Continuous Calibration

Abstract

Generally, event based rainfall–runoff model calibration and verification is a laborious and expensive activity. With the availability of long term continuous flow meter and rainfall data and faster computers and software, models can now be calibrated to a long term flow record spanning from few months to several years. The practice of model calibration for large and complex regional systems is evolving over the years away from the conventional event based two step calibration and verification process to a more efficient single step continuous calibration process. This paper describes and compares the event and continuous calibration methods. It also presents information and comparison of various statistical methods to objectively quantify the goodness-of-fit statistics for model calibration that can be used in continuous calibration. Examples are provided from the Metropolitan Sewer District of Greater Cincinnati (MSDGC) SWMM model which is one of the largest SWMM model in the world.