俞孔堅：論美麗城市的“三重奏”

論美麗城市的“三重奏”

俞孔堅

哈佛大學設計學博士；美國藝術與科學院院士；

北京大學建筑與景觀設計學院教授；美國景觀設計師協會榮譽會員

原文刊發時間：2020年10月

在新冠肺炎疫情（COVID-19）初步穩定后，中國多個部委和全國各大城市政府將城市品質提升行動視為頭等大事，逐步推進起來。在剛剛過去的7月和8月，我受邀參與了十多場部級、市級專家咨詢會和授課活動，可見，如何建設和管理高品質的美麗城市已經成為實現“美麗中國”愿景及人民對美好生活向往的關鍵抓手。

如今，城市已成為人類的主要家園，而家園的本質在于人與土地、風、水和生物的生態關系。盡管城市的美麗可以表現在許多方面——諸如社會的公平與和諧、文化的豐厚與多彩、經濟的繁榮與活力、生活的富足與幸福、建筑與景觀的獨特與精美、居民的歸屬感和認同感——但是，美麗城市的根本是人與自然的和諧共生。沒有這份和諧，再親密的人群也將被迫隔離，正如COVID-19肆虐下的居民；沒有這份和諧，再厚重的文明、再多彩的文化、再繁榮的社會也可能頃刻間崩塌；沒有這份和諧，再宏偉的建筑、再精美的園林也將黯然無光。回望歷史，遙遠的1900年前，古羅馬文明的精華之城龐貝，一夜之間被火山灰吞沒，留下的僅僅是烤焦的殘垣斷壁和仍似在痛苦掙扎的人體遺骸；不遠處的2004年，正在美麗的東南亞濱海城市享受幸福人生的20余萬名游客，瞬間被印度洋海嘯吞噬^[1]；最近的2008年，汶川地震轉眼便令近7萬個鮮活生命消失，美麗的山城化作瓦礫^[2]；以及今天正在泛濫和明天即將到來的滔天洪水，威脅著繁華的城鎮和歡樂的人群……

人與自然和諧共生，是美麗城市的根本。以此為根本的城市才是可持續的、堅實而有活力的，其所呈現的形態是一種“深邃之美”：即將人類欲望建立在與自然格局與過程的和諧共生之上。這樣的深邃之美，需要從三個維度進行構建：一是美的格局，即深邃的結構；二是美的形態，即深邃的外形和風貌；三是居民的行為，即綠色生活。這便是美麗城市的“三重奏”。

其一，美麗城市的深邃結構。城市與自然的關系首先體現在空間上，可以從“自然中的城市”和“城市中的自然”兩個方面來概括。前者是上帝視角下的國土景觀，城市僅僅是國土空間中一些微小的點，甚至不足總面積的1%，因此既有的美麗城市的首要之功在于擇一良好城址。這一理念在古代山水信仰中被稱為“穴”^[3]，乃大自然母親的胎息所在。自然與城市的關系便如同父母之于子女，兼有不可冒犯的威嚴和難以抗拒的懲罰，及安全庇護等綿綿恩澤——這種恩澤在當代被稱為“生態系統服務”^[4]。而古代的龍脈、祖山、風水林、水口、護砂等構成的“神山圣水”格局，在當代則被稱為“國土生態安全格局”或“生態安全屏障”^[5][6]。在這一視角下，美麗城市的深邃結構呈現為城市選址能否與自然和諧共生，城市能否遠離洪澇和海潮、山崩和地裂、火山和海嘯等自然災害，這將決定城市能否長存。

“城市中的自然”則是蒼鷹的鳥瞰，和諧的城市與自然的空間關系應呈現為鑲嵌在城市基底上的連續、健康的自然系統——山－水－林－田－湖－草生命共同體在方圓幾十甚至上千平方公里的紅塵世界中鋪展開來，包括連續的生態廊道、生機勃勃的濕地與湖泊、充滿活力的公園綠地等，它們構成了一個能為城市提供自然生態系統服務的生態基礎設施。在這一視角下，城市是否具備深邃的結構，取決于這一生態基礎設施是否連續完整（包括能否與區域自然山水格局和過程保持連通），以及是否具有足夠空間來維持城市的生態韌性—能否為區域洪水提供充足的調蓄空間而不致使災害；能否有效降解污染、緩解熱島效應、提供多樣的生物棲息地，甚至為城市提供部分水、食物、能源和建材；鳥兒在飛行中，能否找到哪怕只是短暫歇腳的“跳板”；魚兒在游經城市水域時，能否順暢地到達上游產卵；地震或其他災害發生時，人類是否有足夠的躲避空間和時間；城市能否為居民提供充足的身心再生機會，例如當他們被隔離時，是否仍能方便快捷地進入自然，并獲得自然服務……因此，美麗城市的深邃結構就是一個城市基質與自然生態網絡相互嵌合的和諧圖底關系，是城市適應于自然的空間格局。那些與自然為敵的斬山沒谷、斷河筑壩、填湖造城等浩大工程所成就的“美麗”，終究是膚淺的、不可持續的。

