水荒是指因来水的随机变化在某一时间内供水严重不足以致影响正常生活及生产的情景。当前，许多国家水资源污染状况的恶化使得用水紧张状况进一步加剧。据联合国环境规划署预测，水的问题将会同70年代的能源一样，成为世界大部分地区面临的最严峻的自然资源问题。联合国有关机构对水资源所进行的监测表明：全球高达十分之一的河流受到了不同程度的污染。世界性的水荒已经开始带来严重后果：全球部分地区已经出现因淡水供应不足而限制了各方面发展的状况。那么，水荒英文怎么说呢？
What is water scarcity
什么是水荒
Water scarcity occurs where there are insufficient water resources to
satisfy long-term average requirements. It refers to long-term water imbalances, combining low water availability with a level of water demand exceeding the supply capacity of the natural system.
Water availability problems frequently appear in areas with low rainfall but also in areas with high population density, intensive irrigation and/or industrial activity. Large spatial and temporal differences in the amount of water available are observed across Europe.
Beyond water quantity, a situation of water scarcity can also emerge from acute water quality issues (e.g. diffuse or point source pollutions) which lead to reduced fresh/clean water availability.
Currently the main way of assessing Water Scarcity is by means of the Water Exploitation Index (WEI) applied on different scales (i.e. national, river basin). The WEI is the average demand for freshwater divided by the long-term average freshwater resources. It illustrates to which extent the total water demand puts pressure on the available water resource in a given territory and points out the territories that have high water demand compared to their resources.
Water scarcity already affects every continent. Around 1.2 billion people, or almost one-fifth of the world’s population, live in areas of physical scarcity, and 500 million people are approaching this situation. Another 1.6 billion people, or almost one quarter of the world’s population, face economic water shortage (where countries lack the necessary infrastructure to take water from rivers and aquifers).
Water scarcity is among the main problems to be faced by many societies and the World in the XXIst century. Water use has been growing at more than twice the rate of population increase in the last century, and, although there is no global water scarcity as such, an increasing number of regions are chronically short of water.
Water scarcity is both a natural and a human-made phenomenon. There is enough freshwater on the planet for six billion people but it is distributed unevenly and too much of it is wasted, polluted and unsustainably managed.
水荒（water scarcity）是指在某些城市，由于天然水源(natural water source)供应无法满足所需用水量或水源受污染无法提供足够清洁水的状况。水荒应当通过如下措施来解决：
1. 建造水库(reservoir)或跨流域调水(inter-basin water transfer)来补给；
2. 改革用水工艺，通过城市污水循环(sewage/waste water reticulating pump)再利用等多种方式来压缩用水量(water consumption)；
3. 开发新技术和利用新水源，如海水淡化(sea water desalinization)、人工降雨(artificial precipitation)等。
