水利水電工程專(zhuān)業(yè)英語(yǔ)教材

1、 范文范例參考高等學(xué)校水利類(lèi)統(tǒng)編教材水利專(zhuān)業(yè)外語(yǔ)遲道才 周振民 主編上傳人單位：華北水利水電學(xué)院水利系 完美Word格式整理版 目 錄Lesson 1 importance of water 水的重要性2Lesson 2 the Hydrologic Cycle 水循環(huán)4Lesson 3 hydrology 水文學(xué)6Lesson 4 underground water 地下水10Lesson 5 what causes flooding洪水是怎樣形成的14Lesson 6 nature of water pollution 水污染的性質(zhì)17Lesson 7 Planning for water

2、 resources development水資源開(kāi)發(fā)規(guī)劃20Lesson 8 reservoirs 水庫(kù)24Lesson 9 Properties of concrete混凝土的特性28Lesson 10 basic concepts of reinforced concrete鋼筋混凝土基本概念33Lesson 11 dams 壩36Lesson 12 embankment dams 土石壩40Lesson 13 concrete gravity dam on rock foundations 巖基上的混凝土重力壩44Lesson 14 Arch dams 拱壩48Lesson 15 sp

3、illways溢洪道52Lesson 16 design forces 設(shè)計(jì)作用力56Lesson 17 Significance of infiltration and process of infiltration入滲重要性及過(guò)程60Lesson 18 evapotranspiration 騰發(fā)量63Lesson 19 irrigation methods 灌溉方法66Lesson 20 irrigation canals灌溉渠道74Lesson 21 land drainage 耕地排水77Lesson 22 methods of applications of drip irrigat

4、ion systems滴灌系統(tǒng)的應(yīng)用方法81Lesson 23 hydraulic turbines水輪機(jī)84Lesson 24 hydro-electric power 水力發(fā)電88Lesson 25 differential leveling 水準(zhǔn)測(cè)量（微差水準(zhǔn)測(cè)量）94Lesson 26 construction and equipment施工和設(shè)備99Lesson 27 engineering economy in water resources planning水利規(guī)劃中工程經(jīng)濟(jì)102Lesson 28 soil erosion and soil conservation 土壤侵蝕與

5、土壤保持108Lesson 29 groundwater and climate change地下水與氣候變化112Lesson 30 irrigation performance evaluation 灌溉運(yùn)行評(píng)價(jià)115Lesson 31 bidding, bid opening and award of contract招標(biāo)、開(kāi)標(biāo)和授予合同118Lesson 32 how to write a scientific paper如何撰寫(xiě)科技論文121Lesson 1 importance of water 水的重要性Water is best known and most abundant

6、of all chemical compounds occurring in relatively pure form on the earths surface. Oxygen, the most abundant chemical element, is present in combination with hydrogen to the extent of 89 percent in water. Water covers about three fourths of the earth's surface and permeates cracks of much solid

7、land. The Polar Regions (原文polar regions) are overlaid with vast quantities of ice, and the atmosphere of the earth carries water vapor in quantities from 0.1 percent to 2 percent by weight. It has been estimated that the amount of water in the atmosphere above a square mile of land on a mild summer

8、 day is of the order of 50,000 tons.在地球表面以相對(duì)純的形式存在的一切化合物中，水是人們最熟悉的、最豐富的一種化合物。在水中，氧這種最豐富的化學(xué)元素與氫結(jié)合，其含量多達(dá)89%。水覆蓋了地球表面的大約3/4的面積，并充滿(mǎn)了陸地上的許多裂縫。地球的兩極被大量的冰所覆蓋，同時(shí)大氣也挾帶有占其重量0.1%2%的水蒸氣。據(jù)估計(jì)，在溫暖的夏日，每平方英里陸地上空大氣中的水量約為5萬(wàn)噸。All life on earth depends upon water, the principal ingredient of living cells. The use of wat

9、er by man, plants, and animals is universal. Without it there can be no life. Every living thing requires water. Man can go nearly two months without food, but can live only three or four days without water.地球上所有的生命都有賴(lài)于水而存在，水是活細(xì)胞的基本組分（要素）。人類(lèi)、植物和動(dòng)物都得用水。沒(méi)有水就沒(méi)有生命 。每一種生物都需要水。人可以接近兩個(gè)月不吃食物而仍能活著，但不喝水則只能活三四

