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1

Development and test of the distributed HBV96 hydrological model  

Microsoft Academic Search

A comprehensive re-evaluation of the HBV hydrological model has been carried out. The objectives were to improve its potential for making use of spatially distributed data, to make it more physically sound and to improve the model performance. The new version, HBV-96, uses subbasin division with a typical resolution of 40 km z, although any resolution can be used. In

Göran Lindström; Barbro Johansson; Magnus Persson; Marie Gardelin; Sten Bergström

1997-01-01

2

The hydrological response of the Ourthe catchment to climate change as modelled by the HBV model  

Microsoft Academic Search

The Meuse is an important river in Western Europe, which is almost exclusively rain-fed. Projected changes in precipitation characteristics due to climate change, therefore, are expected to have a considerable effect on the hydrological regime of the river Meuse. We focus on an important tributary of the Meuse, the Ourthe, measuring about 1600 km2. The well-known hydrological model HBV is

T. L. A. Driessen; R. T. W. L. Hurkmans; W. Terink; P. Hazenberg; P. J. J. F. Torfs; R. Uijlenhoet

2010-01-01

3

The hydrological response of the Ourthe catchment to climate change as modelled by the HBV model  

Microsoft Academic Search

The Meuse is an important river in western Europe, and almost exclusively rain-fed. Projected changes in precipitation characteristics due to climate change, therefore, are expected to have a considerable effect on the hydrological regime of the river Meuse. We focus on an important tributary of the Meuse, the Ourthe, measuring about 1600 km2. The well-known hydrological model HBV is forced

T. L. A. Driessen; R. T. W. L. Hurkmans; W. Terink; P. Hazenberg; P. J. J. F. Torfs; R. Uijlenhoet

2009-01-01

4

Hydrologic Simulation With a Distributed Hydrologic Model  

Microsoft Academic Search

Hydrologic processes are sensitive to the spatial distribution of hydrologic parameters in watersheds. A distributed hydrologic model which can simulate various components of a watershed hydrologic cycle such as surface water, channel water, soil water and groundwater as well their interactions is used to simulate various hydrologic processes in the Meilin watershed in this paper. The parameters with physical meanings

Xing Chen; Zhongbo Yu; Guangbai Cui

2008-01-01

5

Solicited abstract: Global hydrological modeling and models  

NASA Astrophysics Data System (ADS)

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, (3) state-of-the-art of existing global hydrological models, and (4) challenges. Acknowledgment: Thanks to Lebing Gong, Elin Widén-Nilsson, and Sven Halldin of Uppsala University for the team work in global hydrological models.

Xu, Chong-Yu

2010-05-01

6

The use of HBV model for flash flood forecasting  

Microsoft Academic Search

The standard conceptual HBV model was originally developed with daily data and is normally operated on daily time step. But many floods in Slovenia are usually flash floods as result of intense frontal precipitation combined with orographic enhancement. Peak discharges are maintained only for hours or even minutes. To use the HBV model for flash flood forecasting, the version of

M. Kobold; M. Brilly

2006-01-01

7

netherland hydrological modeling instrument  

NASA Astrophysics Data System (ADS)

Netherlands Hydrological Modeling Instrument A decision support system for water basin management. J.C. Hoogewoud , W.J. de Lange ,A. Veldhuizen , G. Prinsen , The Netherlands Hydrological modeling Instrument (NHI) is the center point of a framework of models, to coherently model the hydrological system and the multitude of functions it supports. Dutch hydrological institutes Deltares, Alterra, Netherlands Environmental Assessment Agency, RWS Waterdienst, STOWA and Vewin are cooperating in enhancing the NHI for adequate decision support. The instrument is used by three different ministries involved in national water policy matters, for instance the WFD, drought management, manure policy and climate change issues. The basis of the modeling instrument is a state-of-the-art on-line coupling of the groundwater system (MODFLOW), the unsaturated zone (metaSWAP) and the surface water system (MOZART-DM). It brings together hydro(geo)logical processes from the column to the basin scale, ranging from 250x250m plots to the river Rhine and includes salt water flow. The NHI is validated with an eight year run (1998-2006) with dry and wet periods. For this run different parts of the hydrology have been compared with measurements. For instance, water demands in dry periods (e.g. for irrigation), discharges at outlets, groundwater levels and evaporation. A validation alone is not enough to get support from stakeholders. Involvement from stakeholders in the modeling process is needed. There fore to gain sufficient support and trust in the instrument on different (policy) levels a couple of actions have been taken: 1. a transparent evaluation of modeling-results has been set up 2. an extensive program is running to cooperate with regional waterboards and suppliers of drinking water in improving the NHI 3. sharing (hydrological) data via newly setup Modeling Database for local and national models 4. Enhancing the NHI with "local" information. The NHI is and has been used for many decision supports and evaluations. The main focus of the instrument is operational drought management and evaluating adaptive measures for different climate scenario's. It has also been used though as a basis to evaluate water quality of WFD-water bodies and measures, nutrient-leaching and describing WFD groundwater bodies. There is a toolkit to translate the hydrological NHI results to values for different water users. For instance with the NHI results agricultural yields can be calculated, effects on ground water dependant ecosystems, subsidence, shipping, drinking water supply. This makes NHI a valuable decision support system in Dutch water management.

Hoogewoud, J. C.; de Lange, W. J.; Veldhuizen, A.; Prinsen, G.

2012-04-01

8

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

9

Hydrological models are mediating models  

NASA Astrophysics Data System (ADS)

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 more importance to identifying and communicating on the many factors involved in model development might increase transparency of model building.

Babel, L. V.; Karssenberg, D.

2013-08-01

10

Thermal-hydrological models  

SciTech Connect

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

Buscheck, T., LLNL

1998-04-29

11

PATHS groundwater hydrologic model  

SciTech Connect

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.

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

1980-04-01

12

Modelling Hydrological Effects on Gravity  

NASA Astrophysics Data System (ADS)

Hydrological effects on gravity have sizeable impact on the accurate terrestrial gravity observations with superconducting (SG) and absolute gravimeters (AG). These effects, that contain strong seasonal signals, represent important problem in AG and SG observation feasibility in current geodynamic studies (Earth recent dynamics, post-glacial rebound, long-period tides, etc.). At present, hydrological effects are reliably estimated only at few SG stations, where detailed hydro-geological studies of station vicinity and many hydro-meteorological observations are being realized. However, the knowledge of hydrological effects with an accuracy of about 1 microgal are also very important at many sites, where accurate repeated absolute gravity measurements are performed. Unfortunately, very expensive detailed hydrological studies of such stations are unrealistic. Presented are the results of hydrological effects on gravity computed on basis of widespread WGHM and LaDWorld hydrological models. For Europe a global contribution of hydrological effects (distance>2 km) is computed. The local contribution of hydrological effects (distance<2 km) is modelled for the station Pecný based on the nearest WGHM data and variable information about station vicinity. The modelled hydrological effects are compared with combined SG and AG gravity series at the station.

Pálinkás, V.

2009-04-01

13

Thermal-hydrological models.  

National Technical Information Service (NTIS)

This chapter describes the physical processes and natural and engineered system conditions that affect thermal-hydrological (T-H) behavior in the unsaturated zone (UZ) at Yucca Mountain and how these effects are represented in mathematical and numerical m...

T. Buscheck

1998-01-01

14

The Distributed Hydrology Soil Vegetation Model  

Microsoft Academic Search

The use of distributed physically based models in environmental analysis is becoming more common as greater demands are placed on hydrologic models, particularly for problems involving prediction of future hydrologic conditions resulting from changes in land use or climate. The Distributed Hydrology Soil Vegetation Model (DHSVM) is a physically based model that provides a dynamic representation of the spatial distribution

Mark S. Wigmosta; Bart Nijssen; Pascal Storck; VP Singh; DK Frevert

2002-01-01

15

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

NASA Astrophysics Data System (ADS)

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

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

2012-05-01

16

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

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

17

Towards an Objective Model of Catchment Hydrology  

Microsoft Academic Search

The internal structure of catchment hydrologic models remains one of the most subjective elements of coupled hydrologic and biogeochemical models, despite the recognized sensitivity of predictions to the chosen model structure. Hillslope hydrologic studies indicate the high degree of complexity in transport processes at this spatial scale (e.g., variably saturated media, macropore-dominated transport). How can the complexities observed at the

R. P. Hooper; J. J. McDonnell; K. N. Hjerdt; B. L. McGlynn

2001-01-01

18

Rangeland Hydrology and Erosion Model  

NASA Astrophysics Data System (ADS)

Soil loss rates on rangelands are considered one of the few quantitative indicators for assessing rangeland health and conservation practice effectiveness. An erosion model to predict soil loss specific for rangeland applications has been needed for many years. Most erosion models were developed from croplands where the hydrologic and erosion processes are different, largely due to much higher levels of heterogeneity in soil and plant properties at the plot scale and the consolidated nature of the soils. The Rangeland Hydrology and Erosion Model (RHEM) was designed to fill that need. RHEM is an event-based model that estimates runoff, erosion, and sediment delivery rates and volumes at the spatial scale of the hillslope and the temporal scale of a single rainfall event. It represents erosion processes under normal and fire-impacted rangeland conditions, it adopts a new splash erosion and thin sheet-flow transport equation developed from rangeland data, and it links the model hydrologic and erosion parameters with rangeland plant communities by providing a new system of parameter estimation equations based on 204 plots at 49 rangeland sites distributed across 15 western U.S. states. Recent work on the model is focused on representing intra-storm dynamics, using stream-power as the driver for detachment by flow, and deriving parameters for after-fire conditions.

Nearing, Mark; Pierson, Fred; Hernandez, Mariano; Al-Hamdan, Osama; Weltz, Mark; Spaeth, Ken; Wei, Haiyan; Stone, Jeff

2013-04-01

19

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

SciTech Connect

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.

Hinzman, L.D.; Kane, D.L. (Univ. of Alaska, Fairbanks (United States))

1991-06-01

20

On the predictability of hydrological droughts with a conceptual model  

NASA Astrophysics Data System (ADS)

Since the extreme summer of 2003 the importance of early drought warning is increasingly recognized also in apparently water-rich countries like Switzerland. The year 2011 provided additional examples of drought conditions in Switzerland, which are expected to become more frequent in the future. So far, little has been done regarding drought forecasting in Europe. A fundamental question related to drought forecasting is: How long before a hydrological drought actually occurs, can it be predicted? To address this question, we assessed the relative importance of current hydrological state and weather during the prediction period. A conceptual catchment model, the HBV model, was calibrated to 21 Swiss catchments and for each of them two modeling experiments were performed: 1) Streamflow was simulated starting with the same initial hydrological state but with different observed series (i.e., from different years) of precipitation and temperature to derive 'predictions'. 2) Streamflow was simulated using various initial hydrological states, but the same longterm means of precipitation and temperature as forcing. Both experiments were repeated four times, shifting the start of the simulations to different seasons. The relative importance of initial hydrological state and weather during the prediction period was evaluated by estimating the persistence of the initial hydrological states in the prediction for both experiments. To further distinguish between effects of weather and catchment properties, the resulting persistences were tested on their sensitivity to changes in total precipitation amounts and air temperature. For the investigated catchments the persistence in streamflow appeared to be more depending on catchment characteristics and less on the start of the prediction period. Drier initial conditions of soil moisture and deeper groundwater storage resulted for most catchments in longer persistence estimates, while the initial conditions of snow and upper groundwater storage showed no clear effect on the persistence. From the preliminary results of the sensitivity analysis, the persistence estimates seem not sensitive to changes in precipitation.

Staudinger, Maria; Seibert, Jan

2013-04-01

21

Importance of temporal and spatial resolution on modelling hydrological extremes in a small catchment  

NASA Astrophysics Data System (ADS)

Under the conditions of changing climate the more frequent extremes in hydrological regime are expected. For the small watershed management it is therefore of big interest what the possible range of these changes could be, since it is essential for design of appropriate mitigation measures. An exemplary case study of possible impacts of the climate change was carried out. The conceptual model HBV was applied in a small hilly pre-alpine Rietholzbach catchment with the aim to assess the frequency and magnitude of hydrological extremes under different climatic conditions. The effect of the time and spatial distribution on the model output characteristics was also investigated. For impact evaluation a conceptual lumped model HBV was chosen because of its robustness, easy applicability for long-term simulations and perceptually straight-forward parameters. Two different modelling approaches were used, in the first one the catchment of interest was treated as a lumped system and in the other where it was divided into several subcatchments. As a first step HBV was applied to the historical data set to evaluate his performance and suitability for hydrological predictions. One half of the data time-series was used for HBV parameter calibration, the other one for model validation, wherefore several objective functions were used for goodness of fit evaluation. In order to obtain the range of changes in hydrological characteristics which can be expected due to the changing climate, two extreme scenarios were then applied to the catchment model. A standard daily step was used to obtain data for water balance and long-term droughts analysis and a study of applicability of the model with the hourly computational step was performed, so that occurrance of maximum discharges could be evaluated. The poster presents the model outcomes with focus on flood and long-drought characteristics. The uncertainty of the impacts is illustrated by the range of characteristics obtained from different climatic scenarios, spatial resolution of the model and considers the model reliability as well.

Strouhal, L.; Seibert, J.; David, V.

2012-04-01

22

Ensemble stream flow predictions, a way towards better hydrological forecasting  

Microsoft Academic Search

The hydrological forecasting division at SMHI has been using hydrological EPS and hydrological probabilities forecasts operationally since some years ago. The inputs to the hydrological model HBV are the EPS forecasts from ECMWF. From the ensemble, non-exceedance probabilities are estimated and final correction of the ensemble spread, based on evaluation is done. Ensemble stream flow predictions are done for about

C. Edlund

2009-01-01

23

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

PubMed Central

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

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

2013-01-01

24

SIMPLE SNOWDRIFT MODEL FOR DISTRIBUTED HYDROLOGICAL MODELING  

Technology Transfer Automated Retrieval System (TEKTRAN)

Snow transport and deposition can be an important factor in the distribution of spring soil moisture and runoff. Although current hydrological models often attempt to account for heterogeneities in precipitation distribution they do not account for snowdrift effects. A simple snowdrift model was d...

25

Integrating groundwater dynamics in regional hydrological modelling  

Microsoft Academic Search

The paper presents an integrated catchment model and a method with which it is possible to analyse local water table dynamics inside subbasins along with river flow on the regional scale. A simple but comprehensive mechanistic groundwater module coupled with the eco-hydrological model SWIM (Soil and Water Integrated Model), which integrates hydrological processes, vegetation, erosion and nutrient dynamics at the

Fred Hattermann; Valentina Krysanova; Frank Wechsung; Martin Wattenbach

2004-01-01

26

Integration of Local Hydrology into Regional Hydrologic Simulation Model  

NASA Astrophysics Data System (ADS)

South Florida hydrology is dominated by the Central and South Florida (C&SF) Project that is managed to provide flood protection, water supply and environmental protection. A complex network of levees canals and structures provide these services to the individual drainage basins. The landscape varies widely across the C&SF system, with corresponding differences in the way water is managed within each basin. Agricultural areas are managed for optimal crop production. Urban areas maximize flood protection while maintaining minimum water levels to protect adjacent wetlands and local water supplies. "Natural" areas flood and dry out in response to the temporal distribution of rainfall. The evaluation of planning, regulation and operational issues require access to a simulation model that captures the effects of both regional and local hydrology. The Regional Simulation Model (RSM) uses a "pseudo-cell" approach to integrate local hydrology within the context of a regional hydrologic system. A 2-dimensional triangulated mesh is used to represent the regional surface and ground water systems and a 1-dimensional canal network is superimposed onto this mesh. The movement of water is simulated using a finite volume formulation with a diffusive wave approximation. Each cell in the triangulated mesh has a "pseudo-cell" counterpart, which represents the same area as the cell, but it is conceptualized such that it simulates the localized hydrologic conditions Protocols have been established to provide an interface between a cell and its pseudo-cell counterpart. . A number of pseudo-cell types have already been developed and tested in the simulation of Water Conservation Area 1 and several have been proposed to deal with specific local issues in the Southwest Florida Feasibility Study. This presentation will provide an overview of the overall RSM design, describe the relationship between cells and pseudo-cells, and illustrate how pseudo-cells are be used to simulate agriculture, urban and wetland hydrology.

Van Zee, R. J.; Lal, W. A.

2002-05-01

27

The Central Valley Hydrologic Model  

NASA Astrophysics Data System (ADS)

Historically, California’s Central Valley has been one of the most productive agricultural regions in the world. The Central Valley also is rapidly becoming an important area for California’s expanding urban population. In response to this competition for water, a number of water-related issues have gained prominence: conjunctive use, artificial recharge, hydrologic implications of land-use change, subsidence, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS made a detailed assessment of the Central Valley aquifer system that includes the present status of water resources and how these resources have changed over time. The principal product of this assessment is a tool, referred to as the Central Valley Hydrologic Model (CVHM), that simulates surface-water flows, groundwater flows, and land subsidence in response to stresses from human uses and from climate variability throughout the entire Central Valley. The CVHM utilizes MODFLOW combined with a new tool called “Farm Process” to simulate groundwater and surface-water flow, irrigated agriculture, land subsidence, and other key processes in the Central Valley on a monthly basis. This model was discretized horizontally into 20,000 1-mi2 cells and vertically into 10 layers ranging in thickness from 50 feet at the land surface to 750 feet at depth. A texture model constructed by using data from more than 8,500 drillers’ logs was used to estimate hydraulic properties. Unmetered pumpage and surface-water deliveries for 21 water-balance regions were simulated with the Farm Process. Model results indicate that human activities, predominately surface-water deliveries and groundwater pumping for irrigated agriculture, have dramatically influenced the hydrology of the Central Valley. These human activities have increased flow though the aquifer system by about a factor of six compared to pre-development conditions. The simulated hydrology reflects spatial and temporal variability in climate, land-use changes, and available surface-water deliveries. For example, the droughts of 1976-77 and 1987-92 led to reduced streamflow and surface-water deliveries and increased evapotranspiration and groundwater pumpage throughout most of the valley, resulting in a decrease in groundwater storage. Since the mid-1990s, annual surface-water deliveries generally have exceeded groundwater pumpage, resulting in an increase or no change in groundwater storage throughout most of the valley. However, groundwater is still being removed from storage during most years in the southern part of the Central Valley. The CVHM is designed to be coupled with Global Climate Models to forecast the potential supply of surface-water deliveries, demand for groundwater pumpage, potential subsidence, and changes in groundwater storage in response to different climate-change scenarios. The detailed database on texture properties coupled with CVHM's ability to simulate the combined effects of recharge and discharge make CVHM particularly useful for assessing water-management plans, such as conjunctive water use, conservation of agriculture land, and land-use change. In the future, the CVHM could be used in conjunction with optimization models to help evaluate water-management alternatives to effectively utilize the available water resources.

Faunt, C.; Belitz, K.; Hanson, R. T.

2009-12-01

28

Calibration of hydrological models on hydrologically unusual events  

NASA Astrophysics Data System (ADS)

The length of the observation period used for model calibration has a great influence on the identification of the model parameters. In this contribution it is shown that a relatively small number of so called unusual time periods are sufficient to specify the model parameters with the same certainty as using the whole observation period. The unusual events are identified from discharge or precipitation observations series using the statistical concept of data depth. The idea is to distinguish between model states which are covered by previously observed states (interpolation case), and those for which no similar events occurred (extrapolation case). Depth functions are used to identify unusual events from four days lagged discharge or API (antecedent precipitation index) series. Data with low depth are near the boundary of the multivariate set and are thus considered as unusual. The depth is calculated using the observations, their natural logarithms, their rank and their first differences. Model calibration using the selected critical periods is only slightly worse than using all data. The transferability of the parameters for different time periods is equally good as using all the data and significantly better than random selection. Two different models (HBV and HYMOD) are used to demonstrate the methodology for the Neckar catchment in South-West Germany. The methodology developed in this study can be potentially useful for developing monitoring strategies.

Singh, Shailesh Kumar; Bárdossy, András

2012-03-01

29

Snow hydrology in a general circulation model  

SciTech Connect

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. A 3-year GCM simulation with this 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. 52 refs., 13 figs., 5 tabs.

Marshall, S. (Colorado State Univ., Fort Collins, CO (United States)); Roads, J.O. (Univ. of California, San Diego, CA (United States)); Glatzmaier, G. (Los Alamos National Lab., NM (United States))

1994-08-01

30

Hydrological model selection: A Bayesian alternative  

NASA Astrophysics Data System (ADS)

The evaluation and comparison of hydrological models has long been a challenge to the practicing hydrological community. No single model can be identified as ideal over the range of possible hydrological situations. With the variety of models available, hydrologic modelers are faced with the problem of determining which model is best applied to a catchment for a particular modeling exercise. The model selection problem is well documented in hydrologic studies, but a broadly applicable as well as theoretically and practically sound method for comparing model performance does not exist in the literature. Bayesian statistical inference, with computations carried out via Markov chain Monte Carlo (MCMC) methods, offers an attractive alternative to conventional model selection methods allowing for the combination of any preexisting knowledge about individual models and their respective parameters with the available catchment data to assess both parameter and model uncertainty. The aim of this study is to present a method by which hydrological models may be compared in a Bayesian framework. The study builds on previous work (Marshall et al., 2004) in which a Bayesian approach implemented using MCMC algorithms was presented as a simple and efficient basis for assessing parameter uncertainty in hydrological models. In this study, a model selection framework is developed in which an adaptive Metropolis algorithm is used to calculate the model's posterior odds. The model used to illustrate our approach is a version of the Australian Water Balance Model (Boughton, 1993) reformulated such that it can have a flexible number of soil moisture storages. To assess the model selection method in a controlled setting, artificial runoff data were created corresponding to a known model configuration. These data were used to evaluate the accuracy of the model selection method and its sensitivity to the size of the sample being used. An application of the Bayesian model identification methodology to 11 years of daily streamflow data from the Murrumbidgee River at Mittagang Crossing in southeastern Australia concludes our study.

Marshall, Lucy; Nott, David; Sharma, Ashish

2005-10-01

31

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

NASA Astrophysics Data System (ADS)

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.

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

2012-03-01

32

ARMA Model identification of hydrologic time series  

Microsoft Academic Search

In recent years, ARMA models have become popular for modeling geophysical time series in general and hydrologic time series in particular. The identification of the appropriate order of the model is an important stage in ARMA modeling. Such model identification is generally based on the autocorrelation and partial autocorrelation functions, although recently improvements have been obtained using the inverse autocorrelation

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

1982-01-01

33

Hydrologic Models for Inverse Climate Change Impact Modeling  

Microsoft Academic Search

It is expected that the global climate change will have significant impacts on the regime of hydrologic extremes. As a consequence, the design and management of water resource systems will have to adapt to the changing hydrologic extremes. An inverse approach to the modeling of hydrologic risk and vulnerability to changing climatic conditions was developed in this project to improve

Juraj M. Cunderlik; Slobodan P. Simonovic

34

The Central Valley Hydrologic Model  

Microsoft Academic Search

Historically, California's Central Valley has been one of the most productive agricultural regions in the world. The Central Valley also is rapidly becoming an important area for California's expanding urban population. In response to this competition for water, a number of water-related issues have gained prominence: conjunctive use, artificial recharge, hydrologic implications of land-use change, subsidence, and effects of climate

C. Faunt; K. Belitz; R. T. Hanson

2009-01-01

35

Hydrological cycle in the Earth Modelling System  

NASA Astrophysics Data System (ADS)

Earth Modeling System (EMS) is the integrated geophysical system consisting of numerical models for the atmosphere, ocean, land surface and hydrological cycle over land. With an improvement of the computer resources, integration of the first three components became common, but a numerical simulation of the hydrological processes is still not well developed. The idea is to make dynamical hydrological model that will simulate water flow in the environment starting with precipitation, flowing into the rivers and ending in the oceans or lakes. The model should be made to work over any region with no calibration, as do other components of the EMS. One of the dynamical hydrological models is HYPROM (HYdrology PROgnostic Model). In this paper we will present its coupling with the last generation atmospheric model NCEP/NMMB (Non-hydrostatic Multiscale Model on the B grid), the main driver for the ESM that is being developed in the SEEVCCC/RHMSS (South East European Climate Change Center, Republic Hydrometeorological Service of Serbia). Dynamics of the water cycle from precipitation, its infiltration in the ground, runoff and river discharge are very well numerically resolved, while there is still a lot of uncertainties that are related to base flow and underground water. We will show progress in this area of research and problems that are yet to be resolved.

Vujadinovic, Mirjam; Vukovic, Ana; Pejanovic, Goran; Ivkovic, Marija; Djurdjevic, Vladimir; Rajkovic, Borivoj; Nickovic, Slobodan; Dacic, Milan

2013-04-01

36

Uncertainty in hydrologic modeling: Toward an integrated data assimilation framework  

Microsoft Academic Search

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

Yuqiong Liu; Hoshin V. Gupta

2007-01-01

37

Quantile hydrologic model selection and uncertainty assessment  

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

38

Teaching hydrological modelling as a subsidiary subject  

NASA Astrophysics Data System (ADS)

The department of hydrology and water resources management is part of the Ecology Center of Kiel University, an interdisciplinary research organization. We teach hydrology for geographers, biologists, agricultural engineers and ecologists. Hydrological modeling is part of the curriculum since 1988. It has moved from the subject for specialists to a basic component of all hydrological courses. During the first year, we focussed on in-depth teaching of theory and practice of one big model, but the students found it hard to follow and beyond practical problems. During the last years we switched to a broader, but more shallow policy. Modeling is now part of nearly all courses, but remains limited to mostly 2-4 days of teaching. We now present only very basic theory and leave it to the students to discover the details during the practical work with pre-installed data sets. The poster shows how the models SWAT, Hydrus, Coupmodel, SIMPEL and PC-Raster are embedded in the hydrological curriculum and what kind of problems we experienced in teaching.

Hörmann, G.; Schmalz, B.; Fohrer, N.

2009-04-01

39

Effect of Trichinella spiralis Infection on the Immune Response to HBV Vaccine in a Mouse Model.  

PubMed

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

Guan, Fei; Hou, Xiao; Nie, Ge; Xiao, Yan; Zhang, Qi; Liu, Wen-Qi; Li, Yong-Long; Lei, Jia-Hui

2013-07-24

40

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 ...

41

Towards an Objective Model of Catchment Hydrology  

NASA Astrophysics Data System (ADS)

The internal structure of catchment hydrologic models remains one of the most subjective elements of coupled hydrologic and biogeochemical models, despite the recognized sensitivity of predictions to the chosen model structure. Hillslope hydrologic studies indicate the high degree of complexity in transport processes at this spatial scale (e.g., variably saturated media, macropore-dominated transport). How can the complexities observed at the hillslope scale be translated into a general catchment model with modest data requirements, yet retain structure that is defined objectively by data? Observations from a hillslope trench study at Panola Mountain Research Watershed (GA, USA) suggest that residence time of water within a landscape unit may be the single most important physical characteristic determining the observed chemistry for a given setting. We contrast the chemistry of the saturated zone in the hillslope with stream chemistry at three catchments that exhibit a range of residence times. Stream chemistry at the catchment with the shortest residence time is most similar to hillslope chemistry, suggesting that a simple model structure, with few reservoirs, may be appropriate at this site. By contrast, at the site with the longest residence time, the greatest difference is observed between stream and hillslope chemistry, suggesting that more reservoirs are needed to model the catchment. The organizing principle in designing the structure of coupled hydrologic and biogeochemical models is to choose a model structure that reproduces the residence times matching those of the rate constants of critical biogeochemical processes.

Hooper, R. P.; McDonnell, J. J.; Hjerdt, K. N.; McGlynn, B. L.

2001-12-01

42

Dynamic Multicriteria Evaluation of Conceptual Hydrological Models  

Microsoft Academic Search

Accurate and precise forecasts of river streamflows are crucial for successful management of water resources and under the threat of hydrological extremes such as floods and droughts. Conceptual rainfall-runoff models are the most popular approach in flood forecasting. However, the calibration and evaluation of such models is often oversimplified by the use of performance statistics that largely ignore the dynamic

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

2007-01-01

43

Multi-criteria evaluation of hydrological models  

NASA Astrophysics Data System (ADS)

Over the last years, there is a tendency in the hydrological community to move from the simple conceptual models towards more complex, physically/process-based hydrological models. This is because conceptual models often fail to simulate the dynamics of the observations. However, there is little agreement on how much complexity needs to be considered within the complex process-based models. One way to proceed to is to improve understanding of what is important and unimportant in the models considered. The aim of this ongoing study is to evaluate structural model adequacy using alternative conceptual and process-based models of hydrological systems, with an emphasis on understanding how model complexity relates to observed hydrological processes. Some of the models require considerable execution time and the computationally frugal sensitivity analysis, model calibration and uncertainty quantification methods are well-suited to providing important insights for models with lengthy execution times. The current experiment evaluates two version of the Framework for Understanding Structural Errors (FUSE), which both enable running model inter-comparison experiments. One supports computationally efficient conceptual models, and the second supports more-process-based models that tend to have longer execution times. The conceptual FUSE combines components of 4 existing conceptual hydrological models. The process-based framework consists of different forms of Richard's equations, numerical solutions, groundwater parameterizations and hydraulic conductivity distribution. The hydrological analysis of the model processes has evolved from focusing only on simulated runoff (final model output), to also including other criteria such as soil moisture and groundwater levels. Parameter importance and associated structural importance are evaluated using different types of sensitivity analyses techniques, making use of both robust global methods (e.g. Sobol') as well as several alternative local sensitivity analysis methods. The latter methods can yield similar results, however they are much more computationally frugal than the global methods and often are better suited to analysis of complex models. Simple models are used to compare the global and local methods, and insights used to interpret results for complex model for which the local methods are much more convenient. The analyses are carried out for a medium-sized catchment (200 km2) in the Belgian Ardennes, for which meteorological, fluxnet data, in situ soil moisture and groundwater time series are available.

Rakovec, Oldrich; Clark, Martyn; Weerts, Albrecht; Hill, Mary; Teuling, Ryan; Uijlenhoet, Remko

2013-04-01

44

HYPROM hydrology surface-runoff prognostic model  

NASA Astrophysics Data System (ADS)

The major objective of this study was to develop a hydrology model (HYPROM) to simulate overland watershed processes based on advanced numerical and parameterization methods. The resulting model, HYPROM, was designed for real-time watershed prediction. The model solves grid point-based shallow water equations with numerical approaches that include an efficient explicit time-differencing scheme for the gravity wave components and a physically based and numerically stable implicit scheme for the friction slope terms. The model dynamics (advection, diffusion, and height gradient force) are explicitly represented, whereas the model physics (e.g., friction slope) are parameterized, i.e., subgrid effects are expressed in terms of the model grid point variables. The fact that the modeling governing equations for momentum and mass are all prognostic makes HYPROM distinct to most other prognostic hydrology systems. The model uses real topography, river routing, and land cover data to represent surface influences. The HYPROM calculations can be executed offline (i.e., independent of a driving atmospheric model) or online as a callable routine of a driving atmospheric model. The model is applicable across a broad range of spatial scales ranging from local to regional and global scales. The model can be set up over different geographic domains and can run efficiently on conventional computer platforms. Finally, the model can be used either for hydrologic forecasts or climate studies if embedded as a component of an atmospheric climate model.

Nickovic, Slobodan; Pejanovic, Goran; Djurdjevic, Vladimir; Roskar, Jozef; Vujadinovic, Mirjam

2010-11-01

45

Inverse distributed hydrological modelling of Alpine catchments  

NASA Astrophysics Data System (ADS)

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 groundwater model partly yielded a slight decrease of overall model performance when compared to a simple conceptual groundwater approach. Increased model complexity therefore did not yield in general increased model performance. A detailed covariance analysis was performed allowing to derive confidence bounds for all estimated parameters. The correlation between the estimated parameters was in most cases negligible, showing that parameters were estimated independently from each other.

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

2006-06-01

46

ARMA Model Identification of Hydrologic Time Series  

NASA Astrophysics Data System (ADS)

In recent years, ARMA models have become popular for modeling geophysical time series in general and hydrologic time series in particular. The identification of the appropriate order of the model is an important stage in ARMA modeling. Such model identification is generally based on the autocorrelation and partial autocorrelation functions, although recently improvements have been obtained using the inverse autocorrelation and the inverse partial autocorrelation functions. This paper demonstrates the use of the generalized partial autocorrelation function (GPAF) and the R and S functions of Gray et al. (1978) for ARMA model identification of hydrologic time series. These functions are defined, and some recursive relations are given for ease of computation. All three functions, when presented in tabular form, have certain characteristic patterns that are useful in ARMA model identification. Several examples are included to demonstrate the usefulness of the proposed identification technique. Actual applications are made using the Saint Lawrence River and Nile River annual streamflow series.

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

1982-08-01

47

Plant growth simulation for landscape-scale hydrological modelling  

Microsoft Academic Search

Landscape-scale hydrological models can be improved by incorporating realistic, process-oriented plant models for simulating crops, perennial grasses and woody species. The objective of this project was to present some approaches for plant modelling applicable to daily time step hydrological transport models, such as SWAT. Accurate simulation of plant growth can improve the accuracy of simulations of hydrological and biogeochemical cycles.

J. R. KINIRY; J. D. MACDONALD; ARMEN R. KEMANIAN; BRETT WATSON; GORDON PUTZ; ELLIE E. PREPAS

2008-01-01

48

Models capture hydrological processes in coastal environments  

NASA Astrophysics Data System (ADS)

It is inherently difficult, if not impossible, to observe and make adequate measurement of certain types of natural processes. For instance, whether it is the formation of landscapes, such as deltas, or fine-scale processes, such as the transport of fluids and solutes, water flowing over surfaces has presented major challenges for scientists interested in studying hydrologic processes occurring at the interface of the surface and flowing water. Although researchers have relied on numerical models to simulate hydrological processes that operate along a sediment-water interface, the method has been criticized for not being verified by in situ observations. However, new research shows that numerical simulations based on fluid dynamical properties do broadly mimic hydrological processes at the sediment and flowing water interface, at least in systems where water flows over, below, or adjacent to porous sedimentary surfaces, such as in coastal marine environments.

Bhattacharya, Atreyee

2012-10-01

49

HYDROLOGICAL MODELING USING REMOTE SENSING AND GIS  

Microsoft Academic Search

Accurate modeling will require estimation of the spatial and temporal distribution of the water resources parameters. During the last decades engineers and planners have shown the increasing interest of applying Geographic Information Systems (GIS) and satellite based Remote Sensing (RS) technologies to extract land surface parameters, which exist as a threshold in early days to approach reasonable results in hydrologic

Chandana Gangodagamage; S. P. Aggarwal

50

Inverse distributed hydrological modelling of alpine catchments  

NASA Astrophysics Data System (ADS)

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 allowing to derive confidence bounds for all estimated parameters. The correlation between the estimated parameters was in most cases negligible, showing that parameters were estimated independently from each other.

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

2005-12-01

51

Hydrological Similarity and Consistently Wrong models  

NASA Astrophysics Data System (ADS)

Hydrological models are only approximations of real world system being investigated or forecast. They are typically driven by input data that may not be representative of the true forcing and is observational error. Performance is assessed against data that suffers from similar defects. Given this it is reasonable to question both the amount of information about my model contained in the data but also how the model and data can be related. The method outlined in this poster attempts to balance the desire the desire to fit the observed data against the risk of over fitting. The method is motivated by the idea that in hydrologically similar situations the model residuals should be in some sense consistent. Assessment of this consistency is clouded by error sources outlined above. By using clustering techniques to relate the model states; which indicate hydrological similarity in terms of the model; observed data and the residuals of the model fit it is shown that useful measures of model performance can be derived. The use of these to explore the information content of differing time periods is outlined and the underlying assumptions critiqued.

Smith, P. J.; Beven, K.

