Koyulhisar in Turkey is in danger of landslides, and to determine the risk of landslides in this area, many projects and studies are currently being conducted. Between 2007 and 2008, global navigation satellite system measurements were made, providing data on seasonal effects. The displacements, and also the forces behind these displacements, need to be studied. These forces may be determined using various methods. One method is the determination of strain parameters. With regard to the maximum and minimum principal strain parameters obtained (lambda(1)=56.3433 mu s, lambda(2)=-35.4642 mu s) from the city centre measurements, there is statistically significant stress accumulation in the Koyulhisar region. Furthermore, for the compression and contraction directions obtained in the city centre, compression was obtained in the north-south direction and contraction movement was obtained in the east-west direction. These movement directions show that the tectonic movements in the region have an effect on the landslide.