engleski

Two years observation results of the Grohovo Landslide using integrated remote monitoring

The advanced comprehensive monitoring system was designed and applied to the Grohovo Landslide in the Rječina River Valley, Croatia, in the frame of the Croatian Japanese bilateral scientific project on ‘Risk Identification and Land-Use Planning for Disaster Mitigation of Landslides and Floods in Croatia’. The monitoring equipment was selected based on landslide characteristics, equipment possibilities related to field conditions, so as scientific requirements. The focus of the monitoring system establishment was on effective combination of sensors (equipment fusion) Necessary improvements of existing monitoring system have been analyzed and presented on the basis of 1.5 year period of measurement. The use of multiple sensors at the same measuring point should guarantee the possibility to check redundancy and correlation of measurements. Equipment fusion is also useful in prevention of losing data if one instrument fails. Usage of geodetical and geotechnical equipment fusion in combination with hydrological monitoring equipment, enables reconstruction of the relationships between rainfalls, groundwater levels and landslide response. The results of monitoring system should provide basis for development and validation of numerical models and adequate early warning system inside the landslide hazard management framework. In order to provide establishment of the reliable early warning system alarm thresholds should be based on existing cognition of the Grohovo landslide behavior, which depends greatly on the reliability of the gathered monitoring data. In this paper, an overview of the two years observations results of the Grohovo Landslide using an integrated remote monitoring system as well as brief overview of the latest upgrades in the installed system will be presented. Since the monitoring system on the Grohovo landslide integrates two different types of monitoring, data will be presented accordingly. The latest data from the overall geotechnical monitoring system, was collected in the early September 2013, during the system upgrade and maintenance works. Regarding the geotechnical part of the monitoring system, data presented in this paper includes records from long span extensometers, short span extensometers, vertical extensometers and inclinometers. Second part of the data presented in this paper refers to geodetic monitoring. This part of the Grohovo Landslide monitoring system includes geodetic surveys of 25 benchmarks (prisms) observed by robotic total station and measurements from 9 GPS receivers (rovers) connected in local GPS network. Analyses of equipment in fusion behavior will be presented trough the analyses of results of different monitoring sensors installed at the same points, which in case of this paper refers to poles containing both geodetic prisms and GPS rovers. Data reviews will include standard components used to describe chain of events recorded by installed sensor.

landslide; integrated monitoring system; geodetic monitoring; geotechnical monitoring

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