Sample records for hydrological model hbv

  1. Testing of a coupled model of the HBV model and a glacier retreat model on a Himalayan basin

    NASA Astrophysics Data System (ADS)

    LI, Hong; Xu, Chongyu; Beldring, Stein; Melvold, Kjetil; Jain, Sharad

    2014-05-01

    The Himalayan glaciers are source of numerous large Asian river systems, including the Indus, Ganges, and Brahmaputra, which provide water for 1.5 billion people. This region is among areas that are the most sensitive to climate change. Shrinking of the glaciers is expected to significantly affect hydrologic responses of glaciated basins. Retreat of glaciers in these basins is predicted to cause severe water crisis in these basins. However, glacier behaviours are not well represented in most current hydrological models. The objective of the present study is to test performance of a coupled model consisting of a hydrological model and a glacier retreat model. The hydrological model is a distributed HBV model, simulating runoff response to water input into catchment. The glacier retreat model is a distributed glacier-specific model, ?h-parameterization describing ice redistribution caused by glacier movement. The Beas River basin in the Northern India is selected as focus area because of its high representativeness of the Himalayan basins and availability of data. This study will not only improve the HBV model for hydrological studies in glaciated catchments, but also contribute to improved understanding and modelling of glacier hydrology. The coupled model will be a useful tool for water resources projections and hydropower planning in a far future on highly glaciated basins.

  2. Mathematical Modeling of Dynamic Host Responses to HBV Infection

    Microsoft Academic Search

    Changjiang Long; Huan Qi; Sheng-he Huang

    2007-01-01

    Nowak's model of the human immunodeficiency virus (HIV) infection has been extensively and successfully used to simulate the interaction between HIV and cytotoxic lymphocyte (CTL)-mediated immune response. However, such model is not available for hepatitis B virus (HBV). As the enhanced recruitment of virus-specific CTLs into the liver has been an important novel concept in the pathogenesis of hepatitis B,

  3. Forecasting river discharge using coupled WRF-NMM meteorological model and HBV runoff model, case studies

    NASA Astrophysics Data System (ADS)

    Deki?, L.; Mihalovi?, A.; Jovi?i?, I.; Vladikovi?, D.; Jerini?, J.; Ivkovi?, M.

    2012-04-01

    This paper examines two episodes of heavy rainfall and significantly increased water levels. The first case relates to the period including the beginning and the end of the third decade of June 2010 at the Kolubara river basin, where extreme rainfall led to two big flood waves on the Kolubara river, whereat water levels exceeded both regular and extraordinary flood defence and approached their historical maximum. The second case relates to the period including the end of November and the beginning of December 2010 at the Jadar river basin, where heavier precipitation caused the water levels of the basin to reach and surpass the occurrence limit (warning level). The HBV (Hydrological Bureau Waterbalance-section) rainfall/snowmelt - runoff model installed at the RHMSS uses gridded quantitative precipitation and air temperature forecast for 72 hours in advance based on meteorological weather forecast WRF-NMM mesoscale model. Nonhydrostatic Mesoscale Model (NMM) core of the Weather Research and Forecasting (WRF) system is flexible state-of-the-art numerical weather prediction model capable to describe and estimate powerful nonhydrostatic mechanism in convective clouds that cause heavy rain. The HBV model is a semi-distributed conceptual catchment model in which the spatial structure of a catchment area is not explicitly modelled. Instead, the sub-basin represents a primary modelling unit while the basin is characterised by area-elevation distribution and classification of vegetation cover and land use distributed by height zone. WRF-NMM forecast shows very good agreement with observations in terms of timing, location and amount of precipitation. They are used as input for HBV model, forecasted discharges at the output profile of the selected river basin represent model output for consideration. 1 Republic Hydrometeorological Service of Serbia

  4. Assimilating H-SAF and MODIS Snow Cover Data into the Conceptual Models HBV and SRM

    NASA Astrophysics Data System (ADS)

    Sensoy, Aynur; Schwanenberg, Dirk; Sorman, Arda; Akkol, Bulut; Alvarado Montero, Rodolfo; Uysal, Gokcen

    2014-05-01

    Conceptual hydrological models are widely used for operational and scientific water resources management applications in mountain catchments. However, current model-based forecasting approaches are jeopardized by input data and model uncertainties. Data assimilation provides a suitable tool to merge information from remotely sensed observations and hydrological model predictions for improving the lead time performance of streamflow forecasts in the context of operational hydrological forecasting systems. In this study, we present a novel variational approach based on Moving Horizon Estimation (MHE). It includes a highly flexible formulation of distance metrics for penalizing the introduction of noise into the model and enforcing the agreement between simulated and observed variables. Furthermore, the MHE setup shows a high robustness regarding non-equidistant, noisy and sometimes missing data and enables the modification of model input as well as state variables. In situ snowpack measurements are sparsely distributed in mountainous regions. Therefore the data limitations in combination with snowpack heterogeneity prevent a detailed understanding of the variability of snow cover and melt. Remotely sensed images offer an opportunity to supplement ground measurements for performing runoff predictions during the snowmelt season. In this context, EUMETSAT initiated the H-SAF (Satellite Application Facility on Support to Operational Hydrology and Water Management) project for deriving novel products from satellite data and applying it to operational hydrology. This research contributes to the H-SAF product validation by applying a generic data assimilation test bed for H-SAF snow products in comparison to snow cover data of MODIS. A preliminary performance assessment of the data assimilation framework using the conceptual models HBV and SRM with satellite derived snow data is evaluated for a snow dominated test site of 10250 km2 at the headwaters of Euphrates River in Turkey.

  5. Chronic hepatitis B infection and HBV DNA-containing capsids: Modeling and analysis

    NASA Astrophysics Data System (ADS)

    Manna, Kalyan; Chakrabarty, Siddhartha P.

    2015-05-01

    We analyze the dynamics of chronic HBV infection taking into account both uninfected and infected hepatocytes along with the intracellular HBV DNA-containing capsids and the virions. While previous HBV models have included either the uninfected hepatocytes or the intracellular HBV DNA-containing capsids, our model accounts for both these two populations. We prove the conditions for local and global stability of both the uninfected and infected steady states in terms of the basic reproduction number. Further, we incorporate a time lag in the model to encompass the intracellular delay in the production of the infected hepatocytes and find that this delay does not affect the overall dynamics of the system. The results for the model and the delay model are finally numerically illustrated.

  6. A comparison of SRM and HBV models for real time runoff forecasting in the Upper Euphrates Basin, Turkey

    NASA Astrophysics Data System (ADS)

    Sorman, A. A.; Sensoy, A.; Yamankurt, E.; Gozel, E.

    2012-04-01

    Predicting snowmelt runoff in the mountainous eastern part of Turkey at a daily time step is important in water resource management as it constitutes nearly 2/3 in volume of the total yearly runoff during spring and early summer months. Keeping track of snow dynamics as well as forecasting the amount and timing of snowmelt runoff in the headwaters of the trans-boundary Euphrates River, where large dams are located, is a crucial and challenging task concerning the practical importance and great demand for real time forecasting of melt water. In mountainous regions, data limitations prevent detailed understanding of the variability of snow cover and melt. In situ snowpack measurements are sparsely distributed relative to snowpack heterogeneity therefore, to supplement ground measurement networks, remotely sensed images of snow covered area (SCA) provide useful information for runoff prediction during the snowmelt season. SCA has been used as a direct input to hydrological models such as Snowmelt Runoff Model (SRM) or as a means of assimilating hydrologic model snowpack and checking the internal validity as in the case of HBV model. Alternative ways of handling melt water modeling using satellite derived SCA is discussed, with emphasis on the contrasting treatments in two widely used hydrologic models, SRM and HBV. The greatest similarity between the two models is that each uses a temperature index method to predict melt rate whereas the greatest difference lies in the way snow cover is handled. Moderate Resolution Imaging Spectroradiometer (MODIS) daily snow cover products with 500 m spatial resolution are used to derive SCA data in this study. Since the cloud obscuring problem degrades the use of satellites with optical sensors, a special combination and filtering methodology is utilized to reduce cloud coverage of the product. Both models are used to simulate runoff for the years 2001-2010 with model efficiency above 0.86 and volume difference less than 2.5%. Finally, operational snowmelt runoff forecasting is carried out for 2011 ablation season using numerical weather prediction (Mesoscale Model 5) data as forcing input variables. Discussion of results are supervised to reflect the general debates in hydrologic modeling in terms of parameters and calibration, internal validation, the value and limitations of using satellite derived and numerical weather prediction data. Key words: snow, SRM, HBV, forecasting, Upper Euphrates Basin

  7. Thermal-hydrological models

    SciTech Connect

    Buscheck, T., LLNL

    1998-04-29

    This chapter describes the physical processes and natural and engineered system conditions that affect thermal-hydrological (T-H) behavior in the unsaturated zone (UZ) at Yucca Mountain and how these effects are represented in mathematical and numerical models that are used to predict T-H conditions in the near field, altered zone, and engineered barrier system (EBS), and on waste package (WP) surfaces.

  8. Humanized Murine Model for HBV and HCV Using Human Induced Pluripotent Stem Cells

    PubMed Central

    Zhou, Xiao-Ling; Sullivan, Gareth J.; Sun, Pingnan; Park, In-Hyun

    2013-01-01

    Infection of hepatitis B virus (HBV) and hepatitis C virus (HCV) results in heterogeneous outcomes from acute asymptomatic infection to chronic infection leading to cirrhosis and hepatocellular carcinoma (HCC). In vitro models using animal hepatocytes, human HCC cell lines, or in vivo transgenic mouse models have contributed invaluably to understanding the pathogenesis of HBV and HCV. A humanized mouse model made by reconstitution of human primary hepatocytes in the liver of the immunodeficient mouse provides a novel experimental opportunity which mimics the in vivo growth of the human hepatocytes. The limited access to primary human hepatocytes necessitated the search for other cellular sources, such as pluripotent stem cells. Human embryonic stem cells (hESCs) have the features of self-renewal and pluripotency and differentiate into cells of all three germ layers, including hepatocytes. Humaninduced pluripotent stem cells (iPSCs) derived from the patient’s or individual’s own cells provide a novel opportunity to generate hepatocyte-like cells with the defined genetic composition. Here, we will review the current perspective of the models used for HBV and HCV study, and introduce the personalized mouse model using human iPSCs. This novel mouse model will facilitate the direct investigation of HBV and HCV in human hepatocytes as well as probing the genetic influence on the susceptibility of hepatocytes to HBV and HCV. PMID:22370780

  9. Mathematical Modeling of Watershed Hydrology

    Microsoft Academic Search

    Vijay P. Singh

    2002-01-01

    Mathematical modeling of watershed hydrology is employed to address a wide spectrum of environmental and water re- sources problems. A historical perspective of hydrologic modeling is provided, and new developments and challenges in watershed models are discussed. These include data acquisition by remote sensing and space technology, digital terrain and elevation models, chemical tracers, geographic information and data management systems,

  10. A comparison of SRM and HBV models for real time runoff forecasting in the Upper Euphrates Basin, Turkey

    NASA Astrophysics Data System (ADS)

    Sorman, A.; Sensoy, A.; Gozel, E.; Yamankurt, E.; Sorman, U.

    2011-12-01

    Predicting snowmelt runoff in the mountainous eastern part of Turkey at a daily timescale is important in water resource management as it constitutes nearly 2/3 in volume of the total yearly runoff during spring and early summer months. Keeping track of snow dynamics and forecasting the amount and the timing of snowmelt runoff in the headwaters of the trans-boundary Euphrates River, where large dams are located, is a crucial and challenging task concerning the practical importance and great demand for real time forecasting of meltwater. In mountainous regions, data limitations prevent detailed understanding of the variability of snow cover and melt. In situ snowpack measurements are sparsely distributed relative to snowpack heterogeneity therefore to supplement ground measurement networks, remotely derived images of snow covered area (SCA) provides useful information for runoff prediction during the snowmelt season. SCA has been used as a direct input to hydrological models such as Snowmelt Runoff Model (SRM) or as a means of updating hydrologic model snowpack simulations and checking the internal validity of snowmelt runoff model as in the case of HBV model. Alternative ways of handling meltwater modeling using satellite derived SCA is discussed, with emphasis on the contrasting treatments in two widely used models, HBV and SRM. The greatest similarity between two models is that each uses a temperature index method to predict melt rate and the greatest difference between the models is in the way snow cover is handled. Moderate Resolution Imaging Spectroradiometer (MODIS) daily snow cover products with 500 m spatial resolution are used to derive SCA data in this study. Since the cloud obscuring problem degrades the use of satellites with optical sensors, a special combination and filtering methodology is used to reduce cloud coverage of the product. Both models are used to simulate runoff for the years 2003-2010 with model efficiency above 0.85 and volume difference around 2.5% and model parameters are calibrated in these applications. Finally, an operational snowmelt runoff forecasting is carried out for 2011 ablation season using numerical weather prediction Mesoscale Model 5 (MM5) data as forcing input variables. Discussion of results are supervised to reflect the general debates in hydrological modeling in terms of parameters and calibration, internal validation, the value and limitations of using satellite derived data.

  11. Complexity regularized hydrological model selection

    NASA Astrophysics Data System (ADS)

    Arkesteijn, Liselot; Pande, Saket; Savenije, Hubert

    2014-05-01

    Ill-posed hydrological model selection problems (that may be unstable or have non-unique solutions) are regularized with hydrological model complexity as the stabilizer. We propose and apply a notion of model complexity, based on Vapnik-Chervonenkis generalization theory, to complexity regularized hydrologic model selection. Better hydrologic models (better performance on future unseen data) on small sample sizes are identified using complexity regularized model selection than when using traditional model selection (without regularization) while both converge in performance for large samples (i.e. regularized model selection is 'consistent'). Case studies using SAC-SMA, SIXPAR and flexible model structures are used to 1) compute and compare model complexities of different model structures, 2) demonstrate the 'consistency' of complexity regularized model selection and 3) demonstrate that regularized model selection identifies the best model structure (out of a set of competing structures) on small sample sizes better than un-regularized model selection.

  12. Sensitivity Analysis of a Conceptual HBV Ra?nfall-Runoff MODEL Using Eumetsat Snow Covered Area Product

    NASA Astrophysics Data System (ADS)

    Akyurek, Z.; Surer, S.; Parajka, J.

    2014-12-01

    HBV is a conceptual hydrological model extensively used in operational hydrological forecasting and water balance studies. In this study, we apply the HBV model on the upper Euphrates basin in Turkey, which has 10 624 km2 area. The Euphrates basin is largely fed from snow precipitation whereby nearly two-thirds occur in winter and may remain in the form of snow for half of the year. We analyze individual sensitivity of the parameters by calibrating the model using the Multi-Objective Shuffled Complex Evolution (MOSCEM) algorithm. The calibration is performed against snow cover area (SCA) in addition to runoff data for the water years 2009, 2010, 2011, 2012 and 2013. The SCA product has been developed in the framework of the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT), Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF) Project. The product is generated by using data from Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instrument making observations from a geostationary satellite Meteosat Second Generation (MSG). In the previous study evaluation of the model was done with commonly used statistical performance metrics (Nash-Sutcliffe) for high and low flows, volume error and root mean square error (RMSE). In this study signature metrics, which are based on the flow duration curve (FDC) are used to see the performance of the model for low flows. In order to consider a fairly balanced evaluation between high and low flow phases we divided the flow duration curve into segments of high, medium and low flow phases, and additionally into very high and very low phases. Root mean square error (RMSE) is used to evaluate the performance in these segments. The sensitivity analysis of the parameters around the calibrated optimum points showed that parameters of the soil moisture and evapotranspiration (FC, beta and LPrat) have a strong effect in the total volume error of the model. The parameters from the response and transformation routines (LSUZ, K1, K0 and bmax) have a significant influence on the peak flows. It is observed that the parameters of snow routine (Tmelt, CSF and DDF) have strong effect in high flows and total volume. The parameters FC, K0, K1 And K2 are found to have effect on low flows from the signature metrics.

  13. Pollution control and hydrologic Modeling

    NSDL National Science Digital Library

    Eugenio Arima

    Eugenio Y. Arima, Hobart and William Smith Colleges Summary This assignment will introduce students to surface hydrologic modeling in GIS and derived products such as stream power and wetness indices. Context Type ...

  14. Does model performance improve with complexity? A case study with three hydrological models

    NASA Astrophysics Data System (ADS)

    Orth, Rene; Staudinger, Maria; Seneviratne, Sonia I.; Seibert, Jan; Zappa, Massimiliano

    2015-04-01

    In recent decades considerable progress has been made in climate model development. Following the massive increase in computational power, models became more sophisti- cated. At the same time also simple conceptual models have advanced. In this study we validate and compare three hydrological models of different complexity to investigate whether their performance varies accordingly. For this purpose we use runoff and also soil moisture measurements, which allow a truly independent validation, from several sites across Switzerland. The models are calibrated in similar ways with the same runoff data. Our results show that the more complex models HBV and PREVAH outperform the simple water balance model (SWBM) in case of runoff but not for soil moisture. Furthermore the most sophisticated PREVAH model shows an added value compared to the HBV model only in case of soil moisture. Focusing on extreme events we find generally improved performance of the SWBM during drought conditions and degraded agreement with observations during wet extremes. For the more complex models we find the opposite behavior, probably because they were primarily developed for predic- tion of runoff extremes. As expected given their complexity, HBV and PREVAH have more problems with over-fitting. All models show a tendency towards better perfor- mance in lower altitudes as opposed to (pre-)alpine sites. The results vary considerably across the investigated sites. In contrast, the different metrics we consider to estimate the agreement between models and observations lead to similar conclusions, indicating that the performance of the considered models is similar at different time scales as well as for anomalies and long-term means. We conclude that added complexity does not necessarily lead to improved performance of hydrological models, and that performance can vary greatly depending on the considered hydrological variable (e.g. runoff vs. soil moisture) or hydrological conditions (floods vs. droughts).

  15. Teaching hydrological modeling with a user-friendly catchment-runoff-model software package

    NASA Astrophysics Data System (ADS)

    Seibert, J.; Vis, M. J. P.

    2012-05-01

    Computer models, and especially conceptual models, are frequently used for catchment hydrology studies. Teaching hydrological modeling, however, is challenging as students, when learning to apply computer models, have both to understand general model concepts and to be able to use particular computer programs. Here we present a new version of the HBV model. This software provides a user-friendly version which is especially useful for education. Different functionalities like an automatic calibration using a genetic algorithm or a Monte Carlo approach as well as the possibility to perform batch runs with predefined model parameters make the software also interesting for teaching in more advanced classes and research projects. Different teaching goals related to hydrological modeling are discussed and a series of exercises is suggested to reach these goals.

  16. Teaching hydrological modeling with a user-friendly catchment-runoff-model software package

    NASA Astrophysics Data System (ADS)

    Seibert, J.; Vis, M. J. P.

    2012-09-01

    Computer models, especially conceptual models, are frequently used for catchment hydrology studies. Teaching hydrological modeling, however, is challenging, since students have to both understand general model concepts and be able to use particular computer programs when learning to apply computer models. Here we present a new version of the HBV (Hydrologiska Byråns Vattenavdelning) model. This software provides a user-friendly version that is especially useful for education. Different functionalities, such as an automatic calibration using a genetic algorithm or a Monte Carlo approach, as well as the possibility to perform batch runs with predefined model parameters make the software interesting especially for teaching in more advanced classes and research projects. Different teaching goals related to hydrological modeling are discussed and a series of exercises is suggested to reach these goals.

  17. a statistical model based on serological parameters for predicting occult HBV infection: implications for organ/ blood donations.

    PubMed

    Coen, Sabrina; Angeletti, Claudio; Piselli, Pierluca; Tronchin, Michele; Vincenti, Donatella; Capobianchi, Maria Rosaria; Galli, Claudio; Menzo, Stefano

    2015-01-01

    The transmission of hepatitis B virus by donors with occult HBV infection (OBI) is a threat for blood transfusion and organ/tissue transplantation. The risk of carrying HBV DNA is currently not predictable by simple serologic markers, while HBV DNA testing is not universally deployed. This study evaluated an integrated serologic approach for assessing this risk. Anti-HBc positive subjects (461 HIV-negative, 262 HIV-positive) were selected for the study. Serology was analyzed by a commercial CMIA technique. HBV DNA was analyzed by both commercial and home-brew real-time amplification assays. A penalized maximum likelihood logistic approach was used to analyze the data. In HBsAg-negative subjects (HIV-negative), anti-HBc signal/cut off values, the presence of anti-HBc IgM, the absence of anti-HBsAg, and the absence of anti-HCV were correlated to the probability of finding circulating HBV DNA. A model for predicting HBV DNA presence by 4 serological parameters is therefore proposed. The predictive value of the logistic model based on simple serologic markers may represent a reasonable tool for the assessment of HBV transmission risk by transfusion or organ/tissue donation in the context of limited resources and where nucleic acid testing is not performed. In addition, it may be helpful for assessing the risk of reactivation in immunosuppressed OBI patients. PMID:25742146

  18. The woodchuck hepatitis B virus infection model for the evaluation of HBV therapies and vaccine therapies.

    PubMed

    D'Ugo, Emilio; Argentini, Claudio; Giuseppetti, Roberto; Canitano, Andrea; Catone, Stefania; Rapicetta, Maria

    2010-12-01

    Studies focused on the understanding of the molecular mechanisms involved in recovery or progression to chronicity of HBV may take advantage of natural and experimental models that mimic its properties. This is also of relevance for associated diseases such as cirrhosis and hepatocellulocarcinoma. The eastern woodchuck (Marmota monax) infected by the hepadnavirus woodchuck Hepatitis B virus (WHV) has been applied as a predictive model to support development of new HBV vaccines, antivirals, immunotherapies and combination therapies. This report summarizes studies carried out by our and other groups, with the application of this model in natural and experimental infections. Using standardized viral inocula in neonate and adult animals and newly established assays, the presence of the specific patterns of markers of acute, chronic and resolved infections and their relationships in the different virus-host interactions have been shown. B and T cell responses and T(H)1 cytokine expression have been shown to play a crucial role in the outcome of infection. The availability of the WHV/Marmota monax model and specific standardized assays may allow evaluation of new formulations of multimodal therapeutic strategies based on antiviral chemotherapy and immunomodulation. These may also include specifically targeted immunocomplexes. Such therapies could constitute new frontiers for the treatment of HBV chronic disease. PMID:22822718

  19. Virtual hydrology observatory: an immersive visualization of hydrology modeling

    NASA Astrophysics Data System (ADS)

    Su, Simon; Cruz-Neira, Carolina; Habib, Emad; Gerndt, Andreas

    2009-02-01

    The Virtual Hydrology Observatory will provide students with the ability to observe the integrated hydrology simulation with an instructional interface by using a desktop based or immersive virtual reality setup. It is the goal of the virtual hydrology observatory application to facilitate the introduction of field experience and observational skills into hydrology courses through innovative virtual techniques that mimic activities during actual field visits. The simulation part of the application is developed from the integrated atmospheric forecast model: Weather Research and Forecasting (WRF), and the hydrology model: Gridded Surface/Subsurface Hydrologic Analysis (GSSHA). Both the output from WRF and GSSHA models are then used to generate the final visualization components of the Virtual Hydrology Observatory. The various visualization data processing techniques provided by VTK are 2D Delaunay triangulation and data optimization. Once all the visualization components are generated, they are integrated into the simulation data using VRFlowVis and VR Juggler software toolkit. VR Juggler is used primarily to provide the Virtual Hydrology Observatory application with fully immersive and real time 3D interaction experience; while VRFlowVis provides the integration framework for the hydrologic simulation data, graphical objects and user interaction. A six-sided CAVETM like system is used to run the Virtual Hydrology Observatory to provide the students with a fully immersive experience.

  20. 3, 36293653, 2006 Hydrological model

    E-print Network

    Boyer, Edmond

    and surface flow models, water quality and quantity models. Another25 example is integration of water quality in urban waters and waste water treatments. 3630 #12;HESSD 3, 3629­3653, 2006 Hydrological model coupling of Water Resources, Delft University of Technology, Delft, The Netherlands 2 MX. Systems B.V., Rijswijk

  1. Effect of Trichinella spiralis infection on the immune response to HBV vaccine in a mouse model.

    PubMed

    Guan, Fei; Hou, Xiao; Nie, Ge; Xiao, Yan; Zhang, Qi; Liu, Wen-qi; Li, Yong-long; Lei, Jia-hui

    2013-10-01

    Vaccination is the most effective and cost-effective way to treat hepatitis B virus (HBV) infection. Collective data suggest that helminth infections affect immune responses to some vaccines. Therefore, it is important to reveal the effects of helminth infections on the efficacy of protective vaccines in countries with highly prevalent helminth infections. In the present work, effects of Trichinella spiralis infection on the protective efficacy of HBV vaccine in a mouse model were investigated. This study demonstrated that the enteric stage of T. spiralis infection could inhibit the proliferative response of spleen lymphocytes to hepatitis B surface antigen (HBsAg) and lead to lower levels of anti-HBsAg antibodies, interferon-?, and interleukin (IL)-2, along with higher levels of IL-4 and IL-5. However, these immunological differences are absent in the muscle stage of T. spiralis infection. The results suggest that the muscle stage of T. spiralis infection does not affect the immune response to HBV vaccination, while the enteric-stage infection results in a reduced immune response to HBsAg. PMID:23883369

  2. Model Calibration in Watershed Hydrology

    NASA Technical Reports Server (NTRS)

    Yilmaz, Koray K.; Vrugt, Jasper A.; Gupta, Hoshin V.; Sorooshian, Soroosh

    2009-01-01

    Hydrologic models use relatively simple mathematical equations to conceptualize and aggregate the complex, spatially distributed, and highly interrelated water, energy, and vegetation processes in a watershed. A consequence of process aggregation is that the model parameters often do not represent directly measurable entities and must, therefore, be estimated using measurements of the system inputs and outputs. During this process, known as model calibration, the parameters are adjusted so that the behavior of the model approximates, as closely and consistently as possible, the observed response of the hydrologic system over some historical period of time. This Chapter reviews the current state-of-the-art of model calibration in watershed hydrology with special emphasis on our own contributions in the last few decades. We discuss the historical background that has led to current perspectives, and review different approaches for manual and automatic single- and multi-objective parameter estimation. In particular, we highlight the recent developments in the calibration of distributed hydrologic models using parameter dimensionality reduction sampling, parameter regularization and parallel computing.

  3. Evaluation of Optimization Methods for Hydrologic Model Calibration in Ontario Basins

    NASA Astrophysics Data System (ADS)

    Razavi, T.; Coulibaly, P. D.

    2013-12-01

    Particle Swarm Optimization algorithm (PSO), Shuffled Complex Evolution algorithm (SCE), Non-Dominated Sorted Genetic algorithm II (NSGA II) and a Monte Carlo procedure are applied to optimize the calibration of two conceptual hydrologic models namely the Sacramento Soil Moisture Accounting (SAC-SMA) and McMaster University-Hydrologiska Byråns Vattenbalansavdelning (MAC-HBV). PSO, SCE, and NSGA II are inherently evolutionary computational methods with a potential of reaching the global optimum in contrast to stochastic search algorithms such as Monte Carlo method. The spatial analysis maps of Nash Sutcliffe Efficiency (NSE) for daily streamflow and Volume Error (VE) for peak and low flows demonstrate that for both MAC-HBV and SAC-SMA, PSO and SCE are equally superior to NSGAII and Monte Carlo for all the selected 90 basins across Ontario (Canada) using 20 years (1976-1994) of hydrologic records. For peakflows, MAC-HBV with PSO has generally better performance compared to SCE, whereas SAC-SMA with SCE and PSO indicate similar performance. For low flows, MAC-HBV with PSO has a better performance for most of the northern large watersheds while SCE has a better performance for southern small watersheds. Temporal variability of NSE values for daily streamflow show that all the optimization methods perform better for the winter season compared to the summer.

  4. A physical interpretation of hydrologic model complexity

    NASA Astrophysics Data System (ADS)

    Moayeri, MohamadMehdi; Pande, Saket

    2015-04-01

    It is intuitive that instability of hydrological system representation, in the sense of how perturbations in input forcings translate into perturbation in a hydrologic response, may depend on its hydrological characteristics. Responses of unstable systems are thus complex to model. We interpret complexity in this context and define complexity as a measure of instability in hydrological system representation. We provide algorithms to quantify model complexity in this context. We use Sacramento soil moisture accounting model (SAC-SMA) parameterized for MOPEX basins and quantify complexities of corresponding models. Relationships between hydrologic characteristics of MOPEX basins such as location, precipitation seasonality index, slope, hydrologic ratios, saturated hydraulic conductivity and NDVI and respective model complexities are then investigated. We hypothesize that complexities of basin specific SAC-SMA models correspond to aforementioned hydrologic characteristics, thereby suggesting that model complexity, in the context presented here, may have a physical interpretation.

  5. Attribution of hydrologic trends using integrated hydrologic and economic models

    NASA Astrophysics Data System (ADS)

    Maneta, M. P.; Brugger, D. R.; Silverman, N. L.

    2014-12-01

    Hydrologic change has been detected in many regions of the world in the form of trends in annual streamflows, varying depths to the regional water table, or other alterations of the hydrologic balance. Most models used to investigate these changes implement sophisticated descriptions of the physical system but use simplified descriptions of the socioeconomic system. These simplifications come in the form of prescribed water diversions and land use change scenarios, which provide little insight into coupled natural-human systems and have limited predictive capabilities. We present an integrated model that adds realism to the description of the hydrologic system in agricultural regions by incorporating a component that updates the allocation of land and water to crops in response to hydroclimatic (water available) and economic conditions (prices of commodities and agricultural inputs). This component assumes that farmers allocate resources to maximize their net revenues, thus justifying the use of optimality conditions to constrain the parameters of an empirical production function that captures the economic behavior of farmers. Because the model internalizes the feedback between climate, agricultural markets, and farming activity into the hydrologic system, it can be used to understand to what extent human economic activity can exacerbate or buffer the regional hydrologic impacts of climate change in agricultural regions. It can also help in the attribution of causes of hydrologic change. These are important issues because local policy and management cannot solve climate change, but they can address land use and agricultural water use. We demonstrate the model in a case study.

  6. Environmental Observatories and Hydrologic Modeling

    NASA Astrophysics Data System (ADS)

    Hooper, R. P.; Duncan, J. M.

    2006-12-01

    During the past several years, the environmental sciences community has been attempting to design large- scale obsevatories that will transform the science. A watershed-based observatory has emerged as an effective landscape unit for a broad range of environmental sciences and engineering. For an effective observatory, modeling is a central requirement because models are precise statements of the hypothesized conceptual organization of watersheds and of the processes believed to be controlling hydrology of the watershed. Furthermore, models can serve to determine the value of existing data and the incremental value of any additional data to be collected. Given limited resources, such valuation is mandatory for an objective design of an observatory. Modeling is one part of a "digital watershed" that must be constructed for any observatory, a concept that has been developed by the CUAHSI Hydrologic Information Systems project. A digital watershed has three functions. First, it permits assembly of time series (such as stream discharge or precipitation measurements), static spatial coverages (such as topography), and dynamic fields (such as precipitation radar and other remotely sensed data). Second, based upon this common data description, a digital observatory permits multiple conceptualizations of the observatory to be created and to be stored. These conceptualizations could range from lumped box-and-arrow watershed models, to semi-distributed topographically based models, to three-dimensional finite element models. Finally, each conceptualization can lead to multiple models--that is, a set of equations that quantitatively describe hydrologic (or biogeochemical or geomorphologic) processes through libraries of tools that can be linked as workflow sequences. The advances in cyberinfrastructure that allow the storage of multiple conceptualizations and multiple model formulations of these conceptualizations promise to accelerate advances in environmental science both by permitting greater efficiency in modeling but, more importantly, by permitting a deeper exchange of ideas among scientists from multiple disciplines.

  7. Committee of machine learning predictors of hydrological models uncertainty

    NASA Astrophysics Data System (ADS)

    Kayastha, Nagendra; Solomatine, Dimitri

    2014-05-01

    In prediction of uncertainty based on machine learning methods, the results of various sampling schemes namely, Monte Carlo sampling (MCS), generalized likelihood uncertainty estimation (GLUE), Markov chain Monte Carlo (MCMC), shuffled complex evolution metropolis algorithm (SCEMUA), differential evolution adaptive metropolis (DREAM), particle swarm optimization (PSO) and adaptive cluster covering (ACCO)[1] used to build a predictive models. These models predict the uncertainty (quantiles of pdf) of a deterministic output from hydrological model [2]. Inputs to these models are the specially identified representative variables (past events precipitation and flows). The trained machine learning models are then employed to predict the model output uncertainty which is specific for the new input data. For each sampling scheme three machine learning methods namely, artificial neural networks, model tree, locally weighted regression are applied to predict output uncertainties. The problem here is that different sampling algorithms result in different data sets used to train different machine learning models which leads to several models (21 predictive uncertainty models). There is no clear evidence which model is the best since there is no basis for comparison. A solution could be to form a committee of all models and to sue a dynamic averaging scheme to generate the final output [3]. This approach is applied to estimate uncertainty of streamflows simulation from a conceptual hydrological model HBV in the Nzoia catchment in Kenya. [1] N. Kayastha, D. L. Shrestha and D. P. Solomatine. Experiments with several methods of parameter uncertainty estimation in hydrological modeling. Proc. 9th Intern. Conf. on Hydroinformatics, Tianjin, China, September 2010. [2] D. L. Shrestha, N. Kayastha, and D. P. Solomatine, and R. Price. Encapsulation of parameteric uncertainty statistics by various predictive machine learning models: MLUE method, Journal of Hydroinformatic, in press, 2013. [3] N., Kayastha, J. Ye, F. Fenicia, V. Kuzmin, and D. P. Solomatine. Fuzzy committees of specialized rainfall-runoff models: further enhancements and tests. Hydrol. Earth Syst. Sci., 17, 4441-4451, 2013

  8. Hydrological model parameter uncertainty in investigations of climate change impacts on peak flow across Europe

    NASA Astrophysics Data System (ADS)

    Vormoor, Klaus; Lawrence, Deborah; Engin, Batuhan; Martinkova, Marta; Osuch, Marzena; Willems, Patrick; Yücel, Ismail

    2014-05-01

    Mulit-model ensemble approaches are usually used to investigate the hydrological impacts of climate change and their associated uncertainties. Uncertainties introduced by differing GCM/RCM combinations are assumed to have the largest influence on the overall uncertainty whereas the uncertainty derived from the hydrological model parameterisation is often assumed to have only a minor influence within the entire model chain. However, this does not always need to be the case, especially when changes in flood seasonality are likely. Since hydrological model calibration is a well-established tool for hydrologists, this comprises a possible field for improvements within climate impact studies. In this study we investigate the effect of using four different objective functions for the calibration of the HBV hydrological model in seven catchments across Europe, which represent differing geographical and climatological conditions. The objective functions used here are either modifications or extensions of the Nash-Sutcliffe criterion (NSE). Two of the objective functions are especially tailored to fit the model with respect to peak flows, while the other two are designed to estimate an optimal NSE whilst also minimising the volumetric bias. The global Dynamically Dimensioned Search (DDS) algorithm and a subsequent Monte-Carlo simulation was used to calibrate the HBV models for all seven catchments and to detect 4x25 best-fit parameter sets. These parameter sets are then applied to model the observed and future climate with respect to peak flows in all seven catchments. The aims of this study are (1) to address the parameter uncertainties associated by the 4x25 best-fit parameter sets and (2) to identify the objective functions that are best suited for calibrating the HBV model with respect to investigating changes in the frequency and intensity of flooding.

  9. Model complexity control for hydrologic prediction

    Microsoft Academic Search

    G. Schoups; N. C. van de Giesen; H. H. G. Savenije

    2008-01-01

    A common concern in hydrologic modeling is overparameterization of complex models given limited and noisy data. This leads to problems of parameter nonuniqueness and equifinality, which may negatively affect prediction uncertainties. A systematic way of controlling model complexity is therefore needed. We compare three model complexity control methods for hydrologic prediction, namely, cross validation (CV), Akaike's information criterion (AIC), and

  10. Methods for monitoring gene gun-induced HBV- and HCV-specific immune responses in mouse models.

    PubMed

    Ahlén, Gustaf; Sällberg, Matti; Frelin, Lars

    2013-01-01

    The hepatitis B and C viruses (HBV/HCV) are major causes for chronic liver disease globally. For HBV new antiviral compounds can suppress the viral replication for years, but off-therapy responses are rare. Current therapies based on interferon and ribavirin can cure 45-85% of the treated HCV-infected patients largely depending on the viral genotype. New regimens including protease inhibitors will be introduced during 2011 and these will increase the cure rates for the hardest to treat HCV genotype 1 from 45 to 65%. Here a major need is to replace the immunomodulatory effects of interferon and/or ribavirin. Thus, therapeutic vaccines have a place in both chronic HBV and HCV infection. Unfortunately, none of these viruses can infect mice whereby substitute models are needed. We have used several types of murine models to predict the clinical efficacy of therapeutic vaccines for chronic HBV and HCV infections. In this chapter we describe transdermal delivery of genetic vaccines using the Helios Gene Gun device. A central role is that the model should have generally functional immune response, but with selective defects towards HBV and/or HCV. Thus, mice with stable integrated transgenes are useful. However, as a simple model to study the hepatic entry and functionality of a HBV- and/or HCV-specific immune responses other models are needed, where a killed transgenic hepatocyte is replaced by a healthy non-transgenic hepatocyte. Here we can effectively apply a technique termed hydrodynamic injection, which makes 10-30% of hepatocytes transiently transgenic for any plasmid. Within this chapter the methods used to characterize transiently transgenic mice are described. The main methods are the hydrodynamic injection technique, detection of transgene expression by immuno-precipitation, western blot, and immunohistochemistry. Finally, the in vivo functionality of T cells can be determined by using stably transfected syngeneic tumor cell lines expressing HBV and/or HCV proteins. The tumor challenge model enables studies of in vivo T cell function, whereas the cytotoxicity assay is used to determine T cell function in vitro. Overall, these models effectively reveal the efficiency by which various vaccine technologies, including biolistic DNA vaccination can kill the "infected" hepatocyte. PMID:23104348

  11. Application of hydrological and hydraulic models for hydrological data transfer

    NASA Astrophysics Data System (ADS)

    Ostojski, Mieczys?aw

    2013-06-01

    This paper presents an application of hydrological and hydraulic models for transferring instantaneous discharges from a water gauge station to budgeting sites on rivers. Calculations were done using the following models: MIKE NAM rainfall-runoff model and a hydrodynamic MIKE 11 HD model. The simulations were carried out for the catchment of Warta River and its tributaries for the multiyear period 1999-2009.

  12. MODEL ABSTRACTION IN HYDROLOGIC MODELING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Model abstraction (MA) is a methodology for reducing the complexity of a simulation model while maintaining the validity of the simulation results with respect to the question that the simulation is being used to address. The MA explicitly deals with uncertainties in model structure and in model par...

  13. Remote sensing applications to hydrologic modeling

    NASA Technical Reports Server (NTRS)

    Dozier, J.; Estes, J. E.; Simonett, D. S.; Davis, R.; Frew, J.; Marks, D.; Schiffman, K.; Souza, M.; Witebsky, E.

    1977-01-01

    An energy balance snowmelt model for rugged terrain was devised and coupled to a flow model. A literature review of remote sensing applications to hydrologic modeling was included along with a software development outline.

  14. Impacts of Operator Order in Hydrological Models

    NASA Astrophysics Data System (ADS)

    Snowdon, A. P.; Craig, J. R.

    2009-05-01

    Operator-Splitting errors are inherent in many hydrological models and can lead to computational inefficiencies, parameter estimation issues and inaccurate model results. A detailed study of the operator splitting errors produced by standard implementations of VIC and TOPMODEL has been performed both to assess their significance and to evaluate methods to correct them. Both VIC and TOPMODEL have been incorporated into RAVEN, an object-oriented hydrological model developed at the University of Waterloo. RAVEN has been developed to model hydrological processes using flexible numerical algorithms. RAVEN's structure is specifically designed to separate the numerical methods from the conceptual design to provide flexibility and to allow a separation of the numerics from the physical representations. The advantages of this numerical and conceptual separation has led to a better understanding of the impacts that operator splitting has on existing hydrological models and has allowed for improvements within models that increase accuracy and minimize errors.

  15. Covariance Models for Hydrological Applications

    NASA Astrophysics Data System (ADS)

    Hristopulos, Dionissios

    2014-05-01

    This methodological contribution aims to present some new covariance models with applications in the stochastic analysis of hydrological processes. More specifically, we present explicit expressions for radially symmetric, non-differentiable, Spartan covariance functions in one, two, and three dimensions. The Spartan covariance parameters include a characteristic length, an amplitude coefficient, and a rigidity coefficient which determines the shape of the covariance function. Different expressions are obtained depending on the value of the rigidity coefficient and the dimensionality. If the value of the rigidity coefficient is much larger than one, the Spartan covariance function exhibits multiscaling. Spartan covariance models are more flexible than the classical geostatatistical models (e.g., spherical, exponential). Their non-differentiability makes them suitable for modelling the properties of geological media. We also present a family of radially symmetric, infinitely differentiable Bessel-Lommel covariance functions which are valid in any dimension. These models involve combinations of Bessel and Lommel functions. They provide a generalization of the J-Bessel covariance function, and they can be used to model smooth processes with an oscillatory decay of correlations. We discuss the dependence of the integral range of the Spartan and Bessel-Lommel covariance functions on the parameters. We point out that the dependence is not uniquely specified by the characteristic length, unlike the classical geostatistical models. Finally, we define and discuss the use of the generalized spectrum for characterizing different correlation length scales; the spectrum is defined in terms of an exponent ?. We show that the spectrum values obtained for exponent values less than one can be used to discriminate between mean-square continuous but non-differentiable random fields. References [1] D. T. Hristopulos and S. Elogne, 2007. Analytic properties and covariance functions of a new class of generalized Gibbs random fields, IEEE Transactions on Information Theory, 53(12), 4667 - 4679. [2] D. T. Hristopulos and M. Zukovic, 2011. Relationships between correlation lengths and integral scales for covariance models with more than two parameters, Stochastic Environmental Research and Risk Assessment, 25(1), 11-19. [3] D. T. Hristopulos, 2014. Radial Covariance Functions Motivated by Spatial Random Field Models with Local Interactions, arXiv:1401.2823 [math.ST] .

  16. Streamflow data assimilation for the mesoscale hydrologic model (mHM) using particle filtering

    NASA Astrophysics Data System (ADS)

    Noh, Seong Jin; Rakovec, Oldrich; Kumar, Rohini; Samaniego, Luis; Choi, Shin-woo

    2015-04-01

    Data assimilation has been becoming popular to increase the certainty of the hydrologic prediction considering various sources of uncertainty through the hydrologic modeling chain. In this study, we develop a data assimilation framework for the mesoscale hydrologic model (mHM 5.2, http://www.ufz.de/mhm) using particle filtering, which is a sequential DA method for non-linear and non-Gaussian models. The mHM is a grid based distributed model that is based on numerical approximations of dominant hydrologic processes having similarity with the HBV and VIC models. The developed DA framework for the mHM represents simulation uncertainty by model ensembles and updates spatial distributions of model state variables when new observations are available in each updating time interval. The evaluation of the proposed method is carried out within several large European basins via assimilating multiple streamflow measurements in a daily interval. Dimensional limitations of particle filtering is resolved by effective noise specification methods, which uses spatial and temporal correlation of weather forcing data to represent model structural uncertainty. The presentation will be focused on gains and limitations of streamflow data assimilation in several hindcasting experiments. In addition, impacts of non-Gaussian distributions of state variables on model performance will be discussed.

  17. Hydrologic design of a wetland: advantages of continuous modeling

    Microsoft Academic Search

    Kenneth D. Konyha; Douglas T. Shaw; Kurt W. Weiler

    1995-01-01

    A continuous hydrologic model for constructed or depressional wetlands, intended as a design tool to supplement event-based hydrologic methods, uses reservoir routing methods and is driven by daily rainfall and watershed inflows. Simulated daily hydrology provides annual and monthly water balances, hydroperiod distributions, flood frequency distributions, soil exceedance values for hydrologic plant suitability and retention time distributions. The model was

  18. Uncertainty in hydrologic modeling: Toward an integrated data assimilation framework

    Microsoft Academic Search

    Yuqiong Liu; Hoshin V. Gupta

    2007-01-01

    Despite significant recent developments in computational power and distributed hydrologic modeling, the issue of how to adequately address the uncertainty associated with hydrological predictions remains a critical and challenging one. This issue needs to be properly addressed for hydrological modeling to realize its maximum practical potential in environmental decision-making processes. Arguably, the key to properly addressing hydrologic uncertainty is to

  19. Dynamic Multicriteria Evaluation of Conceptual Hydrological Models

    NASA Astrophysics Data System (ADS)

    de Vos, N. J.; Rientjes, T. H.; Fenicia, F.; Gupta, H. V.

    2007-12-01

    Accurate and precise forecasts of river streamflows are crucial for successful management of water resources and under the threat of hydrological extremes such as floods and droughts. Conceptual rainfall-runoff models are the most popular approach in flood forecasting. However, the calibration and evaluation of such models is often oversimplified by the use of performance statistics that largely ignore the dynamic character of a watershed system. This research aims to find novel ways of model evaluation by identifying periods of hydrologic similarity and customizing evaluation within each period using multiple criteria. A dynamic approach to hydrologic model identification, calibration and testing can be realized by applying clustering algorithms (e.g., Self-Organizing Map, Fuzzy C-means algorithm) to hydrological data. These algorithms are able to identify clusters in the data that represent periods of hydrological similarity. In this way, dynamic catchment system behavior can be simplified within the clusters that are identified. Although clustering requires a number of subjective choices, new insights into the hydrological functioning of a catchment can be obtained. Finally, separate model multi-criteria calibration and evaluation is performed for each of the clusters. Such a model evaluation procedure shows to be reliable and gives much-needed feedback on exactly where certain model structures fail. Several clustering algorithms were tested on two data sets of meso-scale and large-scale catchments. The results show that the clustering algorithms define categories that reflect hydrological process understanding: dry/wet seasons, rising/falling hydrograph limbs, precipitation-driven/ non-driven periods, etc. The results of various clustering algorithms are compared and validated using expert knowledge. Calibration results on a conceptual hydrological model show that the common practice of single-criteria calibration over the complete time series fails to perform adequately in all periods or on all criteria. Subsequently, improved model structures are constructed and the evaluation repeated. We conclude that a dynamic, multi-criteria approach to model identifying and testing is effective in constructing models that are more accurate and precise in forecasting streamflow.

  20. Hydrological modeling based on remote sensing information

    Microsoft Academic Search

    G. A. Schultz

    1993-01-01

    Starting with the water balance equation the various terms of the equation are briefly discussed and the question, how far these parameters can be estimated with the aid of remote sensing data. The difference in use of RS data for the estimation of parameters of hydrological models and the use of such data as model input is discussed. For the

  1. Treatments of Precipitation Inputs to Hydrologic Models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrological models are used to assess many water resources problems from agricultural use and water quality to engineering issues. The success of these models are dependent on correct parameterization; the most sensitive being the rainfall input time series. These records can come from land-based ...

  2. Comparison of complex and parsimonious model structures by means of a modular hydrological model concept

    NASA Astrophysics Data System (ADS)

    Holzmann, Hubert; Massmann, Carolina

    2015-04-01

    A plenty of hydrological model types have been developed during the past decades. Most of them used a fixed design to describe the variable hydrological processes assuming to be representative for the whole range of spatial and temporal scales. This assumption is questionable as it is evident, that the runoff formation process is driven by dominant processes which can vary among different basins. Furthermore the model application and the interpretation of results is limited by data availability to identify the particular sub-processes, since most models were calibrated and validated only with discharge data. Therefore it can be hypothesized, that simpler model designs, focusing only on the dominant processes, can achieve comparable results with the benefit of less parameters. In the current contribution a modular model concept will be introduced, which allows the integration and neglection of hydrological sub-processes depending on the catchment characteristics and data availability. Key elements of the process modules refer to (1) storage effects (interception, soil), (2) transfer processes (routing), (3) threshold processes (percolation, saturation overland flow) and (4) split processes (rainfall excess). Based on hydro-meteorological observations in an experimental catchment in the Slovak region of the Carpathian mountains a comparison of several model realizations with different degrees of complexity will be discussed. A special focus is given on model parameter sensitivity estimated by Markov Chain Monte Carlo approach. Furthermore the identification of dominant processes by means of Sobol's method is introduced. It could be shown that a flexible model design - and even the simple concept - can reach comparable and equivalent performance than the standard model type (HBV-type). The main benefit of the modular concept is the individual adaptation of the model structure with respect to data and process availability and the option for parsimonious model design.

  3. Approaches to modelling hydrology and ecosystem interactions

    NASA Astrophysics Data System (ADS)

    Silberstein, Richard P.

    2014-05-01

    As the pressures of industry, agriculture and mining on groundwater resources increase there is a burgeoning un-met need to be able to capture these multiple, direct and indirect stresses in a formal framework that will enable better assessment of impact scenarios. While there are many catchment hydrological models and there are some models that represent ecological states and change (e.g. FLAMES, Liedloff and Cook, 2007), these have not been linked in any deterministic or substantive way. Without such coupled eco-hydrological models quantitative assessments of impacts from water use intensification on water dependent ecosystems under changing climate are difficult, if not impossible. The concept would include facility for direct and indirect water related stresses that may develop around mining and well operations, climate stresses, such as rainfall and temperature, biological stresses, such as diseases and invasive species, and competition such as encroachment from other competing land uses. Indirect water impacts could be, for example, a change in groundwater conditions has an impact on stream flow regime, and hence aquatic ecosystems. This paper reviews previous work examining models combining ecology and hydrology with a view to developing a conceptual framework linking a biophysically defensable model that combines ecosystem function with hydrology. The objective is to develop a model capable of representing the cumulative impact of multiple stresses on water resources and associated ecosystem function.

  4. Detecting hydrological changes through conceptual model

    NASA Astrophysics Data System (ADS)

    Viola, Francesco; Caracciolo, Domenico; Pumo, Dario; Francipane, Antonio; Valerio Noto, Leonardo

    2015-04-01

    Natural changes and human modifications in hydrological systems coevolve and interact in a coupled and interlinked way. If, on one hand, climatic changes are stochastic, non-steady, and affect the hydrological systems, on the other hand, human-induced changes due to over-exploitation of soils and water resources modifies the natural landscape, water fluxes and its partitioning. Indeed, the traditional assumption of static systems in hydrological analysis, which has been adopted for long time, fails whenever transient climatic conditions and/or land use changes occur. Time series analysis is a way to explore environmental changes together with societal changes; unfortunately, the not distinguishability between causes restrict the scope of this method. In order to overcome this limitation, it is possible to couple time series analysis with an opportune hydrological model, such as a conceptual hydrological model, which offers a schematization of complex dynamics acting within a basin. Assuming that model parameters represent morphological basin characteristics and that calibration is a way to detect hydrological signature at a specific moment, it is possible to argue that calibrating the model over different time windows could be a method for detecting potential hydrological changes. In order to test the capabilities of a conceptual model in detecting hydrological changes, this work presents different "in silico" experiments. A synthetic-basin is forced with an ensemble of possible future scenarios generated with a stochastic weather generator able to simulate steady and non-steady climatic conditions. The experiments refer to Mediterranean climate, which is characterized by marked seasonality, and consider the outcomes of the IPCC 5th report for describing climate evolution in the next century. In particular, in order to generate future climate change scenarios, a stochastic downscaling in space and time is carried out using realizations of an ensemble of General Circulation Models (GCMs) for the future scenarios 2046-2065 and 2081-2100. Land use changes (i.e., changes in the fraction of impervious area due to increasing urbanization) are explicitly simulated, while the reference hydrological responses are assessed by the spatially distributed, process-based hydrological model tRIBS, the TIN-based Real-time Integrated Basin Simulator. Several scenarios have been created, describing hypothetical centuries with steady conditions, climate change conditions, land use change conditions and finally complex conditions involving both transient climatic modifications and gradual land use changes. A conceptual lumped model, the EHSM (EcoHydrological Streamflow Model) is calibrated for the above mentioned scenarios with regard to different time-windows. The calibrated parameters show high sensitivity to anthropic variations in land use and/or climatic variability. Land use changes are clearly visible from parameters evolution especially when steady climatic conditions are considered. When the increase in urbanization is coupled with rainfall reduction the ability to detect human interventions through the analysis of conceptual model parameters is weakened.

  5. Use of KNN technique to improve the efficiency of SCE-UA optimisation method applied to the calibration of HBV Rainfall-Runoff model

    NASA Astrophysics Data System (ADS)

    Dakhlaoui, H.; Bargaoui, Z.

    2007-12-01

    The Calibration of Rainfall-Runoff models can be viewed as an optimisation problem involving an objective function that measures the model performance expressed as a distance between observed and calculated discharges. Effectiveness (ability to find the optimum) and efficiency (cost expressed in number of objective function evaluations to reach the optimum) are the main criteria of choose of the optimisation method. SCE-UA is known as one of the most effective and efficient optimisation method. In this work we tried to improve the SCE-UA efficiency, in the case of the calibration of HBV model by using KNN technique to estimate the objective function. In fact after a number of iterations by SCE-UA, when objective function is evaluated by model simulation, a data base of parameter explored and respective objective function values is constituted. Within this data base it is proposed to estimate the objective function in further iterations, by an interpolation using nearest neighbours in a normalised parameter space with weighted Euclidean distance. Weights are chosen proportional to the sensitivity of parameter to objective function that gives more importance to sensitive parameter. Evaluation of model output is done through the objective function RV=R2- w |RD| where R2 is Nash Sutcliffe coefficient related to discharges, w : a weight and RD the relative bias. Applied to theoretical and practical cases in several catchments under different climatic conditions : Rottweil (Germany) and Tessa, Barbra, and Sejnane (Tunisia), the hybrid SCE-UA presents efficiency better then that of initial SCE-UA by about 20 to 30 %. By using other techniques as parameter space transformation and SCE-UA modification (2), we may obtain an algorithm two to three times faster. (1) Avi Ostfeld, Shani Salomons, "A hybrid genetic-instance learning algorithm for CE*QAL-W2 calibration", Journal of Hydrology 310 (2005) 122-125 (2) Nitin Mutil and Shie-Yui Liong, "Improved robustness and Efficiency of the SCE-UA model calibrating algorithm"

  6. Revising Hydrology of a Land Surface Model

    NASA Astrophysics Data System (ADS)

    Le Vine, Nataliya; Butler, Adrian; McIntyre, Neil; Jackson, Christopher

    2015-04-01

    Land Surface Models (LSMs) are key elements in guiding adaptation to the changing water cycle and the starting points to develop a global hyper-resolution model of the terrestrial water, energy and biogeochemical cycles. However, before this potential is realised, there are some fundamental limitations of LSMs related to how meaningfully hydrological fluxes and stores are represented. An important limitation is the simplistic or non-existent representation of the deep subsurface in LSMs; and another is the lack of connection of LSM parameterisations to relevant hydrological information. In this context, the paper uses a case study of the JULES (Joint UK Land Environmental Simulator) LSM applied to the Kennet region in Southern England. The paper explores the assumptions behind JULES hydrology, adapts the model structure and optimises the coupling with the ZOOMQ3D regional groundwater model. The analysis illustrates how three types of information can be used to improve the model's hydrology: a) observations, b) regionalized information, and c) information from an independent physics-based model. It is found that: 1) coupling to the groundwater model allows realistic simulation of streamflows; 2) a simple dynamic lower boundary improves upon JULES' stationary unit gradient condition; 3) a 1D vertical flow in the unsaturated zone is sufficient; however there is benefit in introducing a simple dual soil moisture retention curve; 4) regionalized information can be used to describe soil spatial heterogeneity. It is concluded that relatively simple refinements to the hydrology of JULES and its parameterisation method can provide a substantial step forward in realising its potential as a high-resolution multi-purpose model.

  7. Optimizing hydrological consistency by incorporating hydrological signatures into model calibration objectives

    NASA Astrophysics Data System (ADS)

    Shafii, Mahyar; Tolson, Bryan A.

    2015-05-01

    The simulated outcome of a calibrated hydrologic model should be hydrologically consistent with the measured response data. Hydrologic modelers typically calibrate models to optimize residual-based goodness-of-fit measures, e.g., the Nash-Sutcliffe efficiency measure, and then evaluate the obtained results with respect to hydrological signatures, e.g., the flow duration curve indices. The literature indicates that the consideration of a large number of hydrologic signatures has not been addressed in a full multiobjective optimization context. This research develops a model calibration methodology to achieve hydrological consistency using goodness-of-fit measures, many hydrological signatures, as well as a level of acceptability for each signature. The proposed framework relies on a scoring method that transforms any hydrological signature to a calibration objective. These scores are used to develop the hydrological consistency metric, which is maximized to obtain hydrologically consistent parameter sets during calibration. This consistency metric is implemented in different signature-based calibration formulations that adapt the sampling according to hydrologic signature values. These formulations are compared with the traditional formulations found in the literature for seven case studies. The results reveal that Pareto dominance-based multiobjective optimization yields the highest level of consistency among all formulations. Furthermore, it is found that the choice of optimization algorithms does not affect the findings of this research.

  8. HYDROLOGY OF AGRICULTURAL LAND: PART I USDA-EVERGLADES AGRO-HYDROLOGY COMPUTER MODEL (EAHM)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several hydrologic models have been used in Miami-Dade County over the last decade. These models differ in complexity, application scale and were developed for different objectives. The USDA-Everglades Agro-Hydrology model is a field-scale model that can be used in conjunction with a regional-scale ...

  9. Global-scale regionalization of hydrological model parameters using streamflow data from many small catchments

    NASA Astrophysics Data System (ADS)

    Beck, Hylke; de Roo, Ad; van Dijk, Albert; McVicar, Tim; Miralles, Diego; Schellekens, Jaap; Bruijnzeel, Sampurno; de Jeu, Richard

    2015-04-01

    Motivated by the lack of large-scale model parameter regionalization studies, a large set of 3328 small catchments (< 10000 km2) around the globe was used to set up and evaluate five model parameterization schemes at global scale. The HBV-light model was chosen because of its parsimony and flexibility to test the schemes. The catchments were calibrated against observed streamflow (Q) using an objective function incorporating both behavioral and goodness-of-fit measures, after which the catchment set was split into subsets of 1215 donor and 2113 evaluation catchments based on the calibration performance. The donor catchments were subsequently used to derive parameter sets that were transferred to similar grid cells based on a similarity measure incorporating climatic and physiographic characteristics, thereby producing parameter maps with global coverage. Overall, there was a lack of suitable donor catchments for mountainous and tropical environments. The schemes with spatially-uniform parameter sets (EXP2 and EXP3) achieved the worst Q estimation performance in the evaluation catchments, emphasizing the importance of parameter regionalization. The direct transfer of calibrated parameter sets from donor catchments to similar grid cells (scheme EXP1) performed best, although there was still a large performance gap between EXP1 and HBV-light calibrated against observed Q. The schemes with parameter sets obtained by simultaneously calibrating clusters of similar donor catchments (NC10 and NC58) performed worse than EXP1. The relatively poor Q estimation performance achieved by two (uncalibrated) macro-scale hydrological models suggests there is considerable merit in regionalizing the parameters of such models. The global HBV-light parameter maps and ancillary data are freely available via http://water.jrc.ec.europa.eu.

  10. The value of multiple data set calibration versus model complexity for improving the performance of hydrological models in mountain catchments

    NASA Astrophysics Data System (ADS)

    Finger, David; Vis, Marc; Huss, Matthias; Seibert, Jan

    2015-04-01

    The assessment of snow, glacier, and rainfall runoff contribution to discharge in mountain streams is of major importance for an adequate water resource management. Such contributions can be estimated via hydrological models, provided that the modeling adequately accounts for snow and glacier melt, as well as rainfall runoff. We present a multiple data set calibration approach to estimate runoff composition using hydrological models with three levels of complexity. For this purpose, the code of the conceptual runoff model HBV-light was enhanced to allow calibration and validation of simulations against glacier mass balances, satellite-derived snow cover area and measured discharge. Three levels of complexity of the model were applied to glacierized catchments in Switzerland, ranging from 39 to 103 km2. The results indicate that all three observational data sets are reproduced adequately by the model, allowing an accurate estimation of the runoff composition in the three mountain streams. However, calibration against only runoff leads to unrealistic snow and glacier melt rates. Based on these results, we recommend using all three observational data sets in order to constrain model parameters and compute snow, glacier, and rain contributions. Finally, based on the comparison of model performance of different complexities, we postulate that the availability and use of different data sets to calibrate hydrological models might be more important than model complexity to achieve realistic estimations of runoff composition.

  11. Hydrology

    ERIC Educational Resources Information Center

    Sharp, John M., Jr.

    1978-01-01

    The past year saw a re-emphasis on the practical aspects of hydrology due to regional drought patterns, urban flooding, and agricultural and energy demands on water resources. Highlights of hydrologic symposia, publications, and events are included. (MA)

  12. Satellite-derived digital elevation model accuracy: hydrological modelling requirements

    NASA Astrophysics Data System (ADS)

    Endreny, T. A.; Wood, E. F.; Lettenmaier, D. P.

    2000-02-01

    Hydrological models can benefit from satellite-derived digital elevation models (DEMs) only after determining the hydrological model sensitivity to DEM inaccuracies. This study examined how vertical errors within a SPOT satellite-derived DEM of the 532 km2 Little Washita River, OK, watershed affected hydrological predictions in the TOPLATS (topographically based land-atmosphere transfer scheme) water and energy balance model. Model predictions based on SPOT-derived DEM inputs were compared with US Geological Survey (USGS) 7·5-minute level 1 and level 2 DEM-based predictions to determine model sensitivity. Ten-year simulation runs using a statistical formulation of TOPLATS indicated that while DEM inaccuracies had little effect on basin average output, they had a significant effect on the upper and lower quartiles of predicted water table depth. In 12-day simulation runs using a spatially explicit formulation of TOPLATS, which used 30-m grid cells across a 600 000 pixel model domain, elevation errors propagated into model predictions of soil moisture, runoff, evapotranspiration, incoming solar radiation and surface skin temperature. Aggregation of the 30-m pixel model output to scales of 0·25 km2, however, reduced differences between model-predicted vadose zone hydrology. Agreement between model-predicted water table hydrology was achieved at much larger scales of 5 km2, indicating that topography and its associated error structure may have a greater influence on saturated rather than unsaturated hydrological modelling.

  13. Distributed Hydrologic Models for Flow Forecasts - Part 1

    NSDL National Science Digital Library

    2014-09-14

    Distributed Hydrologic Models for Flow Forecasts – Part 1 provides a basic description of distributed hydrologic models and how they work. This module is the first in a two-part series focused on the science of distributed models and their applicability in different situations. Presented by Dr. Dennis Johnson, the module begins with a review of hydrologic models, and then examines the differences between lumped and distributed models. It explains how lumped models may be distributed by subdividing the basin and suggests when distributed hydrologic models are most appropriate. Other topics covered include the advantages of physically-based versus conceptual approaches and some strengths and challenges associated with distributed modeling.

  14. Hydrological change detection using modeling: Half a century of runoff from four rivers in the Blue Nile Basin

    NASA Astrophysics Data System (ADS)

    Gebrehiwot, Solomon Gebreyohannis; Seibert, Jan; Gärdenäs, Annemieke I.; Mellander, Per-Erik; Bishop, Kevin

    2013-06-01

    Land cover changes can have significant impacts on hydrological regime. The objective of this study was to detect possible hydrological changes of four watersheds in the Blue Nile Basin using a model-based method for hydrological change detection. The four watersheds, Birr, Upper-Didesa, Gilgel Abbay, and Koga range in size from 260 to 1800 km2. The changes were assessed based on model parameters, model residuals, and in the overall function of the watersheds in transferring rainfall into runoff. The entire time series (1960-2004) was divided into three periods based on political and land management policy changes. A conceptual rainfall-runoff model, the HBV (Hydrologiska Byråns Vattenbalansavdelning) model, was used for the analysis, and suitable parameter sets for each period were found based on a Monte Carlo approach. The values of six out of nine parameters changed significantly between the periods. Model residuals also showed significant changes between the three periods in three of the four watersheds. On the other hand, the overall functioning of the watersheds in processing rainfall to runoff changed little. So even though the individual parameters and model residuals were changing, the integrated functioning of the watersheds showed minimal changes. This study demonstrated the value of using different approaches for detecting hydrological change and highlighted the sensitivity of the outcome to the applied modeling and statistical methods.

  15. A Smallholder Socio-hydrological Modelling Framework

    NASA Astrophysics Data System (ADS)

    Pande, S.; Savenije, H.; Rathore, P.

    2014-12-01

    Small holders are farmers who own less than 2 ha of farmland. They often have low productivity and thus remain at subsistence level. A fact that nearly 80% of Indian farmers are smallholders, who merely own a third of total farmlands and belong to the poorest quartile, but produce nearly 40% of countries foodgrains underlines the importance of understanding the socio-hydrology of a small holder. We present a framework to understand the socio-hydrological system dynamics of a small holder. It couples the dynamics of 6 main variables that are most relevant at the scale of a small holder: local storage (soil moisture and other water storage), capital, knowledge, livestock production, soil fertility and grass biomass production. The model incorporates rule-based adaptation mechanisms (for example: adjusting expenditures on food and fertilizers, selling livestocks etc.) of small holders when they face adverse socio-hydrological conditions, such as low annual rainfall, higher intra-annual variability in rainfall or variability in agricultural prices. It allows us to study sustainability of small holder farming systems under various settings. We apply the framework to understand the socio-hydrology of small holders in Aurangabad, Maharashtra, India. This district has witnessed suicides of many sugarcane farmers who could not extricate themselves out of the debt trap. These farmers lack irrigation and are susceptible to fluctuating sugar prices and intra-annual hydroclimatic variability. This presentation discusses two aspects in particular: whether government interventions to absolve the debt of farmers is enough and what is the value of investing in local storages that can buffer intra-annual variability in rainfall and strengthening the safety-nets either by creating opportunities for alternative sources of income or by crop diversification.

  16. Modeling of aggregated hydrologic time series

    NASA Astrophysics Data System (ADS)

    Obeysekera, J. T. B.; Salas, J. D.

    1986-10-01

    The concept of aggregation of the most commonly used models of seasonal hydrologic time series is the main subject discussed herein. The PAR(1) and PARMA(1, 1) models are assumed for representing the seasonal series and their equivalent stationarity and invertibility conditions are given. Likewise explicit expressions are given for determining the periodic covariance structure of such models and the concept of aggregation is illustrated by deriving the model of the corresponding annual series. Since the models of the seasonal series dictate the type of model of the annual series, then a unique structural linkage in the usual linear disaggregation model may be obtained in closed form. Seasonal and annual flows of the Niger River are used to illustrate some of the estimation procedures based on the foregoing aggregation approach.

