WorldWideScience

Sample records for swat model performance

  1. Transferability of SWAT Models between SWAT2009 and SWAT2012.

    Science.gov (United States)

    Seo, Mijin; Yen, Haw; Kim, Min-Kyeong; Jeong, Jaehak

    2014-05-01

    In recent years, the Soil and Water Assessment Tool (SWAT) has experienced upgrades with enhanced functionalities and modeling capacities as it gets to the current version, SWAT2012. Changes in the SWAT code on a specific process may result in propagating influences in the output of other related processes. In this study, the characteristic significance of the enhancements in SWAT code was investigated using the two recent versions, SWAT2009 and SWAT2012. Using a global optimization technique, each model was calibrated for flow, sediment, and nutrient and then tested for transferability of parameters between the models. Results indicate that flow and water quality output were well calibrated with both models. However, the calibrated parameters determined by SWAT2009 and SWAT2012 were noticeably different, due mostly to the enhancements made in SWAT2012. Our results indicate that only the stream flow result was reliable when the models were upgraded or downgraded between the two versions after calibration. Sediment prediction was marginally reliable. SWAT parameters were nontransferrable if nutrient was the main output. The differences are due to various reasons, such as disparities in algorithms at the process level and propagation of the resulting uncertainty into higher-order processes. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  2. Comparison of HSPF and SWAT models performance for runoff and sediment yield prediction.

    Science.gov (United States)

    Im, Sangjun; Brannan, Kevin M; Mostaghimi, Saied; Kim, Sang Min

    2007-09-01

    A watershed model can be used to better understand the relationship between land use activities and hydrologic/water quality processes that occur within a watershed. The physically based, distributed parameter model (SWAT) and a conceptual, lumped parameter model (HSPF), were selected and their performance were compared in simulating runoff and sediment yields from the Polecat Creek watershed in Virginia, which is 12,048 ha in size. A monitoring project was conducted in Polecat Creek watershed during the period of October 1994 to June 2000. The observed data (stream flow and sediment yield) from the monitoring project was used in the calibration/validations of the models. The period of September 1996 to June 2000 was used for the calibration and October 1994 to December 1995 was used for the validation of the models. The outputs from the models were compared to the observed data at several sub-watershed outlets and at the watershed outlet of the Polecat Creek watershed. The results indicated that both models were generally able to simulate stream flow and sediment yields well during both the calibration/validation periods. For annual and monthly loads, HSPF simulated hydrologic and sediment yield more accurately than SWAT at all monitoring sites within the watershed. The results of this study indicate that both the SWAT and HSPF watershed models performed sufficiently well in the simulation of stream flow and sediment yield with HSPF performing moderately better than SWAT for simulation time-steps greater than a month.

  3. Temporal diagnostic analysis of the SWAT model to detect dominant periods of poor model performance

    Science.gov (United States)

    Guse, Björn; Reusser, Dominik E.; Fohrer, Nicola

    2013-04-01

    Hydrological models generally include thresholds and non-linearities, such as snow-rain-temperature thresholds, non-linear reservoirs, infiltration thresholds and the like. When relating observed variables to modelling results, formal methods often calculate performance metrics over long periods, reporting model performance with only few numbers. Such approaches are not well suited to compare dominating processes between reality and model and to better understand when thresholds and non-linearities are driving model results. We present a combination of two temporally resolved model diagnostic tools to answer when a model is performing (not so) well and what the dominant processes are during these periods. We look at the temporal dynamics of parameter sensitivities and model performance to answer this question. For this, the eco-hydrological SWAT model is applied in the Treene lowland catchment in Northern Germany. As a first step, temporal dynamics of parameter sensitivities are analyzed using the Fourier Amplitude Sensitivity test (FAST). The sensitivities of the eight model parameters investigated show strong temporal variations. High sensitivities were detected for two groundwater (GW_DELAY, ALPHA_BF) and one evaporation parameters (ESCO) most of the time. The periods of high parameter sensitivity can be related to different phases of the hydrograph with dominances of the groundwater parameters in the recession phases and of ESCO in baseflow and resaturation periods. Surface runoff parameters show high parameter sensitivities in phases of a precipitation event in combination with high soil water contents. The dominant parameters give indication for the controlling processes during a given period for the hydrological catchment. The second step included the temporal analysis of model performance. For each time step, model performance was characterized with a "finger print" consisting of a large set of performance measures. These finger prints were clustered into

  4. Validation of SWAT+ at field level and comparison with previous SWAT models in simulating hydrologic quantity

    Science.gov (United States)

    GAO, J.; White, M. J.; Bieger, K.; Yen, H.; Arnold, J. G.

    2017-12-01

    Over the past 20 years, the Soil and Water Assessment Tool (SWAT) has been adopted by many researches to assess water quantity and quality in watersheds around the world. As the demand increases in facilitating model support, maintenance, and future development, the SWAT source code and data have undergone major modifications over the past few years. To make the model more flexible in terms of interactions of spatial units and processes occurring in watersheds, a completely revised version of SWAT (SWAT+) was developed to improve SWAT's ability in water resource modelling and management. There are only several applications of SWAT+ in large watersheds, however, no study pays attention to validate the new model at field level and assess its performance. To test the basic hydrologic function of SWAT+, it was implemented in five field cases across five states in the U.S. and compared the SWAT+ created results with that from the previous models at the same fields. Additionally, an automatic calibration tool was used to test which model is easier to be calibrated well in a limited number of parameter adjustments. The goal of the study was to evaluate the performance of SWAT+ in simulating stream flow on field level at different geographical locations. The results demonstrate that SWAT+ demonstrated similar performance with previous SWAT model, but the flexibility offered by SWAT+ via the connection of different spatial objects can result in a more accurate simulation of hydrological processes in spatial, especially for watershed with artificial facilities. Autocalibration shows that SWAT+ is much easier to obtain a satisfied result compared with the previous SWAT. Although many capabilities have already been enhanced in SWAT+, there exist inaccuracies in simulation. This insufficiency will be improved with advancements in scientific knowledge on hydrologic process in specific watersheds. Currently, SWAT+ is prerelease, and any errors are being addressed.

  5. Improving streamflow simulations and forecasting performance of SWAT model by assimilating remotely sensed soil moisture observations

    Science.gov (United States)

    Patil, Amol; Ramsankaran, RAAJ

    2017-12-01

    This article presents a study carried out using EnKF based assimilation of coarser-scale SMOS soil moisture retrievals to improve the streamflow simulations and forecasting performance of SWAT model in a large catchment. This study has been carried out in Munneru river catchment, India, which is about 10,156 km2. In this study, an EnkF based new approach is proposed for improving the inherent vertical coupling of soil layers of SWAT hydrological model during soil moisture data assimilation. Evaluation of the vertical error correlation obtained between surface and subsurface layers indicates that the vertical coupling can be improved significantly using ensemble of soil storages compared to the traditional static soil storages based EnKF approach. However, the improvements in the simulated streamflow are moderate, which is due to the limitations in SWAT model in reflecting the profile soil moisture updates in surface runoff computations. Further, it is observed that the durability of streamflow improvements is longer when the assimilation system effectively updates the subsurface flow component. Overall, the results of the present study indicate that the passive microwave-based coarser-scale soil moisture products like SMOS hold significant potential to improve the streamflow estimates when assimilating into large-scale distributed hydrological models operating at a daily time step.

  6. Grid based calibration of SWAT hydrological models

    Directory of Open Access Journals (Sweden)

    D. Gorgan

    2012-07-01

    Full Text Available The calibration and execution of large hydrological models, such as SWAT (soil and water assessment tool, developed for large areas, high resolution, and huge input data, need not only quite a long execution time but also high computation resources. SWAT hydrological model supports studies and predictions of the impact of land management practices on water, sediment, and agricultural chemical yields in complex watersheds. The paper presents the gSWAT application as a web practical solution for environmental specialists to calibrate extensive hydrological models and to run scenarios, by hiding the complex control of processes and heterogeneous resources across the grid based high computation infrastructure. The paper highlights the basic functionalities of the gSWAT platform, and the features of the graphical user interface. The presentation is concerned with the development of working sessions, interactive control of calibration, direct and basic editing of parameters, process monitoring, and graphical and interactive visualization of the results. The experiments performed on different SWAT models and the obtained results argue the benefits brought by the grid parallel and distributed environment as a solution for the processing platform. All the instances of SWAT models used in the reported experiments have been developed through the enviroGRIDS project, targeting the Black Sea catchment area.

  7. An Assessment of Mean Areal Precipitation Methods on Simulated Stream Flow: A SWAT Model Performance Assessment

    Directory of Open Access Journals (Sweden)

    Sean Zeiger

    2017-06-01

    Full Text Available Accurate mean areal precipitation (MAP estimates are essential input forcings for hydrologic models. However, the selection of the most accurate method to estimate MAP can be daunting because there are numerous methods to choose from (e.g., proximate gauge, direct weighted average, surface-fitting, and remotely sensed methods. Multiple methods (n = 19 were used to estimate MAP with precipitation data from 11 distributed monitoring sites, and 4 remotely sensed data sets. Each method was validated against the hydrologic model simulated stream flow using the Soil and Water Assessment Tool (SWAT. SWAT was validated using a split-site method and the observed stream flow data from five nested-scale gauging sites in a mixed-land-use watershed of the central USA. Cross-validation results showed the error associated with surface-fitting and remotely sensed methods ranging from −4.5 to −5.1%, and −9.8 to −14.7%, respectively. Split-site validation results showed the percent bias (PBIAS values that ranged from −4.5 to −160%. Second order polynomial functions especially overestimated precipitation and subsequent stream flow simulations (PBIAS = −160 in the headwaters. The results indicated that using an inverse-distance weighted, linear polynomial interpolation or multiquadric function method to estimate MAP may improve SWAT model simulations. Collectively, the results highlight the importance of spatially distributed observed hydroclimate data for precipitation and subsequent steam flow estimations. The MAP methods demonstrated in the current work can be used to reduce hydrologic model uncertainty caused by watershed physiographic differences.

  8. A fully integrated SWAT-MODFLOW hydrologic model

    Science.gov (United States)

    The Soil and Water Assessment Tool (SWAT) and MODFLOW models are being used worldwide for managing surface and groundwater water resources. The SWAT models hydrological processes occurring at the surface including shallow aquifers, while MODFLOW simulate groundwater processes. However, neither SWAT ...

  9. A GUIDED SWAT MODEL APPLICATION ON SEDIMENT YIELD MODELING IN PANGANI RIVER BASIN: LESSONS LEARNT

    Directory of Open Access Journals (Sweden)

    Preksedis Marco Ndomba

    2008-12-01

    Full Text Available The overall objective of this paper is to report on the lessons learnt from applying Soil and Water Assessment Tool (SWAT in a well guided sediment yield modelling study. The study area is the upstream of Pangani River Basin (PRB, the Nyumba Ya Mungu (NYM reservoir catchment, located in the North Eastern part of Tanzania. It should be noted that, previous modeling exercises in the region applied SWAT with preassumption that inter-rill or sheet erosion was the dominant erosion type. In contrast, in this study SWAT model application was guided by results of analysis of high temporal resolution of sediment flow data and hydro-meteorological data. The runoff component of the SWAT model was calibrated from six-years (i.e. 1977–1982 of historical daily streamflow data. The sediment component of the model was calibrated using one-year (1977–1988 daily sediment loads estimated from one hydrological year sampling programme (between March and November, 2005 rating curve. A long-term period over 37 years (i.e. 1969–2005 simulation results of the SWAT model was validated to downstream NYM reservoir sediment accumulation information. The SWAT model captured 56 percent of the variance (CE and underestimated the observed daily sediment loads by 0.9 percent according to Total Mass Control (TMC performance indices during a normal wet hydrological year, i.e., between November 1, 1977 and October 31, 1978, as the calibration period. SWAT model predicted satisfactorily the long-term sediment catchment yield with a relative error of 2.6 percent. Also, the model has identified erosion sources spatially and has replicated some erosion processes as determined in other studies and field observations in the PRB. This result suggests that for catchments where sheet erosion is dominant SWAT model may substitute the sediment-rating curve. However, the SWAT model could not capture the dynamics of sediment load delivery in some seasons to the catchment outlet.

  10. A GUIDED SWAT MODEL APPLICATION ON SEDIMENT YIELD MODELING IN PANGANI RIVER BASIN: LESSONS LEARNT

    Directory of Open Access Journals (Sweden)

    Preksedis M. Ndomba

    2008-01-01

    Full Text Available The overall objective of this paper is to report on the lessons learnt from applying Soil and Water Assessment Tool (SWAT in a well guided sediment yield modelling study. The study area is the upstream of Pangani River Basin (PRB, the Nyumba Ya Mungu (NYM reservoir catchment, located in the North Eastern part of Tanzania. It should be noted that, previous modeling exercises in the region applied SWAT with preassumption that inter-rill or sheet erosion was the dominant erosion type. In contrast, in this study SWAT model application was guided by results of analysis of high temporal resolution of sediment flow data and hydro-meteorological data. The runoff component of the SWAT model was calibrated from six-years (i.e. 1977¿1982 of historical daily streamflow data. The sediment component of the model was calibrated using one-year (1977-1988 daily sediment loads estimated from one hydrological year sampling programme (between March and November, 2005 rating curve. A long-term period over 37 years (i.e. 1969-2005 simulation results of the SWAT model was validated to downstream NYM reservoir sediment accumulation information. The SWAT model captured 56 percent of the variance (CE and underestimated the observed daily sediment loads by 0.9 percent according to Total Mass Control (TMC performance indices during a normal wet hydrological year, i.e., between November 1, 1977 and October 31, 1978, as the calibration period. SWAT model predicted satisfactorily the long-term sediment catchment yield with a relative error of 2.6 percent. Also, the model has identified erosion sources spatially and has replicated some erosion processes as determined in other studies and field observations in the PRB. This result suggests that for catchments where sheet erosion is dominant SWAT model may substitute the sediment-rating curve. However, the SWAT model could not capture the dynamics of sediment load delivery in some seasons to the catchment outlet.

  11. Consideration of drainage ditches and sediment rating cure on SWAT model performance

    Science.gov (United States)

    Water quality models most often require a considerable amount of data to be properly configured and in some cases this requires additional procedural steps prior to model applications. We examined two different scenarios of such input issues in a small watershed using the Soil and Water Assessment ...

  12. U.S. and Australian Mine Warfare Sonar Performance Assessment Using SWAT and Hodgson Models

    National Research Council Canada - National Science Library

    Dubsky, Barbra

    2000-01-01

    The purpose of this thesis was to investigate a shallow coastal region to compile a detailed environmental picture of its sediment composition and water characteristics and from this model MCM sonar...

  13. PEMODELAN DAERAH TANGKAPAN AIR WADUK KELILING DENGAN MODEL SWAT (Keliling Reservoir Catchment Area Modeling Using SWAT Model

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    Teuku Ferijal

    2015-05-01

    Full Text Available This study aimed to model watershed area of Keliling Reservoir using SWAT model. The reservoir is located in Aceh Besar District, Province of Aceh. The model was setup using 90m x 90m digital elevation model, land use data extracted from remote sensing data and soil characteristic obtained from laboratory analysis on soil samples. Model was calibrated using observed daily reservoir volume and the model performance was analyzed using RMSE-observations standard deviation ratio (RSR, Nash-Sutcliffe efficiency (NSE and percent bias (PBIAS. The model delineated the study area into 3,448 Ha having 13 subwatersheds and 76 land units (HRUs. The watershed is mostly covered by forest (53% and grassland (31%. The analysis revealed the 10 most sensitive parameters i.e. GW_DELAY, CN2, REVAPMN, ALPHA_BF, SOL_AWC, GW_REVAP, GWQMN, CH_K2 and ESCO. Model performances were categorized into very good for monthly reservoir volume with ENS 0.95, RSR 0.23, and PBIAS 2.97. The model performance decreased when it used to analyze daily reservoir inflow with ENS 0.55, RSR 0.67, and PBIAS 3.46. Keywords: Keliling Reservoir, SWAT, Watershed   ABSTRAK Penelitian ini bertujuan untuk untuk memodelkan daerah tangkapan air Waduk Keliling dengan menggunakan Model SWAT. Waduk Keliling terletak di Kabupaten Aceh Besar, Propinsi Aceh. Dalam penelitian ini Model SWAT dikembangkan berdasarkan data digital elevasi model resolusi 90 m x90 m, tata guna lahan yang diperoleh dari intepretasi citra satelit dan data soil dari hasil analisa sampel tanah yang diperoleh di daerah penelitian. Model dikalibrasi dengan data volume waduk dan kinerja model dianalisa menggunakan parameter rasio akar rata-rata kuadrat error dan standard deviasi observasi (RSR, efesiensi Nash-Sutcliffe (NSE dan persentase bias (PBIAS. Hasil deleniasi untuk daerah penelitian menghasilkan suatu DAS dengan luas 3,448 Ha dan memiliki 13 Sub DAS yang dikelompokkan menjadi 76 unit lahan. Sebagian besar wilayah study

  14. SWAT Model Configuration, Calibration and Validation for Lake Champlain Basin

    Science.gov (United States)

    The Soil and Water Assessment Tool (SWAT) model was used to develop phosphorus loading estimates for sources in the Lake Champlain Basin. This document describes the model setup and parameterization, and presents calibration results.

  15. Regionalization of SWAT Model Parameters for Use in Ungauged Watersheds

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    Indrajeet Chaubey

    2010-11-01

    Full Text Available There has been a steady shift towards modeling and model-based approaches as primary methods of assessing watershed response to hydrologic inputs and land management, and of quantifying watershed-wide best management practice (BMP effectiveness. Watershed models often require some degree of calibration and validation to achieve adequate watershed and therefore BMP representation. This is, however, only possible for gauged watersheds. There are many watersheds for which there are very little or no monitoring data available, thus the question as to whether it would be possible to extend and/or generalize model parameters obtained through calibration of gauged watersheds to ungauged watersheds within the same region. This study explored the possibility of developing regionalized model parameter sets for use in ungauged watersheds. The study evaluated two regionalization methods: global averaging, and regression-based parameters, on the SWAT model using data from priority watersheds in Arkansas. Resulting parameters were tested and model performance determined on three gauged watersheds. Nash-Sutcliffe efficiencies (NS for stream flow obtained using regression-based parameters (0.53–0.83 compared well with corresponding values obtained through model calibration (0.45–0.90. Model performance obtained using global averaged parameter values was also generally acceptable (0.4 ≤ NS ≤ 0.75. Results from this study indicate that regionalized parameter sets for the SWAT model can be obtained and used for making satisfactory hydrologic response predictions in ungauged watersheds.

  16. Applications of the SWAT Model Special Section: Overview and Insights.

    Science.gov (United States)

    Gassman, Philip W; Sadeghi, Ali M; Srinivasan, Raghavan

    2014-01-01

    The Soil and Water Assessment Tool (SWAT) model has emerged as one of the most widely used water quality watershed- and river basin-scale models worldwide, applied extensively for a broad range of hydrologic and/or environmental problems. The international use of SWAT can be attributed to its flexibility in addressing water resource problems, extensive networking via dozens of training workshops and the several international conferences that have been held during the past decade, comprehensive online documentation and supporting software, and an open source code that can be adapted by model users for specific application needs. The catalyst for this special collection of papers was the 2011 International SWAT Conference & Workshops held in Toledo, Spain, which featured over 160 scientific presentations representing SWAT applications in 37 countries. This special collection presents 22 specific SWAT-related studies, most of which were presented at the 2011 SWAT Conference; it represents SWAT applications on five different continents, with the majority of studies being conducted in Europe and North America. The papers cover a variety of topics, including hydrologic testing at a wide range of watershed scales, transport of pollutants in northern European lowland watersheds, data input and routing method effects on sediment transport, development and testing of potential new model algorithms, and description and testing of supporting software. In this introduction to the special section, we provide a synthesis of these studies within four main categories: (i) hydrologic foundations, (ii) sediment transport and routing analyses, (iii) nutrient and pesticide transport, and (iv) scenario analyses. We conclude with a brief summary of key SWAT research and development needs. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  17. Automating calibration, sensitivity and uncertainty analysis of complex models using the R package Flexible Modeling Environment (FME): SWAT as an example

    Science.gov (United States)

    Wu, Y.; Liu, S.

    2012-01-01

    Parameter optimization and uncertainty issues are a great challenge for the application of large environmental models like the Soil and Water Assessment Tool (SWAT), which is a physically-based hydrological model for simulating water and nutrient cycles at the watershed scale. In this study, we present a comprehensive modeling environment for SWAT, including automated calibration, and sensitivity and uncertainty analysis capabilities through integration with the R package Flexible Modeling Environment (FME). To address challenges (e.g., calling the model in R and transferring variables between Fortran and R) in developing such a two-language coupling framework, 1) we converted the Fortran-based SWAT model to an R function (R-SWAT) using the RFortran platform, and alternatively 2) we compiled SWAT as a Dynamic Link Library (DLL). We then wrapped SWAT (via R-SWAT) with FME to perform complex applications including parameter identifiability, inverse modeling, and sensitivity and uncertainty analysis in the R environment. The final R-SWAT-FME framework has the following key functionalities: automatic initialization of R, running Fortran-based SWAT and R commands in parallel, transferring parameters and model output between SWAT and R, and inverse modeling with visualization. To examine this framework and demonstrate how it works, a case study simulating streamflow in the Cedar River Basin in Iowa in the United Sates was used, and we compared it with the built-in auto-calibration tool of SWAT in parameter optimization. Results indicate that both methods performed well and similarly in searching a set of optimal parameters. Nonetheless, the R-SWAT-FME is more attractive due to its instant visualization, and potential to take advantage of other R packages (e.g., inverse modeling and statistical graphics). The methods presented in the paper are readily adaptable to other model applications that require capability for automated calibration, and sensitivity and uncertainty

  18. Streamflow data assimilation in SWAT model using Extended Kalman Filter

    Science.gov (United States)

    Sun, Leqiang; Nistor, Ioan; Seidou, Ousmane

    2015-12-01

    The Extended Kalman Filter (EKF) is coupled with the Soil and Water Assessment Tools (SWAT) model in the streamflow assimilation of the upstream Senegal River in West Africa. Given the large number of distributed variables in SWAT, only the average watershed scale variables are included in the state vector and the Hydrological Response Unit (HRU) scale variables are updated with the a posteriori/a priori ratio of their watershed scale counterparts. The Jacobian matrix is calculated numerically by perturbing the state variables. Both the soil moisture and CN2 are significantly updated in the wet season, yet they have opposite update patterns. A case study for a large flood forecast shows that for up to seven days, the streamflow forecast is moderately improved using the EKF-subsequent open loop scheme but significantly improved with a newly designed quasi-error update scheme. The former has better performances in the flood rising period while the latter has better performances in the recession period. For both schemes, the streamflow forecast is improved more significantly when the lead time is shorter.

  19. Improving the spatial representation of basin hydrology and flow processes in the SWAT model

    OpenAIRE

    Rathjens, Hendrik

    2014-01-01

    This dissertation aims at improving the spatial representation of basin hydrology and flow processes in the SWAT model. Die vorliegende Dissertation stellt die methodischen Grundlage zur räumlich differenzierten Modellierung mit dem Modell SWAT dar.

  20. Analisis Laju Sedimen DAS Serayu Hulu dengan Menggunakan Model SWAT

    Directory of Open Access Journals (Sweden)

    Nugroho Christanto

    2018-03-01

    Full Text Available Wilayah DAS Serayu Hulu merupakan DAS prioritas yang memerlukan langkah pengelolaan yang komprehensif. Aplikasi model Soil and Water Assessment Tool (SWAT dapat digunakan sebagai media untuk  perencanaan konservasi ataupun evaluasi respon DAS (debit aliran permukaan, sedimen dan pencemaran sungai. Tujuan utama dari penelitian ini adalah menjalankan model SWAT di DAS Serayu Hulu untuk mengetahui laju sedimen di wilayah ini. Pemodelan SWAT membutuhkan sejumlah input parameter berupa relief, tanah, tutupan lahan dan pengelolaan lahan. Pedogeomorfologi digunakan sebagai batas satuan tanah karena tidak tersedianya peta tanah di wilayah penelitian. Hasil Penerapan model SWAT di DAS Serayu Hulu menghasilkan nilai yang cukup memuaskan, hal ini ditunjukkan nilai R2 mencapai 0,94. Hasil pemodelan SWAT dengan menggunakan data selama 10 tahun (2004-2013 menunjukkan bahwa DAS Serayu Hulu memiliki rerata hasil sedimen sebesar 1.926.900 ton/tahun. Sub DAS 8,9 11, 17, 18, dan 19 merupakan penghasil sedimen tertinggi di DAS Serayu Hulu dengan hasil sedimen 43.931– 121.434 ton/ha/tahun.

  1. Pesticide modelling for a small catchment using SWAT-2000.

    Science.gov (United States)

    Kannan, Narayanan; White, Sue M; Worrall, Fred; Whelan, Mick J

    2006-01-01

    Pesticides in stream flow from the 142 ha Colworth catchment in Bedfordshire, UK were monitored from October 1999 to December 2000. About 47% of the catchment is tile-drained and different pesticides and cropping patterns have recently been evaluated in terms of their effect on nutrient and pesticide losses to the stream. The data from Colworth were used to test soil and water assessment tool (SWAT) 2000 predictions of pesticide concentrations at the catchment outlet. A sound model set-up to carry out pesticide modelling was created by means of hydrological modelling with proper simulation of crop growth and evapotranspiration. The pesticides terbuthylazine, terbutryn, cyanazine and bentazone were modelled. There was close agreement between SWAT-predicted pesticide concentration values and observations. Scenario trials were conducted to explore management options for reducing pesticide loads arriving at the catchment outlet. The results obtained indicate that SWAT can be used as a tool to understand pesticide behavior at the catchment scale.

  2. Experiments on injection performance of SMART ECC facility using SWAT

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Il; Cho, Seok; Ko, Yung Joo; Min, Kyoung Ho; Shin, Yong Cheol; Kwon, Tae Soon; Yi, Sung Jae; Lee, Won Jae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    SMART (System-integrated Modular Advanced ReacTor), an advanced integrated PWR is now in the under developing stages by KAERI. Such integral PWR excludes large-size piping of the primary system of conventional PWR and incorporates the SGs into RPV, which means no LBLOCA could occur in SMART. Therefore, the SBLOCA is considered as a major DBA (Design Basis Accident) in SMART and it is mainly analyzed by using TASS/SMR computer code. The TASS/SMR code should be validated using experimental data from both Integral Effect Test and Separate Effect Test facilities. To investigate injection performance of the ECC system, on SET facility, named as SWAT (SMART ECC Water Asymmetric Two-phase choking test facility), has been constructed at KAERI. The SWAT simulates the geometric configurations of the SG-side upper downcomer annulus and ECCSs of those of SMART. It is designed based on the modified linear scaling method with a scaling ratio of 1/5, to preserve the geometrical similarity and minimize gravitational distortion. The purpose of the SWAT tests is to investigate the safety injection performance, such as the ECC bypass in the downcomer and the penetration rate in the core during the SBLOCA, and hence to produce experimental data to validate and the prediction capability of safety analysis codes, TASS/SMR

  3. Introducing a new open source GIS user interface for the SWAT model

    Science.gov (United States)

    The Soil and Water Assessment Tool (SWAT) model is a robust watershed modelling tool. It typically uses the ArcSWAT interface to create its inputs. ArcSWAT is public domain software which works in the licensed ArcGIS environment. The aim of this paper was to develop an open source user interface ...

  4. Improving the performance of temperature index snowmelt model of SWAT by using MODIS land surface temperature data.

    Science.gov (United States)

    Yang, Yan; Onishi, Takeo; Hiramatsu, Ken

    2014-01-01

    Simulation results of the widely used temperature index snowmelt model are greatly influenced by input air temperature data. Spatially sparse air temperature data remain the main factor inducing uncertainties and errors in that model, which limits its applications. Thus, to solve this problem, we created new air temperature data using linear regression relationships that can be formulated based on MODIS land surface temperature data. The Soil Water Assessment Tool model, which includes an improved temperature index snowmelt module, was chosen to test the newly created data. By evaluating simulation performance for daily snowmelt in three test basins of the Amur River, performance of the newly created data was assessed. The coefficient of determination (R (2)) and Nash-Sutcliffe efficiency (NSE) were used for evaluation. The results indicate that MODIS land surface temperature data can be used as a new source for air temperature data creation. This will improve snow simulation using the temperature index model in an area with sparse air temperature observations.

  5. SWAT-based streamflow and embayment modeling of Karst-affected Chapel branch watershed, South Carolina

    Science.gov (United States)

    Devendra Amatya; M. Jha; A.E. Edwards; T.M. Williams; D.R. Hitchcock

    2011-01-01

    SWAT is a GIS-based basin-scale model widely used for the characterization of hydrology and water quality of large, complex watersheds; however, SWAT has not been fully tested in watersheds with karst geomorphology and downstream reservoir-like embayment. In this study, SWAT was applied to test its ability to predict monthly streamflow dynamics for a 1,555 ha karst...

  6. 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...

  7. Validating soil phosphorus routines in the SWAT model

    Science.gov (United States)

    Phosphorus transfer from agricultural soils to surface waters is an important environmental issue. Commonly used models like SWAT have not always been updated to reflect improved understanding of soil P transformations and transfer to runoff. Our objective was to validate the ability of the P routin...

  8. Application of WRF - SWAT OpenMI 2.0 based models integration for real time hydrological modelling and forecasting

    Science.gov (United States)

    Bugaets, Andrey; Gonchukov, Leonid

    2014-05-01

    Intake of deterministic distributed hydrological models into operational water management requires intensive collection and inputting of spatial distributed climatic information in a timely manner that is both time consuming and laborious. The lead time of the data pre-processing stage could be essentially reduced by coupling of hydrological and numerical weather prediction models. This is especially important for the regions such as the South of the Russian Far East where its geographical position combined with a monsoon climate affected by typhoons and extreme heavy rains caused rapid rising of the mountain rivers water level and led to the flash flooding and enormous damage. The objective of this study is development of end-to-end workflow that executes, in a loosely coupled mode, an integrated modeling system comprised of Weather Research and Forecast (WRF) atmospheric model and Soil and Water Assessment Tool (SWAT 2012) hydrological model using OpenMI 2.0 and web-service technologies. Migration SWAT into OpenMI compliant involves reorganization of the model into a separate initialization, performing timestep and finalization functions that can be accessed from outside. To save SWAT normal behavior, the source code was separated from OpenMI-specific implementation into the static library. Modified code was assembled into dynamic library and wrapped into C# class implemented the OpenMI ILinkableComponent interface. Development of WRF OpenMI-compliant component based on the idea of the wrapping web-service clients into a linkable component and seamlessly access to output netCDF files without actual models connection. The weather state variables (precipitation, wind, solar radiation, air temperature and relative humidity) are processed by automatic input selection algorithm to single out the most relevant values used by SWAT model to yield climatic data at the subbasin scale. Spatial interpolation between the WRF regular grid and SWAT subbasins centroid (which are

  9. Hydrological modeling of the Simly Dam watershed (Pakistan using GIS and SWAT model

    Directory of Open Access Journals (Sweden)

    Shimaa M. Ghoraba

    2015-09-01

    Full Text Available Modern mathematical models have been developed for studying the complex hydrological processes of a watershed and their direct relation to weather, topography, geology and land use. In this study the hydrology of Simly Dam watershed located in Saon River basin at the north-east of Islamabad is modeled, using the Soil and Water Assessment Tool (SWAT. It aims to simulate the stream flow, establish the water balance and estimate the monthly volume inflow to Simly Dam in order to help the managers to plan and handle this important reservoir. The ArcSWAT interface implemented in the ArcGIS software was used to delineate the study area and its sub-components, combine the data layers and edit the model database. The model was calibrated from 1990 to 2001 and evaluated from 2002 to 2011. Based on four recommended statistical coefficients, the evaluation indicates a good performance for both calibration and validation periods and acceptable agreement between measured and simulated values of both annual and monthly scale discharge. The water balance components were correctly estimated and the Simly Dam inflow was successfully reproduced with Coefficient of Determination (R2 of 0.75. These results revealed that if properly calibrated, SWAT model can be used efficiently in semi-arid regions to support water management policies.

  10. Slope effects on SWAT modeling in a mountainous basin

    OpenAIRE

    Yacoub López, Cristina; Pérez Foguet, Agustí

    2013-01-01

    The soil and water assessment tool (SWAT) is a distributed basin model that includes the option of defining spatial discretization in terms of terrain slope. Influence of terrain slope in runoff results from mountain basins is a determining factor in its simulation results; however, its use as a criterion for basin discretization and for the parameter calibration has not yet been analyzed. In this study, this influence is analyzed for calibrations using two different cases. Ten discretization...

  11. Improvement and application of the PCPF-1@SWAT2012 model for predicting pesticide transport: A case study of the Sakura River watershed.

    Science.gov (United States)

    Tu, Le Hoang; Boulange, Julien; Iwafune, Takashi; Yadav, Ishwar Chandra; Watanabe, Hirozumi

    2018-04-15

    The PCPF-1@SWAT model was previously developed to simulate the fate and transport of rice pesticide in watersheds. However, the current model is deficient in characterize the rice paddy area and is incompatible with the ArcSWAT2012 program. In this study, we modified original PCPF1@SWAT model to develop new PCPF1@SWAT2012 model to address the deficiency of rice paddy area and utilizing the ArcSWAT2012 program. Next, the new model was applied in Sakura River watershed, Ibaraki, Japan in order to simulate the transport of four herbicides including mefenacet, pretilachlor, bensulfuron-methyl and imazosulfuron. The result showed that the simulated water flow rate by the PCPF1@SWAT2012 was well predicted with the observed data. The calculated NSE (0.73) and PBIAS (-20.38), suggested the satisfactory performance of the model. Besides, the concentrations of herbicides simulated by the PCPF-1@SWAT2012 model were in good agreement with the observed data. Statistical indices, NSE and RMSE estimated for mefenacet (0.69 and 0.18), pretilachlor (0.86 and 0.18), bensulfuronmethyl (0.46 and 0.21) and imazosulfuron (0.64 and 0.28) indicated satisfactory predictions, respectively. The PCPF-1@SWAT2012 model is capable of well simulating the water flow rate and transport of herbicides in given watershed, comprising different land use types, including rice paddy area. This article is protected by copyright. All rights reserved.

  12. Prediction of phosphorus loads in an artificially drained lowland catchment using a modified SWAT model

    Science.gov (United States)

    Bauwe, Andreas; Eckhardt, Kai-Uwe; Lennartz, Bernd

    2017-04-01

    Eutrophication is still one of the main environmental problems in the Baltic Sea. Currently, agricultural diffuse sources constitute the major portion of phosphorus (P) fluxes to the Baltic Sea and have to be reduced to achieve the HELCOM targets and improve the ecological status. Eco-hydrological models are suitable tools to identify sources of nutrients and possible measures aiming at reducing nutrient loads into surface waters. In this study, the Soil and Water Assessment Tool (SWAT) was applied to the Warnow river basin (3300 km2), the second largest watershed in Germany discharging into the Baltic Sea. The Warnow river basin is located in northeastern Germany and characterized by lowlands with a high proportion of artificially drained areas. The aim of this study were (i) to estimate P loadings for individual flow fractions (point sources, surface runoff, tile flow, groundwater flow), spatially distributed on sub-basin scale. Since the official version of SWAT does not allow for the modeling of P in tile drains, we tested (ii) two different approaches of simulating P in tile drains by changing the SWAT source code. The SWAT source code was modified so that (i) the soluble P concentration of the groundwater was transferred to the tile water and (ii) the soluble P in the soil was transferred to the tiles. The SWAT model was first calibrated (2002-2011) and validated (1992-2001) for stream flow at 7 headwater catchments at a daily time scale. Based on this, the stream flow at the outlet of the Warnow river basin was simulated. Performance statistics indicated at least satisfactory model results for each sub-basin. Breaking down the discharge into flow constituents, it becomes visible that stream flow is mainly governed by groundwater and tile flow. Due to the topographic situation with gentle slopes, surface runoff played only a minor role. Results further indicate that the prediction of soluble P loads was improved by the modified SWAT versions. Major sources of

  13. SWAT Modeling for Depression-Dominated Areas: How Do Depressions Manipulate Hydrologic Modeling?

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    Mohsen Tahmasebi Nasab

    2017-01-01

    Full Text Available Modeling hydrologic processes for depression-dominated areas such as the North American Prairie Pothole Region is complex and reliant on a clear understanding of dynamic filling-spilling-merging-splitting processes of numerous depressions over the surface. Puddles are spatially distributed over a watershed and their sizes, storages, and interactions vary over time. However, most hydrologic models fail to account for these dynamic processes. Like other traditional methods, depressions are filled as a required preprocessing step in the Soil and Water Assessment Tool (SWAT. The objective of this study was to facilitate hydrologic modeling for depression-dominated areas by coupling SWAT with a Puddle Delineation (PD algorithm. In the coupled PD-SWAT model, the PD algorithm was utilized to quantify topographic details, including the characteristics, distribution, and hierarchical relationships of depressions, which were incorporated into SWAT at the hydrologic response unit (HRU scale. The new PD-SWAT model was tested for a large watershed in North Dakota under real precipitation events. In addition, hydrologic modeling of a small watershed was conducted under two extreme high and low synthetic precipitation conditions. In particular, the PD-SWAT was compared against the regular SWAT based on depressionless DEMs. The impact of depressions on the hydrologic modeling of the large and small watersheds was evaluated. The simulation results for the large watershed indicated that SWAT systematically overestimated the outlet discharge, which can be attributed to the failure to account for the hydrologic effects of depressions. It was found from the PD-SWAT modeling results that at the HRU scale surface runoff initiation was significantly delayed due to the threshold control of depressions. Under the high precipitation scenario, depressions increased the surface runoff peak. However, the low precipitation scenario could not fully fill depressions to reach

  14. Evaluation of best management practices under intensive irrigation using SWAT model

    OpenAIRE

    Dechmi, Farida; Skhiri, Ahmed

    2013-01-01

    Land management practices such as conservation tillage and optimum irrigation are routinely used to reduce non-point source pollution and improve water quality. The calibrated and validated SWAT-IRRIG model is the first modified SWAT version that reproduces well the irrigation return flows (IRF) when the irrigation source is outside of the watershed. The application of this SWAT version in intensive irrigated systems permits to better evaluate the best management practices (BMPs) in such syst...

  15. Multivariate Bias Correction Procedures for Improving Water Quality Predictions from the SWAT Model

    Science.gov (United States)

    Arumugam, S.; Libera, D.

    2017-12-01

    Water quality observations are usually not available on a continuous basis for longer than 1-2 years at a time over a decadal period given the labor requirements making calibrating and validating mechanistic models difficult. Further, any physical model predictions inherently have bias (i.e., under/over estimation) and require post-simulation techniques to preserve the long-term mean monthly attributes. This study suggests a multivariate bias-correction technique and compares to a common technique in improving the performance of the SWAT model in predicting daily streamflow and TN loads across the southeast based on split-sample validation. The approach is a dimension reduction technique, canonical correlation analysis (CCA) that regresses the observed multivariate attributes with the SWAT model simulated values. The common approach is a regression based technique that uses an ordinary least squares regression to adjust model values. The observed cross-correlation between loadings and streamflow is better preserved when using canonical correlation while simultaneously reducing individual biases. Additionally, canonical correlation analysis does a better job in preserving the observed joint likelihood of observed streamflow and loadings. These procedures were applied to 3 watersheds chosen from the Water Quality Network in the Southeast Region; specifically, watersheds with sufficiently large drainage areas and number of observed data points. The performance of these two approaches are compared for the observed period and over a multi-decadal period using loading estimates from the USGS LOADEST model. Lastly, the CCA technique is applied in a forecasting sense by using 1-month ahead forecasts of P & T from ECHAM4.5 as forcings in the SWAT model. Skill in using the SWAT model for forecasting loadings and streamflow at the monthly and seasonal timescale is also discussed.

  16. Simulating Landscape Sediment Transport Capacity by Using a Modified SWAT Model.

    Science.gov (United States)

    Bonumá, Nadia B; Rossi, Colleen G; Arnold, Jeffrey G; Reichert, José M; Minella, Jean P; Allen, Peter M; Volk, Martin

    2014-01-01

    Sediment delivery from hillslopes to rivers is spatially variable and may lead to long-term delays between initial erosion and related sediment yield at the watershed outlet. Consideration of spatial variability is important for developing sound strategies for water quality improvement and soil protection at the watershed scale. Hence, the Soil and Water Assessment Tool (SWAT) was modified and tested in this study to simulate the landscape transport capacity of sediment. The study area was the steeply sloped Arroio Lino watershed in southern Brazil. Observed sediment yield data at the watershed outlet were used to calibrate and validate a modified SWAT model. For the calibration period, the modified model performed better than the unaltered SWAT2009 version; the models achieved Nash-Sutcliffe efficiency (NSE) values of 0.7 and -0.1, respectively. Nash-Sutcliffe efficiencies were less for the validation period, but the modified model's NSE was higher than the unaltered model (-1.4 and -12.1, respectively). Despite the relatively low NSE values, the results of this first test are promising because the model modifications lowered the percent bias in sediment yield from 73 to 18%. Simulation results for the modified model indicated that approximately 60% of the mobilized soil is deposited along the landscape before it reaches the river channels. This research demonstrates the modified model's ability to simulate sediment yield in watersheds with steep slopes. The results suggest that integration of the sediment deposition routine in SWAT increases accuracy in steeper areas while significantly improving its ability to predict the spatial distribution of sediment deposition areas. Further work is needed regarding (i) improved strategies for spatially distributed sediment transport measurements (for improving process knowledge and model evaluation) and (ii) extensive model tests in other well instrumented experimental watersheds with differing topographic configurations

  17. Modeling of discharge and sediment transport through the SWAT model in the basin of Harraza (Northwest of Algeria

    Directory of Open Access Journals (Sweden)

    Faiza Hallouz

    2018-04-01

    Full Text Available The objective of this study is to model discharge and solid erosion quantification through a small agricultural watershed by applying the SWAT model (Soil and Water Assessment Tools on the Wadi Harraza’s basin of which is part of Wadi Cheliff’s basin, with an average altitude of 500 m, drains an area of 568 sq km. Soil and Water Assessment Tool (SWAT, version 2009 model integrated with Geographic Information System (ArcGIS, version 10.0 were used to simulate the discharge and sediment concentration of Wadi Harraza’s basin for the period from 2004 to 2009. Model calibration and validation were performed for monthly time periods using Sequential Uncertainty Fitting 2 (SUFI-2, version 2 within SWAT-CUP. Our calibration and validation outputs for monthly simulation showed a good model performance for discharges. Thus the evolution of the average total annual sediment in the Wadi Harraza’s basin which will be deposited in the Wadi Cheliff, is estimated at 54.24 t ha−1. Keywords: SWAT model, Basin, Wadi Harraza, SUFI-2, Discharges, Sediment

  18. Using StorAge Selection Functions to Improve Simulation of Groundwater Nitrate Lag Times in the SWAT Modeling Framework.

    Science.gov (United States)

    Wilusz, D. C.; Fuka, D.; Cho, C.; Ball, W. P.; Easton, Z. M.; Harman, C. J.

    2017-12-01

    Intensive agriculture and atmospheric deposition have dramatically increased the input of reactive nitrogen into many watersheds worldwide. Reactive nitrogen can leach as nitrate into groundwater, which is stored and eventually released over years to decades into surface waters, potentially degrading water quality. To simulate the fate and transport of groundwater nitrate, many researchers and practitioners use the Soil and Water Assessment Tool (SWAT) or an enhanced version of SWAT that accounts for topographically-driven variable source areas (TopoSWAT). Both SWAT and TopoSWAT effectively assume that nitrate in the groundwater reservoir is well-mixed, which is known to be a poor assumption at many sites. In this study, we describe modifications to TopoSWAT that (1) relax the assumption of groundwater well-mixedness, (2) more flexibly parameterize groundwater transport as a time-varying distribution of travel times using the recently developed theory of rank StorAge Selection (rSAS) functions, and (3) allow for groundwater age to be represented by position on the hillslope or hydrological distance from the stream. The approach conceptualizes the groundwater aquifer as a population of water parcels entering as recharge with a particular nitrate concentration, aging as they move through storage, and eventually exiting as baseflow. The rSAS function selects the distribution of parcel ages that exit as baseflow based on a parameterized probability distribution; this distribution can be adjusted to preferentially select different distributions of young and old parcels in storage so as to reproduce (in principle) any form of transport. The modified TopoSWAT model (TopoSWAT+rSAS) is tested at a small agricultural catchment in the Eastern Shore, MD with an extensive hydrologic and hydrochemical data record for calibration and evaluation. The results examine (1) the sensitivity of TopoSWAT+rSAS modeling of nitrate transport to assumptions about the distribution of travel

  19. SWAT application in intensive irrigation systems: Model modification, calibration and validation

    Science.gov (United States)

    Dechmi, Farida; Burguete, Javier; Skhiri, Ahmed

    2012-11-01

    SummaryThe Soil and Water Assessment Tool (SWAT) is a well established, distributed, eco-hydrologic model. However, using the study case of an agricultural intensive irrigated watershed, it was shown that all the model versions are not able to appropriately reproduce the total streamflow in such system when the irrigation source is outside the watershed. The objective of this study was to modify the SWAT2005 version for correctly simulating the main hydrological processes. Crop yield, total streamflow, total suspended sediment (TSS) losses and phosphorus load calibration and validation were performed using field survey information and water quantity and quality data recorded during 2008 and 2009 years in Del Reguero irrigated watershed in Spain. The goodness of the calibration and validation results was assessed using five statistical measures, including the Nash-Sutcliffe efficiency (NSE). Results indicated that the average annual crop yield and actual evapotranspiration estimations were quite satisfactory. On a monthly basis, the values of NSE were 0.90 (calibration) and 0.80 (validation) indicating that the modified model could reproduce accurately the observed streamflow. The TSS losses were also satisfactorily estimated (NSE = 0.72 and 0.52 for the calibration and validation steps). The monthly temporal patterns and all the statistical parameters indicated that the modified SWAT-IRRIG model adequately predicted the total phosphorus (TP) loading. Therefore, the model could be used to assess the impacts of different best management practices on nonpoint phosphorus losses in irrigated systems.

  20. Application of the SWAT model to the Xiangjiang river watershed in subtropical central China.

    Science.gov (United States)

    Luo, Qiao; Li, Yong; Wang, Kelin; Wu, Jinshui

    2013-01-01

    The Soil and Water Assessment Tool (SWAT) model was applied to simulate the water balance in the Xiangjiang river watershed for current and planning scenarios of land uses. The model was first calibrated for the period from 1998 to 2002 and then validated for the period from 2003 to 2007 using the observed stream flow data from four monitoring gages within the watershed. The determination coefficient of linear regression of the observed and simulated monthly stream flows (R(2)) and their Nash-Sutcliffe Index (NSI) was used to evaluate model performance. All values of R(2) and NSI were above 0.8 and ranged from 0.82 to 0.92, which indicates that the SWAT model was capable of simulating the stream flow in the Xiangjiang river watershed. The calibrated and validated SWAT model was then applied to study the hydrological response of three land use change scenarios. Runoff was reduced by increasing the areas of forest and grassland while simultaneously decreasing the areas of agricultural and urban land. In the recent and future land use planning for the Xiangjiang river watershed, the hydrological effect should be considered in regional water management and erosion control.

  1. Hydrosedimentological modeling of watershed in southeast Brazil, using SWAT

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    Maria Lúcia Calijuri

    2010-08-01

    Full Text Available The quantitative evaluation of soil loss due to erosion, of water loss and of load sediments that reach water bodies is fundamental to the environmental planning of a watershed, contributing to the process of decision for best options for soil tillage and water quality maintenance. Estimates of these data have been accomplished throughout the world using empiric or conceptual models. Besides being economically viable in scenarios development, environmental models may contribute to the location of critical areas, leading to emergency contention operations caused by erosive processes. Among these models, we highlight the SWAT (Soil and Water Assessment Tool which was applied in São Bartolomeu watershed, located in the Zona da Mata, Minas Gerais state, southeastern Brazil, to identify areas of greater sensitivity to erosion considering the soil type and land use. To validate the model, 10 experimental plots were installed in the dominant crops of the watershed between 2006 and 2008, for monitoring the runoff and soil losses under natural rainfall. Field results and simulations showed the SWAT efficiency for sediment yield and soil losses estimations, as they are influenced by factors such as soil moisture, rainfall intensity, soil type and land use (dominated by Oxisols, Ultisols, Inceptisols and Entisols. These losses can be reduced significantly by improving crops management of. A simulation scenario replacing pastures cover by Eucalyptus was introduced, which significantly reduced soil loss in many parts of the watershed.

  2. Transforming SWAT for continental-scale high-resolution modeling of floodplain dynamics: opportunities and challenges

    Science.gov (United States)

    Rajib, A.; Merwade, V.; Liu, Z.; Lane, C.; Golden, H. E.; Tavakoly, A. A.; Follum, M. L.

    2017-12-01

    There have been many initiatives to develop frameworks for continental-scale modeling and mapping floodplain dynamics. The choice of a model for such needs should be governed by its suitability to be executed in high performance cyber platforms, ability to integrate supporting hydraulic/hydrodynamic tools, and ability to assimilate earth observations. Furthermore, disseminating large volume of outputs for public use and interoperability with similar frameworks should be considered. Considering these factors, we have conducted a series of modeling experiments and developed a suite of cyber-enabled platforms that have transformed Soil and Water Assessment Tool (SWAT) into an appropriate model for use in a continental-scale, high resolution, near real-time flood information framework. Our first experiment uses a medium size watershed in Indiana, USA and attempts burning-in a high resolution, National Hydrography Dataset Plus(NHDPlus) into the SWAT model. This is crucial with a view to make the outputs comparable with other global/national initiatives. The second experiment is built upon the first attempt to add a modified landscape representation in the model which differentiates between the upland and floodplain processes. Our third experiment involves two separate efforts: coupling SWAT with a hydrodynamic model LISFLOOD-FP and a new generation, low complexity hydraulic model AutoRoute. We have executed the prototype "loosely-coupled" models for the Upper Mississippi-Ohio River Basin in the USA, encompassing 1 million square km drainage area and nearly 0.2 million NHDPlus river reaches. The preliminary results suggest reasonable accuracy for both streamflow and flood inundation. In this presentation, we will also showcase three cyber-enabled platforms, including SWATShare to run and calibrate large scale SWAT models online using high performance computational resources, HydroGlobe to automatically extract and assimilate multiple remotely sensed earth observations in

  3. Modeling the impact of nitrogen fertilizer application and tile drain configuration on nitrate leaching using SWAT

    Science.gov (United States)

    Recently, the Soil and Water Assessment Tool (SWAT) was revised to improve the partitioning of runoff and tile drainage in poorly drained soils by modifying the algorithm for computing the soil moisture retention parameter. In this study, the revised SWAT model was used to evaluate the sensitivity a...

  4. Using expert knowledge of the hydrological system to constrain multi-objective calibration of SWAT models

    Science.gov (United States)

    The SWAT model is a helpful tool to predict hydrological processes in a study catchment and their impact on the river discharge at the catchment outlet. For reliable discharge predictions, a precise simulation of hydrological processes is required. Therefore, SWAT has to be calibrated accurately to ...

  5. SWAT Check: A Screening Tool to Assist Users in the Identification of Potential Model Application Problems.

    Science.gov (United States)

    White, Michael J; Harmel, R Daren; Arnold, Jeff G; Williams, Jimmy R

    2014-01-01

    The Soil and Water Assessment Tool (SWAT) is a basin-scale hydrologic model developed by the United States Department of Agriculture Agricultural Research Service. SWAT's broad applicability, user-friendly model interfaces, and automatic calibration software have led to a rapid increase in the number of new users. These advancements also allow less experienced users to conduct SWAT modeling applications. In particular, the use of automated calibration software may produce simulated values that appear appropriate because they adequately mimic measured data used in calibration and validation. Autocalibrated model applications (and often those of unexperienced modelers) may contain input data errors and inappropriate parameter adjustments not readily identified by users or the autocalibration software. The objective of this research was to develop a program to assist users in the identification of potential model application problems. The resulting "SWAT Check" is a stand-alone Microsoft Windows program that (i) reads selected SWAT output and alerts users of values outside the typical range; (ii) creates process-based figures for visualization of the appropriateness of output values, including important outputs that are commonly ignored; and (iii) detects and alerts users of common model application errors. By alerting users to potential model application problems, this software should assist the SWAT community in developing more reliable modeling applications. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  6. Integrasi Model SWAT dan SIG dalam Upaya Menekan Laju Erosi DAD Deli, Sumatera Utara

    Directory of Open Access Journals (Sweden)

    Riki Rahmad

    2017-04-01

    Full Text Available Penelitian ini bertujuan untuk melakukan simulasi model SWAT dalam menghitung besarnya laju erosi DAS, menguji kesesuaian model dalam memprediksi erosi, serta menentukan skenario penggunaan lahan yang paling optimal menurunkan laju erosi. Penelitian ini dilakukan di DAS Deli, Sumatera Utara. Pada penelitian ini analisis SWAT dilakukan dengan bantuan Sistem Informasi Geografi (SIG melalui 4 proses yaitu delineasi, pembentukan Hydrological Response Unit (HRU, pengolahan data dan simulasi, serta proses visualisasi. Hasil penelitian menunjukkan besarnya erosi rata-rata DAS Deli adalah 410,72 ton/ha/tahun. Hasil ini menunjukkan DAS Deli termasuk kedalam Tingkat Bahaya Erosi (TBE kategori Berat dengan kriteria sangat berat 37,04%, berat 17,07%, sedang 21,46%, ringan 17,38%, dan sangat ringan 7,04%. Uji validasi model menunjukkan bahwa ada hubungan positif antara debit model dan observasi dimana persentase perbedaan nilainya sangat kecil yang artinya besarnya debit model hampir sangat mendekati besarnya debit observasi, serta model dikategorikan sangat baik dalam melakukan simulasi debit aliran harian pada Sungai Deli. Metode skenario adalah berdasarkan analisis TBE. Hasil skenario penggunaan lahan berhasil menurunkan laju erosi DAS Deli 34,78% menjadi 267,88 ton/ha/tahun. This study aims to conduct SWAT model simulation calculation of the rate of erosion of the watershed, testing the suitability of the model in predicting erosion, land use scenarios and determine the most optimal decrease the rate of erosion. This research was conducted in the watershed Deli, North Sumatra. In this study, SWAT analysis performed with the help of Geographical Information Systems (GIS through 4 delineation process, namely, the establishment of Hydrological Response Unit (HRU, data processing and simulation, as well as the visualization process. The results show the average amount of erosion DAS Deli is 410.72 ton/ha/year. These results indicate DAS Deli included into

  7. ASSESSMENT OF WATER BALANCE OF A WATERSHED USING SWAT MODEL FOR WATER RESOURCES MANAGEMENT

    OpenAIRE

    Sandra George; Sathian, K.K.

    2016-01-01

    An attempt has been made in this study to assess the hydrological behavior of the Kurumali sub basin of Karuvannur river basin using SWAT model and other geospatial technologies. All the thematic maps and attribute information of the watershed have been collected from various Government agencies. SWAT model has been set up for the Kurumali sub basin by inputting the digital thematic maps, physical properties of soil and climatic parameters. Total area of the watershed corresponding to the out...

  8. SWAT application in intensive irrigation systems: Model modification, calibration and validation

    OpenAIRE

    Dechmi, Farida; Burguete, Javier; Skhiri, Ahmed

    2012-01-01

    The Soil and Water Assessment Tool (SWAT) is a well established, distributed, eco-hydrologic model. However, using the study case of an agricultural intensive irrigated watershed, it was shown that all the model versions are not able to appropriately reproduce the total streamflow in such system when the irrigation source is outside the watershed. The objective of this study was to modify the SWAT2005 version for correctly simulating the main hydrological processes. Crop yield, total streamfl...

  9. Simulation of agricultural non-point source pollution in Xichuan by using SWAT model

    Science.gov (United States)

    Xing, Linan; Zuo, Jiane; Liu, Fenglin; Zhang, Xiaohui; Cao, Qiguang

    2018-02-01

    This paper evaluated the applicability of using SWAT to access agricultural non-point source pollution in Xichuan area. In order to build the model, DEM, soil sort and land use map, climate monitoring data were collected as basic database. The SWAT model was calibrated and validated for the SWAT was carried out using streamflow, suspended solids, total phosphorus and total nitrogen records from 2009 to 2011. Errors, coefficient of determination and Nash-Sutcliffe coefficient were considered to evaluate the applicability. The coefficient of determination were 0.96, 0.66, 0.55 and 0.66 for streamflow, SS, TN, and TP, respectively. Nash-Sutcliffe coefficient were 0.93, 0.5, 0.52 and 0.63, respectively. The results all meet the requirements. It suggested that the SWAT model can simulate the study area.

  10. Parameterization and Uncertainty Analysis of SWAT model in Hydrological Simulation of Chaohe River Basin

    Science.gov (United States)

    Jie, M.; Zhang, J.; Guo, B. B.

    2017-12-01

    As a typical distributed hydrological model, the SWAT model also has a challenge in calibrating parameters and analysis their uncertainty. This paper chooses the Chaohe River Basin China as the study area, through the establishment of the SWAT model, loading the DEM data of the Chaohe river basin, the watershed is automatically divided into several sub-basins. Analyzing the land use, soil and slope which are on the basis of the sub-basins and calculating the hydrological response unit (HRU) of the study area, after running SWAT model, the runoff simulation values in the watershed are obtained. On this basis, using weather data, known daily runoff of three hydrological stations, combined with the SWAT-CUP automatic program and the manual adjustment method are used to analyze the multi-site calibration of the model parameters. Furthermore, the GLUE algorithm is used to analyze the parameters uncertainty of the SWAT model. Through the sensitivity analysis, calibration and uncertainty study of SWAT, the results indicate that the parameterization of the hydrological characteristics of the Chaohe river is successful and feasible which can be used to simulate the Chaohe river basin.

  11. Modeling crop water productivity using a coupled SWAT-MODSIM model

    Science.gov (United States)

    This study examines the water productivity of irrigated wheat and maize yields in Karkheh River Basin (KRB) in the semi-arid region of Iran using a coupled modeling approach consisting of the hydrological model (SWAT) and the river basin water allocation model (MODSIM). Dynamic irrigation requireme...

  12. Assessing Thermally Stressful Events in a Rhode Island Coldwater Fish Habitat Using the SWAT Model

    Directory of Open Access Journals (Sweden)

    Britta Chambers

    2017-09-01

    Full Text Available It has become increasingly important to recognize historical water quality trends so that the future impacts of climate change may be better understood. Climate studies have suggested that inland stream temperatures and average streamflow will increase over the next century in New England, thereby putting aquatic species sustained by coldwater habitats at risk. In this study we evaluated two different approaches for modeling historical streamflow and stream temperature in a Rhode Island, USA, watershed with the Soil and Water Assessment Tool (SWAT, using (i original SWAT and (ii SWAT plus a hydroclimatological model component that considers both hydrological inputs and air temperature. Based on daily calibration results with six years of measured streamflow and four years of stream temperature data, we examined occurrences of stressful conditions for brook trout (Salvelinus fontinalis using the hydroclimatological model. SWAT with the hydroclimatological component improved modestly during calibration (NSE of 0.93, R2 of 0.95 compared to the original SWAT (NSE of 0.83, R2 of 0.93. Between 1980–2009, the number of stressful events, a moment in time where high or low flows occur simultaneously with stream temperatures exceeding 21 °C, increased by 55% and average streamflow increased by 60%. This study supports using the hydroclimatological SWAT component and provides an example method for assessing stressful conditions in southern New England’s coldwater habitats.

  13. Historical Streamflow Series Analysis Applied to Furnas HPP Reservoir Watershed Using the SWAT Model

    Directory of Open Access Journals (Sweden)

    Viviane de Souza Dias

    2018-04-01

    Full Text Available Over the last few years, the operation of the Furnas Hydropower Plant (HPP reservoir, located in the Grande River Basin, has been threatened due to a significant reduction in inflow. In the region, hydrological modelling tools are being used and tested to support decision making and water sustainability. In this study, the streamflow was modelled in the area of direct influence of the Furnas HPP reservoir, and the Soil and Water Assessment Tool (SWAT model performance was verified for studies in the region. Analyses of sensitivity and uncertainty were undertaken using the Sequential Uncertainty Fitting algorithm (SUFI-2 with a Calibration Uncertainty Program (SWAT-CUP. The hydrological modelling, at a monthly scale, presented good results in the calibration (NS 0.86, with a slight reduction of the coefficient in the validation period (NS 0.64. The results suggested that this tool could be applied in future hydrological studies in the region of study. With the consideration that special attention should be given to the historical series used in the calibration and validation of the models. It is important to note that this region has high demands for water resources, primarily for agricultural use. Water demands must also be taken into account in future hydrological simulations. The validation of this methodology led to important contributions to the management of water resources in regions with tropical climates, whose climatological and geological reality resembles the one studied here.

  14. Pathogen Transport and Fate Modeling in the Upper Salem River Watershed Using SWAT Model

    Science.gov (United States)

    SWAT (Soil and Water Assessment Tool) is a dynamic watershed model that is applied to simulate the impact of land management practices on water quality over a continuous period. The Upper Salem River, located in Salem County New Jersey, is listed by the New Jersey Department of ...

  15. A Comparison of SWAT and ANN Models for Daily Runoff Simulation in Different Climatic Zones of Peninsular Spain

    OpenAIRE

    Patricia Jimeno-Sáez; Javier Senent-Aparicio; Julio Pérez-Sánchez; David Pulido-Velazquez

    2018-01-01

    Streamflow data are of prime importance to water-resources planning and management, and the accuracy of their estimation is very important for decision making. The Soil and Water Assessment Tool (SWAT) and Artificial Neural Network (ANN) models have been evaluated and compared to find a method to improve streamflow estimation. For a more complete evaluation, the accuracy and ability of these streamflow estimation models was also established separately based on their performance during differe...

  16. Evaluation of precipitation input for SWAT modeling in Alpine catchment: A case study in the Adige river basin (Italy).

    Science.gov (United States)

    Tuo, Ye; Duan, Zheng; Disse, Markus; Chiogna, Gabriele

    2016-12-15

    Precipitation is often the most important input data in hydrological models when simulating streamflow. The Soil and Water Assessment Tool (SWAT), a widely used hydrological model, only makes use of data from one precipitation gauge station that is nearest to the centroid of each subbasin, which is eventually corrected using the elevation band method. This leads in general to inaccurate representation of subbasin precipitation input data, particularly in catchments with complex topography. To investigate the impact of different precipitation inputs on the SWAT model simulations in Alpine catchments, 13years (1998-2010) of daily precipitation data from four datasets including OP (Observed precipitation), IDW (Inverse Distance Weighting data), CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) and TRMM (Tropical Rainfall Measuring Mission) has been considered. Both model performances (comparing simulated and measured streamflow data at the catchment outlet) as well as parameter and prediction uncertainties have been quantified. For all three subbasins, the use of elevation bands is fundamental to match the water budget. Streamflow predictions obtained using IDW inputs are better than those obtained using the other datasets in terms of both model performance and prediction uncertainty. Models using the CHIRPS product as input provide satisfactory streamflow estimation, suggesting that this satellite product can be applied to this data-scarce Alpine region. Comparing the performance of SWAT models using different precipitation datasets is therefore important in data-scarce regions. This study has shown that, precipitation is the main source of uncertainty, and different precipitation datasets in SWAT models lead to different best estimate ranges for the calibrated parameters. This has important implications for the interpretation of the simulated hydrological processes. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  17. Annual theme report (October 2007 to September 2008) for the environmental impact (SWAT modeling) component of "Agroforestry and Sustainable Vegetable Production in Southeast Asian Watersheds" project

    OpenAIRE

    Ella, Victor B.

    2008-01-01

    The implementation of the Environmental Impact (SWAT Modeling) component of this SANREM CRSP project in year 3 was highlighted by further work on SWAT model development in Indonesia, Philippines and Vietnam. In all three countries, additional input data have been collected over the past year for SWAT modeling purposes. Data Elevation Models (DEMs), land use maps and soil maps have also been prepared in all three countries. In the Philippines, SWAT model has been developed for assessing the hy...

  18. A Comparison of SWAT and ANN Models for Daily Runoff Simulation in Different Climatic Zones of Peninsular Spain

    Directory of Open Access Journals (Sweden)

    Patricia Jimeno-Sáez

    2018-02-01

    Full Text Available Streamflow data are of prime importance to water-resources planning and management, and the accuracy of their estimation is very important for decision making. The Soil and Water Assessment Tool (SWAT and Artificial Neural Network (ANN models have been evaluated and compared to find a method to improve streamflow estimation. For a more complete evaluation, the accuracy and ability of these streamflow estimation models was also established separately based on their performance during different periods of flows using regional flow duration curves (FDCs. Specifically, the FDCs were divided into five sectors: very low, low, medium, high and very high flow. This segmentation of flow allows analysis of the model performance for every important discharge event precisely. In this study, the models were applied in two catchments in Peninsular Spain with contrasting climatic conditions: Atlantic and Mediterranean climates. The results indicate that SWAT and ANNs were generally good tools in daily streamflow modelling. However, SWAT was found to be more successful in relation to better simulation of lower flows, while ANNs were superior at estimating higher flows in all cases.

