Definitions of Water Use, Conservation, and Efficiency
There is considerable confusion in the water literature about the terms use, need, withdrawal, demand, consumption, and consumptive use. Great care should be used when interpreting or comparing different studies or assumptions about water use. The term water use, while common, can mean many different things, referring at times to consumptive use and at times to withdrawals of water.
Withdrawal usually refers to water removed from a source and used for human needs. Some of this water may be returned to the original source with changes in the quantity and quality of the water, but some may be used consumptively. The term consumptive use or consumption typically refers to water withdrawn from a source and made unavailable for reuse in the same basin, such as through conversion to steam, losses to evaporation, seepage to a saline sink, or contamination. Consumptive use is sometimes referred to as irretrievable or irrecoverable loss(12). Thus a power plant may withdraw substantial amounts of water for cooling from a river but use that permits it to be returned directly to the river, perhaps a bit warmer, for use by the next downstream user, A farmer may withdraw the same amount of water for irrigation, but the vast majority of it may be used consumptively by plants and become unavailable for any other activity.
Need for water is also a subjective term, but typically it refers to the minimum amount of water required to satisfy a particular purpose or requirement. It also sometimes refers to the desire for water on the part of a water user. Demand for water is an economic concept often used to describe the amount of water requested or required by a user(13). T he level of demand for water may have no relationship to the minimum amount of water required to satisfy a particular requirement. Water demand toflushatoiletcanrangefromsixgallonsinanold, ilet, andard,tozerogallonsinanefficientcompostingtoilet.Whatisactuallybeingdemandedisnotaspecificamountofwaterbuttheserviceofreliablyremovingwastes.A considerable number of other confusing terms have appeared in the water literature in the past few years. Among them are terms used to describe the kinds of water that might be saved by changes in technology and water policies, including
Definitions of Water Use, Conservation, and Efficiency
There is considerable confusion in the water literature about the terms use, need, withdrawal, demand, consumption, and consumptive use。 Great care should be used when interpreting or comparing different studies or assumptions about water us...全部
Definitions of Water Use, Conservation, and Efficiency
There is considerable confusion in the water literature about the terms use, need, withdrawal, demand, consumption, and consumptive use。
Great care should be used when interpreting or comparing different studies or assumptions about water use。
The term water use, while common, can mean many different things, referring at times to consumptive use and at times to withdrawals of water。
水的用途，保护和效率之定义
在有关水的著作中，术语的使用常常会混淆，如需要，提取，需求，消耗和消耗的。在翻译或比较关于水用途的不同学科或设想时，应引起高度注意。水这个术语，尽管很平常，但却有很多不同的涵义，有时指消耗，有时却水的回收。
Withdrawal usually refers to water removed from a source and used for human needs。 Some of this water may be returned to the original source with changes in the quantity and quality of the water, but some may be used consumptively。
The term consumptive use or consumption typically refers to water withdrawn from a source and made unavailable for reuse in the same basin, such as through conversion to steam, losses to evaporation, seepage to a saline sink, or contamination。
Consumptive use is sometimes referred to as irretrievable or irrecoverable loss(12)。
回收水通常指那些从一个水源地移走，且供人类使用的水。
这种水有些经过水量和水质的处理，重新回到原来的水源地，有一些则被消耗掉了。术语“消耗用途”或“消耗”主要指从水源地提取，无法在同一水池再利用的水，导致的原因是水变为蒸气，蒸发损失，盐池渗漏或者污染。
消耗用途有时也指不可挽回的损失。
Thus a power plant may withdraw substantial amounts of water for cooling from a river but use that permits it to be returned directly to the river, perhaps a bit warmer, for use by the next downstream user, A farmer may withdraw the same amount of water for irrigation, but the vast majority of it may be used consumptively by plants and become unavailable for any other activity。
例如，电厂可以从江河里提取大量的水用于冷却，而不是使用，这样就允许水直接返回到江河里，也许水温稍稍有点热，但可供下游的用户使用。农民可能提取相同的水量用于灌溉，但是大部分水被电厂消耗掉，无法用于其它活动。
Need for water is also a subjective term, but typically it refers to the minimum amount of water required to satisfy a particular purpose or requirement。
It also sometimes refers to the desire for water on the part of a water user。 Demand for water is an economic concept often used to describe the amount of water requested or required by a user(13)。
水的需要也是个主观术语，它主要是指满足特殊用途或需求的最小用水量。对于水的用户，它有时也指对水的渴望。水的需求是个经济概念，通常用于描述水的用户需要或申请的水量。
Thelevelofdemandforwatermayhavenorelationshiptotheminimumamountofwaterrequiredtosatisfyaparticularrequirement。
Waterdemandtoflushatoiletcanrangefromsixgallonsinanold, ilet, andard,tozerogallonsinanefficientcompostingtoilet。
Whatisactuallybeingdemandedisnotaspecificamountofwaterbuttheserviceofreliablyremovingwastes。水的需求水平与满足特殊要求所用的最小用水量无关。
冲洗厕所的用水量，对于老式的效率很低的美国厕所，用量为6加仑，对于符合现代美国标准的厕所，则为1。6加仑，对于高效综合厕所，用量为0。加仑。需要精确的不是详细的水量而是可靠的处理废水的服务。
A considerable number of other confusing terms have appeared in the water literature in the past few years。
Among them are terms used to describe the kinds of water that might be saved by changes in technology and water policies, including
在过去的几年中，有关水的著作里还有许多其它术语被混淆。
其中有用来描述水的种类，在科技和水政策中经常使用的术语，包括。收起
