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

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.

1986 ◽  
Vol 13 (6) ◽  
pp. 653-665 ◽  
Author(s):  
Terry D. Prowse

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.


2019 ◽  
Vol 46 (8) ◽  
pp. 722-731
Author(s):  
Spyros Beltaos

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.


2003 ◽  
Vol 30 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Kathleen D White

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.


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.


2021 ◽  
Author(s):  
Fatemehalsadat Madaeni ◽  
Karem Chokmani ◽  
Rachid Lhissou ◽  
Saeid Homayuni ◽  
Yves Gauthier ◽  
...  

Abstract. In cold regions, ice-jam events result in severe flooding due to a rapid rise in water levels upstream of the jam. These floods threaten human safety and damage properties and infrastructures as the floods resulting from ice-jams are sudden. Hence, the ice-jam prediction tools can give an early warning to increase response time and minimize the possible corresponding damages. However, the ice-jam prediction has always been a challenging problem as there is no analytical method available for this purpose. Nonetheless, ice jams form when some hydro-meteorological conditions happen, a few hours to a few days before the event. The ice-jam prediction problem can be considered as a binary multivariate time-series classification. Deep learning techniques have been successfully applied for time-series classification in many fields such as finance, engineering, weather forecasting, and medicine. In this research, we successfully applied CNN, LSTM, and combined CN-LSTM networks for ice-jam prediction for all the rivers in Quebec. The results show that the CN-LSTM model yields the best results in the validation and generalization with F1 scores of 0.82 and 0.91, respectively. This demonstrates that CNN and LSTM models are complementary, and a combination of them further improves classification.


2006 ◽  
Vol 33 (9) ◽  
pp. 1227-1238 ◽  
Author(s):  
C Mahabir ◽  
F E Hicks ◽  
C Robichaud ◽  
A Robinson Fayek

Spring breakup on northern rivers can result in ice jams that present severe flood risk to adjacent communities. Such events can occur extremely rapidly, leaving little or no advanced warning to residents. Fort McMurray, Alberta, is one such community, and at present no forecasting model exists for this site. Many of the previous studies regarding ice jam flood forecasting methods, in general, cite the lack of a comprehensive database as an obstacle to statistical modelling. This paper documents the development of an extensive database containing 106 variables, and covering the period from 1972 to 2004, that was created for ice jam forecasting on the Athabasca River. Through multiple linear regression analysis, equations were developed to model the maximum water level during spring breakup. The optimal model contained a combination of hydrological and meteorological data collected from early fall until the day before river ice breakup. The number of historical years of data, rather than the scope of variables, was found to be the major limitation in verifying the results presented in this study.Key words: river ice, breakup jam, multiple linear regression.


1996 ◽  
Vol 27 (3) ◽  
pp. 185-201 ◽  
Author(s):  
Raafat G. Saadé ◽  
Semaan Sarraf

In Northern Regions, the formation of ice jams along many rivers is a common phenomena. These ice jams may occur during the freeze-up and more importantly during the spring break-up period. Ice jams in general have considerable effects on the water levels because they alter the water surface profile for stretches of tens of kilometers along the rivers. As a consequence, water levels increase significantly upstream of the ice jam and result in the flooding of towns situated along the river banks. Knowledge of the water levels within an ice jam can be used to estimate many parameters that are difficult to measure and observe. Examples of such parameters are the local and global ice jam resistance to the flow, and forces acting within an ice jam. While ice jams are notorious causes of serious problems in hydraulic engineering, very little engineering methodology exists to deal with such problems. In this paper, the results of a laboratory study aimed at investigating the development of the water surface profile along an ice jam that is lodged in place, are analyzed and presented. A rectangular flume with a horizontal bed was used for the experiments. Twelve experiments carried out under different geometrical, hydrodynamic and ice conditions, were analysed. A simulated floating ice cover was used to arrest the downstream transport of the ice floes, forming the ice jams. The experiments indicate two types of ice jams, those that are floating and others that are lodged at one or more locations along their length. The phreatic water level along a floating ice jam is up to 0.92 the ice jam thickness. This is not true when an ice jam is lodged in place. Different experiments have shown that the water surface profile along a lodged ice jam follows similar tendencies regardless of the geometry, ice floe size distribution and hydrodynamic conditions. It was found that the phreatic water level varies linearly from the trailing edge of the ice jam up to approximately 90% of its length downstream. Towards the remaining part of the jam's length the water level follows a cubic polynomial line.


2003 ◽  
Vol 30 (1) ◽  
pp. 113-127 ◽  
Author(s):  
Martin Jasek

Surges or flood waves made up of ice and water resulting from the release of ice jams can be destructive to life and property and are also one of the more complicated problems in river ice engineering. The interaction between the ice mechanics and unsteady flow leads to results that are often unpredictable with open water unsteady flow models. There are considerable differences of opinion on the degree of significance of this water–ice interaction. There have also been recent developments in two-phase unsteady flow modelling which are capable of handling these complicated situations. It is the aim of this paper to present both quantitative data and qualitative observations on ice runs and breaking fronts to provide insight to the physical processes involved as and possible sources of model calibration data.Key words: ice jam, surge, unsteady flow, ice run, ice jam release, breaking front, break-up, breakup, break-up front.


1982 ◽  
Vol 9 (2) ◽  
pp. 276-284 ◽  
Author(s):  
S. Beltaos ◽  
B. G. Krishnappan

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.


2012 ◽  
Vol 43 (4) ◽  
pp. 412-421 ◽  
Author(s):  
Emmanuel Pagneux ◽  
Árni Snorrason

Hydraulic modelling is widely used for deriving flood hazard maps featuring depth of flooding and flow velocity from discharge scenarios. Due to uncertainties about flow conditions or inaccurate terrain models, flood hazards maps obtained from hydraulic modelling may be of limited relevance and accuracy. Hydraulic modelling is particularly challenging in Arctic regions, where ice jams lead to flooding in areas that would not be subjected to inundation under open-water conditions. As numerical models of ice jam processes require information that may be difficult and expensive to collect, an alternative approach based on the photo interpretation of documented historical events is presented here. Orthophotographs and a digital elevation model at high resolution are used to support the photo interpretation process. Tested in an Icelandic watershed prone to ice jam floods, reconstructions provide locally unprecedented and robust information on the extent and depth of flooding of inundations induced by ice jams.


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