WorldWideScience

Sample records for runoff alternatives study

  1. Evaluation of alternative surface runoff accounting procedures using the SWAT model

    Science.gov (United States)

    For surface runoff estimation in the Soil and Water Assessment Tool (SWAT) model, the curve number (CN) procedure is commonly adopted to calculate surface runoff by utilizing antecedent soil moisture condition (SCSI) in field. In the recent version of SWAT (SWAT2005), an alternative approach is ava...

  2. Study on Water Quality of Surface Runoff and Groundwater Runoff on the Basis of Separation by a Numerical Filter

    OpenAIRE

    Kawara, Osami; Fukumoto, Kohji

    1994-01-01

    In this study we investigated the water quality of surface runoff and groundwater runoff from the basins of the Yodo River and the Asahi River based on that separated by a numerical filter. The water quality of the surface runoff is greatly different from the groundwater runoff. The tendency of concentration change in accordance with river discharges is different from each other. The water qtiality of groundwater runoff changes with river discharges clockwise in many cases. The differences of...

  3. Runoff erosion

    OpenAIRE

    Evelpidou, Niki (Ed.); Cordier, Stephane (Ed.); Merino, Agustin (Ed.); Figueiredo, Tomás de (Ed.); Centeri, Csaba (Ed.)

    2013-01-01

    Table of Contents PART I – THEORY OF RUNOFF EROSION CHAPTER 1 - RUNOFF EROSION – THE MECHANISMS CHAPTER 2 - LARGE SCALE APPROACHES OF RUNOFF EROSION CHAPTER 3 - MEASURING PRESENT RUNOFF EROSION CHAPTER 4 - MODELLING RUNOFF EROSION CHAPTER 5 - RUNOFF EROSION AND HUMAN SOCIETIES: THE INFLUENCE OF LAND USE AND MANAGEMENT PRACTICES ON SOIL EROSION PART II - CASE STUDIES CASE STUDIES – INTRODUCTION: RUNOFF EROSION IN MEDITERRANEAN AREA CASE STUDY 1: Soil Erosion Risk...

  4. New Bedford Harbor Superfund Project, Acushnet River Estuary Engineering Feasibility Study of Dredging and Dredged Material Disposal Alternatives. Report 4. Surface Runoff Quality Evaluation for Confined Disposal

    Science.gov (United States)

    1988-01-01

    infiltration studies ( Westerdahl and Skogerboe 1982). Exten- sive field verification studies have been conducted with the WES Rainfall Simulator...Lysimeter System on a wide range of USACE project sites ( Westerdahl and Skogerboe 1982, Lee and Skogerboe 1984, Skogerboe et al. 1987). The WES Rainfall...Criteria for Water 1986,"’ Criteria and Standards Division, Washington, DC. Westerdahl , H. E., and Skogerboe, J. G. 1982. "Realistic Rainfall and Water

  5. Study of heavy metals in urban runoff

    International Nuclear Information System (INIS)

    Nabizadeh, R.; Mahvi, A.; Mardani, G.; Yunesian, M.

    2005-01-01

    A cross-sectional survey was conducted through Tehran city and a field study was conducted to prepare main and accessory drainage channels map. Three main drainage channels were identified for this research and some sampling stations were chosen. Three stations selected in south of Tehran. The reason for selecting these stations is that all urban surface run off completely pass through these points and samples taken from these points are representative of all kinds of pollutants that transit from city surface. Another three stations were selected in center and further three stations were selected at north of Tehran. Surface runoff flow in three main channels, from north of south of Tehran, converge at south of Rey city and finally end up to Ghom Salt lake. The stations were chosen at three trajectories Sorkhe Hesar, Emad Avard, Kan. At each month two samples were from nine different stations. After collection of samples with respect to standard methods, they were dissolved in nitric acid and then analyzed by atomic absorption device. The results show that the concentrations of pollutants increased from north to south. For instance, Zinc had most concentration with monthly average of 0.98 mg/l and Nickel had the lowest amount with 0.02 mg/l in southern stations. Average concentration of Zn, Pb, Cd, Cu and Ni were: 0.638, 0.97, 0.04 and 0.035 mg/l respectively. Total average concentrations of heavy metals at three main channels were of 0.177, 0.176 and 0.145 mg/l. Emad Avard was the most polluted channel

  6. A protocol for conducting rainfall simulation to study soil runoff.

    Science.gov (United States)

    Kibet, Leonard C; Saporito, Louis S; Allen, Arthur L; May, Eric B; Kleinman, Peter J A; Hashem, Fawzy M; Bryant, Ray B

    2014-04-03

    Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The objective of this study was to characterize the effects of antecedent soil moisture content on the fate and transport of surface applied commercial urea, a common form of nitrogen (N) fertilizer, following a rainfall event that occurs within 24 hr after fertilizer application. Although urea is assumed to be readily hydrolyzed to ammonium and therefore not often available for transport, recent studies suggest that urea can be transported from agricultural soils to coastal waters where it is implicated in harmful algal blooms. A rainfall simulator was used to apply a consistent rate of uniform rainfall across packed soil boxes that had been prewetted to different soil moisture contents. By controlling rainfall and soil physical characteristics, the effects of antecedent soil moisture on urea loss were isolated. Wetter soils exhibited shorter time from rainfall initiation to runoff initiation, greater total volume of runoff, higher urea concentrations in runoff, and greater mass loadings of urea in runoff. These results also demonstrate the importance of controlling for antecedent soil moisture content in studies designed to isolate other variables, such as soil physical or chemical characteristics, slope, soil cover, management, or rainfall characteristics. Because rainfall simulators are designed to deliver raindrops of similar size and velocity as natural rainfall, studies conducted under a standardized protocol can yield valuable data that, in turn, can be used to develop models for predicting the fate and transport of pollutants in runoff.

  7. A field study to evaluate runoff quality from green roofs.

    Science.gov (United States)

    Vijayaraghavan, K; Joshi, U M; Balasubramanian, R

    2012-03-15

    Green (vegetated) roofs are emerging as practical strategies to improve the environmental quality of cities. However, the impact of green roofs on the storm water quality remains a topic of concern to city planners and environmental policy makers. This study investigated whether green roofs act as a source or a sink of various metals (Na, K, Ca, Mg, Al, Fe, Cu, Cd, Pb, Zn, Mn, Cr, Ni, Li and Co), inorganic anions (NO3-, NO2-, PO4(3-), SO4(2-), Cl-, F- and Br-) and cation (NH4+). A series of green roof assemblies were constructed. Four different real rain events and several artificial rain events were considered for the study. Results showed that concentrations of most of the chemical components in runoff were highest during the beginning of rain events and subsided in the subsequent rain events. Some of the important components present in the runoff include Na, K, Ca, Mg, Li, Fe, Al, Cu, NO3-, PO4(3-) and SO4(2-). However, the concentration of these chemical components in the roof runoff strongly depends on the nature of substrates used in the green roof and the volume of rain. Based on the USEPA standards for freshwater quality, we conclude that the green roof used in this study is reasonably effective except that the runoff contains significant amounts of NO3- and PO4(3-). Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Soil erosion-runoff relationships: insights from laboratory studies

    Science.gov (United States)

    Mamedov, Amrakh; Warrington, David; Levy, Guy

    2016-04-01

    Understanding the processes and mechanisms affecting runoff generation and subsequent soil erosion in semi-arid regions is essential for the development of improved soil and water conservation management practices. Using a drip type laboratory rain simulator, we studied runoff and soil erosion, and the relationships between them, in 60 semi-arid region soils varying in their intrinsic properties (e.g., texture, organic matter) under differing extrinsic conditions (e.g., rain properties, and conditions prevailing in the field soil). Both runoff and soil erosion were significantly affected by the intrinsic soil and rain properties, and soil conditions within agricultural fields or watersheds. The relationship between soil erosion and runoff was stronger when the rain kinetic energy was higher rather than lower, and could be expressed either as a linear or exponential function. Linear functions applied to certain limited cases associated with conditions that enhanced soil structure stability, (e.g., slow wetting, amending with soil stabilizers, minimum tillage in clay soils, and short duration exposure to rain). Exponential functions applied to most of the cases under conditions that tended to harm soil stability (e.g., fast wetting of soils, a wide range of antecedent soil water contents and rain kinetic energies, conventional tillage, following biosolid applications, irrigation with water of poor quality, consecutive rain simulations). The established relationships between runoff and soil erosion contributed to a better understanding of the mechanisms governing overland flow and soil loss, and could assist in (i) further development of soil erosion models and research techniques, and (ii) the design of more suitable management practices for soil and water conservation.

  9. Seal design alternatives study

    International Nuclear Information System (INIS)

    Van Sambeek, L.L.; Luo, D.D.; Lin, M.S.; Ostrowski, W.; Oyenuga, D.

    1993-06-01

    This report presents the results from a study of various sealing alternatives for the WIPP sealing system. Overall, the sealing system has the purpose of reducing to the extent possible the potential for fluids (either gas or liquid) from entering or leaving the repository. The sealing system is divided into three subsystems: drift and panel seals within the repository horizon, shaft seals in each of the four shafts, and borehole seals. Alternatives to the baseline configuration for the WIPP seal system design included evaluating different geometries and schedules for seal component installations and the use of different materials for seal components. Order-of-magnitude costs for the various alternatives were prepared as part of the study. Firm recommendations are not presented, but the advantages and disadvantages of the alternatives are discussed. Technical information deficiencies are identified and studies are outlined which can provide required information

  10. Energy conversion alternatives study

    Science.gov (United States)

    Shure, L. T.

    1979-01-01

    Comparison of coal based energy systems is given. Study identifies and compares various advanced energy conversion systems using coal or coal derived fuels for baselaoad electric power generation. Energy Conversion Alternatives Study (ECAS) reports provede government, industry, and general public with technically consistent basis for comparison of system's options of interest for fossilfired electric-utility application.

  11. Assessing Variability and Errors in Historical Runoff Forecasting with Physical Models and Alternative Data Sources

    Science.gov (United States)

    Penn, C. A.; Clow, D. W.; Sexstone, G. A.

    2017-12-01

    Water supply forecasts are an important tool for water resource managers in areas where surface water is relied on for irrigating agricultural lands and for municipal water supplies. Forecast errors, which correspond to inaccurate predictions of total surface water volume, can lead to mis-allocated water and productivity loss, thus costing stakeholders millions of dollars. The objective of this investigation is to provide water resource managers with an improved understanding of factors contributing to forecast error, and to help increase the accuracy of future forecasts. In many watersheds of the western United States, snowmelt contributes 50-75% of annual surface water flow and controls both the timing and volume of peak flow. Water supply forecasts from the Natural Resources Conservation Service (NRCS), National Weather Service, and similar cooperators use precipitation and snowpack measurements to provide water resource managers with an estimate of seasonal runoff volume. The accuracy of these forecasts can be limited by available snowpack and meteorological data. In the headwaters of the Rio Grande, NRCS produces January through June monthly Water Supply Outlook Reports. This study evaluates the accuracy of these forecasts since 1990, and examines what factors may contribute to forecast error. The Rio Grande headwaters has experienced recent changes in land cover from bark beetle infestation and a large wildfire, which can affect hydrological processes within the watershed. To investigate trends and possible contributing factors in forecast error, a semi-distributed hydrological model was calibrated and run to simulate daily streamflow for the period 1990-2015. Annual and seasonal watershed and sub-watershed water balance properties were compared with seasonal water supply forecasts. Gridded meteorological datasets were used to assess changes in the timing and volume of spring precipitation events that may contribute to forecast error. Additionally, a

  12. Pollutant concentrations in road runoff: Southeast Queensland case study

    Energy Technology Data Exchange (ETDEWEB)

    Drapper, D.; Tomlinson, R.; Williams, P.

    2000-04-01

    This paper discusses the results of research into the pollutants in runoff from road pavement surfaces following natural rainfall events. Road runoff water quality was monitored at 21 sites centering around Brisbane, in southeast Queensland, Australia. The sites were selected according to traffic volumes, surrounding land use, pavement surface type, ease of access, and commercial vehicle percentage. Bridge sites were chosen for convenience of sample collection and minimized infrastructure modification. First flush grab samplers were permanently installed at each site to collect the first 20 L of runoff from one of the bridge drainage scuppers. The runoff samples were tested for a number of heavy metals, hydrocarbons, pesticides, and other physical characteristics. The observed results fall within the ranges of concentrations reported internationally and nationally but do not typically follow the 30,000 average annual daily traffic results reported in the United States. Traffic volumes have not been found to be the best indicator of road runoff pollutant concentrations. Interevent duration has been found to be a statistically significant factor for pollutant concentrations. Sites incorporating exit lanes have recorded higher concentrations of acid-extractable copper and zinc, tending to support the hypothesis that brake pad and tire wear caused by rapid deceleration contributes to the concentrations of these metals in road runoff. Laser particle sizing has shown that a significant proportion of the sediment found in the runoff is <100 {micro}m. However, these particulates do settle in water within 24 h, under laboratory conditions. This may be due to the presence of heavy metals.

  13. Tank Farm Interim Surface Barrier Materials And Runoff Alternatives Study

    International Nuclear Information System (INIS)

    Holm, M.J.

    2009-01-01

    This report identifies candidate materials and concepts for interim surface barriers in the single-shell tank farms. An analysis of these materials for application to the TY tank farm is also provided.

  14. Experimental study on soluble chemical transfer to surface runoff from soil.

    Science.gov (United States)

    Tong, Juxiu; Yang, Jinzhong; Hu, Bill X; Sun, Huaiwei

    2016-10-01

    Prevention of chemical transfer from soil to surface runoff, under condition of irrigation and subsurface drainage, would improve surface water quality. In this paper, a series of laboratory experiments were conducted to assess the effects of various soil and hydraulic factors on chemical transfer from soil to surface runoff. The factors include maximum depth of ponding water on soil surface, initial volumetric water content of soil, depth of soil with low porosity, type or texture of soil and condition of drainage. In the experiments, two soils, sand and loam, mixed with different quantities of soluble KCl were filled in the sandboxes and prepared under different initial saturated conditions. Simulated rainfall induced surface runoff are operated in the soils, and various ponding water depths on soil surface are simulated. Flow rates and KCl concentration of surface runoff are measured during the experiments. The following conclusions are made from the study results: (1) KCl concentration in surface runoff water would decrease with the increase of the maximum depth of ponding water on soil surface; (2) KCl concentration in surface runoff water would increase with the increase of initial volumetric water content in the soil; (3) smaller depth of soil with less porosity or deeper depth of soil with larger porosity leads to less KCl transfer to surface runoff; (4) the soil with finer texture, such as loam, could keep more fertilizer in soil, which will result in more KCl concentration in surface runoff; and (5) good subsurface drainage condition will increase the infiltration and drainage rates during rainfall event and will decrease KCl concentration in surface runoff. Therefore, it is necessary to reuse drained fertile water effectively during rainfall, without polluting groundwater. These study results should be considered in agriculture management to reduce soluble chemical transfer from soil to surface runoff for reducing non-point sources pollution.

  15. Evaluating MODIS snow products for modelling snowmelt runoff: Case study of the Rio Grande headwaters

    Science.gov (United States)

    Steele, Caitriana; Dialesandro, John; James, Darren; Elias, Emile; Rango, Albert; Bleiweiss, Max

    2017-12-01

    Snow-covered area (SCA) is a key variable in the Snowmelt-Runoff Model (SRM) and in other models for simulating discharge from snowmelt. Landsat Thematic Mapper (TM), Enhanced Thematic Mapper (ETM +) or Operational Land Imager (OLI) provide remotely sensed data at an appropriate spatial resolution for mapping SCA in small headwater basins, but the temporal resolution of the data is low and may not always provide sufficient cloud-free dates. The coarser spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) offers better temporal resolution and in cloudy years, MODIS data offer the best alternative for mapping snow cover when finer spatial resolution data are unavailable. However, MODIS' coarse spatial resolution (500 m) can obscure fine spatial patterning in snow cover and some MODIS products are not sensitive to end-of-season snow cover. In this study, we aimed to test MODIS snow products for use in simulating snowmelt runoff from smaller headwater basins by a) comparing maps of TM and MODIS-based SCA and b) determining how SRM streamflow simulations are changed by the different estimates of seasonal snow depletion. We compared gridded MODIS snow products (Collection 5 MOD10A1 fractional and binary SCA; SCA derived from Collection 6 MOD10A1 Normalised Difference Snow Index (NDSI) Snow Cover), and the MODIS Snow Covered-Area and Grain size retrieval (MODSCAG) canopy-corrected fractional SCA (SCAMG), with reference SCA maps (SCAREF) generated from binary classification of TM imagery. SCAMG showed strong agreement with SCAREF; excluding true negatives (where both methods agreed no snow was present) the median percent difference between SCAREF and SCAMG ranged between -2.4% and 4.7%. We simulated runoff for each of the four study years using SRM populated with and calibrated for snow depletion curves derived from SCAREF. We then substituted in each of the MODIS-derived depletion curves. With efficiency coefficients ranging between 0.73 and 0.93, SRM

  16. A pilot study to evaluate runoff quantity from green roofs.

    Science.gov (United States)

    Lee, Ju Young; Lee, Min Jung; Han, Mooyoung

    2015-04-01

    The use of green roofs is gaining increased recognition in many countries as a solution that can be used to improve environmental quality and reduce runoff quantity. To achieve these goals, pilot-scale green roof assemblies have been constructed and operated in an urban setting. From a stormwater management perspective, green roofs are 42.8-60.8% effective in reducing runoff for 200 mm soil depth and 13.8-34.4% effective in reducing runoff for 150 mm soil depth. By using Spearman rank correlation analysis, high rainfall intensity was shown to have a negative relationship with delayed occurrence time, demonstrating that the soil media in green roofs do not efficiently retain rainwater. Increasing the number of antecedent dry days can help to improve water retention capacity and delay occurrence time. From the viewpoint of runoff water quality, green roofs are regarded as the best management practice by filtration and adsorption through growth media (soil). Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Study of the Spatiotemporal Characteristics of Meltwater Contribution to the Total Runoff in the Upper Changjiang River Basin

    Directory of Open Access Journals (Sweden)

    Yuan-Hao Fang

    2017-02-01

    Full Text Available Melt runoff (MR contributes significantly to the total runoff in many river basins. Knowledge of the meltwater contribution (MCR, defined as the ratio of MR to the total runoff to the total runoff benefits water resource management and flood control. A process-based land surface model, Noah-MP, was used to investigate the spatiotemporal characteristics of MR and MCR in the Upper Changjiang River (as known as Yangtze River Basin (UCRB located in southwestern China. The model was first calibrated and validated using snow cover fraction (SCF, runoff, and evapotranspiration (ET data. The calibrated model was then used to perform two numerical experiments from 1981 to 2010: control experiment that considers MR and an alternative experiment that MR is removed. The difference between two experiments was used to quantify MR and MCR. The results show that in the entire UCRB, MCR was approximately 2.0% during the study period; however, MCR exhibited notable spatiotemporal variability. Four sub-regions over the Qinghai-Tibet Plateau (QTP showed significant annual MCR ranging from 3.9% to 6.0%, while two sub-regions in the low plain regions showed negligible annual MCR. The spatial distribution of MCR was generally consistent with the distribution of glaciers and elevation distribution. Mann-Kendall (M-K tests of the long-term annual MCR indicated that the four sub-regions in QTP exhibited increasing trends ranging from 0.01%/year to 0.21%/year during the study period but only one displayed statistically significant trend. No trends were found for the peak time (PT of MR and MCR, in contrast, advancing trend were observed for the center time (CT of MR, ranging from 0.01 months/year to 0.02 months/year. These trends are related to the changes of air temperature and precipitation in the study area.

  18. Impacts of Spatial Distribution of Impervious Areas on Runoff Response of Hillslope Catchments: Simulation Study

    Science.gov (United States)

    This study analyzes variations in the model-projected changes in catchment runoff response after urbanization that stem from variations in the spatial distribution of impervious areas, interevent differences in temporal rainfall structure, and antecedent soil moisture (ASM). In t...

  19. Isotope techniques in catchment behaviour studies with particular emphasis on snowmelt runoff investigations

    International Nuclear Information System (INIS)

    Yurtsever, Y.

    1984-05-01

    The dynamics of runoff occurring mainly by snowmelt have been investigated by the aid of environmental isotopes. Regular samples collected from river water and snow cover throughout 1978 to 1981 at two selected catchment basins in eastern Turkey were analysed for their oxygen-18, deuterium and tritium contents. The tritium results together with detailed hydrological and hydro-meteorological data have enabled to study the time distribution of various component flow systems involved in the total runoff resulting from snowmelt

  20. Normetex Pump Alternatives Study

    International Nuclear Information System (INIS)

    Clark, Elliot A.

    2013-01-01

    A mainstay pump for tritium systems, the Normetex scroll pump, is currently unavailable because the Normetex company went out of business. This pump was an all-metal scroll pump that served tritium processing facilities very well. Current tritium system operators are evaluating replacement pumps for the Normetex pump and for general used in tritium service. An all-metal equivalent alternative to the Normetex pump has not yet been identified. 1. The ideal replacement tritium pump would be hermetically sealed and contain no polymer components or oils. Polymers and oils degrade over time when they contact ionizing radiation. 2. Halogenated polymers (containing fluorine, chlorine, or both) and oils are commonly found in pumps. These materials have many properties that surpass those of hydrocarbon-based polymers and oils, including thermal stability (higher operating temperature) and better chemical resistance. Unfortunately, they are less resistant to degradation from ionizing radiation than hydrocarbon-based materials (in general). 3. Polymers and oils can form gaseous, condensable (HF, TF), liquid, and solid species when exposed to ionizing radiation. For example, halogenated polymers form HF and HCl, which are extremely corrosive upon reaction with water. If a pump containing polymers or oils must be used in a tritium system, the system must be designed to be able to process the unwanted by-products. Design features to mitigate degradation products include filters and chemical or physical traps (eg. cold traps, oil traps). 4. Polymer components can work in tritium systems, but must be replaced regularly. Polymer components performance should be monitored or be regularly tested, and regular replacement of components should be viewed as an expected normal event. A radioactive waste stream must be established to dispose of used polymer components and oil with an approved disposal plan developed based on the facility location and its regulators. Polymers have varying

  1. Runoff prediction using rainfall data from microwave links: Tabor case study.

    Science.gov (United States)

    Stransky, David; Fencl, Martin; Bares, Vojtech

    2018-05-01

    Rainfall spatio-temporal distribution is of great concern for rainfall-runoff modellers. Standard rainfall observations are, however, often scarce and/or expensive to obtain. Thus, rainfall observations from non-traditional sensors such as commercial microwave links (CMLs) represent a promising alternative. In this paper, rainfall observations from a municipal rain gauge (RG) monitoring network were complemented by CMLs and used as an input to a standard urban drainage model operated by the water utility of the Tabor agglomeration (CZ). Two rainfall datasets were used for runoff predictions: (i) the municipal RG network, i.e. the observation layout used by the water utility, and (ii) CMLs adjusted by the municipal RGs. The performance was evaluated in terms of runoff volumes and hydrograph shapes. The use of CMLs did not lead to distinctively better predictions in terms of runoff volumes; however, CMLs outperformed RGs used alone when reproducing a hydrograph's dynamics (peak discharges, Nash-Sutcliffe coefficient and hydrograph's rising limb timing). This finding is promising for number of urban drainage tasks working with dynamics of the flow. Moreover, CML data can be obtained from a telecommunication operator's data cloud at virtually no cost. That makes their use attractive for cities unable to improve their monitoring infrastructure for economic or organizational reasons.

  2. A study of regional trends in annual and seasonal precipitation and runoff series

    Energy Technology Data Exchange (ETDEWEB)

    Tveito, O.E.; Hisdal, H.

    1994-03-10

    In this study long and homogeneous time series of runoff and precipitation are studied to identify variations in time and space. The method of empirical orthogonal functions (EOF-method) is applied. Both annual observations, smoothed (using Gauss filter) and seasonal values are analyzed. The analysis shows that the temporal variations in runoff and precipitation coincide. The deviations occurring in the seasonal values are caused by snow accumulation and snow melt. In the filtered series temporal trends are found. A comparison between the different normal periods has been carried out for precipitation. The 1900-30 and 1960-90 periods differ from the 1930-60 period. This may be caused by different weather types dominating the different periods. The different weather types are reflected in different empirical orthogonal functions. This is verified by regional studies. The coinciding patterns in runoff and precipitation are important aspects in climate studies and for extrapolation purposes. 11 refs., 20 figs., 1 tab.

  3. Runoff of pesticides from rice fields in the Ile de Camargue (Rhone river delta, France): Field study and modeling

    International Nuclear Information System (INIS)

    Comoretto, Laetitia; Arfib, Bruno; Talva, Romain; Chauvelon, Philippe; Pichaud, Marc; Chiron, Serge; Hoehener, Patrick

    2008-01-01

    A field study on the runoff of pesticides was conducted during the cultivation period in 2004 on a hydraulically isolated rice farm of 120 ha surface with one central water outlet. Four pesticides were studied: Alphamethrin, MCPA, Oxadiazon, and Pretilachlor. Alphamethrin concentrations in runoff never exceeded 0.001 μg L -1 . The three other pesticides were found in concentrations between 5.2 and 28.2 μg L -1 in the runoff water shortly after the application and decreased thereafter. The data for MCPA compared reasonably well with predictions by an analytical runoff model, accounting for volatilization, degradation, leaching to groundwater, and sorption to soil. The runoff model estimated that runoff accounted for as much as 18-42% of mass loss for MCPA. Less runoff is observed and predicted for Oxadiazon and Pretilachlor. It was concluded that runoff from rice paddies carries important loads of dissolved pesticides to the wetlands in the Ile de Camargue, and that the model can be used to predict this runoff. - Runoff of dissolved pesticides was measured on a rice farm in the Camargue (France) and modeled with an analytical model

  4. Stormwater runoff plumes in the Southern California Bight: A comparison study with SAR and MODIS imagery.

    Science.gov (United States)

    Holt, Benjamin; Trinh, Rebecca; Gierach, Michelle M

    2017-05-15

    Stormwater runoff is the largest source of pollution in the Southern California Bight (SCB), resulting from untreated runoff and pollutants from urban watersheds entering the coastal waters after rainstorms. We make use of both satellite SAR and MODIS-Aqua ocean color imagery to examine two different components of runoff plumes, the surface slick and the sediment discharge. We expand on earlier satellite SAR studies by examining an extensive collection of multi-platform SAR imagery, spanning from 1992 to 2014, that provides a more comprehensive view of the plume surface slick characteristics, illustrated with distribution maps of the extent and flow direction of the plumes. The SAR-detected surface plumes are compared with coincident rain and runoff measurements, and with available measured shoreline fecal bacteria loads. We illustrate differences in the detection of SAR surface plumes with the sediment-related discharge plumes derived from MODIS imagery. A conceptual satellite stormwater runoff monitoring approach is presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Methodology and significance of studies of atmospheric deposition in highway runoff

    Science.gov (United States)

    Colman, John A.; Rice, Karen C.; Willoughby, Timothy C.

    2001-01-01

    Atmospheric deposition and the processes that are involved in causing and altering atmospheric deposition in relation to highway surfaces and runoff were evaluated nationwide. Wet deposition is more easily monitored than dry deposition, and data on wet deposition are available for major elements and water properties (constituents affecting acid deposition) from the inter-agency National Atmospheric Deposition Program/ National Trends Network (NADP/NTN). Many trace constituents (metals and organic compounds) of interest in highway runoff loads, however, are not included in the NADP/NTN. Dry deposition, which constitutes a large part of total atmospheric deposition for many constituents in highway runoff loads, is difficult to monitor accurately. Dry-deposition rates are not widely available.Many of the highway-runoff investigations that have addressed atmospheric-deposition sources have had flawed investigative designs or problems with methodology. Some results may be incorrect because of reliance on time-aggregated data collected during a period of changing atmospheric emissions. None of the investigations used methods that could accurately quantify the part of highway runoff load that can be attributed to ambient atmospheric deposition. Lack of information about accurate ambient deposition rates and runoff loads was part of the problem. Samples collected to compute the rates and loads were collected without clean-sampling methods or sampler protocols, and without quality-assurance procedures that could validate the data. Massbudget calculations comparing deposition and runoff did not consider loss of deposited material during on-highway processing. Loss of deposited particles from highway travel lanes could be large, as has been determined in labeled particle studies, because of resuspension caused by turbulence from passing traffic. Although a cause of resuspension of large particles, traffic turbulence may increase the rate of deposition for small particles and

  6. Inorganic constituents in surface runoff from urbanised areas in winter: the case study of the city of Brest, Belarus

    Directory of Open Access Journals (Sweden)

    Ina Bulskaya

    2014-03-01

    Full Text Available The aim of this paper was to study the inorganic constituents of snow and snowmelt surface runoff in a case study of the city of Brest and to indicate components that could pose a threat to the environment. Samples of snow and snowmelt runoff were analysed for the following parameters: total suspended solids, pH, the contents of nitrate, phosphate and ammonium ions, and of heavy metals. The concentrations of most of these pollutants were higher in the snowmelt runoff than in snow. The concentrations of pollutants in the snowmelt surface runoff exceeded the levels established by national regulations (maximum permissible concentrations.

  7. Development of a portable field rainfall simulator for use in hillside vineyard runoff and erosion studies

    Science.gov (United States)

    Battany, M. C.; Grismer, M. E.

    2000-04-01

    An inexpensive, mobile field rainfall simulator and runoff plot frame were developed for use on hillside vineyards. The simulator framework and components were lightweight, readily available and easily manageable such that they can be handled by one person during transport, set-up and operation. The vineyard rainfall simulator was simpler than many of the machines in recent use for similar studies, yet offered equal or improved performance for small-plot studies. The system developed consistent sized 2·58 mm raindrops at intensities ranging from 20 to 90 mm/h. The average distribution uniformity coefficient at an intensity of 60 mm/h was 91·7%, with a deviation of only 2·2%. This coefficient was similar to the range reported for a more complex rotating disk simulator, and was notably greater than that obtained for other similar devices. The system water capacity of 40 l allowed for 1-h storm durations at 60 mm/h, usually sufficient time for commencement of erosion and runoff. The runoff plot frame was designed to be quickly installed, and to discourage sediment deposition in the routing of runoff to collect containers.

  8. Urban Land: Study of Surface Run-off Composition and Its Dynamics

    Science.gov (United States)

    Palagin, E. D.; Gridneva, M. A.; Bykova, P. G.

    2017-11-01

    The qualitative composition of urban land surface run-off is liable to significant variations. To study surface run-off dynamics, to examine its behaviour and to discover reasons of these variations, it is relevant to use the mathematical apparatus technique of time series analysis. A seasonal decomposition procedure was applied to a temporary series of monthly dynamics with the annual frequency of seasonal variations in connection with a multiplicative model. The results of the quantitative chemical analysis of surface wastewater of the 22nd Partsjezd outlet in Samara for the period of 2004-2016 were used as basic data. As a result of the analysis, a seasonal pattern of variations in the composition of surface run-off in Samara was identified. Seasonal indices upon 15 waste-water quality indicators were defined. BOD (full), suspended materials, mineralization, chlorides, sulphates, ammonium-ion, nitrite-anion, nitrate-anion, phosphates (phosphorus), iron general, copper, zinc, aluminium, petroleum products, synthetic surfactants (anion-active). Based on the seasonal decomposition of the time series data, the contribution of trends, seasonal and accidental components of the variability of the surface run-off indicators was estimated.

  9. Benzalkonium runoff from roofs treated with biocide products - In situ pilot-scale study.

    Science.gov (United States)

    Gromaire, M C; Van de Voorde, A; Lorgeoux, C; Chebbo, G

    2015-09-15

    Roof maintenance practices often involve the application of biocide products to fight against moss, lichens and algae. The main component of these products is benzalkonium chloride, a mixture of alkyl benzyl dimethyl ammonium chlorides with mainly C12 and C14 alkyl chain lengths, which is toxic for the aquatic environment. This paper describes, on the basis of an in-situ pilot scale study, the evolution of roof runoff contamination over a one year period following the biocide treatment of roof frames. Results show a major contamination of roof runoff immediately after treatment (from 5 to 30 mg/L), followed by an exponential decrease. 175-375 mm of cumulated rainfall is needed before the runoff concentrations become less than EC50 values for fish (280 μg/l). The residual concentration in the runoff water remains above 4 μg/L even after 640 mm of rainfall. The level of benzalkonium ions leaching depends on the roofing material, with lower concentrations and total mass leached from ceramic tiles than from concrete tiles, and on the state of the tile (new or worn out). Mass balance calculations indicate that a large part of the mass of benzalkonium compounds applied to the tiles is lost, probably due to biodegradation processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Experimental study of water fluxes in a residential area: 2. Road infiltration, runoff and evaporation

    Science.gov (United States)

    Ragab, R.; Rosier, P.; Dixon, A.; Bromley, J.; Cooper, J. D.

    2003-08-01

    Lack of accurate data has led some hydrologists and city planners to assume that urban infiltration is zero and runoff is 100% of the rainfall. These assumptions lead to an over estimation of road runoff volume and an underestimation of direct recharge to groundwater, which is already rising under some UK cities. This study investigates infiltration and runoff processes and quantifies the percentage of rainfall that contributes to storm drainage, and that which infiltrates through different types of road surface. Access tubes were installed for measuring soil water content using a neutron probe in three car parks, a road and a grass site at the Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford. Storm drainage was recorded at the exit of the Thamesmead Estate in Crowmarsh Gifford, just before the drain joins the River Thames at Wallingford. Rainfall and water table depth were also recorded. Weekly measurements of soil moisture content indicated that the top 40 cm layer is not influenced by water-table fluctuations and, therefore, positive changes in soil moisture could be attributed to infiltration of rainfall through the surface. Depending on the nature of the surface, subsurface layers, level of traffic, etc., between 6 and 9% of rainfall was found to infiltrate through the road surfaces studied. The storm drainage generated by road runoff revealed a flow pattern similar to that of the receiving watercourse (River Thames) and increased with the increase of infiltration and soil water content below the road surface. The ratio of runoff to rainfall was 0·7, 0·9 and 0·5 for annual, winter (October-March) and summer (April-September) respectively. As the results of the infiltration indicated that 6 to 9% of annual rainfall infiltrates through the road surface, this means that evaporation represents, 21-24% of annual rainfall, with more evaporation taking place during summer than winter.

  11. SWAT use of gridded observations for simulating runoff - a Vietnam river basin study

    Science.gov (United States)

    Vu, M. T.; Raghavan, S. V.; Liong, S. Y.

    2012-08-01

    Many research studies that focus on basin hydrology have applied the SWAT model using station data to simulate runoff. But over regions lacking robust station data, there is a problem of applying the model to study the hydrological responses. For some countries and remote areas, the rainfall data availability might be a constraint due to many different reasons such as lacking of technology, war time and financial limitation that lead to difficulty in constructing the runoff data. To overcome such a limitation, this research study uses some of the available globally gridded high resolution precipitation datasets to simulate runoff. Five popular gridded observation precipitation datasets: (1) Asian Precipitation Highly Resolved Observational Data Integration Towards the Evaluation of Water Resources (APHRODITE), (2) Tropical Rainfall Measuring Mission (TRMM), (3) Precipitation Estimation from Remote Sensing Information using Artificial Neural Network (PERSIANN), (4) Global Precipitation Climatology Project (GPCP), (5) a modified version of Global Historical Climatology Network (GHCN2) and one reanalysis dataset, National Centers for Environment Prediction/National Center for Atmospheric Research (NCEP/NCAR) are used to simulate runoff over the Dak Bla river (a small tributary of the Mekong River) in Vietnam. Wherever possible, available station data are also used for comparison. Bilinear interpolation of these gridded datasets is used to input the precipitation data at the closest grid points to the station locations. Sensitivity Analysis and Auto-calibration are performed for the SWAT model. The Nash-Sutcliffe Efficiency (NSE) and Coefficient of Determination (R2) indices are used to benchmark the model performance. Results indicate that the APHRODITE dataset performed very well on a daily scale simulation of discharge having a good NSE of 0.54 and R2 of 0.55, when compared to the discharge simulation using station data (0.68 and 0.71). The GPCP proved to be the

  12. SWAT use of gridded observations for simulating runoff – a Vietnam river basin study

    Directory of Open Access Journals (Sweden)

    M. T. Vu

    2012-08-01

    Full Text Available Many research studies that focus on basin hydrology have applied the SWAT model using station data to simulate runoff. But over regions lacking robust station data, there is a problem of applying the model to study the hydrological responses. For some countries and remote areas, the rainfall data availability might be a constraint due to many different reasons such as lacking of technology, war time and financial limitation that lead to difficulty in constructing the runoff data. To overcome such a limitation, this research study uses some of the available globally gridded high resolution precipitation datasets to simulate runoff. Five popular gridded observation precipitation datasets: (1 Asian Precipitation Highly Resolved Observational Data Integration Towards the Evaluation of Water Resources (APHRODITE, (2 Tropical Rainfall Measuring Mission (TRMM, (3 Precipitation Estimation from Remote Sensing Information using Artificial Neural Network (PERSIANN, (4 Global Precipitation Climatology Project (GPCP, (5 a modified version of Global Historical Climatology Network (GHCN2 and one reanalysis dataset, National Centers for Environment Prediction/National Center for Atmospheric Research (NCEP/NCAR are used to simulate runoff over the Dak Bla river (a small tributary of the Mekong River in Vietnam. Wherever possible, available station data are also used for comparison. Bilinear interpolation of these gridded datasets is used to input the precipitation data at the closest grid points to the station locations. Sensitivity Analysis and Auto-calibration are performed for the SWAT model. The Nash-Sutcliffe Efficiency (NSE and Coefficient of Determination (R2 indices are used to benchmark the model performance. Results indicate that the APHRODITE dataset performed very well on a daily scale simulation of discharge having a good NSE of 0.54 and R2 of 0.55, when compared to the discharge simulation using station data (0

  13. Studies on the discharge from Vernagtferner with special regard to meltwater within the firn aquifer runoff

    International Nuclear Information System (INIS)

    Oerter, H.

    1981-08-01

    The report describes the runoff from a glacier with the runoff from Vernagtferner glacier as an example. Especially the storage and drainage processes in the firn body and the contribution of the snow meltwater to the total runoff are described using dye tracers and the environmental natural isotopes D, T and O-18. (orig./HP) [de

  14. Rainfall simulations to study the types of groundcover on surface runoff and soil erosion in Champagne vineyards in France

    Science.gov (United States)

    Xavier, Morvan; Christophe, Naisse; Issa Oumarou, Malam; Jean-François, Desprats; Anne, Combaud; Olivier, Cerdan

    2015-04-01

    In the literature, grass cover is often considered to be one of the best methods of limiting runoff in the vineyards; But results can vary, especially when the plot area is Champagne vineyards in France, was to quantify the influence of the cultivation practices in the inter-rows of vines and determine the influence of the density of the grass cover in the wheel tracks on the surface runoff and soil erosion in experimental plots of 0.25 m2 under simulated rainfall. Three types of ground cover were studied. In the bark-and-vine-prunings plots, the runoff coefficient ranged from 1.3 to 4.0% and soil losses were <1 g/m²/h. In the bare soil plot, the highest runoff coefficient of the study was found (80.0%) and soil losses reached 7.4 g/m²/h. In the grass cover plots, the runoff coefficient and amount of eroded soil were highly variable: the runoff coefficients ranged from 0.4 to 77.0%, and soil losses were between less than 1 and 13.4 g/m²/h. Soil type, soil moisture, slope and agricultural practices did not account for the variability. In fact, the density of grass cover in the wheel tracks explained a portion of this variability. The lack of grass in the centre of the inter-row allowed for a preferential flow and created an erosion line in the wheel tracks where the soil was compacted. This study showed that grass cover in a vineyard was not necessarily sufficient to reduce surface runoff and prevent soil erosion. To be effective, the grass cover must be dense enough in the wheel tracks of agricultural machinery to avoid runoff coefficients close to those achieved with bare soil.

  15. A Preliminary Study on the Measurement of Sediment Concentration in Hill-Slope Runoff with an Electrolyte Tracer

    Directory of Open Access Journals (Sweden)

    Xiaonan Shi Fan Zhang

    2012-01-01

    Full Text Available Sediment concentration in hill-slope runoff is an important index for soil erosion. Developing a reliable and portable measuring system of sediment concentration is a core issue for soil and water conservation study, especially for the Tibetan Plateau under unfavorable climate and terrain conditions for field investigation. Challenges include uneven distribution of sediment across a runoff section as well as difficulty in detecting a wide range of particle sizes. An electrolyte tracer, with the advantage of uniform distribution and its widely used electric-conductivity sensor, can avoid the problems of direct measurement of sediment. A new measurement method of sediment concentration in runoff with an electrolyte tracer is proposed based on a premise that sediment concentration is closely correlated with hydrodynamic dispersion coefficient of solute in runoff. In this study, an experiment system of hill-slope runoff with an electrolyte tracer and sediments is first designed. Second, two model parameters in the advective-dispersive equation of solute transport, flow velocity and diffusion coefficient, are inversely estimated by calibrating the observed concentrations of an electrolyte tracer. And third, the relationship between sediment concentrations and hydrodynamic dispersion coefficients are defined through specified regression. As a result, a measurement system of sediment concentration in hill-slope runoff with an electrolyte tracer is primarily established by integrating the relationship of variables, experiment system, and model theory.

  16. Study on Variations in Climatic Variables and Their Influence on Runoff in the Manas River Basin, China

    Directory of Open Access Journals (Sweden)

    Lei Ren

    2017-04-01

    Full Text Available Climate change in Northwest China could lead to the change of the hydrological cycle and water resources. This paper assessed the influence of climate change on runoff in the Manas River basin as follows. First, the temporal trends and abrupt change points of runoff, precipitation, and mean, lowest and highest temperature in yearly scale during the period of 1961–2015 were analyzed using the Mann-Kendall (MK test. Then the correlation between runoff and climatic variables was characterized in a monthly, seasonal and yearly scale using the partial correlation method. Furthermore, three global climate models (GCMs from Coupled Model Inter-comparison Project Phase 5 (CMIP5 were bias-corrected using Equidistant Cumulative Distribution Functions (EDCDF method to reveal the future climate change during the period from 2021 to 2060 compared with the baseline period of 1961–2000. The influence of climate change on runoff was studied by simulating the runoff with the GCMs using a modified TOPMODEL considering the future snowmelt during the period from 2021 to 2060. The results showed that the runoff, precipitation, and mean, lowest and highest temperature all presented an increasing trend in yearly scale during the period of 1961–2015, and their abrupt change points were at a similar time; the runoff series was more strongly related to temperature than to precipitation in the spring, autumn and yearly scales, and the opposite was true in winter. All GCMs projected precipitation and temperature, and the runoff simulated with these GCMs were predicted to increase in the period from 2021 to 2060 compared with the baseline period of 1961–2000. These findings provide valuable information for assessing the influence of climate change on water resources in the Manas River basin, and references for water management in such regions.

  17. Studies and Analysis of the Effectiveness of Stormwater Runoff Purification Equipment in Vilnius

    Directory of Open Access Journals (Sweden)

    Egidija Jaruševičiūtė

    2011-02-01

    Full Text Available In order to protect the natural environment from pollution, pollutant reduction in the stormwater runoff of urban areas is a particularly relevant factor. Uneven surface water flow and changes in pollutant concentration complicate conventional matching techniques and processes as well as prolong the duration of time which requires a comprehensive study in this area. Therefore, experiments on inflow stormwater turbidity and impurity with suspended solids and petroleum products were carried out according to the prepared sample collecting methodology. The study evaluated the effectiveness of cleaning a stormwater treatment plant along the settlement chamber in the chosen points. The settling time of impurities found in stormwater was analyzed under the presence of ideal conditions in the laboratory. The conducted experiments established dependence between suspended solids and turbidity. Stormwater pollution by SS was reduced only to 21–35% after heavy rain or a snow melting period in treatment plants. Keywords: storm water runoff, cleaning stormwater treatment plant, pollutants, turbidity, suspended solids, petrol products.DOI: 10.3846/mla.2010.087

  18. Episodic runoff generation at Central European headwater catchments studied using water isotope concentration signals

    Czech Academy of Sciences Publication Activity Database

    Votrubová, J.; Dohnal, M.; Vogel, T.; Šanda, M.; Tesař, Miroslav

    2017-01-01

    Roč. 65, č. 2 (2017), s. 114-122 ISSN 0042-790X Grant - others:Grantová agentura České republiky (GA ČR)(CZ) GC14-15201J Institutional support: RVO:67985874 Keywords : O isotope * headwater catchment runoff * subsurface runoff * tracer * rainfall-runoff episodes Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Hydrology Impact factor: 1.654, year: 2016

  19. The Hachioji Experimental Basin Study — Storm runoff processes and the mechanism of its generation

    Science.gov (United States)

    Tanaka, T.; Yasuhara, M.; Sakai, H.; Marui, A.

    1988-09-01

    The study discusses storm runoff processes and the mechanism of its generation in relation to dynamic responses of subsurface water in a small forested drainage basin located in the western suburbs of Tokyo, Japan. Intensive field observations were carried out for the period 1980-1983. In the drainage basin overland flow occurred from restricted areas on the valley floor. No significant overland flow was produced on the steep hillside slopes even during a heavy storm event. The maximum extent of the saturated area occupied only 1-4% of the total basin area. The main source of storm runoff was groundwater flow. More than 90% of the total discharge was due to groundwater flow and the surface flow component contributed less than 10%. The rapid and large amounts of groundwater discharge during a storm event could not be explained solely by the traditional concept of Darcian matrix flow. These phenomena were mainly attributed to rapid flow such as pipe flow which has velocities about as high as those of surface flows. The pulsating flow phenomenon was observed as a characteristic of pipe flow.

  20. Application of MIKE SHE to study the impact of coal mining on river runoff in Gujiao mining area, Shanxi, China.

    Directory of Open Access Journals (Sweden)

    Jianhua Ping

    Full Text Available Coal mining is one of the core industries that contribute to the economic development of a country but deteriorate the environment. Being the primary source of energy, coal has become essential to meet the energy demand of a country. It is excavated by both opencast and underground mining methods and affects the environment, especially hydrological cycle, by discharging huge amounts of mine water. Natural hydrological processes have been well known to be vulnerable to human activities, especially large scale mining activities, which inevitably generate surface cracks and subsidence. It is therefore valuable to assess the impact of mining on river runoff for the sustainable development of regional economy. In this paper, the impact of coal mining on river runoff is assessed in one of the national key coal mining sites, Gujiao mining area, Shanxi Province, China. The characteristics of water cycle are described, the similarities and differences of runoff formation are analyzed in both coal mining and pre-mining periods. The integrated distributed hydrological model named MIKE SHE is employed to simulate and evaluate the influence of coal mining on river runoff. The study shows that mining one ton of raw coal leads to the reduction of river runoff by 2.87 m3 between 1981 and 2008, of which the surface runoff decreases by 0.24 m3 and the baseflow by 2.63 m3. The reduction degree of river runoff for mining one ton of raw coal shows an increasing trend over years. The current study also reveals that large scale coal mining initiates the formation of surface cracks and subsidence, which intercepts overland flow and enhances precipitation infiltration. Together with mine drainage, the natural hydrological processes and the stream flows have been altered and the river run off has been greatly reduced.

  1. Application of MIKE SHE to study the impact of coal mining on river runoff in Gujiao mining area, Shanxi, China.

    Science.gov (United States)

    Ping, Jianhua; Yan, Shiyan; Gu, Pan; Wu, Zening; Hu, Caihong

    2017-01-01

    Coal mining is one of the core industries that contribute to the economic development of a country but deteriorate the environment. Being the primary source of energy, coal has become essential to meet the energy demand of a country. It is excavated by both opencast and underground mining methods and affects the environment, especially hydrological cycle, by discharging huge amounts of mine water. Natural hydrological processes have been well known to be vulnerable to human activities, especially large scale mining activities, which inevitably generate surface cracks and subsidence. It is therefore valuable to assess the impact of mining on river runoff for the sustainable development of regional economy. In this paper, the impact of coal mining on river runoff is assessed in one of the national key coal mining sites, Gujiao mining area, Shanxi Province, China. The characteristics of water cycle are described, the similarities and differences of runoff formation are analyzed in both coal mining and pre-mining periods. The integrated distributed hydrological model named MIKE SHE is employed to simulate and evaluate the influence of coal mining on river runoff. The study shows that mining one ton of raw coal leads to the reduction of river runoff by 2.87 m3 between 1981 and 2008, of which the surface runoff decreases by 0.24 m3 and the baseflow by 2.63 m3. The reduction degree of river runoff for mining one ton of raw coal shows an increasing trend over years. The current study also reveals that large scale coal mining initiates the formation of surface cracks and subsidence, which intercepts overland flow and enhances precipitation infiltration. Together with mine drainage, the natural hydrological processes and the stream flows have been altered and the river run off has been greatly reduced.

  2. The economic benefits of rainwater-runoff reduction by urban green spaces: a case study in Beijing, China.

    Science.gov (United States)

    Zhang, Biao; Xie, Gaodi; Zhang, Canqiang; Zhang, Jing

    2012-06-15

    Urbanization involves the replacement of vegetated surfaces with impervious built surfaces, and it often results in an increase in the rate and volume of rainwater surface runoff. Urban green spaces play a positive role in rainwater-runoff reduction. However, few studies have explored the benefits of rainwater-runoff reduction by urban green spaces. Based on inventory data of urban green spaces in Beijing, the paper evaluated the economic benefits of rainwater-runoff reduction by urban green spaces, using the rainwater-runoff-coefficient method as well as the economic valuation methods. The results showed that, 2494 cubic meters of potential runoff was reduced per hectare of green area and a total volume of 154 million cubic meters rainwater was stored in these urban green spaces, which almost corresponds to the annual water needs of the urban ecological landscape in Beijing. The total economic benefit was 1.34 billion RMB in 2009 (RMB: Chinese currency, US$1=RMB6.83), which is equivalent to three-quarters of the maintenance cost of Beijing's green spaces; the value of rainwater-runoff reduction was 21.77 thousand RMB per hectare. In addition, the benefits in different districts and counties were ranked in the same order as urban green areas, and the average benefits per hectare of green space showed different trends, which may be related to the impervious surface index in different regions. This research will contribute to an understanding of the role that Beijing's green spaces play in rainwater regulation and in the creation and scientific management of urban green spaces. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Study of the relationship between runoff, rainfall and evaporation watershed in the southern zone of the Mediterranean (case of Algeria)

    International Nuclear Information System (INIS)

    Benlarbi, D.; Boutoutaou, D.; Saker, M.L.

    2015-01-01

    Water resources in Algeria are not distributed evenly inspace and time that engenders enormous difficulties for their mobilization. Water shortage is becoming a major problem. A number of regions already suffers from water deficiency and the others will soon follow. To solve this problem, the construction of new dams becomes indispensable. Through the hydrological studies and the exploitation of future dams, the evaluation of wateryield in sites of these structures is indispensable. At present, the calculation of the interannual runoff in absence of data for the not gauged watercourse is determined from empirical formulae established especially for the climatic and geographical conditions of Algeria. Unfortunately, all these formulas do not provide accurate results.Watersheds which were used in the study represent almost the entire surface of Northern Algeria whose number is 106 basins.The objective of the present study is to establish working tools, allowing the planners and the managers to determine the value of the interannual runoff of watershed for the climatic conditions of Algeria without going through the empirical formulae often used in the absence of measurable dataand leading to absurd errors.The calculation parameters for interannual runoff from the proposed model are standard meteorological data (air temperature, humidity and pluviometry), always available and periodically broadcastedby meteorological services and hydrology of Algeria. Runoff values calculated by the model are close to the values of measured runoff.The difference between them didnot exceed 15 to 20%. (author)

  4. Experimental study on influence of vegetation coverage on runoff in wind-water erosion crisscross region

    Science.gov (United States)

    Wang, Jinhua; Zhang, Ronggang; Sun, Juan

    2018-02-01

    Using artificial rainfall simulation method, 23 simulation experiments were carried out in water-wind erosion crisscross region in order to analyze the influence of vegetation coverage on runoff and sediment yield. The experimental plots are standard plots with a length of 20m, width of 5m and slope of 15 degrees. The simulation experiments were conducted in different vegetation coverage experimental plots based on three different rainfall intensities. According to the experimental observation data, the influence of vegetation coverage on runoff and infiltration was analyzed. Vegetation coverage has a significant impact on runoff, and the higher the vegetation coverage is, the smaller the runoff is. Under the condition of 0.6mm/min rainfall intensity, the runoff volume from the experimental plot with 18% vegetation coverage was 1.2 times of the runoff from the experimental with 30% vegetation coverage. What’s more, the difference of runoff is more obvious in higher rainfall intensity. If the rainfall intensity reaches 1.32mm/min, the runoff from the experimental plot with 11% vegetation coverage is about 2 times as large as the runoff from the experimental plot with 53%vegetation coverage. Under the condition of small rainfall intensity, the starting time of runoff in the experimental plot with higher vegetation coverage is later than that in the experimental plot with low vegetation coverage. However, under the condition of heavy rainfall intensity, there is no obvious difference in the beginning time of runoff. In addition, the higher the vegetation coverage is, the deeper the rainfall infiltration depth is.The results can provide reference for ecological construction carried out in wind erosion crisscross region with serious soil erosion.

  5. Nested Tracer Studies In Catchment Hydrology: Towards A Multiscale Understanding of Runoff Generation and Catchment Funtioning

    Science.gov (United States)

    Soulsby, C.; Rodgers, P.; Malcolm, I. A.; Dunn, S.

    Geochemical and isotopic tracers have been shown to have widespread utility in catch- ment hydrology in terms of identifying hydrological source areas and characterising residence time distributions. In many cases application of tracer techniques has pro- vided insights into catchment functioning that could not be obtained from hydromet- ric and/or modelling studies alone. This paper will show how the use of tracers has contributed to an evolving perceptual model of hydrological pathways and runoff gen- eration processes in catchments in the Scottish highlands. In particular the paper will focus on the different insights that are gained at three different scales of analysis; (a) nested sub-catchments within a mesoscale (ca. 200 square kilometers) experimen- tal catchment; (b) hillslope-riparian interactions and (c) stream bed fluxes. Nested hydrometric and hydrochemical monitoring within the mesoscale Feugh catchment identified three main hydrological response units: (i) plateau peatlands which gener- ated saturation overland flow in the catchment headwaters, (ii) steep valley hillslopes which drain from the plateaux into (iii) alluvial and drift aquifers in the valley bottoms. End Member Mixing Analysis (EMMA) in 8 nested sub-catchments indicated that that stream water tracer concentrations can be modelled in terms of 2 dominant runoff pro- cesses; overland flow from the peat and groundwater from the drift aquifers. Ground- water contributions generally increased with catchment size, though this was moder- ated by the characteristics of individual sub-basins, with drift cover being particularly important. Hillslope riparian interactions were also examined using tracers, hydromet- ric data and a semi-distributed hydrological model. This revealed that in the glaciated, drift covered terrain of the Scottish highlands, extensive valley bottom aquifers effec- tively de-couple hillslope waters from the river channel. Thus, riparian groundwater appears to significantly

  6. Assimilating satellite soil moisture into rainfall-runoff modelling: towards a systematic study

    Science.gov (United States)

    Massari, Christian; Tarpanelli, Angelica; Brocca, Luca; Moramarco, Tommaso

    2015-04-01

    Soil moisture is the main factor for the repartition of the mass and energy fluxes between the land surface and the atmosphere thus playing a fundamental role in the hydrological cycle. Indeed, soil moisture represents the initial condition of rainfall-runoff modelling that determines the flood response of a catchment. Different initial soil moisture conditions can discriminate between catastrophic and minor effects of a given rainfall event. Therefore, improving the estimation of initial soil moisture conditions will reduce uncertainties in early warning flood forecasting models addressing the mitigation of flood hazard. In recent years, satellite soil moisture products have become available with fine spatial-temporal resolution and a good accuracy. Therefore, a number of studies have been published in which the impact of the assimilation of satellite soil moisture data into rainfall-runoff modelling is investigated. Unfortunately, data assimilation involves a series of assumptions and choices that significantly affect the final result. Given a satellite soil moisture observation, a rainfall-runoff model and a data assimilation technique, an improvement or a deterioration of discharge predictions can be obtained depending on the choices made in the data assimilation procedure. Consequently, large discrepancies have been obtained in the studies published so far likely due to the differences in the implementation of the data assimilation technique. On this basis, a comprehensive and robust procedure for the assimilation of satellite soil moisture data into rainfall-runoff modelling is developed here and applied to six subcatchment of the Upper Tiber River Basin for which high-quality hydrometeorological hourly observations are available in the period 1989-2013. The satellite soil moisture product used in this study is obtained from the Advanced SCATterometer (ASCAT) onboard Metop-A satellite and it is available since 2007. The MISDc ("Modello Idrologico Semi

  7. Importance of moisture determination in studies of infiltration and surface runoff for long periods

    Directory of Open Access Journals (Sweden)

    Fabian Fulginiti

    2011-08-01

    Full Text Available The determination of the natural soil moisture is essential to solve problems related to irrigation water requirements, environmental considerations, and determination of surplus water. For the determination of runoff one can adopt models that consider exclusively the infiltration as a loss or one could use computational models of infiltration to model the infiltrated water. Models based on the infiltration calculation consider well the interaction between infiltration - runoff processes and provide additional information on the phenomenon of infiltration which establishes the existing conditions of moisture in the soil before the occurrence of a new event (simulation for long periods. These models require solving Richards’s equation and for this purpose it is necessary to determine the relation between the soil moisture - suction and hydraulic conductivity - suction which require the determination of the hydraulic properties that can be obtained by measuring the water content by moisture profiles. The aim of this study was the verification of these moisture curves in loessic soils in the south of the city of Cordoba, Argentina. To do this, measurements were done and compared with results of infiltration models based on the determined hydraulic functions. The measurements were done using three probes installed at different depths. The results showed that the values obtained with NETRAIN adequately represent the behavior of wetting and drying conditions of the studied soil.The determination of these curves provided a basis for future studies that include the advancement of agricultural chemicals in the soil and its potential capacity to pollute groundwater, fundamental issue to define environmental management policies.

  8. The assessment of land use change impact on watersheds runoff using SWAT: case study of Urmia Lake in Iran

    Science.gov (United States)

    Jabbari, Anahita; Jarihani, Ben; Rezaie, Hossein

    2015-04-01

    Lake Urmia, long counted among the world's largest saltwater lakes, contains only 5% of the amount of water it did just 20 years ago. The decline is generally blamed on a combination of drought, increased water diversion for irrigated agriculture within the lake's watershed and land use mismanagement. It has been believed that land use changes in Lake Urmia basin is one of the most important factors in shrinkage of Urmia Lake in recent decades. Transforming the traditional agricultural practices (i.e., wheat) to the more water consuming practices (i.e., apple orchards) is one of the most important reasons increased agricultural water consumption in the watershed. In this study we assessed the effect of the land use changes of watershed in hydrological runoff processing in the Nazloo chai watershed, one of the most important river basins of the Urmia Lake basin. Actually the rapid and at the same time unreasonable transformations of land use in farm lands of Urmia lake sub basins, extremely has been raised the amount of blue water (surface or groundwater) consumption in watershed which leads to dramatic decrement of watershed runoff amounts. One of the most unfavorable consequences of land use change was changing the blue and green (rainwater insofar as it does not become runoff) water usage patterns in watershed, in addition to water use increment. The soil and water assessment tool (SWAT), one of the most important and reliable models which was used to model the rainfall runoff, has been used in current study. The land use maps were extracted from Landsat images archives for the most severe turning points in respect of land use change in the recent 30 years. After calibrating the model, several land use patterns of historical data were used in the model to produce the runoff. The results showed the strong relation between land use change and runoff reduction in the Lake Urmia basin.

  9. Characterization and environmental management of stormwater runoff from road-salt storage facilities.

    Science.gov (United States)

    2004-01-01

    The objectives of this study were to assess the quantity and quality of salt-contaminated water generated from stormwater runoff at VDOT's salt storage facilities and to evaluate management/treatment alternatives to reduce costs and better protect th...

  10. Alternative Education Completers: A Phenomenological Study

    Science.gov (United States)

    Murray, Becky L.; Holt, Carleton R.

    2014-01-01

    The purpose of this study was to explore the elements of the alternative education experience significant to successful completion of the program. This phenomenological paradigm provided the framework for all aspects of the qualitative study. Students, parents, administrators, and staff members of two alternative programs in the southeast Kansas…

  11. Alternative Middle School Models: An Exploratory Study

    Science.gov (United States)

    Duffield, Stacy Kay

    2018-01-01

    A Midwestern state allocated grant funding to encourage more accessible alternative programming at the middle level. Seventeen schools were approved for this grant and used the funds to supplement the operation of a new or existing program. This study provides policymakers and educators with an overview of the various types of alternative middle…

  12. Runoff and soil erosion plot-scale studies under natural rainfall: A meta-analysis of the Brazilian experience

    Science.gov (United States)

    Research to measure soil erosion rates in the United States from natural rainfall runoff plots began in the early 1900’s. In Brazil, the first experimental study at the plot-scale was conducted in the 1940’s; however, the monitoring process and the creation of new experimental field plots have not c...

  13. Reducing phosphorus runoff and leaching from poultry litter with alum: Twenty-year small plot and paired-watershed studies

    Science.gov (United States)

    Treating poultry litter with alum is a best management practice (BMP) for lowering ammonia (NH3) emissions and phosphorus (P) runoff losses. The objective of this study was to evaluate the long-term (20 year) effects of alum-treated and untreated poultry litter applications on P availability, leachi...

  14. GIS-based Approach to Estimate Surface Runoff in Small Catchments: A Case Study

    Directory of Open Access Journals (Sweden)

    Vojtek Matej

    2016-09-01

    Full Text Available The issue of surface runoff assessment is one of the important and relevant topics of hydrological as well as geographical research. The aim of the paper is therefore to estimate and assess surface runoff on the example of Vyčoma catchment which is located in the Western Slovakia. For this purpose, SCS runoff curve number method, modeling in GIS and remote sensing were used. An important task was the creation of a digital elevation model (DEM, which enters the surface runoff modeling and affects its accuracy. Great attention was paid to the spatial interpretation of land use categories applying aerial imagery from 2013 and hydrological soil groups as well as calculation of maximum daily rainfall with N-year return periods as partial tasks in estimating surface runoff. From the methodological point of view, the importance of the paper can be seen in the use of a simple GIS-based approach to assess the surface runoff conditions in a small catchment.

  15. Energy Conversion Alternatives Study (ECAS)

    Science.gov (United States)

    1977-01-01

    ECAS compared various advanced energy conversion systems that can use coal or coal-derived fuels for baseload electric power generation. It was conducted in two phases. Phase 1 consisted of parametric studies. From these results, 11 concepts were selected for further study in Phase 2. For each of the Phase 2 systems and a common set of ground rules, performance, cost, environmental intrusion, and natural resource requirements were estimated. In addition, the contractors defined the state of the associated technology, identified the advances required, prepared preliminary research and development plans, and assessed other factors that would affect the implementation of each type of powerplant. The systems studied in Phase 2 include steam systems with atmospheric- and pressurized-fluidized-bed boilers; combined cycle gas turbine/steam systems with integrated gasifiers or fired by a semiclean, coal derived fuel; a potassium/steam system with a pressurized-fluidized-bed boiler; a closed-cycle gas turbine/organic system with a high-temperature, atmospheric-fluidized-bed furnace; a direct-coal-fired, open- cycle magnetohydrodynamic/steam system; and a molten-carbonate fuel cell/steam system with an integrated gasifier. The sensitivity of the results to changes in the ground rules and the impact of uncertainties in capital cost estimates were also examined.

  16. Study of heavy metals transport by runoff and sediments from an abandoned mine: Alagoa, Portugal

    Science.gov (United States)

    Gerardo, R.; de Lima, J. L. M. P.; de Lima, M. I. P.

    2009-04-01

    Over time, several studies have been designed to understand heavy metals fate and its impact on the environment and on human health. However, only a few studies have focused on the transport of heavy metals in mining areas through the various hydrological processes such as runoff, infiltration, and subsurface flow. In particular, heavy rainfall events have a great impact on the dispersion of metals existing in the soil. This problem is often more serious in abandoned and inactive mining sites causing environmental problems. In Portugal, there are 175 identified abandoned mines that continuously threaten the environment through acid drainage waters that pollute the soil as well as surface and groundwater. An example is the abandoned mine of Alagoa, located near the village of Penacova (Centre of Portugal); in this site mining activities ceased about 30 years ago. The area is characterized by very steep slopes that are confining with a small stream; the mining excavation by-products were deposited on these slopes. We have selected this mine as a case study, aiming at understanding the transport mechanisms and dispersion of heavy metals and at contributing to the definition of the most appropriate mitigation measures for this area that is contaminated by heavy metals from the mine tailings. So far a total of 30 soil samples from 3 contaminated zones were collected and analysed for pH, texture and heavy metal content, using atomic absorption spectroscopy. Results indicate that the contents of Zn and Pb in the soil samples are in the range from 95-460 mg/kg and 67-239 mg/kg, respectively, which exceed the critical limit-values defined by the Portuguese legislation. These metals are dispersed downslope and downstream from the mine tailings by storm water. The next step of this work is to investigate the transport of heavy metals by runoff, by mobilization of sediments and by subsurface flow. Three spatial scales tests will be conducted: on the mine tailings, on the slope

  17. Hopewell Furnace NHS : alternative transportation study

    Science.gov (United States)

    2009-12-31

    This study assesses the potential for an alternative transportation system (ATS) at Hopewell Furnace National Historic Site (NHS). The Volpe Center investigated internal circulation and potential partnerships with local historic, cultural, and recrea...

  18. Simulation of Urban Rainfall-Runoff in Piedmont Cities: A Case Study in Jinan City, China

    Science.gov (United States)

    Chang, X.; Xu, Z.; Zhao, G.; Li, H.

    2017-12-01

    During the past decades, frequent flooding disasters in urban areas resulted in catastrophic impacts such as human life casualties and property damages especially in piedmont cities due to its specific topography. In this study, a piedmont urban flooding model was developed in the Huangtaiqiao catchment based on SWMM. The sub-catchments in this piedmont area were divided into mountainous area, plain area and main urban area according to the variations of underlying surface topography. The impact of different routing mode and channel roughness on simulation results was quantitatively analyzed under different types of scenarios, and genetic algorithm was used to optimize model parameters. Results show that the simulation is poor (with a mean Nash coefficient of 0.61) when using the traditional routing mode in SWMM model, which usually ignores terrain variance in piedmont area. However, when the difference of routing mode, percent routed and channel roughness are considered, the prediction precision of model were significantly increased (with a mean Nash coefficient of 0.86), indicating that the difference of surface topography significantly affects the simulation results in piedmont cities. The relevant results would provide the scientific basis and technical support for rainfall-runoff simulation, flood control and disaster alleviation in piedmont cities.

  19. Batch vs continuous-feeding operational mode for the removal of pesticides from agricultural run-off by microalgae systems: A laboratory scale study

    Energy Technology Data Exchange (ETDEWEB)

    Matamoros, Víctor, E-mail: victor.matamoros@idaea.csic.es; Rodríguez, Yolanda

    2016-05-15

    Highlights: • The effect of microalgae on the removal of pesticides has been evaluated. • Continuous feeding operational mode is more efficient for removing pesticides. • Microalgae increased the removal of some pesticides. • Pesticide TPs confirmed that biodegradation was relevant. - Abstract: Microalgae-based water treatment technologies have been used in recent years to treat different water effluents, but their effectiveness for removing pesticides from agricultural run-off has not yet been addressed. This paper assesses the effect of microalgae in pesticide removal, as well as the influence of different operation strategies (continuous vs batch feeding). The following pesticides were studied: mecoprop, atrazine, simazine, diazinone, alachlor, chlorfenvinphos, lindane, malathion, pentachlorobenzene, chlorpyrifos, endosulfan and clofibric acid (tracer). 2 L batch reactors and 5 L continuous reactors were spiked to 10 μg L{sup −1} of each pesticide. Additionally, three different hydraulic retention times (HRTs) were assessed (2, 4 and 8 days) in the continuous feeding reactors. The batch-feeding experiments demonstrated that the presence of microalgae increased the efficiency of lindane, alachlor and chlorpyrifos by 50%. The continuous feeding reactors had higher removal efficiencies than the batch reactors for pentachlorobenzene, chlorpyrifos and lindane. Whilst longer HRTs increased the technology’s effectiveness, a low HRT of 2 days was capable of removing malathion, pentachlorobenzene, chlorpyrifos, and endosulfan by up to 70%. This study suggests that microalgae-based treatment technologies can be an effective alternative for removing pesticides from agricultural run-off.

