让水流慢下来：六盘水明湖湿地公园SLOW DOWN: LIUPANSHUI MINGHU WETLAND PARK

项目位置：中国贵州省六盘水市

项目规模：90ha

设计公司：土人景观

获奖信息：2014美国景观设计师协会设计荣誉奖

2013中国环境艺术设计金奖

Location: Liupanshui City, Guizhou Province, China

Size: 90ha

Design Firm: Turenscape

Awards:2014 ASLA Honor Award in General Design

2013 Gold Medal in Environmental Art and Design of China

明湖湿地公园位于贵州省西部的六盘水市，沿水城河而建。该项目旨在修复河道生态、拓展城市绿地公共空间，同时提升城市河漫滩土地的价值，让湿地成为该市生态基础设施的一部分，并为整个地区的生态服务。经过三年多的设计和修建，明湖湿地公园使原来被污染和渠化的河道恢复了原有的生机，并种植了各类乡土植被，成为整个城市健康生态系统的重要保障。

挑战与目标

六盘水是一个在20世纪60年代中期建立起来的工业城市，以其凉爽的高原气候而著称，城市被石灰岩的山丘环抱，水城河穿城而过。城市人口密集，在60km2的土地上，居住了约60万的人口。作为改善环境的重要举措之一，市政府委托景观设计师制订一个整体方案，以应对城市所面临的多项挑战，包括以下几个方面。

（1）水污染：作为中国重要的重工业城市之一，六盘水以煤炭、钢铁和水泥行业为主导产业。因此，民众长期受到空气和水污染的困扰。数十年来，从工业烟囱排出的污浊空气中的颗粒物沉积在周边的山坡上，并随着雨水径流被带入河流，来自山坡上农田的化学肥料以及散落的居民点的生活污水也一同随地表雨水径流汇入水体。

（2）洪水和雨涝：由于坐落在山谷之中，该城市在雨季容易受到洪水和涝灾的危害，而由于多孔石灰岩地质，到了旱季又易遭受旱灾。所以，季节性雨水的滞蓄和利用非常重要。

（3）母亲河的修复：20世纪70年代，为了解决泛溢和洪水问题，水城河被水泥渠化。从此，原来蜿蜒曲折的母亲河变成了混凝土结构的、死气沉沉的丑陋河沟，其拦截洪水及环境修复的功能也丧失殆尽。同时，渠化的河道将上游的雨水直泄入下游河道，引发了下游更为严重的洪水问题。

（4）创建公共空间：城市人口激增导致城市休闲和绿色空间的不足。曾经作为城市福音的水系统已经变成城市废弃的后杂院、垃圾场和危险的死角。因此，在人口密集的社区与生态修复后的绿色空间之间建立人行通道极其必要。

这一设计的关键在于减缓来自山坡的水流，建造以自然水过程为核心的生态基础设施，加强雨洪管理，使水成为重建健康生态系统的活化剂并提供自然和文化服务，使这个工业城市变为宜居城市。

设计方案

六盘水明湖湿地公园项目占地90ha，是该城市规划的综合生态基础设施中首要且至关重要的组成部分。

为了构建完整的生态基础设施，景观设计师同时关注水城河流域和城市本体两方面。首先，河流串联起现存的溪流、坑塘、湿地和低洼地，形成一系列蓄水池和不同承载力的净化湿地，构建了一个完整的雨水管理和生态净化系统，一个绿色海绵体系。这一方法不仅最大限度地减少了城市的雨涝危害，还保证雨季过后仍然有水流不断。第二，拆除渠化河渠的混凝土河堤，重建自然河岸，使河岸恢复生机，使河流的自净能力大大提高。第三，建造包含人行道和自行车道的连续公共空间，增加通往河边的连接通道。这些绿道将城市休憩和生态空间一体化。最后，项目将滨水区开发和河道整治结合在一起。生态基础设施促进了六盘水的城市更新，提高了土地价值，增强了城市活力。

