WorldWideScience

Sample records for modeling runoff generation

  1. Modelling monthly runoff generation processes following land use changes: groundwater–surface runoff interactions

    Directory of Open Access Journals (Sweden)

    M. Bari

    2004-01-01

    Full Text Available A conceptual water balance model is presented to represent changes in monthly water balance following land use changes. Monthly rainfall–runoff, groundwater and soil moisture data from four experimental catchments in Western Australia have been analysed. Two of these catchments, 'Ernies' (control, fully forested and 'Lemon' (54% cleared are in a zone of mean annual rainfall of 725 mm, while 'Salmon' (control, fully forested and 'Wights' (100% cleared are in a zone with mean annual rainfall of 1125 mm. At the Salmon forested control catchment, streamflow comprises surface runoff, base flow and interflow components. In the Wights catchment, cleared of native forest for pasture development, all three components increased, groundwater levels rose significantly and stream zone saturated area increased from 1% to 15% of the catchment area. It took seven years after clearing for the rainfall–runoff generation process to stabilise in 1984. At the Ernies forested control catchment, the permanent groundwater system is 20 m below the stream bed and so does not contribute to streamflow. Following partial clearing of forest in the Lemon catchment, groundwater rose steadily and reached the stream bed by 1987. The streamflow increased in two phases: (i immediately after clearing due to reduced evapotranspiration, and (ii through an increase in the groundwater-induced stream zone saturated area after 1987. After analysing all the data available, a conceptual monthly model was created, comprising four inter-connecting stores: (i an upper zone unsaturated store, (ii a transient stream zone store, (ii a lower zone unsaturated store and (iv a saturated groundwater store. Data such as rooting depth, Leaf Area Index, soil porosity, profile thickness, depth to groundwater, stream length and surface slope were incorporated into the model as a priori defined attributes. The catchment average values for different stores were determined through matching observed and

  2. Modelling monthly runoff generation processes following land use changes: groundwater-surface runoff interactions

    Science.gov (United States)

    Bari, M.; Smettem, K. R. J.

    A conceptual water balance model is presented to represent changes in monthly water balance following land use changes. Monthly rainfall-runoff, groundwater and soil moisture data from four experimental catchments in Western Australia have been analysed. Two of these catchments, "Ernies" (control, fully forested) and "Lemon" (54% cleared) are in a zone of mean annual rainfall of 725 mm, while "Salmon" (control, fully forested) and "Wights" (100% cleared) are in a zone with mean annual rainfall of 1125 mm. At the Salmon forested control catchment, streamflow comprises surface runoff, base flow and interflow components. In the Wights catchment, cleared of native forest for pasture development, all three components increased, groundwater levels rose significantly and stream zone saturated area increased from 1% to 15% of the catchment area. It took seven years after clearing for the rainfall-runoff generation process to stabilise in 1984. At the Ernies forested control catchment, the permanent groundwater system is 20 m below the stream bed and so does not contribute to streamflow. Following partial clearing of forest in the Lemon catchment, groundwater rose steadily and reached the stream bed by 1987. The streamflow increased in two phases: (i) immediately after clearing due to reduced evapotranspiration, and (ii) through an increase in the groundwater-induced stream zone saturated area after 1987. After analysing all the data available, a conceptual monthly model was created, comprising four inter-connecting stores: (i) an upper zone unsaturated store, (ii) a transient stream zone store, (ii) a lower zone unsaturated store and (iv) a saturated groundwater store. Data such as rooting depth, Leaf Area Index, soil porosity, profile thickness, depth to groundwater, stream length and surface slope were incorporated into the model as a priori defined attributes. The catchment average values for different stores were determined through matching observed and predicted

  3. A simple topography-driven, calibration-free runoff generation model

    Science.gov (United States)

    Gao, H.; Birkel, C.; Hrachowitz, M.; Tetzlaff, D.; Soulsby, C.; Savenije, H. H. G.

    2017-12-01

    Determining the amount of runoff generation from rainfall occupies a central place in rainfall-runoff modelling. Moreover, reading landscapes and developing calibration-free runoff generation models that adequately reflect land surface heterogeneities remains the focus of much hydrological research. In this study, we created a new method to estimate runoff generation - HAND-based Storage Capacity curve (HSC) which uses a topographic index (HAND, Height Above the Nearest Drainage) to identify hydrological similarity and partially the saturated areas of catchments. We then coupled the HSC model with the Mass Curve Technique (MCT) method to estimate root zone storage capacity (SuMax), and obtained the calibration-free runoff generation model HSC-MCT. Both the two models (HSC and HSC-MCT) allow us to estimate runoff generation and simultaneously visualize the spatial dynamic of saturated area. We tested the two models in the data-rich Bruntland Burn (BB) experimental catchment in Scotland with an unusual time series of the field-mapped saturation area extent. The models were subsequently tested in 323 MOPEX (Model Parameter Estimation Experiment) catchments in the United States. HBV and TOPMODEL were used as benchmarks. We found that the HSC performed better in reproducing the spatio-temporal pattern of the observed saturated areas in the BB catchment compared with TOPMODEL which is based on the topographic wetness index (TWI). The HSC also outperformed HBV and TOPMODEL in the MOPEX catchments for both calibration and validation. Despite having no calibrated parameters, the HSC-MCT model also performed comparably well with the calibrated HBV and TOPMODEL, highlighting the robustness of the HSC model to both describe the spatial distribution of the root zone storage capacity and the efficiency of the MCT method to estimate the SuMax. Moreover, the HSC-MCT model facilitated effective visualization of the saturated area, which has the potential to be used for broader

  4. Application of random number generators in genetic algorithms to improve rainfall-runoff modelling

    Science.gov (United States)

    Chlumecký, Martin; Buchtele, Josef; Richta, Karel

    2017-10-01

    The efficient calibration of rainfall-runoff models is a difficult issue, even for experienced hydrologists. Therefore, fast and high-quality model calibration is a valuable improvement. This paper describes a novel methodology and software for the optimisation of a rainfall-runoff modelling using a genetic algorithm (GA) with a newly prepared concept of a random number generator (HRNG), which is the core of the optimisation. The GA estimates model parameters using evolutionary principles, which requires a quality number generator. The new HRNG generates random numbers based on hydrological information and it provides better numbers compared to pure software generators. The GA enhances the model calibration very well and the goal is to optimise the calibration of the model with a minimum of user interaction. This article focuses on improving the internal structure of the GA, which is shielded from the user. The results that we obtained indicate that the HRNG provides a stable trend in the output quality of the model, despite various configurations of the GA. In contrast to previous research, the HRNG speeds up the calibration of the model and offers an improvement of rainfall-runoff modelling.

  5. Application of random number generators in genetic algorithms to improve rainfall-runoff modelling

    Czech Academy of Sciences Publication Activity Database

    Chlumecký, M.; Buchtele, Josef; Richta, K.

    2017-01-01

    Roč. 553, October (2017), s. 350-355 ISSN 0022-1694 Institutional support: RVO:67985874 Keywords : genetic algorithm * optimisation * rainfall-runoff modeling * random generator Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Hydrology Impact factor: 3.483, year: 2016 https://ac.els-cdn.com/S0022169417305516/1-s2.0-S0022169417305516-main.pdf?_tid=fa1bad8a-bd6a-11e7-8567-00000aab0f27&acdnat=1509365462_a1335d3d997e9eab19e23b1eee977705

  6. Application of random number generators in genetic algorithms to improve rainfall-runoff modelling

    Czech Academy of Sciences Publication Activity Database

    Chlumecký, M.; Buchtele, Josef; Richta, K.

    2017-01-01

    Roč. 553, October (2017), s. 350-355 ISSN 0022-1694 Institutional support: RVO:67985874 Keywords : genetic algorithm * optimisation * rainfall-runoff modeling * random generator Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Hydrology Impact factor: 3.483, year: 2016 https://ac.els- cdn .com/S0022169417305516/1-s2.0-S0022169417305516-main.pdf?_tid=fa1bad8a-bd6a-11e7-8567-00000aab0f27& amp ;acdnat=1509365462_a1335d3d997e9eab19e23b1eee977705

  7. The response of runoff generation to urban development: modelling and understanding

    Science.gov (United States)

    Guan, Mingfu; Sillanpää, Nora; Koivusalo, Harri

    2014-05-01

    The urbanisation process strongly changes natural catchment by increasing the impervious coverage and by creating a need for efficient drainage systems, resulting in a significant change of catchment hydrology from extreme floods to low flows. Thus, it is becoming important to quantify the impacts of urbanisation on runoff generation and to investigate the possibility of restoring pre-development flows in urban catchments for integrated urban stormwater management. Urban hydrological modelling emphasising on urbanisation effects has received substantial attention. However, the lack of good quality monitoring data in a same developing catchment limits model calibration for many of previous studies. In this concern, this study aims to describe and better understand the effects of urbanisation on catchment hydrology through modelling of a series of scenarios in a developing urban catchment of Saunalahdenranta (SR). The catchment is located at Espoo, southern Finland and has an area of about 13.2 ha. The catchment was developed rapidly from a rural area to a residential area during 2001-2006. Hydrological data were measured in two minutes intervals during the development period, when the imperviousness of the catchment changed from 1.5% to 37%. Precipitation-runoff relationship is simulated using the Stormwater Management Model (SWMM) that is firstly parameterised, calibrated, and validated for the scenario of highly developed residential catchment in 2006. The hydrological impacts of spatial resolution and model parameters, such as the delineation of subcatchment, flow width as well as Manning's roughness are evaluated and discussed. The calibrated model is then used to investigate, how the hydrological response to urbanisation was changing in the scenarios for the previous years (2001-2005) with different levels of urban development (represented by impervious surfaces). The predictions for the several scenarios provide a quantification of the hydrological impacts of

  8. Use of satellite-derived data for characterization of snow cover and simulation of snowmelt runoff through a distributed physically based model of runoff generation

    Directory of Open Access Journals (Sweden)

    L. S. Kuchment

    2010-02-01

    Full Text Available A technique of using satellite-derived data for constructing continuous snow characteristics fields for distributed snowmelt runoff simulation is presented. The satellite-derived data and the available ground-based meteorological measurements are incorporated in a physically based snowpack model. The snowpack model describes temporal changes of the snow depth, density and water equivalent (SWE, accounting for snow melt, sublimation, refreezing melt water and snow metamorphism processes with a special focus on forest cover effects. The remote sensing data used in the model consist of products include the daily maps of snow covered area (SCA and SWE derived from observations of MODIS and AMSR-E instruments onboard Terra and Aqua satellites as well as available maps of land surface temperature, surface albedo, land cover classes and tree cover fraction. The model was first calibrated against available ground-based snow measurements and then applied to calculate the spatial distribution of snow characteristics using satellite data and interpolated ground-based meteorological data. The satellite-derived SWE data were used for assigning initial conditions and the SCA data were used for control of snow cover simulation. The simulated spatial distributions of snow characteristics were incorporated in a distributed physically based model of runoff generation to calculate snowmelt runoff hydrographs. The presented technique was applied to a study area of approximately 200 000 km2 including the Vyatka River basin with catchment area of 124 000 km2. The correspondence of simulated and observed hydrographs in the Vyatka River are considered as an indicator of the accuracy of constructed fields of snow characteristics and as a measure of effectiveness of utilizing satellite-derived SWE data for runoff simulation.

  9. Examining runoff generation processes in the Selke catchment in central Germany: Insights from data and semi-distributed numerical model

    Directory of Open Access Journals (Sweden)

    Sumit Sinha

    2016-09-01

    New hydrological insights for the region: We examined the spatio-temporal variation of runoff generating mechanisms on the sub-basin level on seasonal basis. Our analysis reveals that the runoff generation in the Selke catchment is primarily dominated by shallow sub-surface flow and very rarely the contribution from Dunne overland flow exceeds sub-surface flow. Runoff generated by Hortonian mechanism is very infrequent and almost negligible. We also examined the spatio-temporal variation of runoff coefficients on seasonal basis as well as for individual storms. Due to higher precipitation and topographic relief in the upland catchment of Silberhutte, the runoff coefficients were consistently higher and its peak was found in winter months due to lower evapotranspiration.

  10. 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.

  11. Bayesian estimation of extreme flood quantiles using a rainfall-runoff model and a stochastic daily rainfall generator

    Science.gov (United States)

    Costa, Veber; Fernandes, Wilson

    2017-11-01

    Extreme flood estimation has been a key research topic in hydrological sciences. Reliable estimates of such events are necessary as structures for flood conveyance are continuously evolving in size and complexity and, as a result, their failure-associated hazards become more and more pronounced. Due to this fact, several estimation techniques intended to improve flood frequency analysis and reducing uncertainty in extreme quantile estimation have been addressed in the literature in the last decades. In this paper, we develop a Bayesian framework for the indirect estimation of extreme flood quantiles from rainfall-runoff models. In the proposed approach, an ensemble of long daily rainfall series is simulated with a stochastic generator, which models extreme rainfall amounts with an upper-bounded distribution function, namely, the 4-parameter lognormal model. The rationale behind the generation model is that physical limits for rainfall amounts, and consequently for floods, exist and, by imposing an appropriate upper bound for the probabilistic model, more plausible estimates can be obtained for those rainfall quantiles with very low exceedance probabilities. Daily rainfall time series are converted into streamflows by routing each realization of the synthetic ensemble through a conceptual hydrologic model, the Rio Grande rainfall-runoff model. Calibration of parameters is performed through a nonlinear regression model, by means of the specification of a statistical model for the residuals that is able to accommodate autocorrelation, heteroscedasticity and nonnormality. By combining the outlined steps in a Bayesian structure of analysis, one is able to properly summarize the resulting uncertainty and estimating more accurate credible intervals for a set of flood quantiles of interest. The method for extreme flood indirect estimation was applied to the American river catchment, at the Folsom dam, in the state of California, USA. Results show that most floods

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

    Science.gov (United States)

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

    2016-01-01

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

  13. Modelling surface run-off and trends analysis over India

    Indian Academy of Sciences (India)

    responsible for run-off generation plays a major role in run-off modelling at region scales. Remote sensing, GIS and advancement of the computer technology based evaluation of land surface prop- erties at spatial and temporal scales are very useful input data for hydrological models. Using remote sensing data is not only ...

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

    DEFF Research Database (Denmark)

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

    2005-01-01

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

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

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  16. An Overview of Rainfall-Runoff Model Types

    Science.gov (United States)

    This report explores rainfall-runoff models, their generation methods, and the categories under which they fall. Runoff plays an important role in the hydrological cycle by returning excess precipitation to the oceans and controlling how much water flows into stream systems. Mode...

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

    Science.gov (United States)

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

    2017-07-01

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

  18. Feedbacks Between Shallow Groundwater Dynamics and Surface Topography on Runoff Generation in Flat Fields

    Science.gov (United States)

    Appels, Willemijn M.; Bogaart, Patrick W.; van der Zee, Sjoerd E. A. T. M.

    2017-12-01

    In winter, saturation excess (SE) ponding is observed regularly in temperate lowland regions. Surface runoff dynamics are controlled by small topographical features that are unaccounted for in hydrological models. To better understand storage and routing effects of small-scale topography and their interaction with shallow groundwater under SE conditions, we developed a model of reduced complexity to investigate SE runoff generation, emphasizing feedbacks between shallow groundwater dynamics and mesotopography. The dynamic specific yield affected unsaturated zone water storage, causing rapid switches between negative and positive head and a flatter groundwater mound than predicted by analytical agrohydrological models. Accordingly, saturated areas were larger and local groundwater fluxes smaller than predicted, leading to surface runoff generation. Mesotopographic features routed water over larger distances, providing a feedback mechanism that amplified changes to the shape of the groundwater mound. This in turn enhanced runoff generation, but whether it also resulted in runoff events depended on the geometry and location of the depressions. Whereas conditions favorable to runoff generation may abound during winter, these feedbacks profoundly reduce the predictability of SE runoff: statistically identical rainfall series may result in completely different runoff generation. The model results indicate that waterlogged areas in any given rainfall event are larger than those predicted by current analytical groundwater models used for drainage design. This change in the groundwater mound extent has implications for crop growth and damage assessments.

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

    Science.gov (United States)

    Van Beusekom, Ashley; Viger, Roland

    2016-01-01

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

  20. Modeling Ballasted Tracks for Runoff Coefficient C

    Science.gov (United States)

    2012-08-01

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

  1. Climatic impacts on the runoff generation processes in British Columbia, Canada

    Directory of Open Access Journals (Sweden)

    A. Loukas

    2002-01-01

    Full Text Available The potential impact of future climate change on runoff generation processes in two southern British Columbia catchments was explored using the Canadian Centre for Climate Modelling Analysis General Circulation Model (CGCMa1 to estimate future changes in precipitation, temperature and cloud cover while the U.B.C. Watershed Model was used to simulate discharges and quantify the separate runoff components, i.e. rainfall, snowmelt, glacier melt and groundwater. Changes, not only in precipitation and temperature but also in the spatial distribution of precipitation with elevation, cloud cover, glacier extension, altitude distribution of vegetation, vegetation biomass production and plant physiology were considered. The future climate of the catchments would be wetter and warmer than the present. In the maritime rain-fed catchment of the Upper Campbell, runoff from rainfall is the most significant source of flow for present and future climatic conditions in the autumn and winter whereas runoff from groundwater generates the flow in spring and summer, especially for the future climate scenario. The total runoff, under the future climatic conditions, would increase in the autumn and winter and decrease in spring and summer. In contrast, in the interior snow-covered Illecillewaet catchment, groundwater is the most significant runoff generation mechanism in the autumn and winter although, at present, significant flow is generated from snowmelt in spring and from glacier runoff in summer. In the future scenario, the contribution to flow from snowmelt would increase in winter and diminish in spring while the runoff from the glacier would remain unchanged; groundwater would then become the most significant source of runoff, which would peak earlier in the season. Keywords: climatic change, hydrological simulation, rainfall, snowmelt, runoff processes

  2. EVALUATION OF RAINFALL-RUNOFF MODELS FOR MEDITERRANEAN SUBCATCHMENTS

    Directory of Open Access Journals (Sweden)

    A. Cilek

    2016-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Chien-ming Chou

    2014-01-01

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

  4. Precipitation-runoff modeling system; user's manual

    Science.gov (United States)

    Leavesley, G.H.; Lichty, R.W.; Troutman, B.M.; Saindon, L.G.

    1983-01-01

    The concepts, structure, theoretical development, and data requirements of the precipitation-runoff modeling system (PRMS) are described. The precipitation-runoff modeling system is a modular-design, deterministic, distributed-parameter modeling system developed to evaluate the impacts of various combinations of precipitation, climate, and land use on streamflow, sediment yields, and general basin hydrology. Basin response to normal and extreme rainfall and snowmelt can be simulated to evaluate changes in water balance relationships, flow regimes, flood peaks and volumes, soil-water relationships, sediment yields, and groundwater recharge. Parameter-optimization and sensitivity analysis capabilites are provided to fit selected model parameters and evaluate their individual and joint effects on model output. The modular design provides a flexible framework for continued model system enhancement and hydrologic modeling research and development. (Author 's abstract)

  5. A new field method to characterise the runoff generation potential of burned hillslopes

    Science.gov (United States)

    Sheridan, Gary; Lane, Patrick; Langhans, Christoph

    2016-04-01

    The prediction of post fire runoff generation is critical for the estimation of post fire erosion processes and rates. Typical field measures for determining infiltration model parameters include ring infiltrometers, tension infiltrometers, rainfall simulators and natural runoff plots. However predicting the runoff generating potential of post-fire hillslopes is difficult due to the high spatial variability of soil properties relative to the size of the measurement method, the poorly understood relationship between water repellence and runoff generation, known scaling issues with all the above hydraulic measurements, and logistical limitations for measurements in remote environments. In this study we tested a new field method for characterizing surface runoff generation potential that overcomes these limitations and is quick, simple and cheap to apply in the field. The new field method involves the manual application of a 40mm depth of Brilliant Blue FCF food dye along a 10cm wide and 5m long transect along the contour under slightly-ponded conditions. After 24 hours the transect is excavated to a depth of 10cm and the percentage dyed area within the soil profile recorded manually. The dyed area is an index of infiltration potential of the soil during intense rainfall events, and captures both spatial variability and water repellence effects. The dye measurements were made adjacent to long term instrumented post fire rainfall-runoff plots on 7 contrasting soil types over a 6 month period, and the results show surprisingly strong correlations (r2 = 0.9) between the runoff-ratio from the plots and the dyed area. The results are used to develop an initial conceptual model that links the dye index with an infiltration model and parameters suited to burnt hillslopes. The capacity of this method to provide a simple, and reliable indicator of post fire runoff potential from different fire severities, soil types and treatments is explored in this presentation.

  6. How does imperviousness develop and affect runoff generation in an urbanizing watershed?

    Directory of Open Access Journals (Sweden)

    Gerald Krebs

    2013-08-01

    Full Text Available Imperviousness associated with urbanization remains one of the biggest challenges in sustainable urban design. The replacement of forests, marshlands, buffers, and wetlands with impervious surfaces, strongly influences hydrological processes in urbanizing areas. This study analyzed the contribution of four constructed surfaces types – roofs, yards, roads, and an international airport – to surface runoff within a 21 km2 watershed, and presents the development over five decades (1977−2030. The land-cover model, used to assess watershed imperviousness in 2030, utilized coefficients between impervious areas generating surface runoff and the floor area, developed during the study. The conducted imperviousness analysis allowed the evaluation of land-use development impacts on the stream network, and the identification of hydrologically active areas for urban planning and stormwater management. Research revealed the importance of yard imperviousness related to suburban residential housing for stormwater runoff generation, and the impacts of transport-related imperviousness on stormwater runoff.

  7. Century-scale variability in global annual runoff examined using a water balance model

    Science.gov (United States)

    McCabe, G.J.; Wolock, D.M.

    2011-01-01

    A monthly water balance model (WB model) is used with CRUTS2.1 monthly temperature and precipitation data to generate time series of monthly runoff for all land areas of the globe for the period 1905 through 2002. Even though annual precipitation accounts for most of the temporal and spatial variability in annual runoff, increases in temperature have had an increasingly negative effect on annual runoff after 1980. Although the effects of increasing temperature on runoff became more apparent after 1980, the relative magnitude of these effects are small compared to the effects of precipitation on global runoff. ?? 2010 Royal Meteorological Society.

  8. Designing hybrid grass genomes to control runoff generation

    Science.gov (United States)

    MacLeod, C.; Binley, A.; Humphreys, M.; King, I. P.; O'Donovan, S.; Papadopoulos, A.; Turner, L. B.; Watts, C.; Whalley, W. R.; Haygarth, P.

    2010-12-01

    Sustainable management of water in landscapes requires balancing demands of agricultural production whilst moderating downstream effects like flooding. Pasture comprises 69% of global agricultural areas and is essential for producing food and fibre alongside environmental goods and services. Thus there is a need to breed forage grasses that deliver multiple benefits through increased levels of productivity whilst moderating fluxes of water. Here we show that a novel grass hybrid that combines the entire genomes of perennial ryegrass (Lolium perenne - the grass of choice for Europe’s forage agriculture) and meadow fescue (Festuca pratensis) has a significant role in flood prevention. Field plot experiments established differences in runoff generation with the hybrid cultivar reducing runoff by 50% compared to perennial ryegrass cultivar, and by 35% compared to a meadow fescue cultivar (34 events over two years, replicated randomized-block design, statistically significant differences). This important research outcome was the result of a project that combined plant genetics, soil physics and plot scale hydrology to identify novel grass genotypes that can reduce runoff from grassland systems. Through a coordinated series of experiments examining effects from the gene to plot scale, we have identified that the rapid growth and then turnover of roots in the L. perenne x F. pratensis hybrid is likely to be a key mechanism in reducing runoff generation. More broadly this is an exciting first step to realizing the potential to design grass genomes to achieve both food production, and to deliver flood control, a key ecosystem service.

  9. Incorporating agricultural land cover in conceptual rainfall runoff models

    Science.gov (United States)

    Euser, Tanja; Hrachowitz, Markus; Winsemius, Hessel; Savenije, Hubert

    2015-04-01

    Incorporating spatially variable information is a frequently discussed option to increase the performance of (semi) distributed conceptual rainfall runoff models. One of the methods to do this is by using these spatially variable information to delineate Hydrological Response Units (HRUs) within a catchment. This study tests whether the incorporation of an additional agricultural HRU in a conceptual hydrological model can better reflect the spatial differences in runoff generation and therefore improve the simulation of the wetting phase in autumn. The study area is the meso-scale Ourthe catchment in Belgium. A previous study in this area showed that spatial patterns in runoff generation were already better represented by incorporation of a wetland and a hillslope HRU, compared to a lumped model structure. The influences which are considered by including an agriculture HRU are increased drainage speed due to roads, plough pans and increased infiltration excess overland flow (drainage pipes area only limited present), and variable vegetation patterns due to sowing and harvesting. In addition, the vegetation is not modelled as a static resistance towards evaporation, but the Jarvis stress functions are used to increase the realism of the modelled transpiration; in land-surface models the Jarvis stress functions are already often used for modelling transpiration. The results show that an agricultural conceptualisation in addition to wetland and hillslope conceptualisations leads to small improvements in the modelled discharge. However, the influence is larger on the representation of spatial patterns and the modelled contributions of different HRUs to the total discharge.

  10. Modeling Present and Future River Runoff Using Global Atmospheric Models

    Science.gov (United States)

    1992-10-01

    AD-A265 274 October 1992 TBESIS Modeling Present and Future River Runoff Using Global Atmospheric Models Captain Scott C. Van Blarcum AFIT Student... ATMOSPHERIC MODELS BY SCOTT C. VAN BLARCUM A thesis submitted to the Graduate School-New Brunswick Rutgers, The State University of New Jersey in...03 020 I1UIlU1ll ABSTRACT OF THE THESIS Modeling Present and Future River Runoff Using Global Atmospheric Models by SCOTT C. VAN BLARCUM Thesis

  11. Evaluation of Surface Runoff Generation Processes Using a Rainfall Simulator: A Small Scale Laboratory Experiment

    Science.gov (United States)

    Danáčová, Michaela; Valent, Peter; Výleta, Roman

    2017-12-01

    Nowadays, rainfall simulators are being used by many researchers in field or laboratory experiments. The main objective of most of these experiments is to better understand the underlying runoff generation processes, and to use the results in the process of calibration and validation of hydrological models. Many research groups have assembled their own rainfall simulators, which comply with their understanding of rainfall processes, and the requirements of their experiments. Most often, the existing rainfall simulators differ mainly in the size of the irrigated area, and the way they generate rain drops. They can be characterized by the accuracy, with which they produce a rainfall of a given intensity, the size of the irrigated area, and the rain drop generating mechanism. Rainfall simulation experiments can provide valuable information about the genesis of surface runoff, infiltration of water into soil and rainfall erodibility. Apart from the impact of physical properties of soil, its moisture and compaction on the generation of surface runoff and the amount of eroded particles, some studies also investigate the impact of vegetation cover of the whole area of interest. In this study, the rainfall simulator was used to simulate the impact of the slope gradient of the irrigated area on the amount of generated runoff and sediment yield. In order to eliminate the impact of external factors and to improve the reproducibility of the initial conditions, the experiments were conducted in laboratory conditions. The laboratory experiments were carried out using a commercial rainfall simulator, which was connected to an external peristaltic pump. The pump maintained a constant and adjustable inflow of water, which enabled to overcome the maximum volume of simulated precipitation of 2.3 l, given by the construction of the rainfall simulator, while maintaining constant characteristics of the simulated precipitation. In this study a 12-minute rainfall with a constant intensity

  12. Analyzing runoff processes through conceptual hydrological modeling in the Upper Blue Nile Basin, Ethiopia

    Science.gov (United States)

    Dessie, M.; Verhoest, N. E. C.; Pauwels, V. R. N.; Admasu, T.; Poesen, J.; Adgo, E.; Deckers, J.; Nyssen, J.

    2014-12-01

    Understanding runoff processes in a basin is of paramount importance for the effective planning and management of water resources, in particular in data-scarce regions such as the Upper Blue Nile. Hydrological models representing the underlying hydrological processes can predict river discharges from ungauged catchments and allow for an understanding of the rainfall-runoff processes in those catchments. In this paper, such a conceptual process-based hydrological model is developed and applied to the upper Gumara and Gilgel Abay catchments (both located within the Upper Blue Nile Basin, the Lake Tana sub-basin) to study the runoff mechanisms and rainfall-runoff processes in the basin. Topography is considered as a proxy for the variability of most of the catchment characteristics. We divided the catchments into different runoff production areas using topographic criteria. Impermeable surfaces (rock outcrops and hard soil pans, common in the Upper Blue Nile Basin) were considered separately in the conceptual model. Based on model results, it can be inferred that about 65% of the runoff appears in the form of interflow in the Gumara study catchment, and baseflow constitutes the larger proportion of runoff (44-48%) in the Gilgel Abay catchment. Direct runoff represents a smaller fraction of the runoff in both catchments (18-19% for the Gumara, and 20% for the Gilgel Abay) and most of this direct runoff is generated through infiltration excess runoff mechanism from the impermeable rocks or hard soil pans. The study reveals that the hillslopes are recharge areas (sources of interflow and deep percolation) and direct runoff as saturated excess flow prevails from the flat slope areas. Overall, the model study suggests that identifying the catchments into different runoff production areas based on topography and including the impermeable rocky areas separately in the modeling process mimics the rainfall-runoff process in the Upper Blue Nile Basin well and yields a useful

  13. Analyzing runoff processes through conceptual hydrological modelling in the Upper Blue Nile basin, Ethiopia

    Science.gov (United States)

    Dessie, M.; Verhoest, N. E. C.; Pauwels, V. R. N.; Admasu, T.; Poesen, J.; Adgo, E.; Deckers, J.; Nyssen, J.

    2014-05-01

    Understanding runoff processes in a basin is of paramount importance for the effective planning and management of water resources, in particular in data scarce regions of the Upper Blue Nile. Hydrological models representing the underlying hydrological processes can predict river discharges from ungauged catchments and allow for an understanding of the rainfall-runoff processes in those catchments. In this paper, such a conceptual process-based hydrological model is developed and applied to the upper Gumara and Gilgel Abay catchments (both located within the Upper Blue Nile basin, the Lake Tana sub-basin) to study the runoff mechanisms and rainfall-runoff processes in the basin. Topography is considered as a proxy for the variability of most of the catchment characteristics. We divided the catchments into different runoff production areas using topographic criteria. Impermeable surfaces (rock outcrops and hard soil pans, common in the Upper Blue Nile basin) were considered separately in the conceptual model. Based on model results, it can be inferred that about 65% of the runoff appears in the form of interflow in the Gumara study catchment, and baseflow constitutes the larger proportion of runoff (44-48%) in the Gilgel Abay catchment. Direct runoff represents a smaller fraction of the runoff in both catchments (18-19% for the Gumara, and 20% for the Gilgel Abay) and most of this direct runoff is generated through infiltration excess runoff mechanism from the impermeable rocks or hard soil pans. The study reveals that the hillslopes are recharge areas (sources of interflow and deep percolation) and direct runoff as saturated excess flow prevails from the flat slope areas. Overall, the model study suggests that identifying the catchments into different runoff production areas based on topography and including the impermeable rocky areas separately in the modeling process mimics well the rainfall-runoff process in the Upper Blue Nile basin and brings a useful result

  14. An urban runoff model designed to inform stormwater management decisions.

    Science.gov (United States)

    Beck, Nicole G; Conley, Gary; Kanner, Lisa; Mathias, Margaret

    2017-05-15

    We present an urban runoff model designed for stormwater managers to quantify runoff reduction benefits of mitigation actions that has lower input data and user expertise requirements than most commonly used models. The stormwater tool to estimate load reductions (TELR) employs a semi-distributed approach, where landscape characteristics and process representation are spatially-lumped within urban catchments on the order of 100 acres (40 ha). Hydrologic computations use a set of metrics that describe a 30-year rainfall distribution, combined with well-tested algorithms for rainfall-runoff transformation and routing to generate average annual runoff estimates for each catchment. User inputs include the locations and specifications for a range of structural best management practice (BMP) types. The model was tested in a set of urban catchments within the Lake Tahoe Basin of California, USA, where modeled annual flows matched that of the observed flows within 18% relative error for 5 of the 6 catchments and had good regional performance for a suite of performance metrics. Comparisons with continuous simulation models showed an average of 3% difference from TELR predicted runoff for a range of hypothetical urban catchments. The model usually identified the dominant BMP outflow components within 5% relative error of event-based measured flow data and simulated the correct proportionality between outflow components. TELR has been implemented as a web-based platform for use by municipal stormwater managers to inform prioritization, report program benefits and meet regulatory reporting requirements (www.swtelr.com). Copyright © 2017. Published by Elsevier Ltd.

  15. Wildcat5 for Windows, a rainfall-runoff hydrograph model: user manual and documentation

    Science.gov (United States)

    R. H. Hawkins; A. Barreto-Munoz

    2016-01-01

    Wildcat5 for Windows (Wildcat5) is an interactive Windows Excel-based software package designed to assist watershed specialists in analyzing rainfall runoff events to predict peak flow and runoff volumes generated by single-event rainstorms for a variety of watershed soil and vegetation conditions. Model inputs are: (1) rainstorm characteristics, (2) parameters related...

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

    Science.gov (United States)

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

    2016-04-01

    Surface runoff acts as an integrated response of catchment characteristics and hydrological processes. In the Eastern Mediterranean region, a lack of runoff data has hindered a better understanding of runoff generation processes on the catchment scale, despite the importance of surface runoff as a water resource or flood hazard. Our main aim was to identify and explain differences in catchment runoff reactions across a variety of scales. Over a period of five years, we observed runoff in ephemeral streams of seven watersheds with sizes between 3 and 129 km2. Landuse and surface cover types (share of vegetation, bare soil and rock outcrops) were derived from aerial images by objective classification techniques. Using data from a dense rainfall network we analysed the effects of scale, catchment properties and aridity on runoff generation. Thereby we extracted rainfall and corresponding runoff events from our time-series to calculate event based rainfall characteristics and catchment runoff coefficients. Soil moisture observations provided additional information on antecedent moisture conditions, infiltration characteristics and the evolution of saturated areas. In contrast to the prevailing opinion that the proportion of Hortonian overland flow increases with aridity, we found that in our area the largest share (> 95 %) of runoff is generated by saturation excess overland flow in response to long lasting, rainfall events of high amount. This was supported by a strong correlation between event runoff and precipitation totals. Similar rainfall thresholds (50 mm) for runoff generation were observed in all investigated catchments. No scale effects on runoff coefficients were found; instead we identified up to three-fold runoff coefficients in catchments with larger extension of arid areas, higher percentage of rock outcrops and urbanization. Comparing two headwater catchments with noticeable differences in extent of olive orchards, no difference in runoff generation was

  17. Evaluation of Synthetic Outlet Runoff Assessment Models | Adib ...

    African Journals Online (AJOL)

    Quantitative understanding and prediction of the processes of runoff generation and its transmission to the outlet represent one of the most basic and challenging areas of hydrology. Traditional techniques for design flood estimation use historical rainfall-runoff data for unit hydrograph (UH) derivation. Such techniques have ...

  18. Pollutant runoff from non-point sources and its estimation by runoff models.

    Science.gov (United States)

    Noguchi, M; Hiwatashi, T; Mizuno, Y; Minematsu, M

    2002-01-01

    In order to attain a sound and sustainable water environment, it is important to carry out the environmental management of the watershed. For this purpose, knowledge on the pollutant runoff mechanism from non-point sources becomes very important especially under rainy conditions. At Isahaya, Nagasaki, Japan, a big project of construction of sea-dyke and reclamation is now going on, so reducing the pollutant runoff, especially from non-point sources, becomes more important. Some runoff models of rainwater are developed to predict the rate of pollutant loads from the non-point sources, and their results are compared with each other to investigate the accuracy of prediction. In this paper, runoff analysis of both rainwater and pollutants has been carried out using three models: the tank model, the kinematic wave (K-W) model, and a model using the digital elevation model (DEM). For precise estimation, it becomes necessary to identify the parameters included in these models. Here, total nitrogen has been considered as pollutants, and detachment rates are evaluated, correlated with a class of land use, soil type, and moisture content. Finally, it has been shown that pollutant runoff from non-point sources can be predicted fairly well, identifying the model parameter appropriately.

  19. Fractured Bedrock Storm Flow: a New Pathway for Runoff Generation

    Science.gov (United States)

    Oshun, J.; Salve, R.; Rempe, D. M.; Dietrich, W. E.; Fung, I.

    2010-12-01

    Groundwater dynamics in the fractured weathered bedrock underlying hillslopes may dominate storm runoff in many hilly and mountainous areas Few studies, however, have explored this runoff generation process. Here we use an intensively monitored site to study the spatial relationships between fractured bedrock and hydraulic properties in the weathered zone below a forested hillslope. The study site, Rivendell, is a 4000 m2 catchment draining directly into Elder Creek in the Angelo Coast Range Reserve (ACRR) in Northern California. The site is underlain by highly fractured and weak mudstones and boudinaged, ridge-forming sandstones that are turbidite sequences of the Coastal Franciscan Belt. The site receives an average of 1800mm of precipitation annually, with the vast majority falling between October and May. Rivendell has a thinly mantled soil layer underlain by a fractured rock zone, which thickens upslope to a depth of up to 30 m. Standard penetration tests show a consistent increase in bedrock resistance at depth before an abrupt lower boundary upon which the water table is perched. We use seven monitoring wells, precipitation data, soil moisture data, a steam gauge in Elder Creek, and well pump tests to characterize water movement through the fractured rock zone.. We analyze the lag time between peak rainfall and peak response at seven wells and Elder Creek from 2007-2010. The water table varies across the slope between 4 and 25 m below the ground surface, and the dynamic range of well water level increases with distance from Elder Creek. The magnitude and timing of well response shows a relationship to depth, magnitude of rainfall and antecedent moisture conditions. Although nearly all runoff is generated through fractured bedrock, we observe that Elder Creek consistently shows the shortest lag times compared to the wells on the hillslope. Wells show different trends in magnitude and timing of response throughout the rainy season. Pump tests reveal a

  20. Development of rainfall-runoff forecast model | Oyebode | Journal of ...

    African Journals Online (AJOL)

    This study developed a neurofuzzy-based rainfall-runoff forecast model for river basin and evaluated the performance of the model. This was with a view to capturing the behaviour of hydrological and meterological variables involved in rainfall-runoff process to improve forecast accuracy of rainfallrunoff. Three hydrological ...

  1. MODELING OF STORM WATER RUNOFF FROM GREEN ROOFS

    Directory of Open Access Journals (Sweden)

    Ewa Burszta-Adamiak

    2014-10-01

    Full Text Available Apart from direct measurements, modelling of runoff from green roofs is valuable source of information about effectiveness of this type of structure from hydrological point of view. Among different type of models, the most frequently used are numerical models. They allow to assess the impact of green roofs on decrease and attenuation of runoff, reduction of peak runoff and value of water retention. This paper presents preliminary results of research on computing the rate of runoff from green roofs using GARDENIA model. The analysis has been carried out for selected rainfall events registered during measuring campaign on pilot-scale green roofs. Obtained results are promising and show good fit between observed and simulated runoff.

  2. Runoff modeling of the Mara River using satellite observed soil ...

    African Journals Online (AJOL)

    The model is developed based on the relationships found between satellite observed soil moisture and rainfall and the measured runoff. It uses the satellite observed rainfall as the prime forcing, and the soil moisture to separate the fast surface runoff and slow base flow contributions. The soil moisture and rainfall products ...

  3. Mathematical modeling of rainwater runoff over catchment surface ...

    African Journals Online (AJOL)

    Mathematical modeling of rainwater runoff over catchment surface and mass transfer of contaminant incoming to water stream from soil. ... rainwater runoff along the surface catchment taking account the transport of pollution which permeates into the water flow from a porous media of soil at the certain areas of this surface.

  4. Evaluation of Synthetic Outlet Runoff Assessment Models 1ARASH ...

    African Journals Online (AJOL)

    Michael Horsfall

    error in peak (PEP), and 3-percentage error in time to peak (PETP). The results reveal the accuracy and applicability of these synthetic models for derivation of runoff hydrograph. @ JASEM. Estimation of runoff response from ungauged catchments has been an important subject of research for planning, development and ...

  5. Runoff modeling of the Mara River using Satellite Observed Soil ...

    African Journals Online (AJOL)

    ecosystem, famous for the scenic large scale seasonal wildebeest migration. In the south-western ... MATERIALS AND METHODS. 2.1. In-situ measurements. Runoff data was utilized for validation and calibration of the soil moisture-runoff model. The data was obtained for Mara ... In this study we apply a modified version of ...

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

    Directory of Open Access Journals (Sweden)

    Rafael Pires Fernandes

    2013-12-01

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

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

    Science.gov (United States)

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

    2013-11-01

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

  8. Surface runoff in flat terrain: How field topography and runoff generating processes control hydrological connectivity

    NARCIS (Netherlands)

    Appels, W.M.; Bogaart, P.W.; Bogaart, P.W.; Zee, van der S.E.A.T.M.

    2016-01-01

    In flat lowland agricultural catchments in temperate climate zones with highly permeable sandy soils, surface runoff is a rare process with a large impact on the redistribution of sediments and solutes and stream water quality. We examine hydrological data obtained on two field sites in the

  9. Revisiting Runoff Model Calibration: Airborne Snow Observatory Results Allow Improved Modeling Results

    Science.gov (United States)

    McGurk, B. J.; Painter, T. H.

    2014-12-01

    Deterministic snow accumulation and ablation simulation models are widely used by runoff managers throughout the world to predict runoff quantities and timing. Model fitting is typically based on matching modeled runoff volumes and timing with observed flow time series at a few points in the basin. In recent decades, sparse networks of point measurements of the mountain snowpacks have been available to compare with modeled snowpack, but the comparability of results from a snow sensor or course to model polygons of 5 to 50 sq. km is suspect. However, snowpack extent, depth, and derived snow water equivalent have been produced by the NASA/JPL Airborne Snow Observatory (ASO) mission for spring of 20013 and 2014 in the Tuolumne River basin above Hetch Hetchy Reservoir. These high-resolution snowpack data have exposed the weakness in a model calibration based on runoff alone. The U.S. Geological Survey's Precipitation Runoff Modeling System (PRMS) calibration that was based on 30-years of inflow to Hetch Hetchy produces reasonable inflow results, but modeled spatial snowpack location and water quantity diverged significantly from the weekly measurements made by ASO during the two ablation seasons. The reason is that the PRMS model has many flow paths, storages, and water transfer equations, and a calibrated outflow time series can be right for many wrong reasons. The addition of a detailed knowledge of snow extent and water content constrains the model so that it is a better representation of the actual watershed hydrology. The mechanics of recalibrating PRMS to the ASO measurements will be described, and comparisons in observed versus modeled flow for both a small subbasin and the entire Hetch Hetchy basin will be shown. The recalibrated model provided a bitter fit to the snowmelt recession, a key factor for water managers as they balance declining inflows with demand for power generation and ecosystem releases during the final months of snow melt runoff.

  10. Application of GIS in Modeling Zilberchai Basin Runoff

    Science.gov (United States)

    Malekani, L.; Khaleghi, S.; Mahmoodi, M.

    2014-10-01

    Runoff is one of most important hydrological variables that are used in many civil works, planning for optimal use of reservoirs, organizing rivers and warning flood. The runoff curve number (CN) is a key factor in determining runoff in the SCS (Soil Conservation Service) based hydrologic modeling method. The traditional SCS-CN method for calculating the composite curve number consumes a major portion of the hydrologic modeling time. Therefore, geographic information systems (GIS) are now being used in combination with the SCS-CN method. This work uses a methodology of determining surface runoff by Geographic Information System model and applying SCS-CN method that needs the necessary parameters such as land use map, hydrologic soil groups, rainfall data, DEM, physiographic characteristic of the basin. The model is built by implementing some well known hydrologic methods in GIS like as ArcHydro, ArcCN-Runoff for modeling of Zilberchai basin runoff. The results show that the high average weighted of curve number indicate that permeability of the basin is low and therefore likelihood of flooding is high. So the fundamental works is essential in order to increase water infiltration in Zilberchai basin and to avoid wasting surface water resources. Also comparing the results of the computed and observed runoff value show that use of GIS tools in addition to accelerate the calculation of the runoff also increase the accuracy of the results. This paper clearly demonstrates that the integration of GIS with the SCS-CN method provides a powerful tool for estimating runoff volumes in large basins.

  11. Land Cover Influence on Wet Season Storm Runoff Generation and Hydrologic Flowpaths in Central Panama

    Science.gov (United States)

    Birch, A. L.; Stallard, R. F.; Barnard, H. R.

    2017-12-01

    While relationships between land use/land cover and hydrology are well studied and understood in temperate parts of the world, little research exists in the humid tropics, where hydrologic research is often decades behind. Specifically, quantitative information on how physical and biological differences across varying land covers influence runoff generation and hydrologic flowpaths in the humid tropics is scarce; frequently leading to poorly informed hydrologic modelling and water policy decision making. This research effort seeks to quantify how tropical land cover change may alter physical hydrologic processes in the economically important Panama Canal Watershed (Republic of Panama) by separating streamflow into its different runoff components using end member mixing analysis. The samples collected for this project come from small headwater catchments of four varying land covers (mature tropical forest, young secondary forest, active pasture, recently clear-cut tropical forest) within the Smithsonian Tropical Research Institute's Agua Salud Project. During the past three years, samples have been collected at the four study catchments from streamflow and from a number of water sources within hillslope transects, and have been analyzed for stable water isotopes, major cations, and major anions. Major ion analysis of these samples has shown distinct geochemical differences for the potential runoff generating end members sampled (soil moisture/ preferential flow, groundwater, overland flow, throughfall, and precipitation). Based on this finding, an effort was made from May-August 2017 to intensively sample streamflow during wet season storm events, yielding a total of 5 events of varying intensity in each land cover/catchment, with sampling intensity ranging from sub-hourly to sub-daily. The focus of this poster presentation will be to present the result of hydrograph separation's done using end member mixing analysis from this May-August 2017 storm dataset. Expected

  12. Effective precipitation duration for runoff peaks based on catchment modelling

    Science.gov (United States)

    Sikorska, A. E.; Viviroli, D.; Seibert, J.

    2018-01-01

    Despite precipitation intensities may greatly vary during one flood event, detailed information about these intensities may not be required to accurately simulate floods with a hydrological model which rather reacts to cumulative precipitation sums. This raises two questions: to which extent is it important to preserve sub-daily precipitation intensities and how long does it effectively rain from the hydrological point of view? Both questions might seem straightforward to answer with a direct analysis of past precipitation events but require some arbitrary choices regarding the length of a precipitation event. To avoid these arbitrary decisions, here we present an alternative approach to characterize the effective length of precipitation event which is based on runoff simulations with respect to large floods. More precisely, we quantify the fraction of a day over which the daily precipitation has to be distributed to faithfully reproduce the large annual and seasonal floods which were generated by the hourly precipitation rate time series. New precipitation time series were generated by first aggregating the hourly observed data into daily totals and then evenly distributing them over sub-daily periods (n hours). These simulated time series were used as input to a hydrological bucket-type model and the resulting runoff flood peaks were compared to those obtained when using the original precipitation time series. We define then the effective daily precipitation duration as the number of hours n, for which the largest peaks are simulated best. For nine mesoscale Swiss catchments this effective daily precipitation duration was about half a day, which indicates that detailed information on precipitation intensities is not necessarily required to accurately estimate peaks of the largest annual and seasonal floods. These findings support the use of simple disaggregation approaches to make usage of past daily precipitation observations or daily precipitation simulations

  13. A pesticide runoff model for simulating runoff losses of pesticides from agricultural lands.

    Science.gov (United States)

    Li, Y R; Huang, G H; Li, Y F; Struger, J; Fischer, J D

    2003-01-01

    An integrated modeling system was developed to predict runoff losses of pesticides from agricultural lands. The system is an integration of a mathematical model, a database system, and a geographic information system. Information on soil type, land use, land slope, watershed boundaries, precipitation, pesticide usage, as well as physical and chemical properties of pesticides have been input to a GIS, managed through a database, and used for further modeling studies. The modeling outputs were in turn put into the database, such that runoff patterns along with pesticides losses could be further simulated by using a database management system. The final results could then be visualized through GIS. The developed modeling system was applied to the Kintore Creek Watershed, Ontario, Canada, for simulating losses of atrazine from agricultural lands. A water quality monitoring project was carried out from 1988 to 1992 in the watershed to detect conditions of surface water pollution due to the use of pesticides. The modeling outputs were verified through the monitoring data, demonstrating reasonable prediction accuracy. The result indicated that the model provides an effective means for forecasting pesticide runoff from agriculture lands.

  14. Effects of antecedent soil moisture on runoff modeling in small semiarid watersheds of southeastern Arizona

    Directory of Open Access Journals (Sweden)

    Y. Zhang

    2011-10-01

    Full Text Available This study presents unique data on the effects of antecedent soil moisture on runoff generation in a semi-arid environment, with implications for process-based modeling of runoff. The data were collected from four small watersheds measured continuously from 2002 through 2010 in an environment where evapo-transpiration approaches 100% of the infiltrated water on the hillslopes. Storm events were generally intense and of short duration, and antecedent volumetric moisture conditions were dry, with an average in the upper 5 cm soil layer over the nine year period of 8% and a standard deviation of 3%. Sensitivity analysis of the model showed an average of 0.05 mm change in runoff for each 1% change in soil moisture, indicating an approximate 0.15 mm average variation in runoff accounted for by the 3% standard deviation of measured antecedent soil moisture. This compared to a standard deviation of 4.7 mm in the runoff depths for the measured events. Thus the low variability of soil moisture in this environment accounts for a relative lack of importance of storm antecedent soil moisture for modeling the runoff. Runoff characteristics simulated with a nine year average of antecedent soil moisture were statistically identical to those simulated with measured antecedent soil moisture, indicating that long term average antecedent soil moisture could be used as a substitute for measured antecedent soil moisture for runoff modeling of these watersheds. We also found no significant correlations between measured runoff ratio and antecedent soil moisture in any of the four watersheds.

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

    Directory of Open Access Journals (Sweden)

    Campos-Aranda Daniel Francisco

    2014-10-01

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

  16. Predicting the Impacts of Rural Catchment Changes on Runoff Generation and Flooding

    Science.gov (United States)

    Enda O'Connell, P.; Ewen, John; O'Donnell, Greg

    2010-05-01

    While urbanization is widely associated with changes to the runoff generation and flooding regimes of catchments worldwide, the rural landscape has also undergone major changes. Over the past fifty years, much of the European landscape has been transformed as a result of changes in land use and management. The growth in intensive agriculture and associated farming practices have changed natural hydrological functioning at the field/hillslope scale, and as a consequence, flood generation mechanisms at the catchment scale may have been affected. In the UK, there is evidence that soil compaction/degradation has created local scale flooding problems, but it is not clear how flood generation at larger catchment scales may have been affected. A wide range of interventions associated with farming and land use management (e.g. land drainage etc) complicate the overall picture. Similar problems have been observed ad documented in other European countries, and there is the added concern about how the catchments will respond to the more extreme rainfall regimes expected under climate change. There is also frequent controversy over the impacts of afforestation and deforestation in the uplands on lowland floods, particularly in Asia. There is a pressing need for modelling tools that can provide predictions of the impacts of anthropogenic interventions, whether urban or rural, on the downstream flooding regimes of catchments. Central to the prediction problem is the scale issue: how do local scale changes to runoff generation propagate to larger catchment scales and create impacts? An integrated programme of multiscale catchment experimentation and modelling is being undertaken in the UK to gain a better understanding of how small scale changes in runoff generation propagate to larger catchment scales, and to support decision-making on flood risk mitigation. New modelling tools have been developed which can be used to assess impacts and guide management interventions. The first

  17. Investigation of runoff generation from anthropogenic sources with dissolved xenobiotics

    Science.gov (United States)

    Krein, A.; Pailler, J.; Guignard, C.; Iffly, J.; Pfister, L.; Hoffmann, L.

    2009-04-01

    In the experimental Mess basin (35 km2, Luxembourg) dissolved xenobiotics in surface water are used to study the influences of anthropogenic sources like separated sewer systems on runoff generation. Emerging contaminants like pharmaceuticals are of growing interest because of their use in large quantities in human and veterinary medicine. The amounts reaching surface waters depend on rainfall patterns, hydraulic conditions, consumption, metabolism, degradation, and disposal. The behaviour of endocrine disruptors including pharmaceuticals in the aquatic environment is widely unknown. The twelve molecules analyzed belong to three families: the estrogens, the antibiotics (sulfonamides, tetracyclines), and the painkillers (ibuprofen, diclofenac). Xenobiotics can be used as potential environmental tracers for untreated sewerage. Our results show that the concentrations are highly variable during flood events. The highest concentrations are reached in the first flush period, mainly during the rising limb of the flood hydrographs. As a result of the kinematic wave effect the concentration peak occurs in some cases a few hours after the discharge maximum. In floodwater (eleven floods, 66 samples) the highest concentrations were measured for ibuprofen (g/l range), estrone, and diclofenac (all ng/l range). From the tetracycline group, essentially tetracycline itself is of relevance, while the sulfonamides are mainly represented by sulfamethoxazole (all in ng/l range). In the Mess River the pharmaceuticals fluxes during flood events proved to be influenced by hydrological conditions. Different pharmaceuticals showed their concentration peaks during different times of a flood event. An example is the estrone peak that - during summer flash floods - often occurred one to two hours prior to the largest concentrations of the painkillers. This suggests for more sources than the sole storm drainage through the spillway of the single sewage water treatment plant, different

  18. Ephemeral and intermittent runoff generation processes in a low relief, highly weathered catchment

    Science.gov (United States)

    Zimmer, Margaret A.; McGlynn, Brian L.

    2017-08-01

    Most field-based approaches that address runoff generation questions have been conducted in steep landscapes with shallow soils. Runoff generation processes in low relief landscapes with deep soils remain less understood. We addressed this by characterizing dominant runoff generating flow paths by monitoring the timing and magnitude of precipitation, runoff, shallow soil moisture, and shallow and deep groundwater dynamics in a 3.3 ha ephemeral-to-intermittent drainage network in the Piedmont region of North Carolina, USA. This Piedmont region is gently sloped with highly weathered soils characterized by shallow impeding layers due to decreases in saturated hydraulic conductivity with depth. Our results indicated two dominant catchment storage states driven by seasonal evapotranspiration. Within these states, distinct flow paths were activated, resulting in divergent hydrograph recessions. Groundwater dynamics during precipitation events with different input characteristics and contrasting storage states showed distinct shallow and deep groundwater flow path behavior could produce similar runoff magnitudes. During an event with low antecedent storage, activation of a shallow, perched, transient water table dominated runoff production. During an event with high antecedent storage, the deeper water table activated shallow flow paths by rising into the shallow transmissive soil horizons. Despite these differing processes, the relationship between active surface drainage length (ASDL) and runoff was consistent. Hysteretic behavior between ASDL and runoff suggested that while seasonal ASDLs can be predicted based on runoff, the mechanisms and source areas producing flow can be highly variable and not easily estimated from runoff alone. These processes and flow paths have significant implications for stream chemistry across seasons and storage states.

  19. A coupled weather generator - rainfall-runoff approach on hourly time steps for flood risk analysis

    Science.gov (United States)

    Winter, Benjamin; Schneeberger, Klaus; Dung Nguyen, Viet; Vorogushyn, Sergiy; Huttenlau, Matthias; Merz, Bruno; Stötter, Johann

    2017-04-01

    The evaluation of potential monetary damage of flooding is an essential part of flood risk management. One possibility to estimate the monetary risk is to analyze long time series of observed flood events and their corresponding damages. In reality, however, only few flood events are documented. This limitation can be overcome by the generation of a set of synthetic, physically and spatial plausible flood events and subsequently the estimation of the resulting monetary damages. In the present work, a set of synthetic flood events is generated by a continuous rainfall-runoff simulation in combination with a coupled weather generator and temporal disaggregation procedure for the study area of Vorarlberg (Austria). Most flood risk studies focus on daily time steps, however, the mesoscale alpine study area is characterized by short concentration times, leading to large differences between daily mean and daily maximum discharge. Accordingly, an hourly time step is needed for the simulations. The hourly metrological input for the rainfall-runoff model is generated in a two-step approach. A synthetic daily dataset is generated by a multivariate and multisite weather generator and subsequently disaggregated to hourly time steps with a k-Nearest-Neighbor model. Following the event generation procedure, the negative consequences of flooding are analyzed. The corresponding flood damage for each synthetic event is estimated by combining the synthetic discharge at representative points of the river network with a loss probability relation for each community in the study area. The loss probability relation is based on exposure and susceptibility analyses on a single object basis (residential buildings) for certain return periods. For these impact analyses official inundation maps of the study area are used. Finally, by analyzing the total event time series of damages, the expected annual damage or losses associated with a certain probability of occurrence can be estimated for

  20. Runoff Generation Mechanisms and Mean Transit Time in a High-Elevation Tropical Ecosystem

    Science.gov (United States)

    Mosquera, G.

    2015-12-01

    Understanding runoff generation processes in tropical mountainous regions remains poorly understood, particularly in ecosystems above the tree line. Here, we provide insights on the process dominating the ecohydrology of the tropical alpine biome (i.e., páramo) of the Zhurucay River Ecohydrological Observatory. The study site is located in south Ecuador between 3400-3900 m in elevation. We used a nested monitoring system with eight catchments (20-753 ha) to measure hydrometric data since December 2010. Biweekly samples of rainfall, streamflow, and soil water at low tension were collected for three years (May 2011-May2014) and analyzed for water stable isotopes. We conducted an isotopic characterization of rainfall, streamflow, and soil waters to investigate runoff generation. These data were also integrated into a lumped model to estimate the mean transit time (MTT) and to investigate landscape features that control its variability. The isotopic characterization evidenced that the water stored in the shallow organic horizon of the Histosol soils (Andean wetlands) located near the streams is the major contributor of water to the streams year-round, whereas the water draining through the hillslope soils, the Andosols, regulates discharge by recharging the wetlands at the valley bottoms. The MTT evaluation indicated relatively short MTTs (0.15-0.73 yr) linked to short subsurface flow paths of water. We also found evidence for topographic controls on the MTT variability. These results reveal that: 1) the ecohydrology of this ecosystem is dominated by shallow subsurface flow in the organic horizon of the soils and 2) the combination of the high storage capacity of the Andean wetlands and the slope of the catchments controls runoff generation and the high water regulation capacity of the ecosystem.

  1. Uncertainty based modeling of rainfall-runoff: Combined differential evolution adaptive Metropolis (DREAM) and K-means clustering

    Science.gov (United States)

    Zahmatkesh, Zahra; Karamouz, Mohammad; Nazif, Sara

    2015-09-01

    Simulation of rainfall-runoff process in urban areas is of great importance considering the consequences and damages of extreme runoff events and floods. The first issue in flood hazard analysis is rainfall simulation. Large scale climate signals have been proved to be effective in rainfall simulation and prediction. In this study, an integrated scheme is developed for rainfall-runoff modeling considering different sources of uncertainty. This scheme includes three main steps of rainfall forecasting, rainfall-runoff simulation and future runoff prediction. In the first step, data driven models are developed and used to forecast rainfall using large scale climate signals as rainfall predictors. Due to high effect of different sources of uncertainty on the output of hydrologic models, in the second step uncertainty associated with input data, model parameters and model structure is incorporated in rainfall-runoff modeling and simulation. Three rainfall-runoff simulation models are developed for consideration of model conceptual (structural) uncertainty in real time runoff forecasting. To analyze the uncertainty of the model structure, streamflows generated by alternative rainfall-runoff models are combined, through developing a weighting method based on K-means clustering. Model parameters and input uncertainty are investigated using an adaptive Markov Chain Monte Carlo method. Finally, calibrated rainfall-runoff models are driven using the forecasted rainfall to predict future runoff for the watershed. The proposed scheme is employed in the case study of the Bronx River watershed, New York City. Results of uncertainty analysis of rainfall-runoff modeling reveal that simultaneous estimation of model parameters and input uncertainty significantly changes the probability distribution of the model parameters. It is also observed that by combining the outputs of the hydrological models using the proposed clustering scheme, the accuracy of runoff simulation in the

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

    Indian Academy of Sciences (India)

    matical framework based on mass, momentum and energy conservation equations in a spatially dis- tributed model domain, and parameter values that are directly related to ... conceptual black box, or stochastic models. The complex nonlinearity process of rainfall–runoff in southern Taiwan provides an impetus for evaluat-.

  3. DAILY RAINFALL-RUNOFF MODELLING BY NEURAL NETWORKS ...

    African Journals Online (AJOL)

    K. Benzineb, M. Remaoun

    2016-09-01

    Sep 1, 2016 ... The hydrologic behaviour modelling of w. Journal of Fundamental and Applied Scienc. ISSN 1112-9867. Available online at http://www.jfas.inf. Journal of Fundamental and Applied S. International License. Libraries Resource Directory. We a. INFALL-RUNOFF MODELLING BY NEURAL NETWORKS IN.

  4. Application of two rainfall - runoff models to Kelantan Catchment ...

    African Journals Online (AJOL)

    Rainfall-runoff models can be used for forecasting flow from catchments. Flow forecasting from a catchment has great use for proper water resources development and operational management. Countless models have been produced m different parts of the world to simulate this transformation of rainfall over the catchment ...

  5. Inverse modeling of hydrologic parameters using surface flux and runoff observations in the Community Land Model

    Science.gov (United States)

    Sun, Y.; Hou, Z.; Huang, M.; Tian, F.; Leung, L. Ruby

    2013-12-01

    This study demonstrates the possibility of inverting hydrologic parameters using surface flux and runoff observations in version 4 of the Community Land Model (CLM4). Previous studies showed that surface flux and runoff calculations are sensitive to major hydrologic parameters in CLM4 over different watersheds, and illustrated the necessity and possibility of parameter calibration. Both deterministic least-square fitting and stochastic Markov-chain Monte Carlo (MCMC)-Bayesian inversion approaches are evaluated by applying them to CLM4 at selected sites with different climate and soil conditions. The unknowns to be estimated include surface and subsurface runoff generation parameters and vadose zone soil water parameters. We find that using model parameters calibrated by the sampling-based stochastic inversion approaches provides significant improvements in the model simulations compared to using default CLM4 parameter values, and that as more information comes in, the predictive intervals (ranges of posterior distributions) of the calibrated parameters become narrower. In general, parameters that are identified to be significant through sensitivity analyses and statistical tests are better calibrated than those with weak or nonlinear impacts on flux or runoff observations. Temporal resolution of observations has larger impacts on the results of inverse modeling using heat flux data than runoff data. Soil and vegetation cover have important impacts on parameter sensitivities, leading to different patterns of posterior distributions of parameters at different sites. Overall, the MCMC-Bayesian inversion approach effectively and reliably improves the simulation of CLM under different climates and environmental conditions. Bayesian model averaging of the posterior estimates with different reference acceptance probabilities can smooth the posterior distribution and provide more reliable parameter estimates, but at the expense of wider uncertainty bounds.

  6. Storage Dynamics and Non-Linear Connectivity between Landscape Units Control Runoff Generation and Stream Water Age Distributions

    Science.gov (United States)

    Soulsby, C.; Birkel, C.; Geris, J.; Tetzlaff, D.

