A riverbed that remains dry except during the rainy seasons.

Water contact diseases

Water contact diseases acquired through swimming or wading in freshwater lakes, streams, and rivers.


In attempting to control water for the generation of electricity or a gravity flow irrigation project, it is essential to pond up water in relative quantity so that there is an adequate force – Waterhead – to achieve the desired goal.


Physical and chemical processes that change rock characteristics on or near the earth’s surface, occurring slowly over many years.

Welfare system

Welfare system: the way a government organizes assistance to its people, particularly the young, the elderly, the sick, and the unemployed.

Western Wall

For jews, the holiest site in Jerusalem. The only remaining portion of the second temple, built in 538 B.C. And destroyed in a.d. 70 By the Romans.


Workforce: all the people available to work in a country; all the workers employed by a particular factory or place of work.