Evaluation of the extended applicability of a simulated hydrological Tank model at the Ca River Basin sub-catchments

Abstract

Abstract For the majority of the world, most drainage basins are poorly gauged or simply ungauged. The estimation of the hydrological parameters in sub-catchments of large basins is a very difficult task but is frequently required in hydrological analyses. Estimating runoff from ungauged or sparsely gauged catchments is a serious challenge in developing countries like Vietnam. The Ca River Basin is the most extensive system in the North Central region of Vietnam but contains very limited hydrological gauging stations. Therefore, this study aims to investigate the extended applicability of a simulated hydrological Tank model at the Ca River Basin sub-catchments. The daily Tank model was calibrated in gauged sub-catchments: Quy Chau in northern-side and Hoa Quan in southern-side sub-catchments. The extended applicability of calibrated parameter sets was verified by data from the continuously gauged stations of Nghia Khanh, Dua, and Yen Thuong. According to the findings of this study, the use of parameters identified in small sub-catchments can be used to calculate the flow processes in similar, but larger catchments in the Ca River Basin. The simulated Tank model parameters can be applied to calculate discharge at ungauged locations within the study area for a variety of purposes.