    2015-12-01

    We assess the influence of storage dynamics and non-linearities in hydrological connectivity on runoff generation and stream water ages, using a long-term record of daily isotopes in precipitation and stream flow. These were used to test a parsimonious tracer-aided runoff model for a Scottish catchment. The model tracks tracers and the ages of water fluxes through and between conceptual stores representing steeper hillslopes, dynamically saturated riparian peatlands and deeper groundwater (i.e. the main landscape units involved in runoff generation). Storage is largest in groundwater and on the steep hillslopes, though most dynamic mixing occurs in smaller stores in the riparian peat. The model also couples the ecohydrological effects of different vegetation communities in contrasting landscape units, by estimating evaporation, resulting moisture deficits and the ages of evaporated waters, which also affect the generation and age of runoff. Both stream flow and isotope variations are well-captured by the model, and the simulated storage and tracer dynamics in the main landscape units are consistent with independent measurements. The model predicts the mean age of runoff as ~1.8 years. On a daily basis, this varies from ~1 month in storm events, when younger waters draining the riparian peatland dominate, to around 4 years in dry periods, when groundwater sustains flow. Hydrological connectivity between the units varies non-linearly with storage which depends upon antecedent conditions and event characteristics. This, in turn, determines the spatial distribution of flow paths and the integration of their contrasting non-stationary ages. Improving the representation of storage dynamics and quantifying the ages of water fluxes in such models gives a more complete conceptualisation of the importance of the soil water fluxes in critical zone processes and a framework for tracking diffuse pollutants in water quality assessment.

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

    Indian Academy of Sciences (India)

    This study proposes an application of two techniques of artificial intelligence (AI) for rainfall–runoff modeling: the artificial neural networks (ANN) and .... conventional mathematical analysis does not, or cannot, provide analytical solutions, .... very simple where there exist one-to-one relation- ships between the symbols of the ...

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

    Indian Academy of Sciences (India)

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

  9. Tracers Show Ecohydrologic Influences on Runoff Generation Components at the Qinghai-Tibet Plateau

    Science.gov (United States)

    Liu, H.; Liu, J.; Peng, A.; Gu, W.; Wang, W.; Gao, F.

    2017-12-01

    In order to learn more about the critical zone ecohydrological dynamics at the Qinghai-Tibet Plateau, a research on the identification of runoff components using tracers was carried out in the Niyang River upstream, a tributary of the Yalung Zangbo River. In this study, four basins with the areas of 182, 216, 243, 213 km2 which are embed in a larger basin were sampled at altitudes between 3667 to 6140 m. The types of land use in the basins mainly include forest land, grassland and glacier. River water and precipitation were sampled monthly, while spring water, glacial ice, soil, and plants were sampled seasonally. Soil and plant samples were taken along the valleys with spatial interval of about 5 km. Soil and plant waters were extracted via cryogenic vacuum distillation method, and then analyzed for isotopes and ions. Preliminary results show that the δD and δ18O of the precipitation water spread approximately along the LMWL of the Namucuo Lake near Lasa city, which varied according to altitude. Stem water δD and δ18O from different elevations and tree species also varied regularly, albeit with no apparent relationship to recent precipitation. It appears that trees utilized fissure water and soil water formed by precipitation. Future efforts will involve (1) an expanded sampling strategy across basins, and (2) a series of experiments on the Hydrohill catchment in the Chuzhou Experimental Facility, whereby an improved understanding of K+, Na+, Ca2+ and Mg2+ export dynamics could aid in much better description and modeling of Niyang River runoff composition and generation. This research is funded by the NSFC project 91647111 and 91647203, which are included in the Runoff Change and its Adaptive Management in the Major Rivers in Southwestern China Major Research Plan.

  10. Importance of incorporating agriculture in conceptual rainfall-runoff models

    Science.gov (United States)

    de Boer-Euser, Tanja; Hrachowitz, Markus; Winsemius, Hessel; Savenije, Hubert

    2016-04-01

    Incorporating spatially variable information is a frequently discussed option to increase the performance of (semi-)distributed conceptual rainfall-runoff models. One of the methods to do this is by using this spatially variable information to delineate Hydrological Response Units (HRUs) within a catchment. In large parts of Europe the original forested land cover is replaced by an agricultural land cover. This change in land cover probably affects the dominant runoff processes in the area, for example by increasing the Hortonian overland flow component, especially on the flatter and higher elevated parts of the catchment. A change in runoff processes implies a change in HRUs as well. A previous version of our model distinguished wetlands (areas close to the stream) from the remainder of the catchment. However, this configuration was not able to reproduce all fast runoff processes, both in summer as in winter. Therefore, this study tests whether the reproduction of fast runoff processes can be improved by incorporating a HRU which explicitly accounts for the effect of agriculture. A case study is carried out in the Ourthe catchment in Belgium. For this case study the relevance of different process conceptualisations is tested stepwise. Among the conceptualisations are Hortonian overland flow in summer and winter, reduced infiltration capacity due to a partly frozen soil and the relative effect of rainfall and snow smelt in case of this frozen soil. The results show that the named processes can make a large difference on event basis, especially the Hortonian overland flow in summer and the combination of rainfall and snow melt on (partly) frozen soil in winter. However, differences diminish when the modelled period of several years is evaluated based on standard metrics like Nash-Sutcliffe Efficiency. These results emphasise on one hand the importance of incorporating the effects of agricultural in conceptual models and on the other hand the importance of more event

  11. Assessing basin heterogeneities for rainfall-runoff modelling of the Okavango River and its transboundary management

    Science.gov (United States)

    Baumberg, V.; Helmschrot, J.; Steudel, T.; Göhmann, H.; Fischer, C.; Flügel, W.-A.

    2014-09-01

    The neighbouring river systems Cubango and Cuito drain the southeastern part of the Angolan Highlands and form the Okavango River after their confluence, thus providing 95% of the Okavango River discharge. Although they are characterised by similar environmental conditions, runoff records indicate remarkable differences regarding the hydrological dynamics. The Cubango River is known for rapid discharges with high peaks and low baseflow whereas the Cuito runoff appears more balanced. These differences are mainly caused by heterogeneous geological conditions or terrain features. The Cubango headwaters are dominated by crystalline bedrock and steeper, v-shaped valleys while the Cuito system is characterised by wide, swampy valleys and thick sand layers, thus attenuating runoff. This study presents model exercises which have been performed to assess and quantify these effects by applying the distributive model J2000g for each sub-basin. The models provide reasonable results representing the spatio-temporal runoff pattern, although some peaks are over- or underestimated, particularly in the Cuito catchment. This is explained by the scarce information on extent and structure of storages, such as aquifers or swamps, in the Cuito system. However, the model results aid understanding of the differences of both tributaries in runoff generation and underpin the importance of floodplains regarding the control of runoff peaks and low flows in the Cuito system. Model exercises reveal that basin heterogeneity needs to be taken into account and must be parameterised appropriately for reliable modelling and assessment of the entire Okavango River basin for managing the water resources of the transboundary Okavango River in a harmonious way.

  12. Model based monitoring of stormwater runoff quality

    DEFF Research Database (Denmark)

    Birch, Heidi; Vezzaro, Luca; Mikkelsen, Peter Steen

    2012-01-01

    Monitoring of micropollutants (MP) in stormwater is essential to evaluate the impacts of stormwater on the receiving aquatic environment. The aim of this study was to investigate how different strategies for monitoring of stormwater quality (combination of model with field sampling) affect...... the information obtained about MPs discharged from the monitored system. A dynamic stormwater quality model was calibrated using MP data collected by volume-proportional and passive sampling in a storm drainage system in the outskirts of Copenhagen (Denmark) and a 10-year rain series was used to find annual...

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

    Science.gov (United States)

    Achieng, K. O.; Zhu, J.

    2017-12-01

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

  14. Initiation processes for run-off generated debris flows in the Wenchuan earthquake area of China

    NARCIS (Netherlands)

    Hu, W.; Dong, X. J.; Xu, Q.; Wang, G. H.; van Asch, T. W J; Hicher, P. Y.

    2016-01-01

    The frequency of huge debris flows greatly increased in the epicenter area of the Wenchuan earthquake. Field investigation revealed that runoff during rainstorm played a major role in generating debris flows on the loose deposits, left by coseismic debris avalanches. However, the mechanisms of these

  15. Application of remote sensing and geographical information system for generation of runoff curve number

    Science.gov (United States)

    Meshram, S. Gajbhiye; Sharma, S. K.; Tignath, S.

    2017-07-01

    Watershed is an ideal unit for planning and management of land and water resources (Gajbhiye et al., IEEE international conference on advances in technology and engineering (ICATE), Bombay, vol 1, issue 9, pp 23-25, 2013a; Gajbhiye et al., Appl Water Sci 4(1):51-61, 2014a; Gajbhiye et al., J Geol Soc India (SCI-IF 0.596) 84(2):192-196, 2014b). This study aims to generate the curve number, using remote sensing and geographical information system (GIS) and the effect of slope on curve number values. The study was carried out in Kanhaiya Nala watershed located in Satna district of Madhya Pradesh. Soil map, Land Use/Land cover and slope map were generated in GIS Environment. The CN parameter values corresponding to various soil, land cover, and land management conditions were selected from Natural Resource Conservation Service (NRCS) standard table. Curve number (CN) is an index developed by the NRCS, to represent the potential for storm water runoff within a drainage area. The CN for a drainage basin is estimated using a combination of land use, soil, and antecedent soil moisture condition (AMC). In present study effect of slope on CN values were determined. The result showed that the CN unadjusted value are higher in comparison to CN adjusted with slope. Remote sensing and GIS is very reliable technique for the preparation of most of the input data required by the SCS curve number model.

  16. Parameter estimation in stochastic rainfall-runoff models

    DEFF Research Database (Denmark)

    Jonsdottir, Harpa; Madsen, Henrik; Palsson, Olafur Petur

    2006-01-01

    A parameter estimation method for stochastic rainfall-runoff models is presented. The model considered in the paper is a conceptual stochastic model, formulated in continuous-discrete state space form. The model is small and a fully automatic optimization is, therefore, possible for estimating all....... For a comparison the parameters are also estimated by an output error method, where the sum of squared simulation error is minimized. The former methodology is optimal for short-term prediction whereas the latter is optimal for simulations. Hence, depending on the purpose it is possible to select whether...... the parameter values are optimal for simulation or prediction. The data originates from Iceland and the model is designed for Icelandic conditions, including a snow routine for mountainous areas. The model demands only two input data series, precipitation and temperature and one output data series...

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

    Directory of Open Access Journals (Sweden)

    Votrubova Jana

    2017-06-01

    Full Text Available Hydrological monitoring in small headwater catchments provides the basis for examining complex interrelating hydraulic processes that govern the runoff generation. Contributions of different subsurface runoff mechanisms to the catchment discharge formation at two small forested headwater catchments are studied with the help of their natural isotopic signatures. The Uhlirska catchment (Jizera Mts., Czech Republic is situated in headwater area of the Lusatian Neisse River. The catchment includes wetlands at the valley bottom developed over deluviofluvial granitic sediments surrounded by gentle hillslopes with shallow soils underlain by weathered granite. The Liz catchment (Bohemian Forest, Czech Republic is situated in headwater area of the Otava River. It belongs to hillslope-type catchments with narrow riparian zones. The soil at Liz is developed on biotite paragneiss bedrock. The basic comparison of hydrological time series reveals that the event-related stream discharge variations at the Uhlirska catchment are bigger and significantly more frequent than at Liz. The analysis of isotope concentration data revealed different behavior of the two catchments during the major rainfall-runoff events. At Uhlirska, the percentage of the direct runoff formed by the event water reaches its maximum on the falling limb of the hydrograph. At Liz, the event water related fraction of the direct outflow is maximal on the rising limb of the hydrograph and then lowers. The hydraulic functioning of the Uhlirska catchment is determined by communication between hillslope and riparian zone compartments.

  18. Using the snowmelt runoff model to evaluate climate change effects and to compare basin runoff between New Mexico and Idaho.

    Science.gov (United States)

    The Snowmelt Runoff Model(SRM) has been developed and tested in small to large basins worldwide. SRM has been found to be very useful for understanding snowmelt processes as well as for simulating or forecasting snowmelt-derived water supplies. SRM is being used in New Mexico in a NSF-funded EPSCo...

  19. Sensitivity-Based Modeling of Evaluating Surface Runoff and Sediment Load using Digital and Analog Mechanisms

    Directory of Open Access Journals (Sweden)

    Olotu Yahaya

    2014-07-01

    Full Text Available Analyses of runoff- sediment measurement and evaluation using automated and convectional runoff-meters was carried out at Meteorological and Hydrological Station of Auchi Polytechnic, Auchi using two runoff plots (ABCDa and EFGHm of area 2m 2 each, depth 0.26 m and driven into the soil to the depth of 0.13m. Runoff depths and intensities were measured from each of the positioned runoff plot. Automated runoff-meter has a measuring accuracy of ±0.001l/±0.025 mm and rainfall depth-intensity was measured using tipping-bucket rainguage during the period of 14-month of experimentation. Minimum and maximum rainfall depths of 1.2 and 190.3 mm correspond to measured runoff depths (MRo of 0.0 mm for both measurement approaches and 60.4 mm and 48.9 mm respectively. Automated runoffmeter provides precise, accurate and instantaneous result over the convectional measurement of surface runoff. Runoff measuring accuracy for automated runoff-meter from the plot (ABCDa produces R 2 = 0.99; while R 2 = 0.96 for manual evaluation in plot (EFGHm. WEPP and SWAT models were used to simulate the obtained hydrological variables from the applied measurement mechanisms. The outputs of sensitivity simulation analysis indicate that data from automated measuring systems gives a better modelling index and such could be used for running robust runoff-sediment predictive modelling technique under different reservoir sedimentation and water management scenarios.

  20. Runoff Modelling in Urban Storm Drainage by Neural Networks

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Brorsen, Michael; Schaarup-Jensen, Kjeld

    1995-01-01

    network is used to compute flow or water level at selected points in the sewer system, and to forecast the flow from a small residential area. The main advantages of the neural network are the build-in self calibration procedure and high speed performance, but the neural network cannot be used to extract......A neural network is used to simulate folw and water levels in a sewer system. The calibration of th neural network is based on a few measured events and the network is validated against measureed events as well as flow simulated with the MOUSE model (Lindberg and Joergensen, 1986). The neural...... knowledge of the runoff process. The neural network was found to simulate 150 times faster than e.g. the MOUSE model....

  1. The development and evaluation of new runoff parameterization representations coupled with Noah Land Surface Model

    Science.gov (United States)

    Zheng, Z.; Zhang, W.; Xu, J.

    2011-12-01

    As a key component of the global water cycle, runoff plays an important role in earth climate system by affecting the land surface water and energy balance. Realistic runoff parameterization within land surface model (LSM) is significant for accurate land surface modeling and numerical weather and climate prediction. Hence, optimization and refinement of runoff formulation in LSM can further improve model predictive capability of surface-to-atmosphere fluxes which influences the complex interactions between the land surface and atmosphere. Moreover, the performance of runoff simulation in LSM would essential to drought and flood prediction and warning. In this study, a new runoff parameterization named XXT (Xin'anjiang x TOPMODEL) was developed by introducing the water table depth into the soil moisture storage capacity distribution curve (SMSCC) from Xin'anjiang model for surface runoff calculation improvement and then integrating with a TOPMODEL-based groundwater scheme. Several studies had already found a strong correlation between the water table depth and land surface processes. In this runoff parameterization, the dynamic variation of surface and subsurface runoff calculation is connected in a systematic way through the change of water table depth. The XXT runoff parameterization was calibrated and validated with datasets both from observation and Weather Research & Forecasting model (WRF) outputs, the results with high Nash-efficiency coefficient indicated that it has reliable capability of runoff simulation in different climate regions. After model test, the XXT runoff parameterization is coupled with the unified Noah LSM 3.2 instead of simple water balance model (SWB) in order to alleviate the runoff simulating bias which may lead to poor energy partition and evaporation. The impact of XXT is investigated through application of a whole year (1998) simulation at surface flux site of Champaign, Illinois (40.01°N, 88.37°W). The results show that Noah

  2. Runoff generation and routing on artificial slopes in a Mediterranean-continental environment: the Teruel coalfield, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Nicolau, J.M. [Universidad de Alcala de Henares, Alcala de Henares (Spain)

    2002-07-01

    The aim of the study was to identify the mechanisms of runoff generation and routing and their controlling factors at the hillslope scale, on artificial slopes derived from surface coal mining reclamation in a Mediterranean-continental area. Rainfall and runoff at interrill and microcatchment scales were recorded for a year on two slopes with different substrata: topsoil cover and overburden cover. Runoff coefficient and runoff routing from interrill areas to microcatchment outlets were higher in the overburden substratum than in topsoil, and greater in the most developed rill network. Rainfall volume is the major parameter responsible for runoff response on overburden, suggesting that this substratum is very impermeable - at least during the main rainfall periods of the year (late spring and autumn) when the soil surface is sealed. In such conditions, most rainfall input is converted into runoff, regardless of its intensity. Results from artificial rainfall experiments, conducted 3 and 7 years after seeding, confirm the low infiltration capacity of overburden when sealed. The hydrological response shows great seasonal variability on the overburden slope in accordance with soil surface changes over the year. Rainfall volume and intensities explain runoff at the inter-rill scale on the topsoil slope, where rainfall experiments demonstrated a typical Hortonian infiltration curve. However, no correlation was found at the microcatchment level, probably because of the loss of functionality of the only rill as ecological succession proceeded. The runoff generation mechanism on the topsoil slope is more homogeneous throughout the year. The dense rill networks of the overburden slope guarantee very effective runoff drainage, regardless of rainfall magnitude. Runoff generation and routing on topsoil slopes are controlled by grass cover and soil moisture content, whereas on overburden slopes rill network density and soil moisture content are the main controlling factors.

  3. Nutrient Models Developments Using Runoff-Nutrient Relationships in an Agricultural Prairie Basin, Manitoba.

    Science.gov (United States)

    Mahmood, T. H.; Pomeroy, J. W.; Wheater, H. S.; Elliott, J. A.; Baulch, H. M.; Lindenschmidt, K. E.

    2015-12-01

    Nutrient export to streams and lakes from agricultural activities can result in significant deterioration of water quality and aquatic ecosystem health. In Western Canada, particular concerns arise for prairie agricultural systems, which are dominated by the effects of a cold climate. Insufficient attention has been given to understand the links between cold region watershed responses and nutrient concentration and a robust watershed-scale modeling framework is needed to simulate nutrient concentration and loads. Long-term, field observations of nutrient concentration-runoff relationships were used to develop nutrient concentration models for the Tobacco Creek Model Watershed (TCMW) which drains into the Red River basin. Field observations include streamflow concentrations of N and P at multiple scales from two headwater basins. Distinct nutrient concentration-runoff models for snowmelt, rain on snow (ROS) and rainfall runoff processes were developed from observed runoff-nutrient concentration relationships. Snowmelt runoff had a moderately positive correlation with particulate nutrient concentrations but no correlation with that of dissolved nutrients. ROS runoff had a weak relationship with both particulate and dissolved nutrient concentrations. Rainfall runoff had the strongest positive correlation with particulate nutrient concentrations but no association with that of dissolved nutrients. The modeling approach also identified a clear hysteretic behavior in the relationship between runoff and particulate nutrient concentration during the 2013 snowmelt runoff event at the basin outlet gauge. The models provide insight into the hydrological controls on nutrient export from cold regions watersheds and the strong effects of inter-annual climatic variability. Snowmelt runoff is a reliable exporter of large nutrient loads while nutrient export by rainfall runoff exceeded snowmelt runoff during hydrologically wet summers such as 2002, 2005, 2011 and 2013.

  4. RAINFALL-RUNOFF MODELING IN THE TURKEY RIVER USING ...

    African Journals Online (AJOL)

    2015-01-15

    Jan 15, 2015 ... a logical relationship with one and two days ago flow rate and one, two and three days ago rainfall values. ... back propagation artificial neural network (BPANN) to simulate rainfall-runoff process for two sub-basins of ... [6] used ANN and fuzzy logic for predicting event based rainfall runoff and tested these.

  5. Integration of field data into operational snowmelt-runoff models

    International Nuclear Information System (INIS)

    Brandt, M.; Bergström, S.

    1994-01-01

    Conceptual runoff models have become standard tools for operational hydrological forecasting in Scandinavia. These models are normally based on observations from the national climatological networks, but in mountainous areas the stations are few and sometimes not representative. Due to the great economic importance of good hydrological forecasts for the hydro-power industry attempts have been made to improve the model simulations by support from field observations of the snowpack. The snowpack has been mapped by several methods; airborne gamma-spectrometry, airborne georadars, satellites and by conventional snow courses. The studies cover more than ten years of work in Sweden. The conclusion is that field observations of the snow cover have a potential for improvement of the forecasts of inflow to the reservoirs in the mountainous part of the country, where the climatological data coverages is poor. This is pronounced during years with unusual snow distribution. The potential for model improvement is smaller in the climatologically more homogeneous forested lowlands, where the climatological network is denser. The costs of introduction of airborne observations into the modelling procedure are high and can only be justified in areas of great hydropower potential. (author)

  6. Exploring uncertainty and model predictive performance concepts via a modular snowmelt-runoff modeling framework

    Science.gov (United States)

    Tyler Jon Smith; Lucy Amanda. Marshall

    2010-01-01

    Model selection is an extremely important aspect of many hydrologic modeling studies because of the complexity, variability, and uncertainty that surrounds the current understanding of watershed-scale systems. However, development and implementation of a complete precipitation-runoff modeling framework, from model selection to calibration and uncertainty analysis, are...

  7. Subgrid Parameterization of the Soil Moisture Storage Capacity for a Distributed Rainfall-Runoff Model

    Directory of Open Access Journals (Sweden)

    Weijian Guo

    2015-05-01

    Full Text Available Spatial variability plays an important role in nonlinear hydrologic processes. Due to the limitation of computational efficiency and data resolution, subgrid variability is usually assumed to be uniform for most grid-based rainfall-runoff models, which leads to the scale-dependence of model performances. In this paper, the scale effect on the Grid-Xinanjiang model was examined. The bias of the estimation of precipitation, runoff, evapotranspiration and soil moisture at the different grid scales, along with the scale-dependence of the effective parameters, highlights the importance of well representing the subgrid variability. This paper presents a subgrid parameterization method to incorporate the subgrid variability of the soil storage capacity, which is a key variable that controls runoff generation and partitioning in the Grid-Xinanjiang model. In light of the similar spatial pattern and physical basis, the soil storage capacity is correlated with the topographic index, whose spatial distribution can more readily be measured. A beta distribution is introduced to represent the spatial distribution of the soil storage capacity within the grid. The results derived from the Yanduhe Basin show that the proposed subgrid parameterization method can effectively correct the watershed soil storage capacity curve. Compared to the original Grid-Xinanjiang model, the model performances are quite consistent at the different grid scales when the subgrid variability is incorporated. This subgrid parameterization method reduces the recalibration necessity when the Digital Elevation Model (DEM resolution is changed. Moreover, it improves the potential for the application of the distributed model in the ungauged basin.

  8. High spatial-temporal resolution and integrated surface and subsurface precipitation-runoff modelling for a small stormwater catchment

    Science.gov (United States)

    Hailegeorgis, Teklu T.; Alfredsen, Knut

    2018-02-01

    useful for better computation of runoff generated from different land cover, for assessments of stormwater management techniques (e.g. the Low Impact Development or LID) and the impacts of land cover and climate change. There are some simplifications or limitations such as the runoff routing does not involve detailed sewer hydraulics, effects of leakages from water supply systems and faulty/illegal connections from sanitary sewer are not considered, the model cannot identify actual locations of the interactions between the subsurface runoff and sewer pipes and lacks parsimony.

  9. Development of a Consistent GIS Based Method for Estimating the Groundwater Runoff Parameter for Regional Scale Precipitation-Runoff Models

    Science.gov (United States)

    Bjerklie, D. M.

    2014-12-01

    As part of a U. S. Geological Survey effort to (1) estimate river discharge in ungaged basins, (2) understand runoff quantity and timing for watersheds between gaging stations, and (3) estimate potential future streamflow, a national scale precipitation runoff model is in development. The effort uses the USGS Precipitation Runoff Modeling System (PRMS) model. The model development strategy includes methods to assign hydrologic routing coefficients a priori from national scale GIS data bases. Once developed, the model can serve as an initial baseline for more detailed and locally/regionally calibrated models designed for specific projects and purposes. One of the key hydrologic routing coefficients is the groundwater coefficient (gw_coef). This study estimates the gw_coef from continental US GIS data, including geology, drainage density, aquifer type, vegetation type, and baseflow index information. The gw_coef is applied in regional PRMS models and is estimated using two methods. The first method uses a statistical model to predict the gw_coef from weighted average values of surficial geologic materials, dominant aquifer type, baseflow index, vegetation type, and the drainage density. The second method computes the gw_coef directly from the physical conditions in the watershed including the percentage geologic material and the drainage density. The two methods are compared against the gw_coef derived from streamflow records, and tested for selected rivers in different regions of the country. To address the often weak correlation between geology and baseflow, the existence of groundwater sinks, and complexities of groundwater flow paths, the spatial characteristics of the gw_coef prediction error were evaluated, and a correction factor developed from the spatial error distribution. This provides a consistent and improved method to estimate the gw_coef for regional PRMS models that is derived from available GIS data and physical information for watersheds.

  10. Comparing projections of future changes in runoff from hydrological and biome models in ISI-MIP

    NARCIS (Netherlands)

    Davie, J. C. S.; Falloon, P. D.; Kahana, R.; Dankers, R.; Betts, R.; Portmann, F. T.; Wisser, D.; Clark, D. B.; Ito, A.; Masaki, Y.; Nishina, K.; Fekete, B.; Tessler, Z.; Wada, Y.; Liu, X.; Tang, Q.; Hagemann, S.; Stacke, T.; Pavlick, R.; Schaphoff, S.; Gosling, S. N.; Franssen, W.; Arnell, N.

    2013-01-01

    Future changes in runoff can have important implications for water resources and flooding. In this study, runoff projections from ISI-MIP (Inter-sectoral Impact Model Intercomparison Project) simulations forced with HadGEM2-ES bias-corrected climate data under the Representative Concentration

  11. Comparing projections of future changes in runoff from hydrological and biome models in ISI-MIP

    NARCIS (Netherlands)

    Davie, J.C.S.; Falloon, P.D.; Kahana, R.; Dankers, R.; Betts, R.; Portmann, F.T.; Wisser, D.; Clark, D.B.; Ito, A.; Masaki, Y.; Nishina, K.; Fekete, B.; Tessler, Z.; Wada, Y.; Liu, X.; Tang, Q.; Hagemann, S.; Stacke, T.; Pavlick, R.; Schaphoff, S.; Gosling, S.N.; Franssen, W.H.P.; Arnell, N.

    2013-01-01

    Future changes in runoff can have important implications for water resources and flooding. In this study, runoff projections from ISI-MIP (Inter-sectoral Impact Model Inter-comparison Project) simulations forced with HadGEM2-ES bias-corrected climate data under the Representative Concentration

  12. 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...

  13. Subsurface and terrain controls on runoff generation in deep soil landscapes

    Science.gov (United States)

    Mallard, John; McGlynn, Brian; Richter, Daniel

    2017-04-01

    Our understanding of runoff generation in regions characterized by deep, highly weathered soils is incomplete despite the prevalence of this setting worldwide. To address this, we instrumented a first-order watershed in the Piedmont of South Carolina, USA. The Piedmont region of the United States extends east of the Appalachians from Maryland to Alabama, and is home to some of the most rapid population growth in the country. Regional and local relief is modest, although the landscape is highly dissected and local slope can be quite variable. The region's soils are ancient, deeply weathered, and characterized by sharp changes in hydrologic properties due to concentration of clay in the Bt horizon. Despite a mild climate and consistent precipitation, seasonally variable energy availability and deciduous tree cover create a strong evapotranspiration mediated seasonal hydrologic dynamic: while moist soils and extended stream networks are typical of the late fall through spring, relatively dry soils and contracting stream networks emerge in the summer and early fall. To elucidate the control of the complex vertical and planform structure of this region, as well as the strongly seasonal subsurface hydrology, on runoff generation, we installed a network of nested, shallow groundwater wells across an ephemeral to first-order watershed to continuously measure internal water levels. We also recorded local precipitation and discharge at the outlet of this watershed, a similar adjacent watershed, and in the second to third order downstream watershed. Subsurface water dynamics varied spatially, vertically, and seasonally. Shallow depths and landscape positions with minimal contributing area exhibited flashier dynamics comparable to the stream hydrographs while positions with more contributing area exhibited relatively muted dynamics. Most well positions showed minimal response to precipitation throughout the summer, and even occasionally observed response rarely co

  14. Terrain and subsurface influences on runoff generation in a steep, deep, highly weathered system

    Science.gov (United States)

    Mallard, J. M.; McGlynn, B. L.; Richter, D. D., Jr.

    2017-12-01

    Our understanding of runoff generation in regions characterized by deep, highly weathered soils is incomplete, despite the prevalence occupation of these landscapes worldwide. To address this, we instrumented a first-order watershed in the Piedmont of South Carolina, USA, a region that extends east of the Appalachians from Maryland to Alabama, and home to some of the most rapid population growth in the country. Although regionally the relief is modest, the landscape is often highly dissected and local slopes can be steep and highly varied. The typical soils of the region are kaolinite dominated ultisols, with hydrologic properties controlled by argillic Bt horizons, often with >50% clay-size fraction. The humid subtropical climate creates relatively consistent precipitation intra-annually and seasonally variable energy availability. Consequently, the mixed deciduous and coniferous tree cover creates a strong evapotranspiration-mediated hydrologic dynamic. While moist soils and extended stream networks are typical from late fall through spring, relatively dry soils and contracting stream networks emerge in the summer and early fall. Here, we seek to elucidate the relative influence of the vertical soil and spatial terrain structure of this region on watershed hillslope hydrology and subsequent runoff generation. We installed a network of nested, shallow groundwater wells and soil water content probes within an ephemeral to first-order watershed to continuously measure soil and groundwater dynamics across soil horizons and landscape position. We also recorded local precipitation and discharge from this watershed. Most landscape positions exhibited minimal water table response to precipitation throughout dry summer periods, with infrequently observed responses rarely coincident with streamflow generation. In contrast, during the wetter late fall through early spring period, streamflow was driven by the interaction between transient perched water tables and

  15. A geomorphology-based ANFIS model for multi-station modeling of rainfall-runoff process

    Science.gov (United States)

    Nourani, Vahid; Komasi, Mehdi

    2013-05-01

    This paper demonstrates the potential use of Artificial Intelligence (AI) techniques for predicting daily runoff at multiple gauging stations. Uncertainty and complexity of the rainfall-runoff process due to its variability in space and time in one hand and lack of historical data on the other hand, cause difficulties in the spatiotemporal modeling of the process. In this paper, an Integrated Geomorphological Adaptive Neuro-Fuzzy Inference System (IGANFIS) model conjugated with C-means clustering algorithm was used for rainfall-runoff modeling at multiple stations of the Eel River watershed, California. The proposed model could be used for predicting runoff in the stations with lack of data or any sub-basin within the watershed because of employing the spatial and temporal variables of the sub-basins as the model inputs. This ability of the integrated model for spatiotemporal modeling of the process was examined through the cross validation technique for a station. In this way, different ANFIS structures were trained using Sugeno algorithm in order to estimate daily discharge values at different stations. In order to improve the model efficiency, the input data were then classified into some clusters by the means of fuzzy C-means (FCMs) method. The goodness-of-fit measures support the gainful use of the IGANFIS and FCM methods in spatiotemporal modeling of hydrological processes.

  16. Independent effects of temperature and precipitation on modeled runoff in the conterminous United States

    Science.gov (United States)

    McCabe, G.J.; Wolock, D.M.

    2011-01-01

    A water-balance model is used to simulate time series of water-year runoff for 4 km ?? 4 km grid cells for the conterminous United States during the 1900-2008 period. Model outputs are used to examine the separate effects of precipitation and temperature on runoff variability. Overall, water-year runoff has increased in the conterminous United States and precipitation has accounted for almost all of the variability in water-year runoff during the past century. In contrast, temperature effects on runoff have been small for most locations in the United States even during periods when temperatures for most of the United States increased significantly. Copyright 2011 by the American Geophysical Union.

  17. The Interplay Between Transpiration and Runoff Formulations in Land Surface Schemes Used with Atmospheric Models

    Science.gov (United States)

    Koster, Rindal D.; Milly, P. C. D.

    1997-01-01

    The Project for Intercomparison of Land-surface Parameterization Schemes (PILPS) has shown that different land surface models (LSMS) driven by the same meteorological forcing can produce markedly different surface energy and water budgets, even when certain critical aspects of the LSMs (vegetation cover, albedo, turbulent drag coefficient, and snow cover) are carefully controlled. To help explain these differences, the authors devised a monthly water balance model that successfully reproduces the annual and seasonal water balances of the different PILPS schemes. Analysis of this model leads to the identification of two quantities that characterize an LSM's formulation of soil water balance dynamics: (1) the efficiency of the soil's evaporation sink integrated over the active soil moisture range, and (2) the fraction of this range over which runoff is generated. Regardless of the LSM's complexity, the combination of these two derived parameters with rates of interception loss, potential evaporation, and precipitation provides a reasonable estimate for the LSM's simulated annual water balance. The two derived parameters shed light on how evaporation and runoff formulations interact in an LSM, and the analysis as a whole underscores the need for compatibility in these formulations.

  18. Precipitation-Runoff Modeling System (PRMS) and Streamflow Response to Spatially Distributed Precipitation in Two Large Watersheds in Northern California

    Science.gov (United States)

    Dhakal, A. S.; Adera, S.; Niswonger, R. G.; Gardner, M.

    2016-12-01

    The ability of the Precipitation-Runoff Modeling System (PRMS) to predict peak intensity, peak timing, base flow, and volume of streamflow was examined in Arroyo Hondo (180 km2) and Upper Alameda Creek (85 km2), two sub-watersheds of the Alameda Creek watershed in Northern California. Rainfall-runoff volume ratios vary widely, and can exceed 0.85 during mid-winter flashy rainstorm events. Due to dry antecedent soil moisture conditions, the first storms of the hydrologic year often produce smaller rainfall-runoff volume ratios. Runoff response in this watershed is highly hysteretic; large precipitation events are required to generate runoff following a 4-week period without precipitation. After about 150 mm of cumulative rainfall, streamflow responds quickly to subsequent storms, with variations depending on rainstorm intensity. Inputs to PRMS included precipitation, temperature, topography, vegetation, soils, and land cover data. The data was prepared for input into PRMS using a suite of data processing Python scripts written by the Desert Research Institute and U.S. Geological Survey. PRMS was calibrated by comparing simulated streamflow to measured streamflow at a daily time step during the period 1995 - 2014. The PRMS model is being used to better understand the different patterns of streamflow observed in the Alameda Creek watershed. Although Arroyo Hondo receives more rainfall than Upper Alameda Creek, it is not clear whether the differences in streamflow patterns are a result of differences in rainfall or other variables, such as geology, slope and aspect. We investigate the ability of PRMS to simulate daily streamflow in the two sub-watersheds for a variety of antecedent soil moisture conditions and rainfall intensities. After successful simulation of watershed runoff processes, the model will be expanded using GSFLOW to simulate integrated surface water and groundwater to support water resources planning and management in the Alameda Creek watershed.

  19. Evaluation of the precipitation-runoff modeling system, Beaver Creek basin, Kentucky

    Science.gov (United States)

    Bower, D.E.

    1985-01-01

    The Precipitation Runoff Modeling System (PRMS) was evaluated with data from Cane branch and Helton Branch in the Beaver Creek basin of Kentucky. Because of previous studies, 10.6 years of record were available to establish a data base for the basin including 60 storms for Cane Branch and 50 storms for Helton Branch. The model was calibrated initially using data from the 1956-58 water years. Runoff predicted by the model was 94.7% of the observed runoff at Cane Branch (mined area) and 96.9% at Helton Branch (unmined area). After the model and data base were modified, the model was refitted to the 1956-58 data for Helton Branch. It then predicted 98.6% of the runoff for the 10.6-year period. The model parameters from Helton Branch were then used to simulate the Cane Branch runoff and discharge. The model predicted 102.6% of the observed runoff at Cane Branch for the 10.6 years. The simulations produced reasonable storm volumes and peak discharges. Sensitivity analysis of model parameters indicated the parameters associated with soil moisture are the most sensitive. The model was used to predict sediment concentration and daily sediment load for selected storm periods. The sediment computations indicated the model can be used to predict sediment concentrations during storm events. (USGS)

  20. Numerical model of rainwater runoff over the catchment surface and ...

    African Journals Online (AJOL)

    ... runoff along the surface catchment and transport of impurity which permeates into the water flow from soil at the certain areas of this surface. This system consists of two types of equations: the first of them describes the changes of water layer thickness over the slope surface given the precipitation and evaporation, and the ...

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

    Indian Academy of Sciences (India)

    reliable runoff is hardly predicted by applying linear and non-linear regression methods. Therefore, in this study ... propagation network (FFBP) and conventional regression analysis (CRA) were employed to study their performances. From the .... tested ANNs against the regression-based, simple conceptual black box, or ...

  2. Rainfall-runoff modelling of Ajay river catchment using SWAT model

    Science.gov (United States)

    Kangsabanik, Subhadip; Murmu, Sneha

    2017-05-01

    The present study is based on SWAT (Soil and Water Assessment Tool) Model which integrates the GIS information with attribute database to estimate the runoff of Ajay River catchment. Soil and Water Assessment Tool (SWAT) is a physically based distributed parameter model which has been developed to predict runoff, erosion, sediment and nutrient transport from agricultural watersheds under different management practices. The SWAT Model works in conjunction with Arc GIS. In the present study the catchment area has been delineated using the DEM (Digital Elevation Model) and then divided into 19 sub-basins. For preparation of landuse map the IRS-P6 LISS-III image has been used and the soil map is extracted from HWSD (Harmonized World Soil Database) Raster world soil map. The sub basins are further divided into 223 HRUs which stands for Hydrological Response Unit. Then by using 30 years of daily rainfall data and daily maximum and minimum temperature data SWAT simulation is done for daily, monthly and yearly basis to find out Runoff for corresponding Rainfall. The coefficient of correlation (r) for rainfall in a period and the corresponding runoff is found to be 0.9419.

  3. Mid- and long-term runoff predictions by an improved phase-space reconstruction model

    International Nuclear Information System (INIS)

    Hong, Mei; Wang, Dong; Wang, Yuankun; Zeng, Xiankui; Ge, Shanshan; Yan, Hengqian; Singh, Vijay P.

    2016-01-01

    In recent years, the phase-space reconstruction method has usually been used for mid- and long-term runoff predictions. However, the traditional phase-space reconstruction method is still needs to be improved. Using the genetic algorithm to improve the phase-space reconstruction method, a new nonlinear model of monthly runoff is constructed. The new model does not rely heavily on embedding dimensions. Recognizing that the rainfall–runoff process is complex, affected by a number of factors, more variables (e.g. temperature and rainfall) are incorporated in the model. In order to detect the possible presence of chaos in the runoff dynamics, chaotic characteristics of the model are also analyzed, which shows the model can represent the nonlinear and chaotic characteristics of the runoff. The model is tested for its forecasting performance in four types of experiments using data from six hydrological stations on the Yellow River and the Yangtze River. Results show that the medium-and long-term runoff is satisfactorily forecasted at the hydrological stations. Not only is the forecasting trend accurate, but also the mean absolute percentage error is no more than 15%. Moreover, the forecast results of wet years and dry years are both good, which means that the improved model can overcome the traditional ‘‘wet years and dry years predictability barrier,’’ to some extent. The model forecasts for different regions are all good, showing the universality of the approach. Compared with selected conceptual and empirical methods, the model exhibits greater reliability and stability in the long-term runoff prediction. Our study provides a new thinking for research on the association between the monthly runoff and other hydrological factors, and also provides a new method for the prediction of the monthly runoff. - Highlights: • The improved phase-space reconstruction model of monthly runoff is established. • Two variables (temperature and rainfall) are incorporated

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

    Czech Academy of Sciences Publication Activity Database

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  6. Meltwater flux and runoff modeling in the abalation area of jakobshavn Isbrae, West Greenland

    Energy Technology Data Exchange (ETDEWEB)

    Mernild, Sebastian Haugard [Los Alamos National Laboratory; Chylek, Petr [Los Alamos National Laboratory; Liston, Glen [COLORADO STATE UNIV.; Steffen, Konrad [UNIV OF COLORADO

    2009-01-01

    The temporal variability in surface snow and glacier melt flux and runoff were investigated for the ablation area of lakobshavn Isbrae, West Greenland. High-resolution meteorological observations both on and outside the Greenland Ice Sheet (GrIS) were used as model input. Realistic descriptions of snow accumulation, snow and glacier-ice melt, and runoff are essential to understand trends in ice sheet surface properties and processes. SnowModel, a physically based, spatially distributed meteorological and snow-evolution modeling system was used to simulate the temporal variability of lakobshavn Isbrre accumulation and ablation processes for 2000/01-2006/07. Winter snow-depth observations and MODIS satellite-derived summer melt observations were used for model validation of accumulation and ablation. Simulations agreed well with observed values. Simulated annual surface melt varied from as low as 3.83 x 10{sup 9} m{sup 3} (2001/02) to as high as 8.64 x 10{sup 9} m{sup 3} (2004/05). Modeled surface melt occurred at elevations reaching 1,870 m a.s.l. for 2004/05, while the equilibrium line altitude (ELA) fluctuated from 990 to 1,210 m a.s.l. during the simulation period. The SnowModel meltwater retention and refreezing routines considerably reduce the amount of meltwater available as ice sheet runoff; without these routines the lakobshavn surface runoff would be overestimated by an average of 80%. From September/October through May/June no runoff events were simulated. The modeled interannual runoff variability varied from 1.81 x 10{sup 9} m{sup 3} (2001/02) to 5.21 x 10{sup 9} m{sup 3} (2004/05), yielding a cumulative runoff at the Jakobshavn glacier terminus of {approx}2.25 m w.eq. to {approx}4.5 m w.eq., respectively. The average modeled lakobshavn runoff of {approx}3.4 km{sup 3} y{sup -1} was merged with previous estimates of Jakobshavn ice discharge to quantify the freshwater flux to Illulissat Icefiord. For both runoff and ice discharge the average trends are

  7. Modeling wildfire impact on hydrologic processes using the Precipitation Runoff Modeling System

    Science.gov (United States)

    Logan, R. J.; Hogue, T. S.; Hay, L.

    2015-12-01

    As large magnitude wildfires persist across the western United States, understanding their impact on hydrologic behavior and predicting regional streamflow response is increasingly important. Sediment and debris flows, as well as elevated flood levels in burned watersheds are often addressed, but wildfires also alter the timing and overall volume of both short and long-term runoff, making the prediction of post-fire streamflow critical for water resources management. Watershed models are a powerful tool for both representing wildfire runoff response and discerning the processes that induce that response. In the current study, selected wildfire-impacted basins across the western United States are modeled using the Precipitation Runoff Modeling System (PRMS) in order to develop a generalized approach. This distributed-parameter, physical process based watershed model allows us to target specific processes, while still having the flexibility to account for uncertainty and complex physical interactions that are not explicitly represented in model parameterization. Two change detection modeling approaches are considered. First, models calibrated using pre-fire data are applied to the post-fire period and residuals between simulated and observed flow are examined to quantify the response in each specific watershed. Here an analysis of the model's ability to detect long-term response is also presented. Second, the post-fire conditions are modeled by adjusting appropriate parameters, and the parameter differences are used to guide process learning. In this latter method, parameters are specifically tailored to represent processes affected by wildfire, and scenarios with different parameter interactions are statistically compared. The results of these analyses are synthesized to provide a framework for predicting wildfire runoff response using PRMS, which will ultimately empower water resource decisions.

  8. Assessment of rainfall-runoff modelling for climate change mitigation

    Science.gov (United States)

    Otieno, Hesbon; Han, Dawei; Woods, Ross

    2015-04-01

    Sustainable water resources management requires reliable methods for quantification of hydrological variables. This is a big challenge in developing countries, due to the problem of inadequate data as a result of sparse gauge networks. Successive occurrence of both abundance and shortage of water can arise in a catchment within the same year, with deficit situations becoming an increasingly occurring phenomenon in Kenya. This work compares the performance of two models in the Tana River catchment in Kenya, in generation of synthetic flow data. One of the models is the simpler USGS Thornthwaite monthly water balance model that uses a monthly time step and has three parameters. In order to explore alternative modelling schemes, the more complex Pitman model with 19 parameters was also applied in the catchment. It is uncertain whether the complex model (Pitman) will do better than the simple model, because a model with a large number of parameters may do well in the current system but poorly in future. To check this we have used old data (1970-1985) to calibrate the models and to validate with recent data (after 1985) to see which model is robust over time. This study is relevant and useful to water resources managers in scenario analysis for water resources management, planning and development in African countries with similar climates and catchment conditions.

  9. Use of rainfall-simulator data in precipitation-runoff modeling studies

    Science.gov (United States)

    Lusby, G.C.; Lichty, R.W.

    1983-01-01

    Results of a study using a rainfall simulator to define infiltration parameters for use in watershed modeling are presented. A total of 23 rainfall-simulation runs were made on five small plots representing four representative soil-vegetation types of the study watershed in eastern Colorado. Data for three observed rainfall-runoff events were recorded by gages on four of the plots. Data from all events were used to develop best-fit parameters of the Green and Ampt infiltration equation. The hydraulic conductivity of the transmission zone, KSAT, grossly controlled the goodness of fit of all modeling attempts. Results of fitting KSAT to reproduce runoff from rainfall simulator runs and results of fitting KSAT to reproduce runoff from observed rainfall-runoff events are inconsistent. Variations in results from site to site and at different times of the year were observed. (USGS)

  10. Glacier surface mass balance and freshwater runoff modeling for the entire Andes Cordillera

    Science.gov (United States)

    Mernild, Sebastian H.; Liston, Glen E.; Yde, Jacob C.

    2017-04-01

    Glacier surface mass balance (SMB) observations for the Andes Cordillera are limited and, therefore, estimates of the SMB contribution from South America to sea-level rise are highly uncertain. Here, we simulate meteorological, snow, glacier surface, and hydrological runoff conditions and trends for the Andes Cordillera (1979/80-2013/14), covering the tropical latitudes in the north down to the sub-polar latitudes in the far south, including the Northern Patagonia Ice Field (NPI) and Southern Patagonia Ice Field (SPI). SnowModel - a fully integrated energy balance, blowing-snow distribution, multi-layer snowpack, and runoff routing model - was used to simulate glacier SMBs for the Andes Cordillera. The Randolph Glacier Inventory and NASA Modern-Era Retrospective Analysis for Research and Applications products, downscaled in SnowModel, allowed us to conduct relatively high-resolution simulations. The simulated glacier SMBs were verified against independent directly-observed and satellite gravimetry and altimetry-derived SMB, indicating a good statistical agreement. For glaciers in the Andes Cordillera, the 35-year mean annual SMB was found to be -1.13 m water equivalent. For both NPI and SPI, the mean SMB was positive (where calving is the likely reason for explaining why geodetic estimates are negative). Further, the spatio-temporal freshwater river runoff patterns from individual basins, including their runoff magnitude and change, were simulated. For the Andes Cordillera rivers draining to the Pacific Ocean, 86% of the simulated runoff originated from rain, 12% from snowmelt, and 2% from ice melt, whereas, for example, for Chile, the water-source distribution was 69, 24, and 7%, respectively. Along the Andes Cordillera, the 35-year mean basin outlet-specific runoff (L s-1 km-2) showed a characteristic regional hourglass shape pattern with highest runoff in both Colombia and Ecuador and in Patagonia, and lowest runoff in the Atacama Desert area.

  11. PRMS-IV, the precipitation-runoff modeling system, version 4

    Science.gov (United States)

    Markstrom, Steven L.; Regan, R. Steve; Hay, Lauren E.; Viger, Roland J.; Webb, Richard M.; Payn, Robert A.; LaFontaine, Jacob H.

    2015-01-01

    Computer models that simulate the hydrologic cycle at a watershed scale facilitate assessment of variability in climate, biota, geology, and human activities on water availability and flow. This report describes an updated version of the Precipitation-Runoff Modeling System. The Precipitation-Runoff Modeling System is a deterministic, distributed-parameter, physical-process-based modeling system developed to evaluate the response of various combinations of climate and land use on streamflow and general watershed hydrology. Several new model components were developed, and all existing components were updated, to enhance performance and supportability. This report describes the history, application, concepts, organization, and mathematical formulation of the Precipitation-Runoff Modeling System and its model components. This updated version provides improvements in (1) system flexibility for integrated science, (2) verification of conservation of water during simulation, (3) methods for spatial distribution of climate boundary conditions, and (4) methods for simulation of soil-water flow and storage.

  12. Granulometric characterization of sediments transported by surface runoff generated by moving storms

    Directory of Open Access Journals (Sweden)

    J. L. M. P. de Lima

    2008-12-01

    Full Text Available Due to the combined effect of wind and rain, the importance of storm movement to surface flow has long been recognized, at scales ranging from headwater scales to large basins. This study presents the results of laboratory experiments designed to investigate the influence of moving rainfall storms on the dynamics of sediment transport by surface runoff. Experiments were carried out, using a rain simulator and a soil flume. The movement of rainfall was generated by moving the rain simulator at a constant speed in the upstream and downstream directions along the flume. The main objective of the study was to characterize, in laboratory conditions, the distribution of sediment grain-size transported by rainfall-induced overland flow and its temporal evolution. Grain-size distribution of the eroded material is governed by the capacity of flow that transports sediments. Granulometric curves were constructed using conventional hand sieving and a laser diffraction particle size analyser (material below 0.250 mm for overland flow and sediment deliveries collected at the flume outlet. Surface slope was set at 2%, 7% and 14%. Rainstorms were moved with a constant speed, upslope and downslope, along the flume or were kept static. The results of laboratory experiments show that storm movement, affecting the spatial and temporal distribution of rainfall, has a marked influence on the grain-size characteristics of sediments transported by overland flow. The downstream-moving rainfall storms have higher stream power than do other storm types.

  13. Modelling runoff depth and connectivity in commercial vineyards (DO Somontano, Huesca, NE Spain)

    Science.gov (United States)

    López-Vicente, Manuel, , Dr.; Navas, Ana, , Dr.

    2015-04-01

    Surface runoff, soil redistribution and sediment delivery are non-linear processes that depend on many parameters, and thus, numerical simulation of overland flow, sediments and other solutes connectivity is a complex and non-solved task. Additionally, man-made landscape linear elements (LLEs: unpaved and paved trails, roads, land levelling, irrigation ditches, stone walls, dams, etc.) modify the natural patterns of connectivity. Mediterranean soils have been cultivated for hundreds and thousands of years and landscapes appear intensively modified. Vineyards are one of the most ancient crops in Mediterranean countries and recently in other countries around the World. In this study, we run the IC model of connectivity (Borselli et al., 2008, doi:10.1016/j.catena.2008.07.006) and the water balance DR2-2013© SAGA v1.1 model (López-Vicente et al., 2014, doi:10.1016/j.envsoft.2014.08.025; software freely downloaded at http://digital.csic.es/handle/10261/93543) in a vineyard (26.4 ha) composed by four fields (6.2 ha) and their upslope drainage area. These commercial fields belong to a winery included in the Somontano certificate of origin. All input maps are generated at 5 x 5 m of cell size and the digital elevation model is based on LIDAR technology. The map of connectivity showed the typical spatial pattern of overland flow though values of connectivity varied along the whole map. The average value was -2.65 (sd = -0.62) and within the four vineyards was -2.46 (sd = -0.65). High connectivity appeared in bare soil areas, in the unpaved trail and within some sections of the main pathways. The lowest connectivity appeared in the forest and in small areas within the vineyards. The effective rainfall (ER) that reaches the soils, was 88% on average (384 mm) from the total rainfall depth (436 mm yr-1) and the average initial runoff, before overland flow processes, was 382 mm yr-1 (sd = 31 mm). The ER within the vineyards was 81%. The effective runoff (CQeff) ranged from 0

  14. Ungauged runoff simulation in Upper Manyame Catchment, Zimbabwe: Application of the HEC-HMS model

    Science.gov (United States)

    Gumindoga, Webster; Rwasoka, Donald T.; Nhapi, Innocent; Dube, Timothy

    2017-08-01

    The Hydrologic Engineering Center Hydrologic Modelling System (HEC-HMS) model was applied to simulate runoff in the ten gauged and ungauged Upper Manyame subcatchments in Zimbabwe. Remote sensing and Geographic Information System techniques were used to determine the geometric and hydrologic parameters required for estimating model parameters. The Snyder Unit Hydrograph method was used for ungauged subcatchment simulations based on parameter transfer from gauged subcatchments. The Marimba and Mukuvisi subcatchments were considered as the gauged subcatchments based on data completeness for the simulation period (2004-2010). Before extrapolating the calibrated model setup to eight ungauged subcatchments, the feasibility of model parameter transferability was tested, using the proxy - catchment approach and evaluated using the Nash Sutcliffe (NSE) and Relative Volume Error (RVE) criterion. Results showed that the model successfully predicted gauged catchment runoff and peakflows for the calibration (Marimba NSE = 68%, RVE = 5.8%; Mukuvisi NSE = 64%, RVE = -8.9%) and validation (Marimba NSE = 61%, RVE = 8.1%; Mukuvisi NSE = 57%, RVE = 9.9%) periods. The study demonstrates the suitability of HEC-HMS for continuous runoff simulation in a complex watershed with numerous subcatchments and channel reaches. The ungauged subcatchments contribute to 51% of Upper Manyame Catchment's runoff. Ruwa and Lake Chivero subcatchments had the highest ungauged subcatchment contribution to Upper Manyame Catchment runoff (19% and 15% respectively). This work will have a significant contribution for the future development of water resources programs in Upper Manyame Catchment in particular and in other data-scarce catchments.

  15. Precipitation-runoff and streamflow-routing models for the Willamette River basin, Oregon

    Science.gov (United States)

    Laenen, Antonius; Risley, John C.

    1997-01-01

    Precipitation-runoff and streamflow-routing models were constructed and assessed as part of a water-quality study of the Willamette River Basin. The study was a cooperative effort between the U.S. Geological Survey (USGS) and the Oregon Department of Environmental Quality (ODEQ) and was coordinated with the USGS National Water-Quality Assessment (NAWQA) study of the Willamette River. Routing models are needed to estimate streamflow so that water-quality constituent loads can be calculated from measured concentrations and so that sources, sinks, and downstream changes in those loads can be identified. Runoff models are needed to estimate ungaged-tributary inflows for routing models and to identify flow contributions from different parts of the basin. The runoff and routing models can be run either separately or together to simulate streamflow at various locations and to examine streamflow contributions from overland flow, shallow-subsurface flow, and ground-water flow.

  16. Modeling spray drift and runoff-related inputs of pesticides to receiving water.

    Science.gov (United States)

    Zhang, Xuyang; Luo, Yuzhou; Goh, Kean S

    2018-03-01

    Pesticides move to surface water via various pathways including surface runoff, spray drift and subsurface flow. Little is known about the relative contributions of surface runoff and spray drift in agricultural watersheds. This study develops a modeling framework to address the contribution of spray drift to the total loadings of pesticides in receiving water bodies. The modeling framework consists of a GIS module for identifying drift potential, the AgDRIFT model for simulating spray drift, and the Soil and Water Assessment Tool (SWAT) for simulating various hydrological and landscape processes including surface runoff and transport of pesticides. The modeling framework was applied on the Orestimba Creek Watershed, California. Monitoring data collected from daily samples were used for model evaluation. Pesticide mass deposition on the Orestimba Creek ranged from 0.08 to 6.09% of applied mass. Monitoring data suggests that surface runoff was the major pathway for pesticide entering water bodies, accounting for 76% of the annual loading; the rest 24% from spray drift. The results from the modeling framework showed 81 and 19%, respectively, for runoff and spray drift. Spray drift contributed over half of the mass loading during summer months. The slightly lower spray drift contribution as predicted by the modeling framework was mainly due to SWAT's under-prediction of pesticide mass loading during summer and over-prediction of the loading during winter. Although model simulations were associated with various sources of uncertainties, the overall performance of the modeling framework was satisfactory as evaluated by multiple statistics: for simulation of daily flow, the Nash-Sutcliffe Efficiency Coefficient (NSE) ranged from 0.61 to 0.74 and the percent bias (PBIAS) modeling framework will be useful for assessing the relative exposure from pesticides related to spray drift and runoff in receiving waters and the design of management practices for mitigating pesticide

  17. Daily rainfall-runoff modelling by neural networks in semi-arid zone ...

    African Journals Online (AJOL)

    This research work will allow checking efficiency of formal neural networks for flows' modelling of wadi Ouahrane's basin from rainfall-runoff relation which is non-linear. Two models of neural networks were optimized through supervised learning and compared in order to achieve this goal, the first model with input rain, and ...

  18. Rainfall-runoff modeling in the Turkey River using numerical and ...

    African Journals Online (AJOL)

    In this research, two numerical models including ANN and ANFIS were used to model the rainfall-runoff process and the best model was chosen. Also, by using SPSS software, the regression equations were developed and then the best equation was selected from regression analysis. The obtained results from the ...

  19. The ensemble particle filter (EnPF) in rainfall-runoff models

    NARCIS (Netherlands)

    Van Delft, G.; El Serafy, G.Y.; Heemink, A.W.

    2009-01-01

    Rainfall-runoff models play a very important role in flood forecasting. However, these models contain large uncertainties caused by errors in both the model itself and the input data. Data assimilation techniques are being used to reduce these uncertainties. The ensemble Kalman filter (EnKF) and the

  20. Applying a Multi-Model Ensemble Method for Long-Term Runoff Prediction under Climate Change Scenarios for the Yellow River Basin, China

    Directory of Open Access Journals (Sweden)

    Linus Zhang

    2018-03-01

    Full Text Available Given the substantial impacts that are expected due to climate change, it is crucial that accurate rainfall–runoff results are provided for various decision-making purposes. However, these modeling results often generate uncertainty or bias due to the imperfect character of individual models. In this paper, a genetic algorithm together with a Bayesian model averaging method are employed to provide a multi-model ensemble (MME and combined runoff prediction under climate change scenarios produced from eight rainfall–runoff models for the Yellow River Basin. The results show that the multi-model ensemble method, especially the genetic algorithm method, can produce more reliable predictions than the other considered rainfall–runoff models. These results show that it is possible to reduce the uncertainty and thus improve the accuracy for future projections using different models because an MME approach evens out the bias involved in the individual model. For the study area, the final combined predictions reveal that less runoff is expected under most climatic scenarios, which will threaten water security of the basin.

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

    Science.gov (United States)

    Zhang, Jun; Han, Dawei

    2017-12-01

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

  2. Black carbon induced glacial melt runoff prediction using validated modelled estimates at Himalaya-Hindu Kush region

    Science.gov (United States)

    Chakraborty, I.; Verma, S.; Kumar, B. D.; Boucher, O.

    2016-12-01

    This study is aimed at mapping the BC distribution and simultaneous detection of the sites prone to become crucial points of major snowmelt runoff in the Hindu Kush Himalayan region (HKH). Prediction of the glacial excess melting phenomenon were anticipated by using the validated modelled estimates of atmospheric mass BC concentration to get a conservative estimate of the BC deposition on snow, which is considered as one of the precursors to excess thawing of the ice. Modelled simulations were validated with respect to measurements carried out at higher altitude (Hanle, NCOP, Satopanth) and lower altitude stations (Nainital, Kullu and Dehradun). Models were found to capture more than 50% of the measured concentration at all higher altitude stations with greater variations of modelled estimates at lower altitudes begetting the need of upgraded retrieval simulation formulation for comparison with the measured estimates. The retrieval simulations narrated a concurrency of 86% to 100% with the measured data at the lower altitudes. At the glacial regions BC deposition as high as 314 µg kg- 1 (range being 150-220 µg kg - 1) corresponding to atmospheric BC mass concentration tends to cause excess snow melt runoff generation. Estimated annual runoff increase (ARI) in the HKH region was observed to be as high as 10%. Snow albedo reduction (SAR), one of the pre-cursors to excess ablation was found to have a range of 10-24%. The simulated trend of BC deposition, ARI and SAR prior to 1961 in the HKH region was stable with no considerable increase in the annual estimated values. Subsequent to 1961, model estimated BC deposition rates and the corresponding estimated SAR depict increase in SAR and ARI for the glaciers in Hindu-Kush Himalayan region. The modelled grids of BC concentration in the region can further be used for better run-off and erosion management.

  3. Real time adjustment of slow changing flow components in distributed urban runoff models

    DEFF Research Database (Denmark)

    Borup, Morten; Grum, M.; Mikkelsen, Peter Steen

    2011-01-01

    In many urban runoff systems infiltrating water contributes with a substantial part of the total inflow and therefore most urban runoff modelling packages include hydrological models for simulating the infiltrating inflow. This paper presents a method for deterministic updating of the hydrological....... This information is then used to update the states of the hydrological model. The method is demonstrated on the 20 km2 Danish urban catchment of Ballerup, which has substantial amount of infiltration inflow after succeeding rain events, for a very rainy period of 17 days in August 2010. The results show big...

  4. Applying a regional hydrology model to evaluate locations for groundwater replenishment with hillslope runoff under different climate and land use scenarios in an agricultural basin, central coastal California

    Science.gov (United States)

    Beganskas, S.; Young, K. S.; Fisher, A. T.; Lozano, S.; Harmon, R. E.; Teo, E. K.

    2017-12-01

    We are applying a regional hydrology model, Precipitation-Runoff Modeling System (PRMS), to evaluate locations for groundwater replenishment with hillslope runoff in the Pajaro Valley Groundwater Basin (PVGB), central coastal California. Stormwater managed aquifer recharge (MAR) projects collect hillslope runoff before it reaches a stream and infiltrate it into underlying aquifers, improving groundwater supply. The PVGB is a developed agricultural basin where groundwater provides >85% of water for irrigation and municipal needs; stormwater-MAR projects are being considered to address chronic overdraft and saltwater intrusion. We are applying PRMS to assess on a subwatershed scale (10-100 ha; 25-250 acres) where adequate runoff is generated to supply stormwater-MAR in coincidence with suitable conditions for infiltration and recharge. Data from active stormwater-MAR projects in the PVGB provide ground truth for model results. We are also examining how basinwide hydrology responds to changing land use and climate, and the potential implications for future water management. To prepare extensive input files for PRMS models, we developed ArcGIS and Python tools to delineate a topographic model grid and incorporate high-resolution soil, vegetation, and other physical data into each grid region; we also developed tools to analyze and visualize model output. Using historic climate records, we generated dry, normal, and wet climate scenarios, defined as having approximately 25th, 50th, and 75th percentile annual rainfall, respectively. We also generated multiple land use scenarios by replacing developed areas with native vegetation. Preliminary results indicate that many parts of the PVGB generate significant runoff and have suitable infiltration/recharge conditions. Reducing basinwide overdraft by 10% would require collecting less than 5% of total hillslope runoff, even during the dry scenario; this demonstrates that stormwater-MAR could be an effective water management

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  6. A two-stage storage routing model for green roof runoff detention.

