PROGRESS AND TREND IN THE STUDY OF RIVER ICE HYDRAULICS

This study reviews the latest research progress on the basic theory of river ice hydraulics, river ice modeling and ice flooding forecasting, key ice parameters recording equipment and technology in China and other countries. The river ice hydraulics is constructed of water heat budget analysis, ice runs interactions and transport, anchor ice and border ice formation and release, ice jamming in freezing period, ice dam in breakup period, and ice jamming before infrastructure, the flow-ice-sediment coupled mechanics. Through detailed analysis on recent research progresses and existing questions of ice hydraulics and engineering applications, this study proposes several promising research topics in the future. It is still challenging in understanding the ice dynamics in terms of the anchor ice growth and release, ice stoppage and initial ice cover formation driven by thermal-dynamic-geometrical properties, flow structures under ice-covered compound channels, and flow-ice-sediment coupling mechanics in riverbank retreats. In terms of ice information forecast under changeable situations, it is helpful to focus on influence of long-term climate change and short-term extreme events on northern river ice flooding. The development of hydrology and hydraulics coupled forecasting model is promising in combining different spatial and temporal scales for supporting ice flooding prevention. For ice flooding monitoring system and disaster prevention equipment, it is suggested to record seepage flow in ice jam, internal ice resistance and friction, physical structure evolution in ice jam to collect field observation database. In terms of glacial lake outburst floods, laboratory experiments are needed in exploring opening mechanics under freezing environment and promoting interdisciplinary research, especially in processes of outburst flow erosion, moraine soil undercut and side slope collapses.