@article{3005443, title = "Hydrological post-processing using stacked generalization of quantile regression algorithms: Large-scale application over CONUS", author = "Tyralis, H. and Papacharalampous, G. and Burnetas, A. and Langousis, A.", journal = "Journal of Hydrologic Engineering", year = "2019", volume = "577", publisher = "Elsevier B.V.", issn = "1084-0699", doi = "10.1016/j.jhydrol.2019.123957", keywords = "Climate models; Forecasting; Forestry; Hydrology; Machine learning; Regression analysis, Ensemble learning; Hydrological uncertainty; Interval score; Probabilistic forecasts; Quantile regression, Learning algorithms, algorithm; forecasting method; hydrological modeling; machine learning; simulation; stacking; uncertainty analysis, United States", abstract = "Post-processing of hydrological model simulations using machine learning algorithms can be applied to quantify the uncertainty of hydrological predictions. Combining multiple diverse machine learning algorithms (referred to as base-learners) using stacked generalization (stacking, i.e. a type of ensemble learning) is considered to improve predictions relative to the base-learners. Here we propose stacking of quantile regression and quantile regression forests. Stacking is performed by minimising the interval score of the quantile predictions provided by the ensemble learner, which is a linear combination of quantile regression and quantile regression forests. The proposed ensemble learner post-processes simulations of the GR4J hydrological model for 511 basins in the contiguous US. We illustrate its significantly improved performance relative to the base-learners used and a less prominent improvement relative to the “hard to beat in practice” equal-weight combiner. © 2019 Elsevier B.V." }