams, using the Watershed Regressions for Pesticides (WARP) methodology. Separate regression equations were derived for each of nine percentiles of the annual distribution of atrazine concentrations and for the annual time-weighted mean atrazine concentration. In addition, seasonal models were developed for two specific periods of the year--the high season, when the highest atrazine concentrations are expected in streams, and the low season, when concentrations are expected to be low or undetectable. Various nationally available watershed parameters were used as explanatory variables, including atrazine use intensity, soil characteristics, hydrologic parameters, climate and weather variables, land use, and agricultural management practices. Concentration data from 112 river and stream stations sampled as part of the U.S. Geological Survey's National Water-Quality Assessment and National Stream Quality Accounting Network Programs were used for computing the concentration percentiles and mean concentrations used as the response variables in regression models. Tobit regression methods, using maximum likelihood estimation, were used for developing the models because some of the concentration values used for the response variables were censored (reported as less than a detection threshold). Data from 26 stations not used for model development were used for model validation. The annual models accounted for 62 to 77 percent of the variability in concentrations among the 112 model development stations. Atrazine use intensity (the amount of atrazine used in the watershed divided by watershed area) was the most important explanatory variable in all models, but additional watershed parameters significantly increased the amount of variability explained by the models. Predicted concentrations from all 10 models were within a factor of 10 of the observed concentrations at most

  3. Causes and distribution of soil pollution in China

    Directory of Open Access Journals (Sweden)

    Delang Claudio O.

    2017-12-01

    Full Text Available China is the most populated country in the world, but has relatively little fertile land, and even less water. Maintaining the quality of its agricultural land is of paramount importance if China wants to feed its very large and growing population. Yet, China is one of the countries with the largest amount of polluted soil. This paper looks at the causes and distribution of soil pollution in China. It first looks at the amount of organic and inorganic soil pollutants and their geographic distribution. It then looks at the causes of soil pollution, making the distinction between agricultural activities, industrial activities, and urbanization. Pollution from agricultural activities stems primarily from the excessive amounts of pesticides and fertilizers used on farmland, and is mainly located in the south, where most of the food is produced. Pollution from industrial activities is due to airborne industrial pollutants that fall on to the land, and is mainly located in the west of the country, where most manufacturing activities take place. Pollution from urbanization is mainly due to the very large amount of solid, liquid and gaseous waste generated in a small area with insufficient treatment facilities, and exhaust fumes from vehicles, and is located around the largest cities, or roads. The result is that one fifth of China’s farmland is polluted, and an area the size of Taiwan is so polluted that farming should not be allowed there at all.

  4. Modelling Watershed and Estuarine Controls on Salt Marsh Distributions

    Science.gov (United States)

    Yousefi Lalimi, F.; Marani, M.; Murray, A. B.; D'Alpaos, A.

    2017-12-01

    The formation and evolution of tidal platforms have been extensively studied through observations and models, describing landform dynamics as a result of the local interactions and feedbacks among hydrodynamics, vegetation, and sediment transport. However, existing work mainly focuses on individual marsh platforms and, possibly, their immediate surrounding, such that the influence and controls on marsh dynamics of inland areas (through fluvial inputs) and of exchanges with the ocean have not been comprehensively and simultaneously accounted for. Here, we develop and use a process-based model to evaluate the relative role of watershed, estuarine, and ocean controls on salt marsh accretionary and depositional/erosional dynamics and define how these factors interact to determine salt marsh resilience to environmental change at the whole-estuary scale. Our results, in line with previous work, show that no stable equilibrium exists for the erosional dynamics of the marsh/tidal flat boundary. In addition, we find that under some circumstances, vertical accretion/erosion dynamics can lead to transitions between salt marsh and tidal flat equilibrium states that occur much more rapidly than marsh/tidal flat boundary erosion or accretion could. We further define, in the multidimensional space of estuarine-scale morphodynamic forcings, the basins of attractions leading to marsh-dominated and tidal-flat-dominated estuaries. The relatively slow dynamics asymptotically leading to marsh- or tidal-flat- dominance in many cases suggest that estuaries are likely to be found, at any given time, in a transition state dictated by temporal variations in environmental forcings.

  5. Simulation of snow distribution and melt under cloudy conditions in an Alpine watershed

    Directory of Open Access Journals (Sweden)

    H.-Y. Li

    2011-07-01

    Full Text Available An energy balance method and remote-sensing data were used to simulate snow distribution and melt in an alpine watershed in northwestern China within a complete snow accumulation-melt period. The spatial energy budgets were simulated using meteorological observations and a digital elevation model of the watershed. A linear interpolation method was used to estimate the daily snow cover area under cloudy conditions, using Moderate Resolution Imaging Spectroradiometer (MODIS data. Hourly snow distribution and melt, snow cover extent and daily discharge were included in the simulated results. The root mean square error between the measured snow-water equivalent samplings and the simulated results is 3.2 cm. The Nash and Sutcliffe efficiency statistic (NSE between the measured and simulated discharges is 0.673, and the volume difference (Dv is 3.9 %. Using the method introduced in this article, modelling spatial snow distribution and melt runoff will become relatively convenient.

  6. Assessing groundwater pollution hazard changes under different socio-economic and environmental scenarios in an agricultural watershed

    Energy Technology Data Exchange (ETDEWEB)

    Lima, M. Lourdes, E-mail: mlima@mdp.edu.ar [Instituto de Geología de Costas y del Cuaternario, FCEyN, Universidad Nacional de Mar del Plata, Funes 3350, Nivel 1, 7600 Mar del Plata (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Romanelli, Asunción, E-mail: aromanel@mdp.edu.ar [Instituto de Geología de Costas y del Cuaternario, FCEyN, Universidad Nacional de Mar del Plata, Funes 3350, Nivel 1, 7600 Mar del Plata (Argentina); Instituto de Investigaciones Marinas y Costeras (IIMyC), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Massone, Héctor E., E-mail: hmassone@mdp.edu.ar [Instituto de Geología de Costas y del Cuaternario, FCEyN, Universidad Nacional de Mar del Plata, Funes 3350, Nivel 1, 7600 Mar del Plata (Argentina)

    2015-10-15

    This paper proposes a modeling approach for assessing changes in groundwater pollution hazard under two different socio-economic and environmental scenarios: The first one considers an exponential growth of agriculture land-use (Relegated Sustainability), while the other deals with regional economic growth, taking into account, the restrictions put on natural resources use (Sustainability Reforms). The recent (2011) and forecasted (2030) groundwater pollution hazard is evaluated based on hydrogeological parameters and, the impact of land-use changes in the groundwater system, coupling together a land-use change model (Dyna-CLUE) with a groundwater flow model (MODFLOW), as inputs to a decision system support (EMDS). The Dulce Stream Watershed (Pampa Plain, Argentina) was chosen to test the usefulness and utility of this proposed method. It includes a high level of agricultural activities, significant local extraction of groundwater resources for drinking water and irrigation and extensive available data regarding aquifer features. The Relegated Sustainability Scenario showed a negative change in the aquifer system, increasing (+ 20%; high–very high classes) the contribution to groundwater pollution hazard throughout the watershed. On the other hand, the Sustainability Reforms Scenario displayed more balanced land-use changes with a trend towards sustainability, therefore proposing a more acceptable change in the aquifer system for 2030 with a possible 2% increase (high–very high classes) in groundwater pollution hazard. Results in the recent scenario (2011) showed that 54% of Dulce Stream Watershed still shows a moderate to a very low contribution to groundwater pollution hazard (mainly in the lower area). Therefore, from the point of view of natural resource management, this is a positive aspect, offering possibilities for intervention in order to prevent deterioration and protect this aquifer system. However, since it is quite possible that this aquifer status

  7. Quantitative identification of nitrate pollution sources and uncertainty analysis based on dual isotope approach in an agricultural watershed.

    Science.gov (United States)

    Ji, Xiaoliang; Xie, Runting; Hao, Yun; Lu, Jun

    2017-10-01

    Quantitative identification of nitrate (NO 3 - -N) sources is critical to the control of nonpoint source nitrogen pollution in an agricultural watershed. Combined with water quality monitoring, we adopted the environmental isotope (δD-H 2 O, δ 18 O-H 2 O, δ 15 N-NO 3 - , and δ 18 O-NO 3 - ) analysis and the Markov Chain Monte Carlo (MCMC) mixing model to determine the proportions of riverine NO 3 - -N inputs from four potential NO 3 - -N sources, namely, atmospheric deposition (AD), chemical nitrogen fertilizer (NF), soil nitrogen (SN), and manure and sewage (M&S), in the ChangLe River watershed of eastern China. Results showed that NO 3 - -N was the main form of nitrogen in this watershed, accounting for approximately 74% of the total nitrogen concentration. A strong hydraulic interaction existed between the surface and groundwater for NO 3 - -N pollution. The variations of the isotopic composition in NO 3 - -N suggested that microbial nitrification was the dominant nitrogen transformation process in surface water, whereas significant denitrification was observed in groundwater. MCMC mixing model outputs revealed that M&S was the predominant contributor to riverine NO 3 - -N pollution (contributing 41.8% on average), followed by SN (34.0%), NF (21.9%), and AD (2.3%) sources. Finally, we constructed an uncertainty index, UI 90 , to quantitatively characterize the uncertainties inherent in NO 3 - -N source apportionment and discussed the reasons behind the uncertainties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Modeling urbanized watershed flood response changes with distributed hydrological model: key hydrological processes, parameterization and case studies

    Science.gov (United States)

    Chen, Y.

    2017-12-01

    Urbanization is the world development trend for the past century, and the developing countries have been experiencing much rapider urbanization in the past decades. Urbanization brings many benefits to human beings, but also causes negative impacts, such as increasing flood risk. Impact of urbanization on flood response has long been observed, but quantitatively studying this effect still faces great challenges. For example, setting up an appropriate hydrological model representing the changed flood responses and determining accurate model parameters are very difficult in the urbanized or urbanizing watershed. In the Pearl River Delta area, rapidest urbanization has been observed in China for the past decades, and dozens of highly urbanized watersheds have been appeared. In this study, a physically based distributed watershed hydrological model, the Liuxihe model is employed and revised to simulate the hydrological processes of the highly urbanized watershed flood in the Pearl River Delta area. A virtual soil type is then defined in the terrain properties dataset, and its runoff production and routing algorithms are added to the Liuxihe model. Based on a parameter sensitive analysis, the key hydrological processes of a highly urbanized watershed is proposed, that provides insight into the hydrological processes and for parameter optimization. Based on the above analysis, the model is set up in the Songmushan watershed where there is hydrological data observation. A model parameter optimization and updating strategy is proposed based on the remotely sensed LUC types, which optimizes model parameters with PSO algorithm and updates them based on the changed LUC types. The model parameters in Songmushan watershed are regionalized at the Pearl River Delta area watersheds based on the LUC types of the other watersheds. A dozen watersheds in the highly urbanized area of Dongguan City in the Pearl River Delta area were studied for the flood response changes due to

  9. Watershed model calibration framework developed using an influence coefficient algorithm and a genetic algorithm and analysis of pollutant discharge characteristics and load reduction in a TMDL planning area.

    Science.gov (United States)

    Cho, Jae Heon; Lee, Jong Ho

    2015-11-01

    Manual calibration is common in rainfall-runoff model applications. However, rainfall-runoff models include several complicated parameters; thus, significant time and effort are required to manually calibrate the parameters individually and repeatedly. Automatic calibration has relative merit regarding time efficiency and objectivity but shortcomings regarding understanding indigenous processes in the basin. In this study, a watershed model calibration framework was developed using an influence coefficient algorithm and genetic algorithm (WMCIG) to automatically calibrate the distributed models. The optimization problem used to minimize the sum of squares of the normalized residuals of the observed and predicted values was solved using a genetic algorithm (GA). The final model parameters were determined from the iteration with the smallest sum of squares of the normalized residuals of all iterations. The WMCIG was applied to a Gomakwoncheon watershed located in an area that presents a total maximum daily load (TMDL) in Korea. The proportion of urbanized area in this watershed is low, and the diffuse pollution loads of nutrients such as phosphorus are greater than the point-source pollution loads because of the concentration of rainfall that occurs during the summer. The pollution discharges from the watershed were estimated for each land-use type, and the seasonal variations of the pollution loads were analyzed. Consecutive flow measurement gauges have not been installed in this area, and it is difficult to survey the flow and water quality in this area during the frequent heavy rainfall that occurs during the wet season. The Hydrological Simulation Program-Fortran (HSPF) model was used to calculate the runoff flow and water quality in this basin. Using the water quality results, a load duration curve was constructed for the basin, the exceedance frequency of the water quality standard was calculated for each hydrologic condition class, and the percent reduction

  10. MOSSES AS BIOINDICATORS OF AIR POLLUTION ALONG AN URBAN–AGRICULTURAL TRANSECT IN THE CREDIT RIVER WATERSHED, SOUTHERN ONTARIO, CANADA

    Directory of Open Access Journals (Sweden)

    P. Cowden

    2015-04-01

    Full Text Available The activities associated with urbanization, such as vehicular traffic and industrial processes, lead to elevated emissions of atmospheric pollutants. Measuring the spatial extent of these pollutants is pivotal to identifying areas of concern and assessing mitigation measures. The objective of this study was to evaluate the relative deposition of heavy metals and nitrogen using moss species along an urban–agricultural transition in the Credit River Watershed, southern Ontario. Thirteen species of moss were collected from Sugar Maple (Acer saccharum dominated forest stands across the study area, with only one moss species (Atrichum altercristatum commonly occurring. Heavy metal concentrations were variable between species; the Coefficient of Variation (CV for the majority of metals (Al, V, Cr, Fe, Ni, As, Sb and Pb was greater than ~50% across species. Nonetheless, metals exhibited similar trends, with the highest concentrations for Fe, followed by Al > Zn > Cu > Pb > Cr > Ni > V > As > Cd > Sb > Hg across species. Heavy metal concentrations in Atrichum altercristatum exhibited lower variability between sites, with CV < 33% for most metals (Cu, Zn, As, Cd, Sb, Pb and Hg. Further, many metal concentrations were strongly correlated (e.g., Al, V, Cr, Fe, and As; r ≤ 0.90 suggesting common emission sources, such as wind blown dust from agricultural activities or vehicular traffic, both predominant throughout the watershed.

  11. Evaluation of antibiotic resistance analysis and ribotyping for identification of faecal pollution sources in an urban watershed.

    Science.gov (United States)

    Moore, D F; Harwood, V J; Ferguson, D M; Lukasik, J; Hannah, P; Getrich, M; Brownell, M

    2005-01-01

    The accuracy of ribotyping and antibiotic resistance analysis (ARA) for prediction of sources of faecal bacterial pollution in an urban southern California watershed was determined using blinded proficiency samples. Antibiotic resistance patterns and HindIII ribotypes of Escherichia coli (n = 997), and antibiotic resistance patterns of Enterococcus spp. (n = 3657) were used to construct libraries from sewage samples and from faeces of seagulls, dogs, cats, horses and humans within the watershed. The three libraries were analysed to determine the accuracy of host source prediction. The internal accuracy of the libraries (average rate of correct classification, ARCC) with six source categories was 44% for E. coli ARA, 69% for E. coli ribotyping and 48% for Enterococcus ARA. Each library's predictive ability towards isolates that were not part of the library was determined using a blinded proficiency panel of 97 E. coli and 99 Enterococcus isolates. Twenty-eight per cent (by ARA) and 27% (by ribotyping) of the E. coli proficiency isolates were assigned to the correct source category. Sixteen per cent were assigned to the same source category by both methods, and 6% were assigned to the correct category. Addition of 2480 E. coli isolates to the ARA library did not improve the ARCC or proficiency accuracy. In contrast, 45% of Enterococcus proficiency isolates were correctly identified by ARA. None of the methods performed well enough on the proficiency panel to be judged ready for application to environmental samples. Most microbial source tracking (MST) studies published have demonstrated library accuracy solely by the internal ARCC measurement. Low rates of correct classification for E. coli proficiency isolates compared with the ARCCs of the libraries indicate that testing of bacteria from samples that are not represented in the library, such as blinded proficiency samples, is necessary to accurately measure predictive ability. The library-based MST methods used in

  12. Evaluating spatial interaction of soil property with non-point source pollution at watershed scale: The phosphorus indicator in Northeast China

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang, Wei, E-mail: wei@itc.nl; Huang, Haobo; Hao, Fanghua; Shan, Yushu; Guo, Bobo

    2012-08-15

    To better understand the spatial dynamics of non-point source (NPS) phosphorus loading with soil property at watershed scale, integrated modeling and soil chemistry is crucial to ensure that the indicator is functioning properly and expressing the spatial interaction at two depths. Developments in distributed modeling have greatly enriched the availability of geospatial data analysis and assess the NPS pollution loading response to soil property over larger area. The 1.5 km-grid soil sampling at two depths was analyzed with eight parameters, which provided detailed spatial and vertical soil data under four main types of landuses. The impacts of landuse conversion and agricultural practice on soil property were firstly identified. Except for the slightly bigger total of potassium (TK) and cadmium (Cr), the other six parameters had larger content in 20-40 cm surface than the top 20 cm surface. The Soil and Water Assessment Tool was employed to simulate the loading of NPS phosphorus. Overlaying with the landuse distribution, it was found that the NPS phosphorus mainly comes from the subbasins dominated with upland and paddy rice. The linear correlations of eight soil parameters at two depths with NPS phosphorus loading in the subbasins of upland and paddy rice were compared, respectively. The correlations of available phosphorus (AP), total phosphorus (TP), total nitrogen (TN) and TK varied in two depths, and also can assess the loading. The soil with lower soil organic carbon (SOC) presented a significant higher risk for NPS phosphorus loading, especially in agricultural area. The Principal Component Analysis showed that the TP and zinc (Zn) in top soil and copper (Cu) and Cr in subsurface can work as indicators. The analysis suggested that the application of soil property indicators is useful for assessing NPS phosphorus loss, which is promising for water safety in agricultural area. -- Highlights: Black-Right-Pointing-Pointer Spatial dynamics of NPS phosphorus

  13. Evaluating spatial interaction of soil property with non‐point source pollution at watershed scale: The phosphorus indicator in Northeast China

    International Nuclear Information System (INIS)

    Ouyang, Wei; Huang, Haobo; Hao, Fanghua; Shan, Yushu; Guo, Bobo

    2012-01-01

    To better understand the spatial dynamics of non-point source (NPS) phosphorus loading with soil property at watershed scale, integrated modeling and soil chemistry is crucial to ensure that the indicator is functioning properly and expressing the spatial interaction at two depths. Developments in distributed modeling have greatly enriched the availability of geospatial data analysis and assess the NPS pollution loading response to soil property over larger area. The 1.5 km-grid soil sampling at two depths was analyzed with eight parameters, which provided detailed spatial and vertical soil data under four main types of landuses. The impacts of landuse conversion and agricultural practice on soil property were firstly identified. Except for the slightly bigger total of potassium (TK) and cadmium (Cr), the other six parameters had larger content in 20–40 cm surface than the top 20 cm surface. The Soil and Water Assessment Tool was employed to simulate the loading of NPS phosphorus. Overlaying with the landuse distribution, it was found that the NPS phosphorus mainly comes from the subbasins dominated with upland and paddy rice. The linear correlations of eight soil parameters at two depths with NPS phosphorus loading in the subbasins of upland and paddy rice were compared, respectively. The correlations of available phosphorus (AP), total phosphorus (TP), total nitrogen (TN) and TK varied in two depths, and also can assess the loading. The soil with lower soil organic carbon (SOC) presented a significant higher risk for NPS phosphorus loading, especially in agricultural area. The Principal Component Analysis showed that the TP and zinc (Zn) in top soil and copper (Cu) and Cr in subsurface can work as indicators. The analysis suggested that the application of soil property indicators is useful for assessing NPS phosphorus loss, which is promising for water safety in agricultural area. -- Highlights: ► Spatial dynamics of NPS phosphorus pollution with soil

  14. Distribution characteristics of volatile methylsiloxanes in Tokyo Bay watershed in Japan: Analysis of surface waters by purge and trap method.

    Science.gov (United States)

    Horii, Yuichi; Minomo, Kotaro; Ohtsuka, Nobutoshi; Motegi, Mamoru; Nojiri, Kiyoshi; Kannan, Kurunthachalam

    2017-05-15

    Surface waters including river water and effluent from sewage treatment plants (STPs) were collected from Tokyo Bay watershed, Japan, and analyzed for seven cyclic and linear volatile methylsiloxanes (VMSs), i.e., D3, D4, D5, D6, L3, L4, and L5 by an optimized purge and trap extraction method. The total concentrations of seven VMSs (ΣVMS) in river water ranged from watershed was estimated at 2300kg. Our results indicate widespread distribution of VMSs in Tokyo Bay watershed and the influence of domestic wastewater discharges as a source of VMSs in the aquatic environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Characterization and source identification of pollutants in runoff from a mixed land use watershed using ordination analyses.

    Science.gov (United States)

    Lee, Dong Hoon; Kim, Jin Hwi; Mendoza, Joseph A; Lee, Chang Hee; Kang, Joo-Hyon

    2016-05-01

    While identification of critical pollutant sources is the key initial step for cost-effective runoff management, it is challenging due to the highly uncertain nature of runoff pollution, especially during a storm event. To identify critical sources and their quantitative contributions to runoff pollution (especially focusing on phosphorous), two ordination methods were used in this study: principal component analysis (PCA) and positive matrix factorization (PMF). For the ordination analyses, we used runoff quality data for 14 storm events, including data for phosphorus, 11 heavy metal species, and eight ionic species measured at the outlets of subcatchments with different land use compositions in a mixed land use watershed. Five factors as sources of runoff pollutants were identified by PCA: agrochemicals, groundwater, native soils, domestic sewage, and urban sources (building materials and automotive activities). PMF identified similar factors to those identified by PCA, with more detailed source mechanisms for groundwater (i.e., nitrate leaching and cation exchange) and urban sources (vehicle components/motor oils/building materials and vehicle exhausts), confirming the sources identified by PCA. PMF was further used to quantify contributions of the identified sources to the water quality. Based on the results, agrochemicals and automotive activities were the two dominant and ubiquitous phosphorus sources (39-61 and 16-47 %, respectively) in the study area, regardless of land use types.

  16. Spatial distribution of water erosion risk in a watershed with eucalyptus and Atlantic Forest

    Directory of Open Access Journals (Sweden)

    Junior Cesar Avanzi

    2013-10-01

    Full Text Available The process of water erosion occurs in watersheds throughout the world and it is strongly affected by anthropogenic influences. Thus, the knowledge of these processes is extremely necessary for planning of conservation efforts. This study was performed in an experimental forested watershed in order to predict the average potential annual soil loss by water erosion using the Universal Soil Loss Equation (USLE and a Geographic Information System (GIS, and then compared with soil loss tolerance. All the USLE factors were generated in a distributed approach employing a GIS tool. The layers were multiplied in the GIS framework in order to predict soil erosion rates. Results showed that the average soil loss was 6.2 Mg ha-1 yr-1. Relative to soil loss tolerance, 83% of the area had an erosion rate lesser than the tolerable value. According to soil loss classes, 49% of the watershed had erosion less than 2.5 Mg ha-1 yr-1. However, about 8.7% of the watershed had erosion rates greater than 15 Mg ha-1 yr-1, being mainly related to Plinthosol soil class and roads, thus requiring special attention for the improvement of sustainable management practices for such areas. Eucalyptus cultivation was found to have soil loss greater than Atlantic Forest. Thus, an effort should be made to bring the erosion rates closer to the native forest. Implementation of the USLE model in a GIS framework was found to be a simple and useful tool for predicting the spatial variation of soil erosion risk and identifying critical areas for conservation efforts.

  17. Regional distribution and pollution evaluation of heavy metal pollution in topsoils of the Chengdu plain

    International Nuclear Information System (INIS)

    Li Bing; Wang Changquan; Yang Juan; Tan Ting; Li Huanxiu; Li Qiquan; Yuan Quan

    2009-01-01

    197 farm field samples were designated by GPS and the spatial distribution characteristic and pollution evaluation of Cd, Pb, Cr and Hg in the soils were studied. Compared to the background investigated 20 years ago, the content of Cd in Guanghan, Xindu, Qionglai increased 1, 1.26 and 2 times; respectively; and the content of Pb in Xinjin, Deyang, Guanghan, Xindu increased 1.1 and 3.3 times. However, the content of Cr and Hg in most regions changed much smaller. The results of Kriging interpolation analysis of the heavy metals showed that the content of Cd was grandly decreased followed with the direction from northeast to southwest, the content of other elements exhibited the regional characteristics. The geoaccumulation index was used to evaluate the heavy metals pollution and results indicated that nearly 50% of the soils was polluted by Pb and Cd in different degrees influenced by men activities. With the key contaminated area of Xindu, Guanghan, Xinjing, Deyang the pollution ranks of Pb in soils was in 1 to 4. The Cd pollution although small, but still ranks in 1 to 2 level, the pollution area was bigger, mainly distributed in Xindu, Deyang, Guanghan, Shuangliu, Xinjing, Pengzhou. Only a small number of samples was contaminated by Cr or Hg. (authors)

  18. Emerging pollutants in the Esmeraldas watershed in Ecuador: discharge and attenuation of emerging organic pollutants along the San Pedro-Guayllabamba-Esmeraldas rivers.

    Science.gov (United States)

    Voloshenko-Rossin, A; Gasser, G; Cohen, K; Gun, J; Cumbal-Flores, L; Parra-Morales, W; Sarabia, F; Ojeda, F; Lev, O

    2015-01-01

    Water quality characteristics and emerging organic pollutants were sampled along the San Pedro-Guayllabamba-Esmeraldas River and its main water pollution streams in the summer of 2013. The annual flow rate of the stream is 22 000 Mm(3) y(-1) and it collects the wastewater of Quito-Ecuador in the Andes and supplies drinking water to the city of Esmeraldas near the Pacific Ocean. The most persistent emerging pollutants were carbamazepine and acesulfame, which were found to be stable along the San Pedro-Guayllabamba-Esmeraldas River, whereas the concentration of most other organic emerging pollutants, such as caffeine, sulfamethoxazole, venlafaxine, O-desmethylvenlafaxine, and steroidal estrogens, was degraded to a large extent along the 300 km flow. The mass rate of the sum of cocaine and benzoylecgonine, its metabolite, was increased along the stream, which may be attributed to coca plantations and wild coca trees. This raises the possibility of using river monitoring as an indirect way to learn about changes in coca plantations in their watersheds. Several organic emerging pollutants, such as venlafaxine, carbamazepine, sulphamethoxazole, and benzoylecgonine, survived even the filtration treatment at the Esmeraldas drinking water system, though all except for benzoylecgonine are found below 20 ng L(-1), and are therefore not likely to cause adverse health effects. The research provides a way to compare drug consumption in a major Latin American city (Quito) and shows that the consumption of most sampled drugs (carbamazepine, venlafaxine, O-desmethylvenlafaxine, sulphamethoxazole, ethinylestradiol) was below their average consumption level in Europe, Israel, and North America.

  19. [Temporal-spatial distribution of agricultural diffuse nitrogen pollution and relationship with soil respiration and nitrification].

    Science.gov (United States)

    Wei, Ouyang; Cai, Guan-Qing; Huang, Hao-Bo; Geng, Xiao-Jun

    2014-06-01

    The soil respiration, nitrification and denitrification processes play an important role on soil nitrogen transformation and diffuse nitrogen loading. These processes are also the chains for soil circle. In this study, the Zhegao watershed located north of Chaohu Lake was selected to explore the interactions of these processes with diffuse nitrogen pollution. The BaPS (Barometric Process Separation) was applied to analyze the soil respiration, nitrification and denitrification processes in farmland and forest. The SWAT (Soil and Water Assessment Tool) simulated the temporal and spatial pattern of diffuse nitrogen loading. As the expanding of farmland and higher level of fertilization, the yearly mean loading of diffuse nitrogen increased sustainably from 1980-1995 to 1996-2012. The monthly loading in 1996-2012 was also higher than that in the period of 1980-1995, which closely related to the precipitation. The statistical analysis indicated that there was a significant difference between two periods. The yearly averaged loading of the whole watershed in 1996-2012 was 10.40 kg x hm(-2), which was 8.10 kg x hm(-2) in 1980-1995. The variance analysis demonstrated that there was also a big difference between the spatial distributions of two periods. The forest soil had much higher soil respiration than the farmland soil. But the farmland had higher nitrification and denitrification rates. The more intensive nitrogen transformation in the farmland contributed to the less diffuse nitrogen loading. As the nitrification rate of farmland was higher than denitrification rate, agricultural diffuse nitrate nitrogen loading would increase and organic nitrogen loading would reduce. The analysis of soil respiration, nitrification and denitrification is helpful for the study of soil nitrogen circle form the aspect of soil biology, which also benefits the control of agricultural diffuse nitrogen pollution.

  20. Predicting the spatial distribution of Lonicera japonica, based on species occurrence data from two watersheds in Western Kentucky and Tennessee

    Science.gov (United States)

    Dongjiao Liu; Hao Jiang; Robin Zhang; Kate S. He

    2011-01-01

    The spatial distribution of most invasive plants is poorly documented and studied. This project examined and compared the spatial distribution of a successful invasive plant, Japanese honeysuckle (Lonicera japonica), in two similar-sized but ecologically distinct watersheds in western Kentucky (Ledbetter Creek) and western Tennessee (Panther Creek)....

  1. Simulating land management options to reduce nitrate pollution in an agricultural watershed dominated by an alluvial aquifer.

    Science.gov (United States)

    Cerro, Itsasne; Antigüedad, Iñaki; Srinavasan, Raghavan; Sauvage, Sabine; Volk, Martin; Sanchez-Perez, José Miguel

    2014-01-01

    The study area (Alegria watershed, Basque Country, Northern Spain) considered here is influenced by an important alluvial aquifer that plays a significant role in nitrate pollution from agricultural land use and management practices. Nitrates are transported primarily from the soil to the river through the alluvial aquifer. The agricultural activity covers 75% of the watershed and is located in a nitrate-vulnerable zone. The main objective of the study was to find land management options for water pollution abatement by using model systems. In a first step, the SWAT model was applied to simulate discharge and nitrate load in stream flow at the outlet of the catchment for the period between October 2009 and June 2011. The LOADEST program was used to estimate the daily nitrate load from measured nitrate concentration. We achieved satisfactory simulation results for discharge and nitrate loads at monthly and daily time steps. The results revealed clear variations in the seasons: higher nitrate loads were achieved for winter (20,000 kg mo NO-N), and lower nitrate loads were simulated for the summer (model was used to evaluate the long-term effects of best management practices (BMPs) for a 50-yr period by maintaining actual agricultural practices, reducing fertilizer application by 20%, splitting applications (same total N but applied over the growing period), and reducing 20% of the applied fertilizer amount and splitting the fertilizer doses. The BMPs were evaluated on the basis of local experience and farmer interaction. Results showed that reducing fertilizer amounts by 20% could lead to a reduction of 50% of the number of days exceeding the nitrate concentration limit value (50 mg L) set by the European Water Framework Directive. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  2. Stormwater Runoff Pollutant Loading Distributions and Their Correlation with Rainfall and Catchment Characteristics in a Rapidly Industrialized City

    Science.gov (United States)

    Li, Dongya; Wan, Jinquan; Ma, Yongwen; Wang, Yan; Huang, Mingzhi; Chen, Yangmei

    2015-01-01

    Fast urbanization and industrialization in developing countries result in significant stormwater runoff pollution, due to drastic changes in land-use, from rural to urban. A three-year study on the stormwater runoff pollutant loading distributions of industrial, parking lot and mixed commercial and residential catchments was conducted in the Tongsha reservoir watershed of Dongguan city, a typical, rapidly industrialized urban area in China. This study presents the changes in concentration during rainfall events, event mean concentrations (EMCs) and event pollution loads per unit area (EPLs). The first flush criterion, namely the mass first flush ratio (MFFn), was used to identify the first flush effects. The impacts of rainfall and catchment characterization on EMCs and pollutant loads percentage transported by the first 40% of runoff volume (FF40) were evaluated. The results indicated that the pollutant wash-off process of runoff during the rainfall events has significant temporal and spatial variations. The mean rainfall intensity (I), the impervious rate (IMR) and max 5-min intensity (Imax5) are the critical parameters of EMCs, while Imax5, antecedent dry days (ADD) and rainfall depth (RD) are the critical parameters of FF40. Intercepting the first 40% of runoff volume can remove 55% of TSS load, 53% of COD load, 58% of TN load, and 61% of TP load, respectively, according to all the storm events. These results may be helpful in mitigating stormwater runoff pollution for many other urban areas in developing countries. PMID:25774922

  3. Stormwater runoff pollutant loading distributions and their correlation with rainfall and catchment characteristics in a rapidly industrialized city.

    Science.gov (United States)

    Li, Dongya; Wan, Jinquan; Ma, Yongwen; Wang, Yan; Huang, Mingzhi; Chen, Yangmei

    2015-01-01

    Fast urbanization and industrialization in developing countries result in significant stormwater runoff pollution, due to drastic changes in land-use, from rural to urban. A three-year study on the stormwater runoff pollutant loading distributions of industrial, parking lot and mixed commercial and residential catchments was conducted in the Tongsha reservoir watershed of Dongguan city, a typical, rapidly industrialized urban area in China. This study presents the changes in concentration during rainfall events, event mean concentrations (EMCs) and event pollution loads per unit area (EPLs). The first flush criterion, namely the mass first flush ratio (MFFn), was used to identify the first flush effects. The impacts of rainfall and catchment characterization on EMCs and pollutant loads percentage transported by the first 40% of runoff volume (FF40) were evaluated. The results indicated that the pollutant wash-off process of runoff during the rainfall events has significant temporal and spatial variations. The mean rainfall intensity (I), the impervious rate (IMR) and max 5-min intensity (Imax5) are the critical parameters of EMCs, while Imax5, antecedent dry days (ADD) and rainfall depth (RD) are the critical parameters of FF40. Intercepting the first 40% of runoff volume can remove 55% of TSS load, 53% of COD load, 58% of TN load, and 61% of TP load, respectively, according to all the storm events. These results may be helpful in mitigating stormwater runoff pollution for many other urban areas in developing countries.

  4. Monitoring and Analysis of Nonpoint Source Pollution - Case study on terraced paddy fields in an agricultural watershed

    Science.gov (United States)

    Chen, Shih-Kai; Jang, Cheng-Shin; Yeh, Chun-Lin

    2013-04-01

    The intensive use of chemical fertilizer has negatively impacted environments in recent decades, mainly through water pollution by nitrogen (N) and phosphate (P) originating from agricultural activities. As a main crop with the largest cultivation area about 0.25 million ha per year in Taiwan, rice paddies account for a significant share of fertilizer consumption among agriculture crops. This study evaluated the fertilization of paddy fields impacting return flow water quality in an agricultural watershed located at Hsinchu County, northern Taiwan. Water quality monitoring continued for two crop-periods in 2012, around subject to different water bodies, including the irrigation water, drainage water, and shallow groundwater. The results indicated that obviously increasing of ammonium-N, nitrate-N and TP concentrations in the surface drainage water were observed immediately following three times of fertilizer applications (including basal, tillering, and panicle fertilizer application), but reduced to relatively low concentrations after 7-10 days after each fertilizer application. Groundwater quality monitoring showed that the observation wells with the more shallow water depth, the more significant variation of concentrations of ammonium-N, nitrate-N and TP could be observed, which means that the contamination potential of nutrient of groundwater is related not only to the impermeable plow sole layer but also to the length of percolation route in this area. The study also showed that the potential pollution load of nutrient could be further reduced by well drainage water control and rational fertilizer management, such as deep-water irrigation, reuse of return flow, the rational application of fertilizers, and the SRI (The System of Rice Intensification) method. The results of this study can provide as an evaluation basis to formulate effective measures for agricultural non-point source pollution control and the reuse of agricultural return flow. Keywords

  5. Development of a distributed air pollutant dry deposition modeling framework

    International Nuclear Information System (INIS)

    Hirabayashi, Satoshi; Kroll, Charles N.; Nowak, David J.

    2012-01-01

    A distributed air pollutant dry deposition modeling system was developed with a geographic information system (GIS) to enhance the functionality of i-Tree Eco (i-Tree, 2011). With the developed system, temperature, leaf area index (LAI) and air pollutant concentration in a spatially distributed form can be estimated, and based on these and other input variables, dry deposition of carbon monoxide (CO), nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ), and particulate matter less than 10 microns (PM10) to trees can be spatially quantified. Employing nationally available road network, traffic volume, air pollutant emission/measurement and meteorological data, the developed system provides a framework for the U.S. city managers to identify spatial patterns of urban forest and locate potential areas for future urban forest planting and protection to improve air quality. To exhibit the usability of the framework, a case study was performed for July and August of 2005 in Baltimore, MD. - Highlights: ► A distributed air pollutant dry deposition modeling system was developed. ► The developed system enhances the functionality of i-Tree Eco. ► The developed system employs nationally available input datasets. ► The developed system is transferable to any U.S. city. ► Future planting and protection spots were visually identified in a case study. - Employing nationally available datasets and a GIS, this study will provide urban forest managers in U.S. cities a framework to quantify and visualize urban forest structure and its air pollution removal effect.

  6. Advanced airflow distribution methods for reducing exposure of indoor pollution

    DEFF Research Database (Denmark)

    Cao, Guangyu; Nielsen, Peter Vilhelm; Melikov, Arsen

    2017-01-01

    The adverse effect of various indoor pollutants on occupants’ health have been recognized. In public spaces flu viruses may spread from person to person by airflow generated by various traditional ventilation methods, like natural ventilation and mixing ventilation (MV Personalized ventilation (PV......) supplies clean air close to the occupant and directly into the breathing zone. Studies show that it improves the inhaled air quality and reduces the risk of airborne cross-infection in comparison with total volume (TV) ventilation. However, it is still challenging for PV and other advanced air distribution...... methods to reduce the exposure to gaseous and particulate pollutants under disturbed conditions and to ensure thermal comfort at the same time. The objective of this study is to analyse the performance of different advanced airflow distribution methods for protection of occupants from exposure to indoor...

  7. Advanced airflow distribution methods for reducing exposure of indoor pollution

    DEFF Research Database (Denmark)

    Cao, Guangyu; Nielsen, Peter Vilhelm; Melikov, Arsen Krikor

    methods to reduce the exposure to gaseous and particulate pollutants under disturbed conditions and to ensure thermal comfort at the same time. The objective of this study is to analyse the performance of different advanced airflow distribution methods for protection of occupants from exposure to indoor......The adverse effect of various indoor pollutants on occupants’ health have been recognized. In public spaces flu viruses may spread from person to person by airflow generated by various traditional ventilation methods, like natural ventilation and mixing ventilation (MV Personalized ventilation (PV......) supplies clean air close to the occupant and directly into the breathing zone. Studies show that it improves the inhaled air quality and reduces the risk of airborne cross-infection in comparison with total volume (TV) ventilation. However, it is still challenging for PV and other advanced air distribution...

  8. The Spatiotemporal Distribution of Two Bacterial Indexes in a Small Tibetan Plateau Watershed

    Directory of Open Access Journals (Sweden)

    Tongtong Zhao

    2017-10-01

    Full Text Available Microbial contamination is now more common than chemical contamination in Tibet, and water-borne microbes can cause a number of diseases that threaten public health. Thus, in order to clarify the spatiotemporal distribution of bacteria in small watersheds for which there is no data in Tibet, four sampling points were set up along an upstream-downstream transect of the Xincang River Basin. A total of 239 water samples were collected in 2014 and 2015, and their total constituent numbers of bacteria (TB and coliforms (TC were evaluated. The results of this study show that the microbial contamination of the Xincang River Basin is mild-to-moderate in terms of TB and TC contents, and that these concentrations vary significantly in different seasons. The results show that in summer, TB and TC concentrations and microbial contamination are almost at the same level in upstream, midstream, and downstream sections; however, in the other three seasons, microbial contamination in the downstream section is more serious than in the upstream and midstream sections. The data also demonstrates that concentrated precipitation and local contamination sources are important factors underlying increases in TB and TC concentrations during the summer months. The results of this study are likely to reflect the basic characteristics of small watersheds for which there is no data to some extent, and are thus of significant practical importance for protecting their ecological environments and promoting sustainable development.

  9. Large-watershed flood simulation and forecasting based on different-resolution distributed hydrological model

    Science.gov (United States)

    Li, J.

    2017-12-01

    Large-watershed flood simulation and forecasting is very important for a distributed hydrological model in the application. There are some challenges including the model's spatial resolution effect, model performance and accuracy and so on. To cope with the challenge of the model's spatial resolution effect, different model resolution including 1000m*1000m, 600m*600m, 500m*500m, 400m*400m, 200m*200m were used to build the distributed hydrological model—Liuxihe model respectively. The purpose is to find which one is the best resolution for Liuxihe model in Large-watershed flood simulation and forecasting. This study sets up a physically based distributed hydrological model for flood forecasting of the Liujiang River basin in south China. Terrain data digital elevation model (DEM), soil type and land use type are downloaded from the website freely. The model parameters are optimized by using an improved Particle Swarm Optimization(PSO) algorithm; And parameter optimization could reduce the parameter uncertainty that exists for physically deriving model parameters. The different model resolution (200m*200m—1000m*1000m ) are proposed for modeling the Liujiang River basin flood with the Liuxihe model in this study. The best model's spatial resolution effect for flood simulation and forecasting is 200m*200m.And with the model's spatial resolution reduction, the model performance and accuracy also become worse and worse. When the model resolution is 1000m*1000m, the flood simulation and forecasting result is the worst, also the river channel divided based on this resolution is differs from the actual one. To keep the model with an acceptable performance, minimum model spatial resolution is needed. The suggested threshold model spatial resolution for modeling the Liujiang River basin flood is a 500m*500m grid cell, but the model spatial resolution with a 200m*200m grid cell is recommended in this study to keep the model at a best performance.

  10. Organic pollutant levels in an agricultural watershed: the importance of analyzing multiple matrices for assessing stream water pollution.

    Science.gov (United States)

    Gonzalez, Mariana; Miglioranza, Karina S B; Grondona, Sebastían I; Silva Barni, Maria Florencia; Martinez, Daniel E; Peña, Aránzazu

    2013-04-01

    This study is aimed at analyzing the occurrence and transport of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the Quequén Grande river basin, as representative of a catchment under diffuse pollution sources. Pollutant levels in soils, river bottom sediments (RBS), streamwater (Sw), suspended particle materials (SPMs), macrophytes and muscle of silverside were determined by GC-ECD. Soil K(d) values for the current-used insecticides, endosulfans and cypermethrin, were established. Total levels (ng g(-1) dry weight) in soil ranged between 0.07–0.9 for OCPs, 0.03–0.37 for PCBs and 0.01–0.05 for PBDEs. Endosulfan insecticide (α- + b- + sulfate metabolite) represented up to 72.5% of OCPs. The low soil retention for α-endosulfan (K(d): 77) and endosulfan sulfate (K(d): 100) allows their transport to Sw, SPM and RBS. Levels of endosulfan in Sw in some cases exceeded the value postulated by international guidelines for aquatic biota protection (3 ng L(-1)). PCB and PBDE pollution was related to harbour, dumping sites and pile tire burning. Tri and hexa PCB congeners predominated in all matrices and exceeded the quality guideline value of 0.04 ng L(-1) in Sw. Considering levels in silverside muscle, none of the oral reference doses were exceeded, however, PCBs accounted for 18.6% of the total daily allowed ingest for a 70 kg individual. Although the levels of PCBs and OCPs in soil and RBS were low and did not go beyond quality guidelines, these compounds could still represent a risk to aquatic biota and humanbeings, and thus actions towards preventing this situation should be undertaken.

  11. Sediment–water distribution of contaminants of emerging concern in a mixed use watershed

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, David J., E-mail: david.fairbairn@state.mn.us [University of Minnesota, Water Resources Center, 1985 Buford Ave., St Paul, MN 55108 (United States); Karpuzcu, M. Ekrem [University of Minnesota, Water Resources Center, 1985 Buford Ave., St Paul, MN 55108 (United States); Arnold, William A. [University of Minnesota, Civil, Environmental, and Geo-Engineering, 500 Pillsbury Drive SE, Minneapolis, MN 55455 (United States); Barber, Brian L. [University of Minnesota, Department of Soil, Water, and Climate, 1902 Dudley Ave, Saint Paul, MN 55108 (United States); Kaufenberg, Elizabeth F. [University of Minnesota, Water Resources Center, 1985 Buford Ave., St Paul, MN 55108 (United States); Koskinen, William C. [United States Department of Agriculture, Agricultural Research Service, 1991 Upper Buford Circle, University of Minnesota, Saint Paul, MN 55108 (United States); Novak, Paige J. [University of Minnesota, Civil, Environmental, and Geo-Engineering, 500 Pillsbury Drive SE, Minneapolis, MN 55455 (United States); Rice, Pamela J. [United States Department of Agriculture, Agricultural Research Service, 1991 Upper Buford Circle, University of Minnesota, Saint Paul, MN 55108 (United States); Swackhamer, Deborah L. [University of Minnesota, Water Resources Center, 1985 Buford Ave., St Paul, MN 55108 (United States)

    2015-02-01

    This study evaluated the occurrence and distribution of 15 contaminants of emerging concern (CECs) in stream water and sediments in the Zumbro River watershed in Minnesota and compared these with sub-watershed land uses. Sixty pairs of sediment and water samples were collected across all seasons from four stream sites for over two years and analyzed for selected personal care products, pesticides, human and veterinary medications, and phytoestrogens. Spatial and temporal analyses indicate that pharmaceuticals and personal care products (urban/residential CECs) are significantly elevated in water and/or sediment at sites with greater population density (> 100 people/km{sup 2}) and percentage of developed land use (> 8% of subwatershed area) than those with less population density and land area under development. Significant spatial variations of agricultural pesticides in water and sediment were detectable, even though all sites had a high percentage of agricultural land use. Seasonality in CEC concentration was observed in water but not in sediment, although sediment concentrations of three CECs did vary between years. Average measured non-equilibrium distribution coefficients exceeded equilibrium hydrophobic partitioning-based predictions for 5 of the 7 detected CECs by at least an order of magnitude. Agreement of measured and predicted distribution coefficients improved with increasing hydrophobicity and in-stream persistence. The more polar and degradable CECs showed greater variability in measured distributions across different sampling events. Our results confirm that CECs are present in urban and agricultural stream sediments, including those CECs that would typically be thought of as non-sorptive based on their log K{sub ow} values. These results and the observed patterns of sediment and water distributions augment existing information to improve prediction of CEC fate and transport, leading to more accurate assessments of exposure and risk to surface water

  12. Modeling the impacts of wildfire on runoff and pollutant transport from coastal watersheds to the nearshore environment.

    Science.gov (United States)

    Morrison, Katherine D; Kolden, Crystal A

    2015-03-15

    Wildfire is a common disturbance that can significantly alter vegetation in watersheds and affect the rate of sediment and nutrient transport to adjacent nearshore oceanic environments. Changes in runoff resulting from heterogeneous wildfire effects are not well-understood due to both limitations in the field measurement of runoff and temporally-limited spatial data available to parameterize runoff models. We apply replicable, scalable methods for modeling wildfire impacts on sediment and nonpoint source pollutant export into the nearshore environment, and assess relationships between wildfire severity and runoff. Nonpoint source pollutants were modeled using a GIS-based empirical deterministic model parameterized with multi-year land cover data to quantify fire-induced increases in transport to the nearshore environment. Results indicate post-fire concentration increases in phosphorus by 161 percent, sediments by 350 percent and total suspended solids (TSS) by 53 percent above pre-fire years. Higher wildfire severity was associated with the greater increase in exports of pollutants and sediment to the nearshore environment, primarily resulting from the conversion of forest and shrubland to grassland. This suggests that increasing wildfire severity with climate change will increase potential negative impacts to adjacent marine ecosystems. The approach used is replicable and can be utilized to assess the effects of other types of land cover change at landscape scales. It also provides a planning and prioritization framework for management activities associated with wildfire, including suppression, thinning, and post-fire rehabilitation, allowing for quantification of potential negative impacts to the nearshore environment in coastal basins. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Minnesota Watersheds

    Data.gov (United States)

    Minnesota Department of Natural Resources — Statewide minor watershed delineations with major/minor watershed identifiers and names for provinces, major watersheds, and basins. Also included are watershed...

  14. Identifying fecal pollution sources using 3M(™) Petrifilm (™) count plates and antibiotic resistance analysis in the Horse Creek Watershed in Aiken County, SC (USA).

    Science.gov (United States)

    Harmon, S Michele; West, Ryan T; Yates, James R

    2014-12-01

    Sources of fecal coliform pollution in a small South Carolina (USA) watershed were identified using inexpensive methods and commonly available equipment. Samples from the upper reaches of the watershed were analyzed with 3M(™) Petrifilm(™) count plates. We were able to narrow down the study's focus to one particular tributary, Sand River, that was the major contributor of the coliform pollution (both fecal and total) to a downstream reservoir that is heavily used for recreation purposes. Concentrations of total coliforms ranged from 2,400 to 120,333 cfu/100 mL, with sharp increases in coliform counts observed in samples taken after rain events. Positive correlations between turbidity and fecal coliform counts suggested a relationship between fecal pollution and stormwater runoff. Antibiotic resistance analysis (ARA) compared antibiotic resistance profiles of fecal coliform isolates from the stream to those of a watershed-specific fecal source library (equine, waterfowl, canines, and untreated sewage). Known fecal source isolates and unknown isolates from the stream were exposed to six antibiotics at three concentrations each. Discriminant analysis grouped known isolates with an overall average rate of correct classification (ARCC) of 84.3 %. A total of 401 isolates from the first stream location were classified as equine (45.9 %), sewage (39.4 %), waterfowl (6.2 %), and feline (8.5 %). A similar pattern was observed at the second sampling location, with 42.6 % equine, 45.2 % sewage, 2.8 % waterfowl, 0.6 % canine, and 8.8 % feline. While there were slight weather-dependent differences, the vast majority of the coliform pollution in this stream appeared to be from two sources, equine and sewage. This information will contribute to better land use decisions and further justify implementation of low-impact development practices within this urban watershed.

  15. Agricultural non-point source pollution management in a reservoir watershed based on ecological network analysis of soil nitrogen cycling.

    Science.gov (United States)

    Xu, Wen; Cai, Yanpeng; Rong, Qiangqiang; Yang, Zhifeng; Li, Chunhui; Wang, Xuan

    2018-03-01

    The Miyun Reservoir plays a pivotal role in providing drinking water for the city of Beijing. In this research, ecological network analysis and scenario analysis were integrated to explore soil nitrogen cycling of chestnut and Chinese pine forests in the upper basin of the Miyun Reservoir, as well as to seek favorable fertilization modes to reduce agricultural non-point source pollution. Ecological network analysis results showed that (1) the turnover time was 0.04 to 0.37 year in the NH 4 + compartment and were 15.78 to 138.36 years in the organic N compartment; (2) the Finn cycling index and the ratio of indirect to direct flow were 0.73 and 11.92 for the chestnut forest model, respectively. Those of the Chinese pine forest model were 0.88 and 29.23, respectively; and (3) in the chestnut forest model, NO 3 - accounted for 96% of the total soil nitrogen loss, followed by plant N (2%), NH 4 + (1%), and organic N (1%). In the Chinese pine forest, NH 4 + accounted for 56% of the total soil nitrogen loss, followed by organic N (34%) and NO 3 - (10%). Fertilization mode was identified as the main factor affecting soil N export. To minimize NH 4 + and NO 3 - outputs while maintaining the current plant yield (i.e., 7.85e0 kg N/year), a fertilization mode of 162.50 kg N/year offered by manure should be adopted. Whereas, to achieve a maximum plant yield (i.e., 3.35e1 kg N/year) while reducing NH 4 + and NO 3 - outputs, a fertilization mode of 325.00 kg N/year offered by manure should be utilized. This research is of wide suitability to support agricultural non-point source pollution management at the watershed scale.

  16. Distributed snow modeling suitable for use with operational data for the American River watershed.

    Science.gov (United States)

    Shamir, E.; Georgakakos, K. P.

    2004-12-01

    The mountainous terrain of the American River watershed (~4300 km2) at the Western slope of the Northern Sierra Nevada is subject to significant variability in the atmospheric forcing that controls the snow accumulation and ablations processes (i.e., precipitation, surface temperature, and radiation). For a hydrologic model that attempts to predict both short- and long-term streamflow discharges, a plausible description of the seasonal and intermittent winter snow pack accumulation and ablation is crucial. At present the NWS-CNRFC operational snow model is implemented in a semi distributed manner (modeling unit of about 100-1000 km2) and therefore lump distinct spatial variability of snow processes. In this study we attempt to account for the precipitation, temperature, and radiation spatial variability by constructing a distributed snow accumulation and melting model suitable for use with commonly available sparse data. An adaptation of the NWS-Snow17 energy and mass balance that is used operationally at the NWS River Forecast Centers is implemented at 1 km2 grid cells with distributed input and model parameters. The input to the model (i.e., precipitation and surface temperature) is interpolated from observed point data. The surface temperature was interpolated over the basin based on adiabatic lapse rates using topographic information whereas the precipitation was interpolated based on maps of climatic mean annual rainfall distribution acquired from PRISM. The model parameters that control the melting rate due to radiation were interpolated based on aspect. The study was conducted for the entire American basin for the snow seasons of 1999-2000. Validation of the Snow Water Equivalent (SWE) prediction is done by comparing to observation from 12 snow Sensors. The Snow Cover Area (SCA) prediction was evaluated by comparing to remotely sensed 500m daily snow cover derived from MODIS. The results that the distribution of snow over the area is well captured and the

  17. Yosemite Hydroclimate Network: Distributed stream and atmospheric data for the Tuolumne River watershed and surroundings

    Science.gov (United States)

    Lundquist, Jessica D.; Roche, James W.; Forrester, Harrison; Moore, Courtney; Keenan, Eric; Perry, Gwyneth; Cristea, Nicoleta; Henn, Brian; Lapo, Karl; McGurk, Bruce; Cayan, Daniel R.; Dettinger, Michael D.

    2016-01-01

    Regions of complex topography and remote wilderness terrain have spatially varying patterns of temperature and streamflow, but due to inherent difficulties of access, are often very poorly sampled. Here we present a data set of distributed stream stage, streamflow, stream temperature, barometric pressure, and air temperature from the Tuolumne River Watershed in Yosemite National Park, Sierra Nevada, California, USA, for water years 2002–2015, as well as a quality-controlled hourly meteorological forcing time series for use in hydrologic modeling. We also provide snow data and daily inflow to the Hetch Hetchy Reservoir for 1970–2015. This paper describes data collected using low-visibility and low-impact installations for wilderness locations and can be used alone or as a critical supplement to ancillary data sets collected by cooperating agencies, referenced herein. This data set provides a unique opportunity to understand spatial patterns and scaling of hydroclimatic processes in complex terrain and can be used to evaluate downscaling techniques or distributed modeling. The paper also provides an example methodology and lessons learned in conducting hydroclimatic monitoring in remote wilderness.

  18. Sacaton riparian grasslands of the Sky Islands: Mapping distribution and ecological condition using state-and-transition models in Upper Cienega Creek Watershed

    Science.gov (United States)

    Ron Tiller; Melissa Hughes; Gita Bodner

    2013-01-01

    Riparian grasslands dominated by Sporobolus wrightii (big sacaton) were once widely distributed in the intermountain basins of the Madrean Archipelago. These alluvial grasslands are still recognized as key resources for watershed function, livestock, and wildlife. The upper Cienega Creek watershed in SE Arizona is thought to harbor some of the region’s most extensive...

  19. Metamodeling as a tool to size vegetative filter strips for surface runoff pollution control in European watersheds.

    Science.gov (United States)

    Lauvernet, Claire; Muñoz-Carpena, Rafael; Carluer, Nadia

    2015-04-01

    In Europe, a significant presence of contaminants is found in surface water, partly due to pesticide applications. Vegetative filter strips or buffer zones (VFS), often located along rivers, are a common best management practice (BMP) to reduce non point source pollution of water by reducing surface runoff. However, they need to be adapted to the agro-ecological and climatic conditions, both in terms of position and size, in order to be efficient. The TOPPS-PROWADIS project involves European experts and stakeholders to develop and recommend BMPs to reduce pesticide transfer by drift or runoff in several European countries. In this context, IRSTEA developed a guide accompanying the use of different tools, which allows designing site-specific VFS by simulating their efficiency to limit transfers using the mechanistic model VFSMOD. This method which is very complete assumes that the user provides detailed field knowledge and data, which are not always easily available. The aim of this study is to assist the buffer sizing by using a unique tool with a reduced set of parameters, adapted to the available information from the end-users. In order to fill in the lack of real data in many practical applications, a set of virtual scenarios was selected to encompass a large range of agro-pedo-climatic conditions in Europe, considering both the upslope agricultural field and the VFS characteristics. As a first step first, in this work we present scenarios based on North-West of France climate consisting of different rainfall intensities and durations, hillslope lengths and slopes, humidity conditions, a large set of field rainfall/runoff characteristics for the contributing area, and several shallow water table depths and soil types for the VFS. The sizing method based on the mechanistic model VFSMOD was applied for all these scenarios, and a global sensitivity analysis (GSA) of the VFS optimal length was performed for all the input parameters in order to understand their

  20. The probability distribution model of air pollution index and its dominants in Kuala Lumpur

    Science.gov (United States)

    AL-Dhurafi, Nasr Ahmed; Razali, Ahmad Mahir; Masseran, Nurulkamal; Zamzuri, Zamira Hasanah

    2016-11-01

    This paper focuses on the statistical modeling for the distributions of air pollution index (API) and its sub-indexes data observed at Kuala Lumpur in Malaysia. Five pollutants or sub-indexes are measured including, carbon monoxide (CO); sulphur dioxide (SO2); nitrogen dioxide (NO2), and; particulate matter (PM10). Four probability distributions are considered, namely log-normal, exponential, Gamma and Weibull in search for the best fit distribution to the Malaysian air pollutants data. In order to determine the best distribution for describing the air pollutants data, five goodness-of-fit criteria's are applied. This will help in minimizing the uncertainty in pollution resource estimates and improving the assessment phase of planning. The conflict in criterion results for selecting the best distribution was overcome by using the weight of ranks method. We found that the Gamma distribution is the best distribution for the majority of air pollutants data in Kuala Lumpur.

  1. Air Pollutant Distribution and Mesoscale Circulation Systems During Escompte

    Science.gov (United States)

    Kottmeier, Ch.; Kalthoff, N.; Corsmeier, U.; Robin, D.; Thürauf, J.; Hofherr, T.; Hasel, M.

    The distribution of pollutants observed with an Dornier 128 instrumented aircraft and from AIRMARAIX ground stations during one day of the Escompte experiment (June 25, 2001) is analysed in relation to the mesoscale wind systems and vertical mixing from aircraft and radiosonde data. The ESCOMPTE-experiment (http://medias.obs- mip.fr/escompte) was carried out in June and July 2001 in the urban area of Marseille and its rural surroundings to investigate periods with photosmog conditions. The over- all aim is to produce an appropriate high quality 3-D data set which includes emission, meteorological, and chemical data. The data is used for the validation of mesoscale models and for chemical and meteorological process studies. The evolution of pho- tosmog episodes with high ozone concentrations depends on both chemical transfor- mation processes and meteorological conditions. As Marseille is situated between the Mediterranean Sea in the south and mountainous sites in the north, under weak large- scale flow the meteorological conditions are dominated by thermally driven circula- tion systems which strongly influence the horizontal transport of air pollutants. Ad- ditionally, vertically exchange processes like mountain venting and slope winds may contribute in the temporal evolution of the trace gas concentration of the city plume in the atmospheric boundary layer and are particularly studied by the Dornier flight measurements. Therefore the experiment was designed to measure both, the chemi- cal species and meteorological parameters with high resolution in space and time by surface stations, aircraft and vertical profiling systems like radiosondes, sodars and lidars. Results are shown (a) on the evolution of the wind field and the ozone concen- trations during June 25, when an ozone maximum develops about 60 km in the lee site of Marseille and (b) the vertical transport of air pollutants between the boundary layer and the free troposphere.

  2. Diversity and Distribution of Aquatic Insects in Streams of the Mae Klong Watershed, Western Thailand

    Directory of Open Access Journals (Sweden)

    Witwisitpong Maneechan

    2015-01-01

    Full Text Available The distribution and diversity of aquatic insects and water quality variables were studied among three streams of the Mae Klong Watershed. In each stream, two sites were sampled. Aquatic insects and water quality variables were randomly sampled seven times in February, May, September, and December 2010 and in January, April, and May 2011. Overall, 11,153 individuals belonging to 64 families and nine orders were examined. Among the aquatic insects collected from the three streams, the order Trichoptera was most diverse in number of individuals, followed by Ephemeroptera, Hemiptera, Odonata, Coleoptera, Diptera, Plecoptera, Megaloptera, and Lepidoptera. The highest Shannon index of diversity of 2.934 and 3.2 was recorded in Huai Kayeng stream and the lowest was in Huai Pakkok stream (2.68 and 2.62. The high diversity of insect fauna in streams is an indication of larger microhabitat diversity and better water quality conditions prevailing in the streams. The evenness value was recorded as high in most sites. The high species diversity and evenness in almost all sites indicated good water quality.

  3. Lead contamination in a wetland watershed: isotopes as fingerprints of pollution

    International Nuclear Information System (INIS)

    Marcantonio, F.; Flowers, G.C.; Templin, N.

