Study of Flood Risk Assessment on Banyumas and Cilacap District in Downstream Serayu River Basin, Indonesia

https://doi.org/10.5614/jts.2023.30.2.2

Authors

  • Pratita Hana Kirana Master Program of Water Resources Management, Faculty of Civil and Environmental Engineering Institut Teknologi Bandung, Indonesia.
  • Mohammad Farid Center for Coastal and Marine Development, Institute for Innovation and Entrepreneurship Development Institut Teknologi Bandung, Indonesia.
  • Mohammad Bagus Adityawan Center for Coastal and Marine Development, Institute for Innovation and Entrepreneurship Development Institut Teknologi Bandung, Indonesia.
  • Arno Adi Kuntoro Water Resources Engineering and Management Study Program, Faculty of Civil and Environmental Engineering Institut Teknologi Bandung, Indonesia.
  • Widyaningtyas Center for Water Resources Development, Institute for Research and Community Services Institut Teknologi Bandung, Indonesia.

Abstract

Abstract.

Floods due to the Downstream Serayu River overflow inundate agricultural land and houses in parts of Banyumas
and Cilacap district every year. Based on the classification of flood hazard level referring to Chief of BNPB
Regulation Number 2 the Year 2012 on General Guidelines for Assessment of Disaster Risk, some location points
experienced a high level of flood hazard (>1.5 m). The objective of this study is to develop a flood risk map by using
GIS. Flood hazard assessment uses the HEC-RAS 5.0.6 two-dimensional model, verified with field observation data.
The river discharge is obtained from hydrological calculations, while the tidal component is obtained using
MATLAB-LP Tides BIG. River geometry uses river cross-section from field measurement data for hydraulic
modeling combined with MERIT DEM as its banks. The capacity level also refers to the BNPB Number 2 the Year
2012. In this study, BNPB and PUPR parameters are used. The vulnerability component refers to a 2014 study from
the Ministry of Public Work and Housing (PUPR) Indonesia. The 50-year flood return period shows that the total
area of risk flooded areas in the Downstream Serayu River Basin is 6.22 km2, while high-risk flooded areas are 2.2 km2.


Keywords: Flood risk, HEC-RAS 2D, GIS, MATLAB–LP Tides BIG, MERIT DEM


Abstrak.

Banjir akibat luapan Sungai Serayu Hilir setiap tahun menggenangi lahan pertanian dan perumahan di sebagian
wilayah Kabupaten Banyumas dan Cilacap. Berdasarkan klasifikasi tingkat bahaya banjir mengacu pada
Peraturan Kepala BNPB Nomor 2 Tahun 2012 tentang Pedoman Umum Pengkajian Risiko Bencana, beberapa titik
lokasi mengalami tingkat bahaya banjir tinggi (>1,5 m). Tujuan dari penelitian ini yaitu mengembangkan peta
risiko banjir dengan menggunakan SIG. Pemodelan banjir menggunakan model dua dimensi HECRAS 5.0.6, yang
diverifikasi dengan data observasi lapangan. Debit sungai diperoleh dari perhitungan hidrologi, sedangkan
komponen pasang surut diperoleh dari perhitungan menggunakan MATLAB-LP Tides BIG. Geometri sungai
menggunakan penampang sungai dari data pengukuran lapangan untuk pemodelan hidrolik yang dikombinasikan
dengan MERIT DEM sebagai bantarannya. Tingkat kapasitas juga mengacu pada Peraturan Kepala BNPB Nomor
2 Tahun 2012. Dalam penelitian ini digunakan parameter BNPB dan PUPR. Komponen kerentanan mengacu pada
studi tahun 2014 dari Kementerian Pekerjaan Umum dan Perumahan Rakyat (PUPR) Indonesia. Periode ulang
banjir 50 tahun menunjukkan bahwa total luas area yang berisiko banjir di DAS Serayu Hilir sebesar 6,22 km2,
sedangkan area dengan tingkat risiko banjir tinggi sebesar 2,2 km2.


Kata-kata Kunci: Risiko banjir, HEC-RAS 2D, SIG, MATLAB–LP Tides BIG, MERIT DEM

Published

2023-08-25

Issue

Vol. 30 No. 2 (2023): Jurnal Teknik Sipil

Section

Articles
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