U.S. Army Engineer Research and Development Center, Hanover, New Hampshire
Method to Estimate River Ice Thickness
Based on Meteorological Data
Some knowledge of ice thickness is required for the design of
structures--such as bridges, dams, weirs, locks, piers, intakes,
channel stabilization measures, and coastal shoreline protection--
in ice-affected rivers. One recent case illustrating the need for
considering ice in the design of riverine structures is the failure of
the McKeesport (Pennsylvania) Marina on the Youghiogheny
River in January 2001 (Fig. 1 [Silver and Fuoco 2001] and 2). The
marina was constructed in 1997 at a cost of more than million.
According to the ERDC-CRREL Ice Jam Database sources
(National Weather Service 2001a, b; Veltri 2001), ice jam
breakup, jamming, and failure resulted in the complete destruction
of the marina by chunks of ice measuring up to one foot thick.
Contemporary reports estimated that the damage began around
Figure 1. Twisted docks at McKees Point Marina
6:30 p.m. on 31 January, and by 8:37 p.m., the marina was torn
on the Youghiogheny River, Pennsylvania. Photo by
away. Reconstruction costs for the marina have been estimated at
Darrell Sapp, Post-Gazette.
Ice covers and ice jams can cause rapid increases in stage that
can cause flooding and damage (Fig. 3). Numerical models of rivers to develop stage-frequency information required for
modeling ice jams for flood damage reduction measures, flood insurance studies, and changes to the ice regime that occur
from development in the floodplain or dam removal also require that ice thickness be estimated. Analyses of ice-induced
scour and erosion in ice-affected rivers must include knowledge of ice thickness.
Unlike discharge or stage measurements, observations of ice thickness can be challenging to locate. The USGS does
record ice thickness as part of its winter discharge measurements, but these records are often archived in paper form and can
be difficult to access. Some local flood warning systems measure ice thickness. A good example is the Nebraska Ice Warning
System (http://dnrdata.dnr.state.ne.us/Icejam/index.asp), which contains seasonal ice thickness measurements.
Given the lack of existing data, ice thickness
must often be estimated. Because ice covers result
from complex physical processes, there is not yet a
method to account for all factors affecting thickness.
This technical note presents a method to estimate ice
thickness that results from heat transfer processes
based on meteorological data.
Figure 2. Debris from the McKeesport Marina
trapped above Emsworth Locks and Dam on the Ohio
River about six miles downstream from Pittsburgh.
Photo by Andy Tuthill, ERDC-CRREL.
ERDC/CRREL Technical Note 04-3