    2000-01-01

    The Pb-isotope composition of soils and sediments has been measured from both highly contaminated and non-contaminated regions of Bayou Trepagnier, a bayou in southern Louisiana that has had oil refinery effluent discharged into it over the past 66 years. Spoil banks created by the dredging of the bayou bottom approximately 50 years ago are the main source of contamination within the ecosystem. The 206 Pb/ 207 Pb isotope composition of the contaminant is relatively constant averaging 1.275±0.008. A literature search reveals that such radiogenic values are typical of ores from southeastern Missouri. When surficial soil 206 Pb/ 208 Pb and 206 Pb/ 207 Pb isotope ratios are plotted against each other, a straight line is defined (r 2 =0.99). The linear correlation suggests mixing between Pb from the spoil banks and Pb from a natural source. The latter source may consist of Pb in soil that has been leached of its natural radiogenic component during weathering processes. Mixing calculations indicate that transport of contaminant Pb is widespread and occurs several hundred meters from the spoil banks. Despite the low Pb concentrations of some of the soils, the isotope data demonstrate that a significant amount of the Pb is derived from the pollutant source. (orig.)

  4. Distribution of pollutant transport at landfill site, Taiping, Perak, Malaysia

    International Nuclear Information System (INIS)

    Roslanzairi Mostapa; Kamarudin Samuding; Mohd Tadza Abdul Rahman; Mohd Rifaie Mohd Murtadza; Ismail Abustan; Mohd Suhaimi Hamzah; Shamsiah Abdul Rahman; Nazaratul Ashifa Abdullah Salim

    2004-01-01

    This paper describes the preliminary report on the distribution of pollutant transport at Taiping municipal waste disposal site, Perak. This study involved the sampling of surface water and groundwater at various locations within the area. The hydrogeochemical method was used to determine the concentration of heavy metals i.e. Cr, Mn, Zn, As, Cd, Pb, and Fe. In-situ conductivity measurement was taken as a screening method for preliminary analysis purpose. Most of the groundwater at several boreholes contains high concentration of heavy metals. This indicates that some of the groundwater has been contaminated. The presence of heavy metals concentration in the surface water (river and pond) seems to be relatively low compared to maximum contaminant level (MCL) allowed in drinking water. Heavy metals that show significant changes and exceed the MCL are Mn, Zn, Pb and Fe. The conductivity value for the first sampling at various locations on December 2003 ranges from 60 - 12830 μS/cm and the these values were relatively increased on the second sampling in February 2004 which ranges from 155 - 13760 μS/cm. The sampling will be continued to obtain several series of complete data so that a conclusive evaluation of pollutant transport can be made. (Author)

  5. Potential pollutant sources in a Choptank River (USA) subwatershed and the influence of land use and watershed characteristics

    Science.gov (United States)

    Nino de Guzman, Gabriela T.; Hapeman, Cathleen J.; Prabhakara, Kusuma; Codling, Eton E.; Shelton, Daniel R.; Rice, Clifford P.; Hively, W. Dean; McCarty, Gregory W.; Lang, Megan W.; Torrents, Alba

    2012-01-01

    Row-crop and poultry production have been implicated as sources of water pollution along the Choptank River, an estuary and tributary of the Chesapeake Bay. This study examined the effects of land use, subwatershed characteristics, and climatic conditions on the water quality parameters of a subwatershed in the Choptank River watershed. The catchments within the subwatershed were defined using advanced remotely-sensed data and current geographic information system processing techniques. Water and sediment samples were collected in May–October 2009 and April–June 2010 under mostly baseflow conditions and analyzed for select bacteria, nitrate-N, ammonium-N, total arsenic, total phosphorus (TP), orthophosphate (ortho-P), and particle-phase phosphorus (PP); n = 96 for all analytes except for arsenic, n = 136, and for bacteria, n = 89 (aqueous) and 62 (sediment). Detections of Enterococci and Escherichia coli concentrations were ubiquitous in this subwatershed and showed no correlation to location or land use, however larger bacterial counts were observed shortly after precipitation. Nitrate-N concentrations were not correlated with agricultural lands, which may reflect the small change in percent agriculture and/or the similarity of agronomic practices and crops produced between catchments. Concentration data suggested that ammonia emission and possible deposition to surface waters occurred and that these processes may be influenced by local agronomic practices and climatic conditions. The negative correlation of PP and arsenic concentrations with percent forest was explained by the stronger signal of the head waters and overland flow of particulate phase analytes versus dissolved phase inputs from groundwater. Service roadways at some poultry production facilities were found to redirect runoff from the facilities to neighboring catchment areas, which affected water quality parameters. Results suggest that in this subwatershed, catchments with poultry production

  6. Wild Ungulate Distribution in the Naban River Watershed National Nature Reserve, Southwest China

    Directory of Open Access Journals (Sweden)

    A.C. Treydte

    2014-01-01

    Full Text Available Southeast Asia´s tropical forests harbour a unique diversity of wildlife but species and numbers are rapidly declining under current land use. To improve conservation strategies in these biodiversity hotspots, knowledge of animal species present and their distribution is crucial. We wanted to identify the ungulate community composition and distribution of a ‘Man and Biosphere’ reserve, the Naban River Watershed National Nature Reserve (NRWNNR, Yunnan, Southwest China. Using camera traps, transects, and spoor-plots we identified wild ungulate species and corresponding habitat properties. We compared two study sites of different protection status – the buffer and experimental zones – on an overall transect length of 32 km and analysed relationships between wildlife activity, forest vegetation structure, and human disturbance. We documented six ungulate species, all of which occurred in the buffer zone while only three species were found in the experimental zone. Wild boar sign density was about 10 times higher in the buffer than in the experimental zone. Overall wildlife sign density increased with distance away from human settlements and closer to the core zone. Hence, human disturbance strongly influenced wild ungulate abundance but the NRWNNR was found to host a diverse ungulate community, considering its small size and compared to other conservation areas in the region. The combination of various methods proved to be successful in identifying and locating forest wildlife. The NRWNNR, particularly the more strongly protected zones, could greatly contribute to future ecotourism activities in Yunnan if a strict preservation of buffer and core zones can be maintained.

  7. Simulation of Nitrogen and Phosphorus Load Runoff by a GIS-based Distributed Model for Chikugo River Watershed

    Science.gov (United States)

    Iseri, Haruka; Hiramatsu, Kazuaki; Harada, Masayoshi

    A distributed model was developed in order to simulate the process of nitrogen and phosphorus load runoff in the semi-urban watershed of the Chikugo River, Japan. A grid of cells 1km in size was laid over the study area, and several input variables for each cell area including DEM, land use and statistical data were extracted by GIS. In the process of water runoff, hydrograph calculated at Chikugo Barrage was in close agreement with the observed one, which achieved Nash-Sutcliffe coefficient of 0.90. In addition, the model simulated reasonably well the movement of TN and TP at each station. The model was also used to analyze three scenarios based on the watershed management: (1) reduction of nutrient loads from livestock farm, (2) improvement of septic tanks' wastewater treatment system and (3) application of purification function of paddy fields. As a result, effectiveness of management strategy in each scenario depended on land use patterns. The reduction rates of nutrient load effluent in scenarios (1) and (3) were higher than that in scenario (2). The present result suggests that an appropriate management of livestock farm together with the effective use of paddy environment would have significant effects on the reduction of nutrient loads. A suitable management strategy should be planned based on the land use pattern in the watershed.

  8. Analysis of streamflow distribution of non-point source nitrogen export from long-term urban-rural catchments to guide watershed management in the Chesapeake Bay watershed

    Science.gov (United States)

    Duncan, J. M.; Band, L. E.; Groffman, P.

    2017-12-01

    Discharge, land use, and watershed management practices (stream restoration and stormwater control measures) have been found to be important determinants of nitrogen (N) export to receiving waters. We used long-term water quality stations from the Baltimore Ecosystem Study Long-Term Ecological Research (BES LTER) Site to quantify nitrogen export across streamflow conditions at the small watershed scale. We calculated nitrate and total nitrogen fluxes using methodology that allows for changes over time; weighted regressions on time, discharge, and seasonality. Here we tested the hypotheses that a) while the largest N stream fluxes occur during storm events, there is not a clear relationship between N flux and discharge and b) N export patterns are aseasonal in developed watersheds where sources are larger and retention capacity is lower. The goal is to scale understanding from small watersheds to larger ones. Developing a better understanding of hydrologic controls on nitrogen export is essential for successful adaptive watershed management at societally meaningful spatial scales.

  9. Development and application of the Qausi Distributed Water Balance model (QDWB in the Neishaboor-Rokh watershed

    Directory of Open Access Journals (Sweden)

    sajjad razavi

    2017-03-01

    Full Text Available Limitation of water resources in Iran motivates sustaining and preserving of the resources in order to supply future water needs. Fulfilling these objectives will not be possible unless having accurate water balance of watersheds. The purpose of this study is to estimate the water balance parameters using a distributed method. The large number of distributed models and methods was studied and “Quasi Distributed Water Balance model” (QDWB was written in the MATLAB programming environment. To conduct this model, it is needed that each data layer (precipitation, potential evapotranspiration, land use, soil data,.. to be converted into grid format. In this research the 500m * 500m cell size was used and water balance parameters for each cell was estimated. Runoff and deep percolation obtained from surface balance equation and irrigation needs were estimated based on soil moisture deficit. The study area of 9157 square kilometers is Neyshabour- Rokh watershed. The results showed there is a good correlation between water balance parameters such as precipitation-runoff, precipitation-evapotranspiration, and precipitation- deep percoulation and demonstrate that QDWB model is consistent with the basin hydrological process.Change in soil moisture at basin wide is 1 MCM in 1388-89 and 40 MCM in 1380-81. The evapotranspiration results from a distributed model” SWAT” and QDWB model were in good agreement.

  10. Distribution and source analysis of heavy metal pollutants in sediments of a rapid developing urban river system.

    Science.gov (United States)

    Xia, Fang; Qu, Liyin; Wang, Ting; Luo, Lili; Chen, Han; Dahlgren, Randy A; Zhang, Minghua; Mei, Kun; Huang, Hong

    2018-09-01

    Heavy metal pollution of aquatic environments in rapidly developing industrial regions is of considerable global concern due to its potential to cause serious harm to aquatic ecosystems and human health. This study assessed heavy metal contamination of sediments in a highly industrialized urban watershed of eastern China containing several historically unregulated manufacturing enterprises. Total concentrations and solid-phase fractionation of Cu, Zn, Pb, Cr and Cd were investigated for 39 river sediments using multivariate statistical analysis and geographically weighted regression (GWR) methods to quantitatively examine the relationship between land use and heavy metal pollution at the watershed scale. Results showed distinct spatial patterns of heavy metal contamination within the watershed, such as higher concentrations of Zn, Pb and Cd in the southwest and higher Cu concentration in the east, indicating links to specific pollution sources within the watershed. Correlation and PCA analyses revealed that Zn, Pb and Cd were dominantly contributed by anthropogenic activities; Cu originated from both industrial and agricultural sources; and Cr has been altered by recent pollution control strategies. The GWR model indicated that several heavy metal fractions were strongly correlated with industrial land proportion and this correlation varied with the level of industrialization as demonstrated by variations in local GWR R 2 values. This study provides important information for assessing heavy metal contaminated areas, identifying heavy metal pollutant sources, and developing regional-scale remediation strategies. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Multiple Scales of Control on the Structure and Spatial Distribution of Woody Vegetation in African Savanna Watersheds.

    Directory of Open Access Journals (Sweden)

    Nicholas R Vaughn

    Full Text Available Factors controlling savanna woody vegetation structure vary at multiple spatial and temporal scales, and as a consequence, unraveling their combined effects has proven to be a classic challenge in savanna ecology. We used airborne LiDAR (light detection and ranging to map three-dimensional woody vegetation structure throughout four savanna watersheds, each contrasting in geologic substrate and climate, in Kruger National Park, South Africa. By comparison of the four watersheds, we found that geologic substrate had a stronger effect than climate in determining watershed-scale differences in vegetation structural properties, including cover, height and crown density. Generalized Linear Models were used to assess the spatial distribution of woody vegetation structural properties, including cover, height and crown density, in relation to mapped hydrologic, topographic and fire history traits. For each substrate and climate combination, models incorporating topography, hydrology and fire history explained up to 30% of the remaining variation in woody canopy structure, but inclusion of a spatial autocovariate term further improved model performance. Both crown density and the cover of shorter woody canopies were determined more by unknown factors likely to be changing on smaller spatial scales, such as soil texture, herbivore abundance or fire behavior, than by our mapped regional-scale changes in topography and hydrology. We also detected patterns in spatial covariance at distances up to 50-450 m, depending on watershed and structural metric. Our results suggest that large-scale environmental factors play a smaller role than is often attributed to them in determining woody vegetation structure in southern African savannas. This highlights the need for more spatially-explicit, wide-area analyses using high resolution remote sensing techniques.

  12. Extending flood forecasting lead time in a large watershed by coupling WRF QPF with a distributed hydrological model

    Science.gov (United States)

    Li, Ji; Chen, Yangbo; Wang, Huanyu; Qin, Jianming; Li, Jie; Chiao, Sen

    2017-03-01

    Long lead time flood forecasting is very important for large watershed flood mitigation as it provides more time for flood warning and emergency responses. The latest numerical weather forecast model could provide 1-15-day quantitative precipitation forecasting products in grid format, and by coupling this product with a distributed hydrological model could produce long lead time watershed flood forecasting products. This paper studied the feasibility of coupling the Liuxihe model with the Weather Research and Forecasting quantitative precipitation forecast (WRF QPF) for large watershed flood forecasting in southern China. The QPF of WRF products has three lead times, including 24, 48 and 72 h, with the grid resolution being 20 km  × 20 km. The Liuxihe model is set up with freely downloaded terrain property; the model parameters were previously optimized with rain gauge observed precipitation, and re-optimized with the WRF QPF. Results show that the WRF QPF has bias with the rain gauge precipitation, and a post-processing method is proposed to post-process the WRF QPF products, which improves the flood forecasting capability. With model parameter re-optimization, the model's performance improves also. This suggests that the model parameters be optimized with QPF, not the rain gauge precipitation. With the increasing of lead time, the accuracy of the WRF QPF decreases, as does the flood forecasting capability. Flood forecasting products produced by coupling the Liuxihe model with the WRF QPF provide a good reference for large watershed flood warning due to its long lead time and rational results.

  13. Effect and relevance of the artificial drainage system when assessing the hydrologic impact of the imperviousness distribution within the watershed

    Science.gov (United States)

    Thenoux, M.; Gironas, J. A.; Mejia, A.

    2013-12-01

    Cities and urban growth have relevant environmental and social impacts, which could eventually be enhanced or reduced during the urban planning process. From the point of view of hydrology, impermeability and natural soil compaction are one of the main problems that urbanization brings to watershed. Previous studies demonstrate and quantify the impacts of the distribution of imperviousness in a watershed, both on runoff volumes and flow, and the quality and integrity of streams and receiving bodies. Moreover, some studies have investigated the optimal distribution of imperviousness, based on simulating different scenarios of land use change and its effects on runoff, mostly at the outlet of the watershed. However, these studies typically do not address the impact of artificial drainage system associated with the imperviousness scenarios, despite it is known that storm sewer coverage affects the flow accumulation and generation of flow hydrographs. This study seeks to quantify the effects and relevance of the artificial system when it comes to assess the hydrological impacts of the spatial distribution of imperviousness and to determine the characteristics of this influence. For this purpose, an existing model to generate imperviousness distribution scenarios is coupled with a model developed to automatically generate artificial drainage networks. These models are applied to a natural watershed to generate a variety of imperviousness and storm sewer layout scenarios, which are evaluate with a morphoclimatic instantaneous unit hydrograph model. We first tested the ability of this approach to represent the joint effects of imperviousness (i.e. level and distribution) and storm sewer coverage. We then quantified the effects of these variables on the hydrological response, considering also different return period in order to take into account the variability of the precipitation regime. Overall, we show that the layout and spatial coverage of the storm sewer system

  14. [Distribution of heavy metals in waters and pollution assessment in thallium contaminated area of Yunfu, Guangdong].

    Science.gov (United States)

    Li, Xiang-ping; Qi, Jian-ying; Wang, Chun-lin; Chen, Yong-heng

    2011-05-01

    Distribution of Thallium(T1), Cadmium( Cd), Chromium (Cr), Lead (Pb), Nickel (Ni), Arsenic (As), Copper (Cu), Zinc (Zn) in water and sediments of Yunfu pyrite mine area was studied. The environmental risk assessment was conducted systematically using Sediment Quality Guidelines (SQGs) and Hakanson potential ecological risk index. The results indicated that concentration range of Tl in stream water was 0.19-65.25 microg/L, which is higher than the environmental quality standards for surface water. Concentration ranges of Tl, Zn, As, Cd, Pb in sediments were 5.89-63.0 mg/kg, 1215-5754 mg/kg, 208.4-1327 mg/kg, 4.20-17.5 mg/kg, 282-13,770 mg/kg. According to Sediments Quality Guidelines, sediments was moderately to severe level of pollution since concentrations of Tl, Cd, Cr, Pb, Ni, As, Cu, Zn were much higher than LEL (lowest effect level) values, and the concentrations of Pb, As, Zn were higher than SEL (severe effect level) values, the others were partly higher than SEL values, which may result in severe negative biota effects in the watersheds. Compared to soil background values of Guangdong province, the metals in stream sediment showed strong to severe strong ecological risk, and the ecological risk of heavy metals in the descending order of Tl, Cd, As, Pb, Cr, Ni, Zn and Cu. Besides, the sediments were severe contained by toxic element thallium and cadmium. Besides, the mainly ecological risk of heavy metal is thallium. More emphasis should be placed on thallium and cadmium control and disposal in

  15. SOIL ALUMINUM DISTRIBUTION IN THE NEAR-STREAM ZONE AT THE BEAR BROOK WATERSHED IN MAINE

    Science.gov (United States)

    Near-stream and upslope soil chemical properties were analyzed to infer linkages between soil and surface water chemistry at the Bear Brook Watershed in Maine [BBWM]. Organic and mineral soil samples were collected along six 20 m transects perpendicular to the stream and one 200 ...

  16. Capturing microbial sources distributed in a mixed-use watershed within an integrated environmental modeling workflow

    Science.gov (United States)

    Many watershed models simulate overland and instream microbial fate and transport, but few provide loading rates on land surfaces and point sources to the waterbody network. This paper describes the underlying equations for microbial loading rates associated with 1) land-applied ...

  17. Distribution and sources of polyfluoroalkyl substances (PFAS) in the River Rhine watershed

    NARCIS (Netherlands)

    Möller, A.; Ahrens, L.; Surm, R.; Westerveld, J.; van der Wielen, F.; Ebinghaus, R.; de Voogt, P.

    2010-01-01

    The concentration profile of 40 polyfluoroalkyl substances (PFAS) in surface water along the River Rhine watershed from the Lake Constance to the North Sea was investigated. The aim of the study was to investigate the influence of point as well as diffuse sources, to estimate fluxes of PFAS into the

  18. Distribution of pollutants in the Russian sector of the Black Sea coastal zone

    International Nuclear Information System (INIS)

    Kos'yan, R.D.; Yesin, N.V.

    1999-01-01

    For the latest 30-40 years the Black Sea pollution by various pollutants is observed. It is the result of economical activity intensification on the shore and of slow growth of cleaning system capacity. In the coastal zone concentration of pollutants depends on the pollutant amount brought from the source and the process of their distribution and transport to the open sea. Within the Krasnodar region towns of Novorossiisk, Gelendzhik, Tuapse, Sochi and the ports of Novorossiisk and Tuapse are the main sources of pollutants

  19. Observations of distributed snow depth and snow duration within diverse forest structures in a maritime mountain watershed

    Science.gov (United States)

    Dickerson-Lange, Susan E.; Lutz, James A.; Gersonde, Rolf; Martin, Kael A.; Forsyth, Jenna E.; Lundquist, Jessica D.

    2015-11-01

    Spatially distributed snow depth and snow duration data were collected over two to four snow seasons during water years 2011-2014 in experimental forest plots within the Cedar River Municipal Watershed, 50 km east of Seattle, Washington, USA. These 40 × 40 m forest plots, situated on the western slope of the Cascade Range, include unthinned second-growth coniferous forests, variable density thinned forests, forest gaps in which a 20 m diameter (approximately equivalent to one tree height) gap was cut in the middle of each plot, and old-growth forest. Together, this publicly available data set includes snow depth and density observations from manual snow surveys, distributed snow duration observations from ground temperature sensors and time-lapse cameras, meteorological data collected at two open locations and three forested locations, and forest canopy data from airborne light detection and ranging (LiDAR) data and hemispherical photographs. These colocated snow, meteorological, and forest data have the potential to improve understanding of forest influences on snow processes, and provide a unique model-testing data set for hydrological analyses in a forested, maritime watershed. We present empirical snow depletion curves within forests to illustrate an application of these data to improve subgrid representation of snow cover in distributed modeling.

  20. Developing of Watershed Radionuclide Transport Model DHSVM-R as Modification and Extension of Distributed Hydrological and Sediment Dynamics Model DHSVM

    Science.gov (United States)

    Zheleznyak, M.; Kivva, S.; Onda, Y.; Nanba, K.; Wakiyama, Y.; Konoplev, A.

    2015-12-01

    The reliable modeling tools for prediction wash - off radionuclides from watersheds are needed as for assessment the consequences of accidental and industrial releases of radionuclides, as for soil erosion studies using the radioactive tracers. The distributed model of radionuclide transport through watershed in exchangeable and nonexchangeable forms in solute and with sediments was developed and validated for small Chernobyl watersheds in 90th within EU SPARTACUS project (van der Perk et al., 1996). New tendency is coupling of radionuclide transport models and the widely validated hydrological distributed models. To develop radionuclide transport model DHSVM-R the open source Distributed Hydrology Soil Vegetation Model -DHSVM http://www.hydro.washington.edu/Lettenmaier/Models/DHSVM was modified and extended. The main changes provided in the hydrological and sediment transport modules of DHSVM are as follows: Morel-Seytoux infiltration model is added; four-directions schematization for the model's cells flows (D4) is replaced by D8 approach; the finite-difference schemes for solution of kinematic wave equations for overland water flow, stream net flow, and sediment transport are replaced by new computationally efficient scheme. New radionuclide transport module, coupled with hydrological and sediment transport modules, continues SPARTACUS's approach, - it describes radionuclide wash-off from watershed and transport via stream network in soluble phase and on suspended sediments. The hydrological module of DHSVM-R was calibrated and validated for the watersheds of Ukrainian Carpathian mountains and for the subwatersheds of Niida river flowing 137Cs in solute and with suspended sediments to Pacific Ocean at 30 km north of the Fukushima Daiichi NPP. The modules of radionuclide and sediment transport were calibrated and validated versus experimental data for USLE experimental plots in Fukushima Prefecture and versus monitoring data collected in Niida watershed. The role

  1. Advanced airflow distribution methods for reduction of personal exposure to indoor pollutants

    DEFF Research Database (Denmark)

    Cao, Guangyu; Kosonen, Risto; Melikov, Arsen

    2016-01-01

    The main objective of this study is to recognize possible airflow distribution methods to protect the occupants from exposure to various indoor pollutants. The fact of the increasing exposure of occupants to various indoor pollutants shows that there is an urgent need to develop advanced airflow ...... distribution methods to reduce indoor exposure to various indoor pollutants. This article presents some of the latest development of advanced airflow distribution methods to reduce indoor exposure in various types of buildings.......The main objective of this study is to recognize possible airflow distribution methods to protect the occupants from exposure to various indoor pollutants. The fact of the increasing exposure of occupants to various indoor pollutants shows that there is an urgent need to develop advanced airflow...

  2. Long-term survey of heavy-metal pollution, biofilm contamination and diatom community structure in the Riou Mort watershed, South-West France

    International Nuclear Information System (INIS)

    Morin, S.; Duong, T.T.; Dabrin, A.; Coynel, A.; Herlory, O.; Baudrimont, M.; Delmas, F.; Durrieu, G.; Schaefer, J.; Winterton, P.; Blanc, G.; Coste, M.

    2008-01-01

    In a metal-polluted stream in the Riou Mort watershed in SW France, periphytic biofilm was analyzed for diatom cell densities and taxonomic composition, dry weight and metal bio-accumulation (cadmium and zinc). Periphytic diatom communities were affected by the metal but displayed induced tolerance, seen through structural impact (dominance of small, adnate species) as well as morphological abnormalities particularly in the genera Ulnaria and Fragilaria. Species assemblages were characterized by taxa known to occur in metal-polluted environments, and shifts in the community structure expressed seasonal patterns: high numbers of Eolimna minima, Nitzschia palea and Pinnularia parvulissima were recorded in Summer and Autumn, whereas the species Surirella brebissonii, Achnanthidium minutissimum, Navicula lanceolata and Surirella angusta were dominant in Winter and Spring. Commonly used indices such as the Shannon diversity index and Specific Pollution Sensitivity Index reflected the level of pollution and suggest seasonal periodicity, the lowest diversities being observed in Summer. - Periphytic biofilm diatom communities are suitable indicators for the bioassay of elevated levels of metals in contaminated river water

  3. Distribution of Heavy Metal Pollution in Surface Soil Samples in China: A Graphical Review.

    Science.gov (United States)

    Duan, Qiannan; Lee, Jianchao; Liu, Yansong; Chen, Han; Hu, Huanyu

    2016-09-01

    Soil pollution in China is one of most wide and severe in the world. Although environmental researchers are well aware of the acuteness of soil pollution in China, a precise and comprehensive mapping system of soil pollution has never been released. By compiling, integrating and processing nearly a decade of soil pollution data, we have created cornerstone maps that illustrate the distribution and concentration of cadmium, lead, zinc, arsenic, copper and chromium in surficial soil across the nation. These summarized maps and the integrated data provide precise geographic coordinates and heavy metal concentrations; they are also the first ones to provide such thorough and comprehensive details about heavy metal soil pollution in China. In this study, we focus on some of the most polluted areas to illustrate the severity of this pressing environmental problem and demonstrate that most developed and populous areas have been subjected to heavy metal pollution.

  4. Lake and watershed influences on the distribution of elemental contaminants in the Rideau Canal System, a UNESCO world heritage site.

    Science.gov (United States)

    Stuyt, Shannon S M; Chapman, E Emily V; Campbell, Linda M

    2015-08-01

    Watershed-specific variables such as sediment particle size distribution, water depth, sedimentation rate, focusing factors, and catchment area to lake area ratio can affect the distribution of trace element contaminants to lakes. The aim of this study was to investigate sources of metals to three headwater lakes and to quantify effects of watershed-specific variables on spatial and temporal trends of trace elements (As, Cd, Co, Cr, Cu, Hg, K, Ni, Pb, Rb, and Zn) in sediments and mercury (Hg) concentrations in fish. Surface sediment and water samples were used to characterize spatial patterns, while sediment cores were collected to portray temporal trends. Historical trends of Hg in northern pike (Esox lucius) were assessed in relation to paleolimnological trends of sediment Hg concentrations. Similarity in timing of sediment peak trace element concentrations for the lakes suggests large-scale, atmospheric sources. The lake with highest catchment area-to-lake area ratio was consistently associated with highest sediment elemental concentrations and displayed significant correlations between increased sediment Hg concentrations and decreased pike tissue concentrations over time. This suggests that catchment area-to-lake area ratio is an important factor influencing the concentration of atmospherically derived contaminants within lake sediments and their transfer through the food web.

  5. Distribution of Escherichia Coli as Soil Pollutant around Antang Landfills

    Science.gov (United States)

    Artiningsih, Andi; Zubair, Hazairin; Imran, A. M.; Widodo, Sri

    2018-03-01

    Tamangapa Antang Landfill locates around the residential area and faces an air and water pollution due to an open dumping system in its operation. The system arises a potential pollution in air, water and soil. Sampling was done surround the landfill in two parts, parallel and perpendicular to the ground water flow. This study shows the abundance of E. coli bacteria in soil around the Antang Landfills at depth of 10 to 20 cm (93x105 cfu/gr of soil) in the direction of groundwater flow. While in other locations the E. coli bacteria is not detected. The abundance of E. coli bacteria is a conjunction factor from landfill and human activities surround the area. The absence of E. coli bacteria in other location highly interpreted that the landfill is the major contributor of pollutant.

  6. 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

  7. An application of the distributed hydrologic model CASC2D to a tropical montane watershed

    Science.gov (United States)

    Marsik, Matt; Waylen, Peter

    2006-11-01

    SummaryIncreased stormflow in the Quebrada Estero watershed (2.5 km 2), in the northwestern Central Valley tectonic depression of Costa Rica, reportedly has caused flooding of the city of San Ramón in recent decades. Although scientifically untested, urban expansion was deemed the cause and remedial measures were recommended by the Programa de Investigación en Desarrollo Humano Sostenible (ProDUS). CASC2D, a physically-based, spatially explicit hydrologic model, was constructed and calibrated to a June 10th 2002 storm that delivered 110.5 mm of precipitation in 4.5 h visibly exceeded the bankfull stage (0.9 m) of the Quebrada flooding portions of San Ramón. The calibrated hydrograph showed a peak discharge 16.68% (2.5 m 3 s -1) higher, an above flood stage duration 20% shorter, and time to peak discharge 11 min later than the same observed discharge hydrograph characteristics. Simulations of changing land cover conditions from 1979 to 1999 showed an increase also in the peak discharge, above flood stage duration, and time to peak discharge. Analysis using a modified location quotient identified increased urbanization in lower portions of the watershed over the time period studied. These results suggest that increased urbanization in the Quebrada Estero watershed have increased flooding peaks, and durations above threshold, confirming the ProDUS report. These results and the CASC2D model offer an easy-to-use, pragmatic planning tool for policymakers in San Ramón to assess future development scenarios and their potential flooding impacts to San Ramón.

  8. Hydrogeological constraints on riparian buffers for reduction of diffuse pollution: examples from the Bear Creek watershed in Iowa, USA.

    Science.gov (United States)

    Simpkins, W W; Wineland, T R; Andress, R J; Johnston, D A; Caron, G C; Isenhart, T M; Schultz, R C

    2002-01-01

    Riparian Management Systems (RiMS) have been proposed to minimize the impacts of agricultural production and improve water quality in Iowa in the Midwestern USA. As part of RiMS, multispecies riparian buffers have been shown to decrease nutrient, pesticide, and sediment concentrations in runoff from adjacent crop fields. However, their effect on nutrients and pesticides moving in groundwater beneath buffers has been discussed only in limited and idealized hydrogeologic settings. Studies in the Bear Creek watershed of central Iowa show the variability inherent in hydrogeologic systems at the watershed scale, some of which may be favorable or unfavorable to future implementation of buffers. Buffers may be optimized by choosing hydrogeologic systems where a shallow groundwater flow system channels water directly through the riparian buffer at velocities that allow for processes such as denitrification to occur.

  9. Chironomid distribution along a pollution gradient in Ethiopian rivers ...

    African Journals Online (AJOL)

    Water pollution resulting from the rapidly intensifying use of freshwater resources in Ethiopia is increasing the need for continuous follow-up and monitoring of the country's aquatic ecosystems, in order to maintain their biological diversity and water quality. Chironomids (non-biting dipteran midges) are often used for ...

  10. Distribution and sources of polyfluoroalkyl substances (PFAS) in the River Rhine watershed

    International Nuclear Information System (INIS)

    Moeller, Axel; Ahrens, Lutz; Surm, Renate; Westerveld, Joke; Wielen, Frans van der; Ebinghaus, Ralf; Voogt, Pim de

    2010-01-01

    The concentration profile of 40 polyfluoroalkyl substances (PFAS) in surface water along the River Rhine watershed from the Lake Constance to the North Sea was investigated. The aim of the study was to investigate the influence of point as well as diffuse sources, to estimate fluxes of PFAS into the North Sea and to identify replacement compounds of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In addition, an interlaboratory comparison of the method performance was conducted. The PFAS pattern was dominated by perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) with concentrations up to 181 ng/L and 335 ng/L, respectively, which originated from industrial point sources. Fluxes of ΣPFAS were estimated to be ∼6 tonnes/year which is much higher than previous estimations. Both, the River Rhine and the River Scheldt, seem to act as important sources of PFAS into the North Sea. - The short-chained polyfluoroalkyl substances PFBA and PFBS replace PFOA and PFOA as dominating PFAS in surface waters in the River Rhine watershed.

  11. Distribution and seasonal differences in Pacific Lamprey and Lampetra spp eDNA across 18 Puget Sound watersheds

    Science.gov (United States)

    Ostberg, Carl O.; Chase, Dorothy M.; Hayes, Michael C.; Duda, Jeffrey J.

    2018-01-01

    Lampreys have a worldwide distribution, are functionally important to ecological communities and serve significant roles in many cultures. In Pacific coast drainages of North America, lamprey populations have suffered large declines. However, lamprey population status and trends within many areas of this region are unknown and such information is needed for advancing conservation goals. We developed two quantitative PCR-based, aquatic environmental DNA (eDNA) assays for detection of Pacific Lamprey (Entosphenus tridentatus) and Lampetra spp, using locked nucleic acids (LNAs) in the probe design. We used these assays to characterize the spatial distribution of lamprey in 18 watersheds of Puget Sound, Washington, by collecting water samples in spring and fall. Pacific Lamprey and Lampetraspp were each detected in 14 watersheds and co-occurred in 10 watersheds. Lamprey eDNA detection rates were much higher in spring compared to fall. Specifically, the Pacific Lamprey eDNA detection rate was 3.5 times higher in spring and the Lampetra spp eDNA detection rate was 1.5 times higher in spring even though larval lamprey are present in streams year-round. This significant finding highlights the importance of seasonality on eDNA detection. Higher stream discharge in the fall likely contributed to reduced eDNA detection rates, although seasonal life history events may have also contributed. These eDNA assays differentiate Pacific Lamprey and Lampetra spp across much of their range along the west coast of North America. Sequence analysis indicates the Pacific Lamprey assay also targets other Entosphenus spp and indicates the Lampetra spp assay may have limited or no capability of detecting Lampetra in some locations south of the Columbia River Basin. Nevertheless, these assays will serve as a valuable tool for resource managers and have direct application to lamprey conservation efforts, such as mapping species distributions, occupancy modeling, and monitoring

  12. Emerging pollutants in the Esmeraldas watershed in Ecuador: discharge and attenuation of emerging organic pollutants along the San Pedro– Guayllabamba–Esmeraldas rivers

    OpenAIRE

    Voloshenko-Rossin, A.; Gasser, G.; Cohen, K.; Gun, J.; Cumbal-Flores, L.; Parra- Morales, W.; Sarabia, F.; Ojeda, F.; Lev, O.

    2015-01-01

    Water quality characteristics and emerging organic pollutants were sampled along the San Pedro–Guayllabamba–Esmeraldas River and its main water pollution streams in the summer of 2013. The annual flow rate of the stream is 22 000 Mm3 y 1 and it collects the wastewater of Quito-Ecuador in the Andes and supplies drinking water to the city of Esmeraldas near the Pacific Ocean. The most persistent emerging pollutants were carbamazepine and acesulfame, which were found to be stable along the San ...

  13. Distribution, Transport, and Accumulation of Pyrogenic Black Carbon in Post-Wildfire Watersheds

    Science.gov (United States)

    Galanter, A.; Cadol, D. D.; Frey, B.; Lohse, K. A.

    2014-12-01

    Large, high severity wildfires greatly alter forest structure, water quality, and soil development/erosion. With increased frequency of such wildfires also follows heavy post-wildfire debris flows and flooding which deliver high loads of sediment and pyrogenic black carbon (PyC) to downstream waterways. The accumulation of PyC is a multi-faceted and dynamic issue in the critical zone. Generated by incomplete combustion of organic matter, PyC (in the form of soot and char) impacts turbidity, biological and chemical oxygen demand, and pH. In addition, PyC has the potential to sequester contaminants and can store carbon over short and long timescales. The impacts of two recent wildfires in Northern New Mexico are studied with the goal of understanding the fluxes and residence times of PyC in post-wildfire, mountainous watersheds. Employing burn severity maps and geospatial data, we selected three sites to collect soil and water samples to characterize PyC: a control, an area impacted by a large, severe burn (2011), and an area impacted by a smaller, less severe burn (2013). By collaborating with researchers at the Jemez Critical Zone Observatory, soil samples are being analyzed and will provide pre-wildfire PyC concentrations for the 2013 burn area. In this study, PyC is treated as both a particulate and a solute that is transported throughout the watershed as well as degraded in soils, surface water and groundwater. We used two black carbon quantification methods: the chemo-thermal oxidation (CTO-375) method to distinguish between soil soot and char, and the benzene polycarboxylic acids (BPCA) method to quantify the total concentrations of PyC in soil and water samples. Preliminary soil data from the CTO-375 method show comparable soot concentrations in the control, 2011, and 2013 burn indicating that the soot is more recalcitrant than char and remains in the watershed long after a wildfire. This data also suggests that the fluxes of black carbon over short time

  14. Distribution and sources of polyfluoroalkyl substances (PFAS) in the River Rhine watershed.

    Science.gov (United States)

    Möller, Axel; Ahrens, Lutz; Surm, Renate; Westerveld, Joke; van der Wielen, Frans; Ebinghaus, Ralf; de Voogt, Pim

    2010-10-01

    The concentration profile of 40 polyfluoroalkyl substances (PFAS) in surface water along the River Rhine watershed from the Lake Constance to the North Sea was investigated. The aim of the study was to investigate the influence of point as well as diffuse sources, to estimate fluxes of PFAS into the North Sea and to identify replacement compounds of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In addition, an interlaboratory comparison of the method performance was conducted. The PFAS pattern was dominated by perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) with concentrations up to 181 ng/L and 335 ng/L, respectively, which originated from industrial point sources. Fluxes of SigmaPFAS were estimated to be approximately 6 tonnes/year which is much higher than previous estimations. Both, the River Rhine and the River Scheldt, seem to act as important sources of PFAS into the North Sea. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  15. Sources, distribution, and mobility of plutonium and radiocesium in soils, sediments and water of the Hudson River Estuary and watershed

    International Nuclear Information System (INIS)

    Linsalata, P.

    1984-01-01

    Results of 239 240 Pu, 238 Pu and 137 Cs measurements are reported for soil cores sampled within the watershed, for many sediment cores and surface dredge samples taken along the length of the Hudson River Estuary and for water samples collected on a continuous basis in both fresh and estuarine reaches. Accumulations of 239 240 Pu and 137 Cs measured within sediment cores taken from discrete regions of the river-estuary were summed to arrive at total sediment inventories of 1.6 +/- 0.7 Ci and 53 +/- 20 Ci, respectively. The variability observed in the sediment accumulation of radionuclides is discussed in terms of the physical and chemical characteristics of the river-estuary. Plutonium-239,240 and 137 Cs were similary distributed in sediments and water sampled from fresh water reaches of the Hudson with activity ratios (i.e., 239 240 Pu/ 1 2number 7 Cs) ranging from 0.01 to 0.03. Distribution coefficients, which were determined both in vitro and in situ were similar for both nuclides (i.e., from 1 x 10 5 to 3 x 10 5 L.kg -1 ) in fresh water, but diverged significantly (as a result of increased 137 Cs solubility) in brackish waters that exhibited chlorinities in excess of 1-2 g Cl - .L -1 . The concentrations of 239 240 Pu and 137 Cs observed in fresh water samples were primarily functions of the suspended load. Approximately 60-70% of the annual downstream transport of 239 240 Pu and 137 Cs calculated during 1980 and 1981 (i.e., 4 +/- 0.5 mCi and 515 +/- 84 mCi, respectively) was associated with suspended particulates greater than or equal to 0.45 μm. An empirical model was developed to determine the rates of vertical migration of these nuclides in soils of the watershed

  16. Technical Note: Method of Morris effectively reduces the computational demands of global sensitivity analysis for distributed watershed models

    Directory of Open Access Journals (Sweden)

    J. D. Herman

    2013-07-01

    Full Text Available The increase in spatially distributed hydrologic modeling warrants a corresponding increase in diagnostic methods capable of analyzing complex models with large numbers of parameters. Sobol' sensitivity analysis has proven to be a valuable tool for diagnostic analyses of hydrologic models. However, for many spatially distributed models, the Sobol' method requires a prohibitive number of model evaluations to reliably decompose output variance across the full set of parameters. We investigate the potential of the method of Morris, a screening-based sensitivity approach, to provide results sufficiently similar to those of the Sobol' method at a greatly reduced computational expense. The methods are benchmarked on the Hydrology Laboratory Research Distributed Hydrologic Model (HL-RDHM over a six-month period in the Blue River watershed, Oklahoma, USA. The Sobol' method required over six million model evaluations to ensure reliable sensitivity indices, corresponding to more than 30 000 computing hours and roughly 180 gigabytes of storage space. We find that the method of Morris is able to correctly screen the most and least sensitive parameters with 300 times fewer model evaluations, requiring only 100 computing hours and 1 gigabyte of storage space. The method of Morris proves to be a promising diagnostic approach for global sensitivity analysis of highly parameterized, spatially distributed hydrologic models.

  17. Sensitivity Test of Parameters Influencing Flood Hydrograph Routing with a Diffusion-Wave Distributed using Distributed Hydrological Model, Wet Spa, in Ziarat Watershed

    Directory of Open Access Journals (Sweden)

    narges javidan

    2017-02-01

    Full Text Available Introduction: Flood routing is a procedure to calculate flood stage and water depth along a river or to estimate flood hydrograph at river downstream or at reservoir outlets using the upstream hydrography . In river basins, excess rainfall is routed to the basin outlet using flow routing techniques to generate flow hydrograph. A GIS-based distributed hydrological model, Wet Spa, has been under development suitable for flood prediction and watershed management on a catchment scale. The model predicts outflow hydrographs at the basin outlet or at any converging point in the watershed, and it does so in a user-specified time step. The model is physically based, spatially distributed and time-continuous, and simulates hydrological processes of precipitation, snowmelt, interception, depression, surface runoff, infiltration, evapotranspiration, percolation, interflow, groundwater flow, etc. continuously both in time and space, for which the water and energy balance are maintained on each raster cell. Surface runoff is produced using a modified coefficient method based on the cellular characteristics of slope, land use, and soil type, and allowed to vary with soil moisture, rainfall intensity and storm duration. Interflow is computed based on the Darcy’s law and the kinematic approximation as a function of the effective hydraulic conductivity and the hydraulic gradient, while groundwater flow is estimated with a linear reservoir method on a small subcatchment scale as a function of groundwater storage and a recession coefficient. Special emphasis is given to the overland flow and channel flow routing using the method of linear diffusive wave approximation, which is capable to predict flow discharge at any converging point downstream by a unit response function. The model accounts for spatially distributed hydrological and geophysical characteristics of the catchment. Determination of the river flow hydrograph is a main target in hydrology

  18. Pollution

    NARCIS (Netherlands)

    Dürr, E.; Jaffe, R.; Nonini, D.M.

    2014-01-01

    This essay points to the role of pollution in understanding the social construction of hierarchies and urban space. Conceptualizations of pollution and approaches to waste management always reflect the Zeitgeist and tend to be politically charged. We argue that an ethnographic approach to pollution

  19. Watershed analysis

    Science.gov (United States)

    Alan Gallegos

    2002-01-01

    Watershed analyses and assessments for the Kings River Sustainable Forest Ecosystems Project were done on about 33,000 acres of the 45,500-acre Big Creek watershed and 32,000 acres of the 85,100-acre Dinkey Creek watershed. Following procedures developed for analysis of cumulative watershed effects (CWE) in the Pacific Northwest Region of the USDA Forest Service, the...

  20. Circulating persistent organic pollutants and body fat distribution

    DEFF Research Database (Denmark)

    Zong, Geng; Grandjean, Philippe; Wu, Hongyu

    2015-01-01

    and Nutrition Examination Survey 1999-2004. Partial Pearson correlation coefficients were calculated, after adjusting for major confounders, including age, smoking status, and history of lactation and parity. Wolfe's method was used to compare correlation coefficients derived from the same participants. RESULTS......OBJECTIVE: To evaluate and compare the correlations of various circulating persistent organic pollutants (POPs) with fat mass percentages (FM%) of trunk, leg, and whole body measured by dual-energy X-ray absorptiometry. METHODS: This study included 2358 adults (≥20 years) in the National Health......: Twelve POPs showed significantly different correlations with fat depots in trunk and leg regions. β-hexachlorocyclohexane, heptachlorodibenzo-p-dioxin, octachlorodibenzo-p-dioxin, and polychlorinated biphenyl (PCB)-126 showed stronger positive correlations with trunk FM% than with leg FM%, whereas PCBs...

  1. Advection-diffusion model for the simulation of air pollution distribution from a point source emission

    Science.gov (United States)

    Ulfah, S.; Awalludin, S. A.; Wahidin

    2018-01-01

    Advection-diffusion model is one of the mathematical models, which can be used to understand the distribution of air pollutant in the atmosphere. It uses the 2D advection-diffusion model with time-dependent to simulate air pollution distribution in order to find out whether the pollutants are more concentrated at ground level or near the source of emission under particular atmospheric conditions such as stable, unstable, and neutral conditions. Wind profile, eddy diffusivity, and temperature are considered in the model as parameters. The model is solved by using explicit finite difference method, which is then visualized by a computer program developed using Lazarus programming software. The results show that the atmospheric conditions alone influencing the level of concentration of pollutants is not conclusive as the parameters in the model have their own effect on each atmospheric condition.

  2. Modelling the bidirectional reflectance distribution functions (BRDF of sea areas polluted by oil

    Directory of Open Access Journals (Sweden)

    Zbigniew Otremba

    2004-12-01

    Full Text Available The paper discusses the possibilities of modelling the bi-directional reflectance distribution function (BRDF in sea areas polluted by oil. Three sea basin models are considered: a coastal one free of oil, one polluted by an oil film and one polluted by an oil emulsion. The following concentrations of oil were compared: for the film, 1 cm3 of oil per 1 m2 water surface, for the emulsion 1 cm3 of oil in 1 m3 of water. The optical properties of Romashkino crude oil were taken into consideration, as were various angles of incident solar light. The conversion of BRDFs into a directional distribution of the optical contrast of polluted areas is demonstrated.

  3. The pollutants from livestock and poultry farming in China-geographic distribution and drivers.

    Science.gov (United States)

    Gan, Ling; Hu, Xisheng

    2016-05-01

    Livestock and poultry farming is a major source of agricultural pollution. However, our knowledge of the constraining factors of the geographic distribution of pollutants from livestock and poultry farming is still limited. In this study, using the optimized pollutant generation coefficients, we estimated the annual pollutant productions of eight livestock and poultry species at the provincial level in 2005 and 2013 and their growth rates during the study period in China; using canonical correlation analysis, we also explored the association between the eight pollutant measurements as dependent variables and 14 factors (including resource endowment, developmental level, and economic structure factors) as independent variables. Results indicate that there exist spatial disparity in the distribution of pollutants from livestock and poultry farming across regions, with provinces in the Huang-Huai-Hai region and the southwestern region accounting for approximately 50 % of the total productions in the nation. Cattle, pig, and poultry constitute the primary pollution sources in terms of livestock and poultry farming not only at the national level but also at the province level. While the species constitute and their respective growth rates of the pollutants can be also characterized by spatial disparity across regions, canonical correlation analysis shows that the observed regional patterns of the pollutants can be largely explained by the resource endowment factors (positive effects) and the developmental level factors (negative effects). In addition, we found that the development of livestock and poultry farming is negatively associated with the growing rate of both the resource endowment and the socioeconomic factors. This indicates that there exist different driving patterns in the gross and increment of the pollutant productions. Our research has significant implications for the appropriate environmental protection policy formulation and implementation in livestock

  4. The distribution characteristics of pollutants released at different cross-sectional positions of a river

    International Nuclear Information System (INIS)

    Huang Heqing; Chen Guang; Zhang Qianfeng

    2010-01-01

    The distribution characteristics of heavier or lighter pollutants released at different cross-sectional positions of a wide river is investigated with a well-tested three-dimensional numerical model of gravity flows based on Reynolds-Averaged Navier-Stokes equations and turbulence k-ε model. By focusing on investigating the influences of flow and buoyancy on pollutants, it is found that while carrying by the river flow downstream: i) a heavier pollutant released from the cross-sectional side position, forms transverse oscillation between two banks with decreased amplitude, i.e. forms kind of helical flow pattern along the straight part of channel bed; ii) a heavier pollutant released from the cross-sectional middle position, forms collapse oscillation in the middle of the straight channel part with reduced amplitude; iii) in the downstream sinuous channel, heavier pollutant is of higher concentration on the outer side of channel bends; iv) a light pollutant released from the cross-sectional side position, slips partly to the other side of the river, resulting in higher concentrations on two sides of the channel top; v) a light pollutant released from the cross-sectional middle position, splits into two parts symmetrically along two sides of the channel top; vi) in the downstream sinuous channel, light pollutant presents higher concentration on the inner side of channel bends. These findings may assist in cost-effective scientific countermeasures to be taken for accidental or planned pollutant releases into a river. - The distribution characteristics of heavier or lighter pollutants released at different cross-sectional positions of a river.

  5. Distributed Water Pollution Source Localization with Mobile UV-Visible Spectrometer Probes in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Junjie Ma

    2018-02-01

    Full Text Available Pollution accidents that occur in surface waters, especially in drinking water source areas, greatly threaten the urban water supply system. During water pollution source localization, there are complicated pollutant spreading conditions and pollutant concentrations vary in a wide range. This paper provides a scalable total solution, investigating a distributed localization method in wireless sensor networks equipped with mobile ultraviolet-visible (UV-visible spectrometer probes. A wireless sensor network is defined for water quality monitoring, where unmanned surface vehicles and buoys serve as mobile and stationary nodes, respectively. Both types of nodes carry UV-visible spectrometer probes to acquire in-situ multiple water quality parameter measurements, in which a self-adaptive optical path mechanism is designed to flexibly adjust the measurement range. A novel distributed algorithm, called Dual-PSO, is proposed to search for the water pollution source, where one particle swarm optimization (PSO procedure computes the water quality multi-parameter measurements on each node, utilizing UV-visible absorption spectra, and another one finds the global solution of the pollution source position, regarding mobile nodes as particles. Besides, this algorithm uses entropy to dynamically recognize the most sensitive parameter during searching. Experimental results demonstrate that online multi-parameter monitoring of a drinking water source area with a wide dynamic range is achieved by this wireless sensor network and water pollution sources are localized efficiently with low-cost mobile node paths.

  6. Distributed Water Pollution Source Localization with Mobile UV-Visible Spectrometer Probes in Wireless Sensor Networks.

    Science.gov (United States)

    Ma, Junjie; Meng, Fansheng; Zhou, Yuexi; Wang, Yeyao; Shi, Ping

    2018-02-16

    Pollution accidents that occur in surface waters, especially in drinking water source areas, greatly threaten the urban water supply system. During water pollution source localization, there are complicated pollutant spreading conditions and pollutant concentrations vary in a wide range. This paper provides a scalable total solution, investigating a distributed localization method in wireless sensor networks equipped with mobile ultraviolet-visible (UV-visible) spectrometer probes. A wireless sensor network is defined for water quality monitoring, where unmanned surface vehicles and buoys serve as mobile and stationary nodes, respectively. Both types of nodes carry UV-visible spectrometer probes to acquire in-situ multiple water quality parameter measurements, in which a self-adaptive optical path mechanism is designed to flexibly adjust the measurement range. A novel distributed algorithm, called Dual-PSO, is proposed to search for the water pollution source, where one particle swarm optimization (PSO) procedure computes the water quality multi-parameter measurements on each node, utilizing UV-visible absorption spectra, and another one finds the global solution of the pollution source position, regarding mobile nodes as particles. Besides, this algorithm uses entropy to dynamically recognize the most sensitive parameter during searching. Experimental results demonstrate that online multi-parameter monitoring of a drinking water source area with a wide dynamic range is achieved by this wireless sensor network and water pollution sources are localized efficiently with low-cost mobile node paths.

  7. Predicting future changes in Muskegon River Watershed game fish distributions under future land cover alteration and climate change scenarios

    Science.gov (United States)

    Steen, Paul J.; Wiley, Michael J.; Schaeffer, Jeffrey S.

    2010-01-01

    Future alterations in land cover and climate are likely to cause substantial changes in the ranges of fish species. Predictive distribution models are an important tool for assessing the probability that these changes will cause increases or decreases in or the extirpation of species. Classification tree models that predict the probability of game fish presence were applied to the streams of the Muskegon River watershed, Michigan. The models were used to study three potential future scenarios: (1) land cover change only, (2) land cover change and a 3°C increase in air temperature by 2100, and (3) land cover change and a 5°C increase in air temperature by 2100. The analysis indicated that the expected change in air temperature and subsequent change in water temperatures would result in the decline of coldwater fish in the Muskegon watershed by the end of the 21st century while cool- and warmwater species would significantly increase their ranges. The greatest decline detected was a 90% reduction in the probability that brook trout Salvelinus fontinalis would occur in Bigelow Creek. The greatest increase was a 276% increase in the probability that northern pike Esox lucius would occur in the Middle Branch River. Changes in land cover are expected to cause large changes in a few fish species, such as walleye Sander vitreus and Chinook salmon Oncorhynchus tshawytscha, but not to drive major changes in species composition. Managers can alter stream environmental conditions to maximize the probability that species will reside in particular stream reaches through application of the classification tree models. Such models represent a good way to predict future changes, as they give quantitative estimates of the n-dimensional niches for particular species.

  8. On the feasibility of measuring urban air pollution by wireless distributed sensor networks.

    Science.gov (United States)

    Moltchanov, Sharon; Levy, Ilan; Etzion, Yael; Lerner, Uri; Broday, David M; Fishbain, Barak

    2015-01-01

    Accurate evaluation of air pollution on human-wellbeing requires high-resolution measurements. Standard air quality monitoring stations provide accurate pollution levels but due to their sparse distribution they cannot capture the highly resolved spatial variations within cities. Similarly, dedicated field campaigns can use tens of measurement devices and obtain highly dense spatial coverage but normally deployment has been limited to short periods of no more than few weeks. Nowadays, advances in communication and sensory technologies enable the deployment of dense grids of wireless distributed air monitoring nodes, yet their sensor ability to capture the spatiotemporal pollutant variability at the sub-neighborhood scale has never been thoroughly tested. This study reports ambient measurements of gaseous air pollutants by a network of six wireless multi-sensor miniature nodes that have been deployed in three urban sites, about 150 m apart. We demonstrate the network's capability to capture spatiotemporal concentration variations at an exceptional fine resolution but highlight the need for a frequent in-situ calibration to maintain the consistency of some sensors. Accordingly, a procedure for a field calibration is proposed and shown to improve the system's performance. Overall, our results support the compatibility of wireless distributed sensor networks for measuring urban air pollution at a sub-neighborhood spatial resolution, which suits the requirement for highly spatiotemporal resolved measurements at the breathing-height when assessing exposure to urban air pollution. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. The distribution of hillslope-channel interactions in a rangeland watershed

    Science.gov (United States)

    Leslie M. Reid

    1998-01-01

    The distribution of erosion and deposition in a basin--and thus of the major controls on basin evolution--is dependent upon the local balance between sediment transport and sediment supply. This balance, in turn, reflects the nature, strength, and distribution of interactions between hillslope and channel processes.

  10. Hydrogeochemistry of arsenic pollution in watersheds influenced by gold mining activities in Paracatu (Minas Gerais State, Brazil).

    Science.gov (United States)

    Bidone, Edison; Castilhos, Zuleica; Cesar, Ricardo; Santos, Maria Carla; Sierpe, Ricardo; Ferreira, Marcos

    2016-05-01

    The aim of this study is to evaluate total arsenic (As) concentrations in drinking water (main pathway of human exposure) and its hydrogeochemical controls in the "Morro do Ouro" gold mine region, which is the largest gold mine in Brazil, characterized by gold-arsenopyrite association. Arsenic concentration was generally below the detection limit (LOD 20°, being readily covered by thick phyllites that are poor in As some hundreds of meters away from the mine. Thirty-five percent of As levels in superficial waters (10 μg L(-1), which is the maximum permissible value for human ingestion. The highest concentrations were found nearby mine facilities and old artisanal mining areas surrounding the mine, decreasing downstream. Undisturbed watersheds showed As concentrations close to LOD. Hydrogeochemical data stress the sorption (adsorption and co-precipitation) of As role, mainly by Fe oxyhydroxides, as a geochemical filter that retains As, attenuating its concentration in both superficial and groundwater. Such minerals are abundant in the region oxisols, sediments, and phyllites and may form stable mineral complexes with As under the pH (mostly neutral) and Eh (reduced environment) conditions found in the field. It has been demonstrated that As(III) (more toxic) and As(V) co-exist in the analyzed waters and that As(V) predominates in superficial water.

  11. On the vertical distribution of pollutants in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Perez Vidal, H. [Universidad Juarez Autonoma de Tabasco, Division Academica de Ciencias Basicas, Tabasco (Mexico); Raga, G. B. [Centro de Ciencias de la Atmosfera, UNAM, Mexico, D.F. (Mexico)

    1998-04-01

    The problem of air pollution in Mexico City is studied through the analysis of a large dataset obtained by an instrumented aircraft during February 1991. These data constitute a unique set in Mexico and provide insight into the vertical structure of the boundary layer and the pollutant species which has not been previously discussed. The results obtained on the evolution and structure of the mixed layer indicate that its height rises from 100 meters during the morning (8 am) to over 2000 meters al 5 pm. results consistently show that the maximum in ozone concentration is not observed al the surface, but al about 700 m on average about it near midday. The peak, with an average concentration over the observational period of 167 ppb, appears to be a transient feature, with concentrations becoming more uniform with height in the afternoon. The vertical profiles of nitrogen oxides and sulphur dioxide indicate that concentrations are highest during the morning and steadily decrease with height, suggesting that sources for these species are located near the surface, as was expected. There appears to be no correlation between the amount of nitrogen oxides observed during the take-off and the ozone concentrations observed during landing (2-3 hours later). When the variables are normalized by the mixed layer height the results indicate that the ozone observed is fairly independent of the nitrogen oxide concentrations observed earlier. A reduced range of values of the ratio of ozone accumulated in the mixed layer and the layer height is consistently day found during the observational period. Aerosol particles near the surface show maximum concentration during the morning hours, but in contrast, during the course of the day, there is a marked increase in their concentrations at higher levels in the boundary layer suggesting that possibly gas to particle conversion is responsible for the observed increase. [Spanish] El problema de la contaminacion del aire en la Ciudad de

  12. Palaeosol control on groundwater flow and pollutant distribution: the example of arsenic.

    Science.gov (United States)

    McArthur, John M; Nath, Bibhash; Banerjee, Dhiraj M; Purohit, R; Grassineau, N

    2011-02-15

    The consumption of groundwater polluted by arsenic (As) has a severe and adverse effect on human health, particularly where, as happens in parts of SE Asia, groundwater is supplied largely from fluvial/deltaic aquifers. The lateral distribution of the As-pollution in such aquifers is heterogeneous. The cause of the heterogeneity is obscure. The location and severity of the As-pollution is therefore difficult to predict, despite the importance of such predictions to the protection of consumer health, aquifer remediation, and aquifer development. To explain the heterogeneity, we mapped As-pollution in groundwater using 659 wells across 102 km(2) of West Bengal, and logged 43 boreholes, to reveal that the distribution of As-pollution is governed by subsurface sedimentology. Across 47 km(2) of contiguous palaeo-interfluve, we found that the shallow aquifer (channels, the palaeosol is absent, so invasion of the aquifer by As and dissolved organic matter can occur, so palaeo-channel groundwater is mostly polluted by As (>50 μg/L). The role of palaeosols and, in particular, the LGMP, has been overlooked as a control on groundwater flow and pollutant movement in deltaic and coastal aquifers worldwide. Models of pollutant infiltration in such environments must include the appreciation that, where the LGMP (or other palaeosols) are present, recharge moves downward in palaeo-channel regions that are separated by palaeo-interfluvial regions where vertical recharge to underlying aquifers cannot occur and where horizontal flow occurs above the LGMP and any aquifer it caps.

  13. Some important results from the air pollution distribution model STACKS (1988-1992)

    International Nuclear Information System (INIS)

    Erbrink, J.J.

    1993-01-01

    Attention is paid to the results of the study on the distribution of air pollutants by high chimney-stacks of electric power plants. An important product of the study is the integrated distribution model STACKS (Short Term Air-pollutant Concentrations Kema modelling System). The improvements and the extensions of STACKS are described in relation to the National Model, which has been used to estimate the environmental effects of individual chimney-stacks. The National Model shows unacceptable variations for high pollutant sources. Based on the results of STACKS revision of the National model has been taken into consideration. By means of the revised National Model a more realistic estimation of the environmental effects of electric power plants can be carried out

  14. A Random Forest Approach to Predict the Spatial Distribution of Sediment Pollution in an Estuarine System

    Science.gov (United States)

    Modeling the magnitude and distribution of sediment-bound pollutants in estuaries is often limited by incomplete knowledge of the site and inadequate sample density. To address these modeling limitations, a decision-support tool framework was conceived that predicts sediment cont...

  15. The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jingqing [College of Engineering and Architecture, Zhejiang University, Hangzhou 310058 (China); Chen, Huanyu [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Binhai Industrial Technology Research Institute of Zhejiang University, Tianjin 300000 (China); Yao, Lingdan; Wei, Zongyuan [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Lou, Liping, E-mail: loulp@zju.edu.cn [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda [Environmental Protection Agency, Office of Research and Development, NRMRL, Cincinnati, OH 45220 (United States); Hu, Baolan [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Zhou, Xiaoyan [Shaoxing Water Environmental Science Institute Co. Ltd, Zhejiang 312000 (China)

    2016-11-05

    Highlights: • First investigating the spatial distribution of pollutants in pipe-scale. • Spatial distribution of heavy metals indicated their sources were different. • Three main factors effete the distribution of pollutants. • Organic deposits mainly included microbial and microalgae metabolites. - Abstract: In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600 mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography–Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better.

