Heat and mass balance of an ablating ice jam

1990 ◽  
Vol 17 (4) ◽  
pp. 629-635 ◽  
Author(s):  
Terry D. Prowse
Keyword(s):  
Mass Balance ◽  
Field Data ◽  
Heat Fluxes ◽  
Relative Importance ◽  
Ice Jams ◽  
Theoretical Methods ◽  
Ice Melt ◽  
Ice Jam ◽  
Ice Breakup ◽  
Atmospheric Heat

This paper reports on the heat and mass balance of an ablating ice jam at the confluence of the Liard and Mackenzie rivers in the spring of 1983. From May 6 to May 9, sufficient data were collected to determine the magnitude and relative importance of the major heat fluxes that caused thermal decay of the ice jam. The total atmospheric heat input of 1.25 × 108 MJ and the much larger contribution from hydrothermal sources of 9.80 × 109 MJ resulted in a total melt of 3.24 × 107 m3 of ice within the jam. These data in combination with previous results regarding jam dimensions permitted calculation of ice jam porosity, a variable frequently used in hydraulic studies of river ice jams although unverified by field data. The largest potential error in the calculations was related to the accuracy of water temperature measurement. Accounting for this resulted in an estimate of porosity of 0.38 ± 10% which lends credence to the commonly assumed value of 0.40. Details of the field conditions, instrumentation, theoretical methods, and results of the energy and mass balance analyses are described. Key words: floating ice, ice breakup, ice jams, ice melt, ice porisity.

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.

Analyse hydro-météorologique des débâcles de glaces de la rivière Nashwaak (Nouveau-Brunswick)

1992 ◽  
Vol 19 (2) ◽  
pp. 349-354
Author(s):  
S. Hebabi ◽  
N. El-Jabi ◽  
S. Sarraf
Keyword(s):  
New Brunswick ◽  
Key Words ◽  
Predictive Model ◽  
Dimensional Analysis ◽  
Predictive Models ◽  
Meteorological Factors ◽  
Ice Jams ◽  
Ice Jam ◽  
Ice Breakup ◽  
Meteorological Analysis

The problems associated with ice cover formation, development, and breakup are numerous. In fact, every year ice breakup and ice jams cause damage throughout Canada. In New Brunswick, ice breakup is responsible for 35% of floods and 70% of damage to bridges. This paper describes a hydro-meteorological analysis of ice breakup along the Nashwaak River in New Brunswick. Thirteen events that occur between 1969 and 1982 were studied. First, river records were used to determine a breakup initiation index. A dimensional analysis was then performed integrating the index with meteorological variables and river flows. Although there was no resemblance between variations of meteorological factors from one event to the next, the results suggest that the index formulated has potential as a tool for development of predictive models for ice breakup. Key words: ice breakup, ice jam, floods, meteorology, flow, predictive model, damages, bridges, Nashwaak River.

River ice breakup processes: recent advances and future directions

2007 ◽  
Vol 34 (6) ◽  
pp. 703-716 ◽  
Author(s):  
Spyros Beltaos
Keyword(s):  
Climate Change ◽  
Effective Means ◽  
Climate Change Impacts ◽  
Ice Cover ◽  
Aquatic Life ◽  
Ice Jams ◽  
Ice Jam ◽  
Ice Breakup ◽  
Extreme Flood ◽  
Mitigation Methods

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.

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.

Hydroclimatic aspects of ice jam flooding near Perth-Andover, New Brunswick

2015 ◽  
Vol 42 (9) ◽  
pp. 686-695 ◽  
Author(s):  
S. Beltaos ◽  
B.C. Burrell
Keyword(s):  
New Brunswick ◽  
Field Data ◽  
Cross Sectional ◽  
Ice Jams ◽  
Area Model ◽  
Ice Jam ◽  
Saint John ◽  
Flow Information ◽  
The 1950S

Major ice jam floods occurred along the Saint John River at Perth-Andover, New Brunswick, in 1976, 1987, 1993, 2009, and 2012. These floods have been devastating and resulted in relocation or demolition of many buildings in affected areas of the community. The purpose of this paper is to review ice processes along the Saint John River from Grand Falls to Beechwood Dam and their relevance to the ice-related problems that have occurred in Perth-Andover. The HEC-RAS program was chosen for ice jam flood stage computations, and cross-sectional, roughness and flow information entered to create a model of the study reach. The model was calibrated using field data obtained on 31 March 2000 along an ice jam in the Perth-Andover area. Model applications resulted in stage-discharge relationships for ice jams of different lengths and locations within the study stretch (Beechwood Dam to Grand Falls). These relationships indicate that ice jams can cause flooding at Perth-Andover, even with moderate spring breakup flows. The variation of ice jamming potential along the study stretch, and its relation to reservoir bathymetry and slope, are discussed. The increase in the number and severity of ice jam floods that have affected Perth-Andover may have resulted from changes in infrastructure and climate that have occurred since the 1950s. Local ice problems are likely to be aggravated over the next few decades but tempered in the longer term if the climate continues to change according to current projections.

