ANALISA DEBIT BANJIR RANCANGAN ( STUDI KASUS BENDUNGAN SIDAN )

Abstract

Rivers are a source of life for humans because they have many functions that are very necessary for human life, such as: raw water sources, irrigation needs and hydropower. So dam construction has a very important role in the progress of an area and the development of the surrounding population. In carrying out the construction of the dam body, an analysis of the flood discharge value is certainly required. For this design, it is necessary to calculate a design with a certain return period and based on the level of need. This research aims to determine the planned rain discharge by frequency analysis and planned flood discharge using the Nakayasu Synthetic Unit Hydrograph method. After the analysis is carried out, the largest planned rainfall value is obtained using the Ej method. Rain Gumbel The value of the Nakayasu synthetic unit hydrograph uses the value from the Ej Gumbel method because the value of the planned rain is greater so that the largest planned flood value is obtained for the 7th hour with a return period of 10 years, namely 488.93 m3/sec, for a return period of 25 years, namely 522.12 m3/sec, for the 50 year return period it is 599.02 m3/sec, and for the 100 year return period the planned flood value is 645.59 m3/sec.