水利水电工程专业英语河流工程篇.docx

1、水利水电工程专业英语河流工程篇水利水电工程专业英语河流工程篇1. Some Problems Related to Alluvial Rivers（1）1. 与冲积河流相关的一些问题（1）Many of the earlier civilizations came into being the fertile valleys of large rivers. Civilizations prospered in the Nile valley in Egypt, along the Tigris and Eupharates rivers in Mesopotamia, along the I

2、ndus River. As early as 4000 B.C. people built dams across the rivers to store water, dug canals for navigation purposes and also to carry water to the fields to produce much-needed food. Together with the problems associated with the irrigation works, these earlier civilizations were confronted wit

3、h the problems of flood control and the Chinese had developed excellent systems of dikes for the protection of inhabited areas against floods.很多早期的文明都孕育在大江大河的肥沃的河谷。这些文明繁荣在在埃及尼罗河谷，沿着美索不达米亚的底格里斯河和幼发拉底河，沿着印度河流域。早在公元前4000年，人们就横跨河流修建水坝来蓄水，以航运及将水带到农田以生产更加非常需要的事物为目的而开挖渠道。与同灌溉工程相关的问题一样，这些早期文明也面临着防洪的问题，而中国人则

4、已经发展了防洪保护居住区的优秀堤防体系。Thus, since the dawn of civilization, mankind has faced problems associated with rivers, and solved them to the best of their ability. More complicated problems are encountered in modern times because, with the increase in population, more and more rivers are being harnessed for

5、multipurpose use-flood control, water supply, power generation, irrigation and navigation-for which artificial changes are being made in the water courses. These problems have become complicated because of the fact that rivers and other water courses, in most cases, run through loose material and th

6、e water carries some of this material along with it. The presence of sediment in water also creates problems in the operation of turbines and pumps through with the sediment-laden water flows. Further the money spent in treating the water to remove sediment and make it fit for domestic or industrial

7、 consumption is enormous. Other problems connected with the training and harnessing of rivers carrying sediment also engage the attention of a large number of engineers. In fact if the water courses were to flow through nonerodible material, many of the above problems would not exist.因此，自文明的曙光出现开始时，

8、人类就已经面临着与河流相关的问题，并尽其最大可能解决问题。现代社会则遇到了更加复杂的问题，因为随着人口的增加，越来越多的河流因为多种目的的利用而被开发利用，如防洪、供水、发电、灌溉及航运，河道正被人为地改变。这些问题已经变得复杂因为在大多数情况下，这些河流和其他河道流过松散介质并携带这些材料于其中。水中泥沙的存在也通过含沙水流的流动而为水轮机和水泵的操作带来了问题。而且在处理水流以去除泥沙并使之适合家庭使用以及工业耗水的费用是巨大的。其他与整治和开发利用含沙河流相关的问题也吸引了大量工程师的注意力。事实上，如果河道流过非侵蚀性材料，那么上述的很多问题就不会存在了。The loose nonco

9、hesive material through which a river flows is generally called sediment and the subcommittee on Sediment Terminology of the American Geophysical Union has accepted the following definition given by the New Standard Dictionary:Fragmental material transported by, suspended in, or deposited by water o

10、r air, or accumulated in the beds by other natural agents; any detrital accumulation, such as loess.河流流过的松散的非粘性材料通常被称为沉积物，并且美国地球物理学联合会泥沙术语小组委员会已经接受了新标准词典中给出的如下定义：水流或空气中输运的、悬浮其中或储存于其中的碎屑材料，或者在河床中累积的其他天然材料；任何碎屑积聚，比如黄土。Ordinarily this does not include ice, logs of wood, or organic material floating on

11、the surface. Sediment is also sometimes known as alluvium. That branch of engineering which deals with rivers and canals flowing through loose transportable material (sediment or alluvium) and transporting some of it along with water is called fluvial hydraulics, sediment engineering or alluvial riv

