Landslide monitoring through Kalman Filtering: A case study in Gürpinar

Many regions in Turkey are located on earthquake zones. The latest major earthquakes that hit eastern Marmara on August 17th and November 12th 1999 left tens of thousands of deaths. Another natural disaster that is a common in Turkey, mostly in Black Sea region and in some particular locations, is the landslides. In recent years several landslides happened after heavy rains and the resulting floods. This makes the landslide monitoring and mitigation techniques an important study subject for the related professional disciplines in Turkey. In the periphery of Istanbul, which is a metropolis with a population of more than 10 million, there are also some landslide regions. In this study, a landslide monitoring project in such a landslide area and the results obtained are discussed. The area is near Gürpinar village, located along the Marmara Sea cost to the northwest of Istanbul. The area that had been formerly an agricultural place was opened up for the settlements starting from the mid 80's. After than, several houses, mostly designed as weekend houses, were built. However, the effects of the landslides on the buildings were terrible. Many of the constructed buildings were damaged. The landslide monitoring project was carried out to identify the characteristics of the landslides and their potential risks. The geodetic measurement campaigns consist of two phases. In the first part of the monitoring, terrestrial geodetic observations were done in 6 epochs between 1990 and 1991. By the time, some network points were lost. In the second phase, the remaining network points were measured using the GPS technique in 4 epochs between 1996 and 1998. The results of the terrestrial works had been published before. In this study, only the campaigns with GPS observations are evaluated. The deformation analysis procedure applied is based on the Kalman Filtering technique. The results indicate the seriousness of the landslides. The displacements detected reach up to 5 meters. In the study, the approach for the deformation analysis and the overall displacements are presented.