Monitoring of deformations in Yalova Hacimehmet Plain with GNSS technique

The Hacımehmet plain in the Yalova Center was among the regions most affected by the earthquake in the province in the August 17, 1999 earthquake. In the engineering studies carried out in the region in the years following the earthquake, it was observed that deformations had reached the median for the region and that there were visible landslides in the region. Due to the fact that the region was established on alluvial ground, the density of constructions along the Safran Creek and the high number of devastating damages and loss of life in the earthquake disaster, attention was drawn to this region. The aim of this study is to present numerical findings on the deformations in this area in line with the measurements and analyzes made. In the study, it was aimed to determine the deformation of the Hacımehmet plain with high precision by geodetic measurements and 23 new ground points were established in this area. 3 campaign GNSS measurements were carried out on the established network between 2022-2024. The measurements of the Turkish National Fixed GNSS Stations Network Active (TUSAGA-Active) point located around the study area were also included in the study and the GNSS measurements were evaluated with the GAMIT/GLOBK software suite and it was aimed to obtain the current velocity field of the region. Within the scope of this study, it is observed that the region moves approximately 17-21 mm/year in the W-SW direction. It was determined that local deformations occurred in the region in different directions and speeds.