Turning Maneuver Limitations Imposed by Sudden Strut Side Ventilation on a 200-Ton 80-Knot Hydrofoil Craft

DTIC Science & Technology

1975-05-01

ventilated, but never supercavitating , for speeds up to 80 knots. In particular, choking of the air flow to the foil vent was not con- sidered. If this...4Conolly, A.C., "Experimental Investigations of Supercavitating Hydrofoils with Flaps," General Dynamics/Convair Report GD/C-63-210 (Dec 1963). 10 THE SIX...Dec 1966). 4. Conolly, A.C., "Experimenta, Investigations of Supercavitating Hydro- foils with Flaps," General Dynamics/Convair Report GD/C-63-210 (Dec

Experimental study of porous media flow using hydro-gel beads and LED based PIV

NASA Astrophysics Data System (ADS)

Harshani, H. M. D.; Galindo-Torres, S. A.; Scheuermann, A.; Muhlhaus, H. B.

2017-01-01

A novel experimental approach for measuring porous flow characteristics using spherical hydro-gel beads and particle image velocimetry (PIV) technique is presented. A transparent porous medium consisting of hydro-gel beads that are made of a super-absorbent polymer, allows using water as the fluid phase while simultaneously having the same refractive index. As a result, a more adaptable and cost effective refractive index matched (RIM) medium is created. The transparent nature of the porous medium allows optical systems to visualize the flow field by using poly-amide seeding particles (PSP). Low risk light emitting diode (LED) based light was used to illuminate the plane in order to track the seeding particles’ path for the characterization of the flow inside the porous medium. The system was calibrated using a manually measured flow by a flow meter. Velocity profiles were obtained and analysed qualitatively and quantitatively in order to characterise the flow. Results show that this adaptable, low risk experimental set-up can be used for flow measurements in porous medium under low Reynolds numbers. The limitations of using hydro-gel beads are also discussed.

Microfabrication and Test of a Three-Dimensional Polymer Hydro-focusing Unit for Flow Cytometry Applications

NASA Technical Reports Server (NTRS)

Yang, Ren; Feeback, Daniel L.; Wang, Wan-Jun

2005-01-01

This paper details a novel three-dimensional (3D) hydro-focusing micro cell sorter for micro flow cytometry applications. The unit was microfabricated by means of SU-8 3D lithography. The 3D microstructure for coaxial sheathing was designed, microfabricated, and tested. Three-dimensional hydrofocusing capability was demonstrated with an experiment to sort labeled tanned sheep erythrocytes (red blood cells). This polymer hydro-focusing microstructure is easily microfabricated and integrated with other polymer microfluidic structures. Keywords: SU-8, three-dimensional hydro-focusing, microfluidic, microchannel, cytometer

Movement and collision of Lagrangian particles in hydro-turbine intakes: a case study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romero-Gomez, Pedro; Richmond, Marshall C.

Studies of the stress/survival of migratory fish during downstream passage through operating hydro-turbines are normally conducted to determine the fish-friendliness of units. One field approach consisting of recording extreme hydraulics with autonomous sensors is largely sensitive to the conditions of sensor release and the initial trajectories at the turbine intake. This study applies a modelling strategy based on flow simulations using computational fluid dynamics and Lagrangian particle tracking to represent the travel of live fish and autonomous sensor devices through hydro-turbine intakes. For the flow field calculation, the simulations were conducted with both a time-averaging turbulence model and an eddy-resolvingmore » technique. For the particle tracking calculation, different modelling assumptions for turbulence forcing, mass formulation, buoyancy, and release condition were tested. The modelling assumptions are evaluated with respect to data sets collected using a laboratory physical model and an autonomous sensor device deployed at Ice Harbor Dam (Snake River, State of Washington, U.S.A.) at the same discharge and release point as in the present computer simulations. We found an acceptable agreement between the simulated results and observed data and discuss relevant features of Lagrangian particle movement that are critical in turbine design and in the experimental design of field studies.« less

78 FR 58301 - Go With the Flow Hydro Power, LLC; Notice of Preliminary Permit Application Accepted for Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-23

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 14538-000] Go With the Flow..., Motions To Intervene, and Competing Applications On July 22, 2013, Go with the Flow Hydro Power, LLC...), proposing to study the feasibility of the Go with the Flow Hydroelectric Project (project) to be located on...

Effect of hydro mechanical coupling on natural fracture network formation in sedimentary basins

NASA Astrophysics Data System (ADS)

Ouraga, Zady; Guy, Nicolas; Pouya, Amade

2018-05-01

In sedimentary basin context, numerous phenomena, depending on the geological time span, can result in natural fracture network formation. In this paper, fracture network and dynamic fracture spacing triggered by significant sedimentation rate are studied considering mode I fracture propagation using a coupled hydro-mechanical numerical methods. The focus is put on synthetic geological structure under a constant sedimentation rate on its top. This model contains vertical fracture network initially closed and homogeneously distributed. The fractures are modelled with cohesive zone model undergoing damage and the flow is described by Poiseuille's law. The effect of the behaviour of the rock is studied and the analysis leads to a pattern of fracture network and fracture spacing in the geological layer.

Boundary Layer Flow Control with a One Atmosphere Uniform Glow Discharge Surface Plasma

NASA Technical Reports Server (NTRS)

Roth, J. Reece; Sherman, Daniel M.; Wilkinson, Stephen P.

1998-01-01

Low speed wind tunnel data have been acquired for planar panels covered by a uniform, glow-discharge surface plasma in atmospheric pressure air known as the One Atmosphere Uniform Glow Discharge Plasma (OAUGDP). Streamwise and spanwise arrays of flush, plasma-generating surface electrodes have been studied in laminar, transitional, and fully turbulent boundary layer flow. Plasma between symmetric streamwise electrode strips caused large increases in panel drag, whereas asymmetric spanwise electrode configurations produced a significant thrust. Smoke wire flow visualization and mean velocity diagnostics show the primary cause of the phenomena to be a combination of mass transport and vortical structures induced by strong paraelectric ElectroHydroDynamic (EHD) body forces on the flow.

75 FR 11150 - Free Flow Power Qualified Hydro 23, LLC; Notice of Preliminary Permit Application Accepted for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-10

... Qualified Hydro 23, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting... Power Qualified Hydro 23, LLC (FFP Qualified Hydro 23) filed an application for a preliminary permit... new 2.6-mile- long, 23-kilovolt transmission line; and (5) appurtenant facilities. The proposed...

ENVIRONMENTAL TECHNOLOGY VERIFICATION: JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT HYDRO COMPLIANCE MANAGEMENT, INC. HYDRO-KLEEN FILTRATION SYSTEM, 03/07/WQPC-SWP, SEPTEMBER 2003

EPA Science Inventory

Verification testing of the Hydro-Kleen(TM) Filtration System, a catch-basin filter designed to reduce hydrocarbon, sediment, and metals contamination from surface water flows, was conducted at NSF International in Ann Arbor, Michigan. A Hydro-Kleen(TM) system was fitted into a ...

Identifying Hydrogeological Controls of Catchment Low-Flow Dynamics Using Physically Based Modelling

NASA Astrophysics Data System (ADS)

Cochand, F.; Carlier, C.; Staudinger, M.; Seibert, J.; Hunkeler, D.; Brunner, P.

2017-12-01

Identifying key catchment characteristics and processes which control the hydrological response under low-flow conditions is important to assess the catchments' vulnerability to dry periods. In the context of a Swiss Federal Office for the Environment (FOEN) project, the low-flow behaviours of two mountainous catchments were investigated. These neighboring catchments are characterized by the same meteorological conditions, but feature completely different river flow dynamics. The Roethenbach is characterized by high peak flows and low mean flows. Conversely, the Langete is characterized by relatively low peak flows and high mean flow rates. To understand the fundamentally different behaviour of the two catchments, a physically-based surface-subsurface flow HydroGeoSphere (HGS) model for each catchment was developed. The main advantage of a physically-based model is its ability to realistically reproduce processes which play a key role during low-flow periods such as surface-subsurface interactions or evapotranspiration. Both models were calibrated to reproduce measured groundwater heads and the surface flow dynamics. Subsequently, the calibrated models were used to explore the fundamental physics that control hydrological processes during low-flow periods. To achieve this, a comparative sensitivity analysis of model parameters of both catchments was carried out. Results show that the hydraulic conductivity of the bedrock (and weathered bedrock) controls the catchment water dynamics in both models. Conversely, the properties of other geological formations such as alluvial aquifer or soil layer hydraulic conductivity or porosity play a less important role. These results change significantly our perception of the streamflow catchment dynamics and more specifically the way to assess catchment vulnerability to dry period. This study suggests that by analysing catchment scale bedrock properties, the catchment dynamics and the vulnerability to dry period may be assessed.

Dynamic Floodplain representation in hydrologic flood forecasting using WRF-Hydro modeling framework

NASA Astrophysics Data System (ADS)

Gangodagamage, C.; Li, Z.; Maitaria, K.; Islam, M.; Ito, T.; Dhondia, J.

2016-12-01

Floods claim more lives and damage more property than any other category of natural disaster in the Continental United States. A system that can demarcate local flood boundaries dynamically could help flood prone communities prepare for and even prevent from catastrophic flood events. Lateral distance from the centerline of the river to the right and left floodplains for the water levels coming out of the models at each grid location have not been properly integrated with the national hydrography dataset (NHDPlus). The NHDPlus dataset represents the stream network with feature classes such as rivers, tributaries, canals, lakes, ponds, dams, coastlines, and stream gages. The NHDPlus dataset consists of approximately 2.7 million river reaches defining how surface water drains to the ocean. These river reaches have upstream and downstream nodes and basic parameters such as flow direction, drainage area, reach slope etc. We modified an existing algorithm (Gangodagamage et al., 2007) to provide lateral distance from the centerline of the river to the right and left floodplains for the flows simulated by models. Previous work produced floodplain boundaries for static river stages (i.e. 3D metric: distance along the main stem, flow depth, lateral distance from river center line). Our new approach introduces the floodplain boundary for variable water levels at each reach with the fourth dimension, time. We use modeled flows from WRF-Hydro and demarcate the right and left lateral boundaries of inundation dynamically by appropriately mapping discharges into hydraulically corrected stages. Backwater effects from the mainstem to tributaries are considered and proper corrections are applied for the tributary inundations. We obtained river stages by optimizing reach level channel parameters using newly developed stream flow routing algorithm. Non uniform inundations are mapped at each NHDplus reach (upstream and downstream nodes) and spatial interpolation is carried out on a normalized digital elevation model (always streams are at zero elevations) to obtain the smooth flood boundaries between adjacent reaches. The validation of the dynamic inundation boundaries is performed using multi-temporal satellite datasets as well as HEC-RAS hydrodynamic model results for selected streams for previous flood events.

Does the uncertainty in the representation of terrestrial water flows affect precipitation predictability? A WRF-Hydro ensemble analysis for Central Europe

NASA Astrophysics Data System (ADS)

Arnault, Joel; Rummler, Thomas; Baur, Florian; Lerch, Sebastian; Wagner, Sven; Fersch, Benjamin; Zhang, Zhenyu; Kerandi, Noah; Keil, Christian; Kunstmann, Harald

2017-04-01

Precipitation predictability can be assessed by the spread within an ensemble of atmospheric simulations being perturbed in the initial, lateral boundary conditions and/or modeled processes within a range of uncertainty. Surface-related processes are more likely to change precipitation when synoptic forcing is weak. This study investigates the effect of uncertainty in the representation of terrestrial water flows on precipitation predictability. The tools used for this investigation are the Weather Research and Forecasting (WRF) model and its hydrologically-enhanced version WRF-Hydro, applied over Central Europe during April-October 2008. The WRF grid is that of COSMO-DE, with a resolution of 2.8 km. In WRF-Hydro, the WRF grid is coupled with a sub-grid at 280 m resolution to resolve lateral terrestrial water flows. Vertical flow uncertainty is considered by modifying the parameter controlling the partitioning between surface runoff and infiltration in WRF, and horizontal flow uncertainty is considered by comparing WRF with WRF-Hydro. Precipitation predictability is deduced from the spread of an ensemble based on three turbulence parameterizations. Model results are validated with E-OBS precipitation and surface temperature, ESA-CCI soil moisture, FLUXNET-MTE surface evaporation and GRDC discharge. It is found that the uncertainty in the representation of terrestrial water flows is more likely to significantly affect precipitation predictability when surface flux spatial variability is high. In comparison to the WRF ensemble, WRF-Hydro slightly improves the adjusted continuous ranked probability score of daily precipitation. The reproduction of observed daily discharge with Nash-Sutcliffe model efficiency coefficients up to 0.91 demonstrates the potential of WRF-Hydro for flood forecasting.

Combining abiotic and biotic models - Hydraulical modeling to fill the gap between catchment and hydro-dynamic models

NASA Astrophysics Data System (ADS)

Guse, B.; Sulc, D.; Schmalz, B.; Fohrer, N.

2012-04-01

The European Water Framework Directive (WFD) requires a catchment-based approach, which is assessed in the IMPACT project by combining abiotic and biotic models. The core point of IMPACT is a model chain (catchment model -> 1-D-hydraulic model -> 3-D-hydro-morphodynamic model -> biotic habitat model) with the aim to estimate the occurrence of the target species of the WFD. Firstly, the model chain is developed for the current land use and climate conditions. Secondly, land use and climate change scenarios are developed at the catchment scale. The outputs of the catchment model for the scenarios are used as input for the next models within the model chain to estimate the effect of these changes on the target species. The eco-hydrological catchment model SWAT is applied for the Treene catchment in Northern Germany and delivers discharge and water quality parameters as a spatial explicit output for each subbasin. There is no water level information given by SWAT. However, water level values are needed as lower boundary condition for the hydro-dynamic and habitat models which are applied for the 300 m candidate reference reach. In order to fill the gap between the catchment and the hydro-morphodynamic model, the 1-D hydraulic model HEC-RAS is applied for a 3 km long reach transect from the next upstream hydrological station until the upper bound of the candidate study reach. The channel geometry for HEC-RAS was estimated based on 96 cross-sections which were measured in the IMPACT project. By using available discharge and water level measurements from the hydrological station and own flow velocity measurements, the channel resistence was estimated. HEC-RAS was run with different statistical indices (mean annual drought, mean discharge, …) for steady flow conditions. The rating curve was then constructed for the target cross-section, i.e. the lower bound of the candidate study reach, to fulfill the combining with the hydro- and morphodynamic models. These statistical indices can also be calculated for the discharge series provided by land use and climate scenarios. In this way, the effect of land use and climate change on the catchment and the hydraulic processes can be assessed.

Dynamics analysis of the fast-slow hydro-turbine governing system with different time-scale coupling

NASA Astrophysics Data System (ADS)

Zhang, Hao; Chen, Diyi; Wu, Changzhi; Wang, Xiangyu

2018-01-01

Multi-time scales modeling of hydro-turbine governing system is crucial in precise modeling of hydropower plant and provides support for the stability analysis of the system. Considering the inertia and response time of the hydraulic servo system, the hydro-turbine governing system is transformed into the fast-slow hydro-turbine governing system. The effects of the time-scale on the dynamical behavior of the system are analyzed and the fast-slow dynamical behaviors of the system are investigated with different time-scale. Furthermore, the theoretical analysis of the stable regions is presented. The influences of the time-scale on the stable region are analyzed by simulation. The simulation results prove the correctness of the theoretical analysis. More importantly, the methods and results of this paper provide a perspective to multi-time scales modeling of hydro-turbine governing system and contribute to the optimization analysis and control of the system.

Microfabrication and Test of a Three-Dimensional Polymer Hydro-Focusing Unit for Flow Cytometry Applications

NASA Technical Reports Server (NTRS)

Yang, Ren; Feedback, Daniel L.; Wang, Wanjun

2004-01-01

This paper details a novel three-dimensional (3D) hydro-focusing micro cell sorter for micro flow cytometry applications. The unit was micro-fabricated by means of SU-8 3D lithography. The 3D microstructure for coaxial sheathing was designed, micro-fabricated, and tested. Three-dimensional hydrofocusing capability was demonstrated with an experiment to sort labeled tanned sheep erythrocytes (red blood cells). This polymer hydro-focusing microstructure is easily micro-fabricated and integrated with other polymer microfluidic structures.

Theoretical analysis and design of hydro-hammer with a jet actuator: An engineering application to improve the penetration rate of directional well drilling in hard rock formations.

PubMed

He, Jiang-Fu; Liang, Yun-Pei; Li, Li-Jia; Luo, Yong-Jiang

2018-01-01

Rapid horizontal directional well drilling in hard or fractured formations requires efficient drilling technology. The penetration rate of conventional hard rock drilling technology in horizontal directional well excavations is relatively low, resulting in multiple overgrinding of drill cuttings in bottom boreholes. Conventional drilling techniques with reamer or diamond drill bit face difficulties due to the long construction periods, low penetration rates, and high engineering costs in the directional well drilling of hard rock. To improve the impact energy and penetration rate of directional well drilling in hard formations, a new drilling system with a percussive and rotary drilling technology has been proposed, and a hydro-hammer with a jet actuator has also been theoretically designed on the basis of the impulse hydro-turbine pressure model. In addition, the performance parameters of the hydro-hammer with a jet actuator have been numerically and experimentally analyzed, and the influence of impact stroke and pumped flow rate on the motion velocity and impact energy of the hydro-hammer has been obtained. Moreover, the designed hydro-hammer with a jet actuator has been applied to hard rock drilling in a trenchless drilling program. The motion velocity of the hydro-hammer ranges from 1.2 m/s to 3.19 m/s with diverse flow rates and impact strokes, and the motion frequency ranges from 10 Hz to 22 Hz. Moreover, the maximum impact energy of the hydro-hammer is 407 J, and the pumped flow rate is 2.3 m3/min. Thus, the average penetration rate of the optimized hydro-hammer improves by over 30% compared to conventional directional drilling in hard rock formations.

Theoretical analysis and design of hydro-hammer with a jet actuator: An engineering application to improve the penetration rate of directional well drilling in hard rock formations

PubMed Central

He, Jiang-fu; Li, Li-jia; Luo, Yong-jiang

2018-01-01

Rapid horizontal directional well drilling in hard or fractured formations requires efficient drilling technology. The penetration rate of conventional hard rock drilling technology in horizontal directional well excavations is relatively low, resulting in multiple overgrinding of drill cuttings in bottom boreholes. Conventional drilling techniques with reamer or diamond drill bit face difficulties due to the long construction periods, low penetration rates, and high engineering costs in the directional well drilling of hard rock. To improve the impact energy and penetration rate of directional well drilling in hard formations, a new drilling system with a percussive and rotary drilling technology has been proposed, and a hydro-hammer with a jet actuator has also been theoretically designed on the basis of the impulse hydro-turbine pressure model. In addition, the performance parameters of the hydro-hammer with a jet actuator have been numerically and experimentally analyzed, and the influence of impact stroke and pumped flow rate on the motion velocity and impact energy of the hydro-hammer has been obtained. Moreover, the designed hydro-hammer with a jet actuator has been applied to hard rock drilling in a trenchless drilling program. The motion velocity of the hydro-hammer ranges from 1.2 m/s to 3.19 m/s with diverse flow rates and impact strokes, and the motion frequency ranges from 10 Hz to 22 Hz. Moreover, the maximum impact energy of the hydro-hammer is 407 J, and the pumped flow rate is 2.3 m3/min. Thus, the average penetration rate of the optimized hydro-hammer improves by over 30% compared to conventional directional drilling in hard rock formations. PMID:29768421

Linking hydrology, morphodynamics and ecology to assess the restoration potential of the heavily regulated Sarca River, NE Italy

NASA Astrophysics Data System (ADS)

Carolli, Mauro; Zolezzi, Guido; Pellegrini, Stefano; Gelmini, Francesca; Deriu, Micaela

2017-04-01

We develop an integrated eco-hydro-morphological quantitative investigation of the upper course of the Alpine Sarca River (NE Italy), for the purpose of assessing its potential in terms of environmental restoration. The Sarca River has been subject to heavy exploitation for hydropower production since the 1950s through a complex infrastructural system. As for many regulated Alpine rivers, increasing local interest has recently been developing to design and implement river restoration measures to improve the environmental conditions and ecosystem services that the river can provide. The aim of the work is to develop and apply a quantitative approach for a preliminary assessment of the successful potential of different river restoration options in the light of the recent eco-hydro-morphological dynamics of the Sarca river system at the catchment scale. The proposed analysis consists of three main steps: (1) detection of the main drivers of flow and sediment supply regimes alteration and characterization of such alteration; (2) a quantification of the effects of those alterations on geomorphic processes and fish habitat conditions; (3) the analysis of the restoration potential in the light of the results of the previous assessment. The analysis is tailored to the existing data availability, which is relatively high as for most river systems of comparable size in Europe, but not as much as in the case of a targeted research project, thus providing a representative case for many other regulated river catchments. Hydrological alteration is quantified by comparing recent (20 years) streamflow time series with a reconstructed series of analogous length, using a hydrological model that has been run excluding any man-made water abstraction, release and artificial reservoirs. upstream and downstream a large dam in the middle course of the river. By choosing the adult marble trout as target (endemic) fish species, effects of the alterations on the temporal and spatial habitat suitability have been assessed by applying a hydraulic-habitat method combined with the streamflow time series. Geomorphological trajectories of the last decades have been reconstructed through the analysis of aerial photos, and the geomorphic effects of flow regime alteration have been assessed in terms of the changes in frequency and duration of gravel-transporting flood events. Results indicate hydropower as one of the drivers of hydro-morphological alteration, with widespread torrent control works in the catchment playing a relevant role in reducing sediment supply. Recent changes in flow management related to the imposition of a Minimum Environmental Flow correspond to significant increase in the continuous duration of suitable habitat events, despite representing only a first step towards a dynamic ecological flow regime. While floods able to drive morphological changes still occurred after regulation, their frequency and duration have dramatically decreased, contributing to channel narrowing and morphological simplification. Overall, the analysis suggests that: (i) morphological river restoration aimed at restoring self-formed morphodynamics can only be effective if designed together with a dynamic geomorphic flow regime, and (ii) dynamic ecological flows should designed with a twofold objective of improving habitat and spawning sites conditions together with recreational uses of the river.

Using object-based geomorphometry for hydro-geomorphological analysis in a Mediterranean research catchment

NASA Astrophysics Data System (ADS)

Guida, Domenico; Cuomo, Albina; Palmieri, Vincenzo

2016-08-01

The aim of the paper is to apply an object-based geomorphometric procedure to define the runoff contribution areas and support a hydro-geomorphological analysis of a 3 km2 Mediterranean research catchment (southern Italy). Daily and sub-hourly discharge and electrical conductivity data were collected and recorded during a 3-year monitoring activity. Hydro-chemograph analyses carried out on these data revealed a strong seasonal hydrological response in the catchment that differed from the stormflow events that occur in the wet periods and in dry periods. This analysis enabled us to define the hydro-chemograph signatures related to increasing flood magnitude, which progressively involves various runoff components (baseflow, subsurface flow and surficial flow) and an increasing contributing area to discharge. Field surveys and water table/discharge measurements carried out during a selected storm event enabled us to identify and map specific runoff source areas with homogeneous geomorphological units previously defined as hydro-geomorphotypes (spring points, diffuse seepage along the main channel, seepage along the riparian corridors, diffuse outflow from hillslope taluses and concentrate sapping from colluvial hollows). Following the procedures previously proposed and used by authors for object-based geomorphological mapping, a hydro-geomorphologically oriented segmentation and classification was performed with the eCognition (Trimble, Inc.) package. The best agreement with the expert-based geomorphological mapping was obtained with weighted plan curvature at different-sized windows. By combining the hydro-chemical analysis and object-based hydro-geomorphotype map, the variability of the contribution areas was graphically modeled for the selected event, which occurred during the wet season, by using the log values of flow accumulation that better fit the contribution areas. The results allow us to identify the runoff component on hydro-chemographs for each time step and calculate a specific discharge contribution from each hydro-geomorphotype. This kind of approach could be useful when applied to similar, rainfall-dominated, forested and no-karst catchments in the Mediterranean eco-region.

Street Level Hydrology: An Urban Application of the WRF-Hydro Framework in Denver, Colorado

NASA Astrophysics Data System (ADS)

Read, L.; Hogue, T. S.; Salas, F. R.; Gochis, D.

2015-12-01

Urban flood modeling at the watershed scale carries unique challenges in routing complexity, data resolution, social and political issues, and land surface - infrastructure interactions. The ability to accurately trace and predict the flow of water through the urban landscape enables better emergency response management, floodplain mapping, and data for future urban infrastructure planning and development. These services are of growing importance as urban population is expected to continue increasing by 1.84% per year for the next 25 years, increasing the vulnerability of urban regions to damages and loss of life from floods. Although a range of watershed-scale models have been applied in specific urban areas to examine these issues, there is a trend towards national scale hydrologic modeling enabled by supercomputing resources to understand larger system-wide hydrologic impacts and feedbacks. As such it is important to address how urban landscapes can be represented in large scale modeling processes. The current project investigates how coupling terrain and infrastructure routing can improve flow prediction and flooding events over the urban landscape. We utilize the WRF-Hydro modeling framework and a high-resolution terrain routing grid with the goal of compiling standard data needs necessary for fine scale urban modeling and dynamic flood forecasting in the urban setting. The city of Denver is selected as a case study, as it has experienced several large flooding events in the last five years and has an urban annual population growth rate of 1.5%, one of the highest in the U.S. Our work highlights the hydro-informatic challenges associated with linking channel networks and drainage infrastructure in an urban area using the WRF-Hydro modeling framework and high resolution urban models for short-term flood prediction.

Output improvement of Sg. Piah run-off river hydro-electric station with a new computed river flow-based control system

NASA Astrophysics Data System (ADS)

Jidin, Razali; Othman, Bahari

2013-06-01

The lower Sg. Piah hydro-electric station is a river run-off hydro scheme with generators capable of generating 55MW of electricity. It is located 30km away from Sg. Siput, a small town in the state of Perak, Malaysia. The station has two turbines (Pelton) to harness energy from water that flow through a 7km tunnel from a small intake dam. The trait of a run-off river hydro station is small-reservoir that cannot store water for a long duration; therefore potential energy carried by the spillage will be wasted if the dam level is not appropriately regulated. To improve the station annual energy output, a new controller based on the computed river flow has been installed. The controller regulates the dam level with an algorithm based on the river flow derived indirectly from the intake-dam water level and other plant parameters. The controller has been able to maintain the dam at optimum water level and regulate the turbines to maximize the total generation output.

Hydro power flexibility for power systems with variable renewable energy sources: an IEA Task 25 collaboration: Hydro power flexibility for power systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huertas-Hernando, Daniel; Farahmand, Hossein; Holttinen, Hannele

2016-06-20

Hydro power is one of the most flexible sources of electricity production. Power systems with considerable amounts of flexible hydro power potentially offer easier integration of variable generation, e.g., wind and solar. However, there exist operational constraints to ensure mid-/long-term security of supply while keeping river flows and reservoirs levels within permitted limits. In order to properly assess the effective available hydro power flexibility and its value for storage, a detailed assessment of hydro power is essential. Due to the inherent uncertainty of the weather-dependent hydrological cycle, regulation constraints on the hydro system, and uncertainty of internal load as wellmore » as variable generation (wind and solar), this assessment is complex. Hence, it requires proper modeling of all the underlying interactions between hydro power and the power system, with a large share of other variable renewables. A summary of existing experience of wind integration in hydro-dominated power systems clearly points to strict simulation methodologies. Recommendations include requirements for techno-economic models to correctly assess strategies for hydro power and pumped storage dispatch. These models are based not only on seasonal water inflow variations but also on variable generation, and all these are in time horizons from very short term up to multiple years, depending on the studied system. Another important recommendation is to include a geographically detailed description of hydro power systems, rivers' flows, and reservoirs as well as grid topology and congestion.« less

Minimum flow unit installation at the South Edwards Hydro Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bernhardt, P.; Bates, D.

1995-12-31

Niagara Mohawk Power Corp. owns and operates the 3.3 MW South Edwards Hydro Plant in Northern New York. The FERC license for this plant requires a minimum flow release in the bypass region of the river. NMPC submitted a license amendment to the FERC to permit the addition of a minimum flow unit to take advantage of this flow. The amendment was accepted, permitting the installation of the 236 kw, 60 cfs unit to proceed. The unit was installed and commissioned in 1994.

The shallow water equations as a hybrid flow model for the numerical and experimental analysis of hydro power stations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ostermann, Lars; Seidel, Christian

2015-03-10

The numerical analysis of hydro power stations is an important method of the hydraulic design and is used for the development and optimisation of hydro power stations in addition to the experiments with the physical submodel of a full model in the hydraulic laboratory. For the numerical analysis, 2D and 3D models are appropriate and commonly used.The 2D models refer mainly to the shallow water equations (SWE), since for this flow model a large experience on a wide field of applications for the flow analysis of numerous problems in hydraulic engineering already exists. Often, the flow model is verified bymore » in situ measurements. In order to consider 3D flow phenomena close to singularities like weirs, hydro power stations etc. the development of a hybrid fluid model is advantageous to improve the quality and significance of the global model. Here, an extended hybrid flow model based on the principle of the SWE is presented. The hybrid flow model directly links the numerical model with the experimental data, which may originate from physical full models, physical submodels and in-situ measurements. Hence a wide field of application of the hybrid model emerges including the improvement of numerical models and the strong coupling of numerical and experimental analysis.« less

Exploring the dynamics of transit times and runoff source zones in a small agricultural catchment using a physically-based water flow model

NASA Astrophysics Data System (ADS)

Fleckenstein, J. H.; Yang, J.; Heidbuchel, I.; Musolff, A.

2017-12-01

Catchment-scale transit time distributions (TTDs) for discharge and residence time distributions (RTDs) of the water in storage are promising tools to characterize the discharge and mixing behavior of a catchment. TTDs and RTDs are dynamic in time, influenced by dynamic rainfall and evapotranspiration forcing, as well as changing groundwater storage in the catchment. In order to understand the links between the dynamics of TTDs and catchment mixing in an agricultural catchment in central Germany, a 3D hydrological model was set up using the fully coupled surface-subsurface numerical code HydroGeoSphere. The transient model is calibrated using discharge and groundwater level measurements, and is run for a period of 10 years from 1997 to 2007. A particle tracking tool was implemented in HydroGeoSphere to track the movement of water parcels in the subsurface, outputting TTDs of discharge and RTDs of groundwater storage at daily intervals. Results show the strong variability of the median age of discharge and median age of the water in storage, in response to the overall wetness of the catchment. Computed fractional StorAge Selection (fSAS, van der Velde et al. 2012, Rinaldo et al. 2015) functions suggest systematic changes in the preference of the catchment to discharge water of a certain age ranges from storage over the seasons: In the wet period, youngest water in storage is preferentially selected, and the preference shifts gradually to older water in storage when the catchment transitions into periods of post-wet, dry and pre-wet. Those changes are driven by distinct shifts in the dominant flow paths from deeper, slow flow paths during dry periods to faster shallow flow paths during the wet season. Changes in the shape of the fSAS functions are quantified in terms of changes in the two parameters of the Beta functions, which are used to approximate the fSAS functions. This provides an opportunity to generate quasi-continuous fSAS functions over the course of a year for the catchment. Our results provide new insights into the dynamics of TTDs and fSAS functions for a complex real-world catchment and can help to interpret the associated solute exports to the stream.

76 FR 35209 - FFP Qualified Hydro 14 LLC; Notice of Intent To File License Application, Filing of Pre...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-16

...: April 4, 2011. d. Submitted by: Free Flow Power Qualified Hydro 14 LLC (Qualified Power 14 LLC), a subsidiary of Free Flow Power Corporation. e. Name of Project: Saylorville Dam Water Power Project. f... County, Iowa. The project would occupy 1.5 acres of United States lands administered by Corps' Rock...

Hamiltonian model and dynamic analyses for a hydro-turbine governing system with fractional item and time-lag

NASA Astrophysics Data System (ADS)

Xu, Beibei; Chen, Diyi; Zhang, Hao; Wang, Feifei; Zhang, Xinguang; Wu, Yonghong

2017-06-01

This paper focus on a Hamiltonian mathematical modeling for a hydro-turbine governing system including fractional item and time-lag. With regards to hydraulic pressure servo system, a universal dynamical model is proposed, taking into account the viscoelastic properties and low-temperature impact toughness of constitutive materials as well as the occurrence of time-lag in the signal transmissions. The Hamiltonian model of the hydro-turbine governing system is presented using the method of orthogonal decomposition. Furthermore, a novel Hamiltonian function that provides more detailed energy information is presented, since the choice of the Hamiltonian function is the key issue by putting the whole dynamical system to the theory framework of the generalized Hamiltonian system. From the numerical experiments based on a real large hydropower station, we prove that the Hamiltonian function can describe the energy variation of the hydro-turbine suitably during operation. Moreover, the effect of the fractional α and the time-lag τ on the dynamic variables of the hydro-turbine governing system are explored and their change laws identified, respectively. The physical meaning between fractional calculus and time-lag are also discussed in nature. All of the above theories and numerical results are expected to provide a robust background for the safe operation and control of large hydropower stations.

Dynamics of the precessing vortex rope and its interaction with the system at Francis turbines part load operating conditions

NASA Astrophysics Data System (ADS)

Favrel, A.; Müller, A.; Landry, C.; Gomes, J.; Yamamoto, K.; Avellan, F.

2017-04-01

At part load conditions, Francis turbines experience the formation of a cavitation vortex rope at the runner outlet whose precession acts as a pressure excitation source for the hydraulic circuit. This can lead to hydro-acoustic resonances characterized by high pressure pulsations, as well as torque and output power fluctuations. This study highlights the influence of the discharge factor on both the vortex parameters and the pressure excitation source by performing Particle Image Velocimetry (PIV) and pressure measurements. Moreover, it is shown that the occurrence of hydro-acoustic resonances in cavitation conditions mainly depend on the swirl degree of the flow independently of the speed factor. Empirical laws linking both natural and precession frequencies with the operating parameters of the machine are, then, derived, enabling the prediction of resonance conditions on the complete part load operating range of the turbine.

Prediction of dynamic and aerodynamic characteristics of the centrifugal fan with forward curved blades

NASA Astrophysics Data System (ADS)

Polanský, Jiří; Kalmár, László; Gášpár, Roman

2013-12-01

The main aim of this paper is determine the centrifugal fan with forward curved blades aerodynamic characteristics based on numerical modeling. Three variants of geometry were investigated. The first, basic "A" variant contains 12 blades. The geometry of second "B" variant contains 12 blades and 12 semi-blades with optimal length [1]. The third, control variant "C" contains 24 blades without semi-blades. Numerical calculations were performed by CFD Ansys. Another aim of this paper is to compare results of the numerical simulation with results of approximate numerical procedure. Applied approximate numerical procedure [2] is designated to determine characteristics of the turbulent flow in the bladed space of a centrifugal-flow fan impeller. This numerical method is an extension of the hydro-dynamical cascade theory for incompressible and inviscid fluid flow. Paper also partially compares results from the numerical simulation and results from the experimental investigation. Acoustic phenomena observed during experiment, during numerical simulation manifested as deterioration of the calculation stability, residuals oscillation and thus also as a flow field oscillation. Pressure pulsations are evaluated by using frequency analysis for each variant and working condition.

Hydrologic enforcement of lidar DEMs

USGS Publications Warehouse

Poppenga, Sandra K.; Worstell, Bruce B.; Danielson, Jeffrey J.; Brock, John C.; Evans, Gayla A.; Heidemann, H. Karl

2014-01-01

Hydrologic-enforcement (hydro-enforcement) of light detection and ranging (lidar)-derived digital elevation models (DEMs) modifies the elevations of artificial impediments (such as road fills or railroad grades) to simulate how man-made drainage structures such as culverts or bridges allow continuous downslope flow. Lidar-derived DEMs contain an extremely high level of topographic detail; thus, hydro-enforced lidar-derived DEMs are essential to the U.S. Geological Survey (USGS) for complex modeling of riverine flow. The USGS Coastal and Marine Geology Program (CMGP) is integrating hydro-enforced lidar-derived DEMs (land elevation) and lidar-derived bathymetry (water depth) to enhance storm surge modeling in vulnerable coastal zones.

Development of a dynamic coupled hydro-geomechanical code and its application to induced seismicity

NASA Astrophysics Data System (ADS)

Miah, Md Mamun

This research describes the importance of a hydro-geomechanical coupling in the geologic sub-surface environment from fluid injection at geothermal plants, large-scale geological CO2 sequestration for climate mitigation, enhanced oil recovery, and hydraulic fracturing during wells construction in the oil and gas industries. A sequential computational code is developed to capture the multiphysics interaction behavior by linking a flow simulation code TOUGH2 and a geomechanics modeling code PyLith. Numerical formulation of each code is discussed to demonstrate their modeling capabilities. The computational framework involves sequential coupling, and solution of two sub-problems- fluid flow through fractured and porous media and reservoir geomechanics. For each time step of flow calculation, pressure field is passed to the geomechanics code to compute effective stress field and fault slips. A simplified permeability model is implemented in the code that accounts for the permeability of porous and saturated rocks subject to confining stresses. The accuracy of the TOUGH-PyLith coupled simulator is tested by simulating Terzaghi's 1D consolidation problem. The modeling capability of coupled poroelasticity is validated by benchmarking it against Mandel's problem. The code is used to simulate both quasi-static and dynamic earthquake nucleation and slip distribution on a fault from the combined effect of far field tectonic loading and fluid injection by using an appropriate fault constitutive friction model. Results from the quasi-static induced earthquake simulations show a delayed response in earthquake nucleation. This is attributed to the increased total stress in the domain and not accounting for pressure on the fault. However, this issue is resolved in the final chapter in simulating a single event earthquake dynamic rupture. Simulation results show that fluid pressure has a positive effect on slip nucleation and subsequent crack propagation. This is confirmed by running a sensitivity analysis that shows an increase in injection well distance results in delayed slip nucleation and rupture propagation on the fault.

78 FR 34090 - New Hampshire Water Resources Board, Hydro Dynamics Corporation; Notice of Transfer of Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-06

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 5379-008] New Hampshire Water Resources Board, Hydro Dynamics Corporation; Notice of Transfer of Exemption 1. By letter filed April 16, 2013, New Hampshire Water Resources Board co-exemptee and the New Hampshire Department of...

Spatial heterogeneities and variability of karst hydro-system : insights from geophysics

NASA Astrophysics Data System (ADS)

Champollion, C.; Fores, B.; Lesparre, N.; Frederic, N.

2017-12-01

Heterogeneous systems such as karsts or fractured hydro-systems are challenging for both scientist and groundwater resources management. Karsts heterogeneities prevent the comparison and moreover the combination of data representative of different scales: borehole water level can generally not be used directly to interpret spring flow dynamic for example. The spatial heterogeneity has also an impact on the temporal variability of groundwater transfer and storage. Karst hydro-systems have characteristic non linear relation between precipitation amount and discharge at the outlets with threshold effects and a large variability of groundwater transit times In the presentation, geophysical field experiments conducted in karst hydro-system in the south of France are used to investigate groundwater transfer and storage variability at a scale of a few hundred meters. We focus on the added value of both geophysical time-lapse gravity experiments and 2D ERT imaging of the subsurface heterogeneities. Both gravity and ERT results can only be interpreted with large ambiguity or some strong a priori: the relation between resistivity and water content is not unique; almost no information about the processes can be inferred from the groundwater stock variations. The present study demonstrate how the ERT and gravity field experiments can be interpreted together in a coherent scheme with less ambiguity. First the geological and hydro-meteorological context is presented. Then the ERT field experiment including the processing and the results are detailed in the section about geophysical imaging of the heterogeneities. The gravity double difference (S2D) time-lapse experiment is described in the section about geophysical monitoring of the temporal variability. The following discussion demonstrate the impact of both experiments on the interpretation in terms of processes and heterogeneities.

Enhancements to the WRF-Hydro Hydrologic Model Structure for Semi-arid Environments

NASA Astrophysics Data System (ADS)

Lahmers, T. M.; Gupta, H.; Hazenberg, P.; Castro, C. L.; Gochis, D.; Yates, D. N.; Dugger, A. L.; Goodrich, D. C.

2017-12-01

The NOAA National Water Center (NWC) implemented an operational National Water Model (NWM) in August 2016 to simulate and forecast streamflow and soil moisture throughout the Contiguous US (CONUS). The NWM is based on the WRF-Hydro hydrologic model architecture, with a 1-km resolution Noah-MP LSM grid and a 250m routing grid. The operational NWM does not currently resolve infiltration of water from the beds of ephemeral channels, which is an important component of the water balance in semi-arid environments common in many portions of the western US. This work demonstrates the benefit of a conceptual channel infiltration function in the WRF-Hydro model architecture following calibration. The updated model structure and parameters for the NWM architecture, when implemented operationally, will permit its use in flow simulation and forecasting in the southwest US, particularly for flash floods in basins with smaller drainage areas. Our channel infiltration function is based on that of the KINEROS2 semi-distributed hydrologic model, which has been tested throughout the southwest CONUS for flash flood forecasts. Model calibration utilizes the Dynamically Dimensioned Search (DDS) algorithm, and the model is calibrated using NLDAS-2 atmospheric forcing and NCEP Stage-IV precipitation. Our results show that adding channel infiltration to WRF-Hydro can produce a physically consistent hydrologic response with a high-resolution gauge based precipitation forcing dataset in the USDA-ARS Walnut Gulch Experimental Watershed. NWM WRF-Hydro is also tested for the Babocomari River, Beaver Creek, and Sycamore Creek catchments in southern and central Arizona. In these basins, model skill is degraded due to uncertainties in the NCEP Stage-IV precipitation forcing dataset.

Tree ring-based chronology of hydro-geomorphic processes as a fundament for identification of hydro-meteorological triggers in the Hrubý Jeseník Mountains (Central Europe).

PubMed

Tichavský, Radek; Šilhán, Karel; Tolasz, Radim

2017-02-01

Hydro-geomorphic processes have significantly influenced the recent development of valley floors, river banks and depositional forms in mountain environments, have caused considerable damage to manmade developments and have disrupted forest management. Trees growing along streams are affected by the transported debris mass and provide valuable records of debris flow/flood histories in their tree-ring series. Dendrogeomorphic approaches are currently the most accurate methods for creating a chronology of the debris flow/flood events in forested catchments without any field-monitoring or a stream-gauging station. Comprehensive studies focusing on the detailed chronology of hydro-geomorphic events and analysis of meteorological triggers and weather circulation patterns are still lacking for the studied area. We provide a spatio-temporal reconstruction of hydro-geomorphic events in four catchments of the Hrubý Jeseník Mountains, Czech Republic, with an analysis of their triggering factors using meteorological data from four nearby rain gauges. Increment cores from 794 coniferous trees (Picea abies [L.] Karst.) allowed the identification of 40 hydro-geomorphic events during the period of 1889-2013. Most of the events can be explained by extreme daily rainfalls (≥50mm) occurring in at least one rain gauge. However, in several cases, there was no record of extreme precipitation at rain gauges during the debris flow/flood event year, suggesting extremely localised rainstorms at the mountain summits. We concluded that the localisation, intensity and duration of rainstorms; antecedent moisture conditions; and amount of available sediments all influenced the initiation, spatial distribution and characteristics of hydro-geomorphic events. The most frequent synoptic situations responsible for the extreme rainfalls (1946-2015) were related to the meridional atmospheric circulation pattern. Our results enhance current knowledge of the occurrences and triggers of debris flows/floods in the Central European mountains in transition between temperate oceanic and continental climatic conditions and may prompt further research of these phenomena in the Eastern Sudetes in general. Copyright © 2016 Elsevier B.V. All rights reserved.

Nonlinear Synergistic Emergence and Predictability in Complex Systems: Theory and Hydro-Climatic Applications

NASA Astrophysics Data System (ADS)

Perdigão, Rui A. P.; Hall, Julia; Pires, Carlos A. L.; Blöschl, Günter

2017-04-01

Classical and stochastic dynamical system theories assume structural coherence and dynamic recurrence with invariants of motion that are not necessarily so. These are grounded on the unproven assumption of universality in the dynamic laws derived from statistical kinematic evaluation of non-representative empirical records. As a consequence, the associated formulations revolve around a restrictive set of configurations and intermittencies e.g. in an ergodic setting, beyond which any predictability is essentially elusive. Moreover, dynamical systems are fundamentally framed around dynamic codependence among intervening processes, i.e. entail essentially redundant interactions such as couplings and feedbacks. That precludes synergistic cooperation among processes that, whilst independent from each other, jointly produce emerging dynamic behaviour not present in any of the intervening parties. In order to overcome these fundamental limitations, we introduce a broad class of non-recursive dynamical systems that formulate dynamic emergence of unprecedented states in a fundamental synergistic manner, with fundamental principles in mind. The overall theory enables innovations to be predicted from the internal system dynamics before any a priori information is provided about the associated dynamical properties. The theory is then illustrated to anticipate, from non-emergent records, the spatiotemporal emergence of multiscale hyper chaotic regimes, critical transitions and structural coevolutionary changes in synthetic and real-world complex systems. Example applications are provided within the hydro-climatic context, formulating and dynamically forecasting evolving hydro-climatic distributions, including the emergence of extreme precipitation and flooding in a structurally changing hydro-climate system. Validation is then conducted with a posteriori verification of the simulated dynamics against observational records. Agreement between simulations and observations is confirmed with robust nonlinear information diagnostics.

75 FR 6018 - Boyce Hydro Power, LLC; Notice of Application for Amendment of License and Soliciting Comments...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-05

.... d. Applicant: Boyce Hydro Power, LLC (BHP). e. Name of Project: Edenville Hydroelectric Project. f... construct the footings and first lift of the retaining walls. BHP states that shutting off the bypass flow...

Coupled long term simulation of reach scale water and heat fluxes across the river groundwater interface and hyporheic temperature dynamics

NASA Astrophysics Data System (ADS)

Munz, Matthias; Oswald, Sascha E.; Schmidt, Christian

2017-04-01

Flow pattern and seasonal as well as diurnal temperature variations control ecological and biogeochemical conditions in hyporheic sediments. In particular, hyporheic temperatures have a great impact on many microbial processes. In this study we used 3-D coupled water flow and heat transport simulations applying the HydroGeoSphere code in combination with high frequent observations of hydraulic heads and temperatures for quantifying reach scale water and heat flux across the river groundwater interface and hyporheic temperature dynamics of a lowland gravel-bed river. The magnitude and dynamics of simulated temperatures matched the observed with an average mean absolute error of 0.7 °C and an average Nash Sutcliffe Efficiency of 0.87. Our results highlight that the average temperature in the hyporheic zone follows the temperature in the river which is characterized by distinct seasonal and daily temperature cycles. Individual hyporheic flow path temperature substantially varies around the average hyporheic temperature. Hyporheic flow path temperature was found to strongly depend on the flow path residence time and the temperature gradient between river and groundwater; that is, in winter the average flow path temperature of long flow paths is potentially higher compared to short flow paths. Based on the simulation results we derived a general empirical relationship, estimating the influence of hyporheic flow path residence time on hyporheic flow path temperature. Furthermore we used an empirical temperature relationship between effective temperature and respiration rate to estimate the influence of hyporheic flow path residence time and temperature on hyporheic oxygen consumption. This study highlights the relation between complex hyporheic temperature patterns, hyporheic residence times and their implications on temperature sensitive biogeochemical processes.

Unstable plastic deformation of ultrafine-grained copper at 0.5 K

NASA Astrophysics Data System (ADS)

Isaev, N. V.; Grigorova, T. V.; Shumilin, S. E.; Polishchuk, S. S.; Davydenko, O. A.

2017-12-01

We investigate the relation between the strain-hardening rate and flow instability of polycrystalline Cu-OF deformed by tension at a constant rate in a liquid 3He atmosphere. The microstructure of the ultrafine-grained crystal, obtained by the equal-channel angular hydro-extrusion method, was varied by annealing at recovery and recrystallization temperatures and was monitored by x-ray diffraction. It is shown that that the flow instability, manifesting itself as macroscopic stress serrations on the tension curve, appears at a threshold tension sufficient for activation of a dynamic recovery that leads to a decrease of the strain-hardening coefficient. We discuss the effect of grain size and the initial dislocation density on the evolution of the dislocation structure that determines the scale and the statistical properties of the flow instability in the investigated crystals at low temperature.

Hydro-power production and fish habitat suitability: Assessing impact and effectiveness of ecological flows at regional scale

NASA Astrophysics Data System (ADS)

Ceola, Serena; Pugliese, Alessio; Ventura, Matteo; Galeati, Giorgio; Montanari, Alberto; Castellarin, Attilio

2018-06-01

Anthropogenic activities along streams and rivers may be of major concern for fluvial ecosystems, e.g. abstraction and impoundment of surface water resources may profoundly alter natural streamflow regimes. An established approach aimed at preserving the behavior and distribution of fluvial species relies on the definition of ecological flows (e-flows) downstream of dams and diversion structures. E-flow prescriptions are usually set by basin authorities at regional scale, often without a proper assessment of their impact and effectiveness. On the contrary, we argue that e-flows should be identified on the basis of (i) regional and (ii) quantitative assessments. We focus on central Italy and evaluate the effects on habitat suitability of two near-threatened fish species (i.e. Barbel and Chub) and an existing hydro-power network when shifting from the current time-invariant e-flow policy to a tighter and seasonally-varying soon-to-be-enforced one. Our example clearly shows that: (a) quantitative regional scale assessments are viable even when streamflow observations are entirely missing at study sites; (b) aprioristic e-flows policies may impose releases that exceed natural streamflows for significantly long time intervals (weeks, or months); (c) unduly tightening e-flow policies may heavily impact regional hydro-power productivity (15% and 42% losses on annual and seasonal basis, respectively), yet resulting in either marginal or negligible improvements of fluvial ecosystem.

Regional statistical assessment of WRF-Hydro and IFC Model stream Flow uncertainties over the State of Iowa

NASA Astrophysics Data System (ADS)

ElSaadani, M.; Quintero, F.; Goska, R.; Krajewski, W. F.; Lahmers, T.; Small, S.; Gochis, D. J.

2015-12-01

This study examines the performance of different Hydrologic models in estimating peak flows over the state of Iowa. In this study I will compare the output of the Iowa Flood Center (IFC) hydrologic model and WRF-Hydro (NFIE configuration) to the observed flows at the USGS stream gauges. During the National Flood Interoperability Experiment I explored the performance of WRF-Hydro over the state of Iowa using different rainfall products and the resulting hydrographs showed a "flashy" behavior of the model output due to lack of calibration and bad initial flows due to short model spin period. I would like to expand this study by including a second well established hydrologic model and include more rain gauge vs. radar rainfall direct comparisons. The IFC model is expected to outperform WRF-Hydro's out of the box results, however, I will test different calibration options for both the Noah-MP land surface model and RAPID, which is the routing component of the NFIE-Hydro configuration, to see if this will improve the model results. This study will explore the statistical structure of model output uncertainties across scales (as a function of drainage areas and/or stream orders). I will also evaluate the performance of different radar-based Quantitative Precipitation Estimation (QPE) products (e.g. Stage IV, MRMS and IFC's NEXRAD based radar rainfall product. Different basins will be evaluated in this study and they will be selected based on size, amount of rainfall received over the basin area and location. Basin location will be an important factor in this study due to our prior knowledge of the performance of different NEXRAD radars that cover the region, this will help observe the effect of rainfall biases on stream flows. Another possible addition to this study is to apply controlled spatial error fields to rainfall inputs and observer the propagation of these errors through the stream network.

Space and time reconstruction of the precessing vortex core in Francis turbine draft tube by 2D-PIV

NASA Astrophysics Data System (ADS)

Favrel, A.; Müller, A.; Landry, C.; Yamamoto, K.; Avellan, F.

2016-11-01

Francis turbines operating at part load conditions experience the development of a high swirling flow at the runner outlet, giving rise to the development of a cavitation precessing vortex rope in the draft tube. The latter acts as an excitation source for the hydro-mechanical system and may jeopardize the system stability if resonance conditions are met. Although many aspects of the part load issue have been widely studied in the past, the accurate stability analysis of hydro-power plants remains challenging. A better understanding of the vortex rope dynamics in a wide range of operating conditions is an important step towards the prediction and the transposition of the pressure fluctuations from reduced to prototype scale. For this purpose, an investigation of the flow velocity fields at the outlet of a Francis turbine reduced scale physical model operating at part load conditions is performed by means of 2D-PIV in three different horizontal cross-sections of the draft tube cone. The measurements are performed in cavitation-free conditions for three values of discharge factor, comprised between 60% and 81% of the value at the Best Efficiency Point. The present article describes a detailed methodology to properly recover the evolution of the velocity fields during one precession cycle by means of phase averaging. The vortex circulation is computed and the vortex trajectory over one typical precession period is finally recovered for each operating point. It is notably shown that below a given value of the discharge factor, the vortex dynamics abruptly change and loose its periodicity and coherence.

Quantifying the drivers of water security risks in a complex northern deltaic ecosystem

NASA Astrophysics Data System (ADS)

Rokaya, P.; Wheater, H. S.; Lindenschmidt, K. E.

2017-12-01

There is still a need for improved, scientific evaluations of potential impacts of a changing flow regime on the northern deltaic ecosystems. This is particularly the case for the Slave River Delta (SRD) which is believed to be drying. Although streamflow regulation in the major headwater tributary and climate change have been presented as major contributors of hydro-ecological change in the SRD, a wide range of drivers such as large scale water withdrawal, land-use change and flow modulation by the upstream delta (i.e. the Peace-Athabasca Delta) could pose challenges to water security. However, limited numbers of studies with inadequate data make it difficult to understand the principal drivers of the hydro-ecological changes. One of the least explored drivers is the upstream delta which attenuates the peak flows, retains the floodwater and reduces the downstream flood intensity. This can have significant impact on the productivity and ecological diversity of the SRD, which are governed by water and nutrient-rich sediment supplied during flood events. Thus, the Slave River basin presents a complex river system where multiple drivers are in interplay resulting in a different (new) flow regime. However, any river flow alterations could significantly affect this ecologically and socio-economically delicate ecosystem. In this study, we investigate the critical challenges related to water security in a complex deltaic ecosystem, quantifying the relative impacts of climate change, human interventions and the upstream delta on the SRD. We demonstrate that the sustainability issues of northern deltaic systems are dynamic, complex and multi-faceted, and require an understanding of intricate relationships and feedback mechanisms between human and natural systems.

Hydro-mechanical mechanism and thresholds of rainfall-induced unsaturated landslides

NASA Astrophysics Data System (ADS)

Yang, Zongji; Lei, Xiaoqin; Huang, Dong; Qiao, Jianping

2017-04-01

The devastating Ms 8 Wenchuan earthquake in 2008 created the greatest number of co-seismic mountain hazards ever recorded in China. However, the dynamics of rainfall induced mass remobilization and transport deposits after giant earthquake are not fully understood. Moreover, rainfall intensity and duration (I-D) methods are the predominant early warning indicators of rainfall-induced landslides in post-earthquake region, which are a convenient and straight-forward way to predict the hazards. However, the rainfall-based criteria and thresholds are generally empirical and based on statistical analysis,consequently, they ignore the failure mechanisms of the landslides. This study examines the mechanism and hydro-mechanical behavior and thresholds of these unsaturated deposits under the influence of rainfall. To accomplish this, in situ experiments were performed in an instrumented landslide deposit, The field experimental tests were conducted on a natural co-seismic fractured slope to 1) simulate rainfall-induced shallow failures in the depression channels of a debris flow catchment in an earthquake-affected region, 2)explore the mechanisms and transient processes associated with hydro-mechanical parameter variations in response to the infiltration of rainfall, and 3) identify the hydrologic parameter thresholds and critical criteria of gravitational erosion in areas prone to mass remobilization as a source of debris flows. These experiments provided instrumental evidence and directly proved that post-earthquake rainfall-induced mass remobilization occurred under unsaturated conditions in response to transient rainfall infiltration, and revealed the presence of transient processes and the dominance of preferential flow paths during rainfall infiltration. A hydro-mechanical method was adopted for the transient hydrologic process modelling and unsaturated slope stability analysis. and the slope failures during the experimental test were reproduced by the model, indicating that the decrease in matrix suction and increase in moisture content in response to rainfall infiltration contributed greatly to post-earthquake shallow mass movement. Thus, a threshold model for the initiation of mass remobilization is proposed based on correlations between slope stability and volumetric water content and matrix suction As a complement to rainfall-based early warning strategies, the water content and suction threshold models based on the water infiltration induced slope failure mechanism. the proposed method are expected to improve the accuracy of prediction and early warnings of post-earthquake mountain hazards

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rehder, J.B.

The project focuses on an appropriate technology for small-scale hydro power: floating waterwheels and turbines. For background, relic and existing systems such as early floating mills, traditional Amish waterwheels, and micro-hydro systems are examined. In the design phase of the project, new designs for Floating Hydro Power Systems include: an analysis of floatation materials and systems; a floating undershot waterwheel design; a floating cylinder (fiberglass storage tank) design; a submerged tube design; and a design for a floating platform with submerged propellers. Finally, in the applications phase, stream flow data from East Tennessee streams are used in a discussion ofmore » the potential applications of floating hydro power systems in small streams.« less

Microstructure Evolution and Flow Stress Model of a 20Mn5 Hollow Steel Ingot during Hot Compression.

PubMed

Liu, Min; Ma, Qing-Xian; Luo, Jian-Bin

2018-03-21

20Mn5 steel is widely used in the manufacture of heavy hydro-generator shaft due to its good performance of strength, toughness and wear resistance. However, the hot deformation and recrystallization behaviors of 20Mn5 steel compressed under high temperature were not studied. In this study, the hot compression experiments under temperatures of 850-1200 °C and strain rates of 0.01/s-1/s are conducted using Gleeble thermal and mechanical simulation machine. And the flow stress curves and microstructure after hot compression are obtained. Effects of temperature and strain rate on microstructure are analyzed. Based on the classical stress-dislocation relation and the kinetics of dynamic recrystallization, a two-stage constitutive model is developed to predict the flow stress of 20Mn5 steel. Comparisons between experimental flow stress and predicted flow stress show that the predicted flow stress values are in good agreement with the experimental flow stress values, which indicates that the proposed constitutive model is reliable and can be used for numerical simulation of hot forging of 20Mn5 hollow steel ingot.

Effects of Hydrologic Restoration on Flood Resilience and Sediment Dynamics of Urban Creeks in the UK and USA

NASA Astrophysics Data System (ADS)

Wright, N.

2015-12-01

Hydrologic restoration in urban creeks is increasingly regarded as a more sustainable option than traditional grey infrastructures in many countries including the UK and USA. Hydrologic restoration aims to recreate naturally oriented hydro-morphodynamic processes while adding ecological and amenity value to a river corridor. Nevertheless, the long-term hydraulic performance of river restorations is incompletely understood. The aim of this research was to investigate the long-term effects of river restoration on the water storage, flood attenuation and sediment dynamics of two urban creeks through detailed hydro-morphodynamic modelling. The first case study is based on Johnson Creek located at Portland, Oregon, USA, and the second case based on Ouseburn River in Newcastle upon Tyne, N.E. England. This study focuses on the downstream of the Johnson Creek, where creek is reconnected to a restored East Lents floodplain of 0.28 km2. In order to offset the increased urban runoff in the Ouseburn catchment, a number of attenuation ponds were implemented along the river. In this study, an integrated 1D and 2D flood model (ISIS - TUFLOW) and the recently updated layer-based hydro-morphodynamic model have been used to understand the long-term impacts of these restorations on the flood and sediment dynamics. The event-based simulations (500 year, 100 year, 50 year, 10 year and 5 year), as well as the continuous simulations based on the historical flow datasets were systematically undertaken. Simulation results showed that the flood storage as a result of river restoration attenuate the flood peak by up to 25% at the downstream. Results also indicated that about 30% of the sediments generated from the upstream deposited in the resorted regions. The spatial distribution and amount of short and long-term sediment deposition on the floodplain and pond are demonstrated, and the resulting potential loss of the flood storage capacity are analysed and discussed.

Glacier-surge mechanisms promoted by a hydro-thermodynamic feedback to summer melt

NASA Astrophysics Data System (ADS)

Dunse, T.; Schellenberger, T.; Hagen, J. O.; Kääb, A.; Schuler, T. V.; Reijmer, C. H.

2015-02-01

Mass loss from glaciers and ice sheets currently accounts for two-thirds of the observed global sea-level rise and has accelerated since the 1990s, coincident with strong atmospheric warming in the polar regions. Here we present continuous GPS measurements and satellite synthetic-aperture-radar-based velocity maps from Basin-3, the largest drainage basin of the Austfonna ice cap, Svalbard. Our observations demonstrate strong links between surface-melt and multiannual ice-flow acceleration. We identify a hydro-thermodynamic feedback that successively mobilizes stagnant ice regions, initially frozen to their bed, thereby facilitating fast basal motion over an expanding area. By autumn 2012, successive destabilization of the marine terminus escalated in a surge of Basin-3. The resulting iceberg discharge of 4.2±1.6 Gt a-1 over the period April 2012 to May 2013 triples the calving loss from the entire ice cap. With the seawater displacement by the terminus advance accounted for, the related sea-level rise contribution amounts to 7.2±2.6 Gt a-1. This rate matches the annual ice-mass loss from the entire Svalbard archipelago over the period 2003-2008, highlighting the importance of dynamic mass loss for glacier mass balance and sea-level rise. The active role of surface melt, i.e. external forcing, contrasts with previous views of glacier surges as purely internal dynamic instabilities. Given sustained climatic warming and rising significance of surface melt, we propose a potential impact of the hydro-thermodynamic feedback on the future stability of ice-sheet regions, namely at the presence of a cold-based marginal ice plug that restricts fast drainage of inland ice. The possibility of large-scale dynamic instabilities such as the partial disintegration of ice sheets is acknowledged but not quantified in global projections of sea-level rise.

Experimental Hydro-Mechanical Characterization of Full Load Pressure Surge in Francis Turbines

NASA Astrophysics Data System (ADS)

Müller, A.; Favrel, A.; Landry, C.; Yamamoto, K.; Avellan, F.

2017-04-01

Full load pressure surge limits the operating range of hydro-electric generating units by causing significant power output swings and by compromising the safety of the plant. It appears during the off-design operation of hydraulic machines, which is increasingly required to regulate the broad integration of volatile renewable energy sources into the existing power network. The underlying causes and governing physical mechanisms of this instability were investigated in the frame of a large European research project and this paper documents the main findings from two experimental campaigns on a reduced scale model of a Francis turbine. The multi-phase flow in the draft tube is characterized by Particle Image Velocimetry, Laser Doppler Velocimetry and high-speed visualizations, along with synchronized measurements of the relevant hydro-mechanical quantities. The final result is a comprehensive overview of how the unsteady draft tube flow and the mechanical torque on the runner shaft behave during one mean period of the pressure oscillation, thus defining the unstable fluid-structure interaction responsible for the power swings. A discussion of the root cause is initiated, based on the state of the art. Finally, the latest results will enable a validation of recent RANS flow simulations used for determining the key parameters of hydro-acoustic stability models.

Recovery Act. Development and Validation of an Advanced Stimulation Prediction Model for Enhanced Geothermal System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutierrez, Marte

The research project aims to develop and validate an advanced computer model that can be used in the planning and design of stimulation techniques to create engineered reservoirs for Enhanced Geothermal Systems. The specific objectives of the proposal are to: 1) Develop a true three-dimensional hydro-thermal fracturing simulator that is particularly suited for EGS reservoir creation. 2) Perform laboratory scale model tests of hydraulic fracturing and proppant flow/transport using a polyaxial loading device, and use the laboratory results to test and validate the 3D simulator. 3) Perform discrete element/particulate modeling of proppant transport in hydraulic fractures, and use the resultsmore » to improve understand of proppant flow and transport. 4) Test and validate the 3D hydro-thermal fracturing simulator against case histories of EGS energy production. 5) Develop a plan to commercialize the 3D fracturing and proppant flow/transport simulator. The project is expected to yield several specific results and benefits. Major technical products from the proposal include: 1) A true-3D hydro-thermal fracturing computer code that is particularly suited to EGS, 2) Documented results of scale model tests on hydro-thermal fracturing and fracture propping in an analogue crystalline rock, 3) Documented procedures and results of discrete element/particulate modeling of flow and transport of proppants for EGS applications, and 4) Database of monitoring data, with focus of Acoustic Emissions (AE) from lab scale modeling and field case histories of EGS reservoir creation.« less

Recovery Act. Development and Validation of an Advanced Stimulation Prediction Model for Enhanced Geothermal Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutierrez, Marte

2013-12-31

This research project aims to develop and validate an advanced computer model that can be used in the planning and design of stimulation techniques to create engineered reservoirs for Enhanced Geothermal Systems. The specific objectives of the proposal are to; Develop a true three-dimensional hydro-thermal fracturing simulator that is particularly suited for EGS reservoir creation; Perform laboratory scale model tests of hydraulic fracturing and proppant flow/transport using a polyaxial loading device, and use the laboratory results to test and validate the 3D simulator; Perform discrete element/particulate modeling of proppant transport in hydraulic fractures, and use the results to improve understandmore » of proppant flow and transport; Test and validate the 3D hydro-thermal fracturing simulator against case histories of EGS energy production; and Develop a plan to commercialize the 3D fracturing and proppant flow/transport simulator. The project is expected to yield several specific results and benefits. Major technical products from the proposal include; A true-3D hydro-thermal fracturing computer code that is particularly suited to EGS; Documented results of scale model tests on hydro-thermal fracturing and fracture propping in an analogue crystalline rock; Documented procedures and results of discrete element/particulate modeling of flow and transport of proppants for EGS applications; and Database of monitoring data, with focus of Acoustic Emissions (AE) from lab scale modeling and field case histories of EGS reservoir creation.« less

Simulation of the Process of Arc Energy-Effect in High Voltage Auto-Expansion SF6 Circuit Breaker

NASA Astrophysics Data System (ADS)

Rong, Mingzhe; Yang, Qian; Fan, Chunduo

2005-12-01

A new magnetic hydro-dynamics (MHD) model of arc in H.V. auto-expansion SF6 circuit breaker that takes into consideration nozzle ablation due to both radiation and thermal conduction is presented in this paper. The effect of PTFE (polytetrafluorethylene) vapor is considered in the mass, momentum and energy conservation equations of the constructed model. Then, the gas flow fields with and without conduction considered are simulated. By comparing the aforementioned two results, it is indicated that the arc's maximal temperature with conduction considered is 90 percent of that without considering conduction.

Characterizing observed circulation patterns within a bay using HF radar and numerical model simulations

NASA Astrophysics Data System (ADS)

O'Donncha, Fearghal; Hartnett, Michael; Nash, Stephen; Ren, Lei; Ragnoli, Emanuele

2015-02-01

In this study, High Frequency Radar (HFR), observations in conjunction with numerical model simulations investigate surface flow dynamics in a tidally-active, wind-driven bay; Galway Bay situated on the West coast of Ireland. Comparisons against ADCP sensor data permit an independent assessment of HFR and model performance, respectively. Results show root-mean-square (rms) differences in the range 10 - 12cm/s while model rms equalled 12 - 14cm/s. Subsequent analysis focus on a detailed comparison of HFR and model output. Harmonic analysis decompose both sets of surface currents based on distinct flow process, enabling a correlation analysis between the resultant output and dominant forcing parameters. Comparisons of barotropic model simulations and HFR tidal signal demonstrate consistently high agreement, particularly of the dominant M2 tidal signal. Analysis of residual flows demonstrate considerably poorer agreement, with the model failing to replicate complex flows. A number of hypotheses explaining this discrepancy are discussed, namely: discrepancies between regional-scale, coastal-ocean models and globally-influenced bay-scale dynamics; model uncertainties arising from highly-variable wind-driven flows across alarge body of water forced by point measurements of wind vectors; and the high dependence of model simulations on empirical wind-stress coefficients. The research demonstrates that an advanced, widely-used hydro-environmental model does not accurately reproduce aspects of surface flow processes, particularly with regards wind forcing. Considering the significance of surface boundary conditions in both coastal and open ocean dynamics, the viability of using a systematic analysis of results to improve model predictions is discussed.

Experimental and numerical investigation of hydro power generator ventilation

NASA Astrophysics Data System (ADS)

Jamshidi, H.; Nilsson, H.; Chernoray, V.

2014-03-01

Improvements in ventilation and cooling offer means to run hydro power generators at higher power output and at varying operating conditions. The electromagnetic, frictional and windage losses generate heat. The heat is removed by an air flow that is driven by fans and/or the rotor itself. The air flow goes through ventilation channels in the stator, to limit the electrical insulation temperatures. The temperature should be kept limited and uniform in both time and space, avoiding thermal stresses and hot-spots. For that purpose it is important that the flow of cooling air is distributed uniformly, and that flow separation and recirculation are minimized. Improvements of the air flow properties also lead to an improvement of the overall efficiency of the machine. A significant part of the windage losses occurs at the entrance of the stator ventilation channels, where the air flow turns abruptly from tangential to radial. The present work focuses exclusively on the air flow inside a generator model, and in particular on the flow inside the stator channels. The generator model design of the present work is based on a real generator that was previously studied. The model is manufactured taking into consideration the needs of both the experimental and numerical methodologies. Computational Fluid Dynamics (CFD) results have been used in the process of designing the experimental setup. The rotor and stator are manufactured using rapid-prototyping and plexi-glass, yielding a high geometrical accuracy, and optical experimental access. A special inlet section is designed for accurate air flow rate and inlet velocity profile measurements. The experimental measurements include Particle Image Velocimetry (PIV) and total pressure measurements inside the generator. The CFD simulations are performed based on the OpenFOAM CFD toolbox, and the steady-state frozen rotor approach. Specific studies are performed, on the effect of adding "pick-up" to spacers, and the effects of the inlet fan blades on the flow rate through the model. The CFD results capture the experimental flow details to a reasonable level of accuracy.

Numerical investigation of unsteady cavitation around a NACA 66 hydrofoil using OpenFOAM

NASA Astrophysics Data System (ADS)

Hidalgo, V. H.; Luo, X. W.; Escaler, X.; Ji, J.; Aguinaga, A.

2014-03-01

The prediction and control of cavitation damage in pumps, propellers, hydro turbines and fluid machinery in general is necessary during the design stage. The present paper deals with a numerical investigation of unsteady cloud cavitation around a NACA 66 hydrofoil. The current study is focused on understanding the dynamic pressures generated during the cavity collapses as a fundamental characteristic in cavitation erosion. A 2D and 3D unsteady flow simulation has been carried out using OpenFOAM. Then, Paraview and Python programming language have been used to characterize dynamic pressure field. Adapted Large Eddy Simulation (LES) and Zwart cavitation model have been implemented to improve the analysis of cloud motion and to visualize the bubble expansions. Additional results also confirm the correlation between cavity formation and generated pressures.

Adapting regional watershed management to climate change in Bavaria and Québec

NASA Astrophysics Data System (ADS)

Ludwig, Ralf; Muerth, Markus; Schmid, Josef; Jobst, Andreas; Caya, Daniel; Gauvin St-Denis, Blaise; Chaumont, Diane; Velazquez, Juan-Alberto; Turcotte, Richard; Ricard, Simon

2013-04-01

The international research project QBic3 (Quebec-Bavarian Collaboration on Climate Change) aims at investigating the potential impacts of climate change on the hydrology of regional scale catchments in Southern Quebec (Canada) and Bavaria (Germany). For this purpose, a hydro-meteorological modeling chain has been established, applying climatic forcing from both dynamical and statistical climate model data to an ensemble of hydrological models of varying complexity. The selection of input data, process descriptions and scenarios allows for the inter-comparison of the uncertainty ranges on selected runoff indicators; a methodology to display the relative importance of each source of uncertainty is developed and results for past runoff (1971-2000) and potential future changes (2041-2070) are obtained. Finally, the impact of hydrological changes on the operational management of dams, reservoirs and transfer systems is investigated and shown for the Bavarian case studies, namely the potential change in i) hydro-power production for the Upper Isar watershed and ii) low flow augmentation and water transfer rates at the Donau-Main transfer system in Central Franconia. Two overall findings will be presented and discussed in detail: a) the climate change response of selected hydrological indicators, especially those related to low flows, is strongly affected by the choice of the hydrological model. It can be shown that an assessment of the changes in the hydrological cycle is best represented by a complex physically based hydrological model, computationally less demanding models (usually simple, lumped and conceptual) can give a significant level of trust for selected indicators. b) the major differences in the projected climate forcing stemming from the ensemble of dynamic climate models (GCM/RCM) versus the statistical-stochastical WETTREG2010 approach. While the dynamic ensemble reveals a moderate modification of the hydrological processes in the investigated catchments, the WETTREG2010 driven runs show a severe detraction for all water operations, mainly related to a strong decline in projected precipitation in all seasons (except winter).

Urban water-quality modelling: implementing an extension to Multi-Hydro platform for real case studies

NASA Astrophysics Data System (ADS)

Hong, Yi; Giangola-Murzyn, Agathe; Bonhomme, Celine; Chebbo, Ghassan; Schertzer, Daniel

2015-04-01

During the last few years, the physically based and fully distributed numerical platform Multi-Hydro (MH) has been developed to simulate hydrological behaviours in urban/peri-urban areas (El-Tabach et al. , 2009 ; Gires et al., 2013 ; Giangola-Murzyn et al., 2014). This hydro-dynamical platform is open-access and has a modular structure, which is designed to be easily scalable and transportable, in order to simulate the dynamics and complex interactions of the water cycle processes in urban or peri-urban environment (surface hydrology, urban groundwater infrastructures and infiltration). Each hydrological module relies on existing and widely validated open source models, such as TREX model (Velleux, 2005) for the surface module, SWMM model (Rossman, 2010) for the drainage module and VS2DT model (Lappala et al., 1987) for the soil module. In our recent studies, an extension of MH has been set up by connecting the already available water-quality computational components among different modules, to introduce a pollutant transport modelling into the hydro-dynamical platform. As for the surface module in two-dimensions, the concentration of particles in flow is expressed by sediment advection equation, the settling of suspended particles is calculated with a simplified settling velocity formula, while the pollutant wash-off from a given land-use is represented as a mass rate of particle removal from the bottom boundary over time, based on transport capacity, which is computed by a modified form of Universal Soil Loss Equation (USLE). Considering that the USLE is originally conceived to predict soil losses caused by runoff in agriculture areas, several adaptations were needed to use it for urban areas, such as the alterations of USLE parameters according to different criterions, the definition of the appropriate initial dust thickness corresponding to various land-uses, etc. Concerning the drainage module, water quality routing within pipes assumes that the conduit behaves as a continuously stirred tank reactor. This extension of Multi-Hydro was tested on two peri-urban catchments located near Paris, the Villecresnes (France, 0.7 km²) and the Le Perreux-sur-Marne (France, 0.2 km²). As the Villecresnes had been analyzed within several European projects (FP7 SMARTeST, KIC-Climate BlueGreenDream, Interreg RainGain), the robustness of the new extension of MH was firstly tested on this basin by comparing the water quantity simulation outcomes with the results already obtained in previous works. Benefiting from the large datasets that are collected in the framework of the ANR (French National Agency for Research) Trafipollu project, the water quality modelling performance of the extension was then illustrated on the catchment of Le Perreux-sur-Marne.

TECHNOLOGY EVALUATION REPORT, HYDROTECHNICS IN SITU FLOW SENSOR

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) Program evaluated performance of HydroTechnics, Inc. flow sensors in measuring the three-dimensional flow pattern created by operation of the Wasatch Environmental, Inc. (WEI) ground...

Development of a project on North Unit Irrigation District’s Main Canal at the Monroe Drop, using a novel low-head hydropower technology called the SLH100

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, Abraham; Schneider, Gia; McKinstry, Katherine

Natel Energy is a low­-head, distributed hydropower company based out of Alameda, CA. Natel manufactures and sells proprietary hydroelectric turbines called hydroEngines® that are suitable for low-­head, high-­flow settings, and range from 30kW to 1 MW of capacity per unit. Natel’s hydroEngine is a state­-of­the-­art two stage impulse turbine, using blades mounted symmetrically on two belts perpendicular to the axis of travel, and using linearly­-moving foils, rather than a rotor, to enable efficient conversion of kinetic energy of large volumes of water at low head with no risk of cavitation. In addition, the hydroEngine can be installed at or abovemore » tailwater level, reducing the excavation necessary to build the powerhouse and thus reducing total installed cost and project footprint. Thus, the hydroEngine technology enables a new generation of small hydro installations with low cost of project development, fish-­friendly operations, and small project footprint. In September of 2015, Natel Energy formally commissioned its first project installation in Madras, Oregon, installing 1 SLH100 turbine at an existing drop structure on the North Unit Irrigation District (NUID) Main Canal. The water falls between 13.5 feet to 16.5 feet at this structure, depending on flow. The plant has an installed capacity of 250 kW and an expected annual generation of approximately 873 MWh. The plant operates at an annual capacity factor of 40%, and a capacity factor over the irrigation season, or period of available flow, of 80%. Annual capacity factor is calculated as a percentage of plant operating hours relative to a total of 8,760 hours in a year; because the irrigation canal in which the Project is located only runs water from April to October, the available flow capacity factor is higher. Net greenhouse gas reductions from the Monroe Project are estimated to be 602 tCO2/year. The purpose of this report is to provide an overview of the specifications for Natel’s first commissioned project, the project development process, the plant’s performance, project costs, and the construction, installation, and commissioning process. We hope that this report will provide useful context for assessment of the hydroEngine as a viable technology choice for future distributed, low-­head hydropower projects, as well as assessment of the bankability, performance, reliability, and cost of the hydroEngine.« less

Sensitivity analysis of a new dual-porosity hydroloigcal model coupled with the SOSlope model for the numerical simulations of rainfall triggered shallow landslides.

NASA Astrophysics Data System (ADS)

Schwarz, Massimiliano; Cohen, Denis

2017-04-01

Morphology and extent of hydrological pathways, in combination with the spatio-temporal variability of rainfall events and the heterogeneities of hydro-mechanical properties of soils, has a major impact on the hydrological conditions that locally determine the triggering of shallow landslides. The coupling of these processes at different spatial scales is an enormous challenge for slope stability modeling at the catchment scale. In this work we present a sensitivity analysis of a new dual-porosity hydrological model implemented in the hydro-mechanical model SOSlope for the modeling of shallow landslides on vegetated hillslopes. The proposed model links the calculation of the saturation dynamic of preferential flow-paths based on hydrological and topographical characteristics of the landscape to the hydro-mechanical behavior of the soil along a potential failure surface due to the changes of soil matrix saturation. Furthermore, the hydro-mechanical changes of soil conditions are linked to the local stress-strain properties of the (rooted-)soil that ultimately determine the force redistribution and related deformations at the hillslope scale. The model considers forces to be redistributed through three types of solicitations: tension, compression, and shearing. The present analysis shows how the conditions of deformation due to the passive earth pressure mobilized at the toe of the landslide are particularly important in defining the timing and extension of shallow landslides. The model also shows that, in densely rooted hillslopes, lateral force redistribution under tension through the root-network may substantially contribute to stabilizing slopes, avoiding crack formation and large deformations. The results of the sensitivity analysis are discussed in the context of protection forest management and bioengineering techniques.

