The classification of frozen hazards and protecting approach of permafrost region In Tibetan Plateau permafrost region

Studying of the permafrost region in Tibetan plateau,this article conclude the regularity of Plateau permafrost areas' distribution and change for years.The lower bound of permafrost decrease as the latitude increase.The permafrost decrease 80-100m averagly and the mean geotemperature increase 0.9-1℃ as the latitude increase 1℃ averagly.The regularity that the thickness of permafrost increase as the altitude increase is also obvious.The thickness increase 15-20m as the altitude increase 100m,the thickness can even be 128.1m in exposure.The article also divide the types of frozen hazards of years' permafrost,classify the common and typical hazard,also propose the method and recommendation of prevention.