A STUDY ON THE IMPACT OF SEDIMENT CONTROL STRUCTURES ON THE MORPHOLOGY OF THE KAWATUNA RIVER IN PALU CITY

• Main Author: Hazmi, Miftah
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/86714
• Institution: Institut Teknologi Bandung

The major earthquake that struck Central Sulawesi on September 28, 2018, triggered debris floods in several locations, including the Kawatuna River in Palu City. This river, a tributary of the Palu River passing through SIS Al Jufrie Airport, is highly susceptible to floods with a high sediment concentration. To mitigate the impact of major floods, the government implemented measures including the construction of a consolidation dam and groundsill in the area before the river flows through SIS Al Jufrie Airport. This study models hydrology and hydraulics under various scenarios, encompassing variations in river length, conditions before and after the intervention, Newtonian and non-Newtonian flow characteristics, and considerations of the Bank Stability Toe Erosion Model (BSTEM). Flood modeling was performed using HEC-RAS 2D software, producing outputs such as flow depth, velocity, inundation area, and flood hazard maps. Meanwhile, sediment transport modeling using HEC-RAS 1D provided results on changes in riverbed elevation and riverbed mass. The study revealed that flood modeling with the entire river length resulted in increased hazard levels. After the implementation of interventions, there was a significant reduction in the extent of extreme flood hazard zones. On the other hand, considering non-Newtonian flows led to a significant increase in the extent of extreme hazard zones due to higher flow viscosity. For sediment transport, modeling the entire river length showed changes in riverbed mass. Following the intervention, the length of degraded river segments decreased, while modeling that incorporated BSTEM showed an increase in riverbed mass changes. Overall, this research provides insights into the influence of various parameters on flood and sediment transport modeling outcomes, which can serve as a basis for decision-making in flood mitigation and management for the Kawatuna River.