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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. [ABSTRACT FROM AUTHOR]

The Hogansburg Dam in Akwesasne, NY, on the lower St. Regis River, a tributary of the St. Lawrence River, was decommissioned and removed in 2016. The dam removal restored over 893 river km of migratory fish access. However, ice jams occurred on the lower St. Regis River in winter before and after the dam removal, which caused flooding in the St. Regis Mohawk Tribe Reservation. This study reviewed the historical ice-jam conditions in the lower St. Regis River and the effect of dam removal. A two-dimensional river-ice model, DynaRICE, capable of simulating the dynamic ice transport and jamming processes, was used to evaluate pre- and post-dam-removal conditions of the Hogansburg Dam on the ice-jam flooding in the St. Regis Mohawk Tribe Reservation. The study showed that the dam removal effect decreases as the breakup discharge increases. A potential mitigation scheme for reducing ice-jam floods in the Hogansburg area using ice booms was examined and recommended. [ABSTRACT FROM AUTHOR]

A numerical model, DEMRICE, coupling a discrete element model with a finite element shallow water hydrodynamic model, is developed to study ice cover breakup by water waves in river channels. The ice cover is modeled by bonded dilated polyhedral elements that can break when the stress between the elements exceeds a critical bond strength. The model is applied to simulate wave-ice cover interaction, transverse crack propagation, and fragmentation of the cracked ice cover in a straight rectangular channel. The influence of varying wave characteristics and ice properties, such as wave height, wavelength, wave slope, ice thickness, and ice flexure strength, on crack propagation and cover fracture is examined. The analysis showed that the cover uplifting is the main cause of the ice cover fracture. The propagation speed of the cracks along the cover is mainly influenced by the wave speed, wave characteristics, and ice properties. • Developed a bonded-fracture DEMRICE river ice model to study the river ice cover breakup and fragmentation by river waves. • Examined the influence of wave characteristics and ice properties on cover breakup crack and fracture. • Confirmed the river ice cover breakup and fracture processes observed in the field. [ABSTRACT FROM AUTHOR]

Various empirical equations for mean bed and wall shear stresses have been proposed for smooth rectangular open channels. Considering that the distribution of bed shear and wall shear stresses is affected by the cross-sectional shape, the gravity force based on the flow depth used to non-dimensionalize shear stresses in previous studies is modified to a parameter that includes the width and wetted-perimeter. This yields a new set of dimensionless equations for mean bed and wall shear stresses, and the wall/bed shear force ratio. These equations compared well with all available experimental data over a wide range of aspect ratios from 0.31 to 50. These equations also yield new relationships for bed and wall friction factors. [ABSTRACT FROM AUTHOR]

This study analyzed the wintertime surface heat exchange for the Inner Mongolia reach of the Yellow River, China, based on the data from the nearby weather station at Wulateqianqi. In this analysis, the solar radiation is based on the observed data. Other components of the surface heat flux, that is, long‐wave radiation, and evaporative and conductive heat fluxes, are calculated. The relative importance of the contributions of long‐wave radiation, conductive, and evaporative heat fluxes are in descending order. The air temperature is the most important meteorological factor to the total heat flux. Although the wind speed influences evaporative and conductive heat fluxes, it has the least correlation with the total heat budget. The heat exchange coefficient for the linearized surface heat exchange equation is 21.87 W/(m2 °C), which is comparable with published values in the regions of United States and Canada with similar latitudes. Research Impact Statement: Wintertime surface heat exchange plays an important role on water temperature and ice conditions in cold region rivers. The surface heat exchange for the Inner Mongolia region is analyzed. [ABSTRACT FROM AUTHOR]

Sediment transport and river morphology in cold regions can be significantly influenced by the presence of ice in winter. This paper presents a two-dimensional numerical model on sediment transport coupled with a river ice model. The sediment transport and bed change model is based on recently developed sediment transport formulations under the effect of ice cover. Incorporating changing surface ice dynamics allows the interaction of ice and sediment to be fully realized. Numerical examples are presented that illustrate surface ice effects on sediment transport and bed changes in alluvial channels. These examples include the effects of surface ice runs on sediment transport, sediment transport and bed change in the vicinity of an ice cover front, effect of ice cover breakup, and the interaction of ice jam formation with bed change. Simulation results showed the importance of considering ice effects when studying sediment and channel morphological processes in alluvial rivers. [ABSTRACT FROM AUTHOR]

