Masutani et al. (2006) developed a scale-free global stream-flow network creation method and provided a dataset of stream-flow networks with 11 different scales. The dataset consists of topographic data of individual river basins. Therefore, it is needed to join those individual topographic data into a large topographic map for study areas covering many river basins. In this study, two solutions to process the data will be presented. Sensitivity analysis will be carried out to choose a better solution for processing data for future researches using hydrological models.