  19. Assessment of NASA's Physiographic and Meteorological Datasets as Input to HSPF and SWAT Hydrological Models

    Science.gov (United States)

    Alacron, Vladimir J.; Nigro, Joseph D.; McAnally, William H.; OHara, Charles G.; Engman, Edwin Ted; Toll, David

    2011-01-01

    This paper documents the use of simulated Moderate Resolution Imaging Spectroradiometer land use/land cover (MODIS-LULC), NASA-LIS generated precipitation and evapo-transpiration (ET), and Shuttle Radar Topography Mission (SRTM) datasets (in conjunction with standard land use, topographical and meteorological datasets) as input to hydrological models routinely used by the watershed hydrology modeling community. The study is focused in coastal watersheds in the Mississippi Gulf Coast although one of the test cases focuses in an inland watershed located in northeastern State of Mississippi, USA. The decision support tools (DSTs) into which the NASA datasets were assimilated were the Soil Water & Assessment Tool (SWAT) and the Hydrological Simulation Program FORTRAN (HSPF). These DSTs are endorsed by several US government agencies (EPA, FEMA, USGS) for water resources management strategies. These models use physiographic and meteorological data extensively. Precipitation gages and USGS gage stations in the region were used to calibrate several HSPF and SWAT model applications. Land use and topographical datasets were swapped to assess model output sensitivities. NASA-LIS meteorological data were introduced in the calibrated model applications for simulation of watershed hydrology for a time period in which no weather data were available (1997-2006). The performance of the NASA datasets in the context of hydrological modeling was assessed through comparison of measured and model-simulated hydrographs. Overall, NASA datasets were as useful as standard land use, topographical , and meteorological datasets. Moreover, NASA datasets were used for performing analyses that the standard datasets could not made possible, e.g., introduction of land use dynamics into hydrological simulations

  20. Hydrologic and atrazine simulation of the Cedar Creek Watershed using the SWAT model.

    Science.gov (United States)

    Larose, M; Heathman, G C; Norton, L D; Engel, B

    2007-01-01

    One of the major factors contributing to surface water contamination in agricultural areas is the use of pesticides. The Soil and Water Assessment Tool (SWAT) is a hydrologic model capable of simulating the fate and transport of pesticides in an agricultural watershed. The SWAT model was used in this study to estimate stream flow and atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) losses to surface water in the Cedar Creek Watershed (CCW) within the St. Joseph River Basin in northeastern Indiana. Model calibration and validation periods consisted of five and two year periods, respectively. The National Agricultural Statistics Survey (NASS) 2001 land cover classification and the Soil Survey Geographic (SSURGO) database were used as model input data layers. Data from the St. Joseph River Watershed Initiative and the Soil and Water Conservation Districts of Allen, Dekalb, and Noble counties were used to represent agricultural practices in the watershed which included the type of crops grown, tillage practices, fertilizer, and pesticide application rates. Model results were evaluated based on efficiency coefficient values, standard statistical measures, and visual inspection of the measured and simulated hydrographs. The Nash and Sutcliffe model efficiency coefficients (E(NS)) for monthly and daily stream flow calibration and validation ranged from 0.51 to 0.66. The E(NS) values for atrazine calibration and validation ranged from 0.43 to 0.59. All E(NS) values were within the range of acceptable model performance standards. The results of this study indicate that the model is an effective tool in capturing the dynamics of stream flow and atrazine concentrations on a large-scale agricultural watershed in the midwestern USA.

  1. Code modernization and modularization of APEX and SWAT watershed simulation models

    Science.gov (United States)

    SWAT (Soil and Water Assessment Tool) and APEX (Agricultural Policy / Environmental eXtender) are respectively large and small watershed simulation models derived from EPIC Environmental Policy Integrated Climate), a field-scale agroecology simulation model. All three models are coded in FORTRAN an...

  2. Simulation of a low-gradient Coastal Plain watershed using the SWAT landscape model

    Science.gov (United States)

    Accurate representation of landscape processes in natural resource models requires distributed representation of basin hydrology and transport processes. To better represent these processes, a landscape version of the SWAT model has been developed. The model has been modified to represent the runo...

  3. Hydrological modeling of the Simly Dam watershed (Pakistan) using GIS and SWAT model

    OpenAIRE

    Shimaa M. Ghoraba

    2015-01-01

    Modern mathematical models have been developed for studying the complex hydrological processes of a watershed and their direct relation to weather, topography, geology and land use. In this study the hydrology of Simly Dam watershed located in Saon River basin at the north-east of Islamabad is modeled, using the Soil and Water Assessment Tool (SWAT). It aims to simulate the stream flow, establish the water balance and estimate the monthly volume inflow to Simly Dam in order to help the manage...

  4. Effects of soil data resolution on SWAT model stream flow and water quality predictions.

    Science.gov (United States)

    Geza, Mengistu; McCray, John E

    2008-08-01

    The prediction accuracy of agricultural nonpoint source pollution models such as Soil and Water Assessment Tool (SWAT) depends on how well model input spatial parameters describe the characteristics of the watershed. The objective of this study was to assess the effects of different soil data resolutions on stream flow, sediment and nutrient predictions when used as input for SWAT. SWAT model predictions were compared for the two US Department of Agriculture soil databases with different resolution, namely the State Soil Geographic database (STATSGO) and the Soil Survey Geographic database (SSURGO). Same number of sub-basins was used in the watershed delineation. However, the number of HRUs generated when STATSGO and SSURGO soil data were used is 261 and 1301, respectively. SSURGO, with the highest spatial resolution, has 51 unique soil types in the watershed distributed in 1301 HRUs, while STATSGO has only three distributed in 261 HRUS. As a result of low resolution STATSGO assigns a single classification to areas that may have different soil types if SSURGO were used. SSURGO included Hydrologic Response Units (HRUs) with soil types that were generalized to one soil group in STATSGO. The difference in the number and size of HRUs also has an effect on sediment yield parameters (slope and slope length). Thus, as a result of the discrepancies in soil type and size of HRUs stream flow predicted was higher when SSURGO was used compared to STATSGO. SSURGO predicted less stream loading than STATSGO in terms of sediment and sediment-attached nutrients components, and vice versa for dissolved nutrients. When compared to mean daily measured flow, STATSGO performed better relative to SSURGO before calibration. SSURGO provided better results after calibration as evaluated by R(2) value (0.74 compared to 0.61 for STATSGO) and the Nash-Sutcliffe coefficient of Efficiency (NSE) values (0.70 and 0.61 for SSURGO and STATSGO, respectively) although both are in the same satisfactory

  5. Modeling riverine nitrate export from an East-Central Illinois watershed using SWAT.

    Science.gov (United States)

    Hu, X; McIsaac, G F; David, M B; Louwers, C A L

    2007-01-01

    Reliable water quality models are needed to forecast the water quality consequences of different agricultural nutrient management scenarios. In this study, the Soil and Water Assessment Tool (SWAT), version 2000, was applied to simulate streamflow, riverine nitrate (NO(3)) export, crop yield, and watershed nitrogen (N) budgets in the upper Embarras River (UER) watershed in east-central Illinois, which has extensive maize-soybean cultivation, large N fertilizer input, and extensive tile drainage. During the calibration (1994-2002) and validation (1985-1993) periods, SWAT simulated monthly and annual stream flows with Nash-Sutcliffe coefficients (E) ranging from 0.67 to 0.94 and R(2) from 0.75 to 0.95. For monthly and annual NO(3) loads, E ranged from -0.16 to 0.45 and R(2) from 0.36 to 0.74. Annual maize and soybean yields were simulated with relative errors ranging from -10 to 6%. The model was then used to predict the changes in NO(3) output with N fertilizer application rates 10 to 50% lower than original application rates in UER. The calibrated SWAT predicted a 10 to 43% decrease in NO(3) export from UER and a 6 to 38% reduction in maize yield in response to the reduction in N fertilizer. The SWAT model markedly overestimated NO(3) export during major wet periods. Moreover, SWAT estimated soybean N fixation rates considerably greater than literature values, and some simulated changes in the N cycle in response to fertilizer reduction seemed to be unrealistic. Improving these aspects of SWAT could lead to more reliable predictions in the water quality outcomes of nutrient management practices in tile-drained watersheds.

  6. The modified SWAT model for predicting fecal coliforms in the Wachusett Reservoir Watershed, USA.

    Science.gov (United States)

    Cho, Kyung Hwa; Pachepsky, Yakov A; Kim, Joon Ha; Kim, Jung-Woo; Park, Mi-Hyun

    2012-10-01

    This study assessed fecal coliform contamination in the Wachusett Reservoir Watershed in Massachusetts, USA using Soil and Water Assessment Tool (SWAT) because bacteria are one of the major water quality parameters of concern. The bacteria subroutine in SWAT, considering in-stream bacteria die-off only, was modified in this study to include solar radiation-associated die-off and the contribution of wildlife. The result of sensitivity analysis demonstrates that solar radiation is one of the most significant fate factors of fecal coliform. A water temperature-associated function to represent the contribution of beaver activity in the watershed to fecal contamination improved prediction accuracy. The modified SWAT model provides an improved estimate of bacteria from the watershed. Our approach will be useful for simulating bacterial concentrations to provide predictive and reliable information of fecal contamination thus facilitating the implementation of effective watershed management. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Developing Land Use Land Cover Maps for the Lower Mekong Basin to Aid SWAT Hydrologic Modeling

    Science.gov (United States)

    Spruce, J.; Bolten, J. D.; Srinivasan, R.

    2017-12-01

    This presentation discusses research to develop Land Use Land Cover (LULC) maps for the Lower Mekong Basin (LMB). Funded by a NASA ROSES Disasters grant, the main objective was to produce updated LULC maps to aid the Mekong River Commission's (MRC's) Soil and Water Assessment Tool (SWAT) hydrologic model. In producing needed LULC maps, temporally processed MODIS monthly NDVI data for 2010 were used as the primary data source for classifying regionally prominent forest and agricultural types. The MODIS NDVI data was derived from processing MOD09 and MYD09 8-day reflectance data with the Time Series Product Tool, a custom software package. Circa 2010 Landsat multispectral data from the dry season were processed into top of atmosphere reflectance mosaics and then classified to derive certain locally common LULC types, such as urban areas and industrial forest plantations. Unsupervised ISODATA clustering was used to derive most LULC classifications. GIS techniques were used to merge MODIS and Landsat classifications into final LULC maps for Sub-Basins (SBs) 1-8 of the LMB. The final LULC maps were produced at 250-meter resolution and delivered to the MRC for use in SWAT modeling for the LMB. A map accuracy assessment was performed for the SB 7 LULC map with 14 classes. This assessment was performed by comparing random locations for sampled LULC types to geospatial reference data such as Landsat RGBs, MODIS NDVI phenologic profiles, high resolution satellite data from Google Map/Earth, and other reference data from the MRC (e.g., crop calendars). LULC accuracy assessment results for SB 7 indicated an overall agreement to reference data of 81% at full scheme specificity. However, by grouping 3 deciduous forest classes into 1 class, the overall agreement improved to 87%. The project enabled updated LULC maps, plus more specific rice types were classified compared to the previous LULC maps. The LULC maps from this project should improve the use of SWAT for modeling

  8. Calibration and validation of the SWAT model for a forested watershed in coastal South Carolina

    Science.gov (United States)

    Devendra M. Amatya; Elizabeth B. Haley; Norman S. Levine; Timothy J. Callahan; Artur Radecki-Pawlik; Manoj K. Jha

    2008-01-01

    Modeling the hydrology of low-gradient coastal watersheds on shallow, poorly drained soils is a challenging task due to the complexities in watershed delineation, runoff generation processes and pathways, flooding, and submergence caused by tropical storms. The objective of the study is to calibrate and validate a GIS-based spatially-distributed hydrologic model, SWAT...

  9. Spatial Mapping of Agricultural Water Productivity Using the SWAT Model

    Science.gov (United States)

    Thokal, Rajesh Tulshiram; Gorantiwar, S. D.; Kothari, Mahesh; Bhakar, S. R.; Nandwana, B. P.

    2015-03-01

    The Sina river basin is facing both episodic and chronic water shortages due to intensive irrigation development. The main objective of this study was to characterize the hydrologic processes of the Sina river basin and assess crop water productivity using the distributed hydrologic model, SWAT. In the simulation year (1998-1999), the inflow to reservoir from upstream side was the major contributor to the reservoir accounting for 92 % of the total required water release for irrigation purpose (119.5 Mm3), while precipitation accounted for 4.1 Mm3. Annual release of water for irrigation was 119.5 Mm3 out of which 54 % water was diverted for irrigation purpose, 26 % was wasted as conveyance loss, average discharge at the command outlet was estimated as 4 % and annual average ground-water recharge coefficient was in the range of 13-17 %. Various scenarios involving water allocation rule were tested with the goal of increasing economic water productivity values in the Sina Irrigation Scheme. Out of those, only most benefited allocation rule is analyzed in this paper. Crop yield varied from 1.98 to 25.9 t/ha, with the majority of the area between 2.14 and 2.78 t/ha. Yield and WP declined significantly in loamy soils of the irrigation command. Crop productivity in the basin was found in the lower range when compared with potential and global values. The findings suggested that there was a potential to improve further. Spatial variations in yield and WP were found to be very high for the crops grown during rabi season, while those were low for the crops grown during kharif season. The crop yields and WP during kharif season were more in the lower reach of the irrigation commands, where loamy soil is more concentrated. Sorghum in both seasons was most profitable. Sorghum fetched net income fivefold that of sunflower, two and half fold of pearl millet and one and half fold of mung beans as far as crop during kharif season were concerned and it fetched fourfold that of

  10. Impacts of Irrigation Practices on Groundwater Recharge in Mississippi Delta Using coupled SWAT-MODFLOW Model

    Science.gov (United States)

    Gao, F.; Feng, G.; Han, M.; Jenkins, J.; Ouyang, Y.

    2017-12-01

    The Lower Mississippi River alluvial plain (refers to as MS Delta), located in the northwest state of Mississippi, is one of the most productive agricultural region in the U.S. The primary crops grown in this region are soybean, corn, cotton, and rice. Approximately 80% water from the alluvial aquifer in MS Delta are withdrawn for irrigation, which makes it the most used aquifer in the State. As a result, groundwater level has declined > 6 m since 1970, which threaten the sustainability of irrigated agriculture in this region. The objectives of this study were to: 1) couple the SWAT and MODFLOW then calibrate and validate the incorporated model outputs for stream flow, groundwater level and evapotranspiration (ET) in MS Delta; 2) simulate the groundwater recharge as affected by a) conventional irrigation scheme, b) no irrigation scheme, c) ET based and soil moisture based full irrigation schedules using all groundwater, and d) ET and soil moisture based full irrigation schedule using different percentages of surface and ground water. Results indicated that the coupled model performed well during the calibration and validation for daily stream flow at three USGS gauge stations. (R2=0.7; Nash-Sutcliffe efficiency (NSE) varied from 0.6 to 0.7; Root Mean Square Error (RMSE) ranged from 20 to 27 m3/s). The values of determination coefficient R2 for groundwater level were 0.95 for calibration and 0.88 for validation, their NSE values were 0.99 and 0.93, respectively. The values of RMSE for groundwater level during the calibration and validation period were 0.51 and 0.59 m. The values of R2, NSE and RMSE between SWAT-MODFLOW simulated actual evapotranspiration (ET) and remote sensing evapotranspiration (ET) were 0.52, 0.51 and 28.1 mm. The simulated total average monthly groundwater recharge had lower values of 19 mm/month in the crop season than 30 mm/month in the crop off-growing season. The SWAT-MODFLOW can be a useful tool for not only simulating the recharge in MS

  11. A generalized methodology for identification of threshold for HRU delineation in SWAT model

    Science.gov (United States)

    M, J.; Sudheer, K.; Chaubey, I.; Raj, C.

    2016-12-01

    The distributed hydrological model, Soil and Water Assessment Tool (SWAT) is a comprehensive hydrologic model widely used for making various decisions. The simulation accuracy of the distributed hydrological model differs due to the mechanism involved in the subdivision of the watershed. Soil and Water Assessment Tool (SWAT) considers sub-dividing the watershed and the sub-basins into small computing units known as 'hydrologic response units (HRU). The delineation of HRU is done based on unique combinations of land use, soil types, and slope within the sub-watersheds, which are not spatially defined. The computations in SWAT are done at HRU level and are then aggregated up to the sub-basin outlet, which is routed through the stream system. Generally, the HRUs are delineated by considering a threshold percentage of land use, soil and slope are to be given by the modeler to decrease the computation time of the model. The thresholds constrain the minimum area for constructing an HRU. In the current HRU delineation practice in SWAT, the land use, soil and slope of the watershed within a sub-basin, which is less than the predefined threshold, will be surpassed by the dominating land use, soil and slope, and introduce some level of ambiguity in the process simulations in terms of inappropriate representation of the area. But the loss of information due to variation in the threshold values depends highly on the purpose of the study. Therefore this research studies the effects of threshold values of HRU delineation on the hydrological modeling of SWAT on sediment simulations and suggests guidelines for selecting the appropriate threshold values considering the sediment simulation accuracy. The preliminary study was done on Illinois watershed by assigning different thresholds for land use and soil. A general methodology was proposed for identifying an appropriate threshold for HRU delineation in SWAT model that considered computational time and accuracy of the simulation

  12. Evapotranspiration and Precipitation inputs for SWAT model using remotely sensed observations

    Science.gov (United States)

    The ability of numerical models, such as the Soil and Water Assessment Tool (or SWAT), to accurately represent the partition of the water budget and describe sediment loads and other pollutant conditions related to water quality strongly depends on how well spatiotemporal variability in precipitatio...

  13. Hydrologic evaluation of a Mediterranean watershed using the SWAT model with multiple PET estimation methods

    Science.gov (United States)

    The Penman-Monteith method suggested by the Food Agricultural Organization in the Irrigation and drainage paper 56 (FAO-56 P-M) was used to evaluate surface runoff and sediment yield predictions by the Soil and Water Assessment Tool (SWAT) model at the outlet of an experimental watershed in Sicily. ...

  14. Flow forecast by SWAT model and ANN in Pracana basin, Portugal

    NARCIS (Netherlands)

    Demirel, M.C.; Venancio, Anabela; Kahya, Ercan

    2009-01-01

    This study provides a unique opportunity to analyze the issue of flow forecast based on the soil and water assessment tool (SWAT) and artificial neural network (ANN) models. In last two decades, the ANNs have been extensively applied to various water resources system problems. In this study, the

  15. Modeling phosphorus in the Lake Allatoona watershed using SWAT: I. Developing phosphorus parameter values.

    Science.gov (United States)

    Radcliffe, D E; Lin, Z; Risse, L M; Romeis, J J; Jackson, C R

    2009-01-01

    Lake Allatoona is a large reservoir north of Atlanta, GA, that drains an area of about 2870 km2 scheduled for a phosphorus (P) total maximum daily load (TMDL). The Soil and Water Assessment Tool (SWAT) model has been widely used for watershed-scale modeling of P, but there is little guidance on how to estimate P-related parameters, especially those related to in-stream P processes. In this paper, methods are demonstrated to individually estimate SWAT soil-related P parameters and to collectively estimate P parameters related to stream processes. Stream related parameters were obtained using the nutrient uptake length concept. In a manner similar to experiments conducted by stream ecologists, a small point source is simulated in a headwater sub-basin of the SWAT models, then the in-stream parameter values are adjusted collectively to get an uptake length of P similar to the values measured in the streams in the region. After adjusting the in-stream parameters, the P uptake length estimated in the simulations ranged from 53 to 149 km compared to uptake lengths measured by ecologists in the region of 11 to 85 km. Once the a priori P-related parameter set was developed, the SWAT models of main tributaries to Lake Allatoona were calibrated for daily transport. Models using SWAT P parameters derived from the methods in this paper outperformed models using default parameter values when predicting total P (TP) concentrations in streams during storm events and TP annual loads to Lake Allatoona.

  16. Analysis of the spatial variation in the parameters of the SWAT model with application in Flanders, Northern Belgium

    Directory of Open Access Journals (Sweden)

    G. Heuvelmans

    2004-01-01

    Full Text Available Operational applications of a hydrological model often require the prediction of stream flow in (future time periods without stream flow observations or in ungauged catchments. Data for a case-specific optimisation of model parameters are not available for such applications, so parameters have to be derived from other catchments or time periods. It has been demonstrated that for applications of the SWAT in Northern Belgium, temporal transfers of the parameters have less influence than spatial transfers on the performance of the model. This study examines the spatial variation in parameter optima in more detail. The aim was to delineate zones wherein model parameters can be transferred without a significant loss of model performance. SWAT was calibrated for 25 catchments that are part of eight larger sub-basins of the Scheldt river basin. Two approaches are discussed for grouping these units in zones with a uniform set of parameters: a single parameter approach considering each parameter separately and a parameter set approach evaluating the parameterisation as a whole. For every catchment, the SWAT model was run with the local parameter optima, with the average parameter values for the entire study region (Flanders, with the zones delineated with the single parameter approach and with the zones obtained by the parameter set approach. Comparison of the model performances of these four parameterisation strategies indicates that both the single parameter and the parameter set zones lead to stream flow predictions that are more accurate than if the entire study region were treated as one single zone. On the other hand, the use of zonal average parameter values results in a considerably worse model fit compared to local parameter optima. Clustering of parameter sets gives a more accurate result than the single parameter approach and is, therefore, the preferred technique for use in the parameterisation of ungauged sub-catchments as part of the

  17. Impacts of manure application on SWAT model outputs in the Xiangxi River watershed

    Science.gov (United States)

    Liu, Ruimin; Wang, Qingrui; Xu, Fei; Men, Cong; Guo, Lijia

    2017-12-01

    SWAT (Soil and Water Assessment Tool) model has been widely used to simulate agricultural non-point source (ANPS) pollution; however, the impacts of livestock manure application on SWAT model outputs have not been well studied. The objective of this study was to investigate the environmental effects of livestock manure application based on the SWAT model in the Xiangxi River watershed, which is one of the largest tributaries of the Three Gorges Reservoir in China. Three newly-built manure databases (NB) were created and applied to different subbasins based on the actual livestock manure discharging amount. The calibration and validation values of SWAT model outputs obtained from the NB manure application and the original mixed (OM) manure were compared. The study results are as follows: (1) The livestock industry of Xingshan County developed quickly between 2005 and 2015. The downstream of the Xiangxi River (Huangliang, Shuiyuesi and Xiakou) had the largest livestock amount, and largely accounted for manure, total nitrogen (TN) and total phosphorus (TP) production (>50%). (2) The NB manure application resulted in less phosphorus pollution (1686.35 kg for ORGP and 31.70 kg for MINP) than the OM manure application. Compared with the upstream, the downstream was influenced more by the manure application. (3) The SWAT results obtained from the NB manure had a better calibration and validation values than those from the OM manure. For ORGP, R2 and NSE values were 0.77 and 0.65 for the NB manure calibration; and the same values for the OM manure were 0.72 and 0.61, respectively. For MINP, R2 values were 0.65 and 0.62 for the NB manure and the OM manure, and the NSE values were 0.60 and 0.58, respectively. The results indicated that the built-in fertilizer database in SWAT has its limitation because it is set up for the simulation in the USA. Thus, when livestock manure is considered in a SWAT simulation, a newly built fertilizer database needs to be set up to represent

  18. Analisis Debit Sungai Dengan Menggunakan Model SWAT pada DAS Cipasauran, Banten

    Directory of Open Access Journals (Sweden)

    Maulana Ibrahim Rau

    2015-10-01

    Full Text Available Total water demand at non industrial and industrial region in Cilegon is increasing. With its water production capacity of 2,000 l/s, PT Krakatau Tirta Industri cannot fulfill the amount number of demand from the industrial and domestic sectors at Cilegon. To cover the shortage of water supply of ±600 l/s, PT KTI requires taking water from Cipasauran Watershed. The objective of this study was to analyze river discharge of Cipasauran Watershed using SWAT model. Input data such as soil characteristics, climate data, landuse, and hydrology data at the area of the watershed were gathered and put at the data input file. In SWAT simulation, 4 processes were done, i.e. watershed delineation, hydrological response unit (HRU forming, data process and SWAT simulation, and visualization process. The result showed that the daily and monthly calibration process crossed 84% and 83% with the 95PPU area, with daily and monthly p-factor value of 0.84 and 0.83. Thus, calibrated model result was valid, though R2 and NS value were not satisfied. Using the validated SWAT model, the daily discharge in Cipasauran Watershed was about 0 - 3.309 m3/s, whereas the monthly discharge was 0.648 - 3.266m3/s. This showed that daily and monthly PT KTI’s water demand of 0.6 m3/s were fulfilled about 98.22% and 100%. Within the future time, the SWAT model could be potentially used as an assessment for predictive scenarios. However, to gain optimum results, well-observed and precise data is highly required, especially for such calibrations and validations.

  19. A SWAT model validation of nested-scale contemporaneous stream flow, suspended sediment and nutrients from a multiple-land-use watershed of the central USA.

    Science.gov (United States)

    Zeiger, Sean J; Hubbart, Jason A

    2016-12-01

    There is an ongoing need to validate the accuracy of predictive model simulated pollutant yields, particularly from multiple-land-use (i.e. forested, agricultural, and urban) watersheds. However, there are seldom sufficient observed data sets available that supply requisite spatial and temporal resolution and coupled multi-parameter constituents for rigorous model performance assessment. Four years of hydroclimate and water quality data were used to validate SWAT model estimates of monthly stream flow, suspended sediment, total phosphorus, nitrate, nitrite, ammonium, and total inorganic nitrogen from 5 nested-scale gauging sites located in a multiple-land-use watershed of the central USA. The uncalibrated SWAT model satisfactorily simulated monthly stream flow with Nash-Sutcliffe efficiency (NSE) values ranging from 0.50 near the headwaters, to 0.75 near the watershed outlet. However, the uncalibrated model did not accurately simulate monthly sediment, total phosphorus, nitrate, nitrite, ammonium, and total inorganic nitrogen with NSE valuesSWAT model to multiple gauging sites within the watershed improved estimates of monthly stream flow (NSE=0.83), sediment (NSE=0.78), total phosphorus (NSE=0.81), nitrate (NSE=0.90), and total inorganic nitrogen (NSE=0.86). However, NSE values were model performance decreased for sediment, nitrate, and total inorganic nitrogen during the validation period with NSE valuesSWAT model to multiple gauging sites and provide guidance to SWAT model (or similar models) users wishing to improve model performance at multiple scales. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. SWAT2: The improved SWAT code system by incorporating the continuous energy Monte Carlo code MVP

    International Nuclear Information System (INIS)

    Mochizuki, Hiroki; Suyama, Kenya; Okuno, Hiroshi

    2003-01-01

    SWAT is a code system, which performs the burnup calculation by the combination of the neutronics calculation code, SRAC95 and the one group burnup calculation code, ORIGEN2.1. The SWAT code system can deal with the cell geometry in SRAC95. However, a precise treatment of resonance absorptions by the SRAC95 code using the ultra-fine group cross section library is not directly applicable to two- or three-dimensional geometry models, because of restrictions in SRAC95. To overcome this problem, SWAT2 which newly introduced the continuous energy Monte Carlo code, MVP into SWAT was developed. Thereby, the burnup calculation by the continuous energy in any geometry became possible. Moreover, using the 147 group cross section library called SWAT library, the reactions which are not dealt with by SRAC95 and MVP can be treated. OECD/NEA burnup credit criticality safety benchmark problems Phase-IB (PWR, a single pin cell model) and Phase-IIIB (BWR, fuel assembly model) were calculated as a verification of SWAT2, and the results were compared with the average values of calculation results of burnup calculation code of each organization. Through two benchmark problems, it was confirmed that SWAT2 was applicable to the burnup calculation of the complicated geometry. (author)

  1. A simple rule based model for scheduling farm management operations in SWAT

    Science.gov (United States)

    Schürz, Christoph; Mehdi, Bano; Schulz, Karsten

    2016-04-01

    For many interdisciplinary questions at the watershed scale, the Soil and Water Assessment Tool (SWAT; Arnold et al., 1998) has become an accepted and widely used tool. Despite its flexibility, the model is highly demanding when it comes to input data. At SWAT's core the water balance and the modeled nutrient cycles are plant growth driven (implemented with the EPIC crop growth model). Therefore, land use and crop data with high spatial and thematic resolution, as well as detailed information on cultivation and farm management practices are required. For many applications of the model however, these data are unavailable. In order to meet these requirements, SWAT offers the option to trigger scheduled farm management operations by applying the Potential Heat Unit (PHU) concept. The PHU concept solely takes into account the accumulation of daily mean temperature for management scheduling. Hence, it contradicts several farming strategies that take place in reality; such as: i) Planting and harvesting dates are set much too early or too late, as the PHU concept is strongly sensitivity to inter-annual temperature fluctuations; ii) The timing of fertilizer application, in SWAT this often occurs simultaneously on the same date in in each field; iii) and can also coincide with precipitation events. Particularly, the latter two can lead to strong peaks in modeled nutrient loads. To cope with these shortcomings we propose a simple rule based model (RBM) to schedule management operations according to realistic farmer management practices in SWAT. The RBM involves simple strategies requiring only data that are input into the SWAT model initially, such as temperature and precipitation data. The user provides boundaries of time periods for operation schedules to take place for all crops in the model. These data are readily available from the literature or from crop variety trials. The RBM applies the dates by complying with the following rules: i) Operations scheduled in the

  2. SWAT Model Prediction of Phosphorus Loading in a South Carolina Karst Watershed with a Downstream Embayment

    Science.gov (United States)

    Devendra M. Amatya; Manoj K. Jha; Thomas M. Williams; Amy E. Edwards; Daniel R.. Hitchcock

    2013-01-01

    The SWAT model was used to predict total phosphorus (TP) loadings for a 1555-ha karst watershed—Chapel Branch Creek (CBC)—which drains to a lake via a reservoir-like embayment (R-E). The model was first tested for monthly streamflow predictions from tributaries draining three potential source areas as well as the downstream R-E, followed by TP loadings using data...

  3. A multi-objective approach to improve SWAT model calibration in alpine catchments

    Science.gov (United States)

    Tuo, Ye; Marcolini, Giorgia; Disse, Markus; Chiogna, Gabriele

    2018-04-01

    Multi-objective hydrological model calibration can represent a valuable solution to reduce model equifinality and parameter uncertainty. The Soil and Water Assessment Tool (SWAT) model is widely applied to investigate water quality and water management issues in alpine catchments. However, the model calibration is generally based on discharge records only, and most of the previous studies have defined a unique set of snow parameters for an entire basin. Only a few studies have considered snow observations to validate model results or have taken into account the possible variability of snow parameters for different subbasins. This work presents and compares three possible calibration approaches. The first two procedures are single-objective calibration procedures, for which all parameters of the SWAT model were calibrated according to river discharge alone. Procedures I and II differ from each other by the assumption used to define snow parameters: The first approach assigned a unique set of snow parameters to the entire basin, whereas the second approach assigned different subbasin-specific sets of snow parameters to each subbasin. The third procedure is a multi-objective calibration, in which we considered snow water equivalent (SWE) information at two different spatial scales (i.e. subbasin and elevation band), in addition to discharge measurements. We tested these approaches in the Upper Adige river basin where a dense network of snow depth measurement stations is available. Only the set of parameters obtained with this multi-objective procedure provided an acceptable prediction of both river discharge and SWE. These findings offer the large community of SWAT users a strategy to improve SWAT modeling in alpine catchments.

  4. Adapting SWAT hillslope erosion model to predict sediment concentrations and yields in large Basins.

    Science.gov (United States)

    Vigiak, Olga; Malagó, Anna; Bouraoui, Fayçal; Vanmaercke, Matthias; Poesen, Jean

    2015-12-15

    The Soil and Water Assessment Tool (SWAT) is used worldwide for water quality assessment and planning. This paper aimed to assess and adapt SWAT hillslope sediment yield model (Modified Universal Soil Loss Equation, MUSLE) for applications in large basins, i.e. when spatial data is coarse and model units are large; and to develop a robust sediment calibration method for large regions. The Upper Danube Basin (132,000km(2)) was used as case study representative of large European Basins. The MUSLE was modified to reduce sensitivity of sediment yields to the Hydrologic Response Unit (HRU) size, and to identify appropriate algorithms for estimating hillslope length (L) and slope-length factor (LS). HRUs gross erosion was broadly calibrated against plot data and soil erosion map estimates. Next, mean annual SWAT suspended sediment concentrations (SSC, mg/L) were calibrated and validated against SSC data at 55 gauging stations (622 station-years). SWAT annual specific sediment yields in subbasin reaches (RSSY, t/km(2)/year) were compared to yields measured at 33 gauging stations (87station-years). The best SWAT configuration combined a MUSLE equation modified by the introduction of a threshold area of 0.01km(2) where L and LS were estimated with flow accumulation algorithms. For this configuration, the SSC residual interquartile was less than +/-15mg/L both for the calibration (1995-2004) and the validation (2005-2009) periods. The mean SSC percent bias for 1995-2009 was 24%. RSSY residual interquartile was within +/-10t/km(2)/year, with a mean RSSY percent bias of 12%. Residuals showed no bias with respect to drainage area, slope, or spatial distribution. The use of multiple data types at multiple sites enabled robust simulation of sediment concentrations and yields of the region. The MUSLE modifications are recommended for use in large basins. Based on SWAT simulations, we present a sediment budget for the Upper Danube Basin. Copyright © 2015. Published by Elsevier B.V.

  5. Modeling nitrate-nitrogen load reduction strategies for the des moines river, iowa using SWAT

    Science.gov (United States)

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

    2009-01-01

    The Des Moines River that drains a watershed of 16,175 km2 in portions of Iowa and Minnesota is impaired for nitrate-nitrogen (nitrate) due to concentrations that exceed regulatory limits for public water supplies. The Soil Water Assessment Tool (SWAT) model was used to model streamflow and nitrate loads and evaluate a suite of basin-wide changes and targeting configurations to potentially reduce nitrate loads in the river. The SWAT model comprised 173 subbasins and 2,516 hydrologic response units and included point and nonpoint nitrogen sources. The model was calibrated for an 11-year period and three basin-wide and four targeting strategies were evaluated. Results indicated that nonpoint sources accounted for 95% of the total nitrate export. Reduction in fertilizer applications from 170 to 50 kg/ha achieved the 38% reduction in nitrate loads, exceeding the 34% reduction required. In terms of targeting, the most efficient load reductions occurred when fertilizer applications were reduced in subbasins nearest the watershed outlet. The greatest load reduction for the area of land treated was associated with reducing loads from 55 subbasins with the highest nitrate loads, achieving a 14% reduction in nitrate loads achieved by reducing applications on 30% of the land area. SWAT model results provide much needed guidance on how to begin implementing load reduction strategies most efficiently in the Des Moines River watershed. ?? 2009 Springer Science+Business Media, LLC.

  6. Modeling nitrate-nitrogen load reduction strategies for the Des Moines River, Iowa using SWAT.

    Science.gov (United States)

    Schilling, Keith E; Wolter, Calvin F

    2009-10-01

    The Des Moines River that drains a watershed of 16,175 km(2) in portions of Iowa and Minnesota is impaired for nitrate-nitrogen (nitrate) due to concentrations that exceed regulatory limits for public water supplies. The Soil Water Assessment Tool (SWAT) model was used to model streamflow and nitrate loads and evaluate a suite of basin-wide changes and targeting configurations to potentially reduce nitrate loads in the river. The SWAT model comprised 173 subbasins and 2,516 hydrologic response units and included point and nonpoint nitrogen sources. The model was calibrated for an 11-year period and three basin-wide and four targeting strategies were evaluated. Results indicated that nonpoint sources accounted for 95% of the total nitrate export. Reduction in fertilizer applications from 170 to 50 kg/ha achieved the 38% reduction in nitrate loads, exceeding the 34% reduction required. In terms of targeting, the most efficient load reductions occurred when fertilizer applications were reduced in subbasins nearest the watershed outlet. The greatest load reduction for the area of land treated was associated with reducing loads from 55 subbasins with the highest nitrate loads, achieving a 14% reduction in nitrate loads achieved by reducing applications on 30% of the land area. SWAT model results provide much needed guidance on how to begin implementing load reduction strategies most efficiently in the Des Moines River watershed.

  7. Modeling Agricultural Watersheds with the Soil and Water Assessment Tool (SWAT): Calibration and Validation with a Novel Procedure for Spatially Explicit HRUs.

    Science.gov (United States)

    Teshager, Awoke Dagnew; Gassman, Philip W; Secchi, Silvia; Schoof, Justin T; Misgna, Girmaye

    2016-04-01

    Applications of the Soil and Water Assessment Tool (SWAT) model typically involve delineation of a watershed into subwatersheds/subbasins that are then further subdivided into hydrologic response units (HRUs) which are homogeneous areas of aggregated soil, landuse, and slope and are the smallest modeling units used within the model. In a given standard SWAT application, multiple potential HRUs (farm fields) in a subbasin are usually aggregated into a single HRU feature. In other words, the standard version of the model combines multiple potential HRUs (farm fields) with the same landuse/landcover, soil, and slope, but located at different places of a subbasin (spatially non-unique), and considers them as one HRU. In this study, ArcGIS pre-processing procedures were developed to spatially define a one-to-one match between farm fields and HRUs (spatially unique HRUs) within a subbasin prior to SWAT simulations to facilitate input processing, input/output mapping, and further analysis at the individual farm field level. Model input data such as landuse/landcover (LULC), soil, crop rotation, and other management data were processed through these HRUs. The SWAT model was then calibrated/validated for Raccoon River watershed in Iowa for 2002-2010 and Big Creek River watershed in Illinois for 2000-2003. SWAT was able to replicate annual, monthly, and daily streamflow, as well as sediment, nitrate and mineral phosphorous within recommended accuracy in most cases. The one-to-one match between farm fields and HRUs created and used in this study is a first step in performing LULC change, climate change impact, and other analyses in a more spatially explicit manner.

  8. Estimation of transported pollutant load in Ardila catchment using the SWAT model

    OpenAIRE

    DURÃO, A.; LEITÃO, P.; BRITO, D.; FERNANDES, R.M.; NEVES, R.; MORAIS, M.

    2011-01-01

    Excess of organic matter and nutrients in the water body promotes algae blooms, which can accelerate the eutrophication process, situation often observed in the Ardila river. This river was identified as very polluted and classified as critical for Alqueva-Pedrogão System. The aim of this study was to estimate the transported nutrients load in a transboundary catchment using the SWAT (Soil and Water Assessment Tool) model and to determine the contribution off nutrients load in the entire catc...

  9. Spatial and temporal changes of water quality, and SWAT modeling of Vosvozis river basin, North Greece.

    Science.gov (United States)

    Boskidis, Ioannis; Gikas, Georgios D; Pisinaras, Vassilios; Tsihrintzis, Vassilios A

    2010-09-01

    The results of an investigation of the quantitative and qualitative characteristics of Vosvozis river in Northern Greece is presented. For the purposes of this study, three gaging stations were installed along Vosvozis river, where water quantity and quality measurements were conducted for the period August 2005 to November 2006. Water discharge, temperature, pH, dissolved oxygen (DO) and electrical conductivity (EC) were measured in situ using appropriate equipment. The collected water samples were analyzed in the laboratory for the determination of nitrate, nitrite and ammonium nitrogen, total Kjeldalh nitrogen (TKN), orthophosphate (OP), total phosphorus (TP), COD, and BOD. Agricultural diffuse sources provided the major source of nitrate nitrogen loads during the wet period. During the dry period (from June to October), the major nutrient (N, P) and COD, BOD sources were point sources. The trophic status of Vosvozis river during the monitoring period was determined as eutrophic, based on Dodds classification scheme. Moreover, the SWAT model was used to simulate hydrographs and nutrient loads. SWAT was validated with the measured data. Predicted hydrographs and pollutographs were plotted against observed values and showed good agreement. The validated model was used to test eight alternative scenarios concerning different cropping management approaches. The results of these scenarios indicate that nonpoint source pollution is the prevailing type of pollution in the study area. The SWAT model was found to satisfactorily simulate processes in ephemeral river basins and is an effective tool in water resources management.

  10. Assessment of soil erosion risk in Komering watershed, South Sumatera, using SWAT model

    Science.gov (United States)

    Salsabilla, A.; Kusratmoko, E.

    2017-07-01

    Changes in land use watershed led to environmental degradation. Estimated loss of soil erosion is often difficult due to some factors such as topography, land use, climate and human activities. This study aims to predict soil erosion hazard and sediment yield using the Soil and Water Assessment Tools (SWAT) hydrological model. The SWAT was chosen because it can simulate the model with limited data. The study area is Komering watershed (806,001 Ha) in South Sumatera Province. There are two factors land management intervention: 1) land with agriculture, and 2) land with cultivation. These factors selected in accordance with the regulations of spatial plan area. Application of the SWAT demonstrated that the model can predict surface runoff, soil erosion loss and sediment yield. The erosion risk for each watershed can be classified and predicted its changes based on the scenarios which arranged. In this paper, we also discussed the relationship between the distribution of erosion risk and watershed's characteristics in a spatial perspective.

  11. Comparison of performance of tile drainage routines in SWAT 2009 and 2012 in an extensively tile-drained watershed in the Midwest

    Directory of Open Access Journals (Sweden)

    T. Guo

    2018-01-01

    Full Text Available Subsurface tile drainage systems are widely used in agricultural watersheds in the Midwestern US and enable the Midwest area to become highly productive agricultural lands, but can also create environmental problems, for example nitrate-N contamination associated with drainage waters. The Soil and Water Assessment Tool (SWAT has been used to model watersheds with tile drainage. SWAT2012 revisions 615 and 645 provide new tile drainage routines. However, few studies have used these revisions to study tile drainage impacts at both field and watershed scales. Moreover, SWAT2012 revision 645 improved the soil moisture based curve number calculation method, which has not been fully tested. This study used long-term (1991–2003 field site and river station data from the Little Vermilion River (LVR watershed to evaluate performance of tile drainage routines in SWAT2009 revision 528 (the old routine and SWAT2012 revisions 615 and 645 (the new routine. Both the old and new routines provided reasonable but unsatisfactory (NSE  <  0.5 uncalibrated flow and nitrate loss results for a mildly sloped watershed with low runoff. The calibrated monthly tile flow, surface flow, nitrate-N in tile and surface flow, sediment and annual corn and soybean yield results from SWAT with the old and new tile drainage routines were compared with observed values. Generally, the new routine provided acceptable simulated tile flow (NSE  =  0.48–0.65 and nitrate in tile flow (NSE  =  0.48–0.68 for field sites with random pattern tile and constant tile spacing, while the old routine simulated tile flow and nitrate in tile flow results for the field site with constant tile spacing were unacceptable (NSE  =  0.00–0.32 and −0.29–0.06, respectively. The new modified curve number calculation method in revision 645 (NSE  =  0.50–0.81 better simulated surface runoff than revision 615 (NSE  =  −0.11–0.49. The calibration

  12. Comparison of performance of tile drainage routines in SWAT 2009 and 2012 in an extensively tile-drained watershed in the Midwest

    Science.gov (United States)

    Guo, Tian; Gitau, Margaret; Merwade, Venkatesh; Arnold, Jeffrey; Srinivasan, Raghavan; Hirschi, Michael; Engel, Bernard

    2018-01-01

    Subsurface tile drainage systems are widely used in agricultural watersheds in the Midwestern US and enable the Midwest area to become highly productive agricultural lands, but can also create environmental problems, for example nitrate-N contamination associated with drainage waters. The Soil and Water Assessment Tool (SWAT) has been used to model watersheds with tile drainage. SWAT2012 revisions 615 and 645 provide new tile drainage routines. However, few studies have used these revisions to study tile drainage impacts at both field and watershed scales. Moreover, SWAT2012 revision 645 improved the soil moisture based curve number calculation method, which has not been fully tested. This study used long-term (1991-2003) field site and river station data from the Little Vermilion River (LVR) watershed to evaluate performance of tile drainage routines in SWAT2009 revision 528 (the old routine) and SWAT2012 revisions 615 and 645 (the new routine). Both the old and new routines provided reasonable but unsatisfactory (NSE runoff. The calibrated monthly tile flow, surface flow, nitrate-N in tile and surface flow, sediment and annual corn and soybean yield results from SWAT with the old and new tile drainage routines were compared with observed values. Generally, the new routine provided acceptable simulated tile flow (NSE = 0.48-0.65) and nitrate in tile flow (NSE = 0.48-0.68) for field sites with random pattern tile and constant tile spacing, while the old routine simulated tile flow and nitrate in tile flow results for the field site with constant tile spacing were unacceptable (NSE = 0.00-0.32 and -0.29-0.06, respectively). The new modified curve number calculation method in revision 645 (NSE = 0.50-0.81) better simulated surface runoff than revision 615 (NSE = -0.11-0.49). The calibration provided reasonable parameter sets for the old and new routines in the LVR watershed, and the validation results showed that the new routine has the potential to accurately

  13. Assessment of land-use change on streamflow using GIS, remote sensing and a physically-based model, SWAT

    Directory of Open Access Journals (Sweden)

    J. Y. G. Dos Santos

    2014-09-01

    Full Text Available This study aims to assess the impact of the land-use changes between the periods 1967−1974 and 1997−2008 on the streamflow of Tapacurá catchment (northeastern Brazil using the Soil and Water Assessment Tool (SWAT model. The results show that the most sensitive parameters were the baseflow, Manning factor, time of concentration and soil evaporation compensation factor, which affect the catchment hydrology. The model calibration and validation were performed on a monthly basis, and the streamflow simulation showed a good level of accuracy for both periods. The obtained R2 and Nash-Sutcliffe Efficiency values for each period were respectively 0.82 and 0.81 for 1967−1974, and 0.93 and 0.92 for the period 1997−2008. The evaluation of the SWAT model response to the land cover has shown that the mean monthly flow, during the rainy seasons for 1967−1974, decreased when compared to 1997−2008.

  14. Free internet datasets for streamflow modelling using SWAT in the Johor river basin, Malaysia

    Science.gov (United States)

    Tan, M. L.

    2014-02-01

    Streamflow modelling is a mathematical computational approach that represents terrestrial hydrology cycle digitally and is used for water resources assessment. However, such modelling endeavours require a large amount of data. Generally, governmental departments produce and maintain these data sets which make it difficult to obtain this data due to bureaucratic constraints. In some countries, the availability and quality of geospatial and climate datasets remain a critical issue due to many factors such as lacking of ground station, expertise, technology, financial support and war time. To overcome this problem, this research used public domain datasets from the Internet as "input" to a streamflow model. The intention is simulate daily and monthly streamflow of the Johor River Basin in Malaysia. The model used is the Soil and Water Assessment Tool (SWAT). As input free data including a digital elevation model (DEM), land use information, soil and climate data were used. The model was validated by in-situ streamflow information obtained from Rantau Panjang station for the year 2006. The coefficient of determination and Nash-Sutcliffe efficiency were 0.35/0.02 for daily simulated streamflow and 0.92/0.21 for monthly simulated streamflow, respectively. The results show that free data can provide a better simulation at a monthly scale compared to a daily basis in a tropical region. A sensitivity analysis and calibration procedure should be conducted in order to maximize the "goodness-of-fit" between simulated and observed streamflow. The application of Internet datasets promises an acceptable performance of streamflow modelling. This research demonstrates that public domain data is suitable for streamflow modelling in a tropical river basin within acceptable accuracy.

  15. Free internet datasets for streamflow modelling using SWAT in the Johor river basin, Malaysia

    International Nuclear Information System (INIS)

    Tan, M L

    2014-01-01

    Streamflow modelling is a mathematical computational approach that represents terrestrial hydrology cycle digitally and is used for water resources assessment. However, such modelling endeavours require a large amount of data. Generally, governmental departments produce and maintain these data sets which make it difficult to obtain this data due to bureaucratic constraints. In some countries, the availability and quality of geospatial and climate datasets remain a critical issue due to many factors such as lacking of ground station, expertise, technology, financial support and war time. To overcome this problem, this research used public domain datasets from the Internet as ''input'' to a streamflow model. The intention is simulate daily and monthly streamflow of the Johor River Basin in Malaysia. The model used is the Soil and Water Assessment Tool (SWAT). As input free data including a digital elevation model (DEM), land use information, soil and climate data were used. The model was validated by in-situ streamflow information obtained from Rantau Panjang station for the year 2006. The coefficient of determination and Nash-Sutcliffe efficiency were 0.35/0.02 for daily simulated streamflow and 0.92/0.21 for monthly simulated streamflow, respectively. The results show that free data can provide a better simulation at a monthly scale compared to a daily basis in a tropical region. A sensitivity analysis and calibration procedure should be conducted in order to maximize the ''goodness-of-fit'' between simulated and observed streamflow. The application of Internet datasets promises an acceptable performance of streamflow modelling. This research demonstrates that public domain data is suitable for streamflow modelling in a tropical river basin within acceptable accuracy

  16. Assessment of Climate Change Impacts on Water Resources in Zarrinehrud Basin Using SWAT Model

    Directory of Open Access Journals (Sweden)

    B. Mansouri

    2015-06-01

    Full Text Available This paper evaluate impacts of climate change on temperature, rainfall and runoff in the future Using statistical model, LARS-WG, and conceptual hydrological model, SWAT. In order to the Zarrinehrud river basin, as the biggest catchment of the Lake Urmia basin was selected as a case study. At first, for the generation of future weather data in the basin, LARS-WG model was calibrated using meteorological data and then 14 models of AOGCM were applied and results of these models were downscaled using LARS-WG model in 6 synoptic stations for period of 2015 to 2030. SWAT model was used for evaluation of climate change impacts on runoff in the basin. In order to, the model was calibrated and validated using 6 gauging stations for period of 1987-2007 and the value of R2 was between 0.49 and 0.71 for calibration and between 0.54 and 0.77 for validation. Then by introducing average of downscaled results of AOGCM models to the SWAT, runoff changes of the basin were simulated during 2015-2030. Average of results of LARS-WG model indicated that the monthly mean of minimum and maximum temperatures will increase compared to the baseline period. Also monthly average of precipitation will decrease in spring season but will increase in summer and autumn. The results showed that in addition to the amount of precipitation, its pattern will change in the future period, too. The results of runoff simulation showed that the amount of inflow to the Zarrinehrud reservoir will reduce 28.4 percent compared to the baseline period.

  17. Trail Creek II: Modeling Flow and E. Coli Concentrations in a Small Urban Stream using SWAT

    Science.gov (United States)

    Radcliffe, D. E.; Saintil, T.

    2017-12-01

    Pathogens are one of the leading causes of stream and river impairment in the State of Georgia. The common presence of fecal bacteria is driven by several factors including rapid population growth stressing pre-existing and ageing infrastructure, urbanization and poor planning, increase percent imperviousness, urban runoff, municipal discharges, sewage, pet/wildlife waste and leaky septic tanks. The Trail Creek watershed, located in Athens-Clarke County, Georgia covers about 33 km2. Stream segments within Trail Creek violate the GA standard due to high levels of fecal coliform bacteria. In this study, the Soil and Water Assessment Tool (SWAT) modeling software was used to predict E. coli bacteria concentrations during baseflow and stormflow. Census data from the county was used for human and animal population estimates and the Fecal Indicator Tool to generate the number of colony forming units of E. Coli for each source. The model was calibrated at a daily time step with one year of monitored streamflow and E. coli bacteria data using SWAT-CUP and the SUFI2 algorithm. To simulate leaking sewer lines, we added point sources in the five subbasins in the SWAT model with the greatest length of sewer line within 50 m of the stream. The flow in the point sources were set to 5% of the stream flow and the bacteria count set to that of raw sewage (30,000 cfu/100 mL). The calibrated model showed that the average load during 2003-2013 at the watershed outlet was 13 million cfu per month. Using the calibrated model, we simulated scenarios that assumed leaking sewers were repaired in one of the five subbasins with point sources. The reduction ranged from 10 to 46%, with the largest reduction in subbasin in the downtown area. Future modeling work will focus on the use of green infrastructure to address sources of bacteria.

  18. Ethiopian Central Rift Valley basin hydrologic modelling using HEC-HMS and ArcSWAT

    Science.gov (United States)

    Pascual-Ferrer, Jordi; Candela, Lucila; Pérez-Foguet, Agustí

    2013-04-01

    An Integrated Water Resources Management (IWRM) shall be applied to achieve a sustainable development, to increase population incomes without affecting lives of those who are highly dependent on the environment. First step should be to understand water dynamics at basin level, starting by modeling the basin water resources. For model implementation, a large number of data and parameters are required, but those are not always available, especially in some developing countries where different sources may have different data, there is lack of information on data collection, etc. The Ethiopian Central Rift Valley (CRV) is an endorheic basin covering an area of approximately 10,000 km2. For the period 1996-2005, the average annual volume of rainfall accounted for 9.1 Mm3, and evapotranspiration for 8 Mm3 (Jansen et al., 2007). From the environmental point of view, basin ecosystems are endangered due to human activities. Also, poverty is widespread all over the basin, with population mainly living from agriculture on a subsistence economy. Hence, there is an urgent need to set an IWRM, but datasets required for water dynamics simulation are not too reliable. In order to reduce uncertainty of numerical simulation, two semi-distributed open software hydrologic models were implemented: HEC-HMS and ArcSWAT. HEC-HMS was developed by the United States Army Corps of Engineers (USACoE) Hydrologic Engineering Center (HEC) to run precipitation-runoff simulations for a variety of applications in dendritic watershed systems. ArcSWAT includes the SWAT (Soil and Water Assessment Tool, Arnold et al., 1998) model developed for the USDA Agricultural Research Service into ArcGIS (ESRI®). SWAT was developed to assess the impact of land management practices on large complex watersheds with varying soils, land use and management conditions over long periods of time (Neitsch et al., 2005). According to this, ArcSWAT would be the best option for IWRM implementation in the basin. However

  19. SWAT meta-modeling as support of the management scenario analysis in large watersheds.

    Science.gov (United States)

    Azzellino, A; Çevirgen, S; Giupponi, C; Parati, P; Ragusa, F; Salvetti, R

    2015-01-01

    In the last two decades, numerous models and modeling techniques have been developed to simulate nonpoint source pollution effects. Most models simulate the hydrological, chemical, and physical processes involved in the entrainment and transport of sediment, nutrients, and pesticides. Very often these models require a distributed modeling approach and are limited in scope by the requirement of homogeneity and by the need to manipulate extensive data sets. Physically based models are extensively used in this field as a decision support for managing the nonpoint source emissions. A common characteristic of this type of model is a demanding input of several state variables that makes the calibration and effort-costing in implementing any simulation scenario more difficult. In this study the USDA Soil and Water Assessment Tool (SWAT) was used to model the Venice Lagoon Watershed (VLW), Northern Italy. A Multi-Layer Perceptron (MLP) network was trained on SWAT simulations and used as a meta-model for scenario analysis. The MLP meta-model was successfully trained and showed an overall accuracy higher than 70% both on the training and on the evaluation set, allowing a significant simplification in conducting scenario analysis.

  20. Modelling of hydrologic processes and potential response to climate change through the use of a multisite SWAT

    DEFF Research Database (Denmark)

    Gül, G.O.; Rosbjerg, Dan

    2010-01-01

    Hydrologic models that use components for integrated modelling of surface water and groundwater systems help conveniently simulate the dynamically linked hydrologic and hydraulic processes that govern flow conditions in watersheds. The Soil and Water Assessment Tool (SWAT) is one such model...... that allows continuous simulations over long time periods in the land phase of the hydrologic cycle by incorporating surface water and groundwater interactions. This study provides a verified structure for the SWAT to evaluate existing flow regimes in a small-sized catchment in Denmark and examines a simple...... simulation to help quantify the effects of climate change on regional water quantities. SWAT can be regarded among the alternative hydrologic simulation tools applicable for catchments with similar characteristics and of similar sizes in Denmark. However, the modellers would be required to determine a proper...

  1. Advancing representation of hydrologic processes in the Soil and Water Assessment Tool (SWAT) through integration of the TOPographic MODEL (TOPMODEL) features

    Science.gov (United States)

    Chen, J.; Wu, Y.

    2012-01-01

    This paper presents a study of the integration of the Soil and Water Assessment Tool (SWAT) model and the TOPographic MODEL (TOPMODEL) features for enhancing the physical representation of hydrologic processes. In SWAT, four hydrologic processes, which are surface runoff, baseflow, groundwater re-evaporation and deep aquifer percolation, are modeled by using a group of empirical equations. The empirical equations usually constrain the simulation capability of relevant processes. To replace these equations and to model the influences of topography and water table variation on streamflow generation, the TOPMODEL features are integrated into SWAT, and a new model, the so-called SWAT-TOP, is developed. In the new model, the process of deep aquifer percolation is removed, the concept of groundwater re-evaporation is refined, and the processes of surface runoff and baseflow are remodeled. Consequently, three parameters in SWAT are discarded, and two new parameters to reflect the TOPMODEL features are introduced. SWAT-TOP and SWAT are applied to the East River basin in South China, and the results reveal that, compared with SWAT, the new model can provide a more reasonable simulation of the hydrologic processes of surface runoff, groundwater re-evaporation, and baseflow. This study evidences that an established hydrologic model can be further improved by integrating the features of another model, which is a possible way to enhance our understanding of the workings of catchments.

  2. Modification of SWAT model for simulation of organic matter in Korean watersheds.

    Science.gov (United States)

    Jang, Jae-Ho; Jung, Kwang-Wook; Gyeong Yoon, Chun

    2012-01-01

    The focus of water quality modeling of Korean streams needs to be shifted from dissolved oxygen to algae or organic matter. In particular, the structure of water quality models should be modified to simulate the biochemical oxygen demand (BOD), which is a key factor in calculating total maximum daily loads (TMDLs) in Korea, using 5-day BOD determined in the laboratory (Bottle BOD(5)). Considering the limitations in simulating organic matter under domestic conditions, we attempted to model total organic carbon (TOC) as well as BOD by using a watershed model. For this purpose, the Soil and Water Assessment Tool (SWAT) model was modified and extended to achieve better correspondence between the measured and simulated BOD and TOC concentrations. For simulated BOD in the period 2004-2008, the Nash-Sutcliffe model efficiency coefficient increased from a value of -2.54 to 0.61. Another indicator of organic matter, namely, the simulated TOC concentration showed that the modified SWAT adequately reflected the observed values. The improved model can be used to predict organic matter and hence, may be a potential decision-making tool for TMDLs. However, it needs further testing for longer simulation periods and other catchments.

  3. Evaluating the Efficiency of a Multi-core Aware Multi-objective Optimization Tool for Calibrating the SWAT Model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Izaurralde, R. C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zong, Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhao, K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thomson, A. M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2012-08-20

    The efficiency of calibrating physically-based complex hydrologic models is a major concern in the application of those models to understand and manage natural and human activities that affect watershed systems. In this study, we developed a multi-core aware multi-objective evolutionary optimization algorithm (MAMEOA) to improve the efficiency of calibrating a worldwide used watershed model (Soil and Water Assessment Tool (SWAT)). The test results show that MAMEOA can save about 1-9%, 26-51%, and 39-56% time consumed by calibrating SWAT as compared with sequential method by using dual-core, quad-core, and eight-core machines, respectively. Potential and limitations of MAMEOA for calibrating SWAT are discussed. MAMEOA is open source software.

  4. Incorporating rainfall uncertainty in a SWAT model: the river Zenne basin (Belgium) case study

    Science.gov (United States)

    Tolessa Leta, Olkeba; Nossent, Jiri; van Griensven, Ann; Bauwens, Willy

    2013-04-01

    The European Union Water Framework Directive (EU-WFD) called its member countries to achieve a good ecological status for all inland and coastal water bodies by 2015. According to recent studies, the river Zenne (Belgium) is far from this objective. Therefore, an interuniversity and multidisciplinary project "Towards a Good Ecological Status in the river Zenne (GESZ)" was launched to evaluate the effects of wastewater management plans on the river. In this project, different models have been developed and integrated using the Open Modelling Interface (OpenMI). The hydrologic, semi-distributed Soil and Water Assessment Tool (SWAT) is hereby used as one of the model components in the integrated modelling chain in order to model the upland catchment processes. The assessment of the uncertainty of SWAT is an essential aspect of the decision making process, in order to design robust management strategies that take the predicted uncertainties into account. Model uncertainty stems from the uncertainties on the model parameters, the input data (e.g, rainfall), the calibration data (e.g., stream flows) and on the model structure itself. The objective of this paper is to assess the first three sources of uncertainty in a SWAT model of the river Zenne basin. For the assessment of rainfall measurement uncertainty, first, we identified independent rainfall periods, based on the daily precipitation and stream flow observations and using the Water Engineering Time Series PROcessing tool (WETSPRO). Secondly, we assigned a rainfall multiplier parameter for each of the independent rainfall periods, which serves as a multiplicative input error corruption. Finally, we treated these multipliers as latent parameters in the model optimization and uncertainty analysis (UA). For parameter uncertainty assessment, due to the high number of parameters of the SWAT model, first, we screened out its most sensitive parameters using the Latin Hypercube One-factor-At-a-Time (LH-OAT) technique

  5. Management-oriented sensitivity analysis for pesticide transport in watershed-scale water quality modeling using SWAT

    International Nuclear Information System (INIS)

    Luo Yuzhou; Zhang Minghua

    2009-01-01

    The Soil and Water Assessment Tool (SWAT) was calibrated for hydrology conditions in an agricultural watershed of Orestimba Creek, California, and applied to simulate fate and transport of two organophosphate pesticides chlorpyrifos and diazinon. The model showed capability in evaluating pesticide fate and transport processes in agricultural fields and instream network. Management-oriented sensitivity analysis was conducted by applied stochastic SWAT simulations for pesticide distribution. Results of sensitivity analysis identified the governing processes in pesticide outputs as surface runoff, soil erosion, and sedimentation in the study area. By incorporating sensitive parameters in pesticide transport simulation, effects of structural best management practices (BMPs) in improving surface water quality were demonstrated by SWAT modeling. This study also recommends conservation practices designed to reduce field yield and in-stream transport capacity of sediment, such as filter strip, grassed waterway, crop residue management, and tailwater pond to be implemented in the Orestimba Creek watershed. - Selected structural BMPs are recommended for reducing loads of OP pesticides.

  6. Management-oriented sensitivity analysis for pesticide transport in watershed-scale water quality modeling using SWAT

    Energy Technology Data Exchange (ETDEWEB)

    Luo Yuzhou [University of California, Davis, CA 95616 (United States); Wenzhou Medical College, Wenzhou 325035 (China); Zhang Minghua, E-mail: mhzhang@ucdavis.ed [University of California, Davis, CA 95616 (United States); Wenzhou Medical College, Wenzhou 325035 (China)

    2009-12-15

    The Soil and Water Assessment Tool (SWAT) was calibrated for hydrology conditions in an agricultural watershed of Orestimba Creek, California, and applied to simulate fate and transport of two organophosphate pesticides chlorpyrifos and diazinon. The model showed capability in evaluating pesticide fate and transport processes in agricultural fields and instream network. Management-oriented sensitivity analysis was conducted by applied stochastic SWAT simulations for pesticide distribution. Results of sensitivity analysis identified the governing processes in pesticide outputs as surface runoff, soil erosion, and sedimentation in the study area. By incorporating sensitive parameters in pesticide transport simulation, effects of structural best management practices (BMPs) in improving surface water quality were demonstrated by SWAT modeling. This study also recommends conservation practices designed to reduce field yield and in-stream transport capacity of sediment, such as filter strip, grassed waterway, crop residue management, and tailwater pond to be implemented in the Orestimba Creek watershed. - Selected structural BMPs are recommended for reducing loads of OP pesticides.

  7. Management-oriented sensitivity analysis for pesticide transport in watershed-scale water quality modeling using SWAT.

    Science.gov (United States)

    Luo, Yuzhou; Zhang, Minghua

    2009-12-01

    The Soil and Water Assessment Tool (SWAT) was calibrated for hydrology conditions in an agricultural watershed of Orestimba Creek, California, and applied to simulate fate and transport of two organophosphate pesticides chlorpyrifos and diazinon. The model showed capability in evaluating pesticide fate and transport processes in agricultural fields and instream network. Management-oriented sensitivity analysis was conducted by applied stochastic SWAT simulations for pesticide distribution. Results of sensitivity analysis identified the governing processes in pesticide outputs as surface runoff, soil erosion, and sedimentation in the study area. By incorporating sensitive parameters in pesticide transport simulation, effects of structural best management practices (BMPs) in improving surface water quality were demonstrated by SWAT modeling. This study also recommends conservation practices designed to reduce field yield and in-stream transport capacity of sediment, such as filter strip, grassed waterway, crop residue management, and tailwater pond to be implemented in the Orestimba Creek watershed.

