Türki̇ye seismic microzonation national database – phase 1

The first study conducted in Türkiye under the title of "microzonation", aimed at evaluating earthquake-related risks at the local scale, was carried out in 1968, and this study marked the starting point of microzonation approaches at the national level. Although numerous local studies have been conducted under the heading of microzonation since 1968, the data obtained from these studies are generally contained within theses and technical reports. The existence of these theses and reports is often unknown to legal entities and public institutions—such as civil engineers, geoscientists, urban and regional planners, and municipalities—that could benefit from their outputs. For this reason, parameters required in engineering practice—such as shear-wave velocities (Vs), predominant ground vibration periods, site amplification, expected peak ground accelerations, and the resulting design spectra—which are typically included in microzonation studies, are obtained from AFAD's national databases (TADAS) rather than from site-specific local studies. However, it is a well-known fact that during the devastating Southeastern Anatolia earthquakes that occurred in 2023, the ground motion values and corresponding design spectra derived from the AFAD–TADAS database were exceeded. Therefore, it is essential for engineers to be familiar with the site-specific microzonation studies that exist for the cities in which they work. In this thesis, the results of seismic microzonation studies conducted in Türkiye over the last 20 years and archived in the Council of Higher Education (YÖK) thesis database were compiled, and the data contained in these studies were presented in a digital database using ArcGIS Pro software. In the initial stage, more than 30 academic studies (master's and doctoral theses) were compiled. Through this approach, it is aimed to enable engineers, other relevant professional groups, and public institutions to rapidly obtain information on microzonation studies conducted in Türkiye and the data derived from them. The digitized maps can be examined within the database; however, for more detailed analyses, consulting the original sources from which the data were obtained is recommended. This digital microzonation database is intended to serve as a guide for ongoing scientific and public projects in Türkiye that focus on seismic hazard and risk analyses within the scope of microzonation studies. The prepared database is provided as a CD annexed to the thesis, and a video included on the same CD explains how to open and use the database in ArcGIS Pro. With this thesis, it is aimed to prevent the repetition of previously conducted microzonation studies, and settlement areas located near regions with seismic hazard where studies are lacking are also geographically identified. Since the microzonation database presented in this thesis will be further developed in future studies, the designation "Phase 1" has been added to the thesis title.