The potential of data assimilation methods for modellinggroundwater flow systems: review and synthetic examples

摘要

A brief literature review on Ensemble Kalman filtering methods is given. In particular,applications where internal parameters together with states were estimated, are discussed. These applicationsare especially found in the petroleum engineering literature, while in meteorology, surface water hydrologyand models for land–atmosphere interaction, almost exclusively initial conditions are updated, withoutadapting internal parameters. A synthetic example illustrates the application of Ensemble Kalman filteringmethods in groundwater hydrology. In cases where only the recharge rate was uncertain, no filter inbreedingwas observed, although the number of realizations was small. In cases where the strongly heterogeneoustransmissivity field was uncertain, up to 500 realisations were needed to avoid filter inbreeding, but in thatcase, states and parameters could be successfully jointly updated and improved. For the case with anunknown spatio-temporal variable recharge rate, a high monitoring frequency reduced the error morestrongly than a dense network, while for an unknown spatial transmissivity the opposite was the case.