scholarly journals Experimental determination of the flood wave transformation and the sediment resuspension in a small regulated stream in an agricultural catchment

2017 ◽  
Author(s):  
David Zumr ◽  
Tomáš Dostál ◽  
Jan Devátý ◽  
Petr Valenta ◽  
Pavel Rosenforf ◽  
...  
Keyword(s):  
Initial Conditions ◽  
Sediment Resuspension ◽  
Wave Transformation ◽  
Flood Wave ◽  
Regulated Stream ◽  
Series Of Experiments ◽  
Water Saturated ◽  
Artificial Flood ◽  
Long Channel ◽  
Flood Waves

Abstract. This paper presents the methodology used for artificial flood experiments conducted in a small artificial, trained (regulated) channel on the Nučice experimental agricultural catchment (0.5 km2), central Czech Republic, and the results of the experiments. Two series of experiments were carried out in contrasting initial conditions: (a) in summer, when the stream banks were dry, the baseflow was negligible and the channel was fully overgrown with vegetation; and (b) in spring, when the stream banks were almost water saturated, the baseflow was above the annual average, and there was no vegetation present. Within each campaign, three successive flood waves, each with an approximate volume of 17 m3 and peak flow of ca 40 l s−1, were pumped into the upper part of the catchment drainage channel. The transformation of the flood wave and the sediment transport regime within an approximately 400 m long channel section were monitored by measuring the discharge, the turbidity and the electrical conductivity in three profiles along the stream. On the basis of the results, it was concluded that there is a considerable amount of deposited sediment in the channel that can be re-mobilized even by small floods. Part of the recorded sediment therefore originates from the particles deposited during previous soil erosion events. The flood waves initiated in dissimilar instream conditions progressed differently – we show that the saturation of the channel banks, the stream vegetation and the actual baseflow had a strong influence on the flood transformation and the sediment regime in the channel.

scholarly journals Experimental determination of the flood wave transformation and the sediment resuspension in a small regulated stream in an agricultural catchment

2017 ◽  
Vol 21 (11) ◽  
pp. 5681-5691 ◽  
Author(s):  
David Zumr ◽  
Tomáš Dostál ◽  
Jan Devátý ◽  
Petr Valenta ◽  
Pavel Rosendorf ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Initial Conditions ◽  
Sediment Resuspension ◽  
Early Spring ◽  
Wave Transformation ◽  
Flood Wave ◽  
Water Saturated ◽  
Artificial Flood ◽  
Long Channel ◽  
Flood Waves

Abstract. This paper presents the methodology used for artificial flood experiments conducted in a small artificial, trained (regulated) channel on the Nučice experimental agricultural catchment (0.5 km2), central Czech Republic, and the results of the experiments. The aim was to monitor the transformation of the flood wave and the sediment transport within the channel. Two series of experiments were carried out in contrasting initial conditions: (a) in September, when the stream banks were dry, the baseflow was negligible, and the channel was fully overgrown with vegetation; and (b) in March, when the stream banks were almost water saturated, the baseflow was above the annual average, and there was no vegetation present. Within each campaign, three successive flood waves, each with an approximate volume of 17 m3 and peak flow of ca. 40 L s−1, were pumped into the upper part of the catchment drainage channel. The transformation of the flood wave and the sediment transport regime within an approximately 400 m long channel section were monitored by measuring the discharge, the turbidity, and the electrical conductivity in three profiles along the stream. On the basis of the results, it was concluded that there is a considerable amount of deposited sediment, even in the well-trained and straight channel that can be re-mobilized by small floods. Part of the recorded sediment therefore originates from the particles deposited during previous soil erosion events. The flood waves initiated in dissimilar instream conditions progressed differently – we show that the saturation of the channel banks, the stream vegetation and the actual baseflow had a strong influence on the flood transformation and the sediment regime in the channel. The sediment moves quickly in winter and early spring, but in the later part of the year the channel serves as a sediment trap and the resuspension is slower, if dense vegetation is present.

scholarly journals Application of HEC-RAS model for estimating changes in watercourse geometry during floods

2012 ◽  
Vol 34 (2) ◽  
pp. 63-72 ◽  
Author(s):  
Joanna Markowska ◽  
Jacek Markowski ◽  
Andrzej Drabiński
Keyword(s):  
River Channel ◽  
Groundwater Table ◽  
Water Levels ◽  
Primary Role ◽  
Flood Wave ◽  
Initial State ◽  
Wave Impact ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Flood Waves

