安徽地理（Geography of Anhui）.docVIP

安徽地理（Geography of Anhui） Periglacial geomorphology is a common surface morphology in severe cold regions. Periglaciation, frost thawing and freezing thawing, thermal creep flow, nivation wind effect can form periglacio-geomorphic. The landform can Shihai and stone river, polygon soil and stone ring, ice and ice, ice and ice nivation basin and hot melt topography. Ice cover refers to a series of freezing and thawing processes resulting from annual and diurnal variations in temperature and phase changes of water. Periglacial zone in a typical year fluctuation of temperature is 0 degrees centigrade by up to 150 days to 200 days, the surface material of frost heave, hot melt, freezing process of the specific creep and thawing nivation, forming many periglacial landform. The process of swelling of bedrock or soil caused by freezing. It will make the bedrock fissures along the rock burst, leading to disintegration phenomenon in rock - Shi blanket (Figure 1 over long stone - Shi (China Taiwan at the top of Mount Wutai, 2980 meters above sea level)). Shi often and tilt the extrusion of stones, because of frost heaving frost stones (Figure 3 frost stones (East Kunlun Mountains, elevation 5173 meters high at the top of Chinese)). It is also true that some of the piles in permafrost regions have been frozen and drawn up. Lenticular body of ice freezing water expansion, will make up the ground into the dome shaped hill (i.e. frost mound). The frost heave effect of underground soil contained in rock stress is the biggest, they were lifting upward and exposed surface, or the formation of frost heaving stones, or by a freezing center is pushed to the periphery, the most common form of stone polygon, periglacial stone, stone net of periglacial Geomorphology (Figure 4 giant stone (Urumqi Heyuan China Tianshan Mountains, 3600 meters above sea level)). Frost heave is the most representative landform in periglacial area The melting and thawing of frozen soil in the frozen soil can lead