Analysis of cause of formation and form characteristic of the “8.12” flash-flood debris flow at Huangzhu town in Gansu province

The Huangzhu town be located in the geological disasters in high frequency area-in the hill country of Longnan North.On 12 August in 2010,around the town Huangzhu,happened heavy rain with since the century,form flash-flood disasters,and induced debris flow,landslides,collapse of mine water bursting,road bank such as secondary disasters,to the local people and factory operation caused significant deposits of disasters and loss.In this paper,the characteristics of the flash-flood debris flow hazards and cause analysis,reach a decision:the heavy rain is immediate cause of the formation of the disaster,the humans unreasonable activity is increasing the disaster damage degree,and at the same time the local topography and landforms,rocks and conditions are also of the formation of the disaster favorable conditions.