  8. Development of Web-Based RECESS Model for Estimating Baseflow Using SWAT

    Directory of Open Access Journals (Sweden)

    Gwanjae Lee

    2014-04-01

    Full Text Available Groundwater has received increasing attention as an important strategic water resource for adaptation to climate change. In this regard, the separation of baseflow from streamflow and the analysis of recession curves make a significant contribution to integrated river basin management. The United States Geological Survey (USGS RECESS model adopting the master-recession curve (MRC method can enhance the accuracy with which baseflow may be separated from streamflow, compared to other baseflow-separation schemes that are more limited in their ability to reflect various watershed/aquifer characteristics. The RECESS model has been widely used for the analysis of hydrographs, but the applications using RECESS were only available through Microsoft-Disk Operating System (MS-DOS. Thus, this study aims to develop a web-based RECESS model for easy separation of baseflow from streamflow, with easy applications for ungauged regions. RECESS on the web derived the alpha factor, which is a baseflow recession constant in the Soil Water Assessment Tool (SWAT, and this variable was provided to SWAT as the input. The results showed that the alpha factor estimated from the web-based RECESS model improved the predictions of streamflow and recession. Furthermore, these findings showed that the baseflow characteristics of the ungauged watersheds were influenced by the land use and slope angle of watersheds, as well as by precipitation and streamflow.

  9. Evaluation of the applicability of the SWAT model in an arid piedmont plain oasis.

    Science.gov (United States)

    Wu, Yong; Li, Changyou; Zhang, Chengfu; Shi, Xiaohong; Bourque, Charles P-A; Zhao, Shengnan

    2016-01-01

    Hetao Oasis is located in a typical piedmont alluvial plain bounded by the Langshan Mountain Range in the north, desert in the west, and the Yellow River in the south. Agricultural activities within the oasis significantly impact the hydrological cycle and water quality in downstream locations. The research uses the Soil and Water Assessment Tool (SWAT) for a piedmont plain by defining the watershed boundary as coinciding with the natural mountain ridge, the border between the oasis and the desert, and the Yellow River. The model simulates water discharge with coefficient of determination and a Nash-Sutcliffe model efficiency of 0.78 and 0.62 during model calibration, and 0.75 and 0.69 during model validation, suggesting that delineation of the watershed as carried out in this research is suitable for piedmont plain topography. From the results, the mountains contribute 28.4% to the water discharge at the outlet of the watershed, and water-use efficiency of irrigated water is about 40%, which is consistent with field-based measurements. Methodologies used in delineating watershed boundaries and parameterizing SWAT provide a solid foundation for water balance studies in other regions of the world with similar topography.

  10. Applicability of the SWAT model for hydrologic simulation in Paraopeba river basin, MG

    Directory of Open Access Journals (Sweden)

    Matheus Fonseca Durães

    2011-12-01

    Full Text Available The SWAT model (Soil and Water Assessment Tool was applied for simulating the hydrologic pattern of Paraopeba river basin, in Minas Gerais state, under different land use and occupation scenarios, looking to support basin management actions. The model parameters were calibrated and validated, with respect to the data observed from 1983 to 2005. The basin was assessed at the ‘Porto do Mesquita’ gauging station and change in land use and occupation was based on the annual growth scenarios proposed in the partial report of Paraopeba basin’s master plan. The model was found to be highly sensitive to baseflow, its main calibration variable. Statistical analyses produced a Nash-Sutcliffe coefficient above 0.75, which is considered good and acceptable. The SWAT model provided satisfactory results in simulating hydrologic pattern under different scenarios of land use change, demonstrating that it can be applied for forecasting discharge in the aforesaid basin. The current land use scenario provided a peak discharge simulation of 1250 m³ s-1, while in years 2019 and 2029 peak discharge simulations were 1190 m³ s-1 and 1230 m³ s-1 respectively. The 2019 scenario provided the best results with respect to baseflow increase and peak discharge reduction.

  11. Calibration and validation of the SWAT model for predicting daily ET over irrigated crops in the Texas High Plains using lysimetric data

    Science.gov (United States)

    The Soil Water Assessment Tool (SWAT) is a widely used watershed model for simulating stream flow, overland flow, sediment, pesticide, and bacterial loading in response to management practices. All SWAT processes are directly dependent upon the accurate representation of hydrology. Evapotranspiratio...

  12. Calibration and validation of the SWAT model for predicting daily ET for irrigated crops in the Texas High Plains using lysimetric data

    Science.gov (United States)

    The Soil and Water Assessment Tool (SWAT) model has been used to assess the impacts of alternative agricultural management practices on non-point source pollution in watersheds of various topography and scale throughout the world. Water balance is the driving force behind all processes of SWAT, as i...

  13. The Soil and Water Assessment Tool (SWAT) Ecohydrological Model Circa 2015: Global Application Trends, Insights and Issues

    Science.gov (United States)

    Gassman, P. W.; Arnold, J. G.; Srinivasan, R.

    2015-12-01

    The Soil and Water Assessment Tool (SWAT) is one of the most widely used watershed-scale water quality models in the world. Over 2,000 peer-reviewed SWAT-related journal articles have been published and hundreds of other studies have been published in conference proceedings and other formats. The use of SWAT was initially concentrated in North America and Europe but has also expanded dramatically in other countries and regions during the past decade including Brazil, China, India, Iran, South Korea, Southeast Asia and eastern Africa. The SWAT model has proven to be a very flexible tool for investigating a broad range of hydrologic and water quality problems at different watershed scales and environmental conditions, and has proven very adaptable for applications requiring improved hydrologic and other enhanced simulation needs. We investigate here the various technological, networking, and other factors that have supported the expanded use of SWAT, and also highlight current worldwide simulation trends and possible impediments to future increased usage of the model. Examples of technological advances include easy access to web-based documentation, user-support groups, and SWAT literature, a variety of Geographic Information System (GIS) interface tools, pre- and post-processing calibration software and other software, and an open source code which has served as a model development catalyst for multiple user groups. Extensive networking regarding the use of SWAT has further occurred via internet-based user support groups, model training workshops, regional working groups, regional and international conferences, and targeted development workshops. We further highlight several important model development trends that have emerged during the past decade including improved hydrologic, cropping system, best management practice (BMP) and pollutant transport simulation methods. In addition, several current SWAT weaknesses will be addressed and key development needs will be

  14. Assessment of terrain slope influence in SWAT modeling of Andean watersheds

    Science.gov (United States)

    Yacoub, C.; Pérez-Foguet, A.

    2009-04-01

    Hydrological processes in the Andean Region are difficult to model. Large range of altitudes involved (from over 4000 meters above sea level, masl, to zero) indicates the high variability of rainfall, temperature and other climate variables. Strong runoff and extreme events as landslides and floods are the consequence of high slopes of terrain, especially in the upper part of the basins. Strong seasonality of rain and complex ecosystems (vulnerable to climate changes and anthropogenic activities) helps these processes. Present study focuses in a particular watershed from Peruvian Andes, the Jequetepeque River. The distributed watershed simulation model, Soil and Water Assessment Tool (SWAT) is applied to model run-off and sediments transport through the basin with data from 1997 to 2006. Specifically, the study focuses in the assessment of the influence of considering terrain slope variation in the definition of Hydrographical Response Units within SWAT. The Jequetepeque watershed (4 372.5 km2) is located in the north part of Peru. River flows east to west, to the Pacific Ocean. Annual average precipitation ranges from 0 to 1100 mm and altitude from 0 to 4188 masl. The "Gallito Ciego" reservoir (400 masl) separates upper-middle part from lower part of the watershed. It stores water for supplying the people from the big cities on the coast and for extensive agriculture uses. Upper-middle part of the watershed covers 3564.8 km2. It ranges from 400 to 4188 masl in no more that 80 km, with slopes up to 20%. Main activities are agricultural and livestock and mining and about 80% of the population are rural. Annual mean temperature drops from 25.4 °C at the reservoir to less than 4 °C in the upper part. Also the highest rainfall variability is found in the upper-middle part of the watershed. Erosion produced by extreme events like 1997/98 "el Niño" Phenomenon is silting the reservoir faster than expected. Moreover, anthropogenic activities like agriculture and

  15. How to: understanding SWAT model uncertainty relative to measured results

    Science.gov (United States)

    Watershed models are being relied upon to contribute to most policy-making decisions of watershed management, and the demand for an accurate accounting of complete model uncertainty is rising. Generalized likelihood uncertainty estimation (GLUE) is a widely used method for quantifying uncertainty i...

  16. Value of using remotely sensed evapotranspiration for SWAT model calibration

    Science.gov (United States)

    Hydrologic models are useful management tools for assessing water resources solutions and estimating the potential impact of climate variation scenarios. A comprehensive understanding of the water budget components and especially the evapotranspiration (ET) is critical and often overlooked for adeq...

  17. The Impacts of Different Meteorology Data Sets on Nitrogen Fate and Transport in the SWAT Watershed Model

    Science.gov (United States)

    In this study, we investigated how different meteorology data sets impacts nitrogen fate and transport responses in the Soil and Water Assessment Tool (SWAT) model. We used two meteorology data sets: National Climatic Data Center (observed) and Mesoscale Model 5/Weather Research ...

  18. Remote sensing estimation of evapotranspiration for SWAT Model Calibration

    Science.gov (United States)

    Hydrological models are used to assess many water resource problems from water quantity to water quality issues. The accurate assessment of the water budget, primarily the influence of precipitation and evapotranspiration (ET), is a critical first-step evaluation, which is often overlooked in hydro...

  19. Assessment of Riparian Buffer Impacts Within the Little River Watershed in Georgia USA with the SWAT Model

    Science.gov (United States)

    Computer based hydrologic and water quality models have proven to be useful tools for examining alternative management scenarios and their impact on the environment. This examination can be an important component of watershed-scale evaluations. The Soil and Water Assessment Tool (SWAT), is a water...

  20. Modeling Fate and Transport of Fecal Coliform Bacteria Using SWAT 2005 (Case Study: Jajrood River Watershed, Iran)

    Science.gov (United States)

    Maghrebi, M.; Tajrishy, M.

    2010-12-01

    Jajrood River watershed is one of the main drinking water resources of the capital city of Tehran, Iran. In addition it has been available as many recreational usages especially in the warm months. As a result of being located near one of the crowded cities of the world, a variety of microbial pollutions is commonly perceived in the Jajrood River. Among them, there are strong concerns about fecal coliform bacteria concentration. This article aimed to model fate and transport of fecal coliform bacteria in Jajrood River watershed using Soil and Water Assessment Tool (SWAT) model version 2005. Potential pollutant sources in the study area were detected and quantified for modeling purposes. In spite of being lack of knowledge about bacteria die-off rate in small river bodies, as well as in other watershed-based forms, fecal coliform bacteria die-off rates were estimated using both laboratory and field data investigations with some simplifications. The SWAT model was calibrated over an extended time period (1997-2002) for this watershed. The river flow calibrated using SUFI-2 software and resulted in a very good outputs (R2=0.82, E=0.81). Furthermore SWAT model was validated over January 2003 to September 2005 in the study area and has resulted in good outputs (R2=0.61, E=0.57). This research illustrates SWAT 2005 capability to model fecal coliform bacteria in a populated watershed, and deals with most of watershed microbial pollution sources that are usually observed in developing countries. Fecal coliform concentration simulation results were mostly in the same order in comparison with real data. However, Differences were judged to be related to lack of input data. In this article different aspects of SWAT capabilities for modeling of fecal coliform bacteria concentration will be reviewed and it will present new insights in bacteria modeling procedures especially for mountainous, high populated and small sized watersheds.

  1. Assessment of the SWAT model to simulate a watershed with limited available data in the Pampas region, Argentina.

    Science.gov (United States)

    Romagnoli, Martín; Portapila, Margarita; Rigalli, Alfredo; Maydana, Gisela; Burgués, Martín; García, Carlos M

    2017-10-15

    Argentina has been among the world leaders in the production and export of agricultural products since the 1990s. The Carcarañá River Lower Basin (CRLB), a cropland of the Pampas region supplied by extensive rainfall, is located in an area with few streamgauging and other hydrologic/water-quality stations. Therefore, limited hydrologic data are available resulting in limited water-resources assessment. This work explores the application of Soil and Water Assessment Tool (SWAT) model to the CRLB in the Santa Fe province of the Pampas region. The analysis of field and remote-sensing data characterizing hydrology, water quality, soil types, land use/land cover, management practices, and crop yield, guarantee a comprehensive SWAT modeling approach. A combined manual and automated calibration and validation process incorporating sensitivity and uncertainty analysis is performed using information concerning interior watershed processes. Eleven N/P fertilizer rates are selected to simulate the impact of N fertilizer on crop yield, plant uptake, as well as runoff and leaching losses. Different indices (partial factor productivity, agronomic efficiency, apparent crop recovery efficiency of applied nutrient, internal utilization efficiency, and physiological efficiency) are considered to assess nitrogen-use efficiency. The overall quality of the fit is satisfactory considering the input data limitations. This work provides, for the first time in Argentina, a reliable tool to simulate yield response to soil quality and water availability capable to meet defined environmental targets to support decision making on planning public policies and private activities on the Pampas region. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Interpretation of Landscape Scale SWAT Model Outputs in the Western Lake Erie Basin: Potential Implications for Conservation Decision-Making

    Science.gov (United States)

    Johnson, M. V. V.; Behrman, K. D.; Atwood, J. D.; White, M. J.; Norfleet, M. L.

    2017-12-01

    There is substantial interest in understanding how conservation practices and agricultural management impact water quality, particularly phosphorus dynamics, in the Western Lake Erie Basin (WLEB). In 2016, the US and Canada accepted total phosphorus (TP) load targets recommended by the Great Lakes Water Quality Agreement Annex 4 Objectives and Targets Task Team; these were 6,000 MTA delivered to Lake Erie and 3,660 MTA delivered to WLEB. Outstanding challenges include development of metrics to determine achievement of these goals, establishment of sufficient monitoring capacity to assess progress, and identification of appropriate conservation practices to achieve the most cost-effective results. Process-based modeling can help inform decisions to address these challenges more quickly than can system observation. As part of the NRCS-led Conservation Effects Assessment Project (CEAP), the Soil Water Assessment Tool (SWAT) was used to predict impacts of conservation practice adoption reported by farmers on TP loss and load delivery dynamics in WLEB. SWAT results suggest that once the conservation practices in place in 2003-06 and 2012 are fully functional, TP loads delivered to WLEB will average 3,175 MTA and 3,084 MTA, respectively. In other words, SWAT predicts that currently adopted practices are sufficient to meet Annex 4 TP load targets. Yet, WLEB gauging stations show Annex 4 goals are unmet. There are several reasons the model predictions and current monitoring efforts are not in agreement: 1. SWAT assumes full functionality of simulated conservation practices; 2. SWAT does not simulate changing management over time, nor impacts of past management on legacy loads; 3. SWAT assumes WLEB hydrological system equilibrium under simulated management. The SWAT model runs used to construct the scenarios that informed the Annex 4 targets were similarly constrained by model assumptions. It takes time for a system to achieve equilibrium when management changes and it

  3. Improving SWAT for simulating water and carbon fluxes of forest ecosystems

    International Nuclear Information System (INIS)

    Yang, Qichun; Zhang, Xuesong

    2016-01-01

    As a widely used watershed model for assessing impacts of anthropogenic and natural disturbances on water quantity and quality, the Soil and Water Assessment Tool (SWAT) has not been extensively tested in simulating water and carbon fluxes of forest ecosystems. Here, we examine SWAT simulations of evapotranspiration (ET), net primary productivity (NPP), net ecosystem exchange (NEE), and plant biomass at ten AmeriFlux forest sites across the U.S. We identify unrealistic radiation use efficiency (Bio-E), large leaf to biomass fraction (Bio-LEAF), and missing phosphorus supply from parent material weathering as the primary causes for the inadequate performance of the default SWAT model in simulating forest dynamics. By further revising the relevant parameters and processes, SWAT's performance is substantially improved. Based on the comparison between the improved SWAT simulations and flux tower observations, we discuss future research directions for further enhancing model parameterization and representation of water and carbon cycling for forests. - Graphical abstract: Evaluating and improving SWAT simulations of water and carbon cycling over ten AmeriFlux sites across the United States. - Highlights: • The default forest parameterization in SWAT results in inadequate simulations of water and carbon. • Radiation use efficiency, leaf to biomass fraction, and parent material weathering processes are modified. • Revised SWAT provides improved simulations of evapotranspiration and net ecosystem exchange

  4. Improving SWAT for simulating water and carbon fluxes of forest ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qichun [Joint Global Change Research Institute, Pacific Northwest National Lab, College Park, MD 20740 (United States); Zhang, Xuesong, E-mail: xuesong.zhang@pnnl.gov [Joint Global Change Research Institute, Pacific Northwest National Lab, College Park, MD 20740 (United States); Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI 48824 (United States)

    2016-11-01

    As a widely used watershed model for assessing impacts of anthropogenic and natural disturbances on water quantity and quality, the Soil and Water Assessment Tool (SWAT) has not been extensively tested in simulating water and carbon fluxes of forest ecosystems. Here, we examine SWAT simulations of evapotranspiration (ET), net primary productivity (NPP), net ecosystem exchange (NEE), and plant biomass at ten AmeriFlux forest sites across the U.S. We identify unrealistic radiation use efficiency (Bio-E), large leaf to biomass fraction (Bio-LEAF), and missing phosphorus supply from parent material weathering as the primary causes for the inadequate performance of the default SWAT model in simulating forest dynamics. By further revising the relevant parameters and processes, SWAT's performance is substantially improved. Based on the comparison between the improved SWAT simulations and flux tower observations, we discuss future research directions for further enhancing model parameterization and representation of water and carbon cycling for forests. - Graphical abstract: Evaluating and improving SWAT simulations of water and carbon cycling over ten AmeriFlux sites across the United States. - Highlights: • The default forest parameterization in SWAT results in inadequate simulations of water and carbon. • Radiation use efficiency, leaf to biomass fraction, and parent material weathering processes are modified. • Revised SWAT provides improved simulations of evapotranspiration and net ecosystem exchange.

  5. Single-objective vs. multi-objective autocalibration in modelling total suspended solids and phosphorus in a small agricultural watershed with SWAT.

    Science.gov (United States)

    Rasolomanana, Santatriniaina Denise; Lessard, Paul; Vanrolleghem, Peter A

    2012-01-01

    To obtain greater precision in modelling small agricultural watersheds, a shorter simulation time step is beneficial. A daily time step better represents the dynamics of pollutants in the river and provides more realistic simulation results. However, with a daily evaluation performance, good fits are rarely obtained. With the Shuffled Complex Evolution (SCE) method embedded in the Soil and Water Assessment Tool (SWAT), two calibration approaches are available, single-objective or multi-objective optimization. The goal of the present study is to evaluate which approach can improve the daily performance with SWAT, in modelling flow (Q), total suspended solids (TSS) and total phosphorus (TP). The influence of weights assigned to the different variables included in the objective function has also been tested. The results showed that: (i) the model performance depends not only on the choice of calibration approach, but essentially on the influential parameters; (ii) the multi-objective calibration estimating at once all parameters related to all measured variables is the best approach to model Q, TSS and TP; (iii) changing weights does not improve model performance; and (iv) with a single-objective optimization, an excellent water quality modelling performance may hide a loss of performance of predicting flows and unbalanced internal model components.

  6. ANALISIS CURAH HUJAN DAN DEBIT MODEL SWAT DENGAN METODE MOVING AVERAGE DI DAS CILIWUNG HULU

    Directory of Open Access Journals (Sweden)

    Defri Satiya Zuma

    2017-09-01

    Full Text Available Watershed can be regarded as a hydrological system that has a function in transforming rainwater as an input into outputs such as flow and sediment. The transformation of inputs into outputs has specific forms and properties. The transformation involves many processes, including processes occurred on the surface of the land, river basins, in soil and aquifer. This study aimed to apply the SWAT model  in  Ciliwung Hulu Watershed, asses the effect of average rainfall  on 3 days, 5 days, 7 days and 10 days of the hydrological characteristics in Ciliwung Hulu Watershed. The correlation coefficient (r between rainfall and discharge was positive, it indicated that there was an unidirectional relationship between rainfall and discharge in the upstream, midstream and downstream of the watershed. The upper limit ratio of discharge had a downward trend from upstream to downstream, while the lower limit ratio of  discharge had an upward trend from upstream to downstream. It showed that the discharge peak in Ciliwung  Hulu Watershed from upstream to downstream had a downward trend while the baseflow from upstream to downstream had an upward trend. It showed that the upstream of Ciliwung Hulu Watershed had the highest ratio of discharge peak  and baseflow so it needs the soil and water conservations and technical civil measures. The discussion concluded that the SWAT model could be well applied in Ciliwung Hulu Watershed, the most affecting average rainfall on the hydrological characteristics was the average rainfall of 10 days. On average  rainfall of 10 days, all components had contributed maximally for river discharge.

  7. Scaling and design report of ECC performance test facility (SWAT) of SMART

    International Nuclear Information System (INIS)

    Cho, Seok; Ko, Yong Ju; Cho, Young Il; Kim, Jeong Tak; Choi, Nam Hyun; Shin Yong Chul; Park, Choon Kyong; Kwon, Tae Soon; Lee, Sung Jae

    2010-12-01

    SWAT (SMART ECC Water Asymmetric Two-phase choking test facility) was designed by 1/5 scaling ratio using the modified linear scaling method. The design characteristics of the SMART such that the elevation of RCP suction nozzles is the same with that of the ECC injection nozzles are maintained to reduce a distortion caused by the gravitational effect. Thermal hydraulic phenomena in a test facility designed by the modified linear scaling method can be simulated more accurately than those by the full-height and reduced area scaling method. The main part of the test section is SG-side upper down-comer. The boundary conditions are saturated steam and water flow condition and drain flow rate to control the collapsed water level in the down-comer. The test data of the SWAT can produce the well-defined boundary condition to validate the thermal hydraulic analysis code for the SMART

  8. Scaling and design report of ECC performance test facility (SWAT) of SMART

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Seok; Ko, Yong Ju; Cho, Young Il; Kim, Jeong Tak; Choi, Nam Hyun; Shin Yong Chul; Park, Choon Kyong; Kwon, Tae Soon; Lee, Sung Jae [KAERI, Daejeon (Korea, Republic of)

    2010-12-15

    SWAT (SMART ECC Water Asymmetric Two-phase choking test facility) was designed by 1/5 scaling ratio using the modified linear scaling method. The design characteristics of the SMART such that the elevation of RCP suction nozzles is the same with that of the ECC injection nozzles are maintained to reduce a distortion caused by the gravitational effect. Thermal hydraulic phenomena in a test facility designed by the modified linear scaling method can be simulated more accurately than those by the full-height and reduced area scaling method. The main part of the test section is SG-side upper down-comer. The boundary conditions are saturated steam and water flow condition and drain flow rate to control the collapsed water level in the down-comer. The test data of the SWAT can produce the well-defined boundary condition to validate the thermal hydraulic analysis code for the SMART

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

    Science.gov (United States)

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

    2013-12-01

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

  10. Watershed Modeling with ArcSWAT and SUFI2 In Cisadane Catchment Area: Calibration and Validation of River Flow Prediction

    Directory of Open Access Journals (Sweden)

    Iwan Ridwansyah

    2014-04-01

    Full Text Available Increasing of natural resources utilization as a result of population growth and economic development has caused severe damage on the watershed. The impacts of natural disasters such as floods, landslides and droughts become more frequent. Cisadane Catchment Area is one of 108 priority watershed in Indonesia. SWAT is currently applied world wide and considered as a versatile model that can be used to integrate multiple environmental processes, which support more effective watershed management and the development of better informed policy decision. The objective of this study is to examine the applicability of SWAT model for modeling mountainous catchments, focusing on Cisadane catchment Area in west Java Province, Indonesia. The SWAT model simulation was done for the periods of 2005 – 2010 while it used landuse information in 2009. Methods of Sequential Uncertainty Fitting ver. 2 (SUFI2 and combine with manual calibration were used in this study to calibrate a rainfall-runoff. The Calibration is done on 2007 and the validation on 2009, the R2 and Nash Sutchliffe Efficiency (NSE of the calibration were 0.71 and 0.72 respectively and the validation are 0.708 and 0.7 respectively. The monthly average of surface runoff and total water yield from the simulation were 27.7 mm and 2718.4 mm respectively. This study showed SWAT model can be a potential monitoring tool especially for watersheds in Cisadane Catchment Area or in the tropical regions. The model can be used for another purpose, especially in watershed management.

  11. Stream Flow Simulation of a Snow-Fed Mountainous Basin Using the SWAT Model

    Science.gov (United States)

    Shukla, S.; Kansal, M. L.; Jain, S. K.

    2017-12-01

    Hydrological budget of the Satluj River (a major tributary of Indus river system) in Western Himalaya, is dominated by monsoonal rainfall and snowmelt during the non-monsoon months. The river watershed experiences extensive snowfall in the winters and snowmelt runoff substantially contributes to the streamflow of the river in the spring and summer months. In order to understand the hydrologic response of Satluj basin, hydrological modeling study is carried out using a semi distributed hydrological model Soil and Water Assessment Tool (SWAT), for the period of thirty years (1985-2014). The basic intent of this study is to derive the parameters required for runoff modeling using the geospatial database. The Sequential Uncertainty Fitting (SUFI-2) algorithm is used to calibrate and validate the model and incorporate uncertainties in the analysis. The results are validated with the observed daily streamflow data at Rampur, in terms of Nash-Sutcliffe Coefficient (NSC), R2 and Root Mean Square Error (RMSE). Further, the snowmelt-runoff mechanism is modelled by relating the temperature changes to the elevation band in the basin. The northern part of the basin and the south part of the basin on the high elevation zones have the coldest maximum temperatures that is about 7°C. It is found that the average contribution of snow and glacier runoff in the annual flow of the Satluj River at Rampur is about 66% and remaining 34% is from rainfall.

  12. Assessment of the Environmental Fate of the Herbicides Flufenacet and Metazachlor with the SWAT Model.

    Science.gov (United States)

    Fohrer, Nicola; Dietrich, Antje; Kolychalow, Olga; Ulrich, Uta

    2014-01-01

    This study aims to assess the environmental fate of the commonly used herbicides flufenacet and metazachlor in the Northern German Lowlands with the ecohydrological Soil and Water Assessment Tool (SWAT model) and to test the sensitivity of pesticide-related input parameters on the modeled transport dynamics. The river discharge of the Kielstau watershed was calibrated (Nash-Sutcliffe efficiency [NSE], 0.83; = 0.84) and validated (NSE, 0.76; = 0.77) for a daily time step. The environmental fate of metazachlor (NSE, 0.68; = 0.62) and flufenacet (NSE, 0.13; = 0.51) was simulated adequately. In comparison to metazachlor, the simulated flufenacet concentration and loads show a lower model efficiency due to the weaker simulation of the stream flow. The in-stream herbicide loads were less than 0.01% of the applied amount in the observed time period and thus not in conflict with European Environmental Legislation. The sensitivity analysis showed that, besides the accurate simulation of stream flow, the parameterization of the temporal and spatial distribution of the herbicide application throughout the watershed is the key factor for appropriate modeling results, whereas the physicochemical properties of the pesticides play a minor role in the modeling process. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  13. Modeling Miscanthus in the soil and water assessment tool (SWAT) to simulate its water quality effects as a bioenergy crop.

    Science.gov (United States)

    Ng, Tze Ling; Eheart, J Wayland; Cai, Ximing; Miguez, Fernando

    2010-09-15

    There is increasing interest in perennial grasses as a renewable source of bioenergy and feedstock for second-generation cellulosic biofuels. The primary objective of this study is to estimate the potential effects on riverine nitrate load of cultivating Miscanthus x giganteus in place of conventional crops. In this study, the Soil and Water Assessment Tool (SWAT) is used to model miscanthus growth and streamwater quality in the Salt Creek watershed in Illinois. SWAT has a built-in crop growth component, but, as miscanthus is relatively new as a potentially commercial crop, data on the SWAT crop growth parameters for the crop are lacking. This leads to the second objective of this study, which is to estimate those parameters to facilitate the modeling of miscanthus in SWAT. Results show a decrease in nitrate load that depends on the percent land use change to miscanthus and the amount of nitrogen fertilizer applied to the miscanthus. Specifically, assuming a nitrogen fertilization rate for miscanthus of 90 kg-N/ha, a 10%, 25%, and 50% land use change to miscanthus will lead to decreases in nitrate load of about 6.4%, 16.5%, and 29.6% at the watershed outlet, respectively. Likewise, nitrate load may be reduced by lowering the fertilizer application rate, but not proportionately. When fertilization drops from 90 to 30 kg-N/ha the difference in nitrate load decrease is less than 1% when 10% of the watershed is miscanthus and less than 6% when 50% of the watershed is miscanthus. It is also found that the nitrate load decrease from converting less than half the watershed to miscanthus from corn and soybean in 1:1 rotation surpasses that from converting the whole watershed to just soybean.

  14. Land use change impacts on discharge analysis using SWAT model at Ciherang Pondok DAM catchment area

    Science.gov (United States)

    Utamahadi, M. A.; Pandjaitan, N. H.; Rau, M. I.

    2018-05-01

    The prompt increase of population influenced the requirement for new regions to fulfill people’s primary needs. Its increased land use change and caused many impacts on the environment, including watersheds as well. Ciherang Pondok DAM catchment area is part of Cisadane watershed and was selected as the research area. This research aimed to analyse the water supply and water discharge change caused by the Urban Planning (RTRW) in 2020. The analysis was conducted using soil and water assessment tools (SWAT) model. Stages of this research were catchment area delineation, HRU identification, calibration and validation of models, and prediction of discharge and water demand. The result showed that RTRW of 2020 increased the maximum discharge of 1.6 m3/s and decreased the minimum discharge of 0.01 m3/s, hence the maximum and minimum discharge ratio increased 0.26% from 2016. Output discharge in 2020 at Ciherang Pondok Dam Catchment Area was classified as well, with discharge of 6.72 – 126.2 m3/s, and could fulfil water demand. For the best result, it is better to use climate data from weather stations inside the study area and it is required an improvement in data archiving system.

  15. Evaluation of nutrient retention in vegetated filter strips using the SWAT model.

    Science.gov (United States)

    Elçi, Alper

    2017-11-01

    Nutrient fluxes in stream basins need to be controlled to achieve good water quality status. In stream basins with intensive agricultural activities, nutrients predominantly come from diffuse sources. Therefore, best management practices (BMPs) are increasingly implemented to reduce nutrient input to streams. The objective of this study is to evaluate the impact of vegetated filter strip (VFS) application as an agricultural BMP. For this purpose, SWAT is chosen, a semi-distributed water quality assessment model that works at the watershed scale, and applied on the Nif stream basin, a small-sized basin in Western Turkey. The model is calibrated with an automated procedure against measured monthly discharge data. Nutrient loads for each sub-basin are estimated considering basin-wide data on chemical fertilizer and manure usage, population data for septic tank effluents and information about the land cover. Nutrient loads for 19 sub-basins are predicted on an annual basis. Average total nitrogen and total phosphorus loads are estimated as 47.85 t/yr and 13.36 t/yr for the entire basin. Results show that VFS application in one sub-basin offers limited retention of nutrients and that a selection of 20-m filter width is most effective from a cost-benefit perspective.

  16. Modeling pesticide diuron loading from the San Joaquin watershed into the Sacramento-San Joaquin Delta using SWAT.

    Science.gov (United States)

    Chen, Huajin; Luo, Yuzhou; Potter, Christopher; Moran, Patrick J; Grieneisen, Michael L; Zhang, Minghua

    2017-09-15

    Quantifying pesticide loading into the Sacramento-San Joaquin Delta of northern California is critical for water quality management in the region, and potentially useful for biological weed control planning. In this study, the Soil and Water Assessment Tool (SWAT) was applied to model streamflow, sediment, and pesticide diuron loading in the San Joaquin watershed, a major contributing area to the elevated pesticide levels in the downstream Delta. The Sequential Uncertainty Fitting version 2 (SUFI-2) algorithm was employed to perform calibration and uncertainty analysis. A combination of performance measures (PMs) and standardized performance evaluation criteria (PEC) was applied to evaluate model performance, while prediction uncertainty was quantified by 95% prediction uncertainty band (95PPU). Results showed that streamflow simulation was at least "satisfactory" at most stations, with more than 50% of the observed data bracketed by the 95PPU. Sediment simulation was rated as at least "satisfactory" based on two PMs, and diuron simulation was judged as "good" by all PMs. The 95PPU of sediment and diuron bracketed about 40% and 30% of the observed data, respectively. Significant correlations were observed between the diuron loads, and precipitation, streamflow, and the current and antecedent pesticide use. Results also showed that the majority (>70%) of agricultural diuron was transported during winter months, when direct exposure of biocontrol agents to diuron runoff is limited. However, exposure in the dry season could be a concern because diuron is relatively persistent in aquatic system. This study not only provides valuable information for the development of biological weed control plan in the Delta, but also serves as a foundation for the continued research on calibration, evaluation, and uncertainty analysis of spatially distributed, physically based hydrologic models. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Improving SWAT for simulating water and carbon fluxes of forest ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qichun; Zhang, Xuesong

    2016-11-01

    As a widely used watershed model for assessing impacts of anthropogenic and natural disturbances on water quantity and quality, the Soil and Water Assessment Tool (SWAT) has not been extensively tested in simulating water and carbon fluxes of forest ecosystems. Here, we examine SWAT simulations of evapotranspiration (ET), net primary productivity (NPP), net ecosystem exchange (NEE), and plant biomass at ten AmeriFlux forest sites across the U.S. We identify unrealistic radiation use efficiency (Bio_E), large leaf to biomass fraction (Bio_LEAF), and missing phosphorus supply from parent material weathering as the primary causes for the inadequate performance of the default SWAT model in simulating forest dynamics. By further revising the relevant parameters and processes, SWAT’s performance is substantially improved. Based on the comparison between the improved SWAT simulations and flux tower observations, we discuss future research directions for further enhancing model parameterization and representation of water and carbon cycling for forests.

  18. Baseflow simulation using SWAT model in an inland river basin in Tianshan Mountains, Northwest China

    Directory of Open Access Journals (Sweden)

    Y. Luo

    2012-04-01

    Full Text Available Baseflow is an important component in hydrological modeling. The complex streamflow recession process complicates the baseflow simulation. In order to simulate the snow and/or glacier melt dominated streamflow receding quickly during the high-flow period but very slowly during the low-flow period in rivers in arid and cold northwest China, the current one-reservoir baseflow approach in SWAT (Soil Water Assessment Tool model was extended by adding a slow- reacting reservoir and applying it to the Manas River basin in the Tianshan Mountains. Meanwhile, a digital filter program was employed to separate baseflow from streamflow records for comparisons. Results indicated that the two-reservoir method yielded much better results than the one-reservoir one in reproducing streamflow processes, and the low-flow estimation was improved markedly. Nash-Sutcliff efficiency values at the calibration and validation stages are 0.68 and 0.62 for the one-reservoir case, and 0.76 and 0.69 for the two-reservoir case. The filter-based method estimated the baseflow index as 0.60, while the model-based as 0.45. The filter-based baseflow responded almost immediately to surface runoff occurrence at onset of rising limb, while the model-based responded with a delay. In consideration of watershed surface storage retention and soil freezing/thawing effects on infiltration and recharge during initial snowmelt season, a delay response is considered to be more reasonable. However, a more detailed description of freezing/thawing processes should be included in soil modules so as to determine recharge to aquifer during these processes, and thus an accurate onset point of rising limb of the simulated baseflow.

  19. Modeling pesticide loadings from the San Joaquin watershed into the Sacramento-San Joaquin Delta using SWAT

    Science.gov (United States)

    Chen, H.; Zhang, M.

    2016-12-01

    The Sacramento-San Joaquin Delta is an ecologically rich, hydrologically complex area that serves as the hub of California's water supply. However, pesticides have been routinely detected in the Delta waterways, with concentrations exceeding the benchmark for the protection of aquatic life. Pesticide loadings into the Delta are partially attributed to the San Joaquin watershed, a highly productive agricultural watershed located upstream. Therefore, this study aims to simulate pesticide loadings to the Delta by applying the Soil and Water Assessment Tool (SWAT) model to the San Joaquin watershed, under the support of the USDA-ARS Delta Area-Wide Pest Management Program. Pesticide use patterns in the San Joaquin watershed were characterized by combining the California Pesticide Use Reporting (PUR) database and GIS analysis. Sensitivity/uncertainty analyses and multi-site calibration were performed in the simulation of stream flow, sediment, and pesticide loads along the San Joaquin River. Model performance was evaluated using a combination of graphic and quantitative measures. Preliminary results indicated that stream flow was satisfactorily simulated along the San Joaquin River and the major eastern tributaries, whereas stream flow was less accurately simulated in the western tributaries, which are ephemeral small streams that peak during winter storm events and are mainly fed by irrigation return flow during the growing season. The most sensitive parameters to stream flow were CN2, SOL_AWC, HRU_SLP, SLSUBBSN, SLSOIL, GWQMN and GW_REVAP. Regionalization of parameters is important as the sensitivity of parameters vary significantly spatially. In terms of evaluation metric, NSE tended to overrate model performance when compared to PBIAS. Anticipated results will include (1) pesticide use pattern analysis, (2) calibration and validation of stream flow, sediment, and pesticide loads, and (3) characterization of spatial patterns and temporal trends of pesticide yield.

  20. Uncertainty of SWAT model at different DEM resolutions in a large mountainous watershed.

    Science.gov (United States)

    Zhang, Peipei; Liu, Ruimin; Bao, Yimeng; Wang, Jiawei; Yu, Wenwen; Shen, Zhenyao

    2014-04-15

    The objective of this study was to enhance understanding of the sensitivity of the SWAT model to the resolutions of Digital Elevation Models (DEMs) based on the analysis of multiple evaluation indicators. The Xiangxi River, a large tributary of Three Gorges Reservoir in China, was selected as the study area. A range of 17 DEM spatial resolutions, from 30 to 1000 m, was examined, and the annual and monthly model outputs based on each resolution were compared. The following results were obtained: (i) sediment yield was greatly affected by DEM resolution; (ii) the prediction of dissolved oxygen load was significantly affected by DEM resolutions coarser than 500 m; (iii) Total Nitrogen (TN) load was not greatly affected by the DEM resolution; (iv) Nitrate Nitrogen (NO₃-N) and Total Phosphorus (TP) loads were slightly affected by the DEM resolution; and (v) flow and Ammonia Nitrogen (NH₄-N) load were essentially unaffected by the DEM resolution. The flow and dissolved oxygen load decreased more significantly in the dry season than in the wet and normal seasons. Excluding flow and dissolved oxygen, the uncertainties of the other Hydrology/Non-point Source (H/NPS) pollution indicators were greater in the wet season than in the dry and normal seasons. Considering the temporal distribution uncertainties, the optimal DEM resolutions for flow was 30-200 m, for sediment and TP was 30-100 m, for dissolved oxygen and NO₃-N was 30-300 m, for NH₄-N was 30 to 70 m and for TN was 30-150 m. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Modelling land use change across elevation gradients in district Swat, Pakistan

    NARCIS (Netherlands)

    Qasim, M.; Termansen, M.; Hubacek, K.; Fleskens, L.

    2013-01-01

    District Swat is part of the high mountain Hindu-Kush Himalayan region of Pakistan. Documentation and analysis of land use change in this region is challenging due to very disparate accounts of the state of forest resources and limited accessible data. Such analysis is, however, important due to

  2. The modified SWAT model for predicting fecal coliform in the Wachusett Reservoir Watershed, USA

    Science.gov (United States)

    Fecal contamination has been an issue for water quality because fecal coliform bacteria are used as an indicator organism to detect pathogens in water. In order to assess fecal contamination in the Wachusett Reservoir Watershed in Massachusetts, USA, the Soil and Water Assessment Tool (SWAT), a comm...

  3. Application of SELECT and SWAT models to simulate source load, fate, and transport of fecal bacteria in watersheds.

    Science.gov (United States)

    Ranatunga, T.

    2017-12-01

    Modeling of fate and transport of fecal bacteria in a watershed is a processed based approach that considers releases from manure, point sources, and septic systems. Overland transport with water and sediments, infiltration into soils, transport in the vadose zone and groundwater, die-off and growth processes, and in-stream transport are considered as the other major processes in bacteria simulation. This presentation will discuss a simulation of fecal indicator bacteria source loading and in-stream conditions of a non-tidal watershed (Cedar Bayou Watershed) in South Central Texas using two models; Spatially Explicit Load Enrichment Calculation Tool (SELECT) and Soil and Water Assessment Tool (SWAT). Furthermore, it will discuss a probable approach of bacteria source load reduction in order to meet the water quality standards in the streams. The selected watershed is listed as having levels of fecal indicator bacteria that posed a risk for contact recreation and wading by the Texas Commission of Environmental Quality (TCEQ). The SELECT modeling approach was used in estimating the bacteria source loading from land categories. Major bacteria sources considered were, failing septic systems, discharges from wastewater treatment facilities, excreta from livestock (Cattle, Horses, Sheep and Goat), excreta from Wildlife (Feral Hogs, and Deer), Pet waste (mainly from Dogs), and runoff from urban surfaces. The estimated source loads from SELECT model were input to the SWAT model, and simulate the bacteria transport through the land and in-stream. The calibrated SWAT model was then used to estimate the indicator bacteria in-stream concentrations for future years based on regional land use, population and household forecast (up to 2040). Based on the reductions required to meet the water quality standards in-stream, the corresponding required source load reductions were estimated.

  4. Improvement of the R-SWAT-FME framework to support multiple variables and multi-objective functions

    Science.gov (United States)

    Wu, Yiping; Liu, Shu-Guang

    2014-01-01

    Application of numerical models is a common practice in the environmental field for investigation and prediction of natural and anthropogenic processes. However, process knowledge, parameter identifiability, sensitivity, and uncertainty analyses are still a challenge for large and complex mathematical models such as the hydrological/water quality model, Soil and Water Assessment Tool (SWAT). In this study, the previously developed R program language-SWAT-Flexible Modeling Environment (R-SWAT-FME) was improved to support multiple model variables and objectives at multiple time steps (i.e., daily, monthly, and annually). This expansion is significant because there is usually more than one variable (e.g., water, nutrients, and pesticides) of interest for environmental models like SWAT. To further facilitate its easy use, we also simplified its application requirements without compromising its merits, such as the user-friendly interface. To evaluate the performance of the improved framework, we used a case study focusing on both streamflow and nitrate nitrogen in the Upper Iowa River Basin (above Marengo) in the United States. Results indicated that the R-SWAT-FME performs well and is comparable to the built-in auto-calibration tool in multi-objective model calibration. Overall, the enhanced R-SWAT-FME can be useful for the SWAT community, and the methods we used can also be valuable for wrapping potential R packages with other environmental models.

  5. A comparison of SWAT, HSPF and SHETRAN/GOPC for modelling phosphorus export from three catchments in Ireland.

    Science.gov (United States)

    Nasr, Ahmed; Bruen, Michael; Jordan, Philip; Moles, Richard; Kiely, Gerard; Byrne, Paul

    2007-03-01

    Recent extensive water quality surveys in Ireland revealed that diffuse phosphorus (P) pollution originating from agricultural land and transported by runoff and subsurface flows is the primary cause of the deterioration of surface water quality. P transport from land to water can be described by mathematical models that vary in modelling approach, complexity and scale (plot, field and catchment). Here, three mathematical models (soil water and analysis tools (SWAT), hydrological simulation program-FORTRAN (HSPF) and système hydrologique Européen TRANsport (SHETRAN)/grid oriented phosphorus component (GOPC)) of diffuse P pollution have been tested in three Irish catchments to explore their suitability in Irish conditions for future use in implementing the European Water Framework Directive. After calibrating the models, their daily flows and total phosphorus (TP) exports are compared and assessed. The HSPF model was the best at simulating the mean daily discharge while SWAT gave the best calibration results for daily TP loads. Annual TP exports for the three models and for two empirical models were compared with measured data. No single model is consistently better in estimating the annual TP export for all three catchments.

  6. Spatial multiobjective optimization of agricultural conservation practices using a SWAT model and an evolutionary algorithm.

    Science.gov (United States)

    Rabotyagov, Sergey; Campbell, Todd; Valcu, Adriana; Gassman, Philip; Jha, Manoj; Schilling, Keith; Wolter, Calvin; Kling, Catherine

    2012-12-09

    Finding the cost-efficient (i.e., lowest-cost) ways of targeting conservation practice investments for the achievement of specific water quality goals across the landscape is of primary importance in watershed management. Traditional economics methods of finding the lowest-cost solution in the watershed context (e.g.,(5,12,20)) assume that off-site impacts can be accurately described as a proportion of on-site pollution generated. Such approaches are unlikely to be representative of the actual pollution process in a watershed, where the impacts of polluting sources are often determined by complex biophysical processes. The use of modern physically-based, spatially distributed hydrologic simulation models allows for a greater degree of realism in terms of process representation but requires a development of a simulation-optimization framework where the model becomes an integral part of optimization. Evolutionary algorithms appear to be a particularly useful optimization tool, able to deal with the combinatorial nature of a watershed simulation-optimization problem and allowing the use of the full water quality model. Evolutionary algorithms treat a particular spatial allocation of conservation practices in a watershed as a candidate solution and utilize sets (populations) of candidate solutions iteratively applying stochastic operators of selection, recombination, and mutation to find improvements with respect to the optimization objectives. The optimization objectives in this case are to minimize nonpoint-source pollution in the watershed, simultaneously minimizing the cost of conservation practices. A recent and expanding set of research is attempting to use similar methods and integrates water quality models with broadly defined evolutionary optimization methods(3,4,9,10,13-15,17-19,22,23,25). In this application, we demonstrate a program which follows Rabotyagov et al.'s approach and integrates a modern and commonly used SWAT water quality model(7) with a

  7. A multi basin SWAT model analysis of runoff and sedimentation in the Blue Nile, Ethiopia

    Directory of Open Access Journals (Sweden)

    Z. M. Easton

    2010-10-01

    Full Text Available A multi basin analysis of runoff and erosion in the Blue Nile Basin, Ethiopia was conducted to elucidate sources of runoff and sediment. Erosion is arguably the most critical problem in the Blue Nile Basin, as it limits agricultural productivity in Ethiopia, degrades benthos in the Nile, and results in sedimentation of dams in downstream countries. A modified version of the Soil and Water Assessment Tool (SWAT model was developed to predict runoff and sediment losses from the Ethiopian Blue Nile Basin. The model simulates saturation excess runoff from the landscape using a simple daily water balance coupled to a topographic wetness index in ways that are consistent with observed runoff processes in the basin. The spatial distribution of landscape erosion is thus simulated more correctly. The model was parameterized in a nested design for flow at eight and sediment at three locations in the basin. Subbasins ranged in size from 1.3 to 174 000 km2, and interestingly, the partitioning of runoff and infiltrating flow could be predicted by topographic information. Model predictions showed reasonable accuracy (Nash Sutcliffe Efficiencies ranged from 0.53–0.92 with measured data across all sites except Kessie, where the water budget could not be closed; however, the timing of flow was well captured. Runoff losses increased with rainfall during the monsoonal season and were greatest from areas with shallow soils and large contributing areas. Analysis of model results indicate that upland landscape erosion dominated sediment delivery to the main stem of the Blue Nile in the early part of the growing season when tillage occurs and before the soil was wetted up and plant cover was established. Once plant cover was established in mid August landscape erosion was negligible and sediment export was dominated by channel processes and re-suspension of landscape sediment deposited early in the growing season. These results imply that targeting small

  8. Pesticide transport to tile-drained fields in SWAT model – macropore flow and sediment

    DEFF Research Database (Denmark)

    Lu, Shenglan; Trolle, Dennis; Blicher-Mathiesen, Gitte

    2015-01-01

    Tool (SWAT) to simulate transport of both mobile (e.g. Bentazon) and strongly sorbed (e.g. Diuron) pesticides in tile drains. Macropore flow is initiated when soil water content exceeds a threshold and rainfall intensity exceeds infiltration capacity. The amount of macropore flow is calculated...... to macropore sediment transport. Simulated tile drain discharge, sediment and pesticide loads are calibrated against data from intensively monitored tile-drained fields and streams in Denmark....

  9. Pesticide transport simulation in a tropical catchment by SWAT

    International Nuclear Information System (INIS)

    Bannwarth, M.A.; Sangchan, W.; Hugenschmidt, C.; Lamers, M.; Ingwersen, J.; Ziegler, A.D.; Streck, T.

    2014-01-01

    The application of agrochemicals in Southeast Asia is increasing in rate, variety and toxicity with alarming speed. Understanding the behavior of these different contaminants within the environment require comprehensive monitoring programs as well as accurate simulations with hydrological models. We used the SWAT hydrological model to simulate the fate of three different pesticides, one of each usage type (herbicide, fungicide and insecticide) in a mountainous catchment in Northern Thailand. Three key parameters were identified: the sorption coefficient, the decay coefficient and the coefficient controlling pesticide percolation. We yielded satisfactory results simulating pesticide load dynamics during the calibration period (NSE: 0.92–0.67); the results during the validation period were also acceptable (NSE: 0.61–0.28). The results of this study are an important step in understanding the modeling behavior of these pesticides in SWAT and will help to identify thresholds of worst-case scenarios in order to assess the risk for the environment. - Highlights: • We performed a global LH-sensitivity analysis of all pesticide related parameters. • Key physical parameters are associated to percolation, degradation and sorption. • We simulated the measured loads of three different pesticides. • We performed an uncertainty analysis of all pesticide simulations. • All Pesticides differed considerably in their sensitivity and simulation behavior. - Pesticide load simulations of three pesticides were modeled by SWAT, providing clues on how to handle pesticides in future SWAT studies

  10. Comment on “Modeling Miscanthus in the Soil and Water Assessment Tool (SWAT) to Simulate Its Water Quality Effects As a Bioenergy Crop”

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xuesong; Izaurralde, Roberto C.; Arnold, J. G.; Sammons, N. B.; Manowitz, David H.; Thomson, Allison M.; Williams, J.R.

    2011-07-01

    In this paper, the authors comment on several mistakes made in a journal paper "Modeling Miscanthus in the Soil and Water Assessment Tool (SWAT) to Simulate Its Water Quality Effects As a Bioenergy Crop" published on Environmental Scienece & Technology, based on field measurements from Great Lakes Bioenergy Research Center, Carbon Sequestration in Terrestrial Ecosystems, and published literature. Our comment has led to the development of another version of SWAT to include better process based description of radiation use efficiency and root-shoot growth.

  11. Streamflow in the upper Mississippi river basin as simulated by SWAT driven by 20{sup th} century contemporary results of global climate models and NARCCAP regional climate models

    Energy Technology Data Exchange (ETDEWEB)

    Takle, Eugene S.; Jha, Manoj; Lu, Er; Arritt, Raymond W.; Gutowski, William J. [Iowa State Univ. Ames, IA (United States)

    2010-06-15

    We use Soil and Water Assessment Tool (SWAT) when driven by observations and results of climate models to evaluate hydrological quantities, including streamflow, in the Upper Mississippi River Basin (UMRB) for 1981-2003 in comparison to observed streamflow. Daily meteorological conditions used as input to SWAT are taken from (1) observations at weather stations in the basin, (2) daily meteorological conditions simulated by a collection of regional climate models (RCMs) driven by reanalysis boundary conditions, and (3) daily meteorological conditions simulated by a collection of global climate models (GCMs). Regional models used are those whose data are archived by the North American Regional Climate Change Assessment Program (NARCCAP). Results show that regional models correctly simulate the seasonal cycle of precipitation, temperature, and streamflow within the basin. Regional models also capture interannual extremes represented by the flood of 1993 and the dry conditions of 2000. The ensemble means of both the GCM-driven and RCM-driven simulations by SWAT capture both the timing and amplitude of the seasonal cycle of streamflow with neither demonstrating significant superiority at the basin level. (orig.)

  12. SWAT Model Application to Assess the Impact of Intensive Corn‐farming on Runoff, Sediments and Phosphorous loss from an Agricultural Watershed in Wisconsin

    Science.gov (United States)

    The potential future increase in corn-based biofuel may be expected to have a negative impact on water quality in streams and lakes of the Midwestern US due to increased agricultural chemicals usage. This study used the SWAT model to assess the impact of continuous-corn farming o...

  13. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

    Science.gov (United States)

    Liu, Xin; Wang, Sufen; Xue, Han; Singh, Vijay P

    2015-01-01

    Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

  14. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

    Directory of Open Access Journals (Sweden)

    Xin Liu

    Full Text Available Modelling crop evapotranspiration (ET response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1 and summer maize (scenario 2 by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

  15. Modeling the Impacts of Spatial Heterogeneity in the Castor Watershed on Runoff, Sediment, and Phosphorus Loss Using SWAT: I. Impacts of Spatial Variability of Soil Properties.

    Science.gov (United States)

    Boluwade, Alaba; Madramootoo, Chandra

    2013-01-01

    Spatial accuracy of hydrologic modeling inputs influences the output from hydrologic models. A pertinent question is to know the optimal level of soil sampling or how many soil samples are needed for model input, in order to improve model predictions. In this study, measured soil properties were clustered into five different configurations as inputs to the Soil and Water Assessment Tool (SWAT) simulation of the Castor River watershed (11-km 2 area) in southern Quebec, Canada. SWAT is a process-based model that predicts the impacts of climate and land use management on water yield, sediment, and nutrient fluxes. SWAT requires geographical information system inputs such as the digital elevation model as well as soil and land use maps. Mean values of soil properties are used in soil polygons (soil series); thus, the spatial variability of these properties is neglected. The primary objective of this study was to quantify the impacts of spatial variability of soil properties on the prediction of runoff, sediment, and total phosphorus using SWAT. The spatial clustering of the measured soil properties was undertaken using the regionalized with dynamically constrained agglomerative clustering and partitioning method. Measured soil data were clustered into 5, 10, 15, 20, and 24 heterogeneous regions. Soil data from the Castor watershed which have been used in previous studies was also set up and termed "Reference". Overall, there was no significant difference in runoff simulation across the five configurations including the reference. This may be attributable to SWAT's use of the soil conservation service curve number method in flow simulation. Therefore having high spatial resolution inputs for soil data may not necessarily improve predictions when they are used in hydrologic modeling.

  16. Avaliação da carga mental de trabalho e do desempenho de medidas de mensuração: NASA TLX e SWAT Evaluation of mental workload and performance measurement: NASA TLX and SWAT

    Directory of Open Access Journals (Sweden)

    Mariane de Souza Cardoso

    2012-12-01

    workload used in studies of ergonomics show workers' skills and limitations, characteristics of work organization, and facilitate the presentation of quantitative and qualitative results. The comparison of the performance of these two mental workload assessment methods proved a relevant investigation to the field of ergonomics since there are few comparative studies on the performance of these methods. With regard to the overall comparison of the performance of these methods, NASA TLX allows the evaluation of mental workload by analyzing several dimensions of the work situation and presents advantages when compared to SWAT because it can be easily implemented and showed greater acceptance by those who evaluated it

  17. [Impact of changes in land use and climate on the runoff in Liuxihe Watershed based on SWAT model].

    Science.gov (United States)

    Yuan, Yu-zhi; Zhang, Zheng-dong; Meng, Jin-hua

    2015-04-01

    SWAT model, an extensively used distributed hydrological model, was used to quantitatively analyze the influences of changes in land use and climate on the runoff at watershed scale. Liuxihe Watershed' s SWAT model was established and three scenarios were set. The calibration and validation at three hydrological stations of Wenquan, Taipingchang and Nangang showed that the three factors of Wenquan station just only reached the standard in validated period, and the other two stations had relative error (RE) 0.8 and Nash-Sutcliffe efficiency valve (Ens) > 0.75, suggesting that SWAT model was appropriate for simulating runoff response to land use change and climate variability in Liuxihe watershed. According to the integrated scenario simulation, the annual runoff increased by 11.23 m3 x s(-1) from 2001 to 2010 compared with the baseline period from 1991 to 2000, among which, the land use change caused an annual runoff reduction of 0.62 m3 x s(-1), whereas climate variability caused an annual runoff increase of 11.85 m3 x s(-1). Apparently, the impact of climate variability was stronger than that of land use change. On the other hand, the scenario simulation of extreme land use showed that compared with the land use in 2000, the annual runoff of the farmland scenario and the grassland scenario increased by 2.7% and 0.5% respectively, while that of the forest land scenario were reduced by 0.7%, which suggested that forest land had an ability of diversion closure. Furthermore, the scenario simulation of climatic variability indicated that the change of river runoff correlated positively with precipitation change (increase of 11.6% in annual runoff with increase of 10% in annual precipitation) , but negatively with air temperature change (reduction of 0.8% in annual runoff with increase of 1 degrees C in annual mean air temperature), which showed that the impact of precipitation variability was stronger than that of air temperature change. Therefore, in face of climate

  18. SWAT (Student Weekend Arborist Team): A Model for Land Grant Institutions and Cooperative Extension Systems to Conduct Street Tree Inventories

    Science.gov (United States)

    Cowett, F.D.; Bassuk, N.L.

    2012-01-01

    SWAT (Student Weekend Arborist Team) is a program affiliated with Cornell University and Extension founded to conduct street tree inventories in New York State communities with 10,000 residents or fewer, a group of communities underserved in community forestry planning. Between 2002 and 2010, SWAT conducted 40 inventories, and data from these…

  19. Runoff Simulation in the Upper Reaches of Heihe River Basin Based on the RIEMS–SWAT Model

    Directory of Open Access Journals (Sweden)

    Songbing Zou

    2016-10-01

    Full Text Available In the distributed hydrological simulations for complex mountain areas, large amounts of meteorological input parameters with high spatial and temporal resolutions are necessary. However, the extreme scarcity and uneven distribution of the traditional meteorological observation stations in cold and arid regions of Northwest China makes it very difficult in meeting the requirements of hydrological simulations. Alternatively, regional climate models (RCMs, which can provide a variety of distributed meteorological data with high temporal and spatial resolution, have become an effective solution to improve hydrological simulation accuracy and to further study water resource responses to human activities and global climate change. In this study, abundant and evenly distributed virtual weather stations in the upper reaches of the Heihe River Basin (HRB of Northwest China were built for the optimization of the input data, and thus a regional integrated environmental model system (RIEMS based on RCM and a distributed hydrological model of soil and water assessment tool (SWAT were integrated as a coupled climate–hydrological RIEMS-SWAT model, which was applied to simulate monthly runoff from 1995 to 2010 in the region. Results show that the simulated and observed values are close; Nash–Sutcliffe efficiency is higher than 0.65; determination coefficient (R2 values are higher than 0.70; percent bias is controlled within ±20%; and root-mean-square-error-observation standard deviation ratio is less than 0.65. These results indicate that the coupled model can present basin hydrological processes properly, and provide scientific support for prediction and management of basin water resources.

  20. Evaluating Uncertainty of Runoff Simulation using SWAT model of the Feilaixia Watershed in China Based on the GLUE Method

    Science.gov (United States)

    Chen, X.; Huang, G.

    2017-12-01

    In recent years, distributed hydrological models have been widely used in storm water management, water resources protection and so on. Therefore, how to evaluate the uncertainty of the model reasonably and efficiently becomes a hot topic today. In this paper, the soil and water assessment tool (SWAT) model is constructed for the study area of China's Feilaixia watershed, and the uncertainty of the runoff simulation is analyzed by GLUE method deeply. Taking the initial parameter range of GLUE method as the research core, the influence of different initial parameter ranges on model uncertainty is studied. In this paper, two sets of parameter ranges are chosen as the object of study, the first one (range 1) is recommended by SWAT-CUP and the second one (range 2) is calibrated by SUFI-2. The results showed that under the same number of simulations (10,000 times), the overall uncertainty obtained by the range 2 is less than the range 1. Specifically, the "behavioral" parameter sets for the range 2 is 10000 and for the range 1 is 4448. In the calibration and the validation, the ratio of P-factor to R-factor for range 1 is 1.387 and 1.391, and for range 2 is 1.405 and 1.462 respectively. In addition, the simulation result of range 2 is better with the NS and R2 slightly higher than range 1. Therefore, it can be concluded that using the parameter range calibrated by SUFI-2 as the initial parameter range for the GLUE is a way to effectively capture and evaluate the simulation uncertainty.

  1. Aplicación del modelo hidrológico-swat-en una microcuenca agrícola de La Pampa ondulada Application of the hydrologic model - swat - on a micro agricultural basin of the rolling Pampa

    Directory of Open Access Journals (Sweden)

    Felipe Behrends Kraemer

    2011-07-01

    Full Text Available El modelado hidrológico es a menudo el primer paso en el desarrollo de sistemas de decisión espacial para identificaráreas vulnerables a la contaminación por nutrientes, pesticidas así como también a contaminantes biológicos. En este sentido el SWAT (Soil and Water Assesment Tool fue desarrollado para predecir impactos de las prácticas de manejo de las tierras en las aguas, sedimentos y agroquímicos en cuencas hidrográficas con diferentes suelos, usos y prácticas en largos períodos de tiempo. Aunque el mismo está siendo aplicado en todo el mundo, todavía no esta difundido su uso en la Argentina, no encontrándose al momento reportes al respecto. Este modelo se utilizó en una microcuenca agrícola de la Pampa Ondulada (Argentina y fue calibrado y validado utilizando los valores de escurrimientos medidos in situ. Se encontraron buenas eficiencias a escala diaria (R²: 0,55; R² ENS: 0,52 y pobres a escala mensual (R²: 0,34; R² ENS: 0,04. En la calibración, los escurrimientos fueron sobreestimados en un 31,8% y 32,6% para la escala mensual y diaria respectivamente, mientras que en la validación se sobreestimó un 42,5% para los valores mensuales y un 41,2% para los diarios. La aplicación del SWAT en esta microcuenca agrícola resultó auspiciosa y conduce a la inclusión de dicho modelo en futuros trabajos.A hydrological model is often the first step for the development of spatial decision systems in order to identify vulnerable areas to the pollution by nutrients, pesticides as well as biological contaminants. The SWAT model was developed to predict the impact of land management on water, agrochemicals and sediments in hydrographical basins with different soils, land uses and practices for long time periods. This model is being used all over the world but it has not been applied in Argentina until present. The SWAT model was used in an agricultural microbasin in the Rolling Pampa (Argentina and was calibrated and validated

  2. Quantifying the Contribution of On-Site Wastewater Treatment Systems to Stream Discharge Using the SWAT Model.

    Science.gov (United States)

    Oliver, C W; Radcliffe, D E; Risse, L M; Habteselassie, M; Mukundan, R; Jeong, J; Hoghooghi, N

    2014-03-01

    In the southeastern United States, on-site wastewater treatment systems (OWTSs) are widely used for domestic wastewater treatment. The degree to which OWTSs represent consumptive water use has been questioned in Georgia. The goal of this study was to estimate the effect of OWTSs on streamflow in a gauged watershed in Gwinnett County, Georgia using the Soil and Water Assessment Tool (SWAT) watershed-scale model, which includes a new OWTS algorithm. Streamflow was modeled with and without the presence of OWTSs. The model was calibrated using data from 1 Jan. 2003 to 31 Dec. 2006 and validated from 1 Jan. 2007 to 31 Dec. 2010 using the auto-calibration tool SWAT-CUP 4. The daily and monthly streamflow Nash-Sutcliffe coefficients were 0.49 and 0.71, respectively, for the calibration period and 0.37 and 0.68, respectively, for the validation period, indicating a satisfactory fit. Analysis of water balance output variables between simulations showed a 3.1% increase in total water yield at the watershed scale and a 5.9% increase at the subbasin scale for a high-density OWTS area. The percent change in water yield between simulations was the greatest in dry years, implying that the influence of OWTSs on the water yield is greatest under drought conditions. Mean OWTS water use was approximately 5.7% consumptive, contrary to common assumptions by water planning agencies in Georgia. Results from this study may be used by OWTS users and by watershed planners to understand the influence of OWTSs on water quantity within watersheds in this region. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  3. Hydrological simulation in a basin of typical tropical climate and soil using the SWAT model part I: Calibration and validation tests

    Directory of Open Access Journals (Sweden)

    Donizete dos R. Pereira

    2016-09-01

    New hydrological insights: The SWAT model was qualified for simulating the Pomba River sub-basin in the sites where rainfall representation was reasonable to good. The model can be used in the simulation of maximum, average and minimum annual daily streamflow based on the paired t-test, contributing with the water resources management of region, although the model still needs to be improved, mainly in the representativeness of rainfall, to give better estimates of extreme values.

  4. PATHOGEN TRANSPORT AND FATE MODELING IN THE UPPER SALEM RIVER WATERSHED USING SWAT MODEL - PEER-REVIEWED JOURNAL ARTICLE

    Science.gov (United States)

    Simulation of the fate and transport of pathogen contamination was conducted with SWAT for the Upper Salem River Watershed, located in Salem County, New Jersey. This watershed is 37 km2 and land uses are predominantly agricultural. The watershed drains to a 32 km str...