Ice jam floods are frequent occurrences throughout the Saint John River. Spring ice breakup, due to the freshet, are the most common and damaging. A coupled two-dimensional hydro and ice dynamics model was used to study the breakup and jamming processes on the 64 km reach of the Saint John River between Grand Falls and the Beechwood Generation Station. The model simulated the evolution of the 2012 ice breakup and jamming event, which caused record high flooding. The simulated results compared well with observed data and provided detailed information on the breakup processes. The study showed that both failure due to accumulation of ice at the cover leading edge and failure due to high rates of water level change from surges were important ice breakup processes. It was also found that one of the most significant factors in the flooding at Perth–Andover was the release of ice from above Grand Falls. [ABSTRACT FROM AUTHOR]

Cross vane structures aim to reduce near-bank shear and increase center channel flow intensity to retain flood flow and maintain sediment transport capacity in stream channels. These in-stream structures have been widely applied for river management, but how they interact with the local ice regime is poorly understood. This paper presents a numerical model study of the interaction of cross vane structures with sediment and ice using a two-dimensional coupled river ice-sediment dynamic model. The model was used to simulate a variety of ice and flow conditions to show how cross vanes affect sediment and ice processes. The study showed the design of cross vane structures in cold region rivers should consider the ice effects, especially the increasing potential of ice jam formation and related bed change. [ABSTRACT FROM AUTHOR]

Abstract: River ice processes involve complex interactions between hydrodynamic, mechanical, and thermal processes. River ice research has largely been driven by engineering and environmental problems that concern society, including ice effects on flooding, hydropower, navigation, ecology, and the environment. Important findings on river ice research before 1980 have been summarized by Ashton (1986) and Donchenko (1987). Significant progress has been made in river ice research in the last three decades. Mathematical modeling has been an essential part of this progress. Mathematical models have been developed for various river ice processes. They not only helped to advance understanding of the physical processes by complementing field and laboratory studies, but also provided tools for planning and design of engineering projects. In this paper, models of various river ice processes during the winter, from freeze-up to breakup, are reviewed after a brief overview of river ice phenomena. Following the discussion of these ‘component’ models, a discussion on ‘comprehensive’ models and an analytical framework which links all river ice processes in a coherent manner is presented. [Copyright &y& Elsevier]

Reviews the state of knowledge on river ice processes, and its implications on river ice engineering. Freeze-up period; Ice-covered period; Breakup period.

A spring ice jam occurred in the Shokotsu River in March 1995. This has been the only known ice jam in this river since 1955. This paper discusses the ice jam processes and investigates the causes of the Shokotsu River ice jam by analyzing the available hydrometeorological data as well as hydraulic and geometric characteristics of the river. This analysis showed that this breakup event was triggered by a sudden increase in basin runoff produced by the rainfall during a warm spell. Snowmelt resulting from warm air temperature alone would not be sufficient to produce the discharge increase for the breakup. The jam was initiated at a section with rapid reductions in channel slope, flow velocity, as well as the top width as the ice run approached from upstream. Numerical simulation carried out to analyze the ice jam dynamics showed that the model is capable of reproducing the jam event and supplemented the limited information obtained from the field observation. [Copyright &y& Elsevier]

This paper presents a laboratory study on anchor ice evolution and its hydraulic effect in channels with a gravel bed. The study revealed that anchor ice is initiated by frazil ice accumulation on bed gravel from half a gravel diameter below the crown level of the gravel. No in-situ ice growth within the frazil accumulation or downward growth towards the bed was observed. During the initial stage of growth anchor ice grew in the forms of tails, scales, or balls, depending on the flow velocity and Froude number. During the final stage of growth, when the gravel bed was covered by ice, the growth rate increased with the heat loss rate and Froude number, and inversely proportional to the flow depth. The overall hydraulic resistance of anchor ice was smaller for smaller bed gravel sizes and decreases with the increase in flow rate and flow depth. The rate of increase of the gross Manning''s resistance coefficient decreases with the increase in Reynolds number. The bed/ice surface roughness first increases with anchor ice growth, then decreases to a minimum value after the initial stage of growth, when anchor ice grew out of the gravel bed. [Copyright &y& Elsevier]

In this study, a numerical model for river ice dynamics (DEMRICE) based on the discrete element method is developed. The ice dynamic component of this model considers moving surface ice floes as discrete elements. It uses a three-dimensional dilated polyhedral discrete element method to resolve contact and external forces on individual ice floes. The hydrodynamic component uses a streamline upwind Petrov–Galerkin (SUPG) finite-element method to solve the two-dimensional unsteady hydraulic equations. The model is validated with the analytical solution for equilibrium ice jams and the DynaRICE model. The ice jam evolution in a straight rectangular channel and the corresponding flow condition changes are simulated and discussed. Finally, the model is applied to simulate the ice transport and cover development in a reach of the Yellow River near Shisifenzi, Inner Mongolia. [ABSTRACT FROM AUTHOR]

Presents a study on fluid dynamics which analyzed the applicability of a pure Lagrangian numerical model to dam-break flows by solving the Saint Venant equations. Information on the Lagrangian method; Dam-break simulation; Comparisons with analytical and other numerical solutions.

