ORIGINAL ARTICLE Evaluation of rock slope stability for a touristic coastal area near Kusadasi, Aydin (Turkey) Yavuz Kaya 1 • Tamer Topal 1 Received: 7 May 2014 / Accepted: 27 April 2015 Ó Springer-Verlag Berlin Heidelberg 2015 Abstract The study area, which will be open to tourism in Kusadasi (Aydin), has steep and high cliffs on the Aegean coast in Turkey. Flysch is the main lithological unit and consists of alternating sandstone–claystone–marl sequences. Some sliding and rockfall problems have oc- curred in the area in the past, so potential geological haz- ards need to be investigated to ensure the safety of tourists. The aim of this study is to mitigate geological hazards by recommending engineering solutions, which will ensure the continuation of the nature-friendly appearance of the slopes. To accomplish these tasks, a geological survey was performed. It involved gathering information on rock dis- continuities by means of scan-line surveys and collection of rock samples. Furthermore, in situ and laboratory tests were also carried out. The data collected from the field and laboratory test results were used to perform slope stability and rockfall (2-D and 3-D) analyses for different slope conditions along 43 profiles. Based on the analyses, rock- fall was found to be the main slope instability problem in the study area. Under the light of these studies, rock re- moval, drainage, greening (vegetation), filling of caverns, protective wall building and erosion prevention are offered as remedial measures. Keywords Flysch Á Rockfall Á Slope Stability Á Kusadasi Á Turkey Introduction Kusadasi is a touristic coastal town in the Aydin province of Turkey. A coastal area located about 5 km south of Kusadasi is now under rehabilitation and will be open for tourism in the next few years. However, this area is seri- ously affected by landslide and rockfall problems where steep and high cliffs (Fig. 1) near the coast pose a great danger to future tourists. Some sliding and rockfall prob- lems have already been observed in the past. These geo- logical hazards need to be investigated and remedial measures which keep the nature-friendly appearance of the slopes should be taken in preparing the area for touristic use. The study area covers 0.24 km 2 and has a flat mor- phology in general but it has steep cliffs on the coast especially at the western part of the region (Fig. 1). Access to the study area is from the Kusadasi-So ¨ke highway in all seasons. A number of studies related to sliding and rockfall problems exist in the literature (Pfeiffer and Bowen 1989; Turner and Schuster 1996; Guzzetti et al. 2002; Crosta and Agliardi 2003; Schweigl et al. 2003; Wyllie and Mah 2004; Dorren et al. 2004, 2005; Frattini et al. 2008; Choi et al. 2009; Paronuzzi 2009; Tunusluoglu and Zorlu 2009; Binal and Ercanoglu 2010; Volkwein et al. 2011; Ramı ´rez-Her- rera et al. 2012; Tanarro and Munoz 2012; Alejano et al. 2013; Fityus et al. 2013; Singh et al. 2013; Shi et al. 2013; Youssef et al. 2015). The aim of this study is to mitigate geological hazards by suggesting remedial measures which maintain the na- ture-friendly appearances of the slopes. Slope stability and rockfall (2-D and 3-D) analyses were carried out to design mitigation measures. In this study, methodologies adopted by Kentli and Topal (2004), O ¨ ztekin et al. (2006), and Topal et al. (2007, 2012) are considered. They mainly & Tamer Topal topal@metu.edu.tr 1 Department of Geological Engineering, Middle East Technical University, 06800 Ankara, Turkey 123 Environ Earth Sci DOI 10.1007/s12665-015-4473-9