This data repository is associated with the scientific article "Upscaling Tracer-aided Ecohydrological Modeling to Larger Catchments: Implications for Process Representation and Heterogeneity in Landscape Organization" by Yang et al. (submitted to Water Resources Research). This dataset includes the model setup information of the EcH2O-iso model in the Selke catchment, central Germany (./model_setup_Selke), and all model simulations and data analyses that are necessary to rebuilt the work (./model_sim_data). Please also refer to https://github.com/XYang-EcoHydroWQ/EcH2O-iso_largescale for corresponding model source code of the EcH2O-iso model, including modifications for larger-scale modeling.