2019 年 13 巻 2 号 p. 34-40
A hydrological model, XAJMISO is adopted from the XinAnJiang (XAJ) model and modified by transforming the parametric routing system into a non-parametric system to reduce parameters and improve performance. The proposed model replaces routing components of the XAJ model with two linear systems: surface flow and subsurface flow, including interflow and baseflow. The discharge at the basin outlet is then calculated using response functions of surface and subsurface flow, which are derived by means of a multiple input single output (MISO) system. In contrast to other MISO studies, the present study defines the finite length for calculating response function coordinates based on time scales of all runoff components. The model is applied to six river basins of different data aridity indices in the United States and compared with our modified XAJ (mXAJ) model. The results reveal that the proposed model sufficiently represents the relationship between rainfall and runoff of relatively large basins and provides better and more stable performance. The proposed model also makes calibration much easier by reducing four sensitive parameters out of seven in mXAJ.