ABSTRACT Understanding of rainfall–runoff model performance under non-stationary hydroclimatic conditions is limited. This study compared lumped (IHACRES), semi-distributed (HEC-HMS) and fully-distributed (SWATgrid) hydrological models to determine which most realistically simulates runoff in catchments where non-stationarity in rainfall–runoff relationships exists. The models were calibrated and validated under different hydroclimatic conditions (Average, Wet and Dry) for two heterogeneous catchments in southeast Australia (SEA). SWATgrid realistically simulates runoff in the smaller catchment under most hydroclimatic conditions but fails when the model is calibrated in Dry conditions and validated in Wet. All three models perform poorly in the larger catchment irrespective of hydroclimatic conditions. This highlights the need for more research aimed at improving the ability of hydrological models to realistically incorporate the physical processes causing non-stationarity in rainfall–runoff relationships. Although the study is focussed on SEA, the insights gained are useful for all regions which experience large hydroclimatic variability and multi-year/decadal droughts.

中文翻译：

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非平稳水文气候条件下降雨-径流模型性能评估

摘要 对非平稳水文气候条件下降雨-径流模型性能的理解是有限的。本研究比较了集总 (IHACRES)、半分布 (HEC-HMS) 和完全分布 (SWATgrid) 水文模型，以确定哪种模型最真实地模拟了降雨-径流关系存在非平稳性的流域中的径流。这些模型在澳大利亚东南部 (SEA) 的两个异质流域的不同水文气候条件（平均、湿和干）下进行了校准和验证。SWATgrid 在大多数水文气候条件下真实地模拟了较小集水区的径流，但是当模型在干条件下校准并在湿条件下验证时失败。无论水文气候条件如何，所有三种模型在较大的流域中都表现不佳。这突出表明需要进行更多研究，以提高水文模型的能力，以实际纳入导致降雨-径流关系非平稳的物理过程。尽管该研究侧重于 SEA，但所获得的见解对所有经历过巨大水文气候变化和多年/十年干旱的地区都有用。