Science.gov

Sample records for hydrological model hbv

  1. Runoff simulation in the Ferghana Valley (Central Asia) using conceptual hydrological HBV-light model

    NASA Astrophysics Data System (ADS)

    Radchenko, Iuliia; Breuer, Lutz; Forkutsa, Irina; Frede, Hans-Georg

    2013-04-01

    Glaciers and permafrost on the ranges of the Tien Shan mountain system are primary sources of water in the Ferghana Valley. The water artery of the valley is the Syr Darya River that is formed by confluence of the Naryn and Kara Darya rivers, which originate from the mountain glaciers of the Ak-Shyrak and the Ferghana ranges accordingly. The Ferghana Valley is densely populated and main activity of population is agriculture that heavily depends on irrigation especially in such arid region. The runoff reduction is projected in future due to global temperature rise and glacier shrinkage as a consequence. Therefore, it is essential to study climate change impact on water resources in the area both for ecological and economic aspects. The evaluation of comparative contribution of small upper catchments (n=24) with precipitation predominance in discharge and the large Naryn and Karadarya River basins, which are fed by glacial melt water, to the Fergana Valley water balance under current and future climatic conditions is general aim of the study. Appropriate understanding of the hydrological cycle under current climatic conditions is significant for prognosis of water resource availability in the future. Thus, conceptual hydrological HBV-light model was used for analysing of the water balance of the small upper catchments that surround the Ferghana Valley. Three trial catchments (the Kugart River basin, 1010 km²; the Kurshab River basin, 2010 km2; the Akbura River basin, 2260 km²) with relatively good temporal quality data were chosen to setup the model. Due to limitation of daily temperature data the MODAWEC weather generator, which converts monthly temperature data into daily based on correlation with rainfall, was tested and applied for the HBV-light model.

  2. Moving horizon estimation for assimilating H-SAF remote sensing data into the HBV hydrological model

    NASA Astrophysics Data System (ADS)

    Montero, Rodolfo Alvarado; Schwanenberg, Dirk; Krahe, Peter; Lisniak, Dmytro; Sensoy, Aynur; Sorman, A. Arda; Akkol, Bulut

    2016-06-01

    Remote sensing information has been extensively developed over the past few years including spatially distributed data for hydrological applications at high resolution. The implementation of these products in operational flow forecasting systems is still an active field of research, wherein data assimilation plays a vital role on the improvement of initial conditions of streamflow forecasts. We present a novel implementation of a variational method based on Moving Horizon Estimation (MHE), in application to the conceptual rainfall-runoff model HBV, to simultaneously assimilate remotely sensed snow covered area (SCA), snow water equivalent (SWE), soil moisture (SM) and in situ measurements of streamflow data using large assimilation windows of up to one year. This innovative application of the MHE approach allows to simultaneously update precipitation, temperature, soil moisture as well as upper and lower zones water storages of the conceptual model, within the assimilation window, without an explicit formulation of error covariance matrixes and it enables a highly flexible formulation of distance metrics for the agreement of simulated and observed variables. The framework is tested in two data-dense sites in Germany and one data-sparse environment in Turkey. Results show a potential improvement of the lead time performance of streamflow forecasts by using perfect time series of state variables generated by the simulation of the conceptual rainfall-runoff model itself. The framework is also tested using new operational data products from the Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF) of EUMETSAT. This study is the first application of H-SAF products to hydrological forecasting systems and it verifies their added value. Results from assimilating H-SAF observations lead to a slight reduction of the streamflow forecast skill in all three cases compared to the assimilation of streamflow data only. On the other hand

  3. Solicited abstract: Global hydrological modeling and models

    NASA Astrophysics Data System (ADS)

    Xu, Chong-Yu

    2010-05-01

    The origins of rainfall-runoff modeling in the broad sense can be found in the middle of the 19th century arising in response to three types of engineering problems: (1) urban sewer design, (2) land reclamation drainage systems design, and (3) reservoir spillway design. Since then numerous empirical, conceptual and physically-based models are developed including event based models using unit hydrograph concept, Nash's linear reservoir models, HBV model, TOPMODEL, SHE model, etc. From the late 1980s, the evolution of global and continental-scale hydrology has placed new demands on hydrologic modellers. The macro-scale hydrological (global and regional scale) models were developed on the basis of the following motivations (Arenll, 1999). First, for a variety of operational and planning purposes, water resource managers responsible for large regions need to estimate the spatial variability of resources over large areas, at a spatial resolution finer than can be provided by observed data alone. Second, hydrologists and water managers are interested in the effects of land-use and climate variability and change over a large geographic domain. Third, there is an increasing need of using hydrologic models as a base to estimate point and non-point sources of pollution loading to streams. Fourth, hydrologists and atmospheric modellers have perceived weaknesses in the representation of hydrological processes in regional and global climate models, and developed global hydrological models to overcome the weaknesses of global climate models. Considerable progress in the development and application of global hydrological models has been achieved to date, however, large uncertainties still exist considering the model structure including large scale flow routing, parameterization, input data, etc. This presentation will focus on the global hydrological models, and the discussion includes (1) types of global hydrological models, (2) procedure of global hydrological model development

  4. Watershed Modeling of Nutrient Transport Covering the Country of Sweden - Scale Transfer in HBV-NP

    NASA Astrophysics Data System (ADS)

    Arheimer, B.; Andersson, L.

    2002-12-01

    Eutrophication of the Baltic Sea and its coastal zone is considered a serious environmental problem. The problems are mainly caused by excessive load of nitrogen (N) and phosphorus (P). To improve the situation new policies including watershed-based water management are implemented. However, this also demands watershed-based knowledge of nutrient transport proc-esses and appropriate tools for landscape planning. A watershed model (HBV-NP) that can be applied both on the local and the national scale has thus been developed to be used both for international reporting and scenario estimates for more efficient nutrient control strategies. The P part is presently developed within the Swedish Water Management Research Program (VASTRA), in which HBV-NP will be used for evaluation of best management practices, and for communication with local stake-holders. The model has recently been applied at the national scale for calculations of flow-normalized annual average of gross load, N retention and net transport, and source apportionment of the N load reaching the sea. In this application (called TRK) several submodels with different levels of process descriptions were linked together. Dynamic and detailed models were included for arable leaching (SOIL-N model), rainfall interpolation, atmospheric deposition (MATCH model), water balance (HBV), and nutrient transformation in groundwater, rivers and lakes (HBV-N). Based on landscape information in GIS, different leaching rates and emissions were assigned to the water discharge from similar landscape elements in 1000 subbasins covering Sweden. Scale transfer was mainly achieved through up-scaling procedures and by using the conceptual model approach for watershed hydrology, including variability parameters that are calibrated for regions. The modeled river flow and N concentrations were validated against time-series from several independent-monitoring stations. A similar national system is now under development for P, including

  5. An Educational Model for Hands-On Hydrology Education

    NASA Astrophysics Data System (ADS)

    AghaKouchak, A.; Nakhjiri, N.; Habib, E. H.

    2014-12-01

    This presentation provides an overview of a hands-on modeling tool developed for students in civil engineering and earth science disciplines to help them learn the fundamentals of hydrologic processes, model calibration, sensitivity analysis, uncertainty assessment, and practice conceptual thinking in solving engineering problems. The toolbox includes two simplified hydrologic models, namely HBV-EDU and HBV-Ensemble, designed as a complement to theoretical hydrology lectures. The models provide an interdisciplinary application-oriented learning environment that introduces the hydrologic phenomena through the use of a simplified conceptual hydrologic model. The toolbox can be used for in-class lab practices and homework assignments, and assessment of students' understanding of hydrological processes. Using this modeling toolbox, students can gain more insights into how hydrological processes (e.g., precipitation, snowmelt and snow accumulation, soil moisture, evapotranspiration and runoff generation) are interconnected. The educational toolbox includes a MATLAB Graphical User Interface (GUI) and an ensemble simulation scheme that can be used for teaching more advanced topics including uncertainty analysis, and ensemble simulation. Both models have been administered in a class for both in-class instruction and a final project, and students submitted their feedback about the toolbox. The results indicate that this educational software had a positive impact on students understanding and knowledge of hydrology.

  6. Uncertainty of the hydrological response to climate change conditions; 605 basins, 3 hydrological models, 5 climate models, 5 hydrological variables

    NASA Astrophysics Data System (ADS)

    Melsen, Lieke; Mizukami, Naoki; Newman, Andrew; Clark, Martyn; Teuling, Adriaan

    2016-04-01

    Many studies investigated the effect of a changing climate on the hydrological response of a catchment and uncertainty of the effect coming from hydrologic modelling (e.g., forcing, hydrologic model structures, and parameters). However, most past studies used only a single or a small number of catchments. To go beyond the case-study, and to assess the uncertainty involved in modelling the hydrological impact of climate change more comprehensively, we studied 605 basins over a wide range of climate regimes throughout the contiguous USA. We used three different widely-used hydrological models (VIC, HBV, SAC), which we forced with five distinct climate model outputs. The hydrological models have been run for a base period (1986-2008) for which observations were available, and for a future period (2070-2099). Instead of calibrating each hydrological model for each basin, the model has been run with a parameter sample (varying from 1600 to 1900 samples dependent on the number of free parameters in the model). Five hydrological states and fluxes were stored; discharge, evapotranspiration, soil moisture, SWE and snow melt, and 15 different metrics and signatures have been obtained for each model run. With the results, we conduct a sensitivity analysis over the change in signatures from the future period compared to the base period. In this way, we can identify the parameters that are responsible for certain projected changes, and identify the processes responsible for this change. By using three different models, in which VIC is most distinctive in including explicit vegetation parameters, we can compare different process representations and the effect on the projected hydrological change.

  7. Calibration and Uncertainty in Scenario Simulations with the HBV-N Nitrogen Model

    NASA Astrophysics Data System (ADS)

    Lindstrom, G.; Arheimer, B.

    2002-12-01

    The HBV model, a Swedish precipitation-runoff model has been used extensively in basins all over Sweden for 30 years. Recently, it has been complemented with routines for nitrogen transformation in groundwater, rivers and lakes. The aim is to develop a decision support tool for evaluation of nitrogen load on recipients due to different management practices and policies. The hydrological submodel has a large number of parameters, which are established by calibration, supported by experience from earlier model applications. The root zone leakage of nitrogen, used as input to the HBV model, is simulated by the SOIL-N model, a model for turnover of water, heat and nitrogen in the unsaturated zone. The nitrogen subroutines introduce additional parameters. It is clear that no unique optimum parameter set can be obtained from a single-site model calibation to runoff and nitrogen measurements. This equifinality results in a wide range of uncertainty in the scenario simulations, when studied by ordinary Monte Carlo simulation and acceptance of all parameter sets that produce a fitness criterion above a chosen limit. This is illustrated in a case study for the R”nne † basin in the agricultural region of southern Sweden. The objective of the uncertainty analysis is to explore the uncertainty in the scenario simulations, and to provide support for decision-makers to choose between measures according to expected results and the reliability of these results. However, an ordinary Monte Carlo simulation in which all parameters are simulated and combined randomly does not take advantage of the experience from earlier applications. Therefore, a method is proposed, in which parameter sets are judged not only according to the fitness to observations but also according to their agreement with earlier model applications and hydrological experience, by use of subjective likelihood weights. The range in the scenario simulations obtained from the combined approach is finally compared

  8. Calibration of hydrological model with programme PEST

    NASA Astrophysics Data System (ADS)

    Brilly, Mitja; Vidmar, Andrej; Kryžanowski, Andrej; Bezak, Nejc; Šraj, Mojca

    2016-04-01

    PEST is tool based on minimization of an objective function related to the root mean square error between the model output and the measurement. We use "singular value decomposition", section of the PEST control file, and Tikhonov regularization method for successfully estimation of model parameters. The PEST sometimes failed if inverse problems were ill-posed, but (SVD) ensures that PEST maintains numerical stability. The choice of the initial guess for the initial parameter values is an important issue in the PEST and need expert knowledge. The flexible nature of the PEST software and its ability to be applied to whole catchments at once give results of calibration performed extremely well across high number of sub catchments. Use of parallel computing version of PEST called BeoPEST was successfully useful to speed up calibration process. BeoPEST employs smart slaves and point-to-point communications to transfer data between the master and slaves computers. The HBV-light model is a simple multi-tank-type model for simulating precipitation-runoff. It is conceptual balance model of catchment hydrology which simulates discharge using rainfall, temperature and estimates of potential evaporation. Version of HBV-light-CLI allows the user to run HBV-light from the command line. Input and results files are in XML form. This allows to easily connecting it with other applications such as pre and post-processing utilities and PEST itself. The procedure was applied on hydrological model of Savinja catchment (1852 km2) and consists of twenty one sub-catchments. Data are temporary processed on hourly basis.

  9. RHydro - Hydrological models and tools to represent and analyze hydrological data in R

    NASA Astrophysics Data System (ADS)

    Reusser, D. E.; Buytaert, W.; Vitolo, C.

    2012-04-01

    In hydrology, basic equations and procedures keep being implemented from scratch by scientist, with the potential for errors and inefficiency. The use of libraries can overcome these problems. As an example, hydrological libraries could contain: 1. Major representations of hydrological processes such as infiltration, sub-surface runoff and routing algorithms. 2. Scaling functions, for instance to combine remote sensing precipitation fields with rain gauge data 3. Data consistency checks 4. Performance measures. Here we present a beginning for such a library implemented in the high level data programming language R. Currently, Top-model, the abc-Model, HBV, a multi-model ensamble called FUSE, data import routines for WaSiM-ETH as well basic visualization and evaluation tools are implemented. Care is taken to make functions and models compatible with other existing frameworks in hydrology, such as for example Hydromad.

  10. Dynamics of an HBV Model with Drug Resistance Under Intermittent Antiviral Therapy

    NASA Astrophysics Data System (ADS)

    Zhang, Ben-Gong; Tanaka, Gouhei; Aihara, Kazuyuki; Honda, Masao; Kaneko, Shuichi; Chen, Luonan

    2015-06-01

    This paper studies the dynamics of the hepatitis B virus (HBV) model and the therapy regimens of HBV disease. First, we propose a new mathematical model of HBV with drug resistance, and then analyze its qualitative and dynamical properties. Combining the clinical data and theoretical analysis, we demonstrate that our model is biologically plausible and also computationally viable. Second, we demonstrate that the intermittent antiviral therapy regimen is one of the possible strategies to treat this kind of complex disease. There are two main advantages of this regimen, i.e. it not only may delay the development of drug resistance, but also may reduce the duration of on-treatment time compared with the long-term continuous medication. Moreover, such an intermittent antiviral therapy can reduce the adverse side effects. Our theoretical model and computational results provide qualitative insight into the progression of HBV, and also a possible new therapy for HBV disease.

  11. Hydrological models are mediating models

    NASA Astrophysics Data System (ADS)

    Babel, L. V.; Karssenberg, D.

    2013-08-01

    Despite the increasing role of models in hydrological research and decision-making processes, only few accounts of the nature and function of models exist in hydrology. Earlier considerations have traditionally been conducted while making a clear distinction between physically-based and conceptual models. A new philosophical account, primarily based on the fields of physics and economics, transcends classes of models and scientific disciplines by considering models as "mediators" between theory and observations. The core of this approach lies in identifying models as (1) being only partially dependent on theory and observations, (2) integrating non-deductive elements in their construction, and (3) carrying the role of instruments of scientific enquiry about both theory and the world. The applicability of this approach to hydrology is evaluated in the present article. Three widely used hydrological models, each showing a different degree of apparent physicality, are confronted to the main characteristics of the "mediating models" concept. We argue that irrespective of their kind, hydrological models depend on both theory and observations, rather than merely on one of these two domains. Their construction is additionally involving a large number of miscellaneous, external ingredients, such as past experiences, model objectives, knowledge and preferences of the modeller, as well as hardware and software resources. We show that hydrological models convey the role of instruments in scientific practice by mediating between theory and the world. It results from these considerations that the traditional distinction between physically-based and conceptual models is necessarily too simplistic and refers at best to the stage at which theory and observations are steering model construction. The large variety of ingredients involved in model construction would deserve closer attention, for being rarely explicitly presented in peer-reviewed literature. We believe that devoting

  12. PATHS groundwater hydrologic model

    SciTech Connect

    Nelson, R.W.; Schur, J.A.

    1980-04-01

    A preliminary evaluation capability for two-dimensional groundwater pollution problems was developed as part of the Transport Modeling Task for the Waste Isolation Safety Assessment Program (WISAP). Our approach was to use the data limitations as a guide in setting the level of modeling detail. PATHS Groundwater Hydrologic Model is the first level (simplest) idealized hybrid analytical/numerical model for two-dimensional, saturated groundwater flow and single component transport; homogeneous geology. This document consists of the description of the PATHS groundwater hydrologic model. The preliminary evaluation capability prepared for WISAP, including the enhancements that were made because of the authors' experience using the earlier capability is described. Appendixes A through D supplement the report as follows: complete derivations of the background equations are provided in Appendix A. Appendix B is a comprehensive set of instructions for users of PATHS. It is written for users who have little or no experience with computers. Appendix C is for the programmer. It contains information on how input parameters are passed between programs in the system. It also contains program listings and test case listing. Appendix D is a definition of terms.

  13. 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.

  14. Estimation of instantaneous peak flow from daily data using the HBV model

    NASA Astrophysics Data System (ADS)

    Ding, Jie; Haberlandt, Uwe

    2015-04-01

    The length of the observed instantaneous peak flow (IPF) period has a great influence on the flood design whereas these high resolution flow data are not always available. Our previous research has shown that IPFs can be derived from the easier available observed long time series of mean daily flows (MDFs) using a multiple regression model. The primary aim here is to explore the possibility of deriving frequency distributions of IPFs using hydrological modelling with daily and hourly time steps in comparison. In the post-correction approach the rainfall-runoff model is operated on daily time steps , a flood frequency distribution is fitted to the simulated annual MDFs and the resulting daily quantiles are transferred into IPF quantiles using the multiple regression model. In the pre-processing approach, hourly rainfall is produced by disaggregation of daily data. Then the rainfall-runoff model is operated on hourly time steps resulting in a frequency distribution of IPFs. In addition, two calibrations strategies for the hydrological model using the hydrograph and using flow statistics, respectively, are applied for both approaches. Finally, the performances of estimating the IPFs from daily data using these two approaches are compared considering also the two different calibration strategies. The hydrological simulations are carried out with the HBV-IWW model and the case study is carried out for 18 catchments of the Aller-Leine-River basin in northern Germany. The results show that: (1) the multiple regression model is capable to predict IPFs with the simulated MDFs as well; (2) the estimation of extreme flow quantiles in summer is not as good as in winter; (3) both of the two approaches enable a reasonable estimation of IPFs; (4) if on hand the hydrological model is calibrated on the hydrograph the post-correction approach with daily simulations is superior and if on the other hand the model is calibrated on flow statistics the pre-processing with hourly

  15. Play with hydrologic models in R

    NASA Astrophysics Data System (ADS)

    Viglione, A.; Parajka, J.; Nester, T.; Blöschl, G.

    2012-04-01

    The aim of this poster is to show the advantages of building hydrologic models using the R environment for educational purposes. As an example we consider a conceptual rainfall-runoff model (HBV type) that was originally written in the fortran language and is used in many scientific studies and practical engineering applications in Austria. A simplified version of the model was built into a R package and compiled for different platforms and operating systems. The model runs on a daily time step and consists of a snow routine, a soil moisture routine and a flow routing routine. In this poster we present a set of examples that have been used in a graduate level course on engineering hydrology at the Vienna University of Technology. These include: - Multi-objective calibration of the model; - Manual vs. automatic calibration; - Visualisation of model outputs and efficiency; - Model application in ungauged catchments; - Operational forecast. The flexibility of R is ideal for education, since students can easily play with the extensive list of existing functionalities and define new functions and extensions.

  16. Modeling and Analyzing the Transmission Dynamics of HBV Epidemic in Xinjiang, China

    PubMed Central

    Zhang, Tailei; Wang, Kai; Zhang, Xueliang

    2015-01-01

    Hepatitis B is an infectious disease caused by the hepatitis B virus (HBV) which affects livers. In this paper, we formulate a hepatitis B model to study the transmission dynamics of hepatitis B in Xinjiang, China. The epidemic model involves an exponential birth rate and vertical transmission. For a better understanding of HBV transmission dynamics, we analyze the dynamic behavior of the model. The modified reproductive number σ is obtained. When σ < 1, the disease-free equilibrium is locally asymptotically stable, when σ > 1, the disease-free equilibrium is unstable and the disease is uniformly persistent. In the simulation, parameters are chosen to fit public data in Xinjiang. The simulation indicates that the cumulated HBV infection number in Xinjiang will attain about 600,000 cases unless there are stronger or more effective control measures by the end of 2017. Sensitive analysis results show that enhancing the vaccination rate for newborns in Xinjiang is very effective to stop the transmission of HBV. Hence, we recommend that all infants in Xinjiang receive the hepatitis B vaccine as soon as possible after birth. PMID:26422614

  17. 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

  18. 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 sophisticated. 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 prediction of runoff extremes. As expected given their complexity, HBV and PREVAH have more problems with over-fitting. All models show a tendency towards better performance 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).

  19. Sensitivity Analysis of a Conceptual HBV Raınfall-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

  20. 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.

  1. Snow hydrology of a headwater Arctic basin. 2. Conceptual analysis and computer modeling

    SciTech Connect

    Hinzman, L.D.; Kane, D.L. )

    1991-06-01

    Lack of hydrologic data in the Arctic, particularly during snowmelt, severely limits modeling strategy. Spring snowmelt in Imnavait watershed is a very brief event, usually lasting about 10 days. Peak flow normally occurs within the top 10 cm of the highly organic soil mat or on the surface. Snow damming of snowmelt runoff is an important mechanism which must be considered in the modeling process of small watersheds. These unique characteristics of Arctic hydrology will affect the methodology and performance of a hydrologic model. The HBV model was used in an investigation of the hydrologic regime of an Arctic watershed during the spring snowmelt period. From the analysis of five spring melt events the authors found that HBV can adequately predict soil moisture, evaporation, snow ablation and accumulation, and runoff. It models the volumes of snowmelt runoff well, but more data are needed to improve the determination of snowmelt initiation. Use of HBV as a predictive tool is dependent upon the quality of the meteorologic forecast data.

  2. HBV culture and infectious systems.

    PubMed

    Hayes, C Nelson; Chayama, Kazuaki

    2016-07-01

    While an effective vaccine against hepatitis B virus (HBV) has long been available, chronic HBV infection remains a severe global public health concern. Current treatment options have limited effectiveness, and long-term therapy is required to suppress HBV replication; however, complete elimination of the virus is rare. The lack of suitable animal models and infection systems has hindered efforts to unravel the HBV life cycle, particularly the early events in HBV entry, which appear to be highly species- and tissue-specific. Human primary hepatocytes remain the gold standard for HBV replication studies but are limited by availability and variability. While the HepaRG cell line is permissive for HBV replication, other hepatoma cell lines such as HepG2 do not support HBV replication. The recent discovery of sodium taurocholate transporting peptide (NTCP) as a primary receptor for HBV binding has led to the development of replication-competent cell lines such as HepG2-NTCP. Human hepatocytes grown in chimeric mice have provided another approach that allows primary human hepatocytes to be used while overcoming many of their limitations. Although the difficulty in developing HBV infection systems has hindered development of effective treatments, the variability and limited replication efficiency among cell lines point to additional liver-specific factors involved in HBV infection. It is hoped that HBV infection studies will lead to novel drug targets and therapeutic options for the treatment of chronic HBV infection.

  3. 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

  4. 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.

  5. The influence of HBV model calibration on flood predictions for future climate

    NASA Astrophysics Data System (ADS)

    Osuch, Marzena; Romanowicz, Renata

    2014-05-01

    The temporal variability of HBV rainfall-runoff model parameters was tested to address the influence of climate characteristics on the values of model optimal parameters. HBV is a conceptual model with a physically-based structure that takes into account soil moisture, snow-melt and dynamic runoff components. The model parameters were optimized by the DEGL method (Differential Evolution with Global and Local neighbours) for a set of catchments located in Poland. The methodology consisted of the calibration and cross-validation of the HBV models on a series of five-year periods within a moving window. The optimal parameter values show large temporal variability and dependence on climatic conditions described by the mean and standard deviation of precipitation, air temperature and PET. Derived regressions models between parameters and climatic indices were statistically significant at the 0.05 level. The set of model optimal values was applied to simulate future flows in a changed climate. We used the precipitation and temperature series from 6 RCM/GCM models for 2071-2100 following the A1B climate change scenario. The climatic variables were obtained from the KLIMADA project. The resulting flow series for the future climate scenario were used to derive flow indices, including the flood quantiles. Results indicate a large influence of climatic variability on flow indices. This work was partly supported by the project "Stochastic flood forecasting system (The River Vistula reach from Zawichost to Warsaw)" carried out by the Institute of Geophysics, Polish Academy of Sciences by order of the National Science Centre (contract No. 2011/01/B/ST10/06866). The rainfall and flow data were provided by the Institute of Meteorology and Water Management (IMGW), Poland.

  6. Exploring the effect of spatial disaggregation of conceptual hydrologic models for improved flow forecasting

    NASA Astrophysics Data System (ADS)

    Wi, S.; Brown, C. M.

    2013-12-01

    The availability of gridded climatic data, high resolution Digital Elevation Maps (DEM), soil, land-use and land-cover data has motivated researchers to exploit these data for more accurate distributed hydrologic modeling. However, with increased disaggregation there is the introduction of numerous parameters and conceptualized processes that are unobservable. In this study we explore the advantage of employing spatially distributed climatic and geographic information in the context of a disaggregated conceptual hydrologic modeling framework by developing distributed model versions for three hydrologic models: HYMOD (Hydrologic Model), HBV (Hydrologiska Byrans Vattenbalansavdelning), and SAC-SMA (Sacramento Soil Moisture Accounting). This study proposes a general framework for building a distributed conceptual hydrological model by coupling a rainfall-runoff model to a routing model which is based on the formularized sub-basin unit hydrograph and the linearized Saint-Venant equation. To deal with a very large number of model parameters resulting from the distributed system modeling approach, hydrological similarity and landscape classification derived from the geospatial database is used to reduce the complexity in the process of model parameter estimation. Tests for the Iowa River basin show that three distributed models outperform lumped model versions in terms of reproducing observed streamflow for both calibration and validation periods. Model calibration strategies informed by geospatial information yield flow predictions comparable to the fully distributed model simulations. Results from this study are encouraging and indicate that the proposed framework holds promise for making improved predictions of hydrologic system response.

  7. 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.

  8. Hydrological Modeling of Continental-Scale Basins

    NASA Astrophysics Data System (ADS)

    Wood, Eric F.; Lettenmaier, Dennis; Liang, Xu; Nijssen, Bart; Wetzel, Suzanne W.

    Hydrological models at continental scales are traditionally used for water resources planning. However, continental-scale hydrological models may be useful in assessing the impacts from future climate change on catchment hydrology and water resources or from human activity on hydrology and biogeochemical cycles at large scales. Development of regional-scale terrestrial hydrological models will further our understanding of the Earth's water cycle. Continental scales allow for better understanding of the geographic distribution of land-atmospheric moisture fluxes, improved water management at continental scales, better quantification of the impact of human activity and climate change on the water cycle, and improved simulation of weather and climate.

  9. 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.

  10. Application of hydrologic forecast model.

    PubMed

    Hua, Xu; Hengxin, Xue; Zhiguo, Chen

    2012-01-01

    In order to overcome the shortcoming of the solution may be trapped into the local minimization in the traditional TSK (Takagi-Sugeno-Kang) fuzzy inference training, this paper attempts to consider the TSK fuzzy system modeling approach based on the visual system principle and the Weber law. This approach not only utilizes the strong capability of identifying objects of human eyes, but also considers the distribution structure of the training data set in parameter regulation. In order to overcome the shortcoming of it adopting the gradient learning algorithm with slow convergence rate, a novel visual TSK fuzzy system model based on evolutional learning is proposed by introducing the particle swarm optimization algorithm. The main advantage of this method lies in its very good optimization, very strong noise immunity and very good interpretability. The new method is applied to long-term hydrological forecasting examples. The simulation results show that the method is feasible and effective, the new method not only inherits the advantages of traditional visual TSK fuzzy models but also has the better global convergence and accuracy than the traditional model.

  11. Simulated discharge trends indicate robustness of hydrological models in a changing climate

    NASA Astrophysics Data System (ADS)

    Addor, Nans; Nikolova, Silviya; Seibert, Jan

    2016-04-01

    Assessing the robustness of hydrological models under contrasted climatic conditions should be part any hydrological model evaluation. Robust models are particularly important for climate impact studies, as models performing well under current conditions are not necessarily capable of correctly simulating hydrological perturbations caused by climate change. A pressing issue is the usually assumed stationarity of parameter values over time. Modeling experiments using conceptual hydrological models revealed that assuming transposability of parameters values in changing climatic conditions can lead to significant biases in discharge simulations. This raises the question whether parameter values should to be modified over time to reflect changes in hydrological processes induced by climate change. Such a question denotes a focus on the contribution of internal processes (i.e., catchment processes) to discharge generation. Here we adopt a different perspective and explore the contribution of external forcing (i.e., changes in precipitation and temperature) to changes in discharge. We argue that in a robust hydrological model, discharge variability should be induced by changes in the boundary conditions, and not by changes in parameter values. In this study, we explore how well the conceptual hydrological model HBV captures transient changes in hydrological signatures over the period 1970-2009. Our analysis focuses on research catchments in Switzerland undisturbed by human activities. The precipitation and temperature forcing are extracted from recently released 2km gridded data sets. We use a genetic algorithm to calibrate HBV for the whole 40-year period and for the eight successive 5-year periods to assess eventual trends in parameter values. Model calibration is run multiple times to account for parameter uncertainty. We find that in alpine catchments showing a significant increase of winter discharge, this trend can be captured reasonably well with constant

  12. A new multiparameter integrated MELD model for prognosis of HBV-related acute-on-chronic liver failure.

    PubMed

    Luo, Yue; Xu, Yun; Li, Mingming; Xie, Ya; Gong, Guozhong

    2016-08-01

    Hepatitis B virus related acute-on-chronic liver failure (HBV-ACLF) is one of the most deadly diseases. Many models have been proposed to evaluate the prognosis of it. However, these models are still controversial. In this study, we aimed to incorporate some characters into model for end-stage liver disease (MELD) to establish a new reliable and feasible model for the prognosis of HBV-ACLF.A total of 530 HBV-ACLF patients who had received antiviral therapy were enrolled into a retrospective study and divided into the training cohort (300) and validation cohort (230). Logistic regression analysis was used to establish a model to predict the 3-month mortality from the patients in the training cohort, and then, the new model was evaluated in the validation cohort.Except for MELD score, 4 other independent factors, namely degree of hepatic encephalopathy (HE), alpha-fetoprotein (AFP), white blood cell (WBC) count, and age, were important for the new model called HBV-ACLF MELD (HAM) model: R = 0.174 × MELD + 1.106 × HE - (0.003 × AFP) + (0.237 × WBC) + (0.103 × Age) - 11.388. The areas under receiver-operating characteristic curve of HAM in the training and validation cohort were 0.894 and 0.868, respectively, which were significantly higher than those of other 7 models. With the best cut-off value of -1.191, HAM achieved higher sensitivity and negative predictive value.We developed a new model that has a great prognostic value of the 3-month mortality of patients with HBV-ACLF. PMID:27559979

  13. Hydrologic Modeling of Boreal Forest Ecosystems

    NASA Technical Reports Server (NTRS)

    Haddeland, I.; Lettenmaier, D. P.

    1995-01-01

    This study focused on the hydrologic response, including vegetation water use, of two test regions within the Boreal-Ecosystem-Atmosphere Study (BOREAS) region in the Canadian boreal forest, one north of Prince Albert, Saskatchewan, and the other near Thompson, Manitoba. Fluxes of moisture and heat were studied using a spatially distributed hydrology soil-vegetation-model (DHSVM).

  14. Hierarchical mixture of experts and diagnostic modeling approach to reduce hydrologic model structural uncertainty

    NASA Astrophysics Data System (ADS)

    Moges, Edom; Demissie, Yonas; Li, Hong-Yi

    2016-04-01

    In most water resources applications, any particular model structure might be inadequate to capture the dynamic multiscale interactions among different hydrological processes. Calibrating single models for dynamic catchments, where multiple dominant processes exist, can result in displacement of errors from structure to parameters, which in turn leads to over-correction and biased predictions. An alternative to a single model structure is to develop local expert structures that are effective in representing the dominant components of the hydrologic process and adaptively integrate them based on an indicator variable. In this study, the Hierarchical Mixture of Experts (HME) framework is applied to integrate expert model structures representing the different components of the hydrologic process. Various signature diagnostic analyses were used to identify the presence of multiple dominant processes, and the adequacy of a single model, as well as to develop the structures of the expert models. The approaches are applied for two distinct catchments, the Guadalupe River (Texas) and the French Broad River (North Carolina) from the Model Parameter Estimation Experiment (MOPEX), using different structures of the HBV model. The results show that the HME approach has a better performance over the single model for the Guadalupe catchment, where multiple dominant processes are witnessed through diagnostic measures. Whereas the diagnostics and aggregated performance measures prove that French Broad has a homogeneous catchment response, making the single model adequate to capture the response.

  15. Snow hydrology in a general circulation model

    NASA Technical Reports Server (NTRS)

    Marshall, Susan; Roads, John O.; Glatzmaier, Gary

    1994-01-01

    A snow hydrology has been implemented in an atmospheric general circulation model (GCM). The snow hydrology consists of parameterizations of snowfall and snow cover fraction, a prognostic calculation of snow temperature, and a model of the snow mass and hydrologic budgets. Previously, only snow albedo had been included by a specified snow line. A 3-year GCM simulation with this now more complete surface hydrology is compared to a previous GCM control run with the specified snow line, as well as with observations. In particular, the authors discuss comparisons of the atmospheric and surface hydrologic budgets and the surface energy budget for U.S. and Canadian areas. The new snow hydrology changes the annual cycle of the surface moisture and energy budgets in the model. There is a noticeable shift in the runoff maximum from winter in the control run to spring in the snow hydrology run. A substantial amount of GCM winter precipitation is now stored in the seasonal snowpack. Snow cover also acts as an important insulating layer between the atmosphere and the ground. Wintertime soil temperatures are much higher in the snow hydrology experiment than in the control experiment. Seasonal snow cover is important for dampening large fluctuations in GCM continental skin temperature during the Northern Hemisphere winter. Snow depths and snow extent show good agreement with observations over North America. The geographic distribution of maximum depths is not as well simulated by the model due, in part, to the coarse resolution of the model. The patterns of runoff are qualitatively and quantitatively similar to observed patterns of streamflow averaged over the continental United States. The seasonal cycles of precipitation and evaporation are also reasonably well simulated by the model, although their magnitudes are larger than is observed. This is due, in part, to a cold bias in this model, which results in a dry model atmosphere and enhances the hydrologic cycle everywhere.

  16. Comparison of global optimization approaches for robust calibration of hydrologic model parameters

    NASA Astrophysics Data System (ADS)

    Jung, I. W.

    2015-12-01

    Robustness of the calibrated parameters of hydrologic models is necessary to provide a reliable prediction of future performance of watershed behavior under varying climate conditions. This study investigated calibration performances according to the length of calibration period, objective functions, hydrologic model structures and optimization methods. To do this, the combination of three global optimization methods (i.e. SCE-UA, Micro-GA, and DREAM) and four hydrologic models (i.e. SAC-SMA, GR4J, HBV, and PRMS) was tested with different calibration periods and objective functions. Our results showed that three global optimization methods provided close calibration performances under different calibration periods, objective functions, and hydrologic models. However, using the agreement of index, normalized root mean square error, Nash-Sutcliffe efficiency as the objective function showed better performance than using correlation coefficient and percent bias. Calibration performances according to different calibration periods from one year to seven years were hard to generalize because four hydrologic models have different levels of complexity and different years have different information content of hydrological observation. Acknowledgements This research was supported by a grant (14AWMP-B082564-01) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

  17. Hydrological modeling as an evaluation tool of EURO-CORDEX RCMs and bias correction methods

    NASA Astrophysics Data System (ADS)

    Hakala, Kirsti; Seibert, Jan; Addor, Nans

    2016-04-01

    This research explores the impacts of climate change on catchment discharge and addresses the challenge of characterizing and communicating their uncertainties. It particularly focuses on the integrated evaluation of EURO-CORDEX regional climate model simulations, using hydrological modeling at the catchment scale. For the evaluation of the various RCMs combined with different bias correction operations there are two main approaches: 1) Separate evaluation of the statistical properties of each climate variable in terms of its statistical properties such as annual mean, seasonal variation, frequency of extreme events. This first approach is the standard way to evaluate RCM runs and bias correction methods. It also prevails by far in the literature. Here we introduce an alternative evaluation approach, which relies on hydrological modeling, 2) Combined evaluation of the different variables at the catchment scale; that is the evaluation is based on hydrological simulation results, which integrate the different variables (mainly temperature, precipitation and evaporation). Although more time demanding, this second approach has a critical advantage in that it allows a focus on the statistical properties of the climate variables which are most important for catchment-scale runoff. We rely on the semi-distributed hydrological model HBV and apply it to Swiss catchments representative of different hydrological regimes and expected responses to climate change. This research investigates both approaches, however the second approach will be discussed in greater depth as an elegant way to consider the multitude of factors relevant for hydrological modeling all at once.

  18. When are multiobjective calibration trade-offs in hydrologic models meaningful?

    NASA Astrophysics Data System (ADS)

    Kollat, J. B.; Reed, P. M.; Wagener, T.

    2012-03-01

    This paper applies a four-objective calibration strategy focusing on peak flows, low flows, water balance, and flashiness to 392 model parameter estimation experiment (MOPEX) watersheds across the United States. Our analysis explores the influence of model structure by analyzing how the multiobjective calibration trade-offs for two conceptual hydrologic models, the Hydrology Model (HYMOD) and the Hydrologiska Byråns Vattenbalansavdelning (HBV) model, compare for each of the 392 catchments. Our results demonstrate that for modern multiobjective calibration frameworks to identify any meaningful measure of model structural failure, users must be able to carefully control the precision by which they evaluate their trade-offs. Our study demonstrates that the concept of epsilon-dominance provides an effective means of attaining bounded and meaningful hydrologic model calibration trade-offs. When analyzed at an appropriate precision, we found that meaningful multiobjective trade-offs are far less frequent than prior literature has suggested. However, when trade-offs do exist at a meaningful precision, they have significant value for supporting hydrologic model selection, distinguishing core model deficiencies, and identifying hydroclimatic regions where hydrologic model prediction is highly challenging.

  19. From hydrological modelling to decision support

    NASA Astrophysics Data System (ADS)

    Haberlandt, U.

    2010-08-01

    Decision support for planning and management of water resources needs to consider many target criteria simultaneously like water availability, water quality, flood protection, agriculture, ecology, etc. Hydrologic models provide information about the water balance components and are fundamental for the simulation of ecological processes. Objective of this contribution is to discuss the suitability of classical hydrologic models on one hand and of complex eco-hydrologic models on the other hand to be used as part of decision support systems. The discussion is based on results from two model comparison studies. It becomes clear that none of the hydrologic models tested fulfils all requirements in an optimal sense. Regarding the simulation of water quality parameters like nitrogen leaching a high uncertainty needs to be considered. Recommended for decision support is a hybrid metamodel approach, which comprises a hydrologic model, empirical relationships for the less dynamic processes and makes use of simulation results from complex eco-hydrologic models through second-order modelling at a generalized level.

  20. HBV pathogenesis in animal models: recent advances on the role of platelets.

    PubMed

    Iannacone, Matteo; Sitia, Giovanni; Ruggeri, Zaverio M; Guidotti, Luca G

    2007-04-01

    Hepatitis B virus (HBV) causes acute and chronic necroinflammatory liver diseases and hepatocellular carcinoma (HCC). HBV replicates noncytopathically in the hepatocyte, and most of the liver injury associated with this infection reflects the immune response. While the innate immune response may not contribute significantly to the pathogenesis of liver disease or viral clearance, the adaptive immune response, particularly the cytotoxic T lymphocyte (CTL) response, contributes to both. Recent observations also reveal that antigen-nonspecific inflammatory cells enhance CTL-induced liver pathology and, more surprisingly, that platelets facilitate the intrahepatic accumulation of CTLs, suggesting that the host response to HBV infection is a highly complex but coordinated process. The notion that platelets contribute to liver disease and viral clearance by promoting the recruitment of virus-specific CTLs into the liver is a new concept in viral pathogenesis, which may prove useful to implement treatments of chronic HBV infection in man.

  1. Accelerating advances in continental domain hydrologic modeling

    USGS Publications Warehouse

    Archfield, Stacey A.; Clark, Martyn; Arheimer, Berit; Hay, Lauren E.; McMillan, Hilary; Kiang, Julie E.; Seibert, Jan; Hakala, Kirsti; Bock, Andrew R.; Wagener, Thorsten; Farmer, William H.; Andreassian, Vazken; Attinger, Sabine; Viglione, Alberto; Knight, Rodney; Markstrom, Steven; Over, Thomas M.

    2015-01-01

    In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written from a catchment hydrology community perspective, provides a review of progress in each community toward this achievement, identifies common challenges the communities face, and details immediate and specific areas in which these communities can mutually benefit one another from the convergence of their research perspectives. Those include: (1) creating new incentives and infrastructure to report and share model inputs, outputs, and parameters in data services and open access, machine-independent formats for model replication or reanalysis; (2) ensuring that hydrologic models have: sufficient complexity to represent the dominant physical processes and adequate representation of anthropogenic impacts on the terrestrial water cycle, a process-based approach to model parameter estimation, and appropriate parameterizations to represent large-scale fluxes and scaling behavior; (3) maintaining a balance between model complexity and data availability as well as uncertainties; and (4) quantifying and communicating significant advancements toward these modeling goals.

  2. Accelerating advances in continental domain hydrologic modeling

    NASA Astrophysics Data System (ADS)

    Archfield, Stacey A.; Clark, Martyn; Arheimer, Berit; Hay, Lauren E.; McMillan, Hilary; Kiang, Julie E.; Seibert, Jan; Hakala, Kirsti; Bock, Andrew; Wagener, Thorsten; Farmer, William H.; Andréassian, Vazken; Attinger, Sabine; Viglione, Alberto; Knight, Rodney; Markstrom, Steven; Over, Thomas

    2015-12-01

    In the past, hydrologic modeling of surface water resources has mainly focused on simulating the hydrologic cycle at local to regional catchment modeling domains. There now exists a level of maturity among the catchment, global water security, and land surface modeling communities such that these communities are converging toward continental domain hydrologic models. This commentary, written from a catchment hydrology community perspective, provides a review of progress in each community toward this achievement, identifies common challenges the communities face, and details immediate and specific areas in which these communities can mutually benefit one another from the convergence of their research perspectives. Those include: (1) creating new incentives and infrastructure to report and share model inputs, outputs, and parameters in data services and open access, machine-independent formats for model replication or reanalysis; (2) ensuring that hydrologic models have: sufficient complexity to represent the dominant physical processes and adequate representation of anthropogenic impacts on the terrestrial water cycle, a process-based approach to model parameter estimation, and appropriate parameterizations to represent large-scale fluxes and scaling behavior; (3) maintaining a balance between model complexity and data availability as well as uncertainties; and (4) quantifying and communicating significant advancements toward these modeling goals.

  3. Inter-comparison of subglacial hydrological models

    NASA Astrophysics Data System (ADS)

    de Fleurian, Basile; Werder, Mauro

    2016-04-01

    The recent emergence of a number of subglacial hydrological models allows us to obtain theoretical insights on basal processes; for instance on the coupling between water pressure and the sliding of glaciers. In ice-flow models, it is relatively clear what the simulated physics ought to be. Conversely, the physical processes incorporated into subglacial hydrology models are diverse as it is yet unclear which ones are of relevance for a particular setting. An inter-comparison of hydrology models will therefore need a somewhat different approach to the one used in the many ice-flow model inter-comparisons (EISMINT, ISMIP, etc.). Here, we present a set of experiments that will allow the comparison of the behavior of different hydrology models. The design of the benchmark aims at allowing the participation of a wide range of models based on different physical approaches. We aim at evaluating the models with a focus on the effective pressure which has the most impact on the dynamics of glaciers. The aim of this inter-comparison is to provide modellers with the necessary data to make an informed decision on which subglacial hydrology model to use for a particular study.

  4. Cost-Effectiveness of HBV and HCV Screening Strategies – A Systematic Review of Existing Modelling Techniques

    PubMed Central

    Geue, Claudia; Wu, Olivia; Xin, Yiqiao; Heggie, Robert; Hutchinson, Sharon; Martin, Natasha K.; Fenwick, Elisabeth; Goldberg, David

    2015-01-01

    Introduction Studies evaluating the cost-effectiveness of screening for Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) are generally heterogeneous in terms of risk groups, settings, screening intervention, outcomes and the economic modelling framework. It is therefore difficult to compare cost-effectiveness results between studies. This systematic review aims to summarise and critically assess existing economic models for HBV and HCV in order to identify the main methodological differences in modelling approaches. Methods A structured search strategy was developed and a systematic review carried out. A critical assessment of the decision-analytic models was carried out according to the guidelines and framework developed for assessment of decision-analytic models in Health Technology Assessment of health care interventions. Results The overall approach to analysing the cost-effectiveness of screening strategies was found to be broadly consistent for HBV and HCV. However, modelling parameters and related structure differed between models, producing different results. More recent publications performed better against a performance matrix, evaluating model components and methodology. Conclusion When assessing screening strategies for HBV and HCV infection, the focus should be on more recent studies, which applied the latest treatment regimes, test methods and had better and more complete data on which to base their models. In addition to parameter selection and associated assumptions, careful consideration of dynamic versus static modelling is recommended. Future research may want to focus on these methodological issues. In addition, the ability to evaluate screening strategies for multiple infectious diseases, (HCV and HIV at the same time) might prove important for decision makers. PMID:26689908

  5. HBV cure: why, how, when?

    PubMed

    Levrero, Massimo; Testoni, Barbara; Zoulim, Fabien

    2016-06-01

    Current HBV treatments control replication and liver disease progression in the vast majority of treated patients. However, HBV patients often require lifelong therapies due to the persistence of transcriptionally active viral cccDNA mini-chromosome in the nucleus, which is not directly targeted by current antiviral therapies. A true complete cure of HBV would require clearance of intranuclear cccDNA from all infected hepatocytes. An intermediate but still relevant step forward that would allow treatment cessation would be reaching a functional cure, equivalent to resolved acute infection, with a durable HBsAg loss±anti-HBs seroconversion, undetectable serum DNA and persistence of cccDNA in a transcriptionally inactive status. Recent advances in technologies and pharmaceutical sciences, including the cloning of the mayor HBV receptor (i.e. the NTCP transporter) and the development in vitro HBV infection models, have heralded a new horizon of innovative antiviral and immune-therapeutic approaches. PMID:27447092

  6. Quantile hydrologic model selection and uncertainty assessment

    NASA Astrophysics Data System (ADS)

    Pande, S.; Keyzer, M. A.; Savenije, H.; Gosain, A. K.

    2010-12-01

    Inapplicability of state of the art hydrological models due to scarce data motivates the need for a modeling approach that can be well constrained to available data and still model dominant processes. Such an approach requires embedded model relationships to be simple and parsimonious in parameters for robust model selection. Simplicity in functional relationship is also important from water management point of view if these models are to be coupled with economic system models for meaningful policy assessment. We propose a semi-distributed approach wherein we model already known dominant processes in dryland areas of Western India (evaporation, Hortonian overland flows, transmission loses and subsurface flows) in a simple but constrained manner through mathematical programming of relevant equations and constraints. Diverse data sources such as GRACE, MERRA reanalysis data, FAO soil texture map and even Indian Agricultural Census data are used. Such a modeling approach allows uncertainty quantification through quantile parameter estimation, which we present in this talk. Quantile estimation transfers uncertainty due to hydrologic model misspecification or data uncertainty, based on quantiles of residuals, onto parameters of the hydrologic model with a fixed structure. An adaptation of quantile regression to parsimonious hydrologic model estimation, this frequentist approach seeks to complement existing Bayesian approaches to model parameter and prediction uncertainty.

  7. On the Use of Models in Hydrology.

    ERIC Educational Resources Information Center

    de Marsily, G.

    1994-01-01

    This discussion article addresses the nature of models used in hydrology. It proposes a minimalist classification of models into two categories: models built on data from observations of the processes involved, and those for which there are no observation data on any of these processes, at the scale of interest. (LZ)

  8. 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.

  9. Developing community infrastructure for hydrologic modeling

    NASA Astrophysics Data System (ADS)

    Arrigo, Jennifer

    2011-08-01

    Third Workshop on the Community Hydrologic Modeling Platform (CHyMP): A Strategic and Implementation Plan; Irvine, California, 15-17 March 2011; The objective of the Community Hydrologic Modeling Platform (CHyMP), a grassroots effort begun in 2008, is to build the cyberinfrastructure and human infrastructure for community-driven, integrated model development and comprehensive data set compilation, as well as a framework for model distribution, high-performance computing access, and technical support. CHyMP recognizes that it is difficult to evaluate and access many existing hydrologic models and the data needed to calibrate them, and these shortcomings impede scientific progress. The third CHyMP workshop, “A Strategic and Implementation Plan,” funded by the U.S. National Science Foundation and the University of California Center for Hydrologic Modeling, brought together more than 30 participants from universities, government agencies, and the private sector to focus on defining steps to begin implementing CHyMP. Participants discussed four aspects critical to community modeling: the data required, the need for benchmarking and intercomparison exercises, the importance of evaluating platforms for such exercises, and the vision of a national water modeling framework.

  10. 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 ...

  11. 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.

  12. 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

  13. Inverse distributed hydrological modelling of Alpine catchments

    NASA Astrophysics Data System (ADS)

    Kunstmann, H.; Krause, J.; Mayr, S.

    2006-06-01

    Even in physically based distributed hydrological models, various remaining parameters must be estimated for each sub-catchment. This can involve tremendous effort, especially when the number of sub-catchments is large and the applied hydrological model is computationally expensive. Automatic parameter estimation tools can significantly facilitate the calibration process. Hence, we combined the nonlinear parameter estimation tool PEST with the distributed hydrological model WaSiM. PEST is based on the Gauss-Marquardt-Levenberg method, a gradient-based nonlinear parameter estimation algorithm. WaSiM is a fully distributed hydrological model using physically based algorithms for most of the process descriptions. WaSiM was applied to the alpine/prealpine Ammer River catchment (southern Germany, 710 km2 in a 100×100 m2 horizontal resolution. The catchment is heterogeneous in terms of geology, pedology and land use and shows a complex orography (the difference of elevation is around 1600 m). Using the developed PEST-WaSiM interface, the hydrological model was calibrated by comparing simulated and observed runoff at eight gauges for the hydrologic year 1997 and validated for the hydrologic year 1993. For each sub-catchment four parameters had to be calibrated: the recession constants of direct runoff and interflow, the drainage density, and the hydraulic conductivity of the uppermost aquifer. Additionally, five snowmelt specific parameters were adjusted for the entire catchment. Altogether, 37 parameters had to be calibrated. Additional a priori information (e.g. from flood hydrograph analysis) narrowed the parameter space of the solutions and improved the non-uniqueness of the fitted values. A reasonable quality of fit was achieved. Discrepancies between modelled and observed runoff were also due to the small number of meteorological stations and corresponding interpolation artefacts in the orographically complex terrain. Application of a 2-dimensional numerical

  14. Modeling the hydrological cycle on Mars

    NASA Astrophysics Data System (ADS)

    Machtoub, G.

    2012-03-01

    The study provides a detailed analysis of the hydrological cycle on Mars simulated with a newly developed microphysical model, incorporated in a spectral Mars General Circulation Model. The modeled hydrological cycle is compared well with simulations of other global climate models. The simulated seasonal migration of water vapor, circulation instability, and the high degree of temporal variability of localized water vapor outbursts are shown closely consistent with recent observations. The microphysical parameterization provides a significant improvement in the modeling of ice clouds evolved over the tropics and major ancient volcanoes on Mars. The most significant difference between the simulations presented here and other GCM results is the level at which the water ice clouds are found. The model findings also support interpretation of observed thermal anomalies in the Martian tropics during northern spring and summer seasons.

  15. 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.

  16. Inverse distributed hydrological modelling of alpine catchments

    NASA Astrophysics Data System (ADS)

    Kunstmann, H.; Krause, J.; Mayr, S.

    2005-12-01

    Even in physically based distributed hydrological models, various remaining parameters must be estimated for each sub-catchment. This can involve tremendous effort, especially when the number of sub-catchments is large and the applied hydrological model is computationally expensive. Automatic parameter estimation tools can significantly facilitate the calibration process. Hence, we combined the nonlinear parameter estimation tool PEST with the distributed hydrological model WaSiM. PEST is based on the Gauss-Marquardt-Levenberg method, a gradient-based nonlinear parameter estimation algorithm. WaSiM is a fully distributed hydrological model using physically based algorithms for most of the process descriptions. WaSiM was applied to the alpine/prealpine Ammer River catchment (southern Germany, 710 km2) in a 100×100 m2 horizontal resolution. The catchment is heterogeneous in terms of geology, pedology and land use and shows a complex orography (the difference of elevation is around 1600 m). Using the developed PEST-WaSiM interface, the hydrological model was calibrated by comparing simulated and observed runoff at eight gauges for the hydrologic year 1997 and validated for the hydrologic year 1993. For each sub-catchment four parameters had to be calibrated: the recession constants of direct runoff and interflow, the drainage density, and the hydraulic conductivity of the uppermost aquifer. Additionally, five snowmelt specific parameters were adjusted for the entire catchment. Altogether, 37 parameters had to be calibrated. Additional a priori information (e.g. from flood hydrograph analysis) narrowed the parameter space of the solutions and improved the non-uniqueness of the fitted values. A reasonable quality of fit was achieved. Discrepancies between modelled and observed runoff were also due to the small number of meteorological stations and corresponding interpolation artefacts in the orographically complex terrain. A detailed covariance analysis was performed

  17. TUWmodel: an educational hydrologic model in R

    NASA Astrophysics Data System (ADS)

    Parajka, J.; Rogger, M.; Kobler, U.; Salinas, J.; Nester, T.; Bloeschl, G.

