北京永兴河绿道突破了常规的城市防洪工程模式，将季节性的城市排水通道变成了具有弹性的绿色海绵，以保留和净化城市雨洪，同时创造了一个生态健康的、生产性的、促进社区建设的绿色基础设施。去除混凝土边坡，建造湿地，通过挖填方平衡来创建多孔地形海绵，形成多样化的栖息地，并布局活动场所以满足当地居民的需求。该项目展示了景观作为绿色基础设施的多功能综合设计，提供调节水文环境，支持本地生物多样性和创造社区活力等综合生态系统服务。

Standing in marked contrast to the conventional approach to flood-control engineering, the Beijing Yongxing River Greenway project has transformed a seasonal urban drainage into a resilient “green sponge” that retains and filters stormwater, while also creating an ecologically sound, productive green infrastructure that is helping to build community. Concrete berms were removed and wetlands were constructed, porous landforms were built with earth-balance cut and fill techniques to create diverse habitats and recreation areas were built to meet the needs of local communities. This project showcases landscape as a kind of green infrastructure that provides holistic ecosystem services, including regulating local hydrology and supporting native biodiversity, while also building community vitality.

▼项目概览，project preview ©土人设计

永兴河原名天堂河，其南段连接着北京大兴国际机场，长37公里，具有300多平方公里的集水区，是区域内主要的雨洪通道。自1960年代以来就已被渠化，不断被挖开并用混凝土硬化。河岸局部有成排的柳树和杨树。永兴河是季节性河流，一年中大部分时间都没有自然径流，但是河道被沿河的工厂和居民点排出来的污水所污染，在雨季经常被洪水淹没。随着沿河建筑面积的扩大和不透水铺装的增加，使得河道亟需提升它的防洪能力。同时，沿河的新社区也迫切需要一条干净的河道和更多的绿色休闲空间。幸运的是，土地利用规划已在河道西侧预留了约100米的范围作为公共绿地，以便有足够的空间来排水。河道改造工程覆盖永兴河上游17公里，总面积150公顷。

项目面临的挑战是多方面的： 1. 如何突破传统的水利工程解决方案，即砍掉河岸上的现状树木，加宽河道并覆上混凝土等做法，用生态的手法构建一个生态化的雨洪管理系统。 2.如何使新的季节性排水系统具有水弹性，能在雨季容纳100年一遇的洪水，同时创造一个宜人的公共空间来满足当地社区居民日常的休憩需求。 3.如何在如此大规模的景观建造过程中尽可能降低造价和技术难度，并且使长期的维护成本降低。

面对这些挑战，景观设计师被寄予希望去利用这个改造排水系统的机会，设计一个集雨水管理，栖息地修复、公共绿地设计为一体的综合绿色基础设施工程。

▼鸟瞰，aerial view ©土人设计

Traversing the edge of the new Beijing Daxing Capital Airport, south of Beijing’s city center, the 37-km-long Yongxing River — originally called the Tiantang (Paradise) River — drains stormwater from 300-plus [square kilometers?]. Since the 1960s, the river had been channelized, and then was continually dredged and lined with concrete. Some sections of the river bank are lined with willow and poplar trees. Dry most of the year, the riverbed served as a sump for pollution from neighboring factories and settlements, and flooded during the monsoon season [spreading pollutants throughout the surrounding area, or pushing pollutants downstream?]. As the surrounding land was developed and the area along the river covered with impermeable surface expanded, increasing the river’s flood-retention capacity became critical. At the same time, the residents of new communities along the river began calling for a clean river and more green space for recreation. Fortunately, a roughly 100-meter swath along the river had been set aside as public green space in order to accommodate the need for increased drainage. A drainage improvement project was planned for the uppermost 17-km. reach of the Yongxing River, covering a total area of 150 hectares.

The challenges of the reconstruction project were multi-faceted:

1.How to offer an alternative to the conventional engineering approach of widening the channel, lining it with concrete and removing the existing decades-old trees on the riverbank, and instead create an ecologically sound constructed drainage; 2.How to ensure that the new seasonal drainage will be able to accommodate a 100-year flood during the monsoon season, while simultaneously creating a pleasant public space to meet local communities’ needs for year-round recreational opportunities; 3.How to ensure that the construction process would be low-cost and technically straightforward at such a massive scale, and require minimal maintenance over the long term.

▼公园入口，entrance ©土人设计

为了将最初的防洪项目转变为具有整体生态系统服务功效的生态基础设施，设计中采取了以下主要策略：

1. 保护所有现状树木并将其整合到场地设计中。它们主要分布在现状河岸上。

2. 用挖填方艺术，创建海绵河流廊道：取代原有的将水与土地分开的方式，创建多孔地貌以解决水与土地之间的边界问题。通过现场挖填方，形成河床上的浅水洼地，主河道中的小岛以及河道沿岸的漫滩区。拆除原有河岸两侧的混凝土，并将材料回收再利用于小岛和地形的基础建造。同时，沿着线性绿色空间的边缘构造了一系列生物过滤带，以收集和过滤来自城市街道上的径流。

The Daxing Planning Bureau’s need for what was initially conceived of as a traditional flood-control project provided an opportunity to develop a more holistic green-infrastructure design, which combines storm water management, habitat restoration and public green space. The following strategies were at the core of that effort:

1. Preserve the existing trees: All existing trees, which are primarily distributed on the former channel bank, were preserved and integrated into the site plan.

