Framework for early detection and characterisation of hydraulically induced shallow landslides

Shallow landslides triggered by intense and prolonged precipitation represent a major geohazard in many soil-dominated landscapes. This study presents the development of an integrated monitoring and modelling framework for the early detection and characterisation of hydraulically induced shallow landslides. The approach is based on the selection of three representative pilot sites and the implementation of comprehensive field investigations (engineering-geological, pedological, geotechnical, hydrological) and laboratory testing to determine the chemical, physical, and mechanical properties of characteristic soil horizons. A real-time monitoring system has been established to continuously record  soil volumetric water content and suction, together with precipitation, providing high-resolution hydro-meteorological and hydrological data. Geoelectrical measurements and field investigations were applied to characterise soil structure and depth, and to establish relationships between geophysical parameters and physico-mechanical soil properties. These analyses enable the development of a non-invasive monitoring approach capable of diagnosing landslide initiation, delineating landslide geometry, and estimating potentially unstable volumes. Based on the monitoring data obtained at pilot sites, hydro-meteorological thresholds and critical soil parameters controlling shallow landslide occurrence are derived for key soil types. Safety factors and probabilistic landslide occurrence models are developed to identify dominant triggering mechanisms. The results contribute to a national-scale framework for shallow landslide susceptibility mapping and provide a transferable methodology for operational landslide early-warning systems. This research is supported by the Slovenian Research and Innovation Agency through research projects: A holistic approach to Earth surface processes driven by extreme weather events (J7-60124) and Geospatial information technologies for a resilient and sustainable society (GC-0006).