长距离调水明渠冬季输水冰情分析与安全调度

结合南水北调中线总干渠2011年-2016年间5个冬季冰情原型观测数据,分析了冰情时空分布特征、冰盖厚度、冰情现象、冰情演变条件和特点等。2015年-2016年冬季输水流量大,渠道水流流速0.25~0.67m/s,加之遭遇罕见寒潮(-18.6℃)的叠加,局部渠段出现冰塞现象。结合总干渠闸前常水位运行调度方式和渠池水流特点,提出了避免形成冰塞灾害的水流控制条件。即渠池上游控制断面平均流速V≤0.40m/s,Fr≤0.065;下游控制断面平均流速V≤0.35m/s,Fr≤0.055。建议持续加强全线冰情观测,积累冰期输水观测数据,为优化冬季输水运行调度和冰情预报提供科学依据。

Ice regime analysis and safe dispatch research on long distance water diversion project in winter

The paper analyzed the temporal and spatial distribution characteristics of ice regime and ice thickness ,with ice regime prototype observation data at South‐to‐North Water Diversion Middle Route Project in 5 winters during 2011 -2016 .In the winter of 2015 to 2016 ,ice jam occurred in local canal ,because of large discharge ,0 .25~0 .67 m/s flow velocity and cold air (-18 .6 ℃) .Combined with the dispatching mode of constant water level in front of the gate and canal pool flow characteristics , water control condition was proposed to avoid the formation of ice jam disaster .The upstream section of canal pool should be controlled with V ≤0 .40 m/s ,Fr≤0 .065 .the downstream section should be controlled with V ≤0 .35 m/s ,Fr≤0 .055 .It was recommended to increase the full line of ice regime observation and collect more ice observation data ,in order to set up scientific basis to optimize the water supply operation scheduling and ice regime forecast in winter .