The data folder includes 1) physicochemical data compiled from three monitoring programs (Brandenburg State Office for the Environment, LfU; Polish Chief Inspectorate for Environmental Protection, GIOS; and the Leibniz Institute of Freshwater Ecology and Inland Fisheries, IGB), 2) hydrological data from the Global Runoff Data Centre (GRDC), sourced from the German Federal Institute of Hydrology (BAfG) and the Polish Institute of Meteorology and Water Management (IMGW), and 3) meteorological data (air and skin temperature) from the Copernicus Climate Change Service (C3S). Data sources are specified for each record. Preprocessing steps for the dataset compilation, variable names and measurement units are documented in the accompanying metadata and dictionary files.

The spatial extent covers a ~200 km reach of the Oder River between Ratzdorf (Germany) and Szczecin (Poland), one upstream tributary (Lusatian Neisse), and two sidewater canals (Hohensaaten-Friedrichsthaler Wasserstraße and Salveybach).

The code folder includes three R scripts that reproduce the main analyses, figures, and statistical results presented in the manuscript. All scripts were written and tested in R v4.4.2 (R Core Team, 2024) and include instructions for data loading, processing, and full replication of the analyses.