    2013-12-01

    In order to show the advantages of using hydrologic models in R environment, particularly for educational purposes, we have implemented a conceptual rainfall-runoff model, originally written in Fortran language into R. This hydrologic model is used in many scientific studies and operational engineering applications in Austria. The model consisting of a snow, a soil moisture and a flow routing routine and run on a daily time step in a lumped or a semi-lumped way. The R environment allows to compile and use this model on different platforms and operating system, taking advantage of many additional routines already available in R (i.e. visualisation or optimisation tools). In this poster we present a set of examples that are used in a graduate level course on engineering hydrology at the Vienna University of Technology, which include: - Multi-objective calibration of the model; - Manual vs. automatic calibration; - Visualisation of model outputs and efficiencies; - Model application in ungauged catchments; - Operational runoff forecast. The flexibility of R is ideal for education, since students can easily play with the extensive list of existing functionalities and define new functions and extensions.

  18. Towards Better Coupling of Hydrological Simulation Models

    NASA Astrophysics Data System (ADS)

    Penton, D.; Stenson, M.; Leighton, B.; Bridgart, R.

    2012-12-01

    Standards for model interoperability and scientific workflow software provide techniques and tools for coupling hydrological simulation models. However, model builders are yet to realize the benefits of these and continue to write ad hoc implementations and scripts. Three case studies demonstrate different approaches to coupling models, the first using tight interfaces (OpenMI), the second using a scientific workflow system (Trident) and the third using a tailored execution engine (Delft Flood Early Warning System - Delft-FEWS). No approach was objectively better than any other approach. The foremost standard for coupling hydrological models is the Open Modeling Interface (OpenMI), which defines interfaces for models to interact. An implementation of the OpenMI standard involves defining interchange terms and writing a .NET/Java wrapper around the model. An execution wrapper such as OatC.GUI or Pipistrelle executes the models. The team built two OpenMI implementations for eWater Source river system models. Once built, it was easy to swap river system models. The team encountered technical challenges with versions of the .Net framework (3.5 calling 4.0) and with the performance of the execution wrappers when running daily simulations. By design, the OpenMI interfaces are general, leaving significant decisions around the semantics of the interfaces to the implementer. Increasingly, scientific workflow tools such as Kepler, Taverna and Trident are able to replace custom scripts. These tools aim to improve the provenance and reproducibility of processing tasks. In particular, Taverna and the myExperiment website have had success making many bioinformatics workflows reusable and sharable. The team constructed Trident activities for hydrological software including IQQM, REALM and eWater Source. They built an activity generator for model builders to build activities for particular river systems. The models were linked at a simulation level, without any daily time

  19. Application of SMOS and ASCAT soil moisture estimations to hydrological modelling in Serbia

    NASA Astrophysics Data System (ADS)

    Zlatanovic, Nikola; Ivkovic, Marija; Drobnjak, Aleksandar

    2016-04-01

    This study explores the performance of satellite-based soil moisture products from satellites SMOS (Soil Moisture and Ocean Salinity, measuring brightness temperatures in the L-Band at 1.4 GHz) and ASCAT (Advanced SCATterometer, measuring surface backscattering coefficients in the C-band at 5.255 GHz) for hydrological application. Firstly, SMOS and ASCAT Level 2 soil moisture data were compared to in situ data over Serbia at available sites. All available in situ ground-based point measurements of soil moisture, from the Republic Hydrometeorological Service of Serbia and other independent stations, were collected for the overlapping period with satellite observations and compared against remotely sensed satellite-based soil moisture products. Two approaches are presented in this study to evaluate the applicability of satellite-based SMOS and ASCAT soil moisture products to basin-scale hydrological modelling in a case study catchment in Serbia. The first approach was based on a continuous conceptual forecast-based rainfall-runoff model (using distributed HBV model), where satellite-based soil moisture data helped perform corrections to calculated model soil moisture. The second approach analysed individual event-based rainfall-runoff modelling (using HEC-HMS), where initial (pre-event) model parameters were estimated using satellite-based soil moisture data. Both approaches involved calibration of the hydrological models with and without satellite-based soil moisture data on a case study in Serbia.

  20. Assimilating GRACE terrestrial water storage data into a conceptual hydrology model for the River Rhine

    NASA Astrophysics Data System (ADS)

    Widiastuti, E.; Steele-Dunne, S. C.; Gunter, B.; Weerts, A.; van de Giesen, N.

    2009-12-01

    Terrestrial water storage (TWS) is a key component of the terrestrial and global hydrological cycles, and plays a major role in the Earth’s climate. The Gravity Recovery and Climate Experiment (GRACE) twin satellite mission provided the first space-based dataset of TWS variations, albeit with coarse resolution and limited accuracy. Here, we examine the value of assimilating GRACE observations into a well-calibrated conceptual hydrology model of the Rhine river basin. In this study, the ensemble Kalman filter (EnKF) and smoother (EnKS) were applied to assimilate the GRACE TWS variation data into the HBV-96 rainfall run-off model, from February 2003 to December 2006. Two GRACE datasets were used, the DMT-1 models produced at TU Delft, and the CSR-RL04 models produced by UT-Austin . Each center uses its own data processing and filtering methods, yielding two different estimates of TWS variations and therefore two sets of assimilated TWS estimates. To validate the results, the model estimated discharge after the data assimilation was compared with measured discharge at several stations. As expected, the updated TWS was generally somewhere between the modeled and observed TWS in both experiments and the variance was also lower than both the prior error covariance and the assumed GRACE observation error. However, the impact on the discharge was found to depend heavily on the assimilation strategy used, in particular on how the TWS increments were applied to the individual storage terms of the hydrology model.

  1. Enhancements for Hydrological Modeling in ESMF

    NASA Astrophysics Data System (ADS)

    Deluca, C.; Oehmke, R.; Neckels, D.; Theurich, G.; O'Kuinghttons, R.; de Fainchtein, R.; Murphy, S.; Dunlap, R.

    2008-12-01

    Hydrological systems connect Earth's global physical phenomena with the local environmental impacts that affect our food, health, finances, and homes. The scales and processes that hydrological modelers must span are reflected in the challenges of developing infrastructure for this community. The basic requirements - the need to assemble and couple model components, the need for efficient I/O, the need for integrated visualization, analysis, and data services - are shared with other domains, such as climate and space weather. Where hydrology goes beyond other domains is in its terrific heterogeneity. The diversity of models, data structures, grids, computing platforms, computing languages, and specialized sub-domains involved is daunting. It's not surprising that the hydrological community has spawned a variety of different integrative efforts and frameworks, with distinctly different approaches. This talk will outline how the Earth System Modeling Framework (ESMF), which began in realm of high performance computing for the climate and weather domain, has begun to address the needs of hydrological modelers. We will describe ESMF's new mesh and observational data stream data structures, which join its structured grids and lower-level, index-space constructs as options for data representation, and the flexible, parallel regridding services that can interpolate data between them. The ESMF team is exploring a service oriented architecture approach to computing language and platform diversity, and to interfacing with other standard frameworks. We have also implemented C interfaces for optimized coupling between C and Fortran codes on traditional high performance computing platforms. To address the variety of components available, distributed communities, and integration with data and other services, ESMF has been exhancing its ability to store and write standard component and field metadata, and to link that metadata with full-service science portals. This enables

  2. 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.

  3. Grid-Xinanjiang Distributed Hydrologic Model

    NASA Astrophysics Data System (ADS)

    Li, Z.; Yao, C.; Yu, Z.

    2009-12-01

    The grid-based distributed Xinanjiang (Grid-Xinanjiang) model by combining the well-tested conceptual rainfall-runoff model and the physically based flow routing model has been developed for hydrologic processes simulation and flood forecasting. The DEM is utilized to derive the flow direction, routing sequencing, hillslope and channel slopes. The developed model includes canopy interception, direct channel precipitation, evapotranspiration, as well as runoff generation via saturation excess mechanism. The diffusion wave considering the influent of upstream inflow, direct channel precipitation and flow partition to the channels is developed to route the hillslope and channel flow on a cell basis. The Grid-Xinanjiang model is applied at a 1-km grid scale in a nested basin located in Huaihe basin, China. The basin with the drainage area of 2692.7 km2, contains five internal points where observed streamflow data are available, and is used to evaluate the developed model for its’ ability on the simulation of hydrologic processes within the basin. Calibration and verification of the Grid-Xinanjiang model are carried out at both daily and hourly time steps. The model is assessed by comparing streamflow and water stage simulation to observations at the basin outlet and gauging stations within the basin and also compared with these simulated with the original Xinanjiang model. The results indicate that the parameter estimation approach is efficient and the developed model can forecast the streamflow and stage hydrograph well.

  4. 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.

  5. Proving the ecosystem value through hydrological modelling

    NASA Astrophysics Data System (ADS)

    Dorner, W.; Spachinger, K.; Porter, M.; Metzka, R.

    2008-11-01

    Ecosystems provide valuable functions. Also natural floodplains and river structures offer different types of ecosystem functions such as habitat function, recreational area and natural detention. From an economic stand point the loss (or rehabilitation) of these natural systems and their provided natural services can be valued as a damage (or benefit). Consequently these natural goods and services must be economically valued in project assessments e.g. cost-benefit-analysis or cost comparison. Especially in smaller catchments and river systems exists significant evidence that natural flood detention reduces flood risk and contributes to flood protection. Several research projects evaluated the mitigating effect of land use, river training and the loss of natural flood plains on development, peak and volume of floods. The presented project analysis the hypothesis that ignoring natural detention and hydrological ecosystem services could result in economically inefficient solutions for flood protection and mitigation. In test areas, subcatchments of the Danube in Germany, a combination of hydrological and hydrodynamic models with economic evaluation techniques was applied. Different forms of land use, river structure and flood protection measures were assed and compared from a hydrological and economic point of view. A hydrodynamic model was used to simulate flows to assess the extent of flood affected areas and damages to buildings and infrastructure as well as to investigate the impacts of levees and river structure on a local scale. These model results provided the basis for an economic assessment. Different economic valuation techniques, such as flood damage functions, cost comparison method and substation-approach were used to compare the outcomes of different hydrological scenarios from an economic point of view and value the ecosystem service. The results give significant evidence that natural detention must be evaluated as part of flood mitigation projects

  6. Global-scale regionalization of hydrologic model parameters

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    Current state-of-the-art models typically applied at continental to global scales (hereafter called macro-scale) tend to use a priori parameters, resulting in suboptimal streamflow (Q) simulation. For the first time, a scheme for regionalization of model parameters at the global scale was developed. We used data from a diverse set of 1787 small-to-medium sized catchments (10--10 000~km^2) and the simple conceptual HBV model to set up and test the scheme. Each catchment was calibrated against observed daily Q, after which 674 catchments with high calibration and validation scores, and thus presumably good-quality observed Q and forcing data, were selected to serve as donor catchments. The calibrated parameter sets for the donors were subsequently transferred to 0.5° grid cells with similar climatic and physiographic characteristics, resulting in parameter maps for HBV with global coverage. For each grid cell, we used the ten most similar donor catchments, rather than the single most similar donor, and averaged the resulting simulated Q, which enhanced model performance. The 1113 catchments not used as donors were used to independently evaluate the scheme. The regionalized parameters outperformed spatially-uniform (i.e., averaged calibrated) parameters for 79~% of the evaluation catchments. Substantial improvements were evident for all major Köppen-Geiger climate types and even for evaluation catchments >5000~km distance from the donors. The median improvement was about half of the performance increase achieved through calibration. HBV using regionalized parameters outperformed nine state-of-the-art macro-scale models, suggesting these might also benefit from the new regionalization scheme. The produced HBV parameter maps including ancillary data are available via http://water.jrc.ec.europa.eu/HBV/.

  7. An operational GLS model for hydrologic regression

    USGS Publications Warehouse

    Tasker, Gary D.; Stedinger, J.R.

    1989-01-01

    Recent Monte Carlo studies have documented the value of generalized least squares (GLS) procedures to estimate empirical relationships between streamflow statistics and physiographic basin characteristics. This paper presents a number of extensions of the GLS method that deal with realities and complexities of regional hydrologic data sets that were not addressed in the simulation studies. These extensions include: (1) a more realistic model of the underlying model errors; (2) smoothed estimates of cross correlation of flows; (3) procedures for including historical flow data; (4) diagnostic statistics describing leverage and influence for GLS regression; and (5) the formulation of a mathematical program for evaluating future gaging activities. ?? 1989.

  8. Mechanism of Adefovir, Tenofovir and Entecavir Resistance: Molecular Modeling Studies of How A Novel Anti-HBV Agent (FMCA) Can Overcome the Drug Resistance.

    PubMed

    Rawal, R K; Konreddy, A K; Chu, C K

    2015-01-01

    Regardless of significant improvement in the area of anti-HBV therapy, resistance and cross-resistance against available therapeutic agents are the major consideration in drug discovery of new agents. The present study is to obtain the insight of the molecular basis of drug resistance conferred by the B and C domain mutations of HBV-polymerase on the binding affinity of four anti-HBV agents [Adefovir (ADV), Tenofovir (TNF), Entecavir (ETV) & 2'-Fluoro-6'-methylene-carbocyclic adenosine (FMCA)]. In this regard, homology modeled structure of HBV polymerase was used for minimization, conformational search and Glide XP docking followed by binding energy calculation on wild-type as well as on mutant HBV-polymerases (N236T, L180M+M204V+S202G & A194T). Our studies suggest a significant correlation between the fold resistances and the binding affinity of anti-HBV nucleosides. The domain B residue, L180 is indirectly associated with other active-site hydrophobic residues such as A87, F88 and M204, whereas the domain C residue, M204 is closely associated with sugar/pseudosugar ring positioning in the active site. These hydrophobic residues can directly influence the interaction of the incoming nucleoside triphosphates and change the binding efficacy. The carbohydrate ring part of natural substrate dATP, dGTP, FMCA and ETV, are occupied in similar passion in the grooves of HBV polymerase active site. The exocyclic double bond of Entecavir and FMCA occupies in the backside hydrophobic pocket (made by residues A87, F88, L180and M204), which enhances the overall binding affinity. Additional hydrogen bonding interaction of 2'-fluorine of FMCA with R41 residue of polymerase promotes a positive binding in wild-type as well as in ADVr, ETVr and TNFr with respect to that of entecavir. PMID:26336997

  9. 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.

  10. Hybrid Modelling Approach to Prairie hydrology: Fusing Data-driven and Process-based Hydrological Models

    NASA Astrophysics Data System (ADS)

    Mekonnen, B.; Nazemi, A.; Elshorbagy, A.; Mazurek, K.; Putz, G.

    2012-04-01

    Modeling the hydrological response in prairie regions, characterized by flat and undulating terrain, and thus, large non-contributing areas, is a known challenge. The hydrological response (runoff) is the combination of the traditional runoff from the hydrologically contributing area and the occasional overflow from the non-contributing area. This study provides a unique opportunity to analyze the issue of fusing the Soil and Water Assessment Tool (SWAT) and Artificial Neural Networks (ANNs) in a hybrid structure to model the hydrological response in prairie regions. A hybrid SWAT-ANN model is proposed, where the SWAT component and the ANN module deal with the effective (contributing) area and the non-contributing area, respectively. The hybrid model is applied to the case study of Moose Jaw watershed, located in southern Saskatchewan, Canada. As an initial exploration, a comparison between ANN and SWAT models is established based on addressing the daily runoff (streamflow) prediction accuracy using multiple error measures. This is done to identify the merits and drawbacks of each modeling approach. It has been found out that the SWAT model has better performance during the low flow periods but with degraded efficiency during periods of high flows. The case is different for the ANN model as ANNs exhibit improved simulation during high flow periods but with biased estimates during low flow periods. The modelling results show that the new hybrid SWAT-ANN model is capable of exploiting the strengths of both SWAT and ANN models in an integrated framrwork. The new hybrid SWAT-ANN model simulates daily runoff quite satisfactorily with NSE measures of 0.80 and 0.83 during calibration and validation periods, respectively. Furthermore, an experimental assessment was performed to identify the effects of the ANN training method on the performance of the hybrid model as well as the parametric identifiability. Overall, the results obtained in this study suggest that the fusion

  11. Modeling hydrologic and ecologic responses using a new eco-hydrological model for identification of droughts

    NASA Astrophysics Data System (ADS)

    Sawada, Yohei; Koike, Toshio; Jaranilla-Sanchez, Patricia Ann

    2014-07-01

    Drought severely damages water and agricultural resources, and both hydrological and ecological responses are important for its understanding. First, precipitation deficit induces soil moisture deficiency and high plant water stress causing agricultural droughts. Second, hydrological drought characterized by deficit of river discharge and groundwater follows agricultural drought. However, contributions of vegetation dynamics to these processes at basin scale have not been quantified. To address this issue, we develop an eco-hydrological model that can calculate river discharge, groundwater, energy flux, and vegetation dynamics as diagnostic variables at basin scale within a distributed hydrological modeling framework. The model is applied to drought analysis in the Medjerda River basin. From model inputs and outputs, we calculate drought indices for different drought types. The model shows reliable accuracy in reproducing observed river discharge in long-term (19 year) simulation. Moreover, the drought index calculated from the model-estimated annual peak of leaf area index correlates well (correlation coefficient r = 0.89) with the drought index from nationwide annual crop production, which demonstrates that the modeled leaf area index is capable of representing agricultural droughts related to historical food shortages. We show that vegetation dynamics have a more rapid response to meteorological droughts than river discharge and groundwater dynamics in the Medjerda basin because vegetation dynamics are sensitive to soil moisture in surface layers, whereas soil moisture in deeper layers strongly contributes to streamflow and groundwater level. Our modeling framework can contribute to analyze drought progress, although analyses for other climate conditions are needed.

  12. Attributing spatial patterns of hydrological model performance

    NASA Astrophysics Data System (ADS)

    Eisner, S.; Malsy, M.; Flörke, M.

    2013-12-01

    Global hydrological models and land surface models are used to understand and simulate the global terrestrial water cycle. They are, in particular, applied to assess the current state of global water resources, to identify anthropogenic pressures on the global water system, and to assess impacts of global and climate change on water resources. Especially in data-scarce regions, the growing availability of remote sensing products, e.g. GRACE estimates of changes in terrestrial water storage, evaporation or soil moisture estimates, has added valuable information to force and constrain these models as they facilitate the calibration and validation of simulated states and fluxes other than stream flow at large spatial scales. Nevertheless, observed discharge records provide important evidence to evaluate the quality of water availability estimates and to quantify the uncertainty associated with these estimates. Most large scale modelling approaches are constrained by simplified physical process representations and they implicitly rely on the assumption that the same model structure is valid and can be applied globally. It is therefore important to understand why large scale hydrological models perform good or poor in reproducing observed runoff and discharge fields in certain regions, and to explore and explain spatial patterns of model performance. We present an extensive evaluation of the global water model WaterGAP (Water - Global Assessment and Prognosis) to simulate 20th century discharges. The WaterGAP modeling framework comprises a hydrology model and several water use models and operates in its current version, WaterGAP3, on a 5 arc minute global grid and . Runoff generated on the individual grid cells is routed along a global drainage direction map taking into account retention in natural surface water bodies, i.e. lakes and wetlands, as well as anthropogenic impacts, i.e. flow regulation and water abstraction for agriculture, industry and domestic purposes as

  13. 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)

  14. A comprehensive validation of HBV-related acute-on-chronic liver failure models to assist decision-making in targeted therapeutics

    PubMed Central

    Shen, Yi; Wang, Xulin; Zhang, Sheng; Qin, Gang; Liu, Yanmei; Lu, Yihua; Liang, Feng; Zhuang, Xun

    2016-01-01

    This research utilized an external longitudinal dataset of hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) to compare and validate various predictive models that support the current recommendations to select the most effective predictive risk models to estimate short- and long-term mortality and facilitate decision-making about preferable therapeutics for HBV-ACLF patients. Twelve ACLF prognostic models were developed after a systematic literature search using the longitudinal data of 232 HBV-ACLF patients on the waiting list for liver transplantation (LT). Four statistical measures, the constant (A) and slope (B) of the fitted line, the area under the curve (C) and the net benefit (D), were calculated to assess and compare the calibration, discrimination and clinical usefulness of the 12 predictive models. According to the model calibration and discrimination, the logistic regression models (LRM2) and the United Kingdom model of end-stage liver disease(UKELD) were selected as the best predictive models for both 3-month and 5-year outcomes. The decision curve summarizes the benefits of intervention relative to the costs of unnecessary treatment. After the comprehensive validation and comparison of the currently used models, LRM2 was confirmed as a markedly effective prognostic model for LT-free HBV-ACLF patients for assisting targeted and standardized therapeutic decisions. PMID:27633520

  15. A comprehensive validation of HBV-related acute-on-chronic liver failure models to assist decision-making in targeted therapeutics.

    PubMed

    Shen, Yi; Wang, Xulin; Zhang, Sheng; Qin, Gang; Liu, Yanmei; Lu, Yihua; Liang, Feng; Zhuang, Xun

    2016-01-01

    This research utilized an external longitudinal dataset of hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) to compare and validate various predictive models that support the current recommendations to select the most effective predictive risk models to estimate short- and long-term mortality and facilitate decision-making about preferable therapeutics for HBV-ACLF patients. Twelve ACLF prognostic models were developed after a systematic literature search using the longitudinal data of 232 HBV-ACLF patients on the waiting list for liver transplantation (LT). Four statistical measures, the constant (A) and slope (B) of the fitted line, the area under the curve (C) and the net benefit (D), were calculated to assess and compare the calibration, discrimination and clinical usefulness of the 12 predictive models. According to the model calibration and discrimination, the logistic regression models (LRM2) and the United Kingdom model of end-stage liver disease(UKELD) were selected as the best predictive models for both 3-month and 5-year outcomes. The decision curve summarizes the benefits of intervention relative to the costs of unnecessary treatment. After the comprehensive validation and comparison of the currently used models, LRM2 was confirmed as a markedly effective prognostic model for LT-free HBV-ACLF patients for assisting targeted and standardized therapeutic decisions. PMID:27633520

  16. 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.

  17. Rethinking the pathogenesis of hepatitis B virus (HBV) infection.

    PubMed

    Zhang, Yong-Yuan; Hu, Ke-Qin

    2015-12-01

    Chronic hepatitis B virus (HBV) infection affects approximately 375 million people worldwide. Current antiviral treatment effectively controls, but rarely clears chronic HBV infection. In addition, a significant portion of chronic HBV infected patients are not suitable for currently available antiviral therapy, and still face higher risk for cirrhosis and hepatocellular carcinoma. The poorly understood pathogenesis of HBV infection is the main barrier for developing more effective treatment strategies. HBV has long been viewed as non-cytopathic and the central hypothesis for HBV pathogenesis lies in the belief that hepatitis B is a host specific immunity-mediated liver disease. However, this view has been challenged by the accumulating experimental and clinical data that support a model of cytopathic HBV replication. In this article we systematically review the pathogenic role of HBV replication in hepatitis B and suggest possible HBV replication related mechanisms for HBV-mediated liver injury. We propose that a full understanding of HBV pathogenesis should consider the following elements. I. Liver injury can be caused by high levels of HBV replication and accumulation of viral products in the infected hepatocytes. II. HBV infection can be either directly cytopathic, non-cytopathic, or a mix of both in an individual patient depending upon accumulation levels of viral products that are usually associated with HBV replication activity in individual infected hepatocytes.

  18. 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

  19. Hydrological model uncertainty assessment in southern Africa

    NASA Astrophysics Data System (ADS)

    Hughes, D. A.; Kapangaziwiri, E.; Sawunyama, T.

    2010-06-01

    The importance of hydrological uncertainty analysis has been emphasized in recent years and there is an urgent need to incorporate uncertainty estimation into water resources assessment procedures used in the southern Africa region. The region is characterized by a paucity of accurate data and limited human resources, but the need for informed development decisions is critical to social and economic development. One of the main sources of uncertainty is related to the estimation of the parameters of hydrological models. This paper proposes a framework for establishing parameter values, exploring parameter inter-dependencies and setting parameter uncertainty bounds for a monthly time-step rainfall-runoff model (Pitman model) that is widely used in the region. The method is based on well-documented principles of sensitivity and uncertainty analysis, but recognizes the limitations that exist within the region (data scarcity and accuracy, model user attitudes, etc.). Four example applications taken from different climate and physiographic regions of South Africa illustrate that the methods are appropriate for generating behavioural stream flow simulations which include parameter uncertainty. The parameters that dominate the model response and their degree of uncertainty vary between regions. Some of the results suggest that the uncertainty bounds will be too wide for effective water resources decision making. Further work is required to reduce some of the subjectivity in the methods and to investigate other approaches for constraining the uncertainty. The paper recognizes that probability estimates of uncertainty and methods to include input climate data uncertainties need to be incorporated into the framework in the future.

  20. Uncertainty Analysis of the Ensemble Hydrological Forecasts in the Coupled Meteorological-Hydrological Modelling Environment

    NASA Astrophysics Data System (ADS)

    Xuan, Y.; Cluckie, I. D.

    2006-12-01

    The advances in meso-scale numerical weather predication render hydrologists the capability to incorporate high-resolution NWP directly into flood forecasting systems in order to obtain an extended lead time. However, such a direct application of rainfall outputs from the NWP model can contribute considerable uncertainties to the final river flow forecasts as the uncertainties inherent in the NWP are propagated into hydrological domains and can also be highlighted by the scaling process. In this research, the ensemble hydrological forecasts driven by the ensemble weather prediction are investigated in an effort trying to understand both the potential and the implication of the ensemble rainfall inputs to the hydrological modelling systems in terms of uncertainty propagation. A data-rich catchment facilitated with dense rainguage network as well as high resolution weather radar was chosen to run the ensemble hydrological simulations of a distributed hydrological model driven by the high resolution NWP predictions. The uncertainties of the amount and the location/timing of the rainfall prediction are discussed whith the results showing that: (1) the hydrological model driven by the short-range NWP can produce forecasts comparable with those from a raingauge-driven one; (2) the ensemble hydrological forecast is able to disseminate abundant information with regard to the nature of the weather system and the confidence of the forecast itself; and (3) the uncertainties as well as systematical biases sometimes are significantly large and, as such, extra efforts need to be made to improve the quality of such a system.

  1. Global-scale regionalization of hydrologic model parameters

    NASA Astrophysics Data System (ADS)

    Beck, Hylke E.; van Dijk, Albert I. J. M.; de Roo, Ad; Miralles, Diego G.; McVicar, Tim R.; Schellekens, Jaap; Bruijnzeel, L. Adrian

    2016-05-01

    Current state-of-the-art models typically applied at continental to global scales (hereafter called macroscale) tend to use a priori parameters, resulting in suboptimal streamflow (Q) simulation. For the first time, a scheme for regionalization of model parameters at the global scale was developed. We used data from a diverse set of 1787 small-to-medium sized catchments (10-10,000 km2) and the simple conceptual HBV model to set up and test the scheme. Each catchment was calibrated against observed daily Q, after which 674 catchments with high calibration and validation scores, and thus presumably good-quality observed Q and forcing data, were selected to serve as donor catchments. The calibrated parameter sets for the donors were subsequently transferred to 0.5° grid cells with similar climatic and physiographic characteristics, resulting in parameter maps for HBV with global coverage. For each grid cell, we used the 10 most similar donor catchments, rather than the single most similar donor, and averaged the resulting simulated Q, which enhanced model performance. The 1113 catchments not used as donors were used to independently evaluate the scheme. The regionalized parameters outperformed spatially uniform (i.e., averaged calibrated) parameters for 79% of the evaluation catchments. Substantial improvements were evident for all major Köppen-Geiger climate types and even for evaluation catchments > 5000 km distant from the donors. The median improvement was about half of the performance increase achieved through calibration. HBV with regionalized parameters outperformed nine state-of-the-art macroscale models, suggesting these might also benefit from the new regionalization scheme. The produced HBV parameter maps including ancillary data are available via www.gloh2o.org.

  2. Combined effects of climate models, hydrological model structures and land use scenarios on hydrological impacts of climate change

    NASA Astrophysics Data System (ADS)

    Karlsson, Ida B.; Sonnenborg, Torben O.; Refsgaard, Jens Christian; Trolle, Dennis; Børgesen, Christen Duus; Olesen, Jørgen E.; Jeppesen, Erik; Jensen, Karsten H.

    2016-04-01

    Impact studies of the hydrological response of future climate change are important for the water authorities when risk assessment, management and adaptation to a changing climate are carried out. The objective of this study was to model the combined effect of land use and climate changes on hydrology for a 486 km2 catchment in Denmark and to evaluate the sensitivity of the results to the choice of hydrological model. Three hydrological models, NAM, SWAT and MIKE SHE, were constructed and calibrated using similar methods. Each model was forced with results from four climate models and four land use scenarios. The results revealed that even though the hydrological models all showed similar performance during calibration, the mean discharge response to climate change varied up to 30%, and the variations were even higher for extreme events (1th and 99th percentile). Land use changes appeared to cause little change in mean hydrological responses and little variation between hydrological models. Differences in hydrological model responses to land use were, however, significant for extremes due to dissimilarities in hydrological model structure and process equations. The climate model choice remained the dominant factor for mean discharge, low and high flows as well as hydraulic head at the end of the century.

  3. Constraining hydrologic models using thermal analysis

    SciTech Connect

    Doughty, Christine; Karasaki, Kenzi

    2002-12-12

    Starting with regional geographic, geologic, hydrologic, geophysical, and meteorological data for the Tono area in Gifu, Japan, we develop a numerical model to simulate subsurface flow and transport in a 4 km by 6 km by 3 km thick fractured granite rock mass overlain by sedimentary layers. Individual fractures are not modeled explicitly. Rather, continuum permeability and porosity distributions are assigned stochastically, based on well-test data and fracture density measurements. The primary goal of the study is to simulate steady-state groundwater flow through the site, then calculate travel times to the model boundaries from specified monitoring points. The lateral boundaries of the model follow topographic features such as ridgelines and rivers. Assigning lateral boundary conditions is a major point of uncertainty in model construction. We evaluate two models with opposing boundary conditions: mostly closed and mostly open boundaries. The two models show vastly different spatial distributions of groundwater flow, so we would like to find a means of choosing the more realistic model. Surface recharge is much larger for the closed model, but field recharge data are of too limited spatial extent to provide a definitive model constraint. Temperature profiles in 16 boreholes show consistent trends with conduction-dominated (linear) temperature profiles below depths of about 300 m. The open and closed models predict strongly different temperature versus depth profiles; with the closed model showing a strong convective signature produced by widespread surface recharge effects to the depth. The open model shows more linear temperature profiles, better agreeing with measurements from the field. Based on this data we can eliminate from consideration the closed model, at least in its present form in which surface recharge penetrates deep into the model.

  4. HBV-DNA levels predict overall mortality in HIV/HBV coinfected individuals.

    PubMed

    Nikolopoulos, Georgios K; Paraskevis, Dimitrios; Psichogiou, Mina; Hatzakis, Angelos

    2016-03-01

    The coinfection of Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) has been associated with increased death rates. However, the relevant research has mostly relied on serologic HBV testing [HBV surface antigen (HBsAg)]. The aim of this work was to explore the relationship of HBV viraemia with overall mortality among HIV/HBV coinfected individuals. The analysis included 1,609 HIV seropositives of a previously described cohort (1984-2003) with limited exposure to tenofovir (12%) and a median follow-up of approximately 5 years. Those with persistent expression of HBsAg were further tested for HBV-DNA. The data were analyzed using Poisson regression models. Totally, 101 participants were chronic carriers of HBsAg (6.28%). Of these, 81 were tested for HBV-DNA. The median HBV-DNA levels were 3.81 log (base-10) International Units (IU)/ml. A third (31%) of those tested for HBV-DNA had received tenofovir. Before developing acquired immune deficiency syndrome (AIDS), the adjusted incidence rate ratio (IRR) for all-cause mortality of coinfected patients with HBV viraemia above the median value versus the HIV monoinfected group was 3.44 [95% confidence interval (CI): 1.05-11.27]. Multivariable regressions in the coinfected group only (n = 81) showed that one log-10 increase in HBV-DNA levels was associated with an elevated risk for death (IRR: 1.24, 95%CI: 1.03-1.49). HBV-DNA levels predict overall mortality in the setting of HIV/HBV coinfection, especially during the period before developing AIDS, and could thus help prioritize needs and determine the frequency of medical monitoring.

  5. Monthly Hydrological Model Evaluation through Mapping the Hydrological Pattern to Information Space

    NASA Astrophysics Data System (ADS)

    Pan, B.; Cong, Z.

    2014-12-01

    Conceptual and stochastic monthly hydrological models have been widely used for climatic change impact exploration and long-range stream flow forecast. With disparate philosophies and different but insufficient inputs, most of the existing models are capable of generating satisfying outputs, which reveals a relatively robust idiosyncrasy of hydrological pattern over monthly time scale. This research uses the epistemic-aleatory uncertainties evaluation framework to examine the information source sink terms and flows of 6 conceptual monthly water balance models and a seasonal autoregressive stochastic hydrologic model over 19 basins in Jiangxi Province, China and the experiment basins of MOPEX project. By using the stream technique of Lisp, we constructed two programming paradigms into which the hydrological models mentioned above could be fitted. We focus on detecting and explaining the best achievable predictive performances and data-revealed insufficient of the models in each paradigm, especially the hydrological meaning of the iteration variables in these models. Finally, we make an attempt to compare and connect these two paradigms against the backdrop of algorithmic information theory to help us form a better understanding of monthly hydrological pattern.

  6. A hydrological model of New Zealand

    NASA Astrophysics Data System (ADS)

    Woods, R. A.; Tarboton, D. G.; Ibbitt, R. P.; Wild, M.; Henderson, R. D.; Turner, R.

    2003-04-01

    We present initial results from a hydrological model of New Zealand, using Topnet, a variant of TOPMODEL, linked to a kinematic wave channel network routing algorithm. This model run uses daily timesteps for the period 1985-2001, and subdivides the country into approximately 35,000 sub-catchments of 7-10 sq km each. The sub-catchments are linked by 55,000 river reaches, which route sub-catchment runoff. The model subcatchments and reaches are defined automatically by DEM analyses, and initial estimates of model parameters are defined by GIS overlay, coupled with purpose-built model assembly code, and lookup tables for model parameters. A daily simulation for 1 year over New Zealand takes two hours on a standard desktop computer. The model is forced by gridded daily rainfall and temperature data, and it calculates daily water balance for each of the sub-catchments (rain, evaporation, throughfall, infiltration, soil drainage, surface runoff, subsurface runoff, and changes in storage in the canopy, root zone, and saturated storage), as well as daily flows in each river reach. The model as currently implemented does not include snow, glaciers, or deep groundwater flow (i.e. across sub-catchment boundaries). The first applications of the model are for developing an annual water balance of New Zealand for the period 1994-2001, at the regional scale, and for driving a high-spatial resolution, daily time-stepping national erosion model. We are moving to further applications for water resource modeling (e.g. impact of abstraction and/or storage), and for flood forecasting, using hourly rainfall from a mesoscale atmospheric model.

  7. The skill of seasonal ensemble low-flow forecasts in the Moselle River for three different hydrological models

    NASA Astrophysics Data System (ADS)

    Demirel, M. C.; Booij, M. J.; Hoekstra, A. Y.

    2015-01-01

    This paper investigates the skill of 90-day low-flow forecasts using two conceptual hydrological models and one data-driven model based on Artificial Neural Networks (ANNs) for the Moselle River. The three models, i.e. HBV, GR4J and ANN-Ensemble (ANN-E), all use forecasted meteorological inputs (precipitation P and potential evapotranspiration PET), whereby we employ ensemble seasonal meteorological forecasts. We compared low-flow forecasts for five different cases of seasonal meteorological forcing: (1) ensemble P and PET forecasts; (2) ensemble P forecasts and observed climate mean PET; (3) observed climate mean P and ensemble PET forecasts; (4) observed climate mean P and PET and (5) zero P and ensemble PET forecasts as input for the models. The ensemble P and PET forecasts, each consisting of 40 members, reveal the forecast ranges due to the model inputs. The five cases are compared for a lead time of 90 days based on model output ranges, whereas the models are compared based on their skill of low-flow forecasts for varying lead times up to 90 days. Before forecasting, the hydrological models are calibrated and validated for a period of 30 and 20 years respectively. The smallest difference between calibration and validation performance is found for HBV, whereas the largest difference is found for ANN-E. From the results, it appears that all models are prone to over-predict runoff during low-flow periods using ensemble seasonal meteorological forcing. The largest range for 90-day low-flow forecasts is found for the GR4J model when using ensemble seasonal meteorological forecasts as input. GR4J, HBV and ANN-E under-predicted 90-day-ahead low flows in the very dry year 2003 without precipitation data. The results of the comparison of forecast skills with varying lead times show that GR4J is less skilful than ANN-E and HBV. Overall, the uncertainty from ensemble P forecasts has a larger effect on seasonal low-flow forecasts than the uncertainty from ensemble PET

  8. Modeling the Interactions between Hydrological Extremes, Water Management and Society.

    NASA Astrophysics Data System (ADS)

    Martinez, Fabian; Di Baldassarre, Giuliano; Kalantari, Zahra

    2016-04-01

    Over the past years, several studies have focused on exploring human impacts on the hydrological regime. Even though the dominant hydrological processes are mostly well understood, there are still several challenges related to modeling the coevolution of human impacts on (and responses to) hydrological extremes, such as floods and droughts. Some initial modeling attempts have proved to capture the essential dynamics emerging from two-way feedbacks between hydrological and social processes. However, they have predominantly focused on flooding. This research aims to develop a new conceptual model unraveling the interplay between hydrological extremes (floods and droughts) and human societies in a changing climate. In particular, this socio-hydrological model aims at understanding, and predicting the dynamics of coupled human-water systems to explain and capture how the occurrence of hydrological extremes changes water management approach, and how such a change (in turn) mitigates the impacts of hydrological extremes. The conceptual model is then applied to a case study to test its ability in simulating the dynamics emerging from the interplay between hydrological and social processes.

  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

  10. Hydrological Modelling of Small Catchments Using Swat

    NASA Astrophysics Data System (ADS)

    Kannan, N.; White, S. M.; Worrall, F.; Groves, S.

    The data from a 142ha catchment in Eastern England(Colworth, Bedfordshire)are be- ing used to investigate the performance of the USDA SWAT software for modelling hydrology of small catchments. Stream flow at the catchment outlet has been mon- itored since October 1999. About 50% of the total catchment is directly controlled within one farm and a rotation of wheat, oil seed rape, grass, linseed, beans and peas is grown. Three years of stream flow and climate data are available. Calibration and validation of stream flow was carried out with both runoff modelling options in the SWAT model (USDA curve number method and the Green and Ampt method). The Nash and Sutcliffe efficiencies for the calibration period were 66% and 63% respec- tively. The performance of SWAT was better in the validation period as a whole, with regard to timing of peaks, baseflow values and Nash and Sutcliffe efficiency. An ef- ficiency of 70% was obtained using the curve number method, which is comparable with the efficiencies obtainable with more complex models. Despite this performance, SWAT is under predicting stream flow peaks. A detailed investigation of important model components, has allowed us to identify some of the reasons for under predic- tion of stream flow peaks.

  11. Hydrological Modelling of Ganga River basin.

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    Application of a hydrological model, Soil and Water Assessment Tool (SWAT) to the Ganga basin having a total drainage area of around 1.08 M sq. km extending over Tibet, Nepal, India and Bangladesh has been made. The model is calibrated to determine the spatial deviations in runoff at sub-basin level, and to capture the water balance of the river basin. Manual calibration approach was used for calibrating the SWAT model by following multi-step procedure to get to the realistic present situation as close as possible. Simulations were then further made with and without proposed future projects to obtain various scenarios. The various statistical parameters used for the evaluation of the monthly runoff simulation showed that SWAT performed well in mimicking the monthly stream flow for Ganga River basin. The model under predicted the flows in the non-perennial region during non-monsoon season, due to low rainfall and regulated flows and seepage taking place from the reservoirs. The impacts of the interventions, both existing as well as proposed, on the water balance of the basin were evaluated and quantified. The derived results suggest that there is a substantial reduction in overall water resources availability in the study basin on account of the current level of development and further, future developments, as are being proposed, may require a careful study of their potential impact on currently sanctioned water use. The present study showcases that efficacy of the model for simulating the stream flow is admirable.

  12. Modelling the hydrological cycle in assessments of climate change

    NASA Technical Reports Server (NTRS)

    Rind, D.; Rosenzweig, C.; Goldberg, R.

    1992-01-01

    The predictions of climate change studies depend crucially on the hydrological cycles embedded in the different models used. It is shown here that uncertainties in hydrological processes and inconsistencies in both climate and impact models limit confidence in current assessments of climate change. A future course of action to remedy this problem is suggested.

  13. A RETROSPECTIVE ANALYSIS OF MODEL UNCERTAINTY FOR FORECASTING HYDROLOGIC CHANGE

    EPA Science Inventory

    GIS-based hydrologic modeling offers a convenient means of assessing the impacts associated with land-cover/use change for environmental planning efforts. Alternative future scenarios can be used as input to hydrologic models and compared with existing conditions to evaluate pot...

  14. A question driven socio-hydrological modeling process

    NASA Astrophysics Data System (ADS)

    Garcia, M.; Portney, K.; Islam, S.

    2015-08-01

    Human and hydrological systems are coupled: human activity impacts the hydrological cycle and hydrological conditions can, but do not always, trigger changes in human systems. Traditional modeling approaches with no feedback between hydrological and human systems typically cannot offer insight into how different patterns of natural variability or human induced changes may propagate through this coupled system. Modeling of coupled human and hydrological systems, also called socio-hydrological systems, recognizes the potential for humans to transform hydrological systems and for hydrological conditions to influence human behavior. However, this coupling introduces new challenges and existing literature does not offer clear guidance regarding the choice of modeling structure, scope, and detail. A shared understanding of important processes within the field is often used to develop hydrological models, but there is no such consensus on the relevant processes in socio-hydrological systems. Here we present a question driven process to address these challenges. Such an approach allows modeling structure, scope, and detail to remain contingent and adaptive to the question context. We demonstrate its utility by exploring a question: what is the impact of reservoir operation policy on the reliability of water supply for a growing city? Our example model couples hydrological and human systems by linking the rate of demand decreases to the past reliability to compare standard operating policy (SOP) with hedging policy (HP). The model shows that reservoir storage acts both as a buffer for variability and as a delay triggering oscillations around a sustainable level of demand. HP reduces the threshold for action thereby decreasing the delay and the oscillation effect. As a result per capita demand decreases during periods of water stress are more frequent but less drastic and the additive effect of small adjustments decreases the tendency of the system to overshoot available

  15. Hydrology

    ERIC Educational Resources Information Center

    Sharp, John M.

    1977-01-01

    Lists many recent research projects in hydrology, including flow in fractured media, improvements in remote-sensing techniques, effects of urbanization on water resources, and developments in drainage basins. (MLH)

  16. Hepatitis B (HBV)

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Hepatitis B (HBV) KidsHealth > For Teens > Hepatitis B (HBV) Print A A A Text Size ... Prevented? How Is It Treated? What Is It? Hepatitis (pronounced: hep-uh-TIE-tiss) is a disease ...

  17. Global scale hydrology - Advances in land surface modeling

    SciTech Connect

    Wood, E.F. )

    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.

  18. Complexity of groundwater models in catchment hydrological models

    NASA Astrophysics Data System (ADS)

    Attinger, Sabine; Herold, Christian; Kumar, Rohini; Mai, Juliane; Ross, Katharina; Samaniego, Luis; Zink, Matthias

    2015-04-01

    In catchment hydrological models, groundwater is usually modeled very simple: it is conceptualized as a linear reservoir that gets the water from the upper unsaturated zone reservoir and releases water to the river system as baseflow. The baseflow is only a minor component of the total river flow and groundwater reservoir parameters are therefore difficult to be inversely estimated by means of river flow data only. In addition, the modelled values of the absolute height of the water filling the groundwater reservoir - in other words the groundwater levels - are of limited meaning due to coarse or no spatial resolution of groundwater and due to the fact that only river flow data are used for the calibration. The talk focuses on the question: Which complexity in terms of model complexity and model resolution is necessary to characterize groundwater processes and groundwater responses adequately in distributed catchment hydrological models? Starting from a spatially distributed catchment hydrological model with a groundwater compartment that is conceptualized as a linear reservoir we stepwise increase the groundwater model complexity and its spatial resolution to investigate which resolution, which complexity and which data are needed to reproduce baseflow and groundwater level data adequately.

  19. The Diagnostic Accuracy and Clinical Utility of Three Noninvasive Models for Predicting Liver Fibrosis in Patients with HBV Infection

    PubMed Central

    Zhang, Zhiqiao; Wang, Gongsui; Kang, Kaifu; Wu, Guobiao; Wang, Peng

    2016-01-01

    Aim To evaluate the diagnostic accuracy and clinical utility of the fibrosis index based on the four factors (FIB-4), aspartate aminotransferase -to-platelet ratio index (APRI), and aspartate aminotransferase–alanine aminotransferase ratio index (AAR) for predicting liver fibrosis in patients with HBV infection. Methods From January 2006 to December 2010,a total of 1543 consecutive chronic hepatitis B(CHB) patients who underwent liver biopsies were enrolled. FIB-4,APRI, and AAR were calculated.The areas under the receiver-operating characteristic curves (AUROCs) were calculated to assess the diagnostic accuracy of these models.The AUROCs of these models were compared by DeLong’s test.For further comparisons in different studies,the AUROCs were adjusted to conduct Adjusted AUROCs(ADjAUROCs) according to the prevalence of fibrosis stages using the difference between advanced and nonadvanced fibrosis (DANA). Results For prediction of significant fibrosis,severe fibrosis,and cirrhosis,the AUROCs of FIB-4 were 0.646(ADjAUROC 0.717),0.670(ADjAUROC 0.741), and 0.715(ADjAUROC 0.786) respectively;whereas it were 0.656(ADjAUROC 0.727),0.653(ADjAUROC 0.724) and 0.639(ADjAUROC 0.710) for APRI, 0.498(ADjAUROC 0.569),0.548(ADjAUROC 0.619) and 0.573(ADjAUROC 0.644) for AAR. The further comparisons demonstrated that there were no significant differences of AUROCs between FIB-4 and APRI in predicting significant and severe fibrosis(P > 0.05),while FIB-4 was superior to APRI in predicting cirrhosis(P < 0.001). Further subgroup analysis demonstrated that the diagnostic accuracy of FIB-4 and APRI in patients with normal alanine aminotransferase(ALT) were higher than that in patients with elevated ALT. Conclusions The results demonstrated that FIB-4 and APRI are useful for diagnosis of fibrosis. FIB-4 and APRI have similar diagnostic accuracy in predicting significant and severe fibrosis,while FIB-4 is superior to APRI in predicting cirrhosis. The clinical utility of FIB-4 and APRI

  20. 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.

  1. 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.

  2. Comparing Sediment Yield Predictions from Different Hydrologic Modeling Schemes

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    Sediment yield, or the delivery of sediment from the landscape to a river, is a difficult process to accurately model. It is primarily a function of hydrology and climate, but influenced by landcover and the underlying soils. These additional factors make it much more difficult to accurately model than water flow alone. It is not intuitive what impact different hydrologic modeling schemes may have on the prediction of sediment yield. Here, two implementations of the Modified Universal Soil Loss Equation (MUSLE) are compared to examine the effects of hydrologic model choice. Both the Soil and Water Assessment Tool (SWAT) and the Landscape Hydrology Model (LHM) utilize the MUSLE for calculating sediment yield. SWAT is a lumped parameter hydrologic model developed by the USDA, which is commonly used for predicting sediment yield. LHM is a fully distributed hydrologic model developed primarily for integrated surface and groundwater studies at the watershed to regional scale. SWAT and LHM models were developed and tested for two large, adjacent watersheds in the Great Lakes region; the Maumee River and the St. Joseph River. The models were run using a variety of single model and ensemble downscaled climate change scenarios from the Coupled Model Intercomparison Project 5 (CMIP5). The initial results of this comparison are discussed here.

  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. Hydrological modeling of the Jiaoyi watershed (China) using HSPF model.

    PubMed

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

    2014-01-01

    A watershed hydrological model, hydrological simulation program-Fortran (HSPF), was applied to simulate the spatial and temporal variation of hydrological processes in the Jiaoyi watershed of Huaihe River Basin, the heaviest shortage of water resources and polluted area in China. The model was calibrated using the years 2001-2004 and validated with data from 2005 to 2006. Calibration and validation results showed that the model generally simulated mean monthly and daily runoff precisely due to the close matching hydrographs between simulated and observed runoff, as well as the excellent evaluation indicators such as Nash-Sutcliffe efficiency (NSE), coefficient of correlation (R (2)), and the relative error (RE). The similar simulation results between calibration and validation period showed that all the calibrated parameters had a certain representation in Jiaoyi watershed. Additionally, the simulation in rainy months was more accurate than the drought months. Another result in this paper was that HSPF was also capable of estimating the water balance components reasonably and realistically in space through the whole watershed. The calibrated model can be used to explore the effects of climate change scenarios and various watershed management practices on the water resources and water environment in the basin. PMID:25013863

  5. Hydrological modeling of the Jiaoyi watershed (China) using HSPF model.

    PubMed

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

    2014-01-01

    A watershed hydrological model, hydrological simulation program-Fortran (HSPF), was applied to simulate the spatial and temporal variation of hydrological processes in the Jiaoyi watershed of Huaihe River Basin, the heaviest shortage of water resources and polluted area in China. The model was calibrated using the years 2001-2004 and validated with data from 2005 to 2006. Calibration and validation results showed that the model generally simulated mean monthly and daily runoff precisely due to the close matching hydrographs between simulated and observed runoff, as well as the excellent evaluation indicators such as Nash-Sutcliffe efficiency (NSE), coefficient of correlation (R (2)), and the relative error (RE). The similar simulation results between calibration and validation period showed that all the calibrated parameters had a certain representation in Jiaoyi watershed. Additionally, the simulation in rainy months was more accurate than the drought months. Another result in this paper was that HSPF was also capable of estimating the water balance components reasonably and realistically in space through the whole watershed. The calibrated model can be used to explore the effects of climate change scenarios and various watershed management practices on the water resources and water environment in the basin.

  6. Revisiting an interdisciplinary hydrological modelling project. A socio-hydrology (?) example from the early 2000s

    NASA Astrophysics Data System (ADS)

    Seidl, Roman; Barthel, Roland

    2016-04-01

    Interdisciplinary scientific and societal knowledge plays an increasingly important role in global change research. Also, in the field of water resources interdisciplinarity as well as cooperation with stakeholders from outside academia have been recognized as important. In this contribution, we revisit an integrated regional modelling system (DANUBIA), which was developed by an interdisciplinary team of researchers and relied on stakeholder participation in the framework of the GLOWA-Danube project from 2001 to 2011 (Mauser and Prasch 2016). As the model was developed before the current increase in literature on participatory modelling and interdisciplinarity, we ask how a socio-hydrology approach would have helped and in what way it would have made the work different. The present contribution firstly presents the interdisciplinary concept of DANUBIA, mainly with focus on the integration of human behaviour in a spatially explicit, process-based numerical modelling system (Roland Barthel, Janisch, Schwarz, Trifkovic, Nickel, Schulz, and Mauser 2008; R. Barthel, Nickel, Meleg, Trifkovic, and Braun 2005). Secondly, we compare the approaches to interdisciplinarity in GLOWA-Danube with concepts and ideas presented by socio-hydrology. Thirdly, we frame DANUBIA and a review of key literature on socio-hydrology in the context of a survey among hydrologists (N = 184). This discussion is used to highlight gaps and opportunities of the socio-hydrology approach. We show that the interdisciplinary aspect of the project and the participatory process of stakeholder integration in DANUBIA were not entirely successful. However, important insights were gained and important lessons were learnt. Against the background of these experiences we feel that in its current state, socio-hydrology is still lacking a plan for knowledge integration. Moreover, we consider necessary that socio-hydrology takes into account the lessons learnt from these earlier examples of knowledge integration

  7. Uses and limitations of the soil survey in hydrologic modeling

    NASA Astrophysics Data System (ADS)

    Brooks, E.; Boll, J.

    2009-12-01

    One of the greatest challenges in hydrologic modeling is characterizing the effects of soil structure of hydrologic flow paths in complex watersheds. The Predictions in Ungauged Basins (PUB) initiative is pushing scientists to come up with innovative ways to reduce model calibration and predictive uncertainty and improve process understanding. Some of these innovative approaches have included incorporating ‘soft data’ as information for developing conceptual watershed frameworks and guiding calibration. In this study we examine the uses and limitations of the soil survey in hydrologic modeling. County soil surveys were initiated in 1899 and now digital maps are available throughout most of the US. Although these surveys were initially meant to guide selection and development of land, these surveys now include a great wealth of information from specific physical properties to indicators of saturation and development of perched water tables. To what degree does the information in the soil survey improve understanding of dominant hydrologic processes in a watershed? At what point must a hydrologist exercise discretion in using this information? We will discuss the extent to which the soil survey can be used to 1.) conceptualize the basic hydrology of a watershed, 2.) provide input data to a process-based hydrologic model, and 3.) validate spatial predictions of runoff and erosion from distributed hydrologic models. We will demonstrate each of these uses through case studies from multiple ecological regions across the country.

  8. Inactivated ORF virus shows antifibrotic activity and inhibits human hepatitis B virus (HBV) and hepatitis C virus (HCV) replication in preclinical models.

