ANALISIS HIDROLIKA PELIMPAH GOLENG DAN SWD 1 DALAM PENGENDALIAN DEBIT BANJIR SUNGAI WULAN
Abstract
ABSTRACT
Flood control in the coastal areas of Central Java, particularly along the SWD 1 Channel and the Goleng Spillway, faces significant hydraulic challenges due to sedimentation and land-use changes. This study aims to evaluate the hydraulic capacity of the Goleng Spillway and the SWD 1 Channel in reducing the Q25 flood discharge from the Wulan River, as well as to identify critical overflow points and effective mitigation scenarios. Hydraulic simulations were conducted using the HEC-RAS software under three scenarios: (1) inflow from the Goleng Spillway, (2) local flooding within the SWD 1 watershed, and (3) a combination of both. Input parameters included the Q25 design discharge, DEM-based topography, and cross-sectional channel geometry. The simulation results indicate that several cross-sections (from STA 0+025 to STA 31+000) are unable to accommodate the Q25 discharge effectively, with water surface elevations ranging from 1.18 to 7.9 meters. The most critical condition occurs along the left bank of SWD 1 due to the absence of embankment elevation. While the normalization design improved flow capacity, it was insufficient to manage the combined extreme inflows. Integrated structural interventions, such as elevating the left embankment and optimizing spillway geometry, are recommended to enhance flood resilience in the lower Wulan River region.
Keywords: SWD 1, Goleng Spillway, flood, Q25, HEC-RAS, embankment, hydraulics.
ABSTRAK
Pengendalian banjir di wilayah pesisir Jawa Tengah, khususnya di Sungai SWD 1 dan Pelimpah Goleng, menghadapi tantangan kapasitas hidrolika akibat sedimentasi dan perubahan tata guna lahan. Penelitian ini bertujuan untuk mengevaluasi kapasitas hidrolik Pelimpah Goleng dan Saluran SWD 1 dalam mereduksi debit banjir Q25 Sungai Wulan, serta mengidentifikasi titik-titik kritis luapan dan skenario mitigasi efektif. Simulasi hidrolika dilakukan menggunakan perangkat lunak HEC-RAS dengan tiga skenario: (1) inflow dari Pelimpah Goleng, (2) banjir lokal DAS SWD 1, dan (3) kombinasi keduanya. Parameter input meliputi debit desain Q25, topografi DEM, dan geometri penampang saluran. Hasil simulasi menunjukkan bahwa beberapa penampang (STA 0+025 hingga STA 31+000) tidak mampu menampung debit Q25 secara optimal, dengan muka air mencapai 1,18–7,9 m. Kondisi paling kritis terjadi pada sisi kiri SWD 1 akibat ketiadaan peninggian tanggul. Desain normalisasi terbukti meningkatkan kapasitas, tetapi tidak cukup mengatasi kombinasi inflow ekstrem. Intervensi struktural terintegrasi, seperti peninggian tanggul kiri dan optimalisasi geometri pelimpah, disarankan untuk memperkuat ketahanan banjir wilayah hilir Sungai Wulan.
Kata Kunci: SWD 1, Pelimpah Goleng, banjir, Q25, HEC-RAS, tanggul, hidrolika.
Full Text:
Full PaperReferences
Al Amin, M. B., Ilmiaty, R. S., & Marlina, A. (2023). Flood Hazard Mapping in Residential Area Using Hydrodynamic Model HEC RAS 5.0. Geoplanning: Journal of Geomatics and Planning
Annis, A., Nardi, F., Volpi, E., & Fiori, A. (2020). Quantifying the relative impact of hydrological and hydraulic modelling parameterizations on uncertainty of inundation maps. Hydrological Sciences Journal, 65(4), 507-523.
Bennett, W. G., Karunarathna, H., Xuan, Y., Kusuma, M. S., Farid, M., Kuntoro, A. A., ... & Amaratunga, D. (2023). Modelling compound flooding: a case study from Jakarta, Indonesia. Natural Hazards, 118(1), 277-305.
Cook, A. C. (2008). Comparison of one dimensional HEC RAS with two dimensional FESWMS model in flood inundation mapping (Master’s thesis). Purdue University.
Eldi, E. (2020). Analisis Penyebab Banjir di DKI Jakarta. Jurnal Inovasi Penelitian.
Fadlilla, L. N., Marfai, M. A., & Widyastuti, M. (2020). Studi morfodinamika delta Wulan akibat proses angkutan sedimen dan hidrodinamik di Demak, Jawa Tengah [Disertasi]. UGM
Fang, G., Yuan, Y., Gao, Y., Huang, X., & Guo, Y. (2018). the effects of urbanization on flood events with urban agglomeration polders type of flood control pattern using the HEC-HMS model in the Qinhuai Rive Water.
Harifa, A. C., Purnomo, F., & Sutikno, S. (2022). Flood model of downstream Kali Lahar using HEC RAS. Reka Buana: Jurnal Ilmiah Teknik Sipil dan Kimia, 7(1), 41–62.