  20. Batch vs continuous-feeding operational mode for the removal of pesticides from agricultural run-off by microalgae systems: A laboratory scale study

    International Nuclear Information System (INIS)

    Matamoros, Víctor; Rodríguez, Yolanda

    2016-01-01

    Highlights: • The effect of microalgae on the removal of pesticides has been evaluated. • Continuous feeding operational mode is more efficient for removing pesticides. • Microalgae increased the removal of some pesticides. • Pesticide TPs confirmed that biodegradation was relevant. - Abstract: Microalgae-based water treatment technologies have been used in recent years to treat different water effluents, but their effectiveness for removing pesticides from agricultural run-off has not yet been addressed. This paper assesses the effect of microalgae in pesticide removal, as well as the influence of different operation strategies (continuous vs batch feeding). The following pesticides were studied: mecoprop, atrazine, simazine, diazinone, alachlor, chlorfenvinphos, lindane, malathion, pentachlorobenzene, chlorpyrifos, endosulfan and clofibric acid (tracer). 2 L batch reactors and 5 L continuous reactors were spiked to 10 μg L"−"1 of each pesticide. Additionally, three different hydraulic retention times (HRTs) were assessed (2, 4 and 8 days) in the continuous feeding reactors. The batch-feeding experiments demonstrated that the presence of microalgae increased the efficiency of lindane, alachlor and chlorpyrifos by 50%. The continuous feeding reactors had higher removal efficiencies than the batch reactors for pentachlorobenzene, chlorpyrifos and lindane. Whilst longer HRTs increased the technology’s effectiveness, a low HRT of 2 days was capable of removing malathion, pentachlorobenzene, chlorpyrifos, and endosulfan by up to 70%. This study suggests that microalgae-based treatment technologies can be an effective alternative for removing pesticides from agricultural run-off.

  1. Urban runoff and combined sewer overflow. [Wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Moffa, P.E. (Calocerinos and Spina, Liverpool, NY); Freedman, S.D.; Owens, E.M.; Field, R.; Cibik, C.

    1982-06-01

    The control, treatment and management of urban runoff and sewer overflow are reviewed. Simplified modeling and monitoring techniques are used to characterize urban runoff and to assess control alternatives. (KRM)

  2. Climate change impact on the river runoff: regional study for the Central Asian Region

    International Nuclear Information System (INIS)

    Agaitseva, Natalya

    2004-01-01

    The water resources of the Aral Sea Basin are jointly used by the Central Asian states. The river flow is concentrated in the two largest transboundary rivers: the Amudarya and Syrdarya Rivers, which run down from the mountains to the plains, cross the deserts and flow into the Aral Sea. Uzbekistan is the major water consumer in the Aral Sea Basin. In accordance with interstate agreements, on average 43-52 km 2 of water per year as allotted for use by Uzbekistan from the boundary rivers. About 90% of river flow is formed beyond Uzbekistan boundaries. Under current conditions, water resource shortages in Uzbekistan, even a small but stable reduction of these resources presents a drastic problem. The degree of impact of possible climate changes on the regime of mountain rivers of the Central Asia can be evaluated by sufficiently reliable mathematical models of the runoff formation in mountains. The basic mathematical model describes a complete cycle of the runoff formation, reflecting the main factors and processes: precipitation, dynamics of a snow cover, evaporation, contribution of melting and rain water to the catchment, glacial runoff, runoff transformation and losses in basin. The model complex consists of the model Of snow cover formation in the mountains basin, model of glacial runoff and model of snow melt and rainfall water inflow transformation in runoff. Model calculations of snow reserves in the mountains under different climatic scenarios have demonstrated their gradual decrease due to growing aridity of the climate. Contribution of the snow is expected to decrease by 15-30%1 especially for rivers, which are snow-fed. At present, the annual glacial runoff of the rivers of the Syrdarya River basin amounts to 8-15%. Under different prognoses,,, increase in this flow of up to 20% is expected. Contribution of glacial runoff to the rivers of the Amudarya River basin might grow 32-39% under the most 'severe' climatic scenarios. During the cropping season, an

  3. Experimental study and simulation of phosphorus purification effects of bioretention systems on urban surface runoff.

    Directory of Open Access Journals (Sweden)

    Jiake Li

    Full Text Available Excessive phosphorus (P contributes to eutrophication by degrading water quality and limiting human use of water resources. Identifying economic and convenient methods to control soluble reactive phosphorus (SRP pollution in urban runoff is the key point of rainwater management strategies. Through three series of different tests involving influencing factors, continuous operation and intermittent operation, this study explored the purification effects of bioretention tanks under different experimental conditions, it included nine intermittent tests, single field continuous test with three groups of different fillers (Fly ash mixed with sand, Blast furnace slag, and Soil, and eight intermittent tests with single filler (Blast furnace slag mixed with sand. Among the three filler combinations studied, the filler with fly ash mixed with sand achieved the best pollution reduction efficiency. The setting of the submerged zone exerted minimal influence on the P removal of the three filler combinations. An extension of the dry period slightly promoted the P purification effect. The combination of fly ash mixed with sand demonstrated a positive purification effect on SRP during short- or long-term simulated rainfall duration. Blast furnace slag also presented a positive purification effect in the short term, although its continuous purification effect on SRP was poor in the long term. The purification abilities of soil in the short and long terms were weak. Under intermittent operations across different seasons, SRP removal was unstable, and effluent concentration processes were different. The purification effect of the bioretention system on SRP was predicted through partial least squares regression (PLS modeling analysis. The event mean concentration removal of SRP was positively related to the adsorption capacity of filler and rainfall interval time and negatively related to submerged zones, influent concentration and volume.

  4. Case study: design, operation, maintenance and water quality management of sustainable storm water ponds for roof runoff.

    Science.gov (United States)

    Scholz, Miklas

    2004-12-01

    The purpose of this case study was to optimise design, operation and maintenance guidelines, and to assess the water treatment potential of a storm water pond system after 15 months of operation. The system was based on a combined silt trap, attenuation pond and vegetated infiltration basin. This combination was used as the basis for construction of a roof water runoff system from a single domestic property. United Kingdom Building Research Establishment and Construction Industry Research and Information Association, and German Association for Water, Wastewater and Waste design guidelines were tested. These design guidelines failed because they did not consider local conditions. The infiltration function for the infiltration basin was logarithmic. Algal control techniques were successfully applied, and treatment of rainwater runoff from roofs was found to be largely unnecessary for recycling (e.g., watering plants). However, seasonal and diurnal variations of biochemical oxygen demand, dissolved oxygen and pH were recorded.

  5. Runoff of particle bound pollutants from urban impervious surfaces studied by analysis of sediments from stormwater traps

    International Nuclear Information System (INIS)

    Jartun, Morten; Ottesen, Rolf Tore; Steinnes, Eiliv; Volden, Tore

    2008-01-01

    Runoff sediments from 68 small stormwater traps around the harbor of urban Bergen, Norway, were sampled and the concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, and total organic carbon (TOC) were determined in addition to grain size. Our study provides empirical data from a large area in the interface between the urban and marine environment, studying the active transport of pollutants from land-based sources. The results of the analyses clearly demonstrate the importance of the urban environment representing a variety of contamination sources, and that stormwater runoff is an important dispersion mechanism of toxic pollutants. The concentrations of different pollutants in urban runoff sediments show that there are several active pollution sources supplying the sewage systems with PCBs, PAHs and heavy metals such as lead (Pb), zinc (Zn) and cadmium (Cd). The concentration of PCB 7 in the urban runoff sediments ranged between 16 , the concentration range was < 0.2-80 mg/kg, whereas the concentration ranges of Pb, Zn and Cd were 9-675, 51.3-4670 and 0.02-11.1 mg/kg respectively. Grain size distribution in 21 selected samples varied from a median particle diameter of 13 to 646 μm. However, several samples had very fine-grained particles even up to the 90 percentile of the samples, making them available for stormwater dispersion in suspended form. The sampling approach proposed in this paper will provide environmental authorities with a useful tool to examine ongoing urban contamination of harbors and similar recipients

  6. Comparative assessment of herbicide and fungicide runoff risk: a case study for peanut production in the Southern Atlantic Coastal Plain (USA).

    Science.gov (United States)

    Potter, Thomas L; Bosch, David D; Strickland, Timothy C

    2014-08-15

    Peanut (Arachis hypogaea) is produced intensively in the southern Atlantic Coastal Plain of the eastern USA. To effectively protect the region's water quality data are needed which quantify runoff of pesticides used to protect these crops. Fungicides are used intensively yet there is little published data which describe their potential for loss in surface runoff. This study compared runoff of a fungicide, tebuconazole (α-[2-(4-chlorophenyl)ethyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol), and an herbicide, metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide) from 0.2 ha fields in strip (ST), a commonly used conservation-tillage practice, and conventional tillage (CT) near Tifton, GA (USA). Following their first application, metolachlor and tebuconazole were detected at high frequency in runoff. Concentrations and their annual losses increased with application frequency and runoff event timing and frequency with respect to applications, and when fields were positioned at the top of the slope and CT was practiced. Runoff one day after treatment (DAT) contributed to high tebuconazole runoff loss, up to 9.8% of the amount applied on an annual basis. In all cases, metolachlor loss was more than 10 times less even though total application was 45% higher. This was linked to the fact that the one metolachlor application to each crop was in May, one of the region's driest months. In sum, studies showed that fungicide runoff rates may be relatively high and emphasize the need to focus on these products in future studies on peanut and other crops. The study also showed that peanut farmers should be encouraged to use conservation tillage practices like ST which can substantially reduce pesticide runoff. Published by Elsevier B.V.

  7. The use of simulated rainfall to study the discharge process and the influence factors of urban surface runoff pollution loads.

    Science.gov (United States)

    Qinqin, Li; Qiao, Chen; Jiancai, Deng; Weiping, Hu

    2015-01-01

    An understanding of the characteristics of pollutants on impervious surfaces is essential to estimate pollution loads and to design methods to minimize the impacts of pollutants on the environment. In this study, simulated rainfall equipment was constructed to investigate the pollutant discharge process and the influence factors of urban surface runoff (USR). The results indicated that concentrations of total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) appeared to be higher in the early period and then decreased gradually with rainfall duration until finally stabilized. The capacity and particle size of surface dust, rainfall intensity and urban surface slopes affected runoff pollution loads to a variable extent. The loads of TP, TN and COD showed a positive relationship with the surface dust capacity, whereas the maximum TSS load appeared when the surface dust was 0.0317 g·cm⁻². Smaller particle sizes (pollution carrying capacity of runoff, leading to higher pollution loads. Knowledge of the influence factors could assist in the management of USR pollution loads.

  8. Can green roof act as a sink for contaminants? A methodological study to evaluate runoff quality from green roofs.

    Science.gov (United States)

    Vijayaraghavan, K; Joshi, Umid Man

    2014-11-01

    The present study examines whether green roofs act as a sink or source of contaminants based on various physico-chemical parameters (pH, conductivity and total dissolved solids) and metals (Na, K, Ca, Mg, Al, Fe, Cr, Cu, Ni, Zn, Cd and Pb). The performance of green roof substrate prepared using perlite, vermiculite, sand, crushed brick, and coco-peat, was compared with local garden soil based on improvement of runoff quality. Portulaca grandiflora was used as green roof vegetation. Four different green roof configurations, with vegetated and non-vegetated systems, were examined for several artificial rain events (un-spiked and metal-spiked). In general, the vegetated green roof assemblies generated better-quality runoff with less conductivity and total metal ion concentration compared to un-vegetated assemblies. Of the different green roof configurations examined, P. grandiflora planted on green roof substrate acted as sink for various metals and showed the potential to generate better runoff. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Runoff and sediment transport in the arid regions of Argentina and India - a case study in comparative hydrology

    NARCIS (Netherlands)

    Sharma, K.D.; Menenti, M.; Huygen, J.; Fernandez, P.C.; Vich, A.

    1996-01-01

    The arid zones of Argentina and India have been compared. In both regions run-off is often generated by the Hortonian infiltration surplus overland flow, and run-off response to precipitation input tends to be rapid. The sediment transport is governedby the transport capacity of run-off rather than

  10. Runoff characteristics and non-point source pollution analysis in the Taihu Lake Basin: a case study of the town of Xueyan, China.

    Science.gov (United States)

    Zhu, Q D; Sun, J H; Hua, G F; Wang, J H; Wang, H

    2015-10-01

    Non-point source pollution is a significant environmental issue in small watersheds in China. To study the effects of rainfall on pollutants transported by runoff, rainfall was monitored in Xueyan town in the Taihu Lake Basin (TLB) for over 12 consecutive months. The concentrations of different forms of nitrogen (N) and phosphorus (P), and chemical oxygen demand, were monitored in runoff and river water across different land use types. The results indicated that pollutant loads were highly variable. Most N losses due to runoff were found around industrial areas (printing factories), while residential areas exhibited the lowest nitrogen losses through runoff. Nitrate nitrogen (NO3-N) and ammonia nitrogen (NH4-N) were the dominant forms of soluble N around printing factories and hotels, respectively. The levels of N in river water were stable prior to the generation of runoff from a rainfall event, after which they were positively correlated to rainfall intensity. In addition, three sites with different areas were selected for a case study to analyze trends in pollutant levels during two rainfall events, using the AnnAGNPS model. The modeled results generally agreed with the observed data, which suggests that AnnAGNPS can be used successfully for modeling runoff nutrient loading in this region. The conclusions of this study provide important information on controlling non-point source pollution in TLB.

  11. Assateague Island National Seashore alternative transportation systems planning study and business plan for alternative transportation

    Science.gov (United States)

    2012-08-31

    The purpose of this study was to (1) study the potential expansion of existing alternative transportation systems (bicycle facilities) and development of new alternative transportation systems in and around the Maryland District of Assateague Island ...

  12. Export Mechanisms of Persistent Toxic Substances (PTSs) in Urban Land Uses during Rainfall-Runoff Events: Experimental and Modeling Studies

    Science.gov (United States)

    Zheng, Y.; Luo, X.; Lin, Z.

    2016-12-01

    The urban environment has a variety of Persistent Toxic Substances (PTS), such as Polycyclic Aromatic Hydrocarbons (PAHs) and mercury. Soil in pervious lands and dust deposited on impervious surfaces are two major sinks of PTSs in urbanized areas, which could contribute significant nonpoint source loadings of PTSs to adjacent waterbodies during rainfall-runoff events and therefore jeopardize aquatic ecosystems. However, PTSs have been much less understood regarding their export mechanisms in urban land uses, and efforts to model nonpoint source pollution processes of PTSs have been rare. We designed and performed in-lab rainfall-runoff simulation experiments to investigate transport of PAHs and mercury by runoff from urban soils. Organic petrology analysis (OPA) techniques were introduced to analyze the soil and sediment compositions. Our study revealed the limitation of the classic enrichment theory which attributes enrichment of pollutants in eroded sediment solely to the sediment's particle size distribution and adopts simple relationships between enrichment ratio and sediment flux. We found that carbonaceous materials (CMs) in soil are the direct and major sorbents for PAHs and mercury, and highly different in content, mobility and adsorption capacity for the PTSs. Anthropogenic CMs like black carbon components largely control the transport of soil PAHs, while humic substances have a dominant influence on the transport of soil mercury. A model was further developed to estimate the enrichment ratio of PAHs, which innovatively applies the fugacity concept.We also conducted field studies on export of PAHs by runoff from urban roads. A variable time-step model was developed to simulate the continuous cycles of PAH buildup and washoff on urban roads. The dependence of the pollution level on antecedent weather conditions was investigated and embodied in the model. The applicability of this approach and its value to environmental management was demonstrated by a case

  13. Field study plan for alternate barriers

    International Nuclear Information System (INIS)

    Freeman, H.D.; Gee, G.W.; Relyea, J.F.

    1989-05-01

    Pacific Northwest Laboratory (PNL) is providing technical assistance in selecting, designing, evaluating, and demonstrating protective barriers. As part of this technical assistance effort, asphalt, clay, and chemical grout will be evaluated for use as alternate barriers. The purpose of the subsurface layer is to reduce the likelihood that extreme events (i.e., 100-year maximum storms, etc.) will cause significant drainage through the barrier. The tests on alternate barriers will include laboratory and field analysis of the subsurface layer performance. This field test plan outlines the activities required to test and design subsurface moisture barriers. The test plan covers activities completed in FY 1988 and planned through FY 1992 and includes a field-scale test of one or more of the alternate barriers to demonstrate full-scale application techniques and to provide performance data on a larger scale. Tests on asphalt, clay, and chemical grout were initiated in FY 1988 in small (30.5 cm diameter) tube-layer lysimeters. The parameters used for testing the materials were different for each one. The tests had to take into account the differences in material characteristics and response to change in conditions, as well as information provided by previous studies. 33 refs., 8 figs., 1 tab

  14. A field study to evaluate the impact of different factors on the nutrient pollutant concentrations in green roof runoff.

    Science.gov (United States)

    Wang, Xiaochen; Zhao, Xinhua; Peng, Chenrui; Zhang, Xinbo; Wang, Jianghai

    2013-01-01

    The objectives of this study are to investigate the impact of different factors on the nutrient pollutant concentrations in green roof runoff and to provide reference data for the engineering design of dual substrate layer green roofs. The data were collected from eight different trays under three kinds of artificial rains. The results showed that except for total phosphorus, dual substrate layer green roofs behaved as a sink for most of the nutrient pollutants (significant at p green roof and the depth of the adsorption substrates. Compared with the influence of the substrates, the influence of the plant density and drainage systems was small.

  15. The study of contamination of discharged runoff from surface water disposal channels of Bushehr city in 2012-2013

    Directory of Open Access Journals (Sweden)

    Vaheid Noroozi-Karbasdehi

    2016-09-01

    Full Text Available Background: In coastal cities, wastewater discharge into the sea is one of the options for sewage disposal that in case of non-compliance with health standards  in wastewater disposal will be led to the spread of infection and disease. On the other hand, water resources preservation and using them efficiently are the principles of sustainable development of each country. This study was aimed to investigate the contamination of discharged runoff from the surface water disposal channels of Bushehr city in 2012 - 13. Materials and Methods: In this study, Sampling was conducted by composite sampling method from output of the five main surface water disposal channels leading to the Persian Gulf located in the coastal region of Bushehr city during two seasons including wet (winter and dry (summer in 2012- 13. Then, experimental tests of BOD5, total coliform and fecal coliform were done on any of the 96 samples according to the standard method. Results: Analysis of the data showed that the BOD5, total coliform and fecal coliform of effluent runoff of the channels were more than the national standard output of disposal wastewaters into the surface waters, and the highest and lowest amount of BOD5 which obtained were 160 mg/L and 28 mg/L, respectively. Conclusion: considering the fact that discharged runoff from surface water disposal channels link from shoreline to sea in close distance and they often are as natural swimming sites and even fishing sites of Bushehr city, and also according to high level of organic and bacterial load of these channels, it is urgently required to be considered by the authorities.

  16. Effects of low-impact-development (LID) practices on streamflow, runoff quantity, and runoff quality in the Ipswich River Basin, Massachusetts-A Summary of field and modeling studies

    Science.gov (United States)

    Zimmerman, Marc J.; Waldron, Marcus C.; Barbaro, Jeffrey R.; Sorenson, Jason R.

    2010-01-01

    Low-impact-development (LID) approaches are intended to create, retain, or restore natural hydrologic and water-quality conditions that may be affected by human alterations. Wide-scale implementation of LID techniques may offer the possibility of improving conditions in river basins, such as the Ipswich River Basin in Massachusetts, that have run dry during the summer because of groundwater withdrawals and drought. From 2005 to 2008, the U.S. Geological Survey, in a cooperative funding agreement with the Massachusetts Department of Conservation and Recreation, monitored small-scale installations of LID enhancements designed to diminish the effects of storm runoff on the quantity and quality of surface water and groundwater. Funding for the studies also was contributed by the U.S. Environmental Protection Agency's Targeted Watersheds Grant Program through a financial assistance agreement with Massachusetts Department of Conservation and Recreation. The monitoring studies examined the effects of * replacing an impervious parking-lot surface with a porous surface on groundwater quality, * installing rain gardens and porous pavement in a neighborhood of 3 acres on the quantity and quality of stormwater runoff, and * installing a 3,000-ft2 (square-foot) green roof on the quantity and quality of rainfall-generated roof runoff. In addition to these small-scale installations, the U.S. Geological Survey's Ipswich River Basin model was used to simulate the basin-wide effects on streamflow of several changes: broad-scale implementation of LID techniques, reduced water-supply withdrawals, and water-conservation measures. Water-supply and conservation scenarios for application in model simulations were developed with the assistance of two technical advisory committees that included representatives of State agencies responsible for water resources, the U.S. Environmental Protection Agency, the U.S. Geological Survey, water suppliers, and non-governmental organizations. From June

  17. Characterizing drought in terms of changes in the precipitation-runoff relationship: a case study of the Loess Plateau, China

    Science.gov (United States)

    Zhang, Yuan; Feng, Xiaoming; Wang, Xiaofeng; Fu, Bojie

    2018-03-01

    The frequency and intensity of drought are increasing dramatically with global warming. However, few studies have characterized drought in terms of its impacts on ecosystem services, the mechanisms through which ecosystems support life. As a result, little is known about the implications of increased drought for resource management. This case study characterizes drought by linking climate anomalies with changes in the precipitation-runoff relationship (PRR) on the Loess Plateau of China, a water-limited region where ongoing revegetation makes drought a major concern. We analyzed drought events with drought durations ≥ 5 years and mean annual precipitation anomaly (PA) values ≤ -5 % during drought periods. The results show that continuous precipitation shifts are able to change the water balance of watersheds in water-limited areas, and multi-year drought events cause the PRR to change with a significantly decreasing trend (p runoff ratio decreased from 10 to 6.8 % during 1991-1999. The joint probability and return period gradually increase with increasing of drought duration and severity. The ecosystem service of water yield is easily affected by drought events with durations equal to or greater than 6 years and drought severity values equal to or greater than 0.55 (precipitation ≤ 212 mm). At the same time, multi-year drought events also lead to significant changes in the leaf area index (LAI). Such studies are essential for ecosystem management in water-limited areas.

  18. Rooftop runoff as a source of contamination: a review.

    Science.gov (United States)

    Lye, Dennis J

    2009-10-15

    Scientific reports concerning chemical and microbiological contaminant levels of rainwater runoff from rooftop collection in both urban and rural areas are reviewed. This alternative source of water has been documented to often contain substantial amounts of contaminants. Studies describing levels of heavy metal contamination specific to runoff from rooftop catchment areas containing exposed metal surfaces are discussed. Depending upon the intended use, scientific evidence is also accumulating that various treatments and disinfections will be required prior to release of roof-runoff water either into surface waters or for more direct consumer usage. For microbial contamination, current proposed standards and guidelines regarding this type of water source are shown to vary widely worldwide. Scientific literature reveals a lack of clarity regarding water quality guidelines and health related standards for certain types of rooftop runoff. Studies suggests that rainwater collection systems which are properly designed, maintained, and treated may provide a valuable supplement to existing water supplies by reducing demand on community water supplies/infrastructure costs, enhancing effective management of storm water runoff, and increasing restoration of underground reservoirs through controlled infiltration.

  19. Soils - Potential Runoff

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital spatial data set provides information on the spatial distribution of potential runoff-contributing areas in Kansas. Potential runoff-contributing areas...

  20. NRC inspection alternatives. A study report

    International Nuclear Information System (INIS)

    Conver, S.K.; Legasey, E.E.; LeDoux, J.C.; Rehfuss, C.

    1977-04-01

    IE's efforts in pursuing various resident inspection concepts are consistent with the stated interests of the new Administration in improving federal oversight of the nuclear industry. Four alternative resident inspection concepts are described and evaluated vis-a-vis the current program. The concept of full-time onsite inspectors as a preferred alternative is discussed. The tasks necessary to implement this preferred alternative are described

  1. Estimating Subcatchment Runoff Coefficients using Weather Radar and a Downstream Runoff Sensor

    DEFF Research Database (Denmark)

    Ahm, Malte; Thorndahl, Søren Liedtke; Rasmussen, Michael R.

    2013-01-01

    This paper presents a method for estimating runoff coefficients of urban drainage subcatchments based on a combination of high resolution weather radar data and flow measurements from a downstream runoff sensor. By utilising the spatial variability of the precipitation it is possible to estimate...... the runoff coefficients of the separate subcatchments. The method is demonstrated through a case study of an urban drainage catchment (678 ha) located in the city of Aarhus, Denmark. The study has proven that it is possible to use corresponding measurements of the relative rainfall distribution over...... the catchment and downstream runoff measurements to identify the runoff coefficients at subcatchment level....

  2. Estimating subcatchment runoff coefficients using weather radar and a downstream runoff sensor.

    Science.gov (United States)

    Ahm, Malte; Thorndahl, Søren; Rasmussen, Michael R; Bassø, Lene

    2013-01-01

    This paper presents a method for estimating runoff coefficients of urban drainage subcatchments based on a combination of high resolution weather radar data and flow measurements from a downstream runoff sensor. By utilising the spatial variability of the precipitation it is possible to estimate the runoff coefficients of the separate subcatchments. The method is demonstrated through a case study of an urban drainage catchment (678 ha) located in the city of Aarhus, Denmark. The study has proven that it is possible to use corresponding measurements of the relative rainfall distribution over the catchment and downstream runoff measurements to identify the runoff coefficients at subcatchment level.

  3. Autoignition Studies of Diesel Alternative Biofuels

    Science.gov (United States)

    Wang, Weijing

    The autoignition of biofuel compounds that offer potential as diesel fuel alternatives was studied under high-pressure engine-like conditions using the shock tube technique. Ignition delay times were determined in reflected shock experiments using measured pressure and electronically-excited OH emission. Measurements were made at conditions ranging from 650 to 1350 K, pressures from 6 to 50 atm, and for fuel/air/diluent mixtures at equivalence ratios from 0.5 to 2. The wide range of temperatures examined provides observation of autoignition in three reactivity regimes, including the negative temperature coefficient (NTC) regime which is characteristic of fuels containing alkyl functionalities. Compounds studied include biodiesel-related compounds and real biodiesel fuels, dimethyl ether, and 3-methylheptane which is representative of compounds found in synthetic diesel fuels produced using the Fischer-Tropsch and hydrotreatment processes. Biodiesel compounds studied include biodiesel surrogates, methyl decanoate, methyl-5-decenoate, and methyl-9-decenoate; compounds found in large quantities in biodiesels, methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate; and soy-based and animal fat based methyl ester biodiesels. Comparison of biodiesel compounds illustrates the influence of molecular structure (e.g., chain length, double bonds, and ester functionality) on reactivity. For methyl decanoate, the effect of high pressure exhaust gas recirculation (EGR) conditions relevant to internal combustion engines was also determined. Results showed that the first-order influence of EGR by displacing fuel and O2 to decrease radical branching. Measurements were compared to kinetic modeling results from models available in the literature providing varying degrees of model validation. Reaction flux analyses were also carried out to further examine the kinetic differences in different temperature regimes for fuel compounds. For example, reaction flux analyses

  4. Characterizing drought in terms of changes in the precipitation–runoff relationship: a case study of the Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    Y. Zhang

    2018-03-01

    Full Text Available The frequency and intensity of drought are increasing dramatically with global warming. However, few studies have characterized drought in terms of its impacts on ecosystem services, the mechanisms through which ecosystems support life. As a result, little is known about the implications of increased drought for resource management. This case study characterizes drought by linking climate anomalies with changes in the precipitation–runoff relationship (PRR on the Loess Plateau of China, a water-limited region where ongoing revegetation makes drought a major concern. We analyzed drought events with drought durations  ≥  5 years and mean annual precipitation anomaly (PA values  ≤  −5 % during drought periods. The results show that continuous precipitation shifts are able to change the water balance of watersheds in water-limited areas, and multi-year drought events cause the PRR to change with a significantly decreasing trend (p < 0.05 compared to other historical records. For the Loess Plateau as a whole, the average runoff ratio decreased from 10 to 6.8  % during 1991–1999. The joint probability and return period gradually increase with increasing of drought duration and severity. The ecosystem service of water yield is easily affected by drought events with durations equal to or greater than 6 years and drought severity values equal to or greater than 0.55 (precipitation  ≤  212 mm. At the same time, multi-year drought events also lead to significant changes in the leaf area index (LAI. Such studies are essential for ecosystem management in water-limited areas.

  5. Impact of Practice Change on Runoff Water Quality and Vegetable Yield—An On-Farm Case Study

    Directory of Open Access Journals (Sweden)

    Gunasekhar Nachimuthu

    2017-03-01

    Full Text Available Intensive agricultural practices in farming systems in eastern Australia have been identified as a contributor to the poor runoff water quality entering the Great Barrier Reef (GBR. A field investigation was carried out to measure the off-farm water quality and productivity in a coastal farming system in northeastern Australia. Two vegetable crops (capsicum and zucchini were grown in summer 2010–2011 and winter 2011 respectively using four different management practices (Conventional—plastic mulch, bare inter-row conventional tillage and commercial fertilizer inputs; Improved—improved practice with plastic mulch, inter-row vegetative mulch, zonal tillage and reduced fertilizer rates; Trash mulch—improved practice with cane-trash or forage-sorghum mulch with reduced fertilizer rates, minimum or zero tillage; and Vegetable only—improved practice with Rhodes grass or forage-sorghum mulch, minimum or zero tillage, reduced fertilizer rates. Results suggest improved and trash mulch systems reduced sediment and nutrient loads by at least 50% compared to conventional systems. The residual nitrate nitrogen in soil accumulated at the end-of-break crop cycle was lost by deep drainage before the subsequent sugarcane crop could utilize it. These results suggest that future research into establishing the linkages between deep drainage, groundwater quality and lateral movement into adjacent streams is needed. The improvement in runoff water quality was accompanied by yield reductions of up to 55% in capsicum and 57% in zucchini under trash mulch systems, suggesting a commercially unacceptable trade-off between water quality and productivity for a practice change. The current study has shown that variations around improved practice (modified nutrient application strategies under plastic mulch, but with an inter-space mulch to minimize runoff and sediment loss may be the most practical solution to improve water quality and maintain productivity

  6. Study on Runoff Debit in the Catchment Area of Waduk Gajah Mungkur Wonogiri

    Directory of Open Access Journals (Sweden)

    Alif Noor Anna

    2004-01-01

    Water resource is one of natural resources, that is very vital. It needed to be used and to be kept throughly. For those purposes need good and directed plan, in which one of the basic component of it plan have to be supported by available a complete hydrological data and it analysis. One of hydrological data analysis is to estimate runoff of catchement area, which can be used for planning the hydrologi construction. This research aim: 1 to calculate the run off discharge by thornwaite Mather Method, monthly, annualy, and the average on the catchment through a sample of Keduang, Temon, Alang, and Wuryantoro areas; 2 to analyze the difference of the run off discharge (at no. 1 by observation resulted from trend analysis. Based on the calculation, it appears, thornwaite-mather method showed that high discharge (moreover limit 0 in dry month. From the research result, it appears, that calculation discharge graphic had lower differentation than observation discharge graphic. From sample of catchment areas that have been investigated, from the highest to the lowest deviation was Wuryantoro catchment area (78,8%, Temon catchment area (47,38%, Alang catchment area (46,45%, and Keduang catchment area (24,98% respectively. The condition like above caused by intervation of man. Not only did he influence vegetatively, but he influenced technically as well. From these conservation, technical conservation (flood and construction and reservoir was the highest influence to run off discharge calculation. The run off discharge that was calculated by thornthwite-Mather Method based on air temperate, rainy, altitude, and water holding capacity only, but groundwater supply didn’t be calculated.

  7. [Effect of antecedent dry weather period on urban storm runoff pollution load].

    Science.gov (United States)

    Li, Li-qing; Yin, Cheng-qing; Kong, Ling-li; He, Qing-ci

    2007-10-01

    Twelve storm events were surveyed at Shilipu catchment in Wuhan City through three-year monitoring regime. The flow discharges, total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) in runoff were measured to study the mechanism of urban stormwater runoff pollution. The relationship between the event pollution load and the antecedent dry weather period was identified to discuss the influence of the urban surface sanitation management, operation of sewer pipe maintenance and rainfall characteristics on the urban stormwater runoff pollution. It was found that the antecedent dry weather period and runoff amount were the important determining factors in the generation of urban stormwater runoff pollution. The event pollution load was positively correlated to the antecedent dry weather period between two rainfall events (R2 = 0.95, p pollution loads. The best regression equation to estimate pollution load for storm events was developed based on the antecedent dry weather period and runoff depth. Source control including improving urban street sweeping activities and operation of sewer pipe maintenance should be made to reduce the amount of available pollutant over the dry days. It is important alternative to control urban stormwater runoff pollution for Hanyang District.

  8. Ironmaking Process Alternative Screening Study, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Lockwood Greene, . .

    2005-01-06

    Iron in the United States is largely produced from iron ore mined in the United States or imported from Canada or South America. The iron ore is typically smelted in Blast Furnaces that use primarily iron ore, iron concentrate pellets metallurgical coke, limestone and lime as the raw materials. Under current operating scenarios, the iron produced from these Blast Furnaces is relatively inexpensive as compared to current alternative iron sources, e.g. direct iron reduction, imported pig iron, etc. The primary problem the Blast Furnace Ironmaking approach is that many of these Blast furnaces are relatively small, as compared to the newer, larger Blast Furnaces; thus are relatively costly and inefficient to operate. An additional problem is also that supplies of high-grade metallurgical grade coke are becoming increasingly in short supply and costs are also increasing. In part this is due to the short supply and costs of high-grade metallurgical coals, but also this is due to the increasing necessity for environmental controls for coke production. After year 2003 new regulations for coke product environmental requirement will likely be promulgated. It is likely that this also will either increase the cost of high-quality coke production or will reduce the available domestic U.S. supply. Therefore, iron production in the United States utilizing the current, predominant Blast Furnace process will be more costly and would likely be curtailed due to a coke shortage. Therefore, there is a significant need to develop or extend the economic viability of Alternate Ironmaking Processes to at least partially replace current and declining blast furnace iron sources and to provide incentives for new capacity expansion. The primary conclusions of this comparative Study of Alternative Ironmaking Process scenarios are: (1) The processes with the best combined economics (CAPEX and OPEX impacts in the I.R.R. calculation) can be grouped into those Fine Ore based processes with no scrap

  9. Runoff Effect Evaluation of LID through SWMM in Typical Mountainous, Low-Lying Urban Areas: A Case Study in China

    Directory of Open Access Journals (Sweden)

    Qinghua Luan

    2017-06-01

    Full Text Available Urban flooding occurs frequently in many regions of China. To reduce the losses caused by urban flooding, sponge city (SPC and low-impact development (LID have been carried out in many Chinese cities. However, urban flooding is influenced by various factors, such as climate, land cover characteristics and nearby river networks, so it is necessary to evaluate the effectiveness of LID measures. In this study, the Storm Water Management Model (SWMM was adopted to simulate historical urban storm processes in the mountainous Fragrance Hills region of Beijing, China. Subsequently, numerical simulations were performed to evaluate how various LID measures (concave greenbelt, permeable pavement, bio-retention, vegetative swales, and comprehensive measures influenced urban runoff reduction. The results showed that the LID measures are effective in controlling the surface runoff of the storm events with return periods shorter than five years, in particular, for one-year events. Furthermore, the effectiveness on traffic congestion mitigation of several LID measures (concave greenbelt, vegetative swales, and comprehensive measures was evaluated. However, the effective return periods of storm events are shorter than two years if the effectiveness on traffic congestion relief is considered. In all evaluated aspects, comprehensive measures and concave greenbelts are the most effective, and vegetative swale is the least effective. This indicated that LID measures are less effective for removing ponding from most storm events in a mountainous, low-lying and backward pipeline infrastructure region with pressures from interval flooding and urban waterlogging. The engineering measures including water conservancy projects and pipeline infrastructure construction combined with the non-engineering measures were suggested to effectively control severe urban storms.

  10. Long-Term Effectiveness of the Zilver PTX Drug-Eluting Stent for Femoropopliteal Peripheral Artery Disease in Patients with No Patent Tibial Runoff Vessels-Results from the Zilver PTX Japan Post-Market Surveillance Study.

    Science.gov (United States)

    Cipollari, Stefano; Yokoi, Hiroyoshi; Ohki, Takao; Kichikawa, Kimihiko; Nakamura, Masato; Komori, Kimihiro; Nanto, Shinsuke; O'Leary, Erin E; Lottes, Aaron E; Saunders, Alan T; Dake, Michael D

    2018-01-01

    To evaluate 2-year results of the Zilver PTX (Cook Medical, Bloomington, Indiana) drug-eluting stent (DES) for femoropopliteal peripheral artery disease (PAD) in patients with no continuous patent infrapopliteal runoff arteries compared with patients with ≥ 1 continuous patent runoff vessels. A retrospective analysis of patients with femoropopliteal PAD enrolled in the Zilver PTX Post-Market Surveillance Study in Japan was performed. There were no exclusion criteria. Outcomes, including freedom from target lesion revascularization (TLR), patency, and clinical benefit, for the no-runoff group (n = 54) were compared with the runoff group (n = 846). The 2 groups were similar in terms of demographics, lesion characteristics, and comorbidities (P > .05). There was a higher incidence of critical limb ischemia in the no-runoff group compared with the runoff group (44.8% vs 19.7%; P < .01). There were 3 amputations (5.6%) in the no-runoff group versus 7 amputations (0.8%) in the runoff group (P = .02). At 2 years, freedom from TLR rates were 81.3% versus 83.8% (P = .87), patency rates were 68.4% versus 70.7% (P = .95), and clinical benefit rates were 73.7% versus 80.0% (P = .16) in the no-runoff versus runoff group, respectively. Results in patients with no continuous patent tibial runoff were favorable through 2 years and similar to results for patients with ≥ 1 continuous patent runoff vessels, indicating that the Zilver PTX DES may be a valid treatment option for patients with these difficult-to-treat lesions. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  11. Enhanced Access Design Alternative I Study

    International Nuclear Information System (INIS)

    Eble, G.B.

    1999-01-01

    The purpose of this document is to evaluate Enhanced Design Alternative (EDA) 1, the low temperature repository design concept (CRWMS M and O 1999a). This technical document will provide supporting information for Site Recommendation (SR) and License Application (LA). Preparation of this evaluation will be in accordance with the technical document preparation plan (TDPP), (CRWMS M and O 1999b). EDA 1, one of five EDAs, was evolved from evaluation of a series of design features and alternatives developed during the first phase of the License Application Design Selection (LADS) process. Low, medium, and high temperature concepts were developed from the design features and alternatives prepared during Phase 1 of the LADS effort (CRWMS M and O 1999a). EDA 1 will first be evaluated against a single Screening Criterion, outlined in CRWMS M and O 1999a, which addresses post-closure performance of the repository. The performance of the repository is defined quantitatively as the peak radiological dose rate to an average individual of a critical group at a distance of 20 km from the repository site within 10,000 years. To satisfy this criterion the peak dose rate must not exceed the anticipated regulatory level of 25 mrem/yr within 10,000 years. If the EDA meets the screening criterion, the EDA will be further evaluated against the LADS Phase 2 Evaluation Criteria contained in CRWMS M and O 1999a

  12. Integration of rainfall/runoff and geomorphological analyses flood hazard in small catchments: case studies from the southern Apennines (Italy)

    Science.gov (United States)

    Palumbo, Manuela; Ascione, Alessandra; Santangelo, Nicoletta; Santo, Antonio

    2017-04-01

    We present the first results of an analysis of flood hazard in ungauged mountain catchments that are associated with intensely urbanized alluvial fans. Assessment of hydrological hazard has been based on the integration of rainfall/runoff modelling of drainage basins with geomorphological analysis and mapping. Some small and steep, ungauged mountain catchments located in various areas of the southern Apennines, in southern Italy, have been chosen as test sites. In the last centuries, the selected basins have been subject to heavy and intense precipitation events, which have caused flash floods with serious damages in the correlated alluvial fan areas. Available spatial information (regional technical maps, DEMs, land use maps, geological/lithological maps, orthophotos) and an automated GIS-based procedure (ArcGis tools and ArcHydro tools) have been used to extract morphological, hydrological and hydraulic parameters. Such parameters have been used to run the HEC (Hydrologic Engineering Center of the US Army Corps of Engineers) software (GeoHMS, GeoRAS, HMS and RAS) based on rainfall-runoff models, which have allowed the hydrological and hydraulic simulations. As the floods occurred in the studied catchments have been debris flows dominated, the solid load simulation has been also performed. In order to validate the simulations, we have compared results of the modelling with the effects produced by past floods. Such effects have been quantified through estimations of both the sediment volumes within each catchment that have the potential to be mobilised (pre-event) during a sediment transfer event, and the volume of sediments delivered by the debris flows at basins' outlets (post-event). The post-event sediment volume has been quantified through post-event surveys and Lidar data. Evaluation of the pre-event sediment volumes in single catchments has been based on mapping of sediment storages that may constitute source zones of bed load transport and debris flows. For

  13. Simulation of Snowmelt Runoff Using SRM Model and Comparison With Neural Networks ANN and ANFIS (Case Study: Kardeh dam basin

    Directory of Open Access Journals (Sweden)

    morteza akbari

    2017-03-01

    Full Text Available Introduction: Snowmelt runoff plays an important role in providing water and agricultural resources, especially in mountainous areas. There are different methods to simulate the process of snowmelt. Inter alia, degree-day model, based on temperature-index is more cited. Snowmelt Runoff Model is a conceptual hydrological model to simulate and predict the daily flow of rivers in the mountainous basins on the basis of comparing the accuracy of AVHRR and TM satellite images to determine snow cover in Karun Basin. Additionally, overestimation of snow-covered area decreased with increasing spatial resolution of satellite data.Studies conducted in the Zayandehrood watershed dam, showed that in the calculation of the snow map cover, changes from MODIS satellite imagery, at the time that the image does not exist, using the digital elevation model and regression analysis can provide to estimate the appropriate data from satellites. In the study of snow cover in eastern Turkey, in the mountainous regions of the Euphrates River, data from five meteorological stations and MODIS images were used with a resolution of 500 m. The results showed that satellite images have a good accuracy in estimating snow cover. In a Watershed in northern Pakistan in the period from 2000 to 2006, SRM model was used to estimate the snow cover using MODIS images. The purpose of this study was to evaluate the snowmelt runoff using remote sensing data and SRM model for flow simulation, based on statistical parameters in the Kardeh dam basin. Materials and Methods: Kardeh dam basin has an area of about 560 square kilometers and is located in the north of Mashhad. This area is in the East of Hezarmasjed – kopehdagh zone that is one of the main basins of Kashafrood. This basin is a mountainous area. About 261 km of the basin is located at above 2000 m. The lowest point of the basin is at the watershed outlet with1300 meters and the highest point in the basin, in the North West part

  14. Limited Dissolved Phosphorus Runoff Losses from Layered Double Hydroxide and Struvite Fertilizers in a Rainfall Simulation Study.

    Science.gov (United States)

    Everaert, Maarten; da Silva, Rodrigo C; Degryse, Fien; McLaughlin, Mike J; Smolders, Erik

    2018-03-01

    The enrichment of P in surface waters has been linked to P runoff from agricultural fields amended with fertilizers. Novel slow-release mineral fertilizers, such as struvite and P-exchanged layered double hydroxides (LDHs), have received increasing attention for P recycling from waste streams, and these fertilizers may potentially reduce the risk of runoff losses. Here, a rainfall simulation experiment was performed to evaluate P runoff associated with the application of recycled slow-release fertilizers relative to that of a soluble fertilizer. Monoammonium phosphate (MAP), struvite, and LDH granular fertilizers were broadcasted at equal total P doses on soil packed in trays (5% slope) and covered with perennial ryegrass ( L.). Four rainfall simulation events of 30 min were performed at 1, 5, 15, and 30 d after the fertilizer application. Runoff water from the trays was collected, filtered, and analyzed for dissolved P. For the MAP treatment, P runoff losses were high in the first two rain events and leveled off in later rain events. In total, 42% of the applied P in the MAP treatment was lost due to runoff. In the slow-release fertilizer treatments, P runoff losses were limited to 1.9 (struvite) and 2.4% (LDH) of the applied doses and were more similar over the different rain events. The use of these novel P fertilizer forms could be beneficial in areas with a high risk of surface water eutrophication and a history of intensive fertilization. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  15. Categorical Alternatives: An Educational Criticism Study

    Directory of Open Access Journals (Sweden)

    Elizabeth J. EVANS

    2015-12-01

    Full Text Available In the writing of this paper, the design of which is based on Elliot Eisners Educational Criticism model, both linguistic and non-linguistic description were used to encourage the interpretation and evaluation of a specific and unique alternative educational setting. Five years ago, Ellens Learning Annex, a multi-age, one-room school house, was just next door to the researcher, while her son was struggling at the public school a mile away. A day spent observing Ellen and her students yielded data from which three general themes emerged: Heterogeneous age-grouping, place-based education, and sensory integration in a teaching and learning environment.

  16. Field-testing competing runoff source and hydrochemical conceptualisations

    Science.gov (United States)

    Western, A. W.; Saffarpour, S.; Adams, R.; Costelloe, J. F.; McDonnell, J.

    2014-12-01

    There are competing conceptualisations of heterogeneity in catchment systems. It is often convenient to divide catchments into zones, for example the soil profile, groundwater aquifers (saturated zone), riparian zones, etc. We also often divide flow sources into distinct categories such as surface runoff, interflow and baseflow, implying a few distinct stores of water. In tracer hydrology we typically assume water from such zones has distinct and invariant chemistry that is used to infer the runoff source mixture through conservative mixing model techniques such as End-Member Mixing Analysis (EMMA). An alternative conceptualisation is that catchments consist of a large number of stores with varying residence times. In this case individual stores contribute a variable proportion of flow and may have a temporally varying composition due to processes such as evapo-concentration. Hence they have a variable influence on the hydrochemistry of runoff. In this presentation, examples from two field studies in southern Australia will be presented that examine the relationships between hydrologic and hydrochemical conceptualisations and the relative variation within and between different hydrologic zones. The implications for water quality behaviour will be examined and the additional behavioural complexities associated with interactions between runoff pathways for non-conservative chemical species will be discussed.

  17. Specifics of surface runoff contents and treatment in large cities

    OpenAIRE

    V.N. Chechevichkin; N.I. Vatin

    2014-01-01

    The degree of surface runoff pollution in large cities has been assessed in modern conditions in the case study of production sites of St. Petersburg. Increased content of petroleum derivatives and heavy metal ions both in rainwater runoff and especially in snowmelt runoff has been revealed. It has been established that the composition of infiltration runoff from the newly built-up sites within the city limits commonly depends on their background, especially in the places of former unaut...

  18. Washoe Tribe Alternative Energy Feasibility Study Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Jennifer [Washoe Tribe of NV and CA

    2014-10-01

    The Washoe Tribe of Nevada and California was awarded funding to complete the Washoe Tribe Alternative Energy Feasibility Study project. The main goal of the project was to complete an alternative energy feasibility study. This study was completed to evaluate “the potential for development of a variety of renewable energy projects and to conduct an alternative energy feasibility study that determines which alternative energy resources have the greatest economic opportunity for the Tribe, while respecting cultural and environmental values” (Baker-Tilly, 2014). The study concluded that distributed generation solar projects are the best option for renewable energy development and asset ownership for the Washoe Tribe. Concentrating solar projects, utility scale wind projects, geothermal, and biomass resource projects were also evaluated during the study and it was determined that these alternatives would not be feasible at this time.

  19. RUNOFF HYDROGRAPHS USING SNYDER AND SCS SYNTHETIC UNIT HYDROGRAPH METHODS: A CASE STUDY OF SELECTED RIVERS IN SOUTH WEST NIGERIA

    Directory of Open Access Journals (Sweden)

    Wahab Adebayo Salami

    2017-01-01

    Full Text Available This paper presents the development of runoff hydrographs for selected rivers in Ogun-Osun river catchment, south west, Nigeria using Snyder and Soil Conservation Service (SCS methods of synthetic unit hydrograph to determine the ordinates. The Soil Conservation Service (SCS curve Number method was used to estimate the excess rainfall from storm of different return periods. The peak runoff hydrographs were determined by convoluting the unit hydrographs ordinates with the excess rainfall and the value of peak flows obtained by both Snyder and SCS methods observed to vary from one river watershed to the other. The peak runoff hydrograph flows obtained based on the unit hydrograph ordinate determined with Snyder method for 20-yr, 50-yr, 100-yr, 200-yr and 500-yr, return period varied from 112.63m3/s and 13364.30m3/s, while those based on the SCS method varied from 304.43m3/s and 6466.84m3/s for the eight watersheds. However, the percentage difference shows that for values of peak flows obtained with Snyder and SCS methods varies from 13.14% to 63.30%. However, SCS method is recommended to estimate the ordinate required for the development of peak runoff hydrograph in the river watersheds because it utilized additional morphometric parameters such as watershed slope and the curve number (CN which is a function of the properties of the soil and vegetation cover of the watershed.

  20. Rainfall and runoff regime trends in mountain catchments (Case study area: the upper Hron River basin, Slovakia

    Directory of Open Access Journals (Sweden)

    Blahušiaková Andrea

    2015-09-01

    Full Text Available This paper presents an analysis of trends and causes of changes of selected hydroclimatic variables influencing the runoff regime in the upper Hron River basin (Slovakia. Different methods for identifying trends in data series are evaluated and include: simple mass curve analysis, linear regression, frequency analysis of flood events, use of the Indicators of Hydrological Alteration software, and the Mann-Kendall test. Analyses are performed for data from two periods (1931-2010 and 1961-2010. The changes in runoff are significant, especially in terms of lower QMax and 75 percentile values. This fact is also confirmed by the lower frequency and extremity of flood events. The 1980s are considered a turning point in the development of all hydroclimatic variables. The Mann-Kendall test shows a significant decrease in runoff in the winter period. The main causes of runoff decline are: the considerable increase in air temperature, the decrease in snow cover depth and changes in seasonal distribution of precipitation amounts.

  1. Application of a satellite based rainfall - runoff model : a case study of the Trans Boundary Cuvelai Basin in Southern Africa

    NARCIS (Netherlands)

    Mufeti, P.; Rientjes, T.H.M.; Mabande, P.; Maathuis, B.H.P.

    2013-01-01

    Applications of distributed hydrological models are often constrained by poor data availability. Models rely on distributed inputs for meteorological forcing and land surface parameterization. In this pilot the rainfall runoff model LISFLOOD for large scale streamflow simulation is tested for the

  2. Runoff inundation hazard cartography

    Science.gov (United States)

    Pineux, N.; Degré, A.

    2012-04-01

    Between 1998 and 2004, Europe suffered from more than hundred major inundations, responsible for some 700 deaths, for the moving of about half a million of people and the economic losses of at least 25 billions Euros covered by the insurance policies. Within this context, EU launched the 2007/60/CE directive. The inundations are natural phenomenon. They cannot be avoided. Nevertheless this directive permits to better evaluate the risks and to coordinate the management measures taken at member states level. In most countries, inundation maps only include rivers' overflowing. In Wallonia, overland flows and mudflows also cause huge damages, and must be included in the flood hazard map. Indeed, the cleaning operations for a village can lead to an estimated cost of 11 000 €. Average construction cost of retention dams to control off-site damage caused by floods and muddy flows was valued at 380 000€, and yearly dredging costs associated with these retention ponds at 15 000€. For a small city for which a study was done in a more specific way (Gembloux), the mean annual cost for the damages that can generate the runoff is about 20 000€. This cost consists of the physical damages caused to the real estate and movable properties of the residents as well as the emergency operations of the firemen and the city. On top of damages to public infrastructure (clogging of trenches, silting up of retention ponds) and to private property by muddy flows, runoff generates a significant loss of arable land. Yet, the soil resource is not an unlimited commodity. Moreover, sediments' transfer to watercourses alters their physical and chemical quality. And that is not to mention the increased psychological stress for people. But to map overland flood and mud flow hazard is a real challenge. This poster will present the methodology used to in Wallonia. The methodology is based on 3 project rainfalls: 25, 50 and 100 years return period (consistency with the cartography of the

  3. A Future Estimation of the Surface Runoff in the Greek Region: A Case Study of one of the Main Catchments Areas (Aravissos - Central Macedonia)

    Science.gov (United States)

    Anagnostopoulou, C.; Tolika, K.; Vafiadis, M.

    2010-09-01

    According to the IPCC latest report (IPCC, 2007) many semi-arid and arid areas, as the Mediterranean basin, are particularly exposed to the impacts of climate change and may suffer a decrease of water resources in the future. By the middle of the 21st century it is estimated that the annual average river runoff and water availability will decrease over these dry regions at mid-latitudes. So, it is of great importance the study of the future changes in the hydrological cycle, due to the increasing freshwater demands. The main scope of the present study is to estimate the future changes of the surface runoff in the Aravissos area (central Macedonia - Greece) due to the enhanced greenhouse effect until the end of the 21st century. The selection of Aravissos was based to the fact that the water needs of the second largest in population city in Greece (Thessaloniki) are covered mainly by the selected catchments area. Daily precipitation, temperature, relative humidity, wind speed and sunlight duration data derived from updated regional climate models, are used for selected grid points covering the domain of study. The main two climatological parameters (precipitation -temperature) are on a first step evaluated in comparison to re-analysis data (E-Obs -Ensembles project) for the same grid points. On a second step, utilizing several different evapotranspiration methods we calculated the surface runoff for two different time periods: the first in the middle and the second at the end of the 21st century. The first results of the study showed that the surface runoff depends on the methodology used for the calculation of the evapotranspiration but also from the regional model. Acknowledgements: This study has been supported by the CC-WaterS project (Contract number SEE/A/022/2.1/X)

  4. Assessing the Impact of Forest Change and Climate Variability on Dry Season Runoff by an Improved Single Watershed Approach: A Comparative Study in Two Large Watersheds, China

    Directory of Open Access Journals (Sweden)

    Yiping Hou

    2018-01-01

    Full Text Available Extensive studies on hydrological responses to forest change have been published for centuries, yet partitioning the hydrological effects of forest change, climate variability and other factors in a large watershed remains a challenge. In this study, we developed a single watershed approach combining the modified double mass curve (MDMC and the time series multivariate autoregressive integrated moving average model (ARIMAX to separate the impact of forest change, climate variability and other factors on dry season runoff variation in two large watersheds in China. The Zagunao watershed was examined for the deforestation effect, while the Meijiang watershed was examined to study the hydrological impact of reforestation. The key findings are: (1 both deforestation and reforestation led to significant reductions in dry season runoff, while climate variability yielded positive effects in the studied watersheds; (2 the hydrological response to forest change varied over time due to changes in soil infiltration and evapotranspiration after vegetation regeneration; (3 changes of subalpine natural forests produced greater impact on dry season runoff than alteration of planted forests. These findings are beneficial to water resource and forest management under climate change and highlight a better planning of forest operations and management incorporated trade-off between carbon and water in different forests.

  5. Missing (in-situ) snow cover data hampers climate change and runoff studies in the Greater Himalayas.

    Science.gov (United States)

    Rohrer, Mario; Salzmann, Nadine; Stoffel, Markus; Kulkarni, Anil V

    2013-12-01

    The Himalayas are presently holding the largest ice masses outside the polar regions and thus (temporarily) store important freshwater resources. In contrast to the contemplation of glaciers, the role of runoff from snow cover has received comparably little attention in the past, although (i) its contribution is thought to be at least equally or even more important than that of ice melt in many Himalayan catchments and (ii) climate change is expected to have widespread and significant consequences on snowmelt runoff. Here, we show that change assessment of snowmelt runoff and its timing is not as straightforward as often postulated, mainly as larger partial pressure of H2O, CO2, CH4, and other greenhouse gases might increase net long-wave input for snowmelt quite significantly in a future atmosphere. In addition, changes in the short-wave energy balance - such as the pollution of the snow cover through black carbon - or the sensible or latent heat contribution to snowmelt are likely to alter future snowmelt and runoff characteristics as well. For the assessment of snow cover extent and depletion, but also for its monitoring over the extremely large areas of the Himalayas, remote sensing has been used in the past and is likely to become even more important in the future. However, for the calibration and validation of remotely-sensed data, and even more so in light of possible changes in snow-cover energy balance, we strongly call for more in-situ measurements across the Himalayas, in particular for daily data on new snow and snow cover water equivalent, or the respective energy balance components. Moreover, data should be made accessible to the scientific community, so that the latter can more accurately estimate climate change impacts on Himalayan snow cover and possible consequences thereof on runoff. © 2013 Elsevier B.V. All rights reserved.

  6. Coupling machine learning with mechanistic models to study runoff production and river flow at the hillslope scale

    Science.gov (United States)

    Marçais, J.; Gupta, H. V.; De Dreuzy, J. R.; Troch, P. A. A.

    2016-12-01

    Geomorphological structure and geological heterogeneity of hillslopes are major controls on runoff responses. The diversity of hillslopes (morphological shapes and geological structures) on one hand, and the highly non linear runoff mechanism response on the other hand, make it difficult to transpose what has been learnt at one specific hillslope to another. Therefore, making reliable predictions on runoff appearance or river flow for a given hillslope is a challenge. Applying a classic model calibration (based on inverse problems technique) requires doing it for each specific hillslope and having some data available for calibration. When applied to thousands of cases it cannot always be promoted. Here we propose a novel modeling framework based on coupling process based models with data based approach. First we develop a mechanistic model, based on hillslope storage Boussinesq equations (Troch et al. 2003), able to model non linear runoff responses to rainfall at the hillslope scale. Second we set up a model database, representing thousands of non calibrated simulations. These simulations investigate different hillslope shapes (real ones obtained by analyzing 5m digital elevation model of Brittany and synthetic ones), different hillslope geological structures (i.e. different parametrizations) and different hydrologic forcing terms (i.e. different infiltration chronicles). Then, we use this model library to train a machine learning model on this physically based database. Machine learning model performance is then assessed by a classic validating phase (testing it on new hillslopes and comparing machine learning with mechanistic outputs). Finally we use this machine learning model to learn what are the hillslope properties controlling runoffs. This methodology will be further tested combining synthetic datasets with real ones.

  7. IronMaking Process Alternatives Screening Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2000-10-01

    This study by Lockwood Greene evaluates a number ironmaking processes. The appendices provide greater detail and further exploration of the ironmaking processes, including components, relative costs, and comparisons.

  8. Modeling Ballasted Tracks for Runoff Coefficient C

    Science.gov (United States)

    2012-08-01

    In this study, the Regional Transportation District (RTD)s light rail tracks were modeled to determine the Rational Method : runoff coefficient, C, values corresponding to ballasted tracks. To accomplish this, a laboratory study utilizing a : rain...

  9. Alternative Frameworks for the Study of Man.

    Science.gov (United States)

    Markova, Ivana

    1979-01-01

    Two frameworks for the study of man are discussed. The Cartesian model views man as a physical object. A dialectic framework, with the emphasis on the self, grew out of nineteenth century romanticism and reflects the theories of Hegel. Both models have had an effect on social psychology and the study of interpersonal communication. (BH)

  10. Runoff from armored slopes

    International Nuclear Information System (INIS)

    Codell, R.B.

    1986-01-01

    Models exist for calculating overland flow on hillsides but no models have been found which explicitly deal with runoff from armored slopes. Flow on armored slopes differs from overland flow, because substantial flow occurs beneath the surface of the rock layer at low runnoff, and both above and below the surface for high runoff. In addition to the lack of a suitable model, no estimates of the PMP exist for such small areas and for very short durations. This paper develops a model for calculating runoff from armored embankments. The model considers the effect of slope, drainage area and ''flow concentration'' caused by irregular grading or slumping. A rainfall-duration curve based on the PMP is presented which is suitable for very small drainage areas. The development of the runoff model and rainfall-duration curve is presented below, along with a demonstration of the model on the design of a hypothetical tailings embankment

  11. Alternative Transportation Study : Monomoy National Wildlife Refuge.

    Science.gov (United States)

    2010-05-31

    This report provides an overview of the historic and current visitation, infrastructure, and transportation conditions related to Monomoy National Wildlife Refuge and the surrounding areas in Chatham, MA. The study defines transportation-related goal...

  12. Alternative transportation study : Wichita Mountains Wildlife Refuge

    Science.gov (United States)

    2010-08-01

    This report provides an assessment of historic and current visitation, infrastructure, and transportation conditions at the Wichita Mountains Wildlife Refuge and surrounding areas in southwest Oklahoma. The study defines transportation-related goals ...

  13. Abundance and fate of antibiotics and hormones in a vegetative treatment system receiving cattle feedlot runoff

    Science.gov (United States)

    Vegetative treatment systems (VTS) have been developed and built as an alternative to conventional holding pond systems for managing run-off from animal feeding operations. Initially developed to manage runoff nutrients via uptake by grasses, their effectiveness at removing other runoff contaminant...

  14. Low contrast volume run-off CT angiography with optimized scan time based on double-level test bolus technique – feasibility study

    International Nuclear Information System (INIS)

    Baxa, Jan; Vendiš, Tomáš; Moláček, Jiří; Štěpánková, Lucie; Flohr, Thomas; Schmidt, Bernhard; Korporaal, Johannes G.; Ferda, Jiří

    2014-01-01

    Purpose: To verify the technical feasibility of low contrast volume (40 mL) run-off CT angiography (run-off CTA) with the individual scan time optimization based on double-level test bolus technique. Materials and methods: A prospective study of 92 consecutive patients who underwent run-off CTA performed with 40 mL of contrast medium (injection rate of 6 mL/s) and optimized scan times on a second generation of dual-source CT. Individual optimized scan times were calculated from aortopopliteal transit times obtained on the basis of double-level test bolus technique – the single injection of 10 mL test bolus and dynamic acquisitions in two levels (abdominal aorta and popliteal arteries). Intraluminal attenuation (HU) was measured in 6 levels (aorta, iliac, femoral and popliteal arteries, middle and distal lower-legs) and subjective quality (3-point score) was assessed. Relations of image quality, test bolus parameters and arterial circulation involvement were analyzed. Results: High mean attenuation (HU) values (468; 437; 442; 440; 342; 274) and quality score in all monitored levels was achieved. In 91 patients (0.99) the sufficient diagnostic quality (score 1–2) in aorta, iliac and femoral arteries was determined. A total of 6 patients (0.07) were not evaluable in distal lower-legs. Only the weak indirect correlation of image quality and test-bolus parameters was proved in iliac, femoral and popliteal levels (r values: −0.263, −0.298 and −0.254). The statistically significant difference of the test-bolus parameters and image quality was proved in patients with occlusive and aneurysmal disease. Conclusion: We proved the technical feasibility and sufficient quality of run-off CTA with low volume of contrast medium and optimized scan time according to aortopopliteal transit time calculated from double-level test bolus

  15. Modelling rainfall runoff relations using HEC-HMS in a semi-arid region: Case study in Ain Sefra watershed, Ksour Mountains (SW Algeria

    Directory of Open Access Journals (Sweden)

    Derdour Abdessamed

    2018-03-01

    Full Text Available Ain Sefra is one of the Algerian cities that had been experienced several devastating floods during the past 100 years. The purpose of this study is to simulate runoff in the semi-arid region of Ain Sefra watershed through the employing of the Hydrologic Engineering Center – Hydrologic Modelling System (HEC-HMS. In this paper, the frequency storm is used for the meteorological model, the Soil Conservation Service – curve number (SCS-CN is selected to calculate the loss rate and Soil Conservation Service unit hydrograph method have been applied to simulate the runoff rate. After calibration and validation, the simulated peak discharges were very close with observed values. The Nash–Sutcliffe efficiency coefficient was 0.95, indicates that the hydrological modeling results are satisfactory and accepted for simulation of rainfall-runoff. The peak discharges obtained for the 10, 50, 100 and 1000 year storms are respectively 425.8, 750.5, 904.3 and 1328.3 m3∙s−1.

  16. Application of the Kineros model for predicting the effect of land use on the surface run-off Case study in Brantas sub-watershed, Klojen District, Malang City, East Java Province of Indonesia

    Directory of Open Access Journals (Sweden)

    Bisri Mohammad

    2017-12-01

    Full Text Available This study intended to illustrate the distribution of surface run-off. The methodology was by using Kineros model (kinetic run-off and erosion model. This model is a part of AGWA program which is as the development of ESRI ArcView SIG software that is as a tool for analysing hydrological phenomena in research about watershed simulating the process of infiltration, run-off depth, and erosion in a watershed of small scale such as ≤100 km2. The procedures are as follow: to analyse the run-off depth in Brantas sub-watershed, Klojen District by using Kineros model based on the land use change due to the rainfall simulation with the return period of 2 years, 5 years, 10 years, and 25 years. Results show that the difference of land use affect the surface run-off or there is the correlation between land use and surface run-off depth. The maximum surface run-off depth in the year 2000 was 134.26 mm; in 2005 it was 139.36 mm; and in 2010 it was 142.76 mm. There was no significant difference between Kineros model and observation in field, the relative error was only 9.09%.

  17. Application of artificial neural networks in hydrological modeling: A case study of runoff simulation of a Himalayan glacier basin

    Science.gov (United States)

    Buch, A. M.; Narain, A.; Pandey, P. C.

    1994-01-01

    The simulation of runoff from a Himalayan Glacier basin using an Artificial Neural Network (ANN) is presented. The performance of the ANN model is found to be superior to the Energy Balance Model and the Multiple Regression model. The RMS Error is used as the figure of merit for judging the performance of the three models, and the RMS Error for the ANN model is the latest of the three models. The ANN is faster in learning and exhibits excellent system generalization characteristics.

  18. Mobile radio alternative systems study traffic model

    Science.gov (United States)

    Tucker, W. T.; Anderson, R. E.

    1983-06-01

    The markets for mobile radio services in non-urban areas of the United States are examined for the years 1985-2000. Three market categories are identified. New Services are defined as those for which there are different expressed ideas but which are not now met by any application of available technology. The complete fulfillment of the needs requires nationwide radio access to vehicles without knowledge of vehicle location, wideband data transmission from remote sites, one- and two way exchange of short data and control messages between vehicles and dispatch or control centers, and automatic vehicle location (surveillance). The commercial and public services market of interest to the study is drawn from existing users of mobile radio in non-urban areas who are dissatisfied with the geographical range or coverage of their systems. The mobile radio telephone market comprises potential users who require access to the public switched telephone network in areas that are not likely to be served by the traditional growth patterns of terrestrial mobile telephone services. Conservative, likely, and optimistic estimates of the markets are presented in terms of numbers of vehicles that will be served and the radio traffic they will generate.

  19. Calibration and verification of numerical runoff and erosion model

    Directory of Open Access Journals (Sweden)

    Gabrić Ognjen

    2015-01-01

    Full Text Available Based on the field and laboratory measurements, and analogous with development of computational techniques, runoff and erosion models based on equations which describe the physics of the process are also developed. Based on the KINEROS2 model, this paper presents basic modelling principles of runoff and erosion processes based on the St. Venant's equations. Alternative equations for friction calculation, calculation of source and deposition elements and transport capacity are also shown. Numerical models based on original and alternative equations are calibrated and verified on laboratory scale model. According to the results, friction calculation based on the analytic solution of laminar flow must be included in all runoff and erosion models.

  20. Quality of urban runoff in wet and dry seasons: a case study in a semi-arid zone.

    Science.gov (United States)

    Ortiz-Hernández, Joyce; Lucho-Constantino, Carlos; Lizárraga-Mendiola, Liliana; Beltrán-Hernández, Rosa Icela; Coronel-Olivares, Claudia; Vázquez-Rodríguez, Gabriela

    2016-12-01

    Urban runoff (UR) is a promising new resource that may alleviate growing tensions in numerous arid and semi-arid regions of the world. However, it is precisely in these zones that the available UR quality characteristics are scarcer. This work aims to evaluate a wide set of parameters to establish a detailed approach to both the quality of UR in a midsized city in Central Mexico and the feasibility of using UR to recharge aquifers. UR from an institutional land use site was sampled during wet and dry seasons and assessed for suspended solids, organic matter, nutrients, microorganisms, metals, and persistent organic chemicals (i.e., polycyclic aromatic hydrocarbons, PAH). The results were analyzed using multivariate statistical methods to identify relationships among the variables, the sampling sites and the seasons. The soil erosion and the leaching of materials due to the water flow through vegetated areas were identified as the most influencing factor on the quality of the site runoff in both dry and wet seasons. Additionally, data were more heterogeneous during the dry season, and higher pollutant concentrations were found both during the dry season and in more pervious zones. We consider UR a promising water source for recharging aquifers in arid and semi-arid zones if a program is implemented that can integrate an adequate runoff treatment system, soil protection, and other non-structural measures.

  1. Sandy Hook : alternative access concept plan and vehicle replacement study

    Science.gov (United States)

    2009-06-01

    This study addresses two critical issues of concern to the Sandy Hook Unit of Gateway National : Recreational Area: (1) options for alternative access to Sandy Hook during peak summer season, : particularly when the park is closed to private vehicles...

  2. Missing (in-situ) snow cover data hampers climate change and runoff studies in the Greater Himalayas

    International Nuclear Information System (INIS)

    Rohrer, Mario; Salzmann, Nadine; Stoffel, Markus; Kulkarni, Anil V.