10、天。In our homes, whether in the city or in the country, water is essential for cleanliness and health. The average American family uses from 65,000 to 75,000 gallons of water per year for various household purposes.在我們的家庭中，無(wú)論是在城市還是農(nóng)村，水對(duì)于衛(wèi)生和健康來(lái)說(shuō)都是必不可少的。美國(guó)家庭的年平均用水量達(dá)6.57.5萬(wàn)加侖。Water can be considered as

11、the principal raw material and the lowest cost raw material from which most of our farm produces is made. It is essential for the growth of crops and animals and is a very important factor in the production of milk and eggs. Animals and poultry, if constantly supplied with running water, will produc

12、e more meat, more milk, and more eggs per pound of food and per hour of labor.水可以被認(rèn)為是最基本的和最廉價(jià)的原料。我們的農(nóng)產(chǎn)品，大部分都是由它構(gòu)成的。水是農(nóng)作物和動(dòng)物生長(zhǎng)的要素，也是奶類(lèi)和蛋類(lèi)生產(chǎn)的一個(gè)很重要的因素。動(dòng)物和家禽，如果用流動(dòng)的水來(lái)喂養(yǎng)，那么每磅飼料和每個(gè)勞動(dòng)小時(shí)會(huì)生產(chǎn)出更多的肉、奶和蛋。For example, apples are 87% water. The trees on which they grow must have watered many times the weight of th

13、e fruit. Potatoes are 75% water. To grow an acre of potatoes tons of water is required. Fish are 80% water. They not only consume water but also must have large volumes of water in which to live. Milk is 88% water. To produce one quart of milk a cow requires from 3.5 to 5.5 quarts of water. Beef is

14、77% water. To produce a pound of beef an animal must drink many times that much water. If there is a shortage of water, there will be a decline in farm production, just as a shortage of steel will cause a decrease in the production of automobiles.例如，蘋(píng)果含87%的水分，蘋(píng)果樹(shù)就必須吸收比蘋(píng)果多許多倍的水分；土豆含75%的水分，那么種植每英畝土豆就需

15、要若干噸水；牛奶含水量為88%，為了生產(chǎn)每夸脫牛奶，母牛需要3.55.5 夸脫的水；牛肉含77%的水，為生產(chǎn)1磅牛肉牛必須飲用許多磅水。如果缺水，就會(huì)使農(nóng)產(chǎn)品減產(chǎn)，就像缺乏鋼會(huì)引起汽車(chē)產(chǎn)量下降一樣。In addition to the direct use of water in our homes and on the farm, there are many indirect ways in which water affects our lives. In manufacturing, generation of electric power, transportation, recre

16、ation, and in many other ways, water plays a very important role.水除了直接為我們的家庭和農(nóng)場(chǎng)利用外，它還以許多間接的方式對(duì)我們的生活產(chǎn)生影響。在制造、發(fā)電、運(yùn)輸、娛樂(lè)以及其他許多行業(yè)，水都起著很重要的作用。Our use of water is increasing rapidly with our growing population. Already there are acute shortages of both surface and underground waters in many locations. Care

17、less pollution and contamination of our streams, lakes, and underground sources has greatly impaired the quality of the water which we do have available. It is therefore of utmost importance for our future that good conservation and sanitary measures be practiced by everyone.我們對(duì)水的利用隨人口的增長(zhǎng)而迅速增加。在許多地方

18、，無(wú)論地面水或地下水都已經(jīng)嚴(yán)重短缺了。由于任意污染河流、湖泊和地下水源，已經(jīng)大大地?fù)p害了人們能夠利用的水的水質(zhì)。因此，人人有責(zé)對(duì)水采取保護(hù)措施和衛(wèi)生措施，這對(duì)于我們?nèi)祟?lèi)的未來(lái)是極端重要的。Lesson 2 the Hydrologic Cycle 水循環(huán)In nature, water is constantly changing from one state to another. The heat of the sun evaporates water from land and water surfaces, this water vapor (a gas), being lighter

19、 than air, rises until it reaches the cold upper air where it condenses into clouds. Clouds drift around according to the direction of the wind until they strike a colder atmosphere. At this point the water further condenses and falls to the earth as rain, sleet, or snow, thus completing the hydrolo

20、gic cycle.在自然界中，水總是不斷地從一種狀態(tài)改變成另一種狀態(tài)。太陽(yáng)熱使陸地和水面上的水蒸氣。這些水蒸氣（一種氣體）由于比空氣輕，會(huì)上升直至達(dá)到高空冷氣層，并在那里凝結(jié)成云。云層隨風(fēng)飄蕩，直至遇到更冷的大氣層為止。此時(shí)水便進(jìn)一步冷凝，并以雨、雹或雪的形式落到地面。這樣便完成了水的循環(huán)。The complete hydrologic cycle, however, is much more complex. The atmosphere gains water vapor by evaporation not only from the oceans but also from lake