其二，美麗城市的深邃外形和風貌。在人們的日常活動范圍和視野里，城市是由街道、建筑、開放場所（如廣場、自然地和公園等）所構成的活動空間。在這一層面上，美麗城市的深邃之形由自然和人文因素相互疊加構成。例如，山坡上的梯田即是底層的地形、土壤和水文過程的顯現，而人類明智的開墾和農作則是適應自然過程和巧妙利用自然力的一種表征。這一深邃就在于這是人類適應于自然的結果——猶如白鷺佇立在田間，只因其適宜生存于淺灘濕地。這種城市對于自然的生態適應成就了城市空間的深邃之美，也成就了城市的美麗風貌。生態適應的本質是經濟學意義上的節約和人類學意義的節制——用最少的能源、物質和人力來建造城市，便可獲得街道、建筑和開放空間的深邃之美：蜿蜒起伏的道路、順地形而錯落的建筑群、就地勢而營造的河網和湖泊、適地而栽植的樹木花草，都是適應自然衍生出的深邃之美。因此，我們贊美舊時重慶的山城步道、吊腳樓和黃葛樹（Ficus virens），欣賞延安的黃土墻、窯洞和棗樹（Ziziphus jujuba），懷念北京的胡同、四合院和槐樹（Styphnolobium japonicum），迷戀廣州的河涌水街、騎樓和木棉（Bombax ceiba）。然而，當八車道路網橫貫重慶，當本地樹種被外來樹種所替代，重慶這座城市也隨之失去了深邃之美。只因不理解美的形態，這樣的“化妝”幾乎在中國所有的城市上演！

其三，美麗城市的綠色生活。城市的美麗還因市民的綠色棲居、綠色出行、綠色消費而深邃。如果說美麗城市的深邃結構中，人類之于自然猶如子女之于父母，敬畏而又依戀；在深邃形態之中，人與自然猶如相愛的夫妻；那么，在綠色生活成就的美麗城市中，人與自然的關系就猶如父母之于子孫——其深邃的含義在于人類作為父母對其后代的責任和關愛，這便是可持續發展理念的本質：既滿足當代人的需求，又保障后代人滿足需求的可能性。當街道上有更多的人在步行或騎行，而不是被小汽車填滿時，城市便多了一份對后代的關愛；當建筑減少了對空調的使用，屋頂和墻面上長滿綠色的植被，城市便為后來者留出了更大的生機；當雨水被收集、廢水不再排入溪流、垃圾獲得循環，城市便增添了一份讓后人感激的溫暖；當食品能就地生產、包裝少去一層華麗外殼、一次性餐具和塑料袋不再泛濫，城市便多了一份愛意。而綠色的生活方式可歸結為對物質和能源的節約、循環和再生，表現為對自然資產的珍惜、對生態系統健康的關愛和對其他生命的關照，這終將促進綠色生產方式的發展。

終了，請不要誤解，我們絕不是在倡導極端的環保主義或宗教的禁欲主義，更不是反城市主義或出于對過往人類城市文明的懷舊。城市是人類文明的載體，是人類價值觀、審美觀在大地上的烙印，是人類欲望和自然力之間的平衡。眼前的工業文明和消費主義，向蕓蕓眾生撩撥無度的消費欲望、催生極其浪費的生活和生產方式，并以前所未有的機械和化學力摧毀著自然格局、毒化著自然過程和生命萬物；唆使人類凌駕于自然之上，罔顧子孫的未來。于是，城市縱然綿延千里，防護之墻鋼鐵般堅硬，街道氣勢恢弘，建筑巍峨壯麗，園林極盡奇巧，也終究淺薄無根，或毀于洪濤劇震、或掙扎于污水濁氣。只有在繼承過往文明成果的基礎上從與自然的矛盾沖突中不斷反思，才能使我們走向新的文明——生態文明；這樣的人與自然和諧共生的城市美麗，便是深邃之美、生態之美、（尊重自然和基于自然的）“大腳之美”，與可持續發展之美。