Numerical computation of river ice jams

1993 ◽  
Vol 20 (1) ◽  
pp. 88-99 ◽  
Author(s):  
S. Beltaos
Keyword(s):  
Numerical Model ◽  
Field Data ◽  
Seepage Flow ◽  
Water Levels ◽  
Full Potential ◽  
Ice Jams ◽  
Ice Jam ◽  
Natural Stream ◽  
Flow Through ◽  
Made In

A numerical model called RIVJAM has been developed to compute the configuration of and water levels caused by ice jams of the "wide" kind, under natural stream conditions and regardless of whether the jam has attained its full potential, known as equilibrium. Account of seepage flow through the voids of the jam enables predictions of grounding conditions to be made, in accord with observations. The model is applied to three case studies of ice jam events and found to perform satisfactorily. The various model coefficients fall within the expected ranges, with the exception of a parameter characterizing the intensity of seepage flow. More field data are needed to elucidate this matter. Key words: grounding, ice, jam, model, numerical, river, seepage, thickness, toe, wide.

scholarly journals River predisposition to ice jams: a simplified geospatial model

2017 ◽  
Vol 17 (7) ◽  
pp. 1033-1045 ◽  
Author(s):  
Stéphane De Munck ◽  
Yves Gauthier ◽  
Monique Bernier ◽  
Karem Chokmani ◽  
Serge Légaré
Keyword(s):  
False Negative ◽  
Channel Morphology ◽  
River Channel ◽  
Geospatial Data ◽  
River Ice ◽  
Main Question ◽  
Ice Jams ◽  
Ice Jam ◽  
Ice Breakup ◽  
Broken Ice

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.

Thermal budget of river ice covers during breakup

1989 ◽  
Vol 16 (1) ◽  
pp. 62-71 ◽  
Author(s):  
T. D. Prowse ◽  
P. Marsh
Keyword(s):  
Heat Input ◽  
Leading Edge ◽  
Field Measurements ◽  
Open Water ◽  
Heat Fluxes ◽  
River Ice ◽  
Ice Jams ◽  
Frazil Ice ◽  
Ice Melt ◽  
Ice Roughness

The magnitude and relative importance of atmosheric (air–ice) and hydrothermal (water–ice) heat fluxes to intact and fragmented river ice covers are studied for the case of a thermal breakup. Based on field measurements obtained from the Liard River, the atmospheric sources are shown to be dominant during the period of intact ice cover. Radiation was the primary heat source, but its effect was reduced by a granulation of the decaying columnar ice which increased the cover albedo to that comparable for melting snow. The hydrothermal heat input, even with frazil ice entrained within the flow, was comparable to that from atmospheric sources under low melt conditions. The hydrothermal heat flux dramatically increased with the arrival of the breakup front because of a rapid rise in water temperature and an increase in subsurface ice roughness. Higher surface roughness and lower albedo of the fragmented ice also increased the atmospheric heat fluxes, but these were small relative to the hydrothermal heat input near the leading edge of open water. Key words: floating ice, ice breakup, ice jams, ice melt.

Dépistage des embâcles de glace par analyse hydrométrique

1990 ◽  
Vol 17 (3) ◽  
pp. 395-403
Author(s):  
N. El-Jabi ◽  
S. Sarraf
Keyword(s):  
New Brunswick ◽  
Key Words ◽  
Water Level ◽  
Power Plants ◽  
Hydroelectric Power ◽  
Spring Flood ◽  
Ice Jams ◽  
Ice Jam ◽  
Ice Breakup ◽  
Hydroelectric Power Plants

Ice jams amplify flooding problems in northern countries such as Canada. During spring flood, ice jams are often the cause of severe damages and affect considerably the production of hydroelectric power plants. This study presents a brief description of ice jams and the various types of analysis associated with this phenomenon. The effect of ice jams on the water level of 21 hydrometric stations in New Brunswick is investigated. Key words: ice jam, ice breakup, hydrometric analysis, New Brunswick, influenced level. [Journal translation]

scholarly journals Numerical prediction of ice-jam profiles in lower Athabasca River

2019 ◽  
Vol 46 (8) ◽  
pp. 722-731
Author(s):  
Spyros Beltaos
Keyword(s):  
Data Sets ◽  
Ice Jams ◽  
Athabasca River ◽  
Fort Mcmurray ◽  
Ice Jam ◽  
Ice Breakup ◽  
Sediment Loads ◽  
User Friendly ◽  
Water Level Measurements ◽  
The City

A recent study of dynamic ice breakup processes and their erosional potential in the Lower Athabasca River concluded that breakup can result in very large sediment loads, which cannot be predicted at present. As a first step towards building suitable modelling capability, a user-friendly, public-domain, ice jam model is calibrated and validated using 2013 and 2014 water level measurements as well as historical data sets by others. The calibrated model is shown to reliably compute the profiles of different ice jams occurring in a 60 km reach that extends both above and below Fort McMurray. The model also enabled development of an ice jam stage-flow relationship for the city of Fort McMurray, which can help assess present and future, climate-modified, flood risk.

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