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摘自：寂靜的河川 ：大型水霸的生態及政治 第一章
歷史中若沒有水，那麼就是遺漏一項主要的部分。人類的經驗已經面臨從來沒有過的乾涸。
作者 Donald Worster帝國之河，1985
所有的陸地都是屬於分水嶺或盆地流域的部份區域，都受到水流經該處或直接穿過的塑造。事實上，河流可說是整體陸地的部份，在許多地點可以貼切的說河川名勝就是陸地的風景名勝。一條河流的水量比流到海洋的量還多得多。經常變動的河床、河堤和地下水均是河流的整合帶。甚至草地、森林、沼澤和回流的水均可視為河川的一部份。河水不僅往下游走，還有一些重要的沖積物，可溶性礦物質，以及動植物和其富含營養的碎屑也都隨著水流而走。
每個集水區源於山峰和陵線。融雪和降雨沖刷整個高地然後進入小溪，再導入流速快的的山溪中。當山溪一直在延伸時，其支流和地下水也會不停的注入增加流量成為河川。當離開山頭時，河水流速減慢開始蜿蜒交錯，從最小的支流逐漸增加流域範圍，再經過千年沖刷物的堆積形成沖積層，河流最後也會流入湖泊或海洋。當河川逐漸混濁且地形平坦，沈澱物會在此形成三角洲，且將分流展開成如鳥腳般狀然後注入海洋。河口灣就是淡水和海水的混合區，通常這裡也就是河流與海洋極豐饒生物相的棲息地。世界上大部分所捕獲的魚類，是來自倚賴富含營養物的河口棲地而生活的物種。
河川的多樣性不僅在於其所流經的不同國家，還有其季節更換，乾和雨年度的不同。特別是在一年當中只有在暴風雨來臨時才會下雨的乾旱帶，其河川水量可反應其季節性、年度的變化，這時由集水區排出的沖積物和營養物會大量增加。在南非的林波波(Limpopo)河，每年3月至5月的流量平均佔全年總量的85％，而在8月到10月卻只有1％。在更北的許多河川也顯示具有高度季節性，在凍結的冬天流量最小，夏季融雪流量則相當大。
人類歷史最大的里程碑都是發生在河岸地區。由化石紀錄顯示最早的人類祖先是在衣索匹亞的AWASH河沿岸所發現。以考古學的時間和重要證據推測約於9萬到10萬年前的大部分游牧狩獵到定居農耕首先出現在近東山區的兩河流域。一路沿著幼發拉底河、底格里斯河、尼羅河、印度河和稍微晚期的黃河，於西元前三世紀就以出現文明開化的國家。更晚期重要轉捩點則是發生在北英格蘭流域，孕育了早期的工業時代。
河川，以及豐富的動植物，提供了獵人-採集者的社會賴以為生的東西，包括飲用及洗用水、食物、藥劑、醫藥、染劑、纖維和木材。農人收割、也可獲得同樣的好處，以及當有須要還可以用於灌溉穀物。對遊牧社會而言，於廣闊的地區放牧，沿著河川堤岸不論乾濕季都會提供賴以維生的多年生植物的食物及飼草。鄉鎮和城市則是利用（或濫用）河川來攜走垃圾廢物。河川也可當做商業、探險和戰利品的道路。撰寫科技的歷史家Lewis Mumford,寫道：除一些沿海社會外，所有偉大歷史的文化都是沿著大河的自然水道，而驅動人們和機構，以及發明和貨物的流通而興盛。
河川的角色就如同生命的支持者，而其生命孕育力就反應在神話中和各種文化的信仰裡。地球上許多河流被譽為是 "母親"：「 Narmadai, Mother Narmada'; the Volga is Mat' Rodnaya」，"大地之母 "，泰文的河「mae nan」，逐字翻譯則為"水之母"。河川常與神性聯想在一起，特別是女神。早期的埃及，若尼羅河氾濫時則被視為是女神「伊曦絲」(Isis)的眼淚。愛爾蘭的波恩河，被視為最感人的史前埋葬地點，凱爾特族人即是以女神儆仰。
印度的河流比其他國家或許被包裹更多的神話，以及更多史詩故事和宗教性價值。環境學家Vijay Paranjpye描述一段令人寒顫的話，內容是洗淨罪惡需要在Saraswati內沐浴三次，在Yamuna要洗七次，在Ganges一次，但只有經過Narmada的察看才能洗淨一個人的所有的罪。另外一個古代記錄描述Narmada 河就像「快樂的給予者」，「具風味佳的」，「高尚的態度」，和「散發快樂者」。
河川孕育的生命中，鮭魚算是被瀰漫最具神話性的意義。鮭魚的知識傳說中也有它，悠游在近波恩河的源頭。任何品嘗過鮭魚的人都必要瞭解世上的任何事，包括過去、現在和未來。北大西洋的美國原住民相信逆流而上的鮭魚是最優秀的，為人類利益而死，而歸回至它們偉大的家---海洋，在那裡有如同人類般的享受及起舞。有些原住民部落會舉行如同拜頭目的儀式，歡迎在當季第一隻到來的鮭魚。
當河水孕育生命時，也會帶來死亡。在平原上殖民可幫助人類利用沖積土的優點，但也使穀物和村莊曝露在具毀滅性的水災危機中。Gilgamesh，最早的故事傳說述說著上帝為要譴責「美索不達米亞」罪惡的人民而釋出大洪。大洪水的傳說和神話常出現在這些世界文化當中，從舊約猶太人到異教挪威及美洲原住民。
全世界築壩的工程為自然界的集水區帶來極大的轉變。沒有東西可如同水壩將河流完全的改變。水庫與河川形成明顯的對比，河川的本質是動態的，而水庫則相反。自然界的河川具有活力，也一直不斷地在改變中，如侵蝕河床、土壤的堆積、尋找新河道、破壞河堤，最後乾涸。水壩是幾乎靜態的，主要是為了能夠調節河川季節性的氾濫及減緩流速。水壩淤積沈澱物及養分，改變河水的溫度、化學物質、擾亂河川對周圍地表地質侵蝕和土壤堆積的過程。