  5. Application of the SWAT model to an endorheic watershed in the Central Spanish Pre-Pyrenees: Methodological approach and preliminary results

    Science.gov (United States)

    Gaspar, Leticia; White, Sue; Navas, Ana; López-Vicente, Manuel; Palazón, Leticia

    2013-04-01

    Modelling runoff and sediment transport at watershed scale are key tools to predict hydrological and sediment processes, identify soil sediment sources and estimate sediment yield, with the purpose of better managing soil and water resources. This study aims to apply the SWAT model in an endorheic watershed in the Central Spanish Pre-Pyrenees, where there have been a number of previous field-based studies on sediment sources and transfers. The Soil and Water Assessment Tool (SWAT) is a process based semi-distributed watershed scale hydrologic model, which can provide a high level of spatial detail by allowing the watershed to be divided into sub-basins. This study addresses the challenge of applying the SWAT model to an endorheic watershed that drains to a central lake, without external output, and without a network of permanent rivers. In this case it has been shown that the SWAT model does not correctly reproduce the stream network when using automatic watershed delineation, even with a high resolution Digital Elevation Model (5 x 5 metres). For this purpose, different approaches needed to be considered, such as i) user-defined watersheds and streams, ii) burning in a stream network or iii) modelling each sub-watershed separately. The objective of this study was to develop a new methodological approach for correctly simulating the main hydrological processes in an endorheic and complex karst watershed of the Spanish Pre-Pyrenees. The Estanque de Arriba Lake watershed (74 ha) is an endorheic system located in the Spanish Central Pre-Pyrenees. This watershed holds a small and permanent lake of fresh water (1.7 ha) and is a Site of Community Importance (European NATURA 2000 network). The study area is characterized by an abrupt topography with altitude range between 679 and 862 m and an average slope gradient of 24 %. Steep slopes (> 24 %) occupy the northern part of the watershed, whereas gentle slopes (

  6. Integrated burnup calculation code system SWAT

    International Nuclear Information System (INIS)

    Suyama, Kenya; Hirakawa, Naohiro; Iwasaki, Tomohiko.

    1997-11-01

    SWAT is an integrated burnup code system developed for analysis of post irradiation examination, transmutation of radioactive waste, and burnup credit problem. It enables us to analyze the burnup problem using neutron spectrum depending on environment of irradiation, combining SRAC which is Japanese standard thermal reactor analysis code system and ORIGEN2 which is burnup code widely used all over the world. SWAT makes effective cross section library based on results by SRAC, and performs the burnup analysis with ORIGEN2 using that library. SRAC and ORIGEN2 can be called as external module. SWAT has original cross section library on based JENDL-3.2 and libraries of fission yield and decay data prepared from JNDC FP Library second version. Using these libraries, user can use latest data in the calculation of SWAT besides the effective cross section prepared by SRAC. Also, User can make original ORIGEN2 library using the output file of SWAT. This report presents concept and user's manual of SWAT. (author)

  7. Evaluation of non-point source pollution reduction by applying best management practices using a SWAT model and QuickBird high resolution satellite imagery.

    Science.gov (United States)

    Lee, MiSeon; Park, GeunAe; Park, MinJi; Park, JongYoon; Lee, JiWan; Kim, SeongJoon

    2010-01-01

    This study evaluated the reduction effect of non-point source pollution by applying best management practices (BMPs) to a 1.21 km2 small agricultural watershed using a SWAT (Soil and Water Assessment Tool) model. Two meter QuickBird land use data were prepared for the watershed. The SWAT was calibrated and validated using daily streamflow and monthly water quality (total phosphorus (TP), total nitrogen (TN), and suspended solids (SS)) records from 1999 to 2000 and from 2001 to 2002. The average Nash and Sutcliffe model efficiency was 0.63 for the streamflow and the coefficients of determination were 0.88, 0.72, and 0.68 for SS, TN, and TP, respectively. Four BMP scenarios viz. the application of vegetation filter strip and riparian buffer system, the regulation of Universal Soil Loss Equation P factor, and the fertilizing control amount for crops were applied and analyzed.

  8. Comparative analyses of hydrological responses of two adjacent watersheds to climate variability and change using the SWAT model

    Science.gov (United States)

    Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M.; McCarty, Gregory W.; Hively, Wells; Lang, Megan W.; Sharifi, Amir

    2018-01-01

    Water quality problems in the Chesapeake Bay Watershed (CBW) are expected to be exacerbated by climate variability and change. However, climate impacts on agricultural lands and resultant nutrient loads into surface water resources are largely unknown. This study evaluated the impacts of climate variability and change on two adjacent watersheds in the Coastal Plain of the CBW, using the Soil and Water Assessment Tool (SWAT) model. We prepared six climate sensitivity scenarios to assess the individual impacts of variations in CO2concentration (590 and 850 ppm), precipitation increase (11 and 21 %), and temperature increase (2.9 and 5.0 °C), based on regional general circulation model (GCM) projections. Further, we considered the ensemble of five GCM projections (2085–2098) under the Representative Concentration Pathway (RCP) 8.5 scenario to evaluate simultaneous changes in CO2, precipitation, and temperature. Using SWAT model simulations from 2001 to 2014 as a baseline scenario, predicted hydrologic outputs (water and nitrate budgets) and crop growth were analyzed. Compared to the baseline scenario, a precipitation increase of 21 % and elevated CO2 concentration of 850 ppm significantly increased streamflow and nitrate loads by 50 and 52 %, respectively, while a temperature increase of 5.0 °C reduced streamflow and nitrate loads by 12 and 13 %, respectively. Crop biomass increased with elevated CO2 concentrations due to enhanced radiation- and water-use efficiency, while it decreased with precipitation and temperature increases. Over the GCM ensemble mean, annual streamflow and nitrate loads showed an increase of  ∼  70 % relative to the baseline scenario, due to elevated CO2 concentrations and precipitation increase. Different hydrological responses to climate change were observed from the two watersheds, due to contrasting land use and soil characteristics. The watershed with a larger percent of croplands demonstrated a greater

  9. Comparative analyses of hydrological responses of two adjacent watersheds to climate variability and change using the SWAT model

    Science.gov (United States)

    Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M.; McCarty, Gregory W.; Hively, Wells D.; Lang, Megan W.; Sharifi, Amir

    2018-01-01

    Water quality problems in the Chesapeake Bay Watershed (CBW) are expected to be exacerbated by climate variability and change. However, climate impacts on agricultural lands and resultant nutrient loads into surface water resources are largely unknown. This study evaluated the impacts of climate variability and change on two adjacent watersheds in the Coastal Plain of the CBW, using the Soil and Water Assessment Tool (SWAT) model. We prepared six climate sensitivity scenarios to assess the individual impacts of variations in CO2 concentration (590 and 850 ppm), precipitation increase (11 and 21 %), and temperature increase (2.9 and 5.0 °C), based on regional general circulation model (GCM) projections. Further, we considered the ensemble of five GCM projections (2085-2098) under the Representative Concentration Pathway (RCP) 8.5 scenario to evaluate simultaneous changes in CO2, precipitation, and temperature. Using SWAT model simulations from 2001 to 2014 as a baseline scenario, predicted hydrologic outputs (water and nitrate budgets) and crop growth were analyzed. Compared to the baseline scenario, a precipitation increase of 21 % and elevated CO2 concentration of 850 ppm significantly increased streamflow and nitrate loads by 50 and 52 %, respectively, while a temperature increase of 5.0 °C reduced streamflow and nitrate loads by 12 and 13 %, respectively. Crop biomass increased with elevated CO2 concentrations due to enhanced radiation- and water-use efficiency, while it decreased with precipitation and temperature increases. Over the GCM ensemble mean, annual streamflow and nitrate loads showed an increase of ˜ 70 % relative to the baseline scenario, due to elevated CO2 concentrations and precipitation increase. Different hydrological responses to climate change were observed from the two watersheds, due to contrasting land use and soil characteristics. The watershed with a larger percent of croplands demonstrated a greater increased rate of 5.2 kg N ha-1 in

  10. A new R-SWAT Decision Making Framework for the Efficient Allocation of Best Management Practices

    OpenAIRE

    UDIAS MOINELO ANGEL; MALAGO ANNA; REYNAUD ARNAUD; PASTORI MARCO; VIGIAK OLGA; BOURAOUI Faycal

    2015-01-01

    The work presents and illustrates the application of R-SWAT-DM, a new R framework designed for Decision Making (DM), related to the implementation of Best Management Practices (BMPs), for restoring and protecting the good ecological status of freshwater bodies. R-SWAT-DM combines the use of the SWAT watershed model, the spatial representation of BMPs and an economic component. The SWAT model served as the nonpoint source pollution estimator for current conditions (base line) as well as for sc...

  11. Calibration and validation of SWAT model for estimating water balance and nitrogen losses in a small agricultural watershed in central Poland

    Directory of Open Access Journals (Sweden)

    Smarzyńska Karolina

    2016-06-01

    Full Text Available Soil and Water Assessment Tool (SWAT ver. 2005 was applied to study water balance and nitrogen load pathways in a small agricultural watershed in the lowlands of central Poland. The natural flow regime of the Zgłowiączka River was strongly modified by human activity (deforestation and installation of a subsurface drainage system to facilitate stable crop production. SWAT was calibrated for daily and monthly discharge and monthly nitrate nitrogen load. Model efficiency was tested using manual techniques (subjective and evaluation statistics (objective. Values of Nash–Sutcliffe efficiency coefficient (NSE, coefficient of determination (R2 and percentage of bias for daily/monthly discharge simulations and monthly load indicated good or very good fit of simulated discharge and nitrate nitrogen load to the observed data set. Model precision and accuracy of fit was proved in validation. The calibrated and validated SWAT was used to assess water balance and nitrogen fluxes in the watershed. According to the results, the share of tile drainage in water yield is equal to 78%. The model analysis indicated the most significant pathway of NO3-N to surface waters in the study area, namely the tile drainage combined with lateral flow. Its share in total NO3-N load amounted to 89%. Identification of nitrogen fluxes in the watershed is crucial for decision makers in order to manage water resources and to implement the most effective measures to limit diffuse pollution from arable land to surface waters.

  12. Evaluation of drought impact on groundwater recharge rate using SWAT and Hydrus models on an agricultural island in western Japan

    Directory of Open Access Journals (Sweden)

    G. Jin

    2015-06-01

    Full Text Available Clarifying the variations of groundwater recharge response to a changing non-stationary hydrological process is important for efficiently managing groundwater resources, particularly in regions with limited precipitation that face the risk of water shortage. However, the rate of aquifer recharge is difficult to evaluate in terms of large annual-variations and frequency of flood events. In our research, we attempt to simulate related groundwater recharge processes under variable climate conditions using the SWAT Model, and validate the groundwater recharge using the Hydrus Model. The results show that annual average groundwater recharge comprised approximately 33% of total precipitation, however, larger variation was found for groundwater recharge and surface runoff compared to evapotranspiration, which fluctuated with annual precipitation variations. The annual variation of groundwater resources is shown to be related to precipitation. In spatial variations, the upstream is the main surface water discharge area; the middle and downstream areas are the main groundwater recharge areas. Validation by the Hydrus Model shows that the estimated and simulated groundwater levels are consistent in our research area. The groundwater level shows a quick response to the groundwater recharge rate. The rainfall intensity had a great impact on the changes of the groundwater level. Consequently, it was estimated that large spatial and temporal variation of the groundwater recharge rate would be affected by precipitation uncertainty in future.

  13. Spatiotemporal impacts of LULC changes on hydrology from the perspective of runoff generation mechanism using SWAT model with evolving parameters

    Science.gov (United States)

    Li, Y.; Chang, J.; Luo, L.

    2017-12-01

    It is of great importance for water resources management to model the truly hydrological process under changing environment, especially under significant changes of underlying surfaces like the Wei River Bain (WRB) where the subsurface hydrology is highly influenced by human activities, and to systematically investigate the interactions among LULC change, streamflow variation and changes in runoff generation process. Therefore, we proposed the idea of evolving parameters in hydrological model (SWAT) to reflect the changes in physical environment with different LULC conditions. Then with these evolving parameters, the spatiotemporal impacts of LULC changes on streamflow were quantified, and qualitative analysis was conducted to further explore how LULC changes affect the streamflow from the perspective of runoff generation mechanism. Results indicate the following: 1) evolving parameter calibration is not only effective but necessary to ensure the validity of the model when dealing with significant changes in underlying surfaces due to human activities. 2) compared to the baseline period, the streamflow in wet seasons increased in the 1990s but decreased in the 2000s. While at yearly and dry seasonal scales, the streamflow decreased in both two decades; 3) the expansion of cropland is the major contributor to the reduction of surface water component, thus causing the decline in streamflow at yearly and dry seasonal scales. While compared to the 1990s, the expansions of woodland in the middle stream and grassland in the downstream are the main stressors that increased the soil water component, thus leading to the more decline of the streamflow in the 2000s.

  14. Hydrological modeling of the pipestone creek watershed using the Soil Water Assessment Tool (SWAT: Assessing impacts of wetland drainage on hydrology

    Directory of Open Access Journals (Sweden)

    Cesar Perez-Valdivia

    2017-12-01

    Full Text Available Study region: Prairie Pothole Region of North America. Study focus: The Prairie Pothole Region of North America has experienced extensive wetland drainage, potentially impacting peak flows and annual flow volumes. Some of this drainage has occurred in closed basins, possibly impacting lake water levels of these systems. In this study we investigated the potential impact of wetland drainage on peak flows and annual volumes in a 2242 km2 watershed located in southeastern Saskatchewan (Canada using the Soil Water Assessment Tool (SWAT model. New hydrological insights: The SWAT model, which had been calibrated and validated at daily and monthly time steps for the 1997–2009 period, was used to assess the impact of wetland drainage using three hypothetical scenarios that drained 15, 30, and 50% of the non-contributing drainage area. Results of these simulations suggested that drainage increased spring peak flows by about 50, 79 and 113%, respectively while annual flow volumes increased by about 43, 68, and 98% in each scenario. Years that were wetter than normal presented increased peak flows and annual flow volumes below the average of the simulated period. Alternatively, summer peak flows presented smaller increases in terms of percentages during the simulated period. Keywords: Soil Water Assessment Tool (SWAT, Wetland drainage, Peak flow, Annual volume, Prairie Pothole Region

  15. The Assessment of Green Water Based on the SWAT Model: A Case Study in the Hai River Basin, China

    Directory of Open Access Journals (Sweden)

    Kui Zhu

    2018-06-01

    Full Text Available Green water accounts for two-thirds of precipitation, and the proportion could be even higher in dry years. Conflicts between water supply and demand have gradually become severe in the Hai River Basin (HRB due to the socio-economic development. Thus, the exploitation and the utilization of green water have attracted increasing attention. By gathering the related hydrological, meteorological, and geographic data, the spatiotemporal distribution of green water in HRB and the impacts of land use types on green water are analyzed based on the SWAT (Soil and Water Assessment Tool model in this study. Furthermore, three new indices are proposed for evaluation, including the maximum possible storage of green water (MSGW, the consumed green water (CGW, and the utilizable green water (UGW. The results show that (1 the MSGW is relatively low in plain areas and its spatial distribution is significantly associated with the soil type; (2 according to the evaluation results of CGW and UGW in HRB, a further improvement of utilization efficiency of green water could be achieved; (3 in general, the utilization efficiency of precipitation in farmlands is higher than other land use types, which means that the planting of appropriate plants could be helpful to enhance the utilization efficiency of green water. Our results summarize the spatiotemporal distribution of green water resource and provide a reference for water resources management in other water-short agricultural areas.

  16. Assessing the impacts of sustainable agricultural practices for water quality improvements in the Vouga catchment (Portugal) using the SWAT model.

    Science.gov (United States)

    Rocha, João; Roebeling, Peter; Rial-Rivas, María Ermitas

    2015-12-01

    The extensive use of fertilizers has become one of the most challenging environmental issues in agricultural catchment areas. In order to reduce the negative impacts from agricultural activities and to accomplish the objectives of the European Water Framework Directive we must consider the implementation of sustainable agricultural practices. In this study, we assess sustainable agricultural practices based on reductions in N-fertilizer application rates (from 100% to 0%) and N-application methods (single, split and slow-release) across key agricultural land use classes in the Vouga catchment, Portugal. The SWAT model was used to relate sustainable agricultural practices, agricultural yields and N-NO3 water pollution deliveries. Results show that crop yields as well as N-NO3 exportation rates decrease with reductions in N-application rates and single N-application methods lead to lower crop yields and higher N-NO3 exportation rates as compared to split and slow-release N-application methods. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Case Study: Effect of Climatic Characterization on River Discharge in an Alpine-Prealpine Catchment of the Spanish Pyrenees Using the SWAT Model

    Directory of Open Access Journals (Sweden)

    Leticia Palazón

    2016-10-01

    Full Text Available The new challenges in assessment of water resources demand new approaches and tools, such as the use of hydrologic models, which could serve to assist managers in the prediction, planning and management of catchment water supplies in view of increased demand of water for irrigation and climatic change. Good characterization of the spatial patterns of climate variables is of paramount importance in hydrological modelling. This is especially so when modelling mountain environments which are characterized by strong altitudinal climate gradients. However, very often there is a poor distribution of climatic stations in these areas, which in many cases, results in under representation of high altitude areas with respect to climatic data. This results in the poor performance of the models. In the present study, the Soil and Water Assessment Tool (SWAT model was applied to the Barasona reservoir catchment in the Central Spanish Pyrenees in order to assess the influence of different climatic characterizations in the monthly river discharges. Four simulations with different input data were assessed, using only the available climate data (A1; the former plus one synthetic dataset at a higher altitude (B1; and both plus the altitudinal climate gradient (A2 and B2. The model’s performance was evaluated against the river discharges for the representative periods of 2003–2005 and 1994–1996 by means of commonly used statistical measures. The best results were obtained using the altitudinal climate gradient alone (scenario A2. This study provided insight into the importance of taking into account the sources and the spatial distribution of weather data in modelling water resources in mountainous catchments.

  18. Multi-gauge Calibration for modeling the Semi-Arid Santa Cruz Watershed in Arizona-Mexico Border Area Using SWAT

    Science.gov (United States)

    Niraula, Rewati; Norman, Laura A.; Meixner, Thomas; Callegary, James B.

    2012-01-01

    In most watershed-modeling studies, flow is calibrated at one monitoring site, usually at the watershed outlet. Like many arid and semi-arid watersheds, the main reach of the Santa Cruz watershed, located on the Arizona-Mexico border, is discontinuous for most of the year except during large flood events, and therefore the flow characteristics at the outlet do not represent the entire watershed. Calibration is required at multiple locations along the Santa Cruz River to improve model reliability. The objective of this study was to best portray surface water flow in this semiarid watershed and evaluate the effect of multi-gage calibration on flow predictions. In this study, the Soil and Water Assessment Tool (SWAT) was calibrated at seven monitoring stations, which improved model performance and increased the reliability of flow, in the Santa Cruz watershed. The most sensitive parameters to affect flow were found to be curve number (CN2), soil evaporation and compensation coefficient (ESCO), threshold water depth in shallow aquifer for return flow to occur (GWQMN), base flow alpha factor (Alpha_Bf), and effective hydraulic conductivity of the soil layer (Ch_K2). In comparison, when the model was established with a single calibration at the watershed outlet, flow predictions at other monitoring gages were inaccurate. This study emphasizes the importance of multi-gage calibration to develop a reliable watershed model in arid and semiarid environments. The developed model, with further calibration of water quality parameters will be an integral part of the Santa Cruz Watershed Ecosystem Portfolio Model (SCWEPM), an online decision support tool, to assess the impacts of climate change and urban growth in the Santa Cruz watershed.

  19. Water quantity and quality optimization modeling of dams operation based on SWAT in Wenyu River Catchment, China.

    Science.gov (United States)

    Zhang, Yongyong; Xia, Jun; Chen, Junfeng; Zhang, Minghua

    2011-02-01

    Water quantity and quality joint operation is a new mode in the present dams' operation research. It has become a hot topic in governmental efforts toward integrated basin improvement. This paper coupled a water quantity and quality joint operation model (QCmode) and genetic algorithm with Soil and Water Assessment Tool (SWAT). Together, these tools were used to explore a reasonable operation of dams and floodgates at the basin scale. Wenyu River Catchment, a key area in Beijing, was selected as the case study. Results showed that the coupled water quantity and quality model of Wenyu River Catchment more realistically simulates the process of water quantity and quality control by dams and floodgates. This integrated model provides the foundation for research of water quantity and quality optimization on dam operation in Wenyu River Catchment. The results of this modeling also suggest that current water quality of Wenyu River will improve following the implementation of the optimized operation of the main dams and floodgates. By pollution control and water quantity and quality joint operation of dams and floodgates, water quality of Wenyu river will change significantly, and the available water resources will increase by 134%, 32%, 17%, and 82% at the downstream sites of Sha River Reservoir, Lutong Floodgate, Xinpu Floodgate, and Weigou Floodgate, respectively. The water quantity and quality joint operation of dams will play an active role in improving water quality and water use efficiency in Wenyu River Basin. The research will provide the technical support for water pollution control and ecological restoration in Wenyu River Catchment and could be applied to other basins with large number of dams. Its application to the Wenyu River Catchment has a great significance for the sustainable economic development of Beijing City.

  20. ESTIMATIVA DO BALANÇO SEDIMENTAR DA BACIA DO RIO TIJUCAS (SC-BRASIL A PARTIR DA APLICAÇÃO DO MODELO HIDROLÓGICO SWAT / ESTIMATE OF SEDIMENT BUDGET OF THE TIJUCAS RIVER BASIN APPLYING SWAT HYDROLOGIC MODEL

    Directory of Open Access Journals (Sweden)

    Jean Berná Paim

    2009-12-01

    Full Text Available Adopt a basin as a hydrological unit to understand the physical processes related to the water and sediment production is important because its characteristics (area, shape and topography can determine its use in a sustainable manner. This study is aim in the test of the applicability of hydrologic model SWAT (Soil and Water Assessment Tool in the Tijucas River Basin to quantify the water and sediment production along it sub-basins. Together, geoprocessing techniques were applied with the creation of a database of geographical information to describe the region. On this database is included the daily precipitation an temperature data of the gauges distributed on the watershed, soil data, a land use map and the digital elevation model (DEM to create the Hydrologic Response Units (HRU’s. A time series with flow values and sediment concentration measured are very important to calibrate and validate the model output parameters. After the calibration of the initial results, the Flow Gauge number 102 presented a Nash and Sutcliffe Coefficient - COE = 0.6 indicating a good adjust of the model. The results were used to create a sediment production map for Tijucas River Basin, when the 10 years average ranged between 0.5 ton/ha and 9.0 ton/ha in some sub-basins.

  1. Evaluating Impacts of climate and land use changes on streamflow using SWAT and land use models based CESM1-CAM5 Climate scenarios

    Science.gov (United States)

    Lin, Tzu Ping; Lin, Yu Pin; Lien, Wan Yu

    2015-04-01

    Climate change projects have various levels of impacts on hydrological cycles around the world. The impact of climate change and uncertainty of climate projections from general circulation models (GCMs) from the Coupled Model Intercomparison Project (CMIP5) which has been just be released in Taiwan, 2014. Since the streamflow run into ocean directly due to the steep terrain and the rainfall difference between wet and dry seasons is apparent; as a result, the allocation water resource reasonable is very challenge in Taiwan, particularly under climate change. The purpose of this study was to evaluate the impacts of climate and land use changes on a small watershed in Taiwan. The AR5 General Circulation Models(GCM) output data was adopted in this study and was downscaled from the monthly to the daily weather data as the input data of hydrological model such as Soil and Water Assessment Tool (SWAT) model in this study. The spatially explicit land uses change model, the Conservation of Land Use and its Effects at Small regional extent (CLUE-s), was applied to simulate land use scenarios in 2020-2039. Combined climate and land use change scenarios were adopted as input data of the hydrological model, the SWAT model, to estimate the future streamflows. With the increasing precipitation, increasing urban area and decreasing agricultural and grass land, the annual streamflow in the most of twenty-three subbasins were also increased. Besides, due to the increasing rainfall in wet season and decreasing rainfall in dry season, the difference of streamflow between wet season and dry season are also increased. This result indicates a more stringent challenge on the water resource management in future. Therefore, impacts on water resource caused by climate change and land use change should be considered in water resource planning for the Datuan river watershed. Keywords: SWAT, GCM, CLUE-s, streamflow, climate change, land use change

  2. Application of the SWAT model to an AMD-affected river (Meca River, SW Spain). Estimation of transported pollutant load

    Science.gov (United States)

    Galván, L.; Olías, M.; Fernandez de Villarán, R.; Domingo Santos, J. M.; Nieto, J. M.; Sarmiento, A. M.; Cánovas, C. R.

    2009-10-01

    SummaryThe Meca River is highly contaminated by acid mine drainage coming from the Tharsis mining district, belonging to the Iberian Pyrite Belt. This river is regulated by the Sancho reservoir (58 hm 3), with a pH close to 4.2. In this work, the load transported by the Meca River to the Sancho reservoir has been assessed. Due to the lack of streamflow data, the hydrological behaviour of the Meca River basin has been simulated using the SWAT model. The model has been calibrated against registered daily inflows of the Sancho reservoir (1982-2000), excluding the hydrological years 2000/2001 and 2001/2002 that were kept for the validation. The results were satisfactory; the evaluation coefficients for monthly calibration were: r = 0.85 (Pearson's correlation coefficient), NSE = 0.83 (Nash-Sutcliffe coefficient) and DV = 1.08 (runoff volume deviation). The main uncertainty was the calibration during low water because of the poor accuracy in the measurement of the inputs to the reservoir in these conditions. Discharge and dissolved concentration relationships for different elements were obtained from hydrochemical samplings, which allowed us to estimate the element pollutant load transported to the reservoir: 418 ton/year of Al, 8024 ton/year of SO 4, 121 ton/year of Zn, etc. Based on these loads, concentrations in the reservoir were calculated for some elements. Apart from Mn and Sr, good adjustment between calculated and measured values was observed (±20% for Ca, Co, Li, Mg, Na, Ni, Zn and SO 4). Capsule: Hydrological model combined with water quality data show how pollution by AMD can generate huge loads of contaminants acidifying streams and reservoirs.

  3. Future water availability in the largest freshwater Mediterranean lake is at great risk as evidenced from simulations with the SWAT model.

    Science.gov (United States)

    Bucak, Tuba; Trolle, Dennis; Andersen, Hans Estrup; Thodsen, Hans; Erdoğan, Şeyda; Levi, Eti E; Filiz, Nur; Jeppesen, Erik; Beklioğlu, Meryem

    2017-03-01

    Inter- and intra-annual water level fluctuations and changes in water flow regime are intrinsic characteristics of Mediterranean lakes. Additionally, considering climate change projections for the water-limited Mediterranean region, increased air temperatures and decreased precipitation are anticipated, leading to dramatic declines in lake water levels as well as severe water scarcity problems. The study site, Lake Beyşehir, the largest freshwater lake in the Mediterranean basin, is - like other Mediterranean lakes - threatened by climatic changes and over-abstraction of water for irrigated crop farming. Therefore, implementation of strict water level management policies is required. In this study, an integrated modeling approach was used to predict the future water levels of Lake Beyşehir in response to potential future changes in climate and land use. Water level estimation was performed by linking the catchment model Soil and Water Assessment Tool (SWAT) with a Support Vector Regression model (ε-SVR). The projected increase in temperature and decrease in precipitation based on the climate change models led to an enhanced potential evapotranspiration and reduced total runoff. On the other hand, the effects of various land use scenarios within the catchment appeared to be comparatively insignificant. According to the ε-SVR model results, changes in hydrological processes caused a water level reduction for all scenarios. Moreover, the MPI-ESM-MR General Circulation Model outputs produced the most dramatic results by predicting that Lake Beyşehir may dry out by the 2040s with the current outflow regime. The results indicate that shallow Mediterranean lakes may face a severe risk of drying out and losing their ecosystem values in the near future if the current intensity of water abstraction is not reduced. In addition, the results also demonstrate that outflow management and sustainable use of water sources are vital to sustain lake ecosystems in water

  4. Hydrology and sediment yield calibration for the Barasona reservoir catchment (Spain) using SWAT

    Science.gov (United States)

    Palazón, Leticia; Navas, Ana

    2013-04-01

    Hydrological and soil erosion models, as Soil and Water Assessment Tool (SWAT), have become very useful tools and increasingly serve as vital components of integrated environmental assessments that provide information outside of direct field experiments and causal observation. The purpose of this study was to improve the calibration of SWAT model to use it in an alpine catchment as a simulator of processes related to water quality and soil erosion. SWAT is spatially semi-distributed, agro-hydrological model that operates on a daily time step (as a minimum) at basin scale. It is designed to predict the impact of management on water, sediment and agricultural chemical yields in ungaged catchments. SWAT provides physically based algorithms as an option to define many of the important components of the hydrologic cycle. The input requirements of the model are used to describe the climate, soil properties, topography, vegetation, and land management practices. SWAT analyzes small or large catchments by discretising into sub-basins, which are then further subdivided into hydrological response units (HRUs) with homogeneous land use, soil type and slope. SWAT model (SWAT2009) coupled with a GIS interface (ArcSWAT), was applied to the Barasona reservoir catchment located in the central Spanish Pyrenees. The 1509 km2 agro-forestry catchment presents a mountain type climate, an altitudinal range close to 3000 meters and a precipitation variation close to 1000 mm/km. The mountainous characteristics of the catchment, in addition to the scarcity of climate data in the region, require specific calibration for some processes. Snowfall and snowmelt are significant processes in the hydrologic regime of the area and were calibrated in a previous work. In this work some of the challenges of the catchment to model with SWAT which affected the hydrology and the sediment yield simulation were performed as improvement of the previous calibration. Two reservoirs, a karst system which

  5. Macrophyte growth module for the SWAT model – impact of climate change and management on stream ecology

    DEFF Research Database (Denmark)

    Lu, Shenglan; Trolle, Dennis; Erfurt, Jytte

    To access how multiple stressors affect the water quantity and quality and stream ecology at catchment scale under various management and climate change scenarios, we implemented macrophyte growth modules for the Soil and Water Assessment Tool version 2012 (SWAT). The macrophyte growth module...

  6. Integrated Approach to Inform the New York City Water Supply System Coupling SAR Remote Sensing Observations and the SWAT Watershed Model

    Science.gov (United States)

    Tesser, D.; Hoang, L.; McDonald, K. C.

    2017-12-01

    Efforts to improve municipal water supply systems increasingly rely on an ability to elucidate variables that drive hydrologic dynamics within large watersheds. However, fundamental model variables such as precipitation, soil moisture, evapotranspiration, and soil freeze/thaw state remain difficult to measure empirically across large, heterogeneous watersheds. Satellite remote sensing presents a method to validate these spatially and temporally dynamic variables as well as better inform the watershed models that monitor the water supply for many of the planet's most populous urban centers. PALSAR 2 L-band, Sentinel 1 C-band, and SMAP L-band scenes covering the Cannonsville branch of the New York City (NYC) water supply watershed were obtained for the period of March 2015 - October 2017. The SAR data provides information on soil moisture, free/thaw state, seasonal surface inundation, and variable source areas within the study site. Integrating the remote sensing products with watershed model outputs and ground survey data improves the representation of related processes in the Soil and Water Assessment Tool (SWAT) utilized to monitor the NYC water supply. PALSAR 2 supports accurate mapping of the extent of variable source areas while Sentinel 1 presents a method to model the timing and magnitude of snowmelt runoff events. SMAP Active Radar soil moisture product directly validates SWAT outputs at the subbasin level. This blended approach verifies the distribution of soil wetness classes within the watershed that delineate Hydrologic Response Units (HRUs) in the modified SWAT-Hillslope. The research expands the ability to model the NYC water supply source beyond a subset of the watershed while also providing high resolution information across a larger spatial scale. The global availability of these remote sensing products provides a method to capture fundamental hydrology variables in regions where current modeling efforts and in situ data remain limited.

  7. Comparison of MODIS and SWAT evapotranspiration over a complex terrain at different spatial scales

    Science.gov (United States)

    Abiodun, Olanrewaju O.; Guan, Huade; Post, Vincent E. A.; Batelaan, Okke

    2018-05-01

    In most hydrological systems, evapotranspiration (ET) and precipitation are the largest components of the water balance, which are difficult to estimate, particularly over complex terrain. In recent decades, the advent of remotely sensed data based ET algorithms and distributed hydrological models has provided improved spatially upscaled ET estimates. However, information on the performance of these methods at various spatial scales is limited. This study compares the ET from the MODIS remotely sensed ET dataset (MOD16) with the ET estimates from a SWAT hydrological model on graduated spatial scales for the complex terrain of the Sixth Creek Catchment of the Western Mount Lofty Ranges, South Australia. ET from both models was further compared with the coarser-resolution AWRA-L model at catchment scale. The SWAT model analyses are performed on daily timescales with a 6-year calibration period (2000-2005) and 7-year validation period (2007-2013). Differences in ET estimation between the SWAT and MOD16 methods of up to 31, 19, 15, 11 and 9 % were observed at respectively 1, 4, 9, 16 and 25 km2 spatial resolutions. Based on the results of the study, a spatial scale of confidence of 4 km2 for catchment-scale evapotranspiration is suggested in complex terrain. Land cover differences, HRU parameterisation in AWRA-L and catchment-scale averaging of input climate data in the SWAT semi-distributed model were identified as the principal sources of weaker correlations at higher spatial resolution.

  8. Algorithm Theory - SWAT 2006

    DEFF Research Database (Denmark)

    This book constitutes the refereed proceedings of the 10th Scandinavian Workshop on Algorithm Theory, SWAT 2006, held in Riga, Latvia, in July 2006. The 36 revised full papers presented together with 3 invited papers were carefully reviewed and selected from 154 submissions. The papers address all...

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

    Science.gov (United States)

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

  10. Improving SWAT model prediction using an upgraded denitrification scheme and constrained auto calibration

    Science.gov (United States)

    The reliability of common calibration practices for process based water quality models has recently been questioned. A so-called “adequately calibrated model” may contain input errors not readily identifiable by model users, or may not realistically represent intra-watershed responses. These short...

  11. How to constrain multi-objective calibrations of the SWAT model using water balance components

    Science.gov (United States)

    Automated procedures are often used to provide adequate fits between hydrologic model estimates and observed data. While the models may provide good fits based upon numeric criteria, they may still not accurately represent the basic hydrologic characteristics of the represented watershed. Here we ...

  12. Improved simulation of river water and groundwater exchange in an alluvial plain using the SWAT model

    Science.gov (United States)

    Hydrological interaction between surface and subsurface water systems has a significant impact on water quality, ecosystems and biogeochemistry cycling of both systems. Distributed models have been developed to simulate this function, but they require detailed spatial inputs and extensive computati...

  13. Evaluating the SWAT model for a low-gradient forested watershed in coastal South Carolina

    Science.gov (United States)

    D.M. Amatya; M.K. Jha.

    2011-01-01

    Modeling the hydrology of low�]gradient forested watersheds on shallow, poorly drained soils of the coastal plain is a challenging task due to complexities in watershed delineation, microtopography, evapotranspiration, runoff generation processes and pathways including flooding and submergence caused by tropical storms, and complexity of vegetation species....

  14. Problems and Prospects of SWAT Model Application on an Arid/Semi-arid Watershed in Arizona

    Science.gov (United States)

    Hydrological characteristics in the semi-arid southwest create unique challenges to watershed modelers. Streamflow in these regions is largely dependent on seasonal, short term, and high intensity rainfall events. The objectives of this study are: 1) to analyze the unique hydrolo...

  15. Evaluation of Gridded Precipitation Data for Driving SWAT Model in Area Upstream of Three Gorges Reservoir

    Science.gov (United States)

    Yang, Yan; Wang, Guoqiang; Wang, Lijing; Yu, Jingshan; Xu, Zongxue

    2014-01-01

    Gridded precipitation data are becoming an important source for driving hydrologic models to achieve stable and valid simulation results in different regions. Thus, evaluating different sources of precipitation data is important for improving the applicability of gridded data. In this study, we used three gridded rainfall datasets: 1) National Centers for Environmental Prediction - Climate Forecast System Reanalysis (NCEP-CFSR); 2) Asian Precipitation - Highly-Resolved Observational Data Integration Towards Evaluation (APHRODITE); and 3) China trend - surface reanalysis (trend surface) data. These are compared with monitoring precipitation data for driving the Soil and Water Assessment Tool in two basins upstream of Three Gorges Reservoir (TGR) in China. The results of one test basin with significant topographic influence indicates that all the gridded data have poor abilities in reproducing hydrologic processes with the topographic influence on precipitation quantity and distribution. However, in a relatively flat test basin, the APHRODITE and trend surface data can give stable and desirable results. The results of this study suggest that precipitation data for future applications should be considered comprehensively in the TGR area, including the influence of data density and topography. PMID:25409467

  16. Evaluation of gridded precipitation data for driving SWAT model in area upstream of Three Gorges Reservoir.

    Science.gov (United States)

    Yang, Yan; Wang, Guoqiang; Wang, Lijing; Yu, Jingshan; Xu, Zongxue

    2014-01-01

    Gridded precipitation data are becoming an important source for driving hydrologic models to achieve stable and valid simulation results in different regions. Thus, evaluating different sources of precipitation data is important for improving the applicability of gridded data. In this study, we used three gridded rainfall datasets: 1) National Centers for Environmental Prediction-Climate Forecast System Reanalysis (NCEP-CFSR); 2) Asian Precipitation-Highly-Resolved Observational Data Integration Towards Evaluation (APHRODITE); and 3) China trend-surface reanalysis (trend surface) data. These are compared with monitoring precipitation data for driving the Soil and Water Assessment Tool in two basins upstream of Three Gorges Reservoir (TGR) in China. The results of one test basin with significant topographic influence indicates that all the gridded data have poor abilities in reproducing hydrologic processes with the topographic influence on precipitation quantity and distribution. However, in a relatively flat test basin, the APHRODITE and trend surface data can give stable and desirable results. The results of this study suggest that precipitation data for future applications should be considered comprehensively in the TGR area, including the influence of data density and topography.

  17. Calibration of spatially distributed hydrological processes and model parameters in SWAT using remote sensing data and an auto-calibration procedure : A case study in a Vietnamese river basin

    NARCIS (Netherlands)

    Hà, T.L.; Bastiaanssen, W.G.M.; van Griensven, Ann; Van Dijk, Albert I J M; Senay, Gabriel B.

    2018-01-01

    In this paper, evapotranspiration (ET) and leaf area index (LAI) were used to calibrate the SWAT model, whereas remotely sensed precipitation and other climatic parameters were used as forcing data for the 6300 km2 Day Basin, a tributary of the Red River in Vietnam. The efficacy of the Sequential

  18. Critical review of SWAT applications in the upper Nile basin countries

    Directory of Open Access Journals (Sweden)

    A. van Griensven

    2012-09-01

    Full Text Available The Soil and Water Assessment Tool (SWAT is an integrated river basin model that is widely applied within the Nile basin. Up to date, more than 20 peer-reviewed papers describe the use of SWAT for a variety of problems in the upper Nile basin countries, such as erosion modelling, land use and climate change impact modelling and water resources management. The majority of the studies are focused on locations in the tropical highlands in Ethiopia and around Lake Victoria. The popularity of SWAT is attributed to the fact that the tool is freely available and that it is readily applicable through the development of geographic information system (GIS based interfaces and its easy linkage to sensitivity, calibration and uncertainty analysis tools. The online and free availability of basic GIS data that are required for SWAT made its applicability more straightforward even in data-scarce areas. However, the easy use of SWAT may not always lead to appropriate models which is also a consequence of the quality of the available free databases in these regions. In this paper, we aim at critically reviewing the use of SWAT in the context of the modelling purpose and problem descriptions in the tropical highlands of the Nile basin countries. To evaluate the models that are described in journal papers, a number of criteria are used to evaluate the model set-up, model performances, physical representation of the model parameters, and the correctness of the hydrological model balance. On the basis of performance indicators, the majority of the SWAT models were classified as giving satisfactory to very good results. Nevertheless, the hydrological mass balances as reported in several papers contained losses that might not be justified. Several papers also reported the use of unrealistic parameter values. More worrying is that many papers lack this information. For this reason, most of the reported SWAT models have to be evaluated critically. An important gap is

  19. Assessing the impacts of future climate conditions on the effectiveness of winter cover crops in reducing nitrate loads into the Chesapeake Bay Watershed using SWAT model

    Science.gov (United States)

    Lee, Sangchul; Sadeghi, Ali M.; Yeo, In-Young; McCarty, Gregory W.; Hively, W. Dean

    2017-01-01

    Winter cover crops (WCCs) have been widely implemented in the Coastal Plain of the Chesapeake Bay watershed (CBW) due to their high effectiveness at reducing nitrate loads. However, future climate conditions (FCCs) are expected to exacerbate water quality degradation in the CBW by increasing nitrate loads from agriculture. Accordingly, the question remains whether WCCs are sufficient to mitigate increased nutrient loads caused by FCCs. In this study, we assessed the impacts of FCCs on WCC nitrate reduction efficiency on the Coastal Plain of the CBW using Soil and Water Assessment Tool (SWAT) model. Three FCC scenarios (2085 – 2098) were prepared using General Circulation Models (GCMs), considering three Intergovernmnental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) greenhouse gas emission scenarios. We also developed six representative WCC implementation scenarios based on the most commonly used planting dates and species of WCCs in this region. Simulation results showed that WCC biomass increased by ~ 58 % under FCC scenarios, due to climate conditions conducive to the WCC growth. Prior to implementing WCCs, annual nitrate loads increased by ~ 43 % under FCC scenarios compared to the baseline scenario (2001 – 2014). When WCCs were planted, annual nitrate loads were substantially reduced by ~ 48 % and WCC nitrate reduction efficiency water ~ 5 % higher under FCC scenarios relative to the baseline. The increase rate of WCC nitrate reduction efficiency varied by FCC scenarios and WCC planting methods. As CO2 concentration was higher and winters were warmer under FCC scenarios, WCCs had greater biomass and therefore showed higher nitrate reduction efficiency. In response to FCC scenarios, the performance of less effective WCC practices (e.g., barley, wheat, and late planting) under the baseline indicated ~ 14 % higher increase rate of nitrate reduction efficiency compared to ones with better effectiveness under the baseline (e

  20. Validation of integrated burnup code system SWAT2 by the analyses of isotopic composition of spent nuclear fuel

    International Nuclear Information System (INIS)

    Suyama, K.; Mochizuki, H.; Okuno, H.; Miyoshi, Y.

    2004-01-01

    This paper provides validation results of SWAT2, the revised version of SWAT, which is a code system combining point burnup code ORIGEN2 and continuous energy Monte Carlo code MVP, by the analysis of post irradiation examinations (PIEs). Some isotopes show differences of calculation results between SWAT and SWAT2. However, generally, the differences are smaller than the error of PIE analysis that was reported in previous SWAT validation activity, and improved results are obtained for several important fission product nuclides. This study also includes comparison between an assembly and a single pin cell geometry models. (authors)

  1. SWATMOD-PREP: Graphical user interface for preparing coupled SWAT-modflow simulations

    Science.gov (United States)

    This paper presents SWATMOD-Prep, a graphical user interface that couples a SWAT watershed model with a MODFLOW groundwater flow model. The interface is based on a recently published SWAT-MODFLOW code that couples the models via mapping schemes. The spatial layout of SWATMOD-Prep guides the user t...

  2. A continental-scale hydrology and water quality model for Europe: Calibration and uncertainty of a high-resolution large-scale SWAT model

    Science.gov (United States)

    Abbaspour, K. C.; Rouholahnejad, E.; Vaghefi, S.; Srinivasan, R.; Yang, H.; Kløve, B.

    2015-05-01

    A combination of driving forces are increasing pressure on local, national, and regional water supplies needed for irrigation, energy production, industrial uses, domestic purposes, and the environment. In many parts of Europe groundwater quantity, and in particular quality, have come under sever degradation and water levels have decreased resulting in negative environmental impacts. Rapid improvements in the economy of the eastern European block of countries and uncertainties with regard to freshwater availability create challenges for water managers. At the same time, climate change adds a new level of uncertainty with regard to freshwater supplies. In this research we build and calibrate an integrated hydrological model of Europe using the Soil and Water Assessment Tool (SWAT) program. Different components of water resources are simulated and crop yield and water quality are considered at the Hydrological Response Unit (HRU) level. The water resources are quantified at subbasin level with monthly time intervals. Leaching of nitrate into groundwater is also simulated at a finer spatial level (HRU). The use of large-scale, high-resolution water resources models enables consistent and comprehensive examination of integrated system behavior through physically-based, data-driven simulation. In this article we discuss issues with data availability, calibration of large-scale distributed models, and outline procedures for model calibration and uncertainty analysis. The calibrated model and results provide information support to the European Water Framework Directive and lay the basis for further assessment of the impact of climate change on water availability and quality. The approach and methods developed are general and can be applied to any large region around the world.

  3. OpenMP-accelerated SWAT simulation using Intel C and FORTRAN compilers: Development and benchmark

    Science.gov (United States)

    Ki, Seo Jin; Sugimura, Tak; Kim, Albert S.

    2015-02-01

    We developed a practical method to accelerate execution of Soil and Water Assessment Tool (SWAT) using open (free) computational resources. The SWAT source code (rev 622) was recompiled using a non-commercial Intel FORTRAN compiler in Ubuntu 12.04 LTS Linux platform, and newly named iOMP-SWAT in this study. GNU utilities of make, gprof, and diff were used to develop the iOMP-SWAT package, profile memory usage, and check identicalness of parallel and serial simulations. Among 302 SWAT subroutines, the slowest routines were identified using GNU gprof, and later modified using Open Multiple Processing (OpenMP) library in an 8-core shared memory system. In addition, a C wrapping function was used to rapidly set large arrays to zero by cross compiling with the original SWAT FORTRAN package. A universal speedup ratio of 2.3 was achieved using input data sets of a large number of hydrological response units. As we specifically focus on acceleration of a single SWAT run, the use of iOMP-SWAT for parameter calibrations will significantly improve the performance of SWAT optimization.

  4. Comparison of MODIS and SWAT evapotranspiration over a complex terrain at different spatial scales

    Directory of Open Access Journals (Sweden)

    O. O. Abiodun

    2018-05-01

    Full Text Available In most hydrological systems, evapotranspiration (ET and precipitation are the largest components of the water balance, which are difficult to estimate, particularly over complex terrain. In recent decades, the advent of remotely sensed data based ET algorithms and distributed hydrological models has provided improved spatially upscaled ET estimates. However, information on the performance of these methods at various spatial scales is limited. This study compares the ET from the MODIS remotely sensed ET dataset (MOD16 with the ET estimates from a SWAT hydrological model on graduated spatial scales for the complex terrain of the Sixth Creek Catchment of the Western Mount Lofty Ranges, South Australia. ET from both models was further compared with the coarser-resolution AWRA-L model at catchment scale. The SWAT model analyses are performed on daily timescales with a 6-year calibration period (2000–2005 and 7-year validation period (2007–2013. Differences in ET estimation between the SWAT and MOD16 methods of up to 31, 19, 15, 11 and 9 % were observed at respectively 1, 4, 9, 16 and 25 km2 spatial resolutions. Based on the results of the study, a spatial scale of confidence of 4 km2 for catchment-scale evapotranspiration is suggested in complex terrain. Land cover differences, HRU parameterisation in AWRA-L and catchment-scale averaging of input climate data in the SWAT semi-distributed model were identified as the principal sources of weaker correlations at higher spatial resolution.

  5. Application of the Soil and Water Assessment Tool (SWAT Model on a small tropical island (Great River Watershed, Jamaica as a tool in Integrated Watershed and Coastal Zone Management

    Directory of Open Access Journals (Sweden)

    Orville P. Grey

    2014-09-01

    Full Text Available The Great River Watershed, located in north-west Jamaica, is critical for development, particularly for housing, tourism, agriculture, and mining. It is a source of sediment and nutrient loading to the coastal environment including the Montego Bay Marine Park. We produced a modeling framework using the Soil and Water Assessment Tool (SWAT and GIS. The calculated model performance statistics for high flow discharge yielded a Nash-Sutcliffe Efficiency (NSE value of 0.68 and a R² value of 0.70 suggesting good measured and simulated (calibrated discharge correlation. Calibration and validation results for streamflow were similar to the observed streamflows. For the dry season the simulated urban landuse scenario predicted an increase in surface runoff in excess of 150%. During the wet season it is predicted to range from 98 to 234% presenting a significant risk of flooding, erosion and other environmental issues. The model should be used for the remaining 25 watersheds in Jamaica and elsewhere in the Caribbean. The models suggests that projected landuse changes will have serious impacts on available water (streamflow, stream health, potable water treatment, flooding and sensitive coastal ecosystems.

  6. Application Of Hydrological Models In Poorly Gauged Watersheds A Review Of The Usage Of The Soil And Water Assessment Tool SWAT In Kenya

    Directory of Open Access Journals (Sweden)

    Wambugu Mwangi

    2017-08-01

    Full Text Available In water-scarce developing countries river basins are some of the most valued natural resources but many are poorly gauged and have incomplete hydrological and climate records. In the recent years tropical rivers are increasingly becoming erratic with many hydrologists attributing this variability to combined effects of landscape-specific anthropogenic activities and climate change. Uncertainties about the impacts of climate change compound the challenges attributed to poor and often inconsistent river monitoring data. Under data-scarce conditions and with the increasing land use intensification and urbanization modelling approaches become a useful tool in planning and management of water resources. In this paper we review the application and usability of the Soil and Water Assessment Tool SWAT model in conventional planning practice in the management of water resources is poorly-gauged tropical watersheds of Kenya. We assess the technical implications of the model in Intergrated Water Resources management IWRM and its applicability as a planning and management tool for water resources in the era of climate change.

  7. Calibration of a Field-Scale Soil and Water Assessment Tool (SWAT Model with Field Placement of Best Management Practices in Alger Creek, Michigan

    Directory of Open Access Journals (Sweden)

    Katherine R. Merriman

    2018-03-01

    Full Text Available Subwatersheds within the Great Lakes “Priority Watersheds” were targeted by the Great Lakes Restoration Initiative (GLRI to determine the effectiveness of the various best management practices (BMPs from the U.S. Department of Agriculture-Natural Resources Conservation Service National Conservation Planning (NCP Database. A Soil and Water Assessment Tool (SWAT model is created for Alger Creek, a 50 km2 tributary watershed to the Saginaw River in Michigan. Monthly calibration yielded very good Nash–Sutcliffe efficiency (NSE ratings for flow, sediment, total phosphorus (TP, dissolved reactive phosphorus (DRP, and total nitrogen (TN (0.90, 0.79, 0.87, 0.88, and 0.77, respectively, and satisfactory NSE rating for nitrate (0.51. Two-year validation results in at least satisfactory NSE ratings for flow, sediment, TP, DRP, and TN (0.83, 0.54, 0.73, 0.53, and 0.60, respectively, and unsatisfactory NSE rating for nitrate (0.28. The model estimates the effect of BMPs at the field and watershed scales. At the field-scale, the most effective single practice at reducing sediment, TP, and DRP is no-tillage followed by cover crops (CC; CC are the most effective single practice at reducing nitrate. The most effective BMP combinations include filter strips, which can have a sizable effect on reducing sediment and phosphorus loads. At the watershed scale, model results indicate current NCP BMPs result in minimal sediment and nutrient reductions (<10%.

  8. Calibration of a field-scale Soil and Water Assessment Tool (SWAT) model with field placement of best management practices in Alger Creek, Michigan

    Science.gov (United States)

    Merriman-Hoehne, Katherine R.; Russell, Amy M.; Rachol, Cynthia M.; Daggupati, Prasad; Srinivasan, Raghavan; Hayhurst, Brett A.; Stuntebeck, Todd D.

    2018-01-01

    Subwatersheds within the Great Lakes “Priority Watersheds” were targeted by the Great Lakes Restoration Initiative (GLRI) to determine the effectiveness of the various best management practices (BMPs) from the U.S. Department of Agriculture-Natural Resources Conservation Service National Conservation Planning (NCP) Database. A Soil and Water Assessment Tool (SWAT) model is created for Alger Creek, a 50 km2 tributary watershed to the Saginaw River in Michigan. Monthly calibration yielded very good Nash–Sutcliffe efficiency (NSE) ratings for flow, sediment, total phosphorus (TP), dissolved reactive phosphorus (DRP), and total nitrogen (TN) (0.90, 0.79, 0.87, 0.88, and 0.77, respectively), and satisfactory NSE rating for nitrate (0.51). Two-year validation results in at least satisfactory NSE ratings for flow, sediment, TP, DRP, and TN (0.83, 0.54, 0.73, 0.53, and 0.60, respectively), and unsatisfactory NSE rating for nitrate (0.28). The model estimates the effect of BMPs at the field and watershed scales. At the field-scale, the most effective single practice at reducing sediment, TP, and DRP is no-tillage followed by cover crops (CC); CC are the most effective single practice at reducing nitrate. The most effective BMP combinations include filter strips, which can have a sizable effect on reducing sediment and phosphorus loads. At the watershed scale, model results indicate current NCP BMPs result in minimal sediment and nutrient reductions (<10%).

  9. Assessing the cumulative impacts of geographically isolated wetlands on watershed hydrology using the SWAT model coupled with improved wetland modules.

    Science.gov (United States)

    Lee, S; Yeo, I-Y; Lang, M W; Sadeghi, A M; McCarty, G W; Moglen, G E; Evenson, G R

    2018-06-07

    Despite recognizing the importance of wetlands in the Coastal Plain of the Chesapeake Bay Watershed (CBW) in terms of ecosystem services, our understanding of wetland functions has mostly been limited to individual wetlands and overall catchment-scale wetland functions have rarely been investigated. This study is aimed at assessing the cumulative impacts of wetlands on watershed hydrology for an agricultural watershed within the Coastal Plain of the CBW using the Soil and Water Assessment Tool (SWAT). We employed two improved wetland modules for enhanced representation of physical processes and spatial distribution of riparian wetlands (RWs) and geographically isolated wetlands (GIWs). This study focused on GIWs as their hydrological impacts on watershed hydrology are poorly understood and GIWs are poorly protected. Multiple wetland scenarios were prepared by removing all or portions of the baseline GIW condition indicated by the U.S. Fish and Wildlife Service National Wetlands Inventory geospatial dataset. We further compared the impacts of GIWs and RWs on downstream flow (i.e., streamflow at the watershed outlet). Our simulation results showed that GIWs strongly influenced downstream flow by altering water transport mechanisms in upstream areas. Loss of all GIWs reduced both water routed to GIWs and water infiltrated into the soil through the bottom of GIWs, leading to an increase in surface runoff of 9% and a decrease in groundwater flow of 7% in upstream areas. These changes resulted in increased variability of downstream flow in response to extreme flow conditions. GIW loss also induced an increase in month to month variability of downstream flow and a decrease in the baseflow contribution to streamflow. Loss of all GIWs was shown to cause a greater fluctuation of downstream flow than loss of all RWs for this study site, due to a greater total water storage capacity of GIWs. Our findings indicate that GIWs play a significant role in controlling hydrological

  10. Assessment of TRMM Products and Their Influence on Hydrologic Models within the Middle East and North Africa (MENA) Region Using the Soil and Water Assessment Tool (SWAT)

    Science.gov (United States)

    Milewski, A.; El Kadiri, R.; Durham, M. C.

    2013-12-01

    Satellite remote sensing datasets have been increasingly employed as an ancillary source of essential hydrologic measurements used for the modeling of hydrologic fluxes. Precipitation is one of the most important meteorological forcing parameter in hydrological investigations and land surface modeling, yet it is largely unknown or misused in water budgets and hydrologic models. The Tropical Rainfall Measurement Mission (TRMM) satellite products are widely being used by the scientific community due to the general spatial and temporal paucity of precipitation data in many parts of world and particularly in the Middle East and North Africa (MENA) region. This research utilized a two-fold approach towards understanding the accuracy of satellite-based rainfall and its application in hydrologic models First, we evaluated the uncertainty, accuracy, and precision of various rainfall satellite products (i.e. TRMM 3B42 V6, TRMM 3B42 V7, TRMM 3B42 V7a and TRMM 3B42 RT) in comparison to in situ gauge data from more than 150 rain gauges in Morocco and across the MENA region. Our analyses extend over many parts of the MENA region in order to assess the effect that different climatic regimes and topographic characteristics have on each TRMM product. Secondly, we analyzed and compared the hydrologic fluxes produced from different modeling inputs for several watersheds within the MENA region. SWAT (Soil and Water Assessment Tool) hydrologic models have been developed for the Oum Er Rbia (Morocco), Asyuti (Egypt), and the Sakarya (Turkey) watersheds. SWAT models produced for each watershed include, one model for each of the four satellite TRMM product (STBM-V6, STBM-V7, STBM-V7a, and STBM-RT) and one model for rain gauge based model (RGBM). Findings indicate the best correlation between field-based and satellite-based rainfall measurements is the TRMM V7a (Pearson coefficient: 0.875) product, followed by TRMM V7 (Pearson coefficient: 0.84), then TRMM V6 (Pearson coefficient: 0

  11. Adequacy of TRMM satellite rainfall data in driving the SWAT modeling of Tiaoxi catchment (Taihu lake basin, China)

    Science.gov (United States)

    Li, Dan; Christakos, George; Ding, Xinxin; Wu, Jiaping

    2018-01-01

    Spatial rainfall data is an essential input to Distributed Hydrological Models (DHM), and a significant contributor to hydrological model uncertainty. Model uncertainty is higher when rain gauges are sparse, as is often the case in practice. Currently, satellite-based precipitation products increasingly provide an alternative means to ground-based rainfall estimates, in which case a rigorous product assessment is required before implementation. Accordingly, the twofold objective of this work paper was the real-world assessment of both (a) the Tropical Rainfall Measuring Mission (TRMM) rainfall product using gauge data, and (b) the TRMM product's role in forcing data for hydrologic simulations in the area of the Tiaoxi catchment (Taihu lake basin, China). The TRMM rainfall products used in this study are the Version-7 real-time 3B42RT and the post-real-time 3B42. It was found that the TRMM rainfall data showed a superior performance at the monthly and annual scales, fitting well with surface observation-based frequency rainfall distributions. The Nash-Sutcliffe Coefficient of Efficiency (NSCE) and the relative bias ratio (BIAS) were used to evaluate hydrologic model performance. The satisfactory performance of the monthly runoff simulations in the Tiaoxi study supports the view that the implementation of real-time 3B42RT allows considerable room for improvement. At the same time, post-real-time 3B42 can be a valuable tool of hydrologic modeling, water balance analysis, and basin water resource management, especially in developing countries or at remote locations in which rainfall gauges are scarce.

  12. Fecal bacteria source characterization and sensitivity analysis of SWAT 2005

    Science.gov (United States)

    The Soil and Water Assessment Tool (SWAT) version 2005 includes a microbial sub-model to simulate fecal bacteria transport at the watershed scale. The objectives of this study were to demonstrate methods to characterize fecal coliform bacteria (FCB) source loads and to assess the model sensitivity t...

  13. Analysing the Effects of Forest Cover and Irrigation Farm Dams on Streamflows of Water-Scarce Catchments in South Australia through the SWAT Model

    Directory of Open Access Journals (Sweden)

    Hong Hanh Nguyen

    2017-01-01

    Full Text Available To assist water resource managers with future land use planning efforts, the eco-hydrological model Soil and Water Assessment Tool (SWAT was applied to three catchments in South Australia that experience extreme low flow conditions. Particular land uses and management issues of interest included forest covers, known to affect water yields, and farm dams, known to intercept and change the hydrological dynamics in a catchment. The study achieved a satisfactory daily calibration when irrigation farm dams were incorporated in the model. For the catchment dominated by extreme low flows, a better daily simulation across a range of qualitative and quantitative metrics was gained using the base-flow static threshold optimization technique. Scenario analysis on effects of forest cover indicated an increase of surface flow and a reduction of base-flow when native eucalyptus lands were replaced by pastures and vice versa. A decreasing trend was observed for the overall water yield of catchments with more forest plantation due to the higher evapotranspiration (ET rate and the decline in surface flow. With regards to effects of irrigation farm dams, assessment on a daily time step suggested that a significant volume of water is stored in these systems with the water loss rate highest in June and July. On an annual basis, the model indicated that approximately 13.1% to 22.0% of water has been captured by farm dams for irrigation. However, the scenario analysis revealed that the purposes of use of farm dams rather than their volumetric capacities in the catchment determined the magnitude of effects on streamflows. Water extracted from farm dams for irrigation of orchards and vineyards are more likely to diminish streamflows than other land uses. Outputs from this study suggest that the water use restrictions from farm dams during recent drought periods were an effective tool to minimize impacts on streamflows.

  14. Příprava podkladů pro modelování odtoku a odnosu látek v prostředí SWAT

    OpenAIRE

    HOMOLKA, Jan

    2012-01-01

    This bachelor thesis is dealing with preparation bases for modelation draining and carrying materials in SWAT model. Thesis includes literature search about basis of SWAT model, SWAT development, preferences and imprefections of this model. It?s also going over various modelations and general division. Further describes necessary input data, their types and requirements without which would be impossible to complete this task. I?ve chosen Jenín stream basin located near village Jenín which is ...

  15. Application of SWAT to assess the effects of land use change in the Murchison Bay catchment in Uganda

    Science.gov (United States)

    The Soil and Water Assessment Tool (SWAT) is a versatile model presently used worldwide to evaluate water quality and hydrological concerns under varying land use and environmental conditions. In this study, SWAT was used to simulate streamflow and to estimate sediment yield and nutrients loss from ...

  16. Improving the spatial representation of soil properties and hydrology using topographically derived initialization processes in the SWAT model

    Science.gov (United States)

    Topography exerts critical controls on many hydrologic, geomorphologic, and environmental biophysical processes. Unfortunately many watershed modeling systems use topography only to define basin boundaries and stream channels and do not explicitly account for the topographic controls on processes su...

  17. Cost-effectiveness and cost-benefit analysis of BMPs in controlling agricultural nonpoint source pollution in China based on the SWAT model.

    Science.gov (United States)

    Liu, Ruimin; Zhang, Peipei; Wang, Xiujuan; Wang, Jiawei; Yu, Wenwen; Shen, Zhenyao

    2014-12-01

    Best management practices (BMPs) have been widely used in managing agricultural nonpoint source pollution (ANSP) at the watershed level. Most BMPs are related to land use, tillage management, and fertilizer levels. In total, seven BMP scenarios (Reforest1, Reforest2, No Tillage, Contour tillage, and fertilizer level 1-4) that are related to these three factors were estimated in this study. The objectives were to investigate the effectiveness and cost-benefit of these BMPs on ANSP reduction in a large tributary of the Three Gorges Reservoir (TGR) in China, which are based on the simulation results of the Soil and Water Assessment Tool (SWAT) model. The results indicated that reforestation was the most economically efficient of all BMPs, and its net benefits were up to CNY 4.36×10(7) years(-1) (about USD 7.08×10(6) years(-1)). Regarding tillage practices, no tillage practice was more environmentally friendly than other tillage practices, and contour tillage was more economically efficient. Reducing the local fertilizer level to 0.8-fold less than that of 2010 can yield a satisfactory environmental and economic efficiency. Reforestation and fertilizer management were more effective in reducing total phosphorus (TP), whereas tillage management was more effective in reducing total nitrogen (TN). When CNY 10,000 (about USD 162) was applied to reforestation, no tillage, contour tillage, and an 0.8-fold reduction in the fertilizer level, then annual TN load can be reduced by 0.08, 0.16, 0.11, and 0.04 t and annual TP load can be reduced by 0.04, 0.02, 0.01 and 0.03 t, respectively. The cost-benefit (CB) ratios of the BMPs were as follows: reforestation (207 %) > contour tillage (129 %) > no tillage (114 %) > fertilizer management (96 and 89 %). The most economical and effective BMPs can be designated as follows: BMP1 (returning arable land with slopes greater than 25° to forests and those lands with slopes of 15-25° to orchards), BMP2 (implementing no tillage

  18. Prediction of land use changes based on land change modeler and attribution of changes in the water balance of Ganga basin to land use change using the SWAT model

    Science.gov (United States)

    Anand, J.; Gosain, A. K.; Khosa, R.