On the “Trio” of Beautiful Cities

Doctor of Design at Graduate School of Design, Harvard University; Honorary Foreign Fellow of the American Academy of Arts and Sciences; Professor of College of Architecture and Landscape, Peking University; Fellow of American Society of Landscape Architecture

With COVID-19 under control, the urban quality improvement has been considered a prioritizedinitiative across China by many ministries, commissions, and municipal governments. In thepast July and August, I was invited to participate in more than a dozen ministerial and municipalexpert consultations and lectures. The Beautiful China construction requires the wise creation andmanagement of high-quality beautiful cities to realize the people’s desires for a better life.

Today, to human beings, cities have become homes that inherently lie in the ecological relationshipbetween human and land, wind, water, and other creatures. The beauty of a city is regarded bymany aspects—including the justice and harmony of society, the diversity of culture, the prosperityand vitality of economy, the abundance and happiness of life, the uniqueness and exquisiteness ofarchitecture and landscape, and residents’ sense of belonging and identity. Such a beautiful city isbuilt on the harmony and symbiosis between human and the nature—without this harmony, eventhe most intimate people will be isolated, just like the ones under the impact of COVID-19; withoutthis harmony, no matter how rich a civilization is, how brilliant a culture is, or how prosperousa society is, it might all collapse in an instant; without this harmony, no matter how magnificenta building or how elaborate a garden is, it would become pale. Such misfortunes are numerous:far back to 1,900 years ago, Pompeii, an epitome of ancient Rome civilization, was swallowedby volcanic ash overnight, leaving nothing more than scorched ruins and human remains that stillwrithing in agony; not as far as in 2004, more than 200,000 tourists^[1], enjoying a happy time inthe beautiful coastal city of Southeast Asia, were instantly engulfed by the Indian Ocean tsunami;in recent 2008, Wenchuan Earthquake took away nearly 70,000 lives and made the beautifulmountainous city destroyed^[2]; and the monstrous floods that is threatening thousands of cities andtowns, as well as our lives, all the time….

To the deep structure of a beautiful city, the relationship between city and the nature is reflected inspatial configurations that can be summarized into “the city in nature” and “the nature in the city.”The former refers to the national-scale landscape from God’s-eye view, where cities are distributedlike mosaics in the territory, taking less than 1% of the total area. Therefore, the primary meritof a beautiful city is a good site selection, which echoes with the metaphor of “cave” (a symbolof the womb of Mother Nature) in China’s ancient landscape beliefs^[3]. The relationship betweenthe city and the nature can be compared to that between children and their parents: the nature notonly has the absolute dignity and can exert irresistible punishment, but also offers safe sheltersand continuous kindness—which is called “ecosystem services” in modern sciences^[4]; the ancientdragon veins (i.e. rolling mountains), ancestral mountains (i.e. the origin of dragon veins), fengshuiforests (i.e. the forests reserved for ideal living conditions), water gates (i.e. inlets or outletsof water bodies), and earth protection (i.e. the hills that protect caves) composed the pattern of“sacred mountains and holy waters,” which is now called “national ecological security pattern” or“ecological security buffers”^[5][6]. In this regard, the deep structure of a beautiful city is defined asthe city’s location safety, i.e. whether the city stays away from natural disasters such as floods andtides, landslides and earthquakes, volcanoes and tsunamis.

“The nature in the city” is the picture captured from the goshawk’s-eye view—continuous andhealthy natural systems embedded in urban matrix. A complex community consisting of mountains,rivers, forests, farmlands, lakes, and grasslands spreads out tens or even thousands of squarekilometers on the earth, forming continuous ecological corridors, lively wetlands and lakes, vibrantparks and other green spaces, all of which constitute an ecological infrastructure that can providethe city with natural ecosystem services. In this regard, the deep structure of a beautiful cityalso requires a continuous and complete ecological infrastructure (which needs to be integratedwith regional natural landscape pattern and process), and enough space to sustain the ecologicalresilience of the city. To be specific, the resilience is reflected by the sufficient spaces to retain andstore the floods in the region; the effective reduction of pollution and heat island effect; the diversehabitats; the provision of water, food, energy, and building materials; a “springboard” or even ashort rest for birds; a channel in urban environments for fish migration; enough safe spaces andtime for people to escape from earthquakes or other disasters; and rich opportunities to access tothe nature and enjoy its services for physical and mental relief in case of public emergencies suchas under quarantine… Therefore, the deep form of a beautiful city must stem from an interwovenpattern between urban matrix and natural ecological network, i.e. the adaptive pattern to thenature. The “beauty” of large-scale manmade projects which destroys the nature by means ofcutting mountains and filling valleys, breaking rivers and building dams, replacing lakes withnew towns, etc. is bound to be superficial and unsustainable.

