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Design of Monitoring and Early Warning System for Geohazard in Three Gorges Reservoir Area Using Infrasound. The 2008 Infrasound Technology Workshop, Bermuda. Ning Qiu 1 , Zuo-Xun Zeng 1 , Yi-Chun Yang 2 1 China University of Geosciences, Wuhan 430074, China
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Design of Monitoring and Early Warning System for Geohazard in Three Gorges Reservoir Area Using Infrasound The 2008 Infrasound Technology Workshop, Bermuda Ning Qiu1, Zuo-Xun Zeng1, Yi-Chun Yang2 1China University of Geosciences, Wuhan 430074, China 2Institute of Acoustics, Chinese Academy of Sciences, Beijing 100080, China Email: QiuNing@cug.edu.cn
OUTLINE • Research background & significance • Methodology • Thinking for design • Problems that need to be resolved
Yangtze River Yichang Gezhouba Dam The Three Gorges Dam is a hydroelectric river dam that spans the Yangtze River in Sandouping town, Yichang city, Hubei province, China.
Aerial Image over the Xiling Gorge of Three Gorges above Yangtaz river Gezhouba Water Control Project Three Gorges Water Control Project Downtown of Yichang City, Hubei Province, PRC
Yichang City Gezhouba Dam
May 14, 2007 Landslide site located in Qingtaiping, Badong County, Hubei Province
Research Background • With the progress of the Three Gorges Dam Project, geohazard have become increasingly prominent. • The reservoir area prone to landslides, collapses, cracks, and earthquake disaster because the complex terrain and geological conditions.
Research Significance • It is of significance to monitor and foresee geohazard in the reservoir area. • Here we introduce our design of monitoring and early warning system for geohazard in Three Gorges reservoir area using Infrasound.
Methodology • Infrasound may be abnormal during geological disasters. • Such as debris and earthquake occurred. The formation and movement of debris flow in its basin will generate infrasound, and spread to the surrounding air medium. • Velocity of infrasound is much larger than that of debris flow, so we can monitor and forecast debris flow using infrasound.
Methodology • The sudden vertical displacement brought about by earthquake will generate acoustic-gravity wave which can be observed in distance to monitor earthquake, especially to monitor earthquake precursor. • So we try to monitor the geohazard for the Three Gorges reservoir area in China by design a infrasound array system.
Wuhan City Badong County Thinking for Design • The infrasound monitor system is comprised of two observation stations arranged in Badong County inside the reservoir area and in Wuhan City respectively.
Wuhan infrasound observatory station located inthe campus of China University of Geosciences
Amending Direction Sensor C2 d Quasi-Uniform Linear Array L3 L2 L1 C1 R1 R2 R3 d 3d Thinking for Design • Each station has respectively arranged a kind of augmentable linear array in the form of quasi-uniform linear array and additional amending direction sensors. 5d The linear array comprises eight sensors arranged in several different uniform intervals along a line. Amending direction sensor is situated at certain point in mid-perpendicular of linear array in order to reduce multiplicity in determine the direction of arrival.
PVC pipe Wind Cap Wind Resistance Equipment CDC Capacitive InfrasonicSensor Thinking for Design • The sensors used in the system are CDC-2B capacitances infrasonic receiver which can observe frequency ranging 0~20Hz. The, measurement resolution is 750mV/LPa.
Infrasound Sensor Array Internet Access PC 24 Bit A/D Card Thinking for Design • Infrasonic wave signal collected by sensor is transferred from observation stations to Data Processing Center in CUG, using telecommunication networks, and then we can process and analyze the infrasonic signals.
Problems that need to be resolved • Observations all-weather infrasound near the reservoir area can be achieved on monitoring geohazard in Yangtze River Three Gorges. There are still problems to be considered in the system: • (Ⅰ) in the conditions of using few sensors, this need more rational array layout mode; • (Ⅱ) sensors in field can lasting stability in some way; • (Ⅲ)the amount of data acquisition, real-time transmission, storage and backup need higher demands in hardware and software.
Thanks for your attention! Comments and Suggestions are most in need for us!! Email: QiuNing@cug.edu.cn Add. #388 Lumo Rd, Wuhan 430074, China