Use of a LiDAR-derived landslide inventory map in assessing Influencing factors for landslide susceptibility of geological units in the Petrinja area (Croatia)

Tihomir Frangen,Mirja Pavić,Vlatko Gulam,Tomislav Kurečić

doi:10.4154/gc.2022.10

Abstract

A landslide inventory was created for an area of 22.6 km2 near Petrinja city in northern Croatia, based on the high-resolution LiDAR data complemented by orthophoto maps. A total of 216 landslides were identified, covering 2.91 % of that area. Landslide polygons were overlain on geological units based on the Basic map of SFRY at a scale of 1:100,000 that is the largest scale geological map available for the whole of Croatia. The relationship between landslides and geological units was expressed as a landslide index. Three geological units displayed increased landslide susceptibility. A Pliocene unit clearly had the largest susceptibility, followed by a Palaeocene-Eocene unit, and finally a Badenian unit. Landslide density was analyzed within these geological units to identify influencing factors for landslide initiation. Each geological unit revealed different influencing factors. The Pliocene unit is mostly influenced by bedding plane orientation and local relief. Heterogeneousness lithology is the dominant factor in the Paleocene-Eocene unit, while the Badenian unit demonstrated the least certain interpretation as there are multiple factors involved. The forest road is presumed to be crucial, followed by spring occurrences and proximity to the tectonic boundary. The basic geological map of SFRY proved to be a viable source of geological information for the creation of landslide susceptibility maps at a scale of up to 1:100,000, but with limitations in the case of lithologically heterogeneous geological units. Larger scale maps require more detailed research as landslide susceptibility factors vary in each geological unit.

Highlights

Landslides are one of the natural hazards that has a major impact on human lives
A landslide inventory was created for an area of 22.6 km2 near Petrinja city in northern Croatia, based on the high-resolution LiDAR data complemented by orthophoto maps
Landslide polygons were overlain on geological units based on the Basic Geological Map of SFRY at a scale of 1:100.000 that is the largest scale geological map available for the whole of Croatia

Summary

Introduction

Landslides are one of the natural hazards that has a major impact on human lives They cause major economic losses, and direct loss of life, and are present worldwide. HAQUE et al (2016) presented a spatiotemporal distribution of deadly landslides in 27 European countries over 20 years (1995–2014) with a total of 1370 deaths and an average economic loss of approximately 4.7 billion Euros per year. All these studies are based on reports from major landslides, and all agree that the numbers are certainly underestimated as the majority of landslides are unreported. When summarized and collated, the costs of those smaller events are higher than the combined major, 100-year events

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