本研究之主要目的，在於探討集水區之水文特性對土石流發生的影響，藉以建立土石流發生的臨界線，及理論推導與模擬實驗三方面進行研究。本研究蒐集台灣地區發生土石流之降雨資料，並針對引發各個水文因子做一統計分析，並利用Keefer之方法建立台灣本土引發土石流之降雨起動線。 在理論推導方面，本研究係延伸Woodhiser之推導公式，推求土壤分層時之水流狀況，比較地下水流與地表水流之不同之處。在模擬實驗方面，對土砂壩在不發生潰壩的條件下進行模擬，以了解土壩之穩定情形，及預防其發生崩壞而在下游產生土石流之臨界條件，並配合上述之理論推導探討土層內之水流狀況，以提供定量之潰壩參考依據。 The major purpose of this study is to explore the impact of the drainage’s hydrological parameters to the cause of the landslides, and then further investigate those parameters according to three categories: establishment of the critical rainfall condition, theory application, and experimental verification. Rainfall condition plays a crucial role of hillside fields’ stabilities in Taiwan’s environmental conditions. It is easier to examine, and less influenced by human activities, when compared to physiographic examinations. Therefore, the rainfall data is collected and the hydrologic statistics is analyzed. Keefer’s model is adopted to develop Taiwan’s local warning system. In theory application, this study extends Woodhiser’s model to find the water depths both above and inside the soil. The experimental verification is performed to check the validity of modified Dupuit seepage model.