  16. The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system

    International Nuclear Information System (INIS)

    Liu, Jingqing; Chen, Huanyu; Yao, Lingdan; Wei, Zongyuan; Lou, Liping; Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda; Hu, Baolan; Zhou, Xiaoyan

    2016-01-01

    Highlights: • First investigating the spatial distribution of pollutants in pipe-scale. • Spatial distribution of heavy metals indicated their sources were different. • Three main factors effete the distribution of pollutants. • Organic deposits mainly included microbial and microalgae metabolites. - Abstract: In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600 mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography–Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better.

  17. Comparison of phosphorus fraction distribution and influencing factors of suspended and surface sediments in the Tiaoxi watershed, China.

    Science.gov (United States)

    Ye, Hongmeng; Yuan, Xuyin; Han, Lei; Yin, Heng; Jin, Jing

    2017-05-01

    Suspended and surface sediments from the Tiaoxi watershed, fed by the Xitiaoxi and Dongtiaoxi rivers, were analyzed for total phosphorus (TP) and the inorganic P fractions of loosely adsorbed P that were extractable with NH 4 Cl (NH 4 Cl-P), reductant P (BD-P), metal oxide-bound P extractable with NaOH (NaOH-P), and calcium-bound, HCl-extractable P (HCl-P), while other physicochemical compositions were also determined. The spatial variations of P fractions in these sediments were investigated, and the major factors influencing the various fractions were explored by multivariate statistics. Compared to surface sediments, suspended sediments contained considerably higher concentrations of total nitrogen, TP, organic matter, Al, Fe, Mn and biologically available P (BAP, given as NH 4 Cl-P, BD-P and NaOH-P combined) and lower concentrations of Si, Ca and HCl-P in the studied catchments. Dongtiaoxi sediments had higher TP, inorganic phosphorus and HCl-P concentrations and a lower BAP content compared with Xitiaoxi sediments, trends that were associated with local geological backgrounds, landscapes and anthropogenic characteristics. The results of principal component analysis showed different effects of sediment properties on P fraction distributions for Xitiaoxi and Dongtiaoxi sediments. The sediment components and structure exert a strong influence on BAP in Xitiaoxi sediments, in contrast to Dongtiaoxi sediments, where P fractions are mainly affected by urbanization and other anthropogenic activities such as shipping.

  18. Valuing the Potential Benefits of Water Quality Improvements in Watersheds Affected by Non-Point Source Pollution

    Directory of Open Access Journals (Sweden)

    Sergio Alvarez

    2016-03-01

    Full Text Available Nonpoint source (NPS pollution has been identified by the US Environmental Protection Agency (EPA as “the nation’s largest water quality problem”. Urban development, septic systems, and agricultural operations have been identified as the major sources of diffuse pollution in surface and ground water bodies. In recent decades, urban and agricultural Best Management Practices (BMP have been developed in several states to address agricultural water quality and water use impacts, including the reduction of nutrient loads to help meet water quality standards. Compliance with BMPs is associated with some costs to local governments, homeowners, and agricultural operations, but the improvements in water quality associated with BMP adoption are expected to yield significant benefits to society in the form of improved recreational opportunities, navigation, flood control, and ecosystem health. The development of sound policies and decision making processes require balancing the costs of BMP adoption to the agricultural operations with the social benefits to be derived from the improved water quality. In this paper we develop a benefits transfer model to provide estimates of the economic benefits of properly implemented and effective Best Management Practices (BMP throughout the state of Florida. These benefit estimates can be used in a cost-benefit framework to determine the optimal level of BMP adoption throughout the state of Florida and provide a framework for other regions to estimate the potential benefits of BMP-mediated water quality improvements.

  19. 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

  20. Effects of canyon geometry on the distribution of traffic-related air pollution in a large urban area: Implications of a multi-canyon air pollution dispersion model

    Science.gov (United States)

    Fu, Xiangwen; Liu, Junfeng; Ban-Weiss, George A.; Zhang, Jiachen; Huang, Xin; Ouyang, Bin; Popoola, Olalekan; Tao, Shu

    2017-09-01

    Street canyons are ubiquitous in urban areas. Traffic-related air pollutants in street canyons can adversely affect human health. In this study, an urban-scale traffic pollution dispersion model is developed considering street distribution, canyon geometry, background meteorology, traffic assignment, traffic emissions and air pollutant dispersion. In the model, vehicle exhausts generated from traffic flows first disperse inside street canyons along the micro-scale wind field generated by computational fluid dynamics (CFD) model. Then, pollutants leave the street canyon and further disperse over the urban area. On the basis of this model, the effects of canyon geometry on the distribution of NOx and CO from traffic emissions were studied over the center of Beijing. We found that an increase in building height leads to heavier pollution inside canyons and lower pollution outside canyons at pedestrian level, resulting in higher domain-averaged concentrations over the area. In addition, canyons with highly even or highly uneven building heights on each side of the street tend to lower the urban-scale air pollution concentrations at pedestrian level. Further, increasing street widths tends to lead to lower pollutant concentrations by reducing emissions and enhancing ventilation simultaneously. Our results indicate that canyon geometry strongly influences human exposure to traffic pollutants in the populated urban area. Carefully planning street layout and canyon geometry while considering traffic demand as well as local weather patterns may significantly reduce inhalation of unhealthy air by urban residents.

  1. Distribution of 238Pu and 239240Pu in aquatic macrophytes from a midwestern watershed

    International Nuclear Information System (INIS)

    Wayman, C.W.; Bartelt, G.E.; Alberts, J.J.

    1977-01-01

    Aquatic macrophytes were collected in the Great Miami River, Ohio, above and below Miamisburg and in the canal and ponds, near the Mound Laboratory, which contain sediments of a high activity (approximately 10 3 to 10 6 times) relative to the river sediments. Macrophytes collected in the river below Miamisburg have higher activities of 238 Pu than those collected from above the city. Macrophytes from the canal and ponds contain high specific activities of 238 Pu and 239 , 240 Pu with the exception of cattails grown in the ponds. Concentration factors are reported and discussed with reference to possible modes of plutonium accumulation and distribution within the plants

  2. Modelling the bidirectional reflectance distribution function (BRDF) of seawater polluted by an oil film.

    Science.gov (United States)

    Otremba, Zbigniew; Piskozub, Jacek

    2004-04-19

    The Bi-directional Reflectance Distribution Function (BRDF) of both clean seawaters and those polluted with oil film was determined using the Monte Carlo radiative transfer technique in which the spectrum of complex refractive index of Romashkino crude oil and the optical properties of case II water for chosen wavelengths was considered. The BRDF values were recorded for 1836 solid angular sectors of throughout the upper hemisphere. The visibility of areas polluted with oil observed from various directions and for various wavelengths is discussed.

  3. [Environment spatial distribution of mercury pollution in Songhua River upstream gold mining areas].

    Science.gov (United States)

    Zou, Ting-Ting; Wang, Ning; Zhang, Gang; Zhao, Dan-Dan

    2010-09-01

    Using Zeeman mercury spectrometer RA915+ monitoring the total gaseous mercury concentration were collected from gold mining area in Huadian, in the upper reaches of the Songhua River, during summer and autumn of 2008, where we simultaneously collected samples of air, water, sediment and soil. The research is focused on analyzing of the spatial and temporal distribution characteristics of atmospheric mercury pollution and the correlation with other environmental factors. The results show that: the concentration of atmospheric mercury in summer is higher than that in autumn and in the evening is higher than at noon, and it present a gradual decay with the distance to the gold mining area as the center point increasing. The distribution rule of mercury pollution of environmental factors in the gold mining area is: in sediment > in soil > in plant > in water, the characteristics of mercury pollution distribution in plant is: root > stem and leaf, and the content of mercury in plant in autumn is commonly higher than that in summer. This is thought due to the accumulation of pollutant element from soil during the growth of plant. The atmospheric mercury has a significant correlation with the root of plant, respectively 0.83 in summer and 0.97 in autumn.

  4. [Coupling SWAT and CE-QUAL-W2 models to simulate water quantity and quality in Shanmei Reservoir watershed].

    Science.gov (United States)

    Liu, Mei-Bing; Chen, Dong-Ping; Chen, Xing-Wei; Chen, Ying

    2013-12-01

    A coupled watershed-reservoir modeling approach consisting of a watershed distributed model (SWAT) and a two-dimensional laterally averaged model (CE-QUAL-W2) was adopted for simulating the impact of non-point source pollution from upland watershed on water quality of Shanmei Reservoir. Using the daily serial output from Shanmei Reservoir watershed by SWAT as the input to Shanmei Reservoir by CE-QUAL-W2, the coupled modeling was calibrated for runoff and outputs of sediment and pollutant at watershed scale and for elevation, temperature, nitrate, ammonium and total nitrogen in Shanmei Reservoir. The results indicated that the simulated values agreed fairly well with the observed data, although the calculation precision of downstream model would be affected by the accumulative errors generated from the simulation of upland model. The SWAT and CE-QUAL-W2 coupled modeling could be used to assess the hydrodynamic and water quality process in complex watershed comprised of upland watershed and downstream reservoir, and might further provide scientific basis for positioning key pollution source area and controlling the reservoir eutrophication.

  5. A non-conventional watershed partitioning method for semi-distributed hydrological modelling: the package ALADHYN

    Science.gov (United States)

    Menduni, Giovanni; Pagani, Alessandro; Rulli, Maria Cristina; Rosso, Renzo

    2002-02-01

    The extraction of the river network from a digital elevation model (DEM) plays a fundamental role in modelling spatially distributed hydrological processes. The present paper deals with a new two-step procedure based on the preliminary identification of an ideal drainage network (IDN) from contour lines through a variable mesh size, and the further extraction of the actual drainage network (AND) from the IDN using land morphology. The steepest downslope direction search is used to identify individual channels, which are further merged into a network path draining to a given node of the IDN. The contributing area, peaks and saddles are determined by means of a steepest upslope direction search. The basin area is thus partitioned into physically based finite elements enclosed by irregular polygons. Different methods, i.e. the constant and variable threshold area methods, the contour line curvature method, and a topologic method descending from the Hortonian ordering scheme, are used to extract the ADN from the IDN. The contour line curvature method is shown to provide the most appropriate method from a comparison with field surveys. Using the ADN one can model the hydrological response of any sub-basin using a semi-distributed approach. The model presented here combines storm abstraction by the SCS-CN method with surface runoff routing as a geomorphological dispersion process. This is modelled using the gamma instantaneous unit hydrograph as parameterized by river geomorphology. The results are implemented using a project-oriented software facility for the Analysis of LAnd Digital HYdrological Networks (ALADHYN).

  6. Wireless Distributed Environmental Sensor Networks for Air Pollution Measurement-The Promise and the Current Reality.

    Science.gov (United States)

    Broday, David M

    2017-10-02

    The evaluation of the effects of air pollution on public health and human-wellbeing requires reliable data. Standard air quality monitoring stations provide accurate measurements of airborne pollutant levels, but, due to their sparse distribution, they cannot capture accurately the spatial variability of air pollutant concentrations within cities. Dedicated in-depth field campaigns have dense spatial coverage of the measurements but are held for relatively short time periods. Hence, their representativeness is limited. Moreover, the oftentimes integrated measurements represent time-averaged records. Recent advances in communication and sensor technologies enable the deployment of dense grids of Wireless Distributed Environmental Sensor Networks for air quality monitoring, yet their capability to capture urban-scale spatiotemporal pollutant patterns has not been thoroughly examined to date. Here, we summarize our studies on the practicalities of using data streams from sensor nodes for air quality measurement and the required methods to tune the results to different stakeholders and applications. We summarize the results from eight cities across Europe, five sensor technologies-three stationary (with one tested also while moving) and two personal sensor platforms, and eight ambient pollutants. Overall, few sensors showed an exceptional and consistent performance, which can shed light on the fine spatiotemporal urban variability of pollutant concentrations. Stationary sensor nodes were more reliable than personal nodes. In general, the sensor measurements tend to suffer from the interference of various environmental factors and require frequent calibrations. This calls for the development of suitable field calibration procedures, and several such in situ field calibrations are presented.

  7. STRUCTURE IN THE 3D GALAXY DISTRIBUTION. II. VOIDS AND WATERSHEDS OF LOCAL MAXIMA AND MINIMA

    International Nuclear Information System (INIS)

    Way, M. J.; Gazis, P. R.; Scargle, Jeffrey D.

    2015-01-01

    The major uncertainties in studies of the multi-scale structure of the universe arise not from observational errors but from the variety of legitimate definitions and detection methods for individual structures. To facilitate the study of these methodological dependencies, we have carried out 12 different analyses defining structures in various ways. This has been done in a purely geometrical way by utilizing the HOP algorithm as a unique parameter-free method of assigning groups of galaxies to local density maxima or minima. From three density estimation techniques (smoothing kernels, Bayesian blocks, and self-organizing maps) applied to three data sets (the Sloan Digital Sky Survey Data Release 7, the Millennium simulation, and randomly distributed points) we tabulate information that can be used to construct catalogs of structures connected to local density maxima and minima. We also introduce a void finder that utilizes a method to assemble Delaunay tetrahedra into connected structures and characterizes regions empty of galaxies in the source catalog

  8. Estimation of watershed-level distributed forest structure metrics relevant to hydrologic modeling using LiDAR and Landsat

    Science.gov (United States)

    Varhola, Andrés; Coops, Nicholas C.

    2013-04-01

    SummaryA detailed characterization of vegetation structure is fundamental for physically-based hydrologic models to simulate various processes that determine rates of snow accumulation and ablation, evapotranspiration and water dynamics. However, major efforts focused on developing complex equations to describe hydrologic processes as a function of vegetation structure at the plot level have not been accompanied by corresponding attempts to adequately extrapolate these metrics over the wider landscape in order to parameterize fully-distributed models. Recent advances in remote sensing technologies offer alternatives to overcome these difficulties and therefore improve our capacity to monitor vegetation and hydrologic processes extensively. Airborne Laser Scanning (ALS) stands out as the most promising tool to provide detailed, 3-dimensional representations of vegetation from which a wide array of structural metrics can be estimated. On the other hand, moderate scale optical remote sensing imagery such as Landsat Thematic Mapper (TM) offers the capacity to extrapolate these metrics across the landscape by virtue of its spatial and temporal resolutions. Here we correlate ALS-derived forest cover (FC), tree height (H), leaf area index (LAI) and sky view-factor (SVF) - the four main structural parameters used by hydrologic models - with a suite of spectral indices obtained from six spectral bands of a Landsat 5 TM image. Despite numerous sources of variation that affect the relationships between 2-dimensional spectral indices and three-dimensional structural metrics, models to predict FC, H, LAI and SVF with reasonable accuracy were developed. The extrapolation of these variables across a watershed in British Columbia severely affected by insect disturbance resulted in highly-detailed 30 m spatial resolution maps and frequency distributions consistent with the natural variation ranges of each metric - a major improvement compared to traditional approaches that use

  9. Spatial distribution of pollutants in the area of the former CHP plant

    Science.gov (United States)

    Cichowicz, Robert

    2018-01-01

    The quality of atmospheric air and level of its pollution are now one of the most important issues connected with life on Earth. The frequent nuisance and exceedance of pollution standards often described in the media are generated by both low emission sources and mobile sources. Also local organized energy emission sources such as local boiler houses or CHP plants have impact on air pollution. At the same time it is important to remember that the role of local power stations in shaping air pollution immission fields depends on the height of emitters and functioning of waste gas treatment installations. Analysis of air pollution distribution was carried out in 2 series/dates, i.e. 2 and 10 weeks after closure of the CHP plant. In the analysis as a reference point the largest intersection of streets located in the immediate vicinity of the plant was selected, from which virtual circles were drawn every 50 meters, where 31 measuring points were located. As a result, the impact of carbon dioxide, hydrogen sulfide and ammonia levels could be observed and analyzed, depending on the distance from the street intersection.

  10. Modeling the distribution of pollutant transports at a landfill site, Perak, Malaysia

    International Nuclear Information System (INIS)

    Roslanzairi Mostapa; Mohd Tadza Abdul Rahman; Kamarudin Samuding; Lakam Mejus; Nazrul Hizam Yusoff; Mohd Rifaie Mohd Murtadza

    2006-01-01

    This paper explains the distribution of pollutant transports at a landfill site, Taiping, Perak using a computer modeling software after a series of data collection by the means of hydrogeochemical method for the purpose of data entry into the software. The main objective of this modeling is to elucidate the lateral and vertical movement of the pollutant caused by the leachate from the land filling process. Results from the hydrogeochemical sampling and hydrogeological data obtained during the boreholes construction will be used to delineate the pollutant movement using MODFLOW software and also to verify the modeling output. The hydrogeochemical method involved the sampling of surface water and groundwater at various locations within the study area. The parameters that were taken into considerations are heavy metals i.e. Pb, Cd, As, Zn, Mn, Cr and Fe. Besides that, the values of Total Dissolved Solid (TDS), conductivity and pH were also determined. A period of two years of modeling duration starting from January 2003 data will be entered into the computer software. From the modeling output it was found that vertical penetration for the pollutant reaches up to the depth of 25 meters and the pollutant is moving in the south direction before been sinked at the river and further been diluted there. This can be confirmed by the river sampling results

  11. Effects of Building‒roof Cooling on Flow and Distribution of Reactive Pollutants in street canyons

    Science.gov (United States)

    Park, S. J.; Choi, W.; Kim, J.; Jeong, J. H.

    2016-12-01

    The effects of building‒roof cooling on flow and dispersion of reactive pollutants were investigated in the framework of flow dynamics and chemistry using a coupled CFD‒chemistry model. For this, flow characteristics were analyzed first in street canyons in the presence of building‒roof cooling. A portal vortex was generated in street canyon, producing dominant reverse and outward flows near the ground in all the cases. The building‒roof cooling increased horizontal wind speeds at the building roof and strengthened the downward motion near the downwind building in the street canyon, resultantly intensifying street canyon vortex strength. The flow affected the distribution of primary and secondary pollutants. Concentrations of primary pollutants such as NOx, VOC and CO was high near the upwind building because the reverse flows were dominant at street level, making this area the downwind region of emission sources. Concentration of secondary pollutant such as O3 was lower than the background near the ground, where NOX concentrations were high. Building‒roof cooling decreased the concentration of primary pollutants in contrasted to those under non‒cooling conditions. In contrast, building‒roof cooling increased O3 by reducing NO concentrations in urban street canyon compared to concentrations under non‒cooling conditions.

  12. [Distribution Characteristics and Pollution Status Evaluation of Sediments Nutrients in a Drinking Water Reservoir].

    Science.gov (United States)

    Huang, Ting-lin; Liu, Fei; Shi, Jian-chao

    2016-01-15

    The main purpose of this paper is to illustrate the influence of nutrients distribution in sediments on the eutrophication of drinking water reservoir. The sediments of three representative locations were field-sampled and analyzed in laboratory in March 2015. The distribution characteristics of TOC, TN and TP were measured, and the pollution status of sediments was evaluated by the comprehensive pollution index and the manual for sediment quality assessment. The content of TOC in sediments decreased with depth, and there was an increasing trend of the nitrogen content. The TP was enriched in surface sediment, implying the nutrients load in Zhoucun Reservoir was aggravating as the result of human activities. Regression analysis indicated that the content of TOC in sediments was positively correlated with contents of TN and TP in sediments. The TOC/TN values reflected that the vascular land plants, which contain cellulose, were the main source of organic matter in sediments. The comprehensive pollution index analysis result showed that the surface sediments in all three sampling sites were heavily polluted. The contents of TN and TP of surface sediments in three sampling sites were 3273-4870 mg x kg(-1) and 653-2969 mg x kg(-1), and the content of TOC was 45.65-83.00 mg x g(-1). According to the manual for sediment quality assessment, the TN, TP and TOC contents in sediments exceed the standard values for the lowest level of ecotoxicity, so there is a risk of eutrophication in Zhoucun Reservoir.

  13. Modelling transport of storm-water pollutants using the distributed Multi-Hydro platform on an urban catchment near Paris

    Science.gov (United States)

    Hong, Yi; Bonhomme, Celine; Giangola-Murzyn, Agathe; Schertzer, Daniel; Chebbo, Ghassan

    2015-04-01

    Nowadays, the increasingly use of vehicles causes expanding contaminated storm-water runoff from roads and the associated quarters. Besides, the current utilization of city's separated sewer systems underlines the needs for evaluating precisely the growing impact of these polluted effluents on receiving water bodies. Nevertheless, traditional means of water quality modelling had shown its limits (Kanso, 2004), more accurate modelling schemes are hence required. In this paper, we found that the application of physically based and fully distributed model coupled with detailed high-resolution data is a promising approach to reproduce the various dynamics and interactions of water quantity/quality processes in urban or peri-urban environment. Over recent years, the physically based and spatially distributed numerical platform Multi-Hydro (MH) has been developed at Ecole des Ponts ParisTech (El-Tabach et al. , 2009 ; Gires et al., 2013 ; Giangola-Murzyn et al., 2014). This platform is particularly adapted for representing the hydrological processes for medium size watersheds, including the surface runoff, drainage water routing and the infiltrations on permeable zones. It is formed by the interactive coupling of several independent modules, which depend on generally used open-access models. In the framework of the ANR (French National Agency for Research) Trafipollu project, a new extension of MH, MH-quality, was set up for the water-quality modelling. MH-quality was used for the simulation of pollutant transport on a peri-urban and highly trafficked catchment located near Paris (Le Perreux-sur-Marne, 0.2 km2). The set-up of this model is based on the detailed description of urban land use features. For this purpose, 15 classes of urban land uses relevant to water quality modelling were defined in collaboration with the National Institute of Geography of France (IGN) using Digital Orthophoto Quadrangles (5cm). The delimitation of the urban catchment was then performed

  14. Lichen and bryophyte distribution on oak in London in relation to air pollution and bark acidity

    International Nuclear Information System (INIS)

    Larsen, R.S.; Bell, J.N.B.; James, P.W.; Chimonides, P.J.; Rumsey, F.J.; Tremper, A.; Purvis, O.W.

    2007-01-01

    Epiphytic lichen and bryophyte distribution and frequency were investigated on the trunks of 145 young oak trees throughout London and surrounding counties, and compared with pollution levels and bark pH. Sixty-four lichen and four bryophyte species were recorded. Three major zones were identified: (i) two central regions with a few lichens, bryophytes absent; (ii) a surrounding region with a more diverse flora including a high cover of nitrophyte lichens; and (iii) an outer region, characterised by species absent from central London, including acidophytes. Nineteen species were correlated with nitrogen oxides and 16 with bark pH, suggesting that transport-related pollution and bark acidity influence lichen and bryophyte distribution in London today. Lichens and bryophytes are responding to factors that influence human and environmental health in London. Biomonitoring therefore has a practical role to assess the effects of measures to improve London's air quality. - Transport-related pollutants and bark acidity influence lichen and bryophyte distribution and abundance in London today

  15. Spatially-Distributed Stream Flow and Nutrient Dynamics Simulations Using the Component-Based AgroEcoSystem-Watershed (AgES-W) Model

    Science.gov (United States)

    Ascough, J. C.; David, O.; Heathman, G. C.; Smith, D. R.; Green, T. R.; Krause, P.; Kipka, H.; Fink, M.

    2010-12-01

    The Object Modeling System 3 (OMS3), currently being developed by the USDA-ARS Agricultural Systems Research Unit and Colorado State University (Fort Collins, CO), provides a component-based environmental modeling framework which allows the implementation of single- or multi-process modules that can be developed and applied as custom-tailored model configurations. OMS3 as a “lightweight” modeling framework contains four primary foundations: modeling resources (e.g., components) annotated with modeling metadata; domain specific knowledge bases and ontologies; tools for calibration, sensitivity analysis, and model optimization; and methods for model integration and performance scalability. The core is able to manage modeling resources and development tools for model and simulation creation, execution, evaluation, and documentation. OMS3 is based on the Java platform but is highly interoperable with C, C++, and FORTRAN on all major operating systems and architectures. The ARS Conservation Effects Assessment Project (CEAP) Watershed Assessment Study (WAS) Project Plan provides detailed descriptions of ongoing research studies at 14 benchmark watersheds in the United States. In order to satisfy the requirements of CEAP WAS Objective 5 (“develop and verify regional watershed models that quantify environmental outcomes of conservation practices in major agricultural regions”), a new watershed model development approach was initiated to take advantage of OMS3 modeling framework capabilities. Specific objectives of this study were to: 1) disaggregate and refactor various agroecosystem models (e.g., J2K-S, SWAT, WEPP) and implement hydrological, N dynamics, and crop growth science components under OMS3, 2) assemble a new modular watershed scale model for fully-distributed transfer of water and N loading between land units and stream channels, and 3) evaluate the accuracy and applicability of the modular watershed model for estimating stream flow and N dynamics. The

  16. Pollution distribution of heavy metals in surface soil at an informal electronic-waste recycling site.

    Science.gov (United States)

    Fujimori, Takashi; Takigami, Hidetaka

    2014-02-01

    We studied distribution of heavy metals [lead (Pb), copper (Cu) and zinc (Zn)] in surface soil at an electronic-waste (e-waste) recycling workshop near Metro Manila in the Philippines to evaluate the pollution size (spot size, small area or the entire workshop), as well as to assess heavy metal transport into the surrounding soil environment. On-site length-of-stride-scale (~70 cm) measurements were performed at each surface soil point using field-portable X-ray fluorescence (FP-XRF). The surface soil at the e-waste recycling workshop was polluted with Cu, Zn and Pb, which were distributed discretely in surface soil. The site was divided into five areas based on the distance from an entrance gate (y-axis) of the e-waste recycling workshop. The three heavy metals showed similar concentration gradients in the y-axis direction. Zn, Pb and Cu concentrations were estimated to decrease to half of their maximum concentrations at ~3, 7 and 7 m from the pollution spot, respectively, inside the informal e-waste recycling workshop. Distance from an entrance may play an important role in heavy metal transport at the soil surface. Using on-site FP-XRF, we evaluated the metal ratio to characterise pollution features of the solid surface. Variability analysis of heavy metals revealed vanishing surficial autocorrelation over metre ranges. Also, the possibility of concentration prediction at unmeasured points using geostatistical kriging was evaluated, and heavy metals had a relative "small" pollution scales and remained inside the original workshop compared with toxic organohalogen compounds. Thus, exposure to heavy metals may directly influence the health of e-waste workers at the original site rather than the surrounding habitat and environmental media.

  17. [Distribution of Urban Soil Heavy Metal and Pollution Evaluation in Different Functional Zones of Yinchuan City].

    Science.gov (United States)

    Wang, You-qi; Bai, Yi-ru; Wang, Jian-yu

    2016-02-15

    Surface soil samples (0-20 cm) from eight different functional areas in Yinchuan city were collected. There were 10 samples respectively in each functional area. The urban soil heavy metals (Zn, Cd, Pb, Mn, Cu and Cr) pollution characteristics and sources in eight different functional areas were evaluated by mathematical statistics and geostatistical analysis method. Meanwhile, the spatial distributions of heavy metals based on the geography information system (GIS) were plotted. The average values of total Zn, Cd, Pb, Mn, Cu and Cr were 74.87, 0.15, 29.02, 553.55, 40.37 and 80.79 mg x kg(-1), respectively. The results showed that the average value of soil heavy metals was higher than the soil background value of Ningxia, which indicated accumulation of the heavy metals in urban soil. The single factor pollution index of soil heavy metals was in the sequence of Cu > Pb > Zn > Cr > Cd > Mn. The average values of total Zn, Cd, Pb and Cr were higher in north east, south west and central city, while the average values of Mn and Cu were higher in north east and central city. There was moderate pollution in road and industrial area of Yinchuan, while the other functional areas showed slight pollution according to Nemoro synthesis index. The pollution degree of different functional areas was as follows: road > industrial area > business district > medical treatment area > residential area > public park > development zone > science and education area. The results indicated that the soil heavy metal pollution condition in Yinchuan City has been affected by human activities with the development of economy.

  18. Areal distribution of 60Co, 137Cs, and 90Sr in streambed gravels of White Oak Creek Watershed, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Cerling, T.E.; Spalding, B.P.

    1981-01-01

    The concentrations of 90 Sr, 60 Co, and 137 Cs in streambed gravels from contaminated drainages in White Oak Creek Watershed were determined. Methods to determine the relative contributions of various sources to the total discharge from the watershed were developed. Principal sources of 90 Sr were: ORNL plant effluents (50%), leaching from solid waste disposal area (SWDA) 4 (30%), and leaching from SWDA 5 (10%). Minor sources included SWDA 3, the Molten Salt Reactor Facility, and intermediate-level liquid waste pit 1 with each representing 4% or less of the total basin discharge. The cooling water effluent from the High-Flux Isotope Reactor was the dominant source of 60 Co contamination in the watershed. ORNL plant effluents accounted for almost all the 137 Cs discharge from White Oak Creek basin. Downstream radionuclide concentrations were constant until significant dilution by other tributaries occurred. Any future activities giving rise to additional contamination can now be identified. Distribution coefficients between streambed gravels and streamwater for 85 Sr, 60 Co, and 137 Cs were 50, 560, and 8460 ml/g, respectively. An abridged radiochemical fractionation developed for 90 Sr was found to be as accurate and precise for these samples as the standard 90 Sr method above levels of 2 dpm/g

  19. The quantification and distribution of pollution Pb at a woodland in rural south central Ontario, Canada

    International Nuclear Information System (INIS)

    Watmough, Shaun A.; Hutchinson, Thomas C.

    2004-01-01

    Lead concentrations and Pb isotope ratios were measured in the forest floor, mineral soil and vegetation at a white pine and a sugar maple stand in a woodland in south central Ontario. Lead concentrations decreased and 206 Pb/ 207 Pb ratios increased with mineral soil depth reflecting the mixing of pollution and natural Pb sources. Lead concentrations and 206 Pb/ 207 Pb ratios at 20-30 cm depth were ∼6-7 mg/kg and 1.31-1.32, respectively. Assuming an integrated 206 Pb/ 207 Pb ratio in deposition over time of 1.18, estimated from lichen measurements and published data for the region, approximately 65% of Pb in the surface (0-1 cm) mineral soil is from anthropogenic sources. Approximately 90% of pollution Pb is found in the 0-10 cm soil layer (Ah) and less than 3% of the pollution Pb is present in the forest biomass and mull-type forest floor combined. Despite low Pb concentrations in vegetation ( 2 , respectively. - The distribution of pollution lead was determined at a woodland through the use of stable leads isotopes

  20. The impacts of changing transport and precipitation on pollutant distributions in a future climate

    Science.gov (United States)

    Fang, Yuanyuan; Fiore, Arlene M.; Horowitz, Larry W.; Gnanadesikan, Anand; Held, Isaac; Chen, Gang; Vecchi, Gabriel; Levy, Hiram

    2011-09-01

    Air pollution (ozone and particulate matter in surface air) is strongly linked to synoptic weather and thus is likely sensitive to climate change. In order to isolate the responses of air pollutant transport and wet removal to a warming climate, we examine a simple carbon monoxide-like (CO) tracer (COt) and a soluble version (SAt), both with the 2001 CO emissions, in simulations with the Geophysical Fluid Dynamics Laboratory chemistry-climate model (AM3) for present (1981-2000) and future (2081-2100) climates. In 2081-2100, projected reductions in lower-tropospheric ventilation and wet deposition exacerbate surface air pollution as evidenced by higher surface COt and SAt concentrations. However, the average horizontal general circulation patterns in 2081-2100 are similar to 1981-2000, so the spatial distribution of COt changes little. Precipitation is an important factor controlling soluble pollutant wet removal, but the total global precipitation change alone does not necessarily indicate the sign of the soluble pollutant response to climate change. Over certain latitudinal bands, however, the annual wet deposition change can be explained mainly by the simulated changes in large-scale (LS) precipitation. In regions such as North America, differences in the seasonality of LS precipitation and tracer burdens contribute to an apparent inconsistency of changes in annual wet deposition versus annual precipitation. As a step toward an ultimate goal of developing a simple index that can be applied to infer changes in soluble pollutants directly from changes in precipitation fields as projected by physical climate models, we explore here a "Diagnosed Precipitation Impact" (DPI) index. This index captures the sign and magnitude (within 50%) of the relative annual mean changes in the global wet deposition of the soluble pollutant. DPI can only be usefully applied in climate models in which LS precipitation dominates wet deposition and horizontal transport patterns change

  1. Particle size distribution and composition in a mechanically ventilated school building during air pollution episodes.

    Science.gov (United States)

    Parker, J L; Larson, R R; Eskelson, E; Wood, E M; Veranth, J M

    2008-10-01

    Particle count-based size distribution and PM(2.5) mass were monitored inside and outside an elementary school in Salt Lake City (UT, USA) during the winter atmospheric inversion season. The site is influenced by urban traffic and the airshed is subject to periods of high PM(2.5) concentration that is mainly submicron ammonium and nitrate. The school building has mechanical ventilation with filtration and variable-volume makeup air. Comparison of the indoor and outdoor particle size distribution on the five cleanest and five most polluted school days during the study showed that the ambient submicron particulate matter (PM) penetrated the building, but indoor concentrations were about one-eighth of outdoor levels. The indoor:outdoor PM(2.5) mass ratio averaged 0.12 and particle number ratio for sizes smaller than 1 microm averaged 0.13. The indoor submicron particle count and indoor PM(2.5) mass increased slightly during pollution episodes but remained well below outdoor levels. When the building was occupied the indoor coarse particle count was much higher than ambient levels. These results contribute to understanding the relationship between ambient monitoring station data and the actual human exposure inside institutional buildings. The study confirms that staying inside a mechanically ventilated building reduces exposure to outdoor submicron particles. This study supports the premise that remaining inside buildings during particulate matter (PM) pollution episodes reduces exposure to submicron PM. New data on a mechanically ventilated institutional building supplements similar studies made in residences.

  2. Quantifying the Interactions Between Soil Thermal Characteristics, Soil Physical Properties, Hydro-geomorphological Conditions and Vegetation Distribution in an Arctic Watershed

    Science.gov (United States)

    Dafflon, B.; Leger, E.; Robert, Y.; Ulrich, C.; Peterson, J. E.; Soom, F.; Biraud, S.; Tran, A. P.; Hubbard, S. S.

    2017-12-01

    Improving understanding of Arctic ecosystem functioning and parameterization of process-rich hydro-biogeochemical models require advances in quantifying ecosystem properties, from the bedrock to the top of the canopy. In Arctic regions having significant subsurface heterogeneity, understanding the link between soil physical properties (incl. fraction of soil constituents, bedrock depth, permafrost characteristics), thermal behavior, hydrological conditions and landscape properties is particularly challenging yet is critical for predicting the storage and flux of carbon in a changing climate. This study takes place in Seward Peninsula Watersheds near Nome AK and Council AK, which are characterized by an elevation gradient, shallow bedrock, and discontinuous permafrost. To characterize permafrost distribution where the top of permafrost cannot be easily identified with a tile probe (due to rocky soil and/or large thaw layer thickness), we developed a novel technique using vertically resolved thermistor probes to directly sense the temperature regime at multiple depths and locations. These measurements complement electrical imaging, seismic refraction and point-scale data for identification of the various thermal behavior and soil characteristics. Also, we evaluate linkages between the soil physical-thermal properties and the surface properties (hydrological conditions, geomorphic characteristics and vegetation distribution) using UAV-based aerial imaging. Data integration and analysis is supported by numerical approaches that simulate hydrological and thermal processes. Overall, this study enables the identification of watershed structure and the links between various subsurface and landscape properties in representative Arctic watersheds. Results show very distinct trends in vertically resolved soil temperature profiles and strong lateral variations over tens of meters that are linked to zones with various hydrological conditions, soil properties and vegetation

  3. Who bears the environmental burden in China? An analysis of the distribution of industrial pollution sources

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Chunbo [School of Agricultural and Resource Economics, University of Western Australia, 35 Stirling Highway, Crawley, 6009, Western Australia (Australia)

    2010-07-15

    A remaining challenge for environmental inequality researchers is to translate the principles developed in the U.S. to China which is experiencing the staggering environmental impacts of its astounding economic growth and social changes. This study builds on U.S. contemporary environmental justice literature and examines the issue of environmental inequality in China through an analysis of the geographical distribution of industrial pollution sources in Henan province. This study attempts to answer two central questions: (1) whether environmental inequality exists in China and if it does, (2) what socioeconomic lenses can be used to identify environmental inequality. The study found that: (1) race and income - the two common lenses used in many U.S. studies play different roles in the Chinese context; (2) rural residents and especially rural migrants are disproportionately exposed to industrial pollution. (author)

  4. Evaluation of statistical distributions to analyze the pollution of Cd and Pb in urban runoff.

    Science.gov (United States)

    Toranjian, Amin; Marofi, Safar

    2017-05-01

    Heavy metal pollution in urban runoff causes severe environmental damage. Identification of these pollutants and their statistical analysis is necessary to provide management guidelines. In this study, 45 continuous probability distribution functions were selected to fit the Cd and Pb data in the runoff events of an urban area during October 2014-May 2015. The sampling was conducted from the outlet of the city basin during seven precipitation events. For evaluation and ranking of the functions, we used the goodness of fit Kolmogorov-Smirnov and Anderson-Darling tests. The results of Cd analysis showed that Hyperbolic Secant, Wakeby and Log-Pearson 3 are suitable for frequency analysis of the event mean concentration (EMC), the instantaneous concentration series (ICS) and instantaneous concentration of each event (ICEE), respectively. In addition, the LP3, Wakeby and Generalized Extreme Value functions were chosen for the EMC, ICS and ICEE related to Pb contamination.

  5. Distribution and mobility of metals in contaminated sites. chemometric investigation of pollutant profiles.

    Science.gov (United States)

    Abollino, Ornella; Aceto, Maurizio; Malandrino, Mery; Mentasti, Edoardo; Sarzanini, Corrado; Barberis, Renzo

    2002-01-01

    The distribution and mobility of heavy metals in the soils of two contaminated sites in Piedmont (Italy) was investigated, evaluating the horizontal and vertical profiles of 15 metals, namely Al, Cd, Cu, Cr, Fe. La, Mn, Ni, Pb, Sc, Ti, V, Y, Zn and Zr. The concentrations in the most polluted areas of the sites were higher than the acceptable limits reported in Italian and Dutch legislations for soil reclamation. Chemometric elaboration of the results by pattern recognition techniques allowed us to identify groups of samples with similar characteristics and to find correlations among the variables. The pollutant mobility was studied by extraction with water, dilute acetic acid and EDTA and by applying Tessier's procedure. The fraction of mobile species, which potentially is the most harmful for the environment, was found to be higher than the one normally present in unpolluted soils, where heavy metals are, to a higher extent, strongly bound to the matrix.

  6. The influence of vegetation on the horizontal and vertical distribution of pollutants in a street canyon.

    Science.gov (United States)

    Salmond, J A; Williams, D E; Laing, G; Kingham, S; Dirks, K; Longley, I; Henshaw, G S

    2013-01-15

    Space constraints in cities mean that there are only limited opportunities for increasing tree density within existing urban fabric and it is unclear whether the net effect of increased vegetation in street canyons is beneficial or detrimental to urban air quality at local scales. This paper presents data from a field study undertaken in Auckland, New Zealand designed to determine the local impact of a deciduous tree canopy on the distribution of the oxides of nitrogen within a street canyon. The results showed that the presence of leaves on the trees had a marked impact on the transport of pollutants and led to a net accumulation of pollutants in the canyon below the tree tops. The incidence and magnitude of temporally localised spikes in pollutant concentration were reduced within the tree canopy itself. A significant difference in pollutant concentrations with height was not observed when leaves were absent. Analysis of the trends in concentration associated with different wind directions showed a smaller difference between windward and leeward sides when leaves were on the trees. A small relative increase in concentrations on the leeward side was observed during leaf-on relative to leaf-off conditions as predicted by previous modelling studies. However the expected reduction in concentrations on the windward side was not observed. The results suggest that the presence of leaves on the trees reduces the upwards transport of fresh vehicle emissions, increases the storage of pollutants within the canopy space and reduces the penetration of clean air downwards from aloft. Differences observed between NO and NO(2) concentrations could not be accounted for by dispersion processes alone, suggesting that there may also be some changes in the chemistry of the atmosphere associated with the presence of leaves on the trees. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system.

    Science.gov (United States)

    Liu, Jingqing; Chen, Huanyu; Yao, Lingdan; Wei, Zongyuan; Lou, Liping; Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda; Hu, Baolan; Zhou, Xiaoyan

    2016-11-05

    In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography-Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Remote sensing data to classify functional groups of vegetation and their distribution and abundance in a semiarid mountain watershed, Idaho, USA

    Science.gov (United States)

    Loughridge, R. E.; Benner, S. G.; McNamara, J. P.; Flores, A. N.

    2012-12-01

    In water-limited montane ecosystems, topography is a significant driver of energy balance and soil moisture and therefore governs the distribution and abundance of terrestrial vegetation. Few studies have made a concerted effort to quantify spatial patterns in vegetation along physiographic gradients that control microclimate such as slope, elevation, and aspect. Furthermore, spectral mixing of different vegetation species within individual visible and near-infrared remote sensing pixels makes it difficult to constrain the temporal growth and senescence of individual plant functional types. We report on a study that seeks to understand the interacting roles of topography, soil moisture, and solar radiation on the distribution of different plant functional types within the Dry Creek Experimental Watershed (DCEW). Boise State University maintains the 27 km2 watershed which is located in the Boise Front Mountains of southwest Idaho. It is qualitatively observed in DCEW that low elevations are dominated by sage-steppe ecosystems and high elevations transition to conifer forests. It is also observed that aspect has a major control in which sage-steppe is evident at high elevations on south facing slopes conversely from north facing slopes. To quantify these trends we measured percent ground cover of functional groups (i.e. forbs, grass, shrubs, etc.) at 77 sites within DCEW spanning a large gradient in the controlling biophysiographic variables. In addition, vegetation water content (VWC) and spectral reflectance from the 325 to 1075 nm wavelengths was collected for specific vegetation types at eight permanent soil moisture monitoring sites contained in DCEW throughout the 2012 green-up/senescence transition. To develop a watershed-wide classification we built a supervised multilayer perceptron (MLP) backpropagating artificial neural network (ANN) using temporal Landsat 5 images to classify 4 major groups: sage-steppe, Douglas fir, ponderosa pine, and deciduous trees

  9. Neutron activation analysis for study of distribution patterns of organo-halogen pollutants in apple

    International Nuclear Information System (INIS)

    Zhang Hong; Luo Jialing; Sun Huibin; Chai Zhifang; Chinese Academy of Sciences, Beijing

    2007-01-01

    The distribution characteristics of organo-halogens in apple and their sources were studied by neutron activation analysis combined with statistical analysis. The results indicated that concentrations of organo-halogens in apple were in the order of organo-chlorine >> organo-bromine > organo-iodine, and concentrations of the organo-chlorine in four parts of apple were in the order of seed >> peel >> endocarp ≥ pulp. Also, the organo-chlorine, -bromine and-iodine in apple were found to have different sources. The latter two were mainly from naturally synthetic products by plant itself, while the former was mainly from anthropogenic pollutants. (authors)

  10. Distribution of air pollutants in the Inn Valley atmosphere during high concentration events in winter 2006

    International Nuclear Information System (INIS)

    Schnitzhofer, R.; Norman, M; Dunkl, J.; Wistaler, A.; Hansel, A.; Neininger, B.; Gohm, A.

    2006-01-01

    Full text: The goal of the INNOX field campaign, which took place during January and February 2006 near the town of Schwaz, was to obtain a three-dimensional picture of the spatial distribution of air pollutants in the Inn Valley during wintertime. For this purpose continuous ground based measurements and, on six chosen days, vertical profiles within the lowest 200 m above ground level (AGL) of the valley atmosphere of certain VOCs (benzene, toluene, etc.) and CO were performed using a proton-transfer-reaction mass spectrometry instrument (PTR-MS). For the soundings a 200-m long teflon line was fixed on a tethered balloon through which the air was sucked to the PTR-MS instrument and to a CO analyser. Next to the inlet on the tethered balloon meteorological data, such as air temperature, pressure, wind, were measured as well. Above the lowest 200 m AGL a research aircraft from MetAir AG (Switzerland), equipped with various instruments for in-situ measurements of air pollutants and meteorological data, was operated. A typical flight pattern consisted of five vertical cross sections between about 150 to 2500 m AGL and lasted about three hours. Altogether 25 hours of aircraft measurements were carried out on six different days. The combination of low-level balloon measurements and upper-level aircraft observations yields vertical profiles of various parameters which cover the whole valley atmosphere. Preliminary results which show strong vertical but also horizontal gradients of air pollutant concentrations will be presented. (author)

  11. Multi-model evaluation of short-lived pollutant distributions over east Asia during summer 2008

    Science.gov (United States)

    Quennehen, B.; Raut, J.-C.; Law, K. S.; Daskalakis, N.; Ancellet, G.; Clerbaux, C.; Kim, S.-W.; Lund, M. T.; Myhre, G.; Olivié, D. J. L.; Safieddine, S.; Skeie, R. B.; Thomas, J. L.; Tsyro, S.; Bazureau, A.; Bellouin, N.; Hu, M.; Kanakidou, M.; Klimont, Z.; Kupiainen, K.; Myriokefalitakis, S.; Quaas, J.; Rumbold, S. T.; Schulz, M.; Cherian, R.; Shimizu, A.; Wang, J.; Yoon, S.-C.; Zhu, T.

    2016-08-01

    The ability of seven state-of-the-art chemistry-aerosol models to reproduce distributions of tropospheric ozone and its precursors, as well as aerosols over eastern Asia in summer 2008, is evaluated. The study focuses on the performance of models used to assess impacts of pollutants on climate and air quality as part of the EU ECLIPSE project. Models, run using the same ECLIPSE emissions, are compared over different spatial scales to in situ surface, vertical profiles and satellite data. Several rather clear biases are found between model results and observations, including overestimation of ozone at rural locations downwind of the main emission regions in China, as well as downwind over the Pacific. Several models produce too much ozone over polluted regions, which is then transported downwind. Analysis points to different factors related to the ability of models to simulate VOC-limited regimes over polluted regions and NOx limited regimes downwind. This may also be linked to biases compared to satellite NO2, indicating overestimation of NO2 over and to the north of the northern China Plain emission region. On the other hand, model NO2 is too low to the south and west of this region and over South Korea/Japan. Overestimation of ozone is linked to systematic underestimation of CO particularly at rural sites and downwind of the main Chinese emission regions. This is likely to be due to enhanced destruction of CO by OH. Overestimation of Asian ozone and its transport downwind implies that radiative forcing from this source may be overestimated. Model-observation discrepancies over Beijing do not appear to be due to emission controls linked to the Olympic Games in summer 2008.With regard to aerosols, most models reproduce the satellite-derived AOD patterns over eastern China. Our study nevertheless reveals an overestimation of ECLIPSE model mean surface BC and sulphate aerosols in urban China in summer 2008. The effect of the short-term emission mitigation in Beijing

  12. Multi-model evaluation of short-lived pollutant distributions over east Asia during summer 2008

    Directory of Open Access Journals (Sweden)

    B. Quennehen

    2016-08-01

    Full Text Available The ability of seven state-of-the-art chemistry–aerosol models to reproduce distributions of tropospheric ozone and its precursors, as well as aerosols over eastern Asia in summer 2008, is evaluated. The study focuses on the performance of models used to assess impacts of pollutants on climate and air quality as part of the EU ECLIPSE project. Models, run using the same ECLIPSE emissions, are compared over different spatial scales to in situ surface, vertical profiles and satellite data. Several rather clear biases are found between model results and observations, including overestimation of ozone at rural locations downwind of the main emission regions in China, as well as downwind over the Pacific. Several models produce too much ozone over polluted regions, which is then transported downwind. Analysis points to different factors related to the ability of models to simulate VOC-limited regimes over polluted regions and NOx limited regimes downwind. This may also be linked to biases compared to satellite NO2, indicating overestimation of NO2 over and to the north of the northern China Plain emission region. On the other hand, model NO2 is too low to the south and west of this region and over South Korea/Japan. Overestimation of ozone is linked to systematic underestimation of CO particularly at rural sites and downwind of the main Chinese emission regions. This is likely to be due to enhanced destruction of CO by OH. Overestimation of Asian ozone and its transport downwind implies that radiative forcing from this source may be overestimated. Model-observation discrepancies over Beijing do not appear to be due to emission controls linked to the Olympic Games in summer 2008.With regard to aerosols, most models reproduce the satellite-derived AOD patterns over eastern China. Our study nevertheless reveals an overestimation of ECLIPSE model mean surface BC and sulphate aerosols in urban China in summer 2008. The effect of the short-term emission

  13. Airflow characteristics and pollution distribution around a thermal manikin - Impact of specific personal and indoor environmental factors

    DEFF Research Database (Denmark)

    Licina, Dusan; Tham, Kwok Wai; Melikov, Arsen Krikor

    2016-01-01

    , and ventilation flow considerably affected airflow characteristics and pollution distribution around the thermal manikin. Under the specific set of conditions studied, the most favorable airflow patterns in preventing the feet pollution from reaching the breathing zone was transverse flow from the front......This study presents a summary of experimental measurements on the airflow characteristics and pollution distribution around a non-breathing thermal manikin. The two objectives are: (1) to examine the extent to which personal (body posture, clothing insulation, table positioning) and environmental...... factors (room air temperature and ventilation flow) affect the airflow characteristic (velocity and temperature) around the thermal manikin and (2) to examine the pollution distribution within the convective boundary layer (CBL) around a thermal manikin and personal exposure to two types of airborne...

  14. Seasonal, Spatial Distribution and Ecological Risk Assessment of Heavy Metals in Surface Sediments from a Watershed Area in Gonghu Bay in Taihu Lake, China

    Directory of Open Access Journals (Sweden)

    Peifang Wang

    2014-01-01

    Full Text Available Surface sediments from five stations within Gonghu Bay in Taihu Lake, China, were sampled for seasonal and spatial metal contamination analysis variations and ecological risks assessment from April 2009 to January 2010. The Contamination Factor (CF and geo-accumulation index (Igeo indicated that the sediments in Gonghu Bay ranged from unpolluted to moderately polluted, except for Cd. The one-way ANOVA analysis results showed that the Pb, Zn, Cr, and Cu concentrations were higher at station 3 (lake inlet and the Cr, Pb, and Zn concentrations were significantly higher in the spring. Additionally, using BCR¡¦s sequential extraction, the results showed that the fractionated metals Zn and Cd were observed as bioavailable fractions in the sediments, which could have potential moderate mobility in the water system. There was a significant increase in the bioavailable form during winter. The ratio of secondary and primary phrase (RSP decreased according to the order Zn > Cu > Ni > Pb > Cd > Cr. Finally, these results indicated that the sediments of Gonghu Bay were polluted by Cd, Zn, and Cu, which provides a scientific basis for effectively protecting sediments in watershed areas from long-term heavy metal accumulation.

  15. Watershed District

    Data.gov (United States)

    Kansas Data Access and Support Center — Boundaries show on this map are derived from legal descriptions contained in petitions to the Kansas Secretary of State for the creation or extension of watershed...

  16. The Distribution of Heavy Metal Pollutants in Suez Bay Using Geographic Information System (GIS)

    International Nuclear Information System (INIS)

    Hassan, H.B.; Mohamed, W.M.

    2017-01-01

    Suez city represents the southern entrance of the Suez Canal. As a result of the rapid development of industrialization and anthropogenic activities of Suez city may be entered containments such as heavy metals through Suez bay boundaries. The geographical information system (Arc GIS 9.1) is used to study the spatial distribution of heavy metals concentrations (Cd, Mn, Fe, Ni, Pb, Cu and Zn) of water samples which were collected in four different sampling sites (I, II, III and IV) from Suez bay. In this study, tabular data representation of the spatial distribution was developed using the inverse distance weighted (IDW) interpolation method. The GIS technique was applied to transfer the information into a final map illustrating the spatial distribution of heavy metals within the studied area. GIS models showed the high concentrations of heavy metals in some sites in the Suez city affecting by their activities. An overall distribution map of heavy metals is observed from GIS special analysis. Site (IV) in Suez City demonstrated the highest polluted are a in the overall distribution map

  17. STUDY OF POLLUTANT DISTRIBUTION IN BENOA BAY USING NUMERICAL SIMULATION AND SATELLITE DATA

    Directory of Open Access Journals (Sweden)

    Komang Ardana

    2012-11-01

    Full Text Available Euthrofication that caused by nitrate and phosphate contamination and also sedimentation process is the mainproblem that took place in Benoa Bay Territorial water. The distribution of phosphate pollutant in Benoa bay territorialwater was modeled by numeric of Princeton Ocean model (POM. The input of this pollutant model were a tidal currentpattern, M2 tidal current residue, biological factor, physic and chemistry, that influenced pollutant concentration.Meanwhile, the sedimentation concentration was mapped with ALOS AVNIR-2 sensor image satellite and this image wasanalysed with statistic method (Linear Regression.The result of phosphate modeling concentration was 0.1 mg/1 to 0.0022 mg/1, where the concentration wascategorized very hazardous to the territorial water environment. Because the phosphate concentration in a pollutantresources was beyond the standard level of environmental quality, that was 0.015 mg/1 for fishery cultivation and alsotourism activity (Bali Governor Regulation No.8th 2007. While, the direction of the distribution was affected by currentpattern of movement, that was when the ebb level of high water moving into the bay and when the ebb to high tidemoving out of the bay.The result of statistic approaches with ALOS of AVNIR-2 censor can be used for mapping sedimentationdistribution advantages in Benoa Bay. The values were: R2 Band 1 is 0.3839, Band 2 is 0.6123 and Band 3 is 0.5468. Inthis methodology, the correlation was not significant, due to, the quantity of in-situ data was small and the time researchwas not at the same time with satellite data.

  18. [Distribution and pollution assessment of heavy metals in soil of relocation areas from the Danjiangkou Reservoir].

    Science.gov (United States)

    Zhang, Lei; Qin, Yan-Wen; Zheng, Bing-Hui; Shi, Yao; Han, Chao-Nan

    2013-01-01

    The aim of this article is to explore the pollution level and potential ecological risk of heavy metals in soil of the relocation areas from the Danjiangkou Reservoir. The contents and spatial distribution of Cd, Pb, Cu, Zn, Cr and As in soil of the relocation areas from the Danjiangkou Reservoir were analyzed. The integrated pollution index and potential ecological risk index were used to evaluate the contamination degree and potential ecological risk of these elements. The results indicated that the average contents of Cd, Pb, Cu, Zn, Cr and As in the samples were 0.61, 23.11, 58.25, 22.65, 58.99 and 16.95 mg x kg(-1), respectively. Compared with the background value of soils from Henan province, all these 6 elements except Zn were enriched to some extent, especially Cd. Similar patterns were observed for the spatial distribution of Cu, Zn, and Pb. Compared with the contents of heavy metals in surface sediments of the typical domestic reservoirs, Cd and As in soil of the relocation areas from the Danjiangkou Reservoir were heavily accumulated. The correlation analysis showed that there were significant positive correlations among Pb, Cu, and Zn. And there was also significant positive correlation between Cr and Pb. In contrast, negative correlation was found between Cr and As. To sum up, the comprehensive assessment results showed that Cd was the primary element with high ecological risk.

  19. Ion activity and distribution of heavy metals in acid mine drainage polluted subtropical soils

    International Nuclear Information System (INIS)

    Li Yongtao; Becquer, Thierry; Dai Jun; Quantin, Cecile; Benedetti, Marc F.

    2009-01-01

    The oxidative dissolution of mine wastes gives rise to acidic, metal-enriched mine drainage (AMD) and has typically posed an additional risk to the environment. The poly-metallic mine Dabaoshan in South China is an excellent test site to understand the processes affecting the surrounding polluted agricultural fields. Our objectives were firstly to investigate metal ion activity in soil solution, distribution in solid constituents, and spatial distribution in samples, secondly to determine dominant environment factors controlling metal activity in the long-term AMD-polluted subtropical soils. Soil Column Donnan Membrane Technology (SC-DMT) combined with sequential extraction shows that unusually large proportion of the metal ions are present as free ion in the soil solutions. The narrow range of low pH values prevents any pH effects during the binding onto oxides or organic matter. The differences in speciation of the soil solutions may explain the different soil degradation observed between paddy and non-paddy soils. - First evidence of the real free metal ion concentrations in acid mine drainage context in tropical systems

  20. Watershed and discharge influences on the phase distribution and tributary loading of total mercury and methylmercury into Lake Superior

    International Nuclear Information System (INIS)

    Babiarz, Christopher; Hoffmann, Stephen; Wieben, Ann; Hurley, James; Andren, Anders; Shafer, Martin; Armstrong, David

    2012-01-01

    Knowledge of the partitioning and sources of mercury are important to understanding the human impact on mercury levels in Lake Superior wildlife. Fluvial fluxes of total mercury (Hg T ) and methylmercury (MeHg) were compared to discharge and partitioning trends in 20 sub-basins having contrasting land uses and geological substrates. The annual tributary yield was correlated with watershed characteristics and scaled up to estimate the basin-wide loading. Tributaries with clay sediments and agricultural land use had the largest daily yields with maxima observed near the peak in water discharge. Roughly 42% of Hg T and 57% of MeHg was delivered in the colloidal phase. Tributary inputs, which are confined to near-shore zones of the lake, may be more important to the food-web than atmospheric sources. The annual basin-wide loading from tributaries was estimated to be 277 kg yr −1 Hg T and 3.4 kg yr −1 MeHg (5.5 and 0.07 mg km −2 d −1 , respectively). - Highlights: ► The highest mercury yields occurred during spring melt except in forested watersheds. ► Roughly half of the mercury yield occurred in the colloidal phase. ► About 277 kg of Hg T and 3.4 kg of MeHg were delivered annually via tributaries. ► Whole-water MeHg loading was roughly equivalent to the estimated atmospheric loading. ► Watersheds with peat, loam or sandy soils deliver more MeHg than those with clays. - Tributary inputs, which are confined to the near-shore zones of Lake Superior, provide more mercury to these sensitive aquatic habitats than direct atmospheric deposition.

  1. The temporal and spatial distribution characteristics of air pollution index and meteorological elements in Beijing, Tianjin and Shijiazhuang, China.

    Science.gov (United States)

    Huading, Shi; Critto, Andrea; Torresan, Silvia; Qingxian, Gao

    2018-06-13

    With the rapid economic development and the continuous population growth, several important cities in China suffer serious air pollution, especially in the Beijing-Tianjin-Hebei economic developing area. Based on the daily air pollution index (API) and surface meteorological elements in Beijing, Tianjin and Shijiazhuang from 2001 to 2010, the relationships between API and meteorological elements were analyzed. The statistical analysis focused on the relationships at seasonal and monthly average scales, on different air pollution grades and air pollution processes. The results revealed that the air pollution conditions in the three areas gradually improved from 2001 to 2010, especially during summer; and the worst conditions in air quality were recorded in Beijing in spring due to the influences of dust, while in Tianjin and Shijiazhuang in winter due to household heating. Meteorological elements exhibited different influences on air pollution, showing similar relationships between API in monthly averages and four meteorological elements (i.e., the average, maximum and minimum temperatures, maximum air pressure, vapor pressure, and maximum wind speed); while the relationships on a seasonal average scale demonstrated significant differences. Compared with seasonal and monthly average scales of API, the relation coefficients based on different air pollution grades were significatively lower; while the relationship between API and meteorological elements based on air pollution process reduced the smoothing effect due to the average processing of seasonal and monthly API and improved the accuracy of the results based on different air pollution grades. Finally, statistical analysis of the distribution of pollution days in different wind directions indicated the directions of extreme and maximum wind speeds that mainly influence air pollution; representing a valuable information that could support the definition of air pollution control strategies through the

  2. Fifty years of watershed research on the Fernow Experimental Forest, WV: effects of forest management and air pollution on hardwood forests

    Science.gov (United States)

    M.B. Adams; P.J. Edwards; J.N. Kochenderfer; F. Wood

    2004-01-01

    In 1951, stream gaging was begun on five small headwater catchments on the Fernow Experimental Forest in West Virginia, to study the effects of forest management activities, particularly timber harvesting, on water yield and quality. Results from these watersheds, and others gaged more recently, have shown that annual water yields increase in proportion to the basal...

  3. Influence of the characteristics of atmospheric boundary layer on the vertical distribution of air pollutant in China's Yangtze River Delta

    Science.gov (United States)

    Wang, Chenggang; Cao, Le

    2016-04-01

    Air pollution occurring in the atmospheric boundary layer is a kind of weather phenomenon which decreases the visibility of the atmosphere and results in poor air quality. Recently, the occurrence of the heavy air pollution events has become more frequent all over Asia, especially in Mid-Eastern China. In December 2015, the most severe air pollution in recorded history of China occurred in the regions of Yangtze River Delta and Beijing-Tianjin-Hebei. More than 10 days of severe air pollution (Air Quality Index, AQI>200) appeared in many large cities of China such as Beijing, Tianjin, Shijiazhuang and Baoding. Thus, the research and the management of the air pollution has attracted most attentions in China. In order to investigate the formation, development and dissipation of the air pollutions in China, a field campaign has been conducted between January 1, 2015 and January 28, 2015 in Yangtze River Delta of China, aiming at a intensive observation of the vertical structure of the air pollutants in the atmospheric boundary layer during the time period with heavy pollution. In this study, the observation data obtained in the field campaign mentioned above is analyzed. The characteristics of the atmospheric boundary layer and the vertical distribution of air pollutants in the city Dongshan located in the center of Lake Taihu are shown and discussed in great detail. It is indicated that the stability of the boundary layer is the strongest during the nighttime and the early morning of Dongshan. Meanwhile, the major air pollutants, PM2.5 and PM10 in the boundary layer, reach their maximum values, 177.1μg m-3 and 285μg m-3 respectively. The convective boundary layer height in the observations ranges from approximately 700m to 1100m. It is found that the major air pollutants tend to be confined in a relatively shallow boundary layer, which represents that the boundary layer height is the dominant factor for controlling the vertical distribution of the air pollutants. In

  4. Impact of two chemistry mechanisms fully coupled with mesoscale model on the atmospheric pollutants distribution

    Science.gov (United States)

    Arteta, J.; Cautenet, S.; Taghavi, M.; Audiffren, N.

