基于动态规划理论的MIKE21河网排水方案优化研究

针对南方平原河网面对汛期暴雨时段排水能力差而导致内涝的问题,选取太湖流域南浔区沈庄漾圩田河网作为研究对象,选取城市排涝相应防洪标准的暴雨强度,应用多目标动态规划理论,以河网水位与排涝时间为限制目标,结合圩区现有水利工程条件参数和调度规则,设定了3个水闸排水方案和5个水泵排水方案;基于河网地形、水文数据,构建MIKE21河网水动力模型,定量化模拟分析了闸泵联调联控工况下河网排水效果。结果表明：面临10年一遇及以下暴雨时,河网可采用水闸排水方案,且3个方案均能在24 h内将水位降至排涝下限水位;当面临20年以上及百年一遇暴雨时,河网需采用内外网联动的水泵排水方案,西部闸门至少开启2台水泵,才能保证在24 h内将水位下降至下限水位,其排水效果与水泵开启数量呈正相关。该研究成果可为南方平原河网的汛期排水调度与河网工程改造提供理论依据。

OPTIMIZATION OF MIKE21 RIVER NETWORK DRAINAGE SCHEME BASED ON DYNAMIC PLANNING THEORY

To address the problem of flooding caused by the poor drainage capacity of the river network in the southern plain during the flood season, this study selected the river network of Shenzhuangyang polder in Nanxun district of Taihu Lake basin as the research object, and the storm intensity of the corresponding flood control standard for urban drainage, applied the multi-objective dynamic planning theory, took the water level and drainage time of the river network as the limiting target, combined the existing water conservancy engineering parameters and scheduling rules in the polder area, and set up three sluice gates based on the topographic and hydrological data of the river network. A MIKE21 river network hydrodynamic model was constructed to quantitatively simulate and analyze the drainage effect of the river network under the joint regulation and control of the gates and pumps. The results showed that:when facing a rainstorm with a returning period of 10 years or less, the river network could adopt the sluice gate drainage scheme, and all three schemes could reduce the water level to the lower limit of drainage within 24 h; when facing a rainstorm with a returning period of more than 20 years to one hundred years, the river network needed to adopt the pump drainage scheme of internal and external network linkage. Except in the case of 1 pump at the western gate, which does not meet the 100-year drainage requirement, at least 2 pumps at the western gate must be opened to ensure that the water level is lowered to the lower limit within 24h, The drainage effect is positively related to the number of pumps on The results of the study can provide a theoretical basis for the scheduling of flooding and the renovation of river networks in the southern plain. The results of the study can provide a theoretical basis for flood drainage scheduling and river network renovation in the southern plain river network.