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Vijay P Singh - One of the best experts on this subject based on the ideXlab platform.
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hysteresis based Flood Wave analysis using the concept of strain
Hydrological Processes, 2001Co-Authors: S K Mishra, Vijay P SinghAbstract:Hysteresis represents a loop in a rating curve and is a phenomenon which closely resembles that occurring in stress–strain curves used for studying the elastic properties of solid substances in engineering mechanics. Earlier hysteresis-based studies used for defining FloodWave propagation in open channels have qualitatively shown that hysteresis is an index of energy loss during FloodWave propagation. Using the concept of elasticity, this paper introduces a new term called flow strain (defined as the ratio of change in discharge to the initial discharge) for investigating hysteresis. The usefulness of this new term is evaluated with use of four dam-break studies. The study reveals that: 1 flow strain is a function of three Wave speeds, Seddon speed, Lagrange speed, and elastic speed; 2 a single linear reservoir concept frequently used in Flood routing is a specific variant of the Seddon speed formula; 3 the non-linear storage–discharge relationship, widely used in overland flow modelling, is a variant of the kinematic Wave representation; 4 the discharge ordinates on the recession part of a hydrograph follow a simple first-order autoregressive form; 5 the hysteresis, phase difference and logarithmic decrement all define attenuation and are indices of energy loss during FloodWave propagation. Copyright © 2001 John Wiley & Sons, Ltd.
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hysteresis based Flood Wave analysis
Journal of Hydrologic Engineering, 1999Co-Authors: S K Mishra, Vijay P SinghAbstract:By employing looped or hysteretic rating curves, Flood Wave propagation in natural and artificial channels is analytically described. The analytical relation between a quantitative descriptor of hysteresis η and phase difference φ is verified using numerical and observed data, and a unique relationship among η, φ, and logarithmic decrement δ is presented for kinematic Waves. Finally, the effect of channel and input Flood Wave characteristics as well as downstream boundary conditions on Flood Wave propagation is evaluated.
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kinematic Wave modeling in water resources surface water hydrology
1996Co-Authors: Vijay P SinghAbstract:Water Resources Modeling. Spatial Representation of Watersheds. HYDRAULIC PRELIMINARIES. Hydraulic Equations for Surface Flow. Linearization of Hydraulic Equations. Flow Resistance. WATER WaveS. Shallow Water Waves. Kinematic Wave Theory. Diffusion Wave Theory. Accuracy of Kinematic Wave and Diffusion Wave Theories. OVERLAND FLOW. St. Venant Equations for Flow Over A Plane. Diffusion Wave Modeling. Kinematic Wave Modeling of Overland Flow on A Plane: Analytic Solutions. Kinematic Wave Modeling of Overland Flow on an Infiltrating Plane: Analytical Solutions. Kinematic Wave Modeling of Overland Flow on a Plane: Numerical Solutions. Kinematic Wave Modeling of Overland Flow on Converging Surfaces. Kinematic Wave Modeling of Overland Flow on Diverging Surfaces. Kinematic Shock. CHANNEL FLOW ROUTING. Dynamic Wave Modeling for Channel Flow Routing. Diffusion Wave Modeling for Channel Flow Routing. Kinematic Wave Flow Routing. Dam--Break Flood--Wave Routing. Appendices. References. Index.
Michael Hartnett - One of the best experts on this subject based on the ideXlab platform.
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high resolution multi scale modelling of coastal Flooding due to tides storm surges and rivers inflows a cork city example
Coastal Engineering, 2017Co-Authors: Agnieszka Indiana Olbert, Joanne Comer, Stephen Nash, Michael HartnettAbstract:Abstract This paper demonstrates the capability of a new state-of-the-art Flood modelling system consisting of multiple nested models to simulate urban coastal Flood inundation. A Flood event in Cork City, Ireland which occurred in November 2009 is analysed in detail. The new Flood modelling system comprises of two dynamically linked models: an ocean model (POM) of the northeast Atlantic (ca. 5 km grid) and a coastal Flood model, MSN_Flood, which resolves the hydrodynamics of Cork Harbour and its sub region at four spatial scales 90 m, 30 m, 6 m and 2 m through a cascade of four nested grids. Flood water propagation through Cork City Floodplains is simulated by the 2 m grid model. The POM-MSN_Flood modelling system, presented for the first time in this paper, was used to investigate the dynamics of coastal Flooding resulting from a complex set of tides, storm surges, rivers inflows and the interactions between them. Unlike many Flood models, the modelling system used in this research provides a full description of water levels and flow regimes, both in coastal waters and urban Floodplains. Validation results clearly demonstrate that the model is capable of resolving hydrodynamics at scales commensurate with flow features including the large scale processes of the NE Atlantic Ocean and the fine resolution circulation of coastal waters. With regards to urban Flooding, the model was found to accurately determine Flood Wave propagation patterns, Flood Wave heights, speeds and inundation extents. Ultimately, the model was used to investigate mechanisms of Flooding resulting from multiple process drivers and to assess Flood risk to human safety. Such an analysis facilitates better understating of the mechanics and dynamics of complex coastal urban Flooding and would therefore be of interest in the field of coastal management.
