An Optimization Trial is a simulation type that can identify model parameters which improve the model results compared to observations. Each trial is composed of a Basin Model, Meteorologic Model, and information about the simulation time window and time step. The trial also includes selections for the objective function, search method, and adjustable parameters. Optimization involves automated parameter adjustments so that the alignment between observation and simulated results improves. The objective functions measure the goodness of fit between the simulated results and observed data. In this tutorial, you will learn how HEC-HMS can be used to optimize a model by adjusting unit hydrograph and loss rate parameters.
In this workshop you will set up and compute an Optimization Trial and review results of the trial and make additional trials as necessary. The Mahoning Creek watershed at Punxsutawney, PA is part of the Allegheny River Basin located in western Pennsylvania. The simplified basin model consists of a single Mahoning Cr subbasin with Initial and Constant loss method, Clark Unit Hydrograph transform method and Recession baseflow method, as shown in figure below. The meteorological model employs the Gage Weights precipitation method to interpolate precipitation between three gages.
