The magnitude and frequency of floods are defined regionally for small streams (drainage This report describes the tritium sampling network established by the U.S. Geological Survey. Tritium rainout data are included for 1962 and 1963 precipitation collected at 15 stations in the United States and Puerto Rico.
These data are presented graphically to show seasonal variations and geographic distribution patterns for 1963 tritium rainout. Total tritium rainout during 1963 was considerably higher than it was in previous years. Peak tritium concentrations in late spring or early summer of 1963 were higher by a factor of three or more over concentrations measured in 1962.