极端条件下联圩区外河网洪水安全研究

Research on flood safety in river network outside polder under extreme conditions

通过杭嘉湖地区长序列水文数据频率分析,选择典型设计暴雨,建立联圩区概化的河网非恒定流水动力学模型,计算外围洪水、潮水位胁迫下的极端设计洪水过程。考虑现有排涝安全格局条件,以及极端水文过程对河网防洪安全高度的潜在影响,以极端设计暴雨过程为例,对洛塘河小流域河网现状及校核条件下河堤约束进行计算,分析联圩区河网的防洪安全标准修正方法,建议进一步提升洛塘河星火、长春和斜西各圩区段的河道堤防防洪标准,以保证极端条件下洛塘河的防洪安全。

A typical design storm was chosen through frequency analysis of long series of hydrological data in the Hangjiahu area. A polder generalized unsteady flow dynamics model was established, and the flood process under the stress of peripheral flooding and tide level under extreme conditions were calculated. With consideration of the existing safety pattern of drainage conditions and the potential impact of extreme hydrological processes on the flood control safety elevation of the river network, an extreme design storm was taken as an example, the embankment height in the Luotang River watershed under the status quo and verification conditions of a river network was calculated, and the correction method of flood control safety standards in the polder area was analyzed. It is suggested that the flood control standards for the polder sections including Xinghuo, Changchun, and Xiexi be further improved, in order to ensure the safety of flood control in the Luotang River under extreme conditions.