Changes in both land use and rainfall patterns can lead to changes in the hydrologic behavior of the watershed. The long-term hydrologic impact analysis (L-THIA) model has been used to predict such changes and analyze the changes in mitigation scenarios. The model is simple as only a small amount of input data are required, but it can predict only the direct runoff and cannot determine the streamflow. This study, therefore, aimed to propose a method for predicting the monthly baseflow while maintaining the simplicity of the model. The monthly baseflows for 20 watersheds in South Korea were estimated under different land use conditions. Calibration of the monthly baseflow prediction method produced values for R² and the Nash–Sutcliffe efficiency (NSE) within the ranges of 0.600–0.817 and 0.504–0.677, respectively; during validation, these values were in the ranges of 0.618–0.786 and 0.567–0.727, respectively. This indicates that the proposed method can reliably predict the monthly baseflow while maintaining the simplicity of the L-THIA model. The proposed model is expected to be applicable to all the various forms of the model.

中文翻译：

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为长期水文影响分析模型建议每月基流估计方法的研究：韩国案例研究

土地利用和降雨模式的变化会导致流域水文行为的变化。长期水文影响分析 (L-THIA) 模型已被用于预测此类变化并分析缓解方案的变化。该模型简单，只需要少量输入数据，但只能预测直接径流，不能确定径流。因此，本研究旨在提出一种在保持模型简单性的同时预测月基流的方法。韩国 20 个流域的月基流是在不同土地利用条件下估算的。月基流预测方法的校准产生了 R ^{2 的}值和纳什-萨特克利夫效率 (NSE) 分别在 0.600-0.817 和 0.504-0.677 范围内；在验证期间，这些值分别在 0.618-0.786 和 0.567-0.727 的范围内。这表明所提出的方法可以可靠地预测月基流，同时保持 L-THIA 模型的简单性。预计所提出的模型将适用于模型的所有各种形式。