    Air quality models (AQM) consist of many modules (meteorology, emission, chemistry, deposition), and in some conditions such as: vicinity of clouds or aerosols plumes, complex local circulations (mountains, sea breezes), fully coupled models (online method) are necessary. In order to study the impact of lumped chemical mechanisms in AQM simulations, we examine the ability of both different chemical mechanisms: (i) simplified: Condensed Version of the MOdèle de Chimie Atmosphérique 2.2 (CV-MOCA2.2), and (ii) reference: Regional Atmospheric Chemistry Model (RACM), which are coupled online with the Regional Atmospheric Modeling Systems (RAMS) model, on the distribution of pollutants. During the ESCOMPTE experiment (Expérience sur Site pour COntraindre les Modèles de Pollution et de Transport d'Emissions) conducted over Southern France (including urban and industrial zones), Intensive observation periods (IOP) characterized by various meteorological and mixed chemical conditions are simulated. For both configurations of modeling, numerical results are compared with surface measurements (75 stations) for primary (NO x) and secondary (O 3) species. We point out the impact of the two different chemical mechanisms on the production of species involved in the oxidizing capacity such as ozone and radicals within urban and industrial areas. We highlight that both chemical mechanisms produce very similar results for the main pollutants (NO x and O 3) in three-dimensional (3D) distribution, despite large discrepancies in 0D modeling. For ozone concentration, we found sometimes small differences (5-10 ppb) between the mechanisms under study according to the cases (polluted or not). The relative difference between the two mechanisms over the whole domain is only -7% for ozone from CV-MOCA 2.2 versus RACM. When the order of magnitude is needed rather than an accurate estimate, a reduced mechanism is satisfactory. It has the advantage of running faster (four times less than CPU

  5. Occurrence and Distribution of Pesticides in the St. Lucie River Watershed, South-Central Florida, 2000-01, Based on Enzyme-Linked Immunosorbent Assay (ELISA) Screening

    Science.gov (United States)

    Lietz, A.C.

    2003-01-01

    The St. Lucie River watershed is a valuable estuarine ecosystem and resource in south-central Florida. The watershed has undergone extensive changes over the last century because of anthropogenic activities. These activities have resulted in a complex urban and agricultural drainage network that facilitates the transport of contaminants, including pesticides, to the primary canals and then to the estuary. Historical data indicate that aquatic life criteria for selected pesticides have been exceeded. To address this concern, a reconnaissance was conducted to assess the occurrence and distribution of selected pesticides within the St. Lucie River watershed. Numerous water samples were collected from 37 sites among various land-use categories (urban/built-up, citrus, cropland/pastureland, and inte-grated). Samples were collected at inflow points to primary canals (C-23, C-24, and C-44) and at control structures along these canals from October 2000 to September 2001. Samples were screened for four pesticide classes (triazines, chloroacetanilides, chlorophenoxy compounds, and organophosphates) by using Enzyme-Linked Immunosorbent Assay (ELISA) screening. A temporal distribution of pesticides within the watershed was made based on samples collected at the integrated sites during different rainfall events between October 2000 and September 2001. Triazines were detected in 32 percent of the samples collected at the integrated sites. Chloroacetanilides were detected in 60 percent of the samples collected at the integrated sites, with most detections occurring at one site. Chlorophenoxy compounds were detected in 17 percent of the samples collected at the integrated sites. Organophosphates were detected in only one sample. A spatial distribution and range of concentration of pesticides at the 37 sampling sites in the watershed were determined among land-use categories. Triazine concentrations ranged from highest to lowest in the citrus, urban/built-up, and integrated areas

  6. Green Infrastructure and Watershed-Scale Hydrology in a Mixed Land Cover System

    Science.gov (United States)

    Hoghooghi, N.; Golden, H. E.; Bledsoe, B. P.

    2017-12-01

    Urbanization results in replacement of pervious areas (e.g., vegetation, topsoil) with impervious surfaces such as roads, roofs, and parking lots, which cause reductions in interception, evapotranspiration, and infiltration, and increases in surface runoff (overland flow) and pollutant loads and concentrations. Research on the effectiveness of different Green Infrastructure (GI), or Low Impact Development (LID), practices to reduce these negative impacts on stream flow and water quality has been mostly focused at the local scale (e.g., plots, small catchments). However, limited research has considered the broader-scale effects of LID, such as how LID practices influence water quantity, nutrient removal, and aquatic ecosystems at watershed scales, particularly in mixed land cover and land use systems. We use the Visualizing Ecosystem Land Management Assessments (VELMA) model to evaluate the effects of different LID practices on daily and long-term watershed-scale hydrology, including infiltration surface runoff. We focus on Shayler Crossing (SHC) watershed, a mixed land cover (61% urban, 24% agriculture, 15% forest) subwatershed of the East Fork Little Miami River watershed, Ohio, United States, with a drainage area of 0.94 km2. The model was calibrated to daily stream flow at the outlet of SHC watershed from 2009 to 2010 and was applied to evaluate diverse distributions (at 25% to 100% implementation levels) and types (e.g., pervious pavement and rain gardens) of LID across the watershed. Results show reduced surface water runoff and higher rates of infiltration concomitant with increasing LID implementation levels; however, this response varies between different LID practices. The highest magnitude response in streamflow at the watershed outlet is evident when a combination of LID practices is applied. The combined scenarios elucidate that the diverse watershed-scale hydrological responses of LID practices depend primarily on the type and extent of the implemented

  7. The income-pollution relationship and the role of income distribution: An analysis of Swedish household data

    Energy Technology Data Exchange (ETDEWEB)

    Braennlund, Runar [Department of Economics, Umeaa University, S-901 87 Umeaa (Sweden); Department of Forest Economics, Swedish University of Agricultural Sciences, S-901 83 Umeaa (Sweden); Ghalwash, Tarek [Department of Economics, Umeaa University, S-901 87 Umeaa (Sweden)

    2008-08-15

    The main purpose of this study is to analyze the relationship between pollution and income at household level. The study is motivated by the recent literature emphasizing the importance of income distribution for the aggregate relation between pollution and income. The main findings from previous studies are that if the individual pollution-income relationship is non-linear, then aggregate pollution for, say, a whole country, will depend not only on average income, but also on how income is distributed. To achieve our objective we formulate a model for determining the choice of consumption of goods in different types of household. Furthermore we link the demand model to emission functions for various goods. The theoretical analysis shows that without imposing very restrictive assumptions on preferences and the emission functions, it is not possible to determine a priori the slope or the curvature of the pollution-income relation. The empirical analysis shows that, given the model used, the pollution-income relation has a positive slope in Sweden and is strictly concave for all three pollutants under study (CO{sub 2}, SO{sub 2}, NO{sub x}), at least in the neighbourhood of the observed income for an average household. We also show that altering the prevailing income distribution, holding average income constant, will affect aggregate emissions in the sense that an equalization of incomes will give rise to an increase in emissions. One implication is then that the development of aggregate pollution due to growth depends not only on the income level, but also on how growth is distributed. (author)

  8. ROLE OF WATERSHED SUBDIVISION ON MODELING THE EFFECTIVENESS OF BEST MANAGEMENT PRACTICES WITH SWAT

    Science.gov (United States)

    Distributed parameter watershed models are often used for evaluating the effectiveness of various best management practices (BMPs). Streamflow, sediment, and nutrient yield predictions of a watershed model can be affected by spatial resolution as dictated by watershed subdivisio...

  9. Watershed management in Myanmar

    International Nuclear Information System (INIS)

    Choi, K.S.

    1993-01-01

    Watershed degradation, watershed management, background of watershed management in Myanmar (condition of watershed, manpower), discussion and recommendation (proposed administrative structure, the need for watershed survey and planning, bottom-up approach) are emphasized. Watershed management, after all can be seen that it is the interphase between the forest, agriculture, soil, wildlife and the local communities

  10. Watershed management in Myanmar

    Energy Technology Data Exchange (ETDEWEB)

    Choi, K S

    1993-10-01

    Watershed degradation, watershed management, background of watershed management in Myanmar (condition of watershed, manpower), discussion and recommendation (proposed administrative structure, the need for watershed survey and planning, bottom-up approach) are emphasized. Watershed management, after all can be seen that it is the interphase between the forest, agriculture, soil, wildlife and the local communities

  11. Transformation of nitrogen and distribution of nitrogen-related bacteria in a polluted urban stream.

    Science.gov (United States)

    Jiao, Y; Jin, W B; Zhao, Q L; Zhang, G D; Yan, Y; Wan, J

    2009-01-01

    Most researchers focused on either nitrogen species or microbial community for polluted urban stream while ignoring the interaction between them and its effect on nitrogen transformation, which restricted the rational selection of an effective and feasible remediation technology. Taking Buji stream in Shenzhen (China) as target stream, the distribution of nitrogen-related bacteria was investigated by most probable number (MPN) besides analysis of nitrogen species etc. The nitrogen-related bacteria in sediment were 10(2) times richer than those in water. Owing to their faster growth, the MPN of ammonifying bacteria and denitrifying bacteria were 10(5) and 10(2) times higher than those of nitrifying bacteria, respectively. The ammonifying bacteria numbers were significantly related to BOD5 in water, while nitrifying bacteria in sediment correlated well with nitrate in water. Thus, nitrification occurred mainly in sediment surface and was limited by low proportion of nitrifying bacteria. The denitrifying bacteria in sediment had good relationship with BOD5 and nitrite and nitrate in water. Low DO and rich organic compounds were beneficial to denitrification but unfavourable to nitrification. Denitrification was restricted by low nitrite and nitrate concentration. These results could be served as a reference for implementing the remediation scheme of nitrogen polluted urban stream.

  12. Distributed In-Line Analysis of Water Pollution in a Spanish Lake

    Directory of Open Access Journals (Sweden)

    Juan V. Capella

    2012-01-01

    Full Text Available This paper presents the architecture and implementation of a set of novel sensor nodes designed to measure ammonium, nitrate and chloride in real time, sending the data, by means of a network, to the base station in order to control the pollution in a lake. The results obtained being compared with those provided by the corresponding reference methods. Recovery analyses with ion selective electrodes and standard methods, study of interferences, and evaluation of major sensor features have also been carried out. The use of a wireless system for monitoring purposes will not only reduce the overall monitoring system cost in term of facilities setup and labor cost, but will also provide flexibility in terms of distance. The major advantages of the proposed in-line analysis compared with the classical off-line procedures are the elimination of contaminants due to sample handling, the minimization of the overall cost of data acquisition, the possibility of real-time analysis, allowing the rapid detection of pollutants, the ability to obtain detailed spatial and temporal data sets of complete environments, obtaining the spatial distribution of the analyzed parameters, as well as its variation with the passing of time, and finally the possibility of performing measurements in locations which are difficult to access (in this case a deep lake.

  13. Distribution and significance of trace element pollutants in hair of the Iraqi population

    International Nuclear Information System (INIS)

    Al-Shahristani, H.; Shihab, K.M.; Jalil, M.

    1979-01-01

    Hair is an excellent indicator of man's exposure to trace element environmental pollutants. Several hundred human head-hair samples were randomly collected from various regions of Iraq representing the general population. These were analysed by thermal neutron activation analysis and the following elements were instrumentally determined: Cr, Fe, Co, Ni, Zn, As, Se, Br, Ag, Cd, Sb, La, Au, Hg, Th and U. The average concentrations of these elements and the frequency distributions among the population are given and compared with concentrations from other regions of the world. Except for Br, the elemental concentrations determined for this population are, in general, similar to those reported for other areas. The low consumption of sea foods in Iraq is perhaps the cause of this anomaly. For certain population groups, high levels of Hg, Au, Cr and Se have been measured and the causes are discussed. In certain cases when exposure to a pollutant has taken place, it is shown that the biological half-life of the element in man can be determined by following the concentration variation along the hair strand. The ratio of the concentration in hair to the average body concentration as well as the total body-burden of the element are also determined from these curves. For methylmercury, the average biological half-life in man was found to be 72 days and the ratio of concentration in hair to average body concentration to be 137. (author)

  14. Field Assessment and Groundwater Modeling of Pesticide Distribution in the Faga`alu Watershed in Tutuila, American Samoa

    Science.gov (United States)

    Welch, E.; Dulai, H.; El-Kadi, A. I.; Shuler, C. K.

    2017-12-01

    To examine contaminant transport paths, groundwater and surface water interactions were investigated as a vector of pesticide migration on the island Tutuila in American Samoa. During a field campaign in summer 2016, water from wells, springs, and streams was collected across the island to analyze for selected pesticides. In addition, a detailed watershed-study, involving sampling along the mountain to ocean gradient was conducted in Faga`alu, a U.S. Coral Reef Task Force priority watershed that drains into the Pago Pago Harbor. Samples were screened at the University of Hawai`i for multiple agricultural chemicals using the ELISA method. The pesticides analyzed include glyphosate, azoxystrobin, imidacloprid and DDT/DDE. Field data was integrated into a MODFLOW-based groundwater model of the Faga`alu watershed to reconstruct flow paths, solute concentrations, and dispersion of the analytes. In combination with land-use maps, these tools were used to identify potential pesticide sources and their contaminant contributions. Across the island, pesticide concentrations were well below EPA regulated limits and azoxystrobin was absent. Glyphosate had detectable amounts in 56% of collected groundwater and 62% of collected stream samples. Respectively, 72% and 36% had imidacloprid detected and 98% and 97% had DDT/DDE detected. The highest observed concentration of glyphosate was 0.3 ppb, of imidacloprid was 0.17 ppb, and of DDT was 3.7 ppb. The persistence and ubiquity of DDT/DDE in surface and groundwater since its last island-wide application decades ago is notable. Groundwater flow paths modeled by MODFLOW imply that glyphosate sources match documented agricultural land-use areas. Groundwater-derived pesticide fluxes to the reef in Faga`alu are 977 mg/d of glyphosate and 1642 mg/d of DDT/DDE. Our study shows that pesticides are transported not only via surface runoff, but also via groundwater through the stream's base flow and are exiting the aquifer via submarine

  15. Lidar Investigation of Aerosol Pollution Distribution near a Coal Power Plant

    Science.gov (United States)

    Mitsev, TS.; Kolarov, G.

    1992-01-01

    Using aerosol lidars with high spatial and temporal resolution with the possibility of real-time data interpretation can solve a large number of ecological problems related to the aerosol-field distribution and variation and the structure of convective flows. Significantly less expensive specialized lidars are used in studying anthropogenic aerosols in the planetary boundary layer. Here, we present results of lidar measurements of the mass-concentration field around a coal-fired power plant with intensive local aerosol sources. We studied the pollution evolution as a function of the emission dynamics and the presence of retaining layers. The technique used incorporates complex analysis of three types of lidar mapping: horizontal map of the aerosol field, vertical cross-section map, and a series of profiles along a selected path. The lidar-sounding cycle was performed for the time of atmosphere's quasi-stationarity.

  16. Lidar investigation of aerosol pollution distribution near a coal power plant

    International Nuclear Information System (INIS)

    Mitsev, T.S.; Kolarov, G.

    1992-01-01

    Using aerosol lidars with high spatial and temporal resolution with the possibility of real-time data interpretation can solve a large number of ecological problems related to the aerosol-field distribution and variation and the structure of convective flows. Significantly less expensive specialized lidars are used in studying anthropogenic aerosols in the planetary boundary layer. Here, results are presented of lidar measurements of the mass-concentration field around a coal-fired power plant with intensive local aerosol sources. The authors studied the pollution evolution as a function of the emission dynamics and the presence of retaining layers. The technique used incorporates complex analysis of three types of lidar mapping: horizontal map of the aerosol field, vertical cross-section map, and a series of profiles along a selected path. The lidar-sounding cycle was performed for the time of atmosphere's quasi-stationarity

  17. Spatial distribution and pollution evaluation of heavy metals in Yangtze estuary sediment.

    Science.gov (United States)

    Liu, Ruimin; Men, Cong; Liu, Yongyan; Yu, Wenwen; Xu, Fei; Shen, Zhenyao

    2016-09-15

    To analyze the spatial distribution patterns and ecological risks of heavy metals, 30 sediment samples were taken in the Yangtze River Estuary (YRE) in May 2011. The content of Al, As, Cr, Cu, Fe, Mn, Ni and Pb increased as follows: inner-regionpollutants. What is more, the greatest contaminated area appeared at the river mouth of the south branch of YRE. In Tucker 3, considering the fractions of metals, Mn turned to be the severest pollutant and As did not contribute too much to the contamination of the YRE. That was most probably because that Mn was closely related to the carbonate-associated (CARB) and As was related to organic-associated (OM) which is more stable than CARB. The fractions played an important role in the contamination assessment of heavy metals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Relationships between past and present pesticide applications and pollution at a watershed outlet: The case of a horticultural catchment in Martinique, French West Indies.

    Science.gov (United States)

    Mottes, Charles; Lesueur Jannoyer, Magalie; Le Bail, Marianne; Guéné, Mathilde; Carles, Céline; Malézieux, Eric

    2017-10-01

    The understanding of factors affecting pesticide transfers to catchment outlet is still at a very early stage in tropical context, and especially on tropical volcanic context. We performed on-farm pesticide use surveys during 87 weeks and monitored pesticides in water weekly during 67 weeks at the outlet of a small catchment in Martinique. We identified three types of pollution. First, we showed long-term chronic pollution by chlordecone, diuron and metolachlor resulting from horticultural practices applied 5-20 years ago (quantification frequency higher than 80%). Second, we showed peak pollution. High amounts of propiconazole and fosthiazate applied at low frequencies caused river pollution peaks for weeks following a single application. Low amounts of diquat and diazinon applied at low frequencies also caused pollution peaks. The high amounts of glyphosate applied at high frequency resulted into pollution peaks by glyphosate and aminomethylphosphonic acid (AMPA) in 6 and 20% of the weeks. Any intensification of their uses will result in higher pollution levels. Third, relatively low amounts of glufosinate-ammonium, difenoconazol, spinosad and metaldehyde were applied at high frequencies. Unexpectedly, such pesticides remained barely detected (pollution of shallow aquifers alimenting surface water. We prove that to avoid the past errors and decrease the risk of long-term pollution of water resources, it is urgent to reduce or stop the use of pesticides with leaching potential by changing agricultural practices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Spatial distribution and pollution assessment of heavy metals in urban soils from southwest China

    Institute of Scientific and Technical Information of China (English)

    Guanghui Guo; FengchangWu; Fazhi Xie; Ruiqing Zhang

    2012-01-01

    To identify the concentrations and sources of heavy metals,and to assess soil environmental quality,63 soil samples were collected in Yibin City,Sichuan Province,China.Mean concentrations of As,Pb,Zn,and Cu were 10.55,61.23,138.88 and 56.35 mg/kg,respectively.As concentrations were comparable to background values,while Pb,Zn,and Cu concentrations were higher than their corresponding background values.Industrial areas exhibited the highest concentrations of As,Pb,Zn,and Cu,while the lowest concentrations occurred in parks.Statistical analysis was performed and two cluster groups of metals were identified with Pb,Zn,and Cu in one group and As in the other.Spatial distribution maps indicated that Pb,Zn,and Cu were mainly controlled by anthropogenic activities,whereas As could be mainly accounted for by soil parent materials.Pollution index values of As,Pb,Zn,and Cu varied in the range of 0.24-1.93,0.66-7.24,0.42-4.19,and 0.62-5.25,with mean values of 0.86,1.98,1.61,and 1.78,respectively.The integrated pollution index(IPI)values of these metals varied from 0.82 to 3.54,with a mean of 1.6 and more than 90% of soil samples were moderately or highly contaminated with heavy metals.The spatial distribution of IPI showed that newer urban areas displayed relatively lower heavy metal contamination in comparison with older urban areas.

  20. [Accumulation, distribution and pollution assessment of heavy metals in surface sediment of Caohai plateau wetland, Guizhou province].

    Science.gov (United States)

    Zhang, Qing-Hai; Lin, Chang-Hu; Tan, Hong; Lin, Shao-Xia; Yang, Hong-Bo

    2013-03-01

    The objective of this paper is to investigate the concentrations and distribution characteristics of heavy metals in surface sediments of different areas in the Caohai plateau wetland. 16 samples of surface sediments were collected and 7 heavy metals were analyzed. Heavy metal pollution in surface sediments of different areas in the Caohai plateau wetland was estimated by the Tomlinson Pollution Load Index (PLI) method. The analyzed results indicated that the average contents of Cd, Hg, As, Pb, Cr, Cu, Zn were 0.985, 0.345, 15.8, 38.9, 38.6, 22.8 and 384 mg x kg(-1), respectively. The heavy metal distributions varied with regional environment changes, the order of average contents of Cd and Hg in different regions was E (the eastern region) > S (the southern region) > N (the northern region), the order of the average content of Pb was N > E > S, and that of Zn was S > E > N. The results also suggested a medium heavy metal pollution level in the surface sediment of the Caohai plateau wetland with the PLI(zone) reaching 1.17. The order of pollution level in surface sediments of different regions was E > S > N. The results showed medium pollution levels in E and Hg which reached the extreme intensity pollution level were also the major polluted elements in surface sediments of the Caohai plateau wetland. And also, results showed medium pollution levels of Cd and Pb in surface sediments of Caohai plateau wetland. Cluster analysis results showed similar pollution sources of Cd, Zn, Pb and Hg, which should be attached great importance in terms of the prevention of the Caohai plateau wetland.

  1. Spatial Distribution of 137Cs in Suface Soil under Different Land Uses in Chao Phraya Watershed: Potential Used as Sediment source Tracing

    International Nuclear Information System (INIS)

    Srisuksawad, K.; Porntepkasemsan, B.; Noipow, N.; Omanee, A.; Wiriyakitnateekul, W.; Choybudha, R.; Srimawong, P.

    2014-01-01

    Sediment fingerprinting techniques involves the discrimination of sediment sources based on differences in source material properties and quantification of the relative contributions from these sources to sediment delivered downstream to the river catchments. Results of the previous study indicated that fallout radionuclides (FRNs); 137 Cs and excess 210 Pb ( 210 Pbex) are the most suitable radionuclides to be used as sediments sources tracers. This study investigated the spatial distribution of 137 Cs in soil under different land uses in Chao Phraya watershed, the most significant watershed in Thailand. Emphasis was placed on discriminating among potential sediment sources include the cultivated (upland crops), pasture field, uncultivated (swamp, forest, and grass field), and channel erosion (stream and river bank). One hundred and twenty four soil samples were collected from all sources and determining for 137 Cs. The 137 Cs mass activities in pasture areas varied from the limit of detection (LLD) to 1.22±0.05 with the average of 0.64±0.14 Bq kg -1 . In cultivated areas the 137 Cs mass activities varied from LLD to 1.41±0.04 with the average of 0.38±0.04 Bq kg -1 .The 137 Cs mass activities were higher in uncultivated areas varied from 0.12± 0.03 to 1.73 ±0.05 with the average of 0.76±0.15 Bq kg -1 . The 137 Cs mass activities in channel bank varied from LLD to 1.16±0.04 with the average of 0.39±0.05 Bq kg -1 .GIS and geospatial interpolations revealed pattern in the spatial concentrations of 137 Cs and indicated important differences in its distributions showing the differences behavior of 137 Cs in different land uses.

  2. Risk Assessment of Nitrogen and Phosphorus Loss in a Hilly-Plain Watershed Based on the Different Hydrological Period: A Case Study in Tiaoxi Watershed

    Directory of Open Access Journals (Sweden)

    Hongmeng Ye

    2017-08-01

    Full Text Available Non-point source pollution is widely considered a serious threat to drinking water. Eutrophication in Chinese watershed is mainly due to nitrogen and phosphorus output from agricultural source. Taihu Lake is a typical eutrophic lake in China, a basin representative for the study of the temporal-spatial characteristics of pollution loading of nitrogen and phosphorus to provide scientific basis for reasonable estimation and targeted control measures of nitrogen and phosphorus loss. Based on data from nitrogen and phosphorus loss in agricultural land, livestock breeding, domestic discharge and aquaculture, this study calculated the levels of nitrogen and phosphorus comprehensive loss risk for each pollution source. Using the superposition of ArcGIS raster data, we also described the spatial distribution of nitrogen and phosphorus comprehensive loss risk by the formula of comprehensive loss risk. The results showed that critical risk areas of nitrogen and phosphorus loss mainly originated from livestock breeding and agricultural land during flood period in Tiaoxi watershed. Agricultural land and livestock breeding sources formed major parts of nitrogen loss, accounting for 30.85% and 36.18%, respectively, while phosphorus loss mainly originated from livestock breeding (56.28%. During non-flood period, integrated management of livestock breeding and domestic discharge requires much attention to control nitrogen and phosphorus loss in the critical risk area. Finally, it is of great practical significance to propose spatial-temporal targeted measurements to control nitrogen and phosphorus pollution in watershed for various periods and different areas.

  3. Effect of industrial pollution on the distribution dynamics of radionuclides in boreal understorey ecosystems (EPORA). Final report

    International Nuclear Information System (INIS)

    Suomela, M.; Rahola, T.; Bergman, R.; Bunzl, K.; Jaakkola, T.

    1999-08-01

    The project EPORA 'Effects of Industrial Pollution on Distribution Dynamics of Radionuclides in Boreal Understorey Ecosystems' is a part of the Nuclear Fission Safety Research programme of the European Union. A suitable environment for the study was found in the surroundings of the Cu-Ni smelter in Monchegorsk, in NW Russia where the huge atmospheric emissions from the smelter have polluted the environment since the 1930's. Samples of soil, litter, plants and runoff water were taken. Total concentrations of the main pollutants, Ni and Cu, in the organic soil increased from about 10 mg kg -1 at the reference site in Finland to about 5000 mg kg -1 at the most polluted site in Russia. Similar trends were observed for exchangeable fractions and plant concentrations of the same elements. Concentrations of exchangeable K, Ca, and Mg in the organic soil decreased strongly with increased input of chemical pollutants. The radionuclides studied were 137 Cs, 90 Sr and 239+240 Pu, mainly originating from the atmospheric nuclear weapons tests. The contribution of the Chernobyl derived 137 Cs deposition was about 10% but insignificant for the other nuclides. The activity distribution of all three radionuclides in the soil, their corresponding residence half-times as well as their aggregated trencher factors for various plants depended on the degree of pollution: Activity distribution: in the litter layer, the activity of all three radionuclides increased continually from the reference site to the most polluted site. This effect was most pronounced for 239+240 Pu and least for 90 Sr and could, at least partly, be explained by the increase of the thickness of this layer. In the root zone, the opposite effect was observed: the largest fraction of all radionuclides was found at the reference site. In the organic layer, the exchangeable fractions of 137 Cs, 90 Sr and 239+240 Pu decreased with increasing pollution. Residence half-times: in the root zone, the residence half-times of 90

  4. IOC-UNEP review meeting on oceanographic processes of transport and distribution of pollutants in the sea

    International Nuclear Information System (INIS)

    1991-01-01

    The IOC-UNEP Review Meeting on Oceanographic Processes of Transfer and Distribution of Pollutants in the Sea was opened at the Ruder Boskovic Institute, Zagreb, Yugoslavia on Monday, 15 May 1989. Papers presented at the meeting dealt with physical and geochemical processes in sea-water and sediment in transport mixing and dispersal of pollutants. The importance of mesoscale eddies and gyres in the open sea, wind-driven currents and upwelling events in the coastal zone, and thermohaline processes in semi-enclosed bays and estuaries was recognized. There is strong evidence that non-local forcing can drive circulation in the coastal area. Concentrations, horizontal and vertical distributions and transport of pollutants were investigated and presented for a number of coastal areas. Riverine and atmospheric inputs of different pollutants to the western Mediterranean were discussed. Reports on two on-going nationally/internationally co-ordinated projects (MEDMODEL, EROS 2000) were presented. Discussions during the meeting enabled an exchange of ideas between specialists in different disciplines to be made. It is expected that this will promote the future interdisciplinary approach in this field. The meeting recognized the importance of physical oceanographic studies in investigating the transfer and distribution of pollutants in the sea and in view of the importance of the interdisciplinary approach and bilateral and/or multilateral co-operation a number of recommendations were adopted

  5. Effect of pollution on the distribution of chaetognaths in the nearshore waters of Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Nair; Gajbhiye, S.N.; Desai, B.N.

    polluted with sewage. Incidence of chaetognaths at sewage polluted areas was limited mostly to periods of high tide; with population density much less (max 10.m super(-3)) than that of areas free of pollution (max 40.m super(-3)). Sagitta bedoti...

  6. From Polluter Pays to Provider Gets: Distribution of Rights and Costs under Payments for Ecosystem Services

    Directory of Open Access Journals (Sweden)

    Volker Mauerhofer

    2013-12-01

    Full Text Available Should society have the right to freely available clean air and water, or should people be required to pay for these as commodities just as they do for many other goods or services that they consume? With this question and further questions on environmental governance in mind, we reviewed the paradigm shift in natural resource management from the polluter pays principle (PPP, which focuses on polluters and enforcement of thresholds, to the principle of payments for ecosystem services (PES, which emphasizes provider-based economic approaches. Given that there are conflicts of interest over natural resources and ecosystem services (ESs, these conflicts could be resolved through rights and/or cost assignments via third-party intervention, i.e., by the "state," or through private compensation beyond initial regulation and state-initiated assignments of cost. Our analysis includes an in-depth literature review and a description of existing policies on ESs. We also examine the so-called Coase theorem based on a "neutral" situation where no rights or costs are distributed in advance. This theorem provides room for the PPP approaches and the provider-gets approaches. Both of these approaches should ensure, given certain assumptions, an economically efficient allocation of resources; however, they still ignore two indispensable issues, namely, the ecologically sustainable scale and inherent qualities of ecosystems and the distributional effects. With regard to the relationship between these two sets of approaches and their respective relationship to the legal framework, PES programs can evolve instead of PPP where no regulations are in place, existing regulations are deemed to be insufficiently formulated, or regulations are not enforced at all. We also further address some critical issues that can arise when PES programs evolve instead of PPP in practice, such as the general necessity of PES to coexist with basic rights and legal obligations

  7. 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.

  8. Node-to-node field calibration of wireless distributed air pollution sensor network.

    Science.gov (United States)

    Kizel, Fadi; Etzion, Yael; Shafran-Nathan, Rakefet; Levy, Ilan; Fishbain, Barak; Bartonova, Alena; Broday, David M

    2018-02-01

    Low-cost air quality sensors offer high-resolution spatiotemporal measurements that can be used for air resources management and exposure estimation. Yet, such sensors require frequent calibration to provide reliable data, since even after a laboratory calibration they might not report correct values when they are deployed in the field, due to interference with other pollutants, as a result of sensitivity to environmental conditions and due to sensor aging and drift. Field calibration has been suggested as a means for overcoming these limitations, with the common strategy involving periodical collocations of the sensors at an air quality monitoring station. However, the cost and complexity involved in relocating numerous sensor nodes back and forth, and the loss of data during the repeated calibration periods make this strategy inefficient. This work examines an alternative approach, a node-to-node (N2N) calibration, where only one sensor in each chain is directly calibrated against the reference measurements and the rest of the sensors are calibrated sequentially one against the other while they are deployed and collocated in pairs. The calibration can be performed multiple times as a routine procedure. This procedure minimizes the total number of sensor relocations, and enables calibration while simultaneously collecting data at the deployment sites. We studied N2N chain calibration and the propagation of the calibration error analytically, computationally and experimentally. The in-situ N2N calibration is shown to be generic and applicable for different pollutants, sensing technologies, sensor platforms, chain lengths, and sensor order within the chain. In particular, we show that chain calibration of three nodes, each calibrated for a week, propagate calibration errors that are similar to those found in direct field calibration. Hence, N2N calibration is shown to be suitable for calibration of distributed sensor networks. Copyright © 2017 Elsevier Ltd. All

  9. A multimethodological approach to study the spatial distribution of air pollution in an Alpine valley during wintertime

    Directory of Open Access Journals (Sweden)

    R. Schnitzhofer

    2009-05-01

    Full Text Available In order to investigate the spatial distribution of air pollutants in the Inn valley (Tyrol, Austria during wintertime, a joint field campaign of the three research projects ALPNAP (Monitoring and Minimisation of Traffic-Induced Noise and Air Pollution Along Major Alpine Transport Routes, INNAP (Boundary Layer Structure in the Inn Valley during high Air Pollution and INNOX (NOx-structure in the Inn Valley during High Air Pollution was carried out in January/February 2006. In addition to continuous ground based measurements, vertical profiles of various air pollutants and meteorological parameters were obtained on six selected days. For in-situ investigations, a tethered balloon was used to analyse the lowest atmospheric layers, 0–500 m above the valley bottom (a.v.b., and a research aircraft sampled at 150–2200 m a.v.b. An aircraft equipped with an aerosol backscatter lidar performed nadir measurements at 3000 m a.v.b. Combined results from a typical day show a strongly polluted layer up to about 125 m a.v.b. in the morning. Around midday concentrations on the valley floor decrease indicating some vertical air exchange despite thermally stable conditions. Strong vertical and horizontal gradients with enhanced pollution levels along the sunny side of the valley up to 1300 m a.v.b. were observed in the afternoon. This vertical mixing due to thermally or dynamically driven slope winds reduces the concentration of air pollutants at the bottom of the valley and causes the formation of elevated pollution layers.

  10. Venous thromboembolism in an industrial north american city: temporal distribution and association with particulate matter air pollution.

    Directory of Open Access Journals (Sweden)

    Holly H Chiu

    Full Text Available BACKGROUND: Emerging evidence, mainly from Europe and Asia, indicates that venous thromboembolism (VTE occurs most often in winter. Factors implicated in such seasonality are low temperature-mediated exacerbation of coagulation and high levels of particulate matter (PM air pollution. However, in contrast to most European and Asian cities, particulate matter pollution peaks in the summer in many North American cities. OBJECTIVES: We aimed to exploit this geographical difference and examine the temporal distribution of VTE in a cold-weather, North American city, Detroit, with a summer PM peak. Our goal was thereby to resolve the influence of temperature and PM levels on VTE. METHODS: Our retrospective, analytical semi-ecological study used chart review to confirm 1,907 acute, ambulatory VTE cases, divided them by location (Detroit versus suburban, and plotted monthly VTE frequency distributions. We used Environmental Protection Agency data to determine the temporal distribution of PM pollution components in Detroit. Suburban PM air pollution is presumed negligible and therefore not monitored. RESULTS: Acute VTE cases in Detroit (1,490 exhibited a summer peak (June 24(th and differed from both a uniform distribution (P<0.01 and also that of 1,123 no-VTE cases (P<0.02. Levels of 10 µm diameter PM and coarse particle (2.5 to 10 µm PM also exhibited summer peaks versus a winter peak for 2.5 µm diameter PM. Contrary to their urban counterparts, suburban cases of acute VTE (417 showed no monthly variation. CONCLUSIONS: The summer peak of acute VTE in Detroit indicates that low temperature is not a major factor in VTE pathogenesis. In contrast, concordance of the 10 µm diameter PM, coarse particle, and the Detroit VTE monthly distributions, combined with no monthly suburban VTE variation, is consistent with a role for PM pollution. Furthermore, divergence of the VTE and 2.5 µm PM distributions suggests that particle size may play a role.

  11. Co-occurrence and genotypic distribution of Phytophthora species recovered from watersheds and plant nurseries of eastern Tennessee.

    Science.gov (United States)

    Hulvey, Jon; Gobena, Daniel; Finley, Ledare; Lamour, Kurt

    2010-01-01

    In 2008 statewide surveys of symptomatic foliage of nursery plants from Tennessee resulted in isolation of 43 isolates of Phytophthora spp. This sample set includes four described species (P. citrophthora, P. citricola, P. nicotianae, P. syringae), and a provisional species of Phytophthora ('P. hydropathica'). At the same time a stream-baiting survey was initiated to recover Phytophthora from eight watersheds in eastern Tennessee, some of which are near plant nurseries. Baiting was accomplished by submerging healthy Rhododendron leaves approximately 1 wk and isolation onto selective media. Six baiting periods were completed, and in total 98 Phytophthora isolates and 45 isolates of Pythium spp. were recovered. Three described species (P. citrophthora, P. citricola and P. irrigata) and the provisional species 'P. hydropathica' were obtained as well as three undescribed Phytophthora taxa and Pythium litorale. Isolates from both surveys were identified to species with morphology and the internal transcribed spacer (ITS) sequence. Isolates from species co-occurring in streams and nurseries (P. citricola, P. citrophthora and 'P. hydropathica') were characterized further with amplified fragment length polymorphism (AFLP) analyses and mefenoxam tolerance assays. Isolates representing a putative clonal genotype of P. citricola were obtained from both environmental and nursery sample sets.

  12. Distribution of Total and Organic Mercury in Superficial Soils in the Upper Manzanares River Watershed, Sucre State, Venezuela

    Directory of Open Access Journals (Sweden)

    Yahsé Rojas Challa

    2008-01-01

    Full Text Available Total and organic mercury contents were determined from samples of surface soils (0-5 cm, sieved at ≤ 63µm, collected from 10 different locations in the upper Manzanares River watershed, using cold vapor atomic absorption spectroscopy. Methylmercury was determined using a HPLC-UV detector. The mean total mercury concentration was 1.3 μg.g-1, a value permitted by the Canadian environment quality guidelines for farming soils, but high for European standards. Using certified reference materials, we verified that a modification of the method described by Qian et al. (2000 was effective for organic mercury extraction, with a recovery of 92.17% for DORM-2 and 92.11% for TORT-2. This modified method was applied to soil samples, obtaining concentrations of 0.5-1.0 μg.g-1 of organic mercury. The parameters for determining methylmercury using HPLC-UV were optimized; the best results were obtained with a 4.6 mm x 25 cm Zorbax CN column, with a mobile phase of 70/30 V/V of methanol: ammonium acetate 0.05 mol.l-1, with a flow rate of 0.5 ml.min-1; the methylmercury was detected at 4.99 min retention time. Methylmercury was not found in the soil samples. Using the certified reference material we proved that the method used produced reliable results. The analysis confirmed the existence of mercury in this farming area.

  13. The distribution of phosphorus in Popes Creek, VA, and in the Pocomoke River, MD: Two watersheds with different land management practices in the Chesapeake Bay Basin

    Science.gov (United States)

    Simon, N.S.; Bricker, O.P.; Newell, W.; McCoy, J.; Morawe, R.

    2005-01-01

    This paper compares phosphorus (P) concentrations in sediments from two watersheds, one with, and one without, intensive animal agriculture. The watersheds are in the coastal plain of the Chesapeake Bay and have similar physiographic characteristics. Agriculture in the Pocomoke River, MD, watershed supplied 2.7 percent of all broiler chickens produced in the USA in 1997. Poultry litter is an abundant, local source of manure for crops. Broiler chickens are not produced in the Popes Creek, VA, watershed and poultry manure is, therefore, not a major source of fertilizer. The largest concentrations of P in sediment samples are found in floodplain and main-stem bottom sediment in both watersheds. Concentrations of total P and P extracted with 1N HCl are significantly larger in main-stem bottom sediments from the Pocomoke River than in main-stem bottom sediments from Popes Creek. Larger concentrations of P are associated with what are potentially redox sensitive iron oxyhydroxides in sediment samples from the Pocomoke River watershed than are associated with what are potentially redox sensitive iron oxyhydroxides in sediment samples from the Popes Creek watershed. Data for P and iron (Fe) concentrations in sediments from the Popes Creek watershed provide a numerical framework (baseline) with which to compare P and Fe concentrations in sediment from the Pocomoke River watershed. ?? Springer 2005.

  14. Morphology, chemistry and distribution of neoformed spherulites in agricultural land affected by metallurgical point-source pollution

    NARCIS (Netherlands)

    Leguedois, S.; Oort, van F.; Jongmans, A.G.; Chevalier, P.

    2004-01-01

    Metal distribution patterns in superficial soil horizons of agricultural land affected by metallurgical point-source pollution were studied using optical and electron microscopy, synchrotron radiation and spectroscopy analyses. The site is located in northern France, at the center of a former entry

  15. Watershed restoration through remining in the Tangascootack Creek Watershed, Clinton County, Pennsylvania

    International Nuclear Information System (INIS)

    Skema, V.W.; Smith, M.W.; Bisko, D.C.; Dimatteo, M.

    1998-01-01

    The Pennsylvania Department of Environmental Protection and the Pennsylvania Geologic Survey are working together to remediate the effects of acid mine drainage. Remining of previously mined areas is a key component of a comprehensive strategy of improving water quality in polluted watersheds. In this new approach sites will be carefully selected on the basis of remaining coal reserves and overburden characteristics. One of the first watersheds targeted was the Tangascootack Creek watershed located in Clinton County near Lock Haven. The Geologic Survey agreed to provide geologic and coal resource maps for this previously unmapped area. This involved conducting field work examining rock exposures. Five cored holes were drilled, and core was examined to develop a geologic framework. Coals from these holes and from highwalls were chemically tested. Strata overlying the coal seams were analyzed using acid base accounting to determine their potential for generating acidity as well as alkalinity. Additional drill hole data and chemical analyses were collected from cooperating mining companies. This information was used to produce a geologic map showing coal crop lines and structure, coal thickness maps, mined-out area maps, overburden thickness maps, overburden geochemistry maps, strip ratio maps, and to estimate the extent of remaining coal reserves. Several significant geologic features were found in the course of mapping the watershed. One is the extreme variability in coal thickness and character of overburden rock. Another is the degree of relief found to be present on the Mississippian-Pennsylvanian unconformity. It is believed that this feature plays an important role in coal and high aluminum flint clay distribution regionally. And finally is the thick occurrence of Loyalhanna Formation calcareous sandstone which is providing a natural source of carbonate for the neutralization of acid mine drainage

  16. NOAA's Coral Reef Conservation Program: 2016 projects in priority watersheds to reduce the impacts of land based sources of pollution on corals

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 2016 the following projects will take place to work on understanding and reducing the impacts of land based sources pollution on corals: Input of Sediments and...

  17. Quantifying air distribution, ventilation effectiveness and airborne pollutant transport in an aircraft cabin mockup

    Science.gov (United States)

    Wang, Aijun

    The health, safety and comfort of passengers during flight inspired this research into cabin air quality, which is closely related to its airflow distribution, ventilation effectiveness and airborne pollutant transport. The experimental facility is a full-scale aircraft cabin mockup. A volumetric particle tracking velocimetry (VPTV) technique was enhanced by incorporating a self-developed streak recognition algorithm. Two stable recirculation regions, the reverse flows above the seats and the main air jets from the air supply inlets formed the complicated airflow patterns inside the cabin mockup. The primary air flow was parallel to the passenger rows. The small velocity component in the direction of the cabin depth caused less net air exchange between the passenger rows than that parallel to the passenger rows. Different total air supply rate changed the developing behaviors of the main air jets, leading to different local air distribution patterns. Two indices, Local mean age of air and ventilation effectiveness factor (VEF), were measured at five levels of air supply rate and two levels of heating load. Local mean age of air decreased linearly with an increase in the air supply rate, while the VEF remained consistent when the air supply rate varied. The thermal buoyancy force from the thermal plume generated the upside plume flow, opposite to the main jet flow above the boundary seats and thus lowered the local net air exchange. The airborne transport dynamics depends on the distance between the source and the receptors, the relative location of pollutant source, and air supply rate. Exposure risk was significantly reduced with increased distance between source and receptors. Another possible way to decrease the exposure risk was to position the release source close to the exhaust outlets. Increasing the air supply rate could be an effective solution under some emergency situations. The large volume of data regarding the three-dimensional air velocities was

  18. Global impacts of the meat trade on in-stream organic river pollution: the importance of spatially distributed hydrological conditions

    Science.gov (United States)

    Wen, Yingrong; Schoups, Gerrit; van de Giesen, Nick

    2018-01-01

    In many regions of the world, intensive livestock farming has become a significant source of organic river pollution. As the international meat trade is growing rapidly, the environmental impacts of meat production within one country can occur either domestically or internationally. The goal of this paper is to quantify the impacts of the international meat trade on global organic river pollution at multiple scales (national, regional and gridded). Using the biological oxygen demand (BOD) as an overall indicator of organic river pollution, we compute the spatially distributed organic pollution in global river networks with and without a meat trade, where the without-trade scenario assumes that meat imports are replaced by local production. Our analysis reveals a reduction in the livestock population and production of organic pollutants at the global scale as a result of the international meat trade. However, the actual environmental impact of trade, as quantified by in-stream BOD concentrations, is negative; i.e. we find a slight increase in polluted river segments. More importantly, our results show large spatial variability in local (grid-scale) impacts that do not correlate with local changes in BOD loading, which illustrates: (1) the significance of accounting for the spatial heterogeneity of hydrological processes along river networks, and (2) the limited value of looking at country-level or global averages when estimating the actual impacts of trade on the environment.

  19. Distribution and extent of heavy metal accumulation in Song Sparrows (Melospiza melodia), upper Santa Cruz River watershed, southern Arizona, 2011-12

    Science.gov (United States)

    Lester, Michael B.; van Riper, Charles

    2014-01-01

    Riparian ecosystems in arid environments provide critical habitat for breeding, migratory, and wintering birds, yet are often at risk of contamination by heavy metals. Birds and other animals living in contaminated areas are susceptible to adverse health effects as a result of long-term exposure and bioaccumulation of heavy metals. We investigated the distribution and cascading extent of heavy metal accumulation in Song Sparrows (Melospiza melodia) in Arizona’s upper Santa Cruz River watershed. This study had three goals: (1) quantify the degree of heavy metal accumulation in sparrows and determine the distributional patterns among study sites, (2) compare concentrations of metals found in this study to those found in studies performed prior to the 2009 international wastewater treatment plant upgrade, and (3) assess sparrow condition among sites with differing potential sources of contamination exposure. We examined six study sites that reflected different potential sources of contamination. Hematocrit values, body mass residuals, and leukocyte counts were used to assess sparrow condition. Cadmium, copper, mercury, nickel, and selenium exceeded background concentrations at some sites, but generally were lower than or similar to concentrations found in earlier studies performed prior to the 2009 international wastewater treatment plant upgrade. Concentrations were higher in recaptured birds in 2012 than in 2011 for 7 metals in feathers and 14 metals in blood, suggesting possible bioaccumulation. We found no cascading effects as a result of heavy metal exposure, but did find that heavy metal concentrations were reduced following the 2009 international wastewater treatment plant upgrade.

  20. Preliminary results on the distribution of some pollutants in the Baltic 1980 and 1981

    International Nuclear Information System (INIS)

    Bruegmann, L.; Rohde, K.H.

    1981-01-01

    In September/October 1980 complex field studies on the distribution of heavy metals, petroleum hydrocarbons, chlorinated hydrocarbon and radionuclides were carried out on 24 stations in the Baltic Sea. Samples of different compartments of the marine environment were taken. The analyses for some heavy metals in water were performed directly on board. First results including mean values and concentration ranges for Hg, Cd, Pb, Cu, Zn, Sr-90 and Cs-137 in Baltic waters and for petroleum hydrocarbons, PCBs, DDT metabolites, HCB, α-HCH and γ-HCH in water and surface film samples are given. In most cases the data confirm recently published results. Relatively low concentrations were found for mercury. The investigations were repeated in May/June 1981 covering the Baltic Sea and parts of the North Atlantic. The resultant data for heavy metals and petroleum hydrocarbons agree widely with the results from 1980. An estimation of the relative pollutant burden of the Baltic Sea related to the investigated parts of the North Atlantic is given. (author)

  1. Air Pollution Distribution Patterns in the San Bernardino Mountains of Southern California: a 40-Year Perspective

    Directory of Open Access Journals (Sweden)

    Andrzej Bytnerowicz

    2007-01-01

    Full Text Available Since the mid-1950s, native pines in the San Bernardino Mountains (SBM in southern California have shown symptoms of decline. Initial studies in 1963 showed that ozone (O3 generated in the upwind Los Angeles Basin was responsible for the injury and decline of sensitive trees. Ambient O3 decreased significantly by the mid-1990s, resulting in decreased O3 injury and improved tree growth. Increased growth of trees may also be attributed to elevated atmospheric nitrogen (N deposition. Since most of the N deposition to mixed conifer forest stands in the SBM results from dry deposition of nitric acid vapor (HNO3 and ammonia (NH3, characterization of spatial and temporal distribution of these two pollutants has become essential. Although maximum daytime O3 concentrations over last 40 years have significantly decreased (~3-fold, seasonal means have been reduced much less (~1.5-fold, with 2-week long means occasionally exceeding 100 ppb in the western part of the range. In the same area, significantly elevated concentrations of HNO3 and NH3, up to 17.5 and 18.5 μg/m3 as 2-week averages, respectively, have been determined. Elevated levels of O3 and increased N deposition together with long-term drought predispose the SBM forests to massive bark beetle attacks making them susceptible to catastrophic fires.

  2. A Random Forest approach to predict the spatial distribution of sediment pollution in an estuarine system.

    Directory of Open Access Journals (Sweden)

    Eric S Walsh

    Full Text Available Modeling the magnitude and distribution of sediment-bound pollutants in estuaries is often limited by incomplete knowledge of the site and inadequate sample density. To address these modeling limitations, a decision-support tool framework was conceived that predicts sediment contamination from the sub-estuary to broader estuary extent. For this study, a Random Forest (RF model was implemented to predict the distribution of a model contaminant, triclosan (5-chloro-2-(2,4-dichlorophenoxyphenol (TCS, in Narragansett Bay, Rhode Island, USA. TCS is an unregulated contaminant used in many personal care products. The RF explanatory variables were associated with TCS transport and fate (proxies and direct and indirect environmental entry. The continuous RF TCS concentration predictions were discretized into three levels of contamination (low, medium, and high for three different quantile thresholds. The RF model explained 63% of the variance with a minimum number of variables. Total organic carbon (TOC (transport and fate proxy was a strong predictor of TCS contamination causing a mean squared error increase of 59% when compared to permutations of randomized values of TOC. Additionally, combined sewer overflow discharge (environmental entry and sand (transport and fate proxy were strong predictors. The discretization models identified a TCS area of greatest concern in the northern reach of Narragansett Bay (Providence River sub-estuary, which was validated with independent test samples. This decision-support tool performed well at the sub-estuary extent and provided the means to identify areas of concern and prioritize bay-wide sampling.

  3. Distribution and Modeled Transport of Plastic Pollution in the Great Lakes, the World's Largest Freshwater Resource

    Directory of Open Access Journals (Sweden)

    Rachel N. Cable

    2017-07-01

    Full Text Available Most plastic pollution originates on land. As such, freshwater bodies serve as conduits for the transport of plastic litter to the ocean. Understanding the concentrations and fluxes of plastic litter in freshwater ecosystems is critical to our understanding of the global plastic litter budget and underpins the success of future management strategies. We conducted a replicated field survey of surface plastic concentrations in four lakes in the North American Great Lakes system, the largest contiguous freshwater system on the planet. We then modeled plastic transport to resolve spatial and temporal variability of plastic distribution in one of the Great Lakes, Lake Erie. Triplicate surface samples were collected at 38 stations in mid-summer of 2014. Plastic particles >106 μm in size were quantified. Concentrations were highest near populated urban areas and their water infrastructure. In the highest concentration trawl, nearly 2 million fragments km−2 were found in the Detroit River—dwarfing previous reports of Great Lakes plastic abundances by over 4-fold. Yet, the accuracy of single trawl counts was challenged: within-station plastic abundances varied 0- to 3-fold between replicate trawls. In the smallest size class (106–1,000 μm, false positive rates of 12–24% were determined analytically for plastic vs. non-plastic, while false negative rates averaged ~18%. Though predicted to form in summer by the existing Lake Erie circulation model, our transport model did not predict a permanent surface “Lake Erie Garbage Patch” in its central basin—a trend supported by field survey data. Rather, general eastward transport with recirculation in the major basins was predicted. Further, modeled plastic residence times were drastically influenced by plastic buoyancy. Neutrally buoyant plastics—those with the same density as the ambient water—were flushed several times slower than plastics floating at the water's surface and exceeded the

  4. Contributions of GRACE to Understanding of Spatial Distribution of Spring Flooding in Snow-dominated Afghan Watersheds

    Science.gov (United States)

    Roningen, J. M.; Daly, S. F.; Vuyovich, C.

    2012-12-01

    storage component. Initial results show that cumulative Gaussian-smoothed TRMM data correlate positively with GRACE CSR during the periods between yearly GRACE minima and maxima at points throughout most watersheds. The timing of peaks in GRACE data in central Afghanistan following the onset of the seasonal SWE decline also corresponds to seasonal rises in the nearby Kajakai Reservoir as measured by Jason-2 satellite altimetry and validated by manual records. Differences between datasets also appear to confirm the irregularities introduced in this region by the CSR 4.1 product that used a land surface model in the signal restoration process.

  5. Characterization of road runoff with regard to seasonal variations, particle size distribution and the correlation of fine particles and pollutants.

    Science.gov (United States)

    Hilliges, R; Endres, M; Tiffert, A; Brenner, E; Marks, T

    2017-03-01

    Urban runoff is known to transport a significant pollutant load consisting of e.g. heavy metals, salts and hydrocarbons. Interactions between solid and dissolved compounds, proper understanding of particle size distribution, dissolved pollutant fractions and seasonal variations is crucial for the selection and development of appropriate road runoff treatment devices. Road runoff at an arterial road in Augsburg, Germany, has been studied for 3.5 years. A strong seasonal variation was observed, with increased heavy metal concentrations with doubled and tripled median concentrations for heavy metals during the cold season. Correlation analysis showed that de-icing salt is not the only factor responsible for increased pollutant concentrations in winter. During the cold period, the fraction of dissolved metals was lower compared to the warm season. In road dust, the highest metal concentrations were measured for fine particles. Metals in road runoff were found to show a significant correlation to fine particles SS63 (removal rates.

  6. Distribution and air-sea exchange of mercury (Hg) in polluted marine environments

    Science.gov (United States)

    Bagnato, E.; Sprovieri, M.; Bitetto, M.; Bonsignore, M.; Calabrese, S.; Di Stefano, V.; Oliveri, E.; Parello, F.; Mazzola, S.

    2012-04-01

    Mercury (Hg) is emitted in the atmosphere by anthropogenic and natural sources, these last accounting for one third of the total emissions. Since the pre-industrial age, the atmospheric deposition of mercury have increased notably, while ocean emissions have doubled owing to the re-emission of anthropogenic mercury. Exchange between the atmosphere and ocean plays an important role in cycling and transport of mercury. We present the preliminary results from a study on the distribution and evasion flux of mercury at the atmosphere/sea interface in the Augusta basin (SE Sicily, southern Italy), a semi-enclosed marine area affected by a high degree of contamination (heavy metals and PHA) due to the oil refineries placed inside its commercial harbor. It seems that the intense industrial activity of the past have lead to an high Hg pollution in the bottom sediments of the basin, whose concentrations are far from the background mercury value found in most of the Sicily Strait sediments. The release of mercury into the harbor seawater and its dispersion by diffusion from sediments to the surface, make the Augusta basin a potential supplier of mercury both to the Mediterranean Sea and the atmosphere. Based on these considerations, mercury concentration and flux at the air-sea interface of the Bay have been estimated using a real-time atomic adsorption spectrometer (LUMEX - RA915+) and an home-made accumulation chamber, respectively. Estimated Total Atmospheric Mercury (TGM) concentrations during the cruise on the bay were in the range of 1-3 ng · m-3, with a mean value of about 1.4 ng · m-3. These data well fit with the background Hgatm concentration values detected on the land (1-2 ng · m-3, this work), and, more in general, with the background atmospheric TGM levels found in the North Hemisphere (1.5-1.7 ng · m-3)a. Besides, our measurements are in the range of those reported for other important polluted marine areas. The mercury evasion flux at the air-sea interface

  7. [Pollution Assessment and Spatial Distribution Characteristics of Heavy Metals in Soils of Coal Mining Area in Longkou City].

    Science.gov (United States)

    Liu, Shuo; Wu, Quan-yuan; Cao, Xue-jiang; Wang, Ji-ning; Zhang, Long-long; Cai, Dong-quan; Zhou, Li-yuan; Liu, Na

    2016-01-15

    The present paper takes the coal mining area of Longkou City as the research area. Thirty-six topsoil (0-20 cm) samples were collected and the contents of 5 kinds of heavy metals were determined, including Cd, As, Ni, Ph, Cr. Geo-statistics analysis was used to analyze the spatial distribution of heavy metals. Principal component analysis (PCA) was used to explore the pollution sources of heavy metals and the degree of heavy metals pollution was evaluated by weighted average comprehensive pollution evaluation method. The results showed that enrichment phenomenon was significant for the 5 kinds of heavy metals. Taking secondary standard of National Environment Quality Standard for Soil as the background value, their exceed standard rates were 72.22%, 100%, 100%, 91.67%, 100%, respectively. Average contents of heavy metals in the soil samples were all over the national standard level two and were 1.53, 11.86, 2.40, 1.31, 4.09 times of the background value. In addition, the average contents were much higher than the background value of the topsoil in the eastern part of Shandong Province and were 9.85, 39.98, 8.85, 4.29, 12.71 times of the background value. According to the semivariogram model, we obtained the nugget-effects of 5 kinds of heavy metals and their values were in the order of As (0.644) > Cd (0.627) > Cr (0.538) > Ni (0.411) > Pb (0.294), all belonging to moderate spatial correlation. On the whole, the central part of the Sangyuan Coal Mine and its surrounding areas were the most seriously polluted, while the pollution of heavy metals in the east and west of the study area was relatively light. Principal component analysis suggested that the enrichment of Cd, As, Ni, Cr was due to irrigation of wastewater, the discharge of industry and enterprise, and the industrial activity. Automobile exhaust and coal combustion were the main pollution sources of Pb. The single-factor assessment of heavy metals pollution showed that the degree of different heavy metals

  8. A geochemical approach to the restoration plans for the Odiel River basin (SW Spain), a watershed deeply polluted by acid mine drainage.

    Science.gov (United States)

    Macías, Francisco; Pérez-López, Rafael; Caraballo, Manuel A; Sarmiento, Aguasanta M; Cánovas, Carlos R; Nieto, Jose M; Olías, Manuel; Ayora, Carlos

    2017-02-01

    The Odiel River Basin (SW Spain) drains the central part of the Iberian Pyrite Belt (IPB), a world-class example of sulfide mining district and concomitantly of acid mine drainage (AMD) pollution. The severe AMD pollution and the incipient state of remediation strategies implemented in this region, coupled with the proximity of the deadline for compliance with the European Water Framework Directive (WFD), urge to develop a restoration and water resources management strategy. Furthermore, despite the presence of some reservoirs with acid waters in the Odiel basin, the construction of the Alcolea water reservoir has already started. On the basis of the positive results obtained after more than 10 years of developing a specific passive remediation technology (dispersed alkaline substrate (DAS)) for the highly polluted AMD of this region, a restoration strategy is proposed. The implementation of 13 DAS treatment plants in selected acid discharges along the Odiel and Oraque sub-basins and other restoration measurements of two acidic creeks is proposed as essential to obtain a good water quality in the future Alcolea reservoir. This restoration strategy is also suggested as an economically and environmentally sustainable approach to the extreme metal pollution affecting the waters of the region and could be considered the starting point for the future compliance with the WFD in the Odiel River Basin.

  9. Correlation of crAssphage-based qPCR markers with culturable and molecular indicators of human fecal pollution in an impacted urban watershed.

    Science.gov (United States)

    Stachler, Elyse; Akyon, Benay; Aquino de Carvalho, Nathalia; Ference, Christian; Bibby, Kyle

    2018-06-06

    Environmental waters are monitored for fecal pollution to protect public health. Many previously developed human-specific fecal pollution indicators lack adequate sensitivity to be reliably detected in environmental waters or do not correlate well with viral pathogens. Recently, two novel human sewage-associated source tracking qPCR markers were developed based on the bacteriophage crAssphage, CPQ_056 and CPQ_064. These assays are highly human specific, abundant in sewage, and are viral-based, suggesting great promise for environmental application as human fecal pollution indicators. A 30-day sampling study was conducted in an urban stream impacted by combined sewer overflows to evaluate the crAssphage markers' performance in an environmental system. The crAssphage markers were present at concentrations of 4.02-6.04 log10 copies/100 mL throughout the study period, indicating their high abundance and ease of detection in polluted environmental waters. In addition, the crAssphage assays were correlated with rain events, molecular markers for human polyomavirus and HF183, as well as culturable E. coli, enterococci, and somatic coliphage. The CPQ_064 assay correlated strongly to a greater number of biological indicators than the CPQ_056 assay. This study is the first to evaluate both crAssphage qPCR assays in an extended environmental application of crAssphage markers for monitoring of environmental waters. It is also the first study to compare crAssphage marker concentration with other viral-based indicators.

  10. Distribution and biological implications of plastic pollution on the fringing reef of Mo’orea, French Polynesia

    Directory of Open Access Journals (Sweden)

    Elizabeth J. Connors

    2017-08-01

    Full Text Available Coral reef ecosystems of the South Pacific are extremely vulnerable to plastic pollution from oceanic gyres and land-based sources. To describe the extent and impact of plastic pollution, the distribution of both macro- (>5 mm and microplastic (plastic < 5 mm of the fringing reef of an isolated South Pacific island, Mo’orea, French Polynesia was quantified. Macroplastic was found on every beach on the island that was surveyed. The distribution of this plastic was categorized by site type and by the presence of Turbinaria ornata, a common macroalgae on Mo’orea. Microplastics were discovered in the water column of the fringing reef of the island, at a concentration of 0.74 pieces m−2. Additionally, this study reports for the first time the ingestion of microplastic by the corallimorpha Discosoma nummiforme. Microplastics were made available to corallimorph polyps in a laboratory setting over the course of 108 h. Positively and negatively buoyant microplastics were ingested, and a microplastic particle that was not experimentally introduced was also discovered in the stomach cavity of one organism. This study indicates that plastic pollution has the potential to negatively impact coral reef ecosystems of the South Pacific, and warrants further study to explore the broader potential impacts of plastic pollution on coral reef ecosystems.

