風(fēng)景園林學(xué)科的工作對象面向廣大的土地地表空間，工作內(nèi)容主要涉及人工營建的建成環(huán)境和自然區(qū)域2個范疇。一方面，人們在建成環(huán)境中關(guān)注自然的營造，以滿足人類對于自然空間的原始追求；另一方面，在國土及區(qū)域的視角下，以人工干預(yù)的方式介入自然系統(tǒng)，通過整理土地、梳理自然過程、營建區(qū)域風(fēng)景，形成適于人居的環(huán)境領(lǐng)域。

區(qū)域水系統(tǒng)是以自然水文過程為基底，輔以人工梳理的方式，對地表水資源進(jìn)行綜合利用、服務(wù)于所在區(qū)域人居環(huán)境的重要支撐系統(tǒng)，它為一城一地提供了基本的環(huán)境支撐和安全保障。這種具有自然和人工雙重屬性的系統(tǒng)結(jié)構(gòu)是人居環(huán)境營建過程中形成的基于自然本底的解決方案，用低介入、高效率及綜合功能的方式應(yīng)對并不理想的自然水文環(huán)境。從古至今，隨著人類足跡覆蓋的區(qū)域不斷擴(kuò)大，人們對自然空間中水系的梳理從未停歇，針對復(fù)雜而多樣的地理環(huán)境和氣候條件，因地制宜地改造自然、興修水利，梳理區(qū)域水系統(tǒng)網(wǎng)絡(luò)，為農(nóng)業(yè)生產(chǎn)、生活用水、運(yùn)河傳輸?shù)忍峁┌踩?、可控的水資源與水環(huán)境。在干旱的區(qū)域使用沿坡引潛流和地下傳輸?shù)姆绞奖苊庹舭l(fā)；在河谷盆地區(qū)域利用地勢營建塘渠進(jìn)行傳輸與分流；在山前平原或淺山地帶，依托山體建造蓄泄可控的陂湖以最大限度地蓄積山體匯水；在山地區(qū)域開辟梯田，順山勢進(jìn)行逐級灌溉，實(shí)現(xiàn)水資源的高效利用；在低地沼澤區(qū)域構(gòu)建圩田系統(tǒng)，通過調(diào)整水陸關(guān)系，營建適宜耕作的土地區(qū)域和相應(yīng)的人居空間；在濱海沖積平原區(qū)域建造海塘、堰壩和灌渠，拒咸蓄淡……同時，這些土地整理的成果也為城市空間的營建提供了基本結(jié)構(gòu)，支撐區(qū)域水文安全的水系統(tǒng)也成為城市的環(huán)境支撐系統(tǒng)，影響著城市中山水形勢、布局結(jié)構(gòu)與風(fēng)景體系等。如此，人們通過主觀能動地改造并利用自然山水，來實(shí)現(xiàn)營建城市這樣具有高效、集約化特征的人居環(huán)境的目的。

歷史上中國人尤其擅于依據(jù)自然條件改造水與土地的環(huán)境來獲得更加安全和豐產(chǎn)的土地，在國土上諸多特定的地理單元構(gòu)筑了人工與自然緊密結(jié)合、相互適應(yīng)的典型區(qū)域水系統(tǒng)，如先民建造于天目山前河網(wǎng)平原的良渚塘壩水利系統(tǒng)、成都平原上的都江堰水利工程、太湖平原的圩田水網(wǎng)工程，以及杭嘉湖平原地區(qū)諸多的陂湖水利工程均是此類系統(tǒng)的典范。同樣在世界范圍內(nèi)，這樣的因地制宜的水利梳理方式為許多國家和區(qū)域帶來安全、穩(wěn)定與繁榮，如古巴比倫王國修建于幼發(fā)拉底河上的納爾漢謨拉比渠；建設(shè)于公元前3世紀(jì)的馬拉水庫；古羅馬帝國建設(shè)的一系列城市供水系統(tǒng)以及引水渠道；為貫通航道開展貿(mào)易而開鑿的蘇伊士運(yùn)河與巴拿馬運(yùn)河以及荷蘭為適宜低地濱海耕作而營建的圩田水網(wǎng)系統(tǒng)。

