Conceptual model of geotechnical information system

Geological, geodynamical and hydrological research in Zagreb area resulted in several spatial data of different lineage, coordinate systems and resolution. The goal of this paper is the gathering of data in a unique geotechnical information system, which will br the basis for further analysis. We are using ArcGIS modules for spatial and geostatistical analysis. Geotechnical information systems can be used to prevent, mitigate and alleviate damage caused by the natural disasters such as eartquakes and landslides. However, the geotechnical data bases have not been utilized extensively. Examples of using the data bases this chapter for seismic hazards assessment, planning for new structures, ground water hydrology, disaster mitigation systems of gas pipelines, and infrastructure management systems are presented

Precise geodetic and hydrographic measurements in Karst areas

Recent advances in GPS-technology (GNSS) enable hydrographic surveyors to capture the topography of the bottom and the water surface with even more accuracy. Faculty of Geodesy, University of Zagreb, recently acquired the latest technology for performing the precise hydrographic surveying: Trimble R8 GNSS receiver that is going to be used with already used echo sounding equipment. The GSM signals are used for transmitting corrections from the base station to the rover. Thus, it is possible to use single-frequency DESO 14 for two-frequencies bathymetry through repeating the course of the vessel on exactly the same points with both transducers. It is expected that the new technology shall yield more accurate results and increase measurement speed, because the OTF times should be significantly shortened

Geodesy, tectonics and geodynamics of Dinnarides

This paper summarises recent aetivities on merging the geodetic, geologic and neotectonic evidence of geodynamics in Croatian part of Dinnarides. The area of the City of Zagreb, which is the boundary zone of Eastern Alps, Dinnarides and Pannonian Basin is incIuded as well. It is shown here that the evidence for fractures of Eastern Adriatic differs from the previous hypotheses. This concIusion is derived from the results of various geodetic measurements: satellite positioning (GPS), astro-geodetic measurements of detlections of the vertical. These results are combined with geologic measurements and results of seismic activity studies in order to give more detailed and more accurate picture of the current situation in the tectonically very active region of Dinnarides. Several GPS-campaigns performed in the City of Zagreb area are examined as well. Due to the proximity of Croatian capitol, special attention has been paid to the effects of possible hazard on construction code

Application of 3D terrestrial laser scanning in geodynamic monitoring

During last 10 years, geodesists from the Faculty of Geodesy, University of Zagreb, together with geologists and tectonicians established and performed a number of series of GPS-measurements on the Geodynamic Network of the City of Zagreb. The results of these campaigns emphasized the spots with higher level of geodynamic activity, resulting in damages on objects: houses, walls, churches. Therefore, the technology of threedimensional laser scanning has been employed in order to capture much more detailed picture of fast movements. In the first experimental phase of the project, only rapidly sliding areas are observed. The main hypothesis of proposed research is to check if the technology of precise laser scanning is able to produce comparable point clouds showing the movements of objects in the field. As an additional source of information, this research should contribute to the better understanding of the processes below the Earth surface

Geology, tectonics, geodesy and geodynamics of Croatia

This paper summarizes recent research activities on merging the geodetic, geologic and neotectonic evidence of geodynamics in Croatia. The area of the City of Zagreb, which is the boundary zone of Eastern Alps, Dinnarides and Pannonian Basin is included as well. It is shown here that the evidence for fractures of Eastern Adriatic differs from the previous hypotheses. This conclusion is derived from the results of various geodetic measurements: satellite positioning (GPS), astro-geodetic measurements of deflections of the vertical. These results are combined with geologic measurements and results of seismic activity studies in order to give more detailed and more accurate picture of the current situation in the tectonically very active region of Dinnarides. Several GPS-campaigns performed in the City of Zagreb area are examined as well. Due to the proximity of Croatian capitol, special attention has been paid to the effects of possible hazard on construction code

Five years of EUREF-permanent GPS-stations in Croatia

In October 2000, the Faculty of Geodesy, University of Zagreb, with the support o German Federal Agency for Cartography and Geodesy (BKG) and Croatian State Geodetic Administration, established two permanent GPS-stations: one in Dubrovnik and another one in Osijek. The stations became the part of large global network International GPS Service for Geodynamics (IGS), ie. the part of EUREF/Permanent project. This paper describes the background for the choice of locations, stabilization and precise measurements of local GPS-networks that connected the stations with EUREF/CROREF points nearby. The problems in the maintenance of the stations have been described as welI. A view on the perspective of permanent GPS-services in Croatia is given, too

Two-frequencies bathymetry of Plitvice Lakes

Faculty of Geodesy, University of Zagreb, recently acquired the latest technology for performing the precise hydrographic surveying. The equipment consists of ATLAS DESO 14 surveying echosounder with two transducers: one with high frequency (210 kHz) and second with low frequency (33 kHz). The position of the transducer is determined with Real Time Kinematics GPS pair of Trimble R8 receivers. Thus, it is possible to use single-frequency DESO 14 for two-frequencies bathymetry through repeating the course of the vessel on exactly the same points with both transducers. The results of the application of this method in measuring two lakes in the National Park Plitvice Lakes are shown in this paper

Correlation between geodetic and geological models in the geodynamic network of the city of Zagreb

Since 1997 till 2008, several series of precise GPS measurements have been conducted on specially stabilized points of Geodynamical Network of City of Zagreb with purpose of investigation of tectonic movements and related seismic activity of the wider area of the City of Zagreb. From this series of GPS measurements geodetic model of tectonic movements has been created. In the area of interest, independent geological investigations have been conducted through even longer period of time which resulted in geological model of tectonic movements. Comparison and correlation of these two independent models will be presented in this paper