    PubMed

    Paulsen, Daniela; Urban, Andreas; Knorr, Andreas; Hirth-Dietrich, Claudia; Siegling, Angela; Volk, Hans-Dieter; Mercer, Andrew A; Limmer, Andreas; Schumak, Beatrix; Knolle, Percy; Ruebsamen-Schaeff, Helga; Weber, Olaf

    2013-01-01

    Inactivated orf virus (iORFV), strain D1701, is a potent immune modulator in various animal species. We recently demonstrated that iORFV induces strong antiviral activity in animal models of acute and chronic viral infections. In addition, we found D1701-mediated antifibrotic effects in different rat models of liver fibrosis. In the present study, we compare iORFV derived from two different strains of ORFV, D1701 and NZ2, respectively, with respect to their antifibrotic potential as well as their potential to induce an antiviral response controlling infections with the hepatotropic pathogens hepatitis C virus (HCV) and hepatitis B virus (HBV). Both strains of ORFV showed anti-viral activity against HCV in vitro and against HBV in a transgenic mouse model without signs of necro-inflammation in vivo. Our experiments suggest that the absence of liver damage is potentially mediated by iORFV-induced downregulation of antigen cross-presentation in liver sinus endothelial cells. Furthermore, both strains showed significant anti-fibrotic activity in rat models of liver fibrosis. iORFV strain NZ2 appeared more potent compared to strain D1701 with respect to both its antiviral and antifibrotic activity on the basis of dosages estimated by titration of active virus. These results show a potential therapeutic approach against two important human liver pathogens HBV and HCV that independently addresses concomitant liver fibrosis. Further studies are required to characterize the details of the mechanisms involved in this novel therapeutic principle.

  9. Progress Towards Community Modeling in Hydrologic Science (Invited)

    NASA Astrophysics Data System (ADS)

    Famiglietti, J. S.; Murdoch, L. C.; Lakshmi, V.; Hooper, R. P.

    2009-12-01

    In this presentation we review CUAHSI-led activities to advance community modeling in hydrologic science. In particular, these include the Community Hydrologic Modeling Platform (CHyMP) and the HydroHUB. The goal of CHyMP is to significantly advance the development, availability and support of hydrologic models in order to enable transformative science. We make the case that an accelerated, community-wide effort is required in order to address a host of high-priority issues related to hydrology and global change, including food, energy and water security. HydroHUB is website that will improve access to models broadly related to water, including models developed under the CHyMP activity. The status of these activities and results from recent workshops will be discussed, as will near- and long-term plans for the advancing CHyMP and HydroHUB.

  10. 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

  11. Hydrological modelling of urbanized catchments: A review and future directions

    NASA Astrophysics Data System (ADS)

    Salvadore, Elga; Bronders, Jan; Batelaan, Okke

    2015-10-01

    In recent years, the conceptual detail of hydrological models has dramatically increased as a result of improved computational techniques and the availability of spatially-distributed digital data. Nevertheless modelling spatially-distributed hydrological processes can be challenging, particularly in strongly heterogeneous urbanized areas. Multiple interactions occur between urban structures and the water system at various temporal and spatial scales. So far, no universal methodology exists for simulating the urban water system at catchment scale. This paper reviews the state of the art on the scientific knowledge and practice of modelling the urban hydrological system at the catchment scale, with the purpose of identifying current limitations and defining a blueprint for future modelling advances. We compare conceptual descriptions of urban physical hydrological processes on basis of a selection of 43 modelling approaches. The complexity of the urban water system at the catchment scale results in an incomplete understanding of the interaction between urban and natural hydrological systems, and in a high degree of uncertainty. Data availability is still a strong limitation since current modelling practice recognizes the need for high spatial and temporal resolution. Spatio-temporal gaps exist between the physical scales of hydrological processes and the resolution of applied models. Therefore urban hydrology is often simplified either as a study of surface runoff over impervious surfaces or hydraulics of piped systems. Many approaches target very specific objectives and the level of detail in representing physical processes is not consistent. Based on our analysis, we propose a blueprint for a highly complex integrated urban hydrological model. We regard flexibility, in terms of model structure and data assimilation, as the key characteristic for overcoming these limitations. We advocate the use of modular, process-based approaches, which are flexible and adaptable

  12. Improving the representation of hydrologic processes in Earth System Models

    SciTech Connect

    Clark, Martyn P.; Fan, Ying; Lawrence, David M.; Adam, Jennifer C.; Bolster, Diogo; Gochis, David J.; Hooper, Richard P.; Kumar, Mukesh; Leung, L. Ruby; Mackay, D. Scott; Maxwell, Reed M.; Shen, Chaopeng; Swenson, Sean C.; Zeng, Xubin

    2015-08-21

    Many of the scientific and societal challenges in understanding and preparing for global environmental change rest upon our ability to understand and predict the water cycle change at large river basin, continent, and global scales. However, current large-scale models, such as the land components of Earth System Models (ESMs), do not yet represent the terrestrial water cycle in a fully integrated manner or resolve the finer-scale processes that can dominate large-scale water budgets. This paper reviews the current representation of hydrologic processes in ESMs and identifies the key opportunities for improvement. This review suggests that (1) the development of ESMs has not kept pace with modeling advances in hydrology, both through neglecting key processes (e.g., groundwater) and neglecting key aspects of spatial variability and hydrologic connectivity; and (2) many modeling advances in hydrology can readily be incorporated into ESMs and substantially improve predictions of the water cycle. Accelerating modeling advances in ESMs requires comprehensive hydrologic benchmarking activities, in order to systematically evaluate competing modeling alternatives, understand model weaknesses, and prioritize model development needs. This demands stronger collaboration, both through greater engagement of hydrologists in ESM development and through more detailed evaluation of ESM processes in research watersheds. Advances in the representation of hydrologic process in ESMs can substantially improve energy, carbon and nutrient cycle prediction capabilities through the fundamental role the water cycle plays in regulating these cycles.

  13. Modeling the hydrological patterns on Pantanal wetlands, Brazil

    NASA Astrophysics Data System (ADS)

    Castro, A. A.; Cuartas, A.; Coe, M. T.; Koumrouyan, A.; Panday, P. K.; Lefebvre, P.; Padovani, C.; Costa, M. H.; de Oliveira, G. S.

    2014-12-01

    The Pantanal of Brazil is one of the world's largest wetland regions. It is located within the 370,000 km2 Alto Paraguai Basin (BAP). In wet years almost 15% of the total area of the basin can be flooded (approximately 53,000 km2). The hydrological cycle is particularly important in the Pantanal in the transport of materials, and the transfer of energy between atmospheric, aquatic, and terrestrial systems. The INLAND (Integrated Land Surface Model) terrestrial ecosystem model is coupled with the THMB hydrological model to examine the hydrological balance and water dynamics for this region. The INLAND model is based on the IBIS dynamic vegetation model, while THMB represents the river, wetland and lake dynamics of the land surface. The modeled hydrological components are validated with surface and satellite-based estimates of precipitation (gridded observations from CRU v. 3.21, reanalysis data from ERA-interim, and TRMM estimates), evapotranspiration (MODIS and Land Flux-Eval dataset), total runoff (discharge data from ANA-Agência Nacional das Águas - Brazil), and terrestrial water storage (GRACE). Results show that the coupled hydrological model adequately represents the water cycle components, the river discharge and flooded areas. Model simulations are further used to study the influences of climatic variations on the hydrological components, river network, and the inundated areas in the Pantanal.

  14. RHydro - Hydrological models and tools to represent and analyze hydrological data in R

    NASA Astrophysics Data System (ADS)

    Reusser, Dominik; Buytaert, Wouter

    2010-05-01

    In hydrology, basic equations and procedures keep being implemented from scratch by scientist, with the potential for errors and inefficiency. The use of libraries can overcome these problems. Other scientific disciplines such as mathematics and physics have benefited significantly from such an approach with freely available implementations for many routines. As an example, hydrological libraries could contain: Major representations of hydrological processes such as infiltration, sub-surface runoff and routing algorithms. Scaling functions, for instance to combine remote sensing precipitation fields with rain gauge data Data consistency checks Performance measures. Here we present a beginning for such a library implemented in the high level data programming language R. Currently, Top-model, data import routines for WaSiM-ETH as well basic visualization and evaluation tools are implemented. The design is such, that a definition of import scripts for additional models is sufficient to have access to the full set of evaluation and visualization tools.

  15. Comparing complementary NWP model performance for hydrologic forecasting for the river Rhine in an operational setting

    NASA Astrophysics Data System (ADS)

    Davids, Femke; den Toom, Matthijs

    2016-04-01

    This paper investigates the performance of complementary NWP models for hydrologic forecasting for the river Rhine, a large river catchment in Central Europe. An operational forecasting system, RWsOS-Rivieren, produces daily forecasts of discharges and water levels at the Water Management Centre Netherlands. A combination of HBV (rainfall-runoff) and SOBEK (hydrodynamic routing) models is used to produce simulations and forecasts for the catchment. Data assimilation is applied both to the model state of SOBEK and to model outputs. The primary function of the operational forecasting system is to provide reliable and accurate forecasts during periods of high water. The secondary main function is producing daily predictions for water management and water transport in The Netherlands. In addition, predicting water levels during drought periods is becoming increasingly important as well. At this moment several complementary deterministic and ensemble NWP models are used to provide the forecasters with predictions with varied initial conditions, such as ICON, ICON-EU Nest, ECMWF-DET, ECMWF-EPS, HiRLAM, COSMO-LEPS and GLAMEPS. ICON and ICON-EU have recently replaced DWD-GME and DWD COSMO-EU. These models provide weather forecasts with different lengths of lead times and also different periods of operational usage. A direct and quantitative comparison is therefore challenging. Nevertheless, it is important to investigate the suitability of the different NWP models for certain lead times and certain weather situations to help support the hydrological forecasters make an informed forecast during an operational crisis. A hindcast study will investigate the performance of these models in the operational system for different lead times and focusing on periods of both high and low water for Lobith, the location of entry of the river Rhine into The Netherlands.

  16. 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. ...

  17. An open-source distributed mesoscale hydrologic model (mHM)

    NASA Astrophysics Data System (ADS)

    Samaniego, Luis; Kumar, Rohini; Zink, Matthias; Thober, Stephan; Mai, Juliane; Cuntz, Matthias; Schäfer, David; Schrön, Martin; Musuuza, Jude; Prykhodko, Vladyslav; Dalmasso, Giovanni; Attinger, Sabine; Spieler, Diana; Rakovec, Oldrich; Craven, John; Langenberg, Ben

    2014-05-01

    The mesoscale hydrological model (mHM) is based on numerical approximations of dominant hydrological processes that have been tested in various hydrological models such as: HBV and VIC. In general, mHM simulates the following processes: canopy interception, snow accumulation and melting, soil moisture dynamics (n-horizons), infiltration and surface runoff, evapotranspiration, subsurface storage and discharge generation, deep percolation and baseflow, and discharge attenuation and flood routing. The main characteristic of mHM is the treatment of the sub-grid variability of input variables and model parameters which clearly distinguishes this model from existing precipitation-runoff models or land surface models. It uses a Multiscale Parameter Regionalization (MPR) to account for the sub-grid variability and to avoid continuous re-calibration. Effective model parameters are location and time dependent (e.g., soil porosity). They are estimated through upscaling operators that link sub-grid morphologic information (e.g., soil texture) with global transfer-function parameters, which, in turn, are found through multi-basin optimization. Global parameters estimated with the MPR technique are quasi-scale invariant and guarantee flux-matching across scales. mHM is an open source code, written in Fortran 2003 (standard), fully modular, with high computational efficiency, and parallelized. It is portable to multiple platforms (Linux, OS X, Windows) and includes a number of algorithms for sensitivity analysis, analysis of parameter uncertainty (MCMC), and optimization (DDS, SA, SCE). All simulated state variables and outputs can be stored as netCDF files for further analysis and visualization. mHM has been evaluated in all major river basins in Germany and over 80 US and 250 European river basins. The model efficiency (NSE) during validation at proxy locations is on average greater than 0.6. During last years, mHM had been used for number of hydrologic applications such as

  18. Future hydrological extremes: the uncertainty from multiple global climate and global hydrological models

    NASA Astrophysics Data System (ADS)

    Giuntoli, I.; Vidal, J.-P.; Prudhomme, C.; Hannah, D. M.

    2015-05-01

    Projections of changes in the hydrological cycle from global hydrological models (GHMs) driven by global climate models (GCMs) are critical for understanding future occurrence of hydrological extremes. However, uncertainties remain large and need to be better assessed. In particular, recent studies have pointed to a considerable contribution of GHMs that can equal or outweigh the contribution of GCMs to uncertainty in hydrological projections. Using six GHMs and five GCMs from the ISI-MIP multi-model ensemble, this study aims: (i) to assess future changes in the frequency of both high and low flows at the global scale using control and future (RCP8.5) simulations by the 2080s, and (ii) to quantify, for both ends of the runoff spectrum, GCMs and GHMs contributions to uncertainty using a two-way ANOVA. Increases are found in high flows for northern latitudes and in low flows for several hotspots. Globally, the largest source of uncertainty is associated with GCMs, but GHMs are the greatest source in snow-dominated regions. More specifically, results vary depending on the runoff metric, the temporal (annual and seasonal) and regional scale of analysis. For instance, uncertainty contribution from GHMs is higher for low flows than it is for high flows, partly owing to the different processes driving the onset of the two phenomena (e.g. the more direct effect of the GCMs' precipitation variability on high flows). This study provides a comprehensive synthesis of where future hydrological extremes are projected to increase and where the ensemble spread is owed to either GCMs or GHMs. Finally, our results underline the need for improvements in modelling snowmelt and runoff processes to project future hydrological extremes and the importance of using multiple GCMs and GHMs to encompass the uncertainty range provided by these two sources.

  19. 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.

  20. 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.

  1. A question driven socio-hydrological modeling process

    NASA Astrophysics Data System (ADS)

    Garcia, M.; Portney, K.; Islam, S.

    2016-01-01

    Human and hydrological systems are coupled: human activity impacts the hydrological cycle and hydrological conditions can, but do not always, trigger changes in human systems. Traditional modeling approaches with no feedback between hydrological and human systems typically cannot offer insight into how different patterns of natural variability or human-induced changes may propagate through this coupled system. Modeling of coupled human-hydrological systems, also called socio-hydrological systems, recognizes the potential for humans to transform hydrological systems and for hydrological conditions to influence human behavior. However, this coupling introduces new challenges and existing literature does not offer clear guidance regarding model conceptualization. There are no universally accepted laws of human behavior as there are for the physical systems; furthermore, a shared understanding of important processes within the field is often used to develop hydrological models, but there is no such consensus on the relevant processes in socio-hydrological systems. Here we present a question driven process to address these challenges. Such an approach allows modeling structure, scope and detail to remain contingent on and adaptive to the question context. We demonstrate the utility of this process by revisiting a classic question in water resources engineering on reservoir operation rules: what is the impact of reservoir operation policy on the reliability of water supply for a growing city? Our example model couples hydrological and human systems by linking the rate of demand decreases to the past reliability to compare standard operating policy (SOP) with hedging policy (HP). The model shows that reservoir storage acts both as a buffer for variability and as a delay triggering oscillations around a sustainable level of demand. HP reduces the threshold for action thereby decreasing the delay and the oscillation effect. As a result, per capita demand decreases during

  2. Multilayer Control Hierarchy in an Integrated Hydrological Model

    NASA Astrophysics Data System (ADS)

    Park, J.; Obeysekera, J.; Vanzee, R.

    2005-05-01

    Considerable progress has been made in the functionality of integrated hydrological models which can provide evaluation of anthropogenic control and management policies of water resources. Nonetheless, there is still room for improvement in the coupling and expression of water control policies into hydrological models [1]. The Management Simulation Engine (MSE) component of the Regional Simulation Model (RSM) incorporates a multi-level hierarchical control architecture which emphasizes the decoupling of hydrological state information from the management information processing applied to the states. The MSE is intended to allow a flexible, extensible expression of a wide variety anthropogenic water resource control schemes integrated with the hydrological state evaluations of the RSM. Synergy between the multilayer control hierarchy and decoupled hydrologic state and management information facilitates a water resource management feature set not typical of integrated hydrological models. Some of these features include: interoperation and compatibility of diverse management algorithms such as PID, Fuzzy control, LP; and dynamic switching of control processors. This paper describes the MSE control hierarchy with a focus on the aforementioned features and their implementation. [1] Belaineh, G., Peralta, R. C., Hughes, T. C., Simulation/ Optimization Modeling for Water Resources Management, ASCE Journal Water Resources Planning Management, 125(3), p 154-61, 1999

  3. 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.

  4. 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.

  5. Coupling Hydrologic and Hydrodynamic Models to Estimate PMF

    NASA Astrophysics Data System (ADS)

    Felder, G.; Weingartner, R.

    2015-12-01

    Most sophisticated probable maximum flood (PMF) estimations derive the PMF from the probable maximum precipitation (PMP) by applying deterministic hydrologic models calibrated with observed data. This method is based on the assumption that the hydrological system is stationary, meaning that the system behaviour during the calibration period or the calibration event is presumed to be the same as it is during the PMF. However, as soon as a catchment-specific threshold is reached, the system is no longer stationary. At or beyond this threshold, retention areas, new flow paths, and changing runoff processes can strongly affect downstream peak discharge. These effects can be accounted for by coupling hydrologic and hydrodynamic models, a technique that is particularly promising when the expected peak discharge may considerably exceed the observed maximum discharge. In such cases, the coupling of hydrologic and hydraulic models has the potential to significantly increase the physical plausibility of PMF estimations. This procedure ensures both that the estimated extreme peak discharge does not exceed the physical limit based on riverbed capacity and that the dampening effect of inundation processes on peak discharge is considered. Our study discusses the prospect of considering retention effects on PMF estimations by coupling hydrologic and hydrodynamic models. This method is tested by forcing PREVAH, a semi-distributed deterministic hydrological model, with randomly generated, physically plausible extreme precipitation patterns. The resulting hydrographs are then used to externally force the hydraulic model BASEMENT-ETH (riverbed in 1D, potential inundation areas in 2D). Finally, the PMF estimation results obtained using the coupled modelling approach are compared to the results obtained using ordinary hydrologic modelling.

  6. Open source data assimilation framework for hydrological modeling

    NASA Astrophysics Data System (ADS)

    Ridler, Marc; Hummel, Stef; van Velzen, Nils; Katrine Falk, Anne; Madsen, Henrik

    2013-04-01

    An open-source data assimilation framework is proposed for hydrological modeling. Data assimilation (DA) in hydrodynamic and hydrological forecasting systems has great potential to improve predictions and improve model result. The basic principle is to incorporate measurement information into a model with the aim to improve model results by error minimization. Great strides have been made to assimilate traditional in-situ measurements such as discharge, soil moisture, hydraulic head and snowpack into hydrologic models. More recently, remotely sensed data retrievals of soil moisture, snow water equivalent or snow cover area, surface water elevation, terrestrial water storage and land surface temperature have been successfully assimilated in hydrological models. The assimilation algorithms have become increasingly sophisticated to manage measurement and model bias, non-linear systems, data sparsity (time & space) and undetermined system uncertainty. It is therefore useful to use a pre-existing DA toolbox such as OpenDA. OpenDA is an open interface standard for (and free implementation of) a set of tools to quickly implement DA and calibration for arbitrary numerical models. The basic design philosophy of OpenDA is to breakdown DA into a set of building blocks programmed in object oriented languages. To implement DA, a model must interact with OpenDA to create model instances, propagate the model, get/set variables (or parameters) and free the model once DA is completed. An open-source interface for hydrological models exists capable of all these tasks: OpenMI. OpenMI is an open source standard interface already adopted by key hydrological model providers. It defines a universal approach to interact with hydrological models during simulation to exchange data during runtime, thus facilitating the interactions between models and data sources. The interface is flexible enough so that models can interact even if the model is coded in a different language, represent

  7. 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.

  8. Strategies for using remotely sensed data in hydrologic models

    NASA Technical Reports Server (NTRS)

    Peck, E. L.; Keefer, T. N.; Johnson, E. R. (Principal Investigator)

    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.

  9. Effects of uncertainties in hydrological modelling. A case study of a mountainous catchment in Southern Norway

    NASA Astrophysics Data System (ADS)

    Engeland, Kolbjørn; Steinsland, Ingelin; Johansen, Stian Solvang; Petersen-Øverleir, Asgeir; Kolberg, Sjur

    2016-05-01

    In this study, we explore the effect of uncertainty and poor observation quality on hydrological model calibration and predictions. The Osali catchment in Western Norway was selected as case study and an elevation distributed HBV-model was used. We systematically evaluated the effect of accounting for uncertainty in parameters, precipitation input, temperature input and streamflow observations. For precipitation and temperature we accounted for the interpolation uncertainty, and for streamflow we accounted for rating curve uncertainty. Further, the effects of poorer quality of precipitation input and streamflow observations were explored. Less information about precipitation was obtained by excluding the nearest precipitation station from the analysis, while reduced information about the streamflow was obtained by omitting the highest and lowest streamflow observations when estimating the rating curve. The results showed that including uncertainty in the precipitation and temperature inputs has a negligible effect on the posterior distribution of parameters and for the Nash-Sutcliffe (NS) efficiency for the predicted flows, while the reliability and the continuous rank probability score (CRPS) improves. Less information in precipitation input resulted in a shift in the water balance parameter Pcorr, a model producing smoother streamflow predictions, giving poorer NS and CRPS, but higher reliability. The effect of calibrating the hydrological model using streamflow observations based on different rating curves is mainly seen as variability in the water balance parameter Pcorr. When evaluating predictions, the best evaluation scores were not achieved for the rating curve used for calibration, but for rating curves giving smoother streamflow observations. Less information in streamflow influenced the water balance parameter Pcorr, and increased the spread in evaluation scores by giving both better and worse scores.

  10. Evaluation of regional-scale hydrological models using multiple criteria for 12 large river basins on all continents

    NASA Astrophysics Data System (ADS)

    Huang, Shaochun; Krysanova, Valentina; Hattermann, Fred; Vetter, Tobias; Flörke, Martina; Samaniego, Luis; Arheimer, Berit; Yang, Tao; van Griensven, Ann; Su, Buda; Gelfan, Alexander; Breuer, Lutz; Haberlandt, Uwe

    2016-04-01

    A good performance of hydrological impact models under historical climate and land use conditions is a prerequisite for reliable projections under climate change. The evaluation of nine regional-scale hydrological models considering monthly river discharge, long-term average seasonal dynamics and extremes was performed in the framework of the ISI-MIP project for 12 large river basins on all continents. The modelling tools include: ECOMAG, HBV, HYMOD, HYPE, mHM, SWAT, SWIM, VIC and WaterGAP3. These models were evaluated for the following basins: 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, MacKenzie and Upper Amazon in America, and Darling in Australia. The model calibration and validation was done using WATCH climate data for all cases. The model outputs were evaluated using twelve statistical criteria to assess the fidelity of model simulations for monthly discharge, seasonal dynamics, flow duration curves, extreme floods and low flow. The reproduction of monthly discharge and seasonal dynamics was successful in all basins except the Darling, and the high flows and flood characteristics were also captured satisfactory in most cases. However, the criteria for low flow were below the thresholds in many cases. An overview of this collaborative experiment and main results on model evaluation will be presented.

  11. Spatial Resolution and Catchment Size Interaction of Soil Hydrological Properties for Hydrological Modeling

    NASA Astrophysics Data System (ADS)

    Libohova, Zamir; Bowling, Laura C.; Owens, Phillip R.; Schoeneberger, Philip; Wysocki, Douglas; Wills, Skye; Lindbo, David

    2016-04-01

    Spatial resolution of soil hydrologic properties is critical for distributed hydrological model streamflow simulations. Soils from US Soil Survey Geographic (SSURGO) Database are mapped at scales varying from 1:12,000 to 65,000. Related to these scales are also soil hydrological properties, which could vary spatially outside of the common SSURGO scale range. The objective of this research was to assess the role of the spatial resolution of soil depth on simulated hydrological response for various watershed sizes using the Distributed Hydrology Soil Vegetation Model (DHSVM). The study site was Hall Creek watershed a 56 km2 in size located in Dubois County in southern Indiana, USA. The watershed size was divided in 55 sub-watersheds varying in size from less than 5 km2 to 56 km2. The grid size spatial resolution of soil hydrological properties varied from 10x10, 30x30 and 90x90m. The simulated streamflow metrics were annual mean, minimum and maximum streamflow, and R-B Flashiness, which measures the variability in streamflow between successive days highlighting the fluctuation of discharge relative to total discharge. The slopes of the regression of simulated stream discharge parameters versus watershed size were used to assess the presence of interaction. In addition, the coefficient of variation was used to assess the variability for the R-B index, annual mean, annual minimum and maximum stream discharge across different model resolutions within each watershed category. The slope for 10x10 and 30x30m spatial resolution for annual mean, and minimum streamflow were not significantly different from zero across all watershed sizes indicating lack of interaction. However, slope for the R-B flashiness was significantly different from zero for the 90x90 m grid size indicating that watershed size change is sensitive at this spatial resolution. The variability of R-B index, annual mean and annual minimum hydrologic metrics decreased with increasing watershed size but

  12. Models of atmosphere-ecosystem-hydrology interactions: Approaches and testing

    NASA Technical Reports Server (NTRS)

    Schimel, David S.

    1992-01-01

    Interactions among the atmosphere, terrestrial ecosystems, and the hydrological cycle have been the subject of investigation for many years, although most of the research has had a regional focus. The topic is broad, including the effects of climate and hydrology on vegetation, the effects of vegetation on hydrology, the effects of the hydrological cycle on the atmosphere, and interactions of the cycles via material flux such as solutes and trace gases. The intent of this paper is to identify areas of critical uncertainty, discuss modeling approaches to resolving those problems, and then propose techniques for testing. I consider several interactions specifically to illustrate the range of problems. These areas are as follows: (1) cloud parameterizations and the land surface, (2) soil moisture, and (3) the terrestrial carbon cycle.

  13. Advancing Collaboration through Hydrologic Data and Model Sharing

    NASA Astrophysics Data System (ADS)

    Tarboton, D. G.; Idaszak, R.; Horsburgh, J. S.; Ames, D. P.; Goodall, J. L.; Band, L. E.; Merwade, V.; Couch, A.; Hooper, R. P.; Maidment, D. R.; Dash, P. K.; Stealey, M.; Yi, H.; Gan, T.; Castronova, A. M.; Miles, B.; Li, Z.; Morsy, M. M.

    2015-12-01

    HydroShare is an online, collaborative system for open sharing of hydrologic data, analytical tools, and models. It supports the sharing of and collaboration around "resources" which are defined primarily by standardized metadata, content data models for each resource type, and an overarching resource data model based on the Open Archives Initiative's Object Reuse and Exchange (OAI-ORE) standard and a hierarchical file packaging system called "BagIt". HydroShare expands the data sharing capability of the CUAHSI Hydrologic Information System by broadening the classes of data accommodated to include geospatial and multidimensional space-time datasets commonly used in hydrology. HydroShare also includes new capability for sharing models, model components, and analytical tools and will take advantage of emerging social media functionality to enhance information about and collaboration around hydrologic data and models. It also supports web services and server/cloud based computation operating on resources for the execution of hydrologic models and analysis and visualization of hydrologic data. HydroShare uses iRODS as a network file system for underlying storage of datasets and models. Collaboration is enabled by casting datasets and models as "social objects". Social functions include both private and public sharing, formation of collaborative groups of users, and value-added annotation of shared datasets and models. The HydroShare web interface and social media functions were developed using the Django web application framework coupled to iRODS. Data visualization and analysis is supported through the Tethys Platform web GIS software stack. Links to external systems are supported by RESTful web service interfaces to HydroShare's content. This presentation will introduce the HydroShare functionality developed to date and describe ongoing development of functionality to support collaboration and integration of data and models.

  14. Impact of improved snowmelt modelling in a monthly hydrological model.

    NASA Astrophysics Data System (ADS)

    Folton, Nathalie; Garcia, Florine

    2016-04-01

    The quantification and the management of water resources at the regional scale require hydrological models that are both easy to implement and efficient. To be reliable and robust, these models must be calibrated and validated on a large number of catchments that are representative of various hydro-meteorological conditions, physiographic contexts, and specific hydrological behavior (e.g. mountainous catchments). The GRLoiEau monthly model, with its simple structure and its two free parameters, answer our need of such a simple model. It required the development of a snow routine to model catchments with temporarily snow-covered areas. The snow routine developed here does not claim to represent physical snowmelt processes but rather to simulate them globally on the catchment. The snowmelt equation is based on the degree-day method which is widely used by the hydrological community, in particular in engineering studies (Etchevers 2000). A potential snowmelt (Schaefli et al. 2005) was computed, and the parameters of the snow routine were regionalized for each mountain area. The GRLoiEau parsimonious structure requires meteorological data. They come from the distributed mesoscale atmospheric analysis system SAFRAN, which provides estimations of daily solid and liquid precipitations and temperatures on a regular square grid at the spatial resolution of 8*8 km², throughout France. Potential evapotranspiration was estimated using the formula by Oudin et al. (2005). The aim of this study is to improve the quality of monthly simulations for ungauged basins, in particular for all types of mountain catchments, without increasing the number of free parameters of the model. By using daily SAFRAN data, the production store and snowmelt can be run at a daily time scale. The question then arises whether simulating the monthly flows using a production function at a finer time step would improve the results. And by using the SAFRAN distributed climate series, a distributed approach

  15. Models for hydrologic design of evapotranspiration landfill covers.

    PubMed

    Hauser, Victor L; Gimon, Dianna M; Bonta, James V; Howell, Terry A; Malone, Robert W; Williams, Jimmy R

    2005-09-15

    The technology used in landfill covers is changing, and an alternative cover called the evapotranspiration (ET) landfill cover is coming into use. Important design requirements are prescribed by Federal rules and regulations for conventional landfill covers but not for ET landfill covers. There is no accepted hydrologic model for ET landfill cover design. This paper describes ET cover requirements and design issues, and assesses the accuracy of the EPIC and HELP hydrologic models when used for hydrologic design of ET covers. We tested the models against high-quality field measurements available from lysimeters maintained by the Agricultural Research Service of the U.S. Department of Agriculture at Coshocton, Ohio, and Bushland, Texas. The HELP model produced substantial errors in estimating hydrologic variables. The EPIC model estimated ET and deep percolation with errors less than 7% and 5%, respectively, and accurately matched extreme events with an error of less than 2% of precipitation. The EPIC model is suitable for use in hydrologic design of ET landfill covers.

  16. HBV and liver cancer.

    PubMed

    Leung, Nancy

    2005-07-01

    The association of hepatitis B virus (HBV) infection and liver cancer is well documented in epidemiological study. Patients with chronic hepatitis B have increased risk of hepatocelluar carcinoma (HCC), in particular those with active liver disease and cirrhosis. The incidence of HCC increases with age and is more common among male patients. The introduction of universal HBV vaccination program for the newborn in endemic regions has started to show beneficial impact. Taiwan introduced this program two decades ago and the incidence of liver cancer among infants and young children have declined significantly. The carcinogenic events leading to HCC are under intense research. A number of hypotheses have been proposed. HBV is not directly hepatotoxic but its interaction with the host immune system creates opportunity for HBV DNA integration into the host genome. One of the main foci of research is the HBX-encoded X protein. Its integration and protein expression impose alteration in cell proliferation cycle and apoptosis process. Many other factors may be involved including viral-induced alterations in p53 and telemerase, HBV genotypes, co-infection with HCV or delta agents, patient's lifestyle such as smoking, alcohol excesses, and genetic factors of the host patient. The processes of necroinflammation, cell proliferation and fibrosis facilitate the initial carcinogenic development. HCC surveillance with tumor markers such as alpha-foetal protein, decarboxylated prothrombin, in conjunction with imaging techniques has identified early small HCC that is amenable to curative therapy. Viral load has been correlated with increase risk of HCC. The available anti-viral agents have demonstrated clinical benefit among those with maintained and sustained response. Interferon and lamivudine therapy have demonstrated reduction of HCC among responders. However, they only constitute a minority proportion of treated patients. The mainstay of prevention should lie in prevention of

  17. Hydrological model uncertainty due to spatial evapotranspiration estimation methods

    NASA Astrophysics Data System (ADS)

    Yu, Xuan; Lamačová, Anna; Duffy, Christopher; Krám, Pavel; Hruška, Jakub

    2016-05-01

    Evapotranspiration (ET) continues to be a difficult process to estimate in seasonal and long-term water balances in catchment models. Approaches to estimate ET typically use vegetation parameters (e.g., leaf area index [LAI], interception capacity) obtained from field observation, remote sensing data, national or global land cover products, and/or simulated by ecosystem models. In this study we attempt to quantify the uncertainty that spatial evapotranspiration estimation introduces into hydrological simulations when the age of the forest is not precisely known. The Penn State Integrated Hydrologic Model (PIHM) was implemented for the Lysina headwater catchment, located 50°03‧N, 12°40‧E in the western part of the Czech Republic. The spatial forest patterns were digitized from forest age maps made available by the Czech Forest Administration. Two ET methods were implemented in the catchment model: the Biome-BGC forest growth sub-model (1-way coupled to PIHM) and with the fixed-seasonal LAI method. From these two approaches simulation scenarios were developed. We combined the estimated spatial forest age maps and two ET estimation methods to drive PIHM. A set of spatial hydrologic regime and streamflow regime indices were calculated from the modeling results for each method. Intercomparison of the hydrological responses to the spatial vegetation patterns suggested considerable variation in soil moisture and recharge and a small uncertainty in the groundwater table elevation and streamflow. The hydrologic modeling with ET estimated by Biome-BGC generated less uncertainty due to the plant physiology-based method. The implication of this research is that overall hydrologic variability induced by uncertain management practices was reduced by implementing vegetation models in the catchment models.

  18. Modelling hydrological effects of wetland restoration: a differentiated view.

    PubMed

    Staes, J; Rubarenzya, M H; Meire, P; Willems, P

    2009-01-01

    The paper presents findings of a conjunctive hydrological and ecological study into habitat restoration and catchment hydrology. Physically-based, fully distributed hydrological modelling was coupled with spatial analysis and wetland scenario generation techniques to simulate potential effects of restoring lower, middle, and upper catchment wetlands. In the past, anthropogenic interference of this catchments' landscape for agriculture and settlement has left most wetland areas drained, and brought the natural functioning of the ecosystem into conflict with human needs. Many eco-hydrology studies conclude that such disturbances result in a more extreme hydrological regime. The study objectives were to develop and study innovative methods for habitat restoration, and understand the potential hydrological impacts of each approach. The study aims to analyze the scenarios and whether the hydrological response is influenced by the topological placement of the restoration sites. Land-use change scenarios are developed on the basis of physical characteristics and consider the credibility of transitions from current land-use. This study focused on the position of the wetlands in the catchment and hydrological typology. Wetland restoration scenarios are created for different geographical settings within the catchment. A distinction is made between groundwater dependent wetlands and wetlands that are influenced by in-stream water tables or surface water inundations. Results show that there is little effect on the total annual water budget. The results point to river valley rewetting as having the effect of decreasing the paved overland component of stream flow, and increasing the saturated zone flow component. It promoted groundwater recharge. There was no increase of peak flows due to headwater wetlands, contrary to some sources (Bullock & Acreman 2003). The catchments' actual evapotranspiration and root zone water responses were found to be varied over the analysis points

  19. 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

  20. Understanding uncertainty in process-based hydrological models

    NASA Astrophysics Data System (ADS)

    Clark, M. P.; Kavetski, D.; Slater, A. G.; Newman, A. J.; Marks, D. G.; Landry, C.; Lundquist, J. D.; Rupp, D. E.; Nijssen, B.

    2013-12-01

    Building an environmental model requires making a series of decisions regarding the appropriate representation of natural processes. While some of these decisions can already be based on well-established physical understanding, gaps in our current understanding of environmental dynamics, combined with incomplete knowledge of properties and boundary conditions of most environmental systems, make many important modeling decisions far more ambiguous. There is consequently little agreement regarding what a 'correct' model structure is, especially at relatively larger spatial scales such as catchments and beyond. In current practice, faced with such a range of decisions, different modelers will generally make different modeling decisions, often on an ad hoc basis, based on their balancing of process understanding, the data available to evaluate the model, the purpose of the modeling exercise, and their familiarity with or investment in an existing model infrastructure. This presentation describes development and application of multiple-hypothesis models to evaluate process-based hydrologic models. Our numerical model uses robust solutions of the hydrology and thermodynamic governing equations as the structural core, and incorporates multiple options to represent the impact of different modeling decisions, including multiple options for model parameterizations (e.g., below-canopy wind speed, thermal conductivity, storage and transmission of liquid water through soil, etc.), as well as multiple options for model architecture, that is, the coupling and organization of different model components (e.g., representations of sub-grid variability and hydrologic connectivity, coupling with groundwater, etc.). Application of this modeling framework across a collection of different research basins demonstrates that differences among model parameterizations are often overwhelmed by differences among equally-plausible model parameter sets, while differences in model architecture lead

  1. 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...

  2. Evaluation of Global Hydrological Model considering Reservoir Operation

    NASA Astrophysics Data System (ADS)

    Masaki, Y.; Hanasaki, N.; Takahashi, K.; Hijioka, Y.

    2015-12-01

    Construction of reservoirs, especially in the last half of the 20th century, has greatly contributed to the prevention of riverine disasters and the security of water supplies in the world. Since reservoirs markedly alter the river flow in downstream, precise modeling of reservoir operation is necessary for the improvement of river flow simulations. Yet global hydrological simulations considering reservoir operation are still immature - although actual reservoirs are practically operated by considering both meteorological conditions and regional requests within each river basin, modeled reservoirs are operated according to simplified operation schemes optimized for global applicability with less regional variety. Thus, checking the performance of global hydrological models based on the comparison of model outputs with historical observation records is important for better understanding of uncertainties in the hydrological simulation. In this study, we conducted long-term historical hydrological simulations considering 6862 reservoirs worldwide. Simulation settings were based on the protocol of the model intercomparison project, termed ISI-MIP2.1A. We compared time-series of observed and simulated reservoir storage to examine the performance of reservoir operation schemes adopted in the H08 global hydrological model for 29 reservoirs, most of which are located in the United States and Canada, selected by considering data availability on the reservoir operation. We ran the hydrological model under four different meteorological forcing data sets distributed for ISI-MIP2.1A simulations for a historical period. By examining whether the observed water storage lies within the spread of simulated water storage with the four sets of meteorological forcing, we identified a prevailing source of errors in the simulation of the river discharge - reservoir operation schemes or meteorological forcing data.

  3. Hydrologic and water quality terminology 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...

  4. The Use of Simulation Models in Teaching Geomorphology and Hydrology.

    ERIC Educational Resources Information Center

    Kirkby, Mike; Naden, Pam

    1988-01-01

    Learning about the physical environment from computer simulation models is discussed in terms of three stages: exploration, experimentation, and calibration. Discusses the effective use of models and presents two computer simulations written in BBC BASIC, STORFLO (for catchment hydrology) and SLOPEK (for hillslope evolution). (Author/GEA)

  5. Performance measures and criteria for hydrologic and water quality models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Performance measures and criteria are essential for model calibration and validation. This presentation will include a summary of one of the papers that will be included in the 2014 Hydrologic and Water Quality Model Calibration & Validation Guidelines Special Collection of the ASABE Transactions. T...

  6. 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 ...

  7. A physically-based Distributed Hydrologic Model for Tropical Catchments

    NASA Astrophysics Data System (ADS)

    Abebe, N. A.; Ogden, F. L.

    2010-12-01

    Hydrological models are mathematical formulations intended to represent observed hydrological processes in a watershed. Simulated watersheds in turn vary in their nature based on their geographic location, altitude, climatic variables and geology and soil formation. Due to these variations, available hydrologic models vary in process formulation, spatial and temporal resolution and data demand. Many tropical watersheds are characterized by extensive and persistent biological activity and a large amount of rain. The Agua Salud catchments located within the Panama Canal Watershed, Panama, are such catchments identified by steep rolling topography, deep soils derived from weathered bedrock, and limited exposed bedrock. Tropical soils are highly affected by soil cracks, decayed tree roots and earthworm burrows forming a network of preferential flow paths that drain to a perched water table, which forms at a depth where the vertical hydraulic conductivity is significantly reduced near the bottom of the bioturbation layer. We have developed a physics-based, spatially distributed, multi-layered hydrologic model to simulate the dominant processes in these tropical watersheds. The model incorporates the major flow processes including overland flow, channel flow, matrix and non-Richards film flow infiltration, lateral downslope saturated matrix and non-Darcian pipe flow in the bioturbation layer, and deep saturated groundwater flow. Emphasis is given to the modeling of subsurface unsaturated zone soil moisture dynamics and the saturated preferential lateral flow from the network of macrospores. Preliminary results indicate that the model has the capability to simulate the complex hydrological processes in the catchment and will be a useful tool in the ongoing comprehensive ecohydrological studies in tropical catchments, and help improve our understanding of the hydrological effects of deforestation and aforestation.

  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. Hydrologic Modeling in a Service-Oriented Architecture

    NASA Astrophysics Data System (ADS)

    Goodall, J. L.

    2008-12-01

    Service Oriented Architectures (SOA) offer an approach for creating hydrologic models whereby a model is decomposed into independent computational services that are geographically distributed yet accessible through the Internet. The advantage of this modeling approach is that diverse groups can contribute computational routines that are usable by a wide community, and these routines can be used across operating systems and languages with minimal requirements on the client computer. While the approach has clear benefits in building next generation hydrologic models, a number of challenges must be addressed in order for the approach to reach its full potential. One such challenge in achieving service-oriented hydrologic modeling is establishing standards for web service interfaces and for service-to-service data exchanges. This study presents a prototype service-oriented modeling system that leverages existing protocols and standards (OpenMI, WaterML, GML, etc.) to perform service-oriented hydrologic modeling. The goal of the research is to access the completeness of these existing protocols and standards in achieving the goal, and to highlight shortcomings that should be addressed through future research and development efforts.

  10. Integrating Geophysics, Geology, and Hydrology for Enhanced Hydrogeological Modeling

    NASA Astrophysics Data System (ADS)

    Auken, E.

    2012-12-01

    Geophysical measurements are important for providing information on the geological structure to hydrological models. Regional scale surveys, where several watersheds are mapped at the same time using helicopter borne transient electromagnetic, results in a geophysical model with a very high lateral and vertical resolution of the geological layers. However, there is a bottleneck when it comes to integrating the information from the geophysical models into the hydrological model. This transformation is difficult, because there is not a simple relationship between the hydraulic conductivity needed for the hydrological model and the electrical conductivity measured by the geophysics. In 2012 the Danish Council for Strategic Research has funded a large research project focusing on the problem of integrating geophysical models into hydrological models. The project involves a number of Danish research institutions, consulting companies, a water supply company, as well as foreign partners, USGS (USA), TNO (Holland) and CSIRO (Australia). In the project we will: 1. Use statistical methods to describe the spatial correlation between the geophysical and the lithological/hydrological data; 2. Develop semi-automatic or automatic methods for transforming spatially sampled geophysical data into geological- and/or groundwater-model parameter fields; 3. Develop an inversion method for large-scale geophysical surveys in which the model space is concordant with the hydrological model space 4. Demonstrate the benefits of spatially distributed geophysical data for informing and updating groundwater models and increasing the predictive power of management scenarios. 5. Develop a new receiver system for Magnetic Resonance Sounding data and further enhance the resolution capability of data from the SkyTEM system. 6. In test areas in Denmark, Holland, USA and Australia we will use data from existing airborne geophysical data, hydrological and geological data and also collect new airborne

  11. Impact of a statistical bias correction on the projected simulated hydrological changes obtained from three GCMs and two hydrology models

    NASA Astrophysics Data System (ADS)

    Hagemann, Stefan; Chen, Cui; Haerter, Jan O.; Gerten, Dieter; Heinke, Jens; Piani, Claudio

    2010-05-01

    Future climate model scenarios depend crucially on their adequate representation of the hydrological cycle. Within the European project "Water and Global Change" (WATCH) special care is taken to couple state-of-the-art climate model output to a suite of hydrological models. This coupling is expected to lead to a better assessment of changes in the hydrological cycle. However, due to the systematic model errors of climate models, their output is often not directly applicable as input for hydrological models. Thus, the methodology of a statistical bias correction has been developed, which can be used for correcting climate model output to produce internally consistent fields that have the same statistical intensity distribution as the observations. As observations, global re-analysed daily data of precipitation and temperature are used that are obtained in the WATCH project. We will apply the bias correction to global climate model data of precipitation and temperature from the GCMs ECHAM5/MPIOM, CNRM-CM3 and LMDZ-4, and intercompare the bias corrected data to the original GCM data and the observations. Then, the orginal and the bias corrected GCM data will be used to force two global hydrology models: (1) the hydrological model of the Max Planck Institute for Meteorology (MPI-HM) consisting of the Simplified Land surface (SL) scheme and the Hydrological Discharge (HD) model, and (2) the dynamic vegetation model LPJmL operated by the Potsdam Institute for Climate Impact Research. The impact of the bias correction on the projected simulated hydrological changes will be analysed, and the resulting behaviour of the two hydrology models will be compared.

  12. [A new precipitation distribution hydrological model and its application].

    PubMed

    Zhang, Shengtang; Kang, Shaozhong; Liu, Yin

    2005-03-01

    In distribution hydrological models, precipitation is the key input data for analyzing and computing hydrological processes. Finding a way to produce distribution precipitation data is a hotspot in hydrological research. This paper presented the hypothesis that the distribution of precipitation on the earth surface is the result of the effects of atmosphere system and terrain. Moreover, the spatial distribution of natural precipitation is a group of concentric ovals on the flat earth surface, and has a definite centre with maximum precipitation not affected by terrain. Supporting by the hypothesis, this paper established a new precipitation distribution hydrological model which could simulate the spatial distribution of precipitation, and modified the terrain effect on precipitation through Newton interpolation. The position of the precipitation centre and its precipitation amount were simulated in first time, and thus, the model could have a practical value in basin storm analysis and real-time runoff forecasting. The model was tested by the precipitation data of the Xichuan river basin in the Loess Plateau, which indicated that the model had a high precision.

  13. A surface hydrology model for regional vector borne disease models

    NASA Astrophysics Data System (ADS)

    Tompkins, Adrian; Asare, Ernest; Bomblies, Arne; Amekudzi, Leonard

    2016-04-01

    Small, sun-lit temporary pools that form during the rainy season are important breeding sites for many key mosquito vectors responsible for the transmission of malaria and other diseases. The representation of this surface hydrology in mathematical disease models is challenging, due to their small-scale, dependence on the terrain and the difficulty of setting soil parameters. Here we introduce a model that represents the temporal evolution of the aggregate statistics of breeding sites in a single pond fractional coverage parameter. The model is based on a simple, geometrical assumption concerning the terrain, and accounts for the processes of surface runoff, pond overflow, infiltration and evaporation. Soil moisture, soil properties and large-scale terrain slope are accounted for using a calibration parameter that sets the equivalent catchment fraction. The model is calibrated and then evaluated using in situ pond measurements in Ghana and ultra-high (10m) resolution explicit simulations for a village in Niger. Despite the model's simplicity, it is shown to reproduce the variability and mean of the pond aggregate water coverage well for both locations and validation techniques. Example malaria simulations for Uganda will be shown using this new scheme with a generic calibration setting, evaluated using district malaria case data. Possible methods for implementing regional calibration will be briefly discussed.

  14. Legacy model integration for enhancing hydrologic interdisciplinary research

    NASA Astrophysics Data System (ADS)

    Dozier, A.; Arabi, M.; David, O.

    2013-12-01

    Many challenges are introduced to interdisciplinary research in and around the hydrologic science community due to advances in computing technology and modeling capabilities in different programming languages, across different platforms and frameworks by researchers in a variety of fields with a variety of experience in computer programming. Many new hydrologic models as well as optimization, parameter estimation, and uncertainty characterization techniques are developed in scripting languages such as Matlab, R, Python, or in newer languages such as Java and the .Net languages, whereas many legacy models have been written in FORTRAN and C, which complicates inter-model communication for two-way feedbacks. However, most hydrologic researchers and industry personnel have little knowledge of the computing technologies that are available to address the model integration process. Therefore, the goal of this study is to address these new challenges by utilizing a novel approach based on a publish-subscribe-type system to enhance modeling capabilities of legacy socio-economic, hydrologic, and ecologic software. Enhancements include massive parallelization of executions and access to legacy model variables at any point during the simulation process by another program without having to compile all the models together into an inseparable 'super-model'. Thus, this study provides two-way feedback mechanisms between multiple different process models that can be written in various programming languages and can run on different machines and operating systems. Additionally, a level of abstraction is given to the model integration process that allows researchers and other technical personnel to perform more detailed and interactive modeling, visualization, optimization, calibration, and uncertainty analysis without requiring deep understanding of inter-process communication. To be compatible, a program must be written in a programming language with bindings to a common

  15. Reducing equifinality of hydrological models by integrating Functional Streamflow Disaggregation

    NASA Astrophysics Data System (ADS)

    Lüdtke, Stefan; Apel, Heiko; Nied, Manuela; Carl, Peter; Merz, Bruno

    2014-05-01

    A universal problem of the calibration of hydrological models is the equifinality of different parameter sets derived from the calibration of models against total runoff values. This is an intrinsic problem stemming from the quality of the calibration data and the simplified process representation by the model. However, discharge data contains additional information which can be extracted by signal processing methods. An analysis specifically developed for the disaggregation of runoff time series into flow components is the Functional Streamflow Disaggregation (FSD; Carl & Behrendt, 2008). This method is used in the calibration of an implementation of the hydrological model SWIM in a medium sized watershed in Thailand. FSD is applied to disaggregate the discharge time series into three flow components which are interpreted as base flow, inter-flow and surface runoff. In addition to total runoff, the model is calibrated against these three components in a modified GLUE analysis, with the aim to identify structural model deficiencies, assess the internal process representation and to tackle equifinality. We developed a model dependent (MDA) approach calibrating the model runoff components against the FSD components, and a model independent (MIA) approach comparing the FSD of the model results and the FSD of calibration data. The results indicate, that the decomposition provides valuable information for the calibration. Particularly MDA highlights and discards a number of standard GLUE behavioural models underestimating the contribution of soil water to river discharge. Both, MDA and MIA yield to a reduction of the parameter ranges by a factor up to 3 in comparison to standard GLUE. Based on these results, we conclude that the developed calibration approach is able to reduce the equifinality of hydrological model parameterizations. The effect on the uncertainty of the model predictions is strongest by applying MDA and shows only minor reductions for MIA. Besides

  16. Modeller subjectivity and calibration impacts on hydrological model applications: an event-based comparison for a road-adjacent catchment in south-east Norway.

    PubMed

    Kalantari, Zahra; Lyon, Steve W; Jansson, Per-Erik; Stolte, Jannes; French, Helen K; Folkeson, Lennart; Sassner, Mona

    2015-01-01

    Identifying a 'best' performing hydrologic model in a practical sense is difficult due to the potential influences of modeller subjectivity on, for example, calibration procedure and parameter selection. This is especially true for model applications at the event scale where the prevailing catchment conditions can have a strong impact on apparent model performance and suitability. In this study, two lumped models (CoupModel and HBV) and two physically-based distributed models (LISEM and MIKE SHE) were applied to a small catchment upstream of a road in south-eastern Norway. All models were calibrated to a single event representing typical winter conditions in the region and then applied to various other winter events to investigate the potential impact of calibration period and methodology on model performance. Peak flow and event-based hydrographs were simulated differently by all models leading to differences in apparent model performance under this application. In this case-study, the lumped models appeared to be better suited for hydrological events that differed from the calibration event (i.e., events when runoff was generated from rain on non-frozen soils rather than from rain and snowmelt on frozen soil) while the more physical-based approaches appeared better suited during snowmelt and frozen soil conditions more consistent with the event-specific calibration. This was due to the combination of variations in subsurface conditions over the eight events considered, the subsequent ability of the models to represent the impact of the conditions (particularly when subsurface conditions varied greatly from the calibration event), and the different approaches adopted to calibrate the models. These results indicate that hydrologic models may not only need to be selected on a case-by-case basis but also have their performance evaluated on an application-by-application basis since how a model is applied can be equally important as inherent model structure.

  17. Impact of multicollinearity on small sample hydrologic regression models

    NASA Astrophysics Data System (ADS)

    Kroll, Charles N.; Song, Peter

    2013-06-01

    Often hydrologic regression models are developed with ordinary least squares (OLS) procedures. The use of OLS with highly correlated explanatory variables produces multicollinearity, which creates highly sensitive parameter estimators with inflated variances and improper model selection. It is not clear how to best address multicollinearity in hydrologic regression models. Here a Monte Carlo simulation is developed to compare four techniques to address multicollinearity: OLS, OLS with variance inflation factor screening (VIF), principal component regression (PCR), and partial least squares regression (PLS). The performance of these four techniques was observed for varying sample sizes, correlation coefficients between the explanatory variables, and model error variances consistent with hydrologic regional regression models. The negative effects of multicollinearity are magnified at smaller sample sizes, higher correlations between the variables, and larger model error variances (smaller R2). The Monte Carlo simulation indicates that if the true model is known, multicollinearity is present, and the estimation and statistical testing of regression parameters are of interest, then PCR or PLS should be employed. If the model is unknown, or if the interest is solely on model predictions, is it recommended that OLS be employed since using more complicated techniques did not produce any improvement in model performance. A leave-one-out cross-validation case study was also performed using low-streamflow data sets from the eastern United States. Results indicate that OLS with stepwise selection generally produces models across study regions with varying levels of multicollinearity that are as good as biased regression techniques such as PCR and PLS.

  18. Progress and Prospects of Anti-HBV Gene Therapy Development.

    PubMed

    Maepa, Mohube B; Roelofse, Ilke; Ely, Abdullah; Arbuthnot, Patrick

    2015-07-31

    Despite the availability of an effective vaccine against hepatitis B virus (HBV), chronic infection with the virus remains a major global health concern. Current drugs against HBV infection are limited by emergence of resistance and rarely achieve complete viral clearance. This has prompted vigorous research on developing better drugs against chronic HBV infection. Advances in understanding the life cycle of HBV and improvements in gene-disabling technologies have been impressive. This has led to development of better HBV infection models and discovery of new drug candidates. Ideally, a regimen against chronic HBV infection should completely eliminate all viral replicative intermediates, especially covalently closed circular DNA (cccDNA). For the past few decades, nucleic acid-based therapy has emerged as an attractive alternative that may result in complete clearance of HBV in infected patients. Several genetic anti-HBV strategies have been developed. The most studied approaches include the use of antisense oligonucleotides, ribozymes, RNA interference effectors and gene editing tools. This review will summarize recent developments and progress made in the use of gene therapy against HBV.

