ANALISIS DEBIT BANJIR DENGAN METODE HIDROGRAF SATUAN SINTETIK NAKAYASU DAN HIDROGRAF SATUAN SINTETIK SNYDER PADA SUNGAI KOBE KABUPATEN HALMAHERA TENGAH

Abstract

Abstract

Flood is a condition where the water level in a river is higher than the normal water level as long as the flow remains in the river channel, then the flood will not be a problem. unless the flood water level increases and overflows into the surrounding area, it can be a problem for the surrounding area. Floods are a disaster that often occurs in Indonesia. Floods that often occur in North Maluku Province, one of which is in Woekob Village, Kobe River, Central Halmahera Regency. The purpose of this study was to determine the magnitude of the planned flood discharge for a return period of 2 years, 5 years, 10 years, 25 years, 50 years and 100 years using the Nakyasu Synthetic Unit Hydrograph and Snyder Synthetic Unit Hydrograph methods on the Kobe River. The calculation results obtained the planned flood discharge using the Nakayasu Synthetic Unit Hydrograph method with a 2-year return period of 946.8 m3/sec, a 5-year return period of 1729.5 m3/sec, a 10-year return period of 2370.2 m3/sec, a 25-year return period of 3252.9 m3/sec, a 50-year return period of 4025.2 m3/sec and a 100-year return period of 5009.0 m3/sec. The calculation of Snyder Synthetic Unit Hydrograph method, the planned flood discharge obtained a 2-year return period of 61.36 m3 / sec, a 5-year return period of 109.67 m3 / sec, a 10-year return period of 149.21 m3 / sec, a 25-year return period of 203.68 m3 / sec, a 50-year return period of 251.34 m3 / sec and a 100-year return period of 312.05 m3 / sec. From the results that have been obtained, the peak discharge values can be known with the two different methods.

Keywords: Kobe River, Nakayasu, Snyde