滨海典型区地下水对海绵城市建设的响应与约束及其LID设施优化设计

Sponge urban construction is an important measure for slowing down urban waterlogging, improving usage of rainwater resources, and optimizing the ecological environment. The buried conditions of groundwater often have some constraints on the construction of sponge city, so it is necessary to clarify the response mechanism and constraints of groundwater in the area to sponge city construction. Based on data collection, actual investigation, indoor experiments and computer simulation techniques, this research aims to clarify the dynamic process of groundwater in the region, and to conduct a qualitative analysis of the hydrological cycle process in sponge city from the perspective of water equilibrium. The response mechanism and control conditions of groundwater to sponge city construction are put forward. In response to potential problems such as high water table congestion and particulate matter blocking sponge in rainwater during the rain flood supply process, a new compound function LID（Low Impact Development） facility that is conducive to the efficient use of rainwater is designed and physical simulation and optimization is carried out. It provides theoretical basis, technical means and practical basis for the construction of sponge city.

海绵城市建设是减缓城市内涝、提高雨水资源利用、优化生态环境的重要举措，而滨海典型区是复杂的水文、生态交错带，受限于滨海地区特有的地理和生态环境，地下水的埋藏条件往往会对海绵城市的建设产生一些约束，因此理清该区域地下水对海绵城市建设的响应机制与约束条件十分必要。本研究以资料收集、实际调查为基础，以室内实验和计算机模拟技术为手段，以理清区域地下水动态过程为目标，从水均衡角度出发对海绵城市水文循环过程进行定性分析，提出地下水对海绵城市建设的响应机制与约束控制条件；针对雨洪补给过程中可能带来的地下水位壅高、雨水中颗粒物堵塞海绵体等潜在问题，设计利于雨水高效利用的新型复合功能LID（Low Impact Development）设施并进行物理模拟及优化，为海绵城市建设提供理论基础、技术手段和实践依据。

本项目立足于海绵城市相关研究，首先从区域尺度出发，研究海绵城市建设影响因素及优化思路，完成了基于meta分析的中国不同地理环境下海绵城市建设综合效益评估，在北方地区建设从年径流总量控制率及SS去除率的提升来说效益值最高，两个指标权重值分别为25.5%和21.4%，并且基于因子分析和GIS地理统计方法研究天津市海绵城市空间格局并进行优化；然后，从场地或单体设施的尺度，完成了LID低影响开发设施的设计，建立基于SWMM-Modflow耦合数值模拟模型，结合解析法得到场次雨洪回补地下水水量，分析地下水动态对海绵城市的响应机制，从而设计基于复合型LID设施的城市雨水径流地下水回补系统，结合Flow-3D数值模型优化下凹式绿地设施参数等。以上研究成果将为我国海绵城市规划设计提供指导，根据滨海典型地区地理环境、经济、社会因素在宏观层面上优化海绵城市规范、规模和布局，同时细化LID设施本身设计，为国内外相关工作的优化、改进和效益评价等提供宝贵经验和参考。