  19. Hydrologic and water quality models: Use, calibration, and validation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper introduces a special collection of 22 research articles that present and discuss calibration and validation concepts in detail for hydrologic and water quality models by their developers and presents a broad framework for developing the American Society of Agricultural and Biological Engi...

  20. 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

  1. 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.

  2. 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...

  3. Evaluating hydrological model performance using information theory-based metrics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The accuracy-based model performance metrics not necessarily reflect the qualitative correspondence between simulated and measured streamflow time series. The objective of this work was to use the information theory-based metrics to see whether they can be used as complementary tool for hydrologic m...

  4. Modeling the Hydrologic Processes of a Permeable Pavement System

    EPA Science Inventory

    A permeable pavement system can capture stormwater to reduce runoff volume and flow rate, improve onsite groundwater recharge, and enhance pollutant controls within the site. A new unit process model for evaluating the hydrologic performance of a permeable pavement system has be...

  5. Hydrological modeling using a multi-site stochastic weather generator

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weather data is usually required at several locations over a large watershed, especially when using distributed models for hydrological simulations. In many applications, spatially correlated weather data can be provided by a multi-site stochastic weather generator which considers the spatial correl...

  6. 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

  7. 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.

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

    NASA Astrophysics Data System (ADS)

    Sennikovs, J.; Timuhins, A.

    2009-04-01

    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. We considered set of 21 RCM model output data from the PRUDENCE project. They were statisically tested against temperature and precipitation observations for the reference period (1961-1990). The best performing RCM was selected according to penalty function constructed based on monthly average temperature, precipitation and montly standard deviation of temperature and precipitation. The calibrated hydrological model was employed for the run-off calculations of climatic reference period (1961-1990). The first step of the study was to statistically compare (1) observed discharge, (2) modelled discharge using observed temperature and precipitation as the forcing, (3) modelled discharge using the temperature and precipitation time series from the best RCM as the forcing. The monthly average observed discharge agrees well with the modelled discharge in case of usage of the observed forcing. The agreement of observed discharge with modelled discharge using RCM data is rather disappointing, especially during winter and spring snow melt flood periods. Usage of the meteorological forcing from the RCM's reference period overestimates yearly average discharge by approximately 70%. The second step of our study was to modify and use the modified RCM data as an input for hydrological modelling. The modification method relies on equalizing of temperature and precipitation histograms between observed and RCM data for each day of the year and each observation location. We show that monthly average discharges agree quite well with observed in the case of use of modified RCM data as a

  9. A visual interface for the SUPERFLEX hydrological modelling framework

    NASA Astrophysics Data System (ADS)

    Gao, H.; Fenicia, F.; Kavetski, D.; Savenije, H. H. G.

    2012-04-01

    The SUPERFLEX framework is a modular modelling system for conceptual hydrological modelling at the catchment scale. This work reports the development of a visual interface for the SUPERFLEX model. This aims to enhance the communication between the hydrologic experimentalists and modelers, in particular further bridging the gap between the field soft data and the modeler's knowledge. In collaboration with field experimentalists, modelers can visually and intuitively hypothesize different model architectures and combinations of reservoirs, select from a library of constructive functions to describe the relationship between reservoirs' storage and discharge, specify the shape of lag functions and, finally, set parameter values. The software helps hydrologists take advantage of any existing insights into the study site, translate it into a conceptual hydrological model and implement it within a computationally robust algorithm. This tool also helps challenge and contrast competing paradigms such as the "uniqueness of place" vs "one model fits all". Using this interface, hydrologists can test different hypotheses and model representations, and stepwise build deeper understanding of the watershed of interest.

  10. Geographically Isolated Wetlands and Catchment Hydrology: A Modified Model Analyses

    NASA Astrophysics Data System (ADS)

    Evenson, G.; Golden, H. E.; Lane, C.; D'Amico, E.

    2014-12-01

    Geographically isolated wetlands (GIWs), typically defined as depressional wetlands surrounded by uplands, support an array of hydrological and ecological processes. However, key research questions concerning the hydrological connectivity of GIWs and their impacts on downgradient surface waters remain unanswered. This is particularly important for regulation and management of these systems. For example, in the past decade United States Supreme Court decisions suggest that GIWs can be afforded protection if significant connectivity exists between these waters and traditional navigable waters. Here we developed a simulation procedure to quantify the effects of various spatial distributions of GIWs across the landscape on the downgradient hydrograph using a refined version of the Soil and Water Assessment Tool (SWAT), a catchment-scale hydrological simulation model. We modified the SWAT FORTRAN source code and employed an alternative hydrologic response unit (HRU) definition to facilitate an improved representation of GIW hydrologic processes and connectivity relationships to other surface waters, and to quantify their downgradient hydrological effects. We applied the modified SWAT model to an ~ 202 km2 catchment in the Coastal Plain of North Carolina, USA, exhibiting a substantial population of mapped GIWs. Results from our series of GIW distribution scenarios suggest that: (1) Our representation of GIWs within SWAT conforms to field-based characterizations of regional GIWs in most respects; (2) GIWs exhibit substantial seasonally-dependent effects upon downgradient base flow; (3) GIWs mitigate peak flows, particularly following high rainfall events; and (4) The presence of GIWs on the landscape impacts the catchment water balance (e.g., by increasing groundwater outflows). Our outcomes support the hypothesis that GIWs have an important catchment-scale effect on downgradient streamflow.

  11. Hydrological modelling in a "big data" era: a proof of concept of hydrological models as web services

    NASA Astrophysics Data System (ADS)

    Buytaert, Wouter; Vitolo, Claudia

    2013-04-01

    Dealing with the massive increase in global data availability of all sorts is increasingly being known as "big data" science. Indeed, largely leveraged by the internet, a new resource of data sets emerges that are so large and heterogeneous that they become awkward to work with. New algorithms, methods and models are needed to filter such data to find trends, test hypotheses, make predictions and quantify uncertainties. As a considerable share of the data relate to environmental processes (e.g., satellite images, distributed sensor networks), this evolution provides exciting challenges for environmental sciences, and hydrology in particular. Web-enabled models are a promising approach to process large and distributed data sets, and to provide tailored products for a variety of end-users. It will also allow hydrological models to be used as building blocks in larger earth system simulation systems. However, in order to do so we need to reconsider the ways that hydrological models are built, results are made available, and uncertainties are quantified. We present the results of an experimental proof of concept of a hydrological modelling web-service to process heterogeneous hydrological data sets. The hydrological model itself consists of a set of conceptual model routines implemented with on a common platform. This framework is linked to global and local data sets through web standards provided by the Open Geospatial Consortium, as well as to a web interface that enables an end-user to request stream flow simulations from a self-defined location. In essence, the proof-of-concept can be seen as an implementation of the "Models of Everywhere" concept introduced by Beven in 2007. Although the setup is operational and effectively simulates stream flow, we identify several bottlenecks for optimal hydrological simulation in a web-context. The major challenges we identify are related to (1) model selection; (2) uncertainty quantification, and (3) user interaction and

  12. 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

  13. The One-Water Hydrologic Flow Model - The next generation in fully integrated hydrologic simulation software

    NASA Astrophysics Data System (ADS)

    Boyce, S. E.; Hanson, R. T.

    2015-12-01

    The One-Water Hydrologic Flow Model (MF-OWHM) is a MODFLOW-based integrated hydrologic flow model 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. MF-OWHM fully links the movement and use of groundwater, surface water, and imported water for consumption by agriculture and natural vegetation on the landscape, and for potable and other uses within a supply-and-demand framework. MF-OWHM is based on the Farm Process for MODFLOW-2005 combined with Local Grid Refinement, Streamflow Routing, Surface-water Routing Process, Seawater Intrusion, Riparian Evapotranspiration, and the Newton-Raphson solver. MF-OWHM also includes linkages for deformation-, flow-, and head-dependent flows; additional observation and parameter options for higher-order calibrations; and redesigned code for facilitation of self-updating models and faster simulation run times. The next version of MF-OWHM, currently under development, will include a new surface-water operations module that simulates dynamic reservoir operations, the conduit flow process for karst aquifers and leaky pipe networks, a new subsidence and aquifer compaction package, and additional features and enhancements to enable more integration and cross communication between traditional MODFLOW packages. By retaining and tracking the water within the hydrosphere, MF-OWHM accounts for "all of the water everywhere and all of the time." This philosophy provides more confidence in the water accounting by the scientific community and provides the public a foundation needed to address wider classes of problems such as evaluation of conjunctive-use alternatives and sustainability analysis, including potential adaptation and mitigation strategies, and best management practices. By Scott E. Boyce and Randall T. Hanson

  14. 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 (M

  15. Modelling hydrological systems under change: sociohydrology and sustainable development

    NASA Astrophysics Data System (ADS)

    Montanari, A.

    2012-04-01

    Understanding the behaviours of hydrological systems under a changing environment is a challenging research question, in view of the potentially limited representativity of historical information and the several interrogatives from society about the future of water resources. Indeed, parameter values and model structures identified from past observations might be of limited value to simulate the impact of environmental changes, in view of the presence of non-stationarity. However, historical information and the assumption of stationarity still are key tools to predict the future dynamics of ecological and hydrological processes. In fact, non-stationarity is a deterministic change of the statistics of the involved processes. Therefore, understanding the behaviours of changing systems requires the identification of an analytical relationship explaining non-stationarity, namely, how the above statistics will change along time. Once the latter information is acquired, to incorporate it within a stationary model is a relatively straightforward development, thus readily building a non-stationary framework for the interpretation of change. In summary, to model change one first of all needs to understand and quantify change. If such understanding was missing there would be no change. Under this latter view, the key research question related to hydrological change is how to infer the future statistics of hydrological processes. A key tool to this end is the principle of sustainability which allows one to identify constraints on future behaviours based on water availability. Indeed, water is going to play a principal, integrating and regulating role for the future scene, through its link with societal development (including agriculture and energy production) and ecological systems. To analytically decipher such a role is a fundamental requirement and a first step to understand changing hydrological processes. This talk will inspect in detail the above research questions

  16. Distributed lag models for hydrological data.

    PubMed

    Rushworth, Alastair M; Bowman, Adrian W; Brewer, Mark J; Langan, Simon J

    2013-06-01

    The distributed lag model (DLM), used most prominently in air pollution studies, finds application wherever the effect of a covariate is delayed and distributed through time. We specify modified formulations of DLMs to provide computationally attractive, flexible varying-coefficient models that are applicable in any setting in which lagged covariates are regressed on a time-dependent response. We investigate the application of such models to rainfall and river flow and in particular their role in understanding the impact of hidden variables at work in river systems. We apply two models to data from a Scottish mountain river, and we fit to some simulated data to check the efficacy of our model approach. During heavy rainfall conditions, changes in the influence of rainfall on flow arise through a complex interaction between antecedent ground wetness and a time-delay in rainfall. The models identify subtle changes in responsiveness to rainfall, particularly in the location of peak influence in the lag structure.

  17. An improved ARIMA model for hydrological simulations

    NASA Astrophysics Data System (ADS)

    Wang, H. R.; Wang, C.; Lin, X.; Kang, J.

    2014-04-01

    Auto Regressive Integrated Moving Average (ARIMA) model is often used to calculate time series data formed by inter-annual variations of monthly data. However, the influence brought about by inter-monthly variations within each year is ignored. Based on the monthly data classified by clustering analysis, the characteristics of time series data are extracted. An improved ARIMA model is developed accounting for both the inter-annual and inter-monthly variation. The correlation between characteristic quantity and monthly data within each year is constructed by regression analysis first. The model can be used for predicting characteristic quantity followed by the stationary treatment for characteristic quantity time series by difference. A case study is conducted to predict the precipitation in Lanzhou precipitation station, China, using the model, and the results show that the accuracy of the improved model is significantly higher than the seasonal model, with the mean residual achieving 9.41 mm and the forecast accuracy increasing by 21%.

  18. Vegetation Dynamics And Soil Moisture: Consequences For Hydrologic Modeling

    NASA Astrophysics Data System (ADS)

    Guardiola-Claramonte, M.; Troch, P. A.

    2007-12-01

    Current global population growth and economical development accelerates land cover conversion in many parts of the world. Introducing non-native species and woody species encroachment, with different water demands, can affect the partitioning of hydrological fluxes. The impacts on the hydrologic cycle at local to regional scales are poorly understood. The present study investigates the hydrologic implications of land use conversion from native vegetation to rubber. We first compare the vegetation dynamics of rubber (Hevea brasiliensis), a non- native specie in Southeast Asia, to the other main vegetation types in the study area. The experimental catchment, Nam Ken (69km 2), is located in the Xishuangbanna Prefecture (21 °N, 100 °E), in the south of Yunnan province in South China. From 2005 to 2006, we collected continuous records of 2 m deep soil moisture profiles in four different land covers (tea, secondary forest, grassland and rubber), and measured surface radiation in tea and rubber canopies. Our observations show that root water uptake by rubber during the dry season is controlled by the change of day-length, whereas water demand of the native vegetation starts with the arrival of the first monsoon rainfall. The different root water uptake dynamics of rubber result in distinct depletion of deeper layer soil moisture. Traditional evapotranspiration and soil moisture models are unable to simulate this specific behavior, thus a different conceptual model is needed to predict hydrologic changes due to land use conversion in the area.

  19. Hydrologic modeling in dynamic catchments: A data assimilation approach

    NASA Astrophysics Data System (ADS)

    Pathiraja, S.; Marshall, L.; Sharma, A.; Moradkhani, H.

    2016-05-01

    The transferability of conceptual hydrologic models in time is often limited by both their structural deficiencies and adopted parameterizations. Adopting a stationary set of model parameters ignores biases introduced by the data used to derive them, as well as any future changes to catchment conditions. Although time invariance of model parameters is one of the hallmarks of a high quality hydrologic model, very few (if any) models can achieve this due to their inherent limitations. It is therefore proposed to consider parameters as potentially time varying quantities, which can evolve according to signals in hydrologic observations. In this paper, we investigate the potential for Data Assimilation (DA) to detect known temporal patterns in model parameters from streamflow observations. It is shown that the success of the DA algorithm is strongly dependent on the method used to generate background (or prior) parameter ensembles (also referred to as the parameter evolution model). A range of traditional parameter evolution techniques are considered and found to be problematic when multiple parameters with complex time variations are estimated simultaneously. Two alternative methods are proposed, the first is a Multilayer approach that uses the EnKF to estimate hyperparameters of the temporal structure, based on apriori knowledge of the form of nonstationarity. The second is a Locally Linear approach that uses local linear estimation and requires no assumptions of the form of parameter nonstationarity. Both are shown to provide superior results in a range of synthetic case studies, when compared to traditional parameter evolution techniques.

  20. Is there a need for hydrological modelling in decision support systems for nuclear emergencies.

    PubMed

    Raskob, W; Heling, R; Zheleznyak, M

    2004-01-01

    This paper discusses the role of hydrological modelling in decision support systems for nuclear emergencies. In particular, most recent developments such as, the radionuclide transport models integrated in to the decision support system RODOS will be explored. Recent progress in the implementation of physically-based distributed hydrological models for operational forecasting in national and supranational centres, may support a closer cooperation between national hydrological services and therefore, strengthen the use of hydrological and radiological models implemented in decision support systems.

  1. Hydrological Modelling of The Guadiana Basin

    NASA Astrophysics Data System (ADS)

    Conan, C.; Bouraoui, F.; de Marsily, G.; Bidoglio, G.

    Increased anthropogenic activities such as agriculture, irrigation, industry, mining, ur- ban water supply and sewage treatment, have created significant environmental prob- lems. To ensure sustainable development of water resources, water managers need new strategies and suitable tools. In particular it is often compulsory that surface wa- ter and groundwater be managed simultaneously both in terms of quantity and quality at catchment scales. To this purpose, a model coupling SWAT (Soil and Water As- sessment Tool) and MODFLOW (Modular 3-D Flow model) was developed. SWAT is a quasi-distributed watershed model with a GIS interface that outlines the sub-basins and stream networks from a Digital Elevation Model (DEM) and calculates daily wa- ter balances from meteorological data, soil and land-use characteristics. The particular advantage of this model, compared to other fully distributed physically based mod- els, is that it requires a small amount of readily available input data. MODFLOW is a fully distributed model that calculates groundwater flow from aquifer characteris- tics. We have adapted this new coupled model SWAT-MODFLOW to a Mediterranean catchment, the Guadiana basin, and present the first results of this work. Only wa- ter quantity results are available at this stage. The validation consisted in comparing measured and predicted daily flow at the catchment and sub-catchment outlets for the period 1970-1995. The model accurately reproduced the decrease of the piezometric level, due to increased water abstraction, and the exchanges between surface water and ground-water. The sensitivity of the model to irrigation practices was evaluated. The usefulness of this model as a management tool has been illustrated through the analysis of alternative scenarios of agricultural practices and climate change.

  2. Anticipating the Role of SWOT in Hydrologic and Hydrodynamic Modeling

    NASA Astrophysics Data System (ADS)

    Pavelsky, T.; Biancamaria, S.; Andreadis, K.; Durand, M. T.; Schumann, G.

    2015-12-01

    The Surface Water and Ocean Topography (SWOT) satellite mission is a joint project of NASA and CNES, the French space agency. It aims to provide the first simultaneous, space-based measurements of inundation extent and water surface elevation in rivers, lakes, and wetlands around the world. Although the orbit repeat time is approximately 21 days, many areas of the earth will be viewed multiple times during this window. SWOT will observe rivers as narrow as 50-100 m and lakes as small as 0.01-0.06 km2, with height accuracies of ~10 cm for water bodies 1 km2 in area. Because SWOT will measure temporal variations in the height, width, and slope of rivers, several algorithms have been developed to estimate river discharge solely from SWOT measurements. Additionally, measurements of lake height and area will allow estimation of variability in lake water storage. These new hydrologic measurements will provide important sources of information both hydrologic and hydrodynamic models at regional to global scales. SWOT-derived estimates of water storage change and discharge will help to constrain simulation of the water budget in hydrologic models. Measurements of water surface elevation will provide similar constraints on hydrodynamic models of river flow. SWOT data will be useful for model calibration and validation, but perhaps the most exciting applications involve assimilation of SWOT data into models to enhance model robustness and provide denser temporal sampling than available from SWOT observations alone.

  3. Utilization of remote sensing observations in hydrologic models

    NASA Technical Reports Server (NTRS)

    Ragan, R. M.

    1977-01-01

    Most of the remote sensing related work in hydrologic modeling has centered on modifying existing models to take advantage of the capabilities of new sensor techniques. There has been enough success with this approach to insure that remote sensing is a powerful tool in modeling the watershed processes. Unfortunately, many of the models in use were designed without recognizing the growth of remote sensing technology. Thus, their parameters were selected to be map or field crew definable. It is believed that the real benefits will come through the evolution of new models having new parameters that are developed specifically to take advantage of our capabilities in remote sensing. The ability to define hydrologically active areas could have a significant impact. The ability to define soil moisture and the evolution of new techniques to estimate evoportransportation could significantly modify our approach to hydrologic modeling. Still, without a major educational effort to develop an understanding of the techniques used to extract parameter estimates from remote sensing data, the potential offered by this new technology will not be achieved.

  4. An event-based hydrologic simulation model for bioretention systems.

    PubMed

    Roy-Poirier, A; Filion, Y; Champagne, P

    2015-01-01

    Bioretention systems are designed to treat stormwater and provide attenuated drainage between storms. Bioretention has shown great potential at reducing the volume and improving the quality of stormwater. This study introduces the bioretention hydrologic model (BHM), a one-dimensional model that simulates the hydrologic response of a bioretention system over the duration of a storm event. BHM is based on the RECARGA model, but has been adapted for improved accuracy and integration of pollutant transport models. BHM contains four completely-mixed layers and accounts for evapotranspiration, overflow, exfiltration to native soils and underdrain discharge. Model results were evaluated against field data collected over 10 storm events. Simulated flows were particularly sensitive to antecedent water content and drainage parameters of bioretention soils, which were calibrated through an optimisation algorithm. Temporal disparity was observed between simulated and measured flows, which was attributed to preferential flow paths formed within the soil matrix of the field system. Modelling results suggest that soil water storage is the most important short-term hydrologic process in bioretention, with exfiltration having the potential to be significant in native soils with sufficient permeability. PMID:26524443

  5. Flash flood warning based on fully dynamic hydrology modelling

    NASA Astrophysics Data System (ADS)

    Pejanovic, Goran; Petkovic, Slavko; Cvetkovic, Bojan; Nickovic, Slobodan

    2016-04-01

    Numerical hydrologic modeling has achieved limited success in the past due to, inter alia, lack of adequate input data. Over the last decade, data availability has improved substantially. For modelling purposes, high-resolution data on topography, river routing, and land cover and soil features have meanwhile become available, as well as the observations such as radar precipitation information. In our study, we have implemented the HYPROM model (Hydrology Prognostic Model) to predict a flash flood event at a smaller-scale basin in Southern Serbia. HYPROM is based on the full set of governing equations for surface hydrological dynamics, in which momentum components, along with the equation of mass continuity, are used as full prognostic equations. HYPROM also includes a river routing module serving as a collector for the extra surface water. Such approach permits appropriate representation of different hydrology scales ranging from flash floods to flows of large and slow river basins. The use of full governing equations, if not appropriately parameterized, may lead to numerical instability systems when the surface water in a model is vanishing. To resolve these modelling problems, an unconditionally stable numerical scheme and a method for height redistribution avoiding shortwave height noise have been developed in HYPROM, which achieve numerical convergence of u, v and h when surface water disappears. We have applied HYPROM, driven by radar-estimated precipitation, to predict flash flooding occurred over smaller and medium-size river basins. Two torrential rainfall cases have been simulated to check the accuracy of the model: the exceptional flooding of May 2014 in Western Serbia, and the convective flash flood of January 2015 in Southern Serbia. The second episode has been successfully predicted by HYPROM in terms of timing and intensity six hours before the event occurred. Such flash flood warning system is in preparation to be operationally implemented in the

  6. On the Usefulness of Hydrologic Landscapes on Hydrologic Model calibration and Selection

    EPA Science Inventory

    Hydrologic Landscapes (HLs) are units that can be used in aggregate to describe the watershed-scale hydrologic response of an area through use of physical and climatic properties. The HL assessment unit is a useful classification tool to relate and transfer hydrologically meaning...

  7. On the Usefulness of Hydrologic Landscapes for Hydrologic Modeling and Water Management

    EPA Science Inventory

    Hydrologic Landscapes (HLs) are units that can be used in aggregate to describe the watershed-scale hydrologic response of an area through use of physical and climatic properties. The HL assessment unit is a useful classification tool to relate and transfer hydrologically meaning...

  8. 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

  9. 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.

  10. Modelling hydrological responses of Nerbioi River Basin to Climate Change

    NASA Astrophysics Data System (ADS)

    Mendizabal, Maddalen; Moncho, Roberto; Chust, Guillem; Torp, Peter

    2010-05-01

    Future climate change will affect aquatic systems on various pathways. Regarding the hydrological cycle, which is a very important pathway, changes in hydrometeorological variables (air temperature, precipitation, evapotranspiration) in first order impact discharges. The fourth report assessment of the Intergovernmental Panel for Climate Change indicates there is evidence that the recent warming of the climate system would result in more frequent extreme precipitation events, increased winter flood likelihoods, increased and widespread melting of snow and ice, longer and more widespread droughts, and rising sea level. Available research and climate model outputs indicate a range of hydrological impacts with likely to very likely probabilities (67 to 99%). For example, it is likely that up to 20% of the world population will live in areas where river flood potential could increase by the 2080s. In Spain, within the Atlantic basin, the hydrological variability will increase in the future due to the intensification of the positive phase of the North Atlantic Oscillation (NAO) index. This might cause flood frequency decreases, but its magnitude does not decrease. The generation of flood, its duration and magnitude are closely linked to changes in winter precipitation. The climatic conditions and relief of the Iberian Peninsula favour the generation of floods. In Spain, floods had historically strong socio-economic impacts, with more than 1525 victims in the past five decades. This upward trend of hydrological variability is expected to remain in the coming decades (medium uncertainty) when the intensification of the positive phase of the NAO index (MMA, 2006) is considered. In order to adapt or minimize climate change impacts in water resources, it is necessary to use climate projections as well as hydrological modelling tools. The main objective of this paper is to evaluate and assess the hydrological response to climate changes in flow conditions in Nerbioi river

  11. 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

    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".

  12. Modeling Soil Moisture Fields Using the Distributed Hydrologic Model MOBIDIC

    NASA Astrophysics Data System (ADS)

    Castillo, A. E.; Entekhabi, D.; Castelli, F.

    2011-12-01

    The Modello Bilancio Idrologico DIstributo e Continuo (MOBIDIC) is a fully-distributed physically-based basin hydrologic model [Castelli et al., 2009]. MOBIDIC represents watersheds using a system or reservoirs that interact through both mass and energy fluxes. The model uses a single-layered soil on a grid. For each grid element, soil moisture is conceptually partitioned into gravitational (free) and capillary-bound water. For computational parsimony, linear parameterization is used for infiltration rather than solving it using the nonlinear Richard's Equation. Previous applications of MOBIDIC assessed model performance based on streamflow which is a flux. In this study, the MOBIDIC simulated soil moisture, a state variable, is compared against observed values as well as values simulated by the legacy Simultaneous Heat and Water (SHAW) model [Flerchinger, 2000] which was chosen as the benchmark. Results of initial simulations with the original version of MOBIDIC prompted several model modifications such as changing the parameterization of evapotranspiration and adding capillary rise to make the model more robust in simulating the dynamics of soil moisture. In order to test the performance of the modified MOBIDIC, both short-term (a few weeks) and extended (multi-year) simulations were performed for 3 well-studied sites in the US: two sites are mountainous with deep groundwater table and semiarid climate, while the third site is fluvial with shallow groundwater table and temperate climate. For the multi-year simulations, both MOBIDIC and SHAW performed well in modeling the daily observed soil moisture. The simulations also illustrated the benefits of adding the capillary rise module and the other modifications introduced. Moreover, it was successfully demonstrated that MOBIDIC, with some conceptual approaches and some simplified parameterizations, can perform as good, if not better, than the more sophisticated SHAW model. References Castelli, F., G. Menduni, and B

  13. Mid-Holocene Hydrologic Model of the Shingobee Watershed, Minnesota

    NASA Astrophysics Data System (ADS)

    Filby, Sheryl K.; Locke, Sharon M.; Person, Mark A.; Winter, Thomas C.; Rosenberry, Donald O.; Nieber, John L.; Gutowski, William J.; Ito, Emi

    2002-11-01

    A hydrologic model of the Shingobee Watershed in north-central Minnesota was developed to reconstruct mid-Holocene paleo-lake levels for Williams Lake, a surface-water body located in the southern portion of the watershed. Hydrologic parameters for the model were first estimated in a calibration exercise using a 9-yr historical record (1990-1998) of climatic and hydrologic stresses. The model reproduced observed temporal and spatial trends in surface/groundwater levels across the watershed. Mid-Holocene aquifer and lake levels were then reconstructed using two paleoclimatic data sets: CCM1 atmospheric general circulation model output and pollen-transfer functions using sediment core data from Williams Lake. Calculated paleo-lake levels based on pollen-derived paleoclimatic reconstructions indicated a 3.5-m drop in simulated lake levels and were in good agreement with the position of mid-Holocene beach sands observed in a Williams Lake sediment core transect. However, calculated paleolake levels based on CCM1 climate forcing produced only a 0.05-m drop in lake levels. We found that decreases in winter precipitation rather than temperature increases had the largest effect on simulated mid-Holocene lake levels. The study illustrates how watershed models can be used to critically evaluate paleoclimatic reconstructions by integrating geologic, climatic, limnologic, and hydrogeologic data sets.

  14. Modeling of subglacial hydrological development following rapid supraglacial lake drainage

    PubMed Central

    Dow, C F; Kulessa, B; Rutt, I C; Tsai, V C; Pimentel, S; Doyle, S H; van As, D; Lindbäck, K; Pettersson, R; Jones, G A; Hubbard, A

    2015-01-01

    The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and examine whether substantial, efficient subglacial channels can form during or following lake drainage events and their effect on the water pressure in the surrounding distributed system. We force the model with field data from a lake drainage site, 70 km from the terminus of Russell Glacier in West Greenland. The model outputs suggest that efficient subglacial channels do not readily form in the vicinity of the lake during rapid drainage and instead water is evacuated primarily by a transient turbulent sheet and the distributed system. Following lake drainage, channels grow but are not large enough to reduce the water pressure in the surrounding distributed system, unless preexisting channels are present throughout the domain. Our results have implications for the analysis of subglacial hydrological systems in regions where rapid lake drainage provides the primary mechanism for surface-to-bed connections. Key Points Model for subglacial hydrological analysis of rapid lake drainage events Limited subglacial channel growth during and following rapid lake drainage Persistence of distributed drainage in inland areas where channel growth is limited PMID:26640746

  15. eWaterCycle: A high resolution global hydrological model

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    In 2013, the eWaterCycle project was started, which has the ambitious goal to run a high resolution global hydrological model. Starting point was the PCR-GLOBWB built by Utrecht University. The software behind this model will partially be re-engineered in order to enable to run it in a High Performance Computing (HPC) environment. The aim is to have a spatial resolution of 1km x 1km. The idea is also to run the model in real-time and forecasting mode, using data assimilation. An on-demand hydraulic model will be available for detailed flow and flood forecasting in support of navigation and disaster management. The project faces a set of scientific challenges. First, to enable the model to run in a HPC environment, model runs were analyzed to examine on which parts of the program most CPU time was spent. These parts were re-coded in Open MPI to allow for parallel processing. Different parallelization strategies are thinkable. In our case, it was decided to use watershed logic as a first step to distribute the analysis. There is rather limited recent experience with HPC in hydrology and there is much to be learned and adjusted, both on the hydrological modeling side and the computer science side. For example, an interesting early observation was that hydrological models are, due to their localized parameterization, much more memory intensive than models of sister-disciplines such as meteorology and oceanography. Because it would be deadly to have to swap information between CPU and hard drive, memory management becomes crucial. A standard Ensemble Kalman Filter (enKF) would, for example, have excessive memory demands. To circumvent these problems, an alternative to the enKF was developed that produces equivalent results. This presentation shows the most recent results from the model, including a 5km x 5km simulation and a proof of concept for the new data assimilation approach. Finally, some early ideas about financial sustainability of an operational global

  16. Selection of Hydrological Model for Waterborne Release

    SciTech Connect

    Blanchard, A.

    1999-04-21

    Following a request from the States of South Carolina and Georgia, downstream radiological consequences from postulated accidental aqueous releases at the three Savannah River Site nonreactor nuclear facilities will be examined. This evaluation will aid in determining the potential impacts of liquid releases to downstream populations on the Savannah River. The purpose of this report is to evaluate the two available models and determine the appropriate model for use in following waterborne release analyses. Additionally, this report will document the accidents to be used in the future study.

  17. Drought Analysis for River Basins, Using the Hydrological Model SIMGRO

    NASA Astrophysics Data System (ADS)

    Querner, E.; van Lanen, H.; Rhebergen, W.

    2009-05-01

    Drought is a recurring and worldwide phenomenon, with spatial and temporal characteristics that vary significantly from one region to another. Drought has major impacts on society and affects among others the environment and the economy. Impacts are likely to increase with time as societies demands higher services for water and the environment. This will even be more pronounced in the coming decades with the projected climate change, i.e. droughts are becoming more severe in large parts of the world. The prediction of droughts is an essential part of impact assessment for current and future conditions, as part of integrated land and water management. An important question is how changes in meteorological drought will propagate into hydrological droughts in terms of changes in the groundwater system or in the river flow. The objective of our study is to develop and test tools that quantify the space-time development of droughts in a river basin. The spatial aspect of a hydrological drought (spatially-distributed recharge and groundwater heads), in a river basin brings different challenges with respect to describing the characteristics of a drought, such as: onset, duration, severity and extend. We used the regional hydrological model SIMGRO as a basis to generate the necessary data for the drought analysis. SIMGRO is a distributed physically-based model that simulates regional transient saturated groundwater flow, unsaturated flow, actual evapotranspiration, sprinkler irrigation, stream flow, groundwater and surface water levels as a response to rainfall, reference evapotranspiration, and groundwater abstraction. The model is used within the GIS environment Arc-View, which enables the use of digital data, such as soil map, land use, watercourses, as input data for the model. It is also a tool for analysis, because interactively data and results can be presented, as will be shown. Droughts in different hydrological variables (recharge, groundwater heads, river flow

  18. 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

  19. 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

  20. Subgrid spatial variability of soil hydraulic functions for hydrological modelling

    NASA Astrophysics Data System (ADS)

    Kreye, Phillip; Meon, Günter

    2016-07-01

    State-of-the-art hydrological applications require a process-based, spatially distributed hydrological model. Runoff characteristics are demanded to be well reproduced by the model. Despite that, the model should be able to describe the processes at a subcatchment scale in a physically credible way. The objective of this study is to present a robust procedure to generate various sets of parameterisations of soil hydraulic functions for the description of soil heterogeneity on a subgrid scale. Relations between Rosetta-generated values of saturated hydraulic conductivity (Ks) and van Genuchten's parameters of soil hydraulic functions were statistically analysed. An universal function that is valid for the complete bandwidth of Ks values could not be found. After concentrating on natural texture classes, strong correlations were identified for all parameters. The obtained regression results were used to parameterise sets of hydraulic functions for each soil class. The methodology presented in this study is applicable on a wide range of spatial scales and does not need input data from field studies. The developments were implemented into a hydrological modelling system.

  1. Distributed Hydrologic Modeling Apps for Decision Support in the Cloud

    NASA Astrophysics Data System (ADS)

    Swain, N. R.; Latu, K.; Christiensen, S.; Jones, N.; Nelson, J.

    2013-12-01

    Advances in computation resources and greater availability of water resources data represent an untapped resource for addressing hydrologic uncertainties in water resources decision-making. The current practice of water authorities relies on empirical, lumped hydrologic models to estimate watershed response. These models are not capable of taking advantage of many of the spatial datasets that are now available. Physically-based, distributed hydrologic models are capable of using these data resources and providing better predictions through stochastic analysis. However, there exists a digital divide that discourages many science-minded decision makers from using distributed models. This divide can be spanned using a combination of existing web technologies. The purpose of this presentation is to present a cloud-based environment that will offer hydrologic modeling tools or 'apps' for decision support and the web technologies that have been selected to aid in its implementation. Compared to the more commonly used lumped-parameter models, distributed models, while being more intuitive, are still data intensive, computationally expensive, and difficult to modify for scenario exploration. However, web technologies such as web GIS, web services, and cloud computing have made the data more accessible, provided an inexpensive means of high-performance computing, and created an environment for developing user-friendly apps for distributed modeling. Since many water authorities are primarily interested in the scenario exploration exercises with hydrologic models, we are creating a toolkit that facilitates the development of a series of apps for manipulating existing distributed models. There are a number of hurdles that cloud-based hydrologic modeling developers face. One of these is how to work with the geospatial data inherent with this class of models in a web environment. Supporting geospatial data in a website is beyond the capabilities of standard web frameworks and it

  2. Computationally efficient calibration of WATCLASS Hydrologic models using surrogate optimization

    NASA Astrophysics Data System (ADS)

    Kamali, M.; Ponnambalam, K.; Soulis, E. D.

    2007-07-01

    In this approach, exploration of the cost function space was performed with an inexpensive surrogate function, not the expensive original function. The Design and Analysis of Computer Experiments(DACE) surrogate function, which is one type of approximate models, which takes correlation function for error was employed. The results for Monte Carlo Sampling, Latin Hypercube Sampling and Design and Analysis of Computer Experiments(DACE) approximate model have been compared. The results show that DACE model has a good potential for predicting the trend of simulation results. The case study of this document was WATCLASS hydrologic model calibration on Smokey-River watershed.

  3. Hydrologic modeling of soil water storage in landfill cover systems

    SciTech Connect

    Barnes, F.J.; Rodgers, J.C.

    1987-01-01

    The accuracy of modeling soil water storage by two hydrologic models, CREAMS and HELP, was tested by comparing simulation results with field measurements of soil moisture in eight experimental landfill cover systems having a range of well-defined soil profiles and vegetative covers. Regression analysis showed that CREAMS generally represented soil moisture more accurately than HELP simulations. Soil profiles that more closely resembled natural agricultural soils were more accurately modeled than highly artificial layered soil profiles. Precautions for determining parameter values for model input and for interpreting simulation results are discussed.

  4. Defining prior probabilities for hydrologic model structures in UK catchments

    NASA Astrophysics Data System (ADS)

    Clements, Michiel; Pianosi, Francesca; Wagener, Thorsten; Coxon, Gemma; Freer, Jim; Booij, Martijn

    2014-05-01

    The selection of a model structure is an essential part of the hydrological modelling process. Recently flexible modeling frameworks have been proposed where hybrid model structures can be obtained by mixing together components from a suite of existing hydrological models. When sufficient and reliable data are available, this framework can be successfully utilised to identify the most appropriate structure, and associated optimal parameters, for a given catchment by maximizing the different models ability to reproduce the desired range of flow behaviour. In this study, we use a flexible modelling framework to address a rather different question: can the most appropriate model structure be inferred a priori (i.e without using flow observations) from catchment characteristics like topography, geology, land use, and climate? Furthermore and more generally, can we define priori probabilities of different model structures as a function of catchment characteristics? To address these questions we propose a two-step methodology and demonstrate it by application to a national database of meteo-hydrological data and catchment characteristics for 89 catchments across the UK. In the first step, each catchment is associated with its most appropriate model structure. We consider six possible structures obtained by combining two soil moisture accounting components widely used in the UK (Penman and PDM) and three different flow routing modules (linear, parallel, leaky). We measure the suitability of a model structure by the probability of finding behavioural parameterizations for that model structure when applied to the catchment under study. In the second step, we use regression analysis to establish a relation between selected model structures and the catchment characteristics. Specifically, we apply Classification And Regression Trees (CART) and show that three catchment characteristics, the Base Flow Index, the Runoff Coefficient and the mean Drainage Path Slope, can be used

  5. Coupled Dynamic Modeling to Assess Human Impact on Watershed Hydrology

    NASA Astrophysics Data System (ADS)

    Mohammed, I. N.; Tsai, Y.; Turnbull, S.; Bomblies, A.; Zia, A.

    2014-12-01

    Humans are intrinsic to the hydrologic system, both as agents of change and as beneficiaries of ecosystem services. This connection has been underappreciated in hydrology. We present a modeling linkage framework of an agent-based land use change model with a physical-based watershed model. The coupled model framework presented constitutes part of an integrated assessment model that is being developed to study human-ecosystem interaction in Missisquoi Bay, spanning Vermont and Québec, which is experiencing high concentrations of nutrients from the Missisquoi River watershed. The integrated assessment approach proposed is comprised of linking two simulation models: the Interactive Land-Use Transition Agent-Based Model (ILUTABM) and a physically based process model, the Regional Hydro-Ecological Simulation System (RHESSys). The ILUTABM treats both landscape and landowners as agents and simulates annual land-use patterns resulting from landowners annual land-use decisions and Best Management Practices (BMPs) adaptations to landowners utilities, land productivity and perceived impacts of floods. The Missisquoi River at Swanton watershed RHESSys model (drainage area of 2,200 km2) driven by climate data was first calibrated to daily streamflows and water quality sensor data at the watershed outlet. Simulated land-use patterns were then processed to drive the calibrated RHESSys model to obtain streamflow nutrient loading realizations. Nutrients loading realizations are then examined and routed back to the ILUTAB model to obtain public polices needed to manage the Missisquoi watershed as well as the Lake Champlain in general. We infer that the applicability of this approach can be generalized to other similar watersheds. Index Terms: 0402: Agricultural systems; 1800: Hydrology; 1803: Anthropogenic effects; 1834 Human impacts; 6344: System operation and management; 6334: Regional Planning

  6. Continuous streamflow simulation with the HRCDHM distributed hydrologic model

    NASA Astrophysics Data System (ADS)

    Carpenter, Theresa M.; Georgakakos, Konstantine P.

    2004-10-01

    The objective of the authors' work in the area of distributed modeling is to determine the manner with which rainfall input and model parameter uncertainty shapes the character of the flow simulation and prediction uncertainty of distributed hydrologic models. Toward this end and as a tool for the investigation, a distributed model, HRCDHM, has been formulated and tested as part of the NOAA Distributed Model Intercomparison Project (DMIP). This paper examines hourly flow simulations from HRCDHM applied with operational data obtained for the DMIP study watersheds. HRCDHM is a catchment-based, distributed input, distributed parameter hydrologic model. The hydrologic processes of infiltration/percolation, evapotranspiration, surface and subsurface flow (includes leakage to deep groundwater) are modeled along the vertical direction on a subcatchment basis in a manner similar to the Sacramento Soil Moisture Accounting model, and kinematic channel routing carries the flow through the network of subcatchments to the watershed outlet, providing capability for spatially distributed flow simulations. Subcatchment physical properties are derived from various digital terrain and land-characteristics databases through GIS processing and they are used to derive spatially distributed model parameter values. The NWS operational WSR-88D hourly radar rainfall estimates (Stage III product with pixel scale of approximately 4 km) constitute the rainfall forcing and a combination of model-derived and observed hourly surface meteorological data are used to produce the potential evapotranspiration forcing. HRCDHM was applied to and was calibrated for five watersheds for the period May 1993 through June 2000. Validation was done with data not used during the calibration period. This application shows that: (a) the HRCDHM, when forced with hourly data, is able to reproduce well the observed hourly streamflow at the outlet of each study watershed; and (b) beyond these outlet locations

  7. Hydrologic modeling of reclaimed strip mine spoil

    SciTech Connect

    Edwards, K.B.; Stoertz, M.W.; Turney, D.C.

    1998-12-31

    A numerical groundwater flow model (MODFLOW) of a surface coal mine in southeast Ohio was calibrated under steady state conditions to match measured heads by varying hydraulic conductivity (K) and recharge (R). Sensitivity studies indicated that K was not largely dependent on the poorly quantified underclay elevation or on the lake boundary condition. The baseflow recharge was determined to be between 8 and 60 mm/yr (1 to 6% of annual rainfall) and K between 0.004 and 0.01 cm/s for the spoil aquifer.

  8. Physically Based Mountain Hydrological Modelling using Reanalysis Data in Patagonia

    NASA Astrophysics Data System (ADS)

    Krogh, S.; Pomeroy, J. W.; McPhee, J. P.

    2013-05-01

    Remote regions in South America are often characterized by insufficient observations of meteorology for robust hydrological model operation. Yet water resources must be quantified, understood and predicted in order to develop effective water management policies. Here, we developed a physically based hydrological model for a major river in Patagonia using the modular Cold Regions Hydrological Modelling Platform (CRHM) in order to better understand hydrological processes leading to streamflow generation in this remote region. The Baker River -with the largest mean annual streamflow in Chile-, drains snowy mountains, glaciers, wet forests, peat and semi-arid pampas into a large lake. Meteorology over the basin is poorly monitored in that there are no high elevation weather stations and stations at low elevations are sparsely distributed, only measure temperature and rainfall and are poorly maintained. Streamflow in the basin is gauged at several points where there are high quality hydrometric stations. In order to quantify the impact of meteorological data scarcity on prediction, two additional data sources were used: the ERA-Interim (ECMWF Re-analyses) and CFSR (Climate Forecast System Reanalysis) atmospheric reanalyses. Precipitation temporal distribution and magnitude from the models and observations were compared and the reanalysis data was found to have about three times the number of days with precipitation than the observations did. Better synchronization between measured peak streamflows and modeled precipitation was found compared to observed precipitation. These differences are attributed to: (i) lack of any snowfall observations (so precipitation records does not consider snowfall events) and (ii) available rainfall observations are all located at low altitude (<500 m a.s.l), and miss the occurrence of high altitude precipitation events. CRHM parameterization was undertaken by using local physiographic and vegetation characteristics where available and

  9. What is the minimal geomorphology based hydrological model?

    NASA Astrophysics Data System (ADS)

    de Lavenne, Alban; Rigon, Riccardo; Formetta, Giuseppe; Cudennec, Christophe

    2013-04-01

    Hydrological modelling is a usefull tool to understand hydrological process. With knowledge increasing, models often become more complex. Drived by each researchers hypothesis, new components are added years after years. However, in many cases, the need of this complexity appears to be unnecessary or, in a context of lack of data, even unsuitable. We propose a modelling framework improvement of geomorphology-based models. By updating step by step models' structure and by checking separatly hypotheses for improving model performance, we aim to improve our understanding of catchment behaviour. We apply this framework on six catchments in Brittany, France. With catchment's area varying from 5km² to 316km², we explore heterogeneous situations to enrich the discussion about model's efficiency, robustness and facility of implementation. Simulations are performed from monthly time scale to annual time scale using 5 years of rainfall-runoff data. We compare the improvement bring by changing progressively model's structure. This is done by splitting catchment dynamics through the play of several flow velocities inside one or several width functions. We test separatly different hypothesis of model improvement, like accounting of velocity and rainfall spatio-temporal variability, as well as considering hydrodynamic dispersion. Models are parametrized using a particle swarm optimisation algorithm. With a minimum complexity level, this framework enable to choose wich model suits the objectives and how to take advantage of the available data.

  10. Advancing reservoir operation description in physically based hydrological models

    NASA Astrophysics Data System (ADS)

    Anghileri, Daniela; Giudici, Federico; Castelletti, Andrea; Burlando, Paolo

    2016-04-01

    Last decades have seen significant advances in our capacity of characterizing and reproducing hydrological processes within physically based models. Yet, when the human component is considered (e.g. reservoirs, water distribution systems), the associated decisions are generally modeled with very simplistic rules, which might underperform in reproducing the actual operators' behaviour on a daily or sub-daily basis. For example, reservoir operations are usually described by a target-level rule curve, which represents the level that the reservoir should track during normal operating conditions. The associated release decision is determined by the current state of the reservoir relative to the rule curve. This modeling approach can reasonably reproduce the seasonal water volume shift due to reservoir operation. Still, it cannot capture more complex decision making processes in response, e.g., to the fluctuations of energy prices and demands, the temporal unavailability of power plants or varying amount of snow accumulated in the basin. In this work, we link a physically explicit hydrological model with detailed hydropower behavioural models describing the decision making process by the dam operator. In particular, we consider two categories of behavioural models: explicit or rule-based behavioural models, where reservoir operating rules are empirically inferred from observational data, and implicit or optimization based behavioural models, where, following a normative economic approach, the decision maker is represented as a rational agent maximising a utility function. We compare these two alternate modelling approaches on the real-world water system of Lake Como catchment in the Italian Alps. The water system is characterized by the presence of 18 artificial hydropower reservoirs generating almost 13% of the Italian hydropower production. Results show to which extent the hydrological regime in the catchment is affected by different behavioural models and reservoir

  11. Distributed Hydrologic Modeling of LID in The Woodlands, Texas

    NASA Astrophysics Data System (ADS)

    Bedient, P.; Doubleday, G.; Sebastian, A.; Fang, N.

    2012-12-01

    As early as the 1960s, the Woodlands, TX employed stormwater management similar to modern Low Impact Development (LID) design. Innovative for its time, the master drainage plan attempted to minimize adverse impact to the 100-year floodplain and reduce the impact of development on the natural environment. Today, it is Texas's most celebrated master-planned community. This paper employs the use of NEXRAD radar rainfall in the distributed hydrologic model, VfloTM, to evaluate the effectiveness of The Woodlands master drainage design as a stormwater management technique. Three models were created in order to analyze the rainfall-runoff response of The Woodlands watershed under different development conditions: two calibrated, fully distributed hydrologic models to represent the (A) undeveloped and (B) 2006-development conditions and (C) a hypothetical, highly urbanized model, representing Houston-style development. Parameters, such as imperviousness and land cover, were varied in order to represent the different developed conditions. The A and B models were calibrated using NEXRAD radar rainfall for two recent storm events in 2008 and 2009. All three models were used to compare peak flows, discharge volumes and time to peak of hydrographs for the recent radar rainfall events and a historical gaged rainfall event that occurred in 1974. Results show that compared to pre-developed conditions, the construction of The Woodlands resulted in an average increase in peak flows of only 15% during small storms and 27% during a major event. Furthermore, when compared to the highly urbanized model, peak flows are often two to three times smaller for the 2006-model. In the 2006-model, the peak flow of the 100 year event was successfully attenuated, suggesting that the design of The Woodlands effectively protects the development from the 1% occurrence storm event using LID practices and reservoirs. This study uses a calibrated hydrologic distributed-model supported by NEXRAD radar

  12. Effective and efficient algorithm for multiobjective optimization of hydrologic models

    NASA Astrophysics Data System (ADS)

    Vrugt, Jasper A.; Gupta, Hoshin V.; Bastidas, Luis A.; Bouten, Willem; Sorooshian, Soroosh

    2003-08-01

    Practical experience with the calibration of hydrologic models suggests that any single-objective function, no matter how carefully chosen, is often inadequate to properly measure all of the characteristics of the observed data deemed to be important. One strategy to circumvent this problem is to define several optimization criteria (objective functions) that measure different (complementary) aspects of the system behavior and to use multicriteria optimization to identify the set of nondominated, efficient, or Pareto optimal solutions. In this paper, we present an efficient and effective Markov Chain Monte Carlo sampler, entitled the Multiobjective Shuffled Complex Evolution Metropolis (MOSCEM) algorithm, which is capable of solving the multiobjective optimization problem for hydrologic models. MOSCEM is an improvement over the Shuffled Complex Evolution Metropolis (SCEM-UA) global optimization algorithm, using the concept of Pareto dominance (rather than direct single-objective function evaluation) to evolve the initial population of points toward a set of solutions stemming from a stable distribution (Pareto set). The efficacy of the MOSCEM-UA algorithm is compared with the original MOCOM-UA algorithm for three hydrologic modeling case studies of increasing complexity.

  13. Integrating snowfall limit forecasts to improve hydrological modeling

    NASA Astrophysics Data System (ADS)

    Tobin, C.; Rinaldo, A.; Schaefli, B.

    2012-04-01

    Flood forecasting in mountainous areas requires accurate partitioning between rain and snowfall; an incorrect snow/rainfall limit (on daily or sub-daily timescales) typically implies a significant over- (or under-)estimation of the source catchment areas contributing to runoff and infiltration. This study details the development of a snow/rainfall partitioning method which incorporates snowfall limit information from Limited Area Models (LAMs) to improve catchment-scale hydrological modeling. LAMs consider the vertical, humid, atmospheric structure including wet bulb temperature in their snowfall limit calculations. Such an approach is more physically-based than inferring snowfall limit estimates based on dry, ground temperature measurements, which is the standard procedure in most hydrological models. A case study involving complex topography in the Swiss Alps demonstrates the potential of the developed method with the integration of COSMO forecast re-analysis snowfall limit information. Such data and the new method are proven here to significantly improve runoff simulation, particularly in the spring when a large part of the catchment is close to saturation. Integrating LAM snowfall limits thereby provides good estimates of runoff contributing areas, with practical implications for operational hydrology in Alpine regions.

  14. A priori discretization quality metrics for distributed hydrologic modeling applications

    NASA Astrophysics Data System (ADS)

    Liu, Hongli; Tolson, Bryan; Craig, James; Shafii, Mahyar; Basu, Nandita

    2016-04-01

    In distributed hydrologic modelling, a watershed is treated as a set of small homogeneous units that address the spatial heterogeneity of the watershed being simulated. The ability of models to reproduce observed spatial patterns firstly depends on the spatial discretization, which is the process of defining homogeneous units in the form of grid cells, subwatersheds, or hydrologic response units etc. It is common for hydrologic modelling studies to simply adopt a nominal or default discretization strategy without formally assessing alternative discretization levels. This approach lacks formal justifications and is thus problematic. More formalized discretization strategies are either a priori or a posteriori with respect to building and running a hydrologic simulation model. A posteriori approaches tend to be ad-hoc and compare model calibration and/or validation performance under various watershed discretizations. The construction and calibration of multiple versions of a distributed model can become a seriously limiting computational burden. Current a priori approaches are more formalized and compare overall heterogeneity statistics of dominant variables between candidate discretization schemes and input data or reference zones. While a priori approaches are efficient and do not require running a hydrologic model, they do not fully investigate the internal spatial pattern changes of variables of interest. Furthermore, the existing a priori approaches focus on landscape and soil data and do not assess impacts of discretization on stream channel definition even though its significance has been noted by numerous studies. The primary goals of this study are to (1) introduce new a priori discretization quality metrics considering the spatial pattern changes of model input data; (2) introduce a two-step discretization decision-making approach to compress extreme errors and meet user-specified discretization expectations through non-uniform discretization threshold

  15. Development of a landscape unit delineation framework for ecoy-hydrologic models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A spatially distributed representation of basin hydrology and transport processes in eco-hydrological models facilitates the identification of critical source areas and the placement of management and conservation measures. Especially floodplains are critical landscape features that differ from nei...

  16. A NEW APPROACH TO HYDROLOGIC MODELING: DERIVED DISTRIBUTIONS REVISITED. (R824780)

    EPA Science Inventory

    A fractal geometric procedure to model hydrologic (geophysical) phenomena is introduced. The method consists of using derived distributions, obtained by transforming arbitrary multinomial multifractal measures via fractal interpolating functions, to represent observed hydrologic ...

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. Calibration of hydrologic models using flow-duration curves

    NASA Astrophysics Data System (ADS)

    Westerberg, I.; Younger, P.; Guerrero, J.; Beven, K.; Seibert, J.; Halldin, S.; Xu, C.