2012-04-01

52

Usefulness of four hydrological models in simulating high-resolution discharge dynamics of a catchment adjacent to a road  

NASA Astrophysics Data System (ADS)

Four hydrological models (LISEM, MIKE SHE, CoupModel and HBV) were compared with respect to their capability to predict peak flow in a small catchment upstream of a road in SE Norway on an hourly basis. All four models were calibrated using hourly observed streamflow. Simulated and observed discharge generated during three types of hydrological situations characteristic of winter/spring conditions causing overland flow were considered: snowmelt, partially frozen soil and heavy rain events. Using parameter sets optimised for winter/spring conditions, flows simulated by HBV coupled with CoupModel were comparable to measured discharge from the catchment in corresponding periods. However, this combination was best when all the parameters were calibrated in HBV. For ungauged basins with no real-time monitoring of discharge and when the spatial distribution is important, MIKE SHE may be more suitable than the other models, but the lack of detailed input data and the uncertainty in physical parameters should be considered. LISEM is potentially capable of calculating runoff from small catchments during winter/spring but requires better description of snowmelt, infiltration into frozen layers and tile drainage. From a practical road maintenance perspective, the usefulness and accuracy of a model depends on its ability to represent site-specific processes, data availability and calibration requirements.

Kalantari, Z.; Jansson, P.-E.; Stolte, J.; Folkeson, L.; French, H. K.; Sassner, M.

2012-04-01

53

A physically-based Distributed Hydrologic Model for Tropical Catchments  

Microsoft Academic Search

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

N. A. Abebe; F. L. Ogden

2010-01-01

54

Delineation of topographic process entities using SRTM for hydrological modelling  

Microsoft Academic Search

The concept of distributed hydrological models is based on the integration of landscape components to delineate distributed process entities. These Hydrological Response Units (HRU) are topologically connected model entities and represent areas of homogeneous topographic and physiographic environment and therewith the hydrological system response. The HRU regionalisation concept is realised by the intersection of landscape parameters such as topography, land

M. Wolf; B. Pfennig; P. Krause

2009-01-01

55

Enhancements for Hydrological Modeling in ESMF  

NASA Astrophysics Data System (ADS)

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 components to be browsed and linked to the data they ingest and produce. The hope is that these enhancements will facilitate integration with other efforts in the hydrology community, and coupling interfaces to the domains such as weather prediction where ESMF is becoming part of the standard infrastructure.

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

2008-12-01

56

Hydrology  

ERIC Educational Resources Information Center

|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)|

Sharp, John M., Jr.

1978-01-01

57

Validation of the hydrological cycle of ECMWF and NCEP reanalyses using the MPI hydrological discharge model  

Microsoft Academic Search

To validate the hydrological cycle of the European Center for Medium-Range Weather Forecasts (ECMWF) and the National Centers for Environmental Prediction (NCEP) reanalyses in comparison with observed river discharge, a hydrological discharge model is used to compute the corresponding river discharge. The HD model requires daily time series of surface runoff and drainage from the soil as input fields. As

Stefan Hagemann; Lydia Dümenil Gates

2001-01-01

58

Testing the usefulness of hydrological models in simulating extreme streamflows for frequency analysis purpose  

NASA Astrophysics Data System (ADS)

Recently, extreme flood events are becoming more uncertain and greater challenge in the world. Flood frequency analysis is a powerful tool to study and evaluate extreme flood events, and also a key step in design of water resources projects. Hydrological models have been used as an important tool for forecasting extreme flood event and design flood calculation. However, there are little studies on evaluation of the reasonability of flood frequency values obtained from runoff simulations of watershed hydrological models. In this study, the reasonability of the flood frequency analysis obtained from runoff simulations of different hydrological models is evaluated and analyzed by comparison with that from historical runoff observation. Xiangjiang basin, one of the most important economic belts in Hunan Province, is selected as the study region. Xiangjiang basin is always in a severe situation for flood control in summer and has also great influences on Dongting Lake's flood storage capacity. In this study Xiangjiang Basin was divided into 3 sub-basins and 1 downstream section, which have their outflow stations respectively. Each region has integrated and long observed historical runoff and rainfall series from 1961 to 2005. Three conceptual hydrological models, i.e., Xin-anjiang, HBV and WASMOD were established to simulate runoff in each sub-basins of Xiangjiang basin. To utilize the simulations from three hydrological models for frequency analysis, a transformation from deterministic rain-runoff models to stochastic models is needed by adding the model residuals to the simulated discharges using Monte-Carlo method. The commonly used Pearson type III distribution in China and L-moment were used to calculate the frequency. All three hydrological models perform well according to commonly used model evaluation criteria, i.e., Nash-Sutcliffe model efficiency coefficient and water balance error, etc. However, the frequency analysis results of annual maximum flow simulated by three models are rather different. The study provided a detailed explanation and evaluation in the possible usefulness of hydrological models in flood frequency studies. Keywords: Climate change; Flood frequency analysis; hydrological models, Xiangjiang basin; China

Chen, H.; Li, L.; Wang, J.; Xu, C.-Y.; Guo, S.

2012-04-01

59

Proving the ecosystem value through hydrological modelling  

NASA Astrophysics Data System (ADS)

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. In addition can be stated that the loss of detention due to land use and dikes can be called an externality and results in economic inefficiencies.

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

2008-11-01

60

Macroscale hydrologic modeling of ecologically relevant flow metrics  

Microsoft Academic Search

Stream hydrology strongly affects the structure of aquatic communities. Changes to air temperature and precipitation driven by increased greenhouse gas concentrations are shifting timing and volume of streamflows potentially affecting these communities. The variable infiltration capacity (VIC) macroscale hydrologic model has been employed at regional scales to describe and forecast hydrologic changes but has been calibrated and applied mainly to

Seth J. Wenger; Charles H. Luce; Alan F. Hamlet; Daniel J. Isaak; Helen M. Neville

2010-01-01

61

Modelling the hydrological cycle in assessments of climate change  

Microsoft Academic Search

Climate change caused by increasing atmospheric concentrations of greenhouse gases may have important effects on water circulation and availability and thus on agriculture, forestry and river flow, with significant economic consequences. A variety of models are being used to evaluate hydrological effects, but their hydrological responses to global warming are often inconsistent. Improved understanding of basic hydrological processes is needed

D. Rind; C. Rosenzweig; R. Goldberg

1992-01-01

62

Multivariate Probabilistic Analysis of an Hydrological Model  

NASA Astrophysics Data System (ADS)

Model predictions derived based on rainfall measurements and hydrological model results are often limited by the systematic error of measuring instruments, by the intrinsic variability of the natural processes and by the uncertainty of the mathematical representation. We propose a means to identify such sources of uncertainty and to quantify their effects based on point-estimate approaches, as a valid alternative to cumbersome Montecarlo methods. We present uncertainty analyses on the hydrologic response to selected meteorological events, in the mountain streamflow-generating portion of the Brenta basin at Bassano del Grappa, Italy. The Brenta river catchment has a relatively uniform morphology and quite a heterogeneous rainfall-pattern. In the present work, we evaluate two sources of uncertainty: data uncertainty (the uncertainty due to data handling and analysis) and model uncertainty (the uncertainty related to the formulation of the model). We thus evaluate the effects of the measurement error of tipping-bucket rain gauges, the uncertainty in estimating spatially-distributed rainfall through block kriging, and the uncertainty associated with estimated model parameters. To this end, we coupled a deterministic model based on the geomorphological theory of the hydrologic response to probabilistic methods. In particular we compare the results of Monte Carlo Simulations (MCS) to the results obtained, in the same conditions, using Li's Point Estimate Method (LiM). The LiM is a probabilistic technique that approximates the continuous probability distribution function of the considered stochastic variables by means of discrete points and associated weights. This allows to satisfactorily reproduce results with only few evaluations of the model function. The comparison between the LiM and MCS results highlights the pros and cons of using an approximating method. LiM is less computationally demanding than MCS, but has limited applicability especially when the model response is highly nonlinear. Higher-order approximations can provide more accurate estimations, but reduce the numerical advantage of the LiM. The results of the uncertainty analysis identify the main sources of uncertainty in the computation of river discharge. In this particular case the spatial variability of rainfall and the model parameters uncertainty are shown to have the greatest impact on discharge evaluation. This, in turn, highlights the need to support any estimated hydrological response with probability information and risk analysis results in order to provide a robust, systematic framework for decision making.

Franceschini, Samuela; Marani, Marco

2010-05-01

63

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

NASA Astrophysics Data System (ADS)

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 of process-based and data driven models can provide an alternative modelling approach to prairie hydrology. The approach is capable of representing the highly non-linear nature of the hydrological processes and in particular, the challenging response originating from the hydrologically non-contributing areas.

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

2012-04-01

64

Eco-hydrological modeling to integrate ecological processes and hydrological processes in a small forested catchment  

Microsoft Academic Search

Ecological processes and hydrological processes are very tightly connected with each other. Especially, to estimate the amount of water outflow and water retention in forest, it is needed to quantify the role of vegetation in the forest. For this reason, Eco-hydrological modeling provides an useful tool to understand the forest ecosystem processes and services. But because the numerous processes is

E. Kim; S. Kang; A. Lee; S. Kim; K. Kim; J. Kim; D. Lee

2006-01-01

65

Physical models for classroom teaching in hydrology  

NASA Astrophysics Data System (ADS)

Hydrology teaching benefits from the fact that many important processes can be illustrated and explained with simple physical models. A set of mobile physical models has been developed and used during many years of lecturing at basic university level teaching in hydrology. One model, with which many phenomena can be demonstrated, consists of a 1.0-m-long plexiglass container containing an about 0.25-m-deep open sand aquifer through which water is circulated. The model can be used for showing the groundwater table and its influence on the water content in the unsaturated zone and for quantitative determination of hydraulic properties such as the storage coefficient and the saturated hydraulic conductivity. It is also well suited for discussions on the runoff process and the significance of recharge and discharge areas for groundwater. The flow paths of water and contaminant dispersion can be illustrated in tracer experiments using fluorescent or colour dye. This and a few other physical models, with suggested demonstrations and experiments, are described in this article. The finding from using models in classroom teaching is that it creates curiosity among the students, promotes discussions and most likely deepens the understanding of the basic processes.

Rodhe, A.

2012-09-01

66

Calibration of hydrological models in glacierized catchments  

NASA Astrophysics Data System (ADS)

Glacierized catchments are important source regions for water, and detailed knowledge of water availability is a prerequisite for good resource management strategies. Reliable and physically consistent runoff simulations become even more important if climate change impacts on alpine water resources are to be assessed. However, hydrological modeling of glacierized catchments is challenging ice melt which represents an additional source of water. Thus, adequate calibration strategies are needed especially in data scarce regions. An important question is how powerful a limited amount of data might be for model calibration. Accordingly, we analyzed the calibration power of limited discharge measurements, mass balance observations and the combination of by means of both Monte Carlo analyzes and multi-criteria model performance evaluation. Ensembles of 100 parameter sets were selected by evaluating the simulations based on a limited and discrete number of discharge measurements, glacier mass balance, and the combination of discharge and mass balance observations. Using these ensembles then the runoff was simulated and evaluated for the entire runoff series. The results for the Vernagtferner catchment and the Venter Ache catchment in Austria indicated that a single annual glacier mass balance observation contained useful information to constrain hydrological models. Combining mass balance observations with a few discharge data improved the internal consistency and significantly reduced the uncertainties compared to parameter set selections based on discharge measurements alone. Information on discharge was required for at least 3 days during the melting season to obtain good ensemble predictions.

Konz, Markus; Seibert, Jan; Braun, Ludwig; Burlando, Paolo

2010-05-01

67

Mid-Holocene Hydrologic Model of the Shingobee Watershed, Minnesota  

Microsoft Academic Search

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

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

2002-01-01

68

Hydrological validation of multifractal rainfall simulation models  

NASA Astrophysics Data System (ADS)

The observed scaling invariance properties of rainfall time series have often been put forward to justify the choice of multifractal (scaling) models for rainfall stochastic modelling. These models are nevertheless seldom validated on real hydrological applications. Two types of multifractal models - the first one with a Log-Poisson generator and the second one with a uniform generator - were calibrated on a 8 year point rainfall series with a five minute time step. The results obtained with the rainfall series simulated with these models on two hydrological applications (the computation of intensity-duration-frequency, IDF, curves and the conception of a urban drainage storage volume) were compared with those obtained with the original measured rainfall series. The disagreements reveal some limitations of the multifractal models. On the one hand, using the vocabulary of the multifractalists, the models are calibrated on the basis of the statistical properties of the simulated undressed series while the IDF curves are computed on the dressed series. The statistical properties of both types of series clearly differ if a canonical model is used : here the model with the Log-Poisson generator. On the other hand, the optimal dimensions of the storage volume depend on the shape of the hyetographs. The discordances between the volumes obtained with the simulated or measured rainfall series indicate that the temporal structure of the simulated rainfall intensity series (i.e. the shapes of the simulated hyetographs) are not comparable with the one of the measured series. As a conclusion, multifractal models appear to reproduce accuratly only some of the properties of the real measured series. Their appropriateness should not be a priori asserted but verified for each considered application.

Mouhous, N.; Gaume, E.; Andrieu, H.

2003-04-01

69

Plant growth simulation for landscape scale hydrologic modeling  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

70

Assessment of The Uncertainties of a Conceptual Hydrologic Model By Using Artificially Generated Flows  

NASA Astrophysics Data System (ADS)

Most of the studies that assess the performance of various calibration techniques have to deal with a certain amount of uncertainty in the calibration data. In this study we tested HBV model calibration procedures in hypothetically ideal conditions under the assumption of no errors in the measured data. This was achieved by creating an artificial time series of the flows created by the HBV model using the parameters obtained from calibrating the measured flows. The artificial flows were then used to replace the original flows in the calibration data, which was then used for testing how calibration procedures can reproduce known model parameters. The results showed that in performing one hundred independent calibration runs of the HBV model, we did not manage to obtain parameters that were almost identical to those used to create the artificial flow data without a certain degree of uncertainty. Although the calibration procedure of the model works properly from a practical point of view, it can be regarded as a demonstration of the equifinality principle, since several parameter sets were obtained which led to equally acceptable or behavioural representations of the observed flows. The study demonstrated that this concept for assessing how uncertain hydrological predictions can be applied in the further development of a model or the choice of calibration method using artificially generated data.

Valent, Peter; Szolgay, Ján; Riverso, Carlo

2012-12-01

71

Calibration and validation of DRAINMOD to model bioretention hydrology  

NASA Astrophysics Data System (ADS)

Bioretention hydrology was modeled with DRAINMOD, a widely accepted drainage model. Four bioretention cells monitored for 2 year periods were used in calibration. DRAINMOD can model an internal water storage (IWS) zone configuration. It can be used to predict bioretention hydrology on a continuous, long-term basis. In the validation period, Nash-Sutcliffe coefficients commonly exceeded 0.7.

Brown, R. A.; Skaggs, R. W.; Hunt, W. F.

2013-04-01

72

Modeling hydrologic processes at the residential scale  

NASA Astrophysics Data System (ADS)

In California, urbanization has led to polluted runoff, flooding during winter, and water shortages during summer. There is growing interest in application of microscale hydrologic solutions that eliminate storm runoff and conserve water at the source. In this study, a physically-based numerical model was developed to better understand hydrologic processes at the residential scale and the interaction of these processes among different Best Management Practices (BMPs). This model calculates all in-flow and out-flow using an hourly interval over a full year or for specific storm events. Water enters the system via precipitation and irrigation and leaves the system via evapotranspiration, surface and subsurface runoff, and from percolation to groundwater. The model was applied to two single-family residential parcels in Los Angeles. Two years of data collected from the control and treatment sites were used to calibrate and validate the model. More than 97% of storm runoff to the street was eliminated with installation of low-cost BMPs (i.e., rain gutters that direct roof runoff to a lawn retention basin and a driveway interceptor that directs runoff to a drywell in the lawn retention basin). Evaluated individually, the driveway interceptor was the most effective BMP for storm runoff reduction (65%), followed by the rain gutter installation (28%), and lawn converted to retention basin (12%). Installation of an 11 m3 cistern did not substantially reduce runoff, but did provide storage for 9% of annual irrigation demand. Simulated landscape irrigation demand was reduced 53% by increasing efficiency through use of a drip irrigation system for shrubs, and adjusting monthly application rates based on evapotranspirational water demand. The model showed that infiltration and surface runoff processes were particularly sensitive to the soil's physical properties and its effective depth. If the existing loam soil were replaced by clay soil annual runoff discharge to the street would be increased by 63% when climate and landscape features remained unchanged.

Xiao, Q.; McPherson, G.; Simpson, J.; Ustin, S.

2003-12-01

73

Hydrology  

ERIC Educational Resources Information Center

|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)|

Sharp, John M.

1977-01-01

74

An integrated hydrologic modeling framework for coupling SWAT with MODFLOW  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Soil and Water Assessment Tool (SWAT), MODFLOW, and Energy Balance based Evapotranspiration (EB_ET) models are extensively used to estimate different components of the hydrological cycle. Surface and subsurface hydrological processes are modeled in SWAT but limited to the extent of shallow aquif...

75

AGRICULTURAL WETLAND AND POND HYDROLOGIC ANALYSES USING THE SPAW MODEL  

Technology Transfer Automated Retrieval System (TEKTRAN)

A new computer model has been developed and evaluated to simulate the hydrology of wetlands and ponds located in agricultural settings. The SPAW (Soil-Plant-Air-Water) model consists of two linked routines. The first develops field hydrologic budgets based upon daily climatic data, crop data, and h...

76

Hillslope Hydrologic Response: Integrating Field Observations And Mathematical Modeling  

Microsoft Academic Search

The study is focused on the important and crucial feedback existing between hydrological modeling and field observations and the challenge for hydrologists to adapt model complexity to data availability across a huge variety of spatial and temporal scales. Continuous high-resolution hydrologic observations in a steep forested watershed in Northern California provide a quantitative description of the system behavior during water

A. Uccelli; R. Salve; W. E. Dietrich; I. Fung

2008-01-01

77

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

78

Validation of A Global Hydrological Model  

NASA Astrophysics Data System (ADS)

Freshwater availability has been recognized as a global issue, and its consistent quan- tification not only in individual river basins but also at the global scale is required to support the sustainable use of water. The Global Hydrology Model WGHM, which is a submodel of the global water use and availability model WaterGAP 2, computes sur- face runoff, groundwater recharge and river discharge at a spatial resolution of 0.5. WGHM is based on the best global data sets currently available, including a newly developed drainage direction map and a data set of wetlands, lakes and reservoirs. It calculates both natural and actual discharge by simulating the reduction of river discharge by human water consumption (as computed by the water use submodel of WaterGAP 2). WGHM is calibrated against observed discharge at 724 gauging sta- tions (representing about 50% of the global land area) by adjusting a parameter of the soil water balance. It not only computes the long-term average water resources but also water availability indicators that take into account the interannual and seasonal variability of runoff and discharge. The reliability of the model results is assessed by comparing observed and simulated discharges at the calibration stations and at se- lected other stations. We conclude that reliable results can be obtained for basins of more than 20,000 km2. In particular, the 90% reliable monthly discharge is simu- lated well. However, there is the tendency that semi-arid and arid basins are modeled less satisfactorily than humid ones, which is partially due to neglecting river channel losses and evaporation of runoff from small ephemeral ponds in the model. Also, the hydrology of highly developed basins with large artificial storages, basin transfers and irrigation schemes cannot be simulated well. The seasonality of discharge in snow- dominated basins is overestimated by WGHM, and if the snow-dominated basin is uncalibrated, discharge is likely to be underestimated due to the precipitation mea- surement errors. Even though the explicit modeling of wetlands and lakes leads to a much improved modeling of both the vertical water balance and the lateral transport of water, not enough information is included in WGHM to accurately capture the hy- drology of these water bodies. Certainly, the reliability of model results is highest at the locations at which WGHM was calibrated. The validation indicates that reliability for cells inside calibrated basins is satisfactory if the basin is relatively homogeneous. Analyses of the few available stations outside of calibrated basins indicate a reason- ably high model reliability, particularly in humid regions.

Doell, P.; Lehner, B.; Kaspar, F.; Vassolo, S.

79

A novel approach to parameter uncertainty analysis of hydrological models: Application of machine learning techniques  

NASA Astrophysics Data System (ADS)

Monte Carlo (MC) simulation-based techniques are widely used for analyzing parameter uncertainty in hydrological models. Although MC simulations are flexible and robust, and capable of solving a great variety of problems, they are not always practicable for computationally intensive models. This study presents a novel approach for assessment of parameter uncertainty in hydrological models using machine learning techniques. The presented approach replicates MC simulation by using various machine learning techniques, which is subsequently used for assessment of model parametric uncertainty. It is assumed a hydrological model M(p) is given and the propagation of the uncertainty in parameters p to the output is to be investigated. MC simulation of model M(p) is run and the stored realizations are used to form the dataset for training machine learning models. One of the issues was selection of the input variables for the machine learning models; it was done by searching for the variables (or their transformed variants) with the highest relatedness (average mutual information) to the sought distribution of the model M output. Machine learning models are trained to approximate the functional relationships between the variables characterizing the process modelled by M(p) and the uncertainty descriptors of its output. The trained machine learning models encapsulate the underlying characteristics of the parameter uncertainty and can be used to predict uncertainty descriptors for the new data. In this study three machine learning models - artificial neural networks, model trees and locally weighted regressions are used. The approach was demonstrated by estimating parameter uncertainty of a lumped conceptual hydrological model, HBV with application to a case study of meso scale mountainous catchment of Nepal. Uncertainty measures such as prediction intervals estimated by three machine learning methods are compared to those obtained by MC simulation in verification period. The results are promising as the uncertainty measures estimated by machine learning models are reasonably accurate. The proposed technique could be useful in real time applications for computationally intensive models (e.g. physically based hydrological models) which require run times that make traditional MC analysis impractical and when the forecast lead time is very short.

Shrestha, D. L.; Kayastha, N.; Solomatine, D. P.

2009-04-01

80

Assessing The Performance of Hydrological Models  

NASA Astrophysics Data System (ADS)

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

van der Knijff, Johan

81

Updating of states in operational hydrological models  

NASA Astrophysics Data System (ADS)

Operationally the main purpose of hydrological models is to provide runoff forecasts. The quality of the model state and the accuracy of the weather forecast together with the model quality define the runoff forecast quality. Input and model errors accumulate over time and may leave the model in a poor state. Usually model states can be related to observable conditions in the catchment. Updating of these states, knowing their relation to observable catchment conditions, influence directly the forecast quality. Norway is internationally in the forefront in hydropower scheduling both on short and long terms. The inflow forecasts are fundamental to this scheduling. Their quality directly influence the producers profit as they optimize hydropower production to market demand and at the same time minimize spill of water and maximize available hydraulic head. The quality of the inflow forecasts strongly depends on the quality of the models applied and the quality of the information they use. In this project the focus has been to improve the quality of the model states which the forecast is based upon. Runoff and snow storage are two observable quantities that reflect the model state and are used in this project for updating. Generally the methods used can be divided in three groups: The first re-estimates the forcing data in the updating period; the second alters the weights in the forecast ensemble; and the third directly changes the model states. The uncertainty related to the forcing data through the updating period is due to both uncertainty in the actual observation and to how well the gauging stations represent the catchment both in respect to temperatures and precipitation. The project looks at methodologies that automatically re-estimates the forcing data and tests the result against observed response. Model uncertainty is reflected in a joint distribution of model parameters estimated using the Dream algorithm.

Bruland, O.; Kolberg, S.; Engeland, K.; Gragne, A. S.; Liston, G.; Sand, K.; Tøfte, L.; Alfredsen, K.

2012-04-01

82

A hydrological model of New Zealand  

NASA Astrophysics Data System (ADS)

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.

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

2003-04-01

83

Hydrology  

NASA Astrophysics Data System (ADS)

Water in its different forms has always been a source of wonder, curiosity and practical concern for humans everywhere. Hydrology - An Introduction presents a coherent introduction to the fundamental principles of hydrology, based on the course that Wilfried Brutsaert has taught at Cornell University for the last thirty years. Hydrologic phenomena are dealt with at spatial and temporal scales at which they occur in nature. The physics and mathematics necessary to describe these phenomena are introduced and developed, and readers will require a working knowledge of calculus and basic fluid mechanics. The book will be invaluable as a textbook for entry-level courses in hydrology directed at advanced seniors and graduate students in physical science and engineering. In addition, the book will be more broadly of interest to professional scientists and engineers in hydrology, environmental science, meteorology, agronomy, geology, climatology, oceanology, glaciology and other earth sciences. Emphasis on fundamentals Clarification of the underlying physical processes Applications of fluid mechanics in the natural environment

Brutsaert, Wilfried

2005-08-01

84

Global scale hydrology - Advances in land surface modeling  

SciTech Connect

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.

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

1991-01-01

85

Distributed Hydrologic Models for Flow Forecasts - Part 2  

NSDL National Science Digital Library

Distributed Hydrologic Models for Flow Forecasts Part 2 is the second release in a two-part series focused on the science of distributed models and their applicability to different flow forecasting situations. Presented by Dr. Dennis Johnson, the module provides a more detailed look at the processes and mechanisms involved in distributed hydrologic models. It examines the rainfall/runoff component, snowmelt, overland flow routing, and channel response in a basin as represented in a distributed model. Calibration issues and situations in which distributed hydrologic models might be most appropriate are also addressed.

2011-01-01

86

Comparing the performance of different model structures with respect to different hydrological signatures  

NASA Astrophysics Data System (ADS)

Correctly representing the dominant flow generation processes in conceptual rainfall-runoff models is crucial for ensuring adequate predictive power of the models. Recent work showed that on the small scale uniqueness of place requires different model structures for different catchments and that different calibration strategies frequently result in a wide range of model parameter sets. In this study we investigate the following research questions: (1) What is the effect of different calibration objective functions on the model performance? (2) Can the difference in performance of specific objective functions be related to hydrological signatures and physical catchment characteristics. Data from four experimental (approx. 1000 km2) sub-catchments (Alzette, Kyll, Orne and Seille) of the Moselle were used in this study. Eleven conceptual model structures (HBV, GR4J and 9 SUPERFLEX (flexible) model structures) of varying level of complexity are applied on each of the four study catchments. Besides classical objective functions (eg. Nash-Sutcliffe efficiency), additional objective functions are defined based on several hydrological signatures, such as the flow duration curve, rising limb density and auto-correlation. A multi-objective optimization is performed on all the objective functions for each catchment and each model structure considered. The results of the multi-objective optimization are then compared using Principle Component Analysis in order to identify the causes for differences in performance in the objective functions and relate these to physical catchment characteristics such as elevation, shape of the catchment and the height distribution above the nearest drain within a catchment. If such relationships are found then they can help to a priori identify suitable model structures and hydrological signatures in a catchment, given its spatial scale and physical characteristics.

Euser, T.; Winsemius, H. C.; Hrachowitz, M.; Fenicia, F.; Savenije, H. H. G.

2012-04-01

87

Chapman Conference on Spatial Variability in Hydrologic Modeling  

Microsoft Academic Search

The AGU Chapman Conference on Spatial Variability in Hydrologic Modeling was held July 21-23, 1981, at the Colorado State University Pingree Park Campus, located in the mountains some 88.5 km (55 miles) west of Fort Collins, Colorado. The conference was attended by experimentalists and theoreticians from a wide range of disciplines, including geology, hydrology, civil engineering, watershed science, chemical engineering,

D. A. Woolhiser; H. J. Morel-Seytoux

1982-01-01

88

FIELD AND POND HYDROLOGIC ANALYSES WITH THE SPAW MODEL  

Technology Transfer Automated Retrieval System (TEKTRAN)

The SPAW (Soil-Plant-Air-Water) computer model simulates the daily hydrology of agricultural fields and ponds including wetlands, lagoons and reservoirs. Field hydrology is represented by daily climatic descriptions of rainfall, temperature and evaporation; a layered soil profile with automated wat...

89

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

NASA Astrophysics Data System (ADS)

This paper presents the concept, first results and perspectives of the hydrological sub-project of the IMPETUS-Benin project which is part of the GLOWA program funded by the German ministry of education and research. In addition to the research concept, first results on field hydrology, pedology, hydrogeology and hydrological modelling are presented, focusing on the understanding of the actual hydrological processes. For analysing the processes a 30 km2 catchment acting as a super test site was chosen which is assumed to be representative for the entire catchment of about 15,000 km2. First results of the field investigations show that infiltration, runoff generation and soil erosion strongly depend on land cover and land use which again influence the soil properties significantly. A conceptual hydrogeological model has been developed summarising the process knowledge on runoff generation and subsurface hydrological processes. This concept model shows a dominance of fast runoff components (surface runoff and interflow), a groundwater recharge along preferential flow paths, temporary interaction between surface and groundwater and separate groundwater systems on different scales (shallow, temporary groundwater on local scale and permanent, deep groundwater on regional scale). The findings of intensive measurement campaigns on soil hydrology, groundwater dynamics and soil erosion have been integrated into different, scale-dependent hydrological modelling concepts applied at different scales in the target region (upper Ouémé catchment in Benin, about 15,000 km2). The models have been applied and successfully validated. They will be used for integrated scenario analyses in the forthcoming project phase to assess the impacts of global change on the regional water cycle and on typical problem complexes such as food security in West African countries.

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

90

Hydrologic Modeling of the Devils Lake Basin Watersheds.  

National Technical Information Service (NTIS)

The report outlines the progress made in developing a comprehensive hydrologic simulation model of the Devils Lake Basin (DLB) and its constituent watersheds. The simulation model being developed for the DLB is an explicit soil moisture accounting (ESMA) ...

B. M. Parekh

1976-01-01

91

Using GRACE data to improve global hydrological modeling  

NASA Astrophysics Data System (ADS)

This contribution will present the joint results of the project REGHYDRO (in the framework of the German priority program "Mass transport and mass distribution in system Earth") which constitutes a cooperation between geodesists, hydrologists, and mathematicians to exploit the mutual benefits of GRACE gravity field analysis and hydrological modeling. One goal of the project is the improvement of global-scale hydrological modeling of water storage variations (and water flows) using gravity field variations from GRACE. The WaterGAP Global Hydrology Model (WGHM) has recently been expanded to introduce the withdrawal of groundwater into the model. This is the first time that this contribution is included into a global hydrological model. GRACE data is then used to validate the results and adjust the assumptions made in the modeling. Results will be presented from the test area in the High Plains Aquifer region.

Eicker, A.; Kurtenbach, E.; Doell, P.; Hoffmann-Dobrev, H.; Kusche, J.

2011-12-01

92

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

Microsoft Academic Search

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.

A. Valainis; A. Timuhin; U. Bethers

2009-01-01

93

A novel approach to Monte Carlo-based uncertainty analysis of hydrological models using artificial neural networks  

NASA Astrophysics Data System (ADS)

The presented approach replicates Monte Carlo (MC) simulation by using an Artificial Neural Network (ANN), which is subsequently used for assessment of model parametric uncertainty. It is assumed a hydrological model M(p) is given and the propagation of the uncertainty in parameters p to the output is to be investigated. MC simulation of model M(p) is run and the stored realizations are used to form the dataset for training an ANN. One of the issues was selection of the input variables for the ANN model; it was done by searching for the variables (or their transformed variants) with the highest relatedness (average mutual information) to the sought distribution of the model M output. ANN is trained to approximate the functional relationships between the variables characterizing the process modelled by M(p) and the uncertainty descriptors of its output. The trained ANN model encapsulates the underlying characteristics of the parameter uncertainty and can be used to predict uncertainty descriptors for the new data. The approach was validated by comparing the uncertainty descriptors in the verification data set with those obtained by MC simulation. The method is applied to estimate parameter uncertainty of a lumped conceptual hydrological model, HBV. The results are promising as the prediction intervals estimated by ANN are reasonably accurate. The proposed techniques could be useful in real time applications when it is not possible to run a large number of simulations for complex hydrological models and when the forecast lead time is very short.

Shrestha, D. L.; Kayastha, N.; Solomatine, D.

2009-04-01

94

Hydrological responses to dynamically and statistically downscaled climate model output  

USGS Publications Warehouse

Daily rainfall and surface temperature series were simulated for the Animas River basin, Colorado using dynamically and statistically downscaled output from the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) re-analysis. A distributed hydrological model was then applied to the downscaled data. Relative to raw NCEP output, downscaled climate variables provided more realistic stimulations of basin scale hydrology. However, the results highlight the sensitivity of modeled processes to the choice of downscaling technique, and point to the need for caution when interpreting future hydrological scenarios.

Wilby, R. L.; Hay, L. E.; Gutowski, Jr. , W. J.; Arritt, R. W.; Takle, E. S.; Pan, Z.; Leavesley, G. H.; Clark, M. P.

2000-01-01

95

Two-dimensional hydrologic modeling to evaluate aquatic habitat ...  

Treesearch

Title: Two-dimensional hydrologic modeling to evaluate aquatic habitat conditions ... physical and biological parameters such as temperature, dissolved oxygen, ... Government employees on official time, and is therefore in the public domain.

96

Applying the SWAT hydrologic model on a watershed containing ...  

Treesearch

Title: Applying the SWAT hydrologic model on a watershed containing forested ... US Forest Service Center for Forested Wetlands Research is working on a South ... 319 Grant Program funded Total Maximum Daily Load (TMDL) project for the ...

97

Toward improved calibration of hydrologic models: Multiple and noncommensurable measures of information  

Microsoft Academic Search

Several contributions to the hydrological literature have brought into question the continued usefulness of the classical paradigm for hydrologic model calibration. With the growing popularity of sophisticated \\

Hoshin Vijai Gupta; Soroosh Sorooshian; Patrice Ogou Yapo

1998-01-01

98

Assessing Hydrological Extreme Events with Geospatial Data and Models  

NASA Astrophysics Data System (ADS)

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.

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

2004-09-01

99

Hydrological minimal model for fire regime assessment in Mediterranean ecosystem  

NASA Astrophysics Data System (ADS)

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.

Ursino, N.; Rulli, M. C.

2012-04-01

100

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

Microsoft Academic Search

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

W. C. Visser

101

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

Microsoft Academic Search

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

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

102

The transferability of hydrological models under nonstationary climatic conditions  

NASA Astrophysics Data System (ADS)

This paper investigates issues involved in calibrating hydrological models against observed data when the aim of the modelling is to predict future runoff under different climatic conditions. To achieve this objective, we tested two hydrological models, DWBM and SIMHYD, using data from 30 unimpaired catchments in Australia which had at least 60 yr of daily precipitation, potential evapotranspiration (PET), and streamflow data. Nash-Sutcliffe efficiency (NSE), modified index of agreement (d1) and water balance error (WBE) were used as performance criteria. We used a differential split-sample test to split up the data into 120 sub-periods and 4 different climatic sub-periods in order to assess how well the calibrated model could be transferred different periods. For each catchment, the models were calibrated for one sub-period and validated on the other three. Monte Carlo simulation was used to explore parameter stability compared to historic climatic variability. The chi-square test was used to measure the relationship between the distribution of the parameters and hydroclimatic variability. The results showed that the performance of the two hydrological models differed and depended on the model calibration. We found that if a hydrological model is set up to simulate runoff for a wet climate scenario then it should be calibrated on a wet segment of the historic record, and similarly a dry segment should be used for a dry climate scenario. The Monte Carlo simulation provides an effective and pragmatic approach to explore uncertainty and equifinality in hydrological model parameters. Some parameters of the hydrological models are shown to be significantly more sensitive to the choice of calibration periods. Our findings support the idea that when using conceptual hydrological models to assess future climate change impacts, a differential split-sample test and Monte Carlo simulation should be used to quantify uncertainties due to parameter instability and non-uniqueness.

Li, C. Z.; Zhang, L.; Wang, H.; Zhang, Y. Q.; Yu, F. L.; Yan, D. H.