  17. Assimilation of remote sensing observations into a continuous distributed hydrological model: impacts on the hydrologic cycle

    NASA Astrophysics Data System (ADS)

    Laiolo, Paola; Gabellani, Simone; Campo, Lorenzo; Cenci, Luca; Silvestro, Francesco; Delogu, Fabio; Boni, Giorgio; Rudari, Roberto

    2015-04-01

    The reliable estimation of hydrological variables (e.g. soil moisture, evapotranspiration, surface temperature) in space and time is of fundamental importance in operational hydrology to improve the forecast of the rainfall-runoff response of catchments and, consequently, flood predictions. Nowadays remote sensing can offer a chance to provide good space-time estimates of several hydrological variables and then improve hydrological model performances especially in environments with scarce in-situ data. This work investigates the impact of the assimilation of different remote sensing products on the hydrological cycle by using a continuous physically based distributed hydrological model. Three soil moisture products derived by ASCAT (Advanced SCATterometer) are used to update the model state variables. The satellite-derived products are assimilated into the hydrological model using different assimilation techniques: a simple nudging and the Ensemble Kalman Filter. Moreover two assimilation strategies are evaluated to assess the impact of assimilating the satellite products at model spatial resolution or at the satellite scale. The experiments are carried out for three Italian catchments on multi year period. The benefits on the model predictions of discharge, LST, evapotranspiration and soil moisture dynamics are tested and discussed.

  18. Plant growth simulation for landscape scale hydrologic modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Landscape scale hydrologic models can be improved by incorporating realistic, process-oriented plant models for simulating crops, grasses, and woody species. The objective of this project was to present some approaches for plant modeling applicable to hydrologic models like SWAT that can affect the...

  19. Coupled land surface/hydrologic/atmospheric models

    NASA Technical Reports Server (NTRS)

    Pielke, Roger; Steyaert, Lou; Arritt, Ray; Lahtakia, Mercedes; Smith, Chris; Ziegler, Conrad; Soong, Su Tzai; Avissar, Roni; Wetzel, Peter; Sellers, Piers

    1993-01-01

    The topics covered include the following: prototype land cover characteristics data base for the conterminous United States; surface evapotranspiration effects on cumulus convection and implications for mesoscale models; the use of complex treatment of surface hydrology and thermodynamics within a mesoscale model and some related issues; initialization of soil-water content for regional-scale atmospheric prediction models; impact of surface properties on dryline and MCS evolution; a numerical simulation of heavy precipitation over the complex topography of California; representing mesoscale fluxes induced by landscape discontinuities in global climate models; emphasizing the role of subgrid-scale heterogeneity in surface-air interaction; and problems with modeling and measuring biosphere-atmosphere exchanges of energy, water, and carbon on large scales.

  20. Assessment of Uncertainty of Forest Road Hydrology Modeling with the Distributed Hydrology Soil Vegetation Model (DHSVM)

    NASA Astrophysics Data System (ADS)

    Surfleet, C. G.; Skaugset, A. E.; McDonnell, J.

    2007-12-01

    The effects of forest roads on catchment hydrology and sediment production continue to be the focus of concern for impacts to aquatic habitat. However, these processes are complex and difficult to measure at catchment scales. Consequently, the effects of forest roads on watershed hydrology are often studied using distributed hydrologic models. We examined a popular distributed hydrology model used in the Western USA, the Distributive Hydrology Soil Vegetation Model (DHSVM), to predict changes in peak flows, storm run-off volume, and interception of sub-surface flow from forest roads. We apply DHSVM to a 630 hectare watershed in the headwaters of Oak Creek in the McDonald/Dunn Research Forest, managed by the College of Forestry, Oregon State University. The Generalized Likelihood Uncertainty Estimation (GLUE) approach was used to determine the uncertainty of model output for 10,000 model structures. Estimates of road ditchflow and streamflow from the GLUE assessment of DHSVM were compared to observed road ditchflow and streamflow for 2003-2006. Generally DHSVM simulations provided a reasonable fit to the time series for Oak Creek streamflow. The fit of the time series data diminished with spatial scale and for road ditchflow locations. From the GLUE assessment the percentage of DHSVM model structures that exceeded a Nash/Sutcliffe Efficiency of 0.5 were 44% for Oak Creek streamflow but reduced to a range of 0-9% for road locations. The conceptual model for road interception used within DHSVM did not accurately predict road ditchflow throughout the catchment. Given the many uncertainties observed from DHSVM road ditchflow results we question whether cumulative effects analysis of road influences on peak flows and storm volumes with DHSVM is appropriate for catchments with highly variable hillslope responses, such as Oak Creek.

  1. Impact of geological model uncertainty on integrated catchment hydrological modeling

    NASA Astrophysics Data System (ADS)

    He, Xin; Jørgensen, Flemming; Refsgaard, Jens Christian

    2014-05-01

    Various types of uncertainty can influence hydrological model performance. Among them, uncertainty originated from geological model may play an important role in process-based integrated hydrological modeling, if the model is used outside the calibration base. In the present study, we try to assess the hydrological model predictive uncertainty caused by uncertainty of the geology using an ensemble of geological models with equal plausibility. The study is carried out in the 101 km2 Norsminde catchment in western Denmark. Geostatistical software TProGS is used to generate 20 stochastic geological realizations for the west side the of study area. This process is done while incorporating the borehole log data from 108 wells and high resolution airborne transient electromagnetic (AEM) data for conditioning. As a result, 10 geological models are generated based solely on borehole data, and another 10 geological models are based on both borehole and AEM data. Distributed surface water - groundwater models are developed using MIKE SHE code for each of the 20 geological models. The models are then calibrated using field data collected from stream discharge and groundwater head observations. The model simulation results are evaluated based on the same two types of field data. The results show that the differences between simulated discharge flows caused by using different geological models are relatively small. The model calibration is shown to be able to account for the systematic bias in different geological realizations and hence varies the calibrated model parameters. This results in an increase in the variance between the hydrological realizations compared to the uncalibrated models that uses the same parameter values in all 20 models. Furthermore, borehole based hydrological models in general show more variance between simulations than the AEM based models; however, the combined total uncertainty, bias plus variance, is not necessarily higher.

  2. Testing calibration routines for LISFLOOD, a distributed hydrological model

    Microsoft Academic Search

    B. Pannemans

    2009-01-01

    Traditionally hydrological models are considered as difficult to calibrate: their highly non-linearity results in rugged and rough response surfaces were calibration algorithms easily get stuck in local minima. For the calibration of distributed hydrological models two extra factors play an important role: on the one hand they are often costly on computation, thus restricting the feasible number of model runs;

  3. Plant adaptive behaviour in hydrological models (Invited)

    NASA Astrophysics Data System (ADS)

    van der Ploeg, M. J.; Teuling, R.

    2013-12-01

    Models that will be able to cope with future precipitation and evaporation regimes need a solid base that describes the essence of the processes involved [1]. Micro-behaviour in the soil-vegetation-atmosphere system may have a large impact on patterns emerging at larger scales. A complicating factor in the micro-behaviour is the constant interaction between vegetation and geology in which water plays a key role. The resilience of the coupled vegetation-soil system critically depends on its sensitivity to environmental changes. As a result of environmental changes vegetation may wither and die, but such environmental changes may also trigger gene adaptation. Constant exposure to environmental stresses, biotic or abiotic, influences plant physiology, gene adaptations, and flexibility in gene adaptation [2-6]. Gene expression as a result of different environmental conditions may profoundly impact drought responses across the same plant species. Differences in response to an environmental stress, has consequences for the way species are currently being treated in models (single plant to global scale). In particular, model parameters that control root water uptake and plant transpiration are generally assumed to be a property of the plant functional type. Assigning plant functional types does not allow for local plant adaptation to be reflected in the model parameters, nor does it allow for correlations that might exist between root parameters and soil type. Models potentially provide a means to link root water uptake and transport to large scale processes (e.g. Rosnay and Polcher 1998, Feddes et al. 2001, Jung 2010), especially when powered with an integrated hydrological, ecological and physiological base. We explore the experimental evidence from natural vegetation to formulate possible alternative modeling concepts. [1] Seibert, J. 2000. Multi-criteria calibration of a conceptual runoff model using a genetic algorithm. Hydrology and Earth System Sciences 4(2): 215-224. [2] McClintock B. The significance of responses of the genome to challenge. Science 1984; 226: 792-801 [3] Ries G, Heller W, Puchta H, Sandermann H, Seldlitz HK, Hohn B. Elevated UV-B radiation reduces genome stability in plants. Nature 2000; 406: 98-101 [4] Lucht JM, Mauch-Mani B, Steiner H-Y, Metraux J-P, Ryals, J, Hohn B. Pathogen stress increases somatic recombination frequency in Arabidopsis. Nature Genet. 2002; 30: 311-314 [5] Kovalchuk I, Kovalchuk O, Kalck V., Boyko V, Filkowski J, Heinlein M, Hohn B. Pathogen-induced systemic plant signal triggers DNA rearrangements. Nature 2003; 423: 760-762 [6] Cullis C A. Mechanisms and control of rapid genomic changes in flax. Ann. Bot. (Lond.) 2005; 95: 201-206 [7] de Rosnay, P. and J. Polcher. 1998. Modelling root water uptake in a complex land surface scheme coupled to a GCM. Hydrology and Earth System Sciences 2: 239-255. [8] Feddes, R.A., H. Hoff, M. Bruen, T. Dawson, P. de Rosnay, P. Dirmeyer, R.B. Jackson, P. Kabat, A. Kleidon, A. Lilly, and A.J. Pitman. 2001. Modeling root water uptake in hydrological and climate models. Bulletin of the American Meteorological Society 82: 2797-2809. [9] Jung, M., M. Reichstein, P. Ciais, S.I. Seneviratne, J. Sheffield et al. 2010. Recent decline in the global land evaporation trend due to limited moisture supply. Nature 476: 951-954, doi:10.1038/nature09396.

  4. Hydrological modelling in sandstone rocks watershed

    NASA Astrophysics Data System (ADS)

    Ponížilová, Iva; Unucka, Jan

    2015-04-01

    The contribution is focused on the modelling of surface and subsurface runoff in the Plou?nice basin. The used rainfall-runoff model is HEC-HMS comprising of the method of SCS CN curves and a recession method. The geological subsurface consisting of sandstone is characterised by reduced surface runoff and, on the contrary, it contributes to subsurface runoff. The aim of this paper is comparison of the rate of influence of sandstone on reducing surface runoff. The recession method for subsurface runoff was used to determine the subsurface runoff. The HEC-HMS model allows semi- and fully distributed approaches to schematisation of the watershed and rainfall situations. To determine the volume of runoff the method of SCS CN curves is used, which results depend on hydrological conditions of the soils. The rainfall-runoff model assuming selection of so-called methods of event of the SCS-CN type is used to determine the hydrograph and peak flow rate based on simulation of surface runoff in precipitation exceeding the infiltration capacity of the soil. The recession method is used to solve the baseflow (subsurface) runoff. The method is based on the separation of hydrograph to direct runoff and subsurface or baseflow runoff. The study area for the simulation of runoff using the method of SCS CN curves to determine the hydrological transformation is the Plou?nice basin. The Plou?nice is a hydrologically significant river in the northern part of the Czech Republic, it is a right tributary of the Elbe river with a total basin area of 1.194 km2. The average value of CN curves for the Plou?nice basin is 72. The geological structure of the Plou?nice basin is predominantly formed by Mesozoic sandstone. Despite significant initial loss of rainfall the basin response to the causal rainfall was demonstrated by a rapid rise of the surface runoff from the watershed and reached culmination flow. Basically, only surface runoff occures in the catchment during the initial phase of this extreme event. The increase of the baseflow runoff is slower and remains constant after reaching a certain level. The rise of the baseflow runoff is showed in a descending part of the hydrograph. The recession method in this case shows almost 20 hours delay. Results from the HEC-HMS prove availability of both methods for the runoff modeling in this type of catchment. When simulating extreme short-term rainfall-runoff episodes, the influence of geological subsurface is not significant, but it is manifested. Using more relevant rainfall events would bring more satisfactory results.

  5. Improvements of Physically-Based Hydrological Modelling using the ACRU Agro-Hydrological Modelling System

    NASA Astrophysics Data System (ADS)

    Bonifacio, C. M. T.; Kienzle, S. W.; Xu, W.; Zhang, J.

    2014-12-01

    The uncertainty of future water availability due to climate change in the Upper Oldman River Basin in Alberta, Canada, and downstream users is considered in this study. A changing climate can significantly perturb hydrological response within a region, thereby affecting the available water resources within southern Alberta. The ACRU agro-hydrological modelling system is applied to simulate historical (1950-2010) and future (2041-2070) streamflows and volumes of a major irrigation reservoir. Like many highly complex, process-based distributed models, major limitations include the data availability and data quality at finer spatial resolutions. With the use of a scripting language, certain limitations can be greatly reduced. Three phases of the project will be emphasized. First, the assimilation of solar radiation, relative humidity, sunshine hours and wind speed daily data into the Canadian 10KM daily climate data that contains daily precipitation, maximum and minimum temperature data for the period 1950-2010, so as to enable potential evapotranspiration calculations using the Penman-Monteith equation. Second, the downscaling of five regional climate model (RCM) data to match the 10KM spatial resolution was undertaken. Third, a total of 1722 hydrological response units (HRUs) were delineated within the 4403 km2 large upper Oldman River Basin. In all phases of model input data parameterization and calibration, the automation of known external procedures greatly decreased erroneous model inputs and increased the efficiency of validating the quality of input data to be used within the ACRU model.

  6. Comparing TRMM 3B42, CFSR and ground-based rainfall estimates as input for hydrological models, in data scarce regions: the Upper Blue Nile Basin, Ethiopia

    NASA Astrophysics Data System (ADS)

    Worqlul, A. W.; Collick, A. S.; Tilahun, S. A.; Langan, S.; Rientjes, T. H. M.; Steenhuis, T. S.

    2015-02-01

    Accurate prediction of hydrological models requires accurate spatial and temporal distribution of rainfall observation network. In developing countries rainfall observation station network are sparse and unevenly distributed. Satellite-based products have the potential to overcome these shortcomings. The objective of this study is to compare the advantages and the limitation of commonly used high-resolution satellite rainfall products as input to hydrological models as compared to sparsely populated network of rain gauges. For this comparison we use two semi-distributed hydrological models Hydrologiska Byråns Vattenbalansavdelning (HBV) and Parameter Efficient Distributed (PED) that performed well in Ethiopian highlands in two watersheds: the Gilgel Abay with relatively dense network and Main Beles with relatively scarce rain gauge stations. Both are located in the Upper Blue Nile Basin. The two models are calibrated with the observed discharge from 1994 to 2003 and validated from 2004 to 2006. Satellite rainfall estimates used includes Climate Forecast System Reanalysis (CFSR), Tropical Rainfall Measuring Mission (TRMM) 3B42 version 7 and ground rainfall measurements. The results indicated that both the gauged and the CFSR precipitation estimates were able to reproduce the stream flow well for both models and both watershed. TRMM 3B42 performed poorly with Nash Sutcliffe values less than 0.1. As expected the HBV model performed slightly better than the PED model, because HBV divides the watershed into sub-basins resulting in a greater number of calibration parameters. The simulated discharge for the Gilgel Abay was better than for the less well endowed (rain gauge wise) Main Beles. Finally surprisingly, the ground based gauge performed better for both watersheds (with the exception of extreme events) than TRMM and CFSR satellite rainfall estimates. Undoubtedly in the future, when improved satellite products will become available, this will change.

  7. Modeling Sensor Knowledge of a National Hydrologic Information System

    E-print Network

    Molina, Martín

    .). The current initiatives about sensor web for globally distributed data acquisition [2] and semantic sensor web1 Modeling Sensor Knowledge of a National Hydrologic Information System Martin Molina and Javier. In this paper we describe our experience in modeling and using sensor knowledge of a national hydrologic

  8. Development of an Open Source GIS based Distributed Hydrological model System - MWEasyDHM

    Microsoft Academic Search

    Xiaohui Lei; Yuhui Wang; Yunzhong Jiang; Hao Wang; Yu Tian; Weihong Liao

    2010-01-01

    Spatially distributed hydrological model is an important tool for studying the hydrological cycle, making flood forecasting, simulating environmental and ecological processes and estimating crop water demand and so on. Successful distributed hydrological model and systems have been further achieved in many developed countries. However, there needs one GIS based Distributed Hydrological Model system to carry out hydrological simulation suitable for

  9. Flash Flood Modeling in Changing Hydrological Conditions Using a Hydrological Model and Radar Rainfall Data

    NASA Astrophysics Data System (ADS)

    Rozalis, S.; Price, C.; Yair, Y.; Morin, E.

    2009-04-01

    Flash floods are one of the most devastating natural disasters, causing much damage to property and can often lead to loss of human lives. This is a particular problem in the Mediterranean region. Understanding the meteorological and hydrological conditions for flash flood generation is an essential step on the way to forecast them and prevent some of the damage they might cause. The occurrence of a flood event is determined by meteorological conditions, producing large amounts of precipitation over a short period of time, as well as hydrological conditions, such as soil type, land cover and soil antecedent moisture conditions, which vary throughout the year and from place to place. The current study is a part of the FLASH research project (EU-FP6). In this work we use a hydrological model with data from twenty major flood events which occurred in the study area between 1991 and 2006, to better understand the role of changing hydrological and meteorological conditions in generating flash floods and in order to improve the prediction of future flash flood events. The model's runoff calculation is done by the Soil Conservation Service Curve Number method, taking into account antecedent soil moisture, land use and soil type. Runoff flow over hillslopes and channels is calculated by the Kinematic wave method. No calibration with measured flow data was performed. As rainfall data we use radar rainfall estimations adjusted to rain gauge along the basin. The model is applied over a 27 km2 basin located in a Mediterranean area in North-Eastern Israel with mean annual precipitation of about 450 mm. The main land use in this area is agriculture, with forests and orchards on the upper part and cultivated fields on its lower parts. We compare the model's runoff calculations with flow observations derived from a flow gauge located on the catchment outlet. The model allows us to explore the special synoptic, rainfall and surface conditions, responsible for the generation of these floods.

  10. Global scale hydrology - Advances in land surface modeling

    SciTech Connect

    Wood, E.F. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

    1991-01-01

    Research into global scale hydrology is an expanding area that includes researchers from the meteorology, climatology, ecology and hydrology communities. This paper reviews research in this area carried out in the United States during the last IUGG quadrennial period of 1987-1990. The review covers the representation of land-surface hydrologic processes for general circulation models (GCMs), sensitivity analysis of these representations on global hydrologic fields like precipitation, regional studies of climate that have global hydrologic implications, recent field studies and experiments whose aims are the improved understanding of land surface-atmospheric interactions, and the use of remotely sensed data for the further understanding of the spatial variability of surface hydrologic processes that are important at regional and global climate scales. 76 refs.

  11. Assessing hydrological model behaviors by intercomparison of the simulated stream flow compositions: case study in a steep forest watershed in Taiwan

    NASA Astrophysics Data System (ADS)

    Huang, J.-C.; Lee, T.-Y.; Lee, J.-Y.; Hsu, S.-C.; Kao, S.-J.; Chang, F.-J.

    2013-01-01

    The accurate stream flow composition simulated by different models is rarely discussed, and few studies addressed the model behaviors affected by the model structures. This study compared the simulated stream flow composition derived from two models, namely HBV and TOPMODEL. A total of 23 storms with a wide rainfall spectrum were utilized and independent geochemical data (to derive the stream composition using end-member mixing analysis, EMMA) were introduced. Results showed that both hydrological models generally perform stream discharge satisfactory in terms of the Nash efficiency coefficient, correlation coefficient, and discharge volume. However, the three simulated flows (surface flow, interflow, and base flow) derived from the two models were different with the change of storm intensity and duration. Both simulated surface flows showed the same patterns. The HBV simulated base flow dramatically increased with the increase of storm duration. However, the TOP-derived base flow remained stable. Meanwhile, the two models showed contrasting behaviors in the interflow. HBV prefers to generate less interflow but percolates more to the base flow to match the stream flow, which implies that this model might be suited for thin soil layer. The use of the models should consider more environmental background data into account. Compared with the EMMA-derived flows, both models showed a significant 2 to 4 h time lag, indicating that the base-flow responses were faster than the models represented. Our study suggested that model intercomparison under a wide spectrum of rainstorms and with independent validation data (geochemical data) is a good means of studying the model behaviors. Rethinking the characterization of the model structure and the watershed characteristics is necessary in selecting the more appropriate hydrological model.

  12. Hydrology

    USGS Publications Warehouse

    Eisenbies, Mark H.; Hughes, W. Brian

    2000-01-01

    Hydrologic process are the main determinants of the type of wetland located on a site. Precipitation, groundwater, or flooding interact with soil properties and geomorphic setting to yield a complex matrix of conditions that control groundwater flux, water storage and discharge, water chemistry, biotic productivity, biodiversity, and biogeochemical cycling. Hydroperiod affects many abiotic factors that in turn determine plant and animal species composition, biodiversity, primary and secondary productivity, accumulation, of organic matter, and nutrient cycling. Because the hydrologic regime has a major influence on wetland functioning, understanding how hydrologic changes influence ecosystem processes is essential, especially in light of the pressures placed on remaining wetlands by society's demands for water resources and by potential global changes in climate.

  13. Evaluating the performance in the Swedish operational hydrological forecasting systems

    NASA Astrophysics Data System (ADS)

    Pechlivanidis, Ilias; Bosshard, Thomas; Spångmyr, Henrik; Lindström, Göran; Olsson, Jonas; Arheimer, Berit

    2014-05-01

    The production of hydrological forecasts generally involves the selection of model(s) and setup, calibration and initialization, verification and updating, generation and evaluation of forecasts. Although, field data are commonly used to calibrate and initiate hydrological models, technological advancements have allowed the use of additional information, i.e. remote sensing data and meteorological ensemble forecasts, to improve hydrological forecasts. However, the precision of hydrological forecasts is often subject to uncertainty related to various components of the production chain and data used. The Swedish Meteorological and Hydrological Institute (SMHI) operationally produces hydrological medium-range forecasts in Sweden using two modeling systems based on the HBV and S-HYPE hydrological models. The hydrological forecasts use both deterministic and ensemble (in total 51 ensemble members which are further reduced to 5 statistical members; 2, 25, 50, 75, 98% percentiles) meteorological forecasts from ECMWF to add information on the uncertainty of the predicted values. In this study, we evaluate the performance of the two operational hydrological forecasting systems and identify typical uncertainties in the forecasting production chain and ways to reduce them. In particular, we investigate the effect of autoregressive updating of the forecasted discharge, and of using the median of the ensemble instead of deterministic forecasts. Medium-range (10 days) hydrological forecasts across 71 selected indicator stations are used. The Kling-Gupta Efficiency and its decomposed terms are used to analyse the performance in different characteristics of the flow signal. Results show that the HBV and S-HYPE models with AR updating are both capable of producing adequate forecasts for a short lead time (1 to 2 days), and the performance steadily decreases in lead time. The autoregressive updating method can improve the performance of the two systems by 30 to 40% in terms of the KGE. This is mainly because the method has a significant impact on the improvement of discharge volume. S-HYPE seems to perform slightly better than HBV in the longer lead time, probably because the S-HYPE system is capable of updating the lake water level, which has an impact on the longer lead times. Moreover, the deterministic and ensemble HBV systems with AR updating perform fairly similar for all lead times. Keywords: Hydrological forecasting, S-HYPE, HBV, Operational production, Kling-Gupta Efficiency, Uncertainty.

  14. Experiments with clustering of catchments in PCA-reduced space and regionalization of a hydrological model (Central Alborz region, Iran)

    NASA Astrophysics Data System (ADS)

    Khosravi, Mohammad; Solomatine, Dimitri; Salajegheh, Ali; Mohseni Saravi, Mohsen; Malekian, Arash; Corzo, Gerald

    2015-04-01

    This study tested the possibility of simulating time series of daily streamflows in ungauged catchments based on climatic and physiographic similarity. The study area is located in central Alborz region in Iran. Fourteen (14) proper catchments, with the area ranged between 16 to 827Km2, in this region selected for testing. After applying Principal Component Analysis for selecting the most important parameters among the different climatic and physiographic parameters, five components which could explain more than 90% of variances of the data were selected and according to the values of the coefficients in selected PCA components, five parameters including: Area, Annual Rainfall, Annual temperature, gravelius compactness coefficient and mean elevation, were selected as the measures for clustering. Then mentioned parameters entered in K-means clustering analysis method to classify the catchments. Finally the catchments divided in three different clusters. Using the well known HBV model, we built a model for the closest catchment to the center of each cluster. Then, the thirteen (13) HBV model parameters were calibrated using Genetic Algorithm. We assumed that the remained catchments in each cluster are ungauged, and using the calibrated model, the daily time series of streamflows simulated in the remained catchments in the considered cluster (as the receiver catchments). Nash Sutcliffe and RMSE indices used to comparing the simulated and recorded data. The experiments with the considered case study confirmed that the model regionalization based on the physiographic and climatic characteristics could be a useful instrument in hydrological studies. Key words: Regionalization, HBV, PCA, Cluster, Catchment, central Alborz region

  15. From local hydrological process analysis to regional hydrological model application in Benin: Concept, results and perspectives

    NASA Astrophysics Data System (ADS)

    Bormann, H.; Faß, T.; Giertz, S.; Junge, B.; Diekkrüger, B.; Reichert, B.; Skowronek, A.

    This paper presents the concept, first results and perspectives of the hydrological sub-project of the IMPETUS-Benin project which is part of the GLOWA program funded by the German ministry of education and research. In addition to the research concept, first results on field hydrology, pedology, hydrogeology and hydrological modelling are presented, focusing on the understanding of the actual hydrological processes. For analysing the processes a 30 km 2 catchment acting as a super test site was chosen which is assumed to be representative for the entire catchment of about 15,000 km 2. First results of the field investigations show that infiltration, runoff generation and soil erosion strongly depend on land cover and land use which again influence the soil properties significantly. A conceptual hydrogeological model has been developed summarising the process knowledge on runoff generation and subsurface hydrological processes. This concept model shows a dominance of fast runoff components (surface runoff and interflow), a groundwater recharge along preferential flow paths, temporary interaction between surface and groundwater and separate groundwater systems on different scales (shallow, temporary groundwater on local scale and permanent, deep groundwater on regional scale). The findings of intensive measurement campaigns on soil hydrology, groundwater dynamics and soil erosion have been integrated into different, scale-dependent hydrological modelling concepts applied at different scales in the target region (upper Ouémé catchment in Benin, about 15,000 km 2). The models have been applied and successfully validated. They will be used for integrated scenario analyses in the forthcoming project phase to assess the impacts of global change on the regional water cycle and on typical problem complexes such as food security in West African countries.

  16. Techniques for estimating impervious surface cover in hydrologic modelling

    Microsoft Academic Search

    Steven Roso

    2007-01-01

    Due to their low infiltration rates, impervious surfaces generate large amounts of runoff. This runoff usually has high concentrations of pollutants. The impervious surface cover on a catchment therefore has a significant effect on catchment hydrology and water quality. This makes estimates of impervious surfaces critical when preparing hydrologic models of urban catchments. It could be expected that such measurements

  17. Application of regional climate data as input for hydrological modelling

    Microsoft Academic Search

    J. Sennikovs; A. Timuhins

    2009-01-01

    The goal of this study was to check the suitability of application of regional climate model (RCM) forcing data for hydrological modelling. The spatially distributed finite volume based hydrological model was set-up for the pilot basin in central Latvia (river Aiviekste, catchment area 9300 sq.km). The primary forcing input for the model consists of the time-series of temperature and precipitation.

  18. Incorporating hydraulic/hydromorphologic properties and their stage dependency into hydrologic compartmental models

    NASA Astrophysics Data System (ADS)

    Gustafsson, A.; Wörman, A.

    2009-04-01

    According to recent studies, the volumetric error of the predicted size of the spring flood in Sweden can be as large as 20%. A significant part of this error originates from simplifications in the spatial and hydrodynamic description of watercourse networks, as well as statistical problems to give proper weight to extreme flows. Possible ways to improve current hydrological modelling practises is by making models more adapted to varying flow conditions as well as by increasing the coupling between model parameters and physical catchment characteristics. This study formulates a methodology based in hydrodynamical/hydraulic theory to investigate how river network characteristics vary with flow stage and how to transfer this information to compartmental hydrologic models such as the HBV/HYPE models. This is particularly important during extreme flows when a significant portion of the water flows outside the normal stream channels. The aim is to combine knowledge about the hydrodynamics and hydro-morphology of watercourse networks to improve the predictions of peak flows. HYPE is a semi-distributed conceptual compartmental hydrological model which is currently being developed at the SMHI as a successor to the HBV model. The model (HYPE) is thought to be better adapted to varying flow conditions by using the dynamical response functions derived by the methodology described here. The distribution of residence times within the watercourse network - and how these depend on flow stage is analysed. This information is then incorporated into the response functions of the HYPE model, i.e. the compartmental model receives a dynamic transformation function relating river discharge to storativity within the sub-catchment. This response function hence reflects the topologic and hydromorphologic characteristics of the watercourse network as well as flow stage. Seven subcatchments in Rönne River basin (1900 km2) are studied to show how this approach can improve the prediction of peak flows. For the watercourse network analysis, two types of 1-D distributed network models are set up. One model contains a simplified hydraulic analysis of the watercourse network and how its properties vary with flow stage; the other network model is a numerical (stationary) routing routine. In the simplified hydraulic model, the effect of changed cross-sectional geometries is analysed. The focus is put on extreme flows with flooded cross-sections, where the hydromorphological properties of the network are changed considerably. By usage of the Manning equation, residence times are calculated for different flow stages. The second network model is used to numerically investigate the effects of the routing through each sub-catchment. Probability density functions of residence times are calculated for a range of flow stages to obtain subcatchment-specific information which incorporates the effects of flow stage and changed cross-sectional geometries. This information is thereafter used as response functions in the compartmental model which then will be more adapted to the effects of flooded cross-sections. Both network models are based on continuity principles regarding mass, energy and momentum. In both models, stationary flow conditions within the watercourse network are assumed, an assumption that might not be valid during extreme flows. In the simplified hydraulic model, the flow is assumed to be uniform between computational nodes - hence allowing the usage of the Manning equation for calculations of travelling times. The statements mentioned above are considered as possible sources of errors, however, more effort will be put into minimizing these effects, for example by finding optimal resolutions in space and time. The compartmental model and the network models are defined on a comparable form to facilitate the transfer of information between the models. Within the compartmental model, the streamflow component is separated from the remaining flows, since the network models only regard the attenuation in the stream channel. Parameters (derived from the si

  19. ENHANCING HYDROLOGICAL SIMULATION PROGRAM - FORTRAN MODEL CHANNEL HYDRAULIC REPRESENTATION

    EPA Science Inventory

    The Hydrological Simulation Program? FORTRAN (HSPF) is a comprehensive watershed model that employs depth-area - volume - flow relationships known as the hydraulic function table (FTABLE) to represent the hydraulic characteristics of stream channel cross-sections and reservoirs. ...

  20. Coupling Quantitative Precipitation Estimate and Great Lakes Hydrologic Models

    E-print Network

    Coupling Quantitative Precipitation Estimate and Great Lakes Hydrologic Models Primary Investigator responsible for changes in the Great Lakes aquatic ecosystem; rainfall and associated run-off are those Severe Storms Laboratory (NSSL) and the Great Lakes Environmental Research Laboratory (GLERL

  1. Doing hydrology forwards: Using field experimental data to inform a conceptual model of landscape driven hydrologic connectivity

    NASA Astrophysics Data System (ADS)

    Marshall, L. A.; Smith, T. J.; McGlynn, B. L.; Jencso, K. G.

    2011-12-01

    Given the known tradeoffs between hydrologic model complexity, efficiency, and predictive uncertainty there is an increasing desire to identify conceptual catchment models that accurately reflect catchment processes whilst preserving model identifiability. These models should specify the relationship between catchment form (including landscape topography, vegetation patterns, and stream networks) and hydrologic functioning (including streamflow patterns). We present a new hydrologic modeling approach that uses the distribution of landscape elements along the stream network as a template by which landscape-scale hydrologic connectivity and catchment runoff can be simulated. Here, we define hydrologic connectivity as the transient hydrological linkages between landscape elements and the stream. Our conceptualization emphasizes the importance of hydrologic connections between hillslope-riparian-stream (HRS) zones. Observations indicate that it is the frequency of these HRS hydrologic connections that drive aggregate catchment runoff response, rather than the magnitude of flux at any one connection. We applied the model to the Stringer Creek watershed of the Tenderfoot Creek Experimental Forest (TCEF), located in central Montana, USA. Detailed field observations were used to inform the underpinnings of the model and to corroborate internal consistency of the model's simulations. The ability of the model to simulate internal dynamics without conditioning the parameters on these data indicate the potential of this model to be more convincingly extrapolated to other hydrologic conditions and tested at catchments of varying topographic structure. Current and future work is aimed at further developing the modeling approach and testing the limits of its applicability across space and time.

  2. Assessing Hydrological Extreme Events with Geospatial Data and Models

    NASA Astrophysics Data System (ADS)

    Vivoni, Enrique R.; Grimaldi, Salvatore; Nardi, Fernando; Ivanov, Valeriy Y.; Castelli, Fabio; Bras, Rafael L.; Ubertini, Lucio

    2004-09-01

    Prediction of river basin hydrological response to extreme meteorological events is a primary concern in areas with frequent flooding, landslides, and debris flows. Natural hydrogeological disasters in many regions lead to extensive property damage, impact on societal activities, and loss of life. Hydrologists have a long history of assessing and predicting hydrologic hazards through the combined use of field observations, monitoring networks, remote sensing, and numerical modeling. Nevertheless, the integration of field data and computer models has yet to result in prediction systems that capture space-time interactions between meteorological forcing, land surface characteristics, and the internal hydrological response in river basins. Capabilities for assessing hydrologic extreme events are greatly enhanced via the use of geospatial data sets describing watershed properties such as topography, channel structure, soils, vegetation, and geological features. Recent advances in managing, processing, and visualizing cartographic data with geographic information systems (GIS) have enabled their direct use in spatially distributed hydrological models. In a distributed model application, geospatial data sets can be used to establish the model domain, specify boundary and initial conditions, determine the spatial variation of parameter values, and provide the spatial model forcing. By representing a watershed through a set of discrete elements, distributed models simulate water, energy, and mass transport in a landscape and provide estimates of the spatial pattern of hydrologic states, fluxes, and pathways.

  3. Hydrological Modeling of the Jiaoyi Watershed (China) Using HSPF Model

    PubMed Central

    Yan, Chang-An; Zhang, Wanchang; Zhang, Zhijie

    2014-01-01

    A watershed hydrological model, hydrological simulation program-Fortran (HSPF), was applied to simulate the spatial and temporal variation of hydrological processes in the Jiaoyi watershed of Huaihe River Basin, the heaviest shortage of water resources and polluted area in China. The model was calibrated using the years 2001–2004 and validated with data from 2005 to 2006. Calibration and validation results showed that the model generally simulated mean monthly and daily runoff precisely due to the close matching hydrographs between simulated and observed runoff, as well as the excellent evaluation indicators such as Nash-Sutcliffe efficiency (NSE), coefficient of correlation (R2), and the relative error (RE). The similar simulation results between calibration and validation period showed that all the calibrated parameters had a certain representation in Jiaoyi watershed. Additionally, the simulation in rainy months was more accurate than the drought months. Another result in this paper was that HSPF was also capable of estimating the water balance components reasonably and realistically in space through the whole watershed. The calibrated model can be used to explore the effects of climate change scenarios and various watershed management practices on the water resources and water environment in the basin. PMID:25013863

  4. New insights for the hydrology of the Rhine based on the new generation climate models

    NASA Astrophysics Data System (ADS)

    Bouaziz, Laurène; Sperna Weiland, Frederiek; Beersma, Jules; Buiteveld, Hendrik

    2014-05-01

    Decision makers base their choices of adaptation strategies on climate change projections and their associated hydrological consequences. New insights of climate change gained under the new generation of climate models belonging to the IPCC 5th assessment report may influence (the planning of) adaption measures and/or future expectations. In this study, hydrological impacts of climate change as projected under the new generation of climate models for the Rhine were assessed. Hereto we downscaled 31 General Circulation Models (GCMs), which were developed as part of the Coupled Model Intercomparison Project Phase 5 (CMIP5), using an advanced Delta Change Method for the Rhine basin. Changes in mean monthly, maximum and minimum flows at Lobith were derived with the semi-distributed hydrological model HBV of the Rhine. The projected changes were compared to changes that were previously obtained in the trans-boundary project Rheinblick using eight CMIP3 GCMs and Regional Climate Models (RCMs) for emission scenario A1B. All eight selected CMIP3 models (scenario A1B) predicted for 2071-2100 a decrease in mean monthly flows between June and October. Similar decreases were found for some of the 31 CMIP5 models for Representative Concentration Pathways (RCPs) 4.5, 6.0 and 8.5. However, under each RCP, there were also models that projected an increase in mean flows between June and October and on average the decrease was smaller than for the eight CMIP3 models. For 2071-2100, also the mean annual minimum 7-days discharge decreased less in the CMIP5 model simulations than was projected in CMIP3. When assessing the response of mean monthly flows of the CMIP5 simulation with the CSIRO-Mk3-6-0 and HadGEM2-ES models with respect to initial conditions and RCPs, it was found that natural variability plays a dominant role in the near future (2021-2050), while changes in mean monthly flows are dominated by the radiative forcing in the far future (2071-2100). According to RCP 8.5 model simulations, the change in mean monthly flow from May to November may be half the change in mean monthly flow projected by RCP 4.5. From January to March, RCP 8.5 simulations projected higher changes in mean monthly flows than RCP 4.5 simulations. These new insights based on the CMIP5 simulations imply that for the Rhine, the mean and low flow extremes might not decrease as much in summer as was expected under CMIP3. Stresses on water availability during summer are therefore also less than expected from CMIP3.

  5. The model of the water balance and nutrient uptake as a basis for hydrological, agro-hydrological and other projects

    Microsoft Academic Search

    W. C. Visser

    models. The hydrological model can best be based on the water balance, which is a consequence of the law of conservation of matter. The agro-hydrological model is based on the diffusion equation, which leads to the law of limiting factors. The importance of these models is that the underlying principles are generally accepted. Further a wide range of processes can

  6. Hydrological minimal model for fire regime assessment in Mediterranean ecosystem

    NASA Astrophysics Data System (ADS)

    Ursino, N.; Rulli, M.

    2011-12-01

    A new model for Mediterranean forest fire regime assessment is presented and discussed. The model is based on the experimental evidence that fire is due to both hydrological and ecological processes and that the relative role of fuel load versus fuel moisture is an important driver in fire ecology. Diverse scenarios are analyzed where either the hydrological forcing or the feedback between fire and hydrological characterization of the site is changed. The model outcome demonstrates that the two way interaction between hydrological processes, biology and fire regime drives the ecosystem toward a typical fire regime that may be altered either by an evolution of the biological characterization of the site or by a change of the hydrological forcing. This tenet implies that not every fire regime is compatible with the ecohydrological characterization of the site under study. This means that natural (non human caused) fire cannot be modeled as an arbitrary external forcing because the coupled hydrological and biological processes determines its statistical characterization, and conversely, the fire regime affects the soil moisture availability and the outcome of different species competition under possible water stress. The new modeling approach here presented, when provided by a proper model parameterization, can be able to advance the capability in predicting and managing fires in ecosystems influenced by climate and land use changes.

  7. Hydrological minimal model for fire regime assessment in Mediterranean ecosystem

    NASA Astrophysics Data System (ADS)

    Ursino, N.; Rulli, M. C.

    2012-04-01

    A new model for Mediterranean forest fire regime assessment is presented and discussed. The model is based on the experimental evidence that fire is due to both hydrological and ecological processes and the relative role of fuel load versus fuel moisture is an important driver in fire ecology. Diverse scenarios are analyzed where either the hydrological forcing or the feedback between fire and hydrological characterization of the site is changed. The model outcome demonstrates that the two way interaction between hydrological processes, biology and fire regime drives the ecosystem toward a typical fire regime that may be altered either by an evolution of the biological characterization of the site or by a change of the hydrological forcing. This tenet implies that not every fire regime is compatible with the ecohydrological characterization of the site under study. This means that natural (non antropogenic) fire cannot be modeled as an arbitrary external forcing because the coupled hydrological and biological processes determines its statistical characterization, and conversely, the fire regime affects the soil moisture availability and the outcome of different species competition under possible water stress. The new modelling approach presented here, when provided by a proper model parameterization, can advance the capability in predicting and managing fires in ecosystems influenced by climate and land use changes.

  8. Rapid Post Fire Hydrologic Watershed Assessment using the AGWA GIS -based Hydrologic Modeling Tool

    Microsoft Academic Search

    D. C. Goodrich; H. Evan Canfield; I. Shea Burns; D. J. Semmens; S. N. Miller; M. Hernandez; L. R. Levick; D. P. Guertin; W. G. Kepner

    Rapid post -fire watershed assessment to identify potential trouble spots for erosion and flooding can potentially aid land managers and Bu rned Area Emergency Rehabilitation (BAER) teams in deploying mitigation and rehabilitation resources. These decisions are inherently complex and spatial in nature and require a distributed hydrological modeling approach. The extensive data requirements an d the task of building input

  9. Evaluation of a typical hydrological model in relation to environmental flows

    NASA Astrophysics Data System (ADS)

    Olsen, Martin; Troldborg, Lars; Henriksen, Hans Joergen; Conallin, John; Refsgaard, Jens Christian; Boegh, Eva

    2013-12-01

    A Critical-Flow-Calendar is produced linking ecology and hydrology.The hydrological models are tested for the period where flow criteria are critical.Flow criteria should be selected so they can be simulated by the hydrological model.The hydrological model should be tailored to simulate the relevant flows.

  10. Climate noise effect on uncertainty of hydrological extremes: numerical experiments with hydrological and climate models

    NASA Astrophysics Data System (ADS)

    Gelfan, A. N.; Semenov, V. A.; Motovilov, Yu. G.

    2015-06-01

    An approach has been proposed to analyze the simulated hydrological extreme uncertainty related to the internal variability of the atmosphere ("climate noise"), which is inherent to the climate system and considered as the lowest level of uncertainty achievable in climate impact studies. To assess the climate noise effect, numerical experiments were made with climate model ECHAM5 and hydrological model ECOMAG. The case study was carried out to Northern Dvina River basin (catchment area is 360 000 km2), whose hydrological regime is characterised by extreme freshets during spring-summer snowmelt period. The climate noise was represented by ensemble ECHAM5 simulations (45 ensemble members) with identical historical boundary forcing and varying initial conditions. An ensemble of the ECHAM5-outputs for the period of 1979-2012 was used (after bias correction post-processing) as the hydrological model inputs, and the corresponding ensemble of 45 multi-year hydrographs was simulated. From this ensemble, we derived flood statistic uncertainty caused by the internal variability of the atmosphere.

  11. Hydrologic Modeling Strategy for the Islamic Republic of Mauritania, Africa

    USGS Publications Warehouse

    Friedel, Michael J.

    2008-01-01

    The government of Mauritania is interested in how to maintain hydrologic balance to ensure a long-term stable water supply for minerals-related, domestic, and other purposes. Because of the many complicating and competing natural and anthropogenic factors, hydrologists will perform quantitative analysis with specific objectives and relevant computer models in mind. Whereas various computer models are available for studying water-resource priorities, the success of these models to provide reliable predictions largely depends on adequacy of the model-calibration process. Predictive analysis helps us evaluate the accuracy and uncertainty associated with simulated dependent variables of our calibrated model. In this report, the hydrologic modeling process is reviewed and a strategy summarized for future Mauritanian hydrologic modeling studies.

  12. The Use of Landscape Variability in the mesoscale Hydrologic Model

    NASA Astrophysics Data System (ADS)

    Nijzink, Remko C.; Hrachowitz, Markus; Samaniego, Luis; Savenije, Hubert H. G.

    2015-04-01

    Dealing with catchment heterogeneity remains an important issue in hydrological modelling. One way to deal with catchment heterogeneity is by subdividing the catchment into smaller representative watersheds, like Reggiani et al (1998). In line with this, Savenije (2010) proposed a modelling set-up where different landscape units get different model structures. Every unit describes in this way the dominant processes in the landscape. However, transferring the model to other catchments without recalibration is still hard. The mesoscale Hydrologic Model (mHM; Samaniego(2010)) is a distributed model which was proven to be transferable to other regions, due to the used regionalization technique. Nevertheless, the mHM model uses a single model structure (the configuration of states and fluxes in the model), which may not describe the hydrological processes correctly. The mHM model has been equipped with a more complex model structure based on topography in order to obtain a transferable and realistic model. Three landscape classes have been defined based on the Height Above Nearest Drainage (HAND) and terrain slope. These three landscape classes each have a different model structure. The new model, mHMtopo, has been compared with the original mHM after calibration of both models with a Monte Carlo approach. A number of hydrological characteristics (signatures) were used to determine which model showed the best representation of reality. Afterwards, the transferability was tested by a simultaneous calibration of four different catchments and a validation in four other catchments.

  13. Modelling floods in hydrologically complex lowland river reaches

    NASA Astrophysics Data System (ADS)

    Stewart, M. D.; Bates, P. D.; Anderson, M. G.; Price, D. A.; Burt, T. P.

    1999-09-01

    This paper considers the modelling of lowland river reaches which contain complex within-reach hydrological interactions. It is clear that river and floodplain flow are the most important processes in terms of flood modelling in lowland systems, although there are often important lateral inflows from catchments and hillslopes bounding the floodplain and from interactions between the river and the floodplain, which can all affect the propagation of the flood wave. Previous models have often either considered a complex representation of the fluvial processes with no representation of the hydrological inflows into the reach (Bates, P.D., Anderson, M.G., Price, D.A., Hardy, R.J., Smith, C.N., 1996. Analysis and development of hydraulic models for floodplain flows. In: Anderson, M.G., Walling, D.E., Bates P.D. (Eds.), Floodplain Processes. Wiley, Chichester, pp. 215-254), or have simulated a range of catchment processes with a poor representation of the river and floodplain (Abbot, M.B., Bathurst, J.C., Cunge, J.A., O'Connell, P.E., Rasmussen, J., 1986. An introduction to the European Hydrological System—Système Hydrologique Européen, SHE, 2. Structure of a physically based, distributed modelling system. Journal of Hydrology, 87, 61-77). Hence, this paper develops a modelling approach based on a two-dimensional finite element hydraulic model of river and floodplain flow, which is linked to a series of simple hydrological models that simulate catchment runoff, surface and subsurface hillslope runoff, and floodplain infiltration. Simulations show that the model is able to predict flood hydrographs for a series of flood events, under a range of different hydrological conditions, down a reach of the River Severn, UK. Furthermore, the comparison of results from simulations using hydrological representations of different degrees of complexity suggest that there are restrictions on the necessary complexity of the hydrological components depending on the application of the model and the available validation data. Simple approaches to the reach scale hydrology may be sufficient if only the bulk outflow hydrograph is required by the user, however more complex spatially and temporally distributed models appear to be required if predictions of the flood inundation extent are desired. The simulations raise the issue of the application of distributed models and attempt to provide a framework for future research. The results suggest that there is a need for the validation of the internal predictions of distributed models of flood flow, and suggests a need for field data of river and floodplain interactions within long lowland river reaches.

  14. Strategies for using remotely sensed data in hydrologic models

    NASA Technical Reports Server (NTRS)

    Peck, E. L.; Keefer, T. N.; Johnson, E. R. (principal investigators)

    1981-01-01

    Present and planned remote sensing capabilities were evaluated. The usefulness of six remote sensing capabilities (soil moisture, land cover, impervious area, areal extent of snow cover, areal extent of frozen ground, and water equivalent of the snow cover) with seven hydrologic models (API, CREAMS, NWSRFS, STORM, STANFORD, SSARR, and NWSRFS Snowmelt) were reviewed. The results indicate remote sensing information has only limited value for use with the hydrologic models in their present form. With minor modifications to the models the usefulness would be enhanced. Specific recommendations are made for incorporating snow covered area measurements in the NWSRFS Snowmelt model. Recommendations are also made for incorporating soil moisture measurements in NWSRFS. Suggestions are made for incorporating snow covered area, soil moisture, and others in STORM and SSARR. General characteristics of a hydrologic model needed to make maximum use of remotely sensed data are discussed. Suggested goals for improvements in remote sensing for use in models are also established.

  15. A sensitivity analysis of regional and small watershed hydrologic models

    NASA Technical Reports Server (NTRS)

    Ambaruch, R.; Salomonson, V. V.; Simmons, J. W.

    1975-01-01

    Continuous simulation models of the hydrologic behavior of watersheds are important tools in several practical applications such as hydroelectric power planning, navigation, and flood control. Several recent studies have addressed the feasibility of using remote earth observations as sources of input data for hydrologic models. The objective of the study reported here was to determine how accurately remotely sensed measurements must be to provide inputs to hydrologic models of watersheds, within the tolerances needed for acceptably accurate synthesis of streamflow by the models. The study objective was achieved by performing a series of sensitivity analyses using continuous simulation models of three watersheds. The sensitivity analysis showed quantitatively how variations in each of 46 model inputs and parameters affect simulation accuracy with respect to five different performance indices.

  16. Groundwater level simulations using a mesoscale hydrological model SWIM

    NASA Astrophysics Data System (ADS)

    Sipek, Vaclav

    2013-04-01

    Integrated water resources management based on the profound understanding of the hydrological cycle may be a suitable tool for alleviating the upcoming water resource crisis. The application of the physically based distributed hydrological models is a significant tool for studies of hydrological behavior of river basins under the change of natural condition and. The SWIM (Soil and Water Integrated Model) is physically based hydrological models that could be used for impact studies. It is a continuous-time model which works on a daily step and integrates hydrology, vegetation, erosion and nutrients (N-nitrogen and P-phosphorus) at the river basin scale. Its hydrological module is based on the water balance equation, taking into account precipitation, evapotranspiration, percolation, surface runoff and subsurface runoff for the soil column subdivided into several layers. The catchment is spatially subdivided into hydrotops (or hydrologically similar response units) by GIS. The aim of this study was to examine the ability of this type of the model to simulate the course of the groundwater level in the mesoscale catchment in the Czech Republic. The weekly values of the groundwater table height were compared to the simulated ones at several uniformly distributed locations. In one particular site, the results were also discussed in the context of the soil moisture content. It was found that in the warm period of the year the model is able to simulate satisfactorily both the course of groundwater and soil moisture. Nevertheless, in the winter season the rate of percolation is probably underestimated as the simulated groundwater height is lower than observed and at the same time the soil moisture content is overestimated. Acknowledgement: The study was supported by the research grant GA AS CR IAA 300600901

  17. Flood and inundation evaluation using a GIS based hydrological model

    NASA Astrophysics Data System (ADS)

    Chang, J.; Gong, C.; Wen, J.

    2008-12-01

    In this paper, the SOBEK model was used which combines the function of a one-dimensional channel flow and a two-dimensional overland flow to analyze and present the flood potential of the Hsin-Huwei Creek basin in Taiwan. In the article, the methodology illustrated involved integrating the DTM data and hydrologic data, calibrating both hydrologic and hydraulic models, and producing inundation maps directly usable for planning of flood-prone areas. The GIS was used to perform the tedious and time-consuming tasks of spatial analysis for the 5 m × 5 m resolution DTM data. Using real rainfall data with observed channel stages, the parameters of the model were calibrated. The model was finally used for inundation simulation, and the results were used for inspecting the flood control facilities and drainage systems to reduce flood threats. Keywords Inundation evaluation, GIS, Hydrological model

  18. Hydrological Response to Climate Change over the Blue Nile Basin Distributed hydrological modeling based on surrogate climate change scenarios

    Microsoft Academic Search

    F. G. Berhane; R. O. Anyah

    2010-01-01

    Abstract The program Soil and Water Assessment Tool (SWAT2009) model has been applied to the Blue Nile Basin to study the hydrological response to surrogate climate changes over the Blue Nile Basin (Ethiopia) by downscaling gridded weather data. The specific objectives of the study include (i) examining the performance of the SWAT model in simulating hydrology-climate interactions and feedbacks within

  19. Genetic Algorithm Optimization of Artificial Neural Networks for Hydrological Modelling

    Microsoft Academic Search

    R. J. Abrahart

    2004-01-01

    This paper will consider the case for genetic algorithm optimization in the development of an artificial neural network model. It will provide a methodological evaluation of reported investigations with respect to hydrological forecasting and prediction. The intention in such operations is to develop a superior modelling solution that will be: \\\\begin{itemize} more accurate in terms of output precision and model

  20. Satellite-derived potential evapotranspiration for distributed hydrologic runoff modeling

    NASA Astrophysics Data System (ADS)

    Spies, R. R.; Franz, K. J.; Bowman, A.; Hogue, T. S.; Kim, J.

    2012-12-01

    Distributed models have the ability of incorporating spatially variable data, especially high resolution forcing inputs such as precipitation, temperature and evapotranspiration in hydrologic modeling. Use of distributed hydrologic models for operational streamflow prediction has been partially hindered by a lack of readily available, spatially explicit input observations. Potential evapotranspiration (PET), for example, is currently accounted for through PET input grids that are based on monthly climatological values. The goal of this study is to assess the use of satellite-based PET estimates that represent the temporal and spatial variability, as input to the National Weather Service (NWS) Hydrology Laboratory Research Distributed Hydrologic Model (HL-RDHM). Daily PET grids are generated for six watersheds in the upper Mississippi River basin using a method that applies only MODIS satellite-based observations and the Priestly Taylor formula (MODIS-PET). The use of MODIS-PET grids will be tested against the use of the current climatological PET grids for simulating basin discharge. Gridded surface temperature forcing data are derived by applying the inverse distance weighting spatial prediction method to point-based station observations from the Automated Surface Observing System (ASOS) and Automated Weather Observing System (AWOS). Precipitation data are obtained from the Climate Prediction Center's (CPC) Climatology-Calibrated Precipitation Analysis (CCPA). A-priori gridded parameters for the Sacramento Soil Moisture Accounting Model (SAC-SMA), Snow-17 model, and routing model are initially obtained from the Office of Hydrologic Development and further calibrated using an automated approach. The potential of the MODIS-PET to be used in an operational distributed modeling system will be assessed with the long-term goal of promoting research to operations transfers and advancing the science of hydrologic forecasting.

  1. Calibration of a Hydrological Model using Ensemble Satellite Rainfall Inputs

    NASA Astrophysics Data System (ADS)

    Skinner, Christopher; Bellerby, Timothy

    2014-05-01

    A combination of satellite rainfall estimates (SRFE) and hydrological models can provide useful information for many remote areas of the planet. However, each component contains its own uncertainties and these uncertainties will interact when SRFE are used as inputs for hydrological models. For any assessment of a coupled system such as this there is a requirement for a comprehensive analysis of all sources of uncertainty, with full consideration of both facets. SRFE have been shown to be useful in many areas that lack the infrastructure to make timely and accurate estimations of rainfall from the ground. Sub-Saharan Africa is typical of this, where a paucity of rain recording radar and sparse gauging networks combine with a highly variable climate and a reliance on rain-fed agriculture. When operating at higher spatial and temporal resolutions, SRFE contain large uncertainties which will propagate through a hydrological model if used as a driving input. This study used a sequential method to produce ensemble SRFE based around the full conditional distribution of recorded rainfall from a sparse, historic raingauge network. The TAMSIM method (introduced by Teo, 2006) was used to produce 200 unique yet equiprobable SRFE, each used as a driver to a downstream hydrological model. Traditional hydrological modelling uses the adjustment of variable parameters within the model to reduce the error between a recorded record of discharge and the modelled one, and many automatic procedures have been produced to refine this calibration process. When SRFE have been used as a driver, little consideration has been paid to this process and often a calibration using the raingauge data has been used, without any consideration to the resulting uncertainty within the hydrological model and its calibration. A similar issue arises when ensemble inputs are used to a hydrological model that has been calibrated using a deterministic estimate of rainfall. This study has shown that such approaches are not suitable for use with ensemble SRFE inputs, and that a calibration approach that incorporates each ensemble input individually and as a whole is required. Finally, the study showed that temporal biases within the SRFE, due to interannual variations of the seasonal rainfall, were directly transferred to the biases in the modelled discharges, yet spatial biases, due to climatic variations across the catchment, where compensated for by the automatic calibration of the hydrological model.

  2. WEB-DHM: A distributed biosphere hydrological model developed by coupling a simple biosphere scheme with a hillslope hydrological model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The coupling of land surface models and hydrological models potentially improves the land surface representation, benefiting both the streamflow prediction capabilities as well as providing improved estimates of water and energy fluxes into the atmosphere. In this study, the simple biosphere model 2...

  3. Comparing spatial and temporal transferability of hydrological model parameters

    NASA Astrophysics Data System (ADS)

    Patil, Sopan D.; Stieglitz, Marc

    2015-06-01

    Operational use of hydrological models requires the transfer of calibrated parameters either in time (for streamflow forecasting) or space (for prediction at ungauged catchments) or both. Although the effects of spatial and temporal parameter transfer on catchment streamflow predictions have been well studied individually, a direct comparison of these approaches is much less documented. Here, we compare three different schemes of parameter transfer, viz., temporal, spatial, and spatiotemporal, using a spatially lumped hydrological model called EXP-HYDRO at 294 catchments across the continental United States. Results show that the temporal parameter transfer scheme performs best, with lowest decline in prediction performance (median decline of 4.2%) as measured using the Kling-Gupta efficiency metric. More interestingly, negligible difference in prediction performance is observed between the spatial and spatiotemporal parameter transfer schemes (median decline of 12.4% and 13.9% respectively). We further demonstrate that the superiority of temporal parameter transfer scheme is preserved even when: (1) spatial distance between donor and receiver catchments is reduced, or (2) temporal lag between calibration and validation periods is increased. Nonetheless, increase in the temporal lag between calibration and validation periods reduces the overall performance gap between the three parameter transfer schemes. Results suggest that spatiotemporal transfer of hydrological model parameters has the potential to be a viable option for climate change related hydrological studies, as envisioned in the "trading space for time" framework. However, further research is still needed to explore the relationship between spatial and temporal aspects of catchment hydrological variability.

  4. Strategies to eliminate HBV infection.

    PubMed

    Kapoor, Rama; Kottilil, Shyam

    2014-01-01

    Chronic HBV infection is a major public health concern affecting over 240 million people worldwide. Although suppression of HBV replication is achieved in the majority of patients with currently available newer antivirals, discontinuation of therapy prior to hepatitis B surface antigen loss or seroconversion is associated with relapse of HBV in the majority of cases. Thus, new therapeutic modalities are needed to achieve eradication of the virus from chronically infected patients in the absence of therapy. The basis of HBV persistence includes viral and host factors. Here, we review novel strategies to achieve sustained cure or elimination of HBV. The novel approaches include targeting the viral and or host factors required for viral persistence, and novel immune-based therapies, including therapeutic vaccines. PMID:25309617

  5. Hydrologic and water quality teminology as applied to modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A survey of literature and examination in particular of terminology use in a previous special collection of modeling calibration and validation papers has been conducted to arrive at a list of consistent terminology recommended for writing about hydrologic and water quality model calibration and val...

  6. Application of environmental models to different hydrological systems

    Microsoft Academic Search

    A. Ghosh Bobba; Vijay P. Singh; Lars Bengtsson

    2000-01-01

    In recent years global problems such as climatic change, acid rain, and water pollution in surface and subsurface environments dominate discussions of world environmental problems. In this paper, the roles of hydrologic processes and hydrogeochemical processes are investigated through development, modification, and application of mathematical models for addressing point and non-point source water quality modelling of receiving waters: surface water,

  7. A fully integrated SWAT-MODFLOW hydrologic model

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  8. Use of hydrologic and hydrodynamic modeling for ecosystem restoration

    USGS Publications Warehouse

    Obeysekera, J.; Kuebler, L.; Ahmed, S.; Chang, M.-L.; Engel, V.; Langevin, C.; Swain, E.; Wan, Y.

    2011-01-01

    Planning and implementation of unprecedented projects for restoring the greater Everglades ecosystem are underway and the hydrologic and hydrodynamic modeling of restoration alternatives has become essential for success of restoration efforts. In view of the complex nature of the South Florida water resources system, regional-scale (system-wide) hydrologic models have been developed and used extensively for the development of the Comprehensive Everglades Restoration Plan. In addition, numerous subregional-scale hydrologic and hydrodynamic models have been developed and are being used for evaluating project-scale water management plans associated with urban, agricultural, and inland costal ecosystems. The authors provide a comprehensive summary of models of all scales, as well as the next generation models under development to meet the future needs of ecosystem restoration efforts in South Florida. The multiagency efforts to develop and apply models have allowed the agencies to understand the complex hydrologic interactions, quantify appropriate performance measures, and use new technologies in simulation algorithms, software development, and GIS/database techniques to meet the future modeling needs of the ecosystem restoration programs. Copyright ?? 2011 Taylor & Francis Group, LLC.

  9. Brokering as a framework for hydrological model repeatability

    NASA Astrophysics Data System (ADS)

    Fuka, Daniel; Collick, Amy; MacAlister, Charlotte; Braeckel, Aaron; Wright, Dawn; Jodha Khalsa, Siri; Boldrini, Enrico; Easton, Zachary

    2015-04-01

    Data brokering aims to provide those in the the sciences with quick and repeatable access to data that represents physical, biological, and chemical characteristics; specifically to accelerate scientific discovery. Environmental models are useful tools to understand the behavior of hydrological systems. Unfortunately, parameterization of these hydrological models requires many different data, from different sources, and from different disciplines (e.g., atmospheric, geoscience, ecology). In basin scale hydrological modeling, the traditional procedure for model initialization starts with obtaining elevation models, land-use characterizations, soils maps, and weather data. It is often the researcher's past experience with these datasets that determines which datasets will be used in a study, and often newer, or more suitable data products will exist. An added complexity is that various science communities have differing data formats, storage protocols, and manipulation methods, which makes use by a non native user exceedingly difficult and time consuming. We demonstrate data brokering as a means to address several of these challenges. We present two test case scenarios in which researchers attempt to reproduce hydrological model results using 1) general internet based data gathering techniques, and 2) a scientific data brokering interface. We show that data brokering can increase the efficiency with which data are obtained, models are initialized, and results are analyzed. As an added benefit, it appears brokering can significantly increase the repeatability of a given study.

  10. Neural Networks for Hydrological Modeling Tool for Operational Purposes

    NASA Astrophysics Data System (ADS)

    Bhatt, Divya; Jain, Ashu

    2010-05-01

    Hydrological models are useful in many water resources applications such as flood control, irrigation and drainage, hydro power generation, water supply, erosion and sediment control, etc. Estimates of runoff are needed in many water resources planning, design development, operation and maintenance activities. Runoff is generally computed using rainfall-runoff models. Computer based hydrologic models have become popular for obtaining hydrological forecasts and for managing water systems. Rainfall-runoff library (RRL) is computer software developed by Cooperative Research Centre for Catchment Hydrology (CRCCH), Australia consisting of five different conceptual rainfall-runoff models, and has been in operation in many water resources applications in Australia. Recently, soft artificial intelligence tools such as Artificial Neural Networks (ANNs) have become popular for research purposes but have not been adopted in operational hydrological forecasts. There is a strong need to develop ANN models based on real catchment data and compare them with the conceptual models actually in use in real catchments. In this paper, the results from an investigation on the use of RRL and ANNs are presented. Out of the five conceptual models in the RRL toolkit, SimHyd model has been used. Genetic Algorithm has been used as an optimizer in the RRL to calibrate the SimHyd model. Trial and error procedures were employed to arrive at the best values of various parameters involved in the GA optimizer to develop the SimHyd model. The results obtained from the best configuration of the SimHyd model are presented here. Feed-forward neural network model structure trained by back-propagation training algorithm has been adopted here to develop the ANN models. The daily rainfall and runoff data derived from Bird Creek Basin, Oklahoma, USA have been employed to develop all the models included here. A wide range of error statistics have been used to evaluate the performance of all the models developed in this study. The ANN models developed consistently outperformed the conceptual model developed in this study. The results obtained in this study indicate that the ANNs can be extremely useful tools for modeling the complex rainfall-runoff process in real catchments. The ANNs should be adopted in real catchments for hydrological modeling and forecasting. It is hoped that more research will be carried out to compare the performance of ANN model with the conceptual models actually in use at catchment scales. It is hoped that such efforts may go a long way in making the ANNs more acceptable by the policy makers, water resources decision makers, and traditional hydrologists.

  11. Modeling of reservoir operation in UNH global hydrological model

    NASA Astrophysics Data System (ADS)

    Shiklomanov, Alexander; Prusevich, Alexander; Frolking, Steve; Glidden, Stanley; Lammers, Richard; Wisser, Dominik

    2015-04-01

    Climate is changing and river flow is an integrated characteristic reflecting numerous environmental processes and their changes aggregated over large areas. Anthropogenic impacts on the river flow, however, can significantly exceed the changes associated with climate variability. Besides of irrigation, reservoirs and dams are one of major anthropogenic factor affecting streamflow. They distort hydrological regime of many rivers by trapping of freshwater runoff, modifying timing of river discharge and increasing the evaporation rate. Thus, reservoirs is an integral part of the global hydrological system and their impacts on rivers have to be taken into account for better quantification and understanding of hydrological changes. We developed a new technique, which was incorporated into WBM-TrANS model (Water Balance Model-Transport from Anthropogenic and Natural Systems) to simulate river routing through large reservoirs and natural lakes based on information available from freely accessible databases such as GRanD (the Global Reservoir and Dam database) or NID (National Inventory of Dams for US). Different formulations were applied for unregulated spillway dams and lakes, and for 4 types of regulated reservoirs, which were subdivided based on main purpose including generic (multipurpose), hydropower generation, irrigation and water supply, and flood control. We also incorporated rules for reservoir fill up and draining at the times of construction and decommission based on available data. The model were tested for many reservoirs of different size and types located in various climatic conditions using several gridded meteorological data sets as model input and observed daily and monthly discharge data from GRDC (Global Runoff Data Center), USGS Water Data (US Geological Survey), and UNH archives. The best results with Nash-Sutcliffe model efficiency coefficient in the range of 0.5-0.9 were obtained for temperate zone of Northern Hemisphere where most of large reservoirs designed for hydropower generation, water supply and flood control. Less reliable results were observed for Africa and dry areas of Asia and America. There are several possible causes of large uncertainties in discharge simulations for these areas including: accuracy of observational data, model underestimation of extensive water use and greater uncertainties of used climatic data in these regions due to sparser observational network. In general the applied approach for streamflow routing through reservoirs and large natural lakes has significantly improved simulated discharge estimates.