    2017-12-01

    Conflicts between increasing irrigated agricultural area, commercial crops, shifting cultivation and ever increasing domestic and industrial demand has already been a cause of tension in the society over water in the Ganga River Basin, India. For the development of sustainable water resource strategies, it is essential to establish interaction between landuse changes and local hydrology through proper assessment. Precisely, seeing how change in each LULC affects hydrologic regimes, or conversely evaluating which LULC shall be appropriate for the local hydrological regime can help decision makers to incorporate in the policy instruments. In this study, we assess hydrologic regimes of the Ganga River basin with landuse change. Catchment hydrologic responses were simulated using Soil and Water Assessment Tool (SWAT). Meteorological data from IMD of 0.25°×0.25° spatial resolution were taken as the climate inputs. Simulated stream flow was compared at different gauge stations distributed across the Gang basin and its tributaries. Urbanization was the topmost contributor to the increase in surface runoff and water yield. While, increased irrigation demands was the dominant contributor to the water consumption and also added to the increased evapotranspiration. In addition scenarios have been generated to study the impact of landuse change on various components of hydrology including groundwater recharge, with different cropping patterns and increased irrigation efficiency to determine various mitigation strategies that can be adopted. This study can be important tool in quantifying the changes in hydrological components in response to changes made in landuse in especially basins undergoing rapid commercialization. This shall provide substantive information to the decision makers required to develop ameliorative strategies. Keywords: Landuse and Landcover change, Hydrologic model, Soil Water Assessment Tool (SWAT), Urbanization, Ganga River, Watershed hydrology.

  19. Attribution of changes in the water balance of a tropical catchment to land use change using the SWAT model

    NARCIS (Netherlands)

    Marhaento, Hero; Booij, Martijn J.; Rientjes, T. H.M.; Hoekstra, Arjen Y.

    2017-01-01

    Changes in the water balance of the Samin catchment (277.9 km2) on Java, Indonesia, can be attributed to land use change using the Soil Water Assessment Tool model. A baseline-altered method was used in which the simulation period 1990–2013 was divided into 4 equal periods to represent baseline

  20. Revised SWAT. The integrated burnup calculation code system

    Energy Technology Data Exchange (ETDEWEB)

    Suyama, Kenya; Mochizuki, Hiroki [Department of Fuel Cycle Safety Research, Nuclear Safety Research Center, Tokai Research Establishment, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan); Kiyosumi, Takehide [The Japan Research Institute, Ltd., Tokyo (Japan)

    2000-07-01

    SWAT is an integrated burnup code system developed for analysis of post irradiation examination, transmutation of radioactive waste, and burnup credit problem. This report shows an outline and a user's manual of revised SWAT. This revised SWAT includes expansion of functions, increasing supported machines, and correction of several bugs reported from users of previous SWAT. (author)

  1. Revised SWAT. The integrated burnup calculation code system

    International Nuclear Information System (INIS)

    Suyama, Kenya; Mochizuki, Hiroki; Kiyosumi, Takehide

    2000-07-01

    SWAT is an integrated burnup code system developed for analysis of post irradiation examination, transmutation of radioactive waste, and burnup credit problem. This report shows an outline and a user's manual of revised SWAT. This revised SWAT includes expansion of functions, increasing supported machines, and correction of several bugs reported from users of previous SWAT. (author)

  2. Modeling the Effects of Onsite Wastewater Treatment Systems on Nitrate Loads Using SWAT in an Urban Watershed of Metropolitan Atlanta.

    Science.gov (United States)

    Hoghooghi, Nahal; Radcliffe, David E; Habteselassie, Mussie Y; Jeong, Jaehak

    2017-05-01

    Onsite wastewater treatment systems (OWTSs) can be a source of nitrogen (N) pollution in both surface and ground waters. In metropolitan Atlanta, GA, >26% of homes are on OWTSs. In a previous article, we used the Soil Water Assessment Tool to model the effect of OWTSs on stream flow in the Big Haynes Creek Watershed in metropolitan Atlanta. The objective of this study was to estimate the effect of OWTSs, including failing systems, on nitrate as N (NO-N) load in the same watershed. Big Haynes Creek has a drainage area of 44 km with mainly urban land use (67%), and most of the homes use OWTSs. A USGS gauge station where stream flow was measured daily and NO-N concentrations were measured monthly was used as the outlet. The model was simulated for 12 yr. Overall, the model showed satisfactory daily stream flow and NO-N loads with Nash-Sutcliffe coefficients of 0.62 and 0.58 for the calibration period and 0.67 and 0.33 for the validation period at the outlet of the Big Haynes Watershed. Onsite wastewater treatment systems caused an average increase in NO-N load of 23% at the watershed scale and 29% at the outlet of a subbasin with the highest density of OWTSs. Failing OWTSs were estimated to be 1% of the total systems and did not have a large impact on stream flow or NO-N load. The NO-N load was 74% of the total N load in the watershed, indicating the important effect of OWTSs on stream loads in this urban watershed. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  3. Rainfall estimation in SWAT: An alternative method to simulate orographic precipitation

    Science.gov (United States)

    Galván, L.; Olías, M.; Izquierdo, T.; Cerón, J. C.; Fernández de Villarán, R.

    2014-02-01

    The input of water from precipitation is one of the most important aspects of a hydrologic model because it controls the basin's water budget. The model should reproduce the amount and distribution of rainfall in the basin, spatially and temporally. SWAT (Soil and Water Assessment Tool) is one of the most widely used hydrologic models. In this paper the rainfall estimation in SWAT is revised, focusing on the treatment of orographic precipitation. SWAT was applied to the Odiel river basin (SW Spain), with a surface of 2300 km2. Results show that SWAT does not reflect reallisticaly the spatial distribution of rainfall in the basin. In relation to orographic precipitation, SWAT estimates the daily precipitation in elevation bands by adding a constant amount to the recorded precipitation in the rain gauge, which depends on the increase in precipitation with altitude and the difference between the mean elevation of each band and the elevation of the recording gauge. This does not reflect rainfall in the subbasin because the increase in precipitation with altitude actually it is not constant, but depends on the amount of rainfall. An alternative methodology to represent the temporal distribution of orographic precipitation is proposed. After simulation, the deviation of runoff volume using the SWAT elevation bands was appreciably higher than that obtained with the proposed methodology.

  4. Calibration of Spatially Distributed Hydrological Processes and Model Parameters in SWAT Using Remote Sensing Data and an Auto-Calibration Procedure: A Case Study in a Vietnamese River Basin

    Directory of Open Access Journals (Sweden)

    Lan Thanh Ha

    2018-02-01

    Full Text Available In this paper, evapotranspiration (ET and leaf area index (LAI were used to calibrate the SWAT model, whereas remotely sensed precipitation and other climatic parameters were used as forcing data for the 6300 km2 Day Basin, a tributary of the Red River in Vietnam. The efficacy of the Sequential Uncertainty Fitting (SUFI-2 parameter sensitivity and optimization model was tested with area specific remote sensing input parameters for every Hydrological Response Units (HRU, rather than with measurements of river flow representing a large set of HRUs, i.e., a bulk calibration. Simulated monthly ET correlations with remote sensing estimates showed an R2 = 0.71, Nash–Sutcliffe Efficiency NSE = 0.65, and Kling Gupta Efficiency KGE = 0.80 while monthly LAI showed correlations of R2 = 0.59, NSE = 0.57 and KGE = 0.83 over a five-year validation period. Accumulated modelled ET over the 5-year calibration period amounted to 5713 mm compared to 6015 mm of remotely sensed ET, yielding a difference of 302 mm (5.3%. The monthly flow at two flow measurement stations were adequately estimated (R2 = 0.78 and 0.55, NSE = 0.71 and 0.63, KGE = 0.59 and 0.75 for Phu Ly and Ninh Binh, respectively. This outcome demonstrates the capability of SWAT model to obtain spatial and accurate simulation of eco-hydrological processes, also when rivers are ungauged and the water withdrawal system is complex.

  5. SWAT4.0 - The integrated burnup code system driving continuous energy Monte Carlo codes MVP, MCNP and deterministic calculation code SRAC

    International Nuclear Information System (INIS)

    Kashima, Takao; Suyama, Kenya; Takada, Tomoyuki

    2015-03-01

    There have been two versions of SWAT depending on details of its development history: the revised SWAT that uses the deterministic calculation code SRAC as a neutron transportation solver, and the SWAT3.1 that uses the continuous energy Monte Carlo code MVP or MCNP5 for the same purpose. It takes several hours, however, to execute one calculation by the continuous energy Monte Carlo code even on the super computer of the Japan Atomic Energy Agency. Moreover, two-dimensional burnup calculation is not practical using the revised SWAT because it has problems on production of effective cross section data and applying them to arbitrary fuel geometry when a calculation model has multiple burnup zones. Therefore, SWAT4.0 has been developed by adding, to SWAT3.1, a function to utilize the deterministic code SARC2006, which has shorter calculation time, as an outer module of neutron transportation solver for burnup calculation. SWAT4.0 has been enabled to execute two-dimensional burnup calculation by providing an input data template of SRAC2006 to SWAT4.0 input data, and updating atomic number densities of burnup zones in each burnup step. This report describes outline, input data instruction, and examples of calculations of SWAT4.0. (author)

  6. Impact assessment of salt iodization on the prevalence of goiter in district Swat

    International Nuclear Information System (INIS)

    Akhtar, J.; Zahoor-Ullah; Paracha, P.I.; Lutfullah, G.

    2004-01-01

    Background: To eliminate Iodine Deficiency Disorders, (IDD) universal salt iodization is the widely practiced intervention. District Swat (a hilly area of NWFP, highly endemic for IDDs is selected as a first model district of the province for salt iodization program. Objectives: To find out the proportion of the families using iodized salt, iodine contents of the salts used by the families, urinary iodine levels in school children and the effect on goiter prevalence in Swat selected as a model district in 1998. Subject and Methods: The study was conducted in 960 children of both sexes, age 8-10 years in primary schools of district Swat in the year 2000. A replicate model used for base line study in 1998 was adopted. The students were clinically examined for goiter using palpation method. 960 edible salt samples for its iodine content and 240 urine samples for iodine level were analysed. Results: The overall goiter prevalence was found to be 52 and 45% in boys and girls respectively. 23% salt samples were found un-iodized, while in 25.6% the iodine content was less than 7ppm. The results revealed 18% decrease in total goiter rate and 35% increase in the use of iodized salt from the base line survey conducted in 1998, in school children of district Swat. Conclusions: The study revealed that since the area of Swat is still highly endemic for Iodine Deficiency Disorders, sustained efforts are required to ensure 100% salt iodization. (author)

  7. Guidelines for using sensitivity analysis and auto-calibration tools for multi-gage or multi-step calibration in SWAT

    Science.gov (United States)

    Autocalibration of a water quality model such as SWAT (Soil and Water Assessment Tool) can be a powerful, labor-saving tool. When multi-gage or multi-pollutant calibration is desired, autocalibration is essential because the time involved in manual calibration becomes prohibitive. The ArcSWAT Interf...

  8. Hydrological Responses of Climate and Land Use/Cover Changes in Tao'er River Basin Based on the SWAT Model

    Science.gov (United States)

    Liu, J.; Kou, L.

    2015-12-01

    Abstract: The changes of both climate and land use/cover have some impact on the water resources. For Tao'er River Basin, these changes have a direct impact on the land use pattern adjustment, wetland protection, connection project between rivers and reservoirs, local social and economic development, etc. Therefore, studying the impact of climate and land use/cover changes is of great practical significance. The Soil and Water Assessment Tool (SWAT) is used as the research method. With historical actual measured runoff data and the yearly land use classification caught by satellite remote sensing maps, analyze the impact of climate change on the runoff of Tao'er River. And according to the land use/cover classification of 1990, 2000 and 2010, analyze the land use/cover change in the recent 30 years, the impact of the land use/cover change on the river runoff and the contribution coefficient of farmland, woodland, grassland and other major land-use types to the runoff. These studies can provide some references to the rational allocation of water resource and adjustment of land use structure in this area.

  9. Developing a Resource for Implementing ArcSWAT Using Global Datasets

    Science.gov (United States)

    Taggart, M.; Caraballo Álvarez, I. O.; Mueller, C.; Palacios, S. L.; Schmidt, C.; Milesi, C.; Palmer-Moloney, L. J.

    2015-12-01

    This project developed a comprehensive user manual outlining methods for adapting and implementing global datasets for use within ArcSWAT for international and worldwide applications. The Soil and Water Assessment Tool (SWAT) is a hydrologic model that looks at a number of hydrologic variables including runoff and the chemical makeup of water at a given location on the Earth's surface using Digital Elevation Models (DEM), land cover, soil, and weather data. However, the application of ArcSWAT for projects outside of the United States is challenging as there is no standard framework for inputting global datasets into ArcSWAT. This project aims to remove this obstacle by outlining methods for adapting and implementing these global datasets via the user manual. The manual takes the user through the processes of data conditioning while providing solutions and suggestions for common errors. The efficacy of the manual was explored using examples from watersheds located in Puerto Rico, Mexico and Western Africa. Each run explored the various options for setting up a ArcSWAT project as well as a range of satellite data products and soil databases. Future work will incorporate in-situ data for validation and calibration of the model and outline additional resources to assist future users in efficiently implementing the model for worldwide applications. The capacity to manage and monitor freshwater availability is of critical importance in both developed and developing countries. As populations grow and climate changes, both the quality and quantity of freshwater are affected resulting in negative impacts on the health of the surrounding population. The use of hydrologic models such as ArcSWAT can help stakeholders and decision makers understand the future impacts of these changes enabling informed and substantiated decisions.

  10. 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.

  11. Hydrologic Response Unit Routing in SWAT to Simulate Effects of Vegetated Filter Strip for South-Korean Conditions Based on VFSMOD

    Directory of Open Access Journals (Sweden)

    Kyoung Jae Lim

    2011-08-01

    Full Text Available The Soil and Water Assessment Tool (SWAT model has been used worldwide for many hydrologic and Non-Point Source (NPS Pollution analyses on a watershed scale. However, it has many limitations in simulating the Vegetative Filter Strip (VFS because it considers only ‘filter strip width’ when the model estimates sediment trapping efficiency and does not consider the routing of sediment with overland flow which is expected to maximize the sediment trapping efficiency from upper agricultural subwatersheds to lower spatially-explicit filter strips. Therefore, the SWAT overland flow option between landuse-subwatersheds with sediment routing capability was enhanced by modifying the SWAT watershed configuration and SWAT engine based on the numerical model VFSMOD applied to South-Korean conditions. The enhanced SWAT can simulate the VFS sediment trapping efficiency for South-Korean conditions in a manner similar to the desktop VFSMOD-w system. Due to this enhancement, SWAT is applicable to simulate the effects of overland flow from upper subwatersheds to reflect increased runoff volume at the lower subwatershed, which occurs in the field if no diversion channel is installed. In this study, the enhanced SWAT model was applied to small watersheds located at Jaun-ri in South-Korea to simulate a diversion channel and spatially-explicit VFS. Sediment can be reduced by 31%, 65%, and 68%, with a diversion channel, the VFS, and the VFS with diversion channel, respectively. The enhanced SWAT should be used in estimating site-specific effects on sediment reduction with diversion channels and VFS, instead of the currently available SWAT, which does not simulate sediment routing in overland flow and does not consider other sensitive factors affecting sediment reduction with VFS.

  12. Modeling discharge and water quality in a temporary river basin using SWAT model: A case-study on the Ardila river

    OpenAIRE

    Durão, Anabela; Serafim, António; Brito, David; Morais, Manuela

    2012-01-01

    Temporary rivers have a hydrologic variability, which are characterized by long drought periods and short floods events, that influences water quality. Analysis of river flow generated in the Ardila river basin (temporary regime) using precipitation data (from 1931 to 2003) from a weather station, located within the basin, at the Portuguese side (which represents only 22% of the study area) showed a discrepancy between the modeled and observed runoff since 1981. It was also revealed a satisfa...

  13. Sodium-water reaction test facility (SWAT-3)

    International Nuclear Information System (INIS)

    Shimazu, Hisashi; Ukechi, Kazutoshi; Sasakura, Kazutake; Kusunoki, Junichi

    1976-01-01

    In the development of the liquid metal cooled fast breeder reactor (LMFBR), the steam generator (SG) is considered one of the most important components. The Power Reactor and Nuclear Fuel Development Corporation (PNC) is now promoting the research and development of the SG system used with the prototype fast breeder reactor ''Monju''. In this research, the phenomena of the sodium-water reaction in the SG are the key which must be investigated for the solution of problems. The test facility (SWAT-3) simulating Monju's SG on the scale of 1/2.5 was designed, fabricated and installed by IHI at Oarai Engineering Center of PNC, its pre-operation being accomplished in February 1975. The purpose of SWAT-3 is summarized as follows: (1) To perform an overall test on the safety of Monju's SG and intermediate heat transport system under the design condition against sodium-water reaction accidents. (2) To investigate the damage of the SG structure caused by the sodium-water reaction, and the possibility of repair and recovery operations. The first test was accomplished successfully on June 9, 1975. As a result of the test, the fundamental function of this test facility was proven to be satisfactory as expected. (auth.)

  14. Characterizing snowmelt regime of the river swat - a case study

    International Nuclear Information System (INIS)

    Malik, M.A.

    2015-01-01

    Snowmelt generates 70 to 80% of runoff of Indus River and its tributaries. Forecasting snowmelt generated flow is important for water management, reservoir operation and channel diversion. River Swat being not direct contributor to the existing reservoirs remained out of focus for characterizing its snowmelt regime. Thirty years (1971-2000) data of upper Swat catchment above Kalam gauging station was acquired from WAPDA. Normal monthly values over the period and average monthly values of each year were determined for stream flow, precipitation and temperature together with average monthly values of weighted and maximum temperature. Snowmelt regime was ascertained from plot of normal values of flow, precipitation and temperature. Using temperature index approach, average monthly flow over the snowmelt months (April, May and June) in terms of mm depth over the catchment was regressed on all the temperature indices using exponential, power and third degree polynomial functions. Tmax was found the best index for snowmelt with R2 as 0.902 for the third degree polynomial function. Runoff coefficient (ROC) for the total precipitation was conceptualized and through iteration was found as T max 100. The optimized value of ROC was used to segregate rain induced and snowmelt induced runoff. The segregated snowmelt induced runoff was again regressed on Tmax using the same function which slightly improved R2 to 0.916. The model was tested for four years of data and forecasted flow was found reasonable in the context of simplicity of the approach. (author)

  15. The SWAT approach for pipeline watercourse crossings

    Energy Technology Data Exchange (ETDEWEB)

    Jasper, Steve [WorleyParsons Calgary, Pipeline Systems Business Unit, Calgary, AB (Canada)], email: steve.jasper@worleyparsons.com; Harris, Jason D. [Triton Environmental Consultants Ltd., Terrace, British Columbia (Canada)], email: jharris@triton-env.com; Doering, Raymond [Enbridge Northern Gateway Pipelines, Calgary, AB (Canada)], email: raymond.doering@enbridge.com

    2010-07-01

    In a pipeline project, watercourse crossings are an important environmental and technical challenge. In identifying the best crossing location and method, many factors must be taken into account such as fish habitat, access, geotechnical and hydrological issues. The aim of this paper is to present a program used in a major pipeline project to assess crossings of sensitive watercourses. This program was implemented in the Enbridge Northern Gateway project which extends from Bruderheim, Alberta, to Kitimat, British Columbia, crossing over 750 watercourses. A sensitive watercourse assessment (SWAT) team composed of a fisheries biologist, a pipeline watercourse construction specialist and other personnel carried out assessments on the 200 sensitive watercourses identified. This program led to recommendations to shift the crossing location at 40% of the sensitive sites. This project showed that setting up a SWAT team be helpful in choosing the best location, method and construction timing for a crossing.

  16. Estimating shallow groundwater recharge in the headwaters of the Liverpool Plains using SWAT

    OpenAIRE

    Sun, H.; Cornish, P.S.

    2005-01-01

    Metadata only record A physically based catchment model (SWAT) was used for recharge estimation in the headwaters of the Liverpool Plains in NSW, Australia. The study used water balance modelling at the catchment scale to derive parameters for long-term recharge estimation. The derived parameters were further assessed at a subcatchment scale. Modelling results suggest that recharge occurs only in wet years, and is dominated by a few significant years or periods. The results were matched by...

  17. Soil Water and Temperature System (SWATS) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Cook, David R. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-04-01

    The soil water and temperature system (SWATS) provides vertical profiles of soil temperature, soil-water potential, and soil moisture as a function of depth below the ground surface at hourly intervals. The temperature profiles are measured directly by in situ sensors at the Central Facility and many of the extended facilities of the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Southern Great Plains (SGP) site. The soil-water potential and soil moisture profiles are derived from measurements of soil temperature rise in response to small inputs of heat. Atmospheric scientists use the data in climate models to determine boundary conditions and to estimate the surface energy flux. The data are also useful to hydrologists, soil scientists, and agricultural scientists for determining the state of the soil.

  18. Development of a station based climate database for SWAT and APEX assessments in the U.S.

    Science.gov (United States)

    Water quality simulation models such as the Soil and Water Assessment Tool (SWAT) and Agricultural Policy EXtender (APEX) are widely used in the U.S. These models require large amounts of spatial and tabular data to simulate the natural world. Accurate and seamless daily climatic data are critical...

  19. Geomorphological hazards in Swat valley, Pakistan

    International Nuclear Information System (INIS)

    Usman, A.

    1999-01-01

    This study attempts to describe, interpret and analyze, in depth, the varied geomorphological hazards and their impacts prevailing in the swat valley locate in the northern hilly and mountainous regions of Pakistan. The hills and mountains re zones of high geomorphological activity with rapid rates of weathering, active tectonic activities, abundant precipitation, rapid runoff and heavy sediment transport. Due to the varied topography, lithology, steep slope, erodible soil, heavy winter snowfall and intensive rainfall in the spring and summer seasons, several kinds of geomorphological hazards, such as geomorphic gravitational hazards, Fluvial hazards, Glacial hazards, Geo tectonic hazards, are occurring frequently in swat valley. Amongst them, geomorphic gravitational hazards, such as rock fall rock slide, debris slide mud flow avalanches, are major hazards in mountains and hills while fluvial hazards and sedimentation are mainly confined to the alluvial plain and lowlands of the valley. The Getechtonic hazards, on the other hand, have wide spread distribution in the valley the magnitude and occurrence of each king of hazard is thus, varied according to intensity of process and physical geographic environment. This paper discusses the type distribution and damage due to the various geomorphological hazards and their reduction treatments. The study would to be of particular importance and interest to both natural and social scientists, as well as planner, environmentalists and decision-makers for successful developmental interventions in the region. (author)

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

    Science.gov (United States)

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

    2013-04-01

    The ArcSWAT (Soil and Water Assessment Tool) model was adopted for Non-point source (NPS) nitrogen pollution modeling and nitrogen source apportionment for the Changle River watershed, a typical agricultural watershed in Southeast China. Water quality and hydrological parameters were monitored, and the watershed natural conditions (including soil, climate, land use, etc) and pollution sources information were also investigated and collected for SWAT database. The ArcSWAT model was established in the Changle River after the calibrating and validating procedures of the model parameters. Based on the validated SWAT model, the contributions of different nitrogen sources to river TN loading were quantified, and spatial-temporal distributions of NPS nitrogen export to rivers were addressed. The results showed that in the Changle River watershed, Nitrogen fertilizer, nitrogen air deposition and nitrogen soil pool were the prominent pollution sources, which contributed 35%, 32% and 25% to the river TN loading, respectively. There were spatial-temporal variations in the critical sources for NPS TN export to the river. Natural sources, such as soil nitrogen pool and atmospheric nitrogen deposition, should be targeted as the critical sources for river TN pollution during the rainy seasons. Chemical nitrogen fertilizer application should be targeted as the critical sources for river TN pollution during the crop growing season. Chemical nitrogen fertilizer application, soil nitrogen pool and atmospheric nitrogen deposition were the main sources for TN exported from the garden plot, forest and residential land, respectively. However, they were the main sources for TN exported both from the upland and paddy field. These results revealed that NPS pollution controlling rules should focus on the spatio-temporal distribution of NPS pollution sources.

  1. Well performance model

    International Nuclear Information System (INIS)

    Thomas, L.K.; Evans, C.E.; Pierson, R.G.; Scott, S.L.

    1992-01-01

    This paper describes the development and application of a comprehensive oil or gas well performance model. The model contains six distinct sections: stimulation design, tubing and/or casing flow, reservoir and near-wellbore calculations, production forecasting, wellbore heat transmission, and economics. These calculations may be performed separately or in an integrated fashion with data and results shared among the different sections. The model analysis allows evaluation of all aspects of well completion design, including the effects on future production and overall well economics

  2. FEST-C 1.3 & 2.0 for CMAQ Bi-directional NH3, Crop Production, and SWAT Modeling

    Science.gov (United States)

    The Fertilizer Emission Scenario Tool for CMAQ (FEST-C) is developed in a Linux environment, a festc JAVA interface that integrates 14 tools and scenario management options facilitating land use/crop data processing for the Community Multiscale Air Quality (CMAQ) modeling system ...

  3. Analyses of PWR spent fuel composition using SCALE and SWAT code systems to find correction factors for criticality safety applications adopting burnup credit

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hee Sung; Suyama, Kenya; Mochizuki, Hiroki; Okuno, Hiroshi; Nomura, Yasushi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-01-01

    The isotopic composition calculations were performed for 26 spent fuel samples from the Obrigheim PWR reactor and 55 spent fuel samples from 7 PWR reactors using the SAS2H module of the SCALE4.4 code system with 27, 44 and 238 group cross-section libraries and the SWAT code system with the 107 group cross-section library. For the analyses of samples from the Obrigheim PWR reactor, geometrical models were constructed for each of SCALE4.4/SAS2H and SWAT. For the analyses of samples from 7 PWR reactors, the geometrical model already adopted in the SCALE/SAS2H was directly converted to the model of SWAT. The four kinds of calculation results were compared with the measured data. For convenience, the ratio of the measured to calculated values was used as a parameter. When the ratio is less than unity, the calculation overestimates the measurement, and the ratio becomes closer to unity, they have a better agreement. For many important nuclides for burnup credit criticality safety evaluation, the four methods applied in this study showed good coincidence with measurements in general. More precise observations showed, however: (1) Less unity ratios were found for Pu-239 and -241 for selected 16 samples out of the 26 samples from the Obrigheim reactor (10 samples were deselected because their burnups were measured with Cs-137 non-destructive method, less reliable than Nd-148 method the rest 16 samples were measured with); (2) Larger than unity ratios were found for Am-241 and Cm-242 for both the 16 and 55 samples; (3) Larger than unity ratios were found for Sm-149 for the 55 samples; (4) SWAT was generally accompanied by larger ratios than those of SAS2H with some exceptions. Based on the measured-to-calculated ratios for 71 samples of a combined set in which 16 selected samples and 55 samples were included, the correction factors that should be multiplied to the calculated isotopic compositions were generated for a conservative estimate of the neutron multiplication factor

  4. Modelování průtoků a vybraných parametrů jakosti vod na povodí Jenínského potoka modelem SWAT

    OpenAIRE

    HOMOLKA, Jan

    2014-01-01

    The thesis continues with the bachelor thesis which had dealt with preparation bases for simulation draining and carrying materials in SWAT model. Simulation should have been realized within basin of the Jenín stream, which watershed is 4,65 km2 large. SWAT model is primary developed for the larger watersheds where simulated values doesn't attain tolerances. Because of this is thesis focused on the methodic of simulation itself, discussion of the problem when is SWAT model almost useless for ...

  5. Using SWAT and Fuzzy TOPSIS to Assess the Impact of Climate Change in the Headwaters of the Segura River Basin (SE Spain

    Directory of Open Access Journals (Sweden)

    Javier Senent-Aparicio

    2017-02-01

    Full Text Available The Segura River Basin is one of the most water-stressed basins in Mediterranean Europe. If we add to the actual situation that most climate change projections forecast important decreases in water resource availability in the Mediterranean region, the situation will become totally unsustainable. This study assessed the impact of climate change in the headwaters of the Segura River Basin using the Soil and Water Assessment Tool (SWAT with bias-corrected precipitation and temperature data from two Regional Climate Models (RCMs for the medium term (2041–2070 and the long term (2071–2100 under two emission scenarios (RCP4.5 and RCP8.5. Bias correction was performed using the distribution mapping approach. The fuzzy TOPSIS technique was applied to rank a set of nine GCM–RCM combinations, choosing the climate models with a higher relative closeness. The study results show that the SWAT performed satisfactorily for both calibration (NSE = 0.80 and validation (NSE = 0.77 periods. Comparing the long-term and baseline (1971–2000 periods, precipitation showed a negative trend between 6% and 32%, whereas projected annual mean temperatures demonstrated an estimated increase of 1.5–3.3 °C. Water resources were estimated to experience a decrease of 2%–54%. These findings provide local water management authorities with very useful information in the face of climate change.

  6. Modifying the Soil and Water Assessment Tool to simulate cropland carbon flux: Model development and initial evaluation

    International Nuclear Information System (INIS)

    Zhang, Xuesong; Izaurralde, R. César; Arnold, Jeffrey G.; Williams, Jimmy R.; Srinivasan, Raghavan

    2013-01-01

    Climate change is one of the most compelling modern issues and has important implications for almost every aspect of natural and human systems. The Soil and Water Assessment Tool (SWAT) model has been applied worldwide to support sustainable land and water management in a changing climate. However, the inadequacies of the existing carbon algorithm in SWAT limit its application in assessing impacts of human activities on CO 2 emission, one important source of greenhouse gasses (GHGs) that traps heat in the earth system and results in global warming. In this research, we incorporate a revised version of the CENTURY carbon model into SWAT to describe dynamics of soil organic matter (SOM)-residue and simulate land–atmosphere carbon exchange. We test this new SWAT-C model with daily eddy covariance (EC) observations of net ecosystem exchange (NEE) and evapotranspiration (ET) and annual crop yield at six sites across the U.S. Midwest. Results show that SWAT-C simulates well multi-year average NEE and ET across the spatially distributed sites and capture the majority of temporal variation of these two variables at a daily time scale at each site. Our analyses also reveal that performance of SWAT-C is influenced by multiple factors, such as crop management practices (irrigated vs. rainfed), completeness and accuracy of input data, crop species, and initialization of state variables. Overall, the new SWAT-C demonstrates favorable performance for simulating land–atmosphere carbon exchange across agricultural sites with different soils, climate, and management practices. SWAT-C is expected to serve as a useful tool for including carbon flux into consideration in sustainable watershed management under a changing climate. We also note that extensive assessment of SWAT-C with field observations is required for further improving the model and understanding potential uncertainties of applying it across large regions with complex landscapes. - Highlights: • Expanding the SWAT

  7. Modifying the Soil and Water Assessment Tool to simulate cropland carbon flux: Model development and initial evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xuesong; Izaurralde, R. César [Joint Global Change Research Institute, Pacific Northwest National Laboratory and University of Maryland, College Park, MD 20740 (United States); Arnold, Jeffrey G. [Grassland, Soil and Water Research Laboratory USDA-ARS, Temple, TX 76502 (United States); Williams, Jimmy R. [Blackland Research and Extension Center, AgriLIFE Research, 720 E. Blackland Road, Temple, TX 76502 (United States); Srinivasan, Raghavan [Spatial Sciences Laboratory in the Department of Ecosystem Science and Management, Texas A and M University, College Stations, TX 77845 (United States)

    2013-10-01

    Climate change is one of the most compelling modern issues and has important implications for almost every aspect of natural and human systems. The Soil and Water Assessment Tool (SWAT) model has been applied worldwide to support sustainable land and water management in a changing climate. However, the inadequacies of the existing carbon algorithm in SWAT limit its application in assessing impacts of human activities on CO{sub 2} emission, one important source of greenhouse gasses (GHGs) that traps heat in the earth system and results in global warming. In this research, we incorporate a revised version of the CENTURY carbon model into SWAT to describe dynamics of soil organic matter (SOM)-residue and simulate land–atmosphere carbon exchange. We test this new SWAT-C model with daily eddy covariance (EC) observations of net ecosystem exchange (NEE) and evapotranspiration (ET) and annual crop yield at six sites across the U.S. Midwest. Results show that SWAT-C simulates well multi-year average NEE and ET across the spatially distributed sites and capture the majority of temporal variation of these two variables at a daily time scale at each site. Our analyses also reveal that performance of SWAT-C is influenced by multiple factors, such as crop management practices (irrigated vs. rainfed), completeness and accuracy of input data, crop species, and initialization of state variables. Overall, the new SWAT-C demonstrates favorable performance for simulating land–atmosphere carbon exchange across agricultural sites with different soils, climate, and management practices. SWAT-C is expected to serve as a useful tool for including carbon flux into consideration in sustainable watershed management under a changing climate. We also note that extensive assessment of SWAT-C with field observations is required for further improving the model and understanding potential uncertainties of applying it across large regions with complex landscapes. - Highlights: • Expanding the

  8. NIF capsule performance modeling

    Directory of Open Access Journals (Sweden)

    Weber S.

    2013-11-01

    Full Text Available Post-shot modeling of NIF capsule implosions was performed in order to validate our physical and numerical models. Cryogenic layered target implosions and experiments with surrogate targets produce an abundance of capsule performance data including implosion velocity, remaining ablator mass, times of peak x-ray and neutron emission, core image size, core symmetry, neutron yield, and x-ray spectra. We have attempted to match the integrated data set with capsule-only simulations by adjusting the drive and other physics parameters within expected uncertainties. The simulations include interface roughness, time-dependent symmetry, and a model of mix. We were able to match many of the measured performance parameters for a selection of shots.

  9. Application of the Soil and Water Assessment Tool (SWAT) to predict the impact of best management practices in Jatigede Catchment Area

    Science.gov (United States)

    Ridwansyah, Iwan; Fakhrudin, M.; Wibowo, Hendro; Yulianti, Meti

    2018-02-01

    Cimanuk watershed is one of the national priority watersheds for rehabilitation considering its critical condition. In this area, Jatigede Reservoir operates, which is the second largest reservoir in Indonesia, after Jatiluhur Reservoir. The reservoir performs several functions, including flood control, irrigation for 90.000 ha of rice fields, water supply of 3.500 litres per second, and power generation of 110 MW. In 2004 the Jatigede Reservoir catchment area had a critical land area of 40.875 ha (28% of the catchment area). The sedimentation rate in Cimanuk River at Eretan station shows a high rate (5.32 mm/year), which potentially decreases the function of Jatigede Reservoir. Therefore, a strategy of Best Management Practice’s (BMP’s) is required to mitigate the problem by using SWAT hydrology modelling. The aim of this study is to examine the impact of BMP’s on surface runoff and sediment yield in Jatigede Reservoir Catchment Area. Simulations were conducted using land use in 2011. The results of this study suggest that SWAT model is considered as a reasonable modelling of BMP’s simulation concerning Nash-Sutcliffe Coefficients (0.71). The simulation is using terraces, silt pit, and dam trenches as BMP’s techniques. The BMP’s application can reduce surface runoff from 99.7 mm to 75.8 mm, and decrease sediment yield from 61.9 ton/ha/year to 40.8 ton/ha/year.

  10. Ion thruster performance model

    International Nuclear Information System (INIS)

    Brophy, J.R.

    1984-01-01

    A model of ion thruster performance is developed for high flux density cusped magnetic field thruster designs. This model is formulated in terms of the average energy required to produce an ion in the discharge chamber plasma and the fraction of these ions that are extracted to form the beam. The direct loss of high energy (primary) electrons from the plasma to the anode is shown to have a major effect on thruster performance. The model provides simple algebraic equations enabling one to calculate the beam ion energy cost, the average discharge chamber plasma ion energy cost, the primary electron density, the primary-to-Maxwellian electron density ratio and the Maxwellian electron temperature. Experiments indicate that the model correctly predicts the variation in plasma ion energy cost for changes in propellant gas (Ar, Kr, and Xe), grid transparency to neutral atoms, beam extraction area, discharge voltage, and discharge chamber wall temperature

  11. Base Station Performance Model

    OpenAIRE

    Walsh, Barbara; Farrell, Ronan

    2005-01-01

    At present the testing of power amplifiers within base station transmitters is limited to testing at component level as opposed to testing at the system level. While the detection of catastrophic failure is possible, that of performance degradation is not. This paper proposes a base station model with respect to transmitter output power with the aim of introducing system level monitoring of the power amplifier behaviour within the base station. Our model reflects the expe...

  12. Performance modeling of Beamlet

    International Nuclear Information System (INIS)

    Auerbach, J.M.; Lawson, J.K.; Rotter, M.D.; Sacks, R.A.; Van Wonterghem, B.W.; Williams, W.H.

    1995-01-01

    Detailed modeling of beam propagation in Beamlet has been made to predict system performance. New software allows extensive use of optical component characteristics. This inclusion of real optical component characteristics has resulted in close agreement between calculated and measured beam distributions

  13. ATR performance modeling concepts

    Science.gov (United States)

    Ross, Timothy D.; Baker, Hyatt B.; Nolan, Adam R.; McGinnis, Ryan E.; Paulson, Christopher R.

    2016-05-01

    Performance models are needed for automatic target recognition (ATR) development and use. ATRs consume sensor data and produce decisions about the scene observed. ATR performance models (APMs) on the other hand consume operating conditions (OCs) and produce probabilities about what the ATR will produce. APMs are needed for many modeling roles of many kinds of ATRs (each with different sensing modality and exploitation functionality combinations); moreover, there are different approaches to constructing the APMs. Therefore, although many APMs have been developed, there is rarely one that fits a particular need. Clarified APM concepts may allow us to recognize new uses of existing APMs and identify new APM technologies and components that better support coverage of the needed APMs. The concepts begin with thinking of ATRs as mapping OCs of the real scene (including the sensor data) to reports. An APM is then a mapping from explicit quantized OCs (represented with less resolution than the real OCs) and latent OC distributions to report distributions. The roles of APMs can be distinguished by the explicit OCs they consume. APMs used in simulations consume the true state that the ATR is attempting to report. APMs used online with the exploitation consume the sensor signal and derivatives, such as match scores. APMs used in sensor management consume neither of those, but estimate performance from other OCs. This paper will summarize the major building blocks for APMs, including knowledge sources, OC models, look-up tables, analytical and learned mappings, and tools for signal synthesis and exploitation.

  14. Evaluating watershed protection programs in New York City's Cannonsville Reservoir source watershed using SWAT-HS

    Science.gov (United States)

    Hoang, L.; Mukundan, R.; Moore, K. E.; Owens, E. M.; Steenhuis, T. S.

    2017-12-01

    New York City (NYC)'s reservoirs supply over one billion gallons of drinking water each day to over nine million consumers in NYC and upstate communities. The City has invested more than $1.5 billion in watershed protection programs to maintain a waiver from filtration for the Catskill and Delaware Systems. In the last 25 years, the NYC Department of Environmental Protection (NYCDEP) has implemented programs in cooperation with upstate communities that include nutrient management, crop rotations, improvement of barnyards and manure storage, implementing tertiary treatment for Phosphorus (P) in wastewater treatment plants, and replacing failed septic systems in an effort to reduce P loads to water supply reservoirs. There have been several modeling studies evaluating the effect of agricultural Best Management Practices (BMPs) on P control in the Cannonsville watershed in the Delaware System. Although these studies showed that BMPs would reduce dissolved P losses, they were limited to farm-scale or watershed-scale estimates of reduction factors without consideration of the dynamic nature of overland flow and P losses from variable source areas. Recently, we developed the process-based SWAT-Hillslope (SWAT-HS) model, a modified version of the Soil and Water Assessment Tool (SWAT) that can realistically predict variable source runoff processes. The objective of this study is to use the SWAT-HS model to evaluate watershed protection programs addressing both point and non-point sources of P. SWAT-HS predicts streamflow very well for the Cannonsville watershed with a daily Nash Sutcliffe Efficiency (NSE) of 0.85 at the watershed outlet and NSE values ranging from 0.56 - 0.82 at five other locations within the watershed. Based on good hydrological prediction, we applied the model to predict P loads using detailed P inputs that change over time due to the implementation of watershed protection programs. Results from P model predictions provide improved projections of P

  15. Multi-Objective Validation of SWAT for Sparsely-Gauged West African River Basins—A Remote Sensing Approach

    Directory of Open Access Journals (Sweden)

    Thomas Poméon

    2018-04-01

    Full Text Available Predicting freshwater resources is a major concern in West Africa, where large parts of the population depend on rain-fed subsistence agriculture. However, a steady decline in the availability of in-situ measurements of climatic and hydrologic variables makes it difficult to simulate water resource availability with hydrological models. In this study, a modeling framework was set up for sparsely-gauged catchments in West Africa using the Soil and Water Assessment Tool (SWAT, whilst largely relying on remote sensing and reanalysis inputs. The model was calibrated using two different strategies and validated using discharge measurements. New in this study is the use of a multi-objective validation conducted to further investigate the performance of the model, where simulated actual evapotranspiration, soil moisture, and total water storage were evaluated using remote sensing data. Results show that the model performs well (R2 calibration: 0.52 and 0.51; R2 validation: 0.63 and 0.61 and the multi-objective validation reveals good agreement between predictions and observations. The study reveals the potential of using remote sensing data in sparsely-gauged catchments, resulting in good performance and providing data for evaluating water balance components that are not usually validated. The modeling framework presented in this study is the basis for future studies, which will address model response to extreme drought and flood events and further examine the coincidence with Gravity Recovery and Climate Experiment (GRACE total water storage retrievals.

  16. Improvement on reaction model for sodium-water reaction jet code and application analysis

    International Nuclear Information System (INIS)

    Itooka, Satoshi; Saito, Yoshinori; Okabe, Ayao; Fujimata, Kazuhiro; Murata, Shuuichi

    2000-03-01

    In selecting the reasonable DBL on steam generator (SG), it is necessary to improve analytical method for estimating the sodium temperature on failure propagation due to overheating. Improvement on sodium-water reaction (SWR) jet code (LEAP-JET ver.1.30) and application analysis to the water injection tests for confirmation of code propriety were performed. On the improvement of the code, a gas-liquid interface area density model was introduced to develop a chemical reaction model with a little dependence on calculation mesh size. The test calculation using the improved code (LEAP-JET ver.1.40) were carried out with conditions of the SWAT-3·Run-19 test and an actual scale SG. It is confirmed that the SWR jet behavior on the results and the influence to analysis result of a model are reasonable. For the application analysis to the water injection tests, water injection behavior and SWR jet behavior analyses on the new SWAT-1 (SWAT-1R) and SWAT-3 (SWAT-3R) tests were performed using the LEAP-BLOW code and the LEAP-JET code. In the application analysis of the LEAP-BLOW code, parameter survey study was performed. As the results, the condition of the injection nozzle diameter needed to simulate the water leak rate was confirmed. In the application analysis of the LEAP-JET code, temperature behavior of the SWR jet was investigated. (author)

  17. Utilization of Electronic Learning System in Swat Rural Areas

    Directory of Open Access Journals (Sweden)

    Nazir Ahmed Sangi

    2017-12-01

    Full Text Available As developments in electronic technologies i.e. personal computers, laptops, tablets, mobiles and wearable devices, the way of learning is also changing. Therefore, utilization of Information and Communication Technology (ICT has great important role in schools and colleges. ICT is using by students, teachers and societies in District Swat, KP, Pakistan in the form of mobiles internet (for social contact and chat, computers internet (for knowledge exploration and entertainment and multimedia (for teaching and learning. One of the difficulties involved in rural areas’ students of District Swat is that they cannot join class rooms due to their poor livelihood condition and far away from schools and colleges. Especially most of the females of rural areas of Swat do not come to schools and colleges for their family tradition and culture. Various questions were examined in every aspect of educational technologies in this study. We surveyed 50 responded randomly at District Swat from different schools and colleges and discovered that the responded were generally positive and have great interest about e-learning in Swat. The use of proposed electronic system for the learning, the literacy rate will increase in rural areas and students will achieve their individual goals.

  18. Evaluation of remotely sensed actual evapotranspiration data for modeling small scale irrigation in Ethiopia.

    Science.gov (United States)

    Taddele, Y. D.; Ayana, E.; Worqlul, A. W.; Srinivasan, R.; Gerik, T.; Clarke, N.

    2017-12-01

    The research presented in this paper is conducted in Ethiopia, which is located in the horn of Africa. Ethiopian economy largely depends on rainfed agriculture, which employs 80% of the labor force. The rainfed agriculture is frequently affected by droughts and dry spells. Small scale irrigation is considered as the lifeline for the livelihoods of smallholder farmers in Ethiopia. Biophysical models are highly used to determine the agricultural production, environmental sustainability, and socio-economic outcomes of small scale irrigation in Ethiopia. However, detailed spatially explicit data is not adequately available to calibrate and validate simulations from biophysical models. The Soil and Water Assessment Tool (SWAT) model was setup using finer resolution spatial and temporal data. The actual evapotranspiration (AET) estimation from the SWAT model was compared with two remotely sensed data, namely the Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectrometer (MODIS). The performance of the monthly satellite data was evaluated with correlation coefficient (R2) over the different land use groups. The result indicated that over the long term and monthly the AVHRR AET captures the pattern of SWAT simulated AET reasonably well, especially on agricultural dominated landscapes. A comparison between SWAT simulated AET and AVHRR AET provided mixed results on grassland dominated landscapes and poor agreement on forest dominated landscapes. Results showed that the AVHRR AET products showed superior agreement with the SWAT simulated AET than MODIS AET. This suggests that remotely sensed products can be used as valuable tool in properly modeling small scale irrigation.

  19. Parallelization of a hydrological model using the message passing interface

    Science.gov (United States)

    Wu, Yiping; Li, Tiejian; Sun, Liqun; Chen, Ji

    2013-01-01

    With the increasing knowledge about the natural processes, hydrological models such as the Soil and Water Assessment Tool (SWAT) are becoming larger and more complex with increasing computation time. Additionally, other procedures such as model calibration, which may require thousands of model iterations, can increase running time and thus further reduce rapid modeling and analysis. Using the widely-applied SWAT as an example, this study demonstrates how to parallelize a serial hydrological model in a Windows® environment using a parallel programing technology—Message Passing Interface (MPI). With a case study, we derived the optimal values for the two parameters (the number of processes and the corresponding percentage of work to be distributed to the master process) of the parallel SWAT (P-SWAT) on an ordinary personal computer and a work station. Our study indicates that model execution time can be reduced by 42%–70% (or a speedup of 1.74–3.36) using multiple processes (two to five) with a proper task-distribution scheme (between the master and slave processes). Although the computation time cost becomes lower with an increasing number of processes (from two to five), this enhancement becomes less due to the accompanied increase in demand for message passing procedures between the master and all slave processes. Our case study demonstrates that the P-SWAT with a five-process run may reach the maximum speedup, and the performance can be quite stable (fairly independent of a project size). Overall, the P-SWAT can help reduce the computation time substantially for an individual model run, manual and automatic calibration procedures, and optimization of best management practices. In particular, the parallelization method we used and the scheme for deriving the optimal parameters in this study can be valuable and easily applied to other hydrological or environmental models.

  20. Predicting Phosphorus Dynamics Across Physiographic Regions Using a Mixed Hortonian Non-Hortonian Hydrology Model

    Science.gov (United States)

    Collick, A.; Easton, Z. M.; Auerbach, D.; Buchanan, B.; Kleinman, P. J. A.; Fuka, D.

    2017-12-01

    Predicting phosphorus (P) loss from agricultural watersheds depends on accurate representation of the hydrological and chemical processes governing P mobility and transport. In complex landscapes, P predictions are complicated by a broad range of soils with and without restrictive layers, a wide variety of agricultural management, and variable hydrological drivers. The Soil and Water Assessment Tool (SWAT) is a watershed model commonly used to predict runoff and non-point source pollution transport, but is commonly only used with Hortonian (traditional SWAT) or non-Hortonian (SWAT-VSA) initializations. Many shallow soils underlain by a restricting layer commonly generate saturation excess runoff from variable source areas (VSA), which is well represented in a re-conceptualized version, SWAT-VSA. However, many watersheds exhibit traits of both infiltration excess and saturation excess hydrology internally, based on the hydrologic distance from the stream, distribution of soils across the landscape, and characteristics of restricting layers. The objective of this research is to provide an initial look at integrating distributed predictive capabilities that consider both Hortonian and Non-Hortonian solutions simultaneously within a single SWAT-VSA initialization. We compare results from all three conceptual watershed initializations against measured surface runoff and stream P loads and to highlight the model's ability to drive sub-field management of P. All three initializations predict discharge similarly well (daily Nash-Sutcliffe Efficiencies above 0.5), but the new conceptual SWAT-VSA initialization performed best in predicting P export from the watershed, while also identifying critical source areas - those areas generating large runoff and P losses at the sub field level. These results support the use of mixed Hortonian non-Hortonian SWAT-VSA initializations in predicting watershed-scale P losses and identifying critical source areas of P loss in landscapes

  1. 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

  2. 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

  3. Use of Decision Tables to Simulate Management in SWAT+

    Directory of Open Access Journals (Sweden)

    Jeffrey G. Arnold

    2018-05-01

    Full Text Available Decision tables have been used for many years in data processing and business applications to simulate complex rule sets. Several computer languages have been developed based on rule systems and they are easily programmed in several current languages. Land management and river–reservoir models simulate complex land management operations and reservoir management in highly regulated river systems. Decision tables are a precise yet compact way to model the rule sets and corresponding actions found in these models. In this study, we discuss the suitability of decision tables to simulate management in the river basin scale Soil and Water Assessment Tool (SWAT+ model. Decision tables are developed to simulate automated irrigation and reservoir releases. A simple auto irrigation application of decision tables was developed using plant water stress as a condition for irrigating corn in Texas. Sensitivity of the water stress trigger and irrigation application amounts were shown on soil moisture and corn yields. In addition, the Grapevine Reservoir near Dallas, Texas was used to illustrate the use of decision tables to simulate reservoir releases. The releases were conditioned on reservoir volumes and flood season. The release rules as implemented by the decision table realistically simulated flood releases as evidenced by a daily Nash–Sutcliffe Efficiency (NSE of 0.52 and a percent bias of −1.1%. Using decision tables to simulate management in land, river, and reservoir models was shown to have several advantages over current approaches, including: (1 mature technology with considerable literature and applications; (2 ability to accurately represent complex, real world decision-making; (3 code that is efficient, modular, and easy to maintain; and (4 tables that are easy to maintain, support, and modify.

  4. The importance of variables and parameters in radiolytic chemical kinetics modeling

    International Nuclear Information System (INIS)

    Piepho, M.G.; Turner, P.J.; Reimus, P.W.

    1989-01-01

    Many of the pertinent radiochemical reactions are not completely understood, and most of the associated rate constants are poorly characterized. To help identify the important radiochemical reactions, rate constants, species, and environmental conditions, an importance theory code, SWATS (Sensitivitiy With Adjoint Theory-Sparse version)-LOOPCHEM, has been developed for the radiolytic chemical kinetics model in the radiolysis code LOOPCHEM. The LOOPCHEM code calculates the concentrations of various species in a radiolytic field over time. The SWATS-LOOPCHEM code efficiently calculates: the importance (relative to a defined response of interest) of each species concentration over time, the sensitivity of each parameter of interest, and the importance of each equation in the radiolysis model. The calculated results will be used to guide future experimental and modeling work for determining the importance of radiolysis on waste package performance. A demonstration (the importance of selected concentrations and the sensitivities of selected parameters) of the SWATS-LOOPCHEM code is provided for illustrative purposes

  5. A Guideline for Successful Calibration and Uncertainty Analysis for Soil and Water Assessment: A Review of Papers from the 2016 International SWAT Conference

    Directory of Open Access Journals (Sweden)

    Karim C. Abbaspour

    2017-12-01

    Full Text Available Application of integrated hydrological models to manage a watershed’s water resources are increasingly finding their way into the decision-making processes. The Soil and Water Assessment Tool (SWAT is a multi-process model integrating hydrology, ecology, agriculture, and water quality. SWAT is a continuation of nearly 40 years of modeling efforts conducted by the United States Department of Agriculture (USDA Agricultural Research Service (ARS. A large number of SWAT-related papers have appeared in ISI journals, building a world-wide consensus around the model’s stability and usefulness. The current issue is a collection of the latest research using SWAT as the modeling tool. Most models must undergo calibration/validation and uncertainty analysis. Unfortunately, these sciences are not formal subjects of teaching in most universities and the students are often left to their own resources to calibrate their model. In this paper, we focus on calibration and uncertainty analysis highlighting some serious issues in the calibration of distributed models. A protocol for calibration is also highlighted to guide the users to obtain better modeling results. Finally, a summary of the papers published in this special issue is provided in the Appendix.

  6. Application of genetic algorithm to land use optimization for non-point source pollution control based on CLUE-S and SWAT

    Science.gov (United States)

    Wang, Qingrui; Liu, Ruimin; Men, Cong; Guo, Lijia

    2018-05-01

    The genetic algorithm (GA) was combined with the Conversion of Land Use and its Effect at Small regional extent (CLUE-S) model to obtain an optimized land use pattern for controlling non-point source (NPS) pollution. The performance of the combination was evaluated. The effect of the optimized land use pattern on the NPS pollution control was estimated by the Soil and Water Assessment Tool (SWAT) model and an assistant map was drawn to support the land use plan for the future. The Xiangxi River watershed was selected as the study area. Two scenarios were used to simulate the land use change. Under the historical trend scenario (Markov chain prediction), the forest area decreased by 2035.06 ha, and was mainly converted into paddy and dryland area. In contrast, under the optimized scenario (genetic algorithm (GA) prediction), up to 3370 ha of dryland area was converted into forest area. Spatially, the conversion of paddy and dryland into forest occurred mainly in the northwest and southeast of the watershed, where the slope land occupied a large proportion. The organic and inorganic phosphorus loads decreased by 3.6% and 3.7%, respectively, in the optimized scenario compared to those in the historical trend scenario. GA showed a better performance in optimized land use prediction. A comparison of the land use patterns in 2010 under the real situation and in 2020 under the optimized situation showed that Shennongjia and Shuiyuesi should convert 1201.76 ha and 1115.33 ha of dryland into forest areas, respectively, which represented the greatest changes in all regions in the watershed. The results of this study indicated that GA and the CLUE-S model can be used to optimize the land use patterns in the future and that SWAT can be used to evaluate the effect of land use optimization on non-point source pollution control. These methods may provide support for land use plan of an area.

  7. Predictive performance models and multiple task performance

    Science.gov (United States)

    Wickens, Christopher D.; Larish, Inge; Contorer, Aaron

    1989-01-01

    Five models that predict how performance of multiple tasks will interact in complex task scenarios are discussed. The models are shown in terms of the assumptions they make about human operator divided attention. The different assumptions about attention are then empirically validated in a multitask helicopter flight simulation. It is concluded from this simulation that the most important assumption relates to the coding of demand level of different component tasks.

  8. SWATS: Diurnal Trends in the Soil Temperature Report

    Energy Technology Data Exchange (ETDEWEB)

    Cook, David [Argonne National Lab. (ANL), Argonne, IL (United States); Theisen, Adam [Univ. of Oklahoma, Norman, OK (United States)

    2017-06-30

    During the processing of data for the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility ARMBE2D Value-Added Product (VAP), the developers noticed that the SWATS soil temperatures did not show a decreased temporal variability with increased depth with the new E30+ Extended Facilities (EFs), unlike the older EFs at ARM’s Southern Great Plains (SGP) site. The instrument mentor analyzed the data and reported that all SWATS locations have shown this behavior but that the magnitude of the problem was greatest at EFs E31-E38. The data were analyzed to verify the initial assessments of: 1. 5 cm SWATS data were valid for all EFs and 15 cm soil temperature measurements were valid at all EFs other than E31-E38, 2. Use only nighttime SWATS soil temperature measurements to calculate daily average soil temperatures, 3. Since it seems likely that the soil temperature measurements below 15cm were affected by the solar heating of the enclosure at all but E31-38, and at all depths below 5cm at E31-38, individual measurements of soil temperature at these depths during daylight hours, and daily averages of the same, can ot be trusted on most (particularly sunny) days.

  9. Residues of cypermethrin and endosulfan in soils of Swat valley

    Directory of Open Access Journals (Sweden)

    M. Nafees

    2009-05-01

    Full Text Available Swat Valley was studied for two widely used pesticides; cypermethrin and endosulfan. A total of 63 soil samples were collected from 27 villages selected for this purpose. The collected soil samples were extracted with n-hexane, pesticides were separated, identified and quantified by a GC-ECD system. Endosulfan was 0.24 - 1.51 mg kg-1 and 0.13 - 12.67 mg kg-1 in rainfed and irrigated areas, respectively. The residual level of cypermethrin was comparatively high with a level of0.14 to 27.62 mg kg-1 and 0.05 to 73.75 mg kg-1 in rainfed and irrigated areas, respectively. For assessing the possible causes of pesticide residues in soil, 360 farmers were interviewed. It was found that both, cypermethrin and endosulfan, apart from agriculture were also widely misused for fishing in the entire stretch of River Swat and its tributaries. River Swat is used for irrigation in Swat Valley and this wide misuse of pesticides can also contribute to pesticide residue in soil.

  10. DEM Resolution Impact on the Estimation of the Physical Characteristics of Watersheds by Using SWAT

    Directory of Open Access Journals (Sweden)

    Waranyu Buakhao

    2016-01-01

    Full Text Available A digital elevation model (DEM is an important spatial input for automatic extraction of topographic parameters for the soil and water assessment tool (SWAT. The objective of this study was to investigate the impact of DEM resolution (from 5 to 90 m on the delineation process of a SWAT model with two types of watershed characteristics (flat area and mountain area and three sizes of watershed area (about 20,000, 200,000, and 1,500,000 hectares. The results showed that the total lengths of the streamline, main channel slope, watershed area, and area slope were significantly different when using the DEM datasets to delineate. Delineation using the SRTM DEM (90 m, ASTER DEM (30 m, and LDD DEM (5 m for all watershed characteristics showed that the watershed sizes and shapes obtained were only slightly different, whereas the area slopes obtained were significantly different. The total lengths of the generated streams increased when the resolution of the DEM used was higher. The stream slopes obtained using the small area sizes were insignificant, whereas the slopes obtained using the large area sizes were significantly different. This suggests that water resource model users should use the ASTER DEM as opposed to a finer resolution DEM for model input to save time for the model calibration and validation.

  11. Cooperation on impingement wastage experiment of Mod. 9Cr-1Mo steel using SWAT-1R sodium-water reaction test facility

    International Nuclear Information System (INIS)

    Beauchamp, F.; Allou, A.; Nishimura, M.; Umeda, R.

    2013-01-01

    Conclusion: • 6 experiments were carried out in the SWAT-1R facility of JAEA Oarai R&D Center to study the wastage resistance of the Mod. 9Cr-1Mo steel (T91) straight tubes. • These experiments were performed under the cooperation between CEA and JAEA. • The experiments were conducted successfully: - all the tubes were punctured by the reaction jet, - wastage and steam/water leak rates were obtained, - experimental results brought some new determining sets of wastage data on T91. • This fruitful cooperation has contributed to: - expanding the wastage database on T91, - upgrading wastage rates prediction from modelling, - the safety demonstration of future steam generators units

  12. Test results of Run-1 and Run-2 in steam generator safety test facility (SWAT-3)

    International Nuclear Information System (INIS)

    Kurihara, A.; Yatabe, Toshio; Tanabe, Hiromi; Hiroi, Hiroshi

    2003-07-01

    Large leak sodium-water reaction tests were carried out using SWAT-1 rig and SWAT-3 facility in Power Reactor and Nuclear Fuel Development Corporation (PNC) O-arai Engineering Center to obtain the data on the design of the prototype LMFBR Monju steam generator against a large leak accident. This report provides the results of SWAT-3 Runs 1 and 2. In Runs 1 and 2, the heat transfer tube bundle of the evaporator, fabricated by TOSHIBA/IHI, were used, and the pressure relief line was located at the top of evaporator. The water injection rates in the evaporator were 6.7 kg/s and 14.2 (initial)-9.7 kg/s in Runs 1 and 2 respectively, which corresponded to 3.3 tubes and 7.1 (initial)-4.8 tubes failure in actual size system according to iso-velocity modeling. Approximately two hundreds of measurement points were provided to collect data such as pressure, temperature, strain, sodium level, void, thrust load, acceleration, displacement, flow rate, and so on in each run. Initial spike pressures were 1.13 MPa and 2.62 MPa nearest to injection point in Runs 1 and 2 respectively, and the maximum quasi-steady pressures in evaporator were 0.49 MPa and 0.67 MPa in Runs 1 and 2. No secondary tube failure was observed. The rupture disc of evaporator (RD601) burst at 1.1s in Run-1 and at 0.7s in Run-2 after water injected, and the pressure relief system was well-functioned though a few items for improvement were found. (author)

  13. Assessing the efficacy of the SWAT auto-irrigation function to simulate Irrigation, evapotranspiration and crop response to irrigation management strategies of the Texas High Plains

    Science.gov (United States)

    The Soil and Water Assessment Tool (SWAT) model is widely used for simulation of hydrologic processes at various temporal and spatial scales. Less common are long-term simulation analyses of water balance components including agricultural management practices such as irrigation management. In the se...

  14. Principles of Sonar Performance Modeling

    NARCIS (Netherlands)

    Ainslie, M.A.

    2010-01-01

    Sonar performance modelling (SPM) is concerned with the prediction of quantitative measures of sonar performance, such as probability of detection. It is a multidisciplinary subject, requiring knowledge and expertise in the disparate fields of underwater acoustics, acoustical oceanography, sonar

  15. Sensitivity analysis for hydrology and pesticide supply towards the river in SWAT

    Science.gov (United States)

    Holvoet, K.; van Griensven, A.; Seuntjens, P.; Vanrolleghem, P. A.

    The dynamic behaviour of pesticides in river systems strongly depends on varying climatological conditions and agricultural management practices. To describe this behaviour at the river-basin scale, integrated hydrological and water quality models are needed. A crucial step in understanding the various processes determining pesticide fate is to perform a sensitivity analysis. Sensitivity analysis for hydrology and pesticide supply in SWAT (Soil and Water Assessment Tool) will provide useful support for the development of a reliable hydrological model and will give insight in which parameters are most sensitive concerning pesticide supply towards rivers. The study was performed on the Nil catchment in Belgium. In this study we utilised an LH-OAT sensitivity analysis. The LH-OAT method combines the One-factor-At-a-Time (OAT) design and Latin Hypercube (LH) sampling by taking the Latin Hypercube samples as initial points for an OAT design. By means of the LH-OAT sensitivity analysis, the dominant hydrological parameters were determined and a reduction of the number of model parameters was performed. Dominant hydrological parameters were the curve number (CN2), the surface runoff lag (surlag), the recharge to deep aquifer (rchrg_dp) and the threshold depth of water in the shallow aquifer (GWQMN). Next, the selected parameters were estimated by manual calibration. Hereby, the Nash-Sutcliffe coefficient of efficiency improved from an initial value of -22.4 to +0.53. In the second part, sensitivity analyses were performed to provide insight in which parameters or model inputs contribute most to variance in pesticide output. The results of this study show that for the Nil catchment, hydrologic parameters are dominant in controlling pesticide predictions. The other parameter that affects pesticide concentrations in surface water is ‘apfp_pest’, which meaning was changed into a parameter that controls direct losses to the river system (e.g., through the clean up of spray

  16. Characterising performance of environmental models

    NARCIS (Netherlands)

    Bennett, N.D.; Croke, B.F.W.; Guariso, G.; Guillaume, J.H.A.; Hamilton, S.H.; Jakeman, A.J.; Marsili-Libelli, S.; Newham, L.T.H.; Norton, J.; Perrin, C.; Pierce, S.; Robson, B.; Seppelt, R.; Voinov, A.; Fath, B.D.; Andreassian, V.

    2013-01-01

    In order to use environmental models effectively for management and decision-making, it is vital to establish an appropriate level of confidence in their performance. This paper reviews techniques available across various fields for characterising the performance of environmental models with focus

  17. Application of SWAT99.2 to sensitivity analysis of water balance components in unique plots in a hilly region

    Directory of Open Access Journals (Sweden)

    Jun-feng Dai

    2017-07-01

    Full Text Available Although many sensitivity analyses using the soil and water assessment tool (SWAT in a complex watershed have been conducted, little attention has been paid to the application potential of the model in unique plots. In addition, sensitivity analysis of percolation and evapotranspiration with SWAT has seldom been undertaken. In this study, SWAT99.2 was calibrated to simulate water balance components for unique plots in Southern China from 2000 to 2001, which included surface runoff, percolation, and evapotranspiration. Twenty-one parameters classified into four categories, including meteorological conditions, topographical characteristics, soil properties, and vegetation attributes, were used for sensitivity analysis through one-at-a-time (OAT sampling to identify the factor that contributed most to the variance in water balance components. The results were shown to be different for different plots, with parameter sensitivity indices and ranks varying for different water balance components. Water balance components in the broad-leaved forest and natural grass plots were most sensitive to meteorological conditions, less sensitive to vegetation attributes and soil properties, and least sensitive to topographical characteristics. Compared to those in the natural grass plot, water balance components in the broad-leaved forest plot demonstrated higher sensitivity to the maximum stomatal conductance (GSI and maximum leaf area index (BLAI.