2012-04-01

103

Assessing hydrologic response to climate change of a stream watershed using SLURP hydrological model  

Microsoft Academic Search

The impact on streamflow and groundwater recharge considering future potential climate and land use changes was assessed using\\u000a Semi-distributed Land-Use Runoff Process (SLURP) continuous hydrologic model. The model was calibrated and verified using\\u000a 4 years (1999–2002) daily observed streamflow data for a 260.4 km2 watershed which has been continuously urbanized during the past couple of decades. The model was calibrated

So Ra Ahn; Geun Ae Park; In Kyun Jung; Kyoung Jae Lim; Seong Joon Kim

2011-01-01

104

Hydrologic Predictions in the Anthropocene: Exploration with Co-evolutionary Socio-hydrologic Models  

NASA Astrophysics Data System (ADS)

Socio-hydrology studies the co-evolution and self-organization of humans in the hydrologic landscape, which requires a thorough understanding of the complex interactions between humans and water. On the one hand, the nature of water availability greatly impacts the development of society. On the other hand, humans can significantly alter the spatio-temporal distribution of water and in this way provide feedback to the society itself. The human-water system functions underlying such complex human-water interactions are not well understood. Exploratory models with the appropriate level of simplification in any given area can be valuable to understand these functions and the self-organization associated with socio-hydrology. In this study, a simple coupled modeling framework for socio-hydrology co-evolution is developed, and is used to illustrate the explanatory power of such models. In the Tarim River, humans depend heavily on agricultural production (other industries can be ignored for a start), and the social processes can be described principally by two variables, i.e., irrigated-area and human population. The eco-hydrological processes are expressed in terms of area under natural vegetation and stream discharge. The study area is the middle and the lower reaches of the Tarim River, which is divided into two modeling units, i.e. middle reach and lower reach. In each modeling unit, four ordinary differential equations are used to simulate the dynamics of the hydrological system represented by stream discharge, ecological system represented by area under natural vegetation, the economic system represented by irrigated area under agriculture and social system represented by human population. The four dominant variables are coupled together by several internal variables. For example, the stream discharge is coupled to irrigated area by the colonization rate and mortality rate of the irrigated area in the middle reach and the irrigated area is coupled to stream discharge by water used for irrigation. In a similar way, the stream discharge and natural vegetation are coupled together. The irrigated area is coupled to population by the colonization rate and mortality rate of the population. The discharge of the lower reach is determined by the discharge from the middle reach. The natural vegetation area in the lower reach is coupled to the discharge in the middle reach by water resources management policy. The co-evolution of the Tarim socio-hydrological system is then analyzed within this modeling framework to gain insights into the overall system dynamics and sensitivity to the external drivers and internal system variables.

Sivapalan, Murugesu; Tian, Fuqiang; Liu, Dengfeng

2013-04-01

105

Modelling impacts of climate change on the hydrology of a Mongolian catchment using an appropriate permafrost conceptualization  

NASA Astrophysics Data System (ADS)

Climate change is expected to have considerable impacts on global water resources. Regional impacts will vary considerably depending on climatological, geographical and hydrological characteristics. A region which is particularly vulnerable to climate change is Central Asia. Precipitation in this area is low and highly variable in space and time, and river discharges are largely dependent on the melting of snow and ice. Changes in temperature and precipitation may seriously affect the timing, duration and intensity of high and low flows and hence water availablity in downstream areas. Mongolia is an example of a country where several of these vulnerable catchments can be found. Permafrost conditions prevail in large parts of the country and have a substantial influence on catchment hydrology, which might be altered by climate change. The objective of this study is to determine the impacts of future climate change on the hydrology of a Mongolian catchment, the Buyant River, taking into account permafrost conditions. This is done in two steps. First, four different permafrost conceptualizations within an existing conceptual hydrological model (HBV) are compared to select the most appropriate one. Two conceptualizations take permafrost into account by only calibrating under non-permafrost (summer) conditions and differ in their elevation representation of the catchment (single and multiple elevation zones). The other two conceptualizations explicitly simulate permafrost conditions by adding freezing and melt functions and an ice store to each of the three water stores of HBV. Five years have been used for calibration and five years for validation. Second, the impact of climate change on the hydrology of the Buyant River is determined by using the outputs of four Global Circulation Models (GCMs) for three SRES emission scenarios in HBV with the most appropriate permafrost conceptualization. The delta change method is used to translate output from GCMs to climate time series for future conditions. Results in the calibration are moderate to good for the conceptualizations with an explicit simulation of permafrost, where the model with one elevation zone performs better in the validation than the model with multiple elevation zones. The other two conceptualizations perform poor to moderate, particularly because groundwater flow persists in winter despite that this period is not considered in the calibration of these cases. The HBV model with explicit permafrost simulation and one elevation zone is used for climate change impact assessment. For the period 2080-2100, the discharge of the Buyant River is likely to increase in spring and most probably will decrease in summer and autumn, for some combinations of GCMs and scenarios considerably. Uncertainties in climate change impacts are large, where the uncertainty due to different GCMs is found to be more important than the uncertainty due to different scenarios. Additionally, uncertainties in downscaling, data and hydrological model structure and parameters can further complicate the analysis of the catchment's response to climate change.

Heerema, Kor; Booij, Martijn J.; Huting, Ric; Warmink, Jord J.; van Beek, Eelco; Jigjsuren, Odgarav

2013-04-01

106

Updating the snow reservoir in hydrological models from satellite derived snow covered area  

NASA Astrophysics Data System (ADS)

It has been a longstanding wish to be able to update the snow reservoir in hydrological models with observed data in order to successfully simulate the spring runoff. Satellite derived snow covered area (SCA) has remained a promising means to this end for decades. Central to this study is that a strict analytical control of the spatial distribution of SWE is necessary for such an endeavour. The spatial distribution of snow water equivalent (SWE) and snowmelt are modelled as sums of correlated gamma distributed variables. Changes in modelled SCA derive from an assessment of the spatial frequencies of the accumulation- and melt distribution respectively. This principle also is applied when satellite derived SCA is retrieved and found different from that modelled. Observed SCA less than modelled triggers a "melting event" which result give matching SCA, and the accumulation distribution is adjusted with the "melted" amount. Observed SCA greater than modelled also triggers "a melting event", but with the observed SCA as point of departure. The simulated accumulation distribution is again adjusted with the "melted amount". The snow distribution model and the updating algorithms are implemented in the Nordic HBV model. Preliminary testing for alpine catchments shows that modelled SCA and SWE both are corrected in the direction suggested by the satellite derived SCA.

Skaugen, T.; Randen, F.

2012-04-01

107

Neural network modelling of non-linear hydrological relationships  

NASA Astrophysics Data System (ADS)

Two recent studies have suggested that neural network modelling offers no worthwhile improvements in comparison to the application of weighted linear transfer functions for capturing the non-linear nature of hydrological relationships. The potential of an artificial neural network to perform simple non-linear hydrological transformations under controlled conditions is examined in this paper. Eight neural network models were developed: four full or partial emulations of a recognised non-linear hydrological rainfall-runoff model; four solutions developed on an identical set of inputs and a calculated runoff coefficient output. The use of different input combinations enabled the competencies of solutions developed on a reduced number of parameters to be assessed. The selected hydrological model had a limited number of inputs and contained no temporal component. The modelling process was based on a set of random inputs that had a uniform distribution and spanned a modest range of possibilities. The initial cloning operations permitted a direct comparison to be performed with the equation-based relationship. It also provided more general information about the power of a neural network to replicate mathematical equations and model modest non-linear relationships. The second group of experiments explored a different relationship that is of hydrological interest; the target surface contained a stronger set of non-linear properties and was more challenging. Linear modelling comparisons were performed against traditional least squares multiple linear regression solutions developed on identical datasets. The reported results demonstrate that neural networks are capable of modelling non-linear hydrological processes and are therefore appropriate tools for hydrological modelling.

Abrahart, R. J.; See, L. M.

2007-09-01

108

Spatial interpolation schemes of daily precipitation for hydrologic modeling  

Microsoft Academic Search

Distributed hydrologic models typically require spatial estimates of precipitation interpolated from sparsely located observational\\u000a points to the specific grid points. We compare and contrast the performance of regression-based statistical methods for the\\u000a spatial estimation of precipitation in two hydrologically different basins and confirmed that widely used regression-based\\u000a estimation schemes fail to describe the realistic spatial variability of daily precipitation field.

Yeonsang Hwang; Martyn Clark; Balaji Rajagopalan; George Leavesley

109

Hydrologic Modeling Strategy for the Islamic Republic of Mauritania, Africa  

USGS Publications Warehouse

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.

Friedel, Michael J.

2008-01-01

110

INTEGRATED RIVER BASIN OPTIMIZATION: MODELING ECONOMIC AND HYDROLOGIC INTERDEPENDENCE  

Microsoft Academic Search

This paper presents an integrated optimal control model that optimizes economic performance of reservoir manage- ment in watersheds in which there are significant economic and hydrologic interdependencies. The model is solved using the Gener- al Algebraic Modeling System (GAMS). Results show that applica- tion of this model to New Mexico's Rio Chama basin can increase total system benefits over historical

Frank A. Ward; Thomas P Lynch

1996-01-01

111

Open source data assimilation framework for hydrological modeling  

NASA Astrophysics Data System (ADS)

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 processes from a different domain or have different spatial and temporal resolutions. An open source framework that bridges OpenMI and OpenDA is presented. The framework provides a generic and easy means for any OpenMI compliant model to assimilate observation measurements. An example test case will be presented using MikeSHE, and OpenMI compliant fully coupled integrated hydrological model that can accurately simulate the feedback dynamics of overland flow, unsaturated zone and saturated zone.

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

2013-04-01

112

Top Down Modeling and Catchment Classification: Insight into hydrologic processes/function and hydrologic similarity  

NASA Astrophysics Data System (ADS)

Catchment classification is an active area of study in catchment hydrology. In order for classification to be useful, dominant catchment functions must be identified. Using a Top down modeling approach, we gain the ability to offer insight into the complexity of catchment functions. This study applies a range of 16 different model complexities, ranging from simple to complex, to approximately 300 catchments across the United States. We apply a Monte Carlo parameter calibration, as well as use of apriori physical information about the catchment to estimate model parameter values. We evaluate simulated streamflow from these models with respect to streamflow signatures that exist at different time scales in order to validate different models at these time scales (daily, monthly, seasonally, inter-annually). The end result of this study is to provide a method to quantify the functional structure from model performance based on model complexity of a catchment and compare these with signatures that are typically assumed to capture hydrologic behavior (ie. Baseflow Index). This result can then be compared to other catchment classification studies with respect to catchment function complexity, and progress can be made toward the connection between physical properties, streamflow signatures, and hydrologic processes/functions.

Sawicz, K. A.; Wagener, T.; Sivapalan, M.; Troch, P. A.; Carrillo, G. A.

2011-12-01

113

Using satellite precipitation data for hydrological modeling  

NASA Astrophysics Data System (ADS)

The growing demand for precipitation data covering larger areas of the globe as lead to the need of innovative approaches to the operationalization of data streams. One possible classical solution is combining and calibrating various ground radar stations, however the availability and cost of these data streams work against its use for global coverage . The alternative is to use Earth Observation data from satellites. There is a wide range of weather data available from polar orbital satellites with sensors for measurements. The biggest advantage is that the spatial coverage is wide, however the temporal resolution for the covered area is more limited. To take advantage of the better of two worlds, geostationary satellites can be used to give the temporal resolution for the same covered area at a regular interval. EUMETSAT's Multi-Sensor Precipitation Estimate (MPE) is based on a classical blending algorithm. This algorithm combines SSM/I instruments on DMSP satellites with the 10.8 micron IR window channel on Meteosat satellites. The result is precipitation estimates with a spatial coverage on most of Europe and Africa and a temporal resolution of 15 minutes. To be able to receive the latest MPE data from EUMETSAT in near real-time a reception station for EUMETCast needs to be set up. With this reception station all data received from Meteosat satellites can be acquired as well as third-party products. The data is post-processed by Meteorological Products Extraction Facility of EUMETSAT, mostly for correction of image distortion and quality assurance. Due to this the data is received with a delay of about 15 minutes. MPE data is stored, by default, in Geostationary Satellite View projection and needs to be transformed into a usable projection system. Projections are translated into WGS84 after which they can be interpolated onto a regular spaced latitude/longitude grid. This paper handles the description of the process of transformation and interpolation strategies for the MPE data. Since the MPE data is an estimate rather than a measurement, the data presents the need for validation. Comparison of the MPE data with ground radar and ground measurements will show the usability for hydrological modeling according to realistic scenarios. The end purpose is improving precipitation estimates by calibration, using ground radar and ground measurements where available. This study also researches their relations and combination approach.

Commandeur, Tom

2013-04-01

114

Models for hydrologic design of evapotranspiration landfill covers.  

PubMed

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. PMID:16201652

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

2005-09-15

115

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

Microsoft Academic Search

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

F. G. Berhane; R. O. Anyah

2010-01-01

116

Comparison of hydrological impacts of climate change simulated by six hydrological models in the Dongjiang Basin, South China  

Microsoft Academic Search

Large differences in future climatic scenarios found when different global circulation models (GCMs) are employed have been extensively discussed in the scientific literature. However, differences in hydrological responses to the climatic scenarios resulting from the use of different hydrological models have received much less attention. Therefore, comparing and quantifying such differences are of particular importance for the water resources management

Tao Jiang; Yongqin David Chen; Chong-Yu Xu; Xiaohong Chen; Xi Chen; Vijay P. Singh

2007-01-01

117

MODIS-derived Potential Evapotranspiration Estimates for Operational Hydrologic Modeling  

Microsoft Academic Search

The current SACramento Soil Moisture Accounting Model (SAC-SMA), used by the National Weather Service, is the primarily model for hydrologic forecasting across the United States. Potential evapotranspiration (PET), one of the required inputs, remains rather simplistic. The model traditionally uses a regional pan evaporation estimate due to the difficulty in acquiring more sophisticated measurements. This study explores an alternative methodology

J. Kim; T. Hogue

2005-01-01

118

Parameterisation, calibration and validation of distributed hydrological models  

Microsoft Academic Search

This paper emphasizes the different requirements for calibration and validation of lumped and distributed models. On the basis of a theoretically founded modelling protocol, the different steps in distributed hydrological modelling are illustrated through a case study based on the MIKE SHE code and the 440km2 Karup catchment in Denmark. The importance of a rigorous and purposeful parameterisation is emphasized

Jens Christian Refsgaard

1997-01-01

119

Modelling hydrological effects of climate change on a global scale  

NASA Astrophysics Data System (ADS)

Multiple studies investigating the hydrological effects of climate change have been performed based on Global Circulation Model (GCM) outputs. However, most of these studies included only one or a few GCM's and focused on single catchments or specific regions. In this study we attempt to use data from all GCM's, for which complete datasets are provided by the IPCC data portal, and investigate the hydrological effects on a global scale to see in which regions detectable trends occur. The hydrological runs are performed with the global distributed model PCR-GLOBWB, developed at Utrecht University. In the first stage of this project the model has been run for the reference period 1961-1990 with the different GCM datasets. From these runs we obtained an indication of the skill of the different climate models to reproduce current hydrological conditions. Results have been compared with measured discharges from the GRDC dataset and with a control run, where the hydrological model is run with the CRU dataset downscaled with ERA40 re-analysis data. Notable is the spread in results for the different GCM based runs, emphasizing the large uncertainty.

Sperna Weiland, F. C.; van Beek, L. P. H.; Kwadijk, J. C. J.; Bierkens, M. F. P.

2009-04-01

120

Study of Parameters And Methods of LL? Distributed Hydrological Model in DMIP2  

Microsoft Academic Search

: The Physics-based distributed hydrological model is considered as an important developing period from the traditional experience-hydrology to the physical hydrology. The Hydrology Laboratory of the NOAA National Weather Service proposes the first and second phase of the Distributed Model Intercomparison Project (DMIP)?that it is a great epoch-making work. LL distributed hydrological model has been developed to the fourth generation

L. Li; J. Wu; X. Wang; C. Yang; Y. Zhao; H. Zhou

2008-01-01

121

Linking Hydrology and Atmospheric Sciences in Continental Water Dynamics Modeling  

NASA Astrophysics Data System (ADS)

Atmospheric observation and model output datasets as well as hydrologic datasets are increasingly becoming available on a continental scale. Although the availability of these datasets could allow large-scale water dynamics modeling, the different objects and semantics used in atmospheric science and hydrology set barriers to their interoperability. Recent work has demonstrated the feasibility for modeling terrestrial water dynamics for the continental United States of America. Continental water dynamics defines the interaction of the hydrosphere, the land surface and subsurface at spatial scales ranging from point to continent. The improved version of the National Hydrographic Dataset (NHDPlus, an integrated suite of geospatial datasets stored in a vector and raster GIS format) was used as hydrologic and elevation data input to the Noah community Land Surface Model, developed at NCAR. Noah was successfully run on a watershed in the Ohio River Basin with NHDPlus inputs. The use of NHDPlus as input data for Noah is a crucial improvement for community modeling efforts allowing users to by-pass much of the time consumed in Digital Elevation Model and hydrological network processing. Furthermore, the community Noah land surface model, in its hydrologically-enhanced configuration, is capable of providing flow inputs for a river dynamics model. Continued enhancement of Noah will, as a consequence, be beneficial to the atmospheric science community as well as to the hydrologic community. Ongoing research foci include using a diversity of weather drivers as an input to Noah, and investigation of how to use land surface model outputs for river forecasting, using both the ArcHydro and OpenMI frameworks.

David, C. H.; Gochis, D. J.; Maidment, D. R.; Wilhelmi, O.

2006-12-01

122

Scaling of input data for macroscale hydrologic modeling  

SciTech Connect

Hydrologic models provide the land-phase link between atmospheric models and oceanographic models within the global water cycle. They provide independent validation of the outputs from atmospheric models and may also provide a mechanism to examine the implications of climatic change on water resources. To form a component of a global model, hydrologic models must be applicable at macroscale and continental scale. The sources and scales of input data are critical to the development of such models. Results from the application of a distributed hydrologic model to Canadian watersheds from 500 km{sup 2} to 1.6 million km{sup 2} in area are used to compare errors found using input data at different scales. Data considered include land cover, vegetation index, and snow water equivalent from satellite sensors and distributed climate data from a general circulation model and from numerical weather prediction models. Analysis of the results allows a consideration of appropriate data scaling in the development of macroscale hydrologic models. 35 refs., 7 figs., 5 tabs.

Kite, G.W. [National Hydrology Research Inst., Saskatoon, Saskatchewan (Canada)

1995-11-01

123

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...

124

An integrated modeling environment within the CUAHSI Hydrologic Information System  

NASA Astrophysics Data System (ADS)

Modeling complicated hydrologic systems often requires the integration of disparate data and models. The CUAHSI Hydrologic Information System targets the problem of integrating data by using a service-oriented architecture and data exchange standards to make heterogeneous databases appear to an end user as a single data resource. Similar integration problems exist with hydrologic models. If one wishes to analyze a problem that requires logic within multiple models, the challenge becomes how to couple those models so that they are able to exchange data during model runtime. A solution to this problem has been proposed through the Open Modeling Interface (OpenMI) standard for integrating hydrologic models. Building from the OpenMI standard, we have created a modeling environment within the CUAHSI Hydrologic Information System HydroDesktop application for performing integrated modeling. The modeling environment, which we have named HydroModeler, allows for loose coupling of model, analysis, and data components. We provide components for reading and writing data to the HydroDesktop database, as well as a number of example model configurations for demonstration and education purposes. An advantage of adopting the OpenMI standard is that it enables one to include OpenMI compliant models written by other groups within HydroModeler and, likewise, components written specifically for HydroModeler — e.g. the HydroDesktop database writer and reader components - can be used within other OpenMI-compliant modeling environments. Through the process of building HydroModeler we have investigated topics including (1) creating process-level OpenMI components, (2) modeling component configurations with bi-directional links (feedback loops), and (3) the process for re-scaling data exchanges between spatially and temporally misaligned data components “on-the-fly” during model configuration runs. These are general challenges faced by many modeling systems that adopt a loose coupling paradigm, and we will present how such issues can be addressed within HydroModeler using OpenMI. Our future plans are to continue to grow the number of model components within the environment, focusing specifically on decomposing large watershed models into functional components that can then be linked together to simulate hydrologic systems and address specific science or management questions.

Goodall, J. L.; Castronova, A. M.; Elag, M.; Ercan, M. B.

2010-12-01

125

A physically-based Distributed Hydrologic Model for Tropical Catchments  

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

126

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 ...

127

Application of environmental models to different hydrological systems  

Microsoft Academic Search

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

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

2000-01-01

128

Hydrologic Modeling in a Service-Oriented Architecture  

NASA Astrophysics Data System (ADS)

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.

Goodall, J. L.

2008-12-01

129

Neural Networks for Hydrological Modeling Tool for Operational Purposes  

NASA Astrophysics Data System (ADS)

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

Bhatt, Divya; Jain, Ashu

2010-05-01

130

A Catchment-Based Hydrologic and Routing Modeling System with explicit river channels  

Microsoft Academic Search

In this paper, we present a macroscale hydrologic modeling system with an explicit representation of storage and movement of water in river channels and floodplains. The overall modeling system, called the Catchment-Based Hydrologic and Routing Modeling System (CHARMS), is composed of a land surface model and a river routing model that operate on a network of hydrologic catchments (or watersheds).

Gopi Goteti; James S. Famiglietti; Kwabena Asante

2008-01-01

131

Physical Modeling of Hydrologic Processes in South Central Texas  

NASA Astrophysics Data System (ADS)

Flood magnitude and recurrence modeling and analysis play an important role in water resources planning, management, and permitting. In both urban and rural situations, flood analysis is important to flood plain mapping and the development of best management practices for both environmental and engineering concerns. The majority of annual precipitation in South Texas results from extreme, large storm events, which produce flash floods (the number one cause of weather-related deaths in Texas). Surface geology such as such as Edward out crop faulting zone at Balcones escarpment has different properties than the classified soil; affect the soil parameters such as infiltration or hydraulic conductivity. This result in a very high infiltration and channel loss as a recharge component to the Edward aquifer from the surface runoff and rivers that are crossing the recharge zone, such as Nueces, San Antonio, Guadalupe and Colorado Rivers. Water quality is another issue in hydrological modeling, specifically in south central Texas. Water quality assessment is another issue on hydrological modeling in south central Texas. SWAT Soil and water assessment tool model is used for water quality assessment in San Antonio River basin since the rainfall runoff simulation is a necessity to derive the surface water quality process especially in the streams. With the advances in the Geographical information system (GIS) and instant precipitation products such as next generation radar (NEXRAD) and data acquisition for these products, the accuracy of the hydrological models has improved. Different hydrological models were used to evaluate the surface water and other hydrological cycle components in different watersheds in south central Texas through different events and their different causes and effects in these watersheds. Some of them are semi distributed and lumped models such as Soil and Water Assessment Tool (SWAT), Hydrologic Modeling System (HEC-HMS) and physically based distributed model Girded Surface Subsurface Hydrologic Assessment GSSHA taking the advances of GIS, NEXRAD product, remote sensing and other product such as gridded land use and soil map to achieve the highest accuracy of these models.

El Hassan, A.; Sharif, H.; Xie, H.; Terrance, J.; Mcclelland, J.

2012-04-01

132

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

PubMed

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. PMID:15943376

Zhang, Shengtang; Kang, Shaozhong; Liu, Yin

2005-03-01

133

Hillslope Hydrologic Response: Integrating Field Observations And Mathematical Modeling  

NASA Astrophysics Data System (ADS)

The study is focused on the important and crucial feedback existing between hydrological modeling and field observations and the challenge for hydrologists to adapt model complexity to data availability across a huge variety of spatial and temporal scales. Continuous high-resolution hydrologic observations in a steep forested watershed in Northern California provide a quantitative description of the system behavior during water year 2008 (i.e. from October 2007 to September 2008). The development of a conceptual hydrologic model is presented and tested against the results from the application of well estabilished models (e.g. ParFlow, Gsflow, etc.). The framework adopted herein models the rock moisture dynamics (including the physical processes by which water from the overlying soils moves into and is redistributed by gravity and vegetation in the subsurface layer between the soil-bedrock interface and the water table) and the behavior of a shallow groundwater table observed in the field, and explicitly accounts for water use by vegetation as driven by atmospheric conditions and by water availability. This approach explores the mutual interactions between hydrological processes at the hillslope and the catchment scales, vegetation, atmospheric and geomorphologic processes and constitutes a first step towards the development of a mathematical tool able to predict droughts, floods and water supplies eventually under climate change scenarios at multiple spatial and temporal scales.

Uccelli, A.; Salve, R.; Dietrich, W. E.; Fung, I.

2008-12-01

134

A new global river network database for macroscale hydrologic modeling  

NASA Astrophysics Data System (ADS)

Coarse-resolution (upscaled) river networks are critical inputs for runoff routing in macroscale hydrologic models. Recently, Wu et al. (2011) developed a hierarchical dominant river tracing (DRT) algorithm for automated extraction and spatial upscaling of river networks using fine-scale hydrography inputs. We applied the DRT algorithms using combined HydroSHEDS and HYDRO1k global fine-scale hydrography inputs and produced a new series of upscaled global river network data at multiple (1/16° to 2°) spatial resolutions. The new upscaled results are internally consistent and congruent with the baseline fine-scale inputs and should facilitate improved regional to global scale hydrologic simulations.

Wu, Huan; Kimball, John S.; Li, Hongyi; Huang, Maoyi; Leung, L. Ruby; Adler, Robert F.

2012-09-01

135

Tall tales from the hydrological crypt: are models monsters?  

Microsoft Academic Search

“Bizarre,” “monstrous”: in society as well as in science, this is the way we are used to describing objects that deviate from an expected standard. Hydrology is no exception. The bizarre or the monstrous describes every object that has a low probability of occurring, or that our models fail to represent. Actually, the bizarre or the monstrous is often a

Thibault Mathevet; Remy Garçon

2010-01-01

136

Integrating wetlands and riparian zones in regional hydrological modeling  

Microsoft Academic Search

Wetlands, and in particular riparian wetlands, are at the interface between well drained land and the aquatic environment. They control the exchange of water and related chemical fluxes from catchment areas to surface waters like lakes and streams. Integrating wetlands and riparian zones in regional hydrological modeling is challenging because of the complex interactions between soil water, groundwater and surface

F. F. Hattermann; V. Krysanova; M. Wattenbach; F. Wechsung

2003-01-01

137

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...

138

EVALUATION OF HYDROLOGIC MODELS IN THE DESIGN OF STABLE LANDFILL COVERS  

EPA Science Inventory

The study evaluates the utility of two hydrologic models in designing stable landfill cover systems. The models evaluated were HELP (Hydrologic Evaluation of Landfill Performance) and CREAMS (Chemicals, Runoff, and Erosion from Agricultural Management Systems). Studies of paramet...

139

Test plan for hydrologic modeling of protective barriers  

SciTech Connect

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.

Fayer, M.J.

1990-03-01

140

Assessment of Digital Elevation Model (DEM) aggregation methods for hydrological modeling: Lake Chad basin, Africa  

Microsoft Academic Search

Digital Elevation Models (DEMs) are used to compute the hydro-geomorphological variables required by distributed hydrological models. However, the resolution of the most precise DEMs is too fine to run these models over regional watersheds. DEMs therefore need to be aggregated to coarser resolutions, affecting both the representation of the land surface and the hydrological simulations. In the present paper, six

Mathieu Le Coz; François Delclaux; Pierre Genthon; Guillaume Favreau

2009-01-01

141

Improving the hydrology of the Simple Biosphere Model 2 and its evaluation within the framework of a distributed hydrological model  

Microsoft Academic Search

The hydrological description of the Simple Biosphere Model 2 (SiB2) is improved in three respects. First, the SiB2 three-layer soil model is replaced with a multi-layer soil column coupled to a lumped unconfined aquifer model. Next, lateral water flows are described in the updated soil model. Finally, the soil hydraulic function in SiB2 is replaced with van Genuchten parameterization, and

LEI WANG; TOSHIO KOIKE; DAWEN YANG; KUN YANG

2009-01-01

142

Data Fusion Methods for Integrating Data-driven Hydrological Models  

Microsoft Academic Search

This chapter will address the use of different data fusion techniques for integrating or combining hydrological models. Different\\u000a approaches will be demonstrated using flow forecasting models from the River Ouse catchment in the UK for a lead time of 6\\u000a hours. These approaches include simple averaging, neural networks, fuzzy logic, M5 model trees and instance-based learning.\\u000a The results show that

Linda M. See

2008-01-01

143

Identification of possible structural error in hydrological models  

NASA Astrophysics Data System (ADS)

Hydrological Models are simplifications and theoretical approximations of complex natural phenomena. Hence, they cannot predict perfectly what happen in natural systems. There are several reasons; some of the main reasons are error in the input data, imperfect model structure, insufficient information for parameter identification etc. The identification of structural error in a complex model is very difficult task. This is especially difficult as the final differences between observation and model results are a combined consequence of the above reasons. In this study we aimed to develop a tool to identify possible model structural error in hydrological model by using the concept of the data depth function. The model was calibrated using the ROPE (Bárdossy and Singh 2008) algorithm and the optimal parameter space was obtained. From N optimal parameter sets N discharge series were obtained and boundary of the convex hull from d-dimensional dataset corresponding N discharge series (DB) is taken for further analysis. A d-dimensional dataset corresponding to the observed discharge (DX) is taken and depth of the each elements of observed discharge is calculated with respect to the boundary of the convex hull from N model discharge series. If there are elements in DX whose depths are zero with respect to the convex hull (DB), then those corresponding to d-days trajectories of the observation for which there is no similarity in any of the model parameterization. These elements can give possible indication for model structure errors. The methodology was demonstrated on two models HYMOD and TopNet in Pelorous catchment of New Zealand. Bárdossy, A. and S. K. Singh (2008). "Robust estimation of hydrological model parameters." Hydrology and Earth System Sciences 12: 1273-1283.

Singh, S. K.; Bárdossy, A.; McMillan, H.

2012-04-01

144

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

PubMed

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. PMID:15238667

Raskob, W; Heling, R; Zheleznyak, M

2004-01-01

145

Modeling winter hydrological processes under differing climatic conditions: Modifying WEPP  

NASA Astrophysics Data System (ADS)

Water erosion is a serious and continuous environmental problem worldwide. In cold regions, soil freeze and thaw has great impacts on infiltration and erosion. Rain or snowmelt on a thawing soil can cause severe water erosion. Of equal importance is snow accumulation and snowmelt, which can be the predominant hydrological process in areas of mid- to high latitudes and forested watersheds. Modelers must properly simulate winter processes to adequately represent the overall hydrological outcome and sediment and chemical transport in these areas. Modeling winter hydrology is presently lacking in water erosion models. Most of these models are based on the functional Universal Soil Loss Equation (USLE) or its revised forms, e.g., Revised USLE (RUSLE). In RUSLE a seasonally variable soil erodibility factor (K) was used to account for the effects of frozen and thawing soil. Yet the use of this factor requires observation data for calibration, and such a simplified approach cannot represent the complicated transient freeze-thaw processes and their impacts on surface runoff and erosion. The Water Erosion Prediction Project (WEPP) watershed model, a physically-based erosion prediction software developed by the USDA-ARS, has seen numerous applications within and outside the US. WEPP simulates winter processes, including snow accumulation, snowmelt, and soil freeze-thaw, using an approach based on mass and energy conservation. However, previous studies showed the inadequacy of the winter routines in the WEPP model. Therefore, the objectives of this study were: (1) To adapt a modeling approach for winter hydrology based on mass and energy conservation, and to implement this approach into a physically-oriented hydrological model, such as WEPP; and (2) To assess this modeling approach through case applications to different geographic conditions. A new winter routine was developed and its performance was evaluated by incorporating it into WEPP (v2008.9) and then applying WEPP to four study sites at different spatial scales under different climatic conditions, including experimental plots in Pullman, WA and Morris, MN, two agricultural drainages in Pendleton, OR, and a forest watershed in Mica Creek, ID. The model applications showed promising results, indicating adequacy of the mass- and energy-balance-based approach for winter hydrology simulation.

Dun, Shuhui

146

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

Microsoft Academic Search

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

Natalia Kotova; Olga Semenova

2010-01-01

147

Initial results from a distributed, physically based model of glacier hydrology  

Microsoft Academic Search

This paper describes the development and testing of a distributed, physically based model of glacier hydrology. The model is used to investigate the behaviour of the hydrological system of Haut Glacier d'Arolla, Valais, Switzerland. The model has an hourly time-step and three main components: a surface energy balance submodel, a surface flow routing submodel and a subglacial hydrology submodel. The

Neil Arnold; Keith Richards; Ian Willis; Martin Sharp

1998-01-01

148

On Common Morphological Features From Global Hydrology Models and GRACE and Their Application in Global Hydrological Modeling  

NASA Astrophysics Data System (ADS)

As one part of the exploitation of GRACE-based surface mass anomalies in geoscientific applications appropriate filter techniques are needed, e.g., in order to suppress spurious gravity signals in the GRACE solutions and/or to compute region-specific functionals. A second general aspect concerns the signal separation of the integral gravity gravity measurements taken by the satellites, i.e., the detection of individual contributions of gravity change (in space and time; also quantitatively) which are in turn the input for quantitative modelling of the specific process of interest (e.g. hydrology, oceanography, isostatic adjustment, etc.). To achieve this, characterizations of the morphology of the individual processes are needed, which are then to be traced in the GRACE data. In this contribution the focus is laid on hydrology. In the first part we present results of such characterizations of continental water storage change inferred from three different state-of-the-art global hydrology models and common features in recent time series of monthly GRACE-only gravity models. These studies are based on the usage of spectral correlation analysis and Empirical Orthogonal Functions (EOF). The investigations were performed both in spectral and space domains, globally as well as on the basis of individual catchment areas. In the second part we present preliminary study results on how to constrain large-scale hydrological models additionally using GRACE-based surface mass anomalies. Towards such a calibration, a sensitivity analysis was performed for the WaterGap Global Hydrology Model (WGHM), to identify sensitive parameters for simulated water storage changes. The feasibility to adjust the model to GRACE observations was then examined by a single-criteria calibration against seasonal storage changes from GRACE for selected river basins. Results are also evaluated with respect to the morphological features mentioned above and observed river discharge data. The results give insight into the potential of multi-criterial calibration of WGHM for both storage change and discharge.

Schmidt, R.; Petrovic, S.; Werth, S.; Güntner, A.; Wünsch, J.; Barthelmes, F.; Rothacher, M.

2006-12-01

149

Hydrological modelling in poorly gauged catchments using a constraints  

NASA Astrophysics Data System (ADS)

In catchments with available discharge data hydrological model parameters are estimated using some kind of optimization or sampling procedure. For ungauged catchments parameters can only be identified using hydrological knowledge and available meteorological and geographical information. These however can constrain the model parameters if the uncertainty of the available information is quantified. This contribution shows how the set of model parameters of a given model can be built from constraints and related uncertainty. Multivariate data analysis techniques including different data depth concepts can are used for this purpose. The value of information included is expressed with the volume of the corresponding parameter set. The methodology is demonstrated on selected catchments in SW-Germany where observations allow the validation of the approach.

Bardossy, A.; Singh, S.

2009-12-01

150

The Benefit of Polarimetric Radar in Hydrologic Modeling  

NASA Astrophysics Data System (ADS)

Beginning in 2010, the entire WSR-88D radar network will be upgraded with dual-polarization capability. Polarimetric radar has shown benefits in removing artifacts from rainfall rate products due to non- meteorological scatterers, identifying hydrometeor phases, habits, and types, and improving estimates of heavy rainfall especially when mixed with hail. Previous hydrologic studies have included polarimetric rainfall estimates, but typically have focused on a single event using a particular hydrologic model. The intention of this study is to evaluate the general hydrologic performance of several rainfall algorithms which are based on variables collected by the polarimetric prototype of the WSR-88D, KOUN. We have concentrated our study on the heavily instrumented Ft. Cobb basin in Oklahoma for several events occurring over a three-year period, including an extreme event from a tropical storm that had a return period greater than 100 years. The Ft. Cobb basin is 813 km2 in area and includes the USDA's Agricultural Research Service's Micronet, a network of 15 stations that measure air temperature, rainfall, relative humidity, solar radiation, soil temperature at four depths, and soil water content at three depths. The high- density rain gauge network is used to evaluate the remote-sensing rainfall algorithms. In addition, we have set up and calibrated three different hydrologic models that have various levels of complexity ranging from purely empirical to distributed parameter, physically-based structures. This study will quantify the skill of the various hydrologic model simulations conditioned on the polarimetric rainfall inputs being investigated. Benchmark simulations are produced from rainfall algorithms using the standard WSR-88D reflectivity-to- rainfall (Z-R) relation as well as a rain gauge-only product, all of which are compared to observed streamflow at three USGS stations.

