Vedran Jagodnik

A Landslide Monitoring and Early Warning System Using Integration of GPS, TPS and Conventional Geotechnical Monitoring Methods

An advanced comprehensive monitoring system was designed and used on the Grohovo Landslide in Croatia. Equipment selection was based on scientific requirements and consideration of possible ranges of monitored values and sensors precision. Establishment of an early warning system and defining of alarm thresholds is based on existing knowledge of the landslide behavior as well as collected comprehensive monitoring data. The focus of the early warning system establishment at Grohovo Landslide was on an effective combination of sensors (equipment fusion) with respect to detecting device malfunctions and reducing false alarms in the future. The weakest component in the Grohovo Landslide monitoring system is power supply based on solar devices, field data collecting and the data transmitting from the field PC to the control room at the University of Rijeka. This paper presents the main ideas and advances of the monitoring equipment fusion as well as weaknesses of the applied monitoring system at the Grohovo Landslide.

TXT-tool 2.385-1.2: Landslide Comprehensive Monitoring System: The Grohovo Landslide Case Study, Croatia

The Grohovo Landslide is located on the north-eastern slope of the Rjecina Valley, Croatia and it was reactivated in 1996 at the location of the landslide from 19th century. In 2009 the Croatian-Japanese joint research project “Risk identification and Land-Use Planning for Disaster Mitigation of Landslides and Floods in Croatia” was initiated and the Grohovo Landslide was chosen as a pilot area for monitoring system development. A comprehensive monitoring system was designed and installed. Integrated monitoring system consists of survey using GPS and robotic total station so as geotechnical monitoring using long span and sort span wire extensometers, inclinometers, pore pressure gauges and rain gauges. All measurements will be integrated in GIS for landslide risk management and early warning system. The monitoring results should provide a basis for develop and validate confidential numerical models and adequate hazard management.

Landslide Risk Reduction in Croatia: Scientific research in the framework of the WCoE 2014- 2017, IPL 173, IPL 184, ICL ABN

In this paper scientific activities of the Croatian Landslide Group (CLG), World Centre of Excellence on Landslide Risk Reduction (WCoE) of the International Consortium on Landslide (ICL) for the period 2014–2017, are shortly described. The results of scientific research are presented through the fields of landslide science: landslide identification and mapping, landslide investigation and testing, landslide monitoring, landslide modelling and landslide stabilization and remediation. It is concluded that the resulting landslide inventory maps, regional empirical rainfall intensity-duration thresholds, kinematic landslide models and soil strength parameters, landslide movement prediction models, numerical models and simulations and behavior of geotechnical construction for landslide stabilization provide necessary information for landslide risk management in Croatia. Besides applied scientific research, the general objectives of ICL WCoE are achieved in the framework of two Croatian IPL Projects and regional ICL Adriatic-Balkan Network.

Diversity of Materials in Landslide Bodies in the Vinodol Valley, Croatia

Numerous landslides of different types present common hazardous phenomena in the Vinodol Valley (64.57 km2), situated near the City of Rijeka in coastal part of Croatia. During the previous and present geological investigations in the Vinodol Valley almost all landslide types were identified: falls, topples, slides and flows. The Vinodol Valley is characterized by irregular shape and a range of different landforms due to complex geological and geomorphological conditions. The inside of the valley is built of Paleogene siliciclastic (flysch) deposits, which is surrounded by the relatively steep carbonate borders composed of Upper and Cretaceous limestone. Along the most part of the NE border vertical rocky cliffs occur. The lower parts and the bottom of the valley (i.e., flysch deposits) are covered by heterogeneous Quaternary superficial deposits. In the Vinodol Valley more than 200 active and dormant landslides in soils were identified. Most of the active landslides are covered by dense forest vegetation. Original landslide topographies of dormant landslides are significantly modified by the anthropogenic agricultural activities. For this reason, the appropriate landslide identification and mapping method is the visual interpretation of the high-resolution LiDAR-derived imagery. Identified landslides are generally shallow to moderate shallow, with slip surface depth of several meters, and small to moderate small, with volumes in a range of 103–105 m3. Due to the diversity of geological conditions in the Vinodol Valley and the large number of identified landslides, the index and classification properties of soils from the landslide-forming materials were investigated. Soil samples were taken and laboratory tested according to the rules of the European Soil Classification System. In this paper, results of preliminary investigations of the relationship between the different types of landslides and the landslide-forming materials are presented.