Spatial Analysis of Flood Inundation From Sentinel-1 Imagery Using Google Earth Engine (Case Study: Bengawan Jero Lamongan Regency)
Keywords:
Change Detection, Flood Inundation, Google Earth Engine, Lamongan Regency, ThresholdAbstract
Flooding is a natural disaster due to rivers that are no longer able to accommodate excessive rainwater so that water overflows and inundates the surrounding area. During the rainy season, many areas in Indonesia experience flooding, one of which is the Lamongan Regency. In early 2022, seasonal flooding occurred due to runoff from Bengawan Jero which caused many houses, agricultural land and access roads to be submerged in water. To improve disaster mitigation activities, it is necessary to identify flooding areas using remote sensing. The distribution area of flood inundation was identified using change detection and threshold methods. The change detection method is carried out by using ratio images from Sentinel-1 image data. The results of land cover in Lamongan Regency resulted in 9 land cover classes. Where is dominated by agricultural class land cover with an area of 1057.94 km2 with a percentage of the total area of Lamongan Regency is 60.53%. While the smallest land cover area is the mangrove class covering an area of 101.237 km2 with a percentage of the total area of 0.058%. Extraction of the inundation area was carried out with two different threshold values obtained from equations and statistical calculations. The flood inundation area generated on January 31, 2022, for the first threshold value is 54.932 km2 with an overall accuracy of 97% with a kappa coefficient is 0.94. While the flood inundation area with the second threshold value is 90.330 km2 with an overall accuracy of 94% and a kappa coefficient is 0.88.
References
Alawiyah, A. M., & Harintaka, H. (2021). Identifikasi Genangan Banjir di Wilayah DKI Jakarta Menggunakan Citra Satelit Sentinel-1. JGISE: Journal of Geospatial Information Science and Engineering, 4(2), 95–101.
BNPB. (2010). Rencana Strategis Badan Nasional Penanggulangan Bencana Tahun 2010 – 2014. BNPB.
BPS. (2021). KABUPATEN LAMONGAN DALAM ANGKA 2021. BPS Kabupaten Lamongan.
Congalton, R. G., & Green, K. (2019). Assessing the accuracy of remotely sensed data: principles and practices. CRC press.
ESA. (2012). Sentinel-1: ESA’s Radar Observatory Mission for GMES Operational Services (K. Fletcher, Ed.). ESA Communications.
Fajrin, F., yasma Adha, M., & Armi, I. (2019). Pemanfaatan Citra Sentinel-1 Sar Untuk Deteksi Banjir Studi Kasus Pangkalan Koto Baru Sumatera Barat. Seminar Nasional: Strategi Pengembangan Infrastruktur (SPI) 2019.
Guo, Y., & Manatunga, A. K. (2009). Measuring agreement of multivariate discrete survival times using a modified weighted kappa coefficient. Biometrics, 65(1), 125–134.
Heryana, A. (2020). Pengertian dan Jenis-Jenis Bencana. Jakarta: Universitas Esa Unggul.
Kasanah, N. (2020). Analisis lahan sawah tergenang banjir menggunakan metode change detection dan Pppm (phenology and pixel based paddy rice mapping)(studi kasus: Kabupaten Demak). Jurnal Geodesi Undip, 10(1), 259–268.
Lehner, B., Verdin, K., & Jarvis, A. (2008). New global hydrography derived from spaceborne elevation data. Eos, Transactions American Geophysical Union, 89(10), 93–94.
Lillesand, T., Kiefer, R. W., & Chipman, J. (2015). Remote sensing and image interpretation. John Wiley & Sons.
Moothedan, A. J., Dhote, P. R., Thakur, P. K., Garg, V., Aggarwal, S. P., & Mohapatra, M. (2020). Automatic flood mapping using sentinel-1 GRD SAR images and Google Earth Engine: a case study OF DARBHANGAH, BIHAR. Recent Advances in Geospatial Technology & Applications, IIRS Dehradun, India, 1–4.
Ngurawan, M. G. R. (2021). Analisis Sebaran Spasial Genangan Banjir Dengan Data Sentinel-1 Menggunakan Google Earth Engine (Studi Kasus: Kalimantan Selatan). Institut Teknologi Sepuluh Nopember.
Pekel, J.-F., Cottam, A., Gorelick, N., & Belward, A. S. (2016). High-resolution mapping of global surface water and its long-term changes. Nature, 540(7633), 418–422.
Pramana, C. J. (2014). Implementasi metode thresholding dan metode regionprops untuk mendeteksi marka jalan secara live video. Jurnal Universitas Dian Nuswantoro Semarang, 1(1), 1–9.
Saputro, A. D. (2021). Perancangan Wisata Edukasi Botanical Science Center Kabupaten Lamongan. Universitas 17 Agustus 1945.
Utomo, P. P. (2020). Identifikasi Sebaran Banjir Menggunakan Citra Satelit Sentinel-1. Jurnal Online Mahasiswa (JOM) Bidang Teknik Geodesi, 1(1).
Vanama, V. S. K., Rao, Y. S., & Bhatt, C. M. (2021). Change detection based flood mapping using multi-temporal Earth Observation satellite images: 2018 flood event of Kerala, India. European Journal of Remote Sensing, 54(1), 42–58.
Zanaga, D., Van De Kerchove, R., Daems, D., De Keersmaecker, W., Brockmann, C., Kirches, G., Wevers, J., Cartus, O., Santoro, M., & Fritz, S. (2022). ESA WorldCover 10 m 2021 v200.
