Publication Details

Category Text Publication
Reference Category Preprints
DOI 10.5194/hess-2024-59
Licence creative commons licence
Title (Primary) Technical note: The Divide and Measure Nonconformity
Author Klotz, D.; Gauch, M.; Kratzert, F.; Nearing, G.; Zscheischler, J. ORCID logo
Source Titel Hydrology and Earth System Sciences Discussions
Year 2024
Department CER
Language englisch
Topic T5 Future Landscapes
Abstract The evaluation of model performance is an essential part of hydrological modeling. However, leveraging the full information that performance criteria provide, requires a deep understanding of their properties. This Technical Note focuses on a rather counterintuitive aspect of the perhaps most widely used hydrological metric, the Nash-Sutcliffe Efficiency (NSE). Specifically, we demonstrate that the overall NSE of a dataset is not bounded by the NSEs of all its partitions. We term this phenomenon the "Divide and Measure Nonconformity". It follows naturally from the definition of the NSE, yet because modelers often subdivide datasets in a non-random way, the resulting behavior can have unintended consequences in practice. In this note we therefore discuss the implications of the "Divide and Measure Nonconformity", examine its empirical and theoretical properties, and provide recommendations for modelers to avoid drawing misleading conclusions.
Persistent UFZ Identifier
Klotz, D., Gauch, M., Kratzert, F., Nearing, G., Zscheischler, J. (2024):
Technical note: The Divide and Measure Nonconformity
Hydrology and Earth System Sciences Discussions 10.5194/hess-2024-59