NWT RESEARCH DATABASE

Regions: Dehcho Region

Tags: physical sciences, hydrology, prediction models, historical data, spring breakup, ice jams, waterflow monitoring

Objective(s): Our objective is to study ice processes on the Hay River in order to facilitate our development of computer models to predict them. The hydraulic modeling techniques being employed also have the potential to address local issues such as the effects of berming and channel infilling on ice jam occurrence and severity.

Project Description: Our objective is to study ice processes on the Hay River in order to facilitate our development of computer models to predict them. The hydraulic modeling techniques being employed also have the potential to address local issues such as the effects of berming and channel infilling on ice jam occurrence and severity. The researcher would ultimately like to be able to provide some flood warning tools to the community and to explore the impacts of development and climate variability on the frequency and severity of breakup ice jams. In order to develop realistic models, it is important that the researchers have the opportunity to observe river breakup (and, if possible, freezeup) in order to have a full understanding of the physical context of the historical data. The primary objective for 2010 is to document the daily progression of river ice breakup, which we would do from small aircraft and also from the ground, since there are numerous road access points along the river. Much of the relevant data is already collected by the Town Flood Watch Committee during breakup, so our primary focus is on obtaining data that is complementary to their efforts. During breakup: From the air, digital photographs, video and new 'Geographical Information System' mapping software are the means by which we document river breakup as this is the best vantage point to see all segments of the river along the study reach. Additionally high resolution photos taken from the air and the ground in conjunction with the targets setup during the late winter field trip would be used to produce 3 dimensional models of the ice cover. Representatives from the Town of Hay River and the Kátl`odeeche First Nation will be invited to participate in these observation flights. On the ground, transportation would be by vehicle (SUV or pick-up truck). Photographs and video would also be taken on the ground at accessible points along the river, particularly during ice movement events. The researcher would also measure water and ice levels, before and after ice movements, when and where it is safe to do so. Water and ice level measurements are done with standard survey instruments (typically using a surveyor's rod and level, or with computerized survey instruments known as a 'total station' and ‘global positioning system’). Additionally, dataloggers would be deployed to allow automated collection of ice/water elevations and ice run velocities. None of these types of measurements have any environmental impact. The timing of this breakup survey will depend on weather conditions leading to spring thaw, but historical averages show us the Hay River ice cover breaks up in late April and early May. The research team will mobilize and travel to the Town when reports and weather forecasts suggest breakup may soon commence. Members of the local community, including the Town of Hay River and the Kátl`odeeche First Nation, have been invited to accompany researchers on observational flights documenting breakup and will have the opportunity to assist with the field program. Some funding is available to hire members of these groups to aid with the field work. These groups also have the opportunity to provide input to the study in terms of information on issues and concerns that can be incorporated into the research. The fieldwork for this study will be conducted from March, 2010 to May 31, 2010.