    2010-12-01

    The usefulness of hydrological models depends on their skill to mimic real-world hydrology as attested by some efficiency criterion. The suitability of traditional criteria, such as the Nash-Sutcliffe efficiency, for model calibration has been much debated. Discharge data are plentiful for a few decades around the 1970’s but much less available in the last decades since the reported number of discharge stations in the world has gone down substantially from the peak in the late 1970’s. At the same time global precipitation and climate data such as TRMM and ERA-Interim, used to drive hydrological models, have become more readily available in the last 10-20 years. This mismatch of observation time periods makes traditional model calibration difficult or even impossible for basins where there are no overlapping periods of model input and evaluation data. A new calibration method is proposed here that addresses this mismatch and at the same time accounts for uncertainty in discharge data. An estimation of the discharge-data uncertainty is used as a basis to set limits of acceptability for observed flow-duration curves. These limits are then used for model calibration and evaluation within a Generalised Likelihood Uncertainty Estimation (GLUE) framework. Advantages of the new approach include less risk of bias because of epistemic (knowledge) type input-output errors (e.g. no simulated discharge for an observed flow peak because of no rain gauges in the only part of the catchment where it rained), a calibration that addresses the model performance for the whole flow regime (low, medium and high flows) simultaneously and a more realistic uncertainty estimation since discharge uncertainty is addressed. The new method is most suitable for water-balance model applications. Additional limits of acceptability for snow-routine parameters will be needed in basins with snow and frozen soils.

  2. Hydrological modeling of an ungauged watershed in Southern Andes

    NASA Astrophysics Data System (ADS)

    Alarcon, Vladimir J.; Alcayaga, Hernán; Álvarez, Enrique

    2015-12-01

    In this research, MODIS MCD12Q1 land cover, and SRTM topographical datasets were used for developing hydrological models for two ungauged watersheds: Clarillo river watershed, and Los Almendros watershed. Both watersheds are located in central Chile. Coarse precipitation and stream flow data for Los Almendros catchment were used for calibration of stream flow for Los Almendros River. Acceptable fit (with R2 values ranging within 0.62 to 0.67) was achieved during calibration. The hydrological parameters were then extrapolated for Clarillo river watershed. Simulated annual mean flows for Clarillo River were then compared to annual flows reported in the literature. Simulated mean annual flows were shown to be within the range of historical means with most of the simulated flows falling between the first and third quartile of the measured means.

  3. Towards a high resolution, integrated hydrology model of North America.

    NASA Astrophysics Data System (ADS)

    Maxwell, R. M.; Condon, L. E.

    2015-12-01

    Recent studies demonstrate feedbacks between groundwater dynamics, overland flow, land surface and vegetation processes, and atmospheric boundary layer development that significantly affect local and regional climate across a range of climatic conditions. Furthermore, the type and distribution of vegetation cover alters land-atmosphere water and energy fluxes, as well as runoff generation and overland flow processes. These interactions can result in significant feedbacks on local and regional climate. In mountainous regions, recent research has shown that spatial and temporal variability in annual evapotranspiration, and thus water budgets, is strongly dependent on lateral groundwater flow; however, the full effects of these feedbacks across varied terrain (e.g. from plains to mountains) are not well understood. Here, we present a high-resolution, integrated hydrology model that covers much of continental North America and encompasses the Mississippi and Colorado watersheds. The model is run in a fully-transient manner at hourly temporal resolution incorporating fully-coupled land energy states and fluxes with integrated surface and subsurface hydrology. Connections are seen between hydrologic variables (such as water table depth) and land energy fluxes (such as latent heat) and spatial and temporal scaling is shown to span many orders of magnitude. Using these transient simulations as a proof of concept, we present a vision for future integrated simulation capabilities.

  4. Misrepresentation and amendment of soil moisture in conceptual hydrological modelling

    NASA Astrophysics Data System (ADS)

    Zhuo, Lu; Han, Dawei

    2016-04-01

    Although many conceptual models are very effective in simulating river runoff, their soil moisture schemes are generally not realistic in comparison with the reality (i.e., getting the right answers for the wrong reasons). This study reveals two significant misrepresentations in those models through a case study using the Xinanjiang model which is representative of many well-known conceptual hydrological models. The first is the setting of the upper limit of its soil moisture at the field capacity, due to the 'holding excess runoff' concept (i.e., runoff begins on repletion of its storage to the field capacity). The second is neglect of capillary rise of water movement. A new scheme is therefore proposed to overcome those two issues. The amended model is as effective as its original form in flow modelling, but represents more logically realistic soil water processes. The purpose of the study is to enable the hydrological model to get the right answers for the right reasons. Therefore, the new model structure has a better capability in potentially assimilating soil moisture observations to enhance its real-time flood forecasting accuracy. The new scheme is evaluated in the Pontiac catchment of the USA through a comparison with satellite observed soil moisture. The correlation between the XAJ and the observed soil moisture is enhanced significantly from 0.64 to 0.70. In addition, a new soil moisture term called SMDS (Soil Moisture Deficit to Saturation) is proposed to complement the conventional SMD (Soil Moisture Deficit).

  5. Evaluation of a hydrological model based on Bidirectional Reach (BReach)

    NASA Astrophysics Data System (ADS)

    Van Eerdenbrugh, Katrien; Van Hoey, Stijn; Verhoest, Niko E. C.

    2016-04-01

    Evaluation and discrimination of model structures is crucial to ensure an appropriate use of hydrological models. When evaluating model results by aggregating their quality in (a subset of) individual observations, overall results of this analysis sometimes conceal important detailed information about model structural deficiencies. Analyzing model results within their local (time) context can uncover this detailed information. In this research, a methodology called Bidirectional Reach (BReach) is proposed to evaluate and analyze results of a hydrological model by assessing the maximum left and right reach in each observation point that is used for model evaluation. These maximum reaches express the capability of the model to describe a subset of the evaluation data both in the direction of the previous (left) and of the following data (right). This capability is evaluated on two levels. First, on the level of individual observations, the combination of a parameter set and an observation is classified as non-acceptable if the deviation between the accompanying model result and the measurement exceeds observational uncertainty. Second, the behavior in a sequence of observations is evaluated by means of a tolerance degree. This tolerance degree expresses the condition for satisfactory model behavior in a data series and is defined by the percentage of observations within this series that can have non-acceptable model results. Based on both criteria, the maximum left and right reaches of a model in an observation represent the data points in the direction of the previous respectively the following observations beyond which none of the sampled parameter sets both are satisfactory and result in an acceptable deviation. After assessing these reaches for a variety of tolerance degrees, results can be plotted in a combined BReach plot that show temporal changes in the behavior of model results. The methodology is applied on a Probability Distributed Model (PDM) of the river

  6. Simultaneous calibration of hydrological models in geographical space

    NASA Astrophysics Data System (ADS)

    Bárdossy, András; Huang, Yingchun; Wagener, Thorsten

    2016-07-01

    Hydrological models are usually calibrated for selected catchments individually using specific performance criteria. This procedure assumes that the catchments show individual behavior. As a consequence, the transfer of model parameters to other ungauged catchments is problematic. In this paper, the possibility of transferring part of the model parameters was investigated. Three different conceptual hydrological models were considered. The models were restructured by introducing a new parameter η which exclusively controls water balances. This parameter was considered as individual to each catchment. All other parameters, which mainly control the dynamics of the discharge (dynamical parameters), were considered for spatial transfer. Three hydrological models combined with three different performance measures were used in three different numerical experiments to investigate this transferability. The first numerical experiment, involving individual calibration of the models for 15 selected MOPEX catchments, showed that it is difficult to identify which catchments share common dynamical parameters. Parameters of one catchment might be good for another catchment but not the opposite. In the second numerical experiment, a common spatial calibration strategy was used. It was explicitly assumed that the catchments share common dynamical parameters. This strategy leads to parameters which perform well on all catchments. A leave-one-out common calibration showed that in this case a good parameter transfer to ungauged catchments can be achieved. In the third numerical experiment, the common calibration methodology was applied for 96 catchments. Another set of 96 catchments was used to test the transfer of common dynamical parameters. The results show that even a large number of catchments share similar dynamical parameters. The performance is worse than those obtained by individual calibration, but the transfer to ungauged catchments remains possible. The performance of the

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

    SciTech Connect

    McManamay, Ryan A

    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

  8. Modeling Hydrologic and Vegetation Responses in Freshwater Wetlands

    NASA Astrophysics Data System (ADS)

    Chui, Ting Fong May; Low, Swee Yang; Liong, Shie-Yui

    2010-05-01

    Wetlands constitute 6 - 7 % of the Earth's land surface and provide various critical ecosystem services such as purifying the air and water, mitigating floods and droughts, and supporting wildlife habitats. Despite the importance of wetlands, they are under threat of degradation by human-induced land use changes and climate change. Even if the value of wetlands is recognized, they are often not managed properly or restored successfully due to an inadequate understanding of the ecosystems and their responses to management scenarios. A better understanding of the main components of wetlands, namely the interdependent hydrologic and vegetation systems, and the sensitivity of their responses to engineering works and climate change, is crucial for the preservation of wetlands. To assess these potential impacts, a model is developed in this study for characterizing the coupled dynamics between soil moisture and plant biomass in wetland habitats. The hydrology component of the model is based on the Richards' equation and simulates spatially-varying groundwater movement and provides information on soil moisture at different depths. The plant growth component of the model is described through an equation of the Lotka-Volterra type modified for plant growth dynamics and is adapted from published literature. The two components are coupled via transpiration and ecosystem carrying capacity for plants. Transpiration is modeled for both unsaturated and saturated zones, while the carrying capacity describes limiting oxygen and subsequent nutrient availability in the soil column as a function of water table depth. Vegetation is represented by two species characteristic of mudflat herbaceous plants ranging from facultative wetland to upland plants. The model is first evaluated using a simplified domain and the hydrological information available in the RG2 site of the Everglades wetlands region. The modeled water table fluctuations in general are comparable to field data collected on

  9. A GIS-based variable source area hydrology model

    NASA Astrophysics Data System (ADS)

    Frankenberger, Jane R.; Brooks, Erin S.; Walter, M. Todd; Walter, Michael F.; Steenhuis, Tammo S.

    1999-04-01

    Effective control of nonpoint source pollution from contaminants transported by runoff requires information about the source areas of surface runoff. Variable source hydrology is widely recognized by hydrologists, yet few methods exist for identifying the saturated areas that generate most runoff in humid regions. The Soil Moisture Routing model is a daily water balance model that simulates the hydrology for watersheds with shallow sloping soils. The model combines elevation, soil, and land use data within the geographic information system GRASS, and predicts the spatial distribution of soil moisture, evapotranspiration, saturation-excess overland flow (i.e., surface runoff), and interflow throughout a watershed. The model was applied to a 170 hectare watershed in the Catskills region of New York State and observed stream flow hydrographs and soil moisture measurements were compared to model predictions. Stream flow prediction during non-winter periods generally agreed with measured flow resulting in an average r2 of 0·73, a standard error of 0·01 m3/s, and an average Nash-Sutcliffe efficiency R2 of 0·62. Soil moisture predictions showed trends similar to observations with errors on the order of the standard error of measurements. The model results were most accurate for non-winter conditions. The model is currently used for making management decisions for reducing non-point source pollution from manure spread fields in the Catskill watersheds which supply New York City's drinking water.

  10. Real-data Calibration Experiments On A Distributed Hydrologic Model

    NASA Astrophysics Data System (ADS)

    Brath, A.; Montanari, A.; Toth, E.

    The increasing availability of extended information on the study watersheds does not generally overcome the need for the determination through calibration of at least a part of the parameters of distributed hydrologic models. The complexity of such models, making the computations highly intensive, has often prevented an extensive analysis of calibration issues. The purpose of this study is an evaluation of the validation results of a series of automatic calibration experiments (using the shuffled complex evolu- tion method, Duan et al., 1992) performed with a highly conceptualised, continuously simulating, distributed hydrologic model applied on the real data of a mid-sized Ital- ian watershed. Major flood events occurred in the 1990-2000 decade are simulated with the parameters obtained by the calibration of the model against discharge data observed at the closure section of the watershed and the hydrological features (overall agreement, volumes, peaks and times to peak) of the discharges obtained both in the closure and in an interior stream-gauge are analysed for validation purposes. A first set of calibrations investigates the effect of the variability of the calibration periods, using the data from several single flood events and from longer, continuous periods. Another analysis regards the influence of rainfall input and it is carried out varying the size and distribution of the raingauge network, in order to examine the relation between the spatial pattern of observed rainfall and the variability of modelled runoff. Lastly, a comparison of the hydrographs obtained for the flood events with the model parameterisation resulting when modifying the objective function to be minimised in the automatic calibration procedure is presented.

  11. Data assimilation of GRACE terrestrial water storage estimates into a regional hydrological model of the Rhine River basin

    NASA Astrophysics Data System (ADS)

    Tangdamrongsub, N.; Steele-Dunne, S. C.; Gunter, B. C.; Ditmar, P. G.; Weerts, A. H.

    2015-04-01

    The ability to estimate terrestrial water storage (TWS) realistically is essential for understanding past hydrological events and predicting future changes in the hydrological cycle. Inadequacies in model physics, uncertainty in model land parameters, and uncertainties in meteorological data commonly limit the accuracy of hydrological models in simulating TWS. In an effort to improve model performance, this study investigated the benefits of assimilating TWS estimates derived from the Gravity Recovery and Climate Experiment (GRACE) data into the OpenStreams wflow_hbv model using an ensemble Kalman filter (EnKF) approach. The study area chosen was the Rhine River basin, which has both well-calibrated model parameters and high-quality forcing data that were used for experimentation and comparison. Four different case studies were examined which were designed to evaluate different levels of forcing data quality and resolution including those typical of other less well-monitored river basins. The results were validated using in situ groundwater (GW) and stream gauge data. The analysis showed a noticeable improvement in GW estimates when GRACE data were assimilated, with a best-case improvement of correlation coefficient from 0.31 to 0.53 and root mean square error (RMSE) from 8.4 to 5.4 cm compared to the reference (ensemble open-loop) case. For the data-sparse case, the best-case GW estimates increased the correlation coefficient from 0.46 to 0.61 and decreased the RMSE by 35%. For the average improvement of GW estimates (for all four cases), the correlation coefficient increases from 0.6 to 0.7 and the RMSE was reduced by 15%. Only a slight overall improvement was observed in streamflow estimates when GRACE data were assimilated. Further analysis suggested that this is likely due to sporadic short-term, but sizeable, errors in the forcing data and the lack of sufficient constraints on the soil moisture component. Overall, the results highlight the benefit of

  12. Exploring Information Theory for improving Hydrologic Model Performance

    NASA Astrophysics Data System (ADS)

    Martinez Baquero, G. F.; Gupta, H. V.

    2005-12-01

    For more than 30 years, Information Theory (IT) concepts have appeared in literature and practice of hydrology in several ways. Although these concepts are implicit in many practical applications and ideas, still the language and use are not widespread among the scientific community dedicated to study hydrologic processes. At the same time, new points of view, as the shown in this session, reflect the increasing availability of data and information with finer resolution. Equally, increasing computing capabilities, the development of more complex decision-making systems, and better forecasting tools impose on hydrologists new challenges related to the optimal use of data and the information that can be extracted from it. In our understanding, one of the approaches to address these challenges is to recognize that the notion of information is inherent to the problem of dealing with hydrologic data and the evaluation of its characteristics. The goal of this poster is to evaluate how IT can be used to generate a conceptual framework for assessing the performance of models against real data, and how these assessments can help us to increase our knowledge about the physical mechanisms involved.

  13. Global Hydrological Hazard Evaluation System (Global BTOP) Using Distributed Hydrological Model

    NASA Astrophysics Data System (ADS)

    Gusyev, M.; Magome, J.; Hasegawa, A.; Takeuchi, K.

    2015-12-01

    A global hydrological hazard evaluation system based on the BTOP models (Global BTOP) is introduced and quantifies flood and drought hazards with simulated river discharges globally for historical, near real-time monitoring and climate change impact studies. The BTOP model utilizes a modified topographic index concept and simulates rainfall-runoff processes including snowmelt, overland flow, soil moisture in the root and unsaturated zones, sub-surface flow, and river flow routing. The current global BTOP is constructed from global data on 10-min grid and is available to conduct river basin analysis on local, regional, and global scale. To reduce the impact of a coarse resolution, topographical features of global BTOP were obtained using river network upscaling algorithm that preserves fine resolution characteristics of 3-arcsec HydroSHEDS and 30-arcsec Hydro1K datasets. In addition, GLCC-IGBP land cover (USGS) and the DSMW(FAO) were used for the root zone depth and soil properties, respectively. The long-term seasonal potential evapotranspiration within BTOP model was estimated by the Shuttleworth-Wallace model using climate forcing data CRU TS3.1 and a GIMMS-NDVI(UMD/GLCF). The global BTOP was run with globally available precipitation such APHRODITE dataset and showed a good statistical performance compared to the global and local river discharge data in the major river basins. From these simulated daily river discharges at each grid, the flood peak discharges of selected return periods were obtained using the Gumbel distribution with L-moments and the hydrological drought hazard was quantified using standardized runoff index (SRI). For the dynamic (near real-time) applications, the global BTOP model is run with GSMaP-NRT global precipitation and simulated daily river discharges are utilized in a prototype near-real time discharge simulation system (GFAS-Streamflow), which is used to issue flood peak discharge alerts globally. The global BTOP system and GFAS

  14. How simple can a distributed hydrological model be?

    NASA Astrophysics Data System (ADS)

    Fenicia, Fabrizio; Kavetski, Dmitri; Savenije, Hubert H. G.; Pfister, Laurent

    2015-04-01

    It is well known that lumped conceptual models can often reproduce catchment streamflow response with about a 'handful' of model parameters. But what is the appropriate complexity of a distributed hydrological model, in order to reproduce the distinct streamflow response of heterogeneous internal subcatchments? Is the number of identifiable parameters proportional to the number of stream gauges? Into how many pieces should the catchment be broken-up? And which model structures are best suited to represent the behavior of particular landscape units? We investigated these questions in a case study based on the Attert basin in Luxembourg, where 10 subcatchments with clean and mixed geologies and land use manifested different rainfall-runoff behavior. The hydrological response of individual subcatchments was well represented using a range of lumped models with 4-8 parameters. We then attempted to simulate the 10 streamflow time series simultaneously, using a distributed model. Existing distributed models are often perceived to be over-parameterized. In order to avoid this problem, model development followed an iterative hypothesis-testing process. We developed, calibrated and compared alternative model variants, differing in the landscape classification approach, and in the structure of components intended to represent individual landscape elements. Decisions such as how to break-up the catchment, and which structure to assign to distinct landscape elements were found to significantly influence the model's predictive performance. In the present case, we determined that a geology-based landscape classification provided the best characterization of the observed differences in streamflow responses. In addition, we found that the individual geological units could be represented by remarkably simple model structures. The overall complexity of the distributed model was of about two 'handfuls' (10) of model parameters.

  15. Review of Hydrologic Models for Evaluating Use of Remote Sensing Capabilities

    NASA Technical Reports Server (NTRS)

    Peck, E. L.; Mcquivey, R. S.; Keefer, T.; Johnson, E. R.; Erekson, J. L.

    1982-01-01

    Hydrologic models most commonly used by federal agencies for hydrologic forecasting are reviewed. Six catchment models and one snow accumulation and ablation model are reviewed. Information on the structure, parameters, states, and required inputs is presented in schematic diagrams and in tables. The primary and secondary roles of parameters and state variables with respect to their function in the models are identified. The information will be used to evaluate the usefulness of remote sensing capabilities in the operational use of hydrologic models.

  16. Impact of wetlands mapping on parameterization of hydrologic simulation models

    NASA Astrophysics Data System (ADS)

    Viger, R.

    2015-12-01

    Wetlands and other surface depressions can impact hydrologic response within the landscape in a number of ways, such as intercepting runoff and near-surface flows or changing the potential for evaporation and seepage into the soil. The role of these features is increasingly being integrated into hydrological simulation models, such as the USGS Precipitation-Runoff Modeling System (PRMS) and the Soil Water Assessment Tool (SWAT), and applied to landscapes where wetlands are dominating features. Because the extent of these features varies widely through time, many modeling applications rely on delineations of the maximum possible extent to define total capacity of a model's spatial response unit. This poster presents an evaluation of several wetland map delineations for the Pipestem River basin in the North Dakota Prairie-pothole region. The featured data sets include the US Fish and Wildlife Service National Wetlands Inventory (NWI), surface water bodies extracted from the US Geological Survey National Hydrography Dataset (NHD), and elevation depressions extracted from 1 meter LiDAR data for the area. In addition to characterizing differences in the quality of these datasets, the poster will assess the impact of these differences when parameters are derived from them for the spatial response units of the PRMS model.

  17. Mid-Holocene hydrologic model of the Shingobee watershed, Minnesota

    USGS Publications Warehouse

    Filby, S.K.; Locke, Sharon M.; Person, M.A.; Winter, T.C.; Rosenberry, D.O.; Nieber, J.L.; Gutowski, W.J.; Ito, E.

    2002-01-01

    A hydrologifc model of the Shingobee Watershed in north-central Minnesota was developed to reconstruct mid-Holocene paleo-lake levels for Williams Lake, a surface-water body located in the southern portion of the watershed. Hydrologic parameters for the model were first estimated in a calibration exercise using a 9-yr historical record (1990-1998) of climatic and hydrologic stresses. The model reproduced observed temporal and spatial trends in surface/groundwater levels across the watershed. Mid-Holocene aquifer and lake levels were then reconstructed using two paleoclimatic data sets: CCM1 atmospheric general circulation model output and pollen-transfer functions using sediment core data from Williams Lake. Calculated paleo-lake levels based on pollen-derived paleoclimatic reconstructions indicated a 3.5-m drop in simulated lake levels and were in good agreement with the position of mid-Holocene beach sands observed in a Williams Lake sediment core transect. However, calculated paleolake levels based on CCM1 climate forcing produced only a 0.05-m drop in lake levels. We found that decreases in winter precipitation rather than temperature increases had the largest effect on simulated mid-Holocene lake levels. The study illustrates how watershed models can be used to critically evaluate paleoclimatic reconstructions by integrating geologic, climatic, limnologic, and hydrogeologic data sets. ?? 2002 University of Washington.

  18. Assimilating uncertain, dynamic and intermittent streamflow observations in hydrological models

    NASA Astrophysics Data System (ADS)

    Mazzoleni, Maurizio; Alfonso, Leonardo; Chacon-Hurtado, Juan; Solomatine, Dimitri

    2015-09-01

    Catastrophic floods cause significant socio-economical losses. Non-structural measures, such as real-time flood forecasting, can potentially reduce flood risk. To this end, data assimilation methods have been used to improve flood forecasts by integrating static ground observations, and in some cases also remote sensing observations, within water models. Current hydrologic and hydraulic research works consider assimilation of observations coming from traditional, static sensors. At the same time, low-cost, mobile sensors and mobile communication devices are becoming also increasingly available. The main goal and innovation of this study is to demonstrate the usefulness of assimilating uncertain streamflow observations that are dynamic in space and intermittent in time in the context of two different semi-distributed hydrological model structures. The developed method is applied to the Brue basin, where the dynamic observations are imitated by the synthetic observations of discharge. The results of this study show how model structures and sensors locations affect in different ways the assimilation of streamflow observations. In addition, it proves how assimilation of such uncertain observations from dynamic sensors can provide model improvements similar to those of streamflow observations coming from a non-optimal network of static physical sensors. This can be a potential application of recent efforts to build citizen observatories of water, which can make the citizens an active part in information capturing, evaluation and communication, helping simultaneously to improvement of model-based flood forecasting.

  19. Multi-variable calibration of a semi-distributed hydrological model using streamflow data and satellite-based evapotranspiration

    NASA Astrophysics Data System (ADS)

    Rientjes, T. H. M.; Muthuwatta, L. P.; Bos, M. G.; Booij, M. J.; Bhatti, H. A.

    2013-11-01

    A procedure is tested to complete energy balance based daily ETa series by MODIS data.The HVB model is calibrated on 2 water balance terms; ETa and stream flow (Q).HBV calibration on Q shows poor ETa results for inter-rainfall and recession periods.Multi-variable (MV) vs. single variable calibration showed best HBV performance.Large volume differences in Q and ETa do not essentially effect MV calibration.

  20. 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.

  1. 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.

  2. Modeling of subglacial hydrological development following rapid supraglacial lake drainage

    NASA Astrophysics Data System (ADS)

    Dow, C. F.; Kulessa, B.; Rutt, I. C.; Tsai, V. C.; Pimentel, S.; Doyle, S. H.; As, D.; Lindbäck, K.; Pettersson, R.; Jones, G. A.; Hubbard, A.

    2015-06-01

    The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and examine whether substantial, efficient subglacial channels can form during or following lake drainage events and their effect on the water pressure in the surrounding distributed system. We force the model with field data from a lake drainage site, 70 km from the terminus of Russell Glacier in West Greenland. The model outputs suggest that efficient subglacial channels do not readily form in the vicinity of the lake during rapid drainage and instead water is evacuated primarily by a transient turbulent sheet and the distributed system. Following lake drainage, channels grow but are not large enough to reduce the water pressure in the surrounding distributed system, unless preexisting channels are present throughout the domain. Our results have implications for the analysis of subglacial hydrological systems in regions where rapid lake drainage provides the primary mechanism for surface-to-bed connections.

  3. Modeling Vernal Pool Hydrology and Vegetation in the Sierra Nevadas

    NASA Astrophysics Data System (ADS)

    Montrone, A. K.; Saito, L.; Weisberg, P.; Gosejohan, M.

    2012-12-01

    Vernal pools are geographic depressions with relatively impermeable substrates that are subject to four distinct seasons in mountainous regions: they fill with snow in the winter, melt into inundated pools in the spring, become unsaturated and vegetated by summer, then dry and become fully desiccated by fall. Vernal pools in California are greatly threatened. Over 90% of the pools in California have been destroyed by urbanization and other land use changes and continue to disappear with population growth. Furthermore, these pools face threats posed by climate change due to altered precipitation and temperature regimes. In the context of anthropogenic climate change, we are evaluating the direct and indirect effects of grazing management on ecohydrology and plant community structure in vernal pools Northern Sierra Nevada mountains. Hydrologic models of vernal pool basins, driven by climatic variables, are used to 1) determine if a changing climate will alter the magnitude and spatial distribution of inundation period within the pools; 2) determine how the available habitat for vernal pool vegetation specialists will change with climate change; 3) determine if increased soil compaction due to cattle grazing can help mitigate effects of climate change resulting from changes in hydraulic conductivity; and 4) determine the importance of spatial resolution in constructing the physical representation of the pools within the hydrologic models. Preliminary results from the models including calibration error metrics and hydroperiod impacts of grazing for models with varying spatial complexity will be presented.

  4. Spatial interpolation schemes of daily precipitation for hydrologic modeling

    USGS Publications Warehouse

    Hwang, Y.; Clark, M.; Rajagopalan, B.; Leavesley, G.

    2012-01-01

    Distributed hydrologic models typically require spatial estimates of precipitation interpolated from sparsely located observational points to the specific grid points. We compare and contrast the performance of regression-based statistical methods for the spatial estimation of precipitation in two hydrologically different basins and confirmed that widely used regression-based estimation schemes fail to describe the realistic spatial variability of daily precipitation field. The methods assessed are: (1) inverse distance weighted average; (2) multiple linear regression (MLR); (3) climatological MLR; and (4) locally weighted polynomial regression (LWP). In order to improve the performance of the interpolations, the authors propose a two-step regression technique for effective daily precipitation estimation. In this simple two-step estimation process, precipitation occurrence is first generated via a logistic regression model before estimate the amount of precipitation separately on wet days. This process generated the precipitation occurrence, amount, and spatial correlation effectively. A distributed hydrologic model (PRMS) was used for the impact analysis in daily time step simulation. Multiple simulations suggested noticeable differences between the input alternatives generated by three different interpolation schemes. Differences are shown in overall simulation error against the observations, degree of explained variability, and seasonal volumes. Simulated streamflows also showed different characteristics in mean, maximum, minimum, and peak flows. Given the same parameter optimization technique, LWP input showed least streamflow error in Alapaha basin and CMLR input showed least error (still very close to LWP) in Animas basin. All of the two-step interpolation inputs resulted in lower streamflow error compared to the directly interpolated inputs. ?? 2011 Springer-Verlag.

  5. Considering complementary relationship of evaporation in Budyko's hydrological model

    NASA Astrophysics Data System (ADS)

    Han, Songjun; Shao, Weiwei

    2013-04-01

    In Budyko's hydrological model, actual evaporation was partitioned from precipitation as a function of the relative magnitude of precipitation and potential evaporation. In practice, both Penman equation and Priestley-Taylor equation have been used to estimate the potential evaporation with same Budyko curve, and they are not distinguished under Budyko framework. Nevertheless, according to the complementary relationship of evaporation, the definitions of Penman equation and Priestley-Taylor equation are absolutely different. When water availability is not limited, evaporation occurs at Priestley-Taylor's evaporation (Ew, referred to as wet environment evaporation). As the surface dries without changing the available energy, the actual and Penman's potential evaporation (Epen) rates depart from Ew with opposite changes in fluxes. So the question is: what is the difference of the Budyko's hydrological model with potential evaporation estimated by Penman or Priestley-Taylor equation? How to consider the complementary relationship in Budyko framework? In this study, for both long-term (multiyear) and annual values on water balances in the 29 non-humid catchments in the middle Yellow River Basin of China, the performances of Budyko's hydrological model with potential evaporation estimated by Epen and Ew were distinguished and compared. The catchments with larger value of Ep/Ew (ratio of Penman potential evaporation to Priestley-Taylor evaporation) are characterized with smaller evaporation ratios. The value of Ep/Ew can be served as another variable besides dryness index to partition actual evaporation from precipitation. With Priestley-Taylor equation as energy supply, an empirical formula for the parameter of the Budyko in terms of Ep/Ew and curve is proposed. Therefore, the complementary relationship of evaporation should be considered in the Budyko framework.

  6. 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.

  7. A conceptual data model coupling with physically-based distributed hydrological models based on catchment discretization schemas

    NASA Astrophysics Data System (ADS)

    Liu, Yuanming; Zhang, Wanchang; Zhang, Zhijie

    2015-11-01

    In hydrology, the data types, spatio-temporal scales and formats for physically-based distributed hydrological models and the distributed data or parameters may be different before significant data pre-processing or may change during hydrological simulation run time. A data model is devoted to these problems for sophisticated numerical hydrological modeling procedures. In this paper, we propose a conceptual data model to interpret the comprehensive, universal and complex water environmental entities. We also present an innovative integration methodology to couple the data model with physically-based distributed hydrological models (DHMs) based on catchment discretization schemas. The data model provides a reasonable framework for researchers of organizing and pre-processing water environmental spatio-temporal datasets. It also facilitates seamless data flow fluid and dynamic by hydrological response units (HRUs) as the core between the object-oriented databases and physically-based distributed hydrological models.

  8. Integrating water resources management in eco-hydrological modelling.

    PubMed

    Koch, H; Liersch, S; Hattermann, F F

    2013-01-01

    In this paper the integration of water resources management with regard to reservoir management in an eco-hydrological model is described. The model was designed to simulate different reservoir management options, such as optimized hydropower production, irrigation intake from the reservoir or optimized provisioning downstream. The integrated model can be used to investigate the impacts of climate variability/change on discharge or to study possible adaptation strategies in terms of reservoir management. The study area, the Upper Niger Basin located in the West African Sahel, is characterized by a monsoon-type climate. Rainfall and discharge regime are subject to strong seasonality. Measured data from a reservoir are used to show that the reservoir model and the integrated management options can be used to simulate the regulation of this reservoir. The inflow into the reservoir and the discharge downstream of the reservoir are quite distinctive, which points out the importance of the inclusion of water resources management.

  9. Simultaneous calibration of hydrological models in geographical space

    NASA Astrophysics Data System (ADS)

    Bárdossy, A.; Huang, Y.; Wagener, T.

    2015-10-01

    Hydrological models are usually calibrated for selected catchments individually using specific performance criteria. This procedure assumes that the catchments show individual behavior. As a consequence, the transfer of model parameters to other ungauged catchments is problematic. In this paper, the possibility of transferring part of the model parameters was investigated. Three different conceptual hydrological models were considered. The models were restructured by introducing a new parameter η which exclusively controls water balances. This parameter was considered as individual to each catchment. All other parameters, which mainly control the dynamics of the discharge (dynamical parameters), were considered for spatial transfer. Three hydrological models combined with three different performance measures were used in four different numerical experiments to investigate this transferability. The first numerical experiment, individual calibration of the models for 15 selected MOPEX catchments, showed that it is difficult to identify which catchments share common dynamical parameters. Parameters of one catchment might be good for another catchment but not reversed. In the second numerical experiment, a common spatial calibration strategy was used. It was explicitly assumed that the catchments share common dynamical parameters. This strategy leads to parameters which perform well on all catchments. A leave one out common calibration showed that in this case a good parameter transfer to ungauged catchments can be achieved. In the third numerical experiment, the common calibration methodology was applied for 96 catchments. Another set of 96 catchments were used to test the transfer of common dynamical parameters. The results show that even a large number of catchments share similar dynamical parameters. The performance is worse than those obtained by individual calibration, but the transfer to ungauged catchments remains possible. The performance of the common

  10. 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; 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

  11. Adaptable Web Modules to Stimulate Active Learning in Engineering Hydrology using Data and Model Simulations of Three Regional Hydrologic Systems

    NASA Astrophysics Data System (ADS)

    Habib, E. H.; Tarboton, D. G.; Lall, U.; Bodin, M.; Rahill-Marier, B.; Chimmula, S.; Meselhe, E. A.; Ali, A.; Williams, D.; Ma, Y.

    2013-12-01

    The hydrologic community has long recognized the need for broad reform in hydrologic education. A paradigm shift is critically sought in undergraduate hydrology and water resource education by adopting context-rich, student-centered, and active learning strategies. Hydrologists currently deal with intricate issues rooted in complex natural ecosystems containing a multitude of interconnected processes. Advances in the multi-disciplinary field include observational settings such as Critical Zone and Water, Sustainability and Climate Observatories, Hydrologic Information Systems, instrumentation and modeling methods. These research advances theory and practices call for similar efforts and improvements in hydrologic education. The typical, text-book based approach in hydrologic education has focused on specific applications and/or unit processes associated with the hydrologic cycle with idealizations, rather than the contextual relations in the physical processes and the spatial and temporal dynamics connecting climate and ecosystems. An appreciation of the natural variability of these processes will lead to graduates with the ability to develop independent learning skills and understanding. This appreciation cannot be gained in curricula where field components such as observational and experimental data are deficient. These types of data are also critical when using simulation models to create environments that support this type of learning. Additional sources of observations in conjunction with models and field data are key to students understanding of the challenges associated with using models to represent such complex systems. Recent advances in scientific visualization and web-based technologies provide new opportunities for the development of active learning techniques utilizing ongoing research. The overall goal of the current study is to develop visual, case-based, data and simulation driven learning experiences to instructors and students through a web

  12. Simultaneous Assimilation of Multiple Data into a Conceptual Rainfall-Runoff Model using Variational Methods for Hydrological Forecasting Applications

    NASA Astrophysics Data System (ADS)

    Schwanenberg, D.; Alvarado Montero, R.; Sensoy Sorman, A.; Krahe, P.

    2015-12-01

    Data assimilation methods applied to hydrological applications have primarily focused on assimilating streamflow and, more recently, soil moisture observations. Few cases actually assimilate both observations, and even fewer incorporate additional observations into the assimilation procedure. This is despite extensive developments in remote sensing information. Most research on data assimilation has focused on the implementation of sequential assimilation using Kalman filters. We present an alternative approach using variational methods based on Moving Horizon Estimation (MHE) to simultaneously assimilate streamflow data and remote sensing information obtained from the Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF) community, namely snow-covered area, snow water equivalent and soil moisture. This approach enables a highly flexible formulation of distance metrics for the introduction of noise into the model and the agreement between simulated and observed variables. The application of MHE on data assimilation is tested at two data-dense test sites in Germany and one data-sparse environment in Turkey. The assessment of results is based on the lead time performance of state variables of the conceptual rainfall-runoff model, i.e. not limited to the performance of streamflow forecast but also applicable to snow and soil moisture forecast skills. Results show a potential improvement on the performance of the forecasted streamflow when using a perfect time series of state variables generated through the simulation of the conceptual rainfall-runoff model HBV. The assimilation of H-SAF data, in combination with streamflow, reduces the performance of the forecasted streamflow compared to the assimilation using only streamflow data. However, other forecasted quantities such as the snow water equivalent or soil moisture are improved. Recommendations based on the test cases are given following the length of the assimilation

  13. Comprehensive Representation of Hydrologic and Geomorphic Process Coupling in Numerical Models: Internal Dynamics and Basin Evolution

    NASA Astrophysics Data System (ADS)

    Istanbulluoglu, E.; Vivoni, E. R.; Ivanov, V. Y.; Bras, R. L.

    2005-12-01

    Landscape morphology has an important control on the spatial and temporal organization of basin hydrologic response to climate forcing, affecting soil moisture redistribution as well as vegetation function. On the other hand, erosion, driven by hydrology and modulated by vegetation, produces landforms over geologic time scales that reflect characteristic signatures of the dominant land forming process. Responding to extreme climate events or anthropogenic disturbances of the land surface, infrequent but rapid forms of erosion (e.g., arroyo development, landsliding) can modify topography such that basin hydrology is significantly influenced. Despite significant advances in both hydrologic and geomorphic modeling over the past two decades, the dynamic interactions between basin hydrology, geomorphology and terrestrial ecology are not adequately captured in current model frameworks. In order to investigate hydrologic-geomorphic-ecologic interactions at the basin scale we present initial efforts in integrating the CHILD landscape evolution model (Tucker et al. 2001) with the tRIBS hydrology model (Ivanov et al. 2004), both developed in a common software environment. In this talk, we present preliminary results of the numerical modeling of the coupled evolution of basin hydro-geomorphic response and resulting landscape morphology in two sets of examples. First, we discuss the long-term evolution of both the hydrologic response and the resulting basin morphology from an initially uplifted plateau. In the second set of modeling experiments, we implement changes in climate and land-use to an existing topography and compare basin hydrologic response to the model results when landscape form is fixed (e.g. no coupling between hydrology and geomorphology). Model results stress the importance of internal basin dynamics, including runoff generation mechanisms and hydrologic states, in shaping hydrologic response as well as the importance of employing comprehensive

  14. Techniques to Access Databases and Integrate Data for Hydrologic Modeling

    SciTech Connect

    Whelan, Gene; Tenney, Nathan D.; Pelton, Mitchell A.; Coleman, Andre M.; Ward, Duane L.; Droppo, James G.; Meyer, Philip D.; Dorow, Kevin E.; Taira, Randal Y.

    2009-06-17

    This document addresses techniques to access and integrate data for defining site-specific conditions and behaviors associated with ground-water and surface-water radionuclide transport applicable to U.S. Nuclear Regulatory Commission reviews. Environmental models typically require input data from multiple internal and external sources that may include, but are not limited to, stream and rainfall gage data, meteorological data, hydrogeological data, habitat data, and biological data. These data may be retrieved from a variety of organizations (e.g., federal, state, and regional) and source types (e.g., HTTP, FTP, and databases). Available data sources relevant to hydrologic analyses for reactor licensing are identified and reviewed. The data sources described can be useful to define model inputs and parameters, including site features (e.g., watershed boundaries, stream locations, reservoirs, site topography), site properties (e.g., surface conditions, subsurface hydraulic properties, water quality), and site boundary conditions, input forcings, and extreme events (e.g., stream discharge, lake levels, precipitation, recharge, flood and drought characteristics). Available software tools for accessing established databases, retrieving the data, and integrating it with models were identified and reviewed. The emphasis in this review was on existing software products with minimal required modifications to enable their use with the FRAMES modeling framework. The ability of four of these tools to access and retrieve the identified data sources was reviewed. These four software tools were the Hydrologic Data Acquisition and Processing System (HDAPS), Integrated Water Resources Modeling System (IWRMS) External Data Harvester, Data for Environmental Modeling Environmental Data Download Tool (D4EM EDDT), and the FRAMES Internet Database Tools. The IWRMS External Data Harvester and the D4EM EDDT were identified as the most promising tools based on their ability to access and

  15. 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.

  16. A high-resolution European dataset for hydrologic modeling

    NASA Astrophysics Data System (ADS)

    Ntegeka, Victor; Salamon, Peter; Gomes, Goncalo; Sint, Hadewij; Lorini, Valerio; Thielen, Jutta

    2013-04-01

    There is an increasing demand for large scale hydrological models not only in the field of modeling the impact of climate change on water resources but also for disaster risk assessments and flood or drought early warning systems. These large scale models need to be calibrated and verified against large amounts of observations in order to judge their capabilities to predict the future. However, the creation of large scale datasets is challenging for it requires collection, harmonization, and quality checking of large amounts of observations. For this reason, only a limited number of such datasets exist. In this work, we present a pan European, high-resolution gridded dataset of meteorological observations (EFAS-Meteo) which was designed with the aim to drive a large scale hydrological model. Similar European and global gridded datasets already exist, such as the HadGHCND (Caesar et al., 2006), the JRC MARS-STAT database (van der Goot and Orlandi, 2003) and the E-OBS gridded dataset (Haylock et al., 2008). However, none of those provide similarly high spatial resolution and/or a complete set of variables to force a hydrologic model. EFAS-Meteo contains daily maps of precipitation, surface temperature (mean, minimum and maximum), wind speed and vapour pressure at a spatial grid resolution of 5 x 5 km for the time period 1 January 1990 - 31 December 2011. It furthermore contains calculated radiation, which is calculated by using a staggered approach depending on the availability of sunshine duration, cloud cover and minimum and maximum temperature, and evapotranspiration (potential evapotranspiration, bare soil and open water evapotranspiration). The potential evapotranspiration was calculated using the Penman-Monteith equation with the above-mentioned meteorological variables. The dataset was created as part of the development of the European Flood Awareness System (EFAS) and has been continuously updated throughout the last years. The dataset variables are used as

  17. Disentangling the uncertainty of hydrologic drought characteristics in a multi-model century-long experiment in continental river basins

    NASA Astrophysics Data System (ADS)

    Samaniego, Luis; Kumar, Rohini; Pechlivanidis, Illias; Breuer, Lutz; Wortmann, Michel; Vetter, Tobias; Flörke, Martina; Chamorro, Alejandro; Schäfer, David; Shah, Harsh; Zeng, Xiaofan

    2016-04-01

    The quantification of the predictive uncertainty in hydrologic models and their attribution to its main sources is of particular interest in climate change studies. In recent years, a number of studies have been aimed at assessing the ability of hydrologic models (HMs) to reproduce extreme hydrologic events. Disentangling the overall uncertainty of streamflow -including its derived low-flow characteristics- into individual contributions, stemming from forcings and model structure, has also been studied. Based on recent literature, it can be stated that there is a controversy with respect to which source is the largest (e.g., Teng, et al. 2012, Bosshard et al. 2013, Prudhomme et al. 2014). Very little has also been done to estimate the relative impact of the parametric uncertainty of the HMs with respect to overall uncertainty of low-flow characteristics. The ISI-MIP2 project provides a unique opportunity to understand the propagation of forcing and model structure uncertainties into century-long time series of drought characteristics. This project defines a consistent framework to deal with compatible initial conditions for the HMs and a set of standardized historical and future forcings. Moreover, the ensemble of hydrologic model predictions varies across a broad range of climate scenarios and regions. To achieve this goal, we use six preconditioned hydrologic models (HYPE or HBV, mHM, SWIM, VIC, and WaterGAP3) set up in seven large continental river basins: Amazon, Blue Nile, Ganges, Niger, Mississippi, Rhine, Yellow. These models are forced with bias-corrected outputs of five CMIP5 general circulation models (GCM) under four extreme representative concentration pathway (RCP) scenarios (i.e. 2.6, 4.5, 6.0, and 8.5 Wm-2) for the period 1971-2099. Simulated streamflow is transformed into a monthly runoff index (RI) to analyze the attribution of the GCM and HM uncertainty into drought magnitude and duration over time. Uncertainty contributions are investigated

  18. Disentangling the uncertainty of hydrologic drought characteristics in a multi-model century-long experiment in continental river basins

    NASA Astrophysics Data System (ADS)

    Samaniego, Luis; Kumar, Rohini; Pechlivanidis, Illias; Breuer, Lutz; Wortmann, Michel; Vetter, Tobias; Flörke, Martina; Chamorro, Alejandro; Schäfer, David; Shah, Harsh; Zeng, Xiaofan

    2016-04-01

    The quantification of the predictive uncertainty in hydrologic models and their attribution to its main sources is of particular interest in climate change studies. In recent years, a number of studies have been aimed at assessing the ability of hydrologic models (HMs) to reproduce extreme hydrologic events. Disentangling the overall uncertainty of streamflow -including its derived low-flow characteristics- into individual contributions, stemming from forcings and model structure, has also been studied. Based on recent literature, it can be stated that there is a controversy with respect to which source is the largest (e.g., Teng, et al. 2012, Bosshard et al. 2013, Prudhomme et al. 2014). Very little has also been done to estimate the relative impact of the parametric uncertainty of the HMs with respect to overall uncertainty of low-flow characteristics. The ISI-MIP2 project provides a unique opportunity to understand the propagation of forcing and model structure uncertainties into century-long time series of drought characteristics. This project defines a consistent framework to deal with compatible initial conditions for the HMs and a set of standardized historical and future forcings. Moreover, the ensemble of hydrologic model predictions varies across a broad range of climate scenarios and regions. To achieve this goal, we use six preconditioned hydrologic models (HYPE or HBV, mHM, SWIM, VIC, and WaterGAP3) set up in seven large continental river basins: Amazon, Blue Nile, Ganges, Niger, Mississippi, Rhine, Yellow. These models are forced with bias-corrected outputs of five CMIP5 general circulation models (GCM) under four extreme representative concentration pathway (RCP) scenarios (i.e. 2.6, 4.5, 6.0, and 8.5 Wm‑2) for the period 1971-2099. Simulated streamflow is transformed into a monthly runoff index (RI) to analyze the attribution of the GCM and HM uncertainty into drought magnitude and duration over time. Uncertainty contributions are investigated

  19. Modeling permafrost and hydrological cycle interactions in CESM

    NASA Astrophysics Data System (ADS)

    Swenson, S. C.; Lawrence, D. M.; Slater, A. G.; Lee, H.

    2012-12-01

    Permanently and seasonally frozen soils have a significant influence on energy, water, and carbon and nutrient cycling in high-latitude regions, and thus affect global climate as well. Observations of ground conditions in permafrost regions have shown rapid changes in some locations. Recent projections of permafrost extent made using the Community Earth System Model (CESM) indicate that if current emission levels are maintained, near-surface permafrost areas may be reduced to less than 30% of current values. Model development of CESM has resulted in steady improvements in its ability to reproduce observations of past and current frozen ground conditions. However, biases remain, most notably in the representation of the terrestrial hydrological cycle in high-latitude regions. Here we report on recent improvements to CESM cold-region hydrology, including the movement of water through frozen soils, active layer soil moisture, river discharge, wetlands, and flooding. We then examine the effects of these parameterization changes on projections of end-of-century permanently and seasonally frozen soils and provide a preliminary assessment of potential wetland distribution, river discharge, and soil moisture changes that could be anticipated if large-scale permafrost thaw occurs.

  20. 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.

  1. Advances in Modeling of Coupled Hydrologic-Socioeconomic Systems

    NASA Astrophysics Data System (ADS)

    Amadio, Mattia; Mysiak, Jaroslav; Pecora, Silvano; Agnetti, Alberto

    2013-04-01

    River flooding is the most common natural disaster in Europe, causing deaths and huge amount of economic losses. Disastrous flood events are often related to extreme meteorological conditions; therefore, climate change is expected to have an important influence over the intensity and frequency of major floods. While approximated large-scale assessments of flood risk scenarios have been carried out, the knowledge of the effects at smaller scales is poor or incomplete, with few localized studies. Also, the methods are still coarse and uneven. The approach of this study starts from the definition of the risk paradigm and the elaboration of local climatic scenarios to track a methodology aimed at elaborating and combining the three elements concurring to the determination of risk: hydrological hazard, value exposure and vulnerability. First, hydrological hazard scenarios are provided by hydrological and hydrodynamic models, used in to a flood forecasting system capable to define "what-if" scenario in a flexible way. These results are then integrated with land-use data (exposure) and depth-damage functions (vulnerability) in a GIS environment, to assess the final risk value (potential flood damage) and visualize it in form of risk maps. In this paper results from a pilot study in the Polesine area are presented, where four simulated levee breach scenarios are compared. The outcomes of the analysis may be instrumental to authorities to increase the knowledge of possible direct losses and guide decision making and planning processes also. As future perspective, the employed methodology can also be extended at the basin scale through integration with the existent flood warning system to gain a real-time estimate of floods direct costs.

  2. Inverse hydrological modelling of spatio-temporal rainfall patterns

    NASA Astrophysics Data System (ADS)

    Grundmann, Jens; Hörning, Sebastian; Bárdossy, András

    2016-04-01

    Distributed hydrological models are commonly used for simulating the non-linear response of a watershed to rainfall events for addressing different hydrological properties of the landscape. Such models are driven by spatial rainfall patterns for consecutive time steps, which are normally generated from point measurements using spatial interpolation methods. However, such methods fail in reproducing the true spatio-temporal rainfall patterns especially in data scarce regions with poorly gauged catchments or for highly dynamic, small scaled rainstorms which are not well recorded by existing monitoring networks. Consequently, uncertainties are associated with poorly identified spatio-temporal rainfall distribution in distributed rainfall-runoff-modelling since the amount of rainfall received by a catchment as well as the dynamics of the runoff generation of flood waves are underestimated. For addressing these challenges a novel methodology for inverse hydrological modelling is proposed using a Markov-Chain-Monte-Carlo framework. Thereby, potential candidates of spatio-temporal rainfall patterns are generated and selected according their ability to reproduce the observed surface runoff at the catchment outlet for a given transfer function in a best way. The Methodology combines the concept of random mixing of random spatial fields with a grid-based spatial distributed rainfall runoff model. The conditional target rainfall field is obtained as a linear combination of unconditional spatial random fields. The corresponding weights of the linear combination are selected such that the spatial variability of the rainfall amounts as well as the actual observed rainfall values are reproduced. The functionality of the methodology is demonstrated on a synthetic example. Thereby, the known spatio-temporal distribution of rainfall is reproduced for a given number of point observations of rainfall and the integral catchment response at the catchment outlet for a synthetic catchment

  3. European Continental Scale Hydrological Model, Limitations and Challenges

    NASA Astrophysics Data System (ADS)

    Rouholahnejad, E.; Abbaspour, K.

    2014-12-01

    The pressures on water resources due to increasing levels of societal demand, increasing conflict of interest and uncertainties with regard to freshwater availability create challenges for water managers and policymakers in many parts of Europe. At the same time, climate change adds a new level of pressure and uncertainty with regard to freshwater supplies. On the other hand, the small-scale sectoral structure of water management is now reaching its limits. The integrated management of water in basins requires a new level of consideration where water bodies are to be viewed in the context of the whole river system and managed as a unit within their basins. In this research we present the limitations and challenges of modelling the hydrology of the continent Europe. The challenges include: data availability at continental scale and the use of globally available data, streamgauge data quality and their misleading impacts on model calibration, calibration of large-scale distributed model, uncertainty quantification, and computation time. We describe how to avoid over parameterization in calibration process and introduce a parallel processing scheme to overcome high computation time. We used Soil and Water Assessment Tool (SWAT) program as an integrated hydrology and crop growth simulator to model water resources of the Europe continent. Different components of water resources are simulated and crop yield and water quality are considered at the Hydrological Response Unit (HRU) level. The water resources are quantified at subbasin level with monthly time intervals for the period of 1970-2006. The use of a large-scale, high-resolution water resources models enables consistent and comprehensive examination of integrated system behavior through physically-based, data-driven simulation and provides the overall picture of water resources temporal and spatial distribution across the continent. The calibrated model and results provide information support to the European Water

  4. 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.

  5. Modeling hydrological process in a glacier basin on the central Tibetan Plateau with a distributed hydrology soil vegetation model

    NASA Astrophysics Data System (ADS)

    Zhang, Guoshuai; Kang, Shichang; Cuo, Lan; Qu, Bin

    2016-08-01

    A mass and energy balance-based glacier melt module was coupled with the spatially distributed hydrological soil vegetation model and used to simulate the basin-scale water and energy balance in the Zhadang glacier basin. Observed hourly meteorological data from 2011 to 2014 were used as model forcing data. The basin-scale simulations were evaluated at both the point and areal scales using albedo, temperature, and height change on the glacier surface, as well as the mass balance and streamflow of the whole basin. The analysis showed that the model could effectively reproduce the key elements of the energy and mass balance of the Zhadang basin. The analysis demonstrates that radiation was the most important energy component accounting for 80% of total surface energy. On average, glacier runoff contributed to 64% of the total basin discharge during the study period. The overall streamflow was controlled by the glacier mass balance in 2012 and 2014, while temperature and precipitation affected hydrological processes the most during 2011 and 2013. Both high temperature and precipitation resulted in high total basin streamflow but via different mechanisms. High temperatures increase glacier mass loss and glacier melt runoff, whereas high precipitation decreases glacier melt runoff but produces high runoff in nonglacier areas. The early onset of the Indian monsoon with high snowfall reduces glacier surface melt but sustains basin discharge, positively affecting for water resources.

  6. Improving distributed hydrologic modeling and global land cover data

    NASA Astrophysics Data System (ADS)

    Broxton, Patrick

    Distributed models of the land surface are essential for global climate models because of the importance of land-atmosphere exchanges of water, energy, momentum. They are also used for high resolution hydrologic simulation because of the need to capture non-linear responses to spatially variable inputs. Continued improvements to these models, and the data which they use, is especially important given ongoing changes in climate and land cover. In hydrologic models, important aspects are sometimes neglected due to the need to simplify the models for operational simulation. For example, operational flash flood models do not consider the role of snow and are often lumped (i.e. do not discretize a watershed into multiple units, and so do not fully consider the effect of intense, localized rainstorms). To address this deficiency, an overland flow model is coupled with a subsurface flow model to create a distributed flash flood forecasting system that can simulate flash floods that involve rain on snow. The model is intended for operational use, and there are extensive algorithms to incorporate high-resolution hydrometeorologic data, to assist in the calibration of the models, and to run the model in real time. A second study, which is designed to improve snow simulation in forested environments, demonstrates the importance of explicitly representing a near canopy environment in snow models, instead of only representing open and canopy covered areas (i.e. with % canopy fraction), as is often done. Our modeling, which uses canopy structure information from Aerial Laser Survey Mapping at 1 meter resolution, suggests that areas near trees have more net snow water input than surrounding areas because of the lack of snow interception, shading by the trees, and the effects of wind. In addition, the greatest discrepancy between our model simulations that explicitly represent forest structure and those that do not occur in areas with more canopy edges. In addition, two value

  7. 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

  8. Modeling Climate Change Impacts on Landscape Evolution, Fire, and Hydrology

    NASA Astrophysics Data System (ADS)

    Sheppard, B. S.; O Connor, C.; Falk, D. A.; Garfin, G. M.