21、s, rivers, and other water bodies, and from moist ground surfaces. Water vapor is also gained by sublimation from snowfields and by transpiration from vegetation and trees.然而，完整的水循環(huán)要復(fù)雜得多。由于蒸發(fā)作用，大氣不僅從海洋而且從湖泊、河流和其他水體，以及從潮濕的地表面獲得水蒸氣。也可從雪地中雪的升華和從植物與樹(shù)木的蒸騰獲得水蒸氣。Water precipitation may follow various route

22、s. Much of the precipitation from the atmosphere falls directly on the oceans. Of the water that does fall over land areas, some is caught by vegetation or evaporates before reaching the ground, some is locked up in snowfields or ice-fields for periods ranging from a season to many thousands of year

23、s, and some is retarded by storage in reservoirs, in the ground, in chemical compounds, and in vegetation and animal life.降水可以有各種不同的途徑。大部分降水都直接落到海洋。落在陸地區(qū)域內(nèi)的水，有些被植物所攝取，或降至地面之前就蒸發(fā)了；有些被封凍在雪原或冰川中達(dá)一個(gè)季度乃至成千上萬(wàn)年；有些則因儲(chǔ)存在水庫(kù)、土壤、化合物以及動(dòng)植物體內(nèi)而滯留下來(lái)。The water that falls on land areas may return immediately to the se

24、a as runoff in streams and rivers or when snow melts in warmer seasons. When the water does not run off immediately it percolates into the soil. Some of this groundwater is taken up by the roots of vegetation and some of it flows through the subsoil into rivers, lakes, and oceans.降到陸地區(qū)域的水可能作為溪流與江河的徑

25、流，或在溫暖季節(jié)融化的雪水直接回到海洋。當(dāng)降水不立即流走時(shí)，它會(huì)滲入土壤。這些地下水中有一些被植物的根吸收，有一些則通過(guò)下層土壤流入河流、湖泊和海洋。Because water is absolutely necessary for sustaining life and is of great importance in industry men have tried in many ways to control the hydrologic cycle to their own advantage. An obvious example is the storage of water b

26、ehind dams in reservoirs, in climates where there are excesses and deficits of precipitation (with respect to water needs) at different times in the year. Another method is the attempt to increase or decrease natural precipitation by injecting particles of dry ice or silver iodide into clouds. This

27、kind of weather modification has had limited success thus far, but many meteorologists believe that a significant control of precipitation can be achieved in the future.因?yàn)樗畬?duì)于維持生命來(lái)說(shuō)絕對(duì)必要，在工業(yè)上也很重要，所以人們?yōu)榱俗陨淼睦嬖噲D以各種方式來(lái)控制水的循環(huán)。一個(gè)明顯的例子就是在一年中不同的時(shí)間根據(jù)當(dāng)?shù)亟邓亩喙眩ò磳?duì)水的需要來(lái)說(shuō)）將水儲(chǔ)存在水庫(kù)中。另一種方法是試圖將干冰或碘化銀微粒射入云層來(lái)增多或減少天然降雨量。雖

28、然這種改造氣候（人工影響天氣）的方法迄今只取得了有限的成功，但許多氣象學(xué)家都認(rèn)為，有效地控制降水在將來(lái)是可以做到的。Other attempts to influence the hydrologic cycle include the contour plowing of sloping farmlands to slow down runoff and permit more water to percolate into the ground, the construction of dikes to prevent floods and so on. The reuse of wate

29、r before it returns to the sea is another common practice. Various water supply systems that obtain their water from rivers may recycle it several times (with purification) before it finally reaches the rivers mouth.其他一些影響水循環(huán)的努力包括沿等高線(xiàn)耕作梯田，以使徑流減速，讓更多的水滲入地下；建筑堤壩以防洪水等。在水回歸大海之前將它重復(fù)使用，也是一種常用的方法。自河道取水的各種供

30、水系統(tǒng)可將水在最終到達(dá)河口之前，經(jīng)過(guò)凈化，可重復(fù)使用多次。Men also attempt to predict the effects of events in the course of the hydrologic cycle. Thus, the meteorologist forecasts the amount and intensity of precipitation in a watershed, and the hydrologist forecasts the volume of runoff.人們還試圖預(yù)測(cè)水循環(huán)過(guò)程中一些事件的結(jié)果。例如，氣象學(xué)家預(yù)報(bào)一個(gè)流域的降雨量和

