The authors have developed a system of prediction of destructive cryogenic phenomena, i.e., of depth of thaw associated with development of a permafrost area. It is based on computer calculations using data on air temperatures, depth and nature of snow cover, type and thermal properties of the vegetation cover and the composition and properties of the materials of the active layer. To demonstrate the applicability they present a map of the northern part of Western Siberia showing ice content of the upper layers of the permafrost profile and isolines of thaw to a depth of 1 m in sands and loams which can be expected from different degrees of surface disruption.