Hasan Tosun is professor in the Civil Engineering Department of the Faculty of Engineering and Architecture, Osmangazi University, Eskisehir, Turkey. He is the president of National Association of Dam Safety in Turkey. Dr. Tosun specializes in geotechnics for dam engineering, especially for embankment and rockfill dams and teaches Soil Mechanics and Engineering Geology. Up to 1997, he worked at the General Directorate of State Hydraulic Works, and supervised the geotechnical studies of large dams constructed in Turkey. He has over 190 technical papers published in national and international journals and conference proceedings, and is the author of four books on soil mechanics and geotechnics for dams. He is a member of the National Society of Soil Mechanics and Foundation Engineering.