    2015-12-01

    Landscape disturbances such as wildfire interact with climate variability to influence hydrologic regimes. We coupled landscape, fire, and hydrologic models and forced them using projected climate to demonstrate climate change impacts anticipated at Fort Huachuca in southeastern Arizona, USA. The US Department of Defense (DoD) recognizes climate change as a trend that has implications for military installations, national security and global instability. The goal of this DoD Strategic Environmental Research and Development Program (SERDP) project (RC-2232) is to provide decision making tools for military installations in the southwestern US to help them adapt to the operational realities associated with climate change. For this study we coupled the spatially explicit fire and vegetation dynamics model FireBGCv2 with the Automated Geospatial Watershed Assessment tool (AGWA) to evaluate landscape vegetation change, fire disturbance, and surface runoff in response to projected climate forcing. A projected climate stream for the years 2005-2055 was developed from the Multivariate Adaptive Constructed Analogs (MACA) 4 km statistical downscaling of the CanESM2 GCM using Representative Concentration Pathway (RCP) 8.5. AGWA, an ArcGIS add-in tool, was used to automate the parameterization and execution of the Soil Water Assessment Tool (SWAT) and the KINematic runoff and EROSion2 (KINEROS2) models based on GIS layers. Landscape raster data generated by FireBGCv2 project an increase in fire and drought associated tree mortality and a decrease in vegetative basal area over the years of simulation. Preliminary results from SWAT modeling efforts show an increase to surface runoff during years following a fire, and for future winter rainy seasons. Initial results from KINEROS2 model runs show that peak runoff rates are expected to increase 10-100 fold as a result of intense rainfall falling on burned areas.

  9. Reduction of uncertainty of hydrological modelling using different precipitation inputs

    NASA Astrophysics Data System (ADS)

    Pluntke, T.; Pavlik, D.; Bernhofer, C.

    2012-04-01

    Precipitation is one of the main sources of uncertainty in hydrological modelling, due to its high temporal and spatial variability. A dense network of rain gauge stations or a combination with, e.g., radar data is needed to account for the - in comparison to other climatic elements - pronounced variability. The density of existing station-networks is low in many countries worldwide. Alternative approaches that use additional information should be applied to improve the estimation of areal precipitation. Within the project "International Research Alliance Saxony" (http://www.iwas-sachsen.ufz.de/), one subproject aims at a system analysis of a meso-scale catchment of the Western Bug in Ukraine. Effective and sustainable measures have to be identified to improve the water quality of the Western Bug under the premise of upcoming changes of climate, land use and socio economy. An exact quantification of the water balance is needed as a pre-requisite for a matter balance. This contribution demonstrates possibilities to reduce the uncertainties of water balance modelling of the catchment Kamianka-Buzka/ Western Bug (2560 km2) by applying and combining alternative precipitation inputs. Available precipitation data were undergone an extensive quality check and were bias corrected. The Soil and Water Assessment Tool (SWAT, http://swatmodel.tamu.edu/) was used for water balance modelling. By default, meteorological observations are incorporated into SWAT using the station that is nearest to the centroid of each sub-catchment. Two alternative precipitation inputs were applied: 1) Data of 20 stations were regionalized using kriging methods. 2) The output of the Regional Climate Model CCLM that was set up for the region was used. After a pre-calibration of the model, three models - having different precipitation inputs - were set up and calibrated independently applying the auto-calibration procedure Sequential Uncertainty Fitting (Abbaspour et al. 2004). The performance of the

  10. Radar altimetry assimilation in catchment-scale hydrological models

    NASA Astrophysics Data System (ADS)

    Bauer-Gottwein, P.; Michailovsky, C. I. B.

    2012-04-01

    Satellite-borne radar altimeters provide time series of river and lake levels with global coverage and moderate temporal resolution. Current missions can detect rivers down to a minimum width of about 100m, depending on local conditions around the virtual station. Water level time series from space-borne radar altimeters are an important source of information in ungauged or poorly gauged basins. However, many water resources management applications require information on river discharge. Water levels can be converted into river discharge by means of a rating curve, if sufficient and accurate information on channel geometry, slope and roughness is available. Alternatively, altimetric river levels can be assimilated into catchment-scale hydrological models. The updated models can subsequently be used to produce improved discharge estimates. In this study, a Muskingum routing model for a river network is updated using multiple radar altimetry time series. The routing model is forced with runoff produced by lumped-parameter rainfall-runoff models in each subcatchment. Runoff is uncertain because of errors in the precipitation forcing, structural errors in the rainfall-runoff model as well as uncertain rainfall-runoff model parameters. Altimetric measurements are translated into river reach storage based on river geometry. The Muskingum routing model is forced with a runoff ensemble and storages in the river reaches are updated using a Kalman filter approach. The approach is applied to the Zambezi and Brahmaputra river basins. Assimilation of radar altimetry significantly improves the capability of the models to simulate river discharge.

  11. 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

  12. Coupling Sediment Transport with the Integrated Hydrologic Model (PIHM)

    NASA Astrophysics Data System (ADS)

    Li, S.; Duffy, C. J.; Qu, Y.

    2006-12-01

    Penn State Integrated Hydrologic Model (PIHM) was developed by Qu and Duffy (2004) for multi-process simulation. As a further work, a physically-based non-equilibrium non-uniform sediment transport modeling component is developed and coupled with PIHM. It combines the hillslope and channel processes, and accounts for sediment yield as well as morphological evolution. For hillslope, the rain splash erosion, hydraulic erosion, and sediment transport by overland flow are simulated; for channel, it takes into account the hydraulic detachment and sediment transport by channel flow. An algorithm for bed armoring is proposed and incorporated in the component. And it also includes a river bank erosion submodel which is modified from Darby et al. (2002). The coupling system is solved using a semi-discrete finite volume approach. It is being tested based on three types of flow routing schemes: dynamic wave, diffusion wave and kinematic wave using different scales of watershed data.

  13. Ecological Acclimation and Hydrologic Response: Problem Complexity and Modeling Challenges

    NASA Astrophysics Data System (ADS)

    Kumar, P.; Srinivasan, V.; Le, P. V. V.; Drewry, D.

    2012-04-01

    Elevated CO2 in the atmosphere leads to a number of acclimatory responses in different vegetation types. These may be characterized as structural such as vegetation height or foliage density, ecophysiological such as reduction in stomatal conductance, and biochemical such as photosynthetic down-regulation. Furthermore, the allocation of assimilated carbon to different vegetation parts such as leaves, roots, stem and seeds is also altered such that empirical allometric relations are no longer valid. The extent and nature of these acclimatory responses vary between C3 and C4 vegetation and across species. These acclimatory responses have significant impact on hydrologic fluxes both pertaining to water and energy with the possibility of large-scale hydrologic influence. Capturing the pathways of acclimatory response to provide accurate ecohydrologic response predictions requires incorporating subtle relationships that are accentuated under elevated CO2. The talk will discuss the challenges of modeling these as well as applications to soybean, maize and bioenergy crops such as switchgrass and miscanthus.

  14. From spatially variable streamflow to distributed hydrological models: Analysis of key modeling decisions

    NASA Astrophysics Data System (ADS)

    Fenicia, Fabrizio; Kavetski, Dmitri; Savenije, Hubert H. G.; Pfister, Laurent

    2016-02-01

    This paper explores the development and application of distributed hydrological models, focusing on the key decisions of how to discretize the landscape, which model structures to use in each landscape element, and how to link model parameters across multiple landscape elements. The case study considers the Attert catchment in Luxembourg—a 300 km2 mesoscale catchment with 10 nested subcatchments that exhibit clearly different streamflow dynamics. The research questions are investigated using conceptual models applied at hydrologic response unit (HRU) scales (1-4 HRUs) on 6 hourly time steps. Multiple model structures are hypothesized and implemented using the SUPERFLEX framework. Following calibration, space/time model transferability is tested using a split-sample approach, with evaluation criteria including streamflow prediction error metrics and hydrological signatures. Our results suggest that: (1) models using geology-based HRUs are more robust and capture the spatial variability of streamflow time series and signatures better than models using topography-based HRUs; this finding supports the hypothesis that, in the Attert, geology exerts a stronger control than topography on streamflow generation, (2) streamflow dynamics of different HRUs can be represented using distinct and remarkably simple model structures, which can be interpreted in terms of the perceived dominant hydrologic processes in each geology type, and (3) the same maximum root zone storage can be used across the three dominant geological units with no loss in model transferability; this finding suggests that the partitioning of water between streamflow and evaporation in the study area is largely independent of geology and can be used to improve model parsimony. The modeling methodology introduced in this study is general and can be used to advance our broader understanding and prediction of hydrological behavior, including the landscape characteristics that control hydrologic response, the

  15. GIS embedded hydrological modeling: the SID&GRID project

    NASA Astrophysics Data System (ADS)

    Borsi, I.; Rossetto, R.; Schifani, C.

    2012-04-01

    The SID&GRID research project, started April 2010 and funded by Regione Toscana (Italy) under the POR FSE 2007-2013, aims to develop a Decision Support System (DSS) for water resource management and planning based on open source and public domain solutions. In order to quantitatively assess water availability in space and time and to support the planning decision processes, the SID&GRID solution consists of hydrological models (coupling 3D existing and newly developed surface- and ground-water and unsaturated zone modeling codes) embedded in a GIS interface, applications and library, where all the input and output data are managed by means of DataBase Management System (DBMS). A graphical user interface (GUI) to manage, analyze and run the SID&GRID hydrological models based on open source gvSIG GIS framework (Asociación gvSIG, 2011) and a Spatial Data Infrastructure to share and interoperate with distributed geographical data is being developed. Such a GUI is thought as a "master control panel" able to guide the user from pre-processing spatial and temporal data, running the hydrological models, and analyzing the outputs. To achieve the above-mentioned goals, the following codes have been selected and are being integrated: 1. Postgresql/PostGIS (PostGIS, 2011) for the Geo Data base Management System; 2. gvSIG with Sextante (Olaya, 2011) geo-algorithm library capabilities and Grass tools (GRASS Development Team, 2011) for the desktop GIS; 3. Geoserver and Geonetwork to share and discover spatial data on the web according to Open Geospatial Consortium; 4. new tools based on the Sextante GeoAlgorithm framework; 5. MODFLOW-2005 (Harbaugh, 2005) groundwater modeling code; 6. MODFLOW-LGR (Mehl and Hill 2005) for local grid refinement; 7. VSF (Thoms et al., 2006) for the variable saturated flow component; 8. new developed routines for overland flow; 9. new algorithms in Jython integrated in gvSIG to compute the net rainfall rate reaching the soil surface, as input for

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

    NASA Astrophysics Data System (ADS)

    Wińska, Małgorzata; 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.

  17. Dynamic hydrologic modeling using the zero-parameter Budyko model with instantaneous dryness index

    NASA Astrophysics Data System (ADS)

    Biswal, Basudev

    2016-09-01

    Long-term partitioning of hydrologic quantities is achieved by using the zero-parameter Budyko model which defines a dryness index. However, this approach is not suitable for dynamic partitioning particularly at diminishing timescales, and therefore, a universally applicable zero-parameter model remains elusive. Here an instantaneous dryness index is proposed which enables dynamic hydrologic modeling using the Budyko model. By introducing a "decay function" that characterizes the effects of antecedent rainfall and solar energy on the dryness state of a basin at a time, I propose the concept of instantaneous dryness index and use the Budyko function to perform continuous hydrologic partitioning. Using the same decay function, I then obtain discharge time series from the effective rainfall time series. The model is evaluated by considering data form 63 U.S. Geological Survey basins. Results indicate the possibility of using the proposed framework as an alternative platform for prediction in ungagued basins.

  18. Holistic versus monomeric strategies for hydrological modelling of modified hydrosystems

    NASA Astrophysics Data System (ADS)

    Nalbantis, I.; Efstratiadis, A.; Rozos, E.; Kopsiafti, M.; Koutsoyiannis, D.

    2010-10-01

    The modelling of modified basins that are inadequately measured constitutes a challenge for hydrological science. Often, models for such systems are detailed and hydraulics-based for only one part of the system while for other parts oversimplified models or rough assumptions are used. This is typically a bottom-up approach, which seeks to exploit knowledge of hydrological processes at the micro-scale at some components of the system. Also, it is a monomeric approach in two ways: first, essential interactions among system components may be poorly represented or even omitted; second, differences in the level of detail of process representation can lead to uncontrolled errors. Additionally, the calibration procedure merely accounts for the reproduction of the observed responses using typical fitting criteria. The paper aims to raise some critical issues, regarding the entire modelling approach for such hydrosystems. For this, two alternative modelling strategies are examined that reflect two modelling approaches or philosophies: a dominant bottom-up approach, which is also monomeric and very often, based on output information and a top-down and holistic approach based on generalized information. Critical options are examined, which codify the differences between the two strategies: the representation of surface, groundwater and water management processes, the schematization and parameterization concepts and the parameter estimation methodology. The first strategy is based on stand-alone models for surface and groundwater processes and for water management, which are employed sequentially. For each model, a different (detailed or coarse) parameterization is used, which is dictated by the hydrosystem schematization. The second strategy involves model integration for all processes, parsimonious parameterization and hybrid manual-automatic parameter optimization based on multiple objectives. A test case is examined in a hydrosystem in Greece with high complexities, such

  19. Toward Improved Simulation of Operations in Integrated Hydrologic Modeling

    NASA Astrophysics Data System (ADS)

    Morway, E. D.; Niswonger, R. G.; Triana, E.

    2015-12-01

    Conjunctive management of groundwater and surface water (GW-SW) resources has received increased attention as the gap between freshwater supply and demand widens in arid and semi-arid regions. The modeling tools used by water managers and government agencies, among others, for distributing the available freshwater supply among a complex set of competing demands in a 'prior appropriation' context, rely on loosely-coupled (or 'feed-forward') model applications that fail to achieve true convergence among values common to both codes. Commonly, models used for quantifying supply, that is, watershed and groundwater models, are run separately from river operations models that specialize in distributing a finite supply among a wide range of demands. As a result, it may be difficult to achieve a proper water balance among the respective codes, especially during drought conditions. Taking a step closer to a truly integrated environmental modeling framework for conjunctive management of GW-SW resources, the river operations model MODSIM has been integrated with the hydrologic model MODFLOW. MODSIM is a river basin management decision support system that simulates administration of water rights and (or) operational rules within river basins. MODFLOW is a physically-based distributed-parameter finite-difference model historically used for simulating groundwater systems, though the streamflow routing (SFR2) and lake (LAK) packages are capable of simulating surface water systems in hydraulic connection with the underlying alluvial aquifer. On their own, these two packages cannot simulate diversions and (or) releases from reservoirs, instead requiring users to specify these quantities prior to model execution. Through the MODSIM-MODFLOW integration, however, hydrologic processes are simulated simultaneously with dynamic river operations. In this way, solutions are synchronized before moving to the next time step. The newly developed code provides water planners and managers with a

  20. On the deterministic and stochastic use of hydrologic models

    NASA Astrophysics Data System (ADS)

    Farmer, William H.; Vogel, Richard M.

    2016-07-01

    Environmental simulation models, such as precipitation-runoff watershed models, are increasingly used in a deterministic manner for environmental and water resources design, planning, and management. In operational hydrology, simulated responses are now routinely used to plan, design, and manage a very wide class of water resource systems. However, all such models are calibrated to existing data sets and retain some residual error. This residual, typically unknown in practice, is often ignored, implicitly trusting simulated responses as if they are deterministic quantities. In general, ignoring the residuals will result in simulated responses with distributional properties that do not mimic those of the observed responses. This discrepancy has major implications for the operational use of environmental simulation models as is shown here. Both a simple linear model and a distributed-parameter precipitation-runoff model are used to document the expected bias in the distributional properties of simulated responses when the residuals are ignored. The systematic reintroduction of residuals into simulated responses in a manner that produces stochastic output is shown to improve the distributional properties of the simulated responses. Every effort should be made to understand the distributional behavior of simulation residuals and to use environmental simulation models in a stochastic manner.

  1. On the deterministic and stochastic use of hydrologic models

    USGS Publications Warehouse

    Farmer, William H.; Vogel, Richard M.

    2016-01-01

    Environmental simulation models, such as precipitation-runoff watershed models, are increasingly used in a deterministic manner for environmental and water resources design, planning, and management. In operational hydrology, simulated responses are now routinely used to plan, design, and manage a very wide class of water resource systems. However, all such models are calibrated to existing data sets and retain some residual error. This residual, typically unknown in practice, is often ignored, implicitly trusting simulated responses as if they are deterministic quantities. In general, ignoring the residuals will result in simulated responses with distributional properties that do not mimic those of the observed responses. This discrepancy has major implications for the operational use of environmental simulation models as is shown here. Both a simple linear model and a distributed-parameter precipitation-runoff model are used to document the expected bias in the distributional properties of simulated responses when the residuals are ignored. The systematic reintroduction of residuals into simulated responses in a manner that produces stochastic output is shown to improve the distributional properties of the simulated responses. Every effort should be made to understand the distributional behavior of simulation residuals and to use environmental simulation models in a stochastic manner.

  2. Multiobjective sensitivity analysis and optimization of distributed hydrologic model MOBIDIC

    NASA Astrophysics Data System (ADS)

    Yang, J.; Castelli, F.; Chen, Y.

    2014-10-01

    Calibration of distributed hydrologic models usually involves how to deal with the large number of distributed parameters and optimization problems with multiple but often conflicting objectives that arise in a natural fashion. This study presents a multiobjective sensitivity and optimization approach to handle these problems for the MOBIDIC (MOdello di Bilancio Idrologico DIstribuito e Continuo) distributed hydrologic model, which combines two sensitivity analysis techniques (the Morris method and the state-dependent parameter (SDP) method) with multiobjective optimization (MOO) approach ɛ-NSGAII (Non-dominated Sorting Genetic Algorithm-II). This approach was implemented to calibrate MOBIDIC with its application to the Davidson watershed, North Carolina, with three objective functions, i.e., the standardized root mean square error (SRMSE) of logarithmic transformed discharge, the water balance index, and the mean absolute error of the logarithmic transformed flow duration curve, and its results were compared with those of a single objective optimization (SOO) with the traditional Nelder-Mead simplex algorithm used in MOBIDIC by taking the objective function as the Euclidean norm of these three objectives. Results show that (1) the two sensitivity analysis techniques are effective and efficient for determining the sensitive processes and insensitive parameters: surface runoff and evaporation are very sensitive processes to all three objective functions, while groundwater recession and soil hydraulic conductivity are not sensitive and were excluded in the optimization. (2) Both MOO and SOO lead to acceptable simulations; e.g., for MOO, the average Nash-Sutcliffe value is 0.75 in the calibration period and 0.70 in the validation period. (3) Evaporation and surface runoff show similar importance for watershed water balance, while the contribution of baseflow can be ignored. (4) Compared to SOO, which was dependent on the initial starting location, MOO provides more

  3. Forensic isotope analysis to refine a hydrologic conceptual model.

    PubMed

    Bassett, R L; Steinwand, Aaron; Jorat, Saeed; Petersen, Christian; Jackson, Randy

    2008-01-01

    Water resources in the arid southwestern United States are frequently the subject of conflict from competing private and public interests. Legal remedies may remove impasses, but the technical analysis of the problem often determines the future success of legal solutions. In Owens Valley, California, the source of water for the Los Angeles Aqueduct (LAA) is flow diverted from the Owens River and its tributaries and ground water from valley aquifers. Future management of ground water delivered to the LAA needs technical support regarding quantity available, interconnection of shallow and confined aquifers, impact on local springs, and rate of recharge. Ground water flow models and ground water composition are tools already in use, but these have large uncertainty for local interpretations. This study conducted targeted sampling of springs and wells to evaluate the hydrologic system to corroborate conceptual and numerical models. The effort included measurement of intrinsic isotopic composition at key locations in the aquifers. The stable isotopic data of boron (delta(11)B), sulfur (delta(34)S), oxygen (delta(18)O), hydrogen (delta D), and tritium ((3)H) supported by basic chemical data provided rules for characterizing the upper and the lower aquifer system, confirmed the interpretation of ground water flow near faults and flow barriers, and detected hydraulic connections between the LAA and the perennial springs at key locations along the unlined reach of the LAA. This study exemplifies the use of forensic isotopic approaches as independent checks on the consistency of interpretations of conceptual models of a ground water system and the numerical hydrologic simulations.

  4. Limits and failures in hydrology: examples and lessons learned from three decades of process oriented hydrological modelling

    NASA Astrophysics Data System (ADS)

    Bronstert, Axel

    2016-04-01

    In hydrological sciences there have been rather many attempts to develop new mathematical analysis and modelling tools. Some (or even many?) of them failed or were at least only partially successful. Unfortunately, such nun-successful attempts are hardly reported on, because our common academic recognition is based on reports about success only. With all due respect to successful attempts, the scientific community could benefit a lot from reports of unsuccessful attempts or unexpected results. Therefore, in this contribution, the author presents examples of modelling failures from his own experiences during the last three decades. Emphasis is given on results obtained from process-oriented hydrological models, where the "right answer" was obtained "for the wrong reasons". Such example comprise, for instance, modelling infiltration experiments at the plot scale, modelling runoff generation from hillslope scale and in experimental catchments and modelling runoff from glaciated catchments It is explained how the "wrong reasons" could be identified and what was learned from such failures. It is argued that failures, which causes can be identified by the modeller or anybody else, could significantly contribute to a progress in hydrological system understanding or - at least - to the identification of research needs. Identification of causes of failure may even contribute more to scientific progress then brute force modelling of parameter sensitivity and uncertainty.

  5. A "total parameter estimation" method in the varification of distributed hydrological models

    NASA Astrophysics Data System (ADS)

    Wang, M.; Qin, D.; Wang, H.

    2011-12-01

    Conventionally hydrological models are used for runoff or flood forecasting, hence the determination of model parameters are common estimated based on discharge measurements at the catchment outlets. With the advancement in hydrological sciences and computer technology, distributed hydrological models based on the physical mechanism such as SWAT, MIKESHE, and WEP, have gradually become the mainstream models in hydrology sciences. However, the assessments of distributed hydrological models and model parameter determination still rely on runoff and occasionally, groundwater level measurements. It is essential in many countries, including China, to understand the local and regional water cycle: not only do we need to simulate the runoff generation process and for flood forecasting in wet areas, we also need to grasp the water cycle pathways and consumption process of transformation in arid and semi-arid regions for the conservation and integrated water resources management. As distributed hydrological model can simulate physical processes within a catchment, we can get a more realistic representation of the actual water cycle within the simulation model. Runoff is the combined result of various hydrological processes, using runoff for parameter estimation alone is inherits problematic and difficult to assess the accuracy. In particular, in the arid areas, such as the Haihe River Basin in China, runoff accounted for only 17% of the rainfall, and very concentrated during the rainy season from June to August each year. During other months, many of the perennial rivers within the river basin dry up. Thus using single runoff simulation does not fully utilize the distributed hydrological model in arid and semi-arid regions. This paper proposed a "total parameter estimation" method to verify the distributed hydrological models within various water cycle processes, including runoff, evapotranspiration, groundwater, and soil water; and apply it to the Haihe river basin in

  6. Hydrologic predictions on ungauged catchments using deterministic distributed modelling system

    NASA Astrophysics Data System (ADS)

    Tachecí, Pavel; Kimlová, Martina

    2010-05-01

    There is a need for warning system giving prediction of flash-flood risk conditions with sufficient advance even in source areas and in small tributaries catchments. New approach is based on combination of numerical weather prediction (NWP) model, radar or rain gauge data with distributed hydrologic mathematical model of particular area. Set of newly developed tools, customized for particular use in the Czech Hydrometeorological Institute (CHMI) environment enhance import of data and presentation of results. This forecast system focuses on hydrological modelling of running water balance in spatially distributed manner. Its computation is repeated day-to-day. Six models of particular basins (800 - 4000 km2), representing different conditions across the Czech Republic territory were calibrated and validated successfully. The Sázava river basin model (4.000 km2) is used for regular testing operation in CHMI Forecast centre since October 2007. Basic size of grid cells used in models is 300x300 m, basic time step of forecast is 1 day, but can be refined according to the input data. Water balance is computed using simplified 2-layer method for unsaturated zone, 2D approximation of Boussinesq equation for saturated zone, diffusion equation for overland flow and 1D kinematic equation for river flow (MIKE 11 model). The whole process of input data processing, model simulation and result generation may be run automatically or in step-by step mode via simple graphical user interface. Three types of input data are supported: •time series (temperature and precipitation) measured at observation stations and stored in CHMI database •radar data products (precipitation intensity field) •results of ALADIN weather forecast model (temperature and precipitation field). For forecast purposes, reference evapotranspiration is approximated according relationship to air temperature for every computational grid cell. The user may choose area (catchment) to be processed and period of

  7. Calibration of hydrological models using flow-duration curves

    NASA Astrophysics Data System (ADS)

    Westerberg, I. K.; Guerrero, J.-L.; Younger, P. M.; Beven, K. J.; Seibert, J.; Halldin, S.; Freer, J. E.; Xu, C.-Y.

    2011-07-01

    The degree of belief we have in predictions from hydrologic models will normally depend on how well they can reproduce observations. Calibrations with traditional performance measures, such as the Nash-Sutcliffe model efficiency, are challenged by problems including: (1) uncertain discharge data, (2) variable sensitivity of different performance measures to different flow magnitudes, (3) influence of unknown input/output errors and (4) inability to evaluate model performance when observation time periods for discharge and model input data do not overlap. This paper explores a calibration method using flow-duration curves (FDCs) to address these problems. The method focuses on reproducing the observed discharge frequency distribution rather than the exact hydrograph. It consists of applying limits of acceptability for selected evaluation points (EPs) on the observed uncertain FDC in the extended GLUE approach. Two ways of selecting the EPs were tested - based on equal intervals of discharge and of volume of water. The method was tested and compared to a calibration using the traditional model efficiency for the daily four-parameter WASMOD model in the Paso La Ceiba catchment in Honduras and for Dynamic TOPMODEL evaluated at an hourly time scale for the Brue catchment in Great Britain. The volume method of selecting EPs gave the best results in both catchments with better calibrated slow flow, recession and evaporation than the other criteria. Observed and simulated time series of uncertain discharges agreed better for this method both in calibration and prediction in both catchments. An advantage with the method is that the rejection criterion is based on an estimation of the uncertainty in discharge data and that the EPs of the FDC can be chosen to reflect the aims of the modelling application, e.g. using more/less EPs at high/low flows. While the method appears less sensitive to epistemic input/output errors than previous use of limits of acceptability applied

  8. Calibration of hydrological models using flow-duration curves

    NASA Astrophysics Data System (ADS)

    Westerberg, I. K.; Guerrero, J.-L.; Younger, P. M.; Beven, K. J.; Seibert, J.; Halldin, S.; Freer, J. E.; Xu, C.-Y.

    2010-12-01

    The degree of belief we have in predictions from hydrologic models depends on how well they can reproduce observations. Calibrations with traditional performance measures such as the Nash-Sutcliffe model efficiency are challenged by problems including: (1) uncertain discharge data, (2) variable importance of the performance with flow magnitudes, (3) influence of unknown input/output errors and (4) inability to evaluate model performance when observation time periods for discharge and model input data do not overlap. A new calibration method using flow-duration curves (FDCs) was developed which addresses these problems. The method focuses on reproducing the observed discharge frequency distribution rather than the exact hydrograph. It consists of applying limits of acceptability for selected evaluation points (EPs) of the observed uncertain FDC in the extended GLUE approach. Two ways of selecting the EPs were tested - based on equal intervals of discharge and of volume of water. The method was tested and compared to a calibration using the traditional model efficiency for the daily four-parameter WASMOD model in the Paso La Ceiba catchment in Honduras and for Dynamic TOPMODEL evaluated at an hourly time scale for the Brue catchment in Great Britain. The volume method of selecting EPs gave the best results in both catchments with better calibrated slow flow, recession and evaporation than the other criteria. Observed and simulated time series of uncertain discharges agreed better for this method both in calibration and prediction in both catchments without resulting in overpredicted simulated uncertainty. An advantage with the method is that the rejection criterion is based on an estimation of the uncertainty in discharge data and that the EPs of the FDC can be chosen to reflect the aims of the modelling application e.g. using more/less EPs at high/low flows. While the new method is less sensitive to epistemic input/output errors than the normal use of limits of

  9. Feedback Loop of Data Infilling Using Model Result of Actual Evapotranspiration from Satellites and Hydrological Model

    NASA Astrophysics Data System (ADS)

    Murdi Hartanto, Isnaeni; Alexandridis, Thomas K.; van Andel, Schalk Jan; Solomatine, Dimitri

    2014-05-01

    Using satellite data in a hydrological model has long been occurring in modelling of hydrological processes, as a source of low cost regular data. The methods range from using satellite products as direct input, model validation, and data assimilation. However, the satellite data frequently face the missing value problem, whether due to the cloud cover or the limited temporal coverage. The problem could seriously affect its usefulness in hydrological model, especially if the model uses it as direct input, so data infilling becomes one of the important parts in the whole modelling exercise. In this research, actual evapotranspiration product from satellite is directly used as input into a spatially distributed hydrological model, and validated by comparing the catchment's end discharge with measured data. The instantaneous actual evapotranspiration is estimated from MODIS satellite images using a variation of the energy balance model for land (SEBAL). The eight-day cumulative actual evapotranspiration is then obtained by a temporal integration that uses the reference evapotranspiration calculated from meteorological data [1]. However, the above method cannot fill in a cell if the cell is constantly having no-data value during the eight-day periods. The hydrological model requires full set of data without no-data cells, hence, the no-data cells in the satellite's evapotranspiration map need to be filled in. In order to fills the no-data cells, an output of hydrological model is used. The hydrological model is firstly run with reference evapotranspiration as input to calculate discharge and actual evapotranspiration. The no-data cells in the eight-day cumulative map from the satellite are then filled in with the output of the first run of hydrological model. The final data is then used as input in a hydrological model to calculate discharge, thus creating a loop. The method is applied in the case study of Rijnland, the Netherlands where in the winter, cloud cover is

  10. An eco-hydrologic model of malaria outbreaks

    NASA Astrophysics Data System (ADS)

    Montosi, E.; Manzoni, S.; Porporato, A.; Montanari, A.

    2012-03-01

    Malaria is a geographically widespread infectious disease that is well known to be affected by climate variability at both seasonal and interannual timescales. In an effort to identify climatic factors that impact malaria dynamics, there has been considerable research focused on the development of appropriate disease models for malaria transmission and their consideration alongside climatic datasets. These analyses have focused largely on variation in temperature and rainfall as direct climatic drivers of malaria dynamics. Here, we further these efforts by considering additionally the role that soil water content may play in driving malaria incidence. Specifically, we hypothesize that hydro-climatic variability should be an important factor in controlling the availability of mosquito habitats, thereby governing mosquito growth rates. To test this hypothesis, we reduce a nonlinear eco-hydrologic model to a simple linear model through a series of consecutive assumptions and apply this model to malaria incidence data from three South African provinces. Despite the assumptions made in the reduction of the model, we show that soil water content can account for a significant portion of malaria's case variability beyond its seasonal patterns, whereas neither temperature nor rainfall alone can do so. Future work should therefore consider soil water content as a simple and computable variable for incorporation into climate-driven disease models of malaria and other vector-borne infectious diseases.

  11. 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.

  12. Plug-and-Play Hydrologic Modeling: Is That Really Possible?

    NASA Astrophysics Data System (ADS)

    Peckham, S. D.

    2012-12-01

    The vision of a community of modelers that shares reusable and well-tested process components that can easily be linked together to create new models is very appealing. In this vision, trying a new method for modeling a physical process, comparing two methods from different groups or coupling two models together to do something new is painless and straightforward. Scientists get to spend more time on understanding the natural world, making predictions and analyzing model results. Students quickly learn how different approaches differ and how sensitive models are to various input parameters. They begin to understand how the whole system works instead of just one part of it. Believe it or not, this vision is on the verge of becoming a reality but we aren't quite there yet. In order for the hydrologic modeling community to achieve this vision and work together in this way it isn't necessary for us to drastically change the way we do things. However, we do need to agree on some minimum set of standards and these have mostly to do with providing standardized metadata decriptions of our models and our data sets. We already have great software tools for accommodating differences between models that allow them to be coupled and work together. These include tools for spatial regridding, time interpolation, unit conversion, format conversion and even computer language interoperability. But in order to write software that automatically invokes these tools when needed, we need standardized machine and human-readable metadata descriptions of our models and data sets. The purpose of this talk is to review some of the technical problems that have already been solved, including the tools mentioned above, and then explain why we need standardized metadata in order to achieve the vision of seamless model integration. A new standard called the CSDMS Standard Names that is being developed for the Community Surface Dynamics Modeling System (CSDMS) project to address this problem will

  13. Hydrologic modeling of two glaciated watersheds in Northeast Pennsylvania

    USGS Publications Warehouse

    Srinivasan, M.S.; Hamlett, J.M.; Day, R.L.; Sams, J.I.; Petersen, G.W.

    1998-01-01

    A hydrologic modeling study, using the Hydrologic Simulation Program - FORTRAN (HSPF), was conducted in two glaciated watersheds, Purdy Creek and Ariel Creek in northeastern Pennsylvania. Both watersheds have wetlands and poorly drained soils due to low hydraulic conductivity and presence of fragipans. The HSPF model was calibrated in the Purdy Creek watershed and verified in the Ariel Creek watershed for June 1992 to December 1993 period. In Purdy Creek, the total volume of observed streamflow during the entire simulation period was 13.36 x 106 m3 and the simulated streamflow volume was 13.82 x 106 m3 (5 percent difference). For the verification simulation in Ariel Creek, the difference between the total observed and simulated flow volumes was 17 percent. Simulated peak flow discharges were within two hours of the observed for 30 of 46 peak flow events (discharge greater than 0.1 m3/sec) in Purdy Creek and 27 of 53 events in Ariel Creek. For 22 of the 46 events in Purdy Creek and 24 of 53 in Ariel Creek, the differences between the observed and simulated peak discharge rates were less than 30 percent. These 22 events accounted for 63 percent of total volume of streamflow observed during the selected 46 peak flow events in Purdy Creek. In Ariel Creek, these 24 peak flow events accounted for 62 percent of the total flow observed during all peak flow events. Differences in observed and simulated peak flow rates and volumes (on a percent basis) were greater during the snowmelt runoff events and summer periods than for other times.A hydrologic modeling study, using the Hydrologic Simulation Program - FORTRAN (HSPF), was conducted in two glaciated watersheds, Purdy Creek and Ariel Creek in northeastern Pennsylvania. Both watersheds have wetlands and poorly drained soils due to low hydraulic conductivity and presence of fragipans. The HSPF model was calibrated in the Purdy Creek watershed and verified in the Ariel Creek watershed for June 1992 to December 1993 period. In

  14. An attempt of ensemble modelling of future hydrological regime for selected river basin.

    NASA Astrophysics Data System (ADS)

    Valainis, A.; Timuhin, A.; Bethers, U.

    2009-04-01

    Ensemble modelling of hydrological regime may refer to usage of different Regional Climate Models (RCMs) coupled with one hydrological model, or usage of one RCM coupled with multiple hydrological models. Our goal was to examine future flow regimes based on different hydrological models. We conducted a river basin study based on one particular subbasin (Berze) of the river Lielupe basin. Lielupe is a lowland river with basin area of 17000 sq.km, situated in Latvia and Lithuania. Area of chosen subbasin is approximately 1000 sq.km. Ensemble of hydrological models consisted of MIKE SHE, and MIKE BASIN by DHI, the runoff model embedded in RCM, and in-house FiBasin model. MIKE SHE is grid based distributed hydrological model coupled with MIKE 11 flow routing model. MIKE Basin has embedded, conceptual catchment based NAM model. FiBasin is spatially distributed, finite volume based hydrological model with hydraulic routing network. The RCM and climate change scenarios are provided by Prediction of Regional scenarios and Uncertainties for Defining European Climate change risks and Effects (PRUDENCE) project. Time period for climate change scenarios is 2071-2100. The different responses from climate change, using different calibration sets where evaluated. The uncertainty related to choice of hydrological models is evaluated. It is found that the choice of hydrological model can lead to uncertainty witch is comparable with the even to difference between the climate scenarios, or the climate change itself. This conclusion is valid for the area of study in which the expected change of the hydrological regime is rather small.

  15. Evaluating prospective hydrological model improvements with consideration of data and model uncertainty

    NASA Astrophysics Data System (ADS)

    Craig, James; Sgro, Nicholas; Tolson, Bryan

    2016-04-01

    New algorithms for simulating hydrological processes are regularly proposed in the hydrological literature. These algorithms are often promoted as being more physically-based or better at capturing hydrologic phenomenon seen in the field. However, the tests used to evaluate the effectiveness of these algorithms are typically no more than history matching - an improved model hydrograph is (often inappropriately) interpreted as an improved model. Here, a simple and more stringent method is proposed for comparing two model algorithms in terms of their ability to provide distinguishably different validation results under the impact of uncertainty in observation data and forcings. A key output of the test is whether results from two model configurations are fundamentally differentiable. This test can be used both to support improved algorithm development, but also to aid in hypothesis testing about watershed functioning or to support model selection. As may be expected, our ability to identify the preferred hydrologic algorithm is significantly diminished when model/data uncertainty is incorporated into the evaluation process. The information content of the data and compensatory parameter effects play a key role in our ability to distinguish one model algorithm from another, and the results suggest that simpler models justified by the available data may have more utility than complex physically-based models which can fit the data at the cost of poor validation performance. They also suggest that finding the "best" model structure is (unsurprisingly) dependent upon both the quality and information content of the available observation data.

  16. Parameterization of a hydrological model using remote sensing data

    NASA Astrophysics Data System (ADS)

    Oppelt, N.; Rathjens, H.; Müller, T.-L.

    2012-04-01

    The alteration of land cover by humans has multiple consequences on biological systems ranging from local to global scales. The United Nations have rated land use changes as one of the major issues for the coming centuries. In Northern Germany a significant land use change can be observed since 2004, i.e. the amendment of the Renewable Energies Act. Since then, an increasing number of biogas plants have been built resulting in an increased cultivation of so-called energy crops, especially in direct neighbourhood to these plants. Conversion of land is known to alter hydrological processes such as the exchange of energy and water. To investigate the effects of land use change on the water cycle in lowland river catchments in Northern Germany, we used a series of land cover data for the Upper Stoer, a sub-catchment of the river Elbe, as the input for a hydrological model. To derive the land cover data, we applied maximum-likelihood classifications of Landsat TM data for the years 2003 and 2010. The open source model suite SWAT (Soil Water Assessment Tool) was used to model the water cycle. SWAT has proven to be a useful tool for simulating the effect of watershed processes and management practices on water resources. A comparison of the modelled and observed discharge at the outlet of the catchment (gauge Willenscharen) showed good results (Nash Sutcliffe = 0.62). However, the land use change had no measurable effect on the discharge at the outlet due to the masking influence of high groundwater levels in the catchment. Therefore focusing on the discharge at the outlet is not a suitable approach in such cases. To represent the spatial characteristics of a catchment as realistically as possible, the catchment area must be spatially discretized. The configuration used primarily within SWAT is the sub-watershed discretization scheme. This results in a loss of spatial information, which is problematic for our intended applications. Therefore we developed an alternative

  17. 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

  18. 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

  19. HBV genotypic variability in Cuba.

    PubMed

    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.

  20. Hydrologic Setting and Conceptual Hydrologic Model of the Walker River Basin, West-Central Nevada

    USGS Publications Warehouse

    Lopes, Thomas J.; Allander, Kip K.

    2009-01-01

    The Walker River is the main source of inflow to Walker Lake, a closed-basin lake in west-central Nevada. Between 1882 and 2008, agricultural diversions resulted in a lake-level decline of more than 150 feet and storage loss of 7,400,000 acre-ft. Evaporative concentration increased dissolved solids from 2,500 to 17,000 milligrams per liter. The increase in salinity threatens the survival of the Lahontan cutthroat trout, a native species listed as threatened under the Endangered Species Act. This report describes the hydrologic setting of the Walker River basin and a conceptual hydrologic model of the relations among streams, groundwater, and Walker Lake with emphasis on the lower Walker River basin from Wabuska to Hawthorne, Nevada. The Walker River basin is about 3,950 square miles and straddles the California-Nevada border. Most streamflow originates as snowmelt in the Sierra Nevada. Spring runoff from the Sierra Nevada typically reaches its peak during late May to early June with as much as 2,800 cubic feet per second in the Walker River near Wabuska. Typically, 3 to 4 consecutive years of below average streamflow are followed by 1 or 2 years of average or above average streamflow. Mountain ranges are comprised of consolidated rocks with low hydraulic conductivities, but consolidated rocks transmit water where fractured. Unconsolidated sediments include fluvial deposits along the active channel of the Walker River, valley floors, alluvial slopes, and a playa. Sand and gravel deposited by the Walker River likely are discontinuous strata throughout the valley floor. Thick clay strata likely were deposited in Pleistocene Lake Lahontan and are horizontally continuous, except where strata have been eroded by the Walker River. At Walker Lake, sediments mostly are clay interbedded with alluvial slope, fluvial, and deltaic deposits along the lake margins. Coarse sediments form a multilayered, confined-aquifer system that could extend several miles from the shoreline

  1. HYDROLOGIC MODEL UNCERTAINTY ASSOCIATED WITH SIMULATING FUTURE LAND-COVER/USE SCENARIOS: A RETROSPECTIVE ANALYSIS

    EPA Science Inventory

    GIS-based hydrologic modeling offers a convenient means of assessing the impacts associated with land-cover/use change for environmental planning efforts. Alternative future scenarios can be used as input to hydrologic models and compared with existing conditions to evaluate pot...

  2. Stimulation from Simulation? A Teaching Model of Hillslope Hydrology for Use on Microcomputers.

    ERIC Educational Resources Information Center

    Burt, Tim; Butcher, Dave

    1986-01-01

    The design and use of a simple computer model which simulates a hillslope hydrology is described in a teaching context. The model shows a relatively complex environmental system can be constructed on the basis of a simple but realistic theory, thus allowing students to simulate the hydrological response of real hillslopes. (Author/TRS)

  3. 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}...

  4. Predicting hydrological signatures in ungauged catchments using spatial interpolation, index model, and rainfall-runoff modelling

    NASA Astrophysics Data System (ADS)

    Zhang, Yongqiang; Vaze, Jai; Chiew, Francis H. S.; Teng, Jin; Li, Ming

    2014-09-01

    Understanding a catchment's behaviours in terms of its underlying hydrological signatures is a fundamental task in surface water hydrology. It can help in water resource management, catchment classification, and prediction of runoff time series. This study investigated three approaches for predicting six hydrological signatures in southeastern Australia. These approaches were (1) spatial interpolation with three weighting schemes, (2) index model that estimates hydrological signatures using catchment characteristics, and (3) classical rainfall-runoff modelling. The six hydrological signatures fell into two categories: (1) long-term aggregated signatures - annual runoff coefficient, mean of log-transformed daily runoff, and zero flow ratio, and (2) signatures obtained from daily flow metrics - concavity index, seasonality ratio of runoff, and standard deviation of log-transformed daily flow. A total of 228 unregulated catchments were selected, with half the catchments randomly selected as gauged (or donors) for model building and the rest considered as ungauged (or receivers) to evaluate performance of the three approaches. The results showed that for two long-term aggregated signatures - the log-transformed daily runoff and runoff coefficient, the index model and rainfall-runoff modelling performed similarly, and were better than the spatial interpolation methods. For the zero flow ratio, the index model was best and the rainfall-runoff modelling performed worst. The other three signatures, derived from daily flow metrics and considered to be salient flow characteristics, were best predicted by the spatial interpolation methods of inverse distance weighting (IDW) and kriging. Comparison of flow duration curves predicted by the three approaches showed that the IDW method was best. The results found here provide guidelines for choosing the most appropriate approach for predicting hydrological behaviours at large scales.

  5. Modeling Hydrological Processes with a Fully-Coupled Atmospheric-Hydrological Modeling System for the Poyang Lake Basin, China

    NASA Astrophysics Data System (ADS)

    Wagner, S.; Fersch, B.; Yu, Z.; Yuan, F.; Kunstmann, H.

    2015-12-01

    For a rational quantification of past, current and future water availability, the feedback mechanisms among atmosphere, land surface and subsurface play a crucial role. Investigations of these feedback mechanisms require coupled atmospheric-hydrological modeling systems. Investigations of climate and land use changes on the regional water balance require model systems, which describe the feedback mechanisms between groundwater-, soil moisture dynamics and precipitation and which allow long-term simulations for climate-relevant scales. We have developed such a fully-coupled, meso-scale modeling system extending the atmospheric model WRF-ARW with the hydrological model HMS, which includes lateral water fluxes at the land surface and subsurface. In addition, two-way interaction between the saturated and the unsaturated zone is implemented by replacing the free drainage bottom boundary of the Noah Land Surface Model (LSM) with two approaches, a Fixed-head boundary condition assuming an equilibrium soil moisture distribution or a Darcy-flux at the boundary assuming a quasi-steady-state moisture profile below the LSM. The computational demand of this coupled model system allows long-term simulations. The first application of the fully-coupled modeling system is for the Poyang Lake basin (160,000 km²) in South China for the years 1979-1986. The performance of fully-coupled simulations requires first rational setups of WRF and HMS. For WRF, a double-nesting approach is applied covering East Asia at 30 km resolution and the Poyang Lake basin at 10 km using ERA Interim data as global forcing. HMS simulations are performed on the 10 km grid. Simulation results are validated against CRU, GPCC, APHRODITE, CPC, GLEAM and streamflow observations. The performance of stand-alone WRF, HMS and the fully coupled simulations are shown. Furthermore, the impact of groundwater coupling on soil moisture, evapotranspiration, temperature and precipitation is investigated. The potential of

  6. Hydrological model calibration for enhancing global flood forecast skill

    NASA Astrophysics Data System (ADS)

    Hirpa, Feyera A.; Beck, Hylke E.; Salamon, Peter; Thielen-del Pozo, Jutta

    2016-04-01

    Early warning systems play a key role in flood risk reduction, and their effectiveness is directly linked to streamflow forecast skill. The skill of a streamflow forecast is affected by several factors; among them are (i) model errors due to incomplete representation of physical processes and inaccurate parameterization, (ii) uncertainty in the model initial conditions, and (iii) errors in the meteorological forcing. In macro scale (continental or global) modeling, it is a common practice to use a priori parameter estimates over large river basins or wider regions, resulting in suboptimal streamflow estimations. The aim of this work is to improve flood forecast skill of the Global Flood Awareness System (GloFAS; www.globalfloods.eu), a grid-based forecasting system that produces flood forecast unto 30 days lead, through calibration of the distributed hydrological model parameters. We use a combination of in-situ and satellite-based streamflow data for automatic calibration using a multi-objective genetic algorithm. We will present the calibrated global parameter maps and report the forecast skill improvements achieved. Furthermore, we discuss current challenges and future opportunities with regard to global-scale early flood warning systems.

  7. Apply a hydrological model to estimate local temperature trends

    NASA Astrophysics Data System (ADS)

    Igarashi, Masao; Shinozawa, Tatsuya

    2014-03-01

    Continuous times series {f(x)} such as a depth of water is written f(x) = T(x)+P(x)+S(x)+C(x) in hydrological science where T(x),P(x),S(x) and C(x) are called the trend, periodic, stochastic and catastrophic components respectively. We simplify this model and apply it to the local temperature data such as given E. Halley (1693), the UK (1853-2010), Germany (1880-2010), Japan (1876-2010). We also apply the model to CO2 data. The model coefficients are evaluated by a symbolic computation by using a standard personal computer. The accuracy of obtained nonlinear curve is evaluated by the arithmetic mean of relative errors between the data and estimations. E. Halley estimated the temperature of Gresham College from 11/1692 to 11/1693. The simplified model shows that the temperature at the time rather cold compared with the recent of London. The UK and Germany data sets show that the maximum and minimum temperatures increased slowly from the 1890s to 1940s, increased rapidly from the 1940s to 1980s and have been decreasing since the 1980s with the exception of a few local stations. The trend of Japan is similar to these results.

  8. Stability and damping in a dynamical model of hillslope hydrology

    NASA Astrophysics Data System (ADS)

    Brandes, David; Duffy, Christopher J.; Cusumano, Joseph P.

    1998-12-01

    A stability analysis is performed on the two-state variable, integral-balance model of hillslope hydrology developed by Duffy [1996]. The motivation for the research is to develop a physically based, low-dimensional representation of inflow/outflow behavior within a hillslope-stream setting. Stability criteria are developed for the model equilibria and are evaluated using the results of numerical solutions of Richards' equation for a convex-concave hillslope geometry. We show that for homogeneous hillslopes of three widely varying soil types the single moisture equilibrium is classified as a stable node for low precipitation rates and a stable spiral for wet conditions. The spiral equilibrium indicates that the hillslope system is lightly damped, and transient oscillations of the state variables are expected for high precipitation rates. The timescale of these oscillations is of the order of several days to weeks for the model hillslopes examined. Furthermore, we demonstrate that the model contains a Hopf bifurcation from a stable static equilibrium to a stable limit cycle. The amplitude, phase, and frequency of the limit cycle are determined analytically using second-order averaging. However, this behavior is shown to be nonphysical for the particular homogeneous soils and hillslope geometry investigated. Implications of lightly damped behavior in the hillslope system include moisture oscillations in the field under wet conditions and difficulty in numerical solution of Richards' equation.

  9. 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.

  10. The TopoFlow Hydrologic Model: A New Community Project

    NASA Astrophysics Data System (ADS)

    Peckham, S. D.

    2004-05-01

    TopoFlow is a powerful, spatially-distributed hydrologic model with a user-friendly, wizard-style point-and-click interface. It is an open-source model that was designed to be easily modified and extended by a user community of hydrologists. Its main purpose is to model many different physical processes in a watershed with the goal of accurately predicting how various hydrologic variables will evolve in time in response to climatic forcings. The streamlined graphical interface makes it easy to perform multiple runs with different settings and different methods for parameterizing various physical processes; this makes it an excellent tool for research and teaching. Time evolutions for single pixels (such as hydrographs), collections of pixels, or entire grids (as animations) are all supported as output options. The currently supported physical processes are: Snowmelt (degree-day or energy balance method), Precipitation (uniform or varying in space/time), Evapotranspiration (Priestley-Taylor or energy balance), Infiltration (Green-Ampt coming soon), Channel/overland flow (Manning or law of wall) and Darcian, multi-layer subsurface flow. For each physical process, the user selects a "method" to be used to model that process from a droplist of options, and then specifies the input data that is required for that method and the output variables that are of interest. The ability to handle springs, sinks and canals was recently added. TopoFlow is designed so that users can use existing methods, share methods with others, or add their own methods and incorporate them into the graphical user interface. A method called "None" is always available to turn off any given physical process, and cleanly-written templates are provided to simplify the task of adding new methods. Input variables may be specified as a scalar (to be distributed uniformly), a time series, a spatial grid, or a grid seqence indexed by time. Many of the physical process methods used in TopoFlow are based on

  11. Stable Isotope Tracers in Large Scale Hydrological Models

    NASA Astrophysics Data System (ADS)

    Fekete, B. M.; Aggarwal, P.

    2004-05-01

    Stable isotopes of oxygen and hydrogen (deuterium and oxygen-18) have been shown to be effective tracers for characterizing hydrological processes in small river basins. Their application in large river basins has lagged behind due to the lack of sufficient isotope data. Recent availability of isotope data from most US rivers and subsequent efforts by the International Atomic Energy Agency (IAEA) to collect comprehensive global information on isotope compositions of river runoff is changing this situation. These data sets offer new opportunities to utilize stable isotopes in studies of large river basins. Recent work carried out jointly by the Water Systems Analysis Group of the University of New Hampshire and the Isotope Hydrology Section of the IAEA applied isotope-enabled global water balance and transport models to assess the feasibility of using isotope data for improving water balance estimations at large scales. The model implemented simple mixing in the various storage pools (e.g. snow pack, soil moisture, groundwater, and river channel) and fractionation during evapotranspiration. Sensitivity tests show that spatial and temporal distributions of isotopes in precipitation and their mixing in the various storage pools are the most important factors affecting the isotopic composition of river discharge. The groundwater storage pool plays a key role in the seasonal dynamics of stable isotope composition of river discharge. Fractionation during phase changes appears to have a less pronounced impact. These findings are consistent with those in small scale catchments where ``old water'' and ``new water'' (i.e. pre-event water and storm runoff) can be easily separated by using isotopes. Model validation using available data from the US rivers showed remarkable performance considering the inconsistencies in the temporal sampling of precipitation and runoff isotope composition records. The good model performance suggests that seasonal variations of the isotopic

  12. HYDROLOGY AND SEDIMENT MODELING USING THE BASINS NON-POINT SOURCE MODEL

    EPA Science Inventory

    The Non-Point Source Model (Hydrologic Simulation Program-Fortran, or HSPF) within the EPA Office of Water's BASINS watershed modeling system was used to simulate streamflow and total suspended solids within Contentnea Creek, North Carolina, which is a tributary of the Neuse Rive...

  13. Upscaling from research watersheds: an essential stage of trustworthy general-purpose hydrologic model building

    NASA Astrophysics Data System (ADS)

    McNamara, J. P.; Semenova, O.; Restrepo, P. J.

