In the early months of 2024, the Demak Regency in Indonesia underwent a significant flood, causing severe damage to the local community. It was first recorded on February 3rd, 2024, as the embankments were damaged due to flood and high precipitation. At least six embankments have been broken and breached, allowing floodwaters to pass through and inundate roughly eight areas (Karangtengah, Mijeh, Demak, Karanganyar, Sayung, Wonosalam, and Gajah Sub-districts and Kudus Regency).
Figure 1. Average daily precipitation surrounding the Demak Regency
Figure 2. Land subsidence surrounding the Demak Regency
Figure 3. Land Use and Land Cover (LULC) in 2018 (left) and 2022 (right) surrounding the Demak Regency
Figure 4. Inundated agricultural land and built area (2022) surrounding the Demak Regency
The flooded areas were derived from a Sentinel-1 SAR (Synthetic Aperture Radar) assessment by comparing January to February backscatter against February to March 22nd. The scale of the disaster is staggering, with around 10,000 hectares of area in the surrounding Demak Regency being inundated. The Land Use and Land Cover (LULC) analysis revealed that ~3,000 ha of agricultural land in Demak Regency and ~2,000 ha of built-up areas in Grobogan Regency have been inundated by flood. Although used by many flood assessments, the analyses within this article were derived entirely from secondary data without any means of validation due to a lack of primary data. Hence, this analysis serves as a quick assessment of the 2024 Demak Flood.
Heavy precipitation was associated with the disaster. BMKG (Badan Meteorologi, Klimatologi, dan Geofisika/Meteorology, Climatology, and Geophysical Agency) recorded that during the first week of February 2024, the rain intensities fell in the ‘Moderate’ (20-50 mm/day) to ‘High’ (50-100 mm/day) class. Moreover, a research study has discovered that Demak is subjected to land subsidence, with 6-65 cm/year rates. The LULC data retrieved from 2018 and 2022 reveals the diminishing extent of green areas and the increase of built environments over the years.
Figure 5. Population Density (2020) surrounding the Demak Regency
Local authorities’ rapid assessment on February 18th revealed that 18,739 people were temporarily displaced across 125 shelters. Karanganyar Sub-district had the highest displacement, with 5,837 individuals. An update on March 23rd reported a second wave of flooding, affecting 16,466 people. Once again, Karanganyar Sub-district was hardest hit, with 11,767 affected.
Historical data on Demak community displacement reveals that Semarang City and other villages away from the coastline are the preferred migration destinations. Semarang City attracts those seeking better services and job opportunities, while nearby villages are chosen by those with limited resources for distant migration. Demak’s Data and Information Agency reports that most communities were compelled to relocate to the nearest villages, where public facilities like schools, mosques, and local sports centres are available. However, this movement to the closest location highlights their unpreparedness—despite the clear vulnerability and exposure of the area to hazards, supplies and logistics were inadequately prepared.
The Demak community, especially those residing near the coastline, faces significant vulnerability to disasters and climate change risks, including floods. Before the occurrence of floods, these residents grapple with climate change impacts (e.g., rising sea levels), which annually damage their settlements and livelihoods. With limited adaptive capacity to confront these ongoing threats, the community is concerned about recovery post-flood. Consequently, the rehabilitation of their well-being and the reconstruction of vital infrastructure necessitate external assistance from entities like local and national governments and non-governmental organisations (NGOs).
References:
- Funk, C., Peterson, P., Landsfeld, M., Pedreros, D., Verdin, J., Shukla, S., Husak, G., Rowland, J., Harrison, L., Hoell, A., & Michaelsen, J. (2015). The climate hazards infrared precipitation with stations—A new environmental record for monitoring extremes. Scientific Data, 2(1), 150066. https://doi.org/10.1038/sdata.2015.66
- Hasan, M. F., Smith, R., Vajedian, S., Pommerenke, R., & Majumdar, S. (2023). Global land subsidence mapping reveals widespread loss of aquifer storage capacity. Nature Communications, 14(1), 6180. https://doi.org/10.1038/s41467-023-41933-z
- Impact Observatory, Microsoft, and Esri. (2022). ESRI 10m Annual Land Use Land Cover (2017-2022). [Accessed from: https://gee-community-catalog.org/projects/S2TSLULC/]
- Ibid.
- Pusat Data Informasi dan Komunikasi Kebencanaan BMKG. (2024). Bulletin Info Bencana: 5(2).
- Azeriansyah, R. et al. (2019). Land Subsidence Monitoring in Semarang and Demak Coastal Areas 2016-2017 Using Persistent Scatterer Interferometric Synthetic Aperture Radar. IOP Conference Series: Earth and Environmental Science 313:012040
- worldpop.com. (2013). Open Spatial Demographic Data and Research. [Accessed from: https://developers.google.com/earth-engine/datasets/catalog/WorldPop_GP_100m_pop#citations]
- BNPB, I. (2024). [UPDATE] Banjir Demak: BNPB Melakukan Pendampingan Dalam Pemenuhan Kebutuhan Dasar Pengungsi. BNPB. Retrieved March 25, 2024. [Accessed from: https://bnpb.go.id/berita/update-banjir-demak-bnpb-melakukan-pendampingan-dalam-pemenuhan-kebutuhan-dasar-pengungsi]
- BNPB, I. (2024). [UPDATE]: Penanganan Banjir Demak dan Kudus, Pemenuhan Kebutuhan Pengungsi di Optimalkan. BNPB. Retrieved March 25, 2024. [Accessed from: https://www.bnpb.go.id/berita/update-penanganan-banjir-demak-dan-kudus-pemenuhan-kebutuhan-pengungsi-di-optimalkan]
Written by
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Abimanyu Arya Atmaja (DCR Research Officer)
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Kharis Aulia (DCR Research Officer)
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Dekka Dhirgantara (SSC Research Officer)
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Muhammad Asa (SSC Research Officer)
Edited by
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Chelsea Patricia (Academic Officer)