    2013-01-01

    The Himalayas are presently holding the largest ice masses outside the polar regions and thus (temporarily) store important freshwater resources. In contrast to the contemplation of glaciers, the role of runoff from snow cover has received comparably little attention in the past, although (i) its contribution is thought to be at least equally or even more important than that of ice melt in many Himalayan catchments and (ii) climate change is expected to have widespread and significant consequences on snowmelt runoff. Here, we show that change assessment of snowmelt runoff and its timing is not as straightforward as often postulated, mainly as larger partial pressure of H 2 O, CO 2 , CH 4 , and other greenhouse gases might increase net long-wave input for snowmelt quite significantly in a future atmosphere. In addition, changes in the short-wave energy balance – such as the pollution of the snow cover through black carbon – or the sensible or latent heat contribution to snowmelt are likely to alter future snowmelt and runoff characteristics as well. For the assessment of snow cover extent and depletion, but also for its monitoring over the extremely large areas of the Himalayas, remote sensing has been used in the past and is likely to become even more important in the future. However, for the calibration and validation of remotely-sensed data, and even more so in light of possible changes in snow-cover energy balance, we strongly call for more in-situ measurements across the Himalayas, in particular for daily data on new snow and snow cover water equivalent, or the respective energy balance components. Moreover, data should be made accessible to the scientific community, so that the latter can more accurately estimate climate change impacts on Himalayan snow cover and possible consequences thereof on runoff. - Highlights: • Remotely sensed snow-cover data need to be validated by in-situ measurements. • More in-situ snow measurement programs are needed along

  3. Missing (in-situ) snow cover data hampers climate change and runoff studies in the Greater Himalayas

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, Mario [Meteodat GmbH, Technoparkstrasse 1, CH-8005 Zurich (Switzerland); Salzmann, Nadine [Department of Geosciences, Geography, University of Fribourg, Chemin du Musée 4, CH-1700 Fribourg (Switzerland); Stoffel, Markus, E-mail: markus.stoffel@unige.ch [Institute for Environmental Sciences, University of Geneva, Chemin de Drize 7, CH-1227 Carouge, Geneva (Switzerland); Dendrolab.ch, Institute of Geological Sciences, University of Bern, Baltzerstrasse 1+3, CH-3012 Bern (Switzerland); Kulkarni, Anil V. [Divecha Center for Climate Change, Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bangalore 560 012 (India)

    2013-12-01

    The Himalayas are presently holding the largest ice masses outside the polar regions and thus (temporarily) store important freshwater resources. In contrast to the contemplation of glaciers, the role of runoff from snow cover has received comparably little attention in the past, although (i) its contribution is thought to be at least equally or even more important than that of ice melt in many Himalayan catchments and (ii) climate change is expected to have widespread and significant consequences on snowmelt runoff. Here, we show that change assessment of snowmelt runoff and its timing is not as straightforward as often postulated, mainly as larger partial pressure of H{sub 2}O, CO{sub 2}, CH{sub 4}, and other greenhouse gases might increase net long-wave input for snowmelt quite significantly in a future atmosphere. In addition, changes in the short-wave energy balance – such as the pollution of the snow cover through black carbon – or the sensible or latent heat contribution to snowmelt are likely to alter future snowmelt and runoff characteristics as well. For the assessment of snow cover extent and depletion, but also for its monitoring over the extremely large areas of the Himalayas, remote sensing has been used in the past and is likely to become even more important in the future. However, for the calibration and validation of remotely-sensed data, and even more so in light of possible changes in snow-cover energy balance, we strongly call for more in-situ measurements across the Himalayas, in particular for daily data on new snow and snow cover water equivalent, or the respective energy balance components. Moreover, data should be made accessible to the scientific community, so that the latter can more accurately estimate climate change impacts on Himalayan snow cover and possible consequences thereof on runoff. - Highlights: • Remotely sensed snow-cover data need to be validated by in-situ measurements. • More in-situ snow measurement programs are

  4. Catchment Morphing (CM): A Novel Approach for Runoff Modeling in Ungauged Catchments

    Science.gov (United States)

    Zhang, Jun; Han, Dawei

    2017-12-01

    Runoff prediction in ungauged catchments has been one of the major challenges in the past decades. However, due to the tremendous heterogeneity of the catchments, obstacles exist in deducing model parameters for ungauged catchments from gauged ones. We propose a novel approach to predict ungauged runoff with Catchment Morphing (CM) using a fully distributed model. CM is defined as by changing the catchment characteristics (area and slope here) from the baseline model built with a gauged catchment to model the ungauged ones. As a proof of concept, a case study on seven catchments in the UK has been used to demonstrate the proposed scheme. Comparing the predicted with measured runoff, the Nash-Sutcliffe efficiency (NSE) varies from 0.03 to 0.69 in six catchments. Moreover, NSEs are significantly improved (up to 0.81) when considering the discrepancy of percentage runoff between the target and baseline catchments. A distinct advantage has been experienced by comparing the CM with a traditional method for ungauged catchments. The advantages are: (a) less demand of the similarity between the baseline catchment and the ungauged catchment, (b) less demand of available data, and (c) potentially widely applicable in varied catchments. This study demonstrates the feasibility of the proposed scheme as a potentially powerful alternative to the conventional methods in runoff predictions of ungauged catchments. Clearly, more work beyond this pilot study is needed to explore and develop this new approach further to maturity by the hydrological community.

  5. Physicochemical conditions and properties of particles in urban runoff and rivers: Implications for runoff pollution.

    Science.gov (United States)

    Wang, Qian; Zhang, Qionghua; Wu, Yaketon; Wang, Xiaochang C

    2017-04-01

    In this study, to gain an improved understanding of the fate and fractionation of particle-bound pollutants, we evaluated the physicochemical conditions and the properties of particles in rainwater, urban runoff, and rivers of Yixing, a city with a large drainage density in the Taihu Lake Basin, China. Road runoff and river samples were collected during the wet and dry seasons in 2015 and 2016. There were significant differences between the physicochemical conditions (pH, oxidation-reduction potential (ORP), and electroconductivity (EC)) of rainwater, runoff, and rivers. The lowest pH and highest ORP values of rainwater provide the optimal conditions for leaching of particle-bound pollutants such as heavy metals. The differences in the physicochemical conditions of the runoff and rivers may contribute to the redistribution of pollutants between particulate and dissolved phases after runoff is discharged into waterways. Runoff and river particles were mainly composed of silt and clay (runoff particles contained a higher proportion of nano-scale particles (runoff pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Estimating Runoff Coefficients Using Weather Radars

    DEFF Research Database (Denmark)

    Ahm, Malte; Thorndahl, Søren Liedtke; Rasmussen, Michael R.

    2012-01-01

    This paper presents a method for estimating runoff coefficients of urban drainage catchments based on a combination of high resolution weather radar data and insewer flow measurements. By utilising the spatial variability of the precipitation it is possible to estimate the runoff coefficients...... of separate subcatchments. The method is demonstrated through a case study of an urban drainage catchment (678ha) located in the municipality of Aarhus, Denmark. The study has proven it is possible to use corresponding measurements of the relative rainfall distribution over the catchment and runoff...... measurements to identify the runoff coefficients at subcatchment level. The number of potential subcatchments is limited by the number of available rainfall events with a sufficient spatial variability....

  7. RUNOFF POTENTIAL OF MUREŞ RIVER UPPER BASIN TRIBUTARIES

    Directory of Open Access Journals (Sweden)

    V. SOROCOVSCHI

    2012-03-01

    Full Text Available Runoff Potential of Mureş River Upper Basin Tributaries. The upper basin of the Mureş River includes a significant area of the Eastern Carpathians central western part with different runoff formation conditions. In assessing the average annual runoff potential we used data from six gauging stations and made assessments on three distinct periods. Identifying the appropriate areas of the obtained correlations curves (between specific average runoff and catchments mean altitude allowed the assessment of potential runoff at catchment level and on geographical units. The potential average runoff is also assessed on altitude intervals of the mentioned areas. The runoff potential analysis on hydrographic basins, geographical units and altitude intervals highlights the variant spatial distribution of this general water resources indicator in the different studied areas.

  8. Nonlinear response in runoff magnitude to fluctuating rain patterns.

    Science.gov (United States)

    Curtu, R; Fonley, M

    2015-03-01

    The runoff coefficient of a hillslope is a reliable measure for changes in the streamflow response at the river link outlet. A high runoff coefficient is a good indicator of the possibility of flash floods. Although the relationship between runoff coefficient and streamflow has been the subject of much study, the physical mechanisms affecting runoff coefficient including the dependence on precipitation pattern remain open topics for investigation. In this paper, we analyze a rainfall-runoff model at the hillslope scale as that hillslope is forced with different rain patterns: constant rain and fluctuating rain with different frequencies and amplitudes. When an oscillatory precipitation pattern is applied, although the same amount of water may enter the system, its response (measured by the runoff coefficient) will be maximum for a certain frequency of precipitation. The significant increase in runoff coefficient after a certain pattern of rainfall can be a potential explanation for the conditions preceding flash-floods.

  9. Influence of Cattle Trails on Runoff Quantity and Quality.

    Science.gov (United States)

    Miller, Jim J; Curtis, Tony; Chanasyk, David S; Willms, Walter D

    2017-03-01

    Cattle trails in grazed pastures close to rivers may adversely affect surface water quality of the adjacent river by directing runoff to it. The objective of this 3-yr study (2013-2015) in southern Alberta, Canada, was to determine if cattle trails significantly increased the risk of runoff and contaminants (sediment, nutrients) compared with the adjacent grazed pasture (control). A portable rainfall simulator was used to generate artificial rainfall (140 mm h) and runoff. The runoff properties measured were time to runoff and initial abstraction (infiltration), total runoff depth and average runoff rates, as well as concentrations and mass loads of sediment, N, and P fractions. Cattle trails significantly ( ≤ 0.10) decreased time to runoff and initial abstraction (26-32%) in the 2 yr measured and increased total runoff depth, runoff coefficients, and average runoff rates (21-51%) in 2 of 3 yr. Concentrations of sediment, N, and P fractions in runoff were not significantly greater for cattle trails than for control areas. However, mass loads of total suspended solids (57-85% increase), NH-N (31-90%), and dissolved reactive P (DRP) (30-92%) were significantly greater because of increased runoff volumes. Overall, runoff quantity and loads of sediment, NH-N, and DRP were greater for cattle trails compared with the adjacent grazed pasture, and hydrologic connection with cattle-access sites on the riverbank suggests that this could adversely affect water quality in the adjacent river. Extrapolation of the study results should be tempered by the specific conditions represented by this rainfall simulation study. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  10. Modeling rainfall-runoff process using soft computing techniques

    Science.gov (United States)

    Kisi, Ozgur; Shiri, Jalal; Tombul, Mustafa

    2013-02-01

    Rainfall-runoff process was modeled for a small catchment in Turkey, using 4 years (1987-1991) of measurements of independent variables of rainfall and runoff values. The models used in the study were Artificial Neural Networks (ANNs), Adaptive Neuro-Fuzzy Inference System (ANFIS) and Gene Expression Programming (GEP) which are Artificial Intelligence (AI) approaches. The applied models were trained and tested using various combinations of the independent variables. The goodness of fit for the model was evaluated in terms of the coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE), coefficient of efficiency (CE) and scatter index (SI). A comparison was also made between these models and traditional Multi Linear Regression (MLR) model. The study provides evidence that GEP (with RMSE=17.82 l/s, MAE=6.61 l/s, CE=0.72 and R2=0.978) is capable of modeling rainfall-runoff process and is a viable alternative to other applied artificial intelligence and MLR time-series methods.

  11. A study of alternative splicing in the pig

    Directory of Open Access Journals (Sweden)

    Jørgensen Claus B

    2010-05-01

    Full Text Available Abstract Background Since at least half of the genes in mammalian genomes are subjected to alternative splicing, alternative pre-mRNA splicing plays an important contribution to the complexity of the mammalian proteome. Expressed sequence tags (ESTs provide evidence of a great number of possible alternative isoforms. With the EST resource for the domestic pig now containing more than one million porcine ESTs, it is possible to identify alternative splice forms of the individual transcripts in this species from the EST data with some confidence. Results The pig EST data generated by the Sino-Danish Pig Genome project has been assembled with publicly available ESTs and made available in the PigEST database. Using the Distiller package 2,515 EST clusters with candidate alternative isoforms were identified in the EST data with high confidence. In agreement with general observations in human and mouse, we find putative splice variants in about 30% of the contigs with more than 50 ESTs. Based on the criteria that a minimum of two EST sequences confirmed each splice event, a list of 100 genes with the most distinct tissue-specific alternative splice events was generated from the list of candidates. To confirm the tissue specificity of the splice events, 10 genes with functional annotation were randomly selected from which 16 individual splice events were chosen for experimental verification by quantitative PCR (qPCR. Six genes were shown to have tissue specific alternatively spliced transcripts with expression patterns matching those of the EST data. The remaining four genes had tissue-restricted expression of alternative spliced transcripts. Five out of the 16 splice events that were experimentally verified were found to be putative pig specific. Conclusions In accordance with human and rodent studies we estimate that approximately 30% of the porcine genes undergo alternative splicing. We found a good correlation between EST predicted tissue

  12. Runoff projection under climate change over Yarlung Zangbo River, Southwest China

    Science.gov (United States)

    Xuan, Weidong; Xu, Yue-Ping

    2017-04-01

    The Yarlung Zangbo River is located in southwest of China, one of the major source of "Asian water tower". The river has great hydropower potential and provides vital water resource for local and downstream agricultural production and livestock husbandry. Compared to its drainage area, gauge observation is sometimes not enough for good hydrological modeling in order to project future runoff. In this study, we employ a semi-distributed hydrologic model SWAT to simulate hydrological process of the river with rainfall observation and TRMM 3B4V7 respectively and the hydrological model performance is evaluated based on not only total runoff but snowmelt, precipitation and groundwater components. Firstly, calibration and validation of the hydrological model are executed to find behavioral parameter sets for both gauge observation and TRMM data respectively. Then, behavioral parameter sets with diverse efficiency coefficient (NS) values are selected and corresponding runoff components are analyzed. Robust parameter sets are further employed in SWAT coupled with CMIP5 GCMs to project future runoff. The final results show that precipitation is the dominating contributor nearly all year around, while snowmelt and groundwater are important in the summer and winter alternatively. Also sufficient robust parameter sets help reduce uncertainty in hydrological modeling. Finally, future possible runoff changes will have major consequences for water and flood security.

  13. Modelling rainfall runoff relations using HEC-HMS in a semi-arid region: Case study in Ain Sefra watershed, Ksour Mountains (SW Algeria)

    OpenAIRE

    Derdour Abdessamed; Bouanani Abderrazak; Babahamed Kamila

    2018-01-01

    Ain Sefra is one of the Algerian cities that had been experienced several devastating floods during the past 100 years. The purpose of this study is to simulate runoff in the semi-arid region of Ain Sefra watershed through the employing of the Hydrologic Engineering Center – Hydrologic Modelling System (HEC-HMS). In this paper, the frequency storm is used for the meteorological model, the Soil Conservation Service – curve number (SCS-CN) is selected to calculate the loss rate and Soil Conserv...

  14. Downscaling of a global climate model for estimation of runoff, sediment yield and dam storage: A case study of Pirapama basin, Brazil

    Science.gov (United States)

    Braga, Ana Cláudia F. Medeiros; Silva, Richarde Marques da; Santos, Celso Augusto Guimarães; Galvão, Carlos de Oliveira; Nobre, Paulo

    2013-08-01

    The coastal zone of northeastern Brazil is characterized by intense human activities and by large settlements and also experiences high soil losses that can contribute to environmental damage. Therefore, it is necessary to build an integrated modeling-forecasting system for rainfall-runoff erosion that assesses plans for water availability and sediment yield that can be conceived and implemented. In this work, we present an evaluation of an integrated modeling system for a basin located in this region with a relatively low predictability of seasonal rainfall and a small area (600 km2). The National Center for Environmental Predictions - NCEP’s Regional Spectral Model (RSM) nested within the Center for Weather Forecasting and Climate Studies - CPTEC’s Atmospheric General Circulation Model (AGCM) were investigated in this study, and both are addressed in the simulation work. The rainfall analysis shows that: (1) the dynamic downscaling carried out by the regional RSM model approximates the frequency distribution of the daily observed data set although errors were detected in the magnitude and timing (anticipation of peaks, for example) at the daily scale, (2) an unbiased precipitation forecast seemed to be essential for use of the results in hydrological models, and (3) the information directly extracted from the global model may also be useful. The simulated runoff and reservoir-stored volumes are strongly linked to rainfall, and their estimation accuracy was significantly improved at the monthly scale, thus rendering the results useful for management purposes. The runoff-erosion forecasting displayed a large sediment yield that was consistent with the predicted rainfall.

  15. Propagation of soil moisture memory to runoff and evapotranspiration

    Science.gov (United States)

    Orth, R.; Seneviratne, S. I.

    2012-10-01

    As a key variable of the land-climate system soil moisture is a main driver of runoff and evapotranspiration under certain conditions. Soil moisture furthermore exhibits outstanding memory (persistence) characteristics. Also for runoff many studies report distinct low frequency variations that represent a memory. Using data from over 100 near-natural catchments located across Europe we investigate in this study the connection between soil moisture memory and the respective memory of runoff and evapotranspiration on different time scales. For this purpose we use a simple water balance model in which dependencies of runoff (normalized by precipitation) and evapotranspiration (normalized by radiation) on soil moisture are fitted using runoff observations. The model therefore allows to compute memory of soil moisture, runoff and evapotranspiration on catchment scale. We find considerable memory in soil moisture and runoff in many parts of the continent, and evapotranspiration also displays some memory on a monthly time scale in some catchments. We show that the memory of runoff and evapotranspiration jointly depend on soil moisture memory and on the strength of the coupling of runoff and evapotranspiration to soil moisture. Furthermore we find that the coupling strengths of runoff and evapotranspiration to soil moisture depend on the shape of the fitted dependencies and on the variance of the meteorological forcing. To better interpret the magnitude of the respective memories across Europe we finally provide a new perspective on hydrological memory by relating it to the mean duration required to recover from anomalies exceeding a certain threshold.

  16. A comparative study of the grain-size distribution of surface dust and stormwater runoff quality on typical urban roads and roofs in Beijing, China.

    Science.gov (United States)

    Shen, Zhenyao; Liu, Jin; Aini, Guzhanuer; Gong, Yongwei

    2016-02-01

    The deposition of pollutants on impervious surfaces is a serious problem associated with rapid urbanization, which results in non-point-source pollution. Characterizing the build-up and wash-off processes of pollutants in urban catchments is essential for urban planners. In this paper, the spatial variation and particle-size distributions of five heavy metals and two nutrients in surface dust were analyzed, and the runoff water first-flush effect (FF30) and event-mean concentrations (EMCs) of 10 common constituents were characterized. The relationships between runoff variables and stormwater characteristics were examined from three typical urban impervious surfaces in Beijing, China. Dust on road surfaces with smaller grain sizes had higher pollutant concentrations, whereas concentrations of Mn, Zn, Fe, and TP in roof surface dust increased with grain size. Particles with grain sizes of 38-74 and 125-300 μm contributed most to the total pollutant load in roads, while particles with the smallest grain sizes (roads. The maximum intensity (I max) and the antecedent dry days (ADD) were critical parameters for EMCs in roads, while ADD was the only dominant parameter for EMCs on our studied roof. The rainfall intensity (RI) and maximum intensity (I max) were found to be the parameters with the strongest correlation to the first-flush effect on both roads and roofs. Significant correlations of total suspended solids (TSS) concentration in runoff with grain-size fractions of surface dust indicated that coarser particles (74-300 μm) are most likely to contribute to the solid-phase pollutants, and finer particles (<38 μm) are likely the main source of dissolved pollutants.

  17. A simulation study of the recession coefficient for antecedent precipitation index. [soil moisture and water runoff estimation

    Science.gov (United States)

    Choudhury, B. J.; Blanchard, B. J.

    1981-01-01

    The antecedent precipitation index (API) is a useful indicator of soil moisture conditions for watershed runoff calculations and recent attempts to correlate this index with spaceborne microwave observations have been fairly successful. It is shown that the prognostic equation for soil moisture used in some of the atmospheric general circulation models together with Thornthwaite-Mather parameterization of actual evapotranspiration leads to API equations. The recession coefficient for API is found to depend on climatic factors through potential evapotranspiration and on soil texture through the field capacity and the permanent wilting point. Climatologial data for Wisconsin together with a recently developed model for global isolation are used to simulate the annual trend of the recession coefficient. Good quantitative agreement is shown with the observed trend at Fennimore and Colby watersheds in Wisconsin. It is suggested that API could be a unifying vocabulary for watershed and atmospheric general circulation modelars.

  18. Multi-scale response of runoff to climate fluctuation in the headwater region of Kaidu River in Xinjiang of China

    Science.gov (United States)

    Bai, Ling; Chen, Zhongsheng; Xu, Jianhua; Li, Weihong

    2016-08-01

    Based on the hydrological and meteorological data in the headwater region of the Kaidu River during 1960-2009, the multi-scale characteristics of runoff variability were analyzed using the ensemble empirical mode decomposition method (EEMD), and the aim is to investigate the oscillation mode structure characteristics of runoff change and its response to climate fluctuation at different time scales. Results indicated that in the past 50 years, the overall runoff of Kaidu River in Xinjiang has showed a significant nonlinear upward trend, and its changes have obviously exhibited an inter-annual scale (quasi-3 and quasi-6-year) and inter-decadal scale (quasi-10 and quasi-25-year). Variance contribution rates of each component manifested that the inter-decadal change had been playing a more important role in the overall runoff change for Kaidu River, and the reconstructed inter-annual variation trend could describe the fluctuation state of the original runoff anomaly during the study period. The reconstructed inter-decadal variability effectively revealed that the runoff for Kaidu River changed over the years, namely the states of abundance and low water period appear alternately. In addition, we found that runoff has a positive correlation to precipitation and temperature at different time scales, but they are most significant and relevant at inter-decadal scale, indicating the inter-decadal scale is most suitable for investigating the responses of runoff dynamics to climate fluctuation. At the same time, the results also suggested that EEMD is an effective method to analyze the multi-scale characteristics of nonlinear and non-stationary signal.

  19. Project on Alternative Systems Study - PASS. Final report

    International Nuclear Information System (INIS)

    1992-10-01

    Alternative repository systems for deep disposal of spent fuel and different types of canisters are studied regarding technical aspects in Project on Alternative System Study (PASS). The objective is to present a ranking of repository systems as well as of canister types for each system. The studies and compared systems are: KBS-3, Medium Long Tunnels (MLH), Long tunnels (VLH) and Deep Boreholes (VDH). For KBS-3 and MLH five canister types are compared (copper/steel, copper/lead, copper (HIP), steel/lead and steel), for VLH two types (copper/steel and steel), and for VDH three types (titanium/concrete with non-consolidated fuel assemblies, titanium/concrete with consolidated assemblies and copper (HIP) with non-consolidated assemblies). The comparison is separated into three sub-comparisons (Technology, Long-term performance and safety, and Costs), which eventually are merged into one ranking. With respect to canister alternatives the result is that the copper/steel canister is ranked first for KBS-3, MLH and VLH, while the titanium/concrete canister is ranked first for VDH (non-consolidated as well as consolidated assemblies. With these canister alternatives the merged ranking of repository systems results in placing KBS-3 slightly in front of MLH. VLH comes thereafter and VDH last. (32 refs.)

  20. Estimation of reservoir inflow in data scarce region by using Sacramento rainfall runoff model - A case study for Sittaung River Basin, Myanmar

    Science.gov (United States)

    Myo Lin, Nay; Rutten, Martine

    2017-04-01

    The Sittaung River is one of four major rivers in Myanmar. This river basin is developing fast and facing problems with flood, sedimentation, river bank erosion and salt intrusion. At present, more than 20 numbers of reservoirs have already been constructed for multiple purposes such as irrigation, domestic water supply, hydro-power generation, and flood control. The rainfall runoff models are required for the operational management of this reservoir system. In this study, the river basin is divided into (64) sub-catchments and the Sacramento Soil Moisture Accounting (SAC-SMA) models are developed by using satellite rainfall and Geographic Information System (GIS) data. The SAC-SMA model has sixteen calibration parameters, and also uses a unit hydrograph for surface flow routing. The Sobek software package is used for SAC-SMA modelling and simulation of river system. The models are calibrated and tested by using observed discharge and water level data. The statistical results show that the model is applicable to use for data scarce region. Keywords: Sacramento, Sobek, rainfall runoff, reservoir

  1. Identifying the Tillage Effects on Phosphorus Export from Phaeozems-Dominated Agricultural Watershed: a Plot-Scale Rainfall-Runoff Study in Northeast China

    Science.gov (United States)

    Zhou, Yuyan; Xu, Y. Jun; Xiao, Weihua; Wang, Jianhua; Hao, Cailian; Zhou, Pu; Shi, Min

    2017-12-01

    Evaluating tillage effects on soil phosphorus (P) loss at the plot-scale has significant implication for developing best management practices (BMPs) to protect water quality and soil productivity management in agricultural watersheds. This paper aims to quantify P loss from tilled soils under different rainfall patterns in a Phaeozems-dominated agricultural watershed. Eleven rainfall events were monitored at three experimental sites growing corns with conventional till, conservational till, and no-till during a growing season from July to August in 2013. Mean event mean concentration of dissolved phosphorus was 0.130, 0.213 and 0.614 mg L-1 and mean particulate phosphorus transfer rate was 103.502, 33.359 and 27.127 g ha-1 hr-1, respectively for three tillage practices. Results showed that less tillage practices could significantly reduce sediment runoff and PP loss, accompanied with a moderate reduction of runoff yield. While the proportion of PP has been cut down, the proportion of DP could account for the majority. Hydrological factors, including antecedent soil moisture and rainfall variables, could exert various effects on DP, PP and sediment losses under different tillage conditions. Further, the results of this study imply that the soil P loss management and water quality protection in black soil region of Northeast China should take consideration of diverse effects of tillage on phosphorus loss and the dynamics of P between different forms.

  2. Runoff estimation in residencial area

    Directory of Open Access Journals (Sweden)

    Meire Regina de Almeida Siqueira

    2013-12-01

    Full Text Available This study aimed to estimate the watershed runoff caused by extreme events that often result in the flooding of urban areas. The runoff of a residential area in the city of Guaratinguetá, São Paulo, Brazil was estimated using the Curve-Number method proposed by USDA-NRCS. The study also investigated current land use and land cover conditions, impermeable areas with pasture and indications of the reforestation of those areas. Maps and satellite images of Residential Riverside I Neighborhood were used to characterize the area. In addition to characterizing land use and land cover, the definition of the soil type infiltration capacity, the maximum local rainfall, and the type and quality of the drainage system were also investigated. The study showed that this neighborhood, developed in 1974, has an area of 792,700 m², a population of 1361 inhabitants, and a sloping area covered with degraded pasture (Guaratinguetá-Piagui Peak located in front of the residential area. The residential area is located in a flat area near the Paraiba do Sul River, and has a poor drainage system with concrete pipes, mostly 0.60 m in diameter, with several openings that capture water and sediments from the adjacent sloping area. The Low Impact Development (LID system appears to be a viable solution for this neighborhood drainage system. It can be concluded that the drainage system of the Guaratinguetá Riverside I Neighborhood has all of the conditions and characteristics that make it suitable for the implementation of a low impact urban drainage system. Reforestation of Guaratinguetá-Piagui Peak can reduce the basin’s runoff by 50% and minimize flooding problems in the Beira Rio neighborhood.

  3. Characterization of Urban Runoff Pollution between Dissolved and Particulate Phases

    OpenAIRE

    Wei, Zhang; Simin, Li; Fengbing, Tang

    2013-01-01

    To develop urban stormwater management effectively, characterization of urban runoff pollution between dissolved and particulate phases was studied by 12 rainfall events monitored for five typical urban catchments. The average event mean concentration (AEMC) of runoff pollutants in different phases was evaluated. The AEMC values of runoff pollutants in different phases from urban roads were higher than the ones from urban roofs. The proportions of total dissolved solids, total dissolved nitr...

  4. A 3-step framework for understanding the added value of surface soil moisture measurements for large-scale runoff prediction via data assimilation - a synthetic study in the Arkansas-Red River basin

    Science.gov (United States)

    Mao, Y.; Crow, W. T.; Nijssen, B.

    2017-12-01

    Soil moisture (SM) plays an important role in runoff generation both by partitioning infiltration and surface runoff during rainfall events and by controlling the rate of subsurface flow during inter-storm periods. Therefore, more accurate SM state estimation in hydrologic models is potentially beneficial for streamflow prediction. Various previous studies have explored the potential of assimilating SM data into hydrologic models for streamflow improvement. These studies have drawn inconsistent conclusions, ranging from significantly improved runoff via SM data assimilation (DA) to limited or degraded runoff. These studies commonly treat the whole assimilation procedure as a black box without separating the contribution of each step in the procedure, making it difficult to attribute the underlying causes of runoff improvement (or the lack thereof). In this study, we decompose the overall DA process into three steps by answering the following questions (3-step framework): 1) how much can assimilation of surface SM measurements improve surface SM state in a hydrologic model? 2) how much does surface SM improvement propagate to deeper layers? 3) How much does (surface and deeper-layer) SM improvement propagate into runoff improvement? A synthetic twin experiment is carried out in the Arkansas-Red River basin ( 600,000 km2) where a synthetic "truth" run, an open-loop run (without DA) and a DA run (where synthetic surface SM measurements are assimilated) are generated. All model runs are performed at 1/8 degree resolution and over a 10-year period using the Variable Infiltration Capacity (VIC) hydrologic model at a 3-hourly time step. For the DA run, the ensemble Kalman filter (EnKF) method is applied. The updated surface and deeper-layer SM states with DA are compared to the open-loop SM to quantitatively evaluate the first two steps in the framework. To quantify the third step, a set of perfect-state runs are generated where the "true" SM states are directly inserted

  5. B cell remote-handled waste shipment cask alternatives study

    International Nuclear Information System (INIS)

    RIDDELLE, J.G.

    1999-01-01

    The decommissioning of the 324 Facility B Cell includes the onsite transport of grouted remote-handled radioactive waste from the 324 Facility to the 200 Areas for disposal. The grouted waste has been transported in the leased ATG Nuclear Services 3-82B Radioactive Waste Shipping Cask (3-82B cask). Because the 3-82B cask is a U.S. Nuclear Regulatory Commission (NRC)-certified Type B shipping cask, the lease cost is high, and the cask operations in the onsite environment may not be optimal. An alternatives study has been performed to develop cost and schedule information on alternative waste transportation systems to assist in determining which system should be used in the future. Five alternatives were identified for evaluation. These included continued lease of the 3-82B cask, fabrication of a new 3-82B cask, development and fabrication of an onsite cask, modification of the existing U.S. Department of Energy-owned cask (OH-142), and the lease of a different commercially available cask. Each alternative was compared to acceptance criteria for use in the B Cell as an initial screening. Only continued leasing of the 3-82B cask, fabrication of a new 3-82B cask, and the development and fabrication of an onsite cask were found to meet all of the B Cell acceptance criteria

  6. A GIS-based approach for identifying potential runoff harvesting sites in the Thukela River basin, South Africa

    Science.gov (United States)

    de Winnaar, G.; Jewitt, G. P. W.; Horan, M.

    Water scarce countries such as South Africa are subject to various hydrological constraints which can often be attributed to poor rainfall partitioning, particularly within resource poor farming communities that are reliant on rainfed agriculture. Recent initiatives to address this have shifted focus to explore more efficient alternatives to water supply and the recognition of numerous opportunities to implement runoff harvesting as a means to supplement water availability. However, increasing the implementation of runoff harvesting, without encountering unintended impacts on downstream hydrological and ecological systems, requires better understanding of the hydrologic and environmental impacts at catchment scale. In this paper the representation of spatial variations in landscape characteristics such as soil, land use, rainfall and slope information is shown to be an important step in identifying potential runoff harvesting sites, after which modelling the hydrological response in catchments where extensive runoff harvesting is being considered can be performed and likely impacts assessed. Geographic information systems (GIS) was utilised as an integrating tool to store, analyse and manage spatial information and when linked to hydrological response models, provided a rational means to facilitate decision making by providing catchment level identification, planning and assessment of runoff harvesting sites as illustrated by a case study at the Potshini catchment, a small sub-catchment in the Thukela River basin, South Africa. Through the linked GIS, potential runoff harvesting sites are identified relative to areas that concentrate runoff and where the stored water will be appropriately distributed. Based on GIS analysis it was found that 17% percent of the Potshini catchment area has a high potential for generating surface runoff, whereas an analysis of all factors which influence the location of such systems, shows that 18% is highly suitable for runoff

  7. Water erosion in surface soil conditions: runoff velocity, concentration and D50 index of sediments in runoff

    OpenAIRE

    Ramos,Júlio César; Bertol,Ildegardis; Barbosa,Fabrício Tondello; Bertól,Camilo; Mafra,Álvaro Luiz; Miquelluti,David José; Mecabô Júnior,José

    2016-01-01

    ABSTRACT Water erosion and contamination of water resources are influenced by concentration and diameter of sediments in runoff. This study aimed to quantify runoff velocity and concentration and the D50 index of sediments in runoff under different soil surface managements, in the following treatments: i) cropped systems: no-tilled soil covered by ryegrass (Lolium multiflorum Lam.) residue, with high soil cover and minimal roughness (HCR); no tilled soil covered by vetch (Vicia sativa L.) res...

  8. Runoff analysis by means of multiple isotope tracers in Iwami river drainage, Akita, Japan

    International Nuclear Information System (INIS)

    Matsubaya, Osamu; Yoshida, Minako; Tanaka-Miyamoto, Kiriko.

    1990-01-01

    By means of three isotope tracer techniques, proportion of direct runoff and characters of groundwater runoff were studied in the Iwami River drainage during a high runoff period for about 3 days, caused by a heavy rainfall of 85 mm for 17 hours. The proportion of direct runoff is 15 % or less of the total runoff caused by the rainfall, while 65 % of river water at the peak of runoff. Differences observed in the runoff manners among 18 O, 2 H, and 3 H are interpreted as a result of preferential runoff of previous precipitations stored in some unsaturated zone above the saturated groundwater zone. Cl - content is not conservative as a tracer to study runoff mechanisms. (author)

  9. Predicting Surface Runoff from Catchment to Large Region

    Directory of Open Access Journals (Sweden)

    Hongxia Li

    2015-01-01

    Full Text Available Predicting surface runoff from catchment to large region is a fundamental and challenging task in hydrology. This paper presents a comprehensive review for various studies conducted for improving runoff predictions from catchment to large region in the last several decades. This review summarizes the well-established methods and discusses some promising approaches from the following four research fields: (1 modeling catchment, regional and global runoff using lumped conceptual rainfall-runoff models, distributed hydrological models, and land surface models, (2 parameterizing hydrological models in ungauged catchments, (3 improving hydrological model structure, and (4 using new remote sensing precipitation data.

  10. Prediction and optimization of runoff via ANFIS and GA

    Directory of Open Access Journals (Sweden)

    D.K. Ghose

    2013-06-01

    Full Text Available In planning of water resource projects, the estimation of the availability of water plays an important role. The first step in the water availability estimation is the computation of runoff resulting from the precipitation on river catchments. The length of the runoff measured in a stream may be of short period or long period depending upon the catchment characteristics. Keeping this in mind the present work is focused on two different model generation. In the first phase of this study, runoff rating curves are developed considering present day water level (H(t as input and present day runoff (Q(t as the model output. In the second phase of the study runoff prediction models are developed considering 1 day lag water level (H(t − 1, 2 day lag water level (H(t − 2 and 1 day lag runoff (Q(t − 1 as inputs and 1 day ahead runoff (Q(t + 1 as the output of the model. Models developed and used for prediction of runoff are Non-Linear Multiple Regression (NLMR and Adaptive Neuro-Fuzzy Inference System (ANFIS. Both the models were trained and tested to predict the performance of models. Genetic Algorithm (GA is then coupled with NLMR model to obtain the condition of hydrological parameter for which the runoff is maximum.

  11. Hydro engineering Feasibility Study of Surface Runoff Water Harvesting in Al-Ajeej Basin, North West Iraq

    Directory of Open Access Journals (Sweden)

    Thair M. Al-Taiee

    2013-04-01

    Full Text Available The hydro engineering  characteristics of Al-Ajeej basin which was located within south Sinjar plain north west Iraq was analyzed to predict the possibility of surface runoff harvesting during rainfall season in the upstream sites in this basin using watershed modeling system (WMS. The hydrological feasibility of constructing small dam on Al-Ajeej valley with some preliminary design calculations were presented. The best optimum dam site was selected to be located (3.95 km downstream the confluence of Al-Badee branch with Al-Ajeej valley (35° 46¢ 6² Latitude and Longitude 41° 36¢ 11² having a catchment's area of (3043km2. The proposed dam  height was (12.5 meter with a dam length of (1277m, while the normal storage volume of the reservoir is (38.8 million m3. Construction a dams in such sites characterized by water shortage during all  around the year will give an aid in the sustainable development of such area by increasing  the cultivation lands, the agricultural products and also modify the income of the villagers living  in this area leading to prevent them leaving their lands to other places

  12. Beyond the SCS curve number: A new stochastic spatial runoff approach

    Science.gov (United States)

    Bartlett, M. S., Jr.; Parolari, A.; McDonnell, J.; Porporato, A. M.

    2015-12-01

    The Soil Conservation Service curve number (SCS-CN) method is the standard approach in practice for predicting a storm event runoff response. It is popular because its low parametric complexity and ease of use. However, the SCS-CN method does not describe the spatial variability of runoff and is restricted to certain geographic regions and land use types. Here we present a general theory for extending the SCS-CN method. Our new theory accommodates different event based models derived from alternative rainfall-runoff mechanisms or distributions of watershed variables, which are the basis of different semi-distributed models such as VIC, PDM, and TOPMODEL. We introduce a parsimonious but flexible description where runoff is initiated by a pure threshold, i.e., saturation excess, that is complemented by fill and spill runoff behavior from areas of partial saturation. To facilitate event based runoff prediction, we derive simple equations for the fraction of the runoff source areas, the probability density function (PDF) describing runoff variability, and the corresponding average runoff value (a runoff curve analogous to the SCS-CN). The benefit of the theory is that it unites the SCS-CN method, VIC, PDM, and TOPMODEL as the same model type but with different assumptions for the spatial distribution of variables and the runoff mechanism. The new multiple runoff mechanism description for the SCS-CN enables runoff prediction in geographic regions and site runoff types previously misrepresented by the traditional SCS-CN method. In addition, we show that the VIC, PDM, and TOPMODEL runoff curves may be more suitable than the SCS-CN for different conditions. Lastly, we explore predictions of sediment and nutrient transport by applying the PDF describing runoff variability within our new framework.

  13. A glacier runoff extension to the Precipitation Runoff Modeling System

    Science.gov (United States)

    Van Beusekom, Ashley E.; Viger, Roland

    2016-01-01

    A module to simulate glacier runoff, PRMSglacier, was added to PRMS (Precipitation Runoff Modeling System), a distributed-parameter, physical-process hydrological simulation code. The extension does not require extensive on-glacier measurements or computational expense but still relies on physical principles over empirical relations as much as is feasible while maintaining model usability. PRMSglacier is validated on two basins in Alaska, Wolverine, and Gulkana Glacier basin, which have been studied since 1966 and have a substantial amount of data with which to test model performance over a long period of time covering a wide range of climatic and hydrologic conditions. When error in field measurements is considered, the Nash-Sutcliffe efficiencies of streamflow are 0.87 and 0.86, the absolute bias fractions of the winter mass balance simulations are 0.10 and 0.08, and the absolute bias fractions of the summer mass balances are 0.01 and 0.03, all computed over 42 years for the Wolverine and Gulkana Glacier basins, respectively. Without taking into account measurement error, the values are still within the range achieved by the more computationally expensive codes tested over shorter time periods.

  14. Total pollution effect of urban surface runoff.

    Science.gov (United States)

    Luo, Hongbing; Luo, Lin; Huang, Gu; Liu, Ping; Li, Jingxian; Hu, Sheng; Wang, Fuxiang; Xu, Rui; Huang, Xiaoxue

    2009-01-01

    For pollution research with regard to urban surface runoff, most sampling strategies to date have focused on differences in land usage. With single land-use sampling, total surface runoff pollution effect cannot be evaluated unless every land usage spot is monitored. Through a new sampling strategy known as mixed stormwater sampling for a street community at discharge outlet adjacent to river, this study assessed the total urban surface runoff pollution effect caused by a variety of land uses and the pollutants washed off from the rain pipe system in the Futian River watershed in Shenzhen City of China. The water quality monitoring indices were COD (chemical oxygen demand), TSS (total suspend solid), TP (total phosphorus), TN (total nitrogen) and BOD (biochemical oxygen demand). The sums of total pollution loads discharged into the river for the four indices of COD, TSS, TN, and TP over all seven rainfall events were very different. The mathematical model for simulating total pollution loads was established from discharge outlet mixed stormwater sampling of total pollution loads on the basis of four parameters: rainfall intensity, total land area, impervious land area, and pervious land area. In order to treat surface runoff pollution, the values of MFF30 (mass first flush ratio) and FF30 (first 30% of runoff volume) can be considered as split-flow control criteria to obtain more effective and economical design of structural BMPs (best management practices) facilities.

  15. Selection of an appropriately simple storm runoff model

    Directory of Open Access Journals (Sweden)

    A. I. J. M. van Dijk

    2010-03-01

    Full Text Available An appropriately simple event runoff model for catchment hydrological studies was derived. The model was selected from several variants as having the optimum balance between simplicity and the ability to explain daily observations of streamflow from 260 Australian catchments (23–1902 km2. Event rainfall and runoff were estimated from the observations through a combination of baseflow separation and storm flow recession analysis, producing a storm flow recession coefficient (kQF. Various model structures with up to six free parameters were investigated, covering most of the equations applied in existing lumped catchment models. The performance of alternative structures and free parameters were expressed in Aikake's Final Prediction Error Criterion (FPEC and corresponding Nash-Sutcliffe model efficiencies (NSME for event runoff totals. For each model variant, the number of free parameters was reduced in steps based on calculated parameter sensitivity. The resulting optimal model structure had two or three free parameters; the first describing the non-linear relationship between event rainfall and runoff (Smax, the second relating runoff to antecedent groundwater storage (CSg, and a third that described initial rainfall losses (Li, but which could be set at 8 mm without affecting model performance too much. The best three parameter model produced a median NSME of 0.64 and outperformed, for example, the Soil Conservation Service Curve Number technique (median NSME 0.30–0.41. Parameter estimation in ungauged catchments is likely to be challenging: 64% of the variance in kQF among stations could be explained by catchment climate indicators and spatial correlation, but corresponding numbers were a modest 45% for CSg, 21% for Smax and none for Li, respectively. In gauged catchments, better

  16. Adaptive measurements of urban runoff quality

    Science.gov (United States)

    Wong, Brandon P.; Kerkez, Branko

    2016-11-01

    An approach to adaptively measure runoff water quality dynamics is introduced, focusing specifically on characterizing the timing and magnitude of urban pollutographs. Rather than relying on a static schedule or flow-weighted sampling, which can miss important water quality dynamics if parameterized inadequately, novel Internet-enabled sensor nodes are used to autonomously adapt their measurement frequency to real-time weather forecasts and hydrologic conditions. This dynamic approach has the potential to significantly improve the use of constrained experimental resources, such as automated grab samplers, which continue to provide a strong alternative to sampling water quality dynamics when in situ sensors are not available. Compared to conventional flow-weighted or time-weighted sampling schemes, which rely on preset thresholds, a major benefit of the approach is the ability to dynamically adapt to features of an underlying hydrologic signal. A 28 km2 urban watershed was studied to characterize concentrations of total suspended solids (TSS) and total phosphorus. Water quality samples were autonomously triggered in response to features in the underlying hydrograph and real-time weather forecasts. The study watershed did not exhibit a strong first flush and intraevent concentration variability was driven by flow acceleration, wherein the largest loadings of TSS and total phosphorus corresponded with the steepest rising limbs of the storm hydrograph. The scalability of the proposed method is discussed in the context of larger sensor network deployments, as well the potential to improving control of urban water quality.

  17. Variations of annual and seasonal runoff in Guangdong Province, south China: spatiotemporal patterns and possible causes

    Science.gov (United States)

    Zhang, Qiang; Xiao, Mingzhong; Singh, Vijay P.; Xu, Chong-Yu; Li, Jianfeng

    2015-06-01

    In this study, we thoroughly analyzed spatial and temporal distributions of runoff and their relation with precipitation changes based on monthly runoff dataset at 25 hydrological stations and monthly precipitation at 127 stations in Guangdong Province, south China. Trends of the runoff and precipitation are detected using Mann-Kendall trend test technique. Correlations between runoff and precipitation are tested using Spearman's and Pearson's correlation coefficients. The results indicate that: (1) annual maximum monthly runoff is mainly in decreasing tendency and significant increasing annual minimum monthly runoff is observed in the northern and eastern Guangdong Province. In addition, annual mean runoff is observed to be increasing at the stations located in the West and North Rivers and the coastal region; (2) analysis of seasonal runoff variations indicates increasing runoff in spring, autumn and winter. Wherein, significant increase of runoff is found at 8 stations and only 3 stations are dominated by decreasing runoff in winter; (3) runoff changes of the Guangdong Province are mainly the results of precipitation changes. The Guangdong Province is wetter in winter, spring and autumn. Summer is coming to be drier as reflected by decreasing runoff in the season; (4) both precipitation change and water reservoirs also play important roles in the increasing of annual minimum monthly streamflow. Seasonal shifts of runoff variations may pose new challenges for the water resources management under the influences of climate changes and intensifying human activities.

  18. Effects of Intra-Storm Soil Moisture and Runoff Characteristics on Ephemeral Gully Development: Evidence from a No-Till Field Study

    Directory of Open Access Journals (Sweden)

    Vladimir R. Karimov

    2017-09-01

    Full Text Available Ephemeral gully erosion, prevalent on agricultural landscapes of the Great Plains, is recognized as a large source of soil loss and a substantial contributor to the sedimentation of small ponds and large reservoirs. Multi-seasonal field studies can provide needed information on ephemeral gully development and its relationship to physical factors associated with field characteristics, rainfall patterns, runoff hydrograph, and management practices. In this study, an ephemeral gully on a no-till cultivated crop field in central Kansas, U.S., was monitored in 2013 and 2014. Data collection included continuous sub-hourly precipitation, soil moisture, soil temperature, and 15 field surveys of cross-sectional profiles in the headcut and channelized parts of the gully. Rainfall excess from a contributing catchment was calculated with the Water Erosion Prediction Project (WEPP model for all storm events and validated on channel flow measurements. Twelve significant runoff events with hydraulic shear stresses higher than the critical value were identified to potentially cause soil erosion in three out of fourteen survey periods. Analysis of shear stress imposed by peak channel flow on soil surface, antecedent soil moisture condition, and channel shape at individual events provided the basis on which to extend the definition of the critical shear stress function by incorporating the intra-storm changes in soil moisture content. One potential form of this function was suggested and tested with collected data. Similar field studies in other agriculturally-dominated areas and laboratory experiments can develop datasets for a better understanding of the physical mechanisms associated with ephemeral gully progression.

  19. Is proglacial field an important contributor to runoff in glacierized watershed? Lesson learned from a case study in Duke River watershed, Yukon, Canada.

    Science.gov (United States)

    Chesnokova, A.; Baraer, M.

    2017-12-01

    Sub-Arctic glacierized catchments are complex hydrological systems of paramount importance not only for water resources management but also for various ecosystem services. Those areas are environmentally fragile and host many climate-sensitive components of hydrological cycle. In a context of shifting from glacial to non-glacial regimes in Sub-Arctic, this study focuses on understanding hydrological role of proglacial field in runoff generation in headwaters of Duke River watershed, Canada, by comparing to that of alpine meadow (area that is not recently reworked by glacier). Duke Glacier, as many glaciers in St. Elias Mountains, is a surging glacier, and produced debris-charged dead-ice masses once the last surge has seized. In addition, such features as ice-cored moraines and taluses are found in proglacial field. Those features are hypothesised to cause high storage capacity and complex groundwater distribution systems which might affect significantly watershed hydrology. In order to estimate the contribution of different components of the alpine meadow and the proglacial field to runoff, HBCM, a multi-component distributed hydrochemical mixing model (Baraer et al., 2015) was applied. During field campaign in June 2016, 157 samples were taken from possible hydrological sources (end-members) and from main stream, and analysed for major ions, dissolved organic compounds and heavy stable water isotopes. End-members contribution was quantified based on tracer concentration at mixing points. Discharge was measured 6 km downstream from the glacier snout so that both proglacial field and alpine meadow occupy comparable areas of the catchment. Results show the difference between main water sources for the two hydrological systems: buried ice, ice-cored moraines and groundwater sources within proglacial field, and groundwater and supra-permafrost water within alpine meadow. Overall contribution of glaciers during June 2016 exceeded the contribution of the rest of the

  20. From a microcosm to the catchment scale: studying the fate of organic runoff pollutants in aquatic ecosystems

    Science.gov (United States)

    Böttcher, T.; Schroll, R.

    2009-04-01

    Spray-drift, drainage, erosion and runoff events are the major causes responsible for deportation of agrochemicals as micropollutants to aquatic non-target sites. These processes can lead to the contamination of nearby freshwater ecosystems with considerably high concentrations of xenobiotics. Thus, it is important to unravel the fate of these pollutants and to evaluate their ecological effects. A novel approach to address this goal was established by the development of a microcosm with multiple sampling abilities enabling quantitative assessment of organic volatilisation, mineralization, metabolization and distribution within the aquatic ecosystem. This microcosm system was designed to support modelling approaches of the catchment scale and gain insights into the fate of pesticides simulating a large scale water body. The potential of this microcosm was exemplified for Isoproturon (IPU), a phenylurea derived systemic herbicide, which is frequently found as contaminant in water samples and with the free-floating macrophyte Lemna minor as non-target species, that is common to occur in rural water bodies. During 21 days exposure time, only a small amount of 14C labeled IPU was removed from the aquatic medium. The major portion (about 5%) was accumulated by Lemna minor resulting in a BCF of 15.8. IPU-volatilisation was very low with 0.13% of the initially applied herbicide. Only a minor amount of IPU was completely metabolized, presumably by rhizosphere microorganisms and released as 14CO2. The novel experimental system allowed to quantitatively investigate the fate of IPU and showed a high reproducibility with a mean average 14C-recovery rate of 97.1

  1. Characterization of chromium species in urban runoff

    DEFF Research Database (Denmark)

    Cederkvist, Karin; Jensen, Marina Bergen; Holm, Peter Engelund

    2013-01-01

    Little is known about the presence of the element Cr in its toxic hexavalent form Cr(VI) in stormwater runoff from urban areas. Most studies report only total Cr concentration, i.e., including also the nontoxic Cr(III) molecular form. The objective of this study was to evaluate a field method bas...

  2. A glacier runoff extension to the Precipitation Runoff Modeling System

    Science.gov (United States)

    A. E. Van Beusekom; R. J. Viger

    2016-01-01

    A module to simulate glacier runoff, PRMSglacier, was added to PRMS (Precipitation Runoff Modeling System), a distributed-parameter, physical-process hydrological simulation code. The extension does not require extensive on-glacier measurements or computational expense but still relies on physical principles over empirical relations as much as is feasible while...

  3. Estimating runoff from ungauged catchments for reservoir water ...

    African Journals Online (AJOL)

    The Lower Middle Zambezi Basin is sandwiched between three hydropower ... This study applied a rainfall-runoff model (HEC-HMS) and GIS techniques to ... Missing data were generated using the mean value infilling method. ... A hydrological model, HEC- HMS, was used to simulate runoff from the ungauged catchments.

  4. Variation of runoff source areas under different soil wetness ...

    African Journals Online (AJOL)

    Runoff source areas can serve as focus areas for water quality monitoring and catchment management. In this study, a conceptual form of the Soil Conservation Service Curve Number method (SCS-CN) is used to define variable-source runoff areas in a meso-scale catchment in the Zagros mountain region, southwest of ...

  5. Quantifying rainfall-runoff relationships on the Mieso Hypo Calcic ...

    African Journals Online (AJOL)

    The mean annual rainfall at Mieso is 738 mm. The soil is a Hypo Calcic Vertisol with a high clay and silt content and is very susceptible to crusting. To achieve the objective of the study, rainfall-runoff measurements were made during 2003 and 2004 on 2 m x 2 m plots provided with a runoff measuring system, and replicated ...

  6. Cropland filter strip removal of cattle manure constituents in runoff

    Science.gov (United States)

    There is little scientifically-derived information available to help identify setback distances required to effectively reduce contaminants from incoming runoff on cropland areas. The objective of this study was to determine the effects of cropland filter strip (CFS) length and runoff rate on concen...

  7. RAINWATER MANAGEMENT AIMING TO IMPROVE THE QUALITY OF URBAN SURFACE RUNOFF

    Directory of Open Access Journals (Sweden)

    I. HAIDU

    2015-10-01

    Full Text Available Rainwater Management Aiming to Improve the Quality of Urban Surface Runoff. Currently many urban areas experience the quality degradation of rooftop runoff and accumulated rainwater. The present study aims to estimate the volume of water draining from rooftops within an area of 0.68 km² in the municipality of Cluj-Napoca. The volume of water flowing from rooftops presents a beneficial alternative not only for collecting rainwater for later use, but also for reducing the volume of water and for improving surface runoff quality in urban areas. The procedure was based on the Michel Simplified SCS-CN model, a derived variant of the most popular hydrological model, the Soil Conservation Service Curve Number (SCS-CN. The results of the applied method reveal that the highest rooftop runoff water values correspond to the summer months, these being based on daily rainfall data. Estimating the volume of water draining from rooftops for future harvesting is an important step in the sustainable management of rainwater in urban areas and in improving water quality.

  8. Effects of tillage on runoff from a bare clayey soil on a semi-arid ...

    African Journals Online (AJOL)

    arid areas. However, by adopting appropriate soil management practices, the runoff can be harnessed for improving crop yields. The main objective of this study was to quantify rainfall-runoff relationships under in-field rainwater harvesting ...

  9. Variation of Runoff and Precipitation in the Hekou-Longmen Region of the Yellow River Based on Elasticity Analysis

    OpenAIRE

    Li, Erhui; Mu, Xingmin; Zhao, Guangju; Gao, Peng; Shao, Hongbo

    2014-01-01

    Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution of precipitation to runoff change in the Hekou-Longmen region (from 1957 to 2010), Huangfuchuan wat...

  10. Satellite-derived land covers for runoff estimation using SCS-CN method in Chen-You-Lan Watershed, Taiwan

    Science.gov (United States)

    Zhang, Wen-Yan; Lin, Chao-Yuan

    2017-04-01

    The Soil Conservation Service Curve Number (SCS-CN) method, which was originally developed by the USDA Natural Resources Conservation Service, is widely used to estimate direct runoff volume from rainfall. The runoff Curve Number (CN) parameter is based on the hydrologic soil group and land use factors. In Taiwan, the national land use maps were interpreted from aerial photos in 1995 and 2008. Rapid updating of post-disaster land use map is limited due to the high cost of production, so the classification of satellite images is the alternative method to obtain the land use map. In this study, Normalized Difference Vegetation Index (NDVI) in Chen-You-Lan Watershed was derived from dry and wet season of Landsat imageries during 2003 - 2008. Land covers were interpreted from mean value and standard deviation of NDVI and were categorized into 4 groups i.e. forest, grassland, agriculture and bare land. Then, the runoff volume of typhoon events during 2005 - 2009 were estimated using SCS-CN method and verified with the measured runoff data. The result showed that the model efficiency coefficient is 90.77%. Therefore, estimating runoff by using the land cover map classified from satellite images is practicable.

  11. Does runoff or temperature control chemical weathering rates?

    International Nuclear Information System (INIS)

    Eiriksdottir, Eydis Salome; Gislason, Sigurdur Reynir; Oelkers, Eric H.

    2011-01-01

    Highlights: → The rate chemical weathering is affected by both temperature and runoff. Separating out these two factors is challenging because runoff tends to increase with increasing temperature. → In this study, natural river water samples collected on basaltic catchments over a five year period are used together with experimentally derived dissolution rate model for basaltic glass to pull apart the effects of runoff and temperature. → This study shows that the rate of chemical denudation is controlled by both temperature and runoff, but is dominated by runoff. - Abstract: The rate of chemical denudation is controlled by both temperature and runoff. The relative role of these two factors in the rivers of NE Iceland is determined through the rigorous analysis of their water chemistry over a 5-a period. River catchments are taken to be analogous to laboratory flow reactors; like the fluid in flow reactors, the loss of each dissolved element in river water is the sum of that of the original rainwater plus that added from kinetically controlled dissolution and precipitation reactions. Consideration of the laboratory determined dissolution rate behaviour of basalts and measured water chemistry indicates that the maximum effect of changing temperature on chemical denudation in the NE Icelandic rivers was 5-25% of the total change, whereas that of runoff was 75-95%. The bulk of the increased denudation rates with runoff appear to stem from an increase in reactive surface area for chemical weathering of catchment solids.

  12. Evaluation of hybrid power system alternatives: a case study

    International Nuclear Information System (INIS)

    Rosenthal, Andrew L.

    1999-01-01

    Pursuant to executive and statutory policies, the National Park Service (NPS) has been evaluating the use of photovoltaic (PV) hybrid power systems, for many of its remote, off-grid areas. This paper reports the results of a detailed technical and economic evaluation for one such area: the Needles District of Canyonlands National Park. The study evaluates the presented power systems and five alternative power generation configurations, four of which utilise PV. Projections are provided for the generator run-time and fuel use associated with each configuration as well as all initial and future costs. Included in the study are specific recommendations for energy efficiency improvements at the site. Results show that the generation systems presently in use, two full-time diesel generators, has the lowest conventional 20-year life cycle costs (LCC) of the six systems evaluated. However, when emissions costs are included (per NPS guidelines), several of the PV hybrid alternatives attain a lower LCC than the diesel-only systems. General discussion of the effects of initial versus future costs of PV hybrids as they compare with engine generator system is presented. (Author)

  13. Runoff and Sediment Yield Variations in Response to Precipitation Changes: A Case Study of Xichuan Watershed in the Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    Tianhong Li

    2015-10-01

    Full Text Available The impacts of climate change on hydrological cycles and water resource distribution is particularly concerned with environmentally vulnerable areas, such as the Loess Plateau, where precipitation scarcity leads to or intensifies serious water related problems including water resource shortages, land degradation, and serious soil erosion. Based on a geographical information system (GIS, and using gauged hydrological data from 2001 to 2010, digital land-use and soil maps from 2005, a Soil and Water Assessment Tool (SWAT model was applied to the Xichuan Watershed, a typical hilly-gullied area in the Loess Plateau, China. The relative error, coefficient of determination, and Nash-Sutcliffe coefficient were used to analyze the accuracy of runoffs and sediment yields simulated by the model. Runoff and sediment yield variations were analyzed under different precipitation scenarios. The increases in runoff and sediment with increased precipitation were greater than their decreases with reduced precipitation, and runoff was more sensitive to the variations of precipitation than was sediment yield. The coefficients of variation (CVs of the runoff and sediment yield increased with increasing precipitation, and the CV of the sediment yield was more sensitive to small rainfall. The annual runoff and sediment yield fluctuated greatly, and their variation ranges and CVs were large when precipitation increased by 20%. The results provide local decision makers with scientific references for water resource utilization and soil and water conservation.

  14. Responses of Surface Runoff to Climate Change and Human Activities in the Arid Region of Central Asia: A Case Study in the Tarim River Basin, China

    Science.gov (United States)

    Xu, Changchun; Chen, Yaning; Chen, Yapeng; Zhao, Ruifeng; Ding, Hui

    2013-04-01

    Based on hydrological and climatic data and land use/cover change data covering the period from 1957 to 2009, this paper investigates the hydrological responses to climate change and to human activities in the arid Tarim River basin (TRB). The results show that the surface runoff of three headstreams (Aksu River, Yarkant River and Hotan River) of the Tarim River exhibited a significant increasing trend since 1960s and entered an even higher-runoff stage in 1994. In the contrary, the surface runoff of Tarim mainstream displayed a persistent decreasing trend since 1960s. The increasing trend of surface runoff in the headstreams can be attributed to the combined effects of both temperature and precipitation changes during the past five decades. But, the decreasing trend of surface runoff in the mainstream and the observed alterations of the temporal and spatial distribution patterns were mainly due to the adverse impacts of human activities. Specifically, increasingly intensified water consumption for irrigation and the associated massive constructions of water conservancy projects were responsible for the decreasing trend of runoff in the mainstream. And, the decreasing trend has been severely jeopardizing the ecological security in the lower reaches. It is now unequivocally clear that water-use conflicts among different sectors and water-use competitions between upper and lower reaches are approaching to dangerous levels in TRB that is thus crying for implementing an integrated river basin management scheme.

  15. Runoff velocity behaviour on smooth pavement and paving blocks surfaces measured by a tilted plot

    Directory of Open Access Journals (Sweden)

    Sedyowati Laksni

    2017-06-01

    Full Text Available Paving blocks have been widely known as an alternative technology for reducing runoff discharge due to their infiltration performance and capability of retarding the flow. Surface configuration of the different paving blocks types and the openings area play important role in decreasing the runoff velocity. In this study, we investigated the surface runoff velocity on two types of paving blocks layers, and a smooth pavement as comparison. The paving blocks type were rectangular blocks, which have 3.2% openings ratio and hexagonal blocks, which have 6.5% openings ratio. We used a tilted plot covering area of 2 × 6 m, equipped by a rainfall simulator to accommodate the variation of surface slope and rainfall intensity. We measured the velocity by using modification of dye tracer and buoyancy method. The data were then tabulated and graphed based on the paving types and the surface slopes. Generally, the velocity-slope relationship has demonstrated that the increase in surface slope leads to the increase in velocity. In this study, the result showed that slope and rainfall intensity simultaneously influenced the velocity (F = 19.91 > Ftable = 5.14; P < 0.05. However, the findings of this study showed a weak relationship between the changes of surface slope and the changes of runoff velocity on the rectangular blocks (R2 = 0.38. The greater slope did not always invariably lead to the greater runoff velocity. It was likely that there was other predictor variable that was not identified before, and need to be further investigated.

  16. Alternation learning in pathological gamblers: an fMRI Study.

    Science.gov (United States)

    Dannon, Pinhas N; Kushnir, Tammar; Aizer, Anat; Gross-Isseroff, Ruth; Kotler, Moshe; Manor, David

    2011-03-01

    We have previously reported that pathological gamblers have impaired performance on the Stroop color word naming task, go-no-go task and speed accuracy tradeoff performance, tasks used to assess executive function and interference control. The aim of the present neuroimaging study was to explore the relationship between frontal cortex function and gambling severity in pathological gamblers. Functional MRI (fMRI) was used to estimate brain activity of ten male medication-free pathological gamblers during performance of an alternation learning task. Performance of this task has been shown to depend on the function of regions in the frontal cortex. The executive functions needed to perform the alternation learning task were expressed as brain activation in lateral and medial frontal as well as parietal and occipital regions. By correlating the level of local brain activation to task performance, parietal regions and lateral frontal and orbitofrontal regions were demonstrated. A higher score in SOGS was associated with intrusion on the task-specific activation in the left hemisphere, to some extant in parietal regions and even more pronouncedly in left frontal and orbitofrontal regions. Our preliminary data suggests that pathological gambling may be characterized by specific neuro-cognitive changes related to the frontal cortex.

  17. Digital radiography: study of an alternative technique to conventional radiography

    International Nuclear Information System (INIS)

    Banchet, J.; Tisseur, D.; Thomas, A.

    2009-01-01

    Digital radiography, already in use in many industrial applications, appears as a potential alternative technique to conventional radiography in the nuclear field (and more especially to the inspection of welded joints). The advantages of digital radiography are a reduced explosion risk (due to the use of lower energy and activity sources), a lower installation time, a reduced exclusion zone, and the absence of effluents. However, to the contrary of the US case, this technique may not be used in France as it is not referenced in the regulating codes (RCCM, etc.). Areva has launched a R and D study in order to characterize the equivalencies between digital and conventional radiography. First results of this study are given

  18. Contaminants in urban runoff to Norwegian fjords

    Energy Technology Data Exchange (ETDEWEB)

    Jartun, Morten [Geological Survey of Norway, Trondheim (Norway); Pettersen, Arne [Norwegian Geotechnical Inst., Oslo (Norway)

    2010-03-15

    Introduction: Sediments from urban stormwater runoff have been collected and analyzed for the content of various contaminants in harbor areas of Harstad, Trondheim, Bergen, and Drammen, Norway. Materials and methods: The concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), tributyltin, heavy metals, and total organic carbon were determined in most samples. This study provides substantial empirical data on the active, ongoing dispersion of pollutants from land-based sources in an urban area toward the marine environments in Norway. Results and discussion: The results of the analyses clearly demonstrate the importance of the urban environment representing a variety of contamination sources, and that stormwater runoff is an important dispersion mechanism of toxic pollutants. Conclusion: The concentrations of different contaminants in the urban runoff sediments show that there are several active pollution sources supplying the runoff systems with PCBs, PAHs (including benzo(a)pyrene, B(a)p), and heavy metals such as lead, mercury, zinc, and cadmium. This study describe the usefulness of the methods on how to examine ongoing urban contamination of harbors and similar recipients before any remediation plan for improving the environmental condition of marine sediments is effectuated. (orig.)

  19. Prediction of hydrological reduction factor and initial loss in urban surface runoff from small ungauged catchments

    DEFF Research Database (Denmark)

    Arnbjerg-Nielsen, K.; Harremoës, P.

    1996-01-01

    An advanced runoff model is compared to a simple one employing only a runoff coefficient and a regression parameter allowing for initial loss. The present study shows that the more detailed description of the runoff processes cannot be justified due to the uncertainty from using only one gauge...... in the evaluation of the yearly discharges. In the case of extreme events, the uncertainty of the predicted runoff of the single event should also be taken into account....

  20. How runoff begins (and ends): characterizing hydrologic response at the catchment scale

    Science.gov (United States)

    Mirus, Benjamin B.; Loague, Keith

    2013-01-01

    Improved understanding of the complex dynamics associated with spatially and temporally variable runoff response is needed to better understand the hydrology component of interdisciplinary problems. The objective of this study was to quantitatively characterize the environmental controls on runoff generation for the range of different streamflow-generation mechanisms illustrated in the classic Dunne diagram. The comprehensive physics-based model of coupled surface-subsurface flow, InHM, is employed in a heuristic mode. InHM has been employed previously to successfully simulate the observed hydrologic response at four diverse, well-characterized catchments, which provides the foundation for this study. The C3 and CB catchments are located within steep, forested terrain; the TW and R5 catchments are located in gently sloping rangeland. The InHM boundary-value problems for these four catchments provide the corner-stones for alternative simulation scenarios designed to address the question of how runoff begins (and ends). Simulated rainfall-runoff events are used to systematically explore the impact of soil-hydraulic properties and rainfall characteristics. This approach facilitates quantitative analysis of both integrated and distributed hydrologic responses at high-spatial and temporal resolution over the wide range of environmental conditions represented by the four catchments. The results from 140 unique simulation scenarios illustrate how rainfall intensity/depth, subsurface permeability contrasts, characteristic curve shapes, and topography provide important controls on the hydrologic-response dynamics. The processes by which runoff begins (and ends) are shown, in large part, to be defined by the relative rates of rainfall, infiltration, lateral flow convergence, and storage dynamics within the variably saturated soil layers.

  1. An alternative approach for socio-hydrology: case study research

    Science.gov (United States)

    Mostert, Erik

    2018-01-01

    Currently the most popular approach in socio hydrology is to develop coupled human-water models. This article proposes an alternative approach, qualitative case study research, involving a systematic review of (1) the human activities affecting the hydrology in the case, (2) the main human actors, and (3) the main factors influencing the actors and their activities. Moreover, this article presents a case study of the Dommel Basin in Belgium and the Netherlands, and compares this with a coupled model of the Kissimmee Basin in Florida. In both basins a pendulum swing from water resources development and control to protection and restoration can be observed. The Dommel case study moreover points to the importance of institutional and financial arrangements, community values, and broader social, economic, and technical developments. These factors are missing from the Kissimmee model. Generally, case studies can result in a more complete understanding of individual cases than coupled models, and if the cases are selected carefully and compared with previous studies, it is possible to generalize on the basis of them. Case studies also offer more levers for management and facilitate interdisciplinary cooperation. Coupled models, on the other hand, can be used to generate possible explanations of past developments and quantitative scenarios for future developments. The article concludes that, given the limited attention they currently get and their potential benefits, case studies deserve more attention in socio-hydrology.

  2. Precipitation and runoff water quality from an urban parking lot and implications for tree growth

    Science.gov (United States)

    C. H. Pham; H. G. Halverson; G. M. Heisler

    1978-01-01

    The water quality of precipitation and runoff from a large parking lot in New Brunswick, New Jersey was studied during the early growing season, from March to June 1976. Precipitation and runoff from 10 storms were analyzed. The runoff was higher in all constituents considered except for P, Pb, and Cu. Compared with published values for natural waters, sewage effluent...

