engleski

First Experience with Ground Based LiDAR in Omiš and Duće Areas

Dalmatia region has dozens of registered active landslides and rockfall zones. For this study Omiš and Duće areas are selected as very active and potentially dangerous zones for inhabitants, residential areas and community infrastructure. The cliffs over the town of Omiš are made of limestone, while the slopes over Duće are made of Eocene flysch formation. Although these areas are geologically very different they share one common issue - rockfalls. In periods after heavy rain and/or considerable low air temperature many sudden rockfalls in these areas are often recorded. Stabilizing and managing entire area without localising potential threats would require considerable funding, which private owners and local communities could not afford. One of the possible and more suitable methods for forecasting rockfalls in these areas could be the use of 3D scanning (LIDAR based technology). LIDAR (Light Detection and Ranging) is an optical remote sensing technology that can measure the distance to the target. In this case Optech ILRIS-3D with accuracy of less than 1 cm at 100 meters was used. With such an instrument it is possible to cover large areas and acquire coordinates in numerous points unlike any other geodetic method. By periodically observing and monitoring the proposed zones, it could be possible to determine unstable blocks or even slope movement. Comparison of two or more records could be an efficient way of detecting movement and deformation in the field. Except detecting unstable blocks, this temporal model of surveying can also be applied for observing erosion process in soft rock. Marl, as an example of soft rock, is very prone to weathering so erosion process in this material can be observed in a relatively short period. This article presents the authors’ first experience with this technology, methods of site selection, first field measurements, with retrospect to future guidelines and possible applications.

Flysch; Limestone; Rockfall; Erosion; LiDAR

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