  11. Impact of Yangtze river water transfer on the water quality of the Lixia river watershed, China.

    Directory of Open Access Journals (Sweden)

    Xiaoxue Ma

    Full Text Available To improve water quality and reduce the negative impacts of sudden inputs of water pollution in the Lixia River watershed, China, a series of experimental water transfers from the Yangtze River to the Lixia River were conducted from 2 December 2006 to 7 January 2007. Water samples were collected every six days at 55 monitoring sites during this period. Eight water parameters (water temperature, pH, dissolved oxygen (DO, chemical oxygen demand (COD, potassium permanganate index (CODMn, ammonia nitrogen (NH4+-N, electrical conductivity (EC, and water transparency (WT were analyzed to determine changes in nutrient concentrations during water transfers. The comprehensive pollution index (Pi and single-factor (Si evaluation methods were applied to evaluate spatio-temporal patterns of water quality during water transfers. Water quality parameters displayed different spatial and temporal distribution patterns within the watershed. Water quality was improved significantly by the water transfers, especially for sites closer to water intake points. The degree of improvement is positively related to rates of transfer inflow and drainage outflow. The effects differed for different water quality parameters at each site and at different water transfer times. There were notable decreases in NH4+-N, DO, COD, and CODMn across the entire watershed. However, positive effects on EC and pH were not observed. It is concluded that freshwater transfers from the Yangtze River can be used as an emergency measure to flush pollutants from the Lixia River watershed. Improved understanding of the effects of water transfers on water quality can help the development and implementation of effective strategies to improve water quality within this watershed.

  12. An integrated environmental decision support system for water pollution control based on TMDL--A case study in the Beiyun River watershed.

    Science.gov (United States)

    Zhang, Shanghong; Li, Yueqiang; Zhang, Tianxiang; Peng, Yang

    2015-06-01

    This paper details the development and application of an integrated environmental decision support system (EDSS) for water pollution control based on total maximum daily load (TMDL). The system includes an infrastructure, simulation, and application platforms. Using the water pollution control of Beiyun River in China as a case study, the key development processes and technologies of the EDSS are discussed including relations and links between various environmental simulation models, and model integration, visualization and real-time simulation methods. A loose coupling method is used to connect the environmental models, and an XML file is used to complete data exchange between different models. Project configuration and scheme configuration are used for simulation data organization. The integration approach is easy to implement and enables different development languages and reuse of existing models. The EDSS has been applied to water environment management of Beiyun River, and can be applied to other geographic regions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Asessing the air pollution distribution in busy street of Copenhagen in the further development of a street pollution model

    DEFF Research Database (Denmark)

    Hertel, Ole; Ketzel, Matthias; Poulsen, Maria B.

    The EU Air Quality Directive requires Member States to perform Air Quality Monitoring in order to assess ambient air quality for compliance checking with air quality limit values (http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2008:152:0001:0044:en:PDF). This monitoring needs to include......) developed at AU; the revised version OSPM includes new features like inhomogeneous distribution of the traffic on different lanes, slope of the street etc (see e.g. Ottosen et al. (2015)). An additional goal for the project is to explore the applicability of low-cost electrochemical sensors for describing...... to get more detailed information about the traffic flow and its diurnal pattern, manual traffic counts have been performed over 24 hours. In addition a video camera has been installed on the roof of a building next to the street during the monitoring campaign. Measurements are carried out using passive...

  14. Integrated response and transit time distributions of watersheds by combining hydrograph separation and long-term transit time modeling

    Directory of Open Access Journals (Sweden)

    M. C. Roa-García

    2010-08-01

    Full Text Available We present a new modeling approach analyzing and predicting the Transit Time Distribution (TTD and the Response Time Distribution (RTD from hourly to annual time scales as two distinct hydrological processes. The model integrates Isotope Hydrograph Separation (IHS and the Instantaneous Unit Hydrograph (IUH approach as a tool to provide a more realistic description of transit and response time of water in catchments. Individual event simulations and parameterizations were combined with long-term baseflow simulation and parameterizations; this provides a comprehensive picture of the catchment response for a long time span for the hydraulic and isotopic processes. The proposed method was tested in three Andean headwater catchments to compare the effects of land use on hydrological response and solute transport. Results show that the characteristics of events and antecedent conditions have a significant influence on TTD and RTD, but in general the RTD of the grassland dominated catchment is concentrated in the shorter time spans and has a higher cumulative TTD, while the forest dominated catchment has a relatively higher response distribution and lower cumulative TTD. The catchment where wetlands concentrate shows a flashier response, but wetlands also appear to prolong transit time.

  15. Distribution of intertidal phytobenthos of polluted and comparatively unpolluted regions along Mumbai

    Digital Repository Service at National Institute of Oceanography (India)

    Paralkar, M.N.

    act as traps for contaminants or as bio indicator species in these polluted areas. The changes in microphytobenthic community structure, alteration in pigments corresponding to the increasing depth of the sediments, are the major theme of present study...

  16. Distribution and origin sources of Polycyclic Aromatic Hydrocarbons (PAHs) pollution in sediment of Sarawak coastal area

    International Nuclear Information System (INIS)

    Mohd Shuhaimi Elias; Abdul Khalik Wood; Zaleha Hashim; Mohd Suhaimi Hamzah; Shamsiah Abdul Rahman; Nazaratul Ashifa Abdullah Salim

    2010-01-01

    Alkyl and parent Polycyclic Aromatic Hydrocarbons (PAHs) compounds in marine sediment sample collected from ten locations along Sarawak coastal areas were extracted and analyzed by using gas chromatography-mass spectrometry. The source identification of PAH pollution in marine sediment of Sarawak coastal areas were identify by ratios technique of An/ An+phen, Fl/ Fl +Py, B[a]A/ (B[a]A+Chry) and total Methyl Phen/ Phen. The total alkyl and parent PAHs concentration varies from 36.5 - 277.4 ng/ g dry weight (d.w.) with a mean concentration of 138.2 ng/ g d.w. The ratio values of PAHs pollution in marine sediment of Sarawak coastal areas are clearly indicating the PAHs pollutions are originated from petroleum (petrogenic) and petroleum combustion (pyrolytic). However, the origin sources of PAHs pollution in a few stations were uncertain due to mixing sources of PAHs. (author)

  17. Pollutants transport and distribution studies in groundwater system by nuclear, geophysics and hydrogeochemical methods

    International Nuclear Information System (INIS)

    Mohd Tadza Abdul Rahman; Daud Mohamad

    2000-01-01

    In Malaysia, the most common means of managing municipal refuse is by dumping it indiscriminately in piles on the selected open land. Leachate that is formed primarily in association with precipitation that infiltrates through the refuse normally results in the migration of leachate into underlying groundwater zone. The study of pollutant transport derived from domestic refuse and their impact on water quality in groundwater system has been performed in a selected landfill site at Gemencheh, Negeri Sembilan. The study involved the determination of flow velocity and flow direction of pollutants by nuclear techniques and a detail survey by geophysical method as well as hydrogeochemical approach as a supporting evidence of pollution occurrence. Hydrogeochemical approach involved the determination of pollutants species such as chloride and nitrate. A network of about 30 observation points had been identified and sampled. The results of the study have shown that the pollutants were concentrated at the middle of the dumping site and transported with the flow velocity between 0.2-15.4 metres per day toward northeast direction. Furthermore, the study established that the municipal or domestic landfalls are considered as one of the potential sources of groundwater pollution in Malaysia

  18. Stormwater management network effectiveness and implications for urban watershed function: A critical review

    Science.gov (United States)

    Jefferson, Anne J.; Bhaskar, Aditi S.; Hopkins, Kristina G.; Fanelli, Rosemary; Avellaneda, Pedro M.; McMillan, Sara K.

    2017-01-01

    Deleterious effects of urban stormwater are widely recognized. In several countries, regulations have been put into place to improve the conditions of receiving water bodies, but planning and engineering of stormwater control is typically carried out at smaller scales. Quantifying cumulative effectiveness of many stormwater control measures on a watershed scale is critical to understanding how small-scale practices translate to urban river health. We review 100 empirical and modelling studies of stormwater management effectiveness at the watershed scale in diverse physiographic settings. Effects of networks with stormwater control measures (SCMs) that promote infiltration and harvest have been more intensively studied than have detention-based SCM networks. Studies of peak flows and flow volumes are common, whereas baseflow, groundwater recharge, and evapotranspiration have received comparatively little attention. Export of nutrients and suspended sediments have been the primary water quality focus in the United States, whereas metals, particularly those associated with sediments, have received greater attention in Europe and Australia. Often, quantifying cumulative effects of stormwater management is complicated by needing to separate its signal from the signal of urbanization itself, innate watershed characteristics that lead to a range of hydrologic and water quality responses, and the varying functions of multiple types of SCMs. Biases in geographic distribution of study areas, and size and impervious surface cover of watersheds studied also limit our understanding of responses. We propose hysteretic trajectories for how watershed function responds to increasing imperviousness and stormwater management. Even where impervious area is treated with SCMs, watershed function may not be restored to its predevelopment condition because of the lack of treatment of all stormwater generated from impervious surfaces; non-additive effects of individual SCMs; and

  19. Water pollution and distribution of the black fly (Diptera: Simuliidae in the Atlantic Forest, Brazil

    Directory of Open Access Journals (Sweden)

    Tatiana N Docile

    2015-09-01

    Full Text Available Abstract:Black flies have medical importance because some species are vectors of the Onchocerciasis and Mansonelosis, nevertheless, their ecology and potential use as bioindicators is still poorly studied in the Neotropical Region. In Brazil, bioindicators use is strongly focused in a multimetrical ecological index approach; this way, we investigated the black fly spatial distribution, in relation to abiotic factors correlated to water quality, to provide baseline information for their utilization as standalone indicators of lotic systems integrity. We have tested the hypothesis that environmental changes related to urbanization, lead to decreased abundance and loss in the number of species of the black fly fauna. The sampling was conducted in 10 urban and 10 preserved streams during the dry season (August-September of 2012, in the mountainous region of Teresópolis, State of Rio de Janeiro, Brazil. The streams were characterized for their environmental integrity conditions and physico-chemical properties of water. In each stream, five different rapid points were sampled in a section of 50 meters, 10 meters apart from each other. The black flies were sampled with a kick-net sampler on rocky substrates. The material was separated and the larvae were sorted in morphotypes, and later, the final instar specimens were dissected and identified with the help of taxonomical literature at species level. A total abundance of 488 larvae from nine species were collected, 5 (1.02 % in extremely impacted streams, 470 (96.31 % in intermediate streams and 13 (2.66 % in preserved streams. The visual evaluation (HII differed in rela&tion to the water physico-chemical evaluation, in which more variation in the characterization of the sampling sites was observed. In Canonical Correspondence Analysis Simulium subpallidum, S. inscrustatumand S. pertinaxwere significantly associated with intermediate values of most of the variables, and then to intermediate impacted

  20. Sensitivity of air pollution simulations with LOTOS-EUROS to temporal distribution of anthropogenic emissions

    Science.gov (United States)

    Mues, A.; Kuenen, J.; Hendriks, C.; Manders, A.; Segers, A.; Scholz, Y.; Hueglin, C.; Builtjes, P.; Schaap, M.

    2013-07-01

    In this study the sensitivity of the model performance of the chemistry transport model (CTM) LOTOS-EUROS to the description of the temporal variability of emissions was investigated. Currently the temporal release of anthropogenic emissions is described by European average diurnal, weekly and seasonal time profiles per sector. These default time profiles largely neglect the variation of emission strength with activity patterns, region, species, emission process and meteorology. The three sources dealt with in this study are combustion in energy and transformation industries (SNAP1), non-industrial combustion (SNAP2) and road transport (SNAP7). First the impact of neglecting the temporal emission profiles for these SNAP categories on simulated concentrations was explored. In a~second step, we constructed more detailed emission time profiles for the three categories and quantified their impact on the model performance separately as well as combined. The performance in comparison to observations for Germany was quantified for the pollutants NO2, SO2 and PM10 and compared to a simulation using the default LOTOS-EUROS emission time profiles. In general the largest impact on the model performance was found when neglecting the default time profiles for the three categories. The daily average correlation coefficient for instance decreased by 0.04 (NO2), 0.11 (SO2) and 0.01 (PM10) at German urban background stations compared to the default simulation. A systematic increase of the correlation coefficient is found when using the new time profiles. The size of the increase depends on the source category, the component and station. Using national profiles for road transport showed important improvements of the explained variability over the weekdays as well as the diurnal cycle for NO2. The largest impact of the SNAP1 and 2 profiles were found for SO2. When using all new time profiles simultaneously in one simulation the daily average correlation coefficient increased by 0

  1. Sensitivity of air pollution simulations with LOTOS-EUROS to the temporal distribution of anthropogenic emissions

    Science.gov (United States)

    Mues, A.; Kuenen, J.; Hendriks, C.; Manders, A.; Segers, A.; Scholz, Y.; Hueglin, C.; Builtjes, P.; Schaap, M.

    2014-01-01

    In this study the sensitivity of the model performance of the chemistry transport model (CTM) LOTOS-EUROS to the description of the temporal variability of emissions was investigated. Currently the temporal release of anthropogenic emissions is described by European average diurnal, weekly and seasonal time profiles per sector. These default time profiles largely neglect the variation of emission strength with activity patterns, region, species, emission process and meteorology. The three sources dealt with in this study are combustion in energy and transformation industries (SNAP1), nonindustrial combustion (SNAP2) and road transport (SNAP7). First of all, the impact of neglecting the temporal emission profiles for these SNAP categories on simulated concentrations was explored. In a second step, we constructed more detailed emission time profiles for the three categories and quantified their impact on the model performance both separately as well as combined. The performance in comparison to observations for Germany was quantified for the pollutants NO2, SO2 and PM10 and compared to a simulation using the default LOTOS-EUROS emission time profiles. The LOTOS-EUROS simulations were performed for the year 2006 with a temporal resolution of 1 h and a horizontal resolution of approximately 25 × 25km2. In general the largest impact on the model performance was found when neglecting the default time profiles for the three categories. The daily average correlation coefficient for instance decreased by 0.04 (NO2), 0.11 (SO2) and 0.01 (PM10) at German urban background stations compared to the default simulation. A systematic increase in the correlation coefficient is found when using the new time profiles. The size of the increase depends on the source category, component and station. Using national profiles for road transport showed important improvements in the explained variability over the weekdays as well as the diurnal cycle for NO2. The largest impact of the SNAP1

  2. Water pollution and distribution of the black fly (Diptera: Simuliidae) in the Atlantic Forest, Brazil.

    Science.gov (United States)

    Docile, Tatiana N; Figueiró, Ronaldo; Gil-Azevedo, Leonardo H; Nessimian, Jorge L

    2015-09-01

    Black flies have medical importance because some species are vectors of the unenocerciasis and Mansonelosis, nevertheless, their ecology and potential use as bioindicators is still poorly studied in the Neotropical Region. In Brazil, bioindicators use is strongly focused in a multimetrical ecological index approach; this way, we investigated the black fly spatial distribution, in relation to abiotic factors correlated to water quality, to provide baseline information for their utilization as standalone indicators of lotic systems integrity. We have tested the hypothesis that environmental changes related to urbanization, lead to decreased abundance and loss in the number of species of the black fly fauna. The sampling was conducted in 10 urban and 10 preserved streams during the dry season (August-September) of 2012, in the mountainous region of Teres6polis, State of Rio de Janeiro, Brazil. The streams were characterized for their environmental integrity conditions and physico-chemical properties of water. In each stream, five different rapid points were sampled in a section of 50 meters, 10 meters apart from each other. The black flies were sampled with a kick-net sampler on rocky substrates. The material was separated and the larvae were sorted in morphotypes, and later, the final instar specimens were dissected and identified with the help of taxonomical literature at species level. A total abundance of 488 larvae from nine species were collected, 5 (1.02 %) in extremely impacted streams, 470 (96.31 %) in intermediate streams and 13 (2.66 %) in preserved streams. The visual evaluation (HII) differed in relation to the water physico-chemical evaluation, in which more variation in the characterization of the sampling sites was observed. In Canonical Correspondence Analysis Simulium subpallidum, S. inscrustatum and S. pertinax were significantly associated with intermediate values of most of the variables, and then to intermediate impacted sites. On the other hand

  3. Application of tethered balloon for studying vertical distribution of air pollutants within lower tropsphere of Shanghai

    Science.gov (United States)

    Zhang, K.; Wang, D.; Fu, Q.; Xiu, G.; Duan, Y.

    2016-12-01

    Tethered balloon-based measurement campaign of particle number concentration (PNC) and particle number size distribution (PNSD) in the range of 15.7-661.2 nm was conducted within the lower troposphere of 1000 m in Shanghai, a Chinses megacity, in December 2015. The meteorological condition, PNC, and PNSD were synchronous measured at ground-based station as well as on the tethered balloon. Overall, the mixing layer height (MLH) showed a peak at about LST 14:00-15:00. On ground level, the 88.2 nm particles had the highest number concentration. The Pearson correlation analysis based on the ground level data shows the Pearson correlation coefficient between PNC and NO2was 0.774. The synchronous measurement of PNC and PNSD on ground level and on the tethered balloon showed the 15.7-200 nm particles had higher PNC on ground level, but the PNC of 200-661.2 nm particles are higher at 400 m. And the wind condition showed a strong influence on PNC.The vertical profiles of meteorological parameters and air pollutants was observed. The particle mass concentration, ozone concentration, temperature, and humidity all showed a quick change when the balloon across the atmosphere boundary layer. One episodic haze event (Dec 22nd-Dec 23rd) was selected with specific focus on the variation of PNSD and PNC vertical profiles. Before the haze, the PNC at ground was 9281 cm-3. The MaxDm (the particle diameter with the highest number concentration) was 53.3 nm at that time. Due to the shallow MLH, the MaxDm changed rapidly to 126.3 nm at 321 m. During the haze, the MaxDm and the PNC on ground level was 126.3 nm and 18515 cm-3 respectively. And a quick drop of PNC was observed at 553 m. This may due to the change of wind direction, temperature, and relative humidity. At the end of haze, the MaxDm and the PNC on ground level was 126.3 nm and 10711 cm-3 respectively. The highest MaxDm during those three launches all appeared at a high altitude, usually above 300 m. This result is consisted

  4. Simulation of net infiltration and potential recharge using a distributed-parameter watershed model of the Death Valley region, Nevada and California

    Science.gov (United States)

    Hevesi, Joseph A.; Flint, Alan L.; Flint, Lorraine E.

    2003-01-01

    This report presents the development and application of the distributed-parameter watershed model, INFILv3, for estimating the temporal and spatial distribution of net infiltration and potential recharge in the Death Valley region, Nevada and California. The estimates of net infiltration quantify the downward drainage of water across the lower boundary of the root zone and are used to indicate potential recharge under variable climate conditions and drainage basin characteristics. Spatial variability in recharge in the Death Valley region likely is high owing to large differences in precipitation, potential evapotranspiration, bedrock permeability, soil thickness, vegetation characteristics, and contributions to recharge along active stream channels. The quantity and spatial distribution of recharge representing the effects of variable climatic conditions and drainage basin characteristics on recharge are needed to reduce uncertainty in modeling ground-water flow. The U.S. Geological Survey, in cooperation with the Department of Energy, developed a regional saturated-zone ground-water flow model of the Death Valley regional ground-water flow system to help evaluate the current hydrogeologic system and the potential effects of natural or human-induced changes. Although previous estimates of recharge have been made for most areas of the Death Valley region, including the area defined by the boundary of the Death Valley regional ground-water flow system, the uncertainty of these estimates is high, and the spatial and temporal variability of the recharge in these basins has not been quantified. To estimate the magnitude and distribution of potential recharge in response to variable climate and spatially varying drainage basin characteristics, the INFILv3 model uses a daily water-balance model of the root zone with a primarily deterministic representation of the processes controlling net infiltration and potential recharge. The daily water balance includes precipitation

  5. Associations between maternal weekly air pollutant exposures and low birth weight: a distributed lag non-linear model

    Science.gov (United States)

    Wu, Han; Jiang, Baofa; Zhu, Ping; Geng, Xingyi; Liu, Zhong; Cui, Liangliang; Yang, Liping

    2018-02-01

    When discussing the association between birth weight and air pollution, previous studies mainly focus on the maternal trimester-specific exposures during pregnancy, whereas the possible associations between birth weight and weekly-specific exposures have been largely neglected. We conducted a nested 1:4 matched case-control study in Jinan, China to examine the weekly-specific associations during pregnancy between maternal fine particulate matter (aerodynamic diameter gender-, gestational age-, and parity-specific standard score (BWGAP z-score) was calculated as the outcome of interest. Distributed lag non-linear models (DLNMs) were applied to estimate weekly-specific relationship between maternal air pollutant exposures and birth weight. For an increase of per inter-quartile range in maternal PM2.5 exposure concentration during pregnancy, the BWGAP z-score decreased significantly during the 27th-33th gestational weeks with the strongest association in the 30th gestational weeks (standard deviation units decrease in BWGAP z-score: -0.049, 95% CI: -0.080 -0.017, in three-pollutant model). No significant association between maternal weekly NO2 or SO2 BWGAP z-score was observed. In conclusion, this study provides evidence that maternal PM2.5 exposure during the 27th-33th gestational weeks may reduce the birth weight in the context of very high pollution level of PM2.5.

  6. Distribution and biological implications of plastic pollution on the fringing reef of Mo'orea, French Polynesia.

    Science.gov (United States)

    Connors, Elizabeth J

    2017-01-01

    Coral reef ecosystems of the South Pacific are extremely vulnerable to plastic pollution from oceanic gyres and land-based sources. To describe the extent and impact of plastic pollution, the distribution of both macro- (>5 mm) and microplastic (plastic plastic was categorized by site type and by the presence of Turbinaria ornata, a common macroalgae on Mo'orea. Microplastics were discovered in the water column of the fringing reef of the island, at a concentration of 0.74 pieces m -2 . Additionally, this study reports for the first time the ingestion of microplastic by the corallimorpha Discosoma nummiforme. Microplastics were made available to corallimorph polyps in a laboratory setting over the course of 108 h. Positively and negatively buoyant microplastics were ingested, and a microplastic particle that was not experimentally introduced was also discovered in the stomach cavity of one organism. This study indicates that plastic pollution has the potential to negatively impact coral reef ecosystems of the South Pacific, and warrants further study to explore the broader potential impacts of plastic pollution on coral reef ecosystems.

  7. Distribution and biological implications of plastic pollution on the fringing reef of Mo’orea, French Polynesia

    Science.gov (United States)

    2017-01-01

    Coral reef ecosystems of the South Pacific are extremely vulnerable to plastic pollution from oceanic gyres and land-based sources. To describe the extent and impact of plastic pollution, the distribution of both macro- (>5 mm) and microplastic (plastic plastic was categorized by site type and by the presence of Turbinaria ornata, a common macroalgae on Mo’orea. Microplastics were discovered in the water column of the fringing reef of the island, at a concentration of 0.74 pieces m−2. Additionally, this study reports for the first time the ingestion of microplastic by the corallimorpha Discosoma nummiforme. Microplastics were made available to corallimorph polyps in a laboratory setting over the course of 108 h. Positively and negatively buoyant microplastics were ingested, and a microplastic particle that was not experimentally introduced was also discovered in the stomach cavity of one organism. This study indicates that plastic pollution has the potential to negatively impact coral reef ecosystems of the South Pacific, and warrants further study to explore the broader potential impacts of plastic pollution on coral reef ecosystems. PMID:28875079

  8. Using continuous sampling to examine the distribution of traffic related air pollution in proximity to a major road

    Science.gov (United States)

    McAdam, Kim; Steer, Peter; Perrotta, Kim

    2011-04-01

    A study to characterize the distribution of vehicle related air pollution in proximity to a major arterial road was undertaken to inform local land use planning and policy regarding separation distances that could help reduce exposure for new sensitive land use development. Measurements of criteria air contaminants were made at ground level, 10 m, 30 m, and 60 m from curb side, and at 9 m height, 10 m from curb side along a traffic corridor carrying over 34,000 vehicles per day. Pollutant decay with distance or height was not statistically significant for O 3, CO, or SO 2. No clear distance decay pattern emerged for PM 2.5. Compared to concentrations at ground level 30 m from curb side, concentrations at 10 m, 60 m, and 10 m at 9 m height were 83%, 45% and 54% higher, respectively. For NO, NO 2, and NO x, however, there was a statistically significant decline in concentrations with distance with the decay most apparent from 30 m to 60 m from the road. Concentrations at 10 m from curb side at 9 m height were equivalent to (all wind conditions) or less than (downwind conditions) those at 30 m and ground level. These findings suggest that for protection of public health in the near road environment, vertical distance is an important determinant of exposure to pollutants that are key indicators of traffic related air pollution. This has implications for sensitive land use development in proximity to high volume traffic corridors.

  9. Concentrations and geographic distribution of selected organic pollutants in Scottish surface soils

    International Nuclear Information System (INIS)

    Rhind, S.M.; Kyle, C.E.; Kerr, C.; Osprey, M.; Zhang, Z.L.; Duff, E.I.; Lilly, A.; Nolan, A.; Hudson, G.; Towers, W.; Bell, J.; Coull, M.; McKenzie, C.

    2013-01-01

    Concentrations of selected persistent organic pollutants (POPs) representing three chemical classes (polycyclic aromatic hydrocarbons (PAH), polybrominated diphenyl ethers (PBDE) and polychlorinated biphenyls (PCB) and the organic pollutant diethylhexyl phthalate (DEHP), were determined in surface soil samples (0–5 cm) collected at 20 km grid intersects throughout Scotland over a three-year period. Detectable amounts of all chemical classes and most individual congeners were present in all samples. There were no consistent effects of soil or vegetation type, soil carbon content, pH, altitude or distance from centres of population on concentrations which exhibited extreme variation, even in adjacent samples. It is concluded that soil POPs and DEHP concentrations and associated rates of animal and human exposure were highly variable, influenced by multiple, interacting factors, and not clearly related to local sources but possibly related to wet atmospheric deposition and the organic carbon content of the soil. -- Highlights: •Concentrations of selected organic pollutants in Scottish soils were determined. •Concentrations were highly variable. •There were few effects of soil or vegetation type, soil carbon, pH or altitude. •Distance from cities was not an important determinant of concentrations. •Atmospheric deposition and soil organic carbon content may affect concentrations. -- Soil concentrations of anthropogenic persistent organic pollutants are not clearly related to soil type or pH, vegetation, altitude, or distance from pollutant sources

  10. The combined use of MODFLOW and precipitation-runoff modeling to simulate groundwater flow in a diffuse-pollution prone watershed.

    Science.gov (United States)

    Elçi, A; Karadaş, D; Fistikoğlu, O

    2010-01-01

    A numerical modeling case study of groundwater flow in a diffuse pollution prone area is presented. The study area is located within the metropolitan borders of the city of Izmir, Turkey. This groundwater flow model was unconventional in the application since the groundwater recharge parameter in the model was estimated using a lumped, transient water-budget based precipitation-runoff model that was executed independent of the groundwater flow model. The recharge rate obtained from the calibrated precipitation-runoff model was used as input to the groundwater flow model, which was eventually calibrated to measured water table elevations. Overall, the flow model results were consistent with field observations and model statistics were satisfactory. Water budget results of the model revealed that groundwater recharge comprised about 20% of the total water input for the entire study area. Recharge was the second largest component in the budget after leakage from streams into the subsurface. It was concluded that the modeling results can be further used as input for contaminant transport modeling studies in order to evaluate the vulnerability of water resources of the study area to diffuse pollution.

  11. Distribution and pollution assessment of heavy metals in surface sediments in the Yellow Sea.

    Science.gov (United States)

    Jiang, Xin; Teng, Ankang; Xu, Wenzhe; Liu, Xiaoshou

    2014-06-15

    Heavy metal concentrations in surface sediments at 56 stations during two cruises in the Yellow Sea in summer and winter, 2011 were analyzed by inductively coupled plasma-mass spectrometry. The pollution status was assessed via the Geoaccumulation index and Hankanson potential ecological risk index. Higher concentrations of heavy metals (except for Mn) were found in the central Southern Yellow Sea and the western Northern Yellow Sea. The higher contents of Mn were much closer to Shandong Peninsula. Correlation analyses indicated that Pb, Cu, Fe, Ni, Zn and Co probably had the same origin and were controlled by grain size and total organic carbon. Pollution assessment showed that most areas of the Yellow Sea were not or lowly contaminated with the exception of the northwest and south parts of the Southern Yellow Sea showing Cd-contamination. The pollution status of the Yellow Sea in summer was worse than that in winter. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Monitoring of emerging pollutants in Guadiamar River basin (South of Spain): analytical method, spatial distribution and environmental risk assessment.

    Science.gov (United States)

    Garrido, Eva; Camacho-Muñoz, Dolores; Martín, Julia; Santos, Antonio; Santos, Juan Luis; Aparicio, Irene; Alonso, Esteban

    2016-12-01

    Guadiamar River is located in the southwest of the Iberian Peninsula and connects two protected areas in the South of Spain: Sierra Morena and Doñana National Park. It is sited in an area affected by urban, industrial and agriculture sewage pollution and with tradition on intensive mining activities. Most of the studies performed in this area have been mainly focused on the presence of heavy metals and, until now, little is known about the occurrence of other contaminants such as emerging organic pollutants (EOPs). In this work, an analytical method has been optimized and validated for monitoring of forty-seven EOPs in surface water. The analytical method has been applied to study the distribution and environmental risk of these pollutants in Guadiamar River basin. The analytical method was based on solid-phase extraction and determination by liquid chromatography-triple quadrupole-tandem mass spectrometry. The 60 % of the target compounds were found in the analyzed samples. The highest concentrations were found for two plasticizers (bisphenol A and di(2-ethyhexyl)phthalate, mean concentration up to 930 ng/L) and two pharmaceutical compounds (caffeine (up to 623 ng/L) and salicylic acid (up to 318 ng/L)). This study allowed to evaluate the potential sources (industrial or urban) of the studied compounds and the spatial distribution of their concentrations along the river. Environmental risk assessment showed a major risk on the south of the river, mainly due to discharges of wastewater effluents.

  13. Coupling impervious surface rate derived from satellite remote sensing with distributed hydrological model for highly urbanized watershed flood forecasting

    Science.gov (United States)

    Dong, L.

    2017-12-01

    Abstract: The original urban surface structure changed a lot because of the rapid development of urbanization. Impermeable area has increased a lot. It causes great pressure for city flood control and drainage. Songmushan reservoir basin with high degree of urbanization is taken for an example. Pixel from Landsat is decomposed by Linear spectral mixture model and the proportion of urban area in it is considered as impervious rate. Based on impervious rate data before and after urbanization, an physically based distributed hydrological model, Liuxihe Model, is used to simulate the process of hydrology. The research shows that the performance of the flood forecasting of high urbanization area carried out with Liuxihe Model is perfect and can meet the requirement of the accuracy of city flood control and drainage. The increase of impervious area causes conflux speed more quickly and peak flow to be increased. It also makes the time of peak flow advance and the runoff coefficient increase. Key words: Liuxihe Model; Impervious rate; City flood control and drainage; Urbanization; Songmushan reservoir basin

  14. Retrospective Review of Watershed Characteristics and a Framework for Future Research in the Sarasota Bay Watershed, Florida

    Science.gov (United States)

    Kish, George R.; Harrison, Arnell S.; Alderson, Mark

    2008-01-01

    The U.S. Geological Survey, in cooperation with the Sarasota Bay Estuary Program conducted a retrospective review of characteristics of the Sarasota Bay watershed in west-central Florida. This report describes watershed characteristics, surface- and ground-water processes, and the environmental setting of the Sarasota Bay watershed. Population growth during the last 50 years is transforming the Sarasota Bay watershed from rural and agriculture to urban and suburban. The transition has resulted in land-use changes that influence surface- and ground-water processes in the watershed. Increased impervious cover decreases recharge to ground water and increases overland runoff and the pollutants carried in the runoff. Soil compaction resulting from agriculture, construction, and recreation activities also decreases recharge to ground water. Conventional approaches to stormwater runoff have involved conveyances and large storage areas. Low-impact development approaches, designed to provide recharge near the precipitation point-of-contact, are being used increasingly in the watershed. Simple pollutant loading models applied to the Sarasota Bay watershed have focused on large-scale processes and pollutant loads determined from empirical values and mean event concentrations. Complex watershed models and more intensive data-collection programs can provide the level of information needed to quantify (1) the effects of lot-scale land practices on runoff, storage, and ground-water recharge, (2) dry and wet season flux of nutrients through atmospheric deposition, (3) changes in partitioning of water and contaminants as urbanization alters predevelopment rainfall-runoff relations, and (4) linkages between watershed models and lot-scale models to evaluate the effect of small-scale changes over the entire Sarasota Bay watershed. As urbanization in the Sarasota Bay watershed continues, focused research on water-resources issues can provide information needed by water

  15. Effect of industrial pollution on the distribution dynamics of radionuclides in boreal understorey ecosystems (EPORA). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Suomela, M.; Rahola, T. [Radiation and Nuclear Safety Authority, Helsinki (Finland); Bergman, R. [National Defence Research Establishment (Sweden); Bunzl, K. [National Research Center for Environmental and Health (Germany); Jaakkola, T. [Helsinki Univ. (Finland). Radiochemical Lab.; Steinnes, E. [Norwegian University of Science and Technology (Norway)

    1999-08-01

    The project EPORA 'Effects of Industrial Pollution on Distribution Dynamics of Radionuclides in Boreal Understorey Ecosystems' is a part of the Nuclear Fission Safety Research programme of the European Union. A suitable environment for the study was found in the surroundings of the Cu-Ni smelter in Monchegorsk, in NW Russia where the huge atmospheric emissions from the smelter have polluted the environment since the 1930's. Samples of soil, litter, plants and runoff water were taken. Total concentrations of the mainpollutants, Ni and Cu, in the organic soil increased from about 10 mg kg{sup -1} at the reference site in Finland to about 5000 mg kg{sup -1} at the most polluted site in Russia. Similar trends were observed for exchangeable fractions and plant concentrations of the same elements. Concentrations of exchangeable K, Ca, and Mg in the organic soil decreased strongly with increased input of chemical pollutants. The radionuclides studied were {sup 137}Cs, {sup 90}Sr and {sup 239+240}Pu, mainly originating from the atmospheric nuclear weapons tests. The contribution of the Chernobyl derived {sup 137}Cs deposition was about 10% but insignificant for the other nuclides. The activity distribution of all three radionuclides in the soil, their corresponding residence half-times as well as their aggregated trencher factors for various plants depended on the degree of pollution: Activity distribution: in the litter layer, the activity of all three radionuclides increased continually from the reference site to the most polluted site. This effect was most pronounced for {sup 239+240}Pu and least for {sup 90}Sr and could, at least partly, be explained by the increase of the thickness of this layer. In the root zone, the opposite effect was observed: the largest fraction of all radionuclides was found at the reference site. In the organic layer, the exchangeable fractions of {sup 137}Cs, {sup 90}Sr and {sup 239+240}Pu decreased with increasing pollution

  16. Statistical Analysis of Spatiotemporal Heterogeneity of the Distribution of Air Quality and Dominant Air Pollutants and the Effect Factors in Qingdao Urban Zones

    Directory of Open Access Journals (Sweden)

    Xiangwei Zhao

    2018-04-01

    Full Text Available Air pollution has impacted people’s lives in urban China, and the analysis of the distribution and driving factors behind air quality has become a current research focus. In this study, the temporal heterogeneity of air quality (AQ and the dominant air pollutants across the four seasons were analyzed based on the Kruskal-Wallis rank-sum test method. Then, the spatial heterogeneity of AQ and the dominant air pollutants across four sites were analyzed based on the Wilcoxon signed-rank test method. Finally, the copula model was introduced to analyze the effect of relative factors on dominant air pollutants. The results show that AQ and dominant air pollutants present significant spatiotemporal heterogeneity in the study area. AQ is worst in winter and best in summer. PM10, O3, and PM2.5 are the dominant air pollutants in spring, summer, and winter, respectively. The average concentration of dominant air pollutants presents significant and diverse daily peaks and troughs across the four sites. The main driving factors are pollutants such as SO2, NO2, and CO, so pollutant emission reduction is the key to improving air quality. Corresponding pollution control measures should account for this heterogeneity in terms of AQ and the dominant air pollutants among different urban zones.

  17. Spatial Distribution of Stony Desertification and Key Influencing Factors on Different Sampling Scales in Small Karst Watersheds

    Science.gov (United States)

    Zhang, Zhenming; Zhou, Yunchao; Wang, Shijie

    2018-01-01

    Karst areas are typical ecologically fragile areas, and stony desertification has become the most serious ecological and economic problems in these areas worldwide as well as a source of disasters and poverty. A reasonable sampling scale is of great importance for research on soil science in karst areas. In this paper, the spatial distribution of stony desertification characteristics and its influencing factors in karst areas are studied at different sampling scales using a grid sampling method based on geographic information system (GIS) technology and geo-statistics. The rock exposure obtained through sampling over a 150 m × 150 m grid in the Houzhai River Basin was utilized as the original data, and five grid scales (300 m × 300 m, 450 m × 450 m, 600 m × 600 m, 750 m × 750 m, and 900 m × 900 m) were used as the subsample sets. The results show that the rock exposure does not vary substantially from one sampling scale to another, while the average values of the five subsamples all fluctuate around the average value of the entire set. As the sampling scale increases, the maximum value and the average value of the rock exposure gradually decrease, and there is a gradual increase in the coefficient of variability. At the scale of 150 m × 150 m, the areas of minor stony desertification, medium stony desertification, and major stony desertification in the Houzhai River Basin are 7.81 km2, 4.50 km2, and 1.87 km2, respectively. The spatial variability of stony desertification at small scales is influenced by many factors, and the variability at medium scales is jointly influenced by gradient, rock content, and rock exposure. At large scales, the spatial variability of stony desertification is mainly influenced by soil thickness and rock content. PMID:29652811

  18. Spatial Distribution of Stony Desertification and Key Influencing Factors on Different Sampling Scales in Small Karst Watersheds

    Directory of Open Access Journals (Sweden)

    Zhenming Zhang

    2018-04-01

    Full Text Available Karst areas are typical ecologically fragile areas, and stony desertification has become the most serious ecological and economic problems in these areas worldwide as well as a source of disasters and poverty. A reasonable sampling scale is of great importance for research on soil science in karst areas. In this paper, the spatial distribution of stony desertification characteristics and its influencing factors in karst areas are studied at different sampling scales using a grid sampling method based on geographic information system (GIS technology and geo-statistics. The rock exposure obtained through sampling over a 150 m × 150 m grid in the Houzhai River Basin was utilized as the original data, and five grid scales (300 m × 300 m, 450 m × 450 m, 600 m × 600 m, 750 m × 750 m, and 900 m × 900 m were used as the subsample sets. The results show that the rock exposure does not vary substantially from one sampling scale to another, while the average values of the five subsamples all fluctuate around the average value of the entire set. As the sampling scale increases, the maximum value and the average value of the rock exposure gradually decrease, and there is a gradual increase in the coefficient of variability. At the scale of 150 m × 150 m, the areas of minor stony desertification, medium stony desertification, and major stony desertification in the Houzhai River Basin are 7.81 km2, 4.50 km2, and 1.87 km2, respectively. The spatial variability of stony desertification at small scales is influenced by many factors, and the variability at medium scales is jointly influenced by gradient, rock content, and rock exposure. At large scales, the spatial variability of stony desertification is mainly influenced by soil thickness and rock content.

  19. Spatial Distribution of Stony Desertification and Key Influencing Factors on Different Sampling Scales in Small Karst Watersheds.

    Science.gov (United States)

    Zhang, Zhenming; Zhou, Yunchao; Wang, Shijie; Huang, Xianfei

    2018-04-13

    Karst areas are typical ecologically fragile areas, and stony desertification has become the most serious ecological and economic problems in these areas worldwide as well as a source of disasters and poverty. A reasonable sampling scale is of great importance for research on soil science in karst areas. In this paper, the spatial distribution of stony desertification characteristics and its influencing factors in karst areas are studied at different sampling scales using a grid sampling method based on geographic information system (GIS) technology and geo-statistics. The rock exposure obtained through sampling over a 150 m × 150 m grid in the Houzhai River Basin was utilized as the original data, and five grid scales (300 m × 300 m, 450 m × 450 m, 600 m × 600 m, 750 m × 750 m, and 900 m × 900 m) were used as the subsample sets. The results show that the rock exposure does not vary substantially from one sampling scale to another, while the average values of the five subsamples all fluctuate around the average value of the entire set. As the sampling scale increases, the maximum value and the average value of the rock exposure gradually decrease, and there is a gradual increase in the coefficient of variability. At the scale of 150 m × 150 m, the areas of minor stony desertification, medium stony desertification, and major stony desertification in the Houzhai River Basin are 7.81 km², 4.50 km², and 1.87 km², respectively. The spatial variability of stony desertification at small scales is influenced by many factors, and the variability at medium scales is jointly influenced by gradient, rock content, and rock exposure. At large scales, the spatial variability of stony desertification is mainly influenced by soil thickness and rock content.

  20. Source apportionment of aerosol particles at a European air pollution hot spot using particle number size distributions and chemical composition.

    Science.gov (United States)

    Leoni, Cecilia; Pokorná, Petra; Hovorka, Jan; Masiol, Mauro; Topinka, Jan; Zhao, Yongjing; Křůmal, Kamil; Cliff, Steven; Mikuška, Pavel; Hopke, Philip K

    2018-03-01

    Ostrava in the Moravian-Silesian region (Czech Republic) is a European air pollution hot spot for airborne particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and ultrafine particles (UFPs). Air pollution source apportionment is essential for implementation of successful abatement strategies. UFPs or nanoparticles of diameter hot-spot including nanoparticles, Positive Matrix Factorization (PMF) was applied to highly time resolved particle number size distributions (NSD, 14 nm-10 μm) and PM 0.09-1.15 chemical composition. Diurnal patterns, meteorological variables, gaseous pollutants, organic markers, and associations between the NSD factors and chemical composition factors were used to identify the pollution sources. The PMF on the NSD reveals two factors in the ultrafine size range: industrial UFPs (28%, number mode diameter - NMD 45 nm), industrial/fresh road traffic nanoparticles (26%, NMD 26 nm); three factors in the accumulation size range: urban background (24%, NMD 93 nm), coal burning (14%, volume mode diameter - VMD 0.5 μm), regional pollution (3%, VMD 0.8 μm) and one factor in the coarse size range: industrial coarse particles/road dust (2%, VMD 5 μm). The PMF analysis of PM 0.09-1.15 revealed four factors: SIA/CC/BB (52%), road dust (18%), sinter/steel (16%), iron production (16%). The factors in the ultrafine size range resolved with NSD have a positive correlation with sinter/steel production and iron production factors resolved with chemical composition. Coal combustion factor resolved with NSD has moderate correlation with SIA/CC/BB factor. The organic markers homohopanes correlate with coal combustion and the levoglucosan correlates with urban background. The PMF applications to NSD and chemical composition datasets are complementary. PAHs in PM 1 were found to be associated with coal combustion factor. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Distribution of 90Sr and 137Cs in Arctic soil profiles polluted by heavy metals

    International Nuclear Information System (INIS)

    Puhakainen, M.; Heikkinen, T.; Steinnes, E.; Thorring, H.; Outola, I.

    2005-01-01

    Effects of industrial pollution on the behaviour of radionuclides in spruce forest ecosystems were studied along a gradient from of a copper-nickel smelter in Monchegorsk, NW Russia. A reference site was situated in Lapland, Finland, 152 km west of Monchegorsk. Most of the total 137 Cs activity in soil was in mineral (E and B) horizons, except at the reference site where the major part was still in the organic surface layer. Most of the total 90 Sr activity still remaining in the soil profile was found in the surface layer, but the relative amount decreased with increasing level of industrial pollution. Pollutants from the smelter clearly affected the chemical speciation of radionuclides. Smaller amounts of exchangeable radionuclides were present in the organic surface layer at the most polluted sites. The decline of 137 Cs with decreasing distance from the smelter correlated strongly with a similar depletion in exchangeable K and Mg. Total concentrations of 137 Cs and 90 Sr showed high correlations with exchangeable cations, particularly in the E and upper B horizon. A sudden change in behaviour of 137 Cs in the lower B horizon may be associated with changes in clay mineralogy along the soil profile caused by weathering

  2. Wireless distributed environmental sensor networks for air pollution measurement-the promise and the current reality

    Czech Academy of Sciences Publication Activity Database

    Broday, D. M.; Arpaci, A.; Bartoňová, A.; Castell-Balaguer, N.; Cole-Hunter, T.; Dauge, F.R.; Fishbain, B.; Jones, R.L.; Galea, K.; Jovasevic-Stojanovic, M.; Kocman, D.; Martinez-Iniguez, T.; Nieuwenhuijsen, M.; Robinson, J.; Švecová, Vlasta; Thai, P.

    2017-01-01

    Roč. 17, č. 10 (2017), s. 2263 ISSN 1424-8220 Institutional support: RVO:68378041 Keywords : air pollution * in situ field calibration * micro sensing units Subject RIV: EI - Biotechnology ; Bionics OBOR OECD: Biomaterials (as related to medical implants, devices, sensors) Impact factor: 2.677, year: 2016

  3. [Nitrogen non-point source pollution identification based on ArcSWAT in Changle River].

    Science.gov (United States)

    Deng, Ou-Ping; Sun, Si-Yang; Lü, Jun

    2013-04-01

    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.

  4. 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, Dale 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.

  5. Footprints of Urban Micro-Pollution in Protected Areas: Investigating the Longitudinal Distribution of Perfluoroalkyl Acids in Wildlife Preserves.

    Directory of Open Access Journals (Sweden)

    Ignacio A Rodriguez-Jorquera

    Full Text Available Current approaches to protect biodiversity by establishing protected areas usually gloss over water pollution as a threat. Our objective was to determine the longitudinal and seasonal distribution of perfluoroalkyl acids (PFAAs in water column and sediments from a wastewater dominated stream that enters preservation areas. Water samples were collected along the longitudinal section (six sites, 1000 m away from each other of the stream during the dry and wet seasons. Sediments were collected from three sites along the stream from three depths. Water and sediments were analyzed for PFAAs using high performance liquid chromatography-tandem mass spectrometry. Eleven PFAAs with 5 to 14 carbon atoms were detected in the water column at all sampling points, with a minor reduction at the last point suggesting a dilution effect. The most detected PFAAs was PFOS, followed by perfluorooctanoic acid (PFOA, and perfluorohexanoic acid (PFHxA. Seasonal differences in PFAAs concentrations suggested contribution of stormwater runoff during the wet season. All analyzed PFAAs in sediments were under the limit of quantification, likely due to the high proportion of sand and low organic matter. However, high concentrations of PFAAs were detected in the water column inside the protected areas, which includes PFOS in concentrations considered not safe for avian wildlife. Water samples appear to be more relevant than sediments to determine PFAAs micro-pollution in water bodies with sandy sediments. Inclusion of a management plans on micro-pollution research, monitoring, and mitigation is recommended for protected areas.

  6. Spatial distribution and risk assessment of heavy metals and As pollution in the sediments of a shallow lake.

    Science.gov (United States)

    Deng, Jiancai; Wang, Yuansheng; Liu, Xin; Hu, Weiping; Zhu, Jinge; Zhu, Lin

    2016-05-01

    The concentrations and spatial distributions of eight heavy metals in surface sediments and sediment core samples from a shallow lake in China were investigated to evaluate the extent of the contamination and potential ecological risks. The results showed that the heavy metal concentrations were higher in the northern and southwestern lake zones than those in the other lake zones, with lower levels of As, Hg, Zn, Cu, Pb, Cr, and Ni primarily observed in the central and eastern lake regions and Cd primarily confined to areas surrounding the lake. The concentrations of the eight heavy metals in the sediment profiles tended to decrease with increasing sediment depth. The contents of Ni, Cu, Zn, Pb, and Cd in the surface sediment were approximately 1.23-18.41-fold higher than their background values (BVs), whereas the contents of Cr, As, and Hg were nearly identical to their BVs. The calculated pollution load index (PLI) suggested that the surface sediments of this lake were heavily polluted by these heavy metals and indicated that Cd was a predominant contamination factor. The comprehensive potential ecological risk index (PERI) in the surface sediments ranged from 99.2 to 2882.1, with an average of 606.1. Cd contributed 78.7 % to the PERI, and Hg contributed 8.4 %. Multivariate statistical analyses revealed that the surface sediment pollution with heavy metals mainly originated from industrial wastewater discharged by rivers located in the western and northwestern portion of the lake.

  7. Urban stormwater - greywater management system for sustainable urban water management at sub-watershed level

    Science.gov (United States)

    Singh Arora, Amarpreet

    2017-11-01

    Urban water management involves urban water supply (import, treatment and distribution of water), urban wastewater management (collection, treatment and disposal of urban sewage) and urban storm water management. Declining groundwater tables, polluted and declining sources of water, water scarcity in urban areas, unsatisfactory urban water supply and sanitation situation, pollution of receiving water bodies (including the ground water), and urban floods have become the concerns and issues of sustainable urban water management. This paper proposes a model for urban stormwater and sewage management which addresses these concerns and issues of sustainable urban water management. This model proposes segregation of the sewage into black water and greywater, and urban sub-watershed level stormwater-greywater management systems. During dry weather this system will be handling only the greywater and making the latter available as reclaimed water for reuse in place of the fresh water supply. During wet weather, the system will be taking care of (collection and treatment) both the storm water and the greywater, and the excess of the treated water will be disposed off through groundwater recharging. Application of this model in the Patiala city, Punjab, INDIA for selected urban sub-watersheds has been tried. Information and background data required for the conceptualization and design of the sub-watershed level urban stormwater-greywater management system was collected and the system has been designed for one of the sub-watersheds in the Patiala city. In this paper, the model for sustainable urban water management and the design of the Sub-watershed level Urban Stormwater-Greywater Management System are described.

  8. The effects of exercise on dose and dose distribution of inhaled automotive pollutants.

    Science.gov (United States)

    Kleinman, M T; Mautz, W J

    1991-10-01

    The purpose of this study was to determine how changes in ventilation rate and in the entry route of air pollutants into the respiratory tract (nose versus mouth breathing) affected the respiratory tract uptake and penetration of inhaled gaseous and particulate pollutants associated with automobile emissions. Experiments were performed with female beagle dogs exposed while standing at rest or while exercising on a treadmill at 5 km/hour and a 7.5 percent grade. Dogs were exposed to nitrogen dioxide at concentrations of 1 and 5 parts per million (ppm), to formaldehyde at 2 and 10 ppm, and to an aerosol of ammonium nitrate particles (0.3 micron mass median aerodynamic diameter) at 1 mg/m3. Total respiratory system uptake and effects on breath time, expired tidal volume, fractional expiration time, minute ventilation, respiratory gas exchange, ventilation equivalents for oxygen and carbon dioxide, and dynamic pulmonary resistance and compliance were measured in exercising and resting dogs exposed for two hours to 5 ppm nitrogen dioxide and 10 ppm formaldehyde in combination with 1 mg/m3 of ammonium nitrate particles. Regional penetration of pollutants through oral and nasal airways and pollutant uptake in the lung were measured in a separate group of six tracheostomized dogs standing at rest while being exposed to nitrogen dioxide, formaldehyde, and ammonium nitrate particles. Hypercapnic stimulation was used to modify ventilation rates in the tracheostomized dogs while pollutant penetration and uptake were measured. Dogs exposed to 5 ppm of nitrogen dioxide at rest tended to breathe more rapidly (p less than 0.05) and more shallowly (a nonsignificant trend) than dogs exposed to purified air. The changes observed were similar in direction, but of smaller magnitude, to changes observed when the same dogs were exposed during exercise to ozone at 0.6 ppm in a separate study. Rapid-shallow breathing was not observed when the dogs were exposed during exercise to 5 ppm

  9. Nitrogen Assessment in the Nooksack-Abbotsford-Sumas Transboundary Watershed

    Science.gov (United States)

    Lin, J.; Compton, J.; Baron, J.; Schwede, D. B.; Bittman, S.; Hooper, D. U.; Kiffney, P.; Embertson, N.; Carey, B.; MacKay, H.; Black, R.; Bahr, G.; Harrison, J.; Davidson, E. A.

    2017-12-01

    The Nooksack-Abbotsford-Sumas (NAS) Transboundary Watershed, which spans a portion of the western interface of British Columbia, Washington State, as well as the Lummi Nation and the Nooksack Tribal lands, supports agriculture, estuarine fisheries, diverse wildlife, and urban areas. Excess N has contributed to surface and ground water pollution, shellfish closure, and impaired air quality (such as haze or smog) in some areas in the watershed. The goal of this project is to determine the distribution and quantities of N fluxes of the watershed using site-specific and high-resolution data on N that originates from energy use, transportation, fertilization, wastewater treatment plants (WWTP), animal feeding and manure production, crops and more. This project is one of seven international demonstration projects contributing knowledge of regional N budgets and collaborative approaches toward N management as part of the International Nitrogen Management System (INMS). Successful N reduction relies on the partnership of all stakeholders with appropriate institutions to integrate science, outreach and management efforts. This project will bring together stakeholders on both sides of the international border for a first comprehensive, quantitative characterization of all N inventories and fluxes across this international watershed. Using crop-specific fertilizer application rates and wind-shield-survey land use data, we estimated that the annual fertilizer N input to the U.S. portion of the watershed was about 3779 metric tons (MT), which is very close to the USGS estimate of 3955 MT. Based on county level animal census data, we estimated total excretion N from major livestock (cattle) to be 7895 MT on the U.S. side. Using existing model results from other studies, we estimated that the annual N loading on the U.S. side was about 351 MT from point sources, 527 MT from atmospheric deposition, and about 7 MT from alder fixation. The preliminary results demonstrate an

  10. The response of a simulated mesoscale convective system to increased aerosol pollution: Part I: Precipitation intensity, distribution, and efficiency

    Science.gov (United States)

    Clavner, Michal; Cotton, William R.; van den Heever, Susan C.; Saleeby, Stephen M.; Pierce, Jeffery R.

    2018-01-01

    Mesoscale Convective Systems (MCSs) are important contributors to rainfall in the High Plains of the United States and elsewhere in the world. It is therefore of interest to understand how different aerosols serving as cloud condensation nuclei (CCN) may impact the total amount, rates and spatial distribution of precipitation produced by MCSs. In this study, different aerosol concentrations and their effects on precipitation produced by an MCS are examined by simulating the 8 May 2009 "Super-Derecho" MCS using the Regional Atmospheric Modeling System (RAMS), a cloud-resolving model (CRM) with sophisticated aerosol and microphysical parameterizations. Three simulations were conducted that differed only in the initial concentration, spatial distribution, and chemical composition of aerosols. Aerosol fields were derived from the output of GEOS-Chem, a 3D chemical transport numerical model. Results from the RAMS simulations show that the total domain precipitation was not significantly affected by variations in aerosol concentrations, however, the pollution aerosols altered the precipitation characteristics. The more polluted simulations exhibited higher precipitation rates, higher bulk precipitation efficiency, a larger area with heavier precipitation, and a smaller area with lighter precipitation. These differences arose as a result of aerosols enhancing precipitation in the convective region of the MCS while suppressing precipitation from the MCS's stratiform-anvil. In the convective region, several processes likely contributed to an increase of precipitation. First, owing to the very humid environment of this storm, the enhanced amount of cloud water available to be collected overwhelmed the reduction in precipitation efficiency associated with the aerosol-induced production of smaller droplets which led to a net increase in the conversion of cloud droplets to precipitation. Second, higher aerosol concentrations led to invigoration of convective updrafts which

  11. Comparison Study on the Estimation of the Spatial Distribution of Regional Soil Metal(loids Pollution Based on Kriging Interpolation and BP Neural Network

    Directory of Open Access Journals (Sweden)

    Zhenyi Jia

    2017-12-01

    Full Text Available Soil pollution by metal(loids resulting from rapid economic development is a major concern. Accurately estimating the spatial distribution of soil metal(loid pollution has great significance in preventing and controlling soil pollution. In this study, 126 topsoil samples were collected in Kunshan City and the geo-accumulation index was selected as a pollution index. We used Kriging interpolation and BP neural network methods to estimate the spatial distribution of arsenic (As and cadmium (Cd pollution in the study area. Additionally, we introduced a cross-validation method to measure the errors of the estimation results by the two interpolation methods and discussed the accuracy of the information contained in the estimation results. The conclusions are as follows: data distribution characteristics, spatial variability, and mean square errors (MSE of the different methods showed large differences. Estimation results from BP neural network models have a higher accuracy, the MSE of As and Cd are 0.0661 and 0.1743, respectively. However, the interpolation results show significant skewed distribution, and spatial autocorrelation is strong. Using Kriging interpolation, the MSE of As and Cd are 0.0804 and 0.2983, respectively. The estimation results have poorer accuracy. Combining the two methods can improve the accuracy of the Kriging interpolation and more comprehensively represent the spatial distribution characteristics of metal(loids in regional soil. The study may provide a scientific basis and technical support for the regulation of soil metal(loid pollution.

  12. Comparison Study on the Estimation of the Spatial Distribution of Regional Soil Metal(loid)s Pollution Based on Kriging Interpolation and BP Neural Network.

    Science.gov (United States)

    Jia, Zhenyi; Zhou, Shenglu; Su, Quanlong; Yi, Haomin; Wang, Junxiao

    2017-12-26

    Soil pollution by metal(loid)s resulting from rapid economic development is a major concern. Accurately estimating the spatial distribution of soil metal(loid) pollution has great significance in preventing and controlling soil pollution. In this study, 126 topsoil samples were collected in Kunshan City and the geo-accumulation index was selected as a pollution index. We used Kriging interpolation and BP neural network methods to estimate the spatial distribution of arsenic (As) and cadmium (Cd) pollution in the study area. Additionally, we introduced a cross-validation method to measure the errors of the estimation results by the two interpolation methods and discussed the accuracy of the information contained in the estimation results. The conclusions are as follows: data distribution characteristics, spatial variability, and mean square errors (MSE) of the different methods showed large differences. Estimation results from BP neural network models have a higher accuracy, the MSE of As and Cd are 0.0661 and 0.1743, respectively. However, the interpolation results show significant skewed distribution, and spatial autocorrelation is strong. Using Kriging interpolation, the MSE of As and Cd are 0.0804 and 0.2983, respectively. The estimation results have poorer accuracy. Combining the two methods can improve the accuracy of the Kriging interpolation and more comprehensively represent the spatial distribution characteristics of metal(loid)s in regional soil. The study may provide a scientific basis and technical support for the regulation of soil metal(loid) pollution.

  13. [Distribution and Pollution Assessment of Nutrient and Heavy Metals in Surface Sediments from Lake Gehu in Southern Jiangsu Province, China].

    Science.gov (United States)

    Xiong, Chun-hui; Zhagn, Rui-lei; Wu, Xiao-dong; Feng, Li-hui; Wang, Li-qing

    2016-03-15

    This study investigated the horizontal distribution characteristics of nutrients and heavy metals (Zn, As, Cr, Cu, Ni, Pb, Cd and Hg) in January, 2014, and assessed the potential ecological risk of Lake Gehu. It was found that the average contents of TN and TP were 2,207.94 and 708.62 mg · kg⁻¹ respectively. TN and TP contents of the sediments at the centre were significantly highei than those in the north, while the TN content in the south was also significantly higher than that in the north of Lake Gehu. The average contents of Zn, As, Cr, Cu, Ni, Pb, Cd, Hg were 766.59, 350.66, 307.98, 59.54, 122.67, 168.97, 2.34, 0.41 mg · kg⁻¹, respectively. The content of Cu at the centre was significantly higher than that in the north, and the Zn content at the centre was significantly greater than that in the south of Lake Gehu, however the difference in the content of other heavy metals at these three areas was not significant. Furthermore, the obvious correlation between elements and granularity was only found in the aspect of TP, Cu and Hg. The comprehensive pollution index (PI) indicated that the Lake Gehu was heavily polluted, especially the centre and south areas. The potential ecological risk index (RI) showed that Cd, As and Hg had caused serious pollution in Lake Gehu while the other heavy metals only induced slight or medium pollution. According to the contribution of Cd, As and Hg to RI, it was concluded that the sediments in Lake Gehu were at a serious potential ecological risk.

  14. Adopt Your Watershed

    Data.gov (United States)

    U.S. Environmental Protection Agency — Adopt Your Watershed is a Website that encourages stewardship of the nation's water resources and serves as a national inventory of local watershed groups and...

  15. Channel bed particle size distribution procedure used to evaluate watershed cumulative effects for range permit re-issuance on the Santa Fe National Forest

    Science.gov (United States)

    Bruce Sims; Jim Piatt; Lee Johnson; Carol Purchase; John Phillips

    1996-01-01

    Personnel on the Santa Fe National Forest used methodologies adapted from Bevenger and King (1995) to collect base line particle size data on streams within grazing allotments currently scheduled for permit reissuance. This information was used to determine the relative current health of the watersheds as well as being used in the development of potential alternatives...

