Comparison of periglacial processes in permafrost and seasonal frost environments

-永久冻土的存在是否增强了地貌过程？-永久冻土融化引起的地貌过程是什么？为了回答这些问题，在日本、中欧、斯瓦尔巴群岛和西藏的山区进行了岩石风化和土壤运动的野外监测。监测点由相似的沉积地质组成，但地热状况不同。监测点还进行了地面内部结构、水文和降雪条件的调查。综合这些数据，评估了多年冻土的存在和长期演变对地貌变化的影响，得出了以下结论：1.对岩壁和碎石边坡上的温度、湿度和地面运动(冻胀、冻胀和固结)的监测表明，与地面温度和水分条件有关的地面运动的季节性变化。2.对岩体不连续面和土壤结构的研究表明，岩石崩落对岩体强度的影响也取决于节理间距，而碰撞对岩体强度的影响则取决于细土的近地表厚度。3.用电法探测内部结构，地震和热学方法以及直接钻探显示了区域范围内永久冻土的分布和深度。在欧洲阿尔卑斯山和藏东山区，处于多年冻土边缘条件的地区，多年冻土的快速退化和相应的加深活动层最近发生了进展，导致了冰缘过程的加速或减速。4.综合现有的和新的冰缘过程数据，得到了作为温度、湿度、地面物质和地形函数的地面运动的数值模型。

-Does the presence of permafrost reinforce geomorphic processes?-What does permafrost melting induce geomorphic processes?In an attempt to answer these questions, field monitoring on rock weathering and soil movements were undertaken on mountains in Japan, central Europe, Svalbard and Tibet. The monitoring sites consist of similar sedimentary geology while differ in ground thermal regimes. The monitoring sites underwent also investigations on ground internal structure, hydrology and snow conditions. These data were integrated to evaluate the effects of the presence and long-term evolution of permafrost on geomorphic changes, which led to the following conclusions.1.Monitoring of temperatures, moistures and ground movements (frost wedging, frost heave and solifluction) on rockwalls and debris slopes indicates seasonal variations in ground movements associated with ground thermal and moisture conditions.2.Investigations of rock mass discontinuity and soil structure indicate that the rate of rock fall on the rock mass strength depends also on joint spacing while that of solifluction on the near-surface thickness of fine soil.3.Sounding of internal structure by electric, seismic and thermal methods as well as direct drilling show the distribution and depth of permafrost at regional scales. In the European Alps and eastern Tibetan mountains, which are located at the marginal permafrost conditions, rapid degradation of permafrost and corresponding deepening active layer have recently progressed, causing either acceleration or deceleration of periglacial processes.4.Integrating the extant and new data on periglacial processes leads to numerical models of ground movements as a function of the temperature, moisture, ground materials and topography.