Reliability of landslide isopleth maps

  Following very heavy rainfall on 19/20 July 1983, 109 landslides occurred in the east of Findikli, Rize, north-east Turkey. The movements took place in completely weathered andesitic, dacitic and granitic rocks as well as slope debris. They extended over an area of approximately 25 km². The paper discusses the contour (isopleth) map prepared using data from the 1983 landslides and discusses its value for landslide hazard zoning. It is concluded that on the basis of 12 years of field evidence, a contour map derived from a precise inventory map can be a useful tool. Received: 28 November 1998 · Accepted: 15 May 1999