Print Email Facebook Twitter The influence of the length of the calibration period and observation frequency on predictive uncertainty in time series modeling of groundwater dynamics Title The influence of the length of the calibration period and observation frequency on predictive uncertainty in time series modeling of groundwater dynamics Author van der Spek, J.E. (TU Delft Water Resources) Bakker, M. (TU Delft Structural Integrity & Composites) Date 2017-03-01 Abstract The influence of the length of the calibration period and observation frequency on the predictive uncertainty in time series modeling of groundwater dynamics is investigated. Studied series are from deltaic regions with predominantly shallow groundwater tables in a temperate maritime climate where heads vary due to precipitation and evaporation. Response times vary over a wide range from ∼60 to ∼1200 days. A Transfer Function-Noise model is calibrated with the Markov Chain Monte Carlo method to both synthetic series and measured series of heads. The model fit and uncertainty are evaluated for various calibration periods and observation frequencies. It is often assumed that the required length of the calibration period is related to the response time of the system. In this study, no strong relationship was observed. Results indicate, however, that the required length of the calibration period is related to the decay time of the noise. Furthermore, the length of the calibration period was much more important than the total number of observations. For the measured series, the credible intervals could commonly be reduced to ∼10% of the measured head range and the prediction intervals to ∼50% of the measured head range with calibration periods of 20 years with approximately two observations per month. Subject calibration periodobservation frequencytime series analysisuncertainty To reference this document use: http://resolver.tudelft.nl/uuid:211e9dc4-7332-426a-aa11-9f6749423c9b DOI https://doi.org/10.1002/2016WR019704 ISSN 0043-1397 Source Water Resources Research, 53 (3), 2294-2311 Part of collection Institutional Repository Document type journal article Rights © 2017 J.E. van der Spek, M. Bakker Files PDF Spek_et_al_2017_Water_Res ... search.pdf 2.28 MB Close viewer /islandora/object/uuid:211e9dc4-7332-426a-aa11-9f6749423c9b/datastream/OBJ/view