Inland navigation had played a key role for physical distribution in earlier times. As railway androad had developed, however, inland navigation had declined. Recently, inland navigation draw renewed attentions from the aspects of reduce of physical distribution cost and global environmental problem.
Ishikari River is located in cold region and it is known that the water is frozen in winter season. So the measurements for the ice problem are needed on the facility of inland navigation.
In this study, some measures of ice problem for locks are considered.