區(qū)域水系統(tǒng)在為人類提供安全與穩(wěn)定的水環(huán)境基礎(chǔ)上，亦承擔(dān)著養(yǎng)育民生生計(jì)、提供風(fēng)景游憩功能和催化人文藝術(shù)發(fā)展的作用。一方面，這些散落在土地上的水網(wǎng)塘渠、湖泊港汊是人居空間中獨(dú)特的風(fēng)景線，經(jīng)詩詞歌賦、藝術(shù)作品的渲染與世代傳頌，為眾多城市構(gòu)建了融山合水、詩情畫意的風(fēng)景體系。水不僅成為人們眼中生動而美好的圖景畫卷，亦是人們心中對于一方土地鄉(xiāng)土地脈的空間想象。同時，人們圍繞著水展開生產(chǎn)生活，或捕魚放棹，或泛舟為市，或采菱種藕，水成為一個區(qū)域生活方式與文脈的底色乃至經(jīng)濟(jì)繁榮的動脈，世世代代影響著扎根這片土地的人們。

由此可見，從古至今區(qū)域水系統(tǒng)都是區(qū)域水文安全、生產(chǎn)生活、自然生態(tài)以及風(fēng)景建構(gòu)的重要支撐系統(tǒng)，承載了區(qū)域自然和文化的復(fù)合特征，發(fā)揮著城鄉(xiāng)基礎(chǔ)設(shè)施的重要作用。然而隨著現(xiàn)代化城市建設(shè)，一些傳統(tǒng)的基礎(chǔ)設(shè)施系統(tǒng)因不斷被蠶食而失效，造成了污染、內(nèi)澇、生境破壞等一系列環(huán)境問題，又不得不依靠昂貴和生硬的現(xiàn)代基礎(chǔ)設(shè)施來解決，帶來更高強(qiáng)度的干預(yù)與破壞。這需要我們不斷反思，現(xiàn)下對于水系統(tǒng)的建設(shè)及對于水資源的開發(fā)利用是否超出了自然承載能力，歷史上傳統(tǒng)水系的內(nèi)涵是否得到了充分認(rèn)知與價(jià)值沿襲，是否有更優(yōu)的統(tǒng)籌與協(xié)調(diào)水生態(tài)空間與建設(shè)空間的方式……

在現(xiàn)今國土空間規(guī)劃等綜合性、系統(tǒng)性戰(zhàn)略發(fā)展路徑逐步實(shí)施的大背景下，區(qū)域水系統(tǒng)的視野提醒我們，城市不應(yīng)是脫離自然環(huán)境而孤立存在的單體，對于任何一個城市空間的規(guī)劃與設(shè)計(jì)都應(yīng)充分認(rèn)知其所在的山水格局與多元的自然稟賦，在尊重、利用自然脈絡(luò)的基礎(chǔ)上，在保持人居空間與自然環(huán)境動態(tài)平衡的系統(tǒng)穩(wěn)定中尋求發(fā)展的路徑。可以說，區(qū)域水系統(tǒng)提供了將城市及其所在地理單元進(jìn)行統(tǒng)籌考慮的重要視角，是構(gòu)建區(qū)域人居生態(tài)環(huán)境的重要基礎(chǔ)與媒介，并且有機(jī)遇成為當(dāng)今城市應(yīng)對生態(tài)環(huán)境問題挑戰(zhàn)、探索生態(tài)文明建設(shè)路徑乃至實(shí)現(xiàn)大區(qū)域協(xié)同發(fā)展的重要解決方案與實(shí)施抓手，從而以區(qū)域水系統(tǒng)為載體營造具有水文安全、生態(tài)韌性、詩意風(fēng)景、獨(dú)特人文價(jià)值且可持續(xù)發(fā)展的人居生態(tài)環(huán)境共同體。

Regional Water System Construction

The discipline of landscape architecture, which takes the vast land surface space as its work object, mainly involves two categories: the built environment of artificial construction and natural area. On the one hand,focusing on the creation of nature in the built environment, people create the environment to meet their original pursuit for natural space. On the other, from the perspective of region, artificial intervention is carried out based on the context of natural system to form an environment suitable for people’s survival and life through land consolidation, natural process sorting and regional landscape construction.

