Extended Abstract
Introduction
   Ancient cities and cultural heritage are the lasting works of past generations that make us familiar with our identity, so our duty in the present era is to preserve these precious treasures and take care of them. Buildings undergo frequent changes and damages over time. Therefore, in this article, we decided to monitor the changes and destruction of one of the important ancient provinces of Turkey, named Ghazi Ayantep. The method that was used in this research is the radar interferometric method which was obtained by using the radar data of Sentinel 1 satellite and processing them in Snap software. In the first stage, four images were collected in a period of 24 days before and after the earthquake and about 9 aftershocks at very close distances from the Sentinel 1 satellite. Points to Anatolian faults have subsided more than half a meter. The information obtained from the Geological Organization of Turkey and the images obtained from the map of the affected areas in this province provided by the United Nations Satellite Center were used as a basis for comparison. In the second stage, by overlapping the obtained map and the topographic map of the region, which was collected from the information of the Geological Organization of Turkey, we found in the GIS software that, on average, the highest amount of changes is related to the high areas of this province. The topography of ancient areas and the slope of the areas where ancient cities or valuable monuments are located will have a direct effect on the displacement and subsidence of these areas. And in the third stage, by examining the results and comparing the map obtained from the displacement with the fault map of the studied area, it can be concluded that after the earthquake in this area, the greatest amount of destruction of historical cities is related to the areas that are close to the sea and lakes. have in the end, the investigations showed that the humidity and the distance of the areas from the sea had a direct effect on the amount of destruction and damage caused to this province.
   1- Data and research method
     1-1-Study area
   The study area in this project is Gazi Ayantep province of Türkiye. Gaziantep province is located in the southeast of Turkey at the geographical position of 37 degrees and 4 minutes north and 37 degrees and 23 minutes east and 250 kilometers from the Anatolian fault. On February 6, 2023 (Bahman 17, 1401), a powerful earthquake measuring 7.8 on the Richter scale shook central and southern Turkey and northern and western Syria for 75 seconds. This earthquake occurred 30 km away from Ghazi Ayantep city and at a depth of 17.9 km and left irreparable damages. Also, 9 hours later, another earthquake with a magnitude of 7.5 on the Richter scale occurred 105 km from the epicenter of the first earthquake and 10 km deep, which was the largest earthquake in the Anatolian region in the last 2000 years.
1-2-Research method
    In order to receiving data, 4 images were collected at a time interval of 8 days from each other. The first image was taken on February 4, 2023, two days before the first earthquake, the second image was taken on February 12, the third image was on February 20, and the final image was taken on February 28, 2023. The information obtained from the Geological Organization of Turkey and the images obtained from the map of the affected areas in this province provided by the United Nations Satellite Center were used as a basis for comparison. It should be noted that the purpose of this research is to investigate the changes and destruction of the affected areas. It is historical as well as the prediction of high-risk points in valuable ancient areas and places, so there is no need for very accurate figures of land subsidence in these areas to match the obtained map with land use maps and other related information maps. However, due to the elimination of many errors and accurate processing of images, as well as the basis for comparing the results, the obtained numbers can be cited in most cases.
     The interferogram is the result of displaying the phase difference caused by the change of the distance between the ground phenomenon and the sensor in two consecutive passes. This step is simply done to obtain the phase difference between two images in consecutive passes. (Wright & et al, 1999 p. 2) In all radar images, the interference of waves as well as the topographical factor of the earth's surface creates an adverse effect on the images, which is known as speckle noise. The process of reducing image noise causes changes that require a filter to be applied to minimize the degradation of the image, which Goldstein filter is used here. The last step is to convert the obtained phase resulting from the application of filters to the amount of displacement. In other words, it is the quantification of the obtained phases. And after that, it is necessary that the obtained image of the ground be used as a reference and a small and accurate amount of displacement is extracted. In this paper, SRTM digital model is used for ground referencing of images.                           
    The Geological Organization of Turkey and the United Nations Satellite Center provided pictures and maps of the most damaged areas in the research conducted after the earthquake in this province. Finally, by examining and comparing the maps and information extracted from these institutions as a basis for comparison, the correctness of the results was determined, and after the observations, the areas were ranked from the most to the least in terms of damage, as well as the areas exposed to earthquakes, respectively. They were classified from the most dangerous to the least dangerous.
  2-Discussion and conclusion
     The most important achievement of this project is to obtain the amount of destruction of ancient cities and to study high-risk areas exposed to earthquakes. By overlapping the topographic map of the region with the obtained displacement, it was found that the highest displacement is related to the western cities of the province, and the closer we get to the eastern cities, the destruction rate decreases. The city of Islahiyeh with an average height of 490 meters and displacement of 0.55 to 0.57 meters witnessed the highest amount of displacement. After that, the city of Noordai with an average height of 516 meters has the highest displacement of about 0.53 to 0.55 meters, and then the cities of Shahin Bey, Shahid Kamal, Yavuzli, Ogozli, Araban, Nizip and Karmamish respectively witness the highest displacement. They were the least amount of displacement. Also, by examining the land use map and examining the texture of the urban area and matching the vegetation map of the province with the extracted displacement map, it was found that the areas with agricultural texture and high humidity as well as the areas close to the rivers and water areas had the highest displacement. According to the fact that the area of ​​Issahiyeh with its agricultural context and agricultural lands and numerous villages had the highest level of destruction compared to the highland cities, it was found that the humidity of the study area and its distance from the sea and water areas have a direct effect on the amount of displacement and subsidence of the land. and then the height of the studied area will be the next influencing factor directly. Investigations showed that as we move from Issahiye agricultural area to Nordai area, the height of the area will increase, and after this area, the height of the areas will decrease as we continue towards the eastern areas of the province. Interferometry using radar data is an efficient method to investigate changes, especially in the study of ancient artifacts, so the use of this method can greatly reduce possible future risks. According to the results and observations obtained from the land use map of this province, in order to prevent severe damage to ancient monuments and loss of life, it is necessary to take the most precautions in areas with high humidity and areas that have the least distance from seas and rivers and the most Renovation should be done for ancient monuments located in high areas. Considering the amount of changes in Ghazi Ayantep province, the obtained numbers are worth considering and indicate the dangers that still threaten this city. However, if it is possible to detect faults and dangerous areas in the coming years using this method and make the necessary preparations according to the mentioned recommendations, many lives can be saved when such natural disasters occur and many losses can be avoided. Sang, which threatens the ancient monuments, was prevented. Also, by increasing the accuracy of these radar images and having more advanced equipment, the details of the destruction of historical buildings can be obtained uniquely and with more accuracy and detail, which will greatly help the restoration and restoration of these buildings in the future.