Simulasi aliran bahan rombakan di Gunung Bawakaraeng, Sulawesi Selatan

Abstract

SARI
Aliran bahan rombakan (debris flow) adalah fenomena di mana percampuran air, lumpur, dan kerikil mengalir dengan kecepatan tinggi. Karena aliran debris flow memiliki viskositas dan kecepatan yang tinggi, maka bersifat sangat merusak karena mengangkut material yang dilalui di sepanjang sungai sehingga volume dan energinya semakin meningkat dan dapat merusak rumah, jembatan, dan infrastruktur, dan mengakibatkan korban jiwa. Simulasi numerik penting untuk memastikan bahwa bangunan penahan bekerja secara efisien sebelum dilaksanakan pekerjaan konstruksi seperti dam sabo. Makalah ini menyajikan simulasi numerik dua dimensi dengan menggunakan Kanako, GUI dilengkapi simulator aliran debris, yang memungkinkan visualisasi dengan baik dan mudah. Kanako (ver. 2.0) diterapkan pada studi kasus di Gunung Bawakaraeng, Sulawesi Selatan, Indonesia. Simulasi diuji dalam berbagai kondisi termasuk kasus tanpa dam sabo dan dengan dam sabo seri. Hasil simulasi menunjukkan jika tidak ada dam sabo di Kampung Paragang, Lengkese, dan Raulo berpotensi terlanda debris flow. Over flow dan debris flow dapat ditanggulangi dengan 4 seri dam sabo tipe celah.
Kata kunci: aliran bahan rombakan, pencegahan efektif, simulasi numerik, dam sabo

ABSTRACT
Debris flow is a phenomenon in which a mixture of large quantities of water, mud, and gravel flows down stream in high speed. Due to its high density and velocity, debris flow is very devastating, it carries along every things on its path that increases its volume and energy, hence it can destroy settlements, bridges, infrastructures as well as loss of lives. Numerical simulation is important to ensure that retaining construction works efficiently before sabo dam is built. This paper presents two-dimensional numerical simulations of a debris flow using Kanako, a user-friendly GUI-equipped with debris flow simulator that allows good visualization and easy explanation. Kanako (Ver. 2.0) was applied as to a case study at Bawakaraeng Mountain, south Sulawesi, Indonesia. Simulations were tested in various conditions with and without sabo dams including sabo dam series. The simulation results showed that without sabo dams, Paragang, Lengkese and Raulo are potentially affected by debris flow. Slit sabo dam of 4 series type is the most appropriate construction from being affected by over flow and debris flow.
Keywords: debris flow, effective countermeasure, numerical simulation, sabo dam