THE EXPLOITATION OF DYNIA IN A CONCEPTUAL WATER BALANCE MODEL. SHOULD WE CHANGE THE TRADITIONAL PARAMETERIZATION?

Dr.-Ing. Enrique Muñoz
Departamento de Ingeniería Civil, Universidad Católica de la Santísima Concepción, Chile

Abstract

Traditional modeling consists of a single set of parameters representing stable catchment conditions, but in rainfall-runoff modeling experience has shown that one set of calibrated parameters may not yield equally good approximations of all events or for different parts of the observed hydrograph. The General and Dynamic Identifiability Analyses (GIA and DYNIA respectively) help in the identification of conceptual model parameters and structures. In this study, GIA was used to derive a fixed model parameter set while DYNIA to derive time-dependent model parameter series. Five mountainous river basins in south-central Chile were considered for this study. GIA helped in investigating the range of response modes of a hydrological system while DYNIA moreover contributed to better understand the main hydrological processes of the five river basins. Additionally DYNIA helped to investigate predominant processes and their predominance over time and to detect model deficiencies, which can later be incorporated into the model parameterization as time-dependent parameters, resulting in an improvement of the model performance than that which is achieved using a traditional model with a set of single-fixed model parameters.