نقش فرآيندهاي ديناميك بيروني در مرفوژنز كوهستان تالش

The Role of External Dynamic Processes in Morphogenesis of Talesh Mountains

Variety is the inherent characteristic of our country. Geomorphologic studies leads us to use natural environment in its logical and optimized way, by finding reasons for physical environment variety, and this helps us by recognition of stable and unstable areas and identification of the type of the activities. Being mountainous, sharp declivity slopes, active faults, high average of rainfall, variation of temperature in high elevations, rich vegetation and existence of permanent rivers with high yearly discharge are considered as the physical characteristics of the investigated area. Talesh mountain erosion activity divides into two neighbor regions. First, subglacials over 2000m altitude including superiority of mechanical functions, overcoming of morphogenesis on pedogenesis , and Second, frost region which starts form the lowest border of sub glacial region and extends to the hillside by hegemony of physico-chemical activities and the overcoming of pedogenesis on morphogenesis. In this region, landslide is the most geomorphologic phenomena, which emanates from human mismanagement and highly influences mountains sensitive and unstable circumference and finally results economical and natural damages. Rivers erosion system is an active morphogenesis system and the most important factor of sediment transportation. Young rivers have a highly effective erosion activity at the bottom of V-shaped valleys-which erodes bedrock and shapes the shore by its transportation.