At the urgent request of the Indonesian government institution (BRIN), the disaster-response team led by Professor Lixin Wu of Central South University, Academician of the International Eurasian Academy of Sciences, conducted rapid flood monitoring and assessment across Indonesia. The initial assessment covered November 26 to December 1, 2025 (https://gip.csu.edu.cn/info/1483/8234.htm), and the follow-up assessment from December 3 to 10, 2025 (https://gip.csu.edu.cn/info/1483/8236.htm), tracked the evolving flood situation. Referring to the previous assessments, the latest update for December 9 to 11, 2025 provides the most recent evaluation of flood conditions and impacts. All assessments utilized the Disaster Response System for the Belt and Road (DRS4BR) and its Knowledge-Driven Flood Intelligent Monitoring (KDFIM) module, enabling rapid flood detection and impact analysis.
This work incorporated multi-source satellite data, including GF-3, Sentinel-1/2, and Landsat-8/9, along with OpenStreetMap (OSM) building and road datasets and ESA WorldCover (ESA_WC). These datasets were used to comprehensively evaluate flood impacts on infrastructure, residential buildings, and agricultural land across Indonesia. Disaster maps were produced in response to BRIN’s request for emergency satellite-based support.
The updated assessment of December 9–11, 2025 shows that floodwaters have largely receded, with remaining water depths generally less than 1 meter. The length of affected roads has decreased to approximately 200 km (Fig. 1); flooded cropland has reduced to about 420 km² (Fig. 2); and the number of affected residential buildings has dropped to around 800 (Fig. 3). These results indicate substantial improvement in flood or inundation conditions across the whole country. Sub-regions labeled A through E now exhibit only localized residual flooding, with major road disruptions, cropland inundation, and residential impacts largely alleviated.
Fig. 1 Flood Impacts on Roads in Indonesia, Dec. 9-11, 2025
Fig. 2 Flood Impacts on Croplands in Indonesia, Dec. 9-11, 2025
Fig. 3 Flood Impacts on Buildings in Indonesia, Dec. 9-11, 2025
