本研究於苗栗縣三義鄉火炎山一號坑進行礫石型土石流現地監測,藉由現地監測影像進行土石流運動特性分析,包括流動歷程、地貌變化、土石流前端部流速、陣流特性及彎道超高分析。彎道超高分析之流速與影像分析之流速,兩者誤差約為8.4%。彙整2016年至2022年間各土石流事件之降雨資料,有效累積雨量(含前期降雨)與土石流流動距離之間具有高度關聯性。本研究為探討火炎山因崖錐堆積或河道堰塞堆積受降雨逕流引發土石流之流動歷程及相關特性,於室內實驗室進行逕流引致堆積體破壞實驗。分析在不同流量及坡度條件下,顆粒之流動型態、破壞歷程、顆粒流運動特性及堆積體破壞後之各項參數與水流功率間之相關性。;The field monitoring of gravelly debris flows was conducted at the Houyenshan of San Yi county, Miaoli, Taiwan in this study. The monitoring data, including CCD and several cameras of time lapse photography, were used to analyze the flow history, geomorphological changes, debris flow velocities and super elevations at the bend. observed by compiling the rainfall data from 2016 to 2022. By compiling the debris-flow records and the rainfall data from 2016 to 2022, we found a high correlation between the effective cumulative rainfall and the debris-flow runout distance. The debris flows triggered by the fluidization processes of channel beds by overlying runoff was experimentally performed in this study, which is related to the debris flows occur at Houyenshan due to the mobilization of talus and upstream channel bed during rainfall. The flow patterns and failure processes of granular flows, and the correlations with stream power under different flow and slope conditions were explored.