A NEW METHODOLOGY FOR DERIVING REGIONAL TIME OF CONCENTRATION EQUATIONS USING GIS AND GENETIC PROGRAMMING

摘要

In this study, a methodology is proposed for deriving Time of concentration (ToC) equations for watersheds located in a specific geographic region using GIS and Genetic Programming (GP). In this method, "true" ToC values are calculated by integrating GIS data into the TR-55 model and using the travel time method. GP is then used as a data-mining tool for conducting symbolic regression and deriving the most accurate equations for the region's watersheds. In a case study, the proposed methodology is applied to 72 watersheds and sub-watersheds in Khorasan Razavi province, Iran. The method provides a set of different ToC equations to be used for watersheds in the region. Performance evaluation of the equations mined by GP shows that this approach is able to find ToC equations that are more accurate and robust compared to conventional ToC equations. Also, the derived equations shed some light on the important parameters that influence the ToC of a watershed.