    Science.gov (United States)

    Vesuviano, Gianni; Sonnenwald, Fred; Stovin, Virginia

    2014-01-01

    Green roofs have been adopted in urban drainage systems to control the total quantity and volumetric flow rate of runoff. Modern green roof designs are multi-layered, their main components being vegetation, substrate and, in almost all cases, a separate drainage layer. Most current hydrological models of green roofs combine the modelling of the separate layers into a single process; these models have limited predictive capability for roofs not sharing the same design. An adaptable, generic, two-stage model for a system consisting of a granular substrate over a hard plastic 'egg box'-style drainage layer and fibrous protection mat is presented. The substrate and drainage layer/protection mat are modelled separately by previously verified sub-models. Controlled storm events are applied to a green roof system in a rainfall simulator. The time-series modelled runoff is compared to the monitored runoff for each storm event. The modelled runoff profiles are accurate (mean Rt(2) = 0.971), but further characterization of the substrate component is required for the model to be generically applicable to other roof configurations with different substrate.

  7. Can Earth System Model Provide Reasonable Natural Runoff Estimates to Support Water Management Studies?

    Science.gov (United States)

    Kao, S. C.; Shi, X.; Kumar, J.; Ricciuto, D. M.; Mao, J.; Thornton, P. E.

    2017-12-01

    With the concern of changing hydrologic regime, there is a crucial need to better understand how water availability may change and influence water management decisions in the projected future climate conditions. Despite that surface hydrology has long been simulated by land model within the Earth System modeling (ESM) framework, given the coarser horizontal resolution and lack of engineering-level calibration, raw runoff from ESM is generally discarded by water resource managers when conducting hydro-climate impact assessments. To identify a likely path to improve the credibility of ESM-simulated natural runoff, we conducted regional model simulation using the land component (ALM) of the Accelerated Climate Modeling for Energy (ACME) version 1 focusing on the conterminous United States (CONUS). Two very different forcing data sets, including (1) the conventional 0.5° CRUNCEP (v5, 1901-2013) and (2) the 1-km Daymet (v3, 1980-2013) aggregated to 0.5°, were used to conduct 20th century transient simulation with satellite phenology. Additional meteorologic and hydrologic observations, including PRISM precipitation and U.S. Geological Survey WaterWatch runoff, were used for model evaluation. For various CONUS hydrologic regions (such as Pacific Northwest), we found that Daymet can significantly improve the reasonableness of simulated ALM runoff even without intensive calibration. The large dry bias of CRUNCEP precipitation (evaluated by PRISM) in multiple CONUS hydrologic regions is believed to be the main reason causing runoff underestimation. The results suggest that when driving with skillful precipitation estimates, ESM has the ability to produce reasonable natural runoff estimates to support further water management studies. Nevertheless, model calibration will be required for regions (such as Upper Colorado) where ill performance is showed for multiple different forcings.

  8. Application of pesticide transport model for simulating diazinon runoff in California’s central valley

    Science.gov (United States)

    Joyce, Brian A.; Wallender, Wesley W.; Mailapalli, Damodhara R.

    2010-12-01

    Dormant spray application of pesticides to almond and other stone fruit orchards is the main source of diazinon during the winter in California's central valley. Understanding the pesticide transport and the tradeoffs associated with the various management practices is greatly facilitated by the use of physically-based contaminant transport models. In this study, performance of Joyce's et al. (2008) pesticide transport model was evaluated using experimental data collected from two ground treatments such as resident vegetation and bare soil. The model simulation results obtained in calibration and validation process were analyzed for pesticide concentration and total load. The pesticide transport model accurately predicted the pesticide concentrations and total load in the runoff from bare field and was capable of simulating chemical responses to rainfall-runoff events. In case of resident vegetation, the model results exhibited a larger range of variation than was observed in the bare soil simulations due to increased model parameterization with the addition of foliage and thatch compartments. Furthermore, the model was applied to study the effect of runoff lag time, extent of crop cover, organic content of soil and post-application irrigation on the pesticide peak concentration and total load. Based on the model results, recommendations were suggested to growers prior to implementing certain management decisions to mitigate diazinon transport in the orchard's spray runoff.

  9. A note on estimating urban roof runoff with a forest evaporation model

    NARCIS (Netherlands)

    Gash, J.H.C.; Rosier, P.T.W.; Ragab, R.

    2008-01-01

    A model developed for estimating the evaporation of rainfall intercepted by forest canopies is applied to estimate measurements of the average runoff from the roofs of six houses made in a previous study of hydrological processes in an urban environment. The model is applied using values of the mean

  10. Multi-criteria validation of artificial neural network rainfall-runoff modeling

    Directory of Open Access Journals (Sweden)

    R. Modarres

    2009-03-01

    Full Text Available In this study we propose a comprehensive multi-criteria validation test for rainfall-runoff modeling by artificial neural networks. This study applies 17 global statistics and 3 additional non-parametric tests to evaluate the ANNs. The weakness of global statistics for validation of ANN is demonstrated by rainfall-runoff modeling of the Plasjan Basin in the western region of the Zayandehrud watershed, Iran. Although the global statistics showed that the multi layer perceptron with 4 hidden layers (MLP4 is the best ANN for the basin comparing with other MLP networks and empirical regression model, the non-parametric tests illustrate that neither the ANNs nor the regression model are able to reproduce the probability distribution of observed runoff in validation phase. However, the MLP4 network is the best network to reproduce the mean and variance of the observed runoff based on non-parametric tests. The performance of ANNs and empirical model was also demonstrated for low, medium and high flows. Although the MLP4 network gives the best performance among ANNs for low, medium and high flows based on different statistics, the empirical model shows better results. However, none of the models is able to simulate the frequency distribution of low, medium and high flows according to non-parametric tests. This study illustrates that the modelers should select appropriate and relevant evaluation measures from the set of existing metrics based on the particular requirements of each individual applications.

  11. Rainfall-runoff model for prediction of waterborne viral contamination in a small river catchment

    Science.gov (United States)

    Gelati, E.; Dommar, C.; Lowe, R.; Polcher, J.; Rodó, X.

    2013-12-01

    We present a lumped rainfall-runoff model aimed at providing useful information for the prediction of waterborne viral contamination in small rivers. Viral contamination of water bodies may occur because of the discharge of sewage effluents and of surface runoff over areas affected by animal waste loads. Surface runoff is caused by precipitation that cannot infiltrate due to its intensity and to antecedent soil water content. It may transport animal feces to adjacent water bodies and cause viral contamination. We model streamflow by separating it into two components: subsurface flow, which is produced by infiltrated precipitation; and surface runoff. The model estimates infiltrated and non-infiltrated precipitation and uses impulse-response functions to compute the corresponding fractions of streamflow. The developed methodologies are applied to the Glafkos river, whose catchment extends for 102 km2 and includes the city of Patra. Streamflow and precipitation observations are available at a daily time resolution. Waterborne virus concentration measurements were performed approximately every second week from the beginning of 2011 to mid 2012. Samples were taken at several locations: in river water upstream of Patras and in the urban area; in sea water at the river outlet and approximately 2 km south-west of Patras; in sewage effluents before and after treatment. The rainfall-runoff model was calibrated and validated using observed streamflow and precipitation data. The model contribution to waterborne viral contamination prediction was benchmarked by analyzing the virus concentration measurements together with the estimated surface runoff values. The presented methodology may be a first step towards the development of waterborne viral contamination alert systems. Predicting viral contamination of water bodies would benefit sectors such as water supply and tourism.

  12. Physical design optimization of an urban runoff treatment system using Stormwater Management Model (SWMM).

    Science.gov (United States)

    Tobio, J A S; Maniquiz-Redillas, M C; Kim, L H

    2015-01-01

    The study presented the application of Stormwater Management Model (SWMM) in determining the optimal physical design properties of an established low impact development (LID) system treating road runoff. The calibration of the model was based on monitored storm events occurring from May 2010 to July 2013. It was found that the total suspended solids was highly correlated with stormwater runoff volume and dominant heavy metal constituents in stormwater runoff, such lead, zinc and copper, with a Pearson correlation coefficient ranging from 0.88 to 0.95 (P<0.05). Reducing the original ratio of the storage volume to surface area (SV/SA) of the facility and depth by 25% could match the satisfactory performance efficiency achieved in the original design. The smaller SV/SA and depth would mean a less costly system, signifying the importance of optimization in designing LID systems.

  13. Comparison of Surface Runoff Generation, and Soil and Nutrient Loss in Kakhk Treated and Representative Watersheds, Khorasan Razavi Province

    Directory of Open Access Journals (Sweden)

    Davood Davoodi Moghadam

    2017-02-01

    Full Text Available Introduction: It is vital to control land degradation, for conserving precious natural treasures. Quantification of runoff production and soil and nutrient loss from wild lands under different managerial systems is one of the scientific and optimal management in agriculture and natural resources, as a major component of sustainable development. Many researches have been conducted to assess the effects of different land uses on soil erosion and runoff generation throughout the globe. Most of which, mainly verified the detrimental effects of human intervention on land degradation. However, limited comprehensive and comparative studies have been conducted to consider the amount of surface runoff generation, and soil and nutrient loss from watersheds with different management patterns viz. untreated and treated small watersheds. Materials and Methods: The present study aimed to compare surface runoff generation,soil and nutrient loss in Kakhk treated and untreated watersheds with an area ca. 222 ha and precipitation of some 243 mm per annum. Other physical and geological characteristics of the paired watersheds were also similar to allow assessing the effects of study measures on soil, water and nutrient losses. The area under consideration has been located in Khorasan Razavi Province in northeastern Iran. The present study was performed in plots with standard size of 22.1 × 1.8 m in treating and representative areas, with three replicates and on the storm basis occurred during early 2011 and mid-2014. The treated plots were covered by biological measures viz. seeding, bunching and exclusre. The study plots have been situated on eastern,western and northern aspects with respective slope of 55, 40 and 40 %. The entire runoff from study plots were collected in a container in 0.5×1×1 m. The sediment concentration was also measured in 2-liter samples taken from the container after a complete mixing of the entire collected runoff. The sample was

  14. A Data Stream Model For Runoff Simulation In A Changing Environment

    Science.gov (United States)

    Yang, Q.; Shao, J.; Zhang, H.; Wang, G.

    2017-12-01

    Runoff simulation is of great significance for water engineering design, water disaster control, water resources planning and management in a catchment or region. A large number of methods including concept-based process-driven models and statistic-based data-driven models, have been proposed and widely used in worldwide during past decades. Most existing models assume that the relationship among runoff and its impacting factors is stationary. However, in the changing environment (e.g., climate change, human disturbance), their relationship usually evolves over time. In this study, we propose a data stream model for runoff simulation in a changing environment. Specifically, the proposed model works in three steps: learning a rule set, expansion of a rule, and simulation. The first step is to initialize a rule set. When a new observation arrives, the model will check which rule covers it and then use the rule for simulation. Meanwhile, Page-Hinckley (PH) change detection test is used to monitor the online simulation error of each rule. If a change is detected, the corresponding rule is removed from the rule set. In the second step, for each rule, if it covers more than a given number of instance, the rule is expected to expand. In the third step, a simulation model of each leaf node is learnt with a perceptron without activation function, and is updated with adding a newly incoming observation. Taking Fuxi River catchment as a case study, we applied the model to simulate the monthly runoff in the catchment. Results show that abrupt change is detected in the year of 1997 by using the Page-Hinckley change detection test method, which is consistent with the historic record of flooding. In addition, the model achieves good simulation results with the RMSE of 13.326, and outperforms many established methods. The findings demonstrated that the proposed data stream model provides a promising way to simulate runoff in a changing environment.

  15. A CN-Based Ensembled Hydrological Model for Enhanced Watershed Runoff Prediction

    Directory of Open Access Journals (Sweden)

    Muhammad Ajmal

    2016-01-01

    Full Text Available A major structural inconsistency of the traditional curve number (CN model is its dependence on an unstable fixed initial abstraction, which normally results in sudden jumps in runoff estimation. Likewise, the lack of pre-storm soil moisture accounting (PSMA procedure is another inherent limitation of the model. To circumvent those problems, we used a variable initial abstraction after ensembling the traditional CN model and a French four-parameter (GR4J model to better quantify direct runoff from ungauged watersheds. To mimic the natural rainfall-runoff transformation at the watershed scale, our new parameterization designates intrinsic parameters and uses a simple structure. It exhibited more accurate and consistent results than earlier methods in evaluating data from 39 forest-dominated watersheds, both for small and large watersheds. In addition, based on different performance evaluation indicators, the runoff reproduction results show that the proposed model produced more consistent results for dry, normal, and wet watershed conditions than the other models used in this study.

  16. 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

  17. Integrated watershed management for saturation excess generated runoff, erosion and nutrient control

    Science.gov (United States)

    Understanding the basic hydrology and erosion is vital for effective management and utilization of water resources and soil conservation planning. An important question for judging effectiveness of soil and water conservation practices is whether runoff erosion and nutrient loss is affected by infil...

  18. Comparison of several climate indices as inputs in modelling of the Baltic Sea runoff

    Energy Technology Data Exchange (ETDEWEB)

    Hanninen, J.; Vuorinen, I. [Turku Univ. (Finland). Archipelaco Research Inst.], e-mail: jari.hanninen@utu.fi

    2012-11-01

    Using Transfer function (TF) models, we have earlier presented a chain of events between changes in the North Atlantic Oscillation (NAO) and their oceanographical and ecological consequences in the Baltic Sea. Here we tested whether other climate indices as inputs would improve TF models, and our understanding of the Baltic Sea ecosystem. Besides NAO, the predictors were the Arctic Oscillation (AO), sea-level air pressures at Iceland (SLP), and wind speeds at Hoburg (Gotland). All indices produced good TF models when the total riverine runoff to the Baltic Sea was used as a modelling basis. AO was not applicable in all study areas, showing a delay of about half a year between climate and runoff events, connected with freezing and melting time of ice and snow in the northern catchment area of the Baltic Sea. NAO appeared to be most useful modelling tool as its area of applicability was the widest of the tested indices, and the time lag between climate and runoff events was the shortest. SLP and Hoburg wind speeds showed largely same results as NAO, but with smaller areal applicability. Thus AO and NAO were both mostly contributing to the general understanding of climate control of runoff events in the Baltic Sea ecosystem. (orig.)

  19. Efficiency assessment of runoff harvesting techniques using a 3D coupled surface-subsurface hydrological model

    International Nuclear Information System (INIS)

    Verbist, K.; Cronelis, W. M.; McLaren, R.; Gabriels, D.; Soto, G.

    2009-01-01

    In arid and semi-arid zones runoff harvesting techniques are often applied to increase the water retention and infiltration on steep slopes. Additionally, they act as an erosion control measure to reduce land degradation hazards. Both in literature and in the field, a large variety of runoff collecting systems are found, as well as large variations in design and dimensions. Therefore, detailed measurements were performed on a semi-arid slope in central Chile to allow identification of the effect of a simple water harvesting technique on soil water availability. For this purpose, twenty two TDR-probes were installed and were monitored continuously during and after a simulated rainfall event. These data were used to calibrate the 3D distributed flow model HydroGeoSphere, to assess the runoff components and soil water retention as influenced by the water harvesting technique, both under simulated and natural rainfall conditions. (Author) 6 refs.

  20. Multiobjective training of artificial neural networks for rainfall-runoff modeling

    NARCIS (Netherlands)

    De Vos, N.J.; Rientjes, T.H.M.

    2008-01-01

    This paper presents results on the application of various optimization algorithms for the training of artificial neural network rainfall-runoff models. Multilayered feed-forward networks for forecasting discharge from two mesoscale catchments in different climatic regions have been developed for

  1. The effect of GCM biases on global runoff simulations of a land surface model

    Science.gov (United States)

    Papadimitriou, Lamprini V.; Koutroulis, Aristeidis G.; Grillakis, Manolis G.; Tsanis, Ioannis K.

    2017-09-01

    Global climate model (GCM) outputs feature systematic biases that render them unsuitable for direct use by impact models, especially for hydrological studies. To deal with this issue, many bias correction techniques have been developed to adjust the modelled variables against observations, focusing mainly on precipitation and temperature. However, most state-of-the-art hydrological models require more forcing variables, in addition to precipitation and temperature, such as radiation, humidity, air pressure, and wind speed. The biases in these additional variables can hinder hydrological simulations, but the effect of the bias of each variable is unexplored. Here we examine the effect of GCM biases on historical runoff simulations for each forcing variable individually, using the JULES land surface model set up at the global scale. Based on the quantified effect, we assess which variables should be included in bias correction procedures. To this end, a partial correction bias assessment experiment is conducted, to test the effect of the biases of six climate variables from a set of three GCMs. The effect of the bias of each climate variable individually is quantified by comparing the changes in simulated runoff that correspond to the bias of each tested variable. A methodology for the classification of the effect of biases in four effect categories (ECs), based on the magnitude and sensitivity of runoff changes, is developed and applied. Our results show that, while globally the largest changes in modelled runoff are caused by precipitation and temperature biases, there are regions where runoff is substantially affected by and/or more sensitive to radiation and humidity. Global maps of bias ECs reveal the regions mostly affected by the bias of each variable. Based on our findings, for global-scale applications, bias correction of radiation and humidity, in addition to that of precipitation and temperature, is advised. Finer spatial-scale information is also provided

  2. Dynamic modelling of processes in rivers affected by precipitation runoff

    DEFF Research Database (Denmark)

    Jacobsen, Judith L.

    1997-01-01

    In this thesis, models for the dynamics of oxygen and organic matter in receiving waters (such as rivers and creeks), which are affected by rain, are developed. A time series analysis framework is used, but presented with special emphasis on continuous time state space models. Also, the concept...... analysis methods and model validation tools are employed. To develop the water quality model, including hydraulic relations and the states of oxygen and organic matter, the qualitative concepts of the physical, biological and chemical models are introduced. The model types used in this thesis are one...

  3. Machine Learning and Deep Learning Models to Predict Runoff Water Quantity and Quality

    Science.gov (United States)

    Bradford, S. A.; Liang, J.; Li, W.; Murata, T.; Simunek, J.

    2017-12-01

    Contaminants can be rapidly transported at the soil surface by runoff to surface water bodies. Physically-based models, which are based on the mathematical description of main hydrological processes, are key tools for predicting surface water impairment. Along with physically-based models, data-driven models are becoming increasingly popular for describing the behavior of hydrological and water resources systems since these models can be used to complement or even replace physically based-models. In this presentation we propose a new data-driven model as an alternative to a physically-based overland flow and transport model. First, we have developed a physically-based numerical model to simulate overland flow and contaminant transport (the HYDRUS-1D overland flow module). A large number of numerical simulations were carried out to develop a database containing information about the impact of various input parameters (weather patterns, surface topography, vegetation, soil conditions, contaminants, and best management practices) on runoff water quantity and quality outputs. This database was used to train data-driven models. Three different methods (Neural Networks, Support Vector Machines, and Recurrence Neural Networks) were explored to prepare input- output functional relations. Results demonstrate the ability and limitations of machine learning and deep learning models to predict runoff water quantity and quality.

  4. Streamflow characteristics from modelled runoff time series: Importance of calibration criteria selection

    Science.gov (United States)

    Poole, Sandra; Vis, Marc; Knight, Rodney; Seibert, Jan

    2017-01-01

    Ecologically relevant streamflow characteristics (SFCs) of ungauged catchments are often estimated from simulated runoff of hydrologic models that were originally calibrated on gauged catchments. However, SFC estimates of the gauged donor catchments and subsequently the ungauged catchments can be substantially uncertain when models are calibrated using traditional approaches based on optimization of statistical performance metrics (e.g., Nash–Sutcliffe model efficiency). An improved calibration strategy for gauged catchments is therefore crucial to help reduce the uncertainties of estimated SFCs for ungauged catchments. The aim of this study was to improve SFC estimates from modeled runoff time series in gauged catchments by explicitly including one or several SFCs in the calibration process. Different types of objective functions were defined consisting of the Nash–Sutcliffe model efficiency, single SFCs, or combinations thereof. We calibrated a bucket-type runoff model (HBV – Hydrologiska Byråns Vattenavdelning – model) for 25 catchments in the Tennessee River basin and evaluated the proposed calibration approach on 13 ecologically relevant SFCs representing major flow regime components and different flow conditions. While the model generally tended to underestimate the tested SFCs related to mean and high-flow conditions, SFCs related to low flow were generally overestimated. The highest estimation accuracies were achieved by a SFC-specific model calibration. Estimates of SFCs not included in the calibration process were of similar quality when comparing a multi-SFC calibration approach to a traditional model efficiency calibration. For practical applications, this implies that SFCs should preferably be estimated from targeted runoff model calibration, and modeled estimates need to be carefully interpreted.

  5. Streamflow characteristics from modeled runoff time series - importance of calibration criteria selection

    Science.gov (United States)

    Pool, Sandra; Vis, Marc J. P.; Knight, Rodney R.; Seibert, Jan

    2017-11-01

    Ecologically relevant streamflow characteristics (SFCs) of ungauged catchments are often estimated from simulated runoff of hydrologic models that were originally calibrated on gauged catchments. However, SFC estimates of the gauged donor catchments and subsequently the ungauged catchments can be substantially uncertain when models are calibrated using traditional approaches based on optimization of statistical performance metrics (e.g., Nash-Sutcliffe model efficiency). An improved calibration strategy for gauged catchments is therefore crucial to help reduce the uncertainties of estimated SFCs for ungauged catchments. The aim of this study was to improve SFC estimates from modeled runoff time series in gauged catchments by explicitly including one or several SFCs in the calibration process. Different types of objective functions were defined consisting of the Nash-Sutcliffe model efficiency, single SFCs, or combinations thereof. We calibrated a bucket-type runoff model (HBV - Hydrologiska Byråns Vattenavdelning - model) for 25 catchments in the Tennessee River basin and evaluated the proposed calibration approach on 13 ecologically relevant SFCs representing major flow regime components and different flow conditions. While the model generally tended to underestimate the tested SFCs related to mean and high-flow conditions, SFCs related to low flow were generally overestimated. The highest estimation accuracies were achieved by a SFC-specific model calibration. Estimates of SFCs not included in the calibration process were of similar quality when comparing a multi-SFC calibration approach to a traditional model efficiency calibration. For practical applications, this implies that SFCs should preferably be estimated from targeted runoff model calibration, and modeled estimates need to be carefully interpreted.

  6. Loss Modeling with a Data-Driven Approach in Event-Based Rainfall-Runoff Analysis

    Science.gov (United States)

    Chua, L. H. C.

    2012-04-01

    Mathematical models require the estimation of rainfall abstractions for accurate predictions of runoff. Although loss models such as the constant loss and exponential loss models are commonly used, these methods are based on simplified assumptions of the physical process. A new approach based on the data driven paradigm to estimate rainfall abstractions is proposed in this paper. The proposed data driven model, based on the artificial neural network (ANN) does not make any assumptions on the loss behavior. The estimated discharge from a physically-based model, obtained from the kinematic wave (KW) model assuming zero losses, was used as the only input to the ANN. The output is the measured discharge. Thus, the ANN functions as a black-box loss model. Two sets of data were analyzed for this study. The first dataset consists of rainfall and runoff data, measured from an artificial catchment (area = 25 m2) comprising two overland planes (slope = 11%), 25m long, transversely inclined towards a rectangular channel (slope = 2%) which conveyed the flow, recorded using calibrated weigh tanks, to the outlet. Two rain gauges, each placed 6.25 m from either ends of the channel, were used to record rainfall. Data for six storm events over the period between October 2002 and December 2002 were analyzed. The second dataset was obtained from the Upper Bukit Timah catchment (area = 6.4 km2) instrumented with two rain gauges and a flow measuring station. A total of six events recorded between November 1987 and July 1988 were selected for this study. The runoff predicted by the ANN was compared with the measured runoff. In addition, results from KW models developed for both the catchments were used as a benchmark. The KW models were calibrated assuming the loss rate for an average event for each of the datasets. The results from both the ANN and KW models agreed well with the runoff measured from the artificial catchment. The KW model is expected to perform well since the catchment

  7. Evaluation of the HYMOD model for rainfall–runoff simulation using the GLUE method

    Directory of Open Access Journals (Sweden)

    Z. Quan

    2015-05-01

    Full Text Available The Yalong River is the third largest base of the 13 hydropower bases in China. Long-time series of river discharge records are essential for the design of hydropower stations and water resource management. The existing monitoring network is scarce and cannot provide sufficient hydrological information for the basin. Rainfall–runoff models are popular tools for extending hydrological data in both space and time. In this paper, the feasibility of applying a conceptual rainfall–runoff model, HYdrological MODel (HYMOD, to the upper Yalong River basin was evaluated. The generalized likelihood uncertainty estimation (GLUE was employed for model calibration and uncertainty analysis. The results show that simulated discharge matches the observations satisfactorily, indicating the hydrological model performs well and the application of HYMOD to estimate long time-series of river discharge in the study area is feasible.

  8. Highway runoff quality models for the protection of environmentally sensitive areas

    Science.gov (United States)

    Trenouth, William R.; Gharabaghi, Bahram

    2016-11-01

    This paper presents novel highway runoff quality models using artificial neural networks (ANN) which take into account site-specific highway traffic and seasonal storm event meteorological factors to predict the event mean concentration (EMC) statistics and mean daily unit area load (MDUAL) statistics of common highway pollutants for the design of roadside ditch treatment systems (RDTS) to protect sensitive receiving environs. A dataset of 940 monitored highway runoff events from fourteen sites located in five countries (Canada, USA, Australia, New Zealand, and China) was compiled and used to develop ANN models for the prediction of highway runoff suspended solids (TSS) seasonal EMC statistical distribution parameters, as well as the MDUAL statistics for four different heavy metal species (Cu, Zn, Cr and Pb). TSS EMCs are needed to estimate the minimum required removal efficiency of the RDTS needed in order to improve highway runoff quality to meet applicable standards and MDUALs are needed to calculate the minimum required capacity of the RDTS to ensure performance longevity.

  9. Spatio-temporal precipitation error propagation in runoff modelling: a case study in central Sweden

    Directory of Open Access Journals (Sweden)

    J. Olsson

    2006-01-01

    Full Text Available The propagation of spatio-temporal errors in precipitation estimates to runoff errors in the output from the conceptual hydrological HBV model was investigated. The study region was the Gimån catchment in central Sweden, and the period year 2002. Five precipitation sources were considered: NWP model (H22, weather radar (RAD, precipitation gauges (PTH, and two versions of a mesoscale analysis system (M11, M22. To define the baseline estimates of precipitation and runoff, used to define seasonal precipitation and runoff biases, the mesoscale climate analysis M11 was used. The main precipitation biases were a systematic overestimation of precipitation by H22, in particular during winter and early spring, and a pronounced local overestimation by RAD during autumn, in the western part of the catchment. These overestimations in some cases exceeded 50% in terms of seasonal subcatchment relative accumulated volume bias, but generally the bias was within ±20%. The precipitation data from the different sources were used to drive the HBV model, set up and calibrated for two stations in Gimån, both for continuous simulation during 2002 and for forecasting of the spring flood peak. In summer, autumn and winter all sources agreed well. In spring H22 overestimated the accumulated runoff volume by ~50% and peak discharge by almost 100%, owing to both overestimated snow depth and precipitation during the spring flood. PTH overestimated spring runoff volumes by ~15% owing to overestimated winter precipitation. The results demonstrate how biases in precipitation estimates may exhibit a substantial space-time variability, and may further become either magnified or reduced when applied for hydrological purposes, depending on both temporal and spatial variations in the catchment. Thus, the uncertainty in precipitation estimates should preferably be specified as a function of both time and space.

  10. The sensitivity of catchment runoff models to rainfall data at different spatial scales

    Directory of Open Access Journals (Sweden)

    V. A. Bell

    2000-01-01

    Full Text Available The sensitivity of catchment runoff models to rainfall is investigated at a variety of spatial scales using data from a dense raingauge network and weather radar. These data form part of the HYREX (HYdrological Radar EXperiment dataset. They encompass records from 49 raingauges over the 135 km2 Brue catchment in south-west England together with 2 and 5 km grid-square radar data. Separate rainfall time-series for the radar and raingauge data are constructed on 2, 5 and 10 km grids, and as catchment average values, at a 15 minute time-step. The sensitivity of the catchment runoff models to these grid scales of input data is evaluated on selected convective and stratiform rainfall events. Each rainfall time-series is used to produce an ensemble of modelled hydrographs in order to investigate this sensitivity. The distributed model is shown to be sensitive to the locations of the raingauges within the catchment and hence to the spatial variability of rainfall over the catchment. Runoff sensitivity is strongest during convective rainfall when a broader spread of modelled hydrographs results, with twice the variability of that arising from stratiform rain. Sensitivity to rainfall data and model resolution is explored and, surprisingly, best performance is obtained using a lower resolution of rainfall data and model. Results from the distributed catchment model, the Simple Grid Model, are compared with those obtained from a lumped model, the PDM. Performance from the distributed model is found to be only marginally better during stratiform rain (R2 of 0.922 compared to 0.911 but significantly better during convective rain (R2 of 0.953 compared to 0.909. The improved performance from the distributed model can, in part, be accredited to the excellence of the dense raingauge network which would not be the norm for operational flood warning systems. In the final part of the paper, the effect of rainfall resolution on the performance of the 2 km distributed

  11. Multiscale soil moisture measurement for mapping surface runoff generation on torrential headwater catchments (Draix-Bléone field observatory, South Alps, France)

    Science.gov (United States)

    Florian, Mallet; Vincent, Marc; Johnny, Douvinet; Philippe, Rossello; Bouteiller Caroline, Le; Jean-Philippe, Malet; Julien, Gance

    2015-04-01

    soilwater flow of from the surface to - 30 cm. Another distributed approach will be carried out from a measurement of cosmic neutrons mitigation (Cosmic ray sensor) to estimate a soil moisture averaged value over 40 ha (Zreda et al., 2012). Finally, the smallest scale (slope and catchment) will be approached using remote sensing with a drone and/or satellite imagery (IR, passive and active microwave). This concatenation of scales with different combinations of time steps should enable us to better understand the hydrological dynamics in torrential environments. It aims at mapping the stormflow generation on a catchment at the flood scale and defining the main determinants of surface runoff. These results may contribute to the improvement of runoff simulation and flood prediction. References : Uhlenbrook S., J.J. McDonnell and C. Leibundgut, 2003. Preface: Runoff generation implications for river basin modelling. Hydrological Processes, Special Issue, 17: 197-198. Andrew W. Western, Sen-Lin Zhou, Rodger B. Grayson, Thomas A. MacMahon, Günter Blöshl, David J. Wilson, 2004. Spatial correlation of soil moisture in small catchments and its relationship to dominant spatial hydrological processes. Journal of Hydrology 286. Zreda, M., Shuttleworth WJ., Zeng X., Zweck C., Desilets D., Franz TE. et al., 2012. COSMOS: the COsmic-ray Soil Moisture Observing System. Hydrology and Earth System Sciences, 16(11): 4079-4099.

  12. Model-based monitoring of stormwater runoff quality

    DEFF Research Database (Denmark)

    Birch, Heidi; Vezzaro, Luca; Mikkelsen, Peter Steen

    2013-01-01

    Monitoring of micropollutants (MP) in stormwater is essential to evaluate the impacts of stormwater on the receiving aquatic environment. The aim of this study was to investigate how different strategies for monitoring of stormwater quality (combining a model with field sampling) affect...... the information obtained about MP discharged from the monitored system. A dynamic stormwater quality model was calibrated using MP data collected by automatic volume-proportional sampling and passive sampling in a storm drainage system on the outskirts of Copenhagen (Denmark) and a 10-year rain series was used......) for calibration of the model, resulted in the same predicted level but with narrower model prediction bounds than by using volume-proportional samples for calibration. This shows that passive sampling allows for a better exploitation of the resources allocated for stormwater quality monitoring....

  13. Using Runoff Data to Calibrate the Community Land Model

    Science.gov (United States)

    Ray, J.; Hou, Z.; Huang, M.; Swiler, L.

    2014-12-01

    We present a statistical method for calibrating the Community Land Model (CLM) using streamflow observations collected between 1999 and 2008 at the outlet of two river basins from the Model Parameter Estimation Experiment (MOPEX), Oostanaula River at Resaca GA, and Walnut River at Winfield KS.. The observed streamflow shows variability over a large range of time-scales, none of which significantly dominates the others; consequently, the time-series seems noisy and is difficult to be directly used in model parameter estimation efforts without significant filtering. We perform a multi-resolution wavelet decomposition of the observed streamflow, and use the wavelet power coefficients (WPC) as the tuning data. We construct a mapping (a surrogate model) between WPC and three hydrological parameters of the CLM using a training set of 256 CLM runs. The dependence of WPC on the parameters is complex and cannot be captured using a surrogate unless the parameter combinations yield physically plausible model predictions, i.e., those that are skillful when compared to observations. Retaining only the top quartile of the runs ensures skillfulness, as measured by the RMS error between observations and CLM predictions. This "screening" of the training data yields a region (the "valid" region) in the parameter space where accurate surrogate models can be created. We construct a classifier for the "valid" region, and, in conjunction with the surrogate models for WPC, pose a Bayesian inverse problem for the three hydrological parameters. The inverse problem is solved using an adaptive Markov chain Monte Carlo (MCMC) method to construct a three-dimensional posterior distribution for the hydrological parameters. Posterior predictive tests using the surrogate model reveal that the posterior distribution is more predictive than the nominal values of the parameters, which are used as default values in the current version of CLM. The effectiveness of the inversion is then validated by

  14. A novel approach for runoff modelling in ungauged catchments by Catchment Morphing

    Science.gov (United States)

    Zhang, J.; Han, D.

    2017-12-01

    Runoff prediction in ungauged catchments has been one of the major challenges in the past decades. However, due to the tremendous heterogeneity of hydrological catchments, obstacles exist in deducing model parameters for ungauged catchments from gauged ones. We propose a novel approach to predict ungauged runoff with Catchment Morphing (CM) using a fully distributed model. CM is defined as by changing the catchment characteristics (area and slope here) from the baseline model built with a gauged catchment to model the ungauged ones. The advantages of CM are: (a) less demand of the similarity between the baseline catchment and the ungauged catchment, (b) less demand of available data, and (c) potentially applicable in varied catchments. A case study on seven catchments in the UK has been used to demonstrate the proposed scheme. To comprehensively examine the CM approach, distributed rainfall inputs are utilised in the model, and fractal landscapes are used to morph the land surface from the baseline model to the target model. The preliminary results demonstrate the feasibility of the approach, which is promising in runoff simulation for ungauged catchments. Clearly, more work beyond this pilot study is needed to explore and develop this new approach further to maturity by the hydrological community.

  15. Development of Rainfall-runoff Model Using Tank Model: Problems and Challenges in Province of Aceh, Indonesia

    Directory of Open Access Journals (Sweden)

    Hairul Basri

    2013-04-01

    Full Text Available Rainfall-runoff model using tank model founded by Sugawara has been widely used in Asia. Many researchers use the tank model to predict water availability and flooding in a watershed. This paper describes the concept of rainfall-runoff model using tank model, discuss the problems and challenges in using of the model, especially in Province of Aceh, Indonesia and how to improve the outcome of simulation of tank model. Many factors affect the rainfall-runoff phenomena of a wide range of watershed include: soil types, land use types, rainfall, morphometry, geology and geomorphology, caused the tank model usefull only for concerning watershed. It is necessary to adjust some parameters of tank model for other watershed by recalibrating the parameters of the model. Rainfall runoff model using the tank model for a watershed scale is more reasonable focused on each sub-watershed by considering soil types, land use types and rainfall of the concerning watershed. Land use data can be enhanced by using landsat imagery or aerial photographs to support the validation the existing of land use type. Long term of observed discharges and rainfall data should be increased by set up the AWLR (Automatic Water Level Recorder and rainfall stations for each of sub-watersheds. The reasonable tank model can be resulted not only by calibrating the parameters, but also by considering the observed and simulated infiltration for each soil and land use types of the concerning watershed

  16. WEPP and ANN models for simulating soil loss and runoff in a semi-arid Mediterranean region.

    Science.gov (United States)

    Albaradeyia, Issa; Hani, Azzedine; Shahrour, Isam

    2011-09-01

    This paper presents the use of both the Water Erosion Prediction Project (WEPP) and the artificial neural network (ANN) for the prediction of runoff and soil loss in the central highland mountainous of the Palestinian territories. Analyses show that the soil erosion is highly dependent on both the rainfall depth and the rainfall event duration rather than on the rainfall intensity as mostly mentioned in the literature. The results obtained from the WEPP model for the soil loss and runoff disagree with the field data. The WEPP underestimates both the runoff and soil loss. Analyses conducted with the ANN agree well with the observation. In addition, the global network models developed using the data of all the land use type show a relatively unbiased estimation for both runoff and soil loss. The study showed that the ANN model could be used as a management tool for predicting runoff and soil loss.

  17. Hydrologic Variations and Stochastic Modeling of Runoff in Zoige Wetland in the Eastern Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Guanghua Qin

    2015-01-01

    Full Text Available Hydrological time series data (1988–2008 of the Hei River, the main water source to Zoige wetland in the Eastern Tibetan Plateau, were investigated. Results showed that the runoff distribution of Hei River varies with the relative change in amplitude (Cm=15.9 and the absolute change in amplitude (ΔQ=37.1 m3/s during the year. There was a significant decreasing trend since 1988 with annual runoff of 20.0 m3/s (1988–1994, 19.0 m3/s (1995–2000, and 15.2 m3/s (2001–2008. There were double peaks in runoff during the water year: the highest peak in the period of 1988–2000 occurred in July while in the period of 2001–2008 it occurred in October. Shifting peak flow means less water quantity in wetland during growing season. Nearest neighbor bootstrapping regressive method was used to predict daily runoff of the Hei River. Model results show that it was fitted with 94.23% of R2 for daily time series, which can provide a basis for the development and utilization of regional water resources.

  18. Sensitivity of Drought Processes to Runoff Parameterizations in East Asia with the Community Land Model

    Science.gov (United States)

    Kim, J. B.; Um, M. J.; Kim, Y.

    2016-12-01

    Drought is one of the most powerful and extensive disasters and has the highest annual average damage among all the disasters. Focusing on East Asia, where over one fifth of all the people in the world live, drought has impacted as well as been projected to impact the region significantly. .Therefore it is critical to reasonably simulate the drought phenomenon in the region and thus this study would focus on the reproducibility of drought with the NCAR CLM. In this study, we examine the propagation of drought processes with different runoff parameterization of CLM in East Asia. Two different schemes are used; TOPMODEL-based and VIC-based schemes, which differentiate the result of runoff through the surface and subsurface runoff parameterization. CLM with different runoff scheme are driven with two atmospheric forcings from CRU/NCEP and NCEP reanalysis data. Specifically, propagation of drought from meteorological, agricultural to hydrologic drought is investigated with different drought indices, estimated with not only model simulated results but also observational data. The indices include the standardized precipitation evapotranspiration index (SPEI), standardized runoff index (SRI) and standardized soil moisture index (SSMI). Based on these indices, the drought characteristics such as intensity, frequency and spatial extent are investigated. At last, such drought assessments would reveal the possible model deficiencies in East Asia. AcknowledgementsThis work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (2015R1C1A2A01054800) and the Korea Meteorological Administration R&D Program under Grant KMIPA 2015-6180.

  19. Real Time Updating in Distributed Urban Rainfall Runoff Modelling

    DEFF Research Database (Denmark)

    Borup, Morten; Madsen, Henrik

    are equipped with basins and automated structures that allow for a large degree of control of the systems, but in order to do this optimally it is required to know what is happening throughout the system. For this task models are needed, due to the large scale and complex nature of the systems. The physically...... that are being updated from system measurements was studied. The results showed that the fact alone that it takes time for rainfall data to travel the distance between gauges and catchments has such a big negative effect on the forecast skill of updated models, that it can justify the choice of even very...... when it was used to update the water level in multiple upstream basins. This method is, however, not capable of utilising the spatial correlations in the errors to correct larger parts of the models. To accommodate this a method was developed for correcting the slow changing inflows to urban drainage...

  20. Auxiliary Deep Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae

    2016-01-01

    Deep generative models parameterized by neural networks have recently achieved state-of-the-art performance in unsupervised and semi-supervised learning. We extend deep generative models with auxiliary variables which improves the variational approximation. The auxiliary variables leave...... faster with better results. We show state-of-the-art performance within semi-supervised learning on MNIST (0.96%), SVHN (16.61%) and NORB (9.40%) datasets....

  1. Retrospective Analysis of Recent Flood Events With Persistent High Surface Runoff From Hydrological Modelling

    Science.gov (United States)

    Joshi, S.; Hakeem, K. Abdul; Raju, P. V.; Rao, V. V.; Yadav, A.; Diwakar, P. G.; Dadhwal, V. K.

    2014-11-01

    Floods are one of the most common and widespread disasters in India, with an estimated 40Mha of land prone to this natural disaster (National Flood Commission, India). Significant loss of property, infrastructure, livestock, public utilities resulting in large economic losses due to floods are recurrent every year in many parts of India. Flood forecasting and early warning is widely recognized and adopted as non-structural measure to lower the damages caused by the flood events. Estimating the rainfall excess that results into excessive river flow is preliminary effort in riverine flood estimation. Flood forecasting models are in general, are event based and do not fully account for successive and persistent excessive surface runoff conditions. Successive high rainfall events result in saturated soil moisture conditions, favourable for high surface runoff conditions. The present study is to explore the usefulness of hydrological model derived surface runoff, running on continuous times-step, to relate to the occurrence of flood inundation due to persistent and successive high surface runoff conditions. Variable Infiltration Capacity (VIC), a macro-scale hydrological model, was used to simulate daily runoff at systematic grid level incorporating daily meteorological data and land cover data. VIC is a physically based, semi-distributed macroscale hydrological model that represents surface and subsurface hydrologic process on spatially distributed grid cell. It explicitly represents sub-grid heterogeneity in land cover classes, taking their phenological changes into account. In this study, the model was setup for entire India using geo-spatial data available from multiple sources (NRSC, NBSS&LUP, NOAA, and IMD) and was calibrated with river discharge data from CWC at selected river basins. Using the grid-wise surface runoff estimates from the model, an algorithm was developed through a set of thresholds of successive high runoff values in order to identify grids

  2. Assessing the polycyclic aromatic hydrocarbon (PAH) pollution of urban stormwater runoff: a dynamic modeling approach.

    Science.gov (United States)

    Zheng, Yi; Lin, Zhongrong; Li, Hao; Ge, Yan; Zhang, Wei; Ye, Youbin; Wang, Xuejun

    2014-05-15

    Urban stormwater runoff delivers a significant amount of polycyclic aromatic hydrocarbons (PAHs), mostly of atmospheric origin, to receiving water bodies. The PAH pollution of urban stormwater runoff poses serious risk to aquatic life and human health, but has been overlooked by environmental modeling and management. This study proposed a dynamic modeling approach for assessing the PAH pollution and its associated environmental risk. A variable time-step model was developed to simulate the continuous cycles of pollutant buildup and washoff. To reflect the complex interaction among different environmental media (i.e. atmosphere, dust and stormwater), the dependence of the pollution level on antecedent weather conditions was investigated and embodied in the model. Long-term simulations of the model can be efficiently performed, and probabilistic features of the pollution level and its risk can be easily determined. The applicability of this approach and its value to environmental management was demonstrated by a case study in Beijing, China. The results showed that Beijing's PAH pollution of road runoff is relatively severe, and its associated risk exhibits notable seasonal variation. The current sweeping practice is effective in mitigating the pollution, but the effectiveness is both weather-dependent and compound-dependent. The proposed modeling approach can help identify critical timing and major pollutants for monitoring, assessing and controlling efforts to be focused on. The approach is extendable to other urban areas, as well as to other contaminants with similar fate and transport as PAHs. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Innovative use of soft data for the validation of a rainfall-runoff model forced by remote sensing data

    Science.gov (United States)

    van Emmerik, Tim; Eilander, Dirk; Piet, Marijn; Mulder, Gert

    2013-04-01

    The Chamcar Bei catchment in southern Cambodia is a typical ungauged basin. Neither meteorological data or discharge measurements are available. In this catchment, local farmers are highly dependent on the irrigation system. However, due to the unreliability of the water supply, it was required to make a hydrological model, with which further improvements of the irrigation system could be planned. First, we used knowledge generated in the IAHS decade on Predictions in Ungauged Basins (PUB) to estimate the annual water balance of the Chamcar Bei catchment. Next, using remotely sensed precipitation, vegetation, elevation and transpiration data, a monthly rainfall-runoff model has been developed. The rainfall-runoff model was linked to the irrigation system reservoir, which allowed to validate the model based on soft data such as historical knowledge of the reservoir water level and groundwater levels visible in wells. This study shows that combining existing remote sensing data and soft ground data can lead to useful modeling results. The approach presented in this study can be applied in other ungauged basins, which can be extremely helpful in managing water resources in developing countries.

  4. Assessment of Noah model physics and various runoff parameterizations over a Tibetan River

    Science.gov (United States)

    Zheng, Donghai; van der Velde, Rogier; Su, Zhongbo; Wen, Jun; Wang, Xin

    2017-04-01

    Noah model physics options validated for the source region of the Yellow River (SRYR) are applied to investigate their ability in reproducing runoff at the catchment scale. Three sets of augmentations are implemented affecting the descriptions of i) turbulent and soil heat transport (Noah-H), ii) soil water flow (Noah-W) and iii) frozen ground processes (Noah-F). Five numerical experiments are designed with the three augmented versions, a control run with default model physics and a run with all augmentations (Noah-A). Further, runoff parameterizations currently adopted by the i) Noah-MP model, ii) Community Land Model (CLM), and iii) CLM with variable infiltration capacity hydrology (CLM-VIC) are incorporated into the structure of Noah-A, and four additional numerical experiments are designed with the three aforementioned and the default Noah runoff parameterizations within the Noah-A. Each experiment is forced with 0.1o atmospheric forcing data from Institute of Tibetan Plateau Research, with vegetation and soil parameters adopted from Weather Research and Forecasting dataset and China Soil Database. In addition, the Community Earth System Model database provides the maximum surface saturated area parameter for the Noah-MP and CLM parameterizations. Each model run is initialized using a single-year recurrent spin-up to achieve the equilibrium model states. The results highlight that i) a complete description of vertical heat and water exchanges is necessary to correctly simulate the runoff at the catchment scale, and ii) the soil water storage-based parameterizations (Noah-A and CLM-VIC) outperform the groundwater table-based parameterizations (Noah-MP and CLM) in the seasonally frozen and high altitude SRYR.

  5. RAINFALL-RUNOFF MODELING IN THE TURKEY RIVER USING ...

    African Journals Online (AJOL)

    2015-01-15

    Jan 15, 2015 ... Comparison of observed and simulated data. 3.2. Regression modeling. Equations 4 to 9 show the results of linear regression using different input data. These equations were obtained by using the SPSS software. The released statistical parameters due to regression analysis have been showed in table 5.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 122; Issue 2. Using artificial neural network approach for modelling ... Nevertheless, water level and flow records are essential in hydrological analysis for designing related water works of flood management. Due to the complexity of the hydrological process, ...

  7. Description of the National Hydrologic Model for use with the Precipitation-Runoff Modeling System (PRMS)

    Science.gov (United States)

    Regan, R. Steven; Markstrom, Steven L.; Hay, Lauren E.; Viger, Roland J.; Norton, Parker A.; Driscoll, Jessica M.; LaFontaine, Jacob H.

    2018-01-08

    This report documents several components of the U.S. Geological Survey National Hydrologic Model of the conterminous United States for use with the Precipitation-Runoff Modeling System (PRMS). It provides descriptions of the (1) National Hydrologic Model, (2) Geospatial Fabric for National Hydrologic Modeling, (3) PRMS hydrologic simulation code, (4) parameters and estimation methods used to compute spatially and temporally distributed default values as required by PRMS, (5) National Hydrologic Model Parameter Database, and (6) model extraction tool named Bandit. The National Hydrologic Model Parameter Database contains values for all PRMS parameters used in the National Hydrologic Model. The methods and national datasets used to estimate all the PRMS parameters are described. Some parameter values are derived from characteristics of topography, land cover, soils, geology, and hydrography using traditional Geographic Information System methods. Other parameters are set to long-established default values and computation of initial values. Additionally, methods (statistical, sensitivity, calibration, and algebraic) were developed to compute parameter values on the basis of a variety of nationally-consistent datasets. Values in the National Hydrologic Model Parameter Database can periodically be updated on the basis of new parameter estimation methods and as additional national datasets become available. A companion ScienceBase resource provides a set of static parameter values as well as images of spatially-distributed parameters associated with PRMS states and fluxes for each Hydrologic Response Unit across the conterminuous United States.

  8. Quantitative comparison of initial soil erosion processes and runoff generation in Spanish and German vineyards.

    Science.gov (United States)

    Rodrigo Comino, J; Iserloh, T; Lassu, T; Cerdà, A; Keestra, S D; Prosdocimi, M; Brings, C; Marzen, M; Ramos, M C; Senciales, J M; Ruiz Sinoga, J D; Seeger, M; Ries, J B

    2016-09-15

    The aim of this study was to enable a quantitative comparison of initial soil erosion processes in European vineyards using the same methodology and equipment. The study was conducted in four viticultural areas with different characteristics (Valencia and Málaga in Spain, Ruwer-Mosel valley and Saar-Mosel valley in Germany). Old and young vineyards, with conventional and ecological planting and management systems were compared. The same portable rainfall simulator with identical rainfall intensity (40mmh(-1)) and sampling intervals (30min of test duration, collecting the samples at 5-min-intervals) was used over a circular test plot with 0.28m(2). The results of 83 simulations have been analysed and correlation coefficients were calculated for each study area to identify the relationship between environmental plot characteristics, soil texture, soil erosion, runoff and infiltration. The results allow for identification of the main factors related to soil properties, topography and management, which control soil erosion processes in vineyards. The most important factors influencing soil erosion and runoff were the vegetation cover for the ecological German vineyards (with 97.6±8% infiltration coefficients) and stone cover, soil moisture and slope steepness for the conventional land uses. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Event-based rainfall-runoff modelling of the Kelantan River Basin

    Science.gov (United States)

    Basarudin, Z.; Adnan, N. A.; Latif, A. R. A.; Tahir, W.; Syafiqah, N.

    2014-02-01

    Flood is one of the most common natural disasters in Malaysia. According to hydrologists there are many causes that contribute to flood events. The two most dominant factors are the meteorology factor (i.e climate change) and change in land use. These two factors contributed to floods in recent decade especially in the monsoonal catchment such as Malaysia. This paper intends to quantify the influence of rainfall during extreme rainfall events on the hydrological model in the Kelantan River catchment. Therefore, two dynamic inputs were used in the study: rainfall and river discharge. The extreme flood events in 2008 and 2004 were compared based on rainfall data for both years. The events were modeled via a semi-distributed HEC-HMS hydrological model. Land use change was not incorporated in the study because the study only tries to quantify rainfall changes during these two events to simulate the discharge and runoff value. Therefore, the land use data representing the year 2004 were used as inputs in the 2008 runoff model. The study managed to demonstrate that rainfall change has a significant impact to determine the peak discharge and runoff depth for the study area.

  10. Event-based rainfall-runoff modelling of the Kelantan River Basin

    International Nuclear Information System (INIS)

    Basarudin, Z; Adnan, N A; Latif, A R A; Syafiqah, N; Tahir, W

    2014-01-01

    Flood is one of the most common natural disasters in Malaysia. According to hydrologists there are many causes that contribute to flood events. The two most dominant factors are the meteorology factor (i.e climate change) and change in land use. These two factors contributed to floods in recent decade especially in the monsoonal catchment such as Malaysia. This paper intends to quantify the influence of rainfall during extreme rainfall events on the hydrological model in the Kelantan River catchment. Therefore, two dynamic inputs were used in the study: rainfall and river discharge. The extreme flood events in 2008 and 2004 were compared based on rainfall data for both years. The events were modeled via a semi-distributed HEC-HMS hydrological model. Land use change was not incorporated in the study because the study only tries to quantify rainfall changes during these two events to simulate the discharge and runoff value. Therefore, the land use data representing the year 2004 were used as inputs in the 2008 runoff model. The study managed to demonstrate that rainfall change has a significant impact to determine the peak discharge and runoff depth for the study area

  11. An investigation of the effect of hysteresis in a simple rainfall-runoff model

    Science.gov (United States)

    Flynn, D. P.; O'Kane, J. P.

    2009-04-01

    Multiphase porous media such as soils are known to exhibit hysteresis, e.g. in soils there is a strong hysteretic relationship between the moisture content and the matric potential and to date the Preisach model has been successful in modelling this relationship. Subsequently ODEs with Preisach hysteresis have been developed, such as a hysteretic version of Darcy's law and a hysteretic version of the linear reservoir known as the Preisach reservoir. In this paper we combine the above Hysteretic Differential Equations (HDEs) with three linear reservoirs so as to develop a simple rainfall runoff model. The model can be represented by a block diagram: Rainfall q(t) enters the soil component and either infiltrates and/or runs off when it exceeds the maximum rate of infiltration. The runoff part is fed into two linear reservoirs in series. Next, the drainage from the soil to groundwater is represented by a single linear reservoir, where the output from the soil becomes the input to the ground reservoir and vice-versa for capillary rise. Finally the groundwater and surface runoff are combined at some point and contribute to the total outflow from the catchment. Finally we investigate the effects of hysteresis in this system and compare it to the non-hysteretic case.

  12. Comparison of two stochastic techniques for reliable urban runoff prediction by modeling systematic errors

    DEFF Research Database (Denmark)

    Del Giudice, Dario; Löwe, Roland; Madsen, Henrik

    2015-01-01

    In urban rainfall-runoff, commonly applied statistical techniques for uncertainty quantification mostly ignore systematic output errors originating from simplified models and erroneous inputs. Consequently, the resulting predictive uncertainty is often unreliable. Our objective is to present two ....... These properties make it more suitable for off-line applications. The IND can help in diagnosing the causes of output errors and is computationally inexpensive. It produces best results on short forecast horizons that are typical for online applications.......In urban rainfall-runoff, commonly applied statistical techniques for uncertainty quantification mostly ignore systematic output errors originating from simplified models and erroneous inputs. Consequently, the resulting predictive uncertainty is often unreliable. Our objective is to present two...

  13. Evaluating the Hydrologic Sensitivities of Three Land Surface Models to Bound Uncertainties in Runoff Projections

    Science.gov (United States)

    Chiao, T.; Nijssen, B.; Stickel, L.; Lettenmaier, D. P.

    2013-12-01

    Hydrologic modeling is often used to assess the potential impacts of climate change on water availability and quality. A common approach in these studies is to calibrate the selected model(s) to reproduce historic stream flows prior to the application of future climate projections. This approach relies on the implicit assumptions that the sensitivities of these models to meteorological fluctuations will remain relatively constant under climate change and that these sensitivities are similar among models if all models are calibrated to the same historic record. However, even if the models are able to capture the historic variability in hydrological variables, differences in model structure and parameter estimation contribute to the uncertainties in projected runoff, which confounds the incorporation of these results into water resource management decision-making. A better understanding of the variability in hydrologic sensitivities between different models can aid in bounding this uncertainty. In this research, we characterized the hydrologic sensitivities of three watershed-scale land surface models through a case study of the Bull Run watershed in Northern Oregon. The Distributed Hydrology Soil Vegetation Model (DHSVM), Precipitation-Runoff Modeling System (PRMS), and Variable Infiltration Capacity model (VIC) were implemented and calibrated individually to historic streamflow using a common set of long-term, gridded forcings. In addition to analyzing model performances for a historic period, we quantified the temperature sensitivity (defined as change in runoff in response to change in temperature) and precipitation elasticity (defined as change in runoff in response to change in precipitation) of these three models via perturbation of the historic climate record using synthetic experiments. By comparing how these three models respond to changes in climate forcings, this research aims to test the assumption of constant and similar hydrologic sensitivities. Our

  14. Bayesian analysis of data and model error in rainfall-runoff hydrological models

    Science.gov (United States)

    Kavetski, D.; Franks, S. W.; Kuczera, G.

    2004-12-01

    A major unresolved issue in the identification and use of conceptual hydrologic models is realistic description of uncertainty in the data and model structure. In particular, hydrologic parameters often cannot be measured directly and must be inferred (calibrated) from observed forcing/response data (typically, rainfall and runoff). However, rainfall varies significantly in space and time, yet is often estimated from sparse gauge networks. Recent work showed that current calibration methods (e.g., standard least squares, multi-objective calibration, generalized likelihood uncertainty estimation) ignore forcing uncertainty and assume that the rainfall is known exactly. Consequently, they can yield strongly biased and misleading parameter estimates. This deficiency confounds attempts to reliably test model hypotheses, to generalize results across catchments (the regionalization problem) and to quantify predictive uncertainty when the hydrologic model is extrapolated. This paper continues the development of a Bayesian total error analysis (BATEA) methodology for the calibration and identification of hydrologic models, which explicitly incorporates the uncertainty in both the forcing and response data, and allows systematic model comparison based on residual model errors and formal Bayesian hypothesis testing (e.g., using Bayes factors). BATEA is based on explicit stochastic models for both forcing and response uncertainty, whereas current techniques focus solely on response errors. Hence, unlike existing methods, the BATEA parameter equations directly reflect the modeler's confidence in all the data. We compare several approaches to approximating the parameter distributions: a) full Markov Chain Monte Carlo methods and b) simplified approaches based on linear approximations. Studies using synthetic and real data from the US and Australia show that BATEA systematically reduces the parameter bias, leads to more meaningful model fits and allows model comparison taking

  15. Integration of aspect and slope in snowmelt runoff modeling in a mountain watershed

    Directory of Open Access Journals (Sweden)

    Shalamu Abudu

    2016-10-01

    Full Text Available This study assessed the performances of the traditional temperature-index snowmelt runoff model (SRM and an SRM model with a finer zonation based on aspect and slope (SRM + AS model in a data-scarce mountain watershed in the Urumqi River Basin, in Northwest China. The proposed SRM + AS model was used to estimate the melt rate with the degree-day factor (DDF through the division of watershed elevation zones based on aspect and slope. The simulation results of the SRM + AS model were compared with those of the traditional SRM model to identify the improvements of the SRM + AS model's performance with consideration of topographic features of the watershed. The results show that the performance of the SRM + AS model has improved slightly compared to that of the SRM model. The coefficients of determination increased from 0.73, 0.69, and 0.79 with the SRM model to 0.76, 0.76, and 0.81 with the SRM + AS model during the simulation and validation periods in 2005, 2006, and 2007, respectively. The proposed SRM + AS model that considers aspect and slope can improve the accuracy of snowmelt runoff simulation compared to the traditional SRM model in mountain watersheds in arid regions by proper parameterization, careful input data selection, and data preparation.

  16. Technical note: Cascade of submerged reservoirs as a rainfall-runoff model

    Science.gov (United States)

    Kurnatowski, Jacek

    2017-09-01

    The rainfall-runoff conceptual model as a cascade of submerged linear reservoirs with particular outflows depending on storages of adjoining reservoirs is developed. The model output contains different exponential functions with roots of Chebyshev polynomials of the first kind as exponents. The model is applied to instantaneous unit hydrograph (IUH) and recession curve problems and compared with the analogous results of the Nash cascade. A case study is performed on a basis of 46 recession periods. Obtained results show the usefulness of the model as an alternative concept to the Nash cascade.

  17. Multi-Site Calibration of Linear Reservoir Based Geomorphologic Rainfall-Runoff Models

    Directory of Open Access Journals (Sweden)

    Bahram Saeidifarzad

    2014-09-01

    Full Text Available Multi-site optimization of two adapted event-based geomorphologic rainfall-runoff models was presented using Non-dominated Sorting Genetic Algorithm (NSGA-II method for the South Fork Eel River watershed, California. The first model was developed based on Unequal Cascade of Reservoirs (UECR and the second model was presented as a modified version of Geomorphological Unit Hydrograph based on Nash’s model (GUHN. Two calibration strategies were considered as semi-lumped and semi-distributed for imposing (or unimposing the geomorphology relations in the models. The results of models were compared with Nash’s model. Obtained results using the observed data of two stations in the multi-site optimization framework showed reasonable efficiency values in both the calibration and the verification steps. The outcomes also showed that semi-distributed calibration of the modified GUHN model slightly outperformed other models in both upstream and downstream stations during calibration. Both calibration strategies for the developed UECR model during the verification phase showed slightly better performance in the downstream station, but in the upstream station, the modified GUHN model in the semi-lumped strategy slightly outperformed the other models. The semi-lumped calibration strategy could lead to logical lag time parameters related to the basin geomorphology and may be more suitable for data-based statistical analyses of the rainfall-runoff process.

  18. A simple rainfall-runoff model for the single and long term hydrological performance of green roofs

    DEFF Research Database (Denmark)

    Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen

    Green roofs are being widely implemented for storm water control and runoff reduction. There is need for incorporating green roofs into urban drainage models in order to evaluate their impact. These models must have low computational costs and fine time resolution. This paper aims to develop...... a model of green roof hydrological performance. A simple conceptual model for the long term and single event hydrological performance of green roofs, shows to be capable of reproducing observed runoff measurements. The model has surface and subsurface storage components representing the overall retention...... capacity of the green roof. The runoff from the system is described by the non-linear reservoir method and the storage capacity of the green roof is continuously re-established by evapotranspiration. Runoff data from a green roof in Denmark are collected and used for parameter calibration....

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

    Science.gov (United States)

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

    2016-04-01

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

  20. Rainfall-Runoff and Water-Balance Models for Management of the Fena Valley Reservoir, Guam

    Science.gov (United States)

    Yeung, Chiu W.

    2005-01-01

    The U.S. Geological Survey's Precipitation-Runoff Modeling System (PRMS) and a generalized water-balance model were calibrated and verified for use in estimating future availability of water in the Fena Valley Reservoir in response to various combinations of water withdrawal rates and rainfall conditions. Application of PRMS provides a physically based method for estimating runoff from the Fena Valley Watershed during the annual dry season, which extends from January through May. Runoff estimates from the PRMS are used as input to the water-balance model to estimate change in water levels and storage in the reservoir. A previously published model was calibrated for the Maulap and Imong River watersheds using rainfall data collected outside of the watershed. That model was applied to the Almagosa River watershed by transferring calibrated parameters and coefficients because information on daily diversions at the Almagosa Springs upstream of the gaging station was not available at the time. Runoff from the ungaged land area was not modeled. For this study, the availability of Almagosa Springs diversion data allowed the calibration of PRMS for the Almagosa River watershed. Rainfall data collected at the Almagosa rain gage since 1992 also provided better estimates of rainfall distribution in the watershed. In addition, the discontinuation of pan-evaporation data collection in 1998 required a change in the evapotranspiration estimation method used in the PRMS model. These reasons prompted the update of the PRMS for the Fena Valley Watershed. Simulated runoff volume from the PRMS compared reasonably with measured values for gaging stations on Maulap, Almagosa, and Imong Rivers, tributaries to the Fena Valley Reservoir. On the basis of monthly runoff simulation for the dry seasons included in the entire simulation period (1992-2001), the total volume of runoff can be predicted within -3.66 percent at Maulap River, within 5.37 percent at Almagosa River, and within 10

  1. Challenges to Rainfall-Runoff and Transit Time Distribution Modeling Within the Southeastern Coastal Plain, USA

    Science.gov (United States)

    Decker, P.; Cohen, M. J.; Jawitz, J. W.

