古沉积盆地的泥石流不稳定运动与震动信号的响应  

Debris flow unstable movement and response to seismic signals in paleosedimentary basins

作　　者：黄锋 吕立群 马超[1] 侯成宥 皋子琪 朱贵楠 HUANG Feng;L Liqun;MA Chao;HOU Chengyou;GAO Ziqi;ZHU Guinan(College of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Jiangxi Nuclear Industry Environmental Protection Center Co.,Company,Nanchang 330002,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]江西核工业环境保护中心有限公司,南昌330002

出　　处：《振动与冲击》2025年第6期223-230,共8页Journal of Vibration and Shock

基　　金：十四五重点研发(2023YFF1305201);第二次青藏高原综合科学考察(2019QZKK0902)。

摘　　要：黄河主流的下切导致同德盆地侵蚀基准面下降,促使同德盆地由古沉积区转化为侵蚀区,泥石流灾害频发,其形成运动过程的监测有利于保障河谷底部牧民的生命财产安全。运用带通滤波器、快速傅里叶变换、功率谱密度等地震动信号处理方法,揭示泥石流运动过程中的时频特征和能量特征;结合视频、泥位计、流速计、压力传感器等监测设备分析了泥石流动力学参数与震动信号之间的关系。结果表明:短时长时能量比法(short-term average/long-term average,STA/LTA)比值能够响应泥石流事件,龙头的STA/LTA比值远大于龙身,当泥石流呈现阵性流时,STA/LTA比值有激增现象,而且监测值比实际值要提前;功率谱密度能反映泥石流的不稳定运动过程,中、高频率的功率谱密度与低频率相比包含着更多的泥石流动力学信息;以单一能量阈值去区分泥石流和山洪并不可行,其能量阈值受到泥石流不稳定运动过程中沿岸崩滑物质加入的影响;地震动信号与泥石流泥位、流量、流速等单一运动参数的响应关系差,与质量流的响应关系最好。The incision of the Yellow River has led to a decrease in the erosion base level of the Tongde Basin,causing it to transit from a sedimentary to an erosional area,and increasing the frequency of debris flow disasters.Monitoring the formation and movement process of debris flows is beneficial for ensuring the safety of the lives and properties of pastoralists in the valley bottom.Techniques such as the band-pass filter(BP-filter),fast Fourier transform(FFT),and power spectral density(PSD)analysis were employed to uncover the time-frequency attributes and energy distribution patterns of debris flow movements.The relationship between the dynamic parameters of debris flows and vibration signals was analyzed based on combining the measured results of several monitoring devices such as video cameras,mud level meters,flow rate meters,and pressure sensors.The results indicate that the STA/LTA ratio can effectively respond to debris flow events,with significantly higher STA/LTA values at the debris flow head compared to those at the debris flow body.During the occurrence of episodic flows,the STA/LTA ratio exhibits a sharp increase,which is beneficial to achieve the monitoring values preceding actual events.Power spectral density can reflect the unstable movement process of debris flows,and the PSD in mid and high-frequency bands contains more dynamic information compared to that in low-frequency bands.Distinguishing between debris flows and flash floods based on a single energy threshold is not feasible,as the energy threshold is influenced by the addition of material from bank collapses during the unstable movement of debris flows.The relationship between seismic signals responses and single movement parameters such as mud level,flow rate,and velocity of debris flows is weak,while the relationship with mass flow is the most robust.

关 键 词：泥石流 同德盆地 河流下切 地震动信号 功率谱密度 

分 类 号：P512[天文地球—地质学]