• 论文 •

天山高山冰缘环境的融冻泥流作用

1. 1. 北京大学城市与环境学系;
2. 新疆大学地理系
• 收稿日期:1993-02-01 修回日期:1993-06-01 出版日期:1994-07-15 发布日期:1994-07-15
• 基金资助:
国家自然科学基金

OBSERVATION AND CONSIDERATION ON THE GELIFLUCTION IN THE ALPINE PERIGLACIAL ENVIRONMENT OF THE TIANSHAN MOUNTAINS

Liu Gengnian1, Xiong Heigang2

1. 1. Department of Geography,Peking University,Beijing 100871;
2. Department of Geography,Xinjiang University, Urumqi 830004
• Received:1993-02-01 Revised:1993-06-01 Online:1994-07-15 Published:1994-07-15

Abstract: Field survey and laboratory analysis have been conducted to research the gelifluction in the alpine periglacial environment of the Tianshan Mountains since 1990. The gelifluctions distribute at 2500─3600 meters above sea level. on the northward slope with slope angles of 10°─31°. The length of the gelifluction ranges 7─28. 4 meters. the width 6─30 meters and height 0. 7─4 meters.Most of the gelifluctions have lobate forms with a ratio of length to width less than 1. and a few of them have tongue forms with length to width ratio greater than 1. The slope gradient of the steep front of the gelifluctions ranges 27. 5°─85°.Forming and developing in active layer of the alpine permafrost zone. the gelifluction is mainly forced by gravity and freeze─thaw action. Based on the data from field pitting and laboratory analysis. it shows that grain─size and water content are stratified in the gelifluctions. The debris in gelifluction is oriented parallel to ground surface. The permafrost table under active layer forms a water─proof plane and offers a sliding plane for gelifluction.The moving rate of the gelifluction is measured at 2 800─3 600 meters above sea level where the mean annual temperature ranges-3℃--5. 3℃ and the mean annual percipitation ranges 430-850 mm. The surface moving rate of the gelifluction is 2. 1─18. 77cm/a. and the mean rate is 11. 14cm/a. The maximam front advancing rate of the gelifluction is 6. 76cm/a. and the mean rate is 1. 86cm/a. It shows that the surface moving rate is greater than that of the front advancing rate.The mean advancing rate of the middle part is 3.1cm/a, while the sides is 0. 83cm/a. This shows that the middle part moves more actively than th both sides.