MITIGASI BANJIR STRUKTURAL MENGGUNAKAN MODEL HEC-RAS DAN GEO-STUDIO PADA WILAYAH SUNGAI TOBA-ASAHAN, SUMATERA UTARA

Rian Mantasa Salve Prastica; Aditya Widyatmoko; Rezky Kurniawan

doi:10.29103/tj.v11i2.519

MITIGASI BANJIR STRUKTURAL MENGGUNAKAN MODEL HEC-RAS DAN GEO-STUDIO PADA WILAYAH SUNGAI TOBA-ASAHAN, SUMATERA UTARA

Rian Mantasa Salve Prastica, Aditya Widyatmoko, Rezky Kurniawan

Abstract

Abstrak

Permasalahan banjir menjadi isu utama di Indonesia dan di dunia. Strategi manajemen pengendalian banjir dapat berupa upaya mitigasi struktural dan non-struktural. Adanya perkembangan penelitian menyebutkan bahwa mitigasi non-struktural memiliki dampak yang baik dalam mereduksi banjir. Penelitian ini mengambil studi kasus di daerah studi yaitu Wilayah Sungai Toba-Asahan, tepatnya di Sungai Silau. Apakah mitigasi struktural dalam pengendalian banjir signifikan? Analisis kapasitas hidrolika menggunakan software HEC-RAS adanya penurunan limpasan banjir dari kondisi eksisting ke kondisi skenario normalisasi sungai. Begitu pula nilai safety factor lereng sungai pada lokasi tinjauan menggunakan software Geo-Studio yang naik sebesar 139%. Opsi usulan desain bendungan urugan juga dapat mereduksi banjir sebesar 24,83%. Sehingga, dapat disimpulkan bahwa mitigasi struktural signifikan dalam pengendalian banjir. Namun, mitigasi struktural tidak bersifat sustainable bagi pemangku kepentingan, sehingga perlu ada skenario simulasi menggunakan mitigasi non-struktural.

Kata kunci: pengendalian banjir, mitigasi struktural, mitigasi non-struktural, flood routing

Abstract

The problem of flooding is a major issue in Indonesia and in the world. Flood control management strategies can take the form of structural and non-structural mitigation measures. The development of research states that non-structural mitigation has a good impact in reducing flooding. This research took a case study in the study area, namely the Toba-Asahan River Basin, to be precise in the Silau River. Is structural mitigation in flood control significant? Analysis of hydraulic capacity using HEC-RAS software shows a decrease in flood runoff from existing conditions to river normalization scenario conditions. Likewise, the river slope safety factor value at the review location using Geo-Studio software increased by 139%. The proposed option for embankment dam design can also reduce flooding by 24.83%. Thus, it can be concluded that structural mitigation is significant in flood control. However, structural mitigation is not sustainable for stakeholders, so there needs to be a simulation scenario using non-structural mitigation.

Keywords: flood management, structural mitigation, non-structural mitigation, flood routing

Keywords

flood management, structural mitigation, non-structural mitigation, flood routing

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DOI: http://dx.doi.org/10.29103/tj.v11i2.519