UNIT-HYDROGRAPH AND EFFECTIVE PRECIPITATION IDENTIFICATION

A recently proposed method for calibrating lumped rainfall-runoff mode ls, called FDTF-ERUHDIT, is analysed and evaluated on synthetic data. Based on the Unit Hydrograph concept this method performs a simultaneo us identification of the excess rainfall se;ies and the transfer funct ion or unit hydrograph through an alternating iterative procedure with out presuming any runoff production model or applying any arbitrary ba seflow removal. A general evaluation framework was built to allow for generation of realistic data both error-free and contaminated with con trolled errors. The problems of the method's convergence and sensitivi ty to errors in the data and the model structure assumed are tackled. A rather exhaustive series of tests involve also evaluations of the ef fects of a priori choices of optimisation algorithms and their paramet ers, as well as assessments of sampling effects. Combinations of these factors are also tested. Finally, useful guidelines for practical use of the new identification approach are derived.