中国园林·刊首语(2023-02) | 王向荣:自然城市
《中国园林》
Vol. 39 2023-02 | 326
本期主题:风景园林与健康中国
自然城市
Natural City
不久前在一本杂志上看到一篇文章,介绍一座为携带宠物的旅客设计的旅馆。在文中的近10幅平面图、轴测图和分析图中,我没有见到任何植物,10余张建成照片呈现的是一个完全人工化的混凝土世界,除了远方(应该不在设计地块内)零星的树木外,建筑周边、庭院及室内几乎看不到有生命的物质。我不知道住在这里的客人和宠物会有怎样的感受,更不知宠物狗在哪儿能找到撒尿所依托的树木。好在这只是一家供旅人歇脚的酒店,如果我们几十年居住或工作的建筑甚至生活的社区也是如此,身边看不见绿色,听不见鸟鸣蝉噪,感受不到季相的变化,人和宠物的身心会受到怎样的伤害?
人类是自然界的产物,在荒野中经历了数百万年的生息、繁衍和进化,才逐步有能力改造自然、发展农业、建设定居家园,并不断改善栖居环境。与漫长的采集和狩猎时期相比,人类仅有万年左右的定居历史,而大规模工业化至今不过200年的时间。之后越来越多的人开始生活在人工建造的城市之中,人与环境的关系发生了根本的改变。然而人类历史99%以上的时间都以采集和狩猎为生,人体的组织和功能就是在不断适应自然环境的进化过程中形成的。人类对自然深度依赖的基因一直沉积至今,只有生活在适宜的环境中,人体脏腑和气血阴阳才能达到平衡协调。离开自然,人类无法健康生存。
健康的本质就是一种和谐与平衡的状态,和谐体现了人与自然之间最健康和最良好的关系,融于自然的生活是保证人类身心健康的根本途径。自工业革命以来,人类具有了改造自然、建设家园的“无限”能力,在建造了高效和便利城市的同时,也将工业化之前人与自然相互依存的生活环境变成了人与自然相互疏离的人工化城市,造成了人与自然关系的失衡。
为了重新构建起人与自然本应具有的和谐关系,让人在享用城市高度物质文明成果的同时,仍然能够亲近自然,生活在健康宜居的环境之中,一些思想家、学者和规划师相继提出了理想的城市发展模式,如田园城市、卫星城市、有机城市、宜居城市、园林城市、生态城市、山水城市、森林城市、韧性城市、海绵城市,等等。尽管这些城市发展理论的名称不同,提出的背景、针对的问题和实施的策略亦有差异,但核心都是以自然为依托,构建城市自然生态系统与社会生态系统的整体协调关系。所以工业化以来提出的绝大多数理想城市模型的核心和基础都可以归结为“自然城市”。
图1 许多理想的城市发展模式的基础都可以归为自然城市
自然城市是紧凑之城。只有友好地对待自然,自然才能更好地反哺人类。那种松散、缺少密度、占用大量自然空间并无限蔓延的城市,或许可以随处见绿,但是从更大尺度上看,这样的城市却是对自然资源极大的破坏。自然城市一定是一座节地建造的紧凑型城市,是集约利用土地,将人工建造控制在合理的范围,既能把更多的区域留给自然,又能实现城市在功能、规模和结构上紧凑高效的城市。这样的城市将以自然中的栖居、宜人的尺度、充满活力的街区、丰富的公共空间、低耗能的交通等带来舒适健康的城市生活。
图2 紧凑型城市香港,将人工建造控制在一定的范围内,把更多的区域留给自然(王向荣摄)
自然城市是地域之城,是基于自然地理、人文地理及气候条件建造的城市。自然城市不是附着于土地之上的人工建造物的集合体,而是生长于自然之中的城市。自然城市强调的是向自然学习,是一种与自然和谐共生的城市建设,是依据当地自然条件、密切融入地理环境的城市。自然城市的规划和建设绝不会与自然较劲角力,而是依托地理、尊重自然、顺应自然、亲近自然、延续历史与文化、引导健康生活的城市规划和建设。由于不同区域具有不同的地理环境、气候条件和历史文化,所以自然城市一定是地域性的城市,也是多样化和个性化的城市。
图3 重庆云阳,一座依托地理环境而建的山水之城(孙国栋摄)
自然城市是生态之城。自然城市是遵循自然进程、追求自然系统完整性并按生态学的原理规划和建设的城市,拥有将城市中的自然与区域中的山水林田连为一体的、结构完整且功能复合的自然生态网络。自然城市中的自然类型多样、功能复杂,它们构成了维持城市机体良性运转、具有充分自然属性和强大韧性的生态基础设施,承担净化空气、缓解热岛、调节湿度、防风固土、涵养水源、管理地表水、维系生境和栖息地、维护生物多样性等生态功能,支撑起人工建造与自然之间动态的平衡与和谐,实现安全、健康、宜居和优美的人居环境。
图4 斯德哥尔摩哈默比湖城(Hammarby Sjöstad),水系、湿地、林地、街区公园、庭院及屋顶绿化构成了新城的生态系统(王向荣摄)
自然城市是有机之城。作为紧凑型城市,城市组团内部的非硬化地表面积有限,但是自然城市中的自然空间均达到或超过了城市应有的自然空间的最小值,实现的潜力在于将城市中的灰色基础设施绿色化。部分建筑和基础设施的表皮可被植物覆盖,硬化的地表可以透水或将水收集到雨水湿地中,渠化的河道可进行近自然化的生态修复。由于城市的地表面积加上建筑和基础设施表皮面积的总和远远大于城市的投影面积,自然城市中自然空间的面积可以接近甚至大于城市的投影面积。由这些自然空间组成的自然系统将城市中一项项单一的工程整合在一起,使得城市成为一座有生命的、具有自我调节能力的有机城市。
图5 通过绿地网络、绿色建筑及灰色基础设施绿色化的建设,以及提高绿地的自然属性等措施,新加坡成为一座有机之城,照片为新加坡科技与设计大学(王向荣摄)
自然城市是共享之城。自然城市的生态网络也是社会生活网络,是城市重要的公共空间系统。网络延伸到城外的山水林田,将自然风景引入城市,还通过廊道和微廊道渗透到城市街区,使开放的绿地具备方便的可达性、连通性和共享性,满足市民休憩、观光、娱乐、运动、交流、教育、步行和自行车通勤等多元丰富的使用需求。有条件的绿地,如公园、社区、校园和建筑屋顶等都能成为生产性的花园,不仅可以带来蔬菜瓜果等食物的生产,还能让居民更直接地亲近自然、创造融洽的邻里交往机会,让孩子们接受更多的自然教育,同时让市民参与到城市自然的管理之中。
图6 美国印第安纳波利斯中心运河廊道是城市中集休闲、观光、慢行、生活、文化、商业、居住为一体的共享空间(王向荣摄)
自然城市是诗意之城。人类不仅遗传了无法离开自然而生存的基因,也遗传了欣赏自然的审美偏好。自古以来,中国人就将情感与心灵寄托于自然之中,山水成为中国人的精神家园。自然城市传承了城市固有的山水结构与文化,拓展了城市生态空间,完善了生态系统,提升了生态质量,让市民在窗前能看见绿色,在室外可触及自然,沿着廊道可抵达区域中的山水田园。自然城市是在满足城市综合复杂功能的基础上,尊重自然过程并按中国特有的风景营建思想规划和建设的城市,是将自然转化为画意并上升为诗境的城市,是能寄托情感、承载生活并表达中国人特有审美方式的城市。
图7 杭州,一座充满自然气息和文化氛围的诗意之城(张圣东摄)
人类创造了城市,获得了文明的巨大进步,但也造成了自身与自然的疏离。与自然协调共生是人类健康生活的基础,建设自然城市是实现城市中人与自然和谐平衡、让“天地位焉,万物育焉”的根本之道。