  3. Investigating the Influence of Various Stormwater Runoff Control Facilities on Runoff Control Efficiency in a Small Catchment Area

    Directory of Open Access Journals (Sweden)

    Rei Itsukushima

    2018-02-01

    Full Text Available Urbanization causes an increase in the flood discharge because of the infiltration capacity. Furthermore, extreme precipitation events have been an increasing concern for many regions worldwide. This study aimed to investigate the influence of different outflow control facilities on runoff reduction in a small watershed. We focused on the soil-improvement technology and rainwater tanks as outflow control facilities and conducted a runoff calculation using a rainfall event of a magnitude that is likely to occur once in a hundred years. The calculation showed that the soil-improvement technology reduced runoff during long-term continuous rainfall, whereas in a concentrated short-term rainfall event, a significant difference in the runoff reduction effect between rainfall tanks of various volumes was observed. Since effective countermeasures for runoff reduction differ depending on the rainfall distribution pattern, we suggested both facilities for storing initial rainfall and initiating countermeasures for penetration improvement over the long term.

  4. Engineering evaluation/cost analysis: Waste Pit Area storm water runoff control, Feed Materials Production Center, Fernald, Ohio

    International Nuclear Information System (INIS)

    1990-08-01

    This report evaluates remedial action alternatives at the Feed Materials production Center in response to the need to contain contaminated storm water runoff. The storm water is being contaminated as it falls over a radioactive/chemical waste pit which contains uranium contaminated wastes. Alternatives considered include no action, surface capping, surface capping with lateral drainage, runoff collection and treatment, and source removal

  5. Detecting surface runoff location in a small catchment using distributed and simple observation method

    Science.gov (United States)

    Dehotin, Judicaël; Breil, Pascal; Braud, Isabelle; de Lavenne, Alban; Lagouy, Mickaël; Sarrazin, Benoît

    2015-06-01

    Surface runoff is one of the hydrological processes involved in floods, pollution transfer, soil erosion and mudslide. Many models allow the simulation and the mapping of surface runoff and erosion hazards. Field observations of this hydrological process are not common although they are crucial to evaluate surface runoff models and to investigate or assess different kinds of hazards linked to this process. In this study, a simple field monitoring network is implemented to assess the relevance of a surface runoff susceptibility mapping method. The network is based on spatially distributed observations (nine different locations in the catchment) of soil water content and rainfall events. These data are analyzed to determine if surface runoff occurs. Two surface runoff mechanisms are considered: surface runoff by saturation of the soil surface horizon and surface runoff by infiltration excess (also called hortonian runoff). The monitoring strategy includes continuous records of soil surface water content and rainfall with a 5 min time step. Soil infiltration capacity time series are calculated using field soil water content and in situ measurements of soil hydraulic conductivity. Comparison of soil infiltration capacity and rainfall intensity time series allows detecting the occurrence of surface runoff by infiltration-excess. Comparison of surface soil water content with saturated water content values allows detecting the occurrence of surface runoff by saturation of the soil surface horizon. Automatic records were complemented with direct field observations of surface runoff in the experimental catchment after each significant rainfall event. The presented observation method allows the identification of fast and short-lived surface runoff processes at a small spatial and temporal resolution in natural conditions. The results also highlight the relationship between surface runoff and factors usually integrated in surface runoff mapping such as topography, rainfall

  6. Variability of Measured Runoff and Soil Loss from Field Plots

    Directory of Open Access Journals (Sweden)

    F. Asadzadeh

    2016-02-01

    Full Text Available Introduction: Field plots are widely used in studies related to the measurements of soil loss and modeling of erosion processes. Research efforts are needed to investigate factors affecting the data quality of plots. Spatial scale or size of plots is one of these factors which directly affects measuring runoff and soil loss by means of field plots. The effect of plot size on measured runoff or soil loss from natural plots is known as plot scale effect. On the other hand, variability of runoff and sediment yield from replicated filed plots is a main source of uncertainty in measurement of erosion from plots which should be considered in plot data interpretation processes. Therefore, there is a demand for knowledge of soil erosion processes occurring in plots of different sizes and of factors that determine natural variability, as a basis for obtaining soil loss data of good quality. This study was carried out to investigate the combined effects of these two factors by measurement of runoff and soil loss from replicated plots with different sizes. Materials and Methods: In order to evaluate the variability of runoff and soil loss data seven plots, differing in width and length, were constructed in a uniform slope of 9% at three replicates at Koohin Research Station in Qazvin province. The plots were ploughed up to down slope in September 2011. Each plot was isolated using soil beds with a height of 30 cm, to direct generated surface runoff to the lower part of the plots. Runoff collecting systems composed of gutters, pipes and tankswere installed at the end of each plot. During the two-year study period of 2011-2012, plots were maintained in bare conditions and runoff and soil loss were measured for each single event. Precipitation amounts and characteristics were directly measured by an automatic recording tipping-bucket rain gauge located about 200 m from the experimental plots. The entire runoff volume including eroded sediment was measured on

  7. The study, design and simulation of a free piston Stirling engine linear alternatorThe study, design and simulation of a free piston Stirling engine linear alternator

    Directory of Open Access Journals (Sweden)

    Teodora Susana Oros

    2014-12-01

    Full Text Available This paper presents a study, design and simulation of a Free Piston Stirling Engine Linear Alternator. There are presented the main steps of the magnetic and electric calculations for a permanent magnet linear alternator of fixed coil and moving magnets type. Finally, a detailed thermal, mechanical and electrical model for a Stirling engine linear alternator have been made in SIMULINK simulation program. The linear alternator simulation model uses a controllable DC voltage which simulates the linear alternator combined with a rectifier, a variable load and a DC-DC converter, which compensates for the variable nature of Stirling engine operation, and ensures a constant voltage output regardless of the load.

  8. Surface runoff in the Itaim Watershed

    Directory of Open Access Journals (Sweden)

    Getulio Teixeira Batista

    2007-06-01

    Full Text Available This paper describes a work done in the Itaim watershed at Taubaté, SP, and had the objective of estimating the surface runoff based on the Curve-Number (CN method in area with vegetation cover of grassland (Brachiaria Decumbens, that prevails in this watershed. The surface runoff was estimated using three different methods: 1st values of accumulated Infiltration (IAc obtained in the field were used, considered as the Potential Infiltration (S, which varied from 15.37 mm to 51.88 mm with an average value of 23.46 mm. With those measured infiltration rates and using the maximum precipitation values for Taubaté, SP, with duration time of 3 hours: P = 54.4; 70.3; 80.8; 86.7; 90.9; 94.1 and 103.9 mm, respectively, for the return times, Tr = 2, 5, 10, 15, 25, 50 and 100 years, the following values of surface runoff were generated: 34.83; 49.33; 59.14; 64.71; 68.69; 71.73 and 81.10 mm, respectively; In the 2nd method it was considered that the prevailing vegetation cover of the watershed was Dirty Pasture (Pasture with regrowth of natural vegetation and therefore, a value of CN = 75 was used and generated a potential infiltration, S = 84,7 mm and resulted in surface runoff values that varied from 11 to 44 mm; In the 3rd method, the value of CN was considered equal to 66.57. This value was calculated weighting the contribution of all land use cover classes of the watershed, and as a result a higher value of potential infiltration, S = 127 mm, was obtained. Consequently, the surface runoff values were 5.33; 11.64; 16.72; 19.83; 22.16; 23.98 and 29.83 mm, respectively. Therefore, the comparison with the results obtained by the two Curve-Number methods (conventional and weighted allowed to be concluded that the Curve-Number method applied in a conventional way underestimated the surface runoff in the studied area. However, results indicate that it is possible to use this method for surface runoff estimates as long as adjustments based on potential

  9. Climatic Models Ensemble-based Mid-21st Century Runoff Projections: A Bayesian Framework

    Science.gov (United States)

    Achieng, K. O.; Zhu, J.

    2017-12-01

    There are a number of North American Regional Climate Change Assessment Program (NARCCAP) climatic models that have been used to project surface runoff in the mid-21st century. Statistical model selection techniques are often used to select the model that best fits data. However, model selection techniques often lead to different conclusions. In this study, ten models are averaged in Bayesian paradigm to project runoff. Bayesian Model Averaging (BMA) is used to project and identify effect of model uncertainty on future runoff projections. Baseflow separation - a two-digital filter which is also called Eckhardt filter - is used to separate USGS streamflow (total runoff) into two components: baseflow and surface runoff. We use this surface runoff as the a priori runoff when conducting BMA of runoff simulated from the ten RCM models. The primary objective of this study is to evaluate how well RCM multi-model ensembles simulate surface runoff, in a Bayesian framework. Specifically, we investigate and discuss the following questions: How well do ten RCM models ensemble jointly simulate surface runoff by averaging over all the models using BMA, given a priori surface runoff? What are the effects of model uncertainty on surface runoff simulation?

  10. Techno-economic study of different alternatives for biodiesel production

    International Nuclear Information System (INIS)

    Marchetti, J.M.; Miguel, V.U.; Errazu, A.F.

    2008-01-01

    Biodiesel has become an attractive diesel fuel substitute due to its environmental benefits since it can be made from renewable resource. However, the high costs surrounding biodiesel production remains the main problem in making it competitive in the fuel market either as a blend or as a neat fuel. More than 80% of the production cost is associated with the feedstock itself and consequently, efforts are focused on developing technologies capable of using lower-cost feedstocks, such as recycled cooking oils and wastes from animal or vegetable oil processing operations. The main issue with spent oils is the high level of free fatty acids found in the recycled materials. The conventional technology employs sodium methoxide as a homogeneous base catalyst for the transesterification reaction and illustrates the drawbacks in working with feedstocks that contain high levels of free fatty acids. On the other hand, homogeneous acidic catalysts are being used for exactly such feedstocks. Both acid and basic homogeneous catalyzed processes require downstream purification equipment to neutralize the catalyst and to purify the biodiesel as well as the glycerol. Recent studies have been conducted to employ heterogeneous catalysts, such acidic or basic solid resins, or immobilized lipases. These catalysts will allow the use of different feedstocks that will permit operation at lower investment costs and will require less downstream process equipment. A conceptual design of these alternative production plants has been done with a techno-economic analysis in order to compare these alternatives. A process simulator was employed to carry out the conceptual design and simulation of each technology. Using these models it was possible to analyze different scenarios and to evaluate productivity, raw material consumption, economic competitiveness, and environmental impacts of each process. (author)

  11. Integrating alternative providers into managed care: a case study.

    Science.gov (United States)

    Broida, M

    1997-09-01

    Alternative medical techniques have become extremely popular, particularly in the western United States. Washington State recently enacted a law requiring certain health plans to include alternative providers on their physician panels. The author describes the efforts of one MCO to comply.

  12. Alternative Tobacco Product Use and Smoking Cessation: A National Study

    Science.gov (United States)

    Popova, Lucy

    2013-01-01

    Objectives. We investigated the frequency of alternative tobacco product use (loose leaf, moist snuff, snus, dissolvables, electronic cigarettes [e-cigarettes]) among smokers and the association with quit attempts and intentions. Methods. A nationally representative probability-based cross-sectional survey of 1836 current or recently former adult smokers was completed in November 2011. Multivariate logistic regressions evaluated associations between alternative tobacco product use and smoking cessation behaviors. Results. Of the smokers, 38% had tried an alternative tobacco product, most frequently e-cigarettes. Alternative tobacco product use was associated with having made a quit attempt, and those intending to quit were significantly more likely to have tried and to currently use the products than were smokers with no intentions to quit. Use was not associated with successful quit attempts. Interest in future use of alternative tobacco products was low, except for e-cigarettes. Conclusions. Alternative tobacco products are attractive to smokers who want to quit smoking, but these data did not indicate that alternative tobacco products promote cessation. Unsubstantiated overt and implied claims that alternative tobacco products aid smoking cessation should be prohibited. PMID:23488521

  13. Agricultural runoff pollution control by a grassed swales coupled with wetland detention ponds system: a case study in Taihu Basin, China.

    Science.gov (United States)

    Zhao, Jinhui; Zhao, Yaqian; Zhao, Xiaoli; Jiang, Cheng

    2016-05-01

    The performance of a field grassed swales (GSs) coupled with wetland detention ponds (WDPs) system was monitored under four typical rainfall events to assess its effectiveness on agricultural runoff pollution control in Taihu Basin, China. The results indicated that suspended solids (SS) derived from the flush process has significant influence on pollution loads in agricultural runoff. Determination of first flush effect (FFE) indicated that total suspended solids (TSS) and total phosphorus (TP) exhibited moderate FFE, while chemical oxygen demand (COD) and total nitrogen (TN) showed weak FFE. Average removal efficiencies of 83.5 ± 4.5, 65.3 ± 6.8, 91.6 ± 3.8, and 81.3 ± 5.8 % for TSS, COD, TN, and TP were achieved, respectively. The GSs played an important role in removing TSS and TP and acted as a pre-treatment process to prevent clogging of the subsequent WDPs. Particle size distributions (PSDs) analysis indicated that coarse particles larger than 75 μm accounted for 80 % by weight of the total particles in the runoff. GSs can effectively reduce coarse particles (≥75 μm) in runoff, while its removal efficiency for fine particles (runoff pollution control.

  14. Runoff generation in a Mediterranean semi-arid landscape: Thresholds, scale, rainfall and catchment characteristics

    Science.gov (United States)

    Ries, Fabian; Schmidt, Sebastian; Sauter, Martin; Lange, Jens

    2016-04-01

    detected. Besides rainfall characteristics, we found that available soil water storage capacity and bedrock permeability are the most important factors controlling runoff generation in our study area.

  15. Urban Runoff: National Management Measures

    Science.gov (United States)

    This helps citizens and municipalities in urban areas protect bodies of water from polluted runoff . These scientifically sound techniques are the best practices known today. The guidance helps states to implement their nonpoint source control program.

  16. SPATIAL DISTRIBUTION OF THE AVERAGE RUNOFF IN THE IZA AND VIȘEU WATERSHEDS

    Directory of Open Access Journals (Sweden)

    HORVÁTH CS.

    2015-03-01

    Full Text Available The average runoff represents the main parameter with which one can best evaluate an area’s water resources and it is also an important characteristic in al river runoff research. In this paper we choose a GIS methodology for assessing the spatial evolution of the average runoff, using validity curves we identifies three validity areas in which the runoff changes differently with altitude. The tree curves were charted using the average runoff values of 16 hydrometric stations from the area, eight in the Vișeu and eight in the Iza river catchment. Identifying the appropriate areas of the obtained correlations curves (between specific average runoff and catchments mean altitude allowed the assessment of potential runoff at catchment level and on altitudinal intervals. By integrating the curves functions in to GIS we created an average runoff map for the area; from which one can easily extract runoff data using GIS spatial analyst functions. The study shows that from the three areas the highest runoff corresponds with the third zone but because it’s small area the water volume is also minor. It is also shown that with the use of the created runoff map we can compute relatively quickly correct runoff values for areas without hydrologic control.

  17. Simulation and assessment of urbanization impacts on runoff metrics

    DEFF Research Database (Denmark)

    Zhang, Yongyong; Xia, Jun; Yu, Jingjie

    2018-01-01

    changes. The Qing River catchment as a peri-urban catchment in the Beijing metropolitan area is selected as our study region. Results show that: (1) the dryland agriculture is decreased from 13.9% to 1.5% of the total catchment area in the years 2000–2015, while the percentages of impervious surface...... information for urban planning such as Sponge City design.......Urbanization-induced landuse changes alter runoff regimes in complex ways. In this study, a detailed investigation of the urbanization impacts on runoff regimes is provided by using multiple runoff metrics and with consideration of landuse dynamics. A catchment hydrological model is modified...

  18. Testing the Runoff Tool in Sicilian vineyards: adopting best management practices to prevent agricultural surface runoff

    Science.gov (United States)

    Singh, Manpriet; Dyson, Jeremy; Capri, Ettore

    2016-04-01

    Over the last decades rainfall has become more intense in Sicily, making large proportions of steeply sloping agricultural land more vulnerable to soil erosion, mainly orchards and vineyards (Diodato and Bellocchi 2010). The prevention of soil degradation is indirectly addressed in the European Union's Water Framework Directive (2000/60/EC) and Sustainable Use Directive (2009/128/EC). As a consequence, new EU compliance conditions for food producers requires them to have tools and solutions for on-farm implementation of sustainable practices (Singh et al. 2014). The Agricultural Runoff and Best Management Practice Tool has been developed by Syngenta to help farm advisers and managers diagnose the runoff potential from fields with visible signs of soil erosion. The tool consists of 4 steps including the assessment of three key landscape factors (slope, topsoil permeability and depth to restrictive horizon) and 9 mainly soil and crop management factors influencing the runoff potential. Based on the runoff potential score (ranging from 0 to 10), which is linked to a runoff potential class, the Runoff Tool uses in-field and edge-of-the-field Best Management Practices (BMPs) to mitigate runoff (aligned with advice from ECPA's TOPPS-prowadis project). The Runoff tool needs testing in different regions and crops to create a number of use scenarios with regional/crop specific advice on BMPs. For this purpose the Tool has been tested in vineyards of the Tasca d'Almerita and Planeta wineries, which are large family-owned estates with long-standing tradition in viticulture in Sicily. In addition to runoff potential scores, Visual Soil Assessment (VSA) scores have been calculated to allow for a comparison between different diagnostic tools. VSA allows for immediate diagnosis of soil quality (a higher score means a better soil quality) including many indicators of runoff (Shepherd 2008). Runoff potentials were moderate to high in all tested fields. Slopes were classified as

  19. 29 CFR 102.70 - Runoff election.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 2 2010-07-01 2010-07-01 false Runoff election. 102.70 Section 102.70 Labor Regulations... Runoff election. (a) The regional director shall conduct a runoff election, without further order of the... objections are filed as provided in § 102.69. Only one runoff shall be held pursuant to this section. (b...

  20. 5 CFR 2422.28 - Runoff elections.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Runoff elections. 2422.28 Section 2422.28... FEDERAL LABOR RELATIONS AUTHORITY REPRESENTATION PROCEEDINGS § 2422.28 Runoff elections. (a) When a runoff may be held. A runoff election is required in an election involving at least three (3) choices, one of...

  1. Modelling runoff on ceramic tile roofs using the kinematic wave equations

    Science.gov (United States)

    Silveira, Alexandre; Abrantes, João; de Lima, João; Lira, Lincoln

    2016-04-01

    Rainwater harvesting is a water saving alternative strategy that presents many advantages and can provide solutions to address major water resources problems, such as fresh water scarcity, urban stream degradation and flooding. In recent years, these problems have become global challenges, due to climatic change, population growth and increasing urbanisation. Generally, roofs are the first to come into contact with rainwater; thus, they are the best candidates for rainwater harvesting. In this context, the correct evaluation of roof runoff quantity and quality is essential to effectively design rainwater harvesting systems. Despite this, many studies usually focus on the qualitative aspects in detriment of the quantitative aspects. Laboratory studies using rainfall simulators have been widely used to investigate rainfall-runoff processes. These studies enabled a detailed exploration and systematic replication of a large range of hydrologic conditions, such as rainfall spatial and temporal characteristics, providing for a fast way to obtain precise and consistent data that can be used to calibrate and validate numerical models. This study aims to evaluate the performance of a kinematic wave based numerical model in simulating runoff on sloping roofs, by comparing the numerical results with the ones obtained from laboratory rainfall simulations on a real-scale ceramic tile roof (Lusa tiles). For all studied slopes, simulated discharge hydrographs had a good adjust to observed ones. Coefficient of determination and Nash-Sutcliffe efficiency values were close to 1.0. Particularly, peak discharges, times to peak and peak durations were very well simulated.

  2. Snowmelt runoff: a new focus of urban nonpoint source pollution.

    Science.gov (United States)

    Zhu, Hui; Xu, Yingying; Yan, Baixing; Guan, Jiunian

    2012-11-30

    Irregular precipitation associated with global climate change had been causing various problems in urban regions. Besides the runoff due to rainfall in summer, the snowmelt runoff in early spring could also play an important role in deteriorating the water quality of the receiving waters. Due to global climate change, the snowfall has increased gradually in individual regions, and snowstorms occur more frequently, which leads to an enhancement of snowmelt runoff flow during the melting seasons. What is more, rivers just awaking from freezing constitute a frail ecosystem, with poor self-purification capacity, however, the urban snowmelt runoff could carry diverse pollutants accumulated during the winter, such as coal and/or gas combustion products, snowmelting agents, automotive exhaust and so on, which seriously threaten the receiving water quality. Nevertheless, most of the research focused on the rainfall runoff in rainy seasons, and the study on snowmelt runoff is still a neglected field in many countries and regions. In conclusion, due to the considerable water quantity and the worrisome water quality, snowmelt runoff in urban regions with large impervious surface areas should be listed among the important targets in urban nonpoint source pollution management and control.

  3. Snowmelt Runoff: A New Focus of Urban Nonpoint Source Pollution

    Science.gov (United States)

    Zhu, Hui; Xu, Yingying; Yan, Baixing; Guan, Jiunian

    2012-01-01

    Irregular precipitation associated with global climate change had been causing various problems in urban regions. Besides the runoff due to rainfall in summer, the snowmelt runoff in early spring could also play an important role in deteriorating the water quality of the receiving waters. Due to global climate change, the snowfall has increased gradually in individual regions, and snowstorms occur more frequently, which leads to an enhancement of snowmelt runoff flow during the melting seasons. What is more, rivers just awaking from freezing cosntitute a frail ecosystem, with poor self-purification capacity, however, the urban snowmelt runoff could carry diverse pollutants accumulated during the winter, such as coal and/or gas combustion products, snowmelting agents, automotive exhaust and so on, which seriously threaten the receiving water quality. Nevertheless, most of the research focused on the rainfall runoff in rainy seasons, and the study on snowmelt runoff is still a neglected field in many countries and regions. In conclusion, due to the considerable water quantity and the worrisome water quality, snowmelt runoff in urban regions with large impervious surface areas should be listed among the important targets in urban nonpoint source pollution management and control. PMID:23202881

  4. Study of an alternative system for manganese bath efficiency determination

    International Nuclear Information System (INIS)

    Leite, Sandro Passos

    2010-01-01

    An alternative irradiation system, using radioisotope neutron sources and a small MnSO 4 solution volume, was proposed m this work to determine the Manganese Bath System (MBS) efficiency. The irradiation system was characterized through simulations with the MCNP radiation transport code from the modeling of 252 Cf(f,n) and 238 PuBe(alpha,n) neutron sources in several MnSO 4 solution volumes and different neutron reflector medium for this solution. The parameter calculated in the simulations was the manganese neutron specific capture (MNSC), which is related to the MnSO 4 solution specific activity. From the proposed systems for 252 Cf (f, n) and 238 PuBe (alpha,n) the NSCM was increased hundred times, in relation with that achieved in the LN/LNMRI/IRD MBS system simulation when irradiated by each these neutron sources. During study for irradiation system characterization its concept was verified using a assemble of test irradiation (ATI), which were spherical glass cavities, with few centimeter in radius, filled with MnSO 4 solution, with and without presence of a neutron reflector medium. These TIA were used in four efficiency measurements and the average value was obtained. (author)

  5. Functional nanostructured materials for stormwater runoff treatment

    DEFF Research Database (Denmark)

    Ko, Dongah

    Numerous heavy metal removal practices for stormwater runoff have been studied and applied; however, there is still room for improvement. Among these practices, adsorption has proven to be the most efficient way of removing heavy metals. Commonly used adsorbents have an innate sorption capacity...... in relation to high concentrations of heavy metal ions, but if they are to be used for stormwater runoff, high affinity with rapid sorption kinetics for low concentrations of heavy metals is necessary. Therefore, in this study, new types of functional nanostructured polymer sorbents for effective heavy metal...... removal from stormwater are suggested. First, comparison studies of several existing polymer sorbents were conducted, to find decisive functional groups for removing heavy metals from the solution. To enhance the sorption kinetics and affinity of polymer sorbents in the presence of competing ions, sulphur...

  6. The effect of polyacrylamide (PAM) applications on infiltration, runoff ...

    African Journals Online (AJOL)

    . Anionic polyacrylamide (PAM) application to soils is an effective soil conservation practice for reducing runoff and soil losses caused by erosion. It also increases the infiltration rate of soils. The objective of this study was conducted to ...

  7. Treatment of contaminated roadway runoff using vegetated filter strips.

    Science.gov (United States)

    2009-01-01

    The overall goal of this field study was to evaluate the potential effectiveness of vegetated highway embankments as a stormwater runoff best management practice (BMP) for retention of metals, polycyclic aromatic hydrocarbons (PAHs), and particulates...

  8. Applicability of Doppler weather radar based rainfall data for runoff ...

    Indian Academy of Sciences (India)

    Radar-based hydrological studies in various countries have proven that ... in view of topographical and terrain constraints, cost restrictions and maintenance- .... SCS Unit Hydrograph (SCS UH) method converts surplus rainfall into runoff at the.

  9. An application of artificial intelligence for rainfall–runoff modeling

    Indian Academy of Sciences (India)

    This study proposes an application of two techniques of artificial intelligence (AI) ... (2006) applied rainfall–runoff modeling using ANN ... in artificial intelligence, engineering and science .... usually be estimated from a sample of observations.

  10. Bivariate Rainfall and Runoff Analysis Using Shannon Entropy Theory

    Science.gov (United States)

    Rahimi, A.; Zhang, L.

    2012-12-01

    Rainfall-Runoff analysis is the key component for many hydrological and hydraulic designs in which the dependence of rainfall and runoff needs to be studied. It is known that the convenient bivariate distribution are often unable to model the rainfall-runoff variables due to that they either have constraints on the range of the dependence or fixed form for the marginal distributions. Thus, this paper presents an approach to derive the entropy-based joint rainfall-runoff distribution using Shannon entropy theory. The distribution derived can model the full range of dependence and allow different specified marginals. The modeling and estimation can be proceeded as: (i) univariate analysis of marginal distributions which includes two steps, (a) using the nonparametric statistics approach to detect modes and underlying probability density, and (b) fitting the appropriate parametric probability density functions; (ii) define the constraints based on the univariate analysis and the dependence structure; (iii) derive and validate the entropy-based joint distribution. As to validate the method, the rainfall-runoff data are collected from the small agricultural experimental watersheds located in semi-arid region near Riesel (Waco), Texas, maintained by the USDA. The results of unviariate analysis show that the rainfall variables follow the gamma distribution, whereas the runoff variables have mixed structure and follow the mixed-gamma distribution. With this information, the entropy-based joint distribution is derived using the first moments, the first moments of logarithm transformed rainfall and runoff, and the covariance between rainfall and runoff. The results of entropy-based joint distribution indicate: (1) the joint distribution derived successfully preserves the dependence between rainfall and runoff, and (2) the K-S goodness of fit statistical tests confirm the marginal distributions re-derived reveal the underlying univariate probability densities which further

  11. WRAP Module 1 sampling strategy and waste characterization alternatives study

    Energy Technology Data Exchange (ETDEWEB)

    Bergeson, C.L.

    1994-09-30

    The Waste Receiving and Processing Module 1 Facility is designed to examine, process, certify, and ship drums and boxes of solid wastes that have a surface dose equivalent of less than 200 mrem/h. These wastes will include low-level and transuranic wastes that are retrievably stored in the 200 Area burial grounds and facilities in addition to newly generated wastes. Certification of retrievably stored wastes processing in WRAP 1 is required to meet the waste acceptance criteria for onsite treatment and disposal of low-level waste and mixed low-level waste and the Waste Isolation Pilot Plant Waste Acceptance Criteria for the disposal of TRU waste. In addition, these wastes will need to be certified for packaging in TRUPACT-II shipping containers. Characterization of the retrievably stored waste is needed to support the certification process. Characterization data will be obtained from historical records, process knowledge, nondestructive examination nondestructive assay, visual inspection of the waste, head-gas sampling, and analysis of samples taken from the waste containers. Sample characterization refers to the method or methods that are used to test waste samples for specific analytes. The focus of this study is the sample characterization needed to accurately identify the hazardous and radioactive constituents present in the retrieved wastes that will be processed in WRAP 1. In addition, some sampling and characterization will be required to support NDA calculations and to provide an over-check for the characterization of newly generated wastes. This study results in the baseline definition of WRAP 1 sampling and analysis requirements and identifies alternative methods to meet these requirements in an efficient and economical manner.

  12. WRAP Module 1 sampling strategy and waste characterization alternatives study

    International Nuclear Information System (INIS)

    Bergeson, C.L.

    1994-01-01

    The Waste Receiving and Processing Module 1 Facility is designed to examine, process, certify, and ship drums and boxes of solid wastes that have a surface dose equivalent of less than 200 mrem/h. These wastes will include low-level and transuranic wastes that are retrievably stored in the 200 Area burial grounds and facilities in addition to newly generated wastes. Certification of retrievably stored wastes processing in WRAP 1 is required to meet the waste acceptance criteria for onsite treatment and disposal of low-level waste and mixed low-level waste and the Waste Isolation Pilot Plant Waste Acceptance Criteria for the disposal of TRU waste. In addition, these wastes will need to be certified for packaging in TRUPACT-II shipping containers. Characterization of the retrievably stored waste is needed to support the certification process. Characterization data will be obtained from historical records, process knowledge, nondestructive examination nondestructive assay, visual inspection of the waste, head-gas sampling, and analysis of samples taken from the waste containers. Sample characterization refers to the method or methods that are used to test waste samples for specific analytes. The focus of this study is the sample characterization needed to accurately identify the hazardous and radioactive constituents present in the retrieved wastes that will be processed in WRAP 1. In addition, some sampling and characterization will be required to support NDA calculations and to provide an over-check for the characterization of newly generated wastes. This study results in the baseline definition of WRAP 1 sampling and analysis requirements and identifies alternative methods to meet these requirements in an efficient and economical manner

  13. Impact of land use, soil and DEM databases on surface runoff assessment with GIS decision support tool: A study case on the Briançon vineyard catchment (Gard, France)

    Science.gov (United States)

    Regazzoni, C.; Payraudeau, S.

    2012-04-01

    Runoff and associated erosion represent a primary mode of mobilization and transfer of pesticides from agricultural lands to watercourses and groundwater. The pesticides toxicity is potentially higher at the headwater catchment scale. These catchments are usually ungauged and characterized by temporary streams. Several mitigation strategies and management practices are currently used to mitigate the pesticides mixtures in agro-ecosystems. Among those practices, Stormwater Wetlands (SW) could be implemented to store surface runoff and to mitigate pesticides loads. The implementation of New Potential Stormwater Wetlands (NPSW) requires a diagnosis of intermittent runoff at the headwater catchment scale. The main difficulty to perform this diagnosis at the headwater catchment scale is to spatially characterize with enough accuracy the landscape components. Indeed, fields and field margins enhance or decrease the runoff and determine the pathways of hortonian overland flow. Land use, soil and Digital Elevation Model databases are systematically used. The question of the respective weight of each of these databases on the uncertainty of the diagnostic results is rarely analyzed at the headwater catchment scale. Therefore, this work focused (i) on the uncertainties of each of these databases and their propagation on the hortonian overland flow modelling, (ii) the methods to improve the accuracy of each database, (iii) the propagation of the databases uncertainties on intermittent runoff modelling and (iv) the impact of modelling cell size on the diagnosis. The model developed was a raster approach of the SCS-CN method integrating re-infiltration processes. The uncertainty propagation was analyzed on the Briançon vineyard catchment (Gard, France, 1400 ha). Based on this study site, the results showed that the geographic and thematic accuracies of regional soil database (1:250 000) were insufficient to correctly simulate the hortonian overland flow. These results have to

  14. A study on the alternative option for nuclear policy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J. W.; Choi, H. J.; Lee, J. Y.; Cho, D. K.; Jeon, K. S.; Park, S. W.; Hahn, D. H.; Yoon, J. S.; Lee, K. S. [KAERI, Daejeon (Korea, Republic of)

    2008-02-15

    Since a decision-making by intuitive judgement under uncertain future conditions can not select an optimum alternative, reaching an agreement for alternatives between experts requires a development of several scientific opinion collection methodologies and performing these methodologies. Therefore, opinion collection for all points related to the nuclear energy, public hearing induction related researches and the acts, procedure, etc. performed in developed countries such as U.S, U.K, France, etc. are reviewed and analyzed in this research. And after the analysis of domestic spent nuclear fuel management plan, Task Force Team composed of experts in several related areas is organized to suggest strategies and directions which are necessary for making a national policy. Beside, Task Force Team selects an optimum technical alternative by the analysis and comparison in depth between these technical alternatives to establish the policy direction. They also established the procedures such as opinion collecting, etc. through policy conference and forum and suggested the technical data related nuclear policy which supports the nuclear policy conference. Results from this research are expected to decrease the trial and error that has been occurred in the present policy-making procedure such as radioactive waste repository related procedure and contribute for socio-cultural stability. Moreover, opinion collection plan for developing a nuclear policy alternative is expected to contribute for making a nuclear policy in the nuclear policy conference so that the nuclear technology will be enhanced more.

  15. A study on the alternative option for nuclear policy

    International Nuclear Information System (INIS)

    Choi, J. W.; Choi, H. J.; Lee, J. Y.; Cho, D. K.; Jeon, K. S.; Park, S. W.; Hahn, D. H.; Yoon, J. S.; Lee, K. S.

    2008-02-01

    Since a decision-making by intuitive judgement under uncertain future conditions can not select an optimum alternative, reaching an agreement for alternatives between experts requires a development of several scientific opinion collection methodologies and performing these methodologies. Therefore, opinion collection for all points related to the nuclear energy, public hearing induction related researches and the acts, procedure, etc. performed in developed countries such as U.S, U.K, France, etc. are reviewed and analyzed in this research. And after the analysis of domestic spent nuclear fuel management plan, Task Force Team composed of experts in several related areas is organized to suggest strategies and directions which are necessary for making a national policy. Beside, Task Force Team selects an optimum technical alternative by the analysis and comparison in depth between these technical alternatives to establish the policy direction. They also established the procedures such as opinion collecting, etc. through policy conference and forum and suggested the technical data related nuclear policy which supports the nuclear policy conference. Results from this research are expected to decrease the trial and error that has been occurred in the present policy-making procedure such as radioactive waste repository related procedure and contribute for socio-cultural stability. Moreover, opinion collection plan for developing a nuclear policy alternative is expected to contribute for making a nuclear policy in the nuclear policy conference so that the nuclear technology will be enhanced more

  16. Technology Overview Using Case Studies of Alternative Landfill Technologies and Associated Regulatory Topics

    National Research Council Canada - National Science Library

    2003-01-01

    ... alternative landfill cover projects. The purpose of the case studies is to present examples of the flexibility used in the regulatory framework for approving alternative landfill cover designs, current research information about the use...

  17. Aluminum-based water treatment residual use in a constructed wetland for capturing urban runoff phosphorus: Column study

    Science.gov (United States)

    Aluminum-based water treatment residuals (Al-WTR) have a strong affinity to sorb phosphorus. In a proof-of-concept greenhouse column study, Al-WTR was surface-applied at 0, 62, 124, and 248 Mg/ha to 15 cm of soil on top of 46 cm of sand; Al-WTR rates were estimated to capture 0, 10, 20, and 40 year...

  18. Assessment of runoff contributing catchment areas in rainfall runoff modelling

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Johansen, C.; Schaarup-Jensen, Kjeld

    2006-01-01

    In numerical modelling of rainfall caused runoff in urban sewer systems an essential parameter is the hydrological reduction factor which defines the percentage of the impervious area contributing to the surface flow towards the sewer. As the hydrological processes during a rainfall are difficult...... to determine with significant precision the hydrological reduction factor is implemented to account all hydrological losses except the initial loss. This paper presents an inconsistency between calculations of the hydrological reduction factor, based on measurements of rainfall and runoff, and till now...... recommended literature values for residential areas. It is proven by comparing rainfall-runoff measurements from four different residential catchments that the literature values of the hydrological reduction factor are over-estimated for this type of catchment. In addition, different catchment descriptions...

  19. Monitored natural attenuation study of flood-borne nutrient run-offs in the marine environment of Napti, Batan, Aklan

    International Nuclear Information System (INIS)

    Sucgang, Raymond J.; Jamangal, Gorgonio; Manuntag, Monica; Templonuevo, Javie Gabriel; Wong, Carlene Dianne; Campos, Ace Bryan; Rafailes, Ma. Cherry

    2015-01-01

    Climate change-effected flooding transmits land-based nutrients to the marine environment. In this study, nitrate and phosphate levels in sediment and water were measured and compared in six sites in Napti, Batan, Aklan : Site 1-nerritic zone receiving flood water from waterways connected to agricultural areas; Site 2- intertidal community with mangal mangrove vegetation upstream of site 1; Site 3- waterway upstream of site 2; Site 4 - another area of waterway upstream of sites 1&2; SIte 5 - nipa mangrove plantation area upstream of site 4, and Site 6 - waterway upstream of sites 1 to 5 and in close proximity to agricultural areas. Soil and water chemistry were determined during pre and post typhoon Yolanda (Haiyan) flood event, using ion chromatography; bicarbonate was determined by titrimetry. Post flood measurements were performed in two sampling regimes, four months aprat. An average loading rate of nitrated at ∼15 parts per million/day was observed in all the sites. Concentrations of ions were significantly diminished (more than 10 times), during the second post flood measurement in sites with riparian vegetation (sites 2&5) while no significant changes in pollutant concentrations were found in the other sites without riparian vegetation. Conditions that maximize nitrate and nutrient removal in sediments were found to be neutral pH, high bicarbonate, and anoxic conditions. Evidences of denitrification and natural attenuation of pollutants by riparian vegetation were established in the study. (author)

  20. Predicting the Impacts of Climate Change on Runoff and Sediment Processes in Agricultural Watersheds: A Case Study from the Sunflower Watershed in the Lower Mississippi Basin

    Science.gov (United States)

    Elkadiri, R.; Momm, H.; Yasarer, L.; Armour, G. L.

    2017-12-01

    Climatic conditions play a major role in physical processes impacting soil and agrochemicals detachment and transportation from/in agricultural watersheds. In addition, these climatic conditions are projected to significantly vary spatially and temporally in the 21st century, leading to vast uncertainties about the future of sediment and non-point source pollution transport in agricultural watersheds. In this study, we selected the sunflower basin in the lower Mississippi River basin, USA to contribute in the understanding of how climate change affects watershed processes and the transport of pollutant loads. The climate projections used in this study were retrieved from the archive of World Climate Research Programme's (WCRP) Coupled Model Intercomparison Phase 5 (CMIP5) project. The CMIP5 dataset was selected because it contains the most up-to-date spatially downscaled and bias corrected climate projections. A subset of ten GCMs representing a range in projected climate were spatially downscaled for the sunflower watershed. Statistics derived from downscaled GCM output representing the 2011-2040, 2041-2070 and 2071-2100 time periods were used to generate maximum/minimum temperature and precipitation on a daily time step using the USDA Synthetic Weather Generator, SYNTOR. These downscaled climate data were then utilized as inputs to run in the Annualized Agricultural Non-Point Source (AnnAGNPS) pollution watershed model to estimate time series of runoff, sediment, and nutrient loads produced from the watershed. For baseline conditions a validated simulation of the watershed was created and validated using historical data from 2000 until 2015.

  1. System study of alternative waste management techniques: Final report

    International Nuclear Information System (INIS)

    1986-01-01

    This report summarizes the important results achieved in conjunction with the Research and Development Priority ''Alternative Waste Management Techniques'' sponsored by the Federal Ministry of Research and Technology from 1981 to 1984. The subject of these studies was solely ''direct disposal'' of spent fuel elements. For this purpose a reference concept was selected from a variety of possible processes and engineered in detailed form by firms in the nuclear industry. Those who worked on the engineering concepts consider this waste management method technically feasible. Several disposal casks have been fabricated. The basic licensability of direct disposal can be evaluated on the basis of the documentation developed by the companies. The direct disposal method was compared with the ''integrated waste management concept'' using reference fuel cycles with respect to the following criteria: radiological safety and nuclear material safeguards and, in addition, economic and energy-policy aspects. It was found that with respect to radiological safety, including the long-term safety of the final repository, there are no significant differences between the two fuel cycles with and without reprocessing. With respect to the nuclear material safeguards of a final repository containing spent fuel elements, there are still a number of unanswered questions. From an economic standpoint, direct disposal will be more economical in the foreseeable future than integrated waste management. Quantification of the effects of one or the other waste management method on the national economy is not necessarily possible. Reprocessing is supported primarily by technological and energy-policy considerations. On the basis of the results, the conclusion is reached that reprocessing should be pursued further, but that at the same time direct disposal should be developed to the point of practical maturity

  2. Assessment of Runoff Contributing Catchment Areas in Rainfall Runoff Modelling

    DEFF Research Database (Denmark)

    Thorndahl, Søren Liedtke; Johansen, C.; Schaarup-Jensen, Kjeld

    2005-01-01

    to determine with significant precision the hydrological reduction factor is implemented to account all hydrological losses except the initial loss. This paper presents an inconsistency between calculations of the hydrological reduction factor, based on measurements of rainfall and runoff, and till now...... recommended literary values for residential areas. It is proven by comparing rainfall-runoff measurements from four different residential catchments that the literary values of the hydrological reduction factor are over-estimated for this type of catchments. In addition, different catchment descriptions...

  3. Simulating runoff under changing climatic conditions: Revisiting an apparent deficiency of conceptual rainfall-runoff models

    Science.gov (United States)

    Fowler, Keirnan J. A.; Peel, Murray C.; Western, Andrew W.; Zhang, Lu; Peterson, Tim J.

    2016-03-01

    Hydrologic models have potential to be useful tools in planning for future climate variability. However, recent literature suggests that the current generation of conceptual rainfall runoff models tend to underestimate the sensitivity of runoff to a given change in rainfall, leading to poor performance when evaluated over multiyear droughts. This research revisited this conclusion, investigating whether the observed poor performance could be due to insufficient model calibration and evaluation techniques. We applied an approach based on Pareto optimality to explore trade-offs between model performance in different climatic conditions. Five conceptual rainfall runoff model structures were tested in 86 catchments in Australia, for a total of 430 Pareto analyses. The Pareto results were then compared with results from a commonly used model calibration and evaluation method, the Differential Split Sample Test. We found that the latter often missed potentially promising parameter sets within a given model structure, giving a false negative impression of the capabilities of the model. This suggests that models may be more capable under changing climatic conditions than previously thought. Of the 282[347] cases of apparent model failure under the split sample test using the lower [higher] of two model performance criteria trialed, 155[120] were false negatives. We discuss potential causes of remaining model failures, including the role of data errors. Although the Pareto approach proved useful, our aim was not to suggest an alternative calibration strategy, but to critically assess existing methods of model calibration and evaluation. We recommend caution when interpreting split sample results.

  4. Alternate Communications Spectrum Study (ACSS) for Aviation Data Links (ADL)

    Science.gov (United States)

    Matolak, David W.

    2003-01-01

    The aim of the work was to identify the key factors involved in the use of alternate spectrum in various bands for a future integrated CNS data link. The study focused on systems and spectral bands that can deliver VDL-or-higher data rates in a two-way communication setting (including air-ground, ground-air, and air-air modes of operation), with multiple platforms (aircraft) operating in the same local environment. We begin with a review of the initial task list, and the final task list. The final task list contained a focus upon spectral availability and related systems that could be affected by the deployment of a new aviation data link (ADL) system. Most of this addresses the lower few layers of the communications protocol stack. A brief review of current related efforts in the aeronautical community is then provided, in which we describe several systems and programs of interest. Participation in some of these efforts is recommended. We also delineate several of the advantages and disadvantages of these system/efforts, in view of anticipated requirements of a new ADL. Desired attributes of a new ADL system are then discussed, and a connection with existing systems is made. The need to consider a wider set of alternative systems and technologies is described, and the beneficial aspects of a particular transmission technique- spread spectrum-are discussed. We then discuss in more detail several potential spectral regions, in terms of propagation conditions, available technology, spectrum availability, and waveform selection. Some comments on the need for standardization are also provided. We note that none of the existing systems described will likely meet the full range of desired features of a new ADL, but that several systems and spectral regions offer promise in terms of one or more characteristics. A system design and analysis approach is then provided. In this, we again focus on the lower few layers of the protocol stack, and aim to capture the main features

  5. Study on Alternative Cargo Launch Options from the Lunar Surface

    Energy Technology Data Exchange (ETDEWEB)

    Cheryl A. Blomberg; Zamir A. Zulkefli; Spencer W. Rich; Steven D. Howe

    2013-07-01

    In the future, there will be a need for constant cargo launches from Earth to Mars in order to build, and then sustain, a Martian base. Currently, chemical rockets are used for space launches. These are expensive and heavy due to the amount of necessary propellant. Nuclear thermal rockets (NTRs) are the next step in rocket design. Another alternative is to create a launcher on the lunar surface that uses magnetic levitation to launch cargo to Mars in order to minimize the amount of necessary propellant per mission. This paper investigates using nuclear power for six different cargo launching alternatives, as well as the orbital mechanics involved in launching cargo to a Martian base from the moon. Each alternative is compared to the other alternative launchers, as well as compared to using an NTR instead. This comparison is done on the basis of mass that must be shipped from Earth, the amount of necessary propellant, and the number of equivalent NTR launches. Of the options, a lunar coil launcher had a ship mass that is 12.7% less than the next best option and 17 NTR equivalent launches, making it the best of the presented six options.

  6. Effect of climate change on stormwater runoff characteristics and treatment efficiencies of stormwater retention ponds; a case study from Denmark using TSS and Cu as indicator pollutants. SpringerPlus, 5:1984, 1-12

    DEFF Research Database (Denmark)

    Sharma, Anitha Kumari; Vezzaro, Luca; Birch, Heidi

    2016-01-01

    This study investigated the potential effect of climate changes on stormwater pollution runoff characteristics and the treatment efficiency of a stormwater retention pond in a 95 ha catchment in Denmark. An integrated dynamic stormwater runoff quality and treatment model was used to simulate two...... scenarios: one representing the current climate and another representing a future climate scenario with increased intensity of extreme rainfall events and longer dry weather periods. 100-year long high-resolution rainfall time series downscaled from regional climate model projections were used as input...... concentrations. Similar results are expected for other particle bound pollutants including metals and slowly biodegradable organic substances such as PAH. Acute toxicity impacts to downstream surface waters seem to be only slightly affected. A minor increase in yearly loads of sediments and particle...

  7. Assessment of stormwater runoff management practices and BMPs under soil sealing: A study case in a peri-urban watershed of the metropolitan area of Rome (Italy).

    Science.gov (United States)

    Recanatesi, Fabio; Petroselli, Andrea; Ripa, Maria Nicolina; Leone, Antonio

    2017-10-01

    By 2006, almost 100,000 km 2 of EU soil (2.3% of the whole territory) had been sealed, with a per capita quota of 200 m 2 of sealed surface for each EU citizen. Italy, in 2016, recorded a soil sealing rate of 2.8% of the entire territory. In this context, the urban expansion which occurred in past decades is considered one of the main causes of the increase in flood frequency and intensity in small catchments, causing both social and financial damage. In the present paper, the positive impact of introducing Best Management Practices (BMPs) at urban scale is assessed, with particular regard to the decreasing of flood prone areas. A suburban watershed of the metropolitan area of Rome has been selected for a study case, as its soil sealing rate can be considered paradigmatic at this scale. Starting from the analysis of rainfall events occurring between 2008 and 2011 which caused millions of euros worth of damage, and using a high resolution data set in a GIS environment, two scenarios, with and without BMP introduction, are evaluated applying a rainfall-runoff model and a bidimensional hydraulic model. From a comparison of the flood maps with and without the introduction of BMPs, it was determined that in 90% of the circumstances the employment of the BMPs would completely remove the hydraulic risk, while in the remaining 10% the BMP would at least reduce the areas subjected to flooding. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Frequency analysis of urban runoff quality in an urbanizing catchment of Shenzhen, China

    Science.gov (United States)

    Qin, Huapeng; Tan, Xiaolong; Fu, Guangtao; Zhang, Yingying; Huang, Yuefei

    2013-07-01

    This paper investigates the frequency distribution of urban runoff quality indicators using a long-term continuous simulation approach and evaluates the impacts of proposed runoff control schemes on runoff quality in an urbanizing catchment in Shenzhen, China. Four different indicators are considered to provide a comprehensive assessment of the potential impacts: total runoff depth, event pollutant load, Event Mean Concentration, and peak concentration during a rainfall event. The results obtained indicate that urban runoff quantity and quality in the catchment have significant variations in rainfall events and a very high rate of non-compliance with surface water quality regulations. Three runoff control schemes with the capacity to intercept an initial runoff depth of 5 mm, 10 mm, and 15 mm are evaluated, respectively, and diminishing marginal benefits are found with increasing interception levels in terms of water quality improvement. The effects of seasonal variation in rainfall events are investigated to provide a better understanding of the performance of the runoff control schemes. The pre-flood season has higher risk of poor water quality than other seasons after runoff control. This study demonstrates that frequency analysis of urban runoff quantity and quality provides a probabilistic evaluation of pollution control measures, and thus helps frame a risk-based decision making for urban runoff quality management in an urbanizing catchment.

  9. Predicting runoff of suspended solids and particulate phosphorus for selected Louisiana soils using simple soil tests.

    Science.gov (United States)

    Udeigwe, Theophilus K; Wang, Jim J; Zhang, Hailin

    2007-01-01

    This study was conducted to evaluate the relationships among total suspended solids (TSS) and particulate phosphorus (PP) in runoff and selected soil properties. Nine Louisiana soils were subjected to simulated rainfall events, and runoff collected and analyzed for various parameters. A highly significant relationship existed between runoff TSS and runoff turbidity. Both runoff TSS and turbidity were also significantly related to runoff PP, which on average accounted for more than 98% of total P (TP) in the runoff. Runoff TSS was closely and positively related to soil clay content in an exponential fashion (y=0.10e0.01x, R2=0.91, Psoil electrical conductivity (EC) (y=0.02 x(-3.95), R2=0.70, Psoil suspension turbidity" (SST) which measures turbidity in a 1:200 soil/water suspension, exhibited highly significant linear relationships with runoff TSS (y=0.06x-4.38, R2=0.82, Psoil clay content and EC in a multiple regression, suggesting that SST was able to account for the integrated effect of clay content and electrolytic background on runoff TSS. The SST test could be used for assessment and management of sediment and particulate nutrient losses in surface runoff.

  10. Influence of climate variability on large rivers runoff

    Directory of Open Access Journals (Sweden)

    B. Nurtaev

    2015-06-01

    Full Text Available In accordance with IPCC Report the influence of climate change on the water cycle will increase hydrologic variability by means of changing of precipitation patterns, melting of ice and change of runoff. Precipitation has increased in high northern latitudes and decreased in southern latitudes. This study presents an analysis of river runoffs trends in different climatic zones of the world in condition of climate change.

  11. Runoff response to climate change and human activities in a typical karst watershed, SW China

    Science.gov (United States)

    Xu, Yan; Wang, Shijie; Shu, Dongcai; Tian, Yichao

    2018-01-01

    This study aims to reveal the runoff variation characteristics of long time series in a karst region, analyse comprehensively its different driving factors, and estimate quantitatively the contribution rates of climate change and human activities to net runoff variation. Liudong river basin, a typical karst watershed in southwest China, is the study site. Statistical methods, such as linear fitting, the Morlet wavelet analysis, normalized curve and double mass curve, are applied to analyse the runoff of the watershed. Results show that the runoff in the karst watershed during the research period exhibits a three-stage change and the abrupt change points are the years 1981 and 2007: (1) 1968–1980, the runoff initially exhibited a trend of sustained decreasing and then an abrupt fluctuation. The runoff was obviously destroyed through precipitation-producing processes. Improper land utilisation and serious forest and grass destruction intensified the fluctuation variation amplitude of the runoff. (2) 1981–2006, the changing processes of runoff and precipitation exhibited good synchronism. Precipitation significantly affected runoff variation and human activities had a slight interference degree. (3) 2007–2013, the fluctuation range of runoff was considerably smaller than that of precipitation. The significant growth of forest and grassland areas and the increase in water consumption mitigated runoff fluctuation and greatly diminished runoff variation amplitude. According to calculation, the relative contribution rates of precipitation and human activities to net runoff variation with 1981–2007 as the reference period were −81% and 181% in average, respectively, during 1968–1980, and −117% and 217% in average, respectively, during 2007–2013. In general, the analysis of runoff variation trend and of the contribution rate of its main influencing factors in the typical karst watershed for nearly half a century may be significant to solve the drought

  12. Runoff response to climate change and human activities in a typical karst watershed, SW China.

    Science.gov (United States)

    Xu, Yan; Wang, Shijie; Bai, Xiaoyong; Shu, Dongcai; Tian, Yichao

    2018-01-01

    This study aims to reveal the runoff variation characteristics of long time series in a karst region, analyse comprehensively its different driving factors, and estimate quantitatively the contribution rates of climate change and human activities to net runoff variation. Liudong river basin, a typical karst watershed in southwest China, is the study site. Statistical methods, such as linear fitting, the Morlet wavelet analysis, normalized curve and double mass curve, are applied to analyse the runoff of the watershed. Results show that the runoff in the karst watershed during the research period exhibits a three-stage change and the abrupt change points are the years 1981 and 2007: (1) 1968-1980, the runoff initially exhibited a trend of sustained decreasing and then an abrupt fluctuation. The runoff was obviously destroyed through precipitation-producing processes. Improper land utilisation and serious forest and grass destruction intensified the fluctuation variation amplitude of the runoff. (2) 1981-2006, the changing processes of runoff and precipitation exhibited good synchronism. Precipitation significantly affected runoff variation and human activities had a slight interference degree. (3) 2007-2013, the fluctuation range of runoff was considerably smaller than that of precipitation. The significant growth of forest and grassland areas and the increase in water consumption mitigated runoff fluctuation and greatly diminished runoff variation amplitude. According to calculation, the relative contribution rates of precipitation and human activities to net runoff variation with 1981-2007 as the reference period were -81% and 181% in average, respectively, during 1968-1980, and -117% and 217% in average, respectively, during 2007-2013. In general, the analysis of runoff variation trend and of the contribution rate of its main influencing factors in the typical karst watershed for nearly half a century may be significant to solve the drought problem in the karst

  13. Sodium-Bearing Waste Treatment Alternatives Implementation Study

    Energy Technology Data Exchange (ETDEWEB)

    Charles M. Barnes; James B. Bosley; Clifford W. Olsen

    2004-07-01

    The purpose of this document is to discuss issues related to the implementation of each of the five down-selected INEEL/INTEC radioactive liquid waste (sodium-bearing waste - SBW) treatment alternatives and summarize information in three main areas of concern: process/technical, environmental permitting, and schedule. Major implementation options for each treatment alternative are also identified and briefly discussed. This report may touch upon, but purposely does not address in detail, issues that are programmatic in nature. Examples of these include how the SBW will be classified with respect to the Nuclear Waste Policy Act (NWPA), status of Waste Isolation Pilot Plant (WIPP) permits and waste storage availability, available funding for implementation, stakeholder issues, and State of Idaho Settlement Agreement milestones. It is assumed in this report that the SBW would be classified as a transuranic (TRU) waste suitable for disposal at WIPP, located in New Mexico, after appropriate treatment to meet transportation requirements and waste acceptance criteria (WAC).

  14. An approximate analytical solution for describing surface runoff and sediment transport over hillslope

    Science.gov (United States)

    Tao, Wanghai; Wang, Quanjiu; Lin, Henry

    2018-03-01

    Soil and water loss from farmland causes land degradation and water pollution, thus continued efforts are needed to establish mathematical model for quantitative analysis of relevant processes and mechanisms. In this study, an approximate analytical solution has been developed for overland flow model and sediment transport model, offering a simple and effective means to predict overland flow and erosion under natural rainfall conditions. In the overland flow model, the flow regime was considered to be transitional with the value of parameter β (in the kinematic wave model) approximately two. The change rate of unit discharge with distance was assumed to be constant and equal to the runoff rate at the outlet of the plane. The excess rainfall was considered to be constant under uniform rainfall conditions. The overland flow model developed can be further applied to natural rainfall conditions by treating excess rainfall intensity as constant over a small time interval. For the sediment model, the recommended values of the runoff erosion calibration constant (cr) and the splash erosion calibration constant (cf) have been given in this study so that it is easier to use the model. These recommended values are 0.15 and 0.12, respectively. Comparisons with observed results were carried out to validate the proposed analytical solution. The results showed that the approximate analytical solution developed in this paper closely matches the observed data, thus providing an alternative method of predicting runoff generation and sediment yield, and offering a more convenient method of analyzing the quantitative relationships between variables. Furthermore, the model developed in this study can be used as a theoretical basis for developing runoff and erosion control methods.

  15. Land cover controls on summer discharge and runoff solution chemistry of semi-arid urban catchments

    Science.gov (United States)

    Gallo, Erika L.; Brooks, Paul D.; Lohse, Kathleen A.; McLain, Jean E. T.

    2013-04-01

    SummaryRecharge of urban runoff to groundwater as a stormwater management practice has gained importance in semi-arid regions where water resources are scarce and urban centers are growing. Despite this trend, the importance of land cover in controlling semi-arid catchment runoff quantity and quality remains unclear. Here we address the question: How do land cover characteristics control the amount and quality of storm runoff in semi-arid urban catchments? We monitored summertime runoff quantity and quality from five catchments dominated by distinct urban land uses: low, medium, and high density residential, mixed use, and commercial. Increasing urban land cover increased runoff duration and the likelihood that a rainfall event would result in runoff, but did not increase the time to peak discharge of episodic runoff. The effect of urban land cover on hydrologic responses was tightly coupled to the magnitude of rainfall. At distinct rainfall thresholds, roads, percent impervious cover and the stormwater drainage network controlled runoff frequency, runoff depth and runoff ratios. Contrary to initial expectations, runoff quality did not vary in repose to impervious cover or land use. We identified four major mechanisms controlling runoff quality: (1) variable solute sourcing due to land use heterogeneity and above ground catchment connectivity; (2) the spatial extent of pervious and biogeochemically active areas; (3) the efficiency of overland flow and runoff mobilization; and (4) solute flushing and dilution. Our study highlights the importance of the stormwater drainage systems characteristics in controlling urban runoff quantity and quality; and suggests that enhanced wetting and in-stream processes may control solute sourcing and retention. Finally, we suggest that the characteristics of the stormwater drainage system should be integrated into stormwater management approaches.

  16. Climate change and runoff in south-western Australia

    Science.gov (United States)

    Silberstein, R. P.; Aryal, S. K.; Durrant, J.; Pearcey, M.; Braccia, M.; Charles, S. P.; Boniecka, L.; Hodgson, G. A.; Bari, M. A.; Viney, N. R.; McFarlane, D. J.

    2012-12-01

    SummaryThis paper presents the results of computer simulations of runoff from 13 major fresh and brackish river basins in south-western Australia (SWA) under climate projections obtained from 15 GCMs with three future global warming scenarios equivalent to global temperature rises of 0.7 °C, 1.0 °C and 1.3 °C by 2030. The objective was to apply an efficient methodology, consistent across a large region, to examine the implications of the best available projections in climate trends for future surface water resources. An ensemble of rainfall-runoff models was calibrated on stream flow data from 1975 to 2007 from 106 gauged catchments distributed throughout the basins of the study area. The sensitivity of runoff to projected changes in mean annual rainfall is examined using the climate 'elasticity' concept. Averaged across the study area, all 15 GCMs project declines in rainfall under all global warming scenarios with a median decline of 8% resulting in a median decline in runoff of 25%. Such uniformity in projections from GCMs is unusual. Over SWA the average annual runoff under the 5th wettest and 5th driest of the 45 projections of the 2030 climate declines by 10 and 42%, respectively. Under the 5th driest projection the runoff decline ranges from 53% in the northern region to 40% in the southern region. Strong regional variations in climate sensitivity are found with the proportional decline in runoff greatest in the northern region and the greatest volumetric declines in the wetter basins in the south. Since the mid 1970s stream flows into the major water supply reservoirs in SWA have declined by more than 50% following a 16% rainfall reduction. This has already had major implications for water resources planning and for the preservation of aquatic and riparian ecosystems in the region. Our results indicate that this reduction in runoff is likely to continue if future climate projections eventuate.

  17. River runoff influences on the Central Mediterranean overturning circulation

    Science.gov (United States)

    Verri, Giorgia; Pinardi, N.; Oddo, P.; Ciliberti, S. A.; Coppini, G.

    2018-03-01

    The role of riverine freshwater inflow on the Central Mediterranean Overturning Circulation (CMOC) was studied using a high-resolution ocean model with a complete distribution of rivers in the Adriatic and Ionian catchment areas. The impact of river runoff on the Adriatic and Ionian Sea basins was assessed by a twin experiment, with and without runoff, from 1999 to 2012. This study tries to show the connection between the Adriatic as a marginal sea containing the downwelling branch of the anti-estuarine CMOC and the large runoff occurring there. It is found that the multiannual CMOC is a persistent anti-estuarine structure with secondary estuarine cells that strengthen in years of large realistic river runoff. The CMOC is demonstrated to be controlled by wind forcing at least as much as by buoyancy fluxes. It is found that river runoff affects the CMOC strength, enhancing the amplitude of the secondary estuarine cells and reducing the intensity of the dominant anti-estuarine cell. A large river runoff can produce a positive buoyancy flux without switching off the antiestuarine CMOC cell, but a particularly low heat flux and wind work with normal river runoff can reverse it. Overall by comparing experiments with, without and with unrealistically augmented runoff we demonstrate that rivers affect the CMOC strength but they can never represent its dominant forcing mechanism and the potential role of river runoff has to be considered jointly with wind work and heat flux, as they largely contribute to the energy budget of the basin. Looking at the downwelling branch of the CMOC in the Adriatic basin, rivers are demonstrated to locally reduce the volume of Adriatic dense water formed in the Southern Adriatic Sea as a result of increased water stratification. The spreading of the Adriatic dense water into the Ionian abyss is affected as well: dense waters overflowing the Otranto Strait are less dense in a realistic runoff regime, with respect to no runoff experiment, and

  18. Alternative Forms of Energy Production and Political Reconfigurations: The Sociology of Alternative Energies as a Study of Collective Reorganization Potential

    International Nuclear Information System (INIS)

    Rumpala, Yannick

    2013-01-01

    Energy choices that are made in a society are also political choices. This article aims to study the extent to which these choices can be reoriented by technological developments related to renewable energies, thus contributing to a redistribution of possibilities and to social reorganization. Three steps are proposed to show that while the development of alternative energies depends on technological advances, it can, in this process, also reveal political potentials: 1) the first step clarifies the theoretical arguments that can be deployed in favour of an approach in terms of 'technological potentialism'; 2) the second step extends this approach by identifying a set of potentials linked to renewable energies and the model that could take shape through these alternative forms; 3) the third step examines how these potentials could find ways of being updated

  19. An assessment of the impact of motorway runoff on a pond, wetland and stream

    Energy Technology Data Exchange (ETDEWEB)

    Sriyaraj, K.; Shutes, R.B.E. [Middlesex University, London (United Kingdom). Urban Pollution Research Centre

    2001-07-01

    The impact of soil filtered runoff from a section of the M25 outer London motorway (constructed in 1981) on a pond, wetland and stream in a nature reserve was investigated by monitoring water, sediment. The tissues of the emergent plants Typha latifolia and Glyceria maxima collected from the pond were analysed for the heavy metals, Cd, Pb, Cu and Zn. Macroinvertebrates were monitored in the stream and biotic indices applied to the data. The plant tissue concentrations for Typha and Glyceria show decreasing metal concentrations from root to rhizome to leaf. This trend has previously been reported for Typha exposed to runoff although the tissue concentrations are lower in this study with the exception of Cd in root tissue. The Biological Monitoring Working Party (BMWP) score and Average Score Per Taxon (ASPT) for the stream at sites above and below the pond outlet are lower than the scores recorded by the Environment Agency for England and Wales at an upstream site above the Pond/Wetland. The sites have an Overall Quality Index of 'moderate water quality', and there is no evidence of a deterioration of biologically assessed water quality between them. The results of the study show the long-term impact on sediment of filtered road runoff discharges to a natural wetland and pond located in a nature reserve. The use of natural wetlands for the discharge of road runoff is inadvisable. Constructed wetlands in combination with other structures including settlement trenches and ponds should be considered as an alternative treatment option. (Author)

  20. The treatment of run-off from a fertiliser plant for nitrification, denitrification and phosphorus removal by use of constructed wetlands: a demonstration study.

    Science.gov (United States)

    Cooper, P F; McBarnet, W; O'Donnell, D; McMahon, A; Houston, L; Brian, M

    2010-01-01

    The paper describes an evaluation carried out on demonstration scale to show that it was possible to use a Hybrid Reed Bed System comprising a Horizontal flow and a Vertical Flow Bed for treating the high strength run-off from a fertiliser packaging plant. The site is located close to an estuary which is sensitive to nutrients. The environmental regulators were therefore concerned that excessive mass flows of nitrate, ammoniacal nitrogen and phosphate, potentially arising from the site run-off, were not discharged into the estuary. The fertiliser manufacturing company required a simple, low maintenance system for removing nitrogen and phosphorus. A series of experimental runs were carried out to characterise the performance of the Hybrid System, establishing the effluent quality that could be achieved and the mass removal rate which was appropriate for acceptable treatment. These tests showed that it was possible to achieve a reduction of 79% in Total N whilst using molasses as a carbon source for denitrification. When using a 4:1 recycle ratio this produced an effluent with concentrations of 14 mg NH(4)-N/litre and 18 mg NO(3)-N/litre from treating site run-off containing concentrations in the order of 75 mg/litre of both NH(3)N and NO(3)-N. Chemical dosing with an iron salt brought the P concentration down to around 0.5 mg PO(4)-P/litre.

  1. Trend and concentrations of legacy lead (Pb) in highway runoff

    International Nuclear Information System (INIS)

    Kayhanian, Masoud

    2012-01-01

    This study presents the results of lead (Pb) concentrations from both highway runoff and contaminated soil along 32 and 23 highway sites, respectively. In general, the Pb concentration on topsoil (0–15 cm) along highways was much higher than the Pb concentration in subsurface soil (15–60 cm). The Pb deposited on soil appears to be anthropogenic and a strong correlation was found between the Pb concentration in surface soil and highway runoff in urban areas. The concentration of Pb measured during 1980s from highways runoff throughout the world was up to 11 times higher than the measured values in mid 1990s and 2000s. The current Pb deposited on soil near highways appears to be a mixture of paint, tire weight balance and old leaded gasoline combustion. Overall, the Pb phase-out regulation reduced the Pb deposits in the environment and consequently lowered Pb loading into receiving waters. - Highlights: ► Pb concentrations in highway runoff ranged from 0.5 to 752 mg/L. ► 78% of total lead concentration in highway runoff was in particulate form. ► Pb deposited on highway sites was mostly within 0 to 15 cm of soil column. ► Pb concentration in highway runoff and top soil was strongly correlated. ► Current Pb concentration in highway runoff is up to 11 times lower than late 1980s. - Most Pb deposited on soil near highways is within the top 15 cm. This Pb is the major sources of Pb concentration in highway runoff that has substantially been reduced since lead phase-out era.

  2. Illustrative Case Study: Life Cycle Assessment of Four Window Alternatives

    DEFF Research Database (Denmark)

    Owsianiak, Mikołaj; Bjørn, Anders; Bugge, Heidi

    2018-01-01

    This report serves as an example report on how to perform an LCA according to the guidance given in Chap. 37 and how to structure the report according to the reporting template in Chap. 38. The goals of the LCA were (i) to perform a benchmarking of a prototype wood/composite (W/C) window made out...... of glass fibre against three alternative window types currently offered in the market (made of wood (W), wood/aluminium (W/ALU), and PVC) and (ii) to identify environmental hotspots for each window system....

  3. Greenfield Alternative Study LEU-Mo Fuel Fabrication Facility

    Energy Technology Data Exchange (ETDEWEB)

    Washington Division of URS

    2008-07-01

    This report provides the initial “first look” of the design of the Greenfield Alternative of the Fuel Fabrication Capability (FFC); a facility to be built at a Greenfield DOE National Laboratory site. The FFC is designed to fabricate LEU-Mo monolithic fuel for the 5 US High Performance Research Reactors (HPRRs). This report provides a pre-conceptual design of the site, facility, process and equipment systems of the FFC; along with a preliminary hazards evaluation, risk assessment as well as the ROM cost and schedule estimate.

  4. Run-off from roofs

    International Nuclear Information System (INIS)

    Roed, J.

    1985-01-01

    In order to find the run-off from roof material a roof has been constructed with two different slopes (30 deg C and 45 deg C). Beryllium-7 and caesium-137 has been used as tracers. Considering new roof material the pollution removed by runoff processes has been shown to be very different for various roof materials. The pollution is much more easily removed from silicon-treated material than from porous red-tile roof material. Caesium is removed more easily than beryllium. The content of caesium in old roof materials is greater in red-tile than in other less-porous materials. However, the measured removal from new material does not correspond to the amount accumulated in the old. This could be explained by weathering and by saturation effects. This last effect is probably the more important. The measurements on old material indicates a removal of 44-86% of the caesium pollution by run-off, whereas the measurement on new showed a removal of only 31-50%. It has been demonstrated that the pollution concentration in the run-off water could be very different from that in rainwater. The work was part of the EEC Radiation Protection Programme and done under a subcontract with Association Euratom-C.E.A. No. SC-014-BIO-F-423-DK(SD) under contract No. BIO-F-423-81-F. (author)

  5. Spot Spraying Reduces Herbicide Concentrations in Runoff.

    Science.gov (United States)

    Melland, Alice R; Silburn, D Mark; McHugh, Allen D; Fillols, Emilie; Rojas-Ponce, Samuel; Baillie, Craig; Lewis, Stephen

    2016-05-25

    Rainfall simulator trials were conducted on sugar cane paddocks across dry-tropical and subtropical Queensland, Australia, to examine the potential for spot spraying to reduce herbicide losses in runoff. Recommended rates of the herbicides glyphosate, 2,4-D, fluoroxypyr, atrazine, and diuron were sprayed onto 0, 20, 40, 50, 70, or 100% of the area of runoff plots. Simulated rainfall was applied 2 days after spraying to induce runoff at one plant cane and three ratoon crop sites. Over 50% of all herbicides were transported in the dissolved phase of runoff, regardless of the herbicide's sediment-water partition coefficient. For most sites and herbicides, runoff herbicide concentrations decreased with decreasing spray coverage and with decreasing herbicide load in the soil and cane residues. Importantly, sites with higher infiltration prior to runoff and lower total runoff had lower runoff herbicide concentrations.