Flow dynamics in hyper-saline aquifers: hydro-geophysical monitoring and modeling

NASA Astrophysics Data System (ADS)

Haaken, Klaus; Piero Deidda, Gian; Cassiani, Giorgio; Deiana, Rita; Putti, Mario; Paniconi, Claudio; Scudeler, Carlotta; Kemna, Andreas

2017-03-01

Saline-freshwater interaction in porous media is a phenomenon of practical interest particularly for the management of water resources in arid and semi-arid environments, where precious freshwater resources are threatened by seawater intrusion and where storage of freshwater in saline aquifers can be a viable option. Saline-freshwater interactions are controlled by physico-chemical processes that need to be accurately modeled. This in turn requires monitoring of these systems, a non-trivial task for which spatially extensive, high-resolution non-invasive techniques can provide key information. In this paper we present the field monitoring and numerical modeling components of an approach aimed at understanding complex saline-freshwater systems. The approach is applied to a freshwater injection experiment carried out in a hyper-saline aquifer near Cagliari (Sardinia, Italy). The experiment was monitored using time-lapse cross-hole electrical resistivity tomography (ERT). To investigate the flow dynamics, coupled numerical flow and transport modeling of the experiment was carried out using an advanced three-dimensional (3-D) density-driven flow-transport simulator. The simulation results were used to produce synthetic ERT inversion results to be compared against real field ERT results. This exercise demonstrates that the evolution of the freshwater bulb is strongly influenced by the system's (even mild) hydraulic heterogeneities. The example also highlights how the joint use of ERT imaging and gravity-dependent flow and transport modeling give fundamental information for this type of study.

The enigmatic ultra-long run-out of seafloor density driven flows

NASA Astrophysics Data System (ADS)

Dorrell, R. M.

2017-12-01

Dilute, particulate-laden, density-driven flows - turbidity currents - are a predominant mechanism for transporting sediment from source to sink in deep marine environments. These flows sculpt channels on the seafloor and, as evidenced by a wealth of bathymetric data, can travel for >1000km, forming some of the largest sedimentary landforms on the planet. For turbidity currents to travel such large dsitances, sediment must be self-maintained in suspension, i.e., be in a state of autosuspension. It has been shown that such self-maintained sediment suspensions can only occur whilst inertial forces are greater than gravitational forces, entailing supercritical flow. This conclusion is paradoxical, as inertia dominated flows rapidly entrain fluid, thereby thickening and slowing to become subcritical. However, current theory can only truly be applied to the proximal upper slope regions of seafloor channels where incised flows are fully confined. This contrasts with the distal reaches of long run out turbidity current systems, where the flow is only partially confined through self-channelization. Here it is shown that overspill of partially confined flow has a significant effect on the hydro- and morphodynamics of turbidity current systems. A new model is derived that shows that channel overspill acts to negate the effects of ambient fluid entrainment: a dynamic balance that limits increases in flow depth and maintains supercritical flow throughout the channel. In the new model mass, momentum and energy conservation is modulated by flow overspill onto channel banks, necessarily requiring description of the vertical structure of the flow. Analysis of continuously stratified steady state flow dynamics shows that the integration of overspill and stratification is necessary to enable maintained autosuspension and thus predict the ultra-long run-out of turbidity currents.

Microstructure Evolution and Flow Stress Model of a 20Mn5 Hollow Steel Ingot during Hot Compression

PubMed Central

Liu, Min; Ma, Qing-Xian; Luo, Jian-Bin

2018-01-01

20Mn5 steel is widely used in the manufacture of heavy hydro-generator shaft due to its good performance of strength, toughness and wear resistance. However, the hot deformation and recrystallization behaviors of 20Mn5 steel compressed under high temperature were not studied. In this study, the hot compression experiments under temperatures of 850–1200 °C and strain rates of 0.01/s–1/s are conducted using Gleeble thermal and mechanical simulation machine. And the flow stress curves and microstructure after hot compression are obtained. Effects of temperature and strain rate on microstructure are analyzed. Based on the classical stress-dislocation relation and the kinetics of dynamic recrystallization, a two-stage constitutive model is developed to predict the flow stress of 20Mn5 steel. Comparisons between experimental flow stress and predicted flow stress show that the predicted flow stress values are in good agreement with the experimental flow stress values, which indicates that the proposed constitutive model is reliable and can be used for numerical simulation of hot forging of 20Mn5 hollow steel ingot. PMID:29561826

A framework for quantification of groundwater dynamics - redundancy and transferability of hydro(geo-)logical metrics

NASA Astrophysics Data System (ADS)

Heudorfer, Benedikt; Haaf, Ezra; Barthel, Roland; Stahl, Kerstin

2017-04-01

A new framework for quantification of groundwater dynamics has been proposed in a companion study (Haaf et al., 2017). In this framework, a number of conceptual aspects of dynamics, such as seasonality, regularity, flashiness or inter-annual forcing, are described, which are then linked to quantitative metrics. Hereby, a large number of possible metrics are readily available from literature, such as Pardé Coefficients, Colwell's Predictability Indices or Base Flow Index. In the present work, we focus on finding multicollinearity and in consequence redundancy among the metrics representing different patterns of dynamics found in groundwater hydrographs. This is done also to verify the categories of dynamics aspects suggested by Haaf et al., 2017. To determine the optimal set of metrics we need to balance the desired minimum number of metrics and the desired maximum descriptive property of the metrics. To do this, a substantial number of candidate metrics are applied to a diverse set of groundwater hydrographs from France, Germany and Austria within the northern alpine and peri-alpine region. By applying Principle Component Analysis (PCA) to the correlation matrix of the metrics, we determine a limited number of relevant metrics that describe the majority of variation in the dataset. The resulting reduced set of metrics comprise an optimized set that can be used to describe the aspects of dynamics that were identified within the groundwater dynamics framework. For some aspects of dynamics a single significant metric could be attributed. Other aspects have a more fuzzy quality that can only be described by an ensemble of metrics and are re-evaluated. The PCA is furthermore applied to groups of groundwater hydrographs containing regimes of similar behaviour in order to explore transferability when applying the metric-based characterization framework to groups of hydrographs from diverse groundwater systems. In conclusion, we identify an optimal number of metrics, which are readily available for usage in studies on groundwater dynamics, intended to help overcome analytical limitations that exist due to the complexity of groundwater dynamics. Haaf, E., Heudorfer, B., Stahl, K., Barthel, R., 2017. A framework for quantification of groundwater dynamics - concepts and hydro(geo-)logical metrics. EGU General Assembly 2017, Vienna, Austria.

Screening variability and change of soil moisture under wide-ranging climate conditions: Snow dynamics effects.

PubMed

Verrot, Lucile; Destouni, Georgia

2015-01-01

Soil moisture influences and is influenced by water, climate, and ecosystem conditions, affecting associated ecosystem services in the landscape. This paper couples snow storage-melting dynamics with an analytical modeling approach to screening basin-scale, long-term soil moisture variability and change in a changing climate. This coupling enables assessment of both spatial differences and temporal changes across a wide range of hydro-climatic conditions. Model application is exemplified for two major Swedish hydrological basins, Norrström and Piteälven. These are located along a steep temperature gradient and have experienced different hydro-climatic changes over the time period of study, 1950-2009. Spatially, average intra-annual variability of soil moisture differs considerably between the basins due to their temperature-related differences in snow dynamics. With regard to temporal change, the long-term average state and intra-annual variability of soil moisture have not changed much, while inter-annual variability has changed considerably in response to hydro-climatic changes experienced so far in each basin.

Combined effects of heat and mass transfer to magneto hydrodynamics oscillatory dusty fluid flow in a porous channel

NASA Astrophysics Data System (ADS)

Govindarajan, A.; Vijayalakshmi, R.; Ramamurthy, V.

2018-04-01

The main aim of this article is to study the combined effects of heat and mass transfer to radiative Magneto Hydro Dynamics (MHD) oscillatory optically thin dusty fluid in a saturated porous medium channel. Based on certain assumptions, the momentum, energy, concentration equations are obtained.The governing equations are non-dimensionalised, simplified and solved analytically. The closed analytical form solutions for velocity, temperature, concentration profiles are obtained. Numerical computations are presented graphically to show the salient features of various physical parameters. The shear stress, the rate of heat transfer and the rate of mass transfer are also presented graphically.

Climate conditions of the “El Niño” phenomenon for a hydro-eolic complementarity project in peru

NASA Astrophysics Data System (ADS)

Castillo N, Leonardo; Ortega M, Arturo; Luyo, Jaime E.

2018-05-01

Northern Peru is threatened by the consequences of a natural phenomenon called “El Niño”, mainly during the months of December to April. In the summer of 2017, this event reported strong climatic variations with intense rains, increasing the water levels of the Chira and Piura rivers, filling the Poechos reservoir, together with flooding and mudding. However, from an energetic perspective, these climatic alterations have a strong potential to increase the availability of the wind and hydro renewable energies in northern Peru. This work performs an evaluation of the hydro-eolic complementarity as part of the sustainability of energy systems. The study includes evaluation of historical records of wind velocity and water flow rates. It then evaluates correlation, analysis, and estimates the hydro and wind energy potentials generated by this phenomenon. The implications of the "El Niño" phenomenon are mostly negative. Nonetheless, it is possible to take advantage of higher wind and water flow rates with a hybrid energy system. The results obtained show a high degree of complementarity both normal and "El Niño" phenomenon condition in northern Peru.

Dynamics of natural prokaryotes, viruses, and heterotrophic nanoflagellates in alpine karstic groundwater

PubMed Central

Wilhartitz, Inés C; Kirschner, Alexander K T; Brussaard, Corina P D; Fischer, Ulrike R; Wieltschnig, Claudia; Stadler, Hermann; Farnleitner, Andreas H

2013-01-01

Abstract Seasonal dynamics of naturally occurring prokaryotes, viruses, and heterotrophic nanoflagellates in two hydro-geologically contrasting alpine karst springs were monitored over three annual cycles. To our knowledge, this study is the first to shed light on the occurrence and possible interrelationships between these three groups in karstic groundwater. Hydrological and microbiological standard indicators were recovered simultaneously in order to estimate surface influence, especially during rainfall events. Data revealed a strong dependence of the microbial communities on the prevailing hydrological situation. Prokaryotic numbers averaged 5.1 × 107 and 1.3 × 107 cells L−1, and heterotrophic nanoflagellate abundance averaged 1.1 × 104 and 3 × 103 cells L−1 in the limestone spring type (LKAS2) and the dolomitic spring type (DKAS1), respectively. Viral abundance in LKAS2 and DKAS1 averaged 9.4 × 108 and 1.1 × 108 viruses L−1. Unlike in DKAS1, the dynamic spring type LKAS2 revealed a clear difference between base flow and high discharge conditions. The virus-to-prokaryotes ratio was generally lower by a factor of 2–3, at higher average water residence times. Furthermore, the high prokaryotes-to-heterotrophic nanoflagellate ratios, namely about 4700 and 5400 for LKAS2 and DKAS1, respectively, pointed toward an uncoupling of these two groups in the planktonic fraction of alpine karstic aquifers. Seasonal dynamics of naturally occurring prokaryotes, viruses and heterotrophic nanoflagellates in two hydro-geologically contrasting alpine karst springs were monitored over three annual cycles. Data revealed a strong dependence of the microbial communities on the prevailing hydrological situation. PMID:23828838

Modeling invasive alien plant species in river systems: Interaction with native ecosystem engineers and effects on hydro-morphodynamic processes

NASA Astrophysics Data System (ADS)

van Oorschot, M.; Kleinhans, M. G.; Geerling, G. W.; Egger, G.; Leuven, R. S. E. W.; Middelkoop, H.

2017-08-01

Invasive alien plant species negatively impact native plant communities by out-competing species or changing abiotic and biotic conditions in their introduced range. River systems are especially vulnerable to biological invasions, because waterways can function as invasion corridors. Understanding interactions of invasive and native species and their combined effects on river dynamics is essential for developing cost-effective management strategies. However, numerical models for simulating long-term effects of these processes are lacking. This paper investigates how an invasive alien plant species affects native riparian vegetation and hydro-morphodynamics. A morphodynamic model has been coupled to a dynamic vegetation model that predicts establishment, growth and mortality of riparian trees. We introduced an invasive alien species with life-history traits based on Japanese Knotweed (Fallopia japonica), and investigated effects of low- and high propagule pressure on invasion speed, native vegetation and hydro-morphodynamic processes. Results show that high propagule pressure leads to a decline in native species cover due to competition and the creation of unfavorable native colonization sites. With low propagule pressure the invader facilitates native seedling survival by creating favorable hydro-morphodynamic conditions at colonization sites. With high invader abundance, water levels are raised and sediment transport is reduced during the growing season. In winter, when the above-ground invader biomass is gone, results are reversed and the floodplain is more prone to erosion. Invasion effects thus depend on seasonal above- and below ground dynamic vegetation properties and persistence of the invader, on the characteristics of native species it replaces, and the combined interactions with hydro-morphodynamics.

Destabilisation of an Arctic ice cap triggered by a hydro-thermodynamic feedback to summer-melt

NASA Astrophysics Data System (ADS)

Dunse, T.; Schellenberger, T.; Kääb, A.; Hagen, J. O.; Schuler, T. V.; Reijmer, C. H.

2014-05-01

Mass loss from glaciers and ice sheets currently accounts for two-thirds of the observed global sea-level rise and has accelerated since the 1990s, coincident with strong atmospheric warming in the Polar Regions. Here we present continuous GPS measurements and satellite synthetic aperture radar based velocity maps from the Austfonna ice cap, Svalbard, that demonstrate strong links between surface-melt and multiannual ice-flow acceleration. We identify a hydro-thermodynamic feedback that successively mobilizes stagnant ice regions, initially frozen to their bed, thereby facilitating fast basal motion over an expanding area. By autumn 2012, successive destabilization of the marine terminus escalated in a surge of the ice cap's largest drainage basin, Basin-3. The resulting iceberg discharge of 4.2 ± 1.6 Gt a-1 over the period April 2012 to May 2013 triples the calving loss from the entire ice cap. After accounting for the terminus advance, the related sea-level rise contribution of 7.2 ± 2.6 Gt a-1 matches the recent annual ice-mass loss from the entire Svalbard archipelago. Our study highlights the importance of dynamic glacier wastage and illuminates mechanisms that may trigger a sustained increase in dynamic glacier wastage or the disintegration of ice-sheets in response to climate warming, which is acknowledged but not quantified in global projections of sea-level rise.

Salix alba and Populus nigra seedlings resistance to physical hydro-sedimentary stresses: nursery experimental approach compared to in situ measurements

NASA Astrophysics Data System (ADS)

Wintenberger, Coraline; Rodrigues, Stephane; Breheret, Jean-Gabriel; Jugé, Philippe; Villar, Marc

2014-05-01

In Europe, riparian Salicaceae is declining following the loss of potential germination areas associated with river management. Nevertheless, as an exception for lowland rivers, the Loire River (France) shows in its middle reaches an efficient sexual regeneration of Populus nigra and Salix alba species on bare sediments deposited during flood events. The study focuses on the influence of flow, sediment dynamics and fluvial maintenance operations on the establishment and survival of black poplar and white willow seedlings during the first year of development in a lowland sandy-gravel river, the Middle Loire. Main questions are: what is the influence of morphological and sedimentary features on seedlings recruitment and how do they withstand the hydro-sedimentary stresses occurring during high flow periods? How fluvial management works, and induced morphology and sedimentary features, modify the sediment dynamics and subsequent establishment and maintenance of seedlings? To answer these questions, we developed an ex-situ approach which allowed, under controlled conditions, to determine the influence of the sedimentological characteristics of the substrate on the development and maintenance of seedlings with a specific focus on the root system. Three experiments were carried out for three sedimentary mixtures from the river (sand, sand-gravel and 0.2 m of sand superimposed on sand-gravel mixture) that correspond to grain size and stratigraphy conditions often observed on bars and secondary channels in the Loire. The experimental design includes 108 plots of 1 m3, with 400 seeds per plot (corresponding to the Loire density measurements) and combining seeds from two species, three sedimentary mixtures, four replicates and three experiments. Experiment 1 (control) is based on the architecture of root systems using the WinRHIZO image analysis software. Experiment 2 is relative to the evaluation of constraints leading to "uprooting" of seedlings. Experiment 3 provides data on the seedlings survival once buried during a flood event. Genetic diversity of the seed lots will be investigated via biomass and shoot / root ratio. Results reveal that willow seedlings have a higher density of roots compared to poplar. In sand mixture, poplar has a taproot system; in sand-gravel mixture, taproot is divided into several roots which leads to a branched root system. The required forces to uprooting are twice much important for sand-gravel mixture. In situ measurements detail the sediment dynamics and morphological evolution during and after floods (topography, scour/fill processes, grain size surveys, flow velocity, sediment transport rates) on a managed alluvial bar. Results associated with floods occurring after fluvial management works highlight the rapid regeneration of bedforms associated with sedimentary and hydraulics constraints. This leads to the development of new morphological and sedimentological units, suitable for seedlings recruitment. Thirty plots measurements of seedlings (densities and species) established were associated with these news physical conditions over the bar. Black poplar and white willow appeared for a wide range of grain sizes and on specific morphological units. Seedlings survival will be analyzed with regard to physical constraints determined for each plot from measurements of hydro-sedimentary dynamics and then compared to ex situ results.

Hydro-climatic simulation of Spring Creek Basin under dynamic C02 atmospheric concentration

USDA-ARS?s Scientific Manuscript database

Climate factors monitoring have indicated that global atmospheric C02 concentration rose in the past, and further rise should be expected in the future as indicated by projections. SWAT is a hydro-climatic distributed model used to assess the efficiency of agricultural and land use best management p...

Fishy Business: Response of Stream Fish Assemblages to Small Hydro-power Plant Induced Flow Alteration in the Western Ghats, Karnataka

NASA Astrophysics Data System (ADS)

Rao, S. T.; Krishnaswamy, J.; Bhalla, R. S.

2017-12-01

Alteration of natural flow regimes is considered as a major threat to freshwater fish assemblages as it disturbs the water quality and micro-habitat features of rivers. Small hydro-power (SHP), which is being promoted as a clean and green substitute for large hydro-power generation, alters the natural flow regime of head-water streams by flow diversion and regulation. The effects of altered flow regime on tropical stream fish assemblages, driven by seasonality induced perturbations to water quality and microhabitat parameters are largely understudied. My study examined the potential consequences of flow alteration by SHPs on fish assemblages in two tributaries of the west-flowing Yettinahole River which flows through the reserved forests of Sakleshpur in the Western Ghats of Karnataka. The flow in one of the tributaries followed natural flow regime while the other comprised three regimes: a near-natural flow regime above the dam, rapidly varying discharge below the dam and a dewatered regime caused by flow diversion. The study found that the altered flow regime differed from natural flow regime in terms of water quality, microhabitat heterogeneity and fish assemblage response, each indicative of the type of flow alteration. Fish assemblage in the natural flow regime was characterized by a higher catch per site, a strong association of endemic and trophic specialist species. The flow regime above the dam was found to mimic some components of the natural flow regime, both ecological and environmental. Non endemic, generalist and pool tolerant species were associated with the dewatered regime. There was a lack of strong species-regime association and an overall low catch per site for the flow regulated regime below the dam. This study highlights the consequences of altered flows on the composition of freshwater fish assemblages and portrays the potential of freshwater fish as indicators of the degree and extent of flow alteration. The study recommends the need for maintaining continuous flow data records to model ecological data with hydrological measurements. In the light of rapid SHP development, the study also suggests environmental / cumulative impact assessments of SHPs on the river basin.

Integral equation methods for vesicle electrohydrodynamics in three dimensions

NASA Astrophysics Data System (ADS)

Veerapaneni, Shravan

2016-12-01

In this paper, we develop a new boundary integral equation formulation that describes the coupled electro- and hydro-dynamics of a vesicle suspended in a viscous fluid and subjected to external flow and electric fields. The dynamics of the vesicle are characterized by a competition between the elastic, electric and viscous forces on its membrane. The classical Taylor-Melcher leaky-dielectric model is employed for the electric response of the vesicle and the Helfrich energy model combined with local inextensibility is employed for its elastic response. The coupled governing equations for the vesicle position and its transmembrane electric potential are solved using a numerical method that is spectrally accurate in space and first-order in time. The method uses a semi-implicit time-stepping scheme to overcome the numerical stiffness associated with the governing equations.

Particle Swarm Optimization for inverse modeling of solute transport in fractured gneiss aquifer

NASA Astrophysics Data System (ADS)

Abdelaziz, Ramadan; Zambrano-Bigiarini, Mauricio

2014-08-01

Particle Swarm Optimization (PSO) has received considerable attention as a global optimization technique from scientists of different disciplines around the world. In this article, we illustrate how to use PSO for inverse modeling of a coupled flow and transport groundwater model (MODFLOW2005-MT3DMS) in a fractured gneiss aquifer. In particular, the hydroPSO R package is used as optimization engine, because it has been specifically designed to calibrate environmental, hydrological and hydrogeological models. In addition, hydroPSO implements the latest Standard Particle Swarm Optimization algorithm (SPSO-2011), with an adaptive random topology and rotational invariance constituting the main advancements over previous PSO versions. A tracer test conducted in the experimental field at TU Bergakademie Freiberg (Germany) is used as case study. A double-porosity approach is used to simulate the solute transport in the fractured Gneiss aquifer. Tracer concentrations obtained with hydroPSO were in good agreement with its corresponding observations, as measured by a high value of the coefficient of determination and a low sum of squared residuals. Several graphical outputs automatically generated by hydroPSO provided useful insights to assess the quality of the calibration results. It was found that hydroPSO required a small number of model runs to reach the region of the global optimum, and it proved to be both an effective and efficient optimization technique to calibrate the movement of solute transport over time in a fractured aquifer. In addition, the parallel feature of hydroPSO allowed to reduce the total computation time used in the inverse modeling process up to an eighth of the total time required without using that feature. This work provides a first attempt to demonstrate the capability and versatility of hydroPSO to work as an optimizer of a coupled flow and transport model for contaminant migration.

Robust Control Analysis of Hydraulic Turbine Speed

NASA Astrophysics Data System (ADS)

Jekan, P.; Subramani, C.

2018-04-01

An effective control strategy for the hydro-turbine governor in time scenario is adjective for this paper. Considering the complex dynamic characteristic and the uncertainty of the hydro-turbine governor model and taking the static and dynamic performance of the governing system as the ultimate goal, the designed logic combined the classical PID control theory with artificial intelligence used to obtain the desired output. The used controller will be a variable control techniques, therefore, its parameters can be adaptively adjusted according to the information about the control error signal.

Hot Deformation Behavior and a Two-Stage Constitutive Model of 20Mn5 Solid Steel Ingot during Hot Compression

PubMed Central

Liu, Min; Ma, Qing-Xian; Luo, Jian-Bin

2018-01-01

20Mn5 steel is widely used in the manufacture of heavy hydro-generator shaft forging due to its strength, toughness, and wear resistance. However, the hot deformation and recrystallization behaviors of 20Mn5 steel compressed under a high temperature were not studied. For this article, hot compression experiments under temperatures of 850–1200 °C and strain rates of 0.01 s−1–1 s−1 were conducted using a Gleeble-1500D thermo-mechanical simulator. Flow stress-strain curves and microstructure after hot compression were obtained. Effects of temperature and strain rate on microstructure are analyzed. Based on the classical stress-dislocation relationship and the kinetics of dynamic recrystallization, a two-stage constitutive model is developed to predict the flow stress of 20Mn5 steel. Comparisons between experimental flow stress and predicted flow stress show that the predicted flow stress values are in good agreement with the experimental flow stress values, which indicates that the proposed constitutive model is reliable and can be used for numerical simulation of hot forging of 20Mn5 solid steel ingot. PMID:29547570

MHD thrust vectoring of a rocket engine

NASA Astrophysics Data System (ADS)

Labaune, Julien; Packan, Denis; Tholin, Fabien; Chemartin, Laurent; Stillace, Thierry; Masson, Frederic

2016-09-01

In this work, the possibility to use MagnetoHydroDynamics (MHD) to vectorize the thrust of a solid propellant rocket engine exhaust is investigated. Using a magnetic field for vectoring offers a mass gain and a reusability advantage compared to standard gimbaled, elastomer-joint systems. Analytical and numerical models were used to evaluate the flow deviation with a 1 Tesla magnetic field inside the nozzle. The fluid flow in the resistive MHD approximation is calculated using the KRONOS code from ONERA, coupling the hypersonic CFD platform CEDRE and the electrical code SATURNE from EDF. A critical parameter of these simulations is the electrical conductivity, which was evaluated using a set of equilibrium calculations with 25 species. Two models were used: local thermodynamic equilibrium and frozen flow. In both cases, chlorine captures a large fraction of free electrons, limiting the electrical conductivity to a value inadequate for thrust vectoring applications. However, when using chlorine-free propergols with 1% in mass of alkali, an MHD thrust vectoring of several degrees was obtained.

An Implicit Solver on A Parallel Block-Structured Adaptive Mesh Grid for FLASH

NASA Astrophysics Data System (ADS)

Lee, D.; Gopal, S.; Mohapatra, P.

2012-07-01

We introduce a fully implicit solver for FLASH based on a Jacobian-Free Newton-Krylov (JFNK) approach with an appropriate preconditioner. The main goal of developing this JFNK-type implicit solver is to provide efficient high-order numerical algorithms and methodology for simulating stiff systems of differential equations on large-scale parallel computer architectures. A large number of natural problems in nonlinear physics involve a wide range of spatial and time scales of interest. A system that encompasses such a wide magnitude of scales is described as "stiff." A stiff system can arise in many different fields of physics, including fluid dynamics/aerodynamics, laboratory/space plasma physics, low Mach number flows, reactive flows, radiation hydrodynamics, and geophysical flows. One of the big challenges in solving such a stiff system using current-day computational resources lies in resolving time and length scales varying by several orders of magnitude. We introduce FLASH's preliminary implementation of a time-accurate JFNK-based implicit solver in the framework of FLASH's unsplit hydro solver.

Contribution of lateral terrestrial water flows to the regional hydrological cycle: A joint soil-atmospheric moisture tagging procedure with WRF-Hydro

NASA Astrophysics Data System (ADS)

Arnault, Joel; Wei, Jianhui; Zhang, Zhenyu; Wagner, Sven; Kunstmann, Harald

2017-04-01

Water resources management requires an accurate knowledge of the behavior of the regional hydrological cycle components, including precipitation, evapotranspiration, river discharge and soil water storage. Atmospheric models such as the Weather Research and Forecasting (WRF) model provide a tool to evaluate these components. The main drawback of these atmospheric models, however, is that the terrestrial segment of the hydrological cycle is reduced to vertical infiltration, and that lateral terrestrial water flows are neglected. Recent model developments have focused on coupled atmospheric-hydrological modeling systems, such as WRF-hydro, in order to take into account subsurface, overland and river flow. The aim of this study is to investigate the contribution of lateral terrestrial water flows to the regional hydrological cycle, with the help of a joint soil-atmospheric moisture tagging procedure. This procedure is the extended version of an existing atmospheric moisture tagging method developed in WRF and WRF-Hydro (Arnault et al. 2017). It is used to quantify the partitioning of precipitation into water stored in the soil, runoff, evapotranspiration, and potentially subsequent precipitation through regional recycling. An application to a high precipitation event on 23 June 2009 in the upper Danube river basin, Germany and Austria, is presented. Precipitating water during this day is tagged for the period 2009-2011. Its contribution to runoff and evapotranspiration decreases with time, but is still not negligible in the summer 2011. At the end of the study period, less than 5 % of the precipitating water on 23 June 2009 remains in the soil. The additionally resolved lateral terrestrial water flows in WRF-Hydro modify the partitioning between surface and underground runoff, in association with a slight increase of evapotranspiration and recycled precipitation. Reference: Arnault, J., R. Knoche, J. Wei, and H. Kunstmann (2016), Evaporation tagging and atmospheric water budget analysis with WRF: A regional precipitation recycling study for West Africa, Water Resour. Res., 52, 1544-1567, doi:10.1002/2015WR017704.

Role of surface and subsurface lateral water flows on summer precipitation in a complex terrain region: A WRF-Hydro case-study for Southern Germany

NASA Astrophysics Data System (ADS)

Rummler, Thomas; Arnault, Joel; Gochis, David; Kunstmann, Harald

2017-04-01

Recent developments in hydrometeorological modeling aim towards more sophisticated treatment of terrestrial hydrologic processes. The standard version of the Weather Research and Forecasting (WRF) model describes terrestrial water transport as a purely vertical process. The hydrologically enhanced version of WRF, namely WRF-Hydro, does account for lateral terrestrial water flows, which allows for a more comprehensive process description of the interdependencies between water- and energy fluxes at the land-atmosphere interface. In this study, WRF and WRF-Hydro are applied to the Bavarian Alpine region in southern Germany, a complex terrain landscape in a relatively humid, mid-latitude climate. Simulation results are validated with gridded and station observation of precipitation, temperature and river discharge. Differences between WRF and WRF-Hydro results are investigated with a joint atmospheric-terrestrial water budget analysis. Changes in the partitioning in (near-) surface runoff and percolation are prominent. However, values for evapotranspiration ET feature only marginal variations, suggesting that soil moisture content is not a limiting factor of ET in this specific region. Simulated precipitation fields during isolated summertime events still show appreciable differences, while differences in large-scale, multi-day rainy periods are less substantial. These differences are mainly related to differences in the moisture in- and outflow terms of the atmospheric water budget induced by the surface and sub-surface lateral redistribution of soil moisture in WRF-Hydro.

Wind-Driven Ecological Flow Regimes Downstream from Hydropower Dams

NASA Astrophysics Data System (ADS)

Kern, J.; Characklis, G. W.

2012-12-01

Conventional hydropower can be turned on and off quicker and less expensively than thermal generation (coal, nuclear, or natural gas). These advantages enable hydropower utilities to respond to rapid fluctuations in energy supply and demand. More recently, a growing renewable energy sector has underlined the need for flexible generation capacity that can complement intermittent renewable resources such as wind power. While wind power entails lower variable costs than other types of generation, incorporating it into electric power systems can be problematic. Due to variable and unpredictable wind speeds, wind power is difficult to schedule and must be used when available. As a result, integrating large amounts of wind power into the grid may result in atypical, swiftly changing demand patterns for other forms of generation, placing a premium on sources that can be rapidly ramped up and down. Moreover, uncertainty in wind power forecasts will stipulate increased levels of 'reserve' generation capacity that can respond quickly if real-time wind supply is less than expected. These changes could create new hourly price dynamics for energy and reserves, altering the short-term financial signals that hydroelectric dam operators use to schedule water releases. Traditionally, hourly stream flow patterns below hydropower dams have corresponded in a very predictable manner to electricity demand, whose primary factors are weather (hourly temperature) and economic activity (workday hours). Wind power integration has the potential to yield more variable, less predictable flows at hydro dams, flows that at times could resemble reciprocal wind patterns. An existing body of research explores the impacts of standard, demand-following hydroelectric dams on downstream ecological flows; but weighing the benefits of increased reliance on wind power against further impacts to ecological flows may be a novel challenge for the environmental community. As a preliminary step in meeting this challenge, the following study was designed to investigate the potential for wind power integration to alter riparian flow regimes below hydroelectric dams. A hydrological model of a three-dam cascade in the Roanoke River basin (Virginia, USA) is interfaced with a simulated electricity market (i.e. a unit commitment problem) representing the Dominion Zone of PJM Interconnection. Incorporating forecasts of electricity demand, hydro capacity and wind availability, a mixed-integer optimization program minimizes the system cost of meeting hourly demand and reserve requirements by means of a diverse generation portfolio (e.g. nuclear, fossil, hydro, and biomass). A secondary 'balancing' energy market is executed if real-time wind generation is less than the day-ahead forecast, calling upon reserved generation resources to meet the supply shortfall. Hydropower release schedules are determined across a range of wind development scenarios (varying wind's fraction of total installed generating capacity, as well as its geographical source region). Flow regimes for each wind development scenario are compared against both historical and simulated flows under current operations (negligible wind power), as well as simulated natural flows (dam removal), in terms of ecologically relevant flow metrics. Results quantify the ability of wind power development to alter within-week stream flows downstream from hydropower dams.

Drought Conditions Maximize the Impact of High-Frequency Flow Variations on Thermal Regimes and Biogeochemical Function in the Hyporheic Zone.

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

Anthropogenic activities, such as dam operations, often induce larger and more frequent stage fluctuations than those occurring in natural rivers. However, the long-term impact of such flow variations on thermal and biogeochemical dynamics of the associated hyporheic zone (HZ) is poorly understood. A heterogeneous, two-dimensional thermo-hydro-biogeochemical model revealed an important interaction between high-frequency flow variations and watershed-scale hydrology. High-frequency stage fluctuations had their strongest thermal and biogeochemical impacts when the mean river stage was low during fall and winter. An abnormally thin snowpack in 2015, however, created a low river stage during summer and early fall, whereby high frequency stagemore » fluctuations caused the HZ to be warmer than usual. This study provided the scientific basis to assess the potential ecological consequences of the high-frequency flow variations in a regulated river, as well as guidance on how to maximize the potential benefits—or minimize the drawbacks—of river regulation to river ecosystems.« less

Temporal variations of NDVI and correlations between NDVI and hydro-climatological variables at Lake Baiyangdian, China.

PubMed

Wang, Fei; Wang, Xuan; Zhao, Ying; Yang, Zhifeng

2014-09-01

In this paper, correlations between vegetation dynamics (represented by the normalized difference vegetation index (NDVI)) and hydro-climatological factors were systematically studied in Lake Baiyangdian during the period from April 1998 to July 2008. Six hydro-climatological variables including lake volume, water level, air temperature, precipitation, evaporation, and sunshine duration were used, as well as extracted NDVI series data representing vegetation dynamics. Mann-Kendall tests were used to detect trends in NDVI and hydro-climatological variation, and a Bayesian information criterion method was used to detect their abrupt changes. A redundancy analysis (RDA) was used to determine the major hydro-climatological factors contributing to NDVI variation at monthly, seasonal, and yearly scales. The results were as follows: (1) the trend analysis revealed that only sunshine duration significantly increased over the study period, with an inter-annual increase of 3.6 h/year (p < 0.01), whereas inter-annual NDVI trends were negligible; (2) the abrupt change detection showed that a major hydro-climatological change occurred in 2004, when abrupt changes occurred in lake volume, water level, and sunlight duration; and (3) the RDA showed that evaporation and temperature were highly correlated with monthly changes in NDVI. At larger time scales, however, water level and lake volume gradually became more important than evaporation and precipitation in terms of their influence on NDVI. These results suggest that water availability is the most important factor in vegetation restoration. In this paper, we recommend a practical strategy for lake ecosystem restoration that takes into account changes in NDVI.

Mechanism of emergence of intense vibrations of turbines on the Sayano-Shushensk hydro power plant

NASA Astrophysics Data System (ADS)

Kurzin, V. B.; Seleznev, V. S.

2010-07-01

It is demonstrated that the level of vibrations of turbines on the Sayano-Shushensk hydro power plant is enhanced by the capability of a compressible fluid to perform its own hydroacoustic oscillations (which can be unstable) in the turbine duct. Based on the previously obtained results of solving the problem of natural hydroacoustic oscillations in the turbine duct and some ideas about turbine interaction with an unsteady compressible fluid flow, results of full-scale studies of turbine vibrations and seismic monitoring of the dam of the Sayano-Shushensk hydro power plant before and during the accident are analyzed.

A new methodology for hydro-abrasive erosion tests simulating penstock erosive flow

NASA Astrophysics Data System (ADS)

Aumelas, V.; Maj, G.; Le Calvé, P.; Smith, M.; Gambiez, B.; Mourrat, X.

2016-11-01

Hydro-abrasive resistance is an important property requirement for hydroelectric power plant penstock coating systems used by EDF. The selection of durable coating systems requires an experimental characterization of coating performance. This can be achieved by performing accelerated and representative laboratory tests. In case of severe erosion induced by a penstock flow, there is no suitable method or standard representative of real erosive flow conditions. The presented study aims at developing a new methodology and an associated laboratory experimental device. The objective of the laboratory apparatus is to subject coated test specimens to wear conditions similar to the ones generated at the penstock lower generatrix in actual flow conditions. Thirteen preselected coating solutions were first been tested during a 45 hours erosion test. A ranking of the thirteen coating solutions was then determined after characterisation. To complete this first evaluation and to determine the wear kinetic of the four best coating solutions, additional erosion tests were conducted with a longer duration of 216 hours. A comparison of this new method with standardized tests and with real service operating flow conditions is also discussed. To complete the final ranking based on hydro-abrasive erosion tests, some trial tests were carried out on penstock samples to check the application method of selected coating systems. The paper gives some perspectives related to erosion test methodologies for materials and coating solutions for hydraulic applications. The developed test method can also be applied in other fields.

Restoring coastal wetlands that were ditched for mosquito control: a preliminary assessment of hydro-leveling as a restoration technique

USGS Publications Warehouse

Smith, Thomas J.; Tiling, Ginger; Leasure, Pamela S.

2007-01-01

The wetlands surrounding Tampa Bay, Florida were extensively ditched for mosquito control in the 1950s. Spoil from ditch construction was placed adjacent to the wetlands ditches creating mound-like features (spoil-mounds). These mounds represent a loss of 14% of the wetland area in Tampa Bay. Spoil mounds interfere with tidal flow and are locations for non-native plants to colonize (e.g., Schinus terebinthifolius). Removal of the spoil mounds to eliminate exotic plants, restore native vegetation, and re-establish natural hydrology is a restoration priority for environmental managers. Hydro-leveling, a new technique, was tested in a mangrove forest restoration project in 2004. Hydro-leveling uses a high pressure stream of water to wash sediment from the spoil mound into the adjacent wetland and ditch. To assess the effectiveness of this technique, we conducted vegetation surveys in areas that were hydro-leveled and in non-hydro-leveled areas 3 years post-project. Adult Schinus were reduced but not eliminated from hydro-leveled mounds. Schinus seedlings however were absent from hydro-leveled sites. Colonization by native species was sparse. Mangrove seedlings were essentially absent (≈2 m−2) from the centers of hydro-leveled mounds and were in low density on their edges (17 m−2) in comparison to surrounding mangrove forests (105 m−2). Hydro-leveling resulted in mortality of mangroves adjacent to the mounds being leveled. This was probably caused by burial of pneumatophores during the hydro-leveling process. For hydro-leveling to be a useful and successful restoration technique several requirements must be met. Spoil mounds must be lowered to the level of the surrounding wetlands. Spoil must be distributed further into the adjacent wetland to prevent burial of nearby native vegetation. Finally, native species may need to be planted on hydro-leveled areas to speed up the re-vegetation process.

A new and integrated hydro-economic accounting and analytical framework for water resources: a case study for North China.

PubMed

Guan, Dabo; Hubacek, Klaus

2008-09-01

Water is a critical issue in China for a variety of reasons. China is poor of water resources with 2,300 m(3) of per capita availability, which is less than 13 of the world average. This is exacerbated by regional differences; e.g. North China's water availability is only about 271 m(3) of per capita value, which is only 125 of the world's average. Furthermore, pollution contributes to water scarcity and is a major source for diseases, particularly for the poor. The Ministry of Hydrology [1997. China's Regional Water Bullets. Water Resource and Hydro-power Publishing House, Beijing, China] reports that about 65-80% of rivers in North China no longer support any economic activities. Previous studies have emphasized the amount of water withdrawn but rarely take water quality into consideration. The quality of the return flows usually changes; the water quality being lower than the water flows that entered the production process initially. It is especially important to measure the impacts of wastewater to the hydro-ecosystem. Thus, water consumption should not only account for the amount of water inputs but also the amount of water contaminated in the hydro-ecosystem by the discharged wastewater. In this paper we present a new accounting and analytical approach based on economic input-output modelling combined with a mass balanced hydrological model that links interactions in the economic system with interactions in the hydrological system. We thus follow the tradition of integrated economic-ecologic input-output modelling. Our hydro-economic accounting framework and analysis tool allows tracking water consumption on the input side, water pollution leaving the economic system and water flows passing through the hydrological system thus enabling us to deal with water resources of different qualities. Following this method, the results illustrate that North China requires 96% of its annual available water, including both water inputs for the economy and contaminated water that is ineligible for any uses.

Numerical investigation and performance characteristic mapping of an Archimedean screw hydroturbine

NASA Astrophysics Data System (ADS)

Schleicher, W. Chris

Computational Fluid Dynamics (CFD) is a crucial tool in the design and analysis of hydraulic machinery, especially in the design of a micro hydro turbine. The micro hydro turbine in question is for a low head (less than 60 meters), low volumetric flow rate (0.005 m3/s to 0.5 m 3/s) application with rotation rates varying from 200 RPM to 1500 RPM. The design of the runner geometry is discussed, specifically a non-uniform Archimedean Spiral with an outer diameter of 6 inches and length of 19.5 inches. The transient simulation method, making use of a frame of reference change and a rotating mesh between time-steps, is explained as well as the corresponding boundary conditions. Both simulation methods are compared and are determined to produce similar results. The rotating frame of reference method was determined to be the most suitable method for the mapping of performance characteristic such as required head, torque, power, and efficiency. Results of simulations for a non-uniform Archimedean Spiral are then presented. First, a spectral and temporal convergence study is conducted to make sure that the results are independent of time-step and mesh selection. Performance characteristics of a non-uniform pitched blade turbine are determined for a wide range of volumetric flow rates and rotation rates. The maximum efficiency of the turbine is calculated around 72% for the design of the turbine blade considered in the present study.

Hydro-climatic control of stream dissolved organic carbon in headwater catchment

NASA Astrophysics Data System (ADS)

Humbert, Guillaume; Jaffrezic, Anne; Fovet, Ophélie; Gruau, Gérard; Durand, Patrick

2014-05-01

Dissolved organic matter (DOM) is a key form of the organic matter linking together the water and the carbon cycles and interconnecting the biosphere (terrestrial and marine) and the soil. At the landscape scale, land use and hydrology are the main factors controlling the amount of DOM transferred from soils to the stream. In an intensively cultivated catchment, a recent work using isotopic composition of DOM as a marker has identified two different sources of DOM. The uppermost soil horizons of the riparian wetland appear as a quasi-infinite source while the topsoil of the hillslope forms a limited one mobilized by water-table rise and exported to the stream across the upland-riparian wetland-stream continuum. In addition to the exportation of DOM via water fluxes, climatic factors like temperature and precipitation regulate the DOM production by influencing microbial activity and soil organic matter degradation. The small headwater catchment (5 km²) of Kervidy-Naizin located in Brittany is part of the Environment Research Observatory (ORE) AgrHys. Weather and the hydro-chemistry of the stream, and the groundwater levels are daily recorded since 1993, 2000 and 2001 respectively. Over 13 contrasted hydrological years, the annual flow weighted mean concentration of dissolved organic carbon (DOC) is 5.6 mg.L-1 (sd = 0.7) for annual precipitation varying from 488mm to 1327mm and annual mean temperatures of 11°C (sd = 0.6). Based on this considerable dataset and this annual variability, we tried to understand how the hydro-climatic conditions determinate the stream DOC concentrations along the year. From the fluctuations of water table depth, each hydrologic year has been divided into three main period: i) progressive rewetting of the riparian wetland soils, ii) rising and holding high of the water table in the hillslope, iii) drawdown of the water-table, with less and less topsoil connected to the stream. Within each period base flow and storm flow data were first pooled then treated separately and the influence of preceding periods was tested. This hydrological division of time allowed us to identify climate effect on the topsoil DOM stores of the wetland and hillslope separately. Meteorological and hydro-pedological variables, like soil temperatures or duration of the water saturation in the organo-mineral horizons have been used to interpret the DOC concentrations and fluxes at the outlet within each period. The three hydrological periods contribute respectively to less than 17%, more than 63%, and less than 26% of the annual DOM exportation with flow weighted mean concentration of DOC of 9.5, 6.1, and 3.8 mg.L-1. Considering several DOM sources with different properties of depletion under climatic control, the main output of the work is to provide a modified conceptual model of the DOC dynamics.

Balancing power production and instream flow regime for small scale hydropower

NASA Astrophysics Data System (ADS)

Perona, P.; Gorla, L.; Characklis, G. W.

2013-12-01

Flow diversion from river and torrent main stems is a common practice to feed water uses such run-of-river and mini-hydropower, irrigation, etc. Considering the worldwide increasing water demand, it becomes mandatory to take the importance of riparian ecosystems and related biodiversity into account before starting such practices. In this paper, we use a simple hydro-economic model (Perona et al., 2013, Gorla and Perona, 2013) to show that redistribution policies at diversion nodes allow for a clear bio-economic interpretation of residual flows. This model uses the Principle of Equal Marginal Utility (PEMU) as optimal water allocation rule for generating natural-like flow releases while maximizing the aggregated economic benefits of both the riparian environment and the traditional use (e.g., hydropower). We show that both static and dynamic release polices such Minimal Flow, and Proportional/Non-proportional Repartitions, respectively, can all be represented in terms of PEMU, making explicit the value of the ecosystem health underlying each policy. The related ecological and economical performances are evaluated by means of hydrological/ecological indicators. We recommend taking this method into account as a helpful tool guiding political, economical and ecological decisions when replacing the inadequate concept of Minimum Flow Requirement (MFR) with dynamic ones. References Perona, P., D. Dürrenmatt and G. Characklis (2013) Obtaining natural-like flow releases in diverted river reaches from simple riparian benefit economic models. Journal of Environmental Management, 118: 161-169, http://dx.doi.org/10.1016/j.jenvman.2013.01.010 Gorla, L. and P. Perona (2013) On quantifying ecologically sustainable flow releases in a diverted river reach. Journal of Hydrology, 489: 98- 107, http://dx.doi.org/10.1016/j.jhydrol.2013.02.043

Coupled Long-Term Simulation of Reach-Scale Water and Heat Fluxes Across the River-Groundwater Interface for Retrieving Hyporheic Residence Times and Temperature Dynamics

NASA Astrophysics Data System (ADS)

Munz, Matthias; Oswald, Sascha E.; Schmidt, Christian

2017-11-01

Flow patterns in conjunction with seasonal and diurnal temperature variations control ecological and biogeochemical conditions in hyporheic sediments. In particular, hyporheic temperatures have a great impact on many temperature-sensitive microbial processes. In this study, we used 3-D coupled water flow and heat transport simulations applying the HydroGeoSphere code in combination with high-resolution observations of hydraulic heads and temperatures to quantify reach-scale water and heat flux across the river-groundwater interface and hyporheic temperature dynamics of a lowland gravel bed river. The model was calibrated in order to constrain estimates of the most sensitive model parameters. The magnitude and variations of the simulated temperatures matched the observed ones, with an average mean absolute error of 0.7°C and an average Nash Sutcliffe efficiency of 0.87. Our results indicate that nonsubmerged streambed structures such as gravel bars cause substantial thermal heterogeneity within the saturated sediment at the reach scale. Individual hyporheic flow path temperatures strongly depend on the flow path residence time, flow path depth, river, and groundwater temperature. Variations in individual hyporheic flow path temperatures were up to 7.9°C, significantly higher than the daily average (2.8°C), but still lower than the average seasonal hyporheic temperature difference (19.2°C). The distribution between flow path temperatures and residence times follows a power law relationship with exponent of about 0.37. Based on this empirical relation, we further estimated the influence of hyporheic flow path residence time and temperature on oxygen consumption which was found to partly increase by up to 29% in simulations.

3D flow focusing for microfluidic flow cytometry with ultrasonics

NASA Astrophysics Data System (ADS)

Gnyawali, Vaskar; Strohm, Eric M.; Daghighi, Yasaman; van de Vondervoort, Mia; Kolios, Michael C.; Tsai, Scott S. H.

2015-11-01

We are developing a flow cytometer that detects unique acoustic signature waves generated from single cells due to interactions between the cells and ultrasound waves. The generated acoustic waves depend on the size and biomechanical properties of the cells and are sufficient for identifying cells in the medium. A microfluidic system capable of focusing cells through a 10 x 10 μm ultrasound beam cross section was developed to facilitate acoustic measurements of single cells. The cells are streamlined in a hydro-dynamically 3D focused flow in a 300 x 300 μm channel made using PDMS. 3D focusing is realized by lateral sheath flows and an inlet needle (inner diameter 100 μm). The accuracy of the 3D flow focusing is measured using a dye and detecting its localization using confocal microscopy. Each flowing cell would be probed by an ultrasound pulse, which has a center frequency of 375 MHz and bandwidth of 250 MHz. The same probe would also be used for recording the scattered waves from the cells, which would be processed to distinguish the physical and biomechanical characteristics of the cells, eventually identifying them. This technique has potential applications in detecting circulating tumor cells, blood cells and blood-related diseases.

76 FR 70434 - Shelbyville Hydro LLC; Notice of Application Tendered for Filing With the Commission and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-14

... agencies: Federal, state, local, and tribal agencies with jurisdiction and/or special expertise with... as flow regimens and pool levels are set forth by the Corps. The project would generate power using flows between 130 cfs (cubic feet per second) to 1,500 cfs. When flows are below 130 cfs, all flows...

77 FR 56826 - Red River Hydro LLC; Notice of Application Accepted for Filing, Soliciting Motions To Intervene...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-14

... generate power using flows between 2,700 and 49,800 cubic feet per second (cfs). If flows are less than 2,700 cfs, all flow would go through the Corps' gates, and the project would then be offline. When flows are greater than 49,800 cfs, the excess flow would be directed through the Corps' gates. m. A copy of...

Hydro-economic modelling in mining catchments

NASA Astrophysics Data System (ADS)

Ossa Moreno, J. S.; McIntyre, N.; Rivera, D.; Smart, J. C. R.

2017-12-01

Hydro-economic models are gaining momentum because of their capacity to model both the physical processes related to water supply, and socio-economic factors determining water demand. This is particularly valuable in the midst of the large uncertainty upon future climate conditions and social trends. Agriculture, urban uses and environmental flows have received a lot of attention from researchers, as these tend to be the main consumers of water in most catchments. Mine water demand, although very important in several small and medium-sized catchments worldwide, has received less attention and only few models have attempted to reproduce its dynamics with other users. This paper describes an on-going project that addresses this gap, by developing a hydro-economic model in the upper Aconcagua River in Chile. This is a mountain catchment with large scale mining and hydro-power users at high altitudes, and irrigation areas in a downstream valley. Relevant obstacles to the model included the lack of input climate data, which is a common feature in several mining areas, the complex hydrological processes in the area and the difficulty of quantifying the value of water used by mines. A semi-distributed model developed within the Water Evaluation and Planning System (WEAP), was calibrated to reproduce water supply, and this was complemented with an analysis of the value of water for mining based on two methods; water markets and an analysis of its production processes. Agriculture and other users were included through methods commonly used in similar models. The outputs help understanding the value of water in the catchment, and its sensitivity to changes in climate variables, market prices, environmental regulations and changes in the production of minerals, crops and energy. The results of the project highlight the importance of merging hydrology and socio-economic calculations in mining regions, in order to better understand trade-offs and cost of opportunity of using water for an economic activity with high revenues, averse to water risks and with potentially large catchment impacts.

Evaluation of snow and frozen soil parameterization in a cryosphere land surface modeling framework in the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Zhou, J.

2017-12-01

Snow and frozen soil are important components in the Tibetan Plateau, and influence the water cycle and energy balances through snowpack accumulation and melt and soil freeze-thaw. In this study, a new cryosphere land surface model (LSM) with coupled snow and frozen soil parameterization was developed based on a hydrologically improved LSM (HydroSiB2). First, an energy-balance-based three-layer snow model was incorporated into HydroSiB2 (hereafter HydroSiB2-S) to provide an improved description of the internal processes of the snow pack. Second, a universal and simplified soil model was coupled with HydroSiB2-S to depict soil water freezing and thawing (hereafter HydroSiB2-SF). In order to avoid the instability caused by the uncertainty in estimating water phase changes, enthalpy was adopted as a prognostic variable instead of snow/soil temperature in the energy balance equation of the snow/frozen soil module. The newly developed models were then carefully evaluated at two typical sites of the Tibetan Plateau (TP) (one snow covered and the other snow free, both with underlying frozen soil). At the snow-covered site in northeastern TP (DY), HydroSiB2-SF demonstrated significant improvements over HydroSiB2-F (same as HydroSiB2-SF but using the original single-layer snow module of HydroSiB2), showing the importance of snow internal processes in three-layer snow parameterization. At the snow-free site in southwestern TP (Ngari), HydroSiB2-SF reasonably simulated soil water phase changes while HydroSiB2-S did not, indicating the crucial role of frozen soil parameterization in depicting the soil thermal and water dynamics. Finally, HydroSiB2-SF proved to be capable of simulating upward moisture fluxes toward the freezing front from the underlying soil layers in winter.

Development of a land surface model with coupled snow and frozen soil physics

NASA Astrophysics Data System (ADS)

Wang, Lei; Zhou, Jing; Qi, Jia; Sun, Litao; Yang, Kun; Tian, Lide; Lin, Yanluan; Liu, Wenbin; Shrestha, Maheswor; Xue, Yongkang; Koike, Toshio; Ma, Yaoming; Li, Xiuping; Chen, Yingying; Chen, Deliang; Piao, Shilong; Lu, Hui

2017-06-01

Snow and frozen soil are important factors that influence terrestrial water and energy balances through snowpack accumulation and melt and soil freeze-thaw. In this study, a new land surface model (LSM) with coupled snow and frozen soil physics was developed based on a hydrologically improved LSM (HydroSiB2). First, an energy-balance-based three-layer snow model was incorporated into HydroSiB2 (hereafter HydroSiB2-S) to provide an improved description of the internal processes of the snow pack. Second, a universal and simplified soil model was coupled with HydroSiB2-S to depict soil water freezing and thawing (hereafter HydroSiB2-SF). In order to avoid the instability caused by the uncertainty in estimating water phase changes, enthalpy was adopted as a prognostic variable instead of snow/soil temperature in the energy balance equation of the snow/frozen soil module. The newly developed models were then carefully evaluated at two typical sites of the Tibetan Plateau (TP) (one snow covered and the other snow free, both with underlying frozen soil). At the snow-covered site in northeastern TP (DY), HydroSiB2-SF demonstrated significant improvements over HydroSiB2-F (same as HydroSiB2-SF but using the original single-layer snow module of HydroSiB2), showing the importance of snow internal processes in three-layer snow parameterization. At the snow-free site in southwestern TP (Ngari), HydroSiB2-SF reasonably simulated soil water phase changes while HydroSiB2-S did not, indicating the crucial role of frozen soil parameterization in depicting the soil thermal and water dynamics. Finally, HydroSiB2-SF proved to be capable of simulating upward moisture fluxes toward the freezing front from the underlying soil layers in winter.

Toward hydro-social modeling: Merging human variables and the social sciences with climate-glacier runoff models (Santa River, Peru)

NASA Astrophysics Data System (ADS)

Carey, Mark; Baraer, Michel; Mark, Bryan G.; French, Adam; Bury, Jeffrey; Young, Kenneth R.; McKenzie, Jeffrey M.

2014-10-01

Glacier shrinkage caused by climate change is likely to trigger diminished and less consistent stream flow in glacier-fed watersheds worldwide. To understand, model, and adapt to these climate-glacier-water changes, it is vital to integrate the analysis of both water availability (the domain of hydrologists) and water use (the focus for social scientists). Drawn from a case study of the Santa River watershed below Peru’s glaciated Cordillera Blanca mountain range, this paper provides a holistic hydro-social framework that identifies five major human variables critical to hydrological modeling because these forces have profoundly influenced water use over the last 60 years: (1) political agendas and economic development; (2) governance: laws and institutions; (3) technology and engineering; (4) land and resource use; and (5) societal responses. Notable shifts in Santa River water use-including major expansions in hydroelectricity generation, large-scale irrigation projects, and other land and resource-use practices-did not necessarily stem from changing glacier runoff or hydrologic shifts, but rather from these human variables. Ultimately, then, water usage is not predictable based on water availability alone. Glacier runoff conforms to certain expected trends predicted by models of progressively reduced glacier storage. However, societal forces establish the legal, economic, political, cultural, and social drivers that actually shape water usage patterns via human modification of watershed dynamics. This hydro-social framework has widespread implications for hydrological modeling in glaciated watersheds from the Andes and Alps to the Himalaya and Tien Shan, as well as for the development of climate change adaptation plans.

Models of Plumes: Their Flow, Their Geometric Spreading, and Their Mixing with Interplume Flow

NASA Technical Reports Server (NTRS)

Suess, Steven T.

1998-01-01

There are two types of plume flow models: (1) 1D models using ad hoc spreading functions, f(r); (2) MagnetoHydroDynamics (MHD) models. 1D models can be multifluid, time dependent, and incorporate very general descriptions of the energetics. They confirm empirical results that plume flow is slow relative to requirements for high speed wind. But, no published 1 D model incorporates the rapid local spreading at the base (fl(r)) which has an important effect on mass flux. The one published MHD model is isothermal, but confirms that if b=8*pi*p/absolute value(B)2<

Progress on Numerical Modeling of the Dispersion of Ceramic Nanoparticles During Ultrasonic Processing and Solidification of Al-Based Nanocomposites

NASA Astrophysics Data System (ADS)

Zhang, Daojie; Nastac, Laurentiu

2016-12-01

In present study, 6061- and A356-based nano-composites are fabricated by using the ultrasonic stirring technology (UST) in a coreless induction furnace. SiC nanoparticles are used as the reinforcement. Nanoparticles are added into the molten metal and then dispersed by ultrasonic cavitation and acoustic streaming assisted by electromagnetic stirring. The applied UST parameters in the current experiments are used to validate a recently developed magneto-hydro-dynamics (MHD) model, which is capable of modeling the cavitation and nanoparticle dispersion during UST processing. The MHD model accounts for turbulent fluid flow, heat transfer and solidification, and electromagnetic field, as well as the complex interaction between the nanoparticles and both the molten and solidified alloys by using ANSYS Maxwell and ANSYS Fluent. Molecular dynamics (MD) simulations are conducted to analyze the complex interactions between the nanoparticle and the liquid/solid interface. The current modeling results demonstrate that a strong flow can disperse the nanoparticles relatively well during molten metal and solidification processes. MD simulation results prove that ultrafine particles (10 nm) will be engulfed by the solidification front instead of being pushed, which is beneficial for nano-dispersion.

Hydro-meteorological risk reduction through land restoration in Rangárvellir, Iceland - an overview of the HydroResilience project

NASA Astrophysics Data System (ADS)

Finger, David C.; Pétursdóttir, Þórunn; Halldórsson, Guðmundur

2017-04-01

Ecosystems that are in equilibrium provide vital resources to local inhabitants, including protection from naturally occurring disasters. Natural vegetation cover has been optimized over many years to retain a maximum of rainfall runoff by increasing the field capacity (FC) of the soil cover, securing water availability during droughts and reducing the flood risk during heavy precipitation events. In this presentation we will present the HydroResilience project, which will assess the effects of ecosystem restoration on the runoff dynamics of rainfall water in Rangárvellir, a restoration area in southern Iceland. The Rangárvellir area presents ideal conditions for such investigations. Dramatic deforestation during the last millennium and year round livestock grazing along with devastating ash depositions during volcanic eruptions and a harsh sub-polar oceanic climate have led to severe degradation in Rangárvellir. Since the beginning of the 20th century diverse restoration measures have been implemented making Rangárvellir an ideal case study to investigate the effects of restoration on hydro-meteorological risk reduction. In this project we will assess and quantify the evolution of water resources in Rangárvellir by assessing the runoff dynamics in the main rivers of Rangárvellir under four main scenarios: i) present conditions, ii) degraded conditions as was the case 100 years ago, iii) under hypothetical fully restored ecosystems and, finally, iv) under conditions of a scenario developed in collaboration with local stakeholder groups to optimize socio-ecological benefits. For this purpose the dynamics of the relevant hydrological processes in the area (incl. river runoff, ground water table, snow cover duration, and soil moisture dynamics) will be reconstructed using hydrological models to run the above mentioned scenarios. The scientific findings and conclusion of this project will generate valuable insights on the effects of land restoration on hydro-meteorological risk reduction. The presentations will outline the main methods used during the project and conclude by providing an outlook on the expected results.

Rainfall-Runoff Dynamics Following Wildfire in Mountainous Headwater Catchments, Alberta, Canada.

NASA Astrophysics Data System (ADS)

Williams, C.; Silins, U.; Bladon, K. D.; Martens, A. M.; Wagner, M. J.; Anderson, A.

2015-12-01

Severe wildfire has been shown to increase the magnitude and advance the timing of rainfall-generated stormflows across a range of hydro-climate regions. Loss of canopy and forest floor interception results in increased net precipitation which, along with the removal of forest organic layers and increased shorter-term water repellency, can result in strongly increased surface flow pathways and efficient routing of precipitation to streams. These abrupt changes have the potential to exacerbate flood impacts and alter the timing of runoff delivery to streams. However, while these effects are well documented in drier temperate mountain regions, changes in post-fire rainfall-runoff processes are less well understood in colder, more northern, snowfall dominated regimes. The objectives of this study are to explore longer term precipitation and runoff dynamics of burned and unburned (reference) watersheds from the Southern Rockies Watershed Project (SRWP) after the 2003 Lost Creek wildfire in the front-range Rocky Mountains of southwestern Alberta, Canada. Streamflow and precipitation were measured in 5 watersheds (3.7 - 10.4 km2) for 10 years following the wildfire (2005-2014). Measurements were collected from a dense network of meteorological and hydrometric stations. Stormflow volume, peak flow, time to peak flow, and total annual streamflow were compared between burned and reference streams. Event-based data were separated into 3 post-fire periods to detect changes in rainfall-runoff dynamics as vegetation regenerated. Despite large increases in post-fire snowpacks and net summer rainfall, rainfall-generated runoff from fire-affected watersheds was not large in comparison to that reported from more temperate snowfall-dominated Rocky Mountain hydrologic settings. High proportions of groundwater contribution to annual runoff regimes (as opposed to surface flow pathways) and groundwater storage were likely contributors to greater watershed resistance to wildfire effects in these northern Rocky Mountain catchments.

Runoff sources and flow paths dynamics in the Andean Páramo.

NASA Astrophysics Data System (ADS)

Correa, Alicia; Windhorst, David; Tetzlaff, Doerthe; Silva, Camila; Crespo, Patricio; Celleri, Rolando; Feyen, Jan; Breuer, Lutz

2017-04-01

The dynamics of runoff sources and flow paths in headwater catchments are still poorly understood. This is even more the case for remote areas such as the Páramo (Alpine grasslands) in the Andes, where these ecosystems act as water towers for a large fraction of the society. Temporal dynamics in water source areas, flow paths and relative age were assessed in a small catchment in the Ecuadorian Andes using data from the Zhurucay Ecohydrological Observatory (7.53 km2). We applied End Member Mixing Analysis, Hydrograph Separation and Inverse Transit Time Proxies to a multi-tracer set of solutes, stable isotopes, pH and electrical conductivity sampled from stream and twelve potential sources during two years. Rainfall, spring water and water from the bottom layers of Histosols (located at the foot of the hillslopes and in the riparian zone) and Andosols (located at the hillslopes) represented the dominant sources for runoff generation. Water coming from Histosols was the main contributor to stream water year-round, in line with a hydrological system that is dominated by pre-event water. Rainfall presented a uniform contribution during the year, while in drier conditions the spring water tripled in contribution. In wetter conditions, the relative age of stream water decreases, when the contributing area of the riparian zone expands, increasing the connectivity with lateral flow from hillslopes to the channel network. Being one of the earliest in the region, this multi-method study improved the understanding of the hydrological processes of headwater catchments and allowed to demonstrate that catchments with relatively homogeneous hydro-climatic conditions are characterized by inter-annual varying source contributions.

Working together to ensure safety at hydro projects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bartel, J.W.

Providing for public safety around a hydroelectric facility can be critically important to the welfare of a hydro-power producer. With this in mind, Wisconsin Electric Power Company and Wisconsin Public Service Corporation have worked together to develop consistent safety signage and several for their hydro projects. Although the two utilities sometimes compete for electric customers, they cooperate to ensure the safety to those customers. Both WE and WPS took steps in 1986 to make their operations safer through involvement in the Wisconsin/Michigan Hydro User Group. The organization has 25 members-primarily of electric utilities and paper companies-who operate hydro facilities inmore » the two states. The two areas that the HUG studied in public safety were signs and warning systems. HUG established a sign committee to study how to increase safety of people around hydro plants through signs, explained Ted Handrick, hydro plant superintendent at WPS. The committee's recommendations led to development of a statewide uniform sign system adopted by all HUG members. The committee used Wisconsin Department of Natural Resources' guidelines for warning signs and portages in developing the signage standards. HUG members are converting to these new sign standards as they replace old signs and/or install new signs. Notices describing the new signage system have been placed near each hydro plant, at boat landings, and in campgrounds. The signs are mounted well above ground level so they can be seen and easily read by recreationalists. Warning systems, in accordance with HUG warning standards, were installed at WE and WPS hydro facilities. These systems alert nearby recreational users of rapid increases in water flow when generating units are turned on or when spillway gates are opened. Soon after the authors installed equipment to remotely operate its hydro facilities, the utility experienced a dramatic increase increase in intrusion on dams and other structures at the projects.« less

A framework for quantification of groundwater dynamics - concepts and hydro(geo-)logical metrics

NASA Astrophysics Data System (ADS)

Haaf, Ezra; Heudorfer, Benedikt; Stahl, Kerstin; Barthel, Roland

2017-04-01

Fluctuation patterns in groundwater hydrographs are generally assumed to contain information on aquifer characteristics, climate and environmental controls. However, attempts to disentangle this information and map the dominant controls have been few. This is due to the substantial heterogeneity and complexity of groundwater systems, which is reflected in the abundance of morphologies of groundwater time series. To describe the structure and shape of hydrographs, descriptive terms like "slow"/ "fast" or "flashy"/ "inert" are frequently used, which are subjective, irreproducible and limited. This lack of objective and refined concepts limit approaches for regionalization of hydrogeological characteristics as well as our understanding of dominant processes controlling groundwater dynamics. Therefore, we propose a novel framework for groundwater hydrograph characterization in an attempt to categorize morphologies explicitly and quantitatively based on perceptual concepts of aspects of the dynamics. This quantitative framework is inspired by the existing and operational eco-hydrological classification frameworks for streamflow. The need for a new framework for groundwater systems is justified by the fundamental differences between the state variable groundwater head and the flow variable streamflow. Conceptually, we extracted exemplars of specific dynamic patterns, attributing descriptive terms for means of systematisation. Metrics, primarily taken from streamflow literature, were subsequently adapted to groundwater and assigned to the described patterns for means of quantification. In this study, we focused on the particularities of groundwater as a state variable. Furthermore, we investigated the descriptive skill of individual metrics as well as their usefulness for groundwater hydrographs. The ensemble of categorized metrics result in a framework, which can be used to describe and quantify groundwater dynamics. It is a promising tool for the setup of a successful similarity classification framework for groundwater hydrographs. However, the overabundance of metrics available calls for a systematic redundancy analysis of the metrics, which we describe in a second study (Heudorfer et al., 2017). Heudorfer, B., Haaf, E., Barthel, R., Stahl, K., 2017. A framework for quantification of groundwater dynamics - redundancy and transferability of hydro(geo-)logical metrics. EGU General Assembly 2017, Vienna, Austria.

Optimizing basin-scale coupled water quantity and water quality man-agement with stochastic dynamic programming

NASA Astrophysics Data System (ADS)

Davidsen, Claus; Liu, Suxia; Mo, Xingguo; Engelund Holm, Peter; Trapp, Stefan; Rosbjerg, Dan; Bauer-Gottwein, Peter

2015-04-01

Few studies address water quality in hydro-economic models, which often focus primarily on optimal allocation of water quantities. Water quality and water quantity are closely coupled, and optimal management with focus solely on either quantity or quality may cause large costs in terms of the oth-er component. In this study, we couple water quality and water quantity in a joint hydro-economic catchment-scale optimization problem. Stochastic dynamic programming (SDP) is used to minimize the basin-wide total costs arising from water allocation, water curtailment and water treatment. The simple water quality module can handle conservative pollutants, first order depletion and non-linear reactions. For demonstration purposes, we model pollutant releases as biochemical oxygen demand (BOD) and use the Streeter-Phelps equation for oxygen deficit to compute the resulting min-imum dissolved oxygen concentrations. Inelastic water demands, fixed water allocation curtailment costs and fixed wastewater treatment costs (before and after use) are estimated for the water users (agriculture, industry and domestic). If the BOD concentration exceeds a given user pollution thresh-old, the user will need to pay for pre-treatment of the water before use. Similarly, treatment of the return flow can reduce the BOD load to the river. A traditional SDP approach is used to solve one-step-ahead sub-problems for all combinations of discrete reservoir storage, Markov Chain inflow clas-ses and monthly time steps. Pollution concentration nodes are introduced for each user group and untreated return flow from the users contribute to increased BOD concentrations in the river. The pollutant concentrations in each node depend on multiple decision variables (allocation and wastewater treatment) rendering the objective function non-linear. Therefore, the pollution concen-tration decisions are outsourced to a genetic algorithm, which calls a linear program to determine the remainder of the decision variables. This hybrid formulation keeps the optimization problem computationally feasible and represents a flexible and customizable method. The method has been applied to the Ziya River basin, an economic hotspot located on the North China Plain in Northern China. The basin is subject to severe water scarcity, and the rivers are heavily polluted with wastewater and nutrients from diffuse sources. The coupled hydro-economic optimiza-tion model can be used to assess costs of meeting additional constraints such as minimum water qual-ity or to economically prioritize investments in waste water treatment facilities based on economic criteria.

Assessing the Influence of Hydrological Connectivity on the Spawning Migration of Atlantic Salmon.

NASA Astrophysics Data System (ADS)

Lazzaro, G.; Soulsby, C.; Tetzlaff, D.; Botter, G.

2016-12-01

Atlantic salmon is an economically and ecologically important fish species, whose survival is critically impacted by successful spawning in headwater gravel-bed rivers. Streamflow dynamics may have a strong control on spawning because adult fish require sufficiently high discharges to move upriver and reach spawning sites. We present a simple outflux-influx model linking the number of female salmon emigrating (i.e. outflux) and returning (i.e. influx) to a small spawning stream in Scotland (the Girnock Burn). The model explicitly accounts for the inter-annual variability of the hydrologic regime and its influence on hydrological connectivity. Model results are then compared against a unique long-term hydro-ecological dataset that includes annual fluxes of immigrant and emigrant salmon and daily discharges for about 40 years. The satisfactory model results confirm that hydrologic variability contributes significantly to the observed dynamics of salmon returns to the Girnock, with a good correlation between the positive (negative) peaks in the immigration dataset and the exceedance (non-exceedance) probability of a threshold flow (0.3 m3/s). Importantly, model performance deteriorates when the inter-annual variability of flow regime is disregarded. The analysis suggests that the hydrological connectivity represents a key feature of riverine systems, which needs to be carefully considered in settings where flow regimes are altered by water abstractions or diversions.

Hydro turbine governor’s power control of hydroelectric unit with sloping ceiling tailrace tunnel

NASA Astrophysics Data System (ADS)

Fu, Liang; Wu, Changli; Tang, Weiping

2018-02-01

The primary frequency regulation and load regulation transient process when the hydro turbine governor is under the power mode of hydropower unit with sloping ceiling tailrace are analysed by field test and numerical simulation in this paper. A simulation method based on “three-zone model” to simulate small fluctuation transient process of the sloping ceiling tailrace is proposed. The simulation model of hydraulic turbine governor power mode is established by governor’s PLC program identification and parameter measurement, and the simulation model is verified by the test. The slow-fast-slow “three-stage regulation” method which can improve the dynamic quality of hydro turbine governor power mode is proposed. The power regulation strategy and parameters are optimized by numerical simulation, the performance of primary frequency regulation and load regulation transient process when the hydro turbine governor is under power mode are improved significantly.

Modeling spatial-temporal dynamics of global wetlands: Comprehensive evaluation of a new sub-grid TOPMODEL parameterization and uncertainties

NASA Astrophysics Data System (ADS)

Zhang, Z.; Zimmermann, N. E.; Poulter, B.

2015-12-01

Simulations of the spatial-temporal dynamics of wetlands is key to understanding the role of wetland biogeochemistry under past and future climate variability. Hydrologic inundation models, such as TOPMODEL, are based on a fundamental parameter known as the compound topographic index (CTI) and provide a computationally cost-efficient approach to simulate global wetland dynamics. However, there remains large discrepancy in the implementations of TOPMODEL in land-surface models (LSMs) and thus their performance against observations. This study describes new improvements to TOPMODEL implementation and estimates of global wetland dynamics using the LPJ-wsl DGVM, and quantifies uncertainties by comparing three digital elevation model products (HYDRO1k, GMTED, and HydroSHEDS) at different spatial resolution and accuracy on simulated inundation dynamics. We found that calibrating TOPMODEL with a benchmark dataset can help to successfully predict the seasonal and interannual variations of wetlands, as well as improve the spatial distribution of wetlands to be consistent with inventories. The HydroSHEDS DEM, using a river-basin scheme for aggregating the CTI, shows best accuracy for capturing the spatio-temporal dynamics of wetland among three DEM products. This study demonstrates the feasibility to capture spatial heterogeneity of inundation and to estimate seasonal and interannual variations in wetland by coupling a hydrological module in LSMs with appropriate benchmark datasets. It additionally highlight the importance of an adequate understanding of topographic indices for simulating global wetlands and show the opportunity to converge wetland estimations in LSMs by identifying the uncertainty associated with existing wetland products.

Sand Waves in Environmental Flows: Insights gained by LES

NASA Astrophysics Data System (ADS)

Sotiropoulos, Fotis

2014-11-01

In fluvial and coastal environments, sediment transport processes induced by near-bed coherent structures in the turbulent boundary layer developing over a mobile sediment bed result in the formation of dynamically rich sand waves, or bed forms, which grow and migrate continuously. Bed form migration alters streambed roughness and provides the primary mechanism for transporting large amounts of sediment through riverine systems impacting the morphology, streambank stability, and ecology of waterways. I will present recent computational advances, which have enabled coupled, hydro-morphodynamic large-eddy simulation (LES) of turbulent flow in mobile-bed open channels. Numerical simulations: 1) elucidate the role of near-bed sweeps in the turbulent boundary layer as the mechanism for initiating the instability of the initially flat sand bed; 2) show how near-bed processes give rise to aperiodic eruptions of suspended sediment at the free surface; and 3) clarify the mechanism via which sand waves migrate. Furthermore, in agreement with recent experimental observations, the computed spectra of the resolved velocity fluctuations above the bed exhibit a distinct spectral gap whose width increases with distance from the bed. The spectral gap delineates the spectrum of turbulence from that of slowly evolving coherent structures associated with sand wave migration. The talk will also present computational results demonstrating the feasibility of carrying out coupled, hydro-morphodynamic LES of large dunes migrating in meandering streams and rivers with embedded hydraulic structures and discuss future challenges and opportunities. This work was supported by NSF Grants EAR-0120914 and EAR-0738726, and National Cooperative Highway Research Program Grant NCHRP-HR 24-33.

Modeling spatial-temporal dynamics of global wetlands: comprehensive evaluation of a new sub-grid TOPMODEL parameterization and uncertainties

NASA Astrophysics Data System (ADS)

Zhang, Z.; Zimmermann, N. E.; Poulter, B.

2015-11-01

Simulations of the spatial-temporal dynamics of wetlands are key to understanding the role of wetland biogeochemistry under past and future climate variability. Hydrologic inundation models, such as TOPMODEL, are based on a fundamental parameter known as the compound topographic index (CTI) and provide a computationally cost-efficient approach to simulate wetland dynamics at global scales. However, there remains large discrepancy in the implementations of TOPMODEL in land-surface models (LSMs) and thus their performance against observations. This study describes new improvements to TOPMODEL implementation and estimates of global wetland dynamics using the LPJ-wsl dynamic global vegetation model (DGVM), and quantifies uncertainties by comparing three digital elevation model products (HYDRO1k, GMTED, and HydroSHEDS) at different spatial resolution and accuracy on simulated inundation dynamics. In addition, we found that calibrating TOPMODEL with a benchmark wetland dataset can help to successfully delineate the seasonal and interannual variations of wetlands, as well as improve the spatial distribution of wetlands to be consistent with inventories. The HydroSHEDS DEM, using a river-basin scheme for aggregating the CTI, shows best accuracy for capturing the spatio-temporal dynamics of wetlands among the three DEM products. The estimate of global wetland potential/maximum is ∼ 10.3 Mkm2 (106 km2), with a mean annual maximum of ∼ 5.17 Mkm2 for 1980-2010. This study demonstrates the feasibility to capture spatial heterogeneity of inundation and to estimate seasonal and interannual variations in wetland by coupling a hydrological module in LSMs with appropriate benchmark datasets. It additionally highlights the importance of an adequate investigation of topographic indices for simulating global wetlands and shows the opportunity to converge wetland estimates across LSMs by identifying the uncertainty associated with existing wetland products.

Suspended Sediment Dynamics in the Macrotidal Seine Estuary (France): 1. Numerical Modeling of Turbidity Maximum Dynamics

NASA Astrophysics Data System (ADS)

Grasso, F.; Verney, R.; Le Hir, P.; Thouvenin, B.; Schulz, E.; Kervella, Y.; Khojasteh Pour Fard, I.; Lemoine, J.-P.; Dumas, F.; Garnier, V.

2018-01-01

Tidal pumping, baroclinic circulation, and vertical mixing are known to be the main mechanisms responsible for the estuarine turbidity maximum (ETM) formation. However, the influence of hydro-meteorological conditions on ETM dynamics is still not properly grasped and requires further investigation to be quantified. Based on a realistic three-dimensional numerical model of the macrotidal Seine Estuary (France) that accounts for mud and sand transport processes, the objective of this study is to quantify the influence of the main forcing (river flow, tides, and waves) on the ETM location and mass changes. As expected, the ETM location is strongly modulated by semidiurnal tidal cycles and fortnightly time scales with a high sensitivity to river flow variations. The ETM mass is clearly driven by the tidal range, characteristic of the tidal pumping mechanism. However, it is not significantly affected by the river flow. Energetic wave conditions substantially influence the ETM mass by contributing up to 44% of the maximum mass observed during spring tides and by increasing the mass by a factor of 3 during mean tides compared to calm wave conditions. This means that neglecting wave forcing can result in significantly underestimating the ETM mass in estuarine environments. In addition, neap-to-spring phasing has a strong influence on ETM location and mass through a hysteresis response associated with the delay for tidal pumping and stratification to fully develop. Finally, simulations show that the uppermost limit of the Seine ETM location did not change notably during the last 35 years; however, the seaward limit migrated few kilometers upstream.

Computational manipulation of a radiative MHD flow with Hall current and chemical reaction in the presence of rotating fluid

NASA Astrophysics Data System (ADS)

Alias Suba, Subbu; Muthucumaraswamy, R.