To the appearance and style, the deep form of a beautiful city, which offers daily activity spacesfor people (streets, buildings, and open places such as squares, natural areas, and parks), is shapedby a combination of natural systems and humanity. For instance, the manmade terraced fields onthe hillside manifesting the underlying topography, soil, and hydrological processes, are reclaimedand farmed through the adaptation to natural processes and the wise use of natural forces. The deepform is precisely the result of human beings adapting to the nature—like an egret living in fields,since they prefer shallow wetlands.

Such ecological adaptation processes of the city to nature witness the deep beauty of urban spaces,as well as the beautiful appearance of the city. The ecological adaptation is essentially considered“saving” in Economics and “moderation” in Anthropology, through which streets, buildings, andopen spaces with the deep beauty can be created with minimal energy, materials, and manpower.Inspired by the nature, the road network, the buildings, and the constructed river systems andlakes, and the trees and flowers designed in accordance with the terrain, hydrology, and climateconditions are all of deep meaning. Accordingly, we miss the old mountain trails, irregularbuildings, and Ficus virens in Chongqing city; admire the loess walls, cave dwellings, and Ziziphus jujuba in Yan’an city; appreciate Beijing’s hutongs, courtyards, and Styphnolobium japonicum; andlaud Guangzhou’s Heyong Water Street, arcade buildings, and Bombax ceiba. However, the beautyof these cities now are losing, for instance, in Chongqing due to the construction of eight-laneroad networks and the substitute of exotic tree species for the native ones. Unfortunately, almostall the cities in China are undergoing such “beautification movements” that run counter to the realbeautiful form.

In terms of the green lifestyle, a deep beauty of the city is also elaborated by green living,green traveling, and green consumption. If the relationship between human beings with thenature is compared to what children with their parents to the deep structure of beautiful cities, to what couples in love to the deep form, then, to the green lifestyle, the relationship is likewhat the grandparents to their grandchildren, in which relationship the deep meaning lies in“responsibility” and “care.” They are the essence of sustainable development: not only to meetthe needs of contemporaries, but also to support the living of future generations. In the city, suchresponsibility and care is manifested in the increase of cyclists and pedestrians and the reduction of cars; in the increase of plant-covered roofs and walls and the less use of air conditioners; inthe increase of collected rainwater, recycled sewage, and recyclable garbage; in the promotion oflocal production of food, the decrease of unnecessary packaging and disposable tableware, and nouse of plastic bags. A green lifestyle will eventually promote the development of green productionmode. In conclusion, citizens’ green lifestyle can be understood as the conservation, recycling, andregeneration of materials and energy, the treasure of natural resources, the concerns on the health ofecosystems, and the care for other lives.

Please do not take it wrong. I am not an extreme environmentalists, a religious asceticism, ananti-urbanist, or a nostalgist indulging in human urban civilization of the past. Instead, I believethat cities are the fruit of human civilization, the imprints of human values and aesthetics, andthe negotiation between human desires and natural forces. Today, the industrial civilization andthe consumerism not only encourage people’s endless desires and wasteful ways of living andproduction, but also destroy natural patterns and poison natural processes and creatures withunprecedented mechanical and chemical forces. All these incite people to override and manipulatethe nature without any consideration for the future descendants. Although the city could stretch forthousands of miles with steel-like walls, magnificent streets and buildings, and ingenious gardens,all the boom will be doomed to suffer from natural disasters. The ecological civilization, drawinglessons from the conflicts with the nature in the past civilizations, is the only way to achieve thehuman-nature harmony, as well as the deep beauty, the beauty of ecology, the “Beauty of Big Feet”(that honors and relies upon the nature), and the beauty of sustainability.

翻譯 丨 張健、田樂、冉玲于

制作 丨 呂童