    2017-12-01

    Previous hydrologic studies primarily focus on processes related to montane catchments with significant runoff ratios, low evapotranspiration rates, and reasonably short travel times. There is a significant lack of research for hydrologic processes occurring within the United States Southeastern Coastal Plain landscape where low-relief and high rates of evapotranspiration impact water fluxes. Hydrologic modeling efforts within this region may elucidate possible interactions and timescales of solute travel where much of the landscape is managed for agricultural crops, namely plantation forestry. A long-term paired watershed study carried out in northern Florida monitored two second-order blackwater streams for five years. Rainfall-runoff models for both catchments were created using daily discharge, precipitation, and modeled evapotranspiration as input parameters. Best fit occurred (NSE = 0.8) when the catchments were modeled as two-storage (shallow and deep) reservoirs in parallel and overland flow was allowed to contribute to streamflow in periods were shallow groundwater storage was at capacity. In addition, streamflow and rainfall chloride concentrations were used to model in-variable transit time distributions using spectral methods. In both catchments this transit time was unresolvable because output spectral power exceeded input spectral power, a result assumed to be driven by the evaporative demand of the region. A modeled chloride time series from random input concentration and modeled output through the rainfall-runoff model was used to alter the evaporation ratio. Once evaporation rates equaled known rates found in cool, high-relief catchments, spectral analysis illustrated higher input spectral power and therefore resolvable transit times. Findings from this study illustrate significant effects from evaporation within the catchment - often exceeding the signal from the background catchment process itself. Calculations illustrate a proposed mean transit

  2. Modelling Climate change influence on runoff and soil losses in a rainfed catchment with Mediterranean climate

    Science.gov (United States)

    Concepción Ramos, Maria; Martínez-Casasnovas, José A.

    2015-04-01

    The magnitude of erosion processes, widespread throughout the Mediterranean areas, may be enhanced due to changes in seasonal precipitation regimes and an increase of extreme events. The present research shows the results of possible effects of climate change on runoff and soil loss in a rainfed catchment located in the Barcelona province (NE Spain).In the study area, vines are the main land use, cultivated under the Penedès designation of origin. The present research shows the results of runoff and soil loss simulated using SWAT for a small basin with vines as main land use. Input data included detailed soil and land use maps, and daily climate data of the period 1998-2012. The analysis compared simulated results for years with different climatic conditions during that period and the average with predictions for the scenario 2020, 2050 and 2080 based on the HadCM3 GCM under A2 scenario and the trends observed in the area related to maximum rainfall intensity. The model was calibrated and validated using data recorded at different subbasins, using soil water and runoff samples. Taking into account the predicted changes in temperature and precipitation, the model simulated a decrease in soil loss associated with a decrease in runoff, mainly driven by an increase in evapotranspiration. However, the trend in soil losses varied when the changes in precipitation could balance the increase of evapotranspiration and also due to the increase of rainfall intensity. An increase in maximum rainfall intensity in spring and autumn (main rainy seasons) produced significant increases in soil loss: by up to 12% for the 2020 scenario and up to 57% for the 2050 scenario, although high differences may exists depending on rainfall characteristics. The research confirmed the difficulty of predicting future soil loss in this region, which has a very high climate inter-annual variability.

  3. Future Changes in Surface Runoff over Korea Projected by a Regional Climate Model under A1B Scenario

    Directory of Open Access Journals (Sweden)

    Ji-Woo Lee

    2014-01-01

    Full Text Available This study assesses future change of surface runoff due to climate change over Korea using a regional climate model (RCM, namely, the Global/Regional Integrated Model System (GRIMs, Regional Model Program (RMP. The RMP is forced by future climate scenario, namely, A1B of Intergovernmental Panel on Climate Change (IPCC Fourth Assessment Report (AR4. The RMP satisfactorily reproduces the observed seasonal mean and variation of surface runoff for the current climate simulation. The distribution of monsoonal precipitation-related runoff is adequately captured by the RMP. In the future (2040–2070 simulation, it is shown that the increasing trend of temperature has significant impacts on the intra-annual runoff variation. The variability of runoff is increased in summer; moreover, the strengthened possibility of extreme occurrence is detected in the future climate. This study indicates that future climate projection, including surface runoff and its variability over Korea, can be adequately addressed on the RMP testbed. Furthermore, this study reflects that global warming affects local hydrological cycle by changing major water budget components. This study adduces that the importance of runoff should not be overlooked in regional climate studies, and more elaborate presentation of fresh-water cycle is needed to close hydrological circulation in RCMs.

  4. A point-infiltration model for estimating runoff from rainfall on small basins in semiarid areas of Wyoming

    Science.gov (United States)

    Rankl, James G.

    1990-01-01

    A physically based point-infiltration model was developed for computing infiltration of rainfall into soils and the resulting runoff from small basins in Wyoming. The user describes a 'design storm' in terms of average rainfall intensity and storm duration. Information required to compute runoff for the design storm by using the model include (1) soil type and description, and (2) two infiltration parameters and a surface-retention storage parameter. Parameter values are tabulated in the report. Rainfall and runoff data for three ephemeral-stream basins that contain only one type of soil were used to develop the model. Two assumptions were necessary: antecedent soil moisture is some long-term average, and storm rainfall is uniform in both time and space. The infiltration and surface-retention storage parameters were determined for the soil of each basin. Observed rainstorm and runoff data were used to develop a separation curve, or incipient-runoff curve, which distinguishes between runoff and nonrunoff rainfall data. The position of this curve defines the infiltration and surface-retention storage parameters. A procedure for applying the model to basins that contain more than one type of soil was developed using data from 7 of the 10 study basins. For these multiple-soil basins, the incipient-runoff curve defines the infiltration and retention-storage parameters for the soil having the highest runoff potential. Parameters were defined by ranking the soils according to their relative permeabilities and optimizing the position of the incipient-runoff curve by using measured runoff as a control for the fit. Analyses of runoff from multiple-soil basins indicate that the effective contributing area of runoff is less than the drainage area of the basin. In this study, the effective drainage area ranged from 41.6 to 71.1 percent of the total drainage area. Information on effective drainage area is useful in evaluating drainage area as an independent variable in

  5. Application Of Global Sensitivity Analysis And Uncertainty Quantification In Dynamic Modelling Of Micropollutants In Stormwater Runoff

    DEFF Research Database (Denmark)

    Vezzaro, Luca; Mikkelsen, Peter Steen

    2012-01-01

    The need for estimating micropollutants fluxes in stormwater systems increases the role of stormwater quality models as support for urban water managers, although the application of such models is affected by high uncertainty. This study presents a procedure for identifying the major sources...... of uncertainty in a conceptual lumped dynamic stormwater runoff quality model that is used in a study catchment to estimate (i) copper loads, (ii) compliance with dissolved Cu concentration limits on stormwater discharge and (iii) the fraction of Cu loads potentially intercepted by a planned treatment facility...

  6. Evaluating the robustness of conceptual rainfall-runoff models under climate variability in northern Tunisia

    Science.gov (United States)

    Dakhlaoui, H.; Ruelland, D.; Tramblay, Y.; Bargaoui, Z.

    2017-07-01

    To evaluate the impact of climate change on water resources at the catchment scale, not only future projections of climate are necessary but also robust rainfall-runoff models that must be fairly reliable under changing climate conditions. The aim of this study was thus to assess the robustness of three conceptual rainfall-runoff models (GR4j, HBV and IHACRES) on five basins in northern Tunisia under long-term climate variability, in the light of available future climate scenarios for this region. The robustness of the models was evaluated using a differential split sample test based on a climate classification of the observation period that simultaneously accounted for precipitation and temperature conditions. The study catchments include the main hydrographical basins in northern Tunisia, which produce most of the surface water resources in the country. A 30-year period (1970-2000) was used to capture a wide range of hydro-climatic conditions. The calibration was based on the Kling-Gupta Efficiency (KGE) criterion, while model transferability was evaluated based on the Nash-Sutcliffe efficiency criterion and volume error. The three hydrological models were shown to behave similarly under climate variability. The models simulated the runoff pattern better when transferred to wetter and colder conditions than to drier and warmer ones. It was shown that their robustness became unacceptable when climate conditions involved a decrease of more than 25% in annual precipitation and an increase of more than +1.75 °C in annual mean temperatures. The reduction in model robustness may be partly due to the climate dependence of some parameters. When compared to precipitation and temperature projections in the region, the limits of transferability obtained in this study are generally respected for short and middle term. For long term projections under the most pessimistic emission gas scenarios, the limits of transferability are generally not respected, which may hamper the

  7. Spatial Interpolation of Annual Runoff in Ungauged Basins Based on the Improved Information Diffusion Model Using a Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Mei Hong

    2017-01-01

    Full Text Available Prediction in Ungauged Basins (PUB is an important task for water resources planning and management and remains a fundamental challenge for the hydrological community. In recent years, geostatistical methods have proven valuable for estimating hydrological variables in ungauged catchments. However, four major problems restrict the development of geostatistical methods. We established a new information diffusion model based on genetic algorithm (GIDM for spatial interpolating of runoff in the ungauged basins. Genetic algorithms (GA are used to generate high-quality solutions to optimization and search problems. So, using GA, the parameter of optimal window width can be obtained. To test our new method, seven experiments for the annual runoff interpolation based on GIDM at 17 stations on the mainstream and tributaries of the Yellow River are carried out and compared with the inverse distance weighting (IDW method, Cokriging (COK method, and conventional IDMs using the same sparse observed data. The seven experiments all show that the GIDM method can solve four problems of the previous geostatistical methods to some extent and obtains best accuracy among four different models. The key problems of the PUB research are the lack of observation data and the difficulties in information extraction. So the GIDM is a new and useful tool to solve the Prediction in Ungauged Basins (PUB problem and to improve the water management.

  8. a Empirical Modelation of Runoff in Small Watersheds Using LIDAR Data

    Science.gov (United States)

    Lopatin, J.; Hernández, J.; Galleguillos, M.; Mancilla, G.

    2013-12-01

    Hydrological models allow the simulation of water natural processes and also the quantification and prediction of the effects of human impacts in runoff behavior. However, obtaining the information that is need for applying these models can be costly in both time and resources, especially in large and difficult to access areas. The objective of this research was to integrate LiDAR data in the hydrological modeling of runoff in small watersheds, using derivated hydrologic, vegetation and topography variables. The study area includes 10 small head watersheds cover bay forest, between 2 and 16 ha, which are located in the south-central coastal range of Chile. In each of the former instantaneous rainfall and runoff flow of a total of 15 rainfall events were measured, between August 2012 and July 2013, yielding a total of 79 observations. In March 2011 a Harrier 54/G4 Dual System was used to obtain a LiDAR point cloud of discrete pulse with an average of 4.64 points per square meter. A Digital Terrain Model (DTM) of 1 meter resolution was obtained from the point cloud, and subsequently 55 topographic variables were derived, such as physical watershed parameters and morphometric features. At the same time, 30 vegetation descriptive variables were obtained directly from the point cloud and from a Digital Canopy Model (DCM). The classification and regression "Random Forest" (RF) algorithm was used to select the most important variables in predicting water height (liters), and the "Partial Least Squares Path Modeling" (PLS-PM) algorithm was used to fit a model using the selected set of variables. Four Latent variables were selected (outer model) related to: climate, topography, vegetation and runoff, where in each one was designated a group of the predictor variables selected by RF (inner model). The coefficient of determination (R2) and Goodnes-of-Fit (GoF) of the final model were obtained. The best results were found when modeling using only the upper 50th percentile of

  9. Modelling the impact of increasing soil sealing on runoff coefficients at regional scale: a hydropedological approach

    Directory of Open Access Journals (Sweden)

    Ungaro Fabrizio

    2014-03-01

    Full Text Available Soil sealing is the permanent covering of the land surface by buildings, infrastructures or any impermeable artificial material. Beside the loss of fertile soils with a direct impact on food security, soil sealing modifies the hydrological cycle. This can cause an increased flooding risk, due to urban development in potential risk areas and to the increased volumes of runoff. This work estimates the increase of runoff due to sealing following urbanization and land take in the plain of Emilia Romagna (Italy, using the Green and Ampt infiltration model for two rainfall return periods (20 and 200 years in two different years, 1976 and 2008. To this goal a hydropedological approach was adopted in order to characterize soil hydraulic properties via locally calibrated pedotransfer functions (PTF. PTF inputs were estimated via sequential Gaussian simulations coupled with a simple kriging with varying local means, taking into account soil type and dominant land use. Results show that in the study area an average increment of 8.4% in sealed areas due to urbanization and sprawl induces an average increment in surface runoff equal to 3.5 and 2.7% respectively for 20 and 200-years return periods, with a maximum > 20% for highly sealed coast areas.

  10. Global evaluation of runoff from ten state-of-the-art hydrological models

    Science.gov (United States)

    Beck, Hylke; de Roo, Ad; van Dijk, Albert; Schellekens, Jaap; Dutra, Emanuel; Fink, Gabriel; Orth, Rene

    2016-04-01

    Observed streamflow data from 966 medium sized catchments (1000 to 5000 km2) around the globe were used to comprehensively evaluate the daily runoff estimates (1979-2012) of six global hydrological models (GHMs) and four land surface models (LSMs) produced as part of Tier-1 of the eartH2Observe project. The models were all driven by the WATCH Forcing Data ERA-Interim (WFDEI) meteorological dataset, but used different datasets for non-meteorologic inputs and were run at various spatial and temporal resolutions, although all data were re-sampled to a common 0.5° spatial and daily temporal resolution. For the evaluation, we used a broad range of performance metrics related to important aspects of the hydrograph. We found pronounced inter-model performance differences, underscoring the importance of hydrological model uncertainty in addition to climate input uncertainty, for example in studies assessing the hydrological impacts of climate change. The (uncalibrated) GHMs were found to perform better than the LSMs in snow-dominated regions, and the ensemble mean was found to perform only slightly worse than the best (calibrated) model. The models generally showed an early bias in the spring snowmelt peak. We further found that, despite adjustments using gauge observations, the WFDEI precipitation data still contain substantial biases which propagate in the simulated runoff. Overall, more effort should be devoted to calibrating and regionalizing the parameters of macro-scale models.

  11. A simple model for farmland nitrogen loss to surface runoff with raindrop driven process

    Science.gov (United States)

    Tong, J.; Li, J.

    2016-12-01

    It has been widely recognized that surface runoff from the agricultural fields is an important source of non-point source pollution (NPSP). Moreover, as the agricultural country with the largest nitrogen fertilizer production, import and consumption in the world, our nation should pay greater attention to the over-application and inefficient use of nitrogen (N) fertilizer, which may cause severe pollution both in surface water and groundwater. To figure out the transfer mechanism between the soil solution and surface runoff, lots of laboratory test were conducted and related models were established in this study. But little of them was carried out in field scale since a part of variables are hard to control and some uncontrollable natural factors including rainfall intensity, temperature, wind speeds, soil spatial heterogeneity etc., may affect the field experimental results. Despite that, field tests can better reflect the mechanism of soil chemical loss to surface runoff than laboratory experiments, and the latter tend to oversimplify the environmental conditions. Therefore, a physically based, nitrogen transport model was developed and tested with so called semi-field experiments (i.e., artificial rainfall instead of natural rainfall was applied in the test). Our model integrated both raindrop driven process and diffusion effect along with the simplified nitrogen chain reactions. The established model was solved numerically through the modified Hydrus-1d source code, and the model simulations closely agree with the experimental data. Furthermore, our model indicates that the depth of the exchange layer and raindrop induced water transfer rate are two important parameters, and they have different impacts on the simulation results. The study results can provide references for preventing and controlling agricultural NPSP.

  12. Hourly runoff forecasting for flood risk management: Application of various computational intelligence models

    Science.gov (United States)

    Badrzadeh, Honey; Sarukkalige, Ranjan; Jayawardena, A. W.

    2015-10-01

    Reliable river flow forecasts play a key role in flood risk mitigation. Among different approaches of river flow forecasting, data driven approaches have become increasingly popular in recent years due to their minimum information requirements and ability to simulate nonlinear and non-stationary characteristics of hydrological processes. In this study, attempts are made to apply four different types of data driven approaches, namely traditional artificial neural networks (ANN), adaptive neuro-fuzzy inference systems (ANFIS), wavelet neural networks (WNN), and, hybrid ANFIS with multi resolution analysis using wavelets (WNF). Developed models applied for real time flood forecasting at Casino station on Richmond River, Australia which is highly prone to flooding. Hourly rainfall and runoff data were used to drive the models which have been used for forecasting with 1, 6, 12, 24, 36 and 48 h lead-time. The performance of models further improved by adding an upstream river flow data (Wiangaree station), as another effective input. All models perform satisfactorily up to 12 h lead-time. However, the hybrid wavelet-based models significantly outperforming the ANFIS and ANN models in the longer lead-time forecasting. The results confirm the robustness of the proposed structure of the hybrid models for real time runoff forecasting in the study area.

  13. Integrated Landsat Image Analysis and Hydrologic Modeling to Detect Impacts of 25-Year Land-Cover Change on Surface Runoff in a Philippine Watershed

    Directory of Open Access Journals (Sweden)

    Enrico Paringit

    2011-05-01

    Full Text Available Landsat MSS and ETM+ images were analyzed to detect 25-year land-cover change (1976–2001 in the critical Taguibo Watershed in Mindanao Island, Southern Philippines. This watershed has experienced historical modifications of its land-cover due to the presence of logging industries in the 1950s, and continuous deforestation due to illegal logging and slash-and-burn agriculture in the present time. To estimate the impacts of land-cover change on watershed runoff, land-cover information derived from the Landsat images was utilized to parameterize a GIS-based hydrologic model. The model was then calibrated with field-measured discharge data and used to simulate the responses of the watershed in its year 2001 and year 1976 land-cover conditions. The availability of land-cover information on the most recent state of the watershed from the Landsat ETM+ image made it possible to locate areas for rehabilitation such as barren and logged-over areas. We then created a “rehabilitated” land-cover condition map of the watershed (re-forestation of logged-over areas and agro-forestation of barren areas and used it to parameterize the model and predict the runoff responses of the watershed. Model results showed that changes in land-cover from 1976 to 2001 were directly related to the significant increase in surface runoff. Runoff predictions showed that a full rehabilitation of the watershed, especially in barren and logged-over areas, will be likely to reduce the generation of a huge volume of runoff during rainfall events. The results of this study have demonstrated the usefulness of multi-temporal Landsat images in detecting land-cover change, in identifying areas for rehabilitation, and in evaluating rehabilitation strategies for management of tropical watersheds through its use in hydrologic modeling.

  14. Application of XTOP_PRMS model in Green Lakes Valley, Colorado front range: Runoff simulation and flowpath identification

    Science.gov (United States)

    Liu, F.; Williams, M.; Webb, R.; Ackerman, T.

    2002-01-01

    Stream runoff was simulated from 1996 to 2000 using XTOP_PRMS (coupling of TOPMODEL and Precipitation Runoff Modeling System) model under Modular Modeling System at Martinelli and Green Lake 4 catchments in Green Lakes Valley, Colorado Front Range. Two flowpaths determined by XTOP_PRMS model, surface flow (infiltration-excess overland flow) and subsurface flow, were compared against the flowpaths determined by mixing model using isotopic and chemical tracers. Three tracers (DOC, K/Si, and ??18O) were used in mixing model to identify four flowpaths, i.e., overland, upper soil horizon, lower soil horizon, and base flow. The results showed that the runoff simulation using XTOP_PRMS model is reasonably successful for Martinelli catchment (8 ha in drainage area). The Nash-Sutcliffe efficiency is 0.76. The t-test of two means for paired sample showed that the difference between the observed and modeled runoff was not significantly different at ??=0.05 at Martinelli catchment (n = 1611, p = 0.6). The flowpaths identified by XTOP_PRMS model matched the flowpaths determined by the tracer-mixing model reasonably well in magnitude, but poorly in pattern. The surface flow primarily occurred in the beginning of snowmelt at Martinelli as illustrated by the tracer-mixing model. Both runoff simulation and flowpath identification using XTOP_PRMS model were relatively poor at Green Lake 4 catchment, which has a drainage area of 220 ha. The runoff peaks observed in May and June were not captured in runoff simulation. The problem may be caused by poor understanding of behaviors of flowpath parameters and insensitivity of snowmelt to daily mean air temperature.

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

    Science.gov (United States)

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

    2010-01-01

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

  16. CONFIGURATION GENERATOR MODEL

    Energy Technology Data Exchange (ETDEWEB)

    A. Alsaed

    2004-11-18

    ''The Disposal Criticality Analysis Methodology Topical Report'' prescribes an approach to the methodology for performing postclosure criticality analyses within the monitored geologic repository at Yucca Mountain, Nevada. An essential component of the methodology is the ''Configuration Generator Model for In-Package Criticality'' that provides a tool to evaluate the probabilities of degraded configurations achieving a critical state. The configuration generator model is a risk-informed, performance-based process for evaluating the criticality potential of degraded configurations in the monitored geologic repository. The method uses event tree methods to define configuration classes derived from criticality scenarios and to identify configuration class characteristics (parameters, ranges, etc.). The probabilities of achieving the various configuration classes are derived in part from probability density functions for degradation parameters. The NRC has issued ''Safety Evaluation Report for Disposal Criticality Analysis Methodology Topical Report, Revision 0''. That report contained 28 open items that required resolution through additional documentation. Of the 28 open items, numbers 5, 6, 9, 10, 18, and 19 were concerned with a previously proposed software approach to the configuration generator methodology and, in particular, the k{sub eff} regression analysis associated with the methodology. However, the use of a k{sub eff} regression analysis is not part of the current configuration generator methodology and, thus, the referenced open items are no longer considered applicable and will not be further addressed.

  17. A mathematical model for the transfer of soil solutes to runoff under water scouring.

    Science.gov (United States)

    Yang, Ting; Wang, Quanjiu; Wu, Laosheng; Zhang, Pengyu; Zhao, Guangxu; Liu, Yanli

    2016-11-01

    The transfer of nutrients from soil to runoff often causes unexpected pollution in water bodies. In this study, a mathematical model that relates to the detachment of soil particles by water flow and the degree of mixing between overland flow and soil nutrients was proposed. The model assumes that the mixing depth is an integral of average water flow depth, and it was evaluated by experiments with three water inflow rates to bare soil surfaces and to surfaces with eight treatments of different stone coverages. The model predicted outflow rates were compared with the experimentally observed data to test the accuracy of the infiltration parameters obtained by curve fitting the models to the data. Further analysis showed that the comprehensive mixing coefficient (ke) was linearly correlated with Reynolds' number Re (R(2)>0.9), and this relationship was verified by comparing the simulated potassium concentration and cumulative mass with observed data, respectively. The best performance with the bias error analysis (Nash Sutcliffe coefficient of efficiency (NS), relative error (RE) and the coefficient of determination (R(2))) showed that the predicted data by the proposed model was in good agreement with the measured data. Thus the model can be used to guide soil-water and fertilization management to minimize nutrient runoff from cropland. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. A characterization of Greenland Ice Sheet surface melt and runoff in contemporary reanalyses and a regional climate model

    Science.gov (United States)

    Cullather, Richard; Nowicki, Sophie; Zhao, Bin; Koenig, Lora

    2016-02-01

    For the Greenland Ice Sheet (GrIS), large-scale melt area has increased in recent years and is detectable via remote sensing, but its relation to runoff is not known. Historical, modeled melt area and runoff from Modern-Era Retrospective Analysis for Research and Applications (MERRA-Replay), the Interim Re-Analysis of the European Centre for Medium Range Weather Forecasts (ERA-I), the Climate Forecast System Reanalysis (CFSR), the Modèle Atmosphérique Régional (MAR), and the Arctic System Reanalysis (ASR) are examined. These sources compare favorably with satellite-derived estimates of surface melt area for the period 2000-2012. Spatially, the models markedly disagree on the number of melt days in the interior of the southern part of the ice sheet, and on the extent of persistent melt areas in the northeastern GrIS. Temporally, the models agree on the mean seasonality of daily surface melt and on the timing of large-scale melt events in 2012. In contrast, the models disagree on the amount, seasonality, spatial distribution, and temporal variability of runoff. As compared to global reanalyses, time series from MAR indicate a lower correlation between runoff and melt area (r2 = 0.805). Runoff in MAR is much larger in the second half of the melt season for all drainage basins, while the ASR indicates larger runoff in the first half of the year. This difference in seasonality for the MAR and to an extent for the ASR provide a hysteresis in the relation between runoff and melt area, which is not found in the other models. The comparison points to a need for reliable observations of surface runoff.

  19. Runoff generation processes and fraction of young water for streamflow and groundwater in a pre-alpine forested catchment

    Science.gov (United States)

    Zuecco, Giulia; Penna, Daniele; van Meerveld, Ilja; Borga, Marco

    2017-04-01

    Understanding of runoff generation mechanisms and storage dynamics is needed for sustainable management of water resources, particularly in catchments characterized by marked seasonality in rainfall. However, temporal and spatial variability of hydrological processes can hinder a detailed comprehension of catchment functioning. In this study, we use hydrometric data and stable isotope data from a 2-ha forested catchment in the Italian pre-Alps to i) identify seasonal changes in runoff generation, ii) determine the factors that affect the hysteretic relations between streamflow and soil moisture and between streamflow and shallow groundwater, and iii) estimate the fraction of young water in stream water and shallow groundwater. Streamflow, soil moisture and groundwater levels were measured continuously between August 2012 and December 2015. Soil moisture was measured at 0-30 cm depth by four time domain reflectometers installed at different locations along a riparian-hillslope transect. Depth to water table was measured in two piezometers installed at a depth of 2.0 and 1.8 m in the riparian zone. Water samples for isotopic analysis were taken monthly from bulk precipitation and approximately biweekly from stream water and groundwater. The relations between streamflow (independent variable), soil moisture and depth to water table (dependent variables) were analyzed by computing a hysteresis index that provides information on the direction, the extent and the shape of the loops for 103 rainfall-runoff events. The temporal variability of the hysteresis index was related to event characteristics (mean and maximum rainfall intensity, rainfall amount and total stormflow) and antecedent soil moisture conditions. We observed threshold-like relations between stormflow and the sum of rainfall and the antecedent soil moisture index and an exponential relation between the change in groundwater level and stormflow. Clockwise hysteretic relations were common between streamflow

  20. Future climate scenarios and rainfall-runoff modelling in the Upper Gallego catchment (Spain)

    International Nuclear Information System (INIS)

    Buerger, C.M.; Kolditz, O.; Fowler, H.J.; Blenkinsop, S.

    2007-01-01

    Global climate change may have large impacts on water supplies, drought or flood frequencies and magnitudes in local and regional hydrologic systems. Water authorities therefore rely on computer models for quantitative impact prediction. In this study we present kernel-based learning machine river flow models for the Upper Gallego catchment of the Ebro basin. Different learning machines were calibrated using daily gauge data. The models posed two major challenges: (1) estimation of the rainfall-runoff transfer function from the available time series is complicated by anthropogenic regulation and mountainous terrain and (2) the river flow model is weak when only climate data are used, but additional antecedent flow data seemed to lead to delayed peak flow estimation. These types of models, together with the presented downscaled climate scenarios, can be used for climate change impact assessment in the Gallego, which is important for the future management of the system. - Future climate change and data-based rainfall-runoff predictions are presented for the Upper Gallego

  1. Rainfall-runoff modelling of the Okavango River catchment to assess impacts of land use change on runoff and downstream ecosystems

    Science.gov (United States)

    Milzow, Christian; Bauer-Gottwein, Peter

    2010-05-01

    The competition between human water use and ecosystem water use is one of the major challenges for water resources management at the global scale. We analyse the situation for the Okavango River basin of southern Africa. The Okavango River is representative for many large rivers throughout the developing world in that it is ungauged and poorly studied. The Okavango basin - spanning over Angola, Namibia and Botswana - represents a multi-objective problem in an international setting. Economic benefits of agricultural development and conservation of ecosystem services call for opposed actions. A semi-distributed rainfall-runoff model of the Okavango catchment is set up using the Soil and Water Assessment Tool (SWAT). The model is sufficiently physically based to simulate the impact on runoff of extent of agricultural use, crop types and management practices. Precipitation and temperature inputs are taken from datasets covering large parts of the globe. The methodology can thus easily be applied for other ungauged catchments. For temperature we use the ERA-Interim reanalysis product of the European Centre for Medium-Range Weather Forecasts and for precipitation the Famine Early Warning Systems Network data (FEWS-Net). Tropical Rainfall Measurement Mission (TRMM) data resulted in poor model performance compared to the FEWS-Net data. Presently, the upstream catchment in Angola is largely pristine and agriculture is basically restricted to dry land subsistence farming. But economic growth in Angola is likely to result in agricultural development and consequent impacts on catchment runoff. Land use scenarios that are simulated include large scale irrigated agriculture with water extractions from the river and the shallow aquifer. Climate change impacts are also studied and compared to land use change impacts. The downstream part of the basin consists of the large Okavango Wetlands, which are a biodiversity hotspot of global importance and, through tourism, an important

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

    African Journals Online (AJOL)

    This study applied a rainfall-runoff model (HEC-HMS) and GIS techniques to estimate both the gauged and ungauged runoff contribution to the water balance of Cahora Bassa. The rivers considered in the study are the Zambezi, Kafue, Luangwa, Chongwe, Musengezi and Manyame. Missing data were generated using the ...

  3. The Idiosyncrasies of Storage and Implications for Catchment Runoff (Invited)

    Science.gov (United States)

    Spence, C.

    2010-12-01

    Because water goes into storage when it rains, perhaps the entire concept of a direct rainfall-runoff process is erroneous and misleading. Perhaps the runoff generation process is merely the conversion of storage to runoff. Using this perspective as a foundation, it then becomes important to understand how catchments retain water, where this storage is distributed and what controls the distribution of this storage. There is a growing body of observational evidence that the idiosyncrasies of storage in the catchment are crucial for runoff generation. These idiosyncrasies are important enough that some hydrologists are questioning assumptions of steady state, linearity, and topographic control in existing theories and algorithms of runoff generation. For instance, thresholds that control the release of water have been identified at many scales and in many landscapes. Hysteresis in storage-runoff relationships at all scales manifest because of these thresholds. Because storage thresholds at a range of scales are now known to be important for runoff response, connectivity has become an important concept crucial to interpreting catchment runoff response. There appears to be growing acceptance of such ideas as thresholds, hysteresis and connectivity in the hydrological literature. Theoretical development and model parameterization have begun, but there remains much work to resolve these field observations. In particular, our community should strive to investigate the relevance of storage-runoff relationships partly through innovative measurement techniques and the development of model structures appropriate for the requisite testing of these theories in a diversity of landscapes.

  4. Application of Hydrological Model PRMS to Simulate Daily Rainfall Runoff in Zamask-Yingluoxia Subbasin of the Heihe River Basin

    OpenAIRE

    Fei Teng; Wenrui Huang; Yi Cai; Chunmiao Zheng; Songbin Zou

    2017-01-01

    The Precipitation-Runoff Modeling System (PRMS) has been applied to simulate rainfall runoff in Zamask-Yingluoxia subbasin of the Heihe River Basin in this study. By using observed data in the subbasin, the model has been calibrated by comparing model simulations of daily stream flow to observed data at Yinglouxia station for the period of summer in 2004. Then model verification was conducted by keeping the same model parameters for the simulation of the period from 1 January 2003 to 31 Decem...

  5. Urban nonpoint source pollution buildup and washoff models for simulating storm runoff quality in the Los Angeles County

    International Nuclear Information System (INIS)

    Wang Long; Wei Jiahua; Huang Yuefei; Wang Guangqian; Maqsood, Imran

    2011-01-01

    Many urban nonpoint source pollution models utilize pollutant buildup and washoff functions to simulate storm runoff quality of urban catchments. In this paper, two urban pollutant washoff load models are derived using pollutant buildup and washoff functions. The first model assumes that there is no residual pollutant after a storm event while the second one assumes that there is always residual pollutant after each storm event. The developed models are calibrated and verified with observed data from an urban catchment in the Los Angeles County. The application results show that the developed model with consideration of residual pollutant is more capable of simulating nonpoint source pollution from urban storm runoff than that without consideration of residual pollutant. For the study area, residual pollutant should be considered in pollutant buildup and washoff functions for simulating urban nonpoint source pollution when the total runoff volume is less than 30 mm. - Highlights: → An improved urban NPS model was developed. → It performs well in areas where storm events have great temporal variation. → Threshold of total runoff volume for ignoring residual pollutant was determined. - An improved urban NPS model was developed. Threshold of total runoff volume for ignoring residual pollutant was determined.

  6. Evaluating the effects of model structure and meteorological input data on runoff modelling in an alpine headwater basin

    Science.gov (United States)

    Schattan, Paul; Bellinger, Johannes; Förster, Kristian; Schöber, Johannes; Huttenlau, Matthias; Kirnbauer, Robert; Achleitner, Stefan

    2017-04-01

    Modelling water resources in snow-dominated mountainous catchments is challenging due to both, short concentration times and a highly variable contribution of snow melt in space and time from complex terrain. A number of model setups exist ranging from physically based models to conceptional models which do not attempt to represent the natural processes in a physically meaningful way. Within the flood forecasting system for the Tyrolean Inn River two serially linked hydrological models with differing process representation are used. Non- glacierized catchments are modelled by a semi-distributed, water balance model (HQsim) based on the HRU-approach. A fully-distributed energy and mass balance model (SES), purpose-built for snow- and icemelt, is used for highly glacierized headwater catchments. Previous work revealed uncertainties and limitations within the models' structures regarding (i) the representation of snow processes in HQsim, (ii) the runoff routing of SES, and (iii) the spatial resolution of the meteorological input data in both models. To overcome these limitations, a "strengths driven" model coupling is applied. Instead of linking the models serially, a vertical one-way coupling of models has been implemented. The fully-distributed snow modelling of SES is combined with the semi-distributed HQsim structure, allowing to benefit from soil and runoff routing schemes in HQsim. A monte-carlo based modelling experiment was set up to evaluate the resulting differences in the runoff prediction due to the improved model coupling and a refined spatial resolution of the meteorological forcing. The experiment design follows a gradient of spatial discretisation of hydrological processes and meteorological forcing data with a total of six different model setups for the alpine headwater basin of the Fagge River in the Tyrolean Alps. In general, all setups show a good performance for this particular basin. It is therefore planned to include other basins with differing

  7. Coupling meteorological and hydrological models to evaluate the uncertainty in runoff forecasting: the case study of Maggiore Lake basin

    Science.gov (United States)

    Ceppi, A.; Ravazzani, G.; Rabuffetti, D.; Mancini, M.

    2009-04-01

    In recent years, the interest in the prediction and prevention of natural hazards related to hydro-meteorological events has increased the challenge for numerical weather modelling, in particular for limited area models, to improve the Quantitative Precipitation Forecasts (QPFs) for hydrological purposes. The development and implementation of a real-time flood forecasting system with a hydro-meteorological operational alert procedure during the MAP-D-PHASE Project is described in this paper. D-PHASE stands for Demonstration of Probabilistic Hydrological and Atmospheric Simulation of flood Events in the Alpine region and is a Forecast Demonstration Project (FDP) of the WWRP (World Weather Research Programme of WMO). It aims at demonstrating some of the many achievements of the Mesoscale Alpine Programme (MAP). The MAP FDP has addressed the entire forecasting chain, ranging from limited-area ensemble forecasting, high-resolution atmospheric modelling (km-scale), hydrological modelling and nowcasting to decision making by the end users, i.e., it is foreseen to set up an end-to-end forecasting system. The D-PHASE Operations Period (DOP) was from 1 June to 30 November 2007. In this study the hydro-meteorological chain includes both probabilistic forecasting based on ensemble prediction systems with lead time of a few days and short-range forecasts based on high resolution deterministic atmospheric models. D-PHASE hydrological ensemble forecasts are based on the 16 meteorological members, provided by COSMO-LEPS model (by ARPA Emilia-Romagna) with 5 day lead-time and a horizontal resolution of 10 km. Deterministic hydrological D-PHASE forecasts are provided by MOLOCH weather model (by ISAC-CNR) with a horizontal resolution of 2.2 km, nested into BOLAM, based on GFS initial and boundary conditions with 48 h lead-time. The hydrological model used to generate the runoff simulations is the rainfall-runoff distributed FEST-WB model, developed at Politecnico di Milano. The

  8. Global evaluation of runoff from 10 state-of-the-art hydrological models

    Science.gov (United States)

    Beck, Hylke E.; van Dijk, Albert I. J. M.; de Roo, Ad; Dutra, Emanuel; Fink, Gabriel; Orth, Rene; Schellekens, Jaap

    2017-06-01

    Observed streamflow data from 966 medium sized catchments (1000-5000 km2) around the globe were used to comprehensively evaluate the daily runoff estimates (1979-2012) of six global hydrological models (GHMs) and four land surface models (LSMs) produced as part of tier-1 of the eartH2Observe project. The models were all driven by the WATCH Forcing Data ERA-Interim (WFDEI) meteorological dataset, but used different datasets for non-meteorologic inputs and were run at various spatial and temporal resolutions, although all data were re-sampled to a common 0. 5° spatial and daily temporal resolution. For the evaluation, we used a broad range of performance metrics related to important aspects of the hydrograph. We found pronounced inter-model performance differences, underscoring the importance of hydrological model uncertainty in addition to climate input uncertainty, for example in studies assessing the hydrological impacts of climate change. The uncalibrated GHMs were found to perform, on average, better than the uncalibrated LSMs in snow-dominated regions, while the ensemble mean was found to perform only slightly worse than the best (calibrated) model. The inclusion of less-accurate models did not appreciably degrade the ensemble performance. Overall, we argue that more effort should be devoted on calibrating and regionalizing the parameters of macro-scale models. We further found that, despite adjustments using gauge observations, the WFDEI precipitation data still contain substantial biases that propagate into the simulated runoff. The early bias in the spring snowmelt peak exhibited by most models is probably primarily due to the widespread precipitation underestimation at high northern latitudes.

  9. Global evaluation of runoff from 10 state-of-the-art hydrological models

    Directory of Open Access Journals (Sweden)

    H. E. Beck

    2017-06-01

    Full Text Available Observed streamflow data from 966 medium sized catchments (1000–5000 km2 around the globe were used to comprehensively evaluate the daily runoff estimates (1979–2012 of six global hydrological models (GHMs and four land surface models (LSMs produced as part of tier-1 of the eartH2Observe project. The models were all driven by the WATCH Forcing Data ERA-Interim (WFDEI meteorological dataset, but used different datasets for non-meteorologic inputs and were run at various spatial and temporal resolutions, although all data were re-sampled to a common 0. 5° spatial and daily temporal resolution. For the evaluation, we used a broad range of performance metrics related to important aspects of the hydrograph. We found pronounced inter-model performance differences, underscoring the importance of hydrological model uncertainty in addition to climate input uncertainty, for example in studies assessing the hydrological impacts of climate change. The uncalibrated GHMs were found to perform, on average, better than the uncalibrated LSMs in snow-dominated regions, while the ensemble mean was found to perform only slightly worse than the best (calibrated model. The inclusion of less-accurate models did not appreciably degrade the ensemble performance. Overall, we argue that more effort should be devoted on calibrating and regionalizing the parameters of macro-scale models. We further found that, despite adjustments using gauge observations, the WFDEI precipitation data still contain substantial biases that propagate into the simulated runoff. The early bias in the spring snowmelt peak exhibited by most models is probably primarily due to the widespread precipitation underestimation at high northern latitudes.

  10. Regional drought assessment using a distributed hydrological model coupled with Standardized Runoff Index

    Directory of Open Access Journals (Sweden)

    H. Shen

    2015-05-01

    Full Text Available Drought assessment is essential for coping with frequent droughts nowadays. Owing to the large spatio-temporal variations in hydrometeorology in most regions in China, it is very necessary to use a physically-based hydrological model to produce rational spatial and temporal distributions of hydro-meteorological variables for drought assessment. In this study, the large-scale distributed hydrological model Variable Infiltration Capacity (VIC was coupled with a modified standardized runoff index (SRI for drought assessment in the Weihe River basin, northwest China. The result indicates that the coupled model is capable of reasonably reproducing the spatial distribution of drought occurrence. It reflected the spatial heterogeneity of regional drought and improved the physical mechanism of SRI. This model also has potential for drought forecasting, early warning and mitigation, given that accurate meteorological forcing data are available.

  11. A triangular model of dimensionless runoff producing rainfall hyetographs in Texas

    Science.gov (United States)

    Asquith, W.H.; Bumgarner, J.R.; Fahlquist, L.S.

    2003-01-01

    A synthetic triangular hyetograph for a large data base of Texas rainfall and runoff is needed. A hyetograph represents the temporal distribution of rainfall intensity at a point or over a watershed during a storm. Synthetic hyetographs are estimates of the expected time distribution for a design storm and principally are used in small watershed hydraulic structure design. A data base of more than 1,600 observed cumulative hyetographs that produced runoff from 91 small watersheds (generally less than about 50 km2) was used to provide statistical parameters for a simple triangular shaped hyetograph model. The model provides an estimate of the average hyetograph in dimensionless form for storm durations of 0 to 24 hours and 24 to 72 hours. As a result of this study, the authors concluded that the expected dimensionless cumulative hyetographs of 0 to 12 hour and 12 to 24 hour durations were sufficiently similar to be combined with minimal information loss. The analysis also suggests that dimensionless cumulative hyetographs are independent of the frequency level or return period of total storm depth and thus are readily used for many design applications. The two triangular hyetographs presented are intended to enhance small watershed design practice in applicable parts of Texas.

  12. A comparative analysis of projected impacts of climate change on river runoff from global and catchment-scale hydrological models

    Science.gov (United States)

    Gosling, S. N.; Taylor, R. G.; Arnell, N. W.; Todd, M. C.

    2011-01-01

    We present a comparative analysis of projected impacts of climate change on river runoff from two types of distributed hydrological model, a global hydrological model (GHM) and catchment-scale hydrological models (CHM). Analyses are conducted for six catchments that are global in coverage and feature strong contrasts in spatial scale as well as climatic and developmental conditions. These include the Liard (Canada), Mekong (SE Asia), Okavango (SW Africa), Rio Grande (Brazil), Xiangxi (China) and Harper's Brook (UK). A single GHM (Mac-PDM.09) is applied to all catchments whilst different CHMs are applied for each catchment. The CHMs include SLURP v. 12.2 (Liard), SLURP v. 12.7 (Mekong), Pitman (Okavango), MGB-IPH (Rio Grande), AV-SWAT-X 2005 (Xiangxi) and Cat-PDM (Harper's Brook). The CHMs typically simulate water resource impacts based on a more explicit representation of catchment water resources than that available from the GHM and the CHMs include river routing, whereas the GHM does not. Simulations of mean annual runoff, mean monthly runoff and high (Q5) and low (Q95) monthly runoff under baseline (1961-1990) and climate change scenarios are presented. We compare the simulated runoff response of each hydrological model to (1) prescribed increases in global-mean air temperature of 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 °C relative to baseline from the UKMO HadCM3 Global Climate Model (GCM) to explore response to different amounts of climate forcing, and (2) a prescribed increase in global-mean air temperature of 2.0 °C relative to baseline for seven GCMs to explore response to climate model structural uncertainty. We find that the differences in projected changes of mean annual runoff between the two types of hydrological model can be substantial for a given GCM (e.g. an absolute GHM-CHM difference in mean annual runoff percentage change for UKMO HadCM3 2 °C warming of up to 25%), and they are generally larger for indicators of high and low monthly runoff. However

  13. A comparative analysis of projected impacts of climate change on river runoff from global and catchment-scale hydrological models

    Directory of Open Access Journals (Sweden)

    S. N. Gosling

    2011-01-01

    Full Text Available We present a comparative analysis of projected impacts of climate change on river runoff from two types of distributed hydrological model, a global hydrological model (GHM and catchment-scale hydrological models (CHM. Analyses are conducted for six catchments that are global in coverage and feature strong contrasts in spatial scale as well as climatic and developmental conditions. These include the Liard (Canada, Mekong (SE Asia, Okavango (SW Africa, Rio Grande (Brazil, Xiangxi (China and Harper's Brook (UK. A single GHM (Mac-PDM.09 is applied to all catchments whilst different CHMs are applied for each catchment. The CHMs include SLURP v. 12.2 (Liard, SLURP v. 12.7 (Mekong, Pitman (Okavango, MGB-IPH (Rio Grande, AV-SWAT-X 2005 (Xiangxi and Cat-PDM (Harper's Brook. The CHMs typically simulate water resource impacts based on a more explicit representation of catchment water resources than that available from the GHM and the CHMs include river routing, whereas the GHM does not. Simulations of mean annual runoff, mean monthly runoff and high (Q5 and low (Q95 monthly runoff under baseline (1961–1990 and climate change scenarios are presented. We compare the simulated runoff response of each hydrological model to (1 prescribed increases in global-mean air temperature of 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 °C relative to baseline from the UKMO HadCM3 Global Climate Model (GCM to explore response to different amounts of climate forcing, and (2 a prescribed increase in global-mean air temperature of 2.0 °C relative to baseline for seven GCMs to explore response to climate model structural uncertainty.

    We find that the differences in projected changes of mean annual runoff between the two types of hydrological model can be substantial for a given GCM (e.g. an absolute GHM-CHM difference in mean annual runoff percentage change for UKMO HadCM3 2 °C warming of up to 25%, and they are generally larger for indicators of high and low monthly runoff

  14. Modelling field scale spatial variation in water run-off, soil moisture, N2O emissions and herbage biomass of a grazed pasture using the SPACSYS model.

    Science.gov (United States)

    Liu, Yi; Li, Yuefen; Harris, Paul; Cardenas, Laura M; Dunn, Robert M; Sint, Hadewij; Murray, Phil J; Lee, Michael R F; Wu, Lianhai

    2018-04-01

    In this study, we evaluated the ability of the SPACSYS model to simulate water run-off, soil moisture, N 2 O fluxes and grass growth using data generated from a field of the North Wyke Farm Platform. The field-scale model is adapted via a linked and grid-based approach (grid-to-grid) to account for not only temporal dynamics but also the within-field spatial variation in these key ecosystem indicators. Spatial variability in nutrient and water presence at the field-scale is a key source of uncertainty when quantifying nutrient cycling and water movement in an agricultural system. Results demonstrated that the new spatially distributed version of SPACSYS provided a worthy improvement in accuracy over the standard (single-point) version for biomass productivity. No difference in model prediction performance was observed for water run-off, reflecting the closed-system nature of this variable. Similarly, no difference in model prediction performance was found for N 2 O fluxes, but here the N 2 O predictions were noticeably poor in both cases. Further developmental work, informed by this study's findings, is proposed to improve model predictions for N 2 O. Soil moisture results with the spatially distributed version appeared promising but this promise could not be objectively verified.

  15. How would peak rainfall intensity affect runoff predictions using conceptual water balance models?

    Directory of Open Access Journals (Sweden)

    B. Yu

    2015-06-01

    Full Text Available Most hydrological models use continuous daily precipitation and potential evapotranspiration for streamflow estimation. With the projected increase in mean surface temperature, hydrological processes are set to intensify irrespective of the underlying changes to the mean precipitation. The effect of an increase in rainfall intensity on the long-term water balance is, however, not adequately accounted for in the commonly used hydrological models. This study follows from a previous comparative analysis of a non-stationary daily series of stream flow of a forested watershed (River Rimbaud in the French Alps (area = 1.478 km2 (1966–2006. Non-stationarity in the recorded stream flow occurred as a result of a severe wild fire in 1990. Two daily models (AWBM and SimHyd were initially calibrated for each of three distinct phases in relation to the well documented land disturbance. At the daily and monthly time scales, both models performed satisfactorily with the Nash–Sutcliffe coefficient of efficiency (NSE varying from 0.77 to 0.92. When aggregated to the annual time scale, both models underestimated the flow by about 22% with a reduced NSE at about 0.71. Exploratory data analysis was undertaken to relate daily peak hourly rainfall intensity to the discrepancy between the observed and modelled daily runoff amount. Preliminary results show that the effect of peak hourly rainfall intensity on runoff prediction is insignificant, and model performance is unlikely to improve when peak daily precipitation is included. Trend analysis indicated that the large decrease of precipitation when daily precipitation amount exceeded 10–20 mm may have contributed greatly to the decrease in stream flow of this forested watershed.

  16. Assessing climate change impacts on runoff from karstic watersheds: NASA/GISS land-surface model improvement

    Science.gov (United States)

    Blake, Reginald Alexander

    The off-line version of the Goddard Institute for Space Studies (GISS) land-surface hydrological model over- predicted run-off from the karstic Rio Cobre watershed in Jamaica. To assess possible climate change impacts on runoff from the watershed, the model's simulation of observed runoff was improved by adding to it a karst component that has pipe flow features. The improved model was tested on two other karstic watersheds (Yangtze - China and Rio Grande - USA) and the results were encouraging. The impacts that possible climate change may have on the three karstic watersheds were then assessed. The assessment indicates that in a doubled carbon dioxide climate, the Rio Cobre and the Rio Grande may experience decreases in runoff, especially in low flow periods. The Yangtze, on the other hand, may not experience decreases in total runoff, but its peak flow which now occurs in July may be attenuated and shifted to September. The results of the study also show that climate feedbacks convolute climate change assessments and that different results can be obtained from the same climate change scenario depending on the choice of the modeling methodology-that is, on whether the models are coupled or uncoupled.

  17. Modeling Rainfall-Runoff Response to Land Use and Land Cover Change in Rwanda (1990–2016

    Directory of Open Access Journals (Sweden)

    Fidele Karamage

    2017-02-01

    Full Text Available Stormwater runoff poses serious environmental problems and public health issues in Rwanda, a tropical country that is increasingly suffering from severe floods, landslides, soil erosion and water pollution. Using the WetSpa Extension model, this study assessed the changes in rainfall runoff depth in Rwanda from 1990 to 2016 in response to precipitation and land use changes. Our results show that Rwanda has experienced a significant conversion of natural forest and grassland to cropland and built-up areas. During the period 1990–2016, 7090.02 km2 (64.5% and 1715.26 km2 (32.1% of forest and grassland covers were lost, respectively, while the cropland and built-up areas increased by 135.3% (8503.75 km2 and 304.3% (355.02 km2, respectively. According to our estimates, the land use change effect resulted in a national mean runoff depth increase of 2.33 mm/year (0.38%. Although precipitation change affected the inter-annual fluctuation of runoff, the long-term trend of runoff was dominated by land use change. The top five districts that experienced the annual runoff depth increase (all >3.8 mm/year are Rubavu, Nyabihu, Ngororero, Gakenke, and Musanze. Their annual runoff depths increased at a rate of >3.8 mm/year during the past 27 years, due to severe deforestation (ranging from 62% to 85% and cropland expansion (ranging from 123% to 293%. These areas require high priority in runoff control using terracing in croplands and rainwater harvesting systems such as dam/reservoirs, percolation tanks, storage tanks, etc. The wet season runoff was three times higher than the dry season runoff in Rwanda; appropriate rainwater management and reservation could provide valuable irrigation water for the dry season or drought years (late rainfall onsets or early rainfall cessations. It was estimated that a reservation of 30.5% (3.99 km3 of the runoff in the wet season could meet the cropland irrigation water gap during the dry season in 2016.

  18. Insight into runoff characteristics using hydrological modeling in the data-scarce southern Tibetan Plateau: Past, present, and future.

    Science.gov (United States)

    Cai, Mingyong; Yang, Shengtian; Zhao, Changsen; Zhou, Qiuwen; Hou, Lipeng

    2017-01-01

    Regional hydrological modeling in ungauged regions has attracted growing attention in water resources research. The southern Tibetan Plateau often suffers from data scarcity in watershed hydrological simulation and water resources assessment. This hinders further research characterizing the water cycle and solving international water resource issues in the area. In this study, a multi-spatial data based Distributed Time-Variant Gain Model (MS-DTVGM) is applied to the Yarlung Zangbo River basin, an important international river basin in the southern Tibetan Plateau with limited meteorological data. This model is driven purely by spatial data from multiple sources and is independent of traditional meteorological data. Based on the methods presented in this study, daily snow cover and potential evapotranspiration data in the Yarlung Zangbo River basin in 2050 are obtained. Future (2050) climatic data (precipitation and air temperature) from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC-AR5) are used to study the hydrological response to climate change. The result shows that river runoff will increase due to precipitation and air temperature changes by 2050. Few differences are found between daily runoff simulations from different Representative Concentration Pathway (RCP) scenarios (RCP2.6, RCP4.5 and RCP8.5) for 2050. Historical station observations (1960-2000) at Nuxia and model simulations for two periods (2006-2009 and 2050) are combined to study inter-annual and intra-annual runoff distribution and variability. The inter-annual runoff variation is stable and the coefficient of variation (CV) varies from 0.21 to 0.27. In contrast, the intra-annual runoff varies significantly with runoff in summer and autumn accounting for more than 80% of the total amount. Compared to the historical period (1960-2000), the present period (2006-2009) has a slightly uneven intra-annual runoff temporal distribution, and becomes more balanced in

  19. Insight into runoff characteristics using hydrological modeling in the data-scarce southern Tibetan Plateau: Past, present, and future.

    Directory of Open Access Journals (Sweden)

    Mingyong Cai

    Full Text Available Regional hydrological modeling in ungauged regions has attracted growing attention in water resources research. The southern Tibetan Plateau often suffers from data scarcity in watershed hydrological simulation and water resources assessment. This hinders further research characterizing the water cycle and solving international water resource issues in the area. In this study, a multi-spatial data based Distributed Time-Variant Gain Model (MS-DTVGM is applied to the Yarlung Zangbo River basin, an important international river basin in the southern Tibetan Plateau with limited meteorological data. This model is driven purely by spatial data from multiple sources and is independent of traditional meteorological data. Based on the methods presented in this study, daily snow cover and potential evapotranspiration data in the Yarlung Zangbo River basin in 2050 are obtained. Future (2050 climatic data (precipitation and air temperature from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC-AR5 are used to study the hydrological response to climate change. The result shows that river runoff will increase due to precipitation and air temperature changes by 2050. Few differences are found between daily runoff simulations from different Representative Concentration Pathway (RCP scenarios (RCP2.6, RCP4.5 and RCP8.5 for 2050. Historical station observations (1960-2000 at Nuxia and model simulations for two periods (2006-2009 and 2050 are combined to study inter-annual and intra-annual runoff distribution and variability. The inter-annual runoff variation is stable and the coefficient of variation (CV varies from 0.21 to 0.27. In contrast, the intra-annual runoff varies significantly with runoff in summer and autumn accounting for more than 80% of the total amount. Compared to the historical period (1960-2000, the present period (2006-2009 has a slightly uneven intra-annual runoff temporal distribution, and becomes more

  20. Simulation of Streamflow in a Discontinuous Permafrost Environment Using a Modified First-order, Nonlinear Rainfall-runoff Model

    Science.gov (United States)

    Bolton, W. R.; Hinzman, L. D.

    2009-12-01

    The sub-arctic environment can be characterized by being located in the zone of discontinuous permafrost. Although the distribution of permafrost in this region is specific, it dominates the response of many of the hydrologic processes including stream flow, soil moisture dynamics, and water storage processes. In areas underlain by permafrost, ice-rich conditions at the permafrost table inhibit surface water percolation to the deep subsurface soils, resulting in an increased runoff generation generation during precipitation events, decreased baseflow between precipitation events, and relatively wetter soils compared to permafrost-free areas. Over the course of a summer season, the thawing of the active layer (the thin soil layer about the permafrost that seasonally freezes and thaws) increases the potential water holding capacity of the soil, resulting in a decreasing surface water contribution during precipitation events and a steadily increasing baseflow contribution between precipitation events. Simulation of stream flow in this region is challenging due to the rapidly changing thermal (permafrost versus non-permafrost, active layer development) and hydraulic (hydraulic conductivity and soil storage capacity) conditions in both time and space (x, y, and z-dimensions). Many of the factors that have a control on both permafrost distribution and the thawing/freezing of active layer (such as soil material, soil moisture, and ice content) are not easily quantified at scales beyond the point measurement. In this study, these issues are addressed through streamflow analysis - the only hydrologic process that is easily measured at the basin scale. Following the general procedure outlined in Kirchner (2008), a simple rainfall-runoff model was applied to three small head-water basins of varying permafrost coverage. A simple, first-order, non-linear differential equation that describes the storage-discharge relationship were derived from three years of stream flow data

  1. Development of urban runoff model FFC-QUAL for first-flush water-quality analysis in urban drainage basins.

    Science.gov (United States)

    Hur, Sungchul; Nam, Kisung; Kim, Jungsoo; Kwak, Changjae

    2018-01-01

    An urban runoff model that is able to compute the runoff, the pollutant loadings, and the concentrations of water-quality constituents in urban drainages during the first flush was developed. This model, which is referred to as FFC-QUAL, was modified from the existing ILLUDAS model and added for use during the water-quality analysis process for dry and rainy periods. For the dry period, the specifications of the coefficients for the discharge and water quality were used. During rainfall, we used the Clark and time-area methods for the runoff analyses of pervious and impervious areas to consider the effects of the subbasin shape; moreover, four pollutant accumulation methods and the washoff equation for computing the water quality each time were used. According to the verification results, FFC-QUAL provides generally similar output as the measured data for the peak flow, total runoff volume, total loadings, peak concentration, and time of peak concentration for three rainfall events in the Gunja subbasin. In comparison with the ILLUDAS, SWMM, and MOUSE models, there is little difference between these models and the model developed in this study. The proposed model should be useful in urban watersheds because of its simplicity and its capacity to model common pollutants (e.g., biological oxygen demand, chemical oxygen demand, Escherichia coli, suspended solids, and total nitrogen and phosphorous) in runoff. The proposed model can also be used in design studies to determine how changes in infrastructure will affect the runoff and pollution loads. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  3. Bayesian uncertainty assessment of flood predictions in ungauged urban basins for conceptual rainfall-runoff models

    Directory of Open Access Journals (Sweden)

    A. E. Sikorska

    2012-04-01

    Full Text Available Urbanization and the resulting land-use change strongly affect the water cycle and runoff-processes in watersheds. Unfortunately, small urban watersheds, which are most affected by urban sprawl, are mostly ungauged. This makes it intrinsically difficult to assess the consequences of urbanization. Most of all, it is unclear how to reliably assess the predictive uncertainty given the structural deficits of the applied models. In this study, we therefore investigate the uncertainty of flood predictions in ungauged urban basins from structurally uncertain rainfall-runoff models. To this end, we suggest a procedure to explicitly account for input uncertainty and model structure deficits using Bayesian statistics with a continuous-time autoregressive error model. In addition, we propose a concise procedure to derive prior parameter distributions from base data and successfully apply the methodology to an urban catchment in Warsaw, Poland. Based on our results, we are able to demonstrate that the autoregressive error model greatly helps to meet the statistical assumptions and to compute reliable prediction intervals. In our study, we found that predicted peak flows were up to 7 times higher than observations. This was reduced to 5 times with Bayesian updating, using only few discharge measurements. In addition, our analysis suggests that imprecise rainfall information and model structure deficits contribute mostly to the total prediction uncertainty. In the future, flood predictions in ungauged basins will become more important due to ongoing urbanization as well as anthropogenic and climatic changes. Thus, providing reliable measures of uncertainty is crucial to support decision making.

  4. Identification of hotspots for potential pyrethroid runoff: a GIS modeling study in San Joaquin River Watershed of California, USA

    Science.gov (United States)

    Zhang, Xuyang; Zhang, Minghua; Liu, Xingmei

    2008-09-01

    This paper attempts to identify the high-risk areas for potential runoff of pyrethroid pesticides in the San Joaquin River Watershed. Pyrethroid pesticides have been detected in water and fluvial sediments in this watershed, creating concerns about potential negative impacts on water quality. However, little documentation exists regarding the distributions or the extent of the adverse effects caused by the use of pyrethroids. This study developed a geographic information systems (GIS) model to identify areas with high potential for pyrethroid runoff during the rainy season. The model was then validated using field-monitoring data. Nine factors were identified for the runoff risk assessment: amount of active ingredient used, soil erodibility factor, hydrologic group, surface layer depth, seasonal rainfall, seasonal number of rainy days, seasonal number of storm events, stream density, and land cover. The results indicated that high pyrethroid runoff risks were associated with basins such as the Stanislaus River Sub-basin, Newman Gustine Sub-basin and South Merced Sub-basin. This study demonstrated that the GIS model is capable of predicting high-risk areas of pyrethroid runoff at sub-basin scale. The model can be used to prioritize sites for water quality monitoring and guide implementations of best management practices.

  5. Multi-model approach to assess the impact of climate change on runoff

    Science.gov (United States)

    Dams, J.; Nossent, J.; Senbeta, T. B.; Willems, P.; Batelaan, O.

    2015-10-01

    The assessment of climate change impacts on hydrology is subject to uncertainties related to the climate change scenarios, stochastic uncertainties of the hydrological model and structural uncertainties of the hydrological model. This paper focuses on the contribution of structural uncertainty of hydrological models to the overall uncertainty of the climate change impact assessment. To quantify the structural uncertainty of hydrological models, four physically based hydrological models (SWAT, PRMS and a semi- and fully distributed version of the WetSpa model) are set up for a catchment in Belgium. Each model is calibrated using four different objective functions. Three climate change scenarios with a high, mean and low hydrological impact are statistically perturbed from a large ensemble of climate change scenarios and are used to force the hydrological models. This methodology allows assessing and comparing the uncertainty introduced by the climate change scenarios with the uncertainty introduced by the hydrological model structure. Results show that the hydrological model structure introduces a large uncertainty on both the average monthly discharge and the extreme peak and low flow predictions under the climate change scenarios. For the low impact climate change scenario, the uncertainty range of the mean monthly runoff is comparable to the range of these runoff values in the reference period. However, for the mean and high impact scenarios, this range is significantly larger. The uncertainty introduced by the climate change scenarios is larger than the uncertainty due to the hydrological model structure for the low and mean hydrological impact scenarios, but the reverse is true for the high impact climate change scenario. The mean and high impact scenarios project increasing peak discharges, while the low impact scenario projects increasing peak discharges only for peak events with return periods larger than 1.6 years. All models suggest for all scenarios a

  6. A Physically Based Runoff Model Analysis of the Querétaro River Basin

    Directory of Open Access Journals (Sweden)

    Carlos Javier Villa Alvarado

    2014-01-01

    Full Text Available Today the knowledge of physical parameters of a basin is essential to know adequately the rainfall-runoff process; it is well known that the specific characteristics of each basin such as temperature, geographical location, and elevation above sea level affect the maximum discharge and the basin time response. In this paper a physically based model has been applied, to analyze water balance by evaluating the volume rainfall-runoff using SHETRAN and hydrometric data measurements in 2003. The results have been compared with five ETp different methodologies in the Querétaro river basin in central Mexico. With these results the main effort of the authorities should be directed to better control of land-use changes and to working permanently in the analysis of the related parameters, which will have a similar behavior to changes currently being introduced and presented in observed values in this basin. This methodology can be a strong base for sustainable water management in a basin, the prognosis and effect of land-use changes, and availability of water and also can be used to determine application of known basin parameters, basically depending on land-use, land-use changes, and climatological database to determine the water balance in a basin.

