Landslide and Soil Erosion Inventory Mapping Based on High-Resolution Remote Sensing Data: A Case Study from Istria (Croatia)

Abstract

The central part of the Istrian Peninsula (Croatia) is the area of the Eocene flysch basin, i.e. “Gray Istria, which is prone to weathering and active geomorphological processes. The high erodibility of the Istrian marls led to the formation of steep barren slopes and badlands exceptionally susceptible to slope movements. This research presents the application of high-resolution remote sensing data, i.e., Light Detection and Ranging (LiDAR) data and orthophoto images, for landform mapping at a large scale (1:500). Visual interpretation of remote sensing data was done for the pilot area (20 km2) near City of Buzet to produce detailed inventory maps for implementation in the spatial planning system. There is a lack of detailed inventory maps because systematic mapping was not performed for any part of Istria until the scientific research project LandSlidePlan (HRZZ IP-2019-04-9900), funded by the Croatian Science Foundation. After preliminary visual interpretation of LiDAR DTM and field verifications, it was concluded that four types of landforms could be mapped, i.e. badlands, gully and combined erosion, unstable slopes and landslides. The research objective is to show the representative examples and potential of direct and unambiguous identification and mapping of small and shallow landslides and soil erosion processes based on the visual interpretation of high-resolution remote sensing data in flysch-type rock.