查尔斯河浮动湿地试点项目丨美国波士顿丨Sasaki Associates,Inc.等

Charles River Floating Wetland Pilot Project | Sasaki Associates, Inc. + The Hideo Sasaki Foundation + Dr. McNamara Rome

项目陈述

PROJECT STATEMENT

查尔斯河浮动湿地试点项目旨在研究浮动处理湿地（FTW:Floating Treatment Wetlands）在改善城市受损水体中的应用潜力。研究聚焦三个相互关联的城市水环境问题：生境缺失、水质退化，以及公众对城市水体认知不足。项目通过将科学研究、设计实验与公众参与结合，验证了浮动湿地在提升水质、促进生物多样性和开展环境教育方面的综合价值。研究成果提出了一套具有技术依据的浮动湿地尺度计算方法，并表明该技术可成为景观建筑师应对城市水质问题、推动环境共治的重要工具。

The Charles River Floating Wetland Pilot Project investigates the application of Floating Treatment Wetlands (FTWs) as an innovative solution to improve degraded urban waters. This research addresses the linked challenges of missing habitat, degraded water quality, and impoverished public perception of urban waters. By combining scientific research, design experimentation, and public outreach, the project demonstrates how FTWs can enhance water quality, support biodiversity, and provide educational opportunities. The findings offer a defensible method for sizing FTWs and highlight their potential as an effective tool for landscape architects to address urban water quality challenges and foster environmental stewardship.

▲将浮动处理湿地（FTW）作为实践导向研究手段，用于改善退化的城市水体，并同时拓展环境教育机会。Application of Floating Treatment Wetlands (FTWs) as practice-based research to improve degraded urban waters and provide educational opportunities. © Sasaki and Hideo Sasaki Foundation

项目说明

PROJECT NARRATIVE

城市化进程深刻改变了城市水体系统。工程化排水体系、土地利用变化以及湿地消失，使许多水体承受较高的有机污染负荷，却缺乏自然净化路径。查尔斯河浮动湿地试点项目将浮动处理湿地（FTW）作为一种在水体内部直接布设的生态措施，用于提升城市水环境质量与生态功能。

浮动湿地是可漂浮的人工生态岛，种植本地湿地植物，可为水生生物提供栖息空间，并从水体中吸收营养盐。研究整合了波士顿、芝加哥和巴尔的摩三地多年的试点数据，重点评估了磷去除效果、生态结构变化以及社区参与情况。项目回应了一个关键难题：如何把短期实验室与中尺度试验结果，转化为可在真实水体中应用的工程方法。本次多年期实地研究据此建立了可用于水质目标导向设计的浮动湿地尺度计算体系。

主要研究发现包括：

磷去除效果：浮动湿地主要通过植物吸收实现磷去除。本研究中，通过收割地上部植物所实现的年均去除量为2.3 g·P/m²。按面积换算，1英亩浮动湿地可抵消约7–15英亩高密度城市开发带来的营养盐负荷，其效果与渗透型绿色基础设施相当，优于常规生物过滤系统与绿色屋顶。

生态效益：浮动湿地对生物群落结构产生了可测量的积极影响，包括本地小型猎物鱼类数量增加，以及大型浮游动物平均体型增大。这些变化与健康清水生态系统中常见的“自上而下”的藻类控制机制一致。

社区参与：项目同时作为环境教育平台开展实践教学活动，包括STEAM教学套件、皮划艇导览、青少年共创设计活动及现场实验。项目落实以来，已向当地学校发放408套六语种STEAM教学包，学生可亲手制作小型浮动湿地模型并学习河流生态知识。皮划艇考察提供沉浸式学习体验，青少年设计活动将社区反馈纳入后续规划。现场还安装了太阳能鱼类摄像系统，用于持续监测鱼群变化。