I read an article in a magazine not long ago about a hotel designed for travelers with pets. In the nearly 10 floor plans, axonometric drawings, and analysis drawings in this article, I didn't see any plants. The more than 10 photos of the completed construction presented a completely artificial concrete world, except for few scattered trees in the distant place (which should not be in the design plot), and there was almost no living matter around the building, in the courtyard, or in the interior. I don't know how the guests and pets living here would feel, let alone where the dog could find a tree to pee on. Fortunately, this is just a hotel for travelers to rest. If the communities we live or work in for decades are all like this, not seeing the green around us, not hearing the singing of birds and cicadas, or not feeling the changes of seasons, how will our and pets' bodies and minds be harmed?
Human beings are the products of nature. After millions of years of living, reproducing, and evolving in the wilderness, people gradually have the ability to transform nature, develop agriculture, build settlements, and continuously improve the living environment. Compared with the long period of gathering and hunting, human beings only have a history of settlement of about 10,000 years, and large-scale industrialization has only been in recent 200 years. Since then, more and more people began to live in artificially built cities, and the relationship between human and the environment has undergone fundamental changes. However, people have lived more than 99% of human history in gathering and hunting, and the tissues and functions of human body have been formed during the evolutionary process of constantly adapting to the natural environment. The genes of human beings' deep dependence on nature have been deposited until now. Only by living in a suitable environment can the human viscera, vital energy, blood, yin and yang be balanced and coordinated. Human beings cannot survive without nature.
The essence of health is a state of harmony and balance. Harmony embodies the healthiest and best relationship between human and nature. Living in harmony with nature is the fundamental way to ensure human physical and mental health. Since the industrial revolution, human beings have had the "infinite" ability to transform nature and build homes. While building efficient and convenient cities, they have also transformed the interdependent living environment between human and nature before industrialization into artificial cities where human and nature are alienated from each other, causing the imbalance in the relationship between human and nature.
In order to rebuild the harmonious relationship between human and nature, so that people can enjoy the achievements of the city's high material civilization while still being close to nature and living in a healthy and livable environment, some thinkers, scholars, and planners have proposed ideal urban development models, such as garden city, satellite city, organic city, livable city, ecological city, landscape city, forest city, resilient city, sponge city, etc. Although these urban development theories have different names, backgrounds, targeted problems and implementation strategies, the core is to rely on nature to build an overall coordinated relationship between urban natural ecosystems and social ecosystems. Therefore, the core and foundation of most ideal city models proposed since industrialization can be attributed to "natural city".
