Print Email Facebook Twitter Estimating extreme river discharges in Europe through a Bayesian network Title Estimating extreme river discharges in Europe through a Bayesian network Author Paprotny, D. (TU Delft Hydraulic Structures and Flood Risk) Morales Napoles, O. (TU Delft Hydraulic Structures and Flood Risk) Date 2017-06-02 Abstract Large-scale hydrological modelling of flood hazards requires adequate extreme discharge data. In practise, models based on physics are applied alongside those utilizing only statistical analysis. The former require enormous computational power, while the latter are mostly limited in accuracy and spatial coverage. In this paper we introduce an alternate, statistical approach based on Bayesian networks (BNs), a graphical model for dependent random variables. We use a non-parametric BN to describe the joint distribution of extreme discharges in European rivers and variables representing the geographical characteristics of their catchments. Annual maxima of daily discharges from more than 1800 river gauges (stations with catchment areas ranging from 1.4 to 807 000 km2) were collected, together with information on terrain, land use and local climate. The (conditional) correlations between the variables are modelled through copulas, with the dependency structure defined in the network. The results show that using this method, mean annual maxima and return periods of discharges could be estimated with an accuracy similar to existing studies using physical models for Europe and better than a comparable global statistical model. Performance of the model varies slightly between regions of Europe, but is consistent between different time periods, and remains the same in a split-sample validation. Though discharge prediction under climate change is not the main scope of this paper, the BN was applied to a large domain covering all sizes of rivers in the continent both for present and future climate, as an example. Results show substantial variation in the influence of climate change on river discharges. The model can be used to provide quick estimates of extreme discharges at any location for the purpose of obtaining input information for hydraulic modelling. To reference this document use: http://resolver.tudelft.nl/uuid:11eeb6fa-5269-48ab-a198-4723f121148c DOI https://doi.org/10.5194/hess-21-2615-2017 ISSN 1027-5606 Source Hydrology and Earth System Sciences, 21, 2615-2636 Part of collection Institutional Repository Document type journal article Rights © 2017 D. Paprotny, O. Morales Napoles Files PDF hess_21_2615_2017.pdf 4.93 MB Close viewer /islandora/object/uuid:11eeb6fa-5269-48ab-a198-4723f121148c/datastream/OBJ/view