Hydrological Study of Deli River Flood Discharge Using the HSS Nakayasu Model

Abstract The Deli River, in North Sumatra, is often hit by flood disasters, so studies are needed to understand the flood discharge. The aim of this research is to analyze the Deli River flood discharge using the Nakayasu Synthetic Unit Hydrograph (HSS) model. Hydrological data which includes rainfall and water discharge is used as input material to model the response of river flow to rain events in the Deli River area, especially Medan Maimun District, for a period of 2, 5, 10, 25, 50 years from 2014. The results of the study show that discharge the HSS Nakayasu model flood is Q 2 : 383,403 m 3 /sec, Q 5 : 431,259 m³/sec; Q 10 : 461.897 m³/sec; Q 25 : 499.823 m³/sec; Q 50 : 527,620 m³/sec; Q 100 : 555.149 m³/sec.