This paper presents the formulation of a one-dimensional river-ice simulation model RICEN. The model consists of two major parts: (1) An unsteady flow model for a channel network with ice; and (2) a thermal and ice condition simulation model. The model simulates the water-temperature variation along the river, including supercooling; frazil-ice concentration distribution; anchor-ice growth, decay, and release; surface ice transport; ice-cover progression; undercover ice transport, deposition, and erosion; thermal growth and decay of ice covers; and ice-cover stability. [ABSTRACT FROM AUTHOR]

This paper presents the results of model calibration and a parametric study of the ice-jamming processes in the Tonawanda Channel of the upper Niagara River using the one-dimensional river-ice model RICEN. The model is calibrated using observations and data from historical ice-jam events. A parametric study is carried out to examine the effects of various weather and flow conditions on ice-jam formation and the ice jam's concomitant effects on the flow characteristics. [ABSTRACT FROM AUTHOR]

The process of frazil jam evolution in ice-covered rivers is not well understood. In this paper, under cover transport of frazil granules and its relation to frazil jam evolution in rivers are studied. A concept of ice transport capacity by analogy to bed sediment transport is developed and validated with the field data obtained from the Hequ reach of the Yellow River. The analysis of field data shows that the ice-transport capacity can be described by existing bed load transport formulas for low-density sediments. In view of various shapes of frazil granules that can form in different rivers, the effect of particle shape on the transport capacity is studied. Laboratory experiments are carried out using low-density chips to determine the transport rate over a wide range of flow conditions that are applicable to frazil transport. A generalized cover load transport formula taking into consideration the shape of the particles is obtained based on the laboratory data. [ABSTRACT FROM AUTHOR]

Anchor ice can cause significant water level and discharge fluctuations in rivers. This study presents an analysis of anchor ice effects on water level and discharge in the Peace River. Field data collected in two winters from the Peace River are analyzed using a river ice model that include the anchor ice process and effects. The anchor processes considered include the bed elevation change due to anchor ice, the change in discharge due to the mass flux of anchor ice growth and release, and the change in ice-bed roughness due to anchor ice growth and release. The analysis showed that the dominating contributing factor to the water level and discharge fluctuations, i.e. anchor ice waves, by anchor ice is the changing ice-bed roughness. This suggests the need for further studies on developing a formulation on ice-bed roughness. The field data also showed that the anchor ice waves occurred over a longer period towards downstream as the water temperature decreases towards downstream during the freezing period, and the anchor ice wave decays while travelling downstream due to the energy loss, but enhanced by anchor ice waves generated along the way. • Anchor ice effects on water level and discharge in Peace River for two consecutive winters were analyzed. • Anchor ice could produce disturbance to discharge and stages. The stage increase could reach to about 30% of the flow depth. • Anchor ice waves are caused mainly by the changing ice-bed roughness due to anchor ice growth and release. [ABSTRACT FROM AUTHOR]

Presents a discussion of the accumulation and under cover transport of frazil granules. Shear stress on the underside of the jam; Ratio between the hydraulic radius and the river bed.

Hydro-morphological conditions in rivers can change significantly with the presence of ice. These changes can affect fish habitat, which can have important effects on fish mortality during the winter months. It is important to consider thermal-ice processes and their interactions with channel morphology in fish habitat models. In this paper, a review of wintertime fish habitat preference is presented and used to develop recommendations for habitat suitability curves for the winter period. A case study was used to illustrate the importance of considering the winter period when determining changes to fish habitat due to river restoration efforts. The impact of the dam removal on fish habitat quality for both open water and ice affected conditions were evaluated using existing water habitat suitability curves as well as the developed winter curves. River conditions were simulated with a two-dimensional hydro-thermal-ice-sediment river dynamic model coupled with an IFIM and PHABSIM type fish habitat suitability model. The model considers thermal-ice as well as sediment and bed change conditions in rivers to allow for more detailed habitat suitability evaluation than previous models. Simulations show habitat quality will improve for both open water and ice affected conditions in the restored reach of the St. Regis River. • A river ice model was modified to include a wintertime fish habitat suitability model. • A review of wintertime fish behaviour literature was used to develop wintertime habitat suitability curves for salmonids. • The model can be used to evaluate changes to habitat for open water and ice affected periods. • A dam removal case study demonstrated the model's ability to simulate changes in habitat for open water and ice periods. [ABSTRACT FROM AUTHOR]