2. Use cut and fill to create a sponge riparian corridor: Instead of separating water from the land, a porous landform was created to resolve the boundary between water and land. Through cut and fill on site, land forms of pits and mounds on the land, islands in the main drainage, and shallow area along the channels edge were created; concrete lining along the channel was removed and materials were recycled on site to build the base of islands and mounds. A series of bio-swales were constructed along the edge of the green space to catch and filter urban runoff from the streets.

▼灌木替代了原有的混凝土护坡，the former concrete slopes are now covered with willow seedlings and false indigo bush ©土人设计

3. 运用本地植被和生产性植物：根据地形和水分条件的差异形成了不同的生境，从而种植不同类型的植物。 河道的斜坡上覆盖着柳树幼苗和紫穗槐，这些灌木替代了原有的混凝土护坡，以防止土壤被侵蚀。在主河道和生物过滤带种植了各种类型的湿地植物。山丘上覆盖着抗旱果树，其中包括在北京地区广泛种植的柿树和山楂树。地面普遍覆盖着能自我繁衍的野花地被，而沿着人行步道和活动空间都种植遮荫树。

3. Emphasize native and productive vegetation: Various types of vegetation were introduced to create diverse habitats. After the concrete was removed, the slope of the drainage was covered with willow seedlings and false indigo bush to prevent erosion; various kinds of wetland plants were planted in the drainage and bio-swales; the mounds were covered with drought-resistant fruit trees including Kaki, Crab Apple and Hawthorn, which are widely grown in Beijing area; and much of the ground was planted with self-reproductive meadows. Canopy trees were planted along the pedestrian paths and other places where people congregate.

▼在主河道和生物过滤带种植了各种类型的湿地植物，various kinds of wetland plants were planted in the drainage and bio-swales ©土人设计

▼地面普遍覆盖着能自我繁衍的野花地被， much of the ground was planted with self-reproductive meadows ©土人设计

▼沿着人行步道和活动空间都种植遮荫树，canopy trees were planted along the pedestrian paths and other places where people congregate ©土人设计

4. 活动场所和步道系统：人行天桥的设计旨在将被道路分割的绿地连接起来，而丰富的人行步道系统为游览者提供浸入式的体验通道。此外，儿童游乐场、运动场和各种大小的广场都被整合到了绿道之中，而由玻璃钢制成的形状相同但颜色不同的亭子分布在景观中，占据一些关键节点，以便游客观景、休憩和聚会，并使其成为景观中靓丽焦点。

4.Create gathering spots and a pedestrian network: A skywalk is designed to connect all sections of the greenway that would otherwise be interrupted by road crossings; a network of pedestrian paths provides access among the diverse habitats created in the green space; children’s playgrounds, sports ground and plazas of various sizes are integrated into the greenway; a series of pavilions, with subtle variations in color, are strategically placed throughout the greenway’s matrix to allow visitors to experience the landscape.

▼观景亭子，viewing pavilions ©土人设计

▼人行步道， pedestrian paths ©土人设计

在大约三年的时间里，我们设计了永兴河的17公里，并以1.7亿这个相对较低的实施费用完成了4公里长的海绵型雨洪廊道。重建后的城市防洪排涝系统是一个能应对洪水泛滥的弹性海绵走廊。乡土的植被替代了以前的灰色水泥护坡；受污染的城市径流通过生物过滤系统得到净化；土丘上的生产性果树春天开花，秋天结果，给社区居民带来了不同季节的惊喜；修建了超过13.5公里的步行道，为当地居民提供了一个可以每天跑步的地方；沿绿道还建有便于通勤的自行车道；儿童游乐场和运动场是当地居民游玩的热门场所；设计的五个亭子作为景观中供人们休憩的艺术装置，吸引着人们在里面聚会，聊天和欣赏美景。永兴河绿道已成为这个城市最受欢迎的公共场所之一，并经常被当地新闻所报道。

▼永兴河绿道已成为这个城市最受欢迎的公共场所之一 ©土人设计 the greenway is now one of most popular public spaces in the city and is frequently covered in the local news

In about three years, we designed 17 kilometers of the Yongxing River Greenway and built 4 kilometers of it at a comparatively low budget 170 million RMB ($24 million USD). The reconstructed urban drainage is a flood ready resilient sponge corridor. Native vegetation has replaced the former gray concrete slope. Contaminated urban runoff is now filtered and water cleaned by the bio-swale system. The fruit trees on the mounds give a sense of seasonal excitement to the urban community, with abundant flowers in the spring and fruits in the fall. Over 13.5 kilometers of pedestrian paths were built that are used by local community members for jogging every day; a bicycle path was built along the greenway; children’s playgrounds and exercise areas are popular places for local residents to congregate; five pavilions serve as resting spots as well as landscape-art installations that attract people to linger and enjoy the views. The greenway is now one of most popular public spaces in the city and is frequently covered in the local news.

▼四季不同的景观体验，the landscape experiences vary in different seasons ©土人设计

项目名称：北京市永兴河绿道 项目地点：北京大兴区 项目面积：150公顷 设计：土人设计Turenscape 设计时间：2013年12月-2014年4月 建成时间：2019年5月 委托方：北京市政府大兴规划局