In the wake of the devastating floods that struck Lower Saxony over the 2023/2024 New Year period, agricultural businesses faced significant challenges. The Lower Saxony Ministry of Food, Agriculture, and Consumer Protection swiftly initiated a flood subsidy program to support affected farmers. However, assessing the extent and duration of flooding across approximately 10,000 parcels manually was impractical. Enter EFTAS Remote Sensing Transfer of Technology, a company based in Münster, Germany, which stepped in to revolutionize the process using cutting-edge technology.
Led by C.-H. Yang, EFTAS leveraged Synthetic Aperture Radar (SAR) data, primarily from the European Space Agency’s Sentinel-1 satellites, to develop a semi-automated system for detecting and quantifying flood coverage. This innovative approach not only streamlined the assessment process but also provided a reliable method for future disaster management.
“The traditional manual assessment methods were time-consuming and prone to human error,” explained Yang. “By utilizing SAR data, we were able to create a more efficient and accurate system that can be adapted for various applications, from post-event evaluation to near real-time emergency response.”
The project covered an expansive area of 47,618 km², utilizing 45 Sentinel-1 image packages with observations every 3–5 days. The team enhanced image quality through adaptive non-local filtering and developed a GIS-based decision tree to refine results by excluding permanent water bodies. This meticulous process ensured that the flood extents were precisely mapped, even capturing dynamic changes near Lake Dümmer.
The integration of additional datasets, such as Sentinel-2 imagery and local photos, validated the flood evaluations, demonstrating the robustness of the SAR-based approach. “Our operational workflow showcases the adaptability of SAR for diverse applications,” Yang noted. “This technology is not just about assessing past events; it’s about being prepared for future ones.”
The implications for the energy sector are significant. Accurate flood mapping can aid in assessing risks to energy infrastructure, such as power plants and transmission lines, which are often located near water bodies. By integrating SAR data into their risk management strategies, energy companies can better prepare for and mitigate the impacts of flooding.
Looking ahead, EFTAS plans to incorporate high-resolution imagery for urban assessments and leverage rapid-revisit SAR constellations like Capella and ICEYE. These advancements will further enhance the precision and timeliness of flood detection, benefiting not only the agricultural sector but also urban planning and disaster response.
The research was published in ‘The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences,’ known in English as the International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences. This publication underscores the scientific rigor and potential impact of the study.
As the world grapples with increasing climate-related disasters, the work of Yang and the EFTAS team offers a beacon of hope. Their innovative use of SAR technology not only aids in subsidy allocation but also paves the way for broader applications in disaster management, ultimately contributing to a more resilient future.