Analysis of Streamline Flow at the Mangalarang-Kajenjeng River Junction

Abstract:

Indonesia faces heightened vulnerability to flooding, making it one of the most frequent natural disasters in the country. In 2020, flood incidents peaked at 1,531, with 1,198 recorded in 2021. Makassar City, in South Sulawesi, experienced severe flooding, particularly at the junction of the Mangalarang and Kajenjeng Rivers, where hydrodynamic interactions exacerbate flood conditions. Nipa-nipa regulation ponds were established to mitigate these issues by focusing on hydraulic behavior during floods. This study examines hydraulic streamline flow at this junction using hydrographic surveys, topographic data, and 2D hydrodynamic simulations via Hec-Ras 6.4. The hydrological analysis incorporates frequency analysis and the Gama synthetic unit hydrograph method, while hydrodynamic modeling adheres to NRCS guidelines, employing a 2D transient flow model for accuracy. Results reveal that the Mangalarang River is the sole source of inflow into the nipa-nipa reservoir spillway, impeding the Kajenjeng River's discharge.

• Periodical: Construction Technologies and Architecture (Volume 16)
• Pages: 3-10
• DOI: https://doi.org/10.4028/p-8iA6X6
• Online since: March 2025
• Authors: Iswandi Utama*, Farouk Maricar, Mukhsan Putra Hatta
• Keywords: Flood Simulation, River Junction, Streamline Flow

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