J. Hydrol. Hydromech., Vol. 63, No. 1, 2015, p. 1 - 12, doi: 10.1515/johh-2015-0005
Scientific Paper, English
Sape A. Miedema: A head loss model for homogeneous slurry transport for medium sized
particles
Full Text in PDF 345 DOWNLOADS
- Slurry transport in horizontal and vertical pipelines is one of the major means of transport of sands and gravels
in the dredging industry. There exist 4 main flow regimes, the fixed or stationary bed regime, the sliding bed regime, the
heterogeneous flow regime and the homogeneous flow regime. Of course the transitions between the regimes are not
very sharp, depending on parameters like the particle size distribution. The focus in this paper is on the homogeneous
regime. Often the so called equivalent liquid model (ELM) is applied, however many researchers found hydraulic
gradients smaller than predicted with the ELM, but larger that the hydraulic gradient of liquid. Talmon (2011, 2013)
derived a fundamental equation (method) proving that the hydraulic gradient can be smaller than predicted by the ELM,
based on the assumption of a particle free viscous sub-layer. He used a 2D velocity distribution without a concentration
distribution.
In this paper 5 methods are described (and derived) to determine the hydraulic gradient in homogeneous flow, of
which the last method is based on pipe flow with a concentration distribution. It appears that the use of von Driest
(Schlichting, 1968) damping, if present, dominates the results, however applying a concentration distribution may
neutralise this. The final equation contains both the damping and a concentration distribution giving the possibility to
calibrate the constant in the equation with experimental data. The final equation is flexible and gives a good match with
experimental results in vertical and horizontal pipelines for a value of ACv = 1.3. Data of horizontal experiments Dp =
0.05 – 0.30 m, d = 0.04 mm, vertical experiments Dp = 0.026 m, d = 0.125, 0.345, 0.560, and 0.750 mm.
KEY WORDS: Slurry transport; Homogeneous transport; Viscous sub layer; Mixing length.
Address:
- Sape A. Miedema, Delft University of Technology, Mekelweg 2, 2628 CD Delft, The Netherlands. (Corresponding author. Tel.:+31-15-2788359 Fax.: Email: s.a.miedema@tudelft.nl)
J. Hydrol. Hydromech., Vol. 63, No. 1, 2015, p. 13 - 20, doi: 10.1515/johh-2015-0008
Scientific Paper, English
K.M. Assefa, D.R. Kaushal: A comparative study of friction factor correlations for high concentrate slurry
flow in smooth pipes
Full Text in PDF 83 DOWNLOADS
- A number of correlations for friction factor determinations in smooth pipes have been proposed in the past
decades. The accuracy and applicability of these friction factor formulas should be examined. Based on this notion the
paper is designed to provide a comparative study of friction factor correlations in smooth pipes for all flow regimes of
Bingham fluids. Nine models were chosen. The comparisons of the selected equations with the existing experimental
results, which are available in the literature, were expressed through MARE, MRE+, MRE-, RMSE, Ѳ, and S. The
statistical comparisons were also carried out using MSC and AIC. The analyses show that the Wilson-Thomas (1985)
and Morrison (2013) models are best fit models to the experimental data for the Reynolds number up to 40000. Within
this range, both models can be used alternately. But beyond this Re value the discrepancy of the Wilson-Thomas model
is higher than the Morrison model. In view of the fact that the Morrison model requires fewer calculations and
parameters as well as a single equation is used to compute the friction factor for all flow regimes, it is the authors’ advice
to use this model for friction factor estimation for the flow of Bingham fluids in smooth pipes as an alternative to the
Moody chart and other implicit formulae.
KEY WORDS: Bingham fluid; Smooth pipe; Laminar flow; Turbulent flow; Friction factor; Reynolds number; Correlations;
Statistical parameters.
