This book exposes practitioners and students to the theory and application of river and lake ice processes to gain a better understanding of these processes for modelling and forecasting. It focuses on the following processes of the surface water ice: freeze-up, ice cover thickening, ice cover breakup and ice jamming. The reader will receive a fundamental understanding of the physical processes of each component and how they are applied in monitoring and modelling ice covers during the winter season and forecasting ice floods. Exercises accompany each component to reinforce the theoretical principles learned. These exercises will also expose the reader to different tools to process data, such a space-borne remote sensing imagery for ice cover classification. A thread supporting numerical modelling of river ice and lake ice processes runs through the book.

The Ning-Meng reach of the Yellow River basin is located in the Inner Mongolia region at the Northern part of the Yellow River. Due to the special geographical conditions, the river flow direction is towards the North causing the Ning-Meng reach to freeze up every year in wintertime. Both during the freeze-up and break-up period, unfavourable conditions occur which may cause ice jamming and ice dam formation leading to dike breaching and overtopping of the embankment. Throughout history this has often led to considerable casualties and property loss. Enhanced economic development and human activities in the region have altered the characteristics of the ice regime in recent decades, leading to several ice disasters during freezing or breaking-up periods. The integrated water resources management plan developed by the Yellow River Conservancy Commission (YRCC) outlines the requirements for water regulation in the upper Yellow River during ice flood periods. YRCC is developing measures that not only safeguard against ice floods, but also assure the availability of adequate water resources. These provide the overall requirements for developing an ice regime forecasting system including lead-time prediction and required accuracy. In order to develop such a system, numerical modelling of ice floods is an essential component of current research at the YRCC, together with field observations and laboratory experiments. In order to properly model river ice processes it is necessary to adjust the hydrodynamic equations to account for thermodynamic effects. In this research, hydrological and meteorological data from 1950 to 2010 were used to analyse the characteristics of ice regimes in the past. Also, additional field observations were carried out for ice flood model calibration and validation. By combining meteorological forecasting models with statistical models, a medium to short range air temperature forecasting model for the Ning-Meng reach was established. These results were used to improve ice formation modelling and prolong lead-time prediction. The numerical ice flood model developed in this thesis for the Ning-Meng reach allows better forecasting of the ice regime and improved decision support for upstream reservoir regulation and taking appropriate measures for disaster risk reduction.

In cold regions, the breakup of river ice can be a significant event, resulting in flooding and damage to communities. Given the severity of such events, it is desirable to be able to predict the timing and severity of breakup. Limited progress has been made on forecasting breakup related flooding as no deterministic model of the breakup process and ice jam formation exist. Current tools for predicting breakup rely on developing a relationship between the previous winter conditions and the current spring conditions, with the understanding that a rapid or large runoff with a thick ice cover has the potential for a more severe breakup than if ice has had time to melt. These tools are largely empirical, statistical, or soft computing methods which rely on historical data sets of discrete observations to relate the complex relationship between climate and hydrology to breakup conditions and are limited by access to the extensive data required. Within the current prediction methods, the application of hydrological models for forecasting breakup timing and severity is limited. Hydrological models can address some of the limitations of current tools, as they are able to simulate the complex relationships between climate and hydrology which has a strong influence on the breakup period. Additionally, hydrological models may be more practical in regions with limited data, as they can simulate variables of interest instead of relying on large historical data sets. This thesis demonstrates how a hydrological model can be used to predict the timing and severity of breakup, through the coupling of a 1D river ice model with a hydrological model. Emphasis is placed on the development of the hydrological model to ensure that it provides realistic results throughout the basin. The Liard basin, a large relatively data sparse river basin, in northern Canada is used as a case study. A thorough calibration strategy, based on an iterative, multi-objective approach is used in the development of the model. The final model exhibits strong performance in both calibration and validation throughout the basin. A simple 1D river ice model in MATLAB is coupled with the hydrological model. The hydrological model can forecast the timing of breakup well based on the timing of the initial rise in the hydrograph. Breakup severity is predicted using a simple threshold model based on ice thickness, flow, and accumulated shortwave radiation. The prediction method was applied to an independent location as verification of the methodology with promising results.

The breakup of a river ice cover can be both fascinating and perilous, owing to ever-changing ice conditions and dynamic processes that sometimes lead to extreme flood events caused by ice jams. Though much progress has been made recently in the study of ice jams, less has been achieved on the more general, and more complex, problem of how to predict the entire breakup process, from the first ice movement to the last ice effect on river stage. This type of knowledge is essential to determining when and where ice jam threats may develop and when they may release and generate steep flood waves that can trigger ice runs and jamming further downstream. In turn, such understanding is invaluable to natural hazard reduction, ecosystem conservation and protection, and adaptation to climatic impacts. This book combines the existing information, previously scattered in various journals, conference proceedings, and technical reports. It contains contributions by several authors to achieve a comprehensive and balanced coverage, including qualitative and quantitative descriptions of relevant physical processes, forecasting methods and flood-frequency assessments, as well as ecological impacts and climatic considerations. The book should be of interest to readers of different backgrounds, both beginners and specialists. -- Publisher's website.