Gourley, J. J.; Giangrande, S.; Schuur, T.; Hong, Y.; Flamig, Z.

2008-12-01

151

DEM-based spatial discretization and parameter database design for distributed hydrological model  

NASA Astrophysics Data System (ADS)

The spatial heterogeneities of hydrological parameters in watersheds with limited extents should be accounted by the distributed hydrological model. Dongting Lake is selected as the study area and divided into 19759 hydrological response units based on DEM according to the concept of drainage density. Each unit has one land-use type and one soil type. The hydrological response units are utilized as the minimum units in simulations of hydrological processes and a parameter database of the distributed hydrological model is designed under the support of GIS. The parameters are managed with layers in the database. The structure of the database is helpful for organizing and updating the parameters.

Zhang, Xu; Zhou, Tinggang; Zheng, Jianrui

2009-10-01

152

Modelling hydrological responses of Nerbioi River Basin to Climate Change  

NASA Astrophysics Data System (ADS)

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 basin (Basque Country, North of Spain). So that adaptation strategies can be defined. In order to fulfil this objective four subobjectives are defined: (1)selection of the future climate projections for the case study area from a wide spectrum of possibilities; (2) model the hydrological processes of the basin with a physically distributed complex hydrological model; (3) validation of the hydrological model with observation data; and (4) runoff simulation introducing regional climate model data selected. The analysis of climate models suggests that extreme precipitation in the Basque Country increased by about 10% during the twenty-first century. This increase of extreme precipitations raised discharge and water level in Nerbioi river basin. That is why in the 21st century it is expected that the flood-prone area will expand for precipitation with a return period of 50 years. In this context, it is necessary to define and evaluate different adaptation options which are already in practice or conceivable according to the current scientific knowledge. As well as evaluate the adaptation measures in terms of their ability to lower the vulnerability of water resources to climate change. For example, land use change could be a useful tool to adapt our basin systems. The land use plays an important role on the water balance of a river by varying the proportion of precipitation that runs off and the fraction that is lost by evapotranspiration. Therefore, both climate change and adaptation strategies will have an impact on the hydrodynamic conditions of rivers; particularly the changes in flow conditions will have a severe ecological, economical and social impact. As future work, adaptation measures will introduce in the future runoff simulation in order to evaluate the effectiveness and as a decision-making tool to operational organisations.

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

2010-05-01

153

Performance comparison of hydrological model structures during low flows  

NASA Astrophysics Data System (ADS)

Low flows are still poorly reproduced by common hydrological models since they are traditionally designed to meet peak flow situations best possible. As low flow becomes increasingly important to several target areas there is a need to improve available models. We present a study that assesses the impact of model structure on low flow simulations. This is done using the Framework for Understanding Structural Errors (FUSE), which identifies the set of (subjective) decisions made when building a hydrological model, and provides multiple options for each modeling decision. 79 models were built using the FUSE framework, and applied to simulate stream flows in the Narsjø catchment in Norway (119 km²). To allow comparison all new models were calibrated using an automatic optimization method. Low flow and recession analysis of the new models enables us to evaluate model performance focusing on different aspects by using various objective functions. Additionally, model structures responsible for poor performance, and hence unsuitable, can be detected. We focused on elucidating model performance during summer (August - October) and winter low flows which evolve from entirely different hydrological processes in the Narsjø catchment. Summer low flows develop out of a lack of precipitation while winter low flows are due to water storage in ice and snow. The results showed that simulations of summer low flows were throughout poorer than simulations of winter low flows when evaluating with an objective function focusing on low flows; here, the model structure influencing winter low flow simulations is the lower layer architecture. Different model structures were found to influence model performance during the summer season. The choice of other objective functions has the potential to affect such an evaluation. These findings call for the use of different model structures tailored to particular needs.

Staudinger, Maria; Stahl, Kerstin; Tallaksen, Lena M.; Clark, Martyn P.; Seibert, Jan

2010-05-01

154

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 ...

155

Modeling the hydrologic effects of roadside ditch networks on receiving waters  

NASA Astrophysics Data System (ADS)

We modeled the hydrologic effects of artificial drainages. Road ditches increased drainage density and decreased flow distance to streams. Such networks also increased peak discharge and total event flow. Implications for basin hydrology and contaminant transport are discussed.

Buchanan, Brian; Easton, Zachary M.; Schneider, Rebecca L.; Walter, M. Todd

2013-04-01

156

On the spatio-temporal analysis of hydrological droughts from global hydrological models  

NASA Astrophysics Data System (ADS)

The recent concerns for world-wide extreme events related to climate change have motivated the development of large scale models that simulate the global water cycle. In this context, analysis of hydrological extremes is important and requires the adaptation of identification methods used for river basin models. This paper presents two methodologies that extend the tools to analyze spatio-temporal drought development and characteristics using large scale gridded time series of hydrometeorological data. The methodologies are classified as non-contiguous and contiguous drought area analyses (i.e. NCDA and CDA). The NCDA presents time series of percentages of areas in drought at the global scale and for pre-defined regions of known hydroclimatology. The CDA is introduced as a complementary method that generates information on the spatial coherence of drought events at the global scale. Spatial drought events are found through CDA by clustering patterns (contiguous areas). In this study the global hydrological model WaterGAP was used to illustrate the methodology development. Global gridded time series of subsurface runoff (resolution 0.5°) simulated with the WaterGAP model from land points were used. The NCDA and CDA were developed to identify drought events in runoff. The percentages of area in drought calculated with both methods show complementary information on the spatial and temporal events for the last decades of the 20th century. The NCDA provides relevant information on the average number of droughts, duration and severity (deficit volume) for pre-defined regions (globe, 2 selected hydroclimatic regions). Additionally, the CDA provides information on the number of spatially linked areas in drought, maximum spatial event and their geographic location on the globe. Some results capture the overall spatio-temporal drought extremes over the last decades of the 20th century. Events like the El Niño Southern Oscillation (ENSO) in South America and the pan-European drought in 1976 appeared clearly in both analyses. The methodologies introduced provide an important basis for the global characterization of droughts, model inter-comparison of drought identified from global hydrological models and spatial event analyses.

Corzo Perez, G. A.; van Huijgevoort, M. H. J.; Voß, F.; van Lanen, H. A. J.

2011-09-01

157

Toward a Systematic Framework for Model Evaluation in Catchment Hydrology  

NASA Astrophysics Data System (ADS)

In recent years, a strong debate has emerged in the hydrologic literature regarding what constitutes an appropriate framework for model evaluation and uncertainty estimation. Particularly, there is strong disagreement whether an uncertainty framework should have its roots within a proper statistical (Bayesian) context, or whether such a framework should be based on a different philosophy and implement informal measures and weaker inference to summarize parameter and predictive distributions. Here, I compare a formal Bayesian approach using Markov Chain Monte Carlo (MCMC) sampling with Generalized Likelihood Uncertainty Estimation (GLUE) for assessing uncertainty in conceptual watershed modeling. Our formal Bayesian approach is implemented using the recently developed DiffeRential Evolution Adaptive Metropolis (DREAM) MCMC scheme with a likelihood function that explicitly considers model structural, input and parameter uncertainty. Our results demonstrate that DREAM and GLUE can generate very similar estimates of total streamflow uncertainty. This suggests that formal and informal Bayesian approaches have more common ground than the hydrologic literature and ongoing debate might suggest. The main advantage of formal approaches is, however, that they attempt to disentangle the effect of forcing, parameter and model structural error on total predictive uncertainty. This is key to improving hydrologic theory and to better understand and predict the flow of water through catchments.

Vrugt, J. A.

2009-04-01

158

Selection of Hydrological Model for Waterborne Release  

SciTech Connect

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 DB and BDB accidents to be used in the future study.

Blanchard, A.

1999-02-03

159

RECURSIVE PARAMETER ESTIMATION OF HYDROLOGIC MODELS  

EPA Science Inventory

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

160

A rangeland hydrology and erosion model  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

161

Ensemble stream flow predictions, a way towards better hydrological forecasting  

NASA Astrophysics Data System (ADS)

The hydrological forecasting division at SMHI has been using hydrological EPS and hydrological probabilities forecasts operationally since some years ago. The inputs to the hydrological model HBV are the EPS forecasts from ECMWF. From the ensemble, non-exceedance probabilities are estimated and final correction of the ensemble spread, based on evaluation is done. Ensemble stream flow predictions are done for about 80 indicator basins in Sweden, where there is a real-time discharge gauge. The EPS runs are updated daily against the latest observed discharge. Flood probability maps for exceeding a certain threshold, i.e. a certain warning level, are produced automatically once a day. The flood probabilistic forecasts are based on a HBV- model application, (called HBV-Sv, HBV Sweden) that covers the whole country and consist of 1001 subbasins with an average size between 200 and 700 km2. Probabilities computations for exceeding a certain warning level are made for each one of these 1001 subbasins. Statistical flood levels have been calculated for each river sub-basin. Hydrological probability forecasts should be seen as an early warning product that can give better support in decision making to end-users communities, for instance Civil Protections Offices and County Administrative Boards, within flood risk management. The main limitations with probability forecasts are: on one hand, difficulties to catch small-scale rain (mainly due to resolution of meteorological models); on the other hand, the hydrological model can't be updated against observations in all subbasins. The benefits of working with probabilities consist, first of all, of a new approach when working with flood risk management and scenarios. A probability forecast can give an early indication for Civil Protection that "something is going to happen" and to gain time in preparing aid operations. The ensemble stream flow prediction at SMHI is integrated with the national forecasting system and the products are available to specialized end-users via Internet.

Edlund, C.

2009-04-01

162

DEVELOPING A TEXTURE-BASED SOIL HYDROLOGIC CHARACTERISTICS MODEL AND EXTENDING THIS MODEL TO PREDICT SOIL STRENGTH CHARACTERISTICS  

Microsoft Academic Search

Hydrologic models are used to describe water flow patterns in the soil, but there are not many models to describe the influence of soil water on soil mechanical properties. The purpose of this study was to adapt a hydrologic model to predict soil strength. In order to accomplish this goal, a new soil hydrologic characteristics model was developed using new

R. Pulley; M. Min; J. Chaplin

163

A Dissipative Hydrological Model for the Hotan Oasis (DHMHO)  

Microsoft Academic Search

Various hydrological models have been designed to simulate moisture transformation in the water-cycle system between atmospheric\\u000a water, surface water, soil water and groundwater. But few have been designed specially for oases in arid desert areas where\\u000a the ecology and the environment are vulnerable because of unwise water-land resources utilization. In order to analyze the\\u000a moisture transformation in the Hotan Oasis

Changsen Zhao; Bing Shen; Lingmei Huang; Zhidong Lei; Heping Hu; Shixiu Yang

2009-01-01

164

Hydrologic modeling of soil water storage in landfill cover systems  

SciTech Connect

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.

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

1987-01-01

165

What is the minimal geomorphology based hydrological model?  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

166

Modeling Soil Moisture Fields Using the Distributed Hydrologic Model MOBIDIC  

NASA Astrophysics Data System (ADS)

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. Mazzanti (2009), A distributed package for sustainable water management: a case study in the Arno basin, IAHS Publ. 327 Flerchinger, G. N. (2000), The Simultaneous Heat and Water (SHAW) Model: Technical Documentation, Technical Report NWRC 2000-09, USDA Agricultural Research Service, Boise, Idaho

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

2011-12-01

167

Selection of Hydrological Model for Waterborne Release  

SciTech Connect

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.

Blanchard, A.

1999-04-21

168

Assessing climate change impact by integrated hydrological modelling  

NASA Astrophysics Data System (ADS)

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

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

169

Intercomparison of hydrologic processes in global climate models  

NASA Astrophysics Data System (ADS)

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.

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

1995-05-01

170

Integrated hydrological SVAT model for climate change studies in Denmark  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

171

Calibration of hydrologic models using flow-duration curves  

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

172

Parallelization of a hydrological model using the message passing interface  

USGS Publications Warehouse

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.

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

2013-01-01

173

Scale and Resolution Relationships of Soils Information with Hydrology Modeling  

NASA Astrophysics Data System (ADS)

Recent developments in digital soil mapping coupled with pedotransfer functions have improved significantly the ability of soil information to be provided quantitatively. This presents a challenge and an opportunity to understand the scale dependency of simulated hydrologic processes and their relation to the scale and spatial resolution of soil information. The objective of this research is to determine the sensitivity of hydrologic model simulations to the underlying spatial resolution of soils information in the context of different watersheds sizes. Hall Creek, a 56 km2 watershed in southern Indiana was the focus of this study. The majority of the soils in the watershed formed in loess over weathered sandstone, siltstone and shale. Sub-watersheds varying in size from less than 1km2 to 25km2 were delineated based on 5 m resolution DEM. Raster based soil maps at 5m resolution were first created using Terrain Attribute Soil Mapping (TASM) procedures. The soil maps were then used as an input to the Distributed Hydrology Vegetation Model (DHSVM) to predict stream flow from various sub-watersheds. In order to study the interaction between the aggregation level of soil information and watershed size, the pixel size for the DHSVM simulation was kept at 5m while the pixel size of the underlying soil maps was changed to 5, 10, 30 and 90m resolution. The DHSVM was calibrated for the Hall Creek watershed based on the 5m soil information and the USGS recorded stream discharge. The differences between predicted stream flows increased with decreasing resolution level of the soil information. The differences increased progressively as the sub-watersheds size decreased suggesting an interaction between watershed size and aggregation level of soil information. The magnitude of the predicted streamflow sensitivity can be used to determine the appropriate spatial resolution for digital soil mapping for hydrology applications, in relation to watershed size.

Libohova, Z.; Owens, P.; Bowling, L. C.; Cherkauer, K. A.; Naz, B. S.; Winzeler, E. H.

2009-12-01

174

Improved understanding and prediction of the hydrologic response of highly urbanized catchments through development of the Illinois Urban Hydrologic Model  

NASA Astrophysics Data System (ADS)

What happens to the rain in highly urbanized catchments? That is the question that urban hydrologists must ask themselves when trying to integrate the hydrologic and hydraulic processes that affect the hydrologic response of urban catchments. The Illinois Urban Hydrologic Model (IUHM) has been developed to help answer this question and improve understanding and prediction of hydrologic response in highly urbanized catchments. Urban catchments are significantly different than natural watersheds, but there are similarities that allow features of the pioneering geomorphologic instantaneous unit hydrograph concept developed for natural watersheds to be adapted to the urban setting. This probabilistically based approach is a marked departure from the traditional deterministic models used to design and simulate urban sewer systems and does not have the burdensome input data requirements that detailed deterministic models possess. Application of IUHM to the CDS-51 catchment located in the village of Dolton, Illinois, highlights the model's ability to predict the hydrologic response of the catchment as well as the widely accepted SWMM model and is in accordance with observed data recorded by the United States Geological Survey. In addition, the unique structure and organization of urban sewer networks make it possible to characterize a set of ratios for urban catchments that allow IUHM to be applied when detailed input data are not available.

Cantone, Joshua; Schmidt, Arthur

2011-08-01

175

Inactivated Orf Virus Shows Antifibrotic Activity and Inhibits Human Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) Replication in Preclinical Models  

PubMed Central

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.

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

176

Modeling Hydrologic and Vegetation Responses in Freshwater Wetlands  

NASA Astrophysics Data System (ADS)

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-site, indicating the potential of the model in capturing soil moisture dynamics. Further application of the model for impact assessments demonstrates that drainage of wetlands resulting in groundwater drawdown is expected to produce appreciable effects on vegetation biomass response. The model developed in this study simulates the coupled and spatially-varying groundwater movement and plant growth dynamics, which allows researchers to better understand and protect the integrated hydrologic and vegetation systems of wetlands worldwide.

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

2010-05-01

177

Multiscale and Multicriterial Hydrological Validation of the Eco-hydrological Model SWIM  

Microsoft Academic Search

The hydrological validation described in this paper follows a bottom-up approach, when at first 12 mesoscale subbasins, covering the main subregions of the basin, are validated, and then the information gained from the mesoscale is used to validate the hydrological processes of the whole basin. Special attention was paid to the use of spatial information (maps of water table depth)

F. Hattermann; V. Krysanova; F. Wechsung; M. Wattenbach

178

Hydrological trend analysis in the Yellow River basin using a distributed hydrological model  

Microsoft Academic Search

The hydrological cycle has been highly influenced by climate change and human activities, and it is significant for analyzing the hydrological trends that occurred in past decades in order to understand past changes and to predict future trends. The water crisis of the Yellow River basin has drawn much attention from around the world, especially the drying up of the

Zhentao Cong; Dawen Yang; Bing Gao; Hanbo Yang; Heping Hu

2009-01-01

179

Hydrologic effects of fire in sagebrush plant communities: Implications for rangeland hydrology and erosion modeling  

Technology Transfer Automated Retrieval System (TEKTRAN)

Millions of dollars are spent annually in the United States mitigating fire effects on rangeland hydrology and erosion. Rangeland managers and scientists need predictive tools to simulate hydrologic processes dictating post-fire responses, assist mitigation and risk assessments, and predict post-fir...

180

Climate change impact on available water resources obtained using multiple global climate and hydrology models  

NASA Astrophysics Data System (ADS)

Climate change is expected to alter the hydrological cycle resulting in large-scale impacts on water availability. However, future climate change impact assessments are highly uncertain. For the first time, multiple global climate (three) and hydrological models (eight) were used to systematically assess the hydrological response to climate change and project the future state of global water resources. This multi-model ensemble allows us to investigate how the hydrology models contribute to the uncertainty in projected hydrological changes compared to the climate models. Due to their systematic biases, GCM outputs cannot be used directly in hydrological impact studies, so a statistical bias correction has been applied. The results show a large spread in projected changes in water resources within the climate-hydrology modelling chain for some regions. They clearly demonstrate that climate models are not the only source of uncertainty for hydrological change, and that the spread resulting from the choice of the hydrology model is larger than the spread originating from the climate models over many areas. But there are also areas showing a robust change signal, such as at high latitudes and in some midlatitude regions, where the models agree on the sign of projected hydrological changes, indicative of higher confidence in this ensemble mean signal. In many catchments an increase of available water resources is expected but there are some severe decreases in Central and Southern Europe, the Middle East, the Mississippi River basin, southern Africa, southern China and south-eastern Australia.

Hagemann, S.; Chen, C.; Clark, D. B.; Folwell, S.; Gosling, S. N.; Haddeland, I.; Hanasaki, N.; Heinke, J.; Ludwig, F.; Voss, F.; Wiltshire, A. J.

2013-05-01

181

Sensitivity testing of a coupled Escherichia coli Hydrologic catchment model  

NASA Astrophysics Data System (ADS)

A conceptual model of microbial behaviour in catchments coupled with a standard hydrological model, known as the EG model, has been previously developed and tested for Escherichia coli. Due to the unavailability of pathogen data, E. coli has been used as a pathogen indicator. However, the model uses a broad conceptual approach and therefore should be tested for other microbes in future. This paper presents work done on sensitivity of the EG model, as well as its further refinement. Sensitivity of the model results to all E. coli calibration parameters was carried out. The EG model was then tested for its sensitivity to the number of events used to calibrate the model. The data collected at three different Australian drinking water catchments were used. Of the four parameters in the E. coli component of the EG model, two proved to be insensitive while the other two proved to be important. The sensitive parameters were the coefficients associated with the ‘wash-off’ functions in the model, while the two insensitive coefficients were associated with the E. coli decay functions in the model. However, the model became more sensitive towards the decay parameters in cleaner catchments. This indicates that the hydrologic aspects of the E. coli transport processes dominate rather than the E. coli decay functions. Apart from one catchment (that was partly urbanised and much smaller than the other two), the model was successfully calibrated using a small number of monitored events. It was concluded that the EG model could be simplified further by not modelling the decay of the pathogen indicator, E. coli.

Haydon, S.; Deletic, A.

2007-05-01

182

Point evaluation of a surface hydrology model for BOREAS  

NASA Astrophysics Data System (ADS)

Detailed observations of moisture and energy fluxes made at the Boreal Ecosystem-Atmosphere Study (BOREAS) tower flux sites offer a unique opportunity for the evaluation of hydrological models, since model process representations can be compared with observations. The distributed hydrology-soil-vegetation model (DHSVM) was used to simulate the latent and sensible heat fluxes at the old black spruce and old jack pine tower flux sites in the southern study area and the old black spruce tower in the northern study area during the summer of 1994. The model did a reasonable job of simulating both the seasonal average fluxes and the diurnal cycle of the surface heat fluxes. However, a lag was observed in the simulation of the sensible heat flux, which was attributed to an inadequate representation of the ground heat flux and ground heat storage. It was also noted that direct soil evaporation forms an important part of the latent heat flux simulated by the model. Incorporation of a more complete soil thermal model, and further field work in 1996 to evaluate the importance of the moss layer and the direct evaporation from the soil, is expected to lead to further improvements.

Nijssen, Bart; Haddeland, Ingjerd; Lettenmaier, Dennis P.

1997-12-01

183

Spatial organisation in hydrological model structure for New Zealand catchments  

NASA Astrophysics Data System (ADS)

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

McMillan, Hilary; Woods, Ross; Clark, Martyn

2013-04-01

184

Semidistributed hydrologic modeling using remotely sensed data and GIS  

NASA Astrophysics Data System (ADS)

A semi-distributed, physically based hydrologic model (called DPHM-RS) is designed to take advantage of distributed hydrologic information retrieved from various space platform and topographic information processed from Digital Terrain Elevation Data (DTED). DPHM-RS was applied to the Paddle River Basin of central Alberta which was characterized by 5 sub-basins with each sub-basin having its own land cover types and terrain features. Input data to the model included meteorological data collected from 2 meteorological towers set up at the study site, field soil moisture data, topographic information derived from DTED, and distributed hydrologic information retrieved from NOAA-AVHRR, Landsat-TM, and Radarsat SAR data. DPHM-RS was calibrated with the data of summer, 1996 and validated with data of summer, 1997 and 1998. Excellent agreements between simulated and observed runoff at the basin outlet, energy fluxes and surface temperature demonstrated that DPHM-RS is capable of modeling basin-scale hydrologic processes. This is further confirmed by logical differences in the actual evapotranspiration (ET) simulated for different land covers and by sensible temporal variations of soil moisture simulated for each sub-basin. Given that in many aspects the performance of DPHM-RS is creditable, the ET component is used, the two-source model, to assess two popular ET models, the Penman-Menteith equation and the modified Penman equation of Granger and Gray (1989) for non-saturated surface. Based on the ET simulated for several land use classes, it seems that the closed canopy assumption of Penman-Menteith is applicable to coniferous forest and agricultural lands but not to mixed forest and pasturelands of the Canadian Prairies. The modified Penman model is generally applicable under dry environment but could estimate ET that is biased under cloudy, rainy days and wet environment. From 6 scenes of Radarsat SAR images acquired for the Paddle River Basin, and 1350 soil moisture samples collected in the same days from 9 selected sites of the Basin, we demonstrated the feasibility of retrieving near-surface soil moisture from Radarsat SAR images using a linear regression and the theoretical integration equation model (IEM) of Fung et al. (1992). From these data, we also found that for a single land use, the relationship between the cross-correlation of soil moisture and inter-site distance breaks down at a distance of about 250 m.

Biftu, Getu Fana

185

Flood modelling in complex hydrologic systems with sparsely resolved data  

NASA Astrophysics Data System (ADS)

The European Directive on Assessment and Management of Flood Risks places significant emphasis on establishing tools suitable for simulating the relevant hydrologic processes in areas of high flood risk. Because flood modelling requires relatively detailed spatial and temporal resolutions, the model selection is controlled by the available distributed hydrologic information. The value of data (mainly stage/discharge records) is indisputable, since the quality of calibration and, consequently, the model predictive capacity, depends on the availability of reliable observations at multiple sites. On the other hand, data scarcity is a global problem in hydrologic engineering that is getting increasingly severe as the monitoring infrastructure is shrinking and degraded. It is therefore crucial to build reliable models that are parsimonious. In this vein, we have adapted the HYDROGEIOS model (Efstratiadis et al., 2008), initially developed as a conjunctive surface-groundwater simulation and water management tool at the monthly time scale, to run in daily time steps. In typical flood simulation packages inputs are time series of precipitation, which are resolved in hourly or finer increment, and detailed hydro-morphologic properties of the stream network. In contrast, the enhanced version of HYDROGEIOS only uses daily rainfall depths and a limited number of parameters that are estimated or calibrated on the basis of once-a-day discharge data. The character of HYDROGEIOS as a conjunctive model enables to represent simultaneously the interactions among the surface and sub-surface processes and the human interventions, and to route the runoff across the stream network. Lacking finely resolved precipitation data and for the purpose of flood routing, we have applied a disaggregation technique to analyse the simulated daily hydrographs in finer time steps. Flood routing is implemented via either a kinematic-wave or a Muskingum diffusive-wave scheme, introducing only one or two parameters per stream reach, respectively. The new version of HYDROGEIOS is being tested on the Boeotikos Kephisos River Basin for flood forecasting in real-time, using as input precipitation forecasts from numerical weather prediction simulations (European project FLASH). The basin is heavily modified, with strong physical heterogeneities, involving multiple peculiarities such as significant karst springs, which rapidly contribute to the streamflow, thus reflecting a strong interaction between surface and ground water processes, and a drainage canal and network in the lower basin with extremely small slopes. Reference Efstratiadis, A., I. Nalbantis, A. Koukouvinos, E. Rozos, and D. Koutsoyiannis, HYDROGEIOS: a semi-distributed GIS-based hydrological model for modified river basins, Hydrol. Earth Syst. Sci., 12, 989-1006, 2008.

Efstratiadis, A.; Mazi, K.; Koussis, A. D.; Koutsoyiannis, D.

2009-04-01

186

From hydrodynamic to hydrological modelling: Investigating long-term hydrological regimes of key wetlands in the Macquarie Marshes, a semi-arid lowland floodplain in Australia  

NASA Astrophysics Data System (ADS)

We developed a large-scale fine-resolution 1D/2D floodplain hydrodynamic model.We built a river system model with main wetlands using data from hydraulic model.The approach provides a practical method to model wetland hydrological regimes.We investigated the impacts of river management on wetland hydrological regimes.The hydrological model has multiple applications for research and management.

Wen, Li; Macdonald, Rohan; Morrison, Tim; Hameed, Tahir; Saintilan, Neil; Ling, Joanne

2013-09-01

187

A flexible modeling package for topographically based watershed hydrology  

NASA Astrophysics Data System (ADS)

An OBJect-oriented TOPographic-based (OBJTOP) hydrological model with a graphical user interface (GUI) was created using object-oriented design (OOD) methods and the objected-oriented programming (OOP) language-C++. OBJTOP presents an array of alternative TOPMODEL hydrological processes of (1) saturation excess or the mixture of infiltration/saturation excess overland flow, (2) exponential or power law decay of hydraulic conductivity with soil depth, (3) topographic index (TI) or soil topographic index (STI) weighting of run-off likelihood, and (4) simulations with or without channel routing, to explain watershed response and increase flexibility and applicability. OBJTOP utilized an object-oriented design (OOD) approach, including the ‘inheritance’ concept to study individual objects (or processes) at multiple levels, and the ‘aggregation’ concept to study the interactions of objects (or processes). Further, OOD readily provides for model extension, creating a description of hydrologic processes in a natural, direct, concise, and adaptable manner distinct from procedurally designed and implemented models. The OBJTOP GUI provides an efficient tool for data input, parameter modification, simulation scheme selection and model calibration with three objective functions, including Nash-Sutcliffe. Graphical outputs include time series plots of precipitation depth, partitioned run-off volumes, watertable depth (average or TI/STI based), and map graphics of TI, STI, and depth to watertable. Applications illustrating OBJTOP ability and flexibility include simulation of the TOPMODEL standard Slapton Wood, UK dataset, and simulation of Ward Pound Ridge, NY a small forested catchment with power function decay of hydraulic conductivity and extensive impervious surfaces.

Wang, Jun; Endreny, Theodore A.; Hassett, James M.

2005-11-01

188

Mid-Holocene hydrologic model of the Shingobee watershed, Minnesota  

USGS Publications Warehouse

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.

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

2002-01-01

189

Development of a Hydrologic Modeling Platform Using a Workflow Engine  

NASA Astrophysics Data System (ADS)

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

Piasecki, M.; Lu, B.

2010-12-01

190

Using the Workflow Engine TRIDENT as a Hydrologic Modeling Platform  

NASA Astrophysics Data System (ADS)

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

Piasecki, Michael; Lu, Bo

2010-05-01

191

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

NASA Astrophysics Data System (ADS)

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 conceptualizations of hydrology in modeling landscape evolution.

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

2005-12-01

192

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

SciTech Connect

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.

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

2006-05-05

193

Multisource remote sensing supported large scale fully distributed hydrological modeling of the Tarim River Basin in Central Asia  

Microsoft Academic Search

Potential application of remote sensing in hydrology is one of the hot spots in the distributed hydrological model research. The remote sensing technology can be applied to obtain the spatial distribution and dynamics of hydrological phenomena which is not generally possible based on traditional data. In this paper, a fully distributed large scale hydrological modeling application is considered in the

Xianwei Feng; Xi Chen; Patrick Willems; Tie Liu; Lanhai Li; Anming Bao; Yue Huang

2009-01-01

194

Investigating the Optimal Configuration of Conceptual Hydrologic Models for Satellite-Rainfall-Based Flood Prediction  

Microsoft Academic Search

In this letter, we investigated the optimal configuration of conceptual hydrologic models for satellite-rainfall-based flood prediction in the 970-km2 Upper Cumberland basin of Kentucky. We explored the impact of integrating NASA's real-time global satellite rainfall product (IR-3B41RT), available at 0.25deg-hourly resolution, in four conceptual model configurations: three built using the modular Hydrologic Modeling System of the Hydrologic Engineering Center that

Amanda Harris; Faisal Hossain

2008-01-01

195

A hydrological model of New Zealand - version 2  

NASA Astrophysics Data System (ADS)

We report recent progress on a long-term hydrological modelling project whose goal is to make reliable estimates of all water fluxes and storages of New Zealand, and reliable estimates of potential changes in those water resources. This is an ambitious scientific project, with many practical implications for water use and water planning. The model assumes a single model structure (TopNet, see Clark et al 2008), and uses a priori parameter estimation, based on national datasets, without calibration. The model uses an hourly timestep and was run for 40 years. New Zealand's 260,000 sq km area is subdivided into 35,000 subcatchments of about 7 sq km each. Experience with practical applications of a priori parameter estimation have shown that the two parameters of TopNet which lead to the greatest source of uncertainty in river flows are TOPMODF and HYDCON0. These describe the rate of change of saturated soil hydraulic conductivity with depth, and the saturated soil hydraulic conductivity at the ground surface, respectively. We will show results for selected regions and river basins, and assess the model performance against measured soil moisture and snow storage, as well as measured streamflow. As well as being useful as regional and national models, the results provide a sound start for model calibration, if needed. There are opportunities to improve on these results through improved mapping of recession characteristics, improved use of recording raingauge data, and selection of model structure to match the spatial variations in hydrological processes which are not captured by a fixed model structure. This model underpins new regional and national forecasts and climate change assessments which are now in development.

Woods, Ross; Zammit, Christian; Singh, Shailesh; McMillan, Hilary; Henderson, Roddy

2013-04-01

196

Chimaeric HBV core particles carrying a defined segment of Puumala hantavirus nucleocapsid protein evoke protective immunity in an animal model  

Microsoft Academic Search

Hantaviruses are rodent-born agents which are pathogenic in humans causing haemorrhagic fever with renal syndrome or hantavirus pulmonary syndrome. To induce a protective immunity against a European hantavirus (Puumala) we constructed chimaeric hepatitis B virus (HBV) core particles carrying defined fragments of the Puumala virus nucleocapsid protein. After immunisation of bank voles, the natural host of Puumala virus, with core

Rainer Ulrich; Åke Lundkvist; Helga Meisel; Diana Koletzki; Katarina Brus Sjölander; Hans R. Gelderblom; Galina Borisova; Paul Schnitzler; Gholamreza Darai; Detlev H. Krüger

1998-01-01

197

EFFICIENT HYDROLOGICAL TRACER-TEST DESIGN (EHTD) MODEL  

EPA Science Inventory

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

198

Opportunities for Impacting the Trajectory of Hydrologic Model Development (Invited)  

NASA Astrophysics Data System (ADS)

Mathematical models have become mandated tools in addressing hydrologic problems. As computers have become faster and more powerful, our ability to analyze systems over a wide range of temporal and spatial scales has advanced dramatically. Despite this good news, the analytical advances have also revealed shortcomings in our understanding of system behavior and in describing the physics of this behavior mathematically. These shortcomings suggest that the time is opportune to assess the trajectory of model development and seek strategies that will advance model quality, robustness, and utility in contributing to the solutions of problems of societal importance. In this presentation, some reflections and examples of model development will be provided, as well as some thoughts on how to ensure progress.

Gray, W. G.

2010-12-01

199

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

NASA Astrophysics Data System (ADS)

Spatially distributed hydrological model is an important tool for studying the hydrological cycle, making flood forecasting, simulating environmental and ecological processes and estimating crop water demand and so on. Successful distributed hydrological model and systems have been further achieved in many developed countries. However, there needs one GIS based Distributed Hydrological Model system to carry out hydrological simulation suitable for current conditions of China. In this paper a distributed hydrological model system for easy manipulation, MWEasyDHM (MapWindow based Distributed Hydrological Model), was developed based on MapWindow GIS platform, an open source GIS software. The system contains pretreatment, model parameters optimization and posttreatment modules to simplify the works of building distributed hydrological model. The pretreatment module includes hydrological analysis, model parameters estimation and weather data interpolation parts based on huge amount of spatial and temporal data sets such as weather, land use, soil type, etc. With the pretreatment results, distributed hydrological model could be calculated and optimal model parameters could be obtained with LH-OAT parameters sensitivity analysis and SCE-UA parameters optimization. After model simulation, the model results could be displayed with tables, charts and GIS forms, in addition, spatial and temporal statistics and analysis could be easily achieved with the postreatment. Finally, a brief application of MWEasyDHM will be described to demonstrate the flexibilities and capacities of the model system. With the successful development of MWEasyDHM, the processes of model building, calibration and application could be much easier and distributed hydrological model could be easily applied to the areas of water resources management.

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

2010-05-01

200

Tree-based iterative input variable selection for hydrological modeling  

NASA Astrophysics Data System (ADS)

Input variable selection is an important issue associated with the development of several hydrological applications. Determining the optimal input vector from a large set of candidates to characterize a preselected output might result in a more accurate, parsimonious, and, possibly, physically interpretable model of the natural process. In the hydrological context, the modeled system often exhibits nonlinear dynamics and multiple interrelated variables. Moreover, the number of candidate inputs can be very large and redundant, especially when the model reproduces the spatial variability of the physical process. The ideal input selection algorithm should therefore provide modeling flexibility, computational efficiency in dealing with high dimension data set, scalability with respect to input dimensionality and minimum redundancy. In this paper, we propose the tree-based iterative input variable selection algorithm, a novel hybrid model-based/model-free approach specifically designed to fulfill these four requirements. The algorithm structure provides robustness against redundancy, while the tree-based nature of the underlying model ensures the other key properties. The approach is first tested on a well-known benchmark case study to validate its accuracy and subsequently applied to a real-world streamflow prediction problem in the upper Ticino River Basin (Switzerland). Results indicate that the algorithm is capable of selecting the most significant and nonredundant inputs in different testing conditions, including the real-world large data set characterized by the presence of several redundant variables. This permits one to identify a compact representation of the observational data set, which is key to improving the model performance and assisting with the interpretation of the underlying physical processes.

Galelli, S.; Castelletti, A.

