Breakup Ice Jams Research Articles

Real-time prediction of river ice breakup phenomena: A jittered genetic programming model and wavelet analysis integrating remotely sensed imagery and machine learning

Forecasting the timing of breakup ice jams in rivers is crucial for early flood warning and effective management in cold regions where rising river flows can lead to significant damage. However, this task is hindered by insufficient data and the complex dynamics of river ice. These obstacles pose challenges in developing precise forecasting models. This study aimed to address the data scarcity issue by introducing innovative machine learning methods, focusing on classification and jittering (J), binary genetic programming (BGP), and wavelet transform (WT) for river ice forecasting (WT-JBGP) in the Tornio River, situated between Finland and Sweden. By considering time scales ranging from 2 to 32 days and time lags of 1 to 3 days, this method was applied to enhance the predictive capabilities of predictors. The findings reveal that certain predictors, with specific time scales and time lags, significantly influence the timing of breakup events. These include the 8-day temperature and 32-day discharge, both with a 2-day lag time, as well as the 4-day precipitation, approximation of albedo, and 16-day atmospheric pressure at ground level, all with a 1-day lag obtained from ERA5 and recorded data. Additionally, we conducted a quantitative evaluation of the effectiveness of the proposed model and contrasted its efficacy with that of BGP, WT-BGP, and advanced J-BGP techniques. The WT-JBGP model attains the highest overall classification accuracy of approximately 0.91, alongside a Heidke Skill Score exceeding 0.78, and a Positive Predictive Value surpassing 0.85, thereby demonstrating its superiority over competing methodologies. In summation, this study offers a promising approach to overcoming observed data scarcity in breakup date prediction, providing valuable insights into river ice dynamics.

A numerical model study on Grasse River ice-control structures

Ice jams in the Grasse River have caused the erosion of capping material designed to prevent the resurfacing of the bed sediment in the polychlorinated biphenyl (PCB)-contaminated area. Two in-stream ice-control structures are proposed to avoid the jam-induced erosion of the capping material. These two ice-control options are a pier-type ice-control structure and a reconstruction of a small hydropower dam upstream of the capping site. A numerical model study using the DynaRICE model is conducted to evaluate the effectiveness of the proposed design. Flow and ice conditions corresponding to the 100-year return period of ice jam events obtained from analyzing historical breakup ice jam data are used in the evaluation. The results showed that these ice-control structures could reduce the ice discharge downstream and the size of the ice jam at the capping site to prevent the erosion and scour of the PCB-contaminated bed.

Effects of climate change on river-ice processes and ice jams

ABSTRACT As the climate changes, ice characteristics and river-ice processes are altered, sometimes in unexpected ways. A warmer climate will obviously result in less ice globally, and in a general northward shift in the limits of seasonal river-ice occurrence. However, in several watersheds, the frequency of midwinter breakup events and the intensity of breakup ice jams may also change. In addition, climate change will alter other river-ice processes such as ice formation, freeze-up jams, and hanging dams. This is of concern during the design and construction of infrastructure as well as during the planning and implementation of flood-damage-reduction measures in and along rivers with seasonal ice covers. Changes in river-ice regimes will also alter the ecology of many lotic systems. The paper reviews the potential effects of a changing climate on river-ice properties and processes, and provides a discussion of future outcomes and their significance, as well as a suggested direction for future cold-regions river research.

Long lead forecasting of spring peak runoff using Mamdani-type fuzzy logic systems at Hay River, NWT

In northern riverside communities, breakup ice jam flooding is an annual threat to properties and human lives. In this study, the peak snowmelt runoff during breakup was assessed as an indicator of breakup flood severity. Due to the sparse network of hydrometeorolocial data in remote northern regions, a Mamdani-type fuzzy logic system (FLS) was developed and tested with the limited historical data. Three input variables were defined from the precipitation, air temperature and daily water level data. All of these variables are known ∼3 to 4 weeks before breakup enabling a long lead-time forecast. The process of system development is demonstrated by a case study of the Town of Hay River, NWT Canada. A series of experiments were designed to select the best system configuration, which also provided a way to conduct a sensitivity analysis for different choices in each system component. It was found that the system shows very good performance on the historical data using the qualitative error index. The results of the sensitivity analysis suggest the system performance is dependent on the choices of fuzzy logic inference operators and defuzzification method. As a long lead system, the short-term meteorological factors that would affect the system output were analyzed and the possible error range was assessed. Preliminary model validation, based on three years of testing, shows promising performance.

