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Mircea Radulian, National Institute for Earth Physics (Romania)
Bogdan Grecu, National Institute for Earth Physics (Romania)
Neculai Mandrescu, National Institute for Earth Physics (Romania)
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Romanian territory is highly affected by the earthquakes generated in the Vrancea region. Two-three destructive earthquakes (M > 7) each century are generated in Vrancea at intermediate depths. These shocks are particularly felt over huge areas from Scandinavia and north Russia to Greek islands. Several dense-populated areas are strongly affected by the seismic radiation from Vrancea large events, especially in Romania, Bulgaria, Republic of Moldova and Ukraine. Although the earthquake effects are mostly contributing to the geohazard in Romania, other factors, like landslides, liquefactions, densifications, collapses and rock falls are also important and have to be considered.
Our main goal is to analyze the present day geodynamical processes and integrate them in a geohazard map over Romanian territory. A procedure to quantify, weigh, and aggregate into one single map data regarding effects of earthquakes and those regarding present day geodynamical processes is proposed and applied.
The necessary steps to evaluate these factors consist of (1) identifying and delineating the territory to be studied, (2) defining the basic unit for calculating the severity of geological hazards, (3) quantifying relative weight of each factor. The weight is based on three considerations: severity of consequences (loss of life, injuries, property damage), frequency of occurrence of the event, and difficulty of prevention or mitigation of its effects. The largest weights are assigned to earthquakes, as they have the largest damaging potential.
The next, lower weight is taken by landslides affecting large areas of the Romanian territory, followed by liquefactions and densifications. The procedure adopted for mapping geohazard factors is standardized and homogenized for the whole territory considered.
Finally, a high quality and homogenized map is produced, constituting a complete tool for both scientists and emergency managers, giving simultaneous access to related geohazard and land-use data. The entire information available together with the related potential features resulted from our analysis are integrated in a GIS database, providing decision makers with timely, reliable and cost-effective information, in order to increase the capacity to be resilient in the face of geohazards. We discuss also policy recommendations on joint efforts and emergency management measures to be considered and implemented by government.
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