  6. Characterization of Urban Runoff Pollution between Dissolved and Particulate Phases

    Science.gov (United States)

    Wei, Zhang; Simin, Li; Fengbing, Tang

    2013-01-01

    To develop urban stormwater management effectively, characterization of urban runoff pollution between dissolved and particulate phases was studied by 12 rainfall events monitored for five typical urban catchments. The average event mean concentration (AEMC) of runoff pollutants in different phases was evaluated. The AEMC values of runoff pollutants in different phases from urban roads were higher than the ones from urban roofs. The proportions of total dissolved solids, total dissolved nitrogen, and total dissolved phosphorus in total ones for all the catchments were 26.19%–30.91%, 83.29%–90.51%, and 61.54–68.09%, respectively. During rainfall events, the pollutant concentration at the initial stage of rainfall was high and then sharply decreased to a low value. Affected by catchments characterization and rainfall distribution, the highest concentration of road pollutants might appear in the later period of rainfall. Strong correlations were also found among runoffs pollutants in different phases. Total suspended solid could be considered as a surrogate for particulate matters in both road and roof runoff, while dissolved chemical oxygen demand could be regarded as a surrogate for dissolved matters in roof runoff. PMID:23935444

  7. Pollution loads in urban runoff and sanitary wastewater.

    Science.gov (United States)

    Taebi, Amir; Droste, Ronald L

    2004-07-05

    While more attention has been paid in recent years to urban point source pollution control through the establishment of wastewater treatment plants in many developing countries, no considerable planning nor any serious measures have been taken to control urban non-point source pollution (urban stormwater runoff). The present study is a screening analysis to investigate the pollution loads in urban runoff compared to point source loads as a first prerequisite for planning and management of receiving water quality. To compare pollutant loads from point and non-point urban sources, the pollutant load is expressed as the weight of pollutant per hectare area per year (kg/ha.year). Unit loads were estimated in stormwater runoff, raw sanitary wastewater and secondary treatment effluents in Isfahan, Iran. Results indicate that the annual pollution load in urban runoff is lower than the annual pollution load in sanitary wastewater in areas with low precipitation but it is higher in areas with high precipitation. Two options, namely, advanced treatment (in lieu of secondary treatment) of sanitary wastewater and urban runoff quality control systems (such as detention ponds) were investigated as controlling systems for pollution discharges into receiving waters. The results revealed that for Isfahan, as a low precipitation urban area, advanced treatment is a more suitable option, but for high precipitation urban areas, urban surface runoff quality control installations were more effective for suspended solids and oxygen-demanding matter controls, and that advanced treatment is the more effective option for nutrient control.

  8. Characterization of urban runoff pollution between dissolved and particulate phases.

    Science.gov (United States)

    Wei, Zhang; Simin, Li; Fengbing, Tang

    2013-01-01

    To develop urban stormwater management effectively, characterization of urban runoff pollution between dissolved and particulate phases was studied by 12 rainfall events monitored for five typical urban catchments. The average event mean concentration (AEMC) of runoff pollutants in different phases was evaluated. The AEMC values of runoff pollutants in different phases from urban roads were higher than the ones from urban roofs. The proportions of total dissolved solids, total dissolved nitrogen, and total dissolved phosphorus in total ones for all the catchments were 26.19%-30.91%, 83.29%-90.51%, and 61.54-68.09%, respectively. During rainfall events, the pollutant concentration at the initial stage of rainfall was high and then sharply decreased to a low value. Affected by catchments characterization and rainfall distribution, the highest concentration of road pollutants might appear in the later period of rainfall. Strong correlations were also found among runoffs pollutants in different phases. Total suspended solid could be considered as a surrogate for particulate matters in both road and roof runoff, while dissolved chemical oxygen demand could be regarded as a surrogate for dissolved matters in roof runoff.

  9. Modeling of the Monthly Rainfall-Runoff Process Through Regressions

    Directory of Open Access Journals (Sweden)

    Campos-Aranda Daniel Francisco

    2014-10-01

    Full Text Available To solve the problems associated with the assessment of water resources of a river, the modeling of the rainfall-runoff process (RRP allows the deduction of runoff missing data and to extend its record, since generally the information available on precipitation is larger. It also enables the estimation of inputs to reservoirs, when their building led to the suppression of the gauging station. The simplest mathematical model that can be set for the RRP is the linear regression or curve on a monthly basis. Such a model is described in detail and is calibrated with the simultaneous record of monthly rainfall and runoff in Ballesmi hydrometric station, which covers 35 years. Since the runoff of this station has an important contribution from the spring discharge, the record is corrected first by removing that contribution. In order to do this a procedure was developed based either on the monthly average regional runoff coefficients or on nearby and similar watershed; in this case the Tancuilín gauging station was used. Both stations belong to the Partial Hydrologic Region No. 26 (Lower Rio Panuco and are located within the state of San Luis Potosi, México. The study performed indicates that the monthly regression model, due to its conceptual approach, faithfully reproduces monthly average runoff volumes and achieves an excellent approximation in relation to the dispersion, proved by calculation of the means and standard deviations.

  10. Pollution loads in urban runoff and sanitary wastewater

    International Nuclear Information System (INIS)

    Taebi, Amir; Droste, Ronald L.

    2004-01-01

    While more attention has been paid in recent years to urban point source pollution control through the establishment of wastewater treatment plants in many developing countries, no considerable planning nor any serious measures have been taken to control urban non-point source pollution (urban stormwater runoff). The present study is a screening analysis to investigate the pollution loads in urban runoff compared to point source loads as a first prerequisite for planning and management of receiving water quality. To compare pollutant loads from point and non-point urban sources, the pollutant load is expressed as the weight of pollutant per hectare area per year (kg/ha·year). Unit loads were estimated in stormwater runoff, raw sanitary wastewater and secondary treatment effluents in Isfahan, Iran. Results indicate that the annual pollution load in urban runoff is lower than the annual pollution load in sanitary wastewater in areas with low precipitation but it is higher in areas with high precipitation. Two options, namely, advanced treatment (in lieu of secondary treatment) of sanitary wastewater and urban runoff quality control systems (such as detention ponds) were investigated as controlling systems for pollution discharges into receiving waters. The results revealed that for Isfahan, as a low precipitation urban area, advanced treatment is a more suitable option, but for high precipitation urban areas, urban surface runoff quality control installations were more effective for suspended solids and oxygen-demanding matter controls, and that advanced treatment is the more effective option for nutrient control

  11. Using biofuel tracers to study alternative combustion regimes

    International Nuclear Information System (INIS)

    Mack, J.H.; Flowers, D.L.; Buchholz, B.A.; Dibble, R.W.

    2007-01-01

    Interest in the use of alternative fuels and engines is increasing as the price of petroleum climbs. The inherently higher efficiency of Diesel engines has led to increased adoption of Diesels in Europe, capturing approximately 40% of the new passenger car market. Unfortunately, lower CO 2 emissions are countered with higher nitrogen oxides (NO x ) and particulate matter (PM) emissions and higher noise. Adding oxygenated compounds to the fuel helps reduce PM emissions. However, relying on fuel alone to reduce PM is unrealistic due to economic constraints and difficult due to the emerging PM standards. Keeping peak combustion temperature below 1700 K inhibits NO x formation. Altering the combustion regime to burn at temperatures below the NO x threshold and accept a wide variety of fuels seems like a promising alternative for future engines. Homogeneous charge compression ignition (HCCI) is a possible solution. Fuel and air are well mixed prior to intake into a cylinder (homogeneous charge) and ignition occurs by compression of the fuel-air mixture by the piston. HCCI is rapid and relatively cool, producing little NO x and PM. Unfortunately, it is hard to control since HCCI is initiated by temperature and pressure instead of a spark or direct fuel injection. We investigate biofuel HCCI combustion, and use intrinsically labeled biofuels as tracers of HCCI combustion. Data from tracer experiments are used to improve our combustion modeling

  12. Rainfall-induced runoff from exposed streambed sediments: an important source of water pollution.

    Science.gov (United States)

    Frey, S K; Gottschall, N; Wilkes, G; Grégoire, D S; Topp, E; Pintar, K D M; Sunohara, M; Marti, R; Lapen, D R

    2015-01-01

    When surface water levels decline, exposed streambed sediments can be mobilized and washed into the water course when subjected to erosive rainfall. In this study, rainfall simulations were conducted over exposed sediments along stream banks at four distinct locations in an agriculturally dominated river basin with the objective of quantifying the potential for contaminant loading from these often overlooked runoff source areas. At each location, simulations were performed at three different sites. Nitrogen, phosphorus, sediment, fecal indicator bacteria, pathogenic bacteria, and microbial source tracking (MST) markers were examined in both prerainfall sediments and rainfall-induced runoff water. Runoff generation and sediment mobilization occurred quickly (10-150 s) after rainfall initiation. Temporal trends in runoff concentrations were highly variable within and between locations. Total runoff event loads were considered large for many pollutants considered. For instance, the maximum observed total phosphorus runoff load was on the order of 1.5 kg ha. Results also demonstrate that runoff from exposed sediments can be a source of pathogenic bacteria. spp. and spp. were present in runoff from one and three locations, respectively. Ruminant MST markers were also present in runoff from two locations, one of which hosted pasturing cattle with stream access. Overall, this study demonstrated that rainfall-induced runoff from exposed streambed sediments can be an important source of surface water pollution. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  13. Surface runoff generation in a small watershed covered by sugarcane and riparian forest

    Directory of Open Access Journals (Sweden)

    Rafael Pires Fernandes

    2013-12-01

    Full Text Available Since an understanding of how runoff is generated is of great importance to soil conservation, to water availability and to the management of a watershed, the objective of this study was to understand the generation of surface runoff in a watershed covered by sugarcane and riparian forest. Nine surface runoff plots were set up, evenly distributed on the lower, middle and upper slopes. The lower portion was covered by riparian forest. We showed that the average surface runoff coefficient along the slope in the present study was higher than in other studies under different land uses. Furthermore, the surface runoff was higher under sugarcane compared to the riparian forest, especially after sugarcane harvesting. Besides land cover, other factors such as the characteristics of rainfall events, relief and physical soil characteristics such as soil bulk density and saturated hydraulic conductivity influenced the surface runoff generation.

  14. Quantification of Runoff as Influenced by Morphometric Characteristics in a Rural Complex Catchment

    Science.gov (United States)

    Abdulkareem, Jabir Haruna; Pradhan, Biswajeet; Sulaiman, Wan Nor Azmin; Jamil, Nor Rohaizah

    2018-03-01

    This study addresses the critical scientific question of assessing the relationship between morphometric features and the hydrological factors that increase the risk of flooding in Kelantan River basin, Malaysia. Two hypotheses were developed to achieve this aim, namely: the alternate hypothesis (runoff, is influenced by morphometric characteristics in the study watershed) and the null hypothesis (runoff is not influenced by morphometric characteristics). First, the watershed was delineated into four major catchments, namely: Galas, Pergau, Lebir, and Nenggiri. Next, quantitative morphometric characters such as linear aspects, areal aspects, and relief aspects were determined on each of these catchments. Furthermore, HEC-HMS and flood response analyses were employed to simulate the hydrological response of the catchments. From the results of morphometric analysis, profound spatial changes were observed between runoff features of Kelantan River and the morphometric characteristics. The length of overflow that was related to drainage density and constant channel maintenance was found to be 0.12 in Pergau, 0.04 in both Nenggiri and Lebir, and 0.03 in Galas. Drainage density as influenced by geology and vegetation density was found to be low in all the catchments (0.07-0.24). Results of hydrological response indicated that Lebir, Nenggiri, Galas, and Pergau recorded a flood response factor of 0.75, 0.63, 0.40, and 0.05, respectively. Therefore, Lebir and Nenggiri are more likely to be flooded during a rainstorm. There was no clear indication with regard to the catchment that emerged as the most prevailing in all the morphological features. Hence, the alternate hypothesis was affirmed. This study can be replicated in other catchments with different hydrologic setup.

  15. Alternative kynurenic acid synthesis routes studied in the rat cerebellum

    Directory of Open Access Journals (Sweden)

    Tonali eBlanco Ayala

    2015-05-01

    Full Text Available Kynurenic acid (KYNA, an astrocyte-derived, endogenous antagonist of α7 nicotinic acetylcholine and excitatory amino acid receptors, regulates glutamatergic, GABAergic, cholinergic and dopaminergic neurotransmission in several regions of the rodent brain. Synthesis of KYNA in the brain and elsewhere is generally attributed to the enzymatic conversion of L-kynurenine (L-KYN by kynurenine aminotransferases (KATs. However, alternative routes, including KYNA formation from D-kynurenine (D-KYN by D-amino acid oxidase (DAAO and the direct transformation of kynurenine to KYNA by reactive oxygen species (ROS, have been demonstrated in the rat brain. Using the rat cerebellum, a region of low KAT activity and high DAAO activity, the present experiments were designed to examine KYNA production from L-KYN or D-KYN by KAT and DAAO, respectively, and to investigate the effect of ROS on KYNA synthesis. In chemical combinatorial systems, both L-KYN and D-KYN interacted directly with peroxynitrite (ONOO- and hydroxyl radicals (OH•, resulting in the formation of KYNA. In tissue homogenates, the non-specific KAT inhibitor aminooxyacetic acid (AOAA; 1 mM reduced KYNA production from L-KYN and D-KYN by 85.1 ± 1.7% and 27.1 ± 4.5%, respectively. Addition of DAAO inhibitors (benzoic acid, kojic acid or 3-methylpyrazole-5-carboxylic acid; 5 µM each attenuated KYNA formation from L-KYN and D-KYN by ~35% and ~66%, respectively. ONOO- (25 µM potentiated KYNA production from both L-KYN and D-KYN, and these effects were reduced by DAAO inhibition. AOAA attenuated KYNA production from L-KYN + ONOO- but not from D-KYN + ONOO-. In vivo, extracellular KYNA levels increased rapidly after perfusion of ONOO- and, more prominently, after subsequent perfusion with L-KYN or D-KYN (100 µM. Taken together, these results suggest that different mechanisms are involved in KYNA production in the rat cerebellum, and that, specifically, DAAO and ROS can function as alternative routes

  16. Time focused measurements of roof runoff quality

    International Nuclear Information System (INIS)

    Schriewer, A.; Horn, H.; Helmreich, B.

    2008-01-01

    Runoff properties and their changes during runoff of a 14 year old zinc roof were investigated. Zinc, lead, cadmium, pH value, rain intensity and electric conductivity have been measured for a period of one year. A runoff rate of 3.73 g/m 2 a and a volume weighted mean zinc concentration of 4.9 mg/L were determined. First flush behaviour was observed in 93% of runoff events. Low rain intensities are correlating with higher zinc concentrations in runoff, whereas the duration of antecedent dry periods could not directly be linked with initial zinc concentrations

  17. Supplementary study about the ATC generic project. Alternative storage for encapsulated fuel

    International Nuclear Information System (INIS)

    Canadas Martinez, I.

    2010-01-01

    The objective of this study is to present the alternatives for a complementary installation and facilitate the decision making on the best solution, keeping many determining factors in mind. Two are the alternatives studied: supplementary storage, similar to the Trillo Nuclear Power Plant, and outdoor storage, similar to the Asco and Jose Cabrera Nuclear Power Plants.

  18. A hydrological-modeling study of the impact of land use/land cover and climate change on runoff in a watershed in the western Brazilian Amazonia | Um estudo de modelagem hidrológica do impacto do uso da terra / cobertura da terra e mudanças climáticas ..

    Directory of Open Access Journals (Sweden)

    Ranyere Silva Nóbrega

    2016-05-01

    Full Text Available In this work we investigate the effect of land use and land cover in the Jamari sub river basin, located in the Brazilian Amazonian. The objective is twofold: 1 to study the impact of deforestation and climate change on the basin's runoff, and 2 to test the feasibility of using a semi-distributed hydrological model  for studying runoff of a low-slope river basin such as Jamari. We use a wide variety of data such as Landsat imagery, digital elevation data as well as conventional precipitation and near-surface data. We defined scenarios ranging from a completely forested basin to a completely man-modified one. In addition, we tested realistic scenarios for the ongoing deforestation process with 20% and 30% deforestation and tested scenarios hypothetic for climate change.  Our scenarios suggest that for extreme and realistic scenarios there is an increase of runoff when deforestation occurs, since less water is intercepted in canopy, evapotranspiration and groundwater tends to decrease with deforestation. In climate change scenarios, increase temperature and precipitation tends to increase evapotranspiration and runoff and, increase temperature and decrease precipitation tend to increase evapotranspiration and decrease runoff and groundwater. The results suggest that Semi-distributed Land Use-based Runoff Processes (SLURP is suitable for use in the Jamari sub river basin with the advantage of being a light model, in terms of internal parameters. The proposed methodology is suitable for use in other basins of the region.

  19. ESTIMATION OF RUNOFF IN AN UNGAUGED RURAL WATERSHED, TAMILNADU STATE, INDIA

    OpenAIRE

    MANOHARAN, A; MURUGAPPAN, A

    2012-01-01

    Runoff estimation in ungauged catchment is a challenge for the hydrological engineers and planners. For any hydrological study on an ungauged watershed, a methodology has to be appropriately selected for the determination of runoff at its outlet. Several methods have been used to estimate the runoff from a watershed. GIS and Remote Sensing techniques seem to be accurate and sensitive that includes several important properties of watershed namely, soil permeability, landuse and antecedent soil...

  20. Urban rainwater runoff quantity and quality: a potential endogenous resource in cities?

    OpenAIRE

    Angrill Toledo, Sara; Petit Boix, Anna; Morales Pinzon, Tito; Josa Garcia-Tornel, Alejandro; Rieradevall Pons, Joan; Gabarrell Durany, Xavier

    2017-01-01

    Rainwater harvesting might help to achieve self-sufficiency, but it must comply with health standards. We studied the runoff quantity and quality harvested from seven urban surfaces in a university campus in Barcelona according to their use (pedestrian or motorized mobility) and materials (concrete, asphalt and slabs). An experimental rainwater harvesting system was used to collect the runoff resulting from a set of rainfall events. We estimated the runoff coefficient and initial abstraction ...

  1. Earthworms and tree roots: A model study of the effect of preferential flow paths on runoff generation and groundwater recharge in steep, saprolitic, tropical lowland catchments

    Science.gov (United States)

    Cheng, Yanyan; Ogden, Fred L.; Zhu, Jianting

    2017-07-01

    Preferential flow paths (PFPs) affect the hydrological response of humid tropical catchments but have not received sufficient attention. We consider PFPs created by tree roots and earthworms in a near-surface soil layer in steep, humid, tropical lowland catchments and hypothesize that observed hydrological behaviors can be better captured by reasonably considering PFPs in this layer. We test this hypothesis by evaluating the performance of four different physically based distributed model structures without and with PFPs in different configurations. Model structures are tested both quantitatively and qualitatively using hydrological, geophysical, and geochemical data both from the Smithsonian Tropical Research Institute Agua Salud Project experimental catchment(s) in Central Panama and other sources in the literature. The performance of different model structures is evaluated using runoff Volume Error and three Nash-Sutcliffe efficiency measures against observed total runoff, stormflows, and base flows along with visual comparison of simulated and observed hydrographs. Two of the four proposed model structures which include both lateral and vertical PFPs are plausible, but the one with explicit simulation of PFPs performs the best. A small number of vertical PFPs that fully extend below the root zone allow the model to reasonably simulate deep groundwater recharge, which plays a crucial role in base flow generation. Results also show that the shallow lateral PFPs are the main contributor to the observed high flow characteristics. Their number and size distribution are found to be more important than the depth distribution. Our model results are corroborated by geochemical and geophysical observations.

  2. Fill and spill drives runoff connectivity over frozen ground

    Science.gov (United States)

    Coles, A. E.; McDonnell, J. J.

    2018-03-01

    Snowmelt-runoff processes on frozen ground are poorly understood at the hillslope scale. This is especially true for hillslopes on the northern Great Plains of North America where long periods of snow-covered frozen ground with very shallow slopes mask any spatial patterns and process controls on connectivity and hillslope runoff generation. This study examines a 4.66 ha (46,600 m2) hillslope on the northern Great Plains during the 2014 spring snowmelt season to explore hillslope runoff processes. Specifically, we explore the spatial patterns of runoff production source areas and examine how surface topography and patterns of snow cover, snow water equivalent, soil water content, and thawed layer depth - which we measured on a 10 m grid across our 46,600 m2 hillslope - affect melt water partitioning and runoff connectivity. A key question was whether or not the controls on connectivity are consistent with the fill and spill mechanism found in rain-dominated and unfrozen soil domains. The contrast between the slow infiltration rates into frozen soil and the relatively fast rates of snowmelt delivery to the soil surface resulted in water accumulation in small depressions under the snowpack. Consequently, infiltration was minimal over the 12 day melt period. Instead, nested filling of micro- and meso-depressions was followed by macro-scale, whole-slope spilling. This spilling occurred when large patches of ponded water exceeded the storage capacity behind downslope micro barriers in the surface topography, and flows from them coalesced to drive a rapid increase in runoff at the hillslope outlet. These observations of ponded water and flowpaths followed mapable fill and spill locations based on 2 m resolution digital topographic analysis. Interestingly, while surface topography is relatively unimportant under unfrozen conditions at our site because of low relief and high infiltrability, surface topography shows episodically critical importance for connectivity and

  3. EVALUATION OF RAINFALL-RUNOFF MODELS FOR MEDITERRANEAN SUBCATCHMENTS

    Directory of Open Access Journals (Sweden)

    A. Cilek

    2016-06-01

    Full Text Available The development and the application of rainfall-runoff models have been a corner-stone of hydrological research for many decades. The amount of rainfall and its intensity and variability control the generation of runoff and the erosional processes operating at different scales. These interactions can be greatly variable in Mediterranean catchments with marked hydrological fluctuations. The aim of the study was to evaluate the performance of rainfall-runoff model, for rainfall-runoff simulation in a Mediterranean subcatchment. The Pan-European Soil Erosion Risk Assessment (PESERA, a simplified hydrological process-based approach, was used in this study to combine hydrological surface runoff factors. In total 128 input layers derived from data set includes; climate, topography, land use, crop type, planting date, and soil characteristics, are required to run the model. Initial ground cover was estimated from the Landsat ETM data provided by ESA. This hydrological model was evaluated in terms of their performance in Goksu River Watershed, Turkey. It is located at the Central Eastern Mediterranean Basin of Turkey. The area is approximately 2000 km2. The landscape is dominated by bare ground, agricultural and forests. The average annual rainfall is 636.4mm. This study has a significant importance to evaluate different model performances in a complex Mediterranean basin. The results provided comprehensive insight including advantages and limitations of modelling approaches in the Mediterranean environment.

  4. Impact of possible climate changes on river runoff under different natural conditions

    Science.gov (United States)

    Gusev, Yeugeniy M.; Nasonova, Olga N.; Kovalev, Evgeny E.; Ayzel, Georgy V.

    2018-06-01

    The present study was carried out within the framework of the International Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) for 11 large river basins located in different continents of the globe under a wide variety of natural conditions. The aim of the study was to investigate possible changes in various characteristics of annual river runoff (mean values, standard deviations, frequency of extreme annual runoff) up to 2100 on the basis of application of the land surface model SWAP and meteorological projections simulated by five General Circulation Models (GCMs) according to four RCP scenarios. Analysis of the obtained results has shown that changes in climatic runoff are different (both in magnitude and sign) for the river basins located in different regions of the planet due to differences in natural (primarily climatic) conditions. The climatic elasticities of river runoff to changes in air temperature and precipitation were estimated that makes it possible, as the first approximation, to project changes in climatic values of annual runoff, using the projected changes in mean annual air temperature and annual precipitation for the river basins. It was found that for most rivers under study, the frequency of occurrence of extreme runoff values increases. This is true both for extremely high runoff (when the projected climatic runoff increases) and for extremely low values (when the projected climatic runoff decreases).

  5. Comparative assessment of predictions in ungauged basins – Part 3: Runoff signatures in Austria

    Directory of Open Access Journals (Sweden)

    A. Viglione

    2013-06-01

    Full Text Available This is the third of a three-part paper series through which we assess the performance of runoff predictions in ungauged basins in a comparative way. Whereas the two previous papers by Parajka et al. (2013 and Salinas et al. (2013 assess the regionalisation performance of hydrographs and hydrological extremes on the basis of a comprehensive literature review of thousands of case studies around the world, in this paper we jointly assess prediction performance of a range of runoff signatures for a consistent and rich dataset. Daily runoff time series are predicted for 213 catchments in Austria by a regionalised rainfall–runoff model and by Top-kriging, a geostatistical estimation method that accounts for the river network hierarchy. From the runoff time-series, six runoff signatures are extracted: annual runoff, seasonal runoff, flow duration curves, low flows, high flows and runoff hydrographs. The predictive performance is assessed in terms of the bias, error spread and proportion of unexplained spatial variance of statistical measures of these signatures in cross-validation (blind testing mode. Results of the comparative assessment show that, in Austria, the predictive performance increases with catchment area for both methods and for most signatures, it tends to increase with elevation for the regionalised rainfall–runoff model, while the dependence on climate characteristics is weaker. Annual and seasonal runoff can be predicted more accurately than all other signatures. The spatial variability of high flows in ungauged basins is the most difficult to estimate followed by the low flows. It also turns out that in this data-rich study in Austria, the geostatistical approach (Top-kriging generally outperforms the regionalised rainfall–runoff model.

  6. Alternative policy study. Environment and energy in Europe and Central Asia 1990-2010. Energy-related environmental impacts of policy scenarios. GEO 2000 alternative policy study

    International Nuclear Information System (INIS)

    Van Vuuren, D.P.; Bakkes, J.A.

    2000-01-01

    The GEO-2000 study into alternative policy options for Europe and Central Asia focuses on energy use as an important driver for environmental problems across the region. The problems analyzed are climate change, acidification, summer smog, urban air pollution and risks of reactor accidents associated with nuclear power generation. The analysis includes the effects on biodiversity and population health. It considers the question of what can be achieved by moderate measures, and whether this will be enough. Similar Geo-2000 region-specific studies on alternative policies have been compiled other world regions. This report outliners the general methodology for these reports

  7. Can Alternative Education Increase Children's Early School Engagement? A Longitudinal Study from Kindergarten to Third Grade

    Science.gov (United States)

    de Bilde, Jerissa; Van Damme, Jan; Lamote, Carl; De Fraine, Bieke

    2013-01-01

    The current study examines the impact of alternative education on children's early school engagement in terms of school enjoyment and independent participation. A sample of 2,776 children from traditional (e.g., mainstream) and alternative (Freinet and Waldorf) Flemish schools was followed from their 3rd year of kindergarten until 3rd grade. The…

  8. Generating alternative alignments in terrain suitability studies for environmental impact assessments of linear developments

    CSIR Research Space (South Africa)

    Van Deventer, Heidi

    2010-08-01

    Full Text Available (EIA). Though legislation requires a screening or scoping of alternative options prior to the EIA, the use of Geographical Information Systems (GIS) is seldom used in generating alternatives through a Terrain Suitability Study (TSS). The inclusion of a...

  9. Characterizations of the first flush in storm water runoff from an urban roadway.

    Science.gov (United States)

    Lee, B C; Matsui, S; Shimizu, Y; Matsuda, T

    2005-07-01

    Storm water runoff from urban roadways contains anthropogenic pollutants, which are mainly generated from traffic-related activities. The purpose of this study was to evaluate the characteristics of pollutants from the roadway runoff as well as first flush effects. Storm water runoff was sampled during five storm events from the experimental site in Otsu, Shiga, Japan. From the hydrographs and pollutographs for the roadway runoff, the concentration of pollutants increased with increasing runoff flow in the low flow rate event, but did not significantly increase in the high flow rate event. Moreover, according to the analysis of cumulative pollutant mass versus runoff volume curves from five storm events, the first 50% of the runoff volume transported 62% of TOC and Mo, 60% of SS, 59% of Fe, Mn and Cu, 58% of Ni, 57% of Cd and Pb, 56% of Al, 55% of Zn, and 54% of Cr, as the mean values. The first 30% and 80% of the runoff volume also transported 34-43% mass of the pollutants and 82-88% mass of the pollutants, respectively. This study for storm water runoff may also provide useful information to correctly design treatment facilities, such as detention tanks and ponds, filtration and adsorption systems.

  10. [Hydrology and pollution characteristics of urban runoff: Beijing as a sample].

    Science.gov (United States)

    Dong, Xin; Du, Peng-Fei; Li, Zhi-Yi; Yu, Zheng-Rong; Wang, Rui; Huang, Jin-Liang

    2008-03-01

    The purpose of this study is identification and characterization of hydrological process of urban runoff, as well as concentration variation of pollutants in it. Samples were collected in 4 rainfall events in Beijing from Jun. 2006 to Aug. 2006. Hydrology and pollution of the rainfall-runoff process were analyzed on roof and road. Study results show that the shapes of hydrological curves of runoff, despite for a 5 - 20 min delay and a milder tendency, are similar to rainfall curves. Runoff coefficients of roof are 0.80 - 0.98, while 0.87 - 0.97 of road. Event mean concentrations (EMC) of pollutants are influenced by build-up and wash-off features, which leads to a higher concentration in road runoff than in roof runoff. Major pollutants that excess the water quality standards are COD, TN, and TP. Evident correlations (> 0.1) are found between pollutants. Correlation with particles are higher for COD and SO4(2-) (> 0.5), while lower for nutrients (pollutant variety, types of land covers, and rainfall intensity. FFE are found more intense in SS, more frequently in road runoff, and more difficult to form for COD and nutrients with low rainfall intensity. Therefore, control of first period of runoff would be an effective approach for runoff management in Beijing.

  11. Random Modeling of Daily Rainfall and Runoff Using a Seasonal Model and Wavelet Denoising

    Directory of Open Access Journals (Sweden)

    Chien-ming Chou

    2014-01-01

    Full Text Available Instead of Fourier smoothing, this study applied wavelet denoising to acquire the smooth seasonal mean and corresponding perturbation term from daily rainfall and runoff data in traditional seasonal models, which use seasonal means for hydrological time series forecasting. The denoised rainfall and runoff time series data were regarded as the smooth seasonal mean. The probability distribution of the percentage coefficients can be obtained from calibrated daily rainfall and runoff data. For validated daily rainfall and runoff data, percentage coefficients were randomly generated according to the probability distribution and the law of linear proportion. Multiplying the generated percentage coefficient by the smooth seasonal mean resulted in the corresponding perturbation term. Random modeling of daily rainfall and runoff can be obtained by adding the perturbation term to the smooth seasonal mean. To verify the accuracy of the proposed method, daily rainfall and runoff data for the Wu-Tu watershed were analyzed. The analytical results demonstrate that wavelet denoising enhances the precision of daily rainfall and runoff modeling of the seasonal model. In addition, the wavelet denoising technique proposed in this study can obtain the smooth seasonal mean of rainfall and runoff processes and is suitable for modeling actual daily rainfall and runoff processes.

  12. Study of Effective Alternative Education Programs: Final Grant Report

    Science.gov (United States)

    Quinn, Mary Magee; Poirier, Jeffrey M.

    2007-01-01

    This report presents findings of a study conducted to identify the components of systems that effectively meet the diverse, ever changing needs of children with disabilities for whom traditional school settings do not work. A secondary goal of this study was to develop a conceptually clear and empirically grounded definition of alternative…

  13. [Runoff loss of soil mineral nitrogen and its relationship with grass coverage on Loess slope land].

    Science.gov (United States)

    Zhang, Yali; Li, Huai'en; Zhang, Xingchang; Xiao, Bo

    2006-12-01

    In a simulated rainfall experiment on Loess slope land, this paper determined the rainfall, surface runoff and the effective depth of interaction (EDI) between rainfall and soil mineral nitrogen, and studied the effects of grass coverage on the EDI and the runoff loss of soil mineral nitrogen. The results showed that with the increase of EDI, soil nitrogen in deeper layers could be released into surface runoff through dissolution and desorption. The higher the grass coverage, the deeper the EDI was. Grass coverage promoted the interaction between surface runoff and surface soil. On the slope land with 60%, 80% and 100% of grass coverage, the mean content of runoff mineral nitrogen increased by 34.52%, 32.67% and 6.00%, while surface runoff decreased by 4.72%, 9.84% and 12.89%, and eroded sediment decreased by 83.55%, 87.11% and 89.01%, respectively, compared with bare slope land. The total runoff loss of soil mineral nitrogen on the lands with 60%, 80%, and 100% of grass coverage was 95.73%, 109.04%, and 84.05% of that on bare land, respectively. Grass cover had dual effects on the surface runoff of soil mineral nitrogen. On one hand, it enhanced the influx of soil mineral nitrogen to surface runoff, and on the other hand, it markedly decreased the runoff, resulting in the decrease of soil mineral nitrogen loss through runoff and sediment. These two distinct factors codetermined the total runoff loss of soil mineral nitrogen.

  14. Analysis of long-term trends (1950–2009) in precipitation, runoff and runoff coefficient in major urban watersheds in the United States

    International Nuclear Information System (INIS)

    Velpuri, N M; Senay, G B

    2013-01-01

    This study investigates the long-term trends in precipitation, runoff and runoff coefficient in major urban watersheds in the United States. The seasonal Mann–Kendall trend test was performed on monthly precipitation, runoff and runoff coefficient data from 1950 to 2009 obtained from 62 urban watersheds covering 21 major urban centers in the United States. The results indicate that only five out of 21 urban centers in the United States showed an uptrend in precipitation. Twelve urban centers showed an uptrend in runoff coefficient. However, six urban centers did not show any trend in runoff coefficient, and three urban centers showed a significant downtrend. The highest rate of change in precipitation, runoff and runoff coefficient was observed in the Houston urban watershed. Based on the results obtained, we also attributed plausible causes for the trends. Our analysis indicated that while a human only influence is observed in most of the urban watersheds, a combined climate and human influence is observed in the central United States. (letter)

  15. Hydrology in a mediterranean mountain environment. The Vallcebre research catchment (north eastern Spain) II. Rainfall-runoff relationships and runoff processes

    International Nuclear Information System (INIS)

    Latron, J.; Solar, M.; Nord, G.; Llorens, P.; Gallart, F.

    2009-01-01

    Hydrological response and runoff processes have been studied in the Vallcebre research basins (North Eastern Spain) for almost 20 years. Results obtained allowed to build a more complete perceptual model of the hydrological functioning of Mediterranean mountains basins. On a seasonal and monthly scale, there was no simple relationship between rainfall and runoff depths. Monthly rainfall and runoff values revealed the existence of a threshold in the relationship between rainfall and runoff depths. At the event scale, the storm-flow coefficient had a clear seasonal pattern. The effect of the water table position on how rainfall and runoff volumes relate was observed. Examination of soil water potential and water table dynamics during representative floods helped to identify 3 types of characteristic hydrological behaviour during the year. Under dry conditions, runoff was generated essentially as infiltration excess runoff in low permeable areas, whereas saturation excess runoff dominated during wetting-up and wet conditions. During wetting-up transition, saturated areas resulted from the development of scattered perched water tables, whereas in wet conditions they were linked to the rise of the shallow water table. (Author) 8 refs.

  16. Human impacts on runoff regime of middle and lower Yellow River

    Directory of Open Access Journals (Sweden)

    Yan-fang Sang

    2011-03-01

    Full Text Available In this study, the 54-year (1950 to 2003 monthly runoff series from February, April, August, and November, as well as the annual runoff series, measured at both Huayuankou and Lijin hydrological stations were chosen as representative data, and the continuous wavelet transform (CWT was applied to analyze the impacts of human activities on the runoff regime of the middle and lower Yellow River. A point of change in 1970 was first determined, and the observed series before 1970 were considered natural runoff while those after 1970 were restored according to linear trends. Then, the CWT was applied to both the observed and restored runoff series to reveal their variations at multi-temporal scales, including the five temporal ranges of 1–4, 6–8, 9–12, 16–22, and 22–30 years, and the trend at the temporal scale of 54 years. These analysis results are compared and discussed in detail. In conclusion, because of the impacts of human activities, there have been significant changes in the runoff regime in the middle and lower Yellow River since 1970. The decaying tendency of annual runoff has become more pronounced, and the inner-annual distribution of runoff has changed, but human activities have had little impact on the periodic characteristics of runoff.

  17. Long-term characterization of residential runoff and assessing potential surrogates of fecal indicator organisms.

    Science.gov (United States)

    Reano, Dane C; Haver, Darren L; Oki, Lorence R; Yates, Marylynn V

    2015-05-01

    Investigations into the microbiological impacts of urban runoff on receiving water bodies, especially during storm conditions, have yielded general paradigms that influence runoff abatement and control management strategies. To determine whether these trends are present in other runoff sources, the physical, chemical, and microbiological components of residential runoff from eight neighborhoods in Northern and Southern California were characterized over the course of five years. Sampling occurred regularly and during storm events, resulting in 833 data sets. Analysis of runoff data assisted in characterizing residential runoff, elucidating differences between dry and storm conditions, and identifying surrogates capable of assessing microbiological quality. Results indicate that although microbial loading increases during storm events similar to urban runoff, annual microbial loading in these study sites principally occurs during dry conditions (24% storm, 76% dry). Generated artificial neural network and multiple linear regression models assessed surrogate performance by accurately predicting Escherichia coli concentrations from validation data sets (R(2) = 0.74 and 0.77, respectively), but required input from other fecal indicator organism (FIO) variables to maintain performance (R(2) = 0.27 and 0.18, respectively, without FIO). This long-term analysis of residential runoff highlights characteristics distinct from urban runoff and establishes necessary variables for determining microbiological quality, thus better informing future management strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Surface water quality in a water run-off canal system: A case study in Jubail Industrial City, Kingdom of Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Zia Mahmood Siddiqi

    2016-06-01

    Full Text Available Water quality in a run-off canal system in an industrial area was evaluated for a range of physical and chemical properties comprising trace metals (including mercury (Hg, chromium (Cr, iron (Fe, manganese (Mn, salinity, pH, turbidity, total dissolved solids, total suspended solids, chemical oxygen demand (COD, and dissolved oxygen. High concentrations of potassium (K (1.260–2.345 mg/l and calcium (Ca (19.170–35510 mg/l demonstrated that the salinity in the water was high, which indicates that industrial effluents from fertilizer manufacturing and Chlor-alkali units are being discharged into the canal system. Almost all the metal concentrations in water and sediment were within the thresholds established by the local regulatory body. Concentrations of Cr (0.0154–0.0184 mg/l, Mn (0.0608–0.199 mg/l, Fe (0.023–0.035 mg/l, COD (807–916 mg/l, and turbidity (633 ± 15–783 ± 22 NTU were high where the canal discharges into the Persian Gulf; these discharges may compromise the health of the aquatic ecosystem. There is concern about the levels of Hg in water (0.00135–0.0084 mg/l, suspended sediment (0.00308–0.0096 mg/l, and bed sediment (0.00172–0.00442 mg/l because of the bio-accumulative nature of Hg. We also compared the total Hg concentrations in fish from Jubail, and two nearby cities. Hg contents were highest in fish tissues from Jubail. This is the first time that heavy metal pollution has been assessed in this water run-off canal system; information about Hg is of particular interest and will form the basis of an Hg database for the area that will be useful for future investigations.

  19. Alternative Policy Study: Environment and energy in Europe and Central Asia 1990-2010. Energy-related environmental impacts of policy scenarios GEO-2000 alternative policy study

    NARCIS (Netherlands)

    Vuuren DP van; Bakkes JA; United Nations Environment; MNV

    2000-01-01

    The GEO-2000 study into alternative policy options for Europe and Central Asia focuses on energy use as an important driver for environmental problems across the region. The problems analyzed are climate change, acidification, summer smog, urban air pollution and risks of reactor accidents

  20. Comparative study of Waste Isolation Pilot Plant (WIPP) transportation alternatives

    International Nuclear Information System (INIS)

    1994-02-01

    WIPP transportation studies in the Final Supplement Environmental Impact Statement for WIPP are the baseline for this report. In an attempt to present the most current analysis, this study incorporates the most relevant data available. The following three transportation options are evaluated for the Disposal Phase, which is assumed to be 20 years: Truck shipments, consisting of a tractor and trailer, with three TRUPACT-IIs or one RH-72B; Regular commercial train shipments consisting of up to three railcars carrying up to 18 TRUPACT-IIs or up to six RH-72Bs; Dedicated train shipments consisting of a locomotive, an idle car, railcars carrying 18 TRUPACT-IIs or six RH-72Bs, another idle car, and a caboose or passenger car with an emergency response specialist. No other cargo is carried. This report includes: A consideration of occupational and public risks and exposures, and other environmental impacts; A consideration of emergency response capabilities; and An extimation of comparative costs

  1. Comparative study of Waste Isolation Pilot Plant (WIPP) transportation alternatives

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    WIPP transportation studies in the Final Supplement Environmental Impact Statement for WIPP are the baseline for this report. In an attempt to present the most current analysis, this study incorporates the most relevant data available. The following three transportation options are evaluated for the Disposal Phase, which is assumed to be 20 years: Truck shipments, consisting of a tractor and trailer, with three TRUPACT-IIs or one RH-72B; Regular commercial train shipments consisting of up to three railcars carrying up to 18 TRUPACT-IIs or up to six RH-72Bs; Dedicated train shipments consisting of a locomotive, an idle car, railcars carrying 18 TRUPACT-IIs or six RH-72Bs, another idle car, and a caboose or passenger car with an emergency response specialist. No other cargo is carried. This report includes: A consideration of occupational and public risks and exposures, and other environmental impacts; A consideration of emergency response capabilities; and An extimation of comparative costs.

  2. Study on storage energy devices: supercapacitors, a green alternative

    OpenAIRE

    Rancaño Fernandez, Ariadna

    2011-01-01

    Nowadays, it is increasingly common to hear about environmental issues. This fact keep us to continually try to improve energy optimization, either through new storage devices that pollute less or improvements in the environmental energy generation systems. Recent new types of devices under study are those called supercapacitors. Supercapacitors are electronic devices able to store charge in form of electrical energy. This energy is stored as an electric field, so supercapacitors are less pol...

  3. Numerical study of canister filters with alternatives filter cap configurations

    Science.gov (United States)

    Mohammed, A. N.; Daud, A. R.; Abdullah, K.; Seri, S. M.; Razali, M. A.; Hushim, M. F.; Khalid, A.

    2017-09-01

    Air filtration system and filter play an important role in getting a good quality air into turbo machinery such as gas turbine. The filtration system and filter has improved the quality of air and protect the gas turbine part from contaminants which could bring damage. During separation of contaminants from the air, pressure drop cannot be avoided but it can be minimized thus helps to reduce the intake losses of the engine [1]. This study is focused on the configuration of the filter in order to obtain the minimal pressure drop along the filter. The configuration used is the basic filter geometry provided by Salutary Avenue Manufacturing Sdn Bhd. and two modified canister filter cap which is designed based on the basic filter model. The geometries of the filter are generated by using SOLIDWORKS software and Computational Fluid Dynamics (CFD) software is used to analyse and simulates the flow through the filter. In this study, the parameters of the inlet velocity are 0.032 m/s, 0.063 m/s, 0.094 m/s and 0.126 m/s. The total pressure drop produce by basic, modified filter 1 and 2 is 292.3 Pa, 251.11 Pa and 274.7 Pa. The pressure drop reduction for the modified filter 1 is 41.19 Pa and 14.1% lower compared to basic filter and the pressure drop reduction for modified filter 2 is 17.6 Pa and 6.02% lower compared to the basic filter. The pressure drops for the basic filter are slightly different with the Salutary Avenue filter due to limited data and experiment details. CFD software are very reliable in running a simulation rather than produces the prototypes and conduct the experiment thus reducing overall time and cost in this study.

  4. [Total pollution features of urban runoff outlet for urban river].

    Science.gov (United States)

    Luo, Hong-Bing; Luo, Lin; Huang, Gu; He, Qiang; Liu, Ping

    2009-11-01

    The urban stormwater runoff discharged to urban river, especially to rainfall source river, cannot be ignored. In this study, the Futian River watershed in Shenzhen city in a typical southern city of China is taken as the research object. In order to guide the pollution control for urban river, the eighteen rainfall events were monitored, and the total pollution features of the urban runoff outlet for this urban river were analyzed and discussed by using the process of pollutographs, the identifying to first flush, event mean concentration (EMC), etc. Results show that the concentrations of COD, SS, TN, TP and BOD5 are ten times more than the grade V of the environmental quality standards for surface water during the runoff time; the pollution caused by heavy metals (Cr, Ge, Cu, Hg and As) in runoff at a typical rainfall event is serious; the average and range of pollutant concentration at this runoff outlet in study area are evidently higher than at Shapingba in Chongqing city of China and at Silerwood in Canada, but are lower than at Shilipu in Wuhan city of China. The first flushes of COD, SS, BOD5, especially COD and SS, are evident, but the TN and TP are not. The average EMC of COD, TN, TP and BOD5 are 224.14, 571.15, 5.223, 2.04, 143.5 mg/L, respectively. To some extent, the EMC of COD is about two times of the value of the near cities, Macao and Zhuhai. The EMC of TN and TP are obviously higher than Beijing, Guangzhou and Shanghai. To compared with foreign counties, the EMC of the study area in Shenzhen is obviously much higher than the cities of Korean, USA and Canada. So the total pollution caused by the urban surface runoff in study area is serious and necessary to be treated.

  5. Cogeneration technology alternatives study. Volume 1: Summary report

    Science.gov (United States)

    1980-01-01

    Data and information in the area of advanced energy conversion systems for industrial congeneration applications in the 1985-2000 time period was studied. Six current and thirty-one advanced energy conversion systems were defined and combined with appropriate balance-of-plant equipment. Twenty-six industrial processes were selected from among the high energy consuming industries to serve as a framework for the study. Each conversion system was analyzed as a cogenerator with each industrial plant. Fuel consumption, costs, and environmental intrusion were evaluated and compared to corresponding traditional values. Various cogeneration strategies were analyzed and both topping and bottoming (using industrial by-product heat) applications were included. The advanced energy conversion technologies indicated reduced fuel consumption, costs, and emissions. Typically fuel energy savings of 10 to 25 percent were predicted compared to traditional on-site furnaces and utility electricity. With the variety of industrial requirements, each advanced technology had attractive applications. Overall, fuel cells indicated the greatest fuel energy savings and emission reductions. Gas turbines and combined cycles indicated high overall annual cost savings. Steam turbines and gas turbines produced high estimated returns. In some applications, diesels were most efficient. The advanced technologies used coal-derived fuels, or coal with advanced fluid bed combustion or on-site gasification systems.

  6. The Firstflush of Pollutants in Surface Runoff

    OpenAIRE

    Pejman Razi; Amir Taebi

    2005-01-01

    One of the factors impacting quality of water resources is pollution due to urban storm runoff during first stage of storm runoff and is commonly called "firsflush". At this stage the pollution load is rather high. However, if this pollution is properly controlled and managed, the size of the required treatment facilities will be considerably reduced. The surface runoff pollution in the city of Isfahan is high and necessitates the implementation of some control system. For this purpose, ten r...

  7. Complementary and Alternative Medicine: A Cross-Sectional Observational Study in Pediatric Inpatients.

    Science.gov (United States)

    Dhankar, Mukesh

    2018-01-01

    The aim was to study the prevalence of complementary and alternative medicine use in acutely sick hospitalized children and factors associated with it. This is a cross-sectional, hospital-based study in a tertiary care center of Delhi, India. Children admitted to a pediatric unit during the study period were assessed using a specially designed questionnaire. Out of the total 887 admitted children, 161 (18.1%) were using complementary and alternate medicine in one form or another. Of these, 113 (70.2%) were using complementary and alternate medicine for the current illness directly leading to admission and the remaining 48 (29.8%) had used complementary and alternate medicine in past. The common complementary and alternate medicine use observed in our study was combined ayurveda and spiritual approach (25.5%), ayurveda (24.8%), spiritual (21.7%), homeopathic (13%), and 47.2% of children were using spiritual approach in form of Jhada (tying piece of cloth on arm or leg or keeping a knife by the side of child). The significant factors associated with complementary and alternate medicine use were younger age, female gender, and father being employed. Complementary and alternate medicine is commonly used even in acutely sick children.

  8. ALTERNATIVE AND ENHANCED CHEMICAL CLEANING: BASIC STUDIES RESULTS FY2010

    Energy Technology Data Exchange (ETDEWEB)

    King, W.; Hay, M.

    2011-01-24

    In an effort to develop and optimize chemical cleaning methods for the removal of sludge heels from High Level Waste tanks, solubility tests have been conducted using nonradioactive, pure metal phases. The metal phases studied included the aluminum phase gibbsite and the iron phases hematite, maghemite, goethite, lepidocrocite, magnetite, and wustite. Many of these mineral phases have been identified in radioactive, High Level Waste sludge at the Savannah River and Hanford Sites. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids and a variety of other complexing organic acids. The results of the solubility tests indicate that mixtures of oxalic acid with either nitric or sulfuric acid are the most effective cleaning solutions for the dissolution of the primary metal phases in sludge waste. Based on the results, optimized conditions for hematite dissolution in oxalic acid were selected using nitric or sulfuric acid as a supplemental proton source. Electrochemical corrosion studies were also conducted (reported separately; Wiersma, 2010) with oxalic/mineral acid mixtures to evaluate the effects of these solutions on waste tank integrity. The following specific conclusions can be drawn from the test results: (1) Oxalic acid was shown to be superior to all of the other organic acids evaluated in promoting the dissolution of the primary sludge phases. (2) All iron phases showed similar solubility trends in oxalic acid versus pH, with hematite exhibiting the lowest solubility and the slowest dissolution. (3) Greater than 90% hematite dissolution occurred in oxalic/nitric acid mixtures within one week for two hematite sources and within three weeks for a third hematite sample with a larger average particle size. This dissolution rate appears acceptable for waste tank cleaning applications. (4) Stoichiometric dissolution of iron phases in oxalic acid (based on the oxalate concentration) and the formation of the preferred 1:1 Fe to oxalate complex

  9. Alternative Enhanced Chemical Cleaning Basic Studies Results FY09

    Energy Technology Data Exchange (ETDEWEB)

    Hay, M.; King, W.

    2010-05-05

    Due to the need to close waste storage tanks, chemical cleaning methods are needed for the effective removal of the heels. Oxalic acid is the preferred cleaning reagent for sludge heel dissolution, particularly for iron-based sludge, due to the strong complexing strength of the oxalate. However, the large quantity of oxalate added to the tank farm from oxalic acid based chemical cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acid systems may be required for specific waste components with low solubility in oxalic acid and as a means to reduce oxalic acid usage in general. Solubility tests were conducted using non-radioactive, pure metal phases known to be the primary phases present in High Level Waste sludge. The metal phases studied included the aluminum phases gibbsite and boehmite and the iron phases magnetite and hematite. Hematite and boehmite are expected to be the most difficult iron and aluminum phases to dissolve. These mineral phases have been identified in both SRS and Hanford High Level Waste sludge. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids. The results of the solubility tests indicate that oxalic and sulfuric acids are more effective for the dissolution of the primary sludge phases. For boehmite, elevated temperature will be required to promote effective phase dissolution in the acids studied. Literature reviews, thermodynamic modeling, and experimental results have all confirmed that pH control using a supplemental proton source (additional acid) is critical for minimization of oxalic acid usage during the dissolution of hematite. These results emphasize the importance of pH control in optimizing hematite dissolution in oxalic acid and may explain the somewhat

  10. Alternative Enhanced Chemical Cleaning Basic Studies Results FY09

    International Nuclear Information System (INIS)

    Hay, M.; King, W.

    2010-01-01

    Due to the need to close waste storage tanks, chemical cleaning methods are needed for the effective removal of the heels. Oxalic acid is the preferred cleaning reagent for sludge heel dissolution, particularly for iron-based sludge, due to the strong complexing strength of the oxalate. However, the large quantity of oxalate added to the tank farm from oxalic acid based chemical cleaning has significant downstream impacts. Optimization of the oxalic acid cleaning process can potentially reduce the downstream impacts from chemical cleaning. To optimize oxalic acid usage, a detailed understanding of the chemistry of oxalic acid based sludge dissolution is required. Additionally, other acid systems may be required for specific waste components with low solubility in oxalic acid and as a means to reduce oxalic acid usage in general. Solubility tests were conducted using non-radioactive, pure metal phases known to be the primary phases present in High Level Waste sludge. The metal phases studied included the aluminum phases gibbsite and boehmite and the iron phases magnetite and hematite. Hematite and boehmite are expected to be the most difficult iron and aluminum phases to dissolve. These mineral phases have been identified in both SRS and Hanford High Level Waste sludge. Acids evaluated for dissolution included oxalic, nitric, and sulfuric acids. The results of the solubility tests indicate that oxalic and sulfuric acids are more effective for the dissolution of the primary sludge phases. For boehmite, elevated temperature will be required to promote effective phase dissolution in the acids studied. Literature reviews, thermodynamic modeling, and experimental results have all confirmed that pH control using a supplemental proton source (additional acid) is critical for minimization of oxalic acid usage during the dissolution of hematite. These results emphasize the importance of pH control in optimizing hematite dissolution in oxalic acid and may explain the somewhat

  11. Newly Generated Liquid Waste Processing Alternatives Study, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Landman, William Henry; Bates, Steven Odum; Bonnema, Bruce Edward; Palmer, Stanley Leland; Podgorney, Anna Kristine; Walsh, Stephanie

    2002-09-01

    This report identifies and evaluates three options for treating newly generated liquid waste at the Idaho Nuclear Technology and Engineering Center of the Idaho National Engineering and Environmental Laboratory. The three options are: (a) treat the waste using processing facilities designed for treating sodium-bearing waste, (b) treat the waste using subcontractor-supplied mobile systems, or (c) treat the waste using a special facility designed and constructed for that purpose. In studying these options, engineers concluded that the best approach is to store the newly generated liquid waste until a sodium-bearing waste treatment facility is available and then to co-process the stored inventory of the newly generated waste with the sodium-bearing waste. After the sodium-bearing waste facility completes its mission, two paths are available. The newly generated liquid waste could be treated using the subcontractor-supplied system or the sodium-bearing waste facility or a portion of it. The final decision depends on the design of the sodium-bearing waste treatment facility, which will be completed in coming years.

  12. Feasibility study for an alternative PWR-containment. Stage 3

    International Nuclear Information System (INIS)

    Eibl, J.

    1994-08-01

    The following report deals with a feasibility study on a lightwater reactor containment which is oriented at the German 1300 MW Convoy Type reactor. It was the aim of this containment development for a future nuclear ractor to restrict all consequences of an extreme reactor failure exclusively to the interior of the containment. Also the decay heat of the relevant core catchers is provided to be removed by passive means. This containment development was a common project with the Nuclear Research Centre at Karlsruhe (KFK). As a consequence of this intention the concept started from upper physical limits, such as a maximum static pressure of 1,5 MPa at 200 , a global and local detonation pressure of 8,4 MPa at an impulse of 5,0 kPas, an upward directed force exerted by the pressure vessel of 300 MN, a horizontal force exerted by the moving pressure vessel onto its environment of 70 MN, a cavern pressure around the core catcher of 3,0 resp., 2,0 MPa and a steam explosion-energy of 300 MJ. Such a contaiment concept is presented and inverstigated with respect to its feasibility, statically and dynamically in all relevant details including earthquake actions. (orig.) [de

  13. Study on alternatives of inertisation of nuclear power plant containment

    International Nuclear Information System (INIS)

    Baron, J.H.; Zarate, S.M.

    1998-01-01

    In the course of a severe accident in a nuclear power plant, the hydrogen generation and other flammable gases, during the core degradation phase and the interaction corium-concrete, could produce the failure of the containment by overpressure of by combustion. According to the analysis of the potential effects of hydrogen evolution, following accidents inside the containment trough a Defense-in depth principle, which attempts to assure that the containment must not fail catastrophically, two techniques have been evaluated: a: Inertisation pre-accident and b: Inertisation post-accident. The technique of inertisation pre-accident consists in replacing the air of the containment with inert-gas like nitrogen (N 2 ) or carbon dioxide (CO 2 ) during the normal operation. The inertisation post-accident in combination with early venting system consists in replacing the air of the containment with inert-gas like nitrogen (N 2 ) or carbon dioxide (CO 2 ), immediately after the beginning of the accident, while the radioactivity is still negligible inside the containment. A system of inertisation pre-accident with nitrogen is used on BWR Mark I and Mark II. Investigations on the inertisation post-accident of the containment atmosphere during severe accidents have been carried out with different objectives from principles of the decade of 1980. Studies concerning hydrogen problem for the nuclear power plants Atucha I and CAREM-25 have permitted to know that the hydrogen generation during an accidental sequence with core degradation, would result important, being able to arrive to form explosive mixtures. In the present work, the applicability of the techniques of inertisation is analyzed for the containment of the Atucha I and CAREM-25, considering the particular design characteristics of these plants. (author) [es

  14. Variability of LD50 Values from Rat Oral Acute Toxicity Studies: Implications for Alternative Model Development

    Science.gov (United States)

    Alternative models developed for estimating acute systemic toxicity are generally evaluated using in vivo LD50 values. However, in vivo acute systemic toxicity studies can produce variable results, even when conducted according to accepted test guidelines. This variability can ma...

  15. Endophytic Phytoaugmentation: Treating Wastewater and Runoff Through Augmented Phytoremediation

    Science.gov (United States)

    Redfern, Lauren K.

    2016-01-01

    Abstract Limited options exist for efficiently and effectively treating water runoff from agricultural fields and landfills. Traditional treatments include excavation, transport to landfills, incineration, stabilization, and vitrification. In general, treatment options relying on biological methods such as bioremediation have the ability to be applied in situ and offer a sustainable remedial option with a lower environmental impact and reduced long-term operating expenses. These methods are generally considered ecologically friendly, particularly when compared to traditional physicochemical cleanup options. Phytoremediation, which relies on plants to take up and/or transform the contaminant of interest, is another alternative treatment method which has been developed. However, phytoremediation is not widely used, largely due to its low treatment efficiency. Endophytic phytoaugmentation is a variation on phytoremediation that relies on augmenting the phytoremediating plants with exogenous strains to stimulate associated plant-microbe interactions to facilitate and improve remediation efficiency. In this review, we offer a summary of the current knowledge as well as developments in endophytic phytoaugmentation and present some potential future applications for this technology. There has been a limited number of published endophytic phytoaugmentation case studies and much remains to be done to transition lab-scale results to field applications. Future research needs include large-scale endophytic phytoaugmentation experiments as well as the development of more exhaustive tools for monitoring plant-microbe-pollutant interactions. PMID:27158249

  16. Comparative Theology: An Alternative to Religious Studies or Theology of Religions?

    OpenAIRE

    Betül AVCI

    2018-01-01

    This paper examines the relationship between Comparative Theology, Religious Studies and Theology of Religions and questions whether Comparative Theology is an alternative to the last two. Comparative Theology, a faith seeking understanding practice, may be viewed as an alternative to the Enlightenment ideal of Religious Studies, which seeks “impartiality” and “scientific objectivity” in contrast to Comparative Theology’s enquiry into “truth” and “meaning.” I suggest, however, that the compar...

  17. Impacts of forest management on runoff and erosion

    Science.gov (United States)

    William J. Elliot; Brandon D. Glaza

    2009-01-01

    In a parallel study, ten small watersheds (about 5 ha) were installed in the Priest River Experimental Forest (PREF) in northern Idaho, and another ten were installed in the Boise Basin Experimental Forest (BBEF) in central Idaho. The long-term objective of the study is to compare the effects of different forest management activities on runoff and...

  18. Fluometuron and pendimethalin runoff from strip and conventionally tilled cotton in the southern atlantic coastal plain.

    Science.gov (United States)

    Potter, Thomas L; Truman, Clint C; Bosch, David D; Bednarz, Craig

    2004-01-01

    In the Atlantic Coastal Plain region of southern Georgia (USA), cotton (Gossypium hirsutum L.) acreage increased threefold in the past decade. To more effectively protect water quality in the region, best management practices are needed that reduce pesticide runoff from fields in cotton production. This study compared runoff of two herbicides, fluometuron [N,N-dimethyl-N'-[3-(trifluoromethyl)-phenyl]-urea] and pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitro-benzenamine], from plots in strip-tillage (ST) and conventional-tillage (CT) management near Tifton, GA. Rainfall simulations were conducted one day after preemergence herbicide applications to 0.0006-ha plots and runoff from 0.15-ha plots due to natural rainfall following preemergence pendimethalin and fluometuron and postemergence fluometuron use was monitored. Pendimethalin runoff was greater under CT than ST due to strong pendimethalin soil sorption and higher erosion and runoff under CT. The highest losses, 1.3% of applied in CT and 0.22% of applied in ST, were observed during rainfall simulations conducted 1 DAT. Fluometuron runoff from natural rainfall was substantially lower from ST than from CT plots but the trend was reversed in rainfall simulations. In all studies, fluometuron runoff was also relatively low (<1% of applied), and on plots under natural rainfall, desmethylfluometuron (DMF) represented about 50% of total fluometuron runoff. Fluometuron's relatively low runoff rate appeared linked to its rapid leaching, and high DMF detection rates in runoff support DMF inclusion in fluometuron risk assessments. Results showed that ST has the potential to reduce runoff of both herbicides, but fluometuron leaching may be a ground water quality concern.

  19. Alternative medicine in Paris and Rio de Janeiro: a study on transformative health experiences

    Directory of Open Access Journals (Sweden)

    Elisabeth Eglem

    2014-06-01

    Full Text Available The purpose of this paper is to explore the practice of alternative medicine as an experience capable of modifying the very perception of the body and body feeling, based in a two-field research in France (Paris and Brazil (Rio de Janeiro. In this research, the resort to alternative medicines was considered as urban practice and a possible response to emotional needs, beyond the curative specificities of these medicines. The two countries were chosen for their supposed complementarity concerning the perception of spirituality and therefore, the perception of holistic health concepts. The study relies on an inductive approach and a qualitative methodology: introspective interviews with consumers and professionals, as well as participant observations. After a review of the theoretical aspects on the subject — concepts related to health, alternative medicine, transformative experience —, empirical results are presented. They show that the experience of alternative medicine tends to modify body perception, understood as how individuals define their own body. It also tends to modify body internal feeling, literally how people feel their body. The second conclusion that can be drawn from our study is that, beyond cultural specificities, some similarities appear in the way the practice of alternative medicine impacts on body perception and individual values. In that sense, alternative medicine practices in big urban centers appear to be related to a global consumer culture. However, alternative health behaviors rely on a subjective quest of sense which can be expressed through a variety of practices related to better health, not necessarily involving consumption.

  20. Runoff Potentiality of a Watershed through SCS and Functional Data Analysis Technique

    Science.gov (United States)

    Adham, M. I.; Shirazi, S. M.; Othman, F.; Rahman, S.; Yusop, Z.; Ismail, Z.

    2014-01-01

    Runoff potentiality of a watershed was assessed based on identifying curve number (CN), soil conservation service (SCS), and functional data analysis (FDA) techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling. PMID:25152911

  1. Runoff Potentiality of a Watershed through SCS and Functional Data Analysis Technique

    Directory of Open Access Journals (Sweden)

    M. I. Adham

    2014-01-01

    Full Text Available Runoff potentiality of a watershed was assessed based on identifying curve number (CN, soil conservation service (SCS, and functional data analysis (FDA techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling.

  2. Estrogenic activity, estrogens, and calcium in runoff post-layer litter application from rainfall simulated events

    Science.gov (United States)

    Estrogens in runoff from fields fertilized with animal wastes have been implicated as endocrine disruptors of fish in recipient surface waters. The goal of this study was to measure estrogenic activity in runoff post-application of animal waste with the greatest potential for estrogenic activity - ...

  3. Runoff and Sediment load of the Yan River, China: changes over the last 60 yr

    NARCIS (Netherlands)

    Wang, F.; Mu, X.; Hessel, R.; Zhang, W.; Ritsema, C.J.; Li, R.

    2013-01-01

    Runoff and sediment load changes are affected by climate change and human activities in an integrated way. Historical insight into these effects can not only improve the knowledge of river processes, but also promote more effective land and water management. In this study, we looked at runoff and

  4. Vegetative buffer strips for reducing herbicide transport in runoff: effects of buffer width, vegetation, and season

    Science.gov (United States)

    The effect of vegetative buffer strip (VBS) width, vegetation, and season of the year on herbicide transport in runoff has not been well documented for runoff prone soils. A multi-year replicated plot-scale study was conducted on an eroded claypan soil with the following objectives: 1) assess the ef...

  5. The Impact of Urban Run-Off on Ogbor River | Atuluegwu | Nigerian ...

    African Journals Online (AJOL)

    Impact of urban run-off on Ogbor River in Aba metropolis has been studied. The run-off contains toxic chemical, heavy metals and suspended solids. Water samples were collected from three discharged points in the months of May to September. The results of the analysis of the samples show high-level concentration of ...

  6. The estimation of the catchment runoff using a small number of ...

    African Journals Online (AJOL)

    The estimation of the catchment runoff using a small number of rainfall stations in Burkina Faso. Youssouf Dembele, Jean Duchesne. Abstract. The objective of this study was to determine a suitable method to compute the runoff over a catchment with a few number of rainfall stations. Input hydrological variables were ...

  7. Sorghum-cowpea intercropping : an effective technique against runoff and soil erosion in the Sahel

    NARCIS (Netherlands)

    Zougmore, R.; Kambou, F.N.; Ouattara, K.; Guillobez, S.

    2000-01-01

    In the Central Plateau of Burkina Faso, runoff on bare soil amounts to 40␘f annual rainfall and soil losses reach 4 to 8 Mg ha-? a-?, despite slopes of under 3ÐSeveral studies have shown that mulching the soil surface can reduce runoff by over 60ÐHowever, the scarcity of straw and the

  8. Agroforestry practices, runoff, and nutrient loss: a paired watershed comparison.

    Science.gov (United States)

    Udawatta, Ranjith P; Krstansky, J John; Henderson, Gray S; Garrett, Harold E

    2002-01-01

    A paired watershed study consisting of agroforestry (trees plus grass buffer strips), contour strips (grass buffer strips), and control treatments with a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation was used to examine treatment effects on runoff, sediment, and nutrient losses. During the (1991-1997) calibration and subsequent three-year treatment periods, runoff was measured in 0.91- and 1.37-m H-flumes with bubbler flow meters. Composite samples were analyzed for sediment, total phosphorus (TP), total nitrogen (TN), nitrate, and ammonium. Calibration equations developed to predict runoff, sediment, and nutrients losses explained 66 to 97% of the variability between treatment watersheds. The contour strip and agroforestry treatments reduced runoff by 10 and 1% during the treatment period. In both treatments, most runoff reductions occurred in the second and third years after treatment establishment. The contour strip treatment reduced erosion by 19% in 1999, while erosion in the agroforestry treatment exceeded the predicted loss. Treatments reduced TP loss by 8 and 17% on contour strip and agroforestry watersheds. Treatments did not result in reductions in TN during the first two years of the treatment period. The contour strip and agroforestry treatments reduced TN loss by 21 and 20%, respectively, during a large precipitation event in the third year. During the third year of treatments, nitrate N loss was reduced 24 and 37% by contour strip and agroforestry treatments. Contour strip and agroforestry management practices effectively reduced nonpoint-source pollution in runoff from a corn-soybean rotation in the clay pan soils of northeastern Missouri.

  9. Event-based model diagnosis of rainfall-runoff model structures

    International Nuclear Information System (INIS)

    Stanzel, P.