该研究为浮动湿地在城市环境中的规模化应用提供了技术依据，为景观建筑师在改善水质的同时提升生态与社会效益提供了新的工具路径。在查尔斯河下游这类本土湿地植被稀缺的水域，浮动湿地为小型鱼类提供关键栖息空间，为鸟类提供觅食场所，也为昆虫幼体提供食源，可作为城市水生态修复过程中的“生态跳板”。对公众而言，接触城市水空间已被证实有助于提升身心健康、降低健康风险。

未来研究仍需持续评估浮动湿地的长期表现、规模化可行性以及与综合绿色基础设施体系的协同方式。该项目通过整合科学研究、设计实践与公众参与，展示了浮动湿地将受损城市水体转变为健康生态系统与公众环境共治平台的潜力。

本项目不仅推动了生态工程领域的发展，也为创新型绿色基础设施在景观建筑中的整合应用提供了示范。研究结果进一步表明，将生态干预与社区参与结合，是实现可持续城市水环境治理的关键路径。

▲通过一次公益设计工作坊与多轮迭代优化，最终形成了一座面积约700平方英尺、中心开口、以单点锚固固定的浮岛方案。A pro-bono charrette and iterative design process led to a 700 SF island with a central opening secured by a single anchor. © Hideo Sasaki Foundation, Charles River Conservancy, Foth Engineering

▲从规划、设计到审批许可，湿地建设历时约20个月（2018年末至2020年6月），随后开展了为期三年的现场监测。Planning, designing, and permitting the wetland took roughly 20 months (late 2018 to June 2020), followed by three-year field monitoring. © Hideo Sasaki Foundation

▲湿地的设计与施工方案在推进过程中不断调整，综合回应审批要求、材料供应、结构工程、施工组织及成本约束等因素。The wetland’s design and installation evolved iteratively, shaped by permitting, materials, engineering, logistics, and cost constraints. © Charles River Conservancy

▲2020年6月，团队完成由24个模块单元组成的浮岛基体组装，并种植了3000株本土植物苗，涵盖19个物种。In June 2020, the team assembled the wetland matrix composed of 24 separate pieces and installed 3,000 native plugs representing 19 species. © Charles River Conservancy

▲组装完成后，浮动湿地被拖运至项目水域，完成锚固与浮力系统布设后正式安装就位。After assembly, the floating wetland was towed to the project site, anchored and buoyed for installation. © Charles River Conservancy

▲为避免冰冻破坏，每年冬季将浮动湿地转移至受保护水域停放，以保障其长期稳定运行。The FTW is moved to a protected location during winter to avoid ice damage, ensuring its longevity and functionality. © Charles River Conservancy

▲通过连续三年的实地研究，对浮动湿地在局部生态系统与水质改善方面的实际效果进行量化评估。Quantifying the floating wetland’s effect on the local ecology and water quality through a three-year field study. © Charles River Conservancy, Alyssa Stone/Northeastern University

▲现场监测重点包括通过植物根系系统实现的磷去除效果，以及湿地周边生态结构的变化情况。Field monitoring measures phosphorus removal via plant roots and documents local ecological changes in and around the floating wetland. © Charles River Conservancy, Alyssa Stone/Northeastern University

▲植物配置是项目成功的关键因素之一，既要保证景观观感，也要满足科研目标，因此优先选用本土物种体系。Plant selection was critical for success, ensuring a visually appealing island and supporting research goals with native species. © Charles River Conservancy, Alyssa Stone/Northeastern University, Dr. McNamara Rome

▲通过对收割植物样本的养分含量分析，测得磷去除效率为每年2.3 g·P/m²。Harvesting and analyzing nutrient content in plant material measured phosphorus removal at 2.3 g·P m⁻² year⁻¹. © Dr. McNamara Rome

▲在缺乏本土水生植被与栖息遮蔽条件的城市水域中，浮动湿地可提供关键生境，支持昆虫、鱼类与鸟类等多类生物群落。Floating wetlands create vital habitats, supporting diverse insect, fish, and bird life in urban waters lacking native surface plants or refuge. © Dr. McNamara Rome