作为六盘水生态基础设施的主要项目之一，明湖湿地公园位于水城河上游区域，设计师面对的是被渠化的河道、被垃圾和污水恶化的湿地区域、废弃的鱼池及管理不善的山坡地，垃圾遍地、污水横流。作为生态基础设施的示范项目，设计的第一步是重建生态健康的土地生命系统，包括改善雨水水质、恢复原生栖息地、建造通向高品质开放空间的游憩道，以促进整个城市的发展。为实现这些目标，具体的工程实施策略包括以下几个方面：

（1）拆除混凝土河堤，恢复滨水生态地带。为各种挺水、浮水和沉水植物提供生境。沿河建造曝气低堰，以增加水体含氧量，促进富营养化的水体被生物所净化。

（2）建造梯田湿地和坡塘系统，以削减洪峰流量，调节季节性雨水。梯田的灵感来源于当地的造田技术，通过拦截和保留水分，使陡峭的坡地成为丰产的土地。它们的方位、形式、深度都依据地质因素和水流分析而设定。根据不同的水质和土壤环境，种植乡土植被（主要采用播种的方式）。这些梯田状栖息地减缓了水流，同时水中过盛的营养物质成为微生物和植物生长所需的养分来源，从而加快了水体营养物质的去除。

（3）人行道和自行车道沿水系铺展，在湿地梯田之间形成网络。大量座椅、凉亭和观光塔的休息平台融入自然系统中，为游客提供学习、娱乐和景观审美体验，并设计了一个环境解说系统以帮助游客理解这些地方的自然和文化含义。场地中最具标志性的建筑物是暖色的彩虹桥，它与当地常见的凉爽湿润天气形成对比。这座长堤连接中心湿地（湖）的三岸，营造了散步及聚会的舒适环境。这里迅速成为备受当地民众和远近游客喜爱的社交和休闲场所。

结论

得益于这些景观技术，衰退的水系统和城市周边的废弃地被成功地转变为高效能、低维护的“城市前厅”。它巧妙地调蓄雨水、净化地表污水、修复原生栖息地，并吸引了广大的居民和游客。2013年明湖湿地公园被官方指定为“中国国家级湿地公园”。

This project is situated in Liupanshui City, along the Shuicheng River. The scope of the task includes ecological restoration of the river, the upgrading of urban open space system, as well as increasing the value of urban waterfront land. The landscape along the Shuicheng River is therefore recovered as an ecological infrastructure providing ecological services to the region. After nearly three years of phase-one design and construction, the once highly polluted and channelized waterway of Liupanshui City has been transformed back into the lifeline of the city through the use of vegetation and natural embankments.

Challenges and Objectives

Liupanshui, known for its cool plateau climate, is an industrial city built in mid 1960s in a valley surrounded by limestone hills, with Shuicheng River running through it. With an area of 60 square kilometers, the city is densely inhabited by a population of 0.6 million. As an element of a major campaign of environmental improvement, the city government commissioned landscape architect to develop a holistic strategy to address multiple serious problems as follows.

(1) Water pollution: As one of the major heavy industrial cities built during the cold war period, Liupanshui has been dominated by coal, steel and cement industries. Consequently, the citizens have suffered with the resulting air and water pollution for a long time. From the industrial chimneys, decades of air pollution deposits fell onto the surrounding slopes and washed into the river along with the storm water that also carries the chemical fertilizer runoffs from the farm land on the slopes and sewage from the scattered settlements on the slope;

(2) Flood and storm water inundation: Situated in the valley, the city is subject to floods and storm water inundation during the monsoon season, but also severe drought in the dry season due to the porous limestone geology;

(3) Recovery of the mother river: Channelization of the Shuicheng River was carried out in the 1970s as a solution to inundation and flooding. The channel transmitted the storm water from upstream but caused even more severe flooding problems downstream. Hence, the former meandering mother river became an ugly concrete, lifeless ditch and its capacity for flood retention and environmental remediation was totally lost;

(4) Creation of public space: Recreation and green spaces are inadequate due to the population explosion in the city. The water system that was once a blessing to the city has become a deserted backyard, garbage dump and the dangerous backside of the city. Pedestrian access to a restored green space system is badly needed in such a densely populated community.