  7. Application of a simple first-order, non-linear rainfall-runoff model in watersheds of varying permafrost coverage

    Science.gov (United States)

    Bolton, W. Robert; Hinzman, Larry

    2010-05-01

    The arctic and sub-arctic environments can be characterized as being in the zones continuous and discontinuous permafrost. Although the distribution of permafrost in these regions is site specific, it is the major control on many of the hydrologic processes including stream flow, soil moisture dynamics, and water storage processes. In areas underlain by permafrost, ice-rich soils a the permafrost table inhibit surface water percolation to the deep subsurface soils, resulting in an increased runoff generation during precipitation events (including snow melt), decreased baseflow between precipitation events, and relatively wetter soils compared to permafrost-free areas. Over the course of a summer season, the thawing of the active layer (the thin soil layer above the permafrost that seasonally freezes and thaws) increases the potential water holding capacity of the soil, resulting in a decreasing surface water contribution during precipitation events and a steadily increasing baseflow between precipitation events. The major challenge to hydrologic modeling in permafrost affected environments is accounting for the rapid spatial and temporal changes in the soil storage component with the thawing and freezing of the active layer and distribution of permafrost. Simulation of the storage storage component is further complicated as many of the variables that control the development of the active layer (and permafrost distribution) are not easily measurable beyond the point scale. Examples of these variables include soil material, soil moisture content, soil ice content, snow cover and depth, and surface temperature. Kirchner (2009) describes a method in which the total storage of a watershed can be derived directly from discharge measurements - the only hydrologic process that is easily measured at the watershed scale. Following the general procedure outlined by Kirchner, a simple rainfall-runoff model was developed and applied to basins of various scales and permafrost

  8. Integration of Spatially Hydrological Modelling on Bentong Catchment, Pahang, Peninsular Malaysia Using Distributed GIS-based Rainfall Runoff Model

    Directory of Open Access Journals (Sweden)

    Rosli, M.H.

    2017-07-01

    Full Text Available With the advance of GIS technology, hydrology model can simulated at catchment wide scale. The objective is to integrate National Resource Conservation Service (NRCS Curve Number (CN with kinematic wave and manning’s equation using GIS to develop a simple GIS-based distributed model to simulate rainfall runoff in Bentong catchment. Model was built using Spatial Distributed Direct Hydrograph (SDDH concept and applying the time area (TA approach in presenting the predicted discharge hydrograph. The effective precipitation estimation was first calculated using the NRCS CN method. Then, the core maps that consists of digital elevation model (DEM, soil and land use map in grid. DEM was used to derive slope, flow direction and flow accumulation while soil and land use map used to derive roughness coefficient and CN. The overland velocity and channel velocity estimation derived from combination of kinematic wave theory with Manning’s equation. To capture the time frame, the travel time map was divided into isochrones in order to generate the TA histogram and finally. The creation of SDDH using the TA histogram which will lead to the estimation of travel time for the catchment. Simulated hydrograph was plotted together with the observed discharge for comparison. Six storm events used for model performance evaluation using statistical measure such as Nash-Sutcliffe efficiency (NSE, percent bias (PBIAS and coefficient of determination (R2;. SDDH model performed quite well as NSE gave result ranging from 0.55 to 0.68 with mean of 0.6. PBIAS indicate that the model slightly over predicted compared to observed hydrograph with result ranges from -46.71 (the most over predicted to +4.83 (the most under predicted with average of -20.73%. R2; ranges between 0.55 to 0.82 with mean of 0.67. When comparing the time to peak, (tp, min, and peak discharge, (pd, m3/s, results gave NSEtp 0.82, PBIAStp 0.65, R2tp 0.32, NSEpd 0.95, PBIASpd 14.49 and R2pd 0

  9. Non-linear, connectivity and threshold-dominated runoff-generation controls DOC and heavy metal export in a small peat catchment

    Science.gov (United States)

    Birkel, Christian; Broder, Tanja; Biester, Harald

    2017-04-01

    Peat soils act as important carbon sinks, but they also release large amounts of dissolved organic carbon (DOC) to the aquatic system. The DOC export is strongly tied to the export of soluble heavy metals. The accumulation of potentially toxic substances due to anthropogenic activities, and their natural export from peat soils to the aquatic system is an important health and environmental issue. However, limited knowledge exists as to how much of these substances are mobilized, how they are mobilized in terms of flow pathways and under which hydrometeorological conditions. In this study, we report from a combined experimental and modelling effort to provide greater process understanding from a small, lead (Pb) and arsenic (As) contaminated upland peat catchment in northwestern Germany. We developed a minimally parameterized, but process-based, coupled hydrology-biogeochemistry model applied to simulate detailed hydrometric and biogeochemical data. The model was based on an initial data mining analysis, in combination with regression relationships of discharge, DOC and element export. We assessed the internal model DOC-processing based on stream-DOC hysteresis patterns and 3-hourly time step groundwater level and soil DOC data (not used for calibration as an independent model test) for two consecutive summer periods in 2013 and 2014. We found that Pb and As mobilization can be efficiently predicted from DOC transport alone, but Pb showed a significant non-linear relationship with DOC, while As was linearly related to DOC. The relatively parsimonious model (nine calibrated parameters in total) showed the importance of non-linear and rapid near-surface runoff-generation mechanisms that caused around 60% of simulated DOC load. The total load was high even though these pathways were only activated during storm events on average 30% of the monitoring time - as also shown by the experimental data. Overall, the drier period 2013 resulted in increased nonlinearity, but

  10. Assessment of CREAMS [Chemicals, Runoff, and Erosion from Agricultural Management Systems] and ERHYM-II [Ekalaka Rangeland Hydrology and Yield Model] computer models for simulating soil water movement on the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Laundre, J.W.

    1990-05-01

    The major goal of radioactive waste management is long-term containment of radioactive waste. Long-term containment is dependent on understanding water movement on, into, and through trench caps. Several computer simulation models are available for predicting water movement. Of the several computer models available, CREAMS (Chemicals, Runoff, and Erosion from Agricultural Management Systems) and ERHYM-II (Ekalaka Rangeland Hydrology and Yield Model) were tested for use on the Idaho National Engineering Laboratory (INEL). The models were calibrated, tested for sensitivity, and used to evaluate some basic trench cap designs. Each model was used to postdict soil moisture, evapotranspiration, and runoff of two watersheds for which such data were already available. Sensitivity of the models was tested by adjusting various input parameters from high to low values and then comparing model outputs to those generated from average values. Ten input parameters of the CREAMS model were tested for sensitivity. 17 refs., 23 figs., 20 tabs

  11. Influence of rainfall spatial variability on rainfall-runoff modelling: Benefit of a simulation approach?

    Science.gov (United States)

    Emmanuel, I.; Andrieu, H.; Leblois, E.; Janey, N.; Payrastre, O.

    2015-12-01

    No consensus has yet been reached regarding the influence of rainfall spatial variability on runoff modelling at catchment outlets. To eliminate modelling and measurement errors, in addition to controlling rainfall variability and both the characteristics and hydrological behaviour of catchments, we propose to proceed by simulation. We have developed a simulation chain that combines a stream network model, a rainfall simulator and a distributed hydrological model (with four production functions and a distributed transfer function). Our objective here is to use this simulation chain as a simplified test bed in order to better understand the impact of the spatial variability of rainfall forcing. We applied the chain to contrasted situations involving catchments ranging from a few tens to several hundreds of square km2, thus corresponding to urban and peri-urban catchments for which surface runoff constitutes the dominant process. The results obtained confirm that the proposed simulation approach is helpful to better understand the influence of rainfall spatial variability on the catchment response. We have shown that significant dispersion exists not only between the various simulation scenarios (defined by a rainfall configuration and a catchment configuration), but also within each simulation scenario. These results show that the organisation of rainfall during the study event over the study catchment plays an important role, leading us to examine rainfall variability indexes capable of summarising the influence of rainfall spatial organisation on the catchment response. Thanks to the simulation chain, we have tested the variability indexes of Zoccatelli et al. (2010) and improved them by proposing two other indexes.

  12. Application of Hydrological Model PRMS to Simulate Daily Rainfall Runoff in Zamask-Yingluoxia Subbasin of the Heihe River Basin

    Directory of Open Access Journals (Sweden)

    Fei Teng

    2017-10-01

    Full Text Available The Precipitation-Runoff Modeling System (PRMS has been applied to simulate rainfall runoff in Zamask-Yingluoxia subbasin of the Heihe River Basin in this study. By using observed data in the subbasin, the model has been calibrated by comparing model simulations of daily stream flow to observed data at Yinglouxia station for the period of summer in 2004. Then model verification was conducted by keeping the same model parameters for the simulation of the period from 1 January 2003 to 31 December 2006. Results from model verification indicate that the model is able to provide good accuracy of simulations of daily rainfall runoff and river flow at Yinglouxia station, with a Nash-Sutcliffe Efficiency coefficient of 0.90 and the root-mean-square error of 15.7 m3/s. The error of maximum peak flow is 6.9 m3/s (1.8% and the error of mean flow is 1.4 m3/s (2.5%. Comparing to previous studies, results indicate the improvement of model accuracy in simulations of daily rainfall runoff. The calibrated and verified hydrological model can be used to support flood hazard mitigations and water resource management in the Zamask-Yingluoxia subbasin.

  13. [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

  14. Improving catchment scale water quality modelling with continuous high resolution monitoring of metals in runoff

    Science.gov (United States)

    Saari, Markus; Rossi, Pekka; Blomberg von der Geest, Kalle; Mäkinen, Ari; Postila, Heini; Marttila, Hannu

    2017-04-01

    High metal concentrations in natural waters is one of the key environmental and health problems globally. Continuous in-situ analysis of metals from runoff water is technically challenging but essential for the better understanding of processes which lead to pollutant transport. Currently, typical analytical methods for monitoring elements in liquids are off-line laboratory methods such as ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy) and ICP-MS (ICP combined with a mass spectrometer). Disadvantage of the both techniques is time consuming sample collection, preparation, and off-line analysis at laboratory conditions. Thus use of these techniques lack possibility for real-time monitoring of element transport. We combined a novel high resolution on-line metal concentration monitoring with catchment scale physical hydrological modelling in Mustijoki river in Southern Finland in order to study dynamics of processes and form a predictive warning system for leaching of metals. A novel on-line measurement technique based on micro plasma emission spectroscopy (MPES) is tested for on-line detection of selected elements (e.g. Na, Mg, Al, K, Ca, Fe, Ni, Cu, Cd and Pb) in runoff waters. The preliminary results indicate that MPES can sufficiently detect and monitor metal concentrations from river water. Water and Soil Assessment Tool (SWAT) catchment scale model was further calibrated with high resolution metal concentration data. We show that by combining high resolution monitoring and catchment scale physical based modelling, further process studies and creation of early warning systems, for example to optimization of drinking water uptake from rivers, can be achieved.

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

    Science.gov (United States)

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

    1994-01-01

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

  16. Tank Model Application for Runoff and Infiltration Analysis on Sub-Watersheds in Lalindu River in South East Sulawesi Indonesia

    Science.gov (United States)

    Wirdhana Ahmad, Sitti

    2017-05-01

    Improper land management often causes flood, this is due to uncontrolled runoff. Runoff is affected by the management of the land cover. The phenomena also occurred in South East Sulawesi, Indonesia. This study aims to analyze the flow rate of water in watershed of Lalindu River in North Konawe, South East Sulawesi by using a Tank Model. The model determined the magnitude of the hydrologic runoff, infiltration capacity and soil water content several land uses were evaluated in the study area. The experimental and calculation results show that the runoff in the forest is 2,639.21 mm/year, in the reed is 2,517.05 mm/year, in the oil palm with a slope more than 45% is 2,715.36 mm/year, and in the oil palm with slopes less than 45% is 2,709.59 mm/year. Infiltration in the forest is 30.70 mm/year, in the reed is 7.51 mm/year, in the palm oil with a slope more than 45% is 24.13 mm/year and in the palm oil with slopes less than 45% is 29.67 mm/year. Runoff contributes to stream flow for water availability.

  17. Implementation of new sub-grid runoff parameterization within the Weather Research and Forecasting (WRF) modeling system

    Science.gov (United States)

    Khodamorad poor, M.; Irannejad, P.

    2012-04-01

    Runoff is an important component of the water cycle in land surface parameterization schemes, whose estimation is very difficult because of its dependence on rainfall, soil moisture, and topography, which vary temporally and spatially. In this study, two different methods of sub-grid parameterization of runoff are tested within the WRF numerical weather forecast model. The land surface scheme originally used in WRF is NOAH, in which runoff is parameterized based on the probably distributed function (PDF) of soil infiltration capacity. The river discharge calculated from WRF-NOAH simulated runoff and routed using total runoff integrating pathways (TRIP) model for three sub-basins of Karoon River, in the southwestern Iran, including Soosan, Harmaleh and Farseat is compared with observations for the winter 2006. WRF-NOAH extremely underestimates the discharge in the Karoon River basin, probably because of uncertainties in the runoff parameterization, which is in turn due to unavailability of soil infiltration data needed to estimate the shape and parameters of the PDF of the infiltration capacity. For this reason, we modified NOAH (NOAH-SIM) by substituting the infiltration capacity dependent runoff parameterization with a parameterization based on the PDF of the topographic index, following the philosophy used in the simplified TOPMODEL. As the topographic index is scale dependent, high resolution of topographic indices (10 m) are derived from digital elevation data model in low resolution (1000 m) by using a downscaling method. Evaluation of stimulated discharge by the two land surface schemes (NOAH-SIM, NOAH) coupled in WRF, with observed discharge proves improved runoff simulation by NOAH-SIM in all the three sub-basins. Compared to NOAH, NOAH-SIM simulated discharge has lower bias, smaller mean absolute error, higher efficiency coefficient, and a standard deviation closer to that observed. Coupling NOAH-SIM with WRF not only improves runoff simulations, but also

  18. Linking collection of stormwater runoff to managed aquifer recharge using a geographic information system and hydrologic modeling

    Science.gov (United States)

    Teo, E. K.; Young, K. S.; Beganskas, S.; Fisher, A. T.; Lozano, S.; Weir, W. B.; Harmon, R. E.

    2016-12-01

    We are completing a regional analysis of Santa Cruz and northern Monterey Counties, CA to assess conditions for using distributed stormwater collection to support managed aquifer recharge (DSC-MAR). DSC-MAR constitutes an important component in a portfolio of innovative techniques being developed in order to improve groundwater management and to adapt to prolonged drought and changes in climate and anthropogenic water demands by increasing recharge during and soon after winter precipitation events, the season when excess water is most abundant. Our analyses focus specifically on the distributed collection of stormwater runoff, a source that has historically been treated as a nuisance, with the goal of infiltrating ≥100 ac-ft/yr within individual projects. The first part of this project is a spatial analysis, using a geographic information system to combine surface and subsurface data. There is complete spatial coverage for most surface data (elevation, soil and bedrock properties, land use) for the full study region ( 1,400 km2), but subsurface data (aquifer distribution, properties, and storage space) are available for only 43% of the region. Sites that are most suitable for DSC-MAR have high soil infiltration capacity, are well-connected to an underlying aquifer with good transmissive and storage properties, and have space to receive water. Based on surface data, 35% of the region is suitable for MAR (480 km2). In contrast, 14% of the area for which both surface and subsurface datasets are available is suitable for MAR (84 km2). We have assessed the availability of hillslope runoff for collection in support of MAR using a distributed hydrologic model (PRMS) and a catalog of historical, high-resolution climate data. In the simulations, enclosed topographic basins are divided into hydrologic response units (HRUs) having an area of 25 to 250 acres (0.1 to 1 km2). Simulations of the San Lorenzo River Basin (SLRB), northern Santa Cruz County, suggest that during

  19. 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.

  20. Analysis of regional rainfall-runoff parameters for the Lake Michigan Diversion hydrological modeling

    Science.gov (United States)

    Soong, David T.; Over, Thomas M.

    2015-01-01

    The Lake Michigan Diversion Accounting (LMDA) system has been developed by the U.S. Army Corps of Engineers, Chicago District (USACE-Chicago) and the State of Illinois as a part of the interstate Great Lakes water regulatory program. The diverted Lake Michigan watershed is a 673-square-mile watershed that is comprised of the Chicago River and Calumet River watersheds. They originally drained into Lake Michigan, but now flow to the Mississippi River watershed via three canals constructed in the Chicago area in the early twentieth century. Approximately 393 square miles of the diverted watershed is ungaged, and the runoff from the ungaged portion of the diverted watershed has been estimated by the USACE-Chicago using the Hydrological Simulation Program-FORTRAN (HSPF) program. The accuracy of simulated runoff depends on the accuracy of the parameter set used in the HSPF program. Nine parameter sets comprised of the North Branch, Little Calumet, Des Plaines, Hickory Creek, CSSC, NIPC, 1999, CTE, and 2008 have been developed at different time periods and used by the USACE-Chicago. In this study, the U.S. Geological Survey and the USACE-Chicago collaboratively analyzed the parameter sets using nine gaged watersheds in or adjacent to the diverted watershed to assess the predictive accuracies of selected parameter sets. Six of the parameter sets, comprising North Branch, Hickory Creek, NIPC, 1999, CTE, and 2008, were applied to the nine gaged watersheds for evaluating their simulation accuracy from water years 1996 to 2011. The nine gaged watersheds were modeled by using the three LMDA land-cover types (grass, forest, and hydraulically connected imperviousness) based on the 2006 National Land Cover Database, and the latest meteorological and precipitation data consistent with the current (2014) LMDA modeling framework.

  1. Assessing the effects of urbanization on annual runoff and flood events using an integrated hydrological modeling system for Qinhuai River basin, China

    Science.gov (United States)

    Du, Jinkang; Qian, Li; Rui, Hanyi; Zuo, Tianhui; Zheng, Dapeng; Xu, Youpeng; Xu, C.-Y.

    2012-09-01

    SummaryThis study developed and used an integrated modeling system, coupling a distributed hydrologic and a dynamic land-use change model, to examine effects of urbanization on annual runoff and flood events of the Qinhuai River watershed in Jiangsu Province, China. The Hydrologic Engineering Center's Hydrologic Modeling System (HEC-HMS) was used to calculate runoff generation and the integrated Markov Chain and Cellular Automata model (CA-Markov model) was used to develop future land use maps. The model was calibrated and validated using observed daily streamflow data collected at the two outlets of watershed. Landsat Thematic Mapper (TM) images from 1988, 1994, 2006, Enhanced Thematic Mapper Plus (ETM+) images from 2001, 2003 and a China-Brazil Earth Resources Satellite (CBERS) image from 2009 were used to obtain historical land use maps. These imageries revealed that the watershed experienced conversion of approximately 17% non-urban area to urban area between 1988 and 2009. The urbanization scenarios for various years were developed by overlaying impervious surfaces of different land use maps to 1988 (as a reference year) map sequentially. The simulation results of HEC-HMS model for the various urbanization scenarios indicate that annual runoff, daily peak flow, and flood volume have increased to different degrees due to urban expansion during the study period (1988-2009), and will continue to increase as urban areas increase in the future. When impervious ratios change from 3% (1988) to 31% (2018), the mean annual runoff would increase slightly and the annual runoff in the dry year would increase more than that in the wet year. The daily peak discharge of eight selected floods would increase from 2.3% to 13.9%. The change trend of flood volumes is similar with that of peak discharge, but with larger percentage changes than that of daily peak flows in all scenarios. Sensitivity analysis revealed that the potential changes in peak discharge and flood volume with

  2. Tracing Temporal Changes of Model Parameters in Rainfall-Runoff Modeling via a Real-Time Data Assimilation

    Directory of Open Access Journals (Sweden)

    Shanshan Meng

    2016-01-01

    Full Text Available Watershed characteristics such as patterns of land use and land cover (LULC, soil structure and river systems, have substantially changed due to natural and anthropogenic factors. To adapt hydrological models to the changing characteristics of watersheds, one of the feasible strategies is to explicitly estimate the changed parameters. However, few approaches have been dedicated to these non-stationary conditions. In this study, we employ an ensemble Kalman filter (EnKF technique with a constrained parameter evolution scheme to trace the parameter changes. This technique is coupled to a rainfall-runoff model, i.e., the Xinanjiang (XAJ model. In addition to a stationary condition, we designed three typical non-stationary conditions, including sudden, gradual and rotational changes with respect to two behavioral parameters of the XAJ. Synthetic experiments demonstrated that the EnKF-based method can trace the three types of parameter changes in real time. This method shows robust performance even for the scenarios of high-level uncertainties within rainfall input, modeling and observations, and it holds an implication for detecting changes in watershed characteristics. Coupling this method with a rainfall-runoff model is useful to adapt the model to non-stationary conditions, thereby improving flood simulations and predictions.

  3. Implication of remotely sensed data to incorporate land cover effect into a linear reservoir-based rainfall-runoff model

    Science.gov (United States)

    Nourani, Vahid; Fard, Ahmad Fakheri; Niazi, Faegheh; Gupta, Hoshin V.; Goodrich, David C.; Kamran, Khalil Valizadeh

    2015-10-01

    This study investigates the effect of land use on the Geomorphological Cascade of Unequal linear Reservoirs (GCUR) model using the Normalized Difference Vegetation Index (NDVI) derived from remotely sensed data as a measure of land use. The proposed modeling has two important aspects: it considers the effects of both watershed geomorphology and land use/cover, and it requires only one parameter to be estimated through the use of observed rainfall-runoff data. Geographic Information System (GIS) tools are employed to determine the parameters associated with watershed geomorphology, and the Vegetation Index parameter is extracted from historical Landsat images. The modeling is applied via three formulations to a watershed located in Southeastern Arizona, which consists of two gaged sub-watersheds with different land uses. The results show that while all of the formulations generate forecasts of the basin outlet hydrographs with acceptable accuracy, only the two formulations that consider the effects of land cover (using NDVI) provide acceptable results at the outlets of the sub-watersheds.

  4. Modelling runoff and soil water content with the DR2-2013© SAGA v1.1 model at catchment scale under Mediterranean conditions (NE Spain)

    Science.gov (United States)

    López-Vicente, Manuel, , Dr.; Palazón, M. Sc. Leticia; Quijano, M. Sc. Laura; Gaspar, Leticia, , Dr.; Navas, Ana, , Dr.

    2015-04-01

    Hydrological and soil erosion models allow mapping and quantifying spatially distributed rates of runoff depth and soil redistribution for different land uses, management and tillage practices and climatic scenarios. The different temporal and spatial [very small (1000 km2)] scales of numerical simulations make model selection specific to each range of scales. Additionally, the spatial resolution of the inputs is in agreement with the size of the study area. In this study, we run the GIS-based water balance DR2-2013© SAGA v1.1 model (freely downloaded as executable file at http://digital.csic.es/handle/10261/93543), in the Vandunchil stream catchment (23 km2; Ebro river basin, NE Spain). All input maps are generated at 5 x 5 m of cell size (924,573 pixels per map) allowing sound parameterization. Simulation is run at monthly scale with average climatic values. This catchment is an open hydrological system and it has a long history of human occupation, agricultural practices and water management. Numerous manmade infrastructures or landscape linear elements (LLEs: paved and unpaved trails, rock mounds in non-cultivated areas, disperse and small settlements, shallow and long drainage ditches, stone walls, small rock dams, fences and vegetation strips) appear throughout the hillslopes and streams and modify the natural runoff pathways and thus the hydrological and sediment connectivity. Rain-fed cereal fields occupy one third of the catchment area, 1% corresponds to sealed soils, and the remaining area is covered with Mediterranean forest, scrubland, pine afforestation and meadow. The parent material corresponds to Miocene sandstones and lutites and Holocene colluvial and alluvial deposits. The climate is continental Mediterranean with two humid periods, one in spring and a second in autumn that summarizes 63% of the total annual precipitation. We created a synthetic weather station (WS) from the Caseda and Uncastillo WS. The effective rainfall that reaches the soils

  5. Simulating endosulfan transport in runoff from cotton fields in Australia with the GLEAMS model.

    Science.gov (United States)

    Connolly, R D; Kennedy, I R; Silburn, D M; Simpson, B W; Freebairn, D M

    2001-01-01

    Endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,4,3-benzodioxathiepin 3-oxide), a pesticide that is highly toxic to aquatic organisms, is widely used in the cotton (Gossypium hirsutum L.) industry in Australia and is a risk to the downstream riverine environment. We used the GLEAMS model to evaluate the effectiveness of a range of management scenarios aimed at minimizing endosulfan transport in runoff at the field scale. The field management scenarios simulated were (i) Conventional, bare soil at the beginning of the cotton season and seven irrigations per season; (ii) Improved Irrigation, irrigation amounts reduced and frequency increased to reduce runoff from excess irrigation; (iii) Dryland, no irrigation; (iv) Stubble Retained, increased soil cover created by retaining residue from the previous crop or a specially planted winter cover crop; and (v) Reduced Sprays, a fewer number of sprays. Stubble Retained was the most effective scenario for minimizing endosulfan transport because infiltration was increased and erosion reduced, and the stubble intercepted and neutralized a proportion of the applied endosulfan. Reducing excess irrigation reduced annual export rates by 80 to 90%, but transport in larger storm events was still high. Reducing the number of pesticide applications only reduced transport when three or fewer sprays were applied. We conclude that endosulfan transport from cotton farms can be minimized with a combination of field management practices that reduce excess irrigation and concentration of pesticide on the soil at any point in time; however, discharges, probably with endosulfan concentrations exceeding guideline values, will still occur in storm events.

  6. Bayesian Assessment of the Uncertainties of Estimates of a Conceptual Rainfall-Runoff Model Parameters

    Science.gov (United States)

    Silva, F. E. O. E.; Naghettini, M. D. C.; Fernandes, W.

    2014-12-01

    This paper evaluated the uncertainties associated with the estimation of the parameters of a conceptual rainfall-runoff model, through the use of Bayesian inference techniques by Monte Carlo simulation. The Pará River sub-basin, located in the upper São Francisco river basin, in southeastern Brazil, was selected for developing the studies. In this paper, we used the Rio Grande conceptual hydrologic model (EHR/UFMG, 2001) and the Markov Chain Monte Carlo simulation method named DREAM (VRUGT, 2008a). Two probabilistic models for the residues were analyzed: (i) the classic [Normal likelihood - r ≈ N (0, σ²)]; and (ii) a generalized likelihood (SCHOUPS & VRUGT, 2010), in which it is assumed that the differences between observed and simulated flows are correlated, non-stationary, and distributed as a Skew Exponential Power density. The assumptions made for both models were checked to ensure that the estimation of uncertainties in the parameters was not biased. The results showed that the Bayesian approach proved to be adequate to the proposed objectives, enabling and reinforcing the importance of assessing the uncertainties associated with hydrological modeling.

  7. Flood modelling with a distributed event-based parsimonious rainfall-runoff model: case of the karstic Lez river catchment

    Directory of Open Access Journals (Sweden)

    M. Coustau

    2012-04-01

    Full Text Available Rainfall-runoff models are crucial tools for the statistical prediction of flash floods and real-time forecasting. This paper focuses on a karstic basin in the South of France and proposes a distributed parsimonious event-based rainfall-runoff model, coherent with the poor knowledge of both evaporative and underground fluxes. The model combines a SCS runoff model and a Lag and Route routing model for each cell of a regular grid mesh. The efficiency of the model is discussed not only to satisfactorily simulate floods but also to get powerful relationships between the initial condition of the model and various predictors of the initial wetness state of the basin, such as the base flow, the Hu2 index from the Meteo-France SIM model and the piezometric levels of the aquifer. The advantage of using meteorological radar rainfall in flood modelling is also assessed. Model calibration proved to be satisfactory by using an hourly time step with Nash criterion values, ranging between 0.66 and 0.94 for eighteen of the twenty-one selected events. The radar rainfall inputs significantly improved the simulations or the assessment of the initial condition of the model for 5 events at the beginning of autumn, mostly in September–October (mean improvement of Nash is 0.09; correction in the initial condition ranges from −205 to 124 mm, but were less efficient for the events at the end of autumn. In this period, the weak vertical extension of the precipitation system and the low altitude of the 0 °C isotherm could affect the efficiency of radar measurements due to the distance between the basin and the radar (~60 km. The model initial condition S is correlated with the three tested predictors (R2 > 0.6. The interpretation of the model suggests that groundwater does not affect the first peaks of the flood, but can strongly impact subsequent peaks in the case of a multi-storm event. Because this kind of model is based on a limited

  8. A meteo-hydrological modelling system for the reconstruction of river runoff: the case of the Ofanto river catchment

    Directory of Open Access Journals (Sweden)

    G. Verri

    2017-10-01

    Full Text Available A meteo-hydrological modelling system has been designed for the reconstruction of long time series of rainfall and river runoff events. The modelling chain consists of the mesoscale meteorological model of the Weather Research and Forecasting (WRF, the land surface model NOAH-MP and the hydrology–hydraulics model WRF-Hydro. Two 3-month periods are reconstructed for winter 2011 and autumn 2013, containing heavy rainfall and river flooding events. Several sensitivity tests were performed along with an assessment of which tunable parameters, numerical choices and forcing data most impacted on the modelling performance.The calibration of the experiments highlighted that the infiltration and aquifer coefficients should be considered as seasonally dependent.The WRF precipitation was validated by a comparison with rain gauges in the Ofanto basin. The WRF model was demonstrated to be sensitive to the initialization time and a spin-up of about 1.5 days was needed before the start of the major rainfall events in order to improve the accuracy of the reconstruction. However, this was not sufficient and an optimal interpolation method was developed to correct the precipitation simulation. It is based on an objective analysis (OA and a least square (LS melding scheme, collectively named OA+LS. We demonstrated that the OA+LS method is a powerful tool to reduce the precipitation uncertainties and produce a lower error precipitation reconstruction that itself generates a better river discharge time series. The validation of the river streamflow showed promising statistical indices.The final set-up of our meteo-hydrological modelling system was able to realistically reconstruct the local rainfall and the Ofanto hydrograph.

  9. Enhancements to the Precipitation-Runoff Modeling System for simulating in-stream water temperature

    Science.gov (United States)

    Markstrom, S. L.; Hay, L.

    2010-12-01

    A stream temperature module has been developed for the U.S. Geological Survey Precipitation-Runoff Modeling System (PRMS) for simulating maximum- and mean-daily stream temperature. This module provides additional simulation capabilities by coupling PRMS with the U.S. Geological Survey Stream Network Temperature (SNTEMP) model. PRMS is a modular, deterministic, distributed-parameter, physical-process watershed model that simulates watershed response to various combinations of climate and land use. Normal and extreme rainfall and snowmelt can be simulated to evaluate changes in water-balance relations, streamflow regimes, soil-water relations, and ground-water recharge. SNTEMP was developed to help aquatic biologists and engineers predict the effects of flow regime changes on water temperatures. This coupling of PRMS with SNTEMP will allow scientists and watershed managers to evaluate the effects of historical climate and projected climate change, landscape evolution, and resource management scenarios on watershed hydrology and in-stream water temperature. The prototype of this coupled model was developed for the U.S. Geological Survey Southeast Regional Assessment Project (SERAP) and tested in the Apalachicola-Chattahoochee-Flint River Basin in the southeastern United States. Preliminary results from the prototype are presented.

  10. Automated Simulation Model Generation

    NARCIS (Netherlands)

    Huang, Y.

    2013-01-01

    One of today's challenges in the field of modeling and simulation is to model increasingly larger and more complex systems. Complex models take long to develop and incur high costs. With the advances in data collection technologies and more popular use of computer-aided systems, more data has become

  11. A modified slope-dependent formulation for groundwater runoff in a regional climate model

    Science.gov (United States)

    Schlemmer, Linda; Strebel, Lukas; Keller, Michael; Lüthi, Daniel; Schär, Christoph

    2017-04-01

    Soil moisture influences the state of the overlying atmosphere considerably and thus plays a major role in the climate system. Its spatial distribution is strongly modulated by the underlying orography. Yet, the vertical transport of soil water and especially the drainage at the bottom of the soil column is currently treated in a very crude way in most atmospheric models. This potentially leads to large biases in near-surface temperatures during summertime as the soil dries out and induces elevation-dependent biases in climate simulations. We present a modified formulation for the groundwater runoff formation in the regional climate model COSMO-CLM (multi-layer soil model TERRA_ML). It is based on Darcy's law, allows for saturated aquifers and includes a slope-dependent discharge. Employing flux limiters ensures a physically consistent treatment. An implementation of this formulation into TERRA_ML is tested and validated both in idealized and real-case simulations for cloud-resolving as well as hydrostatic scales. Idealized simulations display a physically meaningful recharge and discharge of the saturated zone and exhibit a closed water budget. Decade-long climate simulations over Europe exhibit a more realistic representation of the groundwater distribution in mountainous areas, an improved annual cycle of surface latent heat fluxes and as a consequence reductions of the long-standing bias in near-surface temperatures in semi-arid regions.

  12. Conditioning rainfall-runoff model parameters for ungauged catchments and land management impacts analysis

    Directory of Open Access Journals (Sweden)

    N. Bulygina

    2009-06-01

    Full Text Available Data scarcity and model over-parameterisation, leading to model equifinality and large prediction uncertainty, are common barriers to effective hydrological modelling. The problem can be alleviated by constraining the prior parameter space using parameter regionalisation. A common basis for regionalisation in the UK is the HOST database which provides estimates of hydrological indices for different soil classifications. In our study, Base Flow Index is estimated from the HOST database and the power of this index for constraining the parameter space is explored. The method is applied to a highly discretised distributed model of a 12.5 km2 upland catchment in Wales. To assess probabilistic predictions against flow observations, a probabilistic version of the Nash-Sutcliffe efficiency is derived. For six flow gauges with reliable data, this efficiency ranged between 0.70 and 0.81, and inspection of the results shows that the model explains the data well. Knowledge of how Base Flow Index and interception losses may change under future land use management interventions was then used to further condition the model. Two interventions are considered: afforestation of grazed areas, and soil degradation associated with increased grazing intensity. Afforestation leads to median reduction in modelled runoff volume of 24% over the simulated 3 month period; and a median peak flow reduction ranging from 12 to 15% over the six gauges for the largest simulated event. Uncertainty in all results is low compared to prior uncertainty and it is concluded that using Base Flow Index estimated from HOST is a simple and potentially powerful method of conditioning the parameter space under current and future land management.

  13. Modeling detailed hydro-meteorological surfaces and runoff response in large diverse watersheds

    International Nuclear Information System (INIS)

    Byrne, J.; Kienzle, S.W.; MacDonald, R.J.

    2008-01-01

    An understanding of local variability in climatic conditions over complex terrain is imperative to making accurate assessments of impacts from climate change on fresh water ecosystems (Daly, 2006). The derivation of representative spatial data in diverse environments poses a significant challenge to the modelling community. This presentation describes the current status of a long term ongoing hydro-climate model development program. We are developing a gridded hydroclimate dataset for diverse watersheds using SimGrid (Larson, 2008; Lapp et al., 2005; Sheppard, 1996), a model that applies the Mountain Climate Model (MTCLIM; Hungerford et al., 1989) to simulate hydro-climatic conditions over diverse terrain. The model uses GIS based terrain categories (TC) classified by slope, aspect, elevation, and soil water storage. SimGrid provides daily estimates of solar radiation, air temperature, relative humidity, precipitation, snowpack and soil water storage over space. Earlier versions of the model have been applied in the St. Mary (Larson, 2008) and upper Oldman basins (Lapp et al., 2005), giving realistic estimates of hydro-climatic variables. The current study demonstrates improvements to the estimation of temperature, precipitation, snowpack, soil water storage and runoff from the basin. Soil water storage data for the upper drainage were derived with GIS and included in SimGrid to estimate soil water flux over the time period. These changes help improve the estimation of spatial climatic variability over the basin while accounting for topographical influence. In further work we will apply spatial hydro-climatic surfaces from the SimGrid model to assess the hydrologic response to environmental change for watersheds in Canada and beyond. (author)

  14. Simulation of daily streamflow for nine river basins in eastern Iowa using the Precipitation-Runoff Modeling System

    Science.gov (United States)

    Haj, Adel E.; Christiansen, Daniel E.; Hutchinson, Kasey J.

    2015-10-14

    The U.S. Geological Survey, in cooperation with the Iowa Department of Natural Resources, constructed Precipitation-Runoff Modeling System models to estimate daily streamflow for nine river basins in eastern Iowa that drain into the Mississippi River. The models are part of a suite of methods for estimating daily streamflow at ungaged sites. The Precipitation-Runoff Modeling System is a deterministic, distributed- parameter, physical-process-based modeling system developed to evaluate the response of streamflow and general drainage basin hydrology to various combinations of climate and land use. Calibration and validation periods used in each basin mostly were October 1, 2002, through September 30, 2012, but differed depending on the period of record available for daily mean streamflow measurements at U.S. Geological Survey streamflow-gaging stations.

  15. Application of Volumetric Weather Radar Data and the Distributed Rainfall Runoff Model REW in the Ourthe Catchment

    Science.gov (United States)

    Hazenberg, P.; Leijnse, H.; Torfs, P.; Uijlenhoet, R.; Weerts, A.; Reggiani, P.; Delobbe, L.

    2008-12-01

    In the southern Ardennes region of Belgium near the border with Luxembourg, the Royal Meteorological Institute of Belgium (RMI) installed a C-band Doppler weather radar at an elevation of 600 m in the year 2001. This volumetric weather radar scans over multiple elevations at a temporal resolution of 5 minutes. The current study explores the possibility of using the volumetric information of the precipitation field to correct for the effects of the Vertical Profile of Reflectivity (VPR) over the period October 1, 2002 until March 31, 2003. During this winter half year storm events are mainly stratiform, giving rise to bright band effects which can decrease the performance of the radar. Previous studies have shown multiple drawbacks in applying a single estimated VPR profile to correct such reflectivity data. Therefore, the focus here is on the temporal variability of the VPR as measured by the radar and its variability over different spatial scales. This information is applied to generate a number of possible rainfall fields. These realizations are employed to try to quantify some of the discrepancies in precipitation intensities as estimated by the weather radar and those measured by a raingauge network. The final step then is to assess their potential within a distributed rainfall runoff model. The 1597 km2 Ourthe catchment lies within 60 km of the radar. Over this medium sized watershed ten raingauges measuring at an hourly interval are more or less equally distributed. Near the outlet discharge data are collected at the same time step. The distributed hydrological Representative Elementary Watershed (REW) model is applied to model the hydrological behavior of the Ourthe over the six month period. The benefits of the high spatial and temporal resolution of weather radar data compared to a conventional raingauge network plus the possibility of generating multiple realizations of the precipitation field are expected to yield more information about the hydrological

  16. LDMS: A Low-Dimensional Modeling System for Hillslope, Catchment and River-Basin Runoff

    National Research Council Canada - National Science Library

    Duffy, Christopher

    2000-01-01

    .... The approach assumes that soil moisture and saturated groundwater storage serve as essential state variables in the rainfall-runoff process and that natural variations in topography, drainage area...

  17. Risk assessment and adaptive runoff utilization in water resource system considering the complex relationship among water supply, electricity generation and environment

    Science.gov (United States)

    Zhou, J.; Zeng, X.; Mo, L.; Chen, L.; Jiang, Z.; Feng, Z.; Yuan, L.; He, Z.

    2017-12-01

    Generally, the adaptive utilization and regulation of runoff in the source region of China's southwest rivers is classified as a typical multi-objective collaborative optimization problem. There are grim competitions and incidence relation in the subsystems of water supply, electricity generation and environment, which leads to a series of complex problems represented by hydrological process variation, blocked electricity output and water environment risk. Mathematically, the difficulties of multi-objective collaborative optimization focus on the description of reciprocal relationships and the establishment of evolving model of adaptive systems. Thus, based on the theory of complex systems science, this project tries to carry out the research from the following aspects: the changing trend of coupled water resource, the covariant factor and driving mechanism, the dynamic evolution law of mutual feedback dynamic process in the supply-generation-environment coupled system, the environmental response and influence mechanism of coupled mutual feedback water resource system, the relationship between leading risk factor and multiple risk based on evolutionary stability and dynamic balance, the transfer mechanism of multiple risk response with the variation of the leading risk factor, the multidimensional coupled feedback system of multiple risk assessment index system and optimized decision theory. Based on the above-mentioned research results, the dynamic method balancing the efficiency of multiple objectives in the coupled feedback system and optimized regulation model of water resources is proposed, and the adaptive scheduling mode considering the internal characteristics and external response of coupled mutual feedback system of water resource is established. In this way, the project can make a contribution to the optimal scheduling theory and methodology of water resource management under uncertainty in the source region of Southwest River.

  18. Characterization and modeling of turbidity density plume induced into stratified reservoir by flood runoffs.

    Science.gov (United States)

    Chung, S W; Lee, H S

    2009-01-01

    In monsoon climate area, turbidity flows typically induced by flood runoffs cause numerous environmental impacts such as impairment of fish habitat and river attraction, and degradation of water supply efficiency. This study was aimed to characterize the physical dynamics of turbidity plume induced into a stratified reservoir using field monitoring and numerical simulations, and to assess the effect of different withdrawal scenarios on the control of downstream water quality. Three different turbidity models (RUN1, RUN2, RUN3) were developed based on a two-dimensional laterally averaged hydrodynamic and transport model, and validated against field data. RUN1 assumed constant settling velocity of suspended sediment, while RUN2 estimated the settling velocity as a function of particle size, density, and water temperature to consider vertical stratification. RUN3 included a lumped first-order turbidity attenuation rate taking into account the effects of particles aggregation and degradable organic particles. RUN3 showed best performance in replicating the observed variations of in-reservoir and release turbidity. Numerical experiments implemented to assess the effectiveness of different withdrawal depths showed that the alterations of withdrawal depth can modify the pathway and flow regimes of the turbidity plume, but its effect on the control of release water quality could be trivial.

  19. Solar Irradiance from GOES Albedo performance in a Hydrologic Model Simulation of Snowmelt Runoff

    Science.gov (United States)

    Sumargo, E.; Cayan, D. R.; McGurk, B. J.

    2015-12-01

    In many hydrologic modeling applications, solar radiation has been parameterized using commonly available measures, such as the daily temperature range, due to scarce in situ solar radiation measurement network. However, these parameterized estimates often produce significant biases. Here we test hourly solar irradiance derived from the Geostationary Operational Environmental Satellite (GOES) visible albedo product, using several established algorithms. Focusing on the Sierra Nevada and White Mountain in California, we compared the GOES irradiance and that from a traditional temperature-based algorithm with incoming irradiance from pyranometers at 19 stations. The GOES based estimates yielded 21-27% reduction in root-mean-squared error (average over 19 sites). The derived irradiance is then prescribed as an input to Precipitation-Runoff Modeling System (PRMS). We constrain our experiment to the Tuolumne River watershed and focus our attention on the winter and spring of 1996-2014. A root-mean-squared error reduction of 2-6% in daily inflow to Hetch Hetchy at the lower end of the Tuolumne catchment was achieved by incorporating the insolation estimates at only 8 out of 280 Hydrologic Response Units (HRUs) within the basin. Our ongoing work endeavors to apply satellite-derived irradiance at each individual HRU.

  20. Performance of a coupled lagged ensemble weather and river runoff prediction model system for the Alpine Ammer River catchment

    Science.gov (United States)

    Smiatek, G.; Kunstmann, H.; Werhahn, J.

    2012-04-01

    The Ammer River catchment located in the Bavarian Ammergau Alps and alpine forelands, Germany, represents with elevations reaching 2185 m and annual mean precipitation between1100 and 2000 mm a very demanding test ground for a river runoff prediction system. Large flooding events in 1999 and 2005 motivated the development of a physically based prediction tool in this area. Such a tool is the coupled high resolution numerical weather and river runoff forecasting system AM-POE that is being studied in several configurations in various experiments starting from the year 2005. Corner stones of the coupled system are the hydrological water balance model WaSiM-ETH run at 100 m grid resolution, the numerical weather prediction model (NWP) MM5 driven at 3.5 km grid cell resolution and the Perl Object Environment (POE) framework. POE implements the input data download from various sources, the input data provision via SOAP based WEB services as well as the runs of the hydrology model both with observed and with NWP predicted meteorology input. The one way coupled system utilizes a lagged ensemble prediction system (EPS) taking into account combination of recent and previous NWP forecasts. Results obtained in the years 2005-2011 reveal that river runoff simulations depict high correlation with observed runoff when driven with monitored observations in hindcast experiments. The ability to runoff forecasts is depending on lead times in the lagged ensemble prediction and shows still limitations resulting from errors in timing and total amount of the predicted precipitation in the complex mountainous area. The presentation describes the system implementation, and demonstrates the application of the POE framework in networking, distributed computing and in the setup of various experiments as well as long term results of the system application in the years 2005 - 2011.

  1. Generative models for chemical structures.

    Science.gov (United States)

    White, David; Wilson, Richard C

    2010-07-26

    We apply recently developed techniques for pattern recognition to construct a generative model for chemical structure. This approach can be viewed as ligand-based de novo design. We construct a statistical model describing the structural variations present in a set of molecules which may be sampled to generate new structurally similar examples. We prevent the possibility of generating chemically invalid molecules, according to our implicit hydrogen model, by projecting samples onto the nearest chemically valid molecule. By populating the input set with molecules that are active against a target, we show how new molecules may be generated that will likely also be active against the target.

  2. Modeling climate change effects on runoff and soil erosion in southeastern Arizona rangelands and implications for mitigation with rangeland conservation practices

    Science.gov (United States)

    Climate change is expected to impact runoff and soil erosion on rangelands in the southwestern United States. This study was done to evaluate the potential impacts of precipitation changes on soil erosion and surface runoff in southeastern Arizona using seven GCM models with three emission scenarios...

  3. Simulations of future runoff conditions for glacierized catchments in the Ötztal Alps (Austria) using the physically based hydroclimatological model AMUNDSEN

    Science.gov (United States)

    Hanzer, Florian; Förster, Kristian; Marke, Thomas; Strasser, Ulrich

    2016-04-01

    Assessing the amount of water resources stored in mountain catchments as snow and ice as well as the timing of meltwater production and the resulting streamflow runoff is of high interest for glaciohydrological investigations and hydropower production. Climate change induced seasonal shifts in snow and ice melt will alter the hydrological regimes in glacierized catchments in terms of both timing and magnitude of discharge. We present the setup of the hydroclimatological model AMUNDSEN for a highly glacierized (24 %) 558 km2 large study area (1760-3768 m a.s.l.) in the Ötztal Alps (Austria), and first results of simulated future runoff conditions. The study region comprises the headwater catchments of the valleys Ötztal, Pitztal, and Kaunertal, which contribute to the streamflow of the river Inn. AMUNDSEN is a fully distributed physically based model designed to quantify the energy and mass balance of snow and ice surfaces in complex topography as well as streamflow generation for a given catchment. The model has been extensively validated for past conditions and has been extended by an empirical glacier evolution model (Δh approach) for the present study. Statistically downscaled EURO-CORDEX climate simulations covering the RCP4.5 and RCP8.5 scenarios are used as the meteorological forcing for the period 2006-2050. Model results are evaluated in terms of magnitude and change of the contributions of the individual runoff components (snowmelt, ice melt, rain) in the subcatchments as well as the change in glacier volume and area.

  4. Developing a stochastic conflict resolution model for urban runoff quality management: Application of info-gap and bargaining theories

    Science.gov (United States)

    Ghodsi, Seyed Hamed; Kerachian, Reza; Estalaki, Siamak Malakpour; Nikoo, Mohammad Reza; Zahmatkesh, Zahra

    2016-02-01

    In this paper, two deterministic and stochastic multilateral, multi-issue, non-cooperative bargaining methodologies are proposed for urban runoff quality management. In the proposed methodologies, a calibrated Storm Water Management Model (SWMM) is used to simulate stormwater runoff quantity and quality for different urban stormwater runoff management scenarios, which have been defined considering several Low Impact Development (LID) techniques. In the deterministic methodology, the best management scenario, representing location and area of LID controls, is identified using the bargaining model. In the stochastic methodology, uncertainties of some key parameters of SWMM are analyzed using the info-gap theory. For each water quality management scenario, robustness and opportuneness criteria are determined based on utility functions of different stakeholders. Then, to find the best solution, the bargaining model is performed considering a combination of robustness and opportuneness criteria for each scenario based on utility function of each stakeholder. The results of applying the proposed methodology in the Velenjak urban watershed located in the northeastern part of Tehran, the capital city of Iran, illustrate its practical utility for conflict resolution in urban water quantity and quality management. It is shown that the solution obtained using the deterministic model cannot outperform the result of the stochastic model considering the robustness and opportuneness criteria. Therefore, it can be concluded that the stochastic model, which incorporates the main uncertainties, could provide more reliable results.

  5. A COMPARATIVE STUDY ON CALIBRATION METHODS OF NASH’S RAINFALL-RUNOFF MODEL TO AMMAMEH WATERSHED, IRAN

    Directory of Open Access Journals (Sweden)

    Vahid Nourani

    2008-06-01

    Full Text Available Increasing importance of watershed management during last decades highlighted the need for sufficient data and accurate estimation of rainfall and runoff within watersheds. Therefore, various conceptual models have been developed with parameters based on observed data. Since further investigations depend on these parameters, it is important to accurately estimate them. This study by utilizing various methods, tries to estimate Nash rainfall-runoff model parameters and then evaluate the reliability of parameter estimation methods; moment, least square error, maximum likelihood, maximum entropy and genetic algorithm. Results based on a case study on the data from Ammameh watershed in Central Iran, indicate that the genetic algorithm method, which has been developed based on artificial intelligence, more accurately estimates Nash’s model parameters.

  6. Application of the Precipitation Runoff Modeling System to measure impacts of forest fire on watershed hydrology

    Science.gov (United States)

    Driscoll, J. M.

    2015-12-01

    Precipitation in the southwestern United States falls primarily in areas of higher elevation. Drought conditions over the past five years have limited snowpack and rainfall, increasing the vulnerability to and frequency of forest fires in these montane regions. In June 2012, the Little Bear fire burned approximately 69 square miles (44,200 acres) in high-elevation forests of the Rio Hondo headwater catchments, south-central New Mexico. Burn severity was high or moderate on 53 percent of the burn area. The Precipitation Runoff Modeling System (PRMS) is a publically-available watershed model developed by the U.S. Geological Survey (USGS). PRMS data are spatially distributed using a 'Geospatial Fabric' developed at a national scale to define Hydrologic Response Units (HRUs), based on topography and points of interest (such as confluences and streamgages). The Little Bear PRMS study area is comprised of 22 HRUs over a 587 square-mile area contributing to the Rio Hondo above Chavez Canyon streamgage (USGS ID 08390020), in operation from 2008 to 2014. Model input data include spatially-distributed climate data from the National Aeronautics and Space Administration (NASA) DayMet and land cover (such as vegetation and soil properties) data from the USGS Geo Data Portal. Remote sensing of vegetation over time has provided a spatial distribution of recovery and has been applied using dynamic parameters within PRMS on the daily timestep over the study area. Investigation into the source and timing of water budget components in the Rio Hondo watershed may assist water planners and managers in determining how the surface-water and groundwater systems will react to future land use/land cover changes. Further application of PRMS in additional areas will allow for comparison of streamflow before and following wildfire conditions, and may lead to better understanding of the changes in watershed-scale hydrologic processes in the Southwest through post-fire watershed recovery.

  7. Modelling the impact of retention–detention units on sewer surcharge and peak and annual runoff reduction

    DEFF Research Database (Denmark)

    Locatelli, Luca; Gabriel, S.; Mark, O.

    2015-01-01

    Stormwater management using water sensitive urban design is expected to be part of future drainage systems. This paper aims to model the combination of local retention units, such as soakaways, with subsurface detention units. Soakaways are employed to reduce (by storage and infiltration) peak...... and volume stormwater runoff; however, large retention volumes are required for a significant peak reduction. Peak runoff can therefore be handled by combining detention units with soakaways. This paper models the impact of retrofitting retention-detention units for an existing urbanized catchment in Denmark....... The impact of retrofitting a retention-detention unit of 3.3 m(3)/100 m(2) (volume/impervious area) was simulated for a small catchment in Copenhagen using MIKE URBAN. The retention-detention unit was shown to prevent flooding from the sewer for a 10-year rainfall event. Statistical analysis of continuous...

  8. Wave Generation in Physical Models

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Frigaard, Peter

    The present book describes the most important aspects of wave generation techniques in physical models. Moreover, the book serves as technical documentation for the wave generation software AwaSys 6, cf. Aalborg University (2012). In addition to the two main authors also Tue Hald and Michael...

  9. Green roof rainfall-runoff modelling: is the comparison between conceptual and physically based approaches relevant?

    Science.gov (United States)

    Versini, Pierre-Antoine; Tchiguirinskaia, Ioulia; Schertzer, Daniel

    2017-04-01

    Green roofs are commonly considered as efficient tools to mitigate urban runoff as they can store precipitation, and consequently provide retention and detention performances. Designed as a compromise between water holding capacity, weight and hydraulic conductivity, their substrate is usually an artificial media differentiating significantly from a traditional soil. In order to assess green roofs hydrological performances, many models have been developed. Classified into two categories (conceptual and physically based), they are usually applied to reproduce the discharge of a particular monitored green roof considered as homogeneous. Although the resulted simulations could be satisfactory, the question of robustness and consistency of the calibrated parameters is often not addressed. Here, a modeling framework has been developed to assess the efficiency and the robustness of both modelling approaches (conceptual and physically based) in reproducing green roof hydrological behaviour. SWMM and VS2DT models have been used for this purpose. This work also benefits from an experimental setup where several green roofs differentiated by their substrate thickness and vegetation cover are monitored. Based on the data collected for several rainfall events, it has been studied how the calibrated parameters are effectively linked to their physical properties and how they can vary from one green roof configuration to another. Although both models reproduce correctly the observed discharges in most of the cases, their calibrated parameters exhibit a high inconsistency. For a same green roof configuration, these parameters can vary significantly from one rainfall event to another, even if they are supposed to be linked to the green roof characteristics (roughness, residual moisture content for instance). They can also be different from one green roof configuration to another although the implemented substrate is the same. Finally, it appears very difficult to find any

  10. Application of the Precipitation Runoff Modeling System to evaluate water budgets after forest fuel management

    Science.gov (United States)

    Anderson, A. M.; Micheletty, P. D.; Kinoshita, A. M.; Hogue, T. S.

    2014-12-01

    The Sagehen Experimental Forest is being used as a prototype for forest fuel management to mitigate severe wildfires and improve ecosystem function and habitat. Sagehen is located at the headwaters of Sagehen Creek and contributes to the Truckee River, which is the main water supply for Reno, Nevada. Sagehen is a snow-dominated basin that receives an average annual rainfall of 892 mm and streamflow of 392 mm. A standardized precipitation index (SPI) indicates eight wet years and three dry years occurred since 1978. The Precipitation Runoff Modeling System (PRMS) is utilized to run scenarios of fuel treatments and to analyze corresponding water budget changes in Sagehen. PRMS is calibrated to observed streamflow using the systematic multi-objective, step-wise calibration software Let Us Calibrate (LUCA). The basin is divided into 128 hydrologic response units (HRUs) based on similar hydrologic and physical characteristics. Fuel management will include multiple thinning and burning treatments based on topography and ecosystem characteristics and coincides with approximately 41 percent of the defined HRUs. Three treatment scenarios were run for relevant HRUs for water years 1981-2000. Scenarios reflect a 25, 50, and 75 percent vegetation reduction by altering sensitive parameters such as summer and winter cover density, summer and winter rain-interception storage capacity, and snow-interception storage capacity. Preliminary analysis shows changes in the water budget exemplified by simulated streamflow compared to baseline simulations. Ongoing work includes investigating PRMS outputs such as evapotranspiration, snow, and recharge to fully understand the scope of proposed fuel management in Sagehen. Individual assessment of impacted HRUs will also provide insight on specific treatment types and ultimately provide insight for future regional treatments in the Sierra Nevada.

  11. Use of the STORM model for estimating the quantity and quality of runoff from the metropolitan area of Houston, Texas

    Science.gov (United States)

    Waddell, Kidd M.; Massey, Bernard C.; Jennings, Marshall E.

    1979-01-01

    The "STORM" model, developed by the U.S. Army Corps of Engineers, was selected from existing models and adapted to use available data to compute runoff from the Houston, Texas, area and to compute the loads and concentrations of biochemicaloxygen demand, dissolved solids, total phosphorus, total organic carbon, total nitrogen, and fecal-coliform bacteria. The water-quality data simulated by the STORM model will be used by the Texas Department of Water Resources to refine and verify a model of the Calveston Bay estuarine system. 

  12. Modelling the Potential of Integrated Vegetation Bands (IVB to Retain Stormwater Runoff on Steep Hillslopes of Southeast Queensland, Australia

    Directory of Open Access Journals (Sweden)

    Justin G. Ryan

    2015-08-01

    Full Text Available Rainfall intensity is predicted to increase under a changing climate, leading to increased risks of hillslope erosion, downstream sedimentation and flooding. For many catchments used for grazing and agricultural land uses, it will become increasingly important to maintain ecohydrological functioning despite climatic extremes. One means to achieve this is through strategic reforestation using locally endemic species, in spatial configurations that effectively intercept, retain or and redistribute overland flows. This paper adopts a modelling approach for investigating the potential of one such design termed “integrated vegetation bands” (IVB, to increase the retention of runoff across steep hillslopes, particularly in the sub-tropics where rainstorms are becoming increasingly intense. A spatially distributed simulation model (MIKE-SHE was applied to a steep, grazed catchment (Maronghi Creek catchment, Southeast Queensland, Australia to compare stormwater runoff characteristics between: (1 the existing pasture land cover; and (2 a series of hypothetical IVB added across this pasture land. The IVB were approximately 20 m wide, and configured at 5% gradient towards ridgelines. Results for estimates of overland flow depth and infiltration (spatial, and accumulative water balance (temporal, confirm that the area of hillslope retaining > 10 mm/day more runoff increased by 22% under IVB compared to the pasture land use. Excluding the IVB themselves, the area of hillslope where runoff retention increased was 11%. During the most intense rainfall, IVB held up to 25% greater water depth and had 10% greater infiltration at the hillslope scale. At the sub-catchment scale, discharge decreased by 7% and infiltration increased by 23%. The findings for sub-tropical landscapes presented here are consistent with studies conducted in temperate regions. Based on the results of this preliminary modelling work, the IVB concept has been established as a paired

  13. Applying volumetric weather radar data for rainfall runoff modeling: The importance of error correction.

    Science.gov (United States)

    Hazenberg, P.; Leijnse, H.; Uijlenhoet, R.; Delobbe, L.; Weerts, A.; Reggiani, P.

    2009-04-01

    In the current study half a year of volumetric radar data for the period October 1, 2002 until March 31, 2003 is being analyzed which was sampled at 5 minutes intervals by C-band Doppler radar situated at an elevation of 600 m in the southern Ardennes region, Belgium. During this winter half year most of the rainfall has a stratiform character. Though radar and raingauge will never sample the same amount of rainfall due to differences in sampling strategies, for these stratiform situations differences between both measuring devices become even larger due to the occurrence of a bright band (the point where ice particles start to melt intensifying the radar reflectivity measurement). For these circumstances the radar overestimates the amount of precipitation and because in the Ardennes bright bands occur within 1000 meter from the surface, it's detrimental effects on the performance of the radar can already be observed at relatively close range (e.g. within 50 km). Although the radar is situated at one of the highest points in the region, very close to the radar clutter is a serious problem. As a result both nearby and farther away, using uncorrected radar results in serious errors when estimating the amount of precipitation. This study shows the effect of carefully correcting for these radar errors using volumetric radar data, taking into account the vertical reflectivity profile of the atmosphere, the effects of attenuation and trying to limit the amount of clutter. After applying these correction algorithms, the overall differences between radar and raingauge are much smaller which emphasizes the importance of carefully correcting radar rainfall measurements. The next step is to assess the effect of using uncorrected and corrected radar measurements on rainfall-runoff modeling. The 1597 km2 Ourthe catchment lies within 60 km of the radar. Using a lumped hydrological model serious improvement in simulating observed discharges is found when using corrected radar

  14. Investigation of changes in rainfall-runoff process in a hilly basin using different modelling tools

    Czech Academy of Sciences Publication Activity Database

    Buchtele, Josef; Buchtelová, Marie; Cissé, Youssouf

    2002-01-01

    Roč. 50, č. 3 (2002), s. 185-197 ISSN 0042-790X R&D Projects: GA AV ČR IAA3060002 Institutional research plan: CEZ:AV0Z2060917 Keywords : rainfall-runoff process * land use changes Subject RIV: DA - Hydrology ; Limnology

  15. Modelling gas generation for landfill.

    Science.gov (United States)

    Chakma, Sumedha; Mathur, Shashi

    2017-06-01

    A methodology was developed to predict the optimum long-term spatial and temporal generation of landfill gases such as methane, carbon dioxide, ammonia, and hydrogen sulphide on post-closure landfill. The model incorporated the chemical and the biochemical processes responsible for the degradation of the municipal solid waste. The developed model also takes into account the effects of heterogeneity with different layers as observed at the site of landfills' morphology. The important parameters for gas generation due to biodegradation such as temperature, pH, and moisture content were incorporated. The maximum and the minimum generations of methane and hydrogen sulphide were observed. The rate of gas generation was found almost same throughout the depth after 30 years of landfill closure. The proposed model would be very useful for landfill engineering in the mining landfill gas and proper design for landfill gas management systems.

  16. Optimizing low impact development (LID) for stormwater runoff treatment in urban area, Korea: Experimental and modeling approach.

    Science.gov (United States)

    Baek, Sang-Soo; Choi, Dong-Ho; Jung, Jae-Woon; Lee, Hyung-Jin; Lee, Hyuk; Yoon, Kwang-Sik; Cho, Kyung Hwa

    2015-12-01

    Currently, continued urbanization and development result in an increase of impervious areas and surface runoff including pollutants. Also one of the greatest issues in pollutant emissions is the first flush effect (FFE), which implies a greater discharge rate of pollutant mass in the early part in the storm. Low impact development (LID) practices have been mentioned as a promising strategy to control urban stormwater runoff and pollution in the urban ecosystem. However, this requires many experimental and modeling efforts to test LID characteristics and propose an adequate guideline for optimizing LID management. In this study, we propose a novel methodology to optimize the sizes of different types of LID by conducting intensive stormwater monitoring and numerical modeling in a commercial site in Korea. The methodology proposed optimizes LID size in an attempt to moderate FFE on a receiving waterbody. Thereby, the main objective of the optimization is to minimize mass first flush (MFF), which is an indicator for quantifying FFE. The optimal sizes of 6 different LIDs ranged from 1.2 mm to 3.0 mm in terms of runoff depths, which significantly moderate the FFE. We hope that the new proposed methodology can be instructive for establishing LID strategies to mitigate FFE. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2017-12-01

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

  18. Simulation of daily streamflow for 12 river basins in western Iowa using the Precipitation-Runoff Modeling System

    Science.gov (United States)

    Christiansen, Daniel E.; Haj, Adel E.; Risley, John C.