  12. Identification of the HYPE hydrological model over the Indian subcontinent

    NASA Astrophysics Data System (ADS)

    Pechlivanidis, Ilias; Gustafsson, David; Arheimer, Berit

    2014-05-01

    Large-scale hydrological modelling has the potential to encompass many river basins, cross regional and international boundaries and represent a number of different geophysical and climatic zones. However the performance of this type of model is subject to several sources of uncertainty/error which may be caused by, among others, the imperfectness of driving inputs, i.e. regional and global databases. This uncertainty further leads to wrong model parameterisation and incomplete process understanding. Data assimilation aims to utilize both hydrological process knowledge (as embodied in a hydrologic model) and information that can be gained from observations; hence information from model predictions and observations is synergistically used to improve performance. This study presents a methodology, drawn on experience from modelling with the HYPE model in the Indian subcontinent (covering a modelled area of 4.9 million km2), to enhance identification of highly parameterised large-scale hydrological models. The model was set up using available large-scale datasets on topography, land use, soil, precipitation, temperature, lakes, reservoirs, crop types, irrigation, evaporation, snow and discharge. A stepwise automatic calibration is carried out to avoid, to a certain extent, errors incurring in some model processes and being compensated by introducing errors in other parts of the model. In addition, information from remote sensing data is assimilated in the model to drive identification of parameters that control the spatial distribution of potential evapotranspiration. Results show that despite the strong hydro-climatic gradient over the domain, the model can adequately describe the hydrological process in the Indian subcontinent. Overall, the median Kling-Gupta Efficiency (KGE) increased from 0.08 to 0.64 during the calibration process using 43 stations of monthly discharge series over the period 1971 to 1979. Finally, decomposition of the KGE (i.e. into terms describing agreement in correlation, bias and variability between observed and modelled streamflow series) allowed a thorough understanding of model inadequacies. Keywords Large-scale hydrological modelling, HYPE, model identification, Kling-Gupta Efficiency, remote sensing, India

  13. Hydrologic Modeling of the Iroquois River Watershed Using HSPF and SWAT

    Microsoft Academic Search

    Jaswinder Singh; H. Vernon Knapp; Misganaw Demissie

    2004-01-01

    Watershed scale hydrologic simulation models HSPF (Hydrologic Simulation Program - FORTRAN) and SWAT (Soil and Water Assessment Tool) were used to model the hydrology of the 2150 square mile Iroquois River watershed (IRW) located in the east central Illinois. Both models are part of the BASINS modeling system that facilitates pre- and post-processing of data, as well as data input

  14. ERDC/ELTR-14-2 Hydrology Model Formulation within the

    E-print Network

    US Army Corps of Engineers

    ERDC/ELTR-14-2 Hydrology Model Formulation within the Training Range Environmental Evaluation innovative solutions in civil and military engineering, geospatial sciences, water resources 2014 Hydrology Model Formulation within the Training Range Environmental Evaluation

  15. Flash flood modeling with the MARINE hydrological distributed model

    NASA Astrophysics Data System (ADS)

    Estupina-Borrell, V.; Dartus, D.; Ababou, R.

    2006-11-01

    Flash floods are characterized by their violence and the rapidity of their occurrence. Because these events are rare and unpredictable, but also fast and intense, their anticipation with sufficient lead time for warning and broadcasting is a primary subject of research. Because of the heterogeneities of the rain and of the behavior of the surface, spatially distributed hydrological models can lead to a better understanding of the processes and so on they can contribute to a better forecasting of flash flood. Our main goal here is to develop an operational and robust methodology for flash flood forecasting. This methodology should provide relevant data (information) about flood evolution on short time scales, and should be applicable even in locations where direct observations are sparse (e.g. absence of historical and modern rainfalls and streamflows in small mountainous watersheds). The flash flood forecast is obtained by the physically based, space-time distributed hydrological model "MARINE'' (Model of Anticipation of Runoff and INondations for Extreme events). This model is presented and tested in this paper for a real flash flood event. The model consists in two steps, or two components: the first component is a "basin'' flood module which generates flood runoff in the upstream part of the watershed, and the second component is the "stream network'' module, which propagates the flood in the main river and its subsidiaries. The basin flash flood generation model is a rainfall-runoff model that can integrate remotely sensed data. Surface hydraulics equations are solved with enough simplifying hypotheses to allow real time exploitation. The minimum data required by the model are: (i) the Digital Elevation Model, used to calculate slopes that generate runoff, it can be issued from satellite imagery (SPOT) or from French Geographical Institute (IGN); (ii) the rainfall data from meteorological radar, observed or anticipated by the French Meteorological Service (Météo France); and (iii) the spatially distributed soil and other surface properties viewed from space (land cover map from SPOT or LANDSAT, main rivers, ...). The stream flood propagation model simulates flood propagation in main rivers by solving 1-D Saint Venant equations. The data required for this part of the model are the river morphology, topography and roughness. The MARINE model has already been used previously for real time flash floods forecasting in the frame of the PACTES project on "forecasting and anticipation of floods with spatial techniques'' (funded by the CNES and the French Ministry of Research) concerning the catastrophic 1999 flash flood that occurred in the South of France. The main advantages of MARINE are its ability to run on insufficiently gauged basins (with the help of satellite information) and to run in an operational mode for real-time flood forecasting.

  16. Sharing hydrological knowledge: an international comparison of hydrological models in the Meuse River Basin

    NASA Astrophysics Data System (ADS)

    Bouaziz, Laurène; Sperna Weiland, Frederiek; Drogue, Gilles; Brauer, Claudia; Weerts, Albrecht

    2015-04-01

    International collaboration between institutes and universities working and studying the same transboundary basin is needed for consensus building around possible effects of climate change and climate adaptation measures. Education, experience and expert knowledge of the hydrological community have resulted in the development of a great variety of model concepts, calibration and analysis techniques. Intercomparison could be a first step into consensus modeling or an ensemble based modeling strategy. Besides these practical objectives, such an intercomparison offers the opportunity to explore different ranges of models and learn from each other, hopefully increasing the insight into the hydrological processes that play a role in the transboundary basin. In this experiment, different international research groups applied their rainfall-runoff model in the Ourthe, a Belgium sub-catchment of the Meuse. Data preparation involved the interpolation of hourly precipitation station data collected and owned by the Service Public de Wallonie1 and the freely available E-OBS dataset for daily temperature (Haylock et al., 2008). Daily temperature was disaggregated to hourly values and potential evaporation was derived with the Hargreaves formula. The data was made available to the researchers through an FTP server. The protocol for the modeling involved a split-sample calibration and validation for pre-defined periods. Objective functions for calibration were fixed but the calibration algorithm was a free choice of the research groups. The selection of calibration algorithm was considered model dependent because lumped as well as computationally less efficient distributed models were used. For each model, an ensemble of best performing parameter sets was selected and several performance metrics enabled to assess the models' abilities to simulate discharge. The aim of this experiment is to identify those model components and structures that increase model performance and may best represent the catchment's hydrological behavior. Further steps in the collaboration may include (1) repeating the experiment for other sub-catchments of the Meuse River Basin where different hydrological processes may be relevant and where other models may perform better; and (2) the comparison of hydrological model results obtained by forcing the model with daily local measured precipitation and lower resolution gridded precipitation from the E-OBS (Haylock et at., 2008) dataset to estimate the value of high-resolution data versus lower resolution gridded products. 1 Service Publique de Wallonie, Direction générale opérationnelle de la Mobilité et des Voies hydrauliques, Département des Etudes et de l'Appui à la Gestion, Direction de la Gestion hydrologique intégrée, Boulevard du Nord 8 - 5000 Namur "Haylock, M.R., N. Hofstra, A.M.G. Klein Tank, E.J. Klok, P.D. Jones and M. New. 2008: A European daily high-resolution gridded dataset of surface temperature and precipitation. J. Geophys. Res (Atmospheres), 113, D20119, doi:10.1029/2008JD10201"

  17. Information and complexity measures for hydrologic model evaluation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrological models are commonly evaluated through the residual-based performance measures such as the root-mean square error or efficiency criteria. Such measures, however, do not evaluate the degree of similarity of patterns in simulated and measured time series. The objective of this study was to...

  18. Green roof hydrologic performance and modeling: a review.

    PubMed

    Li, Yanling; Babcock, Roger W

    2014-01-01

    Green roofs reduce runoff from impervious surfaces in urban development. This paper reviews the technical literature on green roof hydrology. Laboratory experiments and field measurements have shown that green roofs can reduce stormwater runoff volume by 30 to 86%, reduce peak flow rate by 22 to 93% and delay the peak flow by 0 to 30 min and thereby decrease pollution, flooding and erosion during precipitation events. However, the effectiveness can vary substantially due to design characteristics making performance predictions difficult. Evaluation of the most recently published study findings indicates that the major factors affecting green roof hydrology are precipitation volume, precipitation dynamics, antecedent conditions, growth medium, plant species, and roof slope. This paper also evaluates the computer models commonly used to simulate hydrologic processes for green roofs, including stormwater management model, soil water atmosphere and plant, SWMS-2D, HYDRUS, and other models that are shown to be effective for predicting precipitation response and economic benefits. The review findings indicate that green roofs are effective for reduction of runoff volume and peak flow, and delay of peak flow, however, no tool or model is available to predict expected performance for any given anticipated system based on design parameters that directly affect green roof hydrology. PMID:24569270

  19. Test plan for hydrologic modeling of protective barriers

    SciTech Connect

    Fayer, M.J.

    1990-03-01

    Pacific Northwest Laboratory prepared this test plan for the Model Applications and Validation Task of the Hanford Protective Barriers Program, which is managed by Westinghouse Hanford Company. The objectives of this plan are to outline the conceptual hydrologic model of protective barriers, discuss the available computer codes, describe the interrelationships between the modeling task and the other tasks of the Protective Barriers Program, present the barrier modeling tests, and estimate the schedule and costs of the hydrologic modeling task for planning purposes by the Protective Barriers Program. The purpose of the tests is to validate models that will be used to confirm the long-term performance of the barrier in minimizing drainage. A second purpose of the tests is to provide information to other parts of the Protective Barriers Program that require such information. 26 refs., 2 figs., 3 tabs.

  20. The Integrated Landscape Hydrology Model (ILHM), a Fully-Distributed Approach to Simulate Regional Watershed Hydrologic Processes

    NASA Astrophysics Data System (ADS)

    Hyndman, D. W.; Kendall, A. D.

    2006-12-01

    Modeling fine-scale regional landscape and subsurface hydrology with fully-distributed process models requires data and computational resources that have only recently become available. For this reason most hydrologic models either do not represent crucial hydrologic processes or are not practical for regional-scale simulations. To overcome these limitations we linked a set of existing codes with novel approaches in the new Integrated Landscape Hydrology Model (ILHM), designed to integrate widely-available GIS and remotely- sensed data using a simple parameterization The ILHM is a loosely-coupled suite of codes that allows fine-scale numerical modeling for some processes while integrating simpler water-balance models at disparate temporal and spatial scales. This approach enables individual process models to be swapped with different modules or with measured data. Currently, the ILHM includes codes that simulate canopy and soil processes, snowpack accumulation and melt, surface ponding and runoff, shallow sub-surface flow, and both unsaturated and saturated groundwater flow. The ILHM also has potential as a tool to simulate fluxes through large ungaged basins and evaluate historical and future hydrologic scenarios. We present an application of the ILHM to a 137 square kilometer catchment within the larger Muskegon River Watershed in northern-lower Michigan. A comparison of model outputs to measured and gaged stream discharges demonstrates that the ILHM is capable of predicting hydrologic fluxes with reasonable accuracy without significant parameter calibration. In addition, the model results suggest interesting and important linkages between land use and groundwater recharge.

  1. JAMS - a software platform for modular hydrological modelling

    NASA Astrophysics Data System (ADS)

    Kralisch, Sven; Fischer, Christian

    2015-04-01

    Current challenges of understanding and assessing the impacts of climate and land use changes on environmental systems demand for an ever-increasing integration of data and process knowledge in corresponding simulation models. Software frameworks that allow for a seamless creation of integrated models based on less complex components (domain models, process simulation routines) have therefore gained increasing attention during the last decade. JAMS is an Open-Source software framework that has been especially designed to cope with the challenges of eco-hydrological modelling. This is reflected by (i) its flexible approach for representing time and space, (ii) a strong separation of process simulation components from the declarative description of more complex models using domain specific XML, (iii) powerful analysis and visualization functions for spatial and temporal input and output data, and (iv) parameter optimization and uncertainty analysis functions commonly used in environmental modelling. Based on JAMS, different hydrological and nutrient-transport simulation models were implemented and successfully applied during the last years. We will present the JAMS core concepts and give an overview of models, simulation components and support tools available for that framework. Sample applications will be used to underline the advantages of component-based model designs and to show how JAMS can be used to address the challenges of integrated hydrological modelling.

  2. eWaterCycle: A global operational hydrological forecasting model

    NASA Astrophysics Data System (ADS)

    van de Giesen, Nick; Bierkens, Marc; Donchyts, Gennadii; Drost, Niels; Hut, Rolf; Sutanudjaja, Edwin

    2015-04-01

    Development of an operational hyper-resolution hydrological global model is a central goal of the eWaterCycle project (www.ewatercycle.org). This operational model includes ensemble forecasts (14 days) to predict water related stress around the globe. Assimilation of near-real time satellite data is part of the intended product that will be launched at EGU 2015. The challenges come from several directions. First, there are challenges that are mainly computer science oriented but have direct practical hydrological implications. For example, we aim to make use as much as possible of existing standards and open-source software. For example, different parts of our system are coupled through the Basic Model Interface (BMI) developed in the framework of the Community Surface Dynamics Modeling System (CSDMS). The PCR-GLOBWB model, built by Utrecht University, is the basic hydrological model that is the engine of the eWaterCycle project. Re-engineering of parts of the software was needed for it to run efficiently in a High Performance Computing (HPC) environment, and to be able to interface using BMI, and run on multiple compute nodes in parallel. The final aim is to have a spatial resolution of 1km x 1km, which is currently 10 x 10km. This high resolution is computationally not too demanding but very memory intensive. The memory bottleneck becomes especially apparent for data assimilation, for which we use OpenDA. OpenDa allows for different data assimilation techniques without the need to build these from scratch. We have developed a BMI adaptor for OpenDA, allowing OpenDA to use any BMI compatible model. To circumvent memory shortages which would result from standard applications of the Ensemble Kalman Filter, we have developed a variant that does not need to keep all ensemble members in working memory. At EGU, we will present this variant and how it fits well in HPC environments. An important step in the eWaterCycle project was the coupling between the hydrological and hydrodynamic models. The hydrological model will run operationally for the whole globe. Once special situations are predicted, such as floods, navigation hindrances, or water shortages, a detailed local hydraulic model will start to predict the exact local consequences. In Vienna, we will show for the first time the operational global eWaterCycle model, including high resolution forecasts, our new data assimilation technique, and coupled hydrological/hydraulic models.

  3. Spatial transferability of landscape-based hydrological models

    NASA Astrophysics Data System (ADS)

    Gao, Hongkai; Hrachowitz, Markus; Fenicia, Fabrizio; Gharari, Shervan; Sriwongsitanon, Nutchanart; Savenije, Hubert

    2015-04-01

    Landscapes, mainly distinguished by land surface topography and vegetation cover, are crucial in defining runoff generation mechanisms, interception capacity and transpiration processes. Landscapes information provides modelers with a way to take into account catchment heterogeneity, while simultaneously keeping model complexity low. A landscape-based hydrological modelling framework (FLEX-Topo), with parallel model structures, was developed and tested in various catchments with diverse climate, topography and land cover conditions. Landscape classification is the basic and most crucial procedure to create a tailor-made model for a certain catchment, as it explicitly relates hydrologic similarity to landscape similarity, which is the base of this type of models. Therefore, the study catchment is classified into different landscapes units that fulfil similar hydrological function, based on classification criteria such as the height above the nearest drainage, slope, aspect and land cover. At present, to suggested model includes four distinguishable landscapes: hillslopes, terraces/plateaus, riparian areas, and glacierized areas. Different parallel model structures are then associated with the different landscape units to describe their different dominant runoff generation mechanisms. These hydrological units are parallel and only connected by groundwater reservoir. The transferability of this landscape-based model can then be compared with the transferability of a lumped model. In this study, FLEX-Topo was developed and tested in three study sites: two cold-arid catchments in China (the upper Heihe River and the Urumqi Glacier No1 catchment), and one tropical catchment in Thailand (the upper Ping River). Stringent model tests indicate that FLEX-Topo, allowing for more process heterogeneity than lumped model formulations, exhibits higher capabilities to be spatially transferred. Furthermore, the simulated water balances, including internal fluxes, hydrograph components, interception and transpiration from different landscapes, fit well with our existing knowledge obtained from experimental hydrologists.

  4. Application of a single hydrological model for two remote watersheds in tropical and cold climates

    Microsoft Academic Search

    Natalia Kotova; Olga Semenova

    2010-01-01

    Application of a single hydrological model for two remote watersheds in tropical and cold climates Natalia Kotova, Olga Semenova The results of runoff simulations for two mountainous watersheds in rain tropical forest and permafrost taiga will be presented. The objective is to demonstrate the possibility of application of a single hydrological model in various climate conditions. The distributed hydrological model

  5. The application of remote sensing to the development and formulation of hydrologic planning models

    NASA Technical Reports Server (NTRS)

    Fowler, T. R.; Castruccio, P. A.; Loats, H. L., Jr.

    1977-01-01

    The development of a remote sensing model and its efficiency in determining parameters of hydrologic models are reviewed. Procedures for extracting hydrologic data from LANDSAT imagery, and the visual analysis of composite imagery are presented. A hydrologic planning model is developed and applied to determine seasonal variations in watershed conditions. The transfer of this technology to a user community and contract arrangements are discussed.

  6. Flexible hydrological modeling - Disaggregation from lumped catchment scale to higher spatial resolutions

    NASA Astrophysics Data System (ADS)

    Tran, Quoc Quan; Willems, Patrick; Pannemans, Bart; Blanckaert, Joris; Pereira, Fernando; Nossent, Jiri; Cauwenberghs, Kris; Vansteenkiste, Thomas

    2015-04-01

    Based on an international literature review on model structures of existing rainfall-runoff and hydrological models, a generalized model structure is proposed. It consists of different types of meteorological components, storage components, splitting components and routing components. They can be spatially organized in a lumped way, or on a grid, spatially interlinked by source-to-sink or grid-to-grid (cell-to-cell) routing. The grid size of the model can be chosen depending on the application. The user can select/change the spatial resolution depending on the needs and/or the evaluation of the accuracy of the model results, or use different spatial resolutions in parallel for different applications. Major research questions addressed during the study are: How can we assure consistent results of the model at any spatial detail? How can we avoid strong or sudden changes in model parameters and corresponding simulation results, when one moves from one level of spatial detail to another? How can we limit the problem of overparameterization/equifinality when we move from the lumped model to the spatially distributed model? The proposed approach is a step-wise one, where first the lumped conceptual model is calibrated using a systematic, data-based approach, followed by a disaggregation step where the lumped parameters are disaggregated based on spatial catchment characteristics (topography, land use, soil characteristics). In this way, disaggregation can be done down to any spatial scale, and consistently among scales. Only few additional calibration parameters are introduced to scale the absolute spatial differences in model parameters, but keeping the relative differences as obtained from the spatial catchment characteristics. After calibration of the spatial model, the accuracies of the lumped and spatial models were compared for peak, low and cumulative runoff total and sub-flows (at downstream and internal gauging stations). For the distributed models, additional validation on spatial results was done for the groundwater head values at observation wells. To ensure that the lumped model can produce results as accurate as the spatially distributed models or close regardless to the number of parameters and implemented physical processes, it was checked whether the structure of the lumped models had to be adjusted. The concept has been implemented in a PCRaster - Python platform and tested for two Belgian case studies (catchments of the rivers Dijle and Grote Nete). So far, use is made of existing model structures (NAM, PDM, VHM and HBV). Acknowledgement: These results were obtained within the scope of research activities for the Flemish Environment Agency (VMM) - division Operational Water Management on "Next Generation hydrological modeling", in cooperation with IMDC consultants, and for Flanders Hydraulics Research (Waterbouwkundig Laboratorium) on "Effect of climate change on the hydrological regime of navigable watercourses in Belgium".

  7. Impacts of Climate change on the watershed of the hydropower reservoir Gigerwaldsee using hydrological modeling

    NASA Astrophysics Data System (ADS)

    Etter, Simon; Seibert, Jan; Vis, Marc; Addor, Nans; Huss, Matthias; Finger, David

    2015-04-01

    Increasing temperatures and changing precipitation patterns will diminish snow cover and force glaciers to shrink in mountain environments. The runoff in Alpine catchments such as the watershed of the Gigerwaldsee, providing water resources for hydro power production in the Swiss Alps, will be affected by those changes. Using an updated version of the conceptual hydrological model HBV-light future hydro-climatic changes in the catchment where simulated. The hydrological model was driven by seven GCM-RCM combinations from the ENSEMBLES project under the emission scenario A1B. The climate projections were bias-corrected using quantile mapping. Besides a baseline scenario (1992-2021), a mid-term future scenario (2036-2065) and a long term scenario (2069-2098) were calculated. For calibration, the model was driven with a gridded dataset from MeteoSwiss and glacier extents from 1990. The calibration was performed using three datasets: i) discharge data, derived from a volume-lake level relationship of the Gigerwaldsee, ii) the fraction of the snow covered area in the catchment, retrieved from MODIS snowcover images and iii) extrapolated glacier mass balances. The parameters were determined using Pareto selection from 10'000 Monte Carlo simulation runs according to their performance over five objective functions. Two objective functions were used to evaluate the discharge simulation and two for snow cover, whereof one rated the simulation over the whole year and one only during summer. A fifth objective function was used for glacier mass balance simulations. An evaluation of different selections of parameter sets showed that relying on discharge, snowcover and glacier mass balance data led to a higher model consistency. The contribution of the climate scenarios, model parameters and glacier scenarios to the total uncertainty of the simulated future discharge was assessed using analysis of variance (ANOVA). The results indicate a decrease in runoff during the high flow season due to shorter snowcover persistence and less precipitation and an increase in runoff in the low flow season due to higher temperatures and more precipitation. The runoff originating from snow melt is projected to decrease by 22% and 30%, respectively. The projected runoff from glaciers will diminish by 85% in the mid-term and disappear completely in the long-term. The results from discharge emerging from snow- and glacier melt are significant. The main cause for the spread in the results was found in the large differences between the climate scenarios. These results are in line with findings of a similar study about the Mattmark reservoir in the Vispa valley.

  8. The coupled routing and excess storage (CREST) distributed hydrological model

    Microsoft Academic Search

    Jiahu Wang; Yang Hong; Li Li; Jonathan J. Gourley; Sadiq I. Khan; Koray K. Yilmaz; Robert F. Adler; Frederick S. Policelli; Shahid Habib; Daniel Irwn; Ashutosh S. Limaye; Tesfaye Korme; Lawrence Okello

    2011-01-01

    The Coupled Routing and Excess STorage model (CREST, jointly developed by the University of Oklahoma and NASA SERVIR) is a distributed hydrological model developed to simulate the spatial and temporal variation of land surface, and subsurface water fluxes and storages by cell-to-cell simulation. CREST's distinguishing characteristics include: (1) distributed rainfall–runoff generation and cell-to-cell routing; (2) coupled runoff generation and routing

  9. Climate Change Impacts to Watershed Hydrology using an Integrated Hydrologic Model (Invited)

    NASA Astrophysics Data System (ADS)

    Huntington, J. L.; Niswonger, R. G.

    2010-12-01

    Many climatologists project that increased green house gases (GHGs) will cause long term changes to the earth's climate superimposed onto historical variability of climate. As a result, climate change poses a difficult problem for water resource managers making longterm forcasts. Modeling hydrologic change associated with climate variability has historically been performed with compartmental models, where surface and groundwater interactions are decoupled. For example, in the few studies that explicitly consider the effects of the unsaturated zone on recharge, the unsaturated zone is represented as a stagnant column of soil through which water flows independently of the underlying water table. Furthermore, previous studies have not considered the coupled interactions of the streamflow components, including snowmelt, runoff, subsurfrace stormflow, and groundwater flow. The interaction of these dynamic coupled processes need to be simulated so they can change with the climate, rather than assuming stagnant conditions based on the present climate. Consequently, to fully assess how climate change might affect water resources, integrated models are likely the best tools. Snow dominated watersheds of the Sierra Nevada are of great importance to water supplies in the western U.S. To analyze how climate change might affect these watersheds, we rely on a integrated surface and groundwater model for three snow dominated watersheds of the eastern Sierra Nevada that are tributary to Lake Tahoe and Truckee Meadows hydrographic areas of California and Nevada. Streamflow was simulated over a 20 year period, and results indicate that 4 month, 6 month, 2 year, and 11 year observed perodicities are well simulated. Model predicted 11 year periodicities are the result of simulating spatial and temporal variations in groundwater recharge, groundwater storage, and groundwater discharge to streams. To assess hydrologic change, we use as direct input, bias corrected and statistically down scaled GCM projections of daily temperature and precipitation from 2010 to 2100 using six GCMs and 2 greenhouse gas emissions scenarios of A2 and B1. To illustrate clear cause and effect, several hydrologic processes are presented together where ensemble means of selected results for each GHG scenario and watershed are grouped to show mean monthly hydrologic change throughout the early, mid, and late 21st century. Model results indicate that significant changes in mountain hydrology of the Sierra Nevada are likely to occur due to projected climate change, including shifts in the timing and magnitude of groundwater recharge and discharge. For example, multiple processes work together to provide springflow and streamflow during driest part of the season. Warming due to climate change reduces the snow pack during the spring snowmelt period and shifts the timing of the peak of groundwater discharge to springs and streams earlier in the season. Consequently, the aridity of these basins will increase during the warmest parts of the year. These results highlight the extreme interdependencies in the predicted changes of streamflow, evapotranspiration, groundwater recharge, and groundwater discharge.

  10. Hydrologic modeling to screen potential environmental management methods for malaria vector control in Niger

    E-print Network

    Gianotti, Rebecca Louise

    This paper describes the first use of Hydrology-Entomology and Malaria Transmission Simulator (HYDREMATS), a physically based distributed hydrology model, to investigate environmental management methods for malaria vector ...

  11. Developing a hydrological model in the absence of field data

    NASA Astrophysics Data System (ADS)

    Sproles, E. A.; Orrego Nelson, C.; Kerr, T.; Lopez Aspe, D.

    2014-12-01

    We present two runoff models that use remotely-sensed snow cover products from the Moderate Resolution Imaging Spectrometer (MODIS) as the first order hydrologic input. These simplistic models are the first step in developing an operational model for the Elqui River watershed located in northern Central Chile (30°S). In this semi-arid region, snow and glacier melt are the dominant hydrologic inputs where annual precipitation is limited to three or four winter events. Unfortunately winter access to the Andean Cordillera where snow accumulates is limited. While a monitoring network to measure snow where it accumulates in the upper elevations is under development, management decisions regarding water resources cannot wait. The two models we present differ in structure. The first applies a Monte Carlo approach to determine relationships between lagged changes in monthly snow cover frequency and monthly discharge. The second is a modified degree-day melt model, utilizing the MODIS snow cover product to determine where and when snow melt occurs. These models are not watershed specific and are applicable in other regions where snow dominates hydrologic inputs, but measurements are minimal.

  12. Hydrological Modelling and Parameter Identification for Green Roof

    NASA Astrophysics Data System (ADS)

    Lo, W.; Tung, C.

    2012-12-01

    Green roofs, a multilayered system covered by plants, can be used to replace traditional concrete roofs as one of various measures to mitigate the increasing stormwater runoff in the urban environment. Moreover, facing the high uncertainty of the climate change, the present engineering method as adaptation may be regarded as improper measurements; reversely, green roofs are unregretful and flexible, and thus are rather important and suitable. The related technology has been developed for several years and the researches evaluating the stormwater reduction performance of green roofs are ongoing prosperously. Many European counties, cities in the U.S., and other local governments incorporate green roof into the stormwater control policy. Therefore, in terms of stormwater management, it is necessary to develop a robust hydrologic model to quantify the efficacy of green roofs over different types of designs and environmental conditions. In this research, a physical based hydrologic model is proposed to simulate water flowing process in the green roof system. In particular, the model adopts the concept of water balance, bringing a relatively simple and intuitive idea. Also, the research compares the two methods in the surface water balance calculation. One is based on Green-Ampt equation, and the other is under the SCS curve number calculation. A green roof experiment is designed to collect weather data and water discharge. Then, the proposed model is verified with these observed data; furthermore, the parameters using in the model are calibrated to find appropriate values in the green roof hydrologic simulation. This research proposes a simple physical based hydrologic model and the measures to determine parameters for the model.

  13. Pursuing the method of multiple working hypotheses for hydrological modeling

    NASA Astrophysics Data System (ADS)

    Clark, Martyn P.; Kavetski, Dmitri; Fenicia, Fabrizio

    2011-09-01

    Ambiguities in the representation of environmental processes have manifested themselves in a plethora of hydrological models, differing in almost every aspect of their conceptualization and implementation. The current overabundance of models is symptomatic of an insufficient scientific understanding of environmental dynamics at the catchment scale, which can be attributed to difficulties in measuring and representing the heterogeneity encountered in natural systems. This commentary advocates using the method of multiple working hypotheses for systematic and stringent testing of model alternatives in hydrology. We discuss how the multiple-hypothesis approach provides the flexibility to formulate alternative representations (hypotheses) describing both individual processes and the overall system. When combined with incisive diagnostics to scrutinize multiple model representations against observed data, this provides hydrologists with a powerful and systematic approach for model development and improvement. Multiple-hypothesis frameworks also support a broader coverage of the model hypothesis space and hence improve the quantification of predictive uncertainty arising from system and component nonidentifiabilities. As part of discussing the advantages and limitations of multiple-hypothesis frameworks, we critically review major contemporary challenges in hydrological hypothesis-testing, including exploiting different types of data to investigate the fidelity of alternative process representations, accounting for model structure ambiguities arising from major uncertainties in environmental data, quantifying regional differences in dominant hydrological processes, and the grander challenge of understanding the self-organization and optimality principles that may functionally explain and describe the heterogeneities evident in most environmental systems. We assess recent progress in these research directions, and how new advances are possible using multiple-hypothesis methodologies.

  14. Complexity of a flexible topography driven conceptual hydrological model

    NASA Astrophysics Data System (ADS)

    Moayeri, MohamadMehdi; Gharari, Shervan; Pande, Saket

    2015-04-01

    Defining a measure of complexity for a hydrological model is required for selection of a model structure among the structures an expert designs. Flex-Topo conceptual modelling approach enables us to design different model structures. We define complexity of a model as a measure in the model output space which can be used for selecting optimal model by minimizing empirical risk of models indicating lowest complex model. We applied this approach on different model structures which we designed a Flex-Topo model for a catchment in Iran. These model structures are based on landscape units including plateau, hillslope and wetland with separate conceptualisation of water balance and also constitutive equations. The complexity based model selection provides us a model structure which is more robust in prediction of future data in comparison to the other structures.

  15. Quantifying and Generalizing Hydrologic Responses to Dam Regulation using a Statistical Modeling Approach

    SciTech Connect

    McManamay, Ryan A [ORNL

    2014-01-01

    Despite the ubiquitous existence of dams within riverscapes, much of our knowledge about dams and their environmental effects remains context-specific. Hydrology, more than any other environmental variable, has been studied in great detail with regard to dam regulation. While much progress has been made in generalizing the hydrologic effects of regulation by large dams, many aspects of hydrology show site-specific fidelity to dam operations, small dams (including diversions), and regional hydrologic regimes. A statistical modeling framework is presented to quantify and generalize hydrologic responses to varying degrees of dam regulation. Specifically, the objectives were to 1) compare the effects of local versus cumulative dam regulation, 2) determine the importance of different regional hydrologic regimes in influencing hydrologic responses to dams, and 3) evaluate how different regulation contexts lead to error in predicting hydrologic responses to dams. Overall, model performance was poor in quantifying the magnitude of hydrologic responses, but performance was sufficient in classifying hydrologic responses as negative or positive. Responses of some hydrologic indices to dam regulation were highly dependent upon hydrologic class membership and the purpose of the dam. The opposing coefficients between local and cumulative-dam predictors suggested that hydrologic responses to cumulative dam regulation are complex, and predicting the hydrology downstream of individual dams, as opposed to multiple dams, may be more easy accomplished using statistical approaches. Results also suggested that particular contexts, including multipurpose dams, high cumulative regulation by multiple dams, diversions, close proximity to dams, and certain hydrologic classes are all sources of increased error when predicting hydrologic responses to dams. Statistical models, such as the ones presented herein, show promise in their ability to model the effects of dam regulation effects at large spatial scales as to generalize the directionality of hydrologic responses.

  16. Viral dynamics of hepatitis B virus (HBV) DNA in HIV-1-HBV co-infected individuals: similar effectiveness of lamivudine, tenofovir or combination therapy

    PubMed Central

    Lewin, SR; Ribeiro, RM; Avihingsanon, A; Bowden, S; Matthews, G; Marks, P; Locarnini, SA; Ruxrungtham, K; Perelson, AS; Dore, GJ

    2009-01-01

    Following treatment of hepatitis B virus (HBV) infection with nucleos(t)ide reverse transcriptase inhibitors (NRTIs) there is a biphasic clearance of HBV, similar to that seen following treatment of HIV-1 and hepatitis C virus. Little is known about the impact of combination NRTIs and HIV-1 co-infection on HBV viral kinetic parameters following the initiation of HBV-active highly active antiretroviral therapy (HAART). HIV-1-HBV co-infected patients (n=21) were enrolled in a viral kinetics sub-study of the Tenofovir in HIV-1-HBV Coinfection study (TICO). TICO was a randomized (1:1:1) trial of tenofovir disoproxil fumarate (TDF, 300mg) vs lamivudine (LMV, 300mg) vs TDF/LMV within an efavirenz based HAART regimen initiated in HIV-1-HBV co-infected antiretroviral naïve individuals in Thailand. HBV DNA was measured frequently over the first 56 days. To fit the viral load data, we used a model of HBV kinetics that allows the estimation of treatment effectiveness, viral clearance and infected cell loss. We observed a biphasic decline in HBV DNA in almost all patients. We did not observe any significant differences in HBV viral dynamic parameters between the three treatments groups. Overall, median (IQR) HBV treatment effectiveness was 98% (95%–99%), median HBV virion half-life was 1.2 days (0.5–1.4 days), and median infected cell half-life was 7.9 days (6.3–11.0 days). When we compared HBeAg-positive and HBeAg-negative individuals, we found a significantly longer infected cell half-life in HBeAg-positive individuals (6.2 vs. 9.0 days, p=0.02). Conclusion: HBV viral dynamic parameters are similar following anti-HBV NRTI monotherapy and dual combination therapy in the setting of HIV-1-HBV coinfection. HIV-1 co-infection has minimal effect on HBV viral dynamics, even in the setting of advanced HIV-1-related immunosuppression. PMID:19115219

  17. A Geospatial Fabric (GF) for National Hydrological Modeling

    NASA Astrophysics Data System (ADS)

    Viger, R.; Bock, A.

    2014-12-01

    The US Geological Survey (USGS) Geospatial Fabric (GF) supports the USGS National Hydrologic Model (NHM) by defining a minimally sufficient, nationally consistent set of geographic information needed to simulate streamflow at almost 60,000 points of interest (POIs). POIs primarily are defined based on: (a) a high quality set of USGS stream gages (Gages-II), (b) National Weather Service forecast nodes, (c) the USGS National Water Quality Assessment's modeling network, (d) at inlets and outlets of selected water bodies, and (e) at confluences. Each POI is associated with a stream segment which typically has two adjacent land surface areas, referred to as hydrologic response units (HRUs). Parameter tables, largely based on the National Land Cover Databases, the Soil Survey Geographic Database (SSURGO), and the geometry of the spatial data, have been derived for these features. Configurations of GF features and attribute tables are defined and made available through the USGS ScienceBase (https://www.sciencebase.gov/catalog/item/537b7327e4b0929ba496f66f). Data are organized into 20 ESRI file geodatabases, each covering a different region of the United States (https://www.sciencebase.gov/catalog/item/535edb4ae4b08e65d60fc837). Future releases will include additional realizations of NHM parameter tables. These will serve to assess the impact of alternate data sources and processing methodologies on simulated streamflows. Tools for dynamically subsetting geodatabases and model inputs based on custom watersheds are currently being prototyped. The GF is a versatile framework for data integration because it maintains feature-level indexing back to NHDPlus and the National Hydrography Dataset, which is used in many water resource studies. In addition, the GF will help to ensure a minimum initial quality of parameter information, reduce the time of developing hydrological modeling applications in the United States, and generally improve the accuracy and scientific impact of USGS hydrological modeling.

  18. Evaluating three evapotranspiration methods in the SLURP macroscale hydrological model

    NASA Astrophysics Data System (ADS)

    Barr, Alan G.; Kite, G. W.; Granger, R.; Smith, C.

    1997-10-01

    Hydrological models simulate the land phase component of the global water cycle and provide a mechanism for evaluating the effects of climatic variation and change on water resources. Evapotranspiration (ET) is a critical process within such models. This study evaluates three different methods for estimating ET in the simple lumped reservoir parametric model (SLURP), over a five-year period in the Kootenay Basin of eastern British Columbia. The three ET methods were the Morton implementation of the Bouchet complementary relationship, the Granger modification of Penman's method and the Spittlehouse energy-limited versus soil moisture-limited method. We evaluated the three ET methods indirectly, based on the ability of the SLURP hydrological model to simulate daily stream flow over several annual cycles. Although the ET methods affected simulated stream flow differently, the Spittlehouse method had more physical significance and gave better agreement between simulated and recorded stream flows. The results showed that using an ET method that included a soil moisture limitation to ET produced a worthwhile improvement in hydrological performance.

  19. Inverting MODIS Snow Covered Area in a Hydrology Model

    NASA Astrophysics Data System (ADS)

    Slater, A. G.; Clark, M. P.

    2009-12-01

    Direct application of remote sensing products into hydrologic models has been an ongoing challenge for the past 30 years. Microwave signals which have the potential to inform about snow mass, are at low spatial resolution and easily confused by many mixed signals. Snow covered area is much more readily available at the scales relevant to hydrologic models than other snow products derived from remote sensing. The MODIS MOD10A1/MYDA1 products give snow cover as a binary value (present or not) over an area or approximately 500m resolution. This data will contain some error due to the assumption that any pixel with less than 50% snow cover is flagged as bare. In this work we look at snow regimes within a hydrologic model that can reproduce the proportional area of snow cover over a given basin. The model we use is TopNet which includes a scale invariant fractional snow cover parameterization. This parameterization accounts for the hysteresis associated with snow covered area during accumulation and ablation processes. We use two basins (and their subsequent sub-basins) in the Sierra Nevada Mountains of California and Nevada; namely the North Fork of the American River and the East Fork of the Carson. The scale dependence of the ability to reproduce snow fractional cover will be assessed from first order through to fifth order basins and we seek to determine at what scale and under what snow regime can meaningful information be garnered about snow mass.

  20. The hydrology of malaria : field observations and mechanistic modeling of the malaria transmission response to environmental climatic variability

    E-print Network

    Bomblies, Arne

    2009-01-01

    A coupled HYDrology, Entomology and MAlaria Transmission Simulator (HYDREMATS) has been developed. The model simulates the hydrological and climatological determinants of malaria transmission mechanistically and at high ...

  1. A Coupled Surface/Subsurface Model for Hydrological Drought Investigations

    NASA Astrophysics Data System (ADS)

    Musuuza, J. L.; Kumar, R.; Samaniego, L. E.; Fischer, T.; Kolditz, O.; Attinger, S.

    2013-12-01

    Hydrological droughts occur when storage in the ground and surface-water bodies falls below statistical average. Due to the inclusion of regional groundwater, hydrological droughts evolve relatively slowly. The atmospheric and surface components of the hydrological cycle have been widely studied, are well understood, and their prognoses are fairly accurate. In large-scale land surface models on the other hand, subsurface (groundwater) flow processes are usually assumed unidirectional and limited to the vertically-downward percolation and the horizontal runoffs. The vertical feedback from groundwater to the unsaturated zone as well as the groundwater recharge from surface waters are usually misrepresented, resulting in poor model performance during low-flow periods. The feedback is important during meteorological droughts because it replenishes soil moisture from ground- and surface water, thereby delaying the onset of agricultural droughts. If sustained for long periods however, the depletion can significantly reduce surface and subsurface storage and lead to severe hydrological droughts. We hypothesise that an explicit incorporation of the groundwater component into an existing land surface model would lead to better representation of low flows, which is critical for drought analyses. It would also improve the model performance during low-flow periods. For this purpose, we coupled the process-based mHM surface model (Samaniego et al. 2010) with MODFLOW (Harbaugh 2005) to analyse droughts in the Unstrut catchment, one of the tributaries of the Elbe. The catchment is located in one of the most drought-prone areas of Germany. We present results for stand-alone and coupled mHM simulations for the period 1970-2000. References Arlen W. Harbaugh. MODFLOW-2005, The U.S. Geological Survey Modular Ground-water Model-the Ground-water Flow Process, chapter Modelling techniques, sec. A. Ground water, pages 1:1-9:62. USGS, 2005. Luis Samaniego, Rohini Kumar, and Sabine Attinger. Multiscale parameter regionalization of a grid-based hydrologic model at the mesoscale. Water Resour. Res., 46(W05523), 2010. doi: 10.1029/2008WR007327.

  2. Digital elevation model grid size, landscape representation, and hydrologic simulations

    Microsoft Academic Search

    Weihua Zhang; David R. Montgomery

    1994-01-01

    High-resolution digital elevation data from two small catchments in the western United States are used to examine the effect of digital elevation model (DEM) grid size on the portrayed of the land surface and hydrologic simulations. Elevation data were gridded at 2-, 4-, 10-, 30-, and 90-m scales to generate a series of simulated landscapes. Frequency distributions of slope (tanB),

  3. Improvement of Global Hydrological Models Using GRACE Data

    NASA Astrophysics Data System (ADS)

    Güntner, Andreas

    2008-10-01

    After about 6 years of GRACE (Gravity Recovery and Climate Experiment) satellite mission operation, an unprecedented global data set on the spatio-temporal variations of the Earth’s water storage is available. The data allow for a better understanding of the water cycle at the global scale and for large river basins. This review summarizes the experiences that have been made when comparing GRACE data with simulation results of global hydrological models and it points out the prerequisites and perspectives for model improvements by combination with GRACE data. When evaluated qualitatively at the global scale, water storage variations on the continents from GRACE agreed reasonably well with model predictions in terms of their general seasonal dynamics and continental-scale spatial patterns. Differences in amplitudes and phases of water storage dynamics revealed in more detailed analyses were mainly attributed to deficiencies in the meteorological model forcing data, to missing water storage compartments in the model, but also to limitations and errors of the GRACE data. Studies that transformed previously identified model deficiencies into adequate modifications of the model structure or parameters are still rare. Prerequisites for a comprehensive improvement of large-scale hydrological models are in particular the consistency of GRACE observation and model variables in terms of filtering, reliable error estimates, and a full assessment of the water balance. Using improvements in GRACE processing techniques, complementary observation data, multi-model evaluations and advanced methods of multi-objective calibration and data assimilation, considerable progress in large-scale hydrological modelling by integration of GRACE data can be expected.

  4. A rangeland hydrology and erosion model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil loss rates on rangelands are considered one of the few quantitative indicators for assessing rangeland health and conservation practice effectiveness. An erosion model to predict soil loss specific for rangeland applications is needed because existing erosion models were developed from cropland...

  5. RECURSIVE PARAMETER ESTIMATION OF HYDROLOGIC MODELS

    EPA Science Inventory

    Proposed is a nonlinear filtering approach to recursive parameter estimation of conceptual watershed response models in state-space form. he conceptual model state is augmented by the vector of free parameters which are to be estimated from input-output data, and the extended Kal...

  6. Calibration of a distributed hydrological model based on satellite evapotranspiration

    NASA Astrophysics Data System (ADS)

    Immerzeel, W. W.; Droogers, P.

    2008-02-01

    SummaryCalibrating spatially distributed hydrological models is complex due to the lack of reliable data, uncertainty in representing the physical features of a river catchment, and the implementation of hydrological processes in a simulation model. In this paper, an innovative approach is presented which incorporates remote sensing derived evapotranspiration in the calibration of the Soil and Water Assessment Tool (SWAT) in a catchment of the Krishna basin in southern India. The Gauss-Marquardt-Levenberg algorithm is implemented to optimise different combination of land use, soil, groundwater, and meteorological model parameters. In the best performing optimisation, the r2 between monthly sub-basin simulated and measured actual evapotranspiration (ETact) was increased from 0.40 to 0.81. ETact was more sensitive to the groundwater and meteorological parameters than the soil and land use parameters. Traditional calibration on a limited number of discharge stations lumps all hydrological processes together and chances on the equifinality problem are larger. In this study we have shown this problem can be constrained by using spatially distributed observations with a monthly temporal resolution. At a spatial resolution below the sub-basin level further study is required to fine-tune the calibration procedure.

  7. HBV Genotypic Variability in Cuba

    PubMed Central

    Loureiro, Carmen L.; Aguilar, Julio C.; Aguiar, Jorge; Muzio, Verena; Pentón, Eduardo; Garcia, Daymir; Guillen, Gerardo; Pujol, Flor H.

    2015-01-01

    The genetic diversity of HBV in human population is often a reflection of its genetic admixture. The aim of this study was to explore the genotypic diversity of HBV in Cuba. The S genomic region of Cuban HBV isolates was sequenced and for selected isolates the complete genome or precore-core sequence was analyzed. The most frequent genotype was A (167/250, 67%), mainly A2 (149, 60%) but also A1 and one A4. A total of 77 isolates were classified as genotype D (31%), with co-circulation of several subgenotypes (56 D4, 2 D1, 5 D2, 7 D3/6 and 7 D7). Three isolates belonged to genotype E, two to H and one to B3. Complete genome sequence analysis of selected isolates confirmed the phylogenetic analysis performed with the S region. Mutations or polymorphisms in precore region were more common among genotype D compared to genotype A isolates. The HBV genotypic distribution in this Caribbean island correlates with the Y lineage genetic background of the population, where a European and African origin prevails. HBV genotypes E, B3 and H isolates might represent more recent introductions. PMID:25742179

  8. Water Quality Modeling Hydraulics and Hydrology Group

    E-print Network

    ,C,P,Si) · Phyoplankton/Zooplankton, Blue-green algae · And more #12;WQ Model Example 1: Oxygen · 1-D Predictive Water Vehicle · Fu · Fully autonomous vehicle measures: ­ Oxygen ­ Blue-Green Algae ­ Chlorophyll

  9. A one-parameter Budyko model for water balance captures emergent behavior in darwinian hydrologic models

    NASA Astrophysics Data System (ADS)

    Wang, Dingbao; Tang, Yin

    2014-07-01

    Hydrologic models can be categorized as being either Newtonian or Darwinian in nature. The Newtonian approach requires a thorough understanding of the individual physical processes acting in a watershed in order to build a detailed hydrologic model based on the conservation equations. The Darwinian approach seeks to explain the behavior of a hydrologic system as a whole by identifying simple and robust temporal or spatial patterns that capture the relevant processes. Darwinian-based hydrologic models include the Soil Conservation Service (SCS) curve number model, the "abcd" model, and the Budyko-type models. However, these models were developed based on widely differing principles and assumptions and applied to distinct time scales. Here, we derive a one-parameter Budyko-type model for mean annual water balance which is based on a generalization of the proportionality hypothesis of the SCS model and therefore is independent of temporal scale. Furthermore, we show that the new model is equivalent to the key equation of the "abcd" model. Theoretical lower and upper bounds of the new model are identified and validated based on previous observations. Thus, we illustrate a temporal pattern of water balance amongst Darwinian hydrologic models, which allows for synthesis with the Newtonian approach and offers opportunities for progress in hydrologic modeling.

  10. The contribution of the digital elevation models and geographic information systems in a watershed hydrologic research

    Microsoft Academic Search

    Abdelkader Mendas

    2010-01-01

    The hydrological and physical characteristic description of a watershed constitutes an essential task for hydrologic research.\\u000a Usually, this one requires a hydrologic model of which the running needs a great number of data and information. The main\\u000a purpose of this study was to use Shuttle Radar Topography Mission (SRTM) data, free of charge, for hydrologic studies in Algeria.\\u000a This work

  11. Assessing climate change impact by integrated hydrological modelling

    NASA Astrophysics Data System (ADS)

    Lajer Hojberg, Anker; Jørgen Henriksen, Hans; Olsen, Martin; der Keur Peter, van; Seaby, Lauren Paige; Troldborg, Lars; Sonnenborg, Torben; Refsgaard, Jens Christian

    2013-04-01

    Future climate may have a profound effect on the freshwater cycle, which must be taken into consideration by water management for future planning. Developments in the future climate are nevertheless uncertain, thus adding to the challenge of managing an uncertain system. To support the water managers at various levels in Denmark, the national water resources model (DK-model) (Højberg et al., 2012; Stisen et al., 2012) was used to propagate future climate to hydrological response under considerations of the main sources of uncertainty. The DK-model is a physically based and fully distributed model constructed on the basis of the MIKE SHE/MIKE11 model system describing groundwater and surface water systems and the interaction between the domains. The model has been constructed for the entire 43.000 km2 land area of Denmark only excluding minor islands. Future climate from General Circulation Models (GCM) was downscaled by Regional Climate Models (RCM) by a distribution-based scaling method (Seaby et al., 2012). The same dataset was used to train all combinations of GCM-RCMs and they were found to represent the mean and variance at the seasonal basis equally well. Changes in hydrological response were computed by comparing the short term development from the period 1990 - 2010 to 2021 - 2050, which is the time span relevant for water management. To account for uncertainty in future climate predictions, hydrological response from the DK-model using nine combinations of GCMs and RCMs was analysed for two catchments representing the various hydrogeological conditions in Denmark. Three GCM-RCM combinations displaying high, mean and low future impacts were selected as representative climate models for which climate impact studies were carried out for the entire country. Parameter uncertainty was addressed by sensitivity analysis and was generally found to be of less importance compared to the uncertainty spanned by the GCM-RCM combinations. Analysis of the simulations showed some unexpected results, where climate models predicting the largest increase in net precipitation did not result in the largest increase in groundwater heads. This was found to be the result of different initial conditions (1990 - 2010) for the various climate models. In some areas a combination of a high initial groundwater head and an increase in precipitation towards 2021 - 2050 resulted in a groundwater head raise that reached the drainage or the surface water system. This will increase the exchange from the groundwater to the surface water system, but reduce the raise in groundwater heads. An alternative climate model, with a lower initial head can thus predict a higher increase in the groundwater head, although the increase in precipitation is lower. This illustrates an extra dimension in the uncertainty assessment, namely the climate models capability of simulating the current climatic conditions in a way that can reproduce the observed hydrological response. Højberg, AL, Troldborg, L, Stisen, S, et al. (2012) Stakeholder driven update and improvement of a national water resources model - http://www.sciencedirect.com/science/article/pii/S1364815212002423 Seaby, LP, Refsgaard, JC, Sonnenborg, TO, et al. (2012) Assessment of robustness and significance of climate change signals for an ensemble of distribution-based scaled climate projections (submitted) Journal of Hydrology Stisen, S, Højberg, AL, Troldborg, L et al., (2012): On the importance of appropriate rain-gauge catch correction for hydrological modelling at mid to high latitudes - http://www.hydrol-earth-syst-sci.net/16/4157/2012/

  12. Intercomparison of hydrologic processes in global climate models

    NASA Technical Reports Server (NTRS)

    Lau, W. K.-M.; Sud, Y. C.; Kim, J.-H.

    1995-01-01

    In this report, we address the intercomparison of precipitation (P), evaporation (E), and surface hydrologic forcing (P-E) for 23 Atmospheric Model Intercomparison Project (AMIP) general circulation models (GCM's) including relevant observations, over a variety of spatial and temporal scales. The intercomparison includes global and hemispheric means, latitudinal profiles, selected area means for the tropics and extratropics, ocean and land, respectively. In addition, we have computed anomaly pattern correlations among models and observations for different seasons, harmonic analysis for annual and semiannual cycles, and rain-rate frequency distribution. We also compare the joint influence of temperature and precipitation on local climate using the Koeppen climate classification scheme.

  13. Integrated hydrological SVAT model for climate change studies in Denmark

    NASA Astrophysics Data System (ADS)

    Mollerup, M.; Refsgaard, J.; Sonnenborg, T. O.

    2010-12-01

    In a major Danish funded research project (www.hyacints.dk) a coupling is being established between the HIRHAM regional climate model code from Danish Meteorological Institute and the MIKE SHE distributed hydrological model code from DHI. The linkage between those two codes is a soil vegetation atmosphere transfer scheme, which is a module of MIKE SHE. The coupled model will be established for the entire country of Denmark (43,000 km2 land area) where a MIKE SHE based hydrological model already exists (Henriksen et al., 2003, 2008). The present paper presents the MIKE SHE SVAT module and the methodology used for parameterising and calibrating the MIKE SHE SVAT module for use throughout the country. As SVAT models previously typically have been tested for research field sites with comprehensive data on energy fluxes, soil and vegetation data, the major challenge lies in parameterisation of the model when only ordinary data exist. For this purpose annual variations of vegetation characteristics (Leaf Area Index (LAI), Crop height, Root depth and the surface albedo) for different combinations of soil profiles and vegetation types have been simulated by use of the soil plant atmosphere model Daisy (Hansen et al., 1990; Abrahamsen and Hansen, 2000) has been applied. The MIKE SHE SVAT using Daisy generated surface/soil properties model has been calibrated against existing data on groundwater heads and river discharges. Simulation results in form of evapotranspiration and percolation are compared to the existing MIKE SHE model and to observations. To analyse the use of the SVAT model in climate change impact assessments data from the ENSEMBLES project (http://ensembles-eu.metoffice.com/) have been analysed to assess the impacts on reference evapotranspiration (calculated by the Makkink and the Penmann-Monteith equations) as well as on the individual elements in the Penmann-Monteith equation (radiation, wind speed, humidity and temperature). The differences on the hydrological impacts of characterising climate change in terms of changes in the reference evapotranspiration or in the individual climate variables have been analysed. References Abrahamsen, P., and Hansen, S. (2000) Daisy: An Open Soil-Crop-Atmosphere System Model. Environ. Model. Software 15, 313-330. Hansen, S., Jensen, H. E., Nielsen, N. E., and Svendsen, H. (1990). Daisy - soil plant atmostphere system model. Technical Report A10, Miljostyrelsen. Henriksen, H. J., Troldborg, L., Nyegaard, P., Sonnenborg, T. O., Refsgaard, J. C. and Madsen, B. (2003) Methodology for construction, calibration and validation of a national hydrological model for Denmark. Journal of Hydrology 280(1-4), 52-71. Henriksen, H. J., Troldborg, L., Hojberg, A. L. and Refsgaard, J. C. (2008) Assessment of exploitable groundwater resources of Denmark by use of ensemble resource indicators and a numerical groundwater-surface water model. Journal of Hydrology 348(1-2), 224-240.

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

    USGS Publications Warehouse

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

    2013-01-01

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

  15. Self-Organizing Basal Hydrology for Ice Sheet Flowline Models

    NASA Astrophysics Data System (ADS)

    Rutt, I. C.; Benn, D.; Cook, S.; Hulton, N. R.

    2013-12-01

    Subglacial water pressure is a fundamental control on basal drag and glacier sliding rates. However, it has seldom been included as a variable in glacier flow models, mainly due to the great difficulty in calculating water pressure in a realistic yet tractable way. Here we present preliminary results of a simple basal hydrological model designed for coupling to ice sheet flow models. A key feature of the model is that hydraulic conductivity k evolves in response to water discharge Q (which melts ice and increases the capacity of the system) and effective pressure pi - pw (reducing system capacity through ice creep). The timescales of these processes relative to temporal variations in surface water inputs produces contrasting pressure-discharge relationships as an emergent property of the model. Specifically, pw varies directly with Q over diurnal timescales, whereas pw is inversely proportional to Q on seasonal timescales. In combination with suitable friction laws, the hydrology model provides an adaptive basal boundary condition for flowline models. Despite its simplicity, the model allows a rich variety of behaviour to be simulated, including spring 'speed-up' events and summer 'slowdowns'.

  16. The value of regionalised information for hydrological modelling

    NASA Astrophysics Data System (ADS)

    Almeida, S.; Bulygina, N.; McIntyre, N.; Wagener, T.; Buytaert, W.

    2013-12-01

    A recurrent problem in hydrology is the absence of runoff data to calibrate conceptual models. This has implications for the reliable application of such models for prediction of streamflow and water resource management. Whilst a large and increasing number of regions are insufficiently gauged, there are also many highly monitored catchments. Transferring the knowledge gained in data-rich areas to ungauged catchments offers possibilities to overcome the absence of runoff observations in data-scarce regions. Here, we transfer knowledge in the form of response signatures, which reflect the hydrological response characteristics of a particular catchment (e.g. runoff ratio and base flow index). A large data set from the Model Parameter Estimation Experiment (MOPEX) is used to regionalise five different response signatures. Observed response signatures are regressed against physical and climatic characteristics of the catchments. Signatures (with uncertainty) for an ungauged location with known physical and climatic characteristics are then estimated utilising the derived relationships. A Bayesian procedure is subsequently used to condition a hydrological model for the target ungauged catchment on the estimated response signatures with formal uncertainty estimation. Particular challenges related to the Bayesian approach include the specification of the prior distribution and the likelihood functions. In this research we introduce and test a method that considers all five regionalised response signatures, where sources of information are not necessarily independent. By explicitly taking account of the inter-signature error covariance structure, regional information is neither neglected nor double-counted. To avoid masking effects of the model structural error, the value of quantity and quality of regionalised information is assessed employing a ';perfect model' approach. Bayes factor is used to evaluate hydrological predictions, as the commonly used performance measures, such as QQ plots or Nash-Sutcliffe, are shown to be unsuitable. Our results demonstrate that the explicit representation of the uncertainty introduced by the regionalisation procedure (including the inter-dependencies between the regionalised signatures) contributes to an improved specification of the optimal model parameter set. Further, it is shown that higher quality (more precise) information leads to a stronger parameter identification. Lastly, the choice of signature is shown to have a strong impact on the estimation of model parameters. Where resources are finite we therefore suggest that modelling should focus initially on those signatures that give the greatest marginal gains for streamflow estimation.

  17. Eegional scale hydrology: I. Formulation of the VIC2L model coupled to a routing model

    Microsoft Academic Search

    D. LOHMANN; E. RASCHKE; B. NIJSSEN; D. P. LETTENMAIER

    A grid network version of the two-layer Variable Infiltration Capacity (VIC-2L) macroscale hydrological model is described. The VIC-2L model is a hydrologically-based SVAT (Soil Vegetation Atmospheric Transfer) scheme designed to represent the land surface in numerical weather prediction and climate models. It is coupled to a linear routing scheme which is optimized with measured precipitation and streamflow data and is

  18. Hydrologic consistency analysed through modeling at multiple time steps: does hydrological model performance benefit from finer time step information?

    NASA Astrophysics Data System (ADS)

    Ficchi, Andrea; Perrin, Charles; Andréassian, Vazken

    2015-04-01

    We investigate the operational utility of fine time step hydro-climatic information using a large catchment data set. The originality of this data set lies in the availability of precipitation data from the 6-minute rain gauges of Météo-France, and in the size of the catchment set (217 French catchments in total). The rainfall-runoff model used (GR4) has been adapted to hourly and sub-hourly time steps (up to 6-minute) from the daily time step version (Perrin et al., 2003). The model is applied at different time steps ranging from 6-minute to 1 day (6-, 12-, 30-minute, 1-, 3-, 6-, 12-hour and 1 day) and the evolution of model performance for each catchment is evaluated at the daily time step by aggregation of model outputs. Three classes of behavior are found according to the trend of model performance as the time step becomes finer: (i) catchments presenting an improvement of model performance; (ii) catchments with a model performance insensitive to the time step; (iii) catchments for which the performance even deteriorates as the time step becomes finer. The reasons behind these different trends are investigated from a hydrological point of view, by relating the model sensitivity to data at finer time step to catchment descriptors. References: Perrin, C., C. Michel and V. Andréassian (2003), "Improvement of a parsimonious model for streamflow simulation", Journal of Hydrology, 279(1-4): 275-289.

  19. Parameter Sensitivity analysis for hydrological model improvement in diverse catchments

    NASA Astrophysics Data System (ADS)

    Singh, Shailesh Kumar; Yang, Jing; McMillan, Hilary

    2014-05-01

    We investigate the sensitivity of the semi-distributed TopNet hydrological model, in order to understand the important hydrologic processes and influential model parameters to be accurately calibrated. Using different objective functions to evaluate the model performance, sensitivity analysis was done for TopNet applications in seven catchments located in South and North Island of New Zealand, with diverse watershed characteristics (i.e., topographic properties, response behaviours and geological features). The sensitivity approach combining the global sensitivity analysis methodology, Morris method and State Dependent Parameter (SDP) method was used in this study. Generally, the most sensitive parameters are precipitation multiplier( to correct water balance), TOPMODEL f parameter and soil water capacity which contributes to over 50% model uncertainty, while other parameters (e.g., snowmelt and routing parameters) are watershed and objective function dependent. It has being found that shape of the catchments and objective function have a strong influence on the sensitivity of the parameters. A relationship between the catchment feature and the sensitivity of the parameters was established. This will help in selection of sensitive parameters for catchments of interest. Which will help in proper calibration of the model parameters. That in turn will help in improving the model structure and reducing the uncertainty in the prediction due to parameterisation.

  20. Spatial organisation in hydrological model structure for New Zealand catchments

    NASA Astrophysics Data System (ADS)

    McMillan, Hilary; Woods, Ross; Clark, Martyn

    2013-04-01

    Hydrologists increasingly agree that a single hydrological model structure is unlikely to be suitable for all catchments: instead, models should be selected according to characteristics of the catchment. Our challenge is to determine how to select the most appropriate model structure. This complex question requires that we use observed data to infer dominant runoff generation processes, and translate this process knowledge into model structure choices. We can then ask questions such as: over what scales do recommended model structures change? How much data is needed to select model structure? How can we generalise model structure choices to catchments where data is scarce? In this presentation we address these questions, using the New Zealand landscape as our 'virtual laboratory'. New Zealand is an excellent location to test hypotheses relating to model structure, due to its rich diversity of hydrological landscapes. Landscape types range from temperate rainforest with steep, bedrock gorges, through rolling pasture, to alluvial plains with braided rivers. Our method is to apply diagnostic signatures, which use a range of hydrological data types, to target specific aspects of model structure choice. We bring together results from national hydrometric networks, and in-depth studies in experimental catchments, to explore organisation, similarity and diversity in recommended model structures across the New Zealand landscape. To identify model structures which are consistent with measured data, we use a range of diagnostic signatures tailored to the data types available. At the national scale, networks of rain and flow gauges are used to investigate runoff ratio, recession characteristics and threshold responses to precipitation and soil moisture. At the experimental Mahurangi catchments, dense networks of 13 rain, 27 flow and 36 soil moisture gauges within a 50 km2 area enable us to evaluate small-scale patterns and diversities of model structure. In contrast, the experimental Waipara catchment in the Eastern foothills of the NZ alps provides networks of 20 soil moisture sensors and 10 shallow groundwater wells within a 1 km2 catchment, as well as deep groundwater wells and 5 nested flow gauges. This data enables us to test for additional aspects of model design related to groundwater response. We relate the local responses and diagnostic signatures to the wider, national-scale patterns. We consider whether local and national model recommendations are compatible, and how model structure patterns and diversity change with scale. Finally, we consider how uncertainty in measured data sources in NZ has the potential to affect diagnostics and hypothesis testing for model structure.

  1. Geographic distribution of hepatitis B virus (HBV) genotype in patients with chronic HBV infection in Japan

    Microsoft Academic Search

    Etsuro Orito; Takafumi Ichida; Hiroshi Sakugawa; Michio Sata; Norio Horiike; Keisuke Hino; Kiwamu Okita; Takeshi Okanoue; Shiro Iino; Eiji Tanaka; Kazuyuki Suzuki; Hisayoshi Watanabe; Shuhei Hige; Masashi Mizokami

    2001-01-01

    The geographic distribution of hepatitis B virus (HBV) genotypes in Japan and its clinical relevance are poorly understood. We studied 731 Japanese patients with chronic HBV infection. HBV genotype was determined by the restriction fragment length polymorphism (RFLP) method after polymerase chain reaction (PCR). Of the 720 patients with positive PCR, 12 (1.7%) were HBV genotype A, 88 (12.2%) were

  2. Global sensitivity analysis in hydrological modeling: Review of concepts, methods, theoretical framework, and applications

    NASA Astrophysics Data System (ADS)

    Song, Xiaomeng; Zhang, Jianyun; Zhan, Chesheng; Xuan, Yunqing; Ye, Ming; Xu, Chonggang

    2015-04-01

    Sensitivity analysis (SA) aims to identify the key parameters that affect model performance and it plays important roles in model parameterization, calibration, optimization, and uncertainty quantification. However, the increasing complexity of hydrological models means that a large number of parameters need to be estimated. To better understand how these complex models work, efficient SA methods should be applied before the application of hydrological modeling. This study provides a comprehensive review of global SA methods in the field of hydrological modeling. The common definitions of SA and the typical categories of SA methods are described. A wide variety of global SA methods have been introduced to provide a more efficient evaluation framework for hydrological modeling. We review, analyze, and categorize research into global SA methods and their applications, with an emphasis on the research accomplished in the hydrological modeling field. The advantages and disadvantages are also discussed and summarized. An application framework and the typical practical steps involved in SA for hydrological modeling are outlined. Further discussions cover several important and often overlooked topics, including the relationship between parameter identification, uncertainty analysis, and optimization in hydrological modeling, how to deal with correlated parameters, and time-varying SA. Finally, some conclusions and guidance recommendations on SA in hydrological modeling are provided, as well as a list of important future research directions that may facilitate more robust analyses when assessing hydrological modeling performance.

  3. Remote sensing inputs to landscape models which predict future spatial land use patterns for hydrologic models

    NASA Technical Reports Server (NTRS)

    Miller, L. D.; Tom, C.; Nualchawee, K.

    1977-01-01

    A tropical forest area of Northern Thailand provided a test case of the application of the approach in more natural surroundings. Remote sensing imagery subjected to proper computer analysis has been shown to be a very useful means of collecting spatial data for the science of hydrology. Remote sensing products provide direct input to hydrologic models and practical data bases for planning large and small-scale hydrologic developments. Combining the available remote sensing imagery together with available map information in the landscape model provides a basis for substantial improvements in these applications.