Address:
- K.M. Assefa, Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
- D.R. Kaushal, Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. (Corresponding author. Tel.: Fax.: Email: kaushal@civil.iitd.ac.in)
J. Hydrol. Hydromech., Vol. 63, No. 1, 2015, p. 21 - 28, doi: 10.1515/johh-2015-0006
Scientific Paper, English
Eliška Hasníková, Jiří Pavlásek, Marek Vach: Spatial interpolation of point velocities in stream cross-section
Full Text in PDF 81 DOWNLOADS
- The most frequently used instrument for measuring velocity distribution in the cross-section of small rivers is
the propeller–type current meter. Output of measuring using this instrument is point data of a tiny bulk. Spatial
interpolation of measured data should produce a dense velocity profile, which is not available from the measuring itself.
This paper describes the preparation of interpolation models.
Measuring campaign was realized to obtain operational data. It took place on real streams with different velocity
distributions. Seven data sets were obtained from four cross-sections varying in the number of measuring points, 24–82.
Following methods of interpolation of the data were used in the same context: methods of geometric interpolation
arithmetic mean and inverse distance weighted, the method of fitting the trend to the data thin-plate spline and the
geostatistical method of ordinary kriging. Calibration of interpolation models carried out in the computational program
Scilab is presented. The models were tested with error criteria by cross-validation. Ordinary kriging was proposed to be
the most suitable interpolation method, giving the lowest values of used error criteria among the rest of the interpolation
methods.
KEY WORDS: Open channel; Current meter; Cross-validation; Arithmetic mean; Inverse distance weighted; Thin-plate
spline; Kriging.
Address:
- Eliška Hasníková, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6 – Suchdol, 165 21, Czech Republic. (Corresponding author. Tel.:+420732371341 Fax.: Email: hasnikova@fzp.czu.cz)
- Jiří Pavlásek, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6 – Suchdol, 165 21, Czech Republic.
- Marek Vach, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6 – Suchdol, 165 21, Czech Republic.
J. Hydrol. Hydromech., Vol. 63, No. 1, 2015, p. 29 - 37, doi: 10.1515/johh-2015-0001
Scientific Paper, English
Igor Ljubenkov: Hydrodynamic modeling of stratified estuary: case study of the Jadro River
(Croatia)
Full Text in PDF 230 DOWNLOADS
- The Jadro River with total length of 4.3 km and average annual discharge of 7.9 m3 s–1 is a relatively small
river on the east coast of the Adriatic Sea, close to Split. Field campaign measurements were made to estimate salt
intrusion in the Jadro estuary in July 2012. This measurement confirmed the stratified character of the estuary where
fresh water flows in a thin layer over denser sea water. Furthermore, a numerical model was set up for simulating
unsteady stratified flow without mixing between the layers. The model is applied for the Jadro River and field
measurements are used for calibration. In addition, the steady state of stratification within the estuary is analyzed by a
box model which assumes mixing between layers. Results of the numerical and the box models were compared. The
flushing time estimated with the box model is approximately 1.5 day for summer steady conditions. Numerical analysis
however shows that the residence time is much larger owing to flow unsteadiness.
KEY WORDS: Estuary; Salinity; Numerical model; Box model; Jadro; Croatia.
Address:
- Igor Ljubenkov, Water Development Ltd., Kvaternikova 7, 21000 Split, Croatia. (Corresponding author. Tel.: Fax.: Email: iljubenkov@gmail.com)
J. Hydrol. Hydromech., Vol. 63, No. 1, 2015, p. 38 - 46, doi: 10.1515/johh-2015-0007
Scientific Paper, English
Fatih Unes, Hakan Varcin: Investigation of seasonal thermal flow in a real dam reservoir
using 3-D numerical modeling
Full Text in PDF 57 DOWNLOADS
- Investigations indicate that correct estimation of seasonal thermal stratification in a dam reservoir is very important
for the dam reservoir water quality modeling and water management problems. The main aim of this study is to
develop a hydrodynamics model of an actual dam reservoir in three dimensions for simulating a real dam reservoir flows
for different seasons. The model is developed using nonlinear and unsteady continuity, momentum, energy and k-ε turbulence
model equations. In order to include the Coriolis force effect on the flow in a dam reservoir, Coriolis force parameter
is also added the model equations. Those equations are constructed using actual dimensions, shape, boundary
and initial conditions of the dam and reservoir. Temperature profiles and flow visualizations are used to evaluate flow
conditions in the reservoir. Reservoir flow’s process and parameters are determined all over the reservoir. The mathematical
model developed is capable of simulating the flow and thermal characteristics of the reservoir system for seasonal
heat exchanges. Model simulations results obtained are compared with field measurements obtained from gauging stations
for flows in different seasons. The results show a good agreement with the field measurements.
