Evaluasi Kapasitas Tampang Drainase Kawasan Perumahan Desa Leuhan Kabupaten Aceh Barat

Abstract

Abstrak Banjir yang melanda Desa Leuhan Dusun Raja Ampat kabupaten Aceh Barat disebabkan limpasan air hujan yang mengenangi kawasan setempat. Penyelesaian yang tepat untuk mengatasi banjir kota adalah evaluasi kapasitas penampang drainase. Tujuan penelitian ini untuk mengetahui debit banjir rancangan dan kapasitas penampang drainase. Metode penelitian dilakukan dengan analisis hidrologi dan analisis hidrolika. Hujan rencana dan debit rancangan ditentukan dengan analisis hidrologi. Analisis debit banjir rancangan kala ulang dihitung dengan metode rasional. Kapasitas dan dimensi penampang drainase dihitung berdasarkan analisi hidrolika dengan software HEC-RAS 5.0. Hasil penelitian diperoleh hujan rencana dan debit banjir rencana untuk periode ulang sepuluh tahun yaitu, 259,957 mm dan 712,393 m³/s. Hasil analisis menunjukkan sembilan penampang drainase perlu dilakukan evaluasi. Penampang drainase mengalami luapan disebabkaan oleh ketidakamampuan menampung debit banjir pada saat terjadinya hujan. Setelah dilakukan evaluasi dan perlebaran penampang saluran drainase tinggi luapan mengalami penurunan bahkan tidak terjadi luapan di saluran drainase kawasan perumahan Desa Leuhan. Kata kunci: drainase, analisis frekuensi, debit banjir, Hec-Ras 5.0, Log Person III Abstract Flooding in Leuhan Village, Raja Ampat Hamlet, West Aceh District is caused by rainwater runoff that inundates the local area. The right solution to overcome urban flooding is the evaluation of drainage cross-sectional capacity. The purpose of this study was to determine the design flood discharge and drainage cross-sectional capacity. The research method was conducted with hydrological analysis and hydraulics analysis. Rainfall and design discharge were determined by hydrological analysis. The analysis of the design flood discharge of the return period was calculated by the rational method. The capacity and dimensions of the drainage cross section were calculated based on hydrological analysis with HEC-RAS 5.0 software. The results of the study obtained the rainfall plan and the flood discharge plan for the ten-year return period, namely, 259.957 mm and 712.393 m³/s. The analysis results show that nine drainage cross sections need to be evaluated. The drainage cross section experienced overflow due to the inability to accommodate flood discharge during rainfall. After the evaluation and widening of the drainage channel cross section, the overflow height has decreased and there is no overflow in the drainage channel of the Leuhan Village residential area. Keywords: Drainage, frequency analysis, flood discharge, Hec-Ras 5.0, person log lll

Keywords

• drainage
• frequency analysis
• flood discharge
• hec-ras 5.0
• person log iii