Improved error modelling for streamflow forecasting at hourly time steps by splitting hydrographs into rising and falling limbs

Abstract

Following the development of Error Reduction and Representation In Stages (ERRIS) for daily streamflow forecasting, we extend ERRIS to streamflow forecasting at an hourly time step (ERRIS-h). ERRIS applies a staged error model to reduce errors in hydrological simulations and to quantify prediction uncertainty. ERRIS produces probabilistic predictions, and is capable of propagating errors through multiple lead times to generate ensemble traces. In this study, we identify the need to model the residual distribution differently for rising and falling limbs of hydrographs when applying ERRIS to hourly streamflow forecasting. To address this need, ERRIS-h uses different distribution parameters fo..