Gokmen Tayfur - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of Flood Wave propagation in two dimensions in densely populated urban areas due to dam break
Water Resources Management, 2016Co-Authors: Ismail Haltas, Sebnem Elci, Gokmen TayfurAbstract:Dams are important structures having many functions such as water supply, Flood control, hydroelectric power and recreation. Although dam break failures are very rare events, dams can fail with little warning and the damage at the downstream of the dam due to the Flood Wave can be catastrophic. During a dam failure, immense volume of water is mobilized at very high speed in a very short time. The momentum of the Flood Wave can turn to a very destructive impact force in residential areas. Therefore, from risk point of view, understanding the consequences of a possible dam failure is critically important. This study deals with the methodology utilized for predicting the Flood Wave occurring after the dam break and analyses the propagation of the Flood Wave downstream of the dam. The methodology used in this study includes creation of bathymetric, DEM and land use maps; routing of the Flood Wave along the valley using a 1D model; and two dimensional numerical modeling of the propagation and spreading of Flood Wave for various dam breaching scenarios in two different urban areas. Such a methodology is a vital tool for decision-making process since it takes into account the spatial heterogeneity of the basin parameters to predict Flood Wave propagation downstream of the dam. Proposed methodology is applied to two dams; Porsuk Dam located in Eskisehir and Alibey Dam located in Istanbul, Turkey. Both dams are selected based on the fact that they have dense residential areas downstream and such a failure would be disastrous in both cases. Model simulations based on three different dam breaching scenarios showed that maximum flow depth can reach to 5 m at the border of the residential areas both in Eskisehir and in Istanbul with a maximum flow velocity of 5 m/s and Flood Waves having 0.3 m height reach to the boundary of the residential area within 1 to 2 h. Flooded area in Eskisehir was estimated as 127 km2, whereas in Istanbul this area was 8.4 km2 in total.
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two dimensional numerical modeling of Flood Wave propagation in an urban area due to urkmez dam break izmir turkey
Natural Hazards, 2016Co-Authors: Ismail Haltas, Gokmen Tayfur, Sebnem ElciAbstract:This study investigated Flood inundation in an urban area due to a possible failure of Urkmez Dam in Izmir, Turkey. The estimation of Flood hydrograph upon partial failure of the dam and routing of the Flood hydrograph along the narrow valley downstream were first performed by the one-dimensional hydraulic routing model HEC-RAS. The two-dimensional hydraulic routing model FLO-2D is then used to simulate the spreading of the dam-break Flood after the Flood Wave exits the valley. Land use and land cover digital maps were utilized to find the spatially varying roughness coefficient for the Floodplain. The influence of the buildings on the Flood propagation was represented in the numerical model by the area reduction factor as well as the width reduction factor. The peak flow depth, peak flow velocity and time moment of the peak flow depth maps were shown in the GIS environment. The results reveal that flow depths can reach about 3 m in the residential area. In about 40 min after the dam-break, houses in the large section of the town would be under the maximum flow depths. The two-dimensional hydrodynamic model results were tested against experimental dam-break flow data of the distorted physical model of Urkmez Dam, which is consisted of the reservoir, dam body and downstream area including Urkmez Town. The model successfully simulated experimental flow depth data measured at different measurement locations.
Agnieszka Indiana Olbert - One of the best experts on this subject based on the ideXlab platform.
