In July 2022 a winter storm dropped 550 mm of precipitation on the Southern Alps of New Zealand. This initiated large snow avalanches and a mass movement cycle of debris flows, and erosion, which was the largest observed in decades. Our drone lidar surveys were used by leading research teams to assess the rain-on-snow hazard sequence, and insights for future extreme alpine precipitation events as these become increasingly more frequent in the alpine environment.
In the aftermath of powerful storm events, accurately assessing the extent of damage to infrastructure and the surrounding environment is vital for effective recovery and proactive preparation for future events. Traditionally, this task has heavily relied on ground surveys and manual inspections, both aerial and on-ground, resulting in delays, limited data, and incomplete coverage. However, recent advancements in drone-based LiDAR (Light Detection and Ranging) technology have revolutionized the process, enabling comprehensive and timely evaluations of storm-induced changes.
Drone LiDAR systems leverage state-of-the-art laser scanning technology to create highly detailed three-dimensional maps of terrain and structures. When deployed for post-storm change detection, these drones capture data swiftly and accurately, offering a holistic understanding of the damage caused. By emitting laser pulses that bounce off objects and return to the sensor, LiDAR enables the creation of precise representations of the environment. Comparing pre- and post-storm LiDAR data allows experts to precisely identify alterations such as fallen trees, shifted land masses, damaged buildings, and compromised infrastructure. This is especially the case now with the LINZ Elevation data | Toitū Te Whenua – Land Information New Zealand (linz.govt.nz) project ensuring we have significant areas of NZ covered in publically available LiDAR to compare with.
The use of drone-based LiDAR technology for post-storm change detection offers numerous benefits. Firstly, the aerial perspective provided by drones enables efficient coverage of large areas that would be challenging or time-consuming to survey manually. These drones can navigate swiftly through hazardous or inaccessible terrain, including areas affected by flooding, landslides, or other perilous conditions, providing valuable information without risking human lives. Additionally, the LiDAR technology’s ability to penetrate dense foliage allows for accurate detection and assessment of changes even in heavily forested regions.
The deployment of drone-based LiDAR technology for post-storm change detection marks a groundbreaking advancement in disaster management and environmental monitoring. By harnessing the aerial agility of drones and the high-resolution data capture capabilities of LiDAR, response teams can rapidly gather precise information on storm-induced alterations. Combined with traditional remote sensing data such as satellite and manned aircraft this technology empowers decision-makers to make informed choices, allocate resources effectively, and expedite the recovery process.
The successful application of drone-based LiDAR in assessing the impact of the unprecedented precipitation storm on avalanche-prone areas in the Southern Alps demonstrates the immense potential of this technology and its transformative impact on post-storm evaluations.