关键词: 泥石流, 断层, 玄武岩喷出界面, 新疆乌恰县

Abstract: The geological condition is very complicated and the neotectonic movement including active faults is very active in Wuqia County, Xinjiang Autonomous Region, therefore debris flows are widely developed in is this area. It is particularly important to study the controlling factors of the debris flows, which are significant for early investigation and prevention in the areas with similar geological settings. We selected the basins of the Qiakemake River, Suyueke River and the Tuoyundaliya River where debris flows occurred most frequently in the county. Through remote sensing image and field investigation, the distribution law and characteristics were analyzed and the controlling factors of debris flows were further studied. The results indicated that the evolution of large-scale debris flows were mainly controlled by active faults and interfaces between sedimentary and basalt rocks. The broken rock mass in the fault zones and interfaces supplied materials for the debris flows. In addition, rainfall incised the broken rock mass to form valleys for transport of debris flows. The debris flows were mainly distributed within 3.5 km from faults or extrusive interfaces of basalt, and debris flows' density increased when getting closing to them. About 92.5% of the debris flows were distributed within a distance of 2 km. The density was the highest within a distance of 0.5 km and reached 0.4 per squire kilometer. In addition, large-scale debris flows were mainly distributed within a distance of 1.0 km from faults or extrusive interfaces of basalt, while small-scale debris flows were mainly distributed within 2 km.

Key words: debris flow, main controlling factors, fault, extrusive interface of basalt, Wuqia County of Xinjiang Autonomous Region