In this study, the flood discharge from the basin in the design of the stream structure can be analyzed with a high degree of runoff according to the actual data.
However, the actual data on the amount of flood discharge in Korea's small-scale watersheds do not exist or are insufficient, and the analysis of the outflow is difficult. In particular, the application of the flood discharge calculation method in large-scale watersheds tends to result in excessive amount of runoff.
Therefore, this study was carried out to calculate the exact planned flood quantity through application and comparison of the parameters of the unit diagram with the runoff hydrologic curve based on the actual data in the small watershed.
By comparing and reviewing the actual data and the empirical equation, we proposed the synthetic unit diagram and parameter estimation method applicable to the small watershed.
In addition, considering that the concentrated time in the small watershed is in seconds, the time interval of the synthetic unit diagram is adjusted to the very short duration, the amount of flood discharge from small watershed was analyzed.