Vol15 No.7: 1397-1411
【Title】Avalanche activity and characteristics of its triggering factorsin the western Tianshan Mountains, China
【Author】HAO Jian-sheng1,2; HUANG Fa-rong1,3 ; LIU Yang1,5; Amobichukwu Chukwudi AMANAMBU1,2; LI Lan-hai1,3,4,5*
【Addresses】1 State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, No. 818 South Beijing Road, Urumqi 830011, China; 2 University of Chinese Academy of Sciences, Beijing 100049, China; 3 Yili Station for Watershed Ecosystem Research, Chinese Academy of Sciences, No. 818 South Beijing Road, Urumqi 830011, China; 4 Xinjiang Regional Center of Resources and Environmental Science Instrument, Chinese Academy of Sciences, Urumqi 830011, China; 5 CAS Research Center for Ecology and Environment in Central Asia, No. 818 South Beijing Road, Urumqi, Xinjiang 830011, China.
【Corresponding author】LI Lan-hai
【Citation】Hao JS, Huang FR, Liu Y, et al. (2018) Avalanche activity and characteristics of its triggering factors in the western Tianshan Mountains, China. Journal of Mountain Science 15(7). https://doi.org/10.1007/s11629-018-4941-2
【Abstract】Snow avalanche is a serious threat to the safety of roads in alpine mountains. In the western Tianshan Mountains, large scale avalanches occur every year and affect road safety. There is an urgent need to identify the characteristics of triggering factors for avalanche activity in this region to improve road safety and the management of natural hazards. Based on the observation of avalanche activity along the national road G218 in the western Tianshan Mountains, avalanche event data in combination with meteorological, snowpack and earthquake data were collected and analyzed. The snow climate of the mountain range was examined using a recently developed snow climate classification scheme, and triggering conditions of snow avalanche in different snow climate regions were compared. The results show that snowfall is the most common triggering factor for a natural avalanche and there is high probability of avalanche release with snowfall exceeding 20.4 mm during a snowfall period. Consecutive rise in temperature within three days and daily mean temperature reaching 0.5°C in the following day imply a high probability oftemperature-rise-triggered avalanche release. Earthquakes have a significant impact on the formation oflarge size avalanchesin the area. For the period 2011-2017, five cases were identified as a consequence of earthquake with magnitudes of 3.3≤ML≤5.1 and source-to-site distances of 19~139 km. The Tianshan Mountains are characterized by a continental snow climate with lower snow density, lower snow shear strength and high proportion depth hoar, which explains that both the snowfall and temperature for triggering avalanche release in the continental snow climate of the Tianshan Mountains are lower than that in maritime snow climate and transitional snow climate regions. The findings help forecast avalanche release for mitigating avalanche disaster and assessing the risk of avalanche disaster.
【Keywords】Snow avalanche; Snow properties; Snow climate; Triggering conditions; Risk management