31、降雨強(qiáng)度；水文學(xué)家預(yù)報(bào)徑流量等。Lesson 3 hydrology 水文學(xué)1 historyThe first hydraulic project has been lost in the mists of prehistory. Perhaps some prehistoric man found that pile of rocks across a stream would raise the water level sufficiently to overflow the land that was the source of his wild food plants and wat

32、er them during a drought. Whatever the early history of hydraulics, abundant evidence exists to show that the builders understood little hydrology. Early Greek and Roman writings indicated that these people could accept the oceans as the ultimate source of all water but could not visualize precipita

33、tion equaling or exceeding stream-flow. Typical of the ideas of the time was a view that seawater moved underground to the base of the mountains. There a natural still desalted water, and the vapor rose through conduits to the mountain tops, where it condensed and escaped at the source springs of th

34、e streams. Marcus Vitruvius Pollio (ca. 100 B. C.) seems to have been one of the first to recognize the role of precipitation as we accept it today.最早的水利工程在有史以前就已經(jīng)銷(xiāo)聲匿跡了。也許史前的人曾發(fā)現(xiàn)橫貫河流的一堆石頭就能提高水位，足以淹沒(méi)作為生長(zhǎng)野生食用植物源泉的土地，而這樣在干旱季節(jié)就能給植物澆水。不論水力學(xué)的早期如何，充分的的跡象表明，建造者們還不懂多少水文學(xué)知識(shí)。早期的希臘和羅馬文獻(xiàn)說(shuō)明這些人承認(rèn)海洋是一切水的主要源泉，但是不能想象

35、降雨量會(huì)等于或超過(guò)河道徑流量。當(dāng)時(shí)典型的想法是海水從地下流到山脈底部，那兒有一個(gè)天然蒸餾器除去水中的鹽分，水汽通過(guò)管道上升到山頂，在那里凝結(jié)，并從河流的源頭流走。M.V.波利歐（大約公元前100年）看來(lái)就是像我們今天這樣認(rèn)識(shí)降水作用最早的人。Leonardo da Vinci (1452-1519) was the next to suggest a modern view of the hydrologic cycle, but it remained for Pierre Perrault (1608-1680) to compare measured rainfall with the

36、estimated flow of the Seine River to show that the stream-flow was about one-sixth of the precipitation. The English astronomer Halley (1656-1742) measured evaporation from a small pan and estimated evaporation from the Mediterranean Sea from these data. As late as 1921, however, some people still q

37、uestioned the concept of the hydrologic cycle.達(dá)芬奇（1452-1519）是提出水文循環(huán)現(xiàn)代觀(guān)點(diǎn)的第二個(gè)人，但一直到P.貝羅特（1608-1680）才把觀(guān)測(cè)的雨量與估算的塞納河的徑流量進(jìn)行比較，說(shuō)明河川徑流量約為降雨量的1/6.英國(guó)天文家哈羅（哈雷）從一個(gè)小盤(pán)子中測(cè)得的蒸發(fā)量，并且用這一資料估算地中海的蒸發(fā)量。然而直到1921年，有一些人仍然對(duì)水文循環(huán)的概念表示懷疑。Precipitation was measured in India as early as the fourth century B.C., but satisfactory me

38、thods for measuring stream-flow were a much later development. Frontinus, water commissioner of Rome in A.D. 97, based estimates of flow on cross-sectional area alone without regard to velocity. In the United States, organized measurement of precipitation started under the Surgeon General of the Arm

39、y in 1819, was transferred to the Signal Corps in 1870, and finally, in 1891, to a newly organized U.S. Weather Bureau, renamed the National Weather Service in 1970.Scattered stream-flow measurements were made on the Mississippi River as early as 1848, but a systematic program was not started until

40、1888, when the U.S. Geological Survey undertook this work. It is not surprising, therefore, that little quantitative work in hydrology was done before the early years of the twentieth century, when men such as Hortan, Mead, and Sherman began to explore the field. The great expansion of activity in f

41、lood control, irrigation, soil conservation, and related fields which began about 1930 gave the first real impetus to organized research in hydrology, as need for more precise design data became evident. Most of todays concepts of hydrology date from 1930. 印度早在公元前4世紀(jì)就測(cè)量降水量了，但是令人滿(mǎn)意的測(cè)量河道流量的方法很遲才得到發(fā)展。公

