Synthetic unit‐graphs

Abstract

This paper presents a method, mostly empirical, of deriving synthetic unit‐graphs. It is of assistance in the study and analysis of runoff‐characteristics of drainage‐areas of from 10 to 10,000 square miles for which stream‐flow records may or may not be available. No attempt has been made to eliminate the use or need of judgment and experience in such studies. The “lag” or time from center of mass of rainfall to peak of runoff is the principal drainage‐basin characteristic used in deriving the synthetic unit‐graphs. An approximate method of determining the “lag” is given for use on areas with no stage‐records available. The peak‐rate of the unit‐graph is expressed as a function of the “lag”.