Landslide Mapping and Zonation at National, Regional and Local Scale — Recent Experiences from Republic of Macedonia

The paper presents anoverview of recent landslide mapping and zonation projects in Macedonia at different scales. On national level, the most recent study is a national scale susceptibility mapping performed within a geohazards study - part of the spatial plan of Macedonia. Due to limitations with regards to landslide characterization and a relatively poor landslide database, the rather simple arbitrary polynomial approach was applied. Lithology, terrain slope, rainfalls, earthquake acceleration and land use were considered causal factors for landslide development. Two susceptibility models, with different return periods for maximum expected earthquake acceleration according to Eurocode 8, were produced. The results are compared with previously performed studies and certain conclusions and recommendations for further activities were drawn. The second part of the paper is dedicated to regional and local scale mapping case studies, mostof which are done for the Polog region. Several techniques for landslide susceptibility mapping had been applied, such as LiDAR semi-automated susceptibility mapping, frequency ratio method, arbitrary polynomial method, DInSAR “hotspot” detection. Depending on data availability, different datasets were used for the specific methods. Based on results of the landslide susceptibility mapping, the landslide hazard and risk for a number of most critical locations was assessed at a local scale. These locations were considered for design of remedial measures. Namely, the preliminary remediation designs were made, consisting of at least two possible solutions per location. The solutions were then subjected to a cost-benefit analysis, upon which the final design was done for the most feasible one. Solutions are now beingimplemented. Some other regional and local scale assessments are presented only briefly in the paper