Induced Mechanism For Debris Flow In Huyu Gully Basin, Xishan Region In Taiyuan

The debris flow, a geologic hazard, is a high concentration mixture rheid of solid-liquid gas phase, which has a sudden outbreak and terrible destruction in a wide range. By the end of 2006, there were 544 hazards of debris flow, accounting for 4.9%of the total number of geologic hazards; 352 deaths due to debris flow, making up 31.4%of the total number of deaths because of the geologic hazard; 472 million of direct economic loss stems from debris flow disasters, taking up 17.4%of the total number of direct economic loss in geologic hazard. To the whole country, the occurrence rate of debris flow was 6.48%in 2010, resulting to 63.7%of the total death and missing caused by geological disasters. In conclusion, the debris flow is a severe threat to human life and property.On August 4,1996, large debris flow broke out in Huyu gully basin, Xishan region in Taiyuan, resulting in an impact area of 8km2, causing 36 deaths, nearly 240 million of direct economic loss and 62 hours traffic disruption in main streets, so, it has a terrible effect to the whole society. After the disaster, the government organized experts and scholars to investigate the disaster in detail, and then propose some practical plan for preventing the disaster. However, to the whole 50.17km Huyu gully basin, the mining activities are highly developed and the geological environment is complex. So, it is worth of researching the characteristics and induced mechanism systematically of debris flow in Huyu gully basin, and then makes reasonable control measures.In this paper, the source distribution and storage were investigated in the Huyu gully basin baseing on the large amount of data, showing the source is rich, and debris flow is easily to be formed during the heavy rainfall. On the basis of calculating kinetic parameters as debris flow weight degrees, velocity, flow and outbreak impact in Huyu gully basin, the outbreaks frequency, scale, scope and level of risk damage of debris flow have been predicted. In conclusion, Huyu gully basin debris flow is a large thin debris flow type with strong flow, strong impact and high-risk. And it has a large impact area due to its severe destruction and moderate eruption rate.In this paper, the valley longitudinal profile morphological index N value has been predicted, showing Huyu gully basin is in (N>1) equalization adjustment time (the prime of life). From the bulk source volume, the solid content has reached 2 times than the critical capacity of the outbreak content. According to the chart analysis and previous experience, it is possible to outbreak debris flow before and after 2012,2020 and 2028 in the condition of the same amount of accumulation.Finally, based on the above research results and combining with basic situation of Huyu gully basin, the prevention measures have been proposed, providing the basis data and theoretical basis for preventing debris flow in Huyu gully basin.