  4. Input Variable Selection for Hydrologic Modeling Using Anns

    NASA Astrophysics Data System (ADS)

    Ganti, R.; Jain, A.

    2011-12-01

    The use of artificial neural network (ANN) models in water resources applications has grown considerably over the last couple of decades. In learning problems, where a connectionist network is trained with a finite sized training set, better generalization performance is often obtained when unneeded weights in the network are eliminated. One source of unneeded weights comes from the inclusion of input variables that provide little information about the output variables. Hence, in the ANN modeling methodology, one of the approaches that has received little attention, is the selection of appropriate model inputs. In the past, different methods have been used for identifying and eliminating these input variables. Normally, linear methods of Auto Correlation Function (ACF) and Partial Auto Correlation Function (PACF) have been adopted. For nonlinear physical systems e.g. hydrological systems, model inputs selected based on the linear correlation analysis among input and output variables cannot assure to capture the non-linearity in the system. In the present study, two of the non-linear methods have been explored for the Input Variable Selection (IVS). The linear method employing ACF and PACF is also used for comparison purposes. The first non-linear method utilizes a measure of the Mutual Information Criterion (MIC) to characterize the dependence between a potential model input and the output, which is a step wise input selection procedure. The second non-linear method is improvement over the first method which eliminates redundant inputs based on a partial measure of mutual information criterion (PMIC), which is also a step wise procedure. Further, the number of input variables to be considered for the development of ANN model was determined using the Principal Component Analysis (PCA), which previously used to be done by trial and error approach. The daily river flow data derived from Godavari River Basin @ Polavaram, Andhra Pradesh, India, and the daily average rainfall data of three rain gauge stations spatially distributed in Godavari River Basin have been employed to evaluate all the IVS methods for ANN hydrologic model development. Single hidden layer architecture trained using Levenberg-Marquardt algorithm (LMA) has been employed. A wide range of error statistics was used to evaluate the performance of all the models developed with different input selection methods in this study. It has been found that PCA helps to fix the number of input variables to be considered for the model development. The results obtained show that the ANN hydrologic model developed using the inputs based on the first non-linear method performed better than the model developed using the inputs based on the linear method. Further, the ANN hydrologic model developed using the inputs based on the second non-linear method performed the best among all the models developed on various IVS methods investigated in this study. It is recommended that PCA should first be used to determine the number of inputs to be selected and then the second non-linear method should be used to select the specific inputs for the development of ANN hydrologic model.

  5. Hydrologic Modeling of a Bioinfiltration Best Management Practice

    NASA Astrophysics Data System (ADS)

    Heasom, William; Traver, Robert G.; Welker, Andrea

    2006-10-01

    The goal of this research was to develop a methodology for modeling a bioinfiltration best management practice (BMP) built in a dormitory area on the campus of Villanova University in Pennsylvania. The objectives were to quantify the behavior of the BMP through the different seasons and rainfall events; better understand the physical processes governing the system's behavior; and develop design criteria. The BMP was constructed in 2001 by excavating within an existing traffic island, backfilling with a sand/soil mixture, and planting with salt tolerant grasses and shrubs native to the Atlantic shore. It receives runoff from the asphalt (0.26 hectare) and turf (0.27 hectare) surfaces of the watershed. Monitoring supported by the hydrologic model shows that the facility infiltrates a significant fraction of the annual precipitation, substantially reducing the delivery of nonpoint source pollution and erosive surges downstream. A hydrologic model was developed using HECHMS to represent the site and the BMP using Green-Ampt and kinematic wave methods. Instruments allow comparison of the modeled and measured water budget parameters. The model, incorporating seasonally variable parameters, predicts the volumes infiltrated and bypassed by the BMP, confirming the applicability of the selected methods for the analysis of bioinfiltration BMPs.

  6. Using the Workflow Engine TRIDENT as a Hydrologic Modeling Platform

    NASA Astrophysics Data System (ADS)

    Piasecki, Michael; Lu, Bo

    2010-05-01

    This is an invited contribution. Hydrologic communities around the world have developed a plethora of codes in a multitude of programming languages over the past few decades in order to assess environmental processes and to predict changes in the hydrologic realm. While these codes represent a vast amount of knowledge, expertise and resources spent and also have been extremely useful for the purposes they were designed, increasingly the realization emerges that a better coordination and coupling of both models among each other and also to data sources that drive the models is essential. The emergence of the idea of community models or integrated modeling systems (such as CSDMS, ESMF, or WRF) as well as coupling frameworks (such as openMI) have opened up new ways of thinking about how to link up legacy codes or integrate them into frameworks that allow for a more holistic modeling approach than before. This paper discusses the effort that has been undertaken to utilize a workflow engine (MicroSoft's TRIDENT system) for the purpose of designing a modeling environment that permits the seamless integration of data flows from source, to preparation (preprocessing), to ingestion, to model execution, to harvesting (postprocessing) and analysis of the generated result data through the design of workflow sequences. While this approach has the great benefit of documenting the modeling effort from A to Z so it is repeatable (this is very important for provenance) it also permits the creation and collection of actors (or activities) that can be reused by others either in the same or other workflow environments. For example, this allows for creating a number of alternative execution modules that can be linked together in a workflow sequence and then automatically compared via sets of post processing activities thus providing great time savings. We will be demonstrating how data sources can be directly tapped into via the use of web services, how they can be interpreted and prepared for model preparation (for example, to convert digital elevation model (DEM) data to a TIN and then a modeling grid for the delineated watershed), how legacy code can be integrated into the workflow, and how modular process actors van be liked to form a complex hydrologic modeling system, and how these numerical kernels can be executed. The resulting data volumes can then be stored in common data stores (such a netCDF) or be analyzed via statistical actors to automatically extract information about the generated data before it is been stored. We will address issues of scalability of these systems, and also offer an opinion on the ease of use and feasibility of a system like this for community modeling purposes.

  7. Development of a Hydrologic Modeling Platform Using a Workflow Engine

    NASA Astrophysics Data System (ADS)

    Piasecki, M.; Lu, B.

    2010-12-01

    Hydrologic communities around the world have developed a plethora of codes in a multitude of programming languages over the past few decades in order to assess environmental processes and to predict changes in the hydrologic realm. While these codes represent a vast amount of knowledge, expertise and resources spent and also have been extremely useful for the purposes they were designed, increasingly the realization emerges that a better coordination and coupling of both models among each other and also to data sources that drive the models is essential. The emergence of the idea of community models or integrated modeling systems (such as CSDMS, ESMF, or WRF) as well as coupling frameworks (such as openMI) have opened up new ways of thinking about how to link up legacy codes or integrate them into frameworks that allow for a more holistic modeling approach than before. This paper discusses the effort that has been undertaken to utilize a workflow engine (MicroSoft’s TRIDENT system) for the purpose of designing a modeling environment that permits the seamless integration of data flows from source, to preparation (preprocessing), to ingestion, to model execution, to harvesting (postprocessing) and analysis of the generated result data through the design of workflow sequences. While this approach has the great benefit of documenting the modeling effort from A to Z so it is repeatable (this is very important for provenance) it also permits the creation and collection of actors (or activities) that can be reused by others either in the same or other workflow environments. For example, this allows for creating a number of alternative execution modules that can be linked together in a workflow sequence and then automatically compared via sets of post processing activities thus providing great time savings. We will be demonstrating how data sources can be directly tapped into via the use of web services, how they can be interpreted and prepared for model preparation (for example, to convert digital elevation model (DEM) data to a TIN and then a modeling grid for the delineated watershed), how legacy code can be integrated into the workflow, and how modular process actors van be liked to form a complex hydrologic modeling system, and how these numerical kernels can be executed. The resulting data volumes can then be stored in common data stores (such a netCDF) or be analyzed via statistical actors to automatically extract information about the generated data before it is been stored. We will address issues of scalability of these systems, and also offer an opinion on the ease of use and feasibility of a system like this for community modeling purposes.

  8. An Integrated Hydrologic Bayesian Multi-Model Combination Framework: Confronting Input, parameter and model structural uncertainty in Hydrologic Prediction

    SciTech Connect

    Ajami, N K; Duan, Q; Sorooshian, S

    2006-05-05

    This paper presents a new technique--Integrated Bayesian Uncertainty Estimator (IBUNE) to account for the major uncertainties of hydrologic rainfall-runoff predictions explicitly. The uncertainties from the input (forcing) data--mainly the precipitation observations and from the model parameters are reduced through a Monte Carlo Markov Chain (MCMC) scheme named Shuffled Complex Evolution Metropolis (SCEM) algorithm which has been extended to include a precipitation error model. Afterwards, the Bayesian Model Averaging (BMA) scheme is employed to further improve the prediction skill and uncertainty estimation using multiple model output. A series of case studies using three rainfall-runoff models to predict the streamflow in the Leaf River basin, Mississippi are used to examine the necessity and usefulness of this technique. The results suggests that ignoring either input forcings error or model structural uncertainty will lead to unrealistic model simulations and their associated uncertainty bounds which does not consistently capture and represent the real-world behavior of the watershed.

  9. Status of Automatic Calibration for Hydrologic Models: Comparison with Multilevel Expert Calibration

    Microsoft Academic Search

    Hoshin Vijai Gupta; Soroosh Sorooshian; Patrice Ogou Yapo

    1999-01-01

    The usefulness of a hydrologic model depends on how well the model is calibrated. Therefore, the calibration procedure must be conducted carefully to maximize the reliability of the model. In general, manual procedures for calibration can be extremely time-consuming and frustrating, and this has been a major factor inhibiting the widespread use of the more sophisticated and complex hydrologic models.

  10. Approaches to handle data of low quality in hydrological modelling

    NASA Astrophysics Data System (ADS)

    Herma, Felix; Bárdossy, András; Hörning, Sebastian

    2015-04-01

    Hydrological modelling is an important tool for many applications in water resources engineering. It is widely used for designing storage reservoirs, flood protection measures or for prediction purposes. Therefore the quality of the required input data and the used hydrological model have a significant influence on the quality of the results and, consequently, on the reliability for the mentioned objectives above. Many factors affect the usefulness of data and models. In the first place, the number and spatial distribution of observation points build the base for all subsequent processes. Secondly, the quality of the input data, e.g. discharge, precipitation, has to be checked. It is known that rain gauge measurements underlie a high uncertainty, especially during periods with high rain intensities or snowfall. Last, the choice of the model according to the objective of its usage is the determining factor. Under such conditions a reliable assessment of the uncertainty is required. This contribution will focus on the described items and try to provide approaches on how to handle the presented problems. A hydrological model usually needs areal information of specific input data. The density and distribution of gauging stations lead to uncertainty if a spatial interpolation of the measures is applied. In the case of a high topographic variability within a catchment, uncertainties through the underestimation of rainfall amounts at exposed stations can occur. Drifts of rain or snow by wind are a central issue at this point. Common interpolation methods of precipitation are different forms of kriging which provide only the best estimate at the ungauged locations. However, these methods cannot correctly quantify the associated uncertainty of the estimation. Thus, this contribution applies a new method of random mixing of spatial random fields with the ability to incorporate equality and inequality constraints. Such conditions are applied to exposed gauging stations on different elevation levels. Instead of an interpolated kriging field, a number of simulated realizations of precipitation are passed to a hydrological model. This approach allows a better assessment of the uncertainty induced by the lack of spatial information at ungauged locations as well as the measurement inaccuracy under certain meteorological conditions at certain conditional points. The applied hydrological model has a lumped configuration and requires as input data just discharge, precipitation, temperature and evapotranspiration. Based on the comparatively simple model set-up it is checked if a distributed external pre-processing of the input data on a high spatial resolution yields a gain of information and an improved model performance. This is shown by using the example of temporal and spatial snow distributions. Hereby it is investigated if a simple model approach combined with an elaborated pre-processing is sufficient or even improving, for instance, the prediction of snowmelt caused flood events. The results are presented on the basis of a catchment in south-eastern Bavaria, Germany. The catchment is characterized by its high topographic variability. In addition, the measuring network is very unbalanced within the catchment and contains regions with very rare coverage of gauging stations. There, measured data of low quality can have an essential impact on spatial interpolations, model results and, finally, on the predictions.

  11. Quantifying and generalizing hydrologic responses to dam regulation using a statistical modeling approach

    NASA Astrophysics Data System (ADS)

    McManamay, Ryan A.

    2014-11-01

    Despite the ubiquitous existence of dams within riverscapes, much of our knowledge about dams and their environmental effects remains context-specific. Hydrology, more than any other environmental variable, has been studied in great detail with regard to dam regulation. While much progress has been made in generalizing the hydrologic effects of regulation by large dams, many aspects of hydrology show site-specific fidelity to dam operations, small dams (including diversions), and regional hydrologic regimes. A statistical modeling framework is presented as a predictive tool to quantify and generalize hydrologic responses to varying degrees of dam regulation at large spatial scales. In addition, the approach provides a method to expand sample sizes beyond that of traditional dam-hydrologic-effect analyses. Model performance was relatively poor with models explaining 10-31% of the variation in hydrologic responses. However, models had relatively high accuracies (61-89%) in classifying the direction of hydrologic responses as negative or positive. Responses of many hydrologic indices to dam regulation were highly dependent upon regional hydrology, the purpose of the dam, and the presence of diversion dams. In addition, models revealed opposite effects of dam regulation in systems regulated by individual dams versus many upstream dams, suggesting that the effects of dams may be countered by other dams in basins experiencing intensified cumulative disturbance. Results also suggested that particular contexts, including multipurpose dams, high cumulative regulation, diversions, and regions of unpredictable hydrology are all sources of increased error when predicting hydrologic responses to dams. Statistical models, such as the ones presented herein, show promise in their ability to generalize the directionality of hydrologic responses to dam regulation and provide parameter coefficients to inform future site-specific modeling efforts.

  12. Implications of complete watershed soil moisture measurements to hydrologic modeling

    NASA Technical Reports Server (NTRS)

    Engman, E. T.; Jackson, T. J.; Schmugge, T. J.

    1983-01-01

    A series of six microwave data collection flights for measuring soil moisture were made over a small 7.8 square kilometer watershed in southwestern Minnesota. These flights were made to provide 100 percent coverage of the basin at a 400 m resolution. In addition, three flight lines were flown at preselected areas to provide a sample of data at a higher resolution of 60 m. The low level flights provide considerably more information on soil moisture variability. The results are discussed in terms of reproducibility, spatial variability and temporal variability, and their implications for hydrologic modeling.

  13. Hidden Markov model segmentation of hydrological and enviromental time series

    E-print Network

    Ath. Kehagias

    2002-06-25

    Motivated by Hubert's segmentation procedure we discuss the application of hidden Markov models (HMM) to the segmentation of hydrological and enviromental time series. We use a HMM algorithm which segments time series of several hundred terms in a few seconds and is computationally feasible for even longer time series. The segmentation algorithm computes the Maximum Likelihood segmentation by use of an expectation / maximization iteration. We rigorously prove algorithm convergence and use numerical experiments, involving temperature and river discharge time series, to show that the algorithm usually converges to the globally optimal segmentation. The relation of the proposed algorithm to Hubert's segmentation procedure is also discussed.

  14. Modelling exploration of non-stationary hydrological system

    NASA Astrophysics Data System (ADS)

    Kim, Kue Bum; Kwon, Hyun-Han; Han, Dawei

    2015-04-01

    Traditional hydrological modelling assumes that the catchment does not change with time (i.e., stationary conditions) which means the model calibrated for the historical period is valid for the future period. However, in reality, due to change of climate and catchment conditions this stationarity assumption may not be valid in the future. It is a challenge to make the hydrological model adaptive to the future climate and catchment conditions that are not observable at the present time. In this study a lumped conceptual rainfall-runoff model called IHACRES was applied to a catchment in southwest England. Long observation data from 1961 to 2008 were used and seasonal calibration (in this study only summer period is further explored because it is more sensitive to climate and land cover change than the other three seasons) has been done since there are significant seasonal rainfall patterns. We expect that the model performance can be improved by calibrating the model based on individual seasons. The data is split into calibration and validation periods with the intention of using the validation period to represent the future unobserved situations. The success of the non-stationary model will depend not only on good performance during the calibration period but also the validation period. Initially, the calibration is based on changing the model parameters with time. Methodology is proposed to adapt the parameters using the step forward and backward selection schemes. However, in the validation both the forward and backward multiple parameter changing models failed. One problem is that the regression with time is not reliable since the trend may not be in a monotonic linear relationship with time. The second issue is that changing multiple parameters makes the selection process very complex which is time consuming and not effective in the validation period. As a result, two new concepts are explored. First, only one parameter is selected for adjustment while the other parameters are set as constant. Secondly, regression is made against climate condition instead of against time. It has been found that such a new approach is very effective and this non-stationary model worked very well both in the calibration and validation period. Although the catchment is specific in southwest England and the data are for only the summer period, the methodology proposed in this study is general and applicable to other catchments. We hope this study will stimulate the hydrological community to explore a variety of sites so that valuable experiences and knowledge could be gained to improve our understanding of such a complex modelling issue in climate change impact assessment.

  15. Spatiotemporal variability of hydrologic response : an entropy-based approach using a distributed hydrologic model

    E-print Network

    Castillo, Aldrich Edra

    2014-01-01

    Basin hydrologic response pertains to the partitioning of precipitation into stream-flow, evapotranspiration, and change in storage. The ability to explain or predict the response has many applications e.g. flood forecasting, ...

  16. Application of a Conceptual Hydrologic Model in Teaching Hydrologic Processes

    E-print Network

    Aghakouchak, Amir; Habib, Emad

    2010-01-01

    Teaching Hydrologic Processes* AMIR AGHAKOUCHAK, EMAD HABIB Department of Civil Engineering,engineering students who are better inspired by hands-on teachingteaching tools that can serve two main purposes: (1) aid engineering

  17. EFFICIENT HYDROLOGICAL TRACER-TEST DESIGN (EHTD) MODEL

    EPA Science Inventory

    Hydrological tracer testing is the most reliable diagnostic technique available for establishing flow trajectories and hydrologic connections and for determining basic hydraulic and geometric parameters necessary for establishing operative solute-transport processes. Tracer-test...

  18. Disaggregation, aggregation and spatial scaling in hydrological modelling

    NASA Astrophysics Data System (ADS)

    Becker, Alfred; Braun, Peter

    1999-04-01

    A typical feature of the land surface is its heterogeneity in terms of the spatial variability of land surface characteristics and parameters controlling physical/hydrological, biological, and other related processes. Different forms and degrees of heterogeneity need to be taken into account in hydrological modelling. The first part of the article concerns the conditions under which a disaggregation of the land surface into subareas of uniform or "quasihomogeneous" behaviour (hydrotopes or hydrological response units - HRUs) is indispensable. In a case study in northern Germany, it is shown that forests in contrast to arable land, areas with shallow groundwater in contrast to those with deep, water surfaces and sealed areas should generally be distinguished (disaggregated) in modelling, whereas internal heterogeneities within these hydrotopes can be assessed statistically, e.g., by areal distribution functions (soil water holding capacity, hydraulic conductivity, etc.). Models with hydrotope-specific parameters can be applied to calculate the "vertical" processes (fluxes, storages, etc.), and this, moreover, for hydrotopes of different area, and even for groups of distributed hydrotopes in a reference area (hydrotope classes), provided that the meteorological conditions are similar. Thus, a scaling problem does not really exist in this process domain. The primary domain for the application of scaling laws is that of lateral flows in landscapes and river basins. This is illustrated in the second part of the article, where results of a case study in Bavaria/Germany are presented and discussed. It is shown that scaling laws can be applied efficiently for the determination of the Instantaneous Unit Hydrograph (IUH) of the surface runoff system in river basins: simple scaling for basins larger than 43 km 2, and multiple scaling for smaller basins. Surprisingly, only two parameters were identified as important in the derived relations: the drainage area and, in some cases, the elevation a.s.l.. The scaling exponent was determined as equal or approximately equal to the exponent 0.566 in Hack's law. Therefore, it is suggested that there is some relation between the scaling laws and the fractal nature of river networks, and accordingly with the complex dynamics of the interacting hydrological and geomorphological processes in river basins.

  19. One-Water Hydrologic Flow Model (MODFLOW-OWHM)

    USGS Publications Warehouse

    Hanson, Randall T.; Boyce, Scott E.; Schmid, Wolfgang; Hughes, Joseph D.; Mehl, Steffen W.; Leake, Stanley A.; Maddock, Thomas, III; Niswonger, Richard G.

    2014-01-01

    The One-Water Hydrologic Flow Model (MF-OWHM) is a MODFLOW-based integrated hydrologic flow model (IHM) that is the most complete version, to date, of the MODFLOW family of hydrologic simulators needed for the analysis of a broad range of conjunctive-use issues. Conjunctive use is the combined use of groundwater and surface water. MF-OWHM allows the simulation, analysis, and management of nearly all components of human and natural water movement and use in a physically-based supply-and-demand framework. MF-OWHM is based on the Farm Process for MODFLOW-2005 (MF-FMP2) combined with Local Grid Refinement (LGR) for embedded models to allow use of the Farm Process (FMP) and Streamflow Routing (SFR) within embedded grids. MF-OWHM also includes new features such as the Surface-water Routing Process (SWR), Seawater Intrusion (SWI), and Riparian Evapotrasnpiration (RIP-ET), and new solvers such as Newton-Raphson (NWT) and nonlinear preconditioned conjugate gradient (PCGN). This IHM also includes new connectivities to expand the linkages for deformation-, flow-, and head-dependent flows. Deformation-dependent flows are simulated through the optional linkage to simulated land subsidence with a vertically deforming mesh. Flow-dependent flows now include linkages between the new SWR with SFR and FMP, as well as connectivity with embedded models for SFR and FMP through LGR. Head-dependent flows now include a modified Hydrologic Flow Barrier Package (HFB) that allows optional transient HFB capabilities, and the flow between any two layers that are adjacent along a depositional or erosional boundary or displaced along a fault. MF-OWHM represents a complete operational hydrologic model that fully links the movement and use of groundwater, surface water, and imported water for consumption by irrigated agriculture, but also of water used in urban areas and by natural vegetation. Supply and demand components of water use are analyzed under demand-driven and supply-constrained conditions. From large- to small-scale settings, MF-OWHM has the unique set of capabilities to simulate and analyze historical, present, and future conjunctive-use conditions. MF-OWHM is especially useful for the analysis of agricultural water use where few data are available for pumpage, land use, or agricultural information. The features presented in this IHM include additional linkages with SFR, SWR, Drain-Return (DRT), Multi-Node Wells (MNW1 and MNW2), and Unsaturated-Zone Flow (UZF). Thus, MF-OWHM helps to reduce the loss of water during simulation of the hydrosphere and helps to account for “all of the water everywhere and all of the time.” In addition to groundwater, surface-water, and landscape budgets, MF-OWHM provides more options for observations of land subsidence, hydraulic properties, and evapotranspiration (ET) than previous models. Detailed landscape budgets combined with output of estimates of actual evapotranspiration facilitates linkage to remotely sensed observations as input or as additional observations for parameter estimation or water-use analysis. The features of FMP have been extended to allow for temporally variable water-accounting units (farms) that can be linked to land-use models and the specification of both surface-water and groundwater allotments to facilitate sustainability analysis and connectivity to the Groundwater Management Process (GWM). An example model described in this report demonstrates the application of MF-OWHM with the addition of land subsidence and a vertically deforming mesh, delayed recharge through an unsaturated zone, rejected infiltration in a riparian area, changes in demand caused by deficiency in supply, and changes in multi-aquifer pumpage caused by constraints imposed through the Farm Process and the MNW2 Package, and changes in surface water such as runoff, streamflow, and canal flows through SFR and SWR linkages.

  20. Hydrological excitation of polar motion by different variables of the GLDAS models

    NASA Astrophysics Data System (ADS)

    Wi?ska, Ma?gorzata; Nastula, Jolanta

    Continental hydrological loading, by land water, snow, and ice, is an element that is strongly needed for a full understanding of the excitation of polar motion. In this study we compute different estimations of hydrological excitation functions of polar motion (Hydrological Angular Momentum - HAM) using various variables from the Global Land Data Assimilation System (GLDAS) models of land hydrosphere. The main aim of this study is to show the influence of different variables for example: total evapotranspiration, runoff, snowmelt, soil moisture to polar motion excitations in annual and short term scale. In our consideration we employ several realizations of the GLDAS model as: GLDAS Common Land Model (CLM), GLDAS Mosaic Model, GLDAS National Centers for Environmental Prediction/Oregon State University/Air Force/Hydrologic Research Lab Model (Noah), GLDAS Variable Infiltration Capacity (VIC) Model. Hydrological excitation functions of polar motion, both global and regional, are determined by using selected variables of these GLDAS realizations. First we compare a timing, spectra and phase diagrams of different regional and global HAMs with each other. Next, we estimate, the hydrological signal in geodetically observed polar motion excitation by subtracting the atmospheric -- AAM (pressure + wind) and oceanic -- OAM (bottom pressure + currents) contributions. Finally, the hydrological excitations are compared to these hydrological signal in observed polar motion excitation series. The results help us understand which variables of considered hydrological models are the most important for the polar motion excitation and how well we can close polar motion excitation budget in the seasonal and inter-annual spectral ranges.

  1. Chimeric hepatitis B virus (HBV)/hepatitis C virus (HCV) subviral envelope particles induce efficient anti-HCV antibody production in animals pre-immunized with HBV vaccine.

    PubMed

    Beaumont, Elodie; Roingeard, Philippe

    2015-02-18

    The development of an effective, affordable prophylactic vaccine against hepatitis C virus (HCV) remains a medical priority. The recently described chimeric HBV-HCV subviral envelope particles could potentially be used for this purpose, as they could be produced by industrial procedures adapted from those established for the hepatitis B virus (HBV) vaccine. We show here, in an animal model, that pre-existing immunity acquired through HBV vaccination does not influence the immunogenicity of the HCV E2 protein presented by these chimeric particles. Thus, these chimeric HBV-HCV subviral envelope particles could potentially be used as a booster in individuals previously vaccinated against HBV, to induce protective immunity to HCV. PMID:25596457

  2. Spatial calibration and temporal validation of flow for regional scale hydrologic modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Physically based regional scale hydrologic modeling is gaining importance for planning and management of water resources. Calibration and validation of such regional scale model is necessary before applying it for scenario assessment. However, in most regional scale hydrologic modeling, flow validat...

  3. Evaluation of global optimization algorithms for parameter calibration of a computationally intensive hydrologic model

    Microsoft Academic Search

    Xuesong Zhang; Raghavan Srinivasan; Kaiguang Zhao; Mike Van Liew

    2009-01-01

    With the popularity of complex hydrologic models, the time taken to run these models is increasing substantially. Comparing and evaluating the efficacy of different optimization algorithms for calibrating computationally intensive hydrologic models is becoming a nontrivial issue. In this study, five global optimization algorithms (genetic algorithms, shuffled complex evolution, particle swarm optimization, differential evolution, and artificial immune system) were tested

  4. Real Time Land-Surface Hydrologic Modeling Over Continental US

    NASA Technical Reports Server (NTRS)

    Houser, Paul R.

    1998-01-01

    The land surface component of the hydrological cycle is fundamental to the overall functioning of the atmospheric and climate processes. Spatially and temporally variable rainfall and available energy, combined with land surface heterogeneity cause complex variations in all processes related to surface hydrology. The characterization of the spatial and temporal variability of water and energy cycles are critical to improve our understanding of land surface-atmosphere interaction and the impact of land surface processes on climate extremes. Because the accurate knowledge of these processes and their variability is important for climate predictions, most Numerical Weather Prediction (NWP) centers have incorporated land surface schemes in their models. However, errors in the NWP forcing accumulate in the surface and energy stores, leading to incorrect surface water and energy partitioning and related processes. This has motivated the NWP to impose ad hoc corrections to the land surface states to prevent this drift. A proposed methodology is to develop Land Data Assimilation schemes (LDAS), which are uncoupled models forced with observations, and not affected by NWP forcing biases. The proposed research is being implemented as a real time operation using an existing Surface Vegetation Atmosphere Transfer Scheme (SVATS) model at a 40 km degree resolution across the United States to evaluate these critical science questions. The model will be forced with real time output from numerical prediction models, satellite data, and radar precipitation measurements. Model parameters will be derived from the existing GIS vegetation and soil coverages. The model results will be aggregated to various scales to assess water and energy balances and these will be validated with various in-situ observations.

  5. ANNIE - INTERACTIVE PROCESSING OF DATA BASES FOR HYDROLOGIC MODELS.

    USGS Publications Warehouse

    Lumb, Alan M.; Kittle, John L.

    1985-01-01

    ANNIE is a data storage and retrieval system that was developed to reduce the time and effort required to calibrate, verify, and apply watershed models that continuously simulate water quantity and quality. Watershed models have three categories of input: parameters to describe segments of a drainage area, linkage of the segments, and time-series data. Additional goals for ANNIE include the development of software that is easily implemented on minicomputers and some microcomputers and software that has no special requirements for interactive display terminals. Another goal is for the user interaction to be based on the experience of the user so that ANNIE is helpful to the inexperienced user and yet efficient and brief for the experienced user. Finally, the code should be designed so that additional hydrologic models can easily be added to ANNIE.

  6. Modelling of green roof hydrological performance for urban drainage applications

    NASA Astrophysics Data System (ADS)

    Locatelli, Luca; Mark, Ole; Mikkelsen, Peter Steen; Arnbjerg-Nielsen, Karsten; Bergen Jensen, Marina; Binning, Philip John

    2014-11-01

    Green roofs are being widely implemented for stormwater management and their impact on the urban hydrological cycle can be evaluated by incorporating them into urban drainage models. This paper presents a model of green roof long term and single event hydrological performance. The model includes surface and subsurface storage components representing the overall retention capacity of the green roof which is continuously re-established by evapotranspiration. The runoff from the model is described through a non-linear reservoir approach. The model was calibrated and validated using measurement data from 3 different extensive sedum roofs in Denmark. These data consist of high-resolution measurements of runoff, precipitation and atmospheric variables in the period 2010-2012. The hydrological response of green roofs was quantified based on statistical analysis of the results of a 22-year (1989-2010) continuous simulation with Danish climate data. The results show that during single events, the 10 min runoff intensities were reduced by 10-36% for 5-10 years return period and 40-78% for 0.1-1 year return period; the runoff volumes were reduced by 2-5% for 5-10 years return period and 18-28% for 0.1-1 year return period. Annual runoff volumes were estimated to be 43-68% of the total precipitation. The peak time delay was found to greatly vary from 0 to more than 40 min depending on the type of event, and a general decrease in the time delay was observed for increasing rainfall intensities. Furthermore, the model was used to evaluate the variation of the average annual runoff from green roofs as a function of the total available storage and vegetation type. The results show that even a few millimeters of storage can reduce the mean annual runoff by up to 20% when compared to a traditional roof and that the mean annual runoff is not linearly related to the storage. Green roofs have therefore the potential to be important parts of future urban stormwater management plans.

  7. Regional Hydrological Model Application In Benin Considering Environmental Change

    NASA Astrophysics Data System (ADS)

    Bormann, H.; Diekkrüger, B.

    The IMPETUS project (an integrated approach to the efficient management of scarce water resources in West Africa) aims to assess the effects of global change conditions on regional hydrological processes and on the water availability in Benin and Mo- rocco. The study presented here focuses on the simulation of the actual hydrological processes in Benin, West-Africa. Based on the measurements performed at the local scale (Aguima catchment, 30 km2) the TOPLATS model is adapted to the subhumid tropical conditions. While the distributed TOPLATS model can be validated on the local scale, the validation is limited at large scales due to the lack of distributed in- formation. But simulation results at the regional scale are of greater interest for water management issues. Therefore parameterisation schemes developed on the local scale can be used for regional model applications. By comparing the accuracy of locally measured data and operationally available data sources the uncertainty of regional model results can be assessed. Results of model applications to the Térou catchment (about 3.000 km2) are presented. Effects of land use classification as well as spatial resolution of land use and precipitation data are investigated. Using the adapted and validated model, regional scale scenarios will be simulated in the next project phase (upper Ouémé catchment, about 14.000 km2) considering land use and land cover change caused by anthropogenic reasons as well as climate change. By analysing a set of possible scenarios, the impact on the water cycle as well as related risks are assessed at the local and regional scale. The analysis will provide an important infor- mation demanded by local policy makers as well as international organisations.

  8. Hydrological excitation of polar motion by different variables from the GLDAS model

    NASA Astrophysics Data System (ADS)

    Wi?ska, Ma?gorzata; Nastula, Jolanta; Salstein, David

    2015-04-01

    Continental hydrological loading, by land water, snow, and ice, is an element that is strongly needed for a full understanding of the excitation of polar motion. In this study we compute different estimations of hydrological excitation functions of polar motion (Hydrological Angular Momentum - HAM) using various variables from the Global Land Data Assimilation System (GLDAS) model of the land-based hydrosphere. The main aim of this study is to show the influence of variables from different hydrological processes, including for example: total evapotranspiration, runoff, snowmelt, soil moisture to polar motion excitations in seasonal timescale. Hydrological excitation functions of polar motion, both global and regional, are determined by using selected variables of these GLDAS realizations. First we compare the timing, spectra and phase diagrams of different regional and global HAMs with each other. Next, we estimate, the hydrological signal in geodetically-observed polar motion excitation as a residual by subtracting the atmospheric - AAM (pressure + wind) and oceanic - OAM (bottom pressure + currents) contributions. Finally, the hydrological excitations are compared to these hydrological signal from the observed polar motion excitation series residuals. The results help us understand the relative importance for polar motion excitation of the individual variables from different hydrological processes, based on hydrological modeling. This method can allows us to estimate how well the polar motion excitation budget in the seasonal spectral ranges can be closed.

  9. Hydrological modelling of slopes from field monitoring data

    NASA Astrophysics Data System (ADS)

    Comegna, Luca; Damiano, Emilia; Greco, Roberto; Guida, Andrea; Olivares, Lucio; Picarelli, Luciano

    2013-04-01

    A simplified hydrological model of a steep slope covered with loose granular pyroclastic deposits is presented. The slope is located in the mountains northern of Naples, and the soil cover, constituted by layers of loose volcanic ashes and pumices with a total thickness of 2.5m, lays upon a fractured limestone bedrock. At the interface between the bedrock and the soil cover, a layer of weathered ashes, with significant clay fraction, is sometimes observed. The slope has a fairly regular inclination of 40°, and is covered by chestnut woods and thick brushwood growing in late spring. The inclination of the slope is comparable with the internal friction angle of the ashes, thus the equilibrium is possible thanks to the contribution offered to the shear strength by the soil suction in unsaturated conditions. Indeed, in December 1999, a landslide was triggered by prolonged and intense precipitations. As it frequently happens with similar pyroclastic covers, the triggered slide exhibited a flow-like behavior, covering 2km in few minutes, heavily hitting the nearby town of Cervinara (AV). Since then, the slope has been constantly monitored, and during the last two years an automated station with seven TDR probes for the measurement of soil water content, eight tensiometers for the measurement of soil suction, and a rain gauge, has been operating. The data, collected every two hours, allowed getting more insight of the hydrological behavior of the slope and building up an effective hydrological model. In the model, the layered soil profile has been replaced with a single homogeneous layer, with water retention curve estimated by coupling the values of water content and suction measured at various depths. A seasonal top boundary condition has been introduced, related to the annual cycle of the vegetation: the observed precipitations quickly caused changes of soil suction at the depth of -50cm during the entire year, with the exception of the period between the end of May and the early August. To reproduce the observed behavior of soil suction at the bottom of the profile, a linear reservoir model has been introduced as bottom boundary condition, related to the presence of a small aquifer in the fractured bedrock, which water table, affecting the hydraulic conditions of the soil cover, rapidly deepens during the dry season. The developed model, calibrated with the data of one year of observation, satisfactorily reproduces the observed soil hydraulic behaviour also during other periods.

  10. Assessing Hydrologic Impacts of Land Configuration Changes Using an Integrated Hydrologic Model at the Rocky Flats Environmental Technology Site, Colorado

    NASA Astrophysics Data System (ADS)

    Prucha, R. H.; Dayton, C. S.; Hawley, C. M.

    2002-12-01

    The Rocky Flats Environmental Technology Site (RFETS) in Golden, Colorado, a former Department of Energy nuclear weapons manufacturing facility, is currently undergoing closure. The natural semi-arid interaction between surface and subsurface flow at RFETS is complex and complicated by the industrial modifications to the flow system. Using a substantial site data set, a distributed parameter, fully-integrated hydrologic model was developed to assess the hydrologic impact of different hypothetical site closure configurations on the current flow system and to better understand the integrated hydrologic behavior of the system. An integrated model with this level of detail has not been previously developed in a semi-arid area, and a unique, but comprehensive, approach was required to calibrate and validate the model. Several hypothetical scenarios were developed to simulate hydrologic effects of modifying different aspects of the site. For example, some of the simulated modifications included regrading the current land surface, changing the existing surface channel network, removing subsurface trenches and gravity drain flow systems, installing a slurry wall and geotechnical cover, changing the current vegetative cover, and converting existing buildings and pavement to permeable soil areas. The integrated flow model was developed using a rigorous physically-based code so that realistic design parameters can simulate these changes. This code also permitted evaluation of changes to complex integrated hydrologic system responses that included channelized and overland flow, pond levels, unsaturated zone storage, groundwater heads and flow directions, and integrated water balances for key areas. Results generally show that channel flow offsite decreases substantially for different scenarios, while groundwater heads generally increase within the reconfigured industrial area most of which is then discharged as evapotranspiration. These changes have significant implications to site closure and operation.

  11. Parameterisation, calibration and validation of distributed hydrological models

    NASA Astrophysics Data System (ADS)

    Refsgaard, Jens Christian

    1997-11-01

    This paper emphasizes the different requirements for calibration and validation of lumped and distributed models. On the basis of a theoretically founded modelling protocol, the different steps in distributed hydrological modelling are illustrated through a case study based on the MIKE SHE code and the 440 km 2 Karup catchment in Denmark. The importance of a rigorous and purposeful parameterisation is emphasized in order to get as few "free" parameters as possible for which assessments through calibration are required. Calibration and validation using a split-sample procedure were carried out for catchment discharge and piezometric heads at seven selected observation wells. The validated model was then used for two further validation tests. Firstly, model simulations were compared with observations from three additional discharge sites and four additional wells located within the catchment. This internal validation showed significantly poorer results compared to the calibration/validation sites. Secondly, the validated model based on a 500 m model grid was used to generate three additional models with 1000 m, 2000 m and 4000 m grids through interpolation of model parameters. The results from the multi-scale validation suggested that a maximum grid size of 1000 m should be used for simulations of discharge and ground-water heads, while the results deteriorated with coarser model grids.

  12. Building Community Around Hydrologic Data Models Within CUAHSI

    NASA Astrophysics Data System (ADS)

    Maidment, D.

    2007-12-01

    The Consortium of Universities for the Advancement of Hydrologic Science, Inc (CUAHSI) has a Hydrologic Information Systems project which aims to provide better data access and capacity for data synthesis for the nation's water information, both that collected by academic investigators and that collected by water agencies. These data include observations of streamflow, water quality, groundwater levels, weather and climate and aquatic biology. Each water agency or research investigator has a unique method of formatting their data (syntactic heterogeneity) and describing their variables (semantic heterogeneity). The result is a large agglomeration of data in many formats and descriptions whose full content is hard to interpret and analyze. CUAHSI is helping to resolve syntactic heterogeneity through the development of WaterML, a standard XML markup language for communicating water observations data through web services, and a standard relational database structure for archiving data called the Observations Data Model. Variables in these data archiving and communicating systems are indexed against a controlled vocabulary of descriptive terms to provide the capacity to synthesize common data types from disparate data sources.

  13. Viral hepatitis. HBV cure--can we pin our hopes on immunotherapy?

    PubMed

    Yang, Hung-Chih; Kao, Jia-Horng

    2015-03-01

    Therapeutic vaccines are considered to be able to reverse the dysfunctional immune state of chronic hepatitis B and thus hold the promise for HBV cure. Martin et al. developed a novel adenovirus-based therapeutic vaccine TG1050 and demonstrated its induction of long-lasting antiviral CD8+ T-cell immunity in mouse models of HBV persistence. PMID:25623202

  14. Testing calibration routines for LISFLOOD, a distributed hydrological model

    NASA Astrophysics Data System (ADS)

    Pannemans, B.

    2009-04-01

    Traditionally hydrological models are considered as difficult to calibrate: their highly non-linearity results in rugged and rough response surfaces were calibration algorithms easily get stuck in local minima. For the calibration of distributed hydrological models two extra factors play an important role: on the one hand they are often costly on computation, thus restricting the feasible number of model runs; on the other hand their distributed nature smooths the response surface, thus facilitating the search for a global minimum. Lisflood is a distributed hydrological model currently used for the European Flood Alert System - EFAS (Van der Knijff et al, 2008). Its upcoming recalibration over more then 200 catchments, each with an average runtime of 2-3 minutes, proved a perfect occasion to put several existing calibration algorithms to the test. The tested routines are Downhill Simplex (DHS, Nelder and Mead, 1965), SCEUA (Duan et Al. 1993), SCEM (Vrugt et al., 2003) and AMALGAM (Vrugt et al., 2008), and they were evaluated on their capability to efficiently converge onto the global minimum and on the spread in the found solutions in repeated runs. The routines were let loose on a simple hyperbolic function, on a Lisflood catchment using model output as observation, and on two Lisflood catchments using real observations (one on the river Inn in the Alps, the other along the downstream stretch of the Elbe). On the mathematical problem and on the catchment with synthetic observations DHS proved to be the fastest and the most efficient in finding a solution. SCEUA and AMALGAM are a slower, but while SCEUA keeps converging on the exact solution, AMALGAM slows down after about 600 runs. For the Lisflood models with real-time observations AMALGAM (hybrid algorithm that combines several other algorithms, we used CMA, PSO and GA) came as fastest out of the tests, and giving comparable results in consecutive runs. However, some more work is needed to tweak the stopping criteria. SCEUA is a bit slower, but has very transparent stopping rules. Both have closed in on the minima after about 600 runs. DHS equals only SCEUA on convergence speed. The stopping criteria we applied so far are too strict, causing it to stop too early. SCEM converges 5-6 times slower. This is a high price for the parameter uncertainty analysis that is simultaneously done. The ease with which all algorithms find the same optimum suggests that we are dealing with a smooth and relatively simple response surface. This leaves room for other deterministic calibration algorithms being smarter than DHS in sliding downhill. PEST seems promising but sofar we haven't managed to get it running with LISFLOOD. • Duan, Q.; Gupta, V. & Sorooshian, S., 1993, Shuffled complex evolution approach for effective and efficient global minimization, J Optim Theory Appl, Kluwer Academic Publishers-Plenum Publishers, 76, 501-521 • Nelder, J. & Mead, R., 1965, A simplex method for function minimization, Comput. J., 7, 308-313 • Van Der Knijff, J. M.; Younis, J. & De Roo, A. P. J., 2008, LISFLOOD: a GIS-based distributed model for river basin scale water balance and flood simulation, International Journal of Geographical Information Science, • Vrugt, J.; Gupta, H.; Bouten, W. & Sorooshian, S., 2003, A Shuffled Complex Evolution Metropolis algorithm for optimization and uncertainty assessment of hydrologic model parameters, Water Resour. Res., 39 • Vrugt, J.; Robinson, B. & Hyman, J., 2008, Self-Adaptive Multimethod Search for Global Optimization in Real-Parameter Spaces, IEEE Trans Evol Comput, IEEE,

  15. Hydrologic Modeling of Conservation Farming Practices on the Palouse

    NASA Astrophysics Data System (ADS)

    van Wie, J.; Adam, J. C.; Ullman, J.

    2009-12-01

    The production of dryland crops such as wheat and barley in a semi-arid region requires a reliable and adequate water supply. This supply of water available for crop use is of heightened importance in areas such as the Palouse region of eastern Washington and northern Idaho where the majority of annual rainfall occurs during the winter months and must be retained in the soil through the dry summer growing season. Farmers can increase conservation of water at the field and watershed scales through the adoption of best management practices that incorporate tillage and crop residue management. This research analyzes conservation farming practices that may be implemented by representing them in a watershed-scale hydrologic model in order to determine whether these practices will effectively save water so that a stable crop yield may be insured. The Distributed Hydrology Soil Vegetation Model (DHSVM) is applied and calibrated to represent the physical changes to infiltration, evaporation, and runoff that result from altered soil and vegetation characteristics brought on by management practices. The model is calibrated with field observations at the basin scale as well as the point scale over individual plots that are under various implementations of conservation management scenarios. Conservation practices are accounted for in DHSVM by adjusting input parameters such as the porosity, roughness, and hydraulic conductivity of the soil to characterize varying levels of tillage. Vegetation parameters such as leaf area index and albedo are altered to represent different amounts of crop residue left on the field through the winter months. After calibration, the model is applied over the entire basin under scenarios representing traditional agricultural methods and a region-wide shift to conservation practices. The resulting water balance suggests that there is a potential to retain water in the seed-zone during the winter months by decreasing evaporation and runoff through the use of conservation in tillage and residue management.

  16. Evaluating and developing parameter optimization and uncertainty analysis methods for a computationally intensive distributed hydrological model

    E-print Network

    Zhang, Xuesong

    2009-05-15

    EVALUATING AND DEVELOPING PARAMETER OPTIMIZATION AND UNCERTAINTY ANALYSIS METHODS FOR A COMPUTATIONALLY INTENSIVE DISTRIBUTED HYDROLOGICAL MODEL A Dissertation by XUESONG ZHANG Submitted to the Office of Graduate Studies... ANALYSIS METHODS FOR A COMPUTATIONALLY INTENSIVE DISTRIBUTED HYDROLOGICAL MODEL A Dissertation by XUESONG ZHANG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree...

  17. HYDROLOGIC EVALUATION OF LANDFILL PERFORMANCE (HELP) MODEL: USER'S GUIDE FOR VERSION 3

    EPA Science Inventory

    The Hydrologic Evaluation of Landfill Performance (HELP) computer program is a quasi-two-dimensional hydrologic model of water movement across, into, through and out of landfills. he model accepts weather, soil and design data. andfill systems including various combinations of ve...

  18. Improved cavity detection from coupled seismic and hydrologic models

    NASA Astrophysics Data System (ADS)

    Desilets, S.; Bonal, N. D.; Desilets, D.

    2012-12-01

    Seismic methods hold much promise for cavity detection, but the results from field measurements have been frustratingly inconsistent between field sites. The reasons for the inconsistencies are not fully understood, though water saturation in the near-surface may be responsible to some extent. The conventional approach has been to focus on reflections and refractions generated from the impedance contrast of the cavity wall itself, where the dimensions and geometry of the cavity should play key roles. Here, we instead focus on the influence of impedance contrasts that are generated by hydrologic processes in the adjacent porous medium. These contrasts can potentially increase or decrease the reflection/refraction footprint of the cavity itself. Detectable hydrologic anomalies can be created by the simple drainage of groundwater into the cavity (initially saturated conditions) or by the creation of a capillary barrier around the cavity (initially unsaturated conditions). Because both processes ultimately involve unsaturated conditions we use HYDRUS 2D to numerically solve the Richard's equation and simulate flow through the vadose zone. Using the generated soil moisture information and Brutsaert's (1964) saturation-velocity relation, we constructed velocity models. Our simulations suggest several scenarios where changes in saturation due to the cavity may be utilized to enhance cavity detection with seismic waves. One simulation is for unsaturated conditions in the top 10 meters of soil, where capillary forces exert a major influence on velocity. In this case, the impedance contrast is greatest for near-saturated soils. Deeper cavities (100s of meters) in permeable saturated materials are also favorable due to the sharp impedance contrast between saturated and unsaturated material. Our hydrology-determined velocity models are then used in finite-difference wave propagation simulations to determine the effects on seismic waves at various depths and saturations. Saturation features in the seismic data can then be utilized to detect cavities rather than relying on traditional yet inconsistent reflection/refraction approach. In ongoing work, we will ground-truth these models with both laboratory and experimental results. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  19. A METHODOLOGY FOR ESTIMATING UNCERTAINTY OF A DISTRIBUTED HYDROLOGIC MODEL: APPLICATION TO POCONO CREEK WATERSHED

    EPA Science Inventory

    Utility of distributed hydrologic and water quality models for watershed management and sustainability studies should be accompanied by rigorous model uncertainty analysis. However, the use of complex watershed models primarily follows the traditional {calibrate/validate/predict}...

  20. Evaluating snow models with varying process representations for hydrological applications

    NASA Astrophysics Data System (ADS)

    Magnusson, Jan; Wever, Nander; Essery, Richard; Helbig, Nora; Winstral, Adam; Jonas, Tobias

    2015-04-01

    Much effort has been invested in developing snow models over several decades, resulting in a wide variety of empirical and physically based snow models. For the most part, these models are built on similar principles. The greatest differences are found in how each model parameterizes individual processes (e.g., surface albedo and snow compaction). Parameterization choices naturally span a wide range of complexities. In this study, we evaluate the performance of different snow model parameterizations for hydrological applications using an existing multimodel energy-balance framework and data from two well-instrumented alpine sites with seasonal snow cover. We also include two temperature-index snow models and an intensive, physically based multilayer snow model in our analyses. Our results show that snow mass observations provide useful information for evaluating the ability of a model to predict snowpack runoff, whereas snow depth data alone are not. For snow mass and runoff, the energy-balance models appear transferable between our two study sites, a behavior which is not observed for snow surface temperature predictions due to site-specificity of turbulent heat transfer formulations. Errors in the input and validation data, rather than model formulation, seem to be the greatest factor affecting model performance. The three model types provide similar ability to reproduce daily observed snowpack runoff when appropriate model structures are chosen. Model complexity was not a determinant for predicting daily snowpack mass and runoff reliably. Our study shows the usefulness of the multimodel framework for identifying appropriate models under given constraints such as data availability, properties of interest and computational cost.

  1. A simple hydrologically based model of land surface water and energy fluxes for general circulation models

    Microsoft Academic Search

    Xu Liang; Dennis P. Lettenmaier; S. J. Burges

    1994-01-01

    A generalization of the single soil layer variable infiltration capacity (VIC) land surface hydrological model previously implemented in the Geophysical Fluid Dynamics Laboratory (GFDL) general circulation model (GCM) is described. The new model is comprised of a two-layer characterization of the soil column, and uses an aerodynamic representation of the latent and sensible heat fluxes at the land surface. The

  2. Modeling Floodplain Inundation by Integration of Hydrological With Hydraulic Model, Case Study: Muda River, Kedah

    Microsoft Academic Search

    RABIE ALI HUSSEIN; AMINUDDIN AB; NOR AZAZI ZAKARIA; SANUSI S. AHMAD; ZORKEFLEE ABU HASAN

    River flood is recurrent natural phenomena in tropics and sub tropical climate. Among all kinds of natural hazards of the world flood is probably most wide spread, frequent and destructive. In recent years, remote sensing and GIS has become the key tool for flood modeling. This paper will discuss the modeling of floodplain by integrated hydrological with hydraulic model. The

  3. Forecasting the behaviour of complex landslides with a spatially distributed hydrological model

    NASA Astrophysics Data System (ADS)

    Malet, J.-P.; van Asch, Th. W. J.; van Beek, R.; Maquaire, O.

    2005-01-01

    The relationships between rainfall, hydrology and landslide movement are often difficult to establish. In this context, ground-water flow analyses and dynamic modelling can help to clarify these complex relations, simulate the landslide hydrological behaviour in real or hypothetical situations, and help to forecast future scenarios based on environmental change. The primary objective of this study is to investigate the possibility of including more temporal and spatial information in landslide hydrology forecasting, by using a physically based spatially distributed model. Results of the hydrological and geomorphological investigation of the Super-Sauze earthflow, one of the persistently active landslide occurring in clay-rich material of the French Alps, are presented. Field surveys, continuous monitoring and interpretation of the data have shown that, in such material, the groundwater level fluctuates on a seasonal time scale, with a strong influence of the unsaturated zone. Therefore a coupled unsaturated/saturated model, incorporating Darcian saturated flow, fissure flow and meltwater flow is needed to adequately represent the landslide hydrology. The conceptual model is implemented in a 2.5-D spatially distributed hydrological model. The model is calibrated and validated on a multi-parameters database acquired on the site since 1997. The complex time-dependent and three-dimensional groundwater regime is well described, in both the short- and long-term. The hydrological model is used to forecast the future hydrological behaviour of the earthflow in response to potential environmental changes.

  4. Test of Landsat-based urban hydrologic modeling

    NASA Technical Reports Server (NTRS)

    Jackson, T. J.; Ragan, R. M.; Fitch, W. N.

    1977-01-01

    A description is presented of the Fourmile Run Study which has been conducted to evaluate Landsat remote sensing as a method of defining input parameters required by urban hydrologic planning models. The evaluation was a part of water resource planning investigations concerning the Fourmile Run Watershed. The investigations involved an examination of the relationship between urban development and flooding for the Fourmile Run Basin. The study indicates that Landsat data provide a suitable source of land cover data for investigations conducted at the planning level. An estimation of the percentage of impervious area on the basis of Landsat data is less expensive than a use of aerial photos in planning studies. Only limited success could be achieved when Landsat data were used for smaller areal units.

  5. France-wide future evolution of discharges for the next decades: a multi-RCP/GCM/hydrological model and calibration exercise

    NASA Astrophysics Data System (ADS)

    Thirel, Guillaume; Nicolas, Madeleine; Beersma, Jules

    2015-04-01

    Due to complex interactions between atmosphere, vegetation, oceans, land and human beings, climate is continually evolving. The last IPCC report highlighted that by the end of the 21st century, dramatic climate modifications may occur: in Europe, the temperature is expected to increase by several degrees, and the evolution of precipitation is more uncertain. These changes will impact the water cycle, and as a consequence river discharges, which can potentially impact economical, industrial and touristic activities as well as the ecosphere. In order to provide new insights for hydrology in France, we propose to assess the impact of climate change on discharge module, high and low flows for over 800 river points in France. For this, the last CMIP5 projections are used for the periods 2021-2050 and 2071-2100. This country-wide evaluation, a compromise between basin-based and continental studies usually performed in literature, is of the utmost importance due to the numerous interconnections of water uses inside France. For this work, the 4 IPCC Representative Concentration Pathways (RCPs) were utilized to drive part or all of 27 Global Circulation Models (GCMs) or versions of GCMs, for which one to ten different runs were available. This represents a total of 183 climatic projections that were then downscaled using the Advanced Delta Change (ADC) method, a statistical method calibrated between a past reference period and the two future periods. In this study, we applied the ADC to an 8x8 km 52-year meteorological reanalysis available over France. Six global conceptual hydrological models (GR4J, GR5J, GR6J, MORD6, TOPMO, HBV0) were used to produce the hydrological projections, allowing the representation of uncertainty in hydrological modelling. Moreover, one of the hydrological models was calibrated with several objective functions and over contrasted climatic periods. By having several methods or models for every step (except regarding the downscaling method), we aimed at representing the uncertainty in all the components of the modelling chain. We will present the future evolution of climate and discharge over France. Regarding discharges, we will focus on several indicators dedicated to high and low flows, to discharge module and regimes. If possible, the intensity of the sources of variability from the different components of the modelling chain will be quantified.

  6. Urban Hydrology and Water Quality Modeling - Resolution Modeling Comparison for Water Quantity and Quality

    NASA Astrophysics Data System (ADS)

    Fry, T. J.; Maxwell, R. M.

    2014-12-01

    Urbanization presents challenging water resource problems for communities worldwide. The hydromodifications associated with urbanization results in increased runoff rates and volumes and increased peak flows. These hydrologic changes can lead to increased erosion and stream destabilization, decreased evapotranspiration, decreased ground water recharge, increases in pollutant loading, and localized anthropogenic climate change or Urban Heat Islands. Stormwater represents a complex and dynamic component of the urban water cycle that requires careful mitigation. With the implementation of Phase II rules under the CWA, stormwater management is shifting from a drainage-efficiency focus to a natural systems focus. The natural system focus, referred to as Low Impact Development (LID), or Green Infrastructure, uses best management practices (BMPs) to reduce the impacts caused by urbanization hydromodification. Large-scale patterns of stormwater runoff from urban environments are complex and it is unclear what the large-scale impacts of green infrastructure are on the water cycle. High resolution physically based hydrologic models can be used to more accurately simulate the urban hydrologic cycle. These types of models tend to be more dynamic and allow for greater flexibility in evaluating and accounting for various hydrologic processes in the urban environment that may be lost with lower resolution conceptual models. We propose to evaluate the effectiveness of high resolution models to accurately represent and determine the urban hydrologic cycle with the overall goal of being able to accurately assess the impacts of LID BMPs in urban environments. We propose to complete a rigorous model intercomparison between ParFlow and FLO-2D. Both of these models can be scaled to higher resolutions, allow for rainfall to be spatially and temporally input, and solve the shallow water equations. Each model is different in the way it accounts for infiltration, initial abstraction losses, and urban structures. The intercomparison of these models will help identify key areas of urban hydrology that can be used by agencies in developing design guidelines used in assessing LIDs in urban environments.

  7. MODIS-derived Potential Evapotranspiration Estimates for Operational Hydrologic Modeling

    NASA Astrophysics Data System (ADS)

    Kim, J.; Hogue, T.

    2005-12-01

    The current SACramento Soil Moisture Accounting Model (SAC-SMA), used by the National Weather Service, is the primarily model for hydrologic forecasting across the United States. Potential evapotranspiration (PET), one of the required inputs, remains rather simplistic. The model traditionally uses a regional pan evaporation estimate due to the difficulty in acquiring more sophisticated measurements. This study explores an alternative methodology using only remote sensing information to capture the monthly mean distribution of potential evapotranspiration (PET) for the SAC-SMA model. We apply a simple scheme proposed by Jiang and Islam (2005) to estimate the net radiation and estimate PET within the context of the Priestley-Taylor equation using data gathered from the MODIS Terra platform. PET estimates from the MODIS data are compared with those derived from Oklahoma Mesonet ground-based measurements and traditional pan evaporation estimates. Preliminary results will be presented for the Illinois River basin at Watts (OK) identified as part of the National Weather Service's Distributed Modeling Intercomparison Project (DMIP). The resultant streamflow simulations will illustrate the sensitivity of the SAC-SMA model to potential evaporation inputs from different sources and the possibility of the application of a stand-alone PET method for un-gauged basins.

  8. A coupled energy transport and hydrological model for urban canopies

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Bou-Zeid, E.; Smith, J. A.

    2011-12-01

    Urban land-atmosphere interaction has been attracting more research efforts in order to understand the complex physics of flow and mass and heat transport in urban surfaces and the lower urban atmosphere. In this work, we developed and implemented a new physically-based single-layer urban canopy model, coupling the surface exchange of energy and the subsurface transport of water/soil moisture. The new model incorporates sub-facet heterogeneity for each urban surface (roof, wall or ground). This better simulates the energy transport in urban canopy layers, especially over low-intensity built (suburban type) terrains that include a significant fraction of vegetated surfaces. We implemented detailed urban hydrological models for both natural terrains (bare soil and vegetation) and porous engineered materials with water-holding capacity (concrete, gravel, etc). The skill of the new scheme was tested against experimental data collected through a wireless sensor network deployed over the campus of Princeton University. The model performance was found to be robust and insensitive to changes in weather conditions or seasonal variability. Predictions of the volumetric soil water content were also in good agreement with field measurements, highlighting the model capability of capturing subsurface water transport for urban lawns. The new model was also applied to a case study assessing different strategies, i.e. white versus green roofs, in the mitigation of urban heat island effect.

  9. Satellite Remote Sensing and Hydrological Modeling for Flood Inundation Mapping in Lake Victoria Basin: Implications for Hydrologic Prediction in Ungauged Basins

    NASA Astrophysics Data System (ADS)

    Khan, S. I.; Hong, Y.; Wang, J.; Yilmaz, K. K.; Gourley, J. J.; Adler, R. F.; Brakenridge, G. R.; Policelli, F.; Habib, S.; Irwin, D.

    2009-12-01

    Floods are among the most catastrophic natural disasters around the globe impacting human lives and infrastructure. Implementation of a flood prediction system can potentially reduce these losses. Typically, the set up and calibration of a hydrologic model requires in situ observations (e.g. rain gauges and stream gauges). Satellite remote sensing data have emerged as viable alternatives or supplements to in situ observations due to their coverage over ungauged regions. The focus of this study is to utilize the best available satellite products and integrate them in a state-of-the-art hydrologic model to characterize the spatial extent of flooding and associated hazards over sparsely-gauged or ungauged basins. This study presents a methodology based entirely on satellite remote sensing data to calibrate a hydrologic model, simulate the spatial extent of flooding, and evaluate the probability of detecting inundated areas. A raster-based distributed hydrologic model, CREST, was implemented for the Nzoia basin, a sub-basin of Lake Victoria (Africa). MODIS- and ASTER-based flood inundation maps were retrieved over the region and used to benchmark the distributed hydrologic model simulations of streamflow and inundation areas. The analysis showed the applicability of integrating satellite data products as input for a distributed hydrological model as well as direct estimation of flood extent maps. The quantification of flooding spatial extent through orbital sensors can help to evaluate hydrologic models and hence potentially improve hydrologic prediction and flood management strategies in ungauged catchments.

  10. Hydrologic Characterization for Spring Creek and Hydrologic Budget and Model Scenarios for Sheridan Lake, South Dakota, 1962-2007

    USGS Publications Warehouse

    Driscoll, Daniel G.; Norton, Parker A.

    2009-01-01

    The U.S. Geological Survey cooperated with South Dakota Game, Fish and Parks to characterize hydrologic information relevant to management of water resources associated with Sheridan Lake, which is formed by a dam on Spring Creek. This effort consisted primarily of characterization of hydrologic data for a base period of 1962 through 2006, development of a hydrologic budget for Sheridan Lake for this timeframe, and development of an associated model for simulation of storage deficits and drawdown in Sheridan Lake for hypothetical release scenarios from the lake. Historically, the dam has been operated primarily as a 'pass-through' system, in which unregulated outflows pass over the spillway; however, the dam recently was retrofitted with an improved control valve system that would allow controlled releases of about 7 cubic feet per second (ft3/s) or less from a fixed depth of about 60 feet (ft). Development of a hydrologic budget for Sheridan Lake involved compilation, estimation, and characterization of data sets for streamflow, precipitation, and evaporation. The most critical data need was for extrapolation of available short-term streamflow records for Spring Creek to be used as the long-term inflow to Sheridan Lake. Available short-term records for water years (WY) 1991-2004 for a gaging station upstream from Sheridan Lake were extrapolated to WY 1962-2006 on the basis of correlations with streamflow records for a downstream station and for stations located along two adjacent streams. Comparisons of data for the two streamflow-gaging stations along Spring Creek indicated that tributary inflow is approximately proportional to the intervening drainage area, which was used as a means of estimating tributary inflow for the hydrologic budget. Analysis of evaporation data shows that sustained daily rates may exceed maximum monthly rates by a factor of about two. A long-term (1962-2006) hydrologic budget was developed for computation of reservoir outflow from Sheridan Lake for the historical pass-through operating system. Two inflow components (stream inflow and precipitation) and one outflow component (evaporation) were considered. The hydrologic budget uses monthly time steps within a computational year that includes two 6-month periods - May through October, for which evaporation is accounted for, and November through April, when evaporation is considered negligible. Results indicate that monthly evaporation rates can substantially exceed inflow during low-flow periods, and potential exists for outflows to begin approaching zero-flow conditions substantially prior to the onset of zero-inflow conditions, especially when daily inflow and evaporation are considered. Results also indicate that September may be the month for greatest potential benefit for enhancing fish habitat and other ecosystem values in downstream reaches of Spring Creek with managed releases of cool water. Computed monthly outflows from Sheridan Lake for September are less than 1.0 ft3/s for 8 of the 44 years (18 percent) and are less than 2.0 ft3/s for 14 of the 44 years (32 percent). Conversely, none of the computed outflows for May are less than 2.0 ft3/s. A short-term (July through September 2007) data set was used to calculate daily evaporation from Sheridan Lake and to evaluate the applicability of published pan coefficients. Computed values of pan coefficients of approximately 1.0 and 1.1 for two low-flow periods are larger than the mean annual pan coefficient of 0.74 for the area that is reported in the literature; however, the computed values are consistent with pan coefficients reported elsewhere for similar late summer and early fall periods. Thus, these results supported the use of variable monthly pan coefficients for the long-term hydrologic budget. A hydrologic model was developed using the primary components of the hydrologic budget and was used to simulate monthly storage deficits and drawdown for Sheridan Lake using hypothetical

  11. Assessing the hydropower potential of ungauged watersheds in Iceland using hydrological modeling and satellite retrieved snow cover images

    NASA Astrophysics Data System (ADS)

    Finger, David

    2015-04-01

    About 80% of the domestic energy production in Iceland comes from renewable energies. Hydropower accounts for about 20% this production, representing about 75% of the total electricity production in Iceland. In 2008 total electricity production from hydropower was about 12.5 TWh a-1, making Iceland a worldwide leader in hydropower production per capita. Furthermore, the total potential of hydroelectricity in Iceland is estimated to amount up to 220 TWh a-1. In this regard, hydrological modelling is an essential tool to adapt a sustainable management of water resources and estimate the potential of possible new sites for hydropower production. We used the conceptual lumped Hydrologiska Byråns Vattenbalansavdelning model (HBV) to estimate the potential of hydropower production in two remote areas in north-eastern Iceland (Leirdalshraun, a 274 km2 area above 595 m asl and Hafralónsá, a 946 km2 area above 235 m asl). The model parameters were determined by calibrating the model with discharge data from gauged sub catchments. Satellite snow cover images were used to constrain melt parameters of the model and assure adequate modelling of snow melt in the ungauged areas. This was particularly valuable to adequately estimate the contribution of snow melt, rainfall runoff and groundwater intrusion from glaciers outside the topographic boundaries of the selected watersheds. Runoff from the entire area potentially used for hydropower exploitation was estimated using the parameter sets of the gauged sub-catchments. Additionally, snow melt from the ungauged areas was validated with satellite based snow cover images, revealing a robust simulation of snow melt in the entire area. Based on the hydrological modelling the total amount of snow melt and rainfall runoff available in Leirdalshraun and Hafralónsá amounts up to 700 M m3 a-1 and 1000 M m3 a-1, respectively. These results reveal that the total hydropower potential of the two sites amounts up to 1.2 TWh a-1 hydroelectricity, accounting for about 10% of the current production in Iceland. These result are of eminent importance to embed sustainable and resilient based water management in discussions concerning future plans of national energy production.

  12. Simulating hydrological responses with a physically based model in a mountainous watershed

    NASA Astrophysics Data System (ADS)

    Xu, Q.; Chen, X.; Bi, J.; Ouyang, R.; Ren, L.

