FLOOD CONTROL STUDY AND REVIEW ON RELIABILITY OF TANGGUL RIVER CAPACITY IN JEMBER REGENCY EAST JAVA PROVINCE

• Main Author: Giyanto
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/39996
• Institution: Institut Teknologi Bandung

The Tanggul River is one of the main rivers in Jember Regency which experiences floods every year. Major floods have occurred in 2013 resulting in 1,000 residential settlements and 500 ha of farmland inundated with a height of 0.5 to 1.5 m. Various efforts have been made by the local government, but the overflow of flooding continues to this day. The flood discharge load which is increasing every year and the smaller river capacity is thought to be the main cause of flood overflow. In this study, it will analyze the capacity of the Tanggul River in full bank capacity with planned flood discharge Q 2, Q 5, Q 10, Q 20 and Q 25. Furthermore, flood control efforts are carried out with various scenarios, the reliability of existing conditions and the conditions of various river treatment scenarios and economic values and benefits to be obtained. Flood control efforts are carried out structurally with normalization activities, construction of side spillway, normalization and elevation of embankments, normalization and construction of side spillway and normalization, construction of side spillways and elevation of embankments. Hydraulics analysis was carried out with a planned flood discharge Q 25 years to obtain flood water level, area and depth of flood inundation with the HECRAS 1D / 2D version 5.06. Reliability analysis is done by Safety Factor (SF) and First-Order Second Moment (FOSM) methods, while economic analysis and benefits with the Benefit Cost (B / C) Ratio method. The B / C Ratio method is done by comparing the Capital Cost and Benefit obtained from the reduction of flood inundation, while the analysis of flood inundation is done with the QGIS program and data on the Open Street Map (OSM). Based on the results of the study, the capacity of the Tanggul River was obtained by the condition of the full bank capacity at the planned flood discharge of Q 5 years. The recommended Tanggul River control efforts are normalization and elevation activities of embankments with a B / C ratio of 1.7, flood inundation reduction of 62.88%, SF value of 1.07 and reliability index of 97.05%.