KEY WORDS: Real dam reservoir; Thermal stratification; Mathematical model; Density flow; Divergence flow.
Address:
- Fatih Unes, Mustafa Kemal University, Engineering Faculty, Civil Engineering Department, Hydraulics Division, 31200, Iskenderun, Hatay, Turkey. (Corresponding author. Tel.: Fax.: Email: funes@mku.edu.tr, fatihunes66@gmail.com)
- Hakan Varcin, Mustafa Kemal University, Engineering Faculty, Civil Engineering Department, Hydraulics Division, 31200, Iskenderun, Hatay, Turkey.
J. Hydrol. Hydromech., Vol. 63, No. 1, 2015, p. 47 - 54, doi: 10.1515/johh-2015-0010
Scientific Paper, English
Karsten Schacht, Bernd Marschner: Treated wastewater irrigation effects on soil hydraulic conductivity and
aggregate stability of loamy soils in Israel
Full Text in PDF 54 DOWNLOADS
- The use of treated wastewater (TWW) for agricultural irrigation becomes increasingly important in water
stressed regions like the Middle East for substituting fresh water (FW) resources. Due to elevated salt concentrations and
organic compounds in TWW this practice has potential adverse effects on soil quality, such as the reduction of hydraulic
conductivity (HC) and soil aggregate stability (SAS). To assess the impact of TWW irrigation in comparison to FW irrigation
on HC, in-situ infiltration measurements using mini disk infiltrometer were deployed in four different long-term
experimental orchard test sites in Israel. Topsoil samples (0–10 cm) were collected for analyzing SAS and determination
of selected soil chemical and physical characteristics.
The mean HC values decreased at all TWW sites by 42.9% up to 50.8% compared to FW sites. The SAS was 11.3%
to 32.4% lower at all TWW sites. Soil electrical conductivity (EC) and exchangeable sodium percentage (ESP) were
generally higher at TWW sites. These results indicate the use of TWW for irrigation is a viable, but potentially deleterious
option, as it influences soil physical and chemical properties.
KEY WORDS: Hydraulic conductivity; Soil aggregate stability; Irrigation; Treated wastewater; Israel.
Address:
- Karsten Schacht, Institute of Geography, Department of Soil Science and Soil Ecology, Ruhr-University Bochum, Universitätsstrasse 150, 44801 Bochum,
Germany. CIHLMU Center for International Health, Department of Infectious Diseases and Tropical Medicine at the University of Munich,
Lepoldstrasse 7, 80802 Munich, Germany. (Corresponding author. Tel.: Fax.: Email: karsten.schacht@rub.de)
- Bernd Marschner, Institute of Geography, Department of Soil Science and Soil Ecology, Ruhr-University Bochum, Universitätsstrasse 150, 44801 Bochum,
Germany.
