Research On Landslide Monitoring And Early Warning In Ya’an Area

Because of the complex geological structure and great topographic relief, China has the basic geological conditions of the landslides. Affected by increase extreme weather events, frequent earthquakes and more strongly engineering, the landslide will be more and frequently in the furfure.Geological hazards monitoring and early warning has an important role in avoiding and reducing the loss of geological disasters. Due to the lack of disaster pregnant environment investigating and analyzing, and the lack of integration between investigation, monitoring and warning, the accuracy of geological hazards early warning is low.On the basis of investigation, this paper studies the development and distribution rules of geological hazards in Ya’an area. As of 2014, Ya’an area has more than 2600 geological hazards, the largest number is landslide, followed by the collapse and debris flow. All kinds of disasters are distributed along the valley, which is consistent with the distribution of tectonic belts and seismic belts. Rainfall is the most important factor to induce geological hazard. "5.12" Wenchuan earthquake and "4.20" Lushan earthquake induced or exacerbated the plenty of geological hazards, and geological hazards caused by human engineering activities showed a rising trend.To study the controlling factors and deformation mechanism of the Xiakou landslide, Duoying landslide and Hongyanzi landslide, we conducted continuous multi-parameter monitoring using GPS, fixed borehole tilt-meter, osmometer, and crack-meter. By monitoring data, we studied the relationship between controlling factor and deformation characteristics. Base on the inverstigation and monitoring data, we set up models by GeoStudio software, and the influence of rainfall, earthquake and reservoir water level descending on the stability of the landslide is analyzed.Based on the statistics for Ya’an’s geological hazards in recent years, we determined the effective rainfall is 3 day cumulative precipitation. According to the simulation and monitoring results, we establish early-warning criterion for geological hazards. Combined with geological hazards susceptibility assessment, a regional warning model of geo-hazard is established.Base on the early warning model, we carried out the geological hazards early warning in Ya’an area, and achieved good results.This paper has carried out 3 aspects of the innovative research:①the distribution law of geological hazards in Ya’an was studied, the quantitative relationship between the induced factors and the safety factor is established by the simulation.②the monitoring and simulation results of typical landslide are applied to the construction of early warning criterion system. ③ an operable geological hazard monitoring and early warning work flow is established.