Design And Analysis Of Debris Flow Monitoring System Based On Infrasound Method

As a natural disaster, debris flow is widely distributed and frequently occurs in mountain regions. Debris flow causes a huge threat to the safety of people's lives and property and to the ecological environment due to the fact that it occurs suddenly with strong destructiveness. The dynamic monitoring of debris flow is significant to disaster reduction. The existing debris flow monitoring methods have the disadvantages of slow response and low accuracy. Therefore, a monitoring system based on infrasound is designed.Infrasound waves can be detected in a long distance because of the features with low frequency, slow decay and strong penetration. In the process of debris flow development and occurrence, the breaking, extrusion and friction of rock and the collision and friction between debris flow and channel bed will generate infrasound waves. According to those characteristics, the infrasound monitoring sites are established to realize the long-distance detection of the debris flow, and the occurrence of the disaster is judged by the infrasound signals before the arrival of the debris flow to get valuable time for the disaster prevention.Based on the above principle, this paper designs the debris flow monitoring system based on infrasound, which includes infrasound sensors, data acquisition and transmission instruments and its supporting equipment, the server and the computer.The data acquisition and transmission instrument converts the infrasound signal collected by the sensor into digital signal and transfers to the remote server. The computer calls data from the server for signal processing and analysis, realize the monitoring of the affected areas. The PMCC algorithm is firstly applied to the debris flow localization in this system, and is verified to be feasible by simulation experiment.The simulation-experiments shows that there are special infrasound signals generated,and the frequency of the signals is mainly concentrated in 0.5?12.5Hz . According to the development law of debris flow, the infrasound signal near 12.5Hz is generated by the crack propagation of the sliding body; and the infrasound signal of 0.5?6Hz is the intermittent motion and friction of the slip surface. The infrasound characteristics obtained by the experiments can be used as an important reference for the infrasound monitoring of debris flow.