通过分析杭州江北主城区涝灾成因和区域防御总体能力,优化城区排涝格局,提出城市包围方案,为开展新一轮城市防洪排涝规划和治理工程提供决策参考。基于区域已有的杭嘉湖区域水利综合规划、杭州市城市防洪减灾规划、杭州城西科创大走廊水利专项规划等推荐的水利防洪排涝工程基础上,采用一维河网非恒定流数学模型,建立杭嘉湖东部平原防洪水利计算模型,计算城市包围方案实施效果。研究结果表明,通过北控线建闸建泵并进行优化调度,杭州江北主城区既能满足排涝标准,主动防御,又能最大程度减轻对下游地区的防洪压力,兼顾流域防洪。该研究成果对确定城市防洪排涝方案具有借鉴意义。

On the basis of analyzing the causes of waterlogging and the overall regional defense capacity of Jiangbei urban district of Hangzhou City, we present urban encirclement schemes to optimize the drainage pattern in the hope of offering reference for the decision-making of flood control planning and regulation. At present in Hangzhou we already have a series of flood control and drainage projects including the comprehensive water resources planning for Hangzhou, Jiaxing, and Huzhou region (hereafter referred to as Hang-Jia-Hu region), the urban flood control and disaster reduction planning for Hangzhou City, the special planning of west Hangzhou Kechuang corridor, and others. Under such background, we established the one-dimensional unsteady flow mathematical model of flood control for the eastern plain of Hang-Jia-Hu region, and calculated the implementation effect and impacts of three urban encirclement schemes involving different arrangements of canals and control gates. Results show that by constructing sluices and pumps along the north control line and together with optimizing operation, the Jiangbei urban district of Hangzhou City could meet drainage standards and actively prevent from waterlogging on one hand, and reduce the flood control pressure on downstream areas to the greatest extent and take into account the flood control of the river basin on the other. The research finding is of referential value for the flood control and drainage of cities in the middle and upper reaches of the eastern Hang-Jia-Hu plain.