Good morning. This morning we are continuing our look at Australia and its natural problems. Actually dryness, or aridity, as it is generally called by geographers, is probably the most challenging of Australia's natural problems and so it is very important in this course for you to have a good understanding of the subject. For Australia, water is a precious resource and its wise management is of the greatest importance.

As I have said, Australia is a dry continent, second only to Antarctica in its lack of rainfall. Long hours of hot sunshine and scaring winds give Australia an extremely high rate of evaporation, far more than in most other countries. It is estimated that approximately 87% of Australia's rainfall is lost through evaporation, compared with just over 60% in Europe and Africa and 48% in North America. You generally think of Africa as being a very hot and dry place, but it is not in comparison with Australia. In many parts of Australia standing water, that is dams, puddles and so forth, dry up rapidly and some rainfall barely penetrates the soil. The reason for this is that the moisture is absorbed by thirsty plants.