introduction extreme floods, hyperconcentrated and debris flows are common natural hazards in the basins which located in the northern slops of alborz mountain range (iranian north system). flood occurrence in golestan national park in 2001, 2002 and 2005( hosseinzadeh and jahadi toroghi 2012), yearly flash floods in masuleh catchment( rezaei, 2009), large flood in neka basin in 1999(poorahmad ...