Hydroclimatic controls on the occurrence of break-up and ice-jam flooding in the Mackenzie Delta, NWT, Canada

Concern has been expressed regarding the impacts of climate change on freshwater aquatic ecosystems in arctic regions. Populated with lakes controlled by flooding from spring break-up ice jams, arctic deltas such as the Mackenzie Delta in northern Canada are particularly sensitive to changing ice break-up conditions and the hydroclimatic controls on break-up and ice-jam flooding. An understanding of these controls is necessary for assessing future climate change effects. This paper presents an assessment of hydroclimatic conditions controlling break-up over the period 1974–2006, with a focus on extreme flood events. Both the upstream driving force, capturing elements of the spring discharge hydrograph, and the downstream resistance force, describing the competence of the downstream ice cover, were quantified with reference to the Mackenzie River at Arctic Red River hydrometric station such that the contribution of each to the severity and timing of break-up could be explored. Results show that the severity of peak break-up stage is most influenced by upstream discharge and the balance between upstream and downstream melt, while timing is related to delta ice conditions and the rise of the spring hydrograph. The highest peak stage events require a rapid rise in discharge and high peak discharge. Minimal downstream melting degree-days and greater ice thickness are also important, although no relationship of these appears to control the level of backwater produced from broken ice and ice jamming effects. The pattern of rapid (protracted) upstream melt and lower (higher) intensity melt in the delta characterizes the highest (lowest) break-up events. For the most severe events, upstream forces are important in controlling discharge-driven events, while an altered hydrologic response occurring for ice-driven events was noted, meriting future examination. Finally, trends toward a longer prebreak-up melt interval, lower peak discharge, rate of rise in discharge, and ice thickness, and higher freeze-up stage were observed, with greater variability of these controls and break-up severity in the most recent decade.

River‐ice hydrology in a shrinking cryosphere

AbstractMany rivers of cold, and even temperate, regions of the globe are covered with ice for a part of the year. Projections of future climate indicate that the duration, composition and extent of ice coverage, however, will gradually change. This may have wide‐ranging consequences because ice is a critical component of cold‐regions hydrologic systems and strongly affects, for example, extreme floods, low winter flows, river transport, hydroelectric production, and numerous ecological and water‐quality characteristics. Following an overview of the processes characterizing the freezeup‐ice growth‐breakup sequence, the links of river ice to the hydrology of northern rivers are examined in detail. The rise in river stage that is caused by an ice cover is shown to be fundamental to ice‐related hydrologic impacts, such as floods caused by freezeup and breakup ice jams, low winter flows caused by water storage during freezeup and sharp waves generated by ice‐jam releases. Ice thickness and strength, both controlled by weather conditions, also play major roles. To date, the sensitivity of river‐ice regimes to changes in climatic conditions has only been partly evaluated. Most studies have focussed on ice phenology and indicate trends that are consistent with changes in air temperature, while a few recent studies have addressed the more complex questions of how climate change may alter ice thickness or the severity of extreme ice jams and floods. Foreseeable changes to river‐ice regimes, and associated hydrologic processes and impacts, are discussed in the light of current understanding. More frequent occurrence of mid‐winter breakup and associated jamming is a major effect that can be predicted with some confidence for regions where such events are presently rare or unknown. It is stressed that gaps in current knowledge preclude quantitative prediction of site‐specific changes to river‐ice regimes, and several recommendations for future research are presented. Copyright © 2008 Her Majesty the Queen in right of Canada. Published by John Wiley & Sons, Ltd.

River ice breakup processes: recent advances and future directions

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.

Formation of Breakup Ice Jams at Bridges

Bridges can impede the passage of river ice during the breakup event and promote formation of ice jams, with adverse socioeconomic and ecological impacts. Design for ice passage at bridges has largely been empirical and qualitative so that avoidance of ice-jam instigation is often uncertain. It is thus important to develop rational design criteria, based on a thorough understanding of the factors governing the interaction between bridges and ice. This concern is quantified by utilizing recent advances on breakup initiation and comparing driving and resisting forces when the sheet ice cover is about to be set in motion. Retention of ice sheets by in-stream piers can lead to jamming via accumulation of ice rubble that may be arriving from upriver. The resulting methodology is applied to two case studies and yields results that are in full accord with local experience. Though the present findings pertain to the obstruction created by in-stream piers, similar reasoning can be applied to constrictions that may be caused by protruding bridge abutments.

