Landslide hazard mapping of Oghan watershed basin in Golestan province using fuzzy model

The first step in natural resources management and development plans is mapping and identification of areas with landslide hazard potential. The purpose of this research is evaluation of landslide hazard of Oghan watershed basin in Golestan province using Fuzzy-based model. For this, first Landslide dispersion maps of the basin were prepared using aerial photos, geological maps and field studies, then map of each of the effective factors in landslide occurrence such as (elevation, slope and aspect, lithology, rain classes, land use, distance from fault, distance from streams and roads) as information layers in Geographical Information System (GIS) were prepared and have been used in fuzzy-based model. After standardization of each mentioned layers using fuzzy membership function and combination based on fuzzy operators (sum, and, or, product and gamma), map of landslide hazard zoning was prepared in four danger classes that are low, medium, high and very high. Results, in comparison with other operators, showed that zoning map of the Gamma fuzzy operator (0.5) with quality sum(Qs) of 1.17 has the highest accuracy and Sum, And and OR operators with Qs less than 0.039 have the lowest accuracy in landslide hazard zoning of Oghan watershed. Key words: Mapping, Landslide, Fuzzy model, Oghan watershed, Golestan Province. Extended abstract Introduction Landslide is one of the most destructive natural events in steep areas. Due to its geographical position, climatic and geomorphological conditions, population increase, pressure on natural resources and land use change, Iran is exposed to natural hazards like landslide. Therefore, identification and preparation of natural.