J. Hydrol. Hydromech., Vol. 63, No. 1, 2015, p. 55 - 62, doi: 10.1515/johh-2015-0003
Scientific Paper, English
David Hernando, Manuel G. Romana: Estimating the rainfall erosivity factor from monthly precipitation data in the
Madrid Region (Spain)
Full Text in PDF 86 DOWNLOADS
- The need for continuous recording rain gauges makes it difficult to determine the rainfall erosivity factor (Rfactor)
of the Universal Soil Loss Equation in regions without good spatial and temporal data coverage. In particular, the
R-factor is only known at 16 rain gauge stations in the Madrid Region (Spain). The objectives of this study were to identify
a readily available estimate of the R-factor for the Madrid Region and to evaluate the effect of rainfall record length
on estimate precision and accuracy. Five estimators based on monthly precipitation were considered: total annual rainfall
(P), Fournier index (F), modified Fournier index (MFI), precipitation concentration index (PCI) and a regression equation
provided by the Spanish Nature Conservation Institute (RICONA). Regression results from 8 calibration stations
showed that MFI was the best estimator in terms of coefficient of determination and root mean squared error, closely followed
by P. Analysis of the effect of record length indicated that little improvement was obtained for MFI and P over 5-
year intervals. Finally, validation in 8 additional stations supported that the equation R = 1.05·MFI computed for a record
length of 5 years provided a simple, precise and accurate estimate of the R-factor in the Madrid Region.
KEY WORDS: Rainfall erosivity; R-factor; Universal Soil Loss Equation; Modified Fournier index; Soil erosion.
Address:
- David Hernando, Department of Civil Engineering – Transport. Technical University of Madrid. Profesor Aranguren 3, 28040 Madrid, Spain. (Corresponding author. Tel.:+34 616 585 256 Fax.: +34 916 633 354 Email: davhernando@gmail.com)
- Manuel G. Romana, Department of Civil Engineering – Transport. Technical University of Madrid. Profesor Aranguren 3, 28040 Madrid, Spain.
J. Hydrol. Hydromech., Vol. 63, No. 1, 2015, p. 63 - 70, doi: 10.1515/johh-2015-0009
Scientific Paper, English
Milan Stojkovic, Stevan Prohaska, Jasna Plavsic: Stochastic structure of annual discharges of large European rivers
Full Text in PDF 68 DOWNLOADS
- Water resource has become a guarantee for sustainable development on both local and global scales.
Exploiting water resources involves development of hydrological models for water management planning. In this paper
we present a new stochastic model for generation of mean annul flows. The model is based on historical characteristics
of time series of annual flows and consists of the trend component, long-term periodic component and stochastic
component. The rest of specified components are model errors which are represented as a random time series. The
random time series is generated by the single bootstrap model (SBM). Stochastic ensemble of error terms at the single
hydrological station is formed using the SBM method. The ultimate stochastic model gives solutions of annual flows and
presents a useful tool for integrated river basin planning and water management studies. The model is applied for ten
large European rivers with long observed period. Validation of model results suggests that the stochastic flows simulated
by the model can be used for hydrological simulations in river basins.
KEY WORDS: Stochastic model; Flow simulation; Long-term periodicity; Single bootstrap model SBM.
Address:
- Milan Stojkovic, Jaroslav Černi Institute for the Development of Water Resources, Jaroslava Černog 80, Belgrade, Serbia. (Corresponding author. Tel.: Fax.: Email: milan.stojkovic@jcerni.co.rs)
- Stevan Prohaska, Jaroslav Černi Institute for the Development of Water Resources, Jaroslava Černog 80, Belgrade, Serbia.
- Jasna Plavsic, University of Belgrade, Faculty of Civil Engineering, Bulevar Kralja Aleksandra 63, Belgrade, Serbia.
J. Hydrol. Hydromech., Vol. 63, No. 1, 2015, p. 71 - 81, doi: 10.1515/johh-2015-0002
Scientific Paper, English
Hana Hlaváčiková, Viliam Novák, Ladislav Holko: On the role of rock fragments and initial soil water content in the potential
subsurface runoff formation
Full Text in PDF 228 DOWNLOADS
- Stony soils are composed of fractions (rock fragments and fine soil) with different hydrophysical
characteristics. Although they are abundant in many catchments, their properties are still not well understood. This article
presents basic characteristics (texture, stoniness, saturated hydraulic conductivity, and soil water retention) of stony soils
from a mountain catchment located in the highest part of the Carpathian Mountains and summarizes results of water flow
modeling through a hypothetical stony soil profile. Numerical simulations indicate the highest vertical outflow from the
bottom of the profile in soils without rock fragments under ponding infiltration condition. Simulation of a more realistic
case in a mountain catchment, i.e. infiltration of intensive rainfall, shows that when rainfall intensity is lower than the
saturated hydraulic conductivity of the stony soil, the highest outflow is predicted in a soil with the highest stoniness and
high initial water content of soil matrix. Relatively low available retention capacity in a stony soil profile and
consequently higher unsaturated hydraulic conductivity leads to faster movement of the infiltration front during rainfall.