42、元97年，羅馬水利專(zhuān)員福朗堤努斯只按橫斷面面積估算流量，而不考慮流速。在美國(guó)，有組織地測(cè)量降水量是1819年在陸軍軍醫(yī)總監(jiān)領(lǐng)導(dǎo)下開(kāi)始的，1870年移交給通信兵團(tuán)，最后，在1891你那移交給新改組的美國(guó)氣象局，該局于1970年改名為國(guó)家氣象局。早在1848年密西西比河上就進(jìn)行分散的河道流量測(cè)量了，但是，直到1888年美國(guó)地質(zhì)調(diào)查局承擔(dān)這項(xiàng)工作時(shí)，才開(kāi)始實(shí)施系統(tǒng)的觀(guān)測(cè)計(jì)劃?；舻隆⒚椎潞椭x爾曼等人在20世紀(jì)早期剛開(kāi)始對(duì)這一領(lǐng)域進(jìn)行探索，因此，在這時(shí)期之前，在水文方面沒(méi)有進(jìn)行什么定量工作是不足為奇的。大約從1930年起，由于在防洪、灌溉、土地改良和有關(guān)領(lǐng)域中開(kāi)展了大量活動(dòng)，第一次為有組織地研究水文學(xué)提

43、供了真正的動(dòng)力，因?yàn)樾枰_的設(shè)計(jì)資料，這已是十分明顯的事了。大多數(shù)現(xiàn)代水文學(xué)的概念從1930年就開(kāi)始有了。2 hydrology in engineering水文學(xué)在工程中的應(yīng)用Hydrology is used in engineering mainly in connection with the design and operation of hydraulic structures. What flood flows can be expected at a spillway or highway culvert or in a city drainage system ? Wha

44、t reservoir capacity is required to assure adequate water for irrigation or municipal water supply during droughts? What effects will reservoirs, levees, and other control works exert on flood flows in a stream? These are typical of questions the hydrologist is expected to answer.在工程上，水文學(xué)主要用于水工建筑物的設(shè)

45、計(jì)和運(yùn)行，溢洪道、公路涵洞、或者城市排水系統(tǒng)會(huì)期望有什么樣的洪水流量？需要多大的水庫(kù)庫(kù)容才能保證干旱季節(jié)里有足夠的灌溉水量或城市供水呢？水庫(kù)、堤壩或其他控制工程對(duì)河流洪水流量有什么影響？這些典型的問(wèn)題等待水文學(xué)家去解答。Large organization such as federal and state water agencies can maintain staffs of hydrologic specialists to analyze their problems, but smaller offices often have insufficient hydrologic wo

46、rk for full-time specialists. Hence, many civil engineers are called upon for occasional hydrologic studies. It is probable that these civil engineers deal with a larger number of projects and greater annual dollar volume than the specialists do. In any event, it seems that knowledge of the fundamen

47、tals of hydrology is an essential part of the civil engineers training.像聯(lián)邦和州轄水利機(jī)構(gòu)這樣的大型組織，擁有一批水文專(zhuān)家來(lái)分析他們的問(wèn)題，但較小的單位往往沒(méi)有足夠的水文工作給專(zhuān)職水文專(zhuān)家做。因此，許多土木工程師們應(yīng)邀進(jìn)行臨時(shí)的水文研究。這些土木工程師處理的工程和年費(fèi)用可能比水文專(zhuān)家還多。無(wú)論如何，水文學(xué)的基礎(chǔ)知識(shí)看來(lái)是培訓(xùn)土木工程師所必不可少的一部分。3 subject matter of hydrology水文學(xué)研究的主要內(nèi)容Hydrology deals with many topics. The subject m

48、atter as presented in this book can be broadly classified into two phases: data collection and methods of analysis. Chapter 2 to 6 deals with the basic data of hydrology. Adequate basic data are essential to any science, and hydrology is no exception. In fact, the complex features of the natural pro

49、cesses involved in hydrologic phenomena make it difficult to treat many hydrologic processes by rigorous deductive reasoning. One can not always start with a basic physical law and from this determine the hydrologic result to be expected. Rather, it is necessary to start with a mass of observed fact

50、s, analyze these facts, and from this analysis to establish the systematic pattern that governs these events. Thus, without adequate historical data for the particular problem area, the hydrologist is in a difficult position. Most countries have one or more government agencies with responsibility fo