    2017-10-24

    The U.S. Geological Survey, in cooperation with the Iowa Department of Natural Resources, constructed Precipitation-Runoff Modeling System models to estimate daily streamflow for 12 river basins in western Iowa that drain into the Missouri River. The Precipitation-Runoff Modeling System is a deterministic, distributed-parameter, physical-process-based modeling system developed to evaluate the response of streamflow and general drainage basin hydrology to various combinations of climate and land use. Calibration periods for each basin varied depending on the period of record available for daily mean streamflow measurements at U.S. Geological Survey streamflow-gaging stations.A geographic information system tool was used to delineate each basin and estimate initial values for model parameters based on basin physical and geographical features. A U.S. Geological Survey automatic calibration tool that uses a shuffled complex evolution algorithm was used for initial calibration, and then manual modifications were made to parameter values to complete the calibration of each basin model. The main objective of the calibration was to match daily discharge values of simulated streamflow to measured daily discharge values. The Precipitation-Runoff Modeling System model was calibrated at 42 sites located in the 12 river basins in western Iowa.The accuracy of the simulated daily streamflow values at the 42 calibration sites varied by river and by site. The models were satisfactory at 36 of the sites based on statistical results. Unsatisfactory performance at the six other sites can be attributed to several factors: (1) low flow, no flow, and flashy flow conditions in headwater subbasins having a small drainage area; (2) poor representation of the groundwater and storage components of flow within a basin; (3) lack of accounting for basin withdrawals and water use; and (4) limited availability and accuracy of meteorological input data. The Precipitation-Runoff Modeling System

  19. Plot and field scale soil moisture dynamics and subsurface wetness control on runoff generation in a headwater in the Ore Mountains

    Directory of Open Access Journals (Sweden)

    E. Zehe

    2010-06-01

    Full Text Available This study presents an application of an innovative sampling strategy to assess soil moisture dynamics in a headwater of the Weißeritz in the German eastern Ore Mountains. A grassland site and a forested site were instrumented with two Spatial TDR clusters (STDR that consist of 39 and 32 coated TDR probes of 60 cm length. Distributed time series of vertically averaged soil moisture data from both sites/ensembles were analyzed by statistical and geostatistical methods. Spatial variability and the spatial mean at the forested site were larger than at the grassland site. Furthermore, clustering of TDR probes in combination with long-term monitoring allowed identification of average spatial covariance structures at the small field scale for different wetness states. The correlation length of soil water content as well as the sill to nugget ratio at the grassland site increased with increasing average wetness and but, in contrast, were constant at the forested site. As soil properties at both the forested and grassland sites are extremely variable, this suggests that the correlation structure at the forested site is dominated by the pattern of throughfall and interception. We also found a very strong correlation between antecedent soil moisture at the forested site and runoff coefficients of rainfall-runoff events observed at gauge Rehefeld. Antecedent soil moisture at the forest site explains 92% of the variability in the runoff coefficients. By combining these results with a recession analysis we derived a first conceptual model of the dominant runoff mechanisms operating in this catchment. Finally, we employed a physically based hydrological model to shed light on the controls of soil- and plant morphological parameters on soil average soil moisture at the forested site and the grassland site, respectively. A homogeneous soil setup allowed, after fine tuning of plant morphological parameters, most of the time unbiased predictions of the observed

  20. Evaluating the effectiveness of management practices on hydrology and water quality at watershed scale with a rainfall-runoff model.

    Science.gov (United States)

    Liu, Yaoze; Bralts, Vincent F; Engel, Bernard A

    2015-04-01

    The adverse influence of urban development on hydrology and water quality can be reduced by applying best management practices (BMPs) and low impact development (LID) practices. This study applied green roof, rain barrel/cistern, bioretention system, porous pavement, permeable patio, grass strip, grassed swale, wetland channel, retention pond, detention basin, and wetland basin, on Crooked Creek watershed. The model was calibrated and validated for annual runoff volume. A framework for simulating BMPs and LID practices at watershed scales was created, and the impacts of BMPs and LID practices on water quantity and water quality were evaluated with the Long-Term Hydrologic Impact Assessment-Low Impact Development 2.1 (L-THIA-LID 2.1) model for 16 scenarios. The various levels and combinations of BMPs/LID practices reduced runoff volume by 0 to 26.47%, Total Nitrogen (TN) by 0.30 to 34.20%, Total Phosphorus (TP) by 0.27 to 47.41%, Total Suspended Solids (TSS) by 0.33 to 53.59%, Lead (Pb) by 0.30 to 60.98%, Biochemical Oxygen Demand (BOD) by 0 to 26.70%, and Chemical Oxygen Demand (COD) by 0 to 27.52%. The implementation of grass strips in 25% of the watershed where this practice could be applied was the most cost-efficient scenario, with cost per unit reduction of $1m3/yr for runoff, while cost for reductions of two pollutants of concern was $445 kg/yr for Total Nitrogen (TN) and $4871 kg/yr for Total Phosphorous (TP). The scenario with very high levels of BMP and LID practice adoption (scenario 15) reduced runoff volume and pollutant loads from 26.47% to 60.98%, and provided the greatest reduction in runoff volume and pollutant loads among all scenarios. However, this scenario was not as cost-efficient as most other scenarios. The L-THIA-LID 2.1 model is a valid tool that can be applied to various locations to help identify cost effective BMP/LID practice plans at watershed scales. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Nonlinear effects of microtopography on macroscopic rainfall-runoff partitioning a the hillslope scale: a modelling study

    Science.gov (United States)

    Caviedes-Voullième, Daniel; Domin, Andrea; Hinz, Christoph

    2017-04-01

    The quantitative description and prediction of hydrological response of hillslopes or hillslope-scale catchments to rainfall events is becoming evermore relevant. At the hillslope scale, the onset of runoff and the overall rainfall-runoff transformation are controlled by multiple interacting small-scale processes, that, when acting together produce a response described in terms of hydrological variables well-defined at the catchment and hillslope scales. We hypothesize that small scale features such microtopography of the land surface will will govern large scale signatures of temporal runoff evolution. This can be tested directly by numerical modelling of well-defined surface geometries and adequate process description. It requires a modelling approach consistent with fundamental fluid mechanics, well-designed numerical methods, and computational efficiency. In this work, an idealized rectangular domain representing a hillslope with an idealized 2D sinusoidal microtopography is studied by simulating surface water redistribution by means of a 2D diffusive-wave (zero-inertia) shallow water model. By studying more than 500 surfaces and performing extensive sensitivity analysis forced by a single rainfall pulse, the dependency of characteristic hydrological responses to microtopographical properties was assessed. Despite of the simplicity of periodic surface and the rain event, results indicate complex surface flow dynamics during the onset of runoff observed at the macro and micro scales. Macro scale regimes were defined in terms of characteristics hydrograph shapes and those were related to surface geometry. The reference regime was defined for smooth topography and consisted of a simple hydrograph with smoothly rising and falling limbs with an intermediate steady state. In constrast, rough surface geometry yields stepwise rising limbs and shorter steady states. Furthermore, the increase in total infiltration over the whole domain relative to the smooth reference

  2. Generative Anatomy Modeling Language (GAML).

    Science.gov (United States)

    Demirel, Doga; Yu, Alexander; Baer-Cooper, Seth; Halic, Tansel; Bayrak, Coskun

    2017-12-01

    This paper presents the Generative Anatomy Modeling Language (GAML) for generating variation of 3D virtual human anatomy in real-time. This framework provides a set of operators for modification of a reference base 3D anatomy. The perturbation of the 3D models is satisfied with nonlinear geometry constraints to create an authentic human anatomy. GAML was used to create 3D difficult anatomical scenarios for virtual simulation of airway management techniques such as Endotracheal Intubation (ETI) and Cricothyroidotomy (CCT). Difficult scenarios for each technique were defined and the model variations procedurally created with GAML. This study presents details of the GAML design, set of operators, types of constraints. Cases of CCT and ETI difficulty were generated and confirmed by expert surgeons. Execution performance pertaining to an increasing complexity of constraints using nonlinear programming was in real-time execution. Copyright © 2017 John Wiley & Sons, Ltd.

  3. Phenomenological Model of Vortex Generators

    DEFF Research Database (Denmark)

    Hansen, Martin Otto Laver; Westergaard, C.

    1995-01-01

    For some time attempts have been made to improve the power curve of stall regulated wind turbines by using devices like vortex generators VG and Gurney flaps. The vortex produces an additional mixing of the boundary layer and the free stream and thereby increasing the momentum close to the wall......, which again delays separation in adverse pressure gradient regions. A model is needed to include the effect of vortex generators in numerical computations of the viscous flow past rotors. In this paper a simple model is proposed....

  4. Runoff response for a peri-urban watershed in the Atlantic Forest Biome, southern Brazil, using the Kineros2 model

    Science.gov (United States)

    Beling, F. A.; Dias de Paiva, J.; Cauduro Dias de Paiva, E. M.; Heatwole, C.

    2011-12-01

    Simulating the hydrologic response of a watershed for different scenarios is an important tool for assessing the rational use of the land and natural resources, especially in environments where urbanization is not ever an organized procedure. This study used the Kineros2 event oriented hydrological model to simulate the runoff response of a 4.9 km2 peri-urban basin located in the Atlantic Forest biome in Southern Brazil, with 47% of the area being impermeable. The goal of the simulations was to estimate the characteristic parameters of the soils and land cover of the watershed to then enable the prediction of basin response for different land uses. To acheive this objective, the responses of ten measured rainfall-runoff events were used to calibrate five parameters of the model. The PEST (Model-Independent Parameter Estimation and Uncertainty Analysis) package was used for automatic calibration of the model parameters. The quality of results is shown in Nash-Sutcliffe efficiency index values varying from 0.64 up to 0.98, with an average value of 0.88. The average absolute error in the simulated peak flow was 4.5% and 20.7% in the simulated runoff volume. A cross-validation using the same events used in the calibration and using average values of the calibrated parameters. gave Nash-Sutcliffe index values varying from 0.26 up to 0.92, with an average value of 0.73. The average absolute error in the simulated peak flow and runoff volume were 22.7% and 25.6%, respectively. We used two validated events to simulate distinct scenarios, being representative of a wet and of dry antecedent moisture conditions. For a scenario of a totally forested land cover, the simulated peak flow and runoff volume for a dry condition changed -53% and -46% respectively, and for a wet condition, -63% and -41% respectively, relatively to the present land use. For a complete pasture land use, the simulated peak flow and runoff volume for a dry condition changed -31% and -27% respectively and

  5. Using isotopes to constrain water flux and age estimates in snow-influenced catchments using the STARR (Spatially distributed Tracer-Aided Rainfall-Runoff) model

    Science.gov (United States)

    Ala-aho, Pertti; Tetzlaff, Doerthe; McNamara, James P.; Laudon, Hjalmar; Soulsby, Chris

    2017-10-01

    Tracer-aided hydrological models are increasingly used to reveal fundamentals of runoff generation processes and water travel times in catchments. Modelling studies integrating stable water isotopes as tracers are mostly based in temperate and warm climates, leaving catchments with strong snow influences underrepresented in the literature. Such catchments are challenging, as the isotopic tracer signals in water entering the catchments as snowmelt are typically distorted from incoming precipitation due to fractionation processes in seasonal snowpack. We used the Spatially distributed Tracer-Aided Rainfall-Runoff (STARR) model to simulate fluxes, storage, and mixing of water and tracers, as well as estimating water ages in three long-term experimental catchments with varying degrees of snow influence and contrasting landscape characteristics. In the context of northern catchments the sites have exceptionally long and rich data sets of hydrometric data and - most importantly - stable water isotopes for both rain and snow conditions. To adapt the STARR model for sites with strong snow influence, we used a novel parsimonious calculation scheme that takes into account the isotopic fractionation through snow sublimation and snowmelt. The modified STARR setup simulated the streamflows, isotope ratios, and snow pack dynamics quite well in all three catchments. From this, our simulations indicated contrasting median water ages and water age distributions between catchments brought about mainly by differences in topography and soil characteristics. However, the variable degree of snow influence in catchments also had a major influence on the stream hydrograph, storage dynamics, and water age distributions, which was captured by the model. Our study suggested that snow sublimation fractionation processes can be important to include in tracer-aided modelling for catchments with seasonal snowpack, while the influence of fractionation during snowmelt could not be unequivocally

  6. The last developments of the airGR R-package, an open source software for rainfall-runoff modelling

    Science.gov (United States)

    Thirel, Guillaume; Delaigue, Olivier; Coron, Laurent; Perrin, Charles; Andréassian, Vazken

    2017-04-01

    Lumped hydrological models are useful and convenient tools for research, engineering and educational purposes. They propose catchment-scale representations of the precipitation-discharge relationship. Thanks to their limited data requirements, they can be easily implemented and run. With such models, it is possible to simulate a number of hydrological key processes over the catchment with limited structural and parametric complexity, typically evapotranspiration, runoff, underground losses, etc. The Hydrology Group at Irstea (Antony) has been developing a suite of rainfall-runoff models over the past 30 years with the main objectives of designing models as efficient as possible in terms of streamflow simulation, applicable to a wide range of catchments and having low data requirements. This resulted in a suite of models running at different time steps (from hourly to annual) applicable for various issues including water balance estimation, forecasting, simulation of impacts and scenario testing. Recently, Irstea has developed an easy-to-use R-package (R Core Team, 2016), called airGR (Coron et al., 2016, 2017), to make these models widely available. It includes: - the water balance annual GR1A model, - the monthly GR2M model, - three versions of the daily model, namely GR4J, GR5J and GR6J, - the hourly GR4H model, - a degree-day snow model CemaNeige. The airGR package has been designed to facilitate the use by non-expert users and allow the addition of evaluation criteria, models or calibration algorithm selected by the end-user. Each model core is coded in FORTRAN to ensure low computational time. The other package functions (i.e. mainly the calibration algorithm and the efficiency criteria) are coded in R. The package is also used for educational purposes. It allows for convenient implementation of model inter-comparisons and large sample hydrology experiments. The airGR package undergoes continuous developments for improving the efficiency, computational time

  7. ISLSCP II UNH/GRDC Composite Monthly Runoff

    Data.gov (United States)

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

  8. Modeling of a PEFC generator

    OpenAIRE

    CHNANI, M; MAKER, H; PERA, MC; CANDUSSO, D; HISSEL, D

    2005-01-01

    Polymer electrolyte fuel cell is an alternative technology for powering electrical vehicles. As simulation is a binding milestone to develop efficient power train, a fuel cell generator model has been developed with this aim in view. The electrical response is considered as quasi-static state series, according to a semi-empirical approach. The hydraulic behaviour of the fluid line components is based on an electrical analogy. They are represented by RC circuits. Parameters of the model are id...

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

    Science.gov (United States)

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

    2016-12-01

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

  10. Impact of rainfall spatial distribution on rainfall-runoff modelling efficiency and initial soil moisture conditions estimation

    Directory of Open Access Journals (Sweden)

    Y. Tramblay

    2011-01-01

    Full Text Available A good knowledge of rainfall is essential for hydrological operational purposes such as flood forecasting. The objective of this paper was to analyze, on a relatively large sample of flood events, how rainfall-runoff modeling using an event-based model can be sensitive to the use of spatial rainfall compared to mean areal rainfall over the watershed. This comparison was based not only on the model's efficiency in reproducing the flood events but also through the estimation of the initial conditions by the model, using different rainfall inputs. The initial conditions of soil moisture are indeed a key factor for flood modeling in the Mediterranean region. In order to provide a soil moisture index that could be related to the initial condition of the model, the soil moisture output of the Safran-Isba-Modcou (SIM model developed by Météo-France was used. This study was done in the Gardon catchment (545 km2 in South France, using uniform or spatial rainfall data derived from rain gauge and radar for 16 flood events. The event-based model considered combines the SCS runoff production model and the Lag and Route routing model. Results show that spatial rainfall increases the efficiency of the model. The advantage of using spatial rainfall is marked for some of the largest flood events. In addition, the relationship between the model's initial condition and the external predictor of soil moisture provided by the SIM model is better when using spatial rainfall, in particular when using spatial radar data with R2 values increasing from 0.61 to 0.72.

  11. Model of reverse steam generator

    International Nuclear Information System (INIS)

    Malasek, V.; Manek, O.; Masek, V.; Riman, J.

    1987-01-01

    The claim of Czechoslovak discovery no. 239272 is a model designed for the verification of the properties of a reverse steam generator during the penetration of water, steam-water mixture or steam into liquid metal flowing inside the heat exchange tubes. The design may primarily be used for steam generators with a built-in inter-tube structure. The model is provided with several injection devices configured in different heat exchange tubes, spaced at different distances along the model axis. The design consists in that between the pressure and the circumferential casings there are transverse partitions and that in one chamber consisting of the circumferential casings, pressure casing and two adjoining partitions there is only one passage of the injection device through the inter-tube space. (Z.M.). 1 fig

  12. Watershed Runoff Model Uncertainty as affected by Spatial Climate Data Resolution for McKenzie River, OR

    Science.gov (United States)

    Epps, T. H.; Chang, H.; Jung, I.; Nolin, A. W.; Roth, T.

    2012-12-01

    Climate change and the potential impacts that it will have on water resources must be assessed through watershed modeling and forecasting to guide effective management strategies that will accommodate future uncertainty in climate patterns. Watershed modeling is a valuable method to assess potential changes in the timing and quantity of streamflow and the impacts that shifts in streamflow dynamics may have on the availability of local water resources. This has been observed for the Pacific Northwest's Willamette River Basin (WRB) in previous studies that display substantial potential for local changes in streamflow due to a changing climate. Precipitation Runoff Modeling System (PRMS), a semi-distributed physically-based hydrologic model, was used to simulate runoff in sub-basins of the Willamette River that originate in the Cascades region of Oregon. These sub-basins have displayed high sensitivity to parameters associated with snowpack accumulation and evolution processes due to larger annual snowfall amounts than in lower elevations. Snowpack acts as a temporal storage for hydrologic inputs in these sub-basins and snowpack evolution processes, subject to ambient climate conditions, influence the timing of streamflows and the seasonal resiliency of water resources in these areas. Accuracy in modeling these snowpack processes is important in forecasting changes in streamflow timing and magnitude that will occur under climate change scenarios. PRMS models snowpack evolution using daily measurements of precipitation, solar radiation, and the maximum and minimum temperatures. Measured precipitation is apportioned between rainfall and snowfall based on measured daily temperature ranges and spatial parameters linked to topography and land cover. The McKenzie River (MCK) sub-basin of the WRB has its headwaters in the high Cascades region and is influenced by annual snowpack accumulation and snowmelt processes. This study will assess the uncertainty in PRMS modeling

  13. Statistics for stochastic modeling of volume reduction, hydrograph extension, and water-quality treatment by structural stormwater runoff best management practices (BMPs)

    Science.gov (United States)

    Granato, Gregory E.

    2014-01-01

    The U.S. Geological Survey (USGS) developed the Stochastic Empirical Loading and Dilution Model (SELDM) in cooperation with the Federal Highway Administration (FHWA) to indicate the risk for stormwater concentrations, flows, and loads to be above user-selected water-quality goals and the potential effectiveness of mitigation measures to reduce such risks. SELDM models the potential effect of mitigation measures by using Monte Carlo methods with statistics that approximate the net effects of structural and nonstructural best management practices (BMPs). In this report, structural BMPs are defined as the components of the drainage pathway between the source of runoff and a stormwater discharge location that affect the volume, timing, or quality of runoff. SELDM uses a simple stochastic statistical model of BMP performance to develop planning-level estimates of runoff-event characteristics. This statistical approach can be used to represent a single BMP or an assemblage of BMPs. The SELDM BMP-treatment module has provisions for stochastic modeling of three stormwater treatments: volume reduction, hydrograph extension, and water-quality treatment. In SELDM, these three treatment variables are modeled by using the trapezoidal distribution and the rank correlation with the associated highway-runoff variables. This report describes methods for calculating the trapezoidal-distribution statistics and rank correlation coefficients for stochastic modeling of volume reduction, hydrograph extension, and water-quality treatment by structural stormwater BMPs and provides the calculated values for these variables. This report also provides robust methods for estimating the minimum irreducible concentration (MIC), which is the lowest expected effluent concentration from a particular BMP site or a class of BMPs. These statistics are different from the statistics commonly used to characterize or compare BMPs. They are designed to provide a stochastic transfer function to approximate

  14. Hydraulic Geometry, GIS and Remote Sensing, Techniques against Rainfall-Runoff Models for Estimating Flood Magnitude in Ephemeral Fluvial Systems

    Directory of Open Access Journals (Sweden)

    Rafael Garcia-Lorenzo

    2010-11-01

    Full Text Available This paper shows the combined use of remotely sensed data and hydraulic geometry methods as an alternative to rainfall-runoff models. Hydraulic geometric data and boolean images of water sheets obtained from satellite images after storm events were integrated in a Geographical Information System. Channel cross-sections were extracted from a high resolution Digital Terrain Model (DTM and superimposed on the image cover to estimate the peak flow using HEC-RAS. The proposed methodology has been tested in ephemeral channels (ramblas on the coastal zone in south-eastern Spain. These fluvial systems constitute an important natural hazard due to their high discharges and sediment loads. In particular, different areas affected by floods during the period 1997 to 2009 were delimited through HEC-GeoRAs from hydraulic geometry data and Landsat images of these floods (Landsat‑TM5 and Landsat-ETM+7. Such an approach has been validated against rainfall-surface runoff models (SCS Dimensionless Unit Hydrograph, SCSD, Témez gamma HU Tγ and the Modified Rational method, MRM comparing their results with flood hydrographs of the Automatic Hydrologic Information System (AHIS in several ephemeral channels in the Murcia Region. The results obtained from the method providing a better fit were used to calculate different hydraulic geometry parameters, especially in residual flood areas.

  15. A model to forecast short-term snowmelt runoff using synoptic observations of streamflow, temperature, and precipitation

    Science.gov (United States)

    Tangborn, Wendell V.

    1980-01-01

    Snowmelt runoff is forecast with a statistical model that utilizes daily values of stream discharge, gaged precipitation, and maximum and minimum observations of air temperature. Synoptic observations of these variables are made at existing low- and medium-altitude weather stations, thus eliminating the difficulties and expense of new, high-altitude installations. Four model development steps are used to demonstrate the influence on prediction accuracy of basin storage, a preforecast test season, air temperature (to estimate ablation), and a prediction based on storage. Daily ablation is determined by a technique that employs both mean temperature and a radiative index. Radiation (both long- and short-wave components) is approximated by using the range in daily temperature, which is shown to be closely related to mean cloud cover. A technique based on the relationship between prediction error and prediction season weather utilizes short-term forecasts of precipitation and temperature to improve the final prediction. Verification of the model is accomplished by a split sampling technique for the 1960–1977 period. Short- term (5–15 days) predictions of runoff throughout the main snowmelt season are demonstrated for mountain drainages in western Washington, south-central Arizona, western Montana, and central California. The coefficient of prediction (Cp) based on actual, short-term predictions for 18 years is for Thunder Creek (Washington), 0.69; for South Fork Flathead River (Montana), 0.45; for the Black River (Arizona), 0.80; and for the Kings River (California), 0.80.

  16. P2S--Coupled simulation with the Precipitation-Runoff Modeling System (PRMS) and the Stream Temperature Network (SNTemp) Models

    Science.gov (United States)

    Markstrom, Steven L.

    2012-01-01

    A software program, called P2S, has been developed which couples the daily stream temperature simulation capabilities of the U.S. Geological Survey Stream Network Temperature model with the watershed hydrology simulation capabilities of the U.S. Geological Survey Precipitation-Runoff Modeling System. The Precipitation-Runoff Modeling System is a modular, deterministic, distributed-parameter, physical-process watershed model that simulates hydrologic response to various combinations of climate and land use. Stream Network Temperature was developed to help aquatic biologists and engineers predict the effects of changes that hydrology and energy have on water temperatures. P2S will allow scientists and watershed managers to evaluate the effects of historical climate and projected climate change, landscape evolution, and resource management scenarios on watershed hydrology and in-stream water temperature.

  17. Documentation of a daily mean stream temperature module—An enhancement to the Precipitation-Runoff Modeling System

    Science.gov (United States)

    Sanders, Michael J.; Markstrom, Steven L.; Regan, R. Steven; Atkinson, R. Dwight

    2017-09-15

    A module for simulation of daily mean water temperature in a network of stream segments has been developed as an enhancement to the U.S. Geological Survey Precipitation Runoff Modeling System (PRMS). This new module is based on the U.S. Fish and Wildlife Service Stream Network Temperature model, a mechanistic, one-dimensional heat transport model. The new module is integrated in PRMS. Stream-water temperature simulation is activated by selection of the appropriate input flags in the PRMS Control File and by providing the necessary additional inputs in standard PRMS input files.This report includes a comprehensive discussion of the methods relevant to the stream temperature calculations and detailed instructions for model input preparation.

  18. Using a GIS to link digital spatial data and the precipitation-runoff modeling system, Gunnison River Basin, Colorado

    Science.gov (United States)

    Battaglin, William A.; Kuhn, Gerhard; Parker, Randolph S.

    1993-01-01

    The U.S. Geological Survey Precipitation-Runoff Modeling System, a modular, distributed-parameter, watershed-modeling system, is being applied to 20 smaller watersheds within the Gunnison River basin. The model is used to derive a daily water balance for subareas in a watershed, ultimately producing simulated streamflows that can be input into routing and accounting models used to assess downstream water availability under current conditions, and to assess the sensitivity of water resources in the basin to alterations in climate. A geographic information system (GIS) is used to automate a method for extracting physically based hydrologic response unit (HRU) distributed parameter values from digital data sources, and for the placement of those estimates into GIS spatial datalayers. The HRU parameters extracted are: area, mean elevation, average land-surface slope, predominant aspect, predominant land-cover type, predominant soil type, average total soil water-holding capacity, and average water-holding capacity of the root zone.

  19. Coupling of a Detailed Snow Model to WRF-Hydro for Glacier Mass Balance and Glacier Runoff Studies

    Science.gov (United States)

    Eidhammer, T.; Gochis, D.; Barlage, M. J.; Rasmussen, R.

    2017-12-01

    Studies of mass balance in glaciers in complex terrain show that elevation gradients and complex topography in many glaciated regions lead to large variations in temperature, precipitation, winds (and thereby wind deflection, transport and deposition of dry snow during the accumulation season) and net radiative exchange across the glacier. Therefore, proper simulation of the non-homogenous, non-stationary, evolution of a glacier requires much finer resolution of atmospheric processes than typical global or regional climate models can provide. Furthermore, regional `atmosphere-only' models typically do not have the detailed information about runoff routing processes, which are important components in the hydrological cycle. Glacier melt contributes to discharge especially during summer when the magnitude of the summer peak river flow depends greatly on the contribution of melt water from snow and ice to the total river flow. This contribution from glaciers to total flow plays a key role in the glacier-fed rivers in populated regions where summer flows are crucial for irrigation, human consumption and energy production. We have incorporated the detailed Crocus snow model, as a glacier mass balance model, into the Noah-MP land model, within the Weather and Research Forecasting - Hydro (WRF-Hydro) modelling system. By linking a surface mass balance glacier model to the WRF-Hydro system (WRF-HydroGlac), the interactions between the energy, water and mass balance budgets over glaciated river basins can be better depicted and projected future impacts, better understood. We will demonstrate the WRF-HydroGlac model with a mass balance and snowpack/glacier runoff study of a highly observed Norwegian glacier (Hardangerjokulen).

  20. Laboratory, field, and modeling studies of organophosphate pesticide fate and transport during simulated rainfall-runoff events

    Science.gov (United States)

    Coelho, C. J.; Brown, D. L.; Johns, M.; Lopez, R.

    2005-12-01

    Agricultural runoff is a major source of water pollution in California. Best Management Practices (BMPs) can be used by farmers to reduce pesticides loading to surface waters. In previous studies, it has been found that the organophosphate pesticide diazinon has an affinity for sorption on carbon sources. This study used rice straw compost as a BMP to increase carbon content of orchard soils and to investigate the sorption capability of the compost. Laboratory isotherm experiments were conducted to determine the sorption capacity and equilibrium coefficients of the compost and soil. Using the Kd values of the compost and soil as well as infiltration data from previous studies, a model was created to determine the sorption capability of the compost in the field. Field experiments are in progress using a rainfall simulation system, with five controlled and five compost sites all sprayed with diazinon. Results from the field trials will be compared with the model. Preliminary results have shown that the sorption capacity of the compost could significantly reduce organophosphate pesticide runoff into water ways

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

    Directory of Open Access Journals (Sweden)

    F. Asadzadeh

    2016-02-01

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

  2. Physical basis and potential estimation techniques for soil erosion parameters in the Precipitation-Runoff Modeling System (PRMS)

    Science.gov (United States)

    Carey, W.P.; Simon, Andrew

    1984-01-01

    Simulation of upland-soil erosion by the Precipitation-Runoff Modeling System currently requires the user to estimate two rainfall detachment parameters and three hydraulic detachmment paramenters. One rainfall detachment parameter can be estimated from rainfall simulator tests. A reformulation of the rainfall detachment equation allows the second parameter to be computed directly. The three hydraulic detachment parameters consist of one exponent and two coefficients. The initial value of the exponent is generally set equal to 1.5. The two coefficients are functions of the soil 's resistance to erosion and one of the two also accounts for sediment delivery processes not simulated in the model. Initial estimates of these parameters can be derived from other modeling studies or from published empirical relations. (USGS)

  3. Distributed Modelling of Stormflow Generation: Assessing the Effect of Ground Cover

    Science.gov (United States)

    Jarihani, B.; Sidle, R. C.; Roth, C. H.; Bartley, R.; Wilkinson, S. N.

    2017-12-01

    Understanding the effects of grazing management and land cover changes on surface hydrology is important for water resources and land management. A distributed hydrological modelling platform, wflow, (that was developed as part of Deltares's OpenStreams project) is used to assess the effect of land management practices on runoff generation processes. The model was applied to Weany Creek, a small catchment (13.6 km2) of the Burdekin Basin, North Australia, which is being studied to understand sources of sediment and nutrients to the Great Barrier Reef. Satellite and drone-based ground cover data, high resolution topography from LiDAR, soil properties, and distributed rainfall data were used to parameterise the model. Wflow was used to predict total runoff, peak runoff, time of rise, and lag time for several events of varying magnitudes and antecedent moisture conditions. A nested approach was employed to calibrate the model by using recorded flow hydrographs at three scales: (1) a hillslope sub-catchment: (2) a gullied sub-catchment; and the 13.6 km2 catchment outlet. Model performance was evaluated by comparing observed and predicted stormflow hydrograph attributes using the Nash Sutcliffe efficiency metric. By using a nested approach, spatiotemporal patterns of overland flow occurrence across the catchment can also be evaluated. The results show that a process-based distributed model can be calibrated to simulate spatial and temporal patterns of runoff generation processes, to help identify dominant processes which may be addressed by land management to improve rainfall retention. The model will be used to assess the effects of ground cover changes due to management practices in grazed lands on storm runoff.

  4. A Self-Calibrating Runoff and Streamflow Remote Sensing Model for Ungauged Basins Using Open-Access Earth Observation Data

    Directory of Open Access Journals (Sweden)

    Ate Poortinga

    2017-01-01

    Full Text Available Due to increasing pressures on water resources, there is a need to monitor regional water resource availability in a spatially and temporally explicit manner. However, for many parts of the world, there is insufficient data to quantify stream flow or ground water infiltration rates. We present the results of a pixel-based water balance formulation to partition rainfall into evapotranspiration, surface water runoff and potential ground water infiltration. The method leverages remote sensing derived estimates of precipitation, evapotranspiration, soil moisture, Leaf Area Index, and a single F coefficient to distinguish between runoff and storage changes. The study produced significant correlations between the remote sensing method and field based measurements of river flow in two Vietnamese river basins. For the Ca basin, we found R2 values ranging from 0.88–0.97 and Nash–Sutcliffe efficiency (NSE values varying between 0.44–0.88. The R2 for the Red River varied between 0.87–0.93 and NSE values between 0.61 and 0.79. Based on these findings, we conclude that the method allows for a fast and cost-effective way to map water resource availability in basins with no gauges or monitoring infrastructure, without the need for application of sophisticated hydrological models or resource-intensive data.

  5. Modelling the response of soil and runoff chemistry to forest harvesting in a low deposition area (Kangasvaara, eastern Finland

    Directory of Open Access Journals (Sweden)

    J. Kämäri

    1998-01-01

    Full Text Available A simple dynamic soil model developed to analyse the effects of atmospheric deposition and nutrient cycling on terrestrial ecosystems, SMART 2, was applied to the Kangasvaara catchment in eastern Finland. Given the historical deposition and forest growth patterns and reasonable values for the input parameters, SMART 2 was calibrated successfully to reproduce present-day soil and Kangasvaara catchment on the soil and runoff water chemistry under a future deposition scenario (GRP scenario. These impacts were also compared to the effects of further reducing the deposition of sulphur and nitrate under the maximum feasible reduction (MFR scenario. The model demonstrates the consequences of breaking the nutrient cycle, and predicts that final cutting results in increased leaching of inorganic nitrogen and base cations from the cut part of the catchment for about 10 years. The resulting concentrations in the stream will depend on the ability of the buffer zones surrounding the stream to capture and utilize these nutrients.

  6. First application of the WEPP model to predict runoff and erosion risk in fire-affected volcanic areas in Europe

    Science.gov (United States)

    Neris, Jonay; Robichaud, Peter R.; Elliot, William J.; Doerr, Stefan H.; Notario del Pino, Jesús S.; Lado, Marcos

    2017-04-01

    An estimated that 15% of the world's population lives in volcanic areas. Recent catastrophic erosion events following wildfires in volcanic terrain have highlighted the geomorphological instability of this soil type under disturbed conditions and steep slopes. Predicting the hydrological and erosional response of this soils in the post-fire period is the first step to design and develop adequate actions to minimize risks in the post-fire period. In this work we apply, for the first time, the Water Erosion Prediction Project model for predicting erosion and runoff events in fire-affected volcanic soils in Europe. Two areas affected by wildfires in 2015 were selected in Tenerife (Spain) representative of different fire behaviour (downhill surface fire with long residence time vs uphill crown fire with short residence time), severity (moderate soil burn severity vs light soil burn severity) and climatic conditions (average annual precipitation of 750 and 210 mm respectively). The actual erosion processes were monitored in the field using silt fences. Rainfall and rill simulations were conducted to determine hydrologic, interrill and rill erosion parameters. The soils were sampled and key properties used as model input, evaluated. During the first 18 months after the fire 7 storms produced runoff and erosion in the selected areas. Sediment delivery reached 5.4 and 2.5 Mg ha-1 respectively in the first rainfall event monitored after the fire, figures comparable to those reported for fire-affected areas of the western USA with similar climatic conditions but lower than those showed by wetter environments. The validation of the WEPP model using field data showed reasonable estimates of hillslope sediment delivery in the post-fire period and, therefore, it is suggested that this model can support land managers in volcanic areas in Europe in predicting post-fire hydrological and erosional risks and designing suitable mitigation treatments.

  7. Component characterization and predictive modeling for green roof substrates optimized to adsorb P and improve runoff quality: A review.

    Science.gov (United States)

    Jennett, Tyson S; Zheng, Youbin

    2017-12-14

    This review is a synthesis of the current knowledge regarding the effects of green roof substrate components and their retentive capacity for nutrients, particularly phosphorus (P). Substrates may behave as either sources or sinks of P depending on the components they are formulated from, and to date, the total P-adsorbing capacity of a substrate has not been quantified as the sum of the contributions of its components. Few direct links have been established among substrate components and their physicochemical characteristics that would affect P-retention. A survey of recent literature presented herein highlights the trends within individual component selection (clays and clay-like material, organics, conventional soil and sands, lightweight inorganics, and industrial wastes and synthetics) for those most common during substrate formulation internationally. Component selection will vary with respect to ease of sourcing component materials, cost of components, nutrient-retention capacity, and environmental sustainability. However, the number of distinct components considered for inclusion in green roof substrates continues to expand, as the desires of growers, material suppliers, researchers and industry stakeholders are incorporated into decision-making. Furthermore, current attempts to characterize the most often used substrate components are also presented whereby runoff quality is correlated to entire substrate performance. With the use of well-described characterization (constant capacitance model) and modeling techniques (the soil assemblage model), it is proposed that substrates optimized for P adsorption may be developed through careful selection of components with prior knowledge of their chemical properties, that may increase retention of P in plant-available forms, thereby reducing green roof fertilizer requirements and P losses in roof runoff. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Radar rainfall estimation in a hilly environment and implications for runoff modeling

    Science.gov (United States)

    Hazenberg, Pieter; Leijnse, Hidde; Uijlenhoet, Remko

    2010-05-01

    Radars are known for their ability to obtain a wealth of information about the spatial stormfield characteristics. Unfortunately, rainfall estimates obtained by this instrument are known to be affected by multiple sources of error. Especially for stratiform precipitation systems, the quality of radar rainfall estimates starts to decrease at relatively close ranges. In the current study the hydrological potential of weather radar is analyzed during a winter half-year for the hilly region of the Belgian Ardennes. A correction algorithm is proposed taking into account attenuation, ground clutter, anomalous propagation, the vertical profile of reflectivity (VPR) and advection. No final bias correction with respect to rain gauge data were implemented, because that does not add to a better understanding of the quality of the radar. Largest quality improvements in the radar data are obtained by ground clutter removal. The influence of VPR correction and advection depends on the precipitation system observed. Overall, the radar shows an underestimation as compared to the rain gauges, which becomes smaller after averaging at the scale of the medium-sized Ourthe catchment. Remaining differences between both devices can mainly be attributed to an improper choice of the Z-R relationship. Conceptual rainfall-runoff simulations show similar results using either catchment average radar or rain gauge data, although the largest discharge peak observed, is seriously underestimated when applying radar data. Overall, for hydrological applications corrected weather radar information in a hilly environment can be used up to 70 km during a winter half-year.

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

    Directory of Open Access Journals (Sweden)

    morteza akbari

    2017-03-01

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

  10. EVALUATION OF GLACIER MELT CONTRIBUTION TO RUNOFF IN THE NORTH CAUCASUS ALPINE CATCHMENTS USING ISOTOPIC METHODS AND ENERGY BALANCE MODELING

    Directory of Open Access Journals (Sweden)

    E. Rets

    2017-01-01

    Full Text Available Frequency and intensity of river floods rise observed in the North Caucasus during last decades is considered to be driven by recent climate change. In order to predict possible future trends in extreme hydrological events in the context of climate change, it is essential to estimate the contribution of different feed sources in complicated flow-forming processes in the alpine part of the North Caucasus. A study was carried out for the Djankuat River basin, the representative for the North Caucasus system. Simultaneous measurements of electrical conductivity, isotopic and ion balance equations, and energy balance modeling of ice and snow melt were used to evaluate the contribution of different sources and processes in the Djankuat River runoff regime formation. A forecast of possible future changes in the Djankuat glacier melting regime according to the predicted climate changes was done.

  11. Aquifer Recharge and Watershed Response to Climate Change in the Upper Umatilla River Subbasin Using the Precipitation Runoff Modeling System

    Science.gov (United States)

    Yazzie, K.

    2014-12-01

    Groundwater recharge in the Columbia River Basalt Group (CRBG) in the Umatilla River Basin, OR, is poorly understood. The long-term decline of groundwater storage in the basalt aquifers, present a serious environmental challenge for the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). This study will provide a groundwater estimate to help CTUIR better understand the hydrologic budget and inform water management decisions for present and future needs. The study site is in the upper Umatilla River Subbasin in Northeastern Oregon with an area that is 2,365 km2. The Precipitation Runoff Modeling System (PRMS) developed by the U.S. Geological Survey (USGS) is a distributed-parameter, physical-process watershed model that will be used to calculate groundwater recharge and simulate the watershed response to different climate and land use scenarios (Markstrom, 2008). The response of the hydrologic regime to climate change in the 2050s and 2080s will be determined using three downscaled Global Climate Models (GCMs), including the Earth System model of the Hadley Centre Global Environment Model, Version 2 (HadGEM2-ES), Model for Interdisciplinary Research on Climate (MIROC5), and the Geophysical Fluid Dynamics Laboratory - Earth System Model, (GFDL-ESM2M). The relationships between hydrologic processes at the surface, soil-zone, subsurface and groundwater reservoirs will be studied and defined in a water budget analysis to characterize the hydrologic regime in response to climate change.

  12. Comparison of modelled runoff with observed proglacial discharge across the western margin of the Greenland ice sheet

    Science.gov (United States)

    Moustafa, S.; Rennermalm, A.; van As, D.; Overeem, I.; Tedesco, M.; Mote, T. L.; Koenig, L.; Smith, L. C.; Hagedorn, B.; Sletten, R. S.; Mikkelsen, A. B.; Hasholt, B.; Hall, D. K.; Fettweis, X.; Pitcher, L. H.; Hubbard, A.

    2017-12-01

    Greenland ice sheet surface ablation now dominates its total mass loss contributions to sea-level rise. Despite the increasing importance of Greenland's sea-level contribution, a quantitative inter-comparison between modeled and measured melt, runoff and discharge across multiple drainage basins is conspicuously lacking. Here we investigate the accuracy of model discharge estimates from the Modèle Atmosphérique Régionale (MAR v3.5.2) regional climate model by comparison with in situ proglacial river discharge measurements at three West Greenland drainage basins - North River (Thule), Watson River (Kangerlussuaq), and Naujat Kuat River (Nuuk). At each target catchment, we: 1) determine optimal drainage basin delineations; 2) assess primary drivers of melt; 3) evaluate MAR at daily, 5-, 10- and 20-day time scales; and 4) identify potential sources for model-observation discrepancies. Our results reveal that MAR resolves daily discharge variability poorly in the Nuuk and Thule basins (r2 = 0.4-0.5), but does capture variability over 5-, 10-, and 20-day means (r2 > 0.7). Model agreement with river flow data, though, is reduced during periods of peak discharge, particularly for the exceptional melt and discharge events of July 2012. Daily discharge is best captured by MAR across the Watson River basin, whilst there is lower correspondence between modeled and observed discharge at the Thule and Naujat Kuat River basins. We link the main source of model error to an underestimation of cloud cover, overestimation of surface albedo, and apparent warm bias in near-surface air temperatures. For future inter-comparison, we recommend using observations from catchments that have a self-contained and well-defined drainage area and an accurate discharge record over variable years coincident with a reliable automatic weather station record. Our study highlights the importance of improving MAR modeled surface albedo, cloud cover representation, and delay functions to reduce model

  13. Climate downscaling over South America for 1971-2000: application in SMAP rainfall-runoff model for Grande River Basin

    Science.gov (United States)

    da Silva, Felipe das Neves Roque; Alves, José Luis Drummond; Cataldi, Marcio

    2018-03-01

    This paper aims to validate inflow simulations concerning the present-day climate at Água Vermelha Hydroelectric Plant (AVHP—located on the Grande River Basin) based on the Soil Moisture Accounting Procedure (SMAP) hydrological model. In order to provide rainfall data to the SMAP model, the RegCM regional climate model was also used working with boundary conditions from the MIROC model. Initially, present-day climate simulation performed by RegCM model was analyzed. It was found that, in terms of rainfall, the model was able to simulate the main patterns observed over South America. A bias correction technique was also used and it was essential to reduce mistakes related to rainfall simulation. Comparison between rainfall simulations from RegCM and MIROC showed improvements when the dynamical downscaling was performed. Then, SMAP, a rainfall-runoff hydrological model, was used to simulate inflows at Água Vermelha Hydroelectric Plant. After calibration with observed rainfall, SMAP simulations were evaluated in two different periods from the one used in calibration. During calibration, SMAP captures the inflow variability observed at AVHP. During validation periods, the hydrological model obtained better results and statistics with observed rainfall. However, in spite of some discrepancies, the use of simulated rainfall without bias correction captured the interannual flow variability. However, the use of bias removal in the simulated rainfall performed by RegCM brought significant improvements to the simulation of natural inflows performed by SMAP. Not only the curve of simulated inflow became more similar to the observed inflow, but also the statistics improved their values. Improvements were also noticed in the inflow simulation when the rainfall was provided by the regional climate model compared to the global model. In general, results obtained so far prove that there was an added value in rainfall when regional climate model was compared to global climate

  14. A Model Kelvin Electrostatic Generator.

    Science.gov (United States)

    Hill, M.; Jacobs, D. J.

    1997-01-01

    Describes how to construct a form of a Kelvin Electrostatics Generator from readily available components and provides an explanation of how it works. The device can generate 10-12 mm long sparks in the air. (DDR)

  15. Potential Release Site Sediment Concentrations Correlated to Storm Water Station Runoff through GIS Modeling

    International Nuclear Information System (INIS)

    McLean, C.T.

    2005-01-01

    DOE DWDCG. Tables were then created for each analyte that listed the PRSs average value by storm water station allowing a tabular view of the mapped data. The final table that was created listed the number of high erosion PRSs and regular PRSs over background values that were contained in each watershed. An overall relationship between the high erosion PRSs or the regular PRSs and the storm water stations was not identified through the methods used in this research. However, the Arc Hydro data models created for this analysis were used to track possible sources of contamination found through sampling at the storm water gaging stations. This geometric network tracing was used to identify possible relationships between the storm water stations and the PRSs. The methods outlined for the geometric network tracing could be used to find other relationships between the sites. A cursory statistical analysis was performed which could be expanded and applied to the data sets generated during this research to establish a broader relationship between the PRSs and storm water stations

  16. Rainfall-Runoff Parameters Uncertainity

    Science.gov (United States)

    Heidari, A.; Saghafian, B.; Maknoon, R.

    2003-04-01

    Karkheh river basin, located in southwest of Iran, drains an area of over 40000 km2 and is considered a flood active basin. A flood forecasting system is under development for the basin, which consists of a rainfall-runoff model, a river routing model, a reservior simulation model, and a real time data gathering and processing module. SCS, Clark synthetic unit hydrograph, and Modclark methods are the main subbasin rainfall-runoff transformation options included in the rainfall-runoff model. Infiltration schemes, such as exponentioal and SCS-CN methods, account for infiltration losses. Simulation of snow melt is based on degree day approach. River flood routing is performed by FLDWAV model based on one-dimensional full dynamic equation. Calibration and validation of the rainfall-runoff model on Karkheh subbasins are ongoing while the river routing model awaits cross section surveys.Real time hydrometeological data are collected by a telemetry network. The telemetry network is equipped with automatic sensors and INMARSAT-C comunication system. A geographic information system (GIS) stores and manages the spatial data while a database holds the hydroclimatological historical and updated time series. Rainfall runoff parameters uncertainty is analyzed by Monte Carlo and GLUE approaches.

  17. Influence factors and prediction of stormwater runoff of urban green space in Tianjin, China: laboratory experiment and quantitative theory model.

    Science.gov (United States)

    Yang, Xu; You, Xue-Yi; Ji, Min; Nima, Ciren

    2013-01-01

    The effects of limiting factors such as rainfall intensity, rainfall duration, grass type and vegetation coverage on the stormwater runoff of urban green space was investigated in Tianjin. The prediction equation of stormwater runoff was established by the quantitative theory with the lab experimental data of soil columns. It was validated by three field experiments and the relative errors between predicted and measured stormwater runoff are 1.41, 1.52 and 7.35%, respectively. The results implied that the prediction equation could be used to forecast the stormwater runoff of urban green space. The results of range and variance analysis indicated the sequence order of limiting factors is rainfall intensity > grass type > rainfall duration > vegetation coverage. The least runoff of green land in the present study is the combination of rainfall intensity 60.0 mm/h, duration 60.0 min, grass Festuca arundinacea and vegetation coverage 90.0%. When the intensity and duration of rainfall are 60.0 mm/h and 90.0 min, the predicted volumetric runoff coefficient is 0.23 with Festuca arundinacea of 90.0% vegetation coverage. The present approach indicated that green space is an effective method to reduce stormwater runoff and the conclusions are mainly applicable to Tianjin and the semi-arid areas with main summer precipitation and long-time interval rainfalls.

  18. Mathematical model for the formulation of runoff scenarios before possible variants of the climatic change

    International Nuclear Information System (INIS)

    Dominguez Calle, Efrain Antonio

    2001-01-01

    The application of mathematical modelling to evaluate the hydrological response of different river basins under multiple climate scenarios has become a wide spread tool. However, most of the existing models demand high volumes of data and high data quality. Usually, in Latin America not only the amount of data is scarce, but also the quality of it is very poor, so it is difficult to implement mathematical models with good validation results. Additionally, those models have to be applied over big geographical regions making the hydrological modelling process an almost impossible task. All these factors are pointing to the necessity to develop low data demanding models with few data quality requirements. In this light, this paper shows an attempt to develop a hydrological model under these restrictions. The results shown are concerned with the validation assessment of a study case in Colombia over an extensive region for the Catatumbo watershed. Finally, the improvements currently under implementation are shown

  19. Modeling and generating input processes

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, M.E.

    1987-01-01

    This tutorial paper provides information relevant to the selection and generation of stochastic inputs to simulation studies. The primary area considered is multivariate but much of the philosophy at least is relevant to univariate inputs as well. 14 refs.

  20. A method to employ the spatial organization of catchments into semi-distributed rainfall-runoff models

    Science.gov (United States)

    Oppel, Henning; Schumann, Andreas

    2017-08-01

    A distributed or semi-distributed deterministic hydrological model should consider the hydrologically most relevant catchment characteristics. These are heterogeneously distributed within a watershed but often interrelated and subject to a certain spatial organization which results in archetypes of combined characteristics. In order to reproduce the natural rainfall-runoff response the reduction of variance of catchment properties as well as the incorporation of the spatial organization of the catchment are desirable. In this study the width-function approach is utilized as a basic characteristic to analyse the succession of catchment characteristics. By applying this technique we were able to assess the context of catchment properties like soil or topology along the streamflow length and the network geomorphology, giving indications of the spatial organization of a catchment. Moreover, this information and this technique have been implemented in an algorithm for automated sub-basin ascertainment, which included the definition of zones within the newly defined sub-basins. The objective was to provide sub-basins that were less heterogeneous than common separation schemes. The algorithm was applied to two parameters characterizing the topology and soil of four mid-European watersheds. Resulting partitions indicated a wide range of applicability for the method and the algorithm. Additionally, the intersection of derived zones for different catchment characteristics could give insights into sub-basin similarities. Finally, a HBV96 case study demonstrated the potential benefits of modelling with the new subdivision technique.

  1. A method to employ the spatial organization of catchments into semi-distributed rainfall–runoff models

    Directory of Open Access Journals (Sweden)

    H. Oppel

    2017-08-01

    Full Text Available A distributed or semi-distributed deterministic hydrological model should consider the hydrologically most relevant catchment characteristics. These are heterogeneously distributed within a watershed but often interrelated and subject to a certain spatial organization which results in archetypes of combined characteristics. In order to reproduce the natural rainfall–runoff response the reduction of variance of catchment properties as well as the incorporation of the spatial organization of the catchment are desirable. In this study the width-function approach is utilized as a basic characteristic to analyse the succession of catchment characteristics. By applying this technique we were able to assess the context of catchment properties like soil or topology along the streamflow length and the network geomorphology, giving indications of the spatial organization of a catchment. Moreover, this information and this technique have been implemented in an algorithm for automated sub-basin ascertainment, which included the definition of zones within the newly defined sub-basins. The objective was to provide sub-basins that were less heterogeneous than common separation schemes. The algorithm was applied to two parameters characterizing the topology and soil of four mid-European watersheds. Resulting partitions indicated a wide range of applicability for the method and the algorithm. Additionally, the intersection of derived zones for different catchment characteristics could give insights into sub-basin similarities. Finally, a HBV96 case study demonstrated the potential benefits of modelling with the new subdivision technique.

  2. Watershed characterization for precipitation-runoff modeling system, north fork, American River and east fork, Carson River watersheds, California

    Science.gov (United States)

    Smith, J. LaRue; Reece, Brian D.

    1995-01-01

    As part of its Global Change Hydrology Program, the U.S. Geological Survey (USGS) is investigating the potential effects of climate change on the water resources of several river basins in the United States. The American River Basin in California represents the windward slope of the north-central Sierra Nevada, and the California part of the Carson River Basin, most of which is in Nevada, represents the leeward slope. Parts of the American River and Carson River Basins—the North Fork American River and East Fork Carson River watersheds, both in California—were studied to determine the sensitivity of water resources to potential climate change. The water resources of both basins are derived primarily from snowmelt. A geographic information system (GIS) data base has been created to facilitate paired-basin analysis. The GIS data base incorporates (1) land-surface data, which include elevation, land use and land cover, soil type, and geology; (2) hydrologic data, such as stream networks and streamflow-gaging stations; and (3) climatic data, such as snow-course, snow-telemetry, radiosonde, and meteorological data. Precipitation-runoff models were developed and calibrated for the North Fork watershed within the American River Basin and for the East Fork watershed within the Carson River Basin. (These watersheds were selected to represent the climatic and physiographic variability of the two larger basins.) Synthesized climate scenarios then were used in the model to predict potential effects of climate change.

  3. Modeling and Management of Increased Urban Stormwater Runoff Using InfoSWMM Sustain in the Berkeley Neighborhood of Denver, Colorado

    Science.gov (United States)

    Panos, C.; Hogue, T. S.; McCray, J. E.

    2016-12-01

    Few urban studies have evaluated the hydrologic impacts of redevelopment - for example, a rapid conversion from single to multi-family homes - known as infill, or re-urbanization. Redevelopment provides unique stormwater challenges as private property owners in many cities are not mandated to undertake stormwater retrofits leading to an overall increase in stormwater quantity and decrease in quality. This research utilizes a version of the EPA's Storm Water Management Model (SWMM), InfoSWMM Sustain, to model and analyze the impacts of impervious cover change due to redevelopment on stormwater quantity and quality in Denver, Colorado, with a focus on the Berkeley Neighborhood, where the percent imperviousness is expected to increase significantly from a current value of 53% by 2025. We utilize flow data from multiple pressure transducers installed directly within the storm sewer network as well as water quality data from storm and low flow sampling to initially calibrate InfoSWMM Sustain using September 2015 through September 2016 storm data. Model scenarios include current land cover conditions as well as future imperviousness predictions from redevelopment. The Urban Drainage and Flood Control District's Colorado Urban Hydrograph Procedure (CUHP) model is also implemented and used for calibration and comparison to the InfoSWMM stormwater model. Model simulations predicting an average annual stormwater runoff for the basin will be used to inform stormwater capture for the Berkeley Neighborhood on the downstream Willis Case Golf Course, where treatment trains are being designed to provide irrigation water (a 250 ac-ft per year demand) and improved water quality for discharge to the nearby receiving waters of Clear Creek. Ultimately, study results will better inform regional stormwater capture requirements when transitioning from single to multi-family units by providing a quantitative basis for treatment and regulation priorities.

  4. Semi-Supervised Generation with Cluster-aware Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Fraccaro, Marco; Winther, Ole

    2017-01-01

    Deep generative models trained with large amounts of unlabelled data have proven to be powerful within the domain of unsupervised learning. Many real life data sets contain a small amount of labelled data points, that are typically disregarded when training generative models. We propose the Cluster...... a log-likelihood of −79.38 nats on permutation invariant MNIST, while also achieving competitive semi-supervised classification accuracies. The model can also be trained fully unsupervised, and still improve the log-likelihood performance with respect to related methods....

  5. Soils - Potential Runoff

    Data.gov (United States)

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

  6. Uncertainty analysis in rainfall-runoff modelling : Application of machine learning techniques

    NARCIS (Netherlands)

    Shrestha, D.l.

    2009-01-01

    This thesis presents powerful machine learning (ML) techniques to build predictive models of uncertainty with application to hydrological models. Two different methods are developed and tested. First one focuses on parameter uncertainty analysis by emulating the results of Monte Carlo simulations of

  7. Uncertainty Analysis in Rainfall-Runoff Modelling: Application of Machine Learning Techniques

    NARCIS (Netherlands)

    Shrestha, D.L.

    2009-01-01

    This thesis presents powerful machine learning (ML) techniques to build predictive models of uncertainty with application to hydrological models. Two different methods are developed and tested. First one focuses on parameter uncertainty analysis by emulating the results of Monte Carlo simulations of

  8. How well do terrestrial biosphere models simulate coarse-scale runoff in the contiguous United States?

    Science.gov (United States)

    C.R. Schwalm; D.N. Huntzinger; R.B. Cook; Y. Wei; I.T. Baker; R.P. Neilson; B. Poulter; Peter Caldwell; G. Sun; H.Q. Tian; N. Zeng

    2015-01-01

    Significant changes in the water cycle are expected under current global environmental change. Robust assessment of present-day water cycle dynamics at continental to global scales is confounded by shortcomings in the observed record. Modeled assessments also yield conflicting results which are linked to differences in model structure and simulation protocol. Here we...

  9. Modeling the eutrophication of two mature planted stormwater ponds for runoff control

    DEFF Research Database (Denmark)

    Wium-Andersen, Tove; Nielsen, Asbjørn Haaning; Hvitved-Jacobsen, Thorkild

    2013-01-01

    A model, targeting eutrophication of stormwater detention ponds was developed and applied to sim-ulate pH, dissolved oxygen and the development of algae and plant biomass in two mature plantedwetponds for run off control. The model evaluated algal and plant biomass growth into three groupsnamely;...

  10. 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.

  11. A state-space representation of the GR4J rainfall-runoff model

    Science.gov (United States)

    Santos, Léonard; Thirel, Guillaume; Perrin, Charles

    2017-04-01

    In hydrology, the majority of conceptual models are available only in discrete form. This means that the formulations of the models are based on discrete equations instead of continuous ordinary differential equations (ODE) (see Clark and Kavetski, 2010). The time-step is often "hardcoded" in the model formulation. This can represent a problem in particular for creating a time step-variable model. Furthermore, the fluxes in the models are treated sequentially. For example, in the simple GR4J model, the precipitations (if any) are first added to the production store. Then, the updated level is used to compute the percolation from the store. The resulting level obtained at the end of the time step is different to the level which would be obtained if the two operations (i.e. addition of precipitation and percolation) were done simultaneously. Mathematically, this corresponds to an approximation of ODE solution which is called "operator splitting". This allows to solve an equation even if finding an exact solution is impossible but the error produced by this approximation is difficult to determine. For this reason, it is not easy to separate the numerical error of the resolution from the conceptual error. It could represent an important issue to better understand model behaviour and to identify possible improvements. The aim of this presentation is to detail a state-space representation of the simple GR4J model. The state-space representation aims to represent GR4J by an ODE system which provides the internal variables of the model at all times. We will present here the choices made to adapt GR4J to the state-space formulation and to numerically solve this system. Modifications of the model's equations were also made to adapt the model to lower time step in case it would be used for a time step-variable application. The results obtained with this state-space representation of GR4J were very similar to those of the original model in terms of performances and hydrographs

  12. Automated Measurement for Sensitivity Analysis of Runoff-Sediment Load at Varying Surface Gradients

    Directory of Open Access Journals (Sweden)

    Imanogor P.A.

    2015-07-01

    Full Text Available Direct measurement of surface runoff is often associated with errors and inaccuracies which results to unreliable hydrological data. An automatic Runoff-meter using tipping buckets arrangement calibrated to tip 0.14 liter of runoff water per tip with an accuracy of ± 0.001 litre was used to measure surface runoff from a steel bounded soil tray of dimension (1200 mm X 900 mm X 260 mm filled with sand loamy to the depth of 130 mm and inclined at angle (0 0 , 5 0 ,12 0 and 15 0 horizontal to the instrument. The effect of varying angles of inclination on runoff intensity, sediment loss rate and sediment loss is significant at 5 % confidence level, while surface runoff is not significant at 5 % confidence level. Total highest sediment loss of 458.2 g and 313.4 g were observed at angle 15 0 and 12 0 respectively. Total surface runoff of 361.5 mm and 445.8 mm were generated at inclined angle of 0 0 and 5 0 , while at angle 12 0 and 15 0 , 564.3 mm and 590.0 mm of surface runoff were generated. In addition, runoff intensity and sediment loss rate were highest at angle 15 0 , while the lowest values of 1.5mm/min and 5.43 g/min were obtained at angle of inclination 5 0 . The results showed that strong relationship existed among the hydrological variables as a result of subjecting the steel bounded soil tray to different angles of inclination. Such results would provide useful data for the running of physics-based deterministic model of surface runoff and erosion which will be useful for the design of hydrological structures, land use planning and management.

  13. Toward an operational tool to simulate green roof hydrological impact at the basin scale: a new version of the distributed rainfall-runoff model Multi-Hydro.

    Science.gov (United States)

    Versini, Pierre-Antoine; Gires, Auguste; Tchinguirinskaia, Ioulia; Schertzer, Daniel

    2016-10-01

    Currently widespread in new urban projects, green roofs have shown a positive impact on urban runoff at the building scale: decrease and slow-down of the peak discharge, and decrease of runoff volume. The present work aims to study their possible impact at the catchment scale, more compatible with stormwater management issues. For this purpose, a specific module dedicated to simulating the hydrological behaviour of a green roof has been developed in the distributed rainfall-runoff model (Multi-Hydro). It has been applied on a French urban catchment where most of the building roofs are flat and assumed to accept the implementation of a green roof. Catchment responses to several rainfall events covering a wide range of meteorological situations have been simulated. The simulation results show green roofs can significantly reduce runoff volume and the magnitude of peak discharge (up to 80%) depending on the rainfall event and initial saturation of the substrate. Additional tests have been made to assess the susceptibility of this response regarding both spatial distributions of green roofs and precipitation. It appears that the total area of greened roofs is more important than their locations. On the other hand, peak discharge reduction seems to be clearly dependent on spatial distribution of precipitation.

  14. Surface mass balance and runoff modeling using HIRHAM4 RCM at Kangerlussuaq (Søndre Strømfjord), West Greenland, 1950-2080

    DEFF Research Database (Denmark)

    Mernild, Sebastian H.; Liston, Glen E.; Hiemstra, Christopher A.

    2011-01-01

    Greenland's Kangerlussuaq drainage. Projected changes in the Greenland Ice Sheet (GrIS) surface mass balance (SMB) and runoff are relevant for potential hydropower production and prediction of ecosystem changes in sensitive Kangerlussuaq Fjord systems. Mean annual surface air temperatures and precipitation...... in the Kangerlussuaq area were simulated to increase by 3.4°C and 95 mm water equivalent (w.eq.), respectively, between 1950 and 2080. The local Kangerlussuaq warming was less than the average warming of 4.8°C simulated for the entire GrIS. The Kangerlussuaq SMB loss increased by an average of 0.3 km3 because of a 0.......4 km3 rise in precipitation, 0.1 km3 rise in evaporation and sublimation, and 0.6 km3 gain in runoff (1950-2080). By 2080, the spring runoff season begins approximately three weeks earlier. The average modeled SMB and runoff is approximately -0.1 and 1.2 km3 yr-1, respectively, indicating that ~10...

  15. 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.

