水文学介绍用,英语翻译

1、hydrology水文学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 water them during a drought. w

2、hatever 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 precipitation equaling or exceeding s

3、tream-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 the streams. marcus vitruvius p

4、ollio (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经销声匿迹了。也许史前的人曾发现横贯河流的一堆石 头就能提高水位，足以淹没作为生长野生食用植物源泉的土地，而这样在干旱季节就能给植 物浇水。不论水力学的早期如何，充分的的迹彖表明，建造者们还不懂多少水文学知识。早 期的希腊和罗马文献说明这些人承认海洋是一切水的主耍源泉，但是不能想象降雨量会等于 或超过河道径流量。当时典型的想法是海水从

5、地下流到山脉底部，那儿有一个天然蒸憎器除 去水屮的盐分，水汽通过管道上升到山顶，在那里凝结，并从河流的源头流走。m.v.波利欧 (大约公元前100年)看来就是像我们今天这样认识降水作用最早的人。leonardo da vinci (1452-1519) was the next to suggest a modem view of the hydrologic cycle, but it remained for pierre perrault (16081680) to compare measured rainfall with the estimated flow of the sein

6、e river to show that the stream-flow was about one-sixth of the precipitation. the english astronomer halley (16561742) measured evaporation from a small pan and estimated evaporation from the mediterranean sea from these data. as late as 1921, however, some people still questioned the concept of th

7、e hydrologic cycle达芬奇(1452-1519)是提出水文循环现代观点的第二个人，但一直到p.贝罗特(1608-1680) 才把观测的雨量与估算的塞纳河的径流暈进行比较,说明河川径流暈约为降雨暈的1/6.英国天 文家哈罗(哈雷)从一个小盘子中测得的蒸发量，并且用这一资料估算地中海的蒸发量。然 而直到1921年，有一些人仍然对水文循环的概念表示怀疑。precipitation was measured in india as early as the fourth century b.c., but satisfactory methods for measuring strea

8、m-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 army in 1819, was transferred

9、 to the signal corps in 1870, and finally, in 1891, to a newly organized u.s. weather bureau, renamed the national weather service in 197o.scattered stream-flow measurements were made on the mississippi river as early as 1848, but a systematic program was not started until 188& when the u.s. geo

10、logical 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 flood control, irrigatio

11、n, 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 today's concepts of hydrology date from 1930.印度早在公元前4世纪就测量降水量了，但是令人满意的测量河道流量的方法很迟才得 到发展。公元97年，罗马水利专员福朗堤努斯只按

12、横断面面积估算流量，而不考虑流速。在 美国，有组织地测量降水量是1819年在陆军军医总监领导下开始的，1870年移交给通信兵团， 最后，在1891你那移交给新改组的美国气象局，该局于1970年改名为国家气象局。早在1848 年密西西比河上就进行分散的河道流量测量了，但是，直到1888年美国地质调查局承担这项 工作时，才开始实施系统的观测计划。霍德、米德和谢尔曼等人在20世纪早期刚开始对这一 领域进行探索，因此，在这时期之前，在水文方面没有进行什么定量工作是不足为奇的。大 约从1930年起，由于在防洪、灌溉、土地改良和有关领域中开展了大量活动，第一次为有组 织地研究水文学提供了真正的动力，因为需

13、要更精确的设计资料，这己是十分明显的事了。 大多数现代水文学的概念从1930年就开始有了。2 hydrology in engineering水文学在工程中的应用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 ? what reservoi

14、r 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，水文学主要用于水工建筑物的设计和运行，溢洪道、公

15、路涵洞、或者城市排 水系统会期望有什么样的洪水流量？需要多大的水库库容才能保证干旱季节里有足够的灌溉 水量或城市供水呢？水库、堤坝或其他控制工程对河流洪水流量有什么影响？这些典型的问 题等待水文学家去解答。large organization such as federal and state waler agencies can maintain staffs of hydrologic specialists to analyze their problems, but smaller offices often have insufficient hydrologic work for

16、full-time specialisls. 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 fundamentals of

17、hydrology is an essential part of the civil engineer" s training.像联邦和州辖水利机构这样的大型组织，拥有-批水文专家来分析他们的问题，但较小 的单位往往没有足够的水文工作给专职水文专家做。因此，许多土木工程师们应邀进行临时 的水文研究。这些土木工程师处理的工程和年费用可能比水文专家还多。无论如何，水文学 的基础知识看来是培训土木工程师所必不可少的一部分。3 subject matter of hydrology水文学研究的主要内容hydrology deals with many topics. the subject

18、 matter 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 p

19、rocesses 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 fi-om this determine the hydrologic result to be expected rather, it is necessary to start with a mass of observed fa

20、cts, 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 f

21、or 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.水文学研究很多问题。本书所介绍的主要内容对大致分成两个方面：收集资料和分析方 法。26章研究水文学的基本资料。充足的基本资料是任何一个一门科学所不可少的，水文 学也不例外。事实上，水文现象屮也包含着许多自然过程的

22、复杂特征，用严密的推理来处理 许多水文现象是困难的。人们并不总是能够从基本的自然法则出发，并由此来推求预期的水 文结果。相反，从大量观察的事实出发，分析这些事实，并根据分析建立控制这些事件的系 统模型确实十分必要的。因此，对于没有足够历史资料的特殊疑难地区，水文学家就将陷入 困境。大多数国家有一个或更多的政府机构负责收集资料，重要的是要让学生学会这些资料 是如何收集和刊出的，了解这些资料的精确度的局限性，学会整理分析和校正这些资料的专 门的方法。typical hydrologic problems involve estimates of extremes not observed in a small data sample, hydrologic characteristic at lo