10.4122/1.1000001449 Blaikie, J. Ball, J. E. Loss models - an evaluation of the probability of antecedent rainfall prior to significant rainfall events in Sydney, Australia DTU Library, Technical University of Denmark (DTU) 2005 Losses Rainfall Precipitation Model Sydney API The University of New South Wales, School of Civil and Environmental Engineering en Conference presentation 10.4122/1.1000001450 text/xml 1 A common approach for the assessment of flood risk associated with a proposed development in a flood-prone area is the utilisation of a catchment modelling system. Numerous alternative hydrologic and hydraulic process models have been proposed for inclusion in these systems of process models. In a similar vein, a number of alternative rainfall models for the description of the spatial and temporal variation of rainfall have been proposed. Previous studies such as those by Walsh et al. (1991) and Hill et al. (1996) have shown the importance of the loss model, or the model by which water is removed from rainfall to produce potential surface runoff. While previous studies have indicated the importance of loss models in the estimation of a design flood flow with a pre-defined annual exceedance probability, little information has been developed to assist modellers with the task of converting rainfall of a given annual exceedance probability into flow with the same exceedance probability through the application of catchment modelling systems. Furthermore, even less information has been presented on the magnitude of likely antecedent conditions and the variation of these conditions with the desired annual exceedance probability. Presented in this proposed paper will be an analysis of rainfall across Sydney with the aim of developing the most likely antecedent conditions prior to a rainfall event of a defined annual exceedance probability. It will be shown that these conditions