investigating the effect of recent drought at gully erosion and landslides intensify in azarshahr catchment using neutral network

because of the presence of special properties in semi arid catchment, these areas are suitable for drought events. the responses of these areas to drought events are in the form of the disappearance of plant cover on surfaces slopes, intensive erosion or landslide occurrence on side of rivers’ course. azarshahr catchment (situated in 37ëš 36′ to 37ëš 49′ n and 44ëš 20′ to 45ëš 49′ e) as one catchment of sahand mountains (located at west slopes of sahand mountain) has experienced major changes at behaviors of geomorphological processes. the result of assessment of changes of surface and subsurface water, chemical characteristics of water, rivers’ sediment data show that these properties and characteristics influence drought events. to determine drought’s geomorphological effects resultant of these events all data were analyzed applying neutral networks and the final map was obtained by use of arc/view. the results show that the major effects of drought are present in southern, west and east of azarshahr catchment. these parts of catchment are very suitable for the occurrence of drought. gulling, landslides and rill erosion are outcomes of drought.