Water temperature decay under breakup ice jams

The water temperature decay under ice jams that form during the breakup of the river ice cover is evaluated using different data sets from several Canadian rivers. In all cases, the water temperature varies with downstream distance in negative exponential fashion, as indicated by a simplified, one-dimensional, formulation of heat conservation in a river. The corresponding heat transfer coefficients and derivative dimensionless quantities are very high relative to the values that would be expected by extrapolation of existing formulae for turbulent convection in rough pipes. It is suggested that these high heat transfer rates are due to two factors, both characteristic of breakup ice jams: the extreme roughness of the jam underside, and the flow through the voids of the accumulation of ice blocks that comprise the jam.

Review of prediction methods for breakup ice jams

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.

Application of neural networks to predict ice jam occurrence

Artificial neural networks show potential for modeling the behavior of complex nonlinear processes, such as those involved in the occurrence of breakup ice jams. Because breakup ice jams and related flooding occur suddenly, ice jam prediction methods are desirable to provide early warning and to allow rapid, effective ice jam mitigation. Unlike open-water flooding, however, an analytical description of all the complex physical processes involved is not available. As a result, breakup ice jam prediction models have historically been limited to classical empirical single-variable threshold-type analyses to statistical methods such as logistic regression and discriminant function analysis. A neural network is shown to improve the error rates of ice jam prediction at Oil City, PA. The neural network input vector is determined and the methods used to appropriately account for the relatively low occurrence of jams are addressed. The neural network prediction proves to be more accurate than the current method used at this site, with a false positive error rate of 5.9% and a false negative error rate of 7.4%.

Flow through the voids of breakup ice jams

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.

Flow through the voids of breakup ice jams

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.

Low-Cost Ice-Control Structure

Communities located on small, northern rivers can experience severe breakup ice jams. While flood damages may be significant locally, they are often insufficient to justify the cost of conventional flood-control structures. Environmental concerns also tend to render these structures unattractive. A new, low-cost structure appears to be well suited to control breakup ice jams on small rivers. It consists of massive sloped blocks, partially buried in riprap, placed across the river adjacent to a natural floodplain. The blocks will arrest a breakup ice run and form a stable, partially grounded ice jam. Trees or boulders on the floodplain retain ice pieces in the river channel while allowing flow to bypass the structure. Large gaps between blocks allow easy fish and canoe passage. Refrigerated hydraulic model tests indicate that the structure should perform well even during severe breakup events. A prototype built in Hardwick, Vt., has performed well during the four mild breakup events experienced to date. Its cost of $3,600/m of river width represents about an order-of-magnitude reduction compared with previous ice-control structures.

Dusting Procedures for Advance Ice-Jam Mitigation Measures

In areas where damaging spring breakup ice jams are recurring events, advance mitigation measures should be considered. One mitigation measure that might be used in advance of ice breakup is aerial dusting of the ice, which enhances the natural weakening process. Because there may be limited time in which to organize and implement advance measures for ice jams, dusting operations should be planned beforehand. This paper provides a brief overview of the physical processes involved in ice dusting and discusses important aspects of a dusting plan. Experiences from two dusting programs in Nebraska were used as the basis for developing a set of guidelines for planning dusting operations. A spreadsheet for estimating dusting costs was also developed, and is presented with actual data from a 1994 dusting operation.

Predicting Breakup Ice Jams Using Logistic Regression

Breakup ice jams form suddenly and with little warning. The lack of forewarning hinders emergency response and ice jam mitigation efforts. Present knowledge of breakup jam processes does not allow for the development of a deterministic ice jam prediction model. Probabilistically based prediction models include linear regression, discriminant function analysis, and empirical cluster-type analyses. In this paper, the use of logistic regression to predict breakup ice jam occurrence is presented, with an example application for the Platte River at North Bend, Nebraska.