Match these paragraph headings with the paragraphs below.

1 ………………………………….
Many of the environmental problems facing the world today are water related. Sometimes the problem is that there is too much water (flooding). Other times there is a problem of insufficient water (scarcity).

2 …………………………………….
Defining the term 'water scarcity' is no easy task because its meaning changes according to numerous factors including location, causes and effects. For most of us, water scarcity refers to a situation where there is insufficient water to meet the requirements. Depending on the place, of course, the requirements are greater or smaller and the effects of scarcity more or less serious.

3 ……………………………………………….
Water authorities around the world classify scarcity into different degrees. The most common are:

• Absolute
• Life threatening
• Seasonal
• Temporary
• Cyclical

4 …………………………………………………….
Water policy makers have come up with four terms to help us understand the grade of scarcity implied in any particular problem:

Water shortage is used to refer to a situation where the minimum requirements of water are unable to be met because there are insufficient supplies. The minimum requirements will differ from place to place and from time to time.

Water scarcity refers to the demand for and availability of water. Demands vary within countries and between countries. Industrialised regions dependent on water for energy or irrigation experience times of scarcity more than regions with similar water reserves but with fewer demands. Also, some African countries considered to be suffering from water shortage might not necessarily be classified as having a scarcity of water because their demands are fewer as there is little industry or irrigation.

Water stress refers to what is normally termed drought. The term describes the consequences of water scarcity such as a decline in services, crop failure, etc.

Water security refers to a reliable access to water supplies over a period of time. Water needs are predicted and measures are taken to ensure that the supplies of water are sufficient to deal with these needs.

5 ……………………………………………..
In most cases annual average figures of water requirements and availability are drawn up in each country. This can sometimes present problems because it does not allow for seasonal variability nor for variability within areas of a country. By examining the requirements in relation to the availability, scientists are first able to recognise the existence of water scarcity and then calculate its degree.

6 …………………………………………….
There are many different causes of water scarcity and sometimes these causes are inter-related and difficult to define. Natural causes might include climatic change and variability. Human activity can also bring about serious problems of water scarcity. This includes such things as population growth, land use, economic policy and water resource management.

Develop your vocabulary - do you know these words?