2018-04-01

A numerical analysis of transient radiative MHD(MagnetoHydroDynamic) natural convective flow of a viscous, incompressible, electrically conducting and rotating fluid along a semi-infinite isothermal vertical plate is carried out taking into consideration Hall current, rotation and first order chemical reaction.The coupled non-linear partial differential equations are expressed in difference form using implicit finite difference scheme. The difference equations are then reduced to a system of linear algebraic equations with a tri-diagonal structure which is solved by Thomas Algorithm. The primary and secondary velocity profiles, temperature profile, concentration profile, skin friction, Nusselt number and Sherwood Number are depicted graphically for a range of values of rotation parameter, Hall parameter,magnetic parameter, chemical reaction parameter, radiation parameter, Prandtl number and Schmidt number.It is recognized that rate of heat transfer and rate of mass transfer decrease with increase in time but they increase with increasing values of radiation parameter and Schmidt number respectively.

Analysis of Arc Characteristics and Flow Field in Arc Chamber of High-Voltage SF6 Auto-Expansion Circuit Breaker

NASA Astrophysics Data System (ADS)

Zhang, Junmin; Chen, Zhang

2008-10-01

A new magnetic hydro-dynamics model for nozzle arc emphasizing the interaction of arc with PTFE (polytetrafluorethylene) vapour is established based on the conservation equations. The interruption of auto-expansion circuit breaker is simulated numerically by finite element method and the influence of PTFE vapour on the arc is analysed with this model. The results reveal that the flow field inside the arc chamber is determined by the arc current, the arcing time, the nozzle arc and the clogging of its thermal boundary. The establishment of quenching pressure relies on both SF6 gas and PTFE vapour that absorbed arc energy in the nozzle. The PTFE vapour leads to an increase in the pressure of nozzle arc obviously, and a decrease in the temperature of arc. But it enhances the temperature of arc at zero current and slows down the decreasing rate of arc temperature as the current decreases.

Global analysis of a renewable micro hydro power generation plant

NASA Astrophysics Data System (ADS)

Rahman, Md. Shad; Nabil, Imtiaz Muhammed; Alam, M. Mahbubul

2017-12-01

Hydroelectric power or Hydropower means the power generated by the help of flowing water with force. It is one the best source of renewable energy in the world. Water evaporates from the earth's surface, forms clouds, precipitates back to earth, and flows toward the ocean. Hydropower is considered a renewable energy resource because it uses the earth's water cycle to generate electricity. As far as Global is concerned, only a small fraction of electricity is generated by hydro-power. The aim of our analysis is to demonstrate and observe the hydropower of the Globe in micro-scale by our experimental setup which is completely new in concept. This paper consists of all the Global and National Scenario of Hydropower. And how we can more emphasize the generation of Hydroelectric power worldwide.

Joint atmospheric-terrestrial water balances for East Africa: a WRF-Hydro case study for the upper Tana River basin

NASA Astrophysics Data System (ADS)

Kerandi, Noah; Arnault, Joel; Laux, Patrick; Wagner, Sven; Kitheka, Johnson; Kunstmann, Harald

2018-02-01

For an improved understanding of the hydrometeorological conditions of the Tana River basin of Kenya, East Africa, its joint atmospheric-terrestrial water balances are investigated. This is achieved through the application of the Weather Research and Forecasting (WRF) and the fully coupled WRF-Hydro modeling system over the Mathioya-Sagana subcatchment (3279 km2) and its surroundings in the upper Tana River basin for 4 years (2011-2014). The model setup consists of an outer domain at 25 km (East Africa) and an inner one at 5-km (Mathioya-Sagana subcatchment) horizontal resolution. The WRF-Hydro inner domain is enhanced with hydrological routing at 500-m horizontal resolution. The results from the fully coupled modeling system are compared to those of the WRF-only model. The coupled WRF-Hydro slightly reduces precipitation, evapotranspiration, and the soil water storage but increases runoff. The total precipitation from March to May and October to December for WRF-only (974 mm/year) and coupled WRF-Hydro (940 mm/year) is closer to that derived from the Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) data (989 mm/year) than from the TRMM (795 mm/year) precipitation product. The coupled WRF-Hydro-accumulated discharge (323 mm/year) is close to that observed (333 mm/year). However, the coupled WRF-Hydro underestimates the observed peak flows registering low but acceptable NSE (0.02) and RSR (0.99) at daily time step. The precipitation recycling and efficiency measures between WRF-only and coupled WRF-Hydro are very close and small. This suggests that most of precipitation in the region comes from moisture advection from the outside of the analysis domain, indicating a minor impact of potential land-precipitation feedback mechanisms in this case. The coupled WRF-Hydro nonetheless serves as a tool in quantifying the atmospheric-terrestrial water balance in this region.

Study of the velocity distribution influence upon the pressure pulsations in draft tube model of hydro-turbine

NASA Astrophysics Data System (ADS)

Sonin, V.; Ustimenko, A.; Kuibin, P.; Litvinov, I.; Shtork, S.

2016-11-01

One of the mechanisms of generation of powerful pressure pulsations in the circuit of the turbine is a precessing vortex core, formed behind the runner at the operation points with partial or forced loads, when the flow has significant residual swirl. To study periodic pressure pulsations behind the runner the authors of this paper use approaches of experimental modeling and methods of computational fluid dynamics. The influence of velocity distributions at the output of the hydro turbine runner on pressure pulsations was studied based on analysis of the existing and possible velocity distributions in hydraulic turbines and selection of the distribution in the extended range. Preliminary numerical calculations have showed that the velocity distribution can be modeled without reproduction of the entire geometry of the circuit, using a combination of two blade cascades of the rotor and stator. Experimental verification of numerical results was carried out in an air bench, using the method of 3D-printing for fabrication of the blade cascades and the geometry of the draft tube of hydraulic turbine. Measurements of the velocity field at the input to a draft tube cone and registration of pressure pulsations due to precessing vortex core have allowed building correlations between the velocity distribution character and the amplitude-frequency characteristics of the pulsations.

Complementary hydro-mechanical coupled finite/discrete element and microseismic modelling to predict hydraulic fracture propagation in tight shale reservoirs

NASA Astrophysics Data System (ADS)

Profit, Matthew; Dutko, Martin; Yu, Jianguo; Cole, Sarah; Angus, Doug; Baird, Alan

2016-04-01

This paper presents a novel approach to predict the propagation of hydraulic fractures in tight shale reservoirs. Many hydraulic fracture modelling schemes assume that the fracture direction is pre-seeded in the problem domain discretisation. This is a severe limitation as the reservoir often contains large numbers of pre-existing fractures that strongly influence the direction of the propagating fracture. To circumvent these shortcomings, a new fracture modelling treatment is proposed where the introduction of discrete fracture surfaces is based on new and dynamically updated geometrical entities rather than the topology of the underlying spatial discretisation. Hydraulic fracturing is an inherently coupled engineering problem with interactions between fluid flow and fracturing when the stress state of the reservoir rock attains a failure criterion. This work follows a staggered hydro-mechanical coupled finite/discrete element approach to capture the key interplay between fluid pressure and fracture growth. In field practice, the fracture growth is hidden from the design engineer and microseismicity is often used to infer hydraulic fracture lengths and directions. Microseismic output can also be computed from changes of the effective stress in the geomechanical model and compared against field microseismicity. A number of hydraulic fracture numerical examples are presented to illustrate the new technology.

High resolution mapping of riffle-pool dynamics based on ADCP and close-range remote sensing data

NASA Astrophysics Data System (ADS)

Salmela, Jouni; Kasvi, Elina; Alho, Petteri

2017-04-01

Present development of mobile laser scanning (MLS) and close-range photogrammetry with unmanned aerial vehicle (UAV) enable us to create seamless digital elevation models (DEMs) of the riverine environment. Remote-controlled flow measurement platforms have also improved spatio-temporal resolution of the flow field data. In this study, acoustic Doppler current profiler (ADCP) attached to remote-controlled mini-boat, UAV-based bathymetry and MLS techniques were utilized to create the high-resolution DEMs of the river channel. These high-resolution measurements can be used in many fluvial applications such as computational fluid dynamics, channel change detection, habitat mapping or hydro-electric power plant planning. In this study we aim: 1) to analyze morphological changes of river channel especially riffle and pool formations based on fine-scale DEMs and ADCP measurements, 2) to analyze flow fields and their effect on morphological changes. The interest was mainly focused on reach-scale riffle-pool dynamics within two-year period of 2013 and 2014. The study was performed in sub-arctic meandering Pulmankijoki River located in Northern Finland. The river itself has shallow and clear water and sandy bed sediment. Discharge remains typically below 10 m3s-1 most of the year but during snow melt period in spring the discharge may exceed 70 m3s-1. We compared DEMs and ADCP measurements to understand both magnitude and spatio-temporal change of the river bed. Models were accurate enough to study bed form changes and locations and persistence of riffles and pools. We analyzed their locations with relation to flow during the peak and low discharge. Our demonstrated method has improved significantly spatio-temporal resolution of riverine DEMs compared to other cross-sectional and photogrammetry based models. Together with flow field measurements we gained better understanding of riverbed-water interaction

HydroSHEDS: A global comprehensive hydrographic dataset

NASA Astrophysics Data System (ADS)

Wickel, B. A.; Lehner, B.; Sindorf, N.

2007-12-01

The Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales (HydroSHEDS) is an innovative product that, for the first time, provides hydrographic information in a consistent and comprehensive format for regional and global-scale applications. HydroSHEDS offers a suite of geo-referenced data sets, including stream networks, watershed boundaries, drainage directions, and ancillary data layers such as flow accumulations, distances, and river topology information. The goal of developing HydroSHEDS was to generate key data layers to support regional and global watershed analyses, hydrological modeling, and freshwater conservation planning at a quality, resolution and extent that had previously been unachievable. Available resolutions range from 3 arc-second (approx. 90 meters at the equator) to 5 minute (approx. 10 km at the equator) with seamless near-global extent. HydroSHEDS is derived from elevation data of the Shuttle Radar Topography Mission (SRTM) at 3 arc-second resolution. The original SRTM data have been hydrologically conditioned using a sequence of automated procedures. Existing methods of data improvement and newly developed algorithms have been applied, including void filling, filtering, stream burning, and upscaling techniques. Manual corrections were made where necessary. Preliminary quality assessments indicate that the accuracy of HydroSHEDS significantly exceeds that of existing global watershed and river maps. HydroSHEDS was developed by the Conservation Science Program of the World Wildlife Fund (WWF) in partnership with the U.S. Geological Survey (USGS), the International Centre for Tropical Agriculture (CIAT), The Nature Conservancy (TNC), and the Center for Environmental Systems Research (CESR) of the University of Kassel, Germany.

Neuro-Fuzzy Computational Technique to Control Load Frequency in Hydro-Thermal Interconnected Power System

NASA Astrophysics Data System (ADS)

Prakash, S.; Sinha, S. K.

2015-09-01

In this research work, two areas hydro-thermal power system connected through tie-lines is considered. The perturbation of frequencies at the areas and resulting tie line power flows arise due to unpredictable load variations that cause mismatch between the generated and demanded powers. Due to rising and falling power demand, the real and reactive power balance is harmed; hence frequency and voltage get deviated from nominal value. This necessitates designing of an accurate and fast controller to maintain the system parameters at nominal value. The main purpose of system generation control is to balance the system generation against the load and losses so that the desired frequency and power interchange between neighboring systems are maintained. The intelligent controllers like fuzzy logic, artificial neural network (ANN) and hybrid fuzzy neural network approaches are used for automatic generation control for the two area interconnected power systems. Area 1 consists of thermal reheat power plant whereas area 2 consists of hydro power plant with electric governor. Performance evaluation is carried out by using intelligent (ANFIS, ANN and fuzzy) control and conventional PI and PID control approaches. To enhance the performance of controller sliding surface i.e. variable structure control is included. The model of interconnected power system has been developed with all five types of said controllers and simulated using MATLAB/SIMULINK package. The performance of the intelligent controllers has been compared with the conventional PI and PID controllers for the interconnected power system. A comparison of ANFIS, ANN, Fuzzy and PI, PID based approaches shows the superiority of proposed ANFIS over ANN, fuzzy and PI, PID. Thus the hybrid fuzzy neural network controller has better dynamic response i.e., quick in operation, reduced error magnitude and minimized frequency transients.

Streamflow variability over the 1881–2011 period in northern Quebec: comparison of hydrological reconstructions based on tree rings and geopotential height field reanalysis

DOE PAGES

Brigode, Pierre; Brissette, Francois; Nicault, Antoine; ...

2016-09-06

Over the last decades, different methods have been used by hydrologists to extend observed hydro-climatic time series, based on other data sources, such as tree rings or sedimentological datasets. For example, tree ring multi-proxies have been studied for the Caniapiscau Reservoir in northern Québec (Canada), leading to the reconstruction of flow time series for the last 150 years. In this paper, we applied a new hydro-climatic reconstruction method on the Caniapiscau Reservoir and compare the obtained streamflow time series against time series derived from dendrohydrology by other authors on the same catchment and study the natural streamflow variability over themore » 1881–2011 period in that region. This new reconstruction is based not on natural proxies but on a historical reanalysis of global geopotential height fields, and aims firstly to produce daily climatic time series, which are then used as inputs to a rainfall–runoff model in order to obtain daily streamflow time series. The performances of the hydro-climatic reconstruction were quantified over the observed period, and showed good performances, in terms of both monthly regimes and interannual variability. The streamflow reconstructions were then compared to two different reconstructions performed on the same catchment by using tree ring data series, one being focused on mean annual flows and the other on spring floods. In terms of mean annual flows, the interannual variability in the reconstructed flows was similar (except for the 1930–1940 decade), with noteworthy changes seen in wetter and drier years. For spring floods, the reconstructed interannual variabilities were quite similar for the 1955–2011 period, but strongly different between 1880 and 1940. Here, the results emphasize the need to apply different reconstruction methods on the same catchments. Indeed, comparisons such as those above highlight potential differences between available reconstructions and, finally, allow a retrospective analysis of the proposed reconstructions of past hydro-climatological variabilities.« less

Streamflow variability over the 1881–2011 period in northern Quebec: comparison of hydrological reconstructions based on tree rings and geopotential height field reanalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brigode, Pierre; Brissette, Francois; Nicault, Antoine

Over the last decades, different methods have been used by hydrologists to extend observed hydro-climatic time series, based on other data sources, such as tree rings or sedimentological datasets. For example, tree ring multi-proxies have been studied for the Caniapiscau Reservoir in northern Québec (Canada), leading to the reconstruction of flow time series for the last 150 years. In this paper, we applied a new hydro-climatic reconstruction method on the Caniapiscau Reservoir and compare the obtained streamflow time series against time series derived from dendrohydrology by other authors on the same catchment and study the natural streamflow variability over themore » 1881–2011 period in that region. This new reconstruction is based not on natural proxies but on a historical reanalysis of global geopotential height fields, and aims firstly to produce daily climatic time series, which are then used as inputs to a rainfall–runoff model in order to obtain daily streamflow time series. The performances of the hydro-climatic reconstruction were quantified over the observed period, and showed good performances, in terms of both monthly regimes and interannual variability. The streamflow reconstructions were then compared to two different reconstructions performed on the same catchment by using tree ring data series, one being focused on mean annual flows and the other on spring floods. In terms of mean annual flows, the interannual variability in the reconstructed flows was similar (except for the 1930–1940 decade), with noteworthy changes seen in wetter and drier years. For spring floods, the reconstructed interannual variabilities were quite similar for the 1955–2011 period, but strongly different between 1880 and 1940. Here, the results emphasize the need to apply different reconstruction methods on the same catchments. Indeed, comparisons such as those above highlight potential differences between available reconstructions and, finally, allow a retrospective analysis of the proposed reconstructions of past hydro-climatological variabilities.« less

Monitoring the Dynamics of Water Flow at a High-Mountain Permafrost Site Using Electrical Self-Potential Measurements

NASA Astrophysics Data System (ADS)

Kemna, A.; Weigand, M.; Wagner, F.; Hilbich, C.; Hauck, C.

2016-12-01

Flow of (liquid) water plays a crucial role in the dynamics of coupled thermo-hydro-mechanical processes in terrestrial permafrost systems. To better understand these processes in the active layer of permafrost regions, with the ultimate goal of adequately incorporating them in numerical models for improved scenario prediction, monitoring approaches offering high spatial and temporal resolution, areal coverage, and especially sensitivity to subsurface water flow, are highly desired. This particularly holds for high-mountain slopes, where strong variability in topography, precipitation, and snow cover, along with significant subsurface soil/rock heterogeneity, gives rise to complex spatio-temporal patterns of water flow during seasonal thawing and freezing periods. The electrical self-potential (SP) method is well known to, in theory, meeting the above monitoring demands by measuring the electrical streaming potential which is generated at the microscopic scale when water flows along electrically non-neutral interfaces. Despite its inherent sensitivity to subsurface water flow, the SP method has not yet been used for the monitoring of high-mountain permafrost sites. We here present first results from an SP monitoring survey conducted at the Schilthorn (2970 m asl) in the Bernese Alps, Switzerland, where SP data have been collected since September 2013 at a sampling rate of 10 min on a permanently installed array of 12 non-polarizing electrodes covering an area of 35 m by 15 m. While the SP time series exhibit systematic daily variations, with part of the signal clearly correlated with temperature, in particular in the snow-free periods, the largest temporal changes in the SP signal occur in spring, when the snow cover melts and thawing sets on in the active layer. The period of higher temporal SP variations continues until autumn, when the signal gradually returns to relatively low variations, coinciding with the freezing of the ground. Our results suggest that the SP method is a suitable tool for the monitoring of seasonal water flow dynamics at high-mountain permafrost sites. Current work is directed towards an improved field setup, as well as the quantitative analysis of the SP data based on laboratory calibration measurements.

Environmental flows in hydro-economic models

NASA Astrophysics Data System (ADS)

Pereau, Jean-Christophe; Pryet, Alexandre

2018-03-01

The protection of environmental flows, as a management objective for a regulating agency, needs to be consistent with the aquifer water balance and the degree of resource renewability. A stylized hydro-economic model is used where natural recharge, which sustains environmental flows, is considered both in the aquifer water budget and in the welfare function as ecosystem damage. Groundwater recharge and the associated natural drainage may be neglected for aquifers containing fossil water, where the groundwater is mined. However, when dealing with an aquifer that constitutes a renewable resource, for which recharge is not negligible, natural drainage should explicitly appear in the water budget. In doing so, the optimum path of net extraction rate does not necessarily converge to the recharge rate, but depends on the costs associated with ecosystem damages. The optimal paths and equilibrium values for the water volume and water extraction are analytically derived, and numerical simulations based on the Western La Mancha aquifer (southwest Spain) illustrate the theoretical results of the study.

Transient flow analysis linked to fast pressure disturbance monitored in pipe systems

NASA Astrophysics Data System (ADS)

Kueny, J. L.; Lourenco, M.; Ballester, J. L.

2012-11-01

EDF Hydro Division has launched the RENOUVEAU program in order to increase performance and improve plant availability through anticipation. Due to this program, a large penstocks fleet is equipped with pressure transducers linked to a special monitoring system. Any significant disturbance of the pressure is captured in a snapshot and the waveform of the signal is stored and analyzed. During these transient states, variations in flow are unknown. In order to determine the structural impact of such overpressure occurring during complex transients conditions over the entire circuit, EDF DTG has asked ENSE3 GRENOBLE to develop a code called ACHYL CF*. The input data of ACHYL CF are circuit topology and pressure boundaries conditions. This article provide a description of the computer code developed for modeling the transient flow in a pipe network using the signals from pressure transducers as boundary conditions. Different test cases will be presented, simulating real hydro power plants for which measured pressure signals are available.

LDV survey of cavitation and resonance effect on the precessing vortex rope dynamics in the draft tube of Francis turbines

NASA Astrophysics Data System (ADS)

Favrel, A.; Müller, A.; Landry, C.; Yamamoto, K.; Avellan, F.

2016-11-01

The large-scale penetration of the electrical grid by intermittent renewable energy sources requires a continuous operating range extension of hydropower plants. This causes the formation of unfavourable flow patterns in the draft tube of turbines and pump-turbines. At partial load operation, a precessing cavitation vortex rope is formed at the Francis turbine runner outlet, acting as an excitation source for the hydraulic system. In case of resonance, the resulting high-amplitude pressure pulsations can put at risk the stability of the machine and of the electrical grid to which it is connected. It is therefore crucial to understand and accurately simulate the underlying physical mechanisms in such conditions. However, the exact impact of cavitation and hydro-acoustic resonance on the flow velocity fluctuations in the draft tube remains to be established. The flow discharge pulsations expected to occur in the draft tube in resonance conditions have for instance never been verified experimentally. In this study, two-component Laser Doppler Velocimetry is used to investigate the axial and tangential velocity fluctuations at the runner outlet of a reduced scale physical model of a Francis turbine. The investigation is performed for a discharge equal to 64 % of the nominal value and three different pressure levels in the draft tube, including resonance and cavitation-free conditions. Based on the convective pressure fluctuations induced by the vortex precession, the periodical velocity fluctuations over one typical precession period are recovered by phase averaging. The impact of cavitation and hydro-acoustic resonance on both axial and tangential velocity fluctuations in terms of amplitude and phase shift is highlighted for the first time. It is shown that the occurrence of resonance does not have significant effects on the draft tube velocity fields, suggesting that the synchronous axial velocity fluctuations are surprisingly negligible compared to the velocity fluctuations induced by the vortex precession.

Runaway transient simulation of a model Kaplan turbine

NASA Astrophysics Data System (ADS)

Liu, S.; Zhou, D.; Liu, D.; Wu, Y.; Nishi, M.

2010-08-01

The runaway transient is a typical transient process of a hydro power unit, where the rotational speed of a turbine runner rapidly increases up to the runaway speed under a working head as the guide vanes cannot be closed due to some reason at the load rejection. In the present paper, the characteristics of the runaway transient of a model Kaplan turbine having ns = 479(m-kW) is simulated by using a time-dependent CFD technique where equation of rotational motion of runner, continuity equation and unsteady RANS equations with RNG k-epsilon turbulence model are solved iteratively. In the calculation, unstructured mesh is used to the whole flow passage, which consists of several sub-domains: entrance, casing, stay vanes + guide vanes, guide section, runner and draft tube. And variable speed sliding mesh technique is used to exchange interface flow information between moving part and stationary part, and three-dimensional unstructured dynamic mesh technique is also adopted to ensure mesh quality. Two cases were treated in the simulation of runaway transient characteristics after load rejection: one is the rated operating condition as the initial condition, and the other is the condition at the maximum head. Regarding the runaway speed, the experimental speed is 1.45 times the initial speed and the calculation is 1.47 times the initial for the former case. In the latter case, the experiment and the calculation are 1.67 times and 1.69 times respectively. From these results, it is recognized that satisfactorily prediction will be possible by using the present numerical method. Further, numerical results show that the swirl in the draft-tube flow becomes stronger in the latter part of the transient process so that a vortex rope will occur in the draft tube and its precession will cause the pressure fluctuations which sometimes affect the stability of hydro power system considerably.

Differential behaviour of Escherichia coli and Campylobacter spp. in a stream draining dairy pasture.

PubMed

Stott, Rebecca; Davies-Colley, Robert; Nagels, John; Donnison, Andrea; Ross, Colleen; Muirhead, Richard

2011-03-01

The faecal indicator bacterium Escherichia coli and thermotolerant Campylobacter spp., which are potentially pathogenic, were investigated in the Toenepi Stream draining a pastoral catchment dominated by dairying. Bacteria concentrations were monitored routinely at fortnightly intervals over 12 months and intensively during storm events to compare the transport dynamics of bacterial indicator and pathogen under varying hydro-meteorological conditions. Routine monitoring indicated median concentrations of 345 E. coli MPN 100 ml(-1) and relatively low concentrations of 2.3 Campylobacter MPN 100 ml(-1). The bacterial flux was three orders of magnitude greater under elevated stream flow compared with base-flow. E. coli peak concentrations occurred very close to the turbidity peak and consistently ahead of the Campylobacter spp. peak (which was close to the hydrograph peak). We postulate that, under flood conditions, the E. coli peak reflects the entrainment and mobilisation of in-stream stores on the flood wave front. In contrast, Campylobacter spp. are derived from wash-in from land stores upstream and have travelled at the mean water velocity which is slower than the speed of the flood wave. Our findings of different dynamics for E. coli and Campylobacter spp. suggest that mitigation to reduce faecal microbial impacts from farms will need to take account of these differences.

Modeling Reservoir-River Networks in Support of Optimizing Seasonal-Scale Reservoir Operations

NASA Astrophysics Data System (ADS)

Villa, D. L.; Lowry, T. S.; Bier, A.; Barco, J.; Sun, A.

2011-12-01

HydroSCOPE (Hydropower Seasonal Concurrent Optimization of Power and the Environment) is a seasonal time-scale tool for scenario analysis and optimization of reservoir-river networks. Developed in MATLAB, HydroSCOPE is an object-oriented model that simulates basin-scale dynamics with an objective of optimizing reservoir operations to maximize revenue from power generation, reliability in the water supply, environmental performance, and flood control. HydroSCOPE is part of a larger toolset that is being developed through a Department of Energy multi-laboratory project. This project's goal is to provide conventional hydropower decision makers with better information to execute their day-ahead and seasonal operations and planning activities by integrating water balance and operational dynamics across a wide range of spatial and temporal scales. This presentation details the modeling approach and functionality of HydroSCOPE. HydroSCOPE consists of a river-reservoir network model and an optimization routine. The river-reservoir network model simulates the heat and water balance of river-reservoir networks for time-scales up to one year. The optimization routine software, DAKOTA (Design Analysis Kit for Optimization and Terascale Applications - dakota.sandia.gov), is seamlessly linked to the network model and is used to optimize daily volumetric releases from the reservoirs to best meet a set of user-defined constraints, such as maximizing revenue while minimizing environmental violations. The network model uses 1-D approximations for both the reservoirs and river reaches and is able to account for surface and sediment heat exchange as well as ice dynamics for both models. The reservoir model also accounts for inflow, density, and withdrawal zone mixing, and diffusive heat exchange. Routing for the river reaches is accomplished using a modified Muskingum-Cunge approach that automatically calculates the internal timestep and sub-reach lengths to match the conditions of each timestep and minimize computational overhead. Power generation for each reservoir is estimated using a 2-dimensional regression that accounts for both the available head and turbine efficiency. The object-oriented architecture makes run configuration easy to update. The dynamic model inputs include inflow and meteorological forecasts while static inputs include bathymetry data, reservoir and power generation characteristics, and topological descriptors. Ensemble forecasts of hydrological and meteorological conditions are supplied in real-time by Pacific Northwest National Laboratory and are used as a proxy for uncertainty, which is carried through the simulation and optimization process to produce output that describes the probability that different operational scenario's will be optimal. The full toolset, which includes HydroSCOPE, is currently being tested on the Feather River system in Northern California and the Upper Colorado Storage Project.

Numerical Simulation of Hydro-mechanical Deep Drawing — A Study on the Effect of Process Parameters on Drawability and Thickness Variation

NASA Astrophysics Data System (ADS)

Singh, Swadesh Kumar; Kumar, D. Ravi

2005-08-01

Hydro-mechanical deep drawing is a process for producing cup shaped parts with the assistance of a pressurized fluid. In the present work, numerical simulation of the conventional and counter pressure deep drawing processes has been done with the help of a finite element method based software. Simulation results were analyzed to study the improvement in drawability by using hydro-mechanical processes. The thickness variations in the drawn cups were analyzed and also the effect of counter pressure and oil gap on the thickness distribution was studied. Numerical simulations were also used for the die design, which combines both drawing and ironing processes in a single operation. This modification in the die provides high drawability, facilitates smooth material flow, gives more uniform thickness distribution and corrects the shape distortion.

75 FR 70729 - Blue Heron Hydro, LLC; Notice of Applications Tendered for Filing With the Commission and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-18

... person believes that an additional scientific study should be conducted in order to form an adequate... containing 6 horizontal mixed flow turbines directly connected to 6 submersible generator units for a total... the existing intake tower, each containing 6 horizontal mixed flow turbines directly connected to 6...

78 FR 52172 - Don W. Gilbert Hydro Power, LLC; Notice of Availability of Environmental Assessment

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-22

... kilowatts (kW) and would utilize the flow from several unnamed springs that converge into an unnamed channel... to the existing stream channel that flows into the Bear River; (5) a 150-foot-long, 480-volt... Construction Implement industry-standard erosion control measures to minimize erosion and sedimentation; Stop...

Hydro-Thermal Fatigue Resistance Measurements on Polymer Interfaces

NASA Astrophysics Data System (ADS)

Gurumurthy, Charan K.; Kramer, Edward J.; Hui, Chung-Yuen

1998-03-01

We have developed a new technique based on a fiber optic displacement sensor for rapid determination of hydro-thermal fatigue crack growth rate per cycle (da/dN) of an epoxy/polyimide interface used in flip chip attach microelectronic assembly. The sample is prepared as a trilayered cantilever beam by capillary flow of the epoxy underfill over a polyimide coated metallic beam. During hydro-thermal cycling the crack growth along the interface (from the free end) changes the displacement of this end of the beam and we measure the free end displacement at the lowest temperature in each hydro-thermal cycle. The change in beam displacement is then converted into crack growth rate (da/dN). da/dN depends on the maximum change in the strain energy release rate of the crack and the phase angle in each cycle. The relation between da/dN and maximum strain energy release rate characterizes the fatigue crack growth resistance of the interface. We have developed and used a simple model anhydride cured and a commercially available PMDA/ODA passivation for this study.

Method to support Total Maximum Daily Load development using hydrologic alteration as a surrogate to address aquatic life impairment in New Jersey streams

USGS Publications Warehouse

Kennen, Jonathan G.; Riskin, Melissa L.; Reilly, Pamela A.; Colarullo, Susan J.

2013-01-01

More than 300 ambient monitoring sites in New Jersey have been identified by the New Jersey Department of Environmental Protection (NJDEP) in its integrated water-quality monitoring and assessment report (that is, the 305(b) Report on general water quality and 303(d) List of waters that do not support their designated uses) as being impaired with respect to aquatic life; however, no unambiguous stressors (for example, nutrients or bacteria) have been identified. Because of the indeterminate nature of the broad range of possible impairments, surrogate measures that more holistically encapsulate the full suite of potential environmental stressors need to be developed. Streamflow alteration resulting from anthropogenic changes in the landscape is one such surrogate. For example, increases in impervious surface cover (ISC) commonly cause increases in surface runoff, which can result in “flashy” hydrology and other changes in the stream corridor that are associated with streamflow alteration. The NJDEP has indicated that methodologies to support a hydrologically based Total Maximum Daily Load (hydro-TMDL) need to be developed in order to identify hydrologic targets that represent a minimal percent deviation from a baseline condition (“minimally altered”) as a surrogate measure to meet criteria in support of designated uses. The primary objective of this study was to develop an applicable hydro-TMDL approach to address aquatic-life impairments associated with hydrologic alteration for New Jersey streams. The U.S. Geological Survey, in cooperation with the NJDEP, identified 51 non- to moderately impaired gaged streamflow sites in the Raritan River Basin for evaluation. Quantile regression (QR) analysis was used to compare flow and precipitation records and identify baseline hydrographs at 37 of these sites. At sites without an appropriately long period of record (POR) or where a baseline hydrograph could not be identified with QR, a rainfall-runoff model was used to develop simulated baseline hydrographs. The hydro-TMDL approach provided an opportunity to evaluate proportional differences in flow attributes between observed and baseline hydrographs and to develop complementary flow-ecology response relations at a subset of Raritan River Basin sites where available flow and ecological information overlapped. The New Jersey Stream Classification Tool (NJSCT) was used to determine the stream class of all 51 study sites by using either an observed or a simulated baseline hydrograph. Two New Jersey stream classes (A and C) were evaluated to help characterize the unique hydrology of the Raritan River Basin. In general, class C streams (1.99–40.7 square miles) had smaller drainage areas than class A streams (0.7–785 square miles). Many of the non-impaired and moderately impaired class A and C streams in the Raritan River Basin were found to have significant hydrologic alteration as indicated by numerous flow values that fell outside the established 25th-to-75th- and the more conservative 40th-to-60th-percentile boundaries. However, percent deviations for the class C streams (defined as moderately stable streams with moderately high base-flow contributions) were, in general, much larger than those for the class A streams (defined as semiflashy streams characterized by moderately low base flow). The greater deviations for class C streams in the hydro-TMDL assessments likely resulted from comparisons that were based solely on simulated baseline hydrographs, which were developed without considering any anthropogenic influences in the basin. In contrast, comparisons for many of the class A streams were made by using an observed baseline, which already includes an implicit level of ISC and other human influences on the landscape. By using the hydro-TMDL approach, numerous flow deviations were identified that were indicative of streams that are highly regulated by reservoirs or dams, streams that are affected by increasing amounts of surface runoff resulting from ISC, and streams that are affected by water abstraction (that is, groundwater or surface-water withdrawals used for agricultural and human supply). Eight of the reservoir- and (or) dam-affected sites showed flow deviations that are indicative of flow-managed systems. For example, indices that account for the timing and magnitude of high and low flows were often found to fall outside the 25th-to-75th-percentile range. In general, at regulated class C streams, annual summer low flows are arriving later and tend to be lower, and high flows are arriving earlier with higher magnitudes of longer duration. At class A streams, high and low flows are arriving later with an overall increase in discharge with respect to the prereservoir baseline conditions. The drainage basins of eight of the study sites had large values of ISC (>10 percent), most likely as a result of expanding urban development. In general, the magnitude and frequency of high flows at class A and C sites with high ISC are increasing and were commonly found to fall outside the 25th-to-75th-percentile range. Additionally, magnitudes of low flows are becoming lower and, although the timing of high flows was highly variable, low-flow events appeared to be arriving earlier than would be expected under normal low-flow conditions. Three of the study sites appeared to be affected by hydrologic changes associated with water abstraction. At these sites, the timing of flows appeared to be altered. For example, low flows tended to arrive earlier and high flows arrived later at two of the three sites. Additionally, the magnitude and duration of low flows were commonly less than the 25th-percentile value and the duration of high flows appeared to increase. A reduced set of hydrologic and ecological variables was used to develop univariate and multivariate flow-ecology response models for the aquatic-invertebrate assemblage. Many hydrologic variables accounting for the duration, magnitude, frequency, and timing of flows were significantly correlated with ecological response. Multiple linear regression (MLR) models were developed to provide a more holistic evaluation of the combined effects of hydrologic alteration and to identify models with two or three hydrologic variables that account for a significant proportion of the variability in invertebrate-assemblage condition as represented by assemblage metric scores. MLR models, derived on the basis of hydrologic attributes, accounted for 35 to 75 percent of the variability in assemblage condition. The hydro-TMDL method developed herein for non- to moderately impaired Raritan River Basin streams utilizes a “surrogate” approach in place of the traditional “pollutant of concern” approach commonly used for TMDL development. Managers can use the results obtained by using the hydro-TMDL method to offset the effects of impervious-surface runoff and altered streamflow and to implement measures designed to achieve the necessary load reductions for the “pollutant of concern” (that is, percentage deviations of stream-class-specific flow-index values outside the established 25th-to-75th-percentile range). In this case, such deviations could represent all or a subset of the altered flow indices that prevent the stream from meeting designated aquatic-life criteria. This hydro-TMDL uses a reference, or attainment stream approach for developing the TMDL endpoint. That is, either observed or simulated baseline hydrographs were selected as appropriate reference conditions on the basis of results of QR analysis and watershed modeling procedures, respectively. For any stream in the Raritan River Basin evaluated as part of this study, the hydro-TMDL can be expressed as the greatest amount of deviation in flow a stream can exhibit without violating the stream’s designated aquatic-life criteria. Use of this surrogate approach is appropriate because flows that fall outside the established percentile ranges are ultimately a function of many anthropogenic modifications of the landscape, including the amount of stormwater runoff generated from impervious surfaces within a given basin, the presence of manmade structures designed to retain or divert water, the magnitude of ground- and surface-water abstraction, and the presence of water-supply processes implemented to support human needs. In addition, the stream-type-specific flow indices used as the basis for the hydro-TMDL approach are useful for representing the hydrologic conditions of class A and C streams/basins because they incorporate the full spectrum of flow conditions (very low to very high) that occur in the stream system over a long period of time, as well as those flow properties that change as a result of seasonal variation. Ultimately, an estimate of the maximum percentage flow reduction that could be allowed will be needed to address the aquatic-life impairments in many of the study streams in the Raritan River Basin and will be necessary for identifying appropriate target flow conditions for hydro-TMDL implementation. As described in this report, a target flow value equal to the 25th- or 75th-percentile flow rate could be selected as the point useful for setting specific hydrologic targets. This selection, however, is a management decision that could vary depending on the designated use of the stream or other regulatory factors (for example, water-supply protection, trout production, antidegradation policies, or special protection designations). In New Jersey streams where no unambiguous stressors can be identified, State monitoring agencies, such as the NJDEP, could choose to require the implementation of a flow-based TMDL that not only supports designated uses, but meets the regulatory requirements under the Clean Water Act, and represents a balance between water supply intended to meet human needs and the conservation of ecosystem integrity.

Governance and decision making in complex socio-hydrological systems

NASA Astrophysics Data System (ADS)

Elshorbagy, Amin; Wheater, Howard; Gober, Patricia; Hassanzadeh, Elmira

2017-04-01

The transboundary Saskatchewan River, originating in the Canadian Rockies in Alberta, flows through Saskatchewan and Manitoba and discharges its water into Lake Winnipeg. It supports irrigated agriculture, hydropower generation, flood protection, municipal water supplies, mining, recreation, and environmental services across a large area and in multiple administrative jurisdictions. Managing the region's water-based economic activities and environmental services, requires decisions at a variety of scales to incorporate competing values and priorities about water use. Current inter-provincial allocations are based on the 1969 Master Agreement of Water Apportionment whereby upstream Alberta must release one-half of the annual natural flows of the Saskatchewan River to Saskatchewan, which in turn must pass one-half of the residual natural flow to the Province of Manitoba. This analysis uses a hydro-economic simulation model, SWAMP, to examine risk-based tradeoffs in Saskatchewan for various types of water use including, agriculture, energy, and flood protection under various scenarios of water availability. The eco-hydrological effects of the scenarios on the largest inland delta in North America - the Saskatchewan River Delta - are also shown. Results enable decision makers to weigh the costs and benefits of implementing particular sector-based future development strategies. Assuming net provincial benefit as a single monetary indicator of economic value, the effects of various scenarios of environmental and policy changes are quantified Results show that improving irrigation technology and expanding irrigated lands in Alberta will positively affect the province's economic development and have compound effects downstream on hydropower generation, environmental flows and the economies of Saskatchewan and Manitoba. The implementation of similar policies in Saskatchewan will have different downstream impacts because of the large hydro-power capacity downstream in Manitoba. The model highlights the spatial tradeoffs across the three provinces and sectoral trade-offs among the differing water uses. These trade-offs represent challenging dilemmas for water management decisions in a complex system. The study reveals the need for a holistic framework of water resources analysis that can dynamically capture the feedback loops among hydrological, social, and administrative/political analysis units to support public discussion of critical water tradeoffs and a consensual water value framework to guide future development decisions.

Effects of Scandinavian hydro power on storage needs in a fully renewable European power system for various transmission capacity scenarios

NASA Astrophysics Data System (ADS)

Kies, Alexander; Nag, Kabitri; von Bremen, Lueder; Lorenz, Elke; Heinemann, Detlev

2015-04-01

The penetration of renewable energies in the European power system has increased in the last decades (23.5% share of renewables in the gross electricity consumption of the EU-28 in 2012) and is expected to increase further up to very high shares close to 100%. Planning and organizing this European energy transition towards sustainable power sources will be one of the major challenges of the 21st century. It is very likely that in a fully renewable European power system wind and photovoltaics (pv) will contribute the largest shares to the generation mix followed by hydro power. However, feed-in from wind and pv is due to the weather dependant nature of their resources fluctuating and non-controllable. To match generation and consumption several solutions and their combinations were proposed like very high backup-capacities of conventional power generation (e.g. fossile or nuclear), storages or the extension of the transmission grid. Apart from those options hydro power can be used to counterbalance fluctuating wind and pv generation to some extent. In this work we investigate the effects of hydro power from Norway and Sweden on residual storage needs in Europe depending on the overlaying grid scenario. High temporally and spatially resolved weather data with a spatial resolution of 7 x 7 km and a temporal resolution of 1 hour was used to model the feed-in from wind and pv for 34 investigated European countries for the years 2003-2012. Inflow into hydro storages and generation by run-of-river power plants were computed from ERA-Interim reanalysis runoff data at a spatial resolution of 0.75° x 0.75° and a daily temporal resolution. Power flows in a simplified transmission grid connecting the 34 European countries were modelled minimizing dissipation using a DC-flow approximation. Previous work has shown that hydro power, namely in Norway and Sweden, can reduce storage needs in a renewable European power system by a large extent. A 15% share of hydro power in Europe can reduce storage needs by up to 50% with respect to stored energy. This requires however large transmission capacities between the major hydro power producers in Scandinavia and the largest consumers of electrical energy in Western Europe. We show how Scandinavian hydro power can reduce storage needs in dependency of the transmission grid for two fully renewable scenarios: The first one has its wind and pv generation capacities distributed according to an empirically derived approach. The second scenario has an optimal spatial distribution to minimize storage needs distribution of wind and pv generation capacities across Europe. We show that in both cases hydro power together with a well developed transmission grid has the potential to contribute a large share to the solution of the generation-consumption mismatch problem. The work is part of the RESTORE 2050 project (BMBF) that investigates the requirements for cross-country grid extensions, usage of storage technologies and capacities and the development of new balancing technologies.

Generation of Alfvenic Waves and Turbulence in Magnetic Reconnection Jets

NASA Astrophysics Data System (ADS)

Hoshino, M.

2014-12-01

The magneto-hydro-dynamic (MHD) linear stability for the plasma sheet with a localized bulk plasma flow parallel to the neutral sheet is investigated. We find three different unstable modes propagating parallel to the anti-parallel magnetic field line, and we call them as "streaming　tearing'', "streaming sausage'', and "streaming kink'' mode. The streaming tearing and sausage modes have the tearing mode-like structure with symmetric density fluctuation to the neutral sheet, and the streaming kink mode has the asymmetric fluctuation.　The growth rate of the streaming tearing mode decreases with increasing the magnetic Reynolds number, while those of the streaming　sausage and kink modes do not strongly depend on the Reynolds number. The wavelengths of these unstable modes are of the order of the thickness of plasma sheet, which behavior is almost same as the standard　tearing mode with no bulk flow. Roughly speaking the growth rates of　three modes become faster than the standard tearing mode. The situation of the plasma sheet with the bulk flow can be realized in the reconnection exhaust with the Alfvenic reconnection jet, and the unstable modes may be regarded as one of the generation processes of Alfvenic　turbulence in the plasma sheet during magnetic reconnection.

The different modes of hydro-economic analysis (Invited)

NASA Astrophysics Data System (ADS)

Harou, J. J.; Binions, O.; Erfani, T.

2013-12-01

In the face of growing water demands, climate change and spatial and temporal water access variability, accurately assessing the economic impacts of proposed water resource management changes is useful. The objective of this project funded by UK Water Industry Research was to present and demonstrate a framework for identifying and using the ';value of water' to enable water utilities and their regulators to make better decisions. A hydro-economic model can help evaluate water management options in terms of their hydrological and economic impact at different locations throughout a catchment over time. In this talk we discuss three modes in which hydro-economic models can be implemented: evaluative, behavioral and prescriptive. In evaluation mode economic water demand and benefit functions are used to post-process water resource management model results to assess the economic impacts (over space and time) of a policy under consideration. In behavioral hydro-economic models users are represented as agents and the economics is used to help predict their actions. In prescriptive mode optimization is used to find the most economically efficient management actions such as allocation patterns or source selection. These three types of hydro-economic analysis are demonstrated on a UK watershed (Great River Ouse) that includes 97 different water abstractors from amongst the public water supply, agriculture, industry and energy plant cooling sectors. The following issues under dry and normal historical conditions were investigated: Supply/demand investment planning, societal cost of environmental flows, water market prices, and scarcity-sensitive charges for water rights. The talk discusses which hydro-economic modeling mode is used to study each of these issues and why; example results are shown and discussed. The topic of how hydro-economic models can be built and deployed effectively is covered along with how existing water utility operational and planning tools can be converted into hydro-economic models.

Regional Climate Simulations of the Hydrological Cycle in the Iberian Peninsula with a Coupled WRF-HYDRO Model

NASA Astrophysics Data System (ADS)

Rios-Entenza, A.; Miguez-Macho, G.

2008-12-01

Land-atmosphere water exchanges and heat fluxes play an important role in climate and particularly in controlling precipitation in water-limited regions. One of such regions is the Iberian Peninsula, and in this study we examine the relevance of water recycling in convective precipitation regimes of the Fall and Spring there, when rainfall is critical for agriculture and many other human activities. We conducted simulations with WRF-ARW model at 5 km horizontal resolution, using a 1500 km x 1500 km nested grid that covers the Iberian Peninsula, with a parent domain that uses spectral nudging in order to avoid the distortion of the large-scale circulation caused by the interaction of the modeled flow with the lateral boundaries of the nested grid. For land-surface interactions we coupled WRF with the LEAF-HYDRO land surface model, which includes water table dynamics. We use therefore a tool that simulates the entire water cycle, including the water table, which has been reported to be critical for soil moisture dynamics in semi-arid regions like the Iberian Peninsula. For each one of the events that we selected, we performed two simulations: a control one, where all land-atmosphere feedbacks are taken into account, and the experiment, where infiltration of the precipitated water into the soil was suppressed. In this manner we explore the role of upward latent and sensible heat fluxes and evapotranspiration in precipitation dynamics. Preliminary results suggest that water recycling is a key factor in extending convective precipitation during several days, and that the total new water added in the area as a whole is only a fraction of the total measured rainfall. An estimation of this fraction is very important to better understanding the water budget and for hydrological planning in this water-stressed region.

Resolving the Multi-scale Behavior of Geochemical Weathering in the Critical Zone Using High Resolution Hydro-geochemical Models

NASA Astrophysics Data System (ADS)

Pandey, S.; Rajaram, H.

2015-12-01

This work investigates hydrologic and geochemical interactions in the Critical Zone (CZ) using high-resolution reactive transport modeling. Reactive transport models can be used to predict the response of geochemical weathering and solute fluxes in the CZ to changes in a dynamic environment, such as those pertaining to human activities and climate change in recent years. The scales of hydrology and geochemistry in the CZ range from days to eons in time and centimeters to kilometers in space. Here, we present results of a multi-dimensional, multi-scale hydro-geochemical model to investigate the role of subsurface heterogeneity on the formation of mineral weathering fronts in the CZ, which requires consideration of many of these spatio-temporal scales. The model is implemented using the reactive transport code PFLOTRAN, an open source subsurface flow and reactive transport code that utilizes parallelization over multiple processing nodes and provides a strong framework for simulating weathering in the CZ. The model is set up to simulate weathering dynamics in the mountainous catchments representative of the Colorado Front Range. Model parameters were constrained based on hydrologic, geochemical, and geophysical observations from the Boulder Creek Critical Zone Observatory (BcCZO). Simulations were performed in fractured rock systems and compared with systems of heterogeneous and homogeneous permeability fields. Tracer simulations revealed that the mean residence time of solutes was drastically accelerated as fracture density increased. In simulations that include mineral reactions, distinct signatures of transport limitations on weathering arose when discrete flow paths were included. This transport limitation was related to both advective and diffusive processes in the highly heterogeneous systems (i.e. fractured media and correlated random permeability fields with σlnk > 3). The well-known time-dependence of mineral weathering rates was found to be the most pronounced in the fractured systems, with a departure from the maximum system-averaged dissolution rate occurring after ~100 kyr followed by a gradual decrease in the reaction rate with time that persists beyond 104 kyr.

Hydrodynamic damping and stiffness prediction in Francis turbine runners using CFD

NASA Astrophysics Data System (ADS)

Nennemann, Bernd; Monette, Christine; Chamberland-Lauzon, Joël

2016-11-01

Fluid-structure interaction (FSI) has a major impact on the dynamic response of the structural components of hydroelectric turbines. On mid- to high-head Francis runners, the rotor-stator interaction (RSI) phenomenon has to be considered carefully during the design phase to avoid operational issues on the prototype machine. The RSI dynamic response amplitudes of the runner are driven by three main factors: (1) pressure forcing amplitudes, (2) excitation frequencies in relation to natural frequencies and (3) damping. All three of the above factors are significantly influenced by both mechanical and hydraulic parameters. The prediction of the first two factors has been largely documented in the literature. However, the prediction of hydro-dynamic damping has only recently and only partially been treated. Two mode-based approaches (modal work and coupled single degree of freedom) for the prediction of flow-added dynamic parameters using separate finite element analyses (FEA) in still water and unsteady computational fluid dynamic (CFD) analyses are presented. The modal motion is connected to the time resolved CFD calculation by means of dynamic mesh deformation. This approach has partially been presented in a previous paper applied to a simplified hydrofoil. The present work extends the approach to Francis runners under RSI loading. In particular the travelling wave mode shapes of turbine runners are considered. Reasonable agreement with experimental results is obtained in parts of the operating range.

Automated Calibration For Numerical Models Of Riverflow

NASA Astrophysics Data System (ADS)

Fernandez, Betsaida; Kopmann, Rebekka; Oladyshkin, Sergey

2017-04-01

Calibration of numerical models is fundamental since the beginning of all types of hydro system modeling, to approximate the parameters that can mimic the overall system behavior. Thus, an assessment of different deterministic and stochastic optimization methods is undertaken to compare their robustness, computational feasibility, and global search capacity. Also, the uncertainty of the most suitable methods is analyzed. These optimization methods minimize the objective function that comprises synthetic measurements and simulated data. Synthetic measurement data replace the observed data set to guarantee an existing parameter solution. The input data for the objective function derivate from a hydro-morphological dynamics numerical model which represents an 180-degree bend channel. The hydro- morphological numerical model shows a high level of ill-posedness in the mathematical problem. The minimization of the objective function by different candidate methods for optimization indicates a failure in some of the gradient-based methods as Newton Conjugated and BFGS. Others reveal partial convergence, such as Nelder-Mead, Polak und Ribieri, L-BFGS-B, Truncated Newton Conjugated, and Trust-Region Newton Conjugated Gradient. Further ones indicate parameter solutions that range outside the physical limits, such as Levenberg-Marquardt and LeastSquareRoot. Moreover, there is a significant computational demand for genetic optimization methods, such as Differential Evolution and Basin-Hopping, as well as for Brute Force methods. The Deterministic Sequential Least Square Programming and the scholastic Bayes Inference theory methods present the optimal optimization results. keywords: Automated calibration of hydro-morphological dynamic numerical model, Bayesian inference theory, deterministic optimization methods.

Relative Linkages of Chlorophyll-a with the Hydroclimatic and Biogeochemical Variables across the Continental U.S. (CONUS)

NASA Astrophysics Data System (ADS)

Ahmed, M. H.; Abdul-Aziz, O. I.

2017-12-01

Chlorophyll-a (Chl-a) is a key indicator for stream water quality and ecological health. The characterization of interplay between Chl-a and its numerous hydroclimatic and biogeochemical drivers is complex, and often involves multicollinear datasets. A systematic data analytics methodology was employed to determine the relative linkages of stream Chl-a with its dynamic environmental drivers at 50 stream water quality monitoring stations across the continental U.S. Multivariate statistical techniques of principal component analysis (PCA) and factor analysis (FA), in concert with Pearson correlation analysis, were applied to evaluate interrelationships among hydroclimatic, biogeochemical, and biological variables. Power-law based partial least square regression (PLSR) models were developed with a bootstrap Monte Carlo procedure (1000 iterations) to reliably estimate the comparative linkages of Chl-a by resolving multicollinearity in the data matrices (Nash-Sutcliff efficiency = 0.50-87). The data analytics suggested four environmental regimes of stream Chl-a, as dominated by nutrient, climate, redox, and hydro-atmospheric contributions, respectively. Total phosphorous (TP) was the most dominant driver of stream Chl-a in the nutrient controlled regime. Water temperature demonstrated the strongest control of Chl-a in the climate-dominated regime. Furthermore, pH and stream flow were found to be the most important drivers of Chl-a in the redox and hydro-atmospheric component dominated regimes, respectively. The research led to a significant reduction of dimensionality in the large data matrices, providing quantitative and qualitative insights on the dynamics of stream Chl-a. The findings would be useful to manage stream water quality and ecosystem health in the continental U.S. and around the world under a changing climate and environment.

Experimental modeling of swirl flows in power plants

NASA Astrophysics Data System (ADS)

Shtork, S. I.; Litvinov, I. V.; Gesheva, E. S.; Tsoy, M. A.; Skripkin, S. G.

2018-03-01

The article presents an overview of the methods and approaches to experimental modeling of various thermal and hydropower units - furnaces of pulverized coal boilers and flow-through elements of hydro turbines. The presented modeling approaches based on a combination of experimentation and rapid prototyping of working parts may be useful in optimizing energy equipment to improve safety and efficiency of industrial energy systems.

Density-velocity equations with bulk modulus for computational hydro-acoustics

NASA Astrophysics Data System (ADS)

Lin, Po-Hsien; Chen, Yung-Yu; John Yu, S.-T.

2014-02-01

This paper reports a new set of model equations for Computational Hydro Acoustics (CHA). The governing equations include the continuity and the momentum equations. The definition of bulk modulus is used to relate density with pressure. For 3D flow fields, there are four equations with density and velocity components as the unknowns. The inviscid equations are proved to be hyperbolic because an arbitrary linear combination of the three Jacobian matrices is diagonalizable and has a real spectrum. The left and right eigenvector matrices are explicitly derived. Moreover, an analytical form of the Riemann invariants are derived. The model equations are indeed suitable for modeling wave propagation in low-speed, nearly incompressible air and water flows. To demonstrate the capability of the new formulation, we use the CESE method to solve the 2D equations for aeolian tones generated by air flows passing a circular cylinder at Re = 89,000, 46,000, and 22,000. Numerical results compare well with previously published data. By simply changing the value of the bulk modulus, the same code is then used to calculate three cases of water flows passing a cylinder at Re = 89,000, 67,000, and 44,000.

Modeling the hydro-mechanical responses of strip and circular punch loadings on water-saturated collapsible geomaterials

DOE PAGES

Sun, WaiChing; Chen, Qiushi; Ostien, Jakob T.

2013-11-22

A stabilized enhanced strain finite element procedure for poromechanics is fully integrated with an elasto-plastic cap model to simulate the hydro-mechanical interactions of fluid-infiltrating porous rocks with associative and non-associative plastic flow. We present a quantitative analysis on how macroscopic plastic volumetric response caused by pore collapse and grain rearrangement affects the seepage of pore fluid, and vice versa. Results of finite element simulations imply that the dissipation of excess pore pressure may significantly affect the stress path and thus alter the volumetric plastic responses.

A 3D coupled hydro-mechanical granular model for the prediction of hot tearing formation

NASA Astrophysics Data System (ADS)

Sistaninia, M.; Phillion, A. B.; Drezet, J.-M.; Rappaz, M.

2012-07-01

A new 3D coupled hydro-mechanical granular model that simulates hot tearing formation in metallic alloys is presented. The hydro-mechanical model consists of four separate 3D modules. (I) The Solidification Module (SM) is used for generating the initial solid-liquid geometry. Based on a Voronoi tessellation of randomly distributed nucleation centers, this module computes solidification within each polyhedron using a finite element based solute diffusion calculation for each element within the tessellation. (II) The Fluid Flow Module (FFM) calculates the solidification shrinkage and deformation-induced pressure drop within the intergranular liquid. (III) The Semi-solid Deformation Module (SDM) is used to simulate deformation of the granular structure via a combined finite element / discrete element method. In this module, deformation of the solid grains is modeled using an elasto-viscoplastic constitutive law. (IV) The Failure Module (FM) is used to simulate crack initiation and propagation with the fracture criterion estimated from the overpressure required to overcome the capillary forces at the liquid-gas interface. The FFM, SDM, and FM are coupled processes since solid deformation, intergranular flow, and crack initiation are deeply linked together. The granular model predictions have been validated against bulk data measured experimentally and calculated with averaging techniques.

Experiments and Simulations of Fully Hydro-Mechanically Coupled Response of Rough Fractures Exposed to High-Pressure Fluid Injection

NASA Astrophysics Data System (ADS)

Vogler, D.; Settgast, R. R.; Annavarapu, C.; Madonna, C.; Bayer, P.; Amann, F.

2018-02-01

In this work, we present the application of a fully coupled hydro-mechanical method to investigate the effect of fracture heterogeneity on fluid flow through fractures at the laboratory scale. Experimental and numerical studies of fracture closure behavior in the presence of heterogeneous mechanical and hydraulic properties are presented. We compare the results of two sets of laboratory experiments on granodiorite specimens against numerical simulations in order to investigate the mechanical fracture closure and the hydro-mechanical effects, respectively. The model captures fracture closure behavior and predicts a nonlinear increase in fluid injection pressure with loading. Results from this study indicate that the heterogeneous aperture distributions measured for experiment specimens can be used as model input for a local cubic law model in a heterogeneous fracture to capture fracture closure behavior and corresponding fluid pressure response.

Development of an inflow controlled environmental flow regime for a Norwegian river

NASA Astrophysics Data System (ADS)

Alfredsen, Knut; Harby, Atle; Linnansaari, Tommi; Ugedal, Ola

2010-05-01

For most regulated rivers in Norway the common environmental flow regime is static and shows very little variation over the year. Recent research indicate that flow regimes that follow the natural inflow variation can meet the ecological and social demands for water in a better way. The implementation of a variable environmental flow regime provides many challenges both related to defining flow for various species and user groups in the river, but also due to practical implementation, legislation and control. A inflow controlled flow regime is developed for a Norwegian river regulated for hydro power as a pilot study. The regime should meet ecological demands from Atlantic salmon and brown trout, recreational use of water and visual impression of the river. This should be achieved preferably without altering the energy production in the hydro power system. The flow regime is developed for wet, dry and normal discharge conditions based on unregulated inflow to the catchment. The development of the seasonal flow requirements for various targets identified is done using a modification of the Building Block Method. Several options are tested regarding the integration of the flow regime into the operational strategy of the hydropower plant, both using real time prognosis of inflow and combinations with historical data. An important topic in selecting the release strategy is how it meets current Norwegian legislation and how well future documentation and environmental control can be carried out. An evaluation protocol is also proposed for the flow regime to test if the ecological targets are met.

Tree-, stand- and site-specific controls on landscape-scale patterns of transpiration

NASA Astrophysics Data System (ADS)

Hassler, Sibylle; Markus, Weiler; Theresa, Blume

2017-04-01

Transpiration is a key process in the hydrological cycle and a sound understanding and quantification of transpiration and its spatial variability is essential for management decisions as well as for improving the parameterisation of hydrological and soil-vegetation-atmosphere transfer models. For individual trees, transpiration is commonly estimated by measuring sap flow. Besides evaporative demand and water availability, tree-specific characteristics such as species, size or social status control sap flow amounts of individual trees. Within forest stands, properties such as species composition, basal area or stand density additionally affect sap flow, for example via competition mechanisms. Finally, sap flow patterns might also be influenced by landscape-scale characteristics such as geology, slope position or aspect because they affect water and energy availability; however, little is known about the dynamic interplay of these controls. We studied the relative importance of various tree-, stand- and site-specific characteristics with multiple linear regression models to explain the variability of sap velocity measurements in 61 beech and oak trees, located at 24 sites spread over a 290 km2-catchment in Luxembourg. For each of 132 consecutive days of the growing season of 2014 we modelled the daily sap velocities of these 61 trees and determined the importance of the different predictors. Results indicate that a combination of tree-, stand- and site-specific factors controls sap velocity patterns in the landscape, namely tree species, tree diameter, the stand density, geology and aspect. Compared to these predictors, spatial variability of atmospheric demand and soil moisture explains only a small fraction of the variability in the daily datasets. However, the temporal dynamics of the explanatory power of the tree-specific characteristics, especially species, are correlated to the temporal dynamics of potential evaporation. Thus, transpiration estimates at the landscape scale would benefit from not only considering hydro-meteorological drivers, but also including tree, stand and site characteristics in order to improve the spatial representation of transpiration for hydrological and soil-vegetation-atmosphere transfer models.

Torque characteristics of a 122-centimeter butterfly valve with a hydro/pneumatic actuator

NASA Technical Reports Server (NTRS)

Lin, F. N.; Moore, W. I.; Lundy, F. E.

1981-01-01

Actuating torque data from field testing of a 122-centimeter (48 in.) butterfly valve with a hydro/pneumatic actuator is presented. The hydraulic cylinder functions as either a forward or a reverse brake. Its resistance torque increases when the valve speeds up and decreases when the valve slows down. A reduction of flow resistance in the hydraulic flow path from one end of the hydraulic cylinder to the other will effectively reduce the hydraulic resistance torque and hence increase the actuating torque. The sum of hydrodynamic and friction torques (combined resistance torque) of a butterfly valve is a function of valve opening time. An increase in the pneumatic actuating pressure will result in a decrease in both the combined resistance torque and the actuator opening torque; however, it does shorten the valve opening time. As the pneumatic pressure increases, the valve opening time for a given configuration approaches an asymptotical value.

Aero-Hydroacoustics for Ships. Volume 2

DTIC Science & Technology

1984-06-01

Willmarth and Yang and Afzal and Narasimha. The subject of laminat turbulent transitional flows has beea examined by Yasuhara. 2 2 6 Currently there is no... composite structure of N ppanels of dimensions Li, L3 d thickness h subjected to boundary-layer flow. If we are interested in a hydro- oustic application...Reynolds number, in which case the wake vorticity will very likely be disordered. Laminat -flow airfoils’ (or, say, for 6"Reynolds numbers less than 1

Investigation of distributor vane jets to decrease the unsteady load on hydro turbine runner blades

NASA Astrophysics Data System (ADS)

Lewis, B. J.; Cimbala, J. M.; Wouden, A. M.

2012-11-01

As the runner blades of a Francis hydroturbine pass though the wakes created from the wicket gates, they experience a significant change in absolute velocity, flow angle, and pressure. The concept of adding jets to the trailing edge of the wicket gates is proposed as a method for reducing the dynamic load on the hydroturbine runner blades. Computational experiments show a decrease in velocity variation experienced by the runner blade with the addition of the jets. The decrease in velocity variation resulted in a 43% decrease in global torque variation at the runner passing frequency. However, an increased variation was observed at the wicket gate passing frequency. Also, a 5.7% increase in average global torque was observed with the addition of blowing from the trailing-edge of the wicket gates.

Response of the groundwater system in the Guanzhong Basin (central China) to climate change and human activities

NASA Astrophysics Data System (ADS)

Wang, Wenke; Zhang, Zaiyong; Duan, Lei; Wang, Zhoufeng; Zhao, Yaqian; Zhang, Qian; Dai, Meiling; Liu, Huizhong; Zheng, Xiaoyan; Sun, Yibo

2018-03-01

The Guanzhong Basin in central China features a booming economy and has suffered severe drought, resulting in serious groundwater depletion in the last 30 years. As a major water resource, groundwater plays a significant role in water supply. The combined impact of climate change and intensive human activities has caused a substantial decline in groundwater recharge and groundwater levels, as well as degradation of groundwater quality and associated changes in the ecosystems. Based on observational data, an integrated approach was used to assess the impact of climate change and human activities on the groundwater system and the base flow of the river basin. Methods included: river runoff records and a multivariate statistical analysis of data including historical groundwater levels and climate; hydro-chemical investigation and trend analysis of the historical hydro-chemical data; wavelet analysis of climate data; and the base flow index. The analyses indicate a clear warming trend and a decreasing trend in rainfall since the 1960s, in addition to increased human activities since the 1970s. The reduction of groundwater recharge in the past 30 years has led to a continuous depletion of groundwater levels, complex changes of the hydro-chemical environment, localized salinization, and a strong decline of the base flow to the river. It is expected that the results will contribute to a more comprehensive management plan for groundwater and the related eco-environment in the face of growing pressures from intensive human activities superimposed on climate change in this region.

Incorporating human-water dynamics in a hyper-resolution land surface model

NASA Astrophysics Data System (ADS)

Vergopolan, N.; Chaney, N.; Wanders, N.; Sheffield, J.; Wood, E. F.

2017-12-01

The increasing demand for water, energy, and food is leading to unsustainable groundwater and surface water exploitation. As a result, the human interactions with the environment, through alteration of land and water resources dynamics, need to be reflected in hydrologic and land surface models (LSMs). Advancements in representing human-water dynamics still leave challenges related to the lack of water use data, water allocation algorithms, and modeling scales. This leads to an over-simplistic representation of human water use in large-scale models; this is in turn leads to an inability to capture extreme events signatures and to provide reliable information at stakeholder-level spatial scales. The emergence of hyper-resolution models allows one to address these challenges by simulating the hydrological processes and interactions with the human impacts at field scales. We integrated human-water dynamics into HydroBlocks - a hyper-resolution, field-scale resolving LSM. HydroBlocks explicitly solves the field-scale spatial heterogeneity of land surface processes through interacting hydrologic response units (HRUs); and its HRU-based model parallelization allows computationally efficient long-term simulations as well as ensemble predictions. The implemented human-water dynamics include groundwater and surface water abstraction to meet agricultural, domestic and industrial water demands. Furthermore, a supply-demand water allocation scheme based on relative costs helps to determine sectoral water use requirements and tradeoffs. A set of HydroBlocks simulations over the Midwest United States (daily, at 30-m spatial resolution for 30 years) are used to quantify the irrigation impacts on water availability. The model captures large reductions in total soil moisture and water table levels, as well as spatiotemporal changes in evapotranspiration and runoff peaks, with their intensity related to the adopted water management strategy. By incorporating human-water dynamics in a hyper-resolution LSM this work allows for progress on hydrological monitoring and predictions, as well as drought preparedness and water impact assessments at relevant decision-making scales.

Dynamic Collaboration Infrastructure for Hydrologic Science

NASA Astrophysics Data System (ADS)

Tarboton, D. G.; Idaszak, R.; Castillo, C.; Yi, H.; Jiang, F.; Jones, N.; Goodall, J. L.

2016-12-01

Data and modeling infrastructure is becoming increasingly accessible to water scientists. HydroShare is a collaborative environment that currently offers water scientists the ability to access modeling and data infrastructure in support of data intensive modeling and analysis. It supports the sharing of and collaboration around "resources" which are social objects defined to include both data and models in a structured standardized format. Users collaborate around these objects via comments, ratings, and groups. HydroShare also supports web services and cloud based computation for the execution of hydrologic models and analysis and visualization of hydrologic data. However, the quantity and variety of data and modeling infrastructure available that can be accessed from environments like HydroShare is increasing. Storage infrastructure can range from one's local PC to campus or organizational storage to storage in the cloud. Modeling or computing infrastructure can range from one's desktop to departmental clusters to national HPC resources to grid and cloud computing resources. How does one orchestrate this vast number of data and computing infrastructure without needing to correspondingly learn each new system? A common limitation across these systems is the lack of efficient integration between data transport mechanisms and the corresponding high-level services to support large distributed data and compute operations. A scientist running a hydrology model from their desktop may require processing a large collection of files across the aforementioned storage and compute resources and various national databases. To address these community challenges a proof-of-concept prototype was created integrating HydroShare with RADII (Resource Aware Data-centric collaboration Infrastructure) to provide software infrastructure to enable the comprehensive and rapid dynamic deployment of what we refer to as "collaborative infrastructure." In this presentation we discuss the results of this proof-of-concept prototype which enabled HydroShare users to readily instantiate virtual infrastructure marshaling arbitrary combinations, varieties, and quantities of distributed data and computing infrastructure in addressing big problems in hydrology.

A hydro-meteorological model chain to assess the influence of natural variability and impacts of climate change on extreme events and propose optimal water management

NASA Astrophysics Data System (ADS)

von Trentini, F.; Willkofer, F.; Wood, R. R.; Schmid, F. J.; Ludwig, R.

2017-12-01

The ClimEx project (Climate change and hydrological extreme events - risks and perspectives for water management in Bavaria and Québec) focuses on the effects of climate change on hydro-meteorological extreme events and their implications for water management in Bavaria and Québec. Therefore, a hydro-meteorological model chain is applied. It employs high performance computing capacity of the Leibniz Supercomputing Centre facility SuperMUC to dynamically downscale 50 members of the Global Circulation Model CanESM2 over European and Eastern North American domains using the Canadian Regional Climate Model (RCM) CRCM5. Over Europe, the unique single model ensemble is conjointly analyzed with the latest information provided through the CORDEX-initiative, to better assess the influence of natural climate variability and climatic change in the dynamics of extreme events. Furthermore, these 50 members of a single RCM will enhance extreme value statistics (extreme return periods) by exploiting the available 1500 model years for the reference period from 1981 to 2010. Hence, the RCM output is applied to drive the process based, fully distributed, and deterministic hydrological model WaSiM in high temporal (3h) and spatial (500m) resolution. WaSiM and the large ensemble are further used to derive a variety of hydro-meteorological patterns leading to severe flood events. A tool for virtual perfect prediction shall provide a combination of optimal lead time and management strategy to mitigate certain flood events following these patterns.

Efficient and accurate numerical schemes for a hydro-dynamically coupled phase field diblock copolymer model

NASA Astrophysics Data System (ADS)

Cheng, Qing; Yang, Xiaofeng; Shen, Jie

2017-07-01

In this paper, we consider numerical approximations of a hydro-dynamically coupled phase field diblock copolymer model, in which the free energy contains a kinetic potential, a gradient entropy, a Ginzburg-Landau double well potential, and a long range nonlocal type potential. We develop a set of second order time marching schemes for this system using the "Invariant Energy Quadratization" approach for the double well potential, the projection method for the Navier-Stokes equation, and a subtle implicit-explicit treatment for the stress and convective term. The resulting schemes are linear and lead to symmetric positive definite systems at each time step, thus they can be efficiently solved. We further prove that these schemes are unconditionally energy stable. Various numerical experiments are performed to validate the accuracy and energy stability of the proposed schemes.

Instability behaviour of cosmic gravito-coupled correlative complex bi-fluidic admixture

NASA Astrophysics Data System (ADS)

Das, Papari; Karmakar, Pralay Kumar

2017-10-01

The gravitational instability of an unbounded infinitely extended composite gravitating cloud system composed of gravito-coupled neutral gaseous fluid (NGF) and dark matter fluid (DMF) is theoretically investigated in a classical framework. It is based on a spatially-flat geometry approximation (1D, sheet-like, boundless) at the backdrop that the radius of curvature of the gravito-confined bi-fluidic-boundary is much larger than all the hydro-characteristic scale lengths of interest. The relevant collective correlative dynamics, via the lowest-order mnemonic viscoelasticity, is mooted. We apply a standard formalism of normal mode analysis to yield a unique brand of generalized quadratic dispersion relation having variable multi-parametric coefficients dependent on the diversified equilibrium properties. It is parametrically seen that the DMF flow speed and the DMF viscoelasticity introduce stabilizing effects against the composite cloud collapse. The instability physiognomies, as specialized extreme corollaries, are in good accord with the previously reported predictions. The analysis may be widely useful to see the gravito-thermally coupled wave dynamics leading to the formation of large-scale hierarchical non-homologous structures in dark-matter-dominated dwarf galaxies.

Toward a hydro-political water cycle: virtual water,hydrology and international political economy

NASA Astrophysics Data System (ADS)

Greco, Francesca

2014-05-01

At the light of global food trade, no water cycle can be considered "closed" under a political point of view. While the hydrological cycle is a circular closed environment, if we open up our perspectives to social sciences, we will demonstrate how, thanks to virtual water, it is today possible to elaborate how much water 'enters or leave' any water body under the form crop-export, in terms of " water used for the production of agri-food products'. This new 'hydro-political cycle' will be discussed at the light of different theoretical perspectives: food trade theories, hydrology, international water law, socio-economic metabolism, material flow analysis.

Suspended Sediment Dynamics in the Macrotidal Seine Estuary (France): 2. Numerical Modeling of Sediment Fluxes and Budgets Under Typical Hydrological and Meteorological Conditions

NASA Astrophysics Data System (ADS)

Schulz, E.; Grasso, F.; Le Hir, P.; Verney, R.; Thouvenin, B.

2018-01-01

Understanding the sediment dynamics in an estuary is important for its morphodynamic and ecological assessment as well as, in case of an anthropogenically controlled system, for its maintenance. However, the quantification of sediment fluxes and budgets is extremely difficult from in-situ data and requires thoroughly validated numerical models. In the study presented here, sediment fluxes and budgets in the lower Seine Estuary were quantified and investigated from seasonal to annual time scales with respect to realistic hydro- and meteorological conditions. A realistic three-dimensional process-based hydro- and sediment-dynamic model was used to quantify mud and sand fluxes through characteristic estuarine cross-sections. In addition to a reference experiment with typical forcing, three experiments were carried out and analyzed, each differing from the reference experiment in either river discharge or wind and waves so that the effects of these forcings could be separated. Hydro- and meteorological conditions affect the sediment fluxes and budgets in different ways and at different locations. Single storm events induce strong erosion in the lower estuary and can have a significant effect on the sediment fluxes offshore of the Seine Estuary mouth, with the flux direction depending on the wind direction. Spring tides cause significant up-estuary fluxes at the mouth. A high river discharge drives barotropic down-estuary fluxes at the upper cross-sections, but baroclinic up-estuary fluxes at the mouth and offshore so that the lower estuary gains sediment during wet years. This behavior is likely to be observed worldwide in estuaries affected by density gradients and turbidity maximum dynamics.

Impact of landuse/land cover change on run-off in the catchment of a hydro power project

NASA Astrophysics Data System (ADS)

Khare, Deepak; Patra, Diptendu; Mondal, Arun; Kundu, Sananda

2017-05-01

The landuse/land cover change and rainfall have a significant influence on the hydrological response of the river basins. The run-off characteristics are changing naturally due to reduction of initial abstraction that increases the run-off volume. Therefore, it is necessary to quantify the changes in the run-off characteristics of a catchment under the influence of changed landuse/land cover. Soil conservation service model has been used in the present study to analyse the impact of various landuse/land cover (past, present and future time period) change in the run-off characteristics of a part of Narmada basin at the gauge discharge site of Mandaleswar in Madhya Pradesh, India. Calculated run-off has been compared with the observed run-off data for the study. The landuse/land cover maps of 1990, 2000 and 2009 have been prepared by digital classification method with proper accuracy using satellite imageries. The impact of the run-off change on hydro power potential has been assessed in the study along with the estimation of the future changes in hydro power potential. Five types of conditions (+10, +5 %, average, -5, -10 % of average rainfall) have been applied with 90 and 75 % dependability status. The generated energy will be less in 90 % dependable flow in respect to the 75 % dependable flow. This work will be helpful for future planning related to establishment of hydropower setup.

Study of the use of a micro hydro in knockdown container completed with a cylindrical form housing of francis hydraulic turbine to support the development program of energy self-sustainability for remote and isolated areas in Indonesia

NASA Astrophysics Data System (ADS)

Kamal, Samsul; Prajitno; Pardadi, Janu

2017-11-01

With an intention to reduce the consumption of energy from fossil fuels and the CO2 emission in relation with the climate change solution, Indonesian Government has targeted that the role of the New and Renewable Energy (NRE) resources reaches at least 23% , or about 27 GW , in 2025 and it is expected to increase to the extent of about 134 GW in 2050 within the scenario of mixed energy supply. Geographically Indonesia has many remote and isolated areas with lack of appropriate infrastructure supports. But in the most of the areas, huge potential of new and renewable energy are available such as hydro energy is about 75 GW, biomass energy is about 32 GW and bio fuel is about 32 GW. The total utilization of the energy from small hydro energy up to this year for example is only about 300 MW. The significant obstacle in optimizing the utilization of small hydro energy in the areas is mainly on the infrastructure conditions and the local manufacture capabilities. Difficulties in mobilization of experts, skill worker , parts and constructions material result in very time consuming and costly for site construction. In this research a hydro turbine built in knock down container completed with a Francis turbine in cylindrical form housing is proposed and reported its performance on implementation. The hydro in a knock down container concept comes from the idea to manufacture hydro power solutions in a knock down container, readymade to be transported to installation sites. It can be easily manufactured in a quality controlled and cost effective environment, transported and installed in remote areas, to operate and maintain with minimal amount of equipment. It shows that the implementation of the unit in a remote area has reduced the total site construction time by 1/3 compared to the predicted one with conventional unit. The performance of the Francis turbine with cylindrical form housing has shown comparable with the conventional one which has volute form housing. The superiority was even more pronounced by introducing a deflection insert in its input flow channel. The insertion was capable to create more distributed flow into the runner. Efficiency of the turbine up to 80% was performed in this research. Local manufacture for turbine usually use many craft work and welding to built a volute form housing for the Francis turbine. The cylindrical form housing here has also proven significantly in reducing the time and price for the turbine manufacturing process.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutierrez, Marte

Colorado School of Mines conducted research and training in the development and validation of an advanced CO{sub 2} GS (Geological Sequestration) probabilistic simulation and risk assessment model. CO{sub 2} GS simulation and risk assessment is used to develop advanced numerical simulation models of the subsurface to forecast CO2 behavior and transport; optimize site operational practices; ensure site safety; and refine site monitoring, verification, and accounting efforts. As simulation models are refined with new data, the uncertainty surrounding the identified risks decrease, thereby providing more accurate risk assessment. The models considered the full coupling of multiple physical processes (geomechanical and fluidmore » flow) and describe the effects of stochastic hydro-mechanical (H-M) parameters on the modeling of CO{sub 2} flow and transport in fractured porous rocks. Graduate students were involved in the development and validation of the model that can be used to predict the fate, movement, and storage of CO{sub 2} in subsurface formations, and to evaluate the risk of potential leakage to the atmosphere and underground aquifers. The main major contributions from the project include the development of: 1) an improved procedure to rigorously couple the simulations of hydro-thermomechanical (H-M) processes involved in CO{sub 2} GS; 2) models for the hydro-mechanical behavior of fractured porous rocks with random fracture patterns; and 3) probabilistic methods to account for the effects of stochastic fluid flow and geomechanical properties on flow, transport, storage and leakage associated with CO{sub 2} GS. The research project provided the means to educate and train graduate students in the science and technology of CO{sub 2} GS, with a focus on geologic storage. Specifically, the training included the investigation of an advanced CO{sub 2} GS simulation and risk assessment model that can be used to predict the fate, movement, and storage of CO{sub 2} in underground formations, and the evaluation of the risk of potential CO{sub 2} leakage to the atmosphere and underground aquifers.« less

The Comparison of Point Data Models for the Output of WRF Hydro Model in the IDV

NASA Astrophysics Data System (ADS)

Ho, Y.; Weber, J.

2017-12-01

WRF Hydro netCDF output files contain streamflow, flow depth, longitude, latitude, altitude and stream order values for each forecast point. However, the data are not CF compliant. The total number of forecast points for the US CONUS is approximately 2.7 million and it is a big challenge for any visualization and analysis tool. The IDV point cloud display shows point data as a set of points colored by parameter. This display is very efficient compared to a standard point type display for rendering a large number of points. The one problem we have is that the data I/O can be a bottleneck issue when dealing with a large collection of point input files. In this presentation, we will experiment with different point data models and their APIs to access the same WRF Hydro model output. The results will help us construct a CF compliant netCDF point data format for the community.