  18. Response of tomato cultivars to different organic fertilizers under agro-climatic conditions of mingora, Swat

    International Nuclear Information System (INIS)

    Yousafzai, S.K.; Khan, S.M.; Khan, J.; Khan, S.A.; Hussain, I.; Naz, I.

    2016-01-01

    An experiment was conducted at Agricultural Research Institute (ARI) Mingora, Swat during 2013 to study the effect of different organic fertilizers of tomato cultivars under the agro-climatic conditions of Mingora, Swat. The experiment was conducted in randomized complete block design with split plot arrangements having four treatments with three replications. Almost all the traits showed significant differences for organic fertilizers and varieties, while their interactions had a varied response. The analyzed data showed that poultry manure gave maximum yield (24.65 t ha/sup -1/), followed by FYM (24.38 t ha/sup -1/) and mushroom compost (24.11 t ha/sup -1/ ) while minimum was recorded in plots where no organic fertilizer was used. The results revealed that cultivar, Rio Grand showed maximum number of plant survival percentage (98.33 percent), days to flowering (40.73), number of flowers plant/sup -1/ (6.23), number of fruit plant (25.67), fruit 3 weight (8.84 kg), number of leaves plant/sup -1/ (83.66), fruit size (64.70 cm/sup 3/) and total yield (25.67 t ha/sup -1/ ) in Farm Yard Manure (FYM). Considering the overall performance, it was found that the tomato cultivar Rio Grand was promising for yield and other characters where FYM was applied. (author)

  19. Estimation of PWR spent fuel composition using SCALE and SWAT code systems

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hee Sung [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kenya, Suyama; Hiroshi, Okuno [Japan Atomic Energy Research Institute, Tokyo (Japan)

    2001-05-01

    The isotopic composition calculations were performed for 26 spent fuel samples from Obrigheim PWR reactor and 55 spent fuel samples from 7 PWR reactors using SCALE4.4 SAS2H with 27, 44 and 238 group cross-section libraries and SWAT with 107 group cross-section library. For convenience, the ratio of the measured to calculated value was used as a parameter. The four kinds of the calculation results were compared with the measured data. For many important nuclides for burnup credit criticality safety evaluation, the four methods applied in this study showed good coincidence with measurements in general. More precise observations showed the following results. Less unity ratios were found for Pu-239 and -241 for selected 16 samples out of the 26 samples from Obrigheim reactor. Larger than unity ratios were found for Am-241 for both the 16 and 55 samples. Larger than unity ratios were found for Sm-149 for the 55 samples. In the case of 26 sample SWAT was generally accompanied by larger ratios than those of SAS2H with some exceptions. Based on the measured-to-calculated ratios for 71 samples of a combined set in which 16 selected samples and 55 samples were included, the correction factors that should be multiplied to the calculated isotopic compositions were generated for a conservative estimate of the neutron multiplication factor of a system containing PWR spent fuel, taking burnup credit into account.

  20. INCIDENCE OF NAMATODE PARASITES IN COMMERCIAL LAYERS IN SWAT

    OpenAIRE

    R.S. Sayyed, M.S. Phulan1, W.M. Bhatti1, M. Pardehi and Shamsher Ali

    2000-01-01

    Research was conducted on 400 guts of commercial layers collected from various shops at District Swat during April to September 1998. Out of 400 guts, 36 per cent were positive for nematodes, Mixed infestation of nematodes and cestodes was found in 4.75 per cent layers. Incidence rate of Ascaridia galli, Heterakis gallinarum and Subulura brumpli was 25.75, 8.25 and 2 per cent, respectively.

  1. INCIDENCE OF NAMATODE PARASITES IN COMMERCIAL LAYERS IN SWAT

    Directory of Open Access Journals (Sweden)

    R.S. Sayyed, M.S. Phulan1, W.M. Bhatti1, M. Pardehi and Shamsher Ali

    2000-04-01

    Full Text Available Research was conducted on 400 guts of commercial layers collected from various shops at District Swat during April to September 1998. Out of 400 guts, 36 per cent were positive for nematodes, Mixed infestation of nematodes and cestodes was found in 4.75 per cent layers. Incidence rate of Ascaridia galli, Heterakis gallinarum and Subulura brumpli was 25.75, 8.25 and 2 per cent, respectively.

  2. Characterization of emerald from Gujar Kili, Swat, Pakistan

    International Nuclear Information System (INIS)

    Qureshi, A.A.; Akram, M.; Khattak, N.U.; Khan, H.A.

    1997-01-01

    The green gem variety of beryl family having Cr as colouring agent is known as emerald. Thirteen emerald occurrences are known from northern Pakistan. These occurrences are in Mohamand Agency, Bajuar Agency, Swat District, Indus Kohistan and Gilgit which are located exclusively in the metamorphosed ophiolitic melange of the Indus Suture Zone. The ophiolitic rocks of this suture are the source of Cr which colours the beryl to make it emerald. Studies have been carried out for the characterisation of emerald from one locality, Gujar Kili in Swat district, using petrographic, XRD, XRF and fission track techniques. The Gujar Kili emerald is of green to deep green colour good quality gemstone and contains inclusions in some cases. In general, the Gujar Kili emerald has high Mg, Fe, Cr, V and Al values as compared to average composition of natural emeralds of Swat District. Two mineralogical phases, namely beryl and chrysoberyl have been identified in the four Gujar Kili samples analysed by us. The XRD data for the beryl and chrysoberyl is also presented. The Cr which colours the beryl to make it emerald, does not substitute any element in the beryl structure, rather it is present as an impurity in the crystal matrix. A new etchant to reveal fission tracks in a very short time is also being reported in this paper. (author)

  3. Multiprocessor performance modeling with ADAS

    Science.gov (United States)

    Hayes, Paul J.; Andrews, Asa M.

    1989-01-01

    A graph managing strategy referred to as the Algorithm to Architecture Mapping Model (ATAMM) appears useful for the time-optimized execution of application algorithm graphs in embedded multiprocessors and for the performance prediction of graph designs. This paper reports the modeling of ATAMM in the Architecture Design and Assessment System (ADAS) to make an independent verification of ATAMM's performance prediction capability and to provide a user framework for the evaluation of arbitrary algorithm graphs. Following an overview of ATAMM and its major functional rules are descriptions of the ADAS model of ATAMM, methods to enter an arbitrary graph into the model, and techniques to analyze the simulation results. The performance of a 7-node graph example is evaluated using the ADAS model and verifies the ATAMM concept by substantiating previously published performance results.

  4. The Pennsylvania Phosphorus Index and TopoSWAT: A comparison of transport components and approaches

    Science.gov (United States)

    The regional Chesapeake Bay Conservation Innovation Grant Initiative includes comparison of TopoSWAT results and Phosphorus Index (P Index) evaluations of eight study watersheds throughout the Chesapeake Bay watershed. While similarities exist between the P Index and TopoSWAT, further comparison of ...

  5. Evaluation of evapotranspiration methods for model validation in a semi-arid watershed in northern China

    Directory of Open Access Journals (Sweden)

    K. Schneider

    2007-05-01

    Full Text Available This study evaluates the performance of four evapotranspiration methods (Priestley-Taylor, Penman-Monteith, Hargreaves and Makkink of differing complexity in a semi-arid environment in north China. The results are compared to observed water vapour fluxes derived from eddy flux measurements. The analysis became necessary after discharge simulations using an automatically calibrated version of the Soil and Water Assessment Tool (SWAT failed to reproduce runoff measurements. Although the study area receives most of the annual rainfall during the vegetation period, high temperatures can cause water scarcity. We investigate which evapotranspiration method is most suitable for this environment and whether the model performance of SWAT can be improved with the most adequate evapotranspiration method.

    The evapotranspiration models were tested in two consecutive years with different rainfall amounts. In general, the simple Hargreaves and Makkink equations outmatch the more complex Priestley-Taylor and Penman-Monteith methods, although their performance depended on water availability. Effects on the quality of SWAT runoff simulations, however, remained minor. Although evapotranspiration is an important process in the hydrology of this steppe environment, our analysis indicates that other driving factors still need to be identified to improve SWAT simulations.

  6. Agroecology and biodiversity of the catchment area of Swat River

    International Nuclear Information System (INIS)

    Ahmad, H.; Ahmed, R.

    2003-01-01

    Agroecological studies of the of the Swat River catchment area showed that the terrestrial ecosystem of the area is divided into subtropical, humid temperate, cool temperate, cold temperate, subalpine, alpine and cold desert zones. Indicator species along with their altitudinal limits are specified for each zone. Unplanned population growth, agriculture extension, habitat losses, deforestation, environmental pollution and unwise use of natural resources are threats to the natural biodiversity of these zones. Its severity is very evident in the subtropical and humid temperate zones. The losses encountered to the biodiversity of the area under the influence of various anthropogenic stresses are highlighted. (author)

  7. Performability Modelling Tools, Evaluation Techniques and Applications

    NARCIS (Netherlands)

    Haverkort, Boudewijn R.H.M.

    1990-01-01

    This thesis deals with three aspects of quantitative evaluation of fault-tolerant and distributed computer and communication systems: performability evaluation techniques, performability modelling tools, and performability modelling applications. Performability modelling is a relatively new

  8. Performance of chickpea genotypes under Swat valley conditions

    International Nuclear Information System (INIS)

    Khan, A.; Rahim, M.; Ahmad, F.; Ali, A.

    2004-01-01

    Twenty-two genetically diverse chickpeas genotypes were studied for their physiological efficiency to select the most desirable genotype/genotypes for breeding program on chickpea. Genotype 'CM7-1' was found physiologically efficient stain with maximum harvest index (37.33%) followed by genotype 'CM1571-1-A' with harvest index of 35.73%. Genotype '90206' produced maximum biological yield (7463 kg ha/sup -1/) followed by genotypes 'CM31-1' and 'E-2034' with biological yield of 7352 and 7167 kg ha/sup -1/, respectively. Harvest index and economic yield showed significant positive correlation value of (r=+0.595), while negative correlation value of (r = -0.435) was observed between harvest index and biological yield. (author)

  9. Hydrological Modeling of Highly Glacierized Basins (Andes, Alps, and Central Asia

    Directory of Open Access Journals (Sweden)

    Nina Omani

    2017-02-01

    Full Text Available The Soil and Water Assessment Tool (SWAT was used to simulate five glacierized river basins that are global in coverage and vary in climate. The river basins included the Narayani (Nepal, Vakhsh (Central Asia, Rhone (Switzerland, Mendoza (Central Andes, Argentina, and Central Dry Andes (Chile, with a total area of 85,000 km2. A modified SWAT snow algorithm was applied in order to consider spatial variation of associated snowmelt/accumulation by elevation band across each subbasin. In previous studies, melt rates varied as a function of elevation because of an air temperature gradient while the snow parameters were constant throughout the entire basin. A major improvement of the new snow algorithm is the separation of the glaciers from seasonal snow based on their characteristics. Two SWAT snow algorithms were evaluated in simulation of monthly runoff from the glaciered watersheds: (1 the snow parameters are lumped (constant throughout the entire basin and (2 the snow parameters are spatially variable based on elevation bands of a subbasin (modified snow algorithm. Applying the distributed SWAT snow algorithm improved the model performance in simulation of monthly runoff with snow-glacial regime, so that mean RSR decreased to 0.49 from 0.55 and NSE increased to 0.75 from 0.69. Improvement of model performance was negligible in simulations of monthly runoff from the basins with a monsoon runoff regime.

  10. Data management system performance modeling

    Science.gov (United States)

    Kiser, Larry M.

    1993-01-01

    This paper discusses analytical techniques that have been used to gain a better understanding of the Space Station Freedom's (SSF's) Data Management System (DMS). The DMS is a complex, distributed, real-time computer system that has been redesigned numerous times. The implications of these redesigns have not been fully analyzed. This paper discusses the advantages and disadvantages for static analytical techniques such as Rate Monotonic Analysis (RMA) and also provides a rationale for dynamic modeling. Factors such as system architecture, processor utilization, bus architecture, queuing, etc. are well suited for analysis with a dynamic model. The significance of performance measures for a real-time system are discussed.

  11. Aplicación del modelo hidrológico SWAT a la cuenca del río Meca (Huelva, España)

    OpenAIRE

    Galván González, Laura; Olías Álvarez, Manuel; Fernández de Villarán San Juan, Rubén; Domingo Santos, Juan Manuel

    2007-01-01

    Acid mine drainage (AMD) is the main pollutant source in the Odiel river basin (SW Spain). Stream-flow data constitute a tool to assess the pollutant load transported by the drainage network, as well as to evaluate the possible impact of restoration measurements along the river. Due to the malfunctioning of the available stream-gauges and in order to sham the Odiel river behavior, a water model is being elaborated using the tool SWAT (Soil and Water Assessment Tool), developed by ...

  12. Off gas condenser performance modelling

    International Nuclear Information System (INIS)

    Cains, P.W.; Hills, K.M.; Waring, S.; Pratchett, A.G.

    1989-12-01

    A suite of three programmes has been developed to model the ruthenium decontamination performance of a vitrification plant off-gas condenser. The stages of the model are: condensation of water vapour, NO x absorption in the condensate, RuO 4 absorption in the condensate. Juxtaposition of these stages gives a package that may be run on an IBM-compatible desktop PC. Experimental work indicates that the criterion [HNO 2 ] > 10 [RuO 4 ] used to determine RuO 4 destruction in solution is probably realistic under condenser conditions. Vapour pressures of RuO 4 over aqueous solutions at 70 o -90 o C are slightly lower than the values given by extrapolating the ln K p vs. T -1 relation derived from lower temperature data. (author)

  13. Data harmonization and model performance

    Science.gov (United States)

    The Joint Committee on Urban Storm Drainage of the International Association for Hydraulic Research (IAHR) and International Association on Water Pollution Research and Control (IAWPRC) was formed in 1982. The current committee members are (no more than two from a country): B. C. Yen, Chairman (USA); P. Harremoes, Vice Chairman (Denmark); R. K. Price, Secretary (UK); P. J. Colyer (UK), M. Desbordes (France), W. C. Huber (USA), K. Krauth (FRG), A. Sjoberg (Sweden), and T. Sueishi (Japan).The IAHR/IAWPRC Joint Committee is forming a Task Group on Data Harmonization and Model Performance. One objective is to promote international urban drainage data harmonization for easy data and information exchange. Another objective is to publicize available models and data internationally. Comments and suggestions concerning the formation and charge of the Task Group are welcome and should be sent to: B. C. Yen, Dept. of Civil Engineering, Univ. of Illinois, 208 N. Romine St., Urbana, IL 61801.

  14. Behavior model for performance assessment

    International Nuclear Information System (INIS)

    Brown-VanHoozer, S. A.

    1999-01-01

    Every individual channels information differently based on their preference of the sensory modality or representational system (visual auditory or kinesthetic) we tend to favor most (our primary representational system (PRS)). Therefore, some of us access and store our information primarily visually first, some auditorily, and others kinesthetically (through feel and touch); which in turn establishes our information processing patterns and strategies and external to internal (and subsequently vice versa) experiential language representation. Because of the different ways we channel our information, each of us will respond differently to a task--the way we gather and process the external information (input), our response time (process), and the outcome (behavior). Traditional human models of decision making and response time focus on perception, cognitive and motor systems stimulated and influenced by the three sensory modalities, visual, auditory and kinesthetic. For us, these are the building blocks to knowing how someone is thinking. Being aware of what is taking place and how to ask questions is essential in assessing performance toward reducing human errors. Existing models give predications based on time values or response times for a particular event, and may be summed and averaged for a generalization of behavior(s). However, by our not establishing a basic understanding of the foundation of how the behavior was predicated through a decision making strategy process, predicative models are overall inefficient in their analysis of the means by which behavior was generated. What is seen is the end result

  15. Behavior model for performance assessment.

    Energy Technology Data Exchange (ETDEWEB)

    Borwn-VanHoozer, S. A.

    1999-07-23

    Every individual channels information differently based on their preference of the sensory modality or representational system (visual auditory or kinesthetic) we tend to favor most (our primary representational system (PRS)). Therefore, some of us access and store our information primarily visually first, some auditorily, and others kinesthetically (through feel and touch); which in turn establishes our information processing patterns and strategies and external to internal (and subsequently vice versa) experiential language representation. Because of the different ways we channel our information, each of us will respond differently to a task--the way we gather and process the external information (input), our response time (process), and the outcome (behavior). Traditional human models of decision making and response time focus on perception, cognitive and motor systems stimulated and influenced by the three sensory modalities, visual, auditory and kinesthetic. For us, these are the building blocks to knowing how someone is thinking. Being aware of what is taking place and how to ask questions is essential in assessing performance toward reducing human errors. Existing models give predications based on time values or response times for a particular event, and may be summed and averaged for a generalization of behavior(s). However, by our not establishing a basic understanding of the foundation of how the behavior was predicated through a decision making strategy process, predicative models are overall inefficient in their analysis of the means by which behavior was generated. What is seen is the end result.

  16. Ethnobotanical Study of Tehsil Kabal, Swat District, KPK, Pakistan

    Directory of Open Access Journals (Sweden)

    Imtiaz Ahmad

    2011-01-01

    Full Text Available A total of 140 plants have been reported ethnobotanically from Tehsil Kabal, Swat District. These include the 133 plants (95% of angiosperms, 3 (2.14% of gymnosperms, and 2 (1.42% each of pteridophytes and fungi. The largest family is Lamiaceae represented by 11 species followed by Rosaceae represented by 9 species. Among angiosperms 76 (55.63% were herbs, 17 (12.78% were shrubs, and 40 (30.07% were trees; 127 plants (95.48% were dicot while 6 plants (4.51% were monocot. Most of the plants were used for more than one purpose. Generally the plants were used for medicinal, fuel, timber wood, food, and fodder for cattle purposes.

  17. Model Performance Evaluation and Scenario Analysis (MPESA)

    Science.gov (United States)

    Model Performance Evaluation and Scenario Analysis (MPESA) assesses the performance with which models predict time series data. The tool was developed Hydrological Simulation Program-Fortran (HSPF) and the Stormwater Management Model (SWMM)

  18. Coupling hydrological modeling and support vector regression to model hydropeaking in alpine catchments.

    Science.gov (United States)

    Chiogna, Gabriele; Marcolini, Giorgia; Liu, Wanying; Pérez Ciria, Teresa; Tuo, Ye

    2018-08-15

    Water management in the alpine region has an important impact on streamflow. In particular, hydropower production is known to cause hydropeaking i.e., sudden fluctuations in river stage caused by the release or storage of water in artificial reservoirs. Modeling hydropeaking with hydrological models, such as the Soil Water Assessment Tool (SWAT), requires knowledge of reservoir management rules. These data are often not available since they are sensitive information belonging to hydropower production companies. In this short communication, we propose to couple the results of a calibrated hydrological model with a machine learning method to reproduce hydropeaking without requiring the knowledge of the actual reservoir management operation. We trained a support vector machine (SVM) with SWAT model outputs, the day of the week and the energy price. We tested the model for the Upper Adige river basin in North-East Italy. A wavelet analysis showed that energy price has a significant influence on river discharge, and a wavelet coherence analysis demonstrated the improved performance of the SVM model in comparison to the SWAT model alone. The SVM model was also able to capture the fluctuations in streamflow caused by hydropeaking when both energy price and river discharge displayed a complex temporal dynamic. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Calibration of PMIS pavement performance prediction models.

    Science.gov (United States)

    2012-02-01

    Improve the accuracy of TxDOTs existing pavement performance prediction models through calibrating these models using actual field data obtained from the Pavement Management Information System (PMIS). : Ensure logical performance superiority patte...

  20. Analysis of climate change impact on runoff and sediment delivery in a Great Lake watershed using SWAT

    Science.gov (United States)

    Verma, S.; Bhattarai, R.; Cooke, R.

    2011-12-01

    The green house gas loading of the atmosphere has been increasing since the mid 19th century which threatens to dramatically change the earth's climate in the 21st Century. Scientific evidences show that earth's global average surface temperature has risen some 0.75°C (1.3°F) since 1850. Third Assessment Report (TAR) from the Intergovernmental Panel on Climate Change (IPCC) concluded that human activities have increased the atmospheric concentration of greenhouse gases (GHGs), which will result in a warming world and other changes in the climate. TAR has projected an increase in globally average surface temperature of 1.4 to 5.8 °C and an increase in precipitation of 5 to 20 % over the period of 1990 to 2100. Assuming a global temperature increase of between 2.8 and 5.2 °C, it was estimated a 7-15% increase in global evaporation and precipitation rates. Global warming and subsequent climate change could raise sea level by several tens of centimeters in the next fifty years. Such a rise may erode beaches, worsen coastal flooding and threaten water quality in estuaries and aquifers. With the climate already changing and further change in climate highly likely to happen, study of impact of climate and the adaptation is a necessary component of any response to climate change. The objective of this study is to analyze the impact of climate change on runoff and sediment delivery in a Great Lake watershed located in Northern Ohio. Maumee River watershed is predominantly an agricultural watershed with an area of 6330 sq mile and drains to Lake Erie. Agricultural area covers about 89.9% of the watershed while wooded area covers 7.3%, 1.2% is urban area and other land uses account for 1.6%. Water Quality Laboratory, Heidelberg College has monitored the watershed for last 25 years. The Soil and Water Assessment Tool (SWAT) model is used for both water quantity and water quality simulations for past and future scenarios. SWAT is a continuous, long-term watershed scale

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

    Institute of Scientific and Technical Information of China (English)

    付意成; 臧文斌; 董飞; 付敏; 张剑

    2016-01-01

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

  2. Performance Modelling of Steam Turbine Performance using Fuzzy ...

    African Journals Online (AJOL)

    Performance Modelling of Steam Turbine Performance using Fuzzy Logic ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES. Journal of Applied Sciences and Environmental Management ... A Fuzzy Inference System for predicting the performance of steam turbine

  3. Developing new bacteria subroutines in the SWAT model

    Science.gov (United States)

    Fecal bacteria observations from four different sites in Korea and the US demonstrate seasonal variability, showing a significant relationship with temperature (Figure 1); fecal indicator bacteria (FIB) concentrations are relatively higher in summer and lower in winter , including Stillwater river (...

  4. Hydrological Modeling of the Upper Indus Basin: A Case Study from a High-Altitude Glacierized Catchment Hunza

    Directory of Open Access Journals (Sweden)

    Khan Garee

    2017-01-01

    Full Text Available The Soil andWater Assessment Tool (SWAT model combined with a temperature index and elevation band algorithm was applied to the Hunza watershed, where snow and glacier-melt are the major contributor to river flow. This study’s uniqueness is its use of a snow melt algorithm (temperature index with elevation bands combined with the SWAT, applied to evaluate the performance of the SWAT model in the highly snow and glacier covered watershed of the Upper Indus Basin in response to climate change on future streamflow volume at the outlet of the Hunza watershed, and its contribution to the Indus River System in both space and time, despite its limitation; it is not designed to cover the watershed of heterogeneous mountains. The model was calibrated for the years 1998–2004 and validated for the years 2008–2010. The model performance is evaluated using the four recommended statistical coefficients with uncertainty analysis (p-factor and r-factor. Simulations generated good calibration and validation results for the daily flow gauge. The model efficiency was evaluated, and a strong relationship was observed between the simulated and observed flows. The model results give a coefficient of determination (R2 of 0.82 and a Nash–Sutcliffe Efficiency index (NS of 0.80 for the daily flow with values of p-factor (79% and r-factor (76%. The SWAT model was also used to evaluate climate change impact on hydrological regimes, the target watershed with three GCMs (General Circulation Model of the IPCC fifth report for 2030–2059 and 2070–2099, using 1980–2010 as the control period. Overall, temperature (1.39 C to 6.58 C and precipitation (31% indicated increased variability at the end of the century with increasing river flow (5%–10%; in particular, the analysis showed smaller absolute changes in the hydrology of the study area towards the end of the century. The results revealed that the calibrated model was more sensitive towards temperature and

  5. Photovoltaic array performance simulation models

    Energy Technology Data Exchange (ETDEWEB)

    Menicucci, D. F.

    1986-09-15

    The experience of the solar industry confirms that, despite recent cost reductions, the profitability of photovoltaic (PV) systems is often marginal and the configuration and sizing of a system is a critical problem for the design engineer. Construction and evaluation of experimental systems are expensive and seldom justifiable. A mathematical model or computer-simulation program is a desirable alternative, provided reliable results can be obtained. Sandia National Laboratories, Albuquerque (SNLA), has been studying PV-system modeling techniques in an effort to develop an effective tool to be used by engineers and architects in the design of cost-effective PV systems. This paper reviews two of the sources of error found in previous PV modeling programs, presents the remedies developed to correct these errors, and describes a new program that incorporates these improvements.

  6. Hydrological effects of the increased CO2 and climate change in the Upper Mississippi River Basin using a modified SWAT

    Science.gov (United States)

    Wu, Y.; Liu, S.; Abdul-Aziz, O. I.

    2012-01-01

    Increased atmospheric CO2 concentration and climate change may significantly impact the hydrological and meteorological processes of a watershed system. Quantifying and understanding hydrological responses to elevated ambient CO2 and climate change is, therefore, critical for formulating adaptive strategies for an appropriate management of water resources. In this study, the Soil and Water Assessment Tool (SWAT) model was applied to assess the effects of increased CO2 concentration and climate change in the Upper Mississippi River Basin (UMRB). The standard SWAT model was modified to represent more mechanistic vegetation type specific responses of stomatal conductance reduction and leaf area increase to elevated CO2 based on physiological studies. For estimating the historical impacts of increased CO2 in the recent past decades, the incremental (i.e., dynamic) rises of CO2 concentration at a monthly time-scale were also introduced into the model. Our study results indicated that about 1–4% of the streamflow in the UMRB during 1986 through 2008 could be attributed to the elevated CO2 concentration. In addition to evaluating a range of future climate sensitivity scenarios, the climate projections by four General Circulation Models (GCMs) under different greenhouse gas emission scenarios were used to predict the hydrological effects in the late twenty-first century (2071–2100). Our simulations demonstrated that the water yield would increase in spring and substantially decrease in summer, while soil moisture would rise in spring and decline in summer. Such an uneven distribution of water with higher variability compared to the baseline level (1961–1990) may cause an increased risk of both flooding and drought events in the basin.

  7. Maintenance Personnel Performance Simulation (MAPPS) model

    International Nuclear Information System (INIS)

    Siegel, A.I.; Bartter, W.D.; Wolf, J.J.; Knee, H.E.; Haas, P.M.

    1984-01-01

    A stochastic computer model for simulating the actions and behavior of nuclear power plant maintenance personnel is described. The model considers personnel, environmental, and motivational variables to yield predictions of maintenance performance quality and time to perform. The mode has been fully developed and sensitivity tested. Additional evaluation of the model is now taking place

  8. Cognitive performance modeling based on general systems performance theory.

    Science.gov (United States)

    Kondraske, George V

    2010-01-01

    General Systems Performance Theory (GSPT) was initially motivated by problems associated with quantifying different aspects of human performance. It has proved to be invaluable for measurement development and understanding quantitative relationships between human subsystem capacities and performance in complex tasks. It is now desired to bring focus to the application of GSPT to modeling of cognitive system performance. Previous studies involving two complex tasks (i.e., driving and performing laparoscopic surgery) and incorporating measures that are clearly related to cognitive performance (information processing speed and short-term memory capacity) were revisited. A GSPT-derived method of task analysis and performance prediction termed Nonlinear Causal Resource Analysis (NCRA) was employed to determine the demand on basic cognitive performance resources required to support different levels of complex task performance. This approach is presented as a means to determine a cognitive workload profile and the subsequent computation of a single number measure of cognitive workload (CW). Computation of CW may be a viable alternative to measuring it. Various possible "more basic" performance resources that contribute to cognitive system performance are discussed. It is concluded from this preliminary exploration that a GSPT-based approach can contribute to defining cognitive performance models that are useful for both individual subjects and specific groups (e.g., military pilots).

  9. Assembly line performance and modeling

    Science.gov (United States)

    Rane, Arun B.; Sunnapwar, Vivek K.

    2017-09-01

    Automobile sector forms the backbone of manufacturing sector. Vehicle assembly line is important section in automobile plant where repetitive tasks are performed one after another at different workstations. In this thesis, a methodology is proposed to reduce cycle time and time loss due to important factors like equipment failure, shortage of inventory, absenteeism, set-up, material handling, rejection and fatigue to improve output within given cost constraints. Various relationships between these factors, corresponding cost and output are established by scientific approach. This methodology is validated in three different vehicle assembly plants. Proposed methodology may help practitioners to optimize the assembly line using lean techniques.

  10. Evapotranspiration management based on the application of SWAT for balancing water consumption: A case study in Guantao, China

    Science.gov (United States)

    Liu, Bin; Gan, Hong

    2018-06-01

    Rapid social and economic development results in increased demand for water resources. This can lead to the unsustainable development and exploitation of water resources which in turn causes significant environmental problems. Conventional water resource management approaches, such as supply and demand management strategies, frequently fail to restore regional water balance. This paper introduces the concept of water consumption balance, the balance between actual evapotranspiration (ET) and target ET, and establishes a framework to realize regional water balance. The framework consists of three stages: (1) determination of target ET and actual ET; (2) quantification of the water-saving requirements for the region; and (3) reduction of actual ET by implementing various water saving management strategies. Using this framework, a case study was conducted for Guantao County, China. The SWAT model was utilized to aid in the selection of the best water saving management strategy by comparing the ET of different irrigation methods and crop pattern adjustments. Simulation results revealed that determination of SWAT model parameters using remote sensing ET is feasible and that the model is a valuable tool for ET management. Irrigation was found to have a greater influence on the ET of winter wheat as compared to that of maize, indicating that reduction in winter wheat cultivation is the most effective way to reduce regional ET. However, the effect of water-saving irrigation methods on the reduction of ET was not obvious. This indicates that it would be difficult to achieve regional ET reduction using water-saving irrigation methods only. Furthermore, selecting the best water saving management strategy by relying solely on the amount of reduced ET was insufficient, because it ignored the impact of water conservation measures on the livelihood of the agricultural community. Incorporating these considerations with our findings, we recommend changing the current irrigation

  11. Environmental gamma radiation measurement in District Swat (Pakistan))

    International Nuclear Information System (INIS)

    Jabbar, T.; Khan, K.; Akhter, P.; Jabbar, A.; Subhani, M.S.

    2008-01-01

    External exposure to environmental gamma ray sources is an important component of exposure to the public. A survey was carried out to determine activity concentration levels and associated doses from 226 Ra, 232 Th, 40 K and 137 Cs by means of high-resolution gamma ray spectrometry in the Swat district, famous for tourism. The mean concentrations for 226 Ra, 232 Th and 40 K were found to be 50.4 ± 0.7, 34.8 ± 0.7 and 434.5 ± 7.4 Bq kg -1 , respectively, in soil samples, which are slightly more than the world average values. However, 137 Cs was only found in the soil sample of Barikot with an activity concentration of 34 ± 1.2 Bq kg -1 . Only 40 K was determined in vegetation samples with an average activity of 172.2 ± 1.7 Bq kg -1 , whereas in water samples, all radionuclides were found below lower limits of detection. The radium equivalent activity in all soil samples is lower than the limit set in the Organisation for Economic Cooperation and Development report (370 Bq kg -1 ). The value of the external exposure dose has been determined from the content of these radionuclides in soil. The average terrestrial gamma air absorbed dose rate was observed to be 62.4 nGy h -1 , which yields an annual effective dose of 0.08 mSv. The average value of the annual effective dose lies close to the global range of outdoor radiation exposure given in United Nations Scientific Committee on the Effects of Atomic Radiation. However, the main component of the radiation dose to the population residing in the study area arises from cosmic ray due to high altitude. (authors)

  12. Work domain constraints for modelling surgical performance.

    Science.gov (United States)

    Morineau, Thierry; Riffaud, Laurent; Morandi, Xavier; Villain, Jonathan; Jannin, Pierre

    2015-10-01

    Three main approaches can be identified for modelling surgical performance: a competency-based approach, a task-based approach, both largely explored in the literature, and a less known work domain-based approach. The work domain-based approach first describes the work domain properties that constrain the agent's actions and shape the performance. This paper presents a work domain-based approach for modelling performance during cervical spine surgery, based on the idea that anatomical structures delineate the surgical performance. This model was evaluated through an analysis of junior and senior surgeons' actions. Twenty-four cervical spine surgeries performed by two junior and two senior surgeons were recorded in real time by an expert surgeon. According to a work domain-based model describing an optimal progression through anatomical structures, the degree of adjustment of each surgical procedure to a statistical polynomial function was assessed. Each surgical procedure showed a significant suitability with the model and regression coefficient values around 0.9. However, the surgeries performed by senior surgeons fitted this model significantly better than those performed by junior surgeons. Analysis of the relative frequencies of actions on anatomical structures showed that some specific anatomical structures discriminate senior from junior performances. The work domain-based modelling approach can provide an overall statistical indicator of surgical performance, but in particular, it can highlight specific points of interest among anatomical structures that the surgeons dwelled on according to their level of expertise.

  13. Constrained bayesian inference of project performance models

    OpenAIRE

    Sunmola, Funlade

    2013-01-01

    Project performance models play an important role in the management of project success. When used for monitoring projects, they can offer predictive ability such as indications of possible delivery problems. Approaches for monitoring project performance relies on available project information including restrictions imposed on the project, particularly the constraints of cost, quality, scope and time. We study in this paper a Bayesian inference methodology for project performance modelling in ...

  14. Transmutation Fuel Performance Code Thermal Model Verification

    Energy Technology Data Exchange (ETDEWEB)

    Gregory K. Miller; Pavel G. Medvedev

    2007-09-01

    FRAPCON fuel performance code is being modified to be able to model performance of the nuclear fuels of interest to the Global Nuclear Energy Partnership (GNEP). The present report documents the effort for verification of the FRAPCON thermal model. It was found that, with minor modifications, FRAPCON thermal model temperature calculation agrees with that of the commercial software ABAQUS (Version 6.4-4). This report outlines the methodology of the verification, code input, and calculation results.

  15. Model performance analysis and model validation in logistic regression

    Directory of Open Access Journals (Sweden)

    Rosa Arboretti Giancristofaro

    2007-10-01

    Full Text Available In this paper a new model validation procedure for a logistic regression model is presented. At first, we illustrate a brief review of different techniques of model validation. Next, we define a number of properties required for a model to be considered "good", and a number of quantitative performance measures. Lastly, we describe a methodology for the assessment of the performance of a given model by using an example taken from a management study.

  16. High Y-chromosomal differentiation among ethnic groups of Dir and Swat districts, Pakistan

    DEFF Research Database (Denmark)

    Ullah, Inam; Olofsson, Jill K.; Margaryan, Ashot

    2017-01-01

    The ethnic groups that inhabit the mountainous Dir and Swat districts of northern Pakistan are marked by high levels of cultural and phenotypic diversity. To obtain knowledge of the extent of genetic diversity in this region, we investigated Y-chromosomal diversity in five population samples repr...

  17. Photovoltaic performance models - A report card

    Science.gov (United States)

    Smith, J. H.; Reiter, L. R.

    1985-01-01

    Models for the analysis of photovoltaic (PV) systems' designs, implementation policies, and economic performance, have proliferated while keeping pace with rapid changes in basic PV technology and extensive empirical data compiled for such systems' performance. Attention is presently given to the results of a comparative assessment of ten well documented and widely used models, which range in complexity from first-order approximations of PV system performance to in-depth, circuit-level characterizations. The comparisons were made on the basis of the performance of their subsystem, as well as system, elements. The models fall into three categories in light of their degree of aggregation into subsystems: (1) simplified models for first-order calculation of system performance, with easily met input requirements but limited capability to address more than a small variety of design considerations; (2) models simulating PV systems in greater detail, encompassing types primarily intended for either concentrator-incorporating or flat plate collector PV systems; and (3) models not specifically designed for PV system performance modeling, but applicable to aspects of electrical system design. Models ignoring subsystem failure or degradation are noted to exclude operating and maintenance characteristics as well.

  18. Performance of different radiotherapy workload models

    International Nuclear Information System (INIS)

    Barbera, Lisa; Jackson, Lynda D.; Schulze, Karleen; Groome, Patti A.; Foroudi, Farshad; Delaney, Geoff P.; Mackillop, William J.

    2003-01-01

    Purpose: The purpose of this study was to evaluate the performance of different radiotherapy workload models using a prospectively collected dataset of patient and treatment information from a single center. Methods and Materials: Information about all individual radiotherapy treatments was collected for 2 weeks from the three linear accelerators (linacs) in our department. This information included diagnosis code, treatment site, treatment unit, treatment time, fields per fraction, technique, beam type, blocks, wedges, junctions, port films, and Eastern Cooperative Oncology Group (ECOG) performance status. We evaluated the accuracy and precision of the original and revised basic treatment equivalent (BTE) model, the simple and complex Addenbrooke models, the equivalent simple treatment visit (ESTV) model, fields per hour, and two local standards of workload measurement. Results: Data were collected for 2 weeks in June 2001. During this time, 151 patients were treated with 857 fractions. The revised BTE model performed better than the other models with a mean vertical bar observed - predicted vertical bar of 2.62 (2.44-2.80). It estimated 88.0% of treatment times within 5 min, which is similar to the previously reported accuracy of the model. Conclusion: The revised BTE model had similar accuracy and precision for data collected in our center as it did for the original dataset and performed the best of the models assessed. This model would have uses for patient scheduling, and describing workloads and case complexity

  19. Iowa calibration of MEPDG performance prediction models.

    Science.gov (United States)

    2013-06-01

    This study aims to improve the accuracy of AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) pavement : performance predictions for Iowa pavement systems through local calibration of MEPDG prediction models. A total of 130 : representative p...

  20. Assessing the Efficacy of the SWAT Auto-Irrigation Function to Simulate Irrigation, Evapotranspiration, and Crop Response to Management Strategies of the Texas High Plains

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2017-07-01

    Full Text Available In the semi-arid Texas High Plains, the underlying Ogallala Aquifer is experiencing continuing decline due to long-term pumping for irrigation with limited recharge. Accurate simulation of irrigation and other associated water balance components are critical for meaningful evaluation of the effects of irrigation management strategies. Modelers often employ auto-irrigation functions within models such as the Soil and Water Assessment Tool (SWAT. However, some studies have raised concerns as to whether the function is able to adequately simulate representative irrigation practices. In this study, observations of climate, irrigation, evapotranspiration (ET, leaf area index (LAI, and crop yield derived from an irrigated lysimeter field at the USDA-ARS Conservation and Production Research Laboratory at Bushland, Texas were used to evaluate the efficacy of the SWAT auto-irrigation functions. Results indicated good agreement between simulated and observed daily ET during both model calibration (2001–2005 and validation (2006–2010 periods for the baseline scenario (Nash-Sutcliffe efficiency; NSE ≥ 0.80. The auto-irrigation scenarios resulted in reasonable ET simulations under all the thresholds of soil water deficit (SWD triggers as indicated by NSE values > 0.5. However, the auto-irrigation function did not adequately represent field practices, due to the continuation of irrigation after crop maturity and excessive irrigation when SWD triggers were less than the static irrigation amount.

  1. Cost and Performance Model for Photovoltaic Systems

    Science.gov (United States)

    Borden, C. S.; Smith, J. H.; Davisson, M. C.; Reiter, L. J.

    1986-01-01

    Lifetime cost and performance (LCP) model assists in assessment of design options for photovoltaic systems. LCP is simulation of performance, cost, and revenue streams associated with photovoltaic power systems connected to electric-utility grid. LCP provides user with substantial flexibility in specifying technical and economic environment of application.

  2. Assessing Ecosystem Model Performance in Semiarid Systems

    Science.gov (United States)

    Thomas, A.; Dietze, M.; Scott, R. L.; Biederman, J. A.

    2017-12-01

    In ecosystem process modelling, comparing outputs to benchmark datasets observed in the field is an important way to validate models, allowing the modelling community to track model performance over time and compare models at specific sites. Multi-model comparison projects as well as models themselves have largely been focused on temperate forests and similar biomes. Semiarid regions, on the other hand, are underrepresented in land surface and ecosystem modelling efforts, and yet will be disproportionately impacted by disturbances such as climate change due to their sensitivity to changes in the water balance. Benchmarking models at semiarid sites is an important step in assessing and improving models' suitability for predicting the impact of disturbance on semiarid ecosystems. In this study, several ecosystem models were compared at a semiarid grassland in southwestern Arizona using PEcAn, or the Predictive Ecosystem Analyzer, an open-source eco-informatics toolbox ideal for creating the repeatable model workflows necessary for benchmarking. Models included SIPNET, DALEC, JULES, ED2, GDAY, LPJ-GUESS, MAESPA, CLM, CABLE, and FATES. Comparison between model output and benchmarks such as net ecosystem exchange (NEE) tended to produce high root mean square error and low correlation coefficients, reflecting poor simulation of seasonality and the tendency for models to create much higher carbon sources than observed. These results indicate that ecosystem models do not currently adequately represent semiarid ecosystem processes.

  3. Driver Performance Model: 1. Conceptual Framework

    National Research Council Canada - National Science Library

    Heimerl, Joseph

    2001-01-01

    ...'. At the present time, no such comprehensive model exists. This report discusses a conceptual framework designed to encompass the relationships, conditions, and constraints related to direct, indirect, and remote modes of driving and thus provides a guide or 'road map' for the construction and creation of a comprehensive driver performance model.

  4. Performance engineering in the community atmosphere model

    International Nuclear Information System (INIS)

    Worley, P; Mirin, A; Drake, J; Sawyer, W

    2006-01-01

    The Community Atmosphere Model (CAM) is the atmospheric component of the Community Climate System Model (CCSM) and is the primary consumer of computer resources in typical CCSM simulations. Performance engineering has been an important aspect of CAM development throughout its existence. This paper briefly summarizes these efforts and their impacts over the past five years

  5. Performance of hedging strategies in interval models

    NARCIS (Netherlands)

    Roorda, Berend; Engwerda, Jacob; Schumacher, J.M.

    2005-01-01

    For a proper assessment of risks associated with the trading of derivatives, the performance of hedging strategies should be evaluated not only in the context of the idealized model that has served as the basis of strategy development, but also in the context of other models. In this paper we

  6. Performability assessment by model checking of Markov reward models

    NARCIS (Netherlands)

    Baier, Christel; Cloth, L.; Haverkort, Boudewijn R.H.M.; Hermanns, H.; Katoen, Joost P.

    2010-01-01

    This paper describes efficient procedures for model checking Markov reward models, that allow us to evaluate, among others, the performability of computer-communication systems. We present the logic CSRL (Continuous Stochastic Reward Logic) to specify performability measures. It provides flexibility

  7. Analysing the temporal dynamics of model performance for hydrological models

    NARCIS (Netherlands)

    Reusser, D.E.; Blume, T.; Schaefli, B.; Zehe, E.

    2009-01-01

    The temporal dynamics of hydrological model performance gives insights into errors that cannot be obtained from global performance measures assigning a single number to the fit of a simulated time series to an observed reference series. These errors can include errors in data, model parameters, or

  8. Analytical performance modeling for computer systems

    CERN Document Server

    Tay, Y C

    2013-01-01

    This book is an introduction to analytical performance modeling for computer systems, i.e., writing equations to describe their performance behavior. It is accessible to readers who have taken college-level courses in calculus and probability, networking and operating systems. This is not a training manual for becoming an expert performance analyst. Rather, the objective is to help the reader construct simple models for analyzing and understanding the systems that they are interested in.Describing a complicated system abstractly with mathematical equations requires a careful choice of assumpti

  9. Performance modeling, loss networks, and statistical multiplexing

    CERN Document Server

    Mazumdar, Ravi

    2009-01-01

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of understanding the phenomenon of statistical multiplexing. The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the important ideas of Palm distributions associated with traffic models and their role in performance measures. Also presented are recent ideas of large buffer, and many sources asymptotics that play an important role in understanding statistical multiplexing. I

  10. Shock circle model for ejector performance evaluation

    International Nuclear Information System (INIS)

    Zhu, Yinhai; Cai, Wenjian; Wen, Changyun; Li, Yanzhong

    2007-01-01

    In this paper, a novel shock circle model for the prediction of ejector performance at the critical mode operation is proposed. By introducing the 'shock circle' at the entrance of the constant area chamber, a 2D exponential expression for velocity distribution is adopted to approximate the viscosity flow near the ejector inner wall. The advantage of the 'shock circle' analysis is that the calculation of ejector performance is independent of the flows in the constant area chamber and diffuser. Consequently, the calculation is even simpler than many 1D modeling methods and can predict the performance of critical mode operation ejectors much more accurately. The effectiveness of the method is validated by two experimental results reported earlier. The proposed modeling method using two coefficients is shown to produce entrainment ratio, efficiency and coefficient of performance (COP) accurately and much closer to experimental results than those of 1D analysis methods

  11. Advances in HTGR fuel performance models

    International Nuclear Information System (INIS)

    Stansfield, O.M.; Goodin, D.T.; Hanson, D.L.; Turner, R.F.

    1985-01-01

    Advances in HTGR fuel performance models have improved the agreement between observed and predicted performance and contributed to an enhanced position of the HTGR with regard to investment risk and passive safety. Heavy metal contamination is the source of about 55% of the circulating activity in the HTGR during normal operation, and the remainder comes primarily from particles which failed because of defective or missing buffer coatings. These failed particles make up about 5 x 10 -4 fraction of the total core inventory. In addition to prediction of fuel performance during normal operation, the models are used to determine fuel failure and fission product release during core heat-up accident conditions. The mechanistic nature of the models, which incorporate all important failure modes, permits the prediction of performance from the relatively modest accident temperatures of a passively safe HTGR to the much more severe accident conditions of the larger 2240-MW/t HTGR. (author)

  12. Performance Evaluation Model for Application Layer Firewalls.

    Science.gov (United States)

    Xuan, Shichang; Yang, Wu; Dong, Hui; Zhang, Jiangchuan

    2016-01-01

    Application layer firewalls protect the trusted area network against information security risks. However, firewall performance may affect user experience. Therefore, performance analysis plays a significant role in the evaluation of application layer firewalls. This paper presents an analytic model of the application layer firewall, based on a system analysis to evaluate the capability of the firewall. In order to enable users to improve the performance of the application layer firewall with limited resources, resource allocation was evaluated to obtain the optimal resource allocation scheme in terms of throughput, delay, and packet loss rate. The proposed model employs the Erlangian queuing model to analyze the performance parameters of the system with regard to the three layers (network, transport, and application layers). Then, the analysis results of all the layers are combined to obtain the overall system performance indicators. A discrete event simulation method was used to evaluate the proposed model. Finally, limited service desk resources were allocated to obtain the values of the performance indicators under different resource allocation scenarios in order to determine the optimal allocation scheme. Under limited resource allocation, this scheme enables users to maximize the performance of the application layer firewall.

  13. Performance Evaluation Model for Application Layer Firewalls.

    Directory of Open Access Journals (Sweden)

    Shichang Xuan

    Full Text Available Application layer firewalls protect the trusted area network against information security risks. However, firewall performance may affect user experience. Therefore, performance analysis plays a significant role in the evaluation of application layer firewalls. This paper presents an analytic model of the application layer firewall, based on a system analysis to evaluate the capability of the firewall. In order to enable users to improve the performance of the application layer firewall with limited resources, resource allocation was evaluated to obtain the optimal resource allocation scheme in terms of throughput, delay, and packet loss rate. The proposed model employs the Erlangian queuing model to analyze the performance parameters of the system with regard to the three layers (network, transport, and application layers. Then, the analysis results of all the layers are combined to obtain the overall system performance indicators. A discrete event simulation method was used to evaluate the proposed model. Finally, limited service desk resources were allocated to obtain the values of the performance indicators under different resource allocation scenarios in order to determine the optimal allocation scheme. Under limited resource allocation, this scheme enables users to maximize the performance of the application layer firewall.

  14. Tailored model abstraction in performance assessments

    International Nuclear Information System (INIS)

    Kessler, J.H.

    1995-01-01

    Total System Performance Assessments (TSPAs) are likely to be one of the most significant parts of making safety cases for the continued development and licensing of geologic repositories for the disposal of spent fuel and HLW. Thus, it is critical that the TSPA model capture the 'essence' of the physical processes relevant to demonstrating the appropriate regulation is met. But how much detail about the physical processes must be modeled and understood before there is enough confidence that the appropriate essence has been captured? In this summary the level of model abstraction that is required is discussed. Approaches for subsystem and total system performance analyses are outlined, and the role of best estimate models is examined. It is concluded that a conservative approach for repository performance, based on limited amount of field and laboratory data, can provide sufficient confidence for a regulatory decision

  15. Model analysis of check dam impacts on long-term sediment and water budgets in southeast Arizona, USA

    Science.gov (United States)

    Norman, Laura M.; Niraula, Rewati

    2016-01-01

    The objective of this study was to evaluate the effect of check dam infrastructure on soil and water conservation at the catchment scale using the Soil and Water Assessment Tool (SWAT). This paired watershed study includes a watershed treated with over 2000 check dams and a Control watershed which has none, in the West Turkey Creek watershed, Southeast Arizona, USA. SWAT was calibrated for streamflow using discharge documented during the summer of 2013 at the Control site. Model results depict the necessity to eliminate lateral flow from SWAT models of aridland environments, the urgency to standardize geospatial soils data, and the care for which modelers must document altering parameters when presenting findings. Performance was assessed using the percent bias (PBIAS), with values of ±2.34%. The calibrated model was then used to examine the impacts of check dams at the Treated watershed. Approximately 630 tons of sediment is estimated to be stored behind check dams in the Treated watershed over the 3-year simulation, increasing water quality for fish habitat. A minimum precipitation event of 15 mm was necessary to instigate the detachment of soil, sediments, or rock from the study area, which occurred 2% of the time. The resulting watershed model is useful as a predictive framework and decision-support tool to consider long-term impacts of restoration and potential for future restoration.

  16. Critical review of glass performance modeling

    International Nuclear Information System (INIS)

    Bourcier, W.L.

    1994-07-01

    Borosilicate glass is to be used for permanent disposal of high-level nuclear waste in a geologic repository. Mechanistic chemical models are used to predict the rate at which radionuclides will be released from the glass under repository conditions. The most successful and useful of these models link reaction path geochemical modeling programs with a glass dissolution rate law that is consistent with transition state theory. These models have been used to simulate several types of short-term laboratory tests of glass dissolution and to predict the long-term performance of the glass in a repository. Although mechanistically based, the current models are limited by a lack of unambiguous experimental support for some of their assumptions. The most severe problem of this type is the lack of an existing validated mechanism that controls long-term glass dissolution rates. Current models can be improved by performing carefully designed experiments and using the experimental results to validate the rate-controlling mechanisms implicit in the models. These models should be supported with long-term experiments to be used for model validation. The mechanistic basis of the models should be explored by using modern molecular simulations such as molecular orbital and molecular dynamics to investigate both the glass structure and its dissolution process

  17. Critical review of glass performance modeling

    Energy Technology Data Exchange (ETDEWEB)

    Bourcier, W.L. [Lawrence Livermore National Lab., CA (United States)

    1994-07-01

    Borosilicate glass is to be used for permanent disposal of high-level nuclear waste in a geologic repository. Mechanistic chemical models are used to predict the rate at which radionuclides will be released from the glass under repository conditions. The most successful and useful of these models link reaction path geochemical modeling programs with a glass dissolution rate law that is consistent with transition state theory. These models have been used to simulate several types of short-term laboratory tests of glass dissolution and to predict the long-term performance of the glass in a repository. Although mechanistically based, the current models are limited by a lack of unambiguous experimental support for some of their assumptions. The most severe problem of this type is the lack of an existing validated mechanism that controls long-term glass dissolution rates. Current models can be improved by performing carefully designed experiments and using the experimental results to validate the rate-controlling mechanisms implicit in the models. These models should be supported with long-term experiments to be used for model validation. The mechanistic basis of the models should be explored by using modern molecular simulations such as molecular orbital and molecular dynamics to investigate both the glass structure and its dissolution process.

  18. Performance modeling, stochastic networks, and statistical multiplexing

    CERN Document Server

    Mazumdar, Ravi R

    2013-01-01

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of introducing an appropriate mathematical framework for modeling and analysis as well as understanding the phenomenon of statistical multiplexing. The models, techniques, and results presented form the core of traffic engineering methods used to design, control and allocate resources in communication networks.The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the importan

  19. A statistical model for predicting muscle performance

    Science.gov (United States)

    Byerly, Diane Leslie De Caix

    The objective of these studies was to develop a capability for predicting muscle performance and fatigue to be utilized for both space- and ground-based applications. To develop this predictive model, healthy test subjects performed a defined, repetitive dynamic exercise to failure using a Lordex spinal machine. Throughout the exercise, surface electromyography (SEMG) data were collected from the erector spinae using a Mega Electronics ME3000 muscle tester and surface electrodes placed on both sides of the back muscle. These data were analyzed using a 5th order Autoregressive (AR) model and statistical regression analysis. It was determined that an AR derived parameter, the mean average magnitude of AR poles, significantly correlated with the maximum number of repetitions (designated Rmax) that a test subject was able to perform. Using the mean average magnitude of AR poles, a test subject's performance to failure could be predicted as early as the sixth repetition of the exercise. This predictive model has the potential to provide a basis for improving post-space flight recovery, monitoring muscle atrophy in astronauts and assessing the effectiveness of countermeasures, monitoring astronaut performance and fatigue during Extravehicular Activity (EVA) operations, providing pre-flight assessment of the ability of an EVA crewmember to perform a given task, improving the design of training protocols and simulations for strenuous International Space Station assembly EVA, and enabling EVA work task sequences to be planned enhancing astronaut performance and safety. Potential ground-based, medical applications of the predictive model include monitoring muscle deterioration and performance resulting from illness, establishing safety guidelines in the industry for repetitive tasks, monitoring the stages of rehabilitation for muscle-related injuries sustained in sports and accidents, and enhancing athletic performance through improved training protocols while reducing

  20. Species Distribution Modelling of Aedes aegypti in two dengue-endemic regions of Pakistan.

    Science.gov (United States)

    Fatima, Syeda Hira; Atif, Salman; Rasheed, Syed Basit; Zaidi, Farrah; Hussain, Ejaz

    2016-03-01

    Statistical tools are effectively used to determine the distribution of mosquitoes and to make ecological inferences about the vector-borne disease dynamics. In this study, we utilised species distribution models to understand spatial patterns of Aedes aegypti in two dengue-prevalent regions of Pakistan, Lahore and Swat. Species distribution models can potentially indicate the probability of suitability of Ae. aegypti once introduced to new regions like Swat, where invasion of this species is a recent phenomenon. The distribution of Ae. aegypti was determined by applying the MaxEnt algorithm on a set of potential environmental factors and species sample records. The ecological dependency of species on each environmental variable was analysed using response curves. We quantified the statistical performance of the models based on accuracy assessment and spatial predictions. Our results suggest that Ae. aegypti is widely distributed in Lahore. Human population density and urban infrastructure are primarily responsible for greater probability of mosquito occurrence in this region. In Swat, Ae. aegypti has clumped distribution, where urban patches provide refuge to the species in an otherwise hostile heterogeneous environment and road networks are assumed to have facilitated in passive-mediated dispersal of species. In Pakistan, Ae. aegypti is expanding its range northwards; this could be associated with rapid urbanisation, trade and travel. The main implication of this expansion is that more people are at risk of dengue fever in the northern highlands of Pakistan. © 2016 John Wiley & Sons Ltd.

  1. Wave and Wind Model Performance Metrics Tools

    Science.gov (United States)

    Choi, J. K.; Wang, D. W.

    2016-02-01

    Continual improvements and upgrades of Navy ocean wave and wind models are essential to the assurance of battlespace environment predictability of ocean surface wave and surf conditions in support of Naval global operations. Thus, constant verification and validation of model performance is equally essential to assure the progress of model developments and maintain confidence in the predictions. Global and regional scale model evaluations may require large areas and long periods of time. For observational data to compare against, altimeter winds and waves along the tracks from past and current operational satellites as well as moored/drifting buoys can be used for global and regional coverage. Using data and model runs in previous trials such as the planned experiment, the Dynamics of the Adriatic in Real Time (DART), we demonstrated the use of accumulated altimeter wind and wave data over several years to obtain an objective evaluation of the performance the SWAN (Simulating Waves Nearshore) model running in the Adriatic Sea. The assessment provided detailed performance of wind and wave models by using cell-averaged statistical variables maps with spatial statistics including slope, correlation, and scatter index to summarize model performance. Such a methodology is easily generalized to other regions and at global scales. Operational technology currently used by subject matter experts evaluating the Navy Coastal Ocean Model and the Hybrid Coordinate Ocean Model can be expanded to evaluate wave and wind models using tools developed for ArcMAP, a GIS application developed by ESRI. Recent inclusion of altimeter and buoy data into a format through the Naval Oceanographic Office's (NAVOCEANO) quality control system and the netCDF standards applicable to all model output makes it possible for the fusion of these data and direct model verification. Also, procedures were developed for the accumulation of match-ups of modelled and observed parameters to form a data base

  2. Generating Performance Models for Irregular Applications

    Energy Technology Data Exchange (ETDEWEB)

    Friese, Ryan D.; Tallent, Nathan R.; Vishnu, Abhinav; Kerbyson, Darren J.; Hoisie, Adolfy

    2017-05-30

    Many applications have irregular behavior --- non-uniform input data, input-dependent solvers, irregular memory accesses, unbiased branches --- that cannot be captured using today's automated performance modeling techniques. We describe new hierarchical critical path analyses for the \\Palm model generation tool. To create a model's structure, we capture tasks along representative MPI critical paths. We create a histogram of critical tasks with parameterized task arguments and instance counts. To model each task, we identify hot instruction-level sub-paths and model each sub-path based on data flow, instruction scheduling, and data locality. We describe application models that generate accurate predictions for strong scaling when varying CPU speed, cache speed, memory speed, and architecture. We present results for the Sweep3D neutron transport benchmark; Page Rank on multiple graphs; Support Vector Machine with pruning; and PFLOTRAN's reactive flow/transport solver with domain-induced load imbalance.

  3. Measurement-based reliability/performability models

    Science.gov (United States)

    Hsueh, Mei-Chen

    1987-01-01

    Measurement-based models based on real error-data collected on a multiprocessor system are described. Model development from the raw error-data to the estimation of cumulative reward is also described. A workload/reliability model is developed based on low-level error and resource usage data collected on an IBM 3081 system during its normal operation in order to evaluate the resource usage/error/recovery process in a large mainframe system. Thus, both normal and erroneous behavior of the system are modeled. The results provide an understanding of the different types of errors and recovery processes. The measured data show that the holding times in key operational and error states are not simple exponentials and that a semi-Markov process is necessary to model the system behavior. A sensitivity analysis is performed to investigate the significance of using a semi-Markov process, as opposed to a Markov process, to model the measured system.

  4. Performance Measurement Model A TarBase model with ...

    Indian Academy of Sciences (India)

    rohit

    Model A 8.0 2.0 94.52% 88.46% 76 108 12 12 0.86 0.91 0.78 0.94. Model B 2.0 2.0 93.18% 89.33% 64 95 10 9 0.88 0.90 0.75 0.98. The above results for TEST – 1 show details for our two models (Model A and Model B).Performance of Model A after adding of 32 negative dataset of MiRTif on our testing set(MiRecords) ...

  5. A Procurement Performance Model for Construction Frameworks

    Directory of Open Access Journals (Sweden)

    Terence Y M Lam

    2015-07-01

    Full Text Available Collaborative construction frameworks have been developed in the United Kingdom (UK to create longer term relationships between clients and suppliers in order to improve project outcomes. Research undertaken into highways maintenance set within a major county council has confirmed that such collaborative procurement methods can improve time, cost and quality of construction projects. Building upon this and examining the same single case, this research aims to develop a performance model through identification of performance drivers in the whole project delivery process including pre and post contract phases. A priori performance model based on operational and sociological constructs was proposed and then checked by a pilot study. Factor analysis and central tendency statistics from the questionnaires as well as content analysis from the interview transcripts were conducted. It was confirmed that long term relationships, financial and non-financial incentives and stronger communication are the sociological behaviour factors driving performance. The interviews also established that key performance indicators (KPIs can be used as an operational measure to improve performance. With the posteriori performance model, client project managers can effectively collaboratively manage contractor performance through procurement measures including use of longer term and KPIs for the contract so that the expected project outcomes can be achieved. The findings also make significant contribution to construction framework procurement theory by identifying the interrelated sociological and operational performance drivers. This study is set predominantly in the field of highways civil engineering. It is suggested that building based projects or other projects that share characteristics are grouped together and used for further research of the phenomena discovered.

  6. Models for Automated Tube Performance Calculations

    International Nuclear Information System (INIS)

    Brunkhorst, C.

    2002-01-01

    High power radio-frequency systems, as typically used in fusion research devices, utilize vacuum tubes. Evaluation of vacuum tube performance involves data taken from tube operating curves. The acquisition of data from such graphical sources is a tedious process. A simple modeling method is presented that will provide values of tube currents for a given set of element voltages. These models may be used as subroutines in iterative solutions of amplifier operating conditions for a specific loading impedance

  7. Semantic Web applications and tools for the life sciences: SWAT4LS 2010.

    Science.gov (United States)

    Burger, Albert; Paschke, Adrian; Romano, Paolo; Marshall, M Scott; Splendiani, Andrea

    2012-01-25

    As Semantic Web technologies mature and new releases of key elements, such as SPARQL 1.1 and OWL 2.0, become available, the Life Sciences continue to push the boundaries of these technologies with ever more sophisticated tools and applications. Unsurprisingly, therefore, interest in the SWAT4LS (Semantic Web Applications and Tools for the Life Sciences) activities have remained high, as was evident during the third international SWAT4LS workshop held in Berlin in December 2010. Contributors to this workshop were invited to submit extended versions of their papers, the best of which are now made available in the special supplement of BMC Bioinformatics. The papers reflect the wide range of work in this area, covering the storage and querying of Life Sciences data in RDF triple stores, tools for the development of biomedical ontologies and the semantics-based integration of Life Sciences as well as clinicial data.

  8. Performance Evaluation and Modelling of Container Terminals

    Science.gov (United States)

    Venkatasubbaiah, K.; Rao, K. Narayana; Rao, M. Malleswara; Challa, Suresh

    2018-02-01

    The present paper evaluates and analyzes the performance of 28 container terminals of south East Asia through data envelopment analysis (DEA), principal component analysis (PCA) and hybrid method of DEA-PCA. DEA technique is utilized to identify efficient decision making unit (DMU)s and to rank DMUs in a peer appraisal mode. PCA is a multivariate statistical method to evaluate the performance of container terminals. In hybrid method, DEA is integrated with PCA to arrive the ranking of container terminals. Based on the composite ranking, performance modelling and optimization of container terminals is carried out through response surface methodology (RSM).

  9. SWAT-MODSIM-PSO optimization of multi-crop planning in the Karkheh River Basin, Iran, under the impacts of climate change.

    Science.gov (United States)

    Fereidoon, Majid; Koch, Manfred

    2018-07-15

    Agriculture is one of the environmental/economic sectors that may adversely be affected by climate change, especially, in already nowadays water-scarce regions, like the Middle East. One way to cope with future changes in absolute as well as seasonal (irrigation) water amounts can be the adaptation of the agricultural crop pattern in a region, i.e. by planting crops which still provide high yields and so economic benefits to farmers under such varying climate conditions. To do this properly, the whole cascade starting from climate change, effects on hydrology and surface water availability, subsequent effects on crop yield, agricultural areas available, and, finally, economic value of a multi-crop cultivation pattern must be known. To that avail, a complex coupled simulation-optimization tool SWAT-LINGO-MODSIM-PSO (SLMP) has been developed here and used to find the future optimum cultivation area of crops for the maximization of the economic benefits in five irrigation-fed agricultural plains in the south of the Karkheh River Basin (KRB) southwest Iran. Starting with the SWAT distributed hydrological model, the KR-streamflow as well as the inflow into the Karkheh-reservoir, as the major storage of irrigation water, is calibrated and validated, based on 1985-2004 observed discharge data. In the subsequent step, the SWAT-predicted streamflow is fed into the MODSIM river basin Decision Support System to simulate and optimize the water allocation between different water users (agricultural, environmental, municipal and industrial) under standard operating policy (SOP) rules. The final step is the maximization of the economic benefit in the five agricultural plains through constrained PSO (particle swarm optimization) by adjusting the cultivation areas (decision variables) of different crops (wheat, barley, maize and "others"), taking into account their specific prizes and optimal crop yields under water deficiency, with the latter computed in the LINGO

  10. Experiences on removal of sodium-water reaction products in SWAT-3

    International Nuclear Information System (INIS)

    Tanabe, H.; Hiroi, H.; Sato, M.; Otaka, J.

