给水工程英语翻译.doc

Water Supply（给水工程）A supply of water is critical to the survival of life, as we know it.（众所周知，水对生命的生存至关重要。） People need water to drink, animals need water to drink, and plants need water to drink. （人需要水，动物需要水，植物需要水）The basic functions of society require water:（社会的基本功能需要水：）cleaning for public health（公共卫生设施的冲洗）, consumption for industrial processes（工业生产过程耗水）, and cooling for electrical generation（电能生产过程的冷却）. In this lesson, we discuss water supply in terms of:（在这里，我们从两方面讨论水的供给：）1. Groundwater supplies（地下水供给）2. Surface water supplies（地表水供给） Groundwater is an important direct source of supply that is tapped by wells （地下水是通过打井而得到的重要直接供水水源）,as well as a significant indirect source since surface streams are often supplied by subterranean water.（也是有意义的间接供水水源，因为地表水会经常得到地下水的补给） Near the surface of the earth（靠近地表）, in the zone of aeration（在通气层内）, soil pore spaces contain both air and water（土壤颗粒间隙同时包含空气和水）. This zone, which may have zero thickness in swamplands and be several hundred feet thick in mountainous regions, contains three types of moisture（这一地层，其厚度在沼泽地可能为零，在山区则可能厚达数百英尺，蕴涵三种类型的湿气）. After a storm, gravity water is in transit through the larger soil pore spaces（暴雨之后，水在重力的作用下透过土壤中较大的颗粒间隙）. Capillary water is drawn through small pore spaces by capillary action and is available for plant uptake（在较小土壤颗粒缝隙中的水则由于毛细管作用上升而被植物吸收）. Hygroscopic moisture is held in place by molecular forces during all except the driest climatic conditions（在不是最干燥的气候条件下，土壤湿气中的水蒸汽分子会因为分子间引力范氏力而被土壤稳定下来）. Moisture, from the zone of aeration cannot be tapped as a water supply source（地表通气层的湿气不能通过凿井方式作为供水水源）. In the zone of saturation, located below the zone of aeration（位于通气层以下的饱和层）, the soil pores are filled with water（土壤间隙中充满着水）, and this is what we call groundwater（这些水就是通常所称的地下水）. A stratum that contains a substantial（充实的） amount of groundwater is called an aquifer（包含大量地下水的地层称为含水层）. At the surface between the two zones（通气层和含水层相邻的边界）, called the water table or phreatic surface（称为水位线或浅层地下水面）, the hydrostatic pressure in the groundwater is eaual to the atmospheric pressure（地下水静压力与大气压力相等）. An aquifer may extend to great depths（含水层可达相当深度）, but because the weight of overburden material generally closes pore spaces（但因为过多的地层压力会压缩土壤间隙）, little water is found at depths greater than 600m(2000ft)（深度超过600m，即2000英寸，就基本找不到地下水了）. The amount of water that will drain freely from an aquifer is known as specific yield（若向含水层掘井，能够自由出流的水量称为单位产水量）. The flow of water out of a soil can be illustrated using Figure 1（从土壤中流动的水如图1所示）. The flow rate must be proportional to the area through which flow occurs times the velocity（流量与流水面积和速率成正比）, or Q=AvWhere（此式中） Q=flow rate , in m3/sec（流量，单位为m3/s） A=area of porous material through which flow occurs, in m2（渗透性土壤的流水断面，单位为m2） v=superficial velocity, in m/sec（表征流速，单位为m/s） The superficial velocity is of course not the actual velocity of the water in the soil（表征流速当然不是水在土壤中流动的真实速度）, since the volume occupied by the soil solid particles greatly reduces the available area for flow（因为土壤颗粒粒径极大地降低了水流通过的空间）. If a is the area available for flow, then（如果a代表水的流经断面面积，那么） Q=Av=avWhere（此式中） v=actual velocity of water flowing through the soil（水流在土壤中的真实流速） a=area available for flow（水的流经断面面积） Solving for v,（求解v） v=Av/aIf a sample of soil is of some length L, then（如果土壤样品具有一定长度） v=Av/a=AvL/(aL)=v/porosity（v/孔隙率） since the total volume of the soil sample is AL and the volume occupied by the water is aL.