7.8 Flood Generation and Flood Waves

Author(s):  
L.J. Bracken
Keyword(s):  
1997 ◽  
Vol 28 (1) ◽  
pp. 51-64 ◽  
Author(s):  
S.K. Mishra ◽  
M.K. Jain ◽  
S.M. Seth

The flood waves are characterized within the frame-work of loop (or hysteresis) of rating curves. The National Weather Service's Dam Break Flood Forecasting Model is used to generate the flood waves in the downstream valley of the Bargi dam located in Central India. The quantified hystereses, η, of non-dimensional rating curves are related with the corresponding flood wave characteristics, viz., speed of travel, wave number, phase difference, and attenuation. The analysis has led to the development of an exact relationship between η and phase difference. Using the concept of wave zoning, the better performance of the hysteresis based criteria compared with the available criteria is verified using Convex and Muskingum-Cunge routing in the wave zones. η limits are specified for the applicability of these simplified routing models. Furthermore, the envisaged applications of the based analysis are introduced.


2009 ◽  
Vol 9 (4) ◽  
pp. 1349-1363 ◽  
Author(s):  
D. Nijssen ◽  
A. Schumann ◽  
M. Pahlow ◽  
B. Klein

Abstract. As a result of the severe floods in Europe at the turn of the millennium, the ongoing shift from safety oriented flood control towards flood risk management was accelerated. With regard to technical flood control measures it became evident that the effectiveness of flood control measures depends on many different factors, which cannot be considered with single events used as design floods for planning. The multivariate characteristics of the hydrological loads have to be considered to evaluate complex flood control measures. The effectiveness of spatially distributed flood control systems differs for varying flood events. Event-based characteristics such as the spatial distribution of precipitation, the shape and volume of the resulting flood waves or the interactions of flood waves with the technical elements, e.g. reservoirs and flood polders, result in varying efficiency of these systems. Considering these aspects a flood control system should be evaluated with a broad range of hydrological loads to get a realistic assessment of its performance under different conditions. The consideration of this variety in flood control planning design was one particular aim of this study. Hydrological loads were described by multiple criteria. A statistical characterization of these criteria is difficult, since the data base is often not sufficient to analyze the variety of possible events. Hydrological simulations were used to solve this problem. Here a deterministic-stochastic flood generator was developed and applied to produce a large quantity of flood events which can be used as scenarios of possible hydrological loads. However, these simulations imply many uncertainties. The results will be biased by the basic assumptions of the modeling tools. In flood control planning probabilities are applied to characterize uncertainties. The probabilities of the simulated flood scenarios differ from probabilities which would be derived from long time series. With regard to these known unknowns the bias of the simulations was considered by imprecise probabilities. Probabilities, derived from measured flood data were combined with probabilities which were estimated from long simulated series. To consider imprecise probabilities, fuzzy sets were used to distinguish the results between more or less possible design floods. The need for such a differentiated view on the performance of flood protection systems is demonstrated by a case study.


2017 ◽  
Vol 51 (1) ◽  
pp. 52-57 ◽  
Author(s):  
S. V. Norin ◽  
V. V. Belikov ◽  
A. I. Aleksyuk

1893 ◽  
Vol 28 (1) ◽  
pp. 199-204
Author(s):  
Arthur N. Talbot ◽  
Alva J. Grover
Keyword(s):  

2016 ◽  
Author(s):  
O Link ◽  
A Pizarro ◽  
C Castillo ◽  
B Ettmer ◽  
S Manfreda
Keyword(s):  

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

2021 ◽  
Author(s):  
Mathieu Lucas ◽  
Michel Lang ◽  
Jérôme Le Coz ◽  
Benjamin Renard ◽  
Hervé Piegay

<p>The Rhône River has undergone many anthropogenic transformations to improve his navigability and produce hydroelectricity since the mid-19th century. From the longitudinal dikes of the 1850’s to the hydroelectric diversion schemes of the 1950’s and 1960’s, these structures had a direct impact on the channel geometry along the 300km of river course between Lyon (France) and the Mediterranean Sea. An indirect consequence could be a change in the flood dynamics along the channel course, caused by the simplification of the channel patterns and the floodplain accretion. This communication aims to assess the potential changes in the flood propagation along the middle and lower Rhône valley throughout a century of anthropogenic reconfigurations of the channel. The possible impact of these human pressures on the inundation risk and the attenuation of the flood peak discharge is also discussed. Through the use of digitized hydrometric data recorded since 1840 on multiple stream gauges of the Rhône river, a variety of floods of the same type and magnitude are selected. The oceanic flood types (as described by Pardé, 1925) that take their origin from heavy rainfalls upstream of the area of interest are preferred. Thus, complex flood waves due to floods from the lower Rhône valley tributaries are avoided, to keep the analysis as simple as possible. The flood travel time and the peak discharge attenuation of the selected events are compared over the years of channel transformations, permitting us to estimate the impact of anthropogenic pressures on the flood dynamics.</p>


2022 ◽  
pp. 92-111
Author(s):  
Bhavya Kavitha Dwarapureddi ◽  
Swathi Dash ◽  
Aman Raj ◽  
Nihanth Soury Garika ◽  
Ankit Kumar ◽  
...  

Climatic conditions, precise relief features, variations of soil, flora cover, socio-economic conditions together lead to torrential flood waves as a result of current soil erosion processes. Erosion and torrential floods are aggravated due to over exploitation of agricultural and forest land along with urbanization. Effects of soil erosion include nutrient loss, land use changes, reduced productivity, siltation of water bodies, among other effects like affecting livelihood of marginal communities dependent on agriculture globally and public health. Nearly 11 million km2 of soil is impacted by erosion precisely by water. Other factors like intensified agriculture and climate change contribute to and aggravate the erosion rate. Contemporary torrential floods are characterized by their increased destruction and frequency unlike the pre-development periods when their occurrence was rare. The focus of this review is to compile and aid as a data base for understanding methods of preventing erosion of soil and torrential floods as put forth by various researchers.


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