Bili-Hydrograph discharge or flow is a very
important part in overcoming problems related to
hydrology. Because the flow hydrograph can describe a
time distribution of surface runoff in a measurement
area and determine the diversity of physical
characteristics of the watershed. The presentation of the
flood hydrograph can use the unit hydrograph reduction
method from the measured flood hydrograph if data is
available and use the empirical formula, namely
Synthetic Unit Hydrograph (SUH), which is a
hydrograph based on synthetic watershed parameters.
This study tries to examine the effect of synthetic unit
hydrograph parameters based on the characteristics of
the watershed in the irrigated area of Kiru-kiru, Barru
The research location is in Barru Regency, South
Sulawesi Province, precisely in the Kiru-Kiru River
Basin using daily rainfall data from Mareppang,
Manuba, Mangkoso and Ralla Stations.
Based on the results of the discussion carried out,
the largest difference in flood discharge obtained based
on the Nakayasu SUH and Modified SUH, which is 2.19,
is in the 200-year return period, while the smallest
difference is 0.01, which is in the 2-year return period.
This shows that the Modified Synthetic Unit Hydrograph
method is quite good in determining flood discharge.
Keywords : Hydrograph, Synthetic Unit, Synthetic Unit Hydrograph Nakayasu, Synthetic Unit Modified.