12、er dynamics. These channels or rivers are called alluvial channels or alluvial rivers. 通常这并不包括冰、原木或者在表面漂浮的有机材料。沉积物有时也称为冲积土。处理流过松散可输运材料（沉积物或冲积物）并随着水流携带其中一些材料的河流和渠道的工程分支被称为河流动力学，泥沙工程或冲积河流动力学。这些渠道或河流被称为冲积渠道或冲积河流。Civil engineers associated with water resources development come across various types of pr

13、oblems related to alluvial rivers and channels. Some of these important problems are briefly discussed in the following paragraphs to give the reader a perspective and scope of the field.与水资源开发相关的土木工程遇到与冲积河流和渠道相关的很多种问题。以下各段简要地讨论了这里的一些重要问题，以为读者提供该领域的背景和范围。1.1 Sediment Characteristics1.1 泥沙特性Sediments

14、 are broadly classified as cohesive and noncohesive. Cohesion may far outweigh the influence of the physical characteristics of the individual particles. Noncohesive sediment particles react to fluid forces and their movement is affected by the physical properties of the particles such as size, shap

15、e, density and settling velocity.Also, sediment characteristics may change through chemical or physical reactions.沉积物被广泛地分类为粘滞性和非粘滞性。凝聚力可能远大于的单个颗粒的物理特性的影响。非粘性沉淀颗粒对流体力和其运动的反映由颗粒的物理性质，如大小、形状、密度和沉降速度的影响。同时，沉积物特性可能通过化学或物理反应而变化。1.2 Sediment Transport1.2泥沙输运As water flows through rivers and channels, it c

16、arries with it some sediment. Part of the sediment is dragged or rolled along the bed or is for most of the time in contact with the bed. This is named as bed load. The other part is suspended in water and travels with approximately the same velocity as water. This is called suspended load. The amou

17、nt of sediment carried by the river or channel is one of the most important variables in all sediment problems. The extremely large variation in sediment concentration is an indication of the large number of factors, which influence the sediment transport rate in alluvial streams. In fact the sedime

18、nt transport rate is affected by hydrological as well as hydraulic characteristics.随着水流流过河流和渠道，它便携带泥沙。部分泥沙是沿着河流拖动或滚动，或者大部分时间与河床相接处。这被称为推移质。另外一部分悬浮在水流中并大致以与水流相同的速度移动。这被称为悬移质。河流或渠道所携带的泥沙量是在所有泥沙问题中最重要的变量之一。含沙量的非常大的变化指示着大量因素，这影响着冲积型河流中泥沙输运速度。事实上泥沙输运速度受到水文以及水力特性的影响。1.3 River Channel1.3河道The formation of

19、a natural stream channel is influenced by numerous factors of climate, geology, and geography; the most important being the stream discharge, resistance of the landforms to erosion, geometric configuration, and the properties and amount of the sediment transported. The form and dimensions of such a

20、channel, once established, are relatively invariant unless a major change occurs in one or more of the aforementioned factors. A channel may be eroded into a resistant formation, in which case there may be a continuing tendency toward a shifting of position by erosion and rebuilding of the banks. Th

21、e latter type is most frequently found to be formed in materials previously transported and deposited by the stream, although they may also be formed in materials transported by other means, e.g. winds or glaciers.天然河流河道的行程收到很多因素的影响，如气候、地质和地形；最重要的因素是河流流量，该区地貌的抗侵蚀性，几何构型以及输运的泥沙的特性和数量。该河流的形式和尺寸，一旦建立是相对

22、不变的，除非上述因素中的一个或多个发生重大变化。河道被冲刷可能有两种结果：一种是形成抗冲层，即稳定结构；另一种是河道由易冲物质组成，将不断地被冲刷，其结果是改变河道位置，再造河岸。后面这种类型经常形成于此前由河流输运并储存的材料上，尽管它们也可能在通过其它手段输运的材料而形成，比如风或冰川。1.4 Sediment Transport and River1.4泥沙输运与河流A certain length of an alluvial stream is said to be in regime or in equilibrium, if the amount of sediment comi

