Ice jam characteristics, Liard–Mackenzie rivers confluence

1986 ◽  
Vol 13 (6) ◽  
pp. 653-665 ◽  
Author(s):  
Terry D. Prowse
Keyword(s):  
Internal Friction ◽  
River Mouth ◽  
Open Water ◽  
Mean Value ◽  
Water Levels ◽  
Ice Jams ◽  
Simplified Approach ◽  
Ice Breakup ◽  
Water Conditions ◽  
Rating Curves

Breakup of the Liard and Mackenzie rivers near Fort Simpson, N.W.T., was monitored from 1978 to 1984. In each year, ice jams ranging in length from 10 to 22 km formed at the Liard River mouth. Although the thickness of some of the jams exceeded 5 m, the volume of ice within the accumulations represented less than 20% of the ice contained within the pre-breakup ice cover of the Liard River main stem. The composition and thickness of the ice jams was related to whether breakup was a 'thermal' or 'mechanical' event. The majority were mechanical breakups and produced much thicker jams and higher water levels than did thermal breakups.Stage–discharge rating curves were developed for the site using two appoaches based on the equilibrium jam theory. The first employed jam parameters calculated for the 1983 jam and the second used a simplified approach suggested by S. Beltaos. Both approaches predicted stage increases of approximately 4–8 m above that which would result from similar discharge under open water conditions. Furthermore, the first approach resulted in a coefficient of internal friction of 1.06, supporting the suggestion that this parameter may have a mean value of 1.2. Key words: floating ice, floods, ice jams, ice breakup.

Analysis of breakup and ice jams on the Athabasca River at Fort McMurray, Alberta

1984 ◽  
Vol 11 (3) ◽  
pp. 444-458 ◽  
Author(s):  
D. D. Andres ◽  
P. F. Doyle
Keyword(s):  
Internal Friction ◽  
Open Water ◽  
Water Levels ◽  
Roughness Coefficient ◽  
Produce Water ◽  
Ice Jams ◽  
Athabasca River ◽  
Fort Mcmurray ◽  
Ice Jam ◽  
Clearwater River

During breakup, severe ice jams form at Fort McMurray, Alberta because of the dramatic change in the character of the Athabasca River at that location. Such jams, which produce water levels in the order of 10 m above the normal open water stage, were documented in 1977, 1978, and 1979. Additional channel surveys and improved estimates of discharge made since the initial analysis have redefined the ice jam characteristics. The Manning roughness coefficient of the underside of the ice jams was found to be 0.072. The new discharge estimates, which were up to twice those previously reported, result in a calculated coefficient of internal friction of 0.8–2.7. This is 30–100% greater than previous estimates, but still similar to values determined for ice jams at other locations.Even with the variation in the coefficient of internal friction, the river stage due to an ice jam at Fort McMurray could be computed with reasonable accuracy for a range of given discharges. If jams form downstream of the mouth of the Clearwater River at discharges greater than 800 m3/s (considerably less than the 1-in-2-year open water flood), flooding will occur within lower Fort McMurray. Unfortunately, the frequency of such an event is unknown because the probabilities of both the discharge being exceeded and the jam occurrence cannot be defined. Key words: ice, breakup, ice jam, ice roughness, flooding, hydraulics.

Ice jam mitigation

1990 ◽  
Vol 17 (5) ◽  
pp. 675-685 ◽  
Author(s):  
Harold S. Belore ◽  
Brian C. Burrell ◽  
Spyros Beltaos
Keyword(s):  
Key Words ◽  
Carrying Capacity ◽  
Flood Control ◽  
Human Life ◽  
Water Levels ◽  
Economic Losses ◽  
River Ice ◽  
Ice Jams ◽  
Ice Jam ◽  
Ice Breakup

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.

