(Similarity) Calibration of Rainfall Variety Switching to Discharge with Hec HMS Method at Binalatung Tarakan

The approach to calculating the transfer of rainfall into discharge varies widely. The methods
used to estimate the amount of river flow, such as in the Binalatung watershed, Tarakan City, North
Kalimantan, are based on the assumption that during the rainy season there is excess water available and
during the dry season there is a drought. Methods that can be used include HEC HMS. For HEC-HMS
modeling after calibration, it is located on the rain data during when used from 10 years from 2010 to 2019, the
value of the calibration is 80 and the Initial Abstraction (Ia) value is 0.5 with a correlation coefficient value of
0.85 and has a relative error percentage of 44.8%. The peak discharge from the simulation model after
calibration is 3.0 m3/s and the total volume of outflow is 231836.19 mm.
KEYWORDS: HEC HMS, diversity, rainfall, discharge, runoff.