  16. Distribution of persistent organic pollutants and trace metals in surface waters in the Seversky Donets River basin (Eastern Ukraine)

    Science.gov (United States)

    Diadin, Dmytro; Celle-Jeanton, Hélène; Steinmann, Marc; Loup, Christophe; Crini, Nadia; Vystavna, Yuliya; Vergeles, Yuri; Huneau, Frédéric

    2017-04-01

    The paper is focused on surface water of the Seversky Donets River Basin in Eastern Ukraine which undergoes significant anthropogenic pressure due to municipal and industrial wastewater discharge, polluted runoff from both urban and agricultural areas, leakages at oil-gas extraction sites located in the region. In these conditions the Seversky Donets River is used for drinking water supply of the city of Kharkiv with 1.5 million inhabitants as well as other smaller settlements in the basin. The diversity of water pollution sources makes it reasonable to use complex indicators and assessment approaches such as combination of organic and inorganic pollutants. We have studied the distribution of major ions, metals and persistent organic compounds (PAHs and PCBs) in water of the Seversky Donets River and its tributaries. In total 20 sites have been sampled on the river catchment area as of 4.5 thousands km2. PAHs and PCBs were measured in surface water for the first time in the region. The most distinctive transformations of water composition have been found downstream wastewater treatment plants in the city of Kharkiv where treated mixture of municipal and industrial wastewater is discharged to the river. Such metals as Ni, Zn, Cr in combination with phosphates and nitrates has shown significant positive correlation indicating the common source of their input. Ten of sixteen total PAHs were detected in measurable concentrations in at least one sample of river water. Sum of PAHs ranged from 15.3 to 117.2 ng/L with mean of 43.8 ng/L. The ratios of PAHs have indicated rather pyrogenic than petrogenic inputs on all the studied sites. Elevated concentrations of low molecular weight PAHs in water were found close to a coal-burning power station and a coke chemical plant also confirming their origin from coal combustion and subsequent atmospheric deposition. PCBs distribution has appeared to be relatively uniform on the territory despite the vast area of the basin researched

  17. Air pollution exposure during critical time periods in gestation and alterations in cord blood lymphocyte distribution: a cohort of livebirths

    Directory of Open Access Journals (Sweden)

    Herr Caroline EW

    2010-08-01

    Full Text Available Abstract Background Toxic exposures have been shown to influence maturation of the immune system during gestation. This study investigates the association between cord blood lymphocyte proportions and maternal exposure to air pollution during each gestational month. Methods Cord blood was analyzed using a FACSort flow cytometer to determine proportions of T lymphocytes (CD3+ cells and their subsets, CD4+ and CD8+, B lymphocytes (CD19+ and natural killer (NK cells. Ambient air concentrations of 12 polycyclic aromatic hydrocarbons (PAH and particulate matter 2.5 were measured using fixed site monitors. Arithmetic means of these pollutants, calculated for each gestational month, were used as exposure metrics. Data on covariates were obtained from medical records and questionnaires. Multivariable linear regression models were fitted to estimate associations between monthly PAH or PM2.5 and cord blood lymphocytes, adjusting for year of birth and district of residence and, in further models, gestational season and number of prior live births. Results The adjusted models show significant associations between PAHs or PM2.5 during early gestation and increases in CD3+ and CD4+ lymphocytes percentages and decreases in CD19+ and NK cell percentages in cord blood. In contrast, exposures during late gestation were associated with decreases in CD3+ and CD4+ fractions and increases in CD19+ and NK cell fractions. There was no significant association between alterations in lymphocyte distribution and air pollution exposure during the mid gestation. Conclusions PAHs and PM2.5 in ambient air may influence fetal immune development via shifts in cord blood lymphocytes distributions. Associations appear to differ by exposure in early versus late gestation.

  18. Morphology, chemistry and distribution of neoformed spherulites in agricultural land affected by metallurgical point-source pollution

    Energy Technology Data Exchange (ETDEWEB)

    Leguedois, Sophie; Oort, Folkert van; Jongmans, Toine; Chevallier, Pierre

    2004-07-01

    Metal distribution patterns in superficial soil horizons of agricultural land affected by metallurgical point-source pollution were studied using optical and electron microscopy, synchrotron radiation and spectroscopy analyses. The site is located in northern France, at the center of a former entry lane to a bunker of World War II, temporarily paved with coarse industrial waste fragments and removed at the end of the war. Thin sections made from undisturbed soil samples from A and B horizons were studied. Optical microscopy revealed the occurrence of yellow micrometer-sized (Ap horizon) and red decamicrometer-sized spherulites (AB, B{sub 1}g horizons) as well as distinct distribution patterns. The chemical composition of the spherulites was dominated by Fe, Mn, Zn, Pb, Ca, and P. Comparison of calculated Zn stocks, both in the groundmass and in spherulites, showed a quasi-exclusive Zn accumulation in these neoformed features. Their formation was related to several factors: (i) liberation of metal elements due to weathering of waste products, (ii) Ca and P supply from fertilizing practices, (iii) co-precipitation of metal elements and Ca and P in a porous soil environment, after slow exudation of a supersaturated soil solution in more confined mineral media. - Metal spherulites may act as high metal-trapping mineral phases in polluted agricultural soils.

  19. Distribution in Portugal of some pollutants in the lichen Parmelia sulcata.

    Science.gov (United States)

    Freitas, M C; Reis, M A; Alves, L C; Wolterbeek, H T

    1999-08-01

    During the months of July and August 1993 a lichen (Parmelia sulcata Taylor) collection campaign was held in Portugal where samples were obtained from olive tree bark at 228 sites, following a grid of 10 x 10 km along the Atlantic coast and 50 x 50 km in the interior of the country. The samples were analysed by instrumental neutron activation analysis and proton induced X-ray emission techniques. Concentration data patterns for the pollutants As, Cr, Hg, Ni, Pb, S, Sb, Se, and V were obtained for the whole country surface by making use of an extinction rule of 1/r(3), preventing any cut-off distance from being artificially introduced. Some pollution sources were identified: (1) oil-powered plants on the Lisbon-Setúbal axis (V, Ni), (2) coal-power plants in Porto and Sines (S, Se), (3) traffic in the northern area and the Lisbon-Setúbal axis (Pb), (4) a chemical industry south of Porto (Hg, As), and (5) soil influence (Cr, Sb). Arsenic and chromium results largely exceed, in a few areas, the concentrations acceptable to plants, and in a few spots also Hg, Ni, and Pb data.

  20. Flood Frequency Analysis of Future Climate Projections in the Cache Creek Watershed

    Science.gov (United States)

    Fischer, I.; Trihn, T.; Ishida, K.; Jang, S.; Kavvas, E.; Kavvas, M. L.

    2014-12-01

    Effects of climate change on hydrologic flow regimes, particularly extreme events, necessitate modeling of future flows to best inform water resources management. Future flow projections may be modeled through the joint use of carbon emission scenarios, general circulation models and watershed models. This research effort ran 13 simulations for carbon emission scenarios (taken from the A1, A2 and B1 families) over the 21st century (2001-2100) for the Cache Creek watershed in Northern California. Atmospheric data from general circulation models, CCSM3 and ECHAM5, were dynamically downscaled to a 9 km resolution using MM5, a regional mesoscale model, before being input into the physically based watershed environmental hydrology (WEHY) model. Ensemble mean and standard deviation of simulated flows describe the expected hydrologic system response. Frequency histograms and cumulative distribution functions characterize the range of hydrologic responses that may occur. The modeled flow results comprise a dataset suitable for time series and frequency analysis allowing for more robust system characterization, including indices such as the 100 year flood return period. These results are significant for water quality management as the Cache Creek watershed is severely impacted by mercury pollution from historic mining activities. Extreme flow events control mercury fate and transport affecting the downstream water bodies of the Sacramento River and Sacramento- San Joaquin Delta which provide drinking water to over 25 million people.

  1. Development of a Prototype Web-Based Decision Support System for Watershed Management

    Directory of Open Access Journals (Sweden)

    Dejian Zhang

    2015-02-01

    Full Text Available Using distributed hydrological models to evaluate the effectiveness of reducing non-point source pollution by applying best management practices (BMPs is an important support to decision making for watershed management. However, complex interfaces and time-consuming simulations of the models have largely hindered the applications of these models. We designed and developed a prototype web-based decision support system for watershed management (DSS-WMRJ, which is user friendly and supports quasi-real-time decision making. DSS-WMRJ is based on integrating an open-source Web-based Geographical Information Systems (Web GIS tool (Geoserver, a modeling component (SWAT, Soil and Water Assessment Tool, a cloud computing platform (Hadoop and other open source components and libraries. In addition, a private cloud is used in an innovative manner to parallelize model simulations, which are time consuming and computationally costly. Then, the prototype DSS-WMRJ was tested with a case study. Successful implementation and testing of the prototype DSS-WMRJ lay a good foundation to develop DSS-WMRJ into a fully-fledged tool for watershed management. DSS-WMRJ can be easily customized for use in other watersheds and is valuable for constructing other environmental decision support systems, because of its performance, flexibility, scalability and economy.

  2. 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.

  3. Distribution of copepods from the polluted and unpolluted regions off Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; JiyalalRam, M.J.; Desai, B.N.

    Distribution and abundance of copepods in the nearshore waters off Bombay were studied at 4 fixed sampling sites during October 1977 to December 1978.The stations Mahim and Thana received domestic and industrial waste while the stations of Versova...

  4. Distributions of air pollutants associated with oil and natural gas development measured in the Upper Green River Basin of Wyoming

    Directory of Open Access Journals (Sweden)

    R.A. Field

    2015-10-01

    Full Text Available Abstract Diffusive sampler monitoring techniques were employed during wintertime studies from 2009 to 2012 to assess the spatial distribution of air pollutants associated with the Pinedale Anticline and Jonah Field oil and natural gas (O&NG developments in the Upper Green River Basin, Wyoming. Diffusive sampling identified both the extent of wintertime ozone (O3 episodes and the distributions of oxides of nitrogen (NOx, and a suite of 13 C5+ volatile organic compounds (VOC, including BTEX (benzene, toluene, ethylbenzene and xylene isomers, allowing the influence of different O&NG emission sources to be determined. Concentration isopleth mapping of both diffusive sampler and continuous O3 measurements show the importance of localized production and advective transport. As for O3, BTEX and NOx mixing ratios within O&NG development areas were elevated compared to background levels, with localized hotspots also evident. One BTEX hotspot was related to an area with intensive production activities, while a second was located in an area influenced by emissions from a water treatment and recycling facility. Contrastingly, NOx hotspots were at major road intersections with relatively high traffic flows, indicating influence from vehicular emissions. Comparisons of observed selected VOC species ratios at a roadside site in the town of Pinedale with those measured in O&NG development areas show that traffic emissions contribute minimally to VOCs in these latter areas. The spatial distributions of pollutant concentrations identified by diffusive sampling techniques have potential utility for validation of emission inventories that are combined with air quality modeling.

  5. Grain size distribution of road-deposited sediment and its contribution to heavy metal pollution in urban runoff in Beijing, China.

    Science.gov (United States)

    Zhao, Hongtao; Li, Xuyong; Wang, Xiaomei; Tian, Di

    2010-11-15

    Pollutant washoff from road-deposited sediment (RDS) is an increasing problem associated with the rapid urbanization of China that results in urban non-point source pollution. Here, we analyzed the RDS grain size distribution and its potential impact on heavy metal pollution in urban runoff from impervious surfaces of urban villages, colleges and residences, and main traffic roads in the Haidian District, Beijing, China. RDS with smaller grain size had a higher metal concentration. Specifically, particles with the smallest grain size (runoff water accounted for greater than 70% of the metal mass in the total suspended solids (TSS). The heavy metal content in the TSS was 2.21-6.52% of that in the RDS. These findings will facilitate our understanding of the importance of RDS grain size distribution in heavy metal pollution caused by urban storm runoff. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Reduction Assessment of Agricultural Non-Point Source Pollutant Loading

    OpenAIRE

    Fu, YiCheng; Zang, Wenbin; Zhang, Jian; Wang, Hongtao; Zhang, Chunling; Shi, Wanli

    2018-01-01

    NPS (Non-point source) pollution has become a key impact element to watershed environment at present. With the development of technology, application of models to control NPS pollution has become a very common practice for resource management and Pollutant reduction control in the watershed scale of China. The SWAT (Soil and Water Assessment Tool) model is a semi-conceptual model, which was put forward to estimate pollutant production & the influences on water quantity-quality under different...

  7. [Distribution patterns and pollution assessments of heavy metals in the Spartina alterniflora salt-marsh wetland of Rudong, Jiangsu province].

    Science.gov (United States)

    Zhang, Long-Hui; Du, Yong-Fen; Wang, Dan-Dan; Gao, Shu; Gao, Wen-Hua

    2014-06-01

    To understand the ecological impact of Spartina alterniflora on the coastal wetland environment, field survey was carried out in July, 2010, over the intertidal areas of Rudong coast, Jiangsu province; sediment samples were collected from a series of stations with different conditions of vegetation cover and S. alterniflora growth. The contents of eight heavy metals, together with sediment composition and total organic carbon were analyzed to reveal the distribution patterns of the heavy metals. Environmental quality status was evaluated using both the index of geoaccumulation (I(geo)) and the index of the Håkanson ecological risk. The analytical results showed that the average contents of Pb, Cd, As, Hg, Cr, Cu, Ni and Zn were below the standard for the Category I sediment quality, among which Cd, Hg, Ni and Zn exceeded the sediment background value of the region. On the whole, the contents of eight heavy metals in vegetation areas were higher than those associated with the adjacent bare flat areas. These data sets indicate a non-polluted condition in term of I(geo) estimation; however, a critical state of low to moderate degrees of pollution and a low level of risk were deduced according to the index of the Håkanson potential ecological risk. Both indices suggested that the pollution level of Hg and Cd were the highest among the eight metals measured. Along the transection from seaward to landward, the contents of As, Cu and Hg, their indices of I(geo) and Håkanson ecological risk all showed an increasing tread, in accordance with the condition of vegetation cover. Along the coastline with S. alterniflora being distributed in patchiness, all metal contents and their ecological risk level values for the marshes were higher than those for the unvegetated sediments nearby; moreover, except for Hg, other seven metals exhibited relatively low values than those in the shore-normal section with a better S. alterniflora growth. These findings indicate that S

  8. Persistent organic pollutants in the Tibetan surface soil: Spatial distribution, air–soil exchange and implications for global cycling

    International Nuclear Information System (INIS)

    Wang Xiaoping; Sheng Jiujiang; Gong Ping; Xue Yonggang; Yao Tandong; Jones, Kevin C.

    2012-01-01

    There are limited data on persistent organic pollutants (POPs) in the soils of the Tibetan Plateau. This paper presents data from a survey of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in 40 background surface (0–5 cm) soils of the Tibetan Plateau. Soil concentrations (pg/g, dw) ranged as follows: DDTs, 13-7700; HCHs, 64-847; HCB, 24-564; sum of 15 PCBs, 75-1021; and sum of 9 PBDEs, below detection limit −27. Soil DDT, HCB, PCB and PBDE concentrations were strongly influenced by soil organic carbon content. HCH concentrations were clearly associated with the proximity to source regions in south Asia. The air–soil equilibrium status of POPs suggested the Tibetan soils may be partial “secondary sources” of HCB, low molecular weight PCBs and HCHs and will likely continue to be “sinks” for the less volatile DDE and DDT. - Highlights: ► Soil organic carbon content influence the spatial distribution of persistent organic pollutants. ► The Tibetan soil acts as “secondary sources” for HCB, low molecular weight PCBs and HCHs. ► The Tibetan soil will continue to be “sinks” for DDE and DDT. - Tibetan soils may be potential “secondary sources” of the HCB, low molecular weight PCBs and HCHs that are observed in air.

  9. Distribution of sewage pollution around a maritime Antarctic research station indicated by faecal coliforms, Clostridium perfringens and faecal sterol markers

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Kevin A.; Thompson, Anu

    2004-02-01

    This study describes the distribution of sewage pollution markers (faecal coliforms, Clostridium perfringens and faecal sterols) in seawater and marine sediments around Rothera Research Station, Antarctic Peninsula. Untreated sewage waste has been released from this site since 1975, creating the potential for long-term contamination of the benthic environment. Faecal coliform concentrations in seawater reached background levels within 300 m of the outfall. In sediment cores, both C. perfringens and faecal coliform concentrations declined with distance from the outfall, though C. perfringens persisted at greater depths in the sediment. High concentrations of 5{beta}(H)-cholestan-3{beta}-ol (coprostanol) relative to the corresponding 5{alpha}-epimer (cholestanol), indicative of sewage pollution, were only found in sediments within 200 m of the sewage outfall. This study has shown that sewage contamination is limited to the immediate vicinity of the sewage outfall. Nevertheless, a sewage treatment plant was installed in February 2003 to reduce this contamination further. - Sewage contamination of seawater and marine sediments near Rothera Research Station (Antarctic Peninsula) was limited to the immediate vicinity of the outfall.

  10. Pollution level, phase distribution and health risk of polycyclic aromatic hydrocarbons in indoor air at public places of Hangzhou, China

    International Nuclear Information System (INIS)

    Lu Hao; Zhu Lizhong; Chen Shuguang

    2008-01-01

    PAHs pollution survey in air of public places was conducted in Hangzhou, China. The most serious PAHs pollution was observed in indoor air of shopping centers and the slightest was in train stations. The molecular weight of chrysene (MW 228) appeared to be the dividing line for the PAHs with a larger or smaller distribution in the vapor or particulate phase. Concentrations of 15 PAHs on PM 2.5 accounted for 71.3% of total particulate PAHs, and followed by PM 2.5-10 fraction (17.6%) and >PM 10 fraction (11.1%). In shopping centers and supermarkets, emission of 2-4 rings PAHs occurred from indoor sources, whereas 5-6 rings PAHs predominantly originated from transport of outdoor air. In temples, PAHs in indoor air mainly originated from incense burning. Health risks associated with the inhalation of PAHs were assessed, and naphthalene made the greatest contribution (62.4%) to the total health risks. - Concentrations of PAHs in the air of selected public places in Hangzhou correspond to 10 -3 life-time lung cancer risk

  11. Distribution of sewage pollution around a maritime Antarctic research station indicated by faecal coliforms, Clostridium perfringens and faecal sterol markers

    International Nuclear Information System (INIS)

    Hughes, Kevin A.; Thompson, Anu

    2004-01-01

    This study describes the distribution of sewage pollution markers (faecal coliforms, Clostridium perfringens and faecal sterols) in seawater and marine sediments around Rothera Research Station, Antarctic Peninsula. Untreated sewage waste has been released from this site since 1975, creating the potential for long-term contamination of the benthic environment. Faecal coliform concentrations in seawater reached background levels within 300 m of the outfall. In sediment cores, both C. perfringens and faecal coliform concentrations declined with distance from the outfall, though C. perfringens persisted at greater depths in the sediment. High concentrations of 5β(H)-cholestan-3β-ol (coprostanol) relative to the corresponding 5α-epimer (cholestanol), indicative of sewage pollution, were only found in sediments within 200 m of the sewage outfall. This study has shown that sewage contamination is limited to the immediate vicinity of the sewage outfall. Nevertheless, a sewage treatment plant was installed in February 2003 to reduce this contamination further. - Sewage contamination of seawater and marine sediments near Rothera Research Station (Antarctic Peninsula) was limited to the immediate vicinity of the outfall

  12. Spatial Interpolation of Aerosol Optical Depth Pollution: Comparison of Methods for the Development of Aerosol Distribution

    Science.gov (United States)

    Safarpour, S.; Abdullah, K.; Lim, H. S.; Dadras, M.

    2017-09-01

    Air pollution is a growing problem arising from domestic heating, high density of vehicle traffic, electricity production, and expanding commercial and industrial activities, all increasing in parallel with urban population. Monitoring and forecasting of air quality parameters are important due to health impact. One widely available metric of aerosol abundance is the aerosol optical depth (AOD). The AOD is the integrated light extinction coefficient over a vertical atmospheric column of unit cross section, which represents the extent to which the aerosols in that vertical profile prevent the transmission of light by absorption or scattering. Seasonal aerosol optical depth (AOD) values at 550 nm derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard NASA's Terra satellites, for the 10 years period of 2000 - 2010 were used to test 7 different spatial interpolation methods in the present study. The accuracy of estimations was assessed through visual analysis as well as independent validation based on basic statistics, such as root mean square error (RMSE) and correlation coefficient. Based on the RMSE and R values of predictions made using measured values from 2000 to 2010, Radial Basis Functions (RBFs) yielded the best results for spring, summer and winter and ordinary kriging yielded the best results for fall.

  13. Levels and Distribution of Pollutants in the Waters of an Aquatic Ecosystem in Northern Mexico

    Directory of Open Access Journals (Sweden)

    Jesús Manuel Ochoa-Rivero

    2017-04-01

    Full Text Available The availability of good quality water resources is essential to ensure healthy crops and livestock. The objective of this study was to evaluate the level of pollution in Bustillos Lagoon in northern Mexico. Physical-chemical parameters like sodium, chloride, sulfate, electrical conductivity, nitrates, and the pesticide dichlorodiphenyltrichloroethane (DDT were analyzed to determine the water quality available in the lagoon. Although DDT has been banned in several countries, it is still used for agricultural purposes in Mexico and its presence in this area had not been analyzed previously. Bustillos Lagoon was divided into three zones for the evaluation: (1 industrial; (2 communal lands; and (3 agricultural. The highest concentrations of sodium (2360 mg/L and SAR (41 meq/L reported in the industrial zone are values exceeding the United Nations Food and Agricultural Organization (FAO irrigation water quality guidelines. DDT and its metabolites were detected in all of the 21 sites analyzed, in the agricultural zone ∑DDTs = 2804 ng/mL, this level is much higher than those reported for other water bodies in Mexico and around the world where DDT has been used heavily. The water in the communal zone is the least contaminated, but can only be recommended for irrigation of plants with high stress tolerance and not for crops.

  14. Levels and Distribution of Pollutants in the Waters of an Aquatic Ecosystem in Northern Mexico.

    Science.gov (United States)

    Ochoa-Rivero, Jesús Manuel; Reyes-Fierro, Ana Victoria; Peralta-Pérez, Ma Del Rosario; Zavala-Díaz de la Serna, Francisco Javier; Ballinas-Casarrubias, Lourdes; Salmerón, Ivan; Rubio-Arias, Héctor; Rocha-Gutiérrez, Beatriz A

    2017-04-25

    The availability of good quality water resources is essential to ensure healthy crops and livestock. The objective of this study was to evaluate the level of pollution in Bustillos Lagoon in northern Mexico. Physical-chemical parameters like sodium, chloride, sulfate, electrical conductivity, nitrates, and the pesticide dichlorodiphenyltrichloroethane (DDT) were analyzed to determine the water quality available in the lagoon. Although DDT has been banned in several countries, it is still used for agricultural purposes in Mexico and its presence in this area had not been analyzed previously. Bustillos Lagoon was divided into three zones for the evaluation: (1) industrial; (2) communal lands; and (3) agricultural. The highest concentrations of sodium (2360 mg/L) and SAR (41 meq/L) reported in the industrial zone are values exceeding the United Nations Food and Agricultural Organization (FAO) irrigation water quality guidelines. DDT and its metabolites were detected in all of the 21 sites analyzed, in the agricultural zone ∑DDTs = 2804 ng/mL, this level is much higher than those reported for other water bodies in Mexico and around the world where DDT has been used heavily. The water in the communal zone is the least contaminated, but can only be recommended for irrigation of plants with high stress tolerance and not for crops.

  15. SPATIAL INTERPOLATION OF AEROSOL OPTICAL DEPTH POLLUTION: COMPARISON OF METHODS FOR THE DEVELOPMENT OF AEROSOL DISTRIBUTION

    Directory of Open Access Journals (Sweden)

    S. Safarpour

    2017-09-01

    Full Text Available Air pollution is a growing problem arising from domestic heating, high density of vehicle traffic, electricity production, and expanding commercial and industrial activities, all increasing in parallel with urban population. Monitoring and forecasting of air quality parameters are important due to health impact. One widely available metric of aerosol abundance is the aerosol optical depth (AOD. The AOD is the integrated light extinction coefficient over a vertical atmospheric column of unit cross section, which represents the extent to which the aerosols in that vertical profile prevent the transmission of light by absorption or scattering. Seasonal aerosol optical depth (AOD values at 550 nm derived from the Moderate Resolution Imaging Spectroradiometer (MODIS sensor onboard NASA’s Terra satellites, for the 10 years period of 2000 - 2010 were used to test 7 different spatial interpolation methods in the present study. The accuracy of estimations was assessed through visual analysis as well as independent validation based on basic statistics, such as root mean square error (RMSE and correlation coefficient. Based on the RMSE and R values of predictions made using measured values from 2000 to 2010, Radial Basis Functions (RBFs yielded the best results for spring, summer and winter and ordinary kriging yielded the best results for fall.

  16. Geographical distribution and risk assessment of persistent organic pollutants in golden threads (Nemipterus virgatus) from the northern South China Sea.

    Science.gov (United States)

    Hao, Qing; Sun, Yu-Xin; Xu, Xiang-Rong; Yao, Zi-Wei; Wang, You-Shao; Zhang, Zai-Wang; Luo, Xiao-Jun; Mai, Bi-Xian

    2015-10-01

    Fish are often used as good bioindicators to monitor the occurrence of persistent organic pollutants (POPs) on different scales in recent years. Forty-five golden threads (Nemipterus virgatus) were collected from six sampling sites in the northern South China Sea (SCS) to investigate the geographical distribution of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). Concentrations of PBDEs, PCBs, and DDTs ranged from 1.3-36.0, 2.3-76.5, 8.3-228 ng/g lipid weight, respectively. The highest PBDEs and DDTs concentrations were found in golden threads from Shantou, owing to the intensive electronic waste recycling activities and rapid development of agriculture. Samples from Haikou had the highest levels of PCBs, probably due to the existence of many shipbuilding yards in the past years. The concentrations of PBDEs and PCBs were found in a decreasing trend from east to west and from north to south, while DDTs concentrations had no obvious trend in the distribution. PCBs were the most prevalent contaminants in Xiamen and Yangjiang, while DDTs were the dominant compounds at the other four sampling sites. Different profiles of POPs at each sampling site may attribute to different pollution sources in the northern SCS. Ratios of (DDD + DDE)/DDTs in golden threads suggested the probability of fresh input of DDT in the northern SCS. The estimated daily intakes of PBDEs, PCBs and DDTs were 0.030-0.069, 0.167-0.258 and 0.105-1.88 ng/kg/day, respectively, which were significantly lower than the acceptable daily intake, suggesting that consumption of golden threads from the northern SCS would not subject the residents in the coastal areas of SCS to significant health risk.

  17. Spatial distribution of bottlenose dolphins (Tursiops truncatus) inferred from stable isotopes and priority organic pollutants

    International Nuclear Information System (INIS)

    Wilson, Rachel Marie; Kucklick, John R.; Balmer, Brian C.; Wells, Randall S.; Chanton, Jeffrey P.; Nowacek, Douglas P.

    2012-01-01

    Differences in priority organic pollutants (POPs), analyzed by gas chromatography-mass spectrometry, and stable isotope ratios (δ 13 C, δ 34 S, and δ 15 N; analyzed by isotope ratio-mass spectrometry), divide 77 bottlenose dolphins (Tursiops truncatus) from the Florida Gulf Coast into three distinct groups. POP levels reflect human population and historical contamination along the coast. In the least disturbed site, concentrations of ΣPOP in male dolphins were 18,000 ng g −1 ± 6000 (95% confidence interval here and throughout); in the intermediate bay, males had ΣPOP concentrations of 19,000 ng g −1 ± 10,000. St Andrews Bay was home to dolphins with the highest ΣPOP concentrations: 44,000 ng g −1 ± 10,300. δ 34 S and δ 15 N, differed significantly between St. George Sound dolphins and those frequenting each of the other two bays, but not between St. Andrews and St. Joseph Bays. ΣPOP concentrations were statistically higher in dolphins frequenting St. Andrews Bay, but were not significantly different between dolphins occupying St. Joseph Bay and St. George Sound. Thus, using either POP or isotope values alone, we would only be able to identify two dolphin groups, but when POP and isotope data are viewed cumulatively, the results clearly define three distinct communities occupying this region. - Highlights: ► We compare isotopes and POP levels in dolphins occupying three embayments. ► POP levels varied significantly among two embayments separated by < 50 km. ► Differentiation correlated with historical contamination from a SuperFund site. ► Cumulatively, isotopes and POP levels indicate 3 distinct dolphin communities. ► This data provides the first assessment of dolphin POP contamination in the region.

  18. The Distribution and Environmental Impacts of Noise Pollution Sadouqi Martyr Yazd International Airport Using GIS

    Directory of Open Access Journals (Sweden)

    H Zarei Mahmoud Abadi

    2016-03-01

    Full Text Available Introduction: Persecutors of aircraft noise at an airport has a close relationship with the alternate of landing and take-off weight of the aircraft and operations planning during the night. Now aircraft that spill in Yazd airport and take-off of aircraft is of jet engines or so-turbofan mean that the resulting sound will be very high. Methods: In this descriptive, cross-sectional  measurement of noise from aircraft traffic noise measuring station 7,The completed questionnaires to assess the effects of noise pollution in Yazd International Airport and the surrounding noise sensitive areas in 2014 by a portable audio device measurement is done. Results: The most amount of noise caused by aircraft traffic in the airport area and in adjacent areas with average noise level 84.8 dB at station No. 5 Regional Airport, located south of the airport, with an average noise level which was 75.5 dB. The results of analysis of questionnaires showed that 75 percent of people living in residential areas around the airport are being harassed by aircraft noise. Results indicate that, sleep disorders, nervousness, stress and mental illness and interfere with speech, regardless of the priority of different factors in the study area, are of the highest impact of aircraft noise. Conclusion: Aircraft noise is the strongest negative environmental factors that affect employees and residents around Yazd International Airport and can be harmful to health. The noise for health personnel, particularly those of daily tasks, are daily exposed to aircraft intense noise , are highly undesirable. So, essentially preventive severe conditions such as mandatory use of protective devices and soundproof acoustic shortening service personnel are needed for these people.

  19. Modelling the fate of persistent organic pollutants in Europe: parameterisation of a gridded distribution model

    International Nuclear Information System (INIS)

    Prevedouros, Konstantinos; MacLeod, Matthew; Jones, Kevin C.; Sweetman, Andrew J.

    2004-01-01

    A regionally segmented multimedia fate model for the European continent is described together with an illustrative steady-state case study examining the fate of γ-HCH (lindane) based on 1998 emission data. The study builds on the regionally segmented BETR North America model structure and describes the regional segmentation and parameterisation for Europe. The European continent is described by a 5 deg. x 5 deg. grid, leading to 50 regions together with four perimetric boxes representing regions buffering the European environment. Each zone comprises seven compartments including; upper and lower atmosphere, soil, vegetation, fresh water and sediment and coastal water. Inter-regions flows of air and water are described, exploiting information originating from GIS databases and other georeferenced data. The model is primarily designed to describe the fate of Persistent Organic Pollutants (POPs) within the European environment by examining chemical partitioning and degradation in each region, and inter-region transport either under steady-state conditions or fully dynamically. A test case scenario is presented which examines the fate of estimated spatially resolved atmospheric emissions of lindane throughout Europe within the lower atmosphere and surface soil compartments. In accordance with the predominant wind direction in Europe, the model predicts high concentrations close to the major sources as well as towards Central and Northeast regions. Elevated soil concentrations in Scandinavian soils provide further evidence of the potential of increased scavenging by forests and subsequent accumulation by organic-rich terrestrial surfaces. Initial model predictions have revealed a factor of 5-10 underestimation of lindane concentrations in the atmosphere. This is explained by an underestimation of source strength and/or an underestimation of European background levels. The model presented can further be used to predict deposition fluxes and chemical inventories, and it

  20. Pollution distribution and health risk assessment of heavy metals in indoor dust in Anhui rural, China.

    Science.gov (United States)

    Lin, Yuesheng; Fang, Fengman; Wang, Fei; Xu, Minglu

    2015-09-01

    Zn, Pb, Cu, Cr, V, Ni, Co, and As concentrations of indoor dust in Anhui rural were determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The degrees of metal pollution in indoor dust ranked as follows: Zn > Pb > Cr > Cu > V > Ni > Co > As, on average. The arithmetic means of Zn, Pb, Cu, Cr, V, Ni, Co, and As were 427.17, 348.73, 107.05, 113.68, 52.64, 38.93, 10.29, and 4.46 mg/kg, respectively. These were higher than background values of Anhui soil for Zn, Pb, Cu, Cr, and Ni, especially for Pb with the mean value of 13.21 times the background value. Heavy metal concentrations of indoor dust were different from different rural areas. House type (bungalows or storied house), sweeping frequency, and external environment around the house (such as the road grade) affected heavy metal concentrations in indoor dust. The results of factor analysis and correlation analysis indicated that Cu, Cr, Ni, Zn, and Co concentrations were mainly due to interior paint, metal objects, and building materials. Pb and As concentrations were due to vehicle emissions. V concentration was mainly of natural source. Average daily doses for the exposure pathway of the studied heavy metals decreased in children in the following order: hand-to-mouth ingestion > dermal contact > inhalation. The non-carcinogenic risks of heavy metals ranked as Pb > V > Cr > Cu > Zn > As > Co > Ni, and the carcinogenic risks of metals decreased in the order of Cr > Co > As > Ni. The non-carcinogenic hazard indexes and carcinogenic risks of metals in indoor dust were both lower than the safe values.

  1. Spatial distribution of bottlenose dolphins (Tursiops truncatus) inferred from stable isotopes and priority organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Rachel Marie, E-mail: ryounge@ocean.fsu.edu [Department of EOAS-Oceanography, Florida State University, 117 North Woodward Avenue, Tallahassee, Florida, 32306 (United States); Kucklick, John R. [National Institute of Standards and Technology, Hollings Marine Laboratory, Charleston, 331 Fort Johnson Road, Charleston, South Carolina 29412 (United States); Balmer, Brian C.; Wells, Randall S. [Chicago Zoological Society c/o Mote Marine Laboratory, 1600 Ken Thompson Parkway Sarasota, FL, 34236 (United States); Chanton, Jeffrey P. [Department of EOAS-Oceanography, Florida State University, 117 North Woodward Avenue, Tallahassee, Florida, 32306 (United States); Nowacek, Douglas P. [Nicholas School of the Environment and Pratt School of Engineering, Duke University - Marine Laboratory, 135 Duke Marine Lab Rd., Beaufort, NC 28516 (United States)

    2012-05-15

    Differences in priority organic pollutants (POPs), analyzed by gas chromatography-mass spectrometry, and stable isotope ratios ({delta}{sup 13}C, {delta}{sup 34}S, and {delta}{sup 15}N; analyzed by isotope ratio-mass spectrometry), divide 77 bottlenose dolphins (Tursiops truncatus) from the Florida Gulf Coast into three distinct groups. POP levels reflect human population and historical contamination along the coast. In the least disturbed site, concentrations of {Sigma}POP in male dolphins were 18,000 ng g{sup -1} {+-} 6000 (95% confidence interval here and throughout); in the intermediate bay, males had {Sigma}POP concentrations of 19,000 ng g{sup -1} {+-} 10,000. St Andrews Bay was home to dolphins with the highest {Sigma}POP concentrations: 44,000 ng g{sup -1} {+-} 10,300. {delta}{sup 34}S and {delta}{sup 15}N, differed significantly between St. George Sound dolphins and those frequenting each of the other two bays, but not between St. Andrews and St. Joseph Bays. {Sigma}POP concentrations were statistically higher in dolphins frequenting St. Andrews Bay, but were not significantly different between dolphins occupying St. Joseph Bay and St. George Sound. Thus, using either POP or isotope values alone, we would only be able to identify two dolphin groups, but when POP and isotope data are viewed cumulatively, the results clearly define three distinct communities occupying this region. - Highlights: Black-Right-Pointing-Pointer We compare isotopes and POP levels in dolphins occupying three embayments. Black-Right-Pointing-Pointer POP levels varied significantly among two embayments separated by < 50 km. Black-Right-Pointing-Pointer Differentiation correlated with historical contamination from a SuperFund site. Black-Right-Pointing-Pointer Cumulatively, isotopes and POP levels indicate 3 distinct dolphin communities. Black-Right-Pointing-Pointer This data provides the first assessment of dolphin POP contamination in the region.

  2. Large-scale upper tropospheric pollution observed by MIPAS HCN and C2H6 global distributions

    Science.gov (United States)

    Glatthor, N.; von Clarmann, T.; Stiller, G. P.; Funke, B.; Koukouli, M. E.; Fischer, H.; Grabowski, U.; Höpfner, M.; Kellmann, S.; Linden, A.

    2009-12-01

    We present global upper tropospheric HCN and C2H6 amounts derived from MIPAS/ENVISAT limb emission spectra. HCN and C2H6 are retrieved in the spectral regions 715.5-782.7 cm-1 and 811.5-835.7 cm-1, respectively. The datasets consist of 54 days between September 2003 and March 2004. This period covers the peak and decline of the southern hemispheric biomass burning period and some months thereafter. HCN is a nearly unambiguous tracer of biomass burning with an assumed tropospheric lifetime of several months. Indeed, the most significant feature in the MIPAS HCN dataset is an upper tropospheric plume of enhanced values caused by southern hemispheric biomass burning, which in September and October 2003 extended from tropical South America over Africa, Australia to the Southern Pacific. The spatial extent of this plume agrees well with the MOPITT CO distribution of September 2003. Further there is good agreement with the shapes and mixing ratios of the southern hemispheric HCN and C2H6 fields measured by the ACE experiment between September and November 2005. The MIPAS HCN plume extended from the lowermost observation height of 8 km up to about 16 km altitude, with maximum values of 500-600 pptv in October 2003. It was still clearly visible in December 2003, but had strongly decreased by March 2004, confirming the assumed tropospheric lifetime. The main sources of C2H6 are production and transmission of fossil fuels, followed by biofuel use and biomass burning. The C2H6 distribution also clearly reflected the southern hemispheric biomass burning plume and its seasonal variation, with maximum amounts of 600-700 pptv. Generally there was good spatial overlap between the southern hemispheric distributions of both pollution tracers, except for the region between Peru and the mid-Pacific. Here C2H6was considerably enhanced, whereas the HCN amounts were low. Backward trajectory calculations suggested that industrial pollution was responsible for the elevated C2H6

  3. Large-scale upper tropospheric pollution observed by MIPAS HCN and C2H6 global distributions

    Directory of Open Access Journals (Sweden)

    A. Linden

    2009-12-01

    Full Text Available We present global upper tropospheric HCN and C2H6 amounts derived from MIPAS/ENVISAT limb emission spectra. HCN and C2H6 are retrieved in the spectral regions 715.5–782.7 cm−1 and 811.5–835.7 cm−1, respectively. The datasets consist of 54 days between September 2003 and March 2004. This period covers the peak and decline of the southern hemispheric biomass burning period and some months thereafter. HCN is a nearly unambiguous tracer of biomass burning with an assumed tropospheric lifetime of several months. Indeed, the most significant feature in the MIPAS HCN dataset is an upper tropospheric plume of enhanced values caused by southern hemispheric biomass burning, which in September and October 2003 extended from tropical South America over Africa, Australia to the Southern Pacific. The spatial extent of this plume agrees well with the MOPITT CO distribution of September 2003. Further there is good agreement with the shapes and mixing ratios of the southern hemispheric HCN and C2H6 fields measured by the ACE experiment between September and November 2005. The MIPAS HCN plume extended from the lowermost observation height of 8 km up to about 16 km altitude, with maximum values of 500–600 pptv in October 2003. It was still clearly visible in December 2003, but had strongly decreased by March 2004, confirming the assumed tropospheric lifetime. The main sources of C2H6 are production and transmission of fossil fuels, followed by biofuel use and biomass burning. The C2H6 distribution also clearly reflected the southern hemispheric biomass burning plume and its seasonal variation, with maximum amounts of 600–700 pptv. Generally there was good spatial overlap between the southern hemispheric distributions of both pollution tracers, except for the region between Peru and the mid-Pacific. Here C2H6was considerably enhanced, whereas the HCN amounts were low. Backward trajectory calculations suggested that industrial pollution was responsible

  4. Differentiating impacts of land use changes from pasture management in a CEAP watershed using the SWAT model

    Science.gov (United States)

    Due to intensive farm practices, nonpoint-source (NPS) pollution has become one of the most challenging environmental problems in agricultural and mixed land use watersheds. Usually, various conservation practices are implemented in the watershed to control the NPS pollution problem. However, land u...

  5. [Multiple time scales analysis of spatial differentiation characteristics of non-point source nitrogen loss within watershed].

    Science.gov (United States)

    Liu, Mei-bing; Chen, Xing-wei; Chen, Ying

    2015-07-01

    Identification of the critical source areas of non-point source pollution is an important means to control the non-point source pollution within the watershed. In order to further reveal the impact of multiple time scales on the spatial differentiation characteristics of non-point source nitrogen loss, a SWAT model of Shanmei Reservoir watershed was developed. Based on the simulation of total nitrogen (TN) loss intensity of all 38 subbasins, spatial distribution characteristics of nitrogen loss and critical source areas were analyzed at three time scales of yearly average, monthly average and rainstorms flood process, respectively. Furthermore, multiple linear correlation analysis was conducted to analyze the contribution of natural environment and anthropogenic disturbance on nitrogen loss. The results showed that there were significant spatial differences of TN loss in Shanmei Reservoir watershed at different time scales, and the spatial differentiation degree of nitrogen loss was in the order of monthly average > yearly average > rainstorms flood process. TN loss load mainly came from upland Taoxi subbasin, which was identified as the critical source area. At different time scales, land use types (such as farmland and forest) were always the dominant factor affecting the spatial distribution of nitrogen loss, while the effect of precipitation and runoff on the nitrogen loss was only taken in no fertilization month and several processes of storm flood at no fertilization date. This was mainly due to the significant spatial variation of land use and fertilization, as well as the low spatial variability of precipitation and runoff.

  6. Modelling global distribution, risk and mitigation strategies of floating plastic pollution

    Science.gov (United States)

    van Sebille, Erik; Wilcox, Chris; Sherman, Peter; Hardesty, Britta Denise; Lavender Law, Kara

    2016-04-01

    Microplastic debris floating at the ocean surface can harm marine life. Understanding the severity of this harm requires knowledge of plastic abundance and distributions. Dozens of expeditions measuring microplastics have been carried out since the 1970s, but they have primarily focused on the North Pacific and North Atlantic accumulation zones, with much sparser coverage elsewhere. Here, we use the largest dataset of microplastic measurements assembled to date to assess the confidence we can have in global estimates of microplastic abundance and mass. We use a rigorous statistical framework to standardise a global dataset of plastic marine debris measured using surface-trawling plankton nets and couple this with three different ocean circulation models to spatially interpolate the observations. Our estimates show that the accumulated number of microplastic particles in 2014 ranges from 15 to 51 trillion particles, weighing between 93 and 236 thousand metric tons. A large fraction of the uncertainty in these estimates comes from sparse sampling in coastal and Southern Hemisphere regions. We then use this global distribution of small floating plastic debris to map out where in the ocean the risk to marine life (in particular seabirds and plankton growth) is greatest, using a quantitative risk framework. We show that the largest risk occurs not necessarily in regions of high plastic concentration, but rather in regions of extensive foraging with medium-high plastic concentrations such as coastal upwelling regions and the Southern Ocean. Finally, we use the estimates of distribution to investigate where in the ocean plastic can most optimally be removed, assuming hypothetical clean-up booms following the ideas from The Ocean Cleanup project. We show that mitigation of the plastic problem can most aptly be done near coastlines, particularly in Asia, rather than in the centres of the gyres. Based on these results, we propose more focus on the coastal zones when

  7. Interactive genetic algorithm for user-centered design of distributed conservation practices in a watershed: An examination of user preferences in objective space and user behavior

    Science.gov (United States)

    Piemonti, Adriana Debora; Babbar-Sebens, Meghna; Mukhopadhyay, Snehasis; Kleinberg, Austin

    2017-05-01

    Interactive Genetic Algorithms (IGA) are advanced human-in-the-loop optimization methods that enable humans to give feedback, based on their subjective and unquantified preferences and knowledge, during the algorithm's search process. While these methods are gaining popularity in multiple fields, there is a critical lack of data and analyses on (a) the nature of interactions of different humans with interfaces of decision support systems (DSS) that employ IGA in water resources planning problems and on (b) the effect of human feedback on the algorithm's ability to search for design alternatives desirable to end-users. In this paper, we present results and analyses of observational experiments in which different human participants (surrogates and stakeholders) interacted with an IGA-based, watershed DSS called WRESTORE to identify plans of conservation practices in a watershed. The main goal of this paper is to evaluate how the IGA adapts its search process in the objective space to a user's feedback, and identify whether any similarities exist in the objective space of plans found by different participants. Some participants focused on the entire watershed, while others focused only on specific local subbasins. Additionally, two different hydrology models were used to identify any potential differences in interactive search outcomes that could arise from differences in the numerical values of benefits displayed to participants. Results indicate that stakeholders, in comparison to their surrogates, were more likely to use multiple features of the DSS interface to collect information before giving feedback, and dissimilarities existed among participants in the objective space of design alternatives.

  8. Observations of the vertical distributions of summertime atmospheric pollutants and the corresponding ozone production in Shanghai, China

    Science.gov (United States)

    Xing, Chengzhi; Liu, Cheng; Wang, Shanshan; Chan, Ka Lok; Gao, Yang; Huang, Xin; Su, Wenjing; Zhang, Chengxin; Dong, Yunsheng; Fan, Guangqiang; Zhang, Tianshu; Chen, Zhenyi; Hu, Qihou; Su, Hang; Xie, Zhouqing; Liu, Jianguo

    2017-12-01

    Ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) and lidar measurements were performed in Shanghai, China, during May 2016 to investigate the vertical distribution of summertime atmospheric pollutants. In this study, vertical profiles of aerosol extinction coefficient, nitrogen dioxide (NO2) and formaldehyde (HCHO) concentrations were retrieved from MAX-DOAS measurements using the Heidelberg Profile (HEIPRO) algorithm, while vertical distribution of ozone (O3) was obtained from an ozone lidar. Sensitivity study of the MAX-DOAS aerosol profile retrieval shows that the a priori aerosol profile shape has significant influences on the aerosol profile retrieval. Aerosol profiles retrieved from MAX-DOAS measurements with Gaussian a priori profile demonstrate the best agreements with simultaneous lidar measurements and vehicle-based tethered-balloon observations among all a priori aerosol profiles. Tropospheric NO2 vertical column densities (VCDs) measured with MAX-DOAS show a good agreement with OMI satellite observations with a Pearson correlation coefficient (R) of 0.95. In addition, measurements of the O3 vertical distribution indicate that the ozone productions do not only occur at surface level but also at higher altitudes (about 1.1 km). Planetary boundary layer (PBL) height and horizontal and vertical wind field information were integrated to discuss the ozone formation at upper altitudes. The results reveal that enhanced ozone concentrations at ground level and upper altitudes are not directly related to horizontal and vertical transportation. Similar patterns of O3 and HCHO vertical distributions were observed during this campaign, which implies that the ozone productions near the surface and at higher altitudes are mainly influenced by the abundance of volatile organic compounds (VOCs) in the lower troposphere.

  9. Distribution and ecological risk assessment of cadmium in water and sediment in Longjiang River, China: Implication on water quality management after pollution accident.

    Science.gov (United States)

    Zhao, Xue-Min; Yao, Ling-Ai; Ma, Qian-Li; Zhou, Guang-Jie; Wang, Li; Fang, Qiao-Li; Xu, Zhen-Cheng

    2018-03-01

    In early January 2012, the Longjiang River was subjected to a serious cadmium (Cd) pollution accident, which led to negatively environmental and social impacts. A series of measures of emergency treatment were subsequently taken to reduce water Cd level. However, little information was available about the change of Cd level in environmental matrices and long-term effect of this pollution accident to aquatic ecosystem. Thus, this study investigated the distribution of Cd in water and sediment of this river for two years since pollution accident, as well as assessed its ecological risk to aquatic ecosystem of Longjiang River. The results showed that it was efficient for taking emergency treatment measures to decrease water Cd concentration to below the threshold value of national drinking water quality standard of China. There was high risk (HQ > 1) to aquatic ecosystem in some of reaches between February and July 2012, but low or no risk (HQ polluted reaches increased after pollution accident and emergency treatments in 2012, but decreased in 2013. During flood period, the sediment containing high concentration of Cd in Longjiang River was migrated to downstream Liujiang River. Cd content in sediment was reduced to background level after two years of the pollution accident occurrence. The study provides basic information about Cd levels in different media after pollution accident, which is helpful in evaluating the effectiveness of emergency treatments and the variation of ecological risk, as well as in conducting water management and conservation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Accumulation and in vivo tissue distribution of pollutant elements in Erica andevalensis

    International Nuclear Information System (INIS)

    Rossini Oliva, S.; Valdes, B.; Leidi, E.O.

    2009-01-01

    Erica andevalensis is an endemic shrub from an area in the southwest of Spain (Andalucia) characterized by acidic and contaminated soils. Scanning electron microscopy (SEM) of samples after conventional or cryo-fixation preparation protocols was used for morphological and anatomical studies. SEM coupled with EDX-analysis was employed to localise and quantify different elements within plant parts (leaves, stems and roots) in samples collected in the field. Morphological studies revealed that the species has typical adaptive structures to drought-stress such as rolled needle-like leaves, sunken stomata and a thick waxy cuticle on the upper epidermis. Roots were associated with fungi which formed intra and extra-cellular mycelia. The SEM studies showed that Cu was not sequestrated into the root tissues and was uniformly distributed in leaf tissues. Meanwhile, Pb was only localised within epidermal root tissues which indicates that its sequestration in an external matrix might represent a tolerance mechanism in this species. Iron was uniformly distributed throughout the leaves, while in roots it was predominantly retained on the epidermal cell walls. The exclusion and tolerance mechanisms adopted by this species to survive in mining areas indicate that it can be used successfully in the re-vegetation of contaminated areas

  11. Accumulation and in vivo tissue distribution of pollutant elements in Erica andevalensis

    Energy Technology Data Exchange (ETDEWEB)

    Rossini Oliva, S. [Department of Plant Biology and Ecology, University of Seville, Avda. Reina Mercedes s/n, Apartado de Correo 1095, 41080 Sevilla (Spain)], E-mail: sabina@us.es; Valdes, B. [Department of Plant Biology and Ecology, University of Seville, Avda. Reina Mercedes s/n, Apartado de Correo 1095, 41080 Sevilla (Spain); Leidi, E.O. [Department of Plant Biotechnology, IRNAS-CSIC, Avda. Reina Mercedes 10, 41012 Sevilla (Spain)

    2009-03-01

    Erica andevalensis is an endemic shrub from an area in the southwest of Spain (Andalucia) characterized by acidic and contaminated soils. Scanning electron microscopy (SEM) of samples after conventional or cryo-fixation preparation protocols was used for morphological and anatomical studies. SEM coupled with EDX-analysis was employed to localise and quantify different elements within plant parts (leaves, stems and roots) in samples collected in the field. Morphological studies revealed that the species has typical adaptive structures to drought-stress such as rolled needle-like leaves, sunken stomata and a thick waxy cuticle on the upper epidermis. Roots were associated with fungi which formed intra and extra-cellular mycelia. The SEM studies showed that Cu was not sequestrated into the root tissues and was uniformly distributed in leaf tissues. Meanwhile, Pb was only localised within epidermal root tissues which indicates that its sequestration in an external matrix might represent a tolerance mechanism in this species. Iron was uniformly distributed throughout the leaves, while in roots it was predominantly retained on the epidermal cell walls. The exclusion and tolerance mechanisms adopted by this species to survive in mining areas indicate that it can be used successfully in the re-vegetation of contaminated areas.

  12. Nitrate pollution and its distribution in the groundwater of Srikakulam district, Andhra Pradesh, India

    Science.gov (United States)

    Rao, Nagireddi Srinivasa

    2006-12-01

    The complex depositional pattern of clay and sand in most of the areas controlled the vertical and lateral movement of nitrate in groundwater. The variation of nitrate concentration at different groundwater levels and the lateral distribution of nitrate in the groundwater at two sites indicated the filtration of nitrate by clayey formations. A rural agricultural district located in the Vamsadhara river basin, India was selected for studying the lateral and vertical distribution of nitrate in the groundwater and the association of nitrate with other chemical constituents. The nitrate concentrations in the groundwater are observed to vary between below detectable limit and 450 mg NO3/L. The sources for nitrate are mainly point sources (poultry farms, cattleshed and leakages from septic tanks) and non-point sources (nitrogenous fertilisers). The nitrate concentrations are increased after fertiliser applications. However, very high concentrations of nitrate are derived from animal wastes. Relatively better correlations between nitrate and potassium are observed ( R = 0.74 to 0.82). The better relationship between these two chemical constituents in the groundwater may be due to the release of potassium and nitrate from both point and non-point sources. The nitrate and potassium concentrations are high in the groundwater from clayey formations.

  13. Analysis on Heavy Metal Distribution in Overlying Deposit and Pollution Characteristics in Drainage Basin of Xiaojiang River in Dongchuan District, China

    Science.gov (United States)

    Huang, Qianrui; Cheng, Xianfeng; Xu, Jun; Qi, Wufu; Yang, Shuran; Dong, Tao; Zhang, Xiangqun

    2017-12-01

    The distribution characteristics of heavy metal (Cu, Zn, As, Pb and Cd) content in overlying deposit in Xiaojiang River is analyzed in this thesis, and potential ecological risk index is adopted to evaluate the potential ecological risk of heavy metal pollution in the overlying deposit. Results indicate that the heavy metal (Cu, Zn, As, Pb and Cd) content in overlying deposit in Xiaojiang River all has exceeded standard, especially the content near diggings which is much higher than the national first standard value. And this will affect the bottom mud and river system of Jinsha River to some extent. Cu and Cd are the key pollutants and should be taken as the key object of study. It can be seen from comparison between samples in wet season and that in dry season that pollutants in bottom mud will be released due to the effect of pH value, and secondary pollution of the river will be caused.

  14. The spatial-temporal distribution of the atmospheric polluting agents during the period 2000-2005 in the Urban Area of Guadalajara, Jalisco, Mexico.

    Science.gov (United States)

    Sánchez, Hermes U Ramírez; García, María D Andrade; Bejaran, Rubén; Guadalupe, Mario E García; Vázquez, Antonio Wallo; Toledano, Ana C Pompa; Villasenor, Odila de la Torre

    2009-06-15

    In the large cities, the disordered urban development, the industrial activities, and the transport, have caused elevated concentrations of polluting agents and possible risks to the health of the population. The metropolises located in valleys with little ventilation (such as the Urban Area of Guadalajara: UAG) present low dispersion of polluting agents can cause high risk of respiratory and cardiovascular diseases. The objective of this work was to describe the spatial-temporal distribution of the atmospheric polluting agents: carbon monoxide (CO), nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), particles smaller than 10 microns (microm) (PM(10)) and ozone (O(3)) in the UAG during the period 2000-2005. A spatial-temporal distribution analysis was made by means of graphic interpolation (Kriging method) of the statistical parameters of CO, NO(2), SO(2), PM(10) and O(3) with the collected data from eight stations of atmospheric monitoring in the UAG. The results show that the distributions of the atmospheric polluting agents are variable during the analyzed years. The polluting agent with highest concentration is PM(10) (265.42 microg/m(3)), followed by O(3) (0.11 ppm), NO(2) (0.11 ppm), CO (9.17 ppm) and SO(2) (0.05 ppm). The most affected zone is the southeast of the UAG. The results showed that an important percentage of days exceed the Mexican norms of air quality (93-199 days/year).

  15. Autonomous watersheds: Reducing flooding and stream erosion through real-time control

    Science.gov (United States)

    Kerkez, B.; Wong, B. P.

    2017-12-01

    We introduce an analytical toolchain, based on dynamical system theory and feedback control, to determine how many control points (valves, gates, pumps, etc.) are needed to transform urban watersheds from static to adaptive. Advances and distributed sensing and control stand to fundamentally change how we manage urban watersheds. In lieu of new and costly infrastructure, the real-time control of stormwater systems will reduce flooding, mitigate stream erosion, and improve the treatment of polluted runoff. We discuss the how open source technologies, in the form of wireless sensor nodes and remotely-controllable valves (open-storm.org), have been deployed to build "smart" stormwater systems in the Midwestern US. Unlike "static" infrastructure, which cannot readily adapt to changing inputs and land uses, these distributed control assets allow entire watersheds to be reconfigured on a storm-by-storm basis. Our results show how the control of even just a few valves within urban catchments (1-10km^2) allows for the real-time "shaping" of hydrographs, which reduces downstream erosion and flooding. We also introduce an equivalence framework that can be used by decision-makers to objectively compare investments into "smart" system to more traditional solutions, such as gray and green stormwater infrastructure.

  16. Identification of Watershed-scale Critical Source Areas Using Bayesian Maximum Entropy Spatiotemporal Analysis

    Science.gov (United States)

    Roostaee, M.; Deng, Z.

    2017-12-01

    The states' environmental agencies are required by The Clean Water Act to assess all waterbodies and evaluate potential sources of impairments. Spatial and temporal distributions of water quality parameters are critical in identifying Critical Source Areas (CSAs). However, due to limitations in monetary resources and a large number of waterbodies, available monitoring stations are typically sparse with intermittent periods of data collection. Hence, scarcity of water quality data is a major obstacle in addressing sources of pollution through management strategies. In this study spatiotemporal Bayesian Maximum Entropy method (BME) is employed to model the inherent temporal and spatial variability of measured water quality indicators such as Dissolved Oxygen (DO) concentration for Turkey Creek Watershed. Turkey Creek is located in northern Louisiana and has been listed in 303(d) list for DO impairment since 2014 in Louisiana Water Quality Inventory Reports due to agricultural practices. BME method is proved to provide more accurate estimates than the methods of purely spatial analysis by incorporating space/time distribution and uncertainty in available measured soft and hard data. This model would be used to estimate DO concentration at unmonitored locations and times and subsequently identifying CSAs. The USDA's crop-specific land cover data layers of the watershed were then used to determine those practices/changes that led to low DO concentration in identified CSAs. Primary results revealed that cultivation of corn and soybean as well as urban runoff are main contributing sources in low dissolved oxygen in Turkey Creek Watershed.

  17. The influence of climate change on the global distribution and fate processes of anthropogenic persistent organic pollutants.

    Science.gov (United States)

    Kallenborn, Roland; Halsall, Crispin; Dellong, Maud; Carlsson, Pernilla

    2012-11-01

    The effect of climate change on the global distribution and fate of persistent organic pollutants (POPs) is of growing interest to both scientists and policy makers alike. The impact of warmer temperatures and the resulting changes to earth system processes on chemical fate are, however, unclear, although there are a growing number of studies that are beginning to examine these impacts and changes in a quantitative way. In this review, we examine broad areas where changes are occurring or are likely to occur with regard to the environmental cycling and fate of chemical contaminants. For this purpose we are examining scientific information from long-term monitoring data with particular emphasis on the Arctic, to show apparent changes in chemical patterns and behaviour. In addition, we examine evidence of changing chemical processes for a number of environmental compartments and indirect effects of climate change on contaminant emissions and behaviour. We also recommend areas of research to address knowledge gaps. In general, our findings indicate that the indirect consequences of climate change (i.e. shifts in agriculture, resource exploitation opportunities, etc.) will have a more marked impact on contaminants distribution and fate than direct climate change.

  18. Spatial Distribution and Pollution Characteristics of Heavy Metals in Soil of Mentougou Mining Area of Beijing City, China

    Directory of Open Access Journals (Sweden)

    XING Yu-xin

    2016-11-01

    Full Text Available The pollution characteristics and spatial distribution of soil heavy metals around mine-concentrated area in Mentougou were comprehensive studied using ArcGIS carried by inverse distance weighted interpolation mathematical model and SPSS multivariate statistical analysis. The ecological risk assessment was carried out by the potential ecological risk index. The results showed that the spatial distribution of soil heavy metal concentrations increased gradually from the west to the east of study area. Harmful degrees of heavy metals decreased in the order of Hg > Cd > Pb > Cr > Zn > Cu > Ni > As. Combination of coal mining and human activity caused the strongest risk, while the risks caused by heavy metals from sandstone minerals was relatively weak. The potential ecological risk indexes(RI of eight heavy metals were between 67.81 and 668.53. The order of the potential ecological risk was Hg > Cd > As > Pb > Ni > Cu > Cr > Zn. In summary, the heavy metals in soil of the study area were harmful. Because the study area is located in the ecological conservation district of Beijing, the ecological harm should not be overlooked, and needs to be evaluated and repaired.

  19. A Modeling Investigation of Human Exposure to Select Traffic-Related Air Pollutants in the Tampa Area: Spatiotemporal Distributions of Concentrations, Social Distributions of Exposures, and Impacts of Urban Design on Both

    Science.gov (United States)

    Yu, Haofei

    Increasing vehicle dependence in the United States has resulted in substantial emissions of traffic-related air pollutants that contribute to the deterioration of urban air quality. Exposure to urban air pollutants trigger a number of public health concerns, including the potential of inequality of exposures and health effects among population subgroups. To better understand the impact of traffic-related pollutants on air quality, exposure, and exposure inequality, modeling methods that can appropriately characterize the spatiotemporally resolved concentration distributions of traffic-related pollutants need to be improved. These modeling methods can then be used to investigate the impacts of urban design and transportation management choices on air quality, pollution exposures, and related inequality. This work will address these needs with three objectives: 1) to improve modeling methods for investigating interactions between city and transportation design choices and air pollution exposures, 2) to characterize current exposures and the social distribution of exposures to traffic-related air pollutants for the case study area of Hillsborough County, Florida, and 3) to determine expected impacts of urban design and transportation management choices on air quality, air pollution exposures, and exposure inequality. To achieve these objectives, the impacts of a small-scale transportation management project, specifically the '95 Express' high occupancy toll lane project, on pollutant emissions and nearby air quality was investigated. Next, a modeling method capable of characterizing spatiotemporally resolved pollutant emissions, concentrations, and exposures was developed and applied to estimate the impact of traffic-related pollutants on exposure and exposure inequalities among several population subgroups in Hillsborough County, Florida. Finally, using these results as baseline, the impacts of sprawl and compact urban forms, as well as vehicle fleet electrification

  20. [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.