（因为总的土壤样品体积为AL，实际的水流动空间则为aL） Water flowing through the soil at a velocity vloses energy（水在以v速度流动的过程中会损失能量）, just as water flowing through a pipeline or an open channel does（这个道理与水在管道或明渠中流动是一样的）. This energy loss per distance traveled is defined as（单位长度的水头损失定义为） energy lose（水头损失）=h/LWhere（此式中） h=energy, measured as elevation of the water table in an unconfined aquifer or as pressure in a confined aquifer, in m（水头，在非承压含水层中，即水位线；在承压含水层中，即压力；单位为m）L=horizontal distance in direction of flow, in m（流水在水平方面上的长度，m） The symbol(delta) simply means “a change in,” as in “a change in length, L.” （符号表示在某一长度方向上出现的一种变化）Thus this equation means that there is a change(loss) of energy, h, as water flows through the soil some distance, L.（这个公式表示的是随着水在土壤间隙中的流动距离L，出现能量上的变化h）In an unconfined aquifer（在非承压含水层）, the drop in the elevation of the water table with distance is the slope of the water table in the direction of flow（沿流动距离下降的水头是一个沿水流方向的水位斜坡）. The elevation of the water surface is the potential energy of the water（水位线的高度表示着水的势能）, and water flows from a higher elevation to a lower elevation（水总是从高处流向低处）, losing energy along the way（沿程损失能量）. Flow through a porous medium such as soil is related to the energy loss using the Darcy equation（水在类似于土壤的多孔性介质中流动时的水头损失按达西公式计算）Q=KA(h/L)Where（上式中） K=coefficient of permeability, in m/day（渗透系数，单位为m/d） A=cross-sectional area, in m2（过流断面面积，单位为m2）The Darcy equation makes intuitive sense（达西公式给人带来的直观感觉是）, in that the flow rate (Q) increases with increasing area (A) through which the flow occurs and with the drop in pressure, h/L（在一定的水量和压力降条件下，过流面积越大，出水流量就越大）. The greater the driving force ( the difference in upstream and downstream pressures), the greater the flow（驱动水的压力差越大指上下含水层间的不同水压，水的流量越大）. The factor, K（系数K）, is the coefficient of permeability（指渗透性系数）, an indirect measure of the ability of a soil sample to transmit water（土壤样品的透水能力间接指标）, can be measured by a permeameter shown in Figure 2（能够通过图2所示的渗透测试仪测得）; it varies dramatically for different soils（不同土壤的渗透系数相差很大）, ranging from about 0.005m/day for clay（粘土仅0.005m/d）to over 5000m/day for gravel（砾石则超过5000m/d）. The coefficient of permeability is measured commonly in the laboratory using permeameters（渗透系数一般在实验室通过渗透测试仪测得）, which consist of a soil sample through which a fluid such as water is forced（渗透测试仪含有一些土壤样品，水在压力作用下通过它们）. The flow rate is measured for a given driving force (difference in pressures) through a known area of soil sample（在已知的过流断面面积下，测定不同驱动压力下水的流量）, and the permeability calculated（然后通过计算得到渗透系数K）specific yield spsifik ji:ld 单位产水量mass curve 累积曲线capital investment 投资recurring natural event ntrl 重现历史事件subterranean sbtreinin 地下的groundwater 地下水surface water 地表水tap tp 开关、龙头；在上开空（导出液体）swampland swmplnd n. 沼泽地；沼泽地带capillary kpilri n. 毛细管 adj. 毛状的,毛细管的hygro- 词头 湿（气），液体hygroscopic ,haigruskpik adj. 易湿的，吸湿的hygroscopic moisture 吸湿水stratum streitm n. 地质学地层，生物学（组织的）层aquifer kwf kwif n.含水层，地下蓄水层saturation ,strein n.饱和 (状态)，浸润，浸透，饱和度hydrostatic ,haidrusttik adj. 静水力学的, 流体静力学的hydrostatic pressure 静水压力water table 1. 地下水位，地下水面，潜水面 2. 【建筑学】泻水台；承雨线脚；飞檐；马路边沟亦作 water-tablePhreatic surface fri(:)tik 地下水（静止）水位，浅层地下水面Superficial sju:pfil adj. 表面的,表观的，浅薄的Porosity p:rsiti n. 多孔性,有孔性,孔隙率Unconfined nknfaind adj. 无约束的，无限制的Permeability ,p:mibiliti n. 弥漫, 渗透 , 渗透性Permea