Analysis of bolifar river flood protection in East Seram regency, Indonesia

Abstract

Flood is a natural phenomenon that is destructive, both in terms of material and loss of life. Floods can come from overflowing rivers. One of the rivers that often experience a flood is the Bolifar River located in Maluku Province, Indonesia. This study aims to determine the flood discharge, water level and determine the dimension of the embankment as one of the efforts of flood control. The topography measurement of the Bolifar River is conducted, then obtaining rainfall data, watershed characteristics, and soil mechanics examination. The flood discharge is calculated with Hidrograf Unit Synthetic (HSS) Nakayasu method. The return period Q2Tahun = 341,446 m³ / sec, return period Q5Tahun = 433,956 m³ / sec, return period Q10Tahun = 486,583 m³ / sec, and return period Q20Tahun = 521,211 m³ / sec and with hydraulic calculations resulted in a flood water level of 2.6 meters from the river bed. From the calculation result, the dimension of embankment with h = 2.5 meters, width of the embankment = 4 meters, and the slope ratio of 1: 1.5 where the embankment is planned to be stable against bolsters, stable to the soil support force and the slop stability is quite safe.