The natural city is a compact city. Only by treating nature in a friendly way can nature better feed back to human beings. People in a city that is loose, lacks density, occupies a lot of natural space, and spreads infinitely may be able to see green everywhere, but on a larger scale, such a city is a great damage to natural resources. A natural city must be a compact city built in a land-saving manner. It is an intensive use of land and control of artificial construction within a reasonable range. It can not only leave more areas for nature, but also realize the compactness and efficiency of city in terms of function, scale, and structure. Such a city will bring comfortable and healthy urban life with natural habitat, pleasant scale, vibrant neighborhoods, rich public space, and low energy consumption transportation.
The natural city is a regional city built on the basis of natural geography, human geography and climatic conditions. The natural city is not a collection of man-made structures attached to the land, but a city growing in nature. The natural city emphasizes learning from nature. It is a kind of urban construction that coexists harmoniously with nature. It is a city that is closely integrated into the geographical environment based on local natural conditions. The planning and construction of natural city will never compete with nature, but rely on geography, respect nature, conform to nature, get close to nature, continue history and culture, and guide urban planning and construction for healthy living. Since different regions have different geographical environments, climatic conditions, and historical cultures, natural cities must be regional cities, as well as diverse and individualized cities.
The natural city is an ecological city. It follows the natural process, pursues the integrity of the natural system, and is planned and constructed according to the principles of ecology. It has a natural ecological network with a complete structure and complex functions that connects the nature in the city with the mountains, rivers, forests, and fields in the region. The nature in the natural city is diverse and has complex functions. They constitute an ecological infrastructure with sufficient natural attributes and strong resilience to maintain the healthy operation of the city body, bear the ecological functions of purifying air, mitigating heat island effect, adjusting humidity, proofing wind and consolidating soil, conserving water source, tuning surface water, maintaining living environment and habitat, and maintaining biodiversity, support the dynamic balance and harmony between artificial construction and nature, and realize a safe, healthy, livable and beautiful living environment.
The natural city is an organic city. As a compact city, the non-hardened surface area inside the urban group is limited, but the natural space in the natural city has reached or exceeded the minimum value of the natural space that the city should have, and the potential of realizing this lies in the greening of the gray infrastructure in the city. The surface of some buildings and infrastructure can be covered by plants, the hardened surface can be permeable or collect water into the stormwater wetland, and the channelized river can be used for near-natural ecological restoration. Since the sum of the urban surface area plus the building and infrastructure surface area is far greater than the projected area of the city, the area of natural space in a natural city can be close to or even larger than the projected area of the city. The natural system composed of these natural spaces integrates single projects in the city, making the city a living and self-regulating organic city.
The natural city is a city of sharing. The ecological network of the natural city is also a social life network and an important public space system of the city. The network extends to mountains, rivers, forests, and fields outside the city, bringing natural scenery into the city, and also penetrates into urban blocks through corridors and micro-corridors, so that the open green space is conveniently accessible, connected and shared, and meets the needs of citizens for rest and sightseeing, entertainment, sports, communication, education, walking and bicycle commuting, and other diverse and rich uses. Conditional green spaces, such as parks, communities, campuses, and building roofs, can become productive gardens, which can not only bring about the production of vegetables, fruits, and other foods, but also allow residents to get closer to nature and create harmonious neighborhood interactions opportunities, allow children to receive more nature education, and at the same time allow citizens to participate in the management of urban nature.
The natural city is a poetic city. Human beings inherit not only the genes that people cannot live without nature, but also the aesthetic preference for appreciating nature. Since ancient times, Chinese people have entrusted their emotions and hearts to nature, and mountains and rivers have become the spiritual homeland of Chinese people. The natural city inherits the inherent landscape structure and culture of the city, expands the urban ecological space, improves the ecological system, and improves the ecological quality, so that citizens can see the green in front of the windows, touch nature outdoors, and reach the landscape and fields in the area along the corridors. A natural city is a city that respects the natural process and is planned and built according to the unique Chinese landscape construction idea on the basis of satisfying the comprehensive and complex functions of the city, and a city that Chinese people entrust their affections, live, and express the unique Chinese aesthetic way.
Human beings have created cities and achieved great progress in civilization, but they have also alienated themselves from nature. Harmonious coexistence with nature is the foundation of healthy human life, and the construction of natural city is the fundamental way to achieve a harmonious balance between human and nature in the city, so that "heaven and earth will return to their places, and all things will grow and develop".
本刊主编:王向荣 教授
Prof. Dr.-Ing. WANG Xiangrong
Chief Editor
引文格式
王向荣.自然城市[J].中国园林,2023,39(2):2-3.
相关阅读
中国园林·刊首语(2023-01) | 王向荣:风景园林学科发展的基石
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排版 | 李旻
校对 | 马琳
审核 | 金荷仙