2D rain–discharge and inundation modeling for flood analysis in Buntung watershed, Sidoarjo regency
Abstract
Flooding is the most frequent natural disaster in Indonesia, accounting for 55.07% of national disasters. Sidoarjo Regency, particularly Waru District, is highly vulnerable to flooding caused by the overflow of the Buntung River. Flood inundation in the area may persist for up to two days with water depths reaching 30–40 cm. Rapid development of residential, industrial, and transportation areas within the Buntung Watershed has reduced infiltration capacity, while high rainfall intensity, tidal fluctuations, and downstream channel constriction further aggravate flooding conditions. Therefore, the development of a flood inundation model is essential to support effective flood mitigation planning.This study aims to analyze flood characteristics and inundation distribution for selected return periods. Hydrological analysis was conducted using annual maximum rainfall data from 2013–2024. Areal rainfall was determined using the Thiessen Polygon method and frequency distribution analysis. Rainfall–runoff modeling was performed using HEC-HMS to estimate flood discharge, while 2D inundation modeling was carried out using HEC-RAS 2D. Sensitivity analyses of mesh size, computation interval, and model parameters were performed prior to calibration to obtain an optimal and computationally efficient configuration.The results show that a 30 m mesh size and a 10-second computation interval provide the optimal simulation configuration. The Manning parameter has the greatest influence on inundation extent and flood depth. Model calibration produced NSE values of 0,724 respectively, indicating good model performance. The simulation results show that the 10-year return period flood inundation is predominantly characterized by water depths of <10 cm, accounting for 26.32% of the inundated area, followed by depths of 10–20 cm (22.58%), 20–30 cm (17.38%), 30–50 cm (22.27%), and >50 cm (11.45%). The inundation with depths greater than 50 cm is predominantly distributed in the downstream area of the Buntung River, which is influenced by tidal conditions.
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References
Affandy, N. A., & Anwar, N. (2019). PEMODELAN HUJAN-DEBIT MENGGUNAKAN MODEL HEC-HMS DI DAS SAMPEAN BARU. https://www.researchgate.net/publication/330824459
Baskoro, A. G., & Hertati, D. (2022). Implementasi kebijakan Penggunaan Dana Desa Tentang Penanganan Banjir di Desa Tropodo Kecamatan Waru Kabupaten Sidoarjo. Jurnal Noken: Ilmu-Ilmu Sosial, 7(2), 112–124. https://doi.org/https://doi.org/10.33506/jn.v7i2.1745
BNPB. (2018). Indeks Risiko Bencana Indonesia 2018. https://ppid.kemendagri.go.id/storage/dokumen/XrkTcqIfXIf4zwmWSjTZPvwdY37glvgJiKetkdc4.pdf
BNPB. (2025). Data Bencana Indonesia 2024. https://bnpb.go.id/
Brotowiryatmo, S. H. (2016). Review of Rainfall Hourly Distributionon the Island of Java. Dalam Journal of the Civil Engineering Forum (Vol. 2, Nomor 1).
Chu, X., & Steinman, A. (2009). Event and Continuous Hydrologic Modeling with HEC-HMS. Journal Of Irrigation And Drainage Engineering. https://doi.org/10.1061/ASCE0733-94372009135:1119
Darijani, Z., Ghaeini-Hessaroeyeh, M., & Fadaei-Kermani, E. (2025). Flood inundation and hazard mapping using the HEC-RAS 2D model: a case study of Adoori River, Iran. Modeling Earth Systems and Environment, 11(1). https://doi.org/10.1007/s40808-024-02280-0
Farooq, M., Shafique, M., & Khattak, M. S. (2019). Flood hazard assessment and mapping of River Swat using HEC-RAS 2D model and high-resolution 12-m TanDEM-X DEM (WorldDEM). Natural Hazards 2019 97:2, 97(2), 477–492. https://doi.org/10.1007/S11069-019-03638-9
Hamdi, M., El Molla, D. A., & Gad, M. A. (2019, Oktober). A comparison between 1D, 2D and semi 2D hydraulic models. https://www.researchgate.net/publication/350941223_A_comparison_between_1D_2D_and_semi_2D_hydraulic_models
Hidayah, E., Halik, G., Indarto, I., & Khaulan, D. W. (2023). Flood hazard mapping of the Welang river, Pasuruan, East Java, Indonesia. Journal of Applied Water Engineering and Research, 11(3), 333–344. https://doi.org/10.1080/23249676.2022.2114025
Kompas.com, 2024. (2024). Jalan Terendam Banjir Setelah 3 Jam Diguyur Hujan, Lalu Lintas Sidoarjo-Surabaya Lumpuh. https://surabaya.kompas.com/read/2024/12/24/193923678/jalan-terendam-banjir-setelah-3-jam-diguyur-hujan-lalu-lintas-sidoarjo
Miarso, B. T. (2014). Studi Kelayakan Proyek Pengendalian Banjir pada DAS Kali Buntung Kabupaten Sidoarjo Berdasarkan Analisis Biaya Manfaat dan Efisiensi Biaya. Desember, 7(2), 129–140.
Moriasi, D. N., Arnold, J. G., Liew, M. W. Van, Bingner, R. L., Harmel, R. D., & Veith, T. L. (2007). Model Evaluation Guidelines for Systematic Quantification of Accuracy in Watershed Simulations. Dalam Transactions of the ASABE (Vol. 50, Nomor 3).
Savitri, Y. R., Kakimoto, R., Anwar, N., Wardoyo, W., & Suryani, E. (2021). Reliability Of 2D Hydrodynamic Model On Flood Inundation Analysis. International Journal of GEOMATE, 21(83), 65–71. https://doi.org/10.21660/2021.83.j2073
Setiawan, B., Hasyim, A. W., & Sasongko, W. (2021). Skenario Penanggulangan Banjir Di Kabupaten Sidoarjo.
Tamiru, H., & Wagari, · Meseret. (2022). Machine-learning and HEC-RAS integrated models for flood inundation mapping in Baro River Basin, Ethiopia. 8, 2291–2303. https://doi.org/10.1007/s40808-021-01175-8
Triatmodjo, B. (2008). Hidrologi Terapan.
Upomo, T. C., & Kusumawardani, R. (2016). Pemilihan Distribusi Probabilitas Pada Analisa Hujan Dengan Metode Goodness of Fit Test. Jurnal Teknik Sipil dan Perencanaan, 18(2), 139–148. https://doi.org/10.15294/jtsp.v18i2.7480
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