Abstract The Soil and Water Assessment Tool (SWAT) model is one of the most extensively used watershed-scale models across the world. In recent years, in order to enhance the potential of SWAT code maintenance and future development, a completely reconstructed version of SWAT, dubbed SWAT+, has been just released. In addition to the new model structure in SWAT+, reservoir operation functions have been added to improve the performance of model simulations. Before conducting watershed-scale model simulations, reservoir functions of SWAT+ were further coupled with the automatic calibration tool, IPEAT, to better consider the interactions among reservoir parameters and the corresponding hydrologic processes. In this study, a total of 123 reservoirs were simulated at daily scale across the contiguous United States (CONUS). A series of reference values of reservoir parameters (total 15) were categorized based on different classifications: (i) reservoir capacity; (ii) reservoir release; (iii) climate conditions; and, (iv) reservoir storage and release. Overall results showed that the performance of reservoir simulations at daily scales is satisfactory by commonly adopted statistical measures. In different scenarios, SfNFD (seasonal flood control drawdown days during non-flood season) (from 5 to 126 days), EfFLD (exclusive flood control drawdown days) (from 0.1 to 2.1 days) and EfFLC (exclusive flood control constant flow) (from 4.8 to 6.5 ha-m) are sensitive parameters and the converged parameter ranges were close to each other but not for other parameters. The recommended parameter ranges may be embedded by varying sources of uncertainty. However, the proposed calibration guidelines provide fast and accessible reference for future SWAT+ studies especially in subjects related to reservoir operations.

中文翻译：

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SWAT+中水库运行功能的开发，用于国家水量和水质评估

摘要 土壤和水评估工具（SWAT）模型是世界上使用最广泛的流域尺度模型之一。近年来，为了增强SWAT代码维护和未来发展的潜力，刚刚发布了一个完全重构的SWAT版本，称为SWAT+。除了 SWAT+ 中的新模型结构外，还添加了油藏操作功能以提高模型模拟的性能。在进行流域尺度模型模拟之前，SWAT+ 的水库功能进一步与自动校准工具 IPEAT 结合，以更好地考虑水库参数与相应水文过程之间的相互作用。在这项研究中，在美国本土 (CONUS) 每天模拟了 123 个水库。一系列储层参数参考值（共15个）根据不同的分类进行分类：（i）储层容量；(ii) 水库泄放；(iii) 气候条件；(iv) 水库储存和释放。总体结果表明，通过常用的统计措施，日尺度储层模拟的性能令人满意。在不同的情景下，SfNFD（非汛期季节性防洪下降天数）（从5到126天）、EfFLD（独占防洪下降天数）（从0.1到2.1天）和EfFLC（独占防洪恒流）（从 4.8 到 6.5 ha-m) 是敏感参数，收敛的参数范围彼此接近，但对于其他参数则不然。推荐的参数范围可能被不同的不确定性来源嵌入。然而，