Longitudinal floating structures – new concepts in river ice control

1991 ◽  
Vol 18 (6) ◽  
pp. 933-939 ◽  
Author(s):  
Darryl J. Calkins

Ice control structures placed in the streamwise direction of a river were analyzed to determine the effectiveness in reducing ice jam thicknesses. The theory describing the thickness for “wide” river ice jams was modified to analyze these longitudinal types, providing the computational verification that ice jam thicknesses could be reduced where the mode of ice cover thickening is internal collapse. These longitudinal structures appear to provide a new tool for modifying the river ice regime at freeze-up and possibly at breakup. By decreasing the ice jam thicknesses, which leads to lower stages, the structures have the potential for decreasing ice jam flood levels. The structures' ability to function is independent of the flow velocity and these structures should perform in rivers with velocities greater than the usual limitation of roughly 1 m/s associated with conventional cross-channel ice booms. Other possible applications include controlling ice movement at outlets from lakes, enhancing river ice cover progression, or even restraining the ice cover at breakup. A U.S. patent application has been filed jointly by the author and the U.S. Army Corps of Engineers. Key words: river ice, ice jams, ice control, hydraulic structures, ice booms.

1990 ◽  
Vol 17 (5) ◽  
pp. 675-685 ◽  
Author(s):  
Harold S. Belore ◽  
Brian C. Burrell ◽  
Spyros Beltaos

In Canada, flooding due to the rise in water levels upstream of an ice jam, or the temporary exceedance of the flow and ice-carrying capacity of a channel upon release of an ice jam, has resulted in the loss of human life and extensive economic losses. Ice jam mitigation is a component of river ice management which includes all activities carried out to prevent or remove ice jams, or to reduce the damages that may result from an ice jam event. This paper presents a brief overview of measures to mitigate the damaging effects of ice jams and contains a discussion on their application to Canadian rivers. Key words: controlled ice breakup, flood control, ice jams, ice management, river ice.


2007 ◽  
Vol 34 (6) ◽  
pp. 703-716 ◽  
Author(s):  
Spyros Beltaos

The breakup of the winter ice cover is a brief but seminal event in the regime of northern rivers, and in the life cycle of river and basin ecosystems. Breakup ice jams can cause extreme flood events, with major impacts on riverside communities, aquatic life, infrastructure, navigation, and hydropower generation. Related concerns are underscored by the issue of climate change and the faster warming that is predicted for northern parts of the globe. Advances in knowledge of breakup processes and related topics, achieved over the past 15 years or so, are outlined. They pertain to breakup initiation and ice-jam formation, ice-jam properties and numerical modelling of ice jams, waves generated by ice-jam releases, forecasting and mitigation methods, sediment transport, ecological aspects, and climate-change impacts. Major knowledge gaps are associated with the dynamic interaction of moving ice with the flow and with the stationary ice cover. Increasing computing capacity and remote sensing sophistication are expected to provide effective means for bridging these gaps. Key words: climate, ecology, forecasting, ice jam, modelling, onset, sediment, wave.


2021 ◽  
Author(s):  
Apurba Das ◽  
Karl-Erich Lindenschmidt

River ice is an important hydraulic and hydrological component of many rivers in the high northern latitudes of the world. It controls the hydraulic characteristics of streamflow, affects the geomorphology of channels, and can cause flooding due to ice-jam formation during ice-cover freeze-up and breakup periods. In recent decades, climate change has considerably altered ice regimes, affecting the severity of ice-jam flooding. Although many approaches have been developed to model river ice regimes and the severity of ice jam flooding, appropriate methods that account for impacts of the future climate on ice-jam flooding have not been well established. Therefore, the main goals of this study are to review the current knowledge of climate change impacts on river ice processes and to assess the current modelling capabilities to determine the severity of ice jams under future climatic conditions. Finally, a conceptual river ice-jam modelling approach is presented for incorporating climate change impacts on ice jams.


1983 ◽  
Vol 10 (3) ◽  
pp. 538-548 ◽  
Author(s):  
Darryl J. Calkins

The equilibrium ice jam thickness given by Pariset et al. is modified to yield a clearer, consistent relationship between the flow hydraulics and thickness. The modified equations are analyzed with respect to a floating ice jam in the main channel with flow also occurring in the floodplain. The final derivation allows the expected ice jam thickness to be computed, given the bed and ice cover roughness coefficients, the channel characteristics, the water surface gradient, and the pre-breakup channel ice cover thickness. The analytical computation for the ice jam thicknesses is compared with prototype data on ice jam thicknesses from four shallow rivers which had significant floodplain flow with the ice jam event. A reasonable correlation between the predicted and measured ice jam thicknesses was obtained. The data suggests that once bankfull depth is exceeded the ice jam thickness does not increase appreciably because of flow diversion to the floodplain. Field measurements of the thickness of the remaining ice jam shear wall along with actual measurements of the ice jam thickness showed a close correlation between the two sets of data.


Author(s):  
Stéphane De Munck ◽  
Yves Gauthier ◽  
Monique Bernier ◽  
Karem Chokmani ◽  
Serge Légaré

Abstract. The goal of this work was to develop a simplified geospatial model to estimate the predisposition of any river channel to ice jams. Rather than predicting river ice break up, the main question here was to predict where the broken up ice is susceptible to jam based on the river’s geomorphological characteristics. Thus, six parameters referred to potential causes for ice jams in the literature were selected: presence of an island, narrowing of the channel, high sinuosity, presence of a bridge, confluence of rivers, and slope break. A GIS-based tool has been used to generate the aforementioned factors over regular-spaced segments along the entire channel using available geospatial data. An "Ice Jam Predisposition Index" (IJPI) was calculated by combining the weighted optimal factors. Three Canadian rivers (Province of Quebec) have been chosen as test sites. The resulting maps were assessed from historical observations and local knowledge. Results show 77 % of the observed ice jam sites on record occurred in river sections that the model considered as having high or medium predisposition. This leaves 23 % of false negative errors (missed occurrence). Between 7 % and 11 % of the highly "predisposed" river sections did not have an ice jam on record (false-positive errors). Potential improvements are discussed.


