landslide zoning in jolesan basin with using of lnrf model

abstract a major part of iran includes mountain areas. one of the hazards which threaten these areas is the slope instability. each year the occurrence of this phenomenon causes a lot of damages to the slope lands which are exploited by man. one of the most lot hazardous of these instabilities is landslide. the goal was to investigate the causes of this process and the methods of its stabilization also. a case study was performed with the aim of zoning the landslide possibility in order to map the present slides in jolesan basin (one of the subbasin of chalkrood). this basin is located in mazanderan province at the west of tonekabon city. due to certain geological, geomorphologic and climatologic condition and also the way of exploiting the land. this area is considered one of the susceptible areas for landslide. destroying forests, roads, villages and farms are among damages cause by this process and can be seen frequently. for investigating and zoning landslide in this area, at first, the map of main factors in causing this process was designed. then, using the interpretation technique of satellite images etm+2002 and field work (gps). all present slides were identified and registered on the map. then, by integrating the factor map with landslide map through lnrf model. the numerical amount of each factor was calculated and the percentage for slide occurrence in different units of each map was estimated. at the end. the zoning map of landslide risk with overlaying different information levels was product. the result shows that lnrf model has excellent efficiency for studying the data and zoning landslide especially in humid areas. keywords: landslide, gis, lnrf model, jolesan basin, chalkrood.