    2011-12-01

    Highly instrumented research watersheds provide excellent opportunities for investigating hydrologic processes. A danger, however, is that the processes observed at a particular research watershed are too specific to the watershed and not representative even of the larger scale watershed that contains that particular research watershed. Thus, models developed based on those partial observations may not be suitable for general hydrologic use. Therefore demonstrating the upscaling of hydrologic process from research watersheds to larger watersheds is essential to validate concepts and test model structure. The Hydrograph model has been developed as a general-purpose process-based hydrologic distributed system. In its applications and further development we evaluate the scaling of model concepts and parameters in a wide range of hydrologic landscapes. All models, either lumped or distributed, are based on a discretization concept. It is common practice that watersheds are discretized into so called hydrologic units or hydrologic landscapes possessing assumed homogeneous hydrologic functioning. If a model structure is fixed, the difference in hydrologic functioning (difference in hydrologic landscapes) should be reflected by a specific set of model parameters. Research watersheds provide the possibility for reasonable detailed combining of processes into some typical hydrologic concept such as hydrologic units, hydrologic forms, and runoff formation complexes in the Hydrograph model. And here by upscaling we imply not the upscaling of a single process but upscaling of such unified hydrologic functioning. The simulation of runoff processes for the Dry Creek research watershed, Idaho, USA (27 km2) was undertaken using the Hydrograph model. The information on the watershed was provided by Boise State University and included a GIS database of watershed characteristics and a detailed hydrometeorological observational dataset. The model provided good simulation results in

  14. Effects of soil parameterization on distributed hydrologic response: Testing a distributed hydrologic model using a hypothetical reality dataset

    NASA Astrophysics Data System (ADS)

    Cristea, N. C.; Kampf, S. K.; Mirus, B. B.; Loague, K.; Burges, S. J.

    2010-12-01

    Hydrologic data scarcity and discrepancies between model scale and point measurements are often identified as the most important limitations in evaluating distributed hydrologic models. To overcome data limitation issues, we present a framework for testing and evaluating distributed hydrologic models at the catchment scale using a hypothetical reality (HR) dataset. The HR is a synthetically generated dataset using the finite element 3D fully coupled surface-subsurface Integrated Hydrology Model (VanderKwaak, 1999) that emulates the hydrologic behavior of the real Tarrawarra catchment located in southeastern Australia. The long term HR dataset is composed of continuous outflow hydrograph and internal states at 55 observation nodes for an 11-year period as well as daily snapshots of the internal states at all nodes during the six months wet period of each year. A test model, MODHMS (HydroGeoLogic, Inc, 2000, Panday and Huyakorn, 2004), is used against the HR to illustrate the framework flexibility and functionality. We use examples from the long-term simulations to show the effects of the shape of the soil moisture retention curve and saturated hydraulic conductivity Ksat on both the integrated and distributed MODHMS hydrologic responses. We consider three base cases where we use class average van Genuchten parameters from the ROSETTA database (Schaap et al., 2001) for three soil types: clay loam, loamy sand and silty clay and one common Ksat value that is within one standard deviation interval of all three classes. For each of the three base cases we then vary Ksat sequentially to the one standard deviation interval limits for each class, according to ROSETTA, to illustrate the effects of Ksat variability for the same soil water retention curve. We examine a wet period and a dry period and discuss the range of simulated hydrographs and soil moisture states that result from different MODHMS soil parameterizations, as compared with the HR. We show soil moisture

  15. 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

  16. Using the DEM-based Xin'anjiang hydrologic model to simulate hydrologic characteristics in SiheRiver Basin

    NASA Astrophysics Data System (ADS)

    Qi, C. S.; Liu, D. D.; Tan, L. Y.; Zhu, L.

    2016-08-01

    In order to consider the spatial distribution of precipitation, the basin is generally divided by the Thiessen polygon method with the same concentration parameters in all divided units in Xin'anjiang hydrologic model, without considering the impact of terrain. The runoff concentration characteristics depend on the terrain condition to a great extent.Therefore, it is necessary to consider the impact of terrain condition in the model. The purpose of this article is to consider the impact of terrain condition to improve the Xin'anjiang hydrologic model. The basin is divided, and then the slopes of the divided sub-basins and the distances to the basin outlet are extracted based on the DEM. Twofunction relations between the terrain slope and the runoff concentration are established, and the application results of Sihe river basin show that the Xin'anjiang hydrologic model simulation precision is improved greatly based on the DEM,and it is more reasonable that the recession coefficient and the average gradient of the basin is an exponential relationship.

  17. visCOS: An R-package to evaluate model performance of hydrological models

    NASA Astrophysics Data System (ADS)

    Klotz, Daniel; Herrnegger, Mathew; Wesemann, Johannes; Schulz, Karsten

    2016-04-01

    The evaluation of model performance is a central part of (hydrological) modelling. Much attention has been given to the development of evaluation criteria and diagnostic frameworks. (Klemeš, 1986; Gupta et al., 2008; among many others). Nevertheless, many applications exist for which objective functions do not yet provide satisfying summaries. Thus, the necessity to visualize results arises in order to explore a wider range of model capacities, be it strengths or deficiencies. Visualizations are usually devised for specific projects and these efforts are often not distributed to a broader community (e.g. via open source software packages). Hence, the opportunity to explicitly discuss a state-of-the-art presentation technique is often missed. We therefore present a comprehensive R-package for evaluating model performance by visualizing and exploring different aspects of hydrological time-series. The presented package comprises a set of useful plots and visualization methods, which complement existing packages, such as hydroGOF (Zambrano-Bigiarini et al., 2012). It is derived from practical applications of the hydrological models COSERO and COSEROreg (Kling et al., 2014). visCOS, providing an interface in R, represents an easy-to-use software package for visualizing and assessing model performance and can be implemented in the process of model calibration or model development. The package provides functions to load hydrological data into R, clean the data, process, visualize, explore and finally save the results in a consistent way. Together with an interactive zoom function of the time series, an online calculation of the objective functions for variable time-windows is included. Common hydrological objective functions, such as the Nash-Sutcliffe Efficiency and the Kling-Gupta Efficiency, can also be evaluated and visualized in different ways for defined sub-periods like hydrological years or seasonal sections. Many hydrologists use long-term water-balances as a

  18. Modeling low impact development potential with hydrological response units.

    PubMed

    Eric, Marija; Fan, Celia; Joksimovic, Darko; Li, James Y

    2013-01-01

    Evaluations of benefits of implementing low impact development (LID) stormwater management techniques can extend up to a watershed scale. This presents a challenge for representing them in watershed models, since they are typically orders of magnitude smaller in size. This paper presents an approach that is focused on trying to evaluate the benefits of implementing LIDs on a lot level. The methodology uses the concept of urban hydrological response Unit and results in developing and applying performance curves that are a function of lot properties to estimate the potential benefit of large-scale LID implementation. Lot properties are determined using a municipal geographic information system database and processed to determine groups of lots with similar properties. A representative lot from each group is modeled over a typical rainfall year using USEPA Stormwater Management Model to develop performance functions that relate the lot properties and the change in annual runoff volume and corresponding phosphorus loading with different LIDs implemented. The results of applying performance functions on all urban areas provide the potential locations, benefit and cost of implementation of all LID techniques, guiding future decisions for LID implementation by watershed area municipalities.

  19. Regional scale hydrology with a new land surface processes model

    NASA Technical Reports Server (NTRS)

    Laymon, Charles; Crosson, William

    1995-01-01

    Through the CaPE Hydrometeorology Project, we have developed an understanding of some of the unique data quality issues involved in assimilating data of disparate types for regional-scale hydrologic modeling within a GIS framework. Among others, the issues addressed here include the development of adequate validation of the surface water budget, implementation of the STATSGO soil data set, and implementation of a remote sensing-derived landcover data set to account for surface heterogeneity. A model of land surface processes has been developed and used in studies of the sensitivity of surface fluxes and runoff to soil and landcover characterization. Results of these experiments have raised many questions about how to treat the scale-dependence of land surface-atmosphere interactions on spatial and temporal variability. In light of these questions, additional modifications are being considered for the Marshall Land Surface Processes Model. It is anticipated that these techniques can be tested and applied in conjunction with GCIP activities over regional scales.

  20. Using GPS loading deformation to distinguish different hydrological measurements and models

    NASA Astrophysics Data System (ADS)

    Fu, Y.; van Dam, T. M.

    2015-12-01

    The earth's lithosphere is deformed elastically by seasonal and inter-annual surface mass variations. The Global Positioning System (GPS) accurately measures 3D crustal deformation caused by surface hydrological mass movements. In this study, we calculate the loading deformation using different hydrological models and in-situ hydrological measurements, and compare those modeled results with actual deformation measurements of the dense GPS network in United States and Europe. Therefore, GPS can be used as an independent tool to evaluate the differences between hydrological measurements and models. We are particularly interested in comparing the snow volume differences between in-situ snow measurement (such as SNOTEL) and the snow components of simulated models (such as GLDAS or NLDAS). We, therefore, demonstrate that GPS as a geodetic observation can provide valuable information for hydrological studies.

  1. Impact of modellers' decisions on hydrological a priori predictions

    NASA Astrophysics Data System (ADS)

    Holländer, H. M.; Bormann, H.; Blume, T.; Buytaert, W.; Chirico, G. B.; Exbrayat, J.-F.; Gustafsson, D.; Hölzel, H.; Krauße, T.; Kraft, P.; Stoll, S.; Blöschl, G.; Flühler, H.

    2014-06-01

    In practice, the catchment hydrologist is often confronted with the task of predicting discharge without having the needed records for calibration. Here, we report the discharge predictions of 10 modellers - using the model of their choice - for the man-made Chicken Creek catchment (6 ha, northeast Germany, Gerwin et al., 2009b) and we analyse how well they improved their prediction in three steps based on adding information prior to each following step. The modellers predicted the catchment's hydrological response in its initial phase without having access to the observed records. They used conceptually different physically based models and their modelling experience differed largely. Hence, they encountered two problems: (i) to simulate discharge for an ungauged catchment and (ii) using models that were developed for catchments, which are not in a state of landscape transformation. The prediction exercise was organized in three steps: (1) for the first prediction the modellers received a basic data set describing the catchment to a degree somewhat more complete than usually available for a priori predictions of ungauged catchments; they did not obtain information on stream flow, soil moisture, nor groundwater response and had therefore to guess the initial conditions; (2) before the second prediction they inspected the catchment on-site and discussed their first prediction attempt; (3) for their third prediction they were offered additional data by charging them pro forma with the costs for obtaining this additional information. Holländer et al. (2009) discussed the range of predictions obtained in step (1). Here, we detail the modeller's assumptions and decisions in accounting for the various processes. We document the prediction progress as well as the learning process resulting from the availability of added information. For the second and third steps, the progress in prediction quality is evaluated in relation to individual modelling experience and costs of

  2. Calibration of a Hydrologic Model Considering Input Uncertainty in Assessing Climate Change Impact on Streamflow

    NASA Astrophysics Data System (ADS)

    Bolisetti, T.; Datta, A. R.; Balachandar, R.

    2009-05-01

    Studies on impact assessment and the corresponding uncertainties in hydrologic regime predictions is of paramount in developing water resources management plans under climate change scenarios,. The variability in hydrologic model parameters is one of the major sources of uncertainties associated with climate change impact on streamflow. Uncertainty in hydrologic model parameters may arise from the choice of model calibration technique, model calibration period, model structure and response variables. The recent studies show that consideration of uncertainties in input variables (precipitation, evapotranspiration etc.) during calibration of a hydrologic model has resulted in decrease in prediction uncertainty. The present study has examined the significance of input uncertainty in hydrologic model calibration for climate change impact studies. A physically distributed hydrologic model, Soil and Water Assessment Tool (SWAT), is calibrated considering uncertainties in (i) model parameters only, and (ii) both model parameters and precipitation input. The Markov chain Monte Carlo algorithm is used to estimate the posterior probability density function of hydrologic model parameters. The observed daily precipitation and streamflow data of the Canard River watershed of Essex region, Ontario, Canada are used as input and output variables, respectively, during calibration. The parameter sets of the 100 most skillful hydrologic model simulations obtained from each calibration technique are used for predicting streamflow by 2070s under climate change conditions. In each run, the climate predictions of the Canadian Regional Climate Model (CRCM) for SRES scenario A2 are used as input to the hydrologic model for streamflow prediction. The paper presents the results of uncertainty in seasonal and annual streamflow prediction. The outcome of the study is expected to contribute to the assessment of uncertainty in climate change impact studies and better management of available

  3. Integrating fire with hydrological projections: model evaluation to identify uncertainties and tradeoffs in model complexity

    NASA Astrophysics Data System (ADS)

    Kennedy, M.; McKenzie, D.

    2013-12-01

    It is imperative for resource managers to understand how a changing climate might modify future watershed and hydrological processes, and such an understanding is incomplete if disturbances such as fire are not integrated with hydrological projections. Can a robust fire spread model be developed that approximates patterns of fire spread in response to varying topography wind patterns, and fuel loads and moistures, without requiring intensive calibration to each new study area or time frame? We assessed the performance of a stochastic model of fire spread (WMFire), integrated with the Regional Hydro-Ecological Simulation System (RHESSys), for projecting the effects of climatic change on mountain watersheds. We first use Monte Carlo inference to determine that the fire spread model is able to replicate the spatial pattern of fire spread for a contemporary wildfire in Washington State (the Tripod fire), measured by the lacunarity and fractal dimension of the fire. We then integrate a version of WMFire able to replicate the contemporary wildfire with RHESSys and simulate a New Mexico watershed over the calibration period of RHESSys (1941-1997). In comparing the fire spread model to a single contemporary wildfire we found issues in parameter identifiability for several of the nine parameters, due to model input uncertainty and insensitivity of the mathematical function to certain ranges of the parameter values. Model input uncertainty is caused by the inherent difficulty in reconstructing fuel loads and fuel moistures for a fire event after the fire has occurred, as well as by issues in translating variables relevant to hydrological processes produced by the hydrological model to those known to affect fire spread and fire severity. The first stage in the model evaluation aided the improvement of the model in both of these regards. In transporting the model to a new landscape in order to evaluate fire regimes in addition to patterns of fire spread, we find reasonable

  4. Modular modeling system for building distributed hydrologic models with a user-friendly software package

    NASA Astrophysics Data System (ADS)

    Wi, S.; Ray, P. A.; Brown, C.

    2015-12-01

    A software package developed to facilitate building distributed hydrologic models in a modular modeling system is presented. The software package provides a user-friendly graphical user interface that eases its practical use in water resources-related research and practice. The modular modeling system organizes the options available to users when assembling models according to the stages of hydrological cycle, such as potential evapotranspiration, soil moisture accounting, and snow/glacier melting processes. The software is intended to be a comprehensive tool that simplifies the task of developing, calibrating, validating, and using hydrologic models through the inclusion of intelligent automation to minimize user effort, and reduce opportunities for error. Processes so far automated include the definition of system boundaries (i.e., watershed delineation), climate and geographical input generation, and parameter calibration. Built-in post-processing toolkits greatly improve the functionality of the software as a decision support tool for water resources system management and planning. Example post-processing toolkits enable streamflow simulation at ungauged sites with predefined model parameters, and perform climate change risk assessment by means of the decision scaling approach. The software is validated through application to watersheds representing a variety of hydrologic regimes.

  5. A seawater desalination scheme for global hydrological models

    NASA Astrophysics Data System (ADS)

    Hanasaki, Naota; Yoshikawa, Sayaka; Kakinuma, Kaoru; Kanae, Shinjiro

    2016-10-01

    Seawater desalination is a practical technology for providing fresh water to coastal arid regions. Indeed, the use of desalination is rapidly increasing due to growing water demand in these areas and decreases in production costs due to technological advances. In this study, we developed a model to estimate the areas where seawater desalination is likely to be used as a major water source and the likely volume of production. The model was designed to be incorporated into global hydrological models (GHMs) that explicitly include human water usage. The model requires spatially detailed information on climate, income levels, and industrial and municipal water use, which represent standard input/output data in GHMs. The model was applied to a specific historical year (2005) and showed fairly good reproduction of the present geographical distribution and national production of desalinated water in the world. The model was applied globally to two periods in the future (2011-2040 and 2041-2070) under three distinct socioeconomic conditions, i.e., SSP (shared socioeconomic pathway) 1, SSP2, and SSP3. The results indicate that the usage of seawater desalination will have expanded considerably in geographical extent, and that production will have increased by 1.4-2.1-fold in 2011-2040 compared to the present (from 2.8 × 109 m3 yr-1 in 2005 to 4.0-6.0 × 109 m3 yr-1), and 6.7-17.3-fold in 2041-2070 (from 18.7 to 48.6 × 109 m3 yr-1). The estimated global costs for production for each period are USD 1.1-10.6 × 109 (0.002-0.019 % of the total global GDP), USD 1.6-22.8 × 109 (0.001-0.020 %), and USD 7.5-183.9 × 109 (0.002-0.100 %), respectively. The large spreads in these projections are primarily attributable to variations within the socioeconomic scenarios.

  6. 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.

  7. 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

  8. Impact of modellers' decisions on hydrological a priori predictions

    NASA Astrophysics Data System (ADS)

    Holländer, H. M.; Bormann, H.; Blume, T.; Buytaert, W.; Chirico, G. B.; Exbrayat, J.-F.; Gustafsson, D.; Hölzel, H.; Krauße, T.; Kraft, P.; Stoll, S.; Blöschl, G.; Flühler, H.

    2013-07-01

    The purpose of this paper is to stimulate a re-thinking of how we, the catchment hydrologists, could become reliable forecasters. A group of catchment modellers predicted the hydrological response of a man-made 6 ha catchment in its initial phase (Chicken Creek) without having access to the observed records. They used conceptually different model families. Their modelling experience differed largely. The prediction exercise was organized in three steps: (1) for the 1st prediction modellers received a basic data set describing the internal structure of the catchment (somewhat more complete than usually available to a priori predictions in ungauged catchments). They did not obtain time series of stream flow, soil moisture or groundwater response. (2) Before the 2nd improved prediction they inspected the catchment on-site and attended a workshop where the modellers presented and discussed their first attempts. (3) For their improved 3rd prediction they were offered additional data by charging them pro forma with the costs for obtaining this additional information. Holländer et al. (2009) discussed the range of predictions obtained in step 1. Here, we detail the modeller's decisions in accounting for the various processes based on what they learned during the field visit (step 2) and add the final outcome of step 3 when the modellers made use of additional data. We document the prediction progress as well as the learning process resulting from the availability of added information. For the 2nd and 3rd step, the progress in prediction quality could be evaluated in relation to individual modelling experience and costs of added information. We learned (i) that soft information such as the modeller's system understanding is as important as the model itself (hard information), (ii) that the sequence of modelling steps matters (field visit, interactions between differently experienced experts, choice of model, selection of available data, and methods for parameter guessing

  9. Hydrologic Implications of Dynamical and Statistical Approaches to Downscaling Climate Model Outputs

    SciTech Connect

    Wood, Andrew W; Leung, Lai R; Sridhar, V; Lettenmaier, D P

    2004-01-01

    Six approaches for downscaling climate model outputs for use in hydrologic simulation were evaluated, with particular emphasis on each method's ability to produce precipitation and other variables used to drive a macroscale hydrology model applied at much higher spatial resolution than the climate model. Comparisons were made on the basis of a twenty-year retrospective (1975–1995) climate simulation produced by the NCAR-DOE Parallel Climate Model (PCM), and the implications of the comparison for a future (2040–2060) PCM climate scenario were also explored. The six approaches were made up of three relatively simple statistical downscaling methods – linear interpolation (LI), spatial disaggregation (SD), and bias-correction and spatial disaggregation (BCSD) – each applied to both PCM output directly (at T42 spatial resolution), and after dynamical downscaling via a Regional Climate Model (RCM – at ½-degree spatial resolution), for downscaling the climate model outputs to the 1/8-degree spatial resolution of the hydrological model. For the retrospective climate simulation, results were compared to an observed gridded climatology of temperature and precipitation, and gridded hydrologic variables resulting from forcing the hydrologic model with observations. The most significant findings are that the BCSD method was successful in reproducing the main features of the observed hydrometeorology from the retrospective climate simulation, when applied to both PCM and RCM outputs. Linear interpolation produced better results using RCM output than PCM output, but both methods (PCM-LI and RCM-LI) lead to unacceptably biased hydrologic simulations. Spatial disaggregation of the PCM output produced results similar to those achieved with the RCM interpolated output; nonetheless, neither PCM nor RCM output was useful for hydrologic simulation purposes without a bias-correction step. For the future climate scenario, only the BCSD-method (using PCM or RCM) was able to

  10. Concepts of Information Content and Likelihood in Parameter Calibration for Hydrological Simulation Models

    NASA Astrophysics Data System (ADS)

    Beven, Keith; Smith, Paul

    2013-04-01

    There remains a great deal of uncertainty about uncertainty estimation in hydrological modelling. Given that hydrology is still a subject limited by the available measurement techniques, it does not appear that the issue of epistemic error in hydrological data will go away for the foreseeable future and it may be necessary to find a way of allowing for robust model conditioning and more subjective treatments of potential epistemic errors in prediction. This paper attempts to analyse how the results of the epistemic uncertainties inherent in the hydrological modelling process impact on model conditioning, hypothesis testing and forecasting. We propose an assessment of the information in hydrological data used for calibration based upon hydrological reasoning. This is performed prior to the assessment of any of the proposed hydrological models. It can then inform the evaluation of competing models and resulting prediction uncertainties. An illustration of how this information assessment might influence model conditioning is provided by an application; the rainfall-runoff modelling of a catchment in Northern England where inconsistent data for some events can introduce disinformation into the model conditioning process. The construction of the resulting prediction uncertainties is also considered.

  11. On the Concepts of Information Content and Likelihood in Parameter Calibration for Hydrological Simulation Models (Invited)

    NASA Astrophysics Data System (ADS)

    Smith, P. J.; Beven, K.

    2013-12-01

    There remains a great deal of uncertainty about appropriate uncertainty estimation in hydrological modelling. Given that hydrology is still a subject limited by the available measurement techniques; and we cannot go back in time to take better observations of the past; the issue of epistemic error in hydrological data will not go away for the foreseeable future. It is therefore necessary to find a way of allowing for robust model conditioning and more subjective treatments of potential epistemic errors in prediction. This paper offers an analysis of how the epistemic uncertainties inherent in the hydrological modelling process impact on model conditioning, hypothesis testing and forecasting. We propose an assessment of the information in hydrological data used for calibration based upon hydrological reasoning and prior to the assessment of any of the proposed hydrological models. This can then inform the evaluation of competing models and resulting prediction uncertainties. An illustration of how this information assessment might influence model conditioning is provided by an application; the rainfall-runoff modelling of a catchment in Northern England where inconsistent data for some events can introduce disinformation into the model conditioning process. The construction of the resulting prediction uncertainties is also considered.

  12. 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

  13. New hydrologic model of fluid migration in deep porous media

    NASA Astrophysics Data System (ADS)

    Dmitrievsky, A.; Balanyuk, I.

    2009-04-01

    The authors present a new hydrological model of mantle processes that effect on formation of oil-and-gas bearing basins, fault tectonics and thermal convection. Any fluid migration is initially induced by lateral stresses in the crust and lithosphere which result from global geodynamic processes related to the mantle convection. The global processes are further transformed into regional movements in weakness zones. Model of porous media in deep fractured zones and idea of self-oscillation processes in mantle layers and fractured zones of the crust at different depths was used as the basis for developed concept. The content of these notions resides in the fact that there are conditions of dynamic balance in mantle layers originating as a result of combination and alternate actions of compaction and dilatance mechanisms. These mechanisms can be manifested in different combinations and under different conditions as well as can be complemented by other processes influencing on regime of fluid migration. They can act under condition of passive margin, ocean rift and ocean subduction zones as well as in consolidated platform and sheet. Self-oscillation regime, sub vertical direction of fluid flows, anomalously high layer pressure, and high level of anomalies of various geophysical fields are common for them. A certain class of fluid dynamic models describing consolidation of sedimentary basins, free oscillation processes slow and quick (at the final stage) fluid dynamic processes of the evolution of a sedimentary basin in subduction zones is considered for the first time. The last model of quick fluid dynamic processes reflects the process of formation of hydrocarbon deposits in the zones of collision of lithosphere plates. The results of numerical simulation and diagrams reflecting consecutive stages of the gas-fluid dynamic front propagation are assessed of the Pri-Caspian depression as the example. Calculations with this model will simultaneously be carried out for

  14. Modelling of green roofs' hydrologic performance using EPA's SWMM.

    PubMed

    Burszta-Adamiak, E; Mrowiec, M

    2013-01-01

    Green roofs significantly affect the increase in water retention and thus the management of rain water in urban areas. In Poland, as in many other European countries, excess rainwater resulting from snowmelt and heavy rainfall contributes to the development of local flooding in urban areas. Opportunities to reduce surface runoff and reduce flood risks are among the reasons why green roofs are more likely to be used also in this country. However, there are relatively few data on their in situ performance. In this study the storm water performance was simulated for the green roofs experimental plots using the Storm Water Management Model (SWMM) with Low Impact Development (LID) Controls module (version 5.0.022). The model consists of many parameters for a particular layer of green roofs but simulation results were unsatisfactory considering the hydrologic response of the green roofs. For the majority of the tested rain events, the Nash coefficient had negative values. It indicates a weak fit between observed and measured flow-rates. Therefore complexity of the LID module does not affect the increase of its accuracy. Further research at a technical scale is needed to determine the role of the green roof slope, vegetation cover and drying process during the inter-event periods.

  15. 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

  16. Coupling of the simultaneous heat and water model with a distributed hydrological model and evaluation of the combined model in a cold region watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To represent the effects of frozen soil on hydrology in cold regions, a new physically based distributed hydrological model has been developed by coupling the simultaneous heat and water model (SHAW) with the geomorphology based distributed hydrological model (GBHM), under the framework of the water...

  17. Impact of model development, calibration and validation decisions on hydrological simulations in West Lake Erie Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watershed simulation models are used extensively to investigate hydrologic processes, landuse and climate change impacts, pollutant load assessments and best management practices (BMPs). Developing, calibrating and validating these models require a number of critical decisions that will influence t...

  18. 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...

  19. Evapotranspiration and irrigation algorithms in hydrologic modeling:Present Status and Opportunities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrologic models are used extensively for predicting water availability and water quality responses to alternative irrigation, tillage, crop, and fertilizer management practices and global climate change. Modeling results have been frequently used by regulatory agencies for developing remedial meas...

  20. 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…

  1. 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.

  2. Flexibility on storage-release based distributed hydrologic modeling with object-oriented approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the availability of advanced hydrologic data in the public domain such as remotely sensed and climate change scenario data, there is a need for a modeling framework that is capable of using these data to simulate and extend hydrologic processes with multidisciplinary approaches for sustainable ...

  3. Improvement and Comparative Assessment of a New Hydrological Modelling Approach for the Ouémé River Basin (Bénin), West Africa

    NASA Astrophysics Data System (ADS)

    GABA, C. O. U.

    2015-12-01

    Assessing water resources is still an important issue especially in the context of climatic changes. Although numerous hydrological models exist, new approaches are still under investigation. In this context, we propose a new modelling approach based on the Physics Principle of Least Action. A first version of a Least Action based model, in its deterministic version has already given very good results on simulating the Bétérou catchment in the Ouémé basin, Benin. The paper presents new hypotheses to go further in the model development with a view of widening its application. The improved version of the model MODYPMA was applied on 22 subcatchments in Africa, in Bénin, Côte d'Ivoire, Ethiopia; in Europe, and in the USA. Its performance was compared to two well known lumped conceptual models, the GR4J and HBV models. The model could be successfully calibrated and validated; it shows a good performance for a range of scales but a limited applicability to catchments smaller than 500 km2 . The analysis revealed that the three models have similar performance and timing errors. The parameter uncertainty was analysed using the GLUE methodology. It is concluded that model uncertainty is higher during high flows and that uncertainty analysis should include the uncertainty of the discharge data. Finally, some aspects that further research must address are brought out.

  4. A model-model and data-model comparison for the early Eocene hydrological cycle

    NASA Astrophysics Data System (ADS)

    Carmichael, Matthew J.; Lunt, Daniel J.; Huber, Matthew; Heinemann, Malte; Kiehl, Jeffrey; LeGrande, Allegra; Loptson, Claire A.; Roberts, Chris D.; Sagoo, Navjit; Shields, Christine; Valdes, Paul J.; Winguth, Arne; Winguth, Cornelia; Pancost, Richard D.

    2016-02-01

    A range of proxy observations have recently provided constraints on how Earth's hydrological cycle responded to early Eocene climatic changes. However, comparisons of proxy data to general circulation model (GCM) simulated hydrology are limited and inter-model variability remains poorly characterised. In this work, we undertake an intercomparison of GCM-derived precipitation and P - E distributions within the extended EoMIP ensemble (Eocene Modelling Intercomparison Project; Lunt et al., 2012), which includes previously published early Eocene simulations performed using five GCMs differing in boundary conditions, model structure, and precipitation-relevant parameterisation schemes. We show that an intensified hydrological cycle, manifested in enhanced global precipitation and evaporation rates, is simulated for all Eocene simulations relative to the preindustrial conditions. This is primarily due to elevated atmospheric paleo-CO2, resulting in elevated temperatures, although the effects of differences in paleogeography and ice sheets are also important in some models. For a given CO2 level, globally averaged precipitation rates vary widely between models, largely arising from different simulated surface air temperatures. Models with a similar global sensitivity of precipitation rate to temperature (dP/dT) display different regional precipitation responses for a given temperature change. Regions that are particularly sensitive to model choice include the South Pacific, tropical Africa, and the Peri-Tethys, which may represent targets for future proxy acquisition. A comparison of early and middle Eocene leaf-fossil-derived precipitation estimates with the GCM output illustrates that GCMs generally underestimate precipitation rates at high latitudes, although a possible seasonal bias of the proxies cannot be excluded. Models which warm these regions, either via elevated CO2 or by varying poorly constrained model parameter values, are most successful in simulating a

  5. Hydrological Modeling Reproducibility Through Data Management and Adaptors for Model Interoperability

    NASA Astrophysics Data System (ADS)

    Turner, M. A.

    2015-12-01

    Because of a lack of centralized planning and no widely-adopted standards among hydrological modeling research groups, research communities, and the data management teams meant to support research, there is chaos when it comes to data formats, spatio-temporal resolutions, ontologies, and data availability. All this makes true scientific reproducibility and collaborative integrated modeling impossible without some glue to piece it all together. Our Virtual Watershed Integrated Modeling System provides the tools and modeling framework hydrologists need to accelerate and fortify new scientific investigations by tracking provenance and providing adaptors for integrated, collaborative hydrologic modeling and data management. Under global warming trends where water resources are under increasing stress, reproducible hydrological modeling will be increasingly important to improve transparency and understanding of the scientific facts revealed through modeling. The Virtual Watershed Data Engine is capable of ingesting a wide variety of heterogeneous model inputs, outputs, model configurations, and metadata. We will demonstrate one example, starting from real-time raw weather station data packaged with station metadata. Our integrated modeling system will then create gridded input data via geostatistical methods along with error and uncertainty estimates. These gridded data are then used as input to hydrological models, all of which are available as web services wherever feasible. Models may be integrated in a data-centric way where the outputs too are tracked and used as inputs to "downstream" models. This work is part of an ongoing collaborative Tri-state (New Mexico, Nevada, Idaho) NSF EPSCoR Project, WC-WAVE, comprised of researchers from multiple universities in each of the three states. The tools produced and presented here have been developed collaboratively alongside watershed scientists to address specific modeling problems with an eye on the bigger picture of

  6. 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

  7. 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

  8. Hydrological extremes in China during 1971-2000: from observations and models

    NASA Astrophysics Data System (ADS)

    Liu, Xingcai; He, Jun; Mu, Mengfei; Tang, Qiuhong

    2016-04-01

    Hydrological cycle in China has been greatly affected by both significant climate change and human disturbance since the 1970s. The ISI-MIP2 project provides such a framework by involving multiple hydrological models to reproduce the global hydrological cycle considering both climate change and human impacts. However, the multimodel simulations yet need validation at regional applications. In this study, we evaluate the multimodel simulations of river flow using monthly observations from about 300 hydrological stations in China during the 1970-2000 period. The Nash-Sutcliffe (NS) coefficient and mean relative errors (MRE) are computed for each station to measure the performance of multimodel simulations. Trends in river flow are also compared for observations and simulations. On the basis of overall comparison, we evaluate the hydrological extremes derived from observations and simulations. The hydrological extremes are identified using a standardized discharge index (SDI), which resembles the standardized precipitation index (SPI), based on monthly river flow. The performance of multimodel simulations in reproducing hydrological extremes shows regional difference, and which seems to be greatly associated with the intensity of human activities in the basins. The uncertainty in multimodel simulations may be from models and input data. The uncertainties from both the hydrological models and forcings are investigated, and uncertainty from human impact related input (irrigated area and reservoir storage) is discussed with respect to reported data in China.

  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

  10. 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

  11. Frozen soil parameterization in a distributed biosphere hydrological model

    NASA Astrophysics Data System (ADS)

    Wang, L.; Koike, T.; Yang, K.; Jin, R.; Li, H.

    2009-11-01

    In this study, a frozen soil parameterization has been modified and incorporated into a distributed biosphere hydrological model (WEB-DHM). The WEB-DHM with the frozen scheme was then rigorously evaluated in a small cold area, the Binngou watershed, against the in-situ observations from the WATER (Watershed Allied Telemetry Experimental Research). In the summer 2008, land surface parameters were optimized using the observed surface radiation fluxes and the soil temperature profile at the Dadongshu-Yakou (DY) station in July; and then soil hydraulic parameters were obtained by the calibration of the July soil moisture profile at the DY station and by the calibration of the discharges at the basin outlet in July and August that covers the annual largest flood peak of 2008. The calibrated WEB-DHM with the frozen scheme was then used for a yearlong simulation from 21 November 2007 to 20 November 2008, to check its performance in cold seasons. Results showed that the WEB-DHM with the frozen scheme has given much better performance than the WEB-DHM without the frozen scheme, in the simulations of soil moisture profile at the DY station and the discharges at the basin outlet in the yearlong simulation.

  12. Frozen soil parameterization in a distributed biosphere hydrological model

    NASA Astrophysics Data System (ADS)

    Wang, L.; Koike, T.; Yang, K.; Jin, R.; Li, H.

    2010-03-01

    In this study, a frozen soil parameterization has been modified and incorporated into a distributed biosphere hydrological model (WEB-DHM). The WEB-DHM with the frozen scheme was then rigorously evaluated in a small cold area, the Binngou watershed, against the in-situ observations from the WATER (Watershed Allied Telemetry Experimental Research). First, by using the original WEB-DHM without the frozen scheme, the land surface parameters and two van Genuchten parameters were optimized using the observed surface radiation fluxes and the soil moistures at upper layers (5, 10 and 20 cm depths) at the DY station in July. Second, by using the WEB-DHM with the frozen scheme, two frozen soil parameters were calibrated using the observed soil temperature at 5 cm depth at the DY station from 21 November 2007 to 20 April 2008; while the other soil hydraulic parameters were optimized by the calibration of the discharges at the basin outlet in July and August that covers the annual largest flood peak in 2008. With these calibrated parameters, the WEB-DHM with the frozen scheme was then used for a yearlong validation from 21 November 2007 to 20 November 2008. Results showed that the WEB-DHM with the frozen scheme has given much better performance than the WEB-DHM without the frozen scheme, in the simulations of soil moisture profile at the cold regions catchment and the discharges at the basin outlet in the yearlong simulation.

  13. Modelling hydrology and water quality in a Mediterranean catchment

    NASA Astrophysics Data System (ADS)

    Candela, Angela; Viviani, Gaspare

    2010-05-01

    In this study the SWAT model has been used in order to analyse and quantify pollution dynamics at basin scale depending on concentrated and diffuse sources. Nowadays, the receiving water bodies quality safeguarding is of growing importance due to the promulgation of recent laws as well as the growing sensitivity regarding the environment issues by the scientific and practitioner committee. Recently the EU 2000/60 (Water Framework Directive) makes the analysis of receiving water bodies even more complex by integrating the pollution in urban areas in a framework of the pollution sources at catchment scale. and making necessary further integration of environmental impacts associated with discharges concentrates civilian and productive with the widespread pollution linked mainly to agriculture and zoo-technical activities. The complexity of natural systems and the large number of polluting sources and variables to be monitored requires the adoption of models able to get a better view of the whole system in a simplified way without neglecting the most important physical phenomena. Particularly, in this study the SWAT model was considered since it is an integrated hydrological model that are, nowadays, needed to support the implementation of integrated water management plans and to comply with the current requirements of the WFD. In addition, the SWAT model is interfaced with the ARC-VIEW software which allows easy pre-and post processing of the spatially distributed input data, driving the rainfall-runoff process. The model has been applied to the experimental Nocella catchment located in Sicily (Italy), with an area of about 50 km2. The river receives wastewater and stormwater from two urban areas drained by combined sewers. The study demonstrates that the analysis of water quality in partially urbanised natural basins is complex depending on variable polluting contributions of the different parts of the system depending on specific polluting compounds. The model was

  14. Remote sensing and hydrological modeling of burn scars

    NASA Astrophysics Data System (ADS)

    Miller, Mary Ellen

    This study examined the potential usefulness of combining remote sensing data with hydrologic models and mapping tools available from Geographic Information Systems (GIS), to evaluate the effects of wildfire. Four subprojects addressed this issue: (1) validation of burn scar maps derived from the Advanced Very High Resolution Radiometer (AVHRR) with the National Fire Occurrence Database; (2) testing the potential of thermal MODIS (Moderate Resolution Imaging Spectroradiometer) data for near-real time burn scar and fire severity mapping; (3) evaluation of Landsat derived burn severity maps within WEPP through the Geo-spatial interface for the Water Erosion Prediction Project (GeoWEPP), and (4) predicting potential post-fire erosion for western U.S. forests utilizing existing datasets and models. Wildfire poses incredibly complex management problems in all of its stages. Today's land managers have the option of trying to mitigate the effects of a severe fire before it occurs by fuel management practices. This process is expensive especially considering the uncertainty of when and where the next fire in a given region will occur. When a wildfire does occur, deciding when to let it burn and when to suppress it may lead to controversial decisions. In addition to the threat to life and property from the fire itself, smoke emissions from large fires can cause air quality problems in distant airsheds. Even after the fire is extinguished, erosion and water quality problems may pose difficult management questions. Contributions stemming from these studies include improved burn scar maps for studying historical fire extent and demonstration of the feasibility of using thermal satellite data to predict burn scar extent when clouds and smoke obscure visible bands. The incorporation of Landsat derived burn severity maps was shown to improve post-fire erosion modeling results. Finally the potential post-fire burn severity and erosion risk maps generated for western US forests

  15. Improving process representation in conceptual hydrological model calibration using climate simulations

    NASA Astrophysics Data System (ADS)

    Minville, Marie; Cartier, Dominique; Guay, Catherine; Leclaire, Louis-Alexandre; Audet, Charles; Le Digabel, Sébastien; Merleau, James

    2014-06-01

    Different sets of calibrated model parameters can yield divergent hydrological simulations which in turn can lead to different operational decisions or scientific conclusions. In order to obtain reliable hydrological results, proper calibration is therefore fundamental. This article proposes a new calibration approach for conceptual hydrological models based on the paradigm that hydrological process representation, along with the reproduction of observed streamflows, need to be taken into account when assessing the performance of a hydrological model. Several studies have shown that complementary data can be used to improve hydrological process representation and make hydrological modeling more robust. In the current study, the process of interest is actual evapotranspiration (AET). In order to obtain a more realistic representation of AET, meteorological variables and the AET mean annual cycle simulated by a regional climate model (RCM) driven by reanalysis are used to impose constraints during the optimization procedure. This calibration strategy is compared to a second strategy which relies on AET derived from reference data and to the classical approach based solely on the reproduction of observed discharges. The different methodologies are applied to calibrate the lumped conceptual model HSAMI, used operationally at Hydro-Québec, for six Canadian snow-dominated basins with various hydrometeorological and physiographical characteristics.

  16. Enhancing Hydrologic Modelling in the Coupled Weather Research and Forecasting-Urban Modelling System

    NASA Astrophysics Data System (ADS)

    Yang, Jiachuan; Wang, Zhi-Hua; Chen, Fei; Miao, Shiguang; Tewari, Mukul; Voogt, James A.; Myint, Soe

    2015-04-01

    Urbanization modifies surface energy and water budgets, and has significant impacts on local and regional hydroclimate. In recent decades, a number of urban canopy models have been developed and implemented into the Weather Research and Forecasting (WRF) model to capture urban land-surface processes. Most of these models are inadequate due to the lack of realistic representation of urban hydrological processes. Here, we implement physically-based parametrizations of urban hydrological processes into the single layer urban canopy model in the WRF model. The new single-layer urban canopy model features the integration of, (1) anthropogenic latent heat, (2) urban irrigation, (3) evaporation from paved surfaces, and (4) the urban oasis effect. The new WRF-urban modelling system is evaluated against field measurements for four different cities; results show that the model performance is substantially improved as compared to the current schemes, especially for latent heat flux. In particular, to evaluate the performance of green roofs as an urban heat island mitigation strategy, we integrate in the urban canopy model a multilayer green roof system, enabled by the physical urban hydrological schemes. Simulations show that green roofs are capable of reducing surface temperature and sensible heat flux as well as enhancing building energy efficiency.

  17. Elements of a flexible approach for conceptual hydrological modeling: 2. Application and experimental insights

    NASA Astrophysics Data System (ADS)

    Kavetski, Dmitri; Fenicia, Fabrizio

    2011-11-01

    In this article's companion paper, flexible approaches for conceptual hydrological modeling at the catchment scale were motivated, and the SUPERFLEX framework, based on generic model components, was introduced. In this article, the SUPERFLEX framework and the "fixed structure" GR4H model (an hourly version of the popular GR4J model) are applied to four hydrologically distinct experimental catchments in Europe and New Zealand. The estimated models are scrutinized using several diagnostic measures, ranging from statistical metrics, such as the statistical reliability and precision of the predictive distribution of streamflow, to more process-oriented diagnostics based on flow-duration curves and the correspondence between model states and groundwater piezometers. Model performance was clearly catchment specific, with a single fixed structure unable to accommodate intercatchment differences in hydrological behavior, including seasonality and thresholds. This highlights an important limitation of any "fixed" model structure. In the experimental catchments, the ability of competing model hypotheses to reproduce hydrological signatures of interest could be interpreted on the basis of independent fieldwork insights. The potential of flexible frameworks such as SUPERFLEX is then examined with respect to systematic and stringent hypothesis-testing in hydrological modeling, for characterizing catchment diversity, and, more generally, for aiding progress toward a more unified formulation of hydrological theory at the catchment scale. When interpreted in physical process-oriented terms, the flexible approach can also serve as a language for dialogue between modeler and experimentalist, facilitating the understanding, representation, and interpretation of catchment behavior.

  18. 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.

  19. Intercomparisons between passive and active microwave remote sensing, and hydrological modeling for soil moisture

    NASA Technical Reports Server (NTRS)

    Wood, E. F.; Lin, D.-S.; Mancini, M.; Thongs, D.; Troch, P. A.; Jackson, T. J.; Famiglietti, J. S.; Engman, E. T.

    1993-01-01

    Soil moisture estimations from a distributed hydrological model and two microwave sensors were compared with ground measurements collected during the MAC-HYDRO'90 experiment. The comparison was done with the purpose of evaluating the performance of the hydrological model and examining the limitations of remote sensing techniques used in soil moisture estimation. An image integration technique was used to integrate and analyze rainfall, soil properties, land cover, topography, and remote sensing imagery. Results indicate that the hydrological model and microwave sensors successfully picked up temporal variations of soil moisture and that the spatial soil moisture pattern may be remotely sensed with reasonable accuracy using existing algorithms.

  20. 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.

  1. Addressing the Challenges of Distributed Hydrologic Modeling for Operational Forecasting

    NASA Astrophysics Data System (ADS)

    Butts, M. B.; Yamagata, K.; Kobor, J.; Fontenot, E.

    2008-05-01

    from flood modelling on the Odra River in Poland show that this model system can perform as well as traditional models and gives good predictions in mountainous catchments. By allowing different process representations to be applied within the same framework, it is possible to develop hydrological models in a phased manner. This phased approach was used for example in the Napa Valley, California where it is important to balance water demands for urban areas, agriculture, and ecosystem preservation while maintaining flood protection and water quality. A first regional model was developed with a detailed description of the surface process and a simple linear reservoir was used to simulate the groundwater component. Then a more detailed fully-distributed finite-difference groundwater model was constructed within the same framework while maintaining the surface water components. In the DMIP case study, Blue River, Oklahoma, this flexibility has been used to evaluate the performance of different model structures, and to determine the impact of grid resolution on model accuracy. The results show clear limits to the benefit attained by increasing model complexity and resolution. In contrast, detailed flood mapping using high resolution topography carried out with this tool in South Boulder Creek, Colorado show that very detailed description of the topography and flows paths are required for accurate flood mapping and determination of the flood risk. This framework is now being used to develop a flood forecasting system for the Big Cypress Basin in Florida.

  2. One-day offset in daily hydrologic modeling: An exploration of the issue in automatic model calibration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The literature of daily hydrologic modelling illustrates that daily simulation models are incapable of accurately representing hydrograph timing due to relationships between precipitation and watershed hydrologic response. For watersheds with a time of concentration less than 24 hrs and a late day p...

  3. Parsimonious Hydrologic and Nitrate Response Models For Silver Springs, Florida

    NASA Astrophysics Data System (ADS)

    Klammler, Harald; Yaquian-Luna, Jose Antonio; Jawitz, James W.; Annable, Michael D.; Hatfield, Kirk

    2014-05-01

    Silver Springs with an approximate discharge of 25 m3/sec is one of Florida's first magnitude springs and among the largest springs worldwide. Its 2500-km2 springshed overlies the mostly unconfined Upper Floridan Aquifer. The aquifer is approximately 100 m thick and predominantly consists of porous, fractured and cavernous limestone, which leads to excellent surface drainage properties (no major stream network other than Silver Springs run) and complex groundwater flow patterns through both rock matrix and fast conduits. Over the past few decades, discharge from Silver Springs has been observed to slowly but continuously decline, while nitrate concentrations in the spring water have enormously increased from a background level of 0.05 mg/l to over 1 mg/l. In combination with concurrent increases in algae growth and turbidity, for example, and despite an otherwise relatively stable water quality, this has given rise to concerns about the ecological equilibrium in and near the spring run as well as possible impacts on tourism. The purpose of the present work is to elaborate parsimonious lumped parameter models that may be used by resource managers for evaluating the springshed's hydrologic and nitrate transport responses. Instead of attempting to explicitly consider the complex hydrogeologic features of the aquifer in a typically numerical and / or stochastic approach, we use a transfer function approach wherein input signals (i.e., time series of groundwater recharge and nitrate loading) are transformed into output signals (i.e., time series of spring discharge and spring nitrate concentrations) by some linear and time-invariant law. The dynamic response types and parameters are inferred from comparing input and output time series in frequency domain (e.g., after Fourier transformation). Results are converted into impulse (or step) response functions, which describe at what time and to what magnitude a unitary change in input manifests at the output. For the

  4. Improving student comprehension of the interconnectivity of the hydrologic cycle with a novel 'hydrology toolbox', integrated watershed model, and companion textbook

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    Concepts in introductory hydrology courses are often taught in the context of process-based modeling that ultimately is integrated into a watershed model. In an effort to reduce the learning curve associated with applying hydrologic concepts to real-world applications, we developed and incorporated a 'hydrology toolbox' that complements a new, companion textbook into introductory undergraduate hydrology courses. The hydrology toolbox contains the basic building blocks (functions coded in MATLAB) for an integrated spatially-distributed watershed model that makes hydrologic topics (e.g. precipitation, snow, radiation, evaporation, unsaturated flow, infiltration, groundwater, and runoff) more user-friendly and accessible for students. The toolbox functions can be used in a modular format so that students can study individual hydrologic processes and become familiar with the hydrology toolbox. This approach allows such courses to emphasize understanding and application of hydrologic concepts rather than computer coding or programming. While topics in introductory hydrology courses are often introduced and taught independently or semi-independently, they are inherently interconnected. These toolbox functions are therefore linked together at the end of the course to reinforce a holistic understanding of how these hydrologic processes are measured, interconnected, and modeled. They are integrated into a spatially-distributed watershed model or numerical laboratory where students can explore a range of topics such as rainfall-runoff modeling, urbanization, deforestation, watershed response to changes in parameters or forcings, etc. Model output can readily be visualized and analyzed by students to understand watershed response in a real river basin or a simple 'toy' basin. These tools complement the textbook, each of which has been well received by students in multiple hydrology courses with various disciplinary backgrounds. The same governing equations that students have

  5. Application of remote sensing to hydrology. [for the formulation of watershed behavior models

    NASA Technical Reports Server (NTRS)

    Ambaruch, R.; Simmons, J. W.

    1973-01-01

    Streamflow forecasting and hydrologic modelling are considered in a feasibility assessment of using the data produced by remote observation from space and/or aircraft to reduce the time and expense normally involved in achieving the ability to predict the hydrological behavior of an ungaged watershed. Existing watershed models are described, and both stochastic and parametric techniques are discussed towards the selection of a suitable simulation model. Technical progress and applications are reported and recommendations are made for additional research.

  6. Effects of Uncertainties in Hydrological Modelling. A Case Study of a Mountainous Catchment in Southern Norway

    NASA Astrophysics Data System (ADS)

    Engeland, Kolbjorn; Steinsland, Ingelin

    2016-04-01

    The aim of this study is to investigate how the inclusion of uncertainties in inputs and observed streamflow influence the parameter estimation, streamflow predictions and model evaluation. In particular we wanted to answer the following research questions: • What is the effect of including a random error in the precipitation and temperature inputs? • What is the effect of decreased information about precipitation by excluding the nearest precipitation station? • What is the effect of the uncertainty in streamflow observations? • What is the effect of reduced information about the true streamflow by using a rating curve where the measurement of the highest and lowest streamflow is excluded when estimating the rating curve? To answer these questions, we designed a set of calibration experiments and evaluation strategies. We used the elevation distributed HBV model operating on daily time steps combined with a Bayesian formulation and the MCMC routine Dream for parameter inference. The uncertainties in inputs was represented by creating ensembles of precipitation and temperature. The precipitation ensemble were created using a meta-gaussian random field approach. The temperature ensembles were created using a 3D Bayesian kriging with random sampling of the temperature laps rate. The streamflow ensembles were generated by a Bayesian multi-segment rating curve model. Precipitation and temperatures were randomly sampled for every day, whereas the streamflow ensembles were generated from rating curve ensembles, and the same rating curve was always used for the whole time series in a calibration or evaluation run. We chose a catchment with a meteorological station measuring precipitation and temperature, and a rating curve of relatively high quality. This allowed us to investigate and further test the effect of having less information on precipitation and streamflow during model calibration, predictions and evaluation. The results showed that including uncertainty

  7. Using models for the optimization of hydrologic monitoring

    USGS Publications Warehouse

    Fienen, Michael N.; Hunt, Randall J.; Doherty, John E.; Reeves, Howard W.

    2011-01-01

    Hydrologists are often asked what kind of monitoring network can most effectively support science-based water-resources management decisions. Currently (2011), hydrologic monitoring locations often are selected by addressing observation gaps in the existing network or non-science issues such as site access. A model might then be calibrated to available data and applied to a prediction of interest (regardless of how well-suited that model is for the prediction). However, modeling tools are available that can inform which locations and types of data provide the most 'bang for the buck' for a specified prediction. Put another way, the hydrologist can determine which observation data most reduce the model uncertainty around a specified prediction. An advantage of such an approach is the maximization of limited monitoring resources because it focuses on the difference in prediction uncertainty with or without additional collection of field data. Data worth can be calculated either through the addition of new data or subtraction of existing information by reducing monitoring efforts (Beven, 1993). The latter generally is not widely requested as there is explicit recognition that the worth calculated is fundamentally dependent on the prediction specified. If a water manager needs a new prediction, the benefits of reducing the scope of a monitoring effort, based on an old prediction, may be erased by the loss of information important for the new prediction. This fact sheet focuses on the worth or value of new data collection by quantifying the reduction in prediction uncertainty achieved be adding a monitoring observation. This calculation of worth can be performed for multiple potential locations (and types) of observations, which then can be ranked for their effectiveness for reducing uncertainty around the specified prediction. This is implemented using a Bayesian approach with the PREDUNC utility in the parameter estimation software suite PEST (Doherty, 2010). The

  8. Socio-hydrological modelling: a review asking "why, what and how?"

    NASA Astrophysics Data System (ADS)

    Blair, P.; Buytaert, W.

    2016-01-01

    Interactions between humans and the environment are occurring on a scale that has never previously been seen; the scale of human interaction with the water cycle, along with the coupling present between social and hydrological systems, means that decisions that impact water also impact people. Models are often used to assist in decision-making regarding hydrological systems, and so in order for effective decisions to be made regarding water resource management, these interactions and feedbacks should be accounted for in models used to analyse systems in which water and humans interact. This paper reviews literature surrounding aspects of socio-hydrological modelling. It begins with background information regarding the current state of socio-hydrology as a discipline, before covering reasons for modelling and potential applications. Some important concepts that underlie socio-hydrological modelling efforts are then discussed, including ways of viewing socio-hydrological systems, space and time in modelling, complexity, data and model conceptualisation. Several modelling approaches are described, the stages in their development detailed and their applicability to socio-hydrological cases discussed. Gaps in research are then highlighted to guide directions for future research. The review of literature suggests that the nature of socio-hydrological study, being interdisciplinary, focusing on complex interactions between human and natural systems, and dealing with long horizons, is such that modelling will always present a challenge; it is, however, the task of the modeller to use the wide range of tools afforded to them to overcome these challenges as much as possible. The focus in socio-hydrology is on understanding the human-water system in a holistic sense, which differs from the problem solving focus of other water management fields, and as such models in socio-hydrology should be developed with a view to gaining new insight into these dynamics. There is an

  9. Modelling socio-hydrological systems: a review of concepts, approaches and applications

    NASA Astrophysics Data System (ADS)

    Blair, P.; Buytaert, W.

