2024 Volume 80 Issue 16 Article ID: 23-16061
This study aimed to achieve early evacuation by effectively utilizing the issuance of internal flooding hazard information in urban areas to mitigate damages caused by internal flooding. We verified the outflow characteristics of sewer water levels and their predictability. The results revealed that the time difference between peak rainfall intensity and sewer water levels is only about 5-10 minutes. Moreover, it was demonstrated that sewer water levels rise rapidly and may lead to overflowing when reaching full capacity, emphasizing the importance of predicting the time to reach full capacity for each sewer system.Considering the very short evacuation time in small urban catchment areas, we investigated the use of forecasted rainfall to secure evacuation time. The results showed that the rainfall forecast for the next 10 minutes can be utilized effectively. By combining the aforementioned timeframes, we can secure approximately 20 minutes for evacuation. Consequently, we concluded that sewer water level observations are valuable for early evacuation planning.
