Author(s): Hiroshi Saeki
Linked Author(s):
Keywords: No Keywords
Abstract: The coastline of the Sea of Okhotsk in Hokkaido is affected yearly by pack ice. It has become necessary to reduce the damage to fisheries and aquaculture facilities, whole year-round operation of harbors and ports. This paper clarifies tbe conditions to be required at facilities to control ice, and introduce pack ice control techniques currently being used or in the process of development, along with measures used to prevent freezing over. In developing optimal structures for controlling intrusion of pack ice into shore reef areas and the mouths of ports or lakes, such structures require sufficient construction funds and durability to preserve resources, and the quality of construction should be good enough to withstand waves as they are usually constructed in the breaker zone. The floating-type Ice Boom satisfies the required conditions better than the others and is optimal for controlling pack ice. In addition, a combination of several structures makes the control of ice floes much easier. The prevention of freezing in a contained area of water, the air bubble and artificial wave methods are possibilities, but when the influence of wind is taken into consideration, the artificial wave method proves to be very difficult. Also for the air bubble method, there are cases when the operation is impossible because of the conflicting relations of wind direction, wind velocity, and dispersal direction of frazil ice. With newly constructed harbors and fishing ports in cold weather regions where expected to freeze over, due consideration should be given to the relationship between wind direction and the harbor's geography.
Year: 1992