| Résumé | Flooding along river shorelines often results from ice-related phenomena, such as ice jams. Severe ice jams and associated floods can have major socioeconomic impacts, not only on people’s safety and property but also on the security of infrastructure, transportation, inland navigation, and energy generation. The significance of ice jams to flooding at the national level and beyond has not been adequately documented, and not enough is known about whether/how their frequency is responding to the changing climate. To address these requirements, there is a need for a database of flooding events induced by river ice and ice jam floods (IJF) in Canada, including relevant information, such as year and date, extent of floods, and damage costs.
This report is to assess how to best approach the makeup of such a database. It begins with an overview of river ice and the factors leading to the formation of ice jams, defined as a stationary accumulation of fragmented ice or frazil that restricts flow. The large thickness and extreme roughness of the ice under- surface can cause very high water levels and overland flooding, even with moderate river discharges. A review was conducted as part of this study on existing methods to model river ice and anticipate the formation of ice jams. These models are of two types: those that capture the physics of the processes governing river ice development, and those that are data-driven i.e., they rely on statistical data. This review allows for an appreciation of the data that could be incorporated into a database.
A review was also conducted on pre-existing databases – eleven such databases are described, each addressing various aspects of river ice from a different perspective: They are: the Canadian River Ice Database (CRID), the Cold Regions Research and Engineering Laboratory (CRREL) database, the Historique d'embâcles répertoriés from the Government of Quebec’s Ministère de la Sécurité Publique (MSP), the Canadian Ice Database (CID), the Historical Flood Events database from Natural Resources Canada (NRCan) and ECCC, the River Watch Program (RWP) in Alaska, the Global Lake and River Ice Phenology Database, Alberta River Basin’s database, the Regional Municipality of Wood Buffalo’s (RMWD) database, the Russian River Ice Thickness and Duration database, and the National Ice Jam Database. A description of each is provided, as well as an explanation of the data they enclose. Three other databases, not strictly relevant for river ice but of interest nonetheless, are briefly described: HydroSHEDS’ Global River Classification (GLORIC), European Union’s Copernicus database, and University of New Hampshire’s ArcticRIMS. Database design takes into account data entry, for which little information was found, and data access, typically via the Internet. In most cases, the data can be accessed by downloading data files or by navigating interactive maps and extracting data from that exploration.
Based on the foregoing, a database is seen as having a dual ‘vocation’: a) to provide data that can help understand these phenomena – the target users have expertise in river ice hydraulics and hydrology; and b) To provide information that can help prepare against these phenomena – in this case, the target users are community stakeholders. A simplified sequence of steps is proposed for the development of a new database, drawing from the previously existing ones: deciding on who would be the end users, determining what their needs are, figuring out the data sources, orchestrating database design, its content and how it would be made accessible to the users, planning the resources required (technical, timelines, material), database delivery, and database maintenance. While the database would be centered primarily on IJFs in Canada, it could enclose data from elsewhere. The database should be seen as a communication vehicle of scientific relevance, as is the case for research papers. Finally, the larger the audience for this product (by envisaging a wide user base in database planning), the more interest it would spur from organizations that are concerned with IJFs. This would maximize opportunities to leverage funding sources for everyone’s benefit. |
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