Abstract Groundwater table levels in a river valley depend, among other factors, on meteorological and hydrogeological conditions, land use and water levels in watercourses. The primary role of a watercourse is to collect surface and groundwater, and it becomes an infiltrating watercourse at high water levels. Changes in groundwater levels and the range of these changes depend chiefly on the shape, height and duration of the flood wave in the river channel. The assessment of flood wave impact on groundwater was based on long-term measurements of groundwater levels in the Odra valley and observations of water levels in the river channel. Simulations were performed with the use of in-house software FIZ (Filtracja i Zanieczyszczenia; Filtration and Contamination), designed for modelling unsteady water flows within a fully saturated zone. A two-dimensional model with two spatial variables was employed. The process of groundwater flow through a porous medium, non-homogeneous in terms of water permeability, was described with Boussinesq equation. The equation was solved with the use of finite element method. The model was applied to assess groundwater level fluctuations in the Odra valley in the context of actual flood waves on the river. Variations in groundwater table in the valley were analysed in relation to selected actual flood water levels in the Odra in 2001-2003 and 2010. The period from 2001 to 2003 was used to verify the model. A satisfactory agreement between the calculated and the measured values was obtained. Based on simulation calculations, it was proved that flood waves observed in 2010 caused a rise in groundwater table levels in a belt of approximately 1000 metres from the watercourses. It was calculated that at the end of hydrological year 2009/2010, the highest growths, of up to 0.80 m, were observed on piezometers located close to the Odra river channel. The passage of several flood waves on the Odra caused an increase of subsurface retention by 3.0% compared to the initial state.

scholarly journals Modeling nonlinear compressional waves in marine sediments

2009 ◽  
Vol 16 (1) ◽  
pp. 151-157 ◽  
Author(s):  
B. E. McDonald
Keyword(s):  
Marine Sediments ◽  
Plane Waves ◽  
High Stress ◽  
Nonlinear Behavior ◽  
Analytic Solutions ◽  
Compressional Waves ◽  
Series Of Experiments ◽  
Model Equations ◽  
The Time Domain ◽  
Water Saturated

Abstract. A computational model is presented which will help guide and interpret an upcoming series of experiments on nonlinear compressional waves in marine sediments. The model includes propagation physics of nonlinear acoustics augmented with granular Hertzian stress of order 3/2 in the strain rate. The model is a variant of the time domain NPE (McDonald and Kuperman, 1987) supplemented with a causal algorithm for frequency-linear attenuation. When attenuation is absent, the model equations are used to construct analytic solutions for nonlinear plane waves. The results imply that Hertzian stress causes a unique nonlinear behavior near zero stress. A fluid, in contrast, exhibits nonlinear behavior under high stress. A numerical experiment with nominal values for attenuation coefficient implies that in a water saturated Hertzian chain, the nonlinearity near zero stress may be experimentally observable.

scholarly journals Results and Future Prospects of the Hydro/dynamic Model of Flood Waves Spreading Use in the Amur River Basin

2017 ◽  
Author(s):  
Keyword(s):  
River Basin ◽  
Hydrodynamic Model ◽  
Model Verification ◽  
Wave Transformation ◽  
Amur River Basin ◽  
Flood Wave ◽  
Amur River ◽  
The Amur River ◽  
Far Eastern

A 2013 disastrous inundation occurred on the Amur River indicated the necessity of reaching new solutions for floods prevention and their negative consequences minimization. One of the possible ways is development of a method for setting the discharge hydrograph of the Bureya, Nizhne-Bureya and Zeya reservoirs, nonsynchronous with the forecasted hydrograph of the flood wave passage for flood-risky ranges of the Middle and Lower Amur on the basis of the flood wave transformation calculations. Results of the digital experiments on simulating the Amur runoff transformation with a hydrodynamic model developed by RosNIIVKh Far Eastern Branch on the basis of DHI-MIKE11 for the Middle and Lower Amur for information/analytical support of the Amur BWA activities on determination of the high-water passage regime for the reservoirs. As a result of the hydrodynamic model verification over the 2016–2017 period as a whole we obtained satisfactory estimations of the simulation quality criteria. On the basis of the simulation results analysis requirements to the boundary conditions have been formulated in addition to the determination of a range of practical tasks to be solved to adopt successfully the hydrodynamic simulation methods to the operative practice of the flood regulation in the Amur River basin including provision of the beds’ and floodplains’ morphometric and hydraulic characteristics relevance; the use of the runoff formation modern forecast hydrological models calculation data; and automation of the scenario calculations on the basis of integration with the Far Eastern Department of Hydro/meteorological Service state hydrological monitoring information system.