Hirabayashi, Y., Kanae, S., Emori, S., Oki, T.,(2008). Global projections of changing risks of floods and droughts in a changing climate.
Juliastuti, Y., Wijayanti, Y., Fajar, M., & Anda, M. (2023). Hydraulic Modeling-Based Design of Retaining Wall Height for Flood Mitigation (Bekasi River, Jakarta). Journal of Engineering and Sustainable Development.
Kay Leng, S. T., Jaafar, M., et al. (2021). Developing flood hazard maps for the Kelantan floodplain using the HEC RAS 2D model. Geografia Malaysian Journal of Society and Space.
Lintang, N. F., et al. (2019). Respon Muara Sungai Wulan Akibat Hidrodinamika Dan Aspek Fisik Di Delta Wulan Kabupaten Demak Jawa Tengah [Tesis S2]. UGM.
Madi, N., et al. (2023). Flood modeling using HEC RAS 2D and IBER 2D: a comparative study. Water Supply, 24(9), 3061 3074.
Manurung, J. G., Suryoputro, A. A. D., & Hariadi. (2020). Analisis pengaruh pasang surut terhadap sebaran muatan padatan tersuspensi di sekitar perairan muara Sungai Wulan, Kabupaten Demak, Jawa Tengah. Journal of Oceanography.
Malindo, N. S., Widiadana, I. B., & Santoso, A. (2024). Optimizing spillway and embankment design for flood control along the Ciliwung River, Jakarta. Indonesian Journal of Civil Engineering and Planning, 8(1), 45 59.
Mustamin, M. R., Maricar, F., Lopa, R. T., & Karamma, R. (2024). Integration of UH SUH, HEC RAS, and GIS in Flood Mitigation with Flood Forecasting and Early Warning System for Gilireng Watershed, Indonesia. Earth, 5(3), 274–292.
Immanuella, L. A., Dermawan, V., & Winarta, B. (2022). Studi alternatif pengendalian banjir Sungai Welang dengan pendekatan pemodelan banjir aliran 2D. Jurnal Teknik Pengairan, 13(2), 245–257.
Pandey, M., et al. (2021). Modeling of Coastal Inundation in Response to a Tropical Cyclone Using a Coupled Hydraulic HEC RAS and ADCIRC Model. Journal of Geophysical Research: Oceans.
Paimin, S., & Purwanto, A. (2010). Sidik Cepat Degradasi Sub Daerah Aliran Sungai (Sub Das).
Parsa, A. S., et al. (2016). Floodplain Zoning Simulation by Using HEC RAS and CCHE2D Models in the Sungai Maka River. Applied Water Science, 26, 36089.
Pramadani, F. M., & Aprizal, A. (2023). Analisa luas genangan menggunakan aplikasi HEC RAS 6.1 secara 3D pada DAS Way Pisang. Jurnal Teknik Sipil, 14(2), 3477.
Peker, İ. B., Gülbaz, S., Demir, V., Orhan, O., & Beden, N. (2024). Integration of HEC-RAS and HEC-HMS with GIS in flood modeling and flood hazard mapping. Sustainability, 16(3), 1226.
Renaningsih, S. (2018). Integrated simulation of spillway and diversion structure in flood risk assessment of Upper Solo River. Journal of the Civil Engineering Forum, 4(2), 117–128.
Salsabila, S., Dermawan, V., & Cahya, E. N. (2025). Studi efektivitas pembangunan kolam retensi pada Sungai Bremi untuk mengatasi banjir menggunakan HEC RAS 6.5. Jurnal Teknologi dan Rekayasa Sumber Daya Air, 5(1), 011.
Sangari, J. R. R. (2014). Ekopreferensi dua jenis Avicennia terhadap parameter lingkungan di tegakan bakau muara Sungai Wulan Demak. Jurnal Ilmiah Platax, 2(3), 45–58.
Saputra, A. S., Sisinggih, D., & Prasetyorini, L. (2023). Pemodelan pengendalian banjir di Kali Hardisingat Kabupaten Kediri menggunakan HEC RAS 6.2 [Tesis sarjana]. Universitas Brawijaya.
Saputra, Z. A. E. (2025). Manajemen pengendalian banjir untuk mitigasi bencana di Kabupaten Demak (Studi Kasus: Sungai Wulan) [Tesis Magister]. Universitas Islam Sultan Agung Semarang.
Soentoro, E. A., et al. (2019). Kajian rehabilitasi tanggul kritis Sungai Wulan di Kabupaten Kudus sebagai upaya mitigasi bencana banjir [Tesis S2]. UGM.
Schumann, G., Baldassarre, G. Di., (2009). The utility of spaceborne radar to render flood inundation maps based on multialgorithm ensembles.
DOI: http://dx.doi.org/10.30659/jkr.v5i2.46077
Refbacks
- There are currently no refbacks.