Modeling spatiotemporal dynamics of global wetlands: comprehensive evaluation of a new sub-grid TOPMODEL parameterization and uncertainties

NASA Astrophysics Data System (ADS)

Zhang, Zhen; Zimmermann, Niklaus E.; Kaplan, Jed O.; Poulter, Benjamin

2016-03-01

Simulations of the spatiotemporal dynamics of wetlands are key to understanding the role of wetland biogeochemistry under past and future climate. Hydrologic inundation models, such as the TOPography-based hydrological model (TOPMODEL), are based on a fundamental parameter known as the compound topographic index (CTI) and offer a computationally cost-efficient approach to simulate wetland dynamics at global scales. However, there remains a large discrepancy in the implementations of TOPMODEL in land-surface models (LSMs) and thus their performance against observations. This study describes new improvements to TOPMODEL implementation and estimates of global wetland dynamics using the LPJ-wsl (Lund-Potsdam-Jena Wald Schnee und Landschaft version) Dynamic Global Vegetation Model (DGVM) and quantifies uncertainties by comparing three digital elevation model (DEM) products (HYDRO1k, GMTED, and HydroSHEDS) at different spatial resolution and accuracy on simulated inundation dynamics. In addition, we found that calibrating TOPMODEL with a benchmark wetland data set can help to successfully delineate the seasonal and interannual variation of wetlands, as well as improve the spatial distribution of wetlands to be consistent with inventories. The HydroSHEDS DEM, using a river-basin scheme for aggregating the CTI, shows the best accuracy for capturing the spatiotemporal dynamics of wetlands among the three DEM products. The estimate of global wetland potential/maximum is ˜ 10.3 Mkm2 (106 km2), with a mean annual maximum of ˜ 5.17 Mkm2 for 1980-2010. When integrated with wetland methane emission submodule, the uncertainty of global annual CH4 emissions from topography inputs is estimated to be 29.0 Tg yr-1. This study demonstrates the feasibility of TOPMODEL to capture spatial heterogeneity of inundation at a large scale and highlights the significance of correcting maximum wetland extent to improve modeling of interannual variations in wetland area. It additionally highlights the importance of an adequate investigation of topographic indices for simulating global wetlands and shows the opportunity to converge wetland estimates across LSMs by identifying the uncertainty associated with existing wetland products.

Validation of Hydrodynamic Load Models Using CFD for the OC4-DeepCwind Semisubmersible: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benitz, M. A.; Schmidt, D. P.; Lackner, M. A.

Computational fluid dynamics (CFD) simulations were carried out on the OC4-DeepCwind semi-submersible to obtain a better understanding of how to set hydrodynamic coefficients for the structure when using an engineering tool such as FAST to model the system. The focus here was on the drag behavior and the effects of the free-surface, free-ends and multi-member arrangement of the semi-submersible structure. These effects are investigated through code-to-code comparisons and flow visualizations. The implications on mean load predictions from engineering tools are addressed. The work presented here suggests that selection of drag coefficients should take into consideration a variety of geometric factors.more » Furthermore, CFD simulations demonstrate large time-varying loads due to vortex shedding, which FAST's hydrodynamic module, HydroDyn, does not model. The implications of these oscillatory loads on the fatigue life needs to be addressed.« less

Anisotropic nonequilibrium hydrodynamic attractor

NASA Astrophysics Data System (ADS)

Strickland, Michael; Noronha, Jorge; Denicol, Gabriel S.

2018-02-01

We determine the dynamical attractors associated with anisotropic hydrodynamics (aHydro) and the DNMR equations for a 0 +1 d conformal system using kinetic theory in the relaxation time approximation. We compare our results to the nonequilibrium attractor obtained from the exact solution of the 0 +1 d conformal Boltzmann equation, the Navier-Stokes theory, and the second-order Mueller-Israel-Stewart theory. We demonstrate that the aHydro attractor equation resums an infinite number of terms in the inverse Reynolds number. The resulting resummed aHydro attractor possesses a positive longitudinal-to-transverse pressure ratio and is virtually indistinguishable from the exact attractor. This suggests that an optimized hydrodynamic treatment of kinetic theory involves a resummation not only in gradients (Knudsen number) but also in the inverse Reynolds number. We also demonstrate that the DNMR result provides a better approximation of the exact kinetic theory attractor than the Mueller-Israel-Stewart theory. Finally, we introduce a new method for obtaining approximate aHydro equations which relies solely on an expansion in the inverse Reynolds number. We then carry this expansion out to the third order, and compare these third-order results to the exact kinetic theory solution.

The application of Biological-Hydraulic coupled model for Tubificidae-microorganism interaction system

NASA Astrophysics Data System (ADS)

Zhong, Xiao; Sun, Peide; Song, Yingqi; Wang, Ruyi; Fang, Zhiguo

2010-11-01

Based on the fully coupled activated sludge model (FCASM), the novel model Tubificidae -Fully Coupled Activated Sludge Model-hydraulic (T-FCASM-Hydro), has been developed in our previous work. T-FCASM-Hydro not only describe the interactive system between Tubificidae and functional microorganisms for the sludge reduction and nutrient removal simultaneously, but also considere the interaction between biological and hydraulic field, After calibration and validation of T-FCASM-Hydro at Zhuji Feida-hongyu Wastewater treatment plant (WWTP) in Zhejiang province, T-FCASM-Hydro was applied for determining optimal operating condition in the WWTP. Simulation results showed that nitrogen and phosphorus could be removed efficiently, and the efficiency of NH4+-N removal enhanced with increase of DO concentration. At a certain low level of DO concentration in the aerobic stage, shortcut nitrification-denitrification dominated in the process of denitrification in the novel system. However, overhigh agitation (>6 mgṡL-1) could result in the unfavorable feeding behavior of Tubificidae because of the strong flow disturbance, which might lead to low rate of sludge reduction. High sludge reduction rate and high removal rate of nitrogen and phosphorus could be obtained in the new-style oxidation ditch when DO concentration at the aerobic stage with Tubificidae was maintained at 3.6 gṡm-3.

An experimental study of dependence of hydro turbine vibration parameters on pressure pulsations in the flow path

NASA Astrophysics Data System (ADS)

Dekterev, D.; Maslennikova, A.; Abramov, A.

2017-09-01

The operation modes of the hydraulic power plant water turbine with the formation of a precessing vortex core were studied on the hydrodynamic set-up with the model of hydraulic unit. The dependence of low-frequency vibrations on flow pressure pulsations in the hydraulic unit was established. The results of the air injection effect on the vibrational parameters of the hydrodynamic set-up were presented.

Tree-, stand- and site-specific controls on landscape-scale patterns of transpiration

NASA Astrophysics Data System (ADS)

Kathrin Hassler, Sibylle; Weiler, Markus; Blume, Theresa

2018-01-01

Transpiration is a key process in the hydrological cycle, and a sound understanding and quantification of transpiration and its spatial variability is essential for management decisions as well as for improving the parameterisation and evaluation of hydrological and soil-vegetation-atmosphere transfer models. For individual trees, transpiration is commonly estimated by measuring sap flow. Besides evaporative demand and water availability, tree-specific characteristics such as species, size or social status control sap flow amounts of individual trees. Within forest stands, properties such as species composition, basal area or stand density additionally affect sap flow, for example via competition mechanisms. Finally, sap flow patterns might also be influenced by landscape-scale characteristics such as geology and soils, slope position or aspect because they affect water and energy availability; however, little is known about the dynamic interplay of these controls.We studied the relative importance of various tree-, stand- and site-specific characteristics with multiple linear regression models to explain the variability of sap velocity measurements in 61 beech and oak trees, located at 24 sites across a 290 km2 catchment in Luxembourg. For each of 132 consecutive days of the growing season of 2014 we modelled the daily sap velocity and derived sap flow patterns of these 61 trees, and we determined the importance of the different controls.Results indicate that a combination of mainly tree- and site-specific factors controls sap velocity patterns in the landscape, namely tree species, tree diameter, geology and aspect. For sap flow we included only the stand- and site-specific predictors in the models to ensure variable independence. Of those, geology and aspect were most important. Compared to these predictors, spatial variability of atmospheric demand and soil moisture explains only a small fraction of the variability in the daily datasets. However, the temporal dynamics of the explanatory power of the tree-specific characteristics, especially species, are correlated to the temporal dynamics of potential evaporation. We conclude that transpiration estimates on the landscape scale would benefit from not only consideration of hydro-meteorological drivers, but also tree, stand and site characteristics in order to improve the spatial and temporal representation of transpiration for hydrological and soil-vegetation-atmosphere transfer models.

The development of biodiversity conservation measures in China's hydro projects: A review.

PubMed

Bai, Ruiqiao; Liu, Xuehua; Liu, Xiaofei; Liu, Lanmei; Wang, Jianping; Liao, Sihui; Zhu, Annah; Li, Zhouyuan

2017-11-01

The hydropower capacity of China ranks first in the world and accounts for approximately 20% of the total energy production in the country. While hydropower has substantially contributed to meeting China's renewable energy targets and providing clean energy to rural areas, the development of hydropower in China has been met with significant controversy. Ecologically, hydro projects alter the landscape, with potential impacts to the country's aquatic biodiversity. Over the past four decades in China, various mainstream opinions and misunderstandings have been presented concerning how to alleviate the negative impacts of hydro projects on aquatic ecosystems. This article reviews research concerning potential mitigation measures to enhance aquatic biodiversity conservation in hydro projects in China. Based on the academic attention such research has attracted, three technical measures for aquatic biodiversity conservation are considered: (1) fish passages, (2) restocking efforts and (3) river and lake renovations. This article provides a historical comparison of these three practices in China to demonstrate the advantages and disadvantages of each method. The article also reviews the relevant legislation, regulations and technical guidelines concerning China's hydro projects dating back to 1979. The dynamics in research, publications, and patents concerning these three mitigation measures are summarized to demonstrate their technological developments in the context of legislative and policy advances. Data were gathered through the China Knowledge Resource Integrated Database and the State Intellectual Property Office of the People's Republic of China. Based on the analysis provided, the article recommends an expansion of China's environmental certification system for hydro projects, more robust regional legislation to bolster the national framework, the cooperation between upstream and downstream conservation mechanisms, and better monitoring to determine the efficacy of mitigation measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Static and dynamic stress analyses of the prototype high head Francis runner based on site measurement

NASA Astrophysics Data System (ADS)

Huang, X.; Oram, C.; Sick, M.

2014-03-01

More efforts are put on hydro-power to balance voltage and frequency within seconds for primary control in modern smart grids. This requires hydraulic turbines to run at off-design conditions. especially at low load or speed-no load. Besides. the tendency of increasing power output and decreasing weight of the turbine runners has also led to the high level vibration problem of the runners. especially high head Francis runners. Therefore. it is important to carry out the static and dynamic stress analyses of prototype high head Francis runners. This paper investigates the static and dynamic stresses on the prototype high head Francis runner based on site measurements and numerical simulations. The site measurements are performed with pressure transducers and strain gauges. Based on the measured results. computational fluid dynamics (CFD) simulations for the flow channel from stay vane to draft tube cone are performed. Static pressure distributions and dynamic pressure pulsations caused by rotor-stator interaction (RSI) are obtained under various operating conditions. With the CFD results. static and dynamic stresses on the runner at different operating points are calculated by means of the finite element method (FEM). The agreement between simulation and measurement is analysed with linear regression method. which indicates that the numerical result agrees well with that of measurement. Furthermore. the maximum static and dynamic stresses on the runner blade are obtained at various operating points. The relations of the maximum stresses and the power output are discussed in detail. The influences of the boundary conditions on the structural behaviour of the runner are also discussed.

Impact of coastal forcing and groundwater recharge on the growth of a fresh groundwater lens in a mega-scale beach nourishment

NASA Astrophysics Data System (ADS)

Huizer, Sebastian; Radermacher, Max; de Vries, Sierd; Oude Essink, Gualbert H. P.; Bierkens, Marc F. P.

2018-02-01

For a large beach nourishment called the Sand Engine - constructed in 2011 at the Dutch coast - we have examined the impact of coastal forcing (i.e. natural processes that drive coastal hydro- and morphodynamics) and groundwater recharge on the growth of a fresh groundwater lens between 2011 and 2016. Measurements of the morphological change and the tidal dynamics at the study site were incorporated in a calibrated three-dimensional and variable-density groundwater model of the study area. Simulations with this model showed that the detailed incorporation of both the local hydro- and morphodynamics and the actual recharge rate can result in a reliable reconstruction of the growth in fresh groundwater resources. In contrast, the neglect of tidal dynamics, land-surface inundations, and morphological changes in model simulations can result in considerable overestimations of the volume of fresh groundwater. In particular, wave runup and coinciding coastal erosion during storm surges limit the growth in fresh groundwater resources in dynamic coastal environments, and should be considered at potential nourishment sites to delineate the area that is vulnerable to salinization.

Controls on Water Storage, Mixing and Release in a Nested Catchment Set-up with Clean and Mixed Physiographic Characteristics

NASA Astrophysics Data System (ADS)

Pfister, L.; McDonnell, J.; Hissler, C.; Martínez-Carreras, N.; Klaus, J.

2015-12-01

With catchment water storage being only rarely determined, storage dynamics remain largely unknown to date. However, storage bears considerable potential for catchment inter-comparison exercises, as well as it is likely to have an important role in regulating catchment functions. Catchment comparisons across a wide range of environments and scales will help to increase our understanding of relationships between storage dynamics and catchment processes. With respect to the potential of catchment storage for bringing new momentum to catchment classification and catchment processes understanding we currently investigate spatial and temporal variability of dynamic storage in a nested catchment set-up (16 catchments) of the Alzette River basin (Luxembourg, Europe), covering a wide range of geological settings, catchment areas, contrasted landuse, and hydro-meteorological and tracer series. We define catchment storage as the total amount of water stored in a control volume, delimited by the catchment's topographical boundaries and depth of saturated and unsaturated zones. Complementary storage assessments (via input-output dynamics of natural tracers, geographical sounding, groundwater level measurements, soil moisture measurements, hydrometry) are carried out for comparison purposes. In our nested catchment set-up we have (1) assessed dependencies between geology, catchment permeability and winter runoff coefficients, (2) calculated water balance derived catchment storage and mixing potential and quantified how dynamic storage differs between catchments and scales, and (3) examined how stream baseflow dD (as a proxy for baseflow transit time) and integrated flow measures (like the flow duration curve) relate to bedrock geology. Catchments with higher bedrock permeability exhibited larger storage capacities and eventually lower average winter runoff coefficients. Over a time-span of 11 years, all catchments re-produced the same winter runoff coefficients year after year, regardless of their bedrock geology, permeability and winter season storage filling ratios. Ultimately, catchment organisation in our area of interest (i.e. geology, permeability, flowpath length) appeared to have a strong control on winter runoff coefficients, catchment storage and subsequently baseflow dD.

75 FR 11153 - Free Flow Power Qualified Hydro 22, LLC; Notice of Preliminary Permit Application Accepted for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-10

... water surface elevation of 609 feet mean sea level; (3) an new 54-foot-long by 74-foot-wide powerhouse to contain two new turbine- generator units for a total installed capacity of 5.0 megawatts; (4) a...

Emergent Archetype Hydrological-Biogeochemical Response Patterns in Heterogeneous Catchments

NASA Astrophysics Data System (ADS)

Jawitz, J. W.; Gall, H. E.; Rao, P.

2013-12-01

What can spatiotemporally integrated patterns observed in stream hydrologic and biogeochemical signals generated in response to transient hydro-climatic and anthropogenic forcing tell us about the interactions between spatially heterogeneous soil-mediated hydrological and biogeochemical processes? We seek to understand how the spatial structure of solute sources coupled with hydrologic responses affect observed concentration-discharge (C-Q) patterns. These patterns are expressions of the spatiotemporal structure of solute loads exported from managed catchments, and their likely ecological consequences manifested in receiving water bodies (e.g., wetlands, rivers, lakes, and coastal waters). We investigated the following broad questions: (1) How does the correlation between flow-generating areas and biogeochemical source areas across a catchment evolve under stochastic hydro-climatic forcing? (2) What are the feasible hydrologic and biogeochemical responses that lead to the emergence of the observed archetype C-Q patterns? and; (3) What implications do these coupled dynamics have for catchment monitoring and implementation of management practices? We categorize the observed temporal signals into three archetypical C-Q patterns: dilution; accretion, and constant concentration. We introduce a parsimonious stochastic model of heterogeneous catchments, which act as hydrologic and biogeochemical filters, to examine the relationship between spatial heterogeneity and temporal history of solute export signals. The core concept of the modeling framework is considering the types and degree of spatial correlation between solute source zones and flow generating zones, and activation of different portions of the catchments during rainfall events. Our overarching hypothesis is that each of the archetype C-Q patterns can be generated by explicitly linking landscape-scale hydrologic responses and spatial distributions of solute source properties within a catchment. The model simulations reproduce the three major C-Q patterns observed in published data, offering valuable insight into coupled catchment processes. The findings have important implications for effective catchment management for water quality improvement, and stream monitoring strategies.

Modes, hydrodynamic processes and ecological impacts exerted by river-groundwater transformation in Junggar Basin, China

NASA Astrophysics Data System (ADS)

Wang, Wenke; Wang, Zhan; Hou, Rongzhe; Guan, Longyao; Dang, Yan; Zhang, Zaiyong; Wang, Hao; Duan, Lei; Wang, Zhoufeng

2018-05-01

The hydrodynamic processes and impacts exerted by river-groundwater transformation need to be studied at regional and catchment scale, especially with respect to diverse geology and lithology. This work adopted an integrated method to study four typical modes (characterized primarily by lithology, flow subsystems, and gaining/losing river status) and the associated hydrodynamic processes and ecological impacts in the southern part of Junggar Basin, China. River-groundwater transformation occurs one to four times along the basin route. For mode classification, such transformation occurs: once or twice, controlled by lithological factors (mode 1); twice, impacted by geomorphic features and lithological structures (mode 2); and three or four times, controlled by both geological and lithological structures (modes 3 and 4). Results also suggest: (1) there exist local and regional groundwater flow subsystems at 400 m depth, which form a multistage nested groundwater flow system. The groundwater flow velocities are 0.1-1.0 and <0.1 m/day for each of two subsystems; (2) the primary groundwater hydro-chemical type takes on apparent horizontal and vertical zoning characteristics, and the TDS of the groundwater evidently increases along the direction of groundwater flow, driven by hydrodynamic processes; (3) the streams, wetland and terminal lakes are the end-points of the local and regional groundwater flow systems. This work indicates that not only are groundwater and river water derived from the same source, but also hydrodynamic and hydro-chemical processes and ecological effects, as a whole in arid areas, are controlled by stream-groundwater transformation.

Simulating the impact of glaciations on continental groundwater flow systems: 1. Relevant processes and model formulation

NASA Astrophysics Data System (ADS)

Lemieux, J.-M.; Sudicky, E. A.; Peltier, W. R.; Tarasov, L.

2008-09-01

In the recent literature, it has been shown that Pleistocene glaciations had a large impact on North American regional groundwater flow systems. Because of the myriad of complex processes and large spatial scales involved during periods of glaciation, numerical models have become powerful tools to examine how ice sheets control subsurface flow systems. In this paper, the key processes that must be represented in a continental-scale 3-D numerical model of groundwater flow during a glaciation are reviewed, including subglacial infiltration, density-dependent (i.e., high-salinity) groundwater flow, permafrost evolution, isostasy, sea level changes, and ice sheet loading. One-dimensional hydromechanical coupling associated with ice loading and brine generation were included in the numerical model HydroGeoSphere and tested against newly developed exact analytical solutions to verify their implementation. Other processes such as subglacial infiltration, permafrost evolution, and isostasy were explicitly added to HydroGeoSphere. A specified flux constrained by the ice sheet thickness was found to be the most appropriate boundary condition in the subglacial environment. For the permafrost, frozen and unfrozen elements can be selected at every time step with specified hydraulic conductivities. For the isostatic adjustment, the elevations of all the grid nodes in each vertical grid column below the ice sheet are adjusted uniformly to account for the Earth's crust depression and rebound. In a companion paper, the model is applied to the Wisconsinian glaciation over the Canadian landscape in order to illustrate the concepts developed in this paper and to better understand the impact of glaciation on 3-D continental groundwater flow systems.

Integrated Hydro-geomorphological Monitoring System of the Upper Bussento river basin (Cilento and Vallo Diano Geopark, S-Italy)

NASA Astrophysics Data System (ADS)

Guida, D.; Cuomo, A.; Longobardi, A.; Villani, P.; Guida, M.; Guadagnuolo, D.; Cestari, A.; Siervo, V.; Benevento, G.; Sorvino, S.; Doto, R.; Verrone, M.; De Vita, A.; Aloia, A.; Positano, P.

2012-04-01

The Mediterranean river ecosystem functionings are supported by river-aquifer interactions. The assessment of their ecological services requires interdisciplinary scientific approaches, integrate monitoring systems and inter-institutional planning and management. This poster illustrates the Hydro-geomorphological Monitoring System build-up in the Upper Bussento river basin by the University of Salerno, in agreement with the local Basin Autorities and in extension to the other river basins located in the Cilento and Vallo Diano National Park (southern Italy), recently accepted in the European Geopark Network. The Monitoring System is based on a hierarchical Hydro-geomorphological Model (HGM), improved in a multiscale, nested and object-oriented Hydro-geomorphological Informative System (HGIS, Figure 1). Hydro-objects are topologically linked and functionally bounded by Hydro-elements at various levels of homogeneity (Table 1). Spatial Hydro-geomorpho-system, HG-complex and HG-unit support respectively areal Hydro-objects, as basin, sector and catchment and linear Hydro-objects, as river, segment, reach and section. Runoff initiation points, springs, disappearing points, junctions, gaining and water losing points complete the Hydro-systems. An automatic procedure use the Pfafstetter coding to hierarchically divide a terrain into arbitrarily small hydro-geomorphological units (basin, interfluve, headwater and no-contribution areas, each with a unique label with hierarchical topological properties. To obtain a hierarchy of hydro-geomorphological units, the method is then applied recursively on each basin and interbasin, and labels of the subdivided regions are appended to the existing label of the original region. The monitoring stations are ranked consequently in main, secondary, temporary and random and located progressively at the points or sections representative for the hydro-geomorphological responses by validation control and modeling calibration. The datasets are organized into a relational geodatabase supporting tracer testings, space-time analysis and hydrological modeling. At the moment, three main station for hourly streamflow measurements are located at the terminal sections of the main basin and the two main sub-basin; secondary stations for weekly discharge measurements are located along the Upper Bussento river segment, upstream and downstream of each river reach or tributary catchments or karst spring inflow. Temporary stations are located in the representative sections of the catchments to detect stream flow losses into alluvial beds or experimental parcels in the bare karst and forested sandstone headwaters. Streamflow measurements are combined with geochemical survey and water sampling for Radon activity concentration measurements. Results of measurement campains in Radon space-time distribution within the basin are given in other contribution of same EGU session. Monitoring results confirm the hourly, daily, weekly and monthly hydrological data and validate outcomes of semi-distributed hydrological models based on previously time series, allowing both academic consultants and institutional subject to extend the Integrated Hydro-geomorphological Monitoring System to the surrounding drainage areas of the Cilento and Vallo di Diano Geopark. Keywords: River-aquifer interaction, Upper Bussento river basin, monitoring system, hydro-geomorphology, semi-distributed hydrological model. Table 1: Comparative, hierarchical Hydro-morpho-climate entities Hierarchy levelArea (Km2) Scale Orography Entity Climate Entity Morfological Entity Areal Drainage Entity Linear Drainage Entity VIII 106 1:15E6 Orogen Macroscale α Morphological Region Hydrological Region VII 105 1:10E6 Chain Sistem Macroscale β Morphological Province Hydrological Province VI 104 1:5E5 Chain Mesoscale α Morphological Sistem Basin River V 103 1:2,5E5Chain Segment Mesoscale β Morphological Sub-systemSub-Basin Torrent IV 100 1:1,0E5Orographic Group Mesoscale γ Morphological Complex Basin Sector Mid Order Channel/ Segment III 10 1: 5E4 Orographic System Microscale αMorphological Unit Watershed Low Order Channel/ Reach II 1 1:2,5E3Orographic ComplexMicroscale βMorphological ComponentCatchment Transient Channel/ Pool I 10-2 1:5E3 Orographic Unit Microscale γMorphological Element Hollow Zero Order Channel PIC

Invited perspectives: Hydrological perspectives on precipitation intensity-duration thresholds for landslide initiation: proposing hydro-meteorological thresholds

NASA Astrophysics Data System (ADS)

Bogaard, Thom; Greco, Roberto

2018-01-01

Many shallow landslides and debris flows are precipitation initiated. Therefore, regional landslide hazard assessment is often based on empirically derived precipitation intensity-duration (ID) thresholds and landslide inventories. Generally, two features of precipitation events are plotted and labeled with (shallow) landslide occurrence or non-occurrence. Hereafter, a separation line or zone is drawn, mostly in logarithmic space. The practical background of ID is that often only meteorological information is available when analyzing (non-)occurrence of shallow landslides and, at the same time, it could be that precipitation information is a good proxy for both meteorological trigger and hydrological cause. Although applied in many case studies, this approach suffers from many false positives as well as limited physical process understanding. Some first steps towards a more hydrologically based approach have been proposed in the past, but these efforts received limited follow-up.Therefore, the objective of our paper is to (a) critically analyze the concept of precipitation ID thresholds for shallow landslides and debris flows from a hydro-meteorological point of view and (b) propose a trigger-cause conceptual framework for lumped regional hydro-meteorological hazard assessment based on published examples and associated discussion. We discuss the ID thresholds in relation to return periods of precipitation, soil physics, and slope and catchment water balance. With this paper, we aim to contribute to the development of a stronger conceptual model for regional landslide hazard assessment based on physical process understanding and empirical data.

CalSimHydro Tool - A Web-based interactive tool for the CalSim 3.0 Hydrology Prepropessor

NASA Astrophysics Data System (ADS)

Li, P.; Stough, T.; Vu, Q.; Granger, S. L.; Jones, D. J.; Ferreira, I.; Chen, Z.

2011-12-01

CalSimHydro, the CalSim 3.0 Hydrology Preprocessor, is an application designed to automate the various steps in the computation of hydrologic inputs for CalSim 3.0, a water resources planning model developed jointly by California State Department of Water Resources and United States Bureau of Reclamation, Mid-Pacific Region. CalSimHydro consists of a five-step FORTRAN based program that runs the individual models in succession passing information from one model to the next and aggregating data as required by each model. The final product of CalSimHydro is an updated CalSim 3.0 state variable (SV) DSS input file. CalSimHydro consists of (1) a Rainfall-Runoff Model to compute monthly infiltration, (2) a Soil moisture and demand calculator (IDC) that estimates surface runoff, deep percolation, and water demands for natural vegetation cover and various crops other than rice, (3) a Rice Water Use Model to compute the water demands, deep percolation, irrigation return flow, and runoff from precipitation for the rice fields, (4) a Refuge Water Use Model that simulates the ponding operations for managed wetlands, and (5) a Data Aggregation and Transfer Module to aggregate the outputs from the above modules and transfer them to the CalSim SV input file. In this presentation, we describe a web-based user interface for CalSimHydro using Google Earth Plug-In. The CalSimHydro tool allows users to - interact with geo-referenced layers of the Water Budget Areas (WBA) and Demand Units (DU) displayed over the Sacramento Valley, - view the input parameters of the hydrology preprocessor for a selected WBA or DU in a time series plot or a tabular form, - edit the values of the input parameters in the table or by downloading a spreadsheet of the selected parameter in a selected time range, - run the CalSimHydro modules in the backend server and notify the user when the job is done, - visualize the model output and compare it with a base run result, - download the output SV file to be used to run CalSim 3.0. The CalSimHydro tool streamlines the complicated steps to configure and run the hydrology preprocessor by providing a user-friendly visual interface and back-end services to validate user inputs and manage the model execution. It is a powerful addition to the new CalSim 3.0 system.

Using the adaptive cycle in climate-risk insurance to design resilient futures

NASA Astrophysics Data System (ADS)

Cremades, R.; Surminski, S.; Máñez Costa, M.; Hudson, P.; Shrivastava, P.; Gascoigne, J.

2018-01-01

Assessing the dynamics of resilience could help insurers and governments reduce the costs of climate-risk insurance schemes and secure future insurability in the face of an increase in extreme hydro-meteorological events related to climate change.

Hydro-climatic Changes: Potential Non-linear Responses of Phosphorus Dynamic in Aquatic/Semi-aquatic Systems

NASA Astrophysics Data System (ADS)

Pant, H. K.

2007-12-01

Depending on resilience, threshold and lag times, hydro-climatic changes can cause nonlinear and/or irreversible changes in phosphorus (P) dynamic, and instigate P enrichment in aquatic/semi-aquatic systems. Thus, studying direct/indirect effects of expected global climate change on bioavailability of organic P in aquatic systems are in critical need, to help manage or increase the resilience of the ecosystem. The central hypothesis of this study is that P dynamic in aquatic, especially freshwater, ecosystem is likely to behave nonlinearly due to expected changes in sediment and water acidity, redox status, etc., because of potential hydro-climatic changes in the decades to come, thus, could face irreversible adverse changes. Devising possible biological and chemical treatments for the removal of P from eutrophic lakes, estuaries, etc, as well as helping in predicting the movement and fate of P under changing hydro-climatic conditions would be crucial to manage aquatic ecosystem in the near future. The critical question is not how much P is stored in any given aquatic/semi-aquatic system, but how the resilience and nonlinearity relate to the stability of stored P are affected due to the levels of environmental stressors, which are expected to fluctuate due to global change in the decades to come. Studies related to 31P Nuclear Magnetic Resonance Spectroscopy analysis, and multiple hydraulic retention cycles showed that, in general, frequent drying and reflooding of a semi-aquatic system such as wetland could significantly increase the bioavailability of P due to degradation of relatively less stable organic P, e.g., glycerophosphate and nucleoside monophosphate. Moreover, nutrients flux from sediments to the water column depended on the concentration gradients of the sediment-water interface and redox status. Shift in equilibrium P concentration of the water column as the water level rises, may cause release of adsorbed P from the sediments. Restoration of a eutrophic system may involve stepwise efforts including control of catchment nutrient inputs, internal nutrient loading, and biomanipulation, however, flooding, previously non-flooded areas, could export massive amount of P to nearby aquatic bodies, in turn, may cause collapse of the ecosystem.

Fully coupled approach to modeling shallow water flow, sediment transport, and bed evolution in rivers

NASA Astrophysics Data System (ADS)

Li, Shuangcai; Duffy, Christopher J.

2011-03-01

Our ability to predict complex environmental fluid flow and transport hinges on accurate and efficient simulations of multiple physical phenomenon operating simultaneously over a wide range of spatial and temporal scales, including overbank floods, coastal storm surge events, drying and wetting bed conditions, and simultaneous bed form evolution. This research implements a fully coupled strategy for solving shallow water hydrodynamics, sediment transport, and morphological bed evolution in rivers and floodplains (PIHM_Hydro) and applies the model to field and laboratory experiments that cover a wide range of spatial and temporal scales. The model uses a standard upwind finite volume method and Roe's approximate Riemann solver for unstructured grids. A multidimensional linear reconstruction and slope limiter are implemented, achieving second-order spatial accuracy. Model efficiency and stability are treated using an explicit-implicit method for temporal discretization with operator splitting. Laboratory-and field-scale experiments were compiled where coupled processes across a range of scales were observed and where higher-order spatial and temporal accuracy might be needed for accurate and efficient solutions. These experiments demonstrate the ability of the fully coupled strategy in capturing dynamics of field-scale flood waves and small-scale drying-wetting processes.

Steps Towards Understanding Large-scale Deformation of Gas Hydrate-bearing Sediments

NASA Astrophysics Data System (ADS)

Gupta, S.; Deusner, C.; Haeckel, M.; Kossel, E.

2016-12-01

Marine sediments bearing gas hydrates are typically characterized by heterogeneity in the gas hydrate distribution and anisotropy in the sediment-gas hydrate fabric properties. Gas hydrates also contribute to the strength and stiffness of the marine sediment, and any disturbance in the thermodynamic stability of the gas hydrates is likely to affect the geomechanical stability of the sediment. Understanding mechanisms and triggers of large-strain deformation and failure of marine gas hydrate-bearing sediments is an area of extensive research, particularly in the context of marine slope-stability and industrial gas production. The ultimate objective is to predict severe deformation events such as regional-scale slope failure or excessive sand production by using numerical simulation tools. The development of such tools essentially requires a careful analysis of thermo-hydro-chemo-mechanical behavior of gas hydrate-bearing sediments at lab-scale, and its stepwise integration into reservoir-scale simulators through definition of effective variables, use of suitable constitutive relations, and application of scaling laws. One of the focus areas of our research is to understand the bulk coupled behavior of marine gas hydrate systems with contributions from micro-scale characteristics, transport-reaction dynamics, and structural heterogeneity through experimental flow-through studies using high-pressure triaxial test systems and advanced tomographical tools (CT, ERT, MRI). We combine these studies to develop mathematical model and numerical simulation tools which could be used to predict the coupled hydro-geomechanical behavior of marine gas hydrate reservoirs in a large-strain framework. Here we will present some of our recent results from closely co-ordinated experimental and numerical simulation studies with an objective to capture the large-deformation behavior relevant to different gas production scenarios. We will also report on a variety of mechanically relevant test scenarios focusing on effects of dynamic changes in gas hydrate saturation, highly uneven gas hydrate distributions, focused fluid migration and gas hydrate production through depressurization and CO2 injection.

Large scale hydro-economic modelling for policy support

NASA Astrophysics Data System (ADS)

de Roo, Ad; Burek, Peter; Bouraoui, Faycal; Reynaud, Arnaud; Udias, Angel; Pistocchi, Alberto; Lanzanova, Denis; Trichakis, Ioannis; Beck, Hylke; Bernhard, Jeroen

2014-05-01

To support European Union water policy making and policy monitoring, a hydro-economic modelling environment has been developed to assess optimum combinations of water retention measures, water savings measures, and nutrient reduction measures for continental Europe. This modelling environment consists of linking the agricultural CAPRI model, the LUMP land use model, the LISFLOOD water quantity model, the EPIC water quality model, the LISQUAL combined water quantity, quality and hydro-economic model, and a multi-criteria optimisation routine. With this modelling environment, river basin scale simulations are carried out to assess the effects of water-retention measures, water-saving measures, and nutrient-reduction measures on several hydro-chemical indicators, such as the Water Exploitation Index (WEI), Nitrate and Phosphate concentrations in rivers, the 50-year return period river discharge as an indicator for flooding, and economic losses due to water scarcity for the agricultural sector, the manufacturing-industry sector, the energy-production sector and the domestic sector, as well as the economic loss due to flood damage. Recently, this model environment is being extended with a groundwater model to evaluate the effects of measures on the average groundwater table and available resources. Also, water allocation rules are addressed, while having environmental flow included as a minimum requirement for the environment. Economic functions are currently being updated as well. Recent development and examples will be shown and discussed, as well as open challenges.

Role of model structure on the response of soil biogeochemistry to hydro-climatic fluctuations

NASA Astrophysics Data System (ADS)

Manzoni, S.; Porporato, A.

2005-05-01

Soil carbon and nutrient cycles are strongly affected by hydro-climatic variability, which interacts with the internal ecosystem structure. Here we test the implications of biogeochemical model structure on such dynamics by extending an existing model by the authors and coworkers. When forced by hydro-climatic fluctuations, the different model structures induce specific preferential nutrient paths among the soil pools, which in turn affect nutrient distribution and availability to microbes and plants. In particular, if it is assumed that microbes can directly assimilate organic nitrogen, plants tend to be inferior competitors for nutrients even in well-watered conditions, while if a certain amount of organic nitrogen is assumed to be mineralized without being first incorporated into microbial cells, vegetation can be advantaged over a wide range of soil moisture values. We also investigate the intensification of competition for nutrients (e.g., nitrogen) between plant and soil microbial communities under extreme hydrologic conditions, such as droughts and intense storms. Frequent rainfall events may determine ideal soil moisture conditions for plant uptake, enhancing nitrogen leaching while lowering oxygen concentration and inhibiting microbial activity. During droughts, the soil water potential often drops to the point of hampering the plant nutrient uptake while still remaining high enough for microbial decomposition and nitrogen immobilization. The interplay of microbe and vegetation water stress is investigated in depth as it controls the ability of one community (e.g., plants or soil microbes) to establish competitive advantage on the other. The long-term effects of these dynamics of competition and nutrient allocation are explored under steady-state and stochastic soil moisture conditions to analyze the feedbacks between soil organic matter and vegetation dynamics.

Quantifying Subsurface Water and Heat Distribution and its Linkage with Landscape Properties in Terrestrial Environment using Hydro-Thermal-Geophysical Monitoring and Coupled Inverse Modeling

NASA Astrophysics Data System (ADS)

Dafflon, B.; Tran, A. P.; Wainwright, H. M.; Hubbard, S. S.; Peterson, J.; Ulrich, C.; Williams, K. H.

2015-12-01

Quantifying water and heat fluxes in the subsurface is crucial for managing water resources and for understanding the terrestrial ecosystem where hydrological properties drive a variety of biogeochemical processes across a large range of spatial and temporal scales. Here, we present the development of an advanced monitoring strategy where hydro-thermal-geophysical datasets are continuously acquired and further involved in a novel inverse modeling framework to estimate the hydraulic and thermal parameter that control heat and water dynamics in the subsurface and further influence surface processes such as evapotranspiration and vegetation growth. The measured and estimated soil properties are also used to investigate co-interaction between subsurface and surface dynamics by using above-ground aerial imaging. The value of this approach is demonstrated at two different sites, one in the polygonal shaped Arctic tundra where water and heat dynamics have a strong impact on freeze-thaw processes, vegetation and biogeochemical processes, and one in a floodplain along the Colorado River where hydrological fluxes between compartments of the system (surface, vadose zone and groundwater) drive biogeochemical transformations. Results show that the developed strategy using geophysical, point-scale and aerial measurements is successful to delineate the spatial distribution of hydrostratigraphic units having distinct physicochemical properties, to monitor and quantify in high resolution water and heat distribution and its linkage with vegetation, geomorphology and weather conditions, and to estimate hydraulic and thermal parameters for enhanced predictions of water and heat fluxes as well as evapotranspiration. Further, in the Colorado floodplain, results document the potential presence of only periodic infiltration pulses as a key hot moment controlling soil hydro and biogeochemical functioning. In the arctic, results show the strong linkage between soil water content, thermal parameters, thaw layer thickness and vegetation distribution. Overall, results of these efforts demonstrate the value of coupling various datasets at high spatial and temporal resolution to improve predictive understanding of subsurface and surface dynamics.

Computing Real-time Streamflow Using Emerging Technologies: Non-contact Radars and the Probability Concept

NASA Astrophysics Data System (ADS)

Fulton, J. W.; Bjerklie, D. M.; Jones, J. W.; Minear, J. T.

2015-12-01

Measuring streamflow, developing, and maintaining rating curves at new streamgaging stations is both time-consuming and problematic. Hydro 21 was an initiative by the U.S. Geological Survey to provide vision and leadership to identify and evaluate new technologies and methods that had the potential to change the way in which streamgaging is conducted. Since 2014, additional trials have been conducted to evaluate some of the methods promoted by the Hydro 21 Committee. Emerging technologies such as continuous-wave radars and computationally-efficient methods such as the Probability Concept require significantly less field time, promote real-time velocity and streamflow measurements, and apply to unsteady flow conditions such as looped ratings and unsteady-flood flows. Portable and fixed-mount radars have advanced beyond the development phase, are cost effective, and readily available in the marketplace. The Probability Concept is based on an alternative velocity-distribution equation developed by C.-L. Chiu, who pioneered the concept. By measuring the surface-water velocity and correcting for environmental influences such as wind drift, radars offer a reliable alternative for measuring and computing real-time streamflow for a variety of hydraulic conditions. If successful, these tools may allow us to establish ratings more efficiently, assess unsteady flow conditions, and report real-time streamflow at new streamgaging stations.

Hydro- and sediment dynamics in the estuary zone of the Mekong Delta: case study Dinh An estuary.

NASA Astrophysics Data System (ADS)

Tran, Anh Tuan; Thoss, Heiko; Gratiot, Nicolas; Dussouillez, Philippe; Brunier, Guillaume; Apel, Heiko

2017-04-01

The Mekong River is the tenth largest river in the world, covers an area of 795,000 km2, 4400km in length, the main river flows over the six countries including: China, Myanmar, Thailand, Laos, Cambodia and Vietnam. Its water discharge is 470 km3year-1 and the sediment discharge is estimated about 160 million ton year-1. The sediment transported by the Mekong River is the key factor in the formation and development of the delta. It is a vital factor for the stability of the coastline and river banks. Furthermore it compensates land subsidence by floodplain deposition, and is the major natural nutrient source for agriculture and aquaculture. However, only a few studies were conducted to characterize and quantify sediment properties and process in the Delta. Also the morphodynamic processes were hardly studied systematically. Hence, this study targets to fill some important and open knowledge gaps with extensive field works that provide important information about the sediment properties and hydrodynamic processes in different seasons Firstly three field survey campaigns are carried out along a 30 km section of the Bassac River from the beginning of Cu Lao Dung Island to Dinh An estuary in 2015 and 2016. During the field campaign, the movement of the salt wedge and the turbidity were monitored by vertical profiles along the river, as well as discharge measurements by ADCP were carried out at three cross sections continuously for 72 hours. The extension of the salt wedge in the river was determined, along with mixing processes. The movement and dynamics observed under different flow conditions indicate that sediment was pumped during low flow upwards the river, while during high flow net transport towards the sea dominated. Also a distinct difference in the sediment properties in the different seasons was observed, with a general tendency towards a higher proportion of coarser particles in the high flow season. These quantitative results give insights into the important sediment dynamics in the estuary and the vital sediment transport towards the coast of the Mekong delta, which is the basis for morphological stability of the coast. The results of the field campaigns will be used for the development of a detailed 3D sediment transport model (Delft 3D) for the quantification of the morphodynamic processes at Dinh An estuary.

Conference on Fluid Machinery, 8th, Budapest, Hungary, Sept. 1987, Proceedings. Volumes 1 & 2

NASA Astrophysics Data System (ADS)

Szabo, A.; Kisbocskoi, L.

The present conference on turbomachine fluid mechanics gives attention to the analysis of labyrinth seals, irrigation turbomachinery, axial-flow fans, poppet valves, the generation of Karman vortices, self-rectifying Wells-type air turbines, computer simulations for water-supply systems, the computation of meridional flow in turbomachines, entrained air effects on vortex pump performance, the three-dimensional potential flow in a draft tube, and hydro powerplant diagnostic methods. Also discussed are a mathematical model for the initiation of cavitation wear, cryogenic flow in ejectors, flow downstream of guide vanes in a Kaplan turbine, unsteady flow in rotating cascades, novel methods for turbomachine vibration monitoring, cavitation breakdown in centrifugal pumps, test results for Banki turbines, centrifugal compressor return-channel flow, performance predictions for regenerative turbomachines, and secondary flows in a centrifugal pump.

Real options valuation and optimization of energy assets

NASA Astrophysics Data System (ADS)

Thompson, Matthew

In this thesis we present algorithms for the valuation and optimal operation of natural gas storage facilities, hydro-electric power plants and thermal power generators in competitive markets. Real options theory is used to derive nonlinear partial-integro-differential equations (PIDEs) for the valuation and optimal operating strategies of all types of facilities. The equations are designed to incorporate a wide class of spot price models that can exhibit the same time-dependent, mean-reverting dynamics and price spikes as those observed in most energy markets. Particular attention is paid to the operational characteristics of real energy assets. For natural gas storage facilities these characteristics include: working gas capacities, variable deliverability and injection rates and cycling limitations. For thermal power plants relevant operational characteristics include variable start-up times and costs, control response time lags, minimum generating levels, nonlinear output functions, structural limitations on ramp rates, and minimum up/down time restrictions. For hydro-electric units, head effects and environmental constraints are addressed. We illustrate the models with numerical examples of a gas storage facility, a hydro-electric pump storage facility and a thermal power plant. This PIDE framework is the first in the literature to achieve second order accuracy in characterizing the operating states of hydro-electric and hydro-thermal power plants. The continuous state space representation derived in this thesis can therefore achieve far greater realism in terms of operating state specification than any other method in the literature to date. This thesis is also the first and only to allow for any continuous time jump diffusion processes in order to account for price spikes.

Hydro-isomerization of n-hexane on bi-functional catalyst: Effect of total and hydrogen partial pressures

NASA Astrophysics Data System (ADS)

Thoa, Dao Thi Kim; Loc, Luu Cam

2017-09-01

The effect of both total pressure and hydrogen partial pressure during n-hexane hydro-isomerization over platinum impregnated on HZSM-5 was studied. n-Hexane hydro-isomerization was conducted at atmospheric pressure and 0.7 MPa to observe the influence of total pressure. In order to see the effect of hydrogen partial pressure, the reaction was taken place at different partial pressure of hydrogen varied from 307 hPa to 718 hPa by dilution with nitrogen to keep the total pressure at 0.1 MPa. Physico-chemical characteristics of catalyst were determined by the methods of nitrogen physi-sorption BET, SEM, XRD, TEM, NH3-TPD, TPR, and Hydrogen Pulse Chemi-sorption. Activity of catalyst in the hydro-isomerization of n-hexane was studied in a micro-flow reactor in the temperature range of 225-325 °C; the molar ratio H2/ hydrocarbon: 5.92, concentration of n-hexane: 9.2 mol.%, GHSV 2698 h-1. The obtained catalyst expressed high acid density, good reducing property, high metal dispersion, and good balance between metallic and acidic sites. It is excellent contact for n-hexane hydro-isomerization. At 250 °C, n-hexane conversion and selectivity were as high as 59-76 % and 85-99 %, respectively. It was found that catalytic activity was promoted either by total pressure or hydrogen partial pressure. At total pressure of 0.7 MPa while hydrogen partial pressure of 718 hPa, catalyst produced 63 RON liquid product containing friendly environmental iso-paraffins which is superior blending stock for green gasoline. Hydrogen did not only preserve catalyst actives by depressing hydrocracking and removing coke precursors but also facilitated hydride transfer step in the bi-functional bi-molecular mechanism.

Scale-Invariant Forms of Conservation Equations in Reactive Fields and a Modified Hydro-Thermo-Diffusive Theory of Laminar Flames

NASA Technical Reports Server (NTRS)

Sohrab, Siavash H.; Piltch, Nancy (Technical Monitor)

2000-01-01

A scale-invariant model of statistical mechanics is applied to present invariant forms of mass, energy, linear, and angular momentum conservation equations in reactive fields. The resulting conservation equations at molecular-dynamic scale are solved by the method of large activation energy asymptotics to describe the hydro-thermo-diffusive structure of laminar premixed flames. The predicted temperature and velocity profiles are in agreement with the observations. Also, with realistic physico-chemical properties and chemical-kinetic parameters for a single-step overall combustion of stoichiometric methane-air premixed flame, the laminar flame propagation velocity of 42.1 cm/s is calculated in agreement with the experimental value.

Catchment hydro-biogeochemical response to climate change and future land-use

EPA Science Inventory

The potential interacting effects of climate change and future land-use on hydrological and biogeochemical dynamics rarely have been described at the catchment level and are difficult or impossible to capture through experimentation or observation alone. We apply a new model, Vi...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burton, D.E.; Miller, D.S.; Palmer, T.

The authors describe FLAG, a 3D adaptive free-Lagrange method for unstructured grids. The grid elements were 3D polygons, which move with the flow, and are refined or reconnected as necessary to achieve uniform accuracy. The authors stressed that they were able to construct a 3D hydro version of this code in 3 months, using an object-oriented FORTRAN approach.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leathe, Stephen A.; Enk, Michael D.

This study was designed to develop and apply methods to evaluate the cumulative effects of 20 proposed small hydro projects on the fisheries resources of the Swan River drainage located in northwestern Montana. Fish population and reach classification information was used to estimate total populations of 107,000 brook trout, 65,000 cut-throat trout and 31,000 juvenile bull trout within the tributary system. Distribution, abundance, and life history of fish species in the drainage and their contribution to the sport fishery were considered in the cumulative impact analysis. Bull trout were chosen as the primary species of concern because of their extensivemore » use of project areas, sensitivity to streambed sedimentation, and their importance to the lake and river sport fisheries. Dewatering of hydroelectric diversion zones and streambed sedimentation (resulting from forest and small hydro development) were the major impacts considered. The developer proposed to divert up to the entire streamflow during low flow months because maintenance of recommended minimum bypass flows would not allow profitable project operation. Dewatering was assumed to result in a total loss of fish production in these areas. 105 refs., 19 figs., 38 tabs.« less

Dynamic rating curve assessment in hydrometric stations and calculation of the associated uncertainties : Quality and monitoring indicators

NASA Astrophysics Data System (ADS)

Morlot, Thomas; Perret, Christian; Favre, Anne-Catherine

2013-04-01

Whether we talk about safety reasons, energy production or regulation, water resources management is one of EDF's (French hydropower company) main concerns. To meet these needs, since the fifties EDF-DTG operates a hydrometric network that includes more than 350 hydrometric stations. The data collected allow real time monitoring of rivers (hydro meteorological forecasts at points of interests), as well as hydrological studies and the sizing of structures. Ensuring the quality of stream flow data is a priority. A rating curve is an indirect method of estimating the discharge in rivers based on water level measurements. The value of discharge obtained thanks to the rating curve is not entirely accurate due to the constant changes of the river bed morphology, to the precision of the gaugings (direct and punctual discharge measurements) and to the quality of the tracing. As time goes on, the uncertainty of the estimated discharge from a rating curve « gets older » and increases: therefore the final level of uncertainty remains particularly difficult to assess. Moreover, the current EDF capacity to produce a rating curve is not suited to the frequency of change of the stage-discharge relationship. The actual method does not take into consideration the variation of the flow conditions and the modifications of the river bed which occur due to natural processes such as erosion, sedimentation and seasonal vegetation growth. In order to get the most accurate stream flow data and to improve their reliability, this study undertakes an original « dynamic» method to compute rating curves based on historical gaugings from a hydrometric station. A curve is computed for each new gauging and a model of uncertainty is adjusted for each of them. The model of uncertainty takes into account the inaccuracies in the measurement of the water height, the quality of the tracing, the uncertainty of the gaugings and the aging of the confidence intervals calculated with a variographic analysis. These rating curves enable to provide values of stream flow taking into account the variability of flow conditions, while providing a model of uncertainties resulting from the aging of the rating curves. By taking into account the variability of the flow conditions and the life of the hydrometric station, this original dynamic method can answer important questions in the field of hydrometry such as « How many gaugings a year have to be made so as to produce stream flow data with an average uncertainty of X% ? » and « When and in which range of water flow do we have to realize those gaugings ? ». KEY WORDS : Uncertainty, Rating curve, Hydrometric station, Gauging, Variogram, Stream Flow

Spatio-temporal dynamics in phytobenthos structural properties reveal insights into agricultural catchment dynamics and nutrient fluxes

NASA Astrophysics Data System (ADS)

Reaney, S. M.; Snell, M. A.; Barker, P. A.; Aftab, A.; Barber, N. J.; Benskin, C.; Burke, S.; Cleasby, W.; Haygarth, P.; Jonczyk, J. C.; Owen, G. J.; Perks, M. T.; Quinn, P. F.; Surridge, B.

2016-12-01

Low order streams are spatially extensive, temporally dynamic, systems within the agricultural landscape. This dynamism extends to the aquatic communities within these streams, including the phytobentos, which demonstrates considerable resilience to diffuse anthropogenic nutrient pressures and changing climate dynamics. The phytobenthos community can substantially contribute to the food web, in particular diatoms, which dominate photo-autotrophic assemblages in low order streams. Diatoms are widely used in ecological monitoring because of their high sensitivity to environmental condition, but knowledge is limited on the ecological effects of winter disturbances and variance introduced by multiple and interacting pressures (N, P, sediment), introducing bias in understanding temporal dynamics in benthic diatom communities. Using the environmental time series data from long term monitoring within the River Eden Demonstration Test Catchment programme, we assess the impact of multiple hydro-chemical stressors on phytobenthic community resilience, and synthesize the impact of an extreme winter event. Monthly data from diatom communities collected in the Eden DTC from March 2011 to present show that river flow, strongly coupled to precipitation, is a key driver of these communities. Discharge has a direct effect on communities through scouring, but is also tightly correlated to nutrient delivery, such that 80% of the annual TP load arrives in 10% of the time. Trophic Diatom Index (TDI) values demonstrated considerable resilience by the stability of inter-monthly TDI scores over 5 seasonal cycles against the characterised highly variable hydrological regime. This research demonstrates that well characterised winter disturbances are critical to understanding drivers of aquatic dynamics. This has implications for catchment diffuse pollution policy, farm management and economics, given the climate projections of increases in frequency and intensity of extreme winter events, which may alter instream nutrient fluxes.

Ensemble reconstruction of spatio-temporal extreme low-flow events in France since 1871

NASA Astrophysics Data System (ADS)

Caillouet, Laurie; Vidal, Jean-Philippe; Sauquet, Eric; Devers, Alexandre; Graff, Benjamin

2017-06-01

The length of streamflow observations is generally limited to the last 50 years even in data-rich countries like France. It therefore offers too small a sample of extreme low-flow events to properly explore the long-term evolution of their characteristics and associated impacts. To overcome this limit, this work first presents a daily 140-year ensemble reconstructed streamflow dataset for a reference network of near-natural catchments in France. This dataset, called SCOPE Hydro (Spatially COherent Probabilistic Extended Hydrological dataset), is based on (1) a probabilistic precipitation, temperature, and reference evapotranspiration downscaling of the Twentieth Century Reanalysis over France, called SCOPE Climate, and (2) continuous hydrological modelling using SCOPE Climate as forcings over the whole period. This work then introduces tools for defining spatio-temporal extreme low-flow events. Extreme low-flow events are first locally defined through the sequent peak algorithm using a novel combination of a fixed threshold and a daily variable threshold. A dedicated spatial matching procedure is then established to identify spatio-temporal events across France. This procedure is furthermore adapted to the SCOPE Hydro 25-member ensemble to characterize in a probabilistic way unrecorded historical events at the national scale. Extreme low-flow events are described and compared in a spatially and temporally homogeneous way over 140 years on a large set of catchments. Results highlight well-known recent events like 1976 or 1989-1990, but also older and relatively forgotten ones like the 1878 and 1893 events. These results contribute to improving our knowledge of historical events and provide a selection of benchmark events for climate change adaptation purposes. Moreover, this study allows for further detailed analyses of the effect of climate variability and anthropogenic climate change on low-flow hydrology at the scale of France.

Design of Environmental Flows Below Diversion Hydropower Dams: Is There Benefit to Advanced Streamflow Prediction in Sparse Data Landscapes?

NASA Astrophysics Data System (ADS)

Kibler, K. M.; Alipour, M.

2017-12-01

Diversion hydropower has been shown to significantly alter river flow regimes by dewatering diversion bypass reaches. Data scarcity is one of the foremost challenges to establishing environmental flow regimes below diversion hydropower dams, especially in regions of sparse hydro-meteorological observation. Herein, we test two prediction strategies for generating daily flows in rivers developed with diversion hydropower: a catchment similarity model, and a rainfall-runoff model selected by multi-objective optimization based on soft data. While both methods are designed for ungauged rivers embedded within large regions of sparse hydrologic observation, one is more complex and computationally-intensive. The objective of this study is to assess the benefit of using complex modeling tools in data-sparse landscapes to support design of environmental flow regimes. Models were tested in gauged catchments and then used to simulate a 28-year record of daily flows in 32 ungauged rivers. After perturbing flows with the hydropower diversion, we detect alteration using Indicators of Hydrologic Alteration (IHA) metrics and compare outcomes of the two modeling approaches. The catchment similarity model simulates low flows well (Nash-Sutcliff efficiency (NSE) = 0.91), but poorly represents moderate to high flows (overall NSE = 0.25). The multi-objective rainfall-runoff model performs well overall (NSE = 0.72). Both models agree that flow magnitudes and variability consistently decrease following diversion as temporally-dynamic flows are replaced by static minimal flows. Mean duration of events sustained below the pre-diversion Q75 and mean hydrograph rise and fall rates increase. While we see broad areas of agreement, significant effects and thresholds vary between models, particularly in the representation of moderate flows. Thus, use of simplified streamflow models may bias detected alterations or inadequately characterize pre-regulation flow regimes, providing inaccurate information as a basis for flow regime design. As an alternative, the multi-objective framework can be applied globally, and is robust to common challenges of flow prediction in ungauged rivers, such as equifinality and hydrologic dissimilarity of reference catchments.

hydroPSO: A Versatile Particle Swarm Optimisation R Package for Calibration of Environmental Models

NASA Astrophysics Data System (ADS)

Zambrano-Bigiarini, M.; Rojas, R.

2012-04-01

Particle Swarm Optimisation (PSO) is a recent and powerful population-based stochastic optimisation technique inspired by social behaviour of bird flocking, which shares similarities with other evolutionary techniques such as Genetic Algorithms (GA). In PSO, however, each individual of the population, known as particle in PSO terminology, adjusts its flying trajectory on the multi-dimensional search-space according to its own experience (best-known personal position) and the one of its neighbours in the swarm (best-known local position). PSO has recently received a surge of attention given its flexibility, ease of programming, low memory and CPU requirements, and efficiency. Despite these advantages, PSO may still get trapped into sub-optimal solutions, suffer from swarm explosion or premature convergence. Thus, the development of enhancements to the "canonical" PSO is an active area of research. To date, several modifications to the canonical PSO have been proposed in the literature, resulting into a large and dispersed collection of codes and algorithms which might well be used for similar if not identical purposes. In this work we present hydroPSO, a platform-independent R package implementing several enhancements to the canonical PSO that we consider of utmost importance to bring this technique to the attention of a broader community of scientists and practitioners. hydroPSO is model-independent, allowing the user to interface any model code with the calibration engine without having to invest considerable effort in customizing PSO to a new calibration problem. Some of the controlling options to fine-tune hydroPSO are: four alternative topologies, several types of inertia weight, time-variant acceleration coefficients, time-variant maximum velocity, regrouping of particles when premature convergence is detected, different types of boundary conditions and many others. Additionally, hydroPSO implements recent PSO variants such as: Improved Particle Swarm Optimisation (IPSO), Fully Informed Particle Swarm (FIPS), and weighted FIPS (wFIPS). Finally, an advanced sensitivity analysis using the Latin Hypercube One-At-a-Time (LH-OAT) method and user-friendly plotting summaries facilitate the interpretation and assessment of the calibration/optimisation results. We validate hydroPSO against the standard PSO algorithm (SPSO-2007) employing five test functions commonly used to assess the performance of optimisation algorithms. Additionally, we illustrate how the performance of the optimization/calibration engine is boosted by using several of the fine-tune options included in hydroPSO. Finally, we show how to interface SWAT-2005 with hydroPSO to calibrate a semi-distributed hydrological model for the Ega River basin in Spain, and how to interface MODFLOW-2000 and hydroPSO to calibrate a groundwater flow model for the regional aquifer of the Pampa del Tamarugal in Chile. We limit the applications of hydroPSO to study cases dealing with surface water and groundwater models as these two are the authors' areas of expertise. However, based on the flexibility of hydroPSO we believe this package can be implemented to any model code requiring some form of parameter estimation.

Hydro-Mechanical Modelling of Slow Slip Phenomena at the Subduction Interface.

NASA Astrophysics Data System (ADS)

Petrini, C.; Gerya, T.; Madonna, C.; van Dinther, Y.

2016-12-01

Subduction zones experience a spectrum of slip phenomena, ranging from large devastating megathrust earthquakes to aseismic slow slip events. Slow slip events, lasting hours to years and being perceptible only by instruments, are believed to have the capability to induce large earthquakes. It is also repeatedly proposed that such slow events are controlled by fluid-rock interactions along the subduction interface, thus calling for development of fully coupled seismo-hydro-mechanical modeling approaches to identify their physics and controlling parameters. We present a newly developed finite difference visco-elasto-plastic numerical code with marker-in-cell technique, which fully couples mechanical deformation and fluid flow. We use this to investigate how the presence of fluids in the pore space of a (de)compacting rock matrix affects elastic stress accumulation and release along a fluid-bearing subduction interface. The model simulates the spontaneous occurrence of quasi-periodic slow slip phenomena along self-consistently forming highly localized shearbands, which accommodate shear displacement between two plates. The produced elastic rebound events show a slip velocity on the order of cm/yr, which is in good agreement with measured data. The governing gradual strength decrease along the slowly propagating shear bands is related to a drop in total pressure caused by shear localization at nearly constant (slightly decreasing) fluid pressure. Gradual reduction of the difference between the total and fluid pressure decreases brittle/plastic strength of fluid-bearing rocks along the shear bands, thus providing a dynamic feedback mechanism for the accumulated elastic stress release at the subduction interface.

Experimental optimization of a free vortex propeller runner for micro hydro application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Punit; Nestmann, Franz

2009-09-15

The turbine technology for low head application in the micro hydro range has been vastly neglected despite niche available in scattered regions of valley flows as well as in wastewater canals and other energy recovery schemes, where the available head does not exceed 2 meters. The goal of this study is to develop hydraulically optimized propeller turbines for the micro hydro range with a particular focus on ease of manufacture. This paper presents a wide range of geometrical optimization steps carried out on a propeller runner, whose blades have been designed using the free vortex theory, and operating with amore » gross head from 1.5 to 2 m and discharge of approximately 75 l/s. It further illustrates 3 stages of geometrical modifications carried out on the runner with an objective of optimizing the runner performance. These modifications comprised of changes to the tip angles (both at the runner inlet and exit) as well as the hub angles (at the runner inlet) of the runner blades. The paper also presents an interesting theoretical methodology to analyze the effects of each optimization stage. This method looks at the relative changes to shaft power and discharge at constant head and speed and gives wonderful insight as to how the internal parameters like Euler shaft work and runner hydraulic losses are behaving with respect to each optimization stage. It was found that the performance of the runner was very sensitive to changes to exit tip angle. At two levels of modification, the discharge increased in the range of 15-30%, while shaft power increased in the range of 12-45%, thus influencing the efficiency characteristics. The results of the runner inlet tip modification were very interesting in that a very significant rise of turbine efficiency was recorded from 55% to 74% at the best efficiency point, which was caused by a reduced discharge consumption as well as a higher power generation. It was also found that the optimization study on a propeller runner has reasonably validated the estimates of the free vortex theory despite small deviations. The final runner configuration demonstrated a maximum efficiency of 74% ({+-}1.8%), which is very encouraging from the perspectives of micro hydro application. The paper concludes with recommendations of a series of optimization steps to increase the efficiency of the runner. It also recommends the attempt of Computational Fluid Dynamics both as a validation and optimization tool for future research on propeller runners. (author)« less

Study of hydro-saline characteristics of soils a palm grove in basin of Ouargla (Northern Algerian Sahara)

NASA Astrophysics Data System (ADS)

Rezagui, D.; Bouhoun, M. Daddi; Boutoutaou, D.; Djaghoubi, A.

2016-07-01

Saharan soils are often faced with several problems of development, taking account the hydro-edaphic constraints, mainly of hydric types by water table, mechanical by gypso-calcareous crusts and saline by irrigation waters and upwelling of water table. Our work consists in doing a soil characterization of a palm grove in Ouargla in order to study the constraints hydro-halomorphes. The results show that irrigation water by two plies of Senonian and Mioplcène had a high salinity with a value of 2.83 and 5.10 dS.m-1 respectively. The conduct of irrigation is traditional random of submersion type. The palm grove has a poor drainage with a level of water table 156.67±15.71 cm and salinity of 31.37±34.04 dS.m-1. The drains are open type and their maintenance is not regular. This situation of management of irrigation-drainage promotes the upwelling of water table and the waterlogging in soils. The study of soil profiles shows the existence of mechanical obstruction of gypso-calcareous crusts which limit the entrenchment of the date palms and the leaching of salts. Soil salinity is excessive in profiles with a range of 8.98 ± 4.58 dS.m-1. This accumulation of salts is due to the dynamic ascending and descending of salts respectively under the effect of upwelling of water table and leaching by irrigation. The salinization, the upwelling of water table and the presence of gypso-calcareous crusts recorded in Ouargla testify to a degradation hydro-halomorphe and mechanic of soil which constitute the major constraints in the management of system irrigation-drainage and sustainable agricultural development of the palm groves of the basin of Ouargla. Some hydro-agricultural planning are necessary to apply in the oasis to improve the hydro-mechanical properties of soils in order to reduce their degradation.

Modeling post-fire hydro-geomorphic recovery in the Waldo Canyon Fire

NASA Astrophysics Data System (ADS)

Kinoshita, Alicia; Nourbakhshbeidokhti, Samira; Chin, Anne

2016-04-01

Wildfire can have significant impacts on watershed hydrology and geomorphology by changing soil properties and removing vegetation, often increasing runoff and soil erosion and deposition, debris flows, and flooding. Watershed systems may take several years or longer to recover. During this time, post-fire channel changes have the potential to alter hydraulics that influence characteristics such as time of concentration and increase time to peak flow, flow capacity, and velocity. Using the case of the 2012 Waldo Canyon Fire in Colorado (USA), this research will leverage field-based surveys and terrestrial Light Detection and Ranging (LiDAR) data to parameterize KINEROS2 (KINematic runoff and EROSion), an event oriented, physically-based watershed runoff and erosion model. We will use the Automated Geospatial Watershed Assessment (AGWA) tool, which is a GIS-based hydrologic modeling tool that uses commonly available GIS data layers to parameterize, execute, and spatially visualize runoff and sediment yield for watersheds impacted by the Waldo Canyon Fire. Specifically, two models are developed, an unburned (Bear Creek) and burned (Williams) watershed. The models will simulate burn severity and treatment conditions. Field data will be used to validate the burned watersheds for pre- and post-fire changes in infiltration, runoff, peak flow, sediment yield, and sediment discharge. Spatial modeling will provide insight into post-fire patterns for varying treatment, burn severity, and climate scenarios. Results will also provide post-fire managers with improved hydro-geomorphic modeling and prediction tools for water resources management and mitigation efforts.

76 FR 67167 - Riverbank Hydro No. 1 LLC; Qualified Hydro 20 LLC; Lock Hydro Friends Fund XXXVII; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-31

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14131-000; 14135-000; 14138-000] Riverbank Hydro No. 1 LLC; Qualified Hydro 20 LLC; Lock Hydro Friends Fund XXXVII; Notice of... LLC (Qualified Hydro) and Lock Hydro Friends Fund XXXVI (Lock Hydro) filed preliminary permit...

Coupled Atmosphere-Surface Modeling of Lake Levels of the North American Great Lakes under Climate Change

NASA Astrophysics Data System (ADS)

Lofgren, B. M.; Xiao, C.

2016-12-01

The influence of projected climate change on the water levels of the Great Lakes is subject to considerable uncertainty, and methods that have long been used to determine this sensitivity have been discredited. A strong candidate, albeit expensive, to replace problematic methods is to use outputs that result from dynamical downscaling of future climate simulations, focused on the hydroclimate of the Great Lakes basin. We have produced initial estimates of Great Lakes water levels in the mid- and late 21st century using the Weather Research and Forecasting (WRF) model, including its lake module, driven by lateral boundary conditions from the Geophysical Fluid Dynamics Lab Climate Model version 3.0 (GFDL CM3), under RCP4.5 and 8.5 scenarios. Future lake levels are influenced by the balance between projected general increases in precipitation and increases in evapotranspiration from both land and lake in the basin, driven primarily by the surface radiative energy budget and secondarily by air temperature. The net result was drops in lake level of up to 15 cm, in contrast to the results from much-used older methods, which often projected drops exceeding 1 m. Future plans include increased detail in the simulation of water flow overland and in river channels using WRF-Hydro, and full coupling of regional atmospheric systems with 3-dimensional dynamical lake implementation of the Finite Volume Community Ocean Model (FVCOM).

Seabed ripple morphology and surficial sediment size at the SAX04 experiments near Fort Walton Beach, Florida, fall 2004

USGS Publications Warehouse

Hanes, Daniel M.; Erikson, Li H.; Lescinski, Jamie M.R.; Harney, Jodi N.; Carter, Carissa L.; Hatcher, Gerry A.; Lacy, Jessica R.; Rubin, David M.

2007-01-01

Data presented in this report originates from measurements obtained off the Florida coast (fig. 1) as part of the Sediment Acoustics Experiment (SAX04) and Ripples Department Research Initiative (DRI) (Office of Naval Research (ONR), Critical Benthic Environmental Processes and Modeling, Long Range BAA 04-001, Sept. 10, 2003). The aim of this document is to present methods employed to extract data and the resulting measured ripple characteristics (ripple height, wavelength, and orientation) and seabed grain sizes. Application and analysis of the data with respect to hydro- and morphodynamics will be addressed in subsequent reports. Sediment transport in the coastal region is a complex process involving interactions between flow dynamics, sediments, and bedforms. Sediment type and bed geometry directly influence entrainment of sediments into suspension, and at sites where ripples occur (sand formations on the order of several cm high and less than two meter long wavelengths), the understanding of ripple dynamics is an essential component in improving sediment transport models. To gain a better understanding and ability to predict sediment transport, a field study was undertaken to investigate morphology, orientation, and dynamics of ripples on the seafloor. The data obtained from the field campaign also supports an on-going effort to study the effects of ripples on low grazing acoustic penetration into sandy marine sediments for the detection of objects, such as mines (Jackson and others, 2002).

Flow status of three transboundary rivers in Northern Greece as a tool for hydro-diplomacy

NASA Astrophysics Data System (ADS)

Hatzigiannakis, Eyaggelos; Hatzispiroglou, Ioannis; Arampatzis, Georgios; Ilia, Andreas; Pantelakis, Dimitrios; Filintas, Agathos; Panagopoulos, Andreas

2015-04-01

The aim of this paper is to examine how the river flow monitoring consists a tool for hydro-diplomacy. Management of transboundary catchments and the demand of common water resources, often comprise the cause of conflicts and tension threatening the peaceful coexistence of nations. The Water Framework Directive 2000/60/EU sets a base for water management contributing to common approaches, common goals, common principles as well as providing new definitions and measures for Europe's water resources. In northern Greece the main renewable resources are "imported" (over 25% of its water reserves) and for this reason the implementation of continuous flow measurements throughout the year is necessary, even though difficult to achieve. This paper focuses on the three largest transboundary rivers in Northern Greece. Axios and Strymonas river flow across the region of Central Macedonia in Northern Greece. Axios flows from FYROM to Greece, and Strymonas from Bulgaria to Greece. Nestos river flows from Bulgaria to Greece. The Greek part is in the region of Eastern Macedonia and Thrace in Northern Greece. Significant productive agricultural areas around these rivers are irrigated from them so they are very important for the local society. Measurements of the river flow velocity and the flow depth have been made at bridges. The frequency of the measurements is roughly monthly, because it is expected a significant change in the depth flow and discharge. A series of continuously flow measure-ments were performed during 2013 and 2014 using flowmeters (Valeport and OTT type). The cross-section characteristics, the river flow velocity of segments and the mean water flow velocity and discharge total profile were measured and calculated re-spectively. Measurements are conducted in the framework of the national water resources monitoring network, which is realised in compliance to the Water Framework Directive under the supervision and coordination of the Hellenic Ministry for the Environment and Climate Change. This project is elaborated in the framework of the operational program "Environment and Sustainable Development" which is co-funded by the National Strategic Reference Framework (NSRF) and the Public Investment Program (PIP).

Blade number impact on pressure and performance of archimedes screw turbine using CFD

NASA Astrophysics Data System (ADS)

Maulana, Muhammad Ilham; Syuhada, Ahmad; Nawawi, Muhammad

2018-02-01

Many rivers in Indonesia can be used as source of mini/micro hydro power plant using low head turbine. The most suitable type of turbine used in fluid flow with low head is the Archimedes screw turbine. The Archimedes screw hydro turbine is a relative newcomer to the small-scale hydropower that can work efficiently on heads as low as 10 meter. In this study, the performance of Archimedes water turbines that has different blade numbers that are thoroughly evaluated to obtain proper blade configuration. For this purpose, numerical simulations are used to predict the pressure changes that occur along the turbine. The simulation results show that turbines with an amount of two blades have more sloping pressure distribution so that it has better stability.

Tidal characteristics of the gulf of Tonkin

NASA Astrophysics Data System (ADS)

Minh, Nguyen Nguyet; Patrick, Marchesiello; Florent, Lyard; Sylvain, Ouillon; Gildas, Cambon; Damien, Allain; Van Uu, Dinh

2014-12-01

The Gulf of Tonkin, situated in the South China Sea, is a zone of strong ecological, touristic and economic interest. Improving our knowledge of its hydro-sedimentary processes is of great importance to the sustainable development of the area. The scientific objective of this study is to revisit the dominant physical processes that characterize tidal dynamics in the Gulf of Tonkin using a high-resolution model and combination of all available data. Particular attention is thus given to model-data cross-examination using tidal gauges and coastal satellite altimetry and to model calibration derived from a set of sensitivity experiments to model parameters. The tidal energy budget of the gulf (energy flux and dissipation) is then analyzed and its resonance properties are evaluated and compared with idealized models and observations. Then, the tidal residual flow in both Eulerian and Lagrangian frameworks is evaluated. Finally, the problem of tidal frontogenesis is addressed to explain the observed summer frontal structures in chlorophyll concentrations.

Effects of conversion of native cerrado vegetation to pasture on soil hydro-physical properties, evapotranspiration and streamflow on the Amazonian agricultural frontier

PubMed Central

Guzha, Alphonce C.; Torres, Gilmar N.; Kovacs, Kristof; Lamparter, Gabriele; Amorim, Ricardo S. S.; Couto, Eduardo; Gerold, Gerhard

2017-01-01

Understanding the impacts of land-use change on landscape-hydrological dynamics is one of the main challenges in the Northern Brazilian Cerrado biome, where the Amazon agricultural frontier is located. Motivated by the gap in literature assessing these impacts, we characterized the soil hydro-physical properties and quantified surface water fluxes from catchments under contrasting land-use in this region. We used data from field measurements in two headwater micro-catchments with similar physical characteristics and different land use, i.e. cerrado sensu stricto vegetation and pasture for extensive cattle ranching. We determined hydraulic and physical properties of the soils, applied ground-based remote sensing techniques to estimate evapotranspiration, and monitored streamflow from October 2012 to September 2014. Our results show significant differences in soil hydro-physical properties between the catchments, with greater bulk density and smaller total porosity in the pasture catchment. We found that evapotranspiration is smaller in the pasture (639 ± 31% mm yr-1) than in the cerrado catchment (1,004 ± 24% mm yr-1), and that streamflow from the pasture catchment is greater with runoff coefficients of 0.40 for the pasture and 0.27 for the cerrado catchment. Overall, our results confirm that conversion of cerrado vegetation to pasture causes soil hydro-physical properties deterioration, reduction in evapotranspiration reduction, and increased streamflow. PMID:28609462

Effects of conversion of native cerrado vegetation to pasture on soil hydro-physical properties, evapotranspiration and streamflow on the Amazonian agricultural frontier.

PubMed

Nóbrega, Rodolfo L B; Guzha, Alphonce C; Torres, Gilmar N; Kovacs, Kristof; Lamparter, Gabriele; Amorim, Ricardo S S; Couto, Eduardo; Gerold, Gerhard

2017-01-01

Understanding the impacts of land-use change on landscape-hydrological dynamics is one of the main challenges in the Northern Brazilian Cerrado biome, where the Amazon agricultural frontier is located. Motivated by the gap in literature assessing these impacts, we characterized the soil hydro-physical properties and quantified surface water fluxes from catchments under contrasting land-use in this region. We used data from field measurements in two headwater micro-catchments with similar physical characteristics and different land use, i.e. cerrado sensu stricto vegetation and pasture for extensive cattle ranching. We determined hydraulic and physical properties of the soils, applied ground-based remote sensing techniques to estimate evapotranspiration, and monitored streamflow from October 2012 to September 2014. Our results show significant differences in soil hydro-physical properties between the catchments, with greater bulk density and smaller total porosity in the pasture catchment. We found that evapotranspiration is smaller in the pasture (639 ± 31% mm yr-1) than in the cerrado catchment (1,004 ± 24% mm yr-1), and that streamflow from the pasture catchment is greater with runoff coefficients of 0.40 for the pasture and 0.27 for the cerrado catchment. Overall, our results confirm that conversion of cerrado vegetation to pasture causes soil hydro-physical properties deterioration, reduction in evapotranspiration reduction, and increased streamflow.

Numerical and experimental study of the pressure pulsations at the free discharge of water through the turbine

NASA Astrophysics Data System (ADS)

Platonov, D. V.

2017-09-01

The free discharge through the turbine is applied in the course of construction of hydro power plant or in case of excessive water inflow during floods or emergency situation. The experimental and numerical investigation of flow-induced pressure pulsation in hydraulic turbine draft tube at free discharge was performed.

78 FR 37212 - Portland General Electric Company; Notice of Application Accepted for Filing, Soliciting Motions...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-20

... install minimum flow turbine generating units. b. Project No.: 2195-088. c. Date Filed: April 10, 2013. d..., Director of Hydro Licensing and Water Rights, Portland General Electric Company, 121 SW Salmon Street... turbine facilities at four locations: 1) a powerhouse at the base of Timothy Lake Dam housing two...

78 FR 21931 - Pelzer Hydro Company, Inc. Consolidated Hydro Southeast, Inc.; Notice of Intent To File License...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-12

...] Pelzer Hydro Company, Inc. Consolidated Hydro Southeast, Inc.; Notice of Intent To File License.... Submitted by: Pelzer Hydro Company, Inc. and Consolidated Hydro Southeast, Inc., both fully owned... at [email protected] . j. Pelzer Hydro Company, Inc. and Consolidated Hydro Southeast, Inc., filed...

76 FR 24471 - Qualified Hydro 26, LLC; Lock+ Hydro Friends Fund VII; Western Minnesota Municipal Power Agency...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-02

...; 14113-000] Qualified Hydro 26, LLC; Lock+ Hydro Friends Fund VII; Western Minnesota Municipal Power... Hydro), Lock+ Hydro Friends Fund VII (Hydro Friends) and Western Minnesota Municipal Power Agency (WMMPA... 02114; (978) 283-2822. Hydro Friends' proposed Lock and Dam 11 Hydropower Project No. 14112 would...

A Brief Hydrodynamic Investigation of a 1/24-Scale Model of the DR-77 Seaplane

NASA Technical Reports Server (NTRS)

Fisher, Lloyd J.; Hoffman, Edward L.

