【摘要】 <正> 1984年3月17日下午6时,在天山巩乃斯河谷内暴发了一次巨大的湿雪雪崩,造成堵塞河谷公路的严重危害(照片1)。笔者有幸目睹这次雪崩的全过程。本文通过对这次湿雪雪崩形成前兆和发生过程的观察,及对雪崩雪中若干特征的研究,分析其形成原因。 一、雪崩雪的若干特征 首先,湿雪雪崩主要特征可集中为一个“湿”字。正是由于“湿”,其雪崩雪成为大小不等的团块状构造(照片2)。经测量,雪崩雪堆中最大的团块直径为50—60cm,平均为15—30cm。大多数团块又具有成层构造,即团块外壳为淡黄褐色雪所构成,内更多还原

【Abstract】 On 17 March 1984 a heavy avalanche occurred in the Kunas valley, Tian-shan Mountains. Its essential features were investigated in comparison with the physics data measured in the snow observation field before its occurrence. Then the release causes of this avalanche were found from analysing these quantitative indices such as air temperature, temperature and temperature gradient within snow cover, water content and permeability of snow layers et al.. It is clear that the principal causes for wet-snow avalanches are the temperature, both air and snow, going up obviously, and then resulting in the change of temperature gradient direction and in distinct patterns of water content and permeability of snow layers, which are the measurable parameters for forecasting wet-snow avalanches. So we believe that there are the possibility of forecasting wet-snow avalanches and the feasibility of quatitatively analysing some parameters measured in snow layers. Some conditions for further forecasting wet-snow avalanches are created.更多还原