| Abstract: | A moisture cycle of 1800 to 2000 years has been established for the earth as a whole, and the present period represents a transition from a wet to a dry phase in which the amount of water in oceans is gradually increasing at the expense of water from the land surface. Runoff fluctuations on the land surface also follow cycles of varying duration. It has been established that wet periods in some sections of the earth's surface are always matched by dry periods elsewhere. A definite geographic localization of zones of synchronous and asynchronous runoff fluctuations can be used in long-range runoff forecasts, which are needed for water-budget and waterpower-potential calculations. Prospects for future elimination of the disproportion between water needs and water resources are suggested. Steps to overcome the growing pollution problem are also proposed. |