Destructive tsunamis can destroy coastal structures and move huge amounts of tsunami debris. Our current understanding of motion of tsunami debris in tsunami flows is limited. In this paper, we present a preliminary laboratory study of motion of model debris under the action of solitary waves running up a beach. The difference between the waterline of maximum inundation and the final position of debris was examined under various conditions. Effects of solitary wave height, water depth, and the distance of debris source to the shoreline on the maximum inundation, the debris limit, and the final position of debris were examined. In general, the final positions of the debris are different from the waterline at maximum inundation and there is a low possibility that a large amount of debris can be carried by retreating water offshore into the sea. [ABSTRACT FROM AUTHOR]

Freeze-up jamming on regulated rivers is an important aspect of cold regions hydropower operations. The timing and nature of freeze-up jamming has a role in reducing effects to winter discharge conveyance. In northern regions with very mild-sloped rivers, skim ice run is of considerable importance to the formation of a thin and stable cover with low hydraulic resistance. This paper presents a detailed review of skim ice run, including quantitative methods for predicting skim ice formation and a description of its behavior during freeze-up jamming. The review is supplemented by site observations from a large northern regulated river which experiences significant skim ice runs during winter. Following this, a treatment of skim ice run during freeze-up jam simulations is presented for a two-dimensional river ice model (Shen, 2010). The treatment includes implementation of empirical equations to establish skim ice run formation thickness, estimate skim ice floe strength as a function of thermal growth, and facilitate ice cover formation under varying discharge and air temperature conditions. Simulations illustrate the role of temporary discharge reductions on both the formation rate and thickness of ice jams formed mainly by skim ice runs. Further, these simulations highlight that profiles of ice jams formed under cold conditions show smaller final thicknesses relative to those formed under warmer conditions, due to the reduced strength of ice floes formed in warm weather. A brief sensitivity analysis evaluates the cumulative effect of concurrent changes to air temperature and discharge, as well as the impact of varying channel characteristics (i.e., sinuosity and bed slope). Enhancing capabilities of the model to simulate freeze-up jams creates potential for industrial applications, where anticipating the effects of discharge and air temperature on ice jam formation is often of paramount importance for river ice management. • Skim ice run can be important for freeze-up on very mild-sloped rivers. • Skim ice floes exhibit different properties from frazil ice pans. • Strength and stability of skim ice floes contributes to thin ice jam profiles. • Cumulative effects of discharge and heat loss impact freeze-up jam simulations. [ABSTRACT FROM AUTHOR]

Ice processes in general, and ice jams in particular, play a dominant role in the hydrologic regime of Canadian rivers, often causing extreme floods and affecting the life cycle of many aquatic, terrestrial, and avian species. Various numerical models have been developed to help simulate the formation and consequences of these very dynamic and often destructive jam events. To test and compare the performance of existing models, a series of three tests have been devised and coordinated by a task force appointed by the Committee on River Ice Processes and the Environment (CRIPE). The results indicate that the overall performance of the models is good when calibration data are available, but considerably more varied when the models are applied in uncalibrated or 'blind' mode. However, the diversity of results in the blind mode may be attributed more to the variations in perceptions of the physical processes by the users, as compared to the mechanics of the numerical computations. [ABSTRACT FROM AUTHOR]

River ice researchers have noted the strong dependence of ice cover formation during freeze-up on the air temperature, which influences the ability of the cover to grow a surface ice crust which can quickly add significant resistance to mechanical thickening. However, this link between thermal and dynamic ice processes is often absent in numerical models. In this paper, a new formulation is implemented in a two-dimensional river ice model, which considers the growth of a surface ice crust in a forming ice cover and the associated increase in resistance to consolidation. The crust is permitted to grow based on a critical ice velocity criterion, and the compressive strength of the crust is specified by the user. The model simulates the failure and attendant consolidation of the ice cover in cases where the rate of thermal strengthening is exceeded by the rate of increase of applied forces. Simulations performed on an idealized channel demonstrate the effect of changing the air temperature and crust strength on ice cover formation. The new formulations better simulate the physical processes occurring at freeze-up, increasing the robustness of the model and its applicability to freeze-up scenarios, especially on steeper sloped channels which often exhibit secondary consolidations of the ice cover. • A river ice model was modified to simulate the growth of a surface crust and the attendant gain in strength of an ice cover. • Simulations demonstrate that the thickness of a rubble ice cover is related to the air temperature during its formation. • The revised model formulations require three user inputs to characterize the thermal strengthening process. • The revised model capable of simulating the interdependencies of thermal and dynamic river ice processes at freeze-up. [ABSTRACT FROM AUTHOR]