Geophysical applications in urban and regional planning and effects of seismicity on planning

City and Regional Planning can be defined as a whole of social, economic and physical studies aimed at creating sustainable and risk-free living spaces based on public interest. The fact that many professional groups from different disciplines come together and contribute to the Decently carried out planning process is an important factor in the design of the future image of the city or region. The studies carried out only in order to meet the needs of the day, without balancing with the natural environment, and without examining the geological, geophysical and geotechnical characteristics of the area, have revealed the current problems of today's cities. In the first stage of this thesis study, the place of geophysical applications in City and Regional Planning and their areas of use in Turkey were examined. In the second stage, the effect of seismicity, which is one of the fields of geophysical science, on planning was evaluated and earthquake hazard analysis was performed in Adıyaman province. Within the scope of this study, the method of Gumbel extreme values, one of the models applied in probabilistic seismic hazard analysis, was used. With the magnitudes of the earthquakes recorded between 1900 and 2023 for the region covering an area with a radius of 200 km from the city center of Adıyaman, the recurrence times and occurrence probabilities of earthquakes that may occur in different time periods (medium and long term) have been estimated. Dec. As a result, the current earthquake activity within the borders of Adıyaman province was analyzed with statistical evaluations and an attempt was made to identify the earthquake risk by examining it in terms of earthquake hazard. According to the Gumbel extreme value distribution, the recurrence periods of earthquakes with magnitudes Mw = 6.0, Mw = 6.5, and Mw = 7.0 are 14 years, 36.6 years and 95 years. The occurrence probabilities within 5, 10, 30 and 50 years were determined as 30%, 51%, 88%, 97% for Mw=6.0, 13%, 24%, 56%, 74% for Mw=6.5 and 5%, 10%, 27%, 41% for Mw=7.0, respectively.