2013-07-01

201

Assessing the Effect of Spatial Variability of Precipitation on Hydrologic Processes in Watersheds and Sensitivity Analyses of a Distributed Hydrologic Model  

Microsoft Academic Search

: The effect of spatial variability of precipitation on hydrologic processes was studied using a physically-based spatially-distributed hydrologic model. The sensitivity of the hydrologic model to model parameters was investigated using fractional factorial design method. Point measurements of precipitation in the Monongahela river basin (13,187 km2 areal extent), a sub-basin in the Ohio river basin, were used to obtain the

O. Yildiz; A. P. Barros

2001-01-01

202

Modelling of Hydrological Mass Variation on the Site Modra-Piesok  

NASA Astrophysics Data System (ADS)

Time series of gravity measurements can be used to characterize dynamic changes of subsurface system. However, these measurements can be strongly influenced by hydrological processes especially water mass variations. Therefore, the influence of hydrological effects on gravity needs to be modelled so that the observed gravity can be appropriately corrected. Often, due to the lack of measurements, an accurate local hydrological model is not available and the gravity corrections are affected by an unknown error. In the present-time the absolute gravity measurements have very high accuracy (1 microgal). After all used standard correction the time series of absolute gravity has variation with amplitude 5 microgal. The hydrological mass variation is very often modelled by global, regional and local hydrological effects. For computation of hydrological effects were used global hydrological model WGHM with 0.5° x 0.5° grid. The regional effect was computed from continental hydrological measurements and local effect from local hydrological measurements performed on the site Modra-Piesky. The local effects were controlled by repeated relative gravity measurements. The all hydrological effects were tested by absolute gravity measurements performed on the site Modra-Piesky. The poster presents theoretical and numerical results of the test.

Mojzes, Marcel; Mikolaj, Michal

2010-05-01

203

A high-resolution European dataset for hydrologic modeling  

NASA Astrophysics Data System (ADS)

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 inputs to the hydrological calibration and validation of EFAS as well as for establishing long-term discharge "proxy" climatologies which can then in turn be used for statistical analysis to derive return periods or other time series derivatives. In addition, this dataset will be used to assess climatological trends in Europe. Unfortunately, to date no baseline dataset at the European scale exists to test the quality of the herein presented data. Hence, a comparison against other existing datasets can therefore only be an indication of data quality. Due to availability, a comparison was made for precipitation and temperature only, arguably the most important meteorological drivers for hydrologic models. A variety of analyses was undertaken at country scale against data reported to EUROSTAT and E-OBS datasets. The comparison revealed that while the datasets showed overall similar temporal and spatial patterns, there were some differences in magnitudes especially for precipitation. It is not straightforward to define the specific cause for these differences. However, in most cases the comparatively low observation station density appears to be the principal reason for the differences in magnitude.

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

2013-04-01

204

Hydrologic and geochemical modeling of a karstic Mediterranean watershed  

NASA Astrophysics Data System (ADS)

The SWAT model was modified to simulate the hydrologic and chemical response of karstic systems and assess the impacts of land use management and climate change of an intensively managed Mediterranean watershed in Crete, Greece. A methodology was developed for the determination of the extended karst area contributing to the spring flow as well as the degree of dilution of nitrates due to permanent karst water volume. The modified SWAT model has been able to capture the temporal variability of both karst flow and surface runoff using high frequency monitoring data collected since 2004 in addition to long term flow time series collected since 1973. The overall hydrologic budget of the karst was estimated and its evaporative losses were calculated to be 28% suggesting a very high rate of karst infiltration. Nitrate chemistry of the karst was simulated by calibrating a dilution factor allowing for the estimation of the total karstic groundwater volume to approximately 500 million m3 of reserve water. The nitrate simulation results suggested a significant impact of livestock grazing on the karstic groundwater and on surface water quality. Finally, simulation results for a set of climate change scenarios suggested a 17% decrease in precipitation, 8% decrease in ET and 22% decrease in flow in 2030-2050 compared to 2010-2020. A validated tool for integrated water management of karst areas has been developed, providing policy makers an instrument for water management that could tackle the increasing water scarcity in the island.

Nikolaidis, N. P.; Bouraoui, F.; Bidoglio, G.

2012-01-01

205

Snow Water Equivalent Predictions for Hydrologic Model Input and Simulation  

NASA Astrophysics Data System (ADS)

A multiple regression equation was developed to describe temporal and spatial variability of daily snow water equivalent (SWE) in Lake Tahoe's Incline Creek watershed. SWE maps of the basin are needed for parameterization of the physically-based Alpine Hydrochemical Model (AHM) to simulate basin hydrology and solute transport. SWE maps allow for calculation of snow covered area, snowfall, and potential snowmelt needed for AHM input. SWE data collected during 2002's peak snow accumulation were used in conjunction with data from three local SNOTEL stations to calibrate the regression equation. Calibration was conducted during a dry and average water year using the sum of least squares. The multiple-regression is dependent on elevation, aspect, slope, vegetation density and solar radiation and is normalized by the average SWE measured at the three SNOTEL sites. Basin-wide computations were done at 30 m resolution in ArcView to generate daily SWE maps. Normalized error was added to predictions from the regression equation to mimic the variability in the observed data. Verification was performed at the three SNOTEL sites for a wet year and another average year. Stream response is highly dependent on SWE distribution and associated melt rates such that hydrologic model results allow evaluation of the SWE interpolation technique.

Carroll, R. W.

2003-12-01

206

Linking hydrologic models and data: The OpenMI approach  

NASA Astrophysics Data System (ADS)

Modeling frameworks provide the ability to create open, flexible modeling systems where simulations can be constructed from a set of computational modules interlinked for a given application. Various modeling frameworks have been proposed and developed with varying degrees of success. This paper investigates a more recent modeling framework, the Open Modeling Interface (OpenMI). OpenMI, which is freely available and open source (http://www.openmi.org), was developed by a consortium of public and private organizations in Europe. Various models are either already or in the process of becoming OpenMI compliant (e.g. MIKE-SHE, HEC-RAS, and Modflow). While using OpenMI to link existing models is one application of the framework, we are interested in determining the appropriateness of OpenMI as the underlying architecture for a community based hydrologic modeling system. We investigate this question by showing how the framework would allow a simulation model and database to be coupled, how OpenMI orchestrates the communication between these two components, and how OpenMI could be expanded to accommodate models and databases that are exposed as web services. We conclude with a discussion of the advantages and disadvantages of the OpenMI modeling framework and provide a vision for how a community model might be structured using an OpenMI-based approach.

Goodall, J. L.; Robinson, B. F.; Shatnawi, F. M.; Castronova, A. M.

2007-12-01

207

Hydrological impacts of climate change in the Yellow River Basin for the 21st century using hydrological model and statistical downscaling model  

Microsoft Academic Search

In this study, impacts of climate change on streamflow in the Yellow River Basin are investigated. A semi-distributed hydrological model (SWAT) is calibrated and validated with records at Huayuankou, Lanzhou and Huaxian hydrological stations. Using outputs from a global circulation model (HadCM3), a statistical downscaling model (SDSM) and a combination of ‘bilinear-interpolation and delta’ are applied to generate daily time-series

Lüliu Liu; Zhaofei Liu; Xiyan Ren; Thomas Fischer; Ying Xu

2011-01-01

208

ANNIE - INTERACTIVE PROCESSING OF DATA BASES FOR HYDROLOGIC MODELS.  

USGS Publications Warehouse

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.

Lumb, Alan, M.; Kittle, John, L.

1985-01-01

209

Modeling Soil Depth Based Upon Topographic and Land Cover Attributes to Improve Models of Hydrological Response  

NASA Astrophysics Data System (ADS)

Soil depth is an important input parameter in hydrological modeling. Presently, the soil depth data available in national soil databases (STATSGO, SSURGO) is provided as averages within generalized map units. Spatial uncertainty within these units limits their applicability for distributed hydrological modeling in complex terrain. Statistical models were developed for prediction of soil depth in a semiarid mountainous watershed based upon topographic and land cover attributes. Soil depth was surveyed by driving a rod into the ground until refusal at 819 calibration and 130 independent testing locations selected to represent the topographic and land cover variation in Dry Creek Experimental Watershed, Boise, Idaho. Topographic attributes derived from a Digital Elevation Model (DEM) and Land cover attributes derived from remote sensing were used in Generalized Additive and Random Forest models to predict soil depth over the watershed. The models were able to explain about 50% of the soil depth spatial variation with a significant part of this capability due to new DEM derived topographic variables. The soil depths obtained from these models are being used as input to a spatially distributed hydrological model to evaluate the sensitivity of hydrological response and potential for improvement in hydrological model estimates due to better soil depth information.

Tesfa, T. K.; Tarboton, D. G.; Chandler, D. G.; McNamara, J. P.

2008-12-01

210

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

211

Incorporating Remote Sensing and Geography Information System in Hydrological Modeling of Kaidu Basin, Northwest China  

Microsoft Academic Search

The main obstacles in current distributed hydrological modeling are the lack of sufficient data for driving the models and for parameterization of the land surface and subsurface. This study applied remote sensing (RS) based input data in a hydrological model for the 19012 km2 Kaidu River basin in Northwest China. Based on the geography information system (GIS) technique, the digital

Huang Yue; Chen Xi; Bao Anming; Feng Xianwei

2009-01-01

212

Assimilation of MODIS snow cover area data in a distributed hydrological model  

Microsoft Academic Search

Snow is an important component of the water cycle and its estimation in hydrological models is of great importance concerning snow melting flood events simulations and forecasting. The LISFLOOD model is a spatially distributed hydrological model designed at the Joint Research Centre for large European river basins. It is used for a variety of applications including flood forecasting and assessing

G. Thirel; P. Salamon; P. Burek; M. Kalas

2011-01-01

213

Intercomparsion of global hydrological models in terms of water storage simulations  

NASA Astrophysics Data System (ADS)

Global hydrology modeling is an indispensable tool to study hydrological processes on continental scales. Furthermore, the output of global hydrological models provides an important input for studies on water availability or climate change. Until now, differences between global hydrological models are larger than predicted signals within many regions. This challenges the reliability of single model predictions. In order to understand reasons and sources of these differences, we compare the output of total water storage variations as well as groundwater, soil, snow and canopy storages simulated with three global hydrological models: the Global Land Data Assimilation System (GLDAS), the Land Dynamics model (LaD) and the WaterGAP Global Hydrology Model (WGHM). The main source of model inconsistency originates from the differences in global simulations of soil moisture. The differences between the models are mainly due to different model strategies (including the definition of storage compartments), different process formulations and errors in the input data. We suggest improving model simulations by an increased effort into research of process understandings on continental scales. Furthermore, a successful and world-wide integration of satellite observations of hydrological variables into these models is desirable to reduce uncertainties in global hydrological simulations. For instance, the GRACE (Gravity Recovery and Climate Experiment) mission depicts a useful measurement system to detect and assimilate total water storage changes on the continents.

Guentner, A.; Werth, S.

2008-12-01

214

A hydrologic and geomorphic model of estuary breaching and closure  

NASA Astrophysics Data System (ADS)

To better understand how the hydrology of bar-built estuaries affects breaching and closing patterns, a model is developed that incorporates an estuary hydrologic budget with a geomorphic model of the inlet system. Erosion of the inlet is caused by inlet flow, whereas the only morphologic effect of waves is the deposition of sand into the inlet. When calibrated, the model is able to reproduce the initial seasonal breaching, seasonal closure, intermittent closures and breaches, and the low-streamflow (closed state) estuary hydrology of the Carmel Lagoon, located in Central California. Model performance was tested against three separate years of water-level observations. When open during these years, the inlet was visually observed to drain directly across the beach berm, in accordance with model assumptions. The calibrated model predicts the observed 48-h estuary stage amplitude with root mean square errors of 0.45 m, 0.39 m and 0.42 m for the three separate years. For the calibrated model, the probability that the estuary inlet is closed decreases exponentially with increasing inflow (streamflow plus wave overtopping), decreasing 10-fold in probability as mean daily inflow increases from 0.2 to 1.0 m3/s. Seasonal patterns of inlet state reflect the seasonal pattern of streamflow, though wave overtopping may become the main hydrologic flux during low streamflow conditions, infrequently causing short-lived breaches. In a series of sensitivity analyses it is seen that the status of the inlet and storage of water are sensitive to factors that control the storage, transmission, and inflow of water. By varying individual components of the berm system and estuary storage, the amount of the time the estuary is open may increase by 57%, or decrease by 44%, compared to the amount of time the estuary is open during calibrated model conditions for the 18.2-year model period. The individual components tested are: berm height, width, length, and hydraulic conductivity; estuary hypsometry (storage to stage relationship); two factors that control wave-swash sedimentation of the inlet; and sea level rise. The elevation of the berm determines the volume of water that must enter the estuary in order to breach, and it modulates the wave-overtopping flux and frequency. By increasing estuary storage capacity, the estuary will breach less frequently (- 27% change in time open for modeled excavation scenario) and store water up to 3 months later into the summer. Altering beach aquifer hydraulic conductivity affects inlet state, and patterns of breaching and water storage. As a result of sea-level rise of 1.67 m by 2100, and a beach berm that remains in its current location and accretes vertically, the amount of time the estuary remains open may decrease by 44%. Such a change is an end-member of likely scenarios given that the berm will translate landwards. Model results indicate that the amount of time the estuary is open is more sensitive to changes in wave run-up than the amount of sand deposited in the inlet per each overtopping wave.

Rich, Andrew; Keller, Edward A.

2013-06-01

215

Hydrological modelling of slopes from field monitoring data  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

216

Using Discharge data and hydrological modelling to evaluate precipitation data  

NASA Astrophysics Data System (ADS)

Historical gridded precipitation data can be derived from rain gauge measurements, satellite, radar, reanalysis using atmospherical models, and combinations of these. Evaluation of these products, however, is generally restricted to how well they reproduce point measurements at rain-gauges, leaving large uncertainties regarding the spatial variation of rainfall regions without observations. Climate models also make simulations of historical gridded precipitation and validation of this precipitation is usually made against one or more of the aforementioned historical gridded precipitation products. Here, it is suggested that long-term averages of measured discharge in river basins ranging in scale from 100 km2 to 100 0000 km2 can be used as a proxy for the long-term precipitation totals across the region. Discharge simulated by a hydrological model that is driven by the precipitation data to be evaluated is then compared with the observed discharge. This method therefore rests upon the assumption that long-term volume errors in modelled discharge are caused by errors in the input precipitation fields upstream of the measuring point. Of course errors in prediction of evapotranspiration, losses to deep groundwater and irrigation also have to be taken into account. In this study, a number of gridded precipitation products, both interpolated and reanalysis data, were used to simulate discharge across Europe using a subbasin resolution of 215 km2. As well as intercomparison of the precipitation products and comparison to more detailed national data sets, the error in simulated discharge could be used to indicate regions where the precipitation products were poor. All of the precipitation products evaluated were poor in at least one region of Europe, usually related to the availability of precipitation gauge data in that region when creating the precipitation product. Hydrological science could better contribute to climate sciences by including these sorts of analyses in atmospherical models both for historical reanalysis and climate prediction.

Dahne, J.; Donnelly, C.; Gustavsson, D.; Södling, J.

2012-04-01

217

Translating hydrologically-relevant variables from the ice sheet model SICOPOLIS to the Greenland Analog Project hydrologic modeling domain  

NASA Astrophysics Data System (ADS)

Projecting future climate and ice sheet development requires sophisticated models and extensive field observations. Given the present state of our knowledge, it is very difficult to say what will happen with certainty. Despite the ongoing increase in atmospheric greenhouse gas concentrations, the possibility that a new ice sheet might form over Scandinavia in the far distant future cannot be excluded. The growth of a new Scandinavian Ice Sheet would have important consequences for buried nuclear waste repositories. The Greenland Analogue Project, initiated by the Swedish Nuclear Fuel and Waste Management Company (SKB), is working to assess the effects of a possible future ice sheet on groundwater flow by studying a constrained domain in Western Greenland by field measurements (including deep bedrock drilling in front of the ice sheet) combined with numerical modeling. To address the needs of the GAP project, we interpolated results from an ensemble of ice sheet model runs to the smaller and more finely resolved modeling domain used in the GAP project's hydrologic modeling. Three runs have been chosen with three fairly different positive degree-day factors among those that reproduced the modern ice margin at the borehole position. The interpolated results describe changes in hydrologically-relevant variables over two time periods, 115 ka to 80 ka, and 20 ka to 1 ka. In the first of these time periods, the ice margin advances over the model domain; in the second time period, the ice margin retreats over the model domain. The spatially-and temporally dependent variables that we treated include the ice thickness, basal melting rate, surface mass balance, basal temperature, basal thermal regime (frozen or thawed), surface temperature, and basal water pressure. The melt flux is also calculated.

Vallot, Dorothée; Applegate, Patrick; Pettersson, Rickard

2013-04-01

218

On the spatio-temporal analysis of hydrological droughts from global hydrological models  

NASA Astrophysics Data System (ADS)

The recent concerns for world-wide extreme events related to climate change phenomena have motivated the development of large scale models that simulate the global water cycle. In this context, analyses of extremes is an important topic that requires the adaptation of methods used for river basin and regional scale models. This paper presents two methodologies that extend the tools to analyze spatio-temporal drought development and characteristics using large scale gridded time series of hydrometeorological data. The methodologies are distinguished and defined as non-contiguous and contiguous drought area analyses (i.e. NCDA and CDA). The NCDA presents time series of percentages of areas in drought at the global scale and for pre-defined regions of known hydroclimatology. The CDA is introduced as a complementary method that generates information on the spatial coherence of drought events at the global scale. Spatial drought events are found through CDA by clustering patterns (contiguous areas). In this study the global hydrological model WaterGAP was used to illustrate the methodology development. Global gridded time series (resolution 0.5°) simulated with the WaterGAP model from land points were used. The NCDA and CDA were applied to identify drought events in subsurface runoff. The percentages of area in drought calculated with both methods show complementary information on the spatial and temporal events for the last decades of the 20th century. The NCDA provides relevant information on the average number of droughts, duration and severity (deficit volume) for pre-defined regions (globe, 2 selected climate regions). Additionally, the CDA provides information on the number of spatially linked areas in drought as well as their geographic location on the globe. An explorative validation process shows that the NCDA results capture the overall spatio-temporal drought extremes over the last decades of the 20th century. Events like the El Niño Southern Oscillation (ENSO) in South America and the pan-European drought in 1976 appeared clearly in both analyses. The methodologies introduced provide an important basis for the global characterization of droughts, model inter-comparison, and spatial events validation.

Corzo Perez, G. A.; van Huijgevoort, M. H. J.; Voß, F.; van Lanen, H. A. J.

2011-01-01

219

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

NASA Astrophysics Data System (ADS)

The community land model (CLM) was primarily designed for coupling with atmospheric models to simulate water, energy, and carbon fluxes between the land surface and atmosphere. In principle, CLM can be run at any resolution, however, validations were mostly conducted at large river basin, continental, or global scales for studies on inter-annual and inter-decadal variability, paleoclimate regimes, and projections of future changes of the global climate system, with limited case studies at flux tower sites and small watersheds. With the emergence of integrated earth system models (iESMs) at global and regional scales, and increasing interests of applying CLM at finer resolutions, it is critical to evaluate and improve the capability of CLM for hydrologic simulations at various scales, so that CLM could be used to represent hydrology, soil, managed and unmanaged ecosystems, and biogeochemical processes across scales, and provide hydrologic information being passed through all the components in a single modeling framework of iESMs. In this presentation, we will report our efforts on the development and validation of CLM hydrologic processes 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; and (3) applications of CLM at multiple scales ranging from flux towers, small and large watersheds, to continental scales.

Huang, M.; Ke, Y.; Li, H.; Liu, Y.; Wigmosta, M. S.; Coleman, A.; Leung, L.

2011-12-01

220

GIS embedded hydrological modeling: the SID&GRID project  

NASA Astrophysics Data System (ADS)

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 the unsaturated/saturated flow model. At this stage of the research (which will end April 2013), two primary components of the master control panel are being developed: i. a SID&GRID toolbar integrated into gvSIG map context; ii. a new Sextante set of geo-algorithm to pre- and post-process the spatial data to run the hydrological models. The groundwater part of the code has been fully integrated and tested and 3D visualization tools are being developed. The LGR capability has been extended to the 3D solution of the Richards' equation in order to solve in detail the unsaturated zone where required. To be updated about the project, please follow us at the website: http://ut11.isti.cnr.it/SIDGRID/

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

2012-04-01

221

Diagnosing non-stationary behaviour in a hydrological model  

NASA Astrophysics Data System (ADS)

The stationarity of hydrological models is increasingly being called into question, due partly to changes in land cover as well as natural and anthropogenic climate change. This issue is manifest in model parameters which change over time, creating challenges in calibration and validation (as the joint distribution of model parameters is conditional to the period used for model calibration), and in prediction when one wishes to investigate runoff properties in the future. This paper describes the incorporation of non-stationary parameters into a well established rainfall-runoff model - GR4J - using a Bayesian framework for calibration and prediction, and the use of an information theoretic approach to evaluate whether the inclusion of non-stationary parameters was justified. A subcatchment of the Onkaparinga river in South Australia was used as a case study, and it was found that GR4J parameter 'x1' varied significantly seasonally and also exhibited a longer-term increasing trend over the calibration period from 1974 to 1999. The inclusion of this non-stationary parameter in the model reduced the over-prediction in the drier validation period from 2000 to 2010 from 25% to 1.5%. Whilst including non-stationarity parameters provided substantial improvements in prediction, it is advocated that this non-stationary parameters be used as a diagnostic tool to identify model deficiencies, rather than for prediction. Techniques to reduce the non-stationarity by enhancing the model structure will to include one or more missing processes will be discussed.

Thyer, Mark; Westra, Seth; Leonard, Michael; Kavetski, Dmitri; Lambert, Martin

2013-04-01

222

Is point uncertain rainfall likely to have a great impact on distributed complex hydrological modeling?  

NASA Astrophysics Data System (ADS)

Uncertainty analysis has become an important topic in environmental research. Uncertainty in hydrological modeling, in general, has been studied by investigating mainly the influence of the parameter uncertainty on the uncertainty of the simulated outputs. This paper focuses essentially on the impact of point input uncertainty on fully distributed hydrological modeling and proposes an integrated approach to cope with input and parameter uncertainty. The approach uses Bayesian theory in two steps: first, to compute the uncertainty in input forcing data, and second, to compute the hydrological parameter uncertainty and the uncertainties of a lumped-error term that include other sources of errors: response errors and model error. The method is applied with a fully distributed model: WaSiM-ETH. The results show that the methodology proposed here is a valuable tool to assess different sources of uncertainty in hydrological modeling and show the effects of uncertainty in the input forcing when a fully distributed, physically based hydrological model is used.

Balin, Daniela; Lee, Hyosang; Rode, Michael

2010-11-01

223

A conceptual model simulating the hydrological processes on a drainage basin in a plain area  

Microsoft Academic Search

A conceptual model is proposed to simulate the hydrological processes on drainage basin in plain area where the vertical fluxes predominate and where the groundwater table is very close to the surface and, therefore, the interaction between surface water and groundwater should be taken into account. The hydrological components of the system are described in the model by means of

Xin Ren Liu

224

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...

225

Continuous hydrological modelling in the context of real time flood forecasting in alpine Danube tributary catchments  

Microsoft Academic Search

A hydrological modelling framework applied within operational flood forecasting systems in three alpine Danube tributary basins, Traisen, Salzach and Enns, is presented. A continuous, semi-distributed rainfall-runoff model, accounting for the main hydrological processes of snow accumulation and melt, interception, evapotranspiration, infiltration, runoff generation and routing is set up. Spatial discretization relies on the division of watersheds into subbasins and subsequently

Philipp Stanzel; Bianca Kahl; Ulrich Haberl; Mathew Herrnegger; H. P. Nachtnebel

2008-01-01

226

ELIMINATING UNCERTAINTY ASSOCIATED WITH CLASSIFYING SOIL TYPES IN DISTRIBUTED HYDROLOGIC MODELING  

Microsoft Academic Search

This paper presents a method to estimate the parameter values associated with soil characteristics in a distributed hydrologic model. The new approach accounts for all soil types in a catchment, regardless of the number of soil types present, eliminating the need for subjective soil reclassification methods and more accurately approximating the true physical characteristics of the catchment. The hydrologic model

HAPUARACHCHIGE P. HAPUARACHCHI; ANTHONY S. KIEM; HIROSHI ISHIDAIRA; JUN MAGOME; KUNIYOSHI TAKEUCHI

227

Simulated Climatology of a General Circulation Model with a Hydrologic CYCLE1  

Microsoft Academic Search

A numerical experiment with a general circulation model with a simple hydrologic cycle is performed. The basic framework of this model is identical with that adopted for the previous study (35) except for the incorporation of a simplified hydrologic cycle which consists of the advection of water vapor by large-scale motion, evaporation from t.he surface, precipitation, and an artificial adjustment

Syukuro Manabe; Joseph Smagorinsky; Robert F. Strickler

1965-01-01

228

Fractionally differenced ARIMA models applied to hydrologic time series: Identification, estimation, and simulation  

Microsoft Academic Search

Since Hurst [1951] detected the presence of long-term persistence in hydrologic data, new estimation methods and long-memory models have been developed. The lack of flexibility in representing the combined effect of short and long memory has been the major limitation of stochastic models used to analyze hydrologic time series. In the present paper a fractionally differenced autoregressive integrated moving average

Alberto Montanari; Renzo Rosso; Murad S. Taqqu

1997-01-01

229

Application of The Hydrology Lab Research Modeling System (hl-rms) For Large Headwater Catchments  

Microsoft Academic Search

The Hydrology Lab (HL) of the National Weather Service Office of Hydrologic De- velopment is actively engaged in research and development into catchment modeling approaches to improve the ability to forecast river flows. Traditionally, conceptual lumped models have been used to produce operational river forecasts, and they of- ten produce reasonable results provided their parameters were calibrated properly. A common

V. Koren; M. Smith; S. Reed; Z. Zhang

2002-01-01

230

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

EPA Science Inventory

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

231

The seasonal variation of the hydrologic cycle as simulated by a global model of the atmosphere  

Microsoft Academic Search

The seasonal variation of the global hydrologic cycle is comprehensively described with a mathematical model of the atmosphere. The model has 11 levels from 80 m to 31 km above sea level and realistic continents with smoothed topography, and it simulates rainfall, snowfall, and evaporation at the surface. The simulated precipitation and other hydrologic quantities are compared with observed data,

Syukuro Manabe; J. L. Holloway Jr.

1975-01-01

232

Characterising the hydrological response to climate change of a remote tropical mountainous catchment: a multi-model approach  

NASA Astrophysics Data System (ADS)

Process-based conceptual rainfall-runoff models are useful to understand runoff generation at different time and spatial resolutions. Contrary to physically-based models, they do not rely much on field observations (e.g. soil physical properties) which may not be available everywhere. Instead, these mathematical tools close the water balance and predict runoff as a function of some empirical parameters. Since corresponding values are hardly measurable, modellers usually proceed to a calibration against available observations to obtain an acceptable match between observations and predictions. However, in the case of poorly monitored areas such as elevated catchments in the Andean Cordillera, good high frequency calibration data available over a long time span are scarce. Therefore, in spite of the development of multiple effective automatized calibration techniques in recent years, results remain uncertain because of the non-uniqueness of optimal parameter sets. A state-of-the-art option to cope with this predictive uncertainty is to consider ensembles of predictions rather than single ones. Furthermore, by gathering more independent parameterisations of the same processes, multi-model approaches allow a better representation of the uncertainty than multiple realisations of the same, eventually biased, model structure subjectively chosen by the modeller based on previous experience or project requirements. As a demonstration of the usefulness of this approach in scarcely-monitored areas, we present here results of an ensemble of heterogeneous rainfall-runoff models applied to the remote San Francisco (75 km2) tropical montane forest catchment, located in the southern part of Ecuador. Each of the 7 models (CHIMP, HBV-D, HBV-light, HMS, LASCAM, NAM, SWAT) is applied to simulate runoff whilst being forced by 6 increasingly uncertain meteorological data: on-site precipitation gauges record (also used for calibration), bias-corrected downscaled re-analysis (SDSM) output of the CCSM Regional Climate Model (RCM) over the first decade of the 21st century, and output of the same RCM forced by two different IPCC emission scenarios (A1B, B1) for two decades of the middle (2050-2059) and the end of the current century (2090-2099). Results show that the annual cumulative runoff and maximum flows should increase in this area during the 21st century. Furthermore, in spite of a good agreement in the timing of seasonal runoff patterns between rainfall-runoff models forced by the same input data, there is a great variability in the magnitude of predicted extreme values. The uncertainty in the RCM emission scenarios is not greater than the uncertainty between hydrological model predictions but the ensemble still allows targeting the most probable future.

Exbrayat, J.-F.; Timbe, E.; Plesca, I.; Kraft, P.; Windhorst, D.; Trachte, K.; Buytaert, W.; Breuer, L.

2012-04-01

233

Generating Distributed Forcing Fields for Spatial Hydrologic Modeling  

NASA Astrophysics Data System (ADS)

Spatial hydrologic modeling requires the development of distributed forcing fields of weather and precipitation. This is particularly difficult in mountainous regions of the western US, where measurement sites are limited and the landscape is dominated by complex terrain and variations in vegetation cover. The Reynolds Creek Experimental Watershed (RCEW), in southwestern Idaho offers a unique opportunity to evaluate the sensitivity of interpolation techniques to the number and location of measurement sites. The RCEW, a 239 km2 hydro-climatic observatory operated by the USDA Agricultural Research Service since the early 1960's, contains 36 hydro-climatic measurement sites for monitoring the range of weather, snow and precipitation conditions across this complex mountain watershed. The MicroMet weather distribution utility, a process and topographically based weather interpolation tool (Liston and Elder, 2006), is used to generate surfaces of temperature, humidity, wind and precipitation over the snow-dominated 55 km2 (elevation range1398-2244m) Tollgate sub-catchment of RCEW. Nineteen meteorological stations were used to simulate the distribution of weather and precipitation for a series of storms during the 2004 water year. Measured and simulated values were compared to evaluate the accuracy of the model, and a jackknife approach was used to evaluate its sensitivity to data from particular stations. To evaluate the effect of elevation and storm track, different combinations of stations were selected, and to evaluate topographic exposure and vegetation shelter stations were divided into groups based on wind exposure. Results show that, even using a sophisticated weather distribution utility like MicroMet, the interpolation is very sensitive to station location and wind exposure. A certain amount of smoothing occurs even when using all 19 stations, but significant differences occur if only protected sites (similar to NRCS Snotel sites), or only wind-exposed sites are used. This research shows that citing hydro-meteorological monitoring stations is critical to improved hydrologic modeling in mountainous regions.

Nayak, A.; Marks, D.; Chandler, D.; Winstral, A.

2006-12-01

234

Analyzing Catchment Hydrologic Function through Process-based Behavioral Modeling  

NASA Astrophysics Data System (ADS)

Catchment classification should be based on the understanding of how climatic conditions and catchment characteristics control catchment function (partitioning, storage, and release). Such understanding can come from the reconciliation of data and theory, requiring both top-down and bottom-up approaches. While a top-down approach can be used to classify catchments by constructing groups of hydrologically similar catchments, a bottom-up approach is needed to further understand the internal functional differences of catchments within each group. In this study a parsimonious process based model was developed to analyze catchment function across climatic gradients. The soil moisture hillslope-storage Boussinesq Catchment Model (SM-hsB) simulates the diurnal dynamics of the energy and water fluxes at the land surface, vertical recharge/capillary rise to/from the water table, the lateral movement of water from the unconfined hillslope aquifers into the channel network, and the routing of surface water to the catchment’s outlet. SM-hsB was used to define behavioral parameter sets for 12 catchments from the MOPEX database. Comparison of these parameter sets provides insight on how catchments functions interact to produce distinctive hydrologic response. These behavioral models were then used to perform “virtual experiments”. For example, catchments were “geographical relocated” to analyze their filtering effect on different climatic signals. Geology, geomorphology, and vegetation descriptors of the catchment were shuffled, providing interesting insights on their relative roles on catchment responses. Results of these experiments complement an empirical analysis of catchment responses, climate drivers and landscape characteristics (Sawicz et al., this session).

Carrillo, G. A.; Troch, P. A.; Sivapalan, M.; Wagener, T.; Sawicz, K. A.

2010-12-01

235

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

Microsoft Academic Search

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

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

236

Radiative-convective model with an explicit hydrologic cycle. 1: Formulation and sensitivity to model parameters  

Microsoft Academic Search

A hydrological cycle is explicitly included in a one-dimensional radiative-convective equilibrium model which is coupled to a `swamp` surface and tested with various cumulus convection schemes: the hard and soft convective adjustment schemes, the Kuo scheme, the Goddard Institute for Space Studies (GISS) (1974) model 1 scheme, the GISS (1983) model 2 scheme, and the Emanuel scheme. The essential difference

N. O. Renno; Kerry A. Emanuel; Peter H. Stone

1994-01-01

237

Holistic versus monomeric strategies for hydrological modelling of modified hydrosystems  

NASA Astrophysics Data System (ADS)

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 as extended surface-groundwater interactions, ill-defined boundaries, sinks to the sea and anthropogenic intervention with unmeasured abstractions both from surface and groundwater. Criteria for comparison are the physical consistency of parameters, the reproduction of runoff hydrographs at multiple sites within the basin, the likelihood of uncontrolled model outputs, the required amount of computational effort and the performance within a stochastic simulation setting.

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

2010-10-01

238

Bayesian analysis of input uncertainty in hydrological modeling: 2. Application  

NASA Astrophysics Data System (ADS)

The Bayesian total error analysis (BATEA) methodology directly addresses both input and output errors in hydrological modeling, requiring the modeler to make explicit, rather than implicit, assumptions about the likely extent of data uncertainty. This study considers a BATEA assessment of two North American catchments: (1) French Broad River and (2) Potomac basins. It assesses the performance of the conceptual Variable Infiltration Capacity (VIC) model with and without accounting for input (precipitation) uncertainty. The results show the considerable effects of precipitation errors on the predicted hydrographs (especially the prediction limits) and on the calibrated parameters. In addition, the performance of BATEA in the presence of severe model errors is analyzed. While BATEA allows a very direct treatment of input uncertainty and yields some limited insight into model errors, it requires the specification of valid error models, which are currently poorly understood and require further work. Moreover, it leads to computationally challenging highly dimensional problems. For some types of models, including the VIC implemented using robust numerical methods, the computational cost of BATEA can be reduced using Newton-type methods.

Kavetski, Dmitri; Kuczera, George; Franks, Stewart W.

2006-03-01

239

Dynamic Neural Networks for Nonstationary Hydrological Time Series Modeling  

Microsoft Academic Search

Evidence of nonstationary trends in hydrological time series, which result from natural and\\/or anthropogenic climatic variability\\u000a and change, has raised a number of questions as to the adequacy of conventional statistical methods for long-term (seasonal\\u000a to annual) hydrologic time series forecasting. Most conventional statistical methods that are used in hydrology will suffer\\u000a from severe limitations as they assume a stationary

P. Coulibaly; C. K. Baldwin

240

A Bayesian perspective on input uncertainty in model calibration: Application to hydrological model ``abc''  

NASA Astrophysics Data System (ADS)

The impact of input errors in the calibration of watershed models is a recurrent theme in the water science literature. It is now acknowledged that hydrological models are sensitive to errors in the measures of precipitation and that those errors bias the model parameters estimated via the standard least squares (SLS) approach. This paper presents a Bayesian uncertainty framework allowing one to account for input, output, and structural (model) uncertainties in the calibration of a model. Using this framework, we study the impact of input uncertainty on the parameters of the hydrological model "abc." Mostly of academic interest, the "abc" model has a response linear to its input, allowing the closed form integration of nuisance variables under proper assumptions. Using those analytical solutions to compute the posterior density of the model parameters, some interesting observations can be made about their sensitivity to input errors. We provide an explanation for the bias identified in the SLS approach and show that in the input error context the prior on the input "true" value has a significant influence on the parameters' posterior density. Overall, the parameters obtained from the Bayesian method are more accurate, and the uncertainty over them is more realistic than with SLS. This method, however, is specific to linear models, while most hydrological models display strong nonlinearities. Further research is thus needed to demonstrate the applicability of the uncertainty framework to commonly used hydrological models.