  1. Economic Tools for Managing Nitrogen in Coastal Watersheds ...

    Science.gov (United States)

    Watershed managers are interested in using economics to communicate the value of estuarine resources to the wider community, determine the most cost-effective means to reduce nitrogen pollution, and evaluate the benefits of taking action to improve coastal ecosystems. We spoke to coastal watershed managers who had commissioned economic studies and found that they were largely satisfied with the information and their ability to communicate the importance of coastal ecosystems. However, while managers were able to use these studies as communication tools, methods used in some studies were inconsistent with what some economists consider best practices. In addition, many watershed managers are grappling with how to implement nitrogen management activities in a way that is both cost-effective and achieves environmental goals, while maintaining public support. These and other issues led to this project. Our intent is to provide information to watershed managers and others interested in watershed management – such as National Estuary Programs, local governments, or nongovernmental organizations – on economic tools for managing nitrogen in coastal watersheds, and to economists and other analysts who are interested in assisting them in meeting their needs. Watershed management requires balancing scientific, political, and social issues to solve environmental problems. This document summarizes questions that watershed managers have about using economic analysis, and g

  2. Phosphorus export across an urban to rural gradient in the Chesapeake Bay watershed

    Science.gov (United States)

    Shuiwang Duan; Sujay S. Kaushal; Peter Groffman; Lawrence E. Band; Kenneth Belt

    2012-01-01

    Watershed export of phosphorus (P) from anthropogenic sources has contributed to eutrophication in freshwater and coastal ecosystems. We explore impacts of watershed urbanization on the magnitude and export flow distribution of P along an urban-rural gradient in eight watersheds monitored as part of the Baltimore Ecosystem Study Long-Term Ecological Research site....

  3. Radioactive pollution of the Chernobyl cooling pond bottom sediments. II. Distribution of 137Cs, 241Am, 90Sr in a solid phase

    Directory of Open Access Journals (Sweden)

    L. S. Pirnach

    2011-12-01

    Full Text Available The second part of complex research of the Chernobyl cooling pond bottom sediments are presented Data about vertical distribution of radioactive pollution 137Cs, 241Am, 90Sr in a solid phase of sediments are received. Distribution coefficients 137Cs and 90Sr, selectivity coefficients of their exchange with similar cations and physical-chemical forms are defined. Results of research of radionuclide chemical recovery from the sediment samples are analyzed.

  4. Size distribution, directional source contributions and pollution status of PM from Chengdu, China during a long-term sampling campaign.

    Science.gov (United States)

    Shi, Guo-Liang; Tian, Ying-Ze; Ma, Tong; Song, Dan-Lin; Zhou, Lai-Dong; Han, Bo; Feng, Yin-Chang; Russell, Armistead G

    2017-06-01

    Long-term and synchronous monitoring of PM 10 and PM 2.5 was conducted in Chengdu in China from 2007 to 2013. The levels, variations, compositions and size distributions were investigated. The sources were quantified by two-way and three-way receptor models (PMF2, ME2-2way and ME2-3way). Consistent results were found: the primary source categories contributed 63.4% (PMF2), 64.8% (ME2-2way) and 66.8% (ME2-3way) to PM 10 , and contributed 60.9% (PMF2), 65.5% (ME2-2way) and 61.0% (ME2-3way) to PM 2.5 . Secondary sources contributed 31.8% (PMF2), 32.9% (ME2-2way) and 31.7% (ME2-3way) to PM 10 , and 35.0% (PMF2), 33.8% (ME2-2way) and 36.0% (ME2-3way) to PM 2.5 . The size distribution of source categories was estimated better by the ME2-3way method. The three-way model can simultaneously consider chemical species, temporal variability and PM sizes, while a two-way model independently computes datasets of different sizes. A method called source directional apportionment (SDA) was employed to quantify the contributions from various directions for each source category. Crustal dust from east-north-east (ENE) contributed the highest to both PM 10 (12.7%) and PM 2.5 (9.7%) in Chengdu, followed by the crustal dust from south-east (SE) for PM 10 (9.8%) and secondary nitrate & secondary organic carbon from ENE for PM 2.5 (9.6%). Source contributions from different directions are associated with meteorological conditions, source locations and emission patterns during the sampling period. These findings and methods provide useful tools to better understand PM pollution status and to develop effective pollution control strategies. Copyright © 2016. Published by Elsevier B.V.

  5. Watershed condition [Chapter 4

    Science.gov (United States)

    Daniel G. Neary; Jonathan W. Long; Malchus B. Baker

    2012-01-01

    Managers of the Prescott National Forest are obliged to evaluate the conditions of watersheds under their jurisdiction in order to guide informed decisions concerning grazing allotments, forest and woodland management, restoration treatments, and other management initiatives. Watershed condition has been delineated by contrasts between “good” and “poor” conditions (...

  6. Distribution and pollution, toxicity and risk assessment of heavy metals in sediments from urban and rural rivers of the Pearl River delta in southern China.

    Science.gov (United States)

    Xiao, Rong; Bai, Junhong; Huang, Laibin; Zhang, Honggang; Cui, Baoshan; Liu, Xinhui

    2013-12-01

    Sediments were collected from the upper, middle and lower reaches of both urban and rural rivers in a typical urbanization zone of the Pearl River delta. Six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) were analyzed in all sediment samples, and their spatial distribution, pollution levels, toxicity and ecological risk levels were evaluated to compare the characteristics of heavy metal pollution between the two rivers. Our results indicated that the total contents of the six metals in all samples exceeded the soil background value in Guangdong province. Based on the soil quality thresholds of the China SEPA, Cd levels at all sites exceeded class III criteria, and other metals exhibited pollution levels exceeding class II or III criteria at both river sites. According to the sediment quality guidelines of the US EPA, all samples were moderately to heavily polluted by Cr, Cu, Ni, Pb and Zn. Compared to rural river sites, urban river sites exhibited heavier pollution. Almost all sediment samples from both rivers exhibited moderate to serious toxicity to the environment, with higher contributions from Cr and Ni. A "hot area" of heavy metal pollution being observed in the upper and middle reaches of the urban river area, whereas a "hot spot" was identified at a specific site in the middle reach of the rural river. Contrary metal distribution patterns were also observed along typical sediment profiles from urban and rural rivers. However, the potential ecological risk indices of rural river sediments in this study were equal to those of urban river sediments, implying that the ecological health issues of the rivers in the undeveloped rural area should also be addressed. Sediment organic matter and grain size might be important factors influencing the distribution profiles of these heavy metals.

  7. Apex simulation: environmental benefits of agroforestry and grass buffers for corn-soybean watersheds

    Science.gov (United States)

    The Agricultural Policy Environmental Extender (APEX) model is used to simulate the effects of vegetative filter strips on runoff and pollutant loadings from agricultural watersheds. A long-term paired watershed study under corn (Zea mays L-soybean [Glycine max (L.) Merr.] rotation with agroforestr...

  8. APEX simulation: environmental benefits of agroforestry and grass buffers on corn-soybean watersheds

    Science.gov (United States)

    The Agricultural Policy Environmental Extender (APEX) model has the ability to simulate the effects of vegetative filter strips on runoff and pollutant loadings from agricultural watersheds. The objectives of this study were to calibrate and validate the APEX model for three adjacent watersheds and...

  9. Hydrologic processes of forested headwater watersheds across a physiographaic gradient in the southeastern United States

    Science.gov (United States)

    Ge Sun; Johnny Boggs; Steven G. McNulty; Devendra M. Amatya; Carl C. Trettin; Zhaohua Dai; James M. Vose; Ileana B. La Torre Torres; Timothy Callahan

    2008-01-01

    Understanding the hydrologic processes is the first step in making sound watershed management decisions including designing Best Management Practices for nonpoint source pollution control. Over the past fifty years, various forest experimental watersheds have been instrumented across the Carolinas through collaborative studies among federal, state, and private...

  10. Temporal and geographical distributions of epilithic sodium dodecyl sulfate-degrading bacteria in a polluted South Wales river

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, D.J.; Day, M.J.; Russell, N.J.; White, G.F.

    1988-02-01

    Epilithic bacteria were isolated nonselectively from riverbed stones and examined by gel zymography for their ability to produce alkylsulfatase (AS) enzymes and thus to metabolize alkyl sulfate surfactants such as sodium dodecyl sulfate. The percentages of AS+ isolates from stone epilithon at five sites from the source to the river mouth were measured on five sampling days spread over 1 year. The results showed that (i) the prevalence of epilithic AS+ strains (as a percentage of all isolates) was much higher at polluted sites than at the source; (ii) when averaged over the whole river, percentages of AS+ strains were significantly higher at the end of summer compared with either the preceding or the following winter; (iii) analysis of site-sampling time interactions indicated that water quality factors (e.g., biochemical oxygen demand and dissolved oxygen concentration) rather than climatic factors determined the distributions of epilithic AS+ isolates; (iv) constitutive strains were the most prevalent (7.2% of all isolates), with smaller numbers of isolates with inducible (4.5%) and repressible (1.7%) enzymes.

  11. Speciation and distribution characteristics of heavy metals and pollution assessments in the sediments of Nashina Lake, Heilongjiang, China.

    Science.gov (United States)

    Li, Miao; Zang, Shuying; Xiao, Haifeng; Wu, Changshan

    2014-05-01

    Sediment core samples from Nashina Lake, Heilongjiang, China were collected using a gravity sampler. The cores were sliced horizontally at 1 cm each to determine the particle size, total concentrations and speciation of Cd, Cr, Cu, Mn, Ni, Pb, and Zn. Total concentrations of heavy metals were extracted using an acid mixture (containing hydro fluoric acid, nitric acid, and sulphuric acid) and analyzed using an inductively coupled plasma spectrometry. A sequential extraction procedure was employed to separate chemical species. Analysis of results indicate that the concentrations of heavy metals in the sediments of Nashina Lake in descending order are Mn, Cr, Zn, Pb, Ni, Cu, and Cd. The ratios of the average concentrations of four heavy metals (e.g.Cr, Cu, Ni, Zn) to their background values were >1; and those of Mn, Cd, and Pb were >1. Moreover, some toxic metals were mainly distributed in bioavailable fractions. For instance, both Cd and Mn were typically found in Acid-extractable species or Fe-Mn oxide species, and thus can be easily remobilized and enter the food chain. Finally, the analysis of geo-accumulation index showed that anthropogenic pollution levels of Cr, Cu, Mn, Ni, Zn were low, but those of Pb and Cd were at the moderate level. As both Pb and Cd are toxic metals, it is highly necessary to prohibit their transformation and accumulation in the sediments.

  12. Updated greenhouse gas and criteria air pollutant emission factors and their probability distribution functions for electricity generating units

    International Nuclear Information System (INIS)

    Cai, H.; Wang, M.; Elgowainy, A.; Han, J.

    2012-01-01

    Greenhouse gas (CO 2 , CH 4 and N 2 O, hereinafter GHG) and criteria air pollutant (CO, NO x , VOC, PM 10 , PM 2.5 and SO x , hereinafter CAP) emission factors for various types of power plants burning various fuels with different technologies are important upstream parameters for estimating life-cycle emissions associated with alternative vehicle/fuel systems in the transportation sector, especially electric vehicles. The emission factors are typically expressed in grams of GHG or CAP per kWh of electricity generated by a specific power generation technology. This document describes our approach for updating and expanding GHG and CAP emission factors in the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model developed at Argonne National Laboratory (see Wang 1999 and the GREET website at http://greet.es.anl.gov/main) for various power generation technologies. These GHG and CAP emissions are used to estimate the impact of electricity use by stationary and transportation applications on their fuel-cycle emissions. The electricity generation mixes and the fuel shares attributable to various combustion technologies at the national, regional and state levels are also updated in this document. The energy conversion efficiencies of electric generating units (EGUs) by fuel type and combustion technology are calculated on the basis of the lower heating values of each fuel, to be consistent with the basis used in GREET for transportation fuels. On the basis of the updated GHG and CAP emission factors and energy efficiencies of EGUs, the probability distribution functions (PDFs), which are functions that describe the relative likelihood for the emission factors and energy efficiencies as random variables to take on a given value by the integral of their own probability distributions, are updated using best-fit statistical curves to characterize the uncertainties associated with GHG and CAP emissions in life-cycle modeling with GREET.

  13. Updated greenhouse gas and criteria air pollutant emission factors and their probability distribution functions for electricity generating units

    Energy Technology Data Exchange (ETDEWEB)

    Cai, H.; Wang, M.; Elgowainy, A.; Han, J. (Energy Systems)

    2012-07-06

    Greenhouse gas (CO{sub 2}, CH{sub 4} and N{sub 2}O, hereinafter GHG) and criteria air pollutant (CO, NO{sub x}, VOC, PM{sub 10}, PM{sub 2.5} and SO{sub x}, hereinafter CAP) emission factors for various types of power plants burning various fuels with different technologies are important upstream parameters for estimating life-cycle emissions associated with alternative vehicle/fuel systems in the transportation sector, especially electric vehicles. The emission factors are typically expressed in grams of GHG or CAP per kWh of electricity generated by a specific power generation technology. This document describes our approach for updating and expanding GHG and CAP emission factors in the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model developed at Argonne National Laboratory (see Wang 1999 and the GREET website at http://greet.es.anl.gov/main) for various power generation technologies. These GHG and CAP emissions are used to estimate the impact of electricity use by stationary and transportation applications on their fuel-cycle emissions. The electricity generation mixes and the fuel shares attributable to various combustion technologies at the national, regional and state levels are also updated in this document. The energy conversion efficiencies of electric generating units (EGUs) by fuel type and combustion technology are calculated on the basis of the lower heating values of each fuel, to be consistent with the basis used in GREET for transportation fuels. On the basis of the updated GHG and CAP emission factors and energy efficiencies of EGUs, the probability distribution functions (PDFs), which are functions that describe the relative likelihood for the emission factors and energy efficiencies as random variables to take on a given value by the integral of their own probability distributions, are updated using best-fit statistical curves to characterize the uncertainties associated with GHG and CAP emissions in life

  14. Virgin Islands: Coral Bay Watershed Management (A Former EPA CARE Project)

    Science.gov (United States)

    The Coral Bay Watershed Management is a recipient of the Level II CARE cooperative agreement to continue and expand its collective efforts to stop erosion, sediment, and storm-water pollution of Coral Bay, improve solid waste management,

  15. Distribution and sources of bioaccumulative air pollutants at Mezquital Valley, Mexico, as reflected by the atmospheric plant Tillandsia recurvata L.

    Science.gov (United States)

    Zambrano García, A.; Medina Coyotzin, C.; Rojas Amaro, A.; López Veneroni, D.; Martínez, L. Chang; Sosa Iglesias, G.

    2009-09-01

    Mezquital Valley (MV), a Mexican wastewater-based agricultural and industrial region, is a "hot spot" of regulated air pollutants emissions, but the concurrent unregulated ones, like hazardous metals and polycyclic aromatic hydrocarbons (PAH), remain undocumented. A biomonitoring survey with the epiphytic Tillandsia recurvata was conducted there to detect spatial patterns and potential sources of 20 airborne elements and 15 PAH. The natural δ13C and δ15N ratios of this plant helped in source identification. The regional mean concentration of most elements was two (Cr) to over 40 times (Ni, Pb, V) higher than reported for Tillandsia in other countries. Eleven elements, pyrene and chrysene had 18-214% higher mean concentration at the industrial south than at the agricultural north of MV. The total quantified PAH (mean, 572 ng g-1; range, 143-2568) were composed by medium (65%, phenanthrene to chrysene), low (28%, naphthalene to fluorene) and high molecular weight compounds (7%, Benzo(b)fluoranthene to indeno(1,2,3-cd)pyrene). The δ13C (mean, -14.6‰; range, -15.7‰ to -13.7‰) was consistently lower than -15‰ near the major petroleum combustion sources. The δ15N (mean, -3.0‰; range, -9.9‰ to 3.3‰) varied from positive at agriculture/industrial areas to negative at rural sites. Factor analysis provided a five-factor solution for 74% of the data variance: 1) crustal rocks, 39.5% (Al, Ba, Cu, Fe, Sr, Ti); 2) soils, 11.3%, contrasting contributions from natural (Mg, Mn, Zn) and saline agriculture soils (Na); 3) cement production and fossil fuel combustion, 9.8% (Ca, Ni, V, chrysene, pyrene); 4) probable agricultural biomass burning, 8.1% (K and benzo(g,h,i)perylene), and 5) agriculture with wastewater, 5.2% (δ15N and P). These results indicated high deposition of bioaccumulative air pollutants at MV, especially at the industrial area. Since T. recurvata reflected the regional differences in exposition, it is recommended as a biomonitor for comparisons

  16. Fate of airborne metal pollution in soils as related to agricultural management. 1. Zn and Pb distributions in soil profiles

    NARCIS (Netherlands)

    Fernandez, C.; Labanowski, J.; Cambier, P.; Jongmans, A.G.; Oort, van F.

    2007-01-01

    The fate of airborne metal pollutants in soils is still relatively unknown. We studied the incorporation of such airborne metal pollution in two soils under long-term permanent pasture (PP) and conventional arable land (CA). Both soils were located at an almost equal distance from a former zinc

  17. Watershed-scale modeling on the fate and transport of polycyclic aromatic hydrocarbons (PAHs)

    International Nuclear Information System (INIS)

    Ligaray, Mayzonee; Baek, Sang Soo; Kwon, Hye-Ok; Choi, Sung-Deuk; Cho, Kyung Hwa

    2016-01-01

    PAHs are potentially carcinogenic substances that are persistent in the environment. Increasing concentrations of PAHs were observed due to rapid urbanization, thus; monitoring PAHs concentrations is necessary. However, it is expensive to conduct intensive monitoring activities of a large number of PAHs. This study addressed this issue by developing a multimedia model coupled with a hydrological model (i.e., Soil and Water Assessment Tool (SWAT)) for Taehwa River (TR) watershed in Ulsan, the industrial capital of South Korea. The hydrologic module of the SWAT was calibrated, and further used to simulate the fate and transport of PAHs in soil and waterbody. The model demonstrated that the temporal or seasonal variation of PAHs in soil and waterbody can be well reproduced. Meanwhile, the spatial distribution of PAHs showed that urban areas in TR watershed have the highest PAH loadings compared to rural areas. Sensitivity analyses of the PAH soil and PAH water parameters were also able to determine the critical processes in TR watershed: degradation, deposition, volatilization, and wash off mechanism. We hope that this model will be able to aid the stakeholders in: regulating PAH concentrations emitted by various sources; and also apply the model to other Persistent Organic Pollutants (POPs).

  18. Watershed-scale modeling on the fate and transport of polycyclic aromatic hydrocarbons (PAHs)

    Energy Technology Data Exchange (ETDEWEB)

    Ligaray, Mayzonee; Baek, Sang Soo [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan 44919 (Korea, Republic of); Kwon, Hye-Ok [Disaster Scientific Investigation Division, National Disaster Management Research Institute, 365 Jongga-ro Jung-gu, Ulsan 44538 (Korea, Republic of); Choi, Sung-Deuk, E-mail: sdchoi@unist.ac.kr [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan 44919 (Korea, Republic of); Cho, Kyung Hwa, E-mail: khcho@unist.ac.kr [School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, UNIST-gil 50, Ulsan 44919 (Korea, Republic of)

    2016-12-15

    PAHs are potentially carcinogenic substances that are persistent in the environment. Increasing concentrations of PAHs were observed due to rapid urbanization, thus; monitoring PAHs concentrations is necessary. However, it is expensive to conduct intensive monitoring activities of a large number of PAHs. This study addressed this issue by developing a multimedia model coupled with a hydrological model (i.e., Soil and Water Assessment Tool (SWAT)) for Taehwa River (TR) watershed in Ulsan, the industrial capital of South Korea. The hydrologic module of the SWAT was calibrated, and further used to simulate the fate and transport of PAHs in soil and waterbody. The model demonstrated that the temporal or seasonal variation of PAHs in soil and waterbody can be well reproduced. Meanwhile, the spatial distribution of PAHs showed that urban areas in TR watershed have the highest PAH loadings compared to rural areas. Sensitivity analyses of the PAH soil and PAH water parameters were also able to determine the critical processes in TR watershed: degradation, deposition, volatilization, and wash off mechanism. We hope that this model will be able to aid the stakeholders in: regulating PAH concentrations emitted by various sources; and also apply the model to other Persistent Organic Pollutants (POPs).

  19. Variation of particle number size distributions and chemical compositions at the urban and downwind regional sites in the Pearl River Delta during summertime pollution episodes

    Science.gov (United States)

    Yue, D. L.; Hu, M.; Wu, Z. J.; Guo, S.; Wen, M. T.; Nowak, A.; Wehner, B.; Wiedensohler, A.; Takegawa, N.; Kondo, Y.; Wang, X. S.; Li, Y. P.; Zeng, L. M.; Zhang, Y. H.

    2010-10-01

    In order to characterize the features of particulate pollution in the Pearl River Delta (PRD) in the summer, continuous measurements of particle number size distributions and chemical compositions were simultaneously performed at Guangzhou urban site (GZ) and Back-garden downwind regional site (BG) in July 2006. Particle number concentration from 20 nm to 10 μm at BG was (1.7±0.8)×104 cm-3, about 40% lower than that at GZ, (2.9±1.1)×104 cm-3. The total particle volume concentration at BG was 94±34 μm3 cm-3, similar to that at GZ, 96±43 μm3 cm-3. More 20-100 nm particles, significantly affected by the traffic emissions, were observed at GZ, while 100-660 nm particle number concentrations were similar at both sites as they are more regional. PM2.5 values were similar at GZ (69±43 μg m-3) and BG (69±58 μg m-3) with R2 of 0.71 for the daily average PM2.5 at these two sites, indicating the fine particulate pollution in the PRD region to be regional. Two kinds of pollution episodes, the accumulation pollution episode and the regional transport pollution episode, were observed. Fine particles over 100 nm dominated both number and volume concentrations of total particles during the late periods of these pollution episodes. Accumulation and secondary transformation are the main reasons for the nighttime accumulation pollution episode. SO42-, NO3- accounted for about 60% in 100-660 nm particle mass and PM2.5 increase. When south or southeast wind prevailed in the PRD region, regional transport of pollutants took place. Regional transport contributed about 30% to fine particulate pollution at BG during a regional transport case. Secondary transformation played an important role during regional transport, causing higher increase rates of secondary ions in PM1.0 than other species and shifting the peaks of sulfate and ammonium mass size distributions to larger sizes. SO42-, NO3-, and NH4+ accounted for about 70% and 40% of PM1.0 and PM2.5, respectively.

  20. Spatiotemporal variation of watershed health propensity through reliability-resilience-vulnerability based drought index (case study: Shazand Watershed in Iran).

    Science.gov (United States)

    Sadeghi, Seyed Hamidreza; Hazbavi, Zeinab

    2017-06-01

    Quantitative response of the watershed health to climate variability is of critical importance for watershed managers. However, existing studies seldom considered the impact of climate variability on watershed health. The present study therefore aimed to analyze the temporal and spatial variability of reliability (R el ), resilience (R es ) and vulnerability (V ul ) indicators in node years of 1986, 1998, 2008 and 2014 in connection with Standardized Precipitation Index (SPI) for 24 sub-watersheds in the Shazand Watershed of Markazi Province in Iran. The analysis was based on rainfall variability as one of the main climatic drivers. To achieve the study purposes, the monthly rainfall time series of eight rain gauge stations distributed across the watershed or neighboring areas were analyzed and corresponding SPIs and R el R es V ul indicators were calculated. Ultimately, the spatial variation of SPI oriented R el R es V ul was mapped for the study watershed using Geographic Information System (GIS). The average and standard deviation of SPI-R el R es V ul index for the study years of 1986, 1998, 2008 and 2014 was obtained 0.240±0.025, 0.290±0.036, 0.077±0.0280 and 0.241±0.081, respectively. In overall, the results of the study proved the spatiotemporal variations of SPI-R el R es V ul watershed health index in the study area. Accordingly, all the sub-watersheds of the Shazand Watershed were grouped in unhealthy and very unhealthy conditions in all the study years. For 1986 and 1998 all the sub-watersheds were assessed in unhealthy status. Whilst, it declined to very unhealthy condition in 2008 and then some 75% of the watershed ultimately referred again to unhealthy and the rest still remained under very unhealthy conditions in 2014. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. [Distribution characteristic and assessment of soil heavy metal pollution in the iron mining of Baotou in Inner Mongolia].

    Science.gov (United States)

    Guo, Wei; Zhao, Ren-Xin; Zhang, Jun; Bao, Yu-Ying; Wang, Hong; Yang, Ming; Sun, Xiao-Li; Jin, Fan

    2011-10-01

    The pollution status and total concentration of soil heavy metals were analyzed around tailing reservoir of Baotou and iron mining of Bayan Obo located in Inner Mongolia grassland ecosystem. Aim of the study is to control soil heavy metal pollution of grassland mining area and provide the basic information. The results indicated that the soils from different directions of the tailing reservoir were contaminated by Pb, Cu, Zn and Mn. According to the single factor pollution index, the pollution degree was Mn > Zn > Pb > Cu. According to Nemerow integrated pollution index, the indexes of the northeast, southeast, southwest, and northwest of the tailing reservoir, were 2.43, 10.2, 1.88, 1.64. Soils from the southeast had the most serious heavy metal contamination because of the dominant wind of northwest. Within 50 m from the edge of tailing reservoir, heavy metal contamination was most serious except Cu. With regard to Bayan Obo iron mining, the single factor pollution index indicated that the soils from the six surveyed regions were contaminated by Pb, Cu, Zn and Mn. The integrated pollution index indicated that the indexes of the six regions, such as the mining area, the dump, outside the dump, outside the urban area, east region of the railway, and west region of the railway, were 14.3, 4.30, 2.69, 3.41, 2.88, and 2.20, respectively. The soil pollution degree of the mining area was the highest. Additionally, the transport of ore resulted in soil heavy metal pollution along railway. In general, soils of the two studied areas had the similar pollution characteristic, and the elements of heavy metal contamination were corresponding with the concentrations of tailings. The health and stabilization of grassland ecosystem are being threatened by soil heavy metals.

  2. Influence of the spatial discretization degree on the hydrological response of a flatland watershed through distributed mathematical modeling; Influencia del grado de discretizacion espacial en la respuesta hidrologica de una cuenca de llanura mediante modelacion matematica distribuida

    Energy Technology Data Exchange (ETDEWEB)

    Stenta, Herman Roberto; Riccardi, Gerardo A; Basile, Pedro A [Universidad Nacional de Rosario (Mexico)

    2008-07-15

    Distributed hydrological models are suitable for the determination of time and space variability of hydrological responses within a given watershed. In a watershed, the model can be implemented with different levels of space resolution, mainly as a function of data availability, objectives of the numerical study, and requirements of the system to be modeled. In this paper, the effects on landscape representation due to different cell sizes are analyzed and scaling of parameters in a lower spatial resolution level is proposed in order to obtain similarity in hydrological responses between different degrees of discretization. The comparison was made in terms of maximum discharge, maximum flow velocity, and maximum water depth by simulating a number of observed and hypothetical hydrological events. The concept of total equilibrium state of the watershed was used. Under these circumstances, the roughness coefficients associated to overland and stream flow and the storage function of each discretization element were adjusted separately for the lower spatial resolution level. The results show that the similarity in hydrological responses, in terms of maximum water depth, obtained by adjusting the storage function of the cells, is better than that corresponding to the adjustment of roughness coefficients. [Spanish] Los modelos matematicos de parametros distribuidos resultan particularmente apropiados para determinar la variabilidad espacial y temporal de las respuestas hidrologicas dentro de un determinado sistema hidrico. En una cuenca es posible realizar la constitucion de un modelo con diferentes niveles de detalle en funcion principalmente de la disponibilidad de informacion de entrada necesaria, de los objetivos de estudio y de los requerimientos de modelado del sistema. En el presente trabajo se analizan los efectos producidos en la representacion del relieve debido a los diferentes tamanos de celda en que se ha discretizado una cuenca de llanura y se propone el

  3. Watershed and Economic Data InterOperability (WEDO) System

    Science.gov (United States)

    Hydrologic modeling is essential for environmental, economic, and human health decision-making. However, sharing of modeling studies is limited within the watershed modeling community. Distribution of hydrologic modeling research typically involves publishing summarized data in p...

  4. Analysis of the Lake Superior Watershed Seasonal Snow Cover

    National Research Council Canada - National Science Library

    Daly, Steven F; Baldwin, Timothy B; Weyrick, Patricia

    2007-01-01

    Daily estimates of the snow water equivalent (SWE) distribution for the period from 1 December through 30 April for each winter season from 1979 80 through 2002 03 were calculated for the entire Lake Superior watershed...

  5. Impacts from Land Use Pattern on Spatial Distribution of Cultivated Soil Heavy Metal Pollution in Typical Rural-Urban Fringe of Northeast China.

    Science.gov (United States)

    Li, Wenbo; Wang, Dongyan; Wang, Qing; Liu, Shuhan; Zhu, Yuanli; Wu, Wenjun

    2017-03-22

    Under rapid urban sprawl in Northeast China, land conversions are not only encroaching on the quantity of cultivated lands, but also posing a great threat to black soil conservation and food security. This study's aim is to explore the spatial relationship between comprehensive cultivated soil heavy metal pollution and peri-urban land use patterns in the black soil region. We applied spatial lag regression to analyze the relationship between PLI (pollution load index) and influencing factors of land use by taking suburban cultivated land of Changchun Kuancheng District as an empirical case. The results indicate the following: (1) Similar spatial distribution characteristics are detected between Pb, Cu, and Zn, between Cr and Ni, and between Hg and Cd. The Yitong River catchment in the central region, and the residential community of Lanjia County in the west, are the main hotspots for eight heavy metals and PLI. Beihu Wetland Park, with a larger-area distribution of ecological land in the southeast, has low level for both heavy metal concentrations and PLI values. Spatial distribution characteristics of cultivated heavy metals are related to types of surrounding land use and industry; (2) Spatial lag regression has a better fit for PLI than the ordinary least squares regression. The regression results indicate the inverse relationship between heavy metal pollution degree and distance from long-standing residential land and surface water. Following rapid urban land expansion and a longer accumulation period, residential land sprawl is going to threaten cultivated land with heavy metal pollution in the suburban black soil region, and cultivated land irrigated with urban river water in the suburbs will have a higher tendency for heavy metal pollution.

  6. Impacts from Land Use Pattern on Spatial Distribution of Cultivated Soil Heavy Metal Pollution in Typical Rural-Urban Fringe of Northeast China

    Science.gov (United States)

    Li, Wenbo; Wang, Dongyan; Wang, Qing; Liu, Shuhan; Zhu, Yuanli; Wu, Wenjun

    2017-01-01

    Under rapid urban sprawl in Northeast China, land conversions are not only encroaching on the quantity of cultivated lands, but also posing a great threat to black soil conservation and food security. This study’s aim is to explore the spatial relationship between comprehensive cultivated soil heavy metal pollution and peri-urban land use patterns in the black soil region. We applied spatial lag regression to analyze the relationship between PLI (pollution load index) and influencing factors of land use by taking suburban cultivated land of Changchun Kuancheng District as an empirical case. The results indicate the following: (1) Similar spatial distribution characteristics are detected between Pb, Cu, and Zn, between Cr and Ni, and between Hg and Cd. The Yitong River catchment in the central region, and the residential community of Lanjia County in the west, are the main hotspots for eight heavy metals and PLI. Beihu Wetland Park, with a larger-area distribution of ecological land in the southeast, has low level for both heavy metal concentrations and PLI values. Spatial distribution characteristics of cultivated heavy metals are related to types of surrounding land use and industry; (2) Spatial lag regression has a better fit for PLI than the ordinary least squares regression. The regression results indicate the inverse relationship between heavy metal pollution degree and distance from long-standing residential land and surface water. Following rapid urban land expansion and a longer accumulation period, residential land sprawl is going to threaten cultivated land with heavy metal pollution in the suburban black soil region, and cultivated land irrigated with urban river water in the suburbs will have a higher tendency for heavy metal pollution. PMID:28327541

  7. Beyond formal groups: neighboring acts and watershed protection in Appalachia

    Directory of Open Access Journals (Sweden)

    Heather Lukacs

    2016-09-01

    Full Text Available This paper explores how watershed organizations in Appalachia have persisted in addressing water quality issues in areas with a history of coal mining. We identified two watershed groups that have taken responsibility for restoring local creeks that were previously highly degraded and sporadically managed. These watershed groups represent cases of self-organized commons governance in resource-rich, economically poor Appalachian communities. We describe the extent and characteristics of links between watershed group volunteers and watershed residents who are not group members. Through surveys, participant observation, and key-informant consultation, we found that neighbors – group members as well as non-group-members – supported the group's function through informal neighboring acts. Past research has shown that local commons governance institutions benefit from being nested in supportive external structures. We found that the persistence and success of community watershed organizations depends on the informal participation of local residents, affirming the necessity of looking beyond formal, organized groups to understand the resources, expertise, and information needed to address complex water pollution at the watershed level. Our findings augment the concept of nestedness in commons governance to include that of a formal organization acting as a neighbor that exchanges informal neighboring acts with local residents. In this way, we extend the concept of neighboring to include interactions between individuals and a group operating in the same geographic area.

  8. Spatial distribution and assessment of nutrient pollution in Lake Toba using 2D-multi layers hydrodynamic model and DPSIR framework

    Science.gov (United States)

    Sunaryani, A.; Harsono, E.; Rustini, H. A.; Nomosatryo, S.

    2018-02-01

    Lake Toba is the largest lake in Indonesia utilized as a source of life-support for drinking and clean water, energy sources, aquaculture and tourism. Nowadays the water quality in Lake Toba has decreased due to the presence of excessive nutrient (nitrogen: N and phosphorus: P). This study aims to describe the spatial distribution of nutrient pollution and to develop a decision support tool for the identification and evaluation of nutrient pollution control in Lake Toba. Spatial distribution method was conducted by 2D-multi layers hydrodynamic model, while DPSIR Framework is used as a tool for the assessment. The results showed that the concentration of nutrient was low and tended to increase along the water depth, but nutrient concentration in aquaculture zones was very high and the trophic state index has reached eutrophic state. The principal anthropogenic driving forces were population growth and the development of aquaculture, livestock, agriculture, and tourism. The main environmental pressures showed that aquaculture and livestock waste are the most important nutrient sources (93% of N and 87% of P loads). State analysis showed that high nutrient concentration and increased algal growth lead to oxygen depletion. The impacts of these conditions were massive fish kills, loss of amenities and tourism value, also decreased usability of clean water supply. This study can be a useful information for decision-makers to evaluate nutrient pollution control. Nutrient pollution issue in Lake Toba requires the attention of local government and public society to maintain its sustainability.

  9. Watershed Planning Basins

    Data.gov (United States)

    Vermont Center for Geographic Information — The Watershed Planning Basin layer is part of a larger dataset contains administrative boundaries for Vermont's Agency of Natural Resources. The dataset includes...

  10. Stormwater Impaired Watersheds

    Data.gov (United States)

    Vermont Center for Geographic Information — Stormwater impaired watersheds occuring on both the Priority Waters (Part D - Completed TMDL) and 303(d) list of waters (Part A - need TMDL) The Vermont State...

  11. Nitrogen component in nonpoint source pollution models

    Science.gov (United States)

    Pollutants entering a water body can be very destructive to the health of that system. Best Management Practices (BMPs) and/or conservation practices are used to reduce these pollutants, but understanding the most effective practices is very difficult. Watershed models are an effective tool to aid...

  12. Distributed hydrological modelling of total dissolved phosphorus transport in an agricultural landscape, part I: distributed runoff generation

    Directory of Open Access Journals (Sweden)

    P. Gérard-Marchant

    2006-01-01

    Full Text Available Successful implementation of best management practices for reducing non-point source (NPS pollution requires knowledge of the location of saturated areas that produce runoff. A physically-based, fully-distributed, GIS-integrated model, the Soil Moisture Distribution and Routing (SMDR model was developed to simulate the hydrologic behavior of small rural upland watersheds with shallow soils and steep to moderate slopes. The model assumes that gravity is the only driving force of water and that most overland flow occurs as saturation excess. The model uses available soil and climatic data, and requires little calibration. The SMDR model was used to simulate runoff production on a 164-ha farm watershed in Delaware County, New York, in the headwaters of New York City water supply. Apart from land use, distributed input parameters were derived from readily available data. Simulated hydrographs compared reasonably with observed flows at the watershed outlet over a eight year simulation period, and peak timing and intensities were well reproduced. Using off-site weather input data produced occasional missed event peaks. Simulated soil moisture distribution agreed well with observed hydrological features and followed the same spatial trend as observed soil moisture contents sampled on four transects. Model accuracy improved when input variables were calibrated within the range of SSURGO-available parameters. The model will be a useful planning tool for reducing NPS pollution from farms in landscapes similar to the Northeastern US.

  13. [Grain Size Distribution Characteristics of Suspended Particulate Matter as Influenced by the Apparent Pollution in the Eutrophic Urban Landscape Water Body].

    Science.gov (United States)

    Gong, Dan-yan; Pan, Yang; Huang, Yong; Bao, Wei; Li, Qian-qian

    2016-03-15

    Grain size distribution characteristics of suspended particulate matter (SPM) reflects the apparent polluted condition of the urban landscape water. In order to explore the internal relationship between the eutrophication of urban landscape water's apparent pollution and grain size distribution of SPM, and its influencing factors, this paper selected five representative sampling sites in Feng Jin River which is a typical eutrophication river in Suzhou City, measured the grain size distribution of SPM, sensation pollution index (SPI) and water quality index, and analyzed their correlation. The results showed that: The rich nutrient water possessed a similar characteristics in grain size distribution. The grain size distribution of SPM in water was multimodal, and the the peak position was roughly the same; the grain size distribution of SPM was composed by multiple components. It could be roughly divided into six parts with the particle size range of every group being 516 µm. The component III was superior (with an average volume fraction of 38.3%-43.2%), and its volume fraction had a significant positive relation with the SPI value and the Chl-a content. The increase of component III volume fraction was the reflection of particle size's result of increasing SPI value. The increase of component III volume fraction was mainly derived from the increasing algal content. The volume fraction of group IV + group VI + group V was significantly higher under the condition of exogenous enter. When there was no exogenous component, the volume fraction of group IV + group VI + group V had a significant negative correlation with SPI value; when there were exogenous components, the volume fraction of group IV + group VI + group V had a weak positive correlation with SPI value, but the correlation did not reach a significant level. Environmental factors (Fv/Fm and DO) and exogenous factors had an influence by functioning on the algal content which signified the polluted material

  14. Model Calibration in Watershed Hydrology

    Science.gov (United States)

    Yilmaz, Koray K.; Vrugt, Jasper A.; Gupta, Hoshin V.; Sorooshian, Soroosh

    2009-01-01

    Hydrologic models use relatively simple mathematical equations to conceptualize and aggregate the complex, spatially distributed, and highly interrelated water, energy, and vegetation processes in a watershed. A consequence of process aggregation is that the model parameters often do not represent directly measurable entities and must, therefore, be estimated using measurements of the system inputs and outputs. During this process, known as model calibration, the parameters are adjusted so that the behavior of the model approximates, as closely and consistently as possible, the observed response of the hydrologic system over some historical period of time. This Chapter reviews the current state-of-the-art of model calibration in watershed hydrology with special emphasis on our own contributions in the last few decades. We discuss the historical background that has led to current perspectives, and review different approaches for manual and automatic single- and multi-objective parameter estimation. In particular, we highlight the recent developments in the calibration of distributed hydrologic models using parameter dimensionality reduction sampling, parameter regularization and parallel computing.

  15. 75 FR 11837 - Chesapeake Bay Watershed Initiative

    Science.gov (United States)

    2010-03-12

    ... DEPARTMENT OF AGRICULTURE Commodity Credit Corporation Chesapeake Bay Watershed Initiative AGENCY...: Notice of availability of program funds for the Chesapeake Bay Watershed Initiative. SUMMARY: The... through the Chesapeake Bay Watershed Initiative for agricultural producers in the Chesapeake Bay watershed...

  16. Concentration distribution of NO2, PM10 and PM2,5 in severe pollution episodes in Oslo, Drammen, Bergen and Trondheim

    International Nuclear Information System (INIS)

    Sloerdal, Leiv Haavard; Toennesen, Dag

    1999-04-01

    Based on hourly model calculations of NO 2 , PM 1 0 and PM 2 ,5 through a 6 months winter season in the cities of Oslo, Drammen, Bergen and Trondheim, the 10 most severe pollution episodes have been analysed. Concentration distributions, calculated as the average of these episodes have been combined with the population distribution in order to reveal the exposure levels in such episodes. The model calculations have only been performed for the city background, i.e. on a km 2 grid system. (author)

  17. Anopheles gambiae distribution and insecticide resistance in the cities of Douala and Yaoundé (Cameroon): influence of urban agriculture and pollution.

    Science.gov (United States)

    Antonio-Nkondjio, Christophe; Fossog, Billy Tene; Ndo, Cyrille; Djantio, Benjamin Menze; Togouet, Serge Zebaze; Awono-Ambene, Parfait; Costantini, Carlo; Wondji, Charles S; Ranson, Hilary

    2011-06-08

    Urban malaria is becoming a major health priority across Africa. A study was undertaken to assess the importance of urban pollution and agriculture practice on the distribution and susceptibility to insecticide of malaria vectors in the two main cities in Cameroon. Anopheline larval breeding sites were surveyed and water samples analysed monthly from October 2009 to December 2010. Parameters analysed included turbidity, pH, temperature, conductivity, sulfates, phosphates, nitrates, nitrites, ammonia, aluminium, alkalinity, iron, potassium, manganese, magnesium, magnesium hardness and total hardness. Characteristics of water bodies in urban areas were compared to rural areas and between urban sites. The level of susceptibility of Anopheles gambiae to 4% DDT, 0.75% permethrin, 0.05% deltamethrin, 0.1% bendiocarb and 5% malathion were compared between mosquitoes collected from polluted, non polluted and cultivated areas. A total of 1,546 breeding sites, 690 in Yaoundé and 856 in Douala, were sampled in the course of the study. Almost all measured parameters had a concentration of 2- to 100-fold higher in urban compare to rural breeding sites. No resistance to malathion was detected, but bendiocarb resistance was present in Yaounde. Very low mortality rates were observed following DDT or permethrin exposure, associated with high kdr frequencies. Mosquitoes collected in cultivated areas, exhibited the highest resistant levels. There was little difference in insecticide resistance or kdr allele frequency in mosquitoes collected from polluted versus non-polluted sites. The data confirm high selection pressure on mosquitoes originating from urban areas and suggest urban agriculture rather than pollution as the major factor driving resistance to insecticide.

  18. Spatial distribution, temporal variation, and sources of heavy metal pollution in groundwater of a century-old nonferrous metal mining and smelting area in China.

    Science.gov (United States)

    Gong, Xing; Chen, Zhihua; Luo, Zhaohui

    2014-12-01

    This study first presents the spatial distribution, temporal variation, and sources of heavy metal pollution in groundwater of a nonferrous metal mine area in China. Unconfined groundwater was polluted by Pb, Zn, As, and Cu, in order, while confined karst water in the mines showed pollution in the following sequence: Zn, Cd, Cu, Pb, and As. Pollution by Pb was widespread, while Zn, As, Cu, and Cd were found to be high in the north-central industrial region and to decrease gradually with distance from smelters and tailings. Vertically, more Pb, Zn, Cu, and Cd have accumulated in shallow Quaternary groundwater, while more As have migrated into the deeper fracture groundwater in the local discharge area. Zn, Cd, and Cu concentrations in groundwater along the riverside diminished owing to reduced wastewater drainage since 1977, while samples in the confluence area were found to have increasing contents of Pb, Zn, As, Cu, and Cd since industrialization began in the 1990s. Sources of heavy metals in groundwater were of anthropogenic origin except for Cr. Pb originated primarily from airborne volatile particulates, wastewater, and waste residues and deposited continuously, while Zn, Cd, and Cu were derived from the wastewater of smelters and leakage of tailings, which corresponded to the related soil and surface residue researches. Elevated As values around factories might be the result of chemical reactions. Flow patterns in different hydrogeological units and adsorption capability of from Quaternary sediments restricted their cross-border diffusion.

  19. Spatial distribution of organic pollutants in industrial construction and demolition waste and their mutual interaction on an abandoned pesticide manufacturing plant.

    Science.gov (United States)

    Huang, Sheng; Zhao, Xin; Sun, Yanqiu; Ma, Jianli; Gao, Xiaofeng; Xie, Tian; Xu, Dongsheng; Yu, Yi; Zhao, Youcai

    2016-04-01

    A comprehensive field investigation of organic pollutants was examined in industrial construction and demolition waste (ICDW) inside an abandoned pesticide manufacturing plant. Concentrations of eight types of pesticides, a metabolite and two intermediates were studied. The ICDW was under severe and long-term contamination by organophosphorus, intermediates and pyrethroid pesticide with mean concentrations of 23,429, 3538 and 179.4 mg kg(-1), respectively. FT-IR analysis suggested that physical absorption and chemical bonding were their mutual interaction forms. Patterns of total pesticide spatial distribution showed good correlations with manufacturing processes spreading all over the plant both in enclosed workshops and in residues randomly dumped outside, while bricks and coatings were the most vulnerable to pollutants. Ultimately the fate of the OPPs was diversified as the immersion of ICDW in water largely transferred the pollutants into aquatic systems while exposure outside did not largely lead to pesticide degradation. The adoption of centralized collections for the disposal of wastes could only eliminate part of the contaminated ICDW, probably due to lack of knowledge and criteria. Correlation matrix and cluster analysis indicated that regulated disposal and management of polluted ICDW was effective, thus presenting the requirement for its appropriate disposal.

  20. [Spatial distribution and pollution assessment of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area, China ].

    Science.gov (United States)

    Zhang, Lei; Qin, Yan-wen; Ma, Ying-qun; Zhao, Yan-min; Shi, Yao

    2014-09-01

    The aim of this article was to explore the pollution level of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area. The contents and spatial distribution of As, Cd, Cr, Cu, Ph and Zn in surface water, suspended solids and surface sediments were analyzed respectively. The integrated pollution index and geoaccumulation index were used to evaluate the contamination degree of heavy metals in surface water and surface sediments respectively. The results indicated that the contents of heavy metals in surface water was in the order of Pb heavy metal contents in surface water increased from river to sea. Compared with the contents of heavy metals in surface water of the typical domestic estuary in China, the overall contents of heavy metals in surface water were at a higher level. The contents of heavy metals in suspended solids was in the order of Cd heavy metals in surface sediments was in the order of Cd heavy metals in water, suspended solids and sediment. In particular, the effects of salinity and suspended solids matter were most significant. The integrated pollution index assessment showed that the water quality was good except individual stations. The geoaccumulation index assessment showed that As was the major pollution element in surface sediments.

  1. Distributions, sources and pollution status of 17 trace metal/metalloids in the street dust of a heavily industrialized city of central China

    International Nuclear Information System (INIS)

    Li, Zhonggen; Feng, Xinbin; Li, Guanghui; Bi, Xiangyang; Zhu, Jianming; Qin, Haibo; Dai, Zhihui; Liu, Jinling; Li, Qiuhua; Sun, Guangyi

    2013-01-01

    A series of representative street dust samples were collected from a heavily industrialized city, Zhuzhou, in central China, with the aim to investigate the spatial distribution and pollution status of 17 trace metal/metalloid elements. Concentrations of twelve elements (Pb, Zn, Cu, Cd, Hg, As, Sb, In, Bi, Tl, Ag and Ga) were distinctly amplified by atmospheric deposition resulting from a large scale Pb/Zn smelter located in the northwest fringe of the city, and followed a declining trend towards the city center. Three metals (W, Mo and Co) were enriched in samples very close to a hard alloy manufacturing plant, while Ni and Cr appeared to derive predominantly from natural sources. Other industries and traffic had neglectable effects on the accumulation of observed elements. Cd, In, Zn, Ag and Pb were the five metal/metalloids with highest pollution levels and the northwestern part of city is especially affected by heavy metal pollution. -- Highlights: •Large-scale Pb/Zn smelters contributed to elevated trace elements in the street dust. •The hard alloy processing caused the enrichment of a few elements. •Cd, In, Zn, Ag and Pb were the most polluted elements. •Northwestern Zhuzhou suffered severe contamination for a range of trace elements. -- Pb/Zn smelting and hard alloy processing operations have caused seriously contamination of trace metal/metalloids in the street dust

  2. Effects of organic matter fraction and compositional changes on distribution of cadmium and zinc in long-term polluted paddy soils

    International Nuclear Information System (INIS)

    Zhou, Tong; Wu, Longhua; Luo, Yongming; Christie, Peter

    2018-01-01

    Soil particulate organic matter (POM) has rapid turnover and metal enrichment, but the interactions between organic matter (OM) and metals have not been well studied. The present study aimed to investigate changes in the OM concentration and composition of the POM fraction and their corresponding effects on metal distribution and extractability in long-term polluted paddy soils. Soil 2000–53 μm POM size fractions had higher contents of C–H and C=O bonds, C–H/C=O ratios and concentrations of fulvic acid (FA), humic acid (HA), cadmium (Cd) and zinc (Zn) than the bulk soils. Cadmium and Zn stocks in soil POM fractions were 24.5–27.9% and 7.12–16.7%, respectively, and were more readily EDTA-extractable. Compared with the control soil, the 2000–250 μm POM size fractions had higher organic carbon concentrations and C/N ratios in the polluted soils. However, there were no significant differences in the contents in C–H and C=O bonds or C–H/C=O ratios of POM fractions among the control, slightly and highly polluted soils. In accordance with the lower contents of C=O bonds and FA and HA concentrations, the Cd and Zn concentrations in 250–53 μm POM size fractions were lower than those in 2000–250 μm POM size fractions. Enrichment of Cd in POM fractions increased with increasing soil pollution level. These results support the view that changes in the OM concentration and the size and composition of POM fractions play a key role in determining the distribution of Cd and Zn in paddy soils. - Highlights: • The OC and FA contents and C/N in POM (2000–250 μm) increased in polluted soil. • Enrichment of Cd and Zn decreased with decreasing POM size. • No significant change in content of C=O group in POM was observed in polluted soil. • Changes in the size and composition of soil POM affected the Cd and Zn distribution. - Interactions between soil organic matter and metals.

  3. Jordan Lake Watershed Protection District

    Data.gov (United States)

    Town of Chapel Hill, North Carolina — Polygon representing the area of the Jordan Lake Watershed Protection District. The Watershed Protection District (PDF) is a sensitive area of land that drains to...

  4. Particle Pollution

    Science.gov (United States)

    ... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution — ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...

  5. Combining a finite mixture distribution model with indicator kriging to delineate and map the spatial patterns of soil heavy metal pollution in Chunghua County, central Taiwan

    International Nuclear Information System (INIS)

    Lin Yupin; Cheng Baiyou; Shyu, G.-S.; Chang, T.-K.

    2010-01-01

    This study identifies the natural background, anthropogenic background and distribution of contamination caused by heavy metal pollutants in soil in Chunghua County of central Taiwan by using a finite mixture distribution model (FMDM). The probabilities of contaminated area distribution are mapped using single-variable indicator kriging and multiple-variable indicator kriging (MVIK) with the FMDM cut-off values and regulation thresholds for heavy metals. FMDM results indicate that Cr, Cu, Ni and Zn can be individually fitted by a mixture model representing the background and contamination distributions of the four metals in soil. The FMDM cut-off values for contamination caused by the metals are close to the regulation thresholds, except for the cut-off value of Zn. The receiver operating characteristic (ROC) curve validates that indicator kriging and MVIK with FMDM cut-off values can reliably delineate heavy metals contamination, particularly for areas lacking background information and high heavy metal concentrations in soil. - Effectively determine pollution threshold and map contaminated areas.

  6. Scenario analysis of the impacts of socioeconomic development on phosphorous export and loading from the Dongting Lake watershed, China.

    Science.gov (United States)

    Hou, Ying; Chen, Weiping; Liao, Yuehua; Luo, Yueping

    2017-12-01

    Socioeconomic development in lake watersheds is closely related with lake nutrient pollution. As the second largest freshwater lake in China, the Dongting Lake has been experiencing an increase in nutrient loading and a growing risk of eutrophication. This study aimed to reveal the likely impacts of the socioeconomic development of the Dongting Lake watershed on the phosphorous pollution in the lake. We estimated the contributions from different sources and sub-watersheds to the total phosphorous (TP) export and loading from the Dongting Lake watershed under two most likely socioeconomic development scenarios. Moreover, we predicted the likely permissible and actual TP loadings to the Dongting Lake. Under both two scenarios, three secondary sub-watersheds-the upper and lower reaches of the Xiang River watershed and the Dongting Lake Area-are expected to dominate the contribution to the TP export from the Dongting Lake watershed in 2020. Three primary sub-watersheds-the Dongting Lake Area, the Xiang River, and the Yuan River watersheds-are predicted to be the major contributors to the TP loading from the entire watershed. The two scenarios are expected to have a slight difference in TP export and lake TP loading. Livestock husbandry is expected to be the predominant anthropogenic TP source in each of the sub-watersheds under both scenarios. Compared to 2010, permissible TP loading is not expected to increase but actual TP loading is predicted to grow significantly in 2020. Our study provides methodologies to identify the key sources and regions of lake nutrient loading from watersheds with complex socioeconomic context, and to reveal the potential influences of socioeconomic development on nutrient pollution in lake watersheds.

  7. Uncertainty in BMP evaluation and optimization for watershed management

    Science.gov (United States)

    Chaubey, I.; Cibin, R.; Sudheer, K.; Her, Y.

    2012-12-01

    Use of computer simulation models have increased substantially to make watershed management decisions and to develop strategies for water quality improvements. These models are often used to evaluate potential benefits of various best management practices (BMPs) for reducing losses of pollutants from sources areas into receiving waterbodies. Similarly, use of simulation models in optimizing selection and placement of best management practices under single (maximization of crop production or minimization of pollutant transport) and multiple objective functions has increased recently. One of the limitations of the currently available assessment and optimization approaches is that the BMP strategies are considered deterministic. Uncertainties in input data (e.g. precipitation, streamflow, sediment, nutrient and pesticide losses measured, land use) and model parameters may result in considerable uncertainty in watershed response under various BMP options. We have developed and evaluated options to include uncertainty in BMP evaluation and optimization for watershed management. We have also applied these methods to evaluate uncertainty in ecosystem services from mixed land use watersheds. In this presentation, we will discuss methods to to quantify uncertainties in BMP assessment and optimization solutions due to uncertainties in model inputs and parameters. We have used a watershed model (Soil and Water Assessment Tool or SWAT) to simulate the hydrology and water quality in mixed land use watershed located in Midwest USA. The SWAT model was also used to represent various BMPs in the watershed needed to improve water quality. SWAT model parameters, land use change parameters, and climate change parameters were considered uncertain. It was observed that model parameters, land use and climate changes resulted in considerable uncertainties in BMP performance in reducing P, N, and sediment loads. In addition, climate change scenarios also affected uncertainties in SWAT

  8. Pollution distribution in floodplain structure visualised by electrical resistivity imaging in the floodplain of the Litavka River, the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Faměra, Martin; Kotková, Kristýna; Tůmová, Štěpánka; Elznicová, J.; Matys Grygar, Tomáš

    2018-01-01

    Roč. 165, JUN (2018), s. 157-172 ISSN 0341-8162 R&D Projects: GA ČR(CZ) GA15-00340S Institutional support: RVO:61388980 Keywords : Electric resistivity * Floodplain structure * Geophysical methods * Pollution chemostratigraphy * Post-depositional migration * Shallow subsurface Subject RIV: DD - Geochemistry OBOR OECD: Geology Impact factor: 3.191, year: 2016

  9. Impacts of long-term waste-water irrigation on the development of sandy Luvisols: consequences for metal pollutant distributions

    NARCIS (Netherlands)

    Oort, van F.; Jongmans, A.G.; Lamy, I.; Baize, D.; Chevallier, P.

    2008-01-01

    Studies relating macro- and microscopic aspects of impacts of long-term contaminative practices on soils are scarce. We performed such an approach by assessing the fate of metal pollutants in an area close to Paris, where sandy Luvisols were irrigated for 100 years with urban waste water. As a

  10. Multi-phase distribution and comprehensive ecological risk assessment of heavy metal pollutants in a river affected by acid mine drainage.

    Science.gov (United States)

    Liao, Jianbo; Ru, Xuan; Xie, Binbin; Zhang, Wanhui; Wu, Haizhen; Wu, Chaofei; Wei, Chaohai

    2017-07-01

    To date, there is a lack of a comprehensive research on heavy metals detection and ecological risk assessment in river water, sediments, pore water (PW) and suspended solids (SS). Here, the concentrations of heavy metals, including Cu, Zn, Mn, Cd, Pb and As, and their distribution between the four phases was studied. Samples for analysis were taken from twelve sites of the Hengshi River, Guangdong Province, China, during the rainy and dry seasons. A new comprehensive ecological risk index (CERI) based on considering metal contents, pollution indices, toxicity coefficients and water categories is offered for prediction of potential risk on aquatic organisms. The results of comprehensive analysis showed that the highest concentrations of Cu, Zn and Mn of 6.42, 87.17 and 98.74mg/L, respectively, in PW were comparable with those in water, while concentrations of Cd, Pb and As of 609.5, 2757 and 96.38μg/L, respectively, were 2-5 times higher. The sum of the exchangeable and carbonate fractions of target metals in sediments followed the order of Cd > Mn > Zn > Pb > Cu > As. The distribution of heavy metals in phases followed the order of sediment > SS > water > PW, having the sum content in water and PW lower than 2% of total. The elevated ecological risk for a single metal and the phase were 34,585 for Cd and 1160 for water, respectively, implied Cd as a priority pollutant in the considered area. According to the CERI, the maximum risk value of 769.3 was smaller than 1160 in water, but higher than those in other phases. Out of considering the water categories and contribution coefficients, the CERI was proved to be more reliable for assessing the pollution of rivers with heavy metals. These results imply that the CERI has a potential of adequate assessment of multi-phase composite metals pollution. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Watershed assessment-watershed analysis: What are the limits and what must be considered

    Science.gov (United States)

    Robert R. Ziemer

    2000-01-01

    Watershed assessment or watershed analysis describes processes and interactions that influence ecosystems and resources in a watershed. Objectives and methods differ because issues and opportunities differ.

  12. Assessment of heavy metal pollution, spatial distribution and origin in agricultural soils along the Sinú River Basin, Colombia.

    Science.gov (United States)

    Marrugo-Negrete, José; Pinedo-Hernández, José; Díez, Sergi

    2017-04-01

    The presence of metals in agricultural soils from anthropogenic activities such as mining and agricultural use of metals and metal-containing compounds is a potential threat for human health through the food chain. In this study, the concentration of heavy metals in 83 agricultural soils irrigated by the Sinú River, in northern Colombia, affected by mining areas upstream and inundated during seasonal floods events were determined to evaluate their sources and levels of pollution. The average concentrations of Cu, Ni, Pb, Cd, Hg and Zn were 1149, 661, 0.071, 0.040, 0.159 and 1365mg/kg respectively and exceeded the world normal averages, with the exception of Pb and Cd. Moreover, all values surpassed the background levels of soils in the same region. Soil pollution assessment was carried out using contamination factor (CF), enrichment factor (EF), geoaccumulation index (Igeo) and a risk assessment code (RAC). According to these indexes, the soils show a high degree of pollution of Ni and a moderate to high contamination of Zn and Cu; whereas, Pb, Cd and Hg present moderate pollution. However, based on the RAC index, a low environmental risk is found for all the analysed heavy metals. Multivariate statistical analyses, principal component and cluster analyses, suggest that soil contamination was mainly derived from agricultural practices, except for Hg, which was caused probably by atmospheric and river flow transport from upstream gold mining. Finally, high concentrations of Ni indicate a mixed pollution source from agricultural and ferronickel mining activities. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. 75 FR 27552 - Guidance for Federal Land Management in the Chesapeake Bay Watershed

    Science.gov (United States)

    2010-05-17

    ... will allow the federal government to lead the way in protecting the Bay and its watershed with the most effective tools and practices available to reduce water pollution from a variety of nonpoint sources... describe ``proven cost-effective tools and practices that reduce water pollution'' that are appropriate to...

  14. Assessing critical source areas in watersheds for conservation buffer planning and riparian restoration.

    Science.gov (United States)

    Qiu, Zeyuan

    2009-11-01

    A science-based geographic information system (GIS) approach is presented to target critical source areas in watersheds for conservation buffer placement. Critical source areas are the intersection of hydrologically sensitive areas and pollutant source areas in watersheds. Hydrologically sensitive areas are areas that actively generate runoff in the watershed and are derived using a modified topographic index approach based on variable source area hydrology. Pollutant source areas are the areas in watersheds that are actively and intensively used for such activities as agricultural production. The method is applied to the Neshanic River watershed in Hunterdon County, New Jersey. The capacity of the topographic index in predicting the spatial pattern of runoff generation and the runoff contribution to stream flow in the watershed is evaluated. A simple cost-effectiveness assessment is conducted to compare the conservation buffer placement scenario based on this GIS method to conventional riparian buffer scenarios for placing conservation buffers in agricultural lands in the watershed. The results show that the topographic index reasonably predicts the runoff generation in the watershed. The GIS-based conservation buffer scenario appears to be more cost-effective than the conventional riparian buffer scenarios.