    2015-06-01

    A physical and distributed approach was proposed by Reggiani et al. (1998) to describe the hydrological responses at the catchment scale. The rigorous balance equations for mass, momentum, energy and entropy are applied on the divided spatial domains which are called Representative Elementary Watershed (REW). Based on the 2nd law of thermodynamics, Reggiani (1999) put forward several constitutive relations of hydrological processes. Associated with the above equations, the framework of a physically based distributed hydrological model was established. The crucial step for successfully applying this approach is to develop physically based closure relations for these terms and simplify the set of equations. The paper showed how a theoretical hydrological model based on the REW method was applied to prosecute the hydrological response simulation for a humid watershed. The established model was used to carry on the long-term (daily runoff forecasting) and short-term (runoff simulation of storm event) hydrological simulation in the studied watershed and the simulated results were analysed. These results and analysis proved that this physically based distributed hydrological model can produce satisfied simulation results and describe the hydrological responses correctly. Finally, several aspects to improve the model demonstrated by the results and analysis were put forward which would be carried out in the future.

  13. A unified approach for process-based hydrologic modeling: 1. Modeling concept

    NASA Astrophysics Data System (ADS)

    Clark, Martyn P.; Nijssen, Bart; Lundquist, Jessica D.; Kavetski, Dmitri; Rupp, David E.; Woods, Ross A.; Freer, Jim E.; Gutmann, Ethan D.; Wood, Andrew W.; Brekke, Levi D.; Arnold, Jeffrey R.; Gochis, David J.; Rasmussen, Roy M.

    2015-04-01

    This work advances a unified approach to process-based hydrologic modeling to enable controlled and systematic evaluation of multiple model representations (hypotheses) of hydrologic processes and scaling behavior. Our approach, which we term the Structure for Unifying Multiple Modeling Alternatives (SUMMA), formulates a general set of conservation equations, providing the flexibility to experiment with different spatial representations, different flux parameterizations, different model parameter values, and different time stepping schemes. In this paper, we introduce the general approach used in SUMMA, detailing the spatial organization and model simplifications, and how different representations of multiple physical processes can be combined within a single modeling framework. We discuss how SUMMA can be used to systematically pursue the method of multiple working hypotheses in hydrology. In particular, we discuss how SUMMA can help tackle major hydrologic modeling challenges, including defining the appropriate complexity of a model, selecting among competing flux parameterizations, representing spatial variability across a hierarchy of scales, identifying potential improvements in computational efficiency and numerical accuracy as part of the numerical solver, and improving understanding of the various sources of model uncertainty.

  14. Significance of hydrological model choice and land use changes when doing climate change impact assessment

    NASA Astrophysics Data System (ADS)

    Bjørnholt Karlsson, Ida; Obel Sonnenborg, Torben; Refsgaard, Jens Christian; Høgh Jensen, Karsten

    2014-05-01

    Uncertainty in impact studies arises both from Global Climate Models (GCM), emission projections, statistical downscaling, Regional Climate Models (RCM), hydrological models and calibration techniques (Refsgaard et al. 2013). Some of these uncertainties have been evaluated several times in the literature; however few studies have investigated the effect of hydrological model choice on the assessment results (Boorman & Sefton 1997; Jiang et al. 2007; Bastola et al. 2011). These studies have found that model choice results in large differences, up to 70%, in the predicted discharge changes depending on the climate input. The objective of the study is to investigate the impact of climate change on hydrology of the Odense catchment, Denmark both in response to (a) different climate projections (GCM-RCM combinations); (b) different hydrological models and (c) different land use scenarios. This includes: 1. Separation of the climate model signal; the hydrological model signal and the land use signal 2. How do the different hydrological components react under different climate and land use conditions for the different models 3. What land use scenario seems to provide the best adaptation for the challenges of the different future climate change scenarios from a hydrological perspective? Four climate models from the ENSEMBLES project (Hewitt & Griggs 2004): ECHAM5 - HIRHAM5, ECHAM5 - RCA3, ARPEGE - RM5.1 and HadCM3 - HadRM3 are used, assessing the climate change impact in three periods: 1991-2010 (present), 2041-2060 (near future) and 2081-2100 (far future). The four climate models are used in combination with three hydrological models with different conceptual layout: NAM, SWAT and MIKE SHE. Bastola, S., C. Murphy and J. Sweeney (2011). "The role of hydrological modelling uncertainties in climate change impact assessments of Irish river catchments." Advances in Water Resources 34: 562-576. Boorman, D. B. and C. E. M. Sefton (1997). "Recognising the uncertainty in the quantification of the effects of climate change on hydrological response." Climate Change 35: 415-434. Hewitt, C. D. and D. J. Griggs (2004). "Ensembles-based predictions of climate changes and their impacts." Eos, Transactions American Geophysical Union 85: 1-566. Jiang, T., Y. D. Chen, C. Xu, X. Chen, X. Chen and V. P. Singh (2007). "Comparison of hydrological impacts of climate change simulated by six hydrological models in the Dongjiang Basin, South China." Journal of hydrology 336: 316-333. Refsgaard, J. C., K. Arnbjerg-Nielsen, M. Drews, K. Halsnæs, E. Jeppesen, H. Madsen, A. Markandya, J. E. Olesen, J. R. Porter and J. H. Christensen (2013). "The role of uncertainty in climate change adaptation strategies - A Danish water management example." Mitigation and Adaptation Strategies for Global Change 18: 337-359.

  15. Downscaling Meteorological Data For Use In Hydrological Modelling

    NASA Astrophysics Data System (ADS)

    Born, K.; Gumpert, M.; Schulz, O.

    The IMPETUS Westafricaproject focusses on water availability, use and management as well as on impacts of climate variability on the water cycle in two climate risk regions: The river catchments of the Qued Drâa in Morocco and of the Ouémé in Benin. The catchment of the Drâa river in Morooco is located in the vicinity of the High Atlas Mountains. Thus, rainfall and snowmelt contribute to the water balance of this semi-arid catchment. For hydrological modelling of longer periods, distributed me- teorological data are necessary to compute surface fluxes, which actually connect soil/vegetation cover and the atmosphere. In opposite to very expensive methods of downscaling with prognostic meteorological models, a relatively simple, diagnostic model was constructed to calculate spatially distributed snow and rain fields as well as surface fluxes for larger time scales (days to months). The model physics are described in some detail. A first insight into the performance of the model is given by comparison with observational data of a small climatic station network in the region of interest.

  16. Hydrologic modeling to screen potential environmental management methods for malaria vector control in Niger

    Microsoft Academic Search

    Rebecca L. Gianotti; Arne Bomblies; Elfatih A. B. Eltahir

    2009-01-01

    This paper describes the first use of Hydrology-Entomology and Malaria Transmission Simulator (HYDREMATS), a physically based distributed hydrology model, to investigate environmental management methods for malaria vector control in the Sahelian village of Banizoumbou, Niger. The investigation showed that leveling of topographic depressions where temporary breeding habitats form during the rainy season, by altering pool basin microtopography, could reduce the

  17. The Effect of Modeling and Visualization Resources on Student Understanding of Physical Hydrology

    ERIC Educational Resources Information Center

    Marshall, Jilll A.; Castillo, Adam J.; Cardenas, M. Bayani

    2015-01-01

    We investigated the effect of modeling and visualization resources on upper-division, undergraduate and graduate students' performance on an open-ended assessment of their understanding of physical hydrology. The students were enrolled in one of five sections of a physical hydrology course. In two of the sections, students completed homework…

  18. Evaluation of ensemble-based distributed hydrologic model response with disaggregated precipitation products

    Microsoft Academic Search

    Barton A. Forman; Enrique R. Vivoni; Steven A. Margulis

    2008-01-01

    The disaggregation of coarse precipitation products is desirable for spatially distributed hydrological applications where high-resolution rainfall fields are required. In this study, we generate an ensemble of satellite-based precipitation estimates using a spatiotemporal disaggregation framework for use in a spatially explicit hydrologic model. The framework effectively reproduced small, localized storm events using coarse precipitation estimates while simultaneously including known error

  19. The implementation and validation of improved land-surface hydrology in an atmospheric general circulation model

    Microsoft Academic Search

    Kevin D. Johnson; Dara Entekhabi; Peter S. Eagleson

    1993-01-01

    New land-surface hydrologic parameterizations are implemented into the NASA Goddard Institute for Space Studies (GISS) General Circulation Model (GCM). These parameterizations are: (1) runoff and evapotranspiration functions that include the effects of subgrid-scale spatial variability and use physically based equations of hydrologic flux at the soil surface and (2) a realistic soil moisture diffusion scheme for the movement of water

  20. The application of remote sensing to the development and formulation of hydrologic planning models: Executive summary

    NASA Technical Reports Server (NTRS)

    Castruccio, P. A.; Loats, H. L., Jr.; Fowler, T. R.

    1977-01-01

    Methods for the reduction of remotely sensed data and its application in hydrologic land use assessment, surface water inventory, and soil property studies are presented. LANDSAT data is used to provide quantitative parameters and coefficients to construct watershed transfer functions for a hydrologic planning model aimed at estimating peak outflow from rainfall inputs.

  1. Observation and modeling of catchment-scale solute transport in the hydrologic response: A tracer study

    Microsoft Academic Search

    G. Botter; F. Peratoner; M. Putti; A. Zuliani; R. Zonta; A. Rinaldo; M. Marani

    2008-01-01

    The coherent description of water flow and solute transport within heterogeneous hydrologic media (e.g., hillslopes or entire catchments) in response to external rainfall forcings represents a challenge in hydrological modeling. In this paper the mechanisms determining the mobilization and transport of solutes in soils through the paths of runoff formation are investigated by means of a tracer experiment conducted within

  2. Operational Hydrologic Simulation Modeling at the Natural Resources Conservation Service's National Water and Climate Center

    Microsoft Academic Search

    Thomas Pagano; Tom Perkins; Jennifer Erxleben

    This paper describes the current status and anticipated near-term future directions of the U.S. Department of Agriculture's Natural Resources Conservation Service's (NRCS) National Water and Climate Center with respect to the use of hydrologic simulation models. It begins with a description of the water supply forecasting operations, and continues with a review of past attempts to adopt operational hydrologic simulation

  3. A New Global River Network Database for Macroscale Hydrologic modeling

    SciTech Connect

    Wu, Huan; Kimball, John S.; Li, Hongyi; Huang, Maoyi; Leung, Lai-Yung R.; Adler, Robert F.

    2012-09-28

    Coarse resolution (upscaled) river networks are critical inputs for runoff routing in macroscale hydrologic models. Recently, Wu et al. (2011) developed a hierarchical Dominant River Tracing (DRT) algorithm for automated extraction and spatial upscaling of basin flow directions and river networks using fine-scale hydrography inputs (e.g., flow direction, river networks, and flow accumulation). The DRT was initially applied using HYDRO1K baseline fine-scale hydrography inputs and the resulting upscaled global hydrography maps were produced at several spatial scales, and verified against other available regional and global datasets. New baseline fine-scale hydrography data from HydroSHEDS are now available for many regions and provide superior scale and quality relative to HYDRO1K. However, HydroSHEDS does not cover regions above 60°N. In this study, we applied the DRT algorithms using combined HydroSHEDS and HYDRO1K global fine-scale hydrography inputs, and produced a new series of upscaled global river network data at multiple (1/16° to 2°) spatial resolutions in a consistent (WGS84) projection. The new upscaled river networks are internally consistent and congruent with the baseline fine-scale inputs. The DRT results preserve baseline fine-scale river networks independent of spatial scales, with consistency in river network, basin shape, basin area, river length, and basin internal drainage structure between upscaled and baseline fine-scale hydrography. These digital data are available online for public access (ftp://ftp.ntsg.umt.edu/pub/data/DRT/) and should facilitate improved regional to global scale hydrological simulations, including runoff routing and river discharge calculations.

  4. Soil hydrologic characterization for modeling large scale soil remediation protocols

    NASA Astrophysics Data System (ADS)

    Romano, Nunzio; Palladino, Mario; Di Fiore, Paola; Sica, Benedetto; Speranza, Giuseppe

    2014-05-01

    In Campania Region (Italy), the Ministry of Environment identified a National Interest Priority Sites (NIPS) with a surface of about 200,000 ha, characterized by different levels and sources of pollution. This area, called Litorale Domitio-Agro Aversano includes some polluted agricultural land, belonging to more than 61 municipalities in the Naples and Caserta provinces. In this area, a high level spotted soil contamination is moreover due to the legal and outlaw industrial and municipal wastes dumping, with hazardous consequences also on the quality of the water table. The EU-Life+ project ECOREMED (Implementation of eco-compatible protocols for agricultural soil remediation in Litorale Domizio-Agro Aversano NIPS) has the major aim of defining an operating protocol for agriculture-based bioremediation of contaminated agricultural soils, also including the use of crops extracting pollutants to be used as biomasses for renewable energy production. In the framework of this project, soil hydrologic characterization plays a key role and modeling water flow and solute transport has two main challenging points on which we focus on. A first question is related to the fate of contaminants infiltrated from stormwater runoff and the potential for groundwater contamination. Another question is the quantification of fluxes and spatial extent of root water uptake by the plant species employed to extract pollutants in the uppermost soil horizons. Given the high variability of spatial distribution of pollutants, we use soil characterization at different scales, from field scale when facing root water uptake process, to regional scale when simulating interaction between soil hydrology and groundwater fluxes.

  5. HBV Genotype B/C and Response to Lamivudine Therapy: A Systematic Review

    PubMed Central

    Chen, Xiu-Li; Zhang, Xiao-Lan

    2013-01-01

    A number of nucleoside analogues such as lamivudine (LAM), actually used for the treatment of chronic hepatitis B, can suppress HBV DNA replication, improve transaminase level and liver histology, and enhance the rate of hepatitis B e antigen (HBeAg) clearance. The responses to LAM therapy involve HBeAg clearance and HBV DNA conversion of negative. However, the associations between HBV genotype B/C and response to LAM therapy remain ambiguous. The aim of this meta-analysis is to determine more precise estimations of the relationship. All the publications on the associations between HBV genotype B/C and response to LAM (HBeAg clearance and HBV DNA conversion of negative) through June 2013 were collected. Relative risk (RR) with 95% confidence intervals (95% CI) was calculated in fixed or random model, I2 was calculated to examine heterogeneity, and funnel plots were plotted to examine small study effects with Stata 11 software. Overall, for HBeAg clearance and genotype B/C, the RR (95% CI) was 1.27 (0.94–1.71), while for HBV DNA conversion of negative and genotype B/C, the RR (95% CI) was 1.07 (0.98–1.17). HBV genotype B/C shows no significance associations with response to lamivudine therapy (HBeAg clearance and HBV DNA conversion of negative). PMID:24364035

  6. Influences of Soil Dataset Resolution on Hydrologic Modeling

    NASA Astrophysics Data System (ADS)

    Peschel, Joshua M.; Haan, Patricia K.; Lacey, Ronald E.

    2006-10-01

    Soils represent a fundamental abiotic parameter in defining the characteristics of an ecosystem. The U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) produces the most detailed digital spatial soil datasets that are publicly available. The Soil Survey Geographic (SSURGO) database contains basic attributes for the continuous coverage of soils across the United States. In its standard format, the SSURGO database is incompatible for use within the ArcView Soil and Water Assessment Tool (SWAT). A modified version of the State Soil and Geographic (STATSGO) database is the template soils dataset used by ArcView SWAT. This paper presents the methodology and development of a SSURGO database preprocessor extension for the ArcView SWAT model. A case study for the Upper Sabinal River Watershed near Uvalde, Texas, is given. Results indicate that hydrologic output parameter differences occur when comparing the STATSGO and SSURGO database information in the ArcView SWAT model under identical modeling conditions. Specifically, the SSURGO model produced a greater daily mean water yield with evapotranspiration and surface runoff being found consistently lower across the watershed. The most likely causes assigned to this phenomenon were higher percolation and resulting ground water return flow values due to significantly larger saturated hydraulic conductivity values associated with the SSURGO 2.x database.

  7. PREDICTIVE UNCERTAINTY IN HYDROLOGIC AND WATER QUALITY MODELING: APPROACHES, APPLICATION TO ENVIRONMENTAL MANAGEMENT, AND FUTURE CHALLENGES

    EPA Science Inventory

    Extant process-based hydrologic and water quality models are indispensable to water resources planning and environmental management. However, models are only approximations of real systems and often calibrated with incomplete and uncertain data. Reliable estimates, or perhaps f...

  8. Accesible hydrological monitoring for better decision making and modelling: a regional initiative in the Andes

    NASA Astrophysics Data System (ADS)

    De Bievre, B.; Célleri, R.; Crespo, P.; Ochoa, B.; Buytaert, W.; Tobón, C.; Villacís, M.; Villazon, M. F.; Llerena, C.; Rodriguez, M.; Viñas, P.

    2013-05-01

    The goal of the Hydrological Monitoring of Andean Ecosystems Initiative is to improve the conservation and management of High-Andean ecosystems by providing information on the hydrological response of these ecosystems and how different land-uses affect their water yield and regulation capacity. The initiative fills a gap left by widespread hydrological modeling exercises that suffer from lack of data, and by glacier monitoring under climate change. The initiative proposes a hydrological monitoring system involving precipitation, discharge and land cover monitoring in paired catchments. The methodology is accessible for non-specialist organizations, and allows for generation of evidence of land use impact on hydrology on the short term (i.e. a few years). Nevertheless, long term monitoring is pursued with the aim of identifying trends in hydrological response (as opposed to trends in climate) under global change. In this way it supports decision making on the preservation of the hydrological services of the catchment. The initiative aims at a high number of paired catchment sites along the Andes, in order to draw regional conclusions and capture variability, and is connected to more detailed hydrological research sites of several Andean universities. We present preliminary results of a dozen of sites from Venezuela to Bolivia, summarized in hydrological performance indicators that were agreed upon among hydrologists, local stakeholders, and water authorities. The success factors, as well as limitations, of the network are discussed.

  9. Niger River Basin - Hydrological Modeling: Inter-changeability of parameters between models versions

    NASA Astrophysics Data System (ADS)

    KONE, S.

    2013-12-01

    An enhanced hydrological framework from the existing conceptual model GR2M leads to significant results in inter-changing the models parameters, using the parameters obtained during the calibration process of a first model version in the validation process of a second model version. A two parameters and three input variables' conceptual framework called SimulHyd is used to simulate the runoff of sixteen watersheds on the Niger River and its tributaries, over eighteen years to forty six years. The first parameter controls the three model input variables and the second controls its output runoff information. Between either a lumped version and a semi-distributed version or the GR2M model and SimulHyd model, a set of three significant models parameters inter-changeability are detected: SimulHyd is better in validation process after 1970 using the calibrated parameters from GR2M before 1970, in forward modeling; GR2M is better in validation process before 1970 using the calibrated parameters from SimulHyd after 1970; and in some cases the models are more efficient in validation than in calibration. The combination both of two hydrological models drifting one of the other and of two concepts of modeling are used to demonstrate a success in the synergy of four models versions to simulate more accurately the behaviors of hydrological systems. This particularity (of these models version), responding positively in models parameters importing and exporting between different models versions, can be explored in the context of the assessment of climate change impact on water resources.INTER-CHANGED PARAMETERS NON-DISTRIBUTED MODELING VS SEMI-DISTRIBUTED MODELING SimulHyd (Simulation of hydrological Systems)N-D : Non-Distributed modelingS-D : Semi-Distributed modeling

  10. Hydrological improvements for nutrient and pollutant emission modeling in large scale catchments

    NASA Astrophysics Data System (ADS)

    Höllering, S.; Ihringer, J.

    2012-04-01

    An estimation of emissions and loads of nutrients and pollutants into European water bodies with as much accuracy as possible depends largely on the knowledge about the spatially and temporally distributed hydrological runoff patterns. An improved hydrological water balance model for the pollutant emission model MoRE (Modeling of Regionalized Emissions) (IWG, 2011) has been introduced, that can form an adequate basis to simulate discharge in a hydrologically differentiated, land-use based way to subsequently provide the required distributed discharge components. First of all the hydrological model had to comply both with requirements of space and time in order to calculate sufficiently precise the water balance on the catchment scale spatially distributed in sub-catchments and with a higher temporal resolution. Aiming to reproduce seasonal dynamics and the characteristic hydrological regimes of river catchments a daily (instead of a yearly) time increment was applied allowing for a more process oriented simulation of discharge dynamics, volume and therefore water balance. The enhancement of the hydrological model became also necessary to potentially account for the hydrological functioning of catchments in regard to scenarios of e.g. a changing climate or alterations of land use. As a deterministic, partly physically based, conceptual hydrological watershed and water balance model the Precipitation Runoff Modeling System (PRMS) (USGS, 2009) was selected to improve the hydrological input for MoRE. In PRMS the spatial discretization is implemented with sub-catchments and so called hydrologic response units (HRUs) which are the hydrotropic, distributed, finite modeling entities each having a homogeneous runoff reaction due to hydro-meteorological events. Spatial structures and heterogeneities in sub-catchments e.g. urbanity, land use and soil types were identified to derive hydrological similarities and classify in different urban and rural HRUs. In this way the hydrological system is simulated spatially differentiated and emissions from urban and rural areas into river courses can be detected separately. In the Ruhr catchment (4.485 km2) as a right tributary of the Rhine located in the lower mountain range of North Rhine-Westphalia in Germany for the validation period 2002-2006 the hydrological model showed first satisfying results. The feasibility study in the Ruhr shows the suitability of the approach and illustrates the potentials for further developments in terms of an implementation throughout the German and contiguous watersheds. IWG, Karlsruhe Institute of Technology (KIT). 2011. http://isww.iwg.kit.edu/MoRE.php. [Online] Institute for Water and River Basin Management, Department of Aquatic Environmental Engineering, October 2011. USGS, U.S. Geological Survey. 2009. PRMS-2009, the Precipitation-Runoff Modeling System. Denver, Colorado : s.n., 2009. Bd. U.S. Geologic Survey Open File Report.

  11. Simulation of flood reduction by natural river rehabilitation using a distributed hydrological model Hydrology and Earth System Sciences, 8(6), 11291140 (2004) EGU

    E-print Network

    Boyer, Edmond

    2004-01-01

    Simulation of flood reduction by natural river rehabilitation using a distributed hydrological model 1129 Hydrology and Earth System Sciences, 8(6), 11291140 (2004) © EGU Simulation of flood, Grand-Duchy of Luxembourg, are discussed; the rehabilitation measures include planting and changing

  12. Epidemiology of HBV subgenotypes D.

    PubMed

    Ozaras, Resat; Inanc Balkan, Ilker; Yemisen, Mucahit; Tabak, Fehmi

    2015-02-01

    The natural history of hepatitis B virus infection is not uniform and affected from several factors including, HBV genotype. Genotype D is a widely distributed genotype. Among genotype D, several subgenotypes differentiate epidemiologically and probably clinically. D1 is predominant in Middle East and North Africa, and characterized by early HBeAg seroconversion and low viral load. D2 is seen in Albania, Turkey, Brazil, western India, Lebanon, and Serbia. D3 was reported from Serbia, western India, and Indonesia. It is a predominant subgenotype in injection drug use-related acute HBV infections in Europe and Canada. D4 is relatively rare and reported from Haiti, Russia and Baltic region, Brazil, Kenya, Morocco and Rwanda. Subgenotype D5 seems to be common in Eastern India. D6 has been reported as a rare subgenotype from Indonesia, Kenya, Russia and Baltic region. D7 is the main genotype in Morocco and Tunisia. D8 and D9 are recently described subgenotypes and reported from Niger and India, respectively. Subgenotypes of genotype D may have clinical and/or viral differences. More subgenotype studies are required to conclude on subgenotype and its clinical/viral characteristics. PMID:25037178

  13. The Impact of Microwave-Derived Surface Soil Moisture on Watershed Hydrological Modeling

    NASA Technical Reports Server (NTRS)

    ONeill, P. E.; Hsu, A. Y.; Jackson, T. J.; Wood, E. F.; Zion, M.

    1997-01-01

    The usefulness of incorporating microwave-derived soil moisture information in a semi-distributed hydrological model was demonstrated for the Washita '92 experiment in the Little Washita River watershed in Oklahoma. Initializing the hydrological model with surface soil moisture fields from the ESTAR airborne L-band microwave radiometer on a single wet day at the start of the study period produced more accurate model predictions of soil moisture than a standard hydrological initialization with streamflow data over an eight-day soil moisture drydown.

  14. Test and Sensitivity Analysis of Hydrological Modeling in the Coupled WRF-Urban Modeling System

    NASA Astrophysics Data System (ADS)

    Wang, Z.; yang, J.

    2013-12-01

    Rapid urbanization has emerged as the source of many adverse effects that challenge the environmental sustainability of cities under changing climatic patterns. One essential key to address these challenges is to physically resolve the dynamics of urban-land-atmospheric interactions. To investigate the impact of urbanization on regional climate, physically-based single layer urban canopy model (SLUCM) has been developed and implemented into the Weather Research and Forecasting (WRF) platform. However, due to the lack of realistic representation of urban hydrological processes, simulation of urban climatology by current coupled WRF-SLUCM is inevitably inadequate. Aiming at improving the accuracy of simulations, recently we implemented urban hydrological processes into the model, including (1) anthropogenic latent heat, (2) urban irrigation, (3) evaporation over impervious surface, and (4) urban oasis effect. In addition, we couple the green roof system into the model to verify its capacity in alleviating urban heat island effect at regional scale. Driven by different meteorological forcings, offline tests show that the enhanced model is more accurate in predicting turbulent fluxes arising from built terrains. Though the coupled WRF-SLUCM has been extensively tested against various field measurement datasets, accurate input parameter space needs to be specified for good model performance. As realistic measurements of all input parameters to the modeling framework are rarely possible, understanding the model sensitivity to individual parameters is essential to determine the relative importance of parameter uncertainty to model performance. Thus we further use an advanced Monte Carlo approach to quantify relative sensitivity of input parameters of the hydrological model. In particular, performance of two widely used soil hydraulic models, namely the van Genuchten model (based on generic soil physics) and an empirical model (viz. the CHC model currently adopted in WRF-SLUCM) is investigated. Results show that the CHC model requires a much finer time step for numerical stability in hydrological modeling and thus is more computationally expensive in the coupled WRF-SLUCM modeling environment.

  15. Statistical procedures for evaluating daily and monthly hydrologic model predictions

    USGS Publications Warehouse

    Coffey, M.E.; Workman, S.R.; Taraba, J.L.; Fogle, A.W.

    2004-01-01

    The overall study objective was to evaluate the applicability of different qualitative and quantitative methods for comparing daily and monthly SWAT computer model hydrologic streamflow predictions to observed data, and to recommend statistical methods for use in future model evaluations. Statistical methods were tested using daily streamflows and monthly equivalent runoff depths. The statistical techniques included linear regression, Nash-Sutcliffe efficiency, nonparametric tests, t-test, objective functions, autocorrelation, and cross-correlation. None of the methods specifically applied to the non-normal distribution and dependence between data points for the daily predicted and observed data. Of the tested methods, median objective functions, sign test, autocorrelation, and cross-correlation were most applicable for the daily data. The robust coefficient of determination (CD*) and robust modeling efficiency (EF*) objective functions were the preferred methods for daily model results due to the ease of comparing these values with a fixed ideal reference value of one. Predicted and observed monthly totals were more normally distributed, and there was less dependence between individual monthly totals than was observed for the corresponding predicted and observed daily values. More statistical methods were available for comparing SWAT model-predicted and observed monthly totals. The 1995 monthly SWAT model predictions and observed data had a regression Rr2 of 0.70, a Nash-Sutcliffe efficiency of 0.41, and the t-test failed to reject the equal data means hypothesis. The Nash-Sutcliffe coefficient and the R r2 coefficient were the preferred methods for monthly results due to the ability to compare these coefficients to a set ideal value of one.

  16. An Open Source modular platform for hydrological model implementation

    NASA Astrophysics Data System (ADS)

    Kolberg, Sjur; Bruland, Oddbjørn

    2010-05-01

    An implementation framework for setup and evaluation of spatio-temporal models is developed, forming a highly modularized distributed model system. The ENKI framework allows building space-time models for hydrological or other environmental purposes, from a suite of separately compiled subroutine modules. The approach makes it easy for students, researchers and other model developers to implement, exchange, and test single routines in a fixed framework. The open-source license and modular design of ENKI will also facilitate rapid dissemination of new methods to institutions engaged in operational hydropower forecasting or other water resource management. Written in C++, ENKI uses a plug-in structure to build a complete model from separately compiled subroutine implementations. These modules contain very little code apart from the core process simulation, and are compiled as dynamic-link libraries (dll). A narrow interface allows the main executable to recognise the number and type of the different variables in each routine. The framework then exposes these variables to the user within the proper context, ensuring that time series exist for input variables, initialisation for states, GIS data sets for static map data, manually or automatically calibrated values for parameters etc. ENKI is designed to meet three different levels of involvement in model construction: • Model application: Running and evaluating a given model. Regional calibration against arbitrary data using a rich suite of objective functions, including likelihood and Bayesian estimation. Uncertainty analysis directed towards input or parameter uncertainty. o Need not: Know the model's composition of subroutines, or the internal variables in the model, or the creation of method modules. • Model analysis: Link together different process methods, including parallel setup of alternative methods for solving the same task. Investigate the effect of different spatial discretization schemes. o Need not: Write or compile computer code, handle file IO for each modules, • Routine implementation and testing. Implementation of new process-simulating methods/equations, specialised objective functions or quality control routines, testing of these in an existing framework. o Need not: Implement user or model interface for the new routine, IO handling, administration of model setup and run, calibration and validation routines etc. From being developed for Norway's largest hydropower producer Statkraft, ENKI is now being turned into an Open Source project. At the time of writing, the licence and the project administration is not established. Also, it remains to port the application to other compilers and computer platforms. However, we hope that ENKI will prove useful for both academic and operational users.

  17. Convective rain cell modelling from radar data and their linking with a hydrological model

    NASA Astrophysics Data System (ADS)

    Morin, E.; Yakir, H.

    2009-04-01

    The technology of weather radar systems enables a detailed view of rainstorms over watersheds with high spatial and temporal resolution that was never available before. Nevertheless, the utilization of radar rainfall data in hydrological models has not brought a significant improvement in understanding rainfall-runoff processes, and in prediction capability of watershed responses. There is a need to develop new ways to exploit essential information about spatio-temporal rain structures, and gain greater insights into rainfall and subsequent watershed response behavior. The current study suggests an innovative approach to the above challenge. We emphasize as a key issue the structure in which the data are represented in the hydrological models. Whereas in the standard approach, radar data are utilized in a grid structure, we propose to represent the rainfall data in a model-structure that takes into account the known behavior and properties of the rain system. The spatial and temporal characteristics of the rain system are thus explicitly represented and are linked directly to hydrological responses. The basic distinction between the grid and the currently suggested data model-structures is the presence of a-priori knowledge about the represented system incorporated into the model. The above approach was applied in the analysis of a large flood event in a semi-arid catchment in southern Israel. A model representing the spatio-temporal structure of the derived rain cells was developed and fitted to the radar data. The hydrological model was then fed by the rain cell information rather than the gridded radar data. Using this direct linkage between rain cell features and hydrological features the main controls of the generated flood were determined.

  18. Development and test of a spatially distributed hydrological\\/water quality model for mesoscale watersheds

    Microsoft Academic Search

    Valentina Krysanova; Dirk-Ingmar Müller-Wohlfeil; Alfred Becker

    1998-01-01

    The new watershed model SWIM was developed in order to provide a comprehensive GIS-based tool for hydrological and water quality modelling in mesoscale watersheds (from 100 to 10?000 km2), which can be parametrized using regionally available information. SWIM is based on two previously developed tools—SWAT and MATSALU. The model integrates hydrology, vegetation, erosion and nitrogen dynamics at the watershed scale.

  19. Calibration of the Hydrological Simulation Program Fortran (HSPF) model using automatic calibration and geographical information systems

    Microsoft Academic Search

    N. A. Al-Abed; H. R. Whiteley

    2002-01-01

    Calibrating a comprehensive, multi-parameter conceptual hydrological model, such as the Hydrological Simulation Program Fortran model, is a major challenge. This paper describes calibration procedures for water-quantity parameters of the HSPF version 10·11 using the automatic-calibration parameter estimator model coupled with a geographical information system (GIS) approach for spatially averaged properties. The study area was the Grand River watershed, located in

  20. Modeling of Thermal-Hydrological-Chemical Laboratory Experiments

    SciTech Connect

    P. F. Dobson; T. J. Kneafsey; E. L. Sonnenthal; Nicolas Spycher

    2001-05-31

    The emplacement of heat-generating nuclear waste in the potential geologic repository at Yucca Mountain, Nevada, will result in enhanced water-rock interaction around the emplacement drifts. Water present in the matrix and fractures of the rock around the drift may vaporize and migrate via fractures to cooler regions where condensation would occur. The condensate would react with the surrounding rock, resulting in mineral dissolution. Mineralized water flowing under gravity back towards the heat zone would boil, depositing the dissolved minerals. Such mineral deposition would reduce porosity and permeability above the repository, thus altering the flow paths of percolating water. The objective of this research is to use coupled thermal-hydrological-chemical (THC) models to simulate previously conducted laboratory experiments involving tuff dissolution and mineral precipitation in a boiling, unsaturated fracture. Numerical simulations of tuff dissolution and fracture plugging were performed using a modified version of the TOUGHREACT code developed at LBNL by T. Xu and K. Pruess. The models consider the transport of heat, water, gas and dissolved constituents, reactions between gas, mineral and aqueous phases, and the coupling of porosity and permeability to mineral dissolution and precipitation. The model dimensions and initial fluid chemistry, rock mineralogy, permeability, and porosity were defined using the experimental conditions. A 1-D plug-flow model was used to simulate dissolution resulting from reaction between deionized water and crushed ash flow tuff. A 2-D model was developed to simulate the flow of mineralized water through a planar fracture within a block of ash flow tuff where boiling conditions led to mineral precipitation. Matrix blocks were assigned zero permeability to confine fluid flow to the fracture, and permeability changes in the fracture were specified using the porosity cubic law relationship.

  1. Review of soil water models with respect to savanna hydrology 

    E-print Network

    Derry, Julian F; Russell, Graham; Liedloff, Adam C

    2006-07-21

    Effective management leading towards sustainable rangeland production in arid and semi-arid regions will stem from effective soil water management and comprehension of the hydrological properties of the soil in relation ...

  2. On the Hydrologic Adjustment of Climate-Model Projections: The Potential Pitfall of Potential Evapotranspiration

    USGS Publications Warehouse

    Milly, Paul C.; Dunne, Krista A.

    2011-01-01

    Hydrologic models often are applied to adjust projections of hydroclimatic change that come from climate models. Such adjustment includes climate-bias correction, spatial refinement ("downscaling"), and consideration of the roles of hydrologic processes that were neglected in the climate model. Described herein is a quantitative analysis of the effects of hydrologic adjustment on the projections of runoff change associated with projected twenty-first-century climate change. In a case study including three climate models and 10 river basins in the contiguous United States, the authors find that relative (i.e., fractional or percentage) runoff change computed with hydrologic adjustment more often than not was less positive (or, equivalently, more negative) than what was projected by the climate models. The dominant contributor to this decrease in runoff was a ubiquitous change in runoff (median -11%) caused by the hydrologic model’s apparent amplification of the climate-model-implied growth in potential evapotranspiration. Analysis suggests that the hydrologic model, on the basis of the empirical, temperature-based modified Jensen–Haise formula, calculates a change in potential evapotranspiration that is typically 3 times the change implied by the climate models, which explicitly track surface energy budgets. In comparison with the amplification of potential evapotranspiration, central tendencies of other contributions from hydrologic adjustment (spatial refinement, climate-bias adjustment, and process refinement) were relatively small. The authors’ findings highlight the need for caution when projecting changes in potential evapotranspiration for use in hydrologic models or drought indices to evaluate climate-change impacts on water.

  3. Towards ecosystem accounting: a comprehensive approach to modelling multiple hydrological ecosystem services

    NASA Astrophysics Data System (ADS)

    Duku, C.; Rathjens, H.; Zwart, S. J.; Hein, L.

    2015-03-01

    Ecosystem accounting is an emerging field that aims to provide a consistent approach to analysing environment-economy interactions. In spite of the progress made in mapping and quantifying hydrological ecosystem services, several key issues must be addressed if ecohydrological modelling approaches are to be aligned with ecosystem accounting. They include modelling hydrological ecosystem services with adequate spatiotemporal detail and accuracy at aggregated scales to support ecosystem accounting, distinguishing between service capacity and service flow, and linking ecohydrological processes to the supply of dependent hydrological ecosystem services. We present a spatially explicit approach, which is consistent with ecosystem accounting, for mapping and quantifying service capacity and service flow of multiple hydrological ecosystem services. A grid-based setup of a modified Soil Water and Assessment Tool (SWAT), SWAT Landscape, is first used to simulate the watershed ecohydrology. Model outputs are then post-processed to map and quantify hydrological ecosystem services and to set up biophysical ecosystem accounts. Trend analysis statistical tests are conducted on service capacity accounts to track changes in the potential to provide service flows. Ecohydrological modelling to support ecosystem accounting requires appropriate decisions regarding model process inclusion, physical and mathematical representation, spatial heterogeneity, temporal resolution, and model accuracy. We demonstrate this approach in the Upper Ouémé watershed in Benin. Our analyses show that integrating hydrological ecosystem services in an ecosystem accounting framework provides relevant information on ecosystems and hydrological ecosystem services at appropriate scales suitable for decision-making. Our analyses further identify priority areas important for maintaining hydrological ecosystem services as well as trends in hydrological ecosystem services supply over time.

  4. Modeling Feedbacks Between Individual Human Decisions and Hydrology Using Interconnected Physical and Social Models

    NASA Astrophysics Data System (ADS)

    Murphy, J.; Lammers, R. B.; Proussevitch, A. A.; Ozik, J.; Altaweel, M.; Collier, N. T.; Alessa, L.; Kliskey, A. D.

    2014-12-01

    The global hydrological cycle intersects with human decision making at multiple scales, from dams and irrigation works to the taps in individuals' homes. Residential water consumers are commonly encouraged to conserve; these messages are heard against a background of individual values and conceptions about water quality, uses, and availability. The degree to which these values impact the larger-hydrological dynamics, the way that changes in those values have impacts on the hydrological cycle through time, and the feedbacks by which water availability and quality in turn shape those values, are not well explored. To investigate this domain we employ a global-scale water balance model (WBM) coupled with a social-science-grounded agent-based model (ABM). The integration of a hydrological model with an agent-based model allows us to explore driving factors in the dynamics in coupled human-natural systems. From the perspective of the physical hydrologist, the ABM offers a richer means of incorporating the human decisions that drive the hydrological system; from the view of the social scientist, a physically-based hydrological model allows the decisions of the agents to play out against constraints faithful to the real world. We apply the interconnected models to a study of Tucson, Arizona, USA, and its role in the larger Colorado River system. Our core concept is Technology-Induced Environmental Distancing (TIED), which posits that layers of technology can insulate consumers from direct knowledge of a resource. In Tucson, multiple infrastructure and institutional layers have arguably increased the conceptual distance between individuals and their water supply, offering a test case of the TIED framework. Our coupled simulation allows us to show how the larger system transforms a resource with high temporal and spatial variability into a consumer constant, and the effects of this transformation on the regional system. We use this to explore how pricing, messaging, and social dynamics impact demand, how changes in demand affect the regional water system, and under what system challenges the values of the individuals are likely to change. This study is a preamble to modeling multiple regionally connected cities and larger systems with impacts on hydrology at the continental and global scales.

  5. Rapid Prototyping of Hydrologic Model Interfaces with IPython

    NASA Astrophysics Data System (ADS)

    Farthing, M. W.; Winters, K. D.; Ahmadia, A. J.; Hesser, T.; Howington, S. E.; Johnson, B. D.; Tate, J.; Kees, C. E.

    2014-12-01

    A significant gulf still exists between the state of practice and state of the art in hydrologic modeling. Part of this gulf is due to the lack of adequate pre- and post-processing tools for newly developed computational models. The development of user interfaces has traditionally lagged several years behind the development of a particular computational model or suite of models. As a result, models with mature interfaces often lack key advancements in model formulation, solution methods, and/or software design and technology. Part of the problem has been a focus on developing monolithic tools to provide comprehensive interfaces for the entire suite of model capabilities. Such efforts require expertise in software libraries and frameworks for creating user interfaces (e.g., Tcl/Tk, Qt, and MFC). These tools are complex and require significant investment in project resources (time and/or money) to use. Moreover, providing the required features for the entire range of possible applications and analyses creates a cumbersome interface. For a particular site or application, the modeling requirements may be simplified or at least narrowed, which can greatly reduce the number and complexity of options that need to be accessible to the user. However, monolithic tools usually are not adept at dynamically exposing specific workflows. Our approach is to deliver highly tailored interfaces to users. These interfaces may be site and/or process specific. As a result, we end up with many, customized interfaces rather than a single, general-use tool. For this approach to be successful, it must be efficient to create these tailored interfaces. We need technology for creating quality user interfaces that is accessible and has a low barrier for integration into model development efforts. Here, we present efforts to leverage IPython notebooks as tools for rapid prototyping of site and application-specific user interfaces. We provide specific examples from applications in near-shore environments as well as levee analysis. We discuss our design decisions and methodology for developing customized interfaces, strategies for delivery of the interfaces to users in various computing environments, as well as implications for the design/implementation of simulation models.

  6. On the hydrologic adjustment of climate-model projections: The potential pitfall of potential evapotranspiration

    USGS Publications Warehouse

    Milly, P.C.D.; Dunne, K.A.

    2011-01-01

    Hydrologic models often are applied to adjust projections of hydroclimatic change that come from climate models. Such adjustment includes climate-bias correction, spatial refinement ("downscaling"), and consideration of the roles of hydrologic processes that were neglected in the climate model. Described herein is a quantitative analysis of the effects of hydrologic adjustment on the projections of runoff change associated with projected twenty-first-century climate change. In a case study including three climate models and 10 river basins in the contiguous United States, the authors find that relative (i.e., fractional or percentage) runoff change computed with hydrologic adjustment more often than not was less positive (or, equivalently, more negative) than what was projected by the climate models. The dominant contributor to this decrease in runoff was a ubiquitous change in runoff (median 211%) caused by the hydrologic model's apparent amplification of the climate-model-implied growth in potential evapotranspiration. Analysis suggests that the hydrologic model, on the basis of the empirical, temperature-based modified Jensen-Haise formula, calculates a change in potential evapotranspiration that is typically 3 times the change implied by the climate models, which explicitly track surface energy budgets. In comparison with the amplification of potential evapotranspiration, central tendencies of other contributions from hydrologic adjustment (spatial refinement, climate-bias adjustment, and process refinement) were relatively small. The authors' findings highlight the need for caution when projecting changes in potential evapotranspiration for use in hydrologic models or drought indices to evaluate climatechange impacts on water. Copyright ?? 2011, Paper 15-001; 35,952 words, 3 Figures, 0 Animations, 1 Tables.

  7. Assessing simulation uncertainty of hydrological models using stochastic geological models generated with air borne geophysical data

    NASA Astrophysics Data System (ADS)

    He, Xin; Refsgaard, Jens Christian; Joergensen, Flemming; Schamper, Cyril

    2013-04-01

    Uncertainty in hydrological simulations can be originated from various sources such as observational uncertainty of input data, model structural uncertainty, model parameter uncertainty, and/or local scale heterogeneity. The model structural uncertainty is essential since it accounts for the majority of the uncertainty during model conceptualization, and it becomes the dominating factor in the overall simulation uncertainty when the subject being simulated is an indirect extrapolation from the model calibration. In the present study, we assess the simulation uncertainty of coupled surface water - groundwater models by using multiple geological models that are generated stochastically. The study area is the Norsminde catchment located in eastern Jutland, Denmark, where the complex terrain and heterogeneous geological structure makes it an ideal example to showcase the scientific challenge described above. To establish the geological model, it is first delineated with dominant geological elements by an experienced geologist using all available field data. Subsequently the internal heterogeneity within the large scale geological elements is introduced by using TProGS realizations, which are generated based on information from both borehole data and airborne geophysical data (SkyTEM). Due to the high spatial resolution and exhaustiveness, the SkyTEM data is used in two ways. First it is used to estimate the horizontal transition probability, and afterwards used as information for soft conditioning in stochastic simulations with TProGS. 10 hydrological models are developed using MIKE SHE code, to which the individual geological models are associated. The hydrological models are inversely calibrated against groundwater head and stream discharge data using PEST optimization tool. Finally the simulated flows from the 10 models are collected and presented as an ensemble in order to assess the hydrological simulation uncertainty.

  8. Integration of models for better quantification of urban hydrology: Coupling urban drainage system models and distributed groundwater models

    NASA Astrophysics Data System (ADS)

    Kidmose, J.; Troldborg, L.; Refsgaard, J.; Randall, M. T.

    2012-12-01

    There is a growing need to simulate and predict hydrological system responses in urban environments as infrastructure becomes increasingly threatened by the effects of climate change (e.g. more frequent and severe flooding). Urban hydrology can cause flooding by drainage systems reaching maximum capacity, precipitation exceeding soil infiltration capacity, groundwater rising above surface, or a combination of these processes. The high complexity of urban hydrology is strained by the interaction between natural hydrological systems with precipitation, overland flow, recharge, groundwater flow, and drainage systems with routing of water from paved areas toward finite drainage networks. In order to asses flood risks in the urban environment, a modelling system integrating the different interacting parts in the urban hydrology should be applied. In the presented study a well-known drainage water and sewage water model, MIKE URBAN based on MOUSE is coupled with a spatially distributed groundwater - surface water model including vadoze zone processes. The primary objective for the study is to improve subsurface urban hydrological predictability because previous studies have illustrated the incapability of a stand-alone groundwater model to simulate measured groundwater head variability beneath an urbanized area. The investigated urban area is located in the western part of Denmark where urban infrastructure is vulnerable against high groundwater levels. Groundwater head predictions benefit from the coupled modelling approach where paved urban zones (with drainage runoff) and green areas (with more naturally occurring recharge) are separated, thereby affecting dynamic groundwater levels.

  9. Modeling and monitoring the hydrological effects of the Sand Engine.

    NASA Astrophysics Data System (ADS)

    Schaars, Frans; Hoogmoed, Merel; van Vliet, Frank; Stuyfzand, Pieter; Groen, Michel; van der Made, Kees-Jan; Caljé, Ruben; Auken, Esben; Bergsted Pedersen, Jesper

    2013-04-01

    Since 1887, Dunea Water Company produces high quality drinking water using the dune area at Monster (Province of South Holland, the Netherlands). Annually, 8 billion liters of water is produced here using artificial recharge and recovery with shallow wells and infiltration lakes. The dunes are an important step in producing drinking water serving as an underground buffer, leveling fluctuating in temperature and quality and removing bacteria and viruses from the infiltrated water in a natural way. Since space is limited in the Netherlands, the drinking water production of Dunea is closely matched with surrounding land uses and natural constraints. This prevents groundwater nuisance, upconing and intrusion of salt water and, in this case, movement of a nearby groundwater pollution. This is especially true in the Monster area where the dunes are fairly low and small; the coast is less than 350 meters from the recovery wells. The coast of Monster was identified as a weak link in the coastal defense of The Netherlands. Because of this, two coastal defense projects were carried out between 2009 and 2011. The first project involved creating an extra dune ridge in front of existing dunes which leads to intrusion of a large volume of seawater. Directly after completion, the Sand Engine was constructed. This hook shaped sand peninsula will supply the coast with sand for the coming decades due to erosion and deposition along the coast. These two large coastal defense projects would obviously influence the tightly balanced hydrological system of Monster. Without hydrological intervention, the drinking water production would no longer be sustainable in this area. To study the effects of these projects and to find a solution to combine coastal defense and drinking water supply, field research and effect (geochemical) modeling were used interactively. To prevent negative effects it was decided to construct interception wells on top of the new dune ridge (28 in total). A comprehensive monitoring system was built to keep track of the salt groundwater and the groundwater heads. The zero measurement included groundwater heads, water samples, but also geophysical methods such as SkyTEM and CVES. We will also show the monitoring system we use to keep track of the groundwater heads and salt water intrusion in the future.

  10. Simulating the Effect of Uncertain Model Drivers on Hydrologic Predictions via an Approximate Bayesian Approach

    NASA Astrophysics Data System (ADS)

    Marshall, L. A.; Nott, D. J.

    2014-12-01

    Understanding the extent and effect of observational uncertainty remains a key concern in hydrologic model specification. Advances have been made in developing robust Bayesian approaches for characterizing the impact of uncertain climatological drivers on hydrologic predictions and parameters. However, these approaches are typically very high dimensional, requiring specification of large numbers of variables that represent statistical uncertainty in the model inputs. Recent developments in approximate Bayesian methods offer an elegant alternative to the fully Bayesian approach. Approximate Bayesian Computation (ABC) is commonly used in situations where a model is easy to simulate from, but where the likelihood is difficult or impossible to calculate. The ABC approach provides an opportunity to develop novel hydrologic statistics for model inference and to develop efficient methods for parameter identification in high dimensional hydrologic models. In this study, we demonstrate the use of approximate Bayesian methods for characterizing uncertain model inputs across multiple hydrologic case studies. Model inference is conducted via statistics that capture hydroclimatic and hydrologic functioning. Our analysis investigates the utility of ABC for model assessment, parameter identification and uncertainty characterization when dealing with potentially large observational uncertainties in hydroclimatic applications.

  11. Coupling Radar Rainfall to Hydrological Models for Water Abstraction Management

    NASA Astrophysics Data System (ADS)

    Asfaw, Alemayehu; Shucksmith, James; Smith, Andrea; MacDonald, Ken

    2015-04-01

    The impacts of climate change and growing water use are likely to put considerable pressure on water resources and the environment. In the UK, a reform to surface water abstraction policy has recently been proposed which aims to increase the efficiency of using available water resources whilst minimising impacts on the aquatic environment. Key aspects to this reform include the consideration of dynamic rather than static abstraction licensing as well as introducing water trading concepts. Dynamic licensing will permit varying levels of abstraction dependent on environmental conditions (i.e. river flow and quality). The practical implementation of an effective dynamic abstraction strategy requires suitable flow forecasting techniques to inform abstraction asset management. Potentially the predicted availability of water resources within a catchment can be coupled to predicted demand and current storage to inform a cost effective water resource management strategy which minimises environmental impacts. The aim of this work is to use a historical analysis of UK case study catchment to compare potential water resource availability using modelled dynamic abstraction scenario informed by a flow forecasting model, against observed abstraction under a conventional abstraction regime. The work also demonstrates the impacts of modelling uncertainties on the accuracy of predicted water availability over range of forecast lead times. The study utilised a conceptual rainfall-runoff model PDM - Probability-Distributed Model developed by Centre for Ecology & Hydrology - set up in the Dove River catchment (UK) using 1km2 resolution radar rainfall as inputs and 15 min resolution gauged flow data for calibration and validation. Data assimilation procedures are implemented to improve flow predictions using observed flow data. Uncertainties in the radar rainfall data used in the model are quantified using artificial statistical error model described by Gaussian distribution and propagated through the model to assess its influence on the forecasted flow uncertainty. Furthermore, the effects of uncertainties at different forecast lead times on potential abstraction strategies are assessed. The results show that over a 10 year period, an average of approximately 70 ML/d of potential water is missed in the study catchment under a convention abstraction regime. This indicates a considerable potential for the use of flow forecasting models to effectively implement advanced abstraction management and more efficiently utilize available water resources in the study catchment.

  12. Hydrological modelling of a small catchment using SWAT-2000 Ensuring correct flow partitioning for contaminant modelling

    NASA Astrophysics Data System (ADS)

    Kannan, N.; White, S. M.; Worrall, F.; Whelan, M. J.

    2007-02-01

    SummaryThe performance of the SWAT-2000 model was evaluated using stream flow at the outlet of the 142 ha Colworth catchment (Bedfordshire, UK). This catchment has been monitored since October 1999. The soil type consists of clay loam soil over stony calcareous clay and a rotation of wheat, oil seed rape, grass, beans and peas is grown. Much of the catchment is tile drained. Acceptable performance in hydrological modelling, along with correct simulation of the processes driving the water balance were essential first requirements for predicting contaminant transport. Initial results from SWAT-2000 identified some necessary modifications in the model source code for correct simulation of processes driving water balance. After modification of the code, hydrological simulation, crop growth and evapotranspiration (ET) patterns were realistic when compared with empirical data. Acceptable model performance (based on a number of error measures) was obtained in final model runs, with reasonable runoff partitioning into overland flow, tile drainage and base flow.

  13. APPLICATION OF SWAT HYDROLOGIC MODEL FOR TMDL DEVELOPMENT ON CHAPEL BRANCH CREEK WATERSHED, SC

    Microsoft Academic Search

    D. M. Amatya; T. M. Williams; A. E. Edwards; N. S. Levine; D. R. Hitchcock

    Watershed-scale hydrologic\\/water quality models are frequently used to characterize flow dynamics, pathways, and pollutant loading rates as a function of land use, soils, topography, management practices, and their interactions with variability in climate. SWAT (Soil and Water Assessment Tool) is a widely used GIS-based basin scale model to quantify the impact of land management practices on hydrology and water quality

  14. eWaterCycle: Developing a hyper resolution global hydrological model

    NASA Astrophysics Data System (ADS)

    Sutanudjaja, Edwin; Hut, Rolf; Drost, Niels; Steele-Dunne, Susan; de Jong, Kor; van Beek, Ludovicus; Karssenberg, Derek; van de Giesen, Nick; Bierkens, Marc

    2013-04-01

    The development of a high resolution global hydrological model has recently been put forward as Grand Challenge for the hydrological community (Wood et al., 2011). The current version of the global hydrological model PCR-GLOBWB (van Beek et al., 2011) runs at a relatively coarse spatial grid (i.e. 0.1° or about 10 km at the equator), which is well above the hyper resolution envisioned in the Grand Challenge (i.e. 100 m). The eWaterCycle project aims at developing a high resolution global hydrological model allowing for a better representation of the effects of spatial heterogeneity in topography, soil, and vegetation on hydrological dynamics. Here we modify PCR-GLOBWB so that it runs at much higher resolution, on the order of 1 km or finer, that will be relevant for addressing critical water cycle science questions and many hydrological applications such as assessing water resources sustainability, flood and drought frequency under climate change. The development of such a hyper resolution model requires utilizing recent computational advances and massive parallel computer systems. So far, the hydrological community has not yet made full use of such possibilities. The eWaterCycle is a close cooperation between hydrologists (Delft University of Technology and Utrecht University) and the Netherlands eScience Center (NleSC) - that intends to supports and reinforce data-intensive research through creative and innovative use of information and communication technology (ICT). The hyper resolution model built in this project will contribute to the current scientific state-of-the-art by combining hydrological knowledge with ICT challenges. The refinement of the current model would be a huge step forward, because increasing resolution also requires adding an explicit spatial representation of local processes (groundwater flow, water diversions, glaciers, etc.) that will greatly enhance the regional to local applicability of global models. We also argue that the result envisions a qualitative jump in the quality of existing hydrological models. The scientific community will benefit in the field of hydrology, as well as in the fields of ICT and mathematics. As the results will be shared, the novel hydrological model will be available for other researchers and other organizations in order to elaborate further and to enrich and extend the model.

  15. Therapeutic vaccines in HBV: lessons from HCV.

    PubMed

    Barnes, Eleanor

    2015-02-01

    Currently, millions of people infected with hepatitis B virus (HBV) are committed to decades of treatment with anti-viral therapy to control viral replication. However, new tools for immunotherapy that include both viral vectors and molecular checkpoint inhibitors are now available. This has led to a resurgence of interest in new strategies to develop immunotherapeutic strategies with the aim of inducing HBeAg seroconversion--an end-point that has been associated with a decrease in the rates of disease progression. Ultimately, a true cure will involve the elimination of covalently closed circular DNA which presents a greater challenge for immunotherapy. In this manuscript, I describe the development of immunotherapeutic strategies for HBV that are approaching or currently in clinical studies, and draw on observations of T cell function in natural infection supported by recent animal studies that may lead to additional rational vaccine strategies using checkpoint inhibitors. I also draw on our recent experience in developing potent vaccines for HCV prophylaxis based on simian adenoviral and MVA vectors used in prime-boost strategies in both healthy volunteers and HCV infected patients. I have shown that the induction of T cell immune responses is markedly attenuated when administered to people with persistent HCV viremia. These studies and recently published animal studies using the woodchuck model suggest that potent vaccines based on DNA or adenoviral vectored vaccination represent a rational way forward. However, combining these with drugs to suppress viral replication, alongside checkpoint inhibitors may be required to induce long-term immune control. PMID:25573348

  16. Hydrological minimal model for fire regime assessment in a Mediterranean ecosystem

    NASA Astrophysics Data System (ADS)

    Ursino, Nadia; Rulli, Maria Cristina

    2011-11-01

    A new model for Mediterranean forest fire regime assessment is presented and discussed. The model is based on the experimental evidence that fire is due to both hydrological and ecological processes and the relative role of fuel load versus fuel moisture is an important driver in fire ecology. Diverse scenarios are analyzed where either the hydrological forcing or the feedback between fire and hydrological characterization of the site is changed. The model outcome demonstrates that the two-way interaction between hydrological processes, biology, and fire regime drives the ecosystem toward a typical fire regime that may be altered either by an evolution of the biological characterization of the site or by a change of the hydrological forcing. This tenet implies that not every fire regime is compatible with the ecohydrological characterization of the site under study. This means that natural (nonantropogenic) fire cannot be modeled as an arbitrary external forcing because the coupled hydrological and biological processes determines its statistical characterization, and conversely, the fire regime affects the soil moisture availability and the outcome of different species competition under possible water stress. The new modeling approach presented here, when provided by a proper model parameterization, can advance the capability in predicting and managing fires in ecosystems influenced by climate and land use changes.

  17. Adeno-Associated Virus Vector Mediated Delivery of the HBV Genome Induces Chronic Hepatitis B Virus Infection and Liver Fibrosis in Mice

    PubMed Central

    Ye, Lei; Yu, Haisheng; Li, Chengwen; Hirsch, Matthew L.; Zhang, Liguo; Samulski, R. Jude; Li, Wuping; Liu, Zhong

    2015-01-01

    Liver cirrhosis and hepatocellular carcinomas are major health problems of chronic hepatitis B virus (HBV) infection. To date, rare model has reproduced liver fibrosis associated with long-term HBV infection which in turn has hindered both the understanding of HBV biology and the development of new treatment options. Here, using adeno-associated virus serotype 8 (AAV8) mediated delivery of a 1.2-kb HBV genome, we successfully generated a chronic HBV infectious mouse model that presents the associated liver fibrosis observed following human infection. After AAV8/HBV1.2 vector administration, mice demonstrated effective HBV replication and transcription which resulted in HBV antigen expression and viremia over 6 months. Although no obvious acute inflammatory response was noted, these mice still developed chronic liver disease and hepatic fibrogenesis as demonstrated by increased ground glass-like hepatocytes, an increasing trend of collagen deposition and upregulated fibrosis markers, including type I collagen, type III collagen, tissue inhibitor of metalloproteinase (TIMP), and transforming growth factor-?1(TGF-?1). Taken together, AAV-mediated HBV gene delivery to the mouse liver, induced HBV persistent infection accompanied by liver fibrosis which can serve as a model for investigating the precise mechanisms underlying liver fibrosis following chronic HBV infection as well as for the potential development of novel therapeutics. PMID:26075890

  18. Hydrological modelling of changing catchments: lessons from a common testing experiment

    NASA Astrophysics Data System (ADS)

    Thirel, Guillaume; Andréassian, Vazken; Perrin, Charles

    2015-04-01

    This communication will present a summary of the outcomes of a workshop session held in Gothenburg (Sweden) during the International Association of Hydrological Sciences (IAHS) General Assembly in 2013 on the topic of modelling of temporally-varying catchments, i.e. catchments that exhibit significant changes in their physical or climate conditions over a period of record. This workshop aimed at contributing to the Panta Rhei IAHS decade by offering a tribune to modellers to debate on hydrological modelling under change. For this workshop, the participants had been invited to apply a calibration and evaluation protocol to their own hydrological models on a given set of changing catchments and to come to Gothenburg to present their results (Thirel et al., 2015a). It was recognized that this protocol, based on calibration and evaluation over contrasted periods, is an appropriate way of assessing the suitability of hydrological models to handle changing conditions. Some modellers saw this exercise as an opportunity to confront their models to conditions different from their usual application area, or to use models to better understand hydrological changes. The crucial need for dedicated protocols to evaluate models under change was also stressed by some modellers who proposed complementary testing protocols (Thirel et al., 2015b). It is of utmost importance that studies for which models are applied under extreme conditions (meaning conditions very different from their calibration conditions) are performed using well-defined protocols. Several challenges for future research to improve the hydrological modelling of changing catchments were discussed during the workshop and will be presented. References Thirel G., V. Andréassian, C. Perrin, J.-N. Audouy, L. Berthet, P. Edwards, N. Folton, C. Furusho, A. Kuentz, J. Lerat, G. Lindström, E. Martin, T. Mathevet, R. Merz, J. Parajka, D. Ruelland, J. Vaze. Hydrology under change: an evaluation protocol to investigate how hydrological models deal with changing catchments. Hydrological Sciences Journal, 2015a. DOI:10.1080/02626667.2014.967248 Thirel G., V. Andréassian, C. Perrin. Editorial: Modelling Temporally-variable Catchments. Hydrological Sciences Journal, 2015b, under review.

  19. Model initialisation, data assimilation and probabilistic flood forecasting for distributed hydrological models

    NASA Astrophysics Data System (ADS)

    Cole, S. J.; Robson, A. J.; Bell, V. A.; Moore, R. J.

    2009-04-01

    The hydrological forecasting component of the Natural Environment Research Council's FREE (Flood Risk from Extreme Events) project "Exploitation of new data sources, data assimilation and ensemble techniques for storm and flood forecasting" addresses the initialisation, data assimilation and uncertainty of hydrological flood models utilising advances in rainfall estimation and forecasting. Progress will be reported on the development and assessment of simple model-initialisation and state-correction methods for a distributed grid-based hydrological model, the G2G Model. The potential of the G2G Model for area-wide flood forecasting is demonstrated through a nationwide application across England and Wales. Probabilistic flood forecasting in spatial form is illustrated through the use of high-resolution NWP rainfalls, and pseudo-ensemble forms of these, as input to the G2G Model. The G2G Model is configured over a large area of South West England and the Boscastle storm of 16 August 2004 is used as a convective case study. Visualisation of probabilistic flood forecasts is achieved through risk maps of flood threshold exceedence that indicate the space-time evolution of flood risk during the event.

  20. Constraining a Distributed Hydrologic Model Using Process Constraints derived from a Catchment Perceptual Model

    NASA Astrophysics Data System (ADS)

    Hutton, Christopher; Wagener, Thorsten; Freer, Jim; Han, Dawei; Duffy, Chris; Musuuza, Jude; Zhang, Jun

    2015-04-01

    The increased availability of spatial datasets and hydrological monitoring techniques improves the potential to apply distributed hydrologic models robustly to simulate catchment systems. However, distributed catchment modelling remains problematic for several reasons, including the miss-match between the scale of process equations and observations, and the scale at which equations (and parameters) are applied at the model grid resolution. A key problem is that when equations are solved over a distributed grid of the catchment system, models contain a considerable number of distributed parameters, and therefore degrees of freedom, that need to be constrained through calibration. Often computational limitations alone prohibit a full search of the multidimensional parameter space. However, even when possible, insufficient data results in model parameter and/or structural equifinality. Calibration approaches therefore attempt to reduce the dimensions of parameter space to constrain model behaviour, typically by fixing, lumping or relating model parameters in some way when calibrating the model to time-series of response data. An alternative approach to help reduce the space of feasible models has been applied to lumped and semi-distributed models, where additional, often semi-qualitative information is used to constrain the internal states and fluxes of the model, which in turn help to identify feasible sets of model structures and parameters. Such process constraints have not been widely applied to distributed hydrological models, despite the fact that distributed models make more predictions of distributed states and fluxes that can potentially be constrained. This paper presents a methodology for deriving process and parameter constraints through development of a perceptual model for a given catchment system, which can then be applied in distributed model calibration and sensitivity analysis to constrain feasible parameter and model structural space. We argue that the perceptual model of a catchment - a set of perceptions codified in some lingual, pictorial, mathematical or symbolic form that represents a current state of understanding about a catchment system - should be derived independently from any modelling exercise. Such a perceptual model should be constructed hierarchically in space and time, and contain constraints on our understanding of the magnitude of stores and fluxes in the system at different scales - typically in the form of inequalities or intervals. Such information can then be applied to constrain model behaviour, depending on the mapping between process constraints and model states. We derive a perceptual model of the Plynlimon catchment (UK), and investigate the ability of different process and parameter constraints derived from the perceptual model, based on different levels of data availability, to constrain the Penn State Integrated Hydrologic Modeling System (PIHM) when applied to the catchment.

  1. High performance computing (HPC) based hydrological modelling framework to support complex model-coupling and uncertainty studies

    NASA Astrophysics Data System (ADS)

    Xuan, Yunqing; Zhu, Dehua

    2014-05-01

    We have recently initiated a framework of HPC based hydrological modelling system that intends to couple hydrological model and numerical weather prediction on a unified platform. The framework is intended to achieve 1) seamlessly coupling of the hydrological models with the climate/numerical weather models that are supported by the same HPC platform; 2) supporting large-scale hydrological modelling in greater details; 3) conducting joint ensemble runs of coupled modelling systems so as to account for the modelling uncertainty; 4) supporting multi-model ensembles to identify potential extreme storms with certain climate projections; 5) the ability of processing large volume of data (terabyte level). At current stage, we are focusing on the design and implementation of a versatile interface between the two backend NWPs (Unified Model from UK Met Office & WRF from NCAR) to a number of preferred hydrological models. The expected outcome will serve well the research community and practitioners in terms of providing an easy-access modelling platform as well as providing benchmarking datasets from tailor-made experiments. Keywords: Coupled models, Hydrological modelling, High Performance Computing, Unified Model, WRF, Multi-model ensembles

  2. Utilizing Satellite-based and Reanalysis Precipitation Data in Hydrological Modeling

    NASA Astrophysics Data System (ADS)

    Ignatius, A. R.; Grundstein, A.; Rasmussen, T. C.; Mote, T. L.; Shepherd, J. M.