Surges from ice jam releases: a case study

1982 ◽  
Vol 9 (2) ◽  
pp. 276-284 ◽  
Author(s):  
S. Beltaos ◽  
B. G. Krishnappan
Keyword(s):  
Water Flow ◽  
Water Levels ◽  
Ice Jams ◽  
One Dimensional ◽  
Ice Jam ◽  
Ice Breakup ◽  
The Reformation ◽  
Maximum Water ◽  
Ice Water

Accounts by witnesses of spring ice breakup in rivers often mention violent ice runs with extreme water speeds and rapidly rising water levels. Such events are believed to follow the release of major ice jams. To gain preliminary understanding of this problem, an attempt is made to reconstruct a partially documented ice jam release reported recently by others. The equations of the ice–water flow that occurs after the release of an ice jam are formulated. It is shown that the problem may be approximately treated as a one-dimensional, unsteady, water-only flow of total depth identical to that of the ice–water flow, and average velocity. The retarding effect of the frequently encountered intact ice cover below the jam is considered implicitly, that is, by adjusting the friction factor so as to make the predicted and observed downstream stages equal. The effects of jam length are considered next by assuming longer jams of the same maximum water depth. The duration of the surging velocities increases with jam length and so does the peak stage. Less than 2 h after the jam release the surge was arrested and a new jam formed, causing further stage increases. Present capabilities of modelling the reformation process are discussed and the major unknowns identified.

Dynamic Ice Breakup Control for the Connecticut River near Windsor, Vermont

1988 ◽  
Vol 19 (4) ◽  
pp. 245-258
Author(s):  
M. G. Ferrick ◽  
G. E. Lemieux ◽  
P. B. Weyrick ◽  
W. Demont
Keyword(s):  
United States ◽  
Open Water ◽  
The United States ◽  
River Regulation ◽  
Flood Damage ◽  
Water Levels ◽  
Connecticut River ◽  
Ice Breakup ◽  
Lower Stage ◽  
Ice Conditions

The Cornish-Windsor bridge is the longest covered bridge in the United States and has significant historical value. Dynamic ice breakup of the Connecticut River can threaten the bridge and cause flood damage in Windsor, Vermont. We monitored ice conditions throughout the 1985-86 winter, observed a mid­winter dynamic ice breakup, conducted controlled release tests during both open water and ice cover conditions, and analyzed more than 60 years of temperature and discharge records. River regulation presents alternatives for ice mangement that would minimize water levels during breakup. In this paper we develop the basis of a method to produce a controlled ice breakup at lower stage and discharge than occur during major natural events.

Review of prediction methods for breakup ice jams

2003 ◽  
Vol 30 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Kathleen D White
Keyword(s):  
Open Water ◽  
Flood Damage ◽  
Water Levels ◽  
Water Flooding ◽  
Prediction Methods ◽  
Deterministic Models ◽  
Flood Prediction ◽  
Ice Jams ◽  
Ice Jam ◽  
Flood Warning

Breakup ice jams often occur suddenly, with little warning. Severe flooding or ice-related damage can result from rapid rises in upstream water levels associated with breakup ice jams. Breakup jam prediction methods that can be used to increase response time are desirable to minimize flood damage, including potential loss of life. A variety of hydrologic and hydraulic models exist to predict open-water flooding, whether resulting from rainfall, snowmelt, or catastrophic events such as dam breaches. However, breakup ice jams result from a complex series of physical processes that cannot currently be described with analytical or deterministic models, hindering the development of prediction methods. Those which do exist are highly site specific and range from simple empirical models to an artificial intelligence formulation. To date, no one model exhibits a clear advantage over the others. This paper provides examples of existing breakup ice jam prediction methods and discusses their potential advantages and disadvantages.Key words: ice jam, breakup ice jam, flood prediction, flood warning, ice jam mitigation.

Flow conveyance with ice cover for the Nashwaak River, N.B.

1982 ◽  
Vol 9 (4) ◽  
pp. 674-677
Author(s):  
B. Burrell ◽  
K. S. Davar
Keyword(s):  
Cross Sections ◽  
Water Surface ◽  
Open Water ◽  
Ice Cover ◽  
Cross Sectional Area ◽  
Water Levels ◽  
Flow Section ◽  
Sectional Area ◽  
Cross Sectional ◽  
Water Conditions

Measurements were undertaken along a 460-m long portion of the Nashwaak River, N.B., in order to study the flow conveyance characteristics of a regional watercourse during ice-cover and open-water conditions. Elevations of the water surface under both conditions were obtained at five cross sections for varying water levels and discharges. Various difficulties experienced in defining the cross-sectional area of the flow section, determining the influence of slush and anchor ice on the slope, and the roughness characteristics of the undersurface of the ice cover are described in order to provide a perspective on some commonly encountered problems.

scholarly journals The effect of time discretization on the propeller hydrodynamic performance simulation in self-propulsion and open water conditions