  15. Water quality trading opportunities in two sub-watersheds in the northern Lake Okeechobee watershed.

    Science.gov (United States)

    Corrales, Juliana; Naja, G Melodie; Bhat, Mahadev G; Miralles-Wilhelm, Fernando

    2017-07-01

    For decades, the increase of nutrient enrichment has threatened the ecological integrity and economic sustainability of many rivers, lakes, and coastal waters, including Lake Okeechobee, the second largest freshwater lake in the contiguous United States. Water quality trading programs have been an area of active development to both, reduce nutrient pollution and minimize abatement costs. The objective of this study was to apply a comprehensive modeling framework, integrating a hydrologic-water quality model with an economic model, to assess and compare the cost-effectiveness of a water quality trading program over a command-and-control approach in order to reduce phosphorus loadings to Lake Okeechobee. The Upper Kissimmee (UK) and Taylor Creek/Nubbin Slough (TCNS) sub-watersheds, identified as major sources of total phosphorus (TP) loadings to the lake, were selected for this analysis. The effect of different caps on the market potential was assessed while considering four factors: the least-cost abatement solutions, credit prices, potential cost savings, and credit supply and demand. Hypothetical trading scenarios were also developed, using the optimal caps selected for the two sub-watersheds. In both sub-watersheds, a phosphorus credit trading program was less expensive than the conventional command-and-control approach. While attaining cost-effectiveness, keeping optimal credit prices, and fostering market competition, phosphorus reduction targets of 46% and 32% were selected as the most appropriate caps in the UK and TCNS sub-watersheds, respectively. Wastewater treatment facilities and urban areas in the UK, and concentrated animal feeding operations in the TCNS sub-watershed were identified as potential credit buyers, whereas improved pastures were identified as the major credit sellers in both sub-watersheds. The estimated net cost savings resulting from implementing a phosphorus trading program in the UK and TCNS sub-watersheds were 76% ($ 34.9 million per

  16. Optimal pollution trading without pollution reductions

    Science.gov (United States)

    Many kinds of water pollution occur in pulses, e.g., agricultural and urban runoff. Ecosystems, such as wetlands, can serve to regulate these pulses and smooth pollution distributions over time. This smoothing reduces total environmental damages when “instantaneous” damages are m...

  17. Allegheny County Watershed Boundaries

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset demarcates the 52 isolated sub-Watersheds of Allegheny County that drain to single point on the main stem rivers. Created by 3 Rivers 2nd Nature based...

  18. Fundamentals of watershed hydrology

    Science.gov (United States)

    Pamela J. Edwards; Karl W.J. Williard; Jon E. Schoonover

    2015-01-01

    This is a primer about hydrology, the science of water. Watersheds are the basic land unit for water resource management and their delineation, importance, and variation are explained and illustrated. The hydrologic cycle and its components (precipitation, evaporation, transpiration, soil water, groundwater, and streamflow) which collectively provide a foundation for...

  19. AUTOMATED GEOSPATIAL WATERSHED ASSESSMENT ...

    Science.gov (United States)

    The Automated Geospatial Watershed Assessment tool (AGWA) is a GIS interface jointly developed by the USDA Agricultural Research Service, the U.S. Environmental Protection Agency, the University of Arizona, and the University of Wyoming to automate the parameterization and execution of the Soil Water Assessment Tool (SWAT) and KINEmatic Runoff and EROSion (KINEROS2) hydrologic models. The application of these two models allows AGWA to conduct hydrologic modeling and watershed assessments at multiple temporal and spatial scales. AGWA’s current outputs are runoff (volumes and peaks) and sediment yield, plus nitrogen and phosphorus with the SWAT model. AGWA uses commonly available GIS data layers to fully parameterize, execute, and visualize results from both models. Through an intuitive interface the user selects an outlet from which AGWA delineates and discretizes the watershed using a Digital Elevation Model (DEM) based on the individual model requirements. The watershed model elements are then intersected with soils and land cover data layers to derive the requisite model input parameters. The chosen model is then executed, and the results are imported back into AGWA for visualization. This allows managers to identify potential problem areas where additional monitoring can be undertaken or mitigation activities can be focused. AGWA also has tools to apply an array of best management practices. There are currently two versions of AGWA available; AGWA 1.5 for

  20. Watersheds in disordered media

    Directory of Open Access Journals (Sweden)

    José S. Andrade Jr.

    2015-02-01

    Full Text Available What is the best way to divide a rugged landscape? Since ancient times, watershedsseparating adjacent water systems that flow, for example, toward different seas, have beenused to delimit boundaries. Interestingly, serious and even tense border disputes betweencountries have relied on the subtle geometrical properties of these tortuous lines. For instance,slight and even anthropogenic modifications of landscapes can produce large changes in awatershed, and the effects can be highly nonlocal. Although the watershed concept arisesnaturally in geomorphology, where it plays a fundamental role in water management, landslide,and flood prevention, it also has important applications in seemingly unrelated fields suchas image processing and medicine. Despite the far-reaching consequences of the scalingproperties on watershed-related hydrological and political issues, it was only recently that a moreprofound and revealing connection has been disclosed between the concept of watershed andstatistical physics of disordered systems. This review initially surveys the origin and definition of awatershed line in a geomorphological framework to subsequently introduce its basic geometricaland physical properties. Results on statistical properties of watersheds obtained from artificialmodel landscapes generated with long-range correlations are presented and shown to be ingood qualitative and quantitative agreement with real landscapes.

  1. Watershed hydrology. Chapter 7.

    Science.gov (United States)

    Elons S. Verry; Kenneth N. Brooks; Dale S. Nichols; Dawn R. Ferris; Stephen D. Sebestyen

    2011-01-01

    Watershed hydrology is determined by the local climate, land use, and pathways of water flow. At the Marcell Experimental Forest (MEF), streamflow is dominated by spring runoff events driven by snowmelt and spring rains common to the strongly continental climate of northern Minnesota. Snowmelt and rainfall in early spring saturate both mineral and organic soils and...

  2. The experimental watersheds in Slovenia

    International Nuclear Information System (INIS)

    Sraj, M; Rusjan, S; Petan, S; Vidmar, A; Mikos, M; Globevnik, L; Brilly, M

    2008-01-01

    Experimental watersheds are critical to the advancement of hydrological science. By setting up three experimental watersheds, Slovenia also obtained its grounds for further development of the science and discipline. In the Dragonja experimental watershed the studies are focused on the afforestation of the watershed in a mediterranean climate, on the Reka river the water balance in a partly karstic area is examined, and on the case of the Glinscica stream the implications of the urban environment are studied. We have obtained valuable experience and tested new measuring equipment on all three experimental watersheds. Measurements and analysis on the experimental watersheds improved the current understanding of hydrological processes. They resulted in several PhD Theses, Master Theses and scientific articles. At the same time the experimental watersheds provide support to the teaching and studying process.

  3. Rare earth elements determination and distribution patterns in sediments of polluted marine environment by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Akyil, S.; Yusof, A.M.; Wood, A.K.H.

    2001-01-01

    Results obtained from the analysis of sediment core samples taken from a fairly polluted marine environment were analyzed for the REE contents to determine the concentrations of La, Ce, Sm, Eu, Tb, Dy and Yb using instrumental neutron activation analysis. Core samples were divided into strata of between 2 to 3 cm intervals and prepared in the powdered form before irradiating them in a TRIGA Mk.II reactor. Down-core concentration profiles of La, Ce, Sm, Eu, Tb, Dy and Yb in 3 core sediments from three sites are obtained. The shale-normalized REE pattern from each site was examined and later used to explain the history of sedimentation by natural processes such as shoreline erosion and weathering products deposited on the seabed and furnishing some baseline data and/or pollution trend occurring within the study area

  4. GIBSI: an integrated modelling system for watershed management – sample applications and current developments

    Directory of Open Access Journals (Sweden)

    A. N. Rousseau

    2007-11-01

    Full Text Available Hydrological and pollutant fate models have long been developed for research purposes. Today, they find an application in integrated watershed management, as decision support systems (DSS. GIBSI is such a DSS designed to assist stakeholders in watershed management. It includes a watershed database coupled to a GIS and accessible through a user-friendly interface, as well as modelling tools that simulate, on a daily time step, hydrological processes such as evapotranspiration, runoff, soil erosion, agricultural pollutant transport and surface water quality. Therefore, GIBSI can be used to assess a priori the effect of management scenarios (reservoirs, land use, waste water effluents, diffuse sources of pollution that is agricultural pollution on surface hydrology and water quality. For illustration purposes, this paper presents several management-oriented applications using GIBSI on the 6680 km2 Chaudière River watershed, located near Quebec City (Canada. They include impact assessments of: (i municipal clean water program; (ii agricultural nutrient management scenarios; (iii past and future land use changes, as well as (iv determination of achievable performance standards of pesticides management practices. Current and future developments of GIBSI are also presented as these will extend current uses of this tool and make it useable and applicable by stakeholders on other watersheds. Finally, the conclusion emphasizes some of the challenges that remain for a better use of DSS in integrated watershed management.

  5. Determination of Water Quality Status at Sampean Watershed Bondowoso Residence Using Storet Method

    Science.gov (United States)

    Sugiyarto; Hariono, B.; Destarianto, P.; Nuruddin, M.

    2018-01-01

    Sampean watershed has an important social and economic function for the people surroundings. Sampean watershed wich cover Bondowoso and Situbondo residence is an urban watershed that has strategic value for national context needs special traetment. Construction activity at upper and lower course of Sampean watershed is highly intensive and growth of inhabitant also increase. The change of land utilization and increase of settlement area at upper, midlle, and lower course caused polutant infiltration to Sampean river watershed so it has impact on water quality. The source of pollution at Sampean river comes from domestic waste, industrial waste, agricultural waste and animal husbandry waste. The purpose of this research is to determine load of pollution and analize the pollution load carrying capacity at Sampean watershed. The data used in this research are rainfall, river flow rate and water quality at 6 certain points within 3 years during 2014 until 2016. The method to determine overall pollution rate is STORET (Storage and Retrieval of Water Quality Data System) method. The analysis results for the first, second, third and forth grade are -24 (moderate quality), -12 (moderate quality), -2 (good quality), and 0 (good quality) respectively.

  6. Vertical distribution of elements in non-polluted estuarine sediments determined by neutron induced prompt gamma-ray and instrumental neutron activation analyses

    International Nuclear Information System (INIS)

    Kuno, A.; Sampei, K.; Matsuo, M.; Sawahata, H.

    1999-01-01

    Neutron induced prompt gamma-ray analysis (PGA) and instrumental neutron activation analysis (INAA) have been applied to the sediments collected from the Yasaka River estuary in Oita Prefecture, Japan. The vertical distribution of 33 elements in the sediments has been determined and compared with that in more polluted estuarine sediments. While the S content increased with increasing depth because of a sulphide accumulation under reducing condition, the increase in sulphide-forming elements such as Ag, Cd, Co and Zn was not observed in the deeper section of the Yasaka River estuarine sediments. (author)

  7. Assessment of heavy metal pollution, distribution and source apportionment in the sediment from Feni River estuary, Bangladesh.

    Science.gov (United States)

    Islam, Md Saiful; Hossain, M Belal; Matin, Abdul; Islam Sarker, Md Shafiqul

    2018-07-01

    Heavy metal pollution in sediment resources may pose serious threat to ecosystem and human health through food web. In this study, surface sediment samples of 10 stations along the Feni River estuary were analyzed to profile the accumulation, sources and pollution levels of heavy metals. The results revealed that the average contents (μg g -1 ) of eight selected heavy metals followed the order of Mn (37.85) > Cr (35.28) > Ni (33.27) > Co (31.02) > Pb (6.47) > Ag (1.09) > As (0.85) > Hg (0.71), and the concentrations varied spatially and seasonally with relatively higher levels at upward stations and during the rainy season. According to sediment quality guidelines (SQGs), the sediment samples were heavily contaminated with Ag and Hg, and moderately with Co. Threshold effect concentration (TEC) and probable effect concentration (PEC) values indicated that the concentration of only Ni and Cr were likely to occasionally exhibit adverse effects on the ecosystem. Enrichment factor (EF), geo-accumulation index (I geo ) and contamination factor (CF) analyses revealed that Ag, Co and Hg were at moderate to high pollution levels and the rests (As, Cr, Ni, Pb and Mn) were at no to low pollution levels. Potential ecological risk index (PERI) also showed that Ag, Co and Hg were the most potential ecological risk factor being determined in this studied area. Correlation matrix combined with multivariate principal component analysis and cluster analysis suggest that Ag, Co, Ni and Hg originated from anthropogenic sources (agrochemicals, silver nanoparticles anti-microbial agent, silver plating), whereas As, Cr, Pb and Mn primarily originated from natural geological background. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Benthic foraminifera distribution in high polluted sediments from Niterói Harbor (Guanabara Bay), Rio de Janeiro, Brazil

    OpenAIRE

    Claudia G. Vilela; Daniele S. Batista; José A. Batista-Neto; Mirian Crapez; John J. Mcallister

    2004-01-01

    Dockyards and harbors are recognized as being important locations where sediment-associated pollutants can accumulate, which constitutes an environmental risk to aquatic life due to potential uptake and accumulation of heavy metals in the biota. The aim of this paper is to assess the concentrations and the effects of some heavy metals in the benthic foraminifera assemblage in Niterói Harbor. Low concentrations in the benthic foraminifera as well as the dominance of indicative species such as ...

  9. Nitrate source apportionment in a subtropical watershed using Bayesian model

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Liping; Han, Jiangpei; Xue, Jianlong; Zeng, Lingzao [College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058 (China); Shi, Jiachun, E-mail: jcshi@zju.edu.cn [College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058 (China); Wu, Laosheng, E-mail: laowu@zju.edu.cn [College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058 (China); Jiang, Yonghai [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012 (China)

    2013-10-01

    Nitrate (NO{sub 3}{sup −}) pollution in aquatic system is a worldwide problem. The temporal distribution pattern and sources of nitrate are of great concern for water quality. The nitrogen (N) cycling processes in a subtropical watershed located in Changxing County, Zhejiang Province, China were greatly influenced by the temporal variations of precipitation and temperature during the study period (September 2011 to July 2012). The highest NO{sub 3}{sup −} concentration in water was in May (wet season, mean ± SD = 17.45 ± 9.50 mg L{sup −1}) and the lowest concentration occurred in December (dry season, mean ± SD = 10.54 ± 6.28 mg L{sup −1}). Nevertheless, no water sample in the study area exceeds the WHO drinking water limit of 50 mg L{sup −1} NO{sub 3}{sup −}. Four sources of NO{sub 3}{sup −} (atmospheric deposition, AD; soil N, SN; synthetic fertilizer, SF; manure and sewage, M and S) were identified using both hydrochemical characteristics [Cl{sup −}, NO{sub 3}{sup −}, HCO{sub 3}{sup −}, SO{sub 4}{sup 2−}, Ca{sup 2+}, K{sup +}, Mg{sup 2+}, Na{sup +}, dissolved oxygen (DO)] and dual isotope approach (δ{sup 15}N–NO{sub 3}{sup −} and δ{sup 18}O–NO{sub 3}{sup −}). Both chemical and isotopic characteristics indicated that denitrification was not the main N cycling process in the study area. Using a Bayesian model (stable isotope analysis in R, SIAR), the contribution of each source was apportioned. Source apportionment results showed that source contributions differed significantly between the dry and wet season, AD and M and S contributed more in December than in May. In contrast, SN and SF contributed more NO{sub 3}{sup −} to water in May than that in December. M and S and SF were the major contributors in December and May, respectively. Moreover, the shortcomings and uncertainties of SIAR were discussed to provide implications for future works. With the assessment of temporal variation and sources of NO{sub 3}{sup −}, better

  10. Nitrate source apportionment in a subtropical watershed using Bayesian model

    International Nuclear Information System (INIS)

    Yang, Liping; Han, Jiangpei; Xue, Jianlong; Zeng, Lingzao; Shi, Jiachun; Wu, Laosheng; Jiang, Yonghai

    2013-01-01

    Nitrate (NO 3 − ) pollution in aquatic system is a worldwide problem. The temporal distribution pattern and sources of nitrate are of great concern for water quality. The nitrogen (N) cycling processes in a subtropical watershed located in Changxing County, Zhejiang Province, China were greatly influenced by the temporal variations of precipitation and temperature during the study period (September 2011 to July 2012). The highest NO 3 − concentration in water was in May (wet season, mean ± SD = 17.45 ± 9.50 mg L −1 ) and the lowest concentration occurred in December (dry season, mean ± SD = 10.54 ± 6.28 mg L −1 ). Nevertheless, no water sample in the study area exceeds the WHO drinking water limit of 50 mg L −1 NO 3 − . Four sources of NO 3 − (atmospheric deposition, AD; soil N, SN; synthetic fertilizer, SF; manure and sewage, M and S) were identified using both hydrochemical characteristics [Cl − , NO 3 − , HCO 3 − , SO 4 2− , Ca 2+ , K + , Mg 2+ , Na + , dissolved oxygen (DO)] and dual isotope approach (δ 15 N–NO 3 − and δ 18 O–NO 3 − ). Both chemical and isotopic characteristics indicated that denitrification was not the main N cycling process in the study area. Using a Bayesian model (stable isotope analysis in R, SIAR), the contribution of each source was apportioned. Source apportionment results showed that source contributions differed significantly between the dry and wet season, AD and M and S contributed more in December than in May. In contrast, SN and SF contributed more NO 3 − to water in May than that in December. M and S and SF were the major contributors in December and May, respectively. Moreover, the shortcomings and uncertainties of SIAR were discussed to provide implications for future works. With the assessment of temporal variation and sources of NO 3 − , better agricultural management practices and sewage disposal programs can be implemented to sustain water quality in subtropical watersheds

  11. Nutrient Reduction in Agricultural Green Infrastructure: An Analysis of the Raccoon River Watershed

    Directory of Open Access Journals (Sweden)

    James F. Canning

    2018-06-01

    Full Text Available Agricultural intensification has had the undesirable effect of degrading water quality throughout the United States. Nitrate pollution presents a difficult problem for rural and urban communities, and it contributes to the immense Gulf of Mexico Hypoxia Zone. Current U.S. policy prohibits regulation of agricultural runoff because it is a nonpoint source. The Raccoon River Watershed upstream of Des Moines, Iowa, USA has some of the highest nitrate levels in the nation, and the drinking water utility in Des Moines unsuccessfully pursued litigation against drainage districts in the watershed. We propose a cooperative solution between urban residents and upstream rural residents—namely, the installation of agricultural green infrastructure in the form of riparian buffers throughout the watershed enabled by the principles of water quality trading. We compare this distributed, green approach with a centralized, gray approach (i.e., building a new nitrate removal facility at the drinking water utility. Using terrain analysis, we determined that first-order streams are the most fitting location for riparian buffers. We estimate the buffer installation to cost between $155–$185 million; maintenance of the current nitrate removal facility will cost $72 million, while a new facility could cost up to $184 million. Riparian buffer installation offers more indirect, non-quantified benefits than maintaining or building new centralized, gray treatment (e.g., living-wage jobs and in-stream water quality improvement. Our analysis could act as a model for water quality trading and distributed agricultural green infrastructure in other communities facing similar water quality challenges.

  12. Regional Ecological Risk Assessment in the Huai River Watershed during 2010–2015

    Directory of Open Access Journals (Sweden)

    Yan Lu

    2017-12-01

    Full Text Available Ecosystem deterioration has been and is still a serious threat to human survival and regional economic development. Theoretical and methodological challenges exist in assessing ecological risk of watershed ecosystem that is imposed by natural changes or human activities. To fill this research gap, this research proposes an interdisciplinary and quantitative methodology based on some techniques such as the Procedure for Ecological Tiered Assessment of Risk (PETAR, the Entropy, and the Celluar Automata Markov (CA-Markov. We focused on six vulnerable environmental variables, namely land-use change, water quantity, water quality, gross domestic product (GDP, environmental pollutants, and soil erosion in the Huai River watershed in the Henan Province in order to build multi-dimensional quantitative method. Further, the Coupling Coordination Degree Model is constructed, and the “threshold index” is also addressed to reflect the limitation of ecological risk. Our results show that the spatio-temperal distribution of the eco-environmental quality has greatly varied across this study area during different time spans. Natural eco-environmental quality has moderately degraded in 70% of this study area (mainly agricultural region, at a prefectural level from 2000 to 2010, and has slightly improved over the agricultural region (<170 m above sea level during 2010–2015. However, when considering negative stressors from human social system on the natural ecosystem, the extent and distribution of the ecological risk varied across the whole area during 2000–2015. The results show that there was almost 90.40% of this region under the ecological risk, with varying extents over the study time, e.g., Kaifeng, Shangqiu, Xuchang, and Xinyang, with a moderate deterioration in the eco-environmental quality, and Zhengzhou with a slight deterioration in the eco-environmental quality. This paper provides a valuable perspective for governments at all levels to manage

  13. Characterization of the cytosolic distribution of priority pollutant metals and metalloids in the digestive gland cytosol of marine mussels: seasonal and spatial variability.

    Science.gov (United States)

    Strižak, Zeljka; Ivanković, Dušica; Pröfrock, Daniel; Helmholz, Heike; Cindrić, Ana-Marija; Erk, Marijana; Prange, Andreas

    2014-02-01

    Cytosolic profiles of several priority pollutant metals (Cu, Cd, Zn, Pb) and metalloid As were analyzed in the digestive gland of the mussel (Mytilus galloprovincialis) sampled at locations with different environmental pollution levels along the Croatian coast in the spring and summer season. Size-exclusion chromatography (SEC) connected to inductively coupled plasma mass spectrometry (ICP-MS) was used to determine selected elements bound to cytosolic biomolecules separated based on their molecular size. Copper, cadmium and zinc eluted mostly associated with high molecular weight (HMW) and medium molecular weight (MMW) biomolecules, but with a more prominent elution in the MMW peak at polluted locations which were probably associated with the 20 kDa metallothionein (MT). Elution of all three metals within this peak was also strongly correlated with cytosolic Cd as strong inducer of MT. Lead mostly eluted in HMW biomolecule range, but in elevated cytosolic Pb concentrations, significant amount eluted in low molecular weight (LMW) biomolecules. Arsenic, on the other hand eluted almost completely in LMW range, but we could not distinguish specific molecular weight biomolecules which would be predominant in detoxification mechanism. Seasonal variability in element abundance within specific peaks was present, although not in the same extent, for all elements and locations, especially for As. The results confirm the suitability of the distribution of selected metals/metalloids among different cytosolic ligands as potential indicator for metal exposure. Obtained findings can also serve as guidelines for further separation and characterization of specific cytosolic metal-binding biomolecules. © 2013.

  14. Distributions, sources and pollution status of 17 trace metal/metalloids in the street dust of a heavily industrialized city of central China.

    Science.gov (United States)

    Li, Zhonggen; Feng, Xinbin; Li, Guanghui; Bi, Xiangyang; Zhu, Jianming; Qin, Haibo; Dai, Zhihui; Liu, Jinling; Li, Qiuhua; Sun, Guangyi

    2013-11-01

    A series of representative street dust samples were collected from a heavily industrialized city, Zhuzhou, in central China, with the aim to investigate the spatial distribution and pollution status of 17 trace metal/metalloid elements. Concentrations of twelve elements (Pb, Zn, Cu, Cd, Hg, As, Sb, In, Bi, Tl, Ag and Ga) were distinctly amplified by atmospheric deposition resulting from a large scale Pb/Zn smelter located in the northwest fringe of the city, and followed a declining trend towards the city center. Three metals (W, Mo and Co) were enriched in samples very close to a hard alloy manufacturing plant, while Ni and Cr appeared to derive predominantly from natural sources. Other industries and traffic had neglectable effects on the accumulation of observed elements. Cd, In, Zn, Ag and Pb were the five metal/metalloids with highest pollution levels and the northwestern part of city is especially affected by heavy metal pollution. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Using a topographic index to distribute variable source area runoff predicted with the SCS curve-number equation

    Science.gov (United States)

    Lyon, Steve W.; Walter, M. Todd; Gérard-Marchant, Pierre; Steenhuis, Tammo S.

    2004-10-01

    Because the traditional Soil Conservation Service curve-number (SCS-CN) approach continues to be used ubiquitously in water quality models, new application methods are needed that are consistent with variable source area (VSA) hydrological processes in the landscape. We developed and tested a distributed approach for applying the traditional SCS-CN equation to watersheds where VSA hydrology is a dominant process. Predicting the location of source areas is important for watershed planning because restricting potentially polluting activities from runoff source areas is fundamental to controlling non-point-source pollution. The method presented here used the traditional SCS-CN approach to predict runoff volume and spatial extent of saturated areas and a topographic index, like that used in TOPMODEL, to distribute runoff source areas through watersheds. The resulting distributed CN-VSA method was applied to two subwatersheds of the Delaware basin in the Catskill Mountains region of New York State and one watershed in south-eastern Australia to produce runoff-probability maps. Observed saturated area locations in the watersheds agreed with the distributed CN-VSA method. Results showed good agreement with those obtained from the previously validated soil moisture routing (SMR) model. When compared with the traditional SCS-CN method, the distributed CN-VSA method predicted a similar total volume of runoff, but vastly different locations of runoff generation. Thus, the distributed CN-VSA approach provides a physically based method that is simple enough to be incorporated into water quality models, and other tools that currently use the traditional SCS-CN method, while still adhering to the principles of VSA hydrology.

  16. Air pollution and forest ecosystems: a regional to global perspective

    International Nuclear Information System (INIS)

    Taylor, G.E.; Johnson, D.W.; Andersen, C.P.

    1994-01-01

    Changes in the atmospheric concentrations of a number of air pollutants over the last century are hallmarks of the magnitude and extent of human impact on the environment. Some of these changes are important to ecologists because many pollutants, acting singly or in combination, affect ecological systems in general and forests in particular. The greatest concern lies with chronic levels of tropospheric ozone, cumulative deposition of hydrogen ion, nitrogen, and sulfur via wet and dry processes, a select number of airborne chemicals (e.g., mercury) that tend to bio accumulate in continental landscapes, and ultraviolet—B radiation through the loss of stratospheric ozone. Because the atmospheric residence time of most pollutants of concern to ecologists is measured on time frames extending from a few weeks to decades, pollutant distribution and effects are regional to global in dimension. We present evidence that ambient levels of some air pollutants in North America are affecting managed and unmanaged forests, and that the two most important pollutants are tropospheric ozone and chronic nitrogen loading. Further evidence indicates that while concentrations of some air pollutants have been declining over the last decade in North America, others are expected to remain unchanged or increase, including tropospheric ozone. We conclude that air pollution is affecting many North American forests and some remote forests around the globe. In the immediate future, the concern for air pollution effects on forests and associated natural resources will broaden to include interactions with changes in climate and pollution effects in the world's developing countries. There has been a rapid evolution in air pollution studies in ecology, shifting away from the agricultural paradigm of single—factor experimentation toward new methodologies that are ecologically and multidisciplinarily based. This shift has been promoted by the recognition that air pollution is one of several

  17. Occurrence and distribution of selected heavy metals in the surface sediments of South Brittany coastal waters: An assessment using pollution indicators

    Science.gov (United States)

    Ong, M. C.; Menier, D.; Noor Azhar, M. S.; Dupont, V.; Révillon, S.

    2012-04-01

    In order to avoid the pollution of heavy metals in South Brittany water, it is necessary to establish the data and understand the mechanisms influencing the distribution of heavy metals of the area. One of the aims of this work was to assess heavy metals contamination in Gulf of Morbihan and Quiberon Bay. Another aim was to use interpolation surfaces per metals to assess the contamination separately per metal. A total of 196 bottom sediment samples were collected from the coastal waters in order to determine the spatial concentration of Cr, Mn, Co, Cu, Zn, Cd and Pb by Inductively Coupled Plasma Mass Spectrometry (ICPMS) after acid digestion. The average heavy metal concentrations are ranked as follows: Mn>Zn>Cr>Pb>Cu>Cu>Cd. In the gulf, metal enrichments observed compared to the bay environment may due river run-off from three major river (Auray, Le Marle and Novalo rivers) which carried municipal waste and maritime activities along the coastal area within the gulf. Beside those factors, the natural factors such as the sheltered basin morphology itself, fine sediment and low hydrodynamic regime which favour the in situ accumulation of pollutants. The level of pollution levels attributed to heavy metals was evaluated using several pollution indicators in order to determine anthropogenically derived sediment contamination. Comparison to sediment quality guidelines (SQGs), enrichment factors (EFs), index of geoaccumulation (Igeo) and contamination factors (CF) based on reference element and background value to compensate for the influence of the natural variability in sediment mineralogy and to assess whether the concentration observed in surface sediment represent background and contaminated levels and visualize using ArcGIS software. These analyses validated that the bottom sediment only enriched in Pb and the other metals in most sample are not due to artificial contamination. Overall, geochemistry of the samples show the effect of both natural and anthropogenic

  18. New trends in watershed management and protection

    International Nuclear Information System (INIS)

    Davis, J.L.

    1997-01-01

    I would like to present some new environmental technologies by shoving restoration projects that are currently being implemented in the eastern United States that require this co-operation for successful implementation. The environmental technologies that will be discussed include the use of existing or constructed wetlands to treat surface and groundwater impacted in contaminants from various sources. The main goal of these type projects are to provide a low-cost and effective treatment for existing pollution problems. Many of these projects are initiated by civic associations (or NGOs) that wanted to improve the state of environment in their area. Because everyone has the responsibility to a clean environment in which they live, NGOs, state government, business, and local citizens, and local citizens worked closely together to solve problems in their watersheds. These projects are only examples of what is being done in the United States. However, I would like also to discuss what projects exist in eastern Slovakia, and others that could be started in Slovakia that improve relationships between MGOs and the state and local governmental decision-making process, with the ultimate goal to improve water quality in the Danube watershed in the future. There are severe environmental technologies that can be applied to improve the water quality of rivers throughout the Danube watershed, such as treatment of wastewater using wetland vegetation, and treatment of acid-mine drainage. In April 1996, NGO People and Water in co-operation with the village governments of the Upper Torysa River watershed started the project Villages for the 3 rd millennium in the Carpathian Euro-Region. One of the main goals of this project is to introduce new environmental technologies in the rural communities of the Upper Torysa River area. Since people trust their eyes than their ears. It is important to initiate practical, pilot projects to convince citizens and governments that these low

  19. Modelling of the estimated contributions of different sub-watersheds and sources to phosphorous export and loading from the Dongting Lake watershed, China.

    Science.gov (United States)

    Hou, Ying; Chen, Weiping; Liao, Yuehua; Luo, Yueping

    2017-11-03

    Considerable growth in the economy and population of the Dongting Lake watershed in Southern China has increased phosphorus loading to the lake and resulted in a growing risk of lake eutrophication. This study aimed to reveal the spatial pattern and sources of phosphorus export and loading from the watershed. We applied an export coefficient model and the Dillon-Rigler model to quantify contributions of different sub-watersheds and sources to the total phosphorus (TP) export and loading in 2010. Together, the upper and lower reaches of the Xiang River watershed and the Dongting Lake Area contributed 60.9% of the TP exported from the entire watershed. Livestock husbandry appeared to be the largest anthropogenic source of TP, contributing more than 50% of the TP exported from each secondary sub-watersheds. The actual TP loading to the lake in 2010 was 62.9% more than the permissible annual TP loading for compliance with the Class III water quality standard for lakes. Three primary sub-watersheds-the Dongting Lake Area, the Xiang River, and the Yuan River watersheds-contributed 91.2% of the total TP loading. As the largest contributor among all sources, livestock husbandry contributed nearly 50% of the TP loading from the Dongting Lake Area and more than 60% from each of the other primary sub-watersheds. This study provides a methodology to identify the key sources and locations of TP export and loading in large lake watersheds. The study can provide a reference for the decision-making for controlling P pollution in the Dongting Lake watershed.

  20. Small Reservoir Impact on Simulated Watershed-Scale Nutrient Yield

    Directory of Open Access Journals (Sweden)

    Shane J. Prochnow

    2007-01-01

    Full Text Available The soil and water assessment tool (SWAT is used to assess the influence of small upland reservoirs (PL566 on watershed nutrient yield. SWAT simulates the impact of collectively increasing and decreasing PL566 magnitudes (size parameters on the watershed. Totally removing PL566 reservoirs results in a 100% increase in total phosphorus and an 82% increase in total nitrogen, while a total maximum daily load (TMDL calling for a 50% reduction in total phosphorus can be achieved with a 500% increase in the magnitude of PL566s in the watershed. PL566 reservoirs capture agriculture pollution in surface flow, providing long-term storage of these constituents when they settle to the reservoir beds. A potential strategy to reduce future downstream nutrient loading is to enhance or construct new PL566 reservoirs in the upper basin to better capture agricultural runoff.

  1. Can liming change root anatomy, biomass allocation and trace element distribution among plant parts of Salix × smithiana in trace element-polluted soils?

    Science.gov (United States)

    Vondráčková, Stanislava; Tlustoš, Pavel; Száková, Jiřina

    2017-08-01

    Willows (Salix spp.) are considered to be effective for the phytoremediation of trace elements from contaminated soils, but their efficiency is limited in heavily polluted soils because of poor growth. Liming can be a desirable measure to decrease the plant availability of elements, resulting in improved plant development. Notably, large root area and maximum soil penetration are basic parameters that improve the efficiency of phytoremediation. The impact of soil chemical properties on willow root anatomy and the distribution of trace elements below-ground have rarely been studied. The effect of liming on root parameters, biomass allocation and trace element distribution in non-harvestable (coarse roots, fine roots, stumps) and harvestable plant parts (twigs and leaves) of Salix × smithiana was assessed at the end of a 4-year pot experiment with two trace element-polluted soils that differed in terms of soil pH. Stump biomass predominated in weakly acidic soil. In neutral soil, the majority of biomass was located in fine roots and stumps; the difference from other plant parts was minor. Trace elements were the most concentrated in fine roots. Translocation to above-ground biomass increased as follows: Pb roots roots). Lime application decreased the concentrations of mobile Cd and Zn and related levels in plants, improved biomass production and root parameters and increased the removal of all trace elements in weakly acidic soil. None or minimum differences in the monitored parameters were recorded for dolomite treatments in both soils. The dose and source of liming had crucial effects on root anatomy. Growing willows in limed trace element-polluted soils is a suitable measure for combination of two remediation strategies, i.e. phytoextraction of Cd and Zn and assisted phytostabilization of As and Pb.

  2. Assessment of heavy metal pollution in vegetables and relationships with soil heavy metal distribution in Zhejiang province, China.

    Science.gov (United States)

    Ye, Xuezhu; Xiao, Wendan; Zhang, Yongzhi; Zhao, Shouping; Wang, Gangjun; Zhang, Qi; Wang, Qiang

    2015-06-01

    There are increasing concerns on heavy metal contaminant in soils and vegetables. In this study, we investigated heavy metal pollution in vegetables and the corresponding soils in the main vegetable production regions of Zhejiang province, China. A total of 97 vegetable samples and 202 agricultural soil samples were analyzed for the concentrations of Cd, Pb, As, Hg, and Cr. The average levels of Cd, Pb, and Cr in vegetable samples [Chinese cabbage (Brassica campestris spp. Pekinensis), pakchoi (Brassica chinensis L.), celery (Apium graveolens), tomato (Lycopersicon esculentum), cucumber (Colletotrichum lagenarium), cowpea (Vigna unguiculata), pumpkin (Cucurbita pepo L.), and eggplant (Solanum melongena)] were 0.020, 0.048, and 0.043 mg kg(-1), respectively. The Pb and Cr concentrations in all vegetable samples were below the threshold levels of the Food Quality Standard (0.3 and 0.5 mg kg(-1), respectively), except that two eggplant samples exceeded the threshold levels for Cd concentrations (0.05 mg kg(-1)). As and Hg contents in vegetables were below the detection level (0.005 and 0.002 mg kg(-1), respectively). Soil pollution conditions were assessed in accordance with the Chinese Soil Quality Criterion (GB15618-1995, Grade II); 50 and 68 soil samples from the investigated area exceeded the maximum allowable contents for Cd and Hg, respectively. Simple correlation analysis revealed that there were significantly positive correlations between the metal concentrations in vegetables and the corresponding soils, especially for the leafy and stem vegetables such as pakchoi, cabbage, and celery. Bio-concentration factor values for Cd are higher than those for Pb and Cr, which indicates that Cd is more readily absorbed by vegetables than Pb and Cr. Therefore, more attention should be paid to the possible pollution of heavy metals in vegetables, especially Cd.

  3. Linking Resilience of Aquatic Species to Watershed Condition

    Science.gov (United States)

    Flitcroft, R. L.

    2017-12-01

    Watershed condition means different things to different people. From the perspective of aquatic ecology, watershed condition may be interpreted to mean the capacity of a watershed to support life history diversity of native species. Diversity in expression of life history is thought to confer resilience allowing portions of the broader population to survive stressful conditions. Different species have different life history strategies, many of which were developed through adaptation to regional or local environmental conditions and natural disturbance regimes. By reviewing adaptation strategies for species of interest at regional scales, characteristics of watersheds that confer resilience may be determined. Such assessments must be completed at multiple levels of spatial organization (i.e. sub-watershed, watershed, region) allowing assessments to be inferred across broad spatial extents. In a project on the Wenatchee River watershed, we guided models of wildfire effects on bull trout and spring Chinook from a meta-population perspective to determine risks to survival at local and population scales over multiple extents of spatial organization. In other work in the Oregon Coast Range, we found that historic landslides continue to exert habitat-forming pressure at local scales, leading to patchiness in distribution of habitats for different life stages of coho salmon. Further, climate change work in Oregon estuaries identified different vulnerabilities in terms of juvenile rearing habitat depending on the species of interest and the intensity of future changes in climate. All of these studies point to the importance of considering physical conditions in watersheds at multiple spatial extents from the perspective of native aquatic species in order to understand risks to long-term survival. The broader implications of watershed condition, from this perspective, is the determination of physical attributes that confer resilience to native biota. This may require

  4. The application of predictive modelling for determining bio-environmental factors affecting the distribution of blackflies (Diptera: Simuliidae) in the Gilgel Gibe watershed in Southwest Ethiopia.

    Science.gov (United States)

    Ambelu, Argaw; Mekonen, Seblework; Koch, Magaly; Addis, Taffere; Boets, Pieter; Everaert, Gert; Goethals, Peter

    2014-01-01

    Blackflies are important macroinvertebrate groups from a public health as well as ecological point of view. Determining the biological and environmental factors favouring or inhibiting the existence of blackflies could facilitate biomonitoring of rivers as well as control of disease vectors. The combined use of different predictive modelling techniques is known to improve identification of presence/absence and abundance of taxa in a given habitat. This approach enables better identification of the suitable habitat conditions or environmental constraints of a given taxon. Simuliidae larvae are important biological indicators as they are abundant in tropical aquatic ecosystems. Some of the blackfly groups are also important disease vectors in poor tropical countries. Our investigations aim to establish a combination of models able to identify the environmental factors and macroinvertebrate organisms that are favourable or inhibiting blackfly larvae existence in aquatic ecosystems. The models developed using macroinvertebrate predictors showed better performance than those based on environmental predictors. The identified environmental and macroinvertebrate parameters can be used to determine the distribution of blackflies, which in turn can help control river blindness in endemic tropical places. Through a combination of modelling techniques, a reliable method has been developed that explains environmental and biological relationships with the target organism, and, thus, can serve as a decision support tool for ecological management strategies.

  5. Cartographic modelling of aerotechnogenic pollution in snow cover in the landscapes of the Kola Peninsula.

    Science.gov (United States)

    Ratkin, N E; Asming, V E; Koshkin, V V

    2001-01-01

    The goal of this work was to develop computational techniques for sulphates, nickel and copper accumulation in the snow in the local pollution zone. The main task was to reveal the peculiarities of formation and pollution of snow cover on the region with complex cross-relief. A digital cartographic model of aerotechnogenic pollution of snow cover in the landscapes of the local zone has been developed, based on five-year experimental data. Data regarding annual emissions from the industrial complex, information about distribution of wind and the sum of precipitation from meteostation "Nikel" for the winter period, allowed the model to ensure: * material presentation in the form of maps of water capacity and accumulation of sulphates, nickel and copper in the snow over any winter period in retrospective; * calculation of water capacity and accumulation of pollutants for watersheds and other natural-territorial complexes; * solution of the opposite problem about the determination of the emissions of sulphates, nickel and copper from the enterprise by measuring snow pollution in datum points. The model can be used in other northern regions of the Russian Federation with similar physical-geographical and climatic conditions. The relationships between the sum of precipitation and water capacity in the landscapes of the same type and also the relationships between pollution content in snow and relief, pollution content in snow and distance from the source of emissions, were used as the basis for the model.

  6. The macromycetes of Boletus genus as environmental indicators of distribution and evolution of conventional and radioactive pollution [Emilia Romagna

    International Nuclear Information System (INIS)

    Nonnis Marzano, F.; Triulzi, C.; Bracchi, P.G.; Meloni, S.

    1997-01-01

    A radioactive and conventional pollution assessment was carried out by using macromycetes of the genus Boletus as bioindicators of environmental contamination. The results suggested the definition of concentration ranges for each ecosystem with the aim of certifying the real origin of the mushrooms. Particularly, radiometrical analyses coupled to neutron activation analysis for the determination of trace elements can be used for controlling the correct trading of the Valtaro Boletus. Such control will be more requested in the future in relation to the IGP (protected geographycal indication) brand assigned by the European Community to the Taro Valley [it

  7. Technogenic and natural radionuclides in the bottom sediments of the Sea of Azov: regularities of distribution and application to the study of pollutants accumulation chronology

    Science.gov (United States)

    Kuznetsov, A. N.; Fedorov, Yu A.; Yaroslavtsev, V. M.

    2018-01-01

    The study of pollutants vertical distribution in seabed sediments is of high interest as they conserve the information on the chronology of pollution level in the past. In the present paper, the results of layer by layer study of Cs-137, Am-241, Pb-210 specific activities as well as concentrations of petroleum components, lead and mercury in 48 sediment cores of the Sea of Azov, the Don River and the Kuban River are examined. In most sediment cores, two peaks of Cs-137 and Am-241 are detected. The upper of them was formed due to the Chernobyl accident in 1986 and the other is related to the global nuclear fallout of 1960s. The specific activity of naturally occurring atmospheric Lead-210 decreases exponentially with the sediment core depth. However, it is influenced by fluvial run-off, coastal erosion, Radium-226 and Radon-222 decay. The data on the radionuclides distribution in the seabed sediments is used to date them. According to the results of dating, most of petroleum components, lead and mercury quantities are concentrated in the upper sediment layer formed in the last 50 to 70 years i.e. in the period of the most important anthropogenic pressure.

  8. Distribution of guppies Poecilia reticulata (Peters, 1860 and Phalloceros caudimaculatus (Hensel, 1868 along a polluted stretch of the Paraíba do Sul River, Brazil

    Directory of Open Access Journals (Sweden)

    FG. Araújo

    Full Text Available Cyprinodontiformes fishes (guppies are widely distributed in Neotropical regions and use deteriorated microhabitats in rivers where few species can occur. This study was carried out in a stretch of the Paraíba do Sul River in bracketing a large urban-industrial complex. The aim was to assess eventual effects that the industrial complex could have on distribution of two closely related fish species of guppies, Phalloceros caudimaculatus and Poecilia reticulata. The area was divided into three zones: Z1, 40 km upriver of the major urban-industrial complex of Volta Redonda; Z2, just down river of the complex; and Z3, 30 km down river of the complex. Six sites (two in each zone were sampled monthly between November 1998 and October 1999, using a standardized fishing effort with cast net throws, trays lifts and seine hauls, covering different microhabitats, that is, riffles, pools and the proximity of the river's margins. Poecilia reticulata was widely distributed, peaking at Z2, the most polluted area, while P. caudimaculatus showed the highest abundance at Z3, being almost absent in Z1. Both species occurred in high numbers throughout the year but they were scarce between April and June. Females outnumbered males for both species in most size classes and at all sites. Juveniles were more abundant than adults, with non-pregnant females outnumbering pregnant ones. Condition factor was always higher in males than females but only males P. reticulata showed significant difference among the three zones, with the highest values at Z2. The higher number of females confirms the expectation that these species can use very polluted areas and that availability of food provided by organic loads allowed their distribution all over the area. Although these two species have shown indication of spatial separation in the study area, their similar seasonal patterns of occurrence suggest that they respond in a similar way to changes in environmental conditions.

  9. [Impact on nitrogen and phosphorous export of wetlands in Tianmu Lake watershed].

    Science.gov (United States)

    Li, Zhao-Fu; Liu, Hong-Yu; Li, Heng-Peng

    2012-11-01

    Focused on understanding the function of wetland in improving water quality, Pingqiao watershed and Zhongtian watershed in Tianmu Lake drinking water sources area were selected as the research region. We integrated remote sensing, GIS techniques with field investigation and chemical analysis to analyze the relationship between wetland and water quality in watershed scale. Results show: (1) There are many wetland patches in Pingqiao and Zhongtian watershed, wetlands patch densities were respectively 7.5 km(-2) and 7.1 km(-2). Wetlands widely distributed in the Pingqiao watershed with mostly located away from the river of 500 m, whereas wetlands relatively concentrated in the lower reach within 500 meters of riverside in Zhongtian watershed. (2) Nitrogen and phosphorus nutrient retention of wetland in watershed scale was significant. The annual mean TN and DTN concentration had a strong relationship with percent area of wetlands in Zhongtian watershed while the weakest relationship was found with TP and DTP concentrations, especially, the mean TN and DTN concentrations in spring and winter had the significantly negative relationship with wetland areas of watershed. The negative relationship was existed for nitrogen in autumn of Pingqiao watershed, which suggested that watersheds varying in area of wetlands have the different nutrient reducing efficiency in seasonal periods. (3) A certain number and area of wetland will improve river water quality in watershed scale, which can instruct water environment treatment. However, considering the complexity of nutrient transport processes in watershed, wetland-related factors such as area, location, density, ecosystem structure and watershed-related factors such as temporal interval, spatial scales, slope and land use will impact on the transport processes, and related theoretical and practical problems need further research.

  10. Laser altimeter measurements at Walnut Gulch Watershed, Arizona

    International Nuclear Information System (INIS)

    Ritchie, J.C.; Humes, K.S.; Weltz, M.A.

    1995-01-01

    Measurements of landscape surface roughness properties are necessary for understanding many watershed processes. This paper reviews the use of an airborne laser altimeter to measure topography and surface roughness properties of the landscape at Walnut Gulch Watershed in Arizona. Airborne laser data were used to measure macro and micro topography as well as canopy topography, height, cover, and distribution. Macro topography of landscape profiles for segments up to 5 km (3 mi) were measured and were in agreement with available topographic maps but provided more detail. Gullies and stream channel cross-sections and their associated floodplains were measured. Laser measurements of vegetation properties (height and cover) were highly correlated with ground measurements. Landscape segments for any length can be used to measure these landscape roughness properties. Airborne laser altimeter measurements of landscape profiles can provide detailed information on watershed surface properties for improving the management of watersheds. (author)

  11. Evaluating Hydrologic Response of an Agricultural Watershed for Watershed Analysis

    OpenAIRE

    Manoj Kumar Jha

    2011-01-01

    This paper describes the hydrological assessment of an agricultural watershed in the Midwestern United States through the use of a watershed scale hydrologic model. The Soil and Water Assessment Tool (SWAT) model was applied to the Maquoketa River watershed, located in northeast Iowa, draining an agriculture intensive area of about 5,000 km2. The inputs to the model were obtained from the Environmental Protection Agency’s geographic information/database system called Better Assessment Science...

  12. Integrated Modeling System for Analysis of Watershed Water Balance: A Case Study in the Tims Branch Watershed, South Carolina

    Science.gov (United States)

    Setegn, S. G.; Mahmoudi, M.; Lawrence, A.; Duque, N.

    2015-12-01

    The Applied Research Center at Florida International University (ARC-FIU) is supporting the soil and groundwater remediation efforts of the U.S. Department of Energy (DOE) Savannah River Site (SRS) by developing a surface water model to simulate the hydrology and the fate and transport of contaminants and sediment in the Tims Branch watershed. Hydrological models are useful tool in water and land resource development and decision-making for watershed management. Moreover, simulation of hydrological processes improves understanding of the environmental dynamics and helps to manage and protect water resources and the environment. MIKE SHE, an advanced integrated modeling system is used to simulate the hydrological processes of the Tim Branch watershed with the objective of developing an integrated modeling system to improve understanding of the physical, chemical and biological processes within the Tims Branch watershed. MIKE SHE simulates water flow in the entire land based phase of the hydrological cycle from rainfall to river flow, via various flow processes such as, overland flow, infiltration, evapotranspiration, and groundwater flow. In this study a MIKE SHE model is developed and applied to the Tim branch watershed to study the watershed response to storm events and understand the water balance of the watershed under different climatic and catchment characteristics. The preliminary result of the integrated model indicated that variation in the depth of overland flow highly depend on the amount and distribution of rainfall in the watershed. The ultimate goal of this project is to couple the MIKE SHE and MIKE 11 models to integrate the hydrological component in the land phase of hydrological cycle and stream flow process. The coupled MIKE SHE/MIKE 11 model will further be integrated with an Ecolab module to represent a range of water quality, contaminant transport, and ecological processes with respect to the stream, surface water and groundwater in the Tims

  13. Effects of pollution on freshwater fish

    International Nuclear Information System (INIS)

    McKim, J.M.; Anderson, R.L.; Benoit, D.A.; Spehar, R.L.; Stokes, G.N.

    1976-01-01

    Studies of the effects of pollution on freshwater fish are reviewed. Subjects include: inorganic industrial pollutants, man-made disturbances and radioactive pollutants. Topics include uptake distribution, retention, mortality, and lethal doses

  14. Hydrological Modeling of the Jiaoyi Watershed (China) Using HSPF Model

    Science.gov (United States)

    Yan, Chang-An; Zhang, Wanchang; Zhang, Zhijie

    2014-01-01

    A watershed hydrological model, hydrological simulation program-Fortran (HSPF), was applied to simulate the spatial and temporal variation of hydrological processes in the Jiaoyi watershed of Huaihe River Basin, the heaviest shortage of water resources and polluted area in China. The model was calibrated using the years 2001–2004 and validated with data from 2005 to 2006. Calibration and validation results showed that the model generally simulated mean monthly and daily runoff precisely due to the close matching hydrographs between simulated and observed runoff, as well as the excellent evaluation indicators such as Nash-Sutcliffe efficiency (NSE), coefficient of correlation (R 2), and the relative error (RE). The similar simulation results between calibration and validation period showed that all the calibrated parameters had a certain representation in Jiaoyi watershed. Additionally, the simulation in rainy months was more accurate than the drought months. Another result in this paper was that HSPF was also capable of estimating the water balance components reasonably and realistically in space through the whole watershed. The calibrated model can be used to explore the effects of climate change scenarios and various watershed management practices on the water resources and water environment in the basin. PMID:25013863

  15. Adaptive Management Fitness of Watersheds

    Directory of Open Access Journals (Sweden)

    Ignacio Porzecanski

    2012-09-01

    Full Text Available Adaptive management (AM promises to improve our ability to cope with the inherent uncertainties of managing complex dynamic systems such as watersheds. However, despite the increasing adherence and attempts at implementation, the AM approach is rarely successful in practice. A one-size-fits-all AM strategy fails because some watersheds are better positioned at the outset to succeed at AM than others. We introduce a diagnostic tool called the Index of Management Condition (IMC and apply it to twelve diverse watersheds in order to determine their AM "fitness"; that is, the degree to which favorable adaptive management conditions are in place in a watershed.

  16. Rare earth elements determination and distribution patterns in sediments of a polluted marine environment by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Yusof, A.M.

    2001-01-01

    Results obtained from the analysis of sediment core samples taken from a fairly polluted marine environment were analyzed for the REE contents to determine the concentrations of La, Ce, Sm, Eu, Tb, Dy and Yb using instrumental neutron activation analysis. Core samples were divided into strata of between 2 to 3 cm intervals and prepared in the powdered form before irradiating them in a neutron flux of about 5.0 x 10 12 n x cm -2 x s -1 in a Triga Mark II reactor. Down-core concentration profiles of La, Ce, Sm, Eu, Tb, Dy and Yb in 3 core sediments from three sites are obtained. The shale-normalized REE pattern from each site was examined and later used to explain the history of sedimentation by natural processes such as shoreline erosion and weathering products deposited on the seabed and furnishing some baseline data and/or pollution trend occurring within the study area. The shale-normalized REE patterns also showed that LREE in the sediment samples exhibit enrichment relative to HREE particularly, La and Sm showing enrichment compared to the ratios in shale. REE concentrations of 124 μg/g at the surface of sediment collected at two of the three sites were found to decrease to 58 and 95 μg/g, respectively. This was of particular interest when it is used to explain the anomalies occurring in the marine sediment as a result of geochemical processes over a long period of time. Changes in concentrations from surface to bottom of the sediments ratioed to Sm concentrations and the correlation between concentrations of Sm and these elements were also investigated and correlation coefficients were calculated for all REEs and sites. Validation of the method used was done using a Soil-7 SRM. (author)

  17. Joint analysis of input and parametric uncertainties in watershed water quality modeling: A formal Bayesian approach

    Science.gov (United States)

    Han, Feng; Zheng, Yi

    2018-06-01

    Significant Input uncertainty is a major source of error in watershed water quality (WWQ) modeling. It remains challenging to address the input uncertainty in a rigorous Bayesian framework. This study develops the Bayesian Analysis of Input and Parametric Uncertainties (BAIPU), an approach for the joint analysis of input and parametric uncertainties through a tight coupling of Markov Chain Monte Carlo (MCMC) analysis and Bayesian Model Averaging (BMA). The formal likelihood function for this approach is derived considering a lag-1 autocorrelated, heteroscedastic, and Skew Exponential Power (SEP) distributed error model. A series of numerical experiments were performed based on a synthetic nitrate pollution case and on a real study case in the Newport Bay Watershed, California. The Soil and Water Assessment Tool (SWAT) and Differential Evolution Adaptive Metropolis (DREAM(ZS)) were used as the representative WWQ model and MCMC algorithm, respectively. The major findings include the following: (1) the BAIPU can be implemented and used to appropriately identify the uncertain parameters and characterize the predictive uncertainty; (2) the compensation effect between the input and parametric uncertainties can seriously mislead the modeling based management decisions, if the input uncertainty is not explicitly accounted for; (3) the BAIPU accounts for the interaction between the input and parametric uncertainties and therefore provides more accurate calibration and uncertainty results than a sequential analysis of the uncertainties; and (4) the BAIPU quantifies the credibility of different input assumptions on a statistical basis and can be implemented as an effective inverse modeling approach to the joint inference of parameters and inputs.

  18. Assessment of metal contamination in a small mining- and smelting-affected watershed: high resolution monitoring coupled with spatial analysis by GIS.

    Science.gov (United States)

    Coynel, Alexandra; Blanc, Gérard; Marache, Antoine; Schäfer, Jörg; Dabrin, Aymeric; Maneux, Eric; Bossy, Cécile; Masson, Matthieu; Lavaux, Gilbert

    2009-05-01

    The Riou Mort River watershed (SW France), representative of a heavily polluted, small, heterogeneous watershed, represents a major source for the polymetallic pollution of the Lot-Garonne-Gironde fluvial-estuarine system due to former mining and ore-treatment activities. In order to assess spatial distribution of the metal/metalloid contamination in the watershed, a high resolution hydrological and geochemical monitoring were performed during one year at four permanent observation stations. Additionally, thirty-five stream sediment samples were collected at representative key sites and analyzed for metal/metalloid (Cd, Zn, Cu, Pb, As, Sb, Mo, V, Cr, Co, Ni, Th, U and Hg) concentrations. The particulate concentrations in water and stream sediments show high spatial differences for most of the studied elements suggesting strong anthropogenic and/or lithogenic influences; for stream sediments, the sequence of the highest variability, ranging from 100% to 300%, is the following: Mo < Cu < Hg < As < Sb < Cd < Zn < Pb. Multidimensional statistical analyses combined with metal/metalloid maps generated by GIS tool were used to establish relationships between elements, to identify metal/metalloid sources and localize geochemical anomalies attributed to local geochemical background, urban and industrial activities. Finally, this study presents an approach to assess anthropogenic trace metal inputs within this watershed by combining lithology-dependent geochemical background values, metal/metalloid concentrations in stream sediments and mass balances of element fluxes at four key sites. The strongest anthropogenic contributions to particulate element fluxes are 90-95% for Cd, Zn and Hg in downstream sub-catchments. The localisation of anthropogenic metal/metalloid sources in restricted areas offers a great opportunity to further significantly reduce metal emissions and restore the Lot-Garonne-Gironde fluvial-estuarine ecosystem.

  19. Gas fired boilers and atmospheric pollution

    International Nuclear Information System (INIS)

    Chiaranello, J.M.

    1991-01-01

    A general analysis concerning atmospheric pollution is presented: chemical composition and vertical distribution of atmosphere and pollutants, chemical reactions, ozone destruction and production cycles, COx, NOx and SOx pollutions. The gas fired boiler number and repartition in France are presented and the associated pollution is analyzed (CO2, CO, NOx) and quantified. Various pollution control technics concerning gas fired boiler pollutants are described and a pollution criterion for clean gas fired generators is proposed

  20. Technical Note: Determination of the SCS initial abstraction ratio in an experimental watershed in Greece

    Science.gov (United States)

    Baltas, E. A.; Dervos, N. A.; Mimikou, M. A.

    2007-11-01

    The present study was conducted in an experimental watershed in Attica, Greece, using observed rainfall/runoff events. The objective of the study was the determination of the initial abstraction ratio of the watershed. The average ratio (Ia/S) of the entire watershed was equal to 0.014. The corresponding ratio at a subwatershed was 0.037. The difference was attributed to the different spatial distribution of landuses and geological formations at the extent of the watershed. Both of the determined ratios are close to the ratio value of 0.05 that has been suggested from many studies for the improvement of the SCS-CN method.

  1. MOBIDIC-U: a watershed-scale model for stormwater attenuation through green infrastructures design

    Science.gov (United States)

    Ercolani, G.; Masseroni, D.; Chiaradia, E. A.; Bischetti, G. B.; Gandolfi, C.; Castelli, F.

    2017-12-01

    Surface water degradation resulting from the effects of urbanization on hydrology, water quality, habitat as well as ecological and environmental compartments represents an issue of primary focus for multiple agencies at the national, regional and local levels. Many management actions are needed throughout urban watersheds to achieve the desired effects on flow mitigation and pollutant reduction, but no single standardized solution can be effective in all locations. In this work, the distributed hydrological model MOBIDIC, already applied for hydrological balance simulations and flood prevention in different Italian regions, is adapted to the urban context (MOBIDIC-U) in order to evaluate alternative plans for stormwater quality management and flow abatement techniques through the adoption of green infrastructures (GIs). In particular the new modules included in MOBIDIC-U allow to (i) automatically define the upstream flow path as well as watershed boundary starting from a selected watershed closure point on the urban drainage network and (ii) obtain suitable graphical outputs for the visualization of flow peak and volume attenuation at the closure point. Moreover, MOBIDIC-U provides a public domain tool capable of evaluating the optimal location, type, and cost of the stormwater management practices needed to meet water quantity and quality goals. Despite the scalability of the model to different urban contexts, the current version of MOBIDIC-U has been developed for the area of the metropolitan city of Milan, Northern Italy. The model is implemented on a GIS platform, which already contains (i) the structure of the urban drainage network of the metropolitan city of Milan; (ii) the database of actual geomorphological and meteorological data for the previous domain (iii) the list of potential GIs, their standard size, installation and maintenance costs. Therefore, MOBIDIC-U provides an easy to use tool to local professionals to design and evaluate urban stormwater

  2. Wintertime pollution level, size distribution and personal daily exposure to particulate matters in the northern and southern rural Chinese homes and variation in different household fuels.

    Science.gov (United States)

    Du, Wei; Shen, Guofeng; Chen, Yuanchen; Zhuo, Shaojie; Xu, Yang; Li, Xinyue; Pan, Xuelian; Cheng, Hefa; Wang, Xilong; Tao, Shu

    2017-12-01

    This study investigated and compared wintertime air pollution and personal exposure in the rural northern and southern Chinese homes. Daily indoor and outdoor particle samples were simultaneously collected by using stationary samplers, and personal exposure was directly measured using portable carried samplers. The daily average concentrations of indoor and outdoor PM 2.5 were 521 ± 234 and 365 ± 185 μg/m 3 in the northern village, that were about 2.3-2.7 times of 188 ± 104 and 150 ± 29 μg/m 3 in indoor and outdoor air in the southern villages. Particle size distribution was similar between indoor and outdoor air, and had relatively smaller difference between the two sites, relative to the particle mass concentration difference. PM 2.5 contributed to ∼80% of the TSP mass, and in PM 2.5 , near 90% were PM 1.0 . In homes using electricity in the southern villages, outdoor air pollution could explain 70-80% of the variation in indoor air pollution. The daily exposure to PM 2.5 measured using personal carried samplers were 451 ± 301 μg/m 3 in the northern villages with traditional solid fuels used for daily cooking and heating, and in the southern villages without heating, the exposure to PM 2.5 were 184 ± 83 and 166 ± 45 μg/m 3 , respectively, for the population using wood and electricity for daily cooking. Time-weighted daily average exposure estimated from area concentration and time spent indoor and outdoor was generally correlated the directly measured exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Calibration and validation of the SWAT model for a forested watershed in coastal South Carolina

    Science.gov (United States)

    Devendra M. Amatya; Elizabeth B. Haley; Norman S. Levine; Timothy J. Callahan; Artur Radecki-Pawlik; Manoj K. Jha

    2008-01-01

    Modeling the hydrology of low-gradient coastal watersheds on shallow, poorly drained soils is a challenging task due to the complexities in watershed delineation, runoff generation processes and pathways, flooding, and submergence caused by tropical storms. The objective of the study is to calibrate and validate a GIS-based spatially-distributed hydrologic model, SWAT...