Letโs Not Forget About Long Droughts

Editorsโ Highlights are summaries of recent papers by AGUโs journal editors.
Source: Water Resources Research
In the March 2026 issue of Water Resources Research, Zhang et al. [2026] interrogate conceptual hydrologic modelsโ ability to capture prolonged drought dynamics. The Australian Millennium drought serves as an example in the study. The results are quite sobering because the vast majority of more than 40 models fail. Unfortunately, calibration doesnโt generally help either and might result in massive overfitting. In essence, conceptual models miss deep aquifer storage components and associated hydrodynamic processes leading to a lack of time scales important in drought modeling. The study is a constructive reminder that model parsimony is not necessarily a good thing and that detailed representation of complex physical processes is part of hydrologic sciences.
Citation: Zhang, Z., Fowler, K., & Peel, M. (2026). Can conceptual rainfall-runoff models capture multi-annual storage dynamics? Water Resources Research, 62, e2025WR042226. https://doi.org/10.1029/2025WR042226
โStefan Kollet, Editor, Water Resources Research