KEY WORDS: Stony soils; Infiltration; Stoniness; Initial soil water content; Mathematical modeling.
Address:
- Hana Hlaváčiková, Institute of Hydrology, Slovak Academy of Sciences, Račianska 75, 83102 Bratislava, Slovakia. (Corresponding author. Tel.: Fax.: Email: hlavacikova@uh.savba.sk)
- Viliam Novák, Institute of Hydrology, Slovak Academy of Sciences, Račianska 75, 83102 Bratislava, Slovakia.
- Ladislav Holko, Institute of Hydrology, Slovak Academy of Sciences, Račianska 75, 83102 Bratislava, Slovakia.
J. Hydrol. Hydromech., Vol. 63, No. 1, 2015, p. 82 - 92, doi: 10.1515/johh-2015-0004
Scientific Paper, English
Martin Wegehenkel, Horst H. Gerke: Water table effects on measured and simulated fluxes in weighing lysimeters
for differently-textured soils
Full Text in PDF 69 DOWNLOADS
- Weighing lysimeters can be used for studying the soil water balance and to analyse evapotranspiration (ET).
However, not clear was the impact of the bottom boundary condition on lysimeter results and soil water movement. The
objective was to analyse bottom boundary effects on the soil water balance. This analysis was carried out for lysimeters
filled with fine- and coarse-textured soil monoliths by comparing simulated and measured data for lysimeters with a
higher and a lower water table. The eight weighable lysimeters had a 1 m2 grass-covered surface and a depth of 1.5 m.
The lysimeters contained four intact monoliths extracted from a sandy soil and four from a soil with a silty-clay texture.
For two lysimeters of each soil, constant water tables were imposed at 135 cm and 210 cm depths. Evapotranspiration,
change in soil water storage, and groundwater recharge were simulated for a 3-year period (1996 to 1998) using the
Hydrus-1D software. Input data consisted of measured weather data and crop model-based simulated evaporation and
transpiration. Snow cover and heat transport were simulated based on measured soil temperatures. Soil hydraulic
parameter sets were estimated (i) from soil core data and (ii) based on texture data using ROSETTA pedotransfer
approach. Simulated and measured outflow rates from the sandy soil matched for both parameter sets. For the sand
lysimeters with the higher water table, only fast peak flow events observed on May 4, 1996 were not simulated
adequately mainly because of differences between simulated and measured soil water storage caused by ET-induced soil
water storage depletion. For the silty-clay soil, the simulations using the soil hydraulic parameters from retention data (i)
were matching the lysimeter data except for the observed peak flows on May, 4, 1996, which here probably resulted
from preferential flow. The higher water table at the lysimeter bottom resulted in higher drainage in comparison with the
lysimeters with the lower water table. This increase was smaller for the finer-textured soil as compared to the coarser
soil.
KEY WORDS: Weighable lysimeters; Modelling; Hydrus-1D; Drainage; Boundary condition.
Address:
- Martin Wegehenkel, Institute of Landscape Systems Analysis, Leibniz-Centre for Agricultural Landscape Research (ZALF) Müncheberg, Eberswalder Strasse
84, D-15374 Müncheberg, Germany. (Corresponding author. Tel.:+49 33432 / 82275 Fax.: +49 33432 / 82334 Email: mwegehenkel@zalf.de)
- Horst H. Gerke, Institute of Soil Landscape Research, Leibniz-Centre for Agricultural Landscape Research (ZALF) Müncheberg, Germany.