原文詳見:http://www.irn.org/basics/history.shtml
版權歸屬 International Rivers Network，環境信託協會 (曾秋莉譯，鄭先祐審校)
中英對照全文：http://news.ngo.org.tw/issue/water/
issue-water-irn000060501.htm |
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Excerpted from Silenced Rivers: The Ecology and Politics of Large Dams, Chapter 1.
To write history without putting any water in it is to leave out a large part of the story. Human experience has not been so dry as that.
Donald Worster Rivers of Empire, 1985
All land is part of a watershed or river basin and all is shaped by the water which flows over it and through it. Indeed, rivers are such an integral part of the land that in many places it would be as appropriate to talk of
river scapes as it would be of landscapes. A river is much more than water flowing to the sea. Its ever-shifting bed and banks and the groundwater below, are all integral parts of the river. Even the meadows, forests, marshes and backwaters of its floodplain can be seen as part of a river - and the river as part of them. A river carries downhill not just water, but just as importantly sediments, dissolved minerals, and the nutrient-rich detritus of plants and animals, both dead and alive.
A watershed starts at mountain peaks and hilltops. Snowmelt and rainfall wash over and through the high ground into rivulets which drain into fast-flowing mountain streams. As the streams descend, tributaries and
ground waters add to their volume and they become rivers. As they leave the mountains, rivers slow and start to meander and braid, seeking the path of least resistance across widening valleys, whose alluvial floor was laid down by millennia of sediment-laden floods. Eventually the river will flow into a lake or ocean. Where the river is muddy and the land flat, the sediments laid down by the river may form a delta, splitting the river into a bird-foot of distributaries which discharge into the sea. The river's estuary, the place where its
sweet waters mix with the ocean's salt, is one of the most biologically productive parts of the river - and of the ocean. Most of the world's fish catch comes from species which are dependent for at least part of their life cycle on a nutrient-rich estuarine habitat.
