Ice-Cover and Jamming Effects on Inline Structures and Upstream Water Levels

River ice cover is a reoccurring phenomenon in the Northern United States every year. Sheets and layers of ice result in a rise of water surface elevation and may lead to ice jams in a river. This research explains the modeling of a river reach through Northern Illinois containing a structural weir and how the water profile is effected during ice cover and ice jam events. The Hydraulic Engineering Center’s River Analysis System was used in conjunction with Esri ArcMap software to model a portion of the river for analysis. The study area of the Rock River flowing through Oregon, IL is known to freeze and ice over during the winter months in Northern Illinois. Data from the United States Geological Survey and National Oceanic and Atmospheric Administration were utilized to obtain cross-section and discharge measurements. The impacts of an ice jam occurring upstream of the weir and downstream of the weir were studied. The effects of the ice jam on the upstream water levels were also evaluated to observe if any flooding may occur inside the town or even farther upstream. Results of the ice cover and ice jam data were then compared to those of the Rock River under normal open flow conditions thus observing the change in water level, Froude number, and flow velocity. Results from this study help to point out the significance of ice jam occurrences and their effects on inline structures and future flooding concerns in the surrounding area

Comparative analysis of spring flood risk reduction measures in Alaska, United States and the Sakha Republic, Russia

Thesis (Ph.D.) University of Alaska Fairbanks, 2017River ice thaw and breakup are an annual springtime phenomena in the North. Depending on regional weather patterns and river morphology, breakups can result in catastrophic floods in exposed and vulnerable communities. Breakup flood risk is especially high in rural and remote northern communities, where flood relief and recovery are complicated by unique geographical and climatological features, and limited physical and communication infrastructure. Proactive spring flood management would significantly minimize the adverse impacts of spring floods. Proactive flood management entails flood risk reduction through advances in ice jam and flood prevention, forecasting and mitigation, and community preparedness. With the goal to identify best practices in spring flood risk reduction, I conducted a comparative case study between two flood-prone communities, Galena in Alaska, United States and Edeytsy in the Sakha Republic, Russia. Within a week from each other, Galena and Edeytsy sustained major floods in May 2013. Methods included focus groups with the representatives from flood managing agencies, surveys of families impacted by the 2013 floods, observations on site, and archival review. Comparative parameters of the study included natural and human causes of spring floods, effectiveness of spring flood mitigation and preparedness strategies, and the role of interagency communication and cooperation in flood risk reduction. The analysis revealed that spring flood risk in Galena and Edeytsy results from complex interactions among a series of natural processes and human actions that generate conditions of hazard, exposure, and vulnerability. Therefore, flood risk in Galena and Edeytsy can be reduced by managing conditions of ice-jam floods, and decreasing exposure and vulnerability of the at-risk populations. Implementing the Pressure and Release model to analyze the vulnerability progression of Edeytsy and Galena points to common root causes at the two research sites, including colonial heritage, unequal distribution of resources and power, top-down governance, and limited inclusion of local communities in the decision-making process. To construct an appropriate flood risk reduction framework it is important to establish a dialogue among the diverse stakeholders on potential solutions, arriving at a range of top-down and bottom-up initiatives and in conjunction selecting the appropriate strategies. Both communities have progressed in terms of greater awareness of the hazard, reduction in vulnerabilities, and a shift to more reliance on shelter-in-place. However, in neither community have needed improvements in levee protection been completed. Dialogue between outside authorities and the community begins earlier and is more intensive for Edeytsy, perhaps accounting for Edeytsy's more favorable rating of risk management and response than Galena's

Climate-driven Shifts in Quantity and Seasonality of River Discharge over the past 1000 Years from the Hydrographic Apex of North America

Runoff generated from high elevations is the primary source of freshwater for western North America, yet this critical resource is managed on the basis of short instrumental records that capture an insufficient range of climatic conditions. Here we probe the effects of climate change over the past ~1000 years on river discharge in the upper Mackenzie River system based on paleoenvironmental information from the Peace-Athabasca Delta. The delta landscape responds to hydroclimatic changes with marked variability, while Lake Athabasca level appears to directly monitor overall water availability. The latter fluctuated systematically over the past millennium, with the highest levels occurring in concert with maximum glacier extent during the Little Ice Age, and the lowest during the 11th century, prior to medieval glacier expansion. Recent climate-driven hydrological change appears to be on a trajectory to even lower levels as high-elevation snow and glacier meltwater contributions both continue to decline

Effects of seasonability and variability of streamflow on nearshore coastal areas: final report

General nature and scope of the study: This study examines the variability of streamflow in all gaged Alaskan rivers and streams which terminate in the ocean. Forty-one such streams have been gaged for varying periods of time by the U. S. Geological Survey, Water Resources Division. Attempts have been made to characterize streamflow statistically using standard hydrological methods. The analysis scheme which was employed is shown in the flow chart which follows. In addition to the statistical characterization, the following will be described for each stream when possible: 1. average period of break-up initiation (10-day period) 2. average period of freeze-up (10-day period) 3. miscellaneous break-up and freeze-up data. 4. relative hypsometric curve for each basin 5. observations on past ice-jam flooding 6. verbal description of annual flow variation 7. original indices developed in this study to relate streamflow variability to basin characteristics and regional climate.This study was supported under contract 03-5-022-56, Task Order #4, Research Unit #111, between the University of Alaska and NOAA, Department of Commerce to which funds were provided by the Bureau of Land Management through an interagency agreement

Modeling the Release of River Ice Jams and their Impact on River Bed Scouring.