1953-01-01

A limited investigation of a 1/24-scale dynamically similar model of the Navy Bureau of Aeronautics DR-77 design was conducted in Langley tank no. 2 to determine the calm-water take-off and the rough-water landing characteristics of the design with particular regard to the take-off resistance and the landing accelerations. During the take-off tests, resistance, trim, and rise were measured and photographs were taken to study spray. During the landing tests, motion-picture records and normal-acceleration records were obtained. A ratio of gross load to maximum resistance of 3.2 was obtained with a 30 deg. dead-rise hydro-ski installation. The maximum normal accelerations obtained with a 30 deg. dead-rise hydro-ski installation were of the order of 8g to log in waves 8 feet high (full scale). A yawing instability that occurred just prior to hydro-ski emergence was improved by adding an afterbody extension, but adding the extension reduced the ratio of gross load to maximum resistance to 2.9.

Hydro-morphological modelling of small, wave-dominated estuaries

NASA Astrophysics Data System (ADS)

Slinger, Jill H.

2017-11-01

Small, intermittently open or closed estuaries are characteristic of the coasts of South Africa, Australia, California, Mexico and many other areas of the world. However, modelling attention has tended to focus on big estuaries that drain large catchments and serve a wide diversity of interests e.g. agriculture, urban settlement, recreation, commercial fishing. In this study, the development of a simple, parametric, system dynamics model to simulate the opening and closure of the mouths of small, wave-dominated estuaries is reported. In the model, the estuary is conceived as a basin with a specific water volume to water level relationship, connected to the sea by a channel of fixed width, but variable sill height. Changes in the form of the basin are not treated in the model, while the dynamics of the mouth channel are central to the model. The magnitude and direction of the flow through the mouth determines whether erosion or deposition of sediment occurs in the mouth channel, influencing the sill height. The model is implemented on the Great Brak Estuary in South Africa and simulations reveal that the raised low water levels in the estuary during spring tide relative to neap tide, are occasioned by the constriction of the tidal flow through the shallow mouth. Freshwater inflows to the estuary are shown to be significant in determining the behaviour of the inlet mouth, a factor often ignored in studies on tidal inlets. Further it is the balance between freshwater inflows and wave events that determines the opening or closure of the mouth of a particular estuary.

Impact of climate change on freshwater resources in a heterogeneous coastal aquifer of Bremerhaven, Germany: A three-dimensional modeling study.

PubMed

Yang, Jie; Graf, Thomas; Ptak, Thomas

2015-01-01

Climate change is expected to induce sea level rise in the German Bight, which is part of the North Sea, Germany. Climate change may also modify river discharge of the river Weser flowing into the German Bight, which will alter both pressure and salinity distributions in the river Weser estuary. To study the long-term interaction between sea level rise, discharge variations, a storm surge and coastal aquifer flow dynamics, a 3D seawater intrusion model was designed using the fully coupled surface-subsurface numerical model HydroGeoSphere. The model simulates the coastal aquifer as an integral system considering complexities such as variable-density flow, variably saturated flow, irregular boundary conditions, irregular land surface and anthropogenic structures (e.g., dyke, drainage canals, water gates). The simulated steady-state groundwater flow of the year 2009 is calibrated using PEST. In addition, four climate change scenarios are simulated based on the calibrated model: (i) sea level rise of 1m, (ii) the salinity of the seaside boundary increases by 4 PSU (Practical Salinity Units), (iii) the salinity of the seaside boundary decreases by 12 PSU, and (iv) a storm surge with partial dyke failure. Under scenarios (i) and (iv), the salinized area expands several kilometers further inland during several years. Natural remediation can take up to 20 years. However, sudden short-term salinity changes in the river Weser estuary do not influence the salinized area in the coastal aquifer. The obtained results are useful for coastal engineering practices and drinking water resource management. Copyright © 2015 Elsevier B.V. All rights reserved.

Setting up an atmospheric-hydrologic model for seasonal forecasts of water flow into dams in a mountainous semi-arid environment (Cyprus)

NASA Astrophysics Data System (ADS)

Camera, Corrado; Bruggeman, Adriana; Zittis, Georgios; Hadjinicolaou, Panos

2017-04-01

Due to limited rainfall concentrated in the winter months and long dry summers, storage and management of water resources is of paramount importance in Cyprus. For water storage purposes, the Cyprus Water Development Department is responsible for the operation of 56 large dams total volume of 310 Mm3) and 51 smaller reservoirs (total volume of 17 Mm3) over the island. Climate change is also expected to heavily affect Cyprus water resources with a 1.5%-12% decrease in mean annual rainfall (Camera et al., 2016) projected for the period 2020-2050, relative to 1980-2010. This will make reliable seasonal water inflow forecasts even more important for water managers. The overall aim of this study is to set-up the widely used Weather Research and Forecasting (WRF) model with its hydrologic extension (WRF-hydro), for seasonal forecasts of water inflow in dams located in the Troodos Mountains of Cyprus. The specific objectives of this study are: i) the calibration and evaluation of WRF-Hydro for the simulation of stream flows, in the Troodos Mountains, for past rainfall seasons; ii) a sensitivity analysis of the model parameters; iii) a comparison of the application of the atmospheric-hydrologic modelling chain versus the use of climate observations as forcing. The hydrologic model is run in its off-line version with daily forcing over a 1-km grid, while the overland and channel routing is performed on a 100-m grid with a time-step of 6 seconds. Model outputs are exported on a daily base. First, WRF-Hydro is calibrated and validated over two 1-year periods (October-September), using a 1-km gridded observational precipitation dataset (Camera et al., 2014) as input. For the calibration and validation periods, years with annual rainfall close to the long-term average and with the presence of extreme rainfall and flow events were selected. A sensitivity analysis is performed, for the following parameters: partitioning of rainfall into runoff and infiltration (REFKDT), the partitioning of deep percolation between losses and baseflow contribution (LOSS_BASE), water retention depth (RETDEPRTFAC), overland roughness (OVROUGHRTFAC), and channel manning coefficients (MANN). The calibrated WRF-Hydro shows a good ability to reproduce annual total streamflow (-19% error) and total peak discharge volumes (+3% error), although very high values of MANN were used to match the timing of the peak and get positive values of Nash-Sutcliffe efficiency coefficient (0.13). The two most sensitive parameters for the modeled seasonal flow were REFKDT and LOSS_BASE. Simulations of the calibrated WRF-Hydro with WRF modelled atmospheric forcing showed high errors in comparison with those forced with observations, which can be corrected only by modifying the most sensitive parameters by at least one order of magnitude. This study has received funding from the EU H2020 BINGO Project (GA 641739). Camera C., Bruggeman A., Hadjinicolaou P., Pashiardis S., Lange M.A., 2016. Evaluation of interpolation techniques for the creation of gridded daily precipitation (1 × 1 km2); Cyprus, 1980-2010. J Geophys Res Atmos 119, 693-712, DOI:10.1002/2013JD020611 Camera C., Bruggeman A., Hadjinicolaou P., Michaelides S., Lange M.A., 2016. Evaluation of a spatial rainfall generator for generating high resolution precipitation projections over orographically complex terrain. Stoch Environ Res Risk Assess, DOI 10.1007/s00477-016-1239-1

Performance evaluation of the national early warning system for shallow landslides in Norway

NASA Astrophysics Data System (ADS)

Dahl, Mads-Peter; Piciullo, Luca; Devoli, Graziella; Colleuille, Hervé; Calvello, Michele

2017-04-01

As a consequence of the increased number of rainfall-and snowmelt-induced landslides (debris flows, debris slides, debris avalanches and slush flows) occurring in Norway, a national landslide early warning system (EWS) has been developed for monitoring and forecasting the hydro-meteorological conditions potentially necessary of triggering slope failures. The system, operational since 2013, is managed by the Norwegian Water Resources and Energy Directorate (NVE) and has been designed in cooperation with the Norwegian Public Road Administration (SVV), the Norwegian National Rail Administration (JBV) and the Norwegian Meteorological Institute (MET). Decision-making in the EWS is based upon hazard threshold levels, hydro-meteorological and real-time landslide observations as well as landslide inventory and susceptibility maps. Hazard threshold levels have been obtained through statistical analyses of historical landslides and modelled hydro-meteorological parameters. Daily hydro-meteorological conditions such as rainfall, snowmelt, runoff, soil saturation, groundwater level and frost depth have been derived from a distributed version of the hydrological HBV-model. Two different landslide susceptibility maps are used as supportive data in deciding daily warning levels. Daily alerts are issued throughout the country considering variable warning zones. Warnings are issued once per day for the following 3 days with an update possibility later during the day according to the information gathered by the monitoring variables. The performance of the EWS has been evaluated applying the EDuMaP method. In particular, the performance of warnings issued in Western Norway, in the period 2013-2014 has been evaluated using two different landslide datasets. The best performance is obtained for the smallest and more accurate dataset. Different performance results may be observed as a function of changing the landslide density criterion, Lden(k), (i.e., thresholds considered to differentiate among classes of landslide events) used as an input parameter within the EDuMaP method. To investigate this issue, a parametric analysis has been conducted; the results of the analysis show clear differences among computed performances when absolute or relative landslide density criteria are considered.

Analysis of a Complex Faulted CO 2 Reservoir Using a Three-dimensional Hydro-geochemical-Mechanical Approach

DOE PAGES

Nguyen, Ba Nghiep; Hou, Zhangshuan; Bacon, Diana H.; ...

2017-08-18

This work applies a three-dimensional (3D) multiscale approach recently developed to analyze a complex CO 2 faulted reservoir that includes some key geological features of the San Andreas and nearby faults. The approach couples the STOMP-CO2-R code for flow and reactive transport modeling to the ABAQUS ® finite element package for geomechanical analysis. The objective is to examine the coupled hydro-geochemical-mechanical impact on the risk of hydraulic fracture and fault slip in a complex and representative CO 2 reservoir that contains two nearly parallel faults. STOMP-CO2-R/ABAQUS ® coupled analyses of this reservoir are performed assuming extensional and compressional stress regimesmore » to predict evolutions of fluid pressure, stress and strain distributions as well as potential fault failure and leakage of CO 2 along the fault damage zones. The tendency for the faults to slip and pressure margin to fracture are examined in terms of stress regime, mineral composition, crack distributions in the fault damage zones and geomechanical properties. Here, this model in combination with a detailed description of the faults helps assess the coupled hydro-geochemical-mechanical effect.« less

Analysis of a Complex Faulted CO 2 Reservoir Using a Three-dimensional Hydro-geochemical-Mechanical Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Ba Nghiep; Hou, Zhangshuan; Bacon, Diana H.

This work applies a three-dimensional (3D) multiscale approach recently developed to analyze a complex CO 2 faulted reservoir that includes some key geological features of the San Andreas and nearby faults. The approach couples the STOMP-CO2-R code for flow and reactive transport modeling to the ABAQUS ® finite element package for geomechanical analysis. The objective is to examine the coupled hydro-geochemical-mechanical impact on the risk of hydraulic fracture and fault slip in a complex and representative CO 2 reservoir that contains two nearly parallel faults. STOMP-CO2-R/ABAQUS ® coupled analyses of this reservoir are performed assuming extensional and compressional stress regimesmore » to predict evolutions of fluid pressure, stress and strain distributions as well as potential fault failure and leakage of CO 2 along the fault damage zones. The tendency for the faults to slip and pressure margin to fracture are examined in terms of stress regime, mineral composition, crack distributions in the fault damage zones and geomechanical properties. Here, this model in combination with a detailed description of the faults helps assess the coupled hydro-geochemical-mechanical effect.« less

Hydro-mechanical model for wetting/drying and fracture development in geomaterials

DOE PAGES

Asahina, D.; Houseworth, J. E.; Birkholzer, J. T.; ...

2013-12-28

This study presents a modeling approach for studying hydro-mechanical coupled processes, including fracture development, within geological formations. This is accomplished through the novel linking of two codes: TOUGH2, which is a widely used simulator of subsurface multiphase flow based on the finite volume method; and an implementation of the Rigid-Body-Spring Network (RBSN) method, which provides a discrete (lattice) representation of material elasticity and fracture development. The modeling approach is facilitated by a Voronoi-based discretization technique, capable of representing discrete fracture networks. The TOUGH–RBSN simulator is intended to predict fracture evolution, as well as mass transport through permeable media, under dynamicallymore » changing hydrologic and mechanical conditions. Numerical results are compared with those of two independent studies involving hydro-mechanical coupling: (1) numerical modeling of swelling stress development in bentonite; and (2) experimental study of desiccation cracking in a mining waste. The comparisons show good agreement with respect to moisture content, stress development with changes in pore pressure, and time to crack initiation. Finally, the observed relationship between material thickness and crack patterns (e.g., mean spacing of cracks) is captured by the proposed modeling approach.« less

A study on the flow characteristics of a direct drive turbine for energy conversion generation by experiment and CFD

NASA Astrophysics Data System (ADS)

Cho, Y. J.; Zullah, M. A.; Faizal, M.; Choi, Y. D.; Lee, Y. H.

2012-11-01

A variety of technologies has been proposed to capture the energy from waves. Some of the more promising designs are undergoing demonstration testing at commercial scales. Due to the complexity of most offshore wave energy devices and their motion response in different sea states, physical tank tests are common practice for WEC design. Full scale tests are also necessary, but are expensive and only considered once the design has been optimized. Computational Fluid Dynamics (CFD) is now recognized as an important complement to traditional physical testing techniques in offshore engineering. Once properly calibrated and validated to the problem, CFD offers a high density of test data and results in a reasonable timescale to assist with design changes and improvements to the device. The purpose of this study is to investigate the performance of a newly developed direct drive hydro turbine (DDT), which will be built in a caisson for extraction of wave energy. Experiments and CFD analysis are conducted to clarify the turbine performance and internal flow characteristics. The results show that commercial CFD code can be applied successfully to the simulation of the wave motion in the water tank. The performance of the turbine for wave energy converter is studied continuously for a ongoing project.

Appraisal of Weather Research and Forecasting Model Downscaling of Hydro-meteorological Variables and their Applicability for Discharge Prediction: Prognostic Approach for Ungauged Basin

NASA Astrophysics Data System (ADS)

Srivastava, P. K.; Han, D.; Rico-Ramirez, M. A.; Bray, M.; Islam, T.; Petropoulos, G.; Gupta, M.

2015-12-01

Hydro-meteorological variables such as Precipitation and Reference Evapotranspiration (ETo) are the most important variables for discharge prediction. However, it is not always possible to get access to them from ground based measurements, particularly in ungauged catchments. The mesoscale model WRF (Weather Research & Forecasting model) can be used for prediction of hydro-meteorological variables. However, hydro-meteorologists would like to know how well the downscaled global data products are as compared to ground based measurements and whether it is possible to use the downscaled data for ungauged catchments. Even with gauged catchments, most of the stations have only rain and flow gauges installed. Measurements of other weather hydro-meteorological variables such as solar radiation, wind speed, air temperature, and dew point are usually missing and thus complicate the problems. In this study, for downscaling the global datasets, the WRF model is setup over the Brue catchment with three nested domains (D1, D2 and D3) of horizontal grid spacing of 81 km, 27 km and 9 km are used. The hydro-meteorological variables are downscaled using the WRF model from the National Centers for Enviromental Prediction (NCEP) reanalysis datasets and subsequently used for the ETo estimation using the Penman Monteith equation. The analysis of weather variables and precipitation are compared against the ground based datasets, which indicate that the datasets are in agreement with the observed datasets for complete monitoring period as well as during the seasons except precipitation whose performance is poorer in comparison to the measured rainfall. After a comparison, the WRF estimated precipitation and ETo are then used as a input parameter in the Probability Distributed Model (PDM) for discharge prediction. The input data and model parameter sensitivity analysis and uncertainty estimation are also taken into account for the PDM calibration and prediction following the Generalised Likelihood Uncertainty Estimation (GLUE) approach. The overall analysis suggests that the uncertainty estimates in predicted discharge using WRF downscaled ETo have comparable performance to ground based observed datasets and hence is promising for discharge prediction in the absence of ground based measurements.

Integrating Flow, Form, and Function for Improved Environmental Water Management

NASA Astrophysics Data System (ADS)

Albin Lane, Belize Arela

Rivers are complex, dynamic natural systems. The performance of river ecosystem functions, such as habitat availability and sediment transport, depends on the interplay of hydrologic dynamics (flow) and geomorphic settings (form). However, most river restoration studies evaluate the role of either flow or form without regard for their dynamic interactions. Despite substantial recent interest in quantifying environmental water requirements to support integrated water management efforts, the absence of quantitative, transferable relationships between river flow, form, and ecosystem functions remains a major limitation. This research proposes a novel, process-driven methodology for evaluating river flow-form-function linkages in support of basin-scale environmental water management. This methodology utilizes publically available geospatial and time-series data and targeted field data collection to improve basic understanding of river systems with limited data and resource requirements. First, a hydrologic classification system is developed to characterize natural hydrologic variability across a highly altered, physio-climatically diverse landscape. Next, a statistical analysis is used to characterize reach-scale geomorphic variability and to investigate the utility of topographic variability attributes (TVAs, subreach-scale undulations in channel width and depth), alongside traditional reach-averaged attributes, for distinguishing dominant geomorphic forms and processes across a hydroscape. Finally, the interacting roles of flow (hydrologic regime, water year type, and hydrologic impairment) and form (channel morphology) are quantitatively evaluated with respect to ecosystem functions related to hydrogeomorphic processes, aquatic habitat, and riparian habitat. Synthetic river corridor generation is used to evaluate and isolate the role of distinct geomorphic attributes without the need for intensive topographic surveying. This three-part methodology was successfully applied in the Sacramento Basin of California, USA, a large, heavily altered Mediterranean-montane basin. A spatially-explicit hydrologic classification of California distinguished eight natural hydrologic regimes representing distinct flow sources, hydrologic characteristics, and rainfall-runoff controls. A hydro-geomorphic sub-classification of the Sacramento Basin based on stratified random field surveys of 161 stream reaches distinguished nine channel types consisting of both previously identified and new channel types. Results indicate that TVAs provide a quantitative basis for interpreting non-uniform as well as uniform geomorphic processes to better distinguish linked channel forms and functions of ecological significance. Finally, evaluation of six ecosystem functions across alternative flow-form scenarios in the Yuba River watershed highlights critical tradeoffs in ecosystem performance and emphasizes the significance of spatiotemporal diversity of flow and form for maintaining ecosystem integrity. The methodology developed in this dissertation is broadly applicable and extensible to other river systems and ecosystem functions, where findings can be used to characterize complex controls on river ecosystems, assess impacts of proposed flow and form alterations, and inform river restoration strategies. Overall, this research improves scientific understanding of the linkages between hydrology, geomorphology, and river ecosystems to more efficiently allocate scare water resources for human and environmental objectives across natural and built landscapes.

Large-scale Thermo-Hydro-Mechanical Simulations in Complex Geological Environments

NASA Astrophysics Data System (ADS)

Therrien, R.; Lemieux, J.

2011-12-01

The study of a potential deep repository for radioative waste disposal in Canada context requires simulation capabilities for thermo-hydro-mechanical processes. It is expected that the host rock for the deep repository will be subjected to a variety of stresses during its lifetime such as in situ stresses in the rock, stressed caused by excavation of the repository and thermo-mechanical stresses. Another stress of concern for future Canadian climates will results from various episodes of glaciation. In that case, it can be expected that over 3 km of ice may be present over the land mass, which will create a glacial load that will be transmitted to the underlying geological materials and therefore impact their mechanical and hydraulic responses. Glacial loading will affect pore fluid pressures in the subsurface, which will in turn affect groundwater velocities and the potential migration of radionuclides from the repository. In addition, permafrost formation and thawing resulting from glacial advance and retreat will modify the bulk hydraulic of the geological materials and will have a potentially large impact on groundwater flow patterns, especially groundwater recharge. In the context of a deep geological repository for spent nuclear fuel, the performance of the repository to contain the spent nuclear fuel must be evaluated for periods that span several hundred thousand years. The time-frame for thermo-hydro-mechanical simulations is therefore extremely long and efficient numerical techniques must be developed. Other challenges are the representation of geological formations that have potentially complex geometries and physical properties and may contain fractures. The spatial extent of the simulation domain is also very large and can potentially reach the size of a sedimentary basin. Mass transport must also be considered because the fluid salinity in a sedimentary basin can be highly variable and the effect of fluid density on groundwater flow must be accounted for. Adding mass transport with density effect introduces further non-linearities in the governing equations, thus leading to increased simulation times. We will present challenges and current developments related to this topic in the Canadian context. Current efforts aim at improving simulation capabilities for large-scale 3D thermo-hydro-mechanical simulation in complex geologic materials. One topic of interest is to evaluate the appropriateness of simplifying the effect of glacial loading by using a one-dimensional hydro-mechanical representation that assumes purely vertical strain as opposed to the much more computationally intensive 3D representation.

Generation of Complex Karstic Conduit Networks with a Hydro-chemical Model

NASA Astrophysics Data System (ADS)

De Rooij, R.; Graham, W. D.

2016-12-01

The discrete-continuum approach is very well suited to simulate flow and solute transport within karst aquifers. Using this approach, discrete one-dimensional conduits are embedded within a three-dimensional continuum representative of the porous limestone matrix. Typically, however, little is known about the geometry of the karstic conduit network. As such the discrete-continuum approach is rarely used for practical applications. It may be argued, however, that the uncertainty associated with the geometry of the network could be handled by modeling an ensemble of possible karst conduit networks within a stochastic framework. We propose to generate stochastically realistic karst conduit networks by simulating the widening of conduits as caused by the dissolution of limestone over geological relevant timescales. We illustrate that advanced numerical techniques permit to solve the non-linear and coupled hydro-chemical processes efficiently, such that relatively large and complex networks can be generated in acceptable time frames. Instead of specifying flow boundary conditions on conduit cells to recharge the network as is typically done in classical speleogenesis models, we specify an effective rainfall rate over the land surface and let model physics determine the amount of water entering the network. This is advantageous since the amount of water entering the network is extremely difficult to reconstruct, whereas the effective rainfall rate may be quantified using paleoclimatic data. Furthermore, we show that poorly known flow conditions may be constrained by requiring a realistic flow field. Using our speleogenesis model we have investigated factors that influence the geometry of simulated conduit networks. We illustrate that our model generates typical branchwork, network and anastomotic conduit systems. Flow, solute transport and water ages in karst aquifers are simulated using a few illustrative networks.

Statistical analysis and ANN modeling for predicting hydrological extremes under climate change scenarios: the example of a small Mediterranean agro-watershed.

PubMed

Kourgialas, Nektarios N; Dokou, Zoi; Karatzas, George P

2015-05-01

The purpose of this study was to create a modeling management tool for the simulation of extreme flow events under current and future climatic conditions. This tool is a combination of different components and can be applied in complex hydrogeological river basins, where frequent flood and drought phenomena occur. The first component is the statistical analysis of the available hydro-meteorological data. Specifically, principal components analysis was performed in order to quantify the importance of the hydro-meteorological parameters that affect the generation of extreme events. The second component is a prediction-forecasting artificial neural network (ANN) model that simulates, accurately and efficiently, river flow on an hourly basis. This model is based on a methodology that attempts to resolve a very difficult problem related to the accurate estimation of extreme flows. For this purpose, the available measurements (5 years of hourly data) were divided in two subsets: one for the dry and one for the wet periods of the hydrological year. This way, two ANNs were created, trained, tested and validated for a complex Mediterranean river basin in Crete, Greece. As part of the second management component a statistical downscaling tool was used for the creation of meteorological data according to the higher and lower emission climate change scenarios A2 and B1. These data are used as input in the ANN for the forecasting of river flow for the next two decades. The final component is the application of a meteorological index on the measured and forecasted precipitation and flow data, in order to assess the severity and duration of extreme events. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improving National Water Modeling: An Intercomparison of two High-Resolution, Continental Scale Models, CONUS-ParFlow and the National Water Model

NASA Astrophysics Data System (ADS)

Tijerina, D.; Gochis, D.; Condon, L. E.; Maxwell, R. M.

2017-12-01

Development of integrated hydrology modeling systems that couple atmospheric, land surface, and subsurface flow is growing trend in hydrologic modeling. Using an integrated modeling framework, subsurface hydrologic processes, such as lateral flow and soil moisture redistribution, are represented in a single cohesive framework with surface processes like overland flow and evapotranspiration. There is a need for these more intricate models in comprehensive hydrologic forecasting and water management over large spatial areas, specifically the Continental US (CONUS). Currently, two high-resolution, coupled hydrologic modeling applications have been developed for this domain: CONUS-ParFlow built using the integrated hydrologic model ParFlow and the National Water Model that uses the NCAR Weather Research and Forecasting hydrological extension package (WRF-Hydro). Both ParFlow and WRF-Hydro include land surface models, overland flow, and take advantage of parallelization and high-performance computing (HPC) capabilities; however, they have different approaches to overland subsurface flow and groundwater-surface water interactions. Accurately representing large domains remains a challenge considering the difficult task of representing complex hydrologic processes, computational expense, and extensive data needs; both models have accomplished this, but have differences in approach and continue to be difficult to validate. A further exploration of effective methodology to accurately represent large-scale hydrology with integrated models is needed to advance this growing field. Here we compare the outputs of CONUS-ParFlow and the National Water Model to each other and with observations to study the performance of hyper-resolution models over large domains. Models were compared over a range of scales for major watersheds within the CONUS with a specific focus on the Mississippi, Ohio, and Colorado River basins. We use a novel set of approaches and analysis for this comparison to better understand differences in process and bias. This intercomparison is a step toward better understanding how much water we have and interactions between surface and subsurface. Our goal is to advance our understanding and simulation of the hydrologic system and ultimately improve hydrologic forecasts.

Numerical Modelling of Freshwater Inputs in the Shelf Area of the Ofanto River (Southern Italy)

NASA Astrophysics Data System (ADS)

Verri, G.; Pinardi, N.; Tribbia, J. J.; Gochis, D.; Bryan, F.; Tseng, Y. H.; Navarra, A.; Coppini, G.

2016-02-01

The aim of this study is to understand and to assess the effects of river freshwater release on the ocean circulation and dynamics focusing on the shelf area near estuaries. A sensitivity study to different modelling approaches, which point to the representation of the dynamics of the river inflow, are presented. The modeling strategy we chose consists of an integrated modeling chain including the atmosphere, the hydrology/hydraulics and the estuarine dynamics in order to force our regional ocean model at the Ofanto outlet in a reliable way. This meteo-hydrological modeling chain allows us to take into account all the physical processes involved in the local water cycle of the Ofanto catchment such as the rainfall, the land surface infiltration/evaporation, the partitioning of total runoff into surface and subsurface runoff and the channel streamflow. In order to achieve our goal, we chose the Ofanto river catchment and its estuary as case study. The Ofanto river is a torrential river flowing across the Southern Italy and ending in the Adriatic Sea; its annual averaged discharge is low (15 m3s-1 following Raicich, 1996) but may significantly increase when heavy rain events occur. In details our regional ocean model is a finite difference numerical model based on NEMO code (Madec, G., 2008) and implemented in the Central Mediterranean Sea with 2km as horizontal resolution. The meteo-hydrological modeling chain consists of: 1) the WRF-ARW model (Skamarock et al., 2008) including NOAH-MP as Land Surface Submodel,; 2) WRF-HYDRO model (Gochis D., et al., 2013) representing the hydrology/hydraulics component with 200m as horizontal resolution, simulating the streamflow discharge along the Ofanto river network.; 3) finally an estuarine box model (Garvine et al., 2006) is inserted downstream of WRF-Hydro and upstream of the regional ocean model. A set of sensitivity experiments has been performed aiming to evaluate the capability of the regional ocean model to decribe the Ofanto river plume by providing hindcast discharge and salinity from the estuary model at the river mouth with different methods. The time window of the simulations covers the first three months of year 2011, since 4 heavy rain events affected the Ofanto catchment in this period.

Thermo-Hydro-Micro-Mechanical 3D Modeling of a Fault Gouge During Co-seismic Slip

NASA Astrophysics Data System (ADS)

Papachristos, E.; Stefanou, I.; Sulem, J.; Donze, F. V.

2017-12-01

A coupled Thermo-Hydro-Micro-Mechanical (THMM) model based on the Discrete Elements method (DEM) is presented for studying the evolving fault gouge properties during pre- and co-seismic slip. Modeling the behavior of the fault gouge at the microscale is expected to improve our understanding on the various mechanisms that lead to slip weakening and finally control the transition from aseismic to seismic slip.The gouge is considered as a granular material of spherical particles [1]. Upon loading, the interactions between particles follow a frictional behavior and explicit dynamics. Using regular triangulation, a pore network is defined by the physical pore space between the particles. The network is saturated by a compressible fluid, and flow takes place following Stoke's equations. Particles' movement leads to pore deformation and thus to local pore pressure increase. Forces exerted from the fluid onto the particles are calculated using mid-step velocities. The fluid forces are then added to the contact forces resulting from the mechanical interactions before the next step.The same semi-implicit, two way iterative coupling is used for the heat-exchange through conduction.Simple tests have been performed to verify the model against analytical solutions and experimental results. Furthermore, the model was used to study the effect of temperature on the evolution of effective stress in the system and to highlight the role of thermal pressurization during seismic slip [2, 3].The analyses are expected to give grounds for enhancing the current state-of-the-art constitutive models regarding fault friction and shed light on the evolution of fault zone propertiesduring seismic slip.[1] Omid Dorostkar, Robert A Guyer, Paul A Johnson, Chris Marone, and Jan Carmeliet. On the role of fluids in stick-slip dynamics of saturated granular fault gouge using a coupled computational fluid dynamics-discrete element approach. Journal of Geophysical Research: Solid Earth, 122(5):3689-3700, 2017.[2] James R Rice. Heating and weakening of faults during earthquake slip. Journal of Geophysical Research: Solid Earth, 111(B5), 2006.[3] Jean Sulem, Ioannis Stefanou, and Emmanuil Veveakis. Stability analysis of undrained adiabatic shearing of a rock layer with cosserat microstructure. Granular Matter, 13(3):261-268,2011.

Impacts of Different Anthropogenic Aerosol Emission Scenarios on Hydrology in the Mekong Basins and their Effects on Irrigation and Hydropower

NASA Astrophysics Data System (ADS)

Yeo, L. K.; Wang, C.

2016-12-01

Water distribution is closely linked to food and energy security. Aerosol emissions affect cloud properties, as well as atmospheric stability, changing the distribution of precipitation. These changes in precipitation causes changes in water availability, affecting food production and energy generation. These impacts are especially important in Southeast Asia, which uses up to 90% of their water supply for irrigation. In addition, the Mekong river, the largest inland fishery in the world, has 30,000MW of hydropower potential in its lower reaches alone. Modelling the impacts of these anthropogenic emission scenarios will allow us to better understand their downstream effects on hydrology, and any potential feedbacks it may have on future aerosol emissions. In the first step, we run the WRF model using FNL reanlaysis data from 2014 and 2015 to generate the WRF-hydro model forcing inputs. We then run the WRF-hydro model and compare the output with current measurements of soil moisture, river flow, and precipitation. Secondly, we run the WRF-Chem model with various anthropogenic emission scenarios and put the results through the WRF-hydro model to determine the impact of these emission scenarios on soil moisture and river flow. The scenarios include enhanced anthropogenic emissions in Asia, anologous to widespread adoption of coal burning as an energy source in Asia. Anthropogenic emissions have the potential to affect energy policy in countries affected by these emissions. When hydropower generation is affected by changes in precipitation, the affected countries will have to switch to alternative sources of fuel to meet their energy needs. These sources typically result in changes in anthropogenic aerosol emisssions, especially if coal is used as an alternative source of energy.

Increasing the production efficiency and reducing the environmental impacts of hydraulic fracturing

NASA Astrophysics Data System (ADS)

Viswanathan, H. S.

2016-12-01

Shale gas is an unconventional fossil energy resource profoundly impacting US energy independence and is projected to last for at least 100 years. Production of methane and other hydrocarbons from low permeability shale involves hydraulic fracturing of rock, establishing fracture connectivity, and multiphase fluid-flow and reaction processes all of which are poorly understood. The result is inefficient extraction with many environmental concerns. A science-based capability is required to quantify the governing mesoscale fluid-solid interactions, including microstructural control of fracture patterns and the interaction of engineered fluids with hydrocarbon flow. These interactions depend on coupled thermo-hydro-mechanical-chemical (THMC) processes over scales from microns to tens of meters. Determining the key mechanisms in subsurface THMC systems has been impeded due to the lack of sophisticated experimental methods to measure fracture aperture and connectivity, multiphase permeability, and chemical exchange capacities at the high temperature, pressure, and stresses present in the subsurface. In this study, we developed and prototyped the microfluidic and triaxial core flood experiments required to reveal the fundamental dynamics of fracture-fluid interactions. The goal is transformation of hydraulic fracturing from present ad hoc approaches to science-based strategies while safely enhancing production. Specifically, we have demonstrated an integrated experimental/modeling approach that allows for a comprehensive characterization of fluid-solid interactions and develop models that can be used to determine the reservoir operating conditions necessary to gain a degree of control over fracture generation, fluid flow, and interfacial processes over a range of subsurface conditions.

Using a physically-based water flow model to explore the dynamics of transit times and mixing in a small agricultural catchment

NASA Astrophysics Data System (ADS)

Yang, Jie; Heidbüchel, Ingo; Musolff, Andreas; Fleckenstein, Jan H.

2017-04-01

Catchment-scale transit time distributions (TTDs) for discharge and residence time distributions of the water in storage (RTDs) are promising tools to characterize the discharge and mixing behavior of a catchment and can help to interpret the associated solute loads to the stream in a spatially implicit way. TTDs and RTDs are dynamic in time, influenced by dynamic rainfall and evapotranspiration forcing, and changing groundwater storage in the catchment. In order to understand the links between the dynamics of TTDs and groundwater mixing in the small agricultural catchment Schäfertal, in central Germany, a 3D hydrological model was set up for the catchment using the fully coupled surface-subsurface numerical model HydroGeoSphere (HGS). The model is calibrated using discharge and groundwater level measurements, and runs transiently for a period of 10 years from 1997 to 2007. A particle tracking tool was implemented in HGS to track the movement of water parcels in the subsurface, outputting TTDs of channel discharge and RTDs of groundwater storage at daily intervals. Results show that the mean age of the discharge water is significantly younger than that of the water in storage, indicating a poorly mixed subsurface. Discharge preferentially samples faster flowing younger water originating from the more conductive top parts of the aquifer. Spatial variations of the age of water in storage are observed, highly influenced by aquifer heterogeneity. Computed StorAge Selection (SAS) functions [Rinaldo et al. 2015] show clear shifts in the discharge sampling preferences between wet and dry states: during wet states in winter and spring, discharge has a preference for younger water because the shallow flow paths are active due to high groundwater levels and low evapotranspiration. Conversely, during dry states in summer and autumn, discharge has a preference for older water because the shallow flow paths are inactive due to low groundwater levels and stronger evapotranspiration. Measured nitrate (NO3) loads in discharge, mainly originating from fertilizer in shallow soils, decrease significantly with decreasing wetness of the catchment. This trend confirms the shifts of discharge sampling preferences between wet and dry states. Reference: Rinaldo, A., P. Benettin, C. J. Harman, M. Hrachowitz, K. J. McGuire, Y. van der Velde, E. Bertuzzo, and G. Botter (2015), Storage selection functions: A coherent framework for quantifying how catchments store and release water and solutes, Water Resour. Res., 51, 4840-4847, doi:10.1002/2015WR017273.

Hydrologic connectivity in the McMurdo Dry Valleys of Antarctica: System function and changes over two decades

NASA Astrophysics Data System (ADS)

Wlostowski, A. N.; Gooseff, M. N.; Bernzott, E. D.; McKnight, D. M.; Jaros, C.; Lyons, W.

2013-12-01

The McMurdo Dry Valleys of Antarctica is one of the coldest (average annual air temperature of -18°C) and driest (<10cm water equivalent of precip per year) places on earth. Despite the harsh climatic conditions of this landscape, a thriving microbial and invertebrate ecosystem exists, but is limited by the availability of liquid water. So, it is important to quantify temporal and spatial dynamics of hydrologic and ecological connections in the McMurdo Dry Valleys. Intermittent glacial meltwater streams connect glaciers to closed basin lakes and compose the most prominent hydrologic nexus in the valleys. This study uses of 20+ years of stream temperature, electrical conductivity (EC), and discharge data to enhance our quantitative understanding of the temporal dynamics of hydrologic connections along the glacier-stream-lake continuum. Annually, streamflow occurs for a relatively brief 10-12 week period of the austral summer. Longer streams are more prone to intermittent dry periods during the flow season, making for a harsher ecological environment than shorter streams. Diurnal streamflow variation occurs primarily as a result of changing solar postion relative to the source-glacier surfaces. Therfore, different streams predictably experience high flows and low flows at different times of the day. Electrical conductivity also exhibits diel variations, but the nature of EC-discharge relationships differs among streams throughout the valley. Longer streams have higher EC values and lower discharges than shorter streams, suggesting that hyporheic zones act as a significant solute source and hydrologic reservoir along longer streams. Water temperatures are consistently warmer in longer streams, relative to shorter streams, likely due to prolonged exposure to incident radiation with longer surface water residence times. Inter-annually, several shorter streams in the region show significant increases in Q10, Q30, Q50, Q70, Q90, and/or Q100 flows across the 20+ year record, indicating a long-term non-stationarity in hydrologic system dynamics. The tight coupling between surface waters and the glacier surface energy balance bring forth remarkably consistent hydrologic patterns on the daily and annual timescales, providing a model system for understanding fundamental hydro-ecological connectivity. We are beginning to understand long-term inter-annual changes in hydrologic connections in this thermodynamically sensitive landscape, with the aid of well-maintained long-term data sets.

Modeling surface water dynamics in the Amazon Basin using MOSART-Inundation v1.0: Impacts of geomorphological parameters and river flow representation

DOE PAGES

Luo, Xiangyu; Li, Hong -Yi; Leung, L. Ruby; ...

2017-03-23

In the Amazon Basin, floodplain inundation is a key component of surface water dynamics and plays an important role in water, energy and carbon cycles. The Model for Scale Adaptive River Transport (MOSART) was extended with a macroscale inundation scheme for representing floodplain inundation. The extended model, named MOSART-Inundation, was used to simulate surface hydrology of the entire Amazon Basin. Previous hydrologic modeling studies in the Amazon Basin identified and addressed a few challenges in simulating surface hydrology of this basin, including uncertainties of floodplain topography and channel geometry, and the representation of river flow in reaches with mild slopes.more » This study further addressed four aspects of these challenges. First, the spatial variability of vegetation-caused biases embedded in the HydroSHEDS digital elevation model (DEM) data was explicitly addressed. A vegetation height map of about 1 km resolution and a land cover dataset of about 90 m resolution were used in a DEM correction procedure that resulted in an average elevation reduction of 13.2 m for the entire basin and led to evident changes in the floodplain topography. Second, basin-wide empirical formulae for channel cross-sectional dimensions were refined for various subregions to improve the representation of spatial variability in channel geometry. Third, the channel Manning roughness coefficient was allowed to vary with the channel depth, as the effect of riverbed resistance on river flow generally declines with increasing river size. Lastly, backwater effects were accounted for to better represent river flow in mild-slope reaches. The model was evaluated against in situ streamflow records and remotely sensed Envisat altimetry data and Global Inundation Extent from Multi-Satellites (GIEMS) inundation data. In a sensitivity study, seven simulations were compared to evaluate the impacts of the five modeling aspects addressed in this study. The comparisons showed that representing floodplain inundation could significantly improve the simulated streamflow and river stages. Refining floodplain topography, channel geometry and Manning roughness coefficients, as well as accounting for backwater effects had notable impacts on the simulated surface water dynamics in the Amazon Basin. As a result, the understanding obtained in this study could be helpful in improving modeling of surface hydrology in basins with evident inundation, especially at regional to continental scales.« less

Modeling surface water dynamics in the Amazon Basin using MOSART-Inundation v1.0: Impacts of geomorphological parameters and river flow representation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Xiangyu; Li, Hong -Yi; Leung, L. Ruby

In the Amazon Basin, floodplain inundation is a key component of surface water dynamics and plays an important role in water, energy and carbon cycles. The Model for Scale Adaptive River Transport (MOSART) was extended with a macroscale inundation scheme for representing floodplain inundation. The extended model, named MOSART-Inundation, was used to simulate surface hydrology of the entire Amazon Basin. Previous hydrologic modeling studies in the Amazon Basin identified and addressed a few challenges in simulating surface hydrology of this basin, including uncertainties of floodplain topography and channel geometry, and the representation of river flow in reaches with mild slopes.more » This study further addressed four aspects of these challenges. First, the spatial variability of vegetation-caused biases embedded in the HydroSHEDS digital elevation model (DEM) data was explicitly addressed. A vegetation height map of about 1 km resolution and a land cover dataset of about 90 m resolution were used in a DEM correction procedure that resulted in an average elevation reduction of 13.2 m for the entire basin and led to evident changes in the floodplain topography. Second, basin-wide empirical formulae for channel cross-sectional dimensions were refined for various subregions to improve the representation of spatial variability in channel geometry. Third, the channel Manning roughness coefficient was allowed to vary with the channel depth, as the effect of riverbed resistance on river flow generally declines with increasing river size. Lastly, backwater effects were accounted for to better represent river flow in mild-slope reaches. The model was evaluated against in situ streamflow records and remotely sensed Envisat altimetry data and Global Inundation Extent from Multi-Satellites (GIEMS) inundation data. In a sensitivity study, seven simulations were compared to evaluate the impacts of the five modeling aspects addressed in this study. The comparisons showed that representing floodplain inundation could significantly improve the simulated streamflow and river stages. Refining floodplain topography, channel geometry and Manning roughness coefficients, as well as accounting for backwater effects had notable impacts on the simulated surface water dynamics in the Amazon Basin. As a result, the understanding obtained in this study could be helpful in improving modeling of surface hydrology in basins with evident inundation, especially at regional to continental scales.« less

Hydrologic data for urban studies in the Houston, Texas, metropolitan area, 1981

USGS Publications Warehouse

Liscum, Fred

1985-01-01

To ascertain the variation in water quality for different flow conditions and different seasons. This report, the eighteenth in a series of reports to be published annually, is primarily applicable to objective 2. The report presents hydro!ogic data collected in the Houston urban area for the 1981 water year (October 1, 1980 to September 30, 1981).

77 FR 26001 - Qualified Hydro 15, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

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2012-05-02

... have trash racks added. The existing 1,800-foot-long concrete-lined outlet tunnel would be lined with... bifurcation chamber and concrete gatehouse in the stilling basin that would provide flow to the penstock and... be filed electronically via the Internet. See 18 CFR 385.2001(a)(1)(iii) and the instructions on the...

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2012-12-11

...), proposing to study the feasibility of the Marble Bluff Dam Hydropower Project to be located at the U.S. Bureau of Reclamation's Marble Bluff dam on the Truckee River, near Nixon, Washoe County, Nevada. The... east of the existing spillway of the Marble Bluff dam. Flow diverted at the sluice gate would be used...

76 FR 73614 - Lock 14 Hydro Partners; FFP Project 106 LLC; Notice of Competing Preliminary Permit Applications...

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2011-11-29

... applications, pursuant to section 4(f) of the Federal Power Act, proposing to study the feasibility of a... directed by the Corps. Applicant Contact: Mr. David Brown Kinloch, Soft Energy Associates, 414 S. Wenzel... Swaminathan, Free Flow Power Corp., 239 Causeway Street, Suite 300, Boston, MA 02114. (978) 283-2822. FERC...

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2011-11-29

... applications, pursuant to section 4(f) of the Federal Power Act, proposing to study the feasibility of a... Lock and Dam No. 12, as directed by the Corps. Applicant Contact: Mr. David Brown Kinloch, Soft Energy.... Ramya Swaminathan, Free Flow Power Corp., 239 Causeway Street, Suite 300, Boston, MA 02114. (978) 283...

Analyzing hydro abrasive erosion in Kaplan turbine: A case study from India

NASA Astrophysics Data System (ADS)

Rai, Anant Kr.; Kumar, Arun

2016-10-01

Sediment flow through hydro turbine causes erosion of hydraulic components resulting in drop of turbine efficiency, particularly in hydropower plants of the Himalayan region. The measurement of erosion and monitoring of sediment flow in turbine are major concerns in erosion study. Attempts have been made to study erosion mainly in Pelton and Francis turbines. In this study, a simple and effective method has been presented to measure erosion in a Kaplan turbine of a run-of-river scheme Chilla hydropower plant in foothills of Himalaya. Recent techniques were used to measure sediment parameters like concentration, size, shape and mineral content. A standard erosion model is applied to estimate the erosion in Kaplan turbine blade, runner chamber and draft tube cone. A calibration factor has been proposed to apply the erosion model for site specific conditions. It has been found that the outer trailing edges of the turbine blade and upper runner chamber are most erosion prone zones. Sediment analysis revealed that effective operation can reduce erosion in turbine components. The estimated erosion values from model are found to be consistent with measured values. Finally, suggestions for design improvements and effective operation of erosion affected hydropower plants are given.

Simplified Structure of Ducted Darrieus-Type Hydro Turbine with Narrow Intake for Extra-low Head Hydropower Utilization

NASA Astrophysics Data System (ADS)

Matsushita, Daisuke; Okuma, Kusuo; Watanabe, Satoshi; Furukawa, Akinori

A ducted Darrieus-type hydro turbine has been proposed for extra-low head hydropower utilization of total head less than 2m, where development is almost not done in the commercial base. Though the efficiency of Darrieus-type turbine, which is cross flow type, is not so high as conventional type, the Darrieus-type has a cost-advantage due to the simple structure. By installing a narrow intake at upstream of the runner, the efficiency becomes higher than normal intake that a width of which is the same as one of runner section. In the case of normal intake, the casing clearance between the runner pitch circle and the side-wall at the runner section becomes the influential factor which deteriorates the efficiency. On the other hand, in the case of narrow intake, it is possible to keep efficiency high, based on the fact that the distorting flow to the clearance is prevented. In the present paper, the effects of narrow intake and draft tube on turbine performance are experimentally examined and the design guideline of simplified structure for ducted Darrieus-type turbine with narrow intake is proposed.

Pressurized air injection in an axial hydro-turbine model for the mitigation of tip leakage cavitation

NASA Astrophysics Data System (ADS)

Rivetti, A.; Angulo, M.; Lucino, C.; Liscia, S.

2015-12-01

Tip leakage vortex cavitation in axial hydro-turbines may cause erosion, noise and vibration. Damage due to cavitation can be found at the tip of the runner blades on the low pressure side and the discharge ring. In some cases, the erosion follows an oscillatory pattern that is related to the number of guide vanes. That might suggest that a relationship exists between the flow through the guide vanes and the tip vortex cavitating core that induces this kind of erosion. On the other hand, it is known that air injection has a beneficial effect on reducing the damage by cavitation. In this paper, a methodology to identify the interaction between guide vanes and tip vortex cavitation is presented and the effect of air injection in reducing this particular kind of erosion was studied over a range of operating conditions on a Kaplan scale model. It was found that air injection, at the expense of slightly reducing the efficiency of the turbine, mitigates the erosive potential of tip leakage cavitation, attenuates the interaction between the flow through the guide vanes and the tip vortex and decreases the level of vibration of the structural components.

Multifractal characterisation of a simulated surface flow: A case study with Multi-Hydro in Jouy-en-Josas, France

NASA Astrophysics Data System (ADS)

Gires, Auguste; Abbes, Jean-Baptiste; da Silva Rocha Paz, Igor; Tchiguirinskaia, Ioulia; Schertzer, Daniel

2018-03-01

In this paper we suggest to innovatively use scaling laws and more specifically Universal Multifractals (UM) to analyse simulated surface runoff and compare the retrieved scaling features with the rainfall ones. The methodology is tested on a 3 km2 semi-urbanised with a steep slope study area located in the Paris area along the Bièvre River. First Multi-Hydro, a fully distributed model is validated on this catchment for four rainfall events measured with the help of a C-band radar. The uncertainty associated with small scale unmeasured rainfall, i.e. occurring below the 1 km × 1 km × 5 min observation scale, is quantified with the help of stochastic downscaled rainfall fields. It is rather significant for simulated flow and more limited on overland water depth for these rainfall events. Overland depth is found to exhibit a scaling behaviour over small scales (10 m-80 m) which can be related to fractal features of the sewer network. No direct and obvious dependency between the overland depth multifractal features (quality of the scaling and UM parameters) and the rainfall ones was found.

A Shocking New Pump

NASA Technical Reports Server (NTRS)

2000-01-01

Hydro Dynamics, Inc. received a technical helping hand from NASA that made their Hydrosonic Pump (HPump) a reality. Marshall engineers resolved a bearing problem in the rotor of the pump and recommended new bearings, housings and mounting hardware as a solution. The resulting HPump is able to heat liquids with greater energy efficiency using shock waves to generate heat.

HUFF, a One-Dimensional Hydrodynamics Code for Strong Shocks

DTIC Science & Technology

1978-12-01

results for two sample problems. The first problem discussed is a one-kiloton nuclear burst in infinite sea level air. The second problem is the one...of HUFF as an effective first order hydro- dynamic computer code. 1 KT Explosion The one-kiloton nuclear explosion in infinite sea level air was

Hydro-dynamic and geotechnical effects in bridge scour processes

NASA Astrophysics Data System (ADS)

Radice, Alessio; Ballio, Francesco; Tran, Chau

2010-05-01

Local pier and abutment scour is a crucial topic in hydraulic engineering, due to the significant social and economical impact of bridge failure. Therefore, reliable tools for scour prediction are necessary for both design and vulnerability evaluation of the structures. In recent years, phenomenological studies of the local scour dynamics have been undertaken, to yield insight over the small scale mechanisms of the process. Experimental measurement and numerical modelling of the scouring flow field have shown the horseshoe vortex and the principal vortex as the most evident features of the flow pattern at piers and abutments, respectively. The vortex structure near the obstacles typically presents a high turbulence level compared to that of the incoming flow, and the temporal fluctuations in water velocity make the coherent vortical structures unstable in time. Furthermore, the statistical distributions of velocity values in junction flows often present a bimodal shape. The kinematics of the bottom grains reflects the unsteadiness of the flow pattern. Indeed, recent detailed measurements of particle motion in an abutment scour hole proved that a succession of opposite motion events takes place at several locations within the hole. Events of sediment motion directed away from the obstacles can be attributed to sediment pickup and transport by the turbulent flow field, whilst those with motion towards the abutment can be associated to sediment sliding along the slopes of the hole due to geotechnical instability. On a qualitative basis the presence of geotechnical effects is indeed relatively acknowledged. Despite the general agreement on the qualitative features of the scour process, a quantitative definition of the relevance of sliding for the sediment kinematics in a local scour process is still lacking. Therefore, the purpose of the present work has been to make a specific analysis of the different types of sediment motion events, aimed to a quantification of the relevance of sediment sliding for a proper process modelling. Two experimental configurations have been considered, namely a vertical-wall abutment and a circular pier. Attention has been focused on the well developed stages of the erosion process, where the grain instantaneous movements have been divided into two populations, namely the "turbulence-dominated" events (those in which the particle motion is triggered by the turbulent flow field) and the "gravity-dominated" events (those in which the particles slide along the slopes of the scour hole due to geotechnical instability). A relevant difference has been found between the dynamics of gravity-dominated and turbulence-dominated events. In addition, it has been found that the presence of geotechnical effects in the erosion hole may significantly alter the scour rate. Potential implications of the present results for the modelling of local scour processes have been discussed.

77 FR 11530 - Riverbank Hydro No. 2, LLC, Lock+ Hydro Friends Fund XXXVI, Qualified Hydro 21, LLC; Notice...

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2012-02-27

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14130-000, 14137-000, 14134-000] Riverbank Hydro No. 2, LLC, Lock+ Hydro Friends Fund XXXVI, Qualified Hydro 21, LLC; Notice.... 2, LLC for Project No. 14130-000, Lock+ Hydro Friends Fund XXXVI for Project No. 14137-000, and...

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2012-03-06

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14130-000, 14137-000, 14134-000] Riverbank Hydro No. 2, LLC, Lock+ Hydro Friends Fund XXXVI, Qualified Hydro 21, LLC; Notice... drawing, the order of priority is as follows: 1. Lock+ Hydro Friends Fund XXXVI: Project No. 14137-000. 2...

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2010-11-29

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2012-02-29

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14131-000, 14138-00, 14135-000] Riverbank Hydro No. 1, LLC, Lock+ Hydro Friends Fund XXXVII; Qualified Hydro 20, LLC; Notice..., the order of priority is as follows: 1. Lock+ Hydro Friends Fund XXXVII, Project No. 14138-000. 2...

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2012-02-16

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Hydrological modelling improvements required in basins in the Hindukush-Karakoram-Himalayas region

NASA Astrophysics Data System (ADS)

Khan, Asif; Richards, Keith S.; McRobie, Allan; Booij, Martijn

2016-04-01

Millions of people rely on river water originating from basins in the Hindukush-Karakoram-Himalayas (HKH), where snow- and ice-melt are significant flow components. One such basin is the Upper Indus Basin (UIB), where snow- and ice-melt can contribute more than 80% of total flow. Containing some of the world's largest alpine glaciers, this basin may be highly susceptible to global warming and climate change, and reliable predictions of future water availability are vital for resource planning for downstream food and energy needs in a changing climate, but depend on significantly improved hydrological modelling. However, a critical assessment of available hydro-climatic data and hydrological modelling in the HKH region has identified five major failings in many published hydro-climatic studies, even those appearing in reputable international journals. The main weaknesses of these studies are: i) incorrect basin areas; ii) under-estimated precipitation; iii) incorrectly-defined glacier boundaries; iv) under-estimated snow-cover data; and v) use of biased melt factors for snow and ice during the summer months. This paper illustrates these limitations, which have either resulted in modelled flows being under-estimates of measured flows, leading to an implied severe water scarcity; or have led to the use of unrealistically high degree-day factors and over-estimates of glacier melt contributions, implying unrealistic melt rates. These effects vary amongst sub-basins. Forecasts obtained from these models cannot be used reliably in policy making or water resource development, and need revision. Detailed critical analysis and improvement of existing hydrological modelling may be equally necessary in other mountain regions across the world.

Gas dynamic and force effects of a solid particle in a shock wave in air

NASA Astrophysics Data System (ADS)

Obruchkova, L. R.; Baldina, E. G.; Efremov, V. P.

2017-03-01

Shock wave interaction with an adiabatic solid microparticle is numerically simulated. In the simulation, the shock wave is initiated by the Riemann problem with instantaneous removal of a diaphragm between the high- and low-pressure chambers. The calculation is performed in the two-dimensional formulation using the ideal gas equation of state. The left end of the tube is impermeable, while outflow from the right end is permitted. The particle is assumed to be motionless, impermeable, and adiabatic, and the simulation is performed for time intervals shorted than the time of velocity and temperature relaxation of the particle. The numerical grid is chosen for each particle size to ensure convergence. For each particle size, the calculated hydraulic resistance coefficient describing the particle force impact on the flow is compared with that obtained from the analytical Stokes formula. It is discovered that the Stokes formula can be used for calculation of hydraulic resistance of a motionless particle in a shock wave flow. The influence of the particle diameter on the flow perturbation behind the shock front is studied. Specific heating of the flow in front of the particle is calculated and a simple estimate is proposed. The whole heated region is divided by the acoustic line into the subsonic and supersonic regions. It is demonstrated that the main heat generated by the particle in the flow is concentrated in the subsonic region. The calculations are performed using two different 2D hydro codes. The energy release in the flow induced by the particle is compared with the maximum possible heating at complete termination of the flow. The results can be used for estimating the possibility of gas ignition in front of the particle by a shock wave whose amplitude is insufficient for initiating detonation in the absence of a particle.

78 FR 929 - TransCanada Hydro Northeast Inc.; FirstLight Hydro Generating Company; Notice of Intent To File...

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2013-01-07

... P-1904-073; Project Nos. P- 1889-081 and P-2485-063] TransCanada Hydro Northeast Inc.; FirstLight.... Submitted By: TransCanada Hydro Northeast Inc. (P-1892-026, P- 1855-045, and P-1904-073); FirstLight Hydro... Projects--John S. Howard, Director--FERC Hydro Compliance, FirstLight Hydro Generating Company, Northfield...

CUAHSI-HIS: an Internet based system to facilitate public discovery, access, and exploration of different water science data sources

NASA Astrophysics Data System (ADS)

Arrigo, J. S.; Hooper, R. P.; Choi, Y.; Ames, D. P.; Kadlec, J.; Whiteaker, T.

2011-12-01

"Water is everywhere." This sentiment underscores the importance of instilling hydrologic and earth science literacy in educators, students, and the general public, but also presents challenges for water scientists and educators. Scientific data about water is collected and distributed by several different sources, from federal agencies to scientific investigators to citizen scientists. As competition for limited water resources increase, increasing access to and understanding of the wealth of information about the nation's and the world's water will be critical. The CUAHSI-HIS system is a web based system for sharing hydrologic data that can help address this need. HydroDesktop is a free, open source application for finding, getting, analyzing and using hydrologic data from the CUAHSI-HIS system. It works with HydroCatalog which indexes the data to find out what data exists and where it is, and then it retrieves the data from HydroServers where it is stored communicating using WaterOneFlow web services. Currently, there are over 65 services registered in HydroCatalog providing central discovery of water data from several federal and state agencies, university projects, and other sources. HydroDesktop provides a simplified GIS that allows users to incorporate spatial data, and simple analysis tools to facilitate graphing and visualization. HydroDesktop is designed to be useful for a number of different groups of users with a wide variety of needs and skill levels including university faculty, graduate and undergraduate students, K-12 students, engineering and scientific consultants, and others. This presentation will highlight some of the features of HydroDesktop and the CUAHSI-HIS system that make it particularly appropriate for use in educational and public outreach settings, and will present examples of educational use. The incorporation of "real data," localization to an area of interest, and problem-based learning are all recognized as effective strategies for learning. Many example exercises educators create around water may list several websites and data sources (e.g. EPA, USGS, etc.) an educator needs to prepare even a simple exercise. HydroDesktop can simplify this process by providing unified access to several sources. The GIS interface can be used to incorporate local spatial data to allow students to explore environmental factors, and to illustrate concepts, such as watershed delineation. Simple graphing and time series tools can be used to illustrate relationships between different types of data and important water science concepts. CUAHSI is interested in partnering with science PIs to facilitate access to their project data and creating education and outreach materials around them, as well as with educators, public policy professionals and other constituencies to explore how CUAHSI HIS services can be utilized to foster public understanding and consumption of water information.

Steam jacket dynamics in underground coal gasification

NASA Astrophysics Data System (ADS)

Otto, Christopher; Kempka, Thomas

2017-04-01

Underground coal gasification (UCG) has the potential to increase the world-wide hydrocarbon reserves by utilization of deposits not economically mineable by conventional methods. In this context, UCG involves combusting coal in-situ to produce a high-calorific synthesis gas, which can be applied for electricity generation or chemical feedstock production. Apart from high economic potentials, in-situ combustion may cause environmental impacts such as groundwater pollution by by-product leakage. In order to prevent or significantly mitigate these potential environmental concerns, UCG reactors are generally operated below hydrostatic pressure to limit the outflow of UCG process fluids into overburden aquifers. This pressure difference effects groundwater inflow into the reactor and prevents the escape of product gas. In the close reactor vicinity, fluid flow determined by the evolving high reactor temperatures, resulting in the build-up of a steam jacket. Numerical modeling is one of the key components to study coupled processes in in-situ combustion. We employed the thermo-hydraulic numerical simulator MUFITS (BINMIXT module) to address the influence of reactor pressure dynamics as well as hydro-geological coal and caprock parameters on water inflow and steam jacket dynamics. The US field trials Hanna and Hoe Creek (Wyoming) were applied for 3D model validation in terms of water inflow matching, whereby the good agreement between our modeling results and the field data indicates that our model reflects the hydrothermal physics of the process. In summary, our validated model allows a fast prediction of the steam jacket dynamics as well as water in- and outflows, required to avoid aquifer contamination during the entire life cycle of in-situ combustion operations.

Essays on Infrastructure Design and Planning for Clean Energy Systems

NASA Astrophysics Data System (ADS)

Kocaman, Ayse Selin

The International Energy Agency estimates that the number of people who do not have access to electricity is nearly 1.3 billion and a billion more have only unreliable and intermittent supply. Moreover, current supply for electricity generation mostly relies on fossil fuels, which are finite and one of the greatest threats to the environment. Rising population growth rates, depleting fuel sources, environmental issues and economic developments have increased the need for mathematical optimization to provide a formal framework that enables systematic and clear decision-making in energy operations. This thesis through its methodologies and algorithms enable tools for energy generation, transmission and distribution system design and help policy makers make cost assessments in energy infrastructure planning rapidly and accurately. In Chapter 2, we focus on local-level power distribution systems planning for rural electrification using techniques from combinatorial optimization. We describe a heuristic algorithm that provides a quick solution for the partial electrification problem where the distribution network can only connect a pre-specified number of households with low voltage lines. The algorithm demonstrates the effect of household settlement patterns on the electrification cost. We also describe the first heuristic algorithm that selects the locations and service areas of transformers without requiring candidate solutions and simultaneously builds a two-level grid network in a green-field setting. The algorithms are applied to real world rural settings in Africa, where household locations digitized from satellite imagery are prescribed. In Chapter 3 and 4, we focus on power generation and transmission using clean energy sources. Here, we imagine a country in the future where hydro and solar are the dominant sources and fossil fuels are only available in minimal form. We discuss the problem of modeling hydro and solar energy production and allocation, including long-term investments and storage, capturing the stochastic nature of hourly supply and demand data. We mathematically model two hybrid energy generation and allocation systems where time variability of energy sources and demand is balanced using the water stored in the reservoirs. In Chapter 3, we use conventional hydro power stations (incoming stream flows are stored in large dams and water release is deferred until it is needed) and in Chapter 4, we use pumped hydro stations (water is pumped from lower reservoir to upper reservoir during periods of low demand to be released for generation when demand is high). Aim of the models is to determine optimal sizing of infrastructure needed to match demand and supply in a most reliable and cost effective way. An innovative contribution of this work is the establishment of a new perspective to energy modeling by including fine-grained sources of uncertainty such as stream flow and solar radiations in hourly level as well as spatial location of supply and demand and transmission network in national level. In addition, we compare the conventional and the pumped hydro power systems in terms of reliability and cost efficiency and quantitatively show the improvement provided by including pumped hydro storage. The model will be presented with a case study of India and helps to answer whether solar energy in addition to hydro power potential in Himalaya Mountains would be enough to meet growing electricity demand if fossil fuels could be almost completely phased out from electricity generation.

A spatially explicit hydro-ecological modeling framework (BEPS-TerrainLab V2.0): Model description and test in a boreal ecosystem in Eastern North America

NASA Astrophysics Data System (ADS)

Govind, Ajit; Chen, Jing Ming; Margolis, Hank; Ju, Weimin; Sonnentag, Oliver; Giasson, Marc-André

2009-04-01

SummaryA spatially explicit, process-based hydro-ecological model, BEPS-TerrainLab V2.0, was developed to improve the representation of ecophysiological, hydro-ecological and biogeochemical processes of boreal ecosystems in a tightly coupled manner. Several processes unique to boreal ecosystems were implemented including the sub-surface lateral water fluxes, stratification of vegetation into distinct layers for explicit ecophysiological representation, inclusion of novel spatial upscaling strategies and biogeochemical processes. To account for preferential water fluxes common in humid boreal ecosystems, a novel scheme was introduced based on laboratory analyses. Leaf-scale ecophysiological processes were upscaled to canopy-scale by explicitly considering leaf physiological conditions as affected by light and water stress. The modified model was tested with 2 years of continuous measurements taken at the Eastern Old Black Spruce Site of the Fluxnet-Canada Research Network located in a humid boreal watershed in eastern Canada. Comparison of the simulated and measured ET, water-table depth (WTD), volumetric soil water content (VSWC) and gross primary productivity (GPP) revealed that BEPS-TerrainLab V2.0 simulates hydro-ecological processes with reasonable accuracy. The model was able to explain 83% of the ET, 92% of the GPP variability and 72% of the WTD dynamics. The model suggests that in humid ecosystems such as eastern North American boreal watersheds, topographically driven sub-surface baseflow is the main mechanism of soil water partitioning which significantly affects the local-scale hydrological conditions.

Improving the Hydro-stratigraphic Model of the Oxnard Forebay, Ventura County, California, using Transient Electromagnetic Surveying

NASA Astrophysics Data System (ADS)

Quady, Maura Colleen

2013-01-01

To characterize the hydro-stratigraphy of an area, drilling and well logs provide high resolution electrical resistivity data, albeit for limited areas (points). The expense of drilling indirectly leads to sparse data and it is necessary to assume lateral homogeneity between wells when creating stratigraphic maps. Unfortunately, this assumption may not apply to areas in complex depositional and tectonically active settings. The goal of this study is to fill in data gaps between wells in a groundwater basin in order to better characterize the hydro-stratigraphy under existing and potential sites for managed aquifer recharge. Basins in the southern California study area have been used for decades to recharge surface water to an upper aquifer system; this work also addresses whether the local hydro-stratigraphy favors surface infiltration as a means to recharge water to the lower aquifer system. Here, soundings of transient electromagnetism (TEM), a surface geophysical method, are correlated with nearby down-hole resistivity and lithology well logs for grain size interpretations of the subsurface in unsaturated conditions. Grain size is used as a proxy for permeability (hydraulic conductivity), with resistivity contrasts highlighting variations in the media, which would affect groundwater flow in both vertical and horizontal directions. Results suggest a nearly horizontal, extensive, low permeability layer exists in the area and only a few noted locations are favorable for surface -to-lower aquifer system recharge. Furthermore, zones of higher permeability deeper than the upper aquifer system are discontinuous and isolated among lower permeability zones. However, the TEM profiles show areas where lower permeability zones are thin, and where alternatives to surface percolation methods could be explored. In addition, the survey adds information about the transition between the upper and lower aquifer systems, and adds detail to the topography of the base of freshwater. Finally, this work effectively decreases the interpolation distance between data points of wellbores, and when viewed in sequence the TEM profiles present a 3D depiction of basin hydro-stratigraphy.

Integrated hydro-environmental impact assessment and alternative selection of low impact development practices in small urban catchments.

PubMed

Yang, Yang; Chui, Ting Fong May

2018-06-20

Attention is increasingly being paid to low impact development (LID) practices in urban stormwater management. Because LID practices offer a wide variety of hydro-environmental benefits, it is often necessary to account for these benefits collectively in cost-benefit analysis and LID alternative selection. The conventional methods of quantifying these benefits, however, can hardly incorporate the preferences of decision makers, and commonly involve tedious parameter estimations. To address these shortcomings, this study adopts a relative performance evaluation method to assess the various hydro-environmental impacts of LID alternatives in small urban catchments. This study considers several categories of hydro-environmental impacts, including water balance impact, surface pollutant load abatement, and combined sewer overflow and flood risk mitigation. Several performance indicators are used for each impact category. The system-wide effectiveness of an LID alternative is then derived by the weighted aggregation of its indicator scores, which are obtained by comparing its performance with that of all of the other alternatives. The hydro-environmental impact of green roofs and bioretention cells of varying areas in New York City, U.S. are investigated in detail. The results suggest that a green roof that covers the whole catchment is as effective as a bioretention cell that covers 3%-5% of the catchment in terms of stormwater management, and that the effectiveness of a bioretention cell doubles when its surface area increases from 2% to 10% of the catchment area. These assessment results are influenced by catchment-specific assessment criteria (e.g., the high flow threshold) and management interests, which suggests that design guidelines for different catchments should be tailored to their natural and drainage characteristics. The framework used in this study allows stakeholders' interests to be reflected in LID alternative selections and the implications of different design guidelines to be thoroughly investigated. Copyright © 2018 Elsevier Ltd. All rights reserved.

A GIS-Based Model for the analysis of an urban flash flood and its hydro-geomorphic response. The Valencia event of 1957

NASA Astrophysics Data System (ADS)

Portugués-Mollá, I.; Bonache-Felici, X.; Mateu-Bellés, J. F.; Marco-Segura, J. B.

2016-10-01

Flash floods are recurrent events around the Mediterranean region. Extreme episodes activate hydro-geomorphic high-intensity processes with low frequency. In urban environments, the complexity becomes higher due to the existence of very quick-response runoff. However, immediate recovery works remove the urban marks. After a short time both the significance and magnitude of the hydro-geomorphic event become completely unrecognizable. Nevertheless, these episodes generate extensive documentation which is testimony of the processes in almost real time. It is necessary to exploit this source typology in order to draw flood sketches when events far in time may lack a sufficiently rich database. This is particularly the case for the Valencia flash flood (October 1957), located in the lower Turia River basin (Eastern Spain). It left numerous pieces of hydro-geomorphic evidence, but its tracks were covered a short while after the flood. In any case, it remains part of a non-systematic legacy that has not yet been exploited, consisting of immediate aerial and oblique high resolution photography, pictures at street level, water marks and administrative records. Paradoxically, despite being considered a milestone in metropolitan territorial planning (the river was definitely diverted), an accurate reconstruction of the hydraulic behaviour was required from an integrated point of view. To this aim, the development of a GIS-Based Model enabled the utilisation of the above-mentioned materials. This non-conventional information was treated jointly from a new perspective. It provided database support through a vast amount of organised, structured and georeferenced information about the 1957 event. In a second stage, the GBM made it possible to characterise the Turia urban reach and interpret both the hydro-geomorphic (trenches along barrier beaches, erosion, deposition, etc.) and hydraulic (urban streams along the streets, flow directions, flood extent, levees breaks, overflows and inflows, etc.) processes mainly through photo-interpretation.

77 FR 58371 - Allegheny Hydro No. 8, L.P., Allegheny Hydro No. 9, L.P., and U.S. Bank National Association...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-20

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 3021-088] Allegheny Hydro No. 8, L.P., Allegheny Hydro No. 9, L.P., and U.S. Bank National Association Allegheny Hydro, LLC... 31, 2012, Allegheny Hydro No. 8, L.P., Allegheny Hydro No. 9, L.P., and U.S. Bank National...

The Impact of Infiltration Losses and Model Resolution on the Simulated Hydrometeorological Response of a Semi-Arid Catchment

NASA Astrophysics Data System (ADS)

Mitchell, M. F.; Goodrich, D. C.; Gochis, D. J.; Lahmers, T. M.

2017-12-01

In semi-arid environments with complex terrain, redistribution of moisture occurs through runoff, stream infiltration, and regional groundwater flow. In semi-arid regions, stream infiltration has been shown to account for 10-40% of total recharge in high runoff years. These processes can potentially significantly alter land-atmosphere interactions through changes in sensible and latent heat release. However, currently, their overall impact is still unclear as historical model simulations generally made use of a coarse grid resolution, where these smaller-scale processes were either parameterized or not accounted for. To improve our understanding on the importance of stream infiltration and our ability to represent them in a coupled land-atmosphere model, this study focuses on the Walnut Gulch Experimental Watershed (WGEW) and Long-Term Agro-ecosystem Research (LTAR) site, surrounding the city of Tombstone, AZ. High-resolution surface precipitation, meteorological forcing and distributed runoff measurements have been obtained in WGEW since the 1960s. These data will be used as input for the spatially distributed WRF-Hydro model, a spatially distributed hydrological model that uses the NOAH-MP land surface model. Recently, we have implemented an infiltration loss scheme to WRF-Hydro. We will present the performance of WRF-Hydro to account for stream infiltration by comparing model simulation with in-situ observations. More specifically, as the performance of the model simulations has been shown to depend on the used model grid resolution, in the current work results will present WRF-Hydro simulations obtained at different pixel resolution (10-1000m).

Spatiotemporal patterns of stable isotopes and hydrochemistry in springs and river flow of the upper Karkheh River Basin, Iran.

PubMed

Osati, Khaled; Koeniger, Paul; Salajegheh, Ali; Mahdavi, Mohammad; Chapi, Kamran; Malekian, Arash

2014-06-01

Karst springs of the Zagros Mountains contribute a significant amount to agricultural and human water demands of western and south-western Iran. For an adequate management of available water resources in semi-arid and arid regions, sufficient hydrological monitoring is needed, and hydro-chemical and isotope hydrological data provide important additional information. About 350 water samples were collected from precipitation, river water, and karst springs of the upper part of the Karkheh River Basin (20,895 km(2)) located between 33°35(') and 34°55(') North and 46°22(') and 49°10(') East with elevations ranging from 928 to 3563 m above sea level. Sampling was conducted in monthly time resolution from August 2011 to July 2012. All samples were analysed for hydro-chemical parameters (pH, electrical conductivity, and major ions) and stable isotopes (deuterium, oxygen-18). Isotope values of precipitation indicate a local meteoric water line (Zagros MWL δ(2)H=6.8 δ(18)O+10.1; R(2)=0.99) situated between the Mediterranean MWL and Global MWL. Spring and river water isotope values vary between-7.1 and-4.1 ‰, and-38 and-25 ‰ for δ(18)O and δ(2)H, respectively, responding to winter snowmelt and evaporation. This work implements stable isotopes and hydro-chemical information of springs and river water to understand hydrological and hydro-geological interrelations in karstic semi-arid areas and helps to improve the current water resources management practices of western Iran.

The Rhic Azimuth Quadrupole:. "perfect Liquid" or Gluonic Radiation?

NASA Astrophysics Data System (ADS)

Trainor, Thomas A.

Large elliptic flow at RHIC seems to indicate that ideal hydrodynamics provides a good description of Au-Au collisions, at least at the maximum RHIC energy. The medium formed has been interpreted as a nearly perfect (low-viscosity) liquid, and connections have been made to gravitation through string theory. Recently, claimed observations of large flow fluctuations comparable to participant eccentricity fluctuations seem to confirm the ideal hydro scenario. However, determination of the azimuth quadrupole with 2D angular autocorrelations, which accurately distinguish "flow" (quadrupole) from "nonflow" (minijets), contradicts conventional interpretations. Centrality trends may depend only on the initial parton geometry, and methods used to isolate flow fluctuations are sensitive instead mainly to minijet correlations. The results presented in this paper suggest that the azimuth quadrupole may be a manifestation of gluonic multipole radiation.

Basal friction evolution and crevasse distribution during the surge of Basin 3, Austfonna ice-cap - offline coupling between a continuum ice dynamic model and a discrete element model

NASA Astrophysics Data System (ADS)

Gong, Yongmei; Zwinger, Thomas; Åström, Jan; Gladstone, Rupert; Schellenberger, Thomas; Altena, Bas; Moore, John

2017-04-01

The outlet glacier at Basin 3, Austfonna ice-cap entered its active surge phase in autumn 2012. We assess the evolution of the basal friction during the surge through inverse modelling of basal friction coefficients using recent velocity observation from 2012 to 2014 in a continuum ice dynamic model Elmer/ice. The obtained basal friction coefficient distributions at different time instances are further used as a boundary condition in a discrete element model (HiDEM) that is capable of computing fracturing of ice. The inverted basal friction coefficient evolution shows a gradual 'unplugging' of the stagnant frontal area and northwards and inland expansion of the fast flowing region in the southern basin. The validation between the modeled crevasses distribution and the satellite observation in August 2013 shows a good agreement in shear zones inland and at the frontal area. Crevasse distributions of the summer before and after the glacier reached its maximum velocity in January 2013 (August 2012 and August 2014, respectively) are also evaluated. Previous studies suggest the triggering and development of the surge are linked to surface melt water penetrating through ice to form an efficient basal hydrology system thereby triggering a hydro- thermodynamic feedback. This preliminary offline coupling between a continuum ice dynamic model and a discrete element model will give a hint on future model development of linking supra-glacial to sub-glacial hydrology system.

Geo-Hydro Statistical Characterization of Preferential Flow and Transport Processes in Karst Groundwater Systems

NASA Astrophysics Data System (ADS)

Anaya, A. A.; Padilla, I. Y.; Macchiavelli, R. E.

2011-12-01

Karst groundwater systems are highly productive and provide an important fresh water resource for human development and ecological integrity. Their high productivity is often associated with conduit flow and high matrix permeability. The same characteristics that make these aquifers productive also make them highly vulnerable to contamination and a likely for contaminant exposure. Of particular interest are chlorinated organic contaminants and phthalates derived from industrial solvents and plastic by-products. These chemicals have been identified as potential precursors of pre-term birth, a leading cause of neonatal complications with a significant health and societal cost. The general objectives of this work are to: (1) develop fundamental knowledge and determine the processes controlling the release, mobility, persistence, and possible pathways of contaminants in karst groundwater systems, and (2) characterize transport processes in conduit and diffusion-dominated flow under base flow and storm flow conditions. The work presented herein focuses on the development of geo-hydro statistical tools to characterize flow and transport processes under different flow regimes. Multidimensional, laboratory-scale Geo-Hydrobed models were developed and tested for this purpose. The models consist of stainless-steel tanks containing karstified limestone blocks collected from the karst aquifer formation of northern Puerto Rico. The models a network of sampling wells to monitor flow, pressure, and solute concentrations temporally and spatially. Experimental work entailed making a series of point injections in wells while monitoring the hydraulic response in other wells. Statistical mixed models were applied to spatial probabilities of hydraulic response and weighted injected volume data, and were used to determinate the best spatial correlation structure to represent paths of preferential flow in the limestone units under different groundwater flow regimes. Preliminary testing of the karstified models show that the system can be used to represent the variable transport regime characterized by conduit and diffuses flow in the karst systems. Initial hydraulic characterization indicates a highly heterogeneous system resulting in large preferential flow components. Future works involve characterization of dual porosity system using conservative tracers, fate and transport experiments using phthalates and chlorinated solvents, geo-temporal statistical modeling, and the testing of "green" remediation technologies in karst groundwater. This work is supported by the U.S. Department of Energy, Savannah River (Grant Award No. DE-FG09-07SR22571), and the National Institute of Environmental Health Sciences (NIEHS, Grant Award No. P42ES017198).

Coupled Flow and Mechanics in Porous and Fractured Media*

NASA Astrophysics Data System (ADS)

Martinez, M. J.; Newell, P.; Bishop, J.

2012-12-01

Numerical models describing subsurface flow through deformable porous materials are important for understanding and enabling energy security and climate security. Some applications of current interest come from such diverse areas as geologic sequestration of anthropogenic CO2, hydro-fracturing for stimulation of hydrocarbon reservoirs, and modeling electrochemistry-induced swelling of fluid-filled porous electrodes. Induced stress fields in any of these applications can lead to structural failure and fracture. The ultimate goal of this research is to model evolving faults and fracture networks and flow within the networks while coupling to flow and mechanics within the intact porous structure. We report here on a new computational capability for coupling of multiphase porous flow with geomechanics including assessment of over-pressure-induced structural damage. The geomechanics is coupled to the flow via the variation in the fluid pore pressures, whereas the flow problem is coupled to mechanics by the concomitant material strains which alter the pore volume (porosity field) and hence the permeability field. For linear elastic solid mechanics a monolithic coupling strategy is utilized. For nonlinear elastic/plastic and fractured media, a segregated coupling is presented. To facilitate coupling with disparate flow and mechanics time scales, the coupling strategy allows for different time steps in the flow solve compared to the mechanics solve. If time steps are synchronized, the controller allows user-specified intra-time-step iterations. The iterative coupling is dynamically controlled based on a norm measuring the degree of variation in the deformed porosity. The model is applied for evaluation of the integrity of jointed caprock systems during CO2 sequestration operations. Creation or reactivation of joints can lead to enhanced pathways for leakage. Similarly, over-pressures can induce flow along faults. Fluid flow rates in fractures are strongly dependent on the effective hydraulic aperture, which is a non-linear function of effective normal stress. The dynamically evolving aperture field updates the effective, anisotropic permeability tensor, thus resulting in a highly coupled multiphysics problem. Two models of geomechanical damage are discussed: critical shear-slip criteria and a sub-grid joint model. Leakage rates through the caprock resulting from the joint model are compared to those assuming intact material, allowing a correlation between potential for leakage and injection rates/pressures, for various in-situ stratigraphies. *This material is based upon work supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001114. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energys National Nuclear Security Administration under Contract DE-AC04-94AL85000.