51、r data collection. It is important that the student learn how these data are collected and published, the limitations on their accuracy, and the proper methods of interpretation and adjustment.水文學(xué)研究很多問(wèn)題。本書(shū)所介紹的主要內(nèi)容可大致分成兩個(gè)方面：收集資料和分析方法。26章研究水文學(xué)的基本資料。充足的基本資料是任何一個(gè)一門(mén)科學(xué)所不可少的，水文學(xué)也不例外。事實(shí)上，水文現(xiàn)象中也包含著許多自然過(guò)程的復(fù)雜特

52、征，用嚴(yán)密的推理來(lái)處理許多水文現(xiàn)象是困難的。人們并不總是能夠從基本的自然法則出發(fā)，并由此來(lái)推求預(yù)期的水文結(jié)果。相反，從大量觀(guān)察的事實(shí)出發(fā)，分析這些事實(shí)，并根據(jù)分析建立控制這些事件的系統(tǒng)模型確實(shí)十分必要的。因此，對(duì)于沒(méi)有足夠歷史資料的特殊疑難地區(qū)，水文學(xué)家就將陷入困境。大多數(shù)國(guó)家有一個(gè)或更多的政府機(jī)構(gòu)負(fù)責(zé)收集資料，重要的是要讓學(xué)生學(xué)會(huì)這些資料是如何收集和刊出的，了解這些資料的精確度的局限性，學(xué)會(huì)整理分析和校正這些資料的專(zhuān)門(mén)的方法。Typical hydrologic problems involve estimates of extremes not observed in a small da

53、ta sample, hydrologic characteristic at locations where no data have been collected (such locations are much more numerous than sites with data), or estimates of the effects of mans actions on the hydrologic characteristics of an area. Generally, each hydrologic problem is unique in that it deals wi

54、th a distinct set of physical conditions within a specific river basin. Hence, quantitative conclusions of one analysis are often not directly transferable to another problem. However, the general solution for most problems can be developed from application of a few relatively basic concepts.典型的水文問(wèn)題

55、包括估算小的數(shù)據(jù)樣本中無(wú)法觀(guān)測(cè)到的極值及估算無(wú)資料地區(qū)（這種地區(qū)比有資料的地區(qū)多得多）的水文特征值，或者估算人類(lèi)活動(dòng)對(duì)該地區(qū)水文特征值的影響。一般來(lái)說(shuō)，每一個(gè)水文問(wèn)題都是不同的，因?yàn)樗婕暗教囟饔騼?nèi)特有的自然條件。因此，某種分析所得的定量結(jié)論常常不能直接移用到另一個(gè)問(wèn)題上。然而，應(yīng)用一些比較基本的概念可以得出大多數(shù)問(wèn)題都適用的一般解決方法。 Lesson 4 underground water 地下水Of all the earths water 97% is found in the oceans, 2% in glaciers and only 1% on land. Of this 1

56、% almost all (97%) is found beneath the surface and called sub-surface or underground water. Most of this water eventually finds its way back to the sea either by underground movement or by rising into surface streams and lakes.地球上的總水量中，97%在海洋，2%在冰川，只有1%在陸地上。陸地上的水幾乎全部（97%）埋藏在地面一下，稱(chēng)為地下水。大部分地下水或通過(guò)地下流動(dòng)

57、，回到海洋；或先進(jìn)入河流或湖泊，最終又回到海洋。These vast underground water deposits provide much needed moisture for dry areas and irrigated districts. Underground water acts in similar ways to surface water, also performing geomorphic work as an agent of gradation.這些廣闊的地下含水層為干旱地區(qū)和灌溉區(qū)域提供了迫切需要的水分。地下水的作用和地表水的作用類(lèi)似，也以均夷作用塑造著

58、地貌。Even though man has been aware of sub-surface water since earliest times, its nature, occurrence, movement and geomorphic significance have remained obscure. Recently, however, some answers have been found to the perplexing questions about underground waters relationship to the hydrological cycle.盡管人類(lèi)自古以來(lái)就知道地下水，但對(duì)它的特性、發(fā)生、運(yùn)動(dòng)和地貌意義還不清楚。然而，近來(lái)關(guān)于地下水和水文循環(huán)關(guān)系的這些錯(cuò)綜復(fù)雜的問(wèn)題已找到了一些答案。1 source of underground water地下水資源Since the days of Vitruvius at the time of Christ, many theories have been presented to explain the large volume of water underneath the earths surface. One theory was that only the