    2010-12-01

    Precipitation is an essential input into surface hydrologic models. While rain gauges are the most common source for precipitation data, many regions suffer from a paucity of precipitation data at appropriate temporal and spatial resolutions. Satellite-based or gridded reanalysis data sources provide alternative rainfall inputs for hydrologic models. The University of Georgia and U.S. Dept. of Energy Savannah River National Laboratory are investigating complex hydrometeorological and source attribution problems using a combination of hydrologic observations and models. The project investigates the use several NASA products including TRMM 3B42, TRMM 3B42RT, and MERRA (Modern Era Retrospective-Analysis for Research and Applications) reanalysis data. These data are used as meteorological inputs for a hydrologic model of the Savannah River watershed, located in Georgia and South Carolina. Hydrologic simulations are performed using the BASINS 4.0 (Better Assessment Science Integrating Point and Non-Point Sources) environmental analysis system and the HSPF hydrologic model. Validation studies of the precipitation datasets along with comparisons of streamflow simulations using the alternative inputs will be presented. The work represents a synergy of scientific analysis and stakeholder applications that the forthcoming GPM era can leverage.

  3. A simple hydrologically based model of land surface water and energy fluxes for general circulation models

    NASA Technical Reports Server (NTRS)

    Liang, XU; Lettenmaier, Dennis P.; Wood, Eric F.; Burges, Stephen J.

    1994-01-01

    A generalization of the single soil layer variable infiltration capacity (VIC) land surface hydrological model previously implemented in the Geophysical Fluid Dynamics Laboratory (GFDL) general circulation model (GCM) is described. The new model is comprised of a two-layer characterization of the soil column, and uses an aerodynamic representation of the latent and sensible heat fluxes at the land surface. The infiltration algorithm for the upper layer is essentially the same as for the single layer VIC model, while the lower layer drainage formulation is of the form previously implemented in the Max-Planck-Institut GCM. The model partitions the area of interest (e.g., grid cell) into multiple land surface cover types; for each land cover type the fraction of roots in the upper and lower zone is specified. Evapotranspiration consists of three components: canopy evaporation, evaporation from bare soils, and transpiration, which is represented using a canopy and architectural resistance formulation. Once the latent heat flux has been computed, the surface energy balance is iterated to solve for the land surface temperature at each time step. The model was tested using long-term hydrologic and climatological data for Kings Creek, Kansas to estimate and validate the hydrological parameters, and surface flux data from three First International Satellite Land Surface Climatology Project Field Experiment (FIFE) intensive field campaigns in the summer-fall of 1987 to validate the surface energy fluxes.

  4. Hydrologic analysis of a flood based on a new Digital Elevation Model

    NASA Astrophysics Data System (ADS)

    Nishio, M.; Mori, M.

    2015-06-01

    These The present study aims to simulate the hydrologic processes of a flood, based on a new, highly accurate Digital Elevation Model (DEM). The DEM is provided by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) of Japan, and has a spatial resolution of five meters. It was generated by the new National Project in 2012. The Hydrologic Engineering Center - Hydrologic Modeling System (HEC-HMS) is used to simulate the hydrologic process of a flood of the Onga River in Iizuka City, Japan. A large flood event in the typhoon season in 2003 caused serious damage around the Iizuka City area. Precise records of rainfall data from the Automated Meteorological Data Acquisition System (AMeDAS) were input into the HEC-HMS. The estimated flood area of the simulation results by HEC-HMS was identical to the observed flood area. A watershed aggregation map is also generated by HEC-HMS around the Onga River.

  5. Modeling the effect of glacier recession on streamflow response using a coupled glacio-hydrological model

    NASA Astrophysics Data System (ADS)

    Naz, B. S.; Frans, C. D.; Clarke, G. K. C.; Burns, P.; Lettenmaier, D. P.

    2014-02-01

    We describe an integrated spatially distributed hydrologic and glacier dynamic model, and use it to investigate the effect of glacier recession on streamflow variations for the upper Bow River basin, a tributary of the South Saskatchewan River, Alberta, Canada. Several recent studies have suggested that observed decreases in summer flows in the South Saskatchewan River are partly due to the retreat of glaciers in the river's headwaters. Modeling the effect of glacier changes on streamflow response in river basins such as the South Saskatchewan is complicated due to the inability of most existing physically based distributed hydrologic models to represent glacier dynamics. We compare predicted variations in glacier extent, snow water equivalent (SWE), and streamflow discharge with satellite estimates of glacier area and terminus position, observed glacier mass balance, observed streamflow and snow water-equivalent measurements, respectively over the period of 1980-2007. Observations of multiple hydroclimatic variables compare well with those simulated with the coupled hydrology-glacier model. Our results suggest that, on average, the glacier melt contribution to the Bow River flow upstream of Lake Louise is approximately 22% in summer. For warm and dry years, however, the glacier melt contribution can be as large as 47% in August, whereas for cold years, it can be as small as 15% and the timing of the glacier melt signature can be delayed by a month. The development of this modeling approach sets the stage for future predictions of the influence of warming climate on streamflow in partially glacierized watersheds.

  6. Modeling the effect of glacier recession on streamflow response using a coupled glacio-hydrological model

    NASA Astrophysics Data System (ADS)

    Naz, B. S.; Frans, C. D.; Clarke, G. K. C.; Burns, P.; Lettenmaier, D. P.

    2013-04-01

    We describe an integrated spatially distributed hydrologic and glacier dynamic model, and use it to investigate the effect of glacier recession on streamflow variations for the Upper Bow River basin, a tributary of the South Saskatchewan River. Several recent studies have suggested that observed decreases in summer flows in the South Saskatchewan River are partly due to the retreat of glaciers in the river's headwaters. Modeling the effect of glacier changes on streamflow response in river basins such as the South Saskatchewan is complicated due to the inability of most existing physically-based distributed hydrologic models to represent glacier dynamics. We compare predicted variations in glacier extent, snow water equivalent and streamflow discharge made with the integrated model with satellite estimates of glacier area and terminus position, observed streamflow and snow water equivalent measurements over the period of 1980-2007. Simulations with the coupled hydrology-glacier model reduce the uncertainty in streamflow predictions. Our results suggested that on average, the glacier melt contribution to the Bow River flow upstream of Lake Louise is about 30% in summer. For warm and dry years, however, the glacier melt contribution can be as large as 50% in August, whereas for cold years, it can be as small as 20% and the timing of glacier melt signature can be delayed by a month.

  7. Parental attitude towards childhood HBV vaccination in The Netherlands

    Microsoft Academic Search

    Jan A. C. Hontelez; Susan J. M. Hahné; Petra Oomen; Hester de Melker

    2010-01-01

    In The Netherlands, children with at least one parent born in a hepatitis B virus (HBV) endemic country are offered HBV vaccination within the National Immunization Programme (NIP) since 2003. However, in the eligible group the HBV vaccine coverage is lower than the DPT-IPV-Hib coverage. We therefore conducted a questionnaire survey in order to determine the acceptance of HBV vaccination

  8. Identifying influential data points in hydrological model calibration and their impact on streamflow predictions

    NASA Astrophysics Data System (ADS)

    Wright, David; Thyer, Mark; Westra, Seth

    2015-04-01

    Highly influential data points are those that have a disproportionately large impact on model performance, parameters and predictions. However, in current hydrological modelling practice the relative influence of individual data points on hydrological model calibration is not commonly evaluated. This presentation illustrates and evaluates several influence diagnostics tools that hydrological modellers can use to assess the relative influence of data. The feasibility and importance of including influence detection diagnostics as a standard tool in hydrological model calibration is discussed. Two classes of influence diagnostics are evaluated: (1) computationally demanding numerical "case deletion" diagnostics; and (2) computationally efficient analytical diagnostics, based on Cook's distance. These diagnostics are compared against hydrologically orientated diagnostics that describe changes in the model parameters (measured through the Mahalanobis distance), performance (objective function displacement) and predictions (mean and maximum streamflow). These influence diagnostics are applied to two case studies: a stage/discharge rating curve model, and a conceptual rainfall-runoff model (GR4J). Removing a single data point from the calibration resulted in differences to mean flow predictions of up to 6% for the rating curve model, and differences to mean and maximum flow predictions of up to 10% and 17%, respectively, for the hydrological model. When using the Nash-Sutcliffe efficiency in calibration, the computationally cheaper Cook's distance metrics produce similar results to the case-deletion metrics at a fraction of the computational cost. However, Cooks distance is adapted from linear regression with inherit assumptions on the data and is therefore less flexible than case deletion. Influential point detection diagnostics show great potential to improve current hydrological modelling practices by identifying highly influential data points. The findings of this study establish the feasibility and importance of including influential point detection diagnostics as a standard tool in hydrological model calibration. They provide the hydrologist with important information on whether model calibration is susceptible to a small number of highly influent data points. This enables the hydrologist to make a more informed decision of whether to (1) remove/retain the calibration data; (2) adjust the calibration strategy and/or hydrological model to reduce the susceptibility of model predictions to a small number of influential observations.

  9. Parsimonious modeling of hydrologic responses in engineered watersheds: Structural heterogeneity versus functional homogeneity

    Microsoft Academic Search

    Nandita B. Basu; P. S. C. Rao; H. Edwin Winzeler; Sanjiv Kumar; Phillip Owens; Venkatesh Merwade

    2010-01-01

    The central premise of this paper is that extensive modifications of land use and hydrology, coupled with intensive management of watersheds in the Midwestern United States over the past century, have increased the predictability of hydrologic responses, allowing for the use of simpler, minimum-calibration models. In these engineered watersheds, extensive tile-and-ditch networks have increased the effective drainage density and have

  10. Modeling Vegetation Dynamics in Response to Hydrological Changes in a Small Urban Tropical Freshwater Wetland

    NASA Astrophysics Data System (ADS)

    Chui, T. M.; Palanisamy, B.; Mohanadas, H.

    2011-12-01

    Wetlands worldwide face drastic degradation from human-induced changes. A small freshwater wetland located within the dense urbanized island state of Singapore---the Nee Soon Wetland---is no exception. It is the only significant locality in Singapore of peat swamp forest and is home to a wide range of rare and endangered floral and faunal species. Unfortunately, changes in downstream land use and surrounding reservoirs' operations may pose threats to the coupled hydrological and vegetation systems. This study develops and applies coupled hydrological-vegetation models to understand the dynamic relationships between hydrology and vegetation systems, and simulates vegetation responses to hydrological changes in Nee Soon. The models combine a hydrological component with a vegetation component. The hydrological component accounts for both saturated and unsaturated flows, and incorporates evapotranspiration, rainfall infiltration and recharge from streams and reservoirs. The vegetation component is described by Lokta-Volterra equations that are tailored for plant growth, to simulate the vegetation dynamics of up to three species that thrive in different flooding conditions. Important findings include: (1) groundwater levels within Nee Soon are not highly sensitive to the operating levels of the surrounding reservoirs. However, (2) downstream drainage results in a localized zone of influence with significant adverse impacts, especially on the less flood-tolerant species. In addition, (3) the severely impacted less flood-tolerant species is unable to recover even when previous hydrological conditions are restored, unless the downstream drainage duration is reduced, or the plant characteristics such as maximum assimilation rates or competitiveness are increased. Finally, (4) hydrological conditions and species competitiveness supersede any other plant growth characteristics in determining the stable coexistence of different species. The developed models and modeling results simulation results help preservation efforts and guide conservation strategies in Nee Soon, as well as many wetlands worldwide.

  11. Modeling and Analysis of Global and Regional Climate Change in Relation to Atmospheric Hydrologic Processes

    NASA Technical Reports Server (NTRS)

    Johnson, Donald R.

    2001-01-01

    This research was directed to the development and application of global isentropic modeling and analysis capabilities to describe hydrologic processes and energy exchange in the climate system, and discern regional climate change. An additional objective was to investigate the accuracy and theoretical limits of global climate predictability which are imposed by the inherent limitations of simulating trace constituent transport and the hydrologic processes of condensation, precipitation and cloud life cycles.

  12. Modelling Gravimetric Fluctuations due to Hydrological Processes in Active Volcanic Settings

    NASA Astrophysics Data System (ADS)

    Hemmings, B.; Gottsmann, J.; Whitaker, F.

    2014-12-01

    Both static and dynamic gravimetric surveys are widely used to monitor magmatic processes in active volcanic settings. However, attributing residual gravimetric signals solely to magma movement can result in misdiagnosis of a volcano's pre-eruptive state and incorrect assessment of hazard. The relative contribution of magmatic and aqueous fluids to integrated gravimetric and geodetic data has become an important topic for debate, particularly in restless caldera systems. Groundwater migration driven by volcanically-induced pressure changes, and groundwater mass fluctuations associated with seasonal and inter-annual variations in recharge may also contribute to measured gravity changes. Here we use numerical models to explore potential gravimetric signals associated with fundamental hydrological processes, focusing on variations in recharge and hydrogeological properties. TOUGH2 simulations demonstrate the significance of groundwater storage within a thick unsaturated zone (up to 100 m). Changes are dominantly in response to inter-annual recharge variations and can produce measurable absolute gravity variations of several 10s of ?gal. Vadose zone storage and the rate of response to recharge changes depend on the hydrological properties. Porosity, relative and absolute permeability and capillary pressure conditions all affect the amplitude and frequency of modelled gravity time series. Spatial variations in hydrologic properties and importantly, hydrological recharge, can significantly affect the phase and amplitude of recorded gravity signals. Our models demonstrate the potential for an appreciable hydrological component within gravimetric measurements on volcanic islands. Characterisation of hydrological processes within a survey area may be necessary to robustly interpret gravity signals in settings with significant recharge fluctuations, a thick vadose zone and spatially variable hydrological properties. Such modelling enables further exploration of feedbacks between volcanic and hydrological systems, and the geophysical signals used to monitor them.

  13. Development of An Integrated Hydrologic Model in Yolo County, California

    NASA Astrophysics Data System (ADS)

    Liang, Y.; Taghavi, A.; Stevenson, M.; Najmus, S.

    2006-12-01

    To more efficiently use the Cache Creek flows and the groundwater basin as the sources of water supply and to restore the riparian ecosystem along the Cache Creek, Yolo County Flood Control and Water Conservation District (YCFCWCD) in Woodland, California plans to conduct the Cache Creek Groundwater Recharge and Recovery Program (CCGRRP). The concept of this program is to operate the groundwater basin to induce greater amounts of groundwater recharge from Cache Creek directly along the creek and to increase the recharge even further by diverting rainy season water at the District's Capay Diversion Dam into the West Adams Canal to a few recharge basins outside the active channel of Cache Creek. Besides the CCGRRP, cities of Woodland and Davis are in the process of conducting groundwater management plans, and the stakeholders in Yolo County developing a long-term integrated regional water management plan (IRWMP) for the entire county. To effectively evaluate the benefits and impacts of CCGRRP, local groundwater management plans, and the Yolo County IRWMP, the Integrated Groundwater and Surface water Model (IGSM) was applied to the Yolo groundwater basin. The IGSM is a comprehensive integrated hydrologic model that simulates both surface water and groundwater flow systems, including rainfall-runoff, soil moisture accounting and unsaturated flow, crop consumptive module, stream-aquifer interaction, and groundwater flow. The finite element code was originally developed in 1990 for the California Department of Water Resources and the State Water Resources Control Board. The IGSM code has subsequently been applied to more than 25 groundwater basins in California and other states. The model code has been peer reviewed and upgraded throughout its application to various projects, with the latest upgrade in 2004, as part of the application to the Stony Creek Fan area of Sacramento Valley. The Yolo County IGSM (YCIGSM) was calibrated against the historical (1970-2000) groundwater level records at 105 monitoring wells, and three streamflow gages along Cache Creek. Calibration results show that the YCIGSM is able to reasonably simulate the long-term groundwater level trends and short-term seasonal fluctuations. The YCIGSM will be used to develop operational guidelines to manage the groundwater basin, to determine the optimum yield of water projects, to identify benefits and impacts of projects on existing groundwater users, and to assess the environmental benefits and impacts during the development of projects, as well as during the environmental permitting process.

  14. Evaluating hydrological model structure using tracer data within a multi-model framework

    NASA Astrophysics Data System (ADS)

    McMillan, H. K.; Tetzlaff, D.; Clark, M. P.; Soulsby, C.

    2011-12-01

    This presentation describes the use of tracer dynamics as an orthogonal data source to assist the choice of model structure within a multi-model framework. Tracers are a valuable model diagnostic tool because they provide information about integrated catchment response from an alternative perspective to the commonly-used rainfall and runoff dynamics. Their integrated nature makes them especially suitable for assessment of lumped conceptual hydrological models. The hydrological community is embracing the concept that model structure should be designed according to catchment function, and rejecting the former 'one-size-fits-all' approach. The FUSE multi-model framework is one example of this which allows independent control of model choices in representing a range of storages and fluxes. In order to use tracer data to help choose model structure, we extended the FUSE modules to allow each input of water (e.g. hourly precipitation totals) to be tracked through the conceptual storages. Quantities such as tracer output dynamics, transit time distributions and mean transit times can then be calculated and compared against observed tracer data. By varying individual model components in FUSE (e.g. structure of soil zone, structure of groundwater zone) the effect of model structure on the accuracy of tracer dynamics can be established. We demonstrate the use of this new method in a case study in the intensively monitored Loch Ard catchments in Scotland. A variety of model structures are selected and compared in their ability to reproduce both runoff dynamics and tracer dynamics as observed in the catchments. We also relate the model structures to existing knowledge of the dominant runoff generation processes. Results show that tracer data provides an ability to discriminate between common hydrological model structures even when performance in reproducing runoff dynamics is similar.

  15. HYDROGEOCHEM: A coupled model of HYDROlogic transport and GEOCHEMical equilibria in reactive multicomponent systems

    SciTech Connect

    Yeh, G.T.; Tripathi, V.S.

    1990-11-01

    This report presents the development of a hydrogeochemical transport model for multicomponent systems. The model is designed for applications to proper hydrological setting, accommodation of complete suite of geochemical equilibrium processes, easy extension to deal with chemical kinetics, and least constraints of computer resources. The hydrological environment to which the model can be applied is the heterogeneous, anisotropic, saturated-unsaturated subsurface media under either transient or steady state flow conditions. The geochemical equilibrium processes included in the model are aqueous complexation, adsorption-desorption, ion exchange, precipitation-dissolution, redox, and acid-base reactions. To achieve the inclusion of the full complement of these geochemical processes, total analytical concentrations of all chemical components are chosen as the primary dependent variables in the hydrological transport equations. Attendant benefits of this choice are to make the extension of the model to deal with kinetics of adsorption-desorption, ion exchange, precipitation-dissolution, and redox relatively easy. To make the negative concentrations during the iteration between the hydrological transport and geochemical equilibrium least likely, an implicit form of transport equations are proposed. To alleviate severe constraints of computer resources in terms of central processing unit (CPU) time and CPU memory, various optional numerical schemes are incorporated in the model. The model consists of a hydrological transport module and geochemical equilibrium module. Both modules were thoroughly tested in code consistency and were found to yield plausible results. The model is verified with ten examples. 79 refs., 21 figs., 17 tabs.

  16. Physically-Based Distributed-Parameter Hydrologic Modeling of the Bull Creek Watershed, Austin, Texas

    NASA Astrophysics Data System (ADS)

    Sparks, L. B.; Sharif, H. O.; French, R. H.

    2007-05-01

    Recent advances in computing power, data storage and the increased availability of spatially distributed data sets have encouraged research into the benefits and potential applications of physically-based, distributed hydrologic models. Physically-based, distributed parameter, structured grid models simulate watershed processes using physics-based equations, such as energy, momentum and continuity. Hydrologic parameters are specified for each grid cell within the model domain in an effort to best represent the spatial variability of watershed characteristics. The intent of this study is to contribute to the ongoing effort to evaluate the physically-based, distributing modeling approach for hydrologic study, flood forecasting and other applications. The hydrology of a partially urbanized watershed located in Austin, Texas is simulated using the physically-based, distributed parameter model Surface Subsurface Hydrologic Analysis (GSSHA). GIS-based data sets, collected from publicly available sources and the City of Austin Watershed Protection Division, were processed using ArcGIS version 9.1 and the Watershed Modeling System graphical modeling environment. NEXRAD precipitation data for three significant rain events were processed and quality-controlled using rain-gauge observations. Model-generated hydrographs for these events were compared to observed flow data at a USGS flow gage located at the basin outlet.

  17. A unified approach for process-based hydrologic modeling: 2. Model implementation and case studies

    NASA Astrophysics Data System (ADS)

    Clark, Martyn P.; Nijssen, Bart; Lundquist, Jessica D.; Kavetski, Dmitri; Rupp, David E.; Woods, Ross A.; Freer, Jim E.; Gutmann, Ethan D.; Wood, Andrew W.; Gochis, David J.; Rasmussen, Roy M.; Tarboton, David G.; Mahat, Vinod; Flerchinger, Gerald N.; Marks, Danny G.

    2015-04-01

    This work advances a unified approach to process-based hydrologic modeling, which we term the "Structure for Unifying Multiple Modeling Alternatives (SUMMA)." The modeling framework, introduced in the companion paper, uses a general set of conservation equations with flexibility in the choice of process parameterizations (closure relationships) and spatial architecture. This second paper specifies the model equations and their spatial approximations, describes the hydrologic and biophysical process parameterizations currently supported within the framework, and illustrates how the framework can be used in conjunction with multivariate observations to identify model improvements and future research and data needs. The case studies illustrate the use of SUMMA to select among competing modeling approaches based on both observed data and theoretical considerations. Specific examples of preferable modeling approaches include the use of physiological methods to estimate stomatal resistance, careful specification of the shape of the within-canopy and below-canopy wind profile, explicitly accounting for dust concentrations within the snowpack, and explicitly representing distributed lateral flow processes. Results also demonstrate that changes in parameter values can make as much or more difference to the model predictions than changes in the process representation. This emphasizes that improvements in model fidelity require a sagacious choice of both process parameterizations and model parameters. In conclusion, we envisage that SUMMA can facilitate ongoing model development efforts, the diagnosis and correction of model structural errors, and improved characterization of model uncertainty.

  18. Application of Hierarchy Theory to Cross-Scale Hydrologic Modeling of Nutrient Loads

    EPA Science Inventory

    We describe a model called Regional Hydrologic Modeling for Environmental Evaluation 16 (RHyME2) for quantifying annual nutrient loads in stream networks and watersheds. RHyME2 is 17 a cross-scale statistical and process-based water-quality model. The model ...

  19. Relationship between HBV infection and autoantibodies

    Microsoft Academic Search

    Ming-Huan Zhou; Qiang Ou; De-Ming Tan

    2004-01-01

    AIM: To investigate the relationship between infection of hepatitis B virus (HBV) and development of autoantibodies. METHODS: HBV-DNA and HBVM were tested in 160 serum samples by polymerase chain reaction (PCR) and enzyme- linked immunosorbent assay (ELISA) respectively. Anti- nuclear antibodies (ANA) , an-double strain DNA antibodies. Ads-DNA Ab, thyroglobulin antibody and thyroid microsome antibody (TGA\\/TMA) , rheumatoid factor (RF)

  20. Evaluating the SWAT Model for Hydrological Modeling in the Xixian Watershed and A Comparison with the XAJ Model

    SciTech Connect

    Shi, Peng; Chen, Chao; Srinivasan, Raghavan; Zhang, Xuesong; Cai, Tao; Fang, Xiuqin; Qu, Simin; Chen, Xi; Li, Qiongfang

    2011-09-10

    Already declining water availability in Huaihe River, the 6th largest river in China, is further stressed by climate change and intense human activities. There is a pressing need for a watershed model to better understand the interaction between land use activities and hydrologic processes and to support sustainable water use planning. In this study, we evaluated the performance of SWAT for hydrologic modeling in the Xixian River Basin, located at the headwaters of the Huaihe River, and compared its performance with the Xinanjiang (XAJ) model that has been widely used in China

  1. Can citizen-based observations be assimilated in hydrological models to improve flood prediction?

    NASA Astrophysics Data System (ADS)

    Mazzoleni, Maurizio; Alfonso, Leonardo; Solomatine, Dimitri P.

    2015-04-01

    In the recent years, the continued technological improvement has stimulated the spread of low-cost sensors that can be used to measure hydrological variables by citizens in a more spatially distributed way than classic static physical sensors. However, such measurements have the main characteristics to have irregular arrival time and variable uncertainty. This study presents a Kalman filter based method to integrate citizen-based observations into hydrological models in order to improve flood prediction. The methodology is applied in the Brue catchment, South West of England. In order to estimate the response of the catchment to a given flood event, a lumped conceptual hydrological model is implemented. The measured precipitation values are used as perfect forecast input in the hydrological model. Synthetic streamflow values are used in this study due to the fact that citizen-based observations coming at irregular time steps are not available. The results of this study pointed out how increasing the number of uncertain citizen-based observations within two model time steps can improve the model accuracy leading to a better flood forecast. Therefore, observations uncertainty influences the model accuracy more than the irregular moments in which the streamflow observations are assimilated into the hydrological model. This study is part of the FP7 European Project WeSenseIt Citizen Water Observatory (http://wesenseit.eu/).

  2. Examination of Soil Moisture Retrieval Using SIR-C Radar Data and a Distributed Hydrological Model

    NASA Technical Reports Server (NTRS)

    Hsu, A. Y.; ONeill, P. E.; Wood, E. F.; Zion, M.

    1997-01-01

    A major objective of soil moisture-related hydrological-research during NASA's SIR-C/X-SAR mission was to determine and compare soil moisture patterns within humid watersheds using SAR data, ground-based measurements, and hydrologic modeling. Currently available soil moisture-inversion methods using active microwave data are only accurate when applied to bare and slightly vegetated surfaces. Moreover, as the surface dries down, the number of pixels that can provide estimated soil moisture by these radar inversion methods decreases, leading to less accuracy and, confidence in the retrieved soil moisture fields at the watershed scale. The impact of these errors in microwave- derived soil moisture on hydrological modeling of vegetated watersheds has yet to be addressed. In this study a coupled water and energy balance model operating within a topographic framework is used to predict surface soil moisture for both bare and vegetated areas. In the first model run, the hydrological model is initialized using a standard baseflow approach, while in the second model run, soil moisture values derived from SIR-C radar data are used for initialization. The results, which compare favorably with ground measurements, demonstrate the utility of combining radar-derived surface soil moisture information with basin-scale hydrological modeling.

  3. Benchmarking the WaterGAP3 global hydrology model in reproducing streamflow characteristics

    NASA Astrophysics Data System (ADS)

    Eisner, Stephanie; Flörke, Martina

    2015-04-01

    Global hydrological models are key tools to understand and assess the current state of global freshwater resources. They facilitate quantifying the degree of human interference on the natural hydrological regime and help to assess impacts of global and climate change on water resources. Large to global scale hydrologic simulation is, however, prone to large uncertainties which originate from spatially distributed input data (atmospheric forcing and land surface parameters) and, in particular, the (often) simplified physical process representation. Most large-scale modelling approaches are constrained by the implicit assumption that one single model structure is globally valid and the fact that the modeler lacks location-specific knowledge. In order to evaluate the quality of water availability estimates and to quantify the uncertainty associated with these estimates, it is thus essential to examine systematically where and why large scale hydrological models perform well or poor in reproducing observed streamflow characteristics. This study presents an extensive benchmarking study of the WaterGAP3 (Water - Global Assessment and Prognosis) model to reproduce observed monthly stream characteristics on the basis of more than 2400 observed streamflow records globally. WaterGAP3 is a grid-based conceptual water balance model operating on a 5 arc minute global grid. The model is explicitly designed to account for human interference on the natural hydrologic regime through flow regulation and water abstractions. Monthly simulated discharges for the period 1958-2010 are evaluated against observations based on three complementary performance metrics. Subsequently, model performance is assessed against a set of generic catchment descriptors supported by available global datasets which characterize climatic and physiographic conditions in the individual catchments as well as the degree of human alteration of the hydrologic regime. These relationships between catchment characteristics and model efficiencies help to detect inadequacies in model structure as well as in the underlying input data, thus set the stage for further model development.

  4. Assessing anthropogenic influence on the hydrology of small peri-urban catchments: Development of the object-oriented PUMMA model by integrating urban and rural hydrological models

    NASA Astrophysics Data System (ADS)

    Jankowfsky, S.; Branger, F.; Braud, I.; Rodriguez, F.; Debionne, S.; Viallet, P.

    2014-09-01

    Distributed hydrological models are useful tools for process understanding and water management, especially in peri-urban catchments where the landscape heterogeneity is large, caused by a patchwork of natural and urbanized areas. This paper presents the Peri-Urban Model for landscape MAnagement (PUMMA) built within the LIQUID® modeling framework, specifically designed to study the hydrology of peri-urban catchments. It combines rural and urban hydrological models, and is used for process understanding. The originality of PUMMA is to follow a fully object-oriented approach, for both model mesh building and process representation. Urban areas, represented by cadastral units and rural areas divided in Hydrological Response Units are thus modeled with different interacting process modules. This provides a detailed representation of the runoff generation on natural and impervious areas. Furthermore, the exchange between process modules facilitates the simulation of subsurface and overland flow, as well as groundwater drainage by sewer pipes. Several drainage networks can coexist and interact (e.g. via storm water overflow devices) and water can be stored in retention basins, which allows the modeling of complex suburban drainage systems with multiple outlets. The model is then applied to the Chaudanne catchment (2.7 km2), located in the suburbs of Lyon, France. The uncalibrated model results show the importance of surface runoff from impervious areas for summer events and flow contributions from rural zones for winter events. Furthermore, the model reveals that the retention capacity of the Chaudanne catchment is larger than for classical urban catchments due to the peri-urban character of the catchment.

  5. Satellite remote sensing and hydrologic modeling for flood monitoring in data poor environments

    NASA Astrophysics Data System (ADS)

    Khan, Sadiq Ibrahim

    2011-12-01

    Study of hydroclimatology at a range of temporal scales is important in understanding and ultimately mitigating the potential severe impacts of hydrological extreme events such as floods and droughts. Using daily in-situ data combined with the recently available satellite remote sensing data, the hydroclimatology of Nzoia basin, one of the contributing sub-catchments of Lake Victoria in the East African highlands is analyzed. The basin, with a semi-arid climate, has no sustained base flow contribution to Lake Victoria. The short spell of high discharge showed that rain is the primary cause of floods in the basin. There is only a marginal increase in annual mean discharge over the last 21 years. The 2-, 5- and 10- year peak discharges, for the entire study period showed that more years since the mid 1990s have had high peak discharges despite having relatively less annual rain. The study also presents the hydrologic model calibration and validation results over the Nzoia basin. The spatiotemporal variability of the water cycle components were quantified using a hydrologic model, with in-situ and multi-satellite remote sensing datasets. The model is calibrated using daily observed discharge data for the period between 1985 and 1999, for which model performance is estimated with a Nash Sutcliffe Efficiency (NSCE) of 0.87 and 0.23% bias. The model validation showed an error metrics with NSCE of 0.65 and 1.04% bias. Moreover, the hydrologic capability of satellite precipitation (TRMM-3B42 V6) is evaluated. In terms of reconstruction of the water cycle components the spatial distribution and time series of modeling results for precipitation and runoff showed considerable agreement with the monthly model runoff estimates and gauge observations. Runoff values responded to precipitation events that occurred across the catchment during the wet season from March to early June.The spatially distributed model inputs, states, and outputs, were found to be useful for understanding the hydrologic behavior at the catchment scale. The monthly peak runoff is observed in the months of April, May and November. The analysis revealed a linear relationship between rainfall and runoff for both wet and dry seasons. Satellite precipitation forcing data showed the potential to be used not only for the investigation of water balance but also for addressing issues pertaining to sustainability of the resources at the catchment scale. Implementation of a flood prediction system can potentially help mitigate flood induced hazards. Such a system typically requires implementation and calibration of a hydrologic model using in-situ observations (e.g. rain gauges and stream gauges). Recently, satellite remote sensing data has emerged as a viable alternative or supplement to the in-situ observations due to its availability over vast ungauged regions. The focus of this study is to integrate the best available satellite products within a semi-distributed hydrologic model to characterize the spatial extent of flooding over sparsely-gauged or ungauged basins. A satellite remote sensing based approach is proposed to calibrate a hydrologic model, simulate the spatial extent of flooding, and evaluate the probability of detecting inundated areas. A raster-based semi-distributed hydrologic model, CREST, is implemented for the Nzoia basin, a sub-basin of Lake Victoria in Africa. MODIS Terra and ASTER-based raster flood inundation maps were produced over the region and used to benchmark the hydrologic model simulations of inundated areas. The analysis showed the value of integrating satellite data such as precipitation, land cover type, topography and other data products along with space based flood inundation extents as inputs for the hydrologic model. It is concluded that the quantification of flooding spatial extent through optical sensors can help to evaluate hydrologic models and hence potentially improve hydrologic prediction and flood management strategies in ungauged catchments.

  6. Intercomparison and suitability of five Greenland topographic datasets for the purpose of hydrologic runoff modeling

    NASA Astrophysics Data System (ADS)

    Pitcher, L. H.; Smith, L. C.; Rennermalm, A. K.; Chu, V. W.; Gleason, C. J.; Yang, K.; Finnegan, D. C.; LeWinter, A. L.; Moller, D.; Moustafa, S.

    2012-12-01

    Rapid melting of the Greenland Ice Sheet (GrIS) and subsequent sea level rise has underscored the need for accurate modeling of hydrologic processes. Researchers rely on the accuracy of topography datasets for this purpose, especially in remote areas like Greenland where in situ validation data are difficult to acquire. A number of new remotely-sensed Digital Elevation Models (DEMs) have recently become available for Greenland, but a comparative study of their respective quality and suitability for hydrologic modeling has not been undertaken. We examine five such remotely-sensed DEMs acquired for proglacial and supraglacial ablation zones of Greenland, namely (1) WorldView stereo DEMs, (2) NASA GLISTIN-A experimental radar, (3) NASA/IceBridge Airborne Topographic Mapper (ATM), (4) Greenland Ice Mapping Project (GIMP) DEM, and (5) ASTER DEM. The quality, strengths and weaknesses of these DEMs for GrIS hydrologic modeling is assessed through intercomparison and in situ terrestrial lidar scanning data with precise RTK GPS control. Additionally, gridded bedrock (i.e. NASA/IceBridge Multichannel Coherent Radar Depth Sounder (MCoRDS); Bamber DEMs) and surface topography datasets are combined to create a hydraulic potentiometric surface for hydrologic modeling. Finally, the suitability of these combined topographic products for hydrologic modeling, characterization of GrIS meltwater runoff, and estimating sub- and/or englacial pathways is explored.

  7. In Lieu of the Paired-Catchment Approach - Hydrologic Model Change Detection at the Catchment Scale

    NASA Astrophysics Data System (ADS)

    Zegre, N. P.

    2009-05-01

    Knowledge of the effects of forest management on hydrology primarily comes from paired-catchment studies conducted world-wide. While this approach has been useful for discerning changes in small experimental catchments and has contributed fundamental knowledge of the effects of forest and natural resources management on hydrology, results from experimental catchment studies exhibit temporal variability, have limited spatial inference, and lack insight into internal catchment processes. To address these limitations, traditional field experiments can be supplemented with numerical models to isolate the effects of disturbance on catchment behavior. Outlined in this study is an alternative method of change detection for daily time-series streamflow that integrates hydrologic modeling and statistical change detection methods used to discern the effects of contemporary forest management on the hydrology of western Oregon Cascades headwater catchments. In this study, a simple rainfall-runoff model was used to generate virtual reference catchments using attributes that reflect streamflow conditions absent of forest disturbance. Streamflow was simulated under three levels of model uncertainty using GLUE and were used to construct generalized least squares regression models to discern changes in hydrologic behavior. By considering processes within a single experimental catchment rather than the two spatially explicit catchments used in traditional paired experiments, it was possible to reduce unexplained variation and increase the likelihood of correctly detecting hydrologic effects following forest harvesting. In order to evaluate the stability of the hydrologic and statistical models and catchment behavior over time, the change detection method was applied to a contemporary reference catchment. By applying the change detection model to reference catchments, it was possible to eliminate unexpected variation as a cause for detected changes in observed hydrology. Further, it was possible to attribute increased streamflow to forest management with greater certainty. Shown is the importance and necessity of coupling hydrologic modeling studies with reference catchments in order to evaluate model performance and reduce false detections from statistical models. The proposed method appears to be a useful alternative to change detection using highly variable daily streamflow.

  8. HBV vaccine efficacy and detection and genotyping of vaccineé asymptomatic breakthrough HBV infection in Egypt

    PubMed Central

    Abushady, Eman AE; Gameel, Magda MA; Klena, John D; Ahmed, Salwa F; Abdel-Wahab, Kouka SE; Fahmy, Sanya M

    2011-01-01

    AIM: To evaluate the impact of mass vaccination against the hepatitis B virus (HBV) in Egypt, and to search for vaccinee asymptomatic breakthrough HBV infection and its genotype. METHODS: Seven hundred serum samples from vaccinated children and adults (aged 2-47 years) were used for quantitative and qualitative detection of HBsAb by ELISA. Three hundred and sixty serum samples representing undetectable or low or high HBsAb were screened for markers of active HBV infection (HBsAg, HBcAb (IgG) and HBeAb by ELISA, plus HBsAg by AxSYM) and HBV-DNA genotyping by nested multiplex PCR and by DNA sequencing. RESULTS: It was found that 65% of children aged 2-4 years, and 20.5% aged 4-13 years, as well as 45% adults were good responders to HBV vaccination mounting protective level HBsAb. Poor responders were 28%, 59.5% and 34%, and non-responders were 7%, 20% and 21% respectively, in the three studied groups. Markers of asymptomatic HBV infections were HBsAg detected by ELISA in 2.5% vs 11.39% by AxSYM. Other markers were HBcAb (IgG) in 1.38%, HBeAb in 0.83%, and HBV-DNA in 7.8%. All had HBV genotype E infection. CONCLUSION: It is concluded that HBV vaccine is efficient in controlling HBV infection among children and adults. The vaccine breakthrough infection was by HBV genotype E. A booster dose of vaccine is recommended, probably four years after initial vaccination. PMID:21860674

  9. Evaluating and improving CLM hydrologic processes for integrated earth system modeling at regional scales

    Microsoft Academic Search

    M. Huang; L. Leung; M. S. Wigmosta; A. M. Coleman; Y. Ke; T. K. Tesfa; H. Li

    2010-01-01

    The community land model (CLM) was designed for coupling with atmospheric models to simulate water, energy, and carbon fluxes between the land surface and atmosphere. These fluxes are regulated in various degrees by its hydrologic processes, which have not been vigorously evaluated for applications at watershed or regional scales. In the framework of an integrated regional earth system model being

  10. Spiking modular neural networks: A neural network modeling approach for hydrological processes

    Microsoft Academic Search

    Kamban Parasuraman; Amin Elshorbagy; Sean K. Carey

    2006-01-01

    Artificial Neural Networks (ANNs) have been widely used for modeling hydrological processes that are embedded with high nonlinearity in both spatial and temporal scales. The input-output functional relationship does not remain the same over the entire modeling domain, varying at different spatial and temporal scales. In this study, a novel neural network model called the spiking modular neural networks (SMNNs)

  11. THE APPLICATION OF HYDROLOGICAL MODELS IN MAGS: LESSONS LEARNED FOR PUB

    Microsoft Academic Search

    K. R. Snelgrove; E. D. Soulis; F. R. Seglenieks; N. Kouwen; A. Pietroniro

    Significant progress has been achieved in the creation of modelling tools that describe hydrological processes within northern landscapes as a result of the Mackenzie GEWEX study (MAGS). Continuous simulations using WATFLOOD and WatCLASS represent Level 0 and Level 2 results within the MAGS modelling strategy. Models and data sets from MAGS represent a starting point for more detailed process studies

  12. Streamflow Estimation from Hydrologic Model Assimilation of Remotely Sensed Snow Information in Snowmelt Dominated Basins

    Microsoft Academic Search

    K. A. Dressler; G. Leavesley; R. Bales; S. Fassnacht

    2004-01-01

    The USGS Precipitation Runoff Modeling System (PRMS) hydrological model was used to evaluate the utility of experimental, gridded, 1-km2 snow covered area (SCA) and snow water equivalent (SWE) products in improving the modeling of snowmelt runoff from three headwater basins in the Southwestern United Sates. The SCA product was the fraction of each 1-km2 pixel covered by snow and was

  13. Soil hydrological properties regulate grassland ecosystem responses to multifactor global change: A modeling analysis

    Microsoft Academic Search

    Ensheng Weng; Yiqi Luo

    2008-01-01

    We conducted a modeling study to evaluate how soil hydrological properties regulate water and carbon dynamics of grassland ecosystems in response to multifactor global change. We first calibrated a process-based terrestrial ecosystem (TECO) model against data from two experiments with warming and clipping or doubled precipitation in Great Plains. The calibrated model was used to simulate responses of soil moisture,

  14. Improvements to the Community Land Model and their impact on the hydrological cycle

    Microsoft Academic Search

    K. W. Oleson; G.-Y. Niu; Z.-L. Yang; D. M. Lawrence; P. E. Thornton; P. J. Lawrence; R. Stöckli; R. E. Dickinson; G. B. Bonan; S. Levis; A. Dai; T. Qian

    2008-01-01

    The Community Land Model version 3 (CLM3) is the land component of the Community Climate System Model (CCSM). CLM3 has energy and water biases resulting from deficiencies in some of its canopy and soil parameterizations related to hydrological processes. Recent research by the community that utilizes CLM3 and the family of CCSM models has indicated several promising approaches to alleviating

  15. Parameterisation and scaling of the land surface model for use in a coupled climate-hydrological model

    NASA Astrophysics Data System (ADS)

    Rasmussen, S. H.; Butts, M. B.; Lerer, S. M.; Refsgaard, J. C.

    2012-03-01

    SummaryClimate impact studies in hydrology have traditionally neglected the land-atmosphere feedback. Hydrological models are forced with output from climate models but neglecting this feedback may lead to an inaccurate estimation of evapotranspiration (ET). Two-way coupling of a hydrological model and a climate model can overcome this problem by linking the two models through a shared land-atmosphere process description. In this study we analyse the hydrological model MIKE SHE using a two-layer energy-based ET model for use in a coupling with a regional climate model (RCM). The value of coupling to MIKE SHE is that it makes it possible to include lateral transport of surface water and groundwater not generally treated in RCM's and to represent human interventions like groundwater pumping, irrigation schemes, etc. for adaptation studies. The hydrological model is applied to the FIFE site to investigate the effects of model resolution and parameter scales. The area of interest corresponds to a RCM grid cell. The hydrological model is parameterized with effective parameters assessed directly from field data at the site and literature. Using only these observed data and literature estimates to parameterise the model, it is able to reproduce the observed ET, sensible heat flux and to some extent surface soil moisture content; over a whole growing season. Hydrological simulations carried out over a range of spatial grids from 240 m to 15 km show that, for this case, the areal average ET appears to be insensitive to model resolution. The model is able to reproduce some of the spatial variability within the area, but not the exact pattern. By running the hydrological model at the highest resolution with uniform atmospheric input we examined the effect of using coarser resolution climate forcing, for example from a RCM. The areal mean ET and soil moisture (SM) temporal variations are reproduced quite well, but the spatial variability in the hydrological response is substantially underestimated; mainly because of the uniform precipitation. Our results are therefore encouraging for using this type of energy-based model in a coupling between a regional climate model and a distributed hydrological model. As the FIFE area is a relatively homogeneous site, additional tests are needed at heterogeneous sites to validate whether our findings are in general valid.

  16. Developing geoprocessing services for a hydrological model application

    Microsoft Academic Search

    C. Granell; L. Díaz; M. Gould; V. Pascual; J. Guimet; P. Carrara; M. Pepe

    Spatial data infrastructures support the most common requirements of spatial in- formation users -discovery, access, and visual overlay of datasets- however specialized users such as hydrological scientists require more advanced services for capturing, analyzing and processing huge volumes of data. To shift from locally-processed complex tasks to on-line, dis- tributed service-data offers, we present a web-based prototype using distributed geoprocessing

  17. Models as multiple working hypotheses: Hydrological simulation of neotropical alpine wetlands

    NASA Astrophysics Data System (ADS)

    Buytaert, Wouter; Beven, Keith

    2010-05-01

    Tropical alpine grasslands, locally known as páramos, are the water towers of the northern Andes. They are an essential water source for drinking water, irrigation schemes and hydropower plants. But despite their high socio-economic relevance, their hydrological processes are very poorly understood. Since environmental change, ranging from small scale land-use changes to global climate change, is expected to have a strong impact on the hydrological behaviour, a better understanding and hydrological prediction is urgently needed. In this study, we apply a set of nine hydrological models of different complexity to a small, well monitored upland catchment in the Ecuadorian Andes. The models represent different hypotheses on the hydrological functioning of the páramo ecosystem at catchment scale. Interpretation of the results of the model prediction and uncertainty analysis of the model parameters reveals important insights in the evapotranspiration, surface runoff generation and base flow in the páramo. However, problems with boundary conditions, particularly spatial variability of precipitation, pose serious constraints on the differentiation between model representations.

  18. Assessing the importance of rainfall uncertainty on hydrological models with different spatial and temporal scale

    NASA Astrophysics Data System (ADS)

    Nossent, Jiri; Pereira, Fernando; Bauwens, Willy

    2015-04-01

    Precipitation is one of the key inputs for hydrological models. As long as the values of the hydrological model parameters are fixed, a variation of the rainfall input is expected to induce a change in the model output. Given the increased awareness of uncertainty on rainfall records, it becomes more important to understand the impact of this input - output dynamic. Yet, modellers often still have the intention to mimic the observed flow, whatever the deviation of the employed records from the actual rainfall might be, by recklessly adapting the model parameter values. But is it actually possible to vary the model parameter values in such a way that a certain (observed) model output can be generated based on inaccurate rainfall inputs? Thus, how important is the rainfall uncertainty for the model output with respect to the model parameter importance? To address this question, we apply the Sobol' sensitivity analysis method to assess and compare the importance of the rainfall uncertainty and the model parameters on the output of the hydrological model. In order to be able to treat the regular model parameters and input uncertainty in the same way, and to allow a comparison of their influence, a possible approach is to represent the rainfall uncertainty by a parameter. To tackle the latter issue, we apply so called rainfall multipliers on hydrological independent storm events, as a probabilistic parameter representation of the possible rainfall variation. As available rainfall records are very often point measurements at a discrete time step (hourly, daily, monthly,…), they contain uncertainty due to a latent lack of spatial and temporal variability. The influence of the latter variability can also be different for hydrological models with different spatial and temporal scale. Therefore, we perform the sensitivity analyses on a semi-distributed model (SWAT) and a lumped model (NAM). The assessment and comparison of the importance of the rainfall uncertainty and the model parameters is achieved by considering different scenarios for the included parameters and the state of the models.

  19. How do wetland type and location affect their hydrological services? - A distributed hydrological modelling study of the contribution of isolated and riparian wetlands

    NASA Astrophysics Data System (ADS)

    Fossey, Maxime; Rousseau, Alain N.; Savary, Stéphane; Royer, Alain

    2015-04-01

    Wetlands play a significant role on the hydrological cycle, reducing peak flows through water storage functions and sustaining low flows through slow release of water. However, their impacts on water resource availability and flood control are mainly driven by wetland types and locations within a watershed. So, despite the general agreement about these major hydrological functions, little is known about their spatial and typological influences. Consequently, assessing the quantitative impact of wetlands on hydrological regimes has become a relevant issue for both the scientific community and the decision-maker community. To investigate the hydrologic response at the watershed scale, mathematical modelling has been a well-accepted framework. Specific isolated and riparian wetland modules were implemented in the PHYSITEL/HYDROTEL distributed hydrological modelling platform to assess the impact of the spatial distribution of isolated and riparian wetlands on the stream flows of the Becancour River watershed, Quebec, Canada. More specifically, the focus was on assessing whether stream flow parameters, including peak flow and low flow, were related to: (i) geographic location of wetlands, (ii) typology of wetlands, and (iii) season of the year. Preliminary results suggest that isolated and riparian wetlands have individual space- and time-dependent impacts on the hydrologic response of the study watershed and provide relevant information for the design of wetland protection and restoration programs.

  20. Using the cloud to speed-up calibration of watershed-scale hydrologic models (Invited)

    NASA Astrophysics Data System (ADS)

    Goodall, J. L.; Ercan, M. B.; Castronova, A. M.; Humphrey, M.; Beekwilder, N.; Steele, J.; Kim, I.

    2013-12-01

    This research focuses on using the cloud to address computational challenges associated with hydrologic modeling. One example is calibration of a watershed-scale hydrologic model, which can take days of execution time on typical computers. While parallel algorithms for model calibration exist and some researchers have used multi-core computers or clusters to run these algorithms, these solutions do not fully address the challenge because (i) calibration can still be too time consuming even on multicore personal computers and (ii) few in the community have the time and expertise needed to manage a compute cluster. Given this, another option for addressing this challenge that we are exploring through this work is the use of the cloud for speeding-up calibration of watershed-scale hydrologic models. The cloud used in this capacity provides a means for renting a specific number and type of machines for only the time needed to perform a calibration model run. The cloud allows one to precisely balance the duration of the calibration with the financial costs so that, if the budget allows, the calibration can be performed more quickly by renting more machines. Focusing specifically on the SWAT hydrologic model and a parallel version of the DDS calibration algorithm, we show significant speed-up time across a range of watershed sizes using up to 256 cores to perform a model calibration. The tool provides a simple web-based user interface and the ability to monitor the calibration job submission process during the calibration process. Finally this talk concludes with initial work to leverage the cloud for other tasks associated with hydrologic modeling including tasks related to preparing inputs for constructing place-based hydrologic models.

  1. Assessment of Required Accuracy of Digital Elevation Data for Hydrologic Modeling

    NASA Technical Reports Server (NTRS)

    Kenward, T.; Lettenmaier, D. P.

    1997-01-01

    The effect of vertical accuracy of Digital Elevation Models (DEMs) on hydrologic models is evaluated by comparing three DEMs and resulting hydrologic model predictions applied to a 7.2 sq km USDA - ARS watershed at Mahantango Creek, PA. The high resolution (5 m) DEM was resempled to a 30 m resolution using method that constrained the spatial structure of the elevations to be comparable with the USGS and SIR-C DEMs. This resulting 30 m DEM was used as the reference product for subsequent comparisons. Spatial fields of directly derived quantities, such as elevation differences, slope, and contributing area, were compared to the reference product, as were hydrologic model output fields derived using each of the three DEMs at the common 30 m spatial resolution.

  2. Evaluating and improving hydrologic processes in the community land model for integrated earth system modeling

    NASA Astrophysics Data System (ADS)

    Hannah, D. M.; Khamis, K.; Blaen, P. J.; Hainie, S.; Mellor, C.; Brown, L. E.; Milner, A. M.

    2011-12-01

    High climatic sensitivity and low anthropogenic influence make glacierized river basins important environments for examining hydrological and ecological response to global change. This paper synthesises findings from previous and ongoing research in glacierized Alpine and Arctic river basins (located in the French Pyrenees, New Zealand, Swedish Lapland and Svalbard), which adopts an interdisciplinary approach to investigate the climate-cryosphere-hydrology-ecology cascade. Data are used to advance hypotheses concerning the consequences of climate change/ variability on glacier river system hydrology and ecology. Aquatic ecosystems in high latitude and altitude environments are influenced strongly by cryospheric and hydrological processes due to links between atmospheric forcing, snowpack/ glacier mass-balance, river runoff, physico-chemistry and biota. In the current phase of global warming, many glaciers are retreating. Using downscaled regional climate projections as inputs to a distributed hydrological model for a study basin in the French Pyrenees (i.e. an environment at the contemporary limit of valley glaciation), we show how shrinking snow and ice-masses may alter space-time dynamics in basin runoff. Notably, the timing of peak snow- and ice-melt may shift; and the proportion of stream flow sourced from rainfall-runoff (cf. meltwater) may increase. Across our range of Alpine and Arctic study basins, we quantify observed links between relative water source contributions (% meltwater : % groundwater), physico-chemical habitat (e.g. water temperature, electrical conductivity, suspended sediment and channel stability) and benthic communities. At the site scale, results point towards increased community diversity (taxonomic and functional) as meltwater contributions decline and physico-chemical habitat becomes less harsh. However, basin-scale biodiversity may be reduced due to less spatio-temporal heterogeneity in water source contributions and habitats, and the extinction of cold stenothermic specialists. Similar integrated, long-term research into hydroecological connections in other glacierized river basins is vital: (1) to enable robust projections of stream hydrology (water source contributions and physico-chemical habitat) and ecological response under scenarios of future climate/ variability, and (2) to develop conservation strategies for these fragile Alpine and Arctic freshwater ecosystems.

  3. The use of distributed hydrological models for the Gard 2002 flash flood event: Analysis of associated hydrological processes

    NASA Astrophysics Data System (ADS)

    Braud, Isabelle; Roux, Hélène; Anquetin, Sandrine; Maubourguet, Marie-Madeleine; Manus, Claire; Viallet, Pierre; Dartus, Denis

    2010-11-01

    SummaryThis paper presents a detailed analysis of the September 8-9, 2002 flash flood event in the Gard region (southern France) using two distributed hydrological models: CVN built within the LIQUID® hydrological platform and MARINE. The models differ in terms of spatial discretization, infiltration and water redistribution representation, and river flow transfer. MARINE can also account for subsurface lateral flow. Both models are set up using the same available information, namely a DEM and a pedology map. They are forced with high resolution radar rainfall data over a set of 18 sub-catchments ranging from 2.5 to 99 km2 and are run without calibration. To begin with, models simulations are assessed against post field estimates of the time of peak and the maximum peak discharge showing a fair agreement for both models. The results are then discussed in terms of flow dynamics, runoff coefficients and soil saturation dynamics. The contribution of the subsurface lateral flow is also quantified using the MARINE model. This analysis highlights that rainfall remains the first controlling factor of flash flood dynamics. High rainfall peak intensities are very influential of the maximum peak discharge for both models, but especially for the CVN model which has a simplified overland flow transfer. The river bed roughness also influences the peak intensity and time. Soil spatial representation is shown to have a significant role on runoff coefficients and on the spatial variability of saturation dynamics. Simulated soil saturation is found to be strongly related with soil depth and initial storage deficit maps, due to a full saturation of most of the area at the end of the event. When activated, the signature of subsurface lateral flow is also visible in the spatial patterns of soil saturation with higher values concentrating along the river network. However, the data currently available do not allow the assessment of both patterns. The paper concludes with a set of recommendations for enhancing field observations in order to progress in process understanding and gather a larger set of data to improve the realism of distributed models.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  5. The role of innate immunity in HBV infection.

    PubMed

    Han, Qiuju; Zhang, Cai; Zhang, Jian; Tian, Zhigang

    2013-01-01

    Hepatitis B virus (HBV) infection is one of the main causes of chronic liver diseases. Whether HBV infection is cleared or persists is determined by both viral factors and host immune responses. It becomes clear that innate immunity is of importance in protecting the host from HBV infection and persistence. However, HBV develops strategies to suppress the antiviral immune responses. A combined therapeutic strategy with both viral suppression and enhancement of antiviral immune responses is needed for effective long-term clearance and cure for chronic HBV infection. We and others confirmed that bifunctional siRNAs with both gene silencing and innate immune activation properties are beneficial for inhibition of HBV and represent a potential approach for treatment of viral infection. Understanding the nature of liver innate immunity and their roles in chronic HBV progression and HBV clearance may aid in the design of novel therapeutic strategies for chronic HBV infection. PMID:22814721

  6. Towards a regional climate model coupled to a comprehensive hydrological model

    NASA Astrophysics Data System (ADS)

    Rasmussen, S. H.; Drews, M.; Christensen, J. H.; Butts, M. B.; Jensen, K. H.; Refsgaard, J.; Hydrological ModellingAssessing Climate Change Impacts At Different Scales (Hyacints)

    2010-12-01

    When planing new ground water abstractions wells, building areas, roads or other land use activities information about expected future groundwater table location for the lifetime of the construction may be critical. The life time of an abstraction well can be expected to be more than 50 years, while if for buildings may be up to 100 years or more. The construction of an abstraction well is expensive and it is important to know if clean groundwater is available for its expected life time. The future groundwater table is depending on the future climate. With climate change the hydrology is expected to change as well. Traditionally, this assessment has been done by driving hydrological models with output from a climate model. In this way feedback between the groundwater hydrology and the climate is neglected. Neglecting this feedback can lead to imprecise or wrong results. The goal of this work is to couple the regional climate model HIRHAM (Christensen et al. 2006) to the hydrological model MIKE SHE (Graham and Butts, 2006). The coupling exploits the new OpenMI technology that provides a standardized interface to define, describe and transfer data on a time step basis between software components that run simultaneously (Gregersen et al., 2007). HIRHAM runs on a UNIX platform whereas MIKE SHE and OpenMI are under WINDOWS. Therefore the first critical task has been to develop an effective communication link between the platforms. The first step towards assessing the coupled models performance are addressed by looking at simulated land-surface atmosphere feedback through variables such as evapotranspiration, sensible heat flux and soil moisture content. Christensen, O.B., Drews, M., Christensen, J.H., Dethloff, K., Ketelsen, K., Hebestadt, I. and Rinke, A. (2006) The HIRHAM Regional Climate Model. Version 5; DMI Scientific Report 0617. Danish Meteorological Institute. Graham, D.N. and Butts, M.B. (2005) Flexible, integrated watershed modelling with MIKE SHE, In Watershed Models, (Eds. V.P. Singh & D.K. Frevert) CRC Press. Pages 245-272, ISBN: 0849336090. Gregersen, J.B., Gijsbers, P.J.A. and Westen, S.J.P. (2007) OpenMI: Open modelling interface. Journal of Hydroinformatics, 09.3, 175191. doi: 10.2166/hydro.2007.023.

  7. The Significance of Hydrologic Model Selection in studying Climate Change Impacts on Low Flows

    Microsoft Academic Search

    L. D. Brekke; E. P. Maurer

    2006-01-01

    Two hydrologic models were used to study climate change runoff impacts in California's Central Valley. One model is a state-of-the-art, uncalibrated land surface model (Variable Infiltration Capacity model) while the other is an operational, calibrated rainfall-runoff model (NOAA\\/NWS Sacramento Soil Moisture Accounting model). The focus of the analysis was to assess how simulated changes in climatological monthly runoff differ with

  8. Evaluation of Potential Evapotranspiration from a Hydrologic Model on a National Scale

    NASA Astrophysics Data System (ADS)

    Hakala, Kirsti; Markstrom, Steven; Hay, Lauren

    2015-04-01

    The U.S. Geological Survey has developed a National Hydrologic Model (NHM) to support coordinated, comprehensive and consistent hydrologic model development and facilitate the application of simulations on the scale of the continental U.S. The NHM has a consistent geospatial fabric for modeling, consisting of over 100,000 hydrologic response units HRUs). Each HRU requires accurate parameter estimates, some of which are attained from automated calibration. However, improved calibration can be achieved by initially utilizing as many parameters as possible from national data sets. This presentation investigates the effectiveness of calculating potential evapotranspiration (PET) parameters based on mean monthly values from the NOAA PET Atlas. Additional PET products are then used to evaluate the PET parameters. Effectively utilizing existing national-scale data sets can simplify the effort in establishing a robust NHM.

  9. Reducing hydrologic model uncertainty in monthly streamflow predictions using multimodel combination

    NASA Astrophysics Data System (ADS)

    Li, Weihua; Sankarasubramanian, A.

    2012-12-01

    Model errors are inevitable in any prediction exercise. One approach that is currently gaining attention in reducing model errors is by combining multiple models to develop improved predictions. The rationale behind this approach primarily lies on the premise that optimal weights could be derived for each model so that the developed multimodel predictions will result in improved predictions. A new dynamic approach (MM-1) to combine multiple hydrological models by evaluating their performance/skill contingent on the predictor state is proposed. We combine two hydrological models, "abcd" model and variable infiltration capacity (VIC) model, to develop multimodel streamflow predictions. To quantify precisely under what conditions the multimodel combination results in improved predictions, we compare multimodel scheme MM-1 with optimal model combination scheme (MM-O) by employing them in predicting the streamflow generated from a known hydrologic model (abcd model orVICmodel) with heteroscedastic error variance as well as from a hydrologic model that exhibits different structure than that of the candidate models (i.e., "abcd" model or VIC model). Results from the study show that streamflow estimated from single models performed better than multimodels under almost no measurement error. However, under increased measurement errors and model structural misspecification, both multimodel schemes (MM-1 and MM-O) consistently performed better than the single model prediction. Overall, MM-1 performs better than MM-O in predicting the monthly flow values as well as in predicting extreme monthly flows. Comparison of the weights obtained from each candidate model reveals that as measurement errors increase, MM-1 assigns weights equally for all the models, whereas MM-O assigns higher weights for always the best-performing candidate model under the calibration period. Applying the multimodel algorithms for predicting streamflows over four different sites revealed that MM-1 performs better than all single models and optimal model combination scheme, MM-O, in predicting the monthly flows as well as the flows during wetter months.

  10. The implementation and validation of improved landsurface hydrology in an atmospheric general circulation model

    NASA Technical Reports Server (NTRS)

    Johnson, Kevin D.; Entekhabi, Dara; Eagleson, Peter S.

    1991-01-01

    Landsurface hydrological parameterizations are implemented in the NASA Goddard Institute for Space Studies (GISS) General Circulation Model (GCM). These parameterizations are: (1) runoff and evapotranspiration functions that include the effects of subgrid scale spatial variability and use physically based equations of hydrologic flux at the soil surface, and (2) a realistic soil moisture diffusion scheme for the movement of water in the soil column. A one dimensional climate model with a complete hydrologic cycle is used to screen the basic sensitivities of the hydrological parameterizations before implementation into the full three dimensional GCM. Results of the final simulation with the GISS GCM and the new landsurface hydrology indicate that the runoff rate, especially in the tropics is significantly improved. As a result, the remaining components of the heat and moisture balance show comparable improvements when compared to observations. The validation of model results is carried from the large global (ocean and landsurface) scale, to the zonal, continental, and finally the finer river basin scales.

  11. Digital Hydrologic Networks Supporting Applications Related to Spatially Referenced Regression Modeling

    USGS Publications Warehouse

    Brakebill, J.W.; Wolock, D.M.; Terziotti, S.E.

    2011-01-01

    Digital hydrologic networks depicting surface-water pathways and their associated drainage catchments provide a key component to hydrologic analysis and modeling. Collectively, they form common spatial units that can be used to frame the descriptions of aquatic and watershed processes. In addition, they provide the ability to simulate and route the movement of water and associated constituents throughout the landscape. Digital hydrologic networks have evolved from derivatives of mapping products to detailed, interconnected, spatially referenced networks of water pathways, drainage areas, and stream and watershed characteristics. These properties are important because they enhance the ability to spatially evaluate factors that affect the sources and transport of water-quality constituents at various scales. SPAtially Referenced Regressions On Watershed attributes (SPARROW), a process-based/statistical model, relies on a digital hydrologic network in order to establish relations between quantities of monitored contaminant flux, contaminant sources, and the associated physical characteristics affecting contaminant transport. Digital hydrologic networks modified from the River Reach File (RF1) and National Hydrography Dataset (NHD) geospatial datasets provided frameworks for SPARROW in six regions of the conterminous United States. In addition, characteristics of the modified RF1 were used to update estimates of mean-annual streamflow. This produced more current flow estimates for use in SPARROW modeling. ?? 2011 American Water Resources Association. This article is a U.S. Government work and is in the public domain in the USA.

  12. Digital Hydrologic Networks Supporting Applications Related to Spatially Referenced Regression Modeling1

    PubMed Central

    Brakebill, JW; Wolock, DM; Terziotti, SE

    2011-01-01

    Abstract Digital hydrologic networks depicting surface-water pathways and their associated drainage catchments provide a key component to hydrologic analysis and modeling. Collectively, they form common spatial units that can be used to frame the descriptions of aquatic and watershed processes. In addition, they provide the ability to simulate and route the movement of water and associated constituents throughout the landscape. Digital hydrologic networks have evolved from derivatives of mapping products to detailed, interconnected, spatially referenced networks of water pathways, drainage areas, and stream and watershed characteristics. These properties are important because they enhance the ability to spatially evaluate factors that affect the sources and transport of water-quality constituents at various scales. SPAtially Referenced Regressions On Watershed attributes (SPARROW), a process-based/statistical model, relies on a digital hydrologic network in order to establish relations between quantities of monitored contaminant flux, contaminant sources, and the associated physical characteristics affecting contaminant transport. Digital hydrologic networks modified from the River Reach File (RF1) and National Hydrography Dataset (NHD) geospatial datasets provided frameworks for SPARROW in six regions of the conterminous United States. In addition, characteristics of the modified RF1 were used to update estimates of mean-annual streamflow. This produced more current flow estimates for use in SPARROW modeling. PMID:22457575

  13. Digital Hydrologic Networks Supporting Applications Related to Spatially Referenced Regression Modeling.

    PubMed

    Brakebill, Jw; Wolock, Dm; Terziotti, Se

    2011-10-01

    Digital hydrologic networks depicting surface-water pathways and their associated drainage catchments provide a key component to hydrologic analysis and modeling. Collectively, they form common spatial units that can be used to frame the descriptions of aquatic and watershed processes. In addition, they provide the ability to simulate and route the movement of water and associated constituents throughout the landscape. Digital hydrologic networks have evolved from derivatives of mapping products to detailed, interconnected, spatially referenced networks of water pathways, drainage areas, and stream and watershed characteristics. These properties are important because they enhance the ability to spatially evaluate factors that affect the sources and transport of water-quality constituents at various scales. SPAtially Referenced Regressions On Watershed attributes (SPARROW), a process-based/statistical model, relies on a digital hydrologic network in order to establish relations between quantities of monitored contaminant flux, contaminant sources, and the associated physical characteristics affecting contaminant transport. Digital hydrologic networks modified from the River Reach File (RF1) and National Hydrography Dataset (NHD) geospatial datasets provided frameworks for SPARROW in six regions of the conterminous United States. In addition, characteristics of the modified RF1 were used to update estimates of mean-annual streamflow. This produced more current flow estimates for use in SPARROW modeling. PMID:22457575

  14. Large-scale hydrological model prediction uncertainties estimated from an ensemble of hydrostratigraphic models based on resistivity and borehole data

    NASA Astrophysics Data System (ADS)

    Marker, P. A.; Ferré, T. P. A.; Foged, N.; Christiansen, A. V.; Auken, E.; Mosegaard, K.; Bauer-Gottwein, P.

    2014-12-01

    Large-scale hydrological models are important tools for water resources management. Model predictions are used in agricultural, contamination, water scarcity, and groundwater depletion applications and for well-field management. The predictions, used for management and practical decision-making, are sensitive to variations in hydrostratigraphy, thus uncertainty can be addressed by sampling the structural model space. Hydrostratigraphic input to large-scale hydrologic models is commonly based on one-truth geologic models. High resolution airborne electromagnetic (AEM) data with extensive spatial coverage are valuable for use in hydrostratigraphic modeling. In particular, geological structures and within-unit heterogeneity, which are poorly identified with spatially scarce borehole lithology data, are well resolved by AEM data. The challenge is to combine geophysical and hydrological information in a common parameter space. We propose to estimate hydrological model prediction uncertainties using an ensemble of resistivity and borehole based hydrostratigraphic models. Single hydrostratigraphic models are created using a semi-automatic sequential hydrogeophysical inversion method, which integrates AEM and borehole data. A spatially variable translator function converts electrical resistivities obtained from geophysical inversion into clay fractions through correlation with borehole lithological observations. The subsurface domain is divided into zones by k-means clustering on the inferred clay fractions and electrical resistivities. Hydraulic conductivities of the zones are estimated through hydrological model calibration using head and discharge observations. An ensemble of behavioral hydrostratigraphic models is sampled based on a threshold value of the objective function of the clustering algorithm, and goodness of fit to hydrological data. Hydrological predictions are capture zones and drawdown responses to pumping in areas of interest for management. Results will be shown for a Danish case study.