77 FR 37035 - Goose River Hydro, Inc.; Independence Hydro, LLC; Notice of Application for Transfer of License...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-20

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 2804-027] Goose River Hydro, Inc.; Independence Hydro, LLC; Notice of Application for Transfer of License, and Soliciting Comments and Motions to Intervene On June 6, 2012, Goose River Hydro, Inc. (transferor) and Independence Hydro...

76 FR 73612 - Lock Hydro Friends Fund XVIII; Upper Hydroelectric LLC; FFP Project 95 LLC; Riverbank Hydro No...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-29

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14261-000; 14268-000; 14277-000; 14281-000] Lock Hydro Friends Fund XVIII; Upper Hydroelectric LLC; FFP Project 95 LLC... Friends Fund XVIII (Lock Hydro), Upper Hydroelectric LLC (Upper Hydro), Riverbank Hydro No. 25 LLC...

76 FR 67175 - Riverbank Hydro No. 2 LLC, Lock Hydro Friends Fund XXXVI, Arkansas Electric Cooperative Corp...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-31

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14130-000; 14137-000; 14149-000] Riverbank Hydro No. 2 LLC, Lock Hydro Friends Fund XXXVI, Arkansas Electric Cooperative Corp... Lock Hydro Friends Fund XXXVI (Lock Hydro) and on April 11, 2011, Arkansas Electric Cooperative Corp...

Spatial connectivity, scaling, and temporal trajectories as emergent urban stormwater impacts

NASA Astrophysics Data System (ADS)

Jovanovic, T.; Gironas, J. A.; Hale, R. L.; Mejia, A.

2016-12-01

Urban watersheds are structurally complex systems comprised of multiple components (e.g., streets, pipes, ponds, vegetated swales, wetlands, riparian corridors, etc.). These multiple engineered components interact in unanticipated and nontrivial ways with topographic conditions, climate variability, land use/land cover changes, and the underlying eco-hydrogeomorphic dynamics. Such interactions can result in emergent urban stormwater impacts with cascading effects that can negatively influence the overall functioning of the urban watershed. For example, the interaction among many detention ponds has been shown, in some situations, to synchronize flow volumes and ultimately lead to downstream flow amplifications and increased pollutant mobilization. Additionally, interactions occur at multiple temporal and spatial scales requiring that urban stormwater dynamics be represented at the long-term temporal (decadal) and across spatial scales (from the single lot to the watershed scale). In this study, we develop and implement an event-based, high-resolution, network hydro-engineering model (NHEM), and demonstrate an approach to reconstruct the long-term regional infrastructure and land use/land cover conditions of an urban watershed. As the study area, we select an urban watershed in the metropolitan area of Scottsdale, Arizona. Using the reconstructed landscapes to drive the NHEM, we find that distinct surficial, hydrologic connectivity patterns result from the intersection of hydrologic processes, infrastructure, and land use/land cover arrangements. These spatial patters, in turn, exhibit scaling characteristics. For example, the scaling of urban watershed dispersion mechanisms shows altered scaling exponents with respect to pre-urban conditions. For example, the scaling exponent associated with geomorphic dispersion tends to increase for urban conditions, reflecting increased surficial path heterogeneity. Both the connectivity and scaling results can be used to delineate impact trajectories (i.e. the evolution of spatially referenced impacts over time). We find that the impact trajectories provide insight about the urban stormwater sustainability of watersheds as well as clues about the potential imprint of socio-environmental feedbacks in the evolutionary dynamics.

77 FR 28866 - Shelbyville Hydro LLC; Notice of Application Accepted for Filing and Soliciting Motions To...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-16

... the Commission's Web site http://www.ferc.gov/docs-filing/efiling.asp . Commenters can submit brief....gov/docs-filing/ecomment.asp . You must include your name and contact information at the end of your... with a flow of 130 to 1,500 cubic feet per second (cfs) at a net head of 33 to 77 feet; (6) an...

Hydro-meteorologic assessment of October 2015 extreme precipitation event on Santee Experimental Forest Watersheds, South Carolina

Treesearch

D.M. Amatya; C.A. Harrison; C.C. Trettin

2016-01-01

The extreme precipitation event on October 3-4, 2015, likely resulting from the convergence of a persistent deep easterly flow, the continuous supply of moisture, the terrain, and the circulation associated with Hurricane Joaquin off the eastern Atlantic Coast (http://cms.met.psu. edu/sref/severe/2015/04Oct2015.pdf) resulted in extreme and prolonged flooding in many...

76 FR 71959 - KC Hydro LLC of New Hampshire; Notice of Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-21

... shaft Kaplan turbine-generating unit with a total installed capacity of 0.84 MW; (5) a new 135-foot-long... outlet works; (4) a minimum flow turbine generator and a new 2,000-square-foot powerhouse containing one or two submersible or tubular-type turbine generators with a total installed capacity of 0.36 MW; (5...

NASA Propulsion Engineering Research Center, Volume 2

NASA Technical Reports Server (NTRS)

1994-01-01

This is the second volume in the 1994 annual report for the NASA Propulsion Engineering Research Center's Sixth Annual Symposium. This conference covered: (1) Combustors and Nozzles; (2) Turbomachinery Aero- and Hydro-dynamics; (3) On-board Propulsion systems; (4) Advanced Propulsion Applications; (5) Vaporization and Combustion; (6) Heat Transfer and Fluid Mechanics; and (7) Atomization and Sprays.

Multiscale wind cycles and current pulses at the Black Sea eastern boundary

NASA Astrophysics Data System (ADS)

Melnikov, Vasiliy; Moskalenko, Lidija; Piotoukh, Vladimir; Zatsepin, Andrey

2015-04-01

The goal of the research is to examine meteorological descriptive elements, sea-water properties, regional hydrodynamics and energy conversion fluxes in order to study sea responses to the local and far-field weather system. The Black Sea is situated in the chain of internal basins between the North Atlantic and Central Asia deserts in the marginal interaction zone and, accordingly, is under the influence of the Azores and Siberian anticyclones, Arctic cold-air surges and subtropical desert belt to the south. The analysis is based on the data of modern oceanographic measuring network "Hydro-physical Polygon" of the Institute of oceanology, using contact and remote sensing methods, weather stations around the Black Sea coasts, including long-term (1938-2014) measurements at the Gelendzhik weather station. Various satellite and Reanalysis databases are used. Currently, there are three long-time measuring moored stations (each contains ADCP and thermistor chain) and scanning profiling system "Akvalog". Hydrological sections and field surveys using towed ADCP and CTD are performed on a regular basis. The data are accumulated in the coastal archive which allows calibration of satellite measurements and testing results of numerical modeling. Data processing includes data sets preparation, editing, time series statistical calculations using histograms, progressive vector diagrams, traditional Fourier spectral analysis including auto- and cross spectra, auto and mutual wavelet diagrams, moving spectrograms, vector data methods using rotary components, spectral invariants, empirical modes, hodograph and pre-specified spectrum representations on the basis of stochastic models with imposed dynamical assumptions. Due to the intermittent nature of the time rows, spectral representation is misleading, often. In order to identify the individual evolving dynamical phenomenon, typical background (seasonal) three-dimensional structures of the hydrological field, as well as quantified anomalies, associated with different frequency components of variability, such as sub-meso-scale eddies, marginal shelf waves, inertial oscillations, diurnal, semi-diurnal and short-period internal waves, long surface waves, were estimated. Based on estimates of the statistical relationships between the different parameters of hydro-meteorological system, including meteorological elements, sea level, sea temperature and flow fields, space/time scales of the observed fields variability were estimated. Several new features of the physical mechanisms of multiscale hydro-physical processes in the shelf zone of the Black Sea, have been revealed. In particular, it is shown, that there are wind self-similar cycles at different time scales, each cycle being consisted of a pair of northeast and then southeast winds, which corresponds to the alternative influences of the Azores and Siberian highs(in winter). In the range of decadal (10 years) scale and in macro space view, long-term wind cycles support basic Black Sea circulation(Rim Current).Wind cycles with a time scale of about 20 days give rise to distinct upwellings, appeared with the same frequency. Along with each upwelling, radical hydrological restructuring of the stratification is accompanied by intense advection with high velocities(up to 1 m/s). Kinetic energy is dominated by alongshore currents, the direction being reversed periodically. The vertical structure of currents is rather complicated. When the current speed exceeds some threshold value, the flow gives rise to relaxation oscillations with a period of about 24 hours with counterclockwise velocity vector rotation. All the above mentioned events and current pulses cause significant variations of air-sea fluxes. This research was jointly supported by Ministry of Education of the RF (Agreement №14.604.21.0044), Russian Academy of Sciences(Program No 23), RFBR grant 14-05-00159,contract No 10/2013 RGS-RFBR.

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Hydro-geomechanical behaviour of gas-hydrate bearing soils during gas production through depressurization and CO2 injection

NASA Astrophysics Data System (ADS)

Deusner, C.; Gupta, S.; Kossel, E.; Bigalke, N.; Haeckel, M.

2015-12-01

Results from recent field trials suggest that natural gas could be produced from marine gas hydrate reservoirs at compatible yields and rates. It appears, from a current perspective, that gas production would essentially be based on depressurization and, when facing suitable conditions, be assisted by local thermal stimulation or gas hydrate conversion after injection of CO2-rich fluids. Both field trials, onshore in the Alaska permafrost and in the Nankai Trough offshore Japan, were accompanied by different technical issues, the most striking problems resulting from un-predicted geomechanical behaviour, sediment destabilization and catastrophic sand production. So far, there is a lack of experimental data which could help to understand relevant mechanisms and triggers for potential soil failure in gas hydrate production, to guide model development for simulation of soil behaviour in large-scale production, and to identify processes which drive or, further, mitigate sand production. We use high-pressure flow-through systems in combination with different online and in situ monitoring tools (e.g. Raman microscopy, MRI) to simulate relevant gas hydrate production scenarios. Key components for soil mechanical studies are triaxial systems with ERT (Electric resistivity tomography) and high-resolution local strain analysis. Sand production control and management is studied in a novel hollow-cylinder-type triaxial setup with a miniaturized borehole which allows fluid and particle transport at different fluid injection and flow conditions. Further, the development of a large-scale high-pressure flow-through triaxial test system equipped with μ-CT is ongoing. We will present results from high-pressure flow-through experiments on gas production through depressurization and injection of CO2-rich fluids. Experimental data are used to develop and parametrize numerical models which can simulate coupled process dynamics during gas-hydrate formation and gas production.

Experiments with Interaction between the National Water Model and the Reservoir System Simulation Model: A Case Study of Russian River Basin

NASA Astrophysics Data System (ADS)

Kim, J.; Johnson, L.; Cifelli, R.; Chandra, C. V.; Gochis, D.; McCreight, J. L.; Yates, D. N.; Read, L.; Flowers, T.; Cosgrove, B.

2017-12-01

NOAA National Water Center (NWC) in partnership with the National Centers for Environmental Prediction (NCEP), the National Center for Atmospheric Research (NCAR) and other academic partners have produced operational hydrologic predictions for the nation using a new National Water Model (NWM) that is based on the community WRF-Hydro modeling system since the summer of 2016 (Gochis et al., 2015). The NWM produces a variety of hydrologic analysis and prediction products, including gridded fields of soil moisture, snowpack, shallow groundwater levels, inundated area depths, evapotranspiration as well as estimates of river flow and velocity for approximately 2.7 million river reaches. Also included in the NWM are representations for more than 1,200 reservoirs which are linked into the national channel network defined by the USGS NHDPlusv2.0 hydrography dataset. Despite the unprecedented spatial and temporal coverage of the NWM, many known deficiencies exist, including the representation of lakes and reservoirs. This study addresses the implementation of a reservoir assimilation scheme through coupling of a reservoir simulation model to represent the influence of managed flows. We examine the use of the reservoir operations to dynamically update lake/reservoir storage volume states, characterize flow characteristics of river reaches flowing into and out of lakes and reservoirs, and incorporate enhanced reservoir operating rules for the reservoir model options within the NWM. Model experiments focus on a pilot reservoir domain-Lake Mendocino, CA, and its contributing watershed, the East Fork Russian River. This reservoir is modeled using United States Army Corps of Engineers (USACE) HEC-ResSim developed for application to examine forecast informed reservoir operations (FIRO) in the Russian River basin.

Coupled Thermo-Hydro-Mechanical Numerical Framework for Simulating Unconventional Formations

NASA Astrophysics Data System (ADS)

Garipov, T. T.; White, J. A.; Lapene, A.; Tchelepi, H.

2016-12-01

Unconventional deposits are found in all world oil provinces. Modeling these systems is challenging, however, due to complex thermo-hydro-mechanical processes that govern their behavior. As a motivating example, we consider in situ thermal processing of oil shale deposits. When oil shale is heated to sufficient temperatures, kerogen can be converted to oil and gas products over a relatively short timespan. This phase change dramatically impact both the mechanical and hydrologic properties of the rock, leading to strongly coupled THMC interactions. Here, we present a numerical framework for simulating tightly-coupled chemistry, geomechanics, and multiphase flow within a reservoir simulator (the AD-GPRS General Purpose Research Simulator). We model changes in constitutive behavior of the rock using a thermoplasticity model that accounts for microstructural evolution. The multi-component, multiphase flow and transport processes of both mass and heat are modeled at the macroscopic (e.g., Darcy) scale. The phase compositions and properties are described by a cubic equation of state; Arrhenius-type chemical reactions are used to represent kerogen conversion. The system of partial differential equations is discretized using a combination of finite-volumes and finite-elements, respectively, for the flow and mechanics problems. Fully implicit and sequentially implicit method are used to solve resulting nonlinear problem. The proposed framework is verified against available analytical and numerical benchmark cases. We demonstrate the efficiency, performance, and capabilities of the proposed simulation framework by analyzing near well deformation in an oil shale formation.

Benthic macroinvertebrates response to water management in a lowland river: effects of hydro-power vs irrigation off-stream diversions.

PubMed

Salmaso, Francesca; Crosa, Giuseppe; Espa, Paolo; Gentili, Gaetano; Quadroni, Silvia; Zaccara, Serena

2017-12-20

An eco-hydraulic survey of the highly regulated Adda River (northern Italy) was carried out to highlight the ecological implications of the current water management, including minimum flows (MFs) set as environmental protection measures. Macroinvertebrates, flows, and other main physico-chemical parameters were monitored from 2010 to 2012 at seven sites located in two river reaches characterized by different water abstraction schemes. In the upper part of the river, water is mainly diverted for hydro-power, and, in water-depleted reaches, discharges equalled MF for more than 100 days y -1 , mainly during winter. In the downstream river reach, where irrigation use prevails, discharges were on average three times higher than in the upper part of the river, and flow values similar to MF were detected only for short periods during summer. The two resulting streamflow patterns seem to have shaped different benthic communities, superimposing to the natural downstream variation. The upper reach is characterized by univoltine taxa, while the lower reach by multivoltine taxa adapted to a more disturbed environment. Chironomidae, a well-known tolerant benthic family, dominated at a site affected by point-source pollution, which turned out to be another determinant of macroinvertebrate community. Despite these differences among sites in the benthic community structure, the current water management seems to allow, for all of the investigated river sites, the achievement of the good ecological status as defined by the local law set in accomplishment of the Water Framework Directive.

Design and Construction of a Hydroturbine Test Facility

NASA Astrophysics Data System (ADS)

Ayli, Ece; Kavurmaci, Berat; Cetinturk, Huseyin; Kaplan, Alper; Celebioglu, Kutay; Aradag, Selin; Tascioglu, Yigit; ETU Hydro Research Center Team

2014-11-01

Hydropower is one of the clean, renewable, flexible and efficient energy resources. Most of the developing countries invest on this cost-effective energy source. Hydroturbines for hydroelectric power plants are tailor-made. Each turbine is designed and constructed according to the properties, namely the head and flow rate values of the specific water source. Therefore, a center (ETU Hydro-Center for Hydro Energy Research) for the design, manufacturing and performance tests of hydraulic turbines is established at TOBB University of Economics and Technology to promote research in this area. CFD aided hydraulic and structural design, geometry optimization, manufacturing and performance tests of hydraulic turbines are the areas of expertise of this center. In this paper, technical details of the design and construction of this one of a kind test facility in Turkey, is explained. All the necessary standards of IEC (International Electrotechnical Commission) are met since the test facility will act as a certificated test center for hydraulic turbines.

Recent advances in the multimodel hydrologic ensemble forecasting using the HydroProg system in the Nysa Klodzka river basin (southwestern Poland)

NASA Astrophysics Data System (ADS)

Niedzielski, Tomasz; Mizinski, Bartlomiej; Swierczynska-Chlasciak, Malgorzata

2017-04-01

The HydroProg system, the real-time multimodel hydrologic ensemble system elaborated at the University of Wroclaw (Poland) in frame of the research grant no. 2011/01/D/ST10/04171 financed by National Science Centre of Poland, has been experimentally launched in 2013 in the Nysa Klodzka river basin (southwestern Poland). Since that time the system has been working operationally to provide water level predictions in real time. At present, depending on a hydrologic gauge, up to eight hydrologic models are run. They are data- and physically-based solutions, with the majority of them being the data-based ones. The paper aims to report on the performance of the implementation of the HydroProg system for the basin in question. We focus on several high flows episodes and discuss the skills of the individual models in forecasting them. In addition, we present the performance of the multimodel ensemble solution. We also introduce a new prognosis which is determined in the following way: for a given lead time we select the most skillful prediction (from the set of all individual models running at a given gauge and their multimodel ensemble) using the performance statistics computed operationally in real time as a function of lead time.

The vulnerability and resilience of a city's water footprint: The case of Flagstaff, Arizona, USA

NASA Astrophysics Data System (ADS)

Rushforth, Richard R.; Ruddell, Benjamin L.

2016-04-01

Research has yet to operationalize water footprint information for urban water policy and planning to reduce vulnerability and increase resilience to water scarcity. Using a county-level database of the U.S. hydro-economy, NWED, we spatially mapped and analyzed the Water Footprint of Flagstaff, Arizona, a small city. Virtual water inflow and outflow networks were developed using the flow of commodities into and out of the city. The power law distribution of virtual water trade volume between Flagstaff and its county trading partners broke at a spatial distance of roughly 2000 km. Most large trading partners are within this geographical distance, and this distance is an objective definition for Flagstaff's zone of indirect hydro-economic influence—that is, its water resource hinterland. Metrics were developed to measure Flagstaff's reliance on virtual water resources, versus direct use of local physical water resources. Flagstaff's reliance on external water supplies via virtual water trade increases both its hydro-economic resilience and vulnerability to water scarcity. These methods empower city managers to operationalize the city's Water Footprint information to reduce vulnerability, increase resilience, and optimally balance the allocation of local physical water supplies with the outsourcing of some water uses via the virtual water supply chain.

Patch-based Adaptive Mesh Refinement for Multimaterial Hydrodynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lomov, I; Pember, R; Greenough, J

2005-10-18

We present a patch-based direct Eulerian adaptive mesh refinement (AMR) algorithm for modeling real equation-of-state, multimaterial compressible flow with strength. Our approach to AMR uses a hierarchical, structured grid approach first developed by (Berger and Oliger 1984), (Berger and Oliger 1984). The grid structure is dynamic in time and is composed of nested uniform rectangular grids of varying resolution. The integration scheme on the grid hierarchy is a recursive procedure in which the coarse grids are advanced, then the fine grids are advanced multiple steps to reach the same time, and finally the coarse and fine grids are synchronized tomore » remove conservation errors during the separate advances. The methodology presented here is based on a single grid algorithm developed for multimaterial gas dynamics by (Colella et al. 1993), refined by(Greenough et al. 1995), and extended to the solution of solid mechanics problems with significant strength by (Lomov and Rubin 2003). The single grid algorithm uses a second-order Godunov scheme with an approximate single fluid Riemann solver and a volume-of-fluid treatment of material interfaces. The method also uses a non-conservative treatment of the deformation tensor and an acoustic approximation for shear waves in the Riemann solver. This departure from a strict application of the higher-order Godunov methodology to the equation of solid mechanics is justified due to the fact that highly nonlinear behavior of shear stresses is rare. This algorithm is implemented in two codes, Geodyn and Raptor, the latter of which is a coupled rad-hydro code. The present discussion will be solely concerned with hydrodynamics modeling. Results from a number of simulations for flows with and without strength will be presented.« less

Climatic change impacts on water balance of the Upper Jordan River

NASA Astrophysics Data System (ADS)

Heckl, A.; Kunstmann, H.

2009-04-01

The Eastern Mediterranean and Near East (EM/NE) is an extremely water scarce environment. It is expected that problems will increase due to climate change and population growth. The impact of climate change on water availability in EM/NE and in particular the Jordan River catchment is investigated in this study. Focus is set on the Upper Jordan River catchment (UJC) as it provides 1/3rd of freshwater resources in Israel and Palestine. It is a hydro-geologically extremely complex region with karstic groundwater flow and an orography with steep gradients. The methods used are high resolution coupled regional climate - hydrology simulations. Two IPCC scenarios (A2 and B2) of the global climate model ECHAM4 have been dynamically downscaled using the non-hydrostatic meteorological model MM5 in two nesting steps with resolutions of 54x54 km2 and 18x18 km2 for the period 1961-2099, whereby the time slice 1961-1989 represents the current climate. The meteorological fields are used to drive the physically based hydrological model WaSiM applied to the UJC. The hydrological model computes in detail the surface and subsurface water flow and water balance in a horizontal resolution of 450 x 450 m2 and dynamically couples to a 2-dim numerical groundwater model. Parameters like surface runoff, groundwater recharge, soil moisture and evapotranspiration can be extracted. Results show in both scenarios increasing yearly mean temperatures up to 4-5 K until 2099 and decreasing yearly precipitation amounts up to 25% (scenario A2). The effect on the water balance of the UJC are reduced discharge and groundwater recharge, increased evaporation and reduction of snow cover in the mountains which usually serves as an important freshwater reservoir for the summer discharge.

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Catchment organisation, free energy dynamics and network control on critical zone water flows

NASA Astrophysics Data System (ADS)

Zehe, E.; Ehret, U.; Kleidon, A.; Jackisch, C.; Scherer, U.; Blume, T.

2012-04-01

From a functional point of view the catchment system is compiled by patterns of permeable and less permeable textural elements - soils and mother rock. Theses textural elements provide a mechanical stabile matrix for growth of terrestrial biota and soil formation. They furthermore organize subsurface storage of water against gravity, dissolved nutrients and heat. Storage against gravity is only possible because water acts as wetting fluid and is thus attracted by capillary forces in the pores space. Capillarity increases non-linearly with decreasing pore size and is zero at local saturation. The pore size distribution of a soil is thus characteristic of its capability to store water against losses such as drainage, evaporation and root extraction and at the same time a fingerprint of the work that has been performed by physical, chemical and biological processes to weather solid mother rock and form a soil. A strong spatial covariance of soil hydraulic properties within the same soil type is due to a fingerprint of strong spatial organization at small scales. Spatial organization at the hillslope scale implies the existence of a typical soil catena i.e. that hillslopes exhibit the same/ downslope sequence of different soils types. Textural storage elements are separated by strikingly self-similar network like structures, we name them flow structures. These flow structures are created in a self-reinforcing manner by work performed either by biota like earth worms and plant roots or by dissipative processes such as soil cracking and water/fluvial erosion. Regardless of their different origin connected flow structures exhibit a highly similar functioning and similar characteristics: they allow for high mass flows at small driving potential gradients because specific flow resistance along the network is continuously very small. This implies temporal stability even during small extremes, due to the small amount of local momentum dissipation per unit mass flow, as well as that these flow structures organize and dominate flows of water, dissolved matter and sediments during rainfall driven conditions at various scales: - Surface connected vertical flow structures of anecic worm burrows or soil cracks organize and dominated vertical flows at the plot scale - this is usually referred to as preferential flow; - Rill networks at the soil surface organise and dominate hillslope scale overland flow response and sediment yields; - Subsurface pipe networks at the bedrock interface organize and dominate hillslope scale lateral subsurface water and tracer flows; - The river net organizes and dominates flows of water, dissolved matter and sediments to the catchment outlet and finally across continental gradients to the sea. Fundamental progress with respect to the parameterization of hydrological models, subscale flow networks and to understand the adaptation of hydro-geo ecosystems to change could be achieved by discovering principles that govern the organization of catchments flow networks in particular at least during steady state conditions. This insight has inspired various scientists to suggest principles for organization of ecosystems, landscapes and flow networks; as Bejans constructural law, Minimum Energy Expenditure , Maximum Entropy Production. In line with these studies we suggest that a thermodynamic/energetic treatment of the catchment is might be a key for understanding the underlying principles that govern organisation of flow and transport. Our approach is to employ a) physically based hydrological model that address at least all the relevant hydrological processes in the critical zone in a coupled way, behavioural representations of the observed organisation of flow structures and textural elements, that are consistent with observations in two well investigated research catchments and have been tested against distributed observations of soil moisture and catchment scale discharge; to simulate the full concert of hydrological processes using the behavioural system architecture and small perturbations and compare them with respect to their efficiency to dissipate free energy which is equivalent to produce entropy. The study will present the underlying theory and discuss simulation results with respect to the following core hypotheses: H1: A macro scale configuration of a hydro-geo-ecosystem, is in stationary non equilibrium closer to a functional optimum as other possible configurations, if it "dissipates" more of the available free energy to maintain the stationary cycles that redistribute and export mass and energy within/from the system. This implies (I1) that the system approaches faster a dynamic equilibrium state characterised by a minimum in free energy, and less free energy from persistent gradients is available to perform work in the system. H2: Macroscopically connected flow networks enhance redistribution of mass against macroscale gradients and thus dissipation of free energy, because they minimise local energy dissipation per unit mass flow along the flow path. This implies (I2) mechanic stability of the flow network, of the textural storage elements and thus of the entire system against frequent disturbances under stationary conditions.

MagIC: Fluid dynamics in a spherical shell simulator

NASA Astrophysics Data System (ADS)

Wicht, J.; Gastine, T.; Barik, A.; Putigny, B.; Yadav, R.; Duarte, L.; Dintrans, B.

2017-09-01

MagIC simulates fluid dynamics in a spherical shell. It solves for the Navier-Stokes equation including Coriolis force, optionally coupled with an induction equation for Magneto-Hydro Dynamics (MHD), a temperature (or entropy) equation and an equation for chemical composition under both the anelastic and the Boussinesq approximations. MagIC uses either Chebyshev polynomials or finite differences in the radial direction and spherical harmonic decomposition in the azimuthal and latitudinal directions. The time-stepping scheme relies on a semi-implicit Crank-Nicolson for the linear terms of the MHD equations and a Adams-Bashforth scheme for the non-linear terms and the Coriolis force.

Evaluation of uncertainty in capturing the spatial variability and magnitudes of extreme hydrological events for the uMngeni catchment, South Africa

NASA Astrophysics Data System (ADS)

Kusangaya, Samuel; Warburton Toucher, Michele L.; van Garderen, Emma Archer

2018-02-01

Downscaled General Circulation Models (GCMs) output are used to forecast climate change and provide information used as input for hydrological modelling. Given that our understanding of climate change points towards an increasing frequency, timing and intensity of extreme hydrological events, there is therefore the need to assess the ability of downscaled GCMs to capture these extreme hydrological events. Extreme hydrological events play a significant role in regulating the structure and function of rivers and associated ecosystems. In this study, the Indicators of Hydrologic Alteration (IHA) method was adapted to assess the ability of simulated streamflow (using downscaled GCMs (dGCMs)) in capturing extreme river dynamics (high and low flows), as compared to streamflow simulated using historical climate data from 1960 to 2000. The ACRU hydrological model was used for simulating streamflow for the 13 water management units of the uMngeni Catchment, South Africa. Statistically downscaled climate models obtained from the Climate System Analysis Group at the University of Cape Town were used as input for the ACRU Model. Results indicated that, high flows and extreme high flows (one in ten year high flows/large flood events) were poorly represented both in terms of timing, frequency and magnitude. Simulated streamflow using dGCMs data also captures more low flows and extreme low flows (one in ten year lowest flows) than that captured in streamflow simulated using historical climate data. The overall conclusion was that although dGCMs output can reasonably be used to simulate overall streamflow, it performs poorly when simulating extreme high and low flows. Streamflow simulation from dGCMs must thus be used with caution in hydrological applications, particularly for design hydrology, as extreme high and low flows are still poorly represented. This, arguably calls for the further improvement of downscaling techniques in order to generate climate data more relevant and useful for hydrological applications such as in design hydrology. Nevertheless, the availability of downscaled climatic output provide the potential of exploring climate model uncertainties in different hydro climatic regions at local scales where forcing data is often less accessible but more accurate at finer spatial scales and with adequate spatial detail.

Hydrodynamics of concordant and discordant fixed bed open-channel confluences

NASA Astrophysics Data System (ADS)

Birjukova Canelas, Olga; Lage Ferreira, Rui Miguel; Heleno Cardoso, António

2017-04-01

The detailed characterization of the flow field in river confluences constitutes a relevant step towards the understanding of the hydro-morpho-dynamics of these key zones of the fluvial system. With a few exceptions, existing works on this topic covered concordant bed scenarios, meaning that both confluent channels had the same elevation. This laboratory study aims to contribute to a detailed three-dimensional characterization of the flow field at a fixed bed confluence, as well as to shed light on how bed elevation discordance modifies the flow patterns of the converging flows. While the junction angle and the discharge ratio were kept fixed, two scenarios were studied on the basis of detailed water level and 3D ADV measurements at the denser mesh ever. The internal flow structure of the concordant bed scenario mostly complied with the classical conceptual models. A relevant difference concerns the size of the stagnation zone, much smaller close to the bed of the discordant bed confluence. A more significant difference is a horizontal flow structure, not previously identified in the literature, characterized by strong streamwise mean vorticity and strong secondary motion. It is observed for the discordant bed case, occurring along the inner wall of the main channel and downstream the junction corner. This structure is spatially well-correlated to a pronounced imbalance of cross-stream and vertical normal Reynolds stresses. This highlights the role of Reynolds stress anisotropy (RSA) that is generated in the shear layers than accompany the entrance of the tributary flow. Since this structure is not present in the concordant case, where RSA is also evident, it is argued that convective effects should also play a role in its formation, presumably due to deflection of the flow in the main channel by the tributary. The newly identified secondary motion should, thus, be a combination of Prandtĺs second kind and Prandtĺs first kind of secondary flow. The relative importance of each generating mechanism is still under investigation. Acknowledgements This research as partially supported by Portuguese and European funds, within programs COMPETE2020 and PORL-FEDER, through project PTDC/ECM-HID/6387/2014 granted by the National Foundation for Science and Technology (FCT).

Building an ensemble of climate scenarios for decision-making in hydrology: benefits, pitfalls and uncertainties

NASA Astrophysics Data System (ADS)

Braun, Marco; Chaumont, Diane

2013-04-01

Using climate model output to explore climate change impacts on hydrology requires several considerations, choices and methods in the post treatment of the datasets. In the effort of producing a comprehensive data base of climate change scenarios for over 300 watersheds in the Canadian province of Québec, a selection of state of the art procedures were applied to an ensemble comprising 87 climate simulations. The climate data ensemble is based on global climate simulations from the Coupled Model Intercomparison Project - Phase 3 (CMIP3) and regional climate simulations from the North American Regional Climate Change Assessment Program (NARCCAP) and operational simulations produced at Ouranos. Information on the response of hydrological systems to changing climate conditions can be derived by linking climate simulations with hydrological models. However, the direct use of raw climate model output variables as drivers for hydrological models is limited by issues such as spatial resolution and the calibration of hydro models with observations. Methods for downscaling and bias correcting the data are required to achieve seamless integration of climate simulations with hydro models. The effects on the results of four different approaches to data post processing were explored and compared. We present the lessons learned from building the largest data base yet for multiple stakeholders in the hydro power and water management sector in Québec putting an emphasis on the benefits and pitfalls in choosing simulations, extracting the data, performing bias corrections and documenting the results. A discussion of the sources and significance of uncertainties in the data will also be included. The climatological data base was subsequently used by the state owned hydro power company Hydro-Québec and the Centre d'expertise hydrique du Québec (CEHQ), the provincial water authority, to simulate future stream flows and analyse the impacts on hydrological indicators. While this submission focuses on the production of climatic scenarios for application in hydrology, the submission « The (cQ)2 project: assessing watershed scale hydrological changes for the province of Québec at the 2050 horizon, a collaborative framework » by Catherine Guay describes how Hydro-Québec and CEHQ put the data into use.

Quantifying Barotrauma Risk to Juvenile Fish during Hydro-turbine Passage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richmond, Marshall C.; Serkowski, John A.; Ebner, Laurie L.

2014-03-15

We introduce a method for hydro turbine biological performance assessment (BioPA) to bridge the gap between field and laboratory studies on fish injury and turbine engineering design. Using this method, a suite of biological performance indicators is computed based on simulated data from a computational fluid dynamics (CFD) model of a proposed hydro turbine design. Each performance indicator is a measure of the probability of exposure to a certain dose of an injury mechanism. If the relationship between the dose of an injury mechanism (stressor) and frequency of injury (dose-response) is known from laboratory or field studies, the likelihood ofmore » fish injury for a turbine design can be computed from the performance indicator. By comparing the values of the indicators from various turbine designs, engineers and biologists can identify the more-promising designs and operating conditions to minimize hydraulic conditions hazardous to passing fish. In this paper, the BioPA method is applied to estimate barotrauma induced mortal injury rates for Chinook salmon exposed to rapid pressure changes in Kaplan-type hydro turbines. Following the description of the general method, application of the BioPA to estimate the probability of mortal injury from exposure to rapid decompression is illustrated using a Kaplan hydro turbine at the John Day Dam on the Columbia River in the Pacific Northwest region of the USA. The estimated rates of mortal injury increased from 0.3% to 1.7% as discharge through the turbine increased from 334 to 564 m3/s for fish assumed to be acclimated to a depth of 5 m. The majority of pressure nadirs occurred immediately below the runner blades, with the lowest values in the gap at the blade tips and just below the leading edge of the blades. Such information can help engineers focus on problem areas when designing new turbine runners to be more fish-friendly than existing units.« less

75 FR 17706 - FPL Energy Maine Hydro LLC, Complainant v. Great Lakes Hydro America LLC Rumford Falls Hydro LLC...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL10-53-000] FPL Energy Maine Hydro LLC, Complainant v. Great Lakes Hydro America LLC Rumford Falls Hydro LLC, Respondents; Notice of Complaint March 29, 2010. Take notice that on March 26, 2010, pursuant to section 206 of the Federal Energy Regulatory Commission's (Commission...

77 FR 13317 - Notice Announcing Filing Priority for Preliminary Permit Applications: Lock+ Hydro Friends Fund...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-06

... Applications: Lock+ Hydro Friends Fund VIII; FFP Project 92, LLC; Riverbank Hydro No. 24, LLC On February 28.... 14276-000. 2. Riverbank Hydro No. 24, LLC: Project No. 14280-000. 3. Lock+ Hydro Friends Fund VIII...

Influence of dynamic coupled hydro-bio-mechanical processes on response of municipal solid waste and liner system in bioreactor landfills.

PubMed

Reddy, Krishna R; Kumar, Girish; Giri, Rajiv K

2017-05-01

A two-dimensional (2-D) mathematical model is presented to predict the response of municipal solid waste (MSW) of conventional as well as bioreactor landfills undergoing coupled hydro-bio-mechanical processes. The newly developed and validated 2-D coupled mathematical modeling framework combines and simultaneously solves a two-phase flow model based on the unsaturated Richard's equation, a plain-strain formulation of Mohr-Coulomb mechanical model and first-order decay kinetics biodegradation model. The performance of both conventional and bioreactor landfill was investigated holistically, by evaluating the mechanical settlement, extent of waste degradation with subsequent changes in geotechnical properties, landfill slope stability, and in-plane shear behavior (shear stress-displacement) of composite liner system and final cover system. It is concluded that for the given specific conditions considered, bioreactor landfill attained an overall stabilization after a continuous leachate injection of 16years, whereas the stabilization was observed after around 50years of post-closure in conventional landfills, with a total vertical strain of 36% and 37% for bioreactor and conventional landfills, respectively. The significant changes in landfill settlement, the extent of MSW degradation, MSW geotechnical properties, along with their influence on the in-plane shear response of composite liner and final cover system, between the conventional and bioreactor landfills, observed using the mathematical model proposed in this study, corroborates the importance of considering coupled hydro-bio-mechanical processes while designing and predicting the performance of engineered bioreactor landfills. The study underscores the importance of considering the effect of coupled processes while examining the stability and integrity of the liner and cover systems, which form the integral components of a landfill. Moreover, the spatial and temporal variations in the landfill settlement, the stability of landfill slope under pressurized leachate injection conditions and the rapid changes in the MSW properties with degradation emphasizes the complexity of the bioreactor landfill system and the need for understanding the interrelated processes to design and operate stable and effective bioreactor landfills. A detailed discussion on the results obtained from the numerical simulations along with limitations and key challenges in this study are also presented. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estuarine abandoned channel sedimentation rates record peak fluvial discharge magnitudes

NASA Astrophysics Data System (ADS)

Gray, A. B.; Pasternack, G. B.; Watson, E. B.

2018-04-01

Fluvial sediment deposits can provide useful records of integrated watershed expressions including flood event magnitudes. However, floodplain and estuarine sediment deposits evolve through the interaction of watershed/marine sediment supply and transport characteristics with the local depositional environment. Thus extraction of watershed scale signals depends upon accounting for local scale effects on sediment deposition rates and character. This study presents an examination of the balance of fluvial sediment dynamics and local scale hydro-geomorphic controls on alluviation of an abandoned channel in the Salinas River Lagoon, CA. A set of three sediment cores contained discrete flood deposits that corresponded to the largest flood events over the period of accretion from 1969 to 2007. Sedimentation rates scaled with peak flood discharge and event scale sediment flux, but were not influenced by longer scale hydro-meteorological activities such as annual precipitation and water yield. Furthermore, the particle size distributions of flood deposits showed no relationship to event magnitudes. Both the responsiveness of sedimentation and unresponsiveness of particle size distributions to hydro-sedimentological event magnitudes appear to be controlled by aspects of local geomorphology that influence the connectivity of the abandoned channel to the Salinas River mainstem. Well-developed upstream plug bar formation precluded the entrainment of coarser bedload into the abandoned channel, while Salinas River mouth conditions (open/closed) in conjunction with tidal and storm surge conditions may play a role in influencing the delivery of coarser suspended load fractions. Channel adjacent sediment deposition can be valuable records of hydro-meteorological and sedimentological regimes, but local depositional settings may dominate the character of short term (interdecadal) signatures.

75 FR 14437 - North Eastern Wisconsin Hydro Inc. (N.E.W. Hydro); Notice of Intent To File License Application...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-25

... Wisconsin Hydro Inc. (N.E.W. Hydro); Notice of Intent To File License Application, Filing of Pre-Application..., Inc. (N.E.W. Hydro) e. Name of Project: Menominee/Park Mill Hydroelectric Project. f. Location: The..., (202) 502-6156 or by e-mail at [email protected] . j. N.E.W. Hydro filed its request to use the...

A remark on the sign change of the four-particle azimuthal cumulant in small systems

NASA Astrophysics Data System (ADS)

Bzdak, Adam; Ma, Guo-Liang

2018-06-01

The azimuthal cumulants, c2 { 2 } and c2 { 4 }, originating from the global conservation of transverse momentum in the presence of hydro-like elliptic flow are calculated. We observe the sign change of c2 { 4 } for small number of produced particles. This is in a qualitative agreement with the recent ATLAS measurement of multi-particle azimuthal correlations with the subevent cumulant method.

Freshwater Choices in China: Options That Will Impact South and Southeast Asia

DTIC Science & Technology

2014-12-04

engineering infrastructure upstream on shared international river basins within its borders, and will be able to effectively use the threat of...constructing hydro-engineering infrastructure upstream on shared international river basins within its borders, and will be able to effectively use the...international river basins within its borders, China will be able to effectively use the threat of restricting freshwater flows as a political weapon to

HydroApps: An R package for statistical simulation to use in regional analysis

NASA Astrophysics Data System (ADS)

Ganora, D.

2013-12-01

The HydroApps package is a newborn R extension initially developed to support the use of a recent model for flood frequency estimation developed for applications in Northwestern Italy; it also contains some general tools for regional analyses and can be easily extended to include other statistical models. The package is currently at an experimental level of development. The HydroApps is a corollary of the SSEM project for regional flood frequency analysis, although it was developed independently to support various instances of regional analyses. Its aim is to provide a basis for interplay between statistical simulation and practical operational use. In particular, the main module of the package deals with the building of the confidence bands of flood frequency curves expressed by means of their L-moments. Other functions include pre-processing and visualization of hydrologic time series, analysis of the optimal design-flood under uncertainty, but also tools useful in water resources management for the estimation of flow duration curves and their sensitivity to water withdrawals. Particular attention is devoted to the code granularity, i.e. the level of detail and aggregation of the code: a greater detail means more low-level functions, which entails more flexibility but reduces the ease of use for practical use. A balance between detail and simplicity is necessary and can be resolved with appropriate wrapping functions and specific help pages for each working block. From a more general viewpoint, the package has not really and user-friendly interface, but runs on multiple operating systems and it's easy to update, as many other open-source projects., The HydroApps functions and their features are reported in order to share ideas and materials to improve the ';technological' and information transfer between scientist communities and final users like policy makers.

An objective and parsimonious approach for classifying natural flow regimes at a continental scale

USGS Publications Warehouse

Archfield, Stacey A.; Kennen, Jonathan G.; Carlisle, Daren M.; Wolock, David M.

2014-01-01

Hydro-ecological stream classification-the process of grouping streams by similar hydrologic responses and, by extension, similar aquatic habitat-has been widely accepted and is considered by some to be one of the first steps towards developing ecological flow targets. A new classification of 1543 streamgauges in the contiguous USA is presented by use of a novel and parsimonious approach to understand similarity in ecological streamflow response. This novel classification approach uses seven fundamental daily streamflow statistics (FDSS) rather than winnowing down an uncorrelated subset from 200 or more ecologically relevant streamflow statistics (ERSS) commonly used in hydro-ecological classification studies. The results of this investigation demonstrate that the distributions of 33 tested ERSS are consistently different among the classification groups derived from the seven FDSS. It is further shown that classification based solely on the 33 ERSS generally does a poorer job in grouping similar streamgauges than the classification based on the seven FDSS. This new classification approach has the additional advantages of overcoming some of the subjectivity associated with the selection of the classification variables and provides a set of robust continental-scale classes of US streamgauges. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Hydro-economic modeling of integrated solutions for the water-energy-land nexus in Africa

NASA Astrophysics Data System (ADS)

Parkinson, S.; Kahil, M.; Wada, Y.; Krey, V.; Byers, E.; Johnson, N. A.; Burek, P.; Satoh, Y.; Willaarts, B.; Langan, S.; Riahi, K.

2017-12-01

This study focused on the development of the Extended Continental-scale Hydro-economic Optimization model (ECHO) and its application to the analysis of long-term water, energy and land use pathways for Africa. The framework is important because it integrates multi-decadal decisions surrounding investments into new water infrastructure, electric power generation and irrigation technologies. The improved linkages in ECHO reveal synergies between water allocation strategies across sectors and the greenhouse gas emissions resulting from electricity supply. The African case study features a reduced-form transboundary river network and associated environmental flow constraints covering surface and groundwater withdrawals. Interactions between local water constraints and the continental-scale economy are captured in the model through the combination of regional electricity markets. Spatially-explicit analysis of land availability is used to restrict future reservoir expansion. The analysis demonstrates the massive investments required to ensure rapidly expanding water, energy and food demands in Africa aligned with human development objectives are met in a sustainable way. Modeled constraints on environmental flows in line with presumptive ecological guidelines trigger diffusion of energy-intensive water supply technologies in water-stressed regions, with implications for the cost and speed of the electricity sector decarbonization required to achieve climate targets.

Numerical analysis of transient laminar forced convection of nanofluids in circular ducts

NASA Astrophysics Data System (ADS)

Sert, İsmail Ozan; Sezer-Uzol, Nilay; Kakaç, Sadık

2013-10-01

In this study, forced convection heat transfer characteristics of nanofluids are investigated by numerical analysis of incompressible transient laminar flow in a circular duct under step change in wall temperature and wall heat flux. The thermal responses of the system are obtained by solving energy equation under both transient and steady-state conditions for hydro-dynamically fully-developed flow. In the analyses, temperature dependent thermo-physical properties are also considered. In the numerical analysis, Al2O3/water nanofluid is assumed as a homogenous single-phase fluid. For the effective thermal conductivity of nanofluids, Hamilton-Crosser model is used together with a model for Brownian motion in the analysis which takes the effects of temperature and the particle diameter into account. Temperature distributions across the tube for a step jump of wall temperature and also wall heat flux are obtained for various times during the transient calculations at a given location for a constant value of Peclet number and a particle diameter. Variations of thermal conductivity in turn, heat transfer enhancement is obtained at various times as a function of nanoparticle volume fractions, at a given nanoparticle diameter and Peclet number. The results are given under transient and steady-state conditions; steady-state conditions are obtained at larger times and enhancements are found by comparison to the base fluid heat transfer coefficient under the same conditions.

Plans and Recent Developments for Fluid Physics Experiments Aboard the ISS

NASA Technical Reports Server (NTRS)

McQuillen, John B.; Motil, Brian J.

2016-01-01

From the very first days of human spaceflight, NASA has been conducting experiments in space to understand the effect of weightlessness on physical and chemically reacting systems. NASA Glenn Research Center (GRC) in Cleveland, Ohio has been at the forefront of this research looking at both fundamental studies in microgravity as well as experiments targeted at reducing the risks to long duration human missions to the moon, Mars, and beyond. In the current International Space Station (ISS) era, we now have an orbiting laboratory that provides the highly desired condition of long-duration microgravity. This allows continuous and interactive research similar to Earth-based laboratories. Because of these capabilities, the ISS is an indispensable laboratory for low gravity research. NASA GRC has been actively involved in developing and operating facilities and experiments on the ISS since the beginning of a permanent human presence on November 2, 2000. As the lead Center for Fluid Physics, NASA GRC is developing and testing the Pack Bed Reactor Experiment (PBRE), Zero Boil Off (ZBOT) Two Phase Flow Separator Experiment (TPFSE), Multiphase Flow Heat Transfer (MFHT) Experiment and the Electro-HydroDynamic (EHD) experiment. An overview each experiment, including its objectives, concept and status will be presented. In addition, data will be made available after a nominal period to NASAs Physical Science Informatics PSI database to the scientific community to enable additional analyses of results.

Computation of Cavitating Flow in a Francis Hydroturbine

NASA Astrophysics Data System (ADS)

Leonard, Daniel; Lindau, Jay

2013-11-01

In an effort to improve cavitation characteristics at off-design conditions, a steady, periodic, multiphase, RANS CFD study of an actual Francis hydroturbine was conducted and compared to experimental results. It is well-known that operating hydroturbines at off-design conditions usually results in the formation of large-scale vaporous cavities. These cavities, and their subsequent collapse, reduce efficiency and cause damage and wear to surfaces. The conventional hydro community has expressed interest in increasing their turbine's operating ranges, improving their efficiencies, and reducing damage and wear to critical turbine components. In this work, mixing planes were used to couple rotating and stationary stages of the turbine which have non-multiple periodicity, and provide a coupled solution for the stay vanes, wicket gates, runner blades, and draft tube. The mixture approach is used to simulate the multiphase flow dynamics, and cavitation models were employed to govern the mass transfer between liquid and gas phases. The solution is compared with experimental results across a range of cavitation numbers which display all the major cavitation features in the machine. Unsteady computations are necessary to capture inherently unsteady cavitation phenomena, such as the precessing vortex rope, and the shedding of bubbles from the wicket gates and their subsequent impingement upon the leading edge of the runner blades. To display these features, preliminary unsteady simulations of the full machine are also presented.

Brigham City Hydro Generation Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ammons, Tom B.

Brigham City owns and operates its own municipal power system which currently includes several hydroelectric facilities. This project was to update the efficiency and capacity of current hydro production due to increased water flow demands that could pass through existing generation facilities. During 2006-2012, this project completed efficiency evaluation as it related to its main objective by completing a feasibility study, undergoing necessary City Council approvals and required federal environmental reviews. As a result of Phase 1 of the project, a feasibility study was conducted to determine feasibility of hydro and solar portions of the original proposal. The results indicatedmore » that the existing Hydro plant which was constructed in the 1960’s was running at approximately 77% efficiency or less. Brigham City proposes that the efficiency calculations be refined to determine the economic feasibility of improving or replacing the existing equipment with new high efficiency equipment design specifically for the site. Brigham City completed the Feasibility Assessment of this project, and determined that the Upper Hydro that supplies the main culinary water to the city was feasible to continue with. Brigham City Council provided their approval of feasibility assessment’s results. The Upper Hydro Project include removal of the existing powerhouse equipment and controls and demolition of a section of concrete encased penstock, replacement of penstock just upstream of the turbine inlet, turbine bypass, turbine shut-off and bypass valves, turbine and generator package, control equipment, assembly, start-up, commissioning, Supervisory Control And Data Acquisition (SCADA), and the replacement of a section of conductors to the step-up transformer. Brigham City increased the existing 575 KW turbine and generator with an 825 KW turbine and generator. Following the results of the feasibility assessment Brigham City pursued required environmental reviews with the DOE and the U.S. Fish and Wildlife Services (USFWS) concurring with the National Environmental Policy Act of 1969 (NEPA) It was determined that Brigham City’s Upper Hydroelectric Power Plant upgrade would have no effect to federally listed or candidate species. However Brigham City has contributed a onetime lump sum towards Bonneville cutthroat trout conservation in the Northern Bonneville Geographic Management Unit with the intention to offset any impacts from the Upper Hydro Project needed to move forward with design and construction and is sufficient for NEPA compliance. No work was done in the river or river bank. During construction, the penstock was disconnected and water was diverted through and existing system around the powerhouse and back into the water system. The penstock, which is currently a 30-inch steel pipe, would be removed and replaced with a new section of 30-inch pipe. Brigham City worked with the DOE and was awarded a new modification and the permission to proceed with Phase III of our Hydro Project in Dec. 2013; with the exception to the modification of the award for the construction phase. Brigham City developed and issued a Request for Proposal for Engineer and Design vendor. Sunrise Engineering was selected for the Design and throughout the Construction Phase of the Upper Hydroelectric Power Plant. Brigham City conducted a Kickoff Meeting with Sunrise June 28, 2013 and received a Scope of Work Brigham City along with engineering firm sent out a RFP for Turbine, Generator and Equipment for Upper Hydro. We select Turbine/Generator Equipment from Canyon Industries located in Deming, WA. DOE awarded Brigham City a new modification and the permission to proceed with Phase III Construction of our Hydro Project. Brigham City Crews removed existing turbine/generator and old equipment alone with feeder wires coming into the building basically giving Caribou Construction an empty shell to begin demolition. Brigham City contracted with Caribou Construction from Jerome, Idaho for the Upper Power Plant construction. A kickoff meeting was June 24, 2014 and demolition was immediately started on building. Because of a delivery delay of Turbine, Generator and Equipment from Canyon Brigham City had to request another extension for the final date of completion. DOE awarded modification (.007) to Brigham City with a new completion date of August 1, 2015. The Turbine has had a few adjustments to help with efficiency; but the Generator had a slight vibration when generator got hot so Canyon Industries had U S Motor’s that manufactured the generator come to check out the issue. The other Equipment seems to be running normal. Brigham City, Sunrise Engineering and Canyon Industries met to determine what the vibration in the generator was and how to solve the issue Us Motor’s found some welds that failed: they have been repaired. U S Motor’s delivered the repaired generator Feb. 17, 2015. Canyon Industries arranged for a crane to installed generator in Power Plant. U S Motor’s balanced and wired generator. Plant Operators put the generator back on line. Canyon Industries returned and gave their approval to keep Hydro online. After Hydro was put back into operations it kept going off line because of overheating issues. Canyon Industries returned and replaced sensors and adjusted them to the proper settings for normal operations. Brigham City added additional steel screens to windows to increase air flow in Power Plant Building. After construction phase of the Upper Hydro Plant some landscaping has been restored around the building additional gravel brought in and leveled out and the road that was cut through for conduits to run wires. A retaining wall was installed to protect penstock. The Upper Hydro Plant is complete and in full operations. The final reimbursement was submitted.« less

77 FR 77070 - Black Bear Hydro Partners, LLC;

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-31

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 2727-086] Black Bear Hydro...: October 24, 2012. d. Submitted By: Black Bear Hydro Partners, LLC (Black Bear Hydro). e. Name of Project... designating Black Bear Hydro as the Commission's non-federal representative for carrying out informal...

Dynamics and stability of wind turbine generators

NASA Technical Reports Server (NTRS)

Hinrichsen, E. N.; Nolan, P. J.

1981-01-01

Synchronous and induction generators are considered. A comparison is made between wind turbines, steam, and hydro units. The unusual phenomena associated with wind turbines are emphasized. The general control requirements are discussed, as well as various schemes for torsional damping such as speed sensitive stabilizer and blade pitch control. Integration between adjacent wind turbines in a wind farm is also considered.

Long-term potential and actual evapotranspiration of two different forests on the Atlantic Coastal Plain

Treesearch

Devendra Amatya; S. Tian; Z. Dai; Ge Sun

2016-01-01

A reliable estimate of potential evapotranspiration (PET) for a forest ecosystem is critical in ecohydrologic modeling related with water supply, vegetation dynamics, and climate change and yet is a challenging task due to its complexity. Based on long-term on-site measured hydro-climatic data and predictions from earlier validated hydrologic modeling studies...

Development of a hybrid 3-D hydrological model to simulate hillslopes and the regional unconfined aquifer system in Earth system models

NASA Astrophysics Data System (ADS)

Hazenberg, P.; Broxton, P. D.; Brunke, M.; Gochis, D.; Niu, G. Y.; Pelletier, J. D.; Troch, P. A. A.; Zeng, X.

2015-12-01

The terrestrial hydrological system, including surface and subsurface water, is an essential component of the Earth's climate system. Over the past few decades, land surface modelers have built one-dimensional (1D) models resolving the vertical flow of water through the soil column for use in Earth system models (ESMs). These models generally have a relatively coarse model grid size (~25-100 km) and only account for sub-grid lateral hydrological variations using simple parameterization schemes. At the same time, hydrologists have developed detailed high-resolution (~0.1-10 km grid size) three dimensional (3D) models and showed the importance of accounting for the vertical and lateral redistribution of surface and subsurface water on soil moisture, the surface energy balance and ecosystem dynamics on these smaller scales. However, computational constraints have limited the implementation of the high-resolution models for continental and global scale applications. The current work presents a hybrid-3D hydrological approach is presented, where the 1D vertical soil column model (available in many ESMs) is coupled with a high-resolution lateral flow model (h2D) to simulate subsurface flow and overland flow. H2D accounts for both local-scale hillslope and regional-scale unconfined aquifer responses (i.e. riparian zone and wetlands). This approach was shown to give comparable results as those obtained by an explicit 3D Richards model for the subsurface, but improves runtime efficiency considerably. The h3D approach is implemented for the Delaware river basin, where Noah-MP land surface model (LSM) is used to calculated vertical energy and water exchanges with the atmosphere using a 10km grid resolution. Noah-MP was coupled within the WRF-Hydro infrastructure with the lateral 1km grid resolution h2D model, for which the average depth-to-bedrock, hillslope width function and soil parameters were estimated from digital datasets. The ability of this h3D approach to simulate the hydrological dynamics of the Delaware River basin will be assessed by comparing the model results (both hydrological performance and numerical efficiency) with the standard setup of the NOAH-MP model and a high-resolution (1km) version of NOAH-MP, which also explicitly accounts for lateral subsurface and overland flow.

New insights into hydrologic sources and sinks in the Nile Basin: A multi-source satellite data analysis

NASA Astrophysics Data System (ADS)

Senay, G. B.; Velpuri, N. M.; Bohms, S.; Demissie, Y.; Gebremichael, M.

2014-12-01

The Nile River is the longest in the world with a length of 6,800 km. However, the contrast between the length of the river or the size of the basin and the comparatively small volume of basin runoff generated is a unique feature of the Nile Basin. Due to non-availability of in-situ hydrologic data, we do not clearly understand the spatial distribution of hydrologic sources and sinks and how much they control input-output dynamics? In this study, we integrated satellite-derived precipitation, and modeled evapotranspiration data (2000-2012) to describe spatial variability of hydrologic sources and sinks in the Nile Basin. We also used long-term gridded runoff and river discharge data (1869-1984) to understand the discrepancy in the observed and expected flow along the Nile River. Results indicate that over 2000-2012 period, 4 out of 11 countries (Ethiopia, Tanzania, Kenya, and Uganda) in the Nile basin showed a positive water balance while three downstream countries (South Sudan, Sudan, and Egypt) showed a negative balance. The top three countries that contribute most to the flow are Ethiopia, Tanzania and Kenya. The study revealed that ~85% of the runoff generated in the Equatorial region is lost in an inter-station basin that includes the Sudd wetlands in South Sudan; this proportion is higher than the reported loss of 50% at the Sudd wetlands alone. The loss in runoff and flow volume at different sections of the river tend to be more than what can be explained by evaporation losses, suggesting a potential recharge to deeper aquifers that are not connected to the Nile channel systems. On the other hand, we also found that the expected average annual Nile flow at Aswan is larger (97 km3) than the reported amount (84 km3). Gravity Recovery and Climate Experiment (GRACE) mass deviation in storage data analysis showed that at annual time-scales, the Nile Basin shows storage change is substantial while over longer-time periods, it is minimal (<1% of basin precipitation). Due to the large variations of the reported Nile flow at different locations and time periods, the study recommends increased hydro-meteorological instrumentation of the basin. This study improves our understanding of the spatial dynamics of water sources and sinks in the Nile basin and identified emerging hydrologic questions that require further attention.

Quantification of downscaled precipitation uncertainties via Bayesian inference

NASA Astrophysics Data System (ADS)

Nury, A. H.; Sharma, A.; Marshall, L. A.

2017-12-01

Prediction of precipitation from global climate model (GCM) outputs remains critical to decision-making in water-stressed regions. In this regard, downscaling of GCM output has been a useful tool for analysing future hydro-climatological states. Several downscaling approaches have been developed for precipitation downscaling, including those using dynamical or statistical downscaling methods. Frequently, outputs from dynamical downscaling are not readily transferable across regions for significant methodical and computational difficulties. Statistical downscaling approaches provide a flexible and efficient alternative, providing hydro-climatological outputs across multiple temporal and spatial scales in many locations. However these approaches are subject to significant uncertainty, arising due to uncertainty in the downscaled model parameters and in the use of different reanalysis products for inferring appropriate model parameters. Consequently, these will affect the performance of simulation in catchment scale. This study develops a Bayesian framework for modelling downscaled daily precipitation from GCM outputs. This study aims to introduce uncertainties in downscaling evaluating reanalysis datasets against observational rainfall data over Australia. In this research a consistent technique for quantifying downscaling uncertainties by means of Bayesian downscaling frame work has been proposed. The results suggest that there are differences in downscaled precipitation occurrences and extremes.

Verification of the New FAST v8 Capabilities for the Modeling of Fixed-Bottom Offshore Wind Turbines: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barahona, B.; Jonkman, J.; Damiani, R.

2014-12-01

Coupled dynamic analysis has an important role in the design of offshore wind turbines because the systems are subject to complex operating conditions from the combined action of waves and wind. The aero-hydro-servo-elastic tool FAST v8 is framed in a novel modularization scheme that facilitates such analysis. Here, we present the verification of new capabilities of FAST v8 to model fixed-bottom offshore wind turbines. We analyze a series of load cases with both wind and wave loads and compare the results against those from the previous international code comparison projects-the International Energy Agency (IEA) Wind Task 23 Subtask 2 Offshoremore » Code Comparison Collaboration (OC3) and the IEA Wind Task 30 OC3 Continued (OC4) projects. The verification is performed using the NREL 5-MW reference turbine supported by monopile, tripod, and jacket substructures. The substructure structural-dynamics models are built within the new SubDyn module of FAST v8, which uses a linear finite-element beam model with Craig-Bampton dynamic system reduction. This allows the modal properties of the substructure to be synthesized and coupled to hydrodynamic loads and tower dynamics. The hydrodynamic loads are calculated using a new strip theory approach for multimember substructures in the updated HydroDyn module of FAST v8. These modules are linked to the rest of FAST through the new coupling scheme involving mapping between module-independent spatial discretizations and a numerically rigorous implicit solver. The results show that the new structural dynamics, hydrodynamics, and coupled solutions compare well to the results from the previous code comparison projects.« less

78 FR 2985 - Moretown Hydro Energy Company; Ampersand Moretown Hydro, LLC; Notice of Application for Transfer...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-15

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 5944-021] Moretown Hydro Energy Company; Ampersand Moretown Hydro, LLC; Notice of Application for Transfer of License, and Soliciting Comments and Motions To Intervene On September 25, 2012, Moretown Hydro Energy Company (transferor...

77 FR 26796 - HydroGenetics, Inc.; Order of Suspension of Trading

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-07

... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] HydroGenetics, Inc.; Order of Suspension of... and accurate information concerning the securities of HydroGenetics, Inc. (``HydroGenetics'') because... require a suspension of trading in the securities of HydroGenetics. Therefore, it is ordered, pursuant to...

Development and validation of a turbulent-mix model for variable-density and compressible flows.

PubMed

Banerjee, Arindam; Gore, Robert A; Andrews, Malcolm J

2010-10-01

The modeling of buoyancy driven turbulent flows is considered in conjunction with an advanced statistical turbulence model referred to as the BHR (Besnard-Harlow-Rauenzahn) k-S-a model. The BHR k-S-a model is focused on variable-density and compressible flows such as Rayleigh-Taylor (RT), Richtmyer-Meshkov (RM), and Kelvin-Helmholtz (KH) driven mixing. The BHR k-S-a turbulence mix model has been implemented in the RAGE hydro-code, and model constants are evaluated based on analytical self-similar solutions of the model equations. The results are then compared with a large test database available from experiments and direct numerical simulations (DNS) of RT, RM, and KH driven mixing. Furthermore, we describe research to understand how the BHR k-S-a turbulence model operates over a range of moderate to high Reynolds number buoyancy driven flows, with a goal of placing the modeling of buoyancy driven turbulent flows at the same level of development as that of single phase shear flows.

78 FR 56224 - Hydro Nelson, Ltd.; Hydro-WM, LLC; Notice of Transfer of Exemption

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2013-09-12

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 3401-049] Hydro Nelson, Ltd.; Hydro-WM, LLC; Notice of Transfer of Exemption 1. By documentation filed July 8, 2013 and supplemented on September 4, 2013, Hydro-WM, LLC informed the Commission that the exemption from licensing for the...

77 FR 9916 - Riverbank Hydro No. 2, LLC; Lock+ Hydro Friends Fund XXXVI; Notice Announcing Preliminary Permit...

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2012-02-21

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14130-000; 14137-000] Riverbank Hydro No. 2, LLC; Lock+ Hydro Friends Fund XXXVI; Notice Announcing Preliminary Permit Drawing The...+ Hydro Friends Fund XXXVI for Project No. 14137-000. \\1\\ Under the Commission's Rules of Practice and...

76 FR 65720 - Lock+ Hydro Friends Fund XXXV, Riverbank Hydro No. 4, LLC; Notice Announcing Preliminary Permit...

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2011-10-24

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 14136-000; Project No. 14139-000] Lock+ Hydro Friends Fund XXXV, Riverbank Hydro No. 4, LLC; Notice Announcing Preliminary... County, Wisconsin.\\1\\ The applications were filed by Lock+ Hydro Friends Fund XXXV for Project No. 14136...

75 FR 61463 - Lock+ Hydro Friends Fund XLIX; FFP Missouri 15, LLC; Notice of Competing Preliminary Permit...

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2010-10-05

...+ Hydro Friends Fund XLIX; FFP Missouri 15, LLC; Notice of Competing Preliminary Permit Applications..., 2010. On July 12, 2010, Lock+ Hydro Friends Fund XLVIII (Hydro Friends) and FFP Missouri 15, LLC (FFP... without the owners' express permission. Hydro Friends' proposed Lock and Dam 14 Hydropower Project...

Soil and geologic controls on recharge and groundwater flow response to climate perturbation: A case study of the Yakima River Basin

NASA Astrophysics Data System (ADS)

Nguyen, T. T.; Pham, H. V.; Bachmann, M.; Tague, C.; Adam, J. C.

2017-12-01

The Yakima River Basin (YRB) is one of the most important agricultural basins in Washington State with annual revenues in excess of $3.2 billion. This intensively irrigated basin is, however, one of the state's most climatically sensitive water resources system as it heavily relies on winter snowpack and limited reservoir storage. Water shortages and drought are expected to be more frequent with climate change, population growth and increasing agricultural demand. This could result in significant impacts on the groundwater system and subsequently the Yakima River. The goal of this study is to assess how soil and geologic characteristics affect catchment recharge and groundwater flow across three catchments within the YRB using a coupled framework including a physically based hydro-ecological model, the Regional Hydro-Ecologic Simulation System (RHESSys) and a groundwater model, MODFLOW. Soil and geologic-related parameters were randomly sampled to use within the Distributed Evaluation of Local Sensitivity Analysis (DELSA) framework to explore their roles in governing catchment recharge and groundwater flow to climate perturbation. Preliminarily results show that catchment recharge is most sensitive to variation in soil transmissivity in two catchments. However, in the other catchment, recharge is more influenced by soil field capacity and bypass recharge. Recharge is also more sensitive to geologic related parameters in catchments where a portion of its flow comes from deep groundwater. When including the effect of climate perturbations, the sensitivity of recharge responses to soil and geologic characteristics varies with temperature and precipitation change. On the other hand, horizontal hydraulic conductivity is the dominant factor that controls groundwater flow responses in catchments with low permeability soil; alternatively, specific storage (and, to some extent, vertical anisotropy) are important in catchments with more conductive soil. The modeling framework developed in this study will be used to investigate the impacts of both climate and drought-relief supplemental pumping on potential recharge, groundwater and streamflow changes in the YRB.

A two-model hydrologic ensemble prediction of hydrograph: case study from the upper Nysa Klodzka river basin (SW Poland)

NASA Astrophysics Data System (ADS)

Niedzielski, Tomasz; Mizinski, Bartlomiej

2016-04-01

The HydroProg system has been elaborated in frame of the research project no. 2011/01/D/ST10/04171 of the National Science Centre of Poland and is steadily producing multimodel ensemble predictions of hydrograph in real time. Although there are six ensemble members available at present, the longest record of predictions and their statistics is available for two data-based models (uni- and multivariate autoregressive models). Thus, we consider 3-hour predictions of water levels, with lead times ranging from 15 to 180 minutes, computed every 15 minutes since August 2013 for the Nysa Klodzka basin (SW Poland) using the two approaches and their two-model ensemble. Since the launch of the HydroProg system there have been 12 high flow episodes, and the objective of this work is to present the performance of the two-model ensemble in the process of forecasting these events. For a sake of brevity, we limit our investigation to a single gauge located at the Nysa Klodzka river in the town of Klodzko, which is centrally located in the studied basin. We identified certain regular scenarios of how the models perform in predicting the high flows in Klodzko. At the initial phase of the high flow, well before the rising limb of hydrograph, the two-model ensemble is found to provide the most skilful prognoses of water levels. However, while forecasting the rising limb of hydrograph, either the two-model solution or the vector autoregressive model offers the best predictive performance. In addition, it is hypothesized that along with the development of the rising limb phase, the vector autoregression becomes the most skilful approach amongst the scrutinized ones. Our simple two-model exercise confirms that multimodel hydrologic ensemble predictions cannot be treated as universal solutions suitable for forecasting the entire high flow event, but their superior performance may hold only for certain phases of a high flow.

Restoring Natural Streamflow Variability by Modifying Multi-purpose Reservoir Operation

NASA Astrophysics Data System (ADS)

Shiau, J.

2010-12-01

Multi-purpose reservoirs typically provide benefits of water supply, hydroelectric power, and flood mitigation. Hydroelectric power generations generally do not consume water. However, temporal distribution of downstream flows is highly changed due to hydro-peaking effects. Associated with offstream diversion of water supplies for municipal, industrial, and agricultural requirements, natural streamflow characteristics of magnitude, duration, frequency, timing, and rate of change is significantly altered by multi-purpose reservoir operation. Natural flow regime has long been recognized a master factor for ecosystem health and biodiversity. Restoration of altered flow regime caused by multi-purpose reservoir operation is the main objective of this study. This study presents an optimization framework that modifying reservoir operation to seeking balance between human and environmental needs. The methodology presented in this study is applied to the Feitsui Reservoir, located in northern Taiwan, with main purpose of providing stable water-supply and auxiliary purpose of electricity generation and flood-peak attenuation. Reservoir releases are dominated by two decision variables, i.e., duration of water releases for each day and percentage of daily required releases within the duration. The current releasing policy of the Feitsui Reservoir releases water for water-supply and hydropower purposes during 8:00 am to 16:00 pm each day and no environmental flows releases. Although greater power generation is obtained by 100% releases distributed within 8-hour period, severe temporal alteration of streamflow is observed downstream of the reservoir. Modifying reservoir operation by relaxing these two variables and reserve certain ratio of streamflow as environmental flow to maintain downstream natural variability. The optimal reservoir releasing policy is searched by the multi-criterion decision making technique for considering reservoir performance in terms of shortage ratio and power generation and downstream hydrologic alterations in terms of ecological relevant indicators. The results show that the proposed methodology can mitigate hydro-peaking effects on natural variability, while maintains efficient reservoir operation.

Fuzzy and process modelling of contour ridge water dynamics

NASA Astrophysics Data System (ADS)

Mhizha, Alexander; Ndiritu, John

2018-05-01

Contour ridges are an in-situ rainwater harvesting technology developed initially for soil erosion control but are currently also widely promoted for rainwater harvesting. The effectiveness of contour ridges depends on geophysical, hydro-climatic and socio economic factors that are highly varied in time and space. Furthermore, field-scale data on these factors are often unavailable. This together with the complexity of hydrological processes at field scale limits the application of classical distributed process modelling to highly-instrumented experimental fields. This paper presents a framework that combines fuzzy logic and process-based approach for modelling contour ridges for rainwater harvesting where detailed field data are not available. Water balance for a representative contour-ridged field incorporating the water flow processes across the boundaries is integrated with fuzzy logic to incorporate the uncertainties in estimating runoff. The model is tested using data collected during the 2009/2010 and 2010/2011 rainfall seasons from two contour-ridged fields in Zhulube located in the semi-arid parts of Zimbabwe. The model is found to replicate soil moisture in the root zone reasonably well (NSE = 0.55 to 0.66 and PBIAS = -1.3 to 6.1 %). The results show that combining fuzzy logic and process based approaches can adequately model soil moisture in a contour ridged-field and could help to assess the water dynamics in contour ridged fields.

Value versus Accuracy: application of seasonal forecasts to a hydro-economic optimization model for the Sudanese Blue Nile

NASA Astrophysics Data System (ADS)

Satti, S.; Zaitchik, B. F.; Siddiqui, S.; Badr, H. S.; Shukla, S.; Peters-Lidard, C. D.

2015-12-01

The unpredictable nature of precipitation within the East African (EA) region makes it one of the most vulnerable, food insecure regions in the world. There is a vital need for forecasts to inform decision makers, both local and regional, and to help formulate the region's climate change adaptation strategies. Here, we present a suite of different seasonal forecast models, both statistical and dynamical, for the EA region. Objective regionalization is performed for EA on the basis of interannual variability in precipitation in both observations and models. This regionalization is applied as the basis for calculating a number of standard skill scores to evaluate each model's forecast accuracy. A dynamically linked Land Surface Model (LSM) is then applied to determine forecasted flows, which drive the Sudanese Hydroeconomic Optimization Model (SHOM). SHOM combines hydrologic, agronomic and economic inputs to determine the optimal decisions that maximize economic benefits along the Sudanese Blue Nile. This modeling sequence is designed to derive the potential added value of information of each forecasting model to agriculture and hydropower management. A rank of each model's forecasting skill score along with its added value of information is analyzed in order compare the performance of each forecast. This research aims to improve understanding of how characteristics of accuracy, lead time, and uncertainty of seasonal forecasts influence their utility to water resources decision makers who utilize them.

Mid- to late-Holocene environmental evolution of the Loire estuary as observed from sedimentary characteristics and benthic foraminiferal assemblages

NASA Astrophysics Data System (ADS)

Durand, M.; Mojtahid, M.; Maillet, G. M.; Proust, J.-N.; Lehay, D.; Ehrhold, A.; Barré, A.; Howa, H.

2016-12-01

We used sedimentological and foraminiferal characteristics of four sedimentary cores, supported by paleogeographical and historical data, to reconstruct the depositional history of the inner Loire estuary (Near Saint-Nazaire, France) and the response of benthic foraminifera to the mid- to late-Holocene marine flooding of the incised valley. These were further used to evaluate the consequent changes in estuarine morphological and hydro-sedimentary patterns during this time period. Our results described significant changes in hydro-sedimentary dynamics over the past 6 kyrs BP. At our location, these changes expressed the combined influence of marine (e.g., tide, storm waves) and fluvial dynamics (e.g., floods), which are linked, on a broader scale, to sea-level variations and the regional climate regime. Three main periods stand out: (1) from 6.0 to 2.5 kyrs BP, when the sea-level rise slowed down, a large brackish bay extended over and around the study area. The fine-grained tidal rythmites recorded north of the Bilho bank (the main tidal bar located in our study area) indicated a calm depositional environment, protected from the main riverine influence. The presence of thick flood deposits from 5.4 to 4.0 kyrs BP near the Bilho bank indicates further the dominance of humid conditions. (2) From 2.5 kyrs BP to 1850 CE (pre-industrial state), sea-level stabilized at its present value, and the pre-existing bay was progressively infilled. North of the Bilho bank, near a major mudflat (Méan), the generally homogenous sedimentation composed of silty muds rich in organic matter indicated a sheltered environment; the main water flow channel being located south of the Bilho bank. Within this overall homogenous sedimentation, foraminiferal assemblages described rather accurately the progressive infilling of the valley (indicated by a decrease in the proportions of outer estuarine species), accompanied with the channelization of the main entering marine currents (tide, storm waves) (indicated by an increase in the proportions of transported species from the adjacent upper continental shelf), and finally the buildup of the Méan mudflat and the stabilization of the environment to its present day configuration (indicated by the dominance of autochthonous inner estuarine species). (3) Since 1850 CE, the human impact progressively modified the general landscape of our study area with the construction of the Saint-Nazaire shipyard, the digging of the northern navigation channel and the polderization of the northern Bay. The southern channel was progressively abandoned by the main water flow in favor of the newly dug northern channel, causing the southern migration of the Bilho sandbank and the progressive filling of the southern channel.

Self-organization, preferential flow and rainfall runoff behavior - is there a connection?

NASA Astrophysics Data System (ADS)

Zehe, Erwin; Blume, Theresa; Kleidon, Axel; Ehret, Uwe; Scherer, Ulrike; Westhoff, Martijn

2013-04-01

In line with the studies of Kleidon et al. (2012) and Zehe et al. (2010) the proposed study analyzes mass flow related flows of free energy in open hydrological systems - hillslopes and small catchments - using thermodynamics methods. Why a thermodynamic treatment? A small part of the kinetic energy input from incoming rainfall is dissipated into heat and to break up soil aggregates. Depending on the partitioning of the incoming rainfall into overland flow and soil water, the remaining part of the incoming kinetic energy is partly transformed into potential energy of surface water and subsequently partly exported as kinetic energy of overland flow from the system; the rest is dissipated by frictional losses. The other part of rainfall infiltrates thereby increasing potential energy of soil water but depleting at the same time (gradients in) capillary binding energy of soil water, which again comprises energy dissipation into heat of immersion. Although, these mass fluxes are not associated with large heat fluxes, they reflect the overall conservation of energy as well as the second law of thermodynamics. They require thus a thermodynamic treatment, because tiny amounts of kinetic energy, surface energy and potential energy are dissipated into heat: this implies irreversibility and explains why water does not flow uphill. Soil hydraulic equilibrium (HE), arising from a balance in potential and capillary binding energy in soil, can be interpreted as a state of maximum entropy in soil. Soil water potential, defined as sum of matric potential and gravity potential, is in HE equal to zero along the soil profile. This corresponds to a state of maximum entropy due to a zero potential gradient, which implies due to Zehe et al. (2010) a state of minimum (Helmholtz) free energy. Our first main objective is to quantify to which extent connected preferential flow path, in our case vertical macropores and the river network enhance flow velocities at a given driving gradient and thus power in the associated mass fluxes. This implies either an enhanced export of free energy in form of kinetic energy in case of the river net, or an accelerated reduction of potential energy of infiltrating surface water which implies a reduction free energy in form of capillary binding energy of soil water. We hypothesize (H1) that network like structures act as dissipative structures "serving the purpose" of reducing the relaxation time to a state of lower "free" energy in the entire system. This is because they minimize dissipative losses of kinetic energy along their extent. This faster relaxation towards a state of smaller free energy is deemed to be favorable for mechanic stability of the entire hydrological system because a) mass flows perform due to the enhanced export of kinetic energy less work on the system itself and b) mechanical stress from ponded surface water is quickly reduced by fast infiltration and preferential flow. Our second main objective is, in line with the study of Zehe et al. (2010), the search for thermodynamic optimal hillslope architectures both with respect to the surface density of vertical macropores in soil and with respect to the spatial arrangement of soil types and macropores at the hillslope scale. In line with H1 we suggest (H2) that a hydro-geo-ecosystem is closer to a functional optimum than other possible configurations if it dissipates and exports more of the kinetic energy input from incoming rainfall by redistributing water against internal gradients and exporting water against macroscale geo-potential gradients. Note that H2 does not postulate that functionally optimal hillslope architectures necessarily exist, if they exist H2 implies however that they maximize entropy production and thus reduction of total free energy of the system at a "wisely" selected time scale. The surface density of apparent macropores does for instance control the tradeoff between Hortonian overland flow formation and infiltration, which implies a tradeoff between the amount of kinetic energy input from rainfall that is converted in to power associated with overland flow and power associated with soil water flows depleting gradients in soil water potential. Does this tradeoff imply an optimum surface density of macropores at the hillslope scale in the sense that power in soil water flow is maximized or reduction of free energy is maximized? In case such an optimum hillslope architecture existed, and in case that the evolution of the hydrological systems of interested was indeed in accordance with hypothesis H2, this optimal architecture should allow an acceptable uncalibrated simulation of the systems rainfall -runoff behavior (if the selected model structure can properly represent this architecture). We will address these questions and test the main implications of our hypotheses by means of numerical experiments with the physically based hydrological model CATFLOW. We use behavioral model structures as basic model setup, which have been shown to closely portray system behavior and its architecture in a sense that they reproduce distributed observations of soil moisture and catchment scale discharge and represent the observed structural and textural signatures of soils, flow networks and vegetation. Our test areas are the Weiherbach (Germany) and the Malalcahuello research headwaters (Chile), which are located in distinctly different hydro-climatic and hydro-pedological settings. Within the numerical experiments we will simulate the full concert of hydrological processes at the hillslope and headwater scales for meaningful perturbations of the behavioral model structure and compare them with respect to dynamics of free energy and production of power. These perturbations affect a) the river network and the geomorphology of the Weiherbach catchment, b) surface density of macropores in both catchments c) the spatial arrangement of soils and preferential pathways at the hillslope scale in the Weiherbach catchment. References: Kleidon, A., Zehe, E., Ehret, U., and Scherer, U.: Thermodynamics, maximum power, and the dynamics of preferential river flow structures on continents, Hydrol. Earth Syst. Sci. Discuss., 9, 7317-7378, 10.5194/hessd-9-7317-2012, 2012. Zehe, E., Blume, T., and Blöschl, G.: The principle of 'maximum energy dissipation': a novel thermodynamic perspective on rapid water flow in connected soil structures, Phil. Trans. R. Soc. B, 1-10, doi:10.1098/rstb.2009.0308, 2010.