23、ng into this reach is equal to the sediment going out from the same; this is also equal to the sediment transport capacity of the stream for given characteristics of sediment, flow and fluid. Hence the stream bed elevation will not change over a long period of time. However, if incoming and outgoing

24、 sediment loads are different, the bed level must either rise or fall. A rise in bed level is known as aggradation, while a fall in bed level is known as degradation. For example, degradation is bound to occur downstream of a large storage reservoir, because most of the sediment is stored in the res

25、ervoir and thus water flowing over the dam is almost clear and, consequently, capable of transporting additional sediment. As such, sediment is picked from the riverbed downstream of the dam and it is never replenished; hence degradation results.如果进入与流出冲击型河流的某一段长度的泥沙相等，那么该段河流被称为是不冲不淤或冲淤平衡。这也与给定泥沙、流量

26、和流体特性的河流的泥沙输运能力相等。因此，在很长一段时间内河床高度不会发生变化。然而，如果泥沙含量的流入和流出不同，河床高度就会或升或降。河床高度的升高被称为淤积，而河床高度的下降被称为冲刷。比如，冲刷势必发生在大型蓄水水库的下游，因为大多数的泥沙被存储在水库中，因此流过大坝的河流几乎为清水，因此，能够输送额外的泥沙。因此，河流从大坝下游河床上拾起泥沙，并且它从不会得到补充；因此就导致了冲刷。2. Some Problems Related to Alluvial Rivers（2）2. 与冲积河流相关的一些问题（2）2.1 Stabilization and Rectification of

27、 Rivers2.1河流的稳定和整治The fundamental thesis underlying stabilization and rectification of rivers is to shape a river into a single channel, following a path of easy bends of reverse curvature, and to fix it permanently on that alignment.Present-day knowledge of hydraulics of rigid boundary open channel

28、s has given adequate tools to design channels with fixed boundary and carrying clear water. However, the design of a channel flowing through alluvial material and carrying sediment along with water is extremely difficult.河流的稳定和整治的基础理论是将河流塑造成一个单一的河道，沿着反向弯曲的容易弯曲的路径，并在该位置上永久地固定。当今刚性边界明渠水力学的知识已经提供了设计有固定

29、边界并承载清水的渠道的适当工具。然而，流过冲积性材料并随着水流携带泥沙的渠道的设计非常困难。2.2 Navigation2.2航运It has been recognized since the early days of civilization that water transport of bulk commodities is much cheaper than ground transport. In order to develop more and more water transport facilities, river channels must be improved s

30、o that they are suitable for navigation. Several rivers in Europe such as the Danube, the Volga, and the Rhine and such rivers as the Mississippi in U.S.A. and the Yangtze in China have been developed and regulated for inland navigation. Inland navigation is also practiced on some of the Indian rive

31、rs in the eastern part of the country. This improvement for navigation is effected by one more of the following processes: canalization, regulation by river training works, providing lateral canals with locks, dredging to deepen the critical sections, and providing storage reservoirs to supplement m

32、inimum flow and increase the water depth. Application of these methods requires a deep insight into hydraulics.自从文明早期，人们就认识到通过水路运输大宗商品要比陆路运输廉价得多。为了开发更多的水运设施，必须改进河道以使其适于航运。欧洲的很多河流，如多瑙河、伏尔加河和莱茵河，美国的密西西比河和中国的长江都被开发和调控作内河航运。内河航运在印度东部的印度河也有实践。下面另一个过程影响了航运的改进：运河化，通过河道整治工程调控，提供锁定的斗渠，疏浚以加深临界断面，并提供蓄水水库以提供最小流

33、量及增加水深。这些方法的应用需要对于水力学的深入洞悉。2.3 Flood Control2.3防洪Rivers, gullies and other streams drain the surplus water of precipitation to the sea. When there is excessive precipitation, the water level in the river rises above the banks and water spills to the low-lying areas. Such situations are called floods