摘要
1989年7月26日贡嘎山东坡燕子沟内暴发一次特大型冰雪消融水和雨水混合型泥石流,流经30多公里后以9.41m/s流速,6 775.2 m^3/s流量冲入并堵塞了大渡河,直接经济损失达245万元。这场泥石流总径流量达1 716.4×10~4 m^3,总输沙量627.0×10~3 m^3,弯道爬高15.5—16.5 m。中国西部高山区今后还会出现这类现象和灾害,这是必须深入研究的重大课题。
A catastrophic debris flow of meitwater-rain type occurred in the Nanguan gully on the left bank of the middle reaches in ihe Yunzi Valley of the east slope in Mt. Gongga at 15-18 h, on 26 July, 1989. It destroyed a large highway bridge , blocked up the Dadu River and forced main flow line of the Dadu River towards the left bank. The Luding-Shimian Highway was washed out a length of 820 m, and the road had been closed for 9 months. The economy loss of 2.45 millions Yuan was estimated.
The Nanguan gully, located at 101 ° 54 ' 37.1 ' -101 ° 59 ' 11.3 ' E, 29° 41 ' 23.9 ' -29 ° 44 ' 39.5 ' N, has an area of 19.8 km2 large with a glacier area of 0.84 km2. The elevation range is 3 988 m, average longitudinal gradient of main gully bed is 215.7‰.
A length of flow way of the debris flow is above 30 km, it appears in gustiness lasting 3 hours. The fluid appears in viscousness. The maximum weight of the unit volume is from 2.0 to 2.4 t/m3. The velosity changes from 8.2 to 11.7 m/s. The peak flood changes from 2336.0 to 6775.2 m3/s. The total runoff into the Dadu River is about 1 716.4 × 104 m3, with the mud, sand and stone of 627.0 × 104 m3. The height creeping up of debris flow on the bend way is 15.5 to 16.5 m. A total of remaining sediments in the gully bed is 310.4 × 104 m3. The debris flow body filled all the gully bed on its flow way, made sedimentation of overflowing, decelerating and back flowing.
出处
《冰川冻土》
CSCD
北大核心
1992年第2期174-177,共4页
Journal of Glaciology and Geocryology
关键词
贡嘎山
燕子沟
泥石流
特大型
Mt. Gongga, Yanzi gully, debris flow of meltwater-rain type