The Great Lakes are the largest fresh water reservoir on the planet. Lakes Huron and Michigan drain into Lake Erie through the Huron Erie Corridor. The average water level in Lake Huron has been dropping. The results of hydrodynamic model simulations imply that there has been an increase in the conveyance of St. Clair River that took place in the 1980’s. 1984 was marked by a massive ice jam. The jam had a duration of 24 days and its release was accompanied by high flow velocities. It is speculated that the high water flow velocities following the release of the jam caused scouring of the river bed, that lead to an increase in conveyance. A model is developed to simulate changing river bed morphology, and is combined with a hydrodynamic model in order to simulate scouring during the release of an ice jam. The model consists of modeling the river bed morphology, finding the sediment fluxes on the bed, and updating the bed morphology when scouring occurs. The hydrodynamic model uses a step-wise approximation for the bed morphology. A geometric scheme is developed to compute the local angle of inclination. The bed elevation is updated by numerically solving the Exner equation by using a finite volume approach. A new methodology is developed in order to adapt the grid to the changing bed morphology. The ice jam is modeled as an initially stationary body of water. Water is allowed to flow freely under the body. The body of water is released in the flow, accelerating and causing flow velocities over the entire river to rise rapidly. It is found that an ice jam similar to the 1984 ice jam will cause scouring of the river bed.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/99841/1/mihalis_1.pd

IMPACTS OF CLIMATE AND REGULATION ON ICE-JAM FLOODING OF NORTHERN RIVERS AND THEIR INLAND DELTAS

In cold region environments, ice-jam floods (IJFs) are important hydrological and hydraulic events that play an important role in floodplain ecology but also pose a major concern for citizens, authorities, insurance companies and government agencies, primarily because they can result in high water depths in rivers that can exceed levees leading to devastating floods. In the past 35 years, there have been significant advances in river ice hydrology. However, understanding on several aspects of IJFs still remains limited. Little work has been carried out on investigating how the frequency and severity of IJFs have been changing or might change in the future. Similarly, IJF delineation remains a significant challenge even for streams and small rivers. There is also still substantial progress to be made in quantifying the effects of climate variability and regulation on IJFs. This dissertation addresses some of these existing knowledge gaps. First, it reviews the recent advances in IJF research and identifies existing gaps, challenges and opportunities. With a changing environment, there are implications for river ice processes and this dissertation work investigates some of the potential implications particularly how the timing and magnitude of breakup flows that lead to IJFs are changing at local and regional levels. Literature review shows IJF research has been highly site specific but this dissertation also offers regional and global perspectives. Climate and anthropogenic factors are likely to have unequal localized effects. Some regions might be more resilient and others, such as high latitude northern regions, might be more vulnerable. Thus, local implications for river ice processes and current and future probabilities of IJFs are assessed for two river basins in western Canada. The findings from the Athabasca River at the town of Fort McMurray show that the probability of ice-jam flooding in the future will be lower but extreme IJF events are still probable. The results from the town of the Peace River in western Canada suggest that regulation can have larger role in increasing IJF risks as water levels during ice-jam staging at the town were found to be higher due to regulation compared to naturalized conditions. However, regulation also offers a possibility of reducing IJF risks and promoting sustainability in regulated rivers. It is demonstrated that with appropriate reservoir operation scheme, it is feasible to minimize flood risk at upstream communities and maximize flood potential at downstream deltaic ecosystem, where it is essential. As ice-jam flooding, both at present and in the future, remains a major concern in northern IJF prone communities, a probability curve of overbank flow based on breakup discharge is presented. Using a stochastic approach to evaluate the impacts of different magnitudes of discharge on IJF is a novel approach, and serves as an important benchmark for future IJF studies, especially for estimating future IJF probabilities. One other important methodological contribution is the introduction of a probability-based extension of the hydro-technical modelling approach that couples physically-based hydrologic and hydraulic models to assess the relative impacts of climate and regulation within a stochastic framework. Thus, the findings of this work have advanced our understanding of impacts of climate and regulation on ice-jam flooding of northern rivers and their inland deltas. As the first step in reducing flood risks, identifying, understanding and quantifying flood hazard will improve our ability to reduce risks and increase resiliency

Use of LANDSAT data for river and lake ice engineering studies

There are no author-identified significant results in this report

Statistical characterization of ice jams in Canadian rivers

Examines the hydrometeorologic variables which can be used to predict freeze-up and breakup dates as well as ice jam occurences

Ice Dynamics Preceding Catastrophic Disintegration of the Floating Part of Jakobshavn Isbrie, Greenland

The floating terminal of Jakobshavn Isbr ae, the fastest Greenland ice stream, has disintegrated since 2002, resulting in a doubling of ice velocity and rapidly lowering inland ice elevations. Conditions prior to disintegration were modeled using control theory in a plane-stress solution, and the Missoula model of ice-shelf flow. Both approaches pointed to a mechanism that inhibits ice flow and that is not captured by either approach. Jamming of flow, an inherent property of granular materials passing through a constriction (Jakobshavn Isfjord), is postulated as the mechanism. Rapid disintegration of heavily crevassed floating ice accompanies break-up of the ice jam

Ice Dynamics Preceding Catastrophic Disintegration of the Floating Part of Jakobshavn Isbræ, Greenland

The floating terminal of Jakobshavn Isbræ, the fastest Greenland ice stream, has disintegrated since 2002, resulting in a doubling of ice velocity and rapidly lowering inland ice elevations. Conditions prior to disintegration were modeled using control theory in a plane-stress solution, and the Missoula model of ice-shelf flow. Both approaches pointed to a mechanism that inhibits ice flow and that is not captured by either approach. Jamming of flow, an inherent property of granular materials passing through a constriction (Jakobshavn Isfjord), is postulated as the mechanism. Rapid disintegration of heavily crevassed floating ice accompanies break-up of the ice jam