UNIFORM FLOOD-FREQUENCY ESTIMATING METHODS FOR FEDERAL AGENCIES

Large‐scale planning for improved flood‐plain management and expanding water‐resources development has made it increasingly important that a consistent approach be adopted for estimating flood frequencies, a major analytical component in studies required in flood‐plain management and, in a larger sense, in river‐basin management. A Federal interagency group has studied the most commonly used methods of flood‐frequency analysis and has compared the results of applying these methods to a selected group of long‐record representative sites in different parts of the country. Based on these comparisons and on other considerations, it is recommended that all government agencies adopt a uniform procedure for flood‐frequency analysis at sites where records are available. The log‐Pearson Type III distribution has been selected as the base method, with provisions for departures from the base method where justified. Continuing study leading toward improvement or revision of methods is recommended. © 1968 by the Chinese Geophysical Society