  15. GIS/RS-based Integrated Eco-hydrologic Modeling in the East River Basin, South China

    NASA Astrophysics Data System (ADS)

    Wang, Kai

    Land use/cover change (LUCC) has significantly altered the hydrologic system in the East River (Dongjiang) Basin. Quantitative modeling of hydrologic impacts of LUCC is of great importance for water supply, drought monitoring and integrated water resources management. An integrated eco-hydrologic modeling system of Distributed Monthly Water Balance Model (DMWBM), Surface Energy Balance System (SEBS) was developed with aid of GIS/RS to quantify LUCC, to conduct physically-based ET (evapotranspiration) mapping and to predict hydrologic impacts of LUCC. To begin with, in order to evaluate LUCC, understand implications of LUCC and provide boundary condition for the integrated eco-hydrologic modeling, firstly the long-term vegetation dynamics was investigated based on Normalized Difference Vegetation Index (NDVI) data, and then LUCC was analyzed with post-classification methods and finally LUCC prediction was conducted based on Markov chain model. The results demonstrate that the vegetation activities decreased significantly in summer over the years. Moreover, there were significant changes in land use/cover over the past two decades. Particularly there was a sharp increase of urban and built-up area and a significant decrease of grassland and cropland. All these indicate that human activities are intensive in the East River Basin and provide valuable information for constructing scenarios for studying hydrologic impacts of LUCC. The physically-remote-sensing-based Surface Energy Balance System (SEBS) was employed to estimate areal actual ET for a large area rather than traditional point measurements . The SEBS was enhanced for application in complex vegetated area. Then the inter-comparison with complimentary ET model and distributed monthly water balance model was made to validate the enhanced SEBS (ESEBS). The application and test of ESEBS show that it has a good accuracy both monthly and annually and can be effectively applied in the East River Basin. The results of ET mapping based on ESEBS demonstrate that actual ET in the East River Basin decreases significantly in the last two decades, which is probably caused by decrease of sunshine duration. In order to effectively simulate hydrologic impact of LUCC, an integrated model of ESEBS and distributed monthly water balance model has been developed in this study. The model is capable of considering basin terrain and the spatial distribution of precipitation and soil moisture. Particularly, the model is unique in accounting for spatial and temporal variations of vegetation cover and ET, which provides a powerful tool for studying the hydrologic impacts of LUCC. The model was applied to simulate the monthly runoff for the period of 1980-1994 for model calibration and for the period of 1995-2000 for validation. The calibration and validation results show that the newly integrated model is suitable for simulating monthly runoff and studying hydrologic impacts ofLUCC in the East River Basin. Finally, the newly integrated model was firstly applied to analyze the relationship of land use and hydrologic regimes based on the land use maps in 1980 and 2000. Then the newly integrated model was applied to simulate the potential impacts of land use change on hydrologic regimes in the East River Basin under a series of hypothetical scenarios. The results show that ET has a positive relationship with Leaf Area Index (LAI) while runoff has a negative relationship with LAI in the same climatic zone, which can be elaborated by surface energy balance and water balance equation. Specifically, on an annual basis, ET of forest scenarios is larger than that of grassland or cropland scenarios. On the contrary, runoff of forest scenarios is less than that of grassland or cropland scenarios. On a monthly basis, for most of the scenarios, particularly the grassland and cropland scenarios, the most significant changes occurred in the rainy season. The results indicate that deforestation would cause increase of runoff and decrease of ET on an annual basis in the East River Basin. On a monthly basis, de

  16. Brief summary of LADHS: Los Alamos distributed hydrologic modeling system.

    SciTech Connect

    Murray, R. E. (Regan E.); Winter, C. L. (C. Larrabee); Springer, E. P.; Costigan, K. R. (Keeley R.); Tseng, P. H. (Peng-Hsiang)

    2001-01-01

    This report describes the current state of the fourth Thrust Area of the NSF Science and Technology Center for the Sustainability of Semi-Arid Hydrology and Riparian Areas (SAHRA). Sustainability of semi-arid regions has become a serious political and scientific concern. Increasing population has added stress to the water supply and other natural resources, notably, underground aquifers. Recent controversies in the Rio Grande Basin involving the competing interests of endangered species and humans for water have highlighted the delicate balance of biologically diverse southwestern riparian areas. Potentially, the warming climate may intensify summer storms and affect the amount and timing of snow melt, the largest renewable source of water in the southwest. It is, therefore, of great political, social and scientific interest to determine ways in which human activities can coexist with healthy riparian areas and a plentiful, clean water supply over the long run. An understanding of how all of these processes interrelate would allow regional decision-makers to consider a wide range of options and thereby develop useful plans for meeting societal needs. To make the best use of limited fresh water resources, decision makers must be able to make predictions about the entire hydrologic cycle, which is a complex combination of physical, chemical, and biological processes. Only then could they explore the potential effects of increased water use and of changes in the regional climate. The important processes in the hydrologic cycle include rainfall, snowmelt, storms, runoff, and flow in ephemeral streams, rivers, and underground aquifers. Riparian communities and evaporation play key roles in reducing the available water.

  17. A simplified approach to quantifying predictive and parametric uncertainty in artificial neural network hydrologic models

    E-print Network

    Chaubey, Indrajeet

    considerable interest in developing methods for uncertainty analysis of artificial neural network (ANN) models and parametric uncertainty in artificial neural network hydrologic models, Water Resour. Res., 43, W10407, doi:10A simplified approach to quantifying predictive and parametric uncertainty in artificial neural

  18. Hydrologic Modeling of a Canal-Irrigated Agricultural Watershed with Irrigation Best Management

    E-print Network

    Case Study Hydrologic Modeling of a Canal-Irrigated Agricultural Watershed with Irrigation Best Management Practices: Case Study N. Kannan1 ; J. Jeong2 ; and R. Srinivasan3 Abstract: Simulating irrigation canal-irrigated watersheds. The existing approaches to modeling canal irrigation use situation

  19. Land surface modelling in hydrology and meteorology - lessons learned from the Baltic Basin

    Microsoft Academic Search

    L. P. Graham; S. Bergström

    2000-01-01

    By both tradition and purpose, the land parameterization schemes of hydrological and meteorological models differ greatly. Meteorologists are concerned primarily with solving the energy balance, whereas hydrologists are most interested in the water balance. Meteorological climate models typically have multi-layered soil parameterisation that solves temperature fluxes numerically with diffusive equations. The same approach is carried over to a similar treatment

  20. Hydrologic nonstationarity and extrapolating models to predict the future: overview of session and proceeding

    NASA Astrophysics Data System (ADS)

    Chiew, F. H. S.; Vaze, J.

    2015-06-01

    This paper provides an overview of this IAHS symposium and PIAHS proceeding on "hydrologic nonstationarity and extrapolating models to predict the future". The paper provides a brief review of research on this topic, presents approaches used to account for nonstationarity when extrapolating models to predict the future, and summarises the papers in this session and proceeding.

  1. Hydrological modeling of the Martian crust with application to the pressurization of aquifers

    Microsoft Academic Search

    Jeffrey C. Hanna; Roger J. Phillips

    2005-01-01

    We develop a hydrological model of the Martian crust, including both ancient heavily cratered terrains and younger basaltic and sedimentary terrains. The porosity, permeability, and compressibility are represented as interdependent functions of the effective stress state of the aquifer, as determined by the combination of the lithostatic pressure and the fluid pore pressure. In the megaregolith aquifer model, the crust

  2. Rangeland Hydrology and Erosion Model (RHEM) enhancements for applications on disturbed rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rangeland Hydrology and Erosion Model (RHEM) is a new process-based model developed by the USDA-ARS. Disturbance such as fire or woody plant encroachment can amplify overland flow erosion by increasing the likelihood of concentrated flow formation. In this study, we enhanced RHEM applications on...

  3. Developing a TeraGrid Based Land Surface Hydrology and Weather Modeling Interface

    E-print Network

    Jiang, Wen

    of Cyberinfrastructure for End-to-End Environmental Explorations (C4E4), this multi-disciplinary team utilizes current, fusion of data and models has been undertaken by the C4E4 team over the St. Joseph watershed in Northern/hydrological modeling interface using a Surface Water Analysis Tool (SWAT). The focus of the current paper is to discuss

  4. Performance of a distributed semi-conceptual hydrological model under tropical watershed conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many hydrologic models have been developed to help manage natural resources all over the world. Nevertheless, most models have presented a high complexity in terms of data base requirements, as well as, many calibration parameters. This has resulted in serious difficulties to application in catchmen...

  5. The Hydrology of Malaria: Model Development and Application to a Sahelian Village

    NASA Astrophysics Data System (ADS)

    Bomblies, A.; Duchemin, J.; Eltahir, E. A.

    2008-12-01

    We present a coupled hydrology and entomology model for the mechanistic simulation of local-scale response of malaria transmission to hydrological and climatological determinants in semi-arid, desert fringe environments. The model is applied to the Sahel village of Banizoumbou, Niger, to predict interannual variability in malaria vector mosquito populations which lead to variations in malaria transmission. Using a high-resolution, small-scale distributed hydrology model that incorporates remotely-sensed data for land cover and topography, we simulate the formation and persistence of the pools constituting the primary breeding habitat of Anopheles gambiae s.l. mosquitoes, the principal regional malaria vector mosquitoes. An agent-based mosquito population model is coupled to the distributed hydrology model, with aquatic stage and adult stage components. For each individual adult mosquito, the model tracks attributes relevant to population dynamics and malaria transmission, which are updated as mosquitoes interact with their environment, humans, and animals. Weekly field observations were made in 2005 and 2006. The model reproduces mosquito population variability at seasonal and interannual time scales, and highlights individual pool persistence as a dominant control. Future developments to the presented model can be used in the evaluation of impacts of climate change on malaria, as well as the a priori evaluation of environmental management-based interventions.

  6. HYDROLOGIC MODELING OF AN EASTERN PENNSYLVANIA WATERSHED WITH NEXRAD AND RAIN GAUGE DATA

    EPA Science Inventory

    This paper applies the Soil Water Assessment Tool (SWAT) to model the hydrology in the Pocono Creek watershed located in Monroe County, Pa. The calibrated model will be used in a subsequent study to examine the impact of population growth and rapid urbanization in the watershed o...

  7. Investigation of Hydrological Variability in West Africa Using Land Surface Models.

    NASA Astrophysics Data System (ADS)

    Li, K. Y.; Coe, M. T.; Ramankutty, N.

    2005-08-01

    The availability of freshwater is a particularly important issue in Africa where large portions of the continent are arid or semiarid and climate is highly variable. Sustainable water resource management requires the assessment of hydrological variability in response to nature climate fluctuation. In this study, a land surface model, the Integrated Biosphere Simulator (IBIS), and a hydrological routing model, the Hydrological Routing Algorithm (HYDRA), are used to investigate the hydrological variability in two large basins, the Lake Chad basin (LCB) and the Niger River basin (NRB), located in West Africa, over the period from 1950 to 1995. The IBIS land surface hydrological module was calibrated and validated for arid and semiarid Africa, and major enhancements were made to the module, including the development of a dynamic root water-extraction formulation, the incorporation of a Green-Ampt infiltration parameterization, and modification to the prescribed root distribution, the runoff module, and weather generator. The results show that the hydrology in this area is highly variable over time and space. The coefficient of variance (CV) of annual rainfall ranges from 10%-15% in the southern portions of the basins to 30%-40% in the northern portions. The annual evapotranspiration (ET) varies with a slightly lower CV compared to the rainfall, but the runoff is extremely sensitive to the rainfall fluctuation, particularly in the central portions of the basins (8°-13°N in LCB and 12°-16°N in NRB) where the CVs in runoff are as high as 100%-200%. The annual river discharge varies largely in concert with the rainfall fluctuation, with the CV being 37% in LCB and 23%-63% in NRB. In terms of the whole basin, the relative hydrologic variability (rainfall, evapotranspiration, runoff, and river discharge) is significantly higher in the dry period than in the wet period, and the interannual variability in runoff is more than twice as high as compared to rainfall or ET.

  8. Coupling urban expansion models and hydrological models: how important are spatial patterns?

    NASA Astrophysics Data System (ADS)

    Poelmans, Lien; van Rompaey, Anton; Batelaan, Okke

    2010-05-01

    It is well known that urban expansion has a significant impact on the surface water balance by transforming vegetated covers into sealed surfaces, such as buildings, roads and parking spaces. These changes alter several hydrological processes at various spatial and temporal scales and thus cause changing fluxes of evapotranspiration, surface runoff and groundwater recharge. In order to estimate the impact of urban expansion on the surface hydrology, hydrological models are often ‘loosely' coupled with different types of urban expansion models. It is, however, not clear to what extent spatially-explicit urban expansion scenarios provide an added value in comparison with non-spatial urban expansion models at different scale levels. The objective of this study is to acquire a better insight in the importance of scale effects involved in the loose coupling of urban expansion scenarios and hydrological models. The relative importance of using different projections of both (i) quantity and (ii) spatial patterns of urban expansion was analysed at four different scale levels. The highly urbanised Flanders-Brussels region was taken as an example application. A number of urban expansion scenarios for 2025 and 2050, that varied in terms of quantity and spatial pattern of urban expansion, was developed and subsequently used as an input in the hydrological model WetSpass. WetSpass is a physically based spatially-distributed water balance model for simulating seasonal and yearly groundwater recharge, actual evapotranspiration and surface runoff. The results obtained suggest that at the level of the Flanders-Brussels region, an accurate estimation of the quantity of urban expansion should get priority over an accurate projection of the spatial patterns. The quantity uncertainty related to the use of different urban expansion scenarios resulted in a 17% uncertainty on the assessed runoff values, 1.5% on the evapotranspiration values and 4.5% on the estimated groundwater recharge. Comparable uncertainty values could be observed on all four analysed scale levels. On the other hand, the importance of using accurate projections of the spatial pattern of urban expansion increased systematically with an increasing spatial resolution. At the level of individual subcatchments the uncertainty related to the spatial patterns of urban expansion equalled the uncertainty related to the quantity assessment. At the level of individual pixels, an accurate projection of the spatial patterns was even found to be more important than an accurate assessment of the quantities of urban growth. Based on the results from this study it can be concluded that a uniform strategy for coupling urban expansion models and hydrological models seems inappropriate. The smaller the area under investigation, the more effort should be put in an accurate simulation of the spatial patterns of land cover change. These findings are highly relevant for water management and spatial planning policymakers that typically operate at different administrative levels.

  9. Improving un-gauged hydrological modeling by assimilating GRACE Terrestrial Water Storage data

    NASA Astrophysics Data System (ADS)

    Huang, K.; Li, X.; Liang, J.; Liu, X.

    2013-12-01

    Hydrological modeling usually requires accurate meteorological gauge data, which might pose challenges for those sparsely gauged or un-gauged regions. One alternative approach is to use reanalysis datasets from meteorological modeling. However, models driven by reanalysis data are less reliable than those driven by well-gauged ones, due to the relatively inaccurate meteorological forces. In this paper, we propose a new approach to improve the reliability of the hydrological modeling driven by reanalysis data, via assimilating the terrestrial water storage (TWS) data measured by the Gravity Recovery and Climate Experiment (GRACE) satellite system. Launched at 2002, the GRACE system enables the unprecedented measurements of global TWS anomalies, which are potentially useful in the poorly gauged regions. In order to justify this approach, we assimilated the GRACE TWS data into a reanalysis data driven SWAT model. This catchment model was driven by Climate Forecast System Reanalysis (CFSR) data, and was set up to simulate the hydrological process in the Pearl River Basin (PRB), South China, from 2003 to 2005. The simulated stream flows were then evaluated against the monthly observations obtained from 9 hydrological stations in the PRB. Overall, the RMSE of the assimilation results (10080 cms) is about 30% smaller than that of the open-loop simulation (15452 cms). The experimental results suggest that the assimilation of GRACE TWS data is capable of improving the reliability of reanalysis data-driven modeling, and this approach is potentially useful in those sparsely gauged or un-gauged regions.

  10. Implications for karst hydrology from 3D geological modeling using the aquifer base gradient approach

    NASA Astrophysics Data System (ADS)

    Butscher, Christoph; Huggenberger, Peter

    2007-08-01

    SummaryWe use the gradient of the aquifer base to investigate the hydrology of mature, shallow karst systems. We first present a 3D geological model of the Gempen plateau (NW Switzerland) that reveals the geometry of aquifers and aquitards and their displacement at faults, then transfer the 3D geological model to a hydrological model. The transformation is based on a conceptual karst model approximating subsurface flow in mature, shallow karst systems to open surface flow on the top of the uppermost aquitard or aquifer base. The gradient of this surface is expected to mainly influence regional groundwater flow patterns. We use the hydrological model to delineate spring catchment areas. The discharge areas and corresponding catchment areas of the model are compared with the occurrence of springs in the study area and with hydraulic links confirmed by tracer tests. We also describe the way in which the hydrological model contributes to identifying flow processes. The proposed aquifer base gradient approach enhances vulnerability assessment in mature, shallow karst regions by (1) localizing catchment areas as a precondition of source protection strategies and (2) indicating dominant flow processes associated with individual springs.

  11. Collaborative experiment on intercomparison of regional-scale hydrological models for climate impact assessment

    NASA Astrophysics Data System (ADS)

    Krysanova, Valentina; Hattermann, Fred

    2015-04-01

    The Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) is a community-driven modelling effort bringing together impact modellers across sectors and scales to create more consistent and comprehensive projections of the impacts of climate change. This project is aimed in establishing a long-term, systematic, cross-sectoral impact model intercomparison process, including comparison of climate change impacts for multiple sectors using ensemble of climate scenarios and applying global and regional impact models. The project is coordinated by the Potsdam Institute for Climate Impact Research. An overview of this project and collaborative experiment related to the regional-scale water sector model intercomparison in ISI-MIP will be presented. The regional-scale water sector modelling includes eleven models applied to eleven large-scale river basins worldwide (not every model is applied to every of eleven basins). In total, 60-65 model applications will be done by several collaborating groups from different Institutions. The modelling tools include: ECOMAG, HBV, HBV-light, HYPE, LASCAM, LISFLOOD, mHM, SWAT, SWIM, VIC and WaterGAP. Eleven river basins chosen for the model application and intercomparison are: the Rhine and Tagus in Europe, the Niger and Blue Nile in Africa, the Ganges, Lena, Upper Yellow and Upper Yangtze in Asia, the Upper Mississippi and Upper Amazon in America, and the Murray-Darling in Australia. Their drainage areas range between 67,490 km2 (Tagus) to 2,460,000 km2 (Lena). Data from global and regional datasets are used for the model setup and calibration. The model calibration and validation was done using the WATCH climate data for all cases, also checking the representation of high and low percentiles of river discharge. For most of the basins, also intermediate gauge stations were included in the calibration. The calibration and validation results, evaluated with the Nash and Sutcliffe efficiency (NSE) and percent bias (PBIAS), are mostly satisfactory. As the next task, climate scenarios from five GCMs driven by four RCPs will be applied, and model outputs intercompared. The presentation will focus on coordination and communication problems, designing the modelling procedure, creating a modelling protocol, and data supply.

  12. Hydrologic modeling to predict performance of shallow land burial cover designs at the Los Alamos National Laboratory

    SciTech Connect

    Nyhan, J.W.

    1989-03-01

    The water balance relationships of two shallow land burial (SLB) cover configurations were studied using a hydrologic model in a preliminary attempt to design waste disposal site covers for successful long-term closure at Los Alamos. Burial site performance requirements for site closure are first discussed, along with the role of hydrologic models in assessing the dynamics of the hydrology of the SLB cover. The calibration of a hydrologic model using field data from two SLB cover designs is then described, followed by an analysis of long-term climatic model input parameters across Los Alamos National Laboratory. These two calibrated models are then used to evaluate the influence of vegetation, precipitation, and runoff curve number on the design of SLB covers within Los Alamos county. Future directions of field research efforts and subsequent hydrologic modeling activities were recommended in terms of their usefulness for waste management decisions to be made at Los Alamos. 24 refs., 17 figs., 9 tabs.

  13. Evaluating temporal and spatial variations in recharge and streamflow using the Integrated Landscape Hydrology Model (ILHM)

    NASA Astrophysics Data System (ADS)

    Hyndman, David W.; Kendall, Anthony D.; Welty, Nicklaus R. H.

    Projections of climate and land use changes suggest that there will be significant alterations to the hydrology of the Upper Midwest. Forecasting those changes at regional scales requires new modeling tools that take advantage of increases in computational power and the latest GIS and remote-sensing datasets. Because of the need to resolve fine-scale processes, fully coupled numerical simulations of regional watersheds are still prohibitive. Although semi-distributed lumped-parameter models are an alternative, they are often not able to accurately forecast across a broad range of hydrologic conditions such as those associated with climate and land use changes. We have developed a loosely coupled suite of hydrologic codes called the Integrated Landscape Hydrology Model (ILHM), which combines readily available numerical and energy- and mass-balance modeling codes with novel routines. In this paper, the ILHM is used to predict hydrologic fluxes through a 130 km2 portion of the Muskegon River Watershed in northern-lower Michigan. We combine GIS maps of the land cover, soils, and sediments with a variety of gaged and remotely sensed data for this watershed to simulate evapotranspiration, groundwater recharge, and stream discharge from 1990-2004. These estimates are compared to measured stream discharge data to demonstrate the capability of the ILHM to provide reasonable predictions of groundwater recharge with minimal calibration. The results begin to illustrate critical differences in hydrologic processes due to land cover and climate variability, including a demonstration that approximately 75% of precipitation becomes recharge during leaf-off periods while almost no recharge occurs during the growing season.

  14. Multi-Model Combination techniques for Hydrological Forecasting: Application to Distributed Model Intercomparison Project Results

    SciTech Connect

    Ajami, N K; Duan, Q; Gao, X; Sorooshian, S

    2005-04-11

    This paper examines several multi-model combination techniques: the Simple Multi-model Average (SMA), the Multi-Model Super Ensemble (MMSE), Modified Multi-Model Super Ensemble (M3SE) and the Weighted Average Method (WAM). These model combination techniques were evaluated using the results from the Distributed Model Intercomparison Project (DMIP), an international project sponsored by the National Weather Service (NWS) Office of Hydrologic Development (OHD). All of the multi-model combination results were obtained using uncalibrated DMIP model outputs and were compared against the best uncalibrated as well as the best calibrated individual model results. The purpose of this study is to understand how different combination techniques affect the skill levels of the multi-model predictions. This study revealed that the multi-model predictions obtained from uncalibrated single model predictions are generally better than any single member model predictions, even the best calibrated single model predictions. Furthermore, more sophisticated multi-model combination techniques that incorporated bias correction steps work better than simple multi-model average predictions or multi-model predictions without bias correction.

  15. Assessing agriculture–water links at the basin scale: hydrologic and economic models of the São Francisco River Basin, Brazil

    Microsoft Academic Search

    Marco Maneta; Marcelo Torres; Stephen A. Vosti; Wesley W. Wallender; Summer Allen; Luís H. Bassoi; Lisa Bennett; Richard Howitt; Lineu Rodrigues; Julie Young

    2009-01-01

    This article uses a basin-wide hydrologic model to assess the hydrologic and economic effects of expanding agriculture in the São Francisco River Basin, Brazil. It then uses a basin-wide economic model of agriculture to examine the effects of implementing water use regulations. Preliminary results suggest that substantially expanding agriculture would put pressure on some of the river's environmental flows. Agricultural

  16. High-dimensional posterior exploration of hydrologic models using multiple-try DREAM(ZS) and high-performance computing

    E-print Network

    Vrugt, Jasper A.

    of hydrologic models using multiple-try DREAM(ZS) and high-performance computing, Water Resour. Res., 48, W01526High-dimensional posterior exploration of hydrologic models using multiple-try DREAM(ZS) and high-performance performance improvement over other adaptive MCMC approaches when using distributed computing. Four different

  17. Simulation of the Global Hydrological Cycle in the CCSM Community Atmosphere Model Version 3 (CAM3): Mean Features

    Microsoft Academic Search

    James J. Hack; Julie M. Caron; Stephen G. Yeager; Keith W. Oleson; Marika M. Holland; John E. Truesdale; Philip J. Rasch

    2006-01-01

    The seasonal and annual climatological behavior of selected components of the hydrological cycle are presented from coupled and uncoupled configurations of the atmospheric component of the Community Climate System Model (CCSM) Community Atmosphere Model version 3 (CAM3). The formulations of processes that play a role in the hydrological cycle are significantly more complex when compared with earlier versions of the

  18. Distributed Hydrological Model with New Soil Water Parameterization for Integrating Remotely Sensed Soil Moisture at Watershed Scale

    Microsoft Academic Search

    Zhang Wanchang; Chen Jiongfeng

    2008-01-01

    Detailed vertical soil moisture profile is essential for hydrological modeling and is also often used as important diagnostic information for better understanding the surface-atmospheric interactions. This paper presents a modified ESSI distributed hydrological model that is suitable for comparing and assimilating the remotely sensed soil moisture by integrating a soil water parameterization scheme which is able to numerically calculates soil

  19. Development of a Coupled Hydrological/Sediment Yield Model for a Watershed at Regional Level

    NASA Technical Reports Server (NTRS)

    Rajbhandaril, Narayan; Crosson, William; Tsegaye, Teferi; Coleman, Tommy; Liu, Yaping; Soman, Vishwas

    1998-01-01

    Development of a hydrologic model for the study of environmental conservation requires a comprehensive understanding of individual-storm affecting hydrologic and sedimentologic processes. The hydrologic models that we are currently coupling are the Simulator for Hydrology and Energy Exchange at the Land Surface (SHEELS) and the Distributed Runoff Model (DRUM). SHEELS runs continuously to estimate surface energy fluxes and sub-surface soil water fluxes, while DRUM operates during and following precipitation events to predict surface runoff and peak flow through channel routing. The lateral re-distribution of surface water determined by DRUM is passed to SHEELS, which then adjusts soil water contents throughout the profile. The model SHEELS is well documented in Smith et al. (1993) and Laymen and Crosson (1995). The model DRUM is well documented in Vieux et al. (1990) and Vieux and Gauer (1994). The coupled hydrologic model, SHEELS/DRUM, does not simulate sedimentologic processes. The simulation of the sedimentologic process is important for environmental conservation planning and management. Therefore, we attempted to develop a conceptual frame work for coupling a sediment yield model with SHEELS/DRUM to estimate individual-storm sediment yield from a watershed at a regional level. The sediment yield model that will be used for this study is the Universal Soil Loss Equation (USLE) with some modifications to enable the model to predict individual-storm sediment yield. The predicted sediment yield does not include wind erosion and erosion caused by irrigation and snow melt. Units used for this study are those given by Foster et al. (1981) for SI units.

  20. Evaluation of the value of radar QPE data and rain gauge data for hydrological modeling

    NASA Astrophysics Data System (ADS)

    He, Xin; Sonnenborg, Torben O.; Refsgaard, Jens Christian; Vejen, Flemming; Jensen, Karsten H.

    2013-09-01

    Weather radar-based quantitative precipitation estimation (QPE) is in principle superior to the areal precipitation estimated by using rain gauge data only, and therefore has become increasingly popular in applications such as hydrological modeling. The present study investigates the potential of using multiannual radar QPE data in coupled surface water—groundwater modeling with emphasis given to the groundwater component. Since the radar QPE is partly dependent on the rain gauge observations, it is necessary to evaluate the impact of rain gauge network density on the quality of the estimated rainfall and subsequently the simulated hydrological responses. A headwater catchment located in western Denmark is chosen as the study site. Two hydrological models are built using the MIKE SHE code, where they have identical model structures expect for the rainfall forcing: one model is based on rain gauge interpolated rainfall, while the other is based on radar QPE which is a combination of both radar and rain gauge information. The two hydrological models are inversely calibrated and then validated against field observations. The model results show that the improvement introduced by using radar QPE data is in fact more obvious to groundwater than to surface water at daily scale. Moreover, substantial negative impact on the simulated hydrological responses is observed due to the cut down in operational rain gauge network between 2006 and 2010. The radar QPE based model demonstrates the added value of the extra information from radar when rain gauge density decreases; however it is not able to sustain the level of model performance preceding the reduction in number of rain gauges.

  1. Hydrology of malaria: Model development and application to a Sahelian village

    NASA Astrophysics Data System (ADS)

    Bomblies, Arne; Duchemin, Jean-Bernard; Eltahir, Elfatih A. B.

    2008-12-01

    We present a coupled hydrology and entomology model for the mechanistic simulation of local-scale response of malaria transmission to hydrological and climatological determinants in semiarid, desert fringe environments. The model is applied to the Sahel village of Banizoumbou, Niger, to predict interannual variability in malaria vector mosquito populations that lead to variations in malaria transmission. Using a high-resolution, small-scale distributed hydrology model that incorporates remotely sensed data for land cover and topography, we simulate the formation and persistence of the pools constituting the primary breeding habitat of Anopheles gambiae s.l. mosquitoes, the principal regional malaria vector mosquitoes. An agent-based mosquito population model is coupled to the distributed hydrology model, with aquatic-stage and adult-stage components. Through a dependence of aquatic-stage mosquito development and adult emergence on pool persistence, we model small-scale hydrology as a dominant control of mosquito abundance. For each individual adult mosquito, the model tracks attributes relevant to population dynamics and malaria transmission, which are updated as mosquitoes interact with their environment, humans, and animals. Weekly field observations were made in 2005 and 2006. A 16% increase in rainfall between the two years was accompanied by a 132% increase in mosquito abundance between 2005 and 2006. The model reproduces mosquito population variability at seasonal and interannual timescales and highlights individual pool persistence as a dominant control. Future developments of the presented model can be used in the evaluation of impacts of climate change on malaria, as well as the a priori evaluation of environmental management-based interventions.

  2. Flash flood prediction using an uncalibrated hydrological model and radar rainfall data in a Mediterranean watershed under changing hydrological conditions

    NASA Astrophysics Data System (ADS)

    Rozalis, Shahar; Morin, Efrat; Yair, Yoav; Price, Colin

    2010-11-01

    SummaryFlash floods cause some of the most severe natural disasters in Europe but Mediterranean areas are especially vulnerable. They can cause devastating damage to property, infrastructures and loss of human life. The complexity of flash flood generation processes and their dependency on different factors related to watershed properties and rainfall characteristics make flash flood prediction a difficult task. In this study, as part of the EU-FLASH project, we used an uncalibrated hydrological model to simulate flow events in a 27 km2 Mediterranean watershed in Israel to analyze and better understand the various factors influencing flows. The model is based on the well-known SCS curve number method for rainfall-runoff calculations and on the kinematic wave method for flow routing. Existing data available from maps, GIS and field studies were used to define model parameters, and no further calibration was conducted to obtain a better fit between computed and observed flow data. The model rainfall input was obtained from the high temporal and spatial resolution radar data adjusted to rain gauges. Twenty flow events that occurred within the study area over a 15 year period were analyzed. The model shows a generally good capability in predicting flash flood peak discharge in terms of their general level, classified as low, medium or high (all high level events were correctly predicted). It was found that the model mainly well predicts flash floods generated by intense, short-lived convective storm events while model performances for low and moderate flows generated by more widespread winter storms were quite poor. The degree of urban development was found to have a large impact on runoff amount and peak discharge, with higher sensitivity of moderate and low flow events relative to high flows. Flash flood generation was also found to be very sensitive to the temporal distribution of rain intensity within a specific storm event.

  3. Assessment of hydrological model predictive ability given multiple conceptual geological models

    NASA Astrophysics Data System (ADS)

    Seifert, Dorte; Sonnenborg, Torben O.; Refsgaard, Jens Christian; HøJberg, Anker L.; Troldborg, Lars

    2012-06-01

    In this study six hydrological models that only differ with respect to their conceptual geological models are established for a 465 km2 area. The performances of the six models are evaluated in differential split-sample tests against a unique data set with well documented groundwater head and discharge data for different periods with different groundwater abstractions. The calibration results of the six models are comparable, with no model being superior to the others. Though, the six models make very different predictions of changes in groundwater head and discharges as a response to changes in groundwater abstraction. This confirms the utmost importance of the conceptual geological model for making predictions of variables and conditions beyond the calibration situation. In most cases the observed changes in hydraulic head and discharge are within the range of the changes predicted by the six models implying that a multiple modeling approach can be useful in obtaining more robust assessments of likely prediction errors. We conclude that the use of multiple models appear to be a good alternative to traditional differential split-sample schemes. A model averaging analysis shows that model weights estimated from model performance in the calibration or validation situation in many cases are not optimal for making other predictions. Hence, the critical assumption that is always made in model averaging, namely that the model weights derived from the calibration situation are also optimal for model predictions, cannot be assumed to be generally valid.

  4. Quantifying conceptual hydrological flow paths across heterogeneous conditions using a tailored catchment model

    NASA Astrophysics Data System (ADS)

    Mockler, Eva M.; Bruen, Michael

    2015-04-01

    As hydrology drives the nutrient and sediment processes at catchment scale, the hydrological processes in a model must be adequately represented in order for water quality simulations to be meaningful. Focus is increasingly turning to the internal movement of water within conceptual rainfall runoff models to investigate if the simulated processes contributing to the total flows are realistic. Difficulty arises when defining two or more flow paths that are conceptually distinct in relation to nutrient and sediment signatures, but have similar or overlapping discharge hydrograph responses. When this occurs, methods relating to physical hydrograph separation cannot be expected to distinguish between the different responses. There is a wealth of knowledge and conceptual understanding of hydrological and hydrogeological processes across Ireland. This knowledge has been incorporated into several spatial datasets of catchment characteristics including the Geological Survey of Ireland Groundwater Vulnerability Map and National Recharge Map. A tailored conceptual model for simulating flows in Irish catchments was developed that is linked with catchment characteristics to constrain internal flow paths and guide parameterisation. Simulations for 31 catchments were compared with output from two established models. The additional process information in the new model structure resulted in an improved or equalled performance in most catchment, with an increase in overall average performance criteria. This was attributed to the tailored model structure that more closely reflects the dominant hydrological processes in Irish catchments. The proportion of flow through groundwater or 'quick' flow paths varies considerably depending on catchment settings, with examples of groundwater dominated and 'flashy' catchments included in the study. In contrast to earlier studies, results showed interflow, as opposed to overland flow, as the dominant flow path in Irish catchments. This new finding was influenced by the inclusion of artificial land drains in the conceptual model, which is an important flow path in low permeability agricultural areas. Work is on-going to couple the hydrological model with water quality components so these results can inform the simulation of nutrients and sediments.

  5. The use of coupled atmospheric and hydrological models for water-resources management in headwater basins

    USGS Publications Warehouse

    Leavesley, G.; Hay, L.

    1998-01-01

    Coupled atmospheric and hydrological models provide an opportunity for the improved management of water resources in headwater basins. Issues currently limiting full implementation of coupled-model methodologies include (a) the degree of uncertainty in the accuracy of precipitation and other meteorological variables simulated by atmospheric models, and (b) the problem of discordant scales between atmospheric and bydrological models. Alternative methodologies being developed to address these issues are reviewed.

  6. Analysis of Sub-Antarctic Lakes Using a Coupled Hydrology and Ice Flexure Modeling Approach

    NASA Astrophysics Data System (ADS)

    Dow, C. F.; Nowicki, S.; Walker, R. T.; Werder, M. A.; Babonis, G. S.; Csatho, B. M.

    2014-12-01

    The role of sub-Antarctic lakes in subglacial hydrological development and ice dynamics is not well constrained. We present a novel coupled modeling approach for assessing the stability of subglacial lakes in the Antarctic, the controls on their growth and demise, and the downstream impact of leakage of water from these substantial water reservoirs. Our method utilizes GlaDS, a 2-D finite element hydrology model, with the capability for development of a coexisting distributed and efficient drainage system. To better constrain lake growth and drainage, along with the dynamic impact of the water reservoir, we locally couple the hydrology model to an ice flexure model. We are interested in constraining the change in local ice stresses due to the growth of lakes and assessing the triggers of rapid or slow lake drainage. These lake dynamic analyses contribute to our assessment of the role of lakes in basal hydrology, with a focus on ice streams, where we examine whether the drainage mechanisms have an impact on regional ice dynamics. Here we present our method and initial results from the coupled model.

  7. Development of Dam Operation Scheme in a Hydrology Model

    NASA Astrophysics Data System (ADS)

    He, Y.; Liang, X.

    2013-12-01

    A novel scheme for dam operation has been developed based on the artificial neural network approach to predict the reservoir management and hydrologic effects in response to climate variation and change. The scheme is built upon the historic management information of operating each dam, including climate, ecology properties and attributes (e.g., storage, surface area) for all relevant reservoirs. The scheme implicitly introduces the relationship between water demand and supply for downstream fluvial ecosystem, agriculture irrigation, and hydropower. This study will first present the fundamental formulation of the predictive scheme along with detailed analysis of the historical management data, and then evaluate the performance for its application in the Colorado River basin. Caveats and merits will also be discussed.

  8. Field experiment and Modeling full coupling hydrologic model with mircotopography in typical watershed

    NASA Astrophysics Data System (ADS)

    Xiang, Long; Zhu, Yongshu; Xu, Ruchao; Yu, Zhongbo; Chen, Li

    2015-04-01

    With high human activties and landscape remodeling, the various landuse and micropography are newly added in scienctific sight. In order to quanify the solpo effect in high resolution sub-grid system, three-dimensional Richards' equations and the two-dimensional diffusion wave equations are chosen to solve the output difference between hydro-flows, The difficulty of quantitating surface water and groundwater interaction and parameterizing the microtopography with the help of multi-scale observation experiments. For three-dimensional coupling mechanism in surface-subsurface system, we design real-time observations on water flow at Hydrologic Response Units (HRU) located on various landuse and outlet in Meilin experimental watershed. The continuously observed data disclose the principle of runoff yield spatially and temporally, and show the surface runoff redistribution, unsaturated soil water dynamics, shallow groundwater response to typical rainfall-runoff events on complex microtopographic slope. A surface storage function with elevation various is embeded into diffuse wave equations to describe microtopographic effect. we improve for paramterizing microtopography in subelements and evaluate the strength of microtopography and couple length at soil-water interface impacting the hydrologic modeling. Based on observed conclusions, a full physical based distributed model system is established at Meilin watershed to quantify the hydrodynamic processes of overland flow, soil water saturation, and groundwater level and analyze dynamic exchanges among them in simulation. The relationships between the various saturation area (VSA) and runoff yield and flow confluence in each typical event are quantified statistically. With the field work and simulations, we demostrated the approach to describe complex hydrologic processes in human-interrupted watershed. Keywords: micropography, coupling mechanism, various saturation area, surface storage

  9. Hydrology of Malaria: A New Class of Models for Environmental Management and Studies of Climate Change

    NASA Astrophysics Data System (ADS)

    Eltahir, E. A.

    2011-12-01

    A mechanistic and spatially-explicit model of hydrological and entomological processes that lead to malaria transmission is developed and tested against field observations. HYDREMATS (HYDRology, Entomology, and MAlaria Transmission Simulator) is described in (Bomblies and Eltahir, WRR, 44,2008). HYDREMATS is suitable for low cost screening of environmental management interventions, and for studying the impact of climate change on malaria transmission. Examples of specific applications will be presented from Niger in Africa. The potential for using HYDREMATS to study the impact of water reservoirs on malaria transmission will be discussed.

  10. Model representation of the Sudanian hydrological processes: Application on the Donga catchment (Benin)

    NASA Astrophysics Data System (ADS)

    Le Lay, M.; Saulnier, G.-M.; Galle, S.; Seguis, L.; Métadier, M.; Peugeot, Ch.

    2008-12-01

    SummaryDuring the AMMA (African Monsoon Multidisciplinary Analysis) program, intensive field experiments were conducted on the Donga catchment (586 km 2), which is part of the Ouémé surveyed hydrological watershed (14,400 km 2). Based on these studies, a number of general hydrological assumptions were derived to explain the hydrological functioning of catchments located in the Sudanian hydrological area of West Africa. To take advantage of this field-acquired knowledge in the study of the impacts of climate and anthropogenic changes in these catchments, a model (TOPAMMA) was derived based on these hydrological assumptions. Subsurface lateral fluxes were described in the model using the TOPMODEL framework. The recharge of the deep water table was also modelled, taking into account its disconnection from the river network. Simple geomorphologic approaches were used to estimate the time-transfer of both surface and subsurface water fluxes. Finally, to be consistent with the available meteorological data, a simple parameterization of evapotranspiration was added to the model. This paper details this modelisation as well as its corroboration on the Donga catchment. The data collected over the catchment during the 2002-2004 periods was therefore used at different scales, within either a quantitative or qualitative perspective. The results show that the model representation of the water cycle is quite realistic, which allows the AMMA community to have a useful tool available for water balance studies on the Sudanian region. However, further field investigations are necessary to confirm main model assumptions. Finally, the process representation in the model is now improved, especially with regard to the description of spatial land-surface heterogeneities and surface-atmosphere interactions.

  11. Hydrologic modeling to screen potential environmental management methods for malaria vector control in Niger

    NASA Astrophysics Data System (ADS)

    Gianotti, Rebecca L.; Bomblies, Arne; Eltahir, Elfatih A. B.

    2009-08-01

    This paper describes the first use of Hydrology-Entomology and Malaria Transmission Simulator (HYDREMATS), a physically based distributed hydrology model, to investigate environmental management methods for malaria vector control in the Sahelian village of Banizoumbou, Niger. The investigation showed that leveling of topographic depressions where temporary breeding habitats form during the rainy season, by altering pool basin microtopography, could reduce the pool persistence time to less than the time needed for establishment of mosquito breeding, approximately 7 days. Undertaking soil surface plowing can also reduce pool persistence time by increasing the infiltration rate through an existing pool basin. Reduction of the pool persistence time to less than the rainfall interstorm period increases the frequency of pool drying events, removing habitat for subadult mosquitoes. Both management approaches could potentially be considered within a given context. This investigation demonstrates that management methods that modify the hydrologic environment have significant potential to contribute to malaria vector control in water-limited, Sahelian Africa.

  12. Evaluation of CMIP climate model hydrological output for the Mississippi River Basin using GRACE satellite observations

    NASA Astrophysics Data System (ADS)

    Freedman, Frank R.; Pitts, Katherine L.; Bridger, Alison F. C.

    2014-11-01

    We use measurements of terrestrial water storage (TWS) inferred from Gravity Recovery and Climate Experiment (GRACE) satellite observations to evaluate the hydrological output composite-averaged over the Mississippi River Basin (MSRB) and over the ten-year period 2003-2012 from a subset of GCMs from the World Climate Research Programme's Coupled Model Intercomparison Project Phase 5 (CMIP5) and Phase 3 (CMIP3). We then investigate mid-20th to 21st century hydrological trends over the MSRB projected by the CMIP5 models. Improvements were found in CMIP5 simulations of the annual cycle of composite TWS, estimated as the sum of modeled depth-integrated soil moisture and snow water, over those of CMIP3 when compared with the GRACE composite TWS cycle. These improvements coincide with higher horizontal resolution and changes in hydrological parameterizations applied in most of the CMIP5 GCMs compared to earlier CMIP3 versions. Simulated values of composite hydrological budget terms among CMIP5 models, however, are not improved overall, with some models exhibiting increased precipitation and others decreased runoff from CMIP3 to CMIP5 to values outside long-term observed ranges. Since the effect of both increased precipitation and decreased runoff is to increase infiltration and soil water retention, the composite TWS annual cycles from these CMIP5 models, whose earlier CMIP3 simulations in some cases highly underestimated TWS annual cycle amplitudes compared to GRACE, now better agree with GRACE. In spite of the improved prediction of the composite TWS annual cycle, multi-decadal hydrological trends for the MSRB produced by the CMIP5 models vary. A consensus for future decreasing soil moisture is found among models, but with varied responses in magnitude as well as in direction of annual precipitation, evapotranspiration and runoff trends. Overall, GRACE data appear highly useful for evaluating GCM hydrological predictions over large river basins, and a longer time period of these data as more retrievals become available should help to evaluate GCM hydrological output on a multi-decadal time scale.

  13. Development of a coupled soil erosion and large-scale hydrology modeling system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion models are usually limited in their application to the field-scale; however, the management of land resources requires information at the regional scale. Large-scale physically-based land surface schemes (LSS) provide estimates of regional scale hydrologic processes that contribute to e...

  14. Hydrologic modelings\\/GIS as an aid in locating monitoring sites

    Microsoft Academic Search

    W. D. Rosenthal; D. W. Hoffman

    1999-01-01

    With the increasing importance and awareness of non-point source pollution, critical siting of water quality monitoring stations becomes important. Within large watersheds this siting becomes difficult because of the time and expense to travel the entire watershed and evaluate the area. Previous work has shown that hydrologic models can assist in evaluating water quality in large watersheds. In this study,

  15. Does hydrological connectivity improve modelling of coarse sediment delivery in upland environments?

    Microsoft Academic Search

    Simon C. Reid; David R. Montgomery; Christopher J. Brookes

    2007-01-01

    Modelling the delivery of landslide-generated sediment to channel networks is challenging due to uncertainty in the magnitude–frequency distribution of failures connected to the channel network. Here, we investigate a simplified treatment of hydrological connectivity as a means for improving identification of coarse sediment delivery to upland rivers. Sediment generation from hillslopes and channel banks and its delivery to the channel

  16. Object-Oriented Classification to Map Impervious Surfaces for Hydrologic Models 1956

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Urban growth in the southwestern U.S. influences strongly storm water runoff by creating impervious surfaces. Hydrologic models used to compute runoff from watersheds require an estimate of the area and location of pervious surfaces as input data. In semi-arid regions, this information is provided c...

  17. HYDROLOGIC AND ATRAZINE SIMULATION IN THE CEDAR CREEK WATERSHED USING THE SWAT MODEL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the major factors contributing to surface water contamination in agricultural areas is the use of pesticides. The Soil and Water Assessment Tool (SWAT) is a hydrologic model capable of simulating the fate and transport of pesticides in an agricultural watershed. SWAT was used in this study to...

  18. A real-time hydrological model for flood prediction using GIS and the WWW

    E-print Network

    Blackburn, Alan

    A real-time hydrological model for flood prediction using GIS and the WWW W. Al-Sabhan *, M, London, WC2R 2LS, UK Abstract The purpose of this paper is to examine the current status of real time are available, they are poorly suited to real time application, are often not well integrated with spatial

  19. Hydrological modeling of upper Indus Basin and assessment of deltaic ecology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Managing water resources is mostly required at watershed scale where the complex hydrology processes and interactions linking land surface, climatic factors and human activities can be studied. Geographical Information System based watershed model; Soil and Water Assessment Tool (SWAT) is applied f...

  20. Improving perceptual and conceptual hydrological models using data from small basins 2141

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper demonstrates how data from a small experimental basin can be used to evaluate possible structures for a lumped hydrological model. Data collected at the Mahurangi experimental basin in New Zealand includes rainfall, streamflow and multi-depth soil moisture time-series data. We use this da...

  1. Coupling of hydrologic and hydraulic models for the Illinois River Basin

    Microsoft Academic Search

    Yanqing Lian; I-Chi Chan; Jaswinder Singh; Misganaw Demissie; Vernon Knapp; Hua Xie

    2007-01-01

    The Hydrologic Simulation Program Fortran (HSPF) was applied to the Illinois River Basin using the U.S. Environmental Protection Agency's (USEPA) Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) system. Values of the HSPF model parameters were based on the calibrations of three representative watersheds within the basin. Over the 1985 1995 simulation period, monthly and annual mass balances correlated

  2. The Use of Binary Optimization and Hydrologic Models to Form Riparian Buffers

    Microsoft Academic Search

    Marcelo Cerucci; Jon M. Conrad

    2003-01-01

    Riparian buffers are considered important management options for protecting water quality. Land costs and buffer performance, which are functions of local environmental characteristics, are likely to be key attributes in the selection process, especially when budgets are limited. In this article we demonstrate how a framework involving hydrologic models and binary optimization can be used to find the optimal buffer

  3. A balanced water layer concept for subglacial hydrology in large scale ice sheet models

    NASA Astrophysics Data System (ADS)

    Goeller, S.; Thoma, M.; Grosfeld, K.; Miller, H.

    2012-12-01

    There is currently no doubt about the existence of a wide-spread hydrological network under the Antarctic ice sheet, which lubricates the ice base and thus leads to increased ice velocities. Consequently, ice models should incorporate basal hydrology to obtain meaningful results for future ice dynamics and their contribution to global sea level rise. Here, we introduce the balanced water layer concept, covering two prominent subglacial hydrological features for ice sheet modeling on a continental scale: the evolution of subglacial lakes and balance water fluxes. We couple it to the thermomechanical ice-flow model RIMBAY and apply it to a synthetic model domain inspired by the Gamburtsev Mountains, Antarctica. In our experiments we demonstrate the dynamic generation of subglacial lakes and their impact on the velocity field of the overlaying ice sheet, resulting in a negative ice mass balance. Furthermore, we introduce an elementary parametrization of the water flux-basal sliding coupling and reveal the predominance of the ice loss through the resulting ice streams against the stabilizing influence of less hydrologically active areas. We point out, that established balance flux schemes quantify these effects only partially as their ability to store subglacial water is lacking.

  4. Hydrologic Scales, Cloud Variability, Remote Sensing, and Models: Implications for Forecasting Snowmelt and Streamflow

    Microsoft Academic Search

    James J. Simpson; Michael D. Dettinger; Frank Gehrke; Timothy J. McIntire; Gary L. Hufford

    2004-01-01

    Accurate prediction of available water supply from snowmelt is needed if the myriad of human, environmental, agricultural, and industrial demands for water are to be satisfied, especially given legislatively imposed conditions on its allocation. Robust retrievals of hydrologic basin model variables (e.g., insolation or areal extent of snow cover) provide several advantages over the current operational use of either point

  5. CORDEX - a treasure trove of open climate data for hydrological modelling

    NASA Astrophysics Data System (ADS)

    O'Rourke, Eleanor; Nikulin, Grigory; Kjellström, Erik

    2015-04-01

    The Coordinated Regional Downscaling Experiment (CORDEX) was initiated by the World Climate Research Programme (WCRP) to coordinate high-resolution Regional Climate Modelling and provide a set of regional climate projections for the majority of global land regions. Additionally making this data available, and importantly useable, to impact and adaptation communities was a fundamental goal. Phase I of CORDEX, which came to a close in November 2013, was successful in developing a framework in which scientists around the world adopted a common protocol to guide the development of high-resolution Regional Climate Model (RCM) and empirical statistical downscaling (ESD) projections, and the intercomparison of these projections, on each continent, with a particular focus on the African region. As a result of these intensive activities by groups across the globe more than 47000 quality checked open datasets are now freely available to users through the searchable Earth System Grid Federation (ESGF). The integration of this data into large scale hydrological modelling is in action within the Swedish Meteorological & Hydrological Institute (SMHI) exemplifying the great potential use of this resource to the hydrological community. The aim of CORDEX Phase II is to enhance the dialogue with end-users so as to meet the growing demand for tailored regional climate information. Here, greater interaction between the CORDEX and hydrological modelling community can only prove hugely beneficial leading to greater protection for those vulnerable to the impacts of a changing climate.

  6. Hydrological modelling of a small watershed using MIKE SHE for irrigation planning

    Microsoft Academic Search

    R. Singh; K. Subramanian; J. C. Refsgaard

    1999-01-01

    The physically based distributed modelling system, MIKE SHE, is used to simulate the hydrological water balance of a small watershed with the objective of developing the irrigation plan. Simulation is first conducted over 109 days, concentrating the attention on the main cropping season, i.e., kharif (Jul–Oct), and the average water balance is calculated. It is observed that in spite of

  7. Characteristics of concentrated flow hydraulics for rangeland ecosystems: implications for hydrologic modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concentrated flow is often the dominant source of water erosion following disturbance on rangeland. Because of the lack of studies that explain the hydraulics of concentrated flow on rangelands, cropland-based equations have typically been used for rangeland hydrology and erosion modeling, leading t...

  8. On noise specification in data assimilation schemes for improved flood forecasting using distributed hydrological models

    NASA Astrophysics Data System (ADS)

    Noh, S.; Rakovec, O.; Weerts, A.; Tachikawa, Y.

    2013-12-01

    While important advances have been achieved in flood forecasting, due to various uncertainties that originate from simulation models, observations, and forcing data, they are still insufficient to obtain accurate prediction results with the required lead times. To increase the certainty of the hydrological forecast, data assimilation (DA) may be utilized to consider or propagate all of these sources of uncertainty through the hydrological modelling chain embedded in a flood forecasting system. Although numerous sophisticated DA algorithms have been proposed to mitigate uncertainty, DA methods dealing with the correction of model inputs, states, and initial conditions are conducted in a rather empirical and subjective way, which may reduce credibility and transparency to operational forecasts. In this study, we investigate the effect of noise specification on the quality of hydrological forecasts via an advanced DA procedure using a distributed hydrological model driven by numerical weather predictions. The sequential DA procedure is based on (1) a multivariate rainfall ensemble generator, which provides spatial and temporal correlation error structures of input forcing and (2) lagged particle filtering to update past and current state variables simultaneously in a lag-time window to consider the response times of internal hydrologic processes. The strength of the proposed procedure is that it requires less subjectivity to implement DA compared to conventional methods using consistent and objectively-induced error models. The procedure is evaluated for streamflow forecasting of three flood events in two Japanese medium-sized catchments. The rainfall ensembles are derived from ground based rain gauge observations for the analysis step and numerical weather predictions for the forecast step. Sensitivity analysis is performed to assess the impacts of uncertainties coming from DA such as random walk state noise and different DA methods with/without objectively-induced rainfall uncertainty conditions. The results show that multivariate rainfall ensembles provide sound input perturbations and model states updated by lagged particle filtering produce improved streamflow forecasts in conjunction with fine-resolution numerical weather predictions.

  9. ADVANCING GREAT LAKES HYDROLOGICAL SCIENCE

    E-print Network

    ADVANCING GREAT LAKES HYDROLOGICAL SCIENCE THROUGH TARGETED BINATIONAL COLLABORATIVE RESEARCH by Andrew d. Gronewold And Vincent Fortin ImprovIng HydrologIcal modelIng predIctIons In tHe great lakes wh for advancing the state of the art in Great Lakes regional climate, hydrological, and hydrodynamic modeling when

  10. Assessment and evaluation of soil moisture in Iowa using hydrological modeling and observational data

    NASA Astrophysics Data System (ADS)

    Quintero, Felipe; Navarro, Walter; Mantilla, Ricardo; Niemeier, James; Ceynar, Dan; Krajewski, Witold; Cosh, Michael

    2015-04-01

    The data from soil moisture observed at the hillslope scale in several locations of Central and Eastern Iowa are compared with estimates of water content at the upper zone of the soil derived from a distributed hydrological model. Both observed and simulated data are available at fine temporal resolution. We analyze the adequacy of the hydrologic model structure to reproduce the processes that partition rainfall into soil moisture. The model uses a decomposition of the landscape into hillslopes and channel links. Runoff generation takes place at hillslopes accounting for soil properties, topography, and land use. The in-situ soil moisture data have not been used in model development and thus the comparison presents an interesting test of the model's ability. The rainfall data forcing the model are available from high-resolution radar-rainfall maps and/or rain gauge measurements located in the same hillslopes where the soil moisture probes are installed.

  11. Development and application of a modular watershed-scale hydrologic model using the object modeling system: runoff response evaluation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study reports on: 1) the integration of the European J2K model (an object-oriented, modular hydrological system for fully distributed simulation of the water balance in large watersheds) under the Object Modeling System (OMS) environmental modeling framework; and 2) evaluation of OMS-J2K perfor...

  12. [Present state and the future direction of HBV vaccine].

    PubMed

    Mizokami, Masashi; Sugiyama, Masaya

    2012-06-01

    Hepatitis B virus (HBV) prevention program in Japan is considered one of the most successful and effective public anti-counter programs to HBV infection. However, almost all of population under twenty-five years is extremely susceptibility for HBV infection. HBV genotype A, which was not in Japan and has been from western countries, is increasing in chronic hepatitis B patients in Japan as a consequence of acute hepatitis B spreading in the younger generation through promiscuous sexual transmitted infection and the characteristics of HBV genotype A is a prolonged high HBVDNA viremia compared with other HBV genotypes. These data have strongly indicated that the main transmission route of HBV in Japan has been changed to a horizontal infection with sexual transmitted disease from perinatal transmission from HBsAg positive mothers. Although the HBV vaccine has tipped the balance in our favor, newly issues of HBV vaccine has been arisen such as vaccine escape mutant, efficacy and potency for the prevention of HBV infection, especially different HBV genotypes, HBV reactivation on the patients with HBsAg negative and anti-HBs antibody positive under systemic chemotherapy, and universal vaccination or selective vaccination and so on. PMID:23189826

  13. A Four-Stage Hybrid Model for Hydrological Time Series Forecasting

    PubMed Central

    Di, Chongli; Yang, Xiaohua; Wang, Xiaochao

    2014-01-01

    Hydrological time series forecasting remains a difficult task due to its complicated nonlinear, non-stationary and multi-scale characteristics. To solve this difficulty and improve the prediction accuracy, a novel four-stage hybrid model is proposed for hydrological time series forecasting based on the principle of ‘denoising, decomposition and ensemble’. The proposed model has four stages, i.e., denoising, decomposition, components prediction and ensemble. In the denoising stage, the empirical mode decomposition (EMD) method is utilized to reduce the noises in the hydrological time series. Then, an improved method of EMD, the ensemble empirical mode decomposition (EEMD), is applied to decompose the denoised series into a number of intrinsic mode function (IMF) components and one residual component. Next, the radial basis function neural network (RBFNN) is adopted to predict the trend of all of the components obtained in the decomposition stage. In the final ensemble prediction stage, the forecasting results of all of the IMF and residual components obtained in the third stage are combined to generate the final prediction results, using a linear neural network (LNN) model. For illustration and verification, six hydrological cases with different characteristics are used to test the effectiveness of the proposed model. The proposed hybrid model performs better than conventional single models, the hybrid models without denoising or decomposition and the hybrid models based on other methods, such as the wavelet analysis (WA)-based hybrid models. In addition, the denoising and decomposition strategies decrease the complexity of the series and reduce the difficulties of the forecasting. With its effective denoising and accurate decomposition ability, high prediction precision and wide applicability, the new model is very promising for complex time series forecasting. This new forecast model is an extension of nonlinear prediction models. PMID:25111782

  14. Modelling past hydrology of an interfluve area in the Campine region (NE Belgium)

    NASA Astrophysics Data System (ADS)

    Leterme, Bertrand; Beerten, Koen; Gedeon, Matej; Vandersteen, Katrijn

    2015-04-01

    This study aims at hydrological model verification of a small lowland interfluve area (18.6 km²) in NE Belgium, for conditions that are different than today. We compare the current state with five reference periods in the past (AD 1500, 1770, 1854, 1909 and 1961) representing important stages of landscape evolution in the study area. Historical information and proxy data are used to derive conceptual model features and boundary conditions specific to each period: topography, surface water geometry (canal, drains and lakes), land use, soils, vegetation and climate. The influence of landscape evolution on the hydrological cycle is assessed using numerical simulations of a coupled unsaturated zone - groundwater model (HYDRUS-MODFLOW). The induced hydrological changes are assessed in terms of groundwater level, recharge, evapotranspiration, and surface water discharge. HYDRUS-MODFLOW coupling allows including important processes such as the groundwater contribution to evapotranspiration. Major land use change occurred between AD 1854 and 1909, with about 41% of the study area being converted from heath to coniferous forest, together with the development of a drainage network. Results show that this led to a significant decrease of groundwater recharge and lowering of the groundwater table. A limitation of the study lies in the comparison of simulated past hydrology with appropriate palaeo-records. Examples are given as how some indicators (groundwater head, swamp zones) can be used to tend to model validation. Quantifying the relative impact of land use and climate changes requires running sensitivity simulations where the models using alternative land use are run with the climate forcing of other periods. A few examples of such sensitivity runs are presented in order to compare the influence of land use and climate change on the study area hydrology.

  15. Remote sensing and hydrologic modeling of arid watersheds: A scale analysis: Progress report

    SciTech Connect

    Not Available

    1988-01-01

    The ultimate goal of this multiyear research effort is to model long-term (10/sup 2/--10/sup 4/ yrs), cut and fill cycles in arid region fluvial systems (arroyos). Historic and geologic (late Quaternary) data bases indicate that arid region fluvial systems have oscillated between periods of pronounced aggradation and degradation. This cyclic behavior has affected both water and sediment discharge from arid watersheds as well as ecosystem habitats along hillslopes and valley bottoms. One of the primary causes that has been proposed for this cyclic activity is climatic change for gradual (glacial-interglacial) and catastrophic (volcanic eruptions, el Nino) rates of climatic change on a global scale. The immediate goal of this multiyear research effort is to modify existing numeric hydrologic models (SPUR, KINEROS) which utilize as input multilayered, co-registered remotely sensed data for the prediction of surface hydrology and sediment erosion, transport and deposition in arid region watersheds. It is hypothesized that different types of co-registered, remotely sensed data including digital elevation data sets (DEDS), multispectral scanner (TM, SPOT), and thermal infrared multispectral scanner (TIMS) can be used in conjunction with limited ground truth data to predict values of input parameters for numeric watershed hydrology models and thus to compute watershed hydrologic and sedimentologic characteristics.

  16. Multiscale Snow/Icemelt Discharge Simulations into Alpine Reservoirs: adding Glacier Dynamics to a Hydrological Model

    NASA Astrophysics Data System (ADS)

    Schueller, Felix; Förster, Kristian; Hanzer, Florian; Huttenlau, Matthias; Marzeion, Ben; Strasser, Ulrich; Achleitner, Stefan; Kirnbauer, Robert

    2015-04-01

    Glacier and snow runoff in high alpine regions is an essential process in hydrological research for its high relevance on lower altitude areas and hydro-power generation. MUSICALS II (Multiscale Snow/Icemelt Discharge Simulations into Alpine Reservoirs) seeks to identify and quantify water availability and runoff in alpine headwater catchments. The focus is on future changes due to glacier retreat, altering the multi-day and seasonal runoff available for hydropower operations. Our aim is to investigate and improve runoff forecasts by coupling the semi-distributed hydrological model HQSim with a simple glacier evolution model. The glacier model MMBM (Marzeion Mass Balance Model) with its statistical nature allows for fast modelling of the dynamical properties of glaciers. We present the design of the coupled hydrological application for different hydro power headwater catchments in Tyrol. The capabilities of the glacier model to simulate the selected glaciers is shown. Simulated discharge with the original and the coupled model are compared to downstream gauge measurements. Using the multi-objective optimization algorithm AMALGAM (A Multi-ALgorithm, Genetically Adaptive Multiobjective model), we optimize the glacier module parameters fully automatically. The results show the improvements in runoff modelling for past periods, when altering of glaciated catchment parts is considered. This indicates consideration of this process is mandatory for simulating future developments.

  17. Step wise, multiple objective calibration of a hydrologic model for a snowmelt dominated basin

    USGS Publications Warehouse

    Hay, L.E.; Leavesley, G.H.; Clark, M.P.; Markstrom, S.L.; Viger, R.J.; Umemoto, M.

    2006-01-01

    The ability to apply a hydrologic model to large numbers of basins for forecasting purposes requires a quick and effective calibration strategy. This paper presents a step wise, multiple objective, automated procedure for hydrologic model calibration. This procedure includes the sequential calibration of a model's simulation of solar radiation (SR), potential evapotranspiration (PET), water balance, and daily runoff. The procedure uses the Shuffled Complex Evolution global search algorithm to calibrate the U.S. Geological Survey's Precipitation Runoff Modeling System in the Yampa River basin of Colorado. This process assures that intermediate states of the model (SR and PET on a monthly mean basis), as well as the water balance and components of the daily hydrograph are simulated, consistently with measured values.

  18. DUAL STATE-PARAMETER UPDATING SCHEME ON A CONCEPTUAL HYDROLOGIC MODEL USING SEQUENTIAL MONTE CARLO FILTERS

    NASA Astrophysics Data System (ADS)

    Noh, Seong Jin; Tachikawa, Yasuto; Shiiba, Michiharu; Kim, Sunmin

    Applications of data assimilation techniques have been widely used to improve upon the predictability of hydrologic modeling. Among various data assimilation techniques, sequential Monte Carlo (SMC) filters, known as "particle filters" provide the capability to handle non-linear and non-Gaussian state-space models. This paper proposes a dual state-parameter updating scheme (DUS) based on SMC methods to estimate both state and parameter variables of a hydrologic model. We introduce a kernel smoothing method for the robust estimation of uncertain model parameters in the DUS. The applicability of the dual updating scheme is illustrated using the implementation of the storage function model on a middle-sized Japanese catchment. We also compare performance results of DUS combined with various SMC methods, such as SIR, ASIR and RPF.

  19. Hydrologic process simulation of a semiarid, endoreic catchment in Sahelian West Niger : 2. Model calibration and uncertainty characterization

    E-print Network

    Boyer, Edmond

    The Sahel has been subject to sharp changes in climatic and environmental conditions since the late sixties1 Hydrologic process simulation of a semiarid, endoreic catchment in Sahelian West Niger : 2. Model, Pages 244-261 also available online at www.sciencedirect.com #12;2 Hydrologic process simulation

  20. Observatories, think tanks, and community models in the hydrologic and environmental sciences: How does it affect me?