77 FR 13317 - Lock+ Hydro Friends Fund XVIII, Upper Hydroelectric, LLC, FFP Project 95, LLC, Riverbank Hydro No...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-06

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14261-000, 14268-000, 14277-000, 14281-000] Lock+ Hydro Friends Fund XVIII, Upper Hydroelectric, LLC, FFP Project 95, LLC.... Lock+ Hydro Friends Fund XVIII: Project No. 14261-000. 2. Riverbank Hydro No. 25, LLC: Project No...

75 FR 49925 - Lock+ Hydro Friends Fund XLIX; FFP Missouri 14, LLC; Notice of Competing Preliminary Permit...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-16

.... 13813-000] Lock+ Hydro Friends Fund XLIX; FFP Missouri 14, LLC; Notice of Competing Preliminary Permit... August 9, 2010. Lock+ Hydro Friends Fund XLIX (Hydro Friends) and FFP Missouri 14, LLC (FFP) filed...-station located south-west of the dam. Hydro Friends is also exploring alternatives that would locate the...

77 FR 10740 - Lock+ Hydro Friends Fund VIII, FFP Project 92, LLC, Riverbank Hydro No. 24, LLC; Notice...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-23

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14262-000, 14276-000, 14280-000] Lock+ Hydro Friends Fund VIII, FFP Project 92, LLC, Riverbank Hydro No. 24, LLC; Notice... Counties, Kentucky. The applications were filed by Lock+ Hydro Friends Fund VIII for Project No. 14262-000...

Hot Moments in Cold Spots - Investigating Reactive Transport Patterns at Aquifer-River Interfaces by Heat Tracers and Distributed Sensor Networks

NASA Astrophysics Data System (ADS)

Krause, Stefan; Angermann, Lisa; Naden, Emma; Cassidy, Nigel; Blume, Theresa

2010-05-01

The mixing of groundwater and surface water in hyporheic zones often coincides with high redox reactivity and chemical transformation potential. Depending on redox conditions and reaction types, hyporheic mixing of groundwater and surface water can lead to either attenuation or enrichment of pollutants or nutrients with diametrical implications for stream and aquifer hydro-ecological conditions. This study investigates the reactive transport of nitrate and a chlorinated solvent (Trichloroethylene - TCE) at the aquifer-river interface of a UK lowland river. In this study, distributed temperature sensor networks and hydro-geophysical methods, which have been applied for identifying structural streambed heterogeneity and tracing aquifer river exchange, were combined with hydro-chemical analyses of hyporheic multi-component reactive transport. In stream Electric Resistivity Tomography has been applied to map the complex spatial distribution of highly conductive sandy and gravely sediments in contrast to semi-confining, low conductivity peat lenses. Reach scale (1km) spatial patterns and temporal dynamics of aquifer-river exchange have been identified by heat tracer experiments based on fibre-optic Distributed Temperature Sensing in combination with 2D thermocouple-arrays and small scale heat pulse injection methods for tracing shallow (25 cm) hyporheic flow paths. Spatial patterns of hyporheic redox conditions, dissolved oxygen and organic carbon (DOC) content as well as concentrations of major anions, TCE and its decay products have been observed in 48 nested multi-level piezometers and passive DET (Diffusive Equilibrium in Thin film) gel probes. Our results indicate that patterns of cold spots in streambed sediments can be attributed to fast groundwater up-welling in sandy and gravely sediments resulting in low hyporheic residence times. Contrasting conditions were found at warmer areas at the streambed surface where groundwater - surface water exchange was inhibited by the existence of peat or clay lenses within the streambed. These flow-inhibiting structures have been shown to cause semi-confined conditions in the up-welling groundwater, resulting in long residence times and increased redox-reactivity. Anoxic conditions and high DOC contents combined with long residence times underneath peat layers cause highly efficient denitrification rates, reducing nitrate concentrations from > 50mg/l to below the level of detection. In contrast, sandy and gravely areas of fast groundwater up-welling where characterized by only marginal changes in nitrate concentrations. Observation of the reactive transport of the chlorinated solvent groundwater plume into the river suggest that natural attenuation of TCE, which competes with nitrate for DOC as reductive agent, is limited to the semi-confined, anoxic, low nitrate - high DOC groundwater pockets underneath streambed peat lenses. The investigations supported the development of a conceptual model of aquifer - river exchange and hyporheic reactivity in lowland rivers including temperature traceable "hyporheic super-reactors" of great importance for river restoration, water quality and ecology status.

Hot Moments in Cold Spots - Using Heat Tracers and Distributed Sensor Networks to Investigate Reactive Transport Patterns at Aquifer-River Interfaces

NASA Astrophysics Data System (ADS)

Krause, S.; Angermann, L.; Naden, E.; Cassidy, N. J.

2009-12-01

The mixing of groundwater and surface water in hyporheic zones often coincides high redox reactivity and chemical transformation potential. Depending on redox conditions and reaction types, hyporheic mixing of groundwater and surface water can lead to either attenuation or enrichment of pollutants or nutrients with diametrical implications for stream and aquifer hydro-ecology. This study investigates the reactive transport of nitrate and the chlorinated solvent Trichloroethylene (TCE) at the aquifer-river interface of a UK lowland river. The investigations are based on novel distributed sensor networks and hydro-geophysical methods for the identification of structural streambed heterogeneity and the tracing of aquifer river exchange combined with hydro-chemical analyses of hyporheic multi-component reactive transport. In stream Electric Resistivity Tomography and Ground Penetrating Radar have been applied to map the complex spatial distribution of highly conductive sandy and gravely sediments in contrast to semi-confining, low conductivity peat lenses. Reach scale (1km) spatial patterns and temporal dynamics of aquifer-river exchange have been identified by heat tracer experiments based on fibre-optic Distributed Temperature Sensing in combination with 2D thermocouple-arrays and small scale heat pulse injection methods for tracing shallow (25 cm) hyporheic flow paths. Spatial patterns of hyporheic redox conditions, dissolved oxygen and organic carbon (DOC) content as well as concentrations of major anions, TCE and its decay products have been observed in 48 nested multi-level piezometers and passive DET (Diffusive Equilibrium in Thin film) gel probes. Our results indicate that patterns of cold spots in streambed sediments can be attributed to fast groundwater up-welling in sandy and gravely sediments resulting in low hyporheic residence times. Contrasting conditions were found at warmer areas at the streambed surface where groundwater - surface water exchange was inhibited by the existence of peat or clay lenses within the streambed. These flow-inhibiting structures have been shown to cause semi-confined conditions in the up-welling groundwater, resulting in long residence times and increased redox-reactivity. Anoxic conditions and high DOC contents combined with long residence times underneath peat layers cause highly efficient denitrification rates, reducing nitrate concentrations from > 50mg/l to below the level of detection. In contrast, sandy and gravely areas of fast groundwater up-welling where characterized by only marginal changes in nitrate concentrations. Observation of the reactive transport of the chlorinated solvent groundwater plume into the river suggest that natural attenuation of TCE, which competes with nitrate for DOC as reductive agent, is limited to the semi-confined, anoxic, low nitrate - high DOC groundwater pockets underneath streambed peat lenses. The investigations supported the development of a conceptual model of aquifer - river exchange and hyporheic reactivity in lowland rivers including temperature traceable “hyporheic super-reactors” of great importance for river restoration, water quality and ecology status.

Satellite Based Probabilistic Snow Cover Extent Mapping (SCE) at Hydro-Québec

NASA Astrophysics Data System (ADS)

Teasdale, Mylène; De Sève, Danielle; Angers, Jean-François; Perreault, Luc

2016-04-01

Over 40% of Canada's water resources are in Quebec and Hydro-Quebec has developed potential to become one of the largest producers of hydroelectricity in the world, with a total installed capacity of 36,643 MW. The Hydro-Québec fleet park includes 27 large reservoirs with a combined storage capacity of 176 TWh, and 668 dams and 98 controls. Thus, over 98% of all electricity used to supply the domestic market comes from water resources and the excess output is sold on the wholesale markets. In this perspective the efficient management of water resources is needed and it is based primarily on a good river flow estimation including appropriate hydrological data. Snow on ground is one of the significant variables representing 30% to 40% of its annual energy reserve. More specifically, information on snow cover extent (SCE) and snow water equivalent (SWE) is crucial for hydrological forecasting, particularly in northern regions since the snowmelt provides the water that fills the reservoirs and is subsequently used for hydropower generation. For several years Hydro Quebec's research institute ( IREQ) developed several algorithms to map SCE and SWE. So far all the methods were deterministic. However, given the need to maximize the efficient use of all resources while ensuring reliability, the electrical systems must now be managed taking into account all risks. Since snow cover estimation is based on limited spatial information, it is important to quantify and handle its uncertainty in the hydrological forecasting system. This paper presents the first results of a probabilistic algorithm for mapping SCE by combining Bayesian mixture of probability distributions and multiple logistic regression models applied to passive microwave data. This approach allows assigning for each grid point, probabilities to the set of the mutually exclusive discrete outcomes: "snow" and "no snow". Its performance was evaluated using the Brier score since it is particularly appropriate to measure the accuracy of probabilistic discrete predictions. The scores were measured by comparing the snow probabilities produced by our models with the Hydro-Québec's snow ground data.

Brownian dynamics simulation of rigid particles of arbitrary shape in external fields.

PubMed

Fernandes, Miguel X; de la Torre, José García

2002-12-01

We have developed a Brownian dynamics simulation algorithm to generate Brownian trajectories of an isolated, rigid particle of arbitrary shape in the presence of electric fields or any other external agents. Starting from the generalized diffusion tensor, which can be calculated with the existing HYDRO software, the new program BROWNRIG (including a case-specific subprogram for the external agent) carries out a simulation that is analyzed later to extract the observable dynamic properties. We provide a variety of examples of utilization of this method, which serve as tests of its performance, and also illustrate its applicability. Examples include free diffusion, transport in an electric field, and diffusion in a restricting environment.

Three-dimensional modelling of slope stability using the Local Factor of Safety concept

NASA Astrophysics Data System (ADS)

Moradi, Shirin; Huisman, Sander; Beck, Martin; Vereecken, Harry; Class, Holger

2017-04-01

Slope stability is governed by coupled hydrological and mechanical processes. The slope stability depends on the effective stress, which in turn depends on the weight of the soil and the matrix potential. Therefore, changes in water content and matrix potential associated with infiltration will affect slope stability. Most available models describing these coupled hydro-mechanical processes either rely on a one- or two-dimensional representation of hydrological and mechanical properties and processes, which obviously is a strong simplification in many applications. Therefore, the aim of this work is to develop a three-dimensional hydro-mechanical model that is able to capture the effect of spatial and temporal variability of both mechanical and hydrological parameters on slope stability. For this, we rely on DuMux, which is a free and open-source simulator for flow and transport processes in porous media that facilitates coupling of different model approaches and offers flexibility for model development. We use the Richards equation to model unsaturated water flow. The simulated water content and matrix potential distribution is used to calculate the effective stress. We only consider linear elasticity and solve for statically admissible fields of stress and displacement without invoking failure or the redistribution of post-failure stress or displacement. The Local Factor of Safety concept is used to evaluate slope stability in order to overcome some of the main limitations of commonly used methods based on limit equilibrium considerations. In a first step, we compared our model implementation with a 2D benchmark model that was implemented in COMSOL Multiphysics. In a second step, we present in-silico experiments with the newly developed 3D model to show the effect of slope morphology, spatial variability in hydraulic and mechanical material properties, and spatially variable soil depth on simulated slope stability. It is expected that this improved physically-based three-dimensional hydro-mechanical model is able to provide more reliable slope instability predictions in more complex situations.

Using Temperature as a Tracer to Study Fluid Flow Patterns On and Offshore Taiwan

NASA Astrophysics Data System (ADS)

Chi, W. C.

2017-12-01

Fluid flows are a dynamic system in the crust that affect crustal deformation and formation of natural resources. It is difficult to study fluid flow velocity instrumentally, but temperature data offers a quantitative tool that can be used as a tracer to study crustal hydrogeology. Here we present numerical techniques we have applied to study the fluid migration velocity along conduits including faults in on and offshore settings. Offshore SW Taiwan, we use a bottom-simulating reflector (BSR) from seismic profiles to study the temperature field at several hundred meters subbottom depth. The BSR is interpreted as the base of a gas hydrate stability zone under the seabed. Gas hydrates are solid-state water with gas molecules enclosed, which can be found where the temperature, pressure, and salinity conditions allow hydrates to be stable. Using phase diagrams and hydro pressure information we can derive the temperature at the BSR. BSRs are widespread in the study area, providing very dense temperature field information which shows upward bending of the BSR near faults. We have quantitatively estimated the 1D and 2D fluid flow patterns required to fit the BSR-based temperature field. This shows that fault zones can act as conduits with high permeability parallel to the fault planes. On the other hand, fault zones can also act as barriers to fluid flow, as demonstrated in our onland temperature data. We have collected temperature profiles at several bore holes onland that are very close together. The preliminary results show that the fault zones separate the ground water systems, causing very different geothermal gradients. Our results show that the physical properties of fault zones can be anisotropic, as demonstrated in previous work. Future work includes estimating the regional water expulsion budget offshore SW Taiwan, in particular for several gas hydrate sites.

Development and modelisation of a hydro-power conversion system based on vortex induced vibration

NASA Astrophysics Data System (ADS)

Lefebure, David; Dellinger, Nicolas; François, Pierre; Mosé, Robert

2016-11-01

The Vortex Induced Vibration (VIV) phenomenon leads to mechanical issues concerning bluff bodies immerged in fluid flows and have therefore been studied by numerous authors. Moreover, an increasing demand for energy implies the development of alternative, complementary and renewable energy solutions. The main idea of EauVIV project consists in the use of VIV rather than its deletion. When rounded objects are immerged in a fluid flow, vortices are formed and shed on their downstream side, creating a pressure imbalance resulting in an oscillatory lift. A convertor modulus consists of an elastically mounted, rigid cylinder on end-springs, undergoing flow- induced motion when exposed to transverse fluid-flow. These vortices induce cyclic lift forces in opposite directions on the circular bar and cause the cylinder to vibrate up and down. An experimental prototype was developed and tested in a free-surface water channel and is already able to recover energy from free-stream velocity between 0.5 and 1 m.s -1. However, the large number of parameters (stiffness, damping coefficient, velocity of fluid flow, etc.) associated with its performances requires optimization and we choose to develop a complete tridimensionnal numerical model solution. A 3D numerical model has been developed in order to represent the real system behavior and improve it through, for example, the addition of parallel cylinders. The numerical model build up was carried out in three phases. The first phase consists in establishing a 2D model to choose the turbulence model and quantify the dependence of the oscillations amplitudes on the mesh size. The second corresponds to a 3D simulation with cylinder at rest in first time and with vertical oscillation in a second time. The third and final phase consists in a comparison between the experimental system dynamic behavior and its numerical model.

Control Strategies for Zebra Mussel Infestations at Public Facilities

DTIC Science & Technology

1992-07-01

detailed examina- tion of hard -to-reach surfaces or specific components (such as fire protection systems or intake pipes for sensor devices) should...trash racks. Trash racks could become partially clogged with zebra mussels, shells , and other debris. Flow through the openings would be reduced, and... shells to the top of the lock wall. These are now used by Ontario Hydro for removing zebra mussels. At most facilities, the culvert is totally dewatered

Hydrogen-fueled scramjets: Potential for detailed combustor analysis

NASA Technical Reports Server (NTRS)

Beach, H. L., Jr.

1976-01-01

Combustion research related to hypersonic scramjet (supersonic combustion ramjet) propulsion is discussed from the analytical point of view. Because the fuel is gaseous hydrogen, mixing is single phase and the chemical kinetics are well known; therefore, the potential for analysis is good relative to hydro-carbon fueled engines. Recent progress in applying two and three dimensional analytical techniques to mixing and reacting flows indicates cause for optimism, and identifies several areas for continuing effort.

Hydro-geomorphologic events in Portugal and its association with Circulation weather types

NASA Astrophysics Data System (ADS)

Pereira, Susana; Ramos, Alexandre M.; Rebelo, Luís; Trigo, Ricardo M.; Zêzere, José L.

2017-04-01

Floods and landslides correspond to the most hazardous weather driven natural disasters in Portugal. A recent improvement on their characterization has been achieved with the gathering of basic information on past floods and landslides that caused social consequences in Portugal for the period 1865-2015 through the DISASTER database (Zêzere et al., 2014). This database was built under the assumption that strong social impacts of floods and landslides are sufficient relevant to be reported consistently by national and regional newspapers. The DISASTER database contains detailed information on the location, date of occurrence and social impacts (fatalities, injuries, missing people, evacuated and homeless people) of each individual hydro-geomorphologic case (1677 flood cases and 292 landslide cases). These hydro-geomorphologic disaster cases are grouped in a restrict number of DISASTER events that were selected according to the following criteria: a set of at least 3 DISASTER cases sharing the same trigger in time (with no more than 3 days without cases), which have a widespread spatial extension related to the triggering mechanism and a certain magnitude. In total, the DISASTER database includes 134 events (3.7 average days of duration) that generated high social impacts in Portugal (962 fatalities and 40878 homeless people). Each DISASTER event was characterized with the following attributes: hydro-geomorphologic event type (e.g landslides, floods, flash floods, urban floods); date of occurrence (year, month and days); duration in days; spatial location in GIS; number of fatalities, injured, evacuated and homeless people; and weather type responsible for triggering the event. The atmospheric forcing at different time scales is the main trigger for the hydro-meteorological DISASTER events occurred in Portugal. In this regard there is an urge for a more systematic assessment of the weather types associated to flood and landslide damaging events to correctly characterize the climatic forcing of hydro-geomorphologic risk in Portugal. The weather type classification used herein is an automated version of the Lamb weather type procedure, initially developed for the United Kingdom and often named circulation weather types (CWT) and latter adapted for Portugal. We computed the daily CWT for the 1865-2015 period by means of the daily SLP retrieved from the 20 Century Reanalysis dataset. The relationship between the CWTs and the hydro-meteorological events in Portugal shows that the cyclonic, westerly and southwesterly are CWTs frequently associated with major socio-economic impacts of DISASTER events. In addition, CWT basic variables (flow strength, vorticity and direction) were used to better understand the impacts of the meteorological conditions in the hydro-meteorological events in Portugal. Reference: Zêzere, J. L., Pereira, S., Tavares, A. O., Bateira, C., Trigo, R. M., Quaresma, I., Santos, P. P., Santos, M. and Verde, J.: DISASTER: a GIS database on hydro-geomorphologic disasters in Portugal, Nat. Hazards, 72(2), 503-532, doi:10.1007/s11069-013-1018-y, 2014. This work was supported by the project FORLAND - Hydrogeomorphologic risk in Portugal: driving forces and application for land use planning [grant number PTDC/ATPGEO/1660/2014] funded by the Portuguese Foundation for Science and Technology (FCT), Portugal. A. M. Ramos was also supported by a FCT postdoctoral grant (FCT/DFRH/ SFRH/BPD/84328/2012).

The distribution of saturated clusters in wetted granular materials

NASA Astrophysics Data System (ADS)

Li, Shuoqi; Hanaor, Dorian; Gan, Yixiang

2017-06-01

The hydro-mechanical behaviour of partially saturated granular materials is greatly influenced by the spatial and temporal distribution of liquid within the media. The aim of this paper is to characterise the distribution of saturated clusters in granular materials using an optical imaging method under different water drainage conditions. A saturated cluster is formed when a liquid phase fully occupies the pore space between solid grains in a localized region. The samples considered here were prepared by vibrating mono-sized glass beads to form closely packed assemblies in a rectangular container. A range of drainage conditions were applied to the specimen by tilting the container and employing different flow rates, and the liquid pressure was recorded at different positions in the experimental cell. The formation of saturated clusters during the liquid withdrawal processes is governed by three competing mechanisms arising from viscous, capillary, and gravitational forces. When the flow rate is sufficiently large and the gravity component is sufficiently small, the viscous force tends to destabilize the liquid front leading to the formation of narrow fingers of saturated material. As the water channels along these liquid fingers break, saturated clusters are formed inside the specimen. Subsequently, a spatial and temporal distribution of saturated clusters can be observed. We investigated the resulting saturated cluster distribution as a function of flow rate and gravity to achieve a fundamental understanding of the formation and evolution of such clusters in partially saturated granular materials. This study serves as a bridge between pore-scale behavior and the overall hydro-mechanical characteristics in partially saturated soils.

75 FR 71104 - Lock Hydro Friends Fund XXXV; FFP Missouri 7, LLC; Dashields Hydro, LLC; Notice of Competing...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-22

.... 13735-000; Project No. 13756-000; Project No. 13779-000] Lock Hydro Friends Fund XXXV; FFP Missouri 7... Soliciting Comments, and Motions To Intervene November 15, 2010. On May 18, 2010, Lock Hydro Friends Fund.... Descriptions of the proposed Dashields Lock and Dam Projects: Lock Hydro Friends Fund XXXV's project (Project...

77 FR 10741 - Lock+ Hydro Friends Fund XII, BOST2, LLC, Riverbank Hydro No. 21, LLC, FFP Project 96, LLC...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-23

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14260-000, 14264-000, 14267-000, 14273-000] Lock+ Hydro Friends Fund XII, BOST2, LLC, Riverbank Hydro No. 21, LLC, FFP Project... Greene and Hale counties, Alabama. The applications were filed by Lock+ Hydro Friends Fund XII for...

76 FR 73614 - Lock Hydro Friends Fund XII; BOST2 LLC; Riverbank Hydro No. 21 LLC; FFP Project 96 LLC; Notice of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-29

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14260-000; 14264-000; 14267-000; 14273-000] Lock Hydro Friends Fund XII; BOST2 LLC; Riverbank Hydro No. 21 LLC; FFP Project 96..., Motions To Intervene, and Competing Applications On September 1, 2011, Lock Hydro Friends Fund XII (Lock...

78 FR 57796 - Safety Zone; Pro Hydro-X Tour, Atlantic Ocean, Islamorada, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-20

... 1625-AA00 Safety Zone; Pro Hydro-X Tour, Atlantic Ocean, Islamorada, FL AGENCY: Coast Guard, DHS... waters of the Atlantic Ocean, Islamorada, Florida during the Pro Hydro- X Tour. The Pro Hydro-X Tour is a... course for each race. The Pro Hydro-X Tour is scheduled to take place on September 20, 21, and 22, 2013...

The Effect of Turbulence on the Flame Velocity in Gas Mixtures

NASA Technical Reports Server (NTRS)

Damkoehler, Gerhard

1947-01-01

The present report deals with the effect of turbulence on the propagation of the flame. Being based upon experiments with laminar as well as turbulent Bunsen flames, both the physico-chemical and the hydro-dynamical aspects of the problem are analyzed. A number of new deductions, interesting from the point of view of engine combustion and other very rapidly changing flame reactions, are made.

Cloud-based NEXRAD Data Processing and Analysis for Hydrologic Applications

NASA Astrophysics Data System (ADS)

Seo, B. C.; Demir, I.; Keem, M.; Goska, R.; Weber, J.; Krajewski, W. F.

2016-12-01

The real-time and full historical archive of NEXRAD Level II data, covering the entire United States from 1991 to present, recently became available on Amazon cloud S3. This provides a new opportunity to rebuild the Hydro-NEXRAD software system that enabled users to access vast amounts of NEXRAD radar data in support of a wide range of research. The system processes basic radar data (Level II) and delivers radar-rainfall products based on the user's custom selection of features such as space and time domain, river basin, rainfall product space and time resolution, and rainfall estimation algorithms. The cloud-based new system can eliminate prior challenges faced by Hydro-NEXRAD data acquisition and processing: (1) temporal and spatial limitation arising from the limited data storage; (2) archive (past) data ingestion and format conversion; and (3) separate data processing flow for the past and real-time Level II data. To enhance massive data processing and computational efficiency, the new system is implemented and tested for the Iowa domain. This pilot study begins by ingesting rainfall metadata and implementing Hydro-NEXRAD capabilities on the cloud using the new polarimetric features, as well as the existing algorithm modules and scripts. The authors address the reliability and feasibility of cloud computation and processing, followed by an assessment of response times from an interactive web-based system.

Integrated Hydrographical Basin Management. Study Case - Crasna River Basin

NASA Astrophysics Data System (ADS)

Visescu, Mircea; Beilicci, Erika; Beilicci, Robert

2017-10-01

Hydrographical basins are important from hydrological, economic and ecological points of view. They receive and channel the runoff from rainfall and snowmelt which, when adequate managed, can provide fresh water necessary for water supply, irrigation, food industry, animal husbandry, hydrotechnical arrangements and recreation. Hydrographical basin planning and management follows the efficient use of available water resources in order to satisfy environmental, economic and social necessities and constraints. This can be facilitated by a decision support system that links hydrological, meteorological, engineering, water quality, agriculture, environmental, and other information in an integrated framework. In the last few decades different modelling tools for resolving problems regarding water quantity and quality were developed, respectively water resources management. Watershed models have been developed to the understanding of water cycle and pollution dynamics, and used to evaluate the impacts of hydrotechnical arrangements and land use management options on water quantity, quality, mitigation measures and possible global changes. Models have been used for planning monitoring network and to develop plans for intervention in case of hydrological disasters: floods, flash floods, drought and pollution. MIKE HYDRO Basin is a multi-purpose, map-centric decision support tool for integrated hydrographical basin analysis, planning and management. MIKE HYDRO Basin is designed for analyzing water sharing issues at international, national and local hydrographical basin level. MIKE HYDRO Basin uses a simplified mathematical representation of the hydrographical basin including the configuration of river and reservoir systems, catchment hydrology and existing and potential water user schemes with their various demands including a rigorous irrigation scheme module. This paper analyzes the importance and principles of integrated hydrographical basin management and develop a case study for Crasna river basin, with the use of MIKE HYDRO Basin advanced hydroinformatic tool for integrated hydrographical basin analysis, planning and management.

Antioxidant activity of Piper nigrum L. essential oil extracted by supercritical CO₂ extraction and hydro-distillation.

PubMed

Bagheri, Hossein; Abdul Manap, Mohd Yazid Bin; Solati, Zeinab

2014-04-01

The aim of this study was to optimize the antioxidant activity of Piper nigrum L. essential oil extracted using the supercritical carbon dioxide (SC-CO₂) technique. Response surface methodology was applied using a three-factor central composite design to evaluate the effects of three independent extraction variables: pressure of 15-30 MPa, temperature of 40-50 °C and dynamic extraction time of 40-80 min. The DPPH radical scavenging method was used to evaluate the antioxidant activity of the extracts. The results showed that the best antioxidant activity was achieved at 30 MPa, 40 °C and 40 min. The extracts were analyzed by GC-FID and GC-MS. The main components extracted using SC-CO₂ extraction in optimum conditions were β-caryophyllene (25.38 ± 0.62%), limonene (15.64 ± 0.15%), sabinene (13.63 ± 0.21%), 3-carene (9.34 ± 0.04%), β-pinene (7.27 ± 0.05%), and α-pinene (4.25 ± 0.06%). The essential oil obtained through this technique was compared with the essential oil obtained using hydro-distillation. For the essential oil obtained by hydro-distillation, the most abundant compounds were β-caryophyllene (18.64 ± 0.84%), limonene (14.95 ± 0.13%), sabinene (13.19 ± 0.17%), 3-carene (8.56 ± 0.11%), β-pinene (9.71 ± 0.12%), and α-pinene (7.96 ± 0.14%). Radical scavenging activity of the extracts obtained by SC-CO₂ and hydro-distillation showed an EC₅₀ of 103.28 and 316.27 µg mL(-1) respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

Experimental and numerical analysis of the dynamic behaviour in tension of an armour steel for applications in defence industry

NASA Astrophysics Data System (ADS)

Cadoni, Ezio; Dotta, Matteo; Forni, Daniele; Riganti, Gianmario; Kaufmann, Hanspeter

2015-09-01

The dynamic behaviour of armour steel in tension was investigated over a wide range of strain-rates on round specimens. The experiments were carried out by means of a Split Hopkinson Tensile Bar device and by a Hydro Pneumatic Machine. The target strain rate were set at the following six levels: 10-3, 5, 25, 100, 500 and 1000 s-1. Two material models were calibrated and used to replicate the experiments and to simulate blasting event on steel plate. Finally, the two responses are compared.

Impact of Climate Change on high and low flows across Great Britain: a temporal analysis and uncertainty assessment.

NASA Astrophysics Data System (ADS)

Beevers, Lindsay; Collet, Lila

2017-04-01

Over the past decade there have been significant challenges to water management posed by both floods and droughts. In the UK, since 2000 flooding has caused over £5Bn worth of damage, and direct costs from the recent drought (2011-12) are estimated to be between £70-165M, arising from impacts on public and industrial water supply. Projections of future climate change suggest an increase in temperature and precipitation trends which may exacerbate the frequency and severity of such hazards, but there is significant uncertainty associated with these projections. It thus becomes urgent to assess the possible impact of these changes on extreme flows and evaluate the uncertainties related to these projections, particularly changes in the seasonality of such hazards. This paper aims to assess the changes in seasonality of peak and low flows across Great Britain as a result of climate change. It is based on the Future Flow database; an 11-member ensemble of transient river flow projections from January 1951 to December 2098. We analyse the daily river flow over the baseline (1961-1990) and the 2080s (2069-2098) for 281 gauging stations. For each ensemble member, annual maxima (AMAX) and minima (AMIN) are extracted for both time periods for each gauging station. The month of the year the AMAX and AMIN occur respectively are recorded for each of the 30 years in the past and the future time periods. The uncertainty of the AMAX and AMIN occurrence temporally (monthly) is assessed across the 11 ensemble members, as well as the changes to this temporal signal between the baseline and the 2080s. Ultimately, this work gives a national picture (spatially) of high and low flows occurrence temporally and allows the assessment of possible changes in hydrological dynamics as a result of climate change in a statistical framework. Results will quantify the uncertainty related to the Climate Model parameters which are cascaded into the modelling chain. This study highlights the issues facing hydrological cycle management, due to changing spatial and temporal trends in order to anticipate and adapt to hydro-hazard changes in an uncertain context.

76 FR 67177 - Riverbank Hydro No. 18 LLC, Lock Hydro Friends Fund XXXV, FFP Project 57 LLC; Notice of Competing...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-31

...-000] Riverbank Hydro No. 18 LLC, Lock Hydro Friends Fund XXXV, FFP Project 57 LLC; Notice of Competing... Competing Applications On May 2, 2011, Riverbank Hydro No. 18 LLC (Riverbank), and on May 3, 2011, Lock... notice. Competing applications and notices of intent must meet the requirements of 18 CFR 4.36. Comments...

78 FR 22808 - Special Local Regulations; Pro Hydro-X Tour, Lake Dora; Tavares, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-17

...-AA08 Special Local Regulations; Pro Hydro-X Tour, Lake Dora; Tavares, FL AGENCY: Coast Guard, DHS... regulation on the waters on Lake Dora in Tavares, Florida during the Pro Hydro-X Tour, a series of high-speed... Hydro-X Tour, a series of high-speed personal watercraft races. The Pro Hydro-X Tour will be held on...

Integrating hydrologic modeling web services with online data sharing to prepare, store, and execute models in hydrology

NASA Astrophysics Data System (ADS)

Gan, T.; Tarboton, D. G.; Dash, P. K.; Gichamo, T.; Horsburgh, J. S.

2017-12-01

Web based apps, web services and online data and model sharing technology are becoming increasingly available to support research. This promises benefits in terms of collaboration, platform independence, transparency and reproducibility of modeling workflows and results. However, challenges still exist in real application of these capabilities and the programming skills researchers need to use them. In this research we combined hydrologic modeling web services with an online data and model sharing system to develop functionality to support reproducible hydrologic modeling work. We used HydroDS, a system that provides web services for input data preparation and execution of a snowmelt model, and HydroShare, a hydrologic information system that supports the sharing of hydrologic data, model and analysis tools. To make the web services easy to use, we developed a HydroShare app (based on the Tethys platform) to serve as a browser based user interface for HydroDS. In this integration, HydroDS receives web requests from the HydroShare app to process the data and execute the model. HydroShare supports storage and sharing of the results generated by HydroDS web services. The snowmelt modeling example served as a use case to test and evaluate this approach. We show that, after the integration, users can prepare model inputs or execute the model through the web user interface of the HydroShare app without writing program code. The model input/output files and metadata describing the model instance are stored and shared in HydroShare. These files include a Python script that is automatically generated by the HydroShare app to document and reproduce the model input preparation workflow. Once stored in HydroShare, inputs and results can be shared with other users, or published so that other users can directly discover, repeat or modify the modeling work. This approach provides a collaborative environment that integrates hydrologic web services with a data and model sharing system to enable model development and execution. The entire system comprised of the HydroShare app, HydroShare and HydroDS web services is open source and contributes to capability for web based modeling research.

Determining effective forecast horizons for multi-purpose reservoirs with short- and long-term operating objectives

NASA Astrophysics Data System (ADS)

Luchner, Jakob; Anghileri, Daniela; Castelletti, Andrea

2017-04-01

Real-time control of multi-purpose reservoirs can benefit significantly from hydro-meteorological forecast products. Because of their reliability, the most used forecasts range on time scales from hours to few days and are suitable for short-term operation targets such as flood control. In recent years, hydro-meteorological forecasts have become more accurate and reliable on longer time scales, which are more relevant to long-term reservoir operation targets such as water supply. While the forecast quality of such products has been studied extensively, the forecast value, i.e. the operational effectiveness of using forecasts to support water management, has been only relatively explored. It is comparatively easy to identify the most effective forecasting information needed to design reservoir operation rules for flood control but it is not straightforward to identify which forecast variable and lead time is needed to define effective hedging rules for operational targets with slow dynamics such as water supply. The task is even more complex when multiple targets, with diverse slow and fast dynamics, are considered at the same time. In these cases, the relative importance of different pieces of information, e.g. magnitude and timing of peak flow rate and accumulated inflow on different time lags, may vary depending on the season or the hydrological conditions. In this work, we analyze the relationship between operational forecast value and streamflow forecast horizon for different multi-purpose reservoir trade-offs. We use the Information Selection and Assessment (ISA) framework to identify the most effective forecast variables and horizons for informing multi-objective reservoir operation over short- and long-term temporal scales. The ISA framework is an automatic iterative procedure to discriminate the information with the highest potential to improve multi-objective reservoir operating performance. Forecast variables and horizons are selected using a feature selection technique. The technique determines the most informative combination in a multi-variate regression model to the optimal reservoir releases based on perfect information at a fixed objective trade-off. The improved reservoir operation is evaluated against optimal reservoir operation conditioned upon perfect information on future disturbances and basic reservoir operation using only the day of the year and the reservoir level. Different objective trade-offs are selected for analyzing resulting differences in improved reservoir operation and selected forecast variables and horizons. For comparison, the effective streamflow forecast horizon determined by the ISA framework is benchmarked against the performances obtained with a deterministic model predictive control (MPC) optimization scheme. Both the ISA framework and the MPC optimization scheme are applied to the real-world case study of Lake Como, Italy, using perfect streamflow forecast information. The principal operation targets for Lake Como are flood control and downstream water supply which makes its operation a suitable case study. Results provide critical feedback to reservoir operators on the use of long-term streamflow forecasts and to the hydro-meteorological forecasting community with respect to the forecast horizon needed from reliable streamflow forecasts.

Electrodeposition to construct free-standing chitosan/layered double hydroxides hydro-membrane for electrically triggered protein release.

PubMed

Zhao, Pengkun; Zhao, Yanan; Xiao, Ling; Deng, Hongbing; Du, Yumin; Chen, Yun; Shi, Xiaowen

2017-10-01

In this study, we report the electrodeposition of a chitosan/layered double hydroxides (LDHs) hydro-membrane for protein release triggered by an electrical signal. The electrodeposition was performed in a chitosan and insulin loaded LDHs suspension in the absence of salt. A free-standing chitosan/LDHs hydro-membrane was generated on the electrode with improved mechanical properties, which is dramatically different from the weak hydrogel deposited in the presence of salt. The amount of LDHs in the hydro-membrane affects the optical transmittance and multilayered structure of the hybrid membrane. Compared to the weak chitosan/LDHs hydrogel, the hydro-membrane has a higher insulin loading capacity and the release of insulin is relatively slow. By biasing electrical potentials to the hydro-membrane, the release behavior of insulin can be adjusted accordingly. In addition, the chitosan/LDHs hydro-membrane showed no toxicity to cells. Our results provide a facile method to construct a chitosan/LDHs hybrid multilayered hydro-membrane and suggest the great potential of the hydro-membrane in controlled protein release. Copyright © 2017 Elsevier B.V. All rights reserved.

Chemical spring water measurements coupled with 2d u.d.e.c hydromechanical modelling as an investigation methodology of water infiltration influence on large moving rock mass stability : application to the "la clapière" landslide (france, 06).

NASA Astrophysics Data System (ADS)

Cappa, F.; Guglielmi, Y.; Soukatchoff, V. M.; Mudry, J.; Bertrand, C.; Charmoille, A.

2003-04-01

We present an investigation method of water infiltration influence on Large Moving Rock Mass (LMRM) stability. In the case of huge unstable mountainous slopes, it has been clearly shown that the main driving of instability is gravity and that the major triggering and increasing factor is water located in interstices and fractures of rocks (Noverraz &al., 1998). More particularly, groundwater originates from a localized hydro-mechanical deformation inside fractures that can induce a generalized destabilization of large rock masses (Guglielmi, 1999). However, the understanding of groundwater mechanical effects on landslides and their neighbouring environment is rendered more complex given the large anisotropy of the rock mass as well as the difficulties to apply classic hydrogeological investigation methods in a moving environment. For these reasons, we developped an indirect investigation method based on chemical groundwater measurements coupled with a two-dimensional hydro-mechanical modelling with the Universal Distinct Element Code (UDEC) numerical program, taking the example of the La Clapière landslide (Alpes-Maritimes, France). The methodology we develop firstly establishes a hydro-mechanical conceptual scheme through the analysis of geological, hydrogeological, hydrogeochemistry and landslide velocity measurements. Then, a two-dimensional numerical modelling with UDEC was performed to test the influence of the locations and the intensities of water infiltrations on the hydro-mechanical behaviour of La Clapière’s slope. A geological and hydrogeological analysis reveals a perched saturated zone connected by large conducting-flow fractures to a basal aquifer. The correlations of spring water chemistry data and meteorological events on the slope highlight a large variability of groundwater transits in the slope in time (transit durations of 1 to 21 days) and in space. Infiltration transients correlate with landslide accelerations. Infiltration yields range between 0.4 and 0.8 l.s-1. The most intensive hydro-mechanical response of the landslide is linked to snowmelt in a stable area in the upper part of the slope located between 1800 and a 2500 m high. On the one hand modeling hydro-mechanical effects with UDEC considers a model corresponding to a slope without any unstable zone, and on the other hand, a model including a failure surface in order to simulate the current instability. In the two numerical tests, calculations show that the most unstabilizing water infiltration corresponds to water infiltrations located in the middle part of the slope for weak flow rates of 0.75 l.s-1. This is due to the water infiltration influence on the spatial distribution of strain fields. This result fits with field measurements. This methodology can easily be applied to the monitoring of landslide movements. As it gives relevant information on the spatial and temporal effects of various meteoric infiltrations, it can be applied to improve remedial protocols. This work was partly funded by the French National Program on Natural Hazards (PNRN) and Retina European Program. Guglielmi Y., 1999. Apport de la mesure des couplages hydromécaniques à la connaissance hydrogéologique des réservoirs fissurés. Habilitation à diriger des recherches, Université de Franche-Comté, E.A. 2642 Géosciences : Déformation, Écoulement, Transfert. 187 p. Noverraz F., BonnardC., Dupraz H., and Huguenin L., 1998. Grands glissements de versants et climat. Rapport final PNR 31, vdf hochschulverlag AG an der ETH Zürich, 314 p.

Relationships between substrate, surface characteristics, and vegetation in an initial ecosystem

NASA Astrophysics Data System (ADS)

Biber, P.; Seifert, S.; Zaplata, M. K.; Schaaf, W.; Pretzsch, H.; Fischer, A.

2013-12-01

We investigated surface and vegetation dynamics in the artificial initial ecosystem "Chicken Creek" (Lusatia, Germany) in the years 2006-2011 across a wide spectrum of empirical data. We scrutinized three overarching hypotheses concerning (1) the relations between initial geomorphological and substrate characteristics with surface structure and terrain properties, (2) the effects of the latter on the occurrence of grouped plant species, and (3) vegetation density effects on terrain surface change. Our data comprise and conflate annual vegetation monitoring results, biennial terrestrial laser scans (starting in 2008), annual groundwater levels, and initially measured soil characteristics. The empirical evidence mostly confirms the hypotheses, revealing statistically significant relations for several goal variables: (1) the surface structure properties, local rill density, local relief energy and terrain surface height change; (2) the cover of different plant groups (annual, herbaceous, grass-like, woody, Fabaceae), and local vegetation height; and (3) terrain surface height change showed significant time-dependent relations with a variable that proxies local plant biomass. Additionally, period specific effects (like a calendar-year optimum effect for the occurrence of Fabaceae) were proven. Further and beyond the hypotheses, our findings on the spatiotemporal dynamics during the system's early development grasp processes which generally mark the transition from a geo-hydro-system towards a bio-geo-hydro system (weakening geomorphology effects on substrate surface dynamics, while vegetation effects intensify with time), where pure geomorphology or substrate feedbacks are changing into vegetation-substrate feedback processes.

Hydro-meteorological trends in the Gidabo catchment of the Rift Valley Lakes Basin of Ethiopia

NASA Astrophysics Data System (ADS)

Belihu, Mamuye; Abate, Brook; Tekleab, Sirak; Bewket, Woldeamlak

2018-04-01

The global and regional variability and changes of climate and stream flows are likely to have significant influence on water resource availability. The magnitude and impacts of climate variability and change differs spatially and temporally. This study examines the long term hydroclimatic changes, analyses of the hydro-climate variability and detect whether there exist significant trend or not in the Gidabo catchment, rift valley lakes basin of Ethiopia. Precipitation, temperature and stream flow time series data were used in monthly, seasonal and annual time scales. The precipitation and temperature data span is between 1982 and 2014 and that of stream flow is between 1976 and 2006. To detect trends the analysis were done by using Mann Kendal (MK), Sen's graphical method and to detect change point using the Pettit test. The comparison of trend analysis between MK trend test and Sen graphical method results depict mostly similar pattern. The annual rainfall trends exhibited a significant decrease by about 12 mm per year in the upstream, which is largely driven by the significant decrease in the peak season rainfall. The Pettit test revealed that the years 1997 and 2007 were the change points. It is noted that the rise of temperature over a catchment might have decreased the availability of soil moisture which resulted in less runoff. The temperature analyses also revealed that the catchment was getting warmer; particularly in the upstream. The minimum temperature trend showed a significant increase about 0.08°c per annum. There is generally a decreasing trend in stream flow. The monthly stream flow also exhibited a decreasing trend in February, March and September. The decline in annual and seasonal rainfall and the increase in temperature lead to more evaporation and directly affecting the stream flow negatively. This trend compounded with the growth of population and increasing demand for irrigation water exacerbates the competing demand for water resources. It thus calls for prudence in devising appropriate intervention in the planning and sustainable development of the basin water resources.

Capturing poromechanical coupling effects of the reactive fracturing process in porous rock via a DEM-network model

NASA Astrophysics Data System (ADS)

Ulven, Ole Ivar; Sun, WaiChing

2016-04-01

Fluid transport in a porous medium has important implications for understanding natural geological processes. At a sufficiently large scale, a fluid-saturated porous medium can be regarded as a two-phase continuum, with the fluid constituent flowing in the Darcian regime. Nevertheless, a fluid mediated chemical reaction can in some cases change the permeability of the rock locally: Mineral dissolution can cause increased permeability, whereas mineral precipitation can reduce the permeability. This might trigger a complicated hydro-chemo-mechanical coupling effect that causes channeling of fluids or clogging of the system. If the fluid is injected or produced at a sufficiently high rate, the pressure might increase enough to cause the onset and propagation of fractures. Fractures in return create preferential flow paths that enhance permeability, localize fluid flow and chemical reaction, prevent build-up of pore pressure and cause anisotropy of the hydro-mechanical responses of the effective medium. This leads to a complex coupled process of solid deformation, chemical reaction and fluid transport enhanced by the fracture formation. In this work, we develop a new coupled numerical model to study the complexities of feedback among fluid pressure evolution, fracture formation and permeability changes due to a chemical process in a 2D system. We combine a discrete element model (DEM) previously used to study a volume expanding process[1, 2] with a new fluid transport model based on poroelasticity[3] and a fluid-mediated chemical reaction that changes the permeability of the medium. This provides new insights into the hydro-chemo-mechanical process of a transforming porous medium. References [1] Ulven, O. I., Storheim, H., Austrheim, H., and Malthe-Sørenssen, A. "Fracture Initiation During Volume Increasing Reactions in Rocks and Applications for CO2 Sequestration", Earth Planet. Sc. Lett. 389C, 2014a, pp. 132 - 142, doi:10.1016/j.epsl.2013.12.039. [2] Ulven, O. I., Jamtveit, B., and Malthe-Sørenssen, A., "Reaction-driven fracturing of porous rock", J. Geophys. Res. Solid Earth 119, 2014b, doi:10.1002/2014JB011102. [3] Ulven, O. I., and Sun, W.C., "A locally mass-conserving dual-graph lattice model for fluid-driven fracture", in prep.

Sulfur transformations in pilot-scale constructed wetland treating high sulfate-containing contaminated groundwater: a stable isotope assessment.

PubMed

Wu, Shubiao; Jeschke, Christina; Dong, Renjie; Paschke, Heidrun; Kuschk, Peter; Knöller, Kay

2011-12-15

Current understanding of the dynamics of sulfur compounds inside constructed wetlands is still insufficient to allow a full description of processes involved in sulfur cycling. Experiments in a pilot-scale horizontal subsurface flow constructed wetland treating high sulfate-containing contaminated groundwater were carried out. Application of stable isotope approach combined with hydro-chemical investigations was performed to evaluate the sulfur transformations. In general, under inflow concentration of about 283 mg/L sulfate sulfur, sulfate removal was found to be about 21% with a specific removal rate of 1.75 g/m(2)·d. The presence of sulfide and elemental sulfur in pore water about 17.3 mg/L and 8.5 mg/L, respectively, indicated simultaneously bacterial sulfate reduction and re-oxidation. 70% of the removed sulfate was calculated to be immobilized inside the wetland bed. The significant enrichment of (34)S and (18)O in dissolved sulfate (δ(34)S up to 16‰, compared to average of 5.9‰ in the inflow, and δ(18)O up to 13‰, compared to average of 6.9‰ in the inflow) was observed clearly correlated to the decrease of sulfate loads along the flow path through experimental wetland bed. This enrichment also demonstrated the occurrence of bacterial sulfate reduction as well as demonstrated by the presence of sulfide in the pore water. Moreover, the integral approach shows that bacterial sulfate reduction is not the sole process controlling the isotopic composition of dissolved sulfate in the pore water. The calculated apparent enrichment factor (ɛ = -22‰) for sulfur isotopes from the δ(34)S vs. sulfate mass loss was significantly smaller than required to produce the observed difference in δ(34)S between sulfate and sulfide. It indicated some potential processes superimposing bacterial sulfate reduction, such as direct re-oxidation of sulfide to sulfate by oxygen released from plant roots and/or bacterial disproportionation of elemental sulfur. Furthermore, 41% of residual sulfate was calculated to be from sulfide re-oxidation, which demonstrated that the application of stable isotope approach combined with the common hydro-chemical investigations is not only necessary for a general qualitative evaluation of sulfur transformations in constructed wetlands, but also leads to a quantitative description of intermediate processes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Stefan blowing effects on MHD bioconvection flow of a nanofluid in the presence of gyrotactic microorganisms with active and passive nanoparticles flux

NASA Astrophysics Data System (ADS)

Giri, Shib Sankar; Das, Kalidas; Kundu, Prabir Kumar

2017-02-01

The present paper investigates the effect of Stefan blowing on the hydro-magnetic bioconvection of a water-based nanofluid flow containing gyrotactic microorganisms through a permeable surface. Also we studied both actively and passively the controlled flux of nanoparticles and the effect of a surface slip at the wall. We adopt a similarity approach to reduce the leading partial differential equations into ordinary differential equations along with two separate boundary conditions (active and passive) and solve the resulting equations numerically by employing the RK-4 method through the shooting technique to perform the flow analysis. Discussions on the effect of emerging flow parameter on the flow characteristic are made properly through graphs and charts. We observed that the effects of the traditional Lewis number and suction/blowing parameter on temperature distribution and microorganism concentration are converse to each other. A fair result comparison of the present paper with formerly obtained results is given.

A strong shock tube problem calculated by different numerical schemes

NASA Astrophysics Data System (ADS)

Lee, Wen Ho; Clancy, Sean P.

1996-05-01

Calculated results are presented for the solution of a very strong shock tube problem on a coarse mesh using (1) MESA code, (2) UNICORN code, (3) Schulz hydro, and (4) modified TVD scheme. The first two codes are written in Eulerian coordinates, whereas methods (3) and (4) are in Lagrangian coordinates. MESA and UNICORN codes are both of second order and use different monotonic advection method to avoid the Gibbs phenomena. Code (3) uses typical artificial viscosity for inviscid flow, whereas code (4) uses a modified TVD scheme. The test problem is a strong shock tube problem with a pressure ratio of 109 and density ratio of 103 in an ideal gas. For no mass-matching case, Schulz hydro is better than TVD scheme. In the case of mass-matching, there is no difference between them. MESA and UNICORN results are nearly the same. However, the computed positions such as the contact discontinuity (i.e. the material interface) are not as accurate as the Lagrangian methods.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, W.H.; Clancy, S.P.

Calculated results are presented for the solution of a very strong shock tube problem on a coarse mesh using (1) MESA code, (2) UNICORN code, (3) Schulz hydro, and (4) modified TVD scheme. The first two codes are written in Eulerian coordinates, whereas methods (3) and (4) are in Lagrangian coordinates. MESA and UNICORN codes are both of second order and use different monotonic advection method to avoid the Gibbs phenomena. Code (3) uses typical artificial viscosity for inviscid flow, whereas code (4) uses a modified TVD scheme. The test problem is a strong shock tube problem with a pressuremore » ratio of 10{sup 9} and density ratio of 10{sup 3} in an ideal gas. For no mass-matching case, Schulz hydro is better than TVD scheme. In the case of mass-matching, there is no difference between them. MESA and UNICORN results are nearly the same. However, the computed positions such as the contact discontinuity (i.e. the material interface) are not as accurate as the Lagrangian methods. {copyright} {ital 1996 American Institute of Physics.}« less

The fractal-multifractal method and temporal resolution: Application to precipitation and streamflow

NASA Astrophysics Data System (ADS)

Maskey, M.; Puente, C. E.; Sivakumar, B.

2017-12-01

In the past, we have established that the deterministic fractal-multifractal (FM) method is a promising geometric tool to analyze hydro-climatic variables, such as precipitation, river flow, and temperature. In this study, we address the issue of temporal resolution to advance the suitability and usefulness of the FM approach in hydro-climate. Specifically, we elucidate the evolution of FM geometric parameters as computed at different time scales ranging from a day to a month (30-day) in increments of a day. For this purpose, both rainfall and river discharge records at Sacramento, California gathered over a year are encoded at different time scales. The analysis reveals that: (a) the FM approach yields faithful encodings of both kinds of data sets at the resolutions considered with reasonably small errors; and (b) the "best" FM parameters ultimately converge when the resolution is increased, thus allowing visualizing both hydrologic attributes. By addressing the scalability of the geometric patterns, these results further advance the suitability of the FM approach.

An investigation into the potential of low head hydro power in Northern Ireland for the production of electricity

NASA Astrophysics Data System (ADS)

Redpath, David; Ward, Michael J.

2017-07-01

The maximum exploitable potential for low head hydroelectric sites (gross head≤10 m) in Northern Ireland (NI) was determined as 12.07 MW using a simple payback analysis for 304 potential sites investigated to derive a classification scheme in terms of economic viability. A techno-economic analysis with validated numerical models from previous research estimated the capital investment required for the development of a hydroelectric plant, using the low head Michell-Banki cross flow turbine, for the 304 sites investigated. The number of potentially viable sites in NI for low head hydro ranged from 198 to 286 with an estimated installed capacity ranging from 11.95 to 12.05 MW. Sites with a limited installed capacity were not economically viable unless increased government support in the form of longer term (25-50 years) low interest loans as well as the current (Renewables Obligations Certificates) Renewables Obligation Certificates scheme is provided and sustained.

Friction Hydro-Pillar Processing of a High Carbon Steel: Joint Structure and Properties

NASA Astrophysics Data System (ADS)

Kanan, Luis Fernando; Vicharapu, Buchibabu; Bueno, Antonio Fernando Burkert; Clarke, Thomas; De, Amitava

2018-04-01

A coupled experimental and theoretical study is reported here on friction hydro-pillar processing of AISI 4140 steel, which is a novel solid-state joining technique to repair and fill crack holes in thick-walled components by an external stud. The stud is rotated and forced to fill a crack hole by plastic flow. During the process, frictional heating occurs along the interface of the stud and the wall of crack hole leading to thermal softening of the stud that eases its plastic deformation. The effect of the stud force, its rotational speed and the total processing time on the rate of heat generation and resulting transient temperature field is therefore examined to correlate the processing variables with the joint structure and properties in a systematic and quantitative manner, which is currently scarce in the published literature. The results show that a gentler stud force rate and greater processing time can promote proper filling of the crack hole and facilitate a defect-free joint between the stud and original component.

Study of the Interrelationships between Minimum Flow Release Policies and Hydroelectric Power Development in New England.

DTIC Science & Technology

1981-06-01

available information from Public Utilities comaissions responsible for establishing PURPA rates in each state. 1.4 PRINCIPAL FINDINGS The direct effect all... PURPA rates. However, many of those categorized as private and public developers are private and public utilities. This reflects the interest in hydro...The Public Utility Regulatory Policies Act ( PURPA ) of 1978 empowered FERC to prescribe rules requiring utilities to purchase power from and sell power

Coupled Hydro-mechanical process of natural fracture network formation in sedimentary basin

NASA Astrophysics Data System (ADS)

Ouraga, zady; Guy, Nicolas; Pouya, amade

2017-04-01

In sedimentary basin numerous phenomenon depending on the geological time span and its history can lead to a decrease in effective stress and therefore result in fracture initiation. Thus, during its formation, under certain conditions, natural fracturing and fracture network formation can occur in various context such as under erosion, tectonic loading and the compaction disequilibrium due to significant sedimentation rate. In this work, natural fracture network and fracture spacing induced by significant sedimentation rate is studied considering mode I fracture propagation, using a coupled hydro-mechanical numerical methods. Assumption of vertical fracture can be considered as a relevant hypothesis in our case of low ratio of horizontal total stress to vertical stress. A particular emphasis is put on synthetic geological structure on which a constant sedimentation rate is imposed on its top. This synthetic geological structure contains defects initially closed and homogeneously distributed. The Fractures are modeled with a constitutive model undergoing damage and the flow is described by poiseuille's law. The damage parameter affects both the mechanical and the hydraulic opening of the fracture. For the numerical simulations, the code Porofis based on finite element modeling is used, fractures are taken into account by cohesive model and the flow is described by Poiseuille's law. The effect of several parameters is also studied and the analysis lead to a fracture network and fracture spacing criterion for basin modeling.

Hydrologic Derivatives for Modeling and Analysis—A new global high-resolution database

USGS Publications Warehouse

Verdin, Kristine L.

2017-07-17

The U.S. Geological Survey has developed a new global high-resolution hydrologic derivative database. Loosely modeled on the HYDRO1k database, this new database, entitled Hydrologic Derivatives for Modeling and Analysis, provides comprehensive and consistent global coverage of topographically derived raster layers (digital elevation model data, flow direction, flow accumulation, slope, and compound topographic index) and vector layers (streams and catchment boundaries). The coverage of the data is global, and the underlying digital elevation model is a hybrid of three datasets: HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales), GMTED2010 (Global Multi-resolution Terrain Elevation Data 2010), and the SRTM (Shuttle Radar Topography Mission). For most of the globe south of 60°N., the raster resolution of the data is 3 arc-seconds, corresponding to the resolution of the SRTM. For the areas north of 60°N., the resolution is 7.5 arc-seconds (the highest resolution of the GMTED2010 dataset) except for Greenland, where the resolution is 30 arc-seconds. The streams and catchments are attributed with Pfafstetter codes, based on a hierarchical numbering system, that carry important topological information. This database is appropriate for use in continental-scale modeling efforts. The work described in this report was conducted by the U.S. Geological Survey in cooperation with the National Aeronautics and Space Administration Goddard Space Flight Center.

Retrospective evaluation of continental-scale streamflow nudging with WRF-Hydro National Water Model V1

NASA Astrophysics Data System (ADS)

McCreight, J. L.; Wu, Y.; Gochis, D.; Rafieeinasab, A.; Dugger, A. L.; Yu, W.; Cosgrove, B.; Cui, Z.; Oubeidillah, A.; Briar, D.

2016-12-01

The streamflow (discharge) data assimilation capability in version 1 of the National Water Model (NWM; a WRF-Hydro configuration) is applied and evaluated in a 5-year (2011-2015) retrospective study using NLDAS2 forcing data over CONUS. This talk will describe the NWM V1 operational nudging (continuous-time) streamflow data assimilation approach, its motivation, and its relationship to this retrospective evaluation. Results from this study will provide a an analysis-based (not forecast-based) benchmark for streamflow DA in the NWM. The goal of the assimilation is to reduce discharge bias and improve channel initial conditions for discharge forecasting (though forecasts are not considered here). The nudging method assimilates discharge observations at nearly 7,000 USGS gages (at frequency up to 1/15 minutes) to produce a (univariate) discharge reanalysis (i.e. this is the only variable affected by the assimilation). By withholding 14% nested gages throughout CONUS in a separate validation run, we evaluate the downstream impact of assimilation at upstream gages. Based on this sample, we estimate the skill of the streamflow reanalysis at ungaged locations and examine factors governing the skill of the assimilation. Comparison of assimilation and open-loop runs is presented. Performance of DA under both high and low flow regimes and selected flooding events is examined. Preliminary evaluation of nudging parameter sensitivity and its relationship to flow regime will be presented.

Impact of dam-building on marine life

NASA Astrophysics Data System (ADS)

Pandian, T. J.

1980-03-01

Dam-building across naturally flowing rivers tends to decrease discharge of surplus water into the sea, reduce nutrient concentration in estuaries and coastal waters, and diminish plankton blooms as well as fish landings. Depletion of nutrients and organic matter along with reduced mud and silt deposition affect benthic life on the continental shelf. Reduced mud and silt deposition leads to coastal retreat. Dams, especially those constructed for hydro-electric purposes, hinder migration of fishes and decapods. Discharge from dams can create barriers at high or low flows, cause delays, disrupt normal behavioural routine and change the travel speed of migratory animals. Where all spawners of a given population are frequently kept away from the breeding site, the population faces extinction.

76 FR 67174 - Arkansas Electric Cooperative Corp., Riverbank Hydro No. 9 LLC, Solia 3 Hydroelectric LLC, Lock...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-31

... Hydroelectric LLC, Lock Hydro Friends Fund XLV, FFP Project 2 LLC; Notice of Competing Preliminary Permit... (Riverbank) and Solia 3 Hydroelectric LLC (Solia) and on May 3, 2011, Lock Hydro Friends Fund XLV (Lock Hydro...

Processus de modelisation et etude des orages geomagnetiques dans les reseaux electriques: Impact sur le reseau de transport d'Hydro-Quebec

NASA Astrophysics Data System (ADS)

Abdellaoui, Amr

This research project presents a complete modelling process of the effects of GIC on Hydro-Quebec power system network for system planning studies. The advantage of the presented method is that it enables planning engineers to simulate the effects of geomagnetic disturbances on the Hydro-Quebec System under different conditions and contingencies within reasonable calculation time frame. This modelling method of GIC in electric power systems has been applied to the Hydro-Quebec System. An equivalent HQ DC model has been achieved. A numerical calculation method of DC sources from a non-uniform geoelectric field has been developed and implemented on HQ DC model. Harmonics and increased reactive power losses of saturated transformers have been defined as a function of GIC through a binary search algorithm using a chosen HQ magnetization curve. The evolution in time of each transformer saturation according to its effective GIC has been evaluated using analytical formulas. The reactive power losses of saturated transformers have been modeled in PSS/E[1] HQ network as constant reactive current loads assigned to the corresponding transformer buses. Finally, time domain simulations have been performed with PSS/E taking into account transformer saturation times. This has been achieved by integrating HQ DC model results and analytical calculations results of transformer saturation times into an EMTP load model. An interface has been used to link EMTP load model to HQ PSS/E network. Different aspects of GIC effects on the Hydro-Quebec system have been studied, including the influence of uniform and non-uniform geoelectric fields, the comparison of reactive power losses of the 735kV HQ system with those of Montreal network, the risks to voltage levels and the importance of reactive power dynamic reserve. This dissertation presents a new GIC modelling approach for power systems for planning and operations purposes. This methodology could be further enhanced, particularly, the aspect regarding the transformer saturation times. Hence more research remains to be pursued in this area.

Copula Multivariate analysis of Gross primary production and its hydro-environmental driver; A BIOME-BGC model applied to the Antisana páramos

NASA Astrophysics Data System (ADS)

Minaya, Veronica; Corzo, Gerald; van der Kwast, Johannes; Galarraga, Remigio; Mynett, Arthur

2014-05-01

Simulations of carbon cycling are prone to uncertainties from different sources, which in general are related to input data, parameters and the model representation capacities itself. The gross carbon uptake in the cycle is represented by the gross primary production (GPP), which deals with the spatio-temporal variability of the precipitation and the soil moisture dynamics. This variability associated with uncertainty of the parameters can be modelled by multivariate probabilistic distributions. Our study presents a novel methodology that uses multivariate Copulas analysis to assess the GPP. Multi-species and elevations variables are included in a first scenario of the analysis. Hydro-meteorological conditions that might generate a change in the next 50 or more years are included in a second scenario of this analysis. The biogeochemical model BIOME-BGC was applied in the Ecuadorian Andean region in elevations greater than 4000 masl with the presence of typical vegetation of páramo. The change of GPP over time is crucial for climate scenarios of the carbon cycling in this type of ecosystem. The results help to improve our understanding of the ecosystem function and clarify the dynamics and the relationship with the change of climate variables. Keywords: multivariate analysis, Copula, BIOME-BGC, NPP, páramos

Real-time co-simulation of adjustable-speed pumped storage hydro for transient stability analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohanpurkar, Manish; Ouroua, Abdelhamid; Hovsapian, Rob

Pumped storage hydro (PSH) based generation of electricity is a proven grid level storage technique. A new configuration i.e., adjustable speed PSH (AS-PSH) power plant is modeled and discussed in this paper. Hydrodynamic models are created using partial differential equations and the governor topology adopted from an existing, operational AS-PSH unit. Physics-based simulation of both hydrodynamics and power system dynamics has been studied individually in the past. This article demonstrates a co-simulation of an AS-PSH unit between penstock hydrodynamics and power system events in a real-time environment. Co-simulation provides an insight into the dynamic and transient operation of AS-PSH connectedmore » to a bulk power system network. The two modes of AS-PSH operation presented in this paper are turbine and pump modes. A general philosophy of operating in turbine mode is prevalent in the field when the prices of electricity are high and in the pumping mode when prices are low. However, recently there is renewed interest in operating PSH to also provide ancillary services. A real-time co-simulation at sub-second regime of AS-PSH connected to the IEEE 14 bus test system is performed using digital real-time simulator and the results are discussed.« less

Real-time co-simulation of adjustable-speed pumped storage hydro for transient stability analysis

DOE PAGES

Mohanpurkar, Manish; Ouroua, Abdelhamid; Hovsapian, Rob; ...

2017-09-12

Pumped storage hydro (PSH) based generation of electricity is a proven grid level storage technique. A new configuration i.e., adjustable speed PSH (AS-PSH) power plant is modeled and discussed in this paper. Hydrodynamic models are created using partial differential equations and the governor topology adopted from an existing, operational AS-PSH unit. Physics-based simulation of both hydrodynamics and power system dynamics has been studied individually in the past. This article demonstrates a co-simulation of an AS-PSH unit between penstock hydrodynamics and power system events in a real-time environment. Co-simulation provides an insight into the dynamic and transient operation of AS-PSH connectedmore » to a bulk power system network. The two modes of AS-PSH operation presented in this paper are turbine and pump modes. A general philosophy of operating in turbine mode is prevalent in the field when the prices of electricity are high and in the pumping mode when prices are low. However, recently there is renewed interest in operating PSH to also provide ancillary services. A real-time co-simulation at sub-second regime of AS-PSH connected to the IEEE 14 bus test system is performed using digital real-time simulator and the results are discussed.« less

75 FR 48664 - Turnbull Hydro, LLC; Notice of Availability of Environmental Assessment

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-11

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 12597-021; Project No. 12598-019] Turnbull Hydro, LLC; Notice of Availability of Environmental Assessment August 4, 2010. In... Register [FR] 47897), the Office of Energy Projects has reviewed Turnbull Hydro, LLC's (Turnbull Hydro's...

77 FR 55466 - Barren River Lake Hydro LLC; Notice Soliciting Scoping Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-10

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13022-003] Barren River Lake Hydro LLC; Notice Soliciting Scoping Comments Take notice that the following hydroelectric..., 2012. d. Applicant: Barren River Lake Hydro LLC (Barren River Hydro). e. Name of Project: Barren River...

THERMO-HYDRO-MECHANICAL MODELING OF WORKING FLUID INJECTION AND THERMAL ENERGY EXTRACTION IN EGS FRACTURES AND ROCK MATRIX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robert Podgorney; Chuan Lu; Hai Huang

2012-01-01

Development of enhanced geothermal systems (EGS) will require creation of a reservoir of sufficient volume to enable commercial-scale heat transfer from the reservoir rocks to the working fluid. A key assumption associated with reservoir creation/stimulation is that sufficient rock volumes can be hydraulically fractured via both tensile and shear failure, and more importantly by reactivation of naturally existing fractures (by shearing), to create the reservoir. The advancement of EGS greatly depends on our understanding of the dynamics of the intimately coupled rock-fracture-fluid-heat system and our ability to reliably predict how reservoirs behave under stimulation and production. Reliable performance predictions ofmore » EGS reservoirs require accurate and robust modeling for strongly coupled thermal-hydrological-mechanical (THM) processes. Conventionally, these types of problems have been solved using operator-splitting methods, usually by coupling a subsurface flow and heat transport simulators with a solid mechanics simulator via input files. An alternative approach is to solve the system of nonlinear partial differential equations that govern multiphase fluid flow, heat transport, and rock mechanics simultaneously, using a fully coupled, fully implicit solution procedure, in which all solution variables (pressure, enthalpy, and rock displacement fields) are solved simultaneously. This paper describes numerical simulations used to investigate the poro- and thermal- elastic effects of working fluid injection and thermal energy extraction on the properties of the fractures and rock matrix of a hypothetical EGS reservoir, using a novel simulation software FALCON (Podgorney et al., 2011), a finite element based simulator solving fully coupled multiphase fluid flow, heat transport, rock deformation, and fracturing using a global implicit approach. Investigations are also conducted on how these poro- and thermal-elastic effects are related to fracture permeability evolution.« less

Contribution of piezometric measurement to knowledge and management of low water levels: examples on the chalk aquifer in the Champagne Ardennes region

NASA Astrophysics Data System (ADS)

Stollsteiner, P.; Bessiere, H.; Nicolas, J.; Allier, D.; Berthet, O.

2015-04-01

This article is based on a BRGM study on piezometric indicators, threshold values of discharge and groundwater levels for the assessment of potentially-exploitable water resources of chalky watersheds. A method for estimating low water levels based on groundwater levels is presented from three examples representing chalk aquifers with different cycles: annual, combined and interannual. The first is located in Picardy and the two others in the Champagne-Ardennes region. Piezometers with annual cycles, used in these examples, are supposed to be representative of the aquifer hydro-dynamics. Except for multi-annual systems, the analysis between discharge measurements at a hydrometric station and groundwater levels measured at a piezometer representative of the main aquifer, leads to relatively precise and satisfactory relationships within a chalky context. These relationships may be useful for monitoring, validation, extension or reconstruction of the low water flow data. On the one hand, they allow definition of the piezometric levels corresponding to the different alert thresholds of river discharges. On the other hand, they clarify the proportions of low surface water flow from runoff or drainage of the aquifer. Finally, these correlations give an assessment of the minimum flow for the coming weeks. However, these correlations cannot be used to optimize the value of the exploitable water resource because it seems to be difficult to integrate the value of the effective rainfall that could occur during the draining period. Moreover, in the case of multi-annual systems, the solution is to attempt a comprehensive system modelling and, if it is satisfactory, using the simulated values to get rid of parasites or running the model for forecasting purposes.

Modeling of fluid injection and withdrawal induced fault activation using discrete element based hydro-mechanical and dynamic coupled simulator

NASA Astrophysics Data System (ADS)

Yoon, Jeoung Seok; Zang, Arno; Zimmermann, Günter; Stephansson, Ove

2016-04-01

Operation of fluid injection into and withdrawal from the subsurface for various purposes has been known to induce earthquakes. Such operations include hydraulic fracturing for shale gas extraction, hydraulic stimulation for Enhanced Geothermal System development and waste water disposal. Among these, several damaging earthquakes have been reported in the USA in particular in the areas of high-rate massive amount of wastewater injection [1] mostly with natural fault systems. Oil and gas production have been known to induce earthquake where pore fluid pressure decreases in some cases by several tens of Mega Pascal. One recent seismic event occurred in November 2013 near Azle, Texas where a series of earthquakes began along a mapped ancient fault system [2]. It was studied that a combination of brine production and waste water injection near the fault generated subsurface pressures sufficient to induced earthquakes on near-critically stressed faults. This numerical study aims at investigating the occurrence mechanisms of such earthquakes induced by fluid injection [3] and withdrawal by using hydro-geomechanical coupled dynamic simulator (Itasca's Particle Flow Code 2D). Generic models are setup to investigate the sensitivity of several parameters which include fault orientation, frictional properties, distance from the injection well to the fault, amount of fluid withdrawal around the injection well, to the response of the fault systems and the activation magnitude. Fault slip movement over time in relation to the diffusion of pore pressure is analyzed in detail. Moreover, correlations between the spatial distribution of pore pressure change and the locations of induced seismic events and fault slip rate are investigated. References [1] Keranen KM, Weingarten M, Albers GA, Bekins BA, Ge S, 2014. Sharp increase in central Oklahoma seismicity since 2008 induced by massive wastewater injection, Science 345, 448, DOI: 10.1126/science.1255802. [2] Hornbach MJ, DeShon HR, Ellsworth WL, Stump BW, Hayward C, Frohlich C, Oldham HR, Olson JE, Magnani MB, Brokaw C, Luetgert JH, 2015, Causal factors for seismicity near Azle, Texas, nature communications 6:6728, DOI: 10.1038/ncomms7728 [3] Yoon JS, Zimmermann G, Zang A, Stephansson O, 2015, Discrete element modeling of fluid injection-induced seismicity and activation of nearby fault, Can Geotech J 52: 1457-1465, DOI: 10.1139/cgj-2014-0435.

Attempting to link hydro-morphology, transient storage and metabolism in streams: Insights from reactive tracer experiments

NASA Astrophysics Data System (ADS)

Kurz, Marie J.; Schmidt, Christian; Blaen, Phillip; Knapp, Julia L. A.; Drummond, Jennifer D.; Martí, Eugenia; Zarnetske, Jay P.; Ward, Adam S.; Krause, Stefan

2016-04-01

In-stream transient storage zones, including the hyporheic zone and vegetation beds, can be hotspots of biogeochemical processing in streams, enhancing ecosystem functions such as metabolism and nutrient uptake. The spatio-temporal dynamics and reactivity of these storage zones are influenced by multiple factors, including channel geomorphology, substrate composition and hydrology, and by anthropogenic modifications to flow regimes and nutrient loads. Tracer injections are a commonly employed method to evaluate solute transport and transient storage in streams; however, reactive tracers are needed to differentiate between metabolically active and inactive transient storage zones. The reactive stream tracer resazurin (Raz), a weakly fluorescent dye which irreversibly transforms to resorufin (Rru) under mildly reducing conditions, provides a proxy for aerobic respiration and an estimate of the metabolic activity associated with transient storage zones. Across a range of lotic ecosystems, we try to assess the influence of stream channel hydro-morphology, morphologic heterogeneity, and substrate type on reach (103 m) and sub-reach (102 m) scale transient storage, respiration, and nutrient uptake. To do so, we coupled injections of Raz and conservative tracers (uranine and/or salt) at each study site. The study sites included: vegetated mesocosms controlled for water depth; vegetated and un-vegetated sediment-filled mesocosms fed by waste-water effluent; a contrasting sand- vs. gravel-bedded lowland stream (Q = 0.08 m3/s); and a series of upland streams with varying size (Q = 0.1 - 1.5 m3/s) and prevalence of morphologic features. Continuous time-series of tracer concentrations were recorded using in-situ fluorometers and EC loggers. At the stream sites, time-series were recorded at multiple downstream locations in order to resolve sub-reach dynamics. Analyses yielded highly variable transport metrics and Raz-Rru transformation between study sites and between sub-reaches within stream sites. Higher Raz-Rru transformation rates were typically observed in smaller streams, in sub-reaches with higher prevalence of morphologic features known to promote hyporheic exchange, and in mesocosms with higher water depth, vegetation density and retention time. However, relationships between transformation rates and common metrics of transient storage were not consistent among study cases, indicating the existence of yet unrealized complexities in the relationships between water and solute transport and metabolism. Further insights were also gained related to the utility of Raz and improved tracer test practices.

Using a coupled hydro-mechanical fault model to better understand the risk of induced seismicity in deep geothermal projects

NASA Astrophysics Data System (ADS)

Abe, Steffen; Krieger, Lars; Deckert, Hagen

2017-04-01

The changes of fluid pressures related to the injection of fluids into the deep underground, for example during geothermal energy production, can potentially reactivate faults and thus cause induced seismic events. Therefore, an important aspect in the planning and operation of such projects, in particular in densely populated regions such as the Upper Rhine Graben in Germany, is the estimation and mitigation of the induced seismic risk. The occurrence of induced seismicity depends on a combination of hydraulic properties of the underground, mechanical and geometric parameters of the fault, and the fluid injection regime. In this study we are therefore employing a numerical model to investigate the impact of fluid pressure changes on the dynamics of the faults and the resulting seismicity. The approach combines a model of the fluid flow around a geothermal well based on a 3D finite difference discretisation of the Darcy-equation with a 2D block-slider model of a fault. The models are coupled so that the evolving pore pressure at the relevant locations of the hydraulic model is taken into account in the calculation of the stick-slip dynamics of the fault model. Our modelling approach uses two subsequent modelling steps. Initially, the fault model is run by applying a fixed deformation rate for a given duration and without the influence of the hydraulic model in order to generate the background event statistics. Initial tests have shown that the response of the fault to hydraulic loading depends on the timing of the fluid injection relative to the seismic cycle of the fault. Therefore, multiple snapshots of the fault's stress- and displacement state are generated from the fault model. In a second step, these snapshots are then used as initial conditions in a set of coupled hydro-mechanical model runs including the effects of the fluid injection. This set of models is then compared with the background event statistics to evaluate the change in the probability of seismic events. The event data such as location, magnitude, and source characteristics can be used as input for numerical wave propagation models. This allows the translation of seismic event statistics generated by the model into ground shaking probabilities.

Hydro-meteorological functioning of the Eastern Andean Tropical Montane Cloud Forests: Insight from a paired catchment study in the Orinoco river basin highlands

NASA Astrophysics Data System (ADS)

Ramirez, Beatriz; Teuling, Adriaan J.; Ganzeveld, Laurens; Leemans, Rik

2016-04-01

Tropical forests regulate large scale precipitation patterns and catchment-scale streamflow, while tropical mountains influence runoff by orographic effects and snowmelt. Along tropical elevation gradients, these climate/ecosystem/hydrological interactions are specific and heterogeneous. These interactions are poorly understood and represented in hydro-meteorological monitoring networks and regional or global earth system models. A typical case are the South American Tropical Montane Cloud Forests (TMCF), whose water balance is strongly driven by fog persistence. This also depends on local and up wind temperature and moisture, and changes in this balance alter the impacts of changes in land use and climate on hydrology. These TMCFs were until 2010 only investigated up to 350km from the coast. Continental TMCFs are largely ignored. This gap is covered by our study area, which is part of the Orinoco river basin highlands and located on the northern Eastern Andes at an altitudinal range of 1550 to 2300m a.s.l. The upwind part of our study area is dominated by lowland savannahs that are flooded seasonally. Because meteorological stations are absent in our study area, we first describe the spatial and seasonal meteorological variability and analyse the corresponding catchment hydrology. Our hydro-meteorological data set is collected at three gauged neighbouring catchments with contrasting TMCF/grassland cover from June 2013 to May 2014 and includes hourly solar radiation, temperature, relative humidity, wind speed, precipitation, soil moisture and runoff measurements. We compare our results with recent TCMF studies in the eastern Andean highlands in the Amazon basin. The studied elevational range always shows wetter conditions at higher elevations. This indicates a positive relation between elevation and fog or rainfall persistence. Lower elevations are more seasonally variable. Soil moisture data indicate that TMCFs do not use persistently more water than grasslands. Runoff data from our three catchments reflect the interaction between ecosystems and elevation. The less-forested catchment at lower elevations has a more seasonally variable runoff and present the lowest base flows during the dry season. In this season, soil water storage and the wetter conditions at higher elevations are crucial to sustain their base flow. The hydro-meteorological patterns of our study area are similar to those at the eastern Andean TMCF sites, but differences in the elevation of fog and rainfall persistence suggest that specific upwind ecosystem conditions and distance to the coast are important to explain and understand regional seasonal differences.