    2015-09-01

    Interactions between humans and the environment are occurring on a scale that has never previously been seen; one environmental facet that has seen particular co-evolution with society is water. The scale of human interaction with the water cycle, along with the coupling present between social and hydrological systems, means that decisions that impact water also impact people. Models are often used to assist in decision-making regarding hydrological systems, and so in order for effective decisions to be made regarding water resource management, these interactions and feedbacks should be accounted for in models used to analyse systems in which water and humans interact. This paper reviews literature surrounding aspects of socio-hydrological modelling. It begins with background information regarding the current state of socio-hydrology as a discipline, before covering reasons for modelling and potential applications. Some important concepts that underlie socio-hydrological modelling efforts are then discussed, including ways of viewing socio-hydrological systems, space and time in modelling, complexity, data and model conceptualisation. Several modelling approaches are described, the stages in their development detailed and their applicability to socio-hydrological cases discussed. Gaps in research are then highlighted to guide directions for future research. The review of literature suggests that the nature of socio-hydrological study, being interdisciplinary, focusing on complex interactions between human and natural systems, and dealing with long horizons, is such that modelling will always present a challenge; it is, however, the task of the modeller to use the wide range tools afforded to them to overcome these challenges as much as possible. The focus in socio-hydrology is on understanding the human-water system in a holistic sense, which differs from the problem solving focus of other water management fields, and as such models in socio-hydrology should be

  10. 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

  11. mRM - multiscale Routing Model for Land Surface and Hydrologic Models

    NASA Astrophysics Data System (ADS)

    Cuntz, M.; Thober, S.; Mai, J.; Samaniego, L. E.; Gochis, D. J.; Kumar, R.

    2015-12-01

    Routing streamflow through a river network is a basic step within any distributed hydrologic model. It integrates the generated runoff and allows comparison with observed discharge at the outlet of a catchment. The Muskingum routing is a textbook river routing scheme that has been implemented in Earth System Models (e.g., WRF-HYDRO), stand-alone routing schemes (e.g., RAPID), and hydrologic models (e.g., the mesoscale Hydrologic Model). Most implementations suffer from a high computational demand because the spatial routing resolution is fixed to that of the elevation model irrespective of the hydrologic modeling resolution. This is because the model parameters are scale-dependent and cannot be used at other resolutions without re-estimation. Here, we present the multiscale Routing Model (mRM) that allows for a flexible choice of the routing resolution. mRM exploits the Multiscale Parameter Regionalization (MPR) included in the open-source mesoscale Hydrologic Model (mHM, www.ufz.de/mhm) that relates model parameters to physiographic properties and allows to estimate scale-independent model parameters. mRM is currently coupled to mHM and is presented here as stand-alone Free and Open Source Software (FOSS). The mRM source code is highly modular and provides a subroutine for internal re-use in any land surface scheme. mRM is coupled in this work to the state-of-the-art land surface model Noah-MP. Simulation results using mRM are compared with those available in WRF-HYDRO for the Red River during the period 1990-2000. mRM allows to increase the routing resolution from 100m to more than 10km without deteriorating the model performance. Therefore, it speeds up model calculation by reducing the contribution of routing to total runtime from over 80% to less than 5% in the case of WRF-HYDRO. mRM thus makes discharge data available to land surface modeling with only little extra calculations.

  12. 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.

  13. On the Impact of Uncertainty in Initial Conditions of Hydrologic Models on Prediction

    NASA Astrophysics Data System (ADS)

    Razavi, S.; Sheikholeslami, R.

    2015-12-01

    Determining the initial conditions for predictive models remains a challenge due to the uncertainty in measurement/identification of the state variables at the scale of interest. However, the characterization of uncertainty in initial conditions has arguably attracted less attention compared with other sources of uncertainty in hydrologic modelling (e.g, parameter, data, and structural uncertainty). This is perhaps because it is commonly believed that: (1) hydrologic systems (relatively rapidly) forget their initial conditions over time, and (2) other sources of uncertainty (e.g., in data) are dominant. This presentation revisits the basic principles of the theory of nonlinear dynamical systems in the context of hydrologic systems. Through simple example case studies, we demonstrate how and under what circumstances different hydrologic processes represent a range of attracting limit sets in their evolution trajectory in state space over time, including fixed points, limit cycles (periodic behaviour), torus (quasi-periodic behaviour), and strange attractors (chaotic behaviour). Furthermore, the propagation (or dissipation) of uncertainty in initial conditions of several hydrologic models through time, under any of the possible attracting limit sets, is investigated. This study highlights that there are definite situations in hydrology where uncertainty in initial conditions remains of significance. The results and insights gained have important implications for hydrologic modelling under non-stationarity in climate and environment.

  14. 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.

  15. Development of hybrid 3-D hydrological modeling for the NCAR Community Earth System Model (CESM)

    SciTech Connect

    Zeng, Xubin; Troch, Peter; Pelletier, Jon; Niu, Guo-Yue; Gochis, David

    2015-11-15

    This is the Final Report of our four-year (3-year plus one-year no cost extension) collaborative project between the University of Arizona (UA) and the National Center for Atmospheric Research (NCAR). The overall objective of our project is to develop and evaluate the first hybrid 3-D hydrological model with a horizontal grid spacing of 1 km for the NCAR Community Earth System Model (CESM).

  16. Stepwise calibration procedure for regional coupled hydrological-hydrogeological models

    NASA Astrophysics Data System (ADS)

    Labarthe, Baptiste; Abasq, Lena; de Fouquet, Chantal; Flipo, Nicolas

    2014-05-01

    have been determined, the groundwater component is calibrated. The calibration procedure is performed under steady state hypothesis (to minimize the procedure time length) using recharge rates given by the surface component calibration and imposed fluxes boundary conditions given by the regional model. The calibration is performed using pilot point where the prior variogram is calculated from observed transmissivities values. This procedure uses PEST (http//:www.pesthomepage.org/Home.php) as the inverse modelling tool and EauDyssée as the direct model. During the stepwise calibration process, each modules, even if they are actually dependant from each other, are run and calibrated independently, therefore contributions between each module have to be determined. For the surface module, groundwater and runoff contributions have been determined by hydrograph separation. Among the automated base-flow separation methods, the one-parameter Chapman filter (Chapman et al 1999) has been chosen. This filter is a decomposition of the actual base-flow between the previous base-flow and the discharge gradient weighted by functions of the recession coefficient. For the groundwater module, the recharge has been determined from surface and sub-surface module. References : Flipo, N., A. Mourhi, B. Labarthe, and S. Biancamaria (2014). Continental hydrosystem modelling : the concept of nested stream-aquifer interfaces. Hydrol. Earth Syst. Sci. Discuss. 11, 451-500. Chapman,TG. (1999). A comparison of algorithms for stream flow recession and base-flow separation. hydrological Processes 13, 701-714.

  17. Comparison between fully distributed model and semi-distributed model in urban hydrology modeling

    NASA Astrophysics Data System (ADS)

    Ichiba, Abdellah; Gires, Auguste; Giangola-Murzyn, Agathe; Tchiguirinskaia, Ioulia; Schertzer, Daniel; Bompard, Philippe

    2013-04-01

    Water management in urban areas is becoming more and more complex, especially because of a rapid increase of impervious areas. There will also possibly be an increase of extreme precipitation due to climate change. The aims of the devices implemented to handle the large amount of water generate by urban areas such as storm water retention basins are usually twofold: ensure pluvial flood protection and water depollution. These two aims imply opposite management strategies. To optimize the use of these devices there is a need to implement urban hydrological models and improve fine-scale rainfall estimation, which is the most significant input. In this paper we suggest to compare two models and their sensitivity to small-scale rainfall variability on a 2.15 km2 urban area located in the County of Val-de-Marne (South-East of Paris, France). The average impervious coefficient is approximately 34%. In this work two types of models are used. The first one is CANOE which is semi-distributed. Such models are widely used by practitioners for urban hydrology modeling and urban water management. Indeed, they are easily configurable and the computation time is reduced, but these models do not take fully into account either the variability of the physical properties or the variability of the precipitations. An alternative is to use distributed models that are harder to configure and require a greater computation time, but they enable a deeper analysis (especially at small scales and upstream) of the processes at stake. We used the Multi-Hydro fully distributed model developed at the Ecole des Ponts ParisTech. It is an interacting core between open source software packages, each of them representing a portion of the water cycle in urban environment. Four heavy rainfall events that occurred between 2009 and 2011 are analyzed. The data comes from the Météo-France radar mosaic and the resolution is 1 km in space and 5 min in time. The closest radar of the Météo-France network is

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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 developed, accurate hydrologic information in all of its components including socio-economy, atmosphere, land, and energy infrastructure is needed to represent the interactions between human and earth system processes. Applying CLM in this framework requires evaluation and model improvement so that CLM could be used to represent hydrology, soil, managed and unmanaged ecosystems, and biogeochemical processes across scales in a single modeling framework. In this presentation, we will report preliminary results on the development of CLM featuring: (1) improved land surface hydrology that incorporates hydrologic processes from the Variable Infiltration Capacity (VIC) land surface model, including the parameterizations of subgrid variability, dynamic surface- and groundwater interactions, and hydraulic redistribution; (2) a semi-distributed extension of CLM (DCLM) for more spatially-explicit hydrologic modeling, which is critical for regional land and water management decisions under climate change mitigation and adaptation scenarios. The model development will be evaluated at flux towers and watersheds at various scales.

  19. Open Source assimilation tool for distributed hydrological model

    NASA Astrophysics Data System (ADS)

    Richard, Julien; Giangola-Murzyn, Agathe; Tchiguirinskaia, Ioulia; Schertzer, Daniel

    2013-04-01

    An advanced GIS data assimilation interface is a requisite to obtain a distributed hydrological model that is both transportable from catchment to catchment and is easily adaptable to data resolution. This tool is achieved for the cartographic data as well as the linked information data. In the case of the Multi-Hydro-Version2 model (A. Giangola-Murzyn et al. 2012), several types of information are distributed on a regular grid. The grid cell size has to be chosen by the user and each cell has to be filled up with information. In order to be the most realistic as possible, the Multi-Hydro model takes into account several data. For that, the assimilation tool (MH-AssimTool) has to be able to import all these different information. The needed flexibility of the studied area and grid size requires that the GIS interface must be easy to take in hand and also practical. The solution of a main window for the geographical visualisation and hierarchical menus coupled with checkboxes was chosen. For example, the geographical information, like the topography or the land use can be visualized in the main window. For the other data, like the soil conductivity, the geology or the initial moisture, the information is demanded through several pop-up windows. Once the needed information imported, MH-AssimTool prepares automatically the data. For the topography data conversion, if the resolution is too small, an interpolation is done during the processing. As a result, all the converted data is in a good resolution for the modelling. As Multi-Hydro, MH-AssimTool is open source. It's coded in Visual Basic language coupled with a GIS library. The interface is built in such a way then it can be used by a non specialist. We will illustrate the efficiency of the tool with some case studies of peri-urban catchments of widely different sizes and characteristics. We will also explain some parts of the coding of the interface.

  20. 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.

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

    USGS Publications Warehouse

    Milly, Paul C.D.; 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.

  2. DECO - Extracting and converting meteorological driving data for hydrological models via a web-based platform

    NASA Astrophysics Data System (ADS)

    Richling, Andy; Fischer, Madlen; Rust, Henning W.; Kadow, Christopher; Vagenas, Christos; Ulbrich, Uwe

    2016-04-01

    Climate change impact assessment for hydrology and related water resource management is based on global climate projections, their regional downscaling and the subsequent use of this data in hydrological models. While global climate projections, as well as regional downscaled data are relatively easily available due to the CMIP and CORDEX activities, it cost some effort to prepare this data for use with hydrological models. This implies several steps: a change of grid or transformation to gauge based values, a bias correction and a conversion to the file format from climate model standards to a format accessible by the hydrological model. In BINGO, we developed the plug-in DECO for the web-based (also command line interface) evaluation platform FreVa (http://freva.met.fu-berlin.de) to search and extract climate data, post-process and convert it to the required output format. As far as possible, all post-processing steps are identical for all models at all BINGO research sites to ensure comparability; the research site and model specific file format conversion has been implemented for all hydrological models to be used. This approach ensures that post-processing (bias correction, grid conversion, etc.) are identical for all sites and are tested by a large community; data extraction is easily reproducible and and new data set injected into the FreVa data pool can be readily extracted and converted for timely use with hydrological models. Apart from transparency and reproducibility, this approach allows the timely conversion of new (downscaled) climate projections to hydrological application and may serve as an example for data dissemination within the hydrological modeling community.

  3. Comparisons of regional Hydrological Angular Momentum (HAM) of the different models

    NASA Astrophysics Data System (ADS)

    Nastula, J.; Kolaczek, B.; Popinski, W.

    2006-10-01

    In the paper hydrological excitations of the polar motion (HAM) were computed from various hydrological data series (NCEP, ECMWF, CPC water storage and LaD World Simulations of global continental water). HAM series obtained from these four models and the geodetic excitation function GEOD computed from the polar motion COMB03 data were compared in the seasonal spectral band. The results show big differences of these hydrological excitation functions as well as of their spectra in the seasonal spectra band. Seasonal oscillations of the global geophysical excitation functions (AAM + OAM + HAM) in all cases besides the NCEP/NCAR model are smaller than the geodetic excitation function. It means that these models need further improvement and perhaps not only hydrological models need improvements.

  4. Hydrological and pesticide transfer modeling in a tropical volcanic watershed with the WATPPASS model

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    Simulation of flows and pollutant transfers in heterogeneous media is widely recognized to be a remaining frontier in hydrology research. We present a new modeling approach to simulate agricultural pollutions in watersheds: WATPPASS, a model for Watershed Agricultural Techniques and Pesticide Practices ASSessment. It is designed to assess mean pesticide concentrations and loads that result from the use of pesticides in horticultural watersheds located on heterogeneous subsoil. WATPPASS is suited for small watershed with significant groundwater flows and complex aquifer systems. The model segments the watershed into fields with independent hydrological and pesticide transfers at the ground surface. Infiltrated water and pesticides are routed toward outlet using a conceptual reservoir model. We applied WATPPASS on a heterogeneous tropical volcanic watershed of Martinique in the French West Indies. We carried out and hydrological analysis that defined modeling constraints: (i) a spatial variability of runoff/infiltration partitioning according to land use, and (ii) a predominance of groundwater flow paths in two overlapping aquifers under permeable soils (50-60% of annual flows). We carried out simulations on a 550 days period at a daily time step for hydrology (Nashsqrt > 0.75). Weekly concentrations and loads of a persistent organic pesticide (chlordecone) were simulated for 67 weeks to evaluate the modeling approach. Pesticide simulations without specific calibration detected the mean long-term measured concentration, leading to a good quantification of the cumulative loads (5% error), but failed to represent the concentration peaks at the correct timing. Nevertheless, we succeed in adjusting the model structure to better represent the temporal dynamic of pesticide concentrations. This modification requires a proper evaluation on an independent dataset. Finally, WATPPASS is a compromise between complexity and easiness of use that makes it suited for cropping system

  5. On the hydrological performance in preparation for fully coupled climate-hydrology modelling in a data-sparse region

    NASA Astrophysics Data System (ADS)

    Dahl Larsen, Morten Andreas; Senatore, Alfonso; Drews, Martin; Mendicino, Giuseppe

    2016-04-01

    Within the recently emerging field of research employing a dynamical coupling between existing advanced atmosphere-hydrology model codes lays a demand for a wide range of data. The data are needed to both drive and validate the models and need to be of a high quality in terms of spatial coverage, temporal resolution, representation of local attributes and data selection. As a consequence, most studies have been performed over regions of vast data coverage. Although good data coverage is mainly seen in regions of more economically developed countries, the advantages of the coupled models could be of at least equal relevance in lesser developed regions. We here evaluate the prediction capabilities of the joint MIKE SHE-SWET hydrology and land surface model which has recently been employed in a dynamical coupling with the HIRHAM regional climate model (RCM). As a test case, we use the Crati River catchment in Southern Italy. The catchment is used due to: 1) A reasonable availability of data in terms of discharge, a flux tower station, climate stations and gridded data products such as ERA-I, E-OBS, SWBM and RCM output (e.g. MED-CORDEX) albeit with problems resembling those of data sparse regions (lack of temporal overlap, gap filling, availability, hydrogeological interpretations and land use). 2) The location (the Mediterranean) has previously been shown to exhibit substantial biases which potentially could be reduced the future coupling. 3) The Mediterranean highlands with large variations in orography provide an interesting test case as this is poorly represented in models. And 4) Model runs using the WRF-Hydro model have been performed enabling the basis for valuable comparison studies. In the present study the model is parameterized through inverse calibration using variations of the available data to highlight the influence of data quality and availability on the model outcome and assets/disadvantages of individual products.

  6. Evaluating catchment-scale hydrological modeling by means of terrestrial gravity observations

    NASA Astrophysics Data System (ADS)

    Hasan, Shaakeel; Troch, Peter A.; Bogaart, Patrick W.; Kroner, Corinna

    2008-08-01

    In a previous study (Hasan et al., 2006) we applied time series analysis and distributed hydrological modeling techniques to investigate the effect of hydrological processes on observed terrestrial gravity residuals. In this study we apply terrestrial gravity observations (measured in one location) to constrain simple hydrological models in a catchment around the gravimeter. A superconducting gravimeter observes with high frequency (1 Hz) the temporal variations in the gravity field with high accuracy (sub nm s-2 for hourly variation) near Moxa, Germany since 1999. Hourly gravity residuals are derived by filtering and reducing for Earth tides, polar motion, barometric pressure variations, and instrumental drift. These gravity residuals show significant response to hydrological processes (precipitation, evaporation, surface and subsurface flow) in the catchment surrounding the observatory. We can thus consider the observed gravity change as an integrator of catchment-scale hydrological response (similar in nature as discharge measurements), and therefore use it to constrain catchment-scale hydrologic models. We test a set of simple water balance models against measured discharge, and employ observed gravity residuals to evaluate model parameters. Results indicate that a lumped water balance model for unsaturated storage and fluxes, coupled with a semidistributed hydraulic groundwater model for saturated storage and fluxes, successfully reproduces both gravity and discharge dynamics.

  7. Land surface hydrology parameterization for atmospheric general circulation models including subgrid scale spatial variability

    NASA Technical Reports Server (NTRS)

    Entekhabi, D.; Eagleson, P. S.

    1989-01-01

    Parameterizations are developed for the representation of subgrid hydrologic processes in atmospheric general circulation models. Reasonable a priori probability density functions of the spatial variability of soil moisture and of precipitation are introduced. These are used in conjunction with the deterministic equations describing basic soil moisture physics to derive expressions for the hydrologic processes that include subgrid scale variation in parameters. The major model sensitivities to soil type and to climatic forcing are explored.

  8. 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

  9. Modelling Spatial Hydrologic Patterns Using Physically-Based Models Driven by Remote- Sensing and Reanalysis Data

    NASA Astrophysics Data System (ADS)

    Liu, M.; Bardossy, A.

    2008-12-01

    Due to the interaction with energy inputs (solar radiation, precipitation, and wind, etc.), natural catchments tend to evolve to an equilibrium state characterized by stable spatial patterns of vegetation, topography, soil distribution and river system, which in turn lead to stable patterns of certain hydrological variables, i.e., soil moisture, evapotranspiration, and snow cover. In this work, these three important hydrologic parameters have been investigated at a fine scale (500m to 1000m). The authors start from obtaining the spatial patterns of basic meteorological inputs with physically based models driven by globally available data, i.e., spatial solar radiation is generated by radiation models, and spatial wind is obtained by a meso-scale meteorological model driven by NCEP/NCAR reanalysis data. The SWAP model has been adapted to calculate the evapotranspiration and soil moisture at grid scale. The approach is validated in SADC (Southern African Development Community) region with the remote sensing soil moisture data available from ESA TIGER Innovator project. In a parallel study, MODIS snow cover data has been reconstructed applying a spatial and temporal filter with land surface temperature as auxiliary information, to investigate the characteristics of its spatial distribution. In both studies, statistical analysis reveals a strong relationship between the hydrological variables and topography, as well as land cover. Since the approach is based on physically based models and driven by globally available data, it is general for any catchment and time period.

  10. Analysis of the spatial discretization modeling watershed using the hydrology distributed model CEQUEAU

    NASA Astrophysics Data System (ADS)

    Guerra-Cobián, V. H.; Ba, K. M.; Díaz-Delgado, C.; Quentin, E.; Carsteanu, A. A.; Salas-Limón, D.

    2009-04-01

    Today, the use of hydrological models is essential, since they can be used to analyze various aspects such as runoff, flooding, the operation of dams and supply systems, water use, and use and protection of groundwater. In this research, we examined the effect on the spatial variation of the discretization in sixteen watersheds on distributed hydrological model simulations CEQUEAU. The overall objective was to propose criteria for determining the optimum size of mesh for the watershed discretization. The main methodological steps that were undertaken focused on the selection of hydrometric stations, the creation of hydrometeorlogical databases through the acquisition and adaptation of geodata. Furthermore, within the framework of research, we developed a new hydrogeomatic module that works in GIS Idrisi, which was part of the information used in hydrological modeling. The model CEQUEAU was performed in watershed study, using the Nash criterion for evaluating the results of simulations. Finally, statistical analysis was performed of the results, to propose criteria to determine the optimal size of mesh. The results of the analysis of spatial discretization were broadly satisfactory, because, in the simulations were obtained on average Nash coefficient between 0.6538 and 0.9823. The application of statistical techniques to the results of the analysis of spatial discretization, there were two multiple linear regression models with R2 values for each of 0.780 and 0.817. These equations obtained can be used as a criterion for determining the optimum size of spatial discretization watershed.

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

    SciTech Connect

    Naz, Bibi S; Frans, Chris; Clarke, Garry; Burns,; Lettenmaier, Dennis

    2014-01-01

    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.

  12. Physically based hydrologic modeling: 1. A terrain-based model for investigative purposes

    NASA Astrophysics Data System (ADS)

    Grayson, Rodger B.; Moore, Ian D.; McMahon, Thomas A.

    1992-10-01

    THALES, a simple distributed parameter hydrologic model is presented and applied to two catchments in Australia and the United States, each with different dominant hydrologic responses. The model simulates Hortonian overland flow and runoff from saturated source areas and is used to identify some of the barriers to modeling the hydrology of small catchments. At Wagga Wagga in New South Wales, Australia, runoff is produced from saturated source areas, whereas on the Lucky Hills catchments at Walnut Gulch in Arizona, Hortonian overland flow processes dominate. Simulations at Wagga Wagga are based on published parameters and field data measured as part of an intensive field program and result in a relatively poor fit of the outflow hydrographs for a series of storms. The simulated position and growth of saturated areas coincides with the limited available information, indicating that at least the gross effects of subsurface water movement are being represented. For the Lucky Hills catchments, the hydrographs at the catchment outlet and points within the catchment are simulated for a storm series. The results are highly dependent on the parameter values, which are poorly defined, highlighting the lack of measured field data and lack of methodology for the collection of data at a scale appropriate for such models. The model structure is also shown to have a major influence on the output. The influence of simulating surface flow as sheet flow or rill flow or through a series of ephemeral gullies, as well as the choice of the surface roughness parameter and antecedent soil water conditions, is shown to have a profound effect on the distributed flow depth and velocity predictions. By fitting model parameters, a simulation assuming Hortonian overland flow produced similar results at the catchment outlet to those based on partial area runoff. These results are of concern since it is common to calibrate and verify hydrologic models based on the accuracy with which the

  13. 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

  14. Develop hydrological relationships using a modeling approach in Mississippi delta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agriculture management practices such as tillage and crop rotations alter the hydrological budget of watersheds. Changes happen to surface runoff can be easily identify with the help of intensive USGS stream gage network, available in Mississippi, but changes to ground water table is less understood...

  15. Rangeland Hydrology and Erosion Model (RHEM) for ESD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA-Natural Resources Conservation Service (NRCS) is currently engaged in updating and writing new ecological Site Descriptions (ESD’s). New and updated information about physiographic, soil, climate, and water features; plant communities—including “state and transition models”; and hydrology ...

  16. 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

  17. Sensitivity of Extreme Hydrological Events to Spatial Resolution of Climate Forcings using a Macro-Scale Hydrologic Model

    NASA Astrophysics Data System (ADS)

    Naz, B. S.; Kao, S. C.; Ashfaq, M.; Rastogi, D.; Mei, R.; Gangrade, S.

    2015-12-01

    The magnitude and frequency of hydrometeorological extremes are expected to increase in the conterminous United States over the coming century with significant implications for future water resource planning. However, future changes in the frequency and severity of extreme hydrological events is highly uncertain, in part because of under representation of fine scale topographic and weather features in the continental- to global-scale models. In this study, the influence of spatial resolution on both extremes (floods and droughts) and mean hydrologic conditions is investigated using the macro-scale Variable Infiltration Capacity (VIC) model, implemented and calibrated at 1/24th degree grid cell (~4km) resolution. The coarser resolution simulations are achieved by averaging the 1/24o forcing data to 1/8o which is then used to drive the VIC model. To investigate the sensitivity of simulated high and low runoff conditions to changes in precipitation and temperature at different spatial resolution, further simulations are conducted by (a) increasing both historic maximum and minimum daily temperature by 1° C, (b) increasing historic precipitation by 10%, and (c) decreasing historic precipitation by 10%. The results are further analyzed for various types of extreme precipitation events across different watershed scales and for different regions representing a variety of hydrometeorological characteristics. This work helps us to understand the sensitivity of runoff to spatial resolution of climate forcings and also its sensitivity to different watershed sizes and characteristics of extreme precipitation events in the future climate conditions.

  18. Introduction of LL-IV Distributed Hydrological Model and Applications in DMIP-II

    NASA Astrophysics Data System (ADS)

    Li, L.; Zhang, H.; Yang, M.; Nicholson, A.

    2011-12-01

    Watershed hydrological models are an important tool for understanding hydrological processes on the earth, and they have been developed from empirical models to stochastic models, to lumped conceptual models, and finally to distributed conceptual models. Among them, the distributed hydrological model with physical bases is a great milestone in the development of hydrological models. The Hydrology Laboratory of the US National Weather Service paid high attention to the applications of distributed hydrological models. This department has proposed the Distributed Model Intercomparison Projects (DMIP-I and DMIP-II) since 2001, which made a major contribution to the development of distributed hydrological models. This paper introduces the development of the LL (Lan Li) distributed hydrological model, which produced satisfactory results in both DMIP-I and DIMP-II. LL-IV is the latest version of the LL distributed hydrological model and its basic equations and structures are detailed in this paper. LL-IV, for the first time, derives convection-diffusion equations for the interflow (in both saturated and unsaturated conditions) and underground flow. In addition, this model describes soil humidity, evaporation from soil, infiltration, overland flow, stream flow etc. by convection-diffusion equations. The advantages of using convection-diffusion equations in LL-IV to represent water cycle process for either the vertical change in a single grid or water interchange between grids are as follows: (1) Convection-diffusion equations require fewer variables compared with St. Venant equations. Whole and continuous data of the velocity and water stage, for example, are not usually available for most watersheds, which limits the application of distributed hydrological model. For LL-IV, however, these data are not always necessary when simulating. (2) LL-IV improves computational efficiency and requires less memory space by using convection-diffusion equations which focus mainly on

  19. A Distributed Biosphere-Hydrological Model System for Continental Scale River Basins

    NASA Astrophysics Data System (ADS)

    Tang, Q.; Oki, T.; Kanae, S.; Hu, H.

    2006-12-01

    A new generation hydrological model, Distributed Biosphere-Hydrological (DBH) Model, is developed to connect hydrological cycle with biosphere, climate system and human society. The vegetated surface is calculated by a realistic land surface model SiB2. The hydrological part estimates the surface runoff and calculates the interlayer exchanges and interaction between soil water and groundwater. It physically represents hydrological cycle with the support of nontraditional datasets. With the new generation model, the scope of hydrology will broaden from rainfall-runoff relationship to climatology, biosphere, ecosystem, remote sensing, and human society. The model can demonstrate the effects of natural and anthropogenic heterogeneity on hydrological cycle. The effects on hydrological responses of precipitation variability and the variability on irrigation redistributing runoff, was investigated. Runoff is underestimated if the rainfall is spatially uniformly put on large grid cell. Runoff simulation could be improved by taking into account the precipitation heterogeneity. However, the negative runoff contribution cannot be simulated by only considering the natural heterogeneity. This constructive model shortcoming can be eliminated by taking into account anthropogenic heterogeneity. The model is used to interpret the Yellow River drying up phenomenon in China. Scenarios are performed from 1960 to 2000 to quantify the effect of human activity, and to distinguish it from the effect from climate change. The results show climate change is dominated in the upper and middle reaches, and human activity is dominated in the lower reaches. The river discharge nearly half is affected by climate change and half by human activities. Climate pattern change rather than linear change contributes to the decrease of stream flow in the Yellow River.

  20. Pursuing realistic hydrologic model under SUPERFLEX framework in a semi-humid catchment in China

    NASA Astrophysics Data System (ADS)

    Wei, Lingna; Savenije, Hubert H. G.; Gao, Hongkai; Chen, Xi

    2016-04-01

    Model realism is pursued perpetually by hydrologists for flood and drought prediction, integrated water resources management and decision support of water security. "Physical-based" distributed hydrologic models are speedily developed but they also encounter unneglectable challenges, for instance, computational time with low efficiency and parameters uncertainty. This study step-wisely tested four conceptual hydrologic models under the framework of SUPERFLEX in a small semi-humid catchment in southern Huai River basin of China. The original lumped FLEXL has hypothesized model structure of four reservoirs to represent canopy interception, unsaturated zone, subsurface flow of fast and slow components and base flow storage. Considering the uneven rainfall in space, the second model (FLEXD) is developed with same parameter set for different rain gauge controlling units. To reveal the effect of topography, terrain descriptor of height above the nearest drainage (HAND) combined with slope is applied to classify the experimental catchment into two landscapes. Then the third one (FLEXTOPO) builds different model blocks in consideration of the dominant hydrologic process corresponding to the topographical condition. The fourth one named FLEXTOPOD integrating the parallel framework of FLEXTOPO in four controlled units is designed to interpret spatial variability of rainfall patterns and topographic features. Through pairwise comparison, our results suggest that: (1) semi-distributed models (FLEXD and FLEXTOPOD) taking precipitation spatial heterogeneity into account has improved model performance with parsimonious parameter set, and (2) hydrologic model architecture with flexibility to reflect perceived dominant hydrologic processes can include the local terrain circumstances for each landscape. Hence, the modeling actions are coincided with the catchment behaviour and close to the "reality". The presented methodology is regarding hydrologic model as a tool to test our

  1. Marrying Hydrological Modelling and Integrated Assessment for the needs of Water Resource Management

    NASA Astrophysics Data System (ADS)

    Croke, B. F. W.; Blakers, R. S.; El Sawah, S.; Fu, B.; Guillaume, J. H. A.; Kelly, R. A.; Patrick, M. J.; Ross, A.; Ticehurst, J.; Barthel, R.; Jakeman, A. J.

    2014-09-01

    This paper discusses the integration of hydrology with other disciplines using an Integrated Assessment (IA) and modelling approach to the management and allocation of water resources. Recent developments in the field of socio-hydrology aim to develop stronger relationships between hydrology and the human dimensions of Water Resource Management (WRM). This should build on an existing wealth of knowledge and experience of coupled human-water systems. To further strengthen this relationship and contribute to this broad body of knowledge, we propose a strong and durable "marriage" between IA and hydrology. The foundation of this marriage requires engagement with appropriate concepts, model structures, scales of analyses, performance evaluation and communication - and the associated tools and models that are needed for pragmatic deployment or operation. To gain insight into how this can be achieved, an IA case study in water allocation in the Lower Namoi catchment, NSW, Australia is presented.

  2. Improved ground hydrology calculations for global climate models (GCMs) - Soil water movement and evapotranspiration

    NASA Technical Reports Server (NTRS)

    Abramopoulos, F.; Rosenzweig, C.; Choudhury, B.

    1988-01-01

    A physically based ground hydrology model is presented that includes the processes of transpiration, evaporation from intercepted precipitation and dew, evaporation from bare soil, infiltration, soil water flow, and runoff. Data from the Goddard Institute for Space Studies GCM were used as inputs for off-line tests of the model in four 8 x 10 deg regions, including Brazil, Sahel, Sahara, and India. Soil and vegetation input parameters were caculated as area-weighted means over the 8 x 10 deg gridbox; the resulting hydrological quantities were compared to ground hydrology model calculations performed on the 1 x 1 deg cells which comprise the 8 x 10 deg gridbox. Results show that the compositing procedure worked well except in the Sahel, where low soil water levels and a heterogeneous land surface produce high variability in hydrological quantities; for that region, a resolution better than 8 x 10 deg is needed.

  3. Consistency between hydrological models and field observations: Linking processes at the hillslope scale to hydrological responses at the watershed scale

    USGS Publications Warehouse

    Clark, M.P.; Rupp, D.E.; Woods, R.A.; Tromp-van, Meerveld; Peters, N.E.; Freer, J.E.

    2009-01-01

    The purpose of this paper is to identify simple connections between observations of hydrological processes at the hillslope scale and observations of the response of watersheds following rainfall, with a view to building a parsimonious model of catchment processes. The focus is on the well-studied Panola Mountain Research Watershed (PMRW), Georgia, USA. Recession analysis of discharge Q shows that while the relationship between dQ/dt and Q is approximately consistent with a linear reservoir for the hillslope, there is a deviation from linearity that becomes progressively larger with increasing spatial scale. To account for these scale differences conceptual models of streamflow recession are defined at both the hillslope scale and the watershed scale, and an assessment made as to whether models at the hillslope scale can be aggregated to be consistent with models at the watershed scale. Results from this study show that a model with parallel linear reservoirs provides the most plausible explanation (of those tested) for both the linear hillslope response to rainfall and non-linear recession behaviour observed at the watershed outlet. In this model each linear reservoir is associated with a landscape type. The parallel reservoir model is consistent with both geochemical analyses of hydrological flow paths and water balance estimates of bedrock recharge. Overall, this study demonstrates that standard approaches of using recession analysis to identify the functional form of storage-discharge relationships identify model structures that are inconsistent with field evidence, and that recession analysis at multiple spatial scales can provide useful insights into catchment behaviour. Copyright ?? 2008 John Wiley & Sons, Ltd.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  5. Coupling socio-economic factors and eco-hydrological processes using a cascade-modeling approach

    NASA Astrophysics Data System (ADS)

    Odongo, V. O.; Mulatu, D. W.; Muthoni, F. K.; van Oel, P. R.; Meins, F. M.; van der Tol, C.; Skidmore, A. K.; Groen, T. A.; Becht, R.; Onyando, J. O.; van der Veen, A.

    2014-10-01

    Most hydrological studies do not account for the socio-economic influences on eco-hydrological processes. However, socio-economic developments often change the water balance substantially and are highly relevant in understanding changes in hydrological responses. In this study a multi-disciplinary approach was used to study the cascading impacts of socio-economic drivers of land use and land cover (LULC) changes on the eco-hydrological regime of the Lake Naivasha Basin. The basin has recently experienced substantial LULC changes exacerbated by socio-economic drivers. The simplified cascade models provided insights for an improved understanding of the socio-ecohydrological system. Results show that the upstream population has transformed LULC such that runoff during the period 1986-2010 was 32% higher than during the period 1961-1985. Cut-flower export volumes and downstream population growth explain 71% of the water abstracted from Lake Naivasha. The influence of upstream population on LULC and upstream hydrological processes explained 59% and 30% of the variance in lake storage volumes and sediment yield respectively. The downstream LULC changes had significant impact on large wild herbivore mammal species on the fringe zone of the lake. This study shows that, in cases where observed socio-economic developments are substantial, the use of a cascade-modeling approach, that couple socio-economic factors to eco-hydrological processes, can greatly improve our understanding of the eco-hydrological processes of a catchment.

  6. Improving evapotranspiration processes in distrubing hydrological models using Remote Sensing derived ET products.

    NASA Astrophysics Data System (ADS)

    Abitew, T. A.; van Griensven, A.; Bauwens, W.

    2015-12-01

    Evapotranspiration is the main process in hydrology (on average around 60%), though has not received as much attention in the evaluation and calibration of hydrological models. In this study, Remote Sensing (RS) derived Evapotranspiration (ET) is used to improve the spatially distributed processes of ET of SWAT model application in the upper Mara basin (Kenya) and the Blue Nile basin (Ethiopia). The RS derived ET data is obtained from recently compiled global datasets (continuously monthly data at 1 km resolution from MOD16NBI,SSEBop,ALEXI,CMRSET models) and from regionally applied Energy Balance Models (for several cloud free days). The RS-RT data is used in different forms: Method 1) to evaluate spatially distributed evapotransiration model resultsMethod 2) to calibrate the evotranspiration processes in hydrological modelMethod 3) to bias-correct the evapotranpiration in hydrological model during simulation after changing the SWAT codesAn inter-comparison of the RS-ET products shows that at present there is a significant bias, but at the same time an agreement on the spatial variability of ET. The ensemble mean of different ET products seems the most realistic estimation and was further used in this study.The results show that:Method 1) the spatially mapped evapotranspiration of hydrological models shows clear differences when compared to RS derived evapotranspiration (low correlations). Especially evapotranspiration in forested areas is strongly underestimated compared to other land covers.Method 2) Calibration allows to improve the correlations between the RS and hydrological model results to some extent.Method 3) Bias-corrections are efficient in producing (sesonal or annual) evapotranspiration maps from hydrological models which are very similar to the patterns obtained from RS data.Though the bias-correction is very efficient, it is advised to improve the model results by better representing the ET processes by improved plant/crop computations, improved

  7. On the prediction of the Toce alpine basin floods with distributed hydrologic models

    NASA Astrophysics Data System (ADS)

    Montaldo, Nicola; Ravazzani, Giovanni; Mancini, Marco

    2007-02-01

    With the objective of improving flood predictions, in recent years sophisticated continuous hydrologic models that include complex land-surface sub-models have been developed. This has produced a significant increase in parameterization; consequently, applications of distributed models to ungauged basins lacking specific data from field campaigns may become redundant.The objective of this paper is to produce a parsimonious and robust distributed hydrologic model for flood predictions in Italian alpine basins. Application is made to the Toce basin (area 1534 km2). The Toce basin was a case study of the RAPHAEL European Union research project, during which a comprehensive set of hydrologic, meteorological and physiographic data were collected, including the hydrologic analysis of the 1996-1997 period. Two major floods occurred during this period. We compare the FEST04 event model (which computes rainfall abstraction and antecedent soil moisture conditions through the simple Soil Conservation Service curve number method) and two continuous hydrologic models, SDM and TDM (which differ in soil water balance scheme, and base flow and runoff generation computations).The simple FEST04 event model demonstrated good performance in the prediction of the 1997 flood, but shows limits in the prediction of the long and moderate 1996 flood. More robust predictions are obtained with the parsimonious SDM continuous hydrologic model, which uses a simple one-layer soil water balance model and an infiltration excess mechanism for runoff generation, and demonstrates good performance in both long-term runoff modelling and flood predictions. Instead, the use of a more sophisticated continuous hydrologic model, the TDM, that simulates soil moisture dynamics in two layers of soil, and computes runoff and base flow using some TOPMODEL concepts, does not seem to be advantageous for this alpine basin. Copyright

  8. Hydrological storage variations in a lake water balance, observed from multi-sensor satellite data and hydrological models.

    NASA Astrophysics Data System (ADS)

    Singh, Alka; Seitz, Florian; Schwatke, Christian; Guentner, Andreas

    2013-04-01

    Freshwater lakes and reservoirs account for 74.5% of continental water storage in surface water bodies and only 1.8% resides in rivers. Lakes and reservoirs are a key component of the continental hydrological cycle but in-situ monitoring networks are very limited either because of sparse spatial distribution of gauges or national data policy. Monitoring and predicting extreme events is very challenging in that case. In this study we demonstrate the use of optical remote sensing, satellite altimetry and the GRACE gravity field mission to monitor the lake water storage variations in the Aral Sea. Aral Sea is one of the most unfortunate examples of a large anthropogenic catastrophe. The 4th largest lake of 1960s has been decertified for more than 75% of its area due to the diversion of its primary rivers for irrigation purposes. Our study is focused on the time frame of the GRACE mission; therefore we consider changes from 2002 onwards. Continuous monthly time series of water masks from Landsat satellite data and water level from altimetry missions were derived. Monthly volumetric variations of the lake water storage were computed by intersecting a digital elevation model of the lake with respective water mask and altimetry water level. With this approach we obtained volume from two independent remote sensing methods to reduce the error in the estimated volume through least square adjustment. The resultant variations were then compared with mass variability observed by GRACE. In addition, GARCE estimates of water storage variations were compared with simulation results of the Water Gap Hydrology Model (WGHM). The different observations from all missions agree that the lake reached an absolute minimum in autumn 2009. A marked reversal of the negative trend occured in 2010 but water storage in the lake decreased again afterwards. The results reveal that water storage variations in the Aral Sea are indeed the principal, but not the only contributor to the GRACE signal of

  9. The role of hydrological modelling uncertainties in climate change impact assessments of Irish river catchments

    NASA Astrophysics Data System (ADS)

    Bastola, Satish; Murphy, Conor; Sweeney, John

    2011-05-01

    This study attempts to assess the uncertainty in the hydrological impacts of climate change using a multi-model approach combining multiple emission scenarios, GCMs and conceptual rainfall-runoff models to quantify uncertainty in future impacts at the catchment scale. The uncertainties associated with hydrological models have traditionally been given less attention in impact assessments until relatively recently. In order to examine the role of hydrological model uncertainty (parameter and structural uncertainty) in climate change impact studies a multi-model approach based on the Generalised Likelihood Uncertainty Estimation (GLUE) and Bayesian Model Averaging (BMA) methods is presented. Six sets of regionalised climate scenarios derived from three GCMs, two emission scenarios, and four conceptual hydrological models were used within the GLUE framework to define the uncertainty envelop for future estimates of stream flow, while the GLUE output is also post processed using BMA, where the probability density function from each model at any given time is modelled by a gamma distribution with heteroscedastic variance. The investigation on four Irish catchments shows that the role of hydrological model uncertainty is remarkably high and should therefore be routinely considered in impact studies. Although, the GLUE and BMA approaches used here differ fundamentally in their underlying philosophy and representation of error, both methods show comparable performance in terms of ensemble spread and predictive coverage. Moreover, the median prediction for future stream flow shows progressive increases of winter discharge and progressive decreases in summer discharge over the coming century.

  10. Hydrological modeling in alpine catchments: sensing the critical parameters towards an efficient model calibration.

    PubMed

    Achleitner, S; Rinderer, M; Kirnbauer, R

    2009-01-01

    For the Tyrolean part of the river Inn, a hybrid model for flood forecast has been set up and is currently in its test phase. The system is a hybrid system which comprises of a hydraulic 1D model for the river Inn, and the hydrological models HQsim (Rainfall-runoff-discharge model) and the snow and ice melt model SES for modeling the rainfall runoff form non-glaciated and glaciated tributary catchment respectively. Within this paper the focus is put on the hydrological modeling of the totally 49 connected non-glaciated catchments realized with the software HQsim. In the course of model calibration, the identification of the most sensitive parameters is important aiming at an efficient calibration procedure. The indicators used for explaining the parameter sensitivities were chosen specifically for the purpose of flood forecasting. Finally five model parameters could be identified as being sensitive for model calibration when aiming for a well calibrated model for flood conditions. In addition two parameters were identified which are sensitive in situations where the snow line plays an important role.

  11. Hydrological modeling in alpine catchments: sensing the critical parameters towards an efficient model calibration.

    PubMed

    Achleitner, S; Rinderer, M; Kirnbauer, R

    2009-01-01

    For the Tyrolean part of the river Inn, a hybrid model for flood forecast has been set up and is currently in its test phase. The system is a hybrid system which comprises of a hydraulic 1D model for the river Inn, and the hydrological models HQsim (Rainfall-runoff-discharge model) and the snow and ice melt model SES for modeling the rainfall runoff form non-glaciated and glaciated tributary catchment respectively. Within this paper the focus is put on the hydrological modeling of the totally 49 connected non-glaciated catchments realized with the software HQsim. In the course of model calibration, the identification of the most sensitive parameters is important aiming at an efficient calibration procedure. The indicators used for explaining the parameter sensitivities were chosen specifically for the purpose of flood forecasting. Finally five model parameters could be identified as being sensitive for model calibration when aiming for a well calibrated model for flood conditions. In addition two parameters were identified which are sensitive in situations where the snow line plays an important role. PMID:19759453

  12. GIS as an Integration Tool for Hydrologic Modeling: Spatial Data Management, Analysis and Visualization

    NASA Astrophysics Data System (ADS)

    Setegn, S. G.; Lawrence, A.; Mahmoudi, M.

    2015-12-01

    The Applied Research Center at Florida International University (ARC-FIU) is supporting the soil and groundwater remediation efforts of the U.S. Department of Energy (DOE) Savannah River Site (SRS) by developing a surface water model to simulate the hydrology and the fate and transport of contaminants and sediment in the Tims Branch watershed. The first phase of model development was initiated in 2014 using the MIKE SHE/MIKE 11 hydrological modeling package which has a geographic information systems (GIS) user interface built into its system that can directly use spatial GIS databases (geodatabases) for model inputs. This study developed an ArcGIS geodatabase to support the hydrological modeling work for SRS. The coupling of a geodatabase with MIKE SHE/MIKE 11 numerical models can serve as an efficient tool that significantly reduces the time needed for data preparation. The geodatabase provides an advanced spatial data structure needed to address the management, processing, and analysis of large GIS and timeseries datasets derived from multiple sources that are used for numerical model calibration, uncertainty analysis, and simulation of flow and contaminant fate and transport during extreme climatic events. The geodatabase developed is based on the ArcHydro and ArcGIS Base Map data models with modifications made for project specific input parameters. The significance of this approach was to ensure its replicability for potential application in other watersheds. This paper describes the process of development of the SRS geodatabase and the application of GIS tools to pre-process and analyze hydrological model data; automate repetitive geoprocessing tasks; and produce maps for visualization of the surface water hydrology of the Tims Branch watershed. Key Words: GIS, hydrological modeling, geodatabase, hydrology, MIKE SHE/MIKE 11

  13. 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

  14. Coupled forest growth-hydrology modelling as an instrument for the assessment of effects of forest management on hydrology in forested catchments

    NASA Astrophysics Data System (ADS)

    Sutmöller, J.; Hentschel, S.; Hansen, J.; Meesenburg, H.

    2011-03-01

    The type and intensity of forest management directly influences regional catchment hydrology. Future forest management must optimise the effects of its practices to achieve sustainable management. With scenario analysis of forestry practices, the effects of different forest utilisation strategies on the hydrology of forested catchments can be temporally and spatially quantified. The approach adopted in this study necessitated the development of an interactive system for the spatially distributed modelling of hydrology in relation to forest stand development. Consequently, a forest growth model was used to simulate stand development assuming various forest management activities. Selected simulated forest growth parameters were entered into the hydrological model to simulate water fluxes under different conditions of forest structure. The approach enables the spatially differentiated quantification of changes in the water regime (e.g. increased evapotranspiration). The results of hydrological simulations in the study area, the Oker catchment (northern Harz Mountains), show that forests contribute to the protection of water systems because they have a balancing effect on the hydrological regime. As scenario simulations also suggest, however, forestry practices can also lead to substantial changes in water budgets of forested catchments. The preservation of the hydrological services of forests requires a sustainable and long-term forest conversion on the basis of current management directives for near natural silviculture. Management strategies on basis of moderate harvesting regimes are preferred because of their limited impact on the water budget.

  15. New insight into unstable hillslopes hydrology from hydrogeochemical modelling.

    NASA Astrophysics Data System (ADS)

    Bertrand, C.; Marc, V.; Malet, J.-P.

    2010-05-01

    In the black marl outcrops of the French South Alps, sub surface flow conditions are considered as the main triggering factor for initiation and reactivation of landslides. The problem is traditionally addressed in term of hydrological processes (how does percolation to the water table occur?) but in some cases the origin of water is also in question. Direct rainfall is generally assumed as the only water source for groundwater recharge in shallow hillslope aquifers. The bedrock is also supposed impervious and continuous. Yet the geological environment of the study area is very complex owing to the geological history of this alpine sector. The autochthonous callovo-oxfordian black marl bedrock is highly tectonized (Maquaire et al., 2003) and may be affected by large, possibly draining discontinuities. A deep water inflow at the slip surface may at least locally result in increase the pore pressure and decrease the effective shearing resistance of the landslide material. In the active slow-moving landslide of Super-Sauze (Malet and Maquaire, 2003), this question has been addressed using hydrochemical investigations. The groundwater was sampled during five field campaigns uniformly spread out over the year from a network of boreholes. Water chemistry data were completed by geochemical and mineralogical analyses of the marl material. The major hydro-geochemical processes over area proved (1) mixing processes, (2) pyrite alteration, (3) dissolution/precipitation of carbonates and (4) cations exchange (de Montety et al., 2007). A geochemical modelling was carried out using the model Phreeqc (Parkhurst and Appelo, version 2.15, 2008) to check how suitable was observed water chemistry with the reservoir characteristics. The modelling exercise was based on a kinetics approach of soil-water interactions. The model simulates the rock alteration by the dissolution of the primary minerals and the precipitation of new phases. Initial parameters were obtained from geochemical

  16. New insight into unstable hillslopes hydrology from hydrogeochemical modelling.

    NASA Astrophysics Data System (ADS)

    Bertrand, C.; Marc, V.; Malet, J.-P.

    2010-05-01

    In the black marl outcrops of the French South Alps, sub surface flow conditions are considered as the main triggering factor for initiation and reactivation of landslides. The problem is traditionally addressed in term of hydrological processes (how does percolation to the water table occur?) but in some cases the origin of water is also in question. Direct rainfall is generally assumed as the only water source for groundwater recharge in shallow hillslope aquifers. The bedrock is also supposed impervious and continuous. Yet the geological environment of the study area is very complex owing to the geological history of this alpine sector. The autochthonous callovo-oxfordian black marl bedrock is highly tectonized (Maquaire et al., 2003) and may be affected by large, possibly draining discontinuities. A deep water inflow at the slip surface may at least locally result in increase the pore pressure and decrease the effective shearing resistance of the landslide material. In the active slow-moving landslide of Super-Sauze (Malet and Maquaire, 2003), this question has been addressed using hydrochemical investigations. The groundwater was sampled during five field campaigns uniformly spread out over the year from a network of boreholes. Water chemistry data were completed by geochemical and mineralogical analyses of the marl material. The major hydro-geochemical processes over area proved (1) mixing processes, (2) pyrite alteration, (3) dissolution/precipitation of carbonates and (4) cations exchange (de Montety et al., 2007). A geochemical modelling was carried out using the model Phreeqc (Parkhurst and Appelo, version 2.15, 2008) to check how suitable was observed water chemistry with the reservoir characteristics. The modelling exercise was based on a kinetics approach of soil-water interactions. The model simulates the rock alteration by the dissolution of the primary minerals and the precipitation of new phases. Initial parameters were obtained from geochemical

  17. Seasonal forecasting of global hydrologic extremes using the North American Multi-model Ensemble system

    NASA Astrophysics Data System (ADS)

    Wood, Eric F.; Yuan, Xing; Roundy, Joshua K.; Sheffield, Justin

    2015-04-01

    Seasonal hydrologic extremes in the form of droughts and wet spells have devastating impacts on human and natural systems. Improving our understanding and predictive capability of hydrologic extremes, and facilitating adaptations through establishing climate service systems at regional to global scales, are among the grand challenges proposed by the World Climate Research Programme (WCRP), and are the core themes of the Regional Hydroclimate Projects (RHP) under the Global Energy and Water Exchanges Project (GEWEX). An experimental global seasonal hydrologic forecasting system has been developed, which is based on coupled climate forecast models participating in the North American Multi-Model Ensemble (NMME) project and an advanced land surface hydrologic model. The system is evaluated over major GEWEX/RHP river basins by comparing with Ensemble Streamflow Prediction (ESP). The multi-model seasonal forecast system provides higher detectability for soil moisture droughts, more reliable low and high flow ensemble forecasts, and better "real-time" prediction for the 2012 North American extreme drought. The association of the onset of extreme hydrologic events with oceanic and land precursors is also investigated based on the joint distribution of forecasts and observations. Climate models have a higher probability of missing the onset of hydrologic extremes when there is no oceanic precursor. But oceanic precursor alone is insufficient to guarantee a correct forecast, a land precursor is also critical in avoiding a false alarm for forecasting extremes. This study is targeted at providing the scientific underpinning for the predictability of hydrologic extremes over GEWEX/RHP basins, and serves as a prototype for seasonal hydrologic forecasts within the Global Framework for Climate Services (GFCS).

  18. Hydrologic Sensitivity to Climate Change of Precipitation Patterns via Integrated Modeling

    NASA Astrophysics Data System (ADS)

    Daniels, B. K.

    2011-12-01

    Understanding the impacts of climate change on water resources is critical to ecosystems and to human well being. Most previous work has involved coupling hydrologic models to global and regional climate models. While there is impressive agreement among climate models on temperature increase, unfortunately precipitation estimates present "wildly diverging pictures" [Schiermeier, Nature 2010]. In the IPCC AR4 WG1 SPM on page 16 one sees for most of the mid-latitudes that more than 1/3 of the models disagree with the majority on even the sign of any precipitation change and significant agreement of 90% is typically only found in the polar reaches [Oreskes, Philosophy of Science 2010]. Since precipitation is the primary driver of hydrology, therefore coupling of these climate models to hydrology can only yield projections that are highly uncertain. This work instead offers basic insight into the connections between all sorts of climate possibilities and hydrology. The observational climate inputs to GSFLOW basin models have been tweaked to compute the sensitivity of hydrological components to change in many climate variables. Impacts were evaluated from individual changes from a precipitation pattern such as total amounts, event intensities, event rates, durations, frequencies, and season lengths. By considering each precipitation pattern separately, we separate the confounding factors when all are changing at the same time and can then observe the impact of each factor by itself. Sensitivities have been computed for some 20 hydrologic flow components, such as runoff, infiltration, soil ET, interflow, recharge, baseflow, and streamflows. This hydrological