文章来源：俞孔坚. 棕地——工业文明的孽债[J].景观设计学, 2012(4):26-27.
棕地（Brownfield，Brownfield Site，Brownfield Land）有广义和狭义之分，在最早使用棕地概念的美国的法律语境下，棕地是有严格定义的：“棕地是一些不动产，这些不动产的扩展、再开发和再利用受到现实的或潜在的有害物、危险物或污染的影响。”（The term "brownfield site" means real property, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant.）这一棕地概念不包括许多具有棕地物理和化学特征的污染地和废弃地，如联邦或州政府列出的优先治理的污染地，也不包括类似垃圾填埋场和由政府划定并管理的特定区域等场地。这个狭义的棕地概念主要是针对城市土地在再利用过程中可能出现的开发成本的增加而提出的，旨在保护投资者利益（使开发商免于环境诉讼困扰），同时保护使用者的健康。为鼓励棕地的再开发，投资者可获得政府的资助和税收的减免，用以清洁和再生场地。据美国棕地协会（National Brownfield Association）援引的数据，截止到2010年，全美有450 000块棕地，占地达500万英亩，相当于美国前60个大城市占地面积的总和。由于棕地的属性导致房地产贬值的金额达到两万亿美元。因此，棕地的治理具有重 要的生态、社会和经济意义。这是我们的前人（还包括我们这代人），更确切地说是“工业文明”所留下的孽债，需要 我们这代人及我们的后代加倍偿还给土地和社会。然而，这份孽债又岂止如此狭义？
从1962年至1971年，陷入越战泥潭的美军为了清除隐蔽越共游击队的丛林植被，用飞机向越南山林喷洒了7 600万升落叶型除草剂（橙剂，Agent Orange），使约200万公顷的森林和绿地变成一片棕黄，这一“棕地”约占越南国土面积的10%，致使400万无辜百姓受害，无数生灵遭殃。50年过去了，这片广阔的棕地仍然是地球上和人类心灵上的一块伤疤。
所有造成棕地因素的本质特征是危害生命。农药和除草剂被当做武器来使用以达到消灭敌人的目的，而其带来的危害却是对无辜百姓和土地持久的伤害。曾经用于人类战场的手段，也被用于人对自然的战斗。记得，最初使用具有大规模杀伤力的火焰喷射器杀灭“害虫”时，是何等的激动人心。就在1970年左右，公社的技术员来我们村第一次使用汽油喷火器杀灭“害虫”。杀虫手背着喷雾器，喷头上外挂一团棉花球，用高压箱喷出汽油，和战场上的火焰喷射器相仿。在稻子刚刚收割完毕时，所有昆虫和生物都在田埂的绿草丛中寻求庇护，火焰喷射器便来了。一群小孩紧随其后，欢呼雀跃，看那青蛙和蚂蚱之类当场暴毙烤焦，其他各种昆虫皆不能幸免。如此，使用了几年之后，虫害却更加严重。所以，就开始使用更严厉的大规模杀伤性武器，那就是DDT和六六六。就在我的童年短短几年时间里，田里的泥鳅、河里的鱼虾，林中的鸟兽，消失殆尽。后来知道，世界上在1940年前后开始广泛使用DDT和六六六，结果带来了严重的环境问题，大量农药残留在土壤、水和生物体内，因此也有了蕾切尔•卡森（Rachel Carson）的《寂静的春天》（Silent Spring）。所以，从20世纪60年代起许多国家开始禁止或限制使用。而在中国，直到20世纪80年代才停止使用这些农药。20世纪50年代以来使用的六六六达到500万吨，DDT达50多万吨，据报道分别占据全球总用量的33%和20%。受污染的农田1 330万公顷。土壤中累积的DDT总量约为8万吨。粮食中有机氯的检出率为100%，小麦中六六六成分含量超标率为95%。真所谓自食其果，报应可谓迅速，如此广大的农药“棕地”，我们将如何解救？
Brownfield — The Debt from Industrialization
The term "brownfield" can be interpreted in a narrow or broadserse.In the U.S.where the concept of brownfield was fist adopted,brownfield is specific and predsely defined in a legal context-'the term "brownfield site"mears real property,the expansion,redevelopment,or reuse of which may be complicated by the presence or potential presence of a hazardous substance,pollutant,or contaminant! By definition,this wouldrule out many contaminated sites and wasteland that possess the physcal and chemical dharacteristic of brownfield,such as high-ariorib clean-up sites identified the federal ar state governments, or landfills sites designated by federal or state governments. This narrow definition of brownfield, was proposed in light of potential increase in development cost for urbanland reuse process,acting to safeguard investors'interest(to exempt developers from the trauble of enviranment lawsuits)while protecting users' health.In order to encourage brownfield redevelopment, investors are entitled to governmental subsidy and tax reduction for cleaning up and regenerating the sites. According to the statistics quoted by National Brownfield Association,there are 450,000 brownfield sites in 2011,comprising 5 million acres of land thraughaut the US., whidh is equivalent tothe total acreage of US 60 largest cities Due to the properties of brownlield, the real estate depreciation amounts to $ 2 trillian. Therefore, treatment for brownfield has great significance in ecological, social, and economic terms. This debt left byour predecessors(also including our generation),or in other wards, the damage done by the industries, needs to be redtified and repaid to the land and society by this and subooquert generations.Yet,the debt is so much more.