    2002-01-01

    This report summarizes experiences and information concerning the removal of sodium water reaction products (SMRP) obtained through large leak tests of the Steam Generator Safety Test Facility (SWAT-3) at PNC/OEC, which were conducted to validate the safety design of steam generators of a prototype LMFBR Monju. The following three problems are discussed here: (1) drainability of SWRP, (2) removal of SWRP by using a cold trap, and (3) steam cleaning of SWRP. (author)

  11. Utilities for high performance dispersion model PHYSIC

    International Nuclear Information System (INIS)

    Yamazawa, Hiromi

    1992-09-01

    The description and usage of the utilities for the dispersion calculation model PHYSIC were summarized. The model was developed in the study of developing high performance SPEEDI with the purpose of introducing meteorological forecast function into the environmental emergency response system. The procedure of PHYSIC calculation consists of three steps; preparation of relevant files, creation and submission of JCL, and graphic output of results. A user can carry out the above procedure with the help of the Geographical Data Processing Utility, the Model Control Utility, and the Graphic Output Utility. (author)

  12. A practical model for sustainable operational performance

    International Nuclear Information System (INIS)

    Vlek, C.A.J.; Steg, E.M.; Feenstra, D.; Gerbens-Leenis, W.; Lindenberg, S.; Moll, H.; Schoot Uiterkamp, A.; Sijtsma, F.; Van Witteloostuijn, A.

    2002-01-01

    By means of a concrete model for sustainable operational performance enterprises can report uniformly on the sustainability of their contributions to the economy, welfare and the environment. The development and design of a three-dimensional monitoring system is presented and discussed [nl

  13. Data Model Performance in Data Warehousing

    Science.gov (United States)

    Rorimpandey, G. C.; Sangkop, F. I.; Rantung, V. P.; Zwart, J. P.; Liando, O. E. S.; Mewengkang, A.

    2018-02-01

    Data Warehouses have increasingly become important in organizations that have large amount of data. It is not a product but a part of a solution for the decision support system in those organizations. Data model is the starting point for designing and developing of data warehouses architectures. Thus, the data model needs stable interfaces and consistent for a longer period of time. The aim of this research is to know which data model in data warehousing has the best performance. The research method is descriptive analysis, which has 3 main tasks, such as data collection and organization, analysis of data and interpretation of data. The result of this research is discussed in a statistic analysis method, represents that there is no statistical difference among data models used in data warehousing. The organization can utilize four data model proposed when designing and developing data warehouse.

  14. Performance model for a CCTV-MTI

    International Nuclear Information System (INIS)

    Dunn, D.R.; Dunbar, D.L.

    1978-01-01

    CCTV-MTI (closed circuit television--moving target indicator) monitors represent typical components of access control systems, as for example in a material control and accounting (MC and A) safeguards system. This report describes a performance model for a CCTV-MTI monitor. The performance of a human in an MTI role is a separate problem and is not addressed here. This work was done in conjunction with the NRC sponsored LLL assessment procedure for MC and A systems which is presently under development. We develop a noise model for a generic camera system and a model for the detection mechanism for a postulated MTI design. These models are then translated into an overall performance model. Measures of performance are probabilities of detection and false alarm as a function of intruder-induced grey level changes in the protected area. Sensor responsivity, lens F-number, source illumination and spectral response were treated as design parameters. Some specific results are illustrated for a postulated design employing a camera with a Si-target vidicon. Reflectance or light level changes in excess of 10% due to an intruder will be detected with a very high probability for the portion of the visible spectrum with wavelengths above 500 nm. The resulting false alarm rate was less than one per year. We did not address sources of nuisance alarms due to adverse environments, reliability, resistance to tampering, nor did we examine the effects of the spatial frequency response of the optics. All of these are important and will influence overall system detection performance

  15. Calibration of a Distributed Hydrological Model using Remote Sensing Evapotranspiration data in the Semi-Arid Punjab Region of Pakista

    Science.gov (United States)

    Becker, R.; Usman, M.

    2017-12-01

    A SWAT (Soil Water Assessment Tool) model is applied in the semi-arid Punjab region in Pakistan. The physically based hydrological model is set up to simulate hydrological processes and water resources demands under future land use, climate change and irrigation management scenarios. In order to successfully run the model, detailed focus is laid on the calibration procedure of the model. The study deals with the following calibration issues:i. lack of reliable calibration/validation data, ii. difficulty to accurately model a highly managed system with a physically based hydrological model and iii. use of alternative and spatially distributed data sets for model calibration. In our study area field observations are rare and the entirely human controlled irrigation system renders central calibration parameters (e.g. runoff/curve number) unsuitable, as it can't be assumed that they represent the natural behavior of the hydrological system. From evapotranspiration (ET) however principal hydrological processes can still be inferred. Usman et al. (2015) derived satellite based monthly ET data for our study area based on SEBAL (Surface Energy Balance Algorithm) and created a reliable ET data set which we use in this study to calibrate our SWAT model. The initial SWAT model performance is evaluated with respect to the SEBAL results using correlation coefficients, RMSE, Nash-Sutcliffe efficiencies and mean differences. Particular focus is laid on the spatial patters, investigating the potential of a spatially differentiated parameterization instead of just using spatially uniform calibration data. A sensitivity analysis reveals the most sensitive parameters with respect to changes in ET, which are then selected for the calibration process.Using the SEBAL-ET product we calibrate the SWAT model for the time period 2005-2006 using a dynamically dimensioned global search algorithm to minimize RMSE. The model improvement after the calibration procedure is finally evaluated based

  16. Assessing The Performance of Hydrological Models

    Science.gov (United States)

    van der Knijff, Johan

    The performance of hydrological models is often characterized using the coefficient of efficiency, E. The sensitivity of E to extreme streamflow values, and the difficulty of deciding what value of E should be used as a threshold to identify 'good' models or model parameterizations, have proven to be serious shortcomings of this index. This paper reviews some alternative performance indices that have appeared in the litera- ture. Legates and McCabe (1999) suggested a more generalized form of E, E'(j,B). Here, j is a parameter that controls how much emphasis is put on extreme streamflow values, and B defines a benchmark or 'null hypothesis' against which the results of the model are tested. E'(j,B) was used to evaluate a large number of parameterizations of a conceptual rainfall-runoff model, using 6 different combinations of j and B. First, the effect of j and B is explained. Second, it is demonstrated how the index can be used to explicitly test hypotheses about the model and the data. This approach appears to be particularly attractive if the index is used as a likelihood measure within a GLUE-type analysis.

  17. System Advisor Model: Flat Plate Photovoltaic Performance Modeling Validation Report

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Janine [National Renewable Energy Lab. (NREL), Golden, CO (United States); Whitmore, Jonathan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kaffine, Leah [National Renewable Energy Lab. (NREL), Golden, CO (United States); Blair, Nate [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dobos, Aron P. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-12-01

    The System Advisor Model (SAM) is a free software tool that performs detailed analysis of both system performance and system financing for a variety of renewable energy technologies. This report provides detailed validation of the SAM flat plate photovoltaic performance model by comparing SAM-modeled PV system generation data to actual measured production data for nine PV systems ranging from 75 kW to greater than 25 MW in size. The results show strong agreement between SAM predictions and field data, with annualized prediction error below 3% for all fixed tilt cases and below 8% for all one axis tracked cases. The analysis concludes that snow cover and system outages are the primary sources of disagreement, and other deviations resulting from seasonal biases in the irradiation models and one axis tracking issues are discussed in detail.

  18. Assessment of future climate change impacts on nonpoint source pollution in snowmelt period for a cold area using SWAT.

    Science.gov (United States)

    Wang, Yu; Bian, Jianmin; Zhao, Yongsheng; Tang, Jie; Jia, Zhuo

    2018-02-05

    The source area of Liao River is a typical cold region in northeastern China, which experiences serious problems with agricultural nonpoint source pollution (NPS), it is important to understand future climate change impacts on NPS in the watershed. This issue has been investigated by coupling semi distributed hydrological model (SWAT), statistical downscaling model (SDSM) and global circulation model (GCMs). The results show that annual average temperature would rise by 2.1 °C (1.3 °C) in the 2080 s under scenario RCP8.5 (RCP4.5), and annual precipitation would increase by 67 mm (33 mm). The change in winter temperature and precipitation is most significant with an increase by 0.23 °C/10a (0.17 °C/10a) and 1.94 mm/10a (2.78 mm/10a). The future streamflow, TN and TP loads would decrease by 19.05% (10.59%), 12.27% (8.81%) and 10.63% (6.11%), respectively. Monthly average streamflow, TN and TP loads would decrease from March to November, and increase from December to February. This is because the increased precipitation and temperature in winter, which made the spring snowpack melting earlier. These study indicate the trends of nonpoint source pollution during the snowmelt period under climate change conditions, accordingly adaptation measures will be necessary.

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

    Directory of Open Access Journals (Sweden)

    M. Wang

    2015-05-01

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

  20. Potensi bambu swat (gigantochloa verticillata sebagai material karbon aktif untuk adsorbed natural gas (ANG

    Directory of Open Access Journals (Sweden)

    Dewa Ngakan Ketut Putra Negara

    2017-03-01

    Full Text Available Abstrak: Bambu merupakan material biomassa yang banyak diteliti, diproduksi sebagai karbon aktif dan diaplikasikan di berbagaibidang kehidupan. Namun sangat sedikit bahkan hampir tidak ditemukan referensi yang membahas kegunaan karbonaktif dari bambusebagai adsorbent untuk Adsorbed Natural Gas (ANG. Penelitian ini difokuskan untukmengkarakterisasai dan menevaluasi potensi bambu swat (Gigantochloa verticillata sebagai material dasar karbon aktifuntuk aplikasi ANG. Pengujian yang dilakukan meliputi uji proximate, uji ultimate, uji komposisi kimia dan pengamatanstruktur mikro. Hasil penelitian menunjukkan bahwa bambuswat memiliki kandungan lignin 22,9920%, selulosa44,2247%, volatile 88’32%, carbon 43,42%,ash 1,83%, silica (1,8664% dan nitrogen 1,7065%. Bambu swat memilikiikatan pembuluh yang terdiri atas satu ikatan pembuluh (xilem dan floem dan dua ikatan serat yang terletak di sebelahdalam dan luar dari ikatan pembuluh.Secara umum dapat dikatakan bahwa bamboo jenis ini memiliki kandungansellulosa, volatile dan karbon yang cukup tinggi serta ash, silica, hydrogen dan nitrogen yang rendah sehinggabambuswat sangat berpotensi digunakan sebagai material sumber karbon aktif.Kata kunci: Karbon aktif, bambu swat, ANG, lignin, sellulosa, analisa ultimate dan proximates Abstract: Bamboo is a biomass material widely researched, produced as activated carbon and applied in various life fields.However, very little or almost no references were found with regard to utilization of bamboo activated carbon asadsorbent for Adsorbed Natural Gas (ANG. This study is concerned to characterize and evaluate potency of bambooswat (Gigantochloa verticillata as aprecursor of activated carbon for ANG application. Examinations conducted wereproximate, ultimate, chemical composisition tests and microstructure observation. The results showed that bambooswathave a lignin content 22.9920%, cellulose 44.2247%, volatile 88.32%, carbon 43.42%, ash 1.83%, silica 1.8664% andnitrogen

  1. Performance modeling of network data services

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, R.A.; Pierson, L.G.

    1997-01-01

    Networks at major computational organizations are becoming increasingly complex. The introduction of large massively parallel computers and supercomputers with gigabyte memories are requiring greater and greater bandwidth for network data transfers to widely dispersed clients. For networks to provide adequate data transfer services to high performance computers and remote users connected to them, the networking components must be optimized from a combination of internal and external performance criteria. This paper describes research done at Sandia National Laboratories to model network data services and to visualize the flow of data from source to sink when using the data services.

  2. Probabilistic Radiological Performance Assessment Modeling and Uncertainty

    Science.gov (United States)

    Tauxe, J.

    2004-12-01

    A generic probabilistic radiological Performance Assessment (PA) model is presented. The model, built using the GoldSim systems simulation software platform, concerns contaminant transport and dose estimation in support of decision making with uncertainty. Both the U.S. Nuclear Regulatory Commission (NRC) and the U.S. Department of Energy (DOE) require assessments of potential future risk to human receptors of disposal of LLW. Commercially operated LLW disposal facilities are licensed by the NRC (or agreement states), and the DOE operates such facilities for disposal of DOE-generated LLW. The type of PA model presented is probabilistic in nature, and hence reflects the current state of knowledge about the site by using probability distributions to capture what is expected (central tendency or average) and the uncertainty (e.g., standard deviation) associated with input parameters, and propagating through the model to arrive at output distributions that reflect expected performance and the overall uncertainty in the system. Estimates of contaminant release rates, concentrations in environmental media, and resulting doses to human receptors well into the future are made by running the model in Monte Carlo fashion, with each realization representing a possible combination of input parameter values. Statistical summaries of the results can be compared to regulatory performance objectives, and decision makers are better informed of the inherently uncertain aspects of the model which supports their decision-making. While this information may make some regulators uncomfortable, they must realize that uncertainties which were hidden in a deterministic analysis are revealed in a probabilistic analysis, and the chance of making a correct decision is now known rather than hoped for. The model includes many typical features and processes that would be part of a PA, but is entirely fictitious. This does not represent any particular site and is meant to be a generic example. A

  3. Performance assessment modeling of pyrometallurgical process wasteforms

    International Nuclear Information System (INIS)

    Nutt, W.M.; Hill, R.N.; Bullen, D.B.

    1995-01-01

    Performance assessment analyses have been completed to estimate the behavior of high-level nuclear wasteforms generated from the pyrometallurgical processing of liquid metal reactor (LMR) and light water reactor (LWR) spent nuclear fuel. Waste emplaced in the proposed repository at Yucca Mountain is investigated as the basis for the study. The resulting cumulative actinide and fission product releases to the accessible environment within a 100,000 year period from the various pyrometallurgical process wasteforms are compared to those of directly disposed LWR spent fuel using the same total repository system model. The impact of differing radionuclide transport models on the overall release characteristics is investigated

  4. Model description and evaluation of model performance: DOSDIM model

    International Nuclear Information System (INIS)

    Lewyckyj, N.; Zeevaert, T.

    1996-01-01

    DOSDIM was developed to assess the impact to man from routine and accidental atmospheric releases. It is a compartmental, deterministic, radiological model. For an accidental release, dynamic transfer are used in opposition to a routine release for which equilibrium transfer factors are used. Parameters values were chosen to be conservative. Transfer between compartments are described by first-order differential equations. 2 figs

  5. Future integrated aquifer vulnerability assessment considering land use / land cover and climate change using DRASTIC and SWAT

    Science.gov (United States)

    Jang, W.; Engel, B.; Chaubey, I.

    2015-12-01

    Climate change causes significant changes to temperature regimes and precipitation patterns across the world. Such alterations in climate pose serious risks for not only inland freshwater ecosystems but also groundwater systems, and may adversely affect numerous critical services they provide to humans. All groundwater results from precipitation, and precipitation is affected by climate change. Climate change is also influenced by land use / land cover (LULC) change and vice versa. According to Intergovernmental Panel on Climate Change (IPCC) reports, climate change is caused by global warming which is generated by the increase of greenhouse gas (GHG) emissions in the atmosphere. LULC change is a major driving factor causing an increase in GHG emissions. LULC change data (years 2006-2100) will be produced by the Land Transformation Model (LTM) which simulates spatial patterns of LULC change over time. MIROC5 (years 2006-2100) will be obtained considering GCMs and ensemble characteristics such as resolution and trend of temperature and precipitation which is a consistency check with observed data from local weather stations and historical data from GCMs output data. Thus, MIROC5 will be used to account for future climate change scenarios and relationship between future climate change and alteration of groundwater quality in this study. For efficient groundwater resources management, integrated aquifer vulnerability assessments (= intrinsic vulnerability + hazard potential assessment) are required. DRASTIC will be used to evaluate intrinsic vulnerability, and aquifer hazard potential will be evaluated by Soil and Water Assessment Tool (SWAT) which can simulate pollution potential from surface and transport properties of contaminants. Thus, for effective integrated aquifer vulnerability assessment for LULC and climate change in the Midwestern United States, future projected LULC and climate data from the LTM and GCMs will be incorporated with DRASTIC and SWAT. It is

  6. Modelling and evaluation of surgical performance using hidden Markov models.

    Science.gov (United States)

    Megali, Giuseppe; Sinigaglia, Stefano; Tonet, Oliver; Dario, Paolo

    2006-10-01

    Minimally invasive surgery has become very widespread in the last ten years. Since surgeons experience difficulties in learning and mastering minimally invasive techniques, the development of training methods is of great importance. While the introduction of virtual reality-based simulators has introduced a new paradigm in surgical training, skill evaluation methods are far from being objective. This paper proposes a method for defining a model of surgical expertise and an objective metric to evaluate performance in laparoscopic surgery. Our approach is based on the processing of kinematic data describing movements of surgical instruments. We use hidden Markov model theory to define an expert model that describes expert surgical gesture. The model is trained on kinematic data related to exercises performed on a surgical simulator by experienced surgeons. Subsequently, we use this expert model as a reference model in the definition of an objective metric to evaluate performance of surgeons with different abilities. Preliminary results show that, using different topologies for the expert model, the method can be efficiently used both for the discrimination between experienced and novice surgeons, and for the quantitative assessment of surgical ability.

  7. Hybrid Modeling Improves Health and Performance Monitoring

    Science.gov (United States)

    2007-01-01

    Scientific Monitoring Inc. was awarded a Phase I Small Business Innovation Research (SBIR) project by NASA's Dryden Flight Research Center to create a new, simplified health-monitoring approach for flight vehicles and flight equipment. The project developed a hybrid physical model concept that provided a structured approach to simplifying complex design models for use in health monitoring, allowing the output or performance of the equipment to be compared to what the design models predicted, so that deterioration or impending failure could be detected before there would be an impact on the equipment's operational capability. Based on the original modeling technology, Scientific Monitoring released I-Trend, a commercial health- and performance-monitoring software product named for its intelligent trending, diagnostics, and prognostics capabilities, as part of the company's complete ICEMS (Intelligent Condition-based Equipment Management System) suite of monitoring and advanced alerting software. I-Trend uses the hybrid physical model to better characterize the nature of health or performance alarms that result in "no fault found" false alarms. Additionally, the use of physical principles helps I-Trend identify problems sooner. I-Trend technology is currently in use in several commercial aviation programs, and the U.S. Air Force recently tapped Scientific Monitoring to develop next-generation engine health-management software for monitoring its fleet of jet engines. Scientific Monitoring has continued the original NASA work, this time under a Phase III SBIR contract with a joint NASA-Pratt & Whitney aviation security program on propulsion-controlled aircraft under missile-damaged aircraft conditions.

  8. Incorporation of the equilibrium temperature approach in a Soil and Water Assessment Tool hydroclimatological stream temperature model

    Science.gov (United States)

    Du, Xinzhong; Shrestha, Narayan Kumar; Ficklin, Darren L.; Wang, Junye

    2018-04-01

    Stream temperature is an important indicator for biodiversity and sustainability in aquatic ecosystems. The stream temperature model currently in the Soil and Water Assessment Tool (SWAT) only considers the impact of air temperature on stream temperature, while the hydroclimatological stream temperature model developed within the SWAT model considers hydrology and the impact of air temperature in simulating the water-air heat transfer process. In this study, we modified the hydroclimatological model by including the equilibrium temperature approach to model heat transfer processes at the water-air interface, which reflects the influences of air temperature, solar radiation, wind speed and streamflow conditions on the heat transfer process. The thermal capacity of the streamflow is modeled by the variation of the stream water depth. An advantage of this equilibrium temperature model is the simple parameterization, with only two parameters added to model the heat transfer processes. The equilibrium temperature model proposed in this study is applied and tested in the Athabasca River basin (ARB) in Alberta, Canada. The model is calibrated and validated at five stations throughout different parts of the ARB, where close to monthly samplings of stream temperatures are available. The results indicate that the equilibrium temperature model proposed in this study provided better and more consistent performances for the different regions of the ARB with the values of the Nash-Sutcliffe Efficiency coefficient (NSE) greater than those of the original SWAT model and the hydroclimatological model. To test the model performance for different hydrological and environmental conditions, the equilibrium temperature model was also applied to the North Fork Tolt River Watershed in Washington, United States. The results indicate a reasonable simulation of stream temperature using the model proposed in this study, with minimum relative error values compared to the other two models

  9. Multilevel Modeling of the Performance Variance

    Directory of Open Access Journals (Sweden)

    Alexandre Teixeira Dias

    2012-12-01

    Full Text Available Focusing on the identification of the role played by Industry on the relations between Corporate Strategic Factors and Performance, the hierarchical multilevel modeling method was adopted when measuring and analyzing the relations between the variables that comprise each level of analysis. The adequacy of the multilevel perspective to the study of the proposed relations was identified and the relative importance analysis point out to the lower relevance of industry as a moderator of the effects of corporate strategic factors on performance, when the latter was measured by means of return on assets, and that industry don‟t moderates the relations between corporate strategic factors and Tobin‟s Q. The main conclusions of the research are that the organizations choices in terms of corporate strategy presents a considerable influence and plays a key role on the determination of performance level, but that industry should be considered when analyzing the performance variation despite its role as a moderator or not of the relations between corporate strategic factors and performance.

  10. Modelling fuel cell performance using artificial intelligence

    Science.gov (United States)

    Ogaji, S. O. T.; Singh, R.; Pilidis, P.; Diacakis, M.

    Over the last few years, fuel cell technology has been increasing promisingly its share in the generation of stationary power. Numerous pilot projects are operating worldwide, continuously increasing the amount of operating hours either as stand-alone devices or as part of gas turbine combined cycles. An essential tool for the adequate and dynamic analysis of such systems is a software model that enables the user to assess a large number of alternative options in the least possible time. On the other hand, the sphere of application of artificial neural networks has widened covering such endeavours of life such as medicine, finance and unsurprisingly engineering (diagnostics of faults in machines). Artificial neural networks have been described as diagrammatic representation of a mathematical equation that receives values (inputs) and gives out results (outputs). Artificial neural networks systems have the capacity to recognise and associate patterns and because of their inherent design features, they can be applied to linear and non-linear problem domains. In this paper, the performance of the fuel cell is modelled using artificial neural networks. The inputs to the network are variables that are critical to the performance of the fuel cell while the outputs are the result of changes in any one or all of the fuel cell design variables, on its performance. Critical parameters for the cell include the geometrical configuration as well as the operating conditions. For the neural network, various network design parameters such as the network size, training algorithm, activation functions and their causes on the effectiveness of the performance modelling are discussed. Results from the analysis as well as the limitations of the approach are presented and discussed.

  11. Modelling fuel cell performance using artificial intelligence

    Energy Technology Data Exchange (ETDEWEB)

    Ogaji, S.O.T.; Singh, R.; Pilidis, P.; Diacakis, M. [Power Propulsion and Aerospace Engineering Department, Centre for Diagnostics and Life Cycle Costs, Cranfield University (United Kingdom)

    2006-03-09

    Over the last few years, fuel cell technology has been increasing promisingly its share in the generation of stationary power. Numerous pilot projects are operating worldwide, continuously increasing the amount of operating hours either as stand-alone devices or as part of gas turbine combined cycles. An essential tool for the adequate and dynamic analysis of such systems is a software model that enables the user to assess a large number of alternative options in the least possible time. On the other hand, the sphere of application of artificial neural networks has widened covering such endeavours of life such as medicine, finance and unsurprisingly engineering (diagnostics of faults in machines). Artificial neural networks have been described as diagrammatic representation of a mathematical equation that receives values (inputs) and gives out results (outputs). Artificial neural networks systems have the capacity to recognise and associate patterns and because of their inherent design features, they can be applied to linear and non-linear problem domains. In this paper, the performance of the fuel cell is modelled using artificial neural networks. The inputs to the network are variables that are critical to the performance of the fuel cell while the outputs are the result of changes in any one or all of the fuel cell design variables, on its performance. Critical parameters for the cell include the geometrical configuration as well as the operating conditions. For the neural network, various network design parameters such as the network size, training algorithm, activation functions and their causes on the effectiveness of the performance modelling are discussed. Results from the analysis as well as the limitations of the approach are presented and discussed. (author)

  12. Modelling the predictive performance of credit scoring

    Directory of Open Access Journals (Sweden)

    Shi-Wei Shen

    2013-07-01

    Research purpose: The purpose of this empirical paper was to examine the predictive performance of credit scoring systems in Taiwan. Motivation for the study: Corporate lending remains a major business line for financial institutions. However, in light of the recent global financial crises, it has become extremely important for financial institutions to implement rigorous means of assessing clients seeking access to credit facilities. Research design, approach and method: Using a data sample of 10 349 observations drawn between 1992 and 2010, logistic regression models were utilised to examine the predictive performance of credit scoring systems. Main findings: A test of Goodness of fit demonstrated that credit scoring models that incorporated the Taiwan Corporate Credit Risk Index (TCRI, micro- and also macroeconomic variables possessed greater predictive power. This suggests that macroeconomic variables do have explanatory power for default credit risk. Practical/managerial implications: The originality in the study was that three models were developed to predict corporate firms’ defaults based on different microeconomic and macroeconomic factors such as the TCRI, asset growth rates, stock index and gross domestic product. Contribution/value-add: The study utilises different goodness of fits and receiver operator characteristics during the examination of the robustness of the predictive power of these factors.

  13. Predicting fecal coliform using the interval-to-interval approach and SWAT in the Miyun watershed, China.

    Science.gov (United States)

    Bai, Jianwen; Shen, Zhenyao; Yan, Tiezhu; Qiu, Jiali; Li, Yangyang

    2017-06-01

    Pathogens in manure can cause waterborne-disease outbreaks, serious illness, and even death in humans. Therefore, information about the transformation and transport of bacteria is crucial for determining their source. In this study, the Soil and Water Assessment Tool (SWAT) was applied to simulate fecal coliform bacteria load in the Miyun Reservoir watershed, China. The data for the fecal coliform were obtained at three sampling sites, Chenying (CY), Gubeikou (GBK), and Xiahui (XH). The calibration processes of the fecal coliform were conducted using the CY and GBK sites, and validation was conducted at the XH site. An interval-to-interval approach was designed and incorporated into the processes of fecal coliform calibration and validation. The 95% confidence interval of the predicted values and the 95% confidence interval of measured values were considered during calibration and validation in the interval-to-interval approach. Compared with the traditional point-to-point comparison, this method can improve simulation accuracy. The results indicated that the simulation of fecal coliform using the interval-to-interval approach was reasonable for the watershed. This method could provide a new research direction for future model calibration and validation studies.

  14. CASTOR detector. Model, objectives and simulated performance

    International Nuclear Information System (INIS)

    Angelis, A. L. S.; Mavromanolakis, G.; Panagiotou, A. D.; Aslanoglou, X.; Nicolis, N.; Lobanov, M.; Erine, S.; Kharlov, Y. V.; Bogolyubsky, M. Y.; Kurepin, A. B.; Chileev, K.; Wlodarczyk, Z.

    2001-01-01

    It is presented a phenomenological model describing the formation and evolution of a Centauro fireball in the baryon-rich region in nucleus-nucleus interactions in the upper atmosphere and at the LHC. The small particle multiplicity and imbalance of electromagnetic and hadronic content characterizing a Centauro event and also the strongly penetrating particles (assumed to be strangelets) frequently accompanying them can be naturally explained. It is described the CASTOR calorimeter, a sub detector of the ALICE experiment dedicated to the search for Centauro in the very forward, baryon-rich region of central Pb+Pb collisions at the LHC. The basic characteristics and simulated performance of the calorimeter are presented

  15. OpenMP parallelization of a gridded SWAT (SWATG)

    Science.gov (United States)

    Zhang, Ying; Hou, Jinliang; Cao, Yongpan; Gu, Juan; Huang, Chunlin

    2017-12-01

    Large-scale, long-term and high spatial resolution simulation is a common issue in environmental modeling. A Gridded Hydrologic Response Unit (HRU)-based Soil and Water Assessment Tool (SWATG) that integrates grid modeling scheme with different spatial representations also presents such problems. The time-consuming problem affects applications of very high resolution large-scale watershed modeling. The OpenMP (Open Multi-Processing) parallel application interface is integrated with SWATG (called SWATGP) to accelerate grid modeling based on the HRU level. Such parallel implementation takes better advantage of the computational power of a shared memory computer system. We conducted two experiments at multiple temporal and spatial scales of hydrological modeling using SWATG and SWATGP on a high-end server. At 500-m resolution, SWATGP was found to be up to nine times faster than SWATG in modeling over a roughly 2000 km2 watershed with 1 CPU and a 15 thread configuration. The study results demonstrate that parallel models save considerable time relative to traditional sequential simulation runs. Parallel computations of environmental models are beneficial for model applications, especially at large spatial and temporal scales and at high resolutions. The proposed SWATGP model is thus a promising tool for large-scale and high-resolution water resources research and management in addition to offering data fusion and model coupling ability.

  16. Role of Facilities Available and Un-Available in Attracting of Tourist in Swat Valley Pakistan

    Directory of Open Access Journals (Sweden)

    Akbar Jalaluddin

    2017-01-01

    Full Text Available Natural landscape is an important resource for mountainous regions and play crucial role in tourism development. Tourism play a key role in economic development of a country. Developing tourist areas is the key to meet the expectations of mountain inhabitants, tourists, and the general public outside of mountainous areas. In order to know tourist perception, problems, and role of landscape & horticulture plants in the field of tourism. A research study entitled “Role of facilities available and un-available in attracting of tourist in swat valley Pakistan “The data was collected from the respondents through a questionnaire survey and analyzed using percentages, frequencies and Chi-square test (where applicable. The analyzed data revealed that most of the respondent (55 % considered natural green environment as a reason for their visit and 67 % respondents wanted to visit with their friends and were satisfied with the tourist area, respectively. Most of the respondent (39 % observed throwing of surplus food as major waste materials which turned the beautiful green environment into unattractive environment. Most of the visitors (52 % dislike un-cleanliness of the locality, 74% respondents felt ill effect due to deforestation.53 % tourist disagree with the current maintenance of the locality by tourism department. The most missed facilities were non availability of dustbins and children playing areas. 75 % respondents agreed with the fact that most of the people (local inhabitants as well as tourist were unaware with regard to maintenance activities of the area 15.7 % respondent agreed that road system should be improved to access most of the greenery in the locality, respectively to aware local people and tourist regarding maintenance of the locality will improve tourism in Swat valley. The studies need to be develop for the improvement of existing as well as artificial landscape of the tourist area (Kalam and Malamjabba of Swat valley.

  17. The COD Model: Simulating Workgroup Performance

    Science.gov (United States)

    Biggiero, Lucio; Sevi, Enrico

    Though the question of the determinants of workgroup performance is one of the most central in organization science, precise theoretical frameworks and formal demonstrations are still missing. In order to fill in this gap the COD agent-based simulation model is here presented and used to study the effects of task interdependence and bounded rationality on workgroup performance. The first relevant finding is an algorithmic demonstration of the ordering of interdependencies in terms of complexity, showing that the parallel mode is the most simplex, followed by the sequential and then by the reciprocal. This result is far from being new in organization science, but what is remarkable is that now it has the strength of an algorithmic demonstration instead of being based on the authoritativeness of some scholar or on some episodic empirical finding. The second important result is that the progressive introduction of realistic limits to agents' rationality dramatically reduces workgroup performance and addresses to a rather interesting result: when agents' rationality is severely bounded simple norms work better than complex norms. The third main finding is that when the complexity of interdependence is high, then the appropriate coordination mechanism is agents' direct and active collaboration, which means teamwork.

  18. Model for measuring complex performance in an aviation environment

    International Nuclear Information System (INIS)

    Hahn, H.A.

    1988-01-01

    An experiment was conducted to identify models of pilot performance through the attainment and analysis of concurrent verbal protocols. Sixteen models were identified. Novice and expert pilots differed with respect to the models they used. Models were correlated to performance, particularly in the case of expert subjects. Models were not correlated to performance shaping factors (i.e. workload). 3 refs., 1 tab

  19. Development of LEAP-JET code for sodium-water reaction analysis. Validation by sodium-water reaction tests (SWAT-1R)

    International Nuclear Information System (INIS)

    Seino, Hiroshi; Hamada, Hirotsugu

    2004-03-01

    The sodium-water reaction event in an FBR steam generator (SG) has influence on the safety, economical efficiency, etc. of the plant, so that the selection of design base leak (DBL) of the SG is considered as one of the important matters. The clarification of the sodium-water reaction phenomenon and the development of an analysis model are necessary to estimate the sodium-water reaction event with high accuracy and rationality in selecting the DBL. The reaction jet model is pointed out as a part of the necessary improvements to evaluate the overheating tube rupture of large SGs, since the behavior of overheating tube rupture is largely affected by the reaction jet conditions outside the tube. Therefore, LEAP-JET has been developed as an analysis code for the simulation of sodium-water reactions. This document shows the validation of the LEAP-JET code by the Sodium-Water Reaction Test (SWAT-1R). The following results have been obtained: (1) The reaction rate constant, K, is estimated at between 0.001≤K≤0.1 from the LEAP-JET analysis of the SWAT-1R data. (2) The analytical results on the high-temperature region and the behaviors of reaction consumption (Na, H 2 O) and products (H 2 , NaOH, Na 2 O) are considered to be physically reasonable. (3) The LEAP-JET analysis shows the tendency of overestimation in the maximum temperature and temperature distribution of the reaction jet. (4) In the LEAP-JET analysis, the numerical calculation becomes unstably, especially in the mesh containing quite small sodium mass. Therefore, it is necessary to modify the computational algorism to stabilize it and obtain the optimum value of K in sodium-water reactions. (author)

  20. Numerical modeling capabilities to predict repository performance

    International Nuclear Information System (INIS)

    1979-09-01

    This report presents a summary of current numerical modeling capabilities that are applicable to the design and performance evaluation of underground repositories for the storage of nuclear waste. The report includes codes that are available in-house, within Golder Associates and Lawrence Livermore Laboratories; as well as those that are generally available within the industry and universities. The first listing of programs are in-house codes in the subject areas of hydrology, solute transport, thermal and mechanical stress analysis, and structural geology. The second listing of programs are divided by subject into the following categories: site selection, structural geology, mine structural design, mine ventilation, hydrology, and mine design/construction/operation. These programs are not specifically designed for use in the design and evaluation of an underground repository for nuclear waste; but several or most of them may be so used

  1. Modelling saline intrusion for repository performance assessment

    International Nuclear Information System (INIS)

    Jackson, C.P.

    1989-04-01

    UK Nirex Ltd are currently considering the possibility of disposal of radioactive waste by burial in deep underground repositories. The natural pathway for radionuclides from such a repository to return to Man's immediate environment (the biosphere) is via groundwater. Thus analyses of the groundwater flow in the neighbourhood of a possible repository, and consequent radionuclide transport form an important part of a performance assessment for a repository. Some of the areas in the UK that might be considered as possible locations for a repository are near the coast. If a repository is located in a coastal region seawater may intrude into the groundwater flow system. As seawater is denser than fresh water buoyancy forces acting on the intruding saline water may have significant effects on the groundwater flow system, and consequently on the time for radionuclides to return to the biosphere. Further, the chemistry of the repository near-field may be strongly influenced by the salinity of the groundwater. It is therefore important for Nirex to have a capability for reliably modelling saline intrusion to an appropriate degree of accuracy in order to make performance assessments for a repository in a coastal region. This report describes work undertaken in the Nirex Research programme to provide such a capability. (author)

  2. 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.

  3. High-performance phase-field modeling

    KAUST Repository

    Vignal, Philippe

    2015-04-27

    Many processes in engineering and sciences involve the evolution of interfaces. Among the mathematical frameworks developed to model these types of problems, the phase-field method has emerged as a possible solution. Phase-fields nonetheless lead to complex nonlinear, high-order partial differential equations, whose solution poses mathematical and computational challenges. Guaranteeing some of the physical properties of the equations has lead to the development of efficient algorithms and discretizations capable of recovering said properties by construction [2, 5]. This work builds-up on these ideas, and proposes novel discretization strategies that guarantee numerical energy dissipation for both conserved and non-conserved phase-field models. The temporal discretization is based on a novel method which relies on Taylor series and ensures strong energy stability. It is second-order accurate, and can also be rendered linear to speed-up the solution process [4]. The spatial discretization relies on Isogeometric Analysis, a finite element method that possesses the k-refinement technology and enables the generation of high-order, high-continuity basis functions. These basis functions are well suited to handle the high-order operators present in phase-field models. Two-dimensional and three dimensional results of the Allen-Cahn, Cahn-Hilliard, Swift-Hohenberg and phase-field crystal equation will be presented, which corroborate the theoretical findings, and illustrate the robustness of the method. Results related to more challenging examples, namely the Navier-Stokes Cahn-Hilliard and a diusion-reaction Cahn-Hilliard system, will also be presented. The implementation was done in PetIGA and PetIGA-MF, high-performance Isogeometric Analysis frameworks [1, 3], designed to handle non-linear, time-dependent problems.

  4. Soil transmitted helminthiasis in different occupational groups in Swat, Khyber Pakhtunkhwa, Pakistan.

    Science.gov (United States)

    Khan, Wali; Nisa, Noorun; Khan, Aly

    2017-07-01

    We investigated the prevalence of geohelminth parasites in farmers, education concerned and shepherd of Swat, Khyber Pakhtunkhwa, Pakistan. A total of 1041 stool samples were examined from January 2006 to December 2008 using direct smear (Normal saline and Lugol's Iodine solution) the concentration methods and procedures. Seven hundred and sixty three (73.2%) individuals were found infected with one or more than one geohelminth parasites. Four hundred and eighteen (54.7%) were infected with single parasite and three hundred forty five (45.3%) with multiple infections. Ascaris lumbricoides 460 (53.0%), Trichuris trichura 228 (26.2%), Enterobius vermicularis 123 (14.1%) and Ancylostoma duedenale 56 (6.45%) were detected. The adults were found more parasitized than children and males were more infected than females. Shepherds were found more infected than farmers and education concerned. Although Swat is an area with poor hygiene located in temperate zone near the border of Afghanistan and China. The prevalence of reported geohelminth parasites here compared with the same studies is unexpectedly high. These types of studies should continue time to time to know the hazardous of such parasitic infections for the betterment of the human health.

  5. Small hydropower spot prediction using SWAT and a diversion algorithm, case study: Upper Citarum Basin

    Science.gov (United States)

    Kardhana, Hadi; Arya, Doni Khaira; Hadihardaja, Iwan K.; Widyaningtyas, Riawan, Edi; Lubis, Atika

    2017-11-01

    Small-Scale Hydropower (SHP) had been important electric energy power source in Indonesia. Indonesia is vast countries, consists of more than 17.000 islands. It has large fresh water resource about 3 m of rainfall and 2 m of runoff. Much of its topography is mountainous, remote but abundant with potential energy. Millions of people do not have sufficient access to electricity, some live in the remote places. Recently, SHP development was encouraged for energy supply of the places. Development of global hydrology data provides opportunity to predict distribution of hydropower potential. In this paper, we demonstrate run-of-river type SHP spot prediction tool using SWAT and a river diversion algorithm. The use of Soil and Water Assessment Tool (SWAT) with input of CFSR (Climate Forecast System Re-analysis) of 10 years period had been implemented to predict spatially distributed flow cumulative distribution function (CDF). A simple algorithm to maximize potential head of a location by a river diversion expressing head race and penstock had been applied. Firm flow and power of the SHP were estimated from the CDF and the algorithm. The tool applied to Upper Citarum River Basin and three out of four existing hydropower locations had been well predicted. The result implies that this tool is able to support acceleration of SHP development at earlier phase.

  6. Onions in the farming systems of the Swat Valley, Northern Pakistan : Implications for research and extension

    Directory of Open Access Journals (Sweden)

    Defoer, T.

    1993-01-01

    Full Text Available Onion cultivation in Swat Valley, Northern Pakistan, is increasingly becoming important, replacing wheat in the Rabi (winter season. The area increased from 1000 ha in 1986 to 3000 ha in 1991. Due to its relatively recent importance as a cash crop, information on : (1 management practices, (2 factors determining yields, and (3 the economics of onion cultivation, was hardly available. A diagnostic study organized in 1991 addresses these issues. Its results indicate that onion yields and the economics of onion cultivation are significantly affected by : (1 high seed rates in nurseries, (2 use of poorly drained basin type nurseries, (3 late transplanting, (4 high weed infestation in onion fields, and (5 early harvesting. Despite the 67 % higher input costs, induced by seed rates 20 times higher as usually recommended, onion cultivation in Swat Valley is attractive. Net benefits amount to approximately Rs. 45000 (1800 US$ per ha or 2 times as high as the net benefits per ha of wheat cultivation.

  7. DETRA: Model description and evaluation of model performance

    International Nuclear Information System (INIS)

    Suolanen, V.

    1996-01-01

    The computer code DETRA is a generic tool for environmental transfer analyses of radioactive or stable substances. The code has been applied for various purposes, mainly problems related to the biospheric transfer of radionuclides both in safety analyses of disposal of nuclear wastes and in consideration of foodchain exposure pathways in the analyses of off-site consequences of reactor accidents. For each specific application an individually tailored conceptual model can be developed. The biospheric transfer analyses performed by the code are typically carried out for terrestrial, aquatic and food chain applications. 21 refs, 35 figs, 15 tabs

  8. Baking oven improvement by performance modelling

    Energy Technology Data Exchange (ETDEWEB)

    1994-04-01

    The first phase of the project included both the derivation of an oven model and the development of a portable, rapid-response heat-flux sensor. Heat flux (defined as the instantaneous rate of heat flow per unit at the surface of the baking biscuit and expressed in W/cm[sup 2]) has been shown to be a more useful measure of oven performance than temperature alone. Fixed-point heat-flux sensors have already been developed and marketed, but a need was expressed at the start of this project for a travelling sensor which could be used to construct a more detailed picture of heat-flux variation in an oven. The travelling monitor developed can be used to measure variations in the heat flux experienced at the surface of products being baked in a travelling oven, both when oven conditions are fixed and when they are varied. It can also be used to identify the optimum locations within an oven for fixed heat-flux probes. It has been used effectively throughout the project for both purposes. Fuel savings of 18% and 21%, respectively, were achieved with two ovens. (author)

  9. Modeling of Faecal Contamination in Water from Catchment to Shellfish Growing Area

    OpenAIRE

    Bougeard, Morgane; Le Saux, Jean-claude; Perenne, Nicolas; Le Guyader, Soizick; Pommepuy, Monique

    2009-01-01

    During rainstorms, watersheds can introduce large amounts of faecal pollution into the rivers and sea, leading to shellfish contamination. In this study, we assessed Escherichia coli fluxes from a catchment, and their impact on estuarine water quality, using two assembled models. For the catchment, the agro-hydrological model SWAT was implemented integrating land uses, soil, topography, rainfall and other climatic data on Daoulas watershed (France). Initially, the SWAT model was calibrated an...

  10. The Five Key Questions of Human Performance Modeling.

    Science.gov (United States)

    Wu, Changxu

    2018-01-01

    Via building computational (typically mathematical and computer simulation) models, human performance modeling (HPM) quantifies, predicts, and maximizes human performance, human-machine system productivity and safety. This paper describes and summarizes the five key questions of human performance modeling: 1) Why we build models of human performance; 2) What the expectations of a good human performance model are; 3) What the procedures and requirements in building and verifying a human performance model are; 4) How we integrate a human performance model with system design; and 5) What the possible future directions of human performance modeling research are. Recent and classic HPM findings are addressed in the five questions to provide new thinking in HPM's motivations, expectations, procedures, system integration and future directions.

  11. PV Performance Modeling Methods and Practices: Results from the 4th PV Performance Modeling Collaborative Workshop.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-03-01

    In 2014, the IEA PVPS Task 13 added the PVPMC as a formal activity to its technical work plan for 2014-2017. The goal of this activity is to expand the reach of the PVPMC to a broader international audience and help to reduce PV performance modeling uncertainties worldwide. One of the main deliverables of this activity is to host one or more PVPMC workshops outside the US to foster more international participation within this collaborative group. This report reviews the results of the first in a series of these joint IEA PVPS Task 13/PVPMC workshops. The 4th PV Performance Modeling Collaborative Workshop was held in Cologne, Germany at the headquarters of TÜV Rheinland on October 22-23, 2015.

  12. Modelling and simulating fire tube boiler performance

    DEFF Research Database (Denmark)

    Sørensen, K.; Condra, T.; Houbak, Niels

    2003-01-01

    A model for a flue gas boiler covering the flue gas and the water-/steam side has been formulated. The model has been formulated as a number of sub models that are merged into an overall model for the complete boiler. Sub models have been defined for the furnace, the convection zone (split in 2......: a zone submerged in water and a zone covered by steam), a model for the material in the boiler (the steel) and 2 models for resp. the water/steam zone (the boiling) and the steam. The dynamic model has been developed as a number of Differential-Algebraic-Equation system (DAE). Subsequently Mat......Lab/Simulink has been applied for carrying out the simulations. To be able to verify the simulated results experiments has been carried out on a full scale boiler plant....

  13. Integration of nitrogen dynamics into the Noah-MP land surface model v1.1 for climate and environmental predictions

    International Nuclear Information System (INIS)

    Cai, X.; Zhang, X.

    2016-01-01

    Climate and terrestrial biosphere models consider nitrogen an important factor in limiting plant carbon uptake, while operational environmental models view nitrogen as the leading pollutant causing eutrophication in water bodies. The community Noah land surface model with multi-parameterization options (Noah-MP) is unique in that it is the next-generation land surface model for the Weather Research and Forecasting meteorological model and for the operational weather/climate models in the National Centers for Environmental Prediction. Here in this study, we add a capability to Noah-MP to simulate nitrogen dynamics by coupling the Fixation and Uptake of Nitrogen (FUN) plant model and the Soil and Water Assessment Tool (SWAT) soil nitrogen dynamics. This model development incorporates FUN's state-of-the-art concept of carbon cost theory and SWAT's strength in representing the impacts of agricultural management on the nitrogen cycle. Parameterizations for direct root and mycorrhizal-associated nitrogen uptake, leaf retranslocation, and symbiotic biological nitrogen fixation are employed from FUN, while parameterizations for nitrogen mineralization, nitrification, immobilization, volatilization, atmospheric deposition, and leaching are based on SWAT. The coupled model is then evaluated at the Kellogg Biological Station – a Long Term Ecological Research site within the US Corn Belt. Results show that the model performs well in capturing the major nitrogen state/flux variables (e.g., soil nitrate and nitrate leaching). Furthermore, the addition of nitrogen dynamics improves the modeling of net primary productivity and evapotranspiration. The model improvement is expected to advance the capability of Noah-MP to simultaneously predict weather and water quality in fully coupled Earth system models.

  14. Models and criteria for waste repository performance

    International Nuclear Information System (INIS)

    Smith, C.F.; Cohen, J.J.

    1981-03-01

    A primary objective of the Waste Management Program is to assure that public health is protected. Predictive modeling, to some extent, will play a role in assuring that this objective is met. This paper considers the requirements and limitations of predictive modeling in providing useful inputs to waste management decision making. Criteria development needs and the relation between criteria and models are also discussed

  15. Sustaining Team Performance: A Systems Model\\

    Science.gov (United States)

    1979-07-31

    member performance of specific behaviors" ( Nivea et al., 1978, p. 59). They have identified four major performance categories, and several performance...within the fire direction center several artillerymen work additively. The number of men in the fire direction center does not add steps to the sequence...Instructional strategies for training men of high and low aptitude. HumRRO-TR-73-10. Alexandria, VA: Human Resources Organization, April 1973. Blum, M.L. and

  16. Models and criteria for LLW disposal performance

    International Nuclear Information System (INIS)

    Smith, C.F.; Cohen, J.J.

    1980-12-01

    A primary objective of the Low Level Waste (LLW) Management Program is to assure that public health is protected. Predictive modeling, to some extent, will play a role in meeting this objective. This paper considers the requirements and limitations of predictive modeling in providing useful inputs to waste mangement decision making. In addition, criteria development needs and the relation between criteria and models are discussed

  17. Models and criteria for LLW disposal performance

    International Nuclear Information System (INIS)

    Smith, C.F.; Cohen, J.J.

    1980-01-01

    A primary objective of the Low Level Waste (LLW) Management Program is to assure that public health is protected. Predictive modeling, to some extent, will play a role in meeting this objective. This paper considers the requirements and limitations of predictive modeling in providing useful inputs to waste management decision making. In addition, criteria development needs and the relation between criteria and models are discussed

  18. Model Performance Evaluation and Scenario Analysis (MPESA) Tutorial

    Science.gov (United States)

    The model performance evaluation consists of metrics and model diagnostics. These metrics provides modelers with statistical goodness-of-fit measures that capture magnitude only, sequence only, and combined magnitude and sequence errors.

  19. Water quality modelling in the San Antonio River Basin driven by radar rainfall data

    OpenAIRE

    Almoutaz Elhassan; Hongjie Xie; Ahmed A. Al-othman; James Mcclelland; Hatim O. Sharif

    2016-01-01

    Continuous monitoring of stream water quality is needed as it has significant impacts on human and ecological health and well-being. Estimating water quality between sampling dates requires model simulation based on the available geospatial and water quality data for a given watershed. Models such as the Soil and Water Assessment Tool (SWAT) can be used to estimate the missing water quality data. In this study, SWAT was used to estimate water quality at a monitoring station near the outlet of...

  20. Prevalence and morphology of helminth parasites of fish from river swat, khyber pakhtunkhwa

    International Nuclear Information System (INIS)

    Ahmed, N.; Ayaz, S.; Shams, S.

    2014-01-01

    A study of the helminth parasites of fish of river swat was conducted from September, 2012 to August, 2013. A total of 250 fish belonging to five genera and six species were examined. The parasites collected were diplozoon khyberensis, bathybothrium rectangulum, bothriocephalus, nippotaenia, cucullanidae, proteocephalus, rhabdochona charsaddiensis, rhabdochona schizothoracis and neoechynorhynchus devdevi. They were indentified by morphological characteristics through microscopic techniques. Overall prevalence of the fish parasites was 58% (145/250. Among these schizothorax plageostomus fish 93.04% |(107/115), schizothorax labiatus 61.11% (33/54), salmo trutta fario 17.85% (05/28), Gara gotyla 0% (0/09), rita rita 0% (0/25) and oncorhynchus mykiss were 0% |(0/19). The intensity of the parasite varied from 1% to 9.2%. Among them high intensity was noted in rhabdochona schizothoracis (9.2%) and schizothorax labiatus. (author)

  1. Assessing ways to combat eutrophication in a Chinese drinking water reservoir using SWAT

    DEFF Research Database (Denmark)

    Nielsen, Anders; Trolle, Dennis; Me, W

    2013-01-01

    Across China, nutrient losses associated with agricultural production and domestic sewage have triggered eutrophication, and local managers are challenged to comply with drinking water quality requirements. Evidently, the improvement of water quality should be targeted holistically and encompass...... in land and livestock management and sewage treatment on nutrient export and derived consequences for water quality in the Chinese subtropical Kaiping (Dashahe) drinking water reservoir (supplying 0.4 million people). The critical load of TP was estimated to 13.5 tonnes yr–1 in order to comply...... both point sources and surface activities within the watershed of a reservoir. We expanded the ordinary Soil Water Assessment Tool – (SWAT) with a widely used empirical equation to estimate total phosphorus (TP) concentrations in lakes and reservoirs. Subsequently, we examined the effects of changes...

  2. Modelling Flexible Pavement Response and Performance

    DEFF Research Database (Denmark)

    Ullidtz, Per

    This textbook is primarily concerned with models for predicting the future condition of flexible pavements, as a function of traffic loading, climate, materials, etc., using analytical-empirical methods.......This textbook is primarily concerned with models for predicting the future condition of flexible pavements, as a function of traffic loading, climate, materials, etc., using analytical-empirical methods....

  3. Detailed Performance Model for Photovoltaic Systems: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Tian, H.; Mancilla-David, F.; Ellis, K.; Muljadi, E.; Jenkins, P.

    2012-07-01

    This paper presents a modified current-voltage relationship for the single diode model. The single-diode model has been derived from the well-known equivalent circuit for a single photovoltaic cell. The modification presented in this paper accounts for both parallel and series connections in an array.

  4. Modelling Flat Spring performance using FEA

    International Nuclear Information System (INIS)

    Fatola, B O; Keogh, P; Hicks, B

    2009-01-01

    This paper reports how the stiffness of a Flat Spring can be predicted using nonlinear Finite Element Analysis (FEA). The analysis of a Flat Spring is a nonlinear problem involving contact mechanics, geometric nonlinearity and material property nonlinearity. Research has been focused on improving the accuracy of the model by identifying and exploring the significant assumptions contributing to errors. This paper presents results from some of the models developed using FEA software. The validation process is shown to identify where improvements can be made to the model assumptions to increase the accuracy of prediction. The goal is to achieve an accuracy level of ±10 % as the intention is to replace practical testing with FEA modelling, thereby reducing the product development time and cost. Results from the FEA models are compared with experimental results to validate the accuracy.

  5. Phytoecological evaluation with detail floristic appraisal of the vegetation arround Malam Jabba, Swat, Pakistan.

    Science.gov (United States)

    Rashid, Abdur; Swati, Mohammad Farooq; Sher, Hassan; Al-Yemeni, Mohammad N

    2011-12-01

    To determine the present status of plant communities and their possible association with the habitat in Malam Jabba, Swat, Pakistan. A study on the phytoecology was conducted in various ecologically important sites of Malam Jabba, Swat, Pakistan from 2002 to 2004. The altitude of these sites ranged from 1 200 m to 3 200 m. Quadrat method was used for evaluation of plants communities and the data on these attributes was converted to relative values. The plant communities were named after 3 leading species with highest importance values. Biological spectrum of the flora based on the life form was prepared by following Raunkiar's life form classes. The floristic composition and structure of the study area were found to be 200 species belonging to 75 families. Asteraceae, Lamiaceae and Poaceae were important families in the study area. The biological spectrum showed that therophytic and hemicrytophytic life form and micro-nonophyllous leaf sizes were dominant in the area. The air and soil temperatures were decreasing with increasing elevation. Both the air and soil temperatures were relatively higher in south slopes than on the northeast slopes. The vegetation analysis of the area indicated eleven plant communities around the area. The present vegetation is the relics of moist temperate coniferous forest in the area. The communities reflect highly deteriorated conditions. Both the structure and composition of the surrounding vegetation were associated with the types of habitats. The conservation of the remaining populations of the reported communities will be best achieved by proper time of sustainable harvesting. It is only possible with the participation of local communities.

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

    Science.gov (United States)

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

    2017-12-01

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

  7. Modeling and optimization of LCD optical performance

    CERN Document Server

    Yakovlev, Dmitry A; Kwok, Hoi-Sing

    2015-01-01

    The aim of this book is to present the theoretical foundations of modeling the optical characteristics of liquid crystal displays, critically reviewing modern modeling methods and examining areas of applicability. The modern matrix formalisms of optics of anisotropic stratified media, most convenient for solving problems of numerical modeling and optimization of LCD, will be considered in detail. The benefits of combined use of the matrix methods will be shown, which generally provides the best compromise between physical adequacy and accuracy with computational efficiency and optimization fac

  8. Integrated thermodynamic model for ignition target performance

    Directory of Open Access Journals (Sweden)

    Springer P.T.

    2013-11-01

    Full Text Available We have derived a 3-dimensional synthetic model for NIF implosion conditions, by predicting and optimizing fits to a broad set of x-ray and nuclear diagnostics obtained on each shot. By matching x-ray images, burn width, neutron time-of-flight ion temperature, yield, and fuel ρr, we obtain nearly unique constraints on conditions in the hotspot and fuel in a model that is entirely consistent with the observables. This model allows us to determine hotspot density, pressure, areal density (ρr, total energy, and other ignition-relevant parameters not available from any single diagnostic. This article describes the model and its application to National Ignition Facility (NIF tritium–hydrogen–deuterium (THD and DT implosion data, and provides an explanation for the large yield and ρr degradation compared to numerical code predictions.

  9. The CREATIVE Decontamination Performance Evaluation Model

    National Research Council Canada - National Science Library

    Shelly, Erin E

    2008-01-01

    The project objective is to develop a semi-empirical, deterministic model to characterize and predict laboratory-scale decontaminant efficacy and hazards for a range of: chemical agents (current focus on HD...

  10. Mathematical Modeling of Circadian/Performance Countermeasures

    Data.gov (United States)

    National Aeronautics and Space Administration — We developed and refined our current mathematical model of circadian rhythms to incorporate melatonin as a marker rhythm. We used an existing physiologically based...

  11. A universal Model-R Coupler to facilitate the use of R functions for model calibration and analysis

    Science.gov (United States)

    Wu, Yiping; Liu, Shuguang; Yan, Wende

    2014-01-01

    Mathematical models are useful in various fields of science and engineering. However, it is a challenge to make a model utilize the open and growing functions (e.g., model inversion) on the R platform due to the requirement of accessing and revising the model's source code. To overcome this barrier, we developed a universal tool that aims to convert a model developed in any computer language to an R function using the template and instruction concept of the Parameter ESTimation program (PEST) and the operational structure of the R-Soil and Water Assessment Tool (R-SWAT). The developed tool (Model-R Coupler) is promising because users of any model can connect an external algorithm (written in R) with their model to implement various model behavior analyses (e.g., parameter optimization, sensitivity and uncertainty analysis, performance evaluation, and visualization) without accessing or modifying the model's source code.

  12. Modelling of Supercapacitors: Factors Influencing Performance

    OpenAIRE

    Kroupa, M; Offer, GJ; Kosek, J

    2016-01-01

    The utilizable capacitance of Electrochemical Double Layer Capacitors (EDLCs) is a function of the frequency at which they are operated and this is strongly dependent on the construction and physical parameters of the device. We simulate the dynamic behavior of an EDLC using a spatially resolved model based on the porous electrode theory. The model of Verbrugge and Liu (J. Electrochem. Soc. 152, D79 (2005)) was extended with a dimension describing the transport into the carbon particle pores....

  13. A unified tool for performance modelling and prediction

    International Nuclear Information System (INIS)

    Gilmore, Stephen; Kloul, Leila

    2005-01-01

    We describe a novel performability modelling approach, which facilitates the efficient solution of performance models extracted from high-level descriptions of systems. The notation which we use for our high-level designs is the Unified Modelling Language (UML) graphical modelling language. The technology which provides the efficient representation capability for the underlying performance model is the multi-terminal binary decision diagram (MTBDD)-based PRISM probabilistic model checker. The UML models are compiled through an intermediate language, the stochastic process algebra PEPA, before translation into MTBDDs for solution. We illustrate our approach on a real-world analysis problem from the domain of mobile telephony

  14. Using SWAT-MODFLOW to simulate groundwater flow and groundwater-surface water interactions in an intensively irrigated stream-aquifer system

    Science.gov (United States)

    Wei, X.; Bailey, R. T.

    2017-12-01

    Agricultural irrigated watersheds in semi-arid regions face challenges such as waterlogging, high soil salinity, reduced crop yield, and leaching of chemical species due to extreme shallow water tables resulting from long-term intensive irrigation. Hydrologic models can be used to evaluate the impact of land management practices on water yields and groundwater-surface water interactions in such regions. In this study, the newly developed SWAT-MODFLOW, a coupled surface/subsurface hydrologic model, is applied to a 950 km2 watershed in the Lower Arkansas River Valley (southeastern Colorado). The model accounts for the influence of canal diversions, irrigation applications, groundwater pumping, and earth canal seepage losses. The model provides a detailed description of surface and subsurface flow processes, thereby enabling detailed description of watershed processes such as runoff, infiltration, in-streamflow, three-dimensional groundwater flow in a heterogeneous aquifer system with sources and sinks (e.g. pumping, seepage to subsurface drains), and spatially-variable surface and groundwater exchange. The model was calibrated and tested against stream discharge from 5 stream gauges in the Arkansas River and its tributaries, groundwater levels from 70 observation wells, and evapotranspiration (ET) data estimated from satellite (ReSET) data during the 1999 to 2007 period. Since the water-use patterns within the study area are typical of many other irrigated river valleys in the United States and elsewhere, this modeling approach is transferable to other regions.

  15. Developing an Energy Performance Modeling Startup Kit

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2012-10-01

    In 2011, the NAHB Research Center began assessing the needs and motivations of residential remodelers regarding energy performance remodeling. This report outlines: the current remodeling industry and the role of energy efficiency; gaps and barriers to adding energy efficiency into remodeling; and support needs of professional remodelers to increase sales and projects involving improving home energy efficiency.

  16. Modeling vibrato and portamento in music performance

    NARCIS (Netherlands)

    Desain, P.W.M.; Honing, H.J.

    1999-01-01

    Research in the psychology of music dealing with expression is often concerned with the discrete aspects of music performance, and mainly concentrates on the study of piano music (partly because of the ease with which piano music can be reduced to discrete note events). However, on other

  17. Evaluating Models of Human Performance: Safety-Critical Systems Applications

    Science.gov (United States)

    Feary, Michael S.

    2012-01-01

    This presentation is part of panel discussion on Evaluating Models of Human Performance. The purpose of this panel is to discuss the increasing use of models in the world today and specifically focus on how to describe and evaluate models of human performance. My presentation will focus on discussions of generating distributions of performance, and the evaluation of different strategies for humans performing tasks with mixed initiative (Human-Automation) systems. I will also discuss issues with how to provide Human Performance modeling data to support decisions on acceptability and tradeoffs in the design of safety critical systems. I will conclude with challenges for the future.

  18. Comparison of performance of simulation models for floor heating

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Svendsen, Svend

    2005-01-01

    This paper describes the comparison of performance of simulation models for floor heating with different level of detail in the modelling process. The models are compared in an otherwise identical simulation model containing room model, walls, windows, ceiling and ventilation system. By exchanging...

  19. Evaluating Performances of Traffic Noise Models | Oyedepo ...

    African Journals Online (AJOL)

    Traffic noise in decibel dB(A) were measured at six locations using 407780A Integrating Sound Level Meter, while spot speed and traffic volume were collected with cine-camera. The predicted sound exposure level (SEL) was evaluated using Burgess, British and FWHA model. The average noise level obtained are 77.64 ...

  20. HANDOVER MANAGEABILITY AND PERFORMANCE MODELING IN

    African Journals Online (AJOL)

    SOFTLINKS DIGITAL

    and Corporate Information Systems: A Proactive Mitigation. Response Model. 1 ... known malware variants, and more than ... has defined authentication as the process of identifying ... providing protection via Access Controls,. Encryption and ... to use their technical prowess to teach .... Developing and distributing approved.

  1. Persistence Modeling for Assessing Marketing Strategy Performance

    NARCIS (Netherlands)

    M.G. Dekimpe (Marnik); D.M. Hanssens (Dominique)

    2003-01-01

    textabstractThe question of long-run market response lies at the heart of any marketing strategy that tries to create a sustainable competitive advantage for the firm or brand. A key challenge, however, is that only short-run results of marketing actions are readily observable. Persistence modeling

  2. HANDOVER MANAGEABILITY AND PERFORMANCE MODELING IN

    African Journals Online (AJOL)

    SOFTLINKS DIGITAL

    Software is better modelled with the use of UML diagrams like use cases which ... analysis and design according to [1] is to transform the 'black .... The system request the user to enter his/her user_id .... The corresponding changes are saved.

  3. Mathematical modeling of optical glazing performance

    NARCIS (Netherlands)

    Nijnatten, van P.A.; Wittwer, V.; Granqvist, C.G.; Lampert, C.M.

    1994-01-01

    Mathematical modelling can be a powerful tool in the design and optimalization of glazing. By calculation, the specifications of a glazing design and the optimal design parameters can be predicted without building costly prototypes first. Furthermore, properties which are difficult to measure, like

  4. Some useful characteristics of performance models

    International Nuclear Information System (INIS)

    Worledge, D.H.

    1985-01-01

    This paper examines the demands placed upon models of human cognitive decision processes in application to Probabilistic Risk Assessment. Successful models, for this purpose, should, 1) be based on proven or plausible psychological knowledge, e.g., Rasmussen's mental schematic, 2) incorporate opportunities for slips, 3) take account of the recursive nature, in time, of corrections to mistaken actions, and 4) depend on the crew's predominant mental states that accompany such recursions. The latter is equivalent to an explicit coupling between input and output of Rasmussen's mental schematic. A family of such models is proposed with observable rate processes mediating the (conscious) mental states involved. It is expected that the cumulative probability distributions corresponding to the individual rate processes can be identified with probability-time correlations of the HCR Human Cognitive Reliability type discussed elsewhere in this session. The functional forms of the conditional rates are intuitively shown to have simple characteristics that lead to a strongly recursive stochastic process with significant predictive capability. Models of the type proposed have few parts and form a representation that is intentionally far short of a fully transparent exposition of the mental process in order to avoid making impossible demands on data

  5. High-performance phase-field modeling

    KAUST Repository

    Vignal, Philippe; Sarmiento, Adel; Cortes, Adriano Mauricio; Dalcin, L.; Collier, N.; Calo, Victor M.