scholarly journals The role of flood wave superposition for the severity of large floods

2019 ◽  
Author(s):  
Björn Guse ◽  
Bruno Merz ◽  
Luzie Wietzke ◽  
Sophie Ullrich ◽  
Alberto Viglione ◽  
...  
Keyword(s):  
Flood Wave ◽  
Data Set ◽  
Discharge Data ◽  
Main River ◽  
Wave Superposition ◽  
Triple Points ◽  
Flood Peaks ◽  
The Impact ◽  
Flood Waves

Abstract. The severity of floods is shaped not only by event and catchment specific characteristics but also depends on river network configuration. At the confluence of relevant tributaries to the main river, flood event characteristics may change depending on magnitude and temporal matching of flood waves. This superposition of flood waves may potentially increase flood severity. However, this aspect is up to now not analysed for a large data set. To fill this gap, the role of flood wave superposition in determining flood severity is investigated. A novel methodological approach to analyse flood wave superposition is presented and applied to mean daily discharge data of 37 triple points from the four large river basins in Germany and Austria (Elbe, Danube, Rhine and Weser). A triple point consists of the three gauges at the tributary as well as upstream and downstream of the confluence to the main river. At the triple points, differences and similarities in flood characteristics are jointly analysed in terms of temporal matching and magnitudes of flood peaks. At many analysed confluences, the tributary peaks arrive consistently earlier than the main river peaks, but mostly high variability in the time lag is detected. No large differences in temporal matching are detected for floods of different magnitudes. In the majority of the cases, the largest floods at the downstream gauge occur not because of a perfect temporal matching of tributary and main river. In terms of spatial variability, the impact of flood wave superposition is site-specific. Characteristic patterns of flood wave superposition are detected for the flood peaks in the Danube, where peak discharge largely increases due to inflow from the alpine tributaries. Overall, we conclude that the superposition of flood waves is not the driving factor of flood peak severity in Germany, but a few confluences bear potential of strong flood magnifications in the case of temporal shift in flood waves.

scholarly journals Analysis of physical mechanisms of human body instability for the definition of hazard zones present in emergency action plans of dams. Case study: Santa Helena Dam, Bahia

RBRH ◽  
2019 ◽  
Vol 24 ◽  
Author(s):  
Luan Marcos da Silva Vieira ◽  
Andrea Sousa Fontes ◽  
André Luiz Andrade Simões
Keyword(s):  
Human Body ◽  
Buoyancy Force ◽  
Flood Wave ◽  
Hazard Management ◽  
Physical Mechanisms ◽  
Adaptive Ability ◽  
Definition Of ◽  
The Individual ◽  
Flood Waves

ABSTRACT The impacts caused by flood waves due to dam ruptures usually cause irreversible damages to the resident population, and, the loss of body equilibrium in floods contributes to aggravate this scenario. In this context, this work aimed to analyse the influence of consideration of physical mechanisms that cause instability in the human body on the definition of hazard zones. Therefore, it was developed simulation of the propagation of the flood wave due to the hypothetical rupture of Santa Helena Dam in Bahia, using the hydrodynamic model HEC-RAS. The results of flow velocities and heights were related and compared to different criteria of hazard zonings and mechanisms that cause body instability. It was verified that the consideration of instability mechanisms of the human body can contribute to hazard management, through the knowledge of areas in which different individuals may topple or slide. It was confirmed that in supercritical flow regimes is more likely for the individual to slide and that in subcritical regimes the individual will topple. Moreover, the consideration of parameters such as buoyancy force and the angle related to the human body's adaptive ability in a flooding influence on the definition of zones.

scholarly journals Possibilities of Controlling the River Outlets by Weirs on the Example of Noteć Bystra River

2020 ◽  
Vol 12 (6) ◽  
pp. 2369
Author(s):  
Joanna Wicher-Dysarz ◽  
Ewelina Szałkiewicz ◽  
Joanna Jaskuła ◽  
Tomasz Dysarz ◽  
Maksymilian Rybacki
Keyword(s):  
Flood Hazard ◽  
A Priori ◽  
Effective Control ◽  
Flood Wave ◽  
Extreme Hazards ◽  
Longitudinal Profiles ◽  
Maximum Flows ◽  
The City ◽  
Flood Waves