76 FR 36533 - Bangor Hydro Electric Company; Notice of Request for Waiver

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-22

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. TS11-5-000] Bangor Hydro...(d) of the Commission's regulations, 18 CFR 358.1(d) (2011), Bangor Hydro Electric Company (Bangor Hydro) requests a limited waiver of Part 358 of the Commission's Regulations, Standards of Conduct for...

78 FR 938 - Burton Creek Hydro Inc., Sollos Energy, LLC'

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-07

... Hydro Inc., Sollos Energy, LLC' Notice of Transfer of Exemption 1. By letter filed December 19, 2012, Burton Creek Hydro Inc. informed the Commission that its exemption from licensing for the Burton Creek Hydro Project, FERC No. 7577, originally issued September 25, 1985,\\1\\ has been transferred to Sollos...

Effects Of Bedrock Shape And Hillslope Gradient On The Pore-Water Pressure Development: Implication For Slope Stability

NASA Astrophysics Data System (ADS)

Lanni, Cristiano; McDonnell, Jeff

2010-05-01

Shallow Landslides are one of the most important causes of loss of human life and socio-economic damage related to the hydro-geological risk issues. The danger of these phenomena is related to their speed of development, the diffculty of foreseeing their location, and the high density of individual phenomena, whose downhill trajectories have a relevant probability of interfering with urbanized areas. Research activity on precipitation-induced landslides has focused mainly on developing predictive understanding of where and when landslides are likely to occur. Nevertheless, some major aspects that may be related to activation of landslides have been poorly investigated. For instance, landslide susceptibility zones are generally predicted assuming constant thickness of soil over an impervious bedrock layer. Nevertheless, recent studies showed subsurface topography could be a first order control for subsurface water-flow dynamics, because of the effects of its own irregular shape. Tromp-van Meerveld and McDonnell (2006) argued that connectivity of patches of transient saturation were a necessary prerequisite for exceeding the rainfall threshold necessary to drive lateral flow. Connectivity - "how the hillslope architecture controls the filling and spilling of isolated patches of saturation" (Hopp and McDonnell, 2009) - appears to be a possible unifying concept and theoretical platform for moving hillslope and watershed hydrology forward. Connectivity could also have important implications on triggering of shallow landslides, because the particular shape of bedrock may limit the water-flow downhill. Here we present a number of virtual numerical experiments performed to investigate the role of bedrock shape and hillslope gradient on pore-water pressure development. On this purpose, our test is represented by the subsurface topography of the Panola Experiment Hillslope (PEH). That is because scientific literature on PEH provides substantial documentation about the role of bedrock layer on subsurface water-flow dynamics. We also exploit the concept of Downslope Index (DWI) (Hjerdt et al., 2004) and Upslope Contributing Area (UCA) as indicators of the areas more susceptible to landslide. The results indicate that bedrock shape influences the max pore-water pressure, even with different hillslope gradients; meanwhile, hillslope gradient affects the persistence-time of the max pore-water pressure. Moreover, results suggest DWI as an useful index to improve the capability of the very-used SHALSTAB model to assess for landslide susceptibility areas.

Sensitivity of alpine watersheds to global change

NASA Astrophysics Data System (ADS)

Zierl, B.; Bugmann, H.

2003-04-01

Mountains provide society with a wide range of goods and services, so-called mountain ecosystem services. Besides many others, these services include the most precious element for life on earth: fresh water. Global change imposes significant environmental pressure on mountain watersheds. Climate change is predicted to modify water availability as well as shift its seasonality. In fact, the continued capacity of mountain regions to provide fresh water to society is threatened by the impact of environmental and social changes. We use RHESSys (Regional HydroEcological Simulation System) to analyse the impact of climate as well as land use change (e.g. afforestation or deforestation) on hydrological processes in mountain catchments using sophisticated climate and land use scenarios. RHESSys combines distributed flow modelling based on TOPMODEL with an ecophysiological canopy model based on BIOME-BGC and a climate interpolation scheme based on MTCLIM. It is a spatially distributed daily time step model designed to solve the coupled cycles of water, carbon, and nitrogen in mountain catchments. The model is applied to various mountain catchments in the alpine area. Dynamic hydrological and ecological properties such as river discharge, seasonality of discharge, peak flows, snow cover processes, soil moisture, and the feedback of a changing biosphere on hydrology are simulated under current as well as under changed environmental conditions. Results of these studies will be presented and discussed. This project is part of an over overarching EU-project called ATEAM (acronym for Advanced Terrestrial Ecosystem Analysis and Modelling) assessing the vulnerability of European ecosystem services.

Hyphenated hydrology: Interdisciplinary evolution of water resource science

NASA Astrophysics Data System (ADS)

McCurley, Kathryn L.; Jawitz, James W.

2017-04-01

Hydrology has advanced considerably as a scientific discipline since its recognized inception in the mid-twentieth century. Modern water resource related questions have forced adaptation from exclusively physical or engineering science viewpoints toward a deliberate interdisciplinary context. Over the past few decades, many of the eventual manifestations of this evolution were foreseen by prominent expert hydrologists. However, their narrative descriptions have lacked substantial quantification. This study addressed that gap by measuring the prevalence of and analyzing the relationships between the terms most frequently used by hydrologists to define and describe their research. We analyzed 16,591 journal article titles from 1965-2015 in Water Resources Research, through which the scientific dialogue and its time-sensitive progression emerged. Our word frequency and term cooccurrence network results revealed the dynamic timing of the lateral movement of hydrology across multiple disciplines as well as the deepening of scientific discourse with respect to traditional hydrologic questions. The conversation among water resource scientists surrounding the hydrologic subdisciplines of catchment-hydrology, hydro-meteorology, socio-hydrology, hydro-climatology, and eco-hydrology gained statistically significant momentum in the analyzed time period, while that of hydro-geology and contaminant-hydrology experienced periods of increase followed by significant decline. This study concludes that formerly exotic disciplines can potentially modify hydrology, prompting new insights and inspiring unconventional perspectives on old questions that may have otherwise become obsolete.

How important is hydrotherapy? Effects of dynamic action of hot spring water as a rehabilitative treatment for burn patients in Switzerland.

PubMed

Moufarrij, S; Deghayli, L; Raffoul, W; Hirt-Burri, N; Michetti, M; de Buys Roessingh, A; Norberg, M; Applegate, L A

2014-12-31

Burn rehabilitation using hydrotherapy can have multiple benefits for the burn patient. The therapy uses specific mineral enriched hot spring water and water jets with varied hydro-pressure to combat hypertrophy, inflammatory reaction signs, abnormal pigmentation, and, more specifically, redness and scarring. Standard operating procedures for burn rehabilitation have been developed and integrated into the Standard of Care at the CHUV hospital using localized hydro-mechanical stimulation of burn sites (20 minutes of alternating anatomical sites) followed by constant pressure large-bore and filiform showers targeting specific scarred areas. These therapeutic regimens are repeated daily for 2 to 3 weeks. Patients showed lasting effects from this regimen (up to 3-6 months), the results becoming permanent with more uniform skin structure, color and visco-elasticity in addition to a decrease in pruritus. The specifications of clinical protocols are described herein along with the virtues of hot spring hydro-pressure therapy for burn rehabilitation. The use of hydrotherapy, which has been a controversial topic among burn units across the world, is also discussed. In North America, hydrotherapy is defined only within the scope of in-patient wound cleansing and is thought to lead to microbial auto-contamination and bacterial resistance. In Switzerland and France the emphasis of hydrotherapy is on rehabilitation after the wound has closed.

How important is hydrotherapy? Effects of dynamic action of hot spring water as a rehabilitative treatment for burn patients in Switzerland

PubMed Central

Moufarrij, S.; Deghayli, L.; Raffoul, W.; Hirt-Burri, N.; Michetti, M.; de Buys Roessingh, A.; Norberg, M.; Applegate, L.A.

2014-01-01

Summary Burn rehabilitation using hydrotherapy can have multiple benefits for the burn patient. The therapy uses specific mineral enriched hot spring water and water jets with varied hydro-pressure to combat hypertrophy, inflammatory reaction signs, abnormal pigmentation, and, more specifically, redness and scarring. Standard operating procedures for burn rehabilitation have been developed and integrated into the Standard of Care at the CHUV hospital using localized hydro-mechanical stimulation of burn sites (20 minutes of alternating anatomical sites) followed by constant pressure large-bore and filiform showers targeting specific scarred areas. These therapeutic regimens are repeated daily for 2 to 3 weeks. Patients showed lasting effects from this regimen (up to 3-6 months), the results becoming permanent with more uniform skin structure, color and visco-elasticity in addition to a decrease in pruritus. The specifications of clinical protocols are described herein along with the virtues of hot spring hydro-pressure therapy for burn rehabilitation. The use of hydrotherapy, which has been a controversial topic among burn units across the world, is also discussed. In North America, hydrotherapy is defined only within the scope of in-patient wound cleansing and is thought to lead to microbial auto-contamination and bacterial resistance. In Switzerland and France the emphasis of hydrotherapy is on rehabilitation after the wound has closed. PMID:26336365

Identifying Effective Policy and Technologic Reforms for Sustainable Groundwater Management in Oman

NASA Astrophysics Data System (ADS)

Madani, K.; Zekri, S.; Karimi, A.

2014-12-01

Oman has gone through three decades of efforts aimed at addressing groundwater over-pumping and the consequent seawater intrusion. Example of measures adopted by the government since the 1990's include a vast subsidy program of irrigation modernization, a freeze on drilling new wells, delimitation of several no-drill zones, a crop substitution program, re-use of treated wastewater and construction of recharge dams. With no major success through these measures, the government laid the ground for water quotas by creating a new regulation in 1995. Nevertheless, groundwater quotas have not been enforced to date due to the high implementation and monitoring costs of traditional flow meters. This presentation discusses how sustainable groundwater management can be secured in Oman using a suit of policy and technologic reforms at a reasonable economic, political and practical cost. Data collected from farms with smart meters and low-cost wireless smart irrigation systems have been used to propose sustainable groundwater withdrawal strategies for Oman using a detailed hydro-economic model that couples a MODFLOW-SEAWAT model of the coastal aquifers with a dynamic profit maximization model. The hydro-economic optimization model was flexible to be run both as a social planner model to maximize the social welfare in the region, and as an agent-based model to capture the behavior of farmers interested in maximizing their profits independently. This flexibility helped capturing the trade-off between the optimality of the social planner solution developed at the system's level and its practicality (stability) with respect to the concerns and behaviors of the profit-maximizing farmers. The idetified promising policy and technolgical reforms for Oman include strict enforcement of groundwater quotas, smart metering, changing crop mixes, improving irrigation technologies, and revising geographical distribution of the farming activities. The presentation will discuss how different combinations of these reforms would affect groundwater and energy use, groundwater level and salinity, crop yield, and agricultural revenues in the future.

Hydro-economic Risk Assessment in the Eastern Nile River Basin

NASA Astrophysics Data System (ADS)

Arjoon, D.; Tilmant, A.; Mohamed, Y.

2013-12-01

In 2011, the Ethiopian government announced plans for the construction of the Grand Renaissance Dam (GRD) on the Blue Nile, just east of its border with Sudan, at a cost of almost 5 billion dollars. The project is expected to generate over 15 TWh of energy and will include a reservoir of more than 60 km3 capacity, which roughly corresponds to the average annual flow of the Blue Nile. This project is part of a larger scheme, by the government, to expand its hydroelectric power capacity, however, the scheme faces strong opposition from downstream Egypt and Sudan. Egypt and Sudan are highly dependent on flows that originate in Ethiopia (it has been estimated that 86% of Nile flow originates in the Ethiopian highlands). The Ethiopian government argues that the dam would supply electricity for Ethiopians as well as generate surplus energy for export to neighboring countries. The Ethiopians also argue that the huge reservoir would generate positive externalities downstream by reducing floods and providing more constant and predictable lows. This study attempts to provide an independent analysis of the hydrologic and economic risks faced by downstream countries when GRD will be online. To achieve this, an integrated, stochastic hydro-economic model of the entire Eastern Nile basin is used to analyze various development and management scenarios. The results indicate that if countries agree to co- operative management of the Eastern Nile River basin, GRD would indeed significantly increase basin-wide benefits, especially in Ethiopia and in Sudan. An alternative management scenario, whereby GRD would be operated by Sudan and Egypt, does not yield significant economic gains in these countries. However, massive unilateral irrigation developments in Ethiopia will be detrimental for all countries, including Ethiopia itself, due to the huge opportunity costs involved.

A semi-urban case study of small scale variability of rainfall and run-off, with C- and X-band radars and the fully distributed hydrological model Multi-Hydro

NASA Astrophysics Data System (ADS)

Alves de Souza, Bianca; da Silva Rocha Paz, Igor; Gires, Auguste; Tchiguirinskaia, Ioulia; Schertzer, Daniel

2016-04-01

The complexity of urban hydrology results both from that of urban systems and the extreme rainfall variability. The latter can display strongly localised rain cells that can be extremely damaging when hitting vulnerable parts of urban systems. This paper investigates this complexity on a semi-urban sub-catchment - located in Massy (South of Paris, France) - of the Bievre river, which is known for its frequent flashfloods. Advanced geo-processing techniques were used to find the ideal pixel size for this 6.326km2 basin. C-band and X-band radar data are multifractally downscaled at various resolutions and input to the fully distributed hydrological model Multi-Hydro. The latter has been developed at Ecole des Ponts ParisTech. It integrates validated modules dealing with surface flow, saturated and unsaturated surface flow, and sewer flow. The C-band radar is located in Trappes, approx. 21km East of the catchment, is operated by Méteo-France and has a resolution of 1km x 1km x 5min. The X-band radar operated by Ecole des Ponts Paris Tech on its campus has a resolution of 125m x 125m x 3.4min. The performed multifractal downscaling enables both the generation of large ensemble realizations and easy change of resolution (e.g. down to 10 m in the present study). This in turn allows a detailed analysis of the impacts of small scale variability and the required resolution to obtain accurate simulations, therefore predictions. This will be shown on two rainy episodes over the chosen sub-catchment of the Bievre river.

Effects of a flood pulse on exchange flows along a sinuous stream

NASA Astrophysics Data System (ADS)

Käser, D.; Brunner, P.; Renard, P.; Perrochet, P.; Schirmer, M.; Hunkeler, D.

2012-04-01

Flood pulses are important events for river ecosystems: they create hydrological interactions at the terrestrial/aquatic interface that fuel biological productivity and shape the hyporheic-riparian habitats. For example, floods promote faunal activity and decomposition by increasing the supply of oxygenated water in downwelling areas, while the following recession periods tend to provide stable thermal conditions favoured by fish or insects in areas of groundwater upwelling. This 3-D modelling study investigates the effect of stream stage transience (with events characterised by their intensity and duration) on hydrological exchanges between the surface and the near-stream subsurface. It evaluates, in particular, its effect on streams of varying sinuosity by quantifying the dynamic response of: (1) subsurface flow paths, (2) the exchange pattern at the sediment-water interface, and (3) integrative measures such as total exchange flux and total storage. Understanding geomorphological controls on groundwater/surface water interactions is attractive because topography is generally better constrained than subsurface parameters, and can be used in data-poor situations. The numerical model represents a hypothetical alluvial plain limited by impervious bedrock on all four sides, and in which the channel meanders according to the sine-generated curve of Langbein and Leopold (1966). As the model (HydroGeoSphere) couples surface and subsurface flow, the stream stage transience is imposed by a fluctuating head at the channel inlet. Preliminary results show that a simple rectangular flood pulse in an idealised sinuous stream without additional complexity can generate multiple flow direction reversals at a single point in the channel. The initial conditions of the groundwater table, the channel sinuosity and the time characteristics of the flood pulse all control exchange flow features in different ways. Results are also compared with 'bank storage' analytical solutions that typically assume a straight channel. The discussion covers an evaluation of this work with respect to previous studies that considered the influence of sinuosity on interfacial exchange flows. It addresses the issue of steady vs. transient exchanges, which is of uppermost importance at the operational scale of river restoration schemes. Langbein WB, Leopold LB. 1966. River meanders - theory of minimum variance. U.S. Geol. Surv. Prof. Pap. 422-H: 15 p.

Application of a 3D Model to Assess the Thermo-Hydrological Effects of Climate Warming in a Discontinuous Permafrost Zone, Umiujaq, Northern Quebec, Canada

NASA Astrophysics Data System (ADS)

Parhizkar, M.; Therrien, R.; Molson, J. W. H.; Lemieux, J. M.; Fortier, R.; Talbot Poulin, M. C.; Therrien, P.; Ouellet, M.

2016-12-01

The rate of permafrost degradation in northern Quebec, Canada, has increased over the last two decades due to climate warming, which is expected to significantly modify the hydrogeologic and thermal regimes. Groundwater accessibility is also expected to increase and could become a significant source of drinking water for northern communities. In this project, an integrated surface water / groundwater flow model, HydroGeoSphere, is being applied to a 2 km2catchment in northern Quebec to assess the effect of future climate change on thermo-hydrological conditions as well as on changes in groundwater availability for northern communities. The catchment is located in a discontinuous but widespread permafrost zone near Umiujaq (northern Quebec, Canada) where the subsurface consists of a 10-30 m-thick coarse-grained glaciofluvial layer forming a good aquifer beneath a permafrost-rich silty marine unit. A conceptual thermo-hydrological model of the catchment has been built from field data collected over 5 years, including hydraulic heads, stream flow rates, subsurface geology, as well as ground temperatures and thermal fluxes around two 10-20 m-thick permafrost mounds. The integrated 3D numerical model includes variably-saturated groundwater flow with transient recharge, as well as advective-conductive heat transport driven by transient air temperatures (varying from about -40 to +30 ºC) and a geothermal heat flux of 60 mW/m2. The model is calibrated to observed heads and temperatures by coupling PEST with HydroGeoSphere, allowing changes in hydraulic and thermal conductivities. Preliminary results are consistent with the available observed data, however non-uniqueness remains an important issue. The simulations are providing useful predictions of the permafrost thaw rate and associated changes to the hydrogeological flow system, including increased aquifer recharge following permafrost thaw.

THM large spatial-temporal model to simulate the past 2 Ma hydrogeological evolution of Paris Basin including natural tracer transport as part of site characterization for radwaste repository project Cigéo - France

NASA Astrophysics Data System (ADS)

Benabderrahmane, A., Sr.

2017-12-01

Hydrogeological site characterization for deep geological high level and intermediate level long lived radioactive waste repository cover a large time scale needed for safety analysis and calculation. Hydrogeological performance of a site relies also on the effects of geodynamic evolution as tectonic uplift, erosion/sedimentation and climate including glaciation on the groundwater flow and solute and heat transfer. Thermo-Hydro-Mechanical model of multilayered aquifer system of Paris Basin is developed to reproduce the present time flow and the natural tracer (Helium) concentration profiles based on the last 2 Ma of geodynamic evolution. Present time geological conceptual model consist of 27 layers at Paris Basin (Triassic-Tertiary) with refinement at project site scale (29 layers from Triassic to Portlandian). Target layers are the clay host formation of Callovo-Oxfrodian age (160 Ma) and the surrounding aquifer layers of Oxfordian and Dogger. Modelled processes are: groundwater flow, heat and solutes (natural tracers) transport, freezing and thawing of groundwater (expansion and retreat of permafrost), deformation of the multilayered aquifer system induced by differential tectonic uplift and the hydro-mechanical stress effect as caused by erosion of the outcropping layers. Numerical simulation considers a period from 2 Ma BP and up to the present. Transient boundary conditions are governed by geodynamic processes: (i) modification of the geometry of the basin and (ii) temperatures along the topography will change according to a series of 15 identical climate cycles with multiple permafrost (glaciation) periods. Numerical model contains 71 layers and 18 million cells. The solution procedure solves three coupled systems of equations, head, temperature and concentrations, by the use of a finite difference method, and by applying extensive parallel processing. The major modelling results related to the processes of importance for site characterization as hydraulic head distribution, flow velocity, heat and natural tracer transport impacted by geodynamic past evolution are discussed.

What if we took a global look?

NASA Astrophysics Data System (ADS)

Ouellet Dallaire, C.; Lehner, B.

2014-12-01

Freshwater resources are facing unprecedented pressures. In hope to cope with this, Environmental Hydrology, Freshwater Biology, and Fluvial Geomorphology have defined conceptual approaches such as "environmental flow requirements", "instream flow requirements" or "normative flow regime" to define appropriate flow regime to maintain a given ecological status. These advances in the fields of freshwater resources management are asking scientists to create bridges across disciplines. Holistic and multi-scales approaches are becoming more and more common in water sciences research. The intrinsic nature of river systems demands these approaches to account for the upstream-downstream link of watersheds. Before recent technological developments, large scale analyses were cumbersome and, often, the necessary data was unavailable. However, new technologies, both for information collection and computing capacity, enable a high resolution look at the global scale. For rivers around the world, this new outlook is facilitated by the hydrologically relevant geo-spatial database HydroSHEDS. This database now offers more than 24 millions of kilometers of rivers, some never mapped before, at the click of a fingertip. Large and, even, global scale assessments can now be used to compare rivers around the world. A river classification framework was developed using HydroSHEDS called GloRiC (Global River Classification). This framework advocates for holistic approach to river systems by using sub-classifications drawn from six disciplines related to river sciences: Hydrology, Physiography and climate, Geomorphology, Chemistry, Biology and Human impact. Each of these disciplines brings complementary information on the rivers that is relevant at different scales. A first version of a global river reach classification was produced at the 500m resolution. Variables used in the classification have influence on processes involved at different scales (ex. topography index vs. pH). However, all variables are computed at the same high spatial resolution. This way, we can have a global look at local phenomenon.

77 FR 55212 - North Star Hydro Services CA, LLC; Notice of Preliminary Permit Application Accepted for Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-07

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 14379-000] North Star Hydro..., Motions To Intervene, and Competing Applications On March 30, 2012, North Star Hydro Services CA, LLC... approximately 3.8 gigawatthours. Applicant Contact: David Holland, North Star Hydro Services CA, LLC, 1110 West...

77 FR 55212 - North Star Hydro Services CA, LLC; Notice of Preliminary Permit Application Accepted for Filing...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-07

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 14399-000] North Star Hydro..., Motions to Intervene, and Competing Applications On March 30, 2012, North Star Hydro Services CA, LLC... output would be approximately 4.6 gigawatthours. Applicant Contact: David Holland, North Star Hydro...

78 FR 48670 - Rivermill Hydroelectric, Inc., New Hampshire Hydro Associates; Notice of Transfer of Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-09

... Hydroelectric, Inc., New Hampshire Hydro Associates; Notice of Transfer of Exemption August 5, 2013. 1. By letter filed July 19, 2013, Rivermill Hydroelectric, Inc. and New Hampshire Hydro Associates informed the... issued September 21, 1988,\\2\\ has been transferred to New Hampshire Hydro Associates. The project is...

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Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-18

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13843-001] Qualified Hydro... No.: 13843-001. c. Date filed: January 3, 2012. d. Applicant: Qualified Hydro 24, LLC. [[Page 29631...: Ramya Swaminathan, Qualified Hydro 24, LLC, 239 Causeway Street, Suite 300, Boston, MA 02114; (978) 283...

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2012-02-23

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 14261-000, 14268-000, 14277-000, 14281-000] Lock+ Hydro Friends Fund XVIII, Upper Hydroelectric, LLC, FFP Project 95, LLC...-Tombigbee Waterway in Lowndes County, Mississippi. The applications were filed by Lock+ Hydro Friends Fund...

Nonlinear Dynamics of Complex Coevolutionary Systems in Historical Times

NASA Astrophysics Data System (ADS)

Perdigão, Rui A. P.

2016-04-01

A new theoretical paradigm for statistical-dynamical modeling of complex coevolutionary systems is introduced, with the aim to provide historical geoscientists with a practical tool to analyse historical data and its underlying phenomenology. Historical data is assumed to represent the history of dynamical processes of physical and socio-economic nature. If processes and their governing laws are well understood, they are often treated with traditional dynamical equations: deterministic approach. If the governing laws are unknown or impracticable, the process is often treated as if being random (even if it is not): statistical approach. Although single eventful details - such as the exact spatiotemporal structure of a particular hydro-meteorological incident - may often be elusive to a detailed analysis, the overall dynamics exhibit group properties summarized by a simple set of categories or dynamical regimes at multiple scales - from local short-lived convection patterns to large-scale hydro-climatic regimes. The overwhelming microscale complexity is thus conveniently wrapped into a manageable group entity, such as a statistical distribution. In a stationary setting whereby the distribution is assumed to be invariant, alternating regimes are approachable as dynamical intermittence. For instance, in the context of bimodal climatic oscillations such as NAO and ENSO, each mode corresponds to a dynamical regime or phase. However, given external forcings or longer-term internal variability and multiscale coevolution, the structural properties of the system may change. These changes in the dynamical structure bring about a new distribution and associated regimes. The modes of yesteryear may no longer exist as such in the new structural order of the system. In this context, aside from regime intermittence, the system exhibits structural regime change. New oscillations may emerge whilst others fade into the annals of history, e.g. particular climate fluctuations during the Little Ice Age. Traditional theories of stochastic processes and dynamical systems are grounded on the existence of so-called dynamical invariants; properties that remain unchanged as the dynamics unfold, assuming structural invariance and ergodicity of the underlying system. However, such theories are no longer optimal when trying to understand and model long-term historical records of coevolutionary systems. A new paradigm is thus needed. Therefore, we introduce a new class of dynamical systems that reinvent themselves as the dynamics unfold. Rather than only changing variables and parameters under a rigid framework, the governing laws are malleable themselves. The novel formulation captures and explains the coevolutionary dynamics of multiscale hydroclimatic systems, bringing along a physically sound understanding of their regimes, transitions and extremes over a long-term history.

Spatial and temporal variations of thaw layer thickness and its controlling factors identified using time-lapse electrical resistivity tomography and hydro-thermal modeling

NASA Astrophysics Data System (ADS)

Tran, Anh Phuong; Dafflon, Baptiste; Bisht, Gautam; Hubbard, Susan S.

2018-06-01

Quantitative understanding of controls on thaw layer thickness (TLT) dynamics in the Arctic peninsula is essential for predictive understanding of permafrost degradation feedbacks to global warming and hydrobiochemical processes. This study jointly interprets electrical resistivity tomography (ERT) measurements and hydro-thermal numerical simulation results to assess spatiotemporal variations of TLT and to determine its controlling factors in Barrow, Alaska. Time-lapse ERT measurements along a 35-m transect were autonomously collected from 2013 to 2015 and inverted to obtain soil electrical resistivity. Based on several probe-based TLT measurements and co-located soil electrical resistivity, we estimated the electrical resistivity thresholds associated with the boundary between the thaw layer and permafrost using a grid search optimization algorithm. Then, we used the obtained thresholds to derive the TLT from all soil electrical resistivity images. The spatiotemporal analysis of the ERT-derived TLT shows that the TLT at high-centered polygons (HCPs) is smaller than that at low-centered polygons (LCPs), and that both thawing and freezing occur earlier at the HCPs compared to the LCPs. In order to provide a physical explanation for dynamics in the thaw layer, we performed 1-D hydro-thermal simulations using the community land model (CLM). Simulation results showed that air temperature and precipitation jointly govern the temporal variations of TLT, while the topsoil organic content (SOC) and polygon morphology are responsible for its spatial variations. When the topsoil SOC and its thickness increase, TLT decreases. Meanwhile, at LCPs, a thicker snow layer and saturated soil contribute to a thicker TLT and extend the time needed for TLT to freeze and thaw. This research highlights the importance of combination of measurements and numerical modeling to improve our understanding spatiotemporal variations and key controls of TLT in cold regions.

Hydrologic Modeling at the National Water Center: Operational Implementation of the WRF-Hydro Model to support National Weather Service Hydrology

NASA Astrophysics Data System (ADS)

Cosgrove, B.; Gochis, D.; Clark, E. P.; Cui, Z.; Dugger, A. L.; Fall, G. M.; Feng, X.; Fresch, M. A.; Gourley, J. J.; Khan, S.; Kitzmiller, D.; Lee, H. S.; Liu, Y.; McCreight, J. L.; Newman, A. J.; Oubeidillah, A.; Pan, L.; Pham, C.; Salas, F.; Sampson, K. M.; Smith, M.; Sood, G.; Wood, A.; Yates, D. N.; Yu, W.; Zhang, Y.

2015-12-01

The National Weather Service (NWS) National Water Center(NWC) is collaborating with the NWS National Centers for Environmental Prediction (NCEP) and the National Center for Atmospheric Research (NCAR) to implement a first-of-its-kind operational instance of the Weather Research and Forecasting (WRF)-Hydro model over the Continental United States (CONUS) and contributing drainage areas on the NWS Weather and Climate Operational Supercomputing System (WCOSS) supercomputer. The system will provide seamless, high-resolution, continuously cycling forecasts of streamflow and other hydrologic outputs of value from both deterministic- and ensemble-type runs. WRF-Hydro will form the core of the NWC national water modeling strategy, supporting NWS hydrologic forecast operations along with emergency response and water management efforts of partner agencies. Input and output from the system will be comprehensively verified via the NWC Water Resource Evaluation Service. Hydrologic events occur on a wide range of temporal scales, from fast acting flash floods, to long-term flow events impacting water supply. In order to capture this range of events, the initial operational WRF-Hydro configuration will feature 1) hourly analysis runs, 2) short-and medium-range deterministic forecasts out to two day and ten day horizons and 3) long-range ensemble forecasts out to 30 days. All three of these configurations are underpinned by a 1km execution of the NoahMP land surface model, with channel routing taking place on 2.67 million NHDPlusV2 catchments covering the CONUS and contributing areas. Additionally, the short- and medium-range forecasts runs will feature surface and sub-surface routing on a 250m grid, while the hourly analyses will feature this same 250m routing in addition to nudging-based assimilation of US Geological Survey (USGS) streamflow observations. A limited number of major reservoirs will be configured within the model to begin to represent the first-order impacts of streamflow regulation.

Resistivity method contribution in determining of fault zone and hydro-geophysical characteristics of carbonate aquifer, eastern desert, Egypt

NASA Astrophysics Data System (ADS)

Ammar, A. I.; Kamal, K. A.

2018-03-01

Determination of fault zone and hydro-geophysical characteristics of the fractured aquifers are complicated, because their fractures are controlled by different factors. Therefore, 60 VESs were carried out as well as 17 productive wells for determining the locations of the fault zones and the characteristics of the carbonate aquifer at the eastern desert, Egypt. The general curve type of the recorded rock units was QKH. These curves were used in delineating the zones of faults according to the application of the new assumptions. The main aquifer was included at end of the K-curve type and front of the H-curve type. The subsurface layers classified into seven different geoelectric layers. The fractured shaly limestone and fractured limestone layers were the main aquifer and their resistivity changed from low to medium (11-93 Ω m). The hydro-geophysical properties of this aquifer such as the areas of very high, high, and intermediate fracture densities of high groundwater accumulations, salinity, shale content, porosity distribution, and recharging and flowing of groundwater were determined. The statistical analysis appeared that depending of aquifer resistivity on the water salinities (T.D.S.) and water resistivities add to the fracture density and shale content. The T.D.S. increasing were controlled by Na+, Cl-, Ca2+, Mg2+, and then (SO4)2-, respectively. The porosity was calculated and its average value was 19%. The hydrochemical analysis of groundwater appeared that its type was brackish and the arrangements of cation concentrations were Na+ > Ca2+ > Mg2+ > K+ and anion concentrations were Cl- > (SO4)2- > HCO3 - > CO3 -. The groundwater was characterized by sodium-bicarbonate and sodium-sulfate genetic water types and meteoric in origin. Hence, it can use the DC-resistivity method in delineating the fault zone and determining the hydro-geophysical characteristics of the fractured aquifer with taking into account the quality of measurements and interpretation.

Demonstration of variable speed permanent magnet generator at small, low-head hydro site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown Kinloch, David

Small hydro developers face a limited set of bad choices when choosing a generator for a small low-head hydro site. Direct drive synchronous generators are expensive and technically complex to install. Simpler induction generators are higher speed, requiring a speed increaser, which results in inefficiencies and maintenance problems. In addition, both induction and synchronous generators turn at a fixed speed, causing the turbine to run off its peak efficiency curve whenever the available head is different than the designed optimum head.The solution to these problems is the variable speed Permanent Magnet Generators (PMG). At the Weisenberger Mill in Midway, KY,more » a variable speed Permanent Magnet Generator has been installed and demonstrated. This new PMG system replaced an existing induction generator that had a HTD belt drive speed increaser system. Data was taken from the old generator before it was removed and compared to data collected after the PMG system was installed. The new variable speed PMG system is calculated to produce over 96% more energy than the old induction generator system during an average year. This significant increase was primarily due to the PMG generator operating at the correct speed at the maximum head, and the ability for the PMG generator to reduce its speed to lower optimum speeds as the stream flow increased and the net head decreased.This demonstration showed the importance of being able to adjust the speed of fixed blade turbines. All fixed blade turbines with varying net heads could achieve higher efficiencies if the speed can be matched to the optimum speed as the head changes. In addition, this demonstration showed that there are many potential efficiencies that could be realized with variable speed technology at hydro sites where mismatched turbine and generator speeds result in lower power output, even at maximum head. Funding for this project came from the US Dept. of Energy, through Award Number DE-EE0005429.« less

HydroViz: A web-based hydrologic observatory for enhancing hydrology and earth-science education

NASA Astrophysics Data System (ADS)

Habib, E. H.; Ma, Y.; Williams, D.

2010-12-01

The main goal of this study is to develop a virtual hydrologic observatory (HydroViz) that integrates hydrologic field observations with numerical simulations by taking advantage of advances in hydrologic field & remote sensing data, computer modeling, scientific visualization, and web resources and internet accessibility. The HydroViz system is a web-based teaching tool that can run on any web browsers. It leverages the strength of Google Earth to provide authentic and hands-on activities to improve learning. Evaluation of the HydroViz was performed in three engineering courses (a senior level course and two Introductory courses at two different universities). Evaluation results indicate that HydroViz provides an improvement over existing engineering hydrology curriculum. HydroViz was effective in facilitating students’ learning and understanding of hydrologic concepts & increasing related skills. HydroViz was much more effective for students in engineering hydrology classes rather than at the freshmen introduction to civil engineering class. We found that HydroViz has great potential for freshmen audience. Even though HydroViz was challenging to some freshmen, most of them still learned the key concepts and the tool increased the enthusiasm for half of the freshmen. The evaluation provided suggestions to create a simplified version of HydroViz for freshmen-level courses students. It identified concepts and tasks that might be too challenging or irrelevant to the freshmen and areas where we could provide more guidance in the tool. After the first round of evaluation, the development team has made significant improvements to HydroViz, which would further improve its effectiveness for next round of class applications which is planned for the Fall of 2010 to take place in 5 classes at 4 different institutions.

Pharmacokinetics and behavioral effects of liposomal hydromorphone suitable for perioperative use in rhesus macaques

PubMed Central

KuKanich, Butch; Schmidt, Brynn; Heath, Timothy D.; Brown, Carolyn

2011-01-01

Introduction This study aims to evaluate the pharmacokinetic, behavioral, and motor effects of a liposomal preparation of hydromorphone hydrochloride (LE-hydro) in rhesus monkeys. We administered either 2 mg/kg of LE-hydro (n=8) subcutaneous (s.c.) or 0.1 mg/kg of standard pharmaceutical hydromorphone HCl (hydro) preparation either intravenous (i.v.; n=4) or s.c. (n=5). Materials and methods Serial blood samples were drawn after injection and analyzed for serum hydro concentration by liquid chromatography/mass spectrometry. Following s.c. injection of 0.1 mg/kg hydro or 2 mg/kg LE-hydro, behavioral evaluations were conducted in groups of rhesus monkeys (n=10/group) in the presence of a compatible stimulus animal and motor skills were also evaluated (n=10/group). The motor skills test consisted of removing a food reward (carrot ring) from either a straight peg (simple task) or a curved peg (difficult task). Results LE-hydro (MRT0-INF = 105.9 h) demonstrated extended-release pharmacokinetics compared to hydro when administered by either i.v. (MRT0-INF =1.1 h) or s.c. (MRT0-INF =1.3 h) routes. Hydro did not affect motor performance of the simpler task, but the monkeys’ performance deteriorated on the more difficult task at 0.5 and 1 h after injection. LE-hydro had no effect on motor skills in either the simpler or more difficult task. Conclusions The results of these studies indicate that LE-hydro has a pharmacokinetic and behavioral side effects profile consistent with an analgesic that could be tested for surgical use in animals. Our studies also expand the use of rhesus monkeys as a translational behavioral pharmacodynamics model for testing extended-release opioid medication. PMID:21404039

HydroViz: evaluation of a web-based tool for improving hydrology education

NASA Astrophysics Data System (ADS)

Habib, E.; Ma, Y.; Williams, D.; Sharif, H.; Hossain, F.

2012-02-01

HydroViz is a web-based, student-centered, highly visual educational tool designed to support active learning in the field of Engineering Hydrology. The development of HydroViz is informed by recent advances in hydrologic data, numerical simulations, visualization and web-based technologies. An evaluation study was conducted to determine the effectiveness of HydroViz, to examine the buy-in of the program, and to identify project components that need to be improved. A total of 182 students from seven freshmen and junior-/senior-level undergraduate classes in three universities participated in the study over the course of two semesters (spring 2010 and fall 2010). Data sources included homework assignments, online surveys, and informal interviews with students. Descriptive statistics were calculated for homework and the survey. Qualitative analysis of students' comments and informal interview notes were also conducted to identify ideas and patterns. HydroViz was effective in facilitating students' learning and understanding of hydrologic concepts and increasing related skills. Students had positive perceptions of various features of HydroViz and they believe that HydroViz fits well in the curriculum. The experience with HydroViz was somewhat effective in raising freshmen civil engineering students' interest in hydrology. In general, HydroViz tend to be more effective with students in junior- or senior-level classes than students in freshmen classes. There does not seem to be obvious differences between different universities. Students identified some issues that can be addressed to improve HydroViz. Future adaptation and expansion studies are under planning to scale-up the application and utility of HydroViz into various hydrology and water-resource engineering curriculum settings.

Misrepresentation of hydro-erosional processes in rainfall simulations using disturbed soil samples

NASA Astrophysics Data System (ADS)

Thomaz, Edivaldo L.; Pereira, Adalberto A.

2017-06-01

Interrill erosion is a primary soil erosion process which consists of soil detachment by raindrop impact and particle transport by shallow flow. Interill erosion affects other soil erosion sub-processes, e.g., water infiltration, sealing, crusting, and rill initiation. Interrill erosion has been widely studied in laboratories, and the use of a sieved soil, i.e., disturbed soil, has become a standard method in laboratory experiments. The aims of our study are to evaluate the hydro-erosional response of undisturbed and disturbed soils in a laboratory experiment, and to quantify the extent to which hydraulic variables change during a rainstorm. We used a splash pan of 0.3 m width, 0.45 m length, and 0.1 m depth. A rainfall simulation of 58 mm h- 1 lasting for 30 min was conducted on seven replicates of undisturbed and disturbed soils. During the experiment, several hydro-physical parameters were measured, including splashed sediment, mean particle size, runoff, water infiltration, and soil moisture. We conclude that use of disturbed soil samples results in overestimation of interrill processes. Of the nine assessed parameters, four displayed greater responses in the undisturbed soil: infiltration, topsoil shear strength, mean particle size of eroded particles, and soil moisture. In the disturbed soil, five assessed parameters displayed greater responses: wash sediment, final runoff coefficient, runoff, splash, and sediment yield. Therefore, contextual soil properties are most suitable for understanding soil erosion, as well as for defining soil erodibility.

Impact of Hydrologic Variability on Ecosystem Dynamics and the Sustainable Use of Soil and Water Resources

NASA Astrophysics Data System (ADS)

Porporato, A. M.

2013-05-01

We discuss the key processes by which hydrologic variability affects the probabilistic structure of soil moisture dynamics in water-controlled ecosystems. These in turn impact biogeochemical cycling and ecosystem structure through plant productivity and biodiversity as well as nitrogen availability and soil conditions. Once the long-term probabilistic structure of these processes is quantified, the results become useful to understand the impact of climatic changes and human activities on ecosystem services, and can be used to find optimal strategies of water and soil resources management under unpredictable hydro-climatic fluctuations. Particular applications regard soil salinization, phytoremediation and optimal stochastic irrigation.

Merger of a Neutron Star with a Newtonian Black Hole

NASA Technical Reports Server (NTRS)

Lee, William H.; Kluzniak, Wlodzimierz

1995-01-01

Newtonian smooth particle hydro simulations are presented of the merger of a 1.4 solar mass neutron star with a black hole of equal mass. The initial state of the system is modeled with a stiff polytrope orbiting a point mass. Dynamical instability sets in when the orbital separation is equal to about three stellar radii. The ensuing mass transfer occurs on the dynamical timescale. No accretion torus is formed. At the end of the computation a corona of large extent shrouds an apparently stable binary system of a 0.25 solar mass star orbiting a 2.3 solar mass black hole.

Displacement of Tethered Hydro-Acoustic Modems by Uniform Horizontal Currents

DTIC Science & Technology

2009-12-01

smooth and plane surfaces (in incompressible flow ) in air and in water (From [4]) ..............22  Figure 13.  Drag of streamline bodies, tested in...from a stationary sea- surface buoy or Unmanned Surface Vehicle (USV) weighted by a dense object at the free end (Figure 2). The equations of static...forces on the free end are caused by an attached ballast or float. The moored cable has a free -moving sub- surface buoy positioned at a water depth

Hydro-sliding and the Springtime Dynamical Evolution of Kennicott Glacier, Alaska

NASA Astrophysics Data System (ADS)

Armstrong, W. H., Jr.; Anderson, R. S.

2017-12-01

Glacier basal motion is a poorly understood aspect of glacier mechanics that is responsible for the majority of ice flux on fast-flowing glaciers, enables rapid changes in glacier motion, and provides the means by which glaciers shape alpine landscapes. We collect hydrometerologic data and GPS-derived ice surface motion to probe the link between subglacial water pressure and the evolution of glacier velocity on Kennicott Glacier, Alaska. We find a chaotic timeseries of >50 m fill-and-drain sequences on the well-connected ice-marginal Donoho Falls Lake. Glacier velocity in the down-glacier reach responds sensitively to lake stage, with high amplitude diurnal velocity fluctuations during high or rising stage. The timing of velocity peaks precedes peak stage by 2-3 hours, and synchronously shifts earlier in the day throughout our observation period. We find the up-glacier station appears to first speed up in response to longitudinal coupling with accelerating down-glacier ice before responding to local variations in basal traction. We find the transition to responding to local basal conditions results in the glacier behaving more uniformly, with similar magnitude diurnal velocity fluctuations, synchronous timing of velocity extrema across the 10 km study reach, and steadier longitudinal strain rates.

Interface COMSOL-PHREEQC (iCP), an efficient numerical framework for the solution of coupled multiphysics and geochemistry

NASA Astrophysics Data System (ADS)

Nardi, Albert; Idiart, Andrés; Trinchero, Paolo; de Vries, Luis Manuel; Molinero, Jorge

2014-08-01

This paper presents the development, verification and application of an efficient interface, denoted as iCP, which couples two standalone simulation programs: the general purpose Finite Element framework COMSOL Multiphysics® and the geochemical simulator PHREEQC. The main goal of the interface is to maximize the synergies between the aforementioned codes, providing a numerical platform that can efficiently simulate a wide number of multiphysics problems coupled with geochemistry. iCP is written in Java and uses the IPhreeqc C++ dynamic library and the COMSOL Java-API. Given the large computational requirements of the aforementioned coupled models, special emphasis has been placed on numerical robustness and efficiency. To this end, the geochemical reactions are solved in parallel by balancing the computational load over multiple threads. First, a benchmark exercise is used to test the reliability of iCP regarding flow and reactive transport. Then, a large scale thermo-hydro-chemical (THC) problem is solved to show the code capabilities. The results of the verification exercise are successfully compared with those obtained using PHREEQC and the application case demonstrates the scalability of a large scale model, at least up to 32 threads.

MHD Energy Bypass Scramjet Performance with Real Gas Effects

NASA Technical Reports Server (NTRS)

Park, Chul; Mehta, Unmeel B.; Bogdanoff, David W.

2000-01-01

The theoretical performance of a scramjet propulsion system incorporating an magneto-hydro-dynamic (MHD) energy bypass scheme is calculated. The one-dimensional analysis developed earlier, in which the theoretical performance is calculated neglecting skin friction and using a sudden-freezing approximation for the nozzle flow, is modified to incorporate the method of Van Driest for turbulent skin friction and a finite-rate chemistry calculation in the nozzle. Unlike in the earlier design, in which four ramp compressions occurred in the pitch plane, in the present design the first two ramp compressions occur in the pitch plane and the next two compressions occur in the yaw plane. The results for the simplified design of a spaceliner show that (1) the present design produces higher specific impulses than the earlier design, (2) skin friction substantially reduces thrust and specific impulse, and (3) the specific impulse of the MHD-bypass system is still better than the non-MHD system and typical rocket over a narrow region of flight speeds and design parameters. Results suggest that the energy management with MHD principles offers the possibility of improving the performance of the scramjet. The technical issues needing further studies are identified.

Effect of Surface Roughness on Polymer Drag Reduction with a High-Reynolds-Number Turbulent Boundary Layer

NASA Astrophysics Data System (ADS)

Elbing, Brian; Dowling, David; Solomon, Michael; Bian, Sherry; Ceccio, Steven

2007-11-01

A recent experiment at the U.S. Navy's Large Cavitation Channel (LCC) investigated the effect of wall roughness on wall-injection polymer drag reduction (PDR) within a high-Reynolds-number (10^7 to 2x10^8 based on downstream distance) turbulent boundary layer (TBL). Testing was performed in two parts: 1) PDR experiment on a 12.9 m long, 3.05 m wide hydro-dynamically smooth flat plate and 2) PDR experiment on the same model with the entire surface roughened. The roughness was produced by blowing glass beads into epoxy paint that was applied to the entire model. The roughened model had an average roughness height ranging between 307 and 1154 μm. Drag reduction was determined using six, stream-wise located integrated skin-friction balances. In addition to skin-friction measurements, sampling was performed at three stream-wise located ports. The sampling ports were used to determine the amount of degradation, if any, caused by the turbulent flow on the polymer. Both the skin-friction measurements and sampling analysis indicates that wall roughness in a turbulent boundary layer significantly increases degradation of the polymer solution.

Feasibility study of tuned liquid column damper for ocean wave energy extraction

NASA Astrophysics Data System (ADS)

Wong, Yihong; King, Yeong-Jin; Lai, An-Chow; Chong, Kok-Keong; Lim, Boon-Han

2017-04-01

Intermittent nature and low efficiency are the major issues in renewable energy supply. To overcome these issues, one of the possible methods is through a hybrid system where multiple sources of renewable energy are combined to compensate each other's weaknesses. The hybrid of solar energy and wave energy becomes possible through the introduction of a stable floating platform which enables solar energy generation above it and wave energy harvesting underneath it. This paper is intended to study the feasibility of harnessing ocean wave energy using a tuned liquid column damper (TLCD), a type of passive damping device that is designed to suppress externally induced vibration force at a specific frequency range. The proposed TLCD is to be implemented within a floating offshore structure to serve as a vibration mitigating mechanism by reducing the dynamic response of the structure and simultaneously utilize the flowing motion of liquid within the TLCD for generating electricity. The constructed TLCD prototype is tuned according to theoretical study and tested using a shaking table with a predetermined frequency range. The oscillating motion of water within the TLCD and the potential of installation of hydro turbine generator in term of recoverable amount of energy are studied.

From single cilia to collective waves in human airway ciliated tissues

NASA Astrophysics Data System (ADS)

Cicuta, Pietro; Chioccioli, Maurizio; Feriani, Luigi; Pellicciotta, Nicola; Kotar, Jurij

I will present experimental results on activity of motile cilia on various scales: from waveforms on individual cilia to the synchronised motion in cilia carpets of airway cells. Model synthetic experiments have given us an understanding of how cilia could couple with each other through forces transmitted by the fluid, and thus coordinate to beat into well organized waves (previous work is reviewed in Annu. Rev. Condens. Matter Phys. 7, 1-26 (2016)). Working with live imaging of airway human cells at the different scales, we can now test whether the biological system satisfies the ``simple'' behavior expected of the fluid flow coupling, or if other factors of mechanical forces transmission need to be accounted for. In general being able to link from the scale of molecular biological activity up to the phenomenology of collective dynamics requires to understand the relevant physical mechanism. This understanding then allows informed diagnostics (and perhaps therapeutic) approaches to a variety of diseases where mucociliary clearance in the airways is compromised. We have started exploring particularly cystic fibrosis, where the rheological properties of the mucus are affected and prevent efficient cilia synchronization. ERC Grant HydroSync.

NOAA's National Water Model - Integration of National Water Model with Geospatial Data creating Water Intelligence

NASA Astrophysics Data System (ADS)

Clark, E. P.; Cosgrove, B.; Salas, F.

2016-12-01

As a significant step forward to transform NOAA's water prediction services, NOAA plans to implement a new National Water Model (NWM) Version 1.0 in August 2016. A continental scale water resources model, the NWM is an evolution of the WRF-Hydro architecture developed by the National Center for Atmospheric Research (NCAR). The NWM will provide analyses and forecasts of flow for the 2.7 million stream reaches nationwide in the National Hydrography Dataset Plus v2 (NHDPlusV2) jointly developed by the USGS and EPA. The NWM also produces high-resolution water budget variables of snow, soil moisture, and evapotranspiration on a 1-km grid. NOAA's stakeholders require additional decision support application to be built on these data. The Geo-intelligence division of the Office of Water Prediction is building new products and services that integrate output from the NWM with geospatial datasets such as infrastructure and demographics to better estimate the impacts dynamic water resource states on community resiliency. This presentation will detail the methods and underlying information to produce prototypes water resources intelligence that is timely, actionable and credible. Moreover, it will to explore the NWM capability to support sector-specific decision support services.

A vision-based tool for the control of hydraulic structures in sewer systems

NASA Astrophysics Data System (ADS)

Nguyen, L.; Sage, D.; Kayal, S.; Jeanbourquin, D.; Rossi, L.

2009-04-01

During rain events, the total amount of the wastewater/storm-water mixture cannot be treated in the wastewater treatment plant; the overflowed water goes directly into the environment (lakes, rivers, streams) via devices called combined sewers overflows (CSOs). This water is untreated and is recognized as an important source of pollution. In most cases, the quantity of overflowed water is unknown due to high hydraulic turbulences during rain events; this quantity is often significant. For this reason, the monitoring of the water flow and the water level is of crucial environmental importance. Robust monitoring of sewer systems is a challenging task to achieve. Indeed, the environment inside sewers systems is inherently harsh and hostile: constant humidity of 100%, fast and large water level changes, corrosive atmosphere, presence of gas, difficult access, solid debris inside the flow. A flow monitoring based on traditional probes placed inside the water (such as Doppler flow meter) is difficult to conduct because of the solid material transported by the flow. Probes placed outside the flow such as ultrasonic water level probes are often used; however the measurement is generally done on only one particular point. Experience has shown that the water level in CSOs during rain events is far from being constant due to hydraulic turbulences. Thus, such probes output uncertain information. Moreover, a check of the data reliability is impossible to achieve. The HydroPix system proposes a novel approach to the monitoring of sewers based on video images, without contact with the water flow. The goal of this system is to provide a monitoring tool for wastewater system managers (end-users). The hardware was chosen in order to suit the harsh conditions of sewers system: Cameras are 100% waterproof and corrosion-resistant; Infra-red LED illumination systems are used (waterproof, low power consumption); A waterproof case contains the registration and communication system. The monitoring software has the following requirements: visual analysis of particular hydraulic behavior, automatic vision-based flow measurements, automatic alarm system for particular events (overflows, risk of flooding, etc), database for data management (images, events, measurements, etc.), ability to be controlled remotely. The software is implemented in modular server/client architecture under LabVIEW development system. We have conducted conclusive in situ tests in various sewers configurations (CSOs, storm-water sewerage, WWTP); they have shown the ability of the HydroPix to perform accurate monitoring of hydraulic structures. Visual information demonstrated a better understanding of the flow behavior in complex and difficult environment.

Effects of Interfaces on Dynamics in Micro-Fluidic Devices: Slip-Boundaries’ Impact on Rotation Characteristics of Polar Liquid Film Motors

NASA Astrophysics Data System (ADS)

Jiang, Su-Rong; Liu, Zhong-Qiang; Amos Yinnon, Tamar; Kong, Xiang-Mu

2017-05-01

A new approach for exploring effects of interfaces on polar liquids is presented. Their impact on the polar liquid film motor (PLFM) - a novel micro-fluidic device - is studied. We account for the interface’s impact by modeling slip boundary effects on the PLFM’s electro-hydro-dynamical rotations. Our analytical results show as k={l}s/R increases (with {l}s denoting the slip length resulting from the interface’s impact on the film’s properties, k > -1 and R denoting the film’s radius): (a) PLFMs subsequently exhibit rotation characteristics under “negative-”, “no-”, “partial-” and “perfect-” slip boundary conditions; (b) The maximum value of the linear velocity of the steady rotating film increases linearly and its location approaches the film’s border; (c) The decay of the angular velocities’ dependency on the distance from the center of the film slows down, resulting in a macroscopic flow near the boundary. With our calculated rotation speed distributions consistent with the existing experimental ones, research aiming at fitting computed to measured distributions promises identifying the factors affecting {l}s, e.g., solid-fluid potential interactions and surface roughness. The consistency also is advantageous for optimizing PLFM’s applications as micro-washers, centrifuges, mixers in the lab-on-a-chip. Supported by National Natural Science Foundation of China under Grant Nos. 11302118, 11275112, and Natural Science Foundation of Shandong Province under Grant No. ZR2013AQ015

Geochemical responses of forested catchments to bark beetle infestation: Evidence from high frequency in-stream electrical conductivity monitoring

NASA Astrophysics Data System (ADS)

Su, Ye; Langhammer, Jakub; Jarsjö, Jerker

2017-07-01

Under the present conditions of climate warming, there has been an increased frequency of bark beetle-induced tree mortality in Asia, Europe, and North America. This study analyzed seven years of high frequency monitoring of in-stream electrical conductivity (EC), hydro-climatic conditions, and vegetation dynamics in four experimental catchments located in headwaters of the Sumava Mountains, Central Europe. The aim was to determine the effects of insect-induced forest disturbance on in-stream EC at multiple timescales, including annual and seasonal average conditions, daily variability, and responses to individual rainfall events. Results showed increased annual average in-stream EC values in the bark beetle-infected catchments, with particularly elevated EC values during baseflow conditions. This is likely caused by the cumulative loading of soil water and groundwater that discharge excess amounts of substances such as nitrogen and carbon, which are released via the decomposition of the needles, branches, and trunks of dead trees, into streams. Furthermore, we concluded that infestation-induced changes in event-scale dynamics may be largely responsible for the observed shifts in annual average conditions. For example, systematic EC differences between baseflow conditions and event flow conditions in relatively undisturbed catchments were essentially eliminated in catchments that were highly disturbed by bark beetles. These changes developed relatively rapidly after infestation and have long-lasting (decadal-scale) effects, implying that cumulative impacts of increasingly frequent bark beetle outbreaks may contribute to alterations of the hydrogeochemical conditions in more vulnerable mountain regions.

75 FR 17403 - Great Bay Hydro Corporation; Notice of Application for Amendment of License and Soliciting...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-06

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 2306-041] Great Bay Hydro.... b. Project No.: 2306-041. c. Date Filed: March 1, 2010. d. Applicant: Great Bay Hydro Corporation. e...-825r. h. Applicant Contact: Mr. William C. Rodgers, Director of Marketing, Great Bay Hydro Corporation...

78 FR 77118 - KC Small Hydro, LLC; Notice of Amended Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-20

..., Motions To Intervene, and Competing Applications On May 28, 2013, KC Scoby Hydro, LLC, filed an... 28, 2013, application and sent an acceptance letter to KC Scoby Hydro, LLC. Subsequently, On October 28, 2013, KC Scoby Hydro, LLC, amended its preliminary permit application to change its name to KC...

40 CFR 721.1880 - Borate(1-), tris(acetato-.kappa.O)hydro-, sodium, (T-4)-.

Code of Federal Regulations, 2010 CFR

2010-07-01

...)hydro-, sodium, (T-4)-. 721.1880 Section 721.1880 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.1880 Borate(1-), tris(acetato-.kappa.O)hydro-, sodium... substance identified as borate(1-), tris(acetato-.kappa.O)hydro-, sodium, (T-4)- (PMN P-00-0922; CAS No...

77 FR 55202 - Oliver Hydro LLC; Notice of Application Accepted for Filing and Soliciting Motions To Intervene...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-07

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13005-003] Oliver Hydro LLC... filed: December 14, 2011. d. Applicant: Oliver Hydro LLC. e. Name of Project: William Bacon Oliver Lock... according to the following Hydro Licensing Schedule. Revisions to the schedule will be made as appropriate...

78 FR 71602 - Lock 12 Hydro Partners, LLC; Notice of Proposed Restricted Service List for a Programmatic Agreement

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-29

... Hydroelectric Project] Lock 12 Hydro Partners, LLC; Notice of Proposed Restricted Service List for a... Hydro Partners, LLC, as the applicant for Project No. 13214-003, is invited to participate in... Kinloch, Lock 14 Hydro Partners, 414 South Wenzel St., Louisville, KY 40204. Any person on the official...

75 FR 11527 - KC Hydro LLC; Notice of Competing Preliminary Permit Application Accepted for Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-11

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13617-000] KC Hydro LLC..., 2010. On November 6, 2009, KC Hydro LLC filed an application for a preliminary permit, pursuant to... Sackheim, KC Hydro LLC, 5096 Cocoa Palm Way, Fair Oaks, CA 95628, phone: (916) 962-2271, e-mail: oregon...

40 CFR 721.1880 - Borate(1-), tris(acetato-.kappa.O)hydro-, sodium, (T-4)-.

Code of Federal Regulations, 2011 CFR

2011-07-01

...)hydro-, sodium, (T-4)-. 721.1880 Section 721.1880 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.1880 Borate(1-), tris(acetato-.kappa.O)hydro-, sodium... substance identified as borate(1-), tris(acetato-.kappa.O)hydro-, sodium, (T-4)- (PMN P-00-0922; CAS No...

76 FR 41236 - FPL Energy Maine Hydro, LLC; Notice of Application Accepted for Filing and Soliciting Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-13

... Hydro, LLC; Notice of Application Accepted for Filing and Soliciting Comments Take notice that the....: 2283-064. c. Date Filed: March 25, 2011. d. Applicant: FPL Energy Maine Hydro, LLC. e. Name of Project... Land/Trail Management Plan issued March 25, 2010, FPL Energy Maine Hydro, LLC (licensee) filed an...

78 FR 12304 - Lock+ Hydro Friends Fund XLII, LLC; Notice of Application Ready for Environmental Analysis and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-22

... Friends Fund XLII, LLC; Notice of Application Ready for Environmental Analysis and Soliciting Comments...+ Hydro Friends Fund XLII, LLC. e. Name of Project: Braddock Locks and Dam Hydroelectric Project. f...\\ Hydro Friends Fund XLII, LLC, c/o Hydro Green Energy, LLC, 900 Oakmont Lane, Suite 310, Westmont, IL...

78 FR 34570 - Special Local Regulations; Pro Hydro-X Tour, Lake Dora; Tavares, FL

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-10

...-AA08 Special Local Regulations; Pro Hydro-X Tour, Lake Dora; Tavares, FL AGENCY: Coast Guard, DHS... waters of Lake Dora in Tavares, Florida, during the Pro Hydro-X Tour, a series of high-speed personal... published a notice of proposed rulemaking (NPRM) entitled Special Local Regulations; Pro Hydro-X Tour, Lake...

Developing of Watershed Radionuclide Transport Model DHSVM-R as Modification and Extension of Distributed Hydrological and Sediment Dynamics Model DHSVM

NASA Astrophysics Data System (ADS)

Zheleznyak, M.; Kivva, S.; Onda, Y.; Nanba, K.; Wakiyama, Y.; Konoplev, A.

2015-12-01

The reliable modeling tools for prediction wash - off radionuclides from watersheds are needed as for assessment the consequences of accidental and industrial releases of radionuclides, as for soil erosion studies using the radioactive tracers. The distributed model of radionuclide transport through watershed in exchangeable and nonexchangeable forms in solute and with sediments was developed and validated for small Chernobyl watersheds in 90th within EU SPARTACUS project (van der Perk et al., 1996). New tendency is coupling of radionuclide transport models and the widely validated hydrological distributed models. To develop radionuclide transport model DHSVM-R the open source Distributed Hydrology Soil Vegetation Model -DHSVM http://www.hydro.washington.edu/Lettenmaier/Models/DHSVM was modified and extended. The main changes provided in the hydrological and sediment transport modules of DHSVM are as follows: Morel-Seytoux infiltration model is added; four-directions schematization for the model's cells flows (D4) is replaced by D8 approach; the finite-difference schemes for solution of kinematic wave equations for overland water flow, stream net flow, and sediment transport are replaced by new computationally efficient scheme. New radionuclide transport module, coupled with hydrological and sediment transport modules, continues SPARTACUS's approach, - it describes radionuclide wash-off from watershed and transport via stream network in soluble phase and on suspended sediments. The hydrological module of DHSVM-R was calibrated and validated for the watersheds of Ukrainian Carpathian mountains and for the subwatersheds of Niida river flowing 137Cs in solute and with suspended sediments to Pacific Ocean at 30 km north of the Fukushima Daiichi NPP. The modules of radionuclide and sediment transport were calibrated and validated versus experimental data for USLE experimental plots in Fukushima Prefecture and versus monitoring data collected in Niida watershed. The role of sediment transport in radionuclide wash-off from mountain and lowland watersheds is analyzed in comparison of modeling results for Chernobyl and Fukushima watersheds.

Linear and Non-linear Information Flows In Rainfall Field

NASA Astrophysics Data System (ADS)

Molini, A.; La Barbera, P.; Lanza, L. G.

The rainfall process is the result of a complex framework of non-linear dynamical in- teractions between the different components of the atmosphere. It preserves the com- plexity and the intermittent features of the generating system in space and time as well as the strong dependence of these properties on the scale of observations. The understanding and quantification of how the non-linearity of the generating process comes to influence the single rain events constitute relevant research issues in the field of hydro-meteorology, especially in those applications where a timely and effective forecasting of heavy rain events is able to reduce the risk of failure. This work focuses on the characterization of the non-linear properties of the observed rain process and on the influence of these features on hydrological models. Among the goals of such a survey is the research of regular structures of the rainfall phenomenon and the study of the information flows within the rain field. The research focuses on three basic evo- lution directions for the system: in time, in space and between the different scales. In fact, the information flows that force the system to evolve represent in general a connection between the different locations in space, the different instants in time and, unless assuming the hypothesis of scale invariance is verified "a priori", the different characteristic scales. A first phase of the analysis is carried out by means of classic statistical methods, then a survey of the information flows within the field is devel- oped by means of techniques borrowed from the Information Theory, and finally an analysis of the rain signal in the time and frequency domains is performed, with par- ticular reference to its intermittent structure. The methods adopted in this last part of the work are both the classic techniques of statistical inference and a few procedures for the detection of non-linear and non-stationary features within the process starting from measured data.

Modelling surface water-groundwater interaction with a conceptual approach: model development and application in New Zealand

NASA Astrophysics Data System (ADS)

Yang, J.; Zammit, C.; McMillan, H. K.

2016-12-01

As in most countries worldwide, water management in lowland areas is a big concern for New Zealand due to its economic importance for water related human activities. As a result, the estimation of available water resources in these areas (e.g., for irrigation and water supply purpose) is crucial and often requires an understanding of complex hydrological processes, which are often characterized by strong interactions between surface water and groundwater (usually expressed as losing and gaining rivers). These processes are often represented and simulated using integrated physically based hydrological models. However models with physically based groundwater modules typically require large amount of non-readily available geologic and aquifer information and are computationally intensive. Instead, this paper presents a conceptual groundwater model that is fully integrated into New Zealand's national hydrological model TopNet based on TopModel concepts (Beven, 1992). Within this conceptual framework, the integrated model can simulate not only surface processes, but also groundwater processes and surface water-groundwater interaction processes (including groundwater flow, river-groundwater interaction, and groundwater interaction with external watersheds). The developed model was applied to two New Zealand catchments with different hydro-geological and climate characteristics (Pareora catchment in the Canterbury Plains and Grey catchment on the West Coast). Previous studies have documented strong interactions between the river and groundwater, based on the analysis of a large number of concurrent flow measurements and associated information along the river main stem. Application of the integrated hydrological model indicates flow simulation (compared to the original hydrological model conceptualisation) during low flow conditions are significantly improved and further insights on local river dynamics are gained. Due to its conceptual characteristics and low level of data requirement, the integrated model could be used at local and national scales to improve the simulation of hydrological processes in non-topographically driven areas (where groundwater processes are important), and to assess impact of climate change on the integrated hydrological cycle in these areas.

Enhancing Access to Drought Information Using the CUAHSI Hydrologic Information System

NASA Astrophysics Data System (ADS)

Schreuders, K. A.; Tarboton, D. G.; Horsburgh, J. S.; Sen Gupta, A.; Reeder, S.

2011-12-01

The National Drought Information System (NIDIS) Upper Colorado River Basin pilot study is investigating and establishing capabilities for better dissemination of drought information for early warning and management. As part of this study we are using and extending functionality from the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) Hydrologic Information System (HIS) to provide better access to drought-related data in the Upper Colorado River Basin. The CUAHSI HIS is a federated system for sharing hydrologic data. It is comprised of multiple data servers, referred to as HydroServers, that publish data in a standard XML format called Water Markup Language (WaterML), using web services referred to as WaterOneFlow web services. HydroServers can also publish geospatial data using Open Geospatial Consortium (OGC) web map, feature and coverage services and are capable of hosting web and map applications that combine geospatial datasets with observational data served via web services. HIS also includes a centralized metadata catalog that indexes data from registered HydroServers and a data access client referred to as HydroDesktop. For NIDIS, we have established a HydroServer to publish drought index values as well as the input data used in drought index calculations. Primary input data required for drought index calculation include streamflow, precipitation, reservoir storages, snow water equivalent, and soil moisture. We have developed procedures to redistribute the input data to the time and space scales chosen for drought index calculation, namely half monthly time intervals for HUC 10 subwatersheds. The spatial redistribution approaches used for each input parameter are dependent on the spatial linkages for that parameter, i.e., the redistribution procedure for streamflow is dependent on the upstream/downstream connectivity of the stream network, and the precipitation redistribution procedure is dependent on elevation to account for orographic effects. A set of drought indices are then calculated from the redistributed data. We have created automated data and metadata harvesters that periodically scan and harvest new data from each of the input databases, and calculates extensions to the resulting derived data sets, ensuring that the data available on the drought server is kept up to date. This paper will describe this system, showing how it facilitates the integration of data from multiple sources to inform the planning and management of water resources during drought. The system may be accessed at http://drought.usu.edu.

Long-term 4D Geoelectrical Imaging of Moisture Dynamics in an Active Landslide

NASA Astrophysics Data System (ADS)

Uhlemann, S.; Chambers, J. E.; Wilkinson, P. B.; Maurer, H.; Meldrum, P.; Gunn, D.; Smith, A.; Dijkstra, T.

2016-12-01

Landslides are a major natural hazard, endangering communities and infrastructure worldwide. Mitigating landslide risk relies on understanding causes and triggering processes, which are often linked to moisture dynamics in slopes causing material softening and elevated pore water pressures. Geoelectrical monitoring is frequently applied to study landslide hydrology. However, its sensitivity to sensor movements has been a challenge for long-term studies on actively failing slopes. Although 2D data acquisition has previously been favoured, it provides limited resolution and relatively poor representation of important 3D landslide structures. We present a novel methodology to incorporate electrode movements into a time-lapse 3D inversion workflow, resulting in a virtually artefact-free time-series of resistivity models. Using temperature correction and laboratory hydro-geophysical relationships, resistivity models are translated into models of moisture content. The data span more than three years, enabling imaging of processes pre- and post landslide reactivation. In the two years before reactivation, the models showed surficial wetting and drying, drainage pathways, and deeper groundwater dynamics. During reactivation, exceptionally high moisture contents were imaged throughout the slope, which was confirmed by independent measurements. Preferential flow was imaged that stabilized parts of the landslide by diverting moisture, and thus dissipating pore pressures, from the slip surface. The results highlight that moisture levels obtained from resistivity monitoring may provide a better activity threshold than rainfall intensity. Based on this work, pro-active remediation measures could be designed and effective early-warning systems implemented. Eventually, resistivity monitoring that can account for moving electrodes may provide a new means for pro-active mitigation of landslide risk, especially for communities and critical infrastructure.

Engineering diagnostics for vortex-induced stay vanes cracks in a Francis turbine

NASA Astrophysics Data System (ADS)

D'Agostini Neto, Alexandre; Gissoni, Humberto, Dr.; Gonçalves, Manuel, Dr.; Cardoso, Rogério; Jung, Alexander, Dr.; Meneghini, Julio, Prof.

2016-11-01

Despite the fact that vortex-induced vibration (VIV) in hydraulic turbines components (especially in stay vanes) is a well-known phenomenon, it still remains challenging for operation and maintenance teams in several power plants around the world. Since the first publication of a similar problem in 1967, literature shows that at least 27 other turbines witnessed strong stay vane vibrations associated with vortex shedding. Recurrent stay vane cracks in a 250 MW Francis turbine in Brazil motivated an engineering study involving prototype measurements, structural and Computational Fluid Dynamics (CFD) analysis in order to determine a proper geometry modification that could eliminate the periodic vortex wake generated at the stay vanes trailing edge. First cracks appeared in 1978 just after the machine was put into operation. A study published in 1982 associated these cracks with dynamic excitations caused by the water flow at high flow conditions. New stay vane profiles were proposed and executed as well as improved welding recommendations. Cracks however, continued to appear requiring welding repairs roughly every two years. Although Voith Hydro was not the original equipment manufacturer for these units, the necessary information was available to study the issue and propose and execute new stay vane profiles. This paper details the approach taken for the study. First, indirect vibration measurements were used to determine vibration frequencies to help to characterize the affected mode shapes. These results were compared to finite element (FE) calculations. Strain gage measurements performed afterwards confirmed the conclusions of this analysis. Next, transient CFD calculations were run to reproduce the measured phenomenon and to serve as a basis for a new stay vane geometry. This modification was then implemented in the actual turbine stay vanes. A new set of indirect vibration measurements indicated the effectiveness of the proposed solution. Final confirmation will come from new strain gage measurements.

Effects of particle size and hydro-thermal treatment of feed on performance and stomach health in fattening pigs.

PubMed

Liermann, Wendy; Berk, Andreas; Böschen, Verena; Dänicke, Sven

2015-01-01

Effects of grinding and hydro-thermal treatment of feed on growth performance, slaughter traits, nutrient digestibility, stomach content and stomach health were examined by using 96 crossbred fattening pigs. Pigs were fed a grain-soybean meal-based diet processed by various technical treatments. Feeding groups differed in particle size after grinding (finely vs. coarsely ground feed) and hydro-thermal treatment (without hydro-thermal treatment, pelleting, expanding, expanding and pelleting). Fine grinding and hydro-thermal treatment showed significant improvements on the digestibility of crude nutrients and content of metabolisable energy. Hydro-thermal treatment influenced average daily gain (ADG) and average daily feed intake (DFI) significantly. Finely ground pelleted feed without expanding enhanced performances by increasing ADG and decreasing feed-to-gain ratio (FGR) of fattening pigs. Coarsely ground feed without hydro-thermal treatment resulted in the highest ADG and DFI, however also in the highest FGR. Expanded feed decreased DFI and ADG. Slaughter traits were not affected by treatments. Coarsely ground feed without hydro-thermal treatment had protective effects on the health of gastric pars nonglandularis, however, pelleting increased gastric lesions. Hydro-thermal treatment, especially expanding, resulted in clumping of stomach content which possibly induced satiety by slower ingesta passage rate and thus decreased feed intake. Pigs fed pelleted feed showed less pronounced development of clumps in stomach content compared with expanded feed.

Influence of clay particles on microfluidic-based preparation of hydrogel composite microsphere

NASA Astrophysics Data System (ADS)

Hong, Joung Sook

2016-05-01

For the successful fabrication of a hydrogel composite microsphere, this study aimed to investigate the influence of clay particles on microsphere formation in a microfluidic device which has flow focusing and a 4.5:1 contraction channel. A poly alginic acid solution (2.0 wt.%) with clay particles was used as the dispersed phase to generate drops in an oil medium, which then merged with drops of a CaCl2 solution for gelation. Drop generations were observed with different flow rates and particles types. When the flow rate increased, drop generation was enhanced and drop size decreased by the build-up of more favorable hydrodynamic flow conditions to detach the droplets. The addition of a small amount of particles insignificantly changed the drop generation behavior even though it reduced interfacial tension and increased the viscosity of the solution. Instead, clays particles significantly affected hydro-gelation depending on the hydrophobicity of particles, which produced further heterogeneity in the shape and size of microsphere.

Innovation in monitoring: The U.S. Geological Survey Sacramento–San Joaquin River Delta, California, flow-station network

USGS Publications Warehouse

Burau, Jon; Ruhl, Cathy; Work, Paul A.

2016-01-29

The U.S. Geological Survey (USGS) installed the first gage to measure the flow of water into California’s Sacramento–San Joaquin River Delta from the Sacramento River in the late 1800s. Today, a network of 35 hydro-acoustic meters measure flow throughout the delta. This region is a critical part of California’s freshwater supply and conveyance system. With the data provided by this flow-station network—sampled every 15 minutes and updated to the web every hour—state and federal water managers make daily decisions about how much freshwater can be pumped for human use, at which locations, and when. Fish and wildlife scientists, working with water managers, also use this information to protect fish species affected by pumping and loss of habitat. The data are also used to help determine the success or failure of efforts to restore ecosystem processes in what has been called the “most managed and highly altered” watershed in the country.

PEVC-FMDF for Large Eddy Simulation of Compressible Turbulent Flows

NASA Astrophysics Data System (ADS)

Nouri Gheimassi, Arash; Nik, Mehdi; Givi, Peyman; Livescu, Daniel; Pope, Stephen

2017-11-01

The filtered density function (FDF) closure is extended to a ``self-contained'' format to include the subgrid scale (SGS) statistics of all of the hydro-thermo-chemical variables in turbulent flows. These are the thermodynamic pressure, the specific internal energy, the velocity vector, and the composition field. In this format, the model is comprehensive and facilitates large eddy simulation (LES) of flows at both low and high compressibility levels. A transport equation is developed for the joint ``pressure-energy-velocity-composition filtered mass density function (PEVC-FMDF).'' In this equation, the effect of convection appears in closed form. The coupling of the hydrodynamics and thermochemistry is modeled via a set of stochastic differential equation (SDE) for each of the transport variables. This yields a self-contained SGS closure. For demonstration, LES is conducted of a turbulent shear flow with transport of a passive scalar. The consistency of the PEVC-FMDF formulation is established, and its overall predictive capability is appraised via comparison with direct numerical simulation (DNS) data.

78 FR 26768 - Great Lakes Hydro America, LLC; Notice of Intent To File License Application, Filing of Pre...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-08

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 2520-072] Great Lakes Hydro...: March 1, 2013. d. Submitted By: Great Lakes Hydro America, LLC. e. Name of Project: Mattaceunk... Preservation at 36 CFR 800.2. l. With this notice, we are designating Great Lakes Hydro America, LLC as the...

76 FR 42124 - River Bounty, Inc.; Renew Hydro, LLC; Notice of Transfer of Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-18

....; Renew Hydro, LLC; Notice of Transfer of Exemption 1. By letters filed April 19, April 20, and May 4... Hydroelectric Project No. 5730, originally issued June 9, 1982,\\1\\ has been transferred to Renew Hydro, LLC. The... exemption does not require Commission approval. \\1\\ American Hydro Power Co., 19 FERC ] 62,426 (1982). 2...

78 FR 71603 - Lock 14 Hydro Partners, LLC; Notice of Proposed Restricted Service List for a Programmatic Agreement

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-29

... Heidelberg Hydroelectric Project] Lock 14 Hydro Partners, LLC; Notice of Proposed Restricted Service List for... listed below. Lock 14 Hydro Partners, LLC, as the applicant for Project No. 13213-003, is invited to... Kinloch, Lock 14 Hydro Partners, 414 South Wenzel St., Louisville, KY 40204. Any person on the official...

77 FR 68765 - Lock+ Hydro Friends Fund XLII, LLC; Notice of Scoping Meetings and Environmental Site Review and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-16

... Friends Fund XLII, LLC; Notice of Scoping Meetings and Environmental Site Review and Soliciting Scoping.... c. Date filed: September 17, 2012. d. Applicant: Lock+ Hydro Friends Fund XLII, LLC. e. Name of...)-825(r). h. Applicant Contact: Mr. Mark R. Stover, Lock+\\TM\\ Hydro Friends Fund XLII, LLC, c/o Hydro...

78 FR 34092 - Lock+ Hydro Friends Fund XXX, LLC; FFP Project 121, LLC; Notice of Competing Preliminary Permit...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-06

.... 14504-000] Lock+ Hydro Friends Fund XXX, LLC; FFP Project 121, LLC; Notice of Competing Preliminary... Applications Lock+ Hydro Friends Fund XXX, LLC and FFP Project 121, LLC filed preliminary permit applications... regular business day. See id. at 385.2001(a)(2). Lock+ Hydro Friends Fund XXX, LLC's application is for a...

77 FR 60971 - Lock+ Hydro Friends Fund XLII, LLC; Notice of Application Tendered for Filing With the Commission...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-05

... Friends Fund XLII, LLC; Notice of Application Tendered for Filing With the Commission and Soliciting... No.: 13739-002. c. Date filed: September 17, 2012. d. Applicant: Lock+ Hydro Friends Fund XLII, LLC.... 791 (a)-825(r). h. Applicant Contact: Mr. Mark R. Stover, Lock+ TM Hydro Friends Fund XLII, c/o Hydro...

77 FR 9222 - Lock+ Hydro Friends Fund XLII, LLC; Notice of Intent To File License Application, Filing of Pre...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-16

... Friends Fund XLII, LLC; Notice of Intent To File License Application, Filing of Pre-Application Document.... Date Filed: December 23, 2011. d. Submitted By: Lock+ Hydro Friends Fund XLII, LLC. e. Name of Project... regulations. h. Potential Applicant Contact: Mr. Mark R. Stover, Lock+\\TM\\ Hydro Friends Fund XLII, c/o Hydro...