    Microsoft Academic Search

    Thomas Torgersen

    2006-01-01

    Multiple issues in hydrologic and environmental sciences are now squarely in the public focus and require both government and scientific study. Two facts also emerge: (1) The new approach being touted publicly for advancing the hydrologic and environmental sciences is the establishment of community-operated “big science” (observatories, think tanks, community models, and data repositories). (2) There have been important changes

  1. Observatories, think tanks, and community models in the hydrologic and environmental sciences: How does it affect me?

    Microsoft Academic Search

    Thomas Torgersen

    2006-01-01

    Multiple issues in hydrologic and environmental sciences are now squarely in the public focus and require both government and scientific study. Two facts also emerge: (1) The new approach being touted publicly for advancing the hydrologic and environmental sciences is the establishment of community-operated ``big science'' (observatories, think tanks, community models, and data repositories). (2) There have been important changes

  2. Development of a coupled model of a distributed hydrological model and a rice growth model for optimizing irrigation schedule

    NASA Astrophysics Data System (ADS)

    Tsujimoto, Kumiko; Homma, Koki; Koike, Toshio; Ohta, Tetsu

    2013-04-01

    A coupled model of a distributed hydrological model and a rice growth model was developed in this study. The distributed hydrological model used in this study is the Water and Energy Budget-based Distributed Hydrological Model (WEB-DHM) developed by Wang et al. (2009). This model includes a modified SiB2 (Simple Biosphere Model, Sellers et al., 1996) and the Geomorphology-Based Hydrological Model (GBHM) and thus it can physically calculate both water and energy fluxes. The rice growth model used in this study is the Simulation Model for Rice-Weather relations (SIMRIW) - rainfed developed by Homma et al. (2009). This is an updated version of the original SIMRIW (Horie et al., 1987) and can calculate rice growth by considering the yield reduction due to water stress. The purpose of the coupling is the integration of hydrology and crop science to develop a tool to support decision making 1) for determining the necessary agricultural water resources and 2) for allocating limited water resources to various sectors. The efficient water use and optimal water allocation in the agricultural sector are necessary to balance supply and demand of limited water resources. In addition, variations in available soil moisture are the main reasons of variations in rice yield. In our model, soil moisture and the Leaf Area Index (LAI) are calculated inside SIMRIW-rainfed so that these variables can be simulated dynamically and more precisely based on the rice than the more general calculations is the original WEB-DHM. At the same time by coupling SIMRIW-rainfed with WEB-DHM, lateral flow of soil water, increases in soil moisture and reduction of river discharge due to the irrigation, and its effects on the rice growth can be calculated. Agricultural information such as planting date, rice cultivar, fertilization amount are given in a fully distributed manner. The coupled model was validated using LAI and soil moisture in a small basin in western Cambodia (Sangker River Basin). This basin is mostly rainfed paddy so that irrigation scheme was firstly switched off. Several simulations with varying irrigation scheme were performed to determine the optimal irrigation schedule in this basin.

  3. Sensitivity of Flow Uncertainty to Radar Rainfall Uncertainty in the Context of Operational Distributed Hydrologic Modeling

    NASA Astrophysics Data System (ADS)

    Carpenter, T. M.; Georgakakos, K. P.; Georgakakos, K. P.

    2001-12-01

    The current study focuses on the sensitivity of distributed model flow forecast uncertainty to the uncertainty in the radar rainfall input. Various studies estimate a 30 to 100% uncertainty in radar rainfall estimates from the operational NEXRAD radars. This study addresses the following questions: How does this uncertainty in rainfall input impact the flow simulations produced by a hydrologic model? How does this effect compare to the uncertainty in flow forecasts resulting from initial condition and model parametric uncertainty? The hydrologic model used, HRCDHM, is a catchment-based, distributed hydrologic model and accepts hourly precipitation input from the operational WSR-88D weather radar. A GIS is used to process digital terrain data, delineate sub-catchments of a given large watershed, and supply sub-catchment characteristics (subbasin area, stream length, stream slope and channel-network topology) to the hydrologic model components. HRCDHM uses an adaptation of the U.S. NWS operational Sacramento soil moisture accounting model to produce runoff for each sub-catchment within the larger study watershed. Kinematic or Muskingum-Cunge channel routing is implemented to combine and route sub-catchment flows through the channel network. Available spatial soils information is used to vary hydrologic model parameters from sub-catchment to sub-catchment. HRCDHM was applied to the 2,500 km2 Illinois River watershed in Arkansas and Oklahoma with outlet at Tahlequah, Oklahoma. The watershed is under the coverage of the operational WSR-88D radar at Tulsa, Oklahoma. For distributed modeling, the watershed area has been subdivided into sub-catchments with an average area of 80km2. Flow simulations are validated at various gauged locations within the watershed. A Monte Carlo framework was used to assess the sensitivity of the simulated flows to uncertainty in radar input for different radar error distributions (uniform or exponential), and to make comparisons to the flow sensitivity under parametric input uncertainty. Initial results indicate that (a) the distributed model reproduces well the hourly observed flows at the gauged sites, (b) flow sensitivity to radar input uncertainty is scale dependent, and (c) the sensitivity of the range of simulated flows to the expected uncertainty in certain hydrologic parameters is comparable to that resulting from the expected uncertainty in radar rainfall input

  4. Modeling the hydrological significance of wetland restoration scenarios.

    PubMed

    Martinez-Martinez, Edwin; Nejadhashemi, A Pouyan; Woznicki, Sean A; Love, Bradley J

    2014-01-15

    Wetlands provide multiple socio-economic benefits, among them mitigating flood through short- and long-term water storage functions and assisting with reduction of downstream flood peaks. However, their effectiveness in controlling floods is dictated by wetland size and distribution within a watershed. Due to the complexity of wetland hydrological processes at the watershed scale, the Soil and Water Assessment Tool (SWAT) was used to study the impact of wetland restoration on streamflow rates and peaks in the Shiawassee River watershed of Michigan. Wetland restoration scenarios were developed based on combinations of wetland area (50, 100, 250, and 500 ha) and wetland depth (15, 30, 61, and 91 cm). Increasing wetland area, rather than depth, had a greater impact on long-term average daily streamflow. Wetland implementation resulted in negligible reductions in daily peak flow rates and frequency of peak flow events at the watershed outlet. In developing high impact areas for wetland restoration, similar locations were identified for reduction of subbasin and watershed outlet streamflow. However, the best combinations of area/depth differed depending on the goal of the restoration plan. PMID:24374168

  5. Evaluating the use of 'goodness-of-fit' measures in hydrologic and hydroclimatic model validation

    USGS Publications Warehouse

    Legates, D.R.; McCabe, G.J., Jr.

    1999-01-01

    Correlation and correlation-based measures (e.g., the coefficient of determination) have been widely used to evaluate the 'goodness-of-fit' of hydrologic and hydroclimatic models. These measures are oversensitive to extreme values (outliers) and are insensitive to additive and proportional differences between model predictions and observations. Because of these limitations, correlation-based measures can indicate that a model is a good predictor, even when it is not. In this paper, useful alternative goodness-of-fit or relative error measures (including the coefficient of efficiency and the index of agreement) that overcome many of the limitations of correlation-based measures are discussed. Modifications to these statistics to aid in interpretation are presented. It is concluded that correlation and correlation-based measures should not be used to assess the goodness-of-fit of a hydrologic or hydroclimatic model and that additional evaluation measures (such as summary statistics and absolute error measures) should supplement model evaluation tools.Correlation and correlation-based measures (e.g., the coefficient of determination) have been widely used to evaluate the `goodness-of-fit' of hydrologic and hydroclimatic models. These measures are oversensitive to extreme values (outliers) and are insensitive to additive and proportional differences between model predictions and observations. Because of these limitations, correlation-based measures can indicate that a model is a good predictor, even when it is not. In this paper, useful alternative goodness-of-fit or relative error measures (including the coefficient of efficiency and the index of agreement) that overcome many of the limitations of correlation-based measures are discussed. Modifications to these statistics to aid in interpretation are presented. It is concluded that correlation and correlation-based measures should not be used to assess the goodness-of-fit of a hydrologic or hydroclimatic model and that additional evaluation measures (such as summary statistics and absolute error measures) should supplement model evaluation tools.

  6. Modeling 3D soil and sediment distributions for assessing catchment structure and hydrological feedbacks

    NASA Astrophysics Data System (ADS)

    Maurer, Thomas; Brück, Yasemine; Hinz, Christoph; Gerke, Horst H.

    2015-04-01

    Structural heterogeneity, namely the spatial distribution of soils and sediments (represented by mineral particles), characterizes catchment hydrological behavior. In natural catchments, local geology and the specific geomorphic processes determine the characteristics and spatial distribution of structures. In constructed catchments, structural features are determined primarily by the construction processes and the geological origin of the parent material. Objectives are scenarios of 3D catchment structures in form of complete 3D description of soil hydraulic properties generated from the knowledge of the formation processes. The constructed hydrological catchment 'Hühnerwasser' (Lower Lusatia, Brandenburg, Germany) was used for the calibration and validation of model results due to its well-known conditions. For the modelling of structural features, a structure generator was used to model i) quasi-deterministic sediment distributions using input data from a geological model of the parent material excavation site; ii) sediment distributions that are conditioned to measurement data from soil sampling; and iii) stochastic component sediment distributions. All three approaches allow a randomization within definable limits. Furthermore, the spoil cone / spoil ridge orientation, internal layering, surface compaction and internal spoil cone compaction were modified. These generated structural models were incorporated in a gridded 3D volume model constructed with the GOCAD software. For selected scenarios, the impact of structure variation was assessed by hydrological modelling with HYDRUS 2D/3D software. For that purpose, 3D distributions of soil hydraulic properties were estimated based on generated sediment properties using adapted pedotransfer functions. Results from the hydrological model were compared them to measured discharges from the catchment. The impact of structural feature variation on flow behaviour was analysed by comparing different simulation scenarios. The established initial sediment distributions provide a basis for the consecutive modelling of feedbacks between surface and subsurface water flow and changes in soil properties, e.g. by using a landscape evolution model. The results should allow conclusions about the effect of different initial structural setups on the further dynamic landscape development at catchment scale.

  7. PREDICTIVE UNCERTAINTY IN HYDROLOGIC AND WATER QUALITY MODELING: APPROACHES, APPLICATION TO ENVIRONMENTAL MANAGEMENT, AND FUTURE CHALLENGES (PRESENTATION)

    EPA Science Inventory

    Extant process-based hydrologic and water quality models are indispensable to water resources planning and environmental management. However, models are only approximations of real systems and often calibrated with incomplete and uncertain data. Reliable estimates, or perhaps f...

  8. Molecular Epidemiology of Hepatitis B Virus (HBV) Genotypes and Serotypes in Patients with Chronic HBV Infection in Korea

    Microsoft Academic Search

    Hong Kim; Young Mee Jee; Byung-Cheol Song; Jung Woo Shin; Soo Hyun Yang; Ho-Suk Mun; Hyun-Ju Kim; Eun-Ju Oh; Jung-Hwan Yoon; Yoon-Jun Kim; Hyo-Suk Lee; Eung-Soo Hwang; Chang-Yong Cha; Yoon-Hoh Kook; Bum-Joon Kim

    2007-01-01

    Objectives: Although hepatitis B virus (HBV) is endemic to Korea, no large-scale survey of HBV genotypes and serotypes based on sequence analysis has been performed. Methods: In the present study, we genotyped and serotyped HBV strains from 209 patients in two Korean regions, Seoul (107 patients) and Jeju (102 patients), an island off the southeastern Korean coast. Analyses were conducted

  9. A novel HBV DNA vaccine based on T cell epitopes and its potential therapeutic effect in HBV transgenic mice

    Microsoft Academic Search

    Xiangming Li; Xiaofeng Yang; Yunyun Jiang; Jing Liu

    2005-01-01

    DNA vaccination represents a novel therapeutic strategy for chronic hepatitis B virus (HBV) infection. Recently, some HBV DNA vaccines have been used in the preliminary clinical trials and exhibited exciting results in chronic HBV carriers. But these vaccines only encoded the single viral antigen, the S or the PreS2\\/S antigen. In this study, we designed a polytope DNA vaccine encoding

  10. Constraining basal hydrology with model inversions of basal friction using new InSAR surface velocities.

    NASA Astrophysics Data System (ADS)

    Larour, E.; Rignot, E.; Seroussi, H.; Morlighem, M.

    2012-04-01

    Constraining ice flow models for continental ice sheets such as Antarctica or Greenland can be difficult, especially regarding the specification of basal friction at the ice/bed interface. Historically, two approches have been taken: 1) model the basal hydrology of the ice sheet, and relate the resulting basal water pressure to the basal drag coefficient and 2) invert for the basal drag coefficient using InSAR surface velocities, and infer the resulting basal hydrology. Here, we use both approaches within the Ice Sheet System Model (ISSM), the JPL/UCI developed ice flow model, for which we have developed a new hydrological model based on LeBrocq et al, 2009. We compare this model against a large scale inversion of Antarctica's basal drag coefficient using new InSAR surface velocities from Rignot et al 2011. We discuss the potential for this model to improve constraints on basal friction evolution, and implications for projections of ice flow dynamics in a changing climate. We also discuss relevance for calibrating thermal models of Antarctica. This work was performed at the California Institute of Technology's Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration's Cryosphere Science Program.

  11. High Resolution Integrated Hydrologic Modeling for Water Resource Management: Tahoe Basin Case Study

    NASA Astrophysics Data System (ADS)

    Rajagopal, S.; Niswonger, R. G.; Huntington, J. L.; Gardner, M.; Morton, C.; Maples, S.; Reeves, D. M.; Pohll, G.

    2014-12-01

    Water resources in the high altitude, snow-dominated Tahoe basin are susceptible to long-term climate change and extreme climatic events due to large inter-annual climate variations. Lake Tahoe and its contributing watersheds exhibit high climatic (precipitation, temperature) and hydrologic (streamflow, evaporation) variation that exert significant control over regional water supply on annual and sub-annual timescales. To adequately quantify these controls, a high resolution (300m) physically based integrated surface and groundwater model, GSFLOW, of the Tahoe basin has been developed to identify key hydrologic mechanisms that explain recent changes in water resources of the region. The model is parameterized using geographical datasets and maintains a balance between (a) accurate representation of spatial (e.g., geology, streams, and topography) and hydrologic (groundwater, stream, lake, and wetland flows and storages) features, and (b) computational efficiency, which is a necessity for exploring critical vulnerabilities of water-supplies in the region. The calibrated model reproduces multiple observations of streamflow, snow water equivalent, satellite derived snow covered area, lake stage, and groundwater head. Climate input uncertainty was significantly decreased in the model through incorporating additional precipitation station data and helped improve model simulations of observed fluxes more than adjusting model parameters alone. The model simulates fluxes at the outlet of the watershed, but is also consistent at simulating streamflow at internal nodes. This integrated modeling framework helped assess both surface and groundwater resources in a coupled manner in the Tahoe basin.

  12. Intercomparison of lumped versus distributed hydrologic model ensemble simulations on operational forecast scales

    NASA Astrophysics Data System (ADS)

    Carpenter, Theresa M.; Georgakakos, Konstantine P.

    2006-09-01

    SummaryDistributed hydrologic models, with the capability to incorporate a variety of spatially-varying land characteristics and precipitation forcing data, are thought to have great potential for improving hydrologic forecasting. However, uncertainty in the high resolution estimates of precipitation and model parameters may diminish potential gains in prediction accuracy achieved by accounting for the inherent spatial variability. This paper develops a probabilistic methodology for comparing ensemble streamflow simulations from hydrologic models with high- and low-spatial resolution under uncertainty in both precipitation input and model parameters. The methodology produces ensemble streamflow simulations using well calibrated hydrologic models, and evaluates the distinctiveness of the ensembles from the high- and low-resolution models for the same simulation point. The study watersheds are of the scale for which operational streamflow forecasts are issued (order of a few 1000 km 2), and the models employed are adaptations of operational models used by the US National Weather Service. A high-resolution (i.e., spatially distributed) model and a low-resolution (i.e., spatially lumped) model were used to simulate selected events for each of two study watersheds located in the southern Central Plains of the US using operational-quality data to drive the models. Ensemble streamflow simulations were generated within a Monte Carlo framework using models for uncertainty in radar-based precipitation estimates and in the hydrologic soil model parameters. The Kolmogorov-Smirnov test was then employed to assess whether the ensemble flow simulations at the time of observed peak flow from the high- and low-resolution models can be distinguished with high confidence. Further assessment evaluated the model performance in terms of reproducing the observed peak flow magnitude and timing. Most of the selected events showed the high- and low-resolution models produced statistically different flow ensembles for the peak flow. Furthermore, the high-resolution model ensemble simulations consistently had higher frequency of occurrence within specified bounds of the observed peak flow magnitude and timing.

  13. Inverse Modeling of Hydrologic Parameters Using Surface Flux and Runoff Observations in the Community Land Model

    SciTech Connect

    Sun, Yu; Hou, Zhangshuan; Huang, Maoyi; Tian, Fuqiang; Leung, Lai-Yung R.

    2013-12-10

    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. Two inversion strategies, the deterministic least-square fitting and stochastic Markov-Chain Monte-Carlo (MCMC) - Bayesian inversion approaches, are evaluated by applying them to CLM4 at selected sites. 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 least-square fitting provides little improvements in the model simulations but the sampling-based stochastic inversion approaches are consistent - as more information comes in, the predictive intervals of the calibrated parameters become narrower and the misfits between the calculated and observed responses decrease. 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 the 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.

  14. Hydroclimatology of Lake Victoria region using hydrologic model and satellite remote sensing data

    NASA Astrophysics Data System (ADS)

    Khan, S. I.; Adhikari, P.; Hong, Y.; Vergara, H.; Adler, R. F.; Policelli, F.; Irwin, D.; Korme, T.; Okello, L.

    2011-01-01

    Study of hydro-climatology at a range of temporal scales is important in understanding and ultimately mitigating the potential severe impacts of hydrological extreme events such as floods and droughts. Using daily in-situ data over the last two decades combined with the recently available multiple-years satellite remote sensing data, we analyzed and simulated, with a distributed hydrologic model, the hydro-climatology in Nzoia, one of the major contributing sub-basins of Lake Victoria in the East African highlands. The basin, with a semi arid climate, has no sustained base flow contribution to Lake Victoria. The short spell of high discharge showed that rain is the prime cause of floods in the basin. There is only a marginal increase in annual mean discharge over the last 21 years. The 2-, 5- and 10- year peak discharges, for the entire study period showed that more years since the mid 1990's have had high peak discharges despite having relatively less annual rain. The study also presents the hydrologic model calibration and validation results over the Nzoia basin. The spatiotemporal variability of the water cycle components were quantified using a hydrologic model, with in-situ and multi-satellite remote sensing datasets. The model is calibrated using daily observed discharge data for the period between 1985 and 1999, for which model performance is estimated with a Nash Sutcliffe Efficiency (NSCE) of 0.87 and 0.23% bias. The model validation showed an error metrics with NSCE of 0.65 and 1.04% bias. Moreover, the hydrologic capability of satellite precipitation (TRMM-3B42 V6) is evaluated. In terms of reconstruction of the water cycle components the spatial distribution and time series of modeling results for precipitation and runoff showed considerable agreement with the monthly model runoff estimates and gauge observations. Runoff values responded to precipitation events that occurred across the catchment during the wet season from March to early June. The spatially distributed model inputs, states, and outputs, were found to be useful for understanding the hydrologic behavior at the catchment scale. The monthly peak runoff is observed in the months of April, May and November. The analysis revealed a linear relationship between rainfall and runoff for both wet and dry seasons. Satellite precipitation forcing data showed the potential to be used not only for the investigation of water balance but also for addressing issues pertaining to sustainability of the resources at the catchment scale.

  15. Development of Conceptual Benchmark Models to Evaluate Complex Hydrologic Model Calibration in Managed Basins Using Python

    NASA Astrophysics Data System (ADS)

    Hughes, J. D.; White, J.

    2013-12-01

    For many numerical hydrologic models it is a challenge to quantitatively demonstrate that complex models are preferable to simpler models. Typically, a decision is made to develop and calibrate a complex model at the beginning of a study. The value of selecting a complex model over simpler models is commonly inferred from use of a model with fewer simplifications of the governing equations because it can be time consuming to develop another numerical code with data processing and parameter estimation functionality. High-level programming languages like Python can greatly reduce the effort required to develop and calibrate simple models that can be used to quantitatively demonstrate the increased value of a complex model. We have developed and calibrated a spatially-distributed surface-water/groundwater flow model for managed basins in southeast Florida, USA, to (1) evaluate the effect of municipal groundwater pumpage on surface-water/groundwater exchange, (2) investigate how the study area will respond to sea-level rise, and (3) explore combinations of these forcing functions. To demonstrate the increased value of this complex model, we developed a two-parameter conceptual-benchmark-discharge model for each basin in the study area. The conceptual-benchmark-discharge model includes seasonal scaling and lag parameters and is driven by basin rainfall. The conceptual-benchmark-discharge models were developed in the Python programming language and used weekly rainfall data. Calibration was implemented with the Broyden-Fletcher-Goldfarb-Shanno method available in the Scientific Python (SciPy) library. Normalized benchmark efficiencies calculated using output from the complex model and the corresponding conceptual-benchmark-discharge model indicate that the complex model has more explanatory power than the simple model driven only by rainfall.

  16. Evaluating the Application of Multi-Satellite Observations in Hydrologic Modeling

    NASA Technical Reports Server (NTRS)

    Bolten, John

    2011-01-01

    When monitoring local or regional hydrosphere dynamics for applications such as agricultural productivity or drought and flooding events, it is necessary to have accurate, high-resolution estimates of terrestrial water and energy storages. Though in-situ observations provide reliable estimates of hydrologic states and fluxes, they are only capable of accurately capturing the dynamics at relatively discrete points in space and time, which makes them inadequate for characterizing the variability of the water budget across scales. In contrast, satellite-based remote sensing is ideal for providing observations of hydrological states and fluxes because it provides spatially-distributed observations at spatial and temporal scales required for regional land surface process modeling. Due to the continued progress in algorithm development and emerging satellite technology, we now have near-real time monitoring of several components of the water cycle including precipitation, soil moisture, lake and river height, terrestrial water storage, snow cover, and evapotranspiration. As these data become more readily available, their application to hydrologic modeling is becoming more common, however there remains little consensus on the most appropriate method for optimal integration and evaluation in regard to hydrological applications. Here we present two case studies operationally applying several remotely sensed products from AMSR-E, GRACE, and MODIS and discuss assimilation strategies, ease of integration and interpretation, and methods for quantifying the success of the application methodology.

  17. Transport of fluorobenzoate tracers in a vegetated hydrologic control volume: 2. Theoretical inferences and modeling

    NASA Astrophysics Data System (ADS)

    Queloz, Pierre; Carraro, Luca; Benettin, Paolo; Botter, Gianluca; Rinaldo, Andrea; Bertuzzo, Enrico

    2015-04-01

    A theoretical analysis of transport in a controlled hydrologic volume, inclusive of two willow trees and forced by erratic water inputs, is carried out contrasting the experimental data described in a companion paper. The data refer to the hydrologic transport in a large lysimeter of different fluorobenzoic acids seen as tracers. Export of solute is modeled through a recently developed framework which accounts for nonstationary travel time distributions where we parameterize how output fluxes (namely, discharge and evapotranspiration) sample the available water ages in storage. The relevance of this work lies in the study of hydrologic drivers of the nonstationary character of residence and travel time distributions, whose definition and computation shape this theoretical transport study. Our results show that a large fraction of the different behaviors exhibited by the tracers may be charged to the variability of the hydrologic forcings experienced after the injection. Moreover, the results highlight the crucial, and often overlooked, role of evapotranspiration and plant uptake in determining the transport of water and solutes. This application also suggests that the ways evapotranspiration selects water with different ages in storage can be inferred through model calibration contrasting only tracer concentrations in the discharge. A view on upscaled transport volumes like hillslopes or catchments is maintained throughout the paper.

  18. Liver type I regulatory T cells suppress germinal center formation in HBV-tolerant mice.

    PubMed

    Xu, Long; Yin, Wenwei; Sun, Rui; Wei, Haiming; Tian, Zhigang

    2013-10-15

    The liver plays a critical role in inducing systemic immune tolerance, for example, during limiting hypersensitivity to food allergy and in rendering acceptance of allotransplant or even hepatotropic pathogens. We investigated the unknown mechanisms of liver tolerance by using an established hepatitis B virus (HBV)-carrier mouse model, and found that these mice exhibited an antigen-specific tolerance toward peripheral HBsAg vaccination, showing unenlarged draining lymph node (DLN), lower number of germinal centers (GC), and inactivation of GC B cells and follicular T helper (Tfh) cells. Both in vivo and in vitro immune responses toward HBsAg were suppressed by mononuclear cells from HBV-carrier mice, which were CD4(+) Foxp3(-) type 1 regulatory T (Tr1)-like cells producing IL-10. Using recipient Rag1(-/-) mice, hepatic Tr1-like cells from day 7 of HBV-persistent mice acquired the ability to inhibit anti-HBV immunity 3 d earlier than splenic Tr1-like cells, implying that hepatic Tr1-like cells were generated before those in spleen. Kupffer cell depletion or IL-10 deficiency led to impairment of Tr1-like cell generation, along with breaking HBV persistence. The purified EGFP(+)CD4(+) T cells (containing Tr1-like cells) from HBV-carrier mice trafficked in higher numbers to DLN in recipient mice after HBsAg vaccination, and subsequently inactivated both Tfh cells and GC B cells via secreting IL-10, resulting in impaired GC formation and anti-HB antibody production. Thus, our results indicate Tr1-like cells migrate from the liver to the DLN and inhibit peripheral anti-HBV immunity by negatively regulating GC B cells and Tfh cells. PMID:24089450

  19. Framework for Understanding Structural Errors (FUSE): a modular framework to diagnose differences between hydrological models

    USGS Publications Warehouse

    Clark, Martyn P.; Slater, Andrew G.; Rupp, David E.; Woods, Ross A.; Vrugt, Jasper A.; Gupta, Hoshin V.; Wagener, Thorsten; Hay, Lauren E.

    2008-01-01

    The problems of identifying the most appropriate model structure for a given problem and quantifying the uncertainty in model structure remain outstanding research challenges for the discipline of hydrology. Progress on these problems requires understanding of the nature of differences between models. This paper presents a methodology to diagnose differences in hydrological model structures: the Framework for Understanding Structural Errors (FUSE). FUSE was used to construct 79 unique model structures by combining components of 4 existing hydrological models. These new models were used to simulate streamflow in two of the basins used in the Model Parameter Estimation Experiment (MOPEX): the Guadalupe River (Texas) and the French Broad River (North Carolina). Results show that the new models produced simulations of streamflow that were at least as good as the simulations produced by the models that participated in the MOPEX experiment. Our initial application of the FUSE method for the Guadalupe River exposed relationships between model structure and model performance, suggesting that the choice of model structure is just as important as the choice of model parameters. However, further work is needed to evaluate model simulations using multiple criteria to diagnose the relative importance of model structural differences in various climate regimes and to assess the amount of independent information in each of the models. This work will be crucial to both identifying the most appropriate model structure for a given problem and quantifying the uncertainty in model structure. To facilitate research on these problems, the FORTRAN-90 source code for FUSE is available upon request from the lead author.

  20. Future Projections for Southern High Plains Agriculture Using Coupled Economic and Hydrologic Models and Climate Variability

    NASA Astrophysics Data System (ADS)

    Rainwater, K.; Tewari, R.; Willis, D.; Stovall, J.; Hayhoe, K.; Hernandez, A.; Mauget, S. A.; Leiker, G.; Johnson, J.

    2013-12-01

    The objective of the project was to evaluate the hypothesis that predicted climate change will affect the useful life of the Ogallala aquifer in the Southern High Plains (SHP) through its impact on the amount of irrigation withdrawals, and thus affect the yields and economic costs and net income. A ninety-year time frame has been considered, although the research team recognizes that long-term predictions of crop prices and selections are perhaps even more uncertain than long-term weather projections. Previous work by the research team recently demonstrated the development of regionally downscaled climate projections for the SHP. Quantitative projections of precipitation, potential evaporation, and temperature trends for the 90-yr duration were selected from a downscaled set of high-resolution (one-eighth degree) daily climate and hydrological simulations covering the entire Great Plains region, driven by the latest IPCC AR4 climate model outputs. These projections were used as input to the Ogallala Ag Tool software developed by the USDA-ARS to predict daily and seasonal values of those variables, which directly affect irrigation, at different locations in the study area. Results from the Ogallala Ag Tool were then used to drive future projected crop production functions for cotton, corn, wheat, and sorghum using the DSSAT crop model. These production functions were then included in an integrated economic-hydrologic modeling approach that coupled an economic optimization model with a groundwater hydrological model. The groundwater model was based on the Texas Water Development Board's Southern Ogallala Groundwater Availability Model, which has been recalibrated by the research team for previous applications. The coupling of the two models allowed better recognition of spatial heterogeneity across the SHP, such that irrigation water availability was better represented through the spatial variations in pumping demands and saturated thickness. With this hydrologic information, the economic model provides a better demonstration of potential shifts in crop selections, irrigated acreage, and dryland acreage across the SHP as individual farmers try to maximize their incomes.

  1. Sensitivity of hydrological performance assessment analysis to variations in material properties, conceptual models, and ventilation models

    SciTech Connect

    Sobolik, S.R.; Ho, C.K.; Dunn, E. [Sandia National Labs., Albuquerque, NM (United States); Robey, T.H. [Spectra Research Inst., Albuquerque, NM (United States); Cruz, W.T. [Univ. del Turabo, Gurabo (Puerto Rico)

    1996-07-01

    The Yucca Mountain Site Characterization Project is studying Yucca Mountain in southwestern Nevada as a potential site for a high-level nuclear waste repository. Site characterization includes surface- based and underground testing. Analyses have been performed to support the design of an Exploratory Studies Facility (ESF) and the design of the tests performed as part of the characterization process, in order to ascertain that they have minimal impact on the natural ability of the site to isolate waste. The information in this report pertains to sensitivity studies evaluating previous hydrological performance assessment analyses to variation in the material properties, conceptual models, and ventilation models, and the implications of this sensitivity on previous recommendations supporting ESF design. This document contains information that has been used in preparing recommendations for Appendix I of the Exploratory Studies Facility Design Requirements document.

  2. Effect of a canopy interception reservoir on hydrological persistence in a general circulation model

    SciTech Connect

    Scott, R.; Entekhabi, D. [Massachusetts Institute of Technology, Cambridge, MA (United States)] [Massachusetts Institute of Technology, Cambridge, MA (United States); Koster, R.D. [NASA/Goddard Space Flight Center, Greenbelt, MD (United States)] [and others] [NASA/Goddard Space Flight Center, Greenbelt, MD (United States); and others

    1995-07-01

    Using decadal GCM simulations, the effects of a SVAT (Surface-Vegetation-Atmosphere-Transfer) and a {open_quotes}bucket{close_quotes} and surface parameterization on simulated hydrological persistence are contrasted. The bucket model promotes persistence, as measured by the one-month-lagged autocorrelations of precipitation and evaporation, relative to the SVAT model, particularly in the Tropics. An additional simulation shows that despite the many complexities incorporated into the SVAT model`s evaporation formulation, it is the canopy interception reservoir alone that explains most of the difference. Water that evaporates from this reservoir bypasses bare soil and stomatal resistances. The interception reservoir thus acts as a short circuit in the soil and vegetation resistance network that decreases hydrological persistence by reducing the residence time of surface moisture. 15 refs., 3 figs.

  3. Linking Time and Space Scales in Distributed Hydrological Modelling - a case study for the VIC model

    NASA Astrophysics Data System (ADS)

    Melsen, Lieke; Teuling, Adriaan; Torfs, Paul; Zappa, Massimiliano; Mizukami, Naoki; Clark, Martyn; Uijlenhoet, Remko

    2015-04-01

    One of the famous paradoxes of the Greek philosopher Zeno of Elea (~450 BC) is the one with the arrow: If one shoots an arrow, and cuts its motion into such small time steps that at every step the arrow is standing still, the arrow is motionless, because a concatenation of non-moving parts does not create motion. Nowadays, this reasoning can be refuted easily, because we know that motion is a change in space over time, which thus by definition depends on both time and space. If one disregards time by cutting it into infinite small steps, motion is also excluded. This example shows that time and space are linked and therefore hard to evaluate separately. As hydrologists we want to understand and predict the motion of water, which means we have to look both in space and in time. In hydrological models we can account for space by using spatially explicit models. With increasing computational power and increased data availability from e.g. satellites, it has become easier to apply models at a higher spatial resolution. Increasing the resolution of hydrological models is also labelled as one of the 'Grand Challenges' in hydrology by Wood et al. (2011) and Bierkens et al. (2014), who call for global modelling at hyperresolution (~1 km and smaller). A literature survey on 242 peer-viewed articles in which the Variable Infiltration Capacity (VIC) model was used, showed that the spatial resolution at which the model is applied has decreased over the past 17 years: From 0.5 to 2 degrees when the model was just developed, to 1/8 and even 1/32 degree nowadays. On the other hand the literature survey showed that the time step at which the model is calibrated and/or validated remained the same over the last 17 years; mainly daily or monthly. Klemeš (1983) stresses the fact that space and time scales are connected, and therefore downscaling the spatial scale would also imply downscaling of the temporal scale. Is it worth the effort of downscaling your model from 1 degree to 1/24 degree, if in the end you only look at monthly runoff? In this study an attempt is made to link time and space scales in the VIC model, to study the added value of a higher spatial resolution-model for different time steps. In order to do this, four different VIC models were constructed for the Thur basin in North-Eastern Switzerland (1700 km²), a tributary of the Rhine: one lumped model, and three spatially distributed models with a resolution of respectively 1x1 km, 5x5 km, and 10x10 km. All models are run at an hourly time step and aggregated and calibrated for different time steps (hourly, daily, monthly, yearly) using a novel Hierarchical Latin Hypercube Sampling Technique (Vo?echovský, 2014). For each time and space scale, several diagnostics like Nash-Sutcliffe efficiency, Kling-Gupta efficiency, all the quantiles of the discharge etc., are calculated in order to compare model performance over different time and space scales for extreme events like floods and droughts. Next to that, the effect of time and space scale on the parameter distribution can be studied. In the end we hope to find a link for optimal time and space scale combinations.

  4. Comparing the effects on distributed hydrologic models derived from different elevation data over three regions

    NASA Astrophysics Data System (ADS)

    Sorichetta, A.; Taramelli, A.; Gorokhovich, Y.

    2006-12-01

    Demands for hydrologic prediction tools that utilize information about spatial variations in precipitation as well as land surface characteristics drive the evolution of spatially distributed hydrologic models. Several studies have found that spatially distributed hydrological models are sensitive to digital elevation models (DEM) resolution and their vertical accuracy. DEMs are basic input data in hydrologic models. Spatially distributed features, such as number of stream reaches, Strahler order, total length of the stream network and watershed area depend on DEM. The most widely available data source for DEM is Shuttle Radar Topographic Mission (SRTM) with resolution of about 90 m (global data) and 30 m (USA). Presented study evaluates the effect of vertical accuracy of DEM derived from SRTM on the spatial structure of the number of stream reaches (Strahler order), of the total length of the stream network and of the watershed area. These components are part of the principal input dataset for hydrologic modeling. Their structure (i.e. number of features) and spatial attributes (length and area) have considerable effect on modelling process and final output. For example, in rational method, the change in area directly affects discharge. The analysis is done by using three different DEMs derived from SRTM, National Elevation Data (the standard 25m DEM interpolated from contour lines) and topographic maps as an input into modelling procedure. The three DEMs cover different regions: two in Italy and one in USA. The study first analyzed the relationship between mean slope and mean elevation for the elaborated watersheds and then compared values of the derivatives for each pair of DEMs. Where blue lines derived from topographic maps are available, the study compared the stream network computed automatically from the three DEMs with the blue lines. The synthetic drainage networks were also classified in terms of stream ordering. The final overall results will help to translate the error in elevation data set into the error in hydrologic model input and eventually in predictions of the output (i.e. discharge and time lag).

  5. Constraining basal hydrology with model inversions of basal friction using new InSAR surface velocities.

    NASA Astrophysics Data System (ADS)

    Larour, E. Y.; Rignot, E. J.; Seroussi, H. L.; Morlighem, M.

    2011-12-01

    Constraining ice flow models for continental ice sheets such as Antarctica or Greenland can be difficult, especially regarding the specification of basal friction at the ice/bed interface. Historically, two approches have been taken: 1) model the basal hydrology of the ice sheet, and relate the resulting basal water pressure to the basal drag coefficient and 2) invert for the basal drag coefficient using InSAR surface velocities, and infer the resulting basal hydrology. Here, we use both approaches within the Ice Sheet System Model (ISSM), the JPL/UCI developed ice flow model, for which we develop a new hydrological model based on Johnson et al 2002. We compare this model against a massive inversion of Antarctica's basal drag coefficient using new InSAR surface velocities from Rignot et al 2011. We discuss the potential for this model to improve constraints on basal friction evolution, and implications for projections of ice flow dynamics in a changing climate. This work was performed at the California Institute of Technology's Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration's Cryosphere Science Program.

  6. Model-based quantification of hydrological similarity at the hillslope scale

    NASA Astrophysics Data System (ADS)

    Wienhöfer, Jan; Loritz, Ralf; Ehret, Uwe

    2015-04-01

    In the context of hydrological predictions in changing environments, there is an ongoing debate about a suitably general framework to characterize hydrological similarity. Similarity is a gradual and scale-dependent measure that may refer to inherent characteristics such as landscape form, soil types, or wetness state, as well as to related system responses and state changes with respect to their magnitude and dynamics. While it is reasonably self-evident that the combination of comparable physiogeographic characteristics, system states, and hydro-climatological forcing lead to comparable hydrological responses, quantitative understanding of these relationships is scarce. This paper explores this matter by means of virtual experiments using the spatially explicit hydrological model CATFLOW. We simulate the rainfall response of a forested hillslope marked by fine-textured soils and vertically and laterally draining macropores. Rainfall forcing and hillslope characteristics were varied systematically within realistic ranges, starting from a model setup that has been successfully tested against hydrometric and tracer data. Dynamical clustering of different response parameters, i.e., grouping according to runoff volume, peak discharge etc., conditional on the input characteristics, then provides a basis for studying hydrological similarity in a quantitative manner. These results provide insights in the conditions under which hillslopes are behaving similarly, and thus improve the understanding of dynamic landscape functions that can be used to guide real-world modelling and monitoring efforts. The complexity of a catchment may be expressed by the number and temporal sequence of different representative hillslopes needed to simulate or observe a catchment's behaviour within a desired level of confidence.

  7. The Distributed Hydrologic Model Intercomparison Project Phase 2 (DMIP 2): Overview and Initial NWS Results

    NASA Astrophysics Data System (ADS)

    Smith, M. B.; Koren, V.; Reed, S. M.; Zhang, Z.; Moreda, F.; Cui, Z.; Lei, F.; Cong, S.; Seo, D.

    2006-05-01

    The National Weather Service of the U.S. National Oceanic and Atmospheric Administration (NOAA/NWS) recognizes the need for a continued series of science experiments to guide its research into advanced hydrologic models for river and water resources forecasting. This need is accentuated by NOAA/NWS' recent advance into a broader spectrum of water resources forecasting, to complement its more traditional river and flash flood forecasting mission. To this end, the NOAA/NWS welcomes input and contributions from the national and international hydrologic research community in order to better fulfill its mandate to provide valuable products and services. In February of 2006, the Hydrology Laboratory (HL) of the NOAA /NWS Office of Hydrologic Development launched the second phase of the Distributed Hydrologic Model Intercomparison Project (DMIP 2). DMIP 2 follows the success of DMIP 1, which was completed in 2002. DMIP 1 provided a venue for researchers to compare their models with others and with NWS operational models, given a common set of forcings and verification data. The project attracted participants from 12 institutions based in Denmark, China, Canada, New Zealand, and the U.S. The experiments in DMIP 1 focused on the comparison of lumped and distributed models in hydrologically-simple regions. Models were forced with data used for NWS operational river forecasting. DMIP 1 results were mixed: in some basins, distributed models performed better than the NWS lumped model; in other cases the opposite was true. The DMIP 1 results were formally presented in a special issue of the Journal of Hydrology (Vol. 298, 2004). The scope of DMIP 2 is broader than that in DMIP 1 and is designed around two themes: 1) continued investigation of science questions pertinent to the DMIP 1 test sites, and 2) distributed and lumped model tests in hydrologically complex basins in the Sierra-Nevada mountains in the western U.S. DMIP 2 will benefit from data available from the Oklahoma Mesonet and an intense instrumentation effort in one of the Sierra- Nevada basins. Key science questions to be addressed in DMIP 2 include the following: What is the value of soil moisture observations in the validation of distributed models? How do distributed and lumped models perform given forecast estimates of precipitation? Can distributed models provide improved simulations in mountainous areas given current model forcings? Can appropriate observational network densities be defined in mountainous areas that will lead to improved simulations and forecasts? Can new observations of the rain/snow division provide improved streamflow simulations? Can existing remote-sensor observing platforms be better utilized in providing precipitation estimates in mountainous areas? In this presentation we will review the status of DMIP 2. In addition, we will briefly present updated results of HL's lumped and distributed models for the Oklahoma basins. In particular, we expect to show the effects of using an archive of more recent radar precipitation data for model calibration and verification than was used in DMIP 1. The DMIP 1 precipitation data suffered from known biases, especially in the early part of the calibration period.

  8. 18Year Land-Surface Hydrology Model Simulations for a Midlatitude Grassland Catchment in Valdai, Russia

    Microsoft Academic Search

    C. Adam Schlosser; Alan Robock; Konstantin Ya. Vinnikov; Nina A. Speranskaya; Yongkang Xue

    1997-01-01

    Off-line simulations of improved bucket hydrology and Simplified Simple Biosphere (SSiB) models are performed for a grassland vegetation catchment region, located at the Valdai water-balance research station in Russia, forced by observed meteorological and simulated actinometric data for 1966-83. Evaluation of the model simulations is performed using observations of total soil moisture in the top 1 m, runoff, evaporation, snow

  9. Effects of temporal and spatial resolution of calibration data on integrated hydrologic water quality model identification

    NASA Astrophysics Data System (ADS)

    Jiang, Sanyuan; Jomaa, Seifeddine; Büttner, Olaf; Rode, Michael

    2014-05-01

    Hydrological water quality modeling is increasingly used for investigating runoff and nutrient transport processes as well as watershed management but it is mostly unclear how data availablity determins model identification. In this study, the HYPE (HYdrological Predictions for the Environment) model, which is a process-based, semi-distributed hydrological water quality model, was applied in two different mesoscale catchments (Selke (463 km2) and Weida (99 km2)) located in central Germany to simulate discharge and inorganic nitrogen (IN) transport. PEST and DREAM(ZS) were combined with the HYPE model to conduct parameter calibration and uncertainty analysis. Split-sample test was used for model calibration (1994-1999) and validation (1999-2004). IN concentration and daily IN load were found to be highly correlated with discharge, indicating that IN leaching is mainly controlled by runoff. Both dynamics and balances of water and IN load were well captured with NSE greater than 0.83 during validation period. Multi-objective calibration (calibrating hydrological and water quality parameters simultaneously) was found to outperform step-wise calibration in terms of model robustness. Multi-site calibration was able to improve model performance at internal sites, decrease parameter posterior uncertainty and prediction uncertainty. Nitrogen-process parameters calibrated using continuous daily averages of nitrate-N concentration observations produced better and more robust simulations of IN concentration and load, lower posterior parameter uncertainty and IN concentration prediction uncertainty compared to the calibration against uncontinuous biweekly nitrate-N concentration measurements. Both PEST and DREAM(ZS) are efficient in parameter calibration. However, DREAM(ZS) is more sound in terms of parameter identification and uncertainty analysis than PEST because of its capability to evolve parameter posterior distributions and estimate prediction uncertainty based on global search and Bayesian inference schemes.

  10. Conditioning of a mesoscale hydrologic model with proxy soil moisture fields

    Microsoft Academic Search

    L. E. Samaniego-Eguiguren; A. Bardossy; R. Kumar

    2009-01-01

    Multiscale monitoring and data assimilation techniques are fundamental to improve the predictability of mesoscale distributed hydrologic models. In-situ measurements along with remote sensed information can be used to condition the parametrization of distributed models aiming at reducing their prediction uncertainty of both energy and mass balances. One of the key state variables responsible for the feedback mechanisms in the land-surface-atmosphere

  11. Analysis of the atmospheric water vapor transport and hydrologic cycle simulated in a global circulation model

    Microsoft Academic Search

    J. T. Chang

    1982-01-01

    An atmospheric moisture balance is diagnostically analyzed from the January and July data of the atmospheric general circulation model, which was integrated for thirty-nine months of simulation with seasonally-varying sea-surface temperature and solar insolation. The model hydrologic processes analyzed for the balance include the surface evaporation, the precipitation by large-scale and cumulus condensation, the vertical transport by large-scale and cumulus

  12. Hydrologic and Atrazine Simulation of the Cedar Creek Watershed Using the SWAT Model

    Microsoft Academic Search

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

    2007-01-01

    One of the major factors contributing to surface water contamina- tion in agricultural areas is the use of pesticides. The Soil and Water Assessment Tool (SWAT) is a hydrologic model capable of simulat- ing the fate and transport of pesticides in an agricultural watershed. The SWAT model was used in this study to estimate stream flow and atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) losses

  13. Assessment of Distributed Hydrologic Routing Parameter Estimates Used in the National Weather Service Research Modeling System

    Microsoft Academic Search

    S. M. Reed; V. Koren; M. Smith; Z. Zhang

    2002-01-01

    Areas upstream of the Illinois River at Tahlequah, OK, have been selected for study as part of the Distributed Model Intercomparison Project (DMIP) proposed by the National Weather Service Hydrology Laboratory (NWS-HL). This area is of interest for distributed modeling studies because there is a relatively long record of NEXRAD-based multi-sensor precipitation estimates, and because there are several nested streamflow

  14. A combined hydrologic simulation and landscape design model to prioritize sites for wetlands restoration

    Microsoft Academic Search

    Stephen C. Newbold

    2005-01-01

    Most landscape design models have been applied to the problem of maximizing species richness in a network of nature reserves.\\u000a This paper describes a combined hydrologic simulation and landscape design model designed to prioritize sites for wetlands\\u000a restoration, where the objective is to maximize the amount of nutrients in non-point-source runoff attenuated in the restored\\u000a wetlands. Targeted site selection in

  15. Ancient numerical daemons of conceptual hydrological modeling: 2. Impact of time stepping schemes on model analysis and prediction

    Microsoft Academic Search

    Dmitri Kavetski; Martyn P. Clark

    2010-01-01

    Despite the widespread use of conceptual hydrological models in environmental research and operations, they remain frequently implemented using numerically unreliable methods. This paper considers the impact of the time stepping scheme on model analysis (sensitivity analysis, parameter optimization, and Markov chain Monte Carlo-based uncertainty estimation) and prediction. It builds on the companion paper (Clark and Kavetski, 2010), which focused on

  16. Toll-like receptor (TLR)-mediated innate immune responses in the control of hepatitis B virus (HBV) infection.

    PubMed

    Zhang, Ejuan; Lu, Mengji

    2015-02-01

    The role of adaptive immune responses in the control of hepatitis B virus (HBV) infection is well accepted. The contribution of innate immune responses to the viral control is recognized but yet not fully understood. Toll-like receptors (TLRs) sense pathogen-associated molecule patterns and activate antiviral mechanisms including the intracellular antiviral pathways and the production of antiviral effectors like interferons (IFNs) and pro-inflammatory cytokines. Activation of the TLR3 pathway and the production of IFN-? represent one of the major mechanisms leading to the suppression of HBV replication in the liver, as shown in different in vitro and in vivo models. TLR4 signaling and TLR2 signaling result in the activation of intracellular pathways including MAPK and PI-3 K/Akt in hepatocytes and reduce HBV replication in an IFN-independent manner. HBV is able to counteract the actions of TLR3 and TLR2/4 through downregulation of TLR expression and attenuation of the cellular signaling pathways. Thus, TLR ligands are promising candidates as immunomodulators and therapeutics for the treatment of chronic HBV infection. Specific antiviral treatment against HBV could recover the TLR functions in chronic HBV infection and increase the effectiveness of therapeutic approaches based on TLR activation. PMID:25550115

  17. Spinoculation Enhances HBV Infection in NTCP-Reconstituted Hepatocytes

    PubMed Central

    Yan, Ran; Zhang, Yongmei; Cai, Dawei; Liu, Yuanjie; Cuconati, Andrea; Guo, Haitao

    2015-01-01

    Hepatitis B virus (HBV) infection and its sequelae remain a major public health burden, but both HBV basic research and the development of antiviral therapeutics have been hindered by the lack of an efficient in vitro infection system. Recently, sodium taurocholate cotransporting polypeptide (NTCP) has been identified as the HBV receptor. We herein report that we established a NTCP-complemented HepG2 cell line (HepG2-NTCP12) that supports HBV infection, albeit at a low infectivity level following the reported infection procedures. In our attempts to optimize the infection conditions, we found that the centrifugation of HepG2-NTCP12 cells during HBV inoculation (termed “spinoculation”) significantly enhanced the virus infectivity. Moreover, the infection level gradually increased with accelerated speed of spinoculation up to 1,000g tested. However, the enhancement of HBV infection was not significantly dependent upon the duration of centrifugation. Furthermore, covalently closed circular (ccc) DNA was detected in infected cells under optimized infection condition by conventional Southern blot, suggesting a successful establishment of HBV infection after spinoculation. Finally, the parental HepG2 cells remained uninfected under HBV spinoculation, and HBV entry inhibitors targeting NTCP blocked HBV infection when cells were spinoculated, suggesting the authentic virus entry mechanism is unaltered under centrifugal inoculation. Our data suggest that spinoculation could serve as a standard protocol for enhancing the efficiency of HBV infection in vitro. PMID:26070202

  18. Assimilating data from remote sensing into a high-resolution global hydrological model

    NASA Astrophysics Data System (ADS)

    Lu, Yang; Sutanudjaja, Edwin; Drost, Niels; Hut, Rolf; Steele-Dunne, Susan; van de Giesen, Nick; de Jong, Kor; van Beek, Ludovicus; Bierkens, Marc

    2014-05-01

    This study is focused on the challenges of assimilating current and planned remote sensing data into the modified PCR-GLOB-WB model to yield optimal results. The development of a high-resolution (1 km or finer) global hydrological model has been put forward as 'Grand Challenge' for the hydrological community. Extensive assimilation of remote sensing data is a promising route to constrain and ensure the accuracy of such a hydrological model, but it poses a great challenge in many aspects. Over the last 30 years, advances in remote sensing techniques have triggered the exponential growth of hydrologically useful data from remote sensing. Aside from the ICT challenge of streaming and handing the sheer volume of data, and selecting an appropriate assimilation algorithm, the fundamental questions of which datasets contain the most useful information and how to use them must be addressed. The first task is to divide the candidate datasets into those that will be assimilated and those that will be used to parameterize or force the model. As the time step is reduced from daily to ~hourly, remote sensing data may play a crucial role in providing a more dynamic description of the land surface, or in downscaling the forcing data. Here, we will present a outline of the key processes in the PCR-GLOB-WB and a summary of which states and fluxes will benefit most from assimilation, and which model parameters can be modified to incorporate real-time information from remote sensing. Finally, we need to consider the gap in spatial scales. The PCR-GLOB-WB model is now running at 10 km resolution and will be modified to run at 1 km scale, while the spatial resolution of many remote sensing products is considerably coarser. We will present an overview of the downscaling approaches under consideration for key state variables. The eWaterCycle project is a collaboration between Delft University of Technology, Utrecht University and the Netherlands eScience Center. The final aim is to establish a high-resolution global hydrological model at near-realtime to better represent the effects of spatial heterogeneity in topography, vegetation and soil moisture on hydrological processes around the globe. Together we will explore existing and novel methodologies in data assimilation to yield better results as well as ICT technologies to address the computational requirements.

  19. Modelling hydrological processes and analysing water-related ecosystem services of Western Siberian lowland basins

    NASA Astrophysics Data System (ADS)

    Schmalz, Britta; Kiesel, Jens; Kruse, Marion; Pfannerstill, Matthias; Sheludkov, Artyom; Khoroshavin, Vitaliy; Veshkurseva, Tatyana; Müller, Felix; Fohrer, Nicola

    2015-04-01

    For discussing and planning sustainable land management of river basins, stakeholders need suitable information on spatio-temporal patterns of hydrological components and ecosystem services. The ecosystem services concept, i.e., services provided by ecosystems that contribute to human welfare benefits, contributes comprehensive information for sustainable river management. This study shows an approach to use ecohydrological modelling results for quantifying and assessing water-related ecosystem services in three lowland river basins in Western Siberia, a region which is of global significance in terms of carbon sequestration, agricultural production and biodiversity preservation. Using the ecohydrological model SWAT, the three basins Pyschma (16762 km²), Vagai (3348 km²) and Loktinka (373 km²) were modelled following a gradient from the landscape units taiga, pre-taiga to forest steppe. For a correct representation of the Siberian lowland hydrology, the consideration of snow melt and retention of surface runoff as well as the implementation of a second groundwater aquifer was of great importance. Good to satisfying model performances were obtained for the extreme hydrological conditions. The simulated SWAT output variables of different hydrological processes were used as indicators for the two regulating services water flow and erosion regulation. The model results were translated into a relative ecosystem service valuation scale. The resulting ecosystem service maps show different spatial and seasonal patterns. Although the high resolution modelling results are averaged out within the aggregated relative valuation scale, seasonal differences can be depicted: during snowmelt, low relevant regulation can be determined, especially for water flow regulation, but a very high relevant regulation was calculated for the vegetation period during summer and for the winter period. The SWAT model serves as a suitable quantification method for the assessment of water-related ecosystem services on different spatial scales and ecoregions of the Western Siberian lowlands.

  20. Impacts of Polarimetric CASA Radar Observations on a Distributed Hydrologic Model

    NASA Astrophysics Data System (ADS)

    Chandrasekar, Venkatachalam; Chen, Haonan; Seo, Dong-Jun

    2013-04-01

    Radar can monitor the atmospheric conditions of a wide area very quickly and provide advanced observations and warnings for the precipitation systems at high spatial resolution. Over the past two decades, significant progress has been made in dual-polarization radar quantitative precipitation estimations (QPE). The polarimetric radar observations can provide more information on the drop size distribution and hydrometeor classifications over traditional Z-R methods. Among different rainfall algorithms, the Kdp-based QPE was proved to be immune to the partial beam blockage and hail contamination, and it is also less prone to the calibration errors. The networked Kdp-based QPE system developed by the U.S. National Science Foundation Engineering Research Center (NSF-ERC) for Collaborative Adaptive Sensing of the Atmosphere (CASA) has shown a great improvement compared with state-of-the-art. The high spatial and temporal resolution rainfall products from CASA QPE system can serve as a reliable data input for distributed hydrological models. The Research Distributed Hydrologic Model (RDHM) developed by the U.S. National Weather Service (NWS) Office of Hydrologic Development (OHD) is a promising tool for generating streamflow and other hydrological information such as soil moisture, etc. It can incorporate the heat transfer (HT) dynamics with the Sacramento soil moisture accounting model (SAC) to simulate rainfall-runoff and channel routing models for routing streamflow. In this research, the SAC-HT model was forced using hourly rainfall estimates produced by the CASA X-band dual-polarization radar network, for the purpose of predicting hydrological response and dealing with the flash flood issues. This paper will present a brief overview of the CASA QPE system and its various products. Then, the impacts of CASA QPE on SAC-HT model are mainly focused on, by using the networked polarimetric radar observations collected in IP-1 test bed in Southwestern Oklahoma. The "first" observation in CASA's urban demonstration network being deployed in the populous Dallas-Fort Worth (DFW) metroplex is also expected for the hydrological analysis.

  1. Some Modeling Tools Available for Adaptive Management of South Florida Hydrology

    NASA Astrophysics Data System (ADS)

    Lal, W. A.; Van Zee, R. J.

    2002-05-01

    The hydrology of South Florida is a result of (1) the hydrology of the natural system; (2) the hydrology of the man made design components such as structures and levees designed to alter the natural hydrology; (3) influence of the operations imposed on the system using the design components. Successful restoration of the South Florida ecosystem depend not only on the design of the structural components, but also on its careful operation. The current discussion is focused on a number of optimal control methods that have recently become available to optimize restoration goals in the context of modeling. Optimal operation of the system can lessen stresses on some hydrological and ecological components. Careless operation can on the other hand lead to disastrous effects. Systems engineering and control theory have been used in the past to understand and operate simple systems such as the cruise control and the thermostat. Somewhat complex ones have been used to auto-pilot planes. The simplest control methods such as proportional and integral (PI) control are already used in the South Florida Water Management Model (SFWMM) for flood control and rain driven operations. The popular proportional-integral-differential (PID) control is widely used in industry for operational control of complex engineering systems. Some uses of PID control are investigated in the study. Other methods that an be used for operational control include Baysean methods, Kalman filtering and Neural network methods. A cursory evaluation of these methods is made in the discussion, along with the traditional methods used to operate complex engineering systems.

  2. Development of Turbulent Diffusion Transfer Model to Estimate Hydrologic Budget of Upper Klamath Lake Oregon, USA

    NASA Astrophysics Data System (ADS)

    Sahoo, G. B.; Schladow, G.

    2013-12-01

    Detailed and accurate hydrologic budgets of lake or reservoirs are essential for sustainable water supply and ecosystem managements due to increasing water demand and uncertainties related to climate change. Ensuring sustainable water allocation to stakeholders requires accurate heat and hydrologic budgets. A number of micrometeorological methods have been developed to approximate heat budget components, such as evaporative and sensible heat loss, that are not directly measurable. Although micrometeorological methods estimate the sensible and evaporative loss well for stationary (i.e. ideal) condition, these methods can rarely be approximated for non-idealized condition. We developed a turbulent diffusion transfer model and coupled to the dynamic lake model (DLM-WQ), developed at UC Davis, with the goal of correctly estimating the hydrologic budget of Upper Klamath Lake Oregon, USA. The measured and DLM-WQ estimated lake water temperatures and water elevation are in excellent agreement with correlation coefficient equals 0.95 and 0.99, respectively. Consistent with previous studies, the sensible and latent heat exchange coefficients were found to be site specific. Estimated lake mixing shows that the lake became strongly stratified during summer (between late April and the end of August). For the hypereutrophic shallow Upper Klamath Lake, longer stratification results in low dissolved oxygen (DO) concentration at the sediment surface causing DO sensitive habitat destruction and ecological problems. The updated DLM-WQ can provide quantitative estimates of hydrologic components and predict the effects of natural- or human-induced changes in one component of the hydrologic cycle on the lake supplies and associated consequences.

  3. Impact of Model Uncertainty Description on Assimilating Hydraulic Head into the MIKE-SHE Distributed Hydrological Model

    NASA Astrophysics Data System (ADS)

    Zhang, D.; Madsen, H.; Ridler, M. E.; Rasmussen, J.; Refsgaard, J.; Jensen, K.

    2013-12-01

    Catchment-scale hydrological models are used as prediction tools to solve major challenges in water resources management. The reliability of hydrological model predictions is inevitably affected by the amount of information available to set up and calibrate the model. Data assimilation (DA) which combines complementary information from measurements and models has proven to be a powerful and promising tool in numerous research studies to improve model predictions. Especially, the ensemble Kalman filter (EnKF) which is a popular sequential data assimilation technique, has been extensively studied in the earth sciences for assimilating in-situ measurements and remote sensing data. However, one of the major challenges in data assimilation to optimally combine model and measurements is the description of model uncertainty. Only few studies have been reported for defining appropriate model uncertainty in hydrological DA. Modeling uncertainties can be conceptually different in different applications. Traditionally, model uncertainty is represented by parameter uncertainty with corresponding parameter statistics determined by inverse modeling. In most hydrological DA applications, however, model uncertainty is defined by experience using simple statistical descriptions of different uncertainty sources. In this work, both the uncertainty derived from inverse modeling and from empirical knowledge are used and analyzed. A combination of parameter-based, forcing-based and state-based model error is implemented in the EnKF framework for assimilating groundwater hydraulic heads into a catchment-scale model of the Karup Catchment in Denmark using the distributed and integrated hydrological model MIKE SHE. A series of synthetic identical twin experiments are carried out to analyze the impact of different model error assumptions on the feasibility and efficiency of the assimilation. The optimality of the EnKF underlying twin test provides possibilities to diagnose model error assumptions from a statistical sense. Beside the model noise, other factors like observation error, observation locations, and ensemble size can also be sensitive to the performance of the EnKF. Therefore, various aspects are considered in order to find and understand the ';optimal' settings for hydrological DA. Results suggest that inappropriate definition of model error can greatly degrade the assimilation performance. An appropriate combination of different model error sources is advised from this work.

  4. A Shuffled Complex Evolution Metropolis algorithm for optimization and uncertainty assessment of hydrological model parameters

    NASA Astrophysics Data System (ADS)

    Vrugt, J. A.; Gupta, H. V.; Bouten, W.; Sorooshian, S.

    2002-12-01

    Markov Chain Monte Carlo (MCMC) methods have become increasingly popular for estimating the posterior probability distribution of parameters in hydrologic models. However, MCMC methods require the a priori definition of a proposal or sampling distribution, which determines the explorative capabilities and efficiency of the sampler and therefore the statistical properties of the Markov Chain and its rate of convergence. In this presentation, we present an MCMC sampler entitled the Shuffled Complex Evolution Metropolis algorithm (SCEM-UA), which is well suited to infer the posterior distribution of hydrologic model parameters. The SCEM-UA algorithm is a modified version of the original SCE-UA global optimization algorithm developed by Duan et al. [1992]. Two case studies demonstrate that the adaptive capability of the SCEM algorithm significantly reduces the number of model simulations needed to infer the posterior distribution of the parameters when compared with the traditional Metropolis-Hastings samplers.

  5. Event-Based Hydrologic Model Calibration using NEXRAD Data in a Southern New Jersey Watershed

    NASA Astrophysics Data System (ADS)

    Seigel, C.; Daraio, J. A.

    2014-12-01

    Proper calibration of hydrologic models requires both reliable observed stream flow and precipitation data. Southern New Jersey has a notable lack of observed precipitation data, in particular, at the event scale; therefore model calibration represents a significant challenge. From a design standpoint this has not been a major concern as hydrologic models have been driven using design storms and are not calibrated. However, the need for research and impact analyses in the face of climate change (changes in extreme precipitation and sea-level rise in particular) and expected population growth in the region requires calibrated models, and reliable observed precipitation data are necessary for model calibration. Several HEC-HMS watershed models were developed and calibrated using NEXRAD data for the upper Maurice River watershed in southern New Jersey, which contains the two growing urban areas of Vineland and Glassboro, to meet three objectives: (1) to validate that NEXRAD data can be effectively utilized in this region, (2) to better understand the roles that spatial variability and scaling play in the use of NEXRAD data within a hydrologic model, and (3) to determine the possible effects of urbanization on stream flow within this watershed. Gridded NEXRAD data were converted to virtual rain gages using the Watershed Modeling System and used as input for HEC-HMS models. Preliminary results indicate that models forced by a spatially coarse distribution (one rain gage for the watershed) of precipitation perform better than models driven by higher resolution precipitation data (14 rain gages for the watershed) for large or extreme events (e.g. hurricanes), and higher resolution precipitation driven models performed better than lower resolution models for smaller events indicating that models should be calibrated from events of the same scale for valid model application.

  6. Using large hydrological datasets to create a robust, physically based, spatially distributed model for Great Britain

    NASA Astrophysics Data System (ADS)

    Lewis, Elizabeth; Kilsby, Chris; Fowler, Hayley

    2014-05-01

    The impact of climate change on hydrological systems requires further quantification in order to inform water management. This study intends to conduct such analysis using hydrological models. Such models are of varying forms, of which conceptual, lumped parameter models and physically-based models are two important types. The majority of hydrological studies use conceptual models calibrated against measured river flow time series in order to represent catchment behaviour. This method often shows impressive results for specific problems in gauged catchments. However, the results may not be robust under non-stationary conditions such as climate change, as physical processes and relationships amenable to change are not accounted for explicitly. Moreover, conceptual models are less readily applicable to ungauged catchments, in which hydrological predictions are also required. As such, the physically based, spatially distributed model SHETRAN is used in this study to develop a robust and reliable framework for modelling historic and future behaviour of gauged and ungauged catchments across the whole of Great Britain. In order to achieve this, a large array of data completely covering Great Britain for the period 1960-2006 has been collated and efficiently stored ready for model input. The data processed include a DEM, rainfall, PE and maps of geology, soil and land cover. A desire to make the modelling system easy for others to work with led to the development of a user-friendly graphical interface. This allows non-experts to set up and run a catchment model in a few seconds, a process that can normally take weeks or months. The quality and reliability of the extensive dataset for modelling hydrological processes has also been evaluated. One aspect of this has been an assessment of error and uncertainty in rainfall input data, as well as the effects of temporal resolution in precipitation inputs on model calibration. SHETRAN has been updated to accept gridded rainfall inputs, and UKCP09 gridded daily rainfall data has been disaggregated using hourly records to analyse the implications of using realistic sub-daily variability. Furthermore, the development of a comprehensive dataset and computationally efficient means of setting up and running catchment models has allowed for examination of how a robust parameter scheme may be derived. This analysis has been based on collective parameterisation of multiple catchments in contrasting hydrological settings and subject to varied processes. 350 gauged catchments all over the UK have been simulated, and a robust set of parameters is being sought by examining the full range of hydrological processes and calibrating to a highly diverse flow data series. The modelling system will be used to generate flow time series based on historical input data and also downscaled Regional Climate Model (RCM) forecasts using the UKCP09 Weather Generator. This will allow for analysis of flow frequency and associated future changes, which cannot be determined from the instrumental record or from lumped parameter model outputs calibrated only to historical catchment behaviour. This work will be based on the existing and functional modelling system described following some further improvements to calibration, particularly regarding simulation of groundwater-dominated catchments.

  7. HIBAL: A hydrologic-isotopic-balance model for application to paleolake systems

    USGS Publications Warehouse

    Benson, L.; Paillet, F.

    2002-01-01

    A simple hydrologic-isotopic-balance (HIBAL) model for application to paleolake ??18O records is presented. Inputs to the model include discharge, on-lake precipitation, evaporation, and the ??18O values of these fluid fluxes. Monthly values of climatic parameters that govern the fractionation of 18O and 16O during evaporation have been extracted from historical data sets and held constant in the model. The ability of the model to simulate changes in the hydrologic balance and the ??18O evolution of the mixed layer has been demonstrated using measured data from Pyramid Lake, Nevada. Simulations of the response in ??18O to step- and periodic-function changes in fluid inputs indicate that the hydrologic balance and ??18O values lag climate change. Input of reconstructed river discharges and their ??18O values to Pyramid and Walker lakes indicates that minima and maxima in simulated ??18O records correspond to minima and maxima in the reconstructed volume records and that the overall shape of the volume and ??18O records is similar. The model was also used in a simulation of abrupt oscillations in the ??18O values of paleo-Owens Lake, California.

  8. Sensitivity analysis and calibration of a coupled hydrological/slope stability model (TRIGRS)

    NASA Astrophysics Data System (ADS)

    Zieher, Thomas; Rutzinger, Martin; Perzl, Frank; Meißl, Gertraud

    2014-05-01

    Shallow landslides potentially endanger human living in mountain regions worldwide. In order to prevent impacts of such gravitational mass movements it is necessary to fully understand the proc