A Simple Moments-Based Estimator That Utilizes Historical and Paleohydrologic Information

Several researchers have shown that the traditional historical weighting procedure described in Bulletin 17B is inefficient and can not fully utilize many types of historical and paleoflood data. The Expected Moments Algorithm (EMA) is a new, simple and efficient method for incorporating historical and paleoflood information in flood frequency analysis. EMA has been shown to be a theoretical and practical improvement over the Bulletin 17B historical method. A computer program called EMFREQ was developed to implement EMA for usage and testing by practitioners. The program is used for flood frequency estimation that includes historical and/or paleohydrologic data. The purpose of this paper is to communicate the EMFREQ computer program to the water-resources community. The purpose of the program, input data requirements, and computational procedures are briefly described. EMFREQ performance is shown for two examples.