Huard, David; Mailhot, Alain

2006-07-01

241

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

NASA Astrophysics Data System (ADS)

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 terms of runoff and variable states of soil and snow over a simulation period 2000 - 2009. The parameters of the model were hand-adjusted based on rational sense, observational data and available understanding of underlying processes. For the first run some processes as riparian vegetation impact on runoff and streamflow/groundwater interaction were handled in a conceptual way. It was shown that the use of Hydrograph model which requires modest amount of parameter calibration may serve also as a quality control for observations. Based on the obtained parameters values and process understanding at the research watershed the model was applied to the larger scale watersheds located in similar environment - the Boise River at South Fork (1660 km2) and Twin Springs (2155 km2). The evaluation of the results of such upscaling will be presented.

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

2011-12-01

242

Hydrologic modeling of two glaciated watersheds in Northeast Pennsylvania  

USGS Publications Warehouse

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 Purdy Creek, the total volume of observed streamflow during the entire simulation period was 13.36??106 m3 and the simulated streamflow volume was 13.82??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.

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

1998-01-01

243

An eco-hydrologic model of malaria outbreaks  

NASA Astrophysics Data System (ADS)

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.

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

2012-03-01

244

A coupled energy transport and hydrological model for urban canopies  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

245

Large Scale Hydrological Modelling: Parameterisation of Groundwater Recharge  

NASA Astrophysics Data System (ADS)

There is currently worldwide interest in the effect of human activity on the global environment, especially the effect of greenhouse gases and land-use change on the global climate, and models are being developed to study both global and local effects of global changes. This research involves the development and application of GRASP (Groundwater Recharge modelling Approach with a Scaling-up Procedure) intended as a component of UP (Upscaled physically based) large-scale hydrological model. GRASP comprises two modelling schemes: SM (Soil Moisture approach) and TF (Transfer Function approach), both based on the one-dimensional Richards' equation. TF is a transfer function model for inhomogeneous vertical flow in the unsaturated zone and gives the recharge response for a short pulse of infiltration at the ground surface or percolation from the root zone. TF is point-based and its parameters are physically-based, derived using the matric potential and unsaturated hydraulic conductivity functions. SM is a simple, computationally efficient, grid-based, two parameters scheme, which are derived based on TF's point-scale aggregated response. Since TF is linear, upscaled transfer functions can be derived through area-weighted summation of point scale transfer functions. Two applications of GRASP are shown, one using data for Little Washita catchment in the ARRB (USA) and another using data from ABRACOS experiment in Central Amazon (Brazil). Although completely validation of the GRASP model needs more data, as shown, results are quite encouraging.

Pimenteldasilva, L.

2002-12-01

246

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

USGS Publications Warehouse

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. Depth to bedrock in the lower Walker River basin ranges from about 900 to 2,000 feet. The average hydraulic conductivity of the alluvial aquifer in the lower Walker River basin is 10-30 feet per day, except where comprised of fluvial sediments. Fluvial sediments along the Walker River have an average hydraulic conductivity of 70 feet per day. Subsurface flow was estimated to be 2,700 acre-feet per year through Double Spring. Subsurface discharge to Walker Lake was estimated to be 4,400 acre-feet per year from the south and 10,400 acre-feet per year from the north. Groundwater levels and groundwater storage have declined steadily in most of Smith and Mason Valleys since 1960. Groundwater levels around Schurz, Nevada, have changed little during the past 50 years. In the Whisky Flat area south of Hawthorne, Nevada, agricultural and municipal pumpage has lowered groundwater levels since 1956. The water-level decline in Walker Lake since 1882 has caused the surrounding alluvial aquifer to drain and groundwater levels to decline. The Wabuska streamflow-gaging station in northern Mason Valley demarcates the upper and lower Walker River basin. The hydrology of the lower Walker River basin is considerably different than the upper basin. The upper basin consists of valleys separated by consolidated-rock mountains. The alluvial aquifer in each valley thins or pinches out at the downstream end, forcing most groundwater to discharge along the river near where the river is gaged. The lower Walker River basin is one surface-water/groundwater system of losing and gaining reaches from Wabuska to Walker Lake, which makes determining stream losses and the direction and amount of subsurface flow difficult. Isotopic data indicate surface water and groundwater in the lower Walker River basin are from two sources of precipitation that have evaporated. The Walker River, groundwater along the Wassuk Range, and Walker Lake plot along one evaporation line. Groundwater along th

Lopes, Thomas J.; Allander, Kip K.

2009-01-01

247

Assessing hydrological impact of potential land use change through hydrological and land use change modeling for the Kishwaukee River basin (USA)  

Microsoft Academic Search

We connected a cellular, dynamic, spatial urban growth model and a semi-distributed continuous hydrology model to quantitatively predict streamflow in response to possible future urban growth at a basin scale. The main goal was to demonstrate the utility of the approach for informing public planning policy and investment choices. The Hydrological Simulation Program—Fortran (HSPF) was set up and calibrated for

Woonsup Choi; Brian M. Deal

2008-01-01

248

State updating of a distributed hydrological model with Ensemble Kalman Filtering: effects of updating frequency and observation network density on forecast accuracy  

NASA Astrophysics Data System (ADS)

This paper presents a study on the optimal setup for discharge assimilation within a spatially distributed hydrological model. The Ensemble Kalman filter (EnKF) is employed to update the grid-based distributed states of such an hourly spatially distributed version of the HBV-96 model. By using a physically based model for the routing, the time delay and attenuation are modelled more realistically. The discharge and states at a given time step are assumed to be dependent on the previous time step only (Markov property). Synthetic and real world experiments are carried out for the Upper Ourthe (1600 km2), a relatively quickly responding catchment in the Belgian Ardennes. We assess the impact on the forecasted discharge of (1) various sets of the spatially distributed discharge gauges and (2) the filtering frequency. The results show that the hydrological forecast at the catchment outlet is improved by assimilating interior gauges. This augmentation of the observation vector improves the forecast more than increasing the updating frequency. In terms of the model states, the EnKF procedure is found to mainly change the pdfs of the two routing model storages, even when the uncertainty in the discharge simulations is smaller than the defined observation uncertainty.

Rakovec, O.; Weerts, A. H.; Hazenberg, P.; Torfs, P. J. J. F.; Uijlenhoet, R.

2012-09-01

249

Integrating hydrologic modeling and land use projections for evaluation of hydrologic response and regional water supply impacts in semi-arid environments  

Microsoft Academic Search

Semi-arid environments are generally more sensitive to urbanization than humid regions in terms of both hydrologic modifications\\u000a and water resources sustainability. The current study integrates hydrologic modeling and land use projections to predict long-term\\u000a impacts of urbanization on hydrologic behavior and water supply in semi-arid regions. The study focuses on the Upper Santa\\u000a Clara River basin in northern Los Angeles

Minxue HeTerri; Terri S. Hogue

250

Parameterization of a hydrological model using remote sensing data  

NASA Astrophysics Data System (ADS)

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 model interface to manage input and output data based on grid cells. This enabled us to model the changes in evapotranspiration patterns in the catchment with changing land use more realistically and to calculate the water balance for each grid cell without losing its geographic reference. Therefore, the grid cells can interact with each other and exchange matter and energy, which was not possible using the sub-watershed approach. Therefore, the grid-cell interface enables the implementation of remote sensing data to provide a spatially distributed modelling.

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

2012-04-01

251

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

USGS Publications Warehouse

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

Driscoll, Daniel G.; Norton, Parker A.

2009-01-01

252

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

Microsoft Academic Search

This paper examines several multi-model combination techniques: the Simple Multi-model Average (SMA), the Multi-Model Super Ensemble (MMSE), Modified Multi-Model Super Ensemble (M3SE) and the Weighted Average Method (WAM). These model combination techniques were evaluated using the results from the Distributed Model Intercomparison Project (DMIP), an international project sponsored by the National Weather Service (NWS) Office of Hydrologic Development (OHD). All

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

2005-01-01

253

Comparison of hydrological model structures based on recession and low flow simulations  

NASA Astrophysics Data System (ADS)

Low flows are often poorly reproduced by commonly used hydrological models, which are traditionally designed to meet peak flow situations. Hence, there is a need to improve hydrological models for low flow prediction. This study assessed the impact of model structure on low flow simulations and recession behaviour using the Framework for Understanding Structural Errors (FUSE). FUSE identifies the set of subjective decisions made when building a hydrological model and provides multiple options for each modeling decision. Altogether 79 models were created and applied to simulate stream flows in the snow dominated headwater catchment Narsjø in Norway (119 km2). All models were calibrated using an automatic optimisation method. The results showed that simulations of summer low flows were poorer than simulations of winter low flows, reflecting the importance of different hydrological processes. The model structure influencing winter low flow simulations is the lower layer architecture, whereas various model structures were identified to influence model performance during summer.

Staudinger, M.; Stahl, K.; Seibert, J.; Clark, M. P.; Tallaksen, L. M.

2011-11-01

254

Comparison of hydrological model structures based on recession and low flow simulations  

NASA Astrophysics Data System (ADS)

Low flows are often poorly reproduced by commonly used hydrological models, which are traditionally designed to meet peak flow situations. Hence, there is a need to improve hydrological models for low flow prediction. This study assessed the impact of model structure on low flow simulations and recession behaviour using the Framework for Understanding Structural Errors (FUSE). FUSE identifies the set of subjective decisions made when building a hydrological model, and provides multiple options for each modeling decision. Altogether 79 models were created and applied to simulate stream flows in the snow dominated headwater catchment Narsjø in Norway (119 km2). All models were calibrated using an automatic optimisation method. The results showed that simulations of summer low flows were poorer than simulations of winter low flows, reflecting the importance of different hydrological processes. The model structure influencing winter low flow simulations is the lower layer architecture, whereas various model structures were identified to influence model performance during summer.

Staudinger, M.; Stahl, K.; Seibert, J.; Clark, M. P.; Tallaksen, L. M.

2011-07-01

255

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

NASA Astrophysics Data System (ADS)

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

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

2004-12-01

256

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

SciTech Connect

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 ?-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 produce hydrologically plausible results. With the BCSD method, the RCM-derived hydrology was more sensitive to climate change than the PCM-derived hydrology.

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

2004-01-01

257

A global hydrological model for deriving water availability indicators: model tuning and validation  

Microsoft Academic Search

Freshwater availability has been recognized as a global issue, and its consistent quantification not only in individual river basins but also at the global scale is required to support the sustainable use of water. The WaterGAP Global Hydrology Model WGHM, which is a submodel of the global water use and availability model WaterGAP 2, computes surface runoff, groundwater recharge and

Petra Döll; Frank Kaspar; Bernhard Lehner

2003-01-01

258

A process-based diagnostic approach to model evaluation: Application to the NWS distributed hydrologic model  

Microsoft Academic Search

Distributed hydrological models have the potential to provide improved streamflow forecasts along the entire channel network, while also simulating the spatial dynamics of evapotranspiration, soil moisture content, water quality, soil erosion, and land use change impacts. However, they are perceived as being difficult to parameterize and evaluate, thus translating into significant predictive uncertainty in the model results. Although a priori

Koray K. Yilmaz; Hoshin V. Gupta; Thorsten Wagener

2008-01-01

259

A JAVA-BASED, OBJECT-ORIENTED MODELING SYSTEM FOR SOUTHERN AFRICAN HYDROLOGY  

Microsoft Academic Search

An object-oriented modeling system, ACRU2000 (Agricultural Catchments Research Unit 2000), was created to enable users to simulate the hydrological and environmental effects of various land uses in the Republic of South Africa. The ACRU2000 modeling system was entirely re-designed and re-coded from the concepts used in the previously developed ACRU agro-hydrological model. The model was designed in the Unified Modeling

G. A. Kiker; D. J. Clark; C. J. Martinez; R. E. Schulze

260

Influences of Soil Dataset Resolution on Hydrologic Modeling  

NASA Astrophysics Data System (ADS)

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

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

2006-10-01

261

Disinformative data in large-scale hydrological modelling  

NASA Astrophysics Data System (ADS)

Large-scale hydrological modelling has become an important tool for the study of global and regional water resources, climate impacts, and water-resources management. However, modelling efforts over large spatial domains are fraught with problems of data scarcity, uncertainties and inconsistencies between model forcing and evaluation data. Model-independent methods to screen and analyse data for such problems are needed. This study aimed at identifying data inconsistencies in global datasets using a pre-modelling analysis, inconsistencies that can be disinformative for subsequent modelling. The consistency between (i) basin areas for different hydrographic datasets, and (ii) between climate data (precipitation and potential evaporation) and discharge data, was examined in terms of how well basin areas were represented in the flow networks and the possibility of water-balance closure. It was found that (i) most basins could be well represented in both gridded basin delineations and polygon-based ones, but some basins exhibited large area discrepancies between flow-network datasets and archived basin areas, (ii) basins exhibiting too-high runoff coefficients were abundant in areas where precipitation data were likely affected by snow undercatch, and (iii) the occurrence of basins exhibiting losses exceeding the potential-evaporation limit was strongly dependent on the potential-evaporation data, both in terms of numbers and geographical distribution. Some inconsistencies may be resolved by considering sub-grid variability in climate data, surface-dependent potential-evaporation estimates, etc., but further studies are needed to determine the reasons for the inconsistencies found. Our results emphasise the need for pre-modelling data analysis to identify dataset inconsistencies as an important first step in any large-scale study. Applying data-screening methods before modelling should also increase our chances to draw robust conclusions from subsequent model simulations.

Kauffeldt, A.; Halldin, S.; Rodhe, A.; Xu, C.-Y.; Westerberg, I. K.

2013-07-01

262

Modeling the impact of hydrological changes on nitrate transport in the Mississippi River Basin from 1955 to 1994  

Microsoft Academic Search

The export of nitrate by the Mississippi River to the Gulf of Mexico has tripled since the 1950s primarily due to an increase in agricultural fertilizer application and hydrological changes. Here we have adapted two physically based models, the Integrated Biosphere Simulator (IBIS) terrestrial ecosystem model and the Hydrological Routing Algorithm (HYDRA) hydrological transport model, to simulate the nitrate export

Simon D. Donner; Michael T. Coe; John D. Lenters; Tracy E. Twine; Jonathan A. Foley

2002-01-01

263

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

Microsoft Academic Search

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

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

2008-01-01

264

What is the ability of distributed hydrologic models to reproduce observed spatial soil moisture fields?  

Microsoft Academic Search

A common approach of evaluating distributed hydrologic models is to compare predicted and observed streamflows. Although the total runoff generated in a watershed is compared with observed sreamflow, it is often difficult to understand what is going on inside the watershed as many possible scenarios can result in the same integrated response. Spatiotemporal datasets from intensive hydrological field experiments offer

M. Gebremichael; E. R. Vivoni

2007-01-01

265

Hydrologic Response of a Wetland to Changing Moisture Conditions: Modeling Effects of Soil Heterogeneity  

Microsoft Academic Search

Prediction of the effects of external influences such as climate change on wetland systems requires the prediction of hydrologic effects. Because wetland soils are typically heterogeneous, it is particularly important to understand the extent and connectedness of hydraulically conductive soil units, since water flow may be concentrated in such units while bypassing others of lower conductivity. However, subsurface hydrologic models

Peter J. Zeeb; Harold F. Hemond

1998-01-01

266

The cold regions hydrological model: a platform for basing process representation and model structure on physical evidence  

Microsoft Academic Search

After a programme of integrated field and modelling research, hydrological processes of considerable uncertainty such as snow redistribution by wind, snow interception, sublimation, snowmelt, infiltration into frozen soils, hillslope water movement over permafrost, actual evaporation, and radiation exchange to complex surfaces have been described using physically based algorithms. The cold regions hydrological model (CRHM) platform, a flexible object-oriented modelling system

J. W. Pomeroy; D. M. Gray; T. Brown; N. R. Hedstrom; W. L. Quinton; R. J. Granger; S. K. Carey

2007-01-01

267

Linking Hydrologic Modeling and Ecologic Modeling: An Application of Adaptive Ecosystem Management in the Everglades Mangrove Zone of Florida Bay  

Microsoft Academic Search

Abstract: The Across Trophic Levels System Simulator (ATLSS) is a suite of ecological models designed toassess the impact of changes in hydrology on biotic components of the southern Florida ecosystem. ATLSSimplements a multimodeling approach that utilizes process models for lower trophic levels, structured populationmodels for middle trophic levels (fish and macroinvertebrates), and individual-based models for largeconsumers. ATLSS requires hydrologic input

Jon C. Cline; Jerome J. Lorenz; Eric D. Swain

2004-01-01

268

Modeling hydrologic processes at different scales - difficulties and possible solutions  

NASA Astrophysics Data System (ADS)

Geoscientists face a host of well-known problems when attempting to model physical processes at different scales. As scale increases, the spatial and temporal resolution of the available data generally decrease and the ratio of the area over which the predictions apply to that for which ground-truthing data is available skyrockets. From our perspective, a primary problem is that with the availability of satellite remote sensing data, the scale at which geophysical models could be applied leapfrogged way beyond our ability to provide matching field-based data. Efforts to improve satellite-based remote sensing systems should therefore be accompanied by detailed studies of the physical controls on the spatial variability of various ecosystem processes, primarily through large-scale field studies combined with low-altitude, as well as high-altitude, remote sensing data. As an introduction to how these, and other, problems can artificially limit the value of remote sensing and other large-scale data sets, we illustrate how these issues have affected a variety of hydrological problems of interest to the Geoscience Research group at the Idaho National Laboratory, including estimation of infiltration rates for large-scale groundwater flow models and examination of the climatic sensitivity of alpine glaciers and basin-scale water balance. The lessons learned in dealing with such problems speak to some of the work that must be done to facilitate application of remote sensing data to a wider variety of geophysical problems. Finally, we propose that modeling studies at a variety of scales would be more useful to society through implementation of what we term the automated modeling-monitoring feedback loop, in which numerical models with simplified interfaces are coupled with environmental monitoring systems to permit manipulation by non-modelers, and which could thereby permit continued calibration as new monitoring data are obtained.

Plummer, M. A.

2005-12-01

269

Coupling Hydrological Processes with the TRIPLEX Modeling System. Part I: Model Implementation and Sensitivity Analysis  

NASA Astrophysics Data System (ADS)

Understanding the carbon dynamics of the boreal forests often relies on the understanding the hydrological processes. The TRIPLEX Model incorporates several fundamental submodels that describe the water, nutrients and plant biomass relationships in forest ecosystems. To simulate hydrological processes, water balance and their interactions with carbon dynamics is a desirable step in designing projects in or near forested wetlands by using the TRIPLEX model. The purpose of this research was to develop a submodel for the TRIPLEX1.0 model system to simulate hydrological processes, hydroperiods and wetland interactions with aquifers. This submodel is capable of simulating flow routing, export and import of water, and evapotranspiration from forested wetlands for different hydroperiods. The model calculates a water balance based on precipitation, snowmelt, evaporation and transpiration from the forest canopy, evaporation from the understory and soil, surface runoff, water infiltration, diffusion, bypass flow, drainage and subsurface flow on a daily time-step. The ground water flow model was used to reproduce the surface water flow process through wetlands, and then to estimate new flow rates and values. The results are used to explore the interaction between water table positions, vertical soil moisture fluxes using by TRIPLEX to simulate carbon dynamics. The response and sensitivity of hydrology and soil carbon predictions to changes in model inputs, using both univariate and simultaneous changes in multivariable were examined in this study.

Cui, J.; Peng, C.; Zhou, X.; Hua, D.; Dang, Q.

2004-05-01

270

Continuous Hydrological Simulations with the NCUDWM Distributed Watershed Model  

NASA Astrophysics Data System (ADS)

The object of this study is to investigate the responses with which temporal resolutions of rainfall inputs shape the character of continuous hydrological simulations of distributed watershed models. A fully distributed watershed model, NCUDWM, has been developed for resolving watershed hydrological responses in a variety of spatial and temporal scales. The model interactively coupled three modules of 1-D river flow, 2-D surface runoff, and 3-D variable-saturated subsurface flow. The river flow is simulated by the 1-D diffusive wave approach for each river segment with the conservation of mass and the continuity of stage for river junctions. The surface runoff is simulated by the 2-D diffusive wave approach and eight flow directions are allowed for runoff in/out of each surface grid. The interactions between river flow and surface runoff is determined by the continuity of stage and the conservation of mass when water of two regimes are connected and stage differences exist. Daily evapotranspiration is estimated by multiplying the potential evapotranspiration, either prescribed or computed, by the crop coefficient determined from land use. The subsurface flow is a quasi 3-D approach, including soil moisture movements in the vertical direction and groundwater flows in the horizontal direction described by the Darcy’s law. The interactions between subsurface water and surface water (river and surface runoff) is described by the direct connection approach that flux and head continuities are conserved. This study examines hourly and daily flow simulations by NCUDWM with observed daily precipitations embedded with hourly precipitations for extreme events. The study site is the Shihmen Reservoir watershed (catchment area: 736 km2; elevations: 135-3529 m) in northern Taiwan and a yearly long simulation was performed for 2001. The first run was performed by merely providing daily precipitations in 2001. The second run was conducted by considering hourly precipitations of three typhoons making landfalls in Sept.-Oct. which account for more than 40% of annual precipitation. Preliminary results show that: (a) discrepancies of total runoff depths between two runs, for both yearly scale and discrete extreme events, are not significant as performed by the NCUDWM; (b) the first run is unable to resolve peak flows and peak discharge time down to hourly scale as a result of lacking finer temporal resolutions of rainfall input; and (c) in view of capturing daily discharges in continuous simulations as performed by the NCUDWM, hourly resolution of rainfall input is optional.

Sung, R.; Li, M.

2009-12-01

271

Remotely Sensed Potential Evaporation Estimates for Hydrologic Modeling  

NASA Astrophysics Data System (ADS)

This study explores a methodology solely dependent on remote sensing information to capture both the current climate signal and the spatial variability of daily potential evaporation (PE) by taking advantage of the new generation of Earth Observation satellites (i.e., MODIS sensor). PE, a required input for most hydrologic models, is typically obtained from pan evaporation estimates, or in some cases, from ground-based meteorological measurements at limited point locations. We focus our efforts on development of a "stand-alone" method to derive daily estimates of PE without the need for ground-based observations. The procedure is based on the Priestley-Taylor equation, incorporating a previously developed daily net radiation model during cloudless days. We then apply a simple algorithm using theoretical clear-sky net radiation and potential evaporation (linearly interpolated values during clear days), along with a daily cloud fraction to estimate net radiation and potential evaporation under cloudy conditions. For initial validation, point scale comparisons are undertaken using the single pixel value from MODIS corresponding to four ground-based observation sites covering a range of hydroclimatic conditions and biomes: Bondville (IL), Goodwin Creek (MS), Audubon (AZ) and Westville (OK). Preliminary results over a several year period (2001-2004) at three of the sites (Bondville, Goodwin Creek and Westville) show good correlation (R=0.875) and bias (0.227mm/day) at the daily time step. Results are further improved when aggregated to the monthly timescale (R=0.953, bias=0.197 mm/day). Performance at the Audubon site (semi-arid biome) is less satisfactory (R=0.820 and bias=2.025 mm/day at the daily time step). However, results are extremely promising and show the potential for application to hydrologic modeling and water-balance studies in both gauged and un-gauged basins. Further work is on-going to investigate deficiencies in semi-arid regions and to improve estimates under cloudy conditions.

Kim, J.; Hogue, T.

2006-12-01

272

Pitfalls and improvements in the joint inference of heteroscedasticity and autocorrelation in hydrological model calibration  

NASA Astrophysics Data System (ADS)

Residual errors of hydrological models are usually both heteroscedastic and autocorrelated. However, only a few studies have attempted to explicitly include these two statistical properties into the residual error model and jointly infer them with the hydrological model parameters. This technical note shows that applying autoregressive error models to raw heteroscedastic residuals, as done in some recent studies, can lead to unstable error models with poor predictive performance. This instability can be avoided by applying the autoregressive process to standardized residuals. The theoretical analysis is supported by empirical findings in three hydrologically distinct catchments. The case studies also highlight strong interactions between the parameters of autoregressive residual error models and the water balance parameters of the hydrological model.

Evin, Guillaume; Kavetski, Dmitri; Thyer, Mark; Kuczera, George

2013-07-01

273

Implications of radar rainfall estimates uncertainty on distributed hydrological model predictions  

NASA Astrophysics Data System (ADS)

Real time availability and high space-time resolution of radar based quantitative precipitation estimates (QPE) are appealing features for spatially detailed hydrological prediction and forecasting applications using distributed hydrological models. However, the data obtained remain an important source of uncertainty for hydrological predictions. Insight into the characteristics of this uncertainty is still limited and its quantification is a challenging task. This work studies the characteristics of radar QPE uncertainties and its implications on both hydrological modelling results and hydrological model parameter estimates. The uncertainty of a real time radar QPE product available in 10 minute intervals on a 1 km 2 grid is quantified by comparison to a reference precipitation field, which includes additional observations from rain gauge records. Based on this analysis a probabilistic model is proposed that describes the uncertainty structure of the radar QPE field. An ensemble of precipitation fields is generated that represents a quantitative estimate of radar QPE uncertainty from the sampling of the probabilistic model. On this basis the implications of radar QPE uncertainty on distributed hydrological model predictions are studied. The methodology proposed is applied to a real-world case study using the river basin of the Besòs in Spain as a test bed. The feasibility of the approach to condense the knowledge about radar QPE uncertainty in a probabilistic model and to map this uncertainty to the response of a hydrological model using an ensemble of precipitation fields is demonstrated. The results show that the probabilistic use of radar QPE may add valuable information to hydrological predictions and may reduce the bias of hydrological model parameter estimates.

Schröter, Kai; Llort, Xavier; Velasco-Forero, Carlos; Ostrowski, Manfred; Sempere-Torres, Daniel

2011-05-01

274

Exploiting remote sensing land surface temperature in distributed hydrological modelling: the example of the Continuum model  

NASA Astrophysics Data System (ADS)

Full process description and distributed hydrological models are very useful tools in hydrology as they can be applied in different contexts and for a wide range of aims such as flood and drought forecasting, water management, and prediction of impact on the hydrologic cycle due to natural and human-induced changes. Since they must mimic a variety of physical processes, they can be very complex and with a high degree of parameterization. This complexity can be increased by necessity of augmenting the number of observable state variables in order to improve model validation or to allow data assimilation. In this work a model, aiming at balancing the need to reproduce the physical processes with the practical goal of avoiding over-parameterization, is presented. The model is designed to be implemented in different contexts with a special focus on data-scarce environments, e.g. with no streamflow data. All the main hydrological phenomena are modelled in a distributed way. Mass and energy balance are solved explicitly. Land surface temperature (LST), which is particularly suited to being extensively observed and assimilated, is an explicit state variable. A performance evaluation, based on both traditional and satellite derived data, is presented with a specific reference to the application in an Italian catchment. The model has been firstly calibrated and validated following a standard approach based on streamflow data. The capability of the model in reproducing both the streamflow measurements and the land surface temperature from satellites has been investigated. The model has been then calibrated using satellite data and geomorphologic characteristics of the basin in order to test its application on a basin where standard hydrologic observations (e.g. streamflow data) are not available. The results have been compared with those obtained by the standard calibration strategy based on streamflow data.

Silvestro, F.; Gabellani, S.; Delogu, F.; Rudari, R.; Boni, G.

2013-01-01

275

An urban hydrological model with high spatial resolution rainfall from a meteorological model  

Microsoft Academic Search

The feasibility of a theoretical description of the urban water cycle by means of physically based models has been presented. A high-resolution three-dimensional finite-difference storm model was used to simulate convective rainfall over an urban catchment near Paris. A hydrological model described the surface processes as well as the discharge processes in the sewer system. The comparison of model results

J. Thielen; J.-D. Creutin

1997-01-01

276

Sensitivity of an ecological model to soil moisture simulations from two different hydrological models  

Microsoft Academic Search

Summary  Although advanced land surface schemes have been developed in the past decade, many biosphere models still use the simple\\u000a bucket model, partly due to its efficiency when it is coupled with an CGCM model. In this paper, we use a sophisticated land\\u000a surface model, the Simulator for Hydrology and Energy Exchange at the Land Surface (SHEELS), including an explicit vegetation

D. Ren; L. M. Leslie; D. J. Karoly

2008-01-01

277

An Open Source modular platform for hydrological model implementation  

NASA Astrophysics Data System (ADS)

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

Kolberg, Sjur; Bruland, Oddbjørn

2010-05-01

278

Impact of modellers' decisions on hydrological a priori predictions  

NASA Astrophysics Data System (ADS)

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), and (iii) that added process understanding can be as efficient as adding data for improving parameters needed to satisfy model requirements.

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

279

Modeling Nitrogen Leaching With A Biogeochemical Model Coupled With Soil Hydrology Model  

NASA Astrophysics Data System (ADS)

Land use changes for cropland, excessive application of fertilizers in agriculture, and increase in anthropogenic activities such as fossil fuel burning have lead to widespread increases in anthropogenic production of reactive N and NH3 emissions, and N deposition rates. An important consequence of these processes is intensification of soil nutrient leaching activities, leading to serious ground water contamination problems. The current study focuses on the issue of nitrogen (nitrate and ammonium) leaching due to land cover changes for cropland, excess N fertilizer application, and atmospheric nitrogen deposition on nitrogen leaching at a global scale. Simulations of nitrogen leaching require integration of processes involving soil hydrology and biogeochemical cycles. An existing terrestrial coupled carbon-nitrogen cycle model, Integrated Science Assessment Model (ISAM), was used to estimate nitrogen leaching. The N-cycle in ISAM includes the major processes associated with nitrogen (immobilization, mineralization, nitrification, denitrification, leaching, nitrogen fixation, and vegetation nitrogen uptake). ISAM also considers how carbon and nitrogen dynamics are influenced by the effects of human perturbations to the N cycle including atmospheric deposition and fertilizer application, and the fate of N in land use activities, i.e., deforestation and agricultural harvest. In this study, the ISAM soil hydrology was extended and improved with CLM 3.5 hydrology processes and algorithms, which extended the modeling capabilities to consider the prediction of nitrogen leaching. The model performance was evaluated with flow and nutrient data at several locations within the Upper Sangamon River Basin in Illinois, and flow data in contrasting watersheds in Oklahoma. This talk will focus on describing the results of a series of modeling experiments examining the influence of land management changes for cropland and nitrogen deposition on nitrogen leaching at a global scale. These experiments were conducted based on the measured activities of land use and nitrogen deposition over the last century.

Barman, R.; Yang, X.; Jain, A.; Post, W. M.; Sivapalan, M.

2008-12-01

280

A coupled mechanical/hydrologic model for WIPP shaft seals  

SciTech Connect

Effective sealing of the Waste Isolation Pilot Plant (WIPP) shafts will be required to isolate defense-generated transuranic wastes from the accessible environment. Shafts penetrate water-bearing hard rock formations before entering a massive creeping-salt formation (Salado) where the WIPP is located. Short and long-term seals are planned for the shafts. Short-term seals, a composite of concrete and bentonite, will primarily be located in the hard rock formations separating the water-bearing zones from the Salado Formation. These seals will limit water flow to the underlying long-term seals in the Salado. The long-term seals will consist of lengthly segments of initially unsaturated crushed salt. Creep closure of the shaft will consolidate unsaturated crushed salt, thereby reducing its permeability. However, water passing through the upper short-term seals and brine inherent to the salt host rock itself will eventually saturate the crushed salt and consolidation could be inhibited. Before saturating, portions of the crushed salt in the shafts are expected to consolidate to a permeability equivalent to the salt host rock, thereby effectively isolating the waste from the overlying water-bearing formations. A phenomenological model is developed for the coupled mechanical/hydrologic behavior of sealed WIPP shafts. The model couples creep closure of the shaft, crushed salt consolidation, and the associated reduction in permeability with Darcy's law for saturated fluid flow to predict the overall permeability of the shaft seal system with time. 17 refs., 6 figs., 1 tab.

Ehgartner, B.

1991-06-01

281

HBV and HCV Therapy  

PubMed Central

One year of interferon therapy inhibits HBV replication in one third of the patients whereas long-term administration of oral nucleos(t)ide analogues is efficient in most of them, as long as early treatment adaptation in patients with partial virological response and resistance is provided. Following the demonstration of a more potent antiviral effect in terms of sustained virological response (SVR) rates, Pegylated-IFN coupled with Ribavirin has become the standard treatment for chronic hepatitis C, with nearly 65% of all treated patients achieving a SVR. Long-term suppression of HBV and eradication of HCV would halt the progression of chronic hepatitis to cirrhosis, hepatocellular carcinoma and liver decompensation.

Lampertico, Pietro; Aghemo, Alessio; Vigano, Mauro; Colombo, Massimo

2009-01-01

282

Use of a Watershed-Modeling Approach to Assess Hydrologic Effects of Urbanization, North Fork Pheasant Branch Basinnear, Middleton, Wisconsin.  

National Technical Information Service (NTIS)

This report details a rainfall-runoff model that encompasses all elements of the hydrologic cycle including rainfall, snowmelt, evapotranspiration, interflow, streamflow, base flow, and ground -water recharge. The entire hydrologic system was characterize...

J. J. Steuer R. J. Hunt

2001-01-01

283

Modeling Links Between Hydrology and Non Point Source Pollution in a Data Scarce Environment, Inner Mongolia, China  

Microsoft Academic Search

Hydrological behavior is a central factor in deciding the fate of agricultural pollutants, yet the exact functions of hydrology and the scales at which they are most important are understudied. A physically based hydrological model was developed to examine the transport of common agricultural pollutants (nitrogen, phosphorus, pesticides) and problems of soil salinity. This model looks to uncover the effects

B. R. Runkle; X. Liang; F. Hao

2005-01-01

284

Virtual Hydrologic Environment (VHE) - Design and implementation of a GIS data model for the integration with hydrologic modeling and its application to Meijiang watershed area in East China  

NASA Astrophysics Data System (ADS)

Virtual Hydrologic Environment (VHE) is an integrated approach where two major data systems are included: integration of different types of GIS and water resources data, integration of data and modeling. The Unified Modeling Language (UML) facilitates the design of GIS based relational database model GeoHydro/DataBase(GH/DB) and is used to create a specialized set of geo- and hydro-objects from both surface and subsurface hydrology in a consistent manner. Feather classes were created to store spatial data, such as sub-catchments and steam network. Tables were created to store time series and other parameters. Relationship classes were developed to link related objects. Furthermore, a graphical user interface is implemented as a link between object- and process-oriented numerical model GeoSys/RockFlow and GH/DB for the pre- and post-processing of model data and parameters. This VHE concept is applied to the Meijiang watershed area which belongs to the Poyang lake basin, the biggest freshwater drainage area in East China. A coupled regional hydrologic soil model is developed for the understanding of surface/subsurface water interaction. The GH/DB has been populated with data from the Meijiang site. The soil compartment is directly coupled to the atmosphere via the land surface and to the aquifers. The high-resolution modeling is achieved by parallel computation techniques. VHE as a bridge between surface and subsurface hydrology can improve our understanding of the hydrologic cycle, the interactions between water, earth, ecosystems and man and its role in the context of climate change. The integration of databases and modeling by the use of methods from scientific computing and information technology leads to a comprehensive and consistent representation of the VHE and thus enhances our understanding about the interactions and coupling processes between the different compartments of the hydrologic system.

Chen, C.; Sun, F.; Lai, G. Y.; Kalbacher, T.; Kolditz, O.

2009-04-01

285

Improved process representation in a global hydrological model by calibration with GRACE gravity data  

NASA Astrophysics Data System (ADS)

Global data of temporal water storage variations are derived from monthly gravity measurements of the GRACE (Gravity Recovery And Climate Experiment) satellite mission, which completes its seventh year of operation (2002-2009). Therefore, GRACE provides a valuable input for validation and calibration of large-scale hydrological models. In this study, we present a technique to apply GRACE data for the parameter tuning of a global hydrological model, the WaterGAP Global Hydrology Model (WGHM). An efficient multi-objective calibration framework was developed to constrain model predictions by both measured river discharge and water storage variations from GRACE. Model calibration was done for WGHM for the 22 largest river basins worldwide. It is shown that the approach leads to improved simulation results with regard to both objectives, e.g. for the Amazon, Mississippi and Congo. From the multi-objective approach we gain more reliable and consistent simulations of water storage variations within the continental water cycle and detect possible model structure errors or mis-modeled processes for specific river basins. These results lead to an improved understanding of hydrological processes and their representation in the global model. Finally, we analyze the robustness of our results with respect to GRACE measurement errors, uncertainties from different gravity solutions and different filter techniques. Our results highlight the valuable nature of GRACE data when merged into large-scale hydrological modeling and depict methods to improve large-scale hydrological models.