2021 ◽  
Vol 1834 (1) ◽  
pp. 012008
Author(s):  
Yang Fan ◽  
Chen Kunpeng ◽  
Chen Weimin ◽  
Dong Guoxiang
Keyword(s):  
Open Water ◽  
Time Discretization ◽  
Hydrodynamic Performance ◽  
Performance Simulation ◽  
Water Conditions

Performance of Light Coastal Structures Under Normal and High Water Conditions

1975 ◽  
Vol 2 (4) ◽  
pp. 381-391 ◽  
Author(s):  
J. W. Kamphuis
Keyword(s):  
Lake Erie ◽  
High Water ◽  
Water Levels ◽  
Coastal Protection ◽  
Coastal Structures ◽  
Water Conditions ◽  
Protection Structures

A number of lightweight coastal protection structures, built on the Lake Erie shore are discussed in this paper. There were two constraints on the design; limited funds and a very precarious downdrift beach. Thus the structures were inexpensive and the protection was low-key to prevent damage downdrift. In 1972–1974 these structures were subjected to a combination of large waves and high water levels and thus they were tested well beyond their design limits.The paper discusses the structures, their performance under normal conditions, and their performance during and after the abnormally high water levels. It is found that inexpensive, low-key structures are sufficiently strong to survive normal conditions, but fail by overtopping and flanking under conditions beyond their low design limits.

scholarly journals Model Predictive Control of a River Reach with Weirs

10.29007/1nnf ◽  
2018 ◽  
Author(s):  
Klaudia Horváth ◽  
Bart van Esch ◽  
Jorn Baayen ◽  
Ivo Pothof ◽  
Jan Talsma ◽  
...  
Keyword(s):  
Decision Support ◽  
Convex Optimization ◽  
Decision Support System ◽  
Model Predictive Control ◽  
Predictive Control ◽  
Support System ◽  
Water System ◽  
Open Water ◽  
Global Optimum ◽  
Water Levels

A decision support system for water management based on convex optimization, RTC-Tools 2, is applied for a water system containing river branches connected by weirs. The advantage of convex optimization is the ability of finding the global optimum, which makes the decision support system robust and deterministic. In this work the convex modeling of open water channels and weirs is presented. The decision support system is implemented for a river made of 12 river reaches divided by movable weirs. It is shown how the discharge wave is dispatched in the river without the water levels exceeding the bounds by controlling the weir heights. After this test the optimization can be applied to a realistic numerical model and model predictive control can be implemented.

scholarly journals Regulation of Vegetation and Evapotranspiration by Water Level Fluctuation in Shallow Lakes

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2651
Author(s):  
Qiang Liu ◽  
Liqiao Liang ◽  
Xiaomin Yuan ◽  
Sirui Yan ◽  
Miao Li ◽  
...  
Keyword(s):  
Water Level ◽  
Open Water ◽  
Water Area ◽  
Water Level Fluctuation ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Water Evaporation ◽  
Level Fluctuation ◽  
Open Water Area ◽  
Annual Scale

Water level fluctuations play a critical role in regulating vegetation distribution, composition, cover and richness, which ultimately affect evapotranspiration. In this study, we first explore water level fluctuations and associated impacts on vegetation, after which we assess evapotranspiration (ET) under different water levels. The normalized difference vegetation index (NDVI) was used to estimate the fractional vegetation cover (Fv), while topography- and vegetation-based surface-energy partitioning algorithms (TVET model) and potential evaporation (Ev) were used to calculate ET and water evaporation (Ep). Results show that: (1) water levels were dramatically affected by the combined effect of ecological water transfer and climate change and exhibited significant decreasing trends with a slope of −0.011 m a−2; and (2) as predicted, there was a correlation between water level fluctuation at an annual scale with Phragmites australis (P. australis) cover and open-water area. Water levels also had a controlling effect on Fv values, an increase in annual water levels first increasing and then decreasing Fv. However, a negative correlation was found between Fv values and water levels during initial plant growth stages. (iii) ET, which varied under different water levels at an annual scale, showed different partition into transpiration from P. australis and evaporation from open-water area and soil with alterations between vegetation and open water. All findings indicated that water level fluctuations controlled biological and ecological processes, and their structural and functional characteristics. This study consequently recommends that specifically-focused ecological water regulations (e.g., duration, timing, frequency) should be enacted to maintain the integrity of wetland ecosystems for wetland restoration.

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