Analysis of freeze-up ice jams on the Peace River near Taylor, British Columbia

1982 ◽  
Vol 9 (2) ◽  
pp. 176-188 ◽  
Author(s):  
T. Keenhan ◽  
U. S. Panu ◽  
V. C. Kartha

Since the construction of the Bennett Dam on the Peace River in British Columbia, the temperature of flow releases from G.M. Shrum Generation Station, located at the dam, has been 0.5 °C or higher during the winter months. As a result, the progression of ice cover below the dam is inhibited and a long reach of ice-free river persists throughout the winter. During February, 1979 below normal air temperatures persisted in the area and the cover progressed to a point 103 km downstream of the dam, or 19 km upstream of the Water Survey of Canada (WSC) stream gauge at Taylor. This was only the second occurrence of ice cover at the town of Taylor since 1972, when an increase in generating capacity at the G.M. Shrum Station raised maximum powerhouse releases to 1580 m3/s.A series of ice jams at the leading edge of the ice cover formed as the cover advanced, producing water levels within Taylor that approached the maximum historic summer flood levels. The ice movement, including ice cover advance and retreat, ice levels, and jam formation were monitored and documented. The data provided an opportunity to examine various river ice simulation models and assess their applicability to the Peace River.

2015 ◽  
Vol 42 (9) ◽  
pp. 645-655 ◽  
Author(s):  
Martin Jasek ◽  
Amy Pryse-Phillips

The objectives of the study were to describe the existing ice conditions in the Peace River and to predict changes as a result of the proposed Site C Clean Energy Project (the Project). The analyses of changes due to the Project were conducted using the CRISSP and PRTIGM models. Sixteen winters were simulated to provide a representative range of meteorological conditions on which to base the conclusions of the study. Potential changes are described in terms of the following ice characteristics: maximum upstream extent of ice cover; timing of ice cover formation and break-up; freeze-up and break-up water levels at the Town of Peace River; ice thickness; changes in ice conditions relevant for river ice crossings. The analyses also included predicting changes in these ice characteristics due to the combined influence of the Project and the proposed Dunvegan Hydro Project in Alberta. Two future climate scenarios were also considered.


2003 ◽  
Vol 30 (1) ◽  
pp. 11-27 ◽  
Author(s):  
Frank Weber ◽  
Dan Nixon ◽  
Jeff Hurley

The winter regime of the Peace River in northern British Columbia and Alberta is a determining factor for the operation of the British Columbia Hydro and Power Authority Williston Reservoir. Therefore, fine beam RADARSAT-1 synthetic aperture radar (SAR) satellite images were acquired in winter and spring 2000 and 2001 and analyzed for ice cover types. Video footage of the ice conditions on the Peace River was obtained from aerial ice observations that were conducted simultaneously with the image acquisitions. The analysis of the images was done (i) visually and (ii) using an unsupervised Fuzzy K-means classification. To streamline the process in an operational environment, the unsupervised ice classification was semi-automated. The unsupervised classification broke the data into seven classes, which represent the major ice cover types observed on the Peace River. The spatial distribution of ice cover types as generated by the ice classification generally coincides well with air-truth information and backscatter signatures from SAR images. The location of the boundaries between the ice types appears to be accurate, but it may not be precise. The ice maps can be used for ice monitoring, decision-making purposes, or the verification of ice models.Key words: river ice, remote sensing, RADARSAT-1, Peace River, semi-automated classification.


2017 ◽  
Vol 130 (4) ◽  
pp. 336 ◽  
Author(s):  
Eric A Parkinson ◽  
Chris J Perrin ◽  
Daniel Ramos-Espinoza ◽  
Eric B Taylor

The Coho Salmon, Oncorhynchus kisutch, is one of seven species of Pacific salmon and trout native to northeastern Pacific Ocean watersheds. The species is typically anadromous; adults reproduce in fresh water where juveniles reside for 1–2 years before seaward migration after which the majority of growth occurs in the ocean before maturation at 2–4 years old when adults return to fresh water to spawn. Here, we report maturation of Coho Salmon in two freshwater lakes on the north coast of British Columbia apparently without their being to sea. A total of 15 mature fish (11 males and four females) were collected in two lakes across two years. The mature fish were all at least 29 cm in total length and ranged in age from three to five years old. The occurrence of Coho Salmon that have matured in fresh water without first going to sea is exceedingly rare in their natural range, especially for females. Such mature Coho Salmon may represent residual and distinct breeding populations from those in adjacent streams. Alternatively, they may result from the ephemeral restriction in the opportunity to migrate seaward owing to low water levels in the spring when Coho Salmon typically migrate to sea after 1–2 years in fresh water. Regardless of their origin, the ability to mature in fresh water without seaward migration may represent important adaptive life history plasticity in response to variable environments.


2013 ◽  
Vol 9 (3) ◽  
pp. 1253-1269 ◽  
Author(s):  
M. Nolan

Abstract. Analysis of the 3.6 Ma, 318 m long sediment core from Lake El'gygytgyn suggests that the lake was covered by ice for millennia at a time for much of its history and therefore this paper uses a suite of existing, simple, empirical degree-day models of lake-ice growth and decay to place quantitative constraints on air temperatures needed to maintain a permanent ice cover on the lake. We also provide an overview of the modern climatological and physical processes that relate to lake-ice growth and decay as a basis for evaluating past climate and environmental conditions. Our modeling results indicate that modern annual mean air temperature would only have to be reduced by 3.3 °C ± 0.9 °C to initiate a multiyear ice cover and a temperature reduction of at least 5.5 °C ± 1.0 °C is likely needed to completely eliminate direct air–water exchange of oxygen, conditions that have been inferred at Lake El'gygytgyn from the analysis of sediment cores. Once formed, a temperature reduction of only 1–3 °C relative to modern may be all that is required to maintain multiyear ice. We also found that formation of multiyear ice covers requires that positive degree days are reduced by about half the modern mean, from about +608 to +322. A multiyear ice cover can persist even with summer temperatures sufficient for a two-month long thawing period, including a month above +4 °C. Thus, it is likely that many summer biological processes and some lake-water warming and mixing may still occur beneath multiyear ice-covers even if air–water exchange of oxygen is severely restricted.


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.


Blue Jay ◽  
1994 ◽  
Vol 52 (2) ◽  
Author(s):  
Norbert G. Kondla ◽  
Edward M. Pike ◽  
Felix A. H. Sperling

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.


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