VALIDATION OF CATCHMENT MODELS FOR PREDICTING LAND-USE AND CLIMATE-CHANGE IMPACTS .2. CASE-STUDY FOR A MEDITERRANEAN CATCHMENT

Validation methods commonly used to test catchment models are not capa ble of demonstrating a model's fitness for making predictions for catc hments where the catchment response is not known (including hypothetic al catchments, and future conditions of existing catchments which are subject to land-use or climate change). This paper describes the first use of a new method of validation (Ewen and Parkin, 1996. J. Hydrol., 175: 583-594) designed to address these types of application; the met hod involves making 'blind' predictions of selected hydrological respo nses which are considered important for a particular application. SHET RAN (a physically based, distributed catchment modelling system) is te sted on a small Mediterranean catchment, The test involves quantificat ion of the uncertainty in four predicted features of the catchment res ponse (continuous hydrograph, peak discharge rates, monthly runoff, an d total runoff), and comparison of observations with the predicted ran ges for these features. The results of this test are considered encour aging.