    2012-01-01

    The objective of this research is a comparative evaluation of different rainfall-runoff model structures. Comparative model diagnostics facilitate the assessment of strengths and weaknesses of each model. The application of multiple models allows an analysis of simulation uncertainties arising from the selection of model structure, as compared with effects of uncertain parameters and precipitation input. Four different model structures, including conceptual and physically based approaches, are compared. In addition to runoff simulations, results for soil moisture and the runoff components of overland flow, interflow and base flow are analysed. Catchment runoff is simulated satisfactorily by all four model structures and shows only minor differences. Systematic deviations from runoff observations provide insight into model structural deficiencies. While physically based model structures capture some single runoff events better, they do not generally outperform conceptual model structures. Contributions to uncertainty in runoff simulations stemming from the choice of model structure show similar dimensions to those arising from parameter selection and the representation of precipitation input. Variations in precipitation mainly affect the general level and peaks of runoff, while different model structures lead to different simulated runoff dynamics. Large differences between the four analysed models are detected for simulations of soil moisture and, even more pronounced, runoff components. Soil moisture changes are more dynamical in the physically based model structures, which is in better agreement with observations. Streamflow contributions of overland flow are considerably lower in these models than in the more conceptual approaches. Observations of runoff components are rarely made and are not available in this study, but are shown to have high potential for an effective selection of appropriate model structures (author) [de

  10. Characteristics of the event mean concentration (EMC) from rainfall runoff on an urban highway

    International Nuclear Information System (INIS)

    Lee, Ju Young; Kim, Hyoungjun; Kim, Youngjin; Han, Moo Young

    2011-01-01

    The purpose of this study was to investigate the characterization of the event mean concentration (EMC) of runoff during heavy precipitation events on highways. Highway runoff quality data were collected from the 7th highway, in South Korea during 2007-2009. The samples were analyzed for runoff quantity and quality parameters such as COD cr , TSS, TPHs, TKN, NO 3 , TP, PO 4 and six heavy metals, e.g., As, Cu, Cd, Ni, Pb and Zn. Analysis of resulting hydrographs and pollutant graphs indicates that the peak of the pollutant concentrations in runoff occurs 20 min after the first rainfall runoff occurrence. The first flush effect depends on the preceding dry period and the rainfall intensity. The results of this study can be used as a reference for water quality management of urban highways. - Research highlights: → Field test on urban highway were performed to 50 of 100 storm events for 3 years. → The peak pollutant concentrations occurs 20 min after the first runoff. → The first flush effect depends on the preceding dry period and rainfall intensity. → Relationship between runoff and event mean concentration for SS and COD. → A crest of the EMC by 70-80 m 3 /event and decreasing EMC after 70-80 m 3 /event. - This study investigate the characterization of the EMC of runoff during rainfall event on highway.

  11. Volumetric runoff coefficients for experimental rural catchments in the Iberian Peninsula

    Science.gov (United States)

    Taguas, Encarnación V.; Molina, Cecilio; Nadal-Romero, Estela; Ayuso, José L.; Casalí, Javier; Cid, Patricio; Dafonte, Jorge; Duarte, Antonio C.; Farguell, Joaquim; Giménez, Rafael; Giráldez, Juan V.; Gómez, Helena; Gómez, Jose A.; González-Hidalgo, J. Carlos; Keizer, J. Jacob; Lucía, Ana; Mateos, Luciano; Rodríguez-Blanco, M. Luz; Schnabel, Sussane; Serrano-Muela, M. Pilar

    2015-04-01

    Analysis of runoff and peaks therein is essential for designing hydraulic infrastructures and for assessing the hydrological implications of likely scenarios of climate and/or land-use change. Different methods are available to calculate runoff coefficients. For instance, the runoff coefficient of a catchment can be described either as the ratio of total depth of runoff to total depth of rainfall or as the ratio of peak flow to rainfall intensity for the time of concentration (Dhakal et al. 2012). If the first definition is considered, runoff coefficients represent the global effect of different features and states of catchments and its determination requires a suitable analysis according to the objectives pursued (Chow et al., 1988). In this work, rainfall-runoff data and physical attributes from small rural catchments located in the Iberian Peninsula (Portugal and Spain) were examined in order to compare the representative values of runoff coefficients using three different approaches: i) statistical analysis of rainfall-runoff data and their quantiles (Dhakal et al., 2012); ii) probabilistic runoff coefficients from the rank-ordered pairs of observed rainfall-runoff data and their relationships with rainfall depths (Schaake et al., 1967); iii) finally, a multiple linear model based on geomorphological attributes. These catchments exhibit great variety with respect to their natural settings, such as climate, topography and lithology. We present a preliminary analysis of the rainfall-runoff relationships as well as their variability in a complex context such as the Iberian Peninsula where contrasted environmental systems coexist. We also discuss reference parameters representing runoff coefficients commonly included into hydrological models. This study is conceived as the first step to explore further working protocols and modeling gaps in a very susceptible area to the climate change such as the Iberian Peninsula's, where the analysis of runoff coefficients is

  12. Assessing the water balance in the Sahel : Impact of small scale rainfall variability on runoff. Part 2 : Idealized modeling of runoff sensitivity

    OpenAIRE

    Vischel, Théo; Lebel, Thierry

    2007-01-01

    As in many other semi-arid regions in the world, the Sahelian hydrological environment is characterized by a mosaic of small endoreic catchments with dry soil surface conditions producing mostly Hortonian runoff. Using an SCS-type event based rainfall-runoff model, an idealized modeling experiment of a Sahelian environment is set up to study the sensitivity of runoff to small scale rainfall variability. A set of 548 observed rain events is used to force the hydrological model to study the sen...

  13. A meta-analysis of pesticide loss in runoff under conventional tillage and no-till management.

    Science.gov (United States)

    Elias, Daniel; Wang, Lixin; Jacinthe, Pierre-Andre

    2018-01-12

    Global agricultural intensification has led to increased pesticide use (37-fold from 1960 to 2005) and soil erosion (14% since 2000). Conservation tillage, including no-till (NT), has been proposed as an alternative to conventional plow till (PT) to mitigate soil erosion, but past studies have reported mixed results on the effect of conservation tillage on pesticide loss. To explore the underlying factors of these differences, a meta-analysis was conducted using published data on pesticide concentration and load in agricultural runoff from NT and PT fields. Peer-reviewed articles (1985-2016) were compiled to build a database for analysis. Contrary to expectations, results showed greater concentration of atrazine, cyanazine, dicamba, and simazine in runoff from NT than PT fields. Further, we observed greater load of dicamba and metribuzin, but reduced load of alachlor from NT fields. Overall, the concentration and the load of pesticides were greater in runoff from NT fields, especially pesticides with high solubility and low affinity for solids. Thus, NT farming affects soil properties that control pesticide retention and interactions with soils, and ultimately their mobility in the environment. Future research is needed for a more complete understanding of pesticide-soil interactions in NT systems. This research could inform the selection of pesticides by farmers and improve the predictive power of pesticide transport models.

  14. A Correlation Study on Attachment Style and GPA of Students at an Alternative Education Center

    OpenAIRE

    Cindy L. Burdick

    2014-01-01

    Adolescents in America are dropping out of school in alarming rates. In the school year 2009- 2010, 514,238 adolescents dropped out of high school. While alternative education centers have been created to meet the needs of these individuals, they are not always successful as evidenced by a graduation rate below 5% in several alternative centers in Florida. Previous studies have shown that students with a positive attachment style have higher grade point averages (GPA) and perform better in sc...

  15. Hillslope runoff and sediment transport in south east Spain

    Science.gov (United States)

    Bracken (Nee Bull), L. J.; Kirkby, M. J.

    2003-04-01

    Runoff from semi-arid hillslopes in SE Spain is generated very selectively at all scales. Site response at the 1 m2 scale may be described by the dynamics of local infiltration and crusting, defining Hydrologically Similar Surfaces (HYSS), which are strongly associated with soil type and vegetation cover. This study reports the use of several reconnaissance methods to define HYSS consistently. These methods are (1) the use of small sediment traps which disturb the surface minimally,(2) the use of painted lines and (3) the identification of Morphological Zones associated with different levels of runoff and sediment transport. Five monitoring sites were established on hillslope concavities in two semi-arid catchments in South East Spain. Rainfall data were also collected from the nearest gauge established during previous research. Results show that a storm event in the Rambla de Nogalte on the 30th of June of 83.0 mm was responsible for a maximum runoff depth of 12 cm and a maximum hillslope sediment transport of 1886 cm3 m-1. The same storm in the Rambla de Torrealvilla produced 53.4 mm of rainfall on the 1st of July 2002, had a maximum runoff depth of 26 cm and was responsible for a maximum hillslope sediment transport of 2311 cm3 m-1. In general sediment transport rate and sediment travel distance increased with the distance downslope into the hillslope hollow, and these were related to the maximum depth of flow produced over the hillside. Very little sediment movement occurred directly downslope of bushes as was expected. No significant relationships were established between sediment transport and slope angle or vegetation cover. However, sediment transport and depth of runoff varied with lithology, with marl sites producing the most runoff and sediment transport. The site located on red schist was particularly unresponsive to rainfall and did not experience much sediment transport. Initial models for the response of larger areas suggest that runoff is controlled

  16. Rain, Snow, and Spring Runoff Revisited.

    Science.gov (United States)

    Bohren, Craig F.

    1995-01-01

    Explores the theory behind the correlation between warm rain, rapid snowmelt, and the subsequent runoff using the concepts of enthalpy, thermal transfer, and energy transfer. Concludes that rapid runoff is not a consequence of rain per se but of the high humidities associated with the rain. (JRH)

  17. The chemical composition of precipitation and runoff water on an arid limestone hillside, northern Negev, Israel

    Science.gov (United States)

    Yair, Aaron; Karnieli, Arnon; Issar, Arie

    1991-12-01

    The study deals with the chemistry of precipitation and runoff water on an arid limestone hillside (467 m 2) the upper part of which is rocky and the lower part soil covered. Rainfall was measured with a rain recorder and sampled with a sequential collector which samples consecutive fractions of 2 mm. Runoff rate was measured with a stage recorder and runoff water was collected immediately after each flow from a collecting tank. Rain and runoff samples were analysed for their major constituents: Na +, K +, Ca 2+, Mg 2+, Cl -, SO 2-4 and HCO -3. Rainfall during the study year (1981/1982) amounted to 75 mm. The salt input by rainfall was 8 g m -2. The salt output by runoff was 1.2 g m -2 for the rocky area and 0.5 g m -2 for the soil-covered area, indicating a substantial net gain for the different areas. Both rainwater and runoff water have a calcium bicarbonate composition. These two ions represent some 55% of the dissolved ions. Runoff water is enriched by a factor of 2 in comparison with rainwater. Finally, the chemistry of runoff water from very small hillslope areas is quite similar to that of flood waters in the major channels of the Negev, pointing to a very limited chemical enrichment with increasing drainage area.

  18. Projected future runoff of the Breede River under climate change ...

    African Journals Online (AJOL)

    The Breede River is the largest river in the Western Cape Province of South Africa, and as such, is a key resource for a variety of activities within the region. It is this significance of the river that prompted a study into the impact of climate change on future runoff in the river and hence, the potential impacts a projected change ...

  19. Using artificial neural network approach for modelling rainfall–runoff ...

    Indian Academy of Sciences (India)

    Department of Civil Engineering, National Pingtung University of Science and Technology, Neipu Hsiang,. Pingtung ... study, a model for estimating runoff by using rainfall data from a river basin is developed and a neural ... For example, 2009 typhoon Morakot in Pingtung ... Tokar and Markus (2000) applied ANN to predict.

  20. An application of artificial intelligence for rainfall–runoff modeling

    Indian Academy of Sciences (India)

    This study proposes an application of two techniques of artificial intelligence (AI) for rainfall–runoff modeling: the artificial neural networks (ANN) and the evolutionary computation (EC). Two diff- erent ANN techniques, the feed forward back propagation (FFBP) and generalized regression neural network (GRNN) methods ...

  1. ISLSCP II UNH/GRDC Composite Monthly Runoff

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: The University of New Hampshire (UNH)/Global Runoff Data Centre (GRDC) composite runoff data combines simulated water balance model runoff estimates...

  2. Measurement and modeling of diclosulam runoff under the influence of simulated severe rainfall.

    Science.gov (United States)

    van Wesenbeeck, I J; Peacock, A L; Havens, P L

    2001-01-01

    A runoff study was conducted near Tifton, GA to measure the losses of water, sediment, and diclosulam (N-(2,6-dichlorophenyl)-5-ethoxy-7-fluoro-[1,2,4]triazolo-[1,5c]-pyrimidine- 2-sulfonamide), a new broadleaf herbicide, under a 50-mm-in-3-h simulated rainfall event on three separate 0.05-ha plots. Results of a runoff study were used to validate the Pesticide Root Zone Model (PRZM, v. 3.12) using field-measured soil, chemical, and weather inputs. The model-predicted edge-of-field diclosulam loading was within 1% of the average observed diclosulam runoff from the field study; however, partitioning between phases was not as well predicted. The model was subsequently used with worst-case agricultural practice inputs and a 41-yr weather record from Dublin, GA to simulate edge-of-field runoff losses for the two most prevalent soils (Tifton and Bibb) in the southeastern U.S. peanut (Arachis hypogaea L.) market for 328 simulation years, and showed that the 90th percentile runoff amounts, expressed as percent of applied diclosulam, were 1.8, 0.6, and 5.2% for the runoff study plots and Tifton and Bibb soils, respectively. The runoff study and modeling indicated that more than 97% of the total diclosulam runoff was transported off the field by water, with < 3% associated with the sediment. Diclosulam losses due to runoff can be further reduced by lower application rates, tillage and crop residue management practices that reduce edge-of-field runoff, and conservation practices such as vegetated filter strips.

  3. Electrochemical degradation of PAH compounds in process water: A kinetic study on model solutions and a proof of concept study on runoff water from harbour sediment purification

    DEFF Research Database (Denmark)

    Muff, Jens; Søgaard, Erik Gydesen

    2010-01-01

    The present study has investigated the possibility to apply electrochemical oxidation in the treatment of polycyclic aromatic hydrocarbon (PAHs) pollutants in water. The reaction kinetics of naphthalene, fluoranthene, and pyrene oxidation have been studied in a batch recirculation experimental...... oxidation side reaction at lower applied voltages. A proof of concept study in real polluted water demonstrated the applicability of the electrochemical oxidation technique for larger scale use, where especially the indirect chloride mediated oxidation approach was a promising technique. However, the risk....... Decreased current densities from 200 to 15 mA cm-2 in the NaCl electrolyte also decreased the removal rates, but significantly enhanced the current efficiencies of the PAH oxidation, based on a defined current efficiency constant, kq. This observation is believed to be due to the suppression of the water...

  4. Variation of Runoff and Precipitation in the Hekou-Longmen Region of the Yellow River Based on Elasticity Analysis

    Directory of Open Access Journals (Sweden)

    Erhui Li

    2014-01-01

    Full Text Available Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution of precipitation to runoff change in the Hekou-Longmen region (from 1957 to 2010, Huangfuchuan watershed (from 1954 to 2010, and Yanhe watershed (from 1952 to 2010 in the middle reaches of the Yellow River. The results showed that runoff appeared a significant decreasing trend (P=0.01 while it was not significant in precipitation in all study areas. In particular, the reductions of average annual runoff in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed were 72.7%, 87.5%, and 32.2%, respectively, during 2000–2010 compared to the 1950s. There existed two abrupt change points of the runoff in the Hekou-Longmen region and Huangfuchuan watershed, which were detected in 1979 and 1998. But in the Yanhe watershed only one abrupt change point was found in 1996. The precipitation elasticities of runoff were 1.11, 1.09, and 1.26, respectively, and the contributions of precipitation on runoff reduction were 26.4%, 17.9%, and 31.6%, respectively, in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed.

  5. Variation of Runoff and Precipitation in the Hekou-Longmen Region of the Yellow River Based on Elasticity Analysis

    Science.gov (United States)

    Li, Erhui; Mu, Xingmin; Zhao, Guangju; Gao, Peng; Shao, Hongbo

    2014-01-01

    Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution of precipitation to runoff change in the Hekou-Longmen region (from 1957 to 2010), Huangfuchuan watershed (from 1954 to 2010), and Yanhe watershed (from 1952 to 2010) in the middle reaches of the Yellow River. The results showed that runoff appeared a significant decreasing trend (P = 0.01) while it was not significant in precipitation in all study areas. In particular, the reductions of average annual runoff in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed were 72.7%, 87.5%, and 32.2%, respectively, during 2000–2010 compared to the 1950s. There existed two abrupt change points of the runoff in the Hekou-Longmen region and Huangfuchuan watershed, which were detected in 1979 and 1998. But in the Yanhe watershed only one abrupt change point was found in 1996. The precipitation elasticities of runoff were 1.11, 1.09, and 1.26, respectively, and the contributions of precipitation on runoff reduction were 26.4%, 17.9%, and 31.6%, respectively, in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed. PMID:24955424

  6. Variation of runoff and precipitation in the Hekou-Longmen region of the Yellow River based on elasticity analysis.

    Science.gov (United States)

    Li, Erhui; Mu, Xingmin; Zhao, Guangju; Gao, Peng; Shao, Hongbo

    2014-01-01

    Precipitation is very important to the formation of runoff, and studying of runoff variation and its response to precipitation has practical significance to sustainable utilization of water resources. The study used Mann-Kendall test, anomaly accumulation method, and precipitation elasticity of runoff method to analyze the changes in the relation of precipitation and runoff and the contribution of precipitation to runoff change in the Hekou-Longmen region (from 1957 to 2010), Huangfuchuan watershed (from 1954 to 2010), and Yanhe watershed (from 1952 to 2010) in the middle reaches of the Yellow River. The results showed that runoff appeared a significant decreasing trend (P = 0.01) while it was not significant in precipitation in all study areas. In particular, the reductions of average annual runoff in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed were 72.7%, 87.5%, and 32.2%, respectively, during 2000-2010 compared to the 1950s. There existed two abrupt change points of the runoff in the Hekou-Longmen region and Huangfuchuan watershed, which were detected in 1979 and 1998. But in the Yanhe watershed only one abrupt change point was found in 1996. The precipitation elasticities of runoff were 1.11, 1.09, and 1.26, respectively, and the contributions of precipitation on runoff reduction were 26.4%, 17.9%, and 31.6%, respectively, in the Hekou-Longmen region, Huangfuchuan watershed, and Yanhe watershed.

  7. Comparative Theology: An Alternative to Religious Studies or Theology of Religions?

    Directory of Open Access Journals (Sweden)

    Betül AVCI

    2018-03-01

    Full Text Available This paper examines the relationship between Comparative Theology, Religious Studies and Theology of Religions and questions whether Comparative Theology is an alternative to the last two. Comparative Theology, a faith seeking understanding practice, may be viewed as an alternative to the Enlightenment ideal of Religious Studies, which seeks “impartiality” and “scientific objectivity” in contrast to Comparative Theology’s enquiry into “truth” and “meaning.” I suggest, however, that the comparative method employed by both Religious Studies and Comparative Theology is not a neutral space. Hence, the new comparativism in Religious Studies reinstates its search for understanding and its political stand, which blurs the boundaries between Comparative Theology and Religious Studies. Likewise, while Comparative Theology is distinct from the Theology of Religions, it does not pose an alternative to it because Comparative Theology, too, often embodies either a pluralist or an inclusivist approach.

  8. A hydrological-modeling study of the impact of land use/land cover and climate change on runoff in a watershed in the western Brazilian Amazonia | Um estudo de modelagem hidrológica do impacto do uso da terra / cobertura da terra e mudanças climáticas ..

    OpenAIRE

    Ranyere Silva Nóbrega

    2016-01-01

    In this work we investigate the effect of land use and land cover in the Jamari sub river basin, located in the Brazilian Amazonian. The objective is twofold: 1) to study the impact of deforestation and climate change on the basin's runoff, and 2) to test the feasibility of using a semi-distributed hydrological model  for studying runoff of a low-slope river basin such as Jamari. We use a wide variety of data such as Landsat imagery, digital elevation data as well as conventional precipitatio...

  9. Transport of oxytetracycline, chlortetracycline, and ivermectin in surface runoff from irrigated pasture.

    Science.gov (United States)

    Bair, Daniel A; Popova, Ina E; Tate, Kenneth W; Parikh, Sanjai J

    2017-09-02

    The transport of oxytetracycline, chlortetracycline, and ivermectin from manure was assessed via surface runoff on irrigated pasture. Surface runoff plots in the Sierra Foothills of Northern California were used to evaluate the effects of irrigation water application rates, pharmaceutical application conditions, vegetative cover, and vegetative filter strip length on the pharmaceutical discharge in surface runoff. Experiments were designed to permit the maximum potential transport of pharmaceuticals to surface runoff water, which included pre-irrigation to saturate soil, trimming grass where manure was applied, and laying a continuous manure strip perpendicular to the flow of water. However, due to high sorption of the pharmaceuticals to manure and soil, less than 0.1% of applied pharmaceuticals were detected in runoff water. Results demonstrated an increase of pharmaceutical transport in surface runoff with increased pharmaceutical concentration in manure, the concentration of pharmaceuticals in runoff water remained constant with increased irrigation flow rate, and no appreciable decrease in pharmaceutical runoff was produced with the vegetative filter strip length increased from 30.5 to 91.5 cm. Most of the applied pharmaceuticals were retained in the manure or within the upper 5 cm of soil directly beneath the manure application sites. As this study evaluated conditions for high transport potential, the data suggest that the risk for significant chlortetracycline, oxytetracycline, and ivermectin transport to surface water from cattle manure on irrigated pasture is low.

  10. Modeling urban storm rainfall runoff from diverse underlying surfaces and application for control design in Beijing.

    Science.gov (United States)

    Ouyang, Wei; Guo, Bobo; Hao, Fanghua; Huang, Haobo; Li, Junqi; Gong, Yongwei

    2012-12-30

    Managing storm rainfall runoff is paramount in semi-arid regions with urban development. In Beijing, pollution prevention in urban storm runoff and storm water utilization has been identified as the primary strategy for urban water management. In this paper, we sampled runoff during storm rainfall events and analyzed the concentration of chemical oxygen demand (COD), total suspended solids (TSS) and total phosphorus (TP) in the runoff. Furthermore, the first flush effect of storm rainfall from diverse underlying surfaces was also analyzed. With the Storm Water Management Model (SWMM), the different impervious rates of underlying surfaces during the storm runoff process were expressed. The removal rates of three typical pollutants and their interactions with precipitation and underlying surfaces were identified. From these rates, the scenarios regarding the urban storm runoff pollution loading from different designs of underlying previous rates were assessed with the SWMM. First flush effect analysis showed that the first 20% of the storm runoff should be discarded, which can help in utilizing the storm water resource. The results of this study suggest that the SWMM can express in detail the storm water pollution patterns from diverse underlying surfaces in Beijing, which significantly affected water quality. The scenario analysis demonstrated that impervious rate adjustment has the potential to reduce runoff peak and decrease pollution loading. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Soil erosion risk as a measure of the effects of land pattern changes on runoff processes in the landscape – case studies from Lower Austria and Central Bohemia

    Science.gov (United States)

    Devátý, Jan; Strauss, Peter; Hoesl, Rosemarie; Dostal, Tomas; Krása, Josef

    2015-04-01

    Changes in land use, landscape structure and agricultural technologies affect number of soil characteristics as well as rainfall-runoff processes in the landscape. Soil erosion and sediment transport can be easily used for documentation and quantification of the impacts of land use development in time. Extent and structure of arable land within a landscape is driven by technological, social and political, factors and differs between countries. However land structure development is more or less natural process and is driven under normal conditions mainly by climatic and economic forces, the effects of political development is very well documented on different sides of the former iron curtain. There is unique chance to compare the trends in historical development during different historical periods given by both of economic and political forces and to search for optimum land structure, using rainfall-runoff processes as a measure. Land structure analysis and soil erosion risk assessment was carried out for two areas of interest and series of historical periods: • Lower Austrian municipality of Kleinweikersdorf (580 ha) - 1822, 1945, 1966, 1990, 2008 • part of Botic river watershed in Central Bohemia (810 ha) - 1841, 1953, 1971, 1989, 2003, 2013 Land use delimitation and field plots spatial definition was digitized from available data sources (Historical Cadastral maps and aerial photographs). Changes in crop properties and management practices were also taken into account based on historical information. Comparison between time periods shows that political actions can cause substantial impact on field plot sizes. At the Austrian area of interest the number of arable field plot continually decreases from 1203 (in 1822) to 371 (in 2008) whereas at the Czech area of interest the initial number of 469 parcels (in 1841) decreases to 32 (in 1989) and then rises again in the last two time periods. While the trend of rising average parcel size in Austria is continuous

  12. Toxicity assessment of simulated urban runoff containing polycyclic musks and cadmium in Carassius auratus using oxidative stress biomarkers

    International Nuclear Information System (INIS)

    Chen Fang; Gao Jie; Zhou Qixing

    2012-01-01

    The objective of this study was to assess potential toxic effects of simulated urban runoff on Carassius auratus using oxidative stress biomarkers. The activity of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and the content of malondialdehyde (MDA) in the liver of C. auratus were analyzed after a 7-, 14- and 21-day exposure to simulated urban runoff containing galaxolide (HHCB) and cadmium (Cd). The results showed that the activity of antioxidant enzymes and the content of MDA increased significantly exposed to the simulated urban runoff containing HHCB alone or mixture of HHCB and Cd. The activity of the investigated enzymes and the content of MDA then returned to the blank level over a longer period of exposure. The oxidative stress could be obviously caused in the liver of C. auratus under the experimental conditions. This could provide useful information for toxic risk assessment of urban runoff. - Highlights: ► We assessed potential toxicity of urban runoff containing HHCB and Cd. ► Exposure of simulated urban runoff can caused oxidative stress in C. auratus liver. ► SOD and CAT are more sensitive than POD and more suitable for indicating the toxicity of urban runoff. ► The present study using oxidative stress biomarkers could provide useful information for toxic risk assessment of urban runoff. - Simulated urban runoff containing HHCB and Cd could cause oxidative stress on the liver of Carassius auratus, which could provide useful information for toxic risk assessment of urban runoff.

  13. Assessing the Impact of Urbanization on Direct Runoff Using Improved Composite CN Method in a Large Urban Area.

    Science.gov (United States)

    Li, Chunlin; Liu, Miao; Hu, Yuanman; Shi, Tuo; Zong, Min; Walter, M Todd

    2018-04-17

    Urbanization is one of the most widespread anthropogenic activities, which brings a range of physical and biochemical changes to hydrological system and processes. Increasing direct runoff caused by land use change has become a major challenge for urban ecological security. Reliable prediction of the quantity and rate of surface runoff is an inherently difficult and time-consuming task for large ungauged urban areas. In this study, we combined Geographic Information System and remote sensing technology with an improved Soil Conservation Service curve number model to evaluate the effects of land use change on direct runoff volume of the four-ring area in Shenyang, China, and analyzed trends of direct runoff at different scales. Through analyzing trends of direct runoff from 1984 to 2015 at different scales, we explored how urbanization and other potential factors affect direct runoff changes. Total direct runoff volume increased over time, and trends varied from the inner urban area to suburban area. Zones 1 and 2 had a tendency toward decreasing direct runoff volume and risks, while Zones 3 and 4 showed gradual increases at both regional and pixel scales. The most important influence on direct runoff change was urban surface change caused by urbanization. This study presents a framework for identifying hotspots of runoff increase, which can provide important guidance to urban managers in future green infrastructure planning, in the hopes of improving the security of urban water ecological patterns.

  14. Assessing the Impact of Urbanization on Direct Runoff Using Improved Composite CN Method in a Large Urban Area

    Science.gov (United States)

    Li, Chunlin; Liu, Miao; Hu, Yuanman; Shi, Tuo; Zong, Min; Walter, M. Todd

    2018-01-01

    Urbanization is one of the most widespread anthropogenic activities, which brings a range of physical and biochemical changes to hydrological system and processes. Increasing direct runoff caused by land use change has become a major challenge for urban ecological security. Reliable prediction of the quantity and rate of surface runoff is an inherently difficult and time-consuming task for large ungauged urban areas. In this study, we combined Geographic Information System and remote sensing technology with an improved Soil Conservation Service curve number model to evaluate the effects of land use change on direct runoff volume of the four-ring area in Shenyang, China, and analyzed trends of direct runoff at different scales. Through analyzing trends of direct runoff from 1984 to 2015 at different scales, we explored how urbanization and other potential factors affect direct runoff changes. Total direct runoff volume increased over time, and trends varied from the inner urban area to suburban area. Zones 1 and 2 had a tendency toward decreasing direct runoff volume and risks, while Zones 3 and 4 showed gradual increases at both regional and pixel scales. The most important influence on direct runoff change was urban surface change caused by urbanization. This study presents a framework for identifying hotspots of runoff increase, which can provide important guidance to urban managers in future green infrastructure planning, in the hopes of improving the security of urban water ecological patterns. PMID:29673182

  15. Conditioned empirical orthogonal functions for interpolation of runoff time series along rivers: Application to reconstruction of missing monthly records

    Science.gov (United States)

    Li, Lingqi; Gottschalk, Lars; Krasovskaia, Irina; Xiong, Lihua

    2018-01-01

    Reconstruction of missing runoff data is of important significance to solve contradictions between the common situation of gaps and the fundamental necessity of complete time series for reliable hydrological research. The conventional empirical orthogonal functions (EOF) approach has been documented to be useful for interpolating hydrological series based upon spatiotemporal decomposition of runoff variation patterns, without additional measurements (e.g., precipitation, land cover). This study develops a new EOF-based approach (abbreviated as CEOF) that conditions EOF expansion on the oscillations at outlet (or any other reference station) of a target basin and creates a set of residual series by removing the dependence on this reference series, in order to redefine the amplitude functions (components). This development allows a transparent hydrological interpretation of the dimensionless components and thereby strengthens their capacities to explain various runoff regimes in a basin. The two approaches are demonstrated on an application of discharge observations from the Ganjiang basin, China. Two alternatives for determining amplitude functions based on centred and standardised series, respectively, are tested. The convergence in the reconstruction of observations at different sites as a function of the number of components and its relation to the characteristics of the site are analysed. Results indicate that the CEOF approach offers an efficient way to restore runoff records with only one to four components; it shows more superiority in nested large basins than at headwater sites and often performs better than the EOF approach when using standardised series, especially in improving infilling accuracy for low flows. Comparisons against other interpolation methods (i.e., nearest neighbour, linear regression, inverse distance weighting) further confirm the advantage of the EOF-based approaches in avoiding spatial and temporal inconsistencies in estimated series.

  16. Impact of Roadway Stormwater Runoff on Microbial Contamination in the Receiving Stream.

    Science.gov (United States)

    Wyckoff, Kristen N; Chen, Si; Steinman, Andrew J; He, Qiang

    2017-09-01

    Stormwater runoff from roadways has increasingly become a regulatory concern for water pollution control. Recent work has suggested roadway stormwater runoff as a potential source of microbial pollutants. The objective of this study was to determine the impact of roadway runoff on the microbiological quality of receiving streams. Microbiological quality of roadway stormwater runoff and the receiving stream was monitored during storm events with both cultivation-dependent fecal bacteria enumeration and cultivation-independent high-throughput sequencing techniques. Enumeration of total coliforms as a measure of fecal microbial pollution found consistently lower total coliform counts in roadway runoff than those in the stream water, suggesting that roadway runoff was not a major contributor of microbial pollutants to the receiving stream. Further characterization of the microbial community in the stormwater samples by 16S ribosomal RNA gene-based high-throughput amplicon sequencing revealed significant differences in the microbial composition of stormwater runoff from the roadways and the receiving stream. The differences in microbial composition between the roadway runoff and stream water demonstrate that roadway runoff did not appear to have a major influence on the stream in terms of microbiological quality. Thus, results from both fecal bacteria enumeration and high-throughput amplicon sequencing techniques were consistent that roadway stormwater runoff was not the primary contributor of microbial loading to the stream. Further studies of additional watersheds with distinct characteristics are needed to validate these findings. Understanding gained in this study could support the development of more effective strategies for stormwater management in sensitive watersheds. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  17. Depuration of highway runoff water into grass-covered embankments.

    Science.gov (United States)

    Boivin, P; Saadé, M; Pfeiffer, H R; Hammecker, C; Degoumois, Y

    2008-06-01

    The management of polluted road runoff water is an important issue in environmental protection. A strategy could be to perform local depuration by infiltration into the soils of the embankment, but knowledge for designing such systems is lacking. This study aims at discussing the relevant soil properties, by estimating the long-term depuration of road runoff water infiltrating into the sandy soil embankment of the A9 highway in Wallis, Switzerland. This was done by estimating the heavy metals (HM) mass balance of two sites 23 and 12 years old, respectively. The accumulated HM were estimated by soil and GB analyses. The HM input was estimated by average water quality and traffic. The results were discussed using two-dimensional simulation of infiltration and a 14 months in situ monitoring of the runoff from the pavement to the embankment and at the bottom of the embankment. The soil properties were appropriate for both small particle adsorption and filtration. A good match between input and stored pollutant charges was found, and the HM profiles accorded well with infiltration simulation and monitoring results, which showed that 80-100% of the runoff water infiltrated into the embankment. Replacement of the cracked concrete gutters by an infiltration channel made of similar soil is recommended. These results oppose the Swiss guidelines for road-polluted water infiltration, as much more clayey soils are recommended. These later soils are difficult to find in Switzerland, and may allow for preferential flow through macro pores, in contrast to the studied site.

  18. Microbial and chemical markers: runoff transfer in animal manure-amended soils.

    Science.gov (United States)

    Jaffrezic, Anne; Jardé, Emilie; Pourcher, Anne-Marie; Gourmelon, Michèle; Caprais, Marie-Paule; Heddadj, Djilali; Cottinet, Patrice; Bilal, Muhamad; Derrien, Morgane; Marti, Romain; Mieszkin, Sophie

    2011-01-01

    Fecal contamination of water resources is evaluated by the enumeration of the fecal coliforms and Enterococci. However, the enumeration of these indicators does not allow us to differentiate between the sources of fecal contamination. Therefore, it is important to use alternative indicators of fecal contamination to identify livestock contamination in surface waters. The concentration of fecal indicators (, enteroccoci, and F-specific bacteriophages), microbiological markers (Rum-2-bac, Pig-2-bac, and ), and chemical fingerprints (sterols and stanols and other chemical compounds analyzed by 3D-fluorescence excitation-matrix spectroscopy) were determined in runoff waters generated by an artificial rainfall simulator. Three replicate plot experiments were conducted with swine slurry and cattle manure at agronomic nitrogen application rates. Low amounts of bacterial indicators (1.9-4.7%) are released in runoff water from swine-slurry-amended soils, whereas greater amounts (1.1-28.3%) of these indicators are released in runoff water from cattle-manure-amended soils. Microbial and chemical markers from animal manure were transferred to runoff water, allowing discrimination between swine and cattle fecal contamination in the environment via runoff after manure spreading. Host-specific bacterial and chemical markers were quantified for the first time in runoff waters samples after the experimental spreading of swine slurry or cattle manure. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

  19. Stormwater runoff drives viral community composition changes in inland freshwaters

    Science.gov (United States)

    Williamson, Kurt E.; Harris, Jamie V.; Green, Jasmin C.; Rahman, Faraz; Chambers, Randolph M.

    2014-01-01

    Storm events impact freshwater microbial communities by transporting terrestrial viruses and other microbes to freshwater systems, and by potentially resuspending microbes from bottom sediments. The magnitude of these impacts on freshwater ecosystems is unknown and largely unexplored. Field studies carried out at two discrete sites in coastal Virginia (USA) were used to characterize the viral load carried by runoff and to test the hypothesis that terrestrial viruses introduced through stormwater runoff change the composition of freshwater microbial communities. Field data gathered from an agricultural watershed indicated that primary runoff can contain viral densities approximating those of receiving waters. Furthermore, viruses attached to suspended colloids made up a large fraction of the total load, particularly in early stages of the storm. At a second field site (stormwater retention pond), RAPD-PCR profiling showed that the viral community of the pond changed dramatically over the course of two intense storms while relatively little change was observed over similar time scales in the absence of disturbance. Comparisons of planktonic and particle-associated viral communities revealed two completely distinct communities, suggesting that particle-associated viruses represent a potentially large and overlooked portion of aquatic viral abundance and diversity. Our findings show that stormwater runoff can quickly change the composition of freshwater microbial communities. Based on these findings, increased storms in the coastal mid-Atlantic region predicted by most climate change models will likely have important impacts on the structure and function of local freshwater microbial communities. PMID:24672520

  20. [Runoff Pollution Experiments of Paddy Fields Under Different Irrigation Patterns].

    Science.gov (United States)

    Zhou, Jing-wen; Su, Bao-lin; Huang, Ning-bo; Guan, Yu-tang; Zhao, Kun

    2016-03-15

    To study runoff and non-point source pollution of paddy fields and to provide a scientific basis for agricultural water management of paddy fields, paddy plots in the Jintan City and the Liyang City were chosen for experiments on non-point source pollution, and flood irrigation and intermittent irrigation patterns were adopted in this research. The surface water level and rainfall were observed during the growing season of paddies, and the runoff amount from paddy plots and loads of total nitrogen (TN) and total phosphorus (TP) were calculated by different methods. The results showed that only five rain events of totally 27 rainfalls and one artificially drainage formed non-point source pollution from flood irrigated paddy plot, which resulted in a TN export coefficient of 49.4 kg · hm⁻² and a TP export coefficient of 1.0 kg · hm⁻². No any runoff event occurred from the paddy plot with intermittent irrigation even in the case of maximum rainfall of 95.1 mm. Runoff from paddy fields was affected by water demands of paddies and irrigation or drainage management, which was directly correlated to surface water level, rainfall amount and the lowest ridge height of outlets. Compared with the flood irrigation, intermittent irrigation could significantly reduce non-point source pollution caused by rainfall or artificial drainage.

  1. A Study on Becoming an Alternatively Certified Career and Technical Educator

    Science.gov (United States)

    Cotton-Flanagan, Kymberli A.

    2011-01-01

    This mixed method study examined the perspectives of twelve practicing high school CTE teachers engaged in a newly approved university model for alternative certification. Using Creswell's (2008) Sequential Exploratory Design and the lens of adult learning theory as established in Knowles' (1970) Theory of Andragogy, this study examines how…

  2. Using an Empirical Binomial Hierarchical Bayesian Model as an Alternative to Analyzing Data from Multisite Studies

    Science.gov (United States)

    Hardin, J. Michael; Anderson, Billie S.; Woodby, Lesa L.; Crawford, Myra A.; Russell, Toya V.

    2008-01-01

    This article explores the statistical methodologies used in demonstration and effectiveness studies when the treatments are applied across multiple settings. The importance of evaluating and how to evaluate these types of studies are discussed. As an alternative to standard methodology, the authors of this article offer an empirical binomial…

  3. Why We Teach: Autobiographies of Traditionally and Alternatively Certified Pre-Service Social Studies Teachers

    Science.gov (United States)

    Santoli, Susan

    2009-01-01

    This study describes the analysis of the social studies autobiographies of 46 students compiled over a 15 month period. Two major questions were addressed: (1) what motivational patterns are revealed in these autobiographies and (2) what differences and similarities exist in the autobiographies of students seeking alternative and traditional…

  4. Perennial grass management impacts on runoff and sediment export from vegetated channels in pulse flow runoff events

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, H.M. [Department of Agriculture and Natural Resources, University of Minnesota-Crookston, 2900 University Avenue, Crookston, MN 56716 (United States); Cruse, R.M.; Burras, C.L. [Agronomy Department, Iowa State University, Ames, IA 50010-1010 (United States)

    2011-01-15

    The goal of the United States Congress is to replace 30% of United States petroleum with biofuels by 2030. If this goal will be accomplished, it is estimated that 25-50% of the land enrolled in the Conservation Reserve Program (CRP) have its biomass removed. However, the purpose of many conservation practices enrolled in CRP is to improve or maintain water quality and not to serve as a source of biomass. This study was conducted to determine if biomass removal has an effect on runoff and sediment export from vegetated channels during low intensity storms that occur frequently. In June 2006, 24 channels were created that measured 2 m x 10 m. The treatments of grass species (big bluestem, corn, smooth bromegrass, and switchgrass) and biomass removal (removed, not removed) were applied to the channels in a split-plot arrangement. Three times in 2007 and 3 more times in 2008, a 787 L load of water with suspended sediment was drained on the head and sides of each experimental unit and the entire load of water that ran off was collected, weighed, and sampled for sediment concentration. Biomass removal increased runoff and sediment by an average of 15% over the two years of the study. The channels planted to perennial C4 grasses were most effective at reducing runoff and sediment export, while the corn was consistently the least effective at reducing runoff and sediment export. (author)

  5. Perennial grass management impacts on runoff and sediment export from vegetated channels in pulse flow runoff events

    International Nuclear Information System (INIS)

    Wilson, H.M.; Cruse, R.M.; Burras, C.L.

    2011-01-01

    The goal of the United States Congress is to replace 30% of United States petroleum with biofuels by 2030. If this goal will be accomplished, it is estimated that 25-50% of the land enrolled in the Conservation Reserve Program (CRP) have its biomass removed. However, the purpose of many conservation practices enrolled in CRP is to improve or maintain water quality and not to serve as a source of biomass. This study was conducted to determine if biomass removal has an effect on runoff and sediment export from vegetated channels during low intensity storms that occur frequently. In June 2006, 24 channels were created that measured 2 m x 10 m. The treatments of grass species (big bluestem, corn, smooth bromegrass, and switchgrass) and biomass removal (removed, not removed) were applied to the channels in a split-plot arrangement. Three times in 2007 and 3 more times in 2008, a 787 L load of water with suspended sediment was drained on the head and sides of each experimental unit and the entire load of water that ran off was collected, weighed, and sampled for sediment concentration. Biomass removal increased runoff and sediment by an average of 15% over the two years of the study. The channels planted to perennial C4 grasses were most effective at reducing runoff and sediment export, while the corn was consistently the least effective at reducing runoff and sediment export. (author)

  6. Comparative theology: an alternative to religious studies or theology of religions?

    OpenAIRE

    Avcı, Betül

    2018-01-01

    Avcı, Betül (IHU Author) This paper examines the relationship between Comparative Theology, Religious Studies and Theology of Religions and questions whether Comparative Theology is an alternative to the last two. Comparative Theology, a faith seeking understanding practice, may be viewed as an alternative to the Enlightenment ideal of Religious Studies, which seeks “impartiality” and “scientific objectivity” in contrast to Comparative Theology’s enquiry into “truth” and “meaning.” I sugge...

  7. Erosivity, surface runoff, and soil erosion estimation using GIS-coupled runoff-erosion model in the Mamuaba catchment, Brazil.

    Science.gov (United States)

    Marques da Silva, Richarde; Guimarães Santos, Celso Augusto; Carneiro de Lima Silva, Valeriano; Pereira e Silva, Leonardo

    2013-11-01

    This study evaluates erosivity, surface runoff generation, and soil erosion rates for Mamuaba catchment, sub-catchment of Gramame River basin (Brazil) by using the ArcView Soil and Water Assessment Tool (AvSWAT) model. Calibration and validation of the model was performed on monthly basis, and it could simulate surface runoff and soil erosion to a good level of accuracy. Daily rainfall data between 1969 and 1989 from six rain gauges were used, and the monthly rainfall erosivity of each station was computed for all the studied years. In order to evaluate the calibration and validation of the model, monthly runoff data between January 1978 and April 1982 from one runoff gauge were used as well. The estimated soil loss rates were also realistic when compared to what can be observed in the field and to results from previous studies around of catchment. The long-term average soil loss was estimated at 9.4 t ha(-1) year(-1); most of the area of the catchment (60%) was predicted to suffer from a low- to moderate-erosion risk (soil erosion was estimated to exceed > 12 t ha(-1) year(-1). Expectedly, estimated soil loss was significantly correlated with measured rainfall and simulated surface runoff. Based on the estimated soil loss rates, the catchment was divided into four priority categories (low, moderate, high and very high) for conservation intervention. The study demonstrates that the AvSWAT model provides a useful tool for soil erosion assessment from catchments and facilitates the planning for a sustainable land management in northeastern Brazil.

  8. Experimental Study of Heat Transfer Enhancements from Array of Alternate Rectangular Dwarf Fins at Different Inclinations

    Science.gov (United States)

    Awasarmol, Umesh Vandeorao; Pise, Ashok T.

    2018-02-01

    The main objective of this experimental work is to investigate and compare heat transfer enhancement of alternate dwarf fin array at different angles of inclination. In this study, the steady state heat transfer from the full length fin arrays and alternate dwarf fin arrays are measured in natural convection and radiation environment. Largest increase in the Nusselt number was achieved with alternate dwarf fin at angle of orientation 90°, which shows about 28% enhanced heat transfer coefficient as opposed to the full-length fin array with 25% saving in material. In case of non-black FAB, contribution of radiation heat transfer is found to be very small nearly within 1% of the heater input. After coating lamp black contribution of radiation heat transfer is found to increase to about 3-4% of the heater input in the range of temperatures considered in this study.

  9. An Interpretive Study of Yosemite National Park Visitors' Perspectives Toward Alternative Transportation in Yosemite Valley

    Science.gov (United States)

    White, Dave D.

    2007-01-01

    The National Park Service (NPS) is increasingly focusing on alternative transportation systems in national parks to address environmental and social problems arising from a historical reliance on personal automobiles as the primary means of visitor access. Despite the potential advantages, alternative transportation may require a reorientation in the way that Americans have experienced national parks since the advent of auto-tourism in the early twentieth century. Little research exists, however, on visitor perspectives towards alternative transportation or the rationale underlying their perspectives. It remains unclear how transportation systems affect visitors’ experiences of the park landscape or the factors influencing their travel behavior in the parks. This report presents an interpretive study of visitor perspectives toward transportation management in the Yosemite Valley area of Yosemite National Park, California. Qualitative analysis of 160 semi-structured interviews identified individual psychological factors as well as situational influences that affect visitors’ behavior and perspectives. Individual psychological factors include perceived freedom, environmental values and beliefs, prior experience with Yosemite National Park and other national parks, prior experience with alternative transportation in national parks, and sensitivity to subjective perceptions of crowding. Situational factors included convenience, access, and flexibility of travel modes, as well as type of visit, type of group, and park use level. Interpretive communication designed to encourage voluntary visitor use of alternative transportation should focus on these psychological and situational factors. Although challenges remain, the results of this study suggest approaches for shaping the way Americans visit and experience their national parks to encourage environmental sustainability.

  10. In-situ biochar application conserves nutrients while simultaneously mitigating runoff and erosion of an Fe-oxide-enriched tropical soil.

    Science.gov (United States)

    Lee, Chia-Hsing; Wang, Chung-Chi; Lin, Huan-Hsuan; Lee, Sang Soo; Tsang, Daniel C W; Jien, Shih-Hao; Ok, Yong Sik

    2018-04-01

    Climate change gives rise to rapid degradation of rural soils in sloping subtropical and tropical areas and might further threaten environmental sustainability. In this study, we conducted an integrated evaluation of the effects of wood biochar (WB) application mixed with a green waste dreg compost (GWC) on runoff quality, soil losses, and agricultural productivity for a highly weathered tropical soil. A conventional agriculture method, in which soils are treated with anionic polyacrylamide (PAM), was also conducted for comparison. The amounts of runoff and soil loss, and nutrient retention were evaluated a year after WB application. Soil fertility was also investigated through a year pot experiment with rape (Brassica campestris L.) cultivation. Our results showed that the WB application not only effectively increased soil pH, soil organic carbon (SOC) and exchangeable K + but also increased the production of rape plants. Significant reduction of runoff and the increases of inorganic nitrogen (IN) and total phosphorus (TP) were found in the WB-treated soil. Compared to the control, the co-application of WB and GWC, particularly for the WB at 4%, decreased runoff by 16.8%, soil loss by 25%, and IN loss (via runoff) by 41.8%. Meanwhile, compared to the control and PAM treatments, the co-application of WB and GWC improved soil acidity and the contents of SOC, IN, TP, and exchangeable K + . The co-application of WB and GWC could be an alternative agricultural strategy to obtain benefits to agricultural productivity and environmental sustainability. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Impacts of climate variability on the runoff in the South Eastern part of Bulgaria

    International Nuclear Information System (INIS)

    Lizama Rivas, Bernardo; Koleva-Lizama, Ivanka

    2004-01-01

    The basic climatic factors, which affect the river runoff, are atmospheric precipitation and temperature. On the basis of the set of data from some hydro-meteorological gauging stations with more than 45 years observations have been studied the effect of meteorological conditions on runoff in the southeastern region of Bulgaria. The change of the temperature, precipitation and runoff over the southeastern Bulgarian catchments are investigated and analyzed. During the application of several statistical tests was found that there are changes in the runoff, which are not caused by the man's activity. The features in the variations of above mentioned hydro-meteorological elements and their inherent trends are determined. The results of this study show that the runoff decreases considerably all over the studied region in the last years. An attempt to find a cause of the changes was done. The significant tendency to gradual reduction of runoff in the region is due to considerably decrease of the precipitation all over the Balkans. The study shows that high temperatures and low precipitation conduct to drought in the region and appears unsuitable conditions for the river runoff feeding and development of plants. (Author)

  12. Impacts of the active layer on runoff in an upland permafrost basin, northern Tibetan Plateau.

    Science.gov (United States)

    Gao, Tanguang; Zhang, Tingjun; Guo, Hong; Hu, Yuantao; Shang, Jianguo; Zhang, Yulan

    2018-01-01

    The paucity of studies on permafrost runoff generation processes, especially in mountain permafrost, constrains the understanding of permafrost hydrology and prediction of hydrological responses to permafrost degradation. This study investigated runoff generation processes, in addition to the contribution of summer thaw depth, soil temperature, soil moisture, and precipitation to streamflow in a small upland permafrost basin in the northern Tibetan Plateau. Results indicated that the thawing period and the duration of the zero-curtain were longer in permafrost of the northern Tibetan Plateau than in the Arctic. Limited snowmelt delayed the initiation of surface runoff in the peat permafrost in the study area. The runoff displayed intermittent generation, with the duration of most runoff events lasting less than 24 h. Precipitation without runoff generation was generally correlated with lower soil moisture conditions. Combined analysis suggested runoff generation in this region was controlled by soil temperature, thaw depth, precipitation frequency and amount, and antecedent soil moisture. This study serves as an important baseline to evaluate future environmental changes on the Tibetan Plateau.

  13. Impervious surfaces and sewer pipe effects on stormwater runoff temperature

    Science.gov (United States)

    Sabouri, F.; Gharabaghi, B.; Mahboubi, A. A.; McBean, E. A.

    2013-10-01

    The warming effect of the impervious surfaces in urban catchment areas and the cooling effect of underground storm sewer pipes on stormwater runoff temperature are assessed. Four urban residential catchment areas in the Cities of Guelph and Kitchener, Ontario, Canada were evaluated using a combination of runoff monitoring and modelling. The stormwater level and water temperature were monitored at 10 min interval at the inlet of the stormwater management ponds for three summers 2009, 2010 and 2011. The warming effect of the ponds is also studied, however discussed in detail in a separate paper. An artificial neural network (ANN) model for stormwater temperature was trained and validated using monitoring data. Stormwater runoff temperature was most sensitive to event mean temperature of the rainfall (EMTR) with a normalized sensitivity coefficient (Sn) of 1.257. Subsequent levels of sensitivity corresponded to the longest sewer pipe length (LPL), maximum rainfall intensity (MI), percent impervious cover (IMP), rainfall depth (R), initial asphalt temperature (AspT), pipe network density (PND), and rainfall duration (D), respectively. Percent impervious cover of the catchment area (IMP) was the key parameter that represented the warming effect of the paved surfaces; sensitivity analysis showed IMP increase from 20% to 50% resulted in runoff temperature increase by 3 °C. The longest storm sewer pipe length (LPL) and the storm sewer pipe network density (PND) are the two key parameters that control the cooling effect of the underground sewer system; sensitivity analysis showed LPL increase from 345 to 966 m, resulted in runoff temperature drop by 2.5 °C.

  14. Attribution analysis of runoff decline in a semiarid region of the Loess Plateau, China

    Science.gov (United States)

    Li, Binquan; Liang, Zhongmin; Zhang, Jianyun; Wang, Guoqing; Zhao, Weimin; Zhang, Hongyue; Wang, Jun; Hu, Yiming

    2018-01-01

    Climate variability and human activities are two main contributing attributions for runoff changes in the Yellow River, China. In the loess hilly-gully regions of the middle Yellow River, water shortage has been a serious problem, and this results in large-scale constructions of soil and water conservation (SWC) measures in the past decades in order to retain water for agricultural irrigation and industrial production. This disturbed the natural runoff characteristics. In this paper, we focused on a typical loess hilly-gully region (Wudinghe and Luhe River basins) and investigated the effects of SWC measures and climate variability on runoff during the period of 1961-2013, while the SWC measures were the main representative of human activities in this region. The nonparametric Mann-Kendall test was used to analyze the changes of annual precipitation, air temperature, potential evapotranspiration (PET), and runoff. The analysis revealed the decrease in precipitation, significant rise in temperature, and remarkable runoff reduction with a rate of more than 0.4 mm per year. It was found that runoff capacity in this region also decreased. Using the change point detection methods, the abrupt change point of annual runoff series was found at 1970, and thus, the study period was divided into the baseline period (1961-1970) and changed period (1971-2013). A conceptual framework based on four statistical runoff methods was used for attribution analysis of runoff decline in the Wudinghe and Luhe River basins (-37.3 and -56.4%, respectively). Results showed that runoff reduction can be explained by 85.2-90.3% (83.3-85.7%) with the SWC measures in the Wudinghe (Luhe) River basin while the remaining proportions were caused by climate variability. The findings suggested that the large-scale SWC measures demonstrated a dominant influence on runoff decline, and the change of precipitation extreme was also a promoting factor of the upward trending of SWC measures' contribution to

  15. Green Roofs for Stormwater Runoff Control - Abstract

    Science.gov (United States)

    This project evaluated green roofs as a stormwater management tool. Specifically, runoff quantity and quality from green and flat asphalt roofs were compared. Evapotranspiration from planted green roofs and evaporation from unplanted media roofs were also compared. The influence...

  16. Analysis and Modeling of Time-Correlated Characteristics of Rainfall-Runoff Similarity in the Upstream Red River Basin

    Directory of Open Access Journals (Sweden)

    Xiuli Sang

    2012-01-01

    Full Text Available We constructed a similarity model (based on Euclidean distance between rainfall and runoff to study time-correlated characteristics of rainfall-runoff similar patterns in the upstream Red River Basin and presented a detailed evaluation of the time correlation of rainfall-runoff similarity. The rainfall-runoff similarity was used to determine the optimum similarity. The results showed that a time-correlated model was found to be capable of predicting the rainfall-runoff similarity in the upstream Red River Basin in a satisfactory way. Both noised and denoised time series by thresholding the wavelet coefficients were applied to verify the accuracy of model. And the corresponding optimum similar sets obtained as the equation solution conditions showed an interesting and stable trend. On the whole, the annual mean similarity presented a gradually rising trend, for quantitatively estimating comprehensive influence of climate change and of human activities on rainfall-runoff similarity.

  17. A Study of the Effect of Alternative Programs on the Potential Dropout.

    Science.gov (United States)

    Gloria, Cyril; Karr-Kidwell, PJ

    Educators are very concerned about the problem of students dropping out of school. The reasons for students dropping out vary from social to economic causes. Alternative programs or schools have been used since the 1960s to try to keep students in school. This study involved a literature review of research on the identification and remediation of…

  18. Fourth "R" in Analytic Mode: A Study of Alternatives to Religious Instruction in the Public Schools.

    Science.gov (United States)

    Dudley, Noel W.

    This doctoral dissertation examines alternatives for public-school religious education which stress spiritual values but do not conflict with legal restrictions. The study is divided into four parts. Part one is an historical survey of religious education in public schools that includes an interpretation of the legal restrictions and the…

  19. FOCUSED FEASIBILITY STUDY OF PHYTOREMEDIATION ALTERNATIVE FOR THE INDUSTRIAL EXCESS LANDFILL SITE IN STARK COUNTY, OHIO.

    Science.gov (United States)

    Focused feasibility study of phytoremediation alternative for the Industrial Excess Landfill site in Stark County, Ohio. More information can be found on the NPL Fact Sheet for this site at www.epa.gov/region5/superfund/npl/ohio/OHD000377971.htm

  20. Coupling Cover Crops with Alternative Swine Manure Application Strategies: Manure-15N Tracer Studies

    Science.gov (United States)

    Integration of rye cover crops with alternative liquid swine (Sus scrofa L.) manure application strategies may enhance retention of manure N in corn (Zea mays L.) - soybean [Glycine max (L.) Merr] cropping systems. The objective of this study was to quantify uptake of manure derived-N by a rye (Seca...

  1. Alternative Conceptions in Animal Classification Focusing on Amphibians and Reptiles: A Cross-Age Study

    Science.gov (United States)

    Yen, Chiung-Fen; Yao, Tsung-Wei; Chiu, Yu-Chih

    2004-01-01

    This study examined students' alternative conceptions of reptiles and amphibians and the extent to which these conceptions remain intact through the elementary (grades 4 and 6), junior, and senior high school years. We administered multiple-choice and free-response instruments to a total of 513 students and interviewed at least 20 students at each…

  2. Final cost reduction study for the Geysers Recharge Alternative. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The purpose of this study is to determine whether or not cost reduction opportunities exist for the Geysers Recharge Alternative as defined in the Santa Rosa Subregional Long-Term Wastewater Project EIR/EIS. The City of Santa Rosa has been directed to have a plan for reclaimed water disposal in place by 1999 which will meet future capacity needs under all weather conditions. A Draft EIR/EIS released in July 1996 and a Final EIR certified in June 1997 examine four primary alternatives plus the No Action Alternative. Two of the primary alternatives involve agricultural irrigation with reclaimed water, either in western or southern Sonoma County. Another involves increased discharge of reclaimed water into the Russian River. The fourth involves using reclaimed water to replenish the geothermal reservoir at the Geysers. The addition of this water source would enable the Geysers operators to produce more steam from the geothermal area and thereby prolong the life and economic production level of the steamfield and the geothermal power plants supplied by the steamfield. This study provides additional refined cost estimates for new scenarios which utilize an alternative pipeline alignment and a range of reclaimed water flows, which deliver less water to the Geysers than proposed in the EIR/EIS (by distributing flow to other project components). Also, electrical power rates were revised to reflect the recent changes in costs associated with deregulation of the power industry. In addition, this report provides information on sources of potential public and private funding available and future environmental documentation required if the cost reduction scenarios were to be selected by the City as part of their preferred alternative.

  3. Urban Runoff: Getting to the Nonpoint

    OpenAIRE

    Pendall, Rolf

    1994-01-01

    Mandates for water-quality improvement have forced regulators and planners to confront the problem of urban runoff, still an important source of water pollution. This ar­ticle discusses those mandates and how to meet them, and provides examples of ongoing nonpoint water pollution control programs in the San Francisco Bay Area. These examples suggest that cleanup of urban runoff may require more comprehensive regional planning to encourage a de­velopment pattern conducive to pollution control.

  4. ARIES CATCHMENT UPPER AND MIDDLE COURSE SMALL STREAMS SEASONAL RUNOFF REGIME CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    CS. HORVATH

    2013-03-01

    Full Text Available The study is based on the processing and interpreting data from 16 gauging stations, of which 10 control catchments smaller than 150 km2 and so reflects more faithfully the local characteristics of the runoff. To highlight the runoff regime features during the year we selected three periods (1950-1967, 1950-2009 and 1970-2009. The geographical features of the central eastern part of the Apuseni Mountains, especially the climatic and geomorphic characteristics, are faithfully reflected in the rivers runoff regime. So, on all rivers the dominant is the spring runoff and the lowest percentage of the total annual average water volume is measured in the winter. Distribution and frequency of the richest (March, April and May and the poorest (January, February, August and September average runoff months vary according to the catchments altitude. The multiannual seasonal and monthly variation of the runoff was highlighted by the coefficients of variation. The study reveals that the rhythmic structure of the runoff regime reflects the local supply, the geological conditions and the reliefs morphological and morphometric characteristics.

  5. Possible change on the runoff in the upper Yellow River basin under global climate change

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this study,the characteristics and changing trends of temperature,precipitation,and runoff in the upper Yellow River basin up Tangnag station are analyzed by using hydrological and meteorological data in the past 50 years from observation stations in the basin.Further,in this study,the evolving trend of runoff in the future decades is forecasted in the basin based on the method of suppositional climate scenes combination.The results indicate temperature variation in the basin has an evident positive relation with global warming,and the precipitation variations are quite complicated in the basin because of differences of located geographic positions during the past 50 years.Runoff in the basin has been decreasing continually since the end of the 1980s because the mean temperature in the basin has been rising and precipitation in the main areas of runoff formation in the basin has been decreasing.Runoff will largely decrease if precipitation decreases and temperature rises continuously,whereas runoff will increase if temperature is invariable and precipitation increases largely;the increase magnitude of runoff may be more than that of precipitation because of the synchronously increasing supply of meltwater from snow,glacier,and frozen soils in future several decades.

  6. Alternative Education: A Comparative Case Study of the Behavior Modification Programs of Two Upstate South Carolina Alternative Schools for Youth Who Exhibit Behavior That Is Disruptive

    Science.gov (United States)

    Scipio, Timothy Lamont

    2013-01-01

    This study examined behavior modification programs in schools designed to focus on discipline and that aim to reform disruptive behavior in students, usually over a limited period of time. This was a comparative case study of two type II alternative schools in the Upstate of South Carolina. The findings contributed to the research base regarding…

  7. The effect of poultry manure application rate and AlCl(3) treatment on bacterial fecal indicators in runoff.

    Science.gov (United States)

    Brooks, J P; Adeli, A; McLaughlin, M R; Miles, D M

    2012-12-01

    Increasing costs associated with inorganic fertilizer have led to widespread use of broiler litter. Proper land application, typically limiting nutrient loss, is essential to protect surface water. This study was designed to evaluate litter-borne microbial runoff (heterotrophic plate count bacteria, staphylococci, Escherichia coli, enterococci, and Clostridium perfringens) while applying typical nutrient-control methods. Field studies were conducted in which plots with high and low litter rates, inorganic fertilizer, AlCl(3)-treated litter, and controls were rained on five times using a rain generator. Overall, microbial runoff from poultry litter applied plots was consistently greater (2-5 log(10) plot(-1)) than controls. No appreciable effect on microbial runoff was noted from variable litter application rate or AlCl(3) treatments, though rain event, not time, significantly affected runoff load. C. perfringens and staphylococci runoff were consistently associated with poultry litter application, during early rain events, while other indicators were unreliable. Large microbial runoff pulses were observed, ranging from 10(2) to 10(10) CFU plot(-1); however, only a small fraction of litter-borne microbes were recoverable in runoff. This study indicated that microbial runoff from litter-applied plots can be substantial, and that methods intended to reduce nutrient losses do not necessarily reduce microbial runoff.

  8. Contrast Runoff Correlates with the Clinical Outcome of Cervical Epidural Neuroplasty Using a Racz Catheter.

    Science.gov (United States)

    Han, Yun-Joung; Lee, Myoung No; Cho, Min Ji; Park, Hue Jung; Moon, Dong Eon; Kim, Young Hoon

    2016-01-01

    Epidural neuroplasty using a Racz catheter has a therapeutic effect. Studies have found no correlation between foraminal stenosis and the outcome of epidural neuroplasty, which is thought to depend on contrast runoff. To examine the correlation between the contrast spread pattern and pain reduction in cervical epidural neuroplasty using a Racz catheter. Retrospective study. An interventional pain-management practice in a university hospital. Fluoroscopic images were reviewed retrospectively. The spread of contrast from the neural foramen to a nerve root was called contrast runoff. If the contrast did not spread in this manner, then there was no contrast runoff. We defined successful epidural neuroplasty as a 50% or greater reduction from the pre-procedure numeric rating scale (NRS) score for total pain, and an at least 40% reduction in the neck pain and disability scale (NPDS) score. This study reviewed 169 patients. Among the patients who had a contrast runoff pattern, the epidural neuroplasty was rated as successful in 96 (74.4%), 97 (75.2%), 86 (66.7%), and 79 (61.2%) cases one, 3, 6, and 12 months after the procedure, respectively. When there was no contrast runoff, the epidural neuroplasty was successful in 12 (30%), 12 (30%), 10 (25%), and 10 (25%) cases at one, 3, 6, and 12 months after the procedure (P runoff pattern had odds ratios of 6.788, 7.073, 6.000, and 4.740 at one, 3, 6, and 12 months, respectively (P runoff pattern had a higher success rate. Contrast runoff should be observed during neuroplasty, even in the presence of foraminal stenosis. Cervical spinal pain, contrast, contrast runoff, epidural neuroplasty, percutaneous adhesiolysis, Racz catheter.

  9. Evaluation of secondary environmental impacts of urban runoff pollution control

    International Nuclear Information System (INIS)

    Huibregtse, K.R.; Geinopolos, A.

    1982-03-01

    A generalized evaluation of the impacts associated with different urban stormwater runoff (UR) treatment techniques is presented. It addresses the definition of the problem, estimates the volume and characteristics of the UR and the sludges expected, evaluates six methods of UR sludge treatment, and examines alternatives and impacts for UR treatment sludge handling such as bleed/pump back to the dry weather plant, and land disposal. Regarding bleed/pump back of UR sludges, solids deposition in sewers and overload to the dry weather facilities are anticipated to cause problems. The most cost effective sludge treatment alternative appeared to be lime stabilization followed by thickening, pressure filter dewatering, and landfill disposal. Secondary impacts included costs, water quality, noise, energy consumption, air pollution, and land area requirements

  10. ALTERNATIVE DISPUTE RESOLUTION IN BANYUMAS REGENCY: IN THE PERSPECTIVE OF CULTURAL STUDIES

    Directory of Open Access Journals (Sweden)

    Singkir Hudijono

    2012-11-01

    Full Text Available This study discusses about an Alternative Dispute Resolution in BanyumasRegency as a non-litigation dispute resolution. The problem observed was a breakthroughtaken by the Society in Banyumas Regency in overcoming the so far deadlock of lawenforcement and the attitude of not trusting the justice enforcement. It has been a publicsecret that the dispute resolutions employing the legal centralism paradigm have beendominated by the judicial network. This has caused the acknowledgement of the state lawto decrease, being a commodity that can be traded. The research aims at finding out anddescribing how the alternative dispute resolution (ADR emerges as an alternativemechanism in deconstructing the legal centralism; interpreting and describing what ismeant by the alternative dispute resolution (ADR in the development of progressive law.This research was conducted employing qualitative method. In this context, theresearcher explored various pieces of related information with the reason that the societyin Banyumas Regency has chosen the alternative dispute resolution mechanism as themechanism in deconstructing the legal centralism. The research was conducted asfollows: the problems were identified, the theories for analyzing the data were selected,the primary and secondary data were collected, the collected data were analyzed andinterpreted, and finally, the results of the research were written and constructed. Thetheories employed were critical legal studies, deconstruction, and large narration criticismtheories.The results of the research show that: firstly, the alternative dispute resolution hasemerged because of the awakened local knowledge, as the form of anticipation to theineffective formal law domination. With regard to the effect of global intercourse, thealternative dispute resolution has emerged because of the refusal against the culturalhomogeneity. Secondly, the implementation of the alternative dispute resolution hasbecome the preferred

  11. Interception of rainfall and surface runoff in the Brazilian Cerrado

    Science.gov (United States)

    Tarso Oliveira, Paulo; Wendland, Edson; Nearing, Mark; Perea Martins, João

    2014-05-01

    The Brazilian Cerrado plays a fundamental role in water resources dynamics because it distributes fresh water to the largest basins in Brazil and South America. In recent decades, the native Cerrado vegetation has increasingly been replaced by agricultural crops and pasture. These land cover and land use changes have altered the hydrological processes. Meanwhile, little is known about the components of the water balance in the Brazilian Cerrado, mainly because the experimental field studies in this region are scarce or nonexistent. The objective of this study was to evaluate two hydrological processes under native Cerrado vegetation, the canopy interception (CI) and the surface runoff (R). The Cerrado physiognomy was classified as "cerrado sensu stricto denso" with an absolute density of 15,278 trees ha-1, and a basal area of 11.44 m2 ha-1. We measured the gross rainfall (P) from an automated tipping bucket rain gauge (model TB4) located in a tower with 11 m of height on the Cerrado. Throughfall (TF) was obtained from 15 automated tipping bucket rain gauges (model Davis) spread below the Cerrado vegetation and randomly relocated every month during the wet season. Stemflow (SF) was measured on 12 trees using a plastic hose wrapped around the trees trunks, sealed with neutral silicone sealant, and a bucket to store the water. The canopy interception was computed by the difference between P and the sum of TF and SF. Surface runoff under undisturbed Cerrado was collected in three plots of 100 m2(5 x 20 m) in size and slope steepness of approximately 0.09 m m-1. The experimental study was conducted between January 2012 and November 2013. We found TF of 81.0% of P and SF of 1.6% of P, i.e. the canopy interception was calculated at 17.4% of P. There was a statistically significant correlation (p 0.8. Our results suggest that the rainfall intensity, the characteristics of the trees trunks (crooked and twisted) and stand structure are the main factors that have influenced

  12. Amending greenroof soil with biochar to affect runoff water quantity and quality

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Deborah A.; Johnson, Gwynn R. [Portland State University, Mechanical and Materials Engineering, POB 751, Portland, OR 97207 (United States); Spolek, Graig A., E-mail: graig@cecs.pdx.edu [Portland State University, Mechanical and Materials Engineering, POB 751, Portland, OR 97207 (United States)

    2011-08-15

    Numbers of greenroofs in urban areas continue to grow internationally; so designing greenroof soil to reduce the amount of nutrients in the stormwater runoff from these roofs is becoming essential. This study evaluated changes in extensive greenroof water discharge quality and quantity after adding biochar, a soil amendment promoted for its ability to retain nutrients in soils and increase soil fertility. Prototype greenroof trays with and without biochar were planted with sedum or ryegrass, with barren soil trays used as controls. The greenroof trays were subjected to two sequential 7.4 cm/h rainfall events using a rain simulator. Runoff from the rain events was collected and evaluated. Trays containing 7% biochar showed increased water retention and significant decreases in discharge of total nitrogen, total phosphorus, nitrate, phosphate, and organic carbon. The addition of biochar to greenroof soil improves both runoff water quality and retention. - Highlights: > Biochar in green roof soil reduces nitrogen and phosphorus in the runoff. > Addition of biochar reduces turbidity of runoff. > Addition of biochar reduces total organic carbon content in runoff by 67-72%. > Biochar improves water retention of saturated soil. - In this controlled laboratory experiment, greenroof soil was amended by the addition of biochar, which reduced the water runoff concentration of nitrogen, phosphorus, and organic carbon.