Fram 1962 to 1971,U.S.troops that got bagged downin the Vietnam War attempted to destroy jungle cover shelding Metnamese Communist guerrillas by aerial spraying 76 millionlitres of herbicide defoliant (Agent Orange) over the mountain forest of Vietnam,turning 2millian hectares of forest and greenland,whidh makes up 10% of the national territary of Vietnam. into "brownfield".4 million innocent divilians were harmed andcountless non-human living creatures suffered.50 years on,the vast brownfield remains a scar both an the earth and an human mind.
Essentially, all the factors produding brownfield are detrimental to ife. Weapons, pesticides and herbicides have been used to successfully eradicate enemies. However the damage incirred an the innocent land and divilians lasts longer. Iranically, the weapans used an the battlefields were then employed by hunlans in their war against nature. I still remember how struck we were when flamethrowers first came to kill "pests".It was around 1970, when technicians of the people's commune fist came to our village and began to use gasoline flamethrowers to kill"pests". They carried an their back a spraver with a cotton ball attadhed to the nozzle and speyed gasoline with high pressure tanks,similar to flamethrowers on battlefields Immediately atter rice harvest,insects and animals were seeking shelter arnong the green grass abng the ridge of the fields.Then came the flamethrowers,fallowed by a crowd of jubilant and whooping children, watching frogs and grasshoppers get burnt and die. Other kinds of insects could not escape either. It continued forseveral years.However,insect damage got even warse.Thus people began to use more destrudive ammunition,such as DDTand BHC In just a few short years of my childhoad, the laadh in the fields,fish and shrimps in the rivers,birds and beastsin the forest were all gone. Later, I realized that DDT and BHC were widely used in the world around 1940, resulting in severeerrironmental cisis. The large amounts of pestidie residues in the soils, waters, and organisms, prampted Carson to writethe book,Slent Spring.Thus,since the 1960s these pesticides have been prohbited or restridted in many countries,while inChina their usage were not sto pped until 1980s. Since 1950s,5 million tons of BHC and over 500,000 tors of DDT had been used,which are reported to respedively make up 33% and 20%of the total world consumption. 13.30 milion hectares of farmlard have been contaminated. Appraximately 80, 000 tons of DDT have been acaimulated in soils in total. The detection rate of organochlarine pesticides in grain is 100%,and the exceeding standard rate of BHC content in wheat is 95%. As the saying goes, we reap what we sow; indeed it is a swift retribution. How are we gaing to remedy such vast pestidde filed "brownfleld?
Just as the use of DDT and BHC were being banned,township enterprises were encouraged on a large scale. Factories and mines sprung up like mushrooms. Industrialization spreadthroughout the land of China. Pollutants spread fast to urban and rural areas due to the shabby workshops, inferior technblagies, extensive processes, and slack ervironmental protedion policies. 10% of arable land in China have been severely contaminated. As urbanization takes hald, cities look to move heavy industry out of urban centers due market forces and their polluting output These factories quiddy became brownfield to be redeveloped. Together with the industrial land whidh previausly existed in Chinese cities,these fadories make up the largest propartian of brownfield in the narrow sense,throughout urbanand rural China.Statistics are yet to be gathered to calculate the acreage. But it is certain that, according to U.S. standard, this number will by far surpass that of the U.S. Unfortunately, we are not even certain how harmful it is for the new communitiesthat have built upon them.Yau coud sov.develoners in China are lucky,and the brownfield "producing"enterprises in Chinaare lucky. How ever, how long could the situation last? The debt owed shall be paid sooner or later!
Despite the dire situation, it is possible for landscape architeds, in a way, like Jesus who suffered for mankind, to start to repay this "brownfield" debt. No matter whether in cities or the countryside, farmland ar factory districts, landsca pe architeds can bring land badk to ife,and bring life back to harmony. In this respect, Chinese landscape architects are carrying a heavy bad on this long path to recovery.(Translated by Jin QIAN, Proofread by Anna CHAN)