Werth, S.; Güntner, A.

2009-04-01

286

A distributed monthly hydrological model for integrating spatial variations of basin topography and rainfall  

Microsoft Academic Search

Hydrological models at a monthly time-scale are important tools for hydrological analysis, such as in impact assessment of climate change and regional water resources planning. Traditionally, monthly models adopt a conceptual, lumped-parameter approach and cannot account for spatial variations of basin characteristics and climatic inputs. A large requirement for data often severely limits the utility of physically based, distributed-parameter models.

Xi Chen; Yongqin David Chen; Chong-Yu Xu

2007-01-01

287

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

Microsoft Academic Search

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

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

1998-01-01

288

A framework to assess the realism of model structures using hydrological signatures  

NASA Astrophysics Data System (ADS)

The use of flexible hydrological model structures for hypothesis testing requires an objective and diagnostic method to identify whether a rainfall-runoff model structure is suitable for a certain catchment. To determine if a model structure is realistic, i.e. if it captures the relevant runoff processes, both performance and consistency are important. We define performance as the ability of a model structure to mimic a specific part of the hydrological behaviour in a specific catchment. This can be assessed based on evaluation criteria, such as the goodness of fit of specific hydrological signatures obtained from hydrological data. Consistency is defined as the ability of a model structure to adequately reproduce several hydrological signatures simultaneously while using the same set of parameter values. In this paper we describe and demonstrate a new evaluation Framework for Assessing the Realism of Model structures (FARM). The evaluation framework tests for both performance and consistency using a principal component analysis on a range of evaluation criteria, all emphasizing different hydrological behaviour. The utility of this evaluation framework is demonstrated in a case study of two small headwater catchments (Maimai, New Zealand, and Wollefsbach, Luxembourg). Eight different hydrological signatures and eleven model structures have been used for this study. The results suggest that some model structures may reveal the same degree of performance for selected evaluation criteria while showing differences in consistency. The results also show that some model structures have a higher performance and consistency than others. The principal component analysis in combination with several hydrological signatures is shown to be useful to visualise the performance and consistency of a model structure for the study catchments. With this framework performance and consistency are evaluated to identify which model structure suits a catchment better compared to other model structures. Until now the framework has only been based on a qualitative analysis and not yet on a quantitative analysis.

Euser, T.; Winsemius, H. C.; Hrachowitz, M.; Fenicia, F.; Uhlenbrook, S.; Savenije, H. H. G.

2013-05-01

289

A framework to assess the realism of model structures using hydrological signatures  

NASA Astrophysics Data System (ADS)

The use of flexible hydrological model structures for hypothesis testing requires an objective and diagnostic method to identify whether a rainfall-runoff model structure is suitable for a certain catchment. To determine if a model structure is realistic, i.e. if it captures the relevant runoff processes, both performance and consistency are important. Performance describes the ability of a model structure to mimic a specific part of the hydrological behaviour in a specific catchment. This can be assessed based on evaluation criteria, such as the goodness of fit of specific hydrological signatures obtained from hydrological data. Consistency describes the ability of a model structure to adequately reproduce several hydrological signatures simultaneously, while using the same set of parameter values. In this paper we describe and demonstrate a new evaluation Framework for Assessing the Realism of Model structures (FARM). The evaluation framework tests for both performance and consistency using a principal component analysis on a range of evaluation criteria, all emphasizing different hydrological behaviour. The utility of this evaluation framework is demonstrated in a case study of two small headwater catchments (Maimai, New Zealand and Wollefsbach, Luxembourg). Eight different hydrological signatures and eleven model structures have been used for this study. The results suggest that some model structures may reveal the same degree of performance for selected evaluation criteria, while showing differences in consistency. The results also show that some model structures have a higher performance and consistency than others. The principal component analysis in combination with several hydrological signatures is shown to be useful to visualize the performance and consistency of a model structure for the study catchments. With this framework performance and consistency can be tested to identify which model structures suit a catchment better than other model structures.

Euser, T.; Winsemius, H. C.; Hrachowitz, M.; Fenicia, F.; Uhlenbrook, S.; Savenije, H. H. G.

2012-11-01

290

Integrated hydrologic modeling: Effects of spatial scale, discretization and initialization  

NASA Astrophysics Data System (ADS)

Groundwater discharge contributes significantly to the annual flows of Chesapeake Bay tributaries and is presumed to contribute to the observed lag time between the implementation of management actions and the environmental response in the Chesapeake Bay. To investigate groundwater fluxes and flow paths and interaction with surface flow, we have developed a fully distributed integrated hydrologic model of the Chesapeake Bay Watershed using ParFlow. Here we present a comparison of model spatial resolution and initialization methods. We have studied the effect of horizontal discretization on overland flow processes at a range of scales. Three nested model domains have been considered: the Monocacy watershed (5600 sq. km), the Potomac watershed (92000 sq. km) and the Chesapeake Bay watershed (400,000 sq. km). Models with homogeneous subsurface and topographically-derived slopes were evaluated at 500-m, 1000-m, 2000-m, and 4000-m grid resolutions. Land surface slopes were derived from resampled DEMs and corrected using stream networks. Simulation results show that the overland flow processes are reasonably well represented with a resolution up to 2000 m. We observe that the effects of horizontal resolution dissipate with larger scale models. Using a homogeneous model that includes subsurface and surface terrain characteristics, we have evaluated various initialization methods for the integrated Monocacy watershed model. This model used several options for water table depths and two rainfall forcing methods including (1) a synthetic rainfall-recession cycle corresponding to the region's average annual rainfall rate, and (2) an initial shut-off of rainfall forcing followed by a rainfall-recession cycling. Results show the dominance of groundwater generated runoff during a first phase of the simulation followed by a convergence towards more balanced runoff generation mechanisms. We observe that the influence of groundwater runoff increases in dissected relief areas characterized by high slope magnitudes. This is due to the increase in initial water table gradients in these regions. As a result, in the domain conditions for this study, an initial shut-off of rainfall forcing proved to be the more efficient initialization method. The initialized model is then coupled with a Land Surface Model (CLM). Ongoing work includes coupling a heterogeneous subsurface field with spatially variable meteorological forcing using the National Land Data Assimilation System (NLDAS) data products. Seasonal trends of groundwater levels for current and pre-development conditions of the basin will be compared.

Seck, A.; Welty, C.; Maxwell, R. M.

2011-12-01

291

Using the object modeling system for hydrological model development and application  

NASA Astrophysics Data System (ADS)

State of the art challenges in sustainable management of water resources have created demand for integrated, flexible and easy to use hydrological models which are able to simulate the quantitative and qualitative aspects of the hydrological cycle with a sufficient degree of certainty. Existing models which have been de-veloped to fit these needs are often constrained to specific scales or purposes and thus can not be easily adapted to meet different challenges. As a solution for flexible and modularised model development and application, the Object Modeling System (OMS) has been developed in a joint approach by the USDA-ARS, GPSRU (Fort Collins, CO, USA), USGS (Denver, CO, USA), and the FSU (Jena, Germany). The OMS provides a modern modelling framework which allows the implementation of single process components to be compiled and applied as custom tailored model assemblies. This paper describes basic principles of the OMS and its main components and explains in more detail how the problems during coupling of models or model components are solved inside the system. It highlights the integration of different spatial and temporal scales by their representation as spatial modelling entities embedded into time compound components. As an exam-ple the implementation of the hydrological model J2000 is discussed.

Kralisch, S.; Krause, P.; David, O.

2005-08-01

292

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

USGS Publications Warehouse

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.

Milly, Paul C.; Dunne, Krista A.

2011-01-01

293

Mapping impervious surface change from remote sensing for hydrological modeling  

NASA Astrophysics Data System (ADS)

This paper describes a method to estimate changes in impervious surface fraction from widely available medium resolution remote sensing data. The potential of the impervious surface fraction data for hydrological modeling is illustrated by a case study for the Kleine Nete catchment, Belgium. Impervious surface fraction data for the Kleine Nete were simulated based on a Landsat TM image acquired in 1986 and a Landsat ETM+ of 2003. The paper assesses the impact of change in impervious surface cover between 1986 and 2003 on the vertical water balance and groundwater system. The results show that impervious surface fractions can be obtained from medium resolution remote sensing data with reasonable accuracy, the mean average error is around 18% and the bias close to zero for both the recent and historical image. Comparing the impervious surface fractions of 1986 and 2003 indicates that most urbanization occurred by densification of existing urban areas. The average impervious fraction of the urban cells increases from 25.4% to 29.2% between 1986 and 2003. Urban runoff increases by 9.5% between 1986 and 2003 due to the increase in impervious surfaces, while the evapotranspiration and recharge in urban areas decrease by 1.5% and 1.6% respectively. For the study area a land-use class based parameterization method underestimates groundwater recharge and head decreases in the most dense urban area and overestimates those in some of the smaller urban centers.

Dams, J.; Dujardin, J.; Reggers, R.; Bashir, I.; Canters, F.; Batelaan, O.

2013-04-01

294

Remote sensing and hydrological modeling of burn scars  

NASA Astrophysics Data System (ADS)

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 will be used for planning pre-fire fuel reduction treatments.

Miller, Mary Ellen

295

Effects of differently interpolated observational precipitation data on hydrological modeling  

NASA Astrophysics Data System (ADS)

For realistic water balance modeling on a local or regional scale, meteorological forcing of the highest possible spatial resolution is required. In this project, the water balances for medium sized catchments (65 - 362 km²) in Rhineland-Palatinate (RLP, Germany) are simulated. Two different data sets of precipitation with high spatial and adequate temporal resolution exist for the domain and the period 1993 - 2000. One originates from the German Weather Service (DWD), the second from the state office for environment, water and factory inspectorate Rhineland-Palatinate (LUWG). Both datasets have a spatial resolution of 1km x 1km, the dataset of the DWD a daily and the LUWG dataset an hourly temporal resolution. A comparison of both datasets regarding precipitation sums on a daily, monthly and yearly temporal scale is done for the area mean of the catchment as well as for single grid cells to specify the differences between both datasets. Furthermore, the spatial patterns of interpolated precipitation are analyzed in both datasets. The analysis of both datasets shows large differences. These differences are mainly due to different interpolation schemes and a partially different data base. There is a not acceptable deviation in the area mean of the yearly precipitation sum for the catchment of up to 241 mm/year (DWD: 807 mm/year ; LUWG: 566 mm/year); in single grid cells, the differences even reach up to 430 mm/year. Different precipitation input fields also result in different hydrological outputs. So, in order to precisely assess the effects on water balance modeling, the water budget model LARSIM, which was calibrated using the LUWG dataset, was run with both datasets. The output variables are compared on several temporal scales for subcatchments and the whole domain. For the analysis of runoff variables, signature indices are used. Total runoff as well as e.g. the runoff coefficient is higher for the "wetter" dataset.

Casper, Markus C.; Reiter, Philipp; Gronz, Oliver; Gutjahr, Oliver; Heinemann, Günther; Wittig, Marlen

2013-04-01

296

Constraining Parameters of a Distributed Hydrologic Model Using Both Apriori Information and Optimization  

NASA Astrophysics Data System (ADS)

Automatic calibration of distributed hydrologic models is complicated by the high dimensionality of the parameter space and uncertainties arising from various sources. Spatial organization of hydrologically important watershed characteristics can be used to constrain (and therefore reduce) the dimension of the parameter space. The National Weather Service has developed an apriori parameter estimation framework for the distributed Sacramento Soil Moisture Model, based on the STATSGO Soil Database. Using this approach as a baseline, several model calibration strategies (incorporating uncertainty) were explored, including 1) optimization of apriori parameter multipliers, and 2) penalizing deviations from the apriori parameter values. An important implication of basing the derived hydrologic model parameters on soil hydraulic property data is that, uncertainties in the soil hydraulic parameters will be reflected in the hydrologic parameter estimates. The consequences of these uncertainties will be analyzed, and results for several operational basins will be presented and discussed.

Yilmaz, K. K.; Gupta, H. V.; Wagener, T.

2005-12-01

297

Implementation and Validation of Improved Landsurface Hydrology in an Atmospheric General Circulation Model.  

National Technical Information Service (NTIS)

Landsurface hydrological parameterizations are implemented in the NASA Goddard Institute for Space Studies (GISS) General Circulation Model (GCM). These parameterizations are: (1) runoff and evapotranspiration functions that include the effects of subgrid...

K. D. Johnson D. Entekhabi P. S. Eagleson

1991-01-01

298

Hydrologic Modeling and Data Requirements for Analysis of Urban Streamflow Management Alternatives.  

National Technical Information Service (NTIS)

Continuous simulation hydrologic modeling is one approach to the incorporation of empirical knowledge of watershed dynamics into planning at the land development and total watershed levels for analyzing urban runoff strategies. In developing the use of th...

G. J. Kemp S. J. Burges

1978-01-01

299

Investigations of Sensitivity and Uncertainty in Some Hydrologic Models of Yucca Mountain and Vicinity.  

National Technical Information Service (NTIS)

The uncertainty in travel time for water through unsaturated and saturated zones of Yucca Mountain and vicinity was determined by considering uncertainty associated with input parameters to the hydrologic models of these zones. A first-order analysis was ...

E. A. Jacobson M. D. Freshley F. H. Dove

1985-01-01

300

Moving from field observations of catchment hydrologic connectivity to new modeling conceptualizations  

NASA Astrophysics Data System (ADS)

Hydrologic connectivity between catchment upland and near stream areas is essential for the transmission of water, solutes, and nutrients to streams. Not surprisingly, this topic has received widespread attention in recent years. While significant progress has been made in experimental hydrology to observe and quantify landscape scale hydrologic connectivity, new model conceptualizations based on these observations have lagged. While numerous models are able to recreate observed hydrographs at the catchment outlet, few are consistent with or comparable to internal catchment observations of hydrological processes. It is critical that experimental studies and model development and evaluation be accomplished in concert with one another. This call to action is not new, yet it is rarely pursued and accomplished. Here we present a new modeling framework that appropriately represents hydrologic patterns and drivers of connectivity at the catchment scale. More specifically, the distribution of upslope accumulated area (UAA) along the stream network is a template by which landscape-scale hydrologic connectivity and catchment runoff can be simulated. We applied the model to the Stringer Creek watershed of the Tenderfoot Creek Experimental Forest (TCEF), located in central Montana, USA. We independently tested model consistency with internal catchment behavior and field observations of shallow groundwater connectivity across 30 hillslope-riparian-stream transects (180 groundwater wells). This parsimonious model was able to represent streamflow dynamics well and more importantly was consistent with internal catchment observation of hydrological connectivity through space and time. This new model structure, informed by catchment structure and emergent patterns of hydrological processes, represents a realization of the promise of integrated field - model development.

McGlynn, B.; Marshall, L.; Jencso, K.; Smith, T.

2012-04-01

301

Assessing the model performance of snow water resources simulated by a coupled mesoscale atmospheric and hydrologic model  

NASA Astrophysics Data System (ADS)

Predicting snow water resources is a key functionality of atmospheric and hydrologic models. The verification of the performance can be done by comparing the model's output with snow ruler or snow water equivalent (SWE) observations. In the last years, snow covered area observations from optical satellite sensors have become a considerable extension to evaluate the snow extent. SWE observations derived from passive microwave satellite sensors are restricted to larger spatial scales. Despite these areal comparison techniques the evaluation of hydrologic models is traditionally carried out by assessing the performance of the simulated stream flow. The stream flow integrates all hydrological processes on catchment scale, which also includes snow accumulation and melt. A comparison of simulated and observed stream flow in order to verify the model is in general only subject to hydrologic models. In contrast, atmospheric models commonly represent the physics of snow dynamics in a more comprehensive way than hydrologic models do. This poster addresses the applicability of regional climate models (RCM) to predict the snow water storage within a catchment by comparing simulated and observed stream flow. The simulated stream flow is derived by using a hydrologic model which is driven by the atmospheric model. Meteorological fields simulated by WRF (Weather Research and Forecast model) including precipitation and SWE were converted to maps on an hourly time step. These maps were prepared as input boundary conditions for the hydrologic model Panta Rhei. In contrast to classic hydrologic simulations, the snow melt module was replaced by a distributed SWE boundary condition module, which allows hydrologic simulations with an external input of spatial and temporal SWE distributions. Since accumulation and melt is directly calculated by the RCM and other land surface hydrologic processes are simulated by the hydrologic model, the comparison of simulated and observed stream flow also enables the evaluation of the RCM's performance to predict the snow storage on catchment scale. The case of the winter 2005/06 accumulation and ablation season in the low mountain range catchment Sieber (44 km2) in northern Germany was studied. The study shows that WRF simulates the seasonal course of the SWE with good agreement compared to observations on the point scale. The simulated stream flow with a distinctive rain on snow event is reproduced reasonably well by the coupled modeling system. Hence, the study emphasizes the applicability of hydrologic models for verification studies of RCM in general. Furthermore, hydrologic models are useful tools to assess the performance of snow water resources predicted by RCM in particular. Since the coupled simulations only depend on global input data, the presented approach could be of some interest for the prediction of snow accumulation and melt in remote areas.

Förster, K.; Meon, G.

2012-04-01

302

Effects of sub-basin scale on runoff simulation in distributed hydrological model: BTOPMC  

Microsoft Academic Search

Scale problems result in uncertainty in hydrological modelling and is far from being solved. A distributed hydrological model BTOPMC (Block- wise use of TOPMODEL with Muskingum-Cunge method) analyses the effects of sub-basin scale on runoff in the Fuji-kawa and the Nakagawa basins in Japan. Study basins were subdivided into natural sub-basins using the Pfafstetter method. Results indicate that smaller average

TIANQI AO; JUNICH YOSHITANI; KUNIYOSHI TAKEUCHI; KAZUHIKO FUKAMI; TADASHI MUTSUURA; HIROSHI ISHIDAIRA

2003-01-01

303

Toward the application of the physically based distributed hydrological model BTOPMC to ungauged basins  

Microsoft Academic Search

For hydrological prediction and estimation in ungauged or data-poor basins, it is required that model parameters can be identified by using basin characteristics rather than calibrations. As the first step of exploring such a physically based identification method for the physically-based distributed hydrological model, BTOPMC (block-wise use of TOPMODEL with the Muskingum-Cunge method), preliminary studies on two aspects were carried

AO TIANQI; JUNICHI YOSHITANI; KUNIYOSHI TAKEUCHI; KAZUHIKO FUKAMI; TADASHI MUTSUURA; HIROSHI ISHIDAIRA

2007-01-01

304

A hillslope-based hydrological model using catchment area and width functions  

Microsoft Academic Search

A flow-interval hillslope discretization scheme is proposed for catchment hydrological modelling. By this scheme, a two-dimensiona l catchment is simplified into a one-dimensional cascade of flow intervals linked by the main stream. Each flow interval comprises a set of parallel hillslopes. The hillslope is the fundamental compu­ tational unit in the hydrological model providing lateral inflow to the main stream.

DAWEN YANG; SRIKANTHA HERATH; KATUMI MUSIAKE

2002-01-01

305

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

Microsoft Academic Search

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

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

306

A Distributed Hydrological model Forced by DIMP2 Data and the WRF Mesoscale model  

NASA Astrophysics Data System (ADS)

Forecasted warming over the next century will drastically reduce seasonal snowpack that provides 40% of the world’s drinking water. With increased climate warming, droughts may occur more frequently, which will increase society’s reliance on this same summer snowpack as a water supply. This study aims to reduce driving data errors that lead to poor simulations of snow ablation and accumulation, and streamflow. Results from the Distributed Hydrological Model Intercomparison Project Phase 2 (DMIP2) project using the Distributed Hydrology Soil and Vegetation Model (DHSVM) highlighted the critical need for accurate driving data that distributed models require. Currently, the meteorological driving data for distributed hydrological models commonly rely on interpolation techniques between a network of observational stations, as well as historical monthly means. This method is limited by two significant issues: snowpack is stored at high elevations, where interpolation techniques perform poorly due to sparse observations, and historic climatological means may be unsuitable in a changing climate. Mesoscale models may provide a physically-based approach to supplement surface observations over high-elevation terrain. Initial results have shown that while temperature lapse rates are well represented by multiple mesoscale models, significant precipitation biases are dependent on the particular model microphysics. We evaluate multiple methods of downscaling surface variables from the Weather and Research Forecasting (WRF) model that are then used to drive DHSVM over the North Fork American River basin in California. A comparison between each downscaled driving data set and paired DHSVM results to observations will determine how much improvement in simulated streamflow and snowpack are gained at the expense of each additional degree of downscaling. Our results from DMIP2 will be used as a benchmark for the best available DHSVM run using all available observational data. The findings presented here will help guide watershed managers of the requirements, advantages and limitations of using a distributed hydrological model coupled with various forms of forcing data over mountainous terrain.

Wayand, N. E.

2010-12-01

307

Using models for the optimization of hydrologic monitoring  

USGS Publications Warehouse

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 techniques briefly described earlier are described in detail in a U.S. Geological Survey Scientific Investigations Report available on the Internet (Fienen and others, 2010; http://pubs.usgs.gov/sir/2010/5159/). This fact sheet presents a synopsis of the techniques as applied to a synthetic model based on a model constructed using properties from the Lake Michigan Basin (Hoard, 2010).

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

2011-01-01

308

Determining the Hydrologic Impacts of Climate Variability on Florida's Everglades Through the Use of a Finite Volume Hydrologic Model  

NASA Astrophysics Data System (ADS)

A good understanding of climate variability and its impacts on the regional water budget are crucial for the restoration of Florida's Everglades. This is investigated by varying the two most sensitive climatic data sets, namely rainfall and evapotranspiration of a regional-scale hydrologic model. A 36-year long record, spanning from 1965 to 2000 is used in these assessments. Although not comprehensive, these data sets include several seasons with extremely high and low rainfall and evapotranspiration. The Everglades National Park, the Big Cypress National Preserve, and the Water Conservation Areas 3A and 3B are included in the study area. These watersheds jointly encompass an area of 10,158 square kilometers, and are home to many endangered and threatened species of fauna and flora. The Regional Simulation Model (RSM) developed by the South Florida Water Management District (SFWMD) is used in this study to evaluate and quantify the hydrologic responses caused due to climate variability. RSM is a finite-volume, regional-scale, distributed, continuous hydrologic model with fully coupled groundwater, canal and overland flow components. This model uses a variable triangular mesh that conforms to levees, canals and sub-basin boundaries. RSM can adequately simulate the low-relief topography, and high water tables, saturated hydraulic conductivities and surface roughnesses that exist in Florida's Everglades. The model uses the diffusive wave approximation of Saint-Venant's equation to simulate canal and overland flows. The Southern Everglades implementation of the RSM (hereafter, Southern Everglades Model or SEM) is calibrated and verified using stage data from 1988 to 1995, and 1996 to 2000, respectively. An irregular triangular mesh with 52,817 cells and a one-day time step are used in this implementation. For all simulations and assessments the model boundary conditions are obtained from the South Florida Water Management Model developed by the SFWMD. Two types of assessments are performed in order to evaluate the hydrologic impact of climate variability on Florida's Everglades. In the first assessment, SEM is run in continuous mode from 1965 to 2000. In the second assessment, SEM is run in position-analysis mode. In the position-analysis mode, all cell stages at the beginning of each simulation year are re-initialized with hydrologic conditions existing in the SEM model- domain on January 1, 2000. For both assessments, all calibrated data sets--with the exception of climatic data sets--are kept unchanged. The main objective of these assessments is to evaluate model predictions under varying climate and initial-condition scenarios. Consequently, the results presented in this study have very important implications for attaining short- and long-term water resources management and planning goals including eco-system restoration goals in Florida's Everglades.

Senarath, S. U.; Novoa, R. J.; Niedzialek, J. M.; Zheng, F.

2006-12-01

309

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

NASA Astrophysics Data System (ADS)

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.

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

2006-12-01

310

Numerical prediction of subsidence with coupled geomechanical-hydrological modeling  

SciTech Connect

A coupled finite element geomechanical-hydrology code is currently under development for application to the problem of predicting groundwater disturbances associated with mine subsidence. The structural-fluid coupling is addressed by calculating the subsided mine geometry, with emphasis placed on determining the strata disturbance and locating damaged regions, for input into a hydrology code, which determines localized volume flow rates and aquifer fluctuations. Benefits from coupling will be best realized when field measurements, an additional aspect of the study concurrent with analytical investigations, indicating the relationship between increasing rock strain and increasing permeability are incorporated into hydraulic material descriptions. Hydrologic and structural calculations are presented to demonstrate computational capabilities applicable to mine subsidence.

Girrens, S.P.; Anderson, C.A.; Bennett, J.G.; Kramer, M.

1981-01-01

311

Potent and persistent in vivo anti-HBV activity of chemically modified siRNAs  

Microsoft Academic Search

The efficacy of lipid-encapsulated, chemically modified short interfering RNA (siRNA) targeted to hepatitis B virus (HBV) was examined in an in vivo mouse model of HBV replication. Stabilized siRNA targeted to the HBV RNA was incorporated into a specialized liposome to form a stable nucleic-acid-lipid particle (SNALP) and administered by intravenous injection into mice carrying replicating HBV. The improved efficacy

Jennifer A Lockridge; Lucinda Shaw; Karin Blanchard; Kristi Jensen; Wendy Breen; Kimberly Hartsough; Lynn Machemer; Susan Radka; Vasant Jadhav; Narendra Vaish; Shawn Zinnen; Chandra Vargeese; Keith Bowman; Chris S Shaffer; Lloyd B Jeffs; Adam Judge; Ian MacLachlan; Barry Polisky; David V Morrissey

2005-01-01

312

Comparing tightly coupled and loosely coupled paradigms for modeling hydrologic systems  

NASA Astrophysics Data System (ADS)

Loosely coupled modeling architectures enable model developers to represent an environmental system by incorporating processes from multiple scientific disciplines. In contrast, models developed using the more common tightly coupled architecture approach maximize computational performance, but are more restrictive in how they allow modelers to incorporate processes not already implemented within that modeling framework. As the scope of hydrologic models continues to expand, loosely coupled modeling will become a more attractive option for representing complex hydrologic systems. Because loosely coupled modeling approaches have not been widely implemented within the hydrologic community, it is necessary to develop tests to ensure they produce accurate results and have similar performance metrics compared to tightly coupled models. For this reason, the objective of this study is to compare and contrast the process of implementing tightly-coupled and loosely-coupled models of hydrologic systems. The approach is to predict the streamflow from a precipitation event using the Hydrologic Engineering Center's (HEC) Hydrologic Modeling System (HMS) and custom programmed modeling components implemented using the Open Modeling Interface (OpenMI). Each of these two modeling approaches were set up to model the same event using the same process equations over the same spatial and temporal domains. The results showed that the OpenMI components can reproduce the solution of the tightly-coupled HEC-HMS model. There was minimal computational overhead introduced by the OpenMI component communication protocol. The results of this study suggest that loosely-coupled OpenMI components can be used in place of existing, tightly coupled models without compromising predictive accuracy or introducing restrictive computational demand. This work, however, was limited to a simple case study. Future work will be directed at expanding the example to more complex systems to understand how accuracy and performance are effected by model complexity.

Castronova, A. M.; Goodall, J. L.

2009-12-01

313

Development of An Integrated Hydrologic Model in Yolo County, California  

NASA Astrophysics Data System (ADS)

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

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

2006-12-01

314

Climate change impact on available water resources obtained using multiple global climate and hydrology models  

NASA Astrophysics Data System (ADS)

Climate change is expected to alter the hydrological cycle resulting in large-scale impacts on water availability. However, future climate change impact assessments are highly uncertain. For the first time, multiple global climate (three) and hydrological models (eight) were used to systematically assess the hydrological response to climate change and project the future state of global water resources. The results show a large spread in projected changes in water resources within the climate-hydrology modelling chain for some regions. They clearly demonstrate that climate models are not the only source of uncertainty for hydrological change. But there are also areas showing a robust change signal, such as at high latitudes and in some mid-latitude regions, where the models agree on the sign of projected hydrological changes, indicative of higher confidence. In many catchments an increase of available water resources is expected but there are some severe decreases in central and Southern Europe, the Middle East, the Mississippi river basin, Southern Africa, Southern China and south eastern Australia.

Hagemann, Stefan; Chen, Cui; Clark, Douglas B.; Folwell, Sonja; Gosling, Simon N.; Haddeland, Ingjerd; Hanasaki, Naota; Heinke, Jens; Ludwig, Fulco; Voss, Frank; Wiltshire, Andrew J.

2013-04-01

315

Climate change impact on available water resources obtained using multiple global climate and hydrology models  

NASA Astrophysics Data System (ADS)

Climate change is expected to alter the hydrological cycle resulting in large-scale impacts on water availability. However, future climate change impact assessments are highly uncertain. For the first time, multiple global climate (three) and hydrological models (eight) were used to systematically assess the hydrological response to climate change and project the future state of global water resources. The results show a large spread in projected changes in water resources within the climate-hydrology modelling chain for some regions. They clearly demonstrate that climate models are not the only source of uncertainty for hydrological change. But there are also areas showing a robust change signal, such as at high latitudes and in some mid-latitude regions, where the models agree on the sign of projected hydrological changes, indicative of higher confidence. In many catchments an increase of available water resources is expected but there are some severe decreases in central and Southern Europe, the Middle East, the Mississippi river basin, Southern Africa, Southern China and south eastern Australia.

Hagemann, S.; Chen, C.; Clark, D. B.; Folwell, S.; Gosling, S. N.; Haddeland, I.; Hanasaki, N.; Heinke, J.; Ludwig, F.; Voß, F.; Wiltshire, A. J.

2012-12-01

316

Using climate model ensemble forecasts for seasonal hydrologic prediction  

Microsoft Academic Search

Seasonal hydrologic forecasting has long played an invaluable role in the development and use of water resources. Despite notable advances in the science and practice of climate prediction, current approaches of hydrologists and water managers largely fail to incorporate seasonal climate forecast information that has become operationally available during the last decade. This study is motivated by the view that

Andrew Whitaker Wood

2003-01-01

317

Nonlinear models of temporal rainfall: Appropriateness and hydrologic relevance  

NASA Astrophysics Data System (ADS)

We examine the nonlinear structure of temporal rainfall at different scales, analyzing the behavior of such indicators as breakdown coefficients, run lengths, and statistical moments. It is shown that long-range correlations reveal an underlying nonlinearity, of a different nature at small scales and large scales, respectively. A hydrological integration and discussion of results is presented.

Fernandez-Yañez, Carlos Antonio; Carsteanu, Alin Andrei

2013-04-01

318

Hydrological model response to different estimations of rainfall inputs  

Microsoft Academic Search

In this paper we discuss the effects on simulated storm hydrographs when different estimations of rainfall fields are performed from a real storm by following the application of different techniques of precipitation estima- tion. The main objective of this work is to evaluate the hydrological response to changes in rainfall inputs due to different techniques in their estimation. In order

GRACIELA V. ZUCARELLI; EDUARDO B. CEIRANO; DANIEL F. BARRERA

319

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...

320

Scale and Resolution Relationships of Soils Information with Hydrology Modeling  

Microsoft Academic Search

Recent developments in digital soil mapping coupled with pedotransfer functions have improved significantly the ability of soil information to be provided quantitatively. This presents a challenge and an opportunity to understand the scale dependency of simulated hydrologic processes and their relation to the scale and spatial resolution of soil information. The objective of this research is to determine the sensitivity

Z. Libohova; P. Owens; L. C. Bowling; K. A. Cherkauer; B. S. Naz; E. H. Winzeler

2009-01-01

321

Parameter calibration of physically based distributed hydrological model: preliminary results with cases in Southern China  

NASA Astrophysics Data System (ADS)

Physically based distributed hydrological models are regarded to be able to derive model parameters from terrain properties such as elevation, soil type, land use, etc., but due to the lack of references and experiences in physically deriving model parameters, it is not an easy job to physically derive the parameters for physically based distributed hydrological models, so the authors think that it may be worth to explore the possibility and methodology to calibrate parameter of physically based distributed hydrological model. In this paper, the SCE-UA parameter calibration method is tested to calibrate the parameter of a physically based distributed hydrological model-the Liuxihe Model that was proposed by Yangbo Chen, et. al., and three small basins were used as the case studies. The preliminary results were compared with that with parameter adjusted manually, and it suggested that parameter calibration or adjusting could improve the model performance of physically based distributed hydrological model, but there are still some issued to be further studied, such as the computing efficiency when applying to larger basins, initial parameters, physical means of parameter, etc.

Xu, H.; Chen, Y.

2011-12-01

322

Further testing of the integrated hydrology model (InHM): multiple-species sediment transport  

Microsoft Academic Search

The sediment-transport version of the Integrated Hydrology Model (InHM) is further tested for the case of multiple-species sediment transport with both rainsplash and hydraulic erosion using data from the Johansen et al. (2001) field experiments. The ability to simulate sub-plot scale interactions between surface water hydrology and multiple-species sediment transport with InHM is clearly demonstrated. Sensitivity analysis reveals that the

Qihua Ran; Christopher S. Heppner; Joel E. VanderKwaak; Keith Loague

2007-01-01

323

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

Microsoft Academic Search

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

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

2010-01-01

324

Head-Dependent Flux Boundary Representation of Linear Hydrologic Features in Embedded Groundwater Flow Models  

Microsoft Academic Search

Linear hydrologic features such as rivers are important external stresses in groundwater flow systems that are implemented numerically as head-dependent flux boundaries. In MODFLOW, the USGS modular finite difference saturated groundwater flow model, information for cells designated as these types of boundaries are contained in input files, where the only spatial reference are the grid coordinates (Layer-Row-Column). Linear hydrologic spatial

R. D. Patterson

2001-01-01

325

Hydrologic Modelling of Modern and Ancient Rift Basin Lakes In Kenya  

Microsoft Academic Search

Hydrologic modelling of ancient lakes reconstructed from lacustrine sediments and ancient shorelines is a well-established tool for the assessment of climatic condi- tions in the past. In the Central Kenya Rift, well-dated sediments of two neighboring lake basins, the Naivasha and the Nakuru-Elmenteita basin, respectively, suggest syn- chronous hydrologic fluctuations during the last 150,000 years. In order to link these

A. G. N. Bergner; B. Bookhagen; M. Duehnforth; M. H. Trauth

2002-01-01

326

A conceptual model of volume-change controls on the hydrology of cutover peats  

Microsoft Academic Search

Modeling hydrological processes in certain peats requires a detailed understanding of short-term changes in soil volume and it's influence on the system's hydraulic properties. A study of cutover sites abandoned for 7-years (H92) and 2-years (H97), and an undisturbed section of the Lac Saint-Jean (LSJ) cutover bog was conducted to characterize peat volume changes and its associated hydrological behaviour. Shrinkage

G. W. Kennedya

327

On the effects of hydrological model structure on soil moisture data assimilation  

NASA Astrophysics Data System (ADS)

Nowadays, satellite sensors allow obtaining soil moisture estimates at global scale with an adequate temporal and spatial resolution, thereby offering a theoretical chance to improve flood-forecasting systems based on rainfall-runoff models. In fact, the knowledge of antecedent soil moisture conditions plays a crucial role in predicting catchment response to rainfall events. In the literature, several studies have focused on the assimilation of soil moisture data into hydrological models. The results of these studies tend to show that an improvement in discharge and soil moisture forecasts can be obtained when the assimilated information originates from accurate in situ measurements. When dealing with the assimilation of remote sensing-derived soil moisture data, the reported results are more controversial. There is no doubt that the performances of soil moisture data assimilation studies depend on many factors: data assimilation scheme, hydrological model structure, accuracy and resolution of soil moisture data. As of today, these dependences are not well understood and the disparity of outcomes in past studies arguably reflects the differences in the design of the experiments. In this general context, the aim of this study is to investigate the effects of hydrological model structures on soil moisture data assimilation performance. The analysis focuses on the vertical "stratification" of the soil column in a conceptual hydrological model. We consider multiple structures that differ by the number of soil reservoirs and their respective sizes. The recently introduced SUPERFLEX hydrological modelling framework is used to this end. In fact, this framework allows building and modifying multiple hydrological models by combining three basic building blocks: reservoirs, lag functions and junctions. As a data assimilation scheme, the particle filter was considered. The area of interest is the Alzette catchment (1200 km2), located in Luxembourg, while the analysed period spans from 2005 to 2011. The results of our study provide some insights on model structure requirements supporting an optimal usage of in situ measured and remotely sensed soil moisture data for operational hydrology.