2015 ◽  
Vol 63 (4) ◽  
pp. 327-333 ◽  
Author(s):  
Jun Wang ◽  
Fayi Shi ◽  
Pangpang Chen ◽  
Peng Wu ◽  
Jueyi Sui

AbstractIce jams in northern rivers during winter period significantly change the flow conditions due to the extra boundary of the flow. Moreover, with the presence of bridge piers in the channel, the flow conditions can be further complicated. Ice cover often starts from the front of bridge piers, extending to the upstream. With the accumulation of ice cover, ice jam may happen during early spring, which results in the notorious ice jam flooding. In the present study, the concentration of flowing ice around bridge piers has been evaluated based on experiments carried out in laboratory. The critical condition for the initiation of ice cover around bridge piers has been investigated. An equation for the critical floe concentration was developed. The equation has been validated by experimental data from previous studies. The proposed model can be used for the prediction of formation of ice cover in front of a bridge pier under certain conditions.


2017 ◽  
Vol 17 (7) ◽  
pp. 1033-1045 ◽  
Author(s):  
Stéphane De Munck ◽  
Yves Gauthier ◽  
Monique Bernier ◽  
Karem Chokmani ◽  
Serge Légaré

Abstract. Floods resulting from river ice jams pose a great risk to many riverside municipalities in Canada. The location of an ice jam is mainly influenced by channel morphology. The goal of this work was therefore to develop a simplified geospatial model to estimate the predisposition of a river channel to ice jams. Rather than predicting the timing of river ice breakup, the main question here was to predict where the broken ice is susceptible to jam based on the river's geomorphological characteristics. Thus, six parameters referred to potential causes for ice jams in the literature were initially selected: presence of an island, narrowing of the channel, high sinuosity, presence of a bridge, confluence of rivers, and slope break. A GIS-based tool was used to generate the aforementioned factors over regular-spaced segments along the entire channel using available geospatial data. An ice jam predisposition index (IJPI) was calculated by combining the weighted optimal factors. Three Canadian rivers (province of Québec) were chosen as test sites. The resulting maps were assessed from historical observations and local knowledge. Results show that 77 % of the observed ice jam sites on record occurred in river sections that the model considered as having high or medium predisposition. This leaves 23 % of false negative errors (missed occurrence). Between 7 and 11 % of the highly predisposed river sections did not have an ice jam on record (false-positive cases). Results, limitations, and potential improvements are discussed.


1988 ◽  
Vol 15 (4) ◽  
pp. 609-615 ◽  
Author(s):  
P. F. Doyle

On January 4, 1984, the Nicola River and its two main tributaries broke up suddenly due to a sharp increase in discharge from a rain-on-melting-snow event while the ice cover was still thick and strong. The resulting ice run and attendant jamming caused hundreds of thousands of dollars in damage to public and private property, including the destruction of a bridge and several riprapped banks. Four ice jams remained in place for up to a week after the ice drive. All the damage was due either to the severe ice run within the channel or to flow forced out over the floodplain by ice jams. Key words: flood damage, ice run, ice breakup, ice jams, riprap.


1987 ◽  
Vol 24 (4) ◽  
pp. 784-795 ◽  
Author(s):  
Ming-ko Woo ◽  
Richard Heron

At the end of the winter, the channels of small, subarctic rivers in the coastal James Bay Lowland are filled with snow, river ice, and icing. The major processes associated with the breakup of these rivers include the melting of the snow cover and the resultant generation of meltwater, the impoundment of meltwater runoff by snow dams, the disintegration and ablation of the river ice cover, the formation and dissipation of ice jams, and an exchange of overland and channelled flow between the rivers and their adjacent wetlands. A generalization of the breakup sequences allows a qualitative prediction of the events for specific segments of the channel. Findings of this study are applicable to the many small, subarctic rivers that fringe the James Bay and Hudson Bay coasts.


Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 631
Author(s):  
Shui-Xia Zhao ◽  
Wen-Jun Wang ◽  
Xiao-Hong Shi ◽  
Sheng-Nan Zhao ◽  
Ying-Jie Wu ◽  
...  

Concern has been expressed regarding the impacts of climate change on river ice and ice jam formation in cold regions. Ice jams are easily initiated in bends and narrow channels and cause disasters. In this study, observations and remote sensing monitoring are used to study the freeze-up ice jam formation of bends. Sediment transport and freezing process of the river interact, influencing bed changes profile and sedimentary budget. River ice processes, channel evolution, ice hydro-thermodynamics, and ice jam accumulation are explored. The results show that the channel topography determines the river thalweg, and that the channel elevation interacts with the river ice through sediment transport. The channel shrinkage increases the probability of ice jam, and the sharp bend is prone to ice jam formation. Under the effect of secondary circulation flow in the bend and in the outer bank, the juxtaposed freeze-up and the hummocky ice cover occur in the same location, and frazil ice accumulates under the junction of the main channel and the shoals. Affected by the increase of the hydraulic slope and the velocity downstream, open water reaches develops downstream of the ice accumulation. An open water section is emerged upstream of the bend, due to the ice deposition, and partly cut-off supply of the frazil.


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