Case histories of attempts to remove three small ice jams

1991 ◽  
Vol 18 (2) ◽  
pp. 331-335 ◽  
Author(s):  
P. F. Doyle
Keyword(s):  
Key Words ◽  
Small Rivers ◽  
Control Methods ◽  
Case Histories ◽  
Ice Jams ◽  
Ice Jam ◽  
Mechanical Removal ◽  
Thermal Deterioration

Blasting proved ineffective in removing one ice jam and mechanical removal by heavy equiment at three ice jam locations on small rivers had mixed results in reducing flood levels or accelerating jam removal. In all cases, diminishing discharge in conjunction with thermal deterioration of the jammed ice gradually had reduced the flooding problems at all sites prior to the earnest efforts to remove the jams. Frequently, there are environmental drawbacks to both blasting and mechanical removal techniques and other difficulties such as access and safety which can combine to make the utility of these ice jam control methods doubtful in many instances. Key words: ice jams, ice, ice jam removal, ice jam control, flooding.

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.

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]

FEATURES OF OPHTHALMIC CARE FOR PATIENTS WITH COMPLICATED CATARACTS

2020 ◽  
pp. 84-89
Author(s):  
Inna Ivanovna Lapkina
Keyword(s):  
Health Care ◽  
Surgical Treatment ◽  
Postoperative Complications ◽  
Key Words ◽  
Outpatient Treatment ◽  
Practical Application ◽  
Unified Approach ◽  
Case Histories ◽  
High Prevalence

Today, around 50 million people worldwide suffer from cataracts, more than a half of them need surgical treatment. High prevalence of this pathology in Ukraine, the need to improve the provision of ophthalmic care to patients, and the reform of the health care system have made the research relevant. Concomitant diseases and special conditions of the eye increase the risk of intra− and postoperative complications, worsen the functional parameters of patients after surgery. In order to develop a unified approach to the treatment of complicated cataracts based on diagnostically related groups of patients, a retrospective analysis of case histories of patients with different variants of complications related to the condition of the lens itself, its ligament apparatus and other structures of the eye was conducted. In each case, the surgeon has to choose the appropriate modification of cataract phacoemulsification surgery. The study proposed the classification of cataract phacoemulsification modifications on the basis of the techniques and the sequence of operation stages, taking into account the classification of the degrees of turbidity of the lens, proposed by L. Buratto. It has been noted that in complicated cases, according to the indications of the patient, surgery may be performed on several modifications of cataract phacoemulsification. The developed classification made it possible to generalize the various variants of pathology and greatly facilitate the choice of tactics of surgical treatment in complicated cataracts. It can be used not only for practical application, but also for improving the qualification of trained professionals. The prospect of further research is to identify contraindications for outpatient treatment of the patients with complicated cataracts. Key words: cataract complication, classification of phacoemulsification modifications, diagnostically related groups.

scholarly journals Present-day Specific Features of the Channel Morphology and Ice-jam Formation at the Tom’ River

2012 ◽  
pp. 21-33
Author(s):  
Keyword(s):  
Scientific Information ◽  
Channel Morphology ◽  
Hydrological Processes ◽  
Negative Consequences ◽  
Channel Deformations ◽  
Ice Jams ◽  
Ice Jam ◽  
Engineering Measures ◽  
Tomsk Region

Features of present-day channel deformations of the Tom' River within the Tomsk region and related processes of the ice jams’ formation have been considered. Recommendations about prevention of their negative consequences have been offered. They include organizational, scientific/information and engineering measures of the damages prevention against dangerous hydrological processes under consideration.

scholarly journals Convolutional Neural Network and Long Short-Term Memory Models for Ice-Jam Prediction

2021 ◽  
Author(s):  
Fatemehalsadat Madaeni ◽  
Karem Chokmani ◽  
Rachid Lhissou ◽  
Saeid Homayuni ◽  
Yves Gauthier ◽  
...  
Keyword(s):  
Time Series ◽  
Short Term Memory ◽  
Weather Forecasting ◽  
Multivariate Time Series ◽  
Water Levels ◽  
Time Series Classification ◽  
Ice Jams ◽  
Ice Jam ◽  
Learning Techniques ◽  
Long Short Term Memory

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.

scholarly journals Ice jam flood risks on the rivers of the Baikal Basin

2020 ◽  
Vol 163 ◽  
pp. 02001
Author(s):  
Tatyana Borisova
Keyword(s):  
Negative Impact ◽  
Flood Hazard ◽  
Hazard Analysis ◽  
Lake Basin ◽  
Baikal Lake ◽  
Ice Jams ◽  
Damage Area ◽  
Selenga River ◽  
Ice Jam ◽  
Rational Development

The article presents the results of analysis and assessment of risks related to ice jams on the rivers of the Baikal Lake Basin. It also proposes the recommendations for mitigation and rational development of coastal areas. Data on catastrophic ice jam floods for more than 100 years is presented, the factors of their formation and mechanism of their movement are considered. On the basis of official statistics from expedition surveys, potentially dangerous jamming areas have been identified, and the repeatability and extent of floods have been calculated. With the help of ArcGIS package the scale of possible flooding was determined, which allowed to reveal the list of economic objects within the damage area. Specific indicators have been used to calculate the expected damage to territories, facilities and population from the flood hazard. Analysis and assessment of economic risk from the floods on the Selenga River are given. Measures to minimize risks of negative impact of floods are proposed.

Small-scale experiments on ice-jam initiation in a curved channel

1994 ◽  
Vol 21 (5) ◽  
pp. 719-727 ◽  
Author(s):  
Gilberto E. Urroz ◽  
Robert Ettema
Keyword(s):  
Froude Number ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Small Scale ◽  
Curved Channel ◽  
Point Bar ◽  
Ice Jams ◽  
Ice Jam ◽  
Point Bars ◽  
River Bends

Two principal ice-jam initiation mechanisms, namely, lodgement and gorging, were identified through ice conveyance experiments in a small-scale, curved flume of rectangular cross section. Polyethylene blocks and beads were used to simulate ice fragments. Lodgement occurred for ice fragments that were large relative to channel width, while gorging took place when ice pieces were relatively small and were transported through the channel in multilayer. Channel roughness was found to have a significant effect in helping the arching mechanism that produces lodging. Maximum ice-floe concentration before jamming was found to increase linearly with Froude number, F, when gorging was dominant, but showed little dependence on F for ice jams initiated by lodging. Experiments conducted with point bars placed at the bends indicated that ice jams were initiated mainly by beaching of floes on the point bar. Maximum ice-floe concentration also increased linearly with Froude number for the point-bar experiments. Key words: ice-covered rivers, river bends.

Flow through the voids of breakup ice jams

1999 ◽  
Vol 26 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Spyros Beltaos
Keyword(s):  
Numerical Modelling ◽  
River Discharge ◽  
Integral Method ◽  
Laboratory Tests ◽  
Major Portion ◽  
Ice Jams ◽  
Ice Jam ◽  
Flow Through

Flow through the voids of breakup ice jams can be a major portion of the total river discharge, especially where the jam is so thick as to be grounded. Very little information is available on this question; it is derived from laboratory tests or from numerical modelling applications, and there is a discrepancy between respective seepage coefficients. A field program has been carried out to measure the flow through the voids in ice jams by taking advantage of favourable access conditions created by an ice-retention structure on the Credit River. The data obtained during two breakup events are described and an integral method of analysis is developed to identify areas of grounding and determine seepage coefficients. Values of the latter are in agreement with those deduced by numerical modelling.Key words: flow, ice jam, modelling, seepage, voids.

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