The strategy is to slow the flow of water from the hillside slopes and create a water-based ecological infrastructure that will retain and remediate the storm water, and make water an active agent in regenerating a healthy ecosystem to provide natural and cultural services that transform the industrial city into a livable human habitat.

Design Strategies

The submitted Liupanshui Minghu Wetland Park project, 90 hectares (222 acres) in size, is the first phase and a major part of the comprehensive ecological infrastructure project planned for the city by the landscape architect.For the overall ecological infrastructure, the landscape architect focused both on the Shuicheng River drainage basin and the city. Firstly, existing streams, wetlands, and low-lying land are all integrated into a storm water management and ecological purification system linked by the river, forming a series of water retention ponds and purification wetlands with different capacities. This approach not only minimizes urban flooding but also increases the base flow to sustain river water flow after the rainy season. Secondly, the concrete embankment of the channelized river was removed. A natural riverbank was restored to revitalize the riparian ecology and maximize the river's self-purification capacity. Thirdly, continuous public spaces were created to contain pedestrian and bicycle paths increasing access to the riverfront. These corridors integrate the urban recreation and ecological spaces. Lastly, the project combines waterfront development and river restoration. The ecological infrastructure catalyzes urban renewal efforts in Liupanshui, significantly increases land values, and enhances urban vitality.

As one of the major projects included in the ecological infrastructure of Liupanshui, the Minghu Wetland Park features ecological restoration of the upper stream section of the channelized river. Minghu Wetland Park was created on a site composed of deteriorated wetland patches, abandoned fish ponds and strips of mismanaged corn fields. Its pre-development condition was dominated by garbage dumps and polluted water. As a demonstration of the ecological infrastructure project, this first phase project was designed using all of the tactics for rebuilding ecological health leading to the recovery of biodiversity and native habitat, retention and water quality improvement of storm water, and public access to high quality open space, and finally a catalyst for urban development. The specific park elements that are achieve these objectives are listed below.

(1) The concrete river embankment was removed to create two ecological zones. One encourages native vegetation to grow within the flood zone and the other establishes conditions for emergent vegetation in the riverbed. Aerating cascades were created along the river to add oxygen that fosters bio-remediation of the nutrient-rich water.

(2) Terraced wetlands and retention ponds were created to reduce peak water flow and regulate the seasonal rainwater. The terraces are inspired by the local farming techniques that catch and retain water and transform steep slopes into productive fields. Their positions, forms and depths were based on geographic information and a water flow analysis. Native vegetation was planted (mostly sown) to establish associations adapted to the various water and soil conditions. These terraced habitats slow the flow of water and speed nutrient removal from the water by microorganism and plant species that use excess nutrients as resources for rapid growth.

(3) Pedestrian paths and bicycle routes are overlaid on the green spaces along the waterways and form a circuit around and between the wetland terraces. Resting platforms with abundant seats, pavilions and a viewing tower are integrated into the designed natural system for universal access. This fosters learning, recreational and aesthetic landscape experiences. An environmental interpretation system was designed to help visitors understand the natural and cultural meaning of the places. Clearly, the most iconic built artifact is a warm-colored rainbow bridge, in contrast with the frequently cool and damp climate. This causeway connects three sides of the central wetland (lake), creating unforgettable walking and gathering places. These have quickly become favored social and recreational environments of the citizens and attract visitors from near and far.

Conclusion

Through these landscape techniques, the deteriorated water system and peri-urban wasteland has been successfully transformed into a high-performance and low maintenance municipal front yard. It beautifully regulates storm water, cleans contaminated water, restores native habitats for biodiversity, and attracts residents and tourists. It was officially designated as a National Wetland Park in China in 2013.