Regional water system is an important environmental support system for regions, which makes comprehensive use of surface water resources based on natural hydrological processes and supplemented by artificial combing, providing basic environmental support and security for cities and their regions. It can be said that such a system with both natural and artificial attributes is a nature-based solution formed in the process of human settlement construction, which deals with the natural hydrological environment that is not ideal in a low-intervention, highefficiency and multi-functional manner. Since ancient times, people have been combing the water system. Human beings are constantly exploring to undertake water conservancy projects according to specific geographical environment and climate conditions, thereby providing safe and controllable water resources and water environment for agricultural production, domestic water use and canal transportation. In arid areas,people use underground transport and well drilling to avoid evaporation;in valley basin areas, the terrain is used for transmission by pond channels; in the piedmont plains or shallow mountain zones, impounding lake system is built so that runoff water can be collected to the maximum extent; in mountainous areas, terraced fields allow irrigation being carried out step by step along the mountain to realize efficient water utilization;in lowland area, polder system is constructed to create suitable land areas for farming and corresponding living spaces; and in the coastal alluvial plains, seawalls, weirs and channels are built to intercept salt water and store fresh water... Simultaneously, settlements and cities are built accordingly, the land consolidation experience has gradually evolved into the basic structure of city space, and the water system that supports regional hydrological security also works for the cities. By transforming and using the natural landscape subjectively and actively people could build an efficient and intensive living environment.

Historically, to obtain more productive and secure land, the Chinese have adapted their environment to natural conditions. As a result, a variety of typical regional water systems were constructed in specific geographical units, in which the artificial and the nature are closely combined and adapted to each other, such as Liangzhu water conservancy system, Dujiangyan water conservancy project in Chengdu Plain, polder water network in the Taihu Plain, impounding lakes in Hangjiahu Plain and etc.. There were many such approaches adopted in other regions in the world, which have brought security, stability and prosperity to many countries, including Narl-Hammurabi channel built by the Kingdom of Babylon on Euphrates, the Mala reservoir built in the 3rd century BC,a series of city water systems and aqueducts built during the Roman Empire, the Suez and Panama Canals built to link shipping lanes for trade, and polder system for lowland coastal farming in the Netherlands.

Regional water system not only furnishes human beings with a safe and stable water environment, but also plays the role of raising people’s livelihood, providing recreation landscape and promoting the development of humanities and arts. On one hand, these water networks, ponds, rivers and lakes scattered on the land constitute a unique landscape in the living space, building poetic landscape system for many cities, which, in people’s minds, has become not only a vivid picture, but also a spatial imagination of a place after passed on generations by poems, songs and works of art.Besides, water has become the background color of a region’s lifestyle,like fishing, or boating, or harvesting, or trading, and even the artery of economic prosperity, affecting the people rooted in the land for generations.

Thus, from ancient times to the present, regional water system has been an important support system for region’s security, production and living, natural ecology and landscape construction, bearing the composite characteristics of regional nature and culture, and playing a crucial part in urban and rural infrastructure. Today, however, with the construction of modern cities, some traditional infrastructure systems have been encroached, losing their original functions, as a result of which, a series of environmental problems such as water pollution, water-logging and habitat destruction emerge, which need to be solved relying on modern infrastructure, thus bringing further intensity intervention and destruction.This requires constant reflections: Does the construction of water system and the exploitation and utilization of water resources exceed the natural carrying capacity? Has the connotation of traditional water systems in history been fully recognized and their value been inherited ? Is there a better way to coordinate water ecological space and construction space?

In the context of the gradual implementation of reform paths in territorial space planning, the perspective of regional water system can remind us that cities should not be isolated from the natural environment,that for the spatial planning and design of any city, we should fully understand their landscape pattern and diverse natural endowments and that we should seek the path of development while maintaining the system stability of dynamic balance between human settlement space and natural environment on the basis of respecting and utilizing the natural context. Regional water system, which provides an important perspective to consider the unity of cities and their geographic units, is the foundation and medium of constructing regional human settlement ecological environment and has the potential to become a way for cities to deal with the challenges of ecological environment and explore the construction of ecological civilization and even an important solution to realize the coordinated development of large regions. Therefore, regional water system should be used as the carrier to build a sustainable community of human settlements ecological environment with hydrological security,ecological resilience, poetic scenery and unique humanistic value.

Acquiring editor of the current issue: WANG Xiyue

January 26, 2022