    2015-01-01

    and phase-field crystal equation will be presented, which corroborate the theoretical findings, and illustrate the robustness of the method. Results related to more challenging examples, namely the Navier-Stokes Cahn-Hilliard and a diusion-reaction Cahn-Hilliard system, will also be presented. The implementation was done in PetIGA and PetIGA-MF, high-performance Isogeometric Analysis frameworks [1, 3], designed to handle non-linear, time-dependent problems.

  6. Atmospheric statistical dynamic models. Model performance: the Lawrence Livermore Laboratoy Zonal Atmospheric Model

    International Nuclear Information System (INIS)

    Potter, G.L.; Ellsaesser, H.W.; MacCracken, M.C.; Luther, F.M.

    1978-06-01

    Results from the zonal model indicate quite reasonable agreement with observation in terms of the parameters and processes that influence the radiation and energy balance calculations. The model produces zonal statistics similar to those from general circulation models, and has also been shown to produce similar responses in sensitivity studies. Further studies of model performance are planned, including: comparison with July data; comparison of temperature and moisture transport and wind fields for winter and summer months; and a tabulation of atmospheric energetics. Based on these preliminary performance studies, however, it appears that the zonal model can be used in conjunction with more complex models to help unravel the problems of understanding the processes governing present climate and climate change. As can be seen in the subsequent paper on model sensitivity studies, in addition to reduced cost of computation, the zonal model facilitates analysis of feedback mechanisms and simplifies analysis of the interactions between processes

  7. SWAT3.1 - the integrated burnup code system driving continuous energy Monte Carlo codes MVP and MCNP

    International Nuclear Information System (INIS)

    Suyama, Kenya; Mochizuki, Hiroki; Takada, Tomoyuki; Ryufuku, Susumu; Okuno, Hiroshi; Murazaki, Minoru; Ohkubo, Kiyoshi

    2009-05-01

    Integrated burnup calculation code system SWAT is a system that combines neutronics calculation code SRAC,which is widely used in Japan, and point burnup calculation code ORIGEN2. It has been used to evaluate the composition of the uranium, plutonium, minor actinides and the fission products in the spent nuclear fuel. Based on this idea, the integrated burnup calculation code system SWAT3.1 was developed by combining the continuous energy Monte Carlo code MVP and MCNP, and ORIGEN2. This enables us to treat the arbitrary fuel geometry and to generate the effective cross section data to be used in the burnup calculation with few approximations. This report describes the outline, input data instruction and several examples of the calculation. (author)

  8. Individualized Biomathematical Modeling of Fatigue and Performance

    Science.gov (United States)

    2008-05-29

    Interactions and Transitions 53 New Discoveries , Inventions, or Patent Disclosures 56 FA9550-06-1-0055 Individualized Biomathematical Modeling of Fatigue...Old Dominion University, not supported on grant) Daniel J. Mollicone, Ph.D. ( Pulsar Informatics, Inc., not supported on grant) Christopher G...Mott, M.S. ( Pulsar Informatics, Inc., not supported on grant) Erik Olofsen, M.S. (Leiden University, the Netherlands, not supported on grant

  9. Effects of Energy Development on Hydrologic Response: a Multi-Scale Modeling Approach

    Science.gov (United States)

    Vithanage, J.; Miller, S. N.; Berendsen, M.; Caffrey, P. A.; Bellis, J.; Schuler, R.

    2013-12-01

    Potential impacts of energy development on surface hydrology in western Wyoming were assessed using spatially explicit hydrological models. Currently there are proposals to develop over 800 new oil and gas wells in the 218,000 acre-sized LaBarge development area that abuts the Wyoming Range and contributes runoff to the Upper Green River (approximately 1 well per 2 square miles). The intensity of development raises questions relating to impacts on the hydrological cycle, water quality, erosion and sedimentation. We developed landscape management scenarios relating to current disturbance and proposed actions put forth by the energy operators to provide inputs to spatially explicit hydrologic models. Differences between the scenarios were derived to quantify the changes and analyse the impacts to the project area. To perform this research, the Automated Watershed Assessment Tool (AGWA) was enhanced by adding different management practices suitable for the region, including the reclamation of disturbed lands over time. The AGWA interface was used to parameterize and execute two hydrologic models: the Soil and Water Assessment Tool (SWAT) and the KINEmatic Runoff and EROSion model (KINEROS2). We used freely available data including SSURGO soils, Multi-Resolution Landscape Consortium (MRLC) land cover, and 10m resolution terrain data to derive suitable initial parameters for the models. The SWAT model was manually calibrated using an innovative method at the monthly level; observed daily rainfall and temperature inputs were used as a function of elevation considering the local climate effects. Higher temporal calibration was not possible due to a lack of adequate climate and runoff data. The Nash Sutcliff efficiencies of two calibrated watersheds at the monthly scale exceeded 0.95. Results of the AGWA/SWAT simulations indicate a range of sensitivity to disturbance due to heterogeneous soil and terrain characteristics over a simulated time period of 10 years. The KINEROS

  10. An Empirical Study of a Solo Performance Assessment Model

    Science.gov (United States)

    Russell, Brian E.

    2015-01-01

    The purpose of this study was to test a hypothesized model of solo music performance assessment. Specifically, this study investigates the influence of technique and musical expression on perceptions of overall performance quality. The Aural Musical Performance Quality (AMPQ) measure was created to measure overall performance quality, technique,…

  11. Developing an Energy Performance Modeling Startup Kit

    Energy Technology Data Exchange (ETDEWEB)

    Wood, A.

    2012-10-01

    In 2011, the NAHB Research Center began the first part of the multi-year effort by assessing the needs and motivations of residential remodelers regarding energy performance remodeling. The scope is multifaceted - all perspectives will be sought related to remodeling firms ranging in size from small-scale, sole proprietor to national. This will allow the Research Center to gain a deeper understanding of the remodeling and energy retrofit business and the needs of contractors when offering energy upgrade services. To determine the gaps and the motivation for energy performance remodeling, the NAHB Research Center conducted (1) an initial series of focus groups with remodelers at the 2011 International Builders' Show, (2) a second series of focus groups with remodelers at the NAHB Research Center in conjunction with the NAHB Spring Board meeting in DC, and (3) quantitative market research with remodelers based on the findings from the focus groups. The goal was threefold, to: Understand the current remodeling industry and the role of energy efficiency; Identify the gaps and barriers to adding energy efficiency into remodeling; and Quantify and prioritize the support needs of professional remodelers to increase sales and projects involving improving home energy efficiency. This report outlines all three of these tasks with remodelers.

  12. Modeling the Mechanical Performance of Die Casting Dies

    Energy Technology Data Exchange (ETDEWEB)

    R. Allen Miller

    2004-02-27

    The following report covers work performed at Ohio State on modeling the mechanical performance of dies. The focus of the project was development and particularly verification of finite element techniques used to model and predict displacements and stresses in die casting dies. The work entails a major case study performed with and industrial partner on a production die and laboratory experiments performed at Ohio State.

  13. Modeling the marketing strategy-performance relationship : towards an hierarchical marketing performance framework

    NARCIS (Netherlands)

    Huizingh, Eelko K.R.E.; Zengerink, Evelien

    2001-01-01

    Accurate measurement of marketing performance is an important topic for both marketing academics and marketing managers. Many researchers have recognized that marketing performance measurement should go beyond financial measurement. In this paper we propose a conceptual framework that models

  14. Modeling and analysis to quantify MSE wall behavior and performance.

    Science.gov (United States)

    2009-08-01

    To better understand potential sources of adverse performance of mechanically stabilized earth (MSE) walls, a suite of analytical models was studied using the computer program FLAC, a numerical modeling computer program widely used in geotechnical en...

  15. Outline of sodium-water reaction test in case of large leak with SWAT-3 testing equipments

    International Nuclear Information System (INIS)

    Sato, Minoru

    1978-01-01

    The key component in sodium-cooled fast reactors in steam generators, and the sodium-water reaction owing to the break of heating tubes may cause serious damages in equipments and pipings. The main factor controlling this phenomenon is the rate of leak of water. When the rate of water leak is small, the propagation of heating tube breaking may occur owing to ''wastage phenomenon'', on the other hand, when the rate of water leak is large, the phenomena of explosive pressure and flow occur due to the reaction heat and a large quantity of hydrogen generated by the reaction. In PNC, the testing equipments of SWAT-2 for small water leak and SWAT-1 for large leak were constructed, and the development test has been carried out to establish the method of safety design experimentally. The synthetic test equipment for the safety of steam generators, SWAT-3, was constructed to carry out the large water leak test in the scale close to actual plants. The object of the test, the outline of the test equipment, the phenomena of pressure and flow in the water injection test, the confirmation of the occurrence of secondary breaking of adjacent heating tubes, and the disposal of reaction products are described in this paper. This test is till going on, and the final conclusion will be reported later. (Kako, I.)

  16. Characterization uncertainty and its effects on models and performance

    International Nuclear Information System (INIS)

    Rautman, C.A.; Treadway, A.H.

    1991-01-01

    Geostatistical simulation is being used to develop multiple geologic models of rock properties at the proposed Yucca Mountain repository site. Because each replicate model contains the same known information, and is thus essentially indistinguishable statistically from others, the differences between models may be thought of as representing the uncertainty in the site description. The variability among performance measures, such as ground water travel time, calculated using these replicate models therefore quantifies the uncertainty in performance that arises from uncertainty in site characterization

  17. Identifying the connective strength between model parameters and performance criteria

    Directory of Open Access Journals (Sweden)

    B. Guse

    2017-11-01

    Full Text Available In hydrological models, parameters are used to represent the time-invariant characteristics of catchments and to capture different aspects of hydrological response. Hence, model parameters need to be identified based on their role in controlling the hydrological behaviour. For the identification of meaningful parameter values, multiple and complementary performance criteria are used that compare modelled and measured discharge time series. The reliability of the identification of hydrologically meaningful model parameter values depends on how distinctly a model parameter can be assigned to one of the performance criteria. To investigate this, we introduce the new concept of connective strength between model parameters and performance criteria. The connective strength assesses the intensity in the interrelationship between model parameters and performance criteria in a bijective way. In our analysis of connective strength, model simulations are carried out based on a latin hypercube sampling. Ten performance criteria including Nash–Sutcliffe efficiency (NSE, Kling–Gupta efficiency (KGE and its three components (alpha, beta and r as well as RSR (the ratio of the root mean square error to the standard deviation for different segments of the flow duration curve (FDC are calculated. With a joint analysis of two regression tree (RT approaches, we derive how a model parameter is connected to different performance criteria. At first, RTs are constructed using each performance criterion as the target variable to detect the most relevant model parameters for each performance criterion. Secondly, RTs are constructed using each parameter as the target variable to detect which performance criteria are impacted by changes in the values of one distinct model parameter. Based on this, appropriate performance criteria are identified for each model parameter. In this study, a high bijective connective strength between model parameters and performance criteria

  18. New model performance index for engineering design of control systems

    Science.gov (United States)

    1970-01-01

    Performance index includes a model representing linear control-system design specifications. Based on a geometric criterion for approximation of the model by the actual system, the index can be interpreted directly in terms of the desired system response model without actually having the model's time response.

  19. Development of a Coupled Ocean-Hydrologic Model to Simulate Pollutant Transport in Singapore Coastal Waters

    Science.gov (United States)

    Chua, V. P.

    2015-12-01

    Intensive agricultural, economic and industrial activities in Singapore and Malaysia have made our coastal areas under high risk of water pollution. A coupled ocean-hydrologic model is employed to perform three-dimensional simulations of flow and pollutant transport in Singapore coastal waters. The hydrologic SWAT model is coupled with the coastal ocean SUNTANS model by outputting streamflow and pollutant concentrations from the SWAT model and using them as inputs for the SUNTANS model at common boundary points. The coupled model is calibrated with observed sea surface elevations and velocities, and high correlation coefficients that exceed 0.97 and 0.91 are found for sea surface elevations and velocities, respectively. The pollutants are modeled as Gaussian passive tracers, and are released at five upstream locations in Singapore coastal waters. During the Northeast monsoon, pollutants released in Source 1 (Johor River), Source 2 (Tiram River), Source 3 (Layang River) and Source 4 (Layau River) enter the Singapore Strait after 4 days of release and reach Sentosa Island within 9 days. Meanwhile, pollutants released in Source 5 (Kallang River) reach Sentosa Island after 4 days. During the Southwest monsoon, the dispersion time is roughly doubled, with pollutants from Sources 1 - 4 entering the Singapore Strait only after 12 days of release due to weak currents.

  20. Advanced Performance Modeling with Combined Passive and Active Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Dovrolis, Constantine [Georgia Inst. of Technology, Atlanta, GA (United States); Sim, Alex [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-04-15

    To improve the efficiency of resource utilization and scheduling of scientific data transfers on high-speed networks, the "Advanced Performance Modeling with combined passive and active monitoring" (APM) project investigates and models a general-purpose, reusable and expandable network performance estimation framework. The predictive estimation model and the framework will be helpful in optimizing the performance and utilization of networks as well as sharing resources with predictable performance for scientific collaborations, especially in data intensive applications. Our prediction model utilizes historical network performance information from various network activity logs as well as live streaming measurements from network peering devices. Historical network performance information is used without putting extra load on the resources by active measurement collection. Performance measurements collected by active probing is used judiciously for improving the accuracy of predictions.

  1. Analytic Ballistic Performance Model of Whipple Shields

    Science.gov (United States)

    Miller, J. E.; Bjorkman, M. D.; Christiansen, E. L.; Ryan, S. J.

    2015-01-01

    The dual-wall, Whipple shield is the shield of choice for lightweight, long-duration flight. The shield uses an initial sacrificial wall to initiate fragmentation and melt an impacting threat that expands over a void before hitting a subsequent shield wall of a critical component. The key parameters to this type of shield are the rear wall and its mass which stops the debris, as well as the minimum shock wave strength generated by the threat particle impact of the sacrificial wall and the amount of room that is available for expansion. Ensuring the shock wave strength is sufficiently high to achieve large scale fragmentation/melt of the threat particle enables the expansion of the threat and reduces the momentum flux of the debris on the rear wall. Three key factors in the shock wave strength achieved are the thickness of the sacrificial wall relative to the characteristic dimension of the impacting particle, the density and material cohesion contrast of the sacrificial wall relative to the threat particle and the impact speed. The mass of the rear wall and the sacrificial wall are desirable to minimize for launch costs making it important to have an understanding of the effects of density contrast and impact speed. An analytic model is developed here, to describe the influence of these three key factors. In addition this paper develops a description of a fourth key parameter related to fragmentation and its role in establishing the onset of projectile expansion.

  2. Soil and Water Assessment Tool model predictions of annual maximum pesticide concentrations in high vulnerability watersheds.

    Science.gov (United States)

    Winchell, Michael F; Peranginangin, Natalia; Srinivasan, Raghavan; Chen, Wenlin

    2018-05-01

    Recent national regulatory assessments of potential pesticide exposure of threatened and endangered species in aquatic habitats have led to increased need for watershed-scale predictions of pesticide concentrations in flowing water bodies. This study was conducted to assess the ability of the uncalibrated Soil and Water Assessment Tool (SWAT) to predict annual maximum pesticide concentrations in the flowing water bodies of highly vulnerable small- to medium-sized watersheds. The SWAT was applied to 27 watersheds, largely within the midwest corn belt of the United States, ranging from 20 to 386 km 2 , and evaluated using consistent input data sets and an uncalibrated parameterization approach. The watersheds were selected from the Atrazine Ecological Exposure Monitoring Program and the Heidelberg Tributary Loading Program, both of which contain high temporal resolution atrazine sampling data from watersheds with exceptionally high vulnerability to atrazine exposure. The model performance was assessed based upon predictions of annual maximum atrazine concentrations in 1-d and 60-d durations, predictions critical in pesticide-threatened and endangered species risk assessments when evaluating potential acute and chronic exposure to aquatic organisms. The simulation results showed that for nearly half of the watersheds simulated, the uncalibrated SWAT model was able to predict annual maximum pesticide concentrations within a narrow range of uncertainty resulting from atrazine application timing patterns. An uncalibrated model's predictive performance is essential for the assessment of pesticide exposure in flowing water bodies, the majority of which have insufficient monitoring data for direct calibration, even in data-rich countries. In situations in which SWAT over- or underpredicted the annual maximum concentrations, the magnitude of the over- or underprediction was commonly less than a factor of 2, indicating that the model and uncalibrated parameterization

  3. Trade potential and conservation issues of medicinal plants in district Swat, Pakistan

    International Nuclear Information System (INIS)

    Ali, H.; Ahmad, H.; Yousif, M.

    2012-01-01

    Use of medicinal plants for various health disorders is a common practice especially in rural areas. Poor economic condition and lack of modern health care facilities in remote areas are the major reasons for adopting traditional medicine. Mingora is considered as the main center of trade of medicinal plants not only of Swat but of the entire Hindu Kush-Himalayan Region of Pakistan. The city was analyzed for the trade potential of local medicinal plants. The present study reported trade and marketing profile of 99 species collected locally and sold in the national and international markets. A total of 99 taxa were collected belonging to 55 families and 80 genera. Helvellaceae was at the top among the largest families with 9 taxa, followed by Asteraceae and Solanacea with 8 and 6 taxa respectively. Among the life form Chamaephyte was at the top with 27 taxa (27.27%), followed by Hemicryptophyte, Phanerophyte, Therophyte, Geophyte and Parasite with 25 (25.25%), 24 (24.24%), 17 (20.20%), 2 (2.02%) and 1 taxa (1.01%), respectively. Market analysis revealed that annual production and its share to the market was 8.056 and 6.644 million kg during the years 2004-2005 and 2005-2006 whereas, it gave rise to the circulation of Rs. 4475.00 and Rs. 5084.70 millions, respectively. Thus quantity traded decreased due to the unsustainable collection in the wild, while amount circulated increased due to rise in price kg/sup -1/ as a result of increased demand from the national and international market. According to an estimate approximately 99,840 individuals (i.e. 8% of the total population of Swat) are associated with the collection or trade of these important medicinal plants in the valley. The study also revealed that availability of medicinal plants decreased day by day and this process is continued for the last two decades. According to local elders, most of the medicinal plants reported were abundant in the vicinities some 20 years back. However, their population was

  4. Performance of Air Pollution Models on Massively Parallel Computers

    DEFF Research Database (Denmark)

    Brown, John; Hansen, Per Christian; Wasniewski, Jerzy

    1996-01-01

    To compare the performance and use of three massively parallel SIMD computers, we implemented a large air pollution model on the computers. Using a realistic large-scale model, we gain detailed insight about the performance of the three computers when used to solve large-scale scientific problems...

  5. Performance Modeling of Communication Networks with Markov Chains

    CERN Document Server

    Mo, Jeonghoon

    2010-01-01

    This book is an introduction to Markov chain modeling with applications to communication networks. It begins with a general introduction to performance modeling in Chapter 1 where we introduce different performance models. We then introduce basic ideas of Markov chain modeling: Markov property, discrete time Markov chain (DTMe and continuous time Markov chain (CTMe. We also discuss how to find the steady state distributions from these Markov chains and how they can be used to compute the system performance metric. The solution methodologies include a balance equation technique, limiting probab

  6. Multitasking TORT Under UNICOS: Parallel Performance Models and Measurements

    International Nuclear Information System (INIS)

    Azmy, Y.Y.; Barnett, D.A.

    1999-01-01

    The existing parallel algorithms in the TORT discrete ordinates were updated to function in a UNI-COS environment. A performance model for the parallel overhead was derived for the existing algorithms. The largest contributors to the parallel overhead were identified and a new algorithm was developed. A parallel overhead model was also derived for the new algorithm. The results of the comparison of parallel performance models were compared to applications of the code to two TORT standard test problems and a large production problem. The parallel performance models agree well with the measured parallel overhead

  7. Multitasking TORT under UNICOS: Parallel performance models and measurements

    International Nuclear Information System (INIS)

    Barnett, A.; Azmy, Y.Y.

    1999-01-01

    The existing parallel algorithms in the TORT discrete ordinates code were updated to function in a UNICOS environment. A performance model for the parallel overhead was derived for the existing algorithms. The largest contributors to the parallel overhead were identified and a new algorithm was developed. A parallel overhead model was also derived for the new algorithm. The results of the comparison of parallel performance models were compared to applications of the code to two TORT standard test problems and a large production problem. The parallel performance models agree well with the measured parallel overhead

  8. Asymptotic performance modelling of DCF protocol with prioritized channel access

    Science.gov (United States)

    Choi, Woo-Yong

    2017-11-01

    Recently, the modification of the DCF (Distributed Coordination Function) protocol by the prioritized channel access was proposed to resolve the problem that the DCF performance worsens exponentially as more nodes exist in IEEE 802.11 wireless LANs. In this paper, an asymptotic analytical performance model is presented to analyze the MAC performance of the DCF protocol with the prioritized channel access.

  9. Improvement and comparison of likelihood functions for model calibration and parameter uncertainty analysis within a Markov chain Monte Carlo scheme

    Science.gov (United States)

    Cheng, Qin-Bo; Chen, Xi; Xu, Chong-Yu; Reinhardt-Imjela, Christian; Schulte, Achim

    2014-11-01

    In this study, the likelihood functions for uncertainty analysis of hydrological models are compared and improved through the following steps: (1) the equivalent relationship between the Nash-Sutcliffe Efficiency coefficient (NSE) and the likelihood function with Gaussian independent and identically distributed residuals is proved; (2) a new estimation method of the Box-Cox transformation (BC) parameter is developed to improve the effective elimination of the heteroscedasticity of model residuals; and (3) three likelihood functions-NSE, Generalized Error Distribution with BC (BC-GED) and Skew Generalized Error Distribution with BC (BC-SGED)-are applied for SWAT-WB-VSA (Soil and Water Assessment Tool - Water Balance - Variable Source Area) model calibration in the Baocun watershed, Eastern China. Performances of calibrated models are compared using the observed river discharges and groundwater levels. The result shows that the minimum variance constraint can effectively estimate the BC parameter. The form of the likelihood function significantly impacts on the calibrated parameters and the simulated results of high and low flow components. SWAT-WB-VSA with the NSE approach simulates flood well, but baseflow badly owing to the assumption of Gaussian error distribution, where the probability of the large error is low, but the small error around zero approximates equiprobability. By contrast, SWAT-WB-VSA with the BC-GED or BC-SGED approach mimics baseflow well, which is proved in the groundwater level simulation. The assumption of skewness of the error distribution may be unnecessary, because all the results of the BC-SGED approach are nearly the same as those of the BC-GED approach.

  10. Effect of farmyard manure, mineral fertilizers and mung bean residues on some microbiological properties of eroded soil in district Swat

    Directory of Open Access Journals (Sweden)

    M. Naeem

    2009-05-01

    Full Text Available The present study was conducted to evaluate the efficacy of organic and inorganic fertilizers and mung bean residues on improving microbiological properties of eroded lands of District Swat, North West Frontier Province (NWFP Pakistan under wheat-mung bean-wheat cropping system during 2006 to 2008. The experiment was laid out in RCBD split-plot arrangement. Mung bean was grown and a basal dose of 25-60 kg N-P2O5 ha-1 was applied. After mung bean harvest, three residues management practices, i.e., R+ (mung bean residues incorporated into soil, R- (mung bean residues removed and F (fallow were performed in the main-plots. Sub-plot factor consisted of six fertilizer treatments for wheat crop i.e., T1 (control, T2 (120 kg N ha-1, T3 (120-90-0 kg N-P2O5-K2O ha-1, T4 (120-90-60 kg N-P2O5-K2O ha-1, T5 (90-90-60 kg N-P2O5-K2O + 10 t FYM ha-1 and T6 (60-90-60 kg N-P2O5- K2O + 20 t FYM ha-1. The results showed that microbial activity, microbial biomass-C and-N, mineralizable C and N were highest with T6 as well as with the incorporation of mung bean residues (R+. Compared with control, T6 increased microbial biomass C, N, mineralizable C and N by 33.8, 164.1, 35.5 and 110.6% at surface and 38.4, 237.5, 38.7 and 124.1% at sub-surface soil, respectively, while R+ compared with fallow increased these properties by 33.7, 47.4, 21.4 and 32.2% at surface and 36.8, 51, 21.9 and 35.4% at sub-surface soil, respectively. Inclusion of mung bean with its residues incorporated and application of 20 t FYM ha-1 and reducing inorganic N fertilizer to 60 kg N ha-1 for wheat is recommended for improving microbiological properties of slightly eroded lands

  11. Switching performance of OBS network model under prefetched real traffic

    Science.gov (United States)

    Huang, Zhenhua; Xu, Du; Lei, Wen

    2005-11-01

    Optical Burst Switching (OBS) [1] is now widely considered as an efficient switching technique in building the next generation optical Internet .So it's very important to precisely evaluate the performance of the OBS network model. The performance of the OBS network model is variable in different condition, but the most important thing is that how it works under real traffic load. In the traditional simulation models, uniform traffics are usually generated by simulation software to imitate the data source of the edge node in the OBS network model, and through which the performance of the OBS network is evaluated. Unfortunately, without being simulated by real traffic, the traditional simulation models have several problems and their results are doubtable. To deal with this problem, we present a new simulation model for analysis and performance evaluation of the OBS network, which uses prefetched IP traffic to be data source of the OBS network model. The prefetched IP traffic can be considered as real IP source of the OBS edge node and the OBS network model has the same clock rate with a real OBS system. So it's easy to conclude that this model is closer to the real OBS system than the traditional ones. The simulation results also indicate that this model is more accurate to evaluate the performance of the OBS network system and the results of this model are closer to the actual situation.

  12. Maintenance personnel performance simulation (MAPPS): a model for predicting maintenance performance reliability in nuclear power plants

    International Nuclear Information System (INIS)

    Knee, H.E.; Krois, P.A.; Haas, P.M.; Siegel, A.I.; Ryan, T.G.

    1983-01-01

    The NRC has developed a structured, quantitative, predictive methodology in the form of a computerized simulation model for assessing maintainer task performance. Objective of the overall program is to develop, validate, and disseminate a practical, useful, and acceptable methodology for the quantitative assessment of NPP maintenance personnel reliability. The program was organized into four phases: (1) scoping study, (2) model development, (3) model evaluation, and (4) model dissemination. The program is currently nearing completion of Phase 2 - Model Development

  13. ECOPATH: Model description and evaluation of model performance

    International Nuclear Information System (INIS)

    Bergstroem, U.; Nordlinder, S.

    1996-01-01

    The model is based upon compartment theory and it is run in combination with a statistical error propagation method (PRISM, Gardner et al. 1983). It is intended to be generic for application on other sites with simple changing of parameter values. It was constructed especially for this scenario. However, it is based upon an earlier designed model for calculating relations between released amount of radioactivity and doses to critical groups (used for Swedish regulations concerning annual reports of released radioactivity from routine operation of Swedish nuclear power plants (Bergstroem och Nordlinder, 1991)). The model handles exposure from deposition on terrestrial areas as well as deposition on lakes, starting with deposition values. 14 refs, 16 figs, 7 tabs

  14. Statistical and Machine Learning Models to Predict Programming Performance

    OpenAIRE

    Bergin, Susan

    2006-01-01

    This thesis details a longitudinal study on factors that influence introductory programming success and on the development of machine learning models to predict incoming student performance. Although numerous studies have developed models to predict programming success, the models struggled to achieve high accuracy in predicting the likely performance of incoming students. Our approach overcomes this by providing a machine learning technique, using a set of three significant...

  15. Indonesian Private University Lecturer Performance Improvement Model to Improve a Sustainable Organization Performance

    Science.gov (United States)

    Suryaman

    2018-01-01

    Lecturer performance will affect the quality and carrying capacity of the sustainability of an organization, in this case the university. There are many models developed to measure the performance of teachers, but not much to discuss the influence of faculty performance itself towards sustainability of an organization. This study was conducted in…

  16. A Spectral Evaluation of Models Performances in Mediterranean Oak Woodlands

    Science.gov (United States)

    Vargas, R.; Baldocchi, D. D.; Abramowitz, G.; Carrara, A.; Correia, A.; Kobayashi, H.; Papale, D.; Pearson, D.; Pereira, J.; Piao, S.; Rambal, S.; Sonnentag, O.

    2009-12-01

    Ecosystem processes are influenced by climatic trends at multiple temporal scales including diel patterns and other mid-term climatic modes, such as interannual and seasonal variability. Because interactions between biophysical components of ecosystem processes are complex, it is important to test how models perform in frequency (e.g. hours, days, weeks, months, years) and time (i.e. day of the year) domains in addition to traditional tests of annual or monthly sums. Here we present a spectral evaluation using wavelet time series analysis of model performance in seven Mediterranean Oak Woodlands that encompass three deciduous and four evergreen sites. We tested the performance of five models (CABLE, ORCHIDEE, BEPS, Biome-BGC, and JULES) on measured variables of gross primary production (GPP) and evapotranspiration (ET). In general, model performance fails at intermediate periods (e.g. weeks to months) likely because these models do not represent the water pulse dynamics that influence GPP and ET at these Mediterranean systems. To improve the performance of a model it is critical to identify first where and when the model fails. Only by identifying where a model fails we can improve the model performance and use them as prognostic tools and to generate further hypotheses that can be tested by new experiments and measurements.

  17. FARMLAND: Model description and evaluation of model performance

    International Nuclear Information System (INIS)

    Attwood, C.; Fayers, C.; Mayall, A.; Brown, J.; Simmonds, J.R.

    1996-01-01

    The FARMLAND model was originally developed for use in connection with continuous, routine releases of radionuclides, but because it has many time-dependent features it has been developed further for a single accidental release. The most recent version of FARMLAND is flexible and can be used to predict activity concentrations in food as a function of time after both accidental and routine releases of radionuclides. The effect of deposition at different times of the year can be taken into account. FARMLAND contains a suite of models which simulate radionuclide transfer through different parts of the foodchain. The models can be used in different combinations and offer the flexibility to assess a variety of radiological situations. The main foods considered are green vegetables, grain products, root vegetables, milk, meat and offal from cattle, and meat and offal from sheep. A large variety of elements can be considered although the degree of complexity with which some are modelled is greater than others; isotopes of caesium, strontium and iodine are treated in greatest detail. 22 refs, 12 figs, 10 tabs

  18. FARMLAND: Model description and evaluation of model performance

    Energy Technology Data Exchange (ETDEWEB)

    Attwood, C; Fayers, C; Mayall, A; Brown, J; Simmonds, J R [National Radiological Protection Board, Chilton (United Kingdom)

    1996-09-01

    The FARMLAND model was originally developed for use in connection with continuous, routine releases of radionuclides, but because it has many time-dependent features it has been developed further for a single accidental release. The most recent version of FARMLAND is flexible and can be used to predict activity concentrations in food as a function of time after both accidental and routine releases of radionuclides. The effect of deposition at different times of the year can be taken into account. FARMLAND contains a suite of models which simulate radionuclide transfer through different parts of the foodchain. The models can be used in different combinations and offer the flexibility to assess a variety of radiological situations. The main foods considered are green vegetables, grain products, root vegetables, milk, meat and offal from cattle, and meat and offal from sheep. A large variety of elements can be considered although the degree of complexity with which some are modelled is greater than others; isotopes of caesium, strontium and iodine are treated in greatest detail. 22 refs, 12 figs, 10 tabs.

  19. Comparisons of Faulting-Based Pavement Performance Prediction Models

    Directory of Open Access Journals (Sweden)

    Weina Wang

    2017-01-01

    Full Text Available Faulting prediction is the core of concrete pavement maintenance and design. Highway agencies are always faced with the problem of lower accuracy for the prediction which causes costly maintenance. Although many researchers have developed some performance prediction models, the accuracy of prediction has remained a challenge. This paper reviews performance prediction models and JPCP faulting models that have been used in past research. Then three models including multivariate nonlinear regression (MNLR model, artificial neural network (ANN model, and Markov Chain (MC model are tested and compared using a set of actual pavement survey data taken on interstate highway with varying design features, traffic, and climate data. It is found that MNLR model needs further recalibration, while the ANN model needs more data for training the network. MC model seems a good tool for pavement performance prediction when the data is limited, but it is based on visual inspections and not explicitly related to quantitative physical parameters. This paper then suggests that the further direction for developing the performance prediction model is incorporating the advantages and disadvantages of different models to obtain better accuracy.

  20. Atomic scale simulations for improved CRUD and fuel performance modeling

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Anders David Ragnar [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cooper, Michael William Donald [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-06

    A more mechanistic description of fuel performance codes can be achieved by deriving models and parameters from atomistic scale simulations rather than fitting models empirically to experimental data. The same argument applies to modeling deposition of corrosion products on fuel rods (CRUD). Here are some results from publications in 2016 carried out using the CASL allocation at LANL.

  1. Modelling of Box Type Solar Cooker Performance in a Tropical ...

    African Journals Online (AJOL)

    Thermal performance model of box type solar cooker with loaded water is presented. The model was developed using the method of Funk to estimate cooking power in terms of climatic and design parameters for box type solar cooker in a tropical environment. Coefficients for each term used in the model were determined ...

  2. Mishal: A Case Study of a Deradicalization and Emancipation Program in SWAT Valley, Pakistan

    Directory of Open Access Journals (Sweden)

    Zubair Azam

    2017-06-01

    Full Text Available Nestled in the SWAT valley lies Pakistan’s earliest known deradicalization initiative for former militants, the Mishal Deradicalization and Emancipation Program (DREP. The Deradicalization program was launched following a military operation in 2009 against the Pakistan wing of the Taliban, namely, the Tehrik-e-Taliban Pakistan (TTP. The program aimed to deradicalize and rehabilitate arrested militants, with what officials claim is a 99 percent success rate and with more than 2,500 former Taliban fighters now ‘reformed’. The program abides by a ‘no blood on hand’ policy, whereby it only takes in militants who have not caused any bodily harm to others. In this paper, we analyze the deradicalization program and highlight the limits and challenges it faces. The paper also highlights the common individual and environmental factors among the beneficiary population of the deradicalization program. This study finds that most participants of the program belonged to large or broken families with weak socio-economic profiles. Additionally, these individuals had very little technical knowledge of religion. This study also finds that the program is more oriented towards re-integration rather than deradicalization due to its policy of inducting only low and mid-level cadre militants. The program also has other severe limitations including lack of credible religious scholars, limited financial and human resources.

  3. Health risks associated with heavy metals in the drinking water of Swat, northern Pakistan.

    Science.gov (United States)

    Lu, Yonglong; Khan, Hizbullah; Zakir, Shahida; Ihsanullah; Khan, Sardar; Khan, Akbar Ali; Wei, Luo; Wang, Tieyu

    2013-10-01

    The concentrations of heavy metals such as Cd, Cr, Cu, Mn, Ni, Pb and Zn were investigated in drinking water sources (surface and groundwater) collected from Swat valley, Khyber Pakhtunkhwa, Pakistan. The potential health risks of heavy metals to the local population and their possible source apportionment were also studied. Heavy metal concentrations were analysed using atomic absorption spectrometer and compared with permissible limits set by Pakistan Environmental Protection Agency and World Health Organization. The concentrations of Cd, Cr, Ni and Pb were higher than their respective permissible limits, while Cu, Mn and Zn concentrations were observed within their respective limits. Health risk indicators such as chronic daily intake (CDI) and health risk index (HRI) were calculated for adults and children separately. CDIs and HRIs of heavy metals were found in the order of Cr > Mn > Ni > Zn > Cd > Cu > Pb and Cd > Ni > Mn > Cr > Cu > Pb > Zn, respectively. HRIs of selected heavy metals in the drinking water were less than 1, indicating no health risk to the local people. Multivariate and univariate statistical analyses showed that geologic and anthropogenic activities were the possible sources of water contamination with heavy metals in the study area.

  4. Present state and future trends of pine forests of malam jabba, swat district, Pakistan

    International Nuclear Information System (INIS)

    Siddiqui, M. F.; Arsalan, M.; Hussain, M. I.; Iqbal, J.; Wahab, M.

    2015-01-01

    Present state and future trend of pine forests of Malam Jabba, Swat district, Pakistan explored. We focused on vegetation composition, structure, diversity and forests dynamics. Thirteen stands were sampled by Point Centered Quarter method. Among all stands four monospecific forests of Pinus wallichiana attained highest density ha-1 except in one stand where Picea smithiana attained 401 trees ha-1. Unlike density, the basal area m2 ha-1 of these stands varies stand to stand. Based on floristic composition and importance value index, five different communities viz Pinus wallichiana-Picea smithiana; Picea smithiana-Pinus wallichiana; Abies pindrow-Pinus wallichiana; Pinus wallichiana-Abies pindrow; Abies pindrow-Picea smithiana and 4 monospecific forests of Pinus wallichiana were recognized. Size class structure of forests showed marked influence of anthropogenic disturbance because not a single stand showed ideal regeneration pattern (inverse J shape distribution). Future of these forests is worst due to absence trees in small size classes. Gaps are also evident in most of the forest stands. Stand diversity, richness, equitability and Simpson dominance values formulated on single stand basis. Diversity of Abides pindrow and Pinus wallichiana stand was highest because these stand occupied dominant species, while lowest diversity observed in some Pinus wallichiana and Picea smithiana stand as these stands have mark difference between the dominance of two species. In the monospecific forests, the diversity level was zero, suggesting the monopolization of resources by one species or elimination of other tree species in these stands. (author)

  5. 'Mote' networks: A nano SWAT Team for the oilpatch

    Energy Technology Data Exchange (ETDEWEB)

    Ross, E.

    2004-05-01

    Wireless sensor networks installed in pumping stations, pipelines, or remote areas that monitor various parameters such as energy use, pressure or temperature, are the latest technology finding application in the oil and gas industry. The sensors (also called 'motes') can self-configure the network, including self-correction without downtime. Their principal function is to transfer information using the fastest, most reliable path and send data to the control system via a gateway. Key to the technology is the concept of mesh networks: instead of each mote having a single channel back to some form of a backbone, the system has multiple paths, similar to the Internet, which will find another path if one route is blocked. Each mote is about one inch in size; it is outfitted with a microprocessor, a radio that generates 900 megahertz and a number of other components that optimize the interaction between the radio and the microprocessor. In addition to communicating with each other, the motes also communicate with the client's own control system via a central collection point or gateway. One of the most promising applications is the 'rapid profiling kit' which compares to a SWAT team in which the network may be used to periodically verify other measurements and give them increased accuracy and greater resolution. Monitoring the health of machines by listening to any crunching and knocking is another potential application. 1 fig.

  6. Modelling Client Satisfaction Levels: The Impact of Contractor Performance

    Directory of Open Access Journals (Sweden)

    Robby Soetanto

    2012-11-01

    Full Text Available The performance of contractors is known to be a key determinant of client satisfaction.Here, using factor analysis, clients’ satisfaction is defined in several dimensions. Based onclients’ assessment of contractor performance, a number of satisfaction models developedusing the multiple regression (MR technique are presented. The models identify arange of variables encompassing contractor performance, project performance and respondent(i.e. client attributes as useful predictors of satisfaction levels. Contractor performanceattributes were found to be of utmost importance indicating that clientsatisfaction levels are mainly dependent on the performance of the contractor. Furthermore,findings suggest that subjectivity is to some extent prevalent in clients’ performanceassessment. The models demonstrate accurate and reliable predictive power as confirmedby validation tests. Contractors could use the models to help improve their performanceleading to more satisfied clients. This would also promote the development ofharmonious working relationships within the construction project coalition.

  7. Performance modeling of neighbor discovery in proactive routing protocols

    Directory of Open Access Journals (Sweden)

    Andres Medina

    2011-07-01

    Full Text Available It is well known that neighbor discovery is a critical component of proactive routing protocols in wireless ad hoc networks. However there is no formal study on the performance of proposed neighbor discovery mechanisms. This paper provides a detailed model of key performance metrics of neighbor discovery algorithms, such as node degree and the distribution of the distance to symmetric neighbors. The model accounts for the dynamics of neighbor discovery as well as node density, mobility, radio and interference. The paper demonstrates a method for applying these models to the evaluation of global network metrics. In particular, it describes a model of network connectivity. Validation of the models shows that the degree estimate agrees, within 5% error, with simulations for the considered scenarios. The work presented in this paper serves as a basis for the performance evaluation of remaining performance metrics of routing protocols, vital for large scale deployment of ad hoc networks.

  8. Conceptual adsorption models and open issues pertaining to performance assessment

    International Nuclear Information System (INIS)

    Serne, R.J.

    1992-01-01

    Recently several articles have been published that question the appropriateness of the distribution coefficient, Rd, concept to quantify radionuclide migration. Several distinct issues surrounding the modeling of nuclide retardation. The first section defines adsorption terminology and discusses various adsorption processes. The next section describes five commonly used adsorption conceptual models, specifically emphasizing what attributes that affect adsorption are explicitly accommodated in each model. I also review efforts to incorporate each adsorption model into performance assessment transport computer codes. The five adsorption conceptual models are (1) the constant Rd model, (2) the parametric Rd model, (3) isotherm adsorption models, (4) mass action adsorption models, and (5) surface-complexation with electrostatics models. The final section discusses the adequacy of the distribution ratio concept, the adequacy of transport calculations that rely on constant retardation factors and the status of incorporating sophisticated adsorption models into transport codes. 86 refs., 1 fig., 1 tab

  9. Conceptual adsorption models and open issues pertaining to performance assessment

    International Nuclear Information System (INIS)

    Serne, R.J.

    1991-10-01

    Recently several articles have been published that question the appropriateness of the distribution coefficient, Rd, concept to quantify radionuclide migration. Several distinct issues are raised by various critics. In this paper I provide some perspective on issues surrounding the modeling of nuclide retardation. The first section defines adsorption terminology and discusses various adsorption processes. The next section describes five commonly used adsorption conceptual models, specifically emphasizing what attributes that affect adsorption are explicitly accommodated in each model. I also review efforts to incorporate each adsorption model into performance assessment transport computer codes. The five adsorption conceptual models are (1) the constant Rd model, (2) the parametric Rd model, (3) isotherm adsorption models, (4) mass-action adsorption models, and (5) surface-complexation with electrostatics models. The final section discusses the adequacy of the distribution ratio concept, the adequacy of transport calculations that rely on constant retardation factors and the status of incorporating sophisticated adsorption models into transport codes

  10. Impact of reactive settler models on simulated WWTP performance

    DEFF Research Database (Denmark)

    Gernaey, Krist; Jeppsson, Ulf; Batstone, Damien J.

    2006-01-01

    for an ASM1 case study. Simulations with a whole plant model including the non-reactive Takacs settler model are used as a reference, and are compared to simulation results considering two reactive settler models. The first is a return sludge model block removing oxygen and a user-defined fraction of nitrate......, combined with a non-reactive Takacs settler. The second is a fully reactive ASM1 Takacs settler model. Simulations with the ASM1 reactive settler model predicted a 15.3% and 7.4% improvement of the simulated N removal performance, for constant (steady-state) and dynamic influent conditions respectively....... The oxygen/nitrate return sludge model block predicts a 10% improvement of N removal performance under dynamic conditions, and might be the better modelling option for ASM1 plants: it is computationally more efficient and it will not overrate the importance of decay processes in the settler....

  11. Planetary Suit Hip Bearing Model for Predicting Design vs. Performance

    Science.gov (United States)

    Cowley, Matthew S.; Margerum, Sarah; Harvil, Lauren; Rajulu, Sudhakar

    2011-01-01

    Designing a planetary suit is very complex and often requires difficult trade-offs between performance, cost, mass, and system complexity. In order to verifying that new suit designs meet requirements, full prototypes must eventually be built and tested with human subjects. Using computer models early in the design phase of new hardware development can be advantageous, allowing virtual prototyping to take place. Having easily modifiable models of the suit hard sections may reduce the time it takes to make changes to the hardware designs and then to understand their impact on suit and human performance. A virtual design environment gives designers the ability to think outside the box and exhaust design possibilities before building and testing physical prototypes with human subjects. Reductions in prototyping and testing may eventually reduce development costs. This study is an attempt to develop computer models of the hard components of the suit with known physical characteristics, supplemented with human subject performance data. Objectives: The primary objective was to develop an articulating solid model of the Mark III hip bearings to be used for evaluating suit design performance of the hip joint. Methods: Solid models of a planetary prototype (Mark III) suit s hip bearings and brief section were reverse-engineered from the prototype. The performance of the models was then compared by evaluating the mobility performance differences between the nominal hardware configuration and hardware modifications. This was accomplished by gathering data from specific suited tasks. Subjects performed maximum flexion and abduction tasks while in a nominal suit bearing configuration and in three off-nominal configurations. Performance data for the hip were recorded using state-of-the-art motion capture technology. Results: The results demonstrate that solid models of planetary suit hard segments for use as a performance design tool is feasible. From a general trend perspective

  12. Photovoltaic Reliability Performance Model v 2.0

    Energy Technology Data Exchange (ETDEWEB)

    2016-12-16

    PV-RPM is intended to address more “real world” situations by coupling a photovoltaic system performance model with a reliability model so that inverters, modules, combiner boxes, etc. can experience failures and be repaired (or left unrepaired). The model can also include other effects, such as module output degradation over time or disruptions such as electrical grid outages. In addition, PV-RPM is a dynamic probabilistic model that can be used to run many realizations (i.e., possible future outcomes) of a system’s performance using probability distributions to represent uncertain parameter inputs.

  13. Data modelling and performance of data base systems

    International Nuclear Information System (INIS)

    Rossiter, B.N.

    1984-01-01

    The three main methods of data modelling, hierarchical, network, and relational are described together with their advantages and disadvantages. The hierarchical model has strictly limited applicability, but the other two are of general use, although the network model in many respects defines a storage structure whilst the relational model defines a logical structure. Because of this, network systems are more difficult to use than relational systems but are easier to tune to obtain efficient performance. More advanced models have been developed to capture more semantic detail, and two of these RM/T and the role model are discussed. (orig.)

  14. Models used to assess the performance of photovoltaic systems.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua S.; Klise, Geoffrey T.

    2009-12-01

    This report documents the various photovoltaic (PV) performance models and software developed and utilized by researchers at Sandia National Laboratories (SNL) in support of the Photovoltaics and Grid Integration Department. In addition to PV performance models, hybrid system and battery storage models are discussed. A hybrid system using other distributed sources and energy storage can help reduce the variability inherent in PV generation, and due to the complexity of combining multiple generation sources and system loads, these models are invaluable for system design and optimization. Energy storage plays an important role in reducing PV intermittency and battery storage models are used to understand the best configurations and technologies to store PV generated electricity. Other researcher's models used by SNL are discussed including some widely known models that incorporate algorithms developed at SNL. There are other models included in the discussion that are not used by or were not adopted from SNL research but may provide some benefit to researchers working on PV array performance, hybrid system models and energy storage. The paper is organized into three sections to describe the different software models as applied to photovoltaic performance, hybrid systems, and battery storage. For each model, there is a description which includes where to find the model, whether it is currently maintained and any references that may be available. Modeling improvements underway at SNL include quantifying the uncertainty of individual system components, the overall uncertainty in modeled vs. measured results and modeling large PV systems. SNL is also conducting research into the overall reliability of PV systems.

  15. A comparison of single- and multi-site calibration and validation: a case study of SWAT in the Miyun Reservoir watershed, China

    Science.gov (United States)

    Bai, Jianwen; Shen, Zhenyao; Yan, Tiezhu

    2017-09-01

    An essential task in evaluating global water resource and pollution problems is to obtain the optimum set of parameters in hydrological models through calibration and validation. For a large-scale watershed, single-site calibration and validation may ignore spatial heterogeneity and may not meet the needs of the entire watershed. The goal of this study is to apply a multi-site calibration and validation of the Soil andWater Assessment Tool (SWAT), using the observed flow data at three monitoring sites within the Baihe watershed of the Miyun Reservoir watershed, China. Our results indicate that the multi-site calibration parameter values are more reasonable than those obtained from single-site calibrations. These results are mainly due to significant differences in the topographic factors over the large-scale area, human activities and climate variability. The multi-site method involves the division of the large watershed into smaller watersheds, and applying the calibrated parameters of the multi-site calibration to the entire watershed. It was anticipated that this case study could provide experience of multi-site calibration in a large-scale basin, and provide a good foundation for the simulation of other pollutants in followup work in the Miyun Reservoir watershed and other similar large areas.

  16. Theoretical performance model for single image depth from defocus.

    Science.gov (United States)

    Trouvé-Peloux, Pauline; Champagnat, Frédéric; Le Besnerais, Guy; Idier, Jérôme

    2014-12-01

    In this paper we present a performance model for depth estimation using single image depth from defocus (SIDFD). Our model is based on an original expression of the Cramér-Rao bound (CRB) in this context. We show that this model is consistent with the expected behavior of SIDFD. We then study the influence on the performance of the optical parameters of a conventional camera such as the focal length, the aperture, and the position of the in-focus plane (IFP). We derive an approximate analytical expression of the CRB away from the IFP, and we propose an interpretation of the SIDFD performance in this domain. Finally, we illustrate the predictive capacity of our performance model on experimental data comparing several settings of a consumer camera.

  17. Modeling the Performance of Fast Mulipole Method on HPC platforms

    KAUST Repository

    Ibeid, Huda

    2012-01-01

    In this thesis , we discuss the challenges for FMM on current parallel computers and future exasclae architecture. Furthermore, we develop a novel performance model for FMM. Our ultimate aim of this thesis

  18. Integrated Main Propulsion System Performance Reconstruction Process/Models

    Science.gov (United States)

    Lopez, Eduardo; Elliott, Katie; Snell, Steven; Evans, Michael

    2013-01-01

    The Integrated Main Propulsion System (MPS) Performance Reconstruction process provides the MPS post-flight data files needed for postflight reporting to the project integration management and key customers to verify flight performance. This process/model was used as the baseline for the currently ongoing Space Launch System (SLS) work. The process utilizes several methodologies, including multiple software programs, to model integrated propulsion system performance through space shuttle ascent. It is used to evaluate integrated propulsion systems, including propellant tanks, feed systems, rocket engine, and pressurization systems performance throughout ascent based on flight pressure and temperature data. The latest revision incorporates new methods based on main engine power balance model updates to model higher mixture ratio operation at lower engine power levels.

  19. Individualized Next-Generation Biomathematical Modeling of Fatigue and Performance

    National Research Council Canada - National Science Library

    Van Dongen, Hans P

    2006-01-01

    .... This project employed a cutting-edge technique called Bayesian forecasting to develop a novel biomathematical performance model to predict responses to sleep loss and circadian displacement for individual subjects...

  20. Computational Modeling of Human Multiple-Task Performance

    National Research Council Canada - National Science Library

    Kieras, David E; Meyer, David

    2005-01-01

    This is the final report for a project that was a continuation of an earlier, long-term project on the development and validation of the EPIC cognitive architecture for modeling human cognition and performance...

  1. Thermal Model Predictions of Advanced Stirling Radioisotope Generator Performance

    Science.gov (United States)

    Wang, Xiao-Yen J.; Fabanich, William Anthony; Schmitz, Paul C.

    2014-01-01

    This presentation describes the capabilities of three-dimensional thermal power model of advanced stirling radioisotope generator (ASRG). The performance of the ASRG is presented for different scenario, such as Venus flyby with or without the auxiliary cooling system.

  2. ASSESSING INDIVIDUAL PERFORMANCE ON INFORMATION TECHNOLOGY ADOPTION: A NEW MODEL

    OpenAIRE

    Diah Hari Suryaningrum

    2012-01-01

    This paper aims to propose a new model in assessing individual performance on information technology adoption. The new model to assess individual performance was derived from two different theories: decomposed theory of planned behavior and task-technology fit theory. Although many researchers have tried to expand these theories, some of their efforts might lack of theoretical assumptions. To overcome this problem and enhance the coherence of the integration, I used a theory from social scien...

  3. Model of service-oriented catering supply chain performance evaluation

    OpenAIRE

    Gou, Juanqiong; Shen, Guguan; Chai, Rui

    2013-01-01

    Purpose: The aim of this paper is constructing a performance evaluation model for service-oriented catering supply chain. Design/methodology/approach: With the research on the current situation of catering industry, this paper summarized the characters of the catering supply chain, and then presents the service-oriented catering supply chain model based on the platform of logistics and information. At last, the fuzzy AHP method is used to evaluate the performance of service-oriented catering ...

  4. Rising to the challenge : A model of contest performance

    OpenAIRE

    DesAutels, Philip; Berthon, Pierre; Salehi-Sangari, Esmail

    2011-01-01

    Contests are a ubiquitous form of promotion widely adopted by financial services advertisers, yet, paradoxically, academic research on them is conspicuous in its absence. This work addresses this gap by developing a model of contest engagement and performance. Using motivation theory, factors that drive participant engagement are modeled, and engagement's effect on experience and marketing success of the contest specified. Measures of contest performance, in-contest engagement and post-contes...

  5. A performance model for the communication in fast multipole methods on high-performance computing platforms

    KAUST Repository

    Ibeid, Huda; Yokota, Rio; Keyes, David E.

    2016-01-01

    model and the actual communication time on four high-performance computing (HPC) systems, when latency, bandwidth, network topology, and multicore penalties are all taken into account. To our knowledge, this is the first formal characterization

  6. A Mathematical Model to Improve the Performance of Logistics Network

    Directory of Open Access Journals (Sweden)

    Muhammad Izman Herdiansyah

    2012-01-01

    Full Text Available The role of logistics nowadays is expanding from just providing transportation and warehousing to offering total integrated logistics. To remain competitive in the global market environment, business enterprises need to improve their logistics operations performance. The improvement will be achieved when we can provide a comprehensive analysis and optimize its network performances. In this paper, a mixed integer linier model for optimizing logistics network performance is developed. It provides a single-product multi-period multi-facilities model, as well as the multi-product concept. The problem is modeled in form of a network flow problem with the main objective to minimize total logistics cost. The problem can be solved using commercial linear programming package like CPLEX or LINDO. Even in small case, the solver in Excel may also be used to solve such model.Keywords: logistics network, integrated model, mathematical programming, network optimization

  7. Construction Of A Performance Assessment Model For Zakat Management Institutions

    Directory of Open Access Journals (Sweden)

    Sri Fadilah

    2016-12-01

    Full Text Available The objective of the research is to examine the performance evaluation using Balanced Scorecard model. The research is conducted due to a big gap existing between zakat (alms and religious tax in Islam with its potential earn of as much as 217 trillion rupiahs and the realization of the collected zakat fund that is only reached for three trillion. This indicates that the performance of zakat management organizations in collecting the zakat is still very low. On the other hand, the quantity and the quality of zakat management organizations have to be improved. This means the performance evaluation model as a tool to evaluate performance is needed. The model construct is making a performance evaluation model that can be implemented to zakat management organizations. The organizational performance with Balanced Scorecard evaluation model will be effective if it is supported by three aspects, namely:  PI, BO and TQM. This research uses explanatory method and data analysis tool of SEM/PLS. Data collecting technique are questionnaires, interviews and documentation. The result of this research shows that PI, BO and TQM simultaneously and partially gives a significant effect on organizational performance.

  8. Port performance evaluation tool based on microsimulation model

    Directory of Open Access Journals (Sweden)

    Tsavalista Burhani Jzolanda

    2017-01-01

    Full Text Available As port performance is becoming correlative to national competitiveness, the issue of port performance evaluation has significantly raised. Port performances can simply be indicated by port service levels to the ship (e.g., throughput, waiting for berthing etc., as well as the utilization level of equipment and facilities within a certain period. The performances evaluation then can be used as a tool to develop related policies for improving the port’s performance to be more effective and efficient. However, the evaluation is frequently conducted based on deterministic approach, which hardly captures the nature variations of port parameters. Therefore, this paper presents a stochastic microsimulation model for investigating the impacts of port parameter variations to the port performances. The variations are derived from actual data in order to provide more realistic results. The model is further developed using MATLAB and Simulink based on the queuing theory.

  9. Team performance modeling for HRA in dynamic situations

    International Nuclear Information System (INIS)

    Shu Yufei; Furuta, Kazuo; Kondo, Shunsuke

    2002-01-01

    This paper proposes a team behavior network model that can simulate and analyze response of an operator team to an incident in a dynamic and context-sensitive situation. The model is composed of four sub-models, which describe the context of team performance. They are task model, event model, team model and human-machine interface model. Each operator demonstrates aspects of his/her specific cognitive behavior and interacts with other operators and the environment in order to deal with an incident. Individual human factors, which determine the basis of communication and interaction between individuals, and cognitive process of an operator, such as information acquisition, state-recognition, decision-making and action execution during development of an event scenario are modeled. A case of feed and bleed operation in pressurized water reactor under an emergency situation was studied and the result was compared with an experiment to check the validity of the proposed model

  10. A Model of Statistics Performance Based on Achievement Goal Theory.

    Science.gov (United States)

    Bandalos, Deborah L.; Finney, Sara J.; Geske, Jenenne A.

    2003-01-01

    Tests a model of statistics performance based on achievement goal theory. Both learning and performance goals affected achievement indirectly through study strategies, self-efficacy, and test anxiety. Implications of these findings for teaching and learning statistics are discussed. (Contains 47 references, 3 tables, 3 figures, and 1 appendix.)…

  11. A Model for Effective Performance in the Indonesian Navy.

    Science.gov (United States)

    1987-06-01

    NAVY LEADERSHIP AND MANAGEMENT COM PETENCY M ODEL .................................. 15 D. MCBER COMPETENT MANAGERS MODEL ................ IS E. SU M M... leadership and managerial skills which emphasize on effective performance of the officers in managing the human resources under their cormnand and...supervision. By effective performance we mean officers who not only know about management theories , but who possess the characteristics, knowledge, skill, and

  12. A Composite Model for Employees' Performance Appraisal and Improvement

    Science.gov (United States)

    Manoharan, T. R.; Muralidharan, C.; Deshmukh, S. G.

    2012-01-01

    Purpose: The purpose of this paper is to develop an innovative method of performance appraisal that will be useful for designing a structured training programme. Design/methodology/approach: Employees' performance appraisals are conducted using new approaches, namely data envelopment analysis and an integrated fuzzy model. Interpretive structural…

  13. Performance Implications of Business Model Change: A Case Study

    Directory of Open Access Journals (Sweden)

    Jana Poláková

    2015-01-01

    Full Text Available The paper deals with changes in performance level introduced by the change of business model. The selected case is a small family business undergoing through substantial changes in reflection of structural changes of its markets. The authors used the concept of business model to describe value creation processes within the selected family business and by contrasting the differences between value creation processes before and after the change introduced they prove the role of business model as the performance differentiator. This is illustrated with the use of business model canvas constructed on the basis interviews, observations and document analysis. The two business model canvases allow for explanation of cause-and-effect relationships within the business leading to change in performance. The change in the performance is assessed by financial analysis of the business conducted over the period of 2006–2012 demonstrates changes in performance (comparing development of ROA, ROE and ROS having their lowest levels before the change of business model was introduced, growing after the introduction of the change, as well as the activity indicators with similar developments of the family business. The described case study contributes to the concept of business modeling with the arguments supporting its value as strategic tool facilitating decisions related to value creation within the business.

  14. Enhancing pavement performance prediction models for the Illinois Tollway System

    Directory of Open Access Journals (Sweden)

    Laxmikanth Premkumar

    2016-01-01

    Full Text Available Accurate pavement performance prediction represents an important role in prioritizing future maintenance and rehabilitation needs, and predicting future pavement condition in a pavement management system. The Illinois State Toll Highway Authority (Tollway with over 2000 lane miles of pavement utilizes the condition rating survey (CRS methodology to rate pavement performance. Pavement performance models developed in the past for the Illinois Department of Transportation (IDOT are used by the Tollway to predict the future condition of its network. The model projects future CRS ratings based on pavement type, thickness, traffic, pavement age and current CRS rating. However, with time and inclusion of newer pavement types there was a need to calibrate the existing pavement performance models, as well as, develop models for newer pavement types.This study presents the results of calibrating the existing models, and developing new models for the various pavement types in the Illinois Tollway network. The predicted future condition of the pavements is used in estimating its remaining service life to failure, which is of immediate use in recommending future maintenance and rehabilitation requirements for the network. Keywords: Pavement performance models, Remaining life, Pavement management

  15. Confirming the Value of Swimming-Performance Models for Adolescents.

    Science.gov (United States)

    Dormehl, Shilo J; Robertson, Samuel J; Barker, Alan R; Williams, Craig A

    2017-10-01

    To evaluate the efficacy of existing performance models to assess the progression of male and female adolescent swimmers through a quantitative and qualitative mixed-methods approach. Fourteen published models were tested using retrospective data from an independent sample of Dutch junior national-level swimmers from when they were 12-18 y of age (n = 13). The degree of association by Pearson correlations was compared between the calculated differences from the models and quadratic functions derived from the Dutch junior national qualifying times. Swimmers were grouped based on their differences from the models and compared with their swimming histories that were extracted from questionnaires and follow-up interviews. Correlations of the deviations from both the models and quadratic functions derived from the Dutch qualifying times were all significant except for the 100-m breaststroke and butterfly and the 200-m freestyle for females (P motivation appeared to be synonymous with higher-level career performance. This mixed-methods approach helped confirm the validity of the models that were found to be applicable to adolescent swimmers at all levels, allowing coaches to track performance and set goals. The value of the models in being able to account for the expected performance gains during adolescence enables quantification of peripheral factors that could affect performance.

  16. How motivation affects academic performance: a structural equation modelling analysis.

    Science.gov (United States)

    Kusurkar, R A; Ten Cate, Th J; Vos, C M P; Westers, P; Croiset, G

    2013-03-01

    Few studies in medical education have studied effect of quality of motivation on performance. Self-Determination Theory based on quality of motivation differentiates between Autonomous Motivation (AM) that originates within an individual and Controlled Motivation (CM) that originates from external sources. To determine whether Relative Autonomous Motivation (RAM, a measure of the balance between AM and CM) affects academic performance through good study strategy and higher study effort and compare this model between subgroups: males and females; students selected via two different systems namely qualitative and weighted lottery selection. Data on motivation, study strategy and effort was collected from 383 medical students of VU University Medical Center Amsterdam and their academic performance results were obtained from the student administration. Structural Equation Modelling analysis technique was used to test a hypothesized model in which high RAM would positively affect Good Study Strategy (GSS) and study effort, which in turn would positively affect academic performance in the form of grade point averages. This model fit well with the data, Chi square = 1.095, df = 3, p = 0.778, RMSEA model fit = 0.000. This model also fitted well for all tested subgroups of students. Differences were found in the strength of relationships between the variables for the different subgroups as expected. In conclusion, RAM positively correlated with academic performance through deep strategy towards study and higher study effort. This model seems valid in medical education in subgroups such as males, females, students selected by qualitative and weighted lottery selection.

  17. Enhancing pavement performance prediction models for the Illinois Tollway System

    OpenAIRE

    Laxmikanth Premkumar; William R. Vavrik

    2016-01-01

    Accurate pavement performance prediction represents an important role in prioritizing future maintenance and rehabilitation needs, and predicting future pavement condition in a pavement management system. The Illinois State Toll Highway Authority (Tollway) with over 2000 lane miles of pavement utilizes the condition rating survey (CRS) methodology to rate pavement performance. Pavement performance models developed in the past for the Illinois Department of Transportation (IDOT) are used by th...

  18. Comparative assessment of PV plant performance models considering climate effects

    DEFF Research Database (Denmark)

    Tina, Giuseppe; Ventura, Cristina; Sera, Dezso

    2017-01-01

    . The methodological approach is based on comparative tests of the analyzed models applied to two PV plants installed respectively in north of Denmark (Aalborg) and in the south of Italy (Agrigento). The different ambient, operating and installation conditions allow to understand how these factors impact the precision...... the performance of the studied PV plants with others, the efficiency of the systems has been estimated by both conventional Performance Ratio and Corrected Performance Ratio...

  19. Performing arts medicine: A research model for South Africa

    Directory of Open Access Journals (Sweden)

    Karendra Devroop

    2014-11-01

    Full Text Available Performing Arts Medicine has developed into a highly specialised field over the past three decades. The Performing Arts Medical Association (PAMA has been the leading proponent of this unique and innovative field with ground-breaking research studies, symposia, conferences and journals dedicated specifically to the medical problems of performing artists. Similar to sports medicine, performing arts medicine caters specifically for the medical problems of performing artists including musicians and dancers. In South Africa there is a tremendous lack of knowledge of the field and unlike our international counterparts, we do not have specialised clinical settings that cater for the medical problems of performing artists. There is also a tremendous lack of research on performance-related medical problems of performing artists in South Africa. Accordingly the purpose of this paper is to present an overview of the field of performing arts medicine, highlight some of the significant findings from recent research studies and present a model for conducting research into the field of performing arts medicine. It is hoped that this research model will lead to increased research on the medical problems of performing artists in South Africa.

  20. The Social Responsibility Performance Outcomes Model: Building Socially Responsible Companies through Performance Improvement Outcomes.

    Science.gov (United States)

    Hatcher, Tim

    2000-01-01

    Considers the role of performance improvement professionals and human resources development professionals in helping organizations realize the ethical and financial power of corporate social responsibility. Explains the social responsibility performance outcomes model, which incorporates the concepts of societal needs and outcomes. (LRW)