Remote data collection on ice breakup dynamics: Saint John River case study
Spyros Beltaos
a,
⁎
, Robert Rowsell
a
, Patrick Tang
b,1
a
National Water Research Institute, Environment Canada, Burlington, Canada
b
New Brunswick Department of the Environment, Fredericton, Canada
abstractarticle info
Article history:
Received 12 January 2011
Accepted 24 March 2011
Keywords:
Breakup
Hydrodynamic properties
Ice jam
Pressure logger
Remote measurement
Wave
Dynamic processes that occur during the breakup of river ice covers have important socio-economic and
ecological impacts, but development of predictive capability is hampered by the brevity of the event and the
ever-changing flow and ice conditions. The spatial and temporal variation of river water levels reflects the
evolution of breakup processes and may be used to quantify their characteristics. However, various practical
difficulties in measuring such variations have contributed to a scarcity of relevant data. A recently developed
technique for remote recording of river levels involves pre-breakup deployment of portable pressure loggers,
which are retrieved weeks or months later. Logger memory can accommodate high sampling frequencies,
sufficient to capture very rapid water level changes. Application of this technique to document a highly
dynamic breakup in the Saint John River, New Brunswick, resulted in an extensive data set. The processed
logger output is described in detail and shown to furnish important insights on the chronology of breakup
events. Analysis of the water level records that were obtained at different locations resulted in quantification
of the hydrodynamic properties of waves generated by ice jam releases, also known as “javes”. Jave-induced
amplification of flow and shear stress decreased with traveled distance, being between 2.5 and 3.0 at a
distance of 11 km. Extensive mobilization of the riverbed during the passage of javes in the study reach is
likely. Application of a numerical model to the measured WL profile of a major ice jam resulted in default-
range calibration coefficients, further corroborating current modeling capability.
Crown Copyright © 2011 Published by Elsevier B.V. All rights reserved.
1. Introduction
The breakup of the winter ice cover in rivers is typically a brief event
spanning the transition from the relatively complete and integral
winter cover to the open-water condition. Often attended by major ice
jams that cause rapid increases in river stage and flow velocities, the
breakup of river ice has the potential to intensify ecosystem
disturbance, disrupt the biota community, abrade stream banks, alter
channel morphology, transport large quantities of fine-grained mate-
rial and associated contaminants, and change mixing processes and
thus water quality. Furthermore, ice jams that form during breakup can
result in ice and flood damage to infrastructure and interference with
navigation and hydropower generation (Burrell, 2008). The emerging
issue of climate variability and change underscores the need for reliable
prediction tools to assess future river ice breakup regimes, as may result
from modified hydro-climatic conditions. Long-term stability of aquatic
ecosystems as well as security of local residents and infrastructure
could be adversely influenced by changed ice regimes, depending on
site specific conditions.
River ice breakup and jamming are complex phenomena, owing to
the multitude of processes that are occurring simultaneously and
interacting with each other. These processes can be structural,
thermodynamic, hydrodynamic, hydrologic, meteorological and geo-
morphic. Waves generated by ice jam releases are much sharper than
the better-known runoff waves and can greatly amplify flow velocities
and hydrodynamic forces (Jasek and Beltaos, 2008). Called “javes” for
short, these waves can damage habitat and infrastructure, but can also
provide the driving mechanism for dynamic breakup in the flat, lower
segments of rivers (Beltaos, 2007).
The highly dynamic nature of breakup is at least partly responsible
for gaps in the knowledge that is presently available for quantitative
prediction of the timing, location, magnitude, and evolution of ice
jams and javes. Additional factors include the sudden onset and
brevity of breakup, as well as lack of road access to many river
stretches and lack of specialized instrumentation. Dynamic river ice
processes continuously influence, and are influenced by, the water
surface elevation or water level (WL for short) along the river. Its
spatial and temporal variation is one of the most important variables
that need to be measured during the breakup event. Typically, WL
data are only available at hydrometric gauging stations that are
operated and maintained by national or regional water resources
agencies, such as the Water Survey of Canada (WSC). The primary
purpose of these stations is to gather sufficient information for
assessing river discharge, which is subject to moderate spatial
variability. Consequently, the gage network is far too sparse for
detailed study of dynamic river ice processes, which are known to be
Cold Regions Science and Technology 67 (2011) 135–145
⁎ Corresponding author. Tel.: + 1 905 336 4898; fax: +1 905 336 4420.
E-mail address: spyros.beltaos@ec.gc.ca (S. Beltaos).
1
Retired.
0165-232X/$ – see front matter. Crown Copyright © 2011 Published by Elsevier B.V. All rights reserved.
doi:10.1016/j.coldregions.2011.03.005
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