  13. Runoff measurement and prediction for a watershed under natural vegetation in central Brazil

    Directory of Open Access Journals (Sweden)

    C. L. Silva

    1999-09-01

    Full Text Available This work aimed to measure and analyze total rainfall (P, rainfall intensity and five-day antecedent rainfall effects on runoff (R; to compare measured and simulated R values using the Soil Conservation Service Curve Number method (CN for each rainfall event; and to establish average R/P ratios for observed R values. A one-year (07/01/96 to 06/30/97 rainfall-runoff data study was carried out in the Capetinga watershed (962.4 ha, located at the Federal District of Brazil, 47° 52' longitude West and 15° 52' latitude South. Soils of the watershed were predominantly covered by natural vegetation. Total rainfall and runoff for the period were 1,744 and 52.5 mm, respectively, providing R/P of 3% and suggesting that watershed physical characteristics favored water infiltration into the soil. A multivariate regression analysis for 31 main rainfall-runoff events totaling 781.9 and 51.0 mm, respectively, indicated that the amount of runoff was only dependent upon rainfall volume. Simulated values of total runoff were underestimated about 15% when using CN method and an area-weighted average of the CN based on published values. On the other hand, when average values of CN were calculated for the watershed, total runoff was overestimated about 39%, suggesting that CN method shoud be used with care in areas under natural vegetation.

  14. Change detection of runoff-urban growth relationship in urbanised watershed

    International Nuclear Information System (INIS)

    Abas, Aisya Azizah; Hashim, Mazlan

    2014-01-01

    Urban growth has negative environmental impacts that create water-based disasters such as flash floods and storm runoff causing billions of dollars worth of damage each year. Due to serious flash floods in urbanised areas of Malaysia, water resource management is a vital issue. This paper reports on a study that has been carried out using remote sensing techniques and hydrological modelling for examining the spatial patterns changes of urban areas and its impacts on surface runoff. The estimation of surface runoff based on the Soil Conservation Service Curve Number (SCS CN) method was performed by integrating both remote sensing and Geographic Information System (GIS) techniques. Remote sensing is a data sources for monitoring urban growth by quantifying the changes of urban area and its environmental impact are then analysed by using a GIS-based hydrological model. By linking the integrated approach of remote sensing and GIS, the relationship of runoff with urban expansion are further examined. Hence, the changes in runoff due to urbanisation are analysed. This methodology is applied to the central region of Malaysia in Kuala Lumpur, where rapid urban growth has occurred over the last decade. The results showed that there was a significant between spatial patterns of urban growth and estimated runoff depth. The increase in runoff from year 2000, 2006 and 2010 are estimated about five percent

  15. Enrichment behavior and transport mechanism of soil-bound PAHs during rainfall-runoff events

    International Nuclear Information System (INIS)

    Zheng Yi; Luo Xiaolin; Zhang Wei; Wu Bin; Han Feng; Lin Zhongrong; Wang Xuejun

    2012-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) transported by surface runoff result in nonpoint source pollution and jeopardize aquatic ecosystems. The transport mechanism of PAHs during rainfall-runoff events has been rarely studied regarding pervious areas. An experimental system was setup to simulate the runoff pollution process on PAHs-contaminated soil. The enrichment behavior of soil-bound PAHs was investigated. The results show that soil organic matters (SOM), rather than clay particles, seem to be the main carrier of PAHs. The enrichment is highly conditioned on runoff and erosion processes, and its magnitude varies among PAH compounds. It is not feasible to build a simple and universal relationship between enrichment ratio and sediment discharge following the traditional enrichment theory. To estimate the flux of PAHs from pervious areas, soil erosion process has to be clearly understood, and both organic carbon content and composition of SOM should be factored into the calculation. - Highlights: ► Significant enrichment of particle-bound PAHs during rainfall-runoff events. ► Organic matters as the direct carrier of PAHs in runoff from contaminated soil. ► The traditional enrichment theory is not fully valid for PAHs. - The traditional enrichment theory is not fully valid for PAHs, and soil organic matters have a significant impact on the transport of PAHs during rainfall-runoff events.

  16. Can arbuscular mycorrhiza and fertilizer management reduce phosphorus runoff from paddy fields?

    Science.gov (United States)

    Zhang, Shujuan; Wang, Li; Ma, Fang; Zhang, Xue; Li, Zhe; Li, Shiyang; Jiang, Xiaofeng

    2015-07-01

    Our study sought to assess how much phosphorus (P) runoff from paddy fields could be cut down by fertilizer management and inoculation with arbuscular mycorrhizal fungi. A field experiment was conducted in Lalin River basin, in the northeast China: six nitrogen-phosphorus-potassium fertilizer levels were provided (0, 20%, 40%, 60%, 80%, and 100% of the recommended fertilizer supply), with or without inoculation with Glomus mosseae. The volume and concentrations of particle P (PP) and dissolved P (DP) were measured for each runoff during the rice growing season. It was found that the seasonal P runoff, including DP and PP, under the local fertilization was 3.7 kg/ha, with PP, rather than DP, being the main form of P in runoff water. Additionally, the seasonal P runoff dropped only by 8.9% when fertilization decreased by 20%; rice yields decreased with declining fertilization. We also found that inoculation increased rice yields and decreased P runoff at each fertilizer level and these effects were lower under higher fertilization. Conclusively, while rice yields were guaranteed arbuscular mycorrhizal inoculation and fertilizer management would play a key role in reducing P runoff from paddy fields. Copyright © 2015. Published by Elsevier B.V.

  17. The development of an ecological approach to manage the pollution risk from highway runoff.

    Science.gov (United States)

    Crabtree, B; Dempsey, P; Johnson, I; Whitehead, M

    2009-01-01

    In the UK, the Highways Agency is responsible for operating, maintaining and improving the strategic road network in England. One focus of the Highways Agency's ongoing research into the nature and impact of highway runoff is aimed at ensuring that the Highways Agency will meet the requirements of the EU Water Framework Directive. A research programme, undertaken in partnership with the Environment Agency, is in progress to develop a better understanding of pollutants in highway runoff and their ecological impact. The paper presents the outcome of a study to: (1) monitor pollutants in highway runoff under different climate and traffic conditions; (2) develop standards to assess potential ecological risks from soluble pollutants in highway runoff; and (3) develop a model to predict pollutant concentrations in highway runoff. The model has been embedded in a design tool incorporating risk assessment procedures and receiving water standards for soluble and insoluble pollutants--the latter has been developed elsewhere in another project within the research programme. The design tool will be used to support improved guidance on where, and to what level, treatment of runoff is required for highway designers to manage the risk of ecological impact from highway runoff.

  18. Amending greenroof soil with biochar to affect runoff water quantity and quality

    International Nuclear Information System (INIS)

    Beck, Deborah A.; Johnson, Gwynn R.; Spolek, Graig A.

    2011-01-01

    Numbers of greenroofs in urban areas continue to grow internationally; so designing greenroof soil to reduce the amount of nutrients in the stormwater runoff from these roofs is becoming essential. This study evaluated changes in extensive greenroof water discharge quality and quantity after adding biochar, a soil amendment promoted for its ability to retain nutrients in soils and increase soil fertility. Prototype greenroof trays with and without biochar were planted with sedum or ryegrass, with barren soil trays used as controls. The greenroof trays were subjected to two sequential 7.4 cm/h rainfall events using a rain simulator. Runoff from the rain events was collected and evaluated. Trays containing 7% biochar showed increased water retention and significant decreases in discharge of total nitrogen, total phosphorus, nitrate, phosphate, and organic carbon. The addition of biochar to greenroof soil improves both runoff water quality and retention. - Highlights: → Biochar in green roof soil reduces nitrogen and phosphorus in the runoff. → Addition of biochar reduces turbidity of runoff. → Addition of biochar reduces total organic carbon content in runoff by 67-72%. → Biochar improves water retention of saturated soil. - In this controlled laboratory experiment, greenroof soil was amended by the addition of biochar, which reduced the water runoff concentration of nitrogen, phosphorus, and organic carbon.

  19. Effects of runoff sensitivity and catchment characteristics on regional actual evapotranspiration trends in the conterminous US

    International Nuclear Information System (INIS)

    Jung, Il Won; Chang, Heejun; Risley, John

    2013-01-01

    An understanding of the role of hydro-climatic and geographic regimes on regional actual evapotranspiration (AET) change is essential to improving our knowledge on predicting water availability in a changing climate. This study investigates the relationship between AET change for a 60 year period (1951–2010) and the runoff sensitivity in 255 undisturbed catchments over the US. The runoff sensitivity to climate change is simply defined as the relative magnitude between runoff and precipitation changes with time. Runoff sensitivity can readily explain the conflicting directions of AET changes under similar precipitation change. Under increasing precipitation, AET decreases when runoff is increasing more rapidly than precipitation based on the water balance. Conversely, AET increases when runoff is decreasing more rapidly than precipitation. This result indicates that runoff sensitivity to climate change is a key factor for understanding regional water availability change at the catchment scale. In addition, a stepwise multiple regression analysis and a geographically weighted regression analysis show that the portion of evergreen forest and the mean elevation of a catchment may play a secondary role in the spatial pattern of the AET change, and the relative importance of such explanatory variables may change over space. (letter)

  20. Impact of climate variability on runoff in the north-central United States

    Science.gov (United States)

    Ryberg, Karen R.; Lin, Wei; Vecchia, Aldo V.

    2014-01-01

    Large changes in runoff in the north-central United States have occurred during the past century, with larger floods and increases in runoff tending to occur from the 1970s to the present. The attribution of these changes is a subject of much interest. Long-term precipitation, temperature, and streamflow records were used to compare changes in precipitation and potential evapotranspiration (PET) to changes in runoff within 25 stream basins. The basins studied were organized into four groups, each one representing basins similar in topography, climate, and historic patterns of runoff. Precipitation, PET, and runoff data were adjusted for near-decadal scale variability to examine longer-term changes. A nonlinear water-balance analysis shows that changes in precipitation and PET explain the majority of multidecadal spatial/temporal variability of runoff and flood magnitudes, with precipitation being the dominant driver. Historical changes in climate and runoff in the region appear to be more consistent with complex transient shifts in seasonal climatic conditions than with gradual climate change. A portion of the unexplained variability likely stems from land-use change.

  1. Runoff and Evapotranspiration Sensitivities to a Changing Climate in the Western U.S.

    Science.gov (United States)

    Gao, M.; Xiao, M.; Lettenmaier, D. P.

    2017-12-01

    Climate change is likely to alter streamflow seasonal patterns, affect water availability, and otherwise pose challenges to water resources management. It is therefore important to understand how streamflow will respond to changes in climate. Previous studies have mostly focused on runoff sensitivity to precipitation (P) and temperature change, but runoff sensitivity to potential evapotranspiration (PET) is less well understood. In order to investigate how variations in precipitation and PET influence runoff, we conducted both statistical and model-based analyses of 84 near-natural basins in California, Oregon, and Washington. We obtained meteorological forcing data at 1/16 degree spatial resolution for each basin from the University of Washington/UCLA Experimental Surface Water Monitor, and observed runoff data from USGS. For the statistical method, we applied three estimators of the precipitation elasticity of runoff from previous studies. We also estimated the PET elasticity of runoff, using Penman-Monteith reference ET as a surrogate for PET. For the modelling method, we implemented the Sacramento Soil Moisture Accounting (SAC-SMA) Model, where PET is an explicit input. We performed experiments in which we changed P and PET by 1% individually to examine their effects on runoff, from which we computed the P and PET elasticities. We explore the spatial patterns in the elasticities of runoff and their relationships with basin characteristics and climatology. We also evaluate how well the statistical and model-based results meet the complementary relationship posited by Dooge (based on the Budyko Hypothesis) that the precipitation and PET elasticities of annual runoff should sum to one.

  2. Phosphorus runoff from waste water treatment biosolids and poultry litter applied to agricultural soils.

    Science.gov (United States)

    White, John W; Coale, Frank J; Sims, J Thomas; Shober, Amy L

    2010-01-01

    Differences in the properties of organic phosphorus (P) sources, particularly those that undergo treatment to reduce soluble P, can affect soil P solubility and P transport in surface runoff. This 2-yr field study investigated soil P solubility and runoff P losses from two agricultural soils in the Mid-Atlantic region after land application of biosolids derived from different waste water treatment processes and poultry litter. Phosphorus speciation in the biosolids and poultry litter differed due to treatment processes and significantly altered soil P solubility and dissolved reactive P (DRP) and bioavailable P (FeO-P) concentrations in surface runoff. Runoff total P (TP) concentrations were closely related to sediment transport. Initial runoff DRP and FeO-P concentrations varied among the different biosolids and poultry litter applied. Over time, as sediment transport declined and DRP concentrations became an increasingly important component of runoff FeO-P and TP, total runoff P was more strongly influenced by the type of biosolids applied. Throughout the study, application of lime-stabilized biosolids and poultry litter increased concentrations of soil-soluble P, readily desorbable P, and soil P saturation, resulting in increased DRP and FeO-P concentrations in runoff. Land application of biosolids generated from waste water treatment processes that used amendments to reduce P solubility (e.g., FeCl(3)) did not increase soil P saturation and reduced the potential for DRP and FeO-P transport in surface runoff. These results illustrate the importance of waste water treatment plant process and determination of specific P source coefficients to account for differential P availability among organic P sources.

  3. Transport of three veterinary antimicrobials from feedlot pens via simulated rainfall runoff.

    Science.gov (United States)

    Sura, Srinivas; Degenhardt, Dani; Cessna, Allan J; Larney, Francis J; Olson, Andrew F; McAllister, Tim A

    2015-07-15

    Veterinary antimicrobials are introduced to wider environments by manure application to agricultural fields or through leaching or runoff from manure storage areas (feedlots, stockpiles, windrows, lagoons). Detected in manure, manure-treated soils, and surface and ground water near intensive cattle feeding operations, there is a concern that environmental contamination by these chemicals may promote the development of antimicrobial resistance in bacteria. Surface runoff and leaching appear to be major transport pathways by which veterinary antimicrobials eventually contaminate surface and ground water, respectively. A study was conducted to investigate the transport of three veterinary antimicrobials (chlortetracycline, sulfamethazine, tylosin), commonly used in beef cattle production, in simulated rainfall runoff from feedlot pens. Mean concentrations of veterinary antimicrobials were 1.4 to 3.5 times higher in surface material from bedding vs. non-bedding pen areas. Runoff rates and volumetric runoff coefficients were similar across all treatments but both were significantly higher from non-bedding (0.53Lmin(-1); 0.27) than bedding areas (0.40Lmin(-1); 0.19). In keeping with concentrations in pen surface material, mean concentrations of veterinary antimicrobials were 1.4 to 2.5 times higher in runoff generated from bedding vs. non-bedding pen areas. Water solubility and sorption coefficient of antimicrobials played a role in their transport in runoff. Estimated amounts of chlortetracycline, sulfamethazine, and tylosin that could potentially be transported to the feedlot catch basin during a one in 100-year precipitation event were 1.3 to 3.6ghead(-1), 1.9ghead(-1), and 0.2ghead(-1), respectively. This study demonstrates the magnitude of veterinary antimicrobial transport in feedlot pen runoff and supports the necessity of catch basins for runoff containment within feedlots. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  4. Runoff of pyrethroid insecticides from concrete surfaces following simulated and natural rainfalls.

    Science.gov (United States)

    Jiang, Weiying; Haver, Darren; Rust, Michael; Gan, Jay

    2012-03-01

    Intensive residential use of insecticides has resulted in their ubiquitous presence as contaminants in urban surface streams. For pest eradication, urban hard surfaces such as concrete are often directly treated with pesticides, and wind/water can also carry pesticides onto hard surfaces from surrounding areas. This study expanded on previous bench-scale studies by considering pesticide runoff caused by irrigation under dry weather conditions and rain during the wet season, and evaluated the effects of pesticide residence time on concrete, single versus recurring precipitations, precipitation intensity, and concrete surface conditions, on pesticide transferability to runoff water. Runoff from concrete 1 d after pesticide treatment contained high levels of bifenthrin (82 μg/L) and permethrin (5143 μg/L for cis and 5518 μg/L for trans), indicating the importance of preventing water contact on concrete after pesticide treatments. Although the runoff transferability quickly decreased as the pesticide residence time on concrete increased, detectable residues were still found in runoff water after 3 months (89 d) exposure to hot and dry summer conditions. ANOVA analysis showed that precipitation intensities and concrete surface conditions (i.e., acid wash, silicone seal, stamping, and addition of microsilica) did not significantly affect the pesticide transferability to runoff. For concrete slabs subjected to natural rainfalls during the winter wet season, pesticide levels in the runoff decreased as the time interval between pesticide application and the rain event increased. However, bifenthrin and permethrin were still detected at 0.15-0.17 and 0.75-1.15 μg/L in the rain runoff after 7 months (221 d) from the initial treatment. In addition, pesticide concentrations showed no decrease between the two rainfall events, suggesting that concrete surfaces contaminated by pesticides may act as a reservoir for pesticide residues, leading to sustained urban runoff

  5. Statistical analysis and modelling of surface runoff from arable fields

    OpenAIRE

    P. Fiener; K. Auerswald; F. Winter; M. Disse

    2013-01-01

    Surface runoff generation on arable fields is an important driver of (local) flooding, on-site and off-site damages by erosion, and of nutrient and agrochemical transport. In general, three different processes generate surface runoff (Hortonian runoff, saturation excess runoff, and return of subsurface flow). Despite the developments in our understanding of these processes it remains difficult to predict, which processes govern runoff generation during the course of an event or through...

  6. Analyzing temporal changes in maximum runoff volume series of the Danube River

    International Nuclear Information System (INIS)

    Halmova, Dana; Pekarova, Pavla; Onderka, Milan; Pekar, Jan

    2008-01-01

    Several hypotheses claim that more extremes in climatic and hydrologic phenomena are anticipated. In order to verify such hypotheses it is inevitable to examine the past periods by thoroughly analyzing historical data. In the present study, the annual maximum runoff volumes with t-day durations were calculated for a 130-year series of mean daily discharge of Danube River at Bratislava gauge (Slovakia). Statistical methods were used to clarify how the maximum runoff volumes of the Danube River changed over two historical periods (1876-1940 and 1941-2005). The conclusion is that the runoff volume regime during floods has not changed significantly during the last 130 years.

  7. Initial conditions of urban permeable surfaces in rainfall-runoff models using Horton’s infiltration

    DEFF Research Database (Denmark)

    Davidsen, Steffen; Löwe, Roland; Høegh Ravn, Nanna

    2017-01-01

    Infiltration is a key process controlling runoff, but varies depending on antecedent conditions. This study provides estimates on initial conditions for urban permeable surfaces via continuous simulation of the infiltration capacity using historical rain data. An analysis of historical rainfall...... records show that accumulated rainfall prior to large rain events does not depend on the return period of the event. Using an infiltration-runoff model we found that for a typical large rain storm, antecedent conditions in general lead to reduced infiltration capacity both for sandy and clayey soils...... and that there is substantial runoff for return periods above 1–10 years....

  8. Report on the Savannah River Site aluminum-based spent nuclear fuel alternatives cost study

    International Nuclear Information System (INIS)

    1998-12-01

    Initial estimates of costs for the interim management and disposal of aluminum-based spent nuclear fuel (SNF) were developed during preparation of the Environmental Impact Statement (EIS) on the Nuclear Weapons Nonproliferation Policy Concerning Foreign Research Reactor Spent Nuclear Fuel. The Task Team evaluated multiple alternatives, assessing programmatic, technical, and schedule risks, and generated life-cycle cost projections for each alternative. The eight technology alternatives evaluated were: direct co-disposal; melt and dilute; reprocessing; press and dilute; glass material oxidation dissolution system (GMODS); electrometallurgical treatment; dissolve and vitrify; and plasma arc. In followup to the Business Plan that was developed to look at SNF dry storage, WSRC prepared an addendum to the cost study. This addendum estimated the costs for the modification and use of an existing (105L) reactor facility versus a greenfield approach for new facilities (for the Direct Co-Disposal and Melt and Dilute alternatives). WSRC assessed the impacts of a delay in reprocessing due to the potential reservation of H-Canyon for other missions (i.e., down blending HEU for commercial use or the conversion of plutonium to either MOX fuel or an immobilized repository disposal form). This report presents the relevant results from these WSRC cost studies, consistent with the most recent project policy, technology implementation, canyon utilization, and inventory assumptions. As this is a summary report, detailed information on the technical alternatives or the cost assumptions raised in each of the above-mentioned cost studies is not provided. A comparison table that briefly describes the bases used for the WSRC analyses is included as Appendix A

  9. A test system to quantify inoculum in runoff from Phytophthora ramorum-infected plant roots

    Science.gov (United States)

    Nina. Shishkoff

    2010-01-01

    Foliar hosts of Phytophthora ramorum are often susceptible to root infection, but the epidemiological significance of such infections is unknown. We used a standardized test system to study inoculum in runoff from root-infected Viburnum tinus cuttings.

  10. Evaluation of Surface Runoff Water in a Freshwater Confined Disposal Facility - Effects of Vegetation

    National Research Council Canada - National Science Library

    Price, R

    2002-01-01

    The U.S. Army Engineer Research and Development Center, Vicksburg, MS, is conducting a series of laboratory and field studies to determine the effectiveness of the Simplified Laboratory Runoff Procedure (SLRP...

  11. Treatment of highway runoff : engineered filter media for pollutant removal through enhanced sorption : final report.

    Science.gov (United States)

    2015-07-27

    The work performed in this study focused on the investigation of the use of engineered biofiltration layers to enhance the removal of roadway stormwater runoff contaminants (specifically nutrients, solids, heavy metals, and pH). Six Georgia native gr...

  12. Extracting information from an ensemble of GCMs to reliably assess future global runoff change

    NARCIS (Netherlands)

    Sperna Weiland, F.C.; Beek, L.P.H. van; Weerts, A.H.; Bierkens, M.F.P.

    2011-01-01

    Future runoff projections derived from different global climate models (GCMs) show large differences. Therefore, within this study the, information from multiple GCMs has been combined to better assess hydrological changes. For projections of precipitation and temperature the Reliability ensemble

  13. Nitrogen and phosphorus associating with different size suspended solids in roof and road runoff in Beijing, China.

    Science.gov (United States)

    Wu, Junliang; Ren, Yufen; Wang, Xuemei; Wang, Xiaoke; Chen, Liding; Liu, Gangcai

    2015-10-01

    Roofs and roads, accounting for a large portion of the urban impervious land surface, have contributed significantly to urban nonpoint pollution. In this study, in Beijing, China, roof and road runoff are sampled to measure the suspended solids (SS), nitrogen (N), and phosphorus (P) contained in particles with different sizes. The SS content in the road runoff (151.59 mg/L) was sevenfold that in the roof runoff (21.13 mg/L, p runoff than in road runoff. The small particulates in the range of 0.45-50 μm consisted of 59 % SS in the roof runoff and 94 % SS in the road runoff. P was mainly attached to particle sizes of 10-50 μm in the roof (73 %) and road (48 %) runoffs, while N was mainly in a dissolved phase state in both runoffs. So, the different associations of N and P raise a challenge in preventing stormwater pollution in urban environments.

  14. Combined effects of rainfall regime and plot length on runoff and soil loss in the Loess Plateau of China

    Science.gov (United States)

    Liu, J.; Gao, G.; Wang, S.; Fu, B.

    2017-12-01

    The purpose of this paper was to study the interaction effects of rainfall regime and slope length on runoff and soil loss under different land uses. Event runoff and soil loss of forest, shrub and grass were measured in plots with length of 5, 9, or 13 m in the Loess Plateau from 2008 to 2016. Fifty-nine erosive rainfall events were recorded and classified into three rainfall regimes. The results firstly showed that the runoff coefficient was grass > shrub > forest, and soil loss was grass > forest > shrub, but the differences between forest and shrub in runoff and between grass and forest in soil loss didn't reach significant level. Secondly, rainfall regimes had important effect on runoff and soil loss of different land uses. The lowest runoff coefficients and the highest soil loss in regime 2 were found in shrub and forest land, respectively, which differed from that of regime 1. In total, rainfall regime 1 had the highest runoff coefficient of 0.84-2.06%, followed by regime 3 with 0.33-0.88%, and regime 2 with 0.04-0.06%. Soil loss in forest and grass land had a different order of regime 3 > regime 1 > regime 2. Thirdly, both the runoff coefficient and soil loss decreased with increasing plot length, while the effect of slope length on runoff/soil loss were influenced by land use type and rainfall regimes.

  15. Use of alternative medicine for hypertension in Buikwe and Mukono districts of Uganda: a cross sectional study.

    Science.gov (United States)

    Nuwaha, Fred; Musinguzi, Geofrey

    2013-11-04

    Use of alternative medicine for chronic diseases such as hypertension is common in low as well as high income countries. This study estimated the proportion of people who were aware of their hypertension that use alternative medicine and identified factors predicting the use of alternative medicine. In a community based cross sectional survey among people ≥ 15 years in Buikwe and Mukono districts of Uganda 258 people aware of their hypertension were questioned about use of alternative medicine for hypertension, advice about uptake of life style intervention for hypertension control such as reduction of salt intake and about their attitude towards use of alternative medicine. Proportions of people who used alternative medicine and adopt life style interventions and their 95% confidence intervals (CI) were calculated. Predictors of using alternative medicine were identified using logistic binary regression analysis. More than a half 144 (56.2%) had ever used alternative medicine whereas more than one in four 74 (28.6%) were currently using alternative medicine alone or in combination with modern medicine (50%). People who were using alternative medicine alone (29.7% CI 17.5-45.9) were less likely to have received advice on reduction of salt intake compared to those using modern medicine alone or in combination with traditional medicine (56.6%, CI 47.7-65.0). The only independent predictor for using alternative medicine was agreeing that alternative medicine is effective for treatment of hypertension (adjusted odds ratio [AOR] 2.6; 95% CI 1.40-4.82). The use of alternative medicine was common among patients with hypertension and usage was underpinned by the belief that alternative medicine is effective. As patients with hypertension use alternative medicine and modern medicine concurrently, there is need for open communication between health workers and patients regarding use of alternative medicine.

  16. Phosphorus runoff from turfgrass as affected by phosphorus fertilization and clipping management.

    Science.gov (United States)

    Bierman, Peter M; Horgan, Brian P; Rosen, Carl J; Hollman, Andrew B; Pagliari, Paulo H

    2010-01-01

    Phosphorus enrichment of surface water is a concern in many urban watersheds. A 3-yr study on a silt loam soil with 5% slope and high soil test P (27 mg kg(-1) Bray P1) was conducted to evaluate P fertilization and clipping management effects on P runoff from turfgrass (Poa pratensis L.) under frozen and nonfrozen conditions. Four fertilizer treatments were compared: (i) no fertilizer, (ii) nitrogen (N)+potassium (K)+0xP, (iii) N+K+1xP, and (iv) N+K+3xP. Phosphorus rates were 21.3 and 63.9 kg ha(-1) yr(-1) the first year and 7.1 and 21.3 kg ha(-1) yr(-1) the following 2 yr. Each fertilizer treatment was evaluated with clippings removed or clippings recycled back to the turf. In the first year, P runoff increased with increasing P rate and P losses were greater in runoff from frozen than nonfrozen soil. In year 2, total P runoff from the no fertilizer treatment was greater than from treatments receiving fertilizer. This was because reduced turf quality resulted in greater runoff depth from the no fertilizer treatment. In year 3, total P runoff from frozen soil and cumulative total P runoff increased with increasing P rate. Clipping management was not an important factor in any year, indicating that returning clippings does not significantly increase P runoff from turf. In the presence of N and K, P fertilization did not improve turf growth or quality in any year. Phosphorus runoff can be reduced by not applying P to high testing soils and avoiding fall applications when P is needed.

  17. Dairy diet phosphorus and rainfall timing effects on runoff phosphorus from land-applied manure.

    Science.gov (United States)

    Hanrahan, Laura P; Jokela, William E; Knapp, Joanne R

    2009-01-01

    Surface-applied dairy manure can increase P concentrations in runoff, which may contribute to eutrophication of lakes and streams. The amount of dietary P fed to dairy cows (Bos taurus) and the timing of a rain event after manure application may further affect runoff P losses. The objective of this study was to examine dietary P supplementation effects on manure and runoff P concentrations from rain events occurring at different time intervals after manure application. Manure from dairy cows fed an unsupplemented low P diet (LP; 3.6 g P kg(-1)) or a diet supplemented with either an inorganic (HIP; 4.4 g P kg(-1)) or an organic (HOP; 4.6 g P kg(-1)) source was hand-applied onto soil-packed pans at 56 wet Mg ha(-1). Thirty min of runoff was collected from simulated rain events (30 mm h(-1)) 2, 5, or 9 d after manure application. Total P (TP) concentrations in runoff from HIP and HOP diet manure from the 2-d rain were 46 and 31% greater than that of the LP diet. Runoff P concentrations from high P diets were numerically higher than that of the LP diet at 5 and 9 d after application, but differences were significant only for dissolved reactive P (DRP) at 5 d. Large decreases in runoff TP (89%) and DRP (65%) concentrations occurred with delay of rainfall from 2 d until 5 d. The proportion of TP as DRP increased as the time between manure application and runoff increased. Results showed that reducing dietary P and extending the time between manure application and a rain event can significantly reduce concentrations of TP and DRP in runoff.

  18. Alternatives to the face-to-face consultation in general practice: focused ethnographic case study.

    Science.gov (United States)

    Atherton, Helen; Brant, Heather; Ziebland, Sue; Bikker, Annemieke; Campbell, John; Gibson, Andy; McKinstry, Brian; Porqueddu, Tania; Salisbury, Chris

    2018-04-01

    NHS policy encourages general practices to introduce alternatives to the face-to-face consultation, such as telephone, email, e-consultation systems, or internet video. Most have been slow to adopt these, citing concerns about workload. This project builds on previous research by focusing on the experiences of patients and practitioners who have used one or more of these alternatives. To understand how, under what conditions, for which patients, and in what ways, alternatives to face-to-face consultations present benefits and challenges to patients and practitioners in general practice. Focused ethnographic case studies took place in eight UK general practices between June 2015 and March 2016. Non-participant observation, informal conversations with staff, and semi-structured interviews with staff and patients were conducted. Practice documents and protocols were reviewed. Data were analysed through charting and the 'one sheet of paper' mind-map method to identify the line of argument in each thematic report. Case study practices had different rationales for offering alternatives to the face-to-face consultation. Beliefs varied about which patients and health issues were suitable. Co-workers were often unaware of each other's practice; for example, practice policies for use of e-consultations systems with patients were not known about or followed. Patients reported benefits including convenience and access. Staff and some patients regarded the face-to-face consultation as the ideal. Experience of implementing alternatives to the face-to-face consultation suggests that changes in patient access and staff workload may be both modest and gradual. Practices planning to implement them should consider carefully their reasons for doing so and involve the whole practice team. © British Journal of General Practice 2018.

  19. Life cycle assessment of the use of alternative fuels in cement kilns: A case study.

    Science.gov (United States)

    Georgiopoulou, Martha; Lyberatos, Gerasimos

    2018-06-15

    The benefits of using alternative fuels (AFs) in the cement industry include reduction of the use of non-renewable fossil fuels and lower emissions of greenhouse gases, since fossil fuels are replaced with materials that would otherwise be degraded or incinerated with corresponding emissions and final residues. Furthermore, the use of alternative fuels maximizes the recovery of energy. Seven different scenaria were developed for the production of 1 ton of clinker in a rotary cement kiln. Each of these scenaria includes the use of alternative fuels such as RDF (Refuse derived fuel), TDF (Tire derived fuel) and BS (Biological sludge) or a mixture of them, in partial replacement of conventional fuels such as coal and pet coke. The purpose of this study is to evaluate the environmental impacts of the use of alternative fuels in relation to conventional fuels in the kiln operation. The Life Cycle Assessment (LCA) methodology is used to quantify the potential environmental impacts in each scenario. The interpretation of the results provides the conclusion that the most environmentally friendly prospect is the scenario based on RDF while the less preferable scenario is the scenario based on BS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. B cell remote-handled waste shipment cask alternatives study; TOPICAL

    International Nuclear Information System (INIS)

    RIDDELLE, J.G.

    1999-01-01

    The decommissioning of the 324 Facility B Cell includes the onsite transport of grouted remote-handled radioactive waste from the 324 Facility to the 200 Areas for disposal. The grouted waste has been transported in the leased ATG Nuclear Services 3-82B Radioactive Waste Shipping Cask (3-82B cask). Because the 3-82B cask is a U.S. Nuclear Regulatory Commission (NRC)-certified Type B shipping cask, the lease cost is high, and the cask operations in the onsite environment may not be optimal. An alternatives study has been performed to develop cost and schedule information on alternative waste transportation systems to assist in determining which system should be used in the future. Five alternatives were identified for evaluation. These included continued lease of the 3-82B cask, fabrication of a new 3-82B cask, development and fabrication of an onsite cask, modification of the existing U.S. Department of Energy-owned cask (OH-142), and the lease of a different commercially available cask. Each alternative was compared to acceptance criteria for use in the B Cell as an initial screening. Only continued leasing of the 3-82B cask, fabrication of a new 3-82B cask, and the development and fabrication of an onsite cask were found to meet all of the B Cell acceptance criteria

  1. A Rainfall Simulator for the in situ Study of Superficial Runoff and Soil Erosion Un simulador de lluvia para el estudio in situ de la escorrentía superficial y la erosión de suelos

    Directory of Open Access Journals (Sweden)

    Claudia Sangüesa

    2010-03-01

    Full Text Available A rainfall simulator is an important tool for the study of runoff generation and soil loss because it can be used either under laboratory conditions, or in disturbed or natural soil. The objective of this study was to describe the design and operation of a rainfall simulator to evaluate soil loss in situ. The rainfall simulator has four full-cone spray nozzles with a Unijet system mounted in a straight line pipe configuration, and easily transported and assembled. Simulated rainfall uniformity was evaluated in the laboratory, whereas the applicability of the simulator in natural soil erosion plot conditions in an experimental field with different slopes was tested by quantifying runoff and evaluating soil erosion. Twenty simulations were carried out in the laboratory and sixteen in the field with slopes of 11, 21, and 39%. Four water-sprinklers in a straight line generated rainfall with uniformity close to 90%. The constructed simulator was easy to use and low cost, facilitating the necessary experimental replicates to achieve a suitable spatial representation of superficial runoff and soil loss on hillsides.El simulador de lluvia es una herramienta importante que permite estudiar los procesos de pérdida de suelo y escorrentía generados por la acción de la lluvia; éste puede utilizarse en laboratorio, bajo condiciones de suelo removido, o en terreno en condiciones naturales de suelo. El objetivo de este estudio fue describir el diseño y el funcionamiento de un simulador de lluvia construido para medir la pérdida de suelo in situ. El simulador de lluvia tenía cuatro boquillas de aspersión de cono lleno con sistema Unijet (Spray nozzles ubicados en línea, alimentadas mediante un sistema de tuberías de fácil transporte y montaje. En pruebas de laboratorio se evaluó la uniformidad de la lluvia generada; mientras que en terreno se evaluó la aplicabilidad del simulador sobre parcelas de erosión ubicadas en laderas naturales con

  2. Investigation of Quality and Reclamation of Urban Storm Runoff in City of Shiraz

    Directory of Open Access Journals (Sweden)

    Mohammad Parvinnia

    2008-06-01

    Full Text Available Urban storm runoff is considered as a potentially reclaimable and valuable resource in many arid and semiarid areas, in Iran. Urban storm runoff in Shiraz is collected mainly by Khoshk River and transported to the Maharloo Lake without any treatment or reclamation. In this study, storm runoff quality and the possibility for its reclamation from different parts of the city in certain canals and pipes are investigated. The quality of the first flush in three relatively large and small suburban areas with different land uses is studied. For the purposes of this study, three stations were considered: one near the downstream end of the city on Khoshk River with a relatively large watershed, one in the middle of the city where street runoff is the main constituent of the flush, and a third one near the western outskirts of the city with relatively small mainly residential watershed.

  3. An Independent Evaluation of the FMEA/CIL Hazard Analysis Alternative Study

    Science.gov (United States)

    Ray, Paul S.

    1996-01-01

    The present instruments of safety and reliability risk control for a majority of the National Aeronautics and Space Administration (NASA) programs/projects consist of Failure Mode and Effects Analysis (FMEA), Hazard Analysis (HA), Critical Items List (CIL), and Hazard Report (HR). This extensive analytical approach was introduced in the early 1970's and was implemented for the Space Shuttle Program by NHB 5300.4 (1D-2. Since the Challenger accident in 1986, the process has been expanded considerably and resulted in introduction of similar and/or duplicated activities in the safety/reliability risk analysis. A study initiated in 1995, to search for an alternative to the current FMEA/CIL Hazard Analysis methodology generated a proposed method on April 30, 1996. The objective of this Summer Faculty Study was to participate in and conduct an independent evaluation of the proposed alternative to simplify the present safety and reliability risk control procedure.

  4. Substance use and dietary practices among students attending alternative high schools: results from a pilot study

    OpenAIRE

    Arcan, Chrisa; Kubik, Martha Y; Fulkerson, Jayne A; Hannan, Peter J; Story, Mary

    2011-01-01

    Abstract Background Substance use and poor dietary practices are prevalent among adolescents. The purpose of this study was to examine frequency of substance use and associations between cigarette, alcohol and marijuana use and selected dietary practices, such as sugar-sweetened beverages, high-fat foods, fruits and vegetables, and frequency of fast food restaurant use among alternative high school students. Associations between multi-substance use and the same dietary practices were also exa...

  5. Simulation on Change Law of Runoff, Sediment and Non-point Source Nitrogen and Phosphorus Discharge under Different Land uses Based on SWAT Model: A Case Study of Er hai Lake Small Watershed

    Science.gov (United States)

    Tong, Xiao Xia; Lai Cui, Yuan; Chen, Man Yu; Hu, Bo; Xu, Wen Sheng

    2018-05-01

    The Er yuan watershed of Er hai district is chosen as the research area, the law of runoff and sediment and non-point source nitrogen and phosphorus discharges under different land uses during 2001 to 2014 are simulated based on SWAT model. Results of simulation indicate that the order of total runoff yield of different land use type from high to low is grassland, paddy fields, dry land. Specifically, the order of surface runoff yield from high to low is paddy fields, dry land, grassland, the order of lateral runoff yield from high to low is paddy fields, dry land, grassland, the order of groundwater runoff yield from high to low is grassland, paddy fields, dry land. The orders of sediment and nitrogen and phosphorus yield per unit area of different land use type are the same, grassland> paddy fields> dry land. It can be seen, nitrogen and phosphorus discharges from paddy fields and dry land are the main sources of agricultural non-point pollution of the irrigated area. Therefore, reasonable field management measures which can decrease the discharge of nitrogen and phosphorus of paddy fields and dry land are the key to agricultural non-point source pollution prevention and control.

  6. How does imperviousness develop and affect runoff generation in an urbanizing watershed?

    Directory of Open Access Journals (Sweden)

    Gerald Krebs

    2013-08-01

    Full Text Available Imperviousness associated with urbanization remains one of the biggest challenges in sustainable urban design. The replacement of forests, marshlands, buffers, and wetlands with impervious surfaces, strongly influences hydrological processes in urbanizing areas. This study analyzed the contribution of four constructed surfaces types – roofs, yards, roads, and an international airport – to surface runoff within a 21 km2 watershed, and presents the development over five decades (1977−2030. The land-cover model, used to assess watershed imperviousness in 2030, utilized coefficients between impervious areas generating surface runoff and the floor area, developed during the study. The conducted imperviousness analysis allowed the evaluation of land-use development impacts on the stream network, and the identification of hydrologically active areas for urban planning and stormwater management. Research revealed the importance of yard imperviousness related to suburban residential housing for stormwater runoff generation, and the impacts of transport-related imperviousness on stormwater runoff.

  7. LARGE-SCALE INDICATIVE MAPPING OF SOIL RUNOFF

    Directory of Open Access Journals (Sweden)

    E. Panidi

    2017-11-01

    Full Text Available In our study we estimate relationships between quantitative parameters of relief, soil runoff regime, and spatial distribution of radioactive pollutants in the soil. The study is conducted on the test arable area located in basin of the upper Oka River (Orel region, Russia. Previously we collected rich amount of soil samples, which make it possible to investigate redistribution of the Chernobyl-origin cesium-137 in soil material and as a consequence the soil runoff magnitude at sampling points. Currently we are describing and discussing the technique applied to large-scale mapping of the soil runoff. The technique is based upon the cesium-137 radioactivity measurement in the different relief structures. Key stages are the allocation of the places for soil sampling points (we used very high resolution space imagery as a supporting data; soil samples collection and analysis; calibration of the mathematical model (using the estimated background value of the cesium-137 radioactivity; and automated compilation of the map (predictive map of the studied territory (digital elevation model is used for this purpose, and cesium-137 radioactivity can be predicted using quantitative parameters of the relief. The maps can be used as a support data for precision agriculture and for recultivation or melioration purposes.

  8. Collaborative study for the validation of alternative in vitro potency assays for human tetanus immunoglobulins.

    Science.gov (United States)

    Gross, S; Janssen, S W J; de Vries, B; Terao, E; Daas, A; Buchheit, K-H

    2010-07-01

    An international collaborative study to validate 2 alternative in vitro methods for the potency testing of human tetanus immunoglobulin products was organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM). The study, run in the framework of the Biological Standardisation Programme (BSP) under the aegis of the European Commission and the Council of Europe, involved 21 official medicines control and industry laboratories from 15 countries. Both methods, an enzyme-linked immunoassay (EIA) and a toxoid inhibition assay (TIA), showed good reproducibility, repeatability and precision. EIA and TIA discriminated between low, medium and high potency samples. Potency estimates correlated well and both values were in close agreement with those obtained by in vivo methods. Moreover, these alternative methods allowed to resolve discrepant results between laboratories that were due to product potency loss and reporting errors. The study demonstrated that EIA and TIA are suitable quality control methods for tetanus immunoglobulin, which can be standardised in a control laboratory using a quality assurance system. Consequently, the Group of Experts on Human Blood and Blood Products of the European Pharmacopoeia revised the monograph on human tetanus immunoglobulins to include both the methods as compendial alternatives to the in vivo mouse challenge assay. 2010 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

  9. 77 FR 14801 - Request for Information (RFI) on Design of a Pilot Operational Study To Assess Alternative Blood...

    Science.gov (United States)

    2012-03-13

    ... permitted to donate under revised selection criteria. A study funded by the Food and Drug Administration... Operational Study To Assess Alternative Blood Donor Deferral Criteria for Men Who Have Had Sex With Other Men... (or studies) on alternative donor deferral criteria that would permit blood and plasma donations...

  10. Engineering study: disposition of terminal liquors for interim storage. [Eight alternative processes

    Energy Technology Data Exchange (ETDEWEB)

    Metz, W.P.; Ogren, W.E.

    1975-02-01

    Eight alternative processes were chosen as being technologically feasible within the time frame dictated by budgeting procedures and terminal liquor availability. Solidified waste products acceptable for single-shell tank storage were assumed to be placed in available single-shell tanks. Double-shell tanks were used only for the more mobile terminal liquors or semi-solid mush products. The mush, chemical neutralization, and clay in-tank processes offer potential savings of tens of millions of dollars over double-shell tank storage of terminal liquors. In order to achieve this cost savings, the process development and demonstration must be completed prior to the beginning of double-shell tank construction (Dec. 1976) expected to be funded from a fiscal year 1977 line item. Budgeting for these additional double-shell tanks must proceed since the processing options discussed here are not yet available and may not prove to be available at the required time. This study indicates the following topics for additional study: Process technology development to achieve interim storage of terminal liquor products receives the greatest emphasis as a means of reducing capital expenditures. Interim storage product criteria, waste inventory, and conversion to final form require definition to allow comparison of the alternatives for disposition of terminal liquors. The pseudotechnical nature of product acceptability criteria is important to the evaluation of the partial neutralization and aluminum removal alternatives. More accurate estimates of terminal liquor quantity and composition are required to give a sound technical basis for choosing the appropriate processing alternative. Retrieval and reprocessing operations may affect the comparisons presented by this study. (DLC)

  11. Substance use and dietary practices among students attending alternative high schools: results from a pilot study

    Directory of Open Access Journals (Sweden)

    Hannan Peter J

    2011-04-01

    Full Text Available Abstract Background Substance use and poor dietary practices are prevalent among adolescents. The purpose of this study was to examine frequency of substance use and associations between cigarette, alcohol and marijuana use and selected dietary practices, such as sugar-sweetened beverages, high-fat foods, fruits and vegetables, and frequency of fast food restaurant use among alternative high school students. Associations between multi-substance use and the same dietary practices were also examined. Methods A convenience sample of adolescents (n = 145; 61% minority, 52% male attending six alternative high schools in the St Paul/Minneapolis metropolitan area completed baseline surveys. Students were participants in the Team COOL (Controlling Overweight and Obesity for Life pilot study, a group randomized obesity prevention pilot trial. Mixed model multivariate analyses procedures were used to assess associations of interest. Results Daily cigarette smoking was reported by 36% of students. Cigarette smoking was positively associated with consumption of regular soda (p = 0.019, high-fat foods (p = 0.037, and fast food restaurant use (p = 0.002. Alcohol (p = 0.005 and marijuana use (p = 0.035 were positively associated with high-fat food intake. With increasing numbers of substances, a positive trend was observed in high-fat food intake (p = 0.0003. There were no significant associations between substance use and fruit and vegetable intake. Conclusions Alternative high school students who use individual substances as well as multiple substances may be at high risk of unhealthful dietary practices. Comprehensive health interventions in alternative high schools have the potential of reducing health-compromising behaviors that are prevalent among this group of students. This study adds to the limited research examining substance use and diet among at-risk youth. Trial registration number ClinicalTrials.gov: NCT01315743

  12. Runoff Analysis Considering Orographical Features Using Dual Polarization Radar Rainfall

    Science.gov (United States)

    Noh, Hui-seong; Shin, Hyun-seok; Kang, Na-rae; Lee, Choong-Ke; Kim, Hung-soo

    2013-04-01

    Recently, the necessity for rainfall estimation and forecasting using the radar is being highlighted, due to the frequent occurrence of torrential rainfall resulting from abnormal changes of weather. Radar rainfall data represents temporal and spatial distributions properly and replace the existing rain gauge networks. It is also frequently applied in many hydrologic field researches. However, the radar rainfall data has an accuracy limitation since it estimates rainfall, by monitoring clouds and precipitation particles formed around the surface of the earth(1.5-3km above the surface) or the atmosphere. In a condition like Korea where nearly 70% of the land is covered by mountainous areas, there are lots of restrictions to use rainfall radar, because of the occurrence of beam blocking areas by topography. This study is aiming at analyzing runoff and examining the applicability of (R(Z), R(ZDR) and R(KDP)) provided by the Han River Flood Control Office(HRFCO) based on the basin elevation of Nakdong river watershed. For this purpose, the amount of radar rainfall of each rainfall event was estimated according to three sub-basins of Nakdong river watershed with the average basin elevation above 400m which are Namgang dam, Andong dam and Hapcheon dam and also another three sub-basins with the average basin elevation below 150m which are Waegwan, Changryeong and Goryeong. After runoff analysis using a distribution model, Vflo model, the results were reviewed and compared with the observed runoff. This study estimated the rainfall by using the radar-rainfall transform formulas, (R(Z), R(Z,ZDR) and R(Z,ZDR,KDP) for four stormwater events and compared the results with the point rainfall of the rain gauge. As the result, it was overestimated or underestimated, depending on rainfall events. Also, calculation indicates that the values from R(Z,ZDR) and R(Z,ZDR,KDP) relatively showed the most similar results. Moreover the runoff analysis using the estimated radar rainfall is

  13. Advanced transportation system studies technical area 3: Alternate propulsion subsystem concepts, volume 2

    Science.gov (United States)

    Levak, Daniel

    1993-01-01

    The Alternate Propulsion Subsystem Concepts contract had five tasks defined for the first year. The tasks were: F-1A Restart Study, J-2S Restart Study, Propulsion Database Development, Space Shuttle Main Engine (SSME) Upper Stage Use, and CER's for Liquid Propellant Rocket Engines. The detailed study results, with the data to support the conclusions from various analyses, are being reported as a series of five separate Final Task Reports. Consequently, this volume only reports the required programmatic information concerning Computer Aided Design Documentation, and New Technology Reports. A detailed Executive Summary, covering all the tasks, is also available as Volume 1.

  14. Modeling relationship between runoff and soil properties in dry-farming lands, NW Iran

    OpenAIRE

    Vaezi, A. R.; Bahrami, H. A.; Sadeghi, S. H. R.; Mahdian, M. H.

    2010-01-01

    The process of transformation of rainfall into runoff over a catchment is very complex and exhibits both temporal and spatial variability. However, in a semi-arid area this variability is mainly controlled by the physical and chemical properties of the soil surface. Developing an accurate and easily-used model that can appropriately determine the runoff generation value is of strong demand. In this study a simple, an empirically based model developed to explore effect of soil properties on ru...

  15. Seasonality of runoff and precipitation regimes along transects in Peru and Austria

    OpenAIRE

    Gaudry Maria M. Cárdenas; Gutknecht Dieter; Parajka Juraj; Perdigão Rui A.P.; Blöschl Günter

    2017-01-01

    The aim of this study is to understand the seasonalities of runoff and precipitation and their controls along two transects in Peru and one transect in Austria. The analysis is based on daily precipitation data at 111 and 61 stations in Peru and Austria, respectively, and daily discharge data at 51 and 110 stations. The maximum Pardé coefficient is used to quantify the strength of the seasonalities of monthly precipitation and runoff. Circular statistics are used to quantify the seasonalities...

  16. A Global Assessment of Runoff Sensitivity to Changes in Precipitation, Potential Evaporation, and Other Factors

    OpenAIRE

    Berghuijs, Wouter; Larsen, Joshua; van Emmerik, Tim; Woods, Ross

    2017-01-01

    Precipitation (P) and potential evaporation (Ep) are commonly studied drivers of changing freshwater availability, as aridity (Ep/P) explains ∼90% of the spatial differences in mean runoff across the globe. However, it is unclear if changes in aridity over time are also the most important cause for temporal changes in mean runoff and how this degree of importance varies regionally. We show that previous global assessments that address these questions do not properly account for changes due to...

  17. The Effect of Rainfall Intensity on Soil Erosion and Runoff for Latosol Soil in Indonesia

    OpenAIRE

    Sukartaatmadja, Sukandi; Sato, Yohei; Yamaji, Eiji; Ishikawa, Masaya

    2003-01-01

    Soil erosion is the most serious problem of land degradation in Indonesia. However, limited report has been documented. The erosion problem in Indonesia, particularly in Java, has been at an alarming rate. The fundamental 1 case of soil erosion is the rain effect upon the soil. Rainfall intensity and soil characteristics are related to soil erosion and runoff The objective of this research was to study the relationship of rainfall intensity, soil erosion and runoff in latosol s...

  18. Rainfall timing and runoff: The influence of the criterion for rain event separation

    OpenAIRE

    Molina-Sanchis, Isabel; Lázaro, Roberto; Arnau-Rosalén, Eva; Calvo-Cases, Adolfo

    2016-01-01

    Rain is not uniform in time and space in semiarid areas and its distribution is very important for the runoff process. Hydrological studies usually divide rainfall into events. However, defining rain events is complicated, and rain characteristics vary depending on how the events are delimited. Choosing a minimum inter-event time (MIT) is a commonly used criterion. Our hypothesis is that there will be an optimal MIT that explains the maximum part of the variance of the runoff, with time to ru...

  19. Consequences of future increased Arctic runoff on Arctic Ocean stratification, circulation, and sea ice cover

    OpenAIRE

    Nummelin, Aleksi; Ilicak, Mehmet; Li, Camille; Smedsrud, Lars Henrik

    2016-01-01

    The Arctic Ocean has important freshwater sources including river runoff, low evaporation, and exchange with the Pacific Ocean. In the future, we expect even larger freshwater input as the global hydrological cycle accelerates, increasing high-latitude precipitation, and river runoff. Previous modeling studies show some robust responses to high-latitude freshwater perturbations, including a strengthening of Arctic stratification and a weakening of the large-scale ocean circulation...

  20. A comparison between wavelet based static and dynamic neural network approaches for runoff prediction

    Science.gov (United States)

    Shoaib, Muhammad; Shamseldin, Asaad Y.; Melville, Bruce W.; Khan, Mudasser Muneer

    2016-04-01

    In order to predict runoff accurately from a rainfall event, the multilayer perceptron type of neural network models are commonly used in hydrology. Furthermore, the wavelet coupled multilayer perceptron neural network (MLPNN) models has also been found superior relative to the simple neural network models which are not coupled with wavelet. However, the MLPNN models are considered as static and memory less networks and lack the ability to examine the temporal dimension of data. Recurrent neural network models, on the other hand, have the ability to learn from the preceding conditions of the system and hence considered as dynamic models. This study for the first time explores the potential of wavelet coupled time lagged recurrent neural network (TLRNN) models for runoff prediction using rainfall data. The Discrete Wavelet Transformation (DWT) is employed in this study to decompose the input rainfall data using six of the most commonly used wavelet functions. The performance of the simple and the wavelet coupled static MLPNN models is compared with their counterpart dynamic TLRNN models. The study found that the dynamic wavelet coupled TLRNN models can be considered as alternative to the static wavelet MLPNN models. The study also investigated the effect of memory depth on the performance of static and dynamic neural network models. The memory depth refers to how much past information (lagged data) is required as it is not known a priori. The db8 wavelet function is found to yield the best results with the static MLPNN models and with the TLRNN models having small memory depths. The performance of the wavelet coupled TLRNN models with large memory depths is found insensitive to the selection of the wavelet function as all wavelet functions have similar performance.

  1. Complementary and Alternative Medicine in the Pediatrics with Leukemia: A Narrative Review Study

    Directory of Open Access Journals (Sweden)

    Mojtaba Miladinia

    2017-01-01

    Full Text Available BackgroundFor using of complementary and alternative medicine methods (CAM in the leukemia pediatrics than other types of cancer, we have two great challenges; first challenge is their safety and risks and second challenge is study gaps in this field. Regarding to these challenges, this study is a narrative review of some CAM methods in the leukemia pediatrics from the perspective of their safety, risks and study gaps.Materials and MethodsIn this narrative review study searched both international electronic databases including ISI Web of science, PubMed, PsycINFO, CINAHL, ISC, Embase, Scopus, Google Scholar and also, Iranian electronic databases including Magiran, Medlib and SID. Also, searches were performed separately in the specialized journals in the field of leukemia pediatrics and complementary and alternative medicine research.ResultsMusic therapy, gentle yoga movements, gentle massage types are quite safe for leukemia pediatrics. But, use of heavy yoga movements, massages with deep pressure, acupressure and acupuncture can be dangerous for leukemia pediatrics (risks of bleeding and or infection. Also, this study showed that, the number of investigations about the use of CAM in the leukemia pediatrics is very limited; especially in the field of yoga and acupuncture.ConclusionThe results of this study can be a basis both for chose of safe CAM method in these children and a basis for future studies on the basis of identified study gaps in this review study.

  2. Theoretical study of OCCHCN as a potential alternative insulation gas for SF6

    Directory of Open Access Journals (Sweden)

    Zhiguo Chen

    2017-01-01

    Full Text Available Cyanoketene (OCCHCN has been reported as a potential alternative insulation gas for SF6 in Patent US0135817. Stationary point equilibrium geometries on the ground state have been optimized at the B3LYP/6-311+G(d,p level, and the harmonic vibration frequencies are calculated at the same level. The HOMO-LUMO energy gaps (Eg, ionization potentials (IP, and electron affinities (EA of the studied molecules are obtained. The minimum energy path (MEP is obtained by the intrinsic reaction coordinate (IRC theory, and the energetic information is further refined by QCISD(T (single-point method. The results show that OCCHCN can be used as SF6 alternative insulation gas in high voltage equipment according to potential energy surface analysis. As the isomerization and the cleavage reactions potential barriers are lower than the Eg and IP values, resulting in OCCHCN is not easy to be ionized and excited.

  3. Full-scale experimentations on alternative materials in roads: analysis of study practices.

    Science.gov (United States)

    François, D; Jullien, A; Kerzreho, J P; Chateau, L

    2009-03-01

    In France beginning in the 1990s, the topic of road construction using various alternative materials has given rise to several studies aimed at clarifying the technical and environmental feasibility of such an option. Although crucial to understanding and forecasting their behaviour in the field, an analysis of feedback from onsite experiences (back analysis) of roads built with alternative materials has not yet been carried out. The aim of the CAREX project (2003-2005) has been to fill this gap at the national scale. Based on a stress-response approach applied to both the alternative material and the road structure and including the description of external factors, a dedicated standardised framework for field data classification and analysis was adopted. To carry out this analysis, a set of 17 documented field experiments was identified through a specific national survey. It appears that a great heterogeneity exists in data processing procedures among studies. The description of material is acceptable while it is generally poor regarding external factors and structure responses. Structure monitoring is usually brief and mechanical loads too weak, which limits the significance of field testing. For future full-scale experiments, strengthening the realism within the testing conditions would be appropriate.

  4. Value engineering study report on Lower East Fork Poplar Creek Project. Alternative No. 3

    International Nuclear Information System (INIS)

    1995-08-01

    The project under study is Alternative No. 3 as identified in the Feasibility Study dated August 1994. This alternative is identified as Excavation and Disposal of Commercial/DOE, Other, and Residential Remedial Unit Soil. The assumptions used for generating baseline costs are discussed in site associated costs. It is further described as follows: Soils with mercury concentrations greater than 200 ppM in the Commercial/DOE and Other Remedial Units and greater than 180 ppM in the Residential Remedial Unit [41,300m 3 (54,000yd 3 a volume equivalent to approximately 6,750 dump truck loads)] would be excavated and disposed of in an approved, lined landfill at Y-12 with leachate collection and possible pretreatment of the leachate before discharge. Because 0.6 ha (1.5 acres) of wetland would be destroyed, wetlands banking would occur, whereby a 1.8-ha (4.5-acre) wetland would be constructed on DOE-owned land near K-25. Borrow soil would be obtained from the Y-12 West End Borrow Area or from excess soil located at Y-12 landfills to fill the excavation. It is estimated that 7.3 ha (18.2 acres, and area about the size of 17 football fields) of habitat would be adversely affected. This alternative would use BMPs to minimize any adverse affects and to comply substantively with regulatory requirements

  5. Spatiotemporal variability of saturation excess surface runoff in flat fields due to interactions with meso- and microtopography

    NARCIS (Netherlands)

    Appels, W.M.; Noij, I.G.A.M.; Massop, H.T.L.

    2013-01-01

    Surface runoff is the fastest route from field to stream and the main transport route for sediment and adsorbed contaminants, and as such an important cause of surface water contamination in agricultural areas. The goals of the study were to explain differences in measured surface runoff volumes and

  6. Reopening abandoned forest roads in northern Idaho, USA: Quantification of runoff, sediment concentration, infiltration, and interrill erosion parameters

    Science.gov (United States)

    R. B. Foltz; N. S. Copeland; W. J. Elliot

    2009-01-01

    This study measured runoff and sediment concentration from the tire track and from the non-tire track to determine infiltration, interrill erodibility, and vegetative cover impacts of reopening an abandoned forest road. Runoff was lowest on the non-track portion of the abandoned road and highest on the reopened road. Sediment concentrations were significantly higher on...

  7. Multiannual runoff variability in the upper Danube region

    International Nuclear Information System (INIS)

    Pekarova, P.

    2009-05-01

    The development of mankind has depended on availability of water resources. Already the first agricultural civilizations noticed the temporal variability of water resources and oscillation of the multi-annual dry and wet periods. The presented thesis summarizes results of more than fifteen years research activities of the author in the field of long-term runoff prediction. Statistical analysis of the runoff oscillations depends on availability of long time series of data. Systematic measurements of discharge in modern era started relatively late. The longest time series are available in Europe, but they do not exceed 200 years. Such long series are exceptional and in most parts of the world only much shorter series exist. Since studies dealing with the natural runoff oscillation and NAO phenomenon recently absent in Slovakia, there is the one aim of the thesis to fill in the gap in the long-term runoff fluctuation analysis and long-term discharge prediction methods development. The thesis focuses on the natural runoff cyclicity identification. In stochastic models, the climate changes scenarios caused by atmosphere warming are not involved however the runoff tele-connection around the Earth is studied. Scientific objectives of the thesis: 1. To reconstruct the Danube daily discharge series at Bratislava (1876-1890) based upon the Bratislava gauge daily water level observations; 2. to analyze variability and long term trends of the selected discharge Danube series characteristics for its Bratislava gauge; 3. to propose and develop the combined periodogram method for more exact spectral density identification in discharge time series; to analyze trends and periodicity in discharge long term series; to identify occurrence of the wet and dry periods over the world, to identify the influence of the NAO/AO/ENSO/QBO phenomena and the Sun activity on the runoff variability. 4. to present some long term stochastic prediction methods; to use two of them, the classical

  8. Comparison of planted soil infiltration systems for treatment of log yard runoff.

    Science.gov (United States)

    Hedmark, Asa; Scholz, Miklas; Aronsson, Par; Elowson, Torbjorn

    2010-07-01

    Treatment of log yard runoff is required to avoid contamination of receiving watercourses. The research aim was to assess if infiltration of log yard runoff through planted soil systems is successful and if different plant species affect the treatment performance at a field-scale experimental site in Sweden (2005 to 2007). Contaminated runoff from the log yard of a sawmill was infiltrated through soil planted with Alnus glutinosa (L.) Gärtner (common alder), Salix schwerinii X viminalis (willow variety "Gudrun"), Lolium perenne (L.) (rye grass), and Phalaris arundinacea (L.) (reed canary grass). The study concluded that there were no treatment differences when comparing the four different plants with each other, and there also were no differences between the tree and the grass species. Furthermore, the infiltration treatment was effective in reducing total organic carbon (55%) and total phosphorus (45%) concentrations in the runoff, even when the loads on the infiltration system increased from year to year.

  9. [Effect of antecedent dry period on water quality of urban storm runoff pollution].

    Science.gov (United States)

    Bian, Bo

    2009-12-01

    Identified the main factor influencing urban rainfall-runoff pollution provides a scientific basis for urban rainfall-runoff pollution control and management. Therefore, starting in May 2006, a study was conducted to characterize water quality from representative land uses types in Zhenjiang to analyse the effect of antecedent dry period on stormwater runoff quality. The results show that the beginning of rainfall, with the increase of antecedent dry periods, the percentages of less than 40 microm is increased, the correlation of the water quality parameters (TN, TP, Zn, Pb, Cu, TSS and COD) and antecedent dry period shows a significant positive correlation, dissolved pollutants in the initial period surface runoff is increased. These findings show that facilitating the recognition of antecedent dry periods is the main factor influencing the change in concentration and partitioning of pollutants to provide the scientific basis for non-point source pollution control and management.

  10. Enrichment behavior and transport mechanism of soil-bound PAHs during rainfall-runoff events.

    Science.gov (United States)

    Zheng, Yi; Luo, Xiaolin; Zhang, Wei; Wu, Bin; Han, Feng; Lin, Zhongrong; Wang, Xuejun

    2012-12-01

    Polycyclic Aromatic Hydrocarbons (PAHs) transported by surface runoff result in nonpoint source pollution and jeopardize aquatic ecosystems. The transport mechanism of PAHs during rainfall-runoff events has been rarely studied regarding pervious areas. An experimental system was setup to simulate the runoff pollution process on PAHs-contaminated soil. The enrichment behavior of soil-bound PAHs was investigated. The results show that soil organic matters (SOM), rather than clay particles, seem to be the main carrier of PAHs. The enrichment is highly conditioned on runoff and erosion processes, and its magnitude varies among PAH compounds. It is not feasible to build a simple and universal relationship between enrichment ratio and sediment discharge following the traditional enrichment theory. To estimate the flux of PAHs from pervious areas, soil erosion process has to be clearly understood, and both organic carbon content and composition of SOM should be factored into the calculation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Source diagnostics of polycyclic aromatic hydrocarbons in urban road runoff, dust, rain and canopy throughfall.

    Science.gov (United States)

    Zhang, Wei; Zhang, Shucai; Wan, Chao; Yue, Dapan; Ye, Youbin; Wang, Xuejun

    2008-06-01

    Diagnostic ratios and multivariate analysis were utilized to apportion polycyclic aromatic hydrocarbon (PAH) sources for road runoff, road dust, rain and canopy throughfall based on samples collected in an urban area of Beijing, China. Three sampling sites representing vehicle lane, bicycle lane and branch road were selected. For road runoff and road dust, vehicular emission and coal combustion were identified as major sources, and the source contributions varied among the sampling sites. For rain, three principal components were apportioned representing coal/oil combustion (54%), vehicular emission (34%) and coking (12%). For canopy throughfall, vehicular emission (56%), coal combustion (30%) and oil combustion (14%) were identified as major sources. Overall, the PAH's source for road runoff mainly reflected that for road dust. Despite site-specific sources, the findings at the study area provided a general picture of PAHs sources for the road runoff system in urban area of Beijing.

  12. Statistical determination of rainfall-runoff erosivity indices for single storms in the Chinese Loess Plateau.

    Directory of Open Access Journals (Sweden)

    Mingguo Zheng

    Full Text Available Correlation analysis is popular in erosion- or earth-related studies, however, few studies compare correlations on a basis of statistical testing, which should be conducted to determine the statistical significance of the observed sample difference. This study aims to statistically determine the erosivity index of single storms, which requires comparison of a large number of dependent correlations between rainfall-runoff factors and soil loss, in the Chinese Loess Plateau. Data observed at four gauging stations and five runoff experimental plots were presented. Based on the Meng's tests, which is widely used for comparing correlations between a dependent variable and a set of independent variables, two methods were proposed. The first method removes factors that are poorly correlated with soil loss from consideration in a stepwise way, while the second method performs pairwise comparisons that are adjusted using the Bonferroni correction. Among 12 rainfall factors, I30 (the maximum 30-minute rainfall intensity has been suggested for use as the rainfall erosivity index, although I30 is equally correlated with soil loss as factors of I20, EI10 (the product of the rainfall kinetic energy, E, and I10, EI20 and EI30 are. Runoff depth (total runoff volume normalized to drainage area is more correlated with soil loss than all other examined rainfall-runoff factors, including I30, peak discharge and many combined factors. Moreover, sediment concentrations of major sediment-producing events are independent of all examined rainfall-runoff factors. As a result, introducing additional factors adds little to the prediction accuracy of the single factor of runoff depth. Hence, runoff depth should be the best erosivity index at scales from plots to watersheds. Our findings can facilitate predictions of soil erosion in the Loess Plateau. Our methods provide a valuable tool while determining the predictor among a number of variables in terms of correlations.