  16. Evaluation of remote-sensing-based rainfall products through predictive capability in hydrological runoff modelling

    DEFF Research Database (Denmark)

    Stisen, Simon; Sandholt, Inge

    2010-01-01

    were similar. The results showed that the Climate Prediction Center/Famine Early Warning System (CPC-FEWS) and cold cloud duration (CCD) products, which are partly based on rain gauge data and produced specifically for the African continent, performed better in the modelling context than the global......The emergence of regional and global satellite-based rainfall products with high spatial and temporal resolution has opened up new large-scale hydrological applications in data-sparse or ungauged catchments. Particularly, distributed hydrological models can benefit from the good spatial coverage...

  17. Assessing potential effects of highway runoff on receiving-water quality at selected sites in Oregon with the Stochastic Empirical Loading and Dilution Model (SELDM)

    Science.gov (United States)

    Risley, John C.; Granato, Gregory E.

    2014-01-01

    In 2012, the U.S. Geological Survey and the Oregon Department of Transportation began a cooperative study to demonstrate use of the Stochastic Empirical Loading and Dilution Model (SELDM) for runoff-quality analyses in Oregon. SELDM can be used to estimate stormflows, constituent concentrations, and loads from the area upstream of a stormflow discharge site, from the site of interest and in the receiving waters downstream of the discharge. SELDM also can be used to assess the potential effectiveness of best management practices (BMP) for mitigating potential effects of runoff in receiving waters. Nominally, SELDM is a highway-runoff model, but it is well suited for analysis of runoff from other land uses as well. This report provides case studies and examples to demonstrate stochastic-runoff modeling concepts and to demonstrate application of the model. Basin characteristics from six Oregon highway study sites were used to demonstrate various applications of the model. The highway catchment and upstream basin drainage areas of these study sites ranged from 3.85 to 11.83 acres and from 0.16 to 6.56 square miles, respectively. The upstream basins of two sites are urbanized, and the remaining four sites are less than 5 percent impervious. SELDM facilitates analysis by providing precipitation, pre-storm streamflow, and other variables by region or from hydrologically similar sites. In Oregon, there can be large variations in precipitation and streamflow among nearby sites. Therefore, spatially interpolated geographic information system data layers containing storm-event precipitation and pre-storm streamflow statistics specific to Oregon were created for the study using Kriging techniques. Concentrations and loads of cadmium, chloride, chromium, copper, iron, lead, nickel, phosphorus, and zinc were simulated at the six Oregon highway study sites by using statistics from sites in other areas of the country. Water‑quality datasets measured at hydrologically similar

  18. Application of a Geographic Information System to Rainfall-Runoff Modeling

    Science.gov (United States)

    1991-02-01

    integrating the continuity of mass equation over the whole basin. 23 Seader , 1974 (32). A model called "DYIAH Ila is used to proj ect land use patterns for the...Data, Eastern Mendocino County, -California. USDA, Soil Conservation Service, Ukiah, California. 94 32. Seader , D. and S. Grava, 1971. "A Demonstration

  19. Parameter Estimation in Rainfall-Runoff Modelling Using Distributed Versions of Particle Swarm Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Michala Jakubcová

    2015-01-01

    Full Text Available The presented paper provides the analysis of selected versions of the particle swarm optimization (PSO algorithm. The tested versions of the PSO were combined with the shuffling mechanism, which splits the model population into complexes and performs distributed PSO optimization. One of them is a new proposed PSO modification, APartW, which enhances the global exploration and local exploitation in the parametric space during the optimization process through the new updating mechanism applied on the PSO inertia weight. The performances of four selected PSO methods were tested on 11 benchmark optimization problems, which were prepared for the special session on single-objective real-parameter optimization CEC 2005. The results confirm that the tested new APartW PSO variant is comparable with other existing distributed PSO versions, AdaptW and LinTimeVarW. The distributed PSO versions were developed for finding the solution of inverse problems related to the estimation of parameters of hydrological model Bilan. The results of the case study, made on the selected set of 30 catchments obtained from MOPEX database, show that tested distributed PSO versions provide suitable estimates of Bilan model parameters and thus can be used for solving related inverse problems during the calibration process of studied water balance hydrological model.

  20. Rainfall-runoff modeling at Jinsha River basin by integrated neural network with discrete wavelet transform

    Science.gov (United States)

    Tayyab, Muhammad; Zhou, Jianzhong; Dong, Xiaohua; Ahmad, Ijaz; Sun, Na

    2017-09-01

    Artificial neural network (ANN) models combined with time series decomposition are widely employed to calculate the river flows; however, the influence of the application of diverse decomposing approaches on assessing correctness is inadequately compared and examined. This study investigates the certainty of monthly streamflow by applying ANNs including feed forward back propagation neural network and radial basis function neural network (RBFNN) models integrated with discrete wavelet transform (DWT), at Jinsha River basin in the upper reaches of Yangtze River of China. The effect of the noise factor of the decomposed time series on the prediction correctness has also been argued in this paper. Data have been analyzed by comparing the simulation outputs of the models with the correlation coefficient (R) root mean square errors, mean absolute errors, mean absolute percentage error and Nash-Sutcliffe Efficiency. Results show that time series decomposition technique DWT contributes in improving the accuracy of streamflow prediction, as compared to single ANN's. The detailed comparative analysis showed that the RBFNN integrated with DWT has better forecasting capabilities as compared to other developed models. Moreover, for high-precision streamflow prediction, the high-frequency section of the original time series is very crucial, which is understandable in flood season.

  1. Modeling and analysis with induction generators

    CERN Document Server

    Simões, M Godoy

    2014-01-01

    ForewordPrefaceAcknowledgmentsAuthorsPrinciples of Alternative Sources of Energy and Electric GenerationScope of This ChapterLegal DefinitionsPrinciples of Electrical ConversionBasic Definitions of Electrical PowerCharacteristics of Primary SourcesCharacteristics of Remote Industrial, Commercial, and Residential Sites and Rural EnergySelection of the Electric GeneratorInterfacing Primary Source, Generator, and LoadExample of a Simple Integrated Generating and Energy-Storing SystemSolved ProblemsSuggested ProblemsReferencesSteady-State Model of Induction GeneratorsScope of This ChapterInterconnection and Disconnection of the Electric Distribution NetworkRobustness of Induction GeneratorsClassical Steady-State Representation of the Asynchronous MachineGenerated PowerInduced TorqueRepresentation of Induction Generator LossesMeasurement of Induction Generator ParametersBlocked Rotor Test (s = 1)No-Load Test (s = 0)Features of Induction Machines Working as Generators Interconnected to the Distribution NetworkHigh-...

  2. Daily Streamflow Predictions in an Ungauged Watershed in Northern California Using the Precipitation-Runoff Modeling System (PRMS): Calibration Challenges when nearby Gauged Watersheds are Hydrologically Dissimilar

    Science.gov (United States)

    Dhakal, A. S.; Adera, S.

    2017-12-01

    Accurate daily streamflow prediction in ungauged watersheds with sparse information is challenging. The ability of a hydrologic model calibrated using nearby gauged watersheds to predict streamflow accurately depends on hydrologic similarities between the gauged and ungauged watersheds. This study examines daily streamflow predictions using the Precipitation-Runoff Modeling System (PRMS) for the largely ungauged San Antonio Creek watershed, a 96 km2 sub-watershed of the Alameda Creek watershed in Northern California. The process-based PRMS model is being used to improve the accuracy of recent San Antonio Creek streamflow predictions generated by two empirical methods. Although San Antonio Creek watershed is largely ungauged, daily streamflow data exists for hydrologic years (HY) 1913 - 1930. PRMS was calibrated for HY 1913 - 1930 using streamflow data, modern-day land use and PRISM precipitation distribution, and gauged precipitation and temperature data from a nearby watershed. The PRMS model was then used to generate daily streamflows for HY 1996-2013, during which the watershed was ungauged, and hydrologic responses were compared to two nearby gauged sub-watersheds of Alameda Creek. Finally, the PRMS-predicted daily flows between HY 1996-2013 were compared to the two empirically-predicted streamflow time series: (1) the reservoir mass balance method and (2) correlation of historical streamflows from 80 - 100 years ago between San Antonio Creek and a nearby sub-watershed located in Alameda Creek. While the mass balance approach using reservoir storage and transfers is helpful for estimating inflows to the reservoir, large discrepancies in daily streamflow estimation can arise. Similarly, correlation-based predicted daily flows which rely on a relationship from flows collected 80-100 years ago may not represent current watershed hydrologic conditions. This study aims to develop a method of streamflow prediction in the San Antonio Creek watershed by examining PRMS

  3. Influence of different forest management practices and vegetation cover on runoff generation and sediment flux in the Coastal Range of Southern Chile

    Science.gov (United States)

    Mohr, Christian; Bronstert, Axel; Huber, Anton; Iroumé, Andrés.

    2010-05-01

    Favorable climatic and hydrological conditions make Chile to one of the leading timber and cellulose exporting nations with one of the biggest growing rates worldwide. The intensification of this sector comes along with large-scale land use changes affecting the soil's water conservation function of the geoecosystem. This research focuses on the influence of different forest management practices and vegetation cover on the runoff-generation and the sediment transport in Pinus radiata D.Don planted micro-catchments in the coastal range of southern Chile. One catchment is kept as control without silvicultural intervention during the whole study (catchment Nr. 1) and another was thinned selectively in the rainy season 2009 (catchment Nr. 2). Two catchments are harvested by clear-cuts, whereby one clear-cut already took place in June-Aug. 2009 during the rainy season (catchment Nr. 3) and the other is planned for the dry season in February 2010 (catchment Nr. 4). One catchment - formerly planted with Pinus radiata - was already clear cut in 2007 (catchment Nr. 5). For long-term research, the catchments are equipped with V-notched weirs, sediment sampling devices, rainfall redistribution test-plots and TDR-clusters. Single events of stronger precipitation and runoff are sampled and a self-designed rainfall-simulator is used to gain additional information of the infiltration, overland flow and sediment transport processes. Annual interception loss is approx. 20 % of the yearly avaraged precipitation of 1300mm. During the calibration period, all catchments show high similarities in discharge and a dominance of subsurface flow. In all catchments, diel cycles of different amplitude within the streamflow were registered. By the beginning of the rainy season in May, the soils in all catchments were saturated completely up to depth of 250cm. Only catchment 5 showed higher and irregular contents of soil water due to missing vegetation cover and recent morphodynamics. To the end

  4. Modelling the effect of fire frequency on runoff and erosion in north-central Portugal using the revised Morgan-Morgan-Finney

    Science.gov (United States)

    Hosseini, Mohammadreza; Nunes, João Pedro; González Pelayo, Oscar; Keizer, Jan Jacob; Ritsema, Coen; Geissen, Violette

    2017-04-01

    Models can be valuable for foreseeing the hydrological effects of fires and to plan and execute post-fire management alternatives. In this study, the revised Morgan-Morgan-Finney (MMF) model was utilized to simulate runoff and soil erosion in recently burned maritime pine plantations with different fire regimes, in a wet Mediterranean area of north-central Portugal. The MMF model was adjusted for burned zones in order to accommodate seasonal patterns in runoff and soil erosion, attributed to changes in soil water repellency and vegetation recovery. The model was then assessed by applying it for a sum of 18 experimental micro-plots (0.25 m2) at 9 1x-burnt and 9 4x-burnt slopes, using both literature-based and calibrated parameters, with the collected data used to assess the robustness of each parameterization. The estimate of erosion was more exact than that of runoff, with a general Nash-Sutcliffe efficiency of 0.54. Slope angle and the soil's effective hydrological depth (which relies on upon vegetation and additionally crop cover) were found to be the primary parameters enhancing model results, and different hydrological depths were expected to separate between the two differentiating fire regimes. This relative analysis demonstrated that most existing benchmark parameters can be utilized to apply MMF in burnt pine regions with moderate severity to support post-fire management; however it also showed that further endeavours ought to concentrate on mapping soil depth and vegetation cover to enhance these simulations.

  5. Application and Evaluation of a Snowmelt Runoff Model in the Tamor River Basin, Eastern Himalaya Using a Markov Chain Monte Carlo (MCMC) Data Assimilation Approach

    Science.gov (United States)

    Panday, Prajjwal K.; Williams, Christopher A.; Frey, Karen E.; Brown, Molly E.

    2013-01-01

    Previous studies have drawn attention to substantial hydrological changes taking place in mountainous watersheds where hydrology is dominated by cryospheric processes. Modelling is an important tool for understanding these changes but is particularly challenging in mountainous terrain owing to scarcity of ground observations and uncertainty of model parameters across space and time. This study utilizes a Markov Chain Monte Carlo data assimilation approach to examine and evaluate the performance of a conceptual, degree-day snowmelt runoff model applied in the Tamor River basin in the eastern Nepalese Himalaya. The snowmelt runoff model is calibrated using daily streamflow from 2002 to 2006 with fairly high accuracy (average Nash-Sutcliffe metric approx. 0.84, annual volume bias <3%). The Markov Chain Monte Carlo approach constrains the parameters to which the model is most sensitive (e.g. lapse rate and recession coefficient) and maximizes model fit and performance. Model simulated streamflow using an interpolated precipitation data set decreases the fractional contribution from rainfall compared with simulations using observed station precipitation. The average snowmelt contribution to total runoff in the Tamor River basin for the 2002-2006 period is estimated to be 29.7+/-2.9% (which includes 4.2+/-0.9% from snowfall that promptly melts), whereas 70.3+/-2.6% is attributed to contributions from rainfall. On average, the elevation zone in the 4000-5500m range contributes the most to basin runoff, averaging 56.9+/-3.6% of all snowmelt input and 28.9+/-1.1% of all rainfall input to runoff. Model simulated streamflow using an interpolated precipitation data set decreases the fractional contribution from rainfall versus snowmelt compared with simulations using observed station precipitation. Model experiments indicate that the hydrograph itself does not constrain estimates of snowmelt versus rainfall contributions to total outflow but that this derives from the degree

  6. Using Historical Precipitation, Temperature, and Runoff Observations to Evaluate Evaporation Formulations in Land Surface Models

    Science.gov (United States)

    Koster, Randal D.; Mahanama, P. P.

    2012-01-01

    Key to translating soil moisture memory into subseasonal precipitation and air temperature forecast skill is a realistic treatment of evaporation in the forecast system used - in particular, a realistic treatment of how evaporation responds to variations in soil moisture. The inherent soil moisture-evaporation relationships used in today's land surface models (LSMs), however, arguably reflect little more than guesswork given the lack of evaporation and soil moisture data at the spatial scales represented by regional and global models. Here we present a new approach for evaluating this critical aspect of LSMs. Seasonally averaged precipitation is used as a proxy for seasonally-averaged soil moisture, and seasonally-averaged air temperature is used as a proxy for seasonally-averaged evaporation (e.g., more evaporative cooling leads to cooler temperatures) the relationship between historical precipitation and temperature measurements accordingly mimics in certain important ways nature's relationship between soil moisture and evaporation. Additional information on the relationship is gleaned from joint analysis of precipitation and streamflow measurements. An experimental framework that utilizes these ideas to guide the development of an improved soil moisture-evaporation relationship is described and demonstrated.

  7. Urbanisation impacts on storm runoff along a rural-urban gradient

    Science.gov (United States)

    Miller, James David; Hess, Tim

    2017-09-01

    Urbanisation alters the hydrological response of catchments to storm events and spatial measures of urban extent and imperviousness are routinely used in hydrological modelling and attribution of runoff response to land use changes. This study evaluates whether a measure of catchment urban extent can account for differences in runoff generation from storm events along an rural-urban gradient. We employed a high-resolution monitoring network across 8 catchments in the south of the UK - ranging from predominantly rural to heavily urbanised - over a four year period, and from this selected 336 storm events. Hydrological response was compared using volume- and scaled time-based hydrograph metrics within a statistical framework that considered the effect of antecedent soil moisture. Clear differences were found between rural and urban catchments, however above a certain threshold of urban extent runoff volume was relatively unaffected by changes and runoff response times were highly variable between catchments due to additional hydraulic controls. Results indicate a spatial measure of urbanisation can generally explain differences in the hydrological response between rural and urban catchments but is insufficient to explain differences between urban catchments along an urban gradient. Antecedent soil moisture alters the volume and timing of runoff generated in catchments with large rural areas, but was not found to affect the runoff response where developed areas are much greater. The results of this study suggest some generalised relationships between urbanisation and storm runoff are not represented in observed storm events and point to limitations in using a simplified representations of the urban environment for attribution of storm runoff in small urban catchments. The study points to the need for enhanced hydrologically relevant catchment descriptors specific to small urban catchments and more focused research on the role of urban soils and soil moisture in storm

  8. Next Generation Transport Phenomenology Model

    Science.gov (United States)

    Strickland, Douglas J.; Knight, Harold; Evans, J. Scott

    2004-01-01

    This report describes the progress made in Quarter 3 of Contract Year 3 on the development of Aeronomy Phenomenology Modeling Tool (APMT), an open-source, component-based, client-server architecture for distributed modeling, analysis, and simulation activities focused on electron and photon transport for general atmospheres. In the past quarter, column emission rate computations were implemented in Java, preexisting Fortran programs for computing synthetic spectra were embedded into APMT through Java wrappers, and work began on a web-based user interface for setting input parameters and running the photoelectron and auroral electron transport models.

  9. Integrated simulation of snow and glacier melt runoff in a distributed biosphere hydrological modeling framework at Upper Indus Basin, Karakoram region

    Science.gov (United States)

    Shrestha, M.; Koike, T.; Xue, Y.; Wang, L.; Hirabayashi, Y.

    2014-12-01

    High mountain river basins in Hindukush Karakoram and Himalaya (HKH) regions are considered as 'water towers' of Asia with abundant source of fresh water as snow and glaciers. Upper Indus basin is one of the mega scale river basin in HKH region where snow and glaciermelt runoff is the major contributor to the annual runoff. The hostile climate, remote and extreme rough topography imposes many restraints regarding hydro-meteorological and glaciological observations, leading towards limited understanding of hydrological processes of river basins in this region. It is vital to integrate snow and glacier melt processes in a distributed biosphere hydrological framework to estimate the snow and glacier melt runoff and to quantify the river flow composition (snowmelt, glacier melt and rainfall contribution). An integrated system of distributed biosphere hydrological modeling framework with multilayer energy balance based snow and glaciermelt runoff schemes (WEB-DHM-S model) was implemented at Upper Indus basin (207300 km2) with a spatial resolution of 1 km and temporal resolution of an hour. Model input were meteorological forcing from Global Land Data Assimilation System (GLDAS), APHRODITE precipitation and de-trended gridded air temperature from observations. Simulations were carried out for two hydrological years (2002-2003). Discharge simulation results at multiple gauges showed good agreement with the observed one having Nash efficiency at 0.86. The spatial distribution of snow cover is simulated well as compared to the Moderate Resolution Imaging Spectroradiometer (MODIS) derived eight-day maximum snow-cover extent data (MOD10A2). Model accuracy, overestimation error and underestimation error in snow cover simulation were obtained at 78%, 7% and 15% respectively. Uncertainty in precipitation was the main reason for the biases in seasonal variation of snow pixel errors. The model demonstrated its sound capability in comprehensive simulation of discharge with its flow

  10. Comparison of SWAT and GeoWEPP model in predicting the impact of stone bunds on runoff and erosion processes in the Northern Ethiopian Highlands

    Science.gov (United States)

    Demelash, Nigus; Flagler, Jared; Renschler, Chris; Strohmeier, Stefan; Holzmann, Hubert; Feras, Ziadat; Addis, Hailu; Zucca, Claudio; Bayu, Wondimu; Klik, Andreas

    2017-04-01

    Soil degradation is a major issue in the Ethiopian highlands which are most suitable for agriculture and, therefore, support a major part of human population and livestock. Heavy rainstorms during the rainy season in summer create soil erosion and runoff processes which affect soil fertility and food security. In the last years programs for soil conservation and afforestation were initiated by the Ethiopian government to reduce erosion risk, retain water in the landscape and improve crop yields. The study was done in two adjacent watersheds in the Northwestern highlands of Ethiopia. One of the watersheds is developed by soil and water conservation structures (stone bunds) in 2011 and the other one is without soil and water conservation structures. Spatial distribution of soil textures and other soil properties were determined in the field and in the laboratory and a soil map was derived. A land use map was evaluated based on satellite images and ground truth data. A Digital Elevation Model of the watershed was developed based on conventional terrestrial surveying using a total station. At the outlet of the watersheds weirs with cameras were installed to measure surface runoff. During each event runoff samples were collected and sediment concentration was analyzed. The objective of this study is 1) to assess the impact of stone bunds on runoff and erosion processes by using simulation models, and 2) to compare the performance of two soil erosion models in predicting the measurements. The selected erosion models were the Soil and Water Assessment Tool (SWAT) and the Geospatial Interface to the Water Erosion Prediction Project (GeoWEPP). The simulation models were calibrated/verified for the 2011-2013 periods and validated with 2014-2015 data. Results of this comparison will be presented.

  11. Modelling with stakeholders - Next generation

    Science.gov (United States)

    Voinov, Alexey; Kolagani, Nagesh; McCall, Michael K; Glynn, Pierre D.; Kragt, Marit E; Ostermann, Frank O; Pierce, Suzanne A; Ramu, Palaniappan

    2016-01-01

    This paper updates and builds on ‘Modelling with Stakeholders’ Voinov and Bousquet, 2010 which demonstrated the importance of, and demand for, stakeholder participation in resource and environmental modelling. This position paper returns to the concepts of that publication and reviews the progress made since 2010. A new development is the wide introduction and acceptance of social media and web applications, which dramatically changes the context and scale of stakeholder interactions and participation. Technology advances make it easier to incorporate information in interactive formats via visualization and games to augment participatory experiences. Citizens as stakeholders are increasingly demanding to be engaged in planning decisions that affect them and their communities, at scales from local to global. How people interact with and access models and data is rapidly evolving. In turn, this requires changes in how models are built, packaged, and disseminated: citizens are less in awe of experts and external authorities, and they are increasingly aware of their own capabilities to provide inputs to planning processes, including models. The continued acceleration of environmental degradation and natural resource depletion accompanies these societal changes, even as there is a growing acceptance of the need to transition to alternative, possibly very different, life styles. Substantive transitions cannot occur without significant changes in human behaviour and perceptions. The important and diverse roles that models can play in guiding human behaviour, and in disseminating and increasing societal knowledge, are a feature of stakeholder processes today.

  12. Generation of Java code from Alvis model

    Science.gov (United States)

    Matyasik, Piotr; Szpyrka, Marcin; Wypych, Michał

    2015-12-01

    Alvis is a formal language that combines graphical modelling of interconnections between system entities (called agents) and a high level programming language to describe behaviour of any individual agent. An Alvis model can be verified formally with model checking techniques applied to the model LTS graph that represents the model state space. This paper presents transformation of an Alvis model into executable Java code. Thus, the approach provides a method of automatic generation of a Java application from formally verified Alvis model.

  13. A balanced team generating model

    NARCIS (Netherlands)

    van de Water, Tara; van de Water, Henny; Bukman, Cock

    2007-01-01

    This paper introduces a general team balancing model. It first summarizes existing balancing methods. It is shown that for these methods it is difficult to meet all the conditions posed by Belbin on balanced teams. This mainly is caused by the complexity of the balancing problem. A mathematical

  14. First Results of using the Process-based Model PROMAB-GIS for Runoff a Bedload Transport Estimation in the Lainbach Torrent Catchment Area (Benediktbeuern, Germany)

    Science.gov (United States)

    Rinderer, M.; Jenewein, S.; Ploner, A.; Sönser, T.

    2003-04-01

    As growing damage potential makes society more and more vulnerable to natural hazards, the pressure on the official authorities responsible for the guarantee of public safety is increasing rapidly. Modern computer technology, e.g. Geographical Information Systems (GIS), can provide remarkable help in assessing the risks resulting from natural hazards. The modelling in PROMAB-GIS, which is an user friendly software based on ESRI ArcView for assessing runoff and bedload transport in torrent catchments, is strongly based on interdisciplinary process-orientated field investigations. This paper presents results of the application of PROMAB-GIS to estimate the runoff and bedload transport potential of the Lainbach catchment area which has repeatedly been affected by heavy rain storms triggering remarkable events. The operational steps needed to gain process orientated, reproducible results for assessing design events in watersheds are highlighted. A key issue in this context is the need for detailed field-investigation of the geo-, bio-, hydro-inventory of a catchment area. The second part of the paper presents the model results for design events. The data of the event which caused severe damage in June 1990 provides a perfect basis for the evaluation of the model. The results show the potential of PROMAB-GIS for assessing runoff and bedload transport in alpine torrent systems.

  15. Evaluation of the AnnAGNPS Model for Predicting Runoff and Nutrient Export in a Typical Small Watershed in the Hilly Region of Taihu Lake

    Directory of Open Access Journals (Sweden)

    Chuan Luo

    2015-09-01

    Full Text Available The application of hydrological and water quality models is an efficient approach to better understand the processes of environmental deterioration. This study evaluated the ability of the Annualized Agricultural Non-Point Source (AnnAGNPS model to predict runoff, total nitrogen (TN and total phosphorus (TP loading in a typical small watershed of a hilly region near Taihu Lake, China. Runoff was calibrated and validated at both an annual and monthly scale, and parameter sensitivity analysis was performed for TN and TP before the two water quality components were calibrated. The results showed that the model satisfactorily simulated runoff at annual and monthly scales, both during calibration and validation processes. Additionally, results of parameter sensitivity analysis showed that the parameters Fertilizer rate, Fertilizer organic, Canopy cover and Fertilizer inorganic were more sensitive to TN output. In terms of TP, the parameters Residue mass ratio, Fertilizer rate, Fertilizer inorganic and Canopy cover were the most sensitive. Based on these sensitive parameters, calibration was performed. TN loading produced satisfactory results for both the calibration and validation processes, whereas the performance of TP loading was slightly poor. The simulation results showed that AnnAGNPS has the potential to be used as a valuable tool for the planning and management of watersheds.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-06-01

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

  17. Digital relief generation from 3D models

    Science.gov (United States)

    Wang, Meili; Sun, Yu; Zhang, Hongming; Qian, Kun; Chang, Jian; He, Dongjian

    2016-09-01

    It is difficult to extend image-based relief generation to high-relief generation, as the images contain insufficient height information. To generate reliefs from three-dimensional (3D) models, it is necessary to extract the height fields from the model, but this can only generate bas-reliefs. To overcome this problem, an efficient method is proposed to generate bas-reliefs and high-reliefs directly from 3D meshes. To produce relief features that are visually appropriate, the 3D meshes are first scaled. 3D unsharp masking is used to enhance the visual features in the 3D mesh, and average smoothing and Laplacian smoothing are implemented to achieve better smoothing results. A nonlinear variable scaling scheme is then employed to generate the final bas-reliefs and high-reliefs. Using the proposed method, relief models can be generated from arbitrary viewing positions with different gestures and combinations of multiple 3D models. The generated relief models can be printed by 3D printers. The proposed method provides a means of generating both high-reliefs and bas-reliefs in an efficient and effective way under the appropriate scaling factors.

  18. Simulated Impact of Glacial Runoff on CO2 Uptake in the Gulf of Alaska

    Science.gov (United States)

    Pilcher, Darren J.; Siedlecki, Samantha A.; Hermann, Albert J.; Coyle, Kenneth O.; Mathis, Jeremy T.; Evans, Wiley

    2018-01-01

    The Gulf of Alaska (GOA) receives substantial summer freshwater runoff from glacial meltwater. The alkalinity of this runoff is highly dependent on the glacial source and can modify the coastal carbon cycle. We use a regional ocean biogeochemical model to simulate CO2 uptake in the GOA under different alkalinity-loading scenarios. The GOA is identified as a current net sink of carbon, though low-alkalinity tidewater glacial runoff suppresses summer coastal carbon uptake. Our model shows that increasing the alkalinity generates an increase in annual CO2 uptake of 1.9-2.7 TgC/yr. This transition is comparable to a projected change in glacial runoff composition (i.e., from tidewater to land-terminating) due to continued climate warming. Our results demonstrate an important local carbon-climate feedback that can significantly increase coastal carbon uptake via enhanced air-sea exchange, with potential implications to the coastal ecosystems in glaciated areas around the world.

  19. Computing LS factor by runoff paths on TIN

    Science.gov (United States)

    Kavka, Petr; Krasa, Josef; Bek, Stanislav

    2013-04-01

    The article shows results of topographic factor (the LS factor in USLE) derivation enhancement focused on detailed Airborne Laser Scanning (ALS) based DEMs. It describes a flow paths generation technique using triangulated irregular network (TIN) for terrain morphology description, which is not yet established in soil loss computations. This technique was compared with other procedures of flow direction and flow paths generation based on commonly used raster model (DEM). These overland flow characteristics together with therefrom derived flow accumulation are significant inputs for many scientific models. Particularly they are used in all USLE-based soil erosion models, from which USLE2D, RUSLE3D, Watem/Sedem or USPED can be named as the most acknowledged. Flow routing characteristics are also essential parameters in physically based hydrological and soil erosion models like HEC-HMS, Wepp, Erosion3D, LISEM, SMODERP, etc. Mentioned models are based on regular raster grids, where the identification of runoff direction is problematic. The most common method is Steepest descent (one directional flow), which corresponds well with the concentration of surface runoff into concentrated flow. The Steepest descent algorithm for the flow routing doesn't provide satisfying results, it often creates parallel and narrow flow lines while not respecting real morphological conditions. To overcome this problem, other methods (such as Flux Decomposition, Multiple flow, Deterministic Infinity algorithm etc.) separate the outflow into several components. This approach leads to unrealistic diffusion propagation of the runoff and makes it impossible to be used for simulation of dominant morphological features, such as artificial rills, hedges, sediment traps etc. The modern methods of mapping ground elevations, especially ALS, provide very detailed models even for large river basins, including morphological details. New algorithms for derivation a runoff direction have been developed as

  20. Hydrological control of large hurricane-induced lahars: evidence from rainfall-runoff modeling, seismic and video monitoring

    Science.gov (United States)

    Capra, Lucia; Coviello, Velio; Borselli, Lorenzo; Márquez-Ramírez, Víctor-Hugo; Arámbula-Mendoza, Raul

    2018-03-01

    The Volcán de Colima, one of the most active volcanoes in Mexico, is commonly affected by tropical rains related to hurricanes that form over the Pacific Ocean. In 2011, 2013 and 2015 hurricanes Jova, Manuel and Patricia, respectively, triggered tropical storms that deposited up to 400 mm of rain in 36 h, with maximum intensities of 50 mm h -1. The effects were devastating, with the formation of multiple lahars along La Lumbre and Montegrande ravines, which are the most active channels in sediment delivery on the south-southwest flank of the volcano. Deep erosion along the river channels and several marginal landslides were observed, and the arrival of block-rich flow fronts resulted in damages to bridges and paved roads in the distal reaches of the ravines. The temporal sequence of these flow events is reconstructed and analyzed using monitoring data (including video images, seismic records and rainfall data) with respect to the rainfall characteristics and the hydrologic response of the watersheds based on rainfall-runoff numerical simulation. For the studied events, lahars occurred 5-6 h after the onset of rainfall, lasted several hours and were characterized by several pulses with block-rich fronts and a maximum flow discharge of 900 m3 s -1. Rainfall-runoff simulations were performer using the SCS-curve number and the Green-Ampt infiltration models, providing a similar result in the detection of simulated maximum watershed peaks discharge. Results show different behavior for the arrival times of the first lahar pulses that correlate with the simulated catchment's peak discharge for La Lumbre ravine and with the peaks in rainfall intensity for Montegrande ravine. This different behavior is related to the area and shape of the two watersheds. Nevertheless, in all analyzed cases, the largest lahar pulse always corresponds with the last one and correlates with the simulated maximum peak discharge of these catchments. Data presented here show that flow pulses

  1. Comparison of ensemble post-processing approaches, based on empirical and dynamical error modelisation of rainfall-runoff model forecasts

    Science.gov (United States)

    Chardon, J.; Mathevet, T.; Le Lay, M.; Gailhard, J.

    2012-04-01

    dynamic and processes, i. e. sample heterogeneity. For a same streamflow range corresponds different processes such as rising limbs or recession, where uncertainties are different. The dynamical approach improves reliability, skills and sharpness of forecasts and globally reduces confidence intervals width. When compared in details, the dynamical approach allows a noticeable reduction of confidence intervals during recessions where uncertainty is relatively lower and a slight increase of confidence intervals during rising limbs or snowmelt where uncertainty is greater. The dynamic approach, validated by forecaster's experience that considered the empirical approach not discriminative enough, improved forecaster's confidence and communication of uncertainties. Montanari, A. and Brath, A., (2004). A stochastic approach for assessing the uncertainty of rainfall-runoff simulations. Water Resources Research, 40, W01106, doi:10.1029/2003WR002540. Schaefli, B., Balin Talamba, D. and Musy, A., (2007). Quantifying hydrological modeling errors through a mixture of normal distributions. Journal of Hydrology, 332, 303-315.

  2. Inferring runoff generation processes through high resolution spatial and temporal UV-Vis absorbance measurements in a mountainous headwater catchment in Southern Ecuador

    Science.gov (United States)

    Windhorst, David; Schob, Sarah; Zang, Carina; Crespo, Patricio; Breuer, Lutz

    2015-04-01

    The alpine grassland páramo - typically occurring in the headwater catchments of the Andes - plays an important role in flow regulation, hydropower generation and local water supply. However, hydrological and hydro-biogeochemical processes in the páramo and their potential reactions to climate and land use change are largely unknown. Therefore, we used a UV-Vis absorbance spectrometer to investigate fluxes of biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity and nitrate (NO3-N) in a small headwater catchment (91.31 km²) in the páramo in south Ecuador on a 5 min temporal and 100 m spatial resolution to gain first insights in its hydrological functioning. Spatial sampling was realized during three snapshot sampling campaigns along the 14.2 km long stream between October 2013 and January 2014, while temporal sampling took place at a permanent sampling site within the catchment between February and June 2014. To identify the runoff generation processes the spatial patterns have been associated with local site specific (e.g. fish ponds) and sub-catchment wide (e.g. land use) characteristics. Storm flow events within the time series allowed to further study temporal changes and rotational patterns of concentration-discharge relations (hysteresis). In total, 35 events were identified to be suitable for analyzing hysteresis effects of BOD, COD, and turbidity. Nitrate concentrations could be studied for 20 events. Regardless of the flow conditions nitrate leaching increased with a growing share of non-native pine forests or pastures in the study area. During low flow conditions, the high water holding capacity of the upstream páramo areas ensured a continuous supply of BOD to the stream. Pasture and pine forest sites, mostly occurring in the downstream section of the stream, contributed to BOD only during discharge events. Contradicting the expectations the trout farms along the lower part of the streams had a relatively closed nutrient cycle and

  3. Parametric study for horizontal steam generator modelling

    Energy Technology Data Exchange (ETDEWEB)

    Ovtcharova, I. [Energoproekt, Sofia (Bulgaria)

    1995-12-31

    In the presentation some of the calculated results of horizontal steam generator PGV - 440 modelling with RELAP5/Mod3 are described. Two nodalization schemes have been used with different components in the steam dome. A study of parameters variation on the steam generator work and calculated results is made in cases with separator and branch.

  4. Evaluating the differences in scale for snowpack modeling using the Precipitation Runoff Modeling System and iSnobal in the Boise River Basin, Idaho

    Science.gov (United States)

    Havens, S.; Marks, D. G.; Hedrick, A. R.; Kormos, P.; Rothwell, E.

    2016-12-01

    Operational water management has a desire to move away from statistical forecasting methods based on the relationships between snow measurements at a few locations to measured streamflow. As the climate changes, the historical relationships become less robust and cannot accurately capture extreme weather like rain-on-snow or a change in the rain-snow transition elevation, therefore many agencies have moved to more complex models. One example is the Precipitation Runoff Modeling System (PRMS), which models the entire hydrological cycle at the hydrologic response unit (HRU) scale. However, in the Western US most watersheds are snow-dominated so the coarse HRU's may not accurately capture the sub-HRU physical processes that determine snow accumulation and melt. On the other hand, snow models such as iSnobal, which explicitly calculate the energy and mass balance at a high resolution, are able to accurately reproduce the snowpack state. This project evaluates a calibrated PRMS model coupled with the uncalibrated iSnobal model run at 100-meter resolution over the Boise River Basin (7,000 km2) in Idaho, USA for a 15-year period between water year 2001 and 2016. This work is the first step towards coupling a higher resolution, physically based snow model to the hydrologic components of PRMS, which will provide water managers improved tools for routing snowmelt into streamflow.

  5. Simulation of Runoff and Reservoir Inflow for Use in a Flood-Analysis Model for the Delaware River, Pennsylvania, New Jersey, and New York, 2004-2006

    Science.gov (United States)

    Goode, Daniel J.; Koerkle, Edward H.; Hoffman, Scott A.; Regan, R. Steve; Hay, Lauren E.; Markstrom, Steven L.

    2010-01-01

    A model was developed to simulate inflow to reservoirs and watershed runoff to streams during three high-flow events between September 2004 and June 2006 for the main-stem subbasin of the Delaware River draining to Trenton, N.J. The model software is a modified version of the U.S. Geological Survey (USGS) Precipitation-Runoff Modeling System (PRMS), a modular, physically based, distributed-parameter modeling system developed to evaluate the impacts of various combinations of precipitation, climate, and land use on surface-water runoff and general basin hydrology. The PRMS model simulates time periods associated with main-stem flooding that occurred in September 2004, April 2005, and June 2006 and uses both daily and hourly time steps. Output from the PRMS model was formatted for use as inflows to a separately documented reservoir and riverrouting model, the HEC-ResSim model, developed by the U.S. Army Corps of Engineers Hydrologic Engineering Center to evaluate flooding. The models were integrated through a graphical user interface. The study area is the 6,780 square-mile watershed of the Delaware River in the states of Pennsylvania, New Jersey, and New York that drains to Trenton, N.J. A geospatial database was created for use with a geographic information system to assist model discretization, determine land-surface characterization, and estimate model parameters. The USGS National Elevation Dataset at 100-meter resolution, a Digital Elevation Model (DEM), was used for model discretization into streams and hydrologic response units. In addition, geospatial processing was used to estimate initial model parameters from the DEM and other data layers, including land use. The model discretization represents the study area using 869 hydrologic response units and 452 stream segments. The model climate data for point stations were obtained from multiple sources. These sources included daily data for 22 National Weather Service (NWS) Cooperative Climate Station network

  6. Generalized Reduced Order Model Generation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — M4 Engineering proposes to develop a generalized reduced order model generation method. This method will allow for creation of reduced order aeroservoelastic state...

  7. Generalized Reduced Order Model Generation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — M4 Engineering proposes to develop a generalized reduced order model generation method. This method will allow for creation of reduced order aeroservoelastic state...

  8. Approximate Inference and Deep Generative Models

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Advances in deep generative models are at the forefront of deep learning research because of the promise they offer for allowing data-efficient learning, and for model-based reinforcement learning. In this talk I'll review a few standard methods for approximate inference and introduce modern approximations which allow for efficient large-scale training of a wide variety of generative models. Finally, I'll demonstrate several important application of these models to density estimation, missing data imputation, data compression and planning.

  9. Pitch Gestures in Generative Modeling of Music

    DEFF Research Database (Denmark)

    Jensen, Kristoffer

    2011-01-01

    Generative models of music are in need of performance and gesture additions, i.e. inclusions of subtle temporal and dynamic alterations, and gestures so as to render the music musical. While much of the research regarding music generation is based on music theory, the work presented here is based...... on the temporal perception, which is divided into three parts, the immediate (subchunk), the short-term memory (chunk), and the superchunk. By review of the relevant temporal perception literature, the necessary performance elements to add in the metrical generative model, related to the chunk memory...

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

    Indian Academy of Sciences (India)

    rainfall–runoff study at a watershed near Houston, Texas with a fully distributed Vflo rainfall– runoff model. The hydrograph comparisons exhibited that the outflow using radar data input matched the observed streamflow in terms of volume and peak flow. The objective of this study is to simulate the rainfall–runoff processes ...

  11. Determination of characteristics maximal runoff mountain rivers in ...

    African Journals Online (AJOL)

    ... water) on the rivers of the Crimean Mountains were used materials of observations for long-term period (from the beginning of observations to 2010 inclusive) on 54 of streamflow station with using a the so-called «operator» model for maximum runoff formation. Keywords: maximum runoff; rain floods; hillslope runoff; karst ...

  12. Application of a Nested Modeling Approach Using the Precipitation Runoff Modeling System in the Apalachicola-Chattahoochee-Flint River Basin in the Southeastern USA

    Science.gov (United States)

    Lafontaine, J.; Hay, L.; Viger, R.; Markstrom, S. L.

    2010-12-01

    In order to help environmental resource managers assess potential effects of climate change on ecosystems, the Southeast Regional Assessment Project (SERAP) began in 2009. One component of the SERAP is development and calibration of a set of multi-resolution hydrologic models of the Apalachicola-Chattahoochee-Flint (ACF) River Basin. The ACF River Basin is home to multiple fish and wildlife species of conservation concern, is regionally important for water supply, and has been a recent focus of complementary environmental and climate-change research. Hydrologic models of varying spatial extents and resolutions are required to address varied local to regional water-resource management questions as required by the scope and limits of potential management actions. These models were developed using the U.S. Geological Survey (USGS) Precipitation Runoff Modeling System (PRMS). The coarse-resolution model for the ACF Basin has a contributing area of approximately 19,200 mi2 with the model outlet located at the USGS streamflow gage on the Apalachicola River near Sumatra, Florida. Six fine-resolution PRMS models ranging in size from 153 mi2 to 1,040 mi2 are nested within the coarse-scale model, and have been developed for the following basins: upper Chattahoochee, Chestatee, and Chipola Rivers, Ichawaynochaway, Potato, and Spring Creeks. All of the models simulate basin hydrology using a daily time-step, measured climate data, and basin characteristics such as land cover and topography. Measured streamflow data are used to calibrate and evaluate computed basin hydrology. Land cover projections will be used in conjunction with downscaled Global Climate Model results to project future hydrologic conditions for this set of models.

  13. Rainfall-runoff modelling and palaeoflood hydrology applied to reconstruct centennial scale records of flooding and aquifer recharge in ungauged ephemeral rivers

    Directory of Open Access Journals (Sweden)

    G. Benito

    2011-04-01

    Full Text Available In this study we propose a multi-source data approach for quantifying long-term flooding and aquifer recharge in ungauged ephemeral rivers. The methodology is applied to the Buffels River, at 9000 km2 the largest ephemeral river in Namaqualand (NW South Africa, a region with scarce stream flow records limiting research investigating hydrological response to global change. Daily discharge and annual flood series (1965–2006 were estimated from a distributed rainfall-runoff hydrological model (TETIS using rainfall gauge records located within the catchment. The model was calibrated and validated with data collected during a two year monitoring programme (2005–2006 at two stream flow stations, one each in the upper and lower reaches of the catchment. In addition to the modelled flow records, non-systematic flood data were reconstructed using both sedimentary and documentary evidence. The palaeoflood record identified at least 25 large floods during the last 700 yr; with the largest floods reaching a minimum discharge of 255 m3 s−1 (450 yr return period in the upper basin, and 510 m3 s−1 (100 yr return period in the lower catchment. Since AD 1925, the flood hydrology of the Buffels River has been characterised by a decrease in the magnitude and frequency of extreme floods, with palaeoflood discharges (period 1500–1921 five times greater than the largest modelled floods during the period 1965–2006. Large floods generated the highest hydrograph volumes, however their contribution to aquifer recharge is limited as this depends on other factors such as flood duration and storage capacity of the unsaturated zone prior to the flood. Floods having average return intervals of 5–10 yr (120–140 m3 s−1 and flowing for 12 days are able to fully saturate the Spektakel aquifer in the lower Buffels River basin. Alluvial aquifer storage capacity limiting potential recharge

  14. Modeling rule-based item generation

    NARCIS (Netherlands)

    Geerlings, Hanneke; Glas, Cornelis A.W.; van der Linden, Willem J.

    2011-01-01

    An application of a hierarchical IRT model for items in families generated through the application of different combinations of design rules is discussed. Within the families, the items are assumed to differ only in surface features. The parameters of the model are estimated in a Bayesian framework,

  15. Modelling gas generation in radioactive waste repositories

    International Nuclear Information System (INIS)

    Agg, P.J.

    1992-07-01

    In a repository containing low- and intermediate-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This paper describes a mathematical model designed to address gas generation by these mechanisms. The metal corrosion model incorporates a three-stage process encompassing both aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. Gas concentrations have been measured over a period of three years in large-scale drum experiments designed to simulate repository conditions. Model predictions are confirmed against the experimental measurements, and a prediction is then made of gas concentrations and generation rates over an assessment period of one million years in a radioactive waste repository. (Author)

  16. Modelling gas generation in radioactive waste repositories

    International Nuclear Information System (INIS)

    Agg, P.J.

    1993-02-01

    In a repository containing low- and intermediate-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This Paper describes a mathematical model design to address gas generation by these mechanisms. The metal corrosion model incorporates a three-stage process encompassing both aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. Gas concentrations have been measured over a period of three years in large-scale drum experiments designed to simulate repository conditions. Model predictions are confirmed against the experimental measurements, and a prediction is then made of gas concentrations and generation rates over an assessment period of one million years in a radioactive waste repository. (author)

  17. Workflow Fault Tree Generation Through Model Checking

    DEFF Research Database (Denmark)

    Herbert, Luke Thomas; Sharp, Robin

    2014-01-01

    We present a framework for the automated generation of fault trees from models of realworld process workflows, expressed in a formalised subset of the popular Business Process Modelling and Notation (BPMN) language. To capture uncertainty and unreliability in workflows, we extend this formalism...... to calculate the probabilities of reaching each non-error system state. Each generated error state is assigned a variable indicating its individual probability of occurrence. Our method can determine the probability of combined faults occurring, while accounting for the basic probabilistic structure...... of the system being modelled. From these calculations, a comprehensive fault tree is generated. Further, we show that annotating the model with rewards (data) allows the expected mean values of reward structures to be calculated at points of failure....

  18. A formal statistical approach to representing uncertainty in rainfall-runoff modelling with focus on residual analysis and probabilistic output evaluation - Distinguishing simulation and prediction

    DEFF Research Database (Denmark)

    Breinholt, Anders; Møller, Jan Kloppenborg; Madsen, Henrik

    2012-01-01

    evaluation of the modelled output, and we attach particular importance to inspecting the residuals of the model outputs and improving the model uncertainty description. We also introduce the probabilistic performance measures sharpness, reliability and interval skill score for model comparison...... and for checking the reliability of the confidence bounds. Using point rainfall and evaporation data as input and flow measurements from a sewer system for model conditioning, a state space model is formulated that accounts for three different flow contributions: wastewater from households, and fast rainfall......-runoff from paved areas and slow rainfall-dependent infiltration-inflow from unknown sources. We consider two different approaches to evaluate the model output uncertainty, the output error method that lumps all uncertainty into the observation noise term, and a method based on Stochastic Differential...

  19. Incorporation of an evolutionary algorithm to estimate transfer-functions for a parameter regionalization scheme of a rainfall-runoff model

    Science.gov (United States)

    Klotz, Daniel; Herrnegger, Mathew; Schulz, Karsten

    2016-04-01

    (Whitley et al., 1994), which might be understood as the idea that acquired characteristics during the lifetime of an individual can be transferred between generations. A hierarchical objective function is used for the model evaluation. This enables model preemption (Tolson et al., 2010) and reduces the amount of model evaluations in the early stages of optimization. References: • Samaniego, L., Kumar, R., Attinger, S. (2010): Multiscale parameter regionalization of a grid-based hydrologic model at the mesoscale, Water Resour. Res., doi: 10.1029/2008WR007327 • Kling, H., Stanzel, P., Fuchs, M., and Nachtnebel, H. P. (2014): Performance of the COSERO precipitation-runoff model under non-stationary conditions in basins with different climates, Hydrolog. Sci. J., doi:10.1080/02626667.2014.959956. • C. Ryan, J.J. Collins, Ji, Collins, M. O'Neil (1998): Evolving Programs for an Arbitrary Language, Lecture Notes in Computer Science 1391, Proceedings of the First European Workshop on Genetic Programming. • B.A. Tolson, S. Razavi, L.S. Matott, N.R. Thomson, A. MacLean, F.R. Seglenieks (2010): Reducing the computational cost of automatic calibration through model preemption, Water Resour. Res., 46, W11523, doi:10.1029/2009WR008957. • D. Whitley, S. Gordon, K. Mathias (1994): Lamarckian evolution, the Baldwin effect, and function optimization, in Parallel Problem Solving from Nature (PPSN) III, Y. Davidor, H.-P. Schwefel, and R. Manner, Eds. Berlin: Springer-Verlag, pp. 6-15.

  20. Snowmelt runoff from northern alpine tundra hillslopes: major processes and methods of simulation

    Directory of Open Access Journals (Sweden)

    W. L. Quinton

    2004-01-01

    Full Text Available In northern alpine tundra, large slope gradients, late-lying snow drifts and shallow soils overlying impermeable substrates all contribute to large hillslope runoff volumes during the spring freshet. Understanding the processes and pathways of hillslope runoff in this environment is, therefore, critical to understanding the water cycle within northern alpine tundra ecosystems. This study: (a presents the results of a field study on runoff from a sub-alpine tundra hillslope with a large snow drift during the spring melt period; (b identifies the major runoff processes that must be represented in simulations of snowmelt runoff from sub-alpine tundra hillslopes; (c describes how these processes can be represented in a numerical simulation model; and d compares field measurements with modelled output to validate or refute the conceptual understanding of runoff generation embodied in the process simulations. The study was conducted at Granger Creek catchment, 15 km south of Whitehorse, Yukon Territory, Canada, on a north-facing slope below a late-lying snow drift. For the freshet period, the major processes to be represented in a runoff model include the rate of meltwater release from the late-lying snowdrift, the elevation and thickness of the saturated layer, the magnitude of the soil permeability and its variation with depth. The daily cycle of net all-wave radiation was observed to drive the diurnal pulses of melt water from the drift; this, in turn, was found to control the daily pulses of flow through the hillslope subsurface and in the stream channel. The computed rate of frost table lowering fell within the observed values; however, there was wide variation among the measured frost table depths. Spatial variability in frost table depth would result in spatial variabilities in saturated layer depth and thickness, which would, in turn, produce variations in subsurface flow rates over the slope, including preferential flowpaths. Keywords

  1. Effects of rates and time of zeolite application on controlling runoff generation and soil loss from a soil subjected to a freeze-thaw cycle

    Directory of Open Access Journals (Sweden)

    Morteza Behzadfar

    2017-06-01

    Full Text Available Many factors such as freeze-thaw (FT cycle influence soil behavior. Application of soil amendments can play an important role on runoff time commencement (RT, volume (RV and soil loss (SL on soils subjected to FT cycles. However, limited studies have been documented on this subject. The present study was therefore carried out under rainfall simulation circumstances to investigate the effect of different rates of zeolite application to control the effects of FT on basic hydrological variables such as runoff production and soil loss. Towards this attempt, the effect of application of different rates of 250, 500 and 750 g m−2 of zeolite applied before, during and after the occurrence of FT cycle on RT, RV and SL was assessed in a completely randomized design. Treatments were set up in two categories viz. control (without zeolite application, and three rates and times of zeolite application in small 0.25 m2-experimental plots in three replications. The results showed that application of zeolite had significant effects on hydrological behavior of soil induced by FT cycles. Application rate of 750 g m−2 prior to FT cycle increased RT and reduced RV and SL at rates of 644%, 68% and 91%, respectively. The results also verified that zeolite could successfully mitigate the impacts of FT cycle on the main soil hydrological variables of soil profile induced by FT cycle. It is accordingly recommended to employ zeolite as an effective amendment to control soil erosion in steep and degraded rangelands where surface soil is exposed to rainfall and runoff.

  2. Generation and analysis of large reliability models

    Science.gov (United States)

    Palumbo, Daniel L.; Nicol, David M.

    1990-01-01

    An effort has been underway for several years at NASA's Langley Research Center to extend the capability of Markov modeling techniques for reliability analysis to the designers of highly reliable avionic systems. This effort has been focused in the areas of increased model abstraction and increased computational capability. The reliability model generator (RMG), a software tool which uses as input a graphical, object-oriented block diagram of the system, is discussed. RMG uses an automated failure modes-effects analysis algorithm to produce the reliability model from the graphical description. Also considered is the ASSURE software tool, a parallel processing program which uses the ASSIST modeling language and SURE semi-Markov solution technique. An executable failure modes-effects analysis is used by ASSURE. The successful combination of the power of graphical representation, automated model generation, and parallel computation leads to the conclusion that large system architectures can now be analyzed.

  3. 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.

  4. Wolf Creek Generating Station containment model

    International Nuclear Information System (INIS)

    Nguyen, D.H.; Neises, G.J.; Howard, M.L.

    1995-01-01

    This paper presents a CONTEMPT-LT/28 containment model that has been developed by Wolf Creek Nuclear Operating Corporation (WCNOC) to predict containment pressure and temperature behavior during the postulated events at Wolf Creek Generating Station (WCGS). The model has been validated using data provided in the WCGS Updated Safety Analysis Report (USAR). CONTEMPT-LT/28 model has been used extensively at WCGS to support plant operations, and recently, to support its 4.5% thermal power uprate project

  5. Trend analysis of runoff and sediment fluxes in the Upper Blue Nile basin: A combined analysis of statistical tests, physically-based models and landuse maps

    Science.gov (United States)

    Gebremicael, T. G.; Mohamed, Y. A.; Betrie, G. D.; van der Zaag, P.; Teferi, E.

    2013-03-01

    SummaryThe landuse/cover changes in the Ethiopian highlands have significantly increased the variability of runoff and sediment fluxes of the Blue Nile River during the last few decades. The objectives of this study were (i) to understand the long-term variations of runoff and sediment fluxes using statistical models, (ii) to interpret and corroborate the statistical results using a physically-based hydrological model, Soil and Water Assessment Tool (SWAT), and (iii) to validate the interpretation of SWAT results by assessing changes of landuse maps. Firstly, Mann-Kendall and Pettitt tests were used to test the trends of Blue Nile flow (1970-2009) and sediment load (1980-2009) at the outlet of the Upper Blue Nile basin at El Diem station. These tests showed statistically significant increasing trends of annual stream flow, wet season stream flow and sediment load at 5% confidence level. The dry season flow showed a significant decrease in the trend. However, during the same period the annual rainfall over the basin showed no significant trends. The results of the statistical tests were sensitive to the time domain. Secondly, the SWAT model was used to simulate the runoff and sediment fluxes in the early 1970s and at the end of the time series in 2000s in order to interpret the physical causes of the trends and corroborate the statistical results. A comparison of model parameter values between the 1970s and 2000s shows significant change, which could explain catchment response changes over the 28 years of record. Thirdly, a comparison of landuse maps of 1970s against 2000s shows conversion of vegetation cover into agriculture and grass lands over wide areas of the Upper Blue Nile basin. The combined results of the statistical tests, the SWAT model, and landuse change detection are consistent with the hypothesis that landuse change has caused a significant change of runoff and sediment load from the Upper Blue Nile during the last four decades. This is an important

  6. Land use and climate change impacts on runoff and soil erosion at the hillslope scale in the Brazilian Cerrado.

    Science.gov (United States)

    Anache, Jamil A A; Flanagan, Dennis C; Srivastava, Anurag; Wendland, Edson C

    2018-05-01

    Land use and climate change can influence runoff and soil erosion, threatening soil and water conservation in the Cerrado biome in Brazil. The adoption of a process-based model was necessary due to the lack of long-term observed data. Our goals were to calibrate the WEPP (Water Erosion Prediction Project) model for different land uses under subtropical conditions in the Cerrado biome; predict runoff and soil erosion for these different land uses; and simulate runoff and soil erosion considering climate change. We performed the model calibration using a 5-year dataset (2012-2016) of observed runoff and soil loss in four different land uses (wooded Cerrado, tilled fallow without plant cover, pasture, and sugarcane) in experimental plots. Selected soil and management parameters were optimized for each land use during the WEPP model calibration with the existing field data. The simulations were conducted using the calibrated WEPP model components with a 100-year climate dataset created with CLIGEN (weather generator) based on regional climate statistics. We obtained downscaled General Circulation Model (GCM) projections, and runoff and soil loss were predicted with WEPP using future climate scenarios for 2030, 2060, and 2090 considering different Representative Concentration Pathways (RCPs). The WEPP model had an acceptable performance for the subtropical conditions. Land use can influence runoff and soil loss rates in a significant way. Potential climate changes, which indicate the increase of rainfall intensities and depths, may increase the variability and rates of runoff and soil erosion. However, projected climate changes did not significantly affect the runoff and soil erosion for the four analyzed land uses at our location. Finally, the runoff behavior was distinct for each land use, but for soil loss we found similarities between pasture and wooded Cerrado, suggesting that the soil may attain a sustainable level when the land management follows conservation

  7. Learning generative models for protein fold families.

    Science.gov (United States)

    Balakrishnan, Sivaraman; Kamisetty, Hetunandan; Carbonell, Jaime G; Lee, Su-In; Langmead, Christopher James

    2011-04-01

    We introduce a new approach to learning statistical models from multiple sequence alignments (MSA) of proteins. Our method, called GREMLIN (Generative REgularized ModeLs of proteINs), learns an undirected probabilistic graphical model of the amino acid composition within the MSA. The resulting model encodes both the position-specific conservation statistics and the correlated mutation statistics between sequential and long-range pairs of residues. Existing techniques for learning graphical models from MSA either make strong, and often inappropriate assumptions about the conditional independencies within the MSA (e.g., Hidden Markov Models), or else use suboptimal algorithms to learn the parameters of the model. In contrast, GREMLIN makes no a priori assumptions about the conditional independencies within the MSA. We formulate and solve a convex optimization problem, thus guaranteeing that we find a globally optimal model at convergence. The resulting model is also generative, allowing for the design of new protein sequences that have the same statistical properties as those in the MSA. We perform a detailed analysis of covariation statistics on the extensively studied WW and PDZ domains and show that our method out-performs an existing algorithm for learning undirected probabilistic graphical models from MSA. We then apply our approach to 71 additional families from the PFAM database and demonstrate that the resulting models significantly out-perform Hidden Markov Models in terms of predictive accuracy. Copyright © 2011 Wiley-Liss, Inc.

  8. The ModelCC Model-Driven Parser Generator

    Directory of Open Access Journals (Sweden)

    Fernando Berzal

    2015-01-01

    Full Text Available Syntax-directed translation tools require the specification of a language by means of a formal grammar. This grammar must conform to the specific requirements of the parser generator to be used. This grammar is then annotated with semantic actions for the resulting system to perform its desired function. In this paper, we introduce ModelCC, a model-based parser generator that decouples language specification from language processing, avoiding some of the problems caused by grammar-driven parser generators. ModelCC receives a conceptual model as input, along with constraints that annotate it. It is then able to create a parser for the desired textual syntax and the generated parser fully automates the instantiation of the language conceptual model. ModelCC also includes a reference resolution mechanism so that ModelCC is able to instantiate abstract syntax graphs, rather than mere abstract syntax trees.

  9. Using a geographic information system and hillslope runoff modeling to support decision-making for managed aquifer recharge using distributed stormwater collection

    Science.gov (United States)

    Teo, E. K.; Beganskas, S.; Young, K. S.; Weir, W. B.; Harmon, R. E.; Lozano, S.; Fisher, A. T.

    2017-12-01

    Many aquifer systems in central coastal California face a triple threat of excess demand, changing land use, and a shifting climate. These last two factors can contribute to reductions in groundwater recharge. Managed aquifer recharge using distributed stormwater collection (DSC-MAR) is an adaptation technique for collecting excess stormwater runoff from hillslopes for infiltration into underlying aquifers, before that water reaches a "blue line" stream. We are developing a decision support system (DSS) that combines surface and subsurface hydrogeological data with high-resolution predictions of hillslope runoff, with specific application to Santa Cruz and northern Monterey Counties. Other studies presented at AGU will focus on the northern and southern parts of our study region (San Lorenzo River Basin, Lower Pajaro River Basin). This presentation focuses on mid-Santa Cruz County, including the Soquel-Aptos Groundwater Basin. The DSS uses a geographic information system to compile and merge data from numerous local, state, and federal sources to identify locations on the landscape where DSC-MAR may be most suitable. This requires classification of disparate data types so that they can be combined. Stormwater runoff for individual river basins in the study region was simulated using historical streamflow data for calibration and validation. Both analyses were completed with relatively fine resolution, from 10 m2 pixels for elevation to 0.1-1.0 km hydrologic response units for properties such as soil and vegetation properties. Future climate is uncertain, so we used historical data to create a catalog of dry, normal, and wet hydrologic conditions, then created synthetic future climate scenarios for simulation. The DDS shows that there are numerous regions in mid-Santa Cruz County where there is a confluence of MAR suitability and the generation of stormwater runoff that could supply recharge projects (with a nominal target of 100 ac-ft/yr of infiltration), even

  10. A precipitation-runoff model for simulating natural streamflow conditions in the Smith River watershed, Montana, water years 1996-2008

    Science.gov (United States)

    Chase, Katherine J.; Caldwell, Rodney R.; Stanley, Andrea K.

    2014-01-01

    This report documents the construction of a precipitation-runoff model for simulating natural streamflow in the Smith River watershed, Montana. This Precipitation-Runoff Modeling System model, constructed in cooperation with the Meagher County Conservation District, can be used to examine the general hydrologic framework of the Smith River watershed, including quantification of precipitation, evapotranspiration, and streamflow; partitioning of streamflow between surface runoff and subsurface flow; and quantifying contributions to streamflow from several parts of the watershed. The model was constructed by using spatial datasets describing watershed topography, the streams, and the hydrologic characteristics of the basin soils and vegetation. Time-series data (daily total precipitation, and daily minimum and maximum temperature) were input to the model to simulate daily streamflow. The model was calibrated for water years 2002–2007 and evaluated for water years 1996–2001. Though water year 2008 was included in the study period to evaluate water-budget components, calibration and evaluation data were unavailable for that year. During the calibration and evaluation periods, simulated-natural flow values were compared to reconstructed-natural streamflow data. These reconstructed-natural streamflow data were calculated by adding Bureau of Reclamation’s depletions data to the observed streamflows. Reconstructed-natural streamflows represent estimates of streamflows for water years 1996–2007 assuming there was no agricultural water-resources development in the watershed. Additional calibration targets were basin mean monthly solar radiation and potential evapotranspiration. The model estimated the hydrologic processes in the Smith River watershed during the calibration and evaluation periods. Simulated-natural mean annual and mean monthly flows generally were the same or higher than the reconstructed-natural streamflow values during the calibration period, whereas

  11. Prediction of Estrogen Runoff and Transport Driven by Rainfalls from Swine Spray Fields

    Science.gov (United States)

    Lee, B.; Reckhow, K. H.; Kullman, S. W.