Corato, Giovanni; Matgen, Patrick; Giustarini, Laura; Fenicia, Fabrizio

2013-04-01

328

Fine-Resolution Hydrologic Modeling of Semiarid River Basins: Preliminary Results from the Upper Rio Grande  

NASA Astrophysics Data System (ADS)

Water resources management and decision making in arid and semiarid regions require scientific knowledge and predictive capability of the physical processes occurring within hydrologic systems at scales sufficient to capture the variability inherent in the resource and its utilization. Our understanding of the interaction between water supply and demand is aided through numerical models that best represent our current knowledge of the hydrologic, ecological and meteorological processes in river basins. To this end, advances in distributed hydrologic modeling over large regional watersheds can aid in providing estimates of water availability and its susceptibility to climate variations, land-cover change and population growth. In this study, we utilize the TIN-based Real-time Integrated Basin Simulator (tRIBS) model to simulate continuous hydrological processes within subbasins of the Upper Río Grande in north-central New Mexico. First, we introduce the distributed model by highlighting the following salient features: (1) coupled unsaturated and saturated zones through a dynamic water table, (2) coupled energy and hydrologic balance at the land surface and (3) topographically-driven soil moisture redistribution, radiation and evapotranspiration. Accurate terrain representation at fine-resolution is achieved through the use of a triangulated irregular network (TIN) terrain model. Second, we present semiarid case studies in model setup, parameterization and continuous operation for the Upper Río Puerco and Jemez River. These river basins provide test cases for the calibration and validation of the tRIBS model through the use of in-situ measurement networks and long-term rainfall and stream gauging records. We will present the catchment hydrological response and its spatial organization by integrating geospatial data on topography, land-surface properties and precipitation obtained from geographic information systems, gauging networks and remote sensing. Although preliminary, our results indicate the potential for using fine-resolution hydrologic models over large semiarid regional watersheds such as the Upper Río Grande.

Wyckoff, R.; Vivoni, E. R.; Rinehart, A.

2004-12-01

329

Influence of chronic HBV infection on superimposed acute hepatitis E  

PubMed Central

AIM: To investigate the influence of chronic hepatitis B virus (HBV) infection [based on the status of hepatitis B e antigen (HBeAg), HBV DNA, and cirrhosis] on superimposed acute hepatitis E. METHODS: A total of 294 patients were recruited from the Department of Infectious Diseases of the Third Affiliated Hospital, Sun Yat-sen University, from January 2003 to January 2012. The patients were classified into two groups: an HBV + hepatitis E virus (HEV) group (a group with chronic HBV infection that was superinfected with acute hepatitis E, n = 118) and an HEV group (a group with acute hepatitis E, n = 176). We retrospectively analyzed and compared the clinical features of the two groups. Statistical analyses were performed using the ?2 test or Fisher’s exact test for categorical variables and the Student’s t test for continuous variables. A P value < 0.05 was considered statistically significant. RESULTS: The peak values of prothrombin time, serum total bilirubin, and Model for End-Stage Liver Disease scores were significantly higher in the HBV + HEV group. More patients in the HBV + HEV group had complications (39.8% vs 16.5%, P = 0.000) and developed liver failure (35.6% vs 8.5%, P = 0.000). Additionally, the mortality of the HBV + HEV group was significantly higher (20.3% vs 7.4%, P = 0.002). Further analysis of the HBV + HEV group showed that there were no significant differences in complication occurrence, liver failure incidence, or mortality between patients with different HBeAg and HBV DNA statuses. However, in patients with underlying cirrhosis, complication occurrence and liver failure incidence significantly increased. In total, 12.7% of the patients in the HBV + HEV group received anti-HBV treatment, but this therapy failed to reduce mortality in patients who developed liver failure. CONCLUSION: The presence of underlying cirrhosis in chronic HBV infection results in more severe clinical outcomes with superimposed acute hepatitis E. Anti-HBV treatment cannot improve the prognosis of liver failure caused by HBV-HEV superinfection.

Cheng, Si-Hong; Mai, Li; Zhu, Feng-Qin; Pan, Xing-Fei; Sun, Hai-Xia; Cao, Hong; Shu, Xin; Ke, Wei-Min; Li, Gang; Xu, Qi-Huan

2013-01-01

330

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

SciTech Connect

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

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

1990-11-01

331

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

EPA Science Inventory

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

332

Terrestrial vegetation and water balance—hydrological evaluation of a dynamic global vegetation model  

Microsoft Academic Search

Earth's vegetation plays a pivotal role in the global water balance. Hence, there is a need to model dynamic interactions and feedbacks between the terrestrial biosphere and the water cycle. Here, the hydrological performance of the Lund–Potsdam–Jena model (LPJ), a prominent dynamic global vegetation model, is evaluated. Models of this type simulate the coupled terrestrial carbon and water cycle, thus

Dieter Gerten; Sibyll Schaphoff; Uwe Haberlandt; Wolfgang Lucht; Stephen Sitch

2004-01-01

333

Hydrological modeling of stalagmite ?18O response to glacial-interglacial transitions  

NASA Astrophysics Data System (ADS)

Stalagmite ?18? series currently provide the most robustly dated characterization of glacial terminations. However, uncertainties associated with the stalagmite ?18? proxy record arise due to the complexity of flow within karst aquifers. Here we use an integrated climate-soil-groundwater lumped parameter hydrological model to demonstrate the range of potential stalagmite ?18? hydrological responses to significant global climate changes. Pseudoproxy stalagmite ?18? series were generated for millennial length model simulations, using general circulation model time-slice data for 12, 11, and 10 ka for eastern China. Our model demonstrates that the variability within published ?18? records from Chinese stalagmites falls within that of modeled pseudoproxy series. We utilize model output to (i) quantify hydrological uncertainty (specifically the relative importance of changing precipitation amount, isotopic composition, and water balance); (ii) identify any nonstationarity in ?18O variability and its relationship to climate change; and (iii) demonstrate the processes that produce low-frequency power in stalagmite ?18?.

Baker, Andy; Bradley, Chris; Phipps, Steven J.

2013-06-01

334

Snow Hydrology Model Combined with Remotely Sensed Snow Observations in the Upper Helmand Watershed, Afghanistan (Invited)  

NASA Astrophysics Data System (ADS)

In many regions of the world snowmelt can be an important source of water resources. However, limited data availability can make water resources planning and management difficult, particularly in developing countries. For this study, a temperature index snow model in conjunction with a hydrologic model was used to analyze the snowpack and hydrology of the Upper Helmand Watershed in Afghanistan. Limited ground data and remotely sensed precipitation data were used to develop and force the model. The snow model was calibrated using high-resolution multispectral imagery of the snow covered area (SCA). The calibrated snow model was compared to passive microwave estimates of snow water equivalent (SWE). Finally the peak snowpack, derived using the passive microwave SWE data, was used to initialize the hydrologic model prior to melt onset. The model’s ability to simulate runoff was validated using reservoir measurements at the basin outlet. This study improved our understanding of the hydrologic processes in this remote, data-scarce region. In particular, the snow extent and mass as well as the contribution of snow to runoff are quantified with enhanced confidence by using both the model simulations and remotely sensed data. The temperature index snow model accurately simulates the snow accumulation and melt process as demonstrated in the temporal and spatial comparison to the high-resolution SCA imagery. Inflows to the reservoir were reasonably simulated using the hydrologic model, though the model exhibited sensitivity to input precipitation data. The passive microwave SWE data provided reasonable estimates of snow mass and distribution in the Upper Helmand Watershed, and has potential for initializing hydrological models to add value to water supply planning and dam management.

Vuyovich, C. M.; Jacobs, J. M.; Daly, S. F.; Scharffenberg, W.

2010-12-01

335

Impact of land management on hydrological functioning in cultivated landscapes: a coupled model of functional assessment  

NASA Astrophysics Data System (ADS)

In cultivated landscapes, hydrological functioning is highly influenced by anthropic drivers. Indeed, spatio-temporal patterns in land management affect processes such as run-off or pollutant flow. Reciprocally, at the scale of a cropping season, hydrological functioning of land influences farmers' actions on crops. Consequently, the assessment of the hydrologic impacts of land management needs recognition of the global functioning of the system which requires a close coupling between the modelling of land management actions and hydrological processes. Most of hydrological models take into account a spatial representation of the landscape mosaic created by land management. However the resolution used for the temporal evolution of this pattern is coarser than the one required by hydrological model which simulate processes over short time steps. Consequently, there is a need for more accurate temporal representation of land management which means an analysis of the crop management systems and the integration of bio-physical feedback mechanisms on management decisions. We propose an approach for assessing the hydrological impact of crop management system in the specific case of pollutant loading in a perennial crop area, based on the coupling of a distributed hydrological model with a farmer's decision model. This latter model represents land management with decision rules applied by farmers to drive their collection of plots during the whole cropping cycle. It includes agronomic rules based on indicators of the state of the bio-physical system at plot levels as well as work organisation rules at farm level. Different types of crop management system induced by the diversity of farmers are thus represented by different rules set which can be spatially distributed. The spatial pattern in crop management represented by the decision model determines the hydrological functioning of the landscape. A feedback exists since the hydrological processes like the spatio-temporal evolution soil water content influence several farmer decisions like for example the choice of the dates of soil tillage. An application of the method is realised on a small (1 km²) Mediterranean catchment cultivated with vineyard with the prospect of providing a tool that can help farmers to evaluate different land management strategies.

Paré, Nakié; Biarnès, Anne; Barbier, Jean-Marc; Voltz, Marc

2010-05-01

336

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

PubMed

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

Achleitner, S; Rinderer, M; Kirnbauer, R

2009-01-01

337

A conceptual model of the hydrological influence of fissures on landslide activity  

NASA Astrophysics Data System (ADS)

Hydrological processes control the behaviour of many unstable slopes, and their importance for landslide activity is generally accepted. The presence of fissures influences the storage capacity of a soil and affects the infiltration processes of rainfall. The effectiveness of the fissure network depends upon fissure size, their spatial distribution, and connectivity. Moreover, fissure connectivity is a dynamic characteristic, depending on the degree of saturation of the medium. This research aims to investigate the influence of the fissure network on hydrological responses of a landslide. Special attention is given to spatial and temporal variations in fissure connectivity, which makes fissures act both as preferential flow paths for deep infiltration (disconnected fissures) and as lateral groundwater drains (connected fissures). To this end, the hydrological processes that control the exchange of water between the fissure network and the matrix have been included in a spatially distributed hydrological and slope stability model. The ensuing feedbacks in landslide hydrology were explored by running the model with one year of meteorological forcing. The effect of dynamic fissure connectivity was evaluated by comparing simulations with static fissure patterns to simulations in which these patterns change as a function of soil saturation. The results highlight that fissure connectivity and fissure permeability control the water distribution within landslides. Making the fissure connectivity function of soil moisture results in composite behaviour spanning the above end members and introduces stronger seasonality of the hydrological responses.

Krzeminska, D. M.; Bogaard, T. A.; van Asch, Th. W. J.; van Beek, L. P. H.

2012-06-01

338

Comparisons of regional hydrological excitation of polar motion from models and GRACE-based gravity results  

NASA Astrophysics Data System (ADS)

Here we estimate hydrological polar motion excitation functions over various land areas regionally both using a number of hydrological models (CPC, GLDAS, NOAA, LSDM) as well as deriving them from the gravity fields from the Gravity Recovery and Climate Experiment (GRACE). Our attention focuses on the estimations of the relative contributions of the continental areas to the overall global signal. For example, prominent maxima of hydrological excitation functions of polar motion are situated over the equatorial monsoonal regions of the Amazon, India, central and southern Africa, and northern Australia. In the patterns computed from one of the models (CPC), some signals over western Eurasia are also seen. We compare the timing, spectra and phase diagrams of hydrological excitation functions computed for these areas with each other and with the global polar motion excitation function. There are strong annual signals in the hydrological excitations, with the series from the solutions having somewhat different amplitudes and phases. Much agreement exists among the series, but there are outliers in some cases. The results help us understand one way in which regional variability of the hydrological cycle may impact the Earth globally, through polar motion excitation, because of temporal changes in the mass distribution.

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

2013-04-01

339

Non-parametric modelling of non-linear dynamic systems: death or revival of hydrological modeling?  

NASA Astrophysics Data System (ADS)

Catchments are incredibly complex natural systems and perceptual models of catchment hydrology tend to reflect this complexity. Despite this, their integrated responses, although non-linear, show for most systems some identifiable dominant response modes. State space parametric models having only a few parameters largely explain the latter. The conventional wisdom is that relatively short hydrologic records, say from one to a few years, are sufficient to infer the maximum model complexity allowed by the data. Our research hypothesis is that in sufficiently long records from carefully monitored catchments more complexity than the present modeling approach suggests can be unraveled. As an alternative to the latter, we propose a non-parametric non-linear approach based on a minimal set of hypotheses. A distinct, and most valuable in our opinion, feature of our approach is that it is able to 'learn' as more data is presented to it, with a corresponding increase in model complexity and prediction accuracy. We apply this approach on a range of hydrological systems having long, good quality, data series. Simple and interpretable models explain about 80% of the variance in discharges. Much more complex models are supported by the data, albeit with a slower pace of increase in overall prediction accuracy. Patterns of response that contribute little to a global fit criterion get better identified in the process, and can give useful insights in hydrological behaviour. Furthermore, we argue that the recursive partitioning method we use can be advantageously integrated in the evaluation process of state space parametric models. It provides a principled, and based on very few assumptions, way to establish conservative upper bounds of measurement errors for data sub-sets. These bounds are based on the information existent in data and extracted by the non-parametric model; they implicitly account for heteroscedastic errors. As a result tradeoffs between over-fitting modes of response that are not well identified, due to insufficient data and/or large measurement errors, and model errors higher than those justified by the data are less likely to occur. The constraints imposed in the evaluation process may prove sufficiently strong to eliminate a significant number of models and model structures and to support an increased complexity of parameter models.

Iorgulescu, I.; Beven, K. J.

2003-04-01

340

Estimation of theoretical maximum speedup ratio for parallel computing of grid-based distributed hydrological models  

NASA Astrophysics Data System (ADS)

Theoretical maximum speedup ratio (TMSR) can be used as a goal for improving parallel computing methods for distributed hydrological models. Different types of distributed hydrological models need different TMSR estimation methods because of the different computing characteristics of models. Existing TMSR estimation methods, such as those for sub-basin based distributed hydrological models, are inappropriate for grid-based distributed hydrological models. In this paper, we proposed a TMSR estimation method suitable for grid-based distributed hydrological models. With this method, TMSRs for hillslope processes and channel routing processes are calculated separately and then combined to obtain the overall TMSR. A branch-and-bound algorithm and a critical path heuristic algorithm are used to estimate TMSRs for parallel computing of hillslope processes and channel routing processes, respectively. The overall TMSR is calculated according to the proportions of computing these two types of processes. A preliminary application showed that the more the number of sub-basins, the larger the TMSRs and that the compact watersheds had larger TMSRs than the long narrow watersheds.

Liu, Junzhi; Zhu, A.-Xing; Qin, Cheng-Zhi

2013-10-01

341

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

NASA Astrophysics Data System (ADS)

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

Zegre, N. P.

2009-05-01

342

MODELING AND ANALYSIS OF GLOBAL AND REGIONAL HYDROLOGIC PROCESSES AND APPROPRIATE CONSERVATION OF MOIST ENTROPY  

SciTech Connect

The research supported by DOE funding addressed the fundamental issues of understanding and modeling of hydrologic processes in relation to regional and global climate change. The emphasis of this research effort was on the application of isentropic modeling and analysis to advance the accuracy of the simulation of all aspects of the hydrologic cycle including clouds and thus the climate state regionally and globally. Simulation of atmospheric hydrologic processes by the UW hybrid isentropic coordinate models provided fundamental insight into global monsoonal circulations, and regional energy exchange in relation to the atmospheric hydrologic cycle. Inter-comparison of UW hybrid model simulations with those from the NCAR Community Climate Model and other climate and numerical weather prediction (NWP) models investigated the increased accuracies gained in modeling long-range transport in isentropic coordinates and isolated differences in modeling of the climate state. The inter-comparisons demonstrated advantages in the simulation of the transport of the hydrologic components of the climate system and provided insight into the more general problems of simulating hydrologic processes, aerosols and chemistry for climate. This research demonstrated the viability of the UW isentropic-eta model for long-term integration for climate and climate change studies and documented that no insurmountable barriers exist to simulation of climate utilizing hybrid isentropic coordinate models. The results provide impetus for continued development of hybrid isentropic coordinate models as a means to advance accuracies in the simulation of global and regional climate in relation to transport and the planetary distribution of heat sources and sinks.

Donald Johnson, Todd Schaack

2007-06-08

343

Hydrological modeling in swelling\\/shrinking peat soils  

Microsoft Academic Search

Peatlands respond to natural hydrologic cycles of precipitation and evapotranspiration with reversible deformations due to variations of water content in both the unsaturated and saturated zone. This phenomenon results in short-term vertical displacements of the soil surface that superimpose to the irreversible long-term subsidence naturally occurring in drained cropped peatlands because of bio-oxidation of the organic matter. These processes cause

M. Camporese; S. Ferraris; M. Putti; P. Salandin; P. Teatini

2006-01-01

344

REMOTE SENSING OF IMPERVIOUS SURFACE AREA FOR IMPROVED HYDROLOGIC MODELING  

Microsoft Academic Search

Impervious surface area (ISA), one of the consequences of urban development, has been used as an important indicator for environmental impacts of urbanization. In this study, we extracted ISA information for the state of Rhode Island, USA from 1-m spatial resolution true-color digital orthophotography data by an object-based classification. As the importance of ISA in the watersheds hydrology, we developed

Y. Zhou; Y. Q. Wang

345

A simple algorithm for generating streamflow networks for grid-based, macroscale hydrological models  

NASA Astrophysics Data System (ADS)

A simple algorithm for generating streamflow networks for macroscale hydrological models (MHMs) from digital elevation models (DEMs) is presented. Typically these hydrological models are grid based, with the simulated runoff produced within each cell routed through a stream network which connects the centers of cells in the direction of the major streams. Construction of such stream networks is a time consuming task, which has generally been done by hand with the aid of maps. Results indicate that the algorithm works satisfactorily in areas of both high and low relief, and for a wide range of model cell resolutions, although some manual adjustments may be necessary.

O'Donnell, Greg; Nijssen, Bart; Lettenmaier, Dennis P.

1999-06-01

346

Towards a complete description of the hydrologic cycle: Large scale simulations with the open-source, parallel, ParFlow hydrologic model.  

NASA Astrophysics Data System (ADS)

Integrated hydrologic models are growing in application and show significant promise in unraveling connections between the surface, subsurface, land-surface and lower atmospheric systems. Recent advances in numerical methods, coupled formulation and computing power have all enabled these simulation advances. Here, I will discuss the modeling platform ParFlow, an integrated hydrologic model that has been coupled to land surface and atmospheric models. I will then discuss a recent application of this model to a large, Continental-Scale domain in North America at high resolution that encompasses both the Mississippi and Colorado watersheds. Details will include techniques for model setup and initialization, in addition to results that focus on understanding fluxes, feedbacks and systems dynamics. Additional anthropogenic complications such as the effects of pumping, irrigation and urbanization will be discussed and a path forward for integrated simulations of the hydrologic cycle will be presented.

Maxwell, R. M.; Condon, L. E.; Kollet, S. J.; Ferguson, I. M.; Williams, J. L.; ParFlow Development Team

2011-12-01

347

Development and Application of a Parsimonious Snow-Hydrologic Modeling Suite: Investigating the Link Between Model Complexity and Predictive Uncertainty  

NASA Astrophysics Data System (ADS)

The simulation and modeling of snowmelt and hydrologic drivers is desirable for prediction of different hydrologic variables, most significantly streamflow at the catchment outlet. This is particularly true of mountainous regions where snowmelt drives major hydrologic events and water resource predictability. We have developed a suite of parsimonious models of first-order snow and hydrologic processes to investigate the link between overall model complexity (both snow and hydrologic elements) and predictive performance. The use of simper models is motivated by the desire to capture first-order processes, in line with a top-down modeling philosophy. Such models have the capability to be more efficient in modeling the system by having less uncertainty with similar predictive power when compared to more complex model structures. Constructed in a modular fashion, the modeling suite has the ability to assess the interaction between each snowmelt and hydrologic base structure coupling, as well as to separate error between each component. The modeling suite was applied to the Stringer Creek watershed of Tenderfoot Creek Experimental Forest (TCEF), located in central Montana, USA. Making use of meteorological data collected at one of the two NRCS SNOTEL stations within TCEF's borders and streamflow data from the USFS Rocky Mountain Research Station (TCEF's managing agency), we compare the performance of different model combinations using 6 years of available data. Implementation of a Markov chain Monte Carlo approach to parameter estimation and uncertainty estimation provides the ability to characterize errors in the models (including non-stationarities), explore complex parameter spaces and interdependence, and incorporate multiple sources of data for model conditioning. The necessity of such abilities becomes especially critical in the application of a top-down modeling approach, where conceptual models are used that often involve highly interdependent model parameters. Further, the flexibility and design of the coupled, modular framework allows for the separation of uncertainty with regard to both snow and hydrologic process components.

Smith, T. J.; Marshall, L. A.

2008-12-01

348

A STREAMFLOW FORECASTING FRAMEWORK USING MULTIPLE CLIMATE AND HYDROLOGICAL MODELS1  

Microsoft Academic Search

Water resources planning and management efficacy is subject to capturing inherent uncertainties stemming from climatic and hydrological inputs and models. Streamflow forecasts, critical in reservoir operation and water allocation decision making, fundamentally contain uncertainties arising from assumed initial condi- tions, model structure, and modeled processes. Accounting for these propagating uncertainties remains a formi- dable challenge. Recent enhancements in climate forecasting

Paul J. Block; Francisco Assis Souza Filho; Liqiang Sun; Hyun-Han Kwon

349

Applying climate model precipitation scenarios for urban hydrological assessment: A case study in Kalmar City, Sweden  

Microsoft Academic Search

There is growing interest in the impact of climate change on urban hydrological processes. Such assessment may be based on the precipitation output from climate models. To date, the model resolution in both time and space has been too low for proper assessment, but at least in time the resolution of available model output is approaching urban scales. In this

J. Olsson; K. Berggren; M. Olofsson; M. Viklander

2009-01-01

350

Storm flood computation model for urban rain pipe networks based on hydrology  

Microsoft Academic Search

Based on hydrology, a storm flood computation model for urban rain pipe networks is proposed. In this model, the research region is divided into three areas, that is permeable area, impervious area and pipe area. The main methods include the isochronal method, Horton infiltration formula, time-contour method and Muskingum method. The proposed model in this paper is tested by the

Xiaona Zhang; Xiaofang Rui; Jie Feng

2009-01-01

351

Downscaling the hydrological cycle in the Mackenzie basin with the Canadian regional climate model  

Microsoft Academic Search

The Canadian Regional Climate Model (CRCM) has been nested within the Canadian Centre for Climate Modelling and Analysis ‘ second generation General Circulation Model (GCM), for a single month simulation over the Mackenzie River Basin and environs. The purpose of the study is to assess the ability of the higher resolution CRCM to downscale the hydrological cycle of the nesting

Murray D. MacKay; Ronald E. Stewart; Guy Bergeron

1998-01-01

352

State and Parameter Estimation of Hydrologic Models Using the Constrained Ensemble Kalman Filter  

Microsoft Academic Search

Physical or mathematical constraints on model states and system parameters usually exist in hydrologic models. Data assimilation techniques, such as the Kalman filter (KF) and its extensions, update state variables based on the KF type of algorithms, but state space models usually have relevant physical laws or settings. The updated states by the KF may violate some physical constraints, which

D. Wang; Y. Chen; X. Cai

2008-01-01

353

Spatially Distributed Estimation of Mesoscale Water Balance Model Parameters using Hydrological Soil Maps  

Microsoft Academic Search

In mesoscale water balance models, the relevant hydrological processes in runoff generation are abstractly simulated. One aspect of this abstraction is grouping areas to model elements, each of which simulated individually, resulting in a set of model elements. A single element might be homogeneous by means of a certain characteristics, e. g. land use, but it might also be heterogeneous

O. Gronz; M. C. Casper; P. Gemmar

2009-01-01

354

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

NASA Astrophysics Data System (ADS)

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

Buytaert, Wouter; Beven, Keith

2010-05-01

355

Inverse modeling for field-scale hydrologic and transport parameters of fractured basalt  

SciTech Connect

A large-scale test of infiltration into a thick sequence Of fractured Snake River Plain basalts was performed during the summer of 1994 on the Idaho National Engineering Laboratory. Monitoring of moisture and tracer movement during this test provided a set of quantitative measurements from which to obtain a field-scale hydrologic description of the fractured basalts. An inverse modeling study using these quantitative measurements was performed to obtain the representative hydrologic description. This report describes the results of the inverse modeling study and includes the background and motivation for conducting the infiltration test; a brief overview of the infiltration test; descriptions of the calibration targets chosen for the simulation study, the simulation model, and the model implementation; and the simulation results with comparisons to hydrologic and tracer breakthrough data obtained from the infiltration test.

Magnuson, S.O.

1995-12-01

356

A limited-memory acceleration strategy for MCMC sampling in hierarchical Bayesian calibration of hydrological models  

NASA Astrophysics Data System (ADS)

Hydrological calibration and prediction using conceptual models is affected by forcing/response data uncertainty and structural model error. The Bayesian Total Error Analysis methodology uses a hierarchical representation of individual sources of uncertainty. However, it is shown that standard multiblock "Metropolis-within-Gibbs" Markov chain Monte Carlo (MCMC) samplers commonly used in Bayesian hierarchical inference are exceedingly computationally expensive when applied to hydrologic models, which use recursive numerical solutions of coupled nonlinear differential equations to describe the evolution of catchment states such as soil and groundwater storages. This note develops a "limited-memory" algorithm for accelerating multiblock MCMC sampling from the posterior distributions of such models using low-dimensional jump distributions. The new algorithm exploits the decaying memory of hydrological systems to provide accurate tolerance-based approximations of traditional "full-memory" MCMC methods and is orders of magnitude more efficient than the latter.

Kuczera, George; Kavetski, Dmitri; Renard, Benjamin; Thyer, Mark

2010-07-01

357

Towards a regional climate model coupled to a comprehensive hydrological model  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

358

Assessment of terrestrial water contributions to polar motion from GRACE and hydrological models  

NASA Astrophysics Data System (ADS)

The hydrological contribution to polar motion is a major challenge in explaining the observed geodetic residual of non-atmospheric and non-oceanic excitations since hydrological models have limited input of comprehensive global direct observations. Although global terrestrial water storage (TWS) estimated from the Gravity Recovery and Climate Experiment (GRACE) provides a new opportunity to study the hydrological excitation of polar motion, the GRACE gridded data are subject to the post-processing de-striping algorithm, spatial gridded mapping and filter smoothing effects as well as aliasing errors. In this paper, the hydrological contributions to polar motion are investigated and evaluated at seasonal and intra-seasonal time scales using the recovered degree-2 harmonic coefficients from all GRACE spherical harmonic coefficients and hydrological models data with the same filter smoothing and recovering methods, including the Global Land Data Assimilation Systems (GLDAS) model, Climate Prediction Center (CPC) model, the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis products and European Center for Medium-Range Weather Forecasts (ECMWF) operational model (opECMWF). It is shown that GRACE is better in explaining the geodetic residual of non-atmospheric and non-oceanic polar motion excitations at the annual period, while the models give worse estimates with a larger phase shift or amplitude bias. At the semi-annual period, the GRACE estimates are also generally closer to the geodetic residual, but with some biases in phase or amplitude due mainly to some aliasing errors at near semi-annual period from geophysical models. For periods less than 1-year, the hydrological models and GRACE are generally worse in explaining the intraseasonal polar motion excitations.

Jin, S. G.; Hassan, A. A.; Feng, G. P.

2012-12-01

359

Calibration analysis of the global hydrological model WGHM with water mass variations from GRACE gravity data  

NASA Astrophysics Data System (ADS)

Time-variable gravity data of the GRACE (Gravity Recovery And Climate Experiment) satellite mission provide global information on temporal variations of continental water storage. Consequently, these data provide a valuable input for validation and calibration of large scale hydrological models. In this study, we continue our work to incorporate GRACE data for the first time directly into the tuning process of a global hydrological model to improve simulations of the continental water cycle. For the WaterGAP Global Hydrology Model (WGHM), we adopt an efficient multi-objective calibration framework to constrain model predictions by both measured river discharge and water storage variations from GRACE. The calibration was done for the 22 largest river basins worldwide and is illustrated by the examples of several river basins. The approach leads to improved simulation results with regard to both objectives. In case of monthly total water storage variations we obtained a RMSE reduction of about 25 mm for the Amazon and 6 mm for the Mississippi, for instance. In addition, the calibration results are analyzed in order to derive possible model structure errors or mis- modeled processes for specific river basins. It is our aim to improve the understanding of hydrological processes on the continental scale. We analyze river basins with various process characteristics and their calibration performance on single processes related to water storages of groundwater, canopy, snow, soil and surface water. Furthermore, a comparison of calibration results for different GRACE-data extractions is presented. The results highlight the valuable nature of GRACE data when merged into large-scale hydrological modeling and depict methods to improve large-scale hydrological models.

Werth, S.; Guentner, A.; Petrovic, S.; Schmidt, R.

2008-12-01

360

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

NASA Astrophysics Data System (ADS)

Future changes in runoff can have important implications for water resources and flooding. In this study, runoff projections from ISI-MIP (Inter-sectoral Impact Model Intercomparison Project) simulations forced with HadGEM2-ES bias-corrected climate data under the Representative Concentration Pathway 8.5 have been analysed for differences between impact models. Projections of change from a baseline period (1981-2010) to the future (2070-2099) from 12 impacts models which contributed to the hydrological and biomes sectors of ISI-MIP were studied. The biome models differed from the hydrological models by the inclusion of CO2 impacts and most also included a dynamic vegetation distribution. The biome and hydrological models agreed on the sign of runoff change for most regions of the world. However, in West Africa, the hydrological models projected drying, and the biome models a moistening. The biome models tended to produce larger increases and smaller decreases in regionally averaged runoff than the hydrological models, although there is large inter-model spread. The timing of runoff change was similar, but there were differences in magnitude, particularly at peak runoff. The impact of vegetation distribution change was much smaller than the projected change over time, while elevated CO2 had an effect as large as the magnitude of change over time projected by some models in some regions. The effect of CO2 on runoff was not consistent across the models, with two models showing increases and two decreases. There was also more spread in projections from the runs with elevated CO2 than with constant CO2. The biome models which gave increased runoff from elevated CO2 were also those which differed most from the hydrological models. Spatially, regions with most difference between model types tended to be projected to have most effect from elevated CO2, and seasonal differences were also similar, so elevated CO2 can partly explain the differences between hydrological and biome model runoff change projections. Therefore, this shows that a range of impact models should be considered to give the full range of uncertainty in impacts studies.

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

2013-10-01

361

Using a distributed hydrologic model to assess the impact of urbanization in Singapore  

NASA Astrophysics Data System (ADS)

A fully distributed hydrological model (MOBIDIC) is applied to study the impact of urbanization on local hydrology in the Kranji watershed, Northwest Singapore. Based on the available data, the MOBIDIC is firstly calibrated at the two sub-watersheds (KC2 and KC6), where the percentages of urbanized area are 80% in KC2, while 6% in KC6. Different urban expansion scenarios are developed through buffer analysis and the corresponding hydrologic responses are simulated by the MOBIDIC model, and the simulations are compared with the predictions from a linear model which is a combination of contributions from the urbanized area and non-urbanized area. An elasticity measure is also developed to measure the degree of linearity in the hydrologic responses. Results show: i) As the urbanized area increases, "groundwater", "soil water", "evaporation", "baseflow", "hypodermic flow", and "percolation" increase, while "surface runoff", "watershed outflow", and "flow peak" decrease, which is consistent with the literature; ii) Through the comparison with the linear model and the analysis with elasticity measure, these hydrologic responses have a close linear relationship with urbanized area.

Yang, J.; Entekhabi, D.; Castelli, F.; Chua, L.

2011-12-01

362

Evolution of Modeling Strategies for Operational Hydrologic Models with Changing Timescales  

NASA Astrophysics Data System (ADS)

Hydrologic forecasting models are used at a range of timescales: at short timescales for flood forecasting, at intermediate timescales for seasonal flow forecasting, and long timescales for decadal to century scale for global change predictions. Often models are developed for each of these purposes rather independently, sometimes in an ad hoc manner, leading to inefficiencies and leaving no room for flexibility and continuous refinement. In this paper we present a consistent framework for the development of distributed models at each of these timescales that enable a seamless transition as we transition from small to large timescales and accommodate the cascading of variability across the full range of timescales as well as, where needed, the interactions between water flow processes and other land-forming and life sustaining processes. This framework accommodates a synthesis of both bottom-up and top-down approaches to modeling that enable inclusion of laws of mass, momentum and energy balances, as well as the ability to embrace the learning from patterns in observed hydrologic responses. The proposed approach is a synthesis of the REW approach to distributed modeling proposed by Reggiani et al. (1998, 1999), and the data-based top-down approach to modeling reviewed by Sivapalan et al. (2003). We will articulate these ideas with respect to model development efforts in Australia for short, intermediate and long term streamflow forecasting at regional and continental scales as part of the WIRADA project.

Sivapalan, M.

2011-12-01

363

Upscaling Empirically Based Conceptualisations to Model Tropical Dominant Hydrological Processes for Historical Land Use Change  

NASA Astrophysics Data System (ADS)

Surface runoff and percolation to ground water are two hydrological processes of concern to the Atlantic slope of Costa Rica because of their impacts on flooding and drinking water contamination. As per legislation, the Costa Rican Government funds land use management from the farm to the regional scale to improve or conserve hydrological ecosystem services. In this study, we examined how land use (e.g., forest, coffee, sugar cane, and pasture) affects hydrological response at the point, plot (1 m2), and the field scale (1-6ha) to empirically conceptualize the dominant hydrological processes in each land use. Using our field data, we upscaled these conceptual processes into a physically-based distributed hydrological model at the field, watershed (130 km2), and regional (1500 km2) scales. At the point and plot scales, the presence of macropores and large roots promoted greater vertical percolation and subsurface connectivity in the forest and coffee field sites. The lack of macropores and large roots, plus the addition of management artifacts (e.g., surface compaction and a plough layer), altered the dominant hydrological processes by increasing lateral flow and surface runoff in the pasture and sugar cane field sites. Macropores and topography were major influences on runoff generation at the field scale. Also at the field scale, antecedent moisture conditions suggest a threshold behavior as a temporal control on surface runoff generation. However, in this tropical climate with very intense rainstorms, annual surface runoff was less than 10% of annual precipitation at the field scale. Significant differences in soil and hydrological characteristics observed at the point and plot scales appear to have less significance when upscaled to the field scale. At the point and plot scales, percolation acted as the dominant hydrological process in this tropical environment. However, at the field scale for sugar cane and pasture sites, saturation-excess runoff increased as irrigation intensity and duration (e.g., quantity) increased. Upscaling our conceptual models to the watershed and regional scales, historical data (1970-2004) was used to investigate whether dominant hydrological processes changed over time due to land use change. Preliminary investigations reveal much higher runoff coefficients (<30%) at the larger watershed scales. The increase in importance of runoff at the larger geographic scales suggests an emerging process and process non-linearity between the smaller and larger scales. Upscaling