The diversity of a river lies not only in the various types of country it flows through but also in the changing seasons and the differences between wet and dry years. Seasonal and annual variations in the amount of water, sediment and nutrients drained by a watershed can be massive, especially in dry areas where most of a year's rain may fall in just a few individual storms. On average 85 per cent of the annual discharge of the Limpopo in southern Africa flows from January through March; only one per cent from August through October. Rivers in the far north are also highly seasonal, with minimum flows during the frozen winter followed by huge floods during the summer melt.
The great milestones of human history took place by the banks of rivers. Fossilized remains of our earliest known hominid ancestor were found by Ethiopia's Awash River. Evidence of the momentous change from mostly nomadic hunting and gathering to sedentary farming first appears in the narrow river valleys of the mountains of the Near East at archaeological sites between nine and ten thousand years old. The first civilizations emerged in the third millennium BC along the Euphrates, Tigris, Nile and Indus, and a little later along the Yellow. Much later another momentous turning point in human history occurred along the rivers and streams of northern England which powered the early industrial factories.
Rivers, and the rich variety of plants and animals which they sustain, provide hunter-gatherer societies with water for drinking and washing, and with food, drugs and medicines, dyes, fibres and wood. Farmers reap the same benefits as well as, where needed, irrigation for their crops. For pastoral societies, who graze their herds over wide areas of often parched plains and mountains, perennial vegetation along the banks of rivers provides life-sustaining food and fodder during dry seasons and droughts. Towns and cities use (and misuse) rivers to carry away their wastes. Rivers also serve as roadways for commerce, exploration and conquest. With the exception of a few maritime societies, 'all the great historic cultures,' writes technology historian Lewis Mumford, 'have thriven through the movement of men and institutions and inventions and goods along the natural highway of a great river.'
The role of rivers as the sustainers of life and fertility is reflected in the myths and beliefs of a multitude of cultures. In many parts of the world rivers are referred to as 'mothers': Narmadai, 'Mother Narmada'; the Volga is Mat' Rodnaya, 'Mother of the Land'. The Thai word for river, mae nan, translates literally as 'water mother'. Rivers have often been linked with divinities, especially female ones. In Ancient Egypt, the floods of the Nile were considered the tears of the goddess Isis. Ireland's River Boyne, which is overlooked by the island's most impressive prehistoric burial sites, was worshipped as a goddess by Celtic tribes.
The rivers of India are perhaps wrapped in more myths, epic tales and religious significance than those of any other nation. Environmentalist Vijay Paranjpye describes a sacred text which holds that 'all sins are washed away by bathing thrice in the Saraswati, seven times in the Yamuna, once in the Ganges, but the mere sight of the Narmada is enough to absolve one of all sins! ' Another ancient text describes the Narmada River as 'giver of merriment', 'flavourful', 'of graceful attitude', and 'one who radiates happiness'.
Of the life sustained by rivers, salmon have perhaps been imbued with the most mythological significance. The 'Salmon of Knowledge', legend had it, swam in a pool near the source of the Boyne. Anyone who tasted the fish would acquire understanding of everything in the world, past, present and future. Native Americans in the Pacific Northwest believed salmon to be superior beings who ascended rivers for the benefit of people, died, and then returned to life in a great house under the ocean where they danced and feasted in human form. Some tribes welcomed the first salmon of the season with the ceremony due to a visiting chief.
While rivers provided life, they also brought death. Settlement on the plains, which enabled people to take advantage of the rich alluvial soils, also exposed crops and villages to the risk of catastrophic floods. Gilgamesh, the earliest surviving epic tale, tells of a great flood unleashed by God to scourge the sinful in Mesopotamia. Myths and legends of huge floods are common to many cultures around the world, from the Old Testament Jews to the pagan Norse and the indigenous people of the Americas.
The damming of the world has brought a profound change to watersheds. Nothing alters a river as totally as a dam. A reservoir is the antithesis of a river - the essence of a river is that it flows, the essence of a reservoir that it is still. A wild river is dynamic, forever changing - eroding its bed, depositing silt, seeking a new course, bursting its banks, drying up. A dam is monumentally static, it tries to bring a river under control, to regulate its seasonal pattern of floods and low flows. A dam traps sediments and nutrients, alters the river's temperature and chemistry, and upsets the geological processes of erosion and deposition through which the river sculpts the surrounding land. |
