Regionalization of flood characteristics

Regionalization procedures are used to transfer flood characteristics from gaged to ungaged locations. These procedures are an extension of the gaging network that allows planners and designers to make estimates of flood frequency at ungaged sites of interest. The U.S. Geological Survey has a long time involvement in the development of these regionalization procedures. This paper describes the evolution of these regionalization procedures from the index-flood procedure used in the 1940's to the multiple regression procedure based on generalized least squares that is currently being used.