▲研究整合了波士顿、巴尔的摩与芝加哥三地已稳定运行三年以上的试点级浮动湿地项目（面积40–280平方米）的监测数据。Findings from three well-established (>3 years) pilot-scale (40–280 m2) FTW installations in Boston, Baltimore, and Chicago were synthesized. © Dr. McNamara Rome

▲与对照水域相比，浮动湿地周边出现了明显生态变化，例如波士顿样点浮游动物数量下降、芝加哥样点本地小型鱼类数量上升。Observed ecological changes comparing FTWs to reference sites include zooplankton decrease in Boston, and native minnows increase in Chicago. © Dr. McNamara Rome

▲学生通过STEAM教学套件制作迷你浮动湿地模型，将课堂学习与真实科学实践结合；水下鱼类摄像系统在2024年累计记录超过1200小时影像。Students built mini floating wetlands with STEAM kits, linking classroom learning to real-world science, while fishcam recorded 1200+ hours in 2024. © Charles River Conservancy

▲在皮划艇导览活动中，当地青少年近距离观察浮动湿地系统，学习河流生态与水环境保护知识。Local youth engage with the floating wetland during a kayak tour, learning about river ecology and conservation efforts. © Charles River Conservancy

PROJECT NARRATIVE

The processes of urban development radically alter urban water bodies. Engineered drainage systems, land use changes, and loss of wetland habitat have resulted in water bodies with high levels of organic loading but limited natural pathways for processing pollutants. The Charles River Floating Wetland Pilot Project explores Floating Treatment Wetlands (FTWs) as an in-stream solution to improve water quality and ecological function in urban water bodies.

FTWs are artificial, self-buoyant islands that support native wetland plants, providing habitat and removing nutrients from the water column. Synthesizing data from three multi-year pilots in Boston, Chicago, and Baltimore, this study focuses on phosphorus removal, ecological changes, and community engagement. The research addresses the challenges of translating short-duration lab and mesocosm experiments into practical, field-scale applications. This multi-year field study provides a defensible method for sizing FTWs to achieve specific water quality goals.

Key findings include:

Phosphorus Removal: FTWs achieve phosphorus removal through plant uptake. In this study, mass removal through harvesting of aerial vegetation was 2.3 g·P m⁻² year⁻¹. One acre of FTW can offset nutrient loading from 7-15 acres of dense urban development, comparable to infiltration-based green infrastructure and more effective than biofiltration methods and green roofs.

Ecological Benefits: FTWs create measurable changes in biotic structure. Localized changes include increased abundance of native prey fish and increased mean body among large-bodied zooplankton. These changes are consistent with top-down control of algal biomass observed in healthy clear-water ecosystems.

Community Engagement: The project serves as a platform for hands-on environmental education through STEAM kits, kayak tours, youth design sessions, and on-site experiments. Since its installation, 408 STEAM kits with informational materials in six languages have been deployed in local schools, enabling students to build their mini-floating wetlands and learn about river ecology. Kayak tours provide immersive learning experiences, while youth design sessions incorporate community feedback into future FTW planning. A solar-powered fish camera was installed to monitor fish populations.

The research provides a basis for scaling FTWs in urban environments, offering landscape architects a new tool to address water quality challenges while enhancing ecological and social benefits. Along the Lower Charles River, where native wetland vegetation is scarce, FTWs provide critical habitat for small fish, foraging grounds for birds, and food sources for larval insects, and may serve as stepping stones in recovering urban waterways. For humans, access to urban blue spaces has been linked to improved well-being and reduced health risks.

Future research must assess FTWs’ long-term impacts, scalability, and integration with broader green infrastructure. By merging science, design, and public outreach, the project demonstrates FTW’s potential to transform degraded urban waters into vibrant, healthy ecosystems and environmental stewardship.

This project not only advances the field of ecological engineering but also provides a model for integrating innovative green infrastructure into landscape architecture. The findings highlight the importance of combining ecological interventions with community engagement for sustainable urban water management.