Analysis of Flood Incidents in Manado City due to Rainfall Fluctuations (Case Study of the Tondano Watershed), Indonesia

Background Fluctuating rainfall intensity refers to the fluctuations or variations in the pattern of rainfall intensity over time in a certain area. This encompasses changes in intensity, duration, frequency, and spatial distribution of rainfall intensity occurring within a specific time frame. Objective This study investigates the fluctuation of rainfall and its relationship with flood occurrences in Manado City, particularly in the Tondano Watershed Area (DAS Tondano). Methods Average and maximum rainfall data are utilized to analyze recurring flood patterns. Results The analysis indicates that average rainfall intensity > 21.79 mm and cumulative rainfall > 52.64 mm, maximum rainfall intensity > 64 mm, and cumulative rainfall > 99.10 mm serve as threshold points for the onset of floods in Manado City. Conclusion Recommendations are made for continuous rainfall data collection in the Tondano Watershed area, especially Manado City, to support more effective flood control planning. The conclusions drawn from this analysis provide valuable insights into understanding and addressing flood risks in the region.