    2010-12-01

    Animal waste-borne steroidal hormones, which are referred to as natural steroidal estrogens, are recognized pollutants to surface water systems. Steroidal estrogens exhibit strong potency, even at very low concentrations, as endocrine disrupting chemicals on aquatic organisms. In North Carolina, the swine concentrated animal feeding operations (CAFOs) have been a major source for the release of estrogens to watersheds. Release is a direct result of the land application of the generated waste as an organic fertilizer. However, data regarding the estrogen loss and transport through the surface runoff and soil erosion to the water bodies after the spray-fields application has been up till now very limited. We have developed a decision support tool that can help predict and ultimately manage the potential mobilization and transport of estrogens from CAFOs, through the processes of surface runoff transport and sediment loss, into adjacent water bodies. Our decision support tool was built using a dynamic Bayesian Network (DBN) framework. The developed DBN model integrates the processes of a sediment loss and a surface runoff by using the modified universal soil loss equation (MUSLE) and the SCS-CN curve runoff models. Estrogen mobility is assessed as a function of rainfall intensity and land use management with consideration to the temporal distribution of both. The DBN is used to model the estrogen concentration in the runoff process, to determine the degree of off-site movement of estrogens, and to verify the potential environmental significance of the estrogen inputs into the stream. We believe that our modeling framework is particularly useful for use in field situations where estrogen runoff data are not available or are scarce. The DBN model also provides a means to handle the uncertainties of mathematical sediment and runoff models as a dynamic probability model.

  12. Modelling the horizontal steam generator with APROS

    Energy Technology Data Exchange (ETDEWEB)

    Ylijoki, J. [VTT Energy, Espoo (Finland); Palsinajaervi, C.; Porkholm, K. [IVO International Ltd, Vantaa (Finland)

    1995-12-31

    In this paper the capability of the five- and six-equation models of the simulation code APROS to simulate the behaviour of the horizontal steam generator is discussed. Different nodalizations are used in the modelling and the results of the stationary state runs are compared. Exactly the same nodalizations have been created for the five- and six-equation models. The main simulation results studied in this paper are void fraction and mass flow distributions in the secondary side of the steam generator. It was found that quite a large number of simulation volumes is required to simulate the distributions with a reasonable accuracy. The simulation results of the different models are presented and their validity is discussed. (orig.). 4 refs.

  13. Alternative methods of modeling wind generation using production costing models

    International Nuclear Information System (INIS)

    Milligan, M.R.; Pang, C.K.

    1996-08-01

    This paper examines the methods of incorporating wind generation in two production costing models: one is a load duration curve (LDC) based model and the other is a chronological-based model. These two models were used to evaluate the impacts of wind generation on two utility systems using actual collected wind data at two locations with high potential for wind generation. The results are sensitive to the selected wind data and the level of benefits of wind generation is sensitive to the load forecast. The total production cost over a year obtained by the chronological approach does not differ significantly from that of the LDC approach, though the chronological commitment of units is more realistic and more accurate. Chronological models provide the capability of answering important questions about wind resources which are difficult or impossible to address with LDC models

  14. Instance-Based Generative Biological Shape Modeling.

    Science.gov (United States)

    Peng, Tao; Wang, Wei; Rohde, Gustavo K; Murphy, Robert F

    2009-01-01

    Biological shape modeling is an essential task that is required for systems biology efforts to simulate complex cell behaviors. Statistical learning methods have been used to build generative shape models based on reconstructive shape parameters extracted from microscope image collections. However, such parametric modeling approaches are usually limited to simple shapes and easily-modeled parameter distributions. Moreover, to maximize the reconstruction accuracy, significant effort is required to design models for specific datasets or patterns. We have therefore developed an instance-based approach to model biological shapes within a shape space built upon diffeomorphic measurement. We also designed a recursive interpolation algorithm to probabilistically synthesize new shape instances using the shape space model and the original instances. The method is quite generalizable and therefore can be applied to most nuclear, cell and protein object shapes, in both 2D and 3D.

  15. Predicting Surface Runoff from Catchment to Large Region

    Directory of Open Access Journals (Sweden)

    Hongxia Li

    2015-01-01

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

  16. Deep Generative Models for Molecular Science

    DEFF Research Database (Denmark)

    Jørgensen, Peter Bjørn; Schmidt, Mikkel Nørgaard; Winther, Ole

    2018-01-01

    Generative deep machine learning models now rival traditional quantum-mechanical computations in predicting properties of new structures, and they come with a significantly lower computational cost, opening new avenues in computational molecular science. In the last few years, a variety of deep...

  17. A Knowledge Generation Model via the Hypernetwork

    Science.gov (United States)

    Liu, Jian-Guo; Yang, Guang-Yong; Hu, Zhao-Long

    2014-01-01

    The influence of the statistical properties of the network on the knowledge diffusion has been extensively studied. However, the structure evolution and the knowledge generation processes are always integrated simultaneously. By introducing the Cobb-Douglas production function and treating the knowledge growth as a cooperative production of knowledge, in this paper, we present two knowledge-generation dynamic evolving models based on different evolving mechanisms. The first model, named “HDPH model,” adopts the hyperedge growth and the hyperdegree preferential attachment mechanisms. The second model, named “KSPH model,” adopts the hyperedge growth and the knowledge stock preferential attachment mechanisms. We investigate the effect of the parameters on the total knowledge stock of the two models. The hyperdegree distribution of the HDPH model can be theoretically analyzed by the mean-field theory. The analytic result indicates that the hyperdegree distribution of the HDPH model obeys the power-law distribution and the exponent is . Furthermore, we present the distributions of the knowledge stock for different parameters . The findings indicate that our proposed models could be helpful for deeply understanding the scientific research cooperation. PMID:24626143

  18. Risk assessment of pesticide runoff from turf.

    Science.gov (United States)

    Haith, Douglas A; Rossi, Frank S

    2003-01-01

    The TurfPQ model was used to simulate the runoff of 15 pesticides commonly applied to creeping bentgrass (Agrostis stolonifera L.) fairways and greens on golf courses in the northeastern USA. Simulations produced 100-yr daily records of water runoff, pesticide runoff, and pesticide concentration in runoff for three locations: Boston, MA, Philadelphia, PA, and Rochester, NY. Results were summarized as annual and monthly means and annual maximum daily loads (AMDLs) corresponding to 10- and 20-yr return periods. Mean annual pesticide runoff loads did not exceed 3% of annual applications for any pesticide or site, and most losses were substantially less than 1% of application. However, annual or monthly mean concentrations of chlorothalonil, iprodione, and PCNB in fairway runoff often exceeded concentrations that result in 50% mortality of the affected species (LC50) for aquatic organisms. Concentrations of azoxystrobin, bensulide, cyfluthrin, and trichlorfon in extreme (1 in 10 yr or 1 in 20 yr) events often approached or exceeded LC50 levels. Concentrations of halofenozide, mancozeb, MCPP, oxadiazon, propiconazole, thiophanate-methyl, triadimefon, and trinexapac-ethyl were well below LC50 levels, and turf runoff of these chemicals does not appear to be hazardous to aquatic life in surface waters.

  19. Estimation of potential loss of two pesticides in runoff in Fillmore County, Minnesota using a field-scale process-based model and a geographic information system

    Science.gov (United States)

    Capel, P.D.; Zhang, H.

    2000-01-01

    In assessing the occurrence, behavior, and effects of agricultural chemicals in surface water, the scales of study (i.e., watershed, county, state, and regional areas) are usually much larger than the scale of agricultural fields, where much of the understanding of processes has been developed. Field-scale areas are characterized by relatively homogeneous conditions. The combination of process-based simulation models and geographic information system technology can be used to help extend our understanding of field processes to water-quality concerns at larger scales. To demonstrate this, the model "Groundwater Loading Effects of Agricultural Management Systems" was used to estimate the potential loss of two pesticides (atrazine and permethrin) in runoff to surface water in Fillmore County in southeastern Minnesota. The county was divided into field-scale areas on the basis of a 100 m by 100 m grid, and the influences of soil type and surface topography on the potential losses of the two pesticides in runoff was evaluated for each individual grid cell. The results could be used for guidance for agricultural management and regulatory decisions, for planning environmental monitoring programs, and as an educational tool for the public.

  20. 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.

  1. Computer modeling of pesticide fate at the hillslope scale. Influence of vegetated filter strips on surface runoff pesticides transfer and partitioning between surface and subsurface fluxes

    Science.gov (United States)

    Djabelkhir, K.; Carluer, N.; Lauvernet, C.

    2012-04-01

    In France, agriculture uses large quantities of fertilizer and pesticides. Water contamination by pesticides is highlighted by monitoring networks, at local and national levels. Control and reduction of contamination are major issues, for the protection of drinking water resources and aquatic ecosystems. Thus, understanding and quantifying the mechanisms involved in mobilization, transfer and dissipation of these substances can help to perform risk of water contamination diagnosis, and to estimate the effectiveness of corrective solutions. In this context, landscape elements, like buffer zones, can be an effective way to reduce diffuse contamination of pesticides carried by surface runoff. They protect the water ressources of the drift of the products applied to crops and contribute to the reduction of the transfer of pesticides in surface runoff from the plots to the river. We are interested in our study to the vegetative filter strips. The main objective of this thesis is to develop a model simulating the processes governing the transfer and dissipation of pesticides from plots to surface water, on surface and subsurface, along a slope. This will be done by taking into account the influence of vegetative filter strips between plots and rivers on the transfer, by changing the flow paths and retention time of these products via several mechanisms (infiltration, filtration of runoff -sedimentation of MES-, adsorption and degradation of products on the surface of the vegetative filter strips or infiltrated). Several models describing the mechanisms of transfer of water and solutes (sometimes) at a hillslope scale exist, in particular : POLA (Pinheiro and al., 1995), Openfluid (LISAH), J2000-JAMS (Krause and al., 2006), CatFlow (Zehe and al., 2000), tRIBS (Ivanov and al., 2004), Cathy 3D (Bixio and al., 2000) and CMF (Kraft and al., 2011). It was decided to choose a spatially distributed and object-oriented model, allowing to couple hydrological processes occuring

  2. A generative model for predicting terrorist incidents

    Science.gov (United States)

    Verma, Dinesh C.; Verma, Archit; Felmlee, Diane; Pearson, Gavin; Whitaker, Roger

    2017-05-01

    A major concern in coalition peace-support operations is the incidence of terrorist activity. In this paper, we propose a generative model for the occurrence of the terrorist incidents, and illustrate that an increase in diversity, as measured by the number of different social groups to which that an individual belongs, is inversely correlated with the likelihood of a terrorist incident in the society. A generative model is one that can predict the likelihood of events in new contexts, as opposed to statistical models which are used to predict the future incidents based on the history of the incidents in an existing context. Generative models can be useful in planning for persistent Information Surveillance and Reconnaissance (ISR) since they allow an estimation of regions in the theater of operation where terrorist incidents may arise, and thus can be used to better allocate the assignment and deployment of ISR assets. In this paper, we present a taxonomy of terrorist incidents, identify factors related to occurrence of terrorist incidents, and provide a mathematical analysis calculating the likelihood of occurrence of terrorist incidents in three common real-life scenarios arising in peace-keeping operations

  3. Urban runoff forecasting with ensemble weather predictions

    DEFF Research Database (Denmark)

    Pedersen, Jonas Wied; Courdent, Vianney Augustin Thomas; Vezzaro, Luca

    This research shows how ensemble weather forecasts can be used to generate urban runoff forecasts up to 53 hours into the future. The results highlight systematic differences between ensemble members that needs to be accounted for when these forecasts are used in practice.......This research shows how ensemble weather forecasts can be used to generate urban runoff forecasts up to 53 hours into the future. The results highlight systematic differences between ensemble members that needs to be accounted for when these forecasts are used in practice....

  4. Rivers, runoff, and reefs

    Science.gov (United States)

    McLaughlin, C.J.; Smith, C.A.; Buddemeier, R.W.; Bartley, J.D.; Maxwell, B.A.

    2003-01-01

    The role of terrigenous sediment in controlling the occurrence of coral reef ecosystems is qualitatively understood and has been studied at local scales, but has not been systematically evaluated on a global-to-regional scale. Current concerns about degradation of reef environments and alteration of the hydrologic and sediment cycles place the issue at a focal point of multiple environmental concerns. We use a geospatial clustering of a coastal zone database of river and local runoff identified with 0.5?? grid cells to identify areas of high potential runoff effects, and combine this with a database of reported coral reef locations. Coastal cells with high runoff values are much less likely to contain reefs than low runoff cells and GIS buffer analysis demonstrates that this inhibition extends to offshore ocean cells as well. This analysis does not uniquely define the effects of sediment, since salinity, nutrients, and contaminants are potentially confounding variables also associated with runoff. However, sediment effects are likely to be a major factor and a basis is provided for extending the study to higher resolution with more specific variables. ?? 2003 Elsevier B.V. All rights reserved.

  5. Interception of rainfall and surface runoff in the Brazilian Cerrado

    Science.gov (United States)

    Tarso Oliveira, Paulo; Wendland, Edson; Nearing, Mark; Perea Martins, João

    2014-05-01

    The Brazilian Cerrado plays a fundamental role in water resources dynamics because it distributes fresh water to the largest basins in Brazil and South America. In recent decades, the native Cerrado vegetation has increasingly been replaced by agricultural crops and pasture. These land cover and land use changes have altered the hydrological processes. Meanwhile, little is known about the components of the water balance in the Brazilian Cerrado, mainly because the experimental field studies in this region are scarce or nonexistent. The objective of this study was to evaluate two hydrological processes under native Cerrado vegetation, the canopy interception (CI) and the surface runoff (R). The Cerrado physiognomy was classified as "cerrado sensu stricto denso" with an absolute density of 15,278 trees ha-1, and a basal area of 11.44 m2 ha-1. We measured the gross rainfall (P) from an automated tipping bucket rain gauge (model TB4) located in a tower with 11 m of height on the Cerrado. Throughfall (TF) was obtained from 15 automated tipping bucket rain gauges (model Davis) spread below the Cerrado vegetation and randomly relocated every month during the wet season. Stemflow (SF) was measured on 12 trees using a plastic hose wrapped around the trees trunks, sealed with neutral silicone sealant, and a bucket to store the water. The canopy interception was computed by the difference between P and the sum of TF and SF. Surface runoff under undisturbed Cerrado was collected in three plots of 100 m2(5 x 20 m) in size and slope steepness of approximately 0.09 m m-1. The experimental study was conducted between January 2012 and November 2013. We found TF of 81.0% of P and SF of 1.6% of P, i.e. the canopy interception was calculated at 17.4% of P. There was a statistically significant correlation (p 0.8. Our results suggest that the rainfall intensity, the characteristics of the trees trunks (crooked and twisted) and stand structure are the main factors that have influenced

  6. Assimilation of snow cover and snow depth into a snow model to estimate snow water equivalent and snowmelt runoff in a Himalayan catchment

    Directory of Open Access Journals (Sweden)

    E. E. Stigter

    2017-07-01

    Full Text Available Snow is an important component of water storage in the Himalayas. Previous snowmelt studies in the Himalayas have predominantly relied on remotely sensed snow cover. However, snow cover data provide no direct information on the actual amount of water stored in a snowpack, i.e., the snow water equivalent (SWE. Therefore, in this study remotely sensed snow cover was combined with in situ observations and a modified version of the seNorge snow model to estimate (climate sensitivity of SWE and snowmelt runoff in the Langtang catchment in Nepal. Snow cover data from Landsat 8 and the MOD10A2 snow cover product were validated with in situ snow cover observations provided by surface temperature and snow depth measurements resulting in classification accuracies of 85.7 and 83.1 % respectively. Optimal model parameter values were obtained through data assimilation of MOD10A2 snow maps and snow depth measurements using an ensemble Kalman filter (EnKF. Independent validations of simulated snow depth and snow cover with observations show improvement after data assimilation compared to simulations without data assimilation. The approach of modeling snow depth in a Kalman filter framework allows for data-constrained estimation of snow depth rather than snow cover alone, and this has great potential for future studies in complex terrain, especially in the Himalayas. Climate sensitivity tests with the optimized snow model revealed that snowmelt runoff increases in winter and the early melt season (December to May and decreases during the late melt season (June to September as a result of the earlier onset of snowmelt due to increasing temperature. At high elevation a decrease in SWE due to higher air temperature is (partly compensated by an increase in precipitation, which emphasizes the need for accurate predictions on the changes in the spatial distribution of precipitation along with changes in temperature.

  7. Modeling and Simulation of Generator Side Converter of Doubly Fed Induction Generator-Based Wind Power Generation System

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Blaabjerg, Frede

    2010-01-01

    A real wind power generation system is given in this paper. SVM control strategy and vector control is applied for generator side converter and doubly fed induction generator respectively. First the mathematical models of the wind turbine rotor, drive train, generator side converter are described....... Then the control strategy of generator side converter system is given in detail. Finally the simulation model of the generator side converter system is set up. The simulation results have verified that it is feasible to apply for generator side converter of wind power generation system and the generator side...

  8. Ontology modeling for generation of clinical pathways

    Directory of Open Access Journals (Sweden)

    Jasmine Tehrani

    2012-12-01

    Full Text Available Purpose: Increasing costs of health care, fuelled by demand for high quality, cost-effective healthcare has drove hospitals to streamline their patient care delivery systems. One such systematic approach is the adaptation of Clinical Pathways (CP as a tool to increase the quality of healthcare delivery. However, most organizations still rely on are paper-based pathway guidelines or specifications, which have limitations in process management and as a result can influence patient safety outcomes. In this paper, we present a method for generating clinical pathways based on organizational semiotics by capturing knowledge from syntactic, semantic and pragmatic to social level. Design/methodology/approach: The proposed modeling approach to generation of CPs adopts organizational semiotics and enables the generation of semantically rich representation of CP knowledge. Semantic Analysis Method (SAM is applied to explicitly represent the semantics of the concepts, their relationships and patterns of behavior in terms of an ontology chart. Norm Analysis Method (NAM is adopted to identify and formally specify patterns of behavior and rules that govern the actions identified on the ontology chart. Information collected during semantic and norm analysis is integrated to guide the generation of CPs using best practice represented in BPMN thus enabling the automation of CP. Findings: This research confirms the necessity of taking into consideration social aspects in designing information systems and automating CP. The complexity of healthcare processes can be best tackled by analyzing stakeholders, which we treat as social agents, their goals and patterns of action within the agent network. Originality/value: The current modeling methods describe CPs from a structural aspect comprising activities, properties and interrelationships. However, these methods lack a mechanism to describe possible patterns of human behavior and the conditions under which the

  9. Model documentation report: Short-Term Hydroelectric Generation Model

    International Nuclear Information System (INIS)

    1993-08-01

    The purpose of this report is to define the objectives of the Short- Term Hydroelectric Generation Model (STHGM), describe its basic approach, and to provide details on the model structure. This report is intended as a reference document for model analysts, users, and the general public. Documentation of the model is in accordance with the Energy Information Administration's (AYE) legal obligation to provide adequate documentation in support of its models (Public Law 94-385, Section 57.b.2). The STHGM performs a short-term (18 to 27- month) forecast of hydroelectric generation in the United States using an autoregressive integrated moving average (UREMIA) time series model with precipitation as an explanatory variable. The model results are used as input for the short-term Energy Outlook

  10. GIS based generation of dynamic hydrological and land patch simulation models for rural watershed areas

    Directory of Open Access Journals (Sweden)

    M. Varga

    2016-03-01

    Full Text Available This paper introduces a GIS based methodology to generate dynamic process model for the simulation based analysis of a sensitive rural watershed. The Direct Computer Mapping (DCM based solution starts from GIS layers and, via the graph interpretation and graphical edition of the process network, the expert interface is able to integrate the field experts’ knowledge in the computer aided generation of the simulation model. The methodology was applied and tested for the Southern catchment basin of Lake Balaton, Hungary. In the simplified hydrological model the GIS description of nine watercourses, 121 water sections, 57 small lakes and 20 Lake Balaton compartments were mapped through the expert interface to the dynamic databases of the DCM model. The hydrological model involved precipitation, evaporation, transpiration, runoff, infiltration. The COoRdination of INformation on the Environment (CORINE land cover based simplified “land patch” model considered the effect of meteorological and hydrological scenarios on freshwater resources in the land patches, rivers and lakes. The first results show that the applied model generation methodology helps to build complex models, which, after validation can support the analysis of various land use, with the consideration of environmental aspects.

  11. Estimation of urban runoff and water quality using remote sensing and artificial intelligence.

    Science.gov (United States)

    Ha, S R; Park, S Y; Park, D H

    2003-01-01

    Water quality and quantity of runoff are strongly dependent on the landuse and landcover (LULC) criteria. In this study, we developed a more improved parameter estimation procedure for the environmental model using remote sensing (RS) and artificial intelligence (AI) techniques. Landsat TM multi-band (7bands) and Korea Multi-Purpose Satellite (KOMPSAT) panchromatic data were selected for input data processing. We employed two kinds of artificial intelligence techniques, RBF-NN (radial-basis-function neural network) and ANN (artificial neural network), to classify LULC of the study area. A bootstrap resampling method, a statistical technique, was employed to generate the confidence intervals and distribution of the unit load. SWMM was used to simulate the urban runoff and water quality and applied to the study watershed. The condition of urban flow and non-point contaminations was simulated with rainfall-runoff and measured water quality data. The estimated total runoff, peak time, and pollutant generation varied considerably according to the classification accuracy and percentile unit load applied. The proposed procedure would efficiently be applied to water quality and runoff simulation in a rapidly changing urban area.

  12. The paradoxical evolution of runoff in the pastoral Sahel: analysis of the hydrological changes over the Agoufou watershed (Mali using the KINEROS-2 model

    Directory of Open Access Journals (Sweden)

    L. Gal

    2017-09-01

    Full Text Available In recent decades, the Sahel has witnessed a paradoxical increase in surface water despite a general precipitation decline. This phenomenon, commonly referred to as the Sahelian paradox, is not completely understood yet. The role of cropland expansion due to the increasing food demand by a growing population has been often put forward to explain this situation for the cultivated Sahel. However, this hypothesis does not hold in pastoral areas where the same phenomenon is observed. Several other processes, such as the degradation of natural vegetation following the major droughts of the 1970s and the 1980s, the development of crusted topsoils, the intensification of the rainfall regime and the development of the drainage network, have been suggested to account for this situation. In this paper, a modeling approach is proposed to explore, quantify and rank different processes that could be at play in pastoral Sahel. The kinematic runoff and erosion model (KINEROS-2 is applied to the Agoufou watershed (245 km2, in the Gourma region in Mali, which underwent a significant increase of surface runoff during the last 60 years. Two periods are simulated, the past case (1960–1975 preceding the Sahelian drought and the present case (2000–2015. Surface hydrology and land cover characteristics for these two periods are derived by the analysis of aerial photographs, available in 1956, and high-resolution remote sensing images in 2011. The major changes identified are (1 a partial crusting of isolated dunes, (2 an increase of drainage network density, (3 a marked decrease in vegetation with the nonrecovery of tiger bush and vegetation growing on shallow sandy soils, and (4 important changes in soil properties with the apparition of impervious soils instead of shallow sandy soil. The KINEROS-2 model was parameterized to simulate these changes in combination or independently. The results obtained by this model display a significant increase in annual

  13. The paradoxical evolution of runoff in the pastoral Sahel: analysis of the hydrological changes over the Agoufou watershed (Mali) using the KINEROS-2 model

    Science.gov (United States)

    Gal, Laetitia; Grippa, Manuela; Hiernaux, Pierre; Pons, Léa; Kergoat, Laurent

    2017-09-01

    In recent decades, the Sahel has witnessed a paradoxical increase in surface water despite a general precipitation decline. This phenomenon, commonly referred to as the Sahelian paradox, is not completely understood yet. The role of cropland expansion due to the increasing food demand by a growing population has been often put forward to explain this situation for the cultivated Sahel. However, this hypothesis does not hold in pastoral areas where the same phenomenon is observed. Several other processes, such as the degradation of natural vegetation following the major droughts of the 1970s and the 1980s, the development of crusted topsoils, the intensification of the rainfall regime and the development of the drainage network, have been suggested to account for this situation. In this paper, a modeling approach is proposed to explore, quantify and rank different processes that could be at play in pastoral Sahel. The kinematic runoff and erosion model (KINEROS-2) is applied to the Agoufou watershed (245 km2), in the Gourma region in Mali, which underwent a significant increase of surface runoff during the last 60 years. Two periods are simulated, the past case (1960-1975) preceding the Sahelian drought and the present case (2000-2015). Surface hydrology and land cover characteristics for these two periods are derived by the analysis of aerial photographs, available in 1956, and high-resolution remote sensing images in 2011. The major changes identified are (1) a partial crusting of isolated dunes, (2) an increase of drainage network density, (3) a marked decrease in vegetation with the nonrecovery of tiger bush and vegetation growing on shallow sandy soils, and (4) important changes in soil properties with the apparition of impervious soils instead of shallow sandy soil. The KINEROS-2 model was parameterized to simulate these changes in combination or independently. The results obtained by this model display a significant increase in annual discharge between the

  14. THE IMPACT OF URBAN RUN-OFF ON OGBOR RIVER

    African Journals Online (AJOL)

    Dr Obe

    Impact of urban run-off on Ogbor River in Aba metropolis has been studied. The run-off ... of wastes are generated in the solid, liquid and gaseous ... wastes [3]. At high temperature and low pH, heavy metals can cause stunted growth and death of most marine organisms. Human beings can also be affected by drinking water.

  15. Modelling surface runoff and water fluxes over contrasted soils in pastoral Sahel: evaluation of the ALMIP2 land surface models over the Gourma region in Mali

    Science.gov (United States)

    Land surface processes play an important role in West African monsoon variability and land –atmosphere coupling has been shown to be particularly important in the Sahel. In addition, the evolution of hydrological systems in this region, and particularly the increase of surface water and runoff coeff...

  16. Propagation of soil moisture memory to runoff and evapotranspiration

    Science.gov (United States)

    Orth, R.; Seneviratne, S. I.

    2012-10-01

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

  17. Use of a stochastic approach for description of water balance and runoff production dynamics

    Science.gov (United States)

    Gioia, A.; Manfreda, S.; Iacobellis, V.; Fiorentino, M.

    2009-04-01

    The present study exploits an analytical model (Manfreda, NHESS [2008]) for the description of the probability density function of soil water balance and runoff generation over a set of river basins belonging to Southern Italy. The model is based on a stochastic differential equation where the rainfall forcing is interpreted as an additive noise in the soil water balance; the watershed heterogeneity is described exploiting the conceptual lumped watershed Xinanjiang model (widely used in China) that uses a parabolic curve for the distribution of the soil water storage capacity (Zhao et al. [1980]). The model, characterized by parameters that depend on soil, vegetation and basin morphology, allowed to derive the probability density function of the relative saturation and the surface runoff of a basin accounting for the spatial heterogeneity in soil water storage. Its application on some river basins belonging to regions of Southern Italy, gives interesting insights for the investigation of the role played by the dynamical interaction between climate, soil, and vegetation in soil moisture and runoff production dynamics. Manfreda, S., Runoff Generation Dynamics within a Humid River Basin, Natural Hazard and Earth System Sciences, 8, 1349-1357, 2008. Zhao, R. -J., Zhang, Y. L., and Fang, L. R.: The Xinanjiang model, Hydrological Forecasting Proceedings Oxford Symposium, IAHS Pub. 129, 351-356, 1980.

  18. Long term high resolution rainfall runoff observations for improved water balance uncertainty and database QA-QC in the Walnut Gulch Experimental Watershed.

    Science.gov (United States)

    Bitew, M. M.; Goodrich, D. C.; Demaria, E.; Heilman, P.; Kautz, M. A.

    2017-12-01

    Walnut Gulch is a semi-arid environment experimental watershed and Long Term Agro-ecosystem Research (LTAR) site managed by USDA-ARS Southwest Watershed Research Center for which high-resolution long-term hydro-climatic data are available across its 150 km2 drainage area. In this study, we present the analysis of 50 years of continuous hourly rainfall data to evaluate runoff control and generation processes for improving the QA-QC plans of Walnut Gulch to create high-quality data set that is critical for reducing water balance uncertainties. Multiple linear regression models were developed to relate rainfall properties, runoff characteristics and watershed properties. The rainfall properties were summarized to event based total depth, maximum intensity, duration, the location of the storm center with respect to the outlet, and storm size normalized to watershed area. We evaluated the interaction between the runoff and rainfall and runoff as antecedent moisture condition (AMC), antecedent runoff condition (ARC) and, runoff depth and duration for each rainfall events. We summarized each of the watershed properties such as contributing area, slope, shape, channel length, stream density, channel flow area, and percent of the area of retention stock ponds for each of the nested catchments in Walnut Gulch. The evaluation of the model using basic and categorical statistics showed good predictive skill throughout the watersheds. The model produced correlation coefficients ranging from 0.4-0.94, Nash efficiency coefficients up to 0.77, and Kling-Gupta coefficients ranging from 0.4 to 0.98. The model predicted 92% of all runoff generations and 98% of no-runoff across all sub-watersheds in Walnut Gulch. The regression model also indicated good potential to complement the QA-QC procedures in place for Walnut Gulch dataset publications developed over the years since the 1960s through identification of inconsistencies in rainfall and runoff relations.

  19. A quantitative microbial risk assessment model for total coliforms and E. coli in surface runoff following application of biosolids to grassland.

    Science.gov (United States)

    Clarke, Rachel; Peyton, Dara; Healy, Mark G; Fenton, Owen; Cummins, Enda

    2017-05-01

    In Ireland, the land application of biosolids is the preferred option of disposing of municipal sewage waste. Biosolids provide nutrients in the form of nitrogen, phosphorus, potassium and increases organic matter. It is also an economic way for a country to dispose of its municipal waste. However, biosolids may potentially contain a wide range of pathogens, and following rainfall events, may be transported in surface runoff and pose a potential risk to human health. Thus, a quantitative risk assessment model was developed to estimate potential pathogens in surface water and the environmental fate of the pathogens following dilution, residence time in a stream, die-off rate, drinking water treatment and human exposure. Surface runoff water quality data was provided by project partners. Three types of biosolids, anaerobically digested (AD), lime stabilised (LS), and thermally dried (TD)) were applied on micro plots. Rainfall was simulated at three time intervals (24, 48 and 360 h) following land application. It was assumed that this water entered a nearby stream and was directly abstracted for drinking water. Consumption data for drinking water and body weight was obtained from an Irish study and assigned distributions. Two dose response models for probability of illness were considered for total and faecal coliform exposure incorporating two different exposure scenarios (healthy populations and immuno-compromised populations). The simulated annual risk of illness for healthy populations was below the US EPA and World Health Organisation tolerable level of risk (10 -4 and 10 -6 , respectively). However, immuno-compromised populations may still be at risk as levels were greater than the tolerable level of risk for that subpopulation. The sensitivity analysis highlighted the importance of residence time in a stream on the bacterial die-off rate. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. The power of runoff

    Science.gov (United States)

    Wörman, A.; Lindström, G.; Riml, J.

    2017-05-01

    Although the potential energy of surface water is a small part of Earth's energy budget, this highly variable physical property is a key component in the terrestrial hydrologic cycle empowering geomorphological and hydrological processes throughout the hydrosphere. By downscaling of the daily hydrometeorological data acquired in Sweden over the last half-century this study quantifies the spatial and temporal distribution of the dominating energy components in terrestrial hydrology, including the frictional resistance in surface water and groundwater as well as hydropower. The energy consumed in groundwater circulation was found to be 34.6 TWh/y or a heat production of approximately 13% of the geothermal heat flux. Significant climate driven, periodic fluctuations in the power of runoff, stream flows and groundwater circulation were revealed that have not previously been documented. We found that the runoff power ranged from 173 to 260 TWh/y even when averaged over the entire surface of Sweden in a five-year moving window. We separated short-term fluctuations in runoff due to precipitation filtered through the watershed from longer-term seasonal and climate driven modes. Strong climate driven correlations between the power of runoff and climate indices, wind and solar intensity were found over periods of 3.6 and 8 years. The high covariance that we found between the potential energy of surface water and wind energy implies significant challenges for the combination of these renewable energy sources.

  1. Continuous state-space representation of a bucket-type rainfall-runoff model: a case study with the GR4 model using state-space GR4 (version 1.0)

    Science.gov (United States)

    Santos, Léonard; Thirel, Guillaume; Perrin, Charles

    2018-04-01

    In many conceptual rainfall-runoff models, the water balance differential equations are not explicitly formulated. These differential equations are solved sequentially by splitting the equations into terms that can be solved analytically with a technique called operator splitting. As a result, only the solutions of the split equations are used to present the different models. This article provides a methodology to make the governing water balance equations of a bucket-type rainfall-runoff model explicit and to solve them continuously. This is done by setting up a comprehensive state-space representation of the model. By representing it in this way, the operator splitting, which makes the structural analysis of the model more complex, could be removed. In this state-space representation, the lag functions (unit hydrographs), which are frequent in rainfall-runoff models and make the resolution of the representation difficult, are first replaced by a so-called Nash cascade and then solved with a robust numerical integration technique. To illustrate this methodology, the GR4J model is taken as an example. The substitution of the unit hydrographs with a Nash cascade, even if it modifies the model behaviour when solved using operator splitting, does not modify it when the state-space representation is solved using an implicit integration technique. Indeed, the flow time series simulated by the new representation of the model are very similar to those simulated by the classic model. The use of a robust numerical technique that approximates a continuous-time model also improves the lag parameter consistency across time steps and provides a more time-consistent model with time-independent parameters.

  2. Microstructure Modeling of Third Generation Disk Alloys

    Science.gov (United States)

    Jou, Herng-Jeng

    2010-01-01

    The objective of this program was to model, validate, and predict the precipitation microstructure evolution, using PrecipiCalc (QuesTek Innovations LLC) software, for 3rd generation Ni-based gas turbine disc superalloys during processing and service, with a set of logical and consistent experiments and characterizations. Furthermore, within this program, the originally research-oriented microstructure simulation tool was to be further improved and implemented to be a useful and user-friendly engineering tool. In this report, the key accomplishments achieved during the third year (2009) of the program are summarized. The activities of this year included: Further development of multistep precipitation simulation framework for gamma prime microstructure evolution during heat treatment; Calibration and validation of gamma prime microstructure modeling with supersolvus heat treated LSHR; Modeling of the microstructure evolution of the minor phases, particularly carbides, during isothermal aging, representing the long term microstructure stability during thermal exposure; and the implementation of software tools. During the research and development efforts to extend the precipitation microstructure modeling and prediction capability in this 3-year program, we identified a hurdle, related to slow gamma prime coarsening rate, with no satisfactory scientific explanation currently available. It is desirable to raise this issue to the Ni-based superalloys research community, with hope that in future there will be a mechanistic understanding and physics-based treatment to overcome the hurdle. In the mean time, an empirical correction factor was developed in this modeling effort to capture the experimental observations.

  3. Joint variability of global runoff and global sea surface temperatures

    Science.gov (United States)

    McCabe, G.J.; Wolock, D.M.

    2008-01-01

    Global land surface runoff and sea surface temperatures (SST) are analyzed to identify the primary modes of variability of these hydroclimatic data for the period 1905-2002. A monthly water-balance model first is used with global monthly temperature and precipitation data to compute time series of annual gridded runoff for the analysis period. The annual runoff time series data are combined with gridded annual sea surface temperature data, and the combined dataset is subjected to a principal components analysis (PCA) to identify the primary modes of variability. The first three components from the PCA explain 29% of the total variability in the combined runoff/SST dataset. The first component explains 15% of the total variance and primarily represents long-term trends in the data. The long-term trends in SSTs are evident as warming in all of the oceans. The associated long-term trends in runoff suggest increasing flows for parts of North America, South America, Eurasia, and Australia; decreasing runoff is most notable in western Africa. The second principal component explains 9% of the total variance and reflects variability of the El Ni??o-Southern Oscillation (ENSO) and its associated influence on global annual runoff patterns. The third component explains 5% of the total variance and indicates a response of global annual runoff to variability in North Aflantic SSTs. The association between runoff and North Atlantic SSTs may explain an apparent steplike change in runoff that occurred around 1970 for a number of continental regions.

  4. Simulation of green roof runoff under different substrate depths and vegetation covers by coupling a simple conceptual and a physically based hydrological model.

    Science.gov (United States)

    Soulis, Konstantinos X; Valiantzas, John D; Ntoulas, Nikolaos; Kargas, George; Nektarios, Panayiotis A

    2017-09-15

    In spite of the well-known green roof benefits, their widespread adoption in the management practices of urban drainage systems requires the use of adequate analytical and modelling tools. In the current study, green roof runoff modeling was accomplished by developing, testing, and jointly using a simple conceptual model and a physically based numerical simulation model utilizing HYDRUS-1D software. The use of such an approach combines the advantages of the conceptual model, namely simplicity, low computational requirements, and ability to be easily integrated in decision support tools with the capacity of the physically based simulation model to be easily transferred in conditions and locations other than those used for calibrating and validating it. The proposed approach was evaluated with an experimental dataset that included various green roof covers (either succulent plants - Sedum sediforme, or xerophytic plants - Origanum onites, or bare substrate without any vegetation) and two substrate depths (either 8 cm or 16 cm). Both the physically based and the conceptual models matched very closely the observed hydrographs. In general, the conceptual model performed better than the physically based simulation model but the overall performance of both models was sufficient in most cases as it is revealed by the Nash-Sutcliffe Efficiency index which was generally greater than 0.70. Finally, it was showcased how a physically based and a simple conceptual model can be jointly used to allow the use of the simple conceptual model for a wider set of conditions than the available experimental data and in order to support green roof design. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. A multi-source data assimilation framework for flood forecasting: Accounting for runoff routing lags

    Science.gov (United States)

    Meng, S.; Xie, X.

    2015-12-01

    In the flood forecasting practice, model performance is usually degraded due to various sources of uncertainties, including the uncertainties from input data, model parameters, model structures and output observations. Data assimilation is a useful methodology to reduce uncertainties in flood forecasting. For the short-term flood forecasting, an accurate estimation of initial soil moisture condition will improve the forecasting performance. Considering the time delay of runoff routing is another important effect for the forecasting performance. Moreover, the observation data of hydrological variables (including ground observations and satellite observations) are becoming easily available. The reliability of the short-term flood forecasting could be improved by assimilating multi-source data. The objective of this study is to develop a multi-source data assimilation framework for real-time flood forecasting. In this data assimilation framework, the first step is assimilating the up-layer soil moisture observations to update model state and generated runoff based on the ensemble Kalman filter (EnKF) method, and the second step is assimilating discharge observations to update model state and runoff within a fixed time window based on the ensemble Kalman smoother (EnKS) method. This smoothing technique is adopted to account for the runoff routing lag. Using such assimilation framework of the soil moisture and discharge observations is expected to improve the flood forecasting. In order to distinguish the effectiveness of this dual-step assimilation framework, we designed a dual-EnKF algorithm in which the observed soil moisture and discharge are assimilated separately without accounting for the runoff routing lag. The results show that the multi-source data assimilation framework can effectively improve flood forecasting, especially when the runoff routing has a distinct time lag. Thus, this new data assimilation framework holds a great potential in operational flood

  6. Global Adjoint Tomography: Next-Generation Models

    Science.gov (United States)

    Bozdag, Ebru; Lefebvre, Matthieu; Lei, Wenjie; Orsvuran, Ridvan; Peter, Daniel; Ruan, Youyi; Smith, James; Komatitsch, Dimitri; Tromp, Jeroen

    2017-04-01

    The first-generation global adjoint tomography model GLAD-M15 (Bozdag et al. 2016) is the result of 15 conjugate-gradient iterations based on GPU-accelerated spectral-element simulations of 3D wave propagation and Fréchet kernels. For simplicity, GLAD-M15 was constructed as an elastic model with transverse isotropy confined to the upper mantle. However, Earth's mantle and crust show significant evidence of anisotropy as a result of its composition and deformation. There may be different sources of seismic anisotropy affecting both body and surface waves. As a first attempt, we initially tackle with surface-wave anisotropy and proceed iterations using the same 253 earthquake data set used in GLAD-M15 with an emphasize on upper-mantle. Furthermore, we explore new misfits, such as double-difference measurements (Yuan et al. 2016), to better deal with the possible artifacts of the uneven distribution of seismic stations globally and minimize source uncertainties in structural inversions. We will present our observations with the initial results of azimuthally anisotropic inversions and also discuss the next generation global models with various parametrizations. Meanwhile our goal is to use all available seismic data in imaging. This however requires a solid framework to perform iterative adjoint tomography workflows with big data on supercomputers. We will talk about developments in adjoint tomography workflow from the need of defining new seismic and computational data formats (e.g., ASDF by Krischer et al. 2016, ADIOS by Liu et al. 2011) to developing new pre- and post-processing tools together with experimenting workflow management tools, such as Pegasus (Deelman et al. 2015). All our simulations are performed on Oak Ridge National Laboratory's Cray XK7 "Titan" system. Our ultimate aim is to get ready to harness ORNL's next-generation supercomputer "Summit", an IBM with Power-9 CPUs and NVIDIA Volta GPU accelerators, to be ready by 2018 which will enable us to

  7. Sensitivity Analysis and Calibration of a Rainfall-Runoff Model with the Combined Use of EPA-SWMM and Genetic Algorithm

    Science.gov (United States)

    Del Giudice, Giuseppe; Padulano, Roberta

    2016-10-01

    An integrated Visual Basic Application interface is described that allows for sensitivity analysis, calibration and routing of hydraulichydrological models. The routine consists in the combination of three freeware tools performing hydrological modelling, hydraulic modelling and calibration. With such an approach, calibration is made possible even if information about sewers geometrical features is incomplete. Model parameters involve storage coefficient, time of concentration, runoff coefficient, initial abstraction and Manning coefficient; literature formulas are considered and manipulated to obtain novel expressions and variation ranges. A sensitivity analysis with a local method is performed to obtain information about collinearity among parameters and a ranking of influence. The least important parameters are given a fixed value, and for the remaining ones calibration is performed by means of a genetic algorithm implemented in GANetXL. Single-event calibration is performed with a selection of six rainfall events, which are chosen so to avoid non-uniform rainfall distribution; results are then successfully validated with a sequence of four events.

  8. Global adjoint tomography: first-generation model

    KAUST Repository

    Bozdağ, Ebru

    2016-09-23

    We present the first-generation global tomographic model constructed based on adjoint tomography, an iterative full-waveform inversion technique. Synthetic seismograms were calculated using GPU-accelerated spectral-element simulations of global seismic wave propagation, accommodating effects due to 3-D anelastic crust & mantle structure, topography & bathymetry, the ocean load, ellipticity, rotation, and self-gravitation. Fréchet derivatives were calculated in 3-D anelastic models based on an adjoint-state method. The simulations were performed on the Cray XK7 named \\'Titan\\', a computer with 18 688 GPU accelerators housed at Oak Ridge National Laboratory. The transversely isotropic global model is the result of 15 tomographic iterations, which systematically reduced differences between observed and simulated three-component seismograms. Our starting model combined 3-D mantle model S362ANI with 3-D crustal model Crust2.0. We simultaneously inverted for structure in the crust and mantle, thereby eliminating the need for widely used \\'crustal corrections\\'. We used data from 253 earthquakes in the magnitude range 5.8 ≤ M ≤ 7.0. We started inversions by combining ~30 s body-wave data with ~60 s surface-wave data. The shortest period of the surface waves was gradually decreased, and in the last three iterations we combined ~17 s body waves with ~45 s surface waves. We started using 180 min long seismograms after the 12th iteration and assimilated minor- and major-arc body and surface waves. The 15th iteration model features enhancements of well-known slabs, an enhanced image of the Samoa/Tahiti plume, as well as various other plumes and hotspots, such as Caroline, Galapagos, Yellowstone and Erebus. Furthermore, we see clear improvements in slab resolution along the Hellenic and Japan Arcs, as well as subduction along the East of Scotia Plate, which does not exist in the starting model. Point-spread function tests demonstrate that we are approaching the

  9. Modeling and Generating Strategy Games Mechanics

    DEFF Research Database (Denmark)

    Mahlmann, Tobias

    Strategy games are a popular genre of games with a long history, originating from games like Chess or Go. The first strategy games were published as “Kriegspiele” (engl. wargames) in the late 18th century, intended for the education of young cadets. Since then strategy games were refined...... and transformed over two centuries into a medium of entertainment. Today’s computer strategy games have their roots in the board- and roleplaying games of the 20th century and enjoy great popularity. We use strategy games as an application for the procedural generation of game content. Procedural game content...... of the game is, how players may manipulate the game world, etc. We present the Strategy Games Description Language (SGDL), a tree-based approach to model the game mechanics of strategy games. SGDL allows game designers to rapid prototype their game ideas with the help of our customisable game engine. We...

  10. Towards an improved understanding of hillslope runoff as a supply for groundwater recharge: Assessing hillslope runoff under regional deforestation and varying climate conditions in a drainage basin in central coastal California

    Science.gov (United States)

    Young, K. S.; Beganskas, S.; Fisher, A. T.

    2017-12-01

    We use a hydrologic model to analyze hillslope runoff under a range of climate and land use conditions in the San Lorenzo River Basin (SLRB), central coastal California, including contemporary land use and incremental deforestation. The SLRB is a heavily forested watershed with chronically overdrafted aquifers; in some areas, groundwater levels have been lowered by >50 m in recent decades. Managed aquifer recharge (MAR) can help mitigate declines in groundwater storage, routing excess surface flows to locations where they can infiltrate. We are especially interested in opportunities for collection of stormwater runoff, particularly where development and other changes in landuse have increased hill slope runoff. To assess hillslope runoff at the subwatershed scale (10-100 ha; 25-250 ac), we apply the Precipitation Runoff Modeling System (PRMS) to a high-resolution, digital elevation model and populate the simulation with area- and density-weighted vegetation and soil parameters calculated from high resolution input data. We also develop and apply a catalog of dry, normal, and wet climate scenarios from the historic record (1981-2014). In addition, we simulate conditions ranging from 0 to 100 percent of redwoods harvested (representing the mid-1800s to 1930s logging era) using a historical land use data set to alter soil and vegetation conditions. Results under contemporary land use suggest there are ample opportunities to establish MAR projects during all climate scenarios; hill slope runoff generation is spatially variable and on average exceeds 23,000 ac-ft/yr (3.2 in/yr) during the driest climate scenario. Preliminary results from the deforestation scenarios show notable increases in hillslope runoff with progressive redwood harvesting. Relative to pre-logging conditions, between 1.1 in (dry climates) and 1.5 in (wet climates) more runoff is generated under contemporary conditions, with most of the runoff increase occurring in urban areas. These modeling methods

  11. GSFLOW - Coupled Ground-Water and Surface-Water Flow Model Based on the Integration of the Precipitation-Runoff Modeling System (PRMS) and the Modular Ground-Water Flow Model (MODFLOW-2005)

    Science.gov (United States)

    Markstrom, Steven L.; Niswonger, Richard G.; Regan, R. Steven; Prudic, David E.; Barlow, Paul M.

    2008-01-01

    The need to assess the effects of variability in climate, biota, geology, and human activities on water availability and flow requires the development of models that couple two or more components of the hydrologic cycle. An integrated hydrologic model called GSFLOW (Ground-water and Surface-water FLOW) was developed to simulate coupled ground-water and surface-water resources. The new model is based on the integration of the U.S. Geological Survey Precipitation-Runoff Modeling System (PRMS) and the U.S. Geological Survey Modular Ground-Water Flow Model (MODFLOW). Additional model components were developed, and existing components were modified, to facilitate integration of the models. Methods were developed to route flow among the PRMS Hydrologic Response Units (HRUs) and between the HRUs and the MODFLOW finite-difference cells. This report describes the organization, concepts, design, and mathematical formulation of all GSFLOW model components. An important aspect of the integrated model design is its ability to conserve water mass and to provide comprehensive water budgets for a location of interest. This report includes descriptions of how water budgets are calculated for the integrated model and for individual model components. GSFLOW provides a robust modeling system for simulating flow through the hydrologic cycle, while allowing for future enhancements to incorporate other simulation techniques.

  12. A modeling approach to evaluate the impact of conservation practices on runoff and sediments in Sasumua watershed, Kenya

    Science.gov (United States)

    Degradation of agricultural watersheds often reduces their capacity to provide vital environmental services such as food production, clean potable water, water bodies for recreation and generation of hydro-electric power. Soil and water conservation practices on agricultural lands can enhance the ca...

  13. Hydrology in a mediterranean mountain environment. The Vallcebre research catchment (north eastern Spain) II. Rainfall-runoff relationships and runoff processes; Hidrologia de un ambiente Mediterraneo de montana. Las cuencas de Vallcebre (Pirineo Oriental) II. Relaciones precipitacion-escorrentia y procesos hidrologicos

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  14. Phytoremediation of agriculture runoff by filamentous algae poly-culture for biomethane production, and nutrient recovery for secondary cultivation of lipid generating microalgae.

    Science.gov (United States)

    Bohutskyi, Pavlo; Chow, Steven; Ketter, Ben; Fung Shek, Coral; Yacar, Dean; Tang, Yuting; Zivojnovich, Mark; Betenbaugh, Michael J; Bouwer, Edward J

    2016-12-01

    An integrated system was implemented for water phytoremediation and biofuel production through sequential cultivation of filamentous algae followed by cultivation of lipid-producing microalgae Chlorella sorokiniana. Natural poly-culture of filamentous algae was grown in agricultural stormwater using the Algal Turf Scrubber®, harvested and subjected for lipid extraction and/or methane production using anaerobic digestion (AD). While filamentous algae lipid content was too low for feasible biodiesel production (filamentous algae poly-culture was exploited for waste nutrient capturing and biofuel feedstock generation. These nutrients were recovered and reused as a concentrated supplement for potentially high-value microalgae. Published by Elsevier Ltd.

  15. Total pollution effect of urban surface runoff.

    Science.gov (United States)

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

    2009-01-01

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

  16. The role of basin physical property data in assessing water stress in water resources studies: The application of the Pitman Rainfall-runoff model in Nigeria

    CSIR Research Space (South Africa)

    Ayeni, AO

    2012-11-01

    Full Text Available This paper examines the role played by basin physical attributes in determining river runoff. The approach uses soil and other available hydro-meteorological and geophysical information to directly estimate the parameters of the Pitman rainfall...

  17. "Method, system and storage medium for generating virtual brick models"

    DEFF Research Database (Denmark)

    2009-01-01

    An exemplary embodiment is a method for generating a virtual brick model. The virtual brick models are generated by users and uploaded to a centralized host system. Users can build virtual models themselves or download and edit another user's virtual brick models while retaining the identity...... of the original virtual brick model. Routines are provided for both storing user created building steps in and generating automated building instructions for virtual brick models, generating a bill of materials for a virtual brick model and ordering physical bricks corresponding to a virtual brick model....

  18. Riverine tot-P loading and seawater concentrations in the Baltic Sea during the 1970s to 2000-transfer function modelling based on the total runoff.

    Science.gov (United States)

    Hänninen, Jari; Vuorinen, Ilppo

    2015-06-01

    The signal of climate through the North Atlantic Oscillation (NAO) extends to westerly weather and to the Baltic Sea river runoff (BSRR) and further to the salinity and the marine fauna in the Baltic Sea. Our working hypothesis was that increased BSRR should also lead to increasing nutrient concentrations in the seawater. In rivers, transfer function (TF) models of the loading were constructed by time series of BSRR and tot-P concentrations. Based on the loading time series, we modelled, to our knowledge, first time, seawater tot-P concentrations in both the Northern Baltic Proper and in the Gulf of Bothnia, both on the surface (0-20 m) and deeper (21-70 m) waters. Our results further suggest a unifying mechanism by the BSRR that could explain most prominent ecological changes observed in the Baltic Sea during and after the 1970s. Such changes are eutrophication (as in this paper) and decreasing salinity and growth and reproduction of marine fauna, all of which have been separately described as due to different causes. BSRR is crucial when possible future developments of the Baltic Sea environment are considered because a general opinion exists that the rainfall (and the BSRR) is expected to increase in pace with proceeding climate change.

  19. Estimation of groundwater recharge via percolation outputs from a rainfall/runoff model for the Verlorenvlei estuarine system, west coast, South Africa

    Science.gov (United States)

    Watson, Andrew; Miller, Jodie; Fleischer, Melanie; de Clercq, Willem

    2018-03-01

    Wetlands are conservation priorities worldwide, due to their high biodiversity and productivity, but are under threat from agricultural and climate change stresses. To improve the water management practices and resource allocation in these complex systems, a modelling approach has been developed to estimate potential recharge for data poor catchments using rainfall data and basic assumptions regarding soil and aquifer properties. The Verlorenvlei estuarine lake (RAMSAR #525) on the west coast of South Africa is a data poor catchment where rainfall records have been supplemented with farmer's rainfall records. The catchment has multiple competing users. To determine the ecological reserve for the wetlands, the spatial and temporal distribution of recharge had to be well constrained using the J2000 rainfall/runoff model. The majority of rainfall occurs in the mountains (±650 mm/yr) and considerably less in the valley (±280 mm/yr). Percolation was modelled as ∼3.6% of rainfall in the driest parts of the catchment, ∼10% of rainfall in the moderately wet parts of the catchment and ∼8.4% but up to 28.9% of rainfall in the wettest parts of the catchment. The model results are representative of rainfall and water level measurements in the catchment, and compare well with water table fluctuation technique, although estimates are dissimilar to previous estimates within the catchment. This is most likely due to the daily timestep nature of the model, in comparison to other yearly average methods. These results go some way in understanding the fact that although most semi-arid catchments have very low yearly recharge estimates, they are still capable of sustaining high biodiversity levels. This demonstrates the importance of incorporating shorter term recharge event modeling for improving recharge estimates.

  20. Application of the Precipitation-Runoff Modeling System (PRMS) in the Apalachicola-Chattahoochee-Flint River Basin in the southeastern United States

    Science.gov (United States)

    LaFontaine, Jacob H.; Hay, Lauren E.; Viger, Roland J.; Markstrom, Steve L.; Regan, R. Steve; Elliott, Caroline M.; Jones, John W.

    2013-01-01

    A hydrologic model of the Apalachicola–Chattahoochee–Flint River Basin (ACFB) has been developed as part of a U.S. Geological Survey (USGS) National Climate Change and Wildlife Science Center effort to provide integrated science that helps resource managers understand the effect of climate change on a range of ecosystem responses. The hydrologic model was developed as part of the Southeast Regional Assessment Project using the Precipitation Runoff Modeling System (PRMS), a deterministic, distributed-parameter, process-based system that simulates the effects of precipitation, temperature, and land use on basin hydrology. The ACFB PRMS model simulates streamflow throughout the approximately 50,700 square-kilometer basin on a daily time step for the period 1950–99 using gridded climate forcings of air temperature and precipitation, and parameters derived from spatial data layers of altitude, land cover, soils, surficial geology, depression storage (small water bodies), and data from 56 USGS streamgages. Measured streamflow data from 35 of the 56 USGS streamgages were used to calibrate and evaluate simulated basin streamflow; the remaining gage locations were used for model delineation only. The model matched measured daily streamflow at 31 of the 35 calibration gages with Nash-Sutcliffe Model Efficiency Index (NS) greater than 0.6. Streamflow data for some calibration gages were augmented for regulation and water use effects to represent more natural flow volumes. Time-static parameters describing land cover limited the ability of the simulation to match historical runoff in the more developed subbasins. Overall, the PRMS simulation of the ACFB provides a good representation of basin hydrology on annual and monthly time steps. Calibration subbasins were analyzed by separating the 35 subbasins into five classes based on physiography, land use, and stream type (tributary or mainstem). The lowest NS values were rarely below 0.6, whereas the median NS for all five

  1. Runoff Analysis Considering Orographical Features Using Dual Polarization Radar Rainfall

    Science.gov (United States)

    Noh, Hui-seong; Shin, Hyun-seok; Kang, Na-rae; Lee, Choong-Ke; Kim, Hung-soo

    2013-04-01

    Recently, the necessity for rainfall estimation and forecasting using the radar is being highlighted, due to the frequent occurrence of torrential rainfall resulting from abnormal changes of weather. Radar rainfall data represents temporal and spatial distributions properly and replace the existing rain gauge networks. It is also frequently applied in many hydrologic field researches. However, the radar rainfall data has an accuracy limitation since it estimates rainfall, by monitoring clouds and precipitation particles formed around the surface of the earth(1.5-3km above the surface) or the atmosphere. In a condition like Korea where nearly 70% of the land is covered by mountainous areas, there are lots of restrictions to use rainfall radar, because of the occurrence of beam blocking areas by topography. This study is aiming at analyzing runoff and examining the applicability of (R(Z), R(ZDR) and R(KDP)) provided by the Han River Flood Control Office(HRFCO) based on the basin elevation of Nakdong river watershed. For this purpose, the amount of radar rainfall of each rainfall event was estimated according to three sub-basins of Nakdong river watershed with the average basin elevation above 400m which are Namgang dam, Andong dam and Hapcheon dam and also another three sub-basins with the average basin elevation below 150m which are Waegwan, Changryeong and Goryeong. After runoff analysis using a distribution model, Vflo model, the results were reviewed and compared with the observed runoff. This study estimated the rainfall by using the radar-rainfall transform formulas, (R(Z), R(Z,ZDR) and R(Z,ZDR,KDP) for four stormwater events and compared the results with the point rainfall of the rain gauge. As the result, it was overestimated or underestimated, depending on rainfall events. Also, calculation indicates that the values from R(Z,ZDR) and R(Z,ZDR,KDP) relatively showed the most similar results. Moreover the runoff analysis using the estimated radar rainfall is

  2. Application of SWAT Model to Estimate the Runoff and Sediment Load from the Right Bank Valleys of Mosul Dam Reservoir

    OpenAIRE

    Ezz-Aldeen, Mohammad; Al-Ansari, Nadhir; Knutsson, Sven

    2012-01-01

    Mosul Dam is the biggest hydraulic structure on the River Tigris in Iraq with 11.11 billion m3 storage capacity. The dam is a multipurpose project. It is used to store the water for irrigation, hydropower generation, and flood control. As in other dams in the world, this dam also have sedimentation problem. Sediment accumulation in its reservoir can effect the dam operation (pumping station, hydropower plants, and bottom outlets) and it will definitely shorten the life span of the dam. In thi...

  3. Model Based Analysis and Test Generation for Flight Software

    Science.gov (United States)

    Pasareanu, Corina S.; Schumann, Johann M.; Mehlitz, Peter C.; Lowry, Mike R.; Karsai, Gabor; Nine, Harmon; Neema, Sandeep

    2009-01-01

    We describe a framework for model-based analysis and test case generation in the context of a heterogeneous model-based development paradigm that uses and combines Math- Works and UML 2.0 models and the associated code generation tools. This paradigm poses novel challenges to analysis and test case generation that, to the best of our knowledge, have not been addressed before. The framework is based on a common intermediate representation for different modeling formalisms and leverages and extends model checking and symbolic execution tools for model analysis and test case generation, respectively. We discuss the application of our framework to software models for a NASA flight mission.

  4. New tools for generation IV assemblies modelling

    International Nuclear Information System (INIS)

    Sylvie Aniel-Buchheit; Edwige Richebois

    2005-01-01

    Full text of publication follows: In the framework of the development of generation IV concepts, the need of new assembly modelling tools arises. These concepts present more geometrical and spectral heterogeneities (radially and axially). Moreover thermal-hydraulics and neutronics aspects are so closely related that coupled computations are necessary. That raises the need for more precise and flexible tools presenting 3D features. The 3D-coupling of the thermal-hydraulic code FLICA4 with the Monte-Carlo neutronics code TRIPOLI4 was developed in that frame. This new tool enables for the first time to obtain realistic axial and radial power profiles with real feedback effects in an assembly where thermal-hydraulics and neutronics effects are closely related. The BWR is the existing concept presenting the closest heterogeneous characteristics to the various new proposed concepts. This assembly design is thus chosen to compare this new tool, presenting real 3D characteristics, to the existing ones. For design studies, the evaluation of the assembly behavior, currently necessitate a depletion scheme using a 3D thermal-hydraulics assembly calculation coupled with a 1D axial neutronics deterministic calculation (or an axial power profile chosen as a function of the assembly averaged burn-up). The 3D neutronics code (CRONOS2) uses neutronic data built by 2D deterministic assembly calculations without feedback. These cross section libraries enable to take feedbacks into account via parameters such as fuel temperature, moderator density and temperature (history parameters such as void and control rod are not useful in design evaluation). Recently, the libraries build-up has been replaced by on line multi-2D deterministic assembly calculations performed by a cell code (APOLLO2). That avoids interpolation between pre-determined parameters in the cross-section data used by the 1D axial neutronics calculation and enable to give a radial power map to the 3D thermal

  5. 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...

  6. Assessment of evapotranspiration and soil water content in the Kysuca River basin (Slovakia) using a rainfall-runoff model

    Czech Academy of Sciences Publication Activity Database

    Košková, Romana; Němečková, Soňa; Sitková, Z.

    2008-01-01

    Roč. 4, č. 1 (2008), s. 012002 ISSN 1755-1315. [Conference of the Danubian Countries /24./. Bled, 02.06.2008-04.06.2008] R&D Projects: GA AV ČR(CZ) KJB300600602 Institutional research plan: CEZ:AV0Z20600510 Keywords : hydrological modelling * soil water content * evapotranspiration * SWIM model Subject RIV: DA - Hydrology ; Limnology http://www.iop.org/EJ/abstract/1755-1315/4/1/012002

  7. Predictions of rainfall-runoff response and soil moisture dynamics in a microscale catchment using the CREW model

    Directory of Open Access Journals (Sweden)

    H. Lee

    2007-01-01

    Full Text Available Predictions of catchment hydrology have been performed generally using either physically based, distributed models or conceptual lumped or semi-distributed models. In recognition of the disadvantages of using either of these modeling approaches, namely, detailed data requirements in the case of distributed modeling, and lack of physical basis of conceptual/lumped model parameters, Reggiani et al. (1998, 1999 derived, from first principles and in a general manner, the balance equations for mass, momentum and energy at what they called the Representative Elementary Watershed (or REW scale. However, the mass balance equations of the REW approach include mass exchange flux terms which must be defined externally before their application to real catchments. Developing physically reasonable "closure relations" for these mass exchange flux terms is a crucial pre-requisite for the success of the REW approach. As a guidance to the development of closure relations expressing mass exchange fluxes as functions of relevant state variables in a physically reasonable way, and in the process effectively parameterizing the effects of sub-grid or sub-REW heterogeneity of catchment physiographic properties on these mass exchange fluxes, this paper considers four different approaches, namely the field experimental approach, a theoretical/analytical approach, a numerical approach, and a hybrid approach combining one or more of the above. Based on the concept of the scaleway (Vogel and Roth, 2003 and the disaggregation-aggregation approach (Viney and Sivapalan, 2004, and using the data set from Weiherbach catchment in Germany, closure relations for infiltration, exfiltration and groundwater recharge were derived analytically, or on theoretical grounds, while numerical experiments with a detailed fine-scale, distributed model, CATFLOW, were used to obtain the closure relationship for seepage outflow. The detailed model, CATFLOW, was also used to derive REW scale

  8. Evaluation of Livestock Runoff as a Source of Water Polution in Northern Utah

    OpenAIRE

    Wieneke, Stephen T.; George, Dennis B.; Filip, Daniel S.; Finney, Brad

    1980-01-01

    A mathematical model was developed to predict the impact of dairy and beef cattle feedlot runoff on receiving streams. The mathematical expressions used in the model describing runoff quantity and quality were not only a function of single rain or snow precipitation events but also consecutive events prior to the runoff occurrence. The runoff quantity and quality were also a function of feedlot surface. Computer s...

  9. 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.

  10. As