以實驗分析地聲能量與土石流流量關係

Abstract

本研究旨在分析地聲能量與土石流流量之間的關係，透過室內實驗來模擬現場土石流事件，並在不同坡度條件與水流流量下，進行了五次實驗。地聲檢知器用於紀錄土石流流動過程中產生之振動訊號，這些訊號利用短時距傅立葉轉換(STFT)分析後，最後透過積分轉換成能量。同時，利用攝影機記錄土石流之表面與側面之顆粒速度、流深，流量等物理參數。在分析數據階段，利用卷積(Convolution)將地聲能量與影像資料進行時間對齊，隨後，透過無因次分析來將地聲能量與土石流之物理參數進行分析。分析結果顯示，無因次分析後的能量與福祿數有顯著相關。並將現場土石流事件做為參考點與野外實驗得到之數據做比較得出流量與能量之間的斜率關係可能會因濃度的不同而有所變化。

This study aims to explore the relationship between underground sound energy and debris flow rate through indoor experiments simulating the debris flow in the field. Five experiments were conducted under different slope conditions and water flow rates. Geophones recorded the vibrations produced by the debris flow. These signals were analyzed using Short-Time Fourier Transform (STFT) and converted into energy through integration. With cameras recording, the physical parameters included surface and side particle velocity, flow depth, and flow rate were extracted. In the data analysis stage, convolution was used to time-align the geophone energy with the video’s data. Subsequently, dimensionless analysis was carried out to correlate the geophone energy with the physical parameters of the debris flow. The results indicate a significant correlation between geophone energy and the Froude number. By using actual debris flow events as reference points and comparing them with data obtained from field experiments, it was determined that the slope relationship between flow rate and energy might vary depending on the concentration.