Making calibration objectives relevant for flood forecasting Available to Purchase

A key requirement of an operational flood forecasting model is to provide a forecast lead time that meets the target flood warning lead time and accuracy standards. This represents a challenge, particularly at higher flood warning thresholds due in part to the limitations imposed by a small flood event sample size. This paper looks at developments in model calibration objectives that are relevant to operational flood forecasting and recommends that lead time analysis of the error-corrected model is included in the model calibration process. Parameter updating based on two effective rainfall loss models optimised on saturated and unsaturated catchments is presented as a novel way of improving the performance of an event-based rainfall–runoff model. Developments are illustrated using an operational flood forecasting model for Taunton in south west England. More work is required to assess the sensitivity of model performance to sample size and to assess the relative priority of multiple calibration objectives if there are conflicting results or if accuracy standards are not defined.