scholarly journals Experimental investigation of the effect of vegetation on dam break flood waves

2020 ◽  
Vol 68 (3) ◽  
pp. 231-241
Author(s):  
Semire Oguzhan ◽  
Aysegul Ozgenc Aksoy

AbstractDams have an important role in the industrial development of countries. Irrespective of the reason for dam break, the flood can cause devastating disasters with loss of life and property especially in densely populated areas. In this study, the effects of the vegetation on the flood wave propagation in case of dam break were investigated experimentally by using the distorted physical model of Ürkmez Dam. The horizontal and vertical scales of the distorted physical model are 1/150 and 1/30, respectively. The dam break scenarios were achieved by means of a gate of rectangular and triangular shape. The results obtained from experiments performed with vegetation were compared and interpreted with those obtained from experiments at which the vegetation configuration was absent. The analysis of the experimental data showed that the presence of vegetation causes a significant decrease in water depths as the flood wave propagates to the downstream and greatly reduces its impact on the settlements. It is also revealed that dam break shape plays an important role in temporal variation of flood wave.

2010 ◽  
Vol 16 (5) ◽  
pp. 383-387 ◽  
Author(s):  
Yuefeng Sun ◽  
Denghua Zhong ◽  
Mingchao Li ◽  
Ying Li
Keyword(s):  

1976 ◽  
Vol 102 (2) ◽  
pp. 171-184
Author(s):  
John G. Sakkas ◽  
Theodor Strelkoff
Keyword(s):  

2018 ◽  
Vol 8 (12) ◽  
pp. 2456 ◽  
Author(s):  
Hui Hu ◽  
Jianfeng Zhang ◽  
Tao Li

The objective of this study was to evaluate the applicability of a flow model with different numbers of spatial dimensions in a hydraulic features solution, with parameters such a free surface profile, water depth variations, and averaged velocity evolution in a dam-break under dry and wet bed conditions with different tailwater depths. Two similar three-dimensional (3D) hydrodynamic models (Flow-3D and MIKE 3 FM) were studied in a dam-break simulation by performing a comparison with published experimental data and the one-dimensional (1D) analytical solution. The results indicate that the Flow-3D model better captures the free surface profile of wavefronts for dry and wet beds than other methods. The MIKE 3 FM model also replicated the free surface profiles well, but it underestimated them during the initial stage under wet-bed conditions. However, it provided a better approach to the measurements over time. Measured and simulated water depth variations and velocity variations demonstrate that both of the 3D models predict the dam-break flow with a reasonable estimation and a root mean square error (RMSE) lower than 0.04, while the MIKE 3 FM had a small memory footprint and the computational time of this model was 24 times faster than that of the Flow-3D. Therefore, the MIKE 3 FM model is recommended for computations involving real-life dam-break problems in large domains, leaving the Flow-3D model for fine calculations in which knowledge of the 3D flow structure is required. The 1D analytical solution was only effective for the dam-break wave propagations along the initially dry bed, and its applicability was fairly limited.


2012 ◽  
Vol 34 (2) ◽  
pp. 63-72 ◽  
Author(s):  
Joanna Markowska ◽  
Jacek Markowski ◽  
Andrzej Drabiński

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.


2018 ◽  
Vol 40 ◽  
pp. 05002
Author(s):  
Silvia Cordero ◽  
Andrea Cagninei ◽  
Davide Poggi

The aim of this work is to study the propagation of dam-break waves along a hillslope by mean of a physical model (basically i.e. a 3 x 4 m2 plane set downstream of a reservoir) build up in the Hydraulic Laboratory of the Politecnico di Torino. We want to recreate the water surface, to assess the shape of the flooded area and the arrival time of the wave front. The measurement facility is a high resolution CMOS camera. We measure the water height by linking the intensity of the pixels in the acquired images to the real water depth. Preliminary quantitative results are given for the 0°downstream-slope scenario and qualitative results are presented for the case of downstream inclined plane.


1976 ◽  
Vol 1 (15) ◽  
pp. 132 ◽  
Author(s):  
G.R. Mogridge ◽  
W.W. Jamieson

The forces and overturning moments exerted by waves on large vertical square-section caissons have been measured in the laboratory. Each model caisson extended from the bottom of a wave flume through the water surface and was oriented either with one side perpendicular to the direction of wave propagation or turned through an angle of forty-five degrees to this position. For a given orientation, each model was tested for a range of wave heights (up to the point of breaking) for various wave periods and water depths. A digital computer was used for the acquisition, processing, plotting and storage of the experimental data. In addition to the experimental work, an approximate theoretical method is presented which allows the wave loadings on a square caisson to be estimated by means of a simple desk calculation. The experimental data shows that this simple method of calculation is reasonably accurate over a wide range of wave conditions and caisson sizes.


2018 ◽  
Vol 40 ◽  
pp. 06026
Author(s):  
Antje Bornschein

Dam break wave simulation provides data for emergency management. The calculation results should be as accurate as possible. The modeler has to deal with different sources of uncertainty. The paper presents dam break calculation for three different dams in order to assess the uncertainty due to the chosen model (1D or 2D), different terrain models and different Manning's n values. The comparison of the calculation results is focused on the maximum discharge, maximum water level and flood wave arrival time.


2011 ◽  
Vol 243-249 ◽  
pp. 3877-3882
Author(s):  
Rong Yong Ma ◽  
Xiang Chen ◽  
Lei Lei Yang ◽  
Xiao Qing Zhang

In this paper,the basic situation of Guangxi luocheng Kama reservoir and the potential dangers are introduced firstly, and then,different models often used to estimate the loss of life in dam failure at home and abroad are introduced and analysed.Based on the above, a suitable model for national actual situation is chosen to predict the loss due to this reservoir dam breach,and the severity according to the calculation result of assuming Kama reservoir dam-break is assessed. Finally, the relevant departments’s measures of rescuing and evacuating downstream masses etc. at danger in 2009 are proved to be correct,necessary and timely.


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