  13. Statistical Determination of Rainfall-Runoff Erosivity Indices for Single Storms in the Chinese Loess Plateau

    Science.gov (United States)

    Zheng, Mingguo; Chen, Xiaoan

    2015-01-01

    Correlation analysis is popular in erosion- or earth-related studies, however, few studies compare correlations on a basis of statistical testing, which should be conducted to determine the statistical significance of the observed sample difference. This study aims to statistically determine the erosivity index of single storms, which requires comparison of a large number of dependent correlations between rainfall-runoff factors and soil loss, in the Chinese Loess Plateau. Data observed at four gauging stations and five runoff experimental plots were presented. Based on the Meng’s tests, which is widely used for comparing correlations between a dependent variable and a set of independent variables, two methods were proposed. The first method removes factors that are poorly correlated with soil loss from consideration in a stepwise way, while the second method performs pairwise comparisons that are adjusted using the Bonferroni correction. Among 12 rainfall factors, I 30 (the maximum 30-minute rainfall intensity) has been suggested for use as the rainfall erosivity index, although I 30 is equally correlated with soil loss as factors of I 20, EI 10 (the product of the rainfall kinetic energy, E, and I 10), EI 20 and EI 30 are. Runoff depth (total runoff volume normalized to drainage area) is more correlated with soil loss than all other examined rainfall-runoff factors, including I 30, peak discharge and many combined factors. Moreover, sediment concentrations of major sediment-producing events are independent of all examined rainfall-runoff factors. As a result, introducing additional factors adds little to the prediction accuracy of the single factor of runoff depth. Hence, runoff depth should be the best erosivity index at scales from plots to watersheds. Our findings can facilitate predictions of soil erosion in the Loess Plateau. Our methods provide a valuable tool while determining the predictor among a number of variables in terms of correlations. PMID

  14. Source tracing of natural organic matter bound mercury in boreal forest runoff with mercury stable isotopes.

    Science.gov (United States)

    Jiskra, Martin; Wiederhold, Jan G; Skyllberg, Ulf; Kronberg, Rose-Marie; Kretzschmar, Ruben

    2017-10-18

    Terrestrial runoff represents a major source of mercury (Hg) to aquatic ecosystems. In boreal forest catchments, such as the one in northern Sweden studied here, mercury bound to natural organic matter (NOM) represents a large fraction of mercury in the runoff. We present a method to measure Hg stable isotope signatures of colloidal Hg, mainly complexed by high molecular weight or colloidal natural organic matter (NOM) in natural waters based on pre-enrichment by ultrafiltration, followed by freeze-drying and combustion. We report that Hg associated with high molecular weight NOM in the boreal forest runoff has very similar Hg isotope signatures as compared to the organic soil horizons of the catchment area. The mass-independent fractionation (MIF) signatures (Δ 199 Hg and Δ 200 Hg) measured in soils and runoff were in agreement with typical values reported for atmospheric gaseous elemental mercury (Hg 0 ) and distinctly different from reported Hg isotope signatures in precipitation. We therefore suggest that most Hg in the boreal terrestrial ecosystem originated from the deposition of Hg 0 through foliar uptake rather than precipitation. Using a mixing model we calculated the contribution of soil horizons to the Hg in the runoff. At moderate to high flow runoff conditions, that prevailed during sampling, the uppermost part of the organic horizon (Oe/He) contributed 50-70% of the Hg in the runoff, while the underlying more humified organic Oa/Ha and the mineral soil horizons displayed a lower mobility of Hg. The good agreement of the Hg isotope results with other source tracing approaches using radiocarbon signatures and Hg : C ratios provides additional support for the strong coupling between Hg and NOM. The exploratory results from this study illustrate the potential of Hg stable isotopes to trace the source of Hg from atmospheric deposition through the terrestrial ecosystem to soil runoff, and provide a basis for more in-depth studies investigating the

  15. Snowmelt runoff from northern alpine tundra hillslopes: major processes and methods of simulation

    Directory of Open Access Journals (Sweden)

    W. L. Quinton

    2004-01-01

    Full Text Available In northern alpine tundra, large slope gradients, late-lying snow drifts and shallow soils overlying impermeable substrates all contribute to large hillslope runoff volumes during the spring freshet. Understanding the processes and pathways of hillslope runoff in this environment is, therefore, critical to understanding the water cycle within northern alpine tundra ecosystems. This study: (a presents the results of a field study on runoff from a sub-alpine tundra hillslope with a large snow drift during the spring melt period; (b identifies the major runoff processes that must be represented in simulations of snowmelt runoff from sub-alpine tundra hillslopes; (c describes how these processes can be represented in a numerical simulation model; and d compares field measurements with modelled output to validate or refute the conceptual understanding of runoff generation embodied in the process simulations. The study was conducted at Granger Creek catchment, 15 km south of Whitehorse, Yukon Territory, Canada, on a north-facing slope below a late-lying snow drift. For the freshet period, the major processes to be represented in a runoff model include the rate of meltwater release from the late-lying snowdrift, the elevation and thickness of the saturated layer, the magnitude of the soil permeability and its variation with depth. The daily cycle of net all-wave radiation was observed to drive the diurnal pulses of melt water from the drift; this, in turn, was found to control the daily pulses of flow through the hillslope subsurface and in the stream channel. The computed rate of frost table lowering fell within the observed values; however, there was wide variation among the measured frost table depths. Spatial variability in frost table depth would result in spatial variabilities in saturated layer depth and thickness, which would, in turn, produce variations in subsurface flow rates over the slope, including preferential flowpaths. Keywords

  16. Urban runoff forecasting with ensemble weather predictions

    DEFF Research Database (Denmark)

    Pedersen, Jonas Wied; Courdent, Vianney Augustin Thomas; Vezzaro, Luca

    This research shows how ensemble weather forecasts can be used to generate urban runoff forecasts up to 53 hours into the future. The results highlight systematic differences between ensemble members that needs to be accounted for when these forecasts are used in practice.......This research shows how ensemble weather forecasts can be used to generate urban runoff forecasts up to 53 hours into the future. The results highlight systematic differences between ensemble members that needs to be accounted for when these forecasts are used in practice....

  17. Runoff and Sediment Response to Cascade Hydropower Exploitation in the Middle and Lower Han River, China

    Directory of Open Access Journals (Sweden)

    Junhong Zhang

    2017-01-01

    Full Text Available With the rapid development of hydropower exploitation in China, changes in runoff and sediment transport have become a significant issue that cannot be neglected. In this study, the Han River was selected as a study case, where the runoff variation and changes in sediment load at the Baihe, Huangjiagang, Huangzhuang, and Xiantao stations were analyzed in different time periods. The results indicate that impact of cascade hydropower exploitation on runoff and sediment transport is significantly different even during the same time periods. After reservoir regulation, the decreasing of sediment load is faster than that of runoff. Strong positive correlation between runoff and sediment load exists during different time periods, while reservoir operation leads to different turning points at the Baihe, Huangjiagang, Huangzhuang, and Xiantao stations in the middle and lower Han River. As a key driving factor, runoff variation contributed to sediment transport with different impact index CR. The impact index CR before and after the first change point at the Baihe, Huangjiagang, Huangzhuang, and Xiantao stations is 43.35%, −3.68%, 11.17%, and 30.12%, respectively. This study helps us understand and evaluate the hydrological changes under cascade hydropower exploitation in the middle and lower Han River.

  18. Responses of hydrochemical inorganic ions in the rainfall-runoff processes of the experimental catchments and its significance for tracing

    Science.gov (United States)

    Gu, W.-Z.; Lu, J.-J.; Zhao, X.; Peters, N.E.

    2007-01-01

    Aimed at the rainfall-runoff tracing using inorganic ions, the experimental study is conducted in the Chuzhou Hydrology Laboratory with special designed experimental catchments, lysimeters, etc. The various runoff components including the surface runoff, interflow from the unsaturated zone and the groundwater flow from saturated zone were monitored hydrometrically. Hydrochemical inorganic ions including Na+, K+, Ca2+, Mg2+, Cl-, SO42-, HCO3- + CO32-, NO3-, F-, NH4-, PO42-, SiO2 and, pH, EC, 18O were measured within a one month period for all processes of rainfall, various runoff components and groundwater within the catchment from 17 boreholes distributed in the Hydrohill Catchment, few soil water samples were also included. The results show that: (a) all the runoff components are distinctly identifiable from both the relationships of Ca2+ versus Cl-/SO42-, EC versus Na+/(Na+ + Ca2+) and, from most inorganic ions individually; (b) the variation of inorganic ions in surface runoff is the biggest than that in other flow components; (c) most ions has its lowermost concentration in rainfall process but it increases as the generation depths of runoff components increased; (d) quantitatively, ion processes of rainfall and groundwater flow display as two end members of that of other runoff components; and (e) the 18O processes of rainfall and runoff components show some correlation with that of inorganic ions. The results also show that the rainfall input is not always the main source of inorganic ions of various runoff outputs due to the process of infiltration and dissolution resulted from the pre-event processes. The amount and sources of Cl- of runoff components with various generation mechanisms challenge the current method of groundwater recharge estimation using Cl-.

  19. Prediction of hydrographs and flow-duration curves in almost ungauged catchments: Which runoff measurements are most informative for model calibration?

    Science.gov (United States)

    Pool, Sandra; Viviroli, Daniel; Seibert, Jan

    2017-11-01

    Applications of runoff models usually rely on long and continuous runoff time series for model calibration. However, many catchments around the world are ungauged and estimating runoff for these catchments is challenging. One approach is to perform a few runoff measurements in a previously fully ungauged catchment and to constrain a runoff model by these measurements. In this study we investigated the value of such individual runoff measurements when taken at strategic points in time for applying a bucket-type runoff model (HBV) in ungauged catchments. Based on the assumption that a limited number of runoff measurements can be taken, we sought the optimal sampling strategy (i.e. when to measure the streamflow) to obtain the most informative data for constraining the runoff model. We used twenty gauged catchments across the eastern US, made the assumption that these catchments were ungauged, and applied different runoff sampling strategies. All tested strategies consisted of twelve runoff measurements within one year and ranged from simply using monthly flow maxima to a more complex selection of observation times. In each case the twelve runoff measurements were used to select 100 best parameter sets using a Monte Carlo calibration approach. Runoff simulations using these 'informed' parameter sets were then evaluated for an independent validation period in terms of the Nash-Sutcliffe efficiency of the hydrograph and the mean absolute relative error of the flow-duration curve. Model performance measures were normalized by relating them to an upper and a lower benchmark representing a well-informed and an uninformed model calibration. The hydrographs were best simulated with strategies including high runoff magnitudes as opposed to the flow-duration curves that were generally better estimated with strategies that captured low and mean flows. The choice of a sampling strategy covering the full range of runoff magnitudes enabled hydrograph and flow-duration curve

  20. Trend and concentrations of legacy lead (Pb) in highway runoff.

    Science.gov (United States)

    Kayhanian, Masoud

    2012-01-01

    This study presents the results of lead (Pb) concentrations from both highway runoff and contaminated soil along 32 and 23 highway sites, respectively. In general, the Pb concentration on topsoil (0-15 cm) along highways was much higher than the Pb concentration in subsurface soil (15-60 cm). The Pb deposited on soil appears to be anthropogenic and a strong correlation was found between the Pb concentration in surface soil and highway runoff in urban areas. The concentration of Pb measured during 1980s from highways runoff throughout the world was up to 11 times higher than the measured values in mid 1990 s and 2000s. The current Pb deposited on soil near highways appears to be a mixture of paint, tire weight balance and old leaded gasoline combustion. Overall, the Pb phase-out regulation reduced the Pb deposits in the environment and consequently lowered Pb loading into receiving waters. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Performance of Two Bioswales on Urban Runoff Management

    Directory of Open Access Journals (Sweden)

    Qingfu Xiao

    2017-09-01

    Full Text Available This study evaluated the effectiveness of two bioswales eight years after construction in Davis, California. The treatment bioswale measured 9 m × 1 m × 1 m (L × W × D. Engineered soil mix (75% native lava rock and 25% loam soil replaced the native loam soil. Four Red Tip Photinia (Photinia × fraseri Dress trees and two Blueberry Muffin Hawthorn (Rhaphiolepis umbellata (Thunb. Makino shrubs were planted in the bioswale. Runoff flowed into the bioswale from an adjacent 171 m2 panel of turf grass. An identically sized control bioswale consisting of non-disturbed native soil was located adjacent to the treatment bioswale. Surface runoff quantity and quality were measured during three experiments with different pollutant loads. When compared to the control, the treatment bioswale reduced surface runoff by 99.4%, and reduced nitrogen, phosphate, and total organic carbon loading by 99.1%, 99.5%, and 99.4%, respectively. After eight years, tree growth characteristics were similar across both sites.

  2. Global drivers effect in multi-annual variability of runoff

    Directory of Open Access Journals (Sweden)

    Fendeková Miriam

    2014-09-01

    Full Text Available Changes in runoff parameters are very important for Slovakia, where stream-flow discharges, being supplied by precipitation and groundwater runoff, are preferentially influenced by climatic conditions. Therefore, teleconnections between runoff parameters, climate parameters and global atmospheric drivers such as North Atlantic Oscillation, Southern Pacific Oscillation, Quasi-biennial oscillation and solar activity were studied in the Nitra River Basin, Slovakia. Research was mostly based on records of 80 years (1931-2010 for discharges and baseflow, and 34 years for groundwater heads. Methods of autocorrelation, spectral analysis, cross-correlation and coherence function were used. Results of auto- correllograms for discharges, groundwater heads and base flow values showed a very distinct 11-year and 21-year periodicity. Spectrogram analysis documented the 11-year, 7.8-year, 3.6-year and 2.4-year periods in the discharge, precipitation and air temperature time series. The same cycles except of 11-years were also identified in the long-term series of the North Atlantic Oscillation and Southern Pacific Oscillation indices. The cycle from approximately 2.3 to 2.4-years is most likely connected with Quasi-biennial oscillation. The close negative correlation between the North Atlantic Oscillation winter index and the hydrological surface and groundwater parameters can be used for their prediction within the same year and also for one year in advance.

  3. Decrease of non-point zinc runoff using porous concrete.

    Science.gov (United States)

    Harada, Shigeki; Komuro, Yoshinori

    2010-01-01

    The use of porous concrete columns to decrease the amount of zinc in stormwater runoff is examined. The concentration of zinc in a simulated stormwater fluid (zinc acetate solution), fed through concrete columns (slashed circle10x10cm) decreased by 50-81%, suggesting physical adsorption of zinc by the porous concrete. We propose the use of porous concrete columns (slashed circle50x10cm) as the base of sewage traps. Longer-term, high-zinc concentration monitoring revealed that porous concrete blocks adsorb 38.6mgcm(-3) of zinc. A period of no significant zinc runoff (with an acceptable concentration of zinc in runoff of 0.03mgL(-1), a zinc concentration equal to the Japanese Environmental Standard) is estimated for 41years using a 1-ha catchment area with 20 porous concrete sewage traps. Scanning electron microscopy of the porous concrete used in this study indicates that the needle-like particles formed by hydration action significantly increase zinc adsorption. Evidence suggests that the hydrant is ettringite and has an important role in zinc adsorption, the resulting immobilization of zinc and the subsequent effects on groundwater quality. Copyright 2009 Elsevier Ltd. All rights reserved.

  4. Napropamide residues in runoff and infiltration water from pepper production.

    Science.gov (United States)

    Antonious, George F; Patterson, Matthew A

    2005-01-01

    A field study was conducted on a Lowell silty loam soil of 2.7% organic matter at the Kentucky State University Research Farm, Franklin County, Kentucky. Eighteen universal soil loss equation (USLE) standard plots (22 x 3.7 m each) were established on a 10% slope. Three soil management practices were used: (i) class-A biosolids (sewage sludge), (ii) yard waste compost, each mixed with native soil at a rate of 50 ton acre(-1) on a dry-weight basis, and (iii) a no-mulch (NM) treatment (rototilled bare soil), used for comparison purposes. Devrinol 50-DF "napropamide" [N,N-diethyl-2-(1-naphthyloxy) propionamide] was applied as a preemergent herbicide, incorporated into the soil surface, and the plots were planted with 60-day-old sweet bell pepper seedlings. Napropamide residues one hour following spraying averaged 0.8, 0.4, and 0.3 microg g(-1) dry soil in sewage sludge, yard waste compost, and no-mulch treatments, respectively. Surface runoff water, runoff sediment, and napropamide residues in runoff were significantly reduced by the compost and biosolid treatments. Yard waste compost treatments increased water infiltration and napropamide residues in the vadose zone compared to sewage sludge and NM treatments. Total pepper yields from yard waste compost amended soils (9187 lbs acre(-1)) was significantly higher (P soil amended with class-A biosolids (6984 lbs acre(-1)) or the no-mulch soil (7162 lbs acre(-1)).

  5. Barium as a potential indicator of phosphorus in agricultural runoff.

    Science.gov (United States)

    Ahlgren, Joakim; Djodjic, Faruk; Wallin, Mats

    2012-01-01

    In many catchments, anthropogenic input of contaminants, and in particular phosphorus (P), into surface water is a mixture of agricultural and sewage runoff. Knowledge about the relative contribution from each of these sources is vital for mitigation of major environmental problems such as eutrophication. In this study, we investigated whether the distribution of trace elements in surface waters can be used to trace the contamination source. Water from three groups of streams was investigated: streams influenced only by agricultural runoff, streams influenced mainly by sewage runoff, and reference streams. Samples were collected at different flow regimes and times of year and analyzed for 62 elements using ICP-MS. Our results show that there are significant differences between the anthropogenic sources affecting the streams in terms of total element composition and individual elements, indicating that the method has the potential to trace anthropogenic impact on surface waters. The elements that show significant differences between sources are strontium (p barium (p barium shows the greatest potential as a tracer for an individual source of anthropogenic input to surface waters. We observed a strong relationship between barium and total P in the investigated samples (R(2) = 0.78), which could potentially be used to apportion anthropogenic sources of P and thereby facilitate targeting of mitigation practices. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  6. Alternating ibuprofen and acetaminophen in the treatment of febrile children: a pilot study [ISRCTN30487061

    Directory of Open Access Journals (Sweden)

    Sabra Ramzi

    2006-03-01

    Full Text Available Abstract Background Alternating ibuprofen and acetaminophen for the treatment of febrile children is a prevalent practice among physicians and parents, despite the lack of evidence on effectiveness or safety. This randomized, double-blind and placebo-controlled clinical trial aims at comparing the antipyretic effectiveness and safety of a single administration of alternating ibuprofen and acetaminophen doses to that of ibuprofen mono-therapy in febrile children. Methods Seventy febrile children were randomly allocated to receive either a single oral dose of 10 mg/kg ibuprofen and 15 mg/kg oral acetaminophen after 4 hours, or a similar dose of ibuprofen and placebo at 4 hours. Rectal temperature was measured at baseline, 4, 5, 6, 7 and 8 hours later. Endpoints included proportions of afebrile children at 6, 7 and 8 hours, maximum decline in temperature, time to recurrence of fever, and change in temperature from baseline at each time point. Intent-to-treat analysis was planned with statistical significance set at P Results A higher proportion of subjects in the intervention group (83.3% became afebrile at 6 hours than in the control group (57.6%; P = 0.018. This difference was accentuated at 7 and 8 hours (P Conclusion A single dose of alternating ibuprofen and acetaminophen appears to be a superior antipyretic regimen than ibuprofen mono-therapy. Further studies are needed to confirm these findings.

  7. Coping behavior in multiple sclerosis-complementary and alternative medicine: A cross-sectional study.

    Science.gov (United States)

    Rommer, Paulus S; König, Nicolaus; Sühnel, Annett; Zettl, Uwe K

    2018-04-10

    Treatment options for multiple sclerosis (MS) have enlarged tremendously over the last years. Nonetheless, lots of patients look for alternative treatment options. The use of complementary and alternative medicine (CAM) is widespread in MS, however, its scientific investigation is limited so far. The aim of the study is to analyse clinical and demographical differences of MS patients in dependency of their CAM utilization as coping strategy. A total of 254 patients with a clinically definite MS were examined in a semistructured interview. Additional standardized questionnaires were used to measure different aspects of coping with illness. All patients underwent neurological examination. About 206 of all enrolled patients are CAM users (81.1%). They have a longer disease duration (8.3 years vs 7.3 years, P = 0.028) and show higher disability (median EDSS 4.0 vs 2.0, P alternative or complementary methods. CAM utilization may mirror unmet needs in the treatment of MS. © 2018 The Authors. CNS Neuroscience & Therapeutics Published by John Wiley & Sons Ltd.

  8. An Experimental Study of Surfactant Alternating CO2 Injection for Enhanced Oil Recovery of Carbonated Reservoir

    Directory of Open Access Journals (Sweden)

    Asghar Gandomkar

    2016-10-01

    Full Text Available Core flooding experiments were conducted with the objective of evaluating near miscible surfactant alternating CO2 injection and the effect of surfactant concentrations on gas-oil and water displacements in porous media. The core samples were provided from a low permeability mixed wet oil reservoir at 156 °F and 1900 psia. In addition, very few studies of surfactant adsorption on carbonate minerals have been conducted. Hence, the surfactant adsorption on carbonate rock was determined by core flooding and crushed tests. It was found that for the crushed rock, the required equilibrium time is approximately five hours, while it is more than four days for the flow-through tests. Hysteresis effects demonstrated that the irreducible water saturations were 5 to 10% higher than the initial connate water saturation after drainage cycles during 5000 ppm surfactant solution. Furthermore, near-miscible surfactant alternating CO2 injection process led to a 4-17% increase in the recovery factor in comparison to water alternating gas process.

  9. Theoretical and NMR conformational studies of β-proline oligopeptides with alternating chirality of pyrrolidine units

    Science.gov (United States)

    Mantsyzov, Alexey B.; Savelyev, Oleg Y.; Ivantcova, Polina M.; Bräse, Stefan; Kudryavtsev, Konstantin V.; Polshakov, Vladimir I.

    2018-03-01

    Synthetic β-peptides are potential functional mimetics of native α-proteins. A recently developed, novel, synthetic approach provides an effective route to the broad group of β-proline oligomers with alternating patterns of stereogenic centers. Conformation of the pyrrolidine ring, Z/E isomerism of β-peptide bonds, and hindered rotation of the neighboring monomers determine the spatial structure of this group of β-proline oligopeptides. Preferences in structural organization and corresponding thermodynamic properties are determined by NMR spectroscopy, restrained molecular dynamics and quantum mechanics. The studied β-proline oligopeptides exist in dimethyl sulfoxide solution in a limited number of conformers, with compatible energy of formation and different spatial organization. In the β-proline tetrapeptide with alternating chirality of composing pyrrolidine units, one of three peptide bonds may exist in an E configuration. For the alternating β-proline pentapeptide, the presence of an E configuration for at least of one β-peptide bond is mandatory. In this case, three peptide bonds synchronously change their configurations. Larger polypeptides may only exist in the presence of several E configurations of β-peptide bonds forming a wave-like extended structure.

  10. Theoretical and NMR Conformational Studies of β-Proline Oligopeptides With Alternating Chirality of Pyrrolidine Units

    Directory of Open Access Journals (Sweden)

    Alexey B. Mantsyzov

    2018-03-01

    Full Text Available Synthetic β-peptides are potential functional mimetics of native α-proteins. A recently developed, novel, synthetic approach provides an effective route to the broad group of β-proline oligomers with alternating patterns of stereogenic centers. Conformation of the pyrrolidine ring, Z/E isomerism of β-peptide bonds, and hindered rotation of the neighboring monomers determine the spatial structure of this group of β-proline oligopeptides. Preferences in their structural organization and corresponding thermodynamic properties are determined by NMR spectroscopy, restrained molecular dynamics and quantum mechanics. The studied β-proline oligopeptides exist in dimethyl sulfoxide solution in a limited number of conformers, with compatible energy of formation and different spatial organization. In the β-proline tetrapeptide with alternating chirality of composing pyrrolidine units, one of three peptide bonds may exist in an E configuration. For the alternating β-proline pentapeptide, the presence of an E configuration for at least of one β-peptide bond is mandatory. In this case, three peptide bonds synchronously change their configurations. Larger polypeptides may only exist in the presence of several E configurations of β-peptide bonds forming a wave-like extended structure.

  11. Comparison between snowmelt-runoff and rainfall-runoff nonpoint source pollution in a typical urban catchment in Beijing, China.

    Science.gov (United States)

    Chen, Lei; Zhi, Xiaosha; Shen, Zhenyao; Dai, Ying; Aini, Guzhanuer

    2018-01-01

    As a climate-driven event, nonpoint source (NPS) pollution is caused by rainfall- or snowmelt-runoff processes; however, few studies have compared the characteristics and mechanisms of these two kinds of NPS processes. In this study, three factors relating to urban NPS, including surface dust, snowmelt, and rainfall-runoff processes, were analyzed comprehensively by both field sampling and laboratory experiments. The seasonal variation and leaching characteristics of pollutants in surface dust were explored, and the runoff quality of snowmelt NPS and rainfall NPS were compared. The results indicated that dusts are the main sources of urban NPS and more pollutants are deposited in dust samples during winter and spring. However, pollutants in surface dust showed a low leaching ratio, which indicated most NPS pollutants would be carried as particulate forms. Compared to surface layer, underlying snow contained higher chemical oxygen demand, total suspended solids (TSS), Cu, Fe, Mn, and Pb concentrations, while the event mean concentration of most pollutants in snowmelt tended to be higher in roads. Moreover, the TSS and heavy metal content of snowmelt NPS was always higher than those of rainfall NPS, which indicated the importance of controlling snowmelt pollution for effective water quality management.

  12. Quantitative assessment of the impacts of climate change and human activities on runoff change in a typical karst watershed, SW China.

    Science.gov (United States)

    Wu, Luhua; Wang, Shijie; Bai, Xiaoyong; Luo, Weijun; Tian, Yichao; Zeng, Cheng; Luo, Guangjie; He, Shiyan

    2017-12-01

    The Yinjiang River watershed is a typical karst watershed in Southwest China. The present study explored runoff change and its responses to different driving factors in the Yinjiang River watershed over the period of 1984 to 2015. The methods of cumulative anomaly, continuous wavelet analysis, Mann-Kendall rank correlation trend test, and Hurst exponent were applied to analyze the impacts of climate change and human activities on runoff change. The contributions of climate change and human activities to runoff change were quantitatively assessed using the comparative method of the slope changing ratio of cumulative quantity (SCRCQ). The following results were obtained: (1) From 1984 to 2015, runoff and precipitation exhibited no-significant increasing trend, whereas evaporation exhibited significant decreasing trend. (2) In the future, runoff, precipitation, and evaporation will exhibit weak anti-persistent feature with different persistent times. This feature indicated that in their persistent times, runoff and precipitation will continuously decline, whereas evaporation will continuously increase. (3) Runoff and precipitation were well-synchronized with abrupt change features and stage characteristics, and exhibited consistent multi-timescale characteristics that were different from that of evaporation. (4) The contribution of precipitation to runoff change was 50%-60% and was considered high and stable. The contribution of evaporation to runoff change was 10%-90% and was variable with a positive or negative effects. The contribution of human activities to runoff change was 20%-60% and exerted a low positive or negative effect. (5) Climatic factors highly contributed to runoff change. By contrast, the contribution of human activities to runoff change was low. The contribution of climatic factors to runoff change was highly variable because of differences among base periods. In conclusion, this paper provides a basic theoretical understanding of the main factors

  13. Methodology for Analyzing and Predicting the Runoff and Sediment into a Reservoir

    Directory of Open Access Journals (Sweden)

    Chun-Feng Hao

    2017-06-01

    Full Text Available With the rapid economic growth in China, a large number of hydropower projects have been planned and constructed. The sediment deposition of the reservoirs is one of the most important disputes during the construction and operation, because there are many heavy sediment-laden rivers. The analysis and prediction of the runoff and sediment into a reservoir is of great significance for reservoir operation. With knowledge of the incoming runoff and sediment characteristics, the regulator can adjust the reservoir discharge to guarantee the water supply, and flush more sediment at appropriate times. In this study, the long-term characteristics of runoff and sediment, including trend, jump point, and change cycle, are analyzed using various statistical approaches, such as accumulated anomaly analysis, the Fisher ordered clustering method, and Maximum Entropy Spectral Analysis (MESA. Based on the characteristics, a prediction model is established using the Auto-Regressive Moving Average (ARIMA method. The whole analysis and prediction system is applied to The Three Gorges Project (TGP, one of the biggest hydropower-complex projects in the world. Taking hydrologic series from 1955 to 2010 as the research objectives, the results show that both the runoff and the sediment are decreasing, and the reduction rate of sediment is much higher. Runoff and sediment into the TGP display cyclic variations over time, with a cycle of about a decade, but catastrophe points for runoff and sediment appear in 1991 and 2001, respectively. Prediction models are thus built based on monthly average hydrologic series from 2003 to 2010. ARIMA (1, 1, 1 × (1, 1, 112 and ARIMA (0, 1, 1 × (0, 1, 112 are selected for the runoff and sediment predictions, respectively, and the parameters of the models are also calibrated. The analysis of autocorrelation coefficients and partial autocorrelation coefficients of the residuals indicates that the models built in this study are feasible

  14. Modelling the effect of fire frequency on runoff and erosion in north-central Portugal using the revised Morgan-Morgan-Finney

    Science.gov (United States)

    Hosseini, Mohammadreza; Nunes, João Pedro; González Pelayo, Oscar; Keizer, Jan Jacob; Ritsema, Coen; Geissen, Violette

    2017-04-01

    Models can be valuable for foreseeing the hydrological effects of fires and to plan and execute post-fire management alternatives. In this study, the revised Morgan-Morgan-Finney (MMF) model was utilized to simulate runoff and soil erosion in recently burned maritime pine plantations with different fire regimes, in a wet Mediterranean area of north-central Portugal. The MMF model was adjusted for burned zones in order to accommodate seasonal patterns in runoff and soil erosion, attributed to changes in soil water repellency and vegetation recovery. The model was then assessed by applying it for a sum of 18 experimental micro-plots (0.25 m2) at 9 1x-burnt and 9 4x-burnt slopes, using both literature-based and calibrated parameters, with the collected data used to assess the robustness of each parameterization. The estimate of erosion was more exact than that of runoff, with a general Nash-Sutcliffe efficiency of 0.54. Slope angle and the soil's effective hydrological depth (which relies on upon vegetation and additionally crop cover) were found to be the primary parameters enhancing model results, and different hydrological depths were expected to separate between the two differentiating fire regimes. This relative analysis demonstrated that most existing benchmark parameters can be utilized to apply MMF in burnt pine regions with moderate severity to support post-fire management; however it also showed that further endeavours ought to concentrate on mapping soil depth and vegetation cover to enhance these simulations.

  15. ArcCN-Runoff: An ArcGIS tool for generating curve number and runoff maps

    Science.gov (United States)

    Zhan, X.; Huang, M.-L.

    2004-01-01

    The development and the application of ArcCN-Runoff tool, an extension of ESRI@ ArcGIS software, are reported. This tool can be applied to determine curve numbers and to calculate runoff or infiltration for a rainfall event in a watershed. Implementation of GIS techniques such as dissolving, intersecting, and a curve-number reference table improve efficiency. Technical processing time may be reduced from days, if not weeks, to hours for producing spatially varied curve number and runoff maps. An application example for a watershed in Lyon County and Osage County, Kansas, USA, is presented. ?? 2004 Elsevier Ltd. All rights reserved.

  16. Multiple time scale analysis of sediment and runoff changes in the Lower Yellow River

    Directory of Open Access Journals (Sweden)

    K. Chi

    2018-06-01

    Full Text Available Sediment and runoff changes of seven hydrological stations along the Lower Yellow River (LYR (Huayuankou Station, Jiahetan Station, Gaocun Station, Sunkou Station, Ai Shan Station, Qikou Station and Lijin Station from 1980 to 2003 were alanyzed at multiple time scale. The maximum value of monthly, daily and hourly sediment load and runoff conservations were also analyzed with the annually mean value. Mann–Kendall non-parametric mathematics correlation test and Hurst coefficient method were adopted in the study. Research results indicate that (1 the runoff of seven hydrological stations was significantly reduced in the study period at different time scales. However, the trends of sediment load in these stations were not obvious. The sediment load of Huayuankou, Jiahetan and Aishan stations even slightly increased with the runoff decrease. (2 The trends of the sediment load with different time scale showed differences at Luokou and Lijin stations. Although the annually and monthly sediment load were broadly flat, the maximum hourly sediment load showed decrease trend. (3 According to the Hurst coefficients, the trend of sediment and runoff will be continue without taking measures, which proved the necessary of runoff-sediment regulation scheme.

  17. Topographical controls on soil moisture distribution and runoff response in a first order alpine catchment

    Science.gov (United States)

    Penna, Daniele; Gobbi, Alberto; Mantese, Nicola; Borga, Marco

    2010-05-01

    Hydrological processes driving runoff generation in mountain basins depend on a wide number of factors which are often strictly interconnected. Among them, topography is widely recognized as one of the dominant controls influencing soil moisture distribution in the root zone, depth to water table and location and extent of saturated areas possibly prone to runoff production. Morphological properties of catchments are responsible for the alternation between steep slopes and relatively flat areas which have the potentials to control the storage/release of water and hence the hydrological response of the whole watershed. This work aims to: i) identify the role of topography as the main factor controlling the spatial distribution of near-surface soil moisture; ii) evaluate the possible switch in soil moisture spatial organization between wet and relatively dry periods and the stability of patterns during triggering of surface/subsurface runoff; iii) assess the possible connection between the develop of an ephemeral river network and the groundwater variations, examining the influence of the catchment topographical properties on the hydrological response. Hydro-meteorological data were collected in a small subcatchment (Larch Creek Catchment, 0.033 km²) of Rio Vauz basin (1.9 km²), in the eastern Italian Alps. Precipitation, discharge, water table level over a net of 14 piezometric wells and volumetric soil moisture at 0-30 cm depth were monitored continuously during the late spring-early autumn months in 2007 and 2008. Soil water content at 0-6 and 0-20 cm depth was measured manually during 22 field surveys in summer 2007 over a 44-sampling point experimental plot (approximately 3000 m²). In summer 2008 the sampling grid was extended to 64 points (approximately 4500 m²) and 28 field surveys were carried out. The length of the ephemeral stream network developed during rainfall events was assessed by a net of 24 Overland Flow Detectors (OFDs), which are able to

  18. Impact of different parts of unpaved forest roads on runoff and sediment yield in a Mediterranean area.

    Science.gov (United States)

    Jordán-López, Antonio; Martínez-Zavala, Lorena; Bellinfante, Nicolás

    2009-01-01

    Surface runoff and sediment production on unpaved forest roads in a humid Mediterranean mountainous area has been studied using a simple portable rainfall simulator at an intensity of 90 mm h(-1). Thirty six rainfall simulations were carried out on road plots: on the roadbank (12), on the sidecast fill (12), and on the roadbed (12). On the roadbanks, the steady-state runoff coefficient was 85.9% and runoff flow appeared after 63 s on average. On the sidecast fills, the steady-state runoff coefficient was 58.6% and mean time to runoff was 48 s. Finally, on the roadbeds, the steady-state runoff coefficient was 21.5% and mean time to runoff was 41 s. The highest soil loss rate was found on the roadbanks (486.7 g m(-2)), mainly due to low plant cover, soil texture and rock fragments. The total soil erosion on the roadbanks was 3 and 18 times higher than those from the roadbeds and the sidecast fills, respectively. As a consequence, roadbanks can be considered the main source of sediments on the studied sites, but the function of unpaved forest roads as source points for runoff generation is more important.

  19. Assessment of the effect of land use /land cover changes on total runoff from Ofu River catchment in Nigeria

    Directory of Open Access Journals (Sweden)

    Meshach Ileanwa Alfa

    2018-04-01

    Full Text Available The total runoff from a catchment is dependednt on both the soil characteristics and the land use/land cover (LULC type. This study was conducted to examine the effect of changes in land cover on the total runoff from Ofu River Catchment in Nigeria. Classified Landsat imageries of 1987, 2001 and 2016 in combination with the soil map extracted from the Digital Soil Map of the World was used to estimate the runoff curve number for 1987, 2001 and 2016. The runoff depth for 35 years daily rainfall data was estimated using Natura Resource Conservation Services Curve Number (NRCS-CN method. The runoff depths obtained for the respective years were subjected to a one-way analysis of variance at 95% level of significance. P-value < 0.05 was taken as statistically significant. Runoff curve numbers obtained for 1987, 2001 and 2016 were 61.83, 63.26 and 62.79 respectively. The effects of the changes in LULC for 1987-2001, 2001-2016 and 1987-2016 were statistically significant (P<0.001 at 95% confident interval.  The average change in runoff depths were 79.81%, -11.10% and 48.09% respectively for 1987-2001, 2001-2016 and 1987-2016. The study concluded that the changes in LULC of the catchment had significant effect on the runoff from the catchment.

  20. Mid- and long-term runoff predictions by an improved phase-space reconstruction model

    International Nuclear Information System (INIS)

    Hong, Mei; Wang, Dong; Wang, Yuankun; Zeng, Xiankui; Ge, Shanshan; Yan, Hengqian; Singh, Vijay P.

    2016-01-01

    In recent years, the phase-space reconstruction method has usually been used for mid- and long-term runoff predictions. However, the traditional phase-space reconstruction method is still needs to be improved. Using the genetic algorithm to improve the phase-space reconstruction method, a new nonlinear model of monthly runoff is constructed. The new model does not rely heavily on embedding dimensions. Recognizing that the rainfall–runoff process is complex, affected by a number of factors, more variables (e.g. temperature and rainfall) are incorporated in the model. In order to detect the possible presence of chaos in the runoff dynamics, chaotic characteristics of the model are also analyzed, which shows the model can represent the nonlinear and chaotic characteristics of the runoff. The model is tested for its forecasting performance in four types of experiments using data from six hydrological stations on the Yellow River and the Yangtze River. Results show that the medium-and long-term runoff is satisfactorily forecasted at the hydrological stations. Not only is the forecasting trend accurate, but also the mean absolute percentage error is no more than 15%. Moreover, the forecast results of wet years and dry years are both good, which means that the improved model can overcome the traditional ‘‘wet years and dry years predictability barrier,’’ to some extent. The model forecasts for different regions are all good, showing the universality of the approach. Compared with selected conceptual and empirical methods, the model exhibits greater reliability and stability in the long-term runoff prediction. Our study provides a new thinking for research on the association between the monthly runoff and other hydrological factors, and also provides a new method for the prediction of the monthly runoff. - Highlights: • The improved phase-space reconstruction model of monthly runoff is established. • Two variables (temperature and rainfall) are incorporated

  1. Mid- and long-term runoff predictions by an improved phase-space reconstruction model

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Mei [Research Center of Ocean Environment Numerical Simulation, Institute of Meteorology and oceanography, PLA University of Science and Technology, Nanjing (China); Wang, Dong, E-mail: wangdong@nju.edu.cn [Key Laboratory of Surficial Geochemistry, Ministry of Education, Department of Hydrosciences, School of Earth Sciences and Engineering, Collaborative Innovation Center of South China Sea Studies, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing 210093 (China); Wang, Yuankun; Zeng, Xiankui [Key Laboratory of Surficial Geochemistry, Ministry of Education, Department of Hydrosciences, School of Earth Sciences and Engineering, Collaborative Innovation Center of South China Sea Studies, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing 210093 (China); Ge, Shanshan; Yan, Hengqian [Research Center of Ocean Environment Numerical Simulation, Institute of Meteorology and oceanography, PLA University of Science and Technology, Nanjing (China); Singh, Vijay P. [Department of Biological and Agricultural Engineering Zachry Department of Civil Engineering, Texas A & M University, College Station, TX 77843 (United States)

    2016-07-15

    In recent years, the phase-space reconstruction method has usually been used for mid- and long-term runoff predictions. However, the traditional phase-space reconstruction method is still needs to be improved. Using the genetic algorithm to improve the phase-space reconstruction method, a new nonlinear model of monthly runoff is constructed. The new model does not rely heavily on embedding dimensions. Recognizing that the rainfall–runoff process is complex, affected by a number of factors, more variables (e.g. temperature and rainfall) are incorporated in the model. In order to detect the possible presence of chaos in the runoff dynamics, chaotic characteristics of the model are also analyzed, which shows the model can represent the nonlinear and chaotic characteristics of the runoff. The model is tested for its forecasting performance in four types of experiments using data from six hydrological stations on the Yellow River and the Yangtze River. Results show that the medium-and long-term runoff is satisfactorily forecasted at the hydrological stations. Not only is the forecasting trend accurate, but also the mean absolute percentage error is no more than 15%. Moreover, the forecast results of wet years and dry years are both good, which means that the improved model can overcome the traditional ‘‘wet years and dry years predictability barrier,’’ to some extent. The model forecasts for different regions are all good, showing the universality of the approach. Compared with selected conceptual and empirical methods, the model exhibits greater reliability and stability in the long-term runoff prediction. Our study provides a new thinking for research on the association between the monthly runoff and other hydrological factors, and also provides a new method for the prediction of the monthly runoff. - Highlights: • The improved phase-space reconstruction model of monthly runoff is established. • Two variables (temperature and rainfall) are incorporated

  2. Experimental study of the effects of alternating fields on HTS coils according to the winding insulation conditions

    International Nuclear Information System (INIS)

    Hwang, Y J; Lee, T S; Lee, W S; Ko, T K; Ahn, M C

    2013-01-01

    This paper examines the effects of alternating fields on high-temperature superconducting (HTS) coils according to the winding insulation condition. Alternating fields can occur in synchronous machines (armature reaction, faults) and other devices. In superconducting synchronous machines, alternating fields affect the operational characteristics of the machine and the superconducting field coil. Therefore, a method of reducing the effects of alternating fields is necessary in superconducting synchronous design. In this study, the effects of alternating fields on the HTS field coil according to the winding insulation condition were experimentally evaluated. The experimental results show that HTS coils made using the no-insulation technique can be a solution for reducing the effects of the alternating field. These results are expected to suggest useful data for applications of HTS field coils in superconducting synchronous machines. (paper)

  3. Direct measurements of meltwater runoff on the Greenland ice sheet surface.

    Science.gov (United States)

    Smith, Laurence C; Yang, Kang; Pitcher, Lincoln H; Overstreet, Brandon T; Chu, Vena W; Rennermalm, Åsa K; Ryan, Jonathan C; Cooper, Matthew G; Gleason, Colin J; Tedesco, Marco; Jeyaratnam, Jeyavinoth; van As, Dirk; van den Broeke, Michiel R; van de Berg, Willem Jan; Noël, Brice; Langen, Peter L; Cullather, Richard I; Zhao, Bin; Willis, Michael J; Hubbard, Alun; Box, Jason E; Jenner, Brittany A; Behar, Alberto E

    2017-12-12

    Meltwater runoff from the Greenland ice sheet surface influences surface mass balance (SMB), ice dynamics, and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream fluvial catchment area. A first 72-h trial for a 63.1-km 2 moulin-terminating internally drained catchment (IDC) on Greenland's midelevation (1,207-1,381 m above sea level) ablation zone is compared with melt and runoff simulations from HIRHAM5, MAR3.6, RACMO2.3, MERRA-2, and SEB climate/SMB models. Current models cannot reproduce peak discharges or timing of runoff entering moulins but are improved using synthetic unit hydrograph (SUH) theory. Retroactive SUH applications to two older field studies reproduce their findings, signifying that remotely sensed IDC area, shape, and supraglacial river length are useful for predicting delays in peak runoff delivery to moulins. Applying SUH to HIRHAM5, MAR3.6, and RACMO2.3 gridded melt products for 799 surrounding IDCs suggests their terminal moulins receive lower peak discharges, less diurnal variability, and asynchronous runoff timing relative to climate/SMB model output alone. Conversely, large IDCs produce high moulin discharges, even at high elevations where melt rates are low. During this particular field experiment, models overestimated runoff by +21 to +58%, linked to overestimated surface ablation and possible meltwater retention in bare, porous, low-density ice. Direct measurements of ice surface runoff will improve climate/SMB models, and incorporating remotely sensed IDCs will aid coupling of SMB with ice dynamics and subglacial systems. Copyright © 2017 the Author(s). Published by PNAS.

  4. Effectiveness of Runoff Control Legislation and Active, Beautiful, Clean (ABC Waters Design Features in Singapore

    Directory of Open Access Journals (Sweden)

    Xue Ping Goh

    2017-08-01

    Full Text Available Storm water management in Singapore has always been a challenge due to intense rainfall in a flat, low-lying and urbanised catchment. PUB’s (Singapore’s National Water Agency recent runoff control regulation limits the runoff coefficient to 0.55 for developments larger than or equal to 0.2 ha. The use of Active, Beautiful, Clean (ABC Waters design features are encouraged to attain peak runoff reduction. Hence the paper focuses on (i determining the actual hydrological response regime of Singapore using the relationship between runoff coefficient (C, land use and slope; and (ii investigating the effectiveness of ABC Waters design features in delaying and reducing peak runoff using a modelling approach. Based on a Storm Water Management Model (SWMM model and using elevation, land use and soil data as inputs, the peak C-values were obtained for 50 m × 50 m grid cells. The results show that for the same land use, the one with steeper slope resulted in a higher runoff coefficient. Simulations were carried out in two study areas, Green Walk District and Tengah Subcatchment, where ABC Waters design features (such as porous pavements, green roofs, rain gardens and detention tanks were incorporated to reduce C-values. Results showed that peak C-values can be reduced to less than 0.55 after increasing the green areas and constructing detention facilities. Reduction in peak discharge (22% to 63% and a delay in peak discharge by up to 30 min were also observed. Hence, it is recommended to consider the relationship between slope and land use while determining runoff coefficients; and to incorporate ABC Waters design features in urban design to reduce the peak flow and runoff coefficient (C.

  5. Transport of Three Antimicrobials in Runoff from Windrows of Composting Beef Cattle Manure.

    Science.gov (United States)

    Sura, Srinivas; Degenhardt, Dani; Cessna, Allan J; Larney, Francis J; Olson, Andrew F; McAllister, Tim A

    2016-03-01

    Rain runoff from windrowed or stockpiled manure may contain antimicrobials with the potential to contaminate surface and ground water. To quantify the concentration of antimicrobials transported in runoff from windrowed manure, antimicrobials were administered continuously in feed to beef cattle () as follows: 44 mg of chlortetracycline kg feed (dry weight), a 1:1 mixture of 44 mg of chlortetracycline and 44 mg sulfamethazine kg feed, and 11 mg of tylosin kg feed. Cattle in a fourth treatment group received no antimicrobials (control). Manure from the cattle was used to construct two windrows per treatment. On Days 2 and 21 of composting, a portable Guelph Rainfall Simulator II was used to apply deionized water at an intensity of 127 mm h to each windrow, and the runoff was collected. Manure samples were collected before rain simulations on Days 2 and 21 of composting for antimicrobial analysis. On Day 2, average concentrations of chlortetracycline, sulfamethazine, and tylosin in manure were 2580, 450, and 120 μg kg, respectively, with maximum concentrations in runoff of 2740, 3600, and 4930 μg L, respectively. Concentrations of all three antimicrobials in runoff were higher ( runoff from a windrow (3 m long, 2.5 m wide, 1.5 m high) were approximately 0.87 to 0.94, 1.57, and 1.23 g, respectively. This study demonstrates the importance of windrow composting in reducing antimicrobial concentrations in manure. The runoff from windrows can be a source of antimicrobials and demonstrates the need for containment of runoff from composting facilities to mitigate antimicrobial contamination of surface and groundwater resources. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  6. Evaluation of Three Models for Simulating Pesticide Runoff from Irrigated Agricultural Fields.

    Science.gov (United States)

    Zhang, Xuyang; Goh, Kean S

    2015-11-01

    Three models were evaluated for their accuracy in simulating pesticide runoff at the edge of agricultural fields: Pesticide Root Zone Model (PRZM), Root Zone Water Quality Model (RZWQM), and OpusCZ. Modeling results on runoff volume, sediment erosion, and pesticide loss were compared with measurements taken from field studies. Models were also compared on their theoretical foundations and ease of use. For runoff events generated by sprinkler irrigation and rainfall, all models performed equally well with small errors in simulating water, sediment, and pesticide runoff. The mean absolute percentage errors (MAPEs) were between 3 and 161%. For flood irrigation, OpusCZ simulated runoff and pesticide mass with the highest accuracy, followed by RZWQM and PRZM, likely owning to its unique hydrological algorithm for runoff simulations during flood irrigation. Simulation results from cold model runs by OpusCZ and RZWQM using measured values for model inputs matched closely to the observed values. The MAPE ranged from 28 to 384 and 42 to 168% for OpusCZ and RZWQM, respectively. These satisfactory model outputs showed the models' abilities in mimicking reality. Theoretical evaluations indicated that OpusCZ and RZWQM use mechanistic approaches for hydrology simulation, output data on a subdaily time-step, and were able to simulate management practices and subsurface flow via tile drainage. In contrast, PRZM operates at daily time-step and simulates surface runoff using the USDA Soil Conservation Service's curve number method. Among the three models, OpusCZ and RZWQM were suitable for simulating pesticide runoff in semiarid areas where agriculture is heavily dependent on irrigation. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  7. Surface Runoff of Pesticides from a Clay Loam Field in Sweden.

    Science.gov (United States)

    Larsbo, Mats; Sandin, Maria; Jarvis, Nick; Etana, Ararso; Kreuger, Jenny

    2016-07-01

    Pesticides stored at or close to the soil surface after field application can be mobilized and transported off the field when surface runoff occurs. The objective of our study was to quantify the potential pesticide losses in surface runoff from a conventionally managed agricultural field in a Swedish climate. This was achieved by measuring surface runoff volumes and concentrations in runoff of six spring-applied pesticides and autumn-applied glyphosate and its metabolite aminomethylphosphonic acid (AMPA). Measurements were performed for 3 yr both during the growing seasons and during intervening winter snowmelt periods on a clay loam field close to Uppsala. During growing seasons, surface runoff was generated on only five occasions during one 25-d period in 2012 when the infiltration capacity of the soil may have been reduced by structural degradation due to large cumulative rainfall amounts after harrowing. Concentrations in surface runoff exceeded Swedish water quality standards in all samples during this growing season for diflufenican and pirimicarb. Surface runoff was generated during three snowmelt periods during the winter of 2012-2013. All of the applied pesticides were found in snowmelt samples despite incorporation of residues by autumn plowing, degradation, and leaching into the soil profile during the period between spraying and sampling. Concentrations of glyphosate ranged from 0.12 to 7.4 μg L, and concentrations of AMPA ranged from 0 to 2.7 μg L. Our results indicate that temporal changes in hydraulic properties during the growing season and when the soil freezes during winter affect pesticide losses through surface runoff. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  8. Cross-Regional Assessment Of Coupling And Variability In Precipitation-Runoff Relationships

    Science.gov (United States)

    Carey, S. K.; Tetzlaff, D.; Soulsby, C.; Buttle, J. M.; Laudon, H.; McDonnell, J. J.; McGuire, K. J.; Seibert, J.; Shanley, J. B.

    2011-12-01

    The higher mid-latitudes of the northern hemisphere are particularly sensitive to change due to the important role the zero-degree isotherm plays in the phase of precipitation and intermediate storage as snow. An international inter-catchment comparison program North-Watch seeks to improve our understanding of the sensitivity of northern catchments to change by examining their hydrological and biogeochemical variability and response. The catchments are located in Sweden (Krycklan), Scotland (Mharcaidh, Girnock and Strontian), the United States (Sleepers River, Hubbard Brook and HJ Andrews) and Canada (Catamaran, Dorset and Wolf Creek). For this study, 8 catchments with 10 continuous years of daily precipitation and runoff data were selected to assess the seasonal coupling of rainfall and runoff and the memory effect of runoff events on the hydrograph at different time scales. To assess the coupling and synchroneity of precipitation, continuous wavelet transforms and wavelet coherence were used. Wavelet spectra identified the relative importance of both annual versus seasonal flows while wavelet coherence was applied to identify over different time scales along the 10-year window how well precipitation and runoff were coupled. For example, while on a given day, precipitation may be closely coupled to runoff, a wet year may not necessarily be a high runoff year in catchments with large storage. Assessing different averaging periods in the variation of daily flows highlights the importance of seasonality in runoff response and the relative influence of rain versus snowmelt on flow magnitude and variability. Wet catchments with limited seasonal precipitation variability (Strontian, Girnock) have precipitation signals more closely coupled with runoff, whereas dryer catchments dominated by snow (Wolf Creek, Krycklan) have strongly coupling only during freshet. Most catchments with highly seasonal precipitation show strong intermittent coupling during their wet season. At

  9. Direct measurements of meltwater runoff on the Greenland ice sheet surface

    Science.gov (United States)

    Smith, Laurence C.; Yang, Kang; Pitcher, Lincoln H.; Overstreet, Brandon T.; Chu, Vena W.; Rennermalm, Åsa K.; Ryan, Jonathan C.; Cooper, Matthew G.; Gleason, Colin J.; Tedesco, Marco; Jeyaratnam, Jeyavinoth; van As, Dirk; van den Broeke, Michiel R.; van de Berg, Willem Jan; Noël, Brice; Langen, Peter L.; Cullather, Richard I.; Zhao, Bin; Willis, Michael J.; Hubbard, Alun; Box, Jason E.; Jenner, Brittany A.; Behar, Alberto E.

    2017-12-01

    Meltwater runoff from the Greenland ice sheet surface influences surface mass balance (SMB), ice dynamics, and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream fluvial catchment area. A first 72-h trial for a 63.1-km2 moulin-terminating internally drained catchment (IDC) on Greenland's midelevation (1,207–1,381 m above sea level) ablation zone is compared with melt and runoff simulations from HIRHAM5, MAR3.6, RACMO2.3, MERRA-2, and SEB climate/SMB models. Current models cannot reproduce peak discharges or timing of runoff entering moulins but are improved using synthetic unit hydrograph (SUH) theory. Retroactive SUH applications to two older field studies reproduce their findings, signifying that remotely sensed IDC area, shape, and supraglacial river length are useful for predicting delays in peak runoff delivery to moulins. Applying SUH to HIRHAM5, MAR3.6, and RACMO2.3 gridded melt products for 799 surrounding IDCs suggests their terminal moulins receive lower peak discharges, less diurnal variability, and asynchronous runoff timing relative to climate/SMB model output alone. Conversely, large IDCs produce high moulin discharges, even at high elevations where melt rates are low. During this particular field experiment, models overestimated runoff by +21 to +58%, linked to overestimated surface ablation and possible meltwater retention in bare, porous, low-density ice. Direct measurements of ice surface runoff will improve climate/SMB models, and incorporating remotely sensed IDCs will aid coupling of SMB with ice dynamics and subglacial systems.

  10. Bayesian analyses of seasonal runoff forecasts

    Science.gov (United States)

    Krzysztofowicz, R.; Reese, S.

    1991-12-01

    Forecasts of seasonal snowmelt runoff volume provide indispensable information for rational decision making by water project operators, irrigation district managers, and farmers in the western United States. Bayesian statistical models and communication frames have been researched in order to enhance the forecast information disseminated to the users, and to characterize forecast skill from the decision maker's point of view. Four products are presented: (i) a Bayesian Processor of Forecasts, which provides a statistical filter for calibrating the forecasts, and a procedure for estimating the posterior probability distribution of the seasonal runoff; (ii) the Bayesian Correlation Score, a new measure of forecast skill, which is related monotonically to the ex ante economic value of forecasts for decision making; (iii) a statistical predictor of monthly cumulative runoffs within the snowmelt season, conditional on the total seasonal runoff forecast; and (iv) a framing of the forecast message that conveys the uncertainty associated with the forecast estimates to the users. All analyses are illustrated with numerical examples of forecasts for six gauging stations from the period 1971 1988.

  11. Determination of characteristics maximal runoff Mountain Rivers

    African Journals Online (AJOL)

    Ovcharuk V and Todorova O

    Odessa State Environmental University, Ukraine. Received: 03 December 2015 / Accepted: 23 April 2016 / Published online: 01 May 2016. ABSTRACT. This article has been examined maximum runoff of the rivers of the Crimean Mountains. The rivers flow through the western and eastern part of the northern slope Crimean ...

  12. Rainwater runoff from building facades : a review

    NARCIS (Netherlands)

    Blocken, B.J.E.; Derome, D.; Carmeliet, J.E.

    2013-01-01

    Rainwater runoff from building facades is a complex process governed by a wide range of urban, building, material and meteorological parameters. Given this complexity and the wide range of influencing parameters, it is not surprising that despite research efforts spanning over almost a century,

  13. Green Roofs for Stormwater Runoff Control

    Science.gov (United States)

    This project evaluated green roofs as a stormwater management tool. Specifically, runoff quantity and quality from green and flat asphalt roofs were compared. Evapotranspiration from planted green roofs and evaporation from unplanted media roofs were also compared. The influence...

  14. Landscape runoff, precipitation variation and reservoir limnology

    OpenAIRE

    Geraldes, Ana Maria

    2010-01-01

    Landscape runoff potential impact on reservoir limnology was indirectly evaluated by assessing the effect of precipitation variation on several water quality parameters, on Anabaena (Cyanophyta) and crustacean zooplankton abundances. The obtained results showed that total phosphorus increased with strong precipitation events whereas water transparency presented an opposite trend. Wet periods followed by long dry periods favored Anabaena dominance, which induced a...

  15. water infiltration, conductivity and runoff under fallow

    African Journals Online (AJOL)

    Measurements of runoff was done during the long rains of. 2003 and short rains of 2004. Infiltration was invariably higher under agroforestry systems (P<0.001) than sole cropping, particularly under Alnus and Calliandra systems. A similar pattern was observed for saturated hydraulic conductivity (Ksat), which was greater in ...

  16. Simplified Laboratory Runoff Procedure (SLRP): Procedure and Application

    National Research Council Canada - National Science Library

    Price, Richard

    2000-01-01

    The Simplified Laboratory Runoff Procedure (SLRP) was developed to provide a faster, less expensive approach to evaluate surface runoff water quality from dredged material placed in an upland environment...

  17. Improving risk estimates of runoff producing areas: formulating variable source areas as a bivariate process.

    Science.gov (United States)

    Cheng, Xiaoya; Shaw, Stephen B; Marjerison, Rebecca D; Yearick, Christopher D; DeGloria, Stephen D; Walter, M Todd

    2014-05-01

    Predicting runoff producing areas and their corresponding risks of generating storm runoff is important for developing watershed management strategies to mitigate non-point source pollution. However, few methods for making these predictions have been proposed, especially operational approaches that would be useful in areas where variable source area (VSA) hydrology dominates storm runoff. The objective of this study is to develop a simple approach to estimate spatially-distributed risks of runoff production. By considering the development of overland flow as a bivariate process, we incorporated both rainfall and antecedent soil moisture conditions into a method for predicting VSAs based on the Natural Resource Conservation Service-Curve Number equation. We used base-flow immediately preceding storm events as an index of antecedent soil wetness status. Using nine sub-basins of the Upper Susquehanna River Basin, we demonstrated that our estimated runoff volumes and extent of VSAs agreed with observations. We further demonstrated a method for mapping these areas in a Geographic Information System using a Soil Topographic Index. The proposed methodology provides a new tool for watershed planners for quantifying runoff risks across watersheds, which can be used to target water quality protection strategies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Osmotically driven membrane process for the management of urban runoff in coastal regions.

    Science.gov (United States)

    Li, Zhenyu; Valladares Linares, Rodrigo; Abu-Ghdaib, Muhannad; Zhan, Tong; Yangali-Quintanilla, Victor; Amy, Gary

    2014-01-01

    An osmotic detention pond was proposed for the management of urban runoff in coastal regions. Forward osmosis was employed as a bridge to utilize natural osmotic energy from seawater for concentrating and reusing urban runoff water, and as a barrier to reject runoff-derived contaminants. The process was demonstrated by a lab scale testing using synthetic urban runoff (as the feed solution) and synthetic seawater (as the draw solution). The submerged forward osmosis process was conducted under neutral, acidic and natural organic matter fouling condition, respectively. Forward osmosis flux decline was mainly attributed to the dilution of seawater during a semi-batch process in lab scale testing. However, it is possible to minimize flux decrease by maintaining a constant salinity at the draw solution side. Various changes in urban runoff water quality, including acidic conditions (acid rain) and natural organic matter presence, did not show significant effects on the rejection of trace metals and phosphorus, but influenced salt leakage and the rejection of nitrate and total nitrogen. Rejection of trace metals varied from 98% to 100%, phosphorus varied from 97% to 100, nitrate varied from 52% to 94% and total nitrogen varied from 65% to 85% under different feed water conditions. The work described in this study contributes to an integrated system of urban runoff management, seawater desalination and possible power generation in coastal regions to achieve a sustainable solution to the water-energy nexus. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Effects of Climate Change and Human Activities on Surface Runoff in the Luan River Basin

    Directory of Open Access Journals (Sweden)

    Sidong Zeng

    2015-01-01

    Full Text Available Quantifying the effects of climate change and human activities on runoff changes is the focus of climate change and hydrological research. This paper presents an integrated method employing the Budyko-based Fu model, hydrological modeling, and climate elasticity approaches to separate the effects of the two driving factors on surface runoff in the Luan River basin, China. The Budyko-based Fu model and the double mass curve method are used to analyze runoff changes during the period 1958~2009. Then two types of hydrological models (the distributed Soil and Water Assessment Tool model and the lumped SIMHYD model and seven climate elasticity methods (including a nonparametric method and six Budyko-based methods are applied to estimate the contributions of climate change and human activities to runoff change. The results show that all quantification methods are effective, and the results obtained by the nine methods are generally consistent. During the study period, the effects of climate change on runoff change accounted for 28.3~46.8% while those of human activities contributed with 53.2~71.7%, indicating that both factors have significant effects on the runoff decline in the basin, and that the effects of human activities are relatively stronger than those of climate change.

  20. Soil bioretention protects juvenile salmon and their prey from the toxic impacts of urban stormwater runoff.

    Science.gov (United States)

    McIntyre, J K; Davis, J W; Hinman, C; Macneale, K H; Anulacion, B F; Scholz, N L; Stark, J D

    2015-08-01

    Green stormwater infrastructure (GSI), or low impact development, encompasses a diverse and expanding portfolio of strategies to reduce the impacts of stormwater runoff on natural systems. Benchmarks for GSI success are usually framed in terms of hydrology and water chemistry, with reduced flow and loadings of toxic chemical contaminants as primary metrics. Despite the central goal of protecting aquatic species abundance and diversity, the effectiveness of GSI treatments in maintaining diverse assemblages of sensitive aquatic taxa has not been widely evaluated. In the present study we characterized the baseline toxicity of untreated urban runoff from a highway in Seattle, WA, across six storm events. For all storms, first flush runoff was toxic to the daphniid Ceriodaphnia dubia, causing up to 100% mortality or impairing reproduction among survivors. We then evaluated whether soil media used in bioretention, a conventional GSI method, could reduce or eliminate toxicity to juvenile coho salmon (Oncorhynchus kisutch) as well as their macroinvertebrate prey, including cultured C. dubia and wild-collected mayfly nymphs (Baetis spp.). Untreated highway runoff was generally lethal to salmon and invertebrates, and this acute mortality was eliminated when the runoff was filtered through soil media in bioretention columns. Soil treatment also protected against sublethal reproductive toxicity in C. dubia. Thus, a relatively inexpensive GSI technology can be highly effective at reversing the acutely lethal and sublethal effects of urban runoff on multiple aquatic species. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Osmotically driven membrane process for the management of urban runoff in coastal regions

    KAUST Repository

    Li, Zhenyu

    2014-01-01

    An osmotic detention pond was proposed for the management of urban runoff in coastal regions. Forward osmosis was employed as a bridge to utilize natural osmotic energy from seawater for concentrating and reusing urban runoff water, and as a barrier to reject runoff-derived contaminants. The process was demonstrated by a lab scale testing using synthetic urban runoff (as the feed solution) and synthetic seawater (as the draw solution). The submerged forward osmosis process was conducted under neutral, acidic and natural organic matter fouling condition, respectively. Forward osmosis flux decline was mainly attributed to the dilution of seawater during a semi-batch process in lab scale testing. However, it is possible to minimize flux decrease by maintaining a constant salinity at the draw solution side. Various changes in urban runoff water quality, including acidic conditions (acid rain) and natural organic matter presence, did not show significant effects on the rejection of trace metals and phosphorus, but influenced salt leakage and the rejection of nitrate and total nitrogen. Rejection of trace metals varied from 98% to 100%, phosphorus varied from 97% to 100, nitrate varied from 52% to 94% and total nitrogen varied from 65% to 85% under different feed water conditions. The work described in this study contributes to an integrated system of urban runoff management, seawater desalination and possible power generation in coastal regions to achieve a sustainable solution to the water-energy nexus. © 2013 Elsevier Ltd.

  2. Nutrient losses from manure and fertilizer applications as impacted by time to first runoff event

    International Nuclear Information System (INIS)

    Smith, D.R.; Owens, P.R.; Leytem, A.B.; Warnemuende, E.A.

    2007-01-01

    Nutrient losses to surface waters following fertilization contribute to eutrophication. This study was conducted to compare the impacts of fertilization with inorganic fertilizer, swine (Sus scrofa domesticus) manure or poultry (Gallus domesticus) litter on runoff water quality, and how the duration between application and the first runoff event affects resulting water quality. Fertilizers were applied at 35 kg P ha -1 , and the duration between application and the first runoff event varied between 1 and 29 days. Swine manure was the greatest risk to water quality 1 day after fertilization due to elevated phosphorus (8.4 mg P L -1 ) and ammonium (10.3 mg NH 4 -N L -1 ) concentrations; however, this risk decreased rapidly. Phosphorus concentrations were 2.6 mg L -1 29 days after fertilization with inorganic fertilizer. This research demonstrates that manures might be more environmentally sustainable than inorganic fertilizers, provided runoff events do not occur soon after application. - Fertilization with manures results in lower nutrient runoff than inorganic fertilizers, especially if at least one week passes between fertilization and runoff

  3. Statistical attribution analysis of the nonstationarity of the annual runoff series of the Weihe River.

    Science.gov (United States)

    Xiong, Lihua; Jiang, Cong; Du, Tao

    2014-01-01

    Time-varying moments models based on Pearson Type III and normal distributions respectively are built under the generalized additive model in location, scale and shape (GAMLSS) framework to analyze the nonstationarity of the annual runoff series of the Weihe River, the largest tributary of the Yellow River. The detection of nonstationarities in hydrological time series (annual runoff, precipitation and temperature) from 1960 to 2009 is carried out using a GAMLSS model, and then the covariate analysis for the annual runoff series is implemented with GAMLSS. Finally, the attribution of each covariate to the nonstationarity of annual runoff is analyzed quantitatively. The results demonstrate that (1) obvious change-points exist in all three hydrological series, (2) precipitation, temperature and irrigated area are all significant covariates of the annual runoff series, and (3) temperature increase plays the main role in leading to the reduction of the annual runoff series in the study basin, followed by the decrease of precipitation and the increase of irrigated area.

  4. The role of basin physical property data in assessing water stress in water resources studies: The application of the Pitman Rainfall-runoff model in Nigeria

    CSIR Research Space (South Africa)

    Ayeni, AO

    2012-11-01

    Full Text Available literature (Adegbola, 1979; Oyenuga, 1967; Sobulo, 1985; Sonneveld, 1996; Iloeje, 2001; Aregheore, 2009). The monthly rainfall records of 28 years (1981 – 2008) for Asa, Owena, and Ogun basin were available for the study. As a result of challenges... is produced. The participation of the second author was made possible through the Young Researcher Establishment Fund (YREF), project number ECHS019, provided by the CSIR. References 1. Adegbola S. A. (1979): An Agricultural Atlas of Nigeria. University...

  5. Contribution to the study of the behaviour, in the urban environment, during the runoff of rainwater, of the fission products emitted during a nuclear accident

    International Nuclear Information System (INIS)

    Pioch, M.

    1993-01-01

    In the context of research into the environmental consequences of a serious accident occurring on a pressurized water reactor, this paper concerns the experimental study of behaviour of five fission products (caesium, strontium, iodine, ruthenium and tellurium) in the urban environment under the action of rainwater. Stable or radioactive multiple-element aerosols were produced. Their physicochemical characteristics and their solubility in rainwater were studied. Caesium and rubidium forms solutions totally and quickly, while strontium is partially soluble (approximately 50 %) and iodine is only slightly soluble. The behaviour of fission products on five urban surfaces was then studied. Batch experiments showed that the retention of dissolved forms of radioelements varied according to the material. The reactions involved are ion exchange reactions. The presence of certain ions in water (in particular NH 4 + ) increase the desorption of radioelements. Using a laboratory rainfall simulator, the re-entrainment of fission products by rainwater was examined. Two modes of deposition and two intensities of rainfall were simulated. The desorption of radioelements is greater after wet deposition and remobilization is reduced by an increase in intensity of rainfall. An addition of NH 4 + in water is especially effective in the case of wet depositions. Suggestions are made in order to improve experimental protocols and continue the research. (author). 75 refs., 51 figs., 69 tabs., 14 appends

  6. The fission-track analysis: An alternative technique for provenance studies of prehistoric obsidian artefacts

    CERN Document Server

    Bellot-Gurlet, L; Dorighel, O; Oddone, M; Poupeau, G; Yegingil, Z

    1999-01-01

    Comparison of fission-track parameters - age and track densities - is an alternative tool for correlating obsidian artefacts with their potential natural sources. This method was applied by different fission-track groups in various regions and results were compared with those obtained using the more popular provenance identification techniques based on chemical composition studies. Hundreds of analyses prove that fission-track dating is a complementary technique which turns out to be very useful, specially when the chemical composition does not fully discriminate different sources. Archaeologically significant results were obtained applying the fission-track analysis in various regions of earth.

  7. Use of alternative sources of energy: design study of photovoltaic based parking area lighting system

    International Nuclear Information System (INIS)

    Perraki, V.; Loucas, G.

    2000-01-01

    This study proposes the lighting of the parking area and the surrounding streets of the north west part of the University Campus of Patras, using an alternative source of energy, the photovoltaic energy. The sizing of the proposed system results to a reliable, autonomous system which covers the total of the energy needs without any maintenance. Although the energy produced is more expensive compared to the grid electricity nowadays, such solutions seem necessary and well promising for the future as the fuel reserves are limited. (authors)

  8. The fission-track analysis: An alternative technique for provenance studies of prehis