Thematic Mapping for Disaster Risk Assessment in Case of Earthquake

According to recent decades statistics the earthquakes cause major damages and casualties among all natural disasters, followed by floods and tropical cyclones. The annual risk for victims of earthquakes all over the World is estimated at 10 000 - 15 000 people per year. Several damaging earthquakes that shake Bulgarian territory (1818, 1858, 1904, 1928, 1977, 1986, 2012) led to significant damage. About 360 victims due to earthquakes are reported in Bulgaria since 1901 until now. To reduce human losses and damages it is necessary to have at disposal preliminary estimates of frequency and magnitude of the earthquakes, particular engineering characteristics of the seismic action and relevant opportunities for disaster management.

Earthquake risk estimation and management encompasses large quantity of heterogeneous information data sets, including different types of maps, statistical information and expert knowledge. This paper represents some of the efforts, performed within the framework of the university UACEG-CNIP research project dealing with a conceptual model for information system for expert express evaluation of the earthquake risk over the Bulgarian territory using GIS. It examines some problems that arise in thematic mapping for disaster management in case of earthquake due to the various types, structure and classification of data provided by various organizations. Main stages for data harmonization including georeferencing the information into a geographical reference system, standardizing the object classification, standardizing the level of detail, unifying the cartographic visualization are discussed and some advantages of the use of thematic maps for disaster management in case of earthquake are presented. The resulted maps aim to contribute to holistic seismic risk estimation for the territory of Bulgaria. These maps, logically coupled with the all information data set that has been collected and systematized within the framework of this project, would provide useful information for decision makers and stake holders, dealing with earthquake risk mitigation.