The possibility of effective control of selected dams in the Noteć Bystra river is analyzed. Such a control is expected to permit inundation of selected arable areas, e.g., peat grasslands, to avoid flooding of the city of Czarnków and the terrains located downstream. The chosen case study is the reach of the Noteć River between the dams Pianowka–Mikolajewo–Rosko. The analysis was made on the basis of simulations of the flow and regulation of dams in flood conditions. The flow peaks of hypothetical flood waves were designed according to the directions of the ISOK project (Informatyczny System Osłony Kraju przed nadzwyczajnymi zagrożeniami—IT System of the Country’s Protection Against Extreme Hazards) as the maximum flows over 10-years (p = 10%), 100-years (p = 1%), and 500-years (p = 0.2%). The obtained results are presented as longitudinal profiles of the water surface, maps of inundated areas and maps of inundated soils. The main conclusion is that the robust control of dams reduces the peak of flow during flood wave propagation and forces inundation of the a priori selected areas. It helps to decrease the spatial range of the flood hazard and significantly reduces risk related to floods.

scholarly journals Research of stress-strain state and stability of a rokfill dam under seismic actions

Vestnik MGSU ◽  
2015 ◽  
pp. 157-166
Author(s):  
Vyacheslav Valentinovich Orekhov
Keyword(s):  
Strain State ◽  
Initial Conditions ◽  
The Body ◽  
Cohesionless Soil ◽  
Soil Base ◽  
Stress Strain ◽  
Stress Strain State ◽  
Soil Skeleton ◽  
Water Saturated ◽  
Seismic Impacts

One of the main factors determining the safety of earth sea and river hydraulic structures erected on water-saturated grounds is the process of consolidation, manifested under the action of static and seismic loads. A feature of cohesionless soils located in the structure itself or in its base, is their potential ability to liquefaction under seismic impacts. This paper describes the method of calculating the saturated soil’s environments under seismic actions based on the numerical solution of differential equations of the theory of consolidation by finite element method. The results of the static problem solving for the phased construction of the installation are used as the initial conditions. In order to describe the deformability of soil materials mathematical model formed by the theory of plastic flow with hardening is used. The parameters of this model are determined by the results of triaxial testing of soils. As an example, we study the interaction of a sea rockfill dam with a sandy base under seismic impacts, determined by the synthetic accelerograms. The results of calculations of the stress-strain state of the two sections of the dam (shallow and deep) are presented, and assessment is made of the possibility of liquefaction of sandy soil base. It is shown that the pore pressure that occurs in water-saturated cohesionless soil base and the body of the dam under seismic impacts, unloads the soil skeleton, which leads to a decrease in local shear safety factors. And, in the less dense soil base of the shallow section of the dam, the soil skeleton is unloaded to a greater extent, which negatively affects its overall safety factor.

scholarly journals Substantiation of the Possibility to Use Dikes for Flood Regulation.

2016 ◽  
pp. 63
Author(s):  
Keyword(s):  
Network Capacity ◽  
Wave Transformation ◽  
Flood Wave ◽  
Channel Network ◽  
Flood Peak ◽  
River Floodplains ◽  
Maximal Runoff ◽  
Flood Regulation ◽  
Concurrent Simulation ◽  
Wave Passage

Effect of the flood regulation with the river floodplains was discussed, and a mechanism of the flood wave transformation with the basin channel network in the natural regime and during the floodplain banking was characterized. The possibility of dikes’ capacity use for cutting off the flood peak in extreme situations was substantiated and the relevant Chinese experience was analyzed. Theoretical basis for the channel network capacity management with pre-planned flooding of the “protected” floodplain areas was presented. The appropriated methods were developed; they included plotting of the maximal runoff calculated hydrographs, concurrent simulation of the flood wave passage and dikes capacities filling, more precise definition of parameters of the water-passing facilities in the dike body. Proposals on the designing of floodplain volumes and dikes intended for the flood runoff regulation were formulated. The Ingoda River (Transbaikal Kray) was taken as a study case. It was characterized by the flood maximal flows passage in different reaches due to the regulating impact of the bed and floodplain. Comparison of the real flood passage with the simulation results with the use of floodplain regulating capacities for this river was presented. Tentative results were the evidence of the principal possibility of the dikes capacity use in extreme conditions.

Analog Simulator of Flood Wave Transformation in Upper Vistula River System

1985 ◽  
Vol 18 (14) ◽  
pp. 99-104
Author(s):  
R. Gierasimiuk ◽  
A. Karbowski ◽  
K. Malinowski ◽  
A. Markowski
Keyword(s):  
River System ◽  
Wave Transformation ◽  
Flood Wave ◽  
Vistula River
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