黄河内蒙古段凌洪灾害及防凌减灾对策

Ice Flood Disaster and Its Reduction Measures in the Inner Mongolia Section of the Yellow River

黄河内蒙古段由于特定的地理位置和水文气象条件，决定了每年都发生凌汛。流凌封冻溯源而上，解冻开河则山上而下，冰水汇流，卡冰结坝而造成凌洪灾害。１９６８年上游刘家峡水库建成，调节了水量、热量，内蒙古段凌洪灾害有所减轻。１９８６年龙羊峡水库建成，汛期大流量减少，由于水沙异源，内蒙占段河床逐年淤积抬升，过流能力明显下降，凌洪灾害逐年增加。因此防治凌害，主要应采取加固堤防，整治河道，加强冰情预报，合理运用水库调度和局部破冰措施，并尽快在内蒙古段修建海渤湾水库，才能有效地减轻凌洪灾害。

Iee flood occurs yearly in the Inner Mongolia Section of the Yellow River for its particu-lar geographic location and hydrometeorogical conditions． Freeze up occurs upstream butbreak up downstream. As a result of break up，ice pack flows with water and clogs together toform an ice jam，causing ice－jam flood disaster．The disaster in the Inner Mongolia Sectionhad reduced in some degree since the completion of Liujiaxia Reservoir in 1968，as the reser-voir is operated against ice flood by regulating its discharge and heat flux as well．Largedischarge during iee flood period decreases after the completion of Longyangxia Reservoir in1986．Since then，however，the river bed has accreted in the lnner Mongolia Sectionfor thewater and sand come from different sources． Thus the flow capacity decreases obviously，andthen ice fiood disaster increases year by year. For reducing the ice flood disaster effectively it is necessary to realign the river，tostrengthen the levee，to reinfore the ice forecast， to regulate the reservoirs more satisfactorily，to take local iee breaking measures and to build the Haibuowan Reservoir in the InnerMongolia Section as soon as posible.