MONITORING AND ASSESSMENT OF STORM DAMAGE TO FORESTS USING THE PHOTOGRAMMETRIC METHOD

Abstract

The escalating intensity of climate change-induced storms necessitates efficient methods for surveying storm-damaged forests. This study conducted in Estonia employed Unmanned Aerial Vehicles (UAVs), equipped with compact cameras, to assess damage over a 16 square kilometer storm-affected area. We created digital surface models (DSMs) and orthophoto mosaics using two types of drones - a fixedwing and a multirotor. While both types had their distinct advantages depending on the terrain, a 70% x 70% overlap of images was found to be inadequate for proper alignment of images in heavily forested areas. Comparing drone-generated DSMs with existing DSM data was a quick method for locating storm-damaged areas, although not ideal for accurately calculating their extent. It was also found that orthophoto mosaics with a 0.2 m resolution were sufficient for damage analysis.