(一) 在我国北方,国民經济的許多部門都是与江河湖泊的冰情密切关联的。要想多快好省地完成这些部門的生产建設任务,就必須能够正确地預見到未来的冰情,从而也就要善于利用冰情預报。例如,冬季河道上的水利水电建設和桥梁施工,若能預知春季开河的情势与流凌的多寡,就可以恰当地布置防泄措施,既 (1) In northern China, many sectors of the national economy are closely linked to the ice conditions of rivers and lakes. In order to accomplish the tasks of production and construction in these departments more quickly and economically, we must be able to correctly foresee the future of ice conditions and thus make good use of the ice conditions forecast. For example, water conservancy and hydropower construction and bridge construction in winter rivers can be properly arranged with anti-venting measures if they are predictable on the conditions of the spring and on the flow rates. Both