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high resolution multi scale modelling of coastal Flooding due to tides storm surges and rivers inflows a cork city example
Coastal Engineering, 2017Co-Authors: Agnieszka Indiana Olbert, Joanne Comer, Stephen Nash, Michael HartnettAbstract:Abstract This paper demonstrates the capability of a new state-of-the-art Flood modelling system consisting of multiple nested models to simulate urban coastal Flood inundation. A Flood event in Cork City, Ireland which occurred in November 2009 is analysed in detail. The new Flood modelling system comprises of two dynamically linked models: an ocean model (POM) of the northeast Atlantic (ca. 5 km grid) and a coastal Flood model, MSN_Flood, which resolves the hydrodynamics of Cork Harbour and its sub region at four spatial scales 90 m, 30 m, 6 m and 2 m through a cascade of four nested grids. Flood water propagation through Cork City Floodplains is simulated by the 2 m grid model. The POM-MSN_Flood modelling system, presented for the first time in this paper, was used to investigate the dynamics of coastal Flooding resulting from a complex set of tides, storm surges, rivers inflows and the interactions between them. Unlike many Flood models, the modelling system used in this research provides a full description of water levels and flow regimes, both in coastal waters and urban Floodplains. Validation results clearly demonstrate that the model is capable of resolving hydrodynamics at scales commensurate with flow features including the large scale processes of the NE Atlantic Ocean and the fine resolution circulation of coastal waters. With regards to urban Flooding, the model was found to accurately determine Flood Wave propagation patterns, Flood Wave heights, speeds and inundation extents. Ultimately, the model was used to investigate mechanisms of Flooding resulting from multiple process drivers and to assess Flood risk to human safety. Such an analysis facilitates better understating of the mechanics and dynamics of complex coastal urban Flooding and would therefore be of interest in the field of coastal management.
S K Mishra - One of the best experts on this subject based on the ideXlab platform.
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hysteresis based Flood Wave analysis using the concept of strain
Hydrological Processes, 2001Co-Authors: S K Mishra, Vijay P SinghAbstract:Hysteresis represents a loop in a rating curve and is a phenomenon which closely resembles that occurring in stress–strain curves used for studying the elastic properties of solid substances in engineering mechanics. Earlier hysteresis-based studies used for defining FloodWave propagation in open channels have qualitatively shown that hysteresis is an index of energy loss during FloodWave propagation. Using the concept of elasticity, this paper introduces a new term called flow strain (defined as the ratio of change in discharge to the initial discharge) for investigating hysteresis. The usefulness of this new term is evaluated with use of four dam-break studies. The study reveals that: 1 flow strain is a function of three Wave speeds, Seddon speed, Lagrange speed, and elastic speed; 2 a single linear reservoir concept frequently used in Flood routing is a specific variant of the Seddon speed formula; 3 the non-linear storage–discharge relationship, widely used in overland flow modelling, is a variant of the kinematic Wave representation; 4 the discharge ordinates on the recession part of a hydrograph follow a simple first-order autoregressive form; 5 the hysteresis, phase difference and logarithmic decrement all define attenuation and are indices of energy loss during FloodWave propagation. Copyright © 2001 John Wiley & Sons, Ltd.
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hysteresis based Flood Wave analysis
Journal of Hydrologic Engineering, 1999Co-Authors: S K Mishra, Vijay P SinghAbstract:By employing looped or hysteretic rating curves, Flood Wave propagation in natural and artificial channels is analytically described. The analytical relation between a quantitative descriptor of hysteresis η and phase difference φ is verified using numerical and observed data, and a unique relationship among η, φ, and logarithmic decrement δ is presented for kinematic Waves. Finally, the effect of channel and input Flood Wave characteristics as well as downstream boundary conditions on Flood Wave propagation is evaluated.
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use of hysteresis for defining the nature of Flood Wave propagation in natural channels
Hydrological Sciences Journal-journal Des Sciences Hydrologiques, 1996Co-Authors: S K Mishra, S M SethAbstract:Abstract The hysteresis (η) of the non-dimensional site-specific rating curve is used to describe the occurrence of a kinematic Wave (KW), a diffusion Wave (DW) or a dynamic Wave (DYW) in the downstream valleys of the Teton dam, USA, and the Machhu dam II, India. Criteria are developed for the occurrence of these Waves. The study reveals that the hysteresis is the energy loss occurring at a particular site and is related to the speed of travel, Wave number, phase difference and attenuation characteristics of the Flood Wave. The role of η is shown to be of vital importance in: (i) choosing a suitable downstream boundary for improving the results; and (ii) identifying the Wave zones where approximate models can substitute the complete DYW model.