Tank models for several land utilizations

The purpose of this study is to develop a rainfall-runoff model that can be applied even in regions with scarce watershed and hydrological data, such as emerging countries in Southeast Asia, and that can predict long-term changes in runoff due to future regional development and climate change. Specifically, a distributed rainfall-runoff model was constructed in order to create a model that can reflect the spatiotemporal heterogeneity of rainfall and future land use changes for the Can Don watershed located in the southern part of Vietnam as the target watershed. Furthermore, focusing on the effect of the mesh size of the distributed rainfall-runoff model on the calculated discharge, the models with seven mesh sizes of 450m, 900m, 1800m, 2700m, 3600m, 4500m, and 9000m were constructed, and the rainfall runoff characteristics of models were examined in relation to topographical characteristics expressed by the models. / Based on the obtained data on the basin boundary, elevation, land use, rainfall and runoff discharge of the target watershed, the watershed models and input data for the rainfall-runoff model were generated. At that time, in order to reflect the land use area more accurately in the models, the tank models for each land use such as forest, paddy field, upland, and urban area were introduced to each mesh. As a result of the numerical calculations, it was concluded that the 4500m-mesh model was the most suitable for the Can Don watershed because it took a short calculation time and could appropriately express the discharge waveform, peak discharge, and total discharge for a year.