Abstract The integrated green–gray–blue (IGGB) system is considered to be a new way of stormwater management, and a comprehensive evaluation of the green–gray–blue infrastructure layout mode under different return periods is the key to the implementation decision-making of stormwater management. In this study, a blue–green synergism evaluation model is established to optimize the layout of blue–green infrastructure. An evaluation framework combining the evaluation indicator system and the hydrology model is established. Stormwater storage, peak flow reduction, and life cycle cost are selected as evaluation indicators. On this basis, seven optimal scenarios, including green, blue, gray, green–blue, green–gray, blue–gray, and green–gray–blue, are established. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method is used to analyze these seven scenarios under different return periods. The results indicate that (1) when the drainage infrastructures are arranged in combination, the peak flow reduction is significantly improved compared to that of a single drainage. (2) TOPSIS results show that green–gray and blue–gray perform better when the cost weight is 0–0.35, and green–gray–blue performs best when the cost weight is 0.35–1. (3) The integrated green–gray–blue system has obvious synergistic effects. This study can provide support for planning department workers for the urban stormwater management strategy.

中文翻译：

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多目标决策下城市洪水绿灰蓝一体化系统优化

摘要绿灰蓝综合系统（IGGB）被认为是一种新的雨水管理方式，对不同重现期下绿灰蓝基础设施布局模式的综合评价是雨洪管理实施决策的关键。雨水管理。本研究建立蓝绿协同评价模型，优化蓝绿基础设施布局。建立了评价指标体系与水文模型相结合的评价框架。选择雨水储存、峰值流量削减和生命周期成本作为评价指标。在此基础上，建立了绿色、蓝色、灰色、绿蓝、绿灰、蓝灰、绿灰蓝7种最佳场景。采用理想解相似度排序偏好技术（TOPSIS）方法来分析不同回报期下的这七种场景。研究结果表明：（1）排水基础设施组合布置时，与单一排水设施相比，峰值流量降低效果显着改善。(2) TOPSIS结果表明，当成本权重为0~0.35时，绿-灰和蓝-灰表现较好，而当成本权重为0.35-1时，绿-灰-蓝表现最好。(3